JP6179015B2 - Granules, method for producing the same, and property modifying material - Google Patents

Description

  The present invention relates to a granular material made of a silica particle material and a method for producing the same.

  Conventionally, a thermosetting resin composition containing a silica particle material in a thermosetting resin is known. By including the silica particle material in the thermosetting resin, the heat resistance can be improved with respect to the resin composition, or the physical strength can be improved.

  Here, colloidal silica which is a kind of silica particle material is produced by a method of producing water glass as a raw material, a method of producing metal silicon powder as a raw material, a gas phase synthesis method, or the like. A method for producing water glass as a raw material produces fine particles by precipitating the water glass by neutralizing and ion-exchanging the water glass (see, for example, Patent Document 1).

  The particle size of such silica particle material is very small, for example, about several nanometers to several hundred nanometers in colloidal silica. Such silica particle material is mixed in a thermosetting resin and used for a transparent material. It has been applied to use in filling very small gaps.

  The mixing of the silica particle material and the thermosetting resin is usually performed on the thermosetting resin before curing (hereinafter sometimes referred to as “thermosetting resin precursor”). The silica particle material may be subjected to surface treatment for the purpose of improving the affinity with the thermosetting resin.

  The silica particle material having a small particle diameter described above has a very large specific surface area. For this reason, silica particles with a small particle diameter have the characteristic of being easily aggregated. Once agglomerated silica particles are difficult to redisperse. For this reason, the silica particle with a small particle size has a problem inferior in handleability.

  Therefore, when mixing the silica particle material having a small particle size and the thermosetting resin, the silica particle material is mixed with the thermosetting resin precursor in a dispersion state dispersed in some dispersion medium, and then the dispersion medium is removed. Things have been done.

JP 2006-45039 A

  As described above, since the silica particle material having a small particle size is inferior in handleability, there is a demand for improving the handleability.

This invention is made | formed in view of the said situation, and makes it the subject which should be solved to provide the granular material which consists of silica particle material, was excellent in the handleability, its manufacturing method , and a characteristic modifier .

(1) The granular material of the present invention that solves the above problems is a transmittance at a wavelength of 365 nm of a dispersion liquid mixed at a concentration of 10% based on the mass of a dispersion medium composed of methyl ethyl ketone and dispersed for 10 seconds by a shaker ( The optical path length 1 cm) is 10% or less,
The transmittance at a wavelength of 365 nm (optical path length 1 cm) of the dispersion liquid mixed at a concentration of 10% based on the mass of the dispersion medium composed of methyl ethyl ketone and dispersed by a wet jet mill at a pressure of 180 MPa is more than 10%.
The primary particles are made of a silica particle material having a volume average particle diameter of 1 nm to 100 nm.
Usually, it exists in a state of secondary particles and is excellent in handling, but has a high dispersibility that can be easily dispersed to primary particles by applying a mechanical load. Here, a “vortex mixer” uses a vortex mixer (model number: MS1S1, manufactured by IKA). The dispersion is shaken with a vortex mixer while being held in an appropriate test tube. At that time, the degree of shaking changes depending on the force of pressing the test tube against the vortex mixer. Since the granular material of the present invention has a small improvement in dispersibility depending on the mechanical load that can be realized by a vortex mixer, the transmittance at a wavelength of 365 nm does not exceed 10% even if the pressing condition changes.
(2) At least a part is a secondary particle that is dispersible to primary particles by a mechanical load and exhibits fluidity, and the primary particles are made of a silica particle material having a volume average particle diameter of 1 nm to 100 nm.

The granular material of the present invention described in (1) above can be combined with one or more of the constituent elements (4) and (7) disclosed below. The granular material of the present invention described in the above (2) can be combined with one or more of the components (3), (4), (6), and (7) disclosed below. When combining (4), one or more of (5) and (8) can be combined.
(3) Instead of determining whether at least a portion described above can be dispersed to primary particles by mechanical load, with respect to 100 mL of a dispersion in which 10% by mass is dispersed in a dispersion medium composed of MEK based on the total mass. After irradiating with ultrasonic waves for 5 minutes, 95% or more passes when suction filtration is performed with 5 kinds C filter paper of JISP3801 standard.

(4) The surface is treated with a silane coupling agent and has a silanol group on the surface.
(5) In addition to the silane coupling agent, it is treated with organosilazane.
(6) The mechanical load is any one of the following (i) to (iv). (i) Crushing operation. (ii) Mixing operation with powder and granule. (iii) Ultrasonic irradiation in liquid. (iv) Stirring operation in liquid.

(7) The silica particle material includes a functional group represented by the formula (1): -OSiX ¹ X ² X ³ and a functional group represented by the formula (2): -OSiY ¹ Y ² Y ³ and both functionalities. It consists of silica particles with groups bonded to the surface. (In the above formulas (1) and (2); X ¹ is a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group; X ² , X ³ are each independently selected from -OSiR3 and ^{-OSiY 4 Y 5 Y 6; Y} 1 is an ^{R; Y} 2, Y ³ are each selected from R and -OSiY ⁴ Y ⁵ Y ⁶ independently. Y ⁴ is R; Y ⁵ and Y ⁶ are each independently selected from R and —OSiR 3, and R is independently selected from an alkyl group having 1 to 3 carbon atoms, wherein X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ are each represented by —O— with any one of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ . May be combined.)

(8) The silane coupling agent has three alkoxy groups and a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group,
The molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10.

(9) The manufacturing method of the granular material of the present invention that solves the above problems is a manufacturing method that can manufacture the above-mentioned granular material,
A surface treatment step of surface-treating the raw silica particles with a silane coupling agent and organosilazane in a liquid medium containing water;
After the surface treatment step, the raw material silica particle material is precipitated with a mineral acid, and the precipitate is washed with water and dried to obtain a solid of the silica particle material; and
With
The surface treatment step includes
A first treatment step of treating the raw silica particles with the silane coupling agent;
A second treatment step of treating the raw silica particles with the organosilazane,
The second treatment step is performed after the first treatment step, and in the latter half, the surface of the raw silica is dry.

The manufacturing method of the granular material of this invention as described in said (9) can add one or more components of following (10)-(12).
(10) In the second treatment step, a part of the organosilazane is replaced with a second silane coupling agent having three alkoxy groups and an alkyl group having 1 to 3 carbon atoms,
After the second treatment step, the method further comprises a third treatment step of treating the silica particles with the organosilazane.

(11) The silane coupling agent is phenyltrimethoxysilane, vinyltrimethoxysilane, epoxytrimethoxysilane, methacryltrimethoxysilane, aminotrimethoxysilane, ureidotrimethoxysilane, mercaptotrimethoxysilane, isocyanate trimethoxysilane, Alternatively, it is at least one selected from acrylic trimethoxysilane.

(12) The organosilazane is at least one selected from tetramethyldisilazane, hexamethyldisilazane, and pentamethyldisilazane.

In this invention, since it has the said structure, the granular material excellent in the handleability can be provided.
In particular, as the silica particle material, X ¹ (phenyl group, vinyl group, epoxy group, phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group) and R (an alkyl group having 1 to 3 carbon atoms) on the surface. Since R, that is, an alkyl group having 1 to 3 carbon atoms has high hydrophobicity, they repel each other. Therefore, since the silica particle material of the thermoplastic resin composition of the present invention is difficult to aggregate due to the repulsive force between alkyl groups having 1 to 3 carbon atoms, particles having high fluidity can be obtained in a dry state. Dispersed well when dispersed.

Further, when the silica particle material has not only R but also X ¹ on the surface, the affinity for a material having a functional group having a large polarity is improved. Such a silica particle material is easily dispersed uniformly in a thermoplastic resin or the like.

6 is a graph showing a TG-DTA measurement result of the silica particle material of Test Example 1. 6 is a graph showing a TG-DTA measurement result of the silica particle material of Test Example 2. It is a graph which shows the applied amount dependence of the transmittance | permeability of the MEK dispersion liquid of Examples 1-3 and Comparative Examples 1 and 2 in Test 3, and a mechanical load. It is a FE-SEM photograph of the sample which added and mixed the granular material of Example 1 and Comparative Examples 1 and 2 to the polystyrene microbeads in Test 5. It is the graph which showed the fluidity | liquidity measured with the powder rheometer about the sample which added and mixed the granular material of Example 1 and Comparative Example 1 to the polystyrene microbead in Test 5, and the polystyrene microbead itself.

The granular material of the present invention and the production method thereof will be described below in detail based on the embodiments. Since the granular material of this embodiment is moderately aggregated, it is excellent in handleability.
The granular material of the present embodiment is made of a silica particle material and is in a dry state. Here, the dry state means that there is no solvent that is not adsorbed on the surface of the particles.

Silica particle material The silica particle material has a volume average particle diameter of primary particles of 1 nm to 100 nm. Further, it is preferable that at least a part is secondary particles dispersible to primary particles by a mechanical load, and preferably “50% or more by mass basis can be dispersed to primary particles”. Moreover, the content rate of a secondary particle is 50% or more on the basis of the whole mass. Furthermore, it has fluidity in the state of secondary particles. The sample of Test Example 1 to be described later forms secondary particles immediately after production, but differs in that it is dispersed to primary particles by applying even a slight mechanical load.

Instead of the determination of “whether at least a part can be dispersed to primary particles by mechanical load” or more, “over 100 mL of a dispersion in which 10% by mass is dispersed in a dispersion medium composed of MEK based on the total mass. After irradiating a sound wave for 5 minutes, it is possible to adopt a judgment of whether or not 95% or more passes when suction filtration is performed with 5 types C filter paper of JISP3801 standard.
Further, it is confirmed that the transmittance (optical path length 1 cm) at a wavelength of 365 nm of the dispersion liquid mixed at a concentration of 10% based on the mass of the dispersion medium composed of methyl ethyl ketone and dispersed for 10 seconds by a shaker is 10% or less. Thus, the determination as to whether or not the particles are secondary particles (having fluidity) can be made.
The transmittance at a wavelength of 365 nm (optical path length 1 cm) of the dispersion liquid mixed at a concentration of 10% based on the mass of the dispersion medium composed of methyl ethyl ketone and dispersed by a wet jet mill at a pressure of 180 MPa is more than 10%. By confirming, it can be replaced with the determination of whether or not the particles can be dispersed to primary particles by a mechanical load.

  Here, the ultrasonic irradiation mentioned above puts dispersion 100mL into (Laboran screw tube No.8: capacity 110mL), MUC-HS-206 made by KOWA GIKEN (vibrator length 30cm x width 18cm x height). 10 cm). Ultrasound irradiation performed to determine whether or not the silica particle material constituting the granular material of the present embodiment is performed under the following conditions. Ultrasonic irradiation is performed by placing a vibrator in a water tank 42 cm long x 32 cm wide x 26 cm high, placing a screw tube thereon, and filling it with water so that it is immersed up to 5 cm from the bottom of the screw tube. The ultrasonic wave has a frequency of 28 kHz and an output of 60 W. The silica particle material employed in the present embodiment is characterized by excellent dispersibility, and is dispersed so that it can pass through the filter paper even under irradiation conditions gentler than the irradiation conditions of this ultrasonic wave. Needless to say, it is included in the scope of the present embodiment.

  The volume average particle size of the silica particle material is desirably 2 nm or more, particularly desirably 5 nm or more, and more desirably 10 nm or more. Moreover, 80 nm or less is desirable and 50 nm or less is more desirable. The surface of the silica particle material is preferably treated with a silane coupling agent, and further preferably treated with organosilazane. The surface treatment is performed so that silanol groups remain on the surface.

It is desirable that the raw silica before the surface treatment and the generated silica particle material have a higher sphericity because fluidity is improved. The sphericity is preferably 0.8 or more, and more preferably 0.9 or more. The sphericity is measured by taking a photograph with an SEM, and calculating the value as (sphericity) = {4π × (area) ÷ (perimeter) ² } from the area and circumference of the observed particle. calculate. The closer to 1, the closer to a true sphere. Specifically, an average value measured for 100 particles randomly extracted using an image processing apparatus (Sysmex Corporation: FPIA-3000) is employed.

  The silica particle material is used for 100 mL of a dispersion in which 10% by mass is dispersed in one or more dispersion media selected from the group consisting of isopropanol, PMG, MEK, ethyl acetate, and toluene based on the total mass. After irradiating with ultrasonic waves for 5 minutes (corresponding to applying a mechanical load), it is preferable that 95% or more pass through when suction filtration is performed with 5 types C filter paper of JISP3801 standard. By this test, the dispersibility in the dispersion can be evaluated. Type 5 C filter paper is a filter paper for fine precipitation, and does not pass through unless it is highly dispersed.

Although it does not specifically limit as a method to give such a dispersibility with respect to a silica particle material, For example, the method (it may use together) mentioned later to the 1 and the 2 is mentioned.
(Part 1)
The silica particle material is a material in which a functional group represented by the formula (1): -OSiX ¹ X ² X ³ and a functional group represented by the formula (2): -OSiY ¹ Y ² Y ³ are bonded to the surface. It is. Particularly, silanol groups remain on the surface. By controlling the amount of remaining silanol groups, the silica particle material of the present embodiment is bonded to a certain degree of strength, but can be dispersed to primary particles by applying a mechanical load. Hereinafter, the functional group represented by the formula (1) is referred to as a first functional group, and the functional group represented by the formula (2) is referred to as a second functional group.

X ¹ in the first functional group is a phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group. X ² and X ³ are —OSiR ₃ or —OSiY ⁴ Y ⁵ Y ⁶ , respectively. Y ⁴ is R. Y ⁵ and Y ⁶ are each R or —OSiR ₃ .

Y ¹ in the second functional group is R. Y ² and Y ³ are each —OSiR ₃ or —OSiY ⁴ Y ⁵ Y ⁶ .
The more —OSiR ₃ contained in the first functional group and the second functional group, the more R on the surface of the silica particle material. The more R (alkyl group having 1 to 3 carbon atoms) contained in the first functional group and the second functional group, the less the silica particle material is aggregated.

Regarding the first functional group, when X ² and X ³ are each —OSiR ₃ , the number of R is minimized. Further, ^{X 2} and ^{X 3} is -OSiY ⁴ Y ⁵ Y ^6, respectively, ^and, if Y 5, ^{Y 6} is -OSiR ₃ respectively, the number of R is maximized.

Regarding the second functional group, when Y ² and Y ³ are each —OSiR ₃ , the number of R is minimized. Further, ^{Y 2} and ^{Y 3} are each a -OSiY ⁴ Y ⁵ Y ^{6, and,} if Y 5, ^{Y 6} is -OSiR ₃ respectively, the number of R is maximized.
The number of X ¹ contained in the first functional group, the number of R contained in the first functional group, and the number of R contained in the second functional group are the abundance ratio of R and X ¹ , silica What is necessary is just to set suitably according to the particle size and use of a particulate material.

^{Incidentally, X 2, X 3, Y} 2, Y 3, Y 5, and any of ^{Y 6, X} 2 of the adjacent ^{functionality, X 3, Y 2, Y} 3, Y 5, and any ^{Y 6} You may combine with heel -O-. For example, any one of the first functional group X ² , X ³ , Y ⁵ , and Y ⁶ is the first functional group adjacent to the first functional group X ² , X ³ , Y ⁵ , and It may be bonded to any of Y ⁶ by —O—. Similarly, any of Y ² , Y ³ , Y ⁵ , and Y ⁶ of the second functional group is replaced with Y ² , Y ³ , Y ⁵ , Y ² of the second functional group adjacent to the second functional group. And Y ⁶ may be bonded to each other by —O—. Furthermore, any one of the first functional groups X ² , X ³ , Y ⁵ , and Y ⁶ is the second functional group adjacent to the first functional group, Y ² , Y ³ , Y ⁵ , And Y ⁶ may be bonded to each other by —O—.

Presence ratio of the first functional groups and second functional groups is 1: 12-1: if 60, the surface of the silica particulate material with X ¹ and R are present good balance. For this reason, when the silica particle material having an abundance ratio of the first functional group to the second functional group of 1:12 to 1:60 is used by being mixed with a resin, it has an affinity and an aggregation suppressing effect. Especially excellent. Further, if X ¹ is 0.5 to 2.5 per unit surface area (nm ² ) of the silica particle material, a sufficient number of first functional groups are bonded to the surface of the silica particle material, and the first There are also a sufficient number of R derived from the functional group and the second functional group. Accordingly, also in this case, the affinity for the resin and the aggregation suppressing effect of the silica particle material are sufficiently exhibited.

In any case, R per unit surface area (nm ² ) of the silica particle material is preferably 1 to 10. In this case, the balance between the number of X ¹ present on the surface of the silica particle material and the number of R is improved, and both the affinity for the resin and the aggregation suppressing effect of the silica particle material are exhibited in a well-balanced manner.

It is preferable that the first functional group or the second functional group is substituted so that part of the silanol groups present on the surface of the silica particles remain. For example, if the sum of the first functional group and the second functional group is less than 2.0 per unit surface area (nm ² ) of the silica particle material, silanol groups are present on the surface of the silica particle in the silica particle material. It can be said that it exists.
The silica particle material has R on the surface. This can be confirmed by an infrared absorption spectrum. Specifically, when the infrared absorption spectrum of the silica particle material is measured by the solid diffuse reflection method, there is a maximum absorption of C—H stretching vibration at 2962 ± 2 cm ⁻¹ . For this reason, it can be confirmed by an infrared absorption spectrum whether it is the silica particle material which the granular material of this embodiment has.

  In addition, even if the silica particle material of this embodiment is agglomerated to secondary particles, it can be dispersed again to primary particles by applying a mechanical load. Specifically, the silica particle material can be substantially dispersed into primary particles by irradiating an ultrasonic wave having an oscillation frequency of 39 kHz and an output of 500 W on a silica particle material dispersed in methyl ethyl ketone. The ultrasonic irradiation time at this time may be 10 minutes or less. Whether or not the silica particle material is dispersed into the primary particles can be confirmed by measuring the particle size distribution. Specifically, when the methyl ethyl ketone dispersion material of the silica particle material is measured with a particle size distribution measuring device such as a microtrack device, and the particle size distribution of the silica particle material is present, it can be said that the silica particle material is dispersed into primary particles.

Since this silica particle material hardly aggregates, it can be provided as a silica particle material that is not dispersed in a liquid medium such as water or alcohol. In addition, since the silica particle material hardly aggregates, it can be easily washed with water.
(Part 2)
It can replace with the silica particle material shown in the 1 and can also adopt the silica particle material which performed the surface treatment shown below. In addition, since the silica particle material (the 1) can also be obtained with the following method, the 1 and the 2 are not exclusive.

The surface treatment method of the silica particle material has a step (surface treatment step) of treating the silica particles with a silane coupling agent and an organosilazane in a liquid medium containing water. The silane coupling agent has three alkoxy groups and a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group (that is, X ¹ described above).

By performing the surface treatment with the silane coupling agent, silanol groups present on the surface of the silica particles are substituted with functional groups derived from the silane coupling agent. The amount of the silane coupling agent for performing the surface treatment is not particularly limited, but may be an amount in which silanol groups on the surface of the silica particle material before the treatment remain. The functional group derived from the silane coupling agent is represented by the formula (3); —OSiX ¹ X ⁴ X ⁵ .

The functional group represented by the formula (3) is referred to as a third functional group. X ¹ in the third functional group is the same as X ¹ in the functional group represented by the formula (1). X ⁴ and X ⁵ are each an alkoxy group. By surface-treating with organosilazane, the third functional group X ⁴ and X ⁵ are derived from organosilazane —OSiY ¹ Y ² Y ³ (the functional group represented by the formula (2), the second functional group ). When all of the silanol groups (hydroxyl groups) present on the surface of the silica particles are not substituted with the third functional group, the silanol groups remaining on the surface of the silica particles are substituted with the second functional group. Therefore, the surface of the surface-treated silica particle material has a functional group represented by the formula (1): —OSiX ¹ X ² X ³ (that is, the first functional group) and a formula (2): —OSiY. ^The functional group represented by ¹ Y ² Y ³ is bonded to the functional group (that is, the second functional group). In addition, since the molar ratio of the silane coupling agent and the organosilazane is silane coupling agent: organosilazane = 1: 2 to 1:10, the first functional group and the second functional group in the obtained silica particle material are used. The abundance ratio with the functional group is theoretically from 1:12 to 1:60.

  In the surface treatment step, the silica particles may be simultaneously surface treated with a silane coupling agent and an organosilazane. Alternatively, the silica particles may first be surface treated with a silane coupling agent and then surface treated with organosilazane. Alternatively, the silica particles may be first surface treated with organosilazane, then surface treated with a silane coupling agent, and then surface treated with organosilazane. In particular, it is desirable to perform treatment with organosilazane after treatment with a silane coupling agent. In addition, it is desirable that the surface of the raw material silica be dried during part of the treatment with organosilazane (particularly in the latter half). Here, “dry” means that the mass loss is 1 mass% or less when heated at 100 ° C. for 1 hour.

In any case, the amount of organosilazane may be adjusted so that all the silanol groups present on the surface of the silica particles are not substituted with the second functional group. The silanol groups present on the surface of the silica particles may all be substituted with the third functional group, or only a part may be substituted with the third functional group, and the other part may be the second functional group. May be substituted. All of X ⁴ and X ⁵ contained in the third functional group may be substituted with the second functional group.

A part of organosilazane may be replaced with the second silane coupling agent. As the second silane coupling agent, one having three alkoxy groups and one alkyl group can be used. In this case, X ⁴ and X ⁵ contained in the third functional group are substituted with the fourth functional group derived from the second silane coupling agent. The fourth functional group has the formula (4); - represented by OSiY ¹ X ⁶ X ^7. Y ¹ is the same R as ^{Y 1} in the second functional ^{group, X 6,} X ⁷ is an alkoxy group or a hydroxyl group, respectively. X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group derived from organosilazane, or are substituted with another fourth functional group. In this case, the amount of R present on the surface of the silica particle material can be further increased. When a part of the organosilazane is replaced with the second silane coupling agent, it is necessary to surface-treat with the organosilazane again after the surface treatment with the second silane coupling agent. This is because X ⁶ and X ⁷ contained in the fourth functional group are finally substituted with the second functional group derived from organosilazane.

When a part of the organosilazane is replaced with the second silane coupling agent, X ⁴ and X ⁵ contained in the first functional group described above are substituted with the second functional group derived from the organosilazane, Substitution with a fourth functional group derived from the second silane coupling agent. When X ⁴ and X ⁵ are substituted with the fourth functional group, X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group or another fourth functional group. Is replaced by If X ^6, X ⁷ contained in the fourth functional group has been replaced by another fourth functional group, X ^6, X ⁷ contained in the fourth functional groups is substituted with the second functional group The For this reason, the second silane coupling agent is an organosilazane set when the surface treatment is performed only with the first coupling agent and the organosilazane (when the organosilazane is not replaced with the second silane coupling agent). A maximum of 5a / 3 mol can be substituted for the amount (a) mol. The amount of organosilazane required in this case is 8a / 3 mol.

  The alkoxy groups of the silane coupling agent and the second silane coupling agent are not particularly limited, but those having a relatively small carbon number are preferred, and those having 1 to 12 carbon atoms are preferred. Considering the hydrolyzability of the alkoxy group, the alkoxy group is more preferably any one of a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Specific examples of silane coupling agents include phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane. 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3 -Aminopropyltrimethoxysilane.

  Any organosilazane may be used as long as it can replace the hydroxyl group present on the surface of the silica particles and the alkoxy group derived from the silane coupling agent with the second functional group described above. preferable. Specific examples include tetramethyldisilazane, hexamethyldisilazane, pentamethyldisilazane, and the like.

Examples of the second silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane.
In the surface treatment step, a polymerization inhibitor may be added in order to suppress polymerization of the silane coupling agent or polymerization of the second silane coupling agent. As the polymerization inhibitor, common ones such as 3,5-dibutyl-4-hydroxytoluene (BHT) and p-methoxyphenol (methoquinone) can be used.

  The surface treatment for obtaining the silica particle material will be described. The surface treatment method may include a solidification step after the surface treatment step. The solidification step is a step of precipitating the surface-treated silica particle material with a mineral acid and washing and drying the precipitate with water to obtain a solid of the silica particle material. The solidification step can also be performed during the surface treatment step (particularly during the treatment with organosilazane). After the solidification step, the surface of the raw material silica is dried and the surface treatment step (treatment with organosilazane) is continued. As described above, since a general silica particle material is very likely to aggregate, it is very difficult to disperse the once solidified silica particle material. However, since the silica particle material is difficult to aggregate, it is difficult to aggregate even if solidified, and it is easy to redisperse even if aggregated. In addition, as mentioned above, the silica particle material used for uses, such as an electronic component, can be easily manufactured by wash | cleaning a silica particle material with water. In the washing step, washing is preferably repeated until the electrical conductivity of the silica particle material extraction water (specifically, the water in which the silica particle material is immersed at 121 ° C. for 24 hours) is 50 μS / cm or less.

  Examples of the mineral acid used in the solidification step include hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and hydrochloric acid is particularly desirable. The mineral acid may be used as it is, but is preferably used as a mineral acid aqueous solution. The concentration of the mineral acid in the aqueous mineral acid solution is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. The amount of the mineral acid aqueous solution can be about 6 to 12 times based on the mass of the silica particle material to be cleaned.

  The cleaning with the mineral acid aqueous solution can be performed a plurality of times. The washing with the mineral acid aqueous solution is preferably performed after the silica particle material is immersed in the mineral acid aqueous solution. Further, it can be left in the immersed state for 1 to 24 hours, and further for about 72 hours. When it is allowed to stand, stirring can be continued or not stirred. When washing in the mineral acid-containing liquid, it can be heated to room temperature or higher.

  Thereafter, the washed and suspended silica particle material is collected by filtration and then washed with water. It is desirable that the water used does not contain ions such as alkali metals (for example, 1 ppm or less on a mass basis). For example, ion exchange water, distilled water, pure water and the like. Washing with water is the same as washing with an aqueous mineral acid solution, after the silica particle material is dispersed and suspended, it can be filtered, or by continuously passing water through the filtered silica particle material. Is possible. The end time of washing with water may be determined by the electric conductivity of the extracted water described above, or may be the time when the alkali metal concentration in the waste water after washing the silica particle material becomes 1 ppm or less, It is good also as the time of the alkali metal concentration of extraction water becoming 5 ppm or less. When washing with water, it can be heated to a room temperature or higher.

  The silica particle material can be dried by a conventional method. For example, heating or leaving under reduced pressure (vacuum).

Hereinafter, the granular material of this invention is demonstrated in detail based on an Example.
(About silica particle material)
Test example 1
(Sample preparation)
As a silica particle used as a raw material, an average particle size of 10 nm, which is a kind of colloidal silica, dispersed in water and having a solid content concentration of 20%) was prepared.
Isopropanol was prepared as the alcohol.
Phenyltrimethoxysilane was prepared as a silane coupling agent.
Hexamethyldisilazane (HMDS) was prepared as organosilazane.

(Surface treatment process)
(1) Preparatory step Silica particles are dispersed in a liquid medium by adding 60 parts by mass of isopropanol to 100 parts by mass of slurry in which silica particles are dispersed in water at a concentration of 20% by mass and mixing at room temperature (about 25 ° C.). A dispersion was obtained.

(2) First Step 1.8 parts by mass of phenyltrimethoxysilane was added to this dispersion and mixed at 40 ° C. for 72 hours. By this step, the hydroxyl group present on the surface of the silica particles was surface treated with a silane coupling agent. At this time, phenyltrimethoxysilane was calculated and added so that a necessary amount of hydroxyl groups (partially) remained without being surface-treated.

(3) Second Step Next, 3.7 parts by mass of hexamethyldisilazane was added to this mixture and left at 40 ° C. for 72 hours. Through this step, the silica particles were surface-treated to obtain a silica particle material. As the surface treatment progressed, the silica particles that became hydrophobic could no longer exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of phenyltrimethoxysilane to hexamethyldisilazane was 2: 5.

(Solidification process)
5 parts by mass of 35% aqueous hydrochloric acid solution was added to the total amount of the mixture obtained in the surface treatment step to precipitate the silica particle material. The precipitate was filtered with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then vacuum-dried for 2 hours to make the surface dry.

(4) Continuation of the second step (third step)
Hexamethyldisilazane was mixed with the dried particles. The amount of hexamethyldisilazane was excessive with respect to silanol groups present on the surface of the particles. After mixing, heating was performed at 200 ° C. for 2 hours.

As a result, 2.5 / nm ² of silanol groups were present on the surface of the silica particle material before the treatment, and 83% of the silanol groups were consumed by these treatments. Surface stability was improved by heating for 2 hours.
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)

  TG-DTA was measured about the obtained silica particle material. The measurement was performed by Rigaku Corporation, Thermo Plus TG8120. The measurement conditions were from 25 ° C. to 800 ° C. at a heating rate of 5 ° C./min. The results are shown in FIG. The mass loss at 350 ° C. was 1.4%.

Test Example 2: Silanol groups remain on the surface and secondary particles are generated (sample preparation)
A silica particle material was obtained without performing the third step in Test Example 1. Before the treatment, 2.5 particles / nm ² of silanol groups were present on the surface of the silica particle material, and 74% of the silanol groups were consumed by these treatments.

(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
The TG-DTA of the obtained silica particle material was measured in the same manner as in Test Example 1. The results are shown in FIG. The mass loss at 350 ° C. was 2.7%.

Test example 3
The same operation as in Test Example 1 was performed except that the final heating (at 200 ° C. for 2 hours) was not performed.
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
The TG-DTA of the obtained silica particle material was measured in the same manner as in Test Example 1. The mass loss at 350 ° C. was 1.7%.

Test example 4
The same operation as in Test Example 1 was performed except that methacrylsilane was used instead of phenyltrimethoxysilane as the silane coupling agent.
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
The TG-DTA of the obtained silica particle material was measured in the same manner as in Test Example 1. An exothermic peak and weight loss associated with thermal decomposition of the methacryl group were observed around 300 ° C., and the mass loss at 350 ° C. was 4% or more.

-Cohesiveness evaluation test About the silica particle material of Test Examples 1-4, the cohesiveness in a liquid medium was measured.
Specifically, in Test Examples 1 to 4, a mixture of 10 g of silica particle material and 40 g of methyl ethyl ketone was stirred to obtain a dispersion sample of silica particle material.
The particle size distribution of the silica particle material contained in each of the obtained dispersion samples was measured with a coarse particle distribution measuring device (manufactured by Nikkiso Co., Ltd., Microtrac).

  It was found that the silica particle materials of Test Examples 1, 3, and 4 were dispersed in a primary particle state without aggregation. This could be confirmed with the naked eye. Test Example 1 is supported by the fact that only one particle size distribution (peak) of the silica particle material appears at a position having a particle diameter of about 10 nm. If the silica particle material is a secondary particle (that is, if there is even agglomeration), at least one peak appears at a position having a particle diameter of 100 nm or more. For this reason, it can be seen that, although the silica particle material of Test Example 1 is once solidified, most of the silica particle material is primary particles and hardly aggregates. In contrast, the silica particle material of Test Example 2 does not disperse only by stirring, and even after ultrasonic stirring at an oscillation frequency of 39 kHz and an output of 500 W for 1 hour or longer, aggregation can be confirmed with the naked eye. Did not disperse.

  The permeability was evaluated when suction filtration was performed with 5 kinds C filter paper of JISP3801 standard. Methyl ethyl ketone was used as the dispersion medium. When 100 mL of a dispersion liquid dispersed in 10% by mass based on the total mass in this dispersion medium was irradiated with ultrasonic waves for 5 minutes and then suction filtered with 5 types C filter paper of JISP3801 standard, 97 in Test Example 1 % Pass, 98% pass in Test Example 2, 98% pass in Test Example 3, and 5% pass in Test Example 4.

(Mixing with thermoplastic resin: Preparation of thermoplastic resin composition)
The thermoplastic resin composition of the present invention will be described below.
・ Test Example A
The same direction rotating twin-screw extruder (HK-25D (41D) manufactured by Parker Corporation) using 60 parts by mass of polyamideimide resin (Tolon Solvay Advanced Polymer) as a thermoplastic resin and 40 parts by mass of silica particle material of Test Example 1. And kneaded at a resin temperature of 250 ° C. to obtain a test sample of this example.

・ Test examples B, C, D
Instead of the silica particle material of Test Example 1, the silica particle material of Test Example 2 (Test Example B), the silica particle material of Test Example 3 (Test Example C), and the silica particle material of Test Example 4 (Test Example D) A test sample of this test example was prepared by kneading in the same manner as in Test Example A except for the use.

(Strength evaluation test and results)
As a result of examining the test samples of Test Examples A to D, it was found that the sample of Test Example A had less coloring (substantially less) than the samples of Test Examples B to D and suppressed deterioration. It was. It was also found that the sample of Test Example A had a better tactile feel and higher strength than the samples of Test Examples B to D even when touched or bent by hand. As a specific strength, when a test piece was prepared and the strength (tensile strength) was measured, the strength was 50% or less based on the strength of the sample of Test Example A. Therefore, it was found that the strength can be maintained even when exposed to high temperature because the weight loss is 1.5% or less.

(Reference test for improving dispersibility)
(Test Example 5)
(material)
As silica particles, colloidal silica (average particle diameter 10 nm, dispersed in water and having a solid content concentration of 20%) was prepared.
Isopropanol was prepared as the alcohol.
Phenyltrimethoxysilane was prepared as a silane coupling agent.

Hexamethyldisilazane was prepared as an organosilazane.
(Surface treatment process)
(1) Preparatory step Silica particles are dispersed in a liquid medium by adding 60 parts by mass of isopropanol to 100 parts by mass of slurry in which silica particles are dispersed in water at a concentration of 20% by mass and mixing at room temperature (about 25 ° C.). A dispersion was obtained.

(2) First Step 1.8 parts by mass of phenyltrimethoxysilane was added to this dispersion and mixed at 40 ° C. for 72 hours. By this step, the hydroxyl group present on the surface of the silica particles was surface treated with a silane coupling agent. At this time, phenyltrimethoxysilane was calculated and added so that a necessary amount of hydroxyl groups (partially) remained without being surface-treated.

(3) Second Step Next, 3.7 parts by mass of hexamethyldisilazane was added to this mixture and left at 40 ° C. for 72 hours. Through this step, the silica particles were surface-treated to obtain a silica particle material. As the surface treatment progressed, the silica particles that became hydrophobic could no longer exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of phenyltrimethoxysilane to hexamethyldisilazane was 2: 5.

(Solidification process)
5 parts by mass of 35% aqueous hydrochloric acid solution was added to the total amount of the mixture obtained in the surface treatment step to precipitate the silica particle material. The precipitate was filtered with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then vacuum dried at 100 ° C. to obtain a solid of silica particle material.

(Test Example 6)
The surface treatment method for silica particles in Test Example 6 uses vinyltrimethoxysilane instead of phenyltrimethoxysilane, except that the molar ratio of vinyltrimethoxysilane and hexamethyldisilazane was 2: 5. This is the same as the surface treatment method for silica particles in Test Example 5. In the first step, 1.36 parts by mass of vinyltrimethoxysilane was added, and in the second step, 3.7 parts by mass of hexamethyldisilazane was added.

(Test Example 7)
The surface treatment method for silica particles in Test Example 7 uses vinyltrimethoxysilane instead of phenyltrimethoxysilane, except that the molar ratio of vinyltrimethoxysilane to hexamethyldisilazane was 1: 5. This is the same as the surface treatment method for silica particles in Test Example 5. In the first step, 1.36 parts by mass of vinyltrimethoxysilane was added, and in the second step, 7.41 parts by mass of hexamethyldisilazane was added.

(Test Example 8)
In the silica particle surface treatment method of Test Example 8, colloidal silica (average particle size 50 nm, solid content concentration of 20% dispersed in water) was used as the silica particles. In the first step, 0.48 parts by mass of 3-methacryloxypropyltrimethoxysilane was added as a silane coupling agent. Further, 0.01 parts by mass of a polymerization inhibitor was added to this silane coupling agent. In the second step, 0.78 parts by mass of hexamethyldisilazane was added. Furthermore, in the solidification step, 2.6 parts by mass of a 35% aqueous hydrochloric acid solution was added to the total amount of the mixture obtained in the surface treatment step to precipitate the silica particle material. Except this, the silica particle surface treatment method of Test Example 8 was the same as the silica particle surface treatment method of Test Example 5. The molar ratio of 3-methacryloxypropyltrimethoxysilane to hexamethyldisilazane was 2: 5.

(Test Example 9)
The silica particle surface treatment method of Test Example 9 is the same as the silica particle surface treatment method of Test Example 5 except that the molar ratio of phenyltrimethoxysilane and hexamethyldisilazane was 1: 1. . In the first step, 4.5 parts by mass of phenyltrimethoxysilane was added, and in the second step, 3.7 parts by mass of hexamethyldisilazane was added.

(Test Example 10)
The silica particle surface treatment method of Test Example 10 was the same as that of Test Example 8 except that the molar ratio of 3-methacryloxypropyltrimethoxysilane to hexamethyldisilazane was 2: 1. Is the same. In the first step, 0.48 parts by mass of 3-methacryloxypropyltrimethoxysilane was added, and in the second step, 0.16 parts by mass of hexamethyldisilazane was added.

(Test Example 11)
The silica particle surface treatment method of Test Example 11 was the same as that of Test Example 8 except that the molar ratio of 3-methacryloxypropyltrimethoxysilane to hexamethyldisilazane was 1: 1. Is the same. In the first step, 0.48 parts by mass of 3-methacryloxypropyltrimethoxysilane was added, and in the second step, 0.31 parts by mass of hexamethyldisilazane was added.

(Cohesiveness evaluation test)
About the silica particle material of Test Examples 5-11, the aggregability in a liquid medium was measured.
Specifically, in Test Examples 5 to 7 and Test Example 9, a mixture of 10 g of silica particle material and 40 g of methyl ethyl ketone was stirred to obtain a dispersion sample of silica particle material.

  For Test Examples 8, 10, and 11, a mixture of 10 g of silica particle material and 10 g of methyl ethyl ketone was stirred to obtain a dispersion sample of silica particle material. The particle size distribution of the silica particle material contained in each of the obtained dispersion samples was measured with a particle size distribution measuring device (Nikkiso Co., Ltd., Microtrac).

  As a result, it was found that the silica particle materials of Test Examples 5 to 8 were dispersed in a state of primary particles without aggregation. This is supported by the fact that the particle size distribution (peak) of each of the silica particle materials of Test Examples 5 to 8 appears only at a position having a particle diameter of about 10 nm to 50 nm. If the silica particle material is secondary particles (that is, if there is even agglomeration), at least one peak appears at a position having a particle diameter of 100 nm or more. For this reason, although the silica particle material of Test Examples 5-8 was once solidified, it turns out that most are primary particles and hardly aggregated. On the other hand, the silica particle materials of Test Examples 9 to 11 are not dispersed only by stirring, and even after ultrasonic stirring at an oscillation frequency of 39 kHz and an output of 500 W for 1 hour or more, aggregation can be confirmed with the naked eye. It did not disperse to primary particles. From this result, it can be seen that by making the molar ratio of the silane coupling agent and the organosilazane in the range of 1: 2 to 1:10, it is possible to produce a silica particle material that hardly aggregates even when solidified. The average particle size of the silica particle material of Test Example 5 is 10 nm, the average particle size of the silica particle material of Test Example 6 is 10 nm, the average particle size of the silica particle material of Test Example 7 is 10 nm, and the silica particles of Test Example 8 The average particle size of the material was 50 nm. From this result, it can be seen that the molar ratio of the silane coupling agent to the organosilazane is preferably in the range of 1: 5 to 2: 5 in order to suppress aggregation.

(Maximum absorption measurement test)
The silica particle materials of Test Examples 5 to 11 were prepared, and the infrared absorption spectrum of this sample was measured by a powder diffuse reflection method using FT-IR Avatar manufactured by Thermo Nicolet. The measurement conditions at this time were a resolution of 4 and a scan count of 64. As a result, the infrared absorption spectra of the silica particle materials of Test Examples 5 to 11 all have a maximum absorption (peak) of C—H stretching vibration at 2962 cm ⁻¹ . For this reason, it can be seen that these silica particle materials have an alkyl group (that is, are surface-treated with an organosilazane having an alkyl group). In addition, the peak height of the silica particle material of Test Examples 9 to 11 was lower than the peak height of the silica particle material of Test Examples 5 to 8. This result suggests that the silica particle materials of Test Examples 9 to 11 do not have a sufficient amount of alkyl groups. Specifically, in the infrared absorption spectra of the silica particle materials of Test Examples 5 to 8, the methyl group (2962 cm) derived from organosilazane with respect to the peak height of C—H specific to each functional group derived from the silane coupling agent. The peak height of ^-1 ) was 3 times or more. In the infrared absorption spectra of the silica particle materials of Test Examples 9 to 11, methyl group (2962 cm ⁻¹ ) derived from organosilazane with respect to the peak height of C—H specific to each functional group derived from the silane coupling agent. The peak height was 2 times or less. As described above, the silica particle materials of Test Examples 5 to 8 were hardly aggregated, and the silica particle materials of Test Examples 9 to 11 were easily aggregated. From these results, silica whose peak height of methyl group (2962 cm ⁻¹ ) derived from organosilazane is three times or more than the peak height of C—H specific to each functional group derived from the silane coupling agent. It can be said that the particulate material hardly aggregates.

(Carbon content measurement test)
About the silica particle material of Test Examples 5-11, the quantity (mass%) of the carbon which exists per mass of a silica particle material was measured. For the measurement, an organic carbon measuring device (HORIBA, EMIA-320V) was used.

  As a result, the carbon amount of the silica particle material of Test Example 5 is 3.5% by mass, the carbon amount of the silica particle material of Test Example 6 is 2.6% by mass, and the carbon of the silica particle material of Test Example 7 is The amount was 2.8% by mass, and the amount of carbon in the silica particle material of Test Example 8 was 0.96% by mass. The carbon amount of the silica particle material of Test Example 9 is 4.0% by mass, the carbon amount of the silica particle material of Test Example 10 is 1.8% by mass, and the carbon amount of the silica particle material of Test Example 11 is 1%. It was 0.0 mass%.

(X ¹ number measurement test)
For the silica particle materials of Test Examples 5 to 11, the number of X ¹ present per unit surface area (nm ² ) of the silica particle material was measured. Test Example 5 and X ¹ in the silica particulate material in Test Example 9 is a phenyl group, X ¹ in the silica particulate material in Test Example 6 and 7 is a vinyl group, in the silica particle material in Test Example 8, 10 and 11 X ¹ was a methacryloxy group. The surface area (specific surface area) of the silica particle material was measured by the BET method using nitrogen. The number of X ¹ was calculated based on the carbon content of the silica particle material. Specifically, the silica particles after the first step were washed with water, centrifuged and then dried to obtain a silica particle sample after the silane coupling agent treatment. The carbon content of this sample was measured using an organic carbon measuring device, and the number of X ¹ was calculated based on the measured value.

As a result, the number of X ¹ in the silica particle material of Test Example 5 was about 1.2 / nm ² . The number of X ¹ in the silica particle material of Test Example 6 was about 1.1 / nm ² . The number of X ¹ in the silica particle material of Test Example 7 was about 1.1 / nm ² . The number of X ¹ in the silica particle material of Test Example 8 was about 2.0 / nm ² . The number of X ¹ in the silica particle material of Test Example 9 was about 1.7 pieces / nm ² . The number of X ¹ in the silica particle material of Test Example 10 was about 2.0 / nm ² . The number of X ¹ in the silica particle material of Test Example 11 was about 2.0 / nm ² . For reference, the carbon content of the silica particle sample after the silane coupling agent treatment was 3.6% by mass for the silica particle material of Test Example 5, 1.1% by mass for the silica particle material of Test Example 6, and Test Example 7 The silica particle material was 1.1% by mass, and the silica particle material of Test Example 8 was 1.5% by mass. The silica particle material of Test Example 9 was 5.0% by mass, the silica particle material of Test Example 10 was 1.5% by mass, and the silica particle material of Test Example 11 was 1.5% by mass.

As described above, the affinity of the silica particle material to the resin material differs depending on the number and type of X ¹ , and the silica particle material of Test Example 5 and the silica particle material of Test Example 8 were excellent in affinity to the resin material. . From this result, in order to exhibit excellent affinity for the resin material, X ¹ per unit surface area (nm ² ) of the silica particle material is preferably 0.5 to 2.5, It can be said that 1.0 to 2.0 is more preferable.

(Regarding powder particles containing secondary particles)
Examples 1 to 3
A silica particle material was obtained in the same manner as in Test Example 2. In Example 1, the amount of the silane coupling agent was adjusted so that the silanol group was 36%, the silanol group was 37% in Example 2, and the silanol group was 40% in Example 3. In order to increase the remaining amount of silanol groups, it was possible to reduce the reaction amount of the silane coupling agent.

Comparative example 1
The silica particle material of Test Example 1 was used as it was.
Comparative example 2
A test sample was prepared after the first step of Test Example 1 (first silane coupling agent: treatment with phenyltrimethoxysilane). The amount of the silane coupling agent added was excessive so that it could sufficiently react with the silanol groups present on the surface.

・ Test 1
It added to MEK so that solid content concentration might be 10 mass%, and it shaked for 10 seconds with the shaker. The transmittance of the obtained dispersion liquid at a wavelength of 365 nm was measured with a spectrophotometer.
As a result, it was found that in the dispersions of Examples 1 to 3 and Comparative Example 2, the transmittance was 0.1% and aggregation was maintained. In the dispersion liquid of Comparative Example 1, it was found that the secondary particles were crushed and highly dispersed with a transmittance of 85.9%.

・ Test 2
Each dispersion liquid of Test 1 (Example 1, Comparative Examples 1 and 2) was pulverized by a wet jet mill. The wet jet mill used a 100V-compatible desktop type wet atomizer [Sugino Machine Co., Ltd., product name: starburst minimo, model number: HJP_25001SE (pressure range: 1-245 MPa)] (same in this specification). The treatment conditions were a 2 pass treatment at a pressure of 150 MPa and a 5 pass treatment at a pressure of 180 MPa.
As a result, in Comparative Example 1, the transmittance was not changed to 85.9%, but in Example 1, it was greatly improved to 19.5%, and it was found that secondary particles can be crushed and dispersed into primary particles. In Comparative Example 2, it was only slightly increased to 0.4%.

・ Test 3
Each of the dispersions of Test 1 (Examples 1 to 3, Comparative Examples 1 and 2) was pulverized by a wet jet mill. Processing conditions were a pressure of 180 MPa.
As a result, the transmittance was 85.2% in Comparative Example 1 and 0.3% in Comparative Example 2. In Example 1, it was 63.9%, in Example 2, 44.9%, and in Example 3, it was 75.8%. The larger the amount of silanol groups remaining on the surface, the more permeated under the same mechanical load conditions. The rate was found to be low.

FIG. 3 shows the result of increasing the treatment with a wet jet mill in order to further increase the mechanical load. As apparent from FIG. 3, it was found that the transmittance gradually increased and improved from 70 to 80% as the mechanical load increased, that is, the dispersion from the secondary particles to the primary particles proceeded. That is, it was found that by allowing silanol groups to remain on the surface, it is possible to provide a granular material that initially maintains the form of secondary particles but can be dispersed into primary particles by applying a mechanical load.
In addition, Comparative Example 1 showed a high transmittance by being dispersed almost to the limit by one treatment of 1 MPa. In other words, it was found that it was very easy to disperse. In Comparative Example 2, it was found that even when the treatment was performed at a pressure of 245 MPa, the transmittance was hardly improved and there was almost no dispersibility. In Examples 1 to 3, there were treatment conditions in which the transmittance value gradually increased by repeated treatment within the range of treatment conditions (1 to 245 MPa) that can be carried out by this wet jet mill. Here, the transmittance gradually improves under the processing conditions that can be adopted by the wet jet mill adopted in this specification. (A) In general handling, the improvement in dispersibility is small and the secondary particles remain as they are. It was speculated that it has two characteristics: (b) improvement in dispersibility to primary particles can be realized by a mechanical load having a realistic size as required.

・ Test 4
The sample of Example 1 (solid content concentration 30%) was treated with a wet jet mill at a pressure of 200 MPa. As a result, the transmittance was 0.21% at 1 pass, the transmittance was 0.59% at 5pass, and the transmittance was 3.32 at 10pass. % And dispersibility can be improved.

・ Test 5
After adding 0.5% of the granular material of Example 1, Comparative Example 1 and 2 to polystyrene microbeads (PS: volume average particle diameter of about 6 μm) based on the mass of PS, mixing for 2 minutes with a mixer did. FE-SEM photographs were taken for each mixture (Figure 4). Moreover, the granular material of Example 1 was added, the granular material of the comparative example 1 was added, and fluidity | liquidity evaluation was performed for each of PS itself with the powder rheometer (FIG. 5).
As a result, as is clear from FIG. 4, it was found that PS was highly dispersed in Example 1 and Comparative Example 1. On the other hand, in Comparative Example 2, aggregation of PS was observed. This was supported by the results in FIG. That is, both Example 1 and Comparative Example 1 showed high fluidity.

・ Summary of Tests 1-5 From the results of Test 1, Comparative Example 1 in which all the silanol groups on the surface were substituted by reaction can be quickly dispersed in MEK even by human power, whereas in Example 1, it cannot be dispersed by human power. It was found that secondary particles were formed by aggregation with strength. This was the same as Comparative Example 2 in which the surface was simply hydrophobized.

  From the results of Test 2, it was found that the dispersibility of the granular material of Example 1 can be improved by increasing the mechanical load. In addition, it is clear from the results of tests 3 and 4 that the dispersibility is improved by increasing the amount of mechanical load, which is necessary by increasing the mechanical load (either by manpower or using the device). It was found that it was possible to approach dispersibility.

  From the results of Test 5, it was found that the improvement in dispersibility (pulverization of secondary particles) due to mechanical load can proceed in the powder of Example 1 even under dry conditions. Therefore, it was found that the secondary particles can be kept in a state before use to prevent scattering, and can be quickly dispersed in the primary particles during use.

(Reference: Description just before the split)
[Title of Invention] Thermoplastic resin composition and method for producing the same
[Technical field]
[0001]
The present invention relates to silica particles suitable for dispersion in a thermoplastic resin and a thermoplastic resin composition containing the silica particles.
[Background technology]
[0002]
Conventionally, a thermosetting resin composition containing a silica particle material in a thermosetting resin is known. By including the silica particle material in the thermosetting resin, the heat resistance can be improved with respect to the resin composition, or the physical strength can be improved.
[0003]
Here, colloidal silica which is a kind of silica particle material is produced by a method of producing water glass as a raw material, a method of producing metal silicon powder as a raw material, a gas phase synthesis method, or the like. In the method of producing water glass as a raw material, fine particles are generated by neutralizing the water glass or precipitating the water glass by ion exchange (see, for example, Patent Document 1).
[0004]
The particle size of such silica particle material is very small, for example, about several nanometers to several hundred nanometers in colloidal silica. Such silica particle material is mixed in a thermosetting resin and used for a transparent material. It has been applied to use in filling very small gaps.
[0005]
The mixing of the silica particle material and the thermosetting resin is usually performed on the thermosetting resin before curing (hereinafter sometimes referred to as “thermosetting resin precursor”). The silica particle material may be subjected to surface treatment for the purpose of improving the affinity with the thermosetting resin.
[0006]
The silica particle material having a small particle diameter described above has a very large specific surface area. For this reason, silica particles with a small particle diameter have the characteristic of being easily aggregated. Once agglomerated silica particles are difficult to redisperse. For this reason, the silica particle with a small particle size has a problem inferior in handleability.
[0007]
Therefore, when mixing the silica particle material having a small particle size and the thermosetting resin, the silica particle material is mixed with the thermosetting resin precursor in a dispersion state dispersed in some dispersion medium, and then the dispersion medium is removed. Things have been done.
[Prior art documents]
[Patent Literature]
[0008]
[Patent Document 1] JP-A-2006-45039
[Summary of Invention]
[Problems to be solved by the invention]
[0009]
By the way, there is a demand for realizing heat resistance and the like not only for thermosetting resins but also for thermoplastic resins. In that case, it is conceivable to improve heat resistance by mixing silica particle material.
[0010]
It is difficult for the silica particle material to be mixed at that time to be mixed in the thermoplastic resin in the state of a dispersion dispersed in a dispersion medium. Unlike the thermosetting resin, which is a low molecular compound before being cured and handled with a low molecular state thermosetting resin precursor, the thermoplastic resin is handled by being melted and heated in the state of a high molecular compound. The dispersion medium mixed in the thermoplastic resin cannot be easily removed.
[0011]
Therefore, it has been difficult to easily produce a thermoplastic resin composition in which a silica particle material having a small particle size is dispersed in a thermoplastic resin.
[0012]
Furthermore, the inventors of the present application have found that when the mixed silica particle material is heated to a high temperature, moisture is released to cause deterioration of the resin.
[0013]
This invention is made | formed in view of the said situation, and makes it the subject which should be solved to provide the thermoplastic resin composition which can disperse | distribute the silica particle material in a thermoplastic resin easily, and has little thermal deterioration. .
[Means for solving problems]
[0014]
As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, a silica particle material having a small particle size was prepared so as to be able to pass through a predetermined filter paper in a dispersion state after a predetermined surface treatment. The product was found to have high fluidity even in the dry state. In particular, the silica particle material produced by the wet method was excellent in dispersibility in the thermoplastic resin composition.
[0015]
However, some thermoplastic resin compositions employing silica particle material produced by a wet method have insufficient heat resistance. For example, even when heated to about 200 ° C., resin deterioration may have progressed.
[0016]
As a result of examining cases where the heat resistance is not sufficient, it was discovered that a dehydration reaction due to heat between silanol groups present on the surface of the silica particle material is involved as a cause of resin degradation due to heating. In other words, it was found that the water generated by the dehydration reaction is released into the resin and reacts with the resin to contribute to deterioration.
[0017]
Based on these findings, it is desirable to improve heat resistance while maintaining the desirable property of silica particle material produced by a wet method, which is “low aggregation and excellent dispersibility” (that is, by heating such as dehydration reaction). For the purpose of reducing the influence on the resin by the substance produced by the proceeding reaction, the surface treatment agent was positively bonded to the silanol group. As a result, it was found that the thermal decomposition of the silanol group can be suppressed and the heat resistance when applied to a resin can be improved.
(1) The present invention has been completed based on the above knowledge, and the surface of the raw silica having a volume average particle diameter of 1 nm to 100 nm is treated with a silane coupling agent and an organosilazane, and the silane Heat treatment is performed at a temperature lower than the decomposition temperature of the coupling agent, and the mass loss when heated from room temperature to 350 ° C. at a rate of temperature increase of 5 ° C./min is 1.5% by mass or less. Isopropanol, PMG, MEK After irradiating ultrasonic waves for 5 minutes to 100 mL of a dispersion in which 10% by mass is dispersed in one or more dispersion media selected from the group consisting of ethyl acetate and toluene based on the total mass, Silica particle material that passes 95% or more when suction filtered with 5 types C filter paper of JISP3801 standard,
A thermoplastic resin in which the silica particle material is dispersed;
It is characterized by having.
[0018]
The types of silane coupling agents and organosilazanes used for the surface treatment, and combinations thereof, are combined so that the mass decrease upon heating up to 350 ° C. under the above-described conditions is 1.5% by mass or less. The determination of whether the mass loss is reduced when each surface treatment agent is used can be predicted to some extent by the decomposition temperature of the surface treatment agent itself.
[0019]
Here, the ultrasonic irradiation mentioned above puts dispersion 100mL into (Laboran screw tube No.8: capacity 110mL), MUC-HS-206 made by KOWA GIKEN (vibrator length 30cm x width 18cm x height). 10 cm). The ultrasonic irradiation performed to determine whether or not the silica particle material is employed in the thermoplastic resin composition of the present invention is performed under the following conditions. Ultrasonic irradiation is performed by placing a vibrator in a water tank 42 cm long x 32 cm wide x 26 cm high, placing a screw tube thereon, and filling it with water so that it is immersed up to 5 cm from the bottom of the screw tube. The ultrasonic wave has a frequency of 28 kHz and an output of 60 W. The silica particle material employed in the present invention is characterized by excellent dispersibility, and may be dispersed so that it can pass through the filter paper even under irradiation conditions gentler than the ultrasonic irradiation conditions. Needless to say, it is included in the scope of the present invention.
[0020]
The thermoplastic resin composition of the present invention preferably has the following constitution (2), (3), (4), or (8).
(2) At least a part of the treatment with the organosilazane is after the treatment with the silane coupling agent, the raw silica is in a dry state, and the organosilazane is more than the silanol groups remaining on the raw silica surface. Processing is performed so that the amount becomes excessive.
(3) The thermoplastic resin is polyethylene, polypropylene, polymethyl acrylate, polymethyl methacrylate, polycarbonate, nylon, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, cellulose acetate, polyvinyl chloride, polyvinyl alcohol, polystyrene, poly One or more resin materials selected from the group consisting of lactic acid and polyimide.
(4) The silica particle material has the formula (1): -OSiX ¹ X ² X ³ And a functional group represented by formula (2): -OSiY ¹ Y ² Y ³ And a silica particle in which both functional groups are bonded to the surface. In the above formulas (1) and (2); X ¹ Is a phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group; X ² , X ³ Is -OSiR ₃ And -OSiY ⁴ Y ⁵ Y ⁶ Each independently selected; Y ¹ Is R; Y ² , Y ³ Are R and -OSiY ⁴ Y ⁵ Y ⁶ Are selected independently. Y ⁴ Is R; Y ⁵ And Y ⁶ R and -OSiR ₃ R is independently selected from alkyl groups having 1 to 3 carbon atoms. X ² , X ³ , Y ² , Y ³ , Y ⁵ And Y ⁶ Either of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ And Y ⁶ You may couple | bond with either of these by -O-.
(8) The raw material silica material is treated by a surface treatment method having a surface treatment step of treating the raw material silica particles with a silane coupling agent and an organosilazane in a liquid medium containing water,
The silane coupling agent has three alkoxy groups, a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group,
The molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10.
[0021]
When the configuration (4) is added, it is preferable to include at least one of (5) to (7).
(5) The abundance ratio between the functional group represented by the formula (1) and the functional group represented by the formula (2) is 1:12 to 1:60.
(6) X ¹ Is the unit surface area of the silica particle material (nm ² 0.5 to 2.5 pieces).
(7) R is a unit surface area (nm) of the silica particle material. ² 1) per 1).
[0022]
When the configuration (8) is added, it is preferable to include at least one of (9) to (13).
(9) The surface treatment step has a first treatment step of treating the raw silica particles with the silane coupling agent and a second treatment step of treating the raw silica particles with the organosilazane, The second treatment step is performed after the first treatment step, and in the latter half, the surface of the raw silica is dry.
(10) In the second treatment step, a part of the organosilazane is replaced with a second silane coupling agent having three alkoxy groups and an alkyl group having 1 to 3 carbon atoms, and the second treatment step Later, the method further includes a third treatment step of treating the silica particles with the organosilazane.
(11) After the surface treatment step, the method includes a solidification step of precipitating the silica particle material with a mineral acid and washing and drying the precipitate with water to obtain a solid of the silica particle material.
(12) The silane coupling agent is phenyltrimethoxysilane, vinyltrimethoxysilane, epoxytrimethoxysilane, methacryltrimethoxysilane, aminotrimethoxysilane, ureidotrimethoxysilane, mercaptotrimethoxysilane, isocyanate trimethoxysilane, Alternatively, it is at least one selected from acrylic trimethoxysilane.
(13) The organosilazane is at least one selected from tetramethyldisilazane, hexamethyldisilazane, and pentamethyldisilazane.
[Effect of the invention]
[0023]
In this invention, since it has the said structure, the moisture content produced | generated from silica particle material origin can be reduced, and a thermoplastic resin composition with high heat resistance can be provided. That is, by performing the heat treatment at a temperature lower than the decomposition temperature of the silane coupling agent used for the surface treatment, less heat is generated from the silica particle material in advance, and the influence on the resin can be reduced.
[0024]
Moreover, the thermoplastic resin composition in which the silica particle material having a small particle diameter is stably dispersed in the thermoplastic resin can be provided. Since the silica particle material having a small particle size is well dispersed in the thermoplastic resin, it has sufficient transparency even when processed into a film or the like.
[0025]
In particular, as the silica particle material contained in the thermoplastic resin composition, X ¹ (Phenyl group, vinyl group, epoxy group, phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group) and R (alkyl group having 1 to 3 carbon atoms) ) On the surface. Since R, that is, an alkyl group having 1 to 3 carbon atoms has high hydrophobicity, they repel each other. Therefore, since the silica particle material of the thermoplastic resin composition of the present invention is difficult to aggregate due to the repulsive force between alkyl groups having 1 to 3 carbon atoms, particles having high fluidity can be obtained in a dry state. Dispersed well when dispersed.
[0026]
Further, the silica particle material has not only R on the surface but also X ¹ In the case of having also, the affinity for a material having a functional group having a large polarity is improved. Such a silica particle material is easily dispersed uniformly in the thermoplastic resin. Silica particle material is X ¹ Since it has a surface on the surface, it has excellent affinity with the thermoplastic resin and can be uniformly dispersed in the thermoplastic resin.
[0027]
Moreover, the more the R exists on the surface of the silica particle material, the more the aggregation suppressing effect is improved. On the other hand, the affinity for the thermoplastic resin is lowered. X on the surface of silica particle material ¹ As the amount of A is increased, the affinity for the thermoplastic resin is improved. On the other hand, the number of R is reduced and the aggregation suppressing effect is reduced. Therefore, R and X ¹ There is a preferred range for the abundance ratio. If the abundance ratio of the functional group represented by the formula (1) and the functional group represented by the formula (2) is within the range of 1:12 to 1:60, the resin has excellent affinity and excellent It is possible to achieve both an aggregation suppressing effect. X ¹ Is the unit surface area of the silica particle material (nm ² If the number is 0.5 to 2.5, it is possible to achieve both excellent affinity for the resin and excellent aggregation suppressing effect.
[Brief description of drawings]
[0028]
FIG. 1 is a graph showing the TG-DTA measurement results of the silica particle material of Test Example 1.
FIG. 2 is a graph showing the TG-DTA measurement results of the silica particle material of Test Example 2.
[Mode for Carrying Out the Invention]
[0029]
The thermoplastic resin composition of the present invention will be described in detail below based on the embodiment. Since the thermoplastic resin composition of this embodiment contains a silica particle material, it is excellent in physical strength and dimensional stability against heat. Therefore, very high performance can be exhibited by using it as an optical material. In addition, the thermoplastic resin composition of the present embodiment can be used for battery separators and the like. The thermoplastic resin composition of this embodiment is excellent in heat resistance and mechanical strength, and can be suitably used for applications as so-called engineering plastics. For example, it is possible to achieve about 350 ° C. as heat resistance.
[0030]
The thermoplastic resin composition of this embodiment has a silica particle material and a thermoplastic resin in which it is dispersed. The mixing ratio of the thermoplastic resin and the silica particle material is not particularly limited, but the content of the silica particle material is preferably 5% or more based on the whole (sum of the mass of the silica particle material and the thermoplastic resin). More preferably, the content is 10% or more. Furthermore, the content is preferably 60% or less, and more preferably 50% or less.
[0031]
The mixing of the silica particle material and the thermoplastic resin is a method of melting the thermoplastic resin in a polymer state by heating and mixing with the silica particle material in that state, or the silica particle material when polymerizing the thermoplastic resin. The method of making it coexist is mentioned. When mixing the thermoplastic resin in a molten state, a method of mixing using a general kneader can be exemplified.
[0032]
It is desirable that the silica particle material be mixed with the thermoplastic resin in a dry state because mixing of the dispersion medium can be suppressed. Here, the dry state means that there is no solvent that is not adsorbed on the surface of the particles. Specifically, it can be easily determined whether or not it is in a dry state based on whether or not it has fluidity in a state where it is not in a slurry state when the inorganic powder mixture is handled. If it has fluidity in a state where it is not in a slurry, it can be determined that it is in a dry state.
[0033]
・ Silica particle material
The silica particle material is a material obtained by treating raw material silica, which is a particle made of silica having a volume average particle diameter of 1 nm to 100 nm. The thickness is desirably 2 nm or more, particularly desirably 5 nm or more, and more desirably 10 nm or more. Moreover, 80 nm or less is desirable and 50 nm or less is more desirable. The silica particle material, which is a particle obtained by subjecting the raw material silica to surface treatment, has a particle size larger than that of the raw material silica, but it is desirable to have a particle size similar to that of the raw material silica. The surface is treated with a silane coupling agent and organosilazane. And heat processing are performed at the temperature below the decomposition temperature of the employ | adopted silane coupling agent. Even if the obtained thermoplastic resin composition is heated to that temperature because of the heat treatment at a temperature lower than the decomposition temperature, generation of a heated product (for example, generation of moisture due to the progress of the dehydration reaction) occurs. It can suppress and the deterioration of the thermoplastic resin composition by the heating product can be suppressed. The heating time is not particularly limited. This is because the heating can be performed to remove even a slight amount of heated product from the silica particle material. As a desirable heating time, it is confirmed that no mass change occurs even if heating is performed at the heating temperature (200 ° C.) (as a confirmation method, a mass change of 1.5% by mass or more is observed even if heating is performed for 2 hours. Examples of usable silane coupling agents include silane coupling agents with aromatic groups such as benzene rings and naphthalene such as phenyl silane and styryl silane having a decomposition temperature of 300 ° C. or higher, and cyclic or linear silane coupling agents. A silane coupling agent having a siloxane functional group can be exemplified.
[0034]
It is desirable that both the raw silica and the produced silica particle material have a higher sphericity because the fluidity is improved. The sphericity is preferably 0.8 or more, and more preferably 0.9 or more. To measure the sphericity, take a picture with SEM, and from the observed particle area and circumference, (sphericity) = {4π x (area) ÷ (perimeter) ² } Is calculated as a value calculated in {}. The closer to 1, the closer to a true sphere. Specifically, an average value measured for 100 particles randomly extracted using an image processing apparatus (Sysmex Corporation: FPIA-3000) is employed.
[0035]
The silica particle material is used for 100 mL of a dispersion in which 10% by mass is dispersed in one or more dispersion media selected from the group consisting of isopropanol, PMG, MEK, ethyl acetate, and toluene based on the total mass. After irradiating with ultrasonic waves for 5 minutes, 95% or more passes when suction filtration is performed with 5 kinds C filter paper of JISP3801 standard. By this test, the dispersibility in the dispersion can be evaluated. Type 5 C filter paper is a filter paper for fine precipitation, and does not pass through unless it is highly dispersed.
[0036]
Although it does not specifically limit as a method to give such a dispersibility with respect to a silica particle material, For example, the method (it may use together) mentioned later to the 1 and the 2 is mentioned.
[0037]
(Part 1)
The silica particle material has the formula (1): -OSiX ¹ X ² X ³ And a functional group represented by formula (2): -OSiY ¹ Y ² Y ³ And a functional group represented by the formula: In particular, there is substantially no silanol group on the surface (1 nm ² 0.5 or less per unit) is desirable. Hereinafter, the functional group represented by the formula (1) is referred to as a first functional group, and the functional group represented by the formula (2) is referred to as a second functional group.
[0038]
X in the first functional group ¹ Is a phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group. X ² , X ³ Are respectively -OSiR ₃ Or -OSiY ⁴ Y ⁵ Y ⁶ It is. Y ⁴ Is R. Y ⁵ , Y ⁶ Are respectively R or -OSiR ₃ It is.
[0039]
Y in the second functional group ¹ Is R. Y ² , Y ³ Are respectively -OSiR ₃ Or -OSiY ⁴ Y ⁵ Y ⁶ It is.
[0040]
-OSiR contained in the first functional group and the second functional group ₃ The greater the amount, the greater the amount of R on the surface of the silica particle material. The more R (alkyl group having 1 to 3 carbon atoms) contained in the first functional group and the second functional group, the less the silica particle material is aggregated.
[0041]
Regarding the first functional group, X ² , X ³ Each -OSiR ₃ The number of R is minimized. X ² And X ³ -OSiY ⁴ Y ⁵ Y ⁶ And Y ⁵ , Y ⁶ Each -OSiR ₃ The number of R is maximized.
[0042]
Regarding the second functional group, Y ² , Y ³ Each -OSiR ₃ The number of R is minimized. Y ² And Y ³ -OSiY ⁴ Y ⁵ Y ⁶ And Y ⁵ , Y ⁶ Each one-OSiR ₃ The number of R is maximized.
[0043]
X contained in the first functional group ¹ , The number of R contained in the first functional group, and the number of R contained in the second functional group are R and X ¹ May be set as appropriate according to the ratio of the number of particles and the particle size of the silica particle material and the application.
[0044]
X ² , X ³ , Y ² , Y ³ , Y ⁵ And Y ⁶ Either of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ And Y ⁶ You may couple | bond with either of these by -O-. For example, X of the first functional group ² , X ³ , Y ⁵ And Y ⁶ Are any of the X of the first functional group adjacent to the first functional group. ² , X ³ , Y ⁵ And Y ⁶ It may be bonded to any one of -O-. Similarly, Y of the second functional group ² , Y ³ , Y ⁵ And Y ⁶ Any of Y of the second functional group adjacent to the second functional group ² , Y ³ , Y ⁵ And Y ⁶ It may be bonded to any one of -O-. Furthermore, X of the first functional group ² , X ³ , Y ⁵ And Y ⁶ Any of Y of the second functional group adjacent to the first functional group ² , Y ³ , Y ⁵ And Y ⁶ It may be bonded to any one of -O-.
[0045]
If the ratio of the number of the first functional group and the second functional group is 1:12 to 1:60, X is present on the surface of the silica particle material. ¹ And R are in good balance. For this reason, the silica particle material whose abundance ratio between the first functional group and the second functional group is 1:12 to 1:60 is particularly excellent in the affinity for the resin and the aggregation suppressing effect. X ¹ Is the unit surface area of the silica particle material (nm ² If the number is 0.5 to 2.5, a sufficient number of first functional groups are bonded to the surface of the silica particle material, and R derived from the first functional group and the second functional group is also There are enough numbers. Accordingly, also in this case, the affinity for the resin and the aggregation suppressing effect of the silica particle material are sufficiently exhibited.
[0046]
In any case, the unit surface area of the silica particle material (nm ² R) is preferably 1 to 10. In this case, X present on the surface of the silica particle material. ¹ The balance between the number of and the number of R is improved, and both the affinity for the resin and the aggregation suppressing effect of the silica particle material are exhibited in a balanced manner.
[0047]
It is preferable that all of the hydroxyl groups present on the surface of the silica particles are substituted with the first functional group or the second functional group. The sum of the first functional group and the second functional group is the unit surface area (nm) of the silica particle material. ² If the number is 2.0 or more, it can be said that in the silica particle material, almost all of the hydroxyl groups present on the surface of the silica particles are substituted with the first functional group or the second functional group.
[0048]
The silica particle material has R on the surface. This can be confirmed by an infrared absorption spectrum. Specifically, when the infrared absorption spectrum of the silica particle material is measured by the solid diffuse reflection method, it is 2962 ± 2 cm. ^-1 There is a maximum absorption of C-H stretching vibration. For this reason, whether or not the inorganic powder mixture of the present embodiment is a silica particle material can be confirmed by an infrared absorption spectrum.
[0049]
Further, as described above, the silica particle material of the inorganic powder mixture of the present invention is difficult to agglomerate. Therefore, it can employ | adopt as a silica particle material with a small particle size. For example, the silica particle material can have an average particle size of about 3 nm to 5000 nm. It is preferable to apply to a silica particle material having an average particle diameter of 3 to 200 nm.
[0050]
Note that the silica particle material can be dispersed again by ultrasonic treatment even if it is slightly agglomerated. Specifically, the silica particle material can be substantially dispersed into primary particles by irradiating an ultrasonic wave having an oscillation frequency of 39 kHz and an output of 500 W on a silica particle material dispersed in methyl ethyl ketone. The ultrasonic irradiation time at this time may be 10 minutes or less. Whether or not the silica particle material is dispersed into the primary particles can be confirmed by measuring the particle size distribution. Specifically, when the methyl ethyl ketone dispersion material of the silica particle material is measured with a particle size distribution measuring device such as a microtrack device, and the particle size distribution of the silica particle material is present, it can be said that the silica particle material is dispersed into primary particles.
[0051]
Since this silica particle material hardly aggregates, it can be provided as a silica particle material that is not dispersed in a liquid medium such as water or alcohol. In addition, since the silica particle material hardly aggregates, it can be easily washed with water.
[0052]
(Part 2)
It can replace with the silica particle material shown in the 1 and can also adopt the silica particle material which performed the surface treatment shown below. In addition, since the silica particle material (the 1) can also be obtained with the following method, the 1 and the 2 are not exclusive.
[0053]
The surface treatment method of the silica particle material has a step (surface treatment step) of treating the silica particles with a silane coupling agent and an organosilazane in a liquid medium containing water. The silane coupling agent includes three alkoxy groups, a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group (that is, the above X ¹ ) And have.
[0054]
By performing the surface treatment with the silane coupling agent, the hydroxyl group present on the surface of the silica particles is substituted with a functional group derived from the silane coupling agent. The amount of the silane coupling agent for performing the surface treatment is not particularly limited, but can be an amount capable of reacting with 80% or more of the silanol groups on the surface of the silica particle material before the treatment. In particular, 2.5 silanol groups / nm on the surface of the silica particle material before the reaction ² When present to some extent, the remaining silanol groups are 0.5 / nm by reacting at least 80%. ² The amount of water generated by the dehydration reaction can be sufficiently suppressed. The functional group derived from the silane coupling agent has the formula (3); ¹ X ⁴ X ⁵ It is represented by The functional group represented by the formula (3) is referred to as a third functional group. X in the third functional group ¹ Is X in the functional group represented by the formula (1) ¹ Is the same. X ⁴ , X ⁵ Are each an alkoxy group. By surface-treating with organosilazane, the third functional group X ⁴ , X ⁵ -OSiY derived from organosilazane ¹ Y ² Y ³ It is substituted with (functional group represented by formula (2), second functional group). When all of the hydroxyl groups present on the surface of the silica particles are not substituted with the third functional group, the hydroxyl groups remaining on the surface of the silica particles are substituted with the second functional group. Therefore, the surface of the surface-treated silica particle material has the formula (1): -OSiX ¹ X ² X ³ And a functional group represented by formula (2): -OSiY ¹ Y ² Y ³ (Ie, the second functional group) is bonded to the functional group represented by In addition, since the molar ratio of the silane coupling agent and the organosilazane is silane coupling agent: organosilazane = 1: 2 to 1:10, the first functional group and the second functional group in the obtained silica particle material are used. The abundance ratio with the functional group is theoretically from 1:12 to 1:60.
[0055]
In the surface treatment step, the silica particles may be simultaneously surface treated with a silane coupling agent and an organosilazane. Alternatively, the silica particles may first be surface treated with a silane coupling agent and then surface treated with organosilazane. Alternatively, the silica particles may be first surface treated with organosilazane, then surface treated with a silane coupling agent, and then surface treated with organosilazane. In particular, it is desirable to perform treatment with organosilazane after treatment with a silane coupling agent. In addition, it is desirable that the surface of the raw material silica be dried during part of the treatment with organosilazane (particularly in the latter half). Here, “dry” means that the mass loss is 1 mass% or less when heated at 100 ° C. for 1 hour.
[0056]
In any case, the amount of organosilazane may be adjusted so that all the hydroxyl groups present on the surface of the silica particles are not substituted with the second functional group. The hydroxyl groups present on the surface of the silica particles may all be substituted with the third functional group, or only a part may be substituted with the third functional group, and the other part may be substituted with the second functional group. It may be replaced. X contained in the third functional group ⁴ , X ⁵ Are all preferably substituted with a second functional group.
[0057]
A part of organosilazane may be replaced with the second silane coupling agent. As the second silane coupling agent, one having three alkoxy groups and one alkyl group can be used. In this case, X contained in the third functional group ⁴ , X ⁵ Is substituted with a fourth functional group derived from the second silane coupling agent. The fourth functional group has the formula (4); -OSiY ¹ X ⁶ X ⁷ It is represented by Y ¹ Is Y in the second functional group ¹ Is the same R and X ⁶ , X ⁷ Are each an alkoxy group or a hydroxyl group. X contained in the fourth functional group ⁶ , X ⁷ Is substituted with a second functional group derived from an organosilazane or with another fourth functional group. In this case, the amount of R present on the surface of the silica particle material can be further increased. When a part of the organosilazane is replaced with the second silane coupling agent, it is necessary to surface-treat with the organosilazane again after the surface treatment with the second silane coupling agent. X contained in the fourth functional group ⁶ , X ⁷ Is finally substituted with a second functional group derived from organosilazane.
[0058]
When a part of the organosilazane is replaced with the second silane coupling agent, X contained in the first functional group described above ⁴ , X ⁵ Is substituted with a second functional group derived from an organosilazane or a fourth functional group derived from a second silane coupling agent. X ⁴ , X ⁵ Is substituted with the fourth functional group, X contained in the fourth functional group ⁶ , X ⁷ Is substituted with a second functional group or with another fourth functional group. X contained in the fourth functional group ⁶ , X ⁷ Is substituted by another fourth functional group, X contained in the fourth functional group ⁶ , X ⁷ Is substituted with a second functional group. For this reason, the second silane coupling agent is an organosilazane set when the surface treatment is performed only with the first coupling agent and the organosilazane (when the organosilazane is not replaced with the second silane coupling agent). A maximum of 5a / 3 mol can be substituted for the amount (a) mol. The amount of organosilazane required in this case is 8a / 3 mol.
[0059]
The alkoxy groups of the silane coupling agent and the second silane coupling agent are not particularly limited, but those having a relatively small carbon number are preferred, and those having 1 to 12 carbon atoms are preferred. Considering the hydrolyzability of the alkoxy group, the alkoxy group is more preferably any one of a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
[0060]
Specific examples of silane coupling agents include phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane. 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3 -Aminopropyltrimethoxysilane.
[0061]
Any organosilazane may be used as long as it can replace the hydroxyl group present on the surface of the silica particles and the alkoxy group derived from the silane coupling agent with the second functional group described above. preferable. Specific examples include tetramethyldisilazane, hexamethyldisilazane, pentamethyldisilazane, and the like.
[0062]
Examples of the second silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane.
[0063]
In the surface treatment step, a polymerization inhibitor may be added in order to suppress polymerization of the silane coupling agent or polymerization of the second silane coupling agent. As the polymerization inhibitor, common ones such as 3,5-dibutyl-4-hydroxytoluene (BHT) and p-methoxyphenol (methoquinone) can be used.
[0064]
The surface treatment for obtaining the silica particle material will be described. The surface treatment method may include a solidification step after the surface treatment step. The solidification step is a step of precipitating the surface-treated silica particle material with a mineral acid and washing and drying the precipitate with water to obtain a solid of the silica particle material. The solidification step can also be performed during the surface treatment step (particularly during the treatment with organosilazane). After the solidification step, the surface of the raw material silica is dried and the surface treatment step (treatment with organosilazane) is continued. As described above, since a general silica particle material is very likely to aggregate, it is very difficult to disperse the once solidified silica particle material. However, since the silica particle material is difficult to aggregate, it is difficult to aggregate even if solidified, and it is easy to redisperse even if aggregated. In addition, as mentioned above, the silica particle material used for uses, such as an electronic component, can be easily manufactured by wash | cleaning a silica particle material with water. In the washing step, washing is preferably repeated until the electrical conductivity of the silica particle material extraction water (specifically, the water in which the silica particle material is immersed at 121 ° C. for 24 hours) is 50 μS / cm or less.
[0065]
Examples of the mineral acid used in the solidification step include hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and hydrochloric acid is particularly desirable. The mineral acid may be used as it is, but is preferably used as a mineral acid aqueous solution. The concentration of the mineral acid in the aqueous mineral acid solution is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. The amount of the mineral acid aqueous solution can be about 6 to 12 times based on the mass of the silica particle material to be cleaned.
[0066]
The cleaning with the mineral acid aqueous solution can be performed a plurality of times. The washing with the mineral acid aqueous solution is preferably performed after the silica particle material is immersed in the mineral acid aqueous solution. Further, it can be left in the immersed state for 1 to 24 hours, and further for about 72 hours. When it is allowed to stand, stirring can be continued or not stirred. When washing in the mineral acid-containing liquid, it can be heated to room temperature or higher.
[0067]
Thereafter, the washed and suspended silica particle material is collected by filtration and then washed with water. It is desirable that the water used does not contain ions such as alkali metals (for example, 1 ppm or less on a mass basis). For example, ion exchange water, distilled water, pure water and the like. Washing with water is the same as washing with an aqueous mineral acid solution, after the silica particle material is dispersed and suspended, it can be filtered, or by continuously passing water through the filtered silica particle material. Is possible. The end time of washing with water may be determined by the electric conductivity of the extracted water described above, or may be the time when the alkali metal concentration in the waste water after washing the silica particle material becomes 1 ppm or less, It is good also as the time of the alkali metal concentration of extraction water becoming 5 ppm or less. When washing with water, it can be heated to a room temperature or higher.
[0068]
The silica particle material can be dried by a conventional method. For example, heating or leaving under reduced pressure (vacuum).
[0069]
·Thermoplastic resin
The thermoplastic resin is not particularly limited as long as it is a resin material that is melted or softened by heating. When the thermoplastic resin composition of the present embodiment is used for applications requiring transparency, it is desirable to employ a material having low crystallinity. The thermoplastic resin may be a material that can cause a crosslinking reaction or the like by some reaction, and loses the thermoplasticity after the reaction. For example, there is a functional group that can be cross-linked in the chemical structure, and the functional group reacts under conditions other than the conditions under which the thermoplastic resin melts (heating above the melting temperature, irradiation with high energy rays (light, radiation, etc.)) To do.
[0070]
Thermoplastic resins include polyethylene, polypropylene, polymethyl acrylate, polymethyl methacrylate, polycarbonate, nylon, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, cellulose acetate, polyvinyl chloride, polyvinyl alcohol, polystyrene, polylactic acid, polyimide Examples of the resin material are as follows. Among these, it can employ | adopt as an alloy which was individual or mixed 2 or more types. Furthermore, it can also be set as the copolymer which copolymerized the monomer which comprises each resin material.
[0071]
It is desirable to perform the surface modification of the silica particle material described above according to the material selected as the thermoplastic resin. For example, a functional group having an affinity for the thermoplastic resin can be imparted to the surface of the silica particle material.
[Example]
[0072]
Hereinafter, the thermoplastic resin composition of the present invention will be described in detail based on examples.
(About the silica particle material contained in the thermoplastic resin composition of the present invention)
Test example 1
(Sample preparation)
As silica particles, colloidal silica (average particle diameter 10 nm, dispersed in water and having a solid content concentration of 20%) was prepared.
Isopropanol was prepared as the alcohol.
Phenyltrimethoxysilane was prepared as a silane coupling agent.
Hexamethyldisilazane was prepared as an organosilazane.
[0073]
(Surface treatment process)
(1) Preparation process
60 parts by mass of isopropanol is added to 100 parts by mass of slurry in which silica particles are dispersed in water at a concentration of 20% by mass, and the mixture is mixed at room temperature (about 25 ° C.) to obtain a dispersion in which silica particles are dispersed in a liquid medium. Obtained.
[0074]
(2) First step
To this dispersion, 1.8 parts by mass of phenyltrimethoxysilane was added and mixed at 40 ° C. for 72 hours. By this step, the hydroxyl group present on the surface of the silica particles was surface treated with a silane coupling agent. At this time, phenyltrimethoxysilane was calculated and added so that a necessary amount of hydroxyl groups (partially) remained without being surface-treated.
[0075]
(3) Second step
Next, 3.7 parts by mass of hexamethyldisilazane was added to the mixture, and the mixture was allowed to stand at 40 ° C. for 72 hours. Through this step, the silica particles were surface-treated to obtain a silica particle material. As the surface treatment progressed, the silica particles that became hydrophobic could no longer exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of phenyltrimethoxysilane to hexamethyldisilazane was 2: 5.
[0076]
(3) Solidification process
5 parts by mass of 35% aqueous hydrochloric acid solution was added to the total amount of the mixture obtained in the surface treatment step to precipitate the silica particle material. The precipitate was filtered with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then vacuum-dried for 2 hours to make the surface dry.
[0077]
(4) Continuation of the second step (third step)
Hexamethyldisilazane was mixed with the dried particles. The amount of hexamethyldisilazane was excessive with respect to silanol groups present on the surface of the particles. After mixing, heating was performed at 200 ° C. for 2 hours.
[0078]
As a result, the surface of the silica particle material is 2.5 particles / nm before processing. ² Of silanol groups were present and 83% of the silanol groups were consumed by these treatments. Surface stability was improved by heating for 2 hours.
[0079]
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
TG-DTA was measured about the obtained silica particle material. The measurement was performed by Rigaku Corporation, Thermo Plus TG8120. The measurement conditions were from 25 ° C. to 800 ° C. at a heating rate of 5 ° C./min. The results are shown in FIG. The mass loss at 350 ° C. was 1.4%.
[0080]
Test example 2
(Sample preparation)
A silica particle material was obtained without performing the third step in Test Example 1. The surface of the silica particle material is 2.5 particles / nm before processing. ² Of silanol groups were present and 74% of the silanol groups were consumed by these treatments.
[0081]
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
The TG-DTA of the obtained silica particle material was measured in the same manner as in Test Example 1. The results are shown in FIG. The mass loss at 350 ° C. was 2.7%.
[0082]
Test example 3
The same operation as in Test Example 1 was performed except that the final heating (at 200 ° C. for 2 hours) was not performed.
[0083]
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
The TG-DTA of the obtained silica particle material was measured in the same manner as in Test Example 1. The mass loss at 350 ° C. was 1.7%.
[0084]
Test example 4
The same operation as in Test Example 1 was performed except that methacrylsilane was used instead of phenyltrimethoxysilane as the silane coupling agent.
[0085]
(Differential heat-thermogravimetric simultaneous measurement (TG-DTA) measurement)
The TG-DTA of the obtained silica particle material was measured in the same manner as in Test Example 1. An exothermic peak and weight loss associated with thermal decomposition of the methacryl group were observed around 300 ° C., and the mass loss at 350 ° C. was 4% or more.
[0086]
・ Cohesion evaluation test
About the silica particle material of Test Examples 1-4, the cohesion in a liquid medium was measured.
Specifically, in Test Examples 1 to 4, a mixture of 10 g of silica particle material and 40 g of methyl ethyl ketone was stirred to obtain a dispersion sample of silica particle material.
The particle size distribution of the silica particle material contained in each of the obtained dispersion samples was measured with a coarse particle distribution measuring device (manufactured by Nikkiso Co., Ltd., Microtrac).
It was found that the silica particle materials of Test Examples 1, 3, and 4 were dispersed in a primary particle state without aggregation. This could be confirmed with the naked eye. Test Example 1 is supported by the fact that only one particle size distribution (peak) of the silica particle material appears at a position having a particle diameter of about 10 nm. If the silica particle material is a secondary particle (that is, if there is even agglomeration), at least one peak appears at a position having a particle diameter of 100 nm or more. For this reason, it can be seen that, although the silica particle material of Test Example 1 is once solidified, most of the silica particle material is primary particles and hardly aggregates. In contrast, the silica particle material of Test Example 2 does not disperse only by stirring, and even after ultrasonic stirring at an oscillation frequency of 39 kHz and an output of 500 W for 1 hour or longer, aggregation can be confirmed with the naked eye. Did not disperse.
[0087]
The permeability was evaluated when suction filtration was performed with 5 kinds C filter paper of JISP3801 standard. Methyl ethyl ketone was used as the dispersion medium. When 100 mL of a dispersion liquid dispersed in 10% by mass based on the total mass in this dispersion medium was irradiated with ultrasonic waves for 5 minutes and then suction filtered with 5 types C filter paper of JISP3801 standard, 97 in Test Example 1 % Pass, 98% pass in Test Example 2, 98% pass in Test Example 3, and 5% pass in Test Example 4.
[0088]
(Mixing with thermoplastic resin: Preparation of thermoplastic resin composition)
The thermoplastic resin composition of the present invention will be described below.
[0089]
・ Test Example A
The same direction rotating twin-screw extruder (HK-25D (41D) manufactured by Parker Corporation) using 60 parts by mass of polyamideimide resin (Tolon Solvay Advanced Polymer) as a thermoplastic resin and 40 parts by mass of silica particle material of Test Example 1. And kneaded at a resin temperature of 250 ° C. to obtain a test sample of this example.
[0090]
・ Test examples B, C, D
Instead of the silica particle material of Test Example 1, the silica particle material of Test Example 2 (Test Example B), the silica particle material of Test Example 3 (Test Example C), and the silica particle material of Test Example 4 (Test Example D) A test sample of this test example was prepared by kneading in the same manner as in Test Example A except for the use.
[0091]
(Strength evaluation test and results)
As a result of examining the test samples of Test Examples A to D, it was found that the sample of Test Example A had less coloring (substantially less) than the samples of Test Examples B to D and suppressed deterioration. It was. It was also found that the sample of Test Example A had a better tactile feel and higher strength than the samples of Test Examples B to D even when touched or bent by hand. As a specific strength, when a test piece was prepared and the strength (tensile strength) was measured, the strength was 50% or less based on the strength of the sample of Test Example A. Therefore, it was found that the strength can be maintained even when exposed to high temperature because the weight loss is 1.5% or less.
[0092]
(Reference test for improving dispersibility)
(Test Example 5)
(material)
As silica particles, colloidal silica (average particle diameter 10 nm, dispersed in water and having a solid content concentration of 20%) was prepared.
Isopropanol was prepared as the alcohol.
Phenyltrimethoxysilane was prepared as a silane coupling agent.
Hexamethyldisilazane was prepared as an organosilazane.
[0093]
(Surface treatment process)
(1) Preparation process
60 parts by mass of isopropanol is added to 100 parts by mass of slurry in which silica particles are dispersed in water at a concentration of 20% by mass, and the mixture is mixed at room temperature (about 25 ° C.) to obtain a dispersion in which silica particles are dispersed in a liquid medium. Obtained.
[0094]
(2) First step
To this dispersion, 1.8 parts by mass of phenyltrimethoxysilane was added and mixed at 40 ° C. for 72 hours. By this step, the hydroxyl group present on the surface of the silica particles was surface treated with a silane coupling agent. At this time, phenyltrimethoxysilane was calculated and added so that a necessary amount of hydroxyl groups (partially) remained without being surface-treated.
[0095]
(3) Second step
Next, 3.7 parts by mass of hexamethyldisilazane was added to the mixture, and the mixture was allowed to stand at 40 ° C. for 72 hours. Through this step, the silica particles were surface-treated to obtain a silica particle material. As the surface treatment progressed, the silica particles that became hydrophobic could no longer exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of phenyltrimethoxysilane to hexamethyldisilazane was 2: 5.
[0096]
(Solidification process)
5 parts by mass of 35% aqueous hydrochloric acid was added to the total amount of the mixture obtained in the surface treatment step to precipitate the silica particle material. The precipitate was filtered with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then vacuum dried at 100 ° C. to obtain a solid of silica particle material.
[0097]
(Test Example 6)
The surface treatment method for silica particles in Test Example 6 uses vinyltrimethoxysilane instead of phenyltrimethoxysilane, except that the molar ratio of vinyltrimethoxysilane and hexamethyldisilazane was 2: 5. This is the same as the surface treatment method for silica particles in Test Example 5. In the first step, 1.36 parts by mass of vinyltrimethoxysilane was added, and in the second step, 3.7 parts by mass of hexamethyldisilazane was added.
[0099]
(Test Example 7)
The surface treatment method for silica particles in Test Example 7 uses vinyltrimethoxysilane instead of phenyltrimethoxysilane, except that the molar ratio of vinyltrimethoxysilane to hexamethyldisilazane was 1: 5. This is the same as the surface treatment method for silica particles in Test Example 5. In the first step, 1.36 parts by mass of vinyltrimethoxysilane was added, and in the second step, 7.41 parts by mass of hexamethyldisilazane was added.
[0100]
(Test Example 8)
In the silica particle surface treatment method of Test Example 8, colloidal silica (average particle size 50 nm, solid content concentration of 20% dispersed in water) was used as the silica particles. In the first step, 0.48 parts by mass of 3-methacryloxypropyltrimethoxysilane was added as a silane coupling agent. Further, 0.01 parts by mass of a polymerization inhibitor was added to this silane coupling agent. In the second step, 0.78 parts by mass of hexamethyldisilazane was added. Furthermore, in the solidification step, 2.6 parts by mass of a 35% aqueous hydrochloric acid solution was added to the total amount of the mixture obtained in the surface treatment step to precipitate the silica particle material. Except this, the silica particle surface treatment method of Test Example 8 was the same as the silica particle surface treatment method of Test Example 5. The molar ratio of 3-methacryloxypropyltrimethoxysilane to hexamethyldisilazane was 2: 5.
[0101]
(Test Example 9)
The silica particle surface treatment method of Test Example 9 is the same as the silica particle surface treatment method of Test Example 5 except that the molar ratio of phenyltrimethoxysilane and hexamethyldisilazane was 1: 1. . In the first step, 4.5 parts by mass of phenyltrimethoxysilane was added, and in the second step, 3.7 parts by mass of hexamethyldisilazane was added.
[0102]
(Test Example 10)
The silica particle surface treatment method of Test Example 10 was the same as that of Test Example 8 except that the molar ratio of 3-methacryloxypropyltrimethoxysilane to hexamethyldisilazane was 2: 1. Is the same. In the first step, 0.48 parts by mass of 3-methacryloxypropyltrimethoxysilane was added, and in the second step, 0.16 parts by mass of hexamethyldisilazane was added.
[0103]
(Test Example 11)
The silica particle surface treatment method of Test Example 11 was the same as that of Test Example 8 except that the molar ratio of 3-methacryloxypropyltrimethoxysilane to hexamethyldisilazane was 1: 1. Is the same. In the first step, 0.48 parts by mass of 3-methacryloxypropyltrimethoxysilane was added, and in the second step, 0.31 parts by mass of hexamethyldisilazane was added.
[0104]
(Cohesiveness evaluation test)
About the silica particle material of Test Examples 5-11, the aggregability in a liquid medium was measured.
[0105]
Specifically, in Test Examples 5 to 7 and Test Example 9, a mixture of 10 g of silica particle material and 40 g of methyl ethyl ketone was stirred to obtain a dispersion sample of silica particle material.
[0106]
For Test Examples 8, 10, and 11, a mixture of 10 g of silica particle material and 10 g of methyl ethyl ketone was stirred to obtain a dispersion sample of silica particle material. The particle size distribution of the silica particle material contained in each of the obtained dispersion samples was measured by a particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., Microtrac).
[0107]
As a result, it was found that the silica particle materials of Test Examples 5 to 8 were dispersed in a state of primary particles without aggregation. This is supported by the fact that the particle size distribution (peak) of each of the silica particle materials of Test Examples 5 to 8 appears only at a position having a particle diameter of about 10 nm to 50 nm. If the silica particle material is a secondary particle (that is, if there is even agglomeration), at least one peak appears at a position having a particle diameter of 100 nm or more. For this reason, although the silica particle material of Test Examples 5-8 was once solidified, it turns out that most are primary particles and hardly aggregated. On the other hand, the silica particle materials of Test Examples 9 to 11 are not dispersed only by stirring, and even after ultrasonic stirring at an oscillation frequency of 39 kHz and an output of 500 W for 1 hour or more, aggregation can be confirmed with the naked eye. It did not disperse to primary particles. From this result, it can be seen that by making the molar ratio of the silane coupling agent and the organosilazane in the range of 1: 2 to 1:10, it is possible to produce a silica particle material that hardly aggregates even when solidified. The average particle size of the silica particle material of Test Example 5 is 10 nm, the average particle size of the silica particle material of Test Example 6 is 10 nm, the average particle size of the silica particle material of Test Example 7 is 10 nm, and the silica particles of Test Example 8 The average particle size of the material was 50 nm. From this result, it can be seen that the molar ratio of the silane coupling agent to the organosilazane is preferably in the range of 1: 5 to 2: 5 in order to suppress aggregation.
[0108]
(Maximum absorption measurement test)
The silica particle materials of Test Examples 5 to 11 were prepared, and the infrared absorption spectrum of this sample was measured by a powder diffuse reflection method using FT-IR Avatar manufactured by Thermo Nicolet. The measurement conditions at this time were a resolution of 4 and a scan count of 64. As a result, the infrared absorption spectra of the silica particle materials of Test Examples 5 to 11 are both 2962 cm. ^-1 Has maximum absorption (peak) of C—H stretching vibration. For this reason, it can be seen that these silica particle materials have an alkyl group (that is, are surface-treated with an organosilazane having an alkyl group). In addition, the peak height of the silica particle material of Test Examples 9 to 11 was lower than the peak height of the silica particle material of Test Examples 5 to 8. This result suggests that the silica particle materials of Test Examples 9 to 11 do not have a sufficient amount of alkyl groups. Specifically, in the infrared absorption spectra of the silica particle materials of Test Examples 5 to 8, the methyl group (2962 cm) derived from organosilazane with respect to the peak height of C—H specific to each functional group derived from the silane coupling agent. ^-1 ) Was 3 times or more. In the infrared absorption spectra of the silica particle materials of Test Examples 9 to 11, methyl groups (2962 cm) derived from organosilazane with respect to the peak height of C—H specific to each functional group derived from the silane coupling agent. ^-1 ) Was 2 times or less. As described above, the silica particle materials of Test Examples 5 to 8 were hardly aggregated, and the silica particle materials of Test Examples 9 to 11 were easily aggregated. From these results, methyl groups (2962 cm) derived from organosilazane with respect to the peak height of C—H specific to each functional group derived from the silane coupling agent. ^-1 It can be said that the silica particle material having a peak height of 3) or more is less likely to aggregate.
[0109]
(Carbon content measurement test)
About the silica particle material of Test Examples 5-11, the quantity (mass%) of the carbon which exists per mass of a silica particle material was measured. For the measurement, an organic carbon measuring device (HORIBA, EMIA-320V) was used.
[0110]
As a result, the carbon amount of the silica particle material of Test Example 5 is 3.5% by mass, the carbon amount of the silica particle material of Test Example 6 is 2.6% by mass, and the carbon of the silica particle material of Test Example 7 is The amount was 2.8% by mass, and the amount of carbon in the silica particle material of Test Example 8 was 0.96% by mass. The carbon amount of the silica particle material of Test Example 9 is 4.0% by mass, the carbon amount of the silica particle material of Test Example 10 is 1.8% by mass, and the carbon amount of the silica particle material of Test Example 11 is 1%. It was 0.0 mass%.
[0111]
(X ¹ Number measurement test)
About the silica particle material of Test Examples 5 to 11, the unit surface area (nm) of the silica particle material ² X) ¹ The abundance of was measured. X in the silica particle material of Test Example 5 and Test Example 9 ¹ Is a phenyl group, and X in the silica particle material of Test Examples 6 and 7 ¹ Is a vinyl group and X in the silica particle materials of Test Examples 8, 10, and 11 ¹ Was a methacryloxy group. The surface area (specific surface area) of the silica particle material was measured by the BET method using nitrogen. X ¹ Was calculated based on the carbon content of the silica particle material. Specifically, the silica particles after the first step were washed with water, centrifuged and then dried to obtain a silica particle sample after the silane coupling agent treatment. The carbon content of this sample was measured using an organic carbon measuring device, and X was calculated based on the measured value. ¹ Numbers were calculated.
[0112]
As a result, X in the silica particle material of Test Example 5 ¹ The number is about 1.2 / nm ² Met. X in the silica particle material of Test Example 6 ¹ The number is about 1.1 / nm ² Met. X in the silica particle material of Test Example 7 ¹ The number is about 1.1 / nm ² Met. X in the silica particle material of Test Example 8 ¹ Number is about 2.0 / nm ² Met. X in the silica particle material of Test Example 9 ¹ The number is about 1.7 pieces / nm. ² Met. X in the silica particle material of Test Example 10 ¹ Number is about 2.0 / nm ² Met. X in the silica particle material of Test Example 11 ¹ Number is about 2.0 / nm ² Met. For reference, the carbon content of the silica particle sample after the silane coupling agent treatment was 3.6% by mass for the silica particle material of Test Example 5, 1.1% by mass for the silica particle material of Test Example 6, and Test Example 7 The silica particle material was 1.1% by mass, and the silica particle material of Test Example 8 was 1.5% by mass. The silica particle material of Test Example 9 was 5.0% by mass, the silica particle material of Test Example 10 was 1.5% by mass, and the silica particle material of Test Example 11 was 1.5% by mass.
[0113]
As described above, the affinity of the silica particle material to the resin material is X ¹ The silica particle material of Test Example 5 and the silica particle material of Test Example 8 were excellent in affinity for the resin material. From this result, in order to exhibit excellent affinity for the resin material, the unit surface area (nm) of the silica particle material ² X) ¹ Is preferably 0.5 to 2.5, more preferably 1.0 to 2.0.

(Reference: Claims immediately before the division)
[Claim 1]
Mass when the surface is treated with a silane coupling agent and organosilazane with respect to raw silica having a volume average particle diameter of 1 nm to 100 nm and heated from room temperature to 350 ° C. at a rate of temperature increase of 5 ° C./min. After irradiating ultrasonic waves for 5 minutes to 100 mL of a dispersion having a reduction of 1.5% by mass or less and 10% by mass dispersed in a dispersion medium composed of MEK based on the total mass, 5 types C of JISP3801 standard Silica particle material that passes 95% or more when suction filtered with filter paper,
A thermoplastic resin in which the silica particle material is dispersed;
A thermoplastic resin composition.
[Claim 2]
The functional group derived from the organosilazane is bonded to at least a part of the functional group derived from the silane coupling agent, and the functional group derived from the silane coupling agent or the organosilazane is bonded to all the silanol groups derived from the raw material silica. The thermoplastic resin composition according to claim 1, wherein the groups are substantially bonded.
[Claim 3]
The thermoplastic resin is polyethylene, polypropylene, polymethyl acrylate, polymethyl methacrylate, polycarbonate, nylon, polyurethane, polytetrafluoroethylene, polyethylene terephthalate, cellulose acetate, polyvinyl chloride, polyvinyl alcohol, polystyrene, polylactic acid, and The thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic resin composition is one or more resin materials selected from the group consisting of polyimides.
[Claim 4]
The silica particle material has the formula (1): -OSiX ¹ X ² X ³ And a functional group represented by formula (2): -OSiY ¹ Y ² Y ³ The thermoplastic resin composition according to any one of claims 1 to 3, comprising a functional group represented by formula (1) and silica particles in which both functional groups are bonded to the surface. (In the above formulas (1) and (2); X ¹ Is a phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group; X ² , X ³ Are -OSiR3 and -OSiY ⁴ Y ⁵ Y ⁶ Each independently selected; Y ¹ Is R; Y ² , Y ³ Are R and -OSiY ⁴ Y ⁵ Y ⁶ Are selected independently. Y ⁴ Is R; Y ⁵ And Y ⁶ Are independently selected from R and —OSiR 3; R is independently selected from alkyl groups having 1 to 3 carbon atoms. X ² , X ³ , Y ² , Y ³ , Y ⁵ And Y ⁶ Either of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ And Y ⁶ You may couple | bond with either of these by -O-. )
[Claim 5]
The thermoplastic resin composition according to claim 4, wherein the abundance ratio of the functional group represented by the formula (1) and the functional group represented by the formula (2) is 1:12 to 1:60.
[Claim 6]
X ¹ Is the unit surface area of the silica particle material (nm ² The thermoplastic resin composition according to claim 4 or 5, wherein the number is 0.5 to 2.5.
[Claim 7]
R is a unit surface area (nm) of the silica particle material. ² 1 to 10 thermoplastic resin compositions according to any one of claims 4 to 6.
[Claim 8]
The silane coupling agent has three alkoxy groups, a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group,
The thermoplastic resin according to any one of claims 1 to 7, wherein a molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10. Composition.
[Claim 9]
A method for producing the thermoplastic resin composition according to any one of claims 1 to 8,
The raw silica material is a surface treatment step of surface-treating raw silica particles with a silane coupling agent and organosilazane in a liquid medium containing water;
After the surface treatment step, the silica particle material is precipitated with a mineral acid, and the precipitate is washed with water and dried to obtain a solid of the silica particle material; and
Heat treatment at a temperature lower than the decomposition temperature of the silane coupling agent;
With
The surface treatment step includes
A first treatment step of treating the raw silica particles with the silane coupling agent;
A second treatment step of treating the raw silica particles with the organosilazane,
The method for producing a thermoplastic resin composition, wherein the second treatment step is performed after the first treatment step, and the surface of the raw silica is dried in the latter half.
[Claim 10]
In the second treatment step, a part of the organosilazane is replaced with a second silane coupling agent having three alkoxy groups and an alkyl group having 1 to 3 carbon atoms,
The method for producing a thermoplastic resin composition according to claim 9, further comprising a third treatment step of treating the silica particles with the organosilazane after the second treatment step.
[Claim 11]
The silane coupling agent is phenyltrimethoxysilane, vinyltrimethoxysilane, epoxytrimethoxysilane, methacryltrimethoxysilane, aminotrimethoxysilane, ureidotrimethoxysilane, mercaptotrimethoxysilane, isocyanatetrimethoxysilane, or acrylictrimethoxysilane. The method for producing a thermoplastic resin composition according to claim 9 or 10, which is at least one selected from methoxysilane.
[Claim 12]
The method for producing a thermoplastic resin composition according to any one of claims 9 to 11, wherein the organosilazane is at least one selected from tetramethyldisilazane, hexamethyldisilazane, and pentamethyldisilazane.

Claims (13)

The transmittance (optical path length 1 cm) at a wavelength of 365 nm of a dispersion liquid mixed at a concentration of 10% based on the mass of the dispersion medium composed of methyl ethyl ketone and dispersed for 10 seconds by a shaker is 10% or less,
Transmittance at a wavelength 365nm of dispersed dispersion 10% were mixed at a concentration pressure 180MPa mass of the dispersion medium consisting of methyl ethyl ketone as a reference by a wet jet mill (optical path length 1 cm) and 10% super der is,
By irradiating an ultrasonic wave having an oscillation frequency of 39 kHz and an output of 500 W for 10 minutes to a substance dispersed in methyl ethyl ketone at a concentration of 20% by mass, the silica particle material can be substantially dispersed into primary particles,
Ri Do silica particulate material is a volume average 100nm particle diameter from 1nm of primary particles,
Dry state Der Ru powder or granular material.   A granular material comprising a silica particle material in which at least a part is a secondary particle dispersible to a primary particle by a mechanical load and exhibits fluidity, and the primary particle has a volume average particle diameter of 1 nm to 100 nm.   Instead of determining whether at least a part of the particles can be dispersed to primary particles by a mechanical load, ultrasonic waves are applied to 100 mL of a dispersion liquid in which 10% by mass is dispersed in a dispersion medium composed of MEK based on the total mass. After passing for 5 minutes, 95% or more of the granular material passes when suction filtration is performed with 5 types C filter paper of JISP3801 standard.   The granular material according to any one of claims 1 to 3, wherein the surface is treated with a silane coupling agent and has a silanol group on the surface.   The granular material according to claim 4, which is treated with organosilazane in addition to the silane coupling agent. The mechanical load is any one of the following (i) to (iv): claim 2 or 3, or claim 4 directly or indirectly referring to claim 2 The granular material of any one.
(i) Crushing operation.
(ii) Mixing operation with powder and granule.
(iii) Ultrasonic irradiation in liquid.
(iv) Stirring operation in liquid. The silica particle material has a functional group represented by the formula (1): -OSiX ¹ X ² X ³ and a functional group represented by the formula (2): -OSiY ¹ Y ² Y ³ , and both functional groups are on the surface. The granular material according to any one of claims 1 to 6, comprising silica particles bonded to the particles. (In the above formulas (1) and (2); X ¹ is a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group; X ² , X ³ are each independently selected from -OSiR3 and ^{-OSiY 4 Y 5 Y 6; Y} 1 is an ^{R; Y} 2, Y ³ are each selected from R and -OSiY ⁴ Y ⁵ Y ⁶ independently. Y ⁴ is R; Y ⁵ and Y ⁶ are each independently selected from R and —OSiR 3, and R is independently selected from an alkyl group having 1 to 3 carbon atoms, wherein X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ are each represented by —O— with any one of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ . May be combined.) The silane coupling agent has three alkoxy groups, a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group,
The molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10. 5 or 4 is cited directly or indirectly. The granular material of any one of Claims 5-7. It is a manufacturing method which can manufacture the granular material which consists of a silica particle material given in any 1 paragraph of Claims 1-8,
A surface treatment step of obtaining the silica particle material by surface-treating the raw silica particles so that silanol groups remain on the surface with a silane coupling agent and organosilazane in a liquid medium containing water;
After the surface treatment step, the silica particle material is precipitated with a mineral acid, the precipitate is washed and dried with water, and a solidification step for obtaining a solid body of a powder body made of the silica particle material;
With
The surface treatment step includes
A first treatment step of treating the raw silica particles with the silane coupling agent;
Second processing step and the method of manufacturing a lifting one particulate material and to process the raw material silica particles in the organosilazane. In the second treatment step, a part of the organosilazane is replaced with a second silane coupling agent having three alkoxy groups and an alkyl group having 1 to 3 carbon atoms,
The method for producing a granular material according to claim 9, further comprising a third treatment step of treating the raw silica particles with the organosilazane after the second treatment step.   The silane coupling agent is phenyltrimethoxysilane, vinyltrimethoxysilane, epoxytrimethoxysilane, methacryltrimethoxysilane, aminotrimethoxysilane, ureidotrimethoxysilane, mercaptotrimethoxysilane, isocyanatetrimethoxysilane, or acrylictrimethoxysilane. The method for producing a granular material according to claim 9 or 10, which is at least one selected from methoxysilane.   The method for producing a granular material according to any one of claims 9 to 11, wherein the organosilazane is at least one selected from tetramethyldisilazane, hexamethyldisilazane, and pentamethyldisilazane.   The property modifying material comprising a granular material according to any one of claims 1 to 8, wherein the property modifying material is used by being dispersed in a resin comprising a thermoplastic resin or a thermosetting resin or being mixed with microbeads.