JP4402926B2 - Glass chopped strand and method for producing the same - Google Patents

Description

  The present invention relates to a glass chopped strand (hereinafter abbreviated as “CS”) used for reinforcing thermoplastic resins, thermosetting resins, and the like, and a method for producing the same.

  CS obtained by cutting a glass fiber (glass filament) bundle into a predetermined length is mixed with a matrix resin such as a thermoplastic resin or a thermosetting resin, and used for the production of a fiber reinforced resin. It is known as a reinforcing material (reinforcing material) that improves physical properties such as strength, heat distortion temperature, and elastic modulus of a molded product.

  As a manufacturing process of the fiber reinforced resin and the molded product, the blending ratio of CS, resin, and other additives is kept constant, and the above components are supplied into an extruder by an automatic feeder to obtain a uniform mixture. A method is used in which a desired molded article is produced from a mixture by a molding machine, or a molded article is produced by simultaneously supplying CS, resin and other additives directly into a molding machine.

  In the manufacturing process of a mixture or a molded product as described above, conveying means such as automatic weighing and pneumatic transportation are used for conveying CS, and during such handling, CS becomes fuzzy or yarn (strand) breaks. There is a problem that workability and yield of CS are reduced due to splitting and the like, and the mechanical strength of the finally obtained molded product is reduced due to the fluff of these CSs.

  Therefore, CS in which the above-described problems are solved, that is, CS with strong glass filament focusing is desired. As a method for obtaining a CS having strong converging property of a glass filament, for example, as described in Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4, a vibrating action is applied to CS in a wet state to which a bundling agent is applied. It has been proposed to make the glass filaments constituting the CS closer by attaching the symbol.

  However, on the other hand, if the converging property of the glass filament constituting the CS is too strong, the CS does not open properly in the molded product obtained by molding the mixture of CS and resin, and the glass in the resin Filament dispersion tends to be insufficient. Furthermore, in the method described in the above-mentioned patent document, as the focusing of the CS glass filaments becomes closer, the CS particles are aggregated and enlarged, which is accompanied by a so-called granulation action. Is insufficiently distributed. In other words, if the glass filaments are not sufficiently dispersed in the resin and the glass filaments are present as a bundle, there is a problem that the surface appearance and mechanical strength of the final product such as a molded product are significantly impaired. It was.

  Moreover, in the said patent document 4, after spraying water or a process liquid on the strand which consists of 100-1,000 glass filaments, by cutting | disconnecting to predetermined length and giving a rolling vibration action with a spiral vibration trough, The outer surface of the end surface of the strand can be formed of a substantially cylindrical body or a substantially elliptical cylinder in a plane substantially perpendicular to the longitudinal axis direction. In this patent document 4, particles having a mesh size of 4,000 μm or more are 3% by mass or less and particles having a mesh size of 425 μm or less are 3% by mass or less. A characteristic CS manufacturing method is described.

  Further, in the invention described in Patent Document 4, although it is possible to make the particle size of CS uniform, the above-mentioned granulation is inevitable, and a molded product formed using the granulated CS is The dispersibility of the glass filament was inferior. Moreover, even if it granulates by reducing the converging number of the glass filaments described in the said patent document 4 like 100-500, for example, and giving rolling vibration action to wet CS. It is possible to obtain CS with small overall particles. Although it is thought that the dispersibility of the glass filament in the molded product using CS obtained by this method is improved, producing a glass strand with a small number of bundles is extremely inferior in CS productivity, and the CS obtained thereby. Is very expensive and economically inferior.

Japanese Patent Publication No.1-24900 JP-A-8-91865 Special table 2002-513448 gazette JP 2001-233630 A

  The present invention has been made in view of the above problems, and its purpose is excellent in economic efficiency, less occurrence of yarn cracking and fluff during handling during transportation, and excellent dispersibility of glass filaments in the resin. CS and its manufacturing method are provided.

The above object is achieved by the present invention described below. That is, in the present invention, as a first invention, a sizing agent comprising a silane coupling agent aqueous solution and a water-dispersed resin is added to 1,000 or more glass filaments in a solid content of 0.1 to 2 mass of the glass filament. %, And the strands are bundled and bundled to form a strand. The strand is then cut into a predetermined length, and the strand is then subjected to a rolling vibration action within a range of 5 to 11% by mass of its moisture content. A method for producing CS which is dried after being given,
The water-dispersed resin mainly contains an epoxy resin emulsion and a urethane resin emulsion having an average particle diameter of 0.5 to 2.0 μm, and a solid content mass ratio of the epoxy resin emulsion to the urethane resin emulsion is 20 to 80. : a 80 to 20, the resin content of the urethane resin Emarujo in emissions is to provide a method for producing CS, characterized in that is contains at least 20% by weight, based on the total solid content of the sizing agent.

Moreover, this invention is a sizing agent which consists of silane coupling agent aqueous solution and water dispersion resin as 2nd invention, Comprising: The said water dispersion resin is an epoxy resin emulsion, and an average particle diameter is 0.5-2. Mainly containing 0 μm urethane resin emulsion, the solid content mass ratio of the epoxy resin emulsion and the urethane resin emulsion is 20 to 80:80 to 20, and the resin content in the urethane resin emulsion is that of the sizing agent. In a glass chopped strand provided with a sizing agent contained at 20% by mass or more based on the total solid content,
In the method for measuring the particle size distribution of CS, which will be described in detail later, the CS of 2,000 μm or more is 1% by mass or less of the total amount of CS, and the bulk specific gravity of spontaneous fall is 0.5 to 0.75 (g / ml).

  According to said 1st invention, productivity of CS can be improved by using the glass strand which bundled 1,000 or more glass filaments. Furthermore, the present inventors usually give a rolling vibration to wet CS by applying a sizing agent, and when CS is granulated, the average particle diameter is 0.5 μm or more, preferably 0.5-2. By using a sizing agent containing a specific amount of a resin emulsion containing 5 μm resin particles, and further imparting a vibrating action to CS at a moisture content of 5 to 11% by mass, without excessively granulating the resulting CS, Moreover, it has been found that the glass filament bundle can be made dense by improving the focusing force of the glass strands.

  This reduces the excessive spreadability of the resulting CS, reduces the occurrence of CS fluff during handling, and the CS particle size is not large when kneading CS into the matrix resin. The fiber is easily opened and the dispersibility of the glass filament in the molded product is improved.

  According to the second invention, in the method for measuring the particle size distribution of CS described later, CS of 2,000 μm or more is 1% by mass or less of the total amount of CS, and the bulk specific gravity of natural fall is 0.00. By being 5 to 0.9 (g / ml), the excessive opening property of CS is reduced, the generation of fluff is reduced, and the particle diameter is not large when kneaded into the matrix resin. CS is easily opened in the matrix resin, and the dispersibility of the glass filament in the molded product is improved.

Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention.
In the present invention, various kinds of glass usually used for producing CS can be used as the glass raw material of the glass filament, but it is particularly preferable to use E glass which can be easily formed into a glass filament and can obtain good characteristics. preferable.

  The glass filament sizing agent used in the present invention comprises a silane coupling agent and a water-dispersed resin, and the water-dispersed resin may be an emulsion, a dispersion and / or a water-soluble resin. It must contain a resin emulsion.

  Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, vinyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane. Is preferred. These silane coupling agents are used alone or in combination of two or more, dissolved in water.

  It is preferable that 1-50 mass% of said silane coupling agents are contained with respect to the total amount of solid content of the sizing agent. When the content is less than 1% by mass, the converging property of the glass filament and the strength of the molded product when using CS as the fiber reinforced thermoplastic resin (FRTP) are inferior, and the content exceeds 50% by mass. And the opening of CS and the color tone of the molded product when FRTP is used are not preferable.

  It is important that the sizing agent used in the present invention contains at least a resin emulsion containing resin particles having an average particle diameter of 0.5 μm or more. When the resin emulsion containing resin particles having an average particle size of 0.5 μm or more is not included in the sizing agent, appropriate opening of CS becomes insufficient in the steps after the glass strand cutting step, and the particle size in CS Not only the particles of 2,000 μm or more do not become 1% by mass or less, but also when rolling vibration is applied to wet CS, granulation of CS occurs and CS particles become larger, which is not preferable. The agent may also contain particles other than the resin particles (for example, resin particles having a particle diameter of less than 0.5 μm, water-insoluble particles other than resin particles, micelles formed by a surfactant, etc.), The average particle diameter of all the particles is preferably in the range of 0.3 to 2.0 μm.

  When the average particle diameter of all the particles is less than 0.3 μm, the above effect of adding the resin emulsion containing the resin particles of 0.5 μm or more is not exhibited, and the upper limit of the average particle diameter is 2.0 μm. This is because when the average particle diameter exceeds 2.0 μm, uneven adherence of the sizing agent to the glass filament is likely to occur, and when the strand is cut too much, the cracking property of the glass filament is extremely poor. When CS is kneaded with a matrix resin, the interfacial adhesion is partially inferior between the glass filament and the matrix resin, and the mechanical strength of the resulting molded product may be lowered.

  In the present invention, the average particle diameter of all the particles in the sizing agent and the resin emulsion is not particularly limited as long as it is a method of measuring with a dynamic light scattering photometer to obtain the number average particle diameter value. As a preferred specific example, the resin emulsion and the sizing agent are diluted with distilled water to a measurable concentration, filled in a four-surface transmission type 10 mm square cell, and irradiated with a He-Ne laser at 25 ° C. for measurement. The number average particle diameter value is defined as “average particle diameter”.

  The type of the resin in the resin emulsion used in the present invention is not particularly limited, and one or a combination of two or more resins having a film-forming ability is used by being dispersed in water. For example, emulsions such as urethane resin, epoxy resin, acrylic resin, vinyl acetate resin, polyester resin, polyolefin resin and the like can be mentioned.

  As the resin emulsion, an epoxy resin emulsion and a urethane resin emulsion are preferably used in combination. In this case, the mass ratio of the solid content of the epoxy resin emulsion and the urethane resin emulsion is 20 to 80:80 to 20, and the average particle diameter of the resin particles of the urethane resin emulsion is 0.5 to 2.0 μm. It is preferable that the appropriate opening of CS proceeds in the kneading step with the matrix resin. When the average particle size is less than 0.5 μm, the appropriate opening of CS does not proceed in the kneading process with the matrix resin, and when the average particle size exceeds 2.0 μm, yarn cracking at the time of strand cutting proceeds. Thus, the converging property of the glass filament may be extremely inferior.

  The sizing agent in the present invention is preferably attached in an amount of 0.1 to 2% by mass as a solid content with respect to the total amount of the glass filament containing the sizing agent, and is further attached in an amount of 0.2 to 1.5% by mass. More preferably. If the adhesion amount is less than 0.1% by mass, there is a problem that CS yarn breakage and fluff are likely to occur. If the adhesion amount exceeds 2% by mass, the CS particles are agglomerated due to rolling vibration. Therefore, when CS is kneaded with resin, there is a problem that undispersion of the glass filament is likely to occur.

  Next, the manufacturing method of CS of this invention is demonstrated. First, the glass melt | dissolved is pulled out from a bushing etc. and a glass filament is obtained. At that time, the larger the number of bundles of glass filaments, so-called strands, the better the CS productivity (economic), so the number of bundles of glass filaments per strand is 1,000 or more. Preferably, it is 1,500 or more and 5,000 or less. When the number of glass filaments is less than 1,000, as described above, it is inferior in economic efficiency during CS production. In addition, when the number of glass filaments converging exceeds 5,000, a CS having very large particles as a whole is produced. Therefore, when kneaded into a resin, the CS openability in the resin is poor. It is not preferable.

  The glass filaments thus drawn out are treated by attaching a sizing agent in an amount of 0.1 to 2% by mass as a solid content, and are then drawn to focus the glass filaments. As a method of attaching the sizing agent to the glass filament, any method such as a spray method or a roll coater method may be used, but a roll coater method of attaching via a roll called an applicator is economical and preferably employed. In addition, when providing a sizing agent, the moisture content of the strand (wet CS) to which the sizing agent is attached is adjusted to 5 to 11% by mass. The moisture content is adjusted by adjusting the number of rotations of the applicator roll and the solid content concentration of the sizing agent when a sizing agent is applied to the strand by a roll coater method to obtain a wet strand having a desired moisture content. Can do.

  The strand thus obtained is cut to a desired length. As a form of the strand, either method may be used, in which the strand is once wound up to be cake-like and then released and cut or cut without being wound. The cutting method is not particularly limited. For example, the cutting is performed with a strand sandwiched between a feed roller made of an elastic body such as rubber or synthetic resin and a cutter roller having a large number of blades radially arranged. A method is preferably employed. Moreover, although the cutting length of a strand is not specifically limited, Usually, 1.5-13 mm is preferable.

  Furthermore, rolling vibration is given to the cut strand at a moisture content of 5 to 11% by mass. The rolling vibration action is provided by one or a combination of two or more devices selected from a rotating drum, a vibration trough, a spiral vibration trough, a modified disk pelletizer, a plow mixer and a ribbon mixer. For example, after rotating by rotating the drum for 5 to 60 seconds, the vibrating trough is held and vibrated for 5 to 90 seconds. During this time, CS is also helped by the influence of the sizing agent, and is subjected to dynamic stimulation, so that a glass strand having a large particle diameter of 1,000 or more is appropriately opened to reduce the particle diameter of the strand. However, the glass filaments are strongly connected to each other, the glass filaments are closely focused, and a round bar CS having a circular cross section with a uniform particle diameter can be obtained.

  This is because the particle size of the obtained CS is increased by using a sizing agent containing a specific amount of a resin emulsion having a specific average particle size, and further giving a rolling vibration action at a moisture content of 5 to 11% by mass of the wet CS. Without reducing the number of glass filaments in the glass strand, while the opened glass strands are left as they are or when the opened glass filaments are gathered again, the strands do not become large grains. It is thought that the glass filament inside is closely focused to form an elongated cylindrical shape.

  In addition, when a rolling vibration action is given to CS, if the moisture content of wet CS is less than 5% by mass, the strands are remarkably advanced, resulting in a CS product with poor convergence, while the moisture content is 11% by mass. If it exceeds 1, not less than 2,000 μm of grains will not become 1 mass% or less of the total CS, but the grains of CS may become larger.

  Since the CS rolls and vibrates for a long time, the CS tends to be granulated. Therefore, in the method of measuring the particle size distribution of CS, particles of 2,000 μm or more should be 1% by mass or less of the total CS. It is preferable to set the time appropriately. Thereafter, the strand subjected to rolling vibration is dried. The wet CS can be dried by a conventional method, for example, a method in which the wet CS is deposited on a conveyor and passed through a tunnel type hot air dryer. In the CS thus obtained, particles of 2,000 μm or more are 1% by mass or less of the entire CS, it is possible to reduce the occurrence of fluff during transportation, and the bulk specific gravity of natural fall is 0.5 to By setting it to 0.9 (g / ml), it becomes possible to reduce the occurrence of CS fluff during transportation. By using CS having this particle size, the particle size is not large when kneaded into the matrix resin, so that the CS is easily opened and the dispersibility of the glass filament in the molded product is improved.

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the text, “part” or “%” is based on mass.
Example 1
A bundle of 1,600 E glass filaments having a fiber diameter of 10 μm is drawn from the bushing, and then 0.5 part of γ-aminopropyltriethoxysilane, an epoxy resin emulsion, and a urethane resin emulsion are added in a solid content of 4.5 parts and 1 part, respectively. A sizing agent containing .5 parts was deposited as a solid content in an amount of 0.9% of the mass of the glass filament, and then the sizing agent was gathered together and squeezed into a drum to make a cake. The average particle size of the resin particles in the emulsion used was 0.4 μm for the epoxy resin emulsion and 0.8 μm for the urethane resin emulsion. Next, strands are pulled out from the 40 cakes, cut into a length of 3 mm, subjected to a rotating action with a rotating drum, dropped on a diaphragm, a vibration width of 2.5 mm, a vibration frequency of 1,700 cpm, a residence time of 15 A rolling vibration effect was applied under the condition of seconds, and a round bar having a circular cross section with a uniform particle diameter was obtained while a strand having a large particle diameter was appropriately opened. The moisture content of the strand in this state was 9.1%. Then, it dried with a 170 degreeC hot air dryer, and obtained CS of this invention.

Comparative Example 1
In the same glass filament as in Example 1, 0.5 part of γ-aminopropyltriethoxysilane, an epoxy resin emulsion containing resin particles having an average particle diameter of 0.4 μm, and resin particles having an average particle diameter of 0.8 μm are included. A bundling agent containing 4.5 parts and 1.5 parts of solid content of urethane resin emulsion, respectively, is adhered as solid content in an amount of 0.9% of the mass of the glass filament, and then bundled and focused. Then, it was beaten on a drum to make a cake. Next, the strands were pulled out from the 40 pieces of cake, cut into a length of 3 mm, and then immediately dried with a hot air dryer at 170 ° C. to obtain a comparative CS. The moisture content of the strand immediately after cutting was 9.1%.

Comparative Example 2
Urethane resin containing epoxy resin emulsion containing 0.5 parts of γ-aminopropyltriethoxysilane and resin particles having an average particle diameter of 0.4 μm and resin particles having an average particle diameter of 0.2 μm on the same glass filament as in Example 1. After the sizing agent containing 4.5 parts and 1.5 parts in solid content of the emulsion as a solid content is attached in an amount of 0.9% of the mass of the glass filament, they are gathered together and focused. The cake was struck on a drum. Next, strands are pulled out from the 40 cakes, cut into a length of 3 mm, subjected to a rotating action with a rotating drum, dropped on a diaphragm, a vibration width of 2.5 mm, a vibration frequency of 1,700 cpm, a residence time of 15 Rolling vibration was applied under the condition of seconds. The moisture content of the wet CS in this state was 11.2%. Then, it dried with a 170 degreeC hot air dryer, and obtained CS of the comparative example.

The CS of Example 1 and Comparative Examples 1 and 2 were measured for blend value, particle size distribution, dispersibility of the glass filament in the matrix resin, and bulk specific gravity of natural fall. Each measurement was performed as follows. These results are shown in Table 1.
"Measurement method of average particle size of all particles in sizing agent and resin particles in resin emulsion"
Measurement was performed by a dynamic light scattering photometer (Otsuka Electronic LPA System) as follows. That is, after diluting the resin emulsion and the sizing agent with distilled water to a measurable concentration, each is filled into a four-sided transmission type 10 mm square cell, irradiated with a He—Ne laser at 25 ° C., and the number average particle diameter is measured. The value was determined.
"Measurement method of blend value (g)"
3 kg of CS is put into a V mixer having a capacity of 10 liters with a middle blade installed therein, and stirred for 15 minutes at a mixer rotation speed of 30 rpm and a middle blade rotation speed of 480 rpm (in the opposite direction to the rotation of the mixer). Thereafter, the mixture is sieved with a sieve having an opening of 3.35 mm, and the fluff balls remaining on the sieve are collected, and the fluff balls are weighed to 0.1 g to obtain a blend value.

“Measuring method of the ratio (%) of particles with an opening of 2,000 μm or more”
From the top, shake 20g of CS for 20 seconds with sieves with openings of 2,000, 850, 600, 425, 250, and 150μm, and the ratio of CS remaining on the sieve with openings of 2,000μm in%. Calculate the ratio of particles having an opening of 2,000 μm or more (%).
"Measurement method of CS undispersed number"
20 parts of CS is added to and mixed with 80 parts of PBT (polybutylene terephthalate) resin pellets and extruded with a T-die while heating and mixing at a cylinder temperature of 300 ° C. and screw rotation of 100 rpm using a Laboplast mill manufactured by Toyo Seiki, 15 cm wide and 2 mm thick A sheet of was prepared. The number of undispersed CS per 10 cm width and 100 cm length of the produced sheet was visually measured and used as an index of dispersibility.
"Measurement method of bulk specific gravity of natural fall"
180 g of the sample was put into a 1,000 ml graduated cylinder at once, the volume at that time was read, and the value obtained by dividing the volume by mass (180 g) was taken as the bulk specific gravity of natural fall.

  From the results of Table 1 above, it can be seen that the CS of Example 1 has a small blend value and large particle size ratio, and is excellent in workability and dispersibility of the glass filament in the resin. On the other hand, Comparative Examples 1 and 2 have the same workability as Example 1, but the ratio of the large particle diameter is large and the dispersibility of the glass filament in the resin is poor.

Examples 2-6
Solid content (part) (A / B) of epoxy resin emulsion (A) having an average particle size of 0.4 μm and urethane resin emulsion (B) having an average particle size of 0.8 μm in Example 1, the amount of sizing agent attached, The average particle diameter (μm) of all the particles in the sizing agent and the moisture content of the strand were changed as shown in Table 2 below, and the CS of the present invention was obtained in the same manner as in Example 1. When these examples were evaluated in the same manner as described above, the same good results (Table 2) as in Example 1 were obtained.

INDUSTRIAL APPLICABILITY The present invention can provide a CS that is excellent in economic efficiency, has less yarn cracking and fluff generation during handling during transportation, and is excellent in dispersibility of glass filaments in a resin.

Claims (3)

A sizing agent comprising a silane coupling agent aqueous solution and a water-dispersed resin is attached to 1,000 or more glass filaments in a quantity of 0.1 to 2% by mass of the glass filament as a solid content, and aligned. Production of glass chopped strands that are bundled into strands, then cut into a predetermined length, and then the strands are subjected to rolling vibration in the range of 5 to 11% by weight of moisture content and then dried. A method,
The water-dispersed resin mainly contains an epoxy resin emulsion and a urethane resin emulsion having an average particle diameter of 0.5 to 2.0 μm, and a solid content mass ratio of the epoxy resin emulsion to the urethane resin emulsion is 20 to 80. : The method of producing glass chopped strands, wherein the resin content in the urethane resin emulsion is 20 to 20% by mass or more based on the total solid content of the sizing agent.   The method for producing a glass chopped strand according to claim 1, wherein an average particle diameter of all particles in the sizing agent is in a range of 0.3 to 2.0 μm. A sizing agent comprising a silane coupling agent aqueous solution and a water-dispersed resin, wherein the water-dispersed resin mainly comprises an epoxy resin emulsion and a urethane resin emulsion having an average particle size of 0.5 to 2.0 μm, The solid content mass ratio between the epoxy resin emulsion and the urethane resin emulsion is 20-80: 80-20, and the resin content in the urethane resin emulsion is 20% by mass or more based on the total solid content of the sizing agent. In a glass chopped strand to which a sizing agent is applied,
20 g of glass chopped strands were placed on a sieve having a mesh opening of 2,000 μm, shaken for 20 seconds, and the ratio of the glass chopped strands remaining on the sieve was calculated as a percentage of 1% by mass or less, and A glass chopped strand characterized by a bulk specific gravity of natural fall of 0.5 to 0.75 (g / ml).