JPH06331040A - Oil seal - Google Patents

Abstract

PURPOSE:To provide an oil seal for improving durability against lubricating oil while having an excellent mechanical characteristic, heat resistance, etc., by integrally forming a hardened object of specific fluorine-contained elastomer composition with metal or resin through a bonding agent. CONSTITUTION:This oil seal, copolymerized under existence of an iodine compound represented by a general formula R.Ix (where R is hydrocarbon of 1 to 3 carbon number, x is 1 or 2), is (A) component of fluorine-contained elastomer where Mooney viscosity ML1+10(121 deg.C) comprising a VdF unit containing 0.001 to 10wt.% iodine connected to a polymer molecular chain terminal end and at least one kind of other fluorine-contained monomer is 1 to 200 organic peroxide bridgeable. A hardening agent of fluorine-contained elastomer composition composed of this (A) component, (B) organic peroxide, (C) cobridge agent and (D) acid receiving agnet is integrally bonded with metal or resin through a bonding agent hardened by bridging.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel oil seal using a fluorine-containing elastomer. More specifically, the present invention is as excellent as an oil seal using a conventionally known fluorine-containing elastomer. Mechanical properties,
While having heat resistance, the cured product of the fluorine-containing elastomer composition and the metal or resin are firmly bonded and integrated via an adhesive that cures by crosslinking, and can be used as a lubricating oil such as gear oil or engine oil. On the other hand, the present invention relates to an oil seal having excellent durability.

[0002]

Fluorine-containing elastomers generally have heat resistance,
Since it has excellent oil resistance, it is used in various industrial fields, such as general machinery industry, pollution-related departments, automobiles, ships, aircraft, hydraulic equipment, and the like. Elastomers are superior in chemical resistance to fluoroelastomers cross-linked by other methods, so lubricating oils containing many additives such as detergent dispersants, extreme pressure reducing agents, rust inhibitors, and antioxidants. For O-rings, gaskets, diaphragms,
Used as valves, hoses, rolls, and sheet materials.

However, a fluorine-containing elastomer that is crosslinked with an organic peroxide is difficult to firmly bond and integrate with a metal or a resin because a halogen compound derived from the crosslinking point is generated during molding and crosslinking to deteriorate the adhesive. However, there is a problem in oil seals and the like that the cured product of the fluorine-containing elastomer composition is separated from the metal ring during use.

On the other hand, a cured product of a fluorine-containing elastomer composition cross-linked with an aromatic polyol compound such as bisphenol AF can obtain an oil seal firmly adhered and integrated with a metal or a resin. , Durability against engine oil and gear oil containing a lot of additives such as extreme pressure reducing agent, rust preventive, and antioxidant is significantly inferior to the cured product of the fluorine-containing elastomer composition cross-linked with organic peroxide. .

[0005]

The object of the present invention is to provide the same excellent mechanical properties and heat resistance as those of oil seals using conventionally known fluorine-containing elastomer compositions,
The cured product of the fluorinated elastomer composition and the metal or resin are firmly bonded and integrated via an adhesive that is cured by crosslinking, and have excellent durability against lubricating oil such as gear oil and engine oil. It is to provide the oil seal which has.

[0006]

Means for Solving the Problems As a result of intensive studies by the present inventors, as a result of copolymerization in the presence of a specific iodine compound,
Organic peroxide crosslinkable fluorine-containing elastomer composition containing vinylidene fluoride units (hereinafter referred to as “VdF units”) containing iodine bonded to the polymer molecular chain end and at least one other fluorine-containing monomer It was found that an oil seal in which a cured product of (1) and a metal or a resin are adhesively integrated through an adhesive that cures by cross-linking is suitable for the above purpose, and the present invention has been completed based on this finding. It was

That is, the present invention provides (A) the general formula R.
0.001-10 copolymerized in the presence of an iodine compound represented by Ix (wherein R is a hydrocarbon having 1 to 3 carbon atoms, x is 1 or 2) and bonded to the polymer chain end Mooney viscosity ML consisting of VdF units and at least one other fluorine-containing monomer containing wt% iodine
_{1 + 10} (121 ° C) 1 to 200 organic peroxide crosslinkable fluorine-containing elastomer, (B) organic peroxide, (C)
A cured product of a fluorine-containing elastomer composition consisting essentially of a co-crosslinking agent and (D) an acid acceptor and a metal or resin are firmly bonded and integrated via an adhesive that cures by crosslinking, and a gear oil or It is intended to provide an oil seal having excellent durability against lubricating oil such as engine oil.

In order to crosslink the fluorine-containing elastomer with an organic peroxide, iodine or bromine is usually introduced as a crosslinking point. In order to use iodine as a cross-linking point, a method in which copolymerization is performed in the presence of an iodine compound and iodine is bonded to the terminal of the polymer molecule chain is adopted. In this case, the iodine compound is represented by the general formula Rf.Ix (wherein Rf is a saturated or unsaturated fluorohydrocarbon group or a chlorofluorohydrocarbon group, and x is described in Japanese Patent Publication No. 63-41928). (The number of Rf bonds, an integer of 1 or more)
An iodine compound represented by is used.

In order to use bromine as a cross-linking point, a method of copolymerizing a brominated olefin compound such as bromotrifluoroethylene or 4-bromo-3,3,4,4-tetrafluorobutene-1 (Japanese Patent Publication No. 53-53). No. 4115) is used, but there is a problem that compression set is inferior according to this method, and copolymerization is performed in the presence of an iodine compound, and iodine is bonded to the polymer molecular chain terminal to form a crosslinking point. Is more desirable.

Vd copolymerized in the presence of iodine compounds
In the fluorine-containing elastomer composed of the F unit and at least one other fluorine-containing monomer, most of the polymer molecular chain terminal structures are CF ₂ I or CH ₂ I. It is generally known that a polymer having a hydrocarbon group is more easily wetted by an adhesive than a polymer having a fluorohydrocarbon group, and the structure of the polymer molecular chain end has a great influence on the adhesiveness. A fluorine-containing elastomer copolymerized in the presence of R · Ix, which is an iodine compound having a hydrocarbon group, is a fluorine-containing elastomer copolymerized in the presence of Rf · Ix, which is an iodine compound having a fluorohydrocarbon group or a chlorofluorohydrocarbon group. There is a higher probability that the polymer molecular chain end will be CH ₂ I than the elastomer. Therefore, the cured product of the fluoroelastomer composition of the present application has a higher affinity with the adhesive than the cured product of the composition of the fluoroelastomer copolymerized in the presence of Rf. Estimated to be obtained.

The fluorine-containing elastomer composition of the present invention will be described below.

The component (A) is copolymerized in the presence of an iodine compound represented by the general formula R.Ix (wherein R is a hydrocarbon having 1 to 3 carbon atoms and x is 1 or 2). , Mooney viscosity ML _{1 + 10} (121 ° C.) consisting of VdF units containing 0.001 to 10% by weight of iodine bound to the polymer chain ends and at least one other fluorine-containing monomer
Is a fluorine-containing elastomer capable of crosslinking with an organic peroxide of 1 to 200.

Specifically, (a) VdF unit and (b) hexafluoropropene unit (hereinafter referred to as HFP unit)
And optionally (c) a fluorine-containing elastomer composed of a tetrafluoroethylene unit (hereinafter referred to as TFE unit), a VdF unit, a perfluoroalkyl perfluorovinyl ether unit and a TFE unit, and 0.001 bonded to the polymer molecular chain end. Fluorine-containing elastomers containing 10 to 10% by weight of iodine are preferable. More preferable component (A) is (a) VdF unit and (b) HF.
Optionally from 0 to 35% by weight of (c) T based on the total weight of P units and monomer units (a), (b) and (c).
Consists of FE units, and (a) VdF units and (b) HF
The weight ratio of P units is 40:60 to 80:20,
0.001 to 10% by weight bonded to the polymer chain end
Is a fluorine-containing elastomer containing iodine.
Particularly preferred component (A) is (a) VdF unit and (b)
HFP unit and monomer unit (a), (b) and (c)
Optionally from 0 to 35% by weight, based on the total weight of (c) TFE units, and (a) VdF units to (b) HFP units in a weight ratio of 40:60 to 80: 2.
0, and (a) VdF unit is 40 to 70% by weight.
And 0.001-bonded to the end of the polymer molecular chain
A fluorine-containing elastomer containing 10% by weight of iodine.

The preferable content of iodine bound to the polymer molecular chain end is in the range of 0.001 to 10% by weight, because when it is less than 0.001% by weight, sufficient crosslinking density cannot be obtained and compression set resistance is high. This is because the crosslink density is too high and the elastomer loses elasticity when it exceeds 10% by weight. A particularly preferred range of iodine content is 0.05 to 3% by weight.

As a method for introducing iodine, which can serve as a crosslinking point, to the end of the polymer molecular chain, a chain transfer agent is represented by the general formula R.Ix (wherein R is a hydrocarbon having 1 to 3 carbon atoms, x
It is essential to use an iodine compound represented by 1) or 2), and it is shown in JP-A-60-221409, JP-A-3-247608, and JP-B-5-405. , Batch emulsion polymerization, continuous emulsion polymerization,
A polymerization method such as suspension polymerization or solution polymerization is adopted. Examples of the iodine compound of the present invention include monoiodomethane, diiodomethane, 1-iodoethane, 1,2-diiodoethane, 1-iodo-n-propane, isopropyl iodide,
1,3-diiodo-n-propane and the like are preferable, and diiodomethane is particularly preferable.

Further, the component (A) is bromotrifluoroethylene or 4-bromo-3,3,4,4-tetrafluorobutene-providing 0.1 to 1.0% by weight of bromine which can serve as a crosslinking point. It may contain a bromine-containing crosslinking point monomer unit such as 1,1,1-difluoro-2-bromethylene or brominated fluorovinyl ether.

Mooney viscosity ML _{1 + 10} (12) of component (A)
1 ° C.) is in the range of 1 to 200. If it is less than 1, a sufficient crosslinking density cannot be obtained, and if it exceeds 200, it is an open type kneading roll or a closed type kneading roll (Banbury mixer, pressure kneader, etc.). This makes it difficult to knead. A particularly preferable range of Mooney viscosity ML _{1 + 10} (121 ° C.) is 5 to 120.

As the organic peroxide as the component (B), an organic peroxide which generates a peroxide radical under a crosslinking condition is used. For example, 1,1-bis (tert-butylperoxy) -3,5 , 5-Trimethylcyclohexane, 1,1
-Bis (tert-butylperoxy) cyclohexane,
2,2-bis (tert-butylperoxy) octane, n
-Butyl 4,4-bis (tert-butylperoxy) valerate, 2,2-bis (tert-butylperoxy) butane, 2,5-dimethylhexane-2,5-dihydroxyperoxide, di-tert-butyl Peroxide, tert-
Butyl cumyl peroxide, dicumyl peroxide,
α, α'-bis (tert-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di (te
rt-Butylperoxy) hexane, 2,5-dimethyl-
2,5-di (tert-butylperoxy) hexyne-3,
Examples thereof include benzoyl peroxide, tert-butylperoxybenzene, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, tert-butylperoxymaleic acid, and tert-butyl-oxyisopropyl carbonate. The preferred organic peroxide is 2,5-
Dimethyl-2,5-di (tert-butylperoxy) hexane, dicumyl peroxide, α, α'-bis (tert-
Butyl peroxy-m-isopropyl) benzene.

The mixing ratio of the component (B) is usually preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the component (A). The component (B) is in this range because if it is less than 0.05, a sufficient crosslinking rate cannot be obtained and the mold releasability is deteriorated, and if it exceeds 5 parts by weight, the compression set resistance is significantly deteriorated. Is. The particularly preferred range of component (B) is 0.1-3.
Parts by weight.

The component (C) is a co-crosslinking agent composed of a polyunsaturated compound which is used in combination with an organic peroxide to enhance the physical properties of the crosslinked product. The component (C) is, for example, triallyl cyanurate, trimetallyl isocyanurate, triallyl isocyanurate, triacrylic formal, triallyl trimellitate, N, N′-m-phenylene bismaleimide, diallyl phthalate, tetraallyl terephthalate. Examples thereof include taramide, tris (diallylamine) -s-triazine, triallyl phosphite, N, N-diallyl acrylamide and the like, and a particularly preferable co-crosslinking agent is triallyl isocyanurate. The compounding ratio of the component (C) is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the component (A). When the amount of the component (C) is within this range, sufficient crosslinking density cannot be obtained when the amount is less than 0.1 parts by weight, and when the amount exceeds 10 parts by weight, the component (C) bleeds to the surface of the elastomer during molding, causing defective molding. This is because The particularly preferable range of the component (C) is 0.2 to 6 parts by weight.

The acid acceptor as the component (D) is, for example, a metal oxide, a metal hydroxide or a hydrotalcite compound, and specifically, magnesium oxide, calcium oxide,
Zinc oxide, lead oxide, magnesium hydroxide, calcium hydroxide, [Mg ₄ Al ₂ (OH) ₁₂ ] ²⁺ CO ₃ ²⁻ , Mg ₄
Al ₂ O _{7 and the} like are preferable, and magnesium oxide, [Mg
₄ Al ₂ (OH) ₁₂ ] ²⁺ CO ₃ ²⁻ is particularly preferred.

The proportion of the component (D) is usually 0.5 to 40 parts by weight per 100 parts by weight of the component (A). The component (D) is in this range because if it is less than 0.5 parts by weight, sufficient crosslink adhesion stability cannot be obtained, and if it exceeds 40 parts by weight, compression set resistance is significantly deteriorated. The particularly preferable range of the component (D) is 1 to 20 parts by weight.

In the fluorine-containing elastomer composition of the present invention, if necessary, other components such as carbon black, austin black, graphite, silica, clay, diatomaceous earth, talc, wollastonite,
Calcium carbonate, calcium silicate, calcium fluoride,
Barium sulfate, sulfone compound, phosphate ester, fatty amine, higher fatty acid ester, fatty acid calcium, fatty acid amide, low molecular weight polyethylene, silicone oil,
Fillers such as silicone grease, stearic acid, calcium stearate, magnesium stearate, aluminum stearate, zinc stearate, sodium stearate, titanium white, red iron oxide, etc., processing aids, plasticizers, colorants, etc. can be added. .

Further, conventionally known cross-linking agents and cross-linking accelerators may be added within the range not departing from the gist of the present invention.

The metal that adheres to the cured product of the fluorine-containing elastomer composition of the present invention is preferably stainless steel, iron, brass, aluminum or the like, and the resin that adheres to the cured product of the fluorine-containing elastomer composition is nylon, polysulfone, or polyacetal. , Polybutylene terephthalate, polyimide, polyether ketone, polyethylene terephthalate, polycarbonate, polyphenylene oxide, polyphenylene sulfide, fluororesin and the like are preferable.

As the adhesive which is hardened by the crosslinking of the present invention, a silane coupling agent type, an epoxy type or a phenol resin type, which is durable in the environment where the fluorine-containing elastomer is used, is used. Far East
Incorporated product "Chemlock Y-431
0 "," Chemlock 607 "," Chemlock Y-532 "
3 ", Yokohama Polymer Research Laboratory product" Monicas CF-5M ",
"Monicas QZR-48", "Monicas V-16A /
B "," Monicas M-16A / B ", SIKSON product" AN-187 ", Toyo Chemical Research Laboratory product" Metalloc S "
-2 "," Metalock S-7 "," Metalock S-10 "
A "and so on. Moreover, you may dilute the said adhesive agent with an organic solvent as needed.

The method for molding the oil seal of the present invention is carried out, for example, by kneading the fluorine-containing elastomer composition with an open-type kneading roll or a closed-type kneading roll (Banbury mixer, pressure kneader, etc.), then compression-molding and injecting the kneading composition. It is put into a mold by a method such as molding or injection molding, and together with a ring of metal or resin coated with an adhesive that is cured by crosslinking, pressure is applied to perform primary crosslinking to simultaneously cure the kneading composition and the adhesive, and then necessary. The method of secondary cross-linking and the like may be used depending on The conditions for the primary crosslinking include a temperature of 120 to 2
00 ° C, time 1 to 180 minutes, pressure 20 to 150 kg / m
² ranges, as the conditions for the secondary crosslinking, a temperature from 120 to 2
The range of 50 ° C. and the time of 0 to 48 hours is preferable.

The oil seal of the present invention has the same excellent tensile properties and heat resistance as the oil seal obtained from the conventionally known fluorine-containing elastomer composition, but is cross-linked with an organic peroxide. The cured product of the composition and the metal or resin are firmly bonded and integrated via an adhesive that cures by crosslinking, and therefore, according to the above-described method for molding the oil seal of the present invention, molding As a result, defective adhesion at the time is significantly reduced.
In addition, the problem that the cured product of the fluorine-containing elastomer composition and the metal ring peel off during use of the oil seal is reduced.

[0029]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The Mooney viscosity of the fluoroelastomer, the physical properties of the cured product of the fluoroelastomer composition and the crosslinking adhesion test were determined by the following methods. (1) Mooney viscosity is L according to JIS-K6300.
Using a mold rotor, the temperature was 121 ° C., the preheating time was 1 minute, and the rotor operation time was 10 minutes. (2) The hardness [JIS-A], 100% tensile stress, tensile strength, and elongation of the crosslinked product were measured according to JIS-K6301. (3) The rubber surface hardness was measured with a micro hardness meter manufactured by Wallace. (4) The adhesion test was performed by the following method.

1. Width 15 mm, length 50 mm, thickness 1 m
m SUS304 metal test piece half face polishing cloth # 240
Polish with.

2. The polished surface of the metal test piece is degreased with methyl ethyl ketone and placed in a dryer at a temperature of 120 ° C. for 10 minutes to dry.

3. Apply a vulcanizing adhesive to the polished surface of the metal test piece with a brush.

4. Put in a dryer at a temperature of 120 ° C. and bake for 15 minutes.

5. Four metal test pieces are laid on the preheated mold, the fluorine-containing elastomer composition is placed, and compression molding and crosslinking are performed.

6. The adhesion test piece is taken out of the mold and the secondary cross-linking is performed in the air circulation type furnace.

7. Make a notch in the rubber part with a cutter knife and peel the rubber from the metal test piece with nose pliers.

8. The area where the rubber remains on the metal test piece after breaking at the rubber portion is defined as the rubber residual rate. When the rubber is completely adhered to the metal piece, the rubber residual rate is 100%.

Reference Example 1 An autoclave having an internal volume of about 15 liters equipped with an electromagnetic induction stirrer was sufficiently scavenged with nitrogen gas, and depressurization-filling with nitrogen was repeated 3 times to replace nitrogen, and then deoxygenated under reduced pressure. 5.7 kg of purified water, 5.7 g of methyl cellulose (viscosity 50 cp) as a suspension stabilizer,
80.0 g of 1,1,2-trichloro-1,2,2-trifluoroethane (hereinafter referred to as R-113) and 10.3 g of diiodomethane were charged, and the temperature was maintained at 50 ° C while stirring at 600 rpm. Then, using a mixed monomer consisting of 30 mol% of VdF unit, 63 mol% of HFP unit and 7 mol% of TFE unit as a charging gas, 20 kg / cm ²
・ Prepared until G.

Next, an R-113 solution 1 containing 15% by weight of diisopropyl peroxydicarbonate as a catalyst.
0.5 g was charged and the polymerization was started. When the pressure is reduced to 19.5 kg / cm ² · G by polymerization, VdF unit 64 mol%, HFP unit 18 mol% and TFE unit 18
By adding a mixed monomer consisting of mol% as an additional gas,
The pressure was returned to 20 kg / cm ² · G again. Such an operation was repeated to carry out the polymerization reaction for 25 hours. After the completion of the polymerization reaction, the remaining mixed monomer was scavenged, the obtained suspension was dehydrated with a centrifuge, thoroughly washed with water, and then vacuum dried at 100 ° C. to obtain about 3.2 kg of a fluoroelastomer.
When the obtained fluorine-containing elastomer was analyzed by ¹⁹ F-NMR, it was found that the VdF unit was 47.7% by weight, the HFP unit was 31.0% by weight, and the TFE unit was 21.0% by weight. The fluorine-containing elastomer contained 0.3% by weight of iodine and had a Mooney viscosity ML _{1 + 10} (121 ° C.) of 35.

Reference Example 2 A charging gas was a mixed monomer consisting of 11 mol% of VdF unit, 82 mol% of HFP unit and 7 mol% of TFE unit, and additional gas was 55 mol% of VdF unit, 24 mol% of HFP unit and TFE unit 21 mol%
Was carried out in the same manner as in Reference Example 1 except that the polymerization reaction was carried out for 30 hours, to obtain about 2.4 kg of a fluorine-containing elastomer. The obtained fluoroelastomer
^When analyzed by ¹⁹ F-NMR, VdF units of 38.
0% by weight, HFP unit 40.0% by weight and TFE unit 2
It was 1.6% by weight. The fluorine-containing elastomer contains 0.4% by weight of iodine and has a Mooney viscosity ML.
_{1 + 10} (121 ° C) was 30.

Reference Example 3 Instead of diiodomethane,
A polymerization reaction was carried out for 29 hours in the same manner as in Reference Example 2 except that 17.4 g of 1,4-diiodoperfluorobutane was used to obtain about 2.2 kg of a fluorine-containing elastomer. When the obtained fluorine-containing elastomer was analyzed by ¹⁹ F-NMR, VdF unit was 38.0% by weight and HFP unit was 4
0.0% by weight and 21.6% by weight of TFE unit.
Further, the fluorine-containing elastomer contains 0.4% by weight of iodine.
The Mooney viscosity ML _{1 + 10} (121 ° C) is 25
Met.

(Example 1) 100 parts by weight of the fluorine-containing elastomer of Reference Example 1 was wound on an open type kneading roll, and CAN was used.
CARB product MT carbon black "Thermax N
20 parts by weight of "990" and 6 parts by weight of high activity magnesium oxide "Kyowamag 150" manufactured by Kyowa Chemical Industry Co., Ltd. are kneaded. Next, Nippon Kasei Co., Ltd. product triallyl isocyanurate “TAIC” 4 parts by weight, NOF Corporation product 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane “Perhexa 25B-40 (organic The peroxide content was 40% by weight) ", 3.75 parts by weight were kneaded, and the mixture was allowed to stand overnight for aging.

Then, after kneading again, put in a mold,
Press-crosslinking was performed at a temperature of 160 ° C. for 10 minutes to form a sheet and a sample for adhesion test. Then, it was taken out from the mold and heated in an air circulation type furnace at a temperature of 180 ° C. for 4 hours to complete the secondary crosslinking, and various tests were conducted. The adhesive used in the vulcanization adhesion test is "Monicas CF-5M", a product of Yokohama Polymer Research Institute.
It was used. The crosslinked physical properties and the crosslink adhesion test of the crosslinked molded product thus obtained are shown in Table 1.

Example 2 Various tests were conducted in the same manner as in Example 1 except that the fluoroelastomer of Reference Example 2 was used instead of the fluoroelastomer of Example 1.
The results are shown in Table 1.

Comparative Example 1 Various tests were carried out in the same manner as in Example 1 except that the fluorine-containing elastomer of Reference Example 3 was used instead of the fluorine-containing elastomer of Example 1.
The results are shown in Table 1.

[0047]

[Table 1] While Examples 1 and 2 are almost completely bonded,
In Comparative Example 1, there is a part that is not adhered, and if there is a part that is not adhered, lubricating oil, solvent, etc. will penetrate and cause peeling.

(Example 3) A test piece having a width of 20 mm, a length of 50 mm and a thickness of 2 mm was made from the sheet prepared in Example 1 and manufactured by Nippon Oil Co., Ltd.
TRA90 "as a test oil, temperature 150 ℃, 1000
When the rubber surface hardness was examined after conducting the lubricating oil resistance test under the conditions of time, it was ± 0.

(Example 4) Using the sheet prepared in Example 2, the same test as in Example 3 was carried out. As a result, the rubber surface hardness was lowered by 1.2 points.

(Comparative Example 2) 48 wt% VdF unit, 3
Bisphenol AF2 was prepared by winding 100 parts by weight of an iodine-free fluoroelastomer having a Mooney viscosity of ML _{1 + 10} (121 ° C.) of 60, which is composed of 1% by weight of HFP unit and 21% by weight of TFE unit, into an open type kneading roll. Parts by weight, 0.38 parts by weight of bis (benzyldiphenylphosphine) iminium chloride, and then 20 parts by weight of MT carbon black "Thermax N-990", 6 parts by weight of calcium hydroxide, high activity magnesium oxide "Kyowamag" 150 parts of 3 parts by weight was kneaded and left as it was overnight for aging.

Then, after kneading again, it is put in a mold,
Press crosslinking was carried out at a temperature of 170 ° C. for 20 minutes to form a sheet. Then, it was taken out of the mold and heated in an air circulation type furnace at a temperature of 232 ° C. for 24 hours to complete the secondary vulcanization, and the same test as in Example 3 was carried out. The rubber surface hardness was 4.
It increased by 9 points.

Even when immersed in gear oil for a long period of time, the cured product of the composition of the present invention does not show the phenomenon that the surface is cured. On the other hand, the cured product of the fluorine-containing elastomer composition vulcanized with the aromatic polyol compound has a significantly increased surface hardness, and it is clear that surface cracks are likely to occur during use of the oil seal, and this crack is It may cause oil leakage.

(Embodiment 5) In the same manner as in Embodiment 1, JI
An oil seal with a peripheral rubber dust guard having a nominal inner diameter of 48 mm, an outer diameter of 70 mm, and a width of 12 mm described in S-B2402 was molded. In addition, iron was used as the metal ring, and "Monicas V-16A / B" and "Monicas M-16A / B" manufactured by Yokohama Polymer Research Institute were used as the adhesive.

The molded oil seal is heated to a temperature of 200.degree.
Rubber residual ratio and rubber surface condition after hot air heating aging test under the condition of 68 hours, and a temperature of 1 at a test oil of "Gear oil EP80" manufactured by Nippon Oil Co., Ltd.
The rubber residual ratio and the rubber surface state after conducting the lubricating oil resistance test under the conditions of 50 ° C. and 168 hours were examined. The results are shown in Table 2. The oil seal of Example 5 has extremely excellent heat resistance and lubricating oil resistance.

[0055]

[Table 2]

[0056]

The oil seal of the present invention has the same excellent mechanical properties and heat resistance as the oil seal using the conventionally known organic peroxide-crosslinkable fluorine-containing elastomer composition, but it does not contain fluorine. The cured product of the elastomer composition and the metal or resin are firmly bonded and integrated via an adhesive that cures by crosslinking, and have excellent durability against lubricating oil such as gear oil and engine oil. Therefore, the reliability of the oil seal is greatly improved and the industrial value is extremely high.

Claims (1)

[Claims] 1. A copolymerization in the presence of an iodine compound represented by the general formula (A) R.Ix (wherein R is a hydrocarbon having 1 to 3 carbon atoms and x is 1 or 2), Mooney viscosity ML _{1 + 10} (12) consisting of vinylidene fluoride units and at least one other fluorine-containing monomer containing 0.001 to 10% by weight of iodine bound to the polymer chain end.
Fluorine-containing elastomer capable of crosslinking with an organic peroxide having a temperature of 1 ° C.) of 1 to 200, (B) an organic peroxide, (C) a co-crosslinking agent,
(D) An oil seal in which a cured product of a fluorine-containing elastomer composition consisting essentially of an acid acceptor and a metal or a resin are bonded and integrated via an adhesive that is cured by crosslinking.