JPH04180932A - Vulcanizable rubber composition - Google Patents

Abstract

PURPOSE:To obtain a vulcanizable rubber composition which does not undergo phase separation before being vulcanized and excels in the mechanical properties and other properties of a vulcanizate by mixing a specified fluororubber polymer with a specified organosiloxane and/or an organosiloxane or its partial hydrolyzate and a vulcanizing agent. CONSTITUTION:This composition comprises 100 pts.wt. fluororubber polymer (A) comprising at least 10mol% repeating vinylidene fluoride units, 0.1-300 pts.wt. organosiloxane of formula I (wherein R<1> is a bivalent hydrocarbon group; R<2> is a substituted or unsubstituted monovalent hydrocarbon group; (n) is 0 or a positive integer of 4 or smaller; 0<a<=3; 0<=b<3; and 0<a+b<=3) and/or organosilane of formula II (wherein R<1>, R<2> and (n) are as defined above; X is hydroxyl and/or a hydrolyzable groups selected from halogen and 1-10 C alkoxy ; (c) is 1, 2 or 3; (d) is 0, 1 or 2; (e) is 1, 2 or 3; and (c + d+ e)= 4) or its partial hydrolyzate (B) and a vulcanizing agent (C) in an amount sufficient to vulcanize component A.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vulcanizable rubber composition.

[Prior Art] Conventionally, fluororubber is a rubber material that has the best heat resistance, oil resistance, and weather resistance, and has been suitably used for automobile rubber parts such as oil seals, O-rings, and fuel hoses. However, it has the disadvantage of poor low-temperature flexibility.

As a means to solve this problem, various studies have been made on compositions containing silicone rubber that has excellent low-temperature properties.

However, in reality, fluororubber and silicone rubber have poor affinity, and it is difficult to knead them to obtain a uniform mixture, and the processability of the mixture thus obtained is also extremely poor.

In addition, in blends of components that inherently have poor co-vulcanization properties, the physical properties obtained by vulcanization are extremely insufficient, even though each rubber has excellent properties, and it is difficult to bring out the characteristics of both components. The current situation is that this has not been achieved.

[Problems to be Solved by the Invention] The present invention was made against the background of the technical problems of the prior art described above, and by chemically bonding fluororubber and silicone polymer, it is possible to improve the microdispersibility of both. To provide a vulcanizable rubber composition that significantly improves the properties of the unvulcanized rubber composition, does not cause phase separation, and has excellent roll workability, mechanical strength, heat resistance, cold resistance, oil resistance, and weather resistance. The purpose is to

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems.
100 parts by weight of fluororubber polymer containing mol% or more (B) General formula (where R1 is a divalent hydrocarbon group, R2 is a substituted or unsubstituted monovalent hydrocarbon group, n is 0 or 4 or less positive integer, O<a≦3.0≦b<3, O<a+b≦3) Hydrolyzable group selected from hydroxyl group and/or halogen atom, alkoxy group having 1 to 10 carbon atoms, C is 1.2 or 3, d is 0
．． 1 or 2, e is 1.2 or 3, organosilane or its partial hydrolyzate represented by c+d+e=
The present invention provides a vulcanizable rubber composition comprising 0.1 to 300 parts by weight of a vulcanizing agent in an amount sufficient to vulcanize components (C) and (A).

The present invention will be explained in detail below.

The fluororubber polymer as component (A) used in the present invention contains 10 mol% vinylidene fluoride as a constituent monomer unit.
This content is necessary to form a bond with the amino group in the silicone compound of component (B) according to the following formula.

De-HF ~~CF, -CH,~~--→ ~~CF=CHC [Component (A)] Other unsaturated monomers to be copolymerized with vinylidene fluoride are not particularly limited, but for example, , tetrafluoroethylene, trifluoroethylene, vinyl fluoride, chlorotrifluoroethylene, hexafluoropropylene, perfluorocyclobutylene, perfluoroalkyl vinyl ethers, polyfluoroacrylic acid.

Examples include polyfluorovinyl ether sulfonic acid, polyfluorodienes, ethylene, propylene, vinyl ethers, and the like. These copolymerized polymers are vulcanized by polyol vulcanization or polyamine vulcanization, but they do not contain unsaturated bonds or iodine.

Peroxide vulcanization is also possible by introducing a halogen atom such as bromine. Commercially available fluororubbers include phosphazene,
Most fluororubbers other than perfluoro rubbers, tetrafluoroethylene/propylene rubbers, etc. can be used as the component (A) of the present invention.

The silicone compound (B) component used in the present invention is:
It is an essential component to improve the cold resistance of the fluororubber polymer of component (A), and as mentioned above, the reaction between the amino group in component (B) and the vinylidene fluoride in component (A) The component and component (B) are chemically combined.

The molecular weight and amine equivalent of component (B) are not limited, and the -R1- group may be bonded to the side chain of silicone or to the terminal. .Specifically, Me Me Me Me Me Me Me HJCiH4NHC*HaSi(OMe)s, HJC
JaSi(OEt)s.

HJCzH4NHCsHsSLMe(OMe)* (
(Me represents a methyl group and Et represents an ethyl group) or partial hydrolysates of these alkoxysilanes. These may be used alone or as a mixture of two or more.

The blending amount of component (B) with respect to 100 parts by weight of component (A) was 0.1 to 300 parts by weight, but this is because the effect of component (B) is not sufficient if it is less than 0.1 part by weight. 300
This is because if the amount exceeds 1 part by weight, the properties of the fluororubber, which is component (A), will deteriorate significantly.

Components (A) and (B) react easily when kneaded in a normal kneading device, and both are micro-uniformly mixed, resulting in good processability (the component (B) does not bleed out). Not at all.

At this time, by adding an acid acceptor or heating, (A)
It is also possible to accelerate the reaction between the component and component (B).

The vulcanizing agent used as component (C) in the present invention is selected from one that is suitable for the method of vulcanizing the fluororubber polymer as component (A).

For example, when component (A) is a polyol-vulcanized polymer, a polyhydroxy compound.

A vulcanizing agent consisting of a combination of an organic onium compound and an acid acceptor is preferably used, and when component (A) is an amine-vulcanized polymer, a carbamate compound or a Schiff base compound as a polyamine compound or a derivative thereof and an acid acceptor are used. A combination of vulcanizing agents is used, and when component (A) is a peroxidically vulcanized polymer, an organic peroxide is used as the vulcanizing agent.

Various fillers, processing aids, vulcanization aids, pigments, internal mold release agents, etc. can be added to the vulcanizable rubber composition of the present invention depending on the application, but the types and The blending amount is not particularly limited.

As described above, the vulcanizable rubber composition of the present invention does not cause phase separation, which occurs when simply kneading fluororubber and silicone rubber, even after time has passed, and can be instantly rolled. Moreover, it can be easily molded by conventional methods such as press molding or extrusion molding, and the vulcanized rubber elastic body exhibits excellent mechanical strength and has excellent heat resistance, cold resistance, oil resistance, and weather resistance. .

[Function] As mentioned above, in the present invention, the amino group in the silicone component (B) forms a chemical bond with the vinylidene fluoride moiety in the fluororubber polymer (A), and It is believed that this provides a rubber composition with improved cold resistance and excellent processability.

[Example] Next, the present invention will be explained with reference to an example. In the examples, parts indicate parts by weight.

The amino-modified silicone shown in the formula below was used.

(Viscosity 500 centistokes) (Viscosity 4000 centistokes, amine equivalent 4000 centistokes)
) (viscosity 1000 centistokes, m:n = lOO
+1) For comparison, MezSiO(SiO)nsiMex.

Me (viscosity 500 centistokes, m: n=100:
1) (Viscosity 10' centistokes, m: n=1
00:1) (hereinafter, Me represents a methyl group and Vi represents a vinyl group).

These were mixed in a kneader according to the composition shown in Table 1,
After reaching a uniform state, it was discharged. Next, the discharged rubber is 2
It was wound around a roll and its workability was evaluated. In addition, after the sheet was taken out, we observed that silicone was bleeding onto the surface.

Next, this was press vulcanized (170°C, 10 minutes, heat and pressure), and then subjected to secondary vulcanization (230°C).

The material was baked in an oven for 8 hours and its physical properties were evaluated.

Examples of fluororubber include Tecnoflon NML (manufactured by Cente Fluos, polyol vulcanized type), Tecnoflon P-
1 (manufactured by Sentefluos, organic peroxide vulcanization type),
Paiton B-50 (manufactured by DuPont, amine vulcanization type)
was used.

The results are also listed in Table-1.

[Effects of the Invention] The vulcanizable rubber composition of the present invention has no silicone bleed phenomenon and is easy to process, and after vulcanization, it has excellent mechanical strength, heat resistance, cold resistance, oil resistance, It has excellent chemical resistance, fuel oil resistance, and weather resistance.
This method solves the problem that the blending effect was small due to poor processability and low co-vulcanization in the conventional method, and the industrial benefits are extremely large.

Since the rubber composition of the present invention has such properties, it can be used as backings, O-rings, and hoses in transportation facilities such as automobiles, ships, and aircraft.

It is suitable for use in sealing materials, diaphragms, valves, similar parts in chemical plants, atomic couplants, food plants, and general industrial parts.

Claims (1)

[Claims] (1) (A) 10 vinylidene fluoride as a constituent monomer unit
100 parts by weight of fluororubber polymer containing mol% or more (B) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (Here, R^1 is a divalent hydrocarbon group, R^2 is a substituted or unsubstituted Monovalent hydrocarbon group, n is 0 or a positive integer of 4 or less, 0<a≦3, 0≦b<3, 0<a+b≦3) Organosiloxane and/or general formula ▲ Numerical formula, chemical formula , tables, etc. ▼ (R^1, R^2, n are the same as above, X is a hydrolyzable group selected from a hydroxyl group and/or a halogen atom, an alkoxy group having 1 to 10 carbon atoms, c is 1, 2 or 3, d is 0, 1 or 2, e is 1, 2 or 3, c+d+e=4) or its partial hydrolyzate 0.1 to 30
0 parts by weight (C) A vulcanizable rubber composition consisting of a sufficient amount of vulcanizing agent to vulcanize component (A)