JPH0397749A - Cured composition of copolymer rubber - Google Patents

Abstract

PURPOSE:To obtain a cured composition quickly curing and having excellent physical properties of cured material by mixing a specific copolymer rubber containing a (meth)acrylate of cyano group-containing caprolactone oligomer with a quaternary ammonium salt, etc. CONSTITUTION:A1: 0.5-99.9wt.% (meth)acrylate of cyano group-containing caprolactone oligomer expressed by the formula (R<1> is H or methyl; R2 is cyano group-substituted alkyl, preferably 2-cyanoethyl or 2-cyanopropyl; n>=1 and average value is 1-10) is mixed with A2: 0.1-10wt.% epoxy group-containing monomer and A3: 0-99.4wt.% copolymerizable monomer and polymerized to obtain copolymer rubber having glass transition point below room temperature, preferably <=0 deg.C. Then, (A) 100 pts.wt. said copolymer is mixed with (B) 0.1-10 pts.wt., preferably 0.5-5 pts.wt. quaternary ammonium salt or quaternary phosphonium salt as a curing agent.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a vulcanizable copolymer rubber composition that rapidly vulcanizes and provides a vulcanizate with excellent heat resistance, oil resistance, and cold resistance. It is something.

[Conventional technology] In recent years, as a result of automobile exhaust gas regulation measures and engine improvements aimed at improving performance, the environments in which rubber parts are used have become increasingly harsh. There is a demand for rubber materials with high properties.

A copolymer rubber containing a portion of acrylic ester or methacrylic ester of a cyano group-containing white cabrolactone oligomer has excellent oil resistance and heat resistance. (For example, JP-A-1-132611) However, the copolymer in which epoxy groups are introduced as crosslinking points is an organic carboxylic acid ammonium salt such as ammonium benzoate, which has been known as a vulcanizing agent for epoxy group-containing acrylic rubber. It is possible to vulcanize by using a dialkyl rubber metal salt such as zinc dimethyldithiocarbamate as a vulcanizing agent, but the vulcanization rate is slow and it takes a long time to obtain a vulcanizate with satisfactory physical properties. There was a problem in that vulcanization was required after a period of time.

[Problems to be Solved by the Invention] As a result of various studies to solve the above-mentioned problems, the present inventors found that epoxy group-containing monomers and acrylic esters or methacrylates of cyano group-containing cabrolactone oligomers Copolymer rubber containing acid ester as an essential component is
It has been found that by using a quaternary ammonium salt or a quaternary phosphonium salt as a vulcanizing agent, vulcanized rubber can be rapidly vulcanized and have satisfactory physical properties in a short vulcanization time.

[Means for Solving the Problems] The present invention provides 1) the following formula (I) l (where R is hydrogen or a methyl group, R2 is a cyano group-substituted alkyl group, and n is an integer of 1 or more; , the number average value of which is 1 to 10.) 0.5 to 99.9% by weight of an acrylic ester or methacrylic ester of a cyano group-containing cabrolactone oligomer, 2) an epoxy group-containing monomer 0.1 to 10% by weight, and 3) 100 parts by weight of a copolymer rubber having a polymer composition of O to 99.4% by weight of a monomer copolymerizable with these, quaternary ammonium salts or quaternary phosphonium. Salts 0,,1~10
This is a vulcanizable rubber composition containing parts by weight.

The copolymer rubber used in the present invention is (A) an acrylic ester or methacrylic ester of a cyano group-containing cabrolactone oligomer represented by formula (1), 0.5 to
99.9% by weight, (B) epoxy group-containing monomer, 0.1
~ 10% by weight, (C) a monomer copolymerizable with the above (A) and (B), O ~ 99.4% by weight,
The copolymer has a glass transition point of room temperature, preferably 0° C. or lower.

The acrylic ester or methacrylic ester of a cyano group-containing cabrolactone oligomer as component (A) is a compound represented by formula (I).

Examples of R2 in formula (1) include 2-cyanoethyl group, 2
-cyanoprobyl group, 3-cyanoprobyl group, 2-cyanobutyl group, 3-cyanobutyl group, etc., but 2
-cyanoethyl group and 2-cyanobutyl group are particularly preferred. The acrylic ester or methacrylic ester of the cyano group-containing cabrolactone oligomer can be synthesized, for example, by the method described in JP-A-1-132611.

Examples of the epoxy group-containing monomer of component (B) include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and vinyl glycidyl ether. These can be used alone or in combination of two or more.

Examples of monomers that can be copolymerized with the acrylic ester or methacrylic ester of the cyano group-containing cabrolactone oligomer of Bokubun (C) and the epoxy group-containing monomer include methyl acrylate, ethyl acrylate, The number of carbon atoms in the alkyl group is 1, such as n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, probyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, etc. ~20 acrylic acid alkyl esters: methoxymethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate,
Acrylic acid alkoxyalkyl esters with an alkoxyl group or alkylene group having 1 to 4 carbon atoms such as methoxyethoxyethyl acrylate: methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, etc. Methacrylic acid alkyl esters in which the alkyl group has 1 to 20 carbon atoms: methoxymethyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate,
Methacrylic acid alkoxyalkyl esters such as butoxyethyl methacrylate and methoxyethoxyethyl methacrylate; Acrylic acids such as 2-cyanoethyl acrylate, 3-cyanobuvir acrylate, 2-cyanoethyl methacrylate, and 3-cyanobuvir methacrylate; Cyanoalkyl esters of methacrylic acid: Hydroxyalkyl esters of acrylic acid or methacrylic acid such as 2-hydroxyethyl acrylate, 2-hydroxybuvir acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxybuvir methacrylate: The following formula R3 (where R3 is hydrogen or a methyl group, R4 has 1 carbon number
-8 alkyl group or alkoxyalkyl group having 3 to 8 carbon atoms, n is an integer of 1 or more, and the number average value is 1
~ ] 0. ) Acrylic or methacrylic ester of ε-cabrolactone oligomer: vinyl acetate,
Vinyl esters such as vinyl propionate: styrene, α
- Aromatic vinyl compounds such as methylstyrene: Vinyl or vinylidene nitrile compounds such as acrylonitrile and methacrylonitrile: α-olefins such as ethylene and brobylene: Conjugated hydrogens such as butadiene and isobrene: dimethyl maleate, jetyl maleate, The alkyl group has 1 to 20 carbon atoms, such as di-n-butyl maleate, dimethyl fumarate, diethyl fumarate, and di-n-butyl fumarate.
Dialkyl esters of unsaturated dicarboxylic acids: Dialkoxyalkyl esters of unsaturated carboxylic acids such as dimethoxyethyl maleate and dimethoxyethyl fumarate: Vinyl ketones such as methyl vinyl ketone and ethyl vinyl ketone. These can be used alone or in combination of two or more. Among these, alkyl esters and alkoxy esters of acrylic acid or methacrylic acid are particularly preferred.

In the composition of the present invention, a portion (A) of an acrylic acid or methacrylic acid ester of a cyano group aa cabrolactone oligomer and a component (B) of an epoxy 2! A rubber-like congruent polymer containing a certain monomer as an essential component is a rubber-like contaminant having a certain amount (A> of a cyano group-containing cabrolactone oligomer having an f4 m content of acrylic acid or methacrylic acid ester of 60% by weight or less). Copolymers are particularly preferred from a practical standpoint.

The quaternary ammonium salt and quaternary phosphonium salt used in the present invention are compounds represented by the general formula. In the general formula, Y is nitrogen or a pseudo atom, and R-R8 is a hydrocarbon having about 1 to 25 carbon atoms, such as an alkyl group, an alkoxyalkyl group, a polyoxyalkylene group, an aryl group, or an alkylaryl group. At least one of these groups may contain an unsaturated bond or be substituted with a hydroxyl group. Furthermore, two or three of R - R8 may form a heterocycle with a nitrogen atom or a phosphorus atom. X1 is an anion derived from an inorganic or organic acid in which an acidic hydrogen ion is bonded to a halogen or oxygen, and C I B r
I-C I O 4BF BH
RSO HSO44 4
3ROPO (RO)
PO2H- (R in formula 32 represents an alkyl group, alkylaryl group, alkoxyalkyl group, or aryl group having about 1 to 25 carbon atoms)
Examples include anions such as

Examples of quaternary ammonium salts include tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetramethylammonium p-}luenesulfonate, tetramethylammonium sulfate, tetraethylammonium chloride, tetraethylammonium bromide,
Tetraethylammonium iodide, tetra n-butylammonium chloride, tetra n-butylammonium bromide, tetra n-butylammonium hydrogen sulfite, tetra n-butylammonium verchlorate, tetra n-butylammonium phosphate, tetra n-butylammonium acetate , tetra-n-butylammonium borohydride, decyltrimethylammonium bromide, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, penzyltrimethylammonium chloride, penzyltriethylammonium iodide, penzylhexadecyldimethylammonium chloride , phenyltriethylammonium chloride, benzyldimethylethylammonium chloride, (2-
methoxyethoxyethyl) ammonium chloride, choline chloride, hexadecylpyridinium bromide, 2,4.6-1-limethylpyridinium p-toluenesulfonate, 1,8-diazabicyclo(5.4.0)undecene-7-benzylammonium Examples include chloride, hexadecyltrimethylalkylphenoxypoly(ethyleneoxy)ethylammonium phosphate, and the like.

Examples of quaternary phosphonium salts include pendyltriphenylphosphonium chloride, methyltriphenylphosphonium bromide, methyltriphenylphosphonium sulfate, hexadecyltriphenylphosphonium bromide, ethyltriphenylphosphonium chloride, amyltriphenylphosphonium bromide, and tetran-
Examples include butylphosphonium bromide, tetraphenylphosphonium bromide, trioctylphenylphosphonium dimethyl phosphate, trioctylphenylphosphonium acetate, bromomethyltriphenylphosphonium bromide, allyltriphenylphosphonium bromide, and the like.

These quaternary ammonium salts or quaternary phosphonium salts can be used alone or in combination of two or more.

The amount of quaternary ammonium salt or quaternary phosphonium salt used is 0.1 to 10 parts by weight per 100 parts by weight of copolymer rubber.
Parts by weight, preferably 0.5 to 5 parts by weight. If the amount used is less than 0.1 part by weight, the vulcanization rate is low and a vulcanizate with satisfactory physical properties cannot be obtained, or it takes a long time to obtain a vulcanizate with satisfactory physical properties. When the amount exceeds 1 part by weight, the vulcanization rate becomes extremely high and processing stability and storage stability are impaired.

The vulcanized introduction product of the present invention comprises a copolymer rubber containing a quaternary ammonium salt or a quaternary phosphonium salt, and any reinforcing agents, fillers, stabilizers, plasticizers, and processing agents commonly known in the rubber industry. It is prepared by adding auxiliary agents and the like and mixing with a roll or a kneader such as a Banbury. The resulting composition is shaped into a desired shape and further vulcanized to form a final product. Vulcanization is usually carried out at a temperature of 120°C or higher, preferably 150 to 250°C, for 1 to 60 minutes. If necessary, further heat at a temperature of 150 to 200℃.
Post-vulcanization is carried out for ~24 hours.

The composition of the present invention has a high vulcanization rate, compared to when using a vulcanizing agent conventionally known as a vulcanizing agent for epoxy group-containing copolymer rubber, such as ammonium benzoate or zinc dimethyldithiocarbamate. In comparison, a vulcanizate with satisfactory mechanical strength and compression set can be obtained with a shorter vulcanization time, and the vulcanization time can be significantly shortened.

The vulcanizate obtained from the composition of the present invention has excellent heat aging resistance, oil resistance, compression set, and weather resistance, and has excellent properties such as packing, O
Various sealing materials such as rings, gaskets, oil seals, etc.
It can be widely and effectively used for various hoses, diaphragms, etc.

[Example] The present invention will be specifically explained below using examples.

In the following description, parts represent parts by weight, and % represents weight %.

A copolymer rubber having the composition shown in Table 1 was prepared by a conventional emulsion polymerization method.

(Examples 1 to 3 and Comparative Examples 1 to 3) 100 parts of each copolymer rubber shown in Table 2, 1 part of stearic acid, 50 parts of MAF carbon black, and the vulcanizing agent shown in Table 1. A predetermined amount was kneaded using an 8-inch oven roll to prepare a blend. The Mooney scorch time of the obtained compound was determined according to JISK-6300. The resulting compound was press-cured at 170°C for 20 minutes, and then post-vulcanized at 150°C in an oven for 4 hours to give a vulcanized product for 11 hours. The physical properties of the vulcanized product
Table 2 shows the results of the evaluation according to K-6301, and FIG. 1 shows the vulcanization curves of each formulation. Here, the vulcanization curve is
Using a Monsanto rheometer, AD1 was determined at a temperature of 170''C and a vibration angle of 3°.

(Examples 4 to 7) 100 parts of copolymer rubber A, 1 part of stearic acid, MA
Fifty parts of F carbon black and a predetermined amount of the vulcanizing agent listed in Table 3 were kneaded using an 8-inch oven roll to prepare a blend. The Mooney scorch time of the resulting formulation was measured according to JIS K-6300. The resulting compound was press-vulcanized at 170°C for 20 minutes, and further vulcanized in an oven at 150°C for 4 hours to obtain a vulcanized product. The physical properties of the obtained vulcanizate were determined according to JIS K-6.
Table 3 shows the results of evaluation according to 301.

(Examples 8 to 11, Comparative Example 4) 100 parts of each copolymer rubber shown in Table 4, 1 part of stearic acid, 50 parts of MAF carbon black, and the specified poison of the vulcanizing agent shown in Table 1 were heated in an 8-inch oven. A blend was prepared by kneading using a roll. The Mooney scorch time of the obtained formulation was determined according to JISK-6300. The resulting compound was press-vulcanized at 170°C for 20 minutes, and further vulcanized in an oven at 150°C for 4 hours to obtain a vulcanized product. 11 The physical properties of the vulcanized product are determined by JISK.
Table 4 does not show the results evaluated according to -6301.

[Effects of the Invention] As is clear from the above results, the composition of the present invention has a higher vulcanization rate and a shorter vulcanization time than the conventionally known vulcanization using ammonium benzoate as a vulcanizing agent. ! A vulcanized rubber having satisfactory physical properties between f and 6' is provided.

[Brief explanation of drawings]

FIG. 1 shows the vulcanization curves of the inclusions of Examples 1-3 and Comparative Examples 1-3.

Claims (1)

[Claims] (1) 1) Formula ▲ Numerical formula, chemical formula, table, etc. ▼ (Here, R^1 is hydrogen or a methyl group, R^2 is a cyano group-substituted alkyl group, n is an integer of 1 or more,
The numerical average value is 1-10. ) 0.5 to 99.9% by weight of acrylic ester or methacrylic ester of cyano group-containing caprolactone oligomer, 2
) 0.1 to 10% by weight of epoxy group-containing monomer, and 3
) Quaternary ammonium salts or quaternary phosphonium salts 0.1 to 1 to 100 parts by weight of a copolymer rubber having a polymer composition of 0 to 99.4% by weight of monomers copolymerizable with these.
A copolymer rubber vulcanized composition containing 0 parts by weight.