JPH0466183B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a laminate of an acrylic elastomer and a fluorine-based elastomer, which has improved interfacial adhesion, is excellent in durability, and is inexpensive. More specifically, the present invention provides a material in which a highly durable fluorine-based elastomer is placed on the surface where durability is most required, and a relatively inexpensive and durable acrylic elastomer is placed on this. The purpose is to provide an inexpensive elastomer laminate with excellent durability, and this elastomer laminate is created by vulcanizing and adhering an acrylic elastomer to a fluorine-based elastomer using a specific vulcanizing agent to create a laminate interface. This has significantly improved adhesive strength. This elastomer laminate is useful as various rubber products. For example, a composite hose in which the outer tube is made of fluorine-based elastomer and the inner tube is made of acrylic elastomer provides a radiator hose that is durable against radiant heat around the engine. Composite hoses made of acrylic elastomer must not contain fluids that impair the durability of rubber materials other than fluorine-based elastomers, such as high-temperature engine oil, high-temperature air, high-temperature gases, or swelling liquids, gases, or mist. The present invention provides a hose suitable for passing through the hose. (Prior Art) Conventionally, for rubber parts that come into contact with high-temperature fluids, a single rubber material that does not lose its durability even when it comes into contact with the fluid has been selected and used. For example, nitrile rubber (NBR), which has excellent oil resistance, has been used for lubricating oil hoses, and elastomer (EPR), whose main components are ethylene and propylene, which have excellent antifreeze and heat resistance, has been used for automobile radiator hoses. However, due to various technological innovations in recent years, the temperature inside the engine compartment of a car is on the rise.
Nitrile rubber has insufficient durability as a lubricating oil hose, and acrylic elastomer, which is more durable, has been used. However, it has been pointed out that the durability of acrylic elastomers is reduced by various additives in engine oil. Additionally, materials with higher heat resistance are attracting attention for radiator hoses due to the radiant heat from surrounding heat sources. Therefore, in order to solve the above problems and improve the reliability of rubber parts, it is easy to consider using highly durable fluorine-based elastomers, but fluorine-based elastomers have poor cold resistance and are expensive. Therefore, it cannot be said to be a perfect material, and is particularly unsuitable for automobile parts that require both cost and reliability. Therefore, the next best method is to coat only the areas where durability is a real issue with conventional materials with fluorine-based elastomer to substantially increase durability. be. (Problems to be Solved by the Invention) However, when covering an acrylic elastomer with a fluorine-based elastomer, the interfacial strength of adhesion between the two is low, and the reliability of the laminate is impaired. In order to obtain a durable and inexpensive composite, it is extremely important to improve the adhesive strength between the two. (Means for Solving the Problems) Therefore, in order to obtain a laminate of fluorine-based elastomer and acrylic elastomer that is inexpensive and has substantial durability, the inventors made efforts to improve the adhesive strength of the fluorine-based elastomer and acrylic elastomer. By blending a specific vulcanizing agent into the fluorine-based elastomer, we have succeeded in improving the vulcanization adhesive strength of the fluorine-based elastomer and acrylic elastomer, resulting in an inexpensive, durable, and highly reliable laminate. . That is, the present invention provides a laminate formed by laminating an acrylic elastomer and a fluorine-based elastomer. This is an elastomer laminate characterized by being formed by vulcanizing a combination of an acrylic elastomer compound containing an acid adduct (hereinafter referred to as "the vulcanizing agent of the present invention") and a fluorine-based elastomer compound. Acrylic elastomer is an elastomer whose main component is acrylic acid ester and whose crosslinking sites are epoxy groups.It is currently commercially available as a heat-resistant and durable material with the product name JSR AR.
(Japan Synthetic Rubber Co., Ltd.), Nippor AR (Nippon Zeon Co., Ltd.), Noxtite (Japan Oil Seal Co., Ltd.), Toracron (Toa Paint Co., Ltd.), Denka ER (Electrochemical Co., Ltd.), etc. Fluorine-based elastomer refers to a copolymer of fluorocarbon and hydrocarbon, and JSR Aflas (Japan Synthetic Rubber Co., Ltd.) is commercially available. The vulcanizing agent of the present invention is blended into the acrylic elastomer. Since the vulcanizing agent of the present invention exhibits a high level of adhesive strength regardless of the amount added for the purpose of improving adhesive strength with fluorine-based elastomers, the amount used is determined by the physical properties of the obtained vulcanizate. is not self-limited by the acceptable level of In other words, when used alone, acrylic elastomer 100
It is preferably 0.5 part by weight or more based on the weight part, and if the amount added is less than 0.5 part by weight, the mechanical strength of the vulcanizate gradually decreases. In addition, the vulcanizing agent of the present invention can be used in combination with other vulcanizing agents for the purpose of further increasing the practicality of the vulcanizate without losing its effectiveness. For example, sodium alkyl sulfate, ammonium benzoate, Examples include -0-tolylguanidine, diphenylguanidine, hexamethylene diamine carbamate, N,N'-dicinnamylidene-1,6-hexane diamine, polybasic acids and their anhydrides, and quaternary ammonium salts. The present invention does not require any special restrictions on the compounding agents added to the fluorine-containing elastomer, but if a large amount of a drug with poor compatibility with the fluorine-containing elastomer is filled, it may cause damage to the surface of the fluorine-containing elastomer. Care must be taken as the compounding agents may bleed or bloom, which may impede interfacial adhesion. Normally, processing aids, reinforcing agents, fillers, and vulcanizing agents (mainly organic peroxides and polyfunctional monomers) are added to fluorine-based elastomers to improve their properties after vulcanization. The type and amount are selected depending on the use of the fluorine-based elastomer. Compounds of fluorine-based elastomers and acrylic elastomers can be prepared by any method normally used in the rubber industry, and oven rolls or internal mixers are usually used. Furthermore, in addition to the above-mentioned compounding agents, it is of course possible to add various compounding agents to the compound of fluorine-based elastomer and acrylic elastomer in order to provide the desired performance to each vulcanizate. be. Common methods for obtaining the desired laminate include bonding using a calendar, compounding using an extruder, and the like. Vulcanization of the laminate is not subject to any limitations other than the required time and temperature to achieve sufficient crosslinking.
A preferred method for obtaining a stable vulcanizate is to heat-treat the primary vulcanizate in an air oven if necessary and then perform vulcanization. The laminate of the present invention is particularly useful in practice in the form of a hose. For example, a radiator hose with an outer tube made of fluorine-based elastomer and an inner tube made of acrylic elastomer, which is more durable than an EPR hose; a hose made of acrylic rubber with an inner tube made of fluorine-based elastomer and an outer tube made of acrylic elastomer; NBR
A lubricating oil hose that is more durable than manufactured hoses.
This provides an effective means of obtaining a heater hose that is more durable than EPR hoses. (Example) The effectiveness of the present invention will be explained below using Examples. Examples 1 to 12 Comparative Examples 1 to 3 JSR Aflas (manufactured by Japan Synthetic Rubber Co., Ltd.) was used as the fluorine-based elastomer and the following acrylic ester copolymer was used as the acrylic elastomer. A compound was prepared, sheeted, and both unvulcanized rubber sheets were laminated together, followed by press vulcanization at 150°C for 30 minutes.
After vulcanization in an air oven at 150℃ for 8 hours,
A laminate vulcanizate was produced. A vulcanizate of the above-mentioned acrylic elastomer compound was also obtained under the same conditions. The adhesive strength of the vulcanized laminate and the physical properties of the acrylic elastomer vulcanizate were measured in accordance with JIS/K6301. The results are shown in Table-1. The acrylic ester copolymer used was produced as follows. That is, 43 kg of water, 7 kg of vinyl acetate, and each of electrified Poval B-05 and B-17 as polyvinyl alcohol were placed in an autoclave.
700g of sodium acetate, 60g of sodium acetate, 2g of ferric sulfate, 4g of ethylenediaminetetraacetic acid, and 90g of a cocatalyst were added and mixed with stirring, and the internal temperature was brought to 45°C in an autoclave. The air above the autoclave was replaced with nitrogen, and then ethylene was introduced under pressure to bring the ethylene pressure to 50 kg/cm ² .
Polymerization initiator aqueous solution, acrylic acid n from a separate injection port
-13 kg of butyl, 8 kg of ethyl acrylate and 420 g of glycidyl methacrylate were injected to allow polymerization to proceed, and the injection was completed in 12 hours. An aqueous solution of Glauber's salt was added to the produced polymer emulsion to solidify the polymer, which was washed with water, dehydrated and dried, and the resulting polymer was used as an acrylic ester copolymer for testing. Composition of elastomer (1) The following basic composition was used for the afros to be bonded. JSR Aflas 150E ₁₎ 100 parts by weight Carbon Black MT ₂₎ 15 parts by weight Nipseal VN-3 ₃₎ 10 parts by weight Peroximon F-40 ₄₎ 2.5 parts by weight (2) The following compounding method was used for the acrylic elastomer. . Acrylic elastomer 100 parts by weight Stearic acid 1 part by weight Naugaard #445 ₅₎ 1 part by weight Carbon Black MAF ₆₎ 75 parts by weight Adekasizer RS-700 ₇₎ 10 parts by weight Liquid paraffin 3 parts by weight Vulcanizing agent Shown in Table-1 Street (Note) 1 Fluorine elastomer manufactured by Japan Synthetic Rubber Co., Ltd. 2 Sterling MT manufactured by Cabot 3 Hydrated silicic acid manufactured by Nippon Silica 4 Organic peroxide manufactured by Nippon Oil & Fats Co., Ltd. 5 Anti-aging agent manufactured by Koni Royal Co., Ltd. 6 Manufactured by Tokai Carbon Co., Ltd. Seast #116 7 Plasticizer manufactured by Adeka Argus

[Table] (Effects of the Invention) As shown in Table 1, the laminates vulcanized and bonded using the vulcanizing agent of the present invention exhibit good adhesive strength.

Claims (1)

[Claims] 1 In a laminate formed by laminating an acrylic elastomer and a fluorine elastomer, 2,4-
It is made by combining and vulcanizing an acrylic elastomer compound containing a diamino-6(2'-methylimidazolyl-(1)')ethyl-S-triazine isocyanuric acid adduct and a fluorine-based elastomer compound. Characteristic elastomer laminate.