JPH06271733A - Vulcanizable fluororubber composition - Google Patents

Abstract

PURPOSE:To obtain the fluororubber compsn. which is vulcanizable without using any vulcanizing agent. CONSTITUTION:This fluororubber compsn. comprises an elastic fluorocopolymer obtd. from a fluorinated alkyl vinyl ether of formula I (wherein Rf is a 1-20C divalent polyfluoroalkylen group optionally having ether bonds with the number of oxygen atoms of 0-3; and (n) is 1 or 2) and at least one other ethylenically unsatd. monomer copolymerizable therewith and an elastic copolymer obtd. from an epoxidized vinyl ether of formula II (wherein X and X<1> are each independently H, F, or Cl; and Y is an epoxidized monovalent group optionally fluorinated) and at least one other ethylenically unsatd. monomer copolymerizable therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-vulcanizable fluororubber composition.

[0002]

2. Description of the Related Art Fluorine rubber is a material having excellent heat resistance, oil resistance, weather resistance and the like and is therefore used in a wide range of fields including automobile parts. All of these are vulcanized and molded using a vulcanizing agent such as a diamine, a polyhydroxy compound and an organic peroxide. However, the vulcanizates obtained by these vulcanization methods are not necessarily suitable for those applications, because the vulcanizing agents and vulcanization accelerators used are not suitable for medical applications, food applications, etc. There wasn't.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and there is no cross-linking agent formed by two kinds of fluororubber having vulcanizable groups which react with each other. Also provided is a vulcanizable fluororubber composition.

[0004]

[Means for Solving the Problems]
(A) Fluorine-containing alkyl vinyl ether represented by [Chemical Formula 3] and a fluorine-containing elastic copolymer with at least one other ethylenically unsaturated monomer copolymerizable therewith, (B) [Chemical Formula 4] The solution is a vulcanizable fluororubber composition comprising an epoxy group-containing vinyl ether represented by and an elastic copolymer with at least one other ethylenically unsaturated monomer copolymerizable therewith.

[0005]

[Chemical 3]

[Chemical 4]

Next, the present invention will be described in detail. Examples of the at least one other ethylenically unsaturated monomer which is a copolymerization component of the fluorine-containing elastic copolymer of the component (A) used in the present invention include, for example, vinylidene fluoride (hereinafter referred to as Vd
F), hexafluoropropene (hereinafter, HFP), 1,
1,1,2,3-pentafluoropropene, 3,3,3
-Trifluoropropene, tetrafluoroethylene (TFE), trifluoroethylene, 1,2-difluoroethylene, dichlorodifluoroethylene, chlorotrifluoroethylene, hexafluorobutene, ethylene, propylene, 1-butene, fluorinated alkyl vinyl ether And fluorinated vinyl ethers.

The fluorine-containing elastic copolymer as the component (A) is [Chemical Formula 3] -VdF-HF in view of heat resistance and oil resistance.
P copolymer, [Chemical formula 3] -VdF-HFP-TFE copolymer, [Chemical formula 3] -TFE-propylene copolymer, [Chemical formula 3]
-VdF-TFE-propylene copolymer, [Chemical Formula 3] -V
dF copolymer, [Chemical Formula 3] -VdF-perfluoroalkyl vinyl ether copolymer, [Chemical Formula 3] -VdF-TFE
-Perfluoroalkyl vinyl ether copolymer and the like are preferably used.

The fluorine-containing alkyl vinyl ether represented by [Chemical Formula 3] which is a copolymerization component of the fluorine-containing elastic copolymer of the component (A) of the present invention has a hydroxyl group in the fluorine-containing alkyl vinyl ether of the component (B). Use of a vulcanizing agent, a vulcanization accelerator or the like from the component (A) and the component (B) by reacting with the epoxy group in the alkyl vinyl ether represented by [Chemical formula 4] which is a copolymerization component of the elastic copolymer A vulcanizate is obtained without any vulcanization.

Specific examples of these fluorine-containing alkyl vinyl ethers include the following.

[0010]

[Chemical 5]

[Chemical 6]

[Chemical 7]

[0011]

[Chemical 8]

[Chemical 9]

[Chemical 10]

As the at least one other ethylenically unsaturated monomer which is the copolymerization component in the component (B), for example, VdF, HFP, 1,1,1,2,3-pentafluoropropene, 3,3,3-trifluoropropene, T
FE, trifluoroethylene, 1,2-difluoroethylene, dichlorodifluoroethylene, chlorotrifluoroethylene, hexafluorobutene, ethylene, propylene, 1-butene, fluorinated alkyl vinyl ethers,
Examples thereof include fluorinated vinyl ethers. From the viewpoints of heat resistance, oil resistance, compatibility with the fluorine-containing elastic copolymer of the component (A), etc., it is preferable to copolymerize an unsaturated monomer containing fluorine.

As the elastic copolymer of the component (B), from the viewpoint of heat resistance and oil resistance, [Chemical formula 4] -VdF-HFP copolymer, [Chemical formula 4] -VdF-HFP-TFE copolymer, [Chemical Formula 4] -TFE-Propylene Copolymer, [Chemical Formula 4] -VdF
-TFE-propylene copolymer, [Chemical 4] -VdF copolymer, [Chemical 4] -VdF-perfluoroalkyl vinyl ether copolymer, [Chemical 4] -VdF-TFE-perfluoroalkyl vinyl ether copolymer, etc. Is preferably used.

The alkyl vinyl ether represented by [Chemical Formula 4], which is the copolymerization component of the fluorine-containing elastic copolymer of the component (B) of the present invention, has the epoxy group in the alkyl vinyl ether as the component (A) as described above. Reacts with the hydroxyl group in the fluorine-containing alkyl vinyl ether represented by [Chemical Formula 3] which is the copolymerization component of the elastic copolymer of A vulcanized product can be obtained without using.

Specific examples of the alkyl vinyl ether represented by [Chemical Formula 4] include the following.

[0016]

[Chemical 11]

[Chemical 12]

[Chemical 13]

[Chemical 14]

As described above, the vulcanizate is obtained from the components (A) and (B) without using a vulcanizing agent, but by simply mixing the two and heating them. You may mix an acidic or basic substance as.

The amount of the component (B) to be used with respect to 100 parts by weight of the component (A) is determined by the copolymerization ratio of the fluorine-containing alkyl vinyl ether represented by the formula (4) in the component (B) and the required physical properties of vulcanization. However, there is no particular limitation.

The fluorine-containing elastic copolymer of the component (A) and the elastic copolymer of the component (B) of the present invention contain each monomer in the presence of a radical initiator, for example, bulk polymerization, suspension polymerization, It is produced by copolymerization by a known polymerization method such as emulsion polymerization or solution polymerization. The monomer charging system may be a batch system or a system in which additional charging is continuously carried out so that the molar ratio of the monomers in the reaction system is kept constant.

The polymerization temperature, which is determined by the decomposition rate of the radical initiator, is usually selected from the range of 0 to 150 ° C. The polymerization pressure is determined by the polymerization temperature and the polymerization method, but is usually selected from the range of 0 to 50 kg / cm ² G.

The molecular weight can be adjusted by adjusting the relationship between the copolymerization rate and the amount of the initiator, but it can be easily performed by adding a chain transfer agent.

In the fluororubber composition of the present invention, known reinforcing fillers, extenders, pigments, internal release agents, plasticizers and the like used for fluororubber may be mixed and used. To mix these vulcanization accelerators and fillers, a mixing device such as a two roll or kneader that is usually used for mixing rubber is used.

Vulcanization and molding of the fluororubber composition of the present invention can be carried out in the same manner as in ordinary fluororubber. That is, press molding, injection molding, extrusion molding and calender molding,
It is also possible to perform dip molding or coating by dissolving it in a solvent or the like. The vulcanization temperature and time vary depending on the thickness and shape of the molded product, but are generally in the range of 120 to 400 ° C. for several seconds to 5 hours. Further, in order to stabilize the properties of the vulcanized product, it is 0.5 to 4 at 150 to 300 ° C. in an oven or the like.
Secondary vulcanization may be performed for about 8 hours.

[0024]

In the present invention, by using two types of elastic copolymers having different reactivity, a fluororubber composition having good vulcanizability without using a vulcanizing agent, a vulcanization accelerator or the like. Is to give.

[0025]

【Example】

(Example 1) TFE / propylene / by emulsion polymerization
[Chemical formula 7] = 55/44/1 (molar ratio), intrinsic viscosity [η]
= 0.48 was obtained as a copolymer (fluorine rubber-1). Similarly, TFE / propylene / [Chemical formula 11] = 55/44 /
A copolymer having a 1 (molar ratio) and an intrinsic viscosity [η] = 0.55 was obtained (fluororubber-2).

50 parts of fluororubber-1 (parts by weight, the same applies hereinafter) and 50 parts of fluororubber-2 were wound around a roll and mixed to obtain a fluororubber composition. This was press-vulcanized at 180 ° C. for 30 minutes, and then secondary-vulcanized in an oven at 200 ° C. for 4 hours. As a result of measuring physical properties according to JIS K6301, hardness 64, 100% modulus 28 kg / cm ² ,
The tensile strength was 100 kg / cm ² and the elongation was 410%.

(Example 2) By the emulsion polymerization method, VdF /
A copolymer having HFP / [Chemical formula 9] = 76/22/2 (molar ratio) and intrinsic viscosity [η] = 0.58 was obtained (fluorine rubber-
3). Similarly, VdF / HFP / [Chemical formula 11] = 76
A copolymer having a ratio of / 22/2 (molar ratio) and an intrinsic viscosity [η] = 0.43 was obtained (fluororubber-4).

50 parts of fluororubber-3 and 5 parts of fluororubber-4
0 parts, 30 parts of MT-carbon, and 5 parts of zinc white were uniformly mixed in two rolls to obtain a fluororubber composition. 170 ° C
After press vulcanizing for 10 minutes at 4 ° C in an oven at 200 ° C,
Secondary vulcanization was performed for a time. As a result of measuring physical properties according to JISK6301, hardness 70, 100% modulus 68 kg / c
It was m ² , the tensile strength was 190 kg / cm ² , and the elongation was 280%.

(Example 3) By the emulsion polymerization method, VdF /
TFE / perfluoromethyl vinyl ether / [Chemical formula 7]
= 75/6/18/1 (molar ratio), intrinsic viscosity [η] =
A copolymer of 0.49 was obtained (fluorine rubber-5). Similarly, a copolymer having VdF / TFE / perfluoromethyl vinyl ether / [Chemical formula 11] = 75/6/18/1 (molar ratio) and an intrinsic viscosity [η] = 0.42 was obtained (fluorine rubber-
6).

50 parts of fluororubber-3 and 5 parts of fluororubber-4
0 parts, 30 parts of MT-carbon, and 5 parts of magnesium oxide were uniformly mixed with 2 rolls to obtain a fluororubber composition. This was press-vulcanized at 170 ° C. for 10 minutes, and then secondary-vulcanized in an oven at 200 ° C. for 4 hours. As a result of measuring the physical properties according to JIS K6301, the hardness was 68, the 100% modulus was 50 kg / cm ² , the tensile strength was 150 kg / cm ² , and the elongation was 290%.

(Comparative Examples 1 to 3) In Examples 1 to 3,
A similar test was conducted using only one of the fluororubbers, but no vulcanized product was obtained.

[0032]

INDUSTRIAL APPLICABILITY The present invention provides a fluororubber composition which can be vulcanized without using a vulcanizing agent, and the industrial advantage of the present invention is extremely large. Further, the fluororubber of the present invention does not require a vulcanizing agent or a vulcanization accelerator as described above,
Not only is it suitable for medical tubes and catheters, food tubes, hoses, packing, etc., but also has excellent heat resistance, oil resistance, chemical resistance, etc. that fluororubbers have traditionally had. , Packing for O-rings, gaskets, hoses, sealing materials, diaphragms and valves in vehicles such as automobiles, ships, and aircraft, and similar parts in chemical plants, nuclear plants, and general industrial parts. Suitable for

Claims (2)

[Claims] 1. A fluorine-containing alkyl vinyl ether represented by (A) [Chemical formula 1] and a fluorine-containing elastic copolymer with at least one other ethylenically unsaturated monomer copolymerizable therewith, (B) ) A vulcanizable fluororubber composition comprising an epoxy group-containing vinyl ether represented by [Chemical formula 2] and an elastic copolymer with at least one other ethylenically unsaturated monomer copolymerizable therewith . [Chemical 1] [Chemical 2] 2. A vulcanizable fluororubber composition according to claim 1, wherein the ethylenically unsaturated monomer copolymerized in the components (A) and (B) is a fluorine-containing ethylenically unsaturated monomer. object.