JPH0647635B2 - Oil resistant, weather resistant polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an oil-resistant and weather-resistant polymer composition having excellent mechanical properties, and further having an excellent balance between oil resistance and cold resistance. More specifically, it relates to a polymer composition containing an unsaturated nitrile-conjugated diene-based copolymer, an ethylene-α-olefin-based copolymer and a modified olefin-based copolymer as essential components.

[Conventional technology]

The technique of bringing out the performance which cannot be obtained by a single elastomer by blending two or more elastomers has been practiced for a long time. In addition to imparting new performance, blending techniques are also used for the purpose of improving processability and reducing raw material costs. As a typical example, a blend composition of styrene-butadiene rubber (hereinafter abbreviated as SBR) and polybutadiene rubber (hereinafter abbreviated as BR) as a material for a tire tread, and SBR and EPDM (ethylene- Propylene-
Examples include blend compositions of non-conjugated diene rubber). As seen in the latter example, a blend of EPDM and another diene-based elastomer is intended to improve weather resistance, particularly ozone resistance, but the mechanical properties of the blend are to be blended. It was generally the case that the The partner to be blended with EPDM is acrylonitrile-butadiene rubber (hereinafter NBR
In the case of an elastomer having a high polarity such as (abbreviated), the tendency is particularly remarkable, and the blended rubber cannot be put to practical use because of its poor mechanical properties.

Recently, a method of blending halogenated EPDM with NBR (JP 59-71345A, JP 60-118723) A method of blending halogenated EPDM and modified NBR (JP 59-226038), EPDM and NBR As a third component, a crystalline α-olefin polymer (JP-A-57-190031),
Alternatively, a method of blending an EPDM graft polymer (Japanese Patent Laid-Open No. 54-106554) has been proposed.

However, these solutions are not yet sufficient as the needs of recent oil resistant and weather resistant rubbers having an excellent balance of oil resistance and cold resistance.

[Problems to be solved by the invention]

In recent years, due to its high performance, the demand for rubber materials has become more stringent, especially for automotive applications, and especially unsaturated nitrile-conjugated diene copolymer rubber / ethylene-α-as oil-resistant and weather-resistant materials. For olefin-based copolymer rubber blends, there is a demand for materials having better mechanical strength.

[Means for solving problems]

In view of these points, the present inventors have earnestly studied, and as a result, unsaturated nitrile-conjugated diene-based copolymer, ethylene-α-
It was found that a rubber composition having good mechanical strength and having an excellent balance of oil resistance, cold resistance, and weather resistance can be produced by blending a modified olefin copolymer with an olefin copolymer. The present invention has been reached.

That is, the present invention is an unsaturated nitrile-conjugated diene copolymer
(A) and an ethylene-α-olefin copolymer (B) and an ethylene-α-olefin copolymer an amino group, a hydroxyl group, an epoxy group, a carboxyl group, or a monomer having an acid anhydride group The present invention relates to a polymer composition containing 0.01 to 20 parts by weight of a modified olefin copolymer (C) added per 100 parts by weight of the polymer as an essential component.

The α, β-unsaturated nitrile-conjugated diene-based copolymer (A) used in the present invention is an α, β-unsaturated nitrile such as acrylonitrile or methacrylonitrile and 1,3-butadiene, isoprene, 1,3 -Copolymerized with at least one conjugated diene such as pentadiene, or part of the conjugated diene such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid, etc., or methyl ester or butyl ester of these unsaturated carboxylic acids. , A copolymer substituted with 2-ethylhexyl ester or the like. Specifically, acrylonitrile-butadiene copolymer, acrylonitrile-isoprene copolymer, acrylonitrile-butadiene-isoprene copolymer, acrylonitrile-butadiene-acrylic acid copolymer, acrylonitrile-butadiene-methyl acrylate copolymer and the like are included. .

The amount of bound nitrile in the α, β-unsaturated nitrile-conjugated diene-based copolymer is 10 to 60% by weight, preferably 1
It is 5 to 50% by weight. If it is less than 15% by weight, the oil resistance is poor, and if it exceeds 50% by weight, the properties as rubber are impaired.

Examples of the ethylene-α-olefin copolymer (B) used in the present invention include an ethylene-α-olefin copolymer and / or an ethylene-α-olefin-diene terpolymer. Here, the α-olefin is C _{3 to} C ₈
Α-olefins, namely propylene, butene-1,
Examples include hexene-1 and octene-1, but propylene is preferred.

Examples of the diene-based monomer include open-chain non-conjugated diolefins such as 1,4-hexadiene, cyclic dienes such as dicyclopentadiene, and alkylidene norbornenes such as ethylidene norbornene.

It can be obtained by using the above-mentioned ethylene-α-olefin-based copolymer as the modified olefin-based copolymer (C) and adding a reactive monomer having various functional groups thereto. As the reactive monomer added to the ethylene-α-olefin copolymer, an amino group, a hydroxyl group,
Examples thereof include a monomer containing an epoxy group, an erboxyl group or an acid anhydride group.

Specific examples of the amino group-containing monomer include diethylaminoethyl (meth) acrylate, dimethylaminomethyl (meth) acrylate, and vinylpyridine.

Examples of the monomer containing a hydroxyl group include hydroxypropyl (meth) acrylate and hydroxyethyl (meth) acrylate.

Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, allyl glycidyl ether, and vinyl glycidyl ether.

As the monomer containing a carboxyl group or an acid anhydride group, acrylic acid, methacrylic acid, ethacrylic acid,
Maleic acid, maleic anhydride, fumaric acid, itaconic acid,
Examples thereof include α, β-unsaturated carboxylic acid such as itaconic anhydride, hymic acid, and hymic acid anhydride, or acid anhydrides thereof.

Of these, a monomer compound containing a carboxyl group or an acid anhydride group is preferable, and maleic anhydride is particularly preferable, from the viewpoint of easy addition reaction operation to the ethylene-α-olefin copolymer.

The amount of these reactive monomers added to the ethylene-α-olefin copolymer is 0.01 to 20 parts by weight, preferably 0.2 to 5 parts by weight, per 100 parts by weight of the polymer. If it is less than 0.01 part by weight, the effect of improving the mechanical strength and oil resistance, which is the effect of the present invention, is poor, and if it exceeds 20 parts by weight, the properties as rubber are impaired due to gelation.

Regarding the addition reaction of a monomer containing various functional groups to an ethylene-α-olefin-based copolymer, see JP-B-39-6384.
The method described in can be used. That is, the ethylene-α-olefin copolymer and various monomers can be reacted by mixing and heating them in a solid state. The heating method may be either a method using a closed kneader or a method in which heating reaction is continuously performed using an extruder or the like. In this case, 1 part peroxide may be used to accelerate the reaction.

Regarding the compounding ratio of the component (A) and the component (B) + (C) in the present invention, from the viewpoint of improving oil resistance and weather resistance, the component (A) / (B)
The blending weight ratio of the + (C) component is in the range of 90/10 to 10/90, more preferably 80/20 to 20/80, and the blending ratio of the (B) component and the (C) component is mechanical. The blending weight ratio of the (B) component / (C) component is 95/5 to 5 from the viewpoint of improving the mechanical strength and oil resistance.
The range is / 95, more preferably 90/10 to 10/90.

In addition to the essential components (A), (B) and (C) as the composition of the present invention, if necessary, various compounding agents commonly used in the rubber industry, such as a reinforcing agent and / or a filler. , A plasticizer, a processing aid, an antiaging agent, a vulcanization system, and kneaded with a mixer such as a roll or Banbury,
And a vulcanized product thereof.

The present invention will be described below with reference to examples, but the present invention is not limited thereto.

The physical properties of the composition of the present invention are mainly JIS K-630.
1, the mechanical properties are tensile test and flex test,
For the oil resistance, the JIS No. 3 oil and fuel oil B were used for the immersion test, for the weather resistance, the ozone deterioration test was used, and for the cold resistance, the Gehman torsion test was used as the evaluation standard.

〔Example〕

The modified olefin copolymers (a to g) were prepared as follows.

Ethylene-propylene copolymer (manufactured by Nippon Synthetic Rubber Co., Ltd.)
JSREP02P Mooney viscosity ML _{1 + 4} (100 ℃) = 24) 0.01 to 80 parts by weight of maleic anhydride and 2,5-
A twin-screw extruder (TEM-50A manufactured by Toshiba Machine Co., Ltd.), in which 0.2 to 1.0 part by weight of di-methyl-2,5-di- (t-butylperoxy) hexane was preset to 180 to 250 ° C, D
= 53 mmφ, L / D = 30.6) and melt-mixed with a residence time of 2 to 7 minutes to obtain modified EP (a-1 to 5).

In the same manner as above, modified EP (b) (c) (d) (e) was obtained by using acrylic acid, diethylaminoethyl acrylate, hydroxyethyl methacrylate, and glycidicumamethacrylate in place of maleic anhydride. In addition, modified EP (f)
Is an ethylene-propylene copolymer (JSREP911P Mooney viscosity M _{1 + 4} (100 ° C.) = 15 manufactured by Nippon Synthetic Rubber Co., Ltd.)
The modified EP (g) is an ethylene-propylene-diene copolymer (JSREP35 Mooney viscosity ML _{1 + 4} (100) manufactured by Nippon Synthetic Rubber Co., Ltd.).
C.) = 83) and modified with maleic anhydride. Table 1 shows the modified olefin-based copolymers prepared by the above formulation.

Using the modified EP obtained according to the above method, kneading with a Banbury mixer according to the formulation shown in the following table, 16
Press vulcanization was performed at 0 ° C. for 20 minutes.

Table 2 shows the physical property evaluation results of the obtained vulcanizates.

As is clear from the comparison between Table 2 and Examples 1 to 7 and Comparative Example 1 and Examples 12 and 13 and Comparative Examples 5 and 6, the composition of the present invention not only has good mechanical strength but also oil resistance. It can be seen that it is an oil-resistant and weather-resistant polymer composition having an excellent balance of resistance and cold resistance.

From the comparison between Examples 1, 8, 9 and 14 and Comparative Examples 1, 2 and 5, the composition ratio (weight ratio) of the component (B) and the component (C) of the composition of the present invention was 95 / 5- It can be seen that within the range of 5/95, it has excellent mechanical strength and oil resistance.

From the comparison between Examples 1, 10 and 11 and Comparative Examples 3 and 4, mechanical strength was found when the amount of the reactive monomer as the component (C) of the present invention added was less than 0.01 parts by weight per 100 parts by weight of the polymer. It is also found that the oil resistance is poor, and when it exceeds 20 parts by weight, the mechanical strength is poor.

[Effect of the Invention] The polymer composition according to the present invention is an oil-resistant and weather-resistant polymer composition which is excellent in mechanical properties and further has a good balance between oil resistance and cold resistance. Specific applications of the polymer composition include various hoses (fuel hose, oil hose, freon hose, gas hose, brake hose, etc.),
Examples thereof include cover materials for hoses, packings, oil seal rings, gaskets, belts, linings, industrial parts such as dust boots, parts for automobiles, aircraft and the like.

Claims (2)

[Claims] 1. An (A) α, β-unsaturated nitrile-conjugated diene-based copolymer (B) an ethylene-α-olefin-based copolymer (C) an ethylene-α-olefin-based copolymer in 100 parts by weight. On the other hand, a modified olefin copolymer containing 0.01 to 20 parts by weight of a monomer having an amino group, a hydroxyl group, an epoxy group, a carboxyl group or an acid anhydride group is added as an essential component, and the (A) component And the mixing ratio of the (B) + (C) components is 90:10 to 10:90 by weight, and the mixing ratio of the (B) component and (C) component is 95: 5 to 5:95. An oil-resistant and weather-resistant polymer composition characterized by: 2. The polymer composition according to claim 1, wherein the modified olefin copolymer (C) has maleic anhydride added thereto.