JPH0582858B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a phenolic resin molding material for power transmission materials. More specifically, the present invention provides notched isot impact strength (hereinafter simply referred to as impact strength) and bending strength suitable for power transmission materials such as gears, cams, chains, belts, pulleys, stators, and impellers. The present invention relates to a phenolic resin molding material for power transmission materials, which simultaneously has contradictory properties such as high strength, sufficient resistance to repeated impacts, and heat resistance, and has an excellent balance of physical properties. BACKGROUND ART Conventionally, as molding materials for power transmission materials, for example, polyacetal resins, glass fiber-reinforced polyamide resins, modified polyamide resins, glass fiber-based phenolic resin molding materials, etc. are often used. By the way, molding materials for power transmission materials are generally required to have physical properties such as high impact strength and bending strength, sufficient resistance to repeated impacts, and heat resistance. , are contradictory to each other, so it was virtually impossible to simultaneously satisfy all of them at a high level. For example, since polyacetal resin is a thermoplastic resin, it has low heat resistance and has drawbacks such as melting of the surface or creeping when rotated at high speed. Moreover, although the bending strength and impact strength are well balanced, their values are low. Furthermore, although glass fiber reinforced polyamide resins and modified polyamide resins are reinforced with glass fibers, their base materials are thermoplastic resins, so their surfaces may melt at high temperatures or during high speed rotation, causing slippage and creep. I can't help but do it. Another disadvantage is that it produces unpleasant frictional noises during use. On the other hand, although the glass fiber-based phenolic resin molding material has extremely high bending strength, the elongation of the material is extremely low, so the impact strength is low at only 3 to 5 kg cm/cm, and the glass fiber is Since it cannot accommodate the elongation of the material, it cannot sufficiently withstand repeated impacts. Furthermore, when used as a power transmission material, it has the disadvantage that it is insufficiently able to absorb the frictional noise that accompanies rotation, etc., and generates noise. As described above, conventional molding materials for power transmission materials are not fully satisfactory for severe applications, and the reality is that no material has been found that balances the above-mentioned contradictory physical properties. be. Problems to be Solved by the Invention Under these circumstances, the object of the present invention is to provide a material that has high impact strength and bending strength, can withstand repeated impacts sufficiently, and does not melt or creep on the surface during power transmission. The object of the present invention is to provide a molding material suitable for use as a power transmission material, which simultaneously satisfies contradictory properties such as heat resistance, and has well-balanced physical properties. Means for Solving the Problems Although some of the physical properties required for power transmission materials are contradictory, the present inventors have developed a sea-island structure to improve the strength of the fiber-reinforced resin component and the rubber component. As a result of intensive research, we focused on the possibility that it would be possible to have both of these qualities at the same time by adhering them together.
For phenolic resin modified with a certain compound,
The inventors have discovered that the above object can be achieved by containing a fibrous base material having a specific tensile strength and strength and a predetermined amount of unvulcanized rubber or partially vulcanized rubber, and have completed the present invention. I've reached it. That is, the present invention provides (A) a phenolic resin 100 modified with at least one compound selected from cardol, anacardic acid, and cardanol.
Weight part, (B) At least one type of fibrous base selected from glass, organic fiber, twisted yarn, chip-like cloth, and cloth having a tensile strength of 6 g/denier or more and a tenacity of 12 g or more. Material 25～
The object of the present invention is to provide a phenolic resin molding material for power transmission materials, comprising 125 parts by weight and (C) 10 to 100 parts by weight of unvulcanized rubber or partially vulcanized rubber. The phenolic resin used in the molding material of the present invention is a phenolic resin modified with at least one compound selected from cardol, anacardic acid, and cardanol. Examples of the phenolic resin to be modified include novolak, resol, and benzyl ether. Although any type of phenolic resin can be used, novolak is preferred in terms of moldability. These have strong adhesion to unvulcanized or partially vulcanized rubber, and thus form a strongly bonded sea-island structure. When modifying the cardol, anacardic acid, and cardanol alone or in combination, the amount is 10 to 100 parts by weight, preferably 25 to 65 parts by weight, based on 100 parts by weight of phenols such as phenol, cresol, and resorcinol. used. If this amount is less than 10 parts by weight, the compatibility with unvulcanized rubber or partially vulcanized rubber will be low and the impact strength will be low, which is not preferable. Moreover, if it exceeds 100 parts by weight, the bending strength and heat resistance will decrease. Each of the cardol, anacardic acid and cardanol may be used alone or in combination with two
Although more than one type may be used in combination, it is particularly preferable to use two types, cardol and anacardic acid, in combination. Cashew oil is one that contains these. In the molding material of the present invention, the fibrous base material has a tensile strength of 6 g/denier or more, and
Glass, organic fibers, twisted yarn, chip-like cloth, and cloth having a tenacity of 12 g or more, preferably 30 g or more are used. These may be used alone or in combination of two or more. Also, those with a tensile strength of 12 g or more but less than 6 g/denier [for example, tensile strength of 2
Rayon chopped strands (hereinafter referred to as rayon chops) with ~3 g/denier and 12 g strength do not sufficiently improve impact strength and bending strength, and have a tensile strength of less than 6 g/denier. In addition, a fibrous base material having a tenacity of less than 12 g has low impact strength and bending strength, and the object of the present invention cannot be achieved. Thus, the essential requirement for a fibrous base material for reinforcing a rubber-modified phenolic resin is not only the Young's modulus of the fibers or the tensile strength, but also the satisfaction of both tensile strength and tenacity. This means that even if fibers with the same tensile strength are used in the same weight part relative to the resin, the impact strength will be significantly improved just by increasing the fiber diameter and strength, or that the impact strength of fibers such as cotton chips will be significantly improved. This is also clear from the fact that although it is large, the tensile strength is small, so the effect of improving impact strength is extremely small. Note that the tensile strength here refers to the strength with respect to a certain thickness, and is expressed as a load per unit area. The unit is common to fibers, twisted yarns, chip-like cloths, and cloths, and is expressed in g/denier of a single fiber. In addition, "strong" simply refers to the strength of the object itself without considering its thickness, and is the load obtained by multiplying the tensile strength by the thickness (denier), and the unit is fiber, twisted yarn, chip-like The symbol g is commonly used for cloths and cloths, but in the case of twisted threads, it means g/1 thread, and in the case of chip-shaped cloths and cloths, it means warp x weft g/width of 25 mm. In the molding material of the present invention, the blending ratio of the fibrous base material is selected in the range of 25 to 125 parts by weight, preferably 40 to 80 parts by weight, based on 100 parts by weight of the phenolic resin. If this amount is less than 25 parts by weight,
Improving impact strength and bending strength is insufficient,
Moreover, if it exceeds 125 parts by weight, molding becomes difficult and is not suitable for practical use. Examples of fibrous base materials include polyvinyl alcohol fibers (hereinafter referred to as vinylon fibers), polyamide fibers (hereinafter referred to as nylon fibers), rayon fibers, hemp such as ramie, flax, hemp, or surface-treated polyester fibers. , aramid fiber, carbon fiber, glass fiber, etc. are suitable, and these may be used alone or in combination of two or more. Among them, rayon fibers, hemp surface-treated aramid fibers, surface-treated carbon fibers, and surface-treated glass fibers have a small temperature dependence of Young's modulus even at high temperatures, and it is difficult to blend fibrous base materials made of these fibers. The resulting phenolic resin molding material has physical properties such as bending strength and tensile strength that hardly deteriorate even at high temperatures, so the resulting power transmission material can be used satisfactorily even in a heated environment, making it particularly suitable. At this time, glass fibers are treated with a silane coupling agent, and aramid fibers and polyester fibers have poor reactivity with resins, so after pretreatment such as alkali treatment, resorcinol resin, resol type phenol resin, Used after surface treatment with epoxy resin etc. The fibrous base material is used in the form of fibers, twisted threads, chip-like cloths, and cloths, and the fiber length is not particularly limited, but is preferably about 1 to 10 mm. Also, twisted yarn,
The chip-shaped cloth and the cloth may be used as they are, but it is preferable to use them after hardening them with an adhesive.
In that case, suitable adhesives include rubber-modified resorcinol resins, rubber-modified ammonia resol resins, and rubber-modified resol resins that have elongation. In the molding material of the present invention, the amount of unvulcanized rubber or partially vulcanized rubber is 10 to 100 parts by weight, preferably 40 to 80 parts by weight, based on 100 parts by weight of the phenolic resin.
It is blended within the range of parts by weight. If this amount is less than 10 parts by weight, the impact strength will not be improved sufficiently. Also
If it exceeds 100 parts by weight, bending strength decreases and heat creep resistance deteriorates, which is not preferable. Examples of the unvulcanized rubber include acrylonitrile butadiene rubber (NBR) and chloroprene rubber (CR).
etc., and these are used alone or in combination. Further, as the partially vulcanized rubber, vulcanizates such as NBR and CR are used alone or in combination. Sulfur or sulfur and zinc white is usually used as the vulcanizing agent. The amount added is not particularly limited, but it is usually preferably in the range of about 0.1 to 1.5 parts by weight per 100 parts by weight of unvulcanized rubber.
A power transmission material obtained from a phenolic resin molding material blended with partially vulcanized rubber has the characteristic that it can be suitably used especially in a heated environment. This molding material can also be further cured by after-curing.
It has the characteristics that the bending strength is improved with almost no decrease in impact strength, and it can be suitably used even in a heated environment. The phenolic resin molding material for power transmission materials of the present invention can be produced by a conventional method. For example, glass having a tensile strength of 6 g/denier or more and a tenacity of 12 g or more in 100 parts by weight of a phenolic resin modified with at least one of cardol, anacardic acid, and cardanol;
At least one type of fibrous base material selected from organic fibers, twisted yarn, chip-like cloth, and cloth
25 to 125 parts by weight and 10 to 100 parts by weight of unvulcanized rubber or partially vulcanized rubber, and if necessary, appropriate amounts of inorganic powder such as calcium carbonate, curing agent, curing catalyst, mold release. Additives such as additives and coloring agents are mixed, and this is uniformly dispersed and mixed with an appropriate amount of solvent using a Henschel mixer, etc., then kneaded using heated rolls, and then formed into a sheet using chilled rolls. In this way, a sheet-like phenolic resin molding material is obtained. There are no particular restrictions on the method for molding the molding material of the present invention, and any method commonly used can be used. The partially vulcanized rubber used instead of the unvulcanized rubber can be obtained by adding an appropriate amount of vulcanizing agent to the unvulcanized rubber and kneading it with a roll. In the thus obtained phenolic resin molding material for power transmission materials of the present invention, the unvulcanized rubber or partially vulcanized rubber is moderately compatible with the rigid sea of the modified phenolic resin. , it has a sea-island structure in the form of floating islands, and the sea and islands are connected by strong adhesive force. Furthermore, a fibrous base material with high tensile strength and strength is uniformly dispersed in this ocean of resin with a sea-island structure, and this fibrous base material and the modified phenolic resin are strongly bonded by chemical bonds. . Here, to explain the strong adhesive force between the sea and the island, if this adhesive force is weak, even if the degree of fiber reinforcement is increased, the impact strength will improve, but the bending strength will decrease, and the Even if the impact strength is increased by increasing sulfurized rubber or partially vulcanized rubber, the so-called rubber component, the bending strength similarly decreases significantly. Therefore, it is necessary to increase the adhesive strength between the rubber component and the modified phenolic resin. was found to be an essential requirement. This adhesive strength was achieved by modifying the resin with at least one compound selected from cardol, anacardic acid, and cardanol. In addition, to explain the strong adhesive force between the fibrous base material to be reinforced and the modified phenolic resin, some of the materials made of vinylon fiber, nylon fiber, rayon fiber, hemp, carbon fiber, etc.
In many cases, the modified phenolic resin and its surface react with each other during molding, forming strong chemical bonds. Glass fibers are treated with a silane coupling agent, and those made of polyester fibers, aramid fibers, etc. are pretreated with alkali, etc. After that, the object of the present invention can be achieved only when bonded with the modified phenolic resin with a strong adhesive force by surface treatment with the adhesive. It was found that bonding with adhesive force is also an essential requirement. This strong bonding force between the fibrous base material and the modified phenolic resin is effective in significantly increasing the repeated impact strength. For these reasons, the molding material of the present invention has improved impact strength, bending strength, and repeated impact strength. In addition, fibrous base materials made of rayon fibers, hemp, surface-treated aramid fibers, carbon fibers, or glass fibers, as well as partially vulcanized rubber, have a small temperature dependence of Young's modulus even at high temperatures, making them suitable for power transmission materials. Among the required physical properties, it is particularly effective in suppressing deterioration of physical properties such as bending strength and tensile strength at high temperatures. Furthermore, by using the twisted yarn, chip-shaped cloth, and cloth fixed with an adhesive having elongation, the twisted yarn, chip-shaped cloth, and cloth are prevented from unraveling during material manufacturing, and the lengthwise and horizontal directions of these fibers are The tensile strength and strength in the direction are increased. Effects of the Invention The phenolic resin molding material for power transmission materials of the present invention has high impact strength and bending strength, can withstand repeated impacts sufficiently, and has heat resistance, which are contradictory properties at the same time, and has well-balanced physical properties. It is suitable for use in power transmission materials such as gears, cams, chains, belts, pulleys, stators, and impellers, and has extremely high industrial value. In addition, as a fibrous base material, rayon fiber, hemp or surface-treated aramid fiber, carbon fiber,
By using glass fiber, it is possible to obtain a molding material with a good balance of physical properties even when heated, and power transmission materials made from this material have the advantage that they can be used satisfactorily even in heated environments. . Examples Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. Note that the physical properties were measured according to the method shown below. (1) Impact strength and bending strength Measured according to JIS K6911. (2) Repeated impact strength Measure using the test equipment shown in the attached drawings. i.e. width 12.7mm, thickness 1.6mm, length 127mm
After attaching the test piece 1 to the test piece support stand 2 so that the length of the test piece measurement area is 105 mm,
Rotating blade 3 made of steel S45C (blade length 50 mm, total length 100 mm, width 40 mm, thickness 2.6 mm, blade weight 82
g, rotational speed 1440 r.pm) and repeatedly impacts the test piece striking part 4 at the tip 5 mm of the test piece measurement site, and the time t until the test piece 1 breaks or deforms. (minutes)
was measured, and the number of repeated impacts N was determined by the following formula, and this N was taken as the repeated impact strength. N = 2 x 1440 x t (t: measurement time (minutes)) (3) Heat distortion temperature 18.6 according to load deflection temperature of JIS K6911
Measured under a load of Kg/ ^cm2 . Production example Production of modified phenolic resin Phenol 100 parts by weight 92% paraformaldehyde 87 Cashew oil (Cardalite D-10, manufactured by Ito Seiki)
40 〃 Oxalic acid 0.5 〃 Charge all the above raw materials into a four-necked flask equipped with a thermometer, stirrer and condenser, and pour the contents.
After raising the temperature to 120℃ to completely dissolve it, raise the temperature to 100℃.
The condensation reaction was carried out under reflux for 3 hours. Then, after dehydrating by raising the temperature to 200℃ under normal pressure,
The contents were taken out from the flask and cooled to obtain a cashew-modified phenolic resin. The softening point of the obtained resin was 60℃, and the flow at 10% hexa was 67mm/125
The gel time was 40 seconds/150°C. Example 1 100 parts by weight of the above-mentioned modified phenolic resin vinylon yop (tensile strength 7.8 g/denier,
Thickness: 6 denier, strength: 46.8 g, fiber length: 6 mm)
63 〃 NBR 63 〃 Calcium carbonate 25 〃 Hexamethylenetetramine 15 〃 Magnesium oxide 3 〃 Stearic acid 3 〃 The above mixture was uniformly dispersed and mixed with an appropriate amount of solvent in a Henschel mixer, and then heated on a heated roll (95℃/
Kneading was performed at 85° C. for 4 to 5 minutes to obtain a sheet-like phenolic resin molding material. This sheet-like phenolic resin molding material is cut into an appropriate size and compression molded using a conventional method.
A test piece was prepared, and its bending strength and repeated impact strength were measured. Impact strength at room temperature (25℃) A ₂₅ , bending strength σ ₂₅ ,
The cyclic impact strength N ₂₅ and heat distortion temperature T ₂₅ were measured. In addition, the bending strength σ ₁₀₀ when heated (100° C.) was measured, and the ratio σ ₁₀₀ /σ ₂₅ was determined. As a result, impact strength A ₂₅ 18.7Kg at room temperature
cm/cm, bending strength σ ₂₅ 7.2 Kg/mm ² , repeated impact strength N ₂₅ 10 ⁶ times, thermal deformation temperature T ₂₅ 125°C, and bending strength ratio σ ₁₀₀ /σ ₂₅ 0.40. In addition, after-cure (after-cure standard conditions: raise the temperature from room temperature to 150℃ in 5 to 10 hours,
℃ for 3 hours), and the impact strength A ₂₅ and bending strength σ ₂₅ at room temperature (25℃) were measured. the result,
Impact strength A ₂₅ 15.7Kg・cm/cm, bending strength σ ₂₅ 11.2
Kg/mm ² and was an excellent molding material that could be used satisfactorily even in a heated environment. The molding material thus obtained was a molding material with an excellent balance of physical properties that satisfied all the physical properties required for a power transmission material. Example 2 After adding 0.9 parts by weight of sulfur while kneading 63 parts by weight of NBR (Nipole 1041 manufactured by Nippon Zeon) on a hot roll (front/back = 95°C/85°C), an additional 4 to 5 parts by weight of sulfur was added.
Partial kneading was performed to obtain partially vulcanized NBR. 100 parts by weight of the modified phenolic resin was immersed in this kneaded material in a 20% methyl ethyl ketone (MEK) solution of resorcinol resin-NBR rubber, and then
Rayon cord (tensile strength 6.4 g/
Denier, thickness 2 denier, strong 260g/1 piece,
After adding 63 parts by weight of 20 filaments per twisted yarn, 10 mm cut product, 25 parts by weight of calcium carbonate, 15 parts by weight of hexamethylenetetramine, 3 parts by weight of magnesium oxide, and 3 parts by weight of stearic acid, the mixture was heated on a hot roll. Kneading was performed for 4 to 5 minutes at (95°C/85°C) to obtain a sheet-like phenolic resin molding material. This sheet-shaped phenolic resin molding material is cut into appropriate sizes and compression molded using a conventional method.
The physical properties required for power transmission materials were measured at room temperature (25°C). The test results were as shown in Table 1 above. In addition, we measured the bending strength σ ₁₀₀ when heated (100℃),
The ratio σ ₁₀₀ /σ ₂₅ was determined. As a result, a bending strength ratio of σ ₁₀₀ /σ ₂₅ of 0.50 was obtained, which was higher than that of Example 1, and was an excellent molding material that could be used satisfactorily even in a heated environment. Example 3 In Example 1, nylon 66 chop (tensile strength 7.0 g/denier, thickness 6 denier, tenacity 42.0 g, fiber length 6) was used instead of the vinylon chop.
mm) 100 parts by weight, and the amount of NBR added was 50 parts by weight.
A molding material was obtained in the same manner as in Example 1 except that the parts by weight were changed. The physical properties required for the power transmission material of the obtained molding material were as shown in Table 1. Example 4 In Example 1, vinylon chip-like cloth (tensile strength 7.8 g/
Denier, thickness 6 denier, strength 100 x 108Kg/25
Example 1 except that 40 parts by weight (mm width, 10 mm square) was blended, and CR75 parts by weight was blended instead of NBR.
A molding material was obtained in the same manner as above. The physical properties of the molding material obtained were as shown in Table 1. Example 5 A molding material was obtained in the same manner as in Example 1, except that the blended amount of vinylonchop was changed to 50 parts by weight and the blended amount of NBR was changed to 80 parts by weight. The physical properties of the molding material obtained were as shown in Table 1. Example 6 In Example 1, instead of vinyl chloride, it was washed with acetone in advance and then treated with caustic soda.
After boiling in a 40% aqueous solution for 2 hours, washing with water and drying, further forming the resorcinol resin-NBR rubber.
After soaking in 20% MEK solution, air dry, then 100%
Kevlar chip-shaped cloth (tensile strength: 22 g/denier, thickness: 1.4 denier, strength: 125 x 131 kg/25 mm width), obtained by drying the surface-treated Kevlar cloth obtained by drying at °C for 10 minutes and hardening with adhesive into 10 mm squares.
A molding material was obtained in the same manner as in Example 1, except that the amount of NBR was changed to 25 parts by weight. The physical properties of the molding material obtained were as shown in Table 1. Example 7 In place of the vinylon tip in Example 1,
A molding material was obtained in the same manner as in Example 1, except that 88 parts by weight of glass chops (tensile strength 11 g/denier, thickness 3 denier, tenacity 33 g, fiber length 3 mm) were blended. The physical properties of the molding material obtained were as shown in Table 1. Example 8 The sheet-like phenolic resin molding material obtained in Example 1 was cut into 30 cm width x 100 cm length, and while the sheet was still hot, it was immersed in a 20% MEK solution of resorcinol resin-NBR rubber. Vinylon cloth (tensile strength 7.8 g/denier, thickness 6 denier, strength 100 Sandwich 25 parts (108Kg/25mm width) and quickly transfer it to a cooling roll (25mm width).
℃/25℃) to obtain a sheet-like laminate. This sheet-like laminate was cut into appropriate sizes, compression molded by a conventional method, and various physical properties were measured.
The test results were as shown in Table 1.

[Table] Comparative Example 1 A molding material was obtained in the same manner as in Example 1, except that an unmodified novolak type phenolic resin was used instead of the modified phenolic resin.
The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 2 In Example 2, instead of the rayon cord,
Using rayon chops with tensile strength of 2g/denier, thickness of 2 denier, strength of 4g, and fiber length of 6mm,
A molding material was obtained in the same manner as in Example 2, except that 88 parts by weight of this material was blended. The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 3 A molding material was obtained in the same manner as in Example 3, except that the amount of nylon chips was changed to 150 parts by weight and the amount of NBR was changed to 100 parts by weight. The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 4 In Example 4, a vinylon chip with a tensile strength of 7.8 g/denier, a thickness of 6 denier, a tenacity of 46.8 g, and a fiber length of 6 mm was used instead of the vinylon chip cloth, and 10 parts by weight of this material was blended.
A molding material was obtained in the same manner as in Example 4. The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 5 A molding material was obtained in the same manner as in Example 5, except that the amount of NBR was changed to 125 parts by weight. The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 6 In Example 6, vinylon chips with a tensile strength of 7.8 g/denier, a thickness of 6 denier, a tenacity of 46.8 g, and a fiber length of 6 mm were used in place of the Kevlar chip-like cloth, and 100 parts by weight of this material was blended.
A molding material was obtained in the same manner as in Example 6, except that the amount of NBR was changed to 5 parts by weight. The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 7 Novolac-type phenolic resin 100 parts by weight Short glass fiber 200 Hexamethylenetetramine 15 Magnesium oxide 3 Stearic acid 3 The above formulation was uniformly dispersed and mixed with an appropriate amount of solvent in a Henschel mixer, and then heated on a hot roll ( 95℃/
Kneading was performed at 85° C. for 4 to 5 minutes to obtain a sheet-like phenolic resin molding material. The physical properties of the molding material obtained were as shown in Table 2. Comparative Example 8 A polyacetal resin was injection molded using a conventional method, and its physical properties were measured. The test results were as shown in Table 2.

【table】 [Brief explanation of drawings]

The figure is an explanatory diagram of a repeated impact test, and in the figure, reference numeral 1 is a test piece, 2 is a test piece support stand, 3 is a rotating blade, and 4 is a test piece striking part.

Claims (1)

[Claims] 1. (A) 100 parts by weight of a phenolic resin modified with at least one compound selected from cardol, anacardic acid and cardanol, (B) having a tensile strength of 6 g/denier or more. and (C) unvulcanized rubber or A phenolic resin molding material for power transmission materials containing 10 to 100 parts by weight of partially vulcanized rubber. 2. The phenolic resin contains at least one selected from cardol, anacardic acid, and cardanol in an amount of 10 to 100 parts by weight per 100 parts by weight of phenols.
The molding material according to claim 1, which is modified with a seed compound. 3. Claim No. 3 in which the organic fibrous base material is made of polyvinyl alcohol fiber, polyamide fiber, rayon fiber, hemp, surface-treated polyester fiber, surface-treated aramid fiber, or surface-treated carbon fiber. Molding material according to item 1 or 2. 4. The molding material according to any one of claims 1 to 3, wherein the unvulcanized rubber or partially vulcanized raw rubber consists of acrylonitrile butadiene rubber or chloroprene rubber. 5. The molding material according to any one of claims 1 to 4, wherein the twisted thread, the chip-like cloth, and the cloth are each hardened with an adhesive. 6. The molding material according to claim 5, wherein the adhesive is a rubber-modified resorcinol resin or a rubber-modified ammonia resol resin.