JPH0335045A - Fluorine-containing elastomer vulcanizable composition - Google Patents

Abstract

PURPOSE:To obtain a fluorine-containing elastomer composition, excellent in vulcanization characteristics, scorch resistance, etc., and capable of providing vulcanizates excellent in compression set resistance, etc., by blending a fluorine- containing elastomer copolymer with a specific amount of an 8-benzyl-1,8- diazabicyclo[5.4.0]-7-undecenium salt, etc. CONSTITUTION:A composition obtained by blending (A) 100 pts.wt. fluorine- containing elastomer copolymer (e.g. vinylidene fluoride-hexafluoropropene copolymer) having vinylidene fluoride units and one or more fluorine-containing monomer units with (B) 0.05-1 pt.wt. 8-benzyl-1,8-diazabicyclo[5.4.0]-7-undecenium salt (provided that anion is halogen, etc.), (C) 0.1-5 pts.wt. sulfone compound (e.g. dimethyl sulfone) expressed by the formula (R<1> and R<2> are 1-4C alkyl), (D) 0.1-10 pts.wt. polyhydroxy compound (e.g. bisphenol AF) and (E) 0.5-30 pts.wt. divalent metal oxide or divalent metal hydroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel vulcanized composition of a fluorine-containing elastomer. More specifically, the present invention provides a fluorine-containing elastomer vulcanizate that has particularly excellent compression set resistance, heat resistance, oil resistance, and chemical resistance. The present invention relates to a fluorine-containing elastomer vulcanizable material that has vulcanization properties and is also excellent in scorch resistance and mold release properties.

[Conventional technology]

Fluorine-containing elastomer vulcanizates have excellent heat resistance, 7° oil resistance, chemical resistance, etc., so they are used in various industrial fields, such as automobiles, ships, aircraft, hydraulics, general machinery industry, and pollution control. In related departments, ○-rings, gaskets, oil seals, diaphragms, hoses, rolls,
Although it is widely used as a sheet material, compression permanent set resistance is particularly required when a fluorine-containing elastomer vulcanizate is used as a sealing material.

Vulcanization of fluorine-containing elastomers is carried out using aliphatic cyanocarbons, polyhydroxy compounds, and organic peroxides as crosslinking agents. Among the three types of crosslinking agents, especially when compression set resistance is required, Polyhydroxy compounds are effective for this purpose.

A vulcanization accelerator is essential for crosslinking with a polyhydroxy compound. Examples of vulcanization accelerators include quaternary phosphonium salts (Japanese Patent Publication No. 51-11138), quaternary ammonium salts (Japanese Patent Publication No. 52-38072), 8
-Alkyl (or aralkyl) -1,8-diazabicyclo(5,4,0) -7-Undecene quaternary ammonium salt (Japanese Patent Publication No. 52-8863), iminium salt (Japanese Patent Publication No. 63-62548) , 1,6-diazabicyclo(4,3,0)-5-nonene and its quaternary ammonium salt (JP-A-63-51441)
etc. are known.

However, even when such a vulcanization accelerator is used, the compression set resistance at high temperatures is not at a fully satisfactory level, and in order to improve productivity and save energy, it is necessary to shorten the press vulcanization time. Therefore, there is a problem that when the amount of the vulcanization accelerator is increased, the compression set resistance deteriorates.

As a solution to this problem, a composition using an iminium salt as a vulcanization accelerator and a sulfone compound as a vulcanization accelerating aid (Japanese Patent Application Laid-Open No. 1988-195146), as well as a quaternary phosphonium salt or a quaternary ammonium salt have been proposed. A composition using triorgano phosphorus oxide or diorgano sulfur oxide as a vulcanization accelerator has been proposed (Japanese Patent Publication No. 58-38461). In a composition using phosphorus oxide or diorgano sulfur oxide, when an adjuvant that accelerates curing is used, the physical properties of the vulcanizate, especially compression set resistance, deteriorate, and the physical properties do not deteriorate. When such adjuvants are used, the curing process is only slightly accelerated, and the composition cannot be said to fully solve the above-mentioned problems.

[Problem to be solved by the invention]

The object of the present invention is to provide a fluorine-containing elastomer vulcanizate that has improved compression set resistance at high temperatures and has the same heat resistance, oil resistance, and chemical resistance as conventional fluorine-containing elastomer vulcanizates; The object of the present invention is to provide a fluorine-containing elastomer vulcanizable composition that is easily curable and has excellent vulcanization properties, as well as excellent scorch resistance and mold release properties.

[Means for Solving the Problems] As a result of extensive research, the present inventors found that 8-benzyl-1,8-diazabicyclo( 5,4,0)
-7-Undecenium salt and a sulfone compound are used in combination, a polyhydroxy compound is used as a crosslinking agent, a divalent metal oxide or a divalent metal hydroxide, or a mixture thereof is used as an acid acceptor, and these are combined with a specific fluorine-containing elastomer. The present inventors have discovered that a composition that can be blended with a polymer can meet the above objectives, and based on this knowledge, they have completed the present invention.

That is, the present invention provides (A) a fluorine-containing elastomer copolymer having vinylidene fluoride units and at least one fluorine-containing monomer unit, (B) 8-benzyl-1,8-
Diazabicyclo(5,4,0)-7-undecenium salt (however, the anion is a halogen ion, hydroxide ion,
Thiocyano ion, tetraphenylborate ion, stearic acid, etc.) (C) a sulfone compound represented by the general formula (wherein R1 and R1 are an alkyl group having 1 to 4 carbon atoms), (D) polyhydroxy The present invention provides a fluorine-containing elastomer vulcanized composition comprising a compound and (E) a divalent metal oxide, a divalent metal hydroxide, or a mixture thereof.

In the fluorine-containing elastomer vulcanized composition of the present invention (A
) The fluorine-containing elastomer copolymer used as the component is
It has a vinylidene fluoride unit and at least one type of fluorine-containing monomer unit, and the at least one type of fluorine-containing monomer unit is, for example, hexafluoropropene, 1°1.1, 2. 3-pentafluoropropene, 3.3.3-polyfluoropropene, tetrafluoroethylene, trifluoroethylene, 1,2-difluoroethylene, dichlorodifluoroethylene, chlorotrifluoroethylene, hexafluorobutene, fluorinated vinyl ethers, fluorine Examples include alkyl vinyl ethers, perfluoroacrylic acid esters, etc.
Particularly important are hexafluoropropene and tetrafluoroethylene.

Further, as specific examples of the fluorine-containing elastomer copolymer (A), vinylidene fluoride-hexafluoropropene copolymer, vinylidene fluoride-hexafluoropropene-1,1,1,2,3-pentafluoropropene copolymers, vinylidene fluoride-hexafluoropropene-tetrafluoroethylene copolymers, and the like. Vulcanization of these copolymers is carried out using a vulcanization accelerator to cause a dehydrofluorination reaction of vinylidene fluoride units, pentafluoropropene units, etc. in the copolymers, using double bonds as crosslinking points. be exposed.

Typical examples of the 8-benzyl-1,8-diazabicyclo(5,4,0)-7-undecenium salt used as component (B) in the fluorine-containing elastomer vulcanized composition of the present invention include 8- Benzyl-1,8-diazabicyclo(5,4,0)-7-undecenium chloride, 8-benzyl-1,8-diazabicyclo(5,4,0)
)-7-undecenium bromide, 8-benzyl-1
,8-diazabicyclo(5,4,0)-7-undecenium iodide, 8-benzyl-1,8-diazabicyclo(5,4,0)-7-undecenium tetraphenylborate, 8-benzyl -1゜8-diazabicyclo(5,4,0) -7-undecenium hydroxide, 8-benzyl-1,8-diazabicyclo(5,
4,0)-7-undecenium thiocyanate and the like.

Examples of the sulfone compound used as component (C) in the fluorine-containing elastomer vulcanized composition of the present invention include dimethylsulfone, diethylsulfone, n-7'tilsulfone, and ethylpropylsulfone. Particularly preferred sulfone compounds are dimethylsulfone. It is.

In the fluorine-containing elastomer vulcanized composition of the present invention, (D)
As the polyhydroxy compound used as a component, at least one compound selected from polyhydroxy aromatic compounds and fluorine-containing polyhydroxy aliphatic compounds is preferably mentioned. Examples of polyhydroxy aromatic compounds include bisphenol A1 bisphenol AF,
resorcinol, 1.3.5-) lyhydroxybenzene,
1.7-hydroxynaphthalene, 2.7-hydroxynaphthalene, 1.6-hydroxynaphthalene, 4.
4'-dihydroxydiphenyl 4,4'-dihydroxystilbene, 2,6-dihydroxyanthracene, No.1
Hydroquinone, catechol, 2.2-bis(4-hydroxyphenyl)butane, 4.4-bis(4-hydroxyphenyl)valeric acid, 2.2-bis(4-hydroxyphenyl)butane, tetrafluorodichloropropane, 4 ．．
4'-dihydroxydiphenyl sulfone, 4.4'-dihydroxydiphenylketone, tri(4-hydroxyphenyl)methane, 3.3'5.5''-tetrachlorobisphenol A, 3.3'5.5'-tetrabromo Examples of the fluorine-containing polyhydroxy aliphatic compound include bisphenol A, 4,4'-dihydroxydiphenyl sulfide, and the like.
OCHz(CFz)zOcF(CFz)CHtol(C
Ft(CFHChCHzOH) t (Ch)i(ChCIIzOH)z (CF z) s (CFHCF gcHOH) t
Examples include (Ch)s(CFzCHtOH)i (CF2)s(CFHCF2CHzOH)z.

Among these, particularly preferred polyhydroxy compounds are:
Bisphenol AP and hydroquinone, which may also be alkali metal salts or alkaline earth metal salts. These compounds may be used alone or in combination of two or more.

In the fluorine-containing elastomer vulcanized composition of the present invention (I
E) Specific examples of metal oxides, metal hydroxides, or mixtures thereof used as components include magnesium oxide, lead oxide, calcium oxide, zinc oxide, iron oxide,
Examples include calcium hydroxide, magnesium hydroxide, lithium hydroxide, and mixtures thereof.

Regarding the blending ratio of each of the above-mentioned components in the fluorine-containing elastomer vulcanized material of the present invention, the component (B) is usually 0.05 to 1.0 parts by weight, preferably 0.05 to 1.0 parts by weight, per 100 parts by weight of the component (A). 0.1 to 0.5 parts by weight, 0 component (C)
．． 1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, (
D) a content of 0.1 to 10 parts, preferably 0
．． 5 to 5 parts by weight (E) component is 0.5 to 30 parts by weight,
It is preferably used in an amount of 1 to 20 parts by weight.

Furthermore, in the fluorine-containing elastomer vulcanized composition of the present invention, other components such as fillers and reinforcing agents such as carbon black, silica, clay, diatomaceous earth, calcium carbonate, calcium fluoride, and barium sulfate may be added as necessary. ,
Processing aids, plasticizers, coloring agents, etc. can be blended, and one or more conventionally known vulcanizing agents and vulcanization accelerators can be blended as long as they do not depart from the spirit of the present invention. You may.

The fluorine-containing elastomer vulcanized composition thus obtained is vulcanized according to a conventional method. This vulcanization method includes, for example, a method of kneading with an open kneading roll or a closed kneading roll (such as a Banbury mixer), placing the mixture in a mold and applying pressure to perform primary vulcanization, and then secondary vulcanization. Generally, the conditions for primary vulcanization are a temperature of 100 to 200°C, a time of 3 to 180 minutes, and a pressure of 20 to 100 kg/bo, and conditions for secondary vulcanization are a temperature of 150 to 300°C,
A range of 48 hours from time O is adopted. Other vulcanization methods include vulcanization after preforming such as injection or extrusion, or one or more of ketones such as methyl ethyl ketone and acetone, and ethers such as ethyl ether and tetrahydrofuran. A method is used in which a solution or dispersion as a medium is prepared, and the surface of paper, fibers, films, sheets, plates, tubes, pipes, tanks, large mold containers, molded containers, etc. is coated and vulcanized. You can also do that.

〔Example〕

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way.

In addition, the hardness (J I 5-A), 100% tensile modulus, tensile strength, tensile elongation, and compression set test (using an O-ring) of the vulcanized product were measured according to JIS K 6301, and the vulcanized product was The test was conducted using a Monsanto Oscillator Interdisk Rheometer Model 100S under the conditions of 150° C., frequency of 100 cpm, and amplitude of ±1°.

Example 1 Composition: 80 mol% vinylidene fluoride units, 20 mol% hexafluoropropene units, Mooney viscosity MLI +
10 (121°C) = 50 fluorine-containing elastomer 10
0 parts by weight was wound around an open kneading roll, and 30,111 parts of MT carbon black, 6 parts of calcium hydroxide, 31 parts of highly active magnesium oxide, and bisphenol were added.
2 parts by weight of AF, 1.8-diazabicyclo(5,4,0)
- After kneading 10.4 parts by weight of 7-undecenium 9054 and 2 parts by weight of dimethylsulfone, as it is -
It was incubated and aged at night.

After that, after the line is put into the mold, the temperature is 150"C.
Press vulcanization was carried out for 6 minutes to form a sheet and an O-ring (inner diameter 23.7 am, thickness 3.5 on).

Next, it was taken out from the mold and heated in an air circulation furnace at a temperature of 232°C for 24 hours to complete secondary vulcanization, and various tests were conducted.

Table 1 shows the mechanical properties and compression set resistance of the vulcanized molded product thus obtained.

Comparative Example 1 A vulcanized composition was prepared in the same manner as in Example 1, except that dimethylsulfone was not blended and the press vulcanization time was 15 minutes, and various tests were conducted. The results are shown in Table 1.

Comparative Example 2 L7 was used in the same manner as Comparative Example 1 except that 1.8-diazabicyclo(5,4,0)-7-unzocenium chloride was used in an amount of 0.6 parts by weight and the press vulcanization time was changed to 7 minutes. A vulcanized composition was prepared and various tests were conducted. The results are shown in Table 1.

(The following is a blank space) Table 1 [Effects of the Invention] The vulcanized composition of the fluorine-containing elastomer of the present invention has excellent vulcanization properties that allow it to be easily cured, as well as scorch resistance and mold release properties. The vulcanizate obtained from this product has excellent compression set resistance especially under high temperature atmosphere, and is superior to fluorine-containing elastomers obtained using conventionally known vulcanizing agents. Like vulcanizates, it has excellent heat resistance, oil resistance, and chemical resistance.

As described above, the fluorine-containing elastomer vulcanized composition of the present invention has extremely high industrial value.

Claims (1)

[Scope of Claims] 1. (A) a fluorine-containing elastomer copolymer having vinylidene fluoride units and at least one fluorine-containing monomer unit, (B) 8-benzyl-1,8-diazabicyclo(5 , 4,0)-7-undecenium salt (however, the anion is a halogen ion, hydroxide ion, thiocyano ion, tetraphenylborate ion, stearic acid, etc.), (C) General formula ▲ Numerical formula, chemical formula, table ▼ (However, R^1 and R^2 are alkyl groups having 1 to 4 carbon atoms), (D) polyhydroxy compounds, and (E) divalent metal oxides or divalent metal oxides. A fluorine-containing elastomer vulcanized composition containing a valent metal hydroxide or a mixture thereof. 2. The fluorine-containing elastomer vulcanized composition according to claim 1, wherein component (B) is 8-benzyl-1,8-diazabicyclo(5,4,0)-7-undecenium chloride. 3. The fluorine-containing elastomer vulcanized composition according to claim 1, wherein component (C) is dimethylsulfone. 4. The fluorine-containing elastomer vulcanized composition according to claim 1, wherein component (D) is bisphenol AF. 5, component (B) is 8-benzyl-1,8-diazabicyclo(5,4,0)-7-undecenium chloride, (
The fluorine-containing elastomer vulcanized composition according to claim 1, wherein component C) is dimethylsulfone and component (D) is bisphenol AF. 6. (B) based on 100 parts by weight of fluorine-containing elastomer
A patent claim in which the blending ratio of the components is 0.05 to 1.0 parts by weight, the blending ratio of component (C) is 0.1 to 5 parts by weight, and the blending ratio of component (D) is 0.1 to 10 parts by weight. range 1
The fluorine-containing elastomer vulcanized composition described in 2. 7. The fluorine-containing elastomer copolymer (A) according to claim 1, wherein the fluorine-containing elastomer copolymer is a vinylidene fluoride-hexafluoropropene copolymer and a vinylidene fluoride-hexafluoropropene-tetrafluoroethylene copolymer. Elastomeric vulcanized composition.