JP3201331B2 - Rubber reinforcing cord and its treating agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrogenated nitrile rubber (hereinafter referred to as H-NBR) excellent in flex resistance and heat resistance and a hydrogenated nitrile rubber in which zinc methacrylate is dispersed (hereinafter referred to as H-NBR). / ZDMA) for use in reinforcing a mixed rubber.

[0002]

2. Description of the Related Art In order to improve the strength and durability of rubber products such as rubber belts and rubber tires, it is widely practiced to embed glass fibers, chemical fibers and the like as reinforcing fibers in rubber.

However, since the reinforcing fibers themselves generally have poor affinity with rubber and have poor adhesiveness, when the surface of the reinforcing fibers is embedded in rubber without processing, the reinforcing fibers do not adhere to the rubber. Adhesion is weak and easily peels off during use. In such a state, the reinforcing fiber cannot satisfy the performance required as a reinforcing material for rubber products.

For this reason, when various reinforcing fibers are used in rubber products, it is common practice to form a coating layer on the surface of the reinforcing fibers to improve the familiarity with the rubber used and to improve the adhesiveness. ing.

For example, a glass fiber cord having a coating formed by applying a mixed treatment of a resorcinol-formalin condensate and H-NBR latex to a glass fiber and drying and curing the glass fiber (Japanese Patent Application Laid-Open No. 63-270877) is cited. Can be
Further, there has been proposed a rubber reinforcing fiber in which a second layer is coated with a halogen-containing polymer and isocyanate, and a third layer containing the same rubber as the matrix rubber is formed (Japanese Patent Publication No. 5-71710). However, the former is H-NB
Sufficient adhesive strength cannot be obtained with rubber mixed with R and H-NBR / ZDMA, and the latter requires three layers of coating, which complicates the manufacturing process and increases costs.

[0006]

As described above, formation of a coating layer on the surface of a reinforcing fiber is widely and generally performed in order to improve the adhesion between the rubber used and the reinforcing fiber. However, there are a wide variety of types of rubber and reinforcing fibers currently used, and if the types of rubber and reinforcing fibers are different, the types of coating layers for improving the adhesiveness are naturally different.

[0007] In recent years, H-NBR / ZDMA rubber has been receiving attention in various fields. The rubber obtained by mixing H-NBR / ZDMA rubber with H-NBR rubber has higher heat resistance than the conventionally used H-NBR rubber, and is used in a field where it could not be used conventionally, or compared with a conventional product. Can be used as a higher performance alternative.

[0008] The present invention relates to H-NBR and H-NBR / ZD.
In the case where a reinforcing fiber is used for rubber containing MA as a main component, a reinforcing cord having improved adhesion to the rubber and a coating layer of the reinforcing cord (the surface serving as the second layer on the reinforcing fiber) The purpose of the present invention is to obtain a treatment agent for forming a treatment film).

[0009]

According to a first aspect of the present invention, there is provided a rubber reinforcing cord according to the present invention, wherein the rubber reinforcing fiber comprises a resorcinol-formalin condensate and a rubber latex. Is applied and dried and cured to form a first coating layer, and further a different treatment agent is applied on the first coating layer, dried and cured to form a second reinforcing layer. Treatment agent for
It is mainly composed of a rubber compound, a vulcanizing agent and a dimethacrylate vulcanizing aid.

[0010] The rubber reinforcing cord according to the second aspect of the present invention is the cord according to the first aspect, wherein the vulcanization aid contained in the treating agent for the second coating layer is 1,3-butylene glycol dimethacrylate. There is something.

The rubber reinforcing cord according to the third aspect of the present invention is the rubber reinforcing cord according to the first aspect, wherein the vulcanization aid contained in the treatment agent for the second coating layer is 2-hydroxy-1,3-diene. It is methacryloxypropane.

[0012] The rubber reinforcing cord according to the fourth aspect of the present invention is the rubber reinforcing cord according to the first aspect, wherein the vulcanization aid of the second coating layer treating agent is 2,2-bis (4- (methacryloxy. Diethoxy) phenyl) propane.

According to a fifth aspect of the present invention, there is provided the rubber reinforcing cord according to any one of the first to fourth aspects, wherein the rubber compound of the treating agent for the second coating layer comprises a hydrogenated nitrile rubber. It is a melt of a mixed rubber consisting of hydrogenated nitrile rubber in which zinc methacrylate is dispersed.

[0014] The treating agent of the invention according to claim 6 is the treating agent for the second coating layer according to any one of claims 1 to 5.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a rubber compound, a rubber compound, By using a coating layer treating agent containing a sulfurizing agent and a dimethacrylate vulcanization aid, H-NBR and H-N
It has been found that the adhesion between a rubber containing BR / ZDMA as a main component and a reinforcing cord can be dramatically improved. Hereinafter, embodiments of the present invention will be described in detail.

The rubber reinforcing fiber used in the present invention is not limited, and specific examples thereof include glass fiber, polyvinyl alcohol fiber represented by vinylon fiber, polyester fiber, nylon, and polyamide fiber such as aramid (aromatic polyamide). , Carbon fiber, polyparaphenylene benzoxazole fiber and the like. Among these, glass fibers and aramid fibers are preferably used. The type of glass fiber is not particularly limited, and non-alkali glass, high-strength glass, and the like can be used.
The filament diameter of the glass fiber is not particularly limited, but those having a diameter of 5 to 13 μm are generally used. As the aramid fiber, those having a denier of 500 to 5,000 are generally used. Examples of the form of these fibers include stable, filament, cord, rope, and canvas.

The rubber latex for forming the first coating layer according to claim 1 is specifically a butadiene / styrene copolymer latex, a dicarboxylated butadiene / styrene copolymer latex, a vinylpyridine / butadiene / styrene. Terpolymer latex, chloroprene latex, butadiene rubber latex, chlorosulfonated polyethylene latex, acrylonitrile / butadiene copolymer latex, and nitrile group-containing highly saturated copolymer rubber latex are preferred.

As the rubber compound contained in the treating agent for the second coating layer, various rubber compounds may be used depending on the type of the matrix rubber.
Alternatively, a plurality of mixed rubbers can be used. The type of rubber and its solvent are not limited. Examples of rubber include chloroprene rubber, chlorosulfonated polyethylene, H
-NBR or H-NBR / ZDMA or the like is used. These rubbers are selected depending on the type of the matrix rubber in consideration of the compatibility and the like. In particular, when the matrix rubber is a mixed rubber composed of H-NBR and H-NBR / ZDMA, the treatment for the second coating layer is performed. As the rubber compound of the agent, one obtained by dissolving the same rubber is suitably used.

H-NBR and H-NBR / ZD to be dissolved
The weight ratio to MA is H-NBR / (H-NBR / ZDM).
A) = 45 to 80/55 to 20, preferably H-NBR
If the ratio of / ZDMA is small, sufficient adhesive strength cannot be obtained, and if the ratio is large, the cord becomes hard and the bending fatigue property deteriorates.

The H-NBR must have an iodine value of 120 or less from the viewpoints of rubber film strength and adhesion to the matrix rubber, and preferably has an iodine value of 0 to 100. Zetpol (trade name, manufactured by Zeon Corporation) can be suitably used as this rubber. The iodine value is a value determined according to JIS K0070.

As the H-NBR / ZDMA used in the present invention, ZSC (trade name, manufactured by Nippon Zeon Co., Ltd.) in which polyzinc methacrylate is dispersed in the above-mentioned zetpol can be suitably used.

The solvent for dissolving the rubber is benzene,
An aromatic hydrocarbon such as toluene or xylene, a halogenated hydrocarbon such as trichloroethylene, methyl ethyl ketone (hereinafter referred to as MEK), ethyl acetate, or the like is used. In the case of a compounded rubber such as H-NBR, MEK is usually used.

The vulcanizing agent contained in the treating agent for the second coating layer may be an organic peroxide such as sulfur, dicumyl peroxide, 1,3-bis (t-butylperoxy-isopropyl) benzene, or p-diphenyl. Aromatic nitroso compounds such as nitrosonaphthalene and p-dinitrosobenzene are exemplified. Many of these are preliminarily compounded in the rubber compound, and are therefore added when necessary.

The type of the dimethacrylate vulcanization aid is not particularly limited, and specific examples thereof include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 3-
Butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane,
2,2-bis (4- (methacryloxydiethoxy) phenyl) propane or 2,2-bis (4- (methacryloxy.
(Polyethoxy) phenyl) and the like can be used.

In particular, 1,3-butylene glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane and 2,2-bis (4- (methacryloxydiethoxy) phenyl) propane are used as a means for improving adhesion. Can be suitably used.

The compounding ratio of the coating layer treating agent is as follows:
Vulcanizing agent / dimethacrylate vulcanizing aid = 100 / 0-1
0/1 to 150 parts by weight, and 100/0 to 6/30 to
It can be suitably used in the range of 80 parts by weight.

The treating agent for the second coating layer of the present invention may contain an inorganic filler such as carbon black, a plasticizer, an antioxidant or a crosslinking assistant.

The glass fiber treating agent for the second coating layer of the present invention is usually prepared as a solution or dispersion having a solid content of 3 to 25% by weight, more preferably 5 to 15% by weight.

The method for forming the second coating layer is not particularly limited, but usually, the rubber reinforcing fiber provided with the primary coating layer is immersed in a solvent tank containing a treating agent, and then dipped in a drying oven. , Forming a coating layer. The drying conditions are not limited, but the drying is generally performed at 80 to 160 ° C. for 0.1 to 1 minute.
The adhesion rate is 1 to 10%, preferably 3 to 7%.

[0030]

[Example 1] Glass fiber (E-glass; 9μ)
The three glass filaments having a diameter of 200 m were bundled together and coated with a first coating layer treating agent having the following composition by a known method.

[0031]

[Table 1] ---------------------------------------------- ------------------------ Composition Blending ratio (parts by weight) ---------------------- −−−−−−−−−−−−−− Vinylpyridine latex (solid content 40%) 45 Chlorosulfonated polyethylene latex (solid content 40%) 20 Resorcin-formalin condensate (solid content 8%) 30 (Resorcinol / formalin = 1 / 1.3 molar ratio) 25% ammonia water 1 water 4 ------------------------------ ----------------------------------------

The glass fiber on which the first coating layer is formed is 8
After the twist / 10 cm priming, 11 strands are aligned and further 8 times / 10 cm twisted, and then the second coating layer treating agent is applied and dried and cured in the same manner as described above. It was a fiber cord.

[0033]

[Table 2] ---------------------------------------------- ---------- Composition of treatment agent for coating layer Compounding ratio (parts by weight) ---------------------------------------------------------------------- -Rubber composition 100 toluene 416 methyl ethyl ketone 180 1,3-butylene glycol dimethacrylate 50 -------------------------------- ------------------------

The second coating layer was 5% by weight based on the weight of the glass fiber cord. Table 3 below shows the rubber compositions in Table 2 above.

[0035]

[Table 3] ---------------------------------------------- -------- Composition of rubber composition Compounding ratio (parts by weight) ------------------------------------------------------------------------ ) 70 ZSC2000L (* 2) 30 ZnO 10 Stearic acid 1 Carbon black 30 TOTM (Trioctyl Trimellitate) 5 Sulfur 0.1 1,3-Bis- (t-butylperoxy-isopropyl) -benzene 6 -------- ---------------------------------------------- (* 1) Trade name H-NBR: manufactured by Zeon Corporation (* 2) Trade name H-NBR / ZDMA: manufactured by Zeon Corporation

In order to test the adhesion between the glass fiber cord and the mixed rubber composed of H-NBR and H-NBR / ZDMA, a test piece having a composition shown in Table 3 (width 25 mm × length 50 mm × thickness 5 mm) The glass fiber cords were arranged on the upper side along the long side, and bonded by heating at 160 ° C. for 30 minutes.

The test piece after the heat bonding was placed in a tensile tester, pulled in the fiber direction, and its strength value was measured.
The results are shown in Table 5 below.

Example 2 The processing agent for the second coating layer used in Example 1 was changed from 1,3-butylene glycol dimethacrylate to 2-hydroxy-1,3-dimethacryloxypropane. did. Others were exactly the same as Example 1.

Example 3 The treatment agent for the second coating layer used in Example 1, 1,3-butylene glycol dimethacrylate, was added to 2,2-bis (4- (methacryloxy diethoxy) phenyl) propane. changed. Others were exactly the same as Example 1.

Example 4 An aramid fiber (Technola T202: 1500d manufactured by Teijin Limited) was used in place of the glass fiber used in Example 1, and the same treating agent for the first coating layer as in Example 1 was applied. Thereafter, the solid adhered rate was adjusted to 12%, and heat treatment was performed at 250 ° C. for 1 minute. This was plied twice and subjected to 3.1 times of twist per inch to obtain an aramid fiber cord. Using the aramid fiber cord thus obtained, a treatment was performed using the same treating agent for the second coating layer as in Example 1. The second coating layer was 10% by weight based on the weight of the aramid fiber cord. The evaluation method of the adhesiveness was the same as in Example 1.

Comparative Example 1 The second example used in Example 1 was used.
The second coating layer was formed using the processing agents shown in Table 4 below in place of the coating layer processing agents (described in Table 2). Other than that, the test was performed under the same conditions as in the example.

[0042]

[Table 4] -------------------------------------- Composition Mixing ratio (parts by weight)- −−−−−−−−−−−−−−−−−−− Rubber composition 100 Toluene 416 Methyl ethyl ketone 180 ------------------------ --------------

[Comparative Example 2] A second coating layer was formed by using the treating agent shown in Table 4 used in Comparative Example 1 instead of the treating agent for the second coating layer used in Example 4. Others
The test was performed under the same conditions as in Example 4.

[0044]

[Table 5]

[0045]

According to the present invention, H is excellent in bending resistance and heat resistance.
Dramatically improving the adhesion between the compounded rubber comprising -NBR and H-NBR / ZDMA and the glass fiber, and using the glass fiber cord according to the present invention makes it possible to use it in a high temperature environment, In addition, it is possible to obtain an H-NBR rubber product having significantly improved durability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI // C08J 5/04 CEQ C08J 5/04 CEQ

Claims (6)

(57) [Claims] 1. A treatment agent containing a resorcinol-formalin condensate and rubber latex is applied to a rubber reinforcing fiber, dried and cured to form a first coating layer, and a different treatment agent is further applied on the first coating layer. In a fiber cord for reinforcing rubber having a second coating layer formed by drying and curing, the treatment agent for the second coating layer mainly comprises a rubber compound, a vulcanizing agent and a dimethacrylate vulcanization aid. A cord for rubber reinforcement, characterized in that: 2. The rubber reinforcing cord according to claim 1, wherein the vulcanization aid contained in the second coating layer treating agent is 1,3-butylene glycol dimethacrylate. 3. The rubber reinforcing cord according to claim 1, wherein the vulcanization aid contained in the second coating layer treating agent is 2-hydroxy-1,3-dimethacryloxypropane. 4. The rubber reinforcing cord according to claim 1, wherein the vulcanization aid contained in the second coating layer treating agent is 2,2-bis (4- (methacryloxydiethoxy) phenyl) propane. 5. The rubber compound contained in the second coating layer treating agent is a melt of a mixed rubber comprising a hydrogenated nitrile rubber and a hydrogenated nitrile rubber in which zinc methacrylate is dispersed. 5. The rubber reinforcing cord according to any one of items 4 to 4. 6. The treating agent for a second coating layer according to claim 1, wherein