JPH0710965A - Epoxidized elastomer composition - Google Patents

Abstract

PURPOSE:To decrease the compression set of an epoxidized elastomer by mixing it with an imidazole compd. of a specific formula, an org. compd. having specific groups, and a quaternary ammonium salt. CONSTITUTION:The elastomer with a decreased compression set is obtd. by mixing 100 pts.wt. elastomer having an epoxy group content of 0.1-5wt.% and formed from ethylenically unsatd. compds. such as n-butyl acrylate and vinyl acetate and an epoxy compd. such as glycidyl methacrylate with 0.2-5 pts.wt. imidazole compd. of formula I (wherein R1 is 1-17C alkyl, aryl, amino, etc.; R2 is H, 1-17C alkyl, aryl, etc.; and R3 and R4 are each H, 1-17C alkyl, cyano, carboxyl, etc.) (e.g. methylimidazole), 0.1-5 pts.wt. org. compd. having at least two groups of formula II (e.g. parabanic acid), and 0.1-5 pts.wt. quaternary ammonium salt (e.g. tetrabutylammonium bromide).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vulcanized product of an elastomer having an epoxy group. More specifically, it relates to an elastomer vulcanizate having high-speed vulcanizability and processing safety, and having improved compression set.

[0002]

2. Description of the Related Art As a vulcanizing agent for an elastomer having an epoxy group, a thermally decomposable ammonium salt, a metal salt of dithiocarbamic acid, an amine, a polyamine salt and the like are generally widely used. However, the vulcanized products of elastomers using these vulcanizing agents have a relatively large compression set, and further improvement is desired. Further, in the process of manufacturing an elastomer component, high-speed vulcanization for shortening the vulcanization time is desired from the viewpoint of improving productivity and saving energy.

Japanese Unexamined Patent Publication (Kokai) No. 63-132925 discloses a vulcanizing composition using an imidazole compound and a urea derivative compound having a urea bond in an epoxy group-containing elastomer, and Japanese Unexamined Patent Publication (Kokai) No. 63-57628. JP-A No. 2003-242242 discloses a vulcanizable elastomer composition using an organic compound having two or more bonds represented by the following general formula (3) and a quaternary ammonium salt in an epoxy group-containing elastomer. Not enough in permanent set and vulcanization rate.

[Chemical 3] (X and Y in the formula both represent an oxygen atom or a sulfur atom, or one represents an oxygen atom and the other represents a sulfur atom.)

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have disclosed a method of vulcanizing an elastomer composition having an epoxy group, for the purpose of improving compression set while ensuring high-speed vulcanizability and processing safety. As a result of various studies on the above, the present invention has been achieved.

[0005]

Means for Solving the Problems In the present invention, 100 parts by weight of an epoxy group-containing elastomer, an imidazole compound represented by the following general formula (1) 0.2-5.
0 parts by weight, 0.1 to 5.0 parts by weight of an organic compound having two or more partial structural formulas represented by the following formula (2), and 0.1 to 5.0 parts by weight of a quaternary ammonium salt. It is an elastomer composition having an epoxy group characterized by containing.

[Chemical 4] (In the formula, R ₁ represents an alkyl group having 1 to 17 carbon atoms, a substituted alkyl group, an aryl group, a substituted aryl group, an amino group, a cyano group or a mercapto group, and R ₂ represents a hydrogen atom or a carbon number 1
To 17 alkyl groups, substituted alkyl groups, aryl groups, and substituted aryl groups. R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 17 carbon atoms or a substituted alkyl group, a cyano group, a hydroxyalkyl group, a carboxyl group, a thiocarbomoyl group, and an imidazolyl group. )

[Chemical 5]

The present invention will be described in detail below. The elastomer in the present invention contains 0.1 to 5.0% by weight of a monomer having an epoxy group such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and methacryl glycidyl ether as a cross-linking site,
Preferably, 0.5 to 3% by weight of copolymerization is desirable.

Examples of the monomer copolymerizable with the monomer having an epoxy group include an ethylenically unsaturated compound having acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester as the main components and copolymerizable as other components.

Examples of alkyl acrylates include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-methylpentyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl acrylate, n-octadecyl acrylate, cyanomethyl acrylate, 1-cyanoethyl acrylate, 2-cyanoethyl acrylate, 1-cyanopropyl acrylate, 2-cyanopropyl acrylate , 3-cyanopropyl acrylate,
4-cyanobutyl acrylate, 6-cyanohexyl acrylate, 2-ethyl-6-cyanohexyl acrylate, 8-cyanooctyl acrylate and the like can be mentioned.

Also included are acrylic acid alkyl esters represented by the following general formula (4).

[Chemical 6] (However, R ₁ is a hydrogen atom or a methyl group, R ₂ is an alkylene group having 3 to 20 carbon atoms, R ₃ is a hydrocarbon group having 1 to 20 carbon atoms or a derivative thereof, and n is an integer of 1 to 20. .)

Examples of the alkoxyalkyl acrylate include 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2- (n-propoxy) ethyl acrylate, 2- (n-butoxy) ethyl acrylate, 3-methoxypropyl acrylate. , 3-ethoxypropyl acrylate, 2- (n-propoxy) propyl acrylate, 2- (n-butoxy) propyl acrylate and the like.

As the copolymerizable ethylenically unsaturated compound, various compounds can be used if necessary, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, 2-pentenoic acid and maleic acid. Carboxy compounds such as fumaric acid and itaconic acid, 1,1-dihydroperfluoroethyl (meth) acrylate, 1,1-dihydroperfluoropropyl (meth) acrylate, 1,
1,5-trihydroperfluorohexyl (meth) acrylate, 1,1,2,2-tetrahydroperfluoropropyl (meth) acrylate, 1,1,7-trihydroperfluoroheptyl (meth) acrylate, 1,1
Fluorinated acrylic acid esters such as dihydroperfluorooctyl (meth) acrylate and 1,1-dihydroperfluorodecyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth ) Hydroxy acrylates such as acrylates, tertiary amino acrylates such as diethylaminoethyl (meth) acrylate, dibutylaminoethyl (meth) acrylate, methacrylates such as methyl methacrylate and octyl methacrylate, alkyl vinyls such as methyl vinyl ketone Vinyl and allyl ethers such as ketones, vinyl ethyl ether, allyl methyl ether, styrene, α-methyl styrene, chlorostyrene, vinyl toluene Vinyl aromatic compounds such as,
Examples thereof include vinyl nitrile such as acrylonitrile and methacrylonitrile, ethylene, propylene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, vinyl acetate, vinyl propionate, and alkyl fumarate.

Next, as the imidazole compound in the present invention, 1-methylimidazole, 1,2-dimethylimidazole, 1-methyl-2-ethylimidazole,
1-benzyl-2-ethylimidazole, 1-benzyl-2-ethyl-5-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-phenylimidazole-trimellitic acid salt, 1-aminoethylimidazole , 1-aminoethyl-2-methylimidazole, 1-aminoethyl-2-ethylimidazole,
1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-methyl Imidazole trimellitate, 1-cyanoethyl-2-phenylimidazole trimellitate,
1-Cyanoethyl-2-ethyl-4-methylimidazole trimellitate, 1-Cyanoethyl-2-undecyl-imidazole trimellitate, 2,4-diamino-6
-[2'-Methylimidazolyl- (1) '] ethyl-s
-Triazine / isocyanuric acid adduct, 1-cyanoethyl-2-phenyl-4,5-di- (cyanoethoxymethyl) imidazole, N- (2-methylimidazolyl-
1-ethyl) urea, N, N'-bis- (2-methylimidazolyl-1-ethyl) urea, 1- (cyanoethylaminoethyl) -2-methylimidazole, N, N '-[2
-Methylimidazolyl- (1) -ethyl] -adivoyldiamide, N, N '-[2-methylimidazolyl-
(1) -Ethyl] -dodecanedioyldiamide, N,
N '-[2-methylimidazolyl- (1) -ethyl]-
Eicosane dioil diamide, 2,4-diamino-6-
[2'-Methylimidazolyl- (1) ']-ethyl-s
-Triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1) ']-ethyl-s-triazine, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 1,3- Examples thereof include dibenzyl-2-methylimidazolium chloride.

The amount of addition of these is preferably 0.2 to 5.0 parts by weight with respect to 100 parts by weight of the elastomer, and is 0.1.
If it is less than 2 parts by weight, the physical properties of the vulcanizate are not sufficient and
If it exceeds the weight part, processing safety may be impaired.

The organic compound having two or more partial structural formulas represented by the following formula (2) in the molecule of the present invention includes a heterocyclic compound, an aromatic compound or an aliphatic compound. The term “two or more partial structural formulas” includes the case where the partial structural formulas are separated from each other and the case where the partial structural formulas are adjacent to each other. Further, the partial structural formula may be present outside the ring as a substituent of the heterocyclic compound.

[Chemical 7]

As the heterocyclic compound, parabanic acid, alloic acid, alloxanthin, alloxan-5-oxime,
Barbituric acid, 5-hydroxybarbituric acid, 5-benzalbarbituric acid, 5-aminobarbituric acid, 5-hydroxyiminobarbituric acid, 5,5-diethylbarbituric acid, 5-ethyl-5-phenylbarbi Toluic acid (barbital), 5- (1-methylbutyl) -5- (allyl)
Examples thereof include barbituric acid, 5,5-diallylbarbituric acid, isocyanuric acid and pseudouric acid.

Examples of the aromatic compound include pyromellitic acid diimide, mellitic acid triimide, 1,4,5,8-naphthaldiimide and the like.

The aliphatic compounds include triuret, 1
-Methyl triuret, 1,1-diethyl triuret, tetrauret and the like.

The addition amount of these is preferably 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the elastomer, and is 0.1.
If it is less than 1 part by weight, the vulcanization rate and compression set will not be sufficiently improved, and if it exceeds 5.0 parts by weight, moldability may be problematic.

As the quaternary ammonium salt in the present invention, those represented by the following general formula (5) are used.

[Chemical 8] (In the formula, R _{1 to} R ₄ are an alkyl group having 1 to 25 carbon atoms, an alkoxy group, an aryl group, an alkylaryl group, an aralkyl group or a polyoxyalkylene group, and 2 to 3 of these have a heterocyclic structure. It can also be formed. X is an anion of a halogen atom and includes Cl, Br, I, etc.)

Examples of the quaternary ammonium salt are tetraethylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide, cetyltrimethylammonium bromide, n-dodecyltrimethylammonium bromide and cetyldimethylbenzylammonium chloride. , Methylcetyldibenzylammonium bromide, cetyldimethylethylammonium bromide, octadecyltrimethylammonium bromide, cetylpyridinium chloride, cetylpyridinium bromide, 1,8-diaza-bicyclo (5,4,
0) Undecene-7-benzylammonium chloride, cetylpyridinium iodide and the like.

The addition amount of these is preferably 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the elastomer, and is 0.1.
If it is less than 1 part by weight, the vulcanization rate and compression set are not sufficiently improved, and if it exceeds 5.0 parts by weight, processing stability may be impaired.

In the present invention, for the purpose of adjusting the vulcanization rate, a curing agent for epoxy resin, such as a pyrolyzed ammonium salt, an organic acid, an acid anhydride, amines, sulfur and a sulfur compound, is further added. It can be added as long as the effect is not diminished.

Further, the elastomer vulcanizate of the present invention is molded and vulcanized by adding a reinforcing agent, a filler, a plasticizer, etc. to the elastomer composition according to the purpose when it is put to practical use. be able to.

The kneading and vulcanization of the elastomer composition according to the present invention can be carried out by the methods generally used in the rubber industry.

Since the elastomer composition of the present invention is excellent in heat resistance, oil resistance and severe durability, it is suitable for industrial parts such as belts, hoses, oil seals, gaskets, diaphragms, etc., and particularly for automobiles with strict quality assurance. It can be expected that the reliability of the parts will be improved.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 40 kg of a mixed solution of 10 kg of vinyl acetate and 30 kg of n-butyl acrylate in a polymerization vessel, 43 kg of a 4% by weight aqueous solution of partially saponified polyvinyl alcohol, and 60% of sodium acetate.
0 g and glycidyl methacrylate 600 g were added and well mixed in advance with a stirrer to prepare a uniform suspension. After substituting the inside of the polymerization vessel with nitrogen gas, ethylene monomer was injected under pressure from above to adjust the pressure at a polymerization temperature of 45 ° C. to 50 kg / cm ² . Subsequently, a polymerization initiator aqueous solution was separately added from another injection port, and polymerization was performed for about 10 hours.

Subsequently, unreacted monomers in the produced polymer emulsion are removed, and a 3 wt% borax aqueous solution is added to coagulate the emulsion, followed by washing, dehydration and drying (120 to 13).
After 20 minutes on a roll at 0 ° C., a sheet-shaped elastomer having an epoxy group was obtained.

Next, according to the formulation shown in Table 1, kneading was performed using a 6-inch roll to prepare a sheet having a thickness of 2.3 mm, and this sheet was press-vulcanized at 170 ° C. × 170 ° C.
After 20 minutes, a test piece for evaluating the physical properties of the elastomer vulcanizate was prepared. The physical property test was performed according to JIS K6301, and the results are shown in Table 2.

[0029]

[Table 1] (Note) 1) Uniroyal anti-aging agent 2) Tokai Carbon Co., Ltd. Seast # 116

[0030]

[Table 2]

[0031]

As is apparent from the examples, the epoxy group-containing elastomer composition of the present invention has a high vulcanization rate and an improved compression set.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hideki Hirano 6 Goi Minamikaigan, Ichihara City, Chiba Denki Kagaku Kogyo Co., Ltd. Chiba Factory

Claims (1)

[Claims] 1. An elastomer 100 having an epoxy group.
Parts by weight, 0.2 to 5.0 parts by weight of an imidazole compound represented by the following general formula (1), and an organic compound 0.1 having two or more partial structural formulas represented by the following formula (2). ~ 5.
0 parts by weight, and quaternary ammonium salt 0.1-5.0
An elastomer composition having an epoxy group, characterized in that the elastomer composition contains a part by weight. [Chemical 1] (In the formula, R ₁ represents an alkyl group having 1 to 17 carbon atoms, a substituted alkyl group, an aryl group, a substituted aryl group, an amino group, a cyano group or a mercapto group, and R ₂ represents a hydrogen atom or a carbon number 1
To 17 alkyl groups, substituted alkyl groups, aryl groups, and substituted aryl groups. R ₃ and R ₄ represent a hydrogen atom, an alkyl group having 1 to 17 carbon atoms or a substituted alkyl group, a cyano group, a hydroxyalkyl group, a carboxyl group, a thiocarbomoyl group, and an imidazolyl group. ) [Chemical 2]