Thermosetting resin composition, resin molded article, and resin gear

Abstract

To provide a thermosetting resin composition by which a resin molded article having excellent compression strength can be formed, and a resin molded article and a resin gear having excellent compression strength.SOLUTION: A thermosetting resin composition contains (A) bis(2-oxazoline) compound, and (B) at least one kind of organic compound selected from the group consisting of an organic cyclic compound (note that carboxylic acid compound is excluded) having at least one polar functional group selected from the group consisting of hydroxyl group, amide group and carbonyl group, and at least one cyclic structure selected from the group consisting of alicycle, heterocycle and aromatic ring, and an organic chain compound expressed by the following general formula (B8). [In the formula (B8), R81 denotes alkyl group, and R82 denotes alkyl group having hydroxyl group.]SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a thermosetting resin composition, a resin molded product, and a resin gear. [Background technology]

[0002] Resin molded articles made of a fiber base material and a matrix resin are used in various fields because of their light weight and excellent mechanical properties. Regarding resin compositions forming the matrix resin, thermosetting resin compositions containing bis(2-oxazoline) compounds are known as those capable of forming crosslinked resins having excellent mechanical properties such as toughness and excellent heat resistance (for example, Patent Document 1 below, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-330896 Summary of the Invention [Problem to be solved by the invention]

[0004] Resin molded articles are also used for resin gears, etc., but resin gears used in automobile engines, drive units for electric motorcycles, etc. tend to have a larger load on the teeth due to the need to make the gears more compact and to replace metal gears, etc. In such applications, the resin molded articles are required to have high compressive strength.

[0005] Therefore, an object of the present invention is to provide a thermosetting resin composition capable of forming a resin molded article having excellent compressive strength, and a resin molded article and a resin gear having excellent compressive strength. [Means for solving the problem]

[0006] One aspect of the present invention relates to the following inventions [1] to [7]. [1] A thermosetting resin composition comprising: (A) a bis(2-oxazoline) compound; and (B) at least one organic compound selected from the group consisting of an organic cyclic compound (excluding carboxylic acid compounds) having at least one polar functional group selected from the group consisting of a hydroxyl group, an amide group, and a carbonyl group, and at least one cyclic structure selected from the group consisting of an alicyclic ring, a heterocyclic ring, and an aromatic ring, and an organic chain compound represented by the following general formula (B8): [ka] [In formula (B8), R 81 represents an alkyl group, and R 82 represents an alkyl group having a hydroxyl group. [2] The thermosetting resin composition according to [1], further comprising an aromatic diamine compound. [3] The thermosetting resin composition according to [2], wherein the content of the organic compound is 5 to 95 parts by mass when the total mass of the aromatic diamine compound and the organic compound is 100 parts by mass. [4] The thermosetting resin composition according to any one of [1] to [3], wherein the organic cyclic compound is 2-oxazolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, phthalamide, or N-(2,4,6-trichlorophenyl)maleimide. [5] A resin molded article comprising a cured product of the thermosetting resin composition according to any one of [1] to [4]. [6] A resin molded article comprising a fiber substrate and a cured product of the thermosetting resin composition according to any one of [1] to [4] impregnated into the fiber substrate. [7] A resin gear having a tooth portion made of the resin molded article described in [6]. Effect of the Invention

[0007] According to the present invention, it is possible to provide a thermosetting resin composition capable of forming a resin molded article having excellent compressive strength, and a resin molded article and a resin gear having excellent compressive strength. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the following embodiments.

[0009] <Thermosetting resin composition> The thermosetting resin composition of this embodiment contains (A) a bis(2-oxazoline) compound (hereinafter, sometimes referred to as "(A) component"); (B) an organic cyclic compound (excluding carboxylic acid compounds) having at least one polar functional group selected from the group consisting of a hydroxyl group, an amide group, and a carbonyl group, and at least one cyclic structure selected from the group consisting of an alicyclic ring, a heterocyclic ring, and an aromatic ring, and at least one organic compound selected from the group consisting of an organic chain compound represented by the following general formula (B8). According to the first thermosetting resin composition of this embodiment, a resin molded product having excellent compressive strength can be formed by, for example, impregnating a fiber substrate with the composition and curing it.

[0010] [ka] [In formula (B8), R 81 represents an alkyl group, R 82 represents an alkyl group having a hydroxyl group.

[0011] The thermosetting resin composition of the present embodiment may further contain, in addition to the above-mentioned component (B), a compound having two or more functional groups capable of reacting with and bonding to the component (A), such as a polyamine compound (hereinafter, sometimes referred to as "component (C)"). The component (C) may be blended alone or in combination of two or more kinds.

[0012] Examples of the polyamine compound include aromatic diamine compounds, etc. The thermosetting resin composition of the present embodiment may contain an aromatic diamine compound because it is inexpensive and easily available.

[0013] [Component (A)] The bis(2-oxazoline) compound can be used without any particular limitation as long as it has two oxazoline skeletons in one molecule. The two oxazoline skeletons may be bonded directly or via an organic group. The component (A) may be used alone or in combination of two or more.

[0014] The bis(2-oxazoline) compound may be a compound represented by the following general formula (A). [ka] [In formula (A), R 1 represents a single bond, an unsubstituted or substituted alkylene group, an unsubstituted or substituted phenylene group, or an unsubstituted or substituted pyridinediyl group; R 2 and R 3 each independently represents a hydrogen atom, an alkyl group, or a phenyl group.

[0015] R 1 When has a substituent, examples of the substituent include a methyl group.

[0016] Examples of component (A) include 2,2'-(1,3-phenylene)bis-2-oxazoline (hereinafter sometimes abbreviated as "PBO"), 2,2'-(1,4-phenylene)bis-2-oxazoline, 2,2'-(1,2-ethylene)bis-2-oxazoline, 2,2'-(1,4-butylene)bis-2-oxazoline, and 2,2'-(1,3-phenylene)bis-(5-methyl-2-oxazoline), (S,S)-2,6-bis(4-isopropyl-2-oxazolin-2-yl)pyridine, and (S,S)-2,2'-(dimethylmethylene)bis(4-phenyl-2-oxazoline).

[0017] The component (A) may be PBO since it is inexpensive and readily available.

[0018] The content of the component (A) in the thermosetting resin composition may be 25 to 75 mass % based on the total solid content of the thermosetting resin composition. The solid content of the thermosetting resin composition means the components other than the solvent (components that form a cured product).

[0019] [(B) Component] The component (B) is at least one organic compound selected from the group consisting of the above organic cyclic compounds (excluding carboxylic acid compounds) and the above organic chain compounds. The carboxylic acid compounds also include acid anhydride compounds. The component (B) may be used alone or in combination of two or more.

[0020] The organic cyclic compound may be a compound represented by the following general formulas (B1) to (B7).

[0021] [ka] [In formula (B1), R 11 represents a hydrogen atom or an acetyl group.

[0022] [ka] [In formula (B2), R 21 represents a vinyl group or an alkyl group having a hydroxyl group.

[0023] [ka] [In formula (B3), Ar 31 represents an unsubstituted or substituted aromatic group.

[0024] Ar31 The substituent of may be an amide group.

[0025] [ka] [In formula (B4), Ar 41 represents an aromatic group having a halogen atom.

[0026] [ka] [In formula (B5), Ar 51 and Ar 52 represents an unsubstituted or substituted aromatic group.

[0027] Ar 51 and Ar 52 The substituent of may be an amino group.

[0028] [ka] [In formula (B6), R 61 represents an alkyl group having a hydroxyl group.

[0029] [ka] [In formula (B7), R 71 and R 72 represents an alkyl group.

[0030] The organic cyclic compound may be a compound that satisfies one or more of the following conditions. (a) Having two or more polar functional groups selected from the group consisting of hydroxyl groups, amide groups, and carbonyl groups. (b) Having a chloro group.

[0031] The thermosetting resin composition of the present embodiment may contain, as component (B), at least one compound selected from the group consisting of 2-oxazolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, phthalamide, and N-(2,4,6-trichlorophenyl)maleimide.

[0032] The thermosetting resin composition of the present embodiment may contain, as component (B), at least one compound selected from the group consisting of 4,4'-diaminobenzanilide, 1-(2-hydroxyethyl)pyrrolidine-2,5-dione, 5,5-dimethylhydantoin, and N-(2-hydroxyethyl)acetamide.

[0033] From the viewpoint of improving the compressive strength of the resin molded product, the content of the (B) component in the thermosetting resin composition may be 0.03 to 1.0 mol, 0.03 to 0.15 mol, 0.2 to 0.8 mol, or 0.8 to 1.0 mol per 1 mol of the (A) component.

[0034] When the thermosetting resin composition contains an aromatic diamine compound, the content of the (B) component may be 5 to 95 parts by mass, 5 to 60 parts by mass, 5 to 30 parts by mass, 30 to 50 parts by mass, or 50 to 60 parts by mass, relative to 100 parts by mass of the total mass of the aromatic diamine compound and the (B) component, from the viewpoint of improving the compressive strength of the resin molded body.

[0035] [(C) component] Examples of aromatic diamine compounds include 4,4'-diaminodiphenylmethane (MDA), 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), methylenebis(2-ethyl-6-methylaniline) and 4,4'-methylenebis(2-ethylaniline).

[0036] The aromatic diamine compound may be an aromatic diamine compound containing a halogen atom such as a chlorine atom or a bromine atom in the molecule.

[0037] The molecular weight of the aromatic diamine compound may be 150 or more, or may be 300 or more, from the viewpoint of being less volatile, and may be 350 or less, from the viewpoint of the impregnation of the thermosetting resin composition into a fiber substrate or the like and ease of use in a liquid state.

[0038] The content of the (C) component in the thermosetting resin composition can be 0.05 to 0.50 mol per 1 mol of the (A) component from the viewpoint of forming a resin molded product having excellent compressive strength. The content of the (C) component in the thermosetting resin composition may be 0.05 to 2 mol, 0.05 to 0.5 mol, 0.5 to 1 mol, or 1 to 2 mol per 1 mol of the (A) component from the viewpoint of promoting a three-dimensional crosslinking reaction. The total content of the (B) component and the (C) component may be 0.05 to 2 mol, 0.05 to 0.8 mol, 0.8 to 1 mol, or 1 to 2 mol per 1 mol of the (A) component.

[0039] From the viewpoint of improving the compressive strength of the resin molded product, the content of the (C) component in the thermosetting resin composition may be 0.20 mol or more and 0.50 mol or less, 0.20 mol or more and less than 0.50 mol, 0.20 mol or more and 0.49 mol or less, 0.25 mol or more and 0.48 mol or less, or 0.25 mol or more and 0.40 mol or less, per 1 mol of the (A) component.

[0040] In addition, the total amount of the (B) component and the (C) component may be more than 0.20 mol and less than 1.50 mol, more than 0.20 mol and less than 1.50 mol, more than 0.20 mol and less than 1.49 mol, more than 0.20 mol and less than 1.48 mol, or more than 0.25 mol and less than 1.40 mol, per 1 mol of the (A) component.

[0041] The thermosetting resin composition of the present embodiment may contain a curing accelerator, if necessary, to accelerate the curing reaction between the bis(2-oxazoline) compound and the components (B) and (C), etc.

[0042] Examples of the curing accelerator include n-octyl bromide and p-toluenesulfonic acid esters such as ethyl p-toluenesulfonate.

[0043] The content of the curing accelerator in the thermosetting resin composition may be 0.5 to 1.2 parts by mass, 0.5 to 0.8 parts by mass, or 0.8 to 1.2 parts by mass, relative to 100 parts by mass of the total of the (A), (B), and (C) components.

[0044] The thermosetting resin composition of the present embodiment may contain additives such as a shock absorbing material such as rubber, an organic sliding material such as polyethylene glycol, etc. Examples of the shock absorbing material include silicone rubber, fluororubber, and nitrile rubber.

[0045] <Resin molded body> The resin molded article of the present embodiment includes a fibrous base material and a cured product of the thermosetting resin composition of the present embodiment impregnated into the fibrous base material.

[0046] [Fiber base material] Examples of the fiber substrate include thermoplastic resin fibers such as polyphenylene sulfide, polyamide (aliphatic polyamide, aromatic polyamide), polyethylene, and polypropylene, inorganic fibers such as basalt fiber, alumina fiber, glass fiber, and carbon fiber, and metal fibers such as stainless steel fiber and aluminum fiber. The fiber substrate may contain one type of fiber alone or two or more types of fibers in combination.

[0047] In the resin molded article of the present embodiment, the fiber base material may contain aramid fibers from the viewpoint of improving the compressive strength, tensile strength, bending strength, and impact strength.

[0048] The aramid fibers may be either para-aramid fibers (para-aramid fibers) or meta-aramid fibers (meta-aramid fibers), or a mixture of both may be used.

[0049] As the para-aramid fibers, fibers having molecular structures represented by the following formulas (1) and (2) can be used. [ka] [ka]

[0050] Examples of para-aramid fibers that can be used include commercially available products such as "Twaron" and "Technora" (both trade names manufactured by Teijin Limited), "Kevlar Pulp" (product name manufactured by Toray DuPont Co., Ltd.), "Taparan" (product name manufactured by Yantai Taiho New Materials Co., Ltd.), and "Heraklon" (product name manufactured by Kolon Industry Co., Ltd.).

[0051] As the meta-aramid fiber, a fiber having a molecular structure represented by the following formula (3) can be used. [ka]

[0052] As the meta-aramid fiber, commercially available products such as "Conex" (trade name, manufactured by Teijin Limited), "Nomex" (trade name, manufactured by DuPont Co., Ltd.), "Newstar" (trade name, manufactured by Yantai Taiho New Materials Co., Ltd.), and "Tametal" (trade name, manufactured by Yantai Taiho New Materials Co., Ltd.) can be used.

[0053] The content of the para-aramid fibers in the fiber base material may be 30 to 100 mass% or 40 to 100 mass% based on the total amount of aramid fibers contained in the fiber base material from the viewpoint of improving the compressive strength, and may be 80 to 100 mass% from the viewpoint of improving the tensile strength.

[0054] The content of the aramid fibers in the fiber substrate may be 50 to 100 mass %, 60 to 100 mass %, or 100 mass %, based on the total mass of the fiber substrate.

[0055] From the viewpoint of availability, the fiber length of the aramid fiber may be 1 to 12 mm, 1 to 2 mm, 3 to 6 mm, or 7 to 12 mm.

[0056] The fiber diameter of the aramid fiber may be 8 to 12 μm from the viewpoints of availability and permeability of the resin into the substrate.

[0057] The fiber substrate may contain an inorganic sliding material, such as carbon, molybdenum, molybdenum disulfide, potassium hexatitanate, potassium octatitanate, lithium potassium titanate, magnesium potassium titanate, and mica.

[0058] In the resin molded body of the present embodiment, from the viewpoint of obtaining a high level of compressive strength, the content of the inorganic sliding material in the resin molded body may be 10 parts by mass or less, or 5 parts by mass or less, relative to 100 parts by mass of the fiber base material, or the resin molded body may not contain an inorganic sliding material.

[0059] The proportion of the fiber base material in the resin molded body may be 35 to 55 volume %, 35 to 50 volume %, or 50 to 55 volume %, from the viewpoints of ensuring mechanical strength and the resin impregnation speed.

[0060] In addition, from the viewpoint of facilitating impregnation of the molten resin into the base material, the content of the fiber base material in the resin molded body may be 35 to 50 parts by mass, or may be 40 to 50 parts by mass, per 100 parts by mass of the fiber base material and the cured product of the thermosetting resin composition of this embodiment in total.

[0061] The resin molded article of the present embodiment can be used as an automobile part, a compressor part, a drone part, a medical machine part, etc. Examples of the parts include a resin gear and a rotor.

[0062] <Method of manufacturing resin molded body> The resin molded article of the present embodiment can be produced by impregnating a fiber base material with the thermosetting resin composition of the present embodiment, and then curing the thermosetting resin composition by heating.

[0063] In this embodiment, the fiber base material may be formed by a wet method in which paper is made in water.

[0064] The curing conditions for the thermosetting resin composition of this embodiment include, for example, conditions of 160° C. to 250° C. for 3 minutes to 20 minutes.

[0065] <Plastic gear> The resin gear of the present embodiment has teeth made of the resin molded article of the present embodiment. The teeth may be formed, for example, by using a teeth-shaped mold in the stage of curing the thermosetting resin composition of the present embodiment, or may be formed by cutting or the like after obtaining a resin molded article of a predetermined shape. EXAMPLES

[0066] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0067] The following compounds were prepared as raw materials for preparing a thermosetting resin composition.

[0068] <Component (A)> PBO: 2,2'-(1,3-phenylene)-bis-2-oxazoline (Mikuni Pharmaceutical Co., Ltd.)

[0069] <(B) component> OXZ: 2-Oxazolidone (Tokyo Chemical Industry Co., Ltd.) HEPL: 1-(2-hydroxyethyl)-2-pyrrolidone (Tokyo Chemical Industry Co., Ltd.) PTA: Phthalamide (Tokyo Chemical Industry Co., Ltd.) T1987: N-(2,4,6-trichlorophenyl)maleimide (Tokyo Chemical Industry Co., Ltd.) DABA: 4,4'-diaminobenzanilide (Tokyo Chemical Industry Co., Ltd.) 1,2-HEPO: 1-(2-hydroxyethyl)pyrrolidine-2,5-dione (Tokyo Chemical Industry Co., Ltd.) DMHD: 5,5-dimethylhydantoin (Tokyo Chemical Industry Co., Ltd.) HEAA: N-(2-hydroxyethyl)acetamide (Tokyo Chemical Industry Co., Ltd.)

[0070] <(C) component> MDA: 4,4'-diaminodiphenylmethane (manufactured by Manka Chemical Japan Co., Ltd.) BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane (manufactured by Wakayama Seika Holdings Co., Ltd.)

[0071] <Curing accelerator> OB: n-Octyl bromide (manufactured by Manac Corporation)

[0072] Example 1 PBO as component (A), OXZ as component (B), and MDA as component (C) were mixed in a mass ratio of 69:6:25, and heated to dissolve to form a liquid. OB as a curing accelerator was added to this liquid in a ratio of 0.7 parts by mass per 100 parts by mass of the total amount of components (A), (B), and (C) to obtain a thermosetting resin composition.

[0073] A fiber substrate was prepared by dissolving cut fibers (fiber length 3 mm) of para-aramid fiber (manufactured by Teijin Limited, product name Technora), cut fibers (fiber length 3 mm) of meta-aramid fiber (manufactured by Teijin Limited, product name Conex), and para-aramid fiber pulp (manufactured by Toray DuPont Co., Ltd., product name Kevlar) in water at a mass ratio of 42:53:5, and forming into a paper. This fiber substrate was compressed in the thickness direction in a papermaking die so that the ratio of the fiber substrate in the resin molded body (hereinafter sometimes referred to as the "fiber substrate volume ratio") was 40 volume %, and a rectangular parallelepiped reinforcing fiber assembly was obtained.

[0074] The rectangular reinforcing fiber aggregate obtained above was placed in a molding die and clamped, and the thermosetting resin composition prepared above was further injected and cured at a molding die temperature of 160°C for 5 minutes to mold a rectangular plate (resin molded body).

[0075] Example 2 A resin molded product was molded in the same manner as in Example 1, except that HEPL was used instead of OXZ as the component (B) and the molding die temperature was set to 180°C.

[0076] Example 3 A resin molded body was molded in the same manner as in Example 1, except that PTA was used instead of OXZ as the (B) component, the blending ratio of the (A), (B) and (C) components was 69:1:30 by mass, the blending amount of the curing accelerator was 0.5 parts by mass per 100 parts by mass of the total amount of the (A), (B) and (C) components, and the molding die temperature was 190°C.

[0077] Example 4 A resin molded body was molded in the same manner as in Example 1, except that T1987 was used instead of OXZ as the (B) component, the amount of the curing accelerator was 0.9 parts by mass per 100 parts by mass of the total amount of the (A), (B), and (C) components, and the molding die temperature was 180°C.

[0078] Example 5 A resin molded body was molded in the same manner as in Example 1, except that DABA was used instead of OXZ as the (B) component, the amount of the curing accelerator was 0.5 parts by mass per 100 parts by mass of the total amount of the (A), (B) and (C) components, and the molding die temperature was 190°C.

[0079] Example 6 A resin molded body was molded in the same manner as in Example 1, except that 1,2-HEPO was used instead of OXZ as the (B) component, the amount of the curing accelerator was 0.8 parts by mass per 100 parts by mass of the total amount of the (A), (B) and (C) components, and the molding die temperature was 190°C.

[0080] Example 7 A resin molded body was molded in the same manner as in Example 1, except that DMHD was used instead of OXZ as the (B) component, the amount of the curing accelerator was 0.9 parts by mass per 100 parts by mass of the total amount of the (A), (B) and (C) components, and the molding die temperature was 190°C.

[0081] Example 8 A resin molded body was molded in the same manner as in Example 1, except that HEAA was used instead of OXZ as the (B) component, the amount of the curing accelerator was 1.0 part by mass per 100 parts by mass of the total amount of the (A), (B), and (C) components, and the molding die temperature was 190°C.

[0082] Comparative Example 1 A resin molded body was molded in the same manner as in Example 1, except that the (B) component was not blended, the (A) component and the (C) component were mixed in a blending ratio of 69:31 by mass, the blending amount of the curing accelerator was 0.9 parts by mass per 100 parts by mass of the total amount of the (A) component and the (C) component, and the molding die temperature was 190°C.

[0083] Comparative Example 2 PBO and ethylenediaminetetraacetic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) as the component (A), and MDA as the component (C) were mixed in a mass ratio of 69:6:25, and were heated and dissolved to form a liquid. When this liquid was heated to 160°C, foaming occurred. When octyl bromide was further added to the foamed liquid in a ratio of 1.2 parts by mass per 100 parts by mass of the liquid, it was further foamed and cured. It was determined that sufficient compressive strength could not be obtained due to foaming, so molding of a resin molded product and its evaluation were not performed.

[0084] <Compression test> The resin molded bodies (rectangular plates) obtained in Examples 1 to 8 and Comparative Example 1 were polished on both sides and cut into pieces measuring 13 mm x 13 mm x 25 mm to prepare test pieces for compression testing. Compression tests were performed on these test pieces using an autograph AGS-5000 manufactured by Shimadzu Corporation to measure the compressive strength. This measurement was performed six times, and the maximum value is shown in Table 1.

[0085] [Table 1]

[0086] As shown in Table 1, it was confirmed that the resin moldings of Examples 1 to 8, which included the cured products of the thermosetting resin compositions containing the bis(2-oxazoline) compound and the specific organic cyclic compound or the specific organic chain compound, had excellent compressive strength.

Claims

1. (A) a bis(2-oxazoline) compound, and (B) at least one organic compound selected from the group consisting of organic cyclic compounds (excluding carboxylic acid compounds) having at least one polar functional group selected from the group consisting of a hydroxyl group, an amide group, and a carbonyl group, and at least one cyclic structure selected from the group consisting of an alicyclic ring, a heterocyclic ring, and an aromatic ring, and at least one organic chain compound represented by the following general formula (B8): A thermosetting resin composition comprising: 【Chemistry 1】 [In formula (B8), R ８１ represents an alkyl group, R ８２ represents an alkyl group having a hydroxyl group.

2. The thermosetting resin composition according to claim 1 , further comprising an aromatic diamine compound.

3. The thermosetting resin composition according to claim 2, wherein the content of the organic compound is 5 to 95 parts by mass when the total mass of the aromatic diamine compound and the organic compound is 100 parts by mass.

4. 2. The thermosetting resin composition according to claim 1, wherein the organic cyclic compound is 2-oxazolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, phthalamide, or N-(2,4,6-trichlorophenyl)maleimide.

5. A resin molded article comprising a cured product of the thermosetting resin composition according to any one of claims 1 to 4.

6. A resin molded article comprising a fiber substrate and a cured product of the thermosetting resin composition according to any one of claims 1 to 4 impregnated into the fiber substrate.

7. A resin gear having a tooth portion made of the resin molded product according to claim 6.

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