JPS60203659A - Multicomponent copolymer rubber composition - Google Patents

Abstract

PURPOSE:To obtain a gasoline-resistant rubber composition especially with high sour gasoline and sour gasohol resistance, by blending a multicomponent copolymer rubber consisting essentially of (meth)acrylic acid cyano-substituted alkyl ester and acrylic alkyl ester and vinyl chloride resin. CONSTITUTION:The objective composition can be obtained by blending a multicomponent copolymer rubber prepared from (A) 10-69.5wt% of a (meth)acrylic acid cyano-substituted alkyl ester (pref. 2-cyanoethyl acrylate), (B) 30-89.5wt% of acrylic alkyl ester (pref. ethyl acrylate) (C) 0.5-10wt% of a compound selected from diene compounds (pref. alkylidene norbornenes), (meth)acrylic acid dihydrodicyclopentadienyl group-contg. esters, epoxy group-contg. ethylenic unsaturated compounds and active halogen-contg. ethylenic unsaturated compounds, and (D) 0-10wt% of another ethylenic unsaturated compound copolymerizable with the components (A), (B) and (C) and >=5pts.wt. based on 100pts.wt. of the final blend, of vinyl chloride resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gasoline-resistant rubber composition having excellent sour gasoline resistance and sour gasohol resistance, as well as excellent ozone resistance and heat resistance.

In recent years, the atmosphere in which gasoline-resistant rubber is used in automobiles has tended to become increasingly hot as a result of exhaust gas control measures and engine improvements aimed at improving performance. Contains rubber with excellent gasoline (oil) resistance. Furthermore, gasoline is oxidized and becomes sour gasoline (gasoline is oxidized at high temperature and contains peroxide.
rsasian: Rubber andPlast
ics News Jun, e 2B (197B)), which causes the problem of deterioration of the rubber.

Furthermore, due to tight global crude oil supply and demand conditions, attempts have been made to mix alcohol with gasoline.

This alcohol-mixed gasoline (gasohol) also has the problem of being oxidized like normal gasoline, producing sour gasohol.

Conventionally, butadiene-acrylonitrile rubber has been widely used as a gasoline-resistant rubber for hoses, gaskets, O-rings, punctures, oil seals, and the like. However, butadiene-acryliconi-1-lyl rubber has poor ozone resistance, and is also insufficient in heat resistance and sour gasoline resistance. Parts are difficult to obtain.

As a method to improve this, it is known that sour gasoline resistance and ozone resistance are improved by using a blend of butadiene-acrylonitrile rubber and polyvinyl chloride (Japanese Patent Laid-Open No. 89338/1989). However, the heat resistance is not improved, and the gasohol resistance is also not sufficient.

Therefore, the inventors of the present invention have conducted extensive studies in order to obtain a rubber material that has excellent sour gasoline resistance and sour gasohol resistance, as well as excellent ozone resistance and heat resistance.
A rubber composition consisting of a mixture of a new multi-component copolymer rubber containing a cyano-substituted alkyl acrylic ester and an alkyl acrylic ester as essential components, and a vinyl chloride resin has excellent ozone resistance, heat resistance, We have discovered that it not only has excellent sour gasoline properties, but also has excellent sour gasohol resistance, which is a new required performance, and also has a good balance between tensile strength, elongation, gasoline resistance, and cold resistance, and has developed the present invention. Reached.

(A) 10 to 69.5% by weight of (meth)acrylic acid cyano-substituted alkyl ester.

(B) Acrylic acid alkyl ester 30-B9.5iQ
Jfi%.

(C) At least one compound selected from diene compounds, dihydrodicyclopentadienyl group-containing esters of (meth)acrylic acid, epoxy group-containing ethylenically unsaturated compounds, and active halogen-containing ethylenically unsaturated compounds 0.5 ~lO wt%.

(D) 0 to 10% of other ethylenically unsaturated compounds copolymerizable with CA), (B), and (C).

The present invention provides a multicomponent J1:fJ composite rubber composition containing at least 5 parts by weight of a vinyl chloride resin in 100 parts by weight of a mixture of a multicomponent copolymer rubber and a vinyl chloride resin having a polymerization composition of

The (meth)acrylic acid cyano-substituted alkyl ester of component (A) is represented by the following general formula (i) (where R1 is hydrogen or a methyl group, and R7 is an alkylene group), and is 7R2. --CN has 2 or more carbon atoms
12 cyanoalkyl groups. For example, cyanomethyl (meth)acrylate, 1-cyanoethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate,
1-cyanopropyl (meth)acrylate, 2-cyanopropyl (meth)acrylate, 3-cyanopropyl (
meth)acrylate, 4-cyanobutyl(meth)acrylate, 6-cyanohexyl(meth)acrylate, 2
-ethyl-6-cyanohexyl (meth)acrylate,
Examples include 8-cyanooctyl (meth)acrylate, particularly preferably 2-cyanoethyl acrylate, 3
-cyanopropyl acrylate, 4-cyanobutyl acrylate.

The acrylic acid alkyl ester of the component (B) has the following general formula (11) (where R3 represents an alkyl group having 1 to 18 carbon atoms).

For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n
-butyl acrylate, inbutyl acrylate, n-
Pentyl acrylate, isoamyl acrylate, n-
Examples include hexyl acrylate, 2-methylpentyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate-1, n-decyl acrylate, n-dodecyl acrylate, n-octadecyl acrylate, and particularly preferably ethyl acrylate, n- -Propyl acrylate, n-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, 2-
They are ethylhexyl acrylate and n-octyl acrylate.

Among the compounds of component (C) above, as a diene compound,
Examples include non-conjugated dienes such as alkylidenenorbornene, alkenylnorbornene, dicyclopentadiene, methylcyclopentadiene and its dimer, and conjugated dienes such as butadiene and isoprene; Preferably, it is a non-conjugated diene selected from the group consisting of methylcyclopentadiene and its dimer.

Among the compounds of component (C) above, dihydrodicyclopentadienyl group-containing esters of (meth)acrylic acid include dihydrodicyclopentadienyl (meth)acrylate, dihydrodicyclopencdienyloxyethyl (
Meta)acrylates are mentioned.

Furthermore, among the compounds of component (C), examples of the epoxy group-containing ethylenically unsaturated compound include allyl glycidyl ether, glycidyl methacrylate, and glycidyl acrylate.

Furthermore, among the compounds of component (C) above, specific examples of active halogen-containing tyrenic unsaturated compounds include vinylbenzyl chloride, vinylbenzyl bromide, 2-
Chlorethyl vinyl ether, vinyl chloroacetate, vinyl chlorpropionone-1, allyl chloroacetate, allyl chloropropionate, 2-chloroethyl acrylate, 2-chloroethyl methacrylate, chlormethylvinyl ketone, 2-chloroacetoxymethyl-
Examples include 5-norbonene, among which vinyl chloroacetate, allyl chloroacetate, 2-chloroethyl vinyl ether, vinylbenzyl chloride)'
, 210 ethyl methacrylate, and 2-chloroethyl acrylate are preferred.

As the above component (D), various compounds can be used as necessary, examples include acrylic acid, methacrylic acid, crotonic acid, 2-pentenoic acid, maleic acid, fumaric acid, itaconic acid, etc. Carboxyl group-containing compounds, methacrylates such as methyl methacrylate and octyl methacrylate, alkoxyalkyl acrylates such as methoxyethyl acrylate and butoxyethyl acrylate, alkyl vinyl ketones such as methyl vinyl ketone, vinyl and allyl ethers such as vinyl ethyl ether and allyl methyl ether nato. , vinyl aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, and vinyltoluene; vinyl nitriles such as acrylonitrile and methacrylonitrile; vinylamides such as acrylamide, methacrylamide, and N-methylolacrylamide; and vinyl chloride, vinylidene chloride, and alkyl fumers. Examples include rates.

The composition ratio of components (A>, (B), (C) and (D) in the copolymer of the present invention is 10 to 69.5 for component (A).
% by weight, component (B) 30-89.5% by weight and (C)
The content of component (D) is 0.5 to 10% by weight, and the content of component (D) is 0 to 10% by weight.

If the component (A) is less than 10% by weight, the gasoline resistance, sour gasoline resistance, and sour gasoline resistance of the copolymer will be poor, and if it exceeds 69.5% by weight, the tensile strength will be poor.
It is unfavorable because its normal physical properties such as elongation are poor.

If the amount of component (B) is less than 30% by weight, the normal physical properties of the multi-component copolymer rubber will be poor, and if it exceeds 89.5% by weight, the gasoline resistance, sour gasoline resistance and gasohol resistance will deteriorate.

If the above component (C) is less than 0.5% by weight, it will take a long time to crosslink the multi-component copolymer rubber, and if it exceeds 10% by weight, the rubber will become hard and the elongation of the crosslinked rubber will decrease, which is undesirable. .

The above multi-component copolymer rubber can be produced by conventional emulsion polymerization.

The vinyl chloride resin used in the present invention is polyvinyl chloride or a copolymer of vinyl chloride with vinyl acetate, ethylene, propylene, butadiene, styrene, etc. (usually the vinyl chloride content is 60 mol% or more, preferably 80 mol%). above) are included. Although there is no limit to the number of polymers, those having a degree of polymerization of 500 to 2,000 are preferably used.

The amount of vinyl chloride resin used is at least 5 parts by weight of the mixture of multi-component copolymer rubber and vinyl chloride resin.
Parts by weight. If the amount is less than 5 parts by weight, no effect will be seen, and the amount is preferably 10 parts by weight or more.

As the amount of vinyl chloride resin in the mixture increases, it does not lose its rubber elasticity and its resin-like properties become stronger.
The upper limit of usage will be determined automatically.

Preferably it is 60 parts by weight or less.

The proportions of the multicomponent copolymer rubber and vinyl chloride resin in the composition of the present invention can be appropriately determined within the above range depending on the purpose of use and required performance.

The method of mixing the composition of the present invention is not particularly limited, but for example, the following method can be used.

(a) A method of mixing the multi-component copolymer rubber and PvC using a mixer such as a roll, a Banbury mixer, or an intermixer; (b) A method of mixing the multi-component copolymer rubber and PvC in latex or suspension form, respectively. Examples include a method of co-precipitating by coagulating after mixing, or a method of using (c), (a) and (b) together.

The multi-component copolymer rubber composition of the present invention can be blended with conventional compounding chemicals such as reinforcing agents, fillers, plasticizers, softeners, crosslinking agents, stabilizers, etc., as necessary. A crosslinked product can be easily obtained by the crosslinking method.

As the crosslinking agent, a suitable compound can be selected depending on the type of functional group used for crosslinking introduced into the copolymer. For example, when a carbon-carbon double bond is introduced by copolymerizing a diene compound or a dihydrodicyclopentadienyl group-containing ester of (meth)acrylic acid, so-called vulcanizing agents such as sulfur and thiuram are used. Crosslinking agents used in general diene rubbers (styrene-butadiene rubber, isoprene rubber, butadiene-acrylonitrile rubber, etc.) such as organic peroxides and organic peroxides can be suitably used.

When an epoxy group is introduced into the copolymer by copolymerizing an epoxy group-containing monomer, polyamine carbamates, ammonium organic carboxylates, dithiocarbamates, alkali metal salts of organic carboxylates, and sulfur compounds are combined. You can use things like Also,
When an active halogen group is introduced by copolymerizing an ethylenically unsaturated compound containing an active halogen, suitable materials include polyamine carbamates, ammonium organic carboxylates, and combinations of alkali metal salts of organic carboxylic acids and sulfur compounds. It can be used for.

The multicomponent copolymer rubber composition of the present invention has excellent gasoline resistance, sour gasoline resistance, ozone resistance, and heat resistance, and also has excellent sour gasohol resistance, which is a new required performance.
In addition, it has good tensile strength, elongation, and cold resistance, so it is used for various hoses that come into contact with fuel oil, hydraulic oil, lubricating oil, etc., including automobile fuel hoses, diaphragms, gaskets, etc. - Used for various sealing materials such as rings and oil seals, as well as for various rolls, power transmission belts, conveyor belts, etc. that require oil resistance and solvent resistance, such as for steel manufacturing, spinning, printing, paper manufacturing, dyeing, etc. be able to.

In particular, it can be suitably used as a rubber for automobile fuel system bosses by taking advantage of its excellent sour gasoline resistance and sour gasohol resistance.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples unless it exceeds the gist thereof.

Examples 1 to 5, Comparative Examples 1 to 3 Multi-dimensional Kyori combination Go4 of sample numbers 1 to 7 shown in the upper row of Table 2
Vinyl chloride resin (hereinafter abbreviated as Pvc) blend composition and sample number 8 butadiene-acrylonitrile rubber (
Each sample of the (hereinafter abbreviated as NBR)/PVC blend composition was blended in a Banbury mixer according to the blending recipe shown in Table 1. The obtained formulation was precured according to the conditions shown in the lower row of Table 1.

The properties of the obtained crosslinked rubber were measured according to JIS K 6301.

Mata, sour gasoline resistance, sour gasohol resistance,
Evaluation was made using the following method.

[Sour gasoline resistance]

The test piece was immersed for 72 hours at 40'C in a solution in which 2.5 g of lauroyl peroxide was dissolved in 97.5 g of Fuel C (mixed solvent of isooctane:toluene-1:1'' (volume ratio)). A test piece was taken out after each cycle.After drying under reduced pressure at 100°C for 15 hours, the test piece was bent at 180°C and the state of crack formation was observed.

[Sour gasohol resistance]

Instead of Fuel C, use a mixed solvent of Fuel C and methanol (by volume, FueIC:methanol-80
The results of 6 evaluations, which were evaluated in the same manner as the evaluation method for sour gasoline resistance except that 20) was used, are shown in the lower part of Table 2.

From the results in Table 2, the multi-component copolymer rubber composition of the present invention has excellent sour gasoline resistance, sour gasohol resistance, ozone resistance, and heat resistance, and also has excellent tensile strength, elongation, and gasoline resistance. It can be seen that the rubber composition has an excellent balance of cold resistance.

Examples 6 to 10, Comparative Example 4 2-cyanoethyl acrylate/ethyl acrylate/
n-butyl acrylate/ethylidene norbornene-3
By changing the mixing ratio of PVC to a multi-component copolymer rubber having a copolymerization composition of 5/31/31/3 (weight ratio),
Compositions with different blend compositions were prepared, blended in a Banbury mixer according to the formulation shown in the upper row of Table 3, and precured at 170°C for 20 minutes.

The properties of the obtained crosslinked rubber were measured in the same manner as in Example 1,
The results are shown in the lower part of Table 3.

From the results in Table 3, the multi-component copolymer rubber composition of the present invention has excellent sour gasoline resistance and sour gasohol resistance,
It can be seen that the rubber composition has good tensile strength and elongation, and also has compression set characteristics within a practical range.

Continuing from page 1 ■Int, C1,' Identification code Internal reference number I C0
8F 22G/18 8319-4J220/34 8
319-4J

Claims (1)

[Scope of Claims] (11(A) 10 to 69.5% by weight of (meth)acrylic acid cyano-substituted alkyl ester. (B) 30 to 89.5% by weight of acrylic acid alkyl ester. (C) Diene compound, ( (D ) Other ethylenically unsaturated compounds copolymerizable with (A), (B), and (C) O to 10% by weight. 100% by weight of a mixture of a multicomponent copolymer rubber and a vinyl chloride resin having a polymerization composition of A multicomponent copolymer rubber composition containing at least 5 parts by weight of a vinyl chloride resin. (2) The (meth)acrylic acid cyano-substituted alkyl ester of (A) is 2-cyanoethyl acrylate, 3-
The multicomponent copolymer rubber composition according to claim 1, which is a compound selected from the group consisting of cyanopropyl acrylate and 4-cyanobutyl acrylate. (3) The acrylic acid alkyl ester of (B) above is
Ethyl acrylate, n-propyl acrylate, n-
Butyl acrylate, n-pentyl acrylate, n-
The multicomponent copolymer rubber composition according to claim 1, which is a compound selected from the group consisting of hexyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. (4) Claim 1, wherein the diene compound (C) is a compound selected from the group consisting of alkylidenenorbornene, alkenylnorbornene, dicyclopentadiene, methylcyclopentadiene, and dimers thereof.
The multi-component copolymer rubber composition described in 1. '5) The multicomponent copolymer according to claim 1, wherein the epoxy group-containing ethylenically unsaturated compound (C) is a compound selected from the group consisting of allyl glycidyl ether, glycidyl methacrylate, and glycidyl acrylate. Combined rubber composition. (6) The active halogen-containing ethylenically unsaturated compound of (C) above is vinylchloroacetate-1., allylchloroacetate, 2-chloroethyl vinyl ether, vinylbenzyl chloride, 2-chloroethyl methacrylate,
The multicomponent copolymer rubber composition according to claim 1, which is a compound selected from the group consisting of 2-chloroethyl acrylate.