JP2000344899A - Vulcanized adhesive between chloroprene rubber composition and metal - Google Patents

Abstract

(57) [Summary] [Problem] To provide a vulcanized adhesive having excellent vulcanization adhesion, low dynamic magnification and excellent vibration-proof properties. SOLUTION: A vulcanized adhesive of a chloroprene rubber composition containing a chloroprene rubber, an epoxy resin and a thiourea vulcanization accelerator with a metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vulcanized adhesive of a chloroprene rubber composition and a metal, and more particularly, to an anti-vibration property having excellent vulcanization adhesiveness and a small dynamic magnification. It is intended to provide a vulcanized adhesive body having both.

[0002]

2. Description of the Related Art Natural rubber having a relatively small dynamic magnification is considered to be most suitable as a rubber material used for a vibration isolating member, and is used as a vulcanized adhesive with metal. However, although natural rubber has excellent mechanical properties and vibration damping properties, it has a problem that its long-term durability such as ozone resistance and heat resistance is not sufficient. On the other hand, in the vibration damping member formed by vulcanization bonding with metal, the vulcanization adhesion between rubber and metal is also an important factor in addition to the performance of the rubber composition. For example, in order to improve the reliability of anti-vibration rubber for automobiles and the like, in addition to anti-vibration performance, a demand for a technique of firmly vulcanizing and bonding to metal has been increasing.

[0003]

SUMMARY OF THE INVENTION The present inventors have focused on chloroprene rubber, which is superior in durability, such as ozone resistance and heat resistance, to natural rubber, and has a vibration-proof adhesive formed by vulcanization bonding with metal. Attempted to apply to members. However, none of the conventionally known vulcanized adhesives of a chloroprene-based rubber composition and a metal simultaneously satisfy vibration damping performance and vulcanization adhesiveness, and other properties. A new vulcanized adhesive of a rubber composition and a metal has been required.

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and have achieved the object by combining a chloroprene-based rubber with an epoxy resin and a thiourea-based vulcanization accelerator. It was found that the present invention was possible, and the present invention was completed. That is, the present invention is a vulcanized adhesive having improved vulcanization adhesion to metal by using a rubber composition containing an epoxy resin and a thiourea vulcanization accelerator in a chloroprene rubber. Further, the present invention provides a method wherein the chloroprene rubber is one or two selected from xanthogen-modified chloroprene rubber, mercaptan-modified chloroprene rubber and sulfur-modified chloroprene rubber.
A vulcanized adhesive as described above, which is at least one kind. Furthermore, the present invention is a vibration damping member comprising a vulcanized adhesive of the above rubber composition and metal.

Hereinafter, the present invention will be described in more detail. The rubber component in the chloroprene-based rubber composition of the present invention contains chloroprene-based rubber as a main component. In addition to the chloroprene-based rubber, the rubber component contains natural rubber, butyl rubber, BR, NBR, EPDM, and the like as necessary. can do.

The chloroprene rubber used in the present invention is obtained by polymerizing a homopolymer of chloroprene or a mixture of chloroprene and one or more other copolymerizable monomers (hereinafter referred to as chloroprene monomer). The obtained copolymer (hereinafter often referred to as chloroprene rubber). Examples of monomers copolymerizable with chloroprene include 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, sulfur, styrene, acrylonitrile, methacrylonitrile, isoprene, butadiene and Examples thereof include acrylic acid, methacrylic acid, and esters thereof, and can be used in a range that satisfies the object of the present invention.

[0007] The polymerization method for obtaining the chloroprene rubber used in the present invention is not particularly limited, and a usual polymerization method can be used. The chloroprene monomer is prepared by subjecting the chloroprene monomer to a polymerization initiator generally used for the polymerization of chloroprene. It can be obtained by emulsion polymerization according to a commonly used method. The emulsifier used in the emulsion polymerization is not particularly limited, and is generally an emulsifier used for emulsion polymerization of chloroprene, for example, an alkali metal salt of a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, rosin acid or heterogeneous acid. Alkali metal salts of rosin acids
For example, an alkali metal salt of a formalin condensate of β-naphthalenesulfonic acid is used.

A chloroprene rubber is a polymer of a chloroprene monomer and is generally produced by emulsion polymerization, and is classified into a sulfur-modified type, a mercaptan-modified type and a xanthogen-modified type depending on the type of molecular weight regulator. In the sulfur-modified type, a polymer obtained by copolymerizing sulfur and a chloroprene-based monomer is plasticized with thiuram disulfide to adjust to a predetermined Mooney viscosity.
The mercaptan-modified type uses alkyl mercaptans such as n-dodecyl mercaptan, tert-dodecyl mercaptan and octyl mercaptan as a molecular weight regulator. In addition, xanthogen modified type,
An alkylxanthogen compound is used as a molecular weight regulator.

As the chloroprene rubber of the present invention, any of the above modified types can be used.
Mechanical properties such as tensile strength, low temperature resistance, scorch resistance,
The xanthogen-modified type is most preferable because it has good heat aging resistance, compression set, etc., and exhibits a low dynamic magnification.

Specific examples of the alkyl xanthogen compound used in the xanthogen modified type include dimethyl xanthogen disulfide, diethyl xanthogen disulfide, diisopropyl xanthogen disulfide, diisobutyl xanthogen disulfide and the like. The amount of the alkyl xanthogen compound used is selected so that the molecular weight of the chloroprene polymer or the Mooney viscosity of the chloroprene rubber obtained by isolating the polymer is appropriate. Although it depends on the structure of the alkyl group and the target molecular weight, it is generally 0.05 to 5.0 parts by weight, preferably 0.3 parts by weight, per 100 parts by weight of the chloroprene monomer.
It is used in the range of 1.0 to 1.0 parts by weight.

As the polymerization initiator, known organic peroxides generally used for emulsion polymerization of chloroprene such as potassium persulfate, ammonium persulfate, sodium persulfate, hydrogen peroxide and t-butyl hydroperoxide are used. .

In the present invention, the polymerization temperature and the final conversion of the monomer are not particularly limited.
° C, more preferably 20 to 50 ° C. Further, the conversion of the monomer is preferably performed so as to fall within the range of 60 to 90%. When the conversion reaches the conversion, the polymerization is stopped by adding a small amount of a polymerization inhibitor.
As the polymerization inhibitor, for example, thiodiphenylamine,
Commonly used inhibitors such as 4-tert-butylcatechol and 2,2-methylenebis-4-methyl-6-tert-butylphenol are used.

Unreacted monomers are removed, for example, by steam stripping, and then the p
After adjusting H, the polymer can be isolated by a conventional method such as freeze coagulation, washing with water, and drying with hot air.

The epoxy resin used in the present invention has an epoxy equivalent of about 100 to 6000. In addition, the type of epoxy resin is not limited, and in addition to a commercially available liquid epoxy resin or solid epoxy resin, a known epoxy resin such as a flexible epoxy resin or a special epoxy resin such as a heat-resistant epoxy resin is used. Although it can be used, a bisphenol A type epoxy resin (epoxy equivalent: 150 to 300), a general-purpose liquid epoxy resin, exhibits a sufficient effect.

The amount of the epoxy resin used in the present invention is preferably 0.1 to 15 parts by weight, more preferably 0.3 to 15 parts by weight, based on 100 parts by weight of the chloroprene rubber, in view of the balance between the vulcanization adhesion and the vibration damping performance. It is more preferably from 10 to 10 parts by weight, particularly preferably from 0.3 to 8 parts by weight. 0.
When the amount is less than 1 part by weight, the vulcanization adhesion to metal is not sufficiently improved, and when the amount is more than 15 parts by weight, the vibration-proofing performance is significantly reduced.

The vulcanizing agent used in the present invention is not particularly limited, but is preferably a metal oxide, specifically, zinc oxide,
Magnesium oxide, lead oxide, iron trioxide, titanium dioxide,
Calcium oxide and the like. These can be used in combination of two or more. In addition, vulcanization can be performed more effectively by using in combination with the following vulcanization accelerator. The amount of these vulcanizing agents added is chloroprene rubber 10
The amount is preferably 3 to 15 parts by weight with respect to 0 parts by weight.

Examples of the thiourea-based vulcanization accelerator include ethylene thiourea, diethyl thiourea, trimethyl thiourea, triethyl thiourea, N, N'-diphenyl thiourea, and particularly, trimeryl thiourea having processing safety and low compression set. Is preferred. The vulcanization accelerator may be used in combination with another vulcanization accelerator, for example, a guanidine-based, thiuram-based, or thiazole-based one, in order to adjust the vulcanization rate and processing safety. The addition amount of these vulcanization accelerators is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the chloroprene rubber.

Although the metal used in the present invention is not particularly limited, steel is generally most often used as the metal for the vibration isolating member, and can be used in the present invention. Other examples include stainless steel, zinc, copper, brass, aluminum, and the like, and further, alloys thereof. Further, these metals may be subjected to zinc plating, chrome plating, copper plating, brass plating, or the like according to the purpose.

In order to more strongly vulcanize and bond the metal and rubber used in the vibration isolating member, it is common practice to apply an adhesive treatment to the metal, but the present invention is also very effective. It is. As the adhesive for vulcanizing and adhering the chloroprene rubber composition of the present invention and the metal, Chemlock 205 (single coating) and Chemlock 220 manufactured by LOAD are used.
(Two-layer coating) or Toyo Chemical Laboratories Metalok GS, Metalok P, Metalok PA, Metalok GT, Firestone's Loxite 3040,
Ty Ply from Borg-Warner Corp
S, Daytonchemical Products
Lab's Thixon NM-2, Thixon
Combination system of P-4 and NM-2, or Thixon X
D-9263 in combination with NM-2, or Bayer
Desmodur R, Vulca from ICI
Bond TX or the like can be used, but it is necessary to appropriately select bond TX depending on the type of metal. For steel, a combined system of Chemlock 205 and 220 or 252X, or a combined system of Metalok PA-4 and Chemlock 220 is preferable.

The chloroprene-based rubber composition of the present invention can be blended with various additives conventionally used in chloroprene-based rubbers so as to reach target physical properties according to the intended use. Examples of the additive include a reinforcing agent, a softening agent, a processing aid, an antioxidant, and the like.

Examples of the reinforcing agent include carbon black, silica, and the like, which are used to increase the mechanical strength of rubber. The amount of the reinforcing agent is generally about 20 to 80 parts by weight based on 100 parts by weight of rubber. In addition, fillers such as calcium carbonate, clay, and talc can be added as needed.

Examples of the softener include petroleum softeners such as lubricating oil, process oil, paraffin, liquid paraffin, petrolatum, petroleum asphalt and the like, and fatty oil softeners such as rapeseed oil, linseed oil, castor oil and coconut oil. And rubber 10
Up to about 40 parts by weight can be added to 0 parts by weight.

Examples of the processing aid include fatty acids such as stearic acid, and can be added up to about 0.5 to 5 parts by weight based on 100 parts by weight of rubber.

Examples of the antioxidant include amines, imidazoles, metal salts of carbamic acid, phenols, waxes, etc., and 0.5 to 10 parts by weight of rubber.
About part by weight can be added.

Since the chloroprene rubber composition of the present invention has good processability, it is mixed with a kneader such as a kneader, a banbury or a roll in the same manner as in a normal chloroprene rubber, and the mixture is used in accordance with the purpose. The molded vulcanizate can be obtained by molding into a shape. Further, the epoxy resin is added at the initial and intermediate stages of the polymerization of chloroprene or after the polymerization is completed, and after the chloroprene-based rubber is contained in advance, the pH of the latex is adjusted, and freeze-coagulation, washing with water, and hot-air drying are performed in a conventional manner. It is also possible to use. Specifically, each component is kneaded at a temperature equal to or lower than the vulcanization temperature, and then the kneaded material is formed into various shapes and vulcanized and bonded to a metal to obtain a vulcanized adhesive. The temperature and vulcanization time during vulcanization can be set as appropriate. The vulcanization temperature is preferably from 130 to 200 ° C, more preferably from 140 to 190 ° C.

The vulcanized adhesive of the chloroprene-based rubber composition of the present invention and a metal can be used in addition to the mechanical properties of the rubber, as well as vibration-proofing properties, vulcanization adhesion to the metal, and durability such as heat resistance and ozone resistance. Can be used for a vibration-proof member. The anti-vibration member is not limited, but is particularly suitable for anti-vibration rubber for automobiles, which have more severe required performance.
Automotive anti-vibration rubbers include engine mounts, torsional dampers, rubber bushes, strut mounts, bound bumpers, helper rubbers, member mounts, stabilizer bushes, air springs, center support bearings, rubber-containing propeller shafts, anti-vibration levers, and panniers. Yon damper, damping rubber, idler arm bush, steering column bush, coupling rubber, body mount, muffler support, dynamic damper, piping rubber, and the like. In the railway field, it can be used for anti-vibration sleepers, anti-vibration hangers, bridge shoes, shoe seats, and the like. In addition, ships,
It can also be applied to anti-vibration members for aircraft, civil engineering, construction, and industrial machinery.

[0027]

EXAMPLES The present invention will be described in detail with reference to the following examples, but the present invention is not limited to the following examples. Examples 1 to 3 and Comparative Examples According to the formulation shown in Table 1, vulcanization adhesiveness was evaluated using a chloroprene rubber composition obtained by blending using an 8-inch roll, and physical properties of the vulcanized product were evaluated. The test was performed and the results are shown in Table 1. 160 ° C × 2 with hydraulic press
The mechanical properties such as tensile strength, elongation, and hardness of the test specimen vulcanized for 0 minutes were determined in accordance with JIS K6251. The dynamic magnification (E '/ 3Gs) determined from the storage elastic modulus (E') when a vibration having an amplitude of 0.1% was applied. 160 ° C x 30
The compression set test of the partially vulcanized sample is based on JIS
Performed according to K6262. For vulcanization bonding, a metal test piece was subjected to sandblasting in advance, and further, as an adhesive treatment after degreasing, undercoating Chemlock 205 twice with a brush and then overcoating Chemlock 220 twice to be subjected to an adhesion test. Vulcanization adhesion is 170 ° C × 20 with a hydraulic press
The evaluation of vulcanization adhesiveness was carried out based on a 90-degree peel test between a metal piece and rubber according to JIS K6256 (adhesion test method for vulcanized rubber). The metal piece is made of iron (JIS G
3141: SPCC-SD) was used.

[0028]

[Table 1]

The materials used in Table 1 are as follows. 1) Anti-aging agent octamine manufactured by Uniroyal 2) SRF grade carbon black 3) Petroleum-based process oil 4) Epicoat 828 (epoxy equivalent 184-194) manufactured by Yuka Shell Epoxy

[0030]

As shown in Table 1, the chloroprene rubber composition of the present invention has good adhesion to metal and a low dynamic magnification, and the vulcanized adhesive between the chloroprene rubber composition and metal is a vibration damping member. Useful as

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Claims (3)

[Claims] 1. A vulcanized adhesive of a chloroprene rubber composition and a metal, comprising a chloroprene rubber, an epoxy resin and a thiourea vulcanization accelerator. 2. The chloroprene rubber is selected from the group consisting of xanthogen-modified chloroprene rubber, mercaptan-modified chloroprene rubber, and sulfur-modified chloroprene rubber.
The vulcanized adhesive according to claim 1, wherein the adhesive is a kind or two or more kinds. 3. An anti-vibration member comprising a vulcanized adhesive of the rubber composition according to claim 1 and a metal.