JPH04180930A - Vulcanizablke 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 strengths and other properties of a vulcanizate by mixing a fluororubber polymer with a specified organosiloxane and/or an organosilane or its partial hydrolyzate, an organopolysiloxane and an organic peroxide. CONSTITUTION:This composition comprises 100 pts.wt. fluororubber polymer (A) which can be vulcanized with an organic peroxide, 0.1-300 pts.wt. organosiloxane of formula I (wherein X is monovalent alkenyl, iodine or bromine; Rf is an (un)iodinated and/or (un)brominated 2C or higher bivalent fluorohydrocarbon group; Y is a bivalent group such as -COO-R<2>- (wherein R<2> is a bivalent hydrocarbon group); R<1> is a (substituted) monovalent hydrocarbon group ; 0<a<=3; 0<=b<3; and 0<a+b<=3] and/or organosilane of formula II (wherein X, Rf, Y and R are as defined above; (q) is hydroxyl and/or a hydrolyzable group selected from halogen and a 1-10 C alkoxy ; (c) is 1-3 ; (d) is 0-2 ; (e) is 1-3 ; and (c+d+e)=4) or its partial hydrolyzate (B), 3-3000 pts.wt. organopolysiloxane (C) and an organic peroxide (D).

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 properties of heat resistance, oil resistance, and weather resistance, and has been suitably used as rubber parts for automobiles such as oil seals, O-rings, and fuel hoses. However, on the other hand, 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, making it difficult to knead them to obtain a homogeneous mixture, and the processability of the resulting mixture was 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 despite the excellent rubber properties of each component, and it is difficult to bring out the characteristics of both components. The current situation is that there is no one.

[Problems to be Solved by the Invention] The present invention has been made against the background of the technical problems of the prior art described above, and is based on a polyfluoroalkyl group having a reactive group that can be crosslinked with a fluororubber polymer and an organic peroxide. By mixing the contained silicone polymer at the time of blending the fluororubber and silicone polymer, the microdispersibility of the two is significantly improved, and the unvulcanized rubber composition does not undergo phase separation, and upon vulcanization, the fluororubber polymer The purpose is to provide a vulcanizable rubber composition that has excellent roll workability, mechanical strength, heat resistance, cold resistance, oil resistance, and weather resistance by chemically bonding silicone and S. It is.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems. (A) 100 parts by weight of a fluororubber polymer that can be vulcanized with an organic peroxide (B) General formula (where X is a monovalent alkenyl group, an iodine atom, a group selected from a bromine atom; Hydrogen group, Y bar SO, NH(CH,C)1.
N), -R2- (n is O or a positive integer of 4 or less, R2
is a divalent hydrocarbon group, zl is a hydrogen atom or X-Rf-
Y-3O,-),-CONH4CHtCH,N>+1
-R''-(n, R'' are the same as above, Z2 is a hydrogen atom or X-R,-, Y-GO-), (CH2), -(
n is the same as above) or -COO-R"- (R" is the same as above), R' is a substituted or unsubstituted monovalent hydrocarbon group, O<a≦3 .0≦b<3, O
<a+b≦3) Organosiloxane and/or general formula (X, Rt, Y, R' are the same as above, Q is composed of a hydroxyl group and/or a halogen atom, an alkoxy group having 1 to 10 carbon atoms) Equipment decomposable group, C is 1, 2 or 3, d is 0°1 or 2.e is 1, 2 or 3, C+d
10e=4) Organosilane or its partial hydrolyzate
0.1 to 300 parts by weight (C) 3 to 3,000 parts by weight of organoborisiloxane (D) Vulcanizable compound consisting of an organic peroxide in an amount sufficient to vulcanize components (A) and (C). A rubber composition is provided.

The present invention will be explained in detail below.

As the fluororubber polymer used in the present invention as component (A), any fluororubber polymer that can be vulcanized with an organic peroxide can be used. Such fluororubbers include vinylidene fluoride/propylene hexafluoride, vinylidene fluoride/propylene hexafluoride/ethylene tetrafluoride, vinylidene fluoride/fluoro(alkyl vinyl) ether, vinylidene fluoride/ethylene tetrafluoride/ Fluoro(alkylvinyl)
Copolymer rubbers such as ether, tetrafluoroethylene/fluoro(alkylvinyl)ether, and combinations of tetrafluoroethylene/propylene are preferably used. Usually, these are vulcanized with peroxide by introducing an unsaturated bond into the main chain or introducing iodine or bromine into the carbon of the main chain or side chain. Any sulfur site can be used and is not particularly limited.

The silicone compound (B) component used in the present invention is:
It is an essential component for improving the cold resistance of the fluororubber polymer (A) and improving the compatibility between the fluororubber polymer (A) and the silicone (C).

As mentioned above, this material contains a fluorine-containing hydrocarbon group bonded to an alkenyl group, an iodine atom, or a bromine atom, which is a reactive group that can be crosslinked with a fluororubber polymer and an organic peroxide, so that it can be used after vulcanization. Fluororubber polymer (
The silicone part in the component (B) is chemically bonded to the silicone part in the component (B) via a fluorine-containing hydrocarbon group, and the silicone part in the component (B) has good compatibility with the silicone in the component (C).
This improves the compatibility of components (A) and (C). Furthermore, the silicone portion in component (B) and component (C) are vulcanized at the same rate by the organic peroxide, and both are co-vulcanized. As a result, the problems of the conventional technology of low compatibility and low co-vulcanization between fluororubber and silicone polymer are solved, and the (A), (B) and (C) components A rubber composition is obtained in which the particles are microscopically uniformly dispersed.

The molecular weight/reactive group equivalent of component (B) is not particularly limited. It can be anything.

As the X-Rf -Y- group, I(CFi)-CONICJa-, I(CFi)nCO
NHCJ4NHCsHs-.

CFz”CFOCFaCFxSOaNHCJ4NHCs
)Is-.

CF,=CFO(CF,)llCOOC,H,−,CF
,=CF-CONHC,H,-.

CF! = CF −C00Cs Hs −.

I(CFx)llO-CFxCFaSOaNHCsHs
- etc., and the component (B) which is a silicone compound in which these are bonded is X -Rt -Y-S L (OMe) s *
-Rt -Y-S l (OEt) m +X-R
e-Y-SiMe (OMe) s and above, Me is a methyl group, Et is an ethyl group, and Vi is a vinyl group, or partial hydrolysates of these alkoxysilanes can be mentioned. These may be used alone or as a mixture of two or more types.The organopolysiloxane (C) component used in the present invention may be mixed with the (A) component in the presence of the (B) component. As a result, the cold resistance of component (A) is improved, and the mechanical strength of component (C) is also improved by component (A).

Component (C) has the general formula Ra5iO14-a+zz (R
is a substituted or unsubstituted monovalent hydrocarbon group, a hydrogen atom.

A linear or branched silicone compound represented by a group selected from a hydroxyl group and an alkoxy group, 1<a and 3), including dimethylpolysiloxane, dimethylsiloxane-methylvinylsiloxane copolymer, and methylhydrodienepolysiloxane. , dimethylsiloxane-methylhydrodienesiloxane copolymer, dimethylsiloxane-methylphenylsiloxane-methylvinylsiloxane copolymer, 3.3.3-)lifluoropropylmethylpolysiloxane, 3,3.3-trifluorobrobylmethyl Examples include siloxane-methylvinylsiloxane copolymer. These can be used alone or as a mixture of two or more.

The organic peroxides of component (D) used in the present invention are components (A,) and (C) that have different vulcanization reactivities.
A polyfluoroalkyl group in component (A) and component (B) that are vulcanizing agents and have the same reactivity, and a silicone moiety in component (C) and component (B) that have the same reactivity. It is also a vulcanizing agent, thereby (A).

(B) and (C) components are chemically bonded by vulcanization,
The result is a rubber with a uniform continuous phase. In general, organic peroxides that easily generate peroxy radicals in the presence of heat or a redox system are preferred, such as l, l-E's (
t-butylperoxy) -3,5,5-1-limethylcyclohexane, 2,5-dimethylhexane-2,5
-dihydroxy peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α°-bis(t-butylperoxy)-p-diisopropylbenzene, 2.5-dimethyl- 2,5-di(t-butylperoxy)hexane.

Examples include 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, benzoyl peroxide, t-butylperoxybenzene, and t-butylperoxyisopropyl carbonate. Among them, dialkyl type compounds are preferred, and the type and amount used are generally selected based on the amount of active -〇-〇-, decomposition temperature, etc.

Furthermore, in organic peroxide vulcanization, effects can be seen by appropriately using a crosslinking aid or co-crosslinking agent. In principle, these are effective as long as they have reactive activity against peroxy radicals and polymer radicals.
The type thereof is not limited, but preferred ones include triallyl cyanurate, triallyl isocyanurate, triallyl formal, triallyl trimellitate,
Examples include N,N-m-phenylene bismaleimide, dibropargyl terephthalate, diallyl phthalate, tetraallyl terephthalamide, triallyl phosphate, and the like.

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 amount is not particularly limited.

Components (A), (B), and (C) can be easily and uniformly mixed by kneading them using a common mixer.

As described above, the vulcanizable rubber composition of the present invention does not undergo 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 silicone compound as component (B) has a site that is compatible with each of the fluororubber polymer and the silicone polymer, and further has a site that has equal vulcanization reactivity with each of the fluororubber polymer and the silicone polymer. It is thought that the characteristics of both can be fully brought out by microscopically uniformly mixing the fluororubber polymer and the silicone polymer and chemically bonding them through vulcanization.

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

Fluororubbers that can be vulcanized with organic peroxide include Aflas 150P (manufactured by Asahi Glass Co., Ltd.) and Aflas 200P (manufactured by Asahi Glass Co., Ltd.).
[manufactured by Asahi Glass Co.], Tecnoflon P-1° (manufactured by Montefluos), and Paiton GLT (manufactured by DuPont) were used.

The following silicone compounds were used as component (B).

NHSOaCFtCF, 0CF=CF (Viscosity 10,000 centistokes) (Viscosity 20,000 centistokes) (C) As an ingredient MesSLMSiO), lsiMes.

Me (viscosity 106 centistokes) (viscosity 10' centistokes, m: n=100:
1) was used.

(In the above, Me represents a methyl group and Vi represents a vinyl group.) These were mixed in a niegu according to the composition shown in Table 1, and after becoming uniform, they were discharged. Next, the discharged rubber was wound around two rolls to evaluate processability. Also, after taking out the sheet,
Bleeding of silicone onto the surface was observed.

Next, this was press vulcanized (170"C, 10 minutes.

heat and pressure) and further secondary vulcanization (230"C, 8 hours.

oven) to evaluate physical properties.

The results are also listed in Table-1.

[Effects of the Invention] The vulcanizable rubber composition of the present invention does not cause silicone bleed (it is easy to process), and after vulcanization, it has excellent mechanical strength, heat resistance, cold resistance, oil resistance, Chemical resistant, fuel oil resistant.

It has excellent weather resistance, and it solves the problem that conventional methods had poor processability and low co-vulcanization, resulting in small blending effects, and the industrial benefits are extremely high. big.

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 applications such as seals, diaphragms, valves, similar parts in chemical plants, nuclear couplants and food plants, and general industrial parts.

Claims (3)

[Claims] (1) (A) 100 parts by weight of fluororubber polymer that can be vulcanized with organic peroxide (B) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (Here, X is a monovalent alkenyl group, A group selected from an iodine atom and a bromine atom, R_f is a divalent fluorinated hydrocarbon group having 2 or more carbon atoms containing or not containing an iodine atom and/or a bromine atom, Y is a ▲ mathematical formula, a chemical formula,
There are tables, etc. ▼ (n is 0 or a positive integer of 4 or less, R^2 is a divalent hydrocarbon group, Z^1 is a hydrogen atom or X-R_f-Y-SO
_2-), ▲Mathematical formulas, chemical formulas, tables, etc.▼ (n, R^2 are the same as above, Z^2 is a hydrogen atom or
-R_f-Y-CO-), ▲Mathematical formulas, chemical formulas, tables, etc.▼(n is the same as above) or -COO-R^2-(
R^2 is a divalent group selected from (same as above), R^1
is a substituted or unsubstituted monovalent hydrocarbon group, 0<a≦3,
0≦b<3, 0<a+b≦3) Organosiloxane and/or general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (X, R_f, Y, R^1 are the same as above, Q is a hydroxyl group and/or a hydrolyzable group selected from 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) Organosilane or its partial hydrolyzate 0
．． 1 to 300 parts by weight (C) 3 to 3,000 parts by weight of organopolysiloxane (D) A vulcanizable rubber composition consisting of an organic peroxide in an amount sufficient to vulcanize components (A) and (C). thing (2) In the monovalent hydrocarbon group R^1 of component (B),
The vulcanizable rubber composition according to claim 1, wherein at least one R^1 in one molecule of component (B) is an alkenyl group. (3) The vulcanizable rubber composition according to claim 1 or 2, wherein component (C) is an organopolysiloxane containing at least two silicon-bonded alkenyl groups in one molecule.