JP3969506B2 - Method for producing glass fiber-containing phenolic resin molding material, and glass fiber-containing phenolic resin molding product - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass fiber-containing phenolic resin molding material having high strength, excellent dimensional stability, and good workability. In particular, molded products obtained by compression molding with good moldability have good appearance, excellent heat resistance, high strength, particularly high impact strength, good dimensional stability, and metal replacement Glass fiber-containing phenolic materials that are useful as molding materials, such as tool change arms in machining centers, valve valves, bolts, gears such as sprockets, and various other structural parts The present invention relates to a resin molding material.
[0002]
[Prior art]
In recent years, from the viewpoint of weight reduction and cost reduction, replacement of metal materials with plastic materials has been attempted, and various plastics have been studied and used in fields such as molded products and structural parts where metals have been used. Is coming.
[0003]
In particular, phenol resin has been studied as a metal substitute material because of its excellent characteristics.
However, even when a phenol resin is used as a substitute for a metal material, improvement in performance such as mechanical strength, heat resistance, dimensional stability, and sliding characteristics is required.
In order to satisfy such requirements, chopped strands of glass fiber or carbon fiber are used as a reinforcing material.
[0004]
By the way, when carbon fiber is used as the reinforcing material, a high-strength molded product having high rigidity can be obtained.
However, carbon fibers are generally expensive. Therefore, the cost is high.
Furthermore, carbon fibers are easier to be defibrated than glass fibers, have poor wettability with phenolic resins, and are difficult to handle.
[0005]
For the above reasons, the use of glass fibers is considered.
Many reports have been made on phenolic resin molding materials containing chopped strands of glass fiber as a reinforcing material.
That is, for example, a phenol resin, glass fiber, and other inorganic additives, a curing agent, a release agent, etc. are mixed as necessary, kneaded with a roll, a kneader, etc. under heating, then dried and pulverized. A glass fiber-containing phenolic resin molding material has been proposed.
Alternatively, a glass fiber-containing phenol resin molding material obtained by mixing and kneading phenol resin, glass fiber, and other inorganic additives, curing agents, mold release agents, etc. with a high-speed stirring mixer such as a Henschel mixer or a super mixer. Proposed.
Recently, phenolic resin, glass fiber, and other inorganic additives, curing agents, mold release agents, etc. are mixed with a high-speed stirring mixer such as a Henschel mixer, and then kneaded and extruded with an extruder. Molding materials have been proposed.
[0006]
[Problems to be solved by the invention]
However, it has been found that the glass fiber-containing phenol resin molding material described above often has broken or cut glass fibers, and the effect of improving the mechanical strength is not as expected.
It has also been found that in order to obtain a material excellent in mechanical strength that can be used as a metal substitute material, the amount of glass fiber must be considerably increased.
However, it has been found that when the amount of glass fiber is increased, materialization is difficult. For example, it takes a long time for materialization. In addition, when it takes material for a long time, the glass fiber is often cut, and a desired strength cannot be obtained. Furthermore, when it molds using the molding material which increased the compounding quantity of the glass fiber, the moldability is bad. Moreover, the surface appearance of the obtained molded product is poor.
[0007]
Therefore, the problem to be solved by the present invention is that it has excellent heat resistance and mechanical strength, is excellent in molding processability, is excellent in appearance of the molded product, and is low in cost. It is to provide a glass fiber-containing phenolic resin molding material. In particular, it is to provide a glass fiber-containing phenolic resin molding material suitable for compression molding.
[0008]
[Means for Solving the Problems]
The above issues are
It contains 20 to 40 parts by weight of phenolic resin and 80 to 60 parts by weight of glass fiber as main components, the average fiber length of the glass fiber is 3.0 to 8.0 mm, and the flexural modulus is 2200 kgf. / in mm ² or more, and a method for producing a glass fiber-containing phenolic resin molding material for flexural strength for forming the 20 kgf / mm ² or more glass fiber-containing phenolic resin molded article,
A first step of rotating and stirring a liquid phenolic resin material in an amount to be a phenolic resin in the glass fiber-containing phenolic resin molded article by a low- speed rotary mixer that is lower than the rotational speed of a high-speed rotary mixer described later. When,
After the first step, a glass fiber having a fiber diameter of 6 to 12 μm, a fiber length of 3.0 to 9.0 mm, and an aspect ratio of 250 to 1500 in the glass fiber- containing phenolic resin molded product. A second step of adding as much as the amount of the glass fiber , mixing and kneading,
After the second step, a low-boiling solvent such as methanol or acetone is added, and the mixture is granulated by stirring and mixing at a temperature of 40 ° C. or less with a high- speed rotary stirring mixer faster than the rotation speed of the first step . 3 steps,
It solves by the manufacturing method of the glass fiber containing phenolic resin molding material characterized by having the 4th process dried after the said 3rd process.
[0009]
In the above production method, the phenolic resin in the low-speed rotating stirring and mixing step is particularly a liquid resin.
Further, the mixing in the low-speed rotary stirring and mixing step is preferably until the mixture changes from clay to scale or flake.
The glass fibers to be added are preferably chopped strands having a fiber diameter of 6 to 12 μm, a fiber length of 3.0 to 9.0 mm, and an aspect ratio of 250 to 1500.
The amount of the low boiling point solvent added in the granulation step is preferably 1 to 3% by weight of the mixed / kneaded product after the glass fiber is added.
[0010]
Moreover, the said subject is solved by the glass fiber containing phenolic resin molding material obtained by the said manufacturing method.
The above-mentioned problem is a glass fiber reinforced phenolic resin molding material containing 20 to 40 parts by weight of a phenolic resin and 80 to 60 parts by weight of glass fiber as main components. The glass fiber in is solved by a glass fiber-containing phenolic resin molding material having an average fiber length of 3.0 to 8.0 mm.
The above-mentioned problem is a glass fiber-containing phenolic resin molded product containing 20 to 40 parts by weight of a phenolic resin and 80 to 60 parts by weight of glass fibers as main components,
The glass fiber in the glass fiber-containing phenolic resin molded product has an average fiber length of 3.0 to 8.0 mm,
Flexural modulus 2,200kgf / mm ² or more and the flexural strength is solved by a glass fiber-containing phenolic resin molded article, characterized in that it is 20 kgf / mm ² or more.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, 20 to 40 parts by weight (80 to 60 parts by weight of glass fibers and 20 to 40 parts by weight of a phenolic resin is 100 parts by weight) of a phenolic resin, a filler, a pigment, and a mold release After the low-speed rotary stirring and mixing step, and the low-speed rotary stirring and mixing step, 60 to 80 parts by weight of glass fiber is added to the mixture after the low-speed rotary stirring and mixing step. Addition, mixing and kneading glass fiber post-mixing and kneading step, and after the glass fiber post-mixing and kneading step, a low boiling point solvent is added and granulated with a high-speed rotary stirring mixer at a temperature of 40 ° C. or less A granulation step, and a drying step of drying after the granulation step. The phenolic resin in the low-speed rotation stirring and mixing step is particularly a liquid resin. Mixing in the low-speed rotary stirring and mixing process is in particular until the mixture changes from clay to flakes or flakes. The added glass fiber is a chopped strand having a fiber diameter of 6 to 12 μm, a fiber length of 3.0 to 9.0 mm, and an aspect ratio of 250 to 1500. The addition amount of the low boiling point solvent in the granulation step is particularly 1 to 3% by weight of the mixed / kneaded product after the glass fiber is added.
[0012]
After mixing the phenolic resin, a predetermined amount of filler and pigment, a release agent, and if necessary a curing agent with a low-speed rotary stirring mixer having a stirring blade, glass fiber is added, and this mixing and kneading is performed. The mixture obtained is dried once and then granulated while maintaining the temperature at 40 ° C. or lower while adding the low boiling point solvent with a high-speed rotary stirring mixer, and thereafter, the mixture is granulated at 85 to 110 ° C. By drying at a temperature, a glass fiber-containing phenolic resin molding material is obtained.
That is, first, after mixing 20 to 40 parts by weight of a phenolic resin, a predetermined amount of a filler and a pigment, a release agent, and a curing agent as necessary, with a low-speed rotary stirring mixer having a stirring blade, After adding 60 to 80 parts by weight of glass fiber, mixing and kneading, the resulting mixture was once dried, and then the mixture was added at 40 ° C. while adding a low boiling point solvent with a high-speed rotary stirring mixer. Granulation is performed while maintaining the following temperature, and thereafter, the glass fiber-containing phenolic resin molding material is obtained by drying at a temperature of 85 to 110 ° C.
[0013]
The glass fiber-containing phenolic resin molding material obtained as described above has good molding processability despite containing a large amount of glass fiber (50% by weight or more in the molding material). In addition, the molded product obtained by compression molding the molding material has an impact strength (Charpy, with notch) of 25 kgf · cm / cm ² or more, a flexural modulus of 2,200 kgf / mm ² or more, and a bending strength. 20 kgf / mm ² or more. And there is almost no mold shrinkage and it is excellent in mechanical strength and dimensional stability. Furthermore, the surface state is good.
[0014]
In the method for producing a molding material of the present invention, mixing and kneading with a low-speed rotary stirring mixer having a stirring blade, for example, a normal open kneader, is performed while maintaining a temperature of 40 ° C. or lower. The mixing time by the low-speed rotary stirring mixer is the time until the mixture changes from clay (paste) to scale or flake, and is usually 20 to 40 minutes. If the mixing time is too long, the desired predetermined physical properties cannot be obtained, which is not preferable.
[0015]
The obtained mixture is dried (primary drying) in a dryer such as a hot air circulating dryer at a temperature of 85 to 110 ° C., particularly around 100 ° C., until a target flow value (spiral flow) is reached. The The time required for this drying is usually around 60 minutes. When the drying temperature is low, the time required for drying becomes long, which is not preferable in terms of work operation. On the other hand, when the drying temperature is too high, it is difficult to perform work operations such as adjustment of the flow value of the material, and variations in drying are likely to occur.
[0016]
Subsequently, the dried scale-like or flake-like mixture is maintained at a temperature of 40 ° C. or lower while adding a low-boiling solvent such as methanol or acetone with a high-speed rotary stirring mixer such as a Henschel mixer or a spar mixer. Stir and granulate. The time required for granulation is within 10 minutes, usually 4 to 6 minutes.
After granulation, it is dried (secondary drying) at a temperature of 85 to 110 ° C., particularly around 100 ° C., in a dryer such as a hot air circulating dryer. This drying mainly volatilizes the remaining solvent. The time required is usually completed in about 40 minutes, and a target flow value (spiral flow) is obtained.
[0017]
The usage-amount of said low boiling-point solvent is 3.0 weight% or less with respect to the weight of the mixture charged to a mixer. Usually, 1.0 to 2.0% by weight is used. When the amount of the solvent used is large, the shape of the granulated product tends to be large. On the other hand, when the amount is small, the so-called granulated product is poor and it is difficult to obtain a good molding material, which is not preferable.
[0018]
In the molding material of the present invention, the phenolic resin is used in the range of 20 to 40% by weight in the entire formulation. When the blending ratio of the phenolic resin is less than the above range, the kneading operation cannot be performed satisfactorily. And dispersion | distribution of resin is inadequate, materialization is difficult and a favorable molding material cannot be obtained. On the contrary, when the ratio of the resin is large, sufficient mechanical strength cannot be obtained. Accordingly, the proportion of the phenolic resin used is preferably within the above range. Particularly preferred is 25 to 35% by weight.
[0019]
In the present invention, the phenolic resin is used as a liquid resin having a resin concentration of 65 to 75%. When a solid resin is used, it is used after adjusting to a predetermined resin concentration with a solvent such as methanol or acetone.
[0020]
In the present invention, as described above, the charging order in the low-speed rotary stirring mixer is first to mix the phenolic resin with a predetermined amount of filler, pigment, release agent, and if necessary, a curing agent. Thereafter, glass fiber is added thereto. It is important to mix and knead.
When glass fibers are charged together with a resin from the beginning and mixed, the glass fibers are easily cut, and the target predetermined performance (physical properties) cannot be obtained.
[0021]
In the present invention, in order to obtain a molded article having high impact strength, high rigidity and high elasticity as described above, the glass fiber is prevented from being broken and cut as much as possible, and the average fiber length of the glass fiber in the molding material is 3 It is important that the thickness is in the range of 0.0 to 8.0 mm. When the fiber length is shorter than the above range, it is difficult to obtain a molded product having high rigidity and high elasticity. On the other hand, if the length is long, the moldability is poor, it is difficult to obtain a stable molded product, and the surface condition of the molded product is poor.
[0022]
The glass fiber used in the present invention is a chopped strand having a fiber diameter of 6 to 12 μm, a fiber length of 3.0 to 9.0 mm, and an aspect ratio of 250 to 1500. Preferably, it is treated with a silane compound.
[0023]
A commercially available glass fiber is used for the glass fiber used in the present invention. Examples thereof include ECS06B155, ECS03B163DE (manufactured by Nippon Electric Glass Co., Ltd.), CS06JABC-273, CS03DEBC-27 (manufactured by Asahi Fiber Glass Co., Ltd.) and the like.
[0024]
The compounding quantity of glass fiber is 60 to 80 weight% in all the compounds. Preferably, it is 65 to 75% by weight. When the blending amount of the glass fiber is less than the above range, a molded product excellent in mechanical properties such as strength, rigidity and elastic modulus cannot be obtained. On the other hand, when the amount is large, molding processability, fluidity and the like deteriorate, and the surface state of the molded article also deteriorates.
[0025]
The phenolic resin in the present invention is an aromatic compound having a phenolic hydroxyl group. Specifically, a condensation reaction of phenolic compounds such as phenol, cresol, xylenol, alkylphenol, resorcinol and aldehydes such as formaldehyde, acetaldehyde, paraformaldehyde, furfural, and cyclic formal in the presence of an acidic catalyst or an alkaline catalyst. Synthetic resins obtained or modified resins of these resins, as well as other thermosetting resins such as epoxy resins, amino resins and other co-condensation reactions, and some thermoplastic resins or others And polymer alloys with these resins. Usually, so-called phenolic resins are used.
[0026]
In the present invention, the phenolic resin may be a resol type, novolac type solid or liquid. In addition, when mix | blending with glass fiber, it is usually suitable to use in liquid form. When kneaded with glass fiber in a solid state, the glass fiber is greatly broken, and the adhesion between the resin and the glass fiber is also deteriorated.
[0027]
If desired, the molding material according to the present invention may further contain a small amount of inorganic filler such as clay, talc, mica, etc. (about 5 to 10% by weight in the total formulation). In addition, various additives blended in the phenolic resin molding material can be used as long as the characteristics of the molding material according to the present invention are not impaired.
[0028]
The phenolic resin molding material obtained by the method of the present invention contains 20 to 40 parts by weight of phenolic resin and 80 to 60 parts by weight of glass fibers as main components, and the average fiber length of the glass fibers in the molding material is 3. It is a glass fiber-containing flaky phenolic resin molding material present at 0.0 to 8.0 mm. Then, by molding the molding material under predetermined conditions, a molded product having high strength, high rigidity, excellent dimensional stability, and heat resistance can be obtained.
Specific examples of the present invention will be described below.
[0029]
[Example 1]
As the phenolic resin, a liquid resin (resin concentration: 70% by weight) in which a novolak type phenol resin having a number average molecular weight of 1200 was dissolved in 30% methanol was used.
ECS06B155 (trade name) chopped strand (fiber length 6 mm, fiber diameter 13 μm) was used as the glass fiber.
First, 30 parts by weight of the phenolic resin (including solid content and 4.5 parts by weight of hexamine) and a total of 5 parts by weight of a curing aid, a pigment, and a release agent were charged in a kneader and mixed in advance.
After this time, 65 parts by weight of glass fibers were added to the mixture and mixed at 30 ° C. for about 30 minutes.
This mixture was dried with a hot air dryer at 95 ° C. for 60 minutes.
Next, the dried mixture was granulated with a high-speed rotary stirring mixer (Henschel mixer) while maintaining the temperature at 40 ° C. or lower while adding 2 parts by weight of methanol.
This granulated product was dried with a hot air dryer at 95 ° C. for 40 minutes to obtain a flaky molding material.
Table 1 shows the physical properties of the obtained molding material and molded product.
[0030]
[Example 2]
CS06JABC-273 (manufactured by Asahi Fiber Glass) chopped strand (fiber length 6 mm, fiber diameter 13 μm) and ECS03B155 (manufactured by Nippon Electric Glass Co., Ltd.) chopped strand (fiber length 3 mm, fiber diameter 13 μm) were used as glass fibers. Except for the above, a flaky molding material was obtained in the same manner as in Example 1.
Table 1 shows the physical properties of the obtained molding material and molded product.
[0031]
[Example 3]
As phenolic resin, 25 parts by weight (as solid content) of a liquid resin obtained by diluting a solid resol type phenolic resin having a number average molecular weight of 500 to 30% methanol is used, and ECS06B155 chopped strand (fiber length 6 mm, fiber diameter) as glass fiber. 70 parts by weight of 13 μm) was used.
And it mixed like Example 1.
The obtained mixture was dried in the same manner as in Example 1, and granulated while adding 3 parts by weight of methanol to the mixture using a Henschel mixer.
Then, it dried at 90 degreeC and was set as the flaky molding material.
Table 1 shows the physical properties of the obtained molding material and molded product.
[0032]
[Example 4]
A liquid resin obtained by diluting 50% xylene-modified phenol resin to 30% methanol is used as the phenolic resin, and ECS03B163DE chopped strand (fiber length 3 mm, fiber diameter 6 μm) and CS06JABC-273 chopped strand (fiber length) are used as glass fibers. 6 mm, fiber diameter 13 μm) was used.
First, 25 parts by weight of the phenolic resin (including solid content and 3.7 parts by weight of hexamine) and a total of 5 parts by weight of the pigment and the release agent were charged in a kneader and mixed in advance.
Thereafter, 70 parts by weight of glass fiber was added and mixed at 30 ° C. for about 30 minutes. Thereafter, the mixture was dried with a hot air dryer at 95 ° C. for 60 minutes.
Next, the dried mixture was granulated with a high-speed rotary stirring mixer (Henschel mixer) while maintaining a temperature of 25 ° C. while adding 3 parts by weight of methanol.
This granulated product was dried with a hot air dryer at 95 ° C. for 40 minutes to obtain a flaky molding material.
Table 1 shows the physical properties of the obtained molding material and molded product.
[0033]
[Comparative Example 1]
In Example 1, it carried out similarly to Example 1 except having used 15 weight part (it contains 2.5 weight part of hexamine) phenolic resin, and using 85 weight part of glass fiber.
However, this material was insufficiently impregnated with resin, so that a good flaky product could not be obtained, the flow value was small, the moldability was poor, and a good molded product could not be molded.
[0034]
[Comparative Example 2]
Using the same amount of the phenolic resin, glass fiber, and additive used in Example 1, all of the raw materials were mixed at once, and this mixture was thoroughly kneaded with a heating roll for about 5 minutes, dried and pulverized, and molded. Material was used.
Table 2 shows the physical properties of the obtained molding material and molded product.
[0035]
[0036]
[0037]
The physical properties in Tables 1 and 2 were measured as follows.
(1) Flow (cm): Spiral low method, using a die engraved with a length (100 cm) in a spiral shape, and tophan-spher molding at a predetermined temperature, pressure, time and material input amount, and extruded. The maximum length of a spiral product.
(2) Average fiber length (mm): The resin content in the molding material is extracted and removed with a solvent, and the remaining glass fiber is observed and measured with an electron microscope.
(3) Formability: The moldability of the molded product compression-molded according to JIS K6915 and the appearance were visually observed and judged.
(4) Specific gravity (g / cm ³ ): According to JIS method.
(5) Impact strength, bending strength, flexural modulus: A test piece was prepared by compression molding and measured according to JIS K6915.
(6) Mold shrinkage (%): A test piece was prepared by compression molding and measured according to JIS K6915.
(7) Smoothness: The surface of the molded product molded by compression molding was determined by visual observation.
[0038]
【The invention's effect】
The molding material of the present invention has good moldability. A molded product obtained by compression molding the molding material is excellent in mechanical strength such as impact strength, bending strength, and flexural modulus. In addition, the molding shrinkage is extremely small.

Claims (3)

It contains 20 to 40 parts by weight of phenolic resin and 80 to 60 parts by weight of glass fiber as main components, the average fiber length of the glass fiber is 3.0 to 8.0 mm, and the flexural modulus is 2200 kgf. / in mm ² or more, and a method for producing a glass fiber-containing phenolic resin molding material for flexural strength for forming the 20 kgf / mm ² or more glass fiber-containing phenolic resin molded article,
A first step of rotating and stirring a liquid phenolic resin material in an amount to be a phenolic resin in the glass fiber-containing phenolic resin molded article by a low-speed rotary mixer that is lower than the rotational speed of a high-speed rotary mixer described later. When,
After the first step, a glass fiber having a fiber diameter of 6 to 12 μm, a fiber length of 3.0 to 9.0 mm, and an aspect ratio of 250 to 1500 in the glass fiber-containing phenolic resin molded product. A second step of adding as much as the amount of the glass fiber, mixing and kneading,
After the second step, a low boiling point solvent selected from the group of methanol and acetone is added, and the mixture is stirred and mixed at a temperature of 40 ° C. or less with a high-speed rotary stirring mixer faster than the rotation speed of the first step. A third step of granulation;
A method for producing a glass fiber-containing phenolic resin molding material, comprising a fourth step of drying after the third step.   The method for producing a glass fiber-containing phenolic resin molding material according to claim 1, wherein the mixing and kneading in the second step is until the mixed and kneaded product changes from clay to scaly or flakes.   The addition amount of the low boiling point solvent in the third step is that of the mixed and kneaded product after adding the glass fiber having a fiber diameter of 6 to 12 μm, a fiber length of 3.0 to 9.0 mm, and an aspect ratio of 250 to 1500. It is 1 to 3 weight%, The manufacturing method of the glass fiber containing phenolic resin molding material of Claim 1 characterized by the above-mentioned.