JPS585347A - Terpolymer rubber composition - Google Patents

Abstract

PURPOSE:To provide the titled rubber compsn. having excellent resistance to sour gasoline and alcohol-contg. gasoline as well as excellent ordinary physical properties, cold resistance, compression set, etc., by blending a vinyl chloride resin with a specified terpolymer. CONSTITUTION:A terpolymer composed of 15-60mol% alpha,beta-unsaturated nitrile such as acrylonitrile, 10-75mol% conjugated diene such as butadiene-1,3 and 2- 55mol% 1-15C fluoroalkyl (meth)acrylate, is used. 97-40pts.wt. said terpolymer and 3-60pts.wt. vinyl chloride resin such as a vinyl chloride/vinyl acetate copolymer or polyvinyl chloride having a polymn. degree of 500-2,000 are mixed together by using a Banbury mixer, etc. to obtain a terpolymer rubber compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an α,β-unsaturated citri-conjugated dienta)fluoroalkyl acrylate terpolymer (hereinafter referred to as
(abbreviated as NBF) and vinyl chloride resin (hereinafter referred to as PV)
This article relates to a rubber composition comprising a rubber composition (abbreviated as C), which has excellent sour gasoline resistance and alcohol-containing curling resistance, and has excellent physical property performance in normal state physical properties, cold resistance, compression set, etc.

In recent years, automobile exhaust gas regulations have become stricter, and each automobile manufacturer is taking their own countermeasures.In addition, sour gasoline (gasoline that is oxidized at high temperatures and contains peroxide) while driving. A, N@rRu-amlas: Rubber and
Plastic News June 26 (197
8). ) has occurred and has become a new problem.

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

Conventionally, butadiene-acrylonitrile rubber (NBR) has been commonly used as a rubber material for fuel, but it is difficult for such materials to withstand the above-mentioned sour gasoline and alcohol-containing gasoline.

As a method to improve this, it is known to improve sour gasoline resistance by using a blend of butadiene-acrylonitrile rubber (NBR) and vinyl chloride (Japanese Patent Application Laid-Open No. 55-89338). Sour gasoline.

To improve the alcohol resistance of gasoline, normal physical properties,
Cold resistance, compression set, etc. are significantly sacrificed, and improvement of these drawbacks is desired. In addition, fluororubber has excellent resistance to sour gasoline and alcohol-containing gasoline. Tsuyoshi Sugiki Co., Ltd.) has been in the spotlight as a rubber material for fuel, but fluororubber cannot be vulcanized with sulfur, has poor normal physical properties, is difficult to handle, and is extremely expensive. It is not versatile as a fuel rubber material.

The present inventors have developed a product that has excellent resistance to sour gasoline and alcohol-containing gasoline, is sulfur vulcanizable, can be processed into products using conventional molding equipment and technology, and has excellent physical properties, cold resistance, and compression permanence. The terpolymer NBF has already been discovered as a new rubber material with an excellent balance of physical properties in terms of distortion, etc. (Il# Application No. 55-183847). As a result of further various investigations using the skeleton rubber material, the present inventors discovered that a composition formed by mixing NBF and PvC
More than being improved by mixing RKPVC and
As a fuel rubber material, it has excellent resistance to gasoline and alcohol-containing gasoline, and also has a good balance in normal physical properties and compression set. By mixing the
The present invention was achieved by discovering that the tensile strength and cold resistance are significantly improved.

That is, the present invention provides a terpolymer containing 15 to 60 mol% of α,β-unsaturated nitrile, 10 to 75 mol% of conjugated diene, 2 to 55 mol% of (meth)acrylic acid and fluoroalcohol (NBF). ) 97 to 40 parts by weight, vinyl chloride resin (
PVC) consisting of 3 to 60 parts by weight. Excellent resistance to sour gasoline and alcohol-containing gasoline, good normal physical properties, resistance and base.

The present invention relates to a rubber composition having well-balanced compression set.

Specific examples of the α,/-unsaturated nitrile of the terpolymer (NBF) used in the present invention include acrylonitrile, α
-Chloroacrylonitrile.

α-fluoroacrylic tetraunitrile methacrylonitrile,
Ethacrylonitrile, etc.

Among these, acrylonitrile is particularly preferred.

As the conjugated diene, butadiene-1,3,2-chlorobutadiene-1,3,2-fluorobutadiene-1,3
, j-methylbutadiene-1,3, etc. 1. Among these, butadiene-1,3 is particularly preferred.

In the fluoroalkyl (meth)acrylate, the alkyl group preferably has 1 to 2 carbon atoms, particularly preferably 1
-15 fluorine-containing alkyl groups, specific examples of which are:
1.1-dihydroperfluoroethyl (meth)acrylate, 1゜l-dihydroperfluoropropyl (meth)
acrylate), 1.1.5-trihydroperfluorohexyl (meth)acrylate), 1,1゜2.2-tetrahydroperfluoropropyl (meth)acrylate, 1
．． 1.7-) Lihydroperfluoroheptyl (meth)acrylate.

1.1-dihydroperfluorooctyl (meth)acrylate), 1.1-dihydroperfluoroodecyl (meth)
There are acrylates, among which 41 has 1.1-
Dihydroperfluoroethyl (meth)acrylate and 1,1-dihydroperfluoropropyl (meth)acrylate are preferred.

The composition ratio of each component of the terpolymer of the present invention is based on the total number of moles of the three components, and α,β-unsaturated nitrile is 15 to 60%.
mol% (preferably 20-55 mol%1, more preferably 25-50 mol%).

Conjugated diene 10 to 75 mol% (preferably 20 to 65 mol%, more preferably 35 to 65 mol%), (meth)
Fluoroalkyl acrylate 2 to 55 mol% (preferably 1 L<
is 4 to 45 mol%.

More preferably, it is 5 to 30 mol%).

The ratio of α,β-unsaturated nitrile in the terpolymer is 15
If it is less than mol %, gasoline resistance will be poor, and if it exceeds 60 mol %, it will become resinous and have poor processability. The ratio of conjugated diene is 1
If it is less than 0 mol %, the rubber elasticity will be poor and the normal physical properties of the polymer will be poor.

If the ratio of conjugated diene exceeds 75 mol%, resistance to gasoline and alcohol-containing gasoline will be poor. If the proportion of fluoroalkyl (meth)acrylate is less than 2 mol %, there is no effect on sour gasoline resistance and alcohol-containing gasoline resistance, and if it exceeds 55 mol %, cold resistance is poor.

The above terpolymer can be produced by conventional emulsion polymerization.

PvC used in the present invention is polyvinyl chloride and copolymers of vinyl chloride and vinyl acetate, ethylene, propylene, butadiene, styrene, etc. (usually the vinyl chloride content is 6
0 mol% or more, preferably 80 mol% or more). Also, there is no particular restriction, but preferably the degree of polymerization is 5.
00 to 2000 is used. The amount of PvC is 3 to 60 parts by weight based on 97 to 40 parts by weight of the terpolymer (NBF).
Parts by weight. If it is less than 3 parts by weight, no effect will be seen, and if it exceeds 60 parts by weight, the rubber properties will deteriorate.

The method of mixing these compositions is not particularly limited.

The following methods can be used.

H) A method of mixing a terpolymer (NBF) and PVC using a mixer such as a roll, a Banbury mixer, or an intermixer.

(b) After mixing the ternary copolymer (NBF) and PVC in a latex-like suspension state.

Coagulation treatment and co-precipitation method, or f → (a)
The ternary copolymer rubber composition obtained by the present invention may be treated with (9) and (9) in combination with conventional compounding chemicals, such as reinforcing agents, fillers, etc., as necessary. A vulcanized product can be obtained in a container by a conventional vulcanization method.

The vulcanizing agent is arbitrarily selected from common vulcanizing systems such as sulfur-based, thiuram-based, and organic peroxides.

By being vulcanized, the terpolymer rubber footwear of the present invention has excellent sour gasoline resistance, alcohol-containing gasoline resistance, gasoline resistance, cold resistance, tensile strength, and elongation, and is useful for practical use. Since it provides a vulcanizate with compression set, it is preferably used as a material for various fuel rubber parts such as gaskets*, zero-lift puffers, and carburetor floats.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention will be described without exceeding its gist.

It is not intended to be limited to these examples.

[Examples 1 to 6, Comparative Examples 1 to 6] Examples 1 to 6 and Comparative Example 2 ONBF shown in the upper row of Table 2
/PVC blend composition, terpolymer (NBF) of Comparative Example 1°3.4, Comparative Example 5ONBR, Comparative Example 6ONBR
/PVC blend compositions were blended using a Banbury mixer according to the blending recipe shown in Table 1. The resulting compound was press-vulcanized at 150C for 30 minutes to obtain a vulcanized product.

The physical properties of the vulcanizate were measured according to the following method.

The results are shown in the lower part of Table 2.

l) Tensile test JIS K 6301-32) Hardness test JIS K6301-5 JIS Al13) Gasoline resistance test JIS K6301-12 Test oil C (
The volume change after immersion in 40CX (isooctane/toluene-50150 mixture) for 48 hours was measured.

4) Alcohol-resistant gasoline test JIS K2SO
3-12 Measurement was carried out in the same manner as in the gasoline resistance test except that a mixture of test oil C/methyl alcohol = 80/20 (volume ratio) was used as the immersion liquid.

5) Sour resistance/gasoline resistance test Dissolve t-butyl hydroperoxide in test oil C at a concentration of 50 x 4 and immerse the sample in the test solution for 24 hours at 80C for 6 cycles. After that, it was dried under reduced pressure at 10 Gt:' for 15 hours. The cracking elongation and breaking elongation of this material were measured according to JIS K6301-3.

6) Cold resistance (impact embrittlement test) JISK6301-147
) Compression set JISK6301-101201:'X
Adjusted at 70 hours.

Table 1 Compounding recipe Polymer 100 Zinc white 5 Stearin 1 MT carbon black Variable *b) *1) Plasticity 1i1jDOP*e) 20 Vulcanization accelerator TT*d) 1.8 CZ") 2.0 Sulfur 0.5* a)
Medium Thermal Furnace Black Book b) K so that the hardness of the vulcanizate is in the range of 70±5.

C) Dioctyl 7-talate D) Tetramethylthiuram disulfide* N-cyclohexyl-2-benzothiazole sulfenamide As shown in Table 2, the composition of the NBF/PVC blend of the present invention The item has excellent gasoline resistance.

It has alcohol-containing gasoline resistance and sour gun phosphor resistance, and when blended with ordinary NBRKPVC (Comparative Example 5.6), the tensile strength and cold resistance are significantly improved compared to K, and it is a practical compression permanent material. Coupled with strain, we can provide excellent nine fuel rubber materials.

Claims (4)

[Claims] (1) α,/-unsaturated nitrile 15 to 60 mol%,
Ternary copolymer 97 consisting of 10 to 75 mol% of conjugated diene and 2 to 55 mol% of fluoroalkyl (meth)acrylate
A terpolymer rubber composition consisting of ~40 parts by weight and 3 to 60 parts by weight of a vinyl chloride resin. (2) The terpolymer rubber composition according to claim (1), wherein the α,/-unsaturated hydryl is acrylonitrile. (3) The terpolymer rubber composition according to claim (1), wherein the conjugated diene is butadiene-1,3. (4) The terpolymer rubber composition according to claim (1), wherein the fluoroalkyl group of the fluoroalkyl (meth)acrylate has 1 to 15 carbon atoms.