JPH07216126A - Low-expandable fiber-reinforced resin composition and its molding - Google Patents

Abstract

PURPOSE:To obtain the subject compsn. which gives a molding excellent in warpage resistance, dimensional stability, and mechanical characteristics by compounding a thermoplastic resin, a fibrous reinforcement, and an effective amt. of a blowing agent. CONSTITUTION:This resin compsn. comprises 100 pts.wt. thermoplastic resin, 5-100 pts.wt. fibrous reinforcement, and an effective amt., pref. 0.01-10 pts.wt., of a blowing agent. The resin may be amorphous, crystalline, or thermotropic crystalline. The blowing agent may be inorg. or org. The compsn. is melt molded to give a molding with excellent mechanical characteristics and markedly improved warpage reisistance and dimensional stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-foaming fiber-reinforced resin composition having excellent warp properties, dimensional stability and mechanical properties, and a molded product thereof.

[0002]

2. Description of the Related Art Thermoplastic resins are prepared by blending various fibrous reinforcing materials by utilizing their melting characteristics during heating.
It is widely used in the fields of electric / electronics, machinery, automobiles, construction materials, etc. by molding it into molded products of various shapes with greatly improved strength and rigidity.

However, when such a fibrous reinforcing material is filled, there is a drawback in that the molded product is largely warped. In order to improve this molding warp, a method of adding a granular filler having little anisotropy (for example, calcium carbonate, clay, diatomaceous earth, calcium metasilicate, talc, sericite, etc.) (for example, JP-A-53-121843).
JP-A-55-16049) and a method of adding a flat filler (for example, mica, glass flakes, etc.) (for example, JP-A-55-16049 and JP-A-5-16049).
6-93751, JP-B-57-57092), and a method of using a granular filler in combination with a fibrous reinforcing material (for example, JP-B-58-19697, JP-A-53-102).
No. 360, JP-A No. 54-17956), a method of using a fibrous reinforcing agent in combination with a tabular filler (for example, JP-A No. 62-59661, JP-A No. 1-282245-, JP-B-1). -1507), a method of using a granular filler and a flat filler together with a fibrous reinforcing agent (for example, JP-A-4-4249), and the like. When the composition obtained by these methods is used as a molded article, the effect of reducing the molding warp is slightly recognized, but the mechanical properties are deteriorated and there is a drawback that a sufficient effect cannot be obtained in practical use. Is the actual situation.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned drawbacks of the prior art, that is, the remarkable deterioration of mechanical properties of a molded product, and to obtain a fiber-reinforced resin processed product with less warpage. To provide products and their processed products.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies to achieve this object, and as a result, it is remarkable that a thermoplastic resin containing a fibrous reinforcing material contains an effective amount of a foaming agent. The inventors have found that it has an effect and arrived at the present invention.

That is, according to the present invention, an effective amount of a foaming agent is contained in a resin composition comprising a thermoplastic resin and 5 to 100 parts by weight of a fibrous reinforcing material with respect to 100 parts by weight of the resin. A low-foaming fiber-reinforced resin composition and a molded product thereof.

The thermoplastic resin used in the present invention may be any of an amorphous resin, a crystalline resin and a thermotropic liquid crystalline resin, and an engineering plastic excellent in mechanical properties has original strength characteristics from the field of use. In practical use, it is essential to maintain it to a level where there is no problem, so it is suitable for the present invention.

Accordingly, amorphous resins such as polysulfone, polyether sulfone, polyetherimide, polyarylate, polycarbonate, modified PPE, polyimide, polyamideimide, and crystalline resins such as polyamide, polyethylene terephthalate, polybutylene terephthalate, polyacetal and polyphenylene sulfide. , Polyketone, polyetherketone, polyetherketoneketone, polyetheretherketone, polyetherketoneetherketoneketone, polyethernitrile, thermotropic liquid crystalline resin, paraoxybenzoic acid, aromatic diol, aromatic in the main chain skeleton Group dicarboxylic acids,
Those containing a molecular structure such as a naphthalene ring, for example, Zyder (Amoco) for heat-resistant type I, Econol (Sumitomo Chemical Co., Ltd.) (all contain para-hydroxybenzoic acid, biphenol, terephthalic acid structure), heat-resistant type II Vectra (Ceranizu) (para-hydroxybenzoic acid, 6-hydroxy-2-naphthalenecarboxylic acid, containing terephthalic acid structure), Heat-resistant type III type is Rodran (Unitika) (para-hydroxybenzoic acid, containing polyethylene terephthalate structure) is the most preferable Used.

The fibrous reinforcing material used in the present invention may be either inorganic fibers or organic fibers. Inorganic fibers are ceramic, carbonaceous, metallic, whiskers, mineral fibers, and organic fibers are animal / vegetable fibers. Synthetic fibers are preferred. In particular, glass fibers and ceramic fibers for ceramics, PAN-based carbon fibers and pitch-based carbon fibers for carbonaceous materials, alumina fibers, stainless fibers, copper fibers, brass (brass) fibers for metallic materials, potassium titanate and silicon carbide for whiskers. , Graphite, aluminum borate, calcium sulfate, asbestos for mineral substances, and aliphatic polyamide, aromatic polyamide for organic substances are most preferably used.

The thickness of the fibrous reinforcing material is 0.1 to 30 μm,
The length is in the range of 2 to 8,000 μm, and various combinations of thickness and length are used.

The filling amount of the fibrous reinforcing material is 10
5 to 100 parts by weight is preferable with respect to 0 parts by weight. If it is less than 5 parts by weight, the mechanical properties of the resin will be insufficient, and if it exceeds 100 parts by weight, the molding processability will be significantly reduced.

The foaming agent used in the present invention may be either an inorganic foaming agent or an organic foaming agent, and examples of the inorganic foaming agent include sodium bicarbonate, ammonium carbonate, sodium boron hydride, silicon oxyhydride, and organic foaming agent. As the agent, azodicarbonamide, azobisisobutyronitrile, dinitropentamethylenetetramine,
4,4'oxybisbenzenesulfonyl hydrazide,
Paratoluenesulfonyl hydrazide, tetrazole,
The tetrazole metal salt and the like are most preferably used.

The amount of the foaming agent added is 0.01 to 100 parts by weight of the thermoplastic resin composition containing the fibrous reinforcing material.
10 parts by weight is preferred. If it is less than 0.01 part by weight, low warpage and dimensional stability are not sufficiently exhibited due to the foaming effect of the foaming agent. If it exceeds 10 parts by weight, the internal pressure inside the molten resin increases and the processing stability of the resin decreases. Even if it can be molded, the expansion ratio of the molded product becomes too large, or the foaming becomes uneven, so that the mechanical properties of the obtained molded product deteriorate.

In order to sufficiently bring out the effect of the present invention, in the thermoplastic resin / fibrous reinforcing material / foaming agent mixture, when the thermoplastic resin is an amorphous resin, + 50 ° C. or more based on its glass transition temperature is used. Decomposition of blowing agent in the range of + 250 ° C
There is a foaming temperature, when the thermoplastic resin is a crystalline resin, the decomposition / foaming temperature of the foaming agent is within the range of -50 ° C to + 150 ° C based on its melting point, and the thermoplastic resin is a thermotropic liquid crystalline In the case of a resin, it is preferable that the decomposition / foaming temperature of the foaming agent is in the range of -50 ° C to + 150 ° C based on the thermotropic liquid crystal manifestation temperature.

Other additives may be added to the resin composition of the present invention, if necessary, as long as the effects of the present invention are not impaired. For example, when the typical additives are listed by classifying the typical additives, (a) wear resistance improver: graphite, carborundum, silica powder, molybdenum disulfide, fluororesin, etc. (b) flame retardant improver: Antimony trioxide, magnesium carbonate, calcium carbonate, etc. (c) Electrical property improver: clay, mica, etc. (d) Tracking resistance improver: silica, etc. (e) Acid resistance improver: barium sulfate, calcium metasilicate, etc. ( f) Thermal conductivity improver: Metal powder (g) of iron, zinc, aluminum, copper, etc.
Others: glass beads, alumina, talc, diatomaceous earth,
Examples include kaolin, gypsum, calcium sulfite, and hydrated alumina.

Other additives used in ordinary molding resin compositions, such as lubricants, mold release agents, nucleating agents, plasticizers, heat stabilizers, UV absorbers, pigments, dyes and other thermoplastic resins. A thermosetting resin or the like can be added if necessary.

The method for producing the low-expansion fiber reinforced resin composition of the present invention is not particularly limited, but for example, (a) a raw material in which a thermoplastic resin, a fibrous reinforcing material, a foaming agent and other additives are blended together. To a screw type extruder for melt kneading, (b) a raw material containing a thermoplastic resin, a foaming agent, and other additives is fed to the screw type extruder to form a fibrous form during solvent kneading. A method of supplying a reinforcing material (side feed), (c) a thermoplastic resin, a fibrous reinforcing material, and a raw material mixed with other additives are melt-kneaded by a screw type extruder, and a predetermined amount of foam is formed on the obtained pellets. A method of adding and mixing agents can be adopted.

Further, the low foaming fiber reinforced resin composition of the present invention can be subjected to injection molding or extrusion molding which is a molding method having high productivity, but of course other compression molding, sintering molding, vacuum molding It can be used for molding and suction molding.

The molded product obtained by melt-molding the low-foaming fiber-reinforced composition of the present invention is excellent in mechanical properties because it is fiber-reinforced, and the warped deformability and dimensional stability of the molded product are remarkable. It has been improved and can be used for many purposes. For example, precision mechanical parts such as watches and cameras, tape recorders, video, stereo, computer parts, electric / electronic equipment parts such as IC sockets, automobile parts such as windruper, door handle, fuel lid, aircraft parts, sanitation Formulation of compositions useful in a wide range of fields such as food equipment parts, medical equipment parts, office equipment parts, special equipment parts, sliding members, high-order processed products applications, such as use as bases for coated products and resin plated products Can be provided.

[0020]

EXAMPLES The present invention will be described in more detail below with reference to examples. The values of%, ratio and parts shown below are by weight unless otherwise specified. The abbreviations used in the examples mean the following.

Amorphous resin PES: Polyether sulfone resin 4100P (ICI company) PEI: Polyetherimide resin 1000 (GE company) TPI: Polyimide resin 450 (Mitsui Toatsu Chemical) Crystalline resin PBT: Polybutylene terephthalate Resin C7000 (Teijin) PPS: Polyphenylene sulfide resin P-4 (Phillips) PEEK: Polyether-terketone resin 450P (ICI) Thermotropic liquid crystalline resin LCP1: Zyda-SRT300 (Amoco) LCP2: Vectra A950 (Ceranizu) LCP3: Rod Run LC-5000 (Unitika) Fibrous reinforcing material GF: Glass fiber (3 mm long chopped fiber) CF: Carbon fiber (3 mm long chopped fiber) BF: Al borate Minium fiber Arbolex (Shikoku Kasei Co., Ltd.) AF: Aramid fiber Kevlar 49 (DuPont) Foaming agent AC: Azodicarbonamide BT: 5,5'-bis-1H-tetrazole CT: Tetrazole calcium salt (CH ₂ N ₅ ) ₂ Ca Mechanical Properties FS: Bending Strength (Kg / mm ² ) FM: Bending Elastic Modulus (Kg / mm ² ) Izod: Izod Impact Strength (With Notch) (Kg cm / cm) Examples 1 and 2 Non PES (glass transition temperature (T
g) 225 ° C.), GF as a fibrous reinforcing material, and CT (decomposition and foaming peak temperature of 390 ° C.) as a foaming agent, respectively.
Blended in the ratio shown in, and the cylinder temperature is 310-350 ° C.
Melt kneading with a 30 mmφ twin-screw extruder set to
Extruded pellets of uniform composition were obtained.

Next, the pellets thus obtained were subjected to an injection molding machine set at 370 ° C., and a ribbed molded product and ASTM D-790 shown in FIG.
A test piece for mechanical property evaluation specified in D-256 was molded. The appearance (visual observation) of each of the molded products was good.

As shown in FIG. 1, a molded product with ribs for measuring the warpage was formed on a rectangular plate (rear surface in the figure) having a thickness of 175 mm × 45 mm and a thickness of 1.5 mm, and a length of 3 mm in the length direction.
The ribs 4 and 4'of two pieces (both long sides and the center) and two pieces (both short sides) in the width direction are attached at right angles to the rectangular plate.

As shown in FIG. 2, the forming sled is placed on a horizontal reference surface 2 in a state that the rectangular plate is turned upside down, and the right front side of the rib of FIG. 1 is brought into close contact with the reference surface. , The clearance h between the rib 4'on the side opposite to the gate portion 3 (left side of the front surface of the rib in FIG. 1) from the reference surface is measured, and the amount of molding warp (m
m).

The evaluation results are shown in Table 1.

[0026]

[Table 1] Comparative Examples 1 and 2 Example 1 except that the amount of the foaming agent was changed as shown in Table 1.
Extrusion pelletization was carried out in the same manner as in. However, in Comparative Example 2, the strands were easily broken, and the pered shape was uneven.

The pellets thus obtained were injection-molded in the same manner as in Example 1, and the same evaluation as in Example 1 was carried out using the ribbed molded product and the test piece for mechanical property evaluation.

Mottled patterns were scattered on the surface of the molded article of Comparative Example 2, and the appearance was poor.

The evaluation results are shown in Table 1.

As shown in Examples 1 and 2 and Comparative Examples 1 and 2, it is apparent that molded articles of the composition of the present invention, which are composed of a proper amount of PES / GF / CT, have excellent characteristics.

Example 3 and Comparative Example 3 Extrusion pelletization and injection molding were carried out in the same manner as in Example 1 and Comparative Example 1 except that PEI (Tg: 215 ° C.) was used as the amorphous thermoplastic resin.

Table 1 shows the evaluation results of the molded products.

From Example 3 and Comparative Example 3, it is apparent that the molded article of the composition of the present invention, which is composed of a proper amount of PEI / GF / CT, shows excellent characteristics.

Example 4 and Comparative Example 4 In Example 4, TPI was used as the amorphous thermoplastic resin.
(Tg: 250 ° C.), CF as a fibrous reinforcing material, and CT as a foaming agent were blended in the proportions shown in Table 1 without adding CT in Comparative Example 4, and the cylinder temperature was set to 350 to 400 ° C. The mixture was melt-kneaded with a 30 mmφ twin-screw extruder to obtain extruded pellets having a uniform composition.

Next, the pellets thus obtained were subjected to an injection molding machine set at 400 ° C., and a ribbed molded article and ASTM D-790 shown in FIG.
A test piece for mechanical property evaluation specified in D-256 was molded.

Table 1 shows the evaluation results of the molded products.

From Example 4 and Comparative Example 4, it is clear that, in the present invention, the molded article of the composition comprising the appropriate combination of TPI / CF / CT has excellent properties.

Examples 5 and 6 PBT (melting point (Tm) 225) as a crystalline thermoplastic resin
C.), GF as a fibrous reinforcing material, and AC (decomposition foaming peak temperature of 200 to 210.degree. C.) as a foaming agent in the proportions shown in Table 1, respectively, and a twin screw extruder of 30 mm.phi. Set to a cylinder temperature of 190 to 230.degree. Were melt-kneaded to obtain uniformly extruded pellets.

Next, the pellets thus obtained were subjected to an injection molding machine set at 240 ° C., and a mold temperature of 50 ° C. was applied.
Molded product with ribs and ASTM D-790, D
A test piece for mechanical property evaluation specified in -256 was molded.

Table 1 shows the evaluation results of the molded products.

Comparative Examples 5 and 6 Example 5 except that the amount of blowing agent was changed as shown in Table 1.
Extrusion pelletization was carried out in the same manner as in. However, in Comparative Example 6, the strands were easily broken and the pellet shapes were not uniform.

The obtained pellets were injection-molded in the same manner as in Example 5, and the same evaluation as in Example 5 was performed using the ribbed molded product and the test piece for mechanical property evaluation.

Mottled patterns were scattered on the surface of the molded article of Comparative Example 6, and the appearance was poor.

The evaluation results are shown in Table 1.

As shown in Examples 5 and 6 and Comparative Examples 5 and 6, it is apparent that molded articles of the composition of the present invention, which are composed of a proper amount of PBT / GF / AC, have excellent properties.

Examples 7 and 8 PPS (Tm: 290 ° C.) as a crystalline resin, GF as a fibrous reinforcing material, and BT (decomposition and foaming peak temperature 270 to 280 ° C.) as a foaming agent were mixed in the proportions shown in Table 1, respectively. And the cylinder temperature was set to 290-330 ℃, 30m
The mixture was melt-kneaded with an mφ twin-screw extruder to obtain uniformly dispersed extruded pellets.

Next, the pellets thus obtained are subjected to an injection molding machine set at 340 ° C., and a ribbed molded product and ASTM D-790 shown in FIG.
A test piece for mechanical property evaluation specified in D-256 was molded.

Table 1 shows the evaluation results of the molded products.

Comparative Examples 7 and 8 Example 7 except that the amount of foaming agent was changed as shown in Table 1.
Extrusion pelletization was carried out in the same manner as in. However, in Comparative Example 8, the strands were easily broken and the pellet shapes were not uniform.

The obtained pellets were injection-molded in the same manner as in Example 7, and the same evaluation as in Example 7 was carried out using the ribbed molded product and the test piece for mechanical property evaluation.

Mottled patterns were scattered on the surface of the molded article of Comparative Example 8, and the appearance was poor.

The evaluation results are shown in Table 1.

As shown in Examples 7 and 8 and Comparative Examples 7 and 8, it is apparent that molded articles of the composition of the present invention, which are composed of a proper combination of PPS, GF and BT, have excellent properties.

Example 9 and Comparative Example 9 In Example 9, PEEK (Tm:
334 ° C), AF as a fibrous reinforcing material, C as a foaming agent
In Comparative Example 9, T was blended in the proportions shown in Table 1 without adding CT, and the cylinder temperature was from 330 to
The mixture was melt-kneaded with a 30 mmφ twin-screw extruder set at 360 ° C. to obtain uniformly dispersed extruded pellets.

Next, the pellets thus obtained are subjected to an injection molding machine set at 370 ° C., and a ribbed molded product and ASTM-D-790 shown in FIG.
A test piece for mechanical property evaluation specified in D-256 was molded.

Table 1 shows the evaluation results of the molded products.

From Example 9 and Comparative Example 9, it is clear that the molded article of the composition of the present invention, which is composed of a proper amount of PEEK / AF / CT, shows excellent characteristics.

Example 10 and Comparative Example 10 In Example 10, LCPI was used as the thermotropic liquid crystalline resin, GF was used as the fibrous reinforcing material, and C was used as the foaming agent.
In Comparative Example 10, T was blended in the proportions shown in Table 1 without adding CT, and the cylinder temperature was 350.
The mixture was melt-kneaded with a 30 mmφ twin-screw extruder set at ˜380 ° C. to obtain uniformly dispersed extruded pellets.

Next, the pellets thus obtained are subjected to an injection molding machine set at 390 ° C., and a molded product with ribs and ASTM D-790, D shown in FIG.
A test piece for mechanical property evaluation specified in -256 was molded.

Table 1 shows the evaluation results of the molded products.

From Example 10 and Comparative Example 10, it is clear that the molded article of the composition of the present invention, which is composed of a proper combination of LCPI / GF / CT, exhibits excellent properties.

Example 11 and Comparative Example 11 In Example 11, LCP2 was used as the thermotropic liquid crystalline resin, GF was used as the fibrous reinforcing material, and B was used as the foaming agent.
In Comparative Example 11, T was added in the proportions shown in Table 1 without adding BT, and the cylinder temperature was set to 250.
The mixture was melt-kneaded with a 30 mmφ twin-screw extruder set at ˜280 ° C. to obtain uniformly dispersed extruded pellets.

Next, the pellets thus obtained were subjected to an injection molding machine set at 290 ° C., and a molded product with ribs and ASTM D-790, D shown in FIG.
A test piece for mechanical property evaluation specified in -256 was molded.

Table 1 shows the evaluation results of the molded products.

From Example 11 and Comparative Example 11, it is clear that the molded product of the composition of the present invention, which is composed of an appropriate amount of LCP2.GF.BT, exhibits excellent properties.

Example 12 and Comparative Example 12 In Example 12, LCP3 was used as the thermotropic liquid crystalline resin, GF was used as the fibrous reinforcing material, and A was used as the foaming agent.
In Comparative Example 12, C was added in the proportions shown in Table 1 without adding AC, and the cylinder temperature was set to 190.
The mixture was melt-kneaded with a 30 mmφ twin-screw extruder set to ˜230 ° C. to obtain uniformly dispersed extruded pellets.

Next, the pellets thus obtained were subjected to an injection molding machine set at 240 ° C., and a mold temperature of 50 ° C. was applied.
Molded product with ribs and ASTM D-790, D-
A test piece for mechanical property evaluation specified in 256 was molded.

Table 1 shows the evaluation results of the molded products.

From Example 12 and Comparative Example 12, it is clear that the molded product of the composition comprising the combination of LCP3.GF.AC in an appropriate amount in the present invention exhibits excellent properties.

[0070]

As described above, the resin composition of the present invention comprising a thermoplastic resin containing a fibrous reinforcing material and an effective amount of a foaming agent has a significantly suppressed amount of warp deformation of a molded article. In addition, it is possible to provide a fiber-reinforced resin processed product having excellent mechanical properties, and it can be widely used for various industrial equipment that has not been practically used due to warpage deformation.

[Brief description of drawings]

FIG. 1 is a perspective view showing a shape dimension of a molded product with ribs for measuring a warpage.

FIG. 2 is a diagram showing a method of measuring a molding warp.

[Explanation of symbols]

 1 Molded product with ribs (test sample) 2 Reference surface 3 Gate part 4, 4'Rib h Clearance

Claims (18)

[Claims] 1. A low foaming property, which comprises an effective amount of a foaming agent in a resin composition comprising a thermoplastic resin and 5 to 100 parts by weight of a fibrous reinforcing material with respect to 100 parts by weight of the resin. Fiber-reinforced resin composition and molded products thereof. 2. A low-foaming fiber-reinforced resin composition containing 0.01 to 10 parts by weight of a foaming agent relative to 100 parts by weight of the resin composition according to claim 1, and a molded product thereof. 3. The low-foaming fiber-reinforced resin composition according to claim 1, wherein the thermoplastic resin is an amorphous resin, and molded products thereof. 4. The low-expansion fiber-reinforced resin according to claim 3, wherein the amorphous resin is selected from the group consisting of polysulfone, polyether sulfone, polyetherimide, polyarylate, polycarbonate, modified PPE, polyimide, and polyamideimide. Compositions and molded products thereof. 5. The low-foaming fiber-reinforced resin composition according to claim 1, wherein the thermoplastic resin is a crystalline resin, and molded products thereof. 6. The crystalline resin is polyamide, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyphenylene sulfide, polyketone,
The low-foaming fiber-reinforced resin composition according to claim 5, which is selected from the group consisting of polyetherketone, polyetherketoneketone, polyetheretherketone, polyetherketoneetherketoneketone, and polyethernitrile, and molded products thereof. 7. The low-foaming fiber-reinforced resin composition according to claim 1, wherein the thermoplastic resin is a thermotropic liquid crystalline resin, and molded products thereof. 8. The thermotropic liquid crystalline resin contains a molecular structure selected from the group consisting of paraoxybenzoic acid, aromatic diol, aromatic dicarboxylic acid, and naphthalene ring in its main chain skeleton. Low foaming fiber reinforced resin composition and molded products thereof. 9. The fibrous reinforcing material is ceramic, carbonaceous,
The low-foaming fiber-reinforced resin composition according to claim 1, which is an inorganic fiber selected from the group consisting of metallic materials, whiskers, and mineral substances, and molded products thereof. 10. The low-foaming fiber-reinforced resin composition according to claim 9, wherein the ceramic fibrous reinforcing material is selected from the group consisting of glass fibers and ceramic fibers, and molded products thereof. 11. The low-foaming fiber-reinforced composition according to claim 9, wherein the carbonaceous fibrous reinforcing material is selected from the group consisting of PAN-based carbon fibers and pitch-based carbon fibers, and molded products thereof. 12. The metallic fibrous reinforcing material is alumina fiber,
The low-foaming fiber-reinforced resin composition according to claim 9, which is selected from the group consisting of stainless fibers, copper fibers and brass fibers, and successfully processed products thereof. 13. The low-foaming fiber-reinforced resin composition according to claim 9, wherein the whiskers are selected from the group consisting of potassium titanate, silicon carbide, graphite, aluminum borate and calcium sulfate, and molded products thereof. 14. The low-foaming fiber-reinforced resin composition according to claim 9, wherein the mineral fibrous reinforcing material is asbestos, and a molded product thereof. 15. The low-foaming fiber-reinforced resin composition according to claim 1, and a molded product thereof, wherein the fibrous reinforcing material is an organic fiber selected from the group consisting of animal and vegetable fibers and synthetic fibers. 16. The low foamable fiber reinforced resin composition according to claim 15, wherein the organic fiber is selected from the group consisting of an aliphatic polyamide fiber and an aromatic polyamide fiber, and a molded product thereof. 17. A low foaming fiber reinforced resin composition according to claim 1, wherein the foaming agent is an inorganic foaming agent selected from the group consisting of sodium bicarbonate, ammonium carbonate, sodium boron hydride and silicon oxyhydride. Molded products. 18. A group of foaming agents consisting of azodicarbonamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, 4,4'oxybisbenzenesulfonylhydrazide, paratoluenesulfonylhydrazide, tetrazole and tetrazole metal salts. The low-foaming fiber-reinforced resin composition according to claim 1, which is an organic foaming agent selected from the following, and molded products thereof.