JPH0560490B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a method of adhering a rubber composition and brass in the production of rubber/metal composite products used in fields requiring heat resistance and oil resistance. It can be used to bond products such as tires, belts, molds, rolls, and hoses. Prior Art In recent years, many rubber products such as tires, belts, molds, rolls, and hoses have been used for long periods of time with heated oil under high temperature and pressure, and rubber products deteriorate under such conditions. is always a serious issue. If rubber products are severely deteriorated, maintenance or replacement requires a great deal of time and effort, and can sometimes lead to major accidents. It has excellent oil resistance and can withstand such high temperatures (120℃~150℃).
Polymers that can withstand continuous use under ℃) environment include acrylonitrile-butadiene copolymer rubber (NBR), acrylic rubber (ACM), ethylene acrylic rubber (AEM); ethylene-acrylic-vinyl acetate copolymer rubber (ER). ), chlorosulfonated polyethylene rubber (CSM), chlorinated polyethylene rubber (CM), and rubbers in which the conjugated diene moiety is hydrogenated (so-called hydrogenated NBR) such as acrylonitrile-butadiene copolymer rubber (NBR) are known. ing. On the other hand, in order to increase the heat resistance of rubber products, organic peroxide vulcanized rubber compositions that use organic peroxides are more heat resistant than sulfur vulcanized rubber compositions that use sulfur during vulcanization. It is known to have excellent sex. However, since organic peroxide vulcanized rubber compositions generally do not contain sulfur, they have poor adhesion to brass products such as brass-plated wire (hereinafter referred to as brass wire); for example, they cannot be used under high temperature and high pressure. When brass wire is used as a reinforcing material for rubber products, there are drawbacks such as destruction of the product due to interfacial peeling between the wire and the brass wire. In addition, organic peroxide vulcanized rubber compositions have the disadvantage that, unlike ordinary sulfur vulcanized rubber compositions, sulfur/organic peroxides interfere with each other by inhibiting the reaction, so the vulcanized physical properties do not appear and they do not adhere. . OBJECT OF THE INVENTION The object of the present invention is to provide an organic peroxide vulcanized rubber composition and an organic peroxide vulcanized rubber composition that improve the drawbacks of the prior art described above and enable the production of rubber/metal composite products that can withstand long-term use in high-temperature environments. This provides a method for adhering to brass. Specific configuration of the invention The present invention provides a unit portion made of unsaturated nitrile with 10
Nitrile group-containing elastomer containing ~45% by weight
1 to 15 parts of organic peroxide vulcanizing agent per 100 parts by weight
A rubber composition (B) in which a three-component system of silica, a resorcin donor, and a methylene donor (hereinafter referred to as HRH) and a sulfur-based vulcanizing agent are blended on the rubber composition (A) in which parts by weight are blended. The object of the present invention is to provide a method of adhering a rubber composition and brass, in which a brass body is placed on the rubber composition, and a brass body is placed on top of the brass body, and the rubber composition and brass are bonded by vulcanization and integration. Here, as the above-mentioned resorcin donor, resorcin and a condensate of resorcin and formaldehyde, etc., and as the methylene donor,
It is well known that hexamethylenetetramine and the like are generally used. The present inventors have demonstrated excellent oil resistance and a temperature of 120℃ to 150℃.
We have conducted various research to produce rubber/metal composite products that can be used continuously for long periods of time. In general, organic peroxide-vulcanized acrylonitrile/butadiene copolymer rubber has excellent heat resistance and oil resistance, and copolymer rubber in which the conjugated diene portion of acrylonitrile/butadiene copolymer rubber is hydrogenated (so-called hydrogenated It is well known that the better the heat resistance (NBR) is and the higher the hydrogenation rate is, the more advantageous it is, and if the hydrogenation rate is high, vulcanization with an organic peroxide is necessary. Furthermore, it is known that these rubber compositions do not adhere to brass wires due to organic peroxide vulcanization. The present invention
We have found a method to improve the adhesion between these rubber compositions and brass wires, and we have developed a method to improve the adhesion between these rubber compositions and brass bodies such as brass wires.
The inventors have discovered that by blending a sulfur-vulcanized rubber composition containing HRH and vulcanizing the composition to integrate it, it is possible to impart adhesion between the rubber composition and brass wire, leading to the present invention. be. The present invention will be explained in detail below. In the present invention, the rubber composition (A) and the brass are bonded by disposing the rubber composition (B) on the rubber composition (A), further disposing the brass body on top of the rubber composition, and vulcanizing and integrating the composition. The rubber composition (A) has a strong initial adhesive strength, and the heat resistance and oil resistance of the rubber composition (A) can be effectively utilized in rubber products. (1) Rubber composition (A) Unit portion from unsaturated nitrile 1 to 100 parts by weight of a nitrile group-containing polymer containing 10 to 45% by weight of an organic peroxide vulcanizing agent.
This is a composition containing 15 parts by weight. If the unit portion from unsaturated nitrile is less than 10% by weight, the oil resistance of the rubber composition (A) will be poor, and 45
If it exceeds % by weight, cold resistance will deteriorate. In particular, when the following copolymer rubber called hydrogenated NBR is used in the rubber composition (A), a rubber composition (A) with excellent heat resistance and oil resistance can be obtained. In other words, hydrogenated NBR contains 10 to 45% by weight of units from unsaturated nitrile, 0 to 20% by weight of units from conjugated diene, and ethylenically unsaturated monomers other than unsaturated nitrile. It is a copolymer rubber having 90 to 35% by weight of unit parts obtained by hydrogenating unit parts from and/or conjugated dienes, and has a saturated methylene chain (C-C) represented by the following formula, a nitrile group part ( VCN), a copolymer rubber composed of carbon-carbon double bond moieties (C=C). [C-C] [VCN] -(-CH ₂ -CH=CH-CH ₂ -) _Z [C=C] Here, it is written as a nitrile group moiety (VCN)

[Formula] is a unit portion from an unsaturated nitrile and is 10 to 45% by weight. If it is less than 10% by weight, oil resistance will be poor and 45
If it exceeds % by weight, cold resistance will deteriorate. (-
CH ₂ −CH ₂ − ₎ Weight%. In particular, the hydrogenation rate is preferably 95% or more. If the saturated methylene chain (C-C) is more than 90% by weight, the unit moiety from unsaturated nitrile (VCN)
is relatively reduced, and the oil resistance is poor, making it unusable. In addition, if the saturated methylene chain (C-C) is less than 35% by weight and the unit portion (VCN) from unsaturated nitrile is large, the cold resistance will be poor, and the saturated methylene chain (C-C) will be less than 35% by weight. Unit parts (VCN) from unsaturated nitriles are less than
As the amount of the C═C portion, which will be described later, increases, the resistance to deteriorated oil deteriorates. ( _-CH2 -CH=CH- _CH2- ) _Z is a unit moiety from a conjugated diene, from 0 to 20% by weight, written as a carbon-carbon double bond moiety (C=C) be. This is because if it is outside this range, the resistance to deteriorated oil will be poor. Specific examples of such copolymer rubbers include butadiene-acrylonitrile copolymer rubber, isoprene-acrylonitrile copolymer rubber, hydrogenated butadiene-isoprene-acrylonitrile copolymer rubber, etc.: butadiene-methyl acrylate-acrylonitrile copolymer rubber , butadiene-acrylic acid-acrylonitrile copolymer rubber, etc., and their hydrogenated products: butadiene-ethylene-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate-vinyl chloroacetate-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate Examples include -vinylnorporene-acrylonitrile copolymer rubber and hydrogenated products thereof. These copolymer rubbers may be used alone or in some cases in combination with other rubbers to the extent that the gist of the present invention is not impaired. Rubber composition (A) is made by mixing and kneading the copolymer rubber with commonly used fillers, reinforcing agents, plasticizers, anti-aging agents, other compounding agents and the following vulcanizing agent as required. A composition. Organic peroxides as vulcanizing agents are used in rubber compositions
In (A), any organic peroxide may be used as long as the crosslinking reaction does not proceed extremely at the processing temperature.
Preferably, dialkyl peroxide has a half-life of 10 hours and a decomposition temperature of 80°C or higher. For example, dicumyl peroxide, 1,3-
Bis-(t-butyl-peroxy-isopropyl)benzene, 4,4-di-tert-butylperoxyvaleric acid n-butyl are mentioned. The organic peroxide vulcanizing agent is blended in an amount of 1 to 15 parts by weight per 100 parts by weight of the above-mentioned nitrile group-containing polymer. If it is less than 1 part by weight, there will be few crosslinking points, making it difficult to develop physical properties, and if it exceeds 15 parts by weight, organic peroxide residue will affect heat aging, which is undesirable. (2) Rubber composition (B) Any rubber composition containing silica, a resorcin donor, and a methylene donor may be used as long as it uses sulfur as a vulcanizing agent, but preferably diene rubber 100 Based on the weight part, 1 to 100 parts by weight of silica, preferably 1 to 50 parts by weight, 0.5 to 20 parts by weight of resorcinol,
A rubber composition containing preferably 1 to 10 parts by weight, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight of hexamethylenetetramine, a sulfur-based vulcanizing agent, and other necessary compounding agents. be. If the amount of silica is less than 1 part by weight, it will not be effective in adhesion, and if it is more than 100 parts by weight, it will have a high viscosity and cannot be put to practical use. Less than 0.5 parts by weight of resorcin donor is similarly ineffective for adhesion and 20 parts by weight.
Even if it exceeds parts by weight, it still has no effect on adhesion. If the amount of methylene donor is less than 0.1 part by weight, there is no effect on adhesion, and if it exceeds 10 parts by weight, the scorch will be short, resulting in poor processing stability and cannot be used practically. Typical sulfur-based vulcanizing agents include sulfur, sulfur chloride, organic sulfur-containing compounds, and the like. The amount of the sulfur-based vulcanizing agent is 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the diene rubber. If it is less than 0.1 part by weight, there will be no adhesive effect;
If it exceeds 30 parts by weight, the vulcanization reaction of the organic peroxide vulcanized rubber composition will be inhibited, resulting in the opposite effect. By disposing the rubber composition (B) on the rubber composition (A) and further disposing the brass body thereon, adhesive force between the rubber composition (A) and the brass body can be imparted. The method of disposing the rubber composition (B) on the rubber composition (A) and then disposing the brass body on top of it may be in any form depending on the type of rubber product, but Taking advantage of the excellent characteristics of the rubber composition (A), the rubber composition (A) is placed on the surface that will be subjected to high heat and pressure, and the rubber composition (B) is used as an adhesive layer between the rubber composition (A) and the brass body as a reinforcing material. It is configured via Brass bodies are mainly used as reinforcing materials for rubber products such as hoses and tires.
It may be made of any material such as a pipe material, a plate material, or a steel material, and may be made of high carbon steel or other metal plated with a Cu-Zn alloy. A brass body is placed on the rubber composition (A) via the rubber composition (B), and then vulcanized and integrated. The vulcanization conditions can be selected in any way depending on the type of rubber product, but the vulcanization temperature is preferably 130°C to 200°C, and the vulcanization method is normal press vulcanization, steam vulcanization, Commonly used methods such as hot water vulcanization are possible. The method of the present invention can be applied to many rubber products such as tires, belts, molds, rolls, and hoses that require oil resistance after long-term use in high-temperature, high-pressure environments. Examples The present invention will be specifically described below using Examples and Comparative Examples. <Example> The rubber compositions of Formulation Examples 1 to 3 shown in Tables 1 and 2 were mixed for 15 minutes on a 60°C mixing roll, and used as samples for each test shown below. (1) Rubber/rubber adhesion test method Each sample of Formulation Examples 1 to 3 was rolled out into a sheet with a thickness of 2.0 mm using a small laboratory roll.
Samples for rubber/rubber adhesion tests were prepared in the following manner using Compound Example 2 as a rubber composition (A) and Compound Example 3 as a rubber composition (B). As shown in FIG. 1, rubber composition (A) 1 and rubber composition (B) 2 each having a thickness of 15 cm x 10 cm x 2 mm were arranged. During the peel test, cellophane paper 3 was placed on the part to be gripped by the chuck to prevent the upper and lower layers from adhering. This sample was molded using a laboratory press molding machine.
Pressure vulcanization was carried out at a temperature of 30 kgf/cm ² for 90 minutes at a temperature of 30 kgf/cm 2 to form a single piece. After standing at room temperature for 24 hours, the sample was cut into a 2.54 cm width and subjected to a peel test. The peel force was measured using a tensile tester specified in JIS K6301 at a tensile speed of 50 mm/min. Calculation of peeling force is based on JIS K6301 8, 3, 3.
This was carried out in accordance with the method described in (3). (2) Rubber/rubber/brass adhesion test method Using a small laboratory roll, sheet the samples of Formulation Examples 1 to 3 to a predetermined thickness.
Samples for rubber/rubber/brass adhesion tests were prepared in the following manner using a rubber composition (A) as a rubber composition (A) and a rubber composition (B) as Blending Example 3. As shown in FIG. 2, rubber composition (A) 1, rubber composition (B) 2, and brass plate 4 of 15 cm×10 cm×predetermined thickness were applied. During the peel test, cellophane paper 3 was placed on the part to be gripped by the chuck to prevent the upper and lower layers from adhering. This sample was molded using a laboratory press molding machine.
Pressure vulcanization was carried out at a temperature of 30 kgf/cm ² for 90 minutes at a temperature of 30 kgf/cm 2 to form a single piece. After leaving it at room temperature for 24 hours, a peel test was conducted between the second rubber layer and the brass plate. The peel force was measured using a tensile tester specified in JIS K6301 at a tensile speed of 50 mm/min. All other procedures were conducted in accordance with the methods described in JIS K6301 8.3. The following experimental results are shown in Table 3. <Comparative Example> As a comparison, a case in which the rubber composition of the second layer was not used and was bonded directly to brass (Comparative Example 1 and Comparative Example 2 in Table 4) and a case in which the rubber composition was not used, which did not contain silica, resorcinol, or hexamethylenetetramine, were compared. Rubber compositions (Comparative Examples 3, 4, 5, and 6) in which Formulation Example 4 shown in Table 2 was used for the second layer in the same manner as in the Examples were used as adhesive test samples in the same manner as in the Examples. A similar experiment was conducted as follows. The results are shown in Table 4.

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[Table] Effects of the Invention The method of adhering the rubber composition and brass of the present invention enables adhesion between brass and a nitrile group-containing elastomer blended with an organic peroxide vulcanizing agent, which was previously difficult. It has become possible to manufacture rubber/metal composite products with excellent properties such as hardness and oil resistance.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a sample used in the rubber/rubber adhesion test. FIG. 2 is a cross-sectional view of a sample used in the rubber/rubber/brass adhesion test. Explanation of symbols: 1... Rubber composition (A), 2... Rubber composition (B), 3... Cellophane paper, 4... Brass plate.

Claims (1)

[Claims] 1. On a rubber composition (A) containing 1 to 15 parts by weight of an organic peroxide vulcanizing agent to 100 parts by weight of a nitrile group-containing elastomer containing 10 to 45% by weight of units derived from unsaturated nitrile. , a rubber composition (B) containing silica, a resorcin donor, a methylene donor, and a sulfur-based vulcanizing agent is placed on top of the rubber composition (B), and a brass body is placed on top of the rubber composition (B), which is then vulcanized and bonded together. Adhesion method between rubber composition and brass.