JPH06157826A - Acrylic rubber composition - Google Patents

Abstract

PURPOSE:To prevent an acrylic rubber product, such as a packing, an O-ring, an oil seal or a hose, from sticking to and corroding a metal in contact therewith and obtain a rubber composition which facilitates the replacement of the product for maintenance and is excellent in the prevention of the sticking and corrosion. CONSTITUTION:An acrylic rubber is mixed with a chelate compound or at least one metal or compound selected from chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum, tin, lead, tellurium, compounds of these metals and a phosphorus compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a crosslinkable acrylic rubber composition for a member that contacts metal. More specifically, the present invention relates to a compounding composition for preventing sticking between a crosslinkable acrylic rubber and a metal in contact therewith and metal corrosion.

[0002]

Acrylic rubber is known as an elastomer having good heat resistance, oil resistance, weather resistance and compression set. Therefore, it is used for various hoses, packings, sealing materials, etc. Sealing materials are used as sealing rubbers by pressure bonding with materials that come into direct contact with them, such as cast iron and mild steel.However, there is a problem that the rubber may stick and remain on the metal surface or corrode the metal. There is. Further, as a hose material, there is a problem that rubber is fixed to a fastening fitting or a metal pipe, or metal is corroded.

Here, the sticking means that the rubber for contact and the contact material are compressed by about 10 to 40%, and when left in air or oil for a certain temperature for a certain time, the rubber reacts with the contact material and peels off. Even if it does, it shows a state in which it cannot be removed. Conventionally, various studies have been conducted in order to improve adhesion between acrylic rubber and a metal and corrosion of a metal, but no satisfactory results have been obtained.

[0004] For example, as described in Japanese Patent Laid-Open No. 17435/1993, as a method for preventing sticking, a method of coating a reactive silicone liquid on acrylic rubber, followed by drying and silicone coating, and a plasticizer in rubber, etc. Is added as a compounding agent to cause bleeding on the rubber surface so as not to directly contact with a metal, but in either case, the original performance of the acrylic rubber is not fully exerted, resulting in an increase in cost and deterioration in physical properties such as heat resistance.

[0005]

However, a satisfactory method has not been obtained by the conventional methods. The present invention is
Acrylic rubber for rubber products such as packing, O-ring,
An object of the present invention is to provide a rubber composition that prevents sticking and corrosion of a metal such as an oil seal or a hose that comes into contact with acrylic rubber and prevents corrosion and facilitates replacement during maintenance.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have made it possible to obtain a crosslinkable acrylic rubber composition which prevents the performance of acrylic rubber from deteriorating and does not increase the cost, and prevents the metal from coming into contact with it and from corrosion. As a result of earnest study, acrylic rubber is blended with at least one selected from chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum, tin, lead, tellurium or metal compounds thereof, or phosphorus compound, It has also been found that an acrylic rubber composition free from metal sticking and corrosion can be obtained by adding a chelate compound having a chelating effect to acrylic rubber.

The acrylic rubber used in the present invention includes about 30 to 100% by weight of an alkyl acrylate monomer.
And at least one other monomer copolymerizable with about 70
It is an elastomeric copolymer obtained by copolymerizing 0 to 0% by weight. Examples of the alkyl acrylate monomer include alkyl acrylate, alkoxyalkyl acrylate, alkylthioalkyl acrylate, and cyanoalkyl acrylate.

As the acrylic rubber, 5 to 45% by weight of ethyl acrylate and 5 of butyl acrylate are preferable.
˜45 wt%, alkoxy acrylate 5˜50 wt%, and other copolymerizable monomer 0˜20 wt%.

Other monomers that can be copolymerized include acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, monomethyl maleate, monoethyl maleate and malein. Acid monobutyl, styrene, α-methylstyrene, halogenated styrene, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-methylolacrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, vinyl acetate, vinyl chloride, vinylidene chloride, methyl Monovinyl-based or monovinylidene-based unsaturated compounds such as methacrylate, ethyl methacrylate, cyclohexyl acrylate, benzyl acrylate, and furfuryl acrylate, Divinylbenzene, aryl acrylates, the aryl methacrylates, alkylene glycol diacrylates, alkylene glycol dimethacrylate, polyalkylene glycol diacrylates, polyalkylene glycol dimethacrylate, trimethylolpropane triacrylate and the like.

Further, a monomer serving as a crosslinking point may be copolymerized, which includes a halogen-containing monomer, an epoxy-containing monomer, a carboxy-containing monomer and a diene-containing monomer. A monomer that can be used can be used. As the halogen-containing monomer, 2-chloroethyl vinyl ether,
2-chloroethyl acrylate, vinylbenzyl chloride, vinyl chloroacetate, allyl chloroacetate and the like.

Examples of the epoxy-containing monomer include glycidyl (meth) acrylate, vinyl glycidyl ether, allyl glycidyl ether and methacryl glycidyl ether. Examples of the carboxy-containing monomer include acrylic acid, methacrylic acid and itaconic acid. Examples of the diene-containing monomer include butadiene, isoprene, piperylene,
There is ethylidene norbornene.

For acrylic rubber, chromium, manganese,
Iron, cobalt, nickel, copper, zinc, aluminum, tin, lead, tellurium and the like, or as a compound thereof, in order to obtain a good dispersed state in the rubber, it is desirable that it is a fine powder, an organometallic compound, It may be an inorganic metal compound. Organic metal compounds include zinc stearate, aluminum stearate, lead stearate, and the like, and inorganic metal compounds include metal oxides such as tellurium dioxide, copper oxide, zinc oxide, lead oxide, and aluminum oxide.

Examples of the phosphorus compound include inorganic substances such as phosphoric anhydride, tris (nonylphenyl) phosphite used as an antiaging agent, diisodecylpentaerythritol diphosphite, and tributyl phosphate used as a plasticizer. Alternatively, there are alkyl phosphate ester salts and alkyl ether phosphate ester salts used for surfactants.

Examples of the compound having a chelating effect used in the present invention include commercially available chelating agents such as dimethylglyoxime, dithizone and saltylaldehyde. Further, examples of the N-containing heterocyclic compound include benzotriazole, oxine, and amine-based antioxidant poly (2,2,4-trimethyl-1,2-dihydroquinoline). Further, it is composed of one kind or a mixture of two or more kinds selected from aliphatic amines having two or more amino groups, aminoalcohol, urea, aminocarboxylic acid and the like.

These include dimethylglyoxime, N-propanolamine, 2-amino-2-methylpropanoltriethylenetetramine, aromatic amino compounds, dithizone, N, N'bis [3- (3,5-di-t-butyl-4- Examples thereof include bidroxyphenyl) propionyl] hydrazine and N, N ′ bis [3- (4-hydroxyphenyl) propionyl] hydrazine. Further, as the salicylic acid derivative, salicylic acid, salicylic acid aldehyde and the like are also used.

The metal simple substance or the metal compound used in the present invention is 0.05 part by weight to 100 parts by weight, preferably 0.3 part by weight to 50 parts by weight, based on 100 parts by weight of the acrylic rubber. More preferably, 0.3 to 20 parts by weight is blended, and further, the phosphorus compound is blended in an amount of 0.05 to 100 parts by weight, preferably 0.2 to 20 parts by weight. A good acrylic rubber composition without corrosion can be obtained.

A metal element or a metal compound is added in an amount of 0.05
If it is less than 100 parts by weight, the effect of preventing sticking to metal and corrosion will be small, and if it exceeds 100 parts by weight, workability during kneading will be poor, such being undesirable. When the phosphorus compound is less than 0.05 parts by weight, the effect of preventing sticking to metal and corrosion is small, and when it is 100 parts by weight or more, vulcanization is hindered and the strength of the vulcanizate is decreased. Of these, it is particularly preferable to use a phosphorus compound or a phosphorus compound and a metal compound in combination.

The compound having a chelating effect used in the present invention is 0.0 per 100 parts by weight of acrylic rubber.
1 to 50 parts by weight, preferably 0.1 to 20 parts by weight are added. If the amount is less than 0.01, the effect of preventing sticking to metals and corrosion is small, and if the amount exceeds 50 parts by weight, an appropriate vulcanized product cannot be obtained, and strength and elongation are reduced, and the vulcanization speed is high. Will be difficult.

The vulcanizing agent depends on the presence or absence of a crosslinking group or the type of the crosslinking group contained, and is not particularly specified. For example, chlorine-based compounds are triazine compounds and dithiocarbanates, or metal soaps and sulfur, etc., epoxy-based compounds are polyamines, ammonium benzoate, etc., and carboxy-based compounds are ethylene glycol glycidyl ether, polyamines, etc. The diene type is an organic peroxide such as sulfur and a vulcanization accelerator or dicumyl peroxide, and may be an organic peroxide such as dicumyl peroxide as long as it does not contain a crosslinking group.

For the vulcanization, generally used rubber compounding agents can be used. For example, roll mixing, Banbury mixing together with a reinforcing agent, a filler, an antioxidant, a stabilizer, a retarder, a plasticizer, a processing aid, a lubricant and the like. After mixing with rubber by a commonly used method such as solution mixing, heating is performed. The vulcanization temperature is usually 150 ° C or higher,
Press vulcanization and post-vulcanization are performed at this temperature, or vulcanization is also performed by steam vulcanization.

[0021]

EXAMPLES The present invention will be described in detail based on examples. Examples 1 to 12, Comparative Examples 1 to 6 With respect to 100 parts by weight of acrylic rubber (JSR AREX 411 active chlorine-based ultra-cold resistance type), 60 parts by weight of carbon black (Tokai Carbon Seast 116), 1 part by weight of stearic acid, After kneading 2 parts by weight of an antioxidant (Nocrac CD manufactured by Ouchi Shinko Co., Ltd.), a metal compound and a phosphorus compound shown in Tables 1 and 2 with a compound having a chelating effect with a Banbury mixer, triazine (3: Kyokasei Disnet F) 0.8 parts by weight, vulcanization accelerator BZ
(Ouchi Shinko Nox Cellar BZ) 2.0 parts by weight was added by an open roll. After kneading, the sample for compression set test of JIS K6301 was subjected to 170 ° C. vulcanizing press.
It was vulcanized for 20 minutes, and as post-vulcanization, it was vulcanized at 175 ° C. open for 4 hours.

In the sticking and corrosion tests, a sample for compression set test was sandwiched between mild steel plates, compressed by a compression set compression tester, dipped in a pressure vessel containing oil, sealed in a pressure vessel, and then heated at high temperature (100 Left in the open for a long time (50-200 hours). After dipping under predetermined conditions, the sample was taken out, the metal plate and the rubber were peeled off, and the metal surface in contact with the rubber was observed. The results are shown in Table 1 for the examples and Table 2 for the comparative examples.

Examples 13 to 23, Comparative Example 7 60 parts by weight of carbon black (Shikai 116 made by Tokai Carbon Co., Ltd.) and 1 part by weight of stearic acid per 100 parts by weight of acrylic rubber (JSR AREX 411 active chlorine type ultra-cold resistant type). After kneading 2 parts by weight of an antioxidant (Nocrac CD manufactured by Ouchi Shinko Co., Ltd.) and a metal compound, a phosphorus compound and a compound having a chelating effect shown in Table 3 with a Banbury mixer, sodium stearate 2.5 is used as a vulcanizing agent. Parts by weight, 0.5 parts by weight of potassium stearate,
0.3 part by weight of sulfur was added by an open roll. Vulcanization was carried out in the same manner as in the above example, and the results of fixation and corrosion test of the vulcanized product are shown in Table 3.

Examples 24 to 34, Comparative Example 8 60 parts by weight of carbon black (SEATO 116 made by Tokai Carbon), 1 part by weight of stearic acid, and 100 parts by weight of acrylic rubber (JSR AREX 320 epoxy super cold resistant type) were aged. Inhibitor (Ouchi Shinko Nocrac C
D) 2 parts by weight and a metal compound, a phosphorus compound, and a compound having a chelating effect shown in Table 4 are kneaded in a Banbury mixer, and then, as a vulcanizing agent, 1.5 parts by weight of ammonium benzoate (Barnock AB manufactured by Ouchi Shinko Co., Ltd.) Was added with an open roll. Vulcanization was carried out in the same manner as in the above example, and the results of fixation and corrosion test of the vulcanized product are shown in Table 4.

Examples 35 to 45, Comparative Example 9 60 parts by weight of carbon black (Shikai 116 made by Tokai Carbon) and 1 part by weight of stearic acid per 100 parts by weight of acrylic rubber (cold resistant type for JSR AREX 290 peroxide crosslinking). After kneading 2 parts by weight of an antioxidant (Nocrac CD manufactured by Ouchi Shinko Co., Ltd.), a metal compound and a phosphorus compound shown in Table 5, and a compound having a chelating effect with a Banbury mixer, an organic peroxide (chemical agent) as a vulcanizing agent 2.5 parts by weight of Perkadox 14/40 manufactured by Akzo and 2.5 parts by weight of a crosslinking aid (Barnock PM manufactured by Ouchi Shinko) were added by an open roll. Vulcanization was performed in the same manner as in the above example, and the results of fixing and corrosion test of the vulcanized product are shown in Table 5.

Examples 46 to 56, Comparative Example 10 Carbon black (Tokai Carbon Seast 11) was added to 100 parts by weight of acrylic rubber (decane ER-5300; ethylene / vinyl acetate / acrylic acid ester copolymer).
6) 60 parts by weight, 1 part by weight of stearic acid, 2 parts by weight of an antiaging agent (Nocrac CD manufactured by Ouchi Shinko Co., Ltd.), a metal compound and a phosphorus compound shown in Table 6, and a compound having a chelating effect are kneaded with a Banbury mixer. Then, 2.0 parts by weight of a vulcanizing agent (CN-25 manufactured by Shikoku Kasei) was added by an open roll. Vulcanization was carried out in the same manner as in Example 1, and the fixing and corrosion test results of the vulcanized product are shown in Table 6. As shown in the table below, the compounds of the present invention are effective.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Table 4]

[0031]

[Table 5]

[0032]

[Table 6]

[0033]

When the acrylic rubber is used in contact with a metal, for example, as a packing, an O-ring, an oil seal or a hose, there is a problem that the rubber is fixed to the metal or corroded. Therefore, it was difficult to replace the rubber product at the time of maintenance, but since the acrylic rubber composition obtained by the present invention is excellent in adhesion and corrosion prevention, various hoses and various seals (gaskets, O-rings) , Packings, oil seals), diaphragms, etc., can be widely used for applications in contact with metals.

[Procedure amendment]

[Submission date] March 24, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title of the invention Acrylic rubber composition

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location C08L 33/08 LHV 7921-4J (72) Inventor Ken Akiyama 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd.

Claims (2)

[Claims] 1. Acrylic rubber, chromium, manganese,
Acrylic rubber composition for a member in contact with a metal, characterized in that it contains at least one selected from iron, cobalt, nickel, copper, zinc, aluminum, tin, lead, tellurium or a metal compound thereof, or a phosphorus compound. object. 2. An acrylic rubber composition for a member which comes into contact with a metal, characterized in that a compound having a chelating effect is blended with acrylic rubber.