JPH083285A - Epoxy group-containing vulcanizable elastomer composition - Google Patents

Abstract

(57) [Summary] [Structure] An epoxy group-containing vulcanizable elastomer composition containing the following components (A) to (C). Component (A): Epoxy group-containing elastomer (B) Component: Thiol compound represented by the following chemical formula (1) (In the formula, R ₁ , R ₂ , R ₃ and R ₄ independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms.) (C) component: quaternary ammonium salt compound, quaternary phosphonium At least one compound selected from a salt compound and a phosphine compound represented by the following chemical formula (2) (In the formula, X represents hydrogen or an alkoxy group having 1 to 4 carbon atoms, and R ₅ and R ₆ independently represent an alkyl group having 1 to 4 carbon atoms.) Effect Mechanical Properties and Compression Permanence It has excellent distortion properties and a high vulcanization rate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an epoxy group-containing vulcanizable elastomer composition. More specifically, the present invention is excellent in mechanical properties such as tensile strength, elongation and hardness,
Moreover, the present invention relates to an epoxy group-containing vulcanizable elastomer composition having excellent compression set in a high temperature atmosphere and having a sufficiently high vulcanization rate.

[0002]

2. Description of the Related Art As a vulcanization system for an epoxy group-containing elastomer having an epoxy group as a crosslinking point, polyamine,
Diamine carbamate, organic ammonium carboxylate,
Dithiocarbamate or imidazoles,
Generally widely used. However, the epoxy group-containing elastomer using these vulcanization systems has a drawback that compression set is inferior, and long-term secondary vulcanization is required to improve the compression set. ing.

In order to solve these drawbacks, various studies have been made on a vulcanizing system which gives an epoxy group-containing elastomer excellent compression set properties. For example, JP-A-61-26620 and JP-A-63-57629 disclose a method of using an organic compound having a specific structure and a quaternary ammonium salt or a quaternary phosphonium salt in an epoxy group-containing elastomer. Is disclosed. However, recent requirements for compression set have become more severe, and it is desired to have excellent compression set even in a high temperature atmosphere of, for example, 180 ° C. or higher. Under these circumstances, no vulcanization system including the above-mentioned vulcanization system has been found which gives excellent compression set under such severe conditions and has a sufficiently high vulcanization rate.

[0004]

SUMMARY OF THE INVENTION The problems to be solved by the present invention are to solve the above problems and to have excellent mechanical properties.
Another object of the present invention is to provide an epoxy group-containing vulcanizable elastomer composition having excellent compression set even in a high temperature atmosphere of, for example, 180 ° C. or higher and having a sufficiently high vulcanization rate.

[0005]

That is, the present invention relates to an epoxy group-containing vulcanizable elastomer composition containing the following components (A) to (C). Component (A): Epoxy group-containing elastomer (B) Component: Thiol compound represented by the following chemical formula (1) (In the formula, R ₁ , R ₂ , R ₃ and R ₄ independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms.) (C) component: quaternary ammonium salt compound, quaternary phosphonium At least one compound selected from a salt compound and a phosphine compound represented by the following chemical formula (2) (In the formula, X represents hydrogen or an alkoxy group having 1 to 4 carbon atoms, and R ₅ and R ₆ independently represent an alkyl group having 1 to 4 carbon atoms.)

The component (A) of the present invention is an epoxy group-containing elastomer, specifically, (a) an epoxidized elastomer, or (b) an epoxy group-containing monomer 0.1 to 1.
0% by weight, preferably 0.5 to 3% by weight, and 90.0 to 99.9% by weight of at least one monomer having a terminal vinyl group or a terminal vinylidene group copolymerizable with the monomer. Examples thereof include epoxy group-containing elastomers obtained by polymerization by known methods such as emulsion polymerization, suspension polymerization, solution polymerization and bulk polymerization.

The epoxy group contained in the above epoxy group-containing monomer acts as a cross-linking point, and examples of the monomer include glycidyl acrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidyl ether, and meta. Examples thereof include acryl glycidyl ether, and among these, glycidyl acrylate and glycidyl methacrylate are particularly preferable.

As the monomer having a terminal vinyl group or a terminal vinylidene group copolymerizable with the epoxy group-containing monomer, acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate and n-octyl acrylate are used. , Methoxymethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, etc. are exemplified, as methacrylate, methacrylate corresponding to the above acrylate is exemplified, as vinyl ester, vinyl acetate, vinyl propionate, vinyl butyrate, etc. are exemplified, and vinyl ketone is exemplified. , Methyl vinyl ketone, ethyl vinyl ketone, and the like. Examples of vinyl aromatic compounds include styrene and α.
-Methylstyrene, vinyltoluene, etc. are exemplified, as conjugated dienes, butadiene, isoprene, etc. are exemplified, as α-monoolefins, ethylene, propylene, 1-butene, etc. are exemplified, and as a vinyl monomer having a hydroxyl group, β-hydroxyl ethyl acrylate,
4-hydroxyl butyl acrylate and the like are exemplified,
Examples of the vinyl or vinylidene monomer having a nitrile group include acrylonitrile, methacrylonitrile and β-cyanoethyl acrylate. These monomers can be used alone or in combination of two or more.

Specific examples of the component (A) include epoxy group-containing acrylate copolymer elastomer, epoxy group-containing ethylene-vinyl acetate copolymer elastomer, epoxy group-containing ethylene-acrylate copolymer elastomer, epoxy group-containing ethylene- Vinyl acetate-acrylate copolymer elastomer, epoxy group-containing ethylene-propylene copolymer elastomer, epoxy group-containing butadiene-acrylonitrile copolymer elastomer, epoxy group-containing acrylate-acrylonitrile copolymer elastomer, epoxy group-containing butadiene-styrene copolymer Examples thereof include a compounded elastomer, an epoxy group-containing butadiene-acrylonitrile-acrylate copolymer elastomer, and an epoxidized natural rubber. An epoxy group-containing monomer is one component. By copolymerization reaction, or not particularly limited as long as elastomers crosslinking points epoxy group obtained by epoxidizing an elastomer.

The component (B) of the present invention has the chemical formula (1)
Is a thiol compound represented by, as a specific example,
4,4'-thiodi-benzenethiol, bis (4-mercapto-3-methylphenyl) sulfide, 4,4'-
Thiodi (2,6-dimethylbenzenethiol), 4,
4'-thiodi (2-methyl-6-tert-butylbenzenethiol) and the like can be mentioned.

In the present invention, it is necessary to use the specific thiol compound represented by the chemical formula (1). Even if it is a thiol compound, it does not depend on the present invention, for example, 1,6-dimercaptohexane, 1,2-dimercapto-4-methylbenzene, 1,2-dimercapto-4-
The use of tert-butylbenzene or the like is inconvenient because loss of thiol compound due to evaporation and odor problems occur in the processing step.

The component (B) may be added and mixed at the time of the polymerization reaction of the component (A) or at the end of the polymerization reaction, or other compounding agents such as a reinforcing agent may be added to the elastomer by a kneader usually used in the rubber industry. You may add and mix together with it.

The amount of the component (B) used is 100 parts of the component (A).
It is usually 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight per part by weight, and a preferable range is appropriately set in view of vulcanization rate, mechanical properties of vulcanized product, compression set, and the like. To be selected. If the component (B) is too small, the crosslinking density may be low, while if the component (B) is too large, the crosslinking density will be too high, which is not practical.

The component (C) of the present invention is at least one of the quaternary ammonium salt compound, the quaternary phosphonium salt compound and the phosphine compound represented by the chemical formula (2).

Examples of the quaternary ammonium salt compound include compounds represented by the following chemical formula (4):
Examples of the quaternary phosphonium salt compound include compounds represented by the following chemical formula (5).

[0016]

In the formula, R _{7 to} R ₁₀ independently have 1 to 1 carbon atoms.
It represents a hydrocarbon radical having 25 carbon atoms. However, R
Two or three may be for forming a nitrogen atom or a phosphorus atom and heterocyclic structure of ₇ to R _10. Examples of the hydrocarbon group include an alkyl group, an aryl group, an alkylaryl group, a polyoxyalkylene group and the like.

X is an acidic hydrogen bond to halogen or oxygen.
With anions derived from inorganic or organic acids that are combined
And preferred are Cl, Br, I, HS
O_Four, H ₂PO_Four, R₁₁COO, R₁₁OSO₃, R₁₁S
O, R₁₁OPO₃H (R₁₁Is R₇~ R_TenSame as above char
Anion such as hydrogenated group).

Specific examples of the quaternary ammonium salt include tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide,
n-dodecyltrimethylammonium bromide, cetyldimethylbenzylammonium chloride, methylcetyldibenzylammonium bromide, cetyldimethylethylammonium bromide, octadecyltrimethylammonium bromide, cetylpyridinium chloride, cetylpyridinium bromide, 1,8-diaza-
Bicyclo (5,4,0) undecene-7-methylammonium methosulfate, 1,8-diaza-bicyclo (5,4,0) undecene-7-benzylammonium chloride, cetyltrimethylammoniumalkylphenoxypoly (ethyleneoxy) ethyl Phosphate,
Examples thereof include cetylpyridinium iodide, cetylpyridinium sulfate, tetraethylammonium acetate, trimethylbenzylammonium benzoate, trimethylbenzylammonium paratoluene sulfonate, trimethylbenzylammonium borate and the like.

Examples of the quaternary phosphonium salt are triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, triphenylbenzylphosphonium iodide, triphenylmethoxymethylphosphonium chloride, triethylbenzylphosphonium chloride, tricyclohexylbenzylphosphonium chloride, Examples include trioctylmethylphosphonium dimethyl phosphate, tetrabutylphosphonium bromide, trioctylmethylphosphonium acetate and the like.

Specific examples of the phosphine compound include tris- (2,6-dimethoxyphenyl) phosphine, tris- (2,6-diethoxyphenyl) phosphine, tris (2,6-din-propoxyphenyl) phosphine,
Tris- (2,6-diiso-propoxyphenyl) phosphine, tris- (2,6-dibutoxyphenyl) phosphine, tris- (2,4,6-trimethoxyphenyl) phosphine, tris- (2,4,4. 6-triethoxyphenyl) phosphine, tris- (2,4,6-trin
-Propoxyphenyl) phosphine, tris- (2,
4,6-tri-iso-propoxyphenyl) phosphine, tris- (2,4,6-tri-butoxyphenyl)
Examples include phosphine.

These compounds may be used either individually or in combination of two or more.

The amount of the component (C) to be used is appropriately selected within the preferable range from the viewpoints of vulcanization rate, processing stability, storage stability, mechanical properties of the vulcanized product, compression set, etc. )
It is usually 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, relative to 100 parts by weight of the component. If the amount of the component (C) is too small, the progress of vulcanization may be insufficient, while if the amount of the component (C) is too large, the vulcanization rate will be extremely high.
Processing stability and storage stability may be impaired.

In the present invention, the above component (A)
In addition to the component (C), one compound represented by the chemical formula (3)
It is preferable to contain the component (D) which is a compound having a structural unit represented by.

Specific examples of the component (D) include urea and N-
Methylurea, N-ethylurea, N, N-dimethylurea,
N, N-diethylurea, N, N'-diethylurea, N,
N'-ethylidene urea, N-acetyl urea, N-acetyl-N'-methyl urea, N, N'-dimethylol urea,
Aliphatic ureas such as tetramethylurea, carbamylurea and carbamoylcarbamic acid and their corresponding aliphatic thioureas, and phenylurea, N-ethyl-N '
-Phenylurea, N, N'-diphenylurea, N, N-
Diphenylurea, N-acetyl-N-phenylurea, N
-Aromatic ureas such as benzoylurea, tetraphenylurea, N, N-dimethyl-N, N'-dichlorophenylurea and the corresponding aromatic thioureas, and further ethyleneurea, glycolylurea, dimethylparaban Examples thereof include heterocyclic ureas such as acid, benzimidazolone, and 5-methyluracil, and heterocyclic thioureas corresponding thereto. These compounds may be used alone or in combination of two or more.

In the present invention, the component (D) is not essential. However, from the viewpoint of improving scorch stability, mechanical properties of the vulcanizate, compression set, etc., it is desirable to incorporate the component (D). The amount used is (A)
0.1 to 10 parts by weight based on 100 parts by weight of the component,
It is preferably 0.1 to 5 parts by weight. If the component (D) is too small, the effect of adjusting the vulcanization rate may not be sufficient,
On the other hand, if the amount of component (D) is too large, the vulcanization rate will be slow and it may not be practically preferable.

The epoxy group-containing vulcanizable elastomer composition of the present invention comprises the components (A) to (C), optionally the component (D), and a reinforcing agent commonly used in the rubber industry. It can be obtained by mixing a filler, a plasticizer, an antiaging agent, a stabilizer, a processing aid and the like with an ordinary kneader such as a roll or Banbury.

Further, the composition is molded into a shape suitable for the purpose and subjected to a vulcanization step to obtain a final product.

Vulcanization is usually carried out at a temperature of 120 ° C. or higher, preferably about 150 to 220 ° C. for 1 to 60 minutes. Furthermore, by performing secondary vulcanization at a temperature of about 150 to 200 ° C. for a relatively short time of 4 to 16 hours, the compression set in a high temperature atmosphere is greatly improved.

The epoxy group-containing vulcanizable elastomer composition obtained according to the present invention has a temperature (1
Not only at 50 ° C), but also at higher temperatures (for example, 180 ° C or higher), it has excellent compression set and mechanical properties. It can be widely and effectively used for materials (gaskets, packings, O-rings, oil seals), various hoses, various belts, and rolls.

[0031]

EXAMPLES The present invention will be described with reference to examples, but the present invention is not limited thereto. Examples 1 to 5 and Comparative Examples 1 to 2 As a component (A), an ethylene-acrylic acid ester-glycidyl methacrylate copolymer (38% by weight of ethylene,
Epoxy group-containing elastomer 10 composed of 60% by weight of methyl acrylate and 2% by weight of glycidyl methacrylate)
0 parts by weight, as shown in Table 1, and as a common composition, FEF carbon black (Shiast SO, a product of Tokai Carbon Co., Ltd.) 4
0 part by weight, 2 parts by weight of an amine anti-aging agent (Nogard 445 manufactured by Uniroyal Co., Ltd.), 1 part by weight of stearic acid and 0.5 part by weight of stearylamine were kneaded using an 8-inch roll to obtain a composition. The vulcanization rate of the composition was measured using an oscillating disk rheometer manufactured by Toyo Seiki Co., Ltd. under the condition of 170 ° C., and 90% vulcanization time t _C ′
(90) was calculated. In addition, each composition was press-vulcanized at 170 ° C. for 20 minutes, and further 185 ° C. in a gear oven.
Secondary vulcanization was performed for 4 hours. The vulcanized physical properties of each vulcanized product obtained by primary vulcanization and secondary vulcanization were measured according to JIS-K6301. The obtained results are shown in Table 1.

[0032]

[Table 1] ----------------------------------------------- Actual Example Ratio Comparison Example 1 2 3 4 5 1 2 Blend * 1 TDBT (B component) 2.4 2.4 3.0 2.8 2.4 CPCL (C component) 0.7 0.7 1.3 0.3 0.8 ODTMAB (C component) 1.5 DMPP (C component) 0.3 DPU (D component) 2.6 2.0 2.6 2.6 2.3 2.3 ICA (Other) 0.8 0.8 Measurement result Vulcanization rate t _c ^' (90) min 6.5 8.5 13.5 22.1 40.5 24.2 44.5 Primary vulcanization physical properties * 2 Tensile strength kgf / cm ² 161 167 162 171 124 143 144 Elongation% 430 500 470 480 380 550 620 Hardness JIS-A 60 60 64 63 55 58 56 Permanent set% 150 ℃ × 70hr 30 28 35 41-39 65 185 ℃ × 70hr 64 53 98 63 77 90 83 Secondary vulcanization physical properties * 3 Permanent set% 150 ℃ × 70hr 22 21 28 37-41 16 185 ℃ × 70hr 53 45 58 54 57 84 52 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−

* 1 Compounding TDBT: 4,4'-thiodi-benzenethiol CPCL: Cetylpyridinium chloride ODTMAB: Octadecyltrimethylammonium bromide DMPP: Tris- (2,6-dimethoxyphenyl) phosphine DPU: N, N'-diphenylurea ICA: isocyanuric acid The numbers in the table are parts by weight of each component per 100 parts by weight of component (A) * 2 Physical properties of primary vulcanization Physical properties after primary vulcanization at 170 ° C x 30 minutes * 3 Secondary addition Physical properties after vulcanization 170 ° C x 30 minutes (primary vulcanization) + 185 ° C x 4 hours (secondary vulcanization)

[0034]

Industrial Applicability As described above, according to the present invention, an epoxy group-containing vulcanizable elastomer composition having excellent mechanical properties, excellent compression set even in a high temperature atmosphere, and a sufficiently high vulcanization rate is obtained. I was able to provide things.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C08L 33/14 LHV (72) Inventor Tadaaki Nishiyama 1-5 Anesaki Kaigan, Ichihara, Chiba Sumitomo Chemical Co., Ltd. Within the corporation

Claims (2)

[Claims] 1. An epoxy group-containing vulcanizable elastomer composition containing the following components (A) to (C). Component (A): Epoxy group-containing elastomer (B) Component: Thiol compound represented by the following chemical formula (1) (In the formula, R ₁ , R ₂ , R ₃ and R ₄ independently represent hydrogen or an alkyl group having 1 to 4 carbon atoms.) (C) component: quaternary ammonium salt compound, quaternary phosphonium At least one compound selected from a salt compound and a phosphine compound represented by the following chemical formula (2) (In the formula, X represents hydrogen or an alkoxy group having 1 to 4 carbon atoms, and R ₅ and R ₆ independently represent an alkyl group having 1 to 4 carbon atoms.) 2. An epoxy group-containing vulcanizable elastomer composition containing the components (A) to (C) according to claim 1 and the following component (D). Component (D): a compound having one structural unit represented by the following chemical formula (3) in the molecule (In the formula, Z represents an oxygen atom or a sulfur atom.)