JPH072898B2 - Phenol resin molding material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel phenol resin molding material, and more particularly to a phenol resin molding material suitable for molding a sliding material, a power transmission material, or the like. .

Conventional technology Conventionally, sliding materials such as bearings, bearing bushes, rollers and sleeves, gears, cams, chains, belts, pulleys,
As a molding material used for a power transmission material such as a stator or an impeller, for example, a polyacetal resin, a glass fiber reinforced polyamide resin, a modified polyamide resin, or a glass fiber-based phenol resin molding material is known. ing.

By the way, molding materials used for such sliding materials and power transmission materials generally have (1) high impact strength and bending strength, and (2) sufficient resistance to repeated impact strength. Physical properties such as (3) high wear resistance and moderately small frictional force, (4) high heat resistance, and (5) moderately low flexural modulus are required.

However, some of the above physical properties are contradictory, such as the relationship between bending strength and impact strength, so it is virtually impossible to satisfy all of these physical properties at a high level at the same time. The current situation is that no material is found.

For example, since the polyacetal resin is a thermoplastic resin, it has low heat resistance, and has a drawback that the surface melts or creeps when rotated at a high speed, and further,
Although the bending strength and the impact strength are well balanced, the values of both are low.

Although glass fiber reinforced polyamide resin and modified polyamide resin are reinforced with glass fiber, since the base material is a thermoplastic resin, the surface melts at high temperature or high speed, causing slippage or creep. Inevitably, it has a drawback in that it has a high bending elastic modulus, which causes an unpleasant frictional noise during use to cause noise.

On the other hand, in the phenolic resin molding material of the glass fiber base material, although the bending strength is extremely high, the elongation of the material is extremely small, so the impact strength is as low as about 2 to 5 kg · cm / cm, and the glass fiber is Since it cannot cope with the elongation of the material, it cannot sufficiently withstand repeated impacts, and when it is used as a power transmission material, it has a drawback that noise is generated during rotation.

The present inventors have previously prepared a modified phenolic resin, which has a tensile strength of 6 g / denier or more, and a blending of a non-vulcanized or partially vulcanized rubber with a fibrous base material having a strength of 12 g or more. We have developed a phenol resin molding material for transmission materials (Japanese Patent Laid-Open No. 62-54754), but this molding material has high impact strength and bending strength, is sufficiently resistant to repeated impact, and has excellent heat resistance and flexural elasticity. Although it exhibits suitable physical properties as a power transmission material that the rate is low, it produces an unpleasant friction noise during use,
The drawback of causing noise was not remedied.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention overcomes the drawbacks of the prior art,
High impact strength and bending strength, sufficient resistance to repeated impacts, excellent heat resistance, and low flexural modulus at the same time satisfy the contradictory characteristics and can sufficiently eliminate fricative noise. The purpose of the present invention is to provide a phenolic resin molding material that is well-balanced in physical properties at such a high level and is suitable for use as a sliding material or a power transmission material.

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to develop a phenolic resin molding material with well-balanced physical properties required for sliding materials, power transmission materials, and the like. As a result, it has been found that the above object can be achieved by blending a phenolic resin with a rubber component, a fibrous base material having a specific tensile strength and strength, and a friction modifier at a predetermined ratio and uniformly dispersing them. The present invention has been completed based on this finding.

That is, according to the present invention, (A) 100 parts by weight of a matrix containing 3 to 70 parts by weight of a rubber component per 100 parts by weight of a phenolic resin, (B) has a tensile strength of 6 g / denier or more and has a tensile strength of 12 g or more. The present invention provides a phenolic resin molding material obtained by mixing 10 to 125 parts by weight of a fibrous base material having strength and 1 to 70 parts by weight of a friction modifier (C).

Hereinafter, the present invention will be described in detail.

In the molding material of the present invention, examples of the phenolic resin constituting the component (A) include modified or unmodified type novolak type, resol type or benzylic ether type phenolic resin. As the modified phenol resin, for example, an alkyl-modified phenol resin or tall oil-modified phenol resin can be used, and particularly preferable ones are cardol, anacardic acid and cardanol (hereinafter, cardol) contained in cashew oil. And a phenol resin modified with at least one member selected from the above.
Such a phenolic resin has a strong adhesive force and excellent compatibility with the rubber component added to it, so that in the blend with the rubber component, a strongly bonded micro sea-island structure is formed. Therefore, a molding material in which both impact strength and bending strength are balanced at high values is obtained.

When modified with the above cardol alone or in combination,
It is preferable to use 10 to 100 parts by weight of cardol, preferably 15 to 70 parts by weight, based on 100 parts by weight of phenols such as phenol, cresol and resorcin. When the amount of modification is less than 10 parts by weight, the compatibility with the rubber component is poor, and the bending strength and impact strength of the molding material are low, which is not preferable. On the other hand, when the amount exceeds 100 parts by weight, the bending strength of the molding material decreases, and However, the heat resistance also deteriorates.

The modified and unmodified phenolic resins described above can be used alone or in combination of two or more kinds, and particularly when the unmodified phenolic resin and the modified phenolic resin such as cardol are used together, the compatibility with the rubber component to be added. Considering the above, it is desirable to appropriately select the mixing ratio of both.

The rubber component that forms a matrix with the phenol resin is mixed in an amount of 3 to 70 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the phenol resin. If the compounding ratio of this rubber component is less than 3 parts by weight, the impact strength of the resulting molding material will not be sufficiently improved, while if it exceeds 70 parts by weight, the bending strength at high temperature will be greatly reduced and the heat-resistant creep resistance will be poor. Become.

As the rubber component, unvulcanized or vulcanized acrylonitrile-butadiene rubber (NBR), carboxy-modified acrylonitrile-butadiene rubber (C-NBR), chloroprene rubber (CR), acrylic rubber, chlorinated rubber, etc. Highly polar rubbers are suitable and these can be used alone or in combination. Also, this rubber component is sulfur,
By adding a vulcanizing agent such as a peroxide or a resin vulcanizing agent, a vulcanization accelerator, and a vulcanization aid, crosslinking may be performed during the kneading and curing process of the phenol resin. A phenol resin molded product containing such a crosslinked rubber component is characterized in that it can be suitably used even in a heating environment.

Among the rubber components, the carboxyl-modified acrylonitrile-butadiene rubber (C-NBR) is particularly excellent in compatibility with the phenol resin, and since the rubber is uniformly dispersed in the resin, high strength can be given. By using this C-NBR, it is possible to increase the usage rate of the unmodified phenol resin in the case where the modified phenol resin and the unmodified phenol resin are used in combination, and the unmodified phenol resin alone is also used. It will be possible.

In the molding material of the present invention, the fibrous base material used as the component (B) must have a tensile strength of 6 g / denier or more and a strength of 12 g or more, preferably 30 g or more. A fibrous base material which does not satisfy such conditions, for example, having a strength of 12 g or more, but having a tensile strength of less than 6 g / denier (for example, a tensile strength of 2 to 3 g / denier, a strength of 12 g.
The rayon chipped strand (hereinafter abbreviated as rayon chip) is insufficient in improving impact strength and bending strength, and has a tensile strength of less than 6 g / denier and a strength of less than 12 g. However, the impact strength and bending strength are low, and the object of the present invention is not achieved. The shape of the fibrous base material is not particularly limited, and for example, fibers, twisted yarns, chip-like cloths, cloths and the like may be used alone or in combination of two or more kinds.

As mentioned above, the essential requirement for the fibrous base material used to reinforce the rubber-phenolic resin matrix is not to satisfy the Young's modulus of the fiber or the tensile strength alone, but to satisfy both the tensile strength and the strength. is there. This is because even if fibers having the same tensile strength are used in the same weight part with respect to the resin, the impact strength is remarkably improved only by increasing the fiber diameter to increase the strength, or the strength such as cotton chips is great. Nevertheless, it is also clear from the fact that the effect of improving impact strength is extremely small because the tensile strength is small.

The tensile strength here is the strength against a certain thickness, and is expressed by the load per unit area, and the unit is common to fibers, twisted yarns, chip-like cloths, and g / of single fiber. Shown in denier. The term “strong” simply means the strength itself without considering the thickness, and is a load obtained by multiplying the tensile strength by the thickness (denier), and the unit is g.

Examples of the fibrous base material used in the present invention include polyvinyl alcohol fibers (hereinafter abbreviated as vinylon fibers), polyamide fibers (hereinafter abbreviated as nylon fibers), rayon fibers, cellulosics such as ramie, flax, and hemp. Fibers, polyester fibers, and organic fibers such as aramid fibers are preferable, and these may be used alone or in combination of two or more kinds. Also,
As the fibrous base material, carbon fiber, glass fiber, metal fiber,
When using inorganic fibers such as mineral fibers, it is preferable to use in combination with the above-mentioned organic fibers. When such inorganic fibers are used alone, for example, when used in a V-belt block, the pulley surface is damaged, Since the specific gravity is large, the block becomes heavy to generate a large centrifugal force, and the friction coefficient with the surface of the pulley is too large, which causes a large friction noise. In this case, the amount of the inorganic fibers used is 70% by weight or less, preferably 50% by weight or less, based on the total fibers. Further, among the above-mentioned various fibers, rayon fiber, hemp such as flax, cannabis, aramid fiber, or carbon fiber or glass fiber used together has a small temperature dependence of elastic modulus even at high temperature, and fiber composed of the fiber. The phenol-based resin molding material obtained by blending a quality base material is particularly preferable because it has little deterioration in physical properties such as bending strength even at high temperatures and can be sufficiently used even in a heating environment.

Furthermore, among the aramid fibers, the formulaAnd the formula unitAnd a structural unit represented by
What you have [Technora Manufactured by Teijin Ltd.]
When used as a material, it can be used as a molding material during manufacturing and molding.
Since the cutting rate of the fiber is low, high impact strength can be obtained,
Therefore, the flexural modulus at high temperature was further improved.
In order to reduce the rubber compounding ratio,
When used alone or in combination, particularly good results are obtained and
It will be good.

As the fibrous base material, when glass fiber is used, it is desirable to use it after surface-treating it with a silane coupling agent, etc., and also aramid fiber, polyester fiber,
When carbon fibers or the like are used, since they have poor reactivity with resins, it is desirable to use them after pretreatment by a known method and then surface-treating with resorcinol resin, resole-type phenol resin, epoxy resin or the like. . Further, this fibrous base material, as described above, fibers, twisted yarn,
It is used in the form of a chip-shaped cloth, cloth, etc., and the fiber length thereof is not particularly limited, but a range of 1 to 10 mm is preferable. The twisted yarn, the chip-shaped cloth, the cloth, etc. may be used as they are, but it is preferable to use them after they are hardened with an adhesive.

The blending ratio of this fibrous base material in the molding material of the present invention is
To 100 parts by weight of the matrix (A), 10
˜125 parts by weight, preferably 20 to 80 parts by weight. If the amount is less than 10 parts by weight, the improvement of impact strength and bending strength is insufficient, and if it exceeds 125 parts by weight, molding becomes difficult and it is not suitable for practical use.

Examples of the friction modifier used as the component (c) in the molding material of the present invention include fluorine-based resins such as polytetrafluoroethylene (hereinafter abbreviated as PTFE), perfluoroalkoxytetrafluoroethylene, graphite, and disulfide. Examples thereof include molybdenum and carbon whiskers. Among these, fluorine-based resins are suitable and used in a powder state. These friction modifiers may be used alone or in combination of two or more.

It is considered that the friction modifier has the effects of lowering the coefficient of static friction, not significantly lowering the coefficient of dynamic friction, improving the sliding characteristics without impairing the power transmission ability, and lowering noise.

The blending ratio of the friction modifier in the molding material of the present invention is
It is selected in the range of 1 to 70 parts by weight, preferably 3 to 40 parts by weight, relative to 100 parts by weight of the matrix (A). If the mixing ratio is less than 1 part by weight, frictional noise cannot be erased and sufficient slidability cannot be obtained. On the other hand, if it exceeds 70 parts by weight, the strength and friction coefficient are lowered, and when used as a power transmission material, the transmission is reduced. This is not preferable because it lowers the capacity and further increases the cost of the molding material.

In the molding material of the present invention, in addition to the above-mentioned essential components, various additives such as calcium carbonate for improving wear resistance, isotropic shrinkage, moldability, etc., if necessary, within a range not impairing the object of the present invention. , Silica, talc, clay, wollastonite, inorganic powder such as potassium titanate, hardener,
A curing catalyst, a release agent, etc. can be added.

The phenol-based resin molding material of the present invention is a commonly used method, for example, a phenol-based resin, a rubber component, a fibrous base material, a friction modifier and various additives to be added if necessary, each in a predetermined ratio. After mixing and uniformly dispersing and mixing this with a Henschel mixer or the like, after kneading with a hot roll, it is made into a sheet, and then this sheet material is crushed, crushed, or granulated to obtain a moldable material. It can be manufactured by any method.

There is no particular limitation on the molding method of the phenol resin molding material thus obtained, and any method can be used from among conventionally used methods.

In order to crosslink the rubber component, it is sufficient to add an appropriate amount of a crosslinking agent and a crosslinking accelerator to the unvulcanized rubber, knead with a roll, and then mix this with a molding material.

The thus-obtained phenolic resin molding material of the present invention, the rigid phenolic resin, the unvulcanized rubber or partially vulcanized rubber and a large fiber base material of tensile strength and strength The friction modifier and the friction modifier are evenly dispersed and bonded with a strong adhesive force.

Here, the adhesive strength will be described. When the adhesive strength is weak, even if the degree of fiber reinforcement is increased, the impact strength is improved, but the bending strength is decreased, and the unvulcanized rubber or a part thereof is used. Vulcanized rubber, that is, even if the impact strength is increased by increasing the rubber component, the bending strength is also remarkably reduced. Therefore, it is an essential requirement to increase the adhesive strength between the rubber component and the phenol resin. I found out.

Explaining the strong adhesive force between the fibrous base material and the phenol resin, vinylon fiber, nylon fiber, rayon fiber, hemp and the like are partially mixed during kneading and mostly during molding. Resin and its surface react with each other to form a strong chemical bond, glass fiber is treated with a silane coupling agent, and polyester fiber, aramid fiber and carbon fiber are pretreated, and then surface treated with the adhesive. Therefore, since the object of the present invention can be achieved only when the fibrous base is bonded to the phenolic resin with a strong adhesive force, it is also an essential requirement that the fibrous base material is bonded to the phenolic resin with a strong adhesive force. I found out that The strong bonding force between the fibrous base material and the phenol resin is effective for repeatedly increasing the impact strength.

From these facts, the molded product obtained has improved impact strength and repeated impact strength.

In addition, the fibrous base material made of rayon fiber, hemp, surface-treated aramid fiber, or glass fiber and partially vulcanized rubber have a small temperature dependence of elastic modulus even at high temperature, and particularly flexural strength and flexural elasticity. It is effective in suppressing the deterioration of physical properties such as rate at high temperature.

Furthermore, by using the twisted yarn, the chip-shaped cloth and the cloth after being hardened with an adhesive, it is possible to prevent the twisted yarn, the chip-shaped cloth and the cloth from unraveling during the material production, and to prevent these fibers from extending in the longitudinal and transverse directions. Improves tensile strength and cooperation.

Further, the addition of the friction modifier has the effects of lowering the static friction coefficient, improving the sliding characteristics without lowering the dynamic friction coefficient and impairing the power transmission ability, and further reducing noise.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The physical properties of the phenol resin molding material were measured according to the methods described below.

(1) Impact strength, flexural strength and flexural modulus According to JIS K6911. Here, the impact strength is the Izod impact strength with a notch, and the test piece used is one provided with a notch at the time of molding by a mold.

The bending strength and elastic modulus were measured using a 10 mm square rod under the conditions of a fulcrum distance of 64 mm and a load speed of 2 mm / min.

(2) Dynamic friction coefficient and wear coefficient It was measured under the following conditions using a journal tester.

a) Test piece shape and dimensions Cylindrical molded product with inner diameter 8φ, outer diameter 12φ, length 8mm b) Test condition load 2.5kgf Linear velocity 20m / min Mating material SUS304 Clearance 60-70μm Temperature 80 ± 3 ℃ Sliding time 2hr. In addition, the transmission capacity test, belt durability test and noise test were performed under the following belt specifications and test conditions.

(A) V-belt dimensions V-block thickness 4.8 mm Upper width 45 mm, angle 26 ° Mounting pitch 5.0 mm V-belt circumference 750 mm (V-blocks: 150 pieces) V-blocks are reinforcement members made of 2 mm thick aluminum alloy Is insert molded.

(B) V-belt transmission capacity test Wrap a sample V-belt between a drive pulley (pitch diameter 70 mm) and a driven pulley (pitch diameter 160 mm), and transfer torque at a drive pulley rotation speed of 2500 rpm and an axial load of 250 kg. Change
The slip rate was measured. From the transmission torque when the slip ratio was 2%, the ST value was calculated using the following formula, and this was taken as the transmission capacity.

ST = T / r.rθ T: Transmission torque at 2% slip (kgm) r: Effective radius (m) θ: Belt wrap angle (radian) (C) V-belt durability test Same as transmission capability test Drive pulley rotation speed 2500r.pm, shaft load 250kg, input torque 4.5kg
・ M, tested at an ambient temperature of 90 ° C when the belt was running.

(D) V-belt noise test Same layout as the transmission capacity test, drive pulley rotation speed
The total noise level was measured with a sound level meter 24 at a predetermined position (L ₁ = 50 mm, L ₂ = 100 mm) while traveling at 1000 rpm, an axial load of 100 kg, and no load.

Production example Production of modified phenol resin 100 parts by weight 92% by weight paraformaldehyde 87 parts by weight Cascade oil (Kardalite D-10, made by Ito Essential Oil) 40 parts by weight Citric acid 0.5 parts by weight All the above raw materials are thermometer, stirrer and condenser The contents were heated to 120 ° C. to completely dissolve them, and then the condensation reaction was carried out at 100 ° C. for 3 hours under reflux. Next, the temperature was raised to 200 ° C. under normal pressure for dehydration, and then the contents were taken out from the flask and cooled to obtain a cashew-modified phenol resin. The softening point of the obtained resin is 60 ° C, and the flow at 10% hexa is 67 mm / 125.
The gel time was 40 seconds / 150 ° C. This resin is the resin A
And

Example 1 Modified phenolic resin (Resin A) 67 parts by weight Hexamethylenetetramine 10 parts by weight NBR (Nitpol 1041 manufactured by Zeon Corporation) 23 parts by weight Calcium carbonate 7.5 parts by weight Calcium stearate 2 parts by weight Vinylon tip (tensile strength 7.8 g / denier, strong) 46.8g
Fiber length 6 mm) 20 parts by weight Aramid fiber (Teijin Co., Ltd. Technora Tensile strength 25 g /
Denier tenacity 37 g, fiber length 3 mm) 18 parts by weight PTFE powder 7.5 parts by weight The above compound is uniformly dispersed and mixed with an appropriate amount of solvent in a Henschel mixer, and heated on a hot roll (95 ° C / 85 ° C) for 4-5
The mixture was kneaded for a minute and formed into a sheet and taken out. This sheet material was cut into an appropriate size to obtain a moldable phenol resin molding material.

A test piece for testing was prepared by transfer molding of the molding material by an ordinary method, and the impact strength, bending strength, flexural modulus, dynamic friction coefficient and wear coefficient were measured. The results are shown in Table 1.

Examples 2 to 5 Molding materials were prepared in the same proportions as in Example 1 with the compounding ratios shown in Table 1, and the same physical properties were measured after molding the test piece. The results are shown in Table 1.

The raw materials Technora (manufactured by Teijin Limited) were each surface-treated with an epoxy resin.

Comparative Example 1 Using a polyacetal resin (manufactured by Diuracon M-90 ... Polyplastics Co., Ltd.), the dynamic friction coefficient and the wear coefficient were measured in the same manner as in Examples 1-5. The results are shown in Table 1. The other physical properties are described with reference to the catalog values.

Examples 6 to 9 Molding materials were prepared in the same proportions as in Example 1 with the compounding ratios shown in Table 2, and after the test piece molding, impact strength, bending strength,
The flexural modulus was measured and each performance test was performed using a V-belt. The results are shown in Table 2.

Comparative Examples 2-5 With the compounding ratios shown in Table 3, a molding material was prepared in the same manner as in Example 1, and each performance test was performed after molding the test piece (Comparative Examples 2-4). Further, each performance test was similarly performed on the glass fiber reinforced aromatic polyamide resin (Comparative Example 5). The results are shown in Table 3.

In addition, V for the glass fiber reinforced aromatic polyamide resin (Lenny 1022, manufactured by Mitsubishi Gas Chemical Co., Inc.) of Comparative Example 5
The V-block used for the belt was injection-molded by a conventional method using a thermoplastic resin injection molding machine.

Further, a glass fiber silane coupling agent whose surface was treated with a silane coupling agent was used.

EFFECTS OF THE INVENTION As described above, the phenol resin molding material of the present invention has originally high contradictory properties such as high impact strength and bending strength, sufficient resistance to repeated impact, and excellent heat resistance. Since it has both of the above properties, the physical properties are well balanced and the coefficient of friction is small, it can be suitably used as a sliding material or a power transmission material.

For example, as shown in the examples, when a cylindrical molded product is formed from the phenolic resin molding material of the present invention and used as a sliding bearing, the bearing is damaged at high temperature or under high load or melts on the bearing surface. It is a sliding bearing that has excellent mechanical strength and heat resistance without the occurrence of such problems.

Similarly, when a V-block is similarly formed to form a V-belt as a power transmission material, the V-belt is free from melting of the V-block surface during high-temperature high-speed operation and damage to the V-block due to impact during V-belt rotation. It is a long-life belt that can withstand high speed, high temperature and heavy load. Furthermore, since a friction modifier is used, a V-belt with reduced noise is obtained due to its sliding effect.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location C08L 21:00) (72) Kenji Nishida Kenji Nishida 3-2-15 Meiwadori, Kobe, Hyogo Prefecture No. Bandou Kagaku Co., Ltd. (72) Inventor Keizo Nonaka 3-2-15 Meiwadori, Hyogo-ku, Kobe, Hyogo Prefecture Bando Kagaku Co., Ltd. (56) Reference JP-A-62-54754 (JP, A)

Claims (8)

[Claims] 1. A binder having a tensile strength of 6 g / denier or more and 12 g with respect to 100 parts by weight of a matrix containing 3 to 70 parts by weight of a rubber component per 100 parts by weight of a phenolic resin (A).
10 to 125 parts by weight of a fibrous base material having the above strength and (C)
A phenolic resin molding material prepared by mixing 1 to 70 parts by weight of a friction modifier. 2. The phenolic resin is a phenolic resin modified with at least one selected from cardol, anacardic acid and cardanol.
The molding material according to the item. 3. The rubber component is at least one selected from chloroprene rubber, acrylonitrile-butadiene rubber and carboxy-modified acrylonitrile-butadiene rubber.
The molding material according to claim 1 or 2, which is a seed. 4. The method according to any one of claims 1 to 3, wherein the fibrous base material is a combination of an organic fiber or an inorganic fiber containing 70% by weight or less of an organic fiber or an inorganic fiber. The molding material described. 5. The molding material according to claim 4, wherein the organic fiber is at least one selected from polyvinyl alcohol fiber, polyamide fiber, cellulosic fiber, polyester fiber and aramid fiber. 6. The aramid fiber has the formula And the formula unit 6. The molding material according to claim 5, which contains the structural unit represented by the formula (1) at a molar ratio of substantially 1: 1. 7. The molding material according to claim 4, wherein the inorganic fiber is at least one selected from carbon fiber, glass fiber, metal fiber and mineral fiber. 8. The molding material according to any one of claims 1 to 7, wherein the friction modifier is a fluororesin powder or graphite powder.