JPS6351441A - Composition for vulcanizing fluororubber - Google Patents

Abstract

PURPOSE:To obtain the titled composition, containing a fluororubber, metal oxide, etc., polyhydroxy aromatic compound and specific amine, etc., and capable of providing vulcanized fluororubber having improved rubber-like properties, particularly large elongation and small compression set. CONSTITUTION:A vulcanizing composition consisting of (A) 100pts.wt. fluororubber, preferably vinylidene fluoride/hexafluoropropene bipolymer, (B) 2-30pts.wt. one or more selected from metal oxides, metal hydroxides and blends thereof with weak acid metal salts, (C) 0.5-5pts.wt. polyhydroxy aromatic compound, e.g. bisphenol A, etc., and (D) 0.2-10pts.wt. 1,6- diazabicyclo[4,3,0]-5-nonene, an organic acid salt thereof or quaternary ammonium salt expressed by formula II (R is 1-24C alkyl or 7-20C aralkyl; X is halide, hydroxylate, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluororubber vulcanizing composition suitable for producing vulcanized fluororubber having excellent properties.

[Prior art] Fluororubber has excellent heat resistance, chemical resistance, weather resistance,
Due to its cold resistance, demand is increasing for gaskets, sealing materials, diaphragms, pipes, and many other fields.

The properties required for vulcanized fluororubber are that it has rubber-like properties and low compression set, but in general, if vulcanized fluororubber has excellent rubber-like properties, it can be compressed easily. If the permanent set is large and the compression set is small, the rubbery properties tend to be poor. Therefore, there are strong expectations for the development of a fluororubber vulcanizing composition that provides a vulcanized fluororubber with low compression set without impairing its excellent rubber properties.

Japanese Patent Publication No. 52-8863 describes 1,8-diazabaincro[5,4,
Compositions containing quaternary ammonium compounds are disclosed.

However, the elongation of the vulcanized fluororubber was not sufficient, and the compression set sometimes increased as the thickness decreased.

[Object of the Invention] An object of the present invention is to provide a fluororubber vulcanizing composition that provides a vulcanized fluororubber with excellent rubber properties, particularly elongation, and excellent permanent compression set (T).

[Purchase of the Invention The above-mentioned purpose is to provide a compound selected from the group consisting of (a) fluororubber, (b) metal oxides, metal hydroxides, and mixtures of these metal oxides or metal hydroxides with metal salts of weak acids. (c) a polyhydroxy aromatic compound, and (d) an amine of the formula or its organic acid group or an organic acid group thereof;
R: earth, alkyl group having 1 to 24 carbon atoms, where carbon number is 7
-20 aralkyl groups, and X is an aralkyl group such as a halide, hydroxylate, alkoxylate, calphoquine, phenoxide, sulfonate, sulfate, sulfide, carbonate, etc. A composition for vulcanizing fluororubber containing a quaternary ammonium compound shown in (5) is described.

The fluororubber component (a) is a highly fluorinated elastic copolymer. These copolymers include, for example, copolymers of vinylidene fluoride and its fluorine-containing olein, such as vinylidene fluoride and hexafluoropropene, pencfluor[lpropene,
Examples include copolymers with one or more of trifluoroethylene, triple chloroethylene, tetrafluoroethylene, vinyl fluoride, perfluoro(methyl vinyl ether), and perfluoro(propyl vinyl ether). Preferred among these are vinylidene fluoride/hexafluoropropene binary copolymer and vinylidene fluoride/tetrafluoroethylene/hexafluoropropene ternary copolymer.

Component (b) is, for example, an oxide or hydroxide of magnesium, calcium, lead, zinc, etc., or a mixture of the oxide and hydroxide; and a metal salt of a weak acid. Preferred metal salts of weak acids include useful salts of stearic acid, benzoic acid, carbonic acid, soylic acid, phosphorous acid, etc., such as barium, sodium, and potassium.

(c) As a polyhydroquinone aromatic compound with Ii of 72 minutes, 2,2-bis(4-hydroquinphenyl)propane (
Bisphenol A), 2,2-bis(4-hydroquinphenyl)perfluoropropane (bisphenol AF)
, resorcinol, t,3.5-)lihydroquinobenzene,
1.7-dihydro [1 quinonaphthalene, 2゜7-nohydroquinonaphthalene, 1.6-cyhydroquinonaphthalene, 4
．． 4°-dihydroxydiphenyl, 4,4°-hydroxystilbene, 2,6-dihyde [l xyanthracene, hydroquinone, catechol, 2.2-bis(4-hydroxyphenyl)butane (bisphenol B), 4.
4-bis(4-hydroxyphenyl)kichi 1゛, 1 acid, 2
．． 2-bis(=1-hydroquinphenyl)tetrafluoronochloropropane, 4.4'-dihydroquinodiphenylsulfone, 4.4°-dihydroquinodiphenylketone, tri(4-hydroxyphenyl)methane, 3.3',
5,5°-tetrachlorobisphenol A, 3.3',
Examples include 5.5°-tetrabromohisphenol A. Furthermore, these alkali metal salts or alkaline earth metal salts may be used.

Component (d) is 1,6-diazabaincro[4,3,0
co-5-nonene, its organic acid salt, or its quaternary ammonium compound. Examples of acid salts include salts with phenol, acetic acid, and the like. Examples of the quaternary ammonium compound include 6-methyl-1,6-diazabaincro[430-5-nonenium chloride, 6-methyl-1,6-diazabaincro[4,3,0]-5-nonenium iodide, 6-Methyl-1,6-diazabaincro[4,3,0]-5-noneniumhydroxide, 6-methyl-1,6-diazabaincro[4,
3,O]-5-nonenium-methyl sulfate, 6-
Ethyl-1,6-cyazabaincro[43,o]-s-
nonenium bromide, 6-propyl-1,6-diazabaincro[4,3,O]-5-nonenium bromide, 6-dodecyl-1,6-diazanocyclo[4,3
,O]-5-nonenium chloride, 6-dodecyl-1
, 6-cyazabaincro[4,30]-5-nonenium hydride a oxide, 6-nicoisil-1,6-cyazabicyclo[4,3,O]-5-nonenium chloride, 6-titracosol-1,6-tzazabaincro[= 1
．． 3.0]-5-nonenium chloride, 6-benzyl-1,6-cyazabaine chloride C4,3,01-5-nonenium hydroxide, 6-phenethyl-1,6-
Examples include tazabainochlo[4,3,0]-5-nonenium chloride, 6-(3-phenylpropyl)-1,6-diazabainochlo[4,3,0]-5-nonenium chloride.

Fluororubber (a) l O0 parts (parts by weight, the same applies hereinafter)
The amount of each vulcanization additive used for component (b) is usually 2
~30 parts, especially 5 to 20 parts, component (c) is 0.5
~5 parts, especially 1 to 2 parts, or component (d) is 0.
It is preferably 2 to 10 parts, especially 0.5 to 3 parts. If the amount of component (d) used is less than the above range, the vulcanization of the fluororubber will generally be insufficient, while if it is more than the above range, the rubbery properties will tend to be impaired.

In the present invention, the above-mentioned excellent effects can be sufficiently achieved only by using the above-mentioned additives, or if necessary, the addition of carbon black, limestone, clay, diatomaceous earth, talc, etc. It can be combined with a strong agent or a li-strengthening agent.
Furthermore, if necessary, a small amount of one or more conventionally known vulcanizing agents may be added as long as it does not depart from the spirit of the present invention. Moreover, a plasticizer and a coloring agent can also be further added.

The composition thus obtained is vulcanized by a conventional method, but for example, the composition may be kneaded, placed in a mold and pressurized for primary vulcanization, and then subjected to secondary vulcanization. Can be mentioned. Generally, the conditions for primary vulcanization are a temperature of 100 to 200°C;
Time 10-180 minutes, pressure 20-l OOkg/ax'
The conditions for secondary vulcanization are a temperature of 15%.
The temperature is 0 to 300°C and the time is 0 to 30 hours. Other vulcanization methods include vulcanization after preforming such as injection or extrusion, or vulcanization of ketones such as methyl ethyl ketone, acetone, and cyclohexanone, methyl ethyl ether, noethyl ether, nooxano, and tetrahydrofuran. A solution or dispersion using one or more ethers as a medium is prepared, and the solution or dispersion is used for paper, fiber, film, paper, temporary, duplex, etc.
A method of coating and vulcanizing the surface of pipes, tanks, large containers, and other molded products (made of wood, synthetic resin, metal, etc.) can be effectively implemented.

Effects of the Invention] According to the present invention, a vulcanized fluororubber can be obtained which has excellent rubber properties such as modulus, tensile strength, elongation, and hardness, and which has an extremely small compression set.

In particular, it has the advantage of high elongation and almost no increase in compression set due to a decrease in rubber thickness.

The vulcanized fluororubber obtained from the composition of the present invention has excellent heat resistance, cold resistance, and chemical resistance, similar to vulcanized fluororubber products obtained using conventionally known vulcanizing agents, and has excellent heat resistance, cold resistance, and chemical resistance. The industrial and economical value (111) is very large because it exhibits remarkable effects that cannot be obtained by conventional methods such as.

[Examples] Next, the present invention will be specifically explained with reference to Examples and Comparative Examples.

Example 1 100 parts of fluororubber (vinylidene fluoride/hexafluoropropene elastomeric solid), medium thermal carbon, 75 gn oxide, calcium hydroxide, bisphenol A and 6-benzyl-1,6-
Ciazabicyclo[4,3゜0]-5-nonenium chloride was sequentially added and mixed on a rubber roll at room temperature.
The mixture was left to mature overnight.

After that, knead it again, put it in the mold, and check the temperature! 70
Primary vulcanization was carried out by treating at ℃ for 10 minutes under pressure to form sheets and blocks, respectively.

Next, it is removed from the mold and placed in a furnace at a temperature of 230°C.
The secondary vulcanization was completed by heating for 24 hours.

Regarding the thus obtained vulcanized fluororubber sheet 10
0% modulus, tensile strength, elongation, hardness and compression set were measured according to JIS K6301.

The formulation and test results are shown in Table 1.

Example 2 and Comparative Example 1 Example 1 According to the same procedure as in Example 1, the compositions shown in Table 1 were prepared, vulcanized, and tested. In Comparative Example 1, the composition described in Japanese Patent Publication No. 52-8863 was used.

The test results are shown in Table 1.

It can be seen that the composition of the present invention has a large elongation when compared to the conventional product of Comparative Example 1, and no increase in compression set due to thickness reduction is observed.

Claims (1)

[Claims] 1. A substance selected from the group consisting of (a) fluororubber (b) metal oxides, metal hydroxides, and mixtures of these metal oxides or metal hydroxides with metal salts of weak acids. (c) a polyhydroxy aromatic compound; and (d) an amine or an organic acid salt thereof represented by the formula: ▲a mathematical formula, a chemical formula, a table, etc.;
Chemical formulas, tables, etc. are available▼ [In the formula, R is an alkyl group having 1 to 24 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and X is a halide, hydroxylate, alkoxylate, carboxylate,
Anions such as phenoxide, sulfonate, sulfate, sulfite, and carbonate. ] A fluororubber vulcanizing composition comprising a quaternary ammonium compound represented by the following.