JPS5915356B2 - Vulcanizable blend rubber composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to vulcanizable blend rubber compositions.

More specifically, the present invention relates to a vulcanizable composition related to a co-vulcanization system of a blend rubber comprising a halogen-containing elastomer and a 3-carboxyl group-containing elastomer. Regarding the co-vulcanization system of blend rubber consisting of a halogen-containing elastomer and a carboxyl group-containing elastomer, JP-A-52-
It is described in Publication No. 81356. This vulcanization system consists of metal oxy compounds such as alkali metal salts of organic weak acids or non-alkali metal oxides, hydroxides, carbonates, and quaternary ammonium salts as vulcanization accelerators, monofunctional tertiary Consists of amines or guanidines. When this vulcanization system is used, a vulcanizate can be obtained that exhibits relatively excellent physical properties in terms of heat aging resistance, zero compression set, etc.
Note that there are many points in which improvements are required in terms of vulcanization characteristics and other properties. For example, when a quaternary ammonium salt is used as a vulcanization accelerator, rapid hardening, heat aging resistance,
Compression Permanence 5 Although it is excellent in terms of distortion, it has significant scorch properties and is inferior in processing safety and storage stability, which poses a major problem in practical use. In addition, when monofunctional tertiary amines or guanidines are used as vulcanization accelerators, scorch resistance is relatively good, but the vulcanization rate is rather slow, heat aging resistance, compression set, etc. The physical properties of these materials cannot necessarily be said to be fully satisfactory. Furthermore, regarding co-vulcanization of epihalohydrin elastomer and carboxyl group-containing nitrile rubber, 5 is 1,8-diazabicyclo[5,
4,0] By using a co-vulcanization system consisting of undecou-7-ene or its weak acid salt and a metal oxy compound acid acceptor, a vulcanizate having useful properties can be obtained.
It is described in Japanese Patent Application Laid-Open No. 52-32948.

o However, in this vulcanization system, although scorch resistance can be controlled by selecting a weak acid, physical properties such as heat aging resistance and compression set are not at a satisfactory level. The present inventor has discovered that halogen-containing elastomer and cal-5
When co-vulcanized with a boxyl group-containing elastomer, it has good scorch resistance and even better properties than the previously known vulcanization systems in terms of rapid curing, heat aging resistance, and compression set. As a result of various studies in search of a vulcanization system with
In the vulcanization system described in JP-A-52-81356, by using a quaternary phosphonium compound in place of the quaternary ammonium salt, the blended rubber is efficiently co-vulcanized, resulting in high tensile strength and low A vulcanizate with good physical properties such as compression set and a high level of heat aging resistance is obtained, and this vulcanization system also has excellent scorch resistance, processing stability and storage stability. It has been found that it has very advantageous properties.

Therefore, the present invention relates to a vulcanizable blend rubber composition, and this vulcanizable blend rubber composition comprises (a) a halogen-containing elastomer, (b) a carboxyl group-containing elastomer, (
c) at least one metal oxy compound selected from the group consisting of an alkali metal salt of an organic weak acid and a non-alkali metal oxide, hydroxide or carbonate, and (d) a quaternary phosphonium compound. .

The halogen-containing elastomer, which is one component of the blended rubber, can be obtained by polymerization of halogen-containing polymerizable monomers or by halogenation reaction of a polymer.

Particularly preferred halogen-containing elastomers include, for example, the following. (1) (a) A small group selected from the group consisting of nearkyl acrylates in which the alkyl group has 1 to 8 carbon atoms, and alkoxyalkyl acrylates in which the alkyl group and the alkylene group each have 1 to 4 carbon atoms. (b) about 20-0.1% by weight of an active halogen-containing polymerizable monomer;
) A halogen-containing acrylic elastomer obtained by copolymerizing about 30 to 0% by weight of at least one other polymerizable monomer that can be copolymerized with these polymerizable monomers.

Halogen-containing acrylic elastomers can be produced by any conventionally known copolymerization method for acrylic elastomers, but are preferably produced by suspension polymerization or emulsion polymerization.

Examples of the acrylate of the comonomer component (a) forming the halogen-containing acrylic elastomer include methyl acrylate, ethyl acrylate, n- or iso-propyl acrylate, n- or iso-butyl acrylate, n-hexyl acrylate, 2- Alkyl acrylates such as ethylhexyl acrylate, n-octyl acrylate and their substituted products 2-cyanoethyl acrylate, methoxymethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 3 - an alkoxyalkyl acrylate such as methoxypropyl acrylate is used;
Among these, ethyl acrylate, n-butyl acrylate, 2-methoxyethyl acrylate, and 2-ethoxyethyl acrylate are particularly preferred.

The reason why the alkyl group of the alkyl acrylate is limited to 1 to 8 carbon atoms, and the alkyl group and alkylene group of the alkoxyalkyl acrylate are limited to 1 to 4 carbon atoms, respectively, is that if the number of carbon atoms increases more than this, there will be no benefit. This is because the balance between the low-temperature properties and oil resistance of the acrylic elastomer vulcanizate produced by the acrylic elastomer vulcanizate cannot be satisfied.

One or more of these acrylates are used in a proportion of about 50 to 99.8%, preferably about 75 to 99.5%, of the total monomer weight, and particularly balanced low temperature When properties and oil resistance are desired, alkoxyalkyl acrylates are preferably used in combination with alkyl acrylates in a proportion of about 15 to 65%. As the active halogen-containing polymerizable monomer of the comonomer component (b),
For example, vinyl chloroacetate, vinyl chloropropionate,
Allyl chloroacetate and other alkenyl esters of α- or β-halogen-substituted aliphatic monocarboxylic acids, α- or β-chloroethyl acrylate, chloromethyl acrylate, chloromethyl methacrylate, α,β-dichloroethyl acrylate and others Haloalkyl esters of acrylic or methacrylic acid, chloromethyl vinyl ether, chlorethyl vinyl ether and other haloalkyl alkenyl ethers, chlorethyl vinyl ketone and other haloalkyl alkenyl ketones, chloracetoxyethyl acrylate, chloracetoxyethyl methacrylate, chloracetoxypropyl acrylate, chlor Acetoxypropyl methacrylate and other haloacetoxyalkyl esters of acrylic or methacrylic acid, vinylbenzyl chloride, bis(chloromethyl)styrene, chloromethylmethylstyrene and other halomethylstyrenes, chloracetamide methyl acrylamide, chloracetamide methyl methacrylamide, chlor Acetylcarbamoyloxyethyl acrylate, chloracetylcarbamoyloxypropyl acrylate, chloracetoxyhydroxypropyl acrylate, chloracetoxyhydroxypropyl methacrylate, chloracetoxyhydroxypropyl allyl ether, vinylbenzylchloroacetate and other radically copolymerizable unsaturated compounds with haloacetyl groups etc. are used.

One or more of these active halogen-containing monomers are used in an amount of about 20 to 0.1%, preferably about 1.0 to 0.5% of the total monomer weight. Comonomer component (
Other comonomers of c) include, for example, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile,
Styrene, α-methylstyrene, vinyl acetate, ethyl vinyl ether, butyl vinyl ether, methyl methacrylate, ethyl methacrylate, diethyl maleate, dibutyl maleate, divinylbenzene, ethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, allyl methacrylate , allyl alcohol, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, etc. are used.

One or more of these comonomers are used in an amount of about 30 to 0%, preferably about 20 to 0%, of the total weight of the comonomers. Acrylic elastomer copolymerized with about 2 to 20% by weight of acrylonitrile or methacrylonitrile provides a vulcanizate with superior high tensile strength,
In addition, acrylic elastomers copolymerized with a small amount (preferably about 2% by weight or less) of polyene monomers such as divinyl compounds have better roll processability and extrusion properties, so they are compatible with carboxyl group-containing elastomers. Depending on the blend ratio, these properties will be of particular benefit.

Furthermore, in the case of acrylic elastomers obtained by emulsion polymerization, by copolymerizing a small amount (preferably 0.5 to 5% by weight) of styrene or α-methylstyrene, very little coagulation can be achieved. In other words, it enables a copolymerization reaction with excellent polymerization stability. 2) (d) about 30-80% by weight of ethylene, (e) about 20-0.1% by weight of an active halogen-containing polymerizable monomer, (f) from 1 to 1 alkyl group;
about 10-70% by weight of an alkyl acrylate or alkyl methacrylate having 4 carbon atoms and (g)
Halogen-containing ethylene-acrylate elastomer obtained by copolymerizing about 30 to 0% by weight of at least one other polymerizable monomer that can be copolymerized with these polymerizable monomers.Halogen-containing ethylene-acrylate elastomer. One is, for example, the high-pressure polymerization method described in US Pat. No. 3,350,372 and the method described in J. POlymerSci RePOlym
erChemistryEd. , Volume 15, No. 1431~
It can be produced by the low pressure polymerization method described on page 1439 (1977).

The active halogen-containing polymerizable monomers of the comonomer component (e) forming the halogen-containing ethylene-acrylate elastomer include one or more of the same as the comonomer component (b). Approximately 20-0.1 of monomer weight
%, preferably about 10 to 0.5 (fl).

As the alkyl acrylate or alkyl methacrylate of the comonomer component (f), methyl acrylate, ethyl acrylate, n- or iso-propyl acrylate, n- or iso-butyl acrylate or the corresponding methacrylate is used. The copolymers obtained by copolymerizing ethylene with acrylates and/or methacrylates can be prepared in any desired proportions, but for the purpose of the present invention, copolymers are not suitable for the purpose of the present invention. About 30-80%, preferably about 40-70% by weight of ethylene as polymer component (d) and about 70-10% of alkyl acrylate or alkyl methacrylate as polymer component (f).
% by weight, preferably about 60-20% by weight, must be copolymerized in such proportions. Further, as the comonomer component (g), the comonomer component (c
) is used. (3) Epihalohydrin elastomer made of a homopolymer or copolymer of epihalohydrin The epihalohydrin elastomer may be a homopolymer of epichlorohydrin or epibromohydrin or a polymerizable monomer copolymerizable therewith, such as ethylene oxide or propylene. oxide, butylene oxide, cyclohexene oxide, butadiene monoxide,
Epoxides such as ethyl glycidyl ether, allyl glycidyl ether, tetrahydrofuran, trioxane, ethyl isocyanate, phenyl isocyanate,
Examples include copolymers with isocyanates such as 2,4-tolylene diisocyanate.

(4) Chlorinated polyethylene rubber (5) Chloroprene rubber (6) Halogenated butyl rubber The carboxyl group-containing elastomer, which is the other component of the blended rubber, is obtained by copolymerizing (7) a carboxyl group-containing monomer. Carboxyl group-containing acrylic elastomer, (8) carboxyl group-containing ethylene-acrylate elastomer, (9) carboxyl group-containing ethylene-acetic acid, vinyl elastomer, a0) carboxyl group-containing butadiene-acrylonitrile rubber, etc. are suitable, but the carboxyl group-containing monomer Other carboxyl group-containing elastomers obtained by copolymerization of other carboxyl group-containing elastomers, carboxyl group-containing elastomers obtained by hydrolysis of polymers having groups that can be hydrolyzed to produce carboxyl groups,
Any of the carboxyl group-containing elastomers obtained by both of these methods can be similarly used.

(7) The carboxyl group-containing elastomer obtained by copolymerizing the carboxyl group-containing monomer contains about 20 to 0.1% by weight of the carboxyl group-containing monomer and about at least one polymerizable monomer. 80 to 99.9% by weight.
The carboxyl group-containing monomer used in the copolymerization may be any monomer that can be copolymerized.

Usually, the carboxyl group-containing monomer is a monomer containing an olefinic double bond, and is copolymerized by a radical polymerization method. Examples of these carboxyl group-containing monomers include acrylic acid, methacrylic acid, ethacrylic acid, β,
β-dimethylacrylic acid, crotonic acid, vinyl acetic acid, 2
Methyl-2-butenoic acid, 2-pentenoic acid, 2-hexenoic acid, 3-ethyl-2-pentenoic acid, 2-heptenoic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, 2-norbornene-5-carboxylic acid Examples include cinnamic acid, monomethyl maleate, monoethyl maleate, and monobutyl maleate. Among these, acrylic acid, methacrylic acid, cinnamic acid, monomethyl maleate, monoethyl maleate, and monobutyl maleate are particularly preferred. The polymerizable monomer is a monomer having a vinyl group or a vinylidene group, and includes methyl acrylate, ethyl acrylate, n
- acrylates and corresponding methacrylates such as butyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, etc.; vinyl acetate,
Vinyl esters and allyl esters such as vinyl propionate, vinyl butyrate, allyl acetate, etc.; vinyl ketones such as methyl vinyl ketone, propyl vinyl ketone, etc.; vinyl methyl ether, vinyl ethyl ether,
Vinyl ethers and allyl ethers such as vinyl isobutyl ether, allyl methyl ether, etc.; vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, etc.; butadiene, isoprene, 2-isopropyl-1,3-butadiene, etc. Najien;
α-monoolefins such as ethylene, propylene, 1-butene, etc.; divinylbenzene, divinyl ether,
Polyenes such as diethylene glycol diacrylate, allyl methacrylate, etc.; allyl alcohol, β-
Vinylidene monomers containing hydroxyl groups such as hydroxyethyl acrylate, 4-hydroxybutyl acrylate, β-hydroxyethyl methacrylate, etc.; vinyl monomers containing nitrile groups such as acrylonitrile, methacrylonitrile, β-cyanoethyl acrylate, etc. is included.

Combinations of two or more of these monomers may also be used. The most preferred examples of carboxyl group-containing elastomers obtained by copolymerizing carboxyl group-containing monomers include the following.

(h) at least one acrylate selected from the group consisting of alkyl acrylates in which the alkyl group has 1 to 8 carbon atoms and alkoxyalkyl acrylates in which the alkyl group and the alkylene group each have 1 to 4 carbon atoms; 50 to 99.9% by weight, (1) about 20 to 0.1% by weight of carboxyl group-containing monomer, and (j)
A carboxyl group-containing acrylic elastomer obtained by copolymerizing about 30 to 0% by weight of at least one other polymerizable monomer that can be copolymerized with these monomers. Although it can be produced by any conventionally known polymerization method, for example, JP-A-51-144,4
No. 84, U.S. Patent No. 3,450,681,
Encyclopedia of Polymer Science
and Technology 7, Vol. 1, pp. 226-241 (1
It is produced by following the suspension polymerization method and emulsion polymerization method described in 964) and others.

The comonomer component (h) used to prepare the carboxyl group-containing acrylic elastomer is the same as the comonomer component (a).

As the carboxyl group-containing monomer of the comonomer component (1), the various monomers mentioned above are used, and among these, acrylic acid, methacrylic acid, cinnamic acid, vinyl acetic acid, monomethyl maleate, maleic acid, etc. Monoethyl acid and monobutyl maleate are preferred. One or more of these carpoxyl group-containing monomers account for about 2 of the total monomer weight.
It is used in a proportion of 0 to 0.1%, preferably about 10 to 0.5%. Further, as the comonomer component (j), the same one as the comonomer component (c) is used.

(8) (k) about 30 to 80% by weight of ethylene, (1) about 20 to 0.1% by weight of a carboxyl group-containing monomer, (e) an alkyl acrylate in which the alkyl group has 1 to 4 carbon atoms, and About 70-10% by weight of at least one acrylate selected from the group consisting of alkyl methacrylates
and (n) carboxyl group-containing ethylene acrylate elastomer carboxyl group-containing ethylene acrylate obtained by copolymerizing about 30 to 0% by weight of at least one other polymerizable monomer that can be copolymerized with these monomers. Elastomers can be made, for example, by high pressure polymerization methods as described in US Pat. No. 3,850,872.

Furthermore, in the aforementioned Japanese Patent Application Laid-open No. 5045,031, butenedionic acid monoester (maleic acid monoester)
A carboxyl group-containing ethylene-acrylate elastomer is described in which the carboxyl group-containing monomer is a carboxyl crosslinking site monomer. The comonomer components (1), (- and (n) are the comonomer components (1), (f) and (c), respectively.
) is used.

]) (0) about 30 to 80% by weight of ethylene, (p) about 20 to 0.1% by weight of a carboxyl group-containing monomer, (q) about 10 to 70% by weight of vinyl acetate, and (r) these monomers. at least one other polymerizable monomer copolymerizable with about 30
Carboxyl group-containing ethylene monoacetate vinyl elastomer obtained by copolymerizing ethylene monoacetate vinyl elastomer with carboxyl group-containing ethylene monoacetate vinyl elastomer obtained by copolymerizing ethylene monoacetate vinyl elastomer with a carboxyl group of 0% to 0% by weight. It is obtained by copolymerization with a reaction medium such as tertiary butanol under high pressure, for example in an autoclave, in the presence of a radical initiator such as butyronitrile.

The copolymer obtained by copolymerization of ethylene and vinyl acetate can have any proportion composition desired, but for the purposes of the present invention the weight proportion of ethylene should be in the range of about 30-80%. . Therefore, (0) ethylene about 30 to 80
(q) Vinyl acetate is copolymerized at a ratio of about 70 to 10 weight %, preferably about 60 to 20 weight %. As the carboxyl group-containing monomer of the comonomer component (p), the various ones mentioned above can be used. Among them, acrylic acid, methacrylic acid, maleic acid, maleic acid monoalkyl ester, cinnamic acid, and itaconic acid are particularly preferred. One or more of these carboxyl group-containing monomers are used in a total amount of about 20 to 0.1% by weight, preferably about 10 to 0.5% by weight of the total comonomer. The other comonomers of the comonomer component (r) may be the same as those of the comonomer component (c). Carboxyl group-containing butadiene-acrylonitrile rubber obtained by copolymerizing about 20% to 0.1% by weight of a carboxyl group-containing monomer Carboxyl group-containing butadiene-acrylonitrile rubber is usually called carboxylated NBR. , obtained by copolymerizing a carboxyl group-containing monomer such as acrylic acid, methacrylic acid, itaconic acid, etc. in a copolymerization reaction of butadiene and acrylonitrile.

Examples of the metal oxy compound as the vulcanization component (c) of the vulcanization system according to the present invention include aliphatic carbon compounds such as sodium stearate, potassium stearate, sodium 2-ethylhexanoate, potassium laurate, and sodium zolinate. Alkali metal salts of acids, alkali metal salts of aromatic carboxylic acids such as sodium benzoate and potassium benzoate, alkali metal salts of organic weak acids or their derivatives such as alkali metal phenolates and potassium phthalimide;
Furthermore, barium oxide, magnesium oxide, calcium oxide, lead monoxide, lead dioxide, dilead trioxide, trilead tetroxide, cadmium oxide, cupric oxide, barium hydroxide, magnesium hydroxide, calcium hydroxide, lead hydroxide. , cupric hydroxide, barium carbonate, magnesium carbonate, calcium carbonate,
Oxides, hydroxides, and carbonates of metals other than alkali metals, such as lead carbonate, are used.

The quaternary phosphonium compound of vulcanization component (d) is represented by the following general formula.

[Here, R1 to R4 are alkyl groups, aryl groups, aralkyl groups, alkenyl groups each having 1 to 20 carbon atoms, and their chlorine, bromine, fluorine, cyano group, -0R group, -CO-R group, one COOR group (however, R
is an alkyl, aryl, aralkyl or alkenyl group having 1 to 20 carbon atoms), and X is derived from an inorganic or organic acid in which the acidic hydrogen is bonded to a halogen or oxygen. For example, 0H, C1, Br, I, N03, HS04, N
aS04, H2P04, NaHP04, H2B03, C
6H50,R/COO,R/0S03,RIS03,R
7-C6. H4-0, B! 0P03H (where R' is an aliphatic group, an alkyl group or an alkaryl group having 1 to 20 carbon atoms, said aliphatic group can contain an ether, thioether, ester structure, for example an organic acid and/or an alkylphenoxypoly(ethyleneoxy)ethyl group which is a reaction product of alcohol and ethylene oxide, alkyloxypoly(ethyleneoxy)ethyl group, etc.).

] Specific examples of the quaternary phosphonium compound include tetraphenylphosphonium chloride, triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, triphenylmethoxymethylphosphonium chloride, triphenylmethylcarbonylmethylphosphonium chloride, triphenylethoxycarbonylmethyl Examples include phosphonium chloride, trioctylbenzylphosphonium chloride, trioctylmethylphosphonium bromide, trioctylethylphosphonium acetate, trioctylethylphosphonium dimethylphosphate, tetraoctylphosphonium chloride, cetyldimethylbenzylphosphonium chloride, and the like.

The vulcanizable blend rubber composition of the present invention comprises blend rubber 1
Based on 00 parts by weight, the weight ratio of the halogen-containing elastomer and the carboxyl group-containing elastomer is approximately 2:
It is used in a ratio of 98 to 98:2, preferably about 5:95 to 95:5.

One or more metal oxy compounds as vulcanization system components are used in an amount of about 0.5 to 20 parts by weight, preferably about 1 to 10 parts by weight, based on 100 parts by weight of the blended rubber.
Further, the quaternary phosphonium compound, which is another vulcanization system component, is used in an amount of about 0.1 to 10 parts by weight, preferably about 0.2 to 5 parts by weight, based on 100 parts by weight of the blend rubber. The ratio of each component of the vulcanization system to the blended rubber depends on the vulcanization rate, scorch resistance, mechanical properties of the vulcanizate,
It is selected as a preferable range based on the values of various properties such as heat aging resistance and compression set, and if the usage ratio is less than this, the vulcanization rate will decrease considerably, and the general physical properties of the vulcanizate will decrease. I was not able to find anything that was satisfactory in terms of
On the other hand, if the usage ratio is higher than this, the vulcanization rate will generally increase, but the scorch resistance (processing safety, storage stability)
The general properties of the vulcanizate are often impaired, and it is also inefficient, both of which are undesirable. In the vulcanization operation, these vulcanization system components are usually mixed with other additives such as reinforcing agents, fillers, anti-aging agents, stabilizers, plasticizers, lubricants, processing aids, etc. This is carried out by mixing with the elastomer by a commonly used mixing method such as mixing, banbury-mixing, kneader-mixing, or solution mixing, and then heating the mixture.

The vulcanization temperature is usually 120°C or higher, preferably 15°C.
A temperature of 0°C or higher is used. The halogen-containing elastomer and the carboxyl group-containing elastomer may be blended by the elastomers themselves, or may be mixed as a masterbatch in which each of the above-mentioned ingredients is blended with each elastomer. The vulcanizable blend rubber composition provided by the present invention exhibits vulcanization characteristics such as excellent scorch resistance and rapid curing, and the resulting vulcanizate also has high tensile strength,
It has good physical properties such as low compression set and high heat aging resistance, and has extremely favorable effects such as a good balance between cold resistance and oil resistance.

The obtained vulcanizate has excellent properties such as heat aging resistance, oil resistance, weather resistance, ozone resistance, and compression set, so these properties can be effectively utilized. It can be widely used in various applications such as various sealing materials (gaskets, packing, O-rings, oil seals, etc.), hoses, covering materials, general molded products, and various belts and rolls.

Next, the effects of the present invention will be explained with reference to Examples.

Synthesis of halogen-containing acrylic elastomer and carboxyl group-containing acrylic elastomer A comonomer mixture having the monomer composition (parts by weight) shown in Table 1 below is copolymerized,
Then, halogen-containing acrylic elastomers A and B and carboxyl group-containing acrylic elastomers C and D were synthesized, respectively.

The copolymerization reaction was carried out as follows.

First, 25 parts (by weight, the same below) in the comonomer mixture,
Charge 0.02 parts of dodecyl mercaptan (molecular weight regulator), 2 parts of polyoxyethylene dodecyl ether, 2 parts of sodium dodecyl sulfate, and 200 parts of water into a reaction vessel.
While maintaining the liquid temperature at 40°C, the atmosphere was sufficiently replaced with nitrogen. Then, when 0.1 part of ammonium persulfate and 0.1 part of sodium bisulfite are added, the polymerization reaction starts and the temperature starts to rise, and immediately the remaining 75 parts of the comonomer mixture is added in small amounts over about 45 minutes. The temperature of the reaction solution was maintained at 60°C. Thereafter, the mixture was further stirred for 1 hour to complete the polymerization reaction. The obtained copolymer latex was poured into 15% saline solution at about 85°C, and the coagulated copolymer was washed with water and dried to obtain each acrylic elastomer. Example 1 Regarding halogen-containing acrylic elastomers A and B and carboxyl group-containing acrylic elastomer C, the compounding ingredients of compounding prescriptions to M shown in the following Table 2 were kneaded using an 8-inch open roll to prepare a vulcanizable composition. .

Note that all numbers with brackets below are comparative examples. The various vulcanizable blend rubber compositions obtained were tested for their respective viscosity and scorch time (
The time required for the viscosity to reach the minimum value + 5, which is a guideline for processing safety and storage stability) is 1.
Measured at 21°C.

Further, the composition was press-vulcanized at 170°C for 10 minutes, and then vulcanized in an oven at 150°C for 10 hours, and various physical properties of the vulcanized product were measured in accordance with JISK-6301. The results obtained are shown in Table 3 below. Comparing the examples and comparative examples shown in these results: 1,,]/([V) In the vulcanization system of the present invention, by using the quaternary phosphonium compound, the vulcanization rate and the vulcanizate are improved. It can be seen that the physical properties are significantly improved, and therefore it is suitable for short-time vulcanization.

1., IIA: The vulcanization systems of the present invention using quaternary phosphonium compounds show superior scorch resistance and heat aging resistance over vulcanization systems using quaternary ammonium compounds. .

1,,1/(IV): The vulcanization system of the present invention using a quaternary phosphonium compound is superior to the vulcanization system using guanidines, especially in terms of vulcanization rate, heat aging resistance, and compression set. It shows that it is excellent.

/(V'111). It can be seen that in the vulcanization system of the present invention, all of the vulcanization characteristics, physical properties of the vulcanizate, heat aging resistance, and compression set are significantly improved by using the quaternary phosphonium compound.

, It can be seen that aging resistance, compression set and scorch resistance are all good.

From the above facts, when vulcanizing a blend rubber of a halogen-containing acrylic elastomer and a carboxyl group-containing acrylic elastomer, the vulcanization system according to the present invention has particularly significant improvements in scorch resistance, heat aging resistance, and compression set. It is clear that it can be improved.

In addition, even when press vulcanized for a short time of 10 minutes at 170°C, the vulcanized product exhibits excellent physical properties and compression set, so it has the advantage that post-vulcanization can be omitted. . Example 2 Polyepichlorohydrin (Hydrin 100, manufactured by Gutdoritsu) or epichlorohydrin-ethylene oxide copolymer (Hydrin 200, manufactured by Gutdrich) was used as the halogen-containing elastomer, and the acrylic elastomer C or D was used as the carboxyl group-containing elastomer. A vulcanizable composition was prepared by kneading various compounding agents using an 8-inch open roll according to the compounding recipe shown in .

The physical properties of the various vulcanizable blend rubber compositions obtained were measured in the same manner as in Example 1.

However, post-vulcanization was performed at 150° C. for 8 hours. The results obtained are shown in Table 5 below. Comparing the Examples and Comparative Examples shown in these results:/(XVI'). The vulcanization systems of the present invention using quaternary phosphonium compounds have been shown to be superior to vulcanization systems using quaternary ammonium compounds, particularly in terms of scorch resistance and heat aging resistance.

Xll/(XVIl), (XVlll): Compared with conventionally known vulcanization systems in which a blend rubber of an epichlorohydrin elastomer and a halogen-containing elastomer is vulcanized using polyamine salts or thioureas, the vulcanization system of the present invention It can be seen that the material is significantly superior in terms of scorch resistance, heat aging resistance, and compression set.

, XIl: ],
The vulcanization system of the present invention provides a vulcanizate with excellent scorch resistance, heat aging resistance and compression set.

In particular, when a blend rubber of an epichlorohydrin-ethylene oxide copolymer elastomer with excellent heat resistance and a carboxyl group-containing acrylic elastomer is vulcanized using the vulcanization system of the present invention, the heat resistance and compression set are It is also noteworthy that a material with excellent oil and cold resistance can be obtained. Example 3 As a halogen-containing elastomer, an ethylene-methyl acrylate vinyl chloroacetate (47:50:3% by weight) terpolymer elastomer (180% by weight according to ASTM-D-1238-52T) was synthesized by a known method.
1.3) or ethylene-methyl acrylate-n-butyl maleate (47:50: 3% by weight) terpolymer (melt index 1, 2) or the acrylic elastomer D described above, various compounding agents were added to 8% according to the compounding recipe shown in Table 6.
Vulcanizable compositions were prepared by kneading with inch open rolls.

The physical properties of the various vulcanizable blend rubber compositions obtained were measured in the same manner as in Example 1.

However, post-vulcanization was performed at 175° C. for 4 hours. The results obtained are shown in Table 7 below. From these results, even when using an ethylene-acrylate elastomer, the vulcanization system of the present invention has excellent scorch resistance, vulcanization properties, physical properties of vulcanized material,
It has been found that it provides a vulcanizate with excellent heat aging resistance and compression set, and also effectively advances co-vulcanization of blended rubber.

Claims (1)

[Scope of Claims] 1. Selected from the group consisting of (a) a halogen-containing elastomer, (b) a carboxyl group-containing elastomer, and (c) an alkali metal salt of an organic weak acid and an oxide, hydroxide or carbonate of a non-alkali metal. A vulcanizable blend rubber composition comprising at least one metal oxy compound and (d) a quaternary phosphonium compound. 2. The vulcanizable blend rubber composition according to claim 1, wherein the halogen-containing elastomer and the carboxyl group-containing elastomer are blended in a weight ratio of about 2/98 to 98/2. 3. The vulcanizable blend rubber composition according to claim 1, wherein the metal oxy compound is used in an amount of about 0.5 to 20 parts by weight based on 100 parts by weight of the blend rubber. 4. The vulcanizable blend rubber composition according to claim 1, wherein the quaternary phosphonium compound is used in an amount of about 0.1 to 10 parts by weight based on 100 parts by weight of the blend rubber.