JPS63268757A - Composition for curing fluoro-rubber - Google Patents

Abstract

PURPOSE:To provide the titled composition improved in solubility and deliquescent nature, easy to handle, containing specific compound(s) as the curing accelerator. CONSTITUTION:The objective composition can be obtained by blending (A) pref. a fluorine-contg. elastomer, (B) pref. at least one substance selected from divalent metal oxides, divalent metal hydroxides and mixtures of metal salts of weak acids therewith, (C) pref. a polyhydroxyaromatic compound, and (D) as the curing accelerator, at least one kind of compound of formula I [R is 1-24C alkyl or 7-20C aralkyl; R<1> is of formula II (R<2> is H or methyl), etc.] or formula III.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a fluororubber vulcanizing composition, and more particularly to a fluororubber vulcanizing composition having improved solubility and deliquescent property.

<Prior art> In order to obtain a fluororubber with excellent rubbery properties and a small compression set, 1, 8 in which the 8th position is substituted with an alkyl (or aralkyl) is used as a vulcanization accelerator for the fluororubber.
- It has been proposed to use a quaternary ammonium salt of diazabicyclo[5,4,0]undecene-7 (hereinafter sometimes referred to as DnU) (Japanese Patent Publication No. 52-8863
Publication No.). However, since this vulcanization accelerator has deliquescent properties and is soluble in water, it has the disadvantage that a fluororubber vulcanizing composition containing it is difficult to handle.

<Object of the Invention> An object of the present invention is to provide a composition for vulcanizing fluororubber that is easy to handle and has deliquescent properties and solubility in water.

<Structure of the Invention> The gist of the present invention is the formula: [In the above formula, R is an alkyl group having from ■ to 24 carbon atoms or an aralkyl group having from 7 to 20 carbon atoms, (wherein R1 is ■] or methyl group, n represents 2 or 3). ] A fluororubber vulcanizing composition comprising at least one compound represented by the following as a vulcanization accelerator.

As compound (1), for example, 8-methyl-1,8
-diazabicyclo[5,4,0]-7-unzocenium 2-mercaptothiazole salt, 8-methyl-1,8-
Diazabicyclo[5,4,0]-7-undecenium
2-mercaptobenzothiazole salt, 8-ethyl-1,
8-Diazabicyclo[5°4.0]-7-undecenium 2-mercaptothiazole salt, 8-ethyl-1,8
-Diazabicyclo[5,4,0-7-undecenium 2-mercaptobenzothiazole salt, 8-propyl-
1,8-diazabicyclo[5,4,0]-7-undecenium 2-mercaptodeazole salt, 8-propyl-
1,8-diazabicyclo[5,4,0-7-undecenium 2-mercaptobenzodeazole salt, 8-dodecyl-1,8-diazabicyclo[5,4,0]-7-undecenium 2-mercaptobenzode Azole salt, 8
-eicosyl-1,8-diazabicyclo[5,4,0]
-7-undecenium 2-mercaptobenzothiazole salt, 8-tetracosyl-1,8-diazabicyclo[5
,4,O-7-undecenium/2-mercaptobenzodeazole salt, 8-benzyl-1,8-diazabicyclo[5,4,0]=7-undecenium/2-mercaptothiazole salt, 8-benzyl-1, 8-Diazabicyclo[5°4.0]-7-undecenium 2-mercaptobenzothiazole salt, 8-phenethyl-I, 8-diazabicyclo[5,4,01-7-undecenium 2-
Mercaptobenzothiazole salt, 8-(3-phenylpropyl)-t, S-diazabicyclo[5°4.0]-
Examples include 7-undecenium 2-mercaptobenzothiazole salt.

As compound (II), for example, 8-methyl-1,
8-Diazabicyclo[5,4,03-7-undecenium 2-mercaptoimidazole salt, 8-methyl-1,
8-Diazabicyclo[5,4,0]-7-undecenium/2-mercaptobenzimidazole salt, 8-ethyl-1,8-diazabicyclo[5,4,0]-7-undecenium/2-mercaptoimidazole salt, 8 -Ethyl-1,8-diazabicyclo[5,4,0]-7-undecenium 2-mercaptobenzimidazole salt, 8-
Propyl-1,8-diazabicyclo[5,4,0]-7
- unde cenium 2-mercaptoimidazole salt,
8-propyl-1,8-diazabicyclo[5,4,0]
-7-Undecenium 2-mercaptobenzimidazole salt, 8-dodecyl-! , 8-diazabicyclo[5,
4,0]-7-undecenium/2-mercaptobenzimidazole salt, 8-eicosyl-1,8-diazabicyclo[5,4,O]-7-undecenium/2-mercaptobenzimidazole salt, 8-tetracosyl 1.8
-Diazabicyclo[5°4.0]-7-undecenium 2-mercaptobenzimidazole salt, 8-benzyl-1,8-diazabicyclo[5,4,0]-7-undecenium 2-mercaptoimidazole salt, 8- Benzyl-1,8-diazabicyclo[5,4,0]-7-undecenium 2-mercaptobenzimidazole salt, 8
-Phenethyl-1,8-diazabicyclo[5,4゜0]
-7-undecenium 2-mercaptobenzimidazole salt, 8-(3-phenylpropyl)-1,8-diazabicyclo[5,4,0-7-undecenium 2-
Examples include mercaptobenzimidazole salts.

In a preferred embodiment, the fluororubber vulcanizing composition of the present invention comprises (a) a fluorine-containing elastomer, (b) a divalent metal oxide, a divalent metal hydroxide, and these metal oxides or metal hydroxides. (c) a polyhydroxy aromatic compound; and (c) a polyhydroxy aromatic compound;
d) A composition containing compound (1) or (II). In addition to components (a) to (d), the composition of the present invention may further contain (e) a metal compound that reacts with water or hydrogen fluoride to easily generate water.

Examples of the fluorine-containing elastomer as component (a) include highly fluorinated elastic copolymers. These copolymers include copolymers of vinylidene fluoride and other fluorine-containing olefins, such as vinylidene fluoride and hexafluoropropene, pentafluoropropene, trifluoroethylene, trifluorochloroethylene, tetrachloro[J Examples include copolymers with one or more of ethylene, vinyl fluoride, barfluor a (methyl vinyl ether), perfluoro (propyl vinyl ether), and the like. Particularly preferred are vinylidene fluoride/hexafluoropropene binary copolymers and vinylidene fluoride/tetrafluoroethylene/hexafluoropropene ternary copolymers.

In addition to each component of these copolymers, a small amount of vinyl compound, olefin compound, diene compound or other α
, β-ethylenically unsaturated carboxylic acid, etc. can be used effectively as well.

In addition to the fluorine-containing elastomer, ordinary organic polymer materials that can contain D[3U derivatives as processing agents,
For example, polyurethane; epoxy resin; halogen-containing polymers such as epichlorohydrin rubber, chlorinated polyethylene, chloroprene, and polyvinyl chloride; and other acrylonitrile-butadiene rubbers may be used in combination.

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

As the polyhydroxy aromatic compound which is component (c), 2,2-bis(4-hydroxyphenyl)propane (
Bisphenol-A), 2,2-bis(4-hydroquinphenyl)perfluoropropane (bisphenol-A)
F), resorcinol, 1.3.5-trihydroxybenzene, ■, 1-dihydroquinaphthalene, 2.7-cyhydroxynaphthalene, 1.6-cyhydroxynaphthalene,
4.4'-dihydroxydiphenyl, 4.4'-dihydroxydisderpene, 2.6-dihydroxyanthracene, hydroquinone, catechol, 2.2-bis(4-hydroxyphenyl)butane (bisphenol-B), 4
．． 4-bis(4-hydroxyphenyl)valeric acid, 2.2
-Bis(4-hydroxyphenyl)tetrafluorodichloropropane, 4.4°-dihydroxydiphenylsulfone, 4,4°-dihydroxydiphenylketone, tri(4-hydroxyphenyl)methane, 3,3°, 5.5
'-tetrachlorobisphenol-A, 3,3°,5,
Examples include 5°-tetrabromobisphenol-A. Particularly preferred polyhydroxy aromatic compounds include hydroquinone. Moreover, these alkali metal salts or alkaline earth metal salts may be used.

As component (e) to be added as necessary, water may be added directly, but it is preferable to use a component that releases water under vulcanization conditions and does not harm the vulcanization itself, such as Mg5O, '7H,
O, Cu5O, -5H20, Pe5o4・7 r(, O
It may also be a crystal water-containing metal salt such as. In addition, metal compounds that easily generate water by reacting with hydrogen fluoride include:
Examples include hydroxides of Mg, Pb, Ca, and the like. When these metal compounds are used, addition of component (b) may be omitted.

The usage m of each component is usually 2 to 30 parts of component (b), especially 5 to 20 parts, and 0, 5 to 5 parts of component (c) per 100 parts (parts by weight, the same applies hereinafter) of component (a). parts, especially 1 to 3 parts, and also component (d) 0, 2 to IO parts,
In particular, it is preferably 0.5 to 3 parts. component (d
) If the amount of compound (I) or (II) used is below the above range, the vulcanization of the fluorine-containing elastomer will generally be insufficient, and if it exceeds the above range, the rubber properties will be impaired. Tend. The amount of water added as component (e) is preferably 0.1 to 10 parts, particularly 0.5 to 5 parts, per 100 parts of the fluorine-containing elastomer composition. Although the amount added depends on the type, it is usually 0.5 to 30 parts, preferably 2 to 10 parts.

In the composition of the present invention, fillers and reinforcing agents such as carbon black, silica, clay, diatomaceous earth, and talc may be further blended as necessary, and if necessary, within the scope of the spirit of the present invention. If so, a small amount of one or more conventionally known vulcanizing agents may be blended. Furthermore, a plasticizer and a coloring agent can also be added.

The composition of the present invention may be vulcanized by a conventional method, such as a method in which the composition is kneaded with rolls, placed in a mold, pressurized, and subjected to primary vulcanization, followed by secondary vulcanization. Generally, the conditions for primary vulcanization are: temperature 100-200℃, time 10-180℃.
The conditions for secondary vulcanization are a temperature of 150 to 300°C and a time of 0 to 30 hours. , a method of vulcanizing after preforming such as injection or extrusion, or one or more types of ketones such as methyl ethyl ketone, acetone, and cyclohexanone, and ethers such as methyl ethyl ether, diethyl ether, dioxane, and tetrahydrofuran. A solution or dispersion liquid as a medium is used as paper, fiber, film, sheet, plate, tube, pipe, tank, etc.
Any method of coating and vulcanizing the surface of a large container or other molded product (made of cellulose, synthetic resin, metal, etc.) can be effectively carried out.

<Example> The present invention will be specifically explained below using Examples. Hereinafter, parts by weight are indicated unless otherwise specified.

Example 1 Vinylidene fluoride/hexafluoropropene/tetrafluoroethylene (66.5/16/17 in molar ratio)
．． 5) 100 parts of copolymer, 20 parts of medium thermal carbon, 10 parts of magnesium oxide, 4 parts of calcium hydroxide, 1 part of hydroquinone and 8-benzyl-1,
0.8 part of 8-diazabicyclo[5,4,0]-7-unzocenium 2-mercaptobenzothiazole salt was sequentially added and kneaded at room temperature on a rubber roll to prepare a composition for vulcanizing fluororubber, The mixture was left to mature overnight.

After that, after making the line, put it in the mold and heat it to 170℃.
Primary vulcanization was carried out at 55 kg/am' for 10 minutes at a temperature of 55 kg/am' to form a block.

Next, it is taken out from the mold and heated in a furnace at a temperature of 230°C for 2 hours.
The secondary vulcanization was completed by heating for 4 hours.

The water solubility and deliquescence of the 2-mercaptobenzothiazole salt, which is a vulcanization accelerator, were measured. Also,
The vulcanization composition was subjected to a vulcanization test using a curelastometer, and the compression set of the resulting vulcanized fluororubber blocks was measured. The results are shown in Table 1.

Solubility was visually determined by adding 1 g of the vulcanization accelerator to 9 g of water.

Deliquescence is determined by placing 1 g of vulcanization accelerator in a chalet and adding 1 g of vulcanization accelerator at room temperature.
After being left for a day, the judgment was made visually.

Comparative example 1 8-benzyl-1,8-diazabicyclo[5,4°0]
In place of 0.8 part of -7-unzocenium 2-mercaptobenzothiazole salt, 8-benzyl-1,8-diazabicyclo[5,4,O-7-undecenium chloride (described in Japanese Patent Publication No. 52-8863) compound)0.
Example I was repeated except using 5 parts. The results are shown in Table 1.

Table 1 <Effects of the Invention> Unlike the components of conventional compositions, the composition of the present invention is easy to handle because it does not have water solubility or deliquescence. Moreover, the composition of the present invention is well vulcanized,
The resulting vulcanized rubber has excellent rubbery properties and compression set.

Written amendment to the proceedings Dear Commissioner of the Patent Office May 29, 1985 2 Name of the invention Fluororubber vulcanizing composition 3 Relationship to the case of the person making the amendment Patent applicant May 20, 1988 Address changed ( Address: 2-4-12 Nakazaki Nishi, Kita-ku, Osaka, Osaka Umeda Center Building Name (285) Daikin Industries, Ltd. Representative: Yama
1) Minoru 4, agent address: 2-1-61 Mi, Higashi District, Osaka City, Osaka Prefecture 540
No. 6, Subject of amendment; Column 7 of "Detailed explanation of the invention" of the specification, Contents of amendment The following parts in the column of "Detailed explanation of the invention" of the specification will be amended.

(1) On page 2, lines 15-16, the phrase "a fluororubber vulcanizing composition containing the same" is deleted.

(2) Delete "injection or" on page 12, line 15.

(3) On page 14, line 14, the word "chalet" is corrected to "petri dish."

that's all

Claims (1)

[Claims] 1. Formula: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) [In the above formula, R is a carbon number of 1 to 24 It is an alkyl group or an aralkyl group having 7 to 20 carbon atoms, and R^1 is ▲ formula,
There are chemical formulas, tables, etc. ▼ or -(CH_2)-_n
(Here, R^2 represents H or a methyl group, and n represents 2 or 3.) ] A fluororubber vulcanizing composition containing at least one compound represented by the following as a vulcanization accelerator.