JPS61101545A - Composition for vulcanization of fluororubber - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent cure rate, consisting of a fluororubber having a specified composition, thiuram sulfide, a quaternary ammonium salt and/or a quaternary phosphonium salt, a polyhydric alcohol and Ca(OH)2. CONSTITUTION:0.1-10pts.wt. thiuram sulfide of formula I or II (wherein x' is 1-6; R<1>-R<4> are each a 1-6C hydrocarbon group), 0.1-10pts.wt. quaternary ammonium salt and/or quaternary phosphonium salt of formula III or IV (wherein Q is N, P; X is an m-valent anion; R<5> is a monovalent org. group; R<6> is a 2-12C bivalent org. group), 0.1-10pts.wt polyhydric alcohol (e.g. diethylene glycol), 0.1-50pts.wt. Ca(OH)2 and 0.1-5pts.wt., S or morpholine polysulfide of formula V are blended with 100pts.wt. fluororubber (e.g. vinylidene fluoride/hexafluoropropene copolymer).

Description

[Detailed description of the invention] (Technical field of invention) The present invention relates to a composition for vulcanizing fluororubber.

(Prior art) When fluororubber is vulcanized, it provides vulcanized physical properties such as heat aging resistance, chemical resistance, and oil resistance that are particularly superior to other types of rubber, so rubber materials that utilize these properties are developed. important as such. However, since the carbon-fluorine bond in the polymer is chemically very stable, it has been considered difficult to vulcanize it quickly and effectively.

In addition, many vulcanization systems have been proposed for halogen-containing polymers other than fluorine, such as chlorine-containing polymers, but most of them are extremely difficult to effectively vulcanize fluororubber. Are known.

(Purpose of the Invention) The inventors of the present invention have been conducting intensive studies for the purpose of obtaining a vulcanization system that can vulcanize fluororubber quickly and effectively with a force of 1, and discovered that the applicant's previous application Japanese Patent Application Publication No. 57-1493
The present invention was achieved by discovering that the vulcanization system described in Publication No. 57 can surprisingly rapidly and effectively vulcanize even fluororubber.

(Structure of the Invention) The present invention consists of the following components (a) to (e): (a) 100 parts by weight of fluororubber (
b) Thiuram sulfides 0.1 to 10 parts by weight (C
,) Quaternary ammonium salt and/or quaternary phosphonium salt 0.1 to 10 parts by weight (d') Polyhydric alcohols 0.1 to 10 parts by weight (e) Calcium hydroxide 0.1 to 50 parts by weight A fluororubber vulcanizing composition characterized by comprising:

The (a) fluororubber used in the present invention is generally a highly fluorinated elastic copolymer. Examples of these copolymers include copolymers of vinylidene fluoride and other copolymerizable fluorine-containing olefins. Examples of the copolymerizable fluorine-containing olefin include hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, Two or more types are selected. Particularly preferred among these are vinylidene fluoride-hexafluoropropene binary copolymer and vinylidene fluoride-tetrafluoroethylene-hexafluoropropene terpolymer.

The thiuram sulfide (b) used in the present invention is represented by the following general formula (I) or (I[).

S S In the above general formula (I>, (I), χ and χ' are 1 to
is an integer of 6, and R1, R2, R3 and R4 have 1 carbon number
~6 hydrocarbon residues.

Representative examples of the compounds of the above general formulas (I) and (I[) include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram hexasulfide, N
-N'-dimethyl-N,N'-diphenylthiuram disulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide, and the like.

The (C) quaternary ammonium salt or quaternary phosphonium salt used in the present invention has the following general formula (I[[) or (IV)]
It is expressed as

(R5) a Q+1(X-91/m (I[)
(R5) 3 QR' Q (R') 3''(X-
2/m (IV) In the above general formula (I), NV), Q is a nitrogen or phosphorus atom, and X is an anion of 1 dlim atom. R5 is one Ia group, which is the same as or different from any other R5, and may be combined with other R5 to form a Q-containing cyclic structure. Moreover, R5 is a straight chain, bibranched chain, or cyclic, and has a saturated, unsaturated, or aromatic carbon skeleton! ! chain, and this chain may contain heteroatoms other than carbon, such as oxygen, nitrogen or sulfur, even if substitutions are made that do not interfere with the function of the compound. It's a good base. R6 is a divalent Ii group having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms,
This is a group that may be substituted at a portion that does not interfere with the function of the compound.

In the above general formula (I[), (IV), atom lII
As the anion of m, for example, chloride, promy1
．． Sulfates, hisulfates, nitrates, hydroxides, carbonates, perchlorates, trifluoromethanesulfonates.

Examples include acetate, benzenesulfonate, phenate, tetrafluoroborate, hexachlorophosphate, hexafluorophosphate, and the like.

Preferred R in the above general formula (l[), (IV)
5 includes alkyl, alkenyl, cycloalkyl,
Examples include phenyl or combinations thereof. Preferred examples of R6 include alkylene, phenylene, and phenylene dialkylene. Furthermore, R5 and R6 can contain substituents that do not interfere with the function of the present compound, such as halogen, alkoxy, alkylthiokoxy, acetoxy, acetamide, and the like.

The following are representative examples of the quaternary ammonium salt or quaternary phosphonium salt (C) of the present invention.

(CH co)4N"OH"", (Ca Hs
)N”Cl − , (HOCH2
CH2 )3N"CH3 I-, HO- (C4H
9) 3 N"CH2 C82 N" (CaHs)
301-h. (C2H5)3 (CsHs)N”
Br-.

(Co HI3 )3 (CH-CHCH2)N"B
Fs-, (C4HS)3(CF3CH2)
N” (SOa-1m.

(C4H9)aP"Br-, (C2H5)3 (
CHsHi7)P”Br7.

(C31-I7>3 (cyclo-CaHu)P”O
H-, (C4H9)3(CH2=CHCHz)P”
CI-, (C6H5)3 (CaHsGHz)P
+CI'''. (Ca Hs )s (Cs HS C
OCH2)P"CI"-.

(d) Polyhydric alcohols used in the present invention include diethylene glycol, pentaerythritol, and trimethylolpropane. Examples include trimethy O-lethane and sorbitol, and these may be used alone or as a mixture.

The ratio of each component of the composition of the present invention is (a) 10 fluororubber
(11) Thiuram sulfides 0.0 parts by weight.
1 to 10 executive parts, preferably 0.2 to 6 executive parts, (C
) Quaternary ammonium salt and/or quaternary phosphonium 0.
1 to 10 parts by weight, preferably 0.2 to 6 parts by weight, (d)
0.1 to 15 parts by weight of polyhydric alcohol, preferably 0.1 to 15 parts by weight.
5~8!1! ltt part, (e) calcium hydroxide 0.5
A range of from 1 to 20 convex parts, preferably from 1 to 10 convex parts is appropriate.

The composition of the present invention may contain various additives, such as fillers, as commonly practiced in the art.

Reinforcing agent. Plasticizer. Processing aid. Acid acceptor, anti-aging agent. lI
B fuel, B fuel, etc. can be optionally blended. Particularly from the viewpoint of thermal stability of the composition of the present invention, it is preferable to add a metal compound or an epoxy compound to serve as an acid acceptor. Such metal compounds include oxides of Group 1 metals of the periodic table,
hydroxide. Carbonates, carboxylates. Silicate. Borate. Phosphites, oxides of metals from group 1a of the periodic table.

Salt base carbonates, basic carboxylates. Basic phosphite.
Basic sulfite. Tribasic sulfur i11j! etc. Specific examples of these include magnesia, magnesium hydroxide, and barium hydroxide.

Magnesium carbonate, barium carbonate, quicklime, calcium carbonate, calcium silicate, calcium suarate, zinc stearate. Calcium phthalate, tRM magnesium, calcium phosphite, zinc white. tin oxide, litharge,
Lead red. Lead white.

Dibasic lead phthalate, dibasic lead charcoal. Tin stearate. Basic fIA leadite. Examples include basic lead sulfite. Examples of the epoxy compound include epoxidized soybean oil, a reaction product of bisphenol A and epichlorohydrin, and the like.

The amount of addition of these metal compounds or epoxy compounds as acid acceptors is 501 parts by weight per 100 parts by weight of fluororubber.
The amount of fi is preferably 1 part or less.

In the present invention, when more rapid vulcanization of the composition is desired, it is effective to add sulfur or morpholine polysulfides represented by the following general formula (V). ``In the above general formula (V.), χ'' is an integer of 1 to 6. Representative examples of general formula (V) include morpholine disulfide, morpholine tetrasulfide, and the like.

The amount of compounding is r O for fluororubber 100 weight ffi81
．． 1-5m71Bc7) IIflllJ.

In the present invention, a part of the fluororubber in the composition may be replaced with another type of halogen-containing polymer or epoxide-containing polymer. Such polymers include, for example, chlorinated polyethylene.

Chlorinated ethylene-propylene copolymer, chlorinated ethylene-propylene-nonconjugated diene terpolymer, chlorosulfonated polyethylene, polyvinyl chloride, chlorinated acrylic rubber, epoxide-containing acrylic rubber, chlorinated butyl rubber,
Examples include brominated butyl rubber, polychloroprene, polyepichlorohydrin, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-weight ethylene oxide allyl glycidyl ether terpolymer, and the like.

The blending amount of these polymers is 80% in the mixture with fluororubber.
% by weight or less. A blend exceeding 80% by weight is not preferred because the excellent properties inherent to fluororubber are lost.

The composition of the present invention may be mixed by any means conventionally used in the field of polymer processing, such as mixing rolls, Banbury mixer 1, various kneaders, etc.
If you do this, you will be able to do this.

The above-mentioned mixed composition usually has a temperature of 0.0% at 100 to 200°C.
A vulcanizate can be obtained by heating for 1 to 300 minutes. Vulcanization molding methods include pressure molding using a mold, injection molding, and steam can.

Any method can be used, such as heating with an air pass, infrared rays, microwave, or the like.

(Effects of the Invention) The composition of the present invention has a rapid vulcanization rate and provides a fluororubber vulcanizate with excellent vulcanizable properties, so it is useful as a rubber material that can utilize the excellent properties inherent in fluororubber. It is.

(Examples) Examples 1 to 5 Comparative Example 1 Each compound shown in Table 1 was kneaded with an oven roll at 60 to 70°C to form a sheet, which was then placed in a mold and pressure-molded at 160°C for 30 minutes. did. (The physical properties of each vulcanized product were measured and the results are shown in Table 2.

Comparative Example 1 is an example in which 2-mercaptoimidacillin, which has been widely used as an effective vulcanizing agent for chlorine-containing polymers in polychloroprene, epichlorohydrin polymers, etc., is applied to fluororubber.

In addition, the vulcanization curves of the formulations of Example 1 and Comparative Example 1 were determined by JS
Using an R-type culastometer, the amplitude angle is 3' and the temperature is 16.
The measurement was carried out at 0°C and the results are shown in FIG.

As is clear from Table 2, the composition of the present invention surprisingly shows that it can rapidly and effectively vulcanize not only chlorine-containing polymers but also fluororubbers.

Notes (1) Vinylidene fluoride-hexafluoropropene binary copolymer (2) Vinylidene fluoride-tetrafluoroethylene-hexafluoropropene ternary copolymer (3) Chlorine content 40% by weight Table 2

[Brief explanation of drawings]

FIG. 1 shows the vulcanization curves of Example 1 and Comparative Example 1.

Claims (1)

[Scope of Claims] (a) Fluororubber 100 parts by weight (b) Thiuram sulfides 0.1 to 10 parts by weight (c
) Quaternary ammonium salt and/or quaternary phosphonium salt 0.1 to 10 parts by weight (d) Polyhydric alcohol 0.1 to 10 parts by weight (e) Calcium hydroxide 0.1 to 50 parts by weight Above (a) ~(e
) A fluororubber vulcanizing composition characterized by containing each component.