JPH0967448A - Material composition for formed material of fiber reinforced resin and production of formed material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of maintaining the specific gravity of a formed product low, excellent in impact resistance, preventing wavy stripes and a color irregularity and useful for an artificial marble, etc., by blending specific amounts of a specific filler and cut pieces of a glass fiber strand with a synthetic resin. SOLUTION: This material composition for the formed material of a fiber reinforced resin, is obtained by blending (B) 50-200 pts.wt. of an inorganic salt as a filler and (C) 20-30 pts.wt. cut pieces of a glass fiber strand bound with a binder of which solubility to a reactive diluent contained in a component (A) is 20-60wt.%, based on (A) 100 pts.wt. synthetic resin (e.g. an unsaturated polyester resin blended with the reactive diluent as a resin viscosity adjusting agent).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforced resin containing a synthetic resin, a filler, and cut pieces of glass fiber strands as raw materials for producing a fiber reinforced resin molded product used in, for example, a bathtub. The present invention relates to a material composition for a molded body, and a method for producing a fiber-reinforced resin molded body in which a compound such as a synthetic resin, a filler and a cut piece of glass fiber strand is kneaded and then molded.

[0002]

2. Description of the Related Art Conventionally, for manufacturing a fiber reinforced resin molding such as artificial marble, 200 to 300 parts by weight of a filler and 1 to 3 mm of a glass fiber strand are added to 100 parts by weight of a synthetic resin. 10 to 20 pieces cut into pieces
Parts by weight, and for the purpose of further improving the cohesive force of the kneaded product, a composition in which 60 to 80% by weight of glass powder having a particle diameter of about 10 to 100 μm is compounded with respect to the total amount of the above compound, Using a horizontal kneader, a vertical planetary mixer, etc., after sufficiently kneading the glass fibers before blending them, blending the glass fibers, and kneading for about 10 minutes or more to produce a fiber-reinforced resin molding Was there.

[0003]

However, when the above-mentioned conventional material composition for a fiber-reinforced resin molded product is used, the viscosity of the kneaded product is 10 ⁴ Pa · s or more, and the matrix of the kneaded product is used. Although cohesive force is maintained, it has almost no fluidity and poor moldability. Therefore, there is a limit to the blending amount of reinforcing fibers, and the reinforcing fibers are easily defibrated by kneading. Due to the glass powder added to improve the cohesive strength of the product, the produced fiber-reinforced resin molded product (hereinafter, simply referred to as a product) has a high specific gravity, which causes a problem of a heavy product. Further, glass powder is an expensive material, and there is a problem that the manufacturing cost of the product is increased. In addition, when the reactive diluent is added to the unsaturated polyester resin as a resin viscosity modifier, the dissolution rate of the conventional binder of the glass fiber strand in the styrene monomer that is the solvent of the conventional polyester is It was found that it was high, reaching 80%. In order to solve the problem of the specific gravity, if powders of inorganic salts (for example, calcium carbonate, aluminum hydroxide, barium sulfate) are used as the filler instead of the glass powder, the specific gravity of BMC can be lowered, The matrix cohesive force of the kneaded product is reduced, and the impact strength of the product is also reduced accordingly.If the compounding amount of glass fiber is increased to compensate for this, defects such as wavy stripes and color unevenness appear on the surface of the product. A new problem arises. As a result of continuing intensive research into this cause, the above-mentioned new knowledge was obtained, and further, the defibration of the glass fiber due to the dissolution of the binder in the reactive diluent is deeply involved in the cause of the defect. It turned out. This glass fiber is more difficult to be defibrated as the viscosity of the kneaded product is lower and the length of the cut piece of the glass fiber is shorter. However, if the length of the cut piece of glass fiber is too short, the effect of strengthening the product is not exerted. Therefore, the object of the present invention is to solve the above problems, to suppress the specific gravity to a low level, and, without impairing the impact strength of the product, to prevent the defects of the product, a material composition for a fiber-reinforced resin molded body, and The present invention provides a method for producing a fiber-reinforced resin molded body.

[0004]

The characteristic composition of the material composition for a fiber-reinforced resin molding of the present invention for the above purpose is that 100 parts of the synthetic resin is mixed with 50 to 2 inorganic salts as a filler.
In addition to blending 00 parts by weight, 20 to 30 parts by weight of cut pieces of glass fiber strands bound by a binder having a solubility of 20 to 60% in a reactive diluent contained in the synthetic resin are blended. Yes (Claim 1
Corresponding to). It is more preferable that the synthetic resin is an unsaturated polyester resin containing the reactive diluent as a resin viscosity modifier (corresponding to claim 2). Further, the characteristic means as the method for producing the fiber-reinforced resin molded product of the present invention for the above-mentioned purpose is to mix 50 to 200 parts by weight of inorganic salts as a filler with 100 parts of the synthetic resin, and then mix the mixture. A mixture containing 20 to 30 parts by weight of cut pieces of the glass fiber strand bound by a binder having a solubility of 20 to 60% in a reactive diluent contained in a synthetic resin is kneaded for 1 to 10 minutes, and after the kneading The point is that the kneaded product of (1) is press-molded (corresponding to claim 3), and further, the mixture may be kneaded for 1 to 5 minutes (corresponding to claim 4).

[0005]

Therefore, according to the material composition for a fiber-reinforced resin molded product having the characteristic constitution of the present invention, the specific gravity of the kneaded product is kept low by using a smaller amount of inorganic salt than the conventional filler as a filler, and the blending amount of the glass fiber is adjusted. While increasing the amount more than before, while preventing the deterioration of the matrix cohesive force of the kneaded material, at the same time improve the fluidity of the kneaded material, and by selecting a binder,
Dissolution of the binder in the cut pieces of glass fiber strands can be suppressed to prevent defibration. In addition, according to the configuration described in claim 2, B having the characteristics of the characteristic configuration of the present invention is added.
MC can be obtained. Further, according to the method for producing a fiber-reinforced resin molded body of the characteristic means of the present invention, as a filler,
Keeping the specific gravity of the kneaded material low by using less inorganic salts than before, while increasing the blending amount of glass fiber while preventing the decrease in the matrix cohesive force of the kneaded material, at the same time improving the fluidity of the kneaded material. Further, by selecting the binder and shortening the kneading time, it is possible to suppress the dissolution of the binder in the cut pieces of the glass fiber strand and prevent the defibration. If the means described in claim 4 is used, defibration of the glass fiber can be prevented more reliably.

[0006]

As a result of the above, with the material composition for a fiber-reinforced resin molded product according to claim 1 of the present invention, the impact resistance of the product can be maintained while keeping the specific gravity of the fiber-reinforced resin molded product as a product low. It is now possible to provide products that suppress wavy streaks and color unevenness without compromising quality. Incidentally, the claim 2
The structure described makes it possible to provide high quality artificial marble. Further, according to the characteristic means of the method for producing a fiber-reinforced resin molded product according to claim 3 of the present invention, handling of the kneaded product is facilitated and molding is facilitated, and at the same time, the impact resistance of the product is impaired. It is now possible to prevent wavy streaks and uneven color on the product. By the means as set forth in claim 4, while maintaining the impact resistance of the product, the wavy stripes of the product,
Color unevenness can be prevented more reliably.

[0007]

EXAMPLE An example of producing a fiber-reinforced resin molded article (hereinafter simply referred to as a product) by the method for producing a fiber-reinforced resin molded article of the present invention using the material composition for a fiber-reinforced resin molded article of the present invention. An example will be described. Unsaturated polyester resin (manufactured by Takeda Pharmaceutical Co., Ltd .: trade name Polymerl 93) to which a low shrinkage imparting agent (manufactured by Takeda Chemical Industry Co., Ltd .: blended with trade name Polymer 9996) as a synthetic resin is added.
05Z. ) Calcium carbonate (average particle diameter: 3.4 μm) is used as a filler in an amount of 150 to 200 parts by weight, and magnesium oxide is used in an amount of 1 part by weight as a thickening agent for improving the handling property during molding. 1 part by weight of t-butyl-peroxy-isopropyl-carbonate as a curing agent for curing polyester resin and styrene, to maintain the stability during material storage and to delay the initial curing reaction during molding, thus suppressing the reaction. Add 0.05 parts by weight of parabenzoquinone as an agent and 5 parts by weight of zinc stearate as an internal mold release agent to facilitate demolding at the time of molding, and mix thoroughly with a twin-screw planetary mixer. After kneading, the glass fiber strand (fiber diameter:
13 μm, number of bundles: about 500, binder: polyvinyl acetate) cut pieces (fiber length: 6 mm) 20 to 25 parts by weight of a mixture was mixed for 1 to 10 minutes (rotation speed) with a twin-screw planetary mixer. : 40 rpm)
To form BMC. The solubility of the polyvinyl acetate with respect to the styrene monomer in the reactive diluent (hereinafter, simply referred to as styrene solubility) is adjusted to 50%. Adjustment of styrene solubility of the binder,
Polyvinyl acetate having a resin skeleton soluble in styrene,
It was carried out by appropriately blending polyvinyl acetate having a resin skeleton insoluble in styrene. For this purpose, the binder resin was selected and blended from polyvinyl acetate, epoxy resin, urethane resin, vinyl chloride resin and the like. The BMC formed as described above is subjected to 2
Cured for 4 hours, mold temperature of core temperature 135 ℃, cavity temperature 120 ℃, molding pressure 100 kg / c
The product was heated and pressed under m ² for 10 minutes to obtain a product having a thickness of 10 mm. This product has a length of 450 mm and a width of 350 mm.
It is a mini bathtub-shaped actual product with a depth of about 180 mm.
The evaluation results of the above products were good. For comparison with the conventional technique, the styrene solubility of the binder of the glass fiber was adjusted to 80% as it was, and the styrene solubility was adjusted to 65%, and the other conditions were the same as those in the above-mentioned examples. Compared with what you got the product. The results are shown in the table below.
The impact value test was carried out by flatwise impact based on JIS K7062, and the sand bag impact test was conducted based on JIS A5712, and the presence or absence of defects was examined. The test piece for the impact value test has a width of 12.5 mm and a length of 5 with the length direction of the test piece taken from the bottom of the product in the width direction of the mini bathtub.
The required quantity was cut out with a size of 5 mm.

[0008]

[Table 1] note. Values not noted are parts by weight. * 1: Styrene-soluble 50% binder * 2: Styrene-soluble 65% binder * 3: Styrene-soluble 80% binder * 4: Kneading time after addition of glass fiber: Unit minutes * 5: Viscosity after kneading * 4: Unit 10 ⁴ Pa-s * 6: The unit of impact value is kJ / m ² or more, and more glass fiber with a styrene-soluble 50% binder than conventional 20 ~ 25% blended B
MC showed good results when kneading for 1 minute, and when kneading for 10 minutes, kneading was a little excessive and defibration of some glass fibers was not observed, but almost good results were shown. still,
Although not shown, when the kneading time is shorter than 1 minute, the kneading becomes insufficient and the defibration of the glass fibers can be prevented,
It was found that when the kneading time exceeded 10 minutes, the defibration of the glass fibers proceeded, resulting in bad results. Further, although the amount of the filler is reduced to reduce the viscosity of the kneaded product, in the present example, the viscosity of the kneaded product is high in spite of the large amount of the glass fiber compared to the comparative example. Is kept low. As shown in the table, when the styrene solubility of the glass fiber binder exceeds 60%, overall good results are not obtained. As described above, good results can be obtained by lowering the styrene solubility of the glass fiber binder, but if it is lower than 20%, the compatibility between the glass fiber and the synthetic resin is lowered and In some cases, the impact strength may be reduced, and inconvenience may occur in that the glass fibers are visible from the surface.

[Other Example] <1> In the example, BMC was formed by using an unsaturated polyester resin as a synthetic resin, but an acrylic resin containing methamethyl acrylate as a reactive diluent may be used. A product similar to the example can be manufactured. <2> Although calcium carbonate was used as the filler in the examples,
Barium sulfate, chemical resistant clay, aluminum hydroxide and the like can be used, and aluminum hydroxide is suitable for developing a marble pattern. <3> The compounding amount of the filler may be 50 to 150 parts,
If it is less than 100 parts by weight, the blending amount becomes insufficient, and the viscosity of the kneading degree becomes insufficient, resulting in the separation of the glass fiber and the resin and the settling of the glass fiber. It becomes too large, the defibration of glass fiber increases,
In addition to causing wrinkles after drying, the efficiency of taking out from the mixer is reduced.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry.

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Claims (4)

[Claims] 1. A material composition for a fiber-reinforced resin molded product, which comprises a synthetic resin, a filler, a cut piece of glass fiber strand, and the like, wherein 50 parts of the inorganic salt as the filler is added to 100 parts of the synthetic resin. 200 parts by weight is blended, and the solubility in the reactive diluent contained in the synthetic resin is 20 to 6
A material composition for a fiber-reinforced resin molded product, containing 20 to 30 parts by weight of cut pieces of the glass fiber strands bound by a binder of 0%. 2. The material composition for a fiber-reinforced resin molded product according to claim 1, wherein the synthetic resin is an unsaturated polyester resin containing the reactive diluent as a resin viscosity modifier. 3. A method for producing a fiber-reinforced resin molded product, which comprises a synthetic resin, a filler, cut pieces of glass fiber strands, etc., wherein 50 parts to 200 parts of an inorganic salt as the filler is added to 100 parts of the synthetic resin. A mixture in which 20 to 30 parts by weight of cut pieces of the glass fiber strands bound by a binder having a solubility of 20 to 60% in a reactive diluent contained in the synthetic resin is blended after mixing and mixing parts by weight. Is kneaded for 1 to 10 minutes, and the kneaded product after kneading is press-molded to produce a fiber-reinforced resin molded product. 4. The method for producing a fiber-reinforced resin molded product according to claim 3, wherein the mixture is kneaded for 1 to 5 minutes.