JP2001011201A - Vulcanized adhesive of chloroprene copolymer and metal - Google Patents

Abstract

(57) [Problem] To provide a new rubber composition and a vulcanized bonded body of a metal, which simultaneously satisfy vibration-proof performance, vulcanized adhesion to a metal, and other properties. SOLUTION: A 2-chloro-1,3-butadiene monomer, a monomer having a carboxyl group, a monomer having a cyano group, a monomer having an epoxy group, and a monomer having a hydroxyl group A vulcanized adhesive of a rubber composition mainly composed of one or two or more copolymers and 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. An anti-vibration rubber using chloroprene rubber is known in JP-A-3-76734, but there is no description about a vulcanized adhesive with a metal.

[0003]

SUMMARY OF THE INVENTION The present inventors have focused on chloroprene rubber, which has better durability such as ozone resistance and heat resistance than natural rubber, and has a vibration damping member formed by vulcanization bonding with metal. Tried to apply to. However, none of the conventionally known vulcanized adhesives of a chloroprene rubber composition and a metal satisfy the vibration-damping performance, the vulcanized adhesiveness, and other characteristics at the same time. Thus, a vulcanized adhesive of a rubber composition and a metal was required.

[0004]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and found that 2-chloro-
The problem is solved by using a copolymer obtained by copolymerizing a 1,3-butadiene monomer (hereinafter, referred to as a chloroprene monomer) and a monomer having a specific functional group in a molecule. The inventors have found that the present invention can be solved, and have completed the present invention. That is, the present invention relates to a copolymer obtained by copolymerizing a 2-chloro-1,3-butadiene monomer and one or more of the following monomers (a) to (d). It is a vulcanized adhesive of a rubber composition mainly composed of a coalesced material and a metal, and is a vibration-proof member made of the vulcanized adhesive. (A) a monomer having a carboxyl group in the molecule (b) a monomer having a cyano group in the molecule (c) a monomer having an epoxy group in the molecule (d) a monomer having a hydroxyl group in the molecule Monomer

Hereinafter, the present invention will be described in more detail. The chloroprene copolymer used in the present invention is obtained by copolymerizing a chloroprene monomer with one or two or more monomers having a specific functional group in a molecule shown in the following (a) to (d). It is a copolymer obtained by the above. (A)
Is a monomer having a carboxyl group in the molecule represented by the following general formula (1).

[0006]

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Wherein R _{1 and} R ₂ are hydrogen or a C ₁ -C ₁₀ alkyl group, and X is —COOH or hydrogen or C ₁ -C
₁₀ alkyl groups, such as methacrylic acid, acrylic acid, and maleic acid. (B) is a monomer having a cyano group in a molecule represented by the following general formula (2).

[0008]

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In the formula, R _{1 to} R ₃ are hydrogen or a C _{1 to} C ₁₀ alkyl group, such as acrylonitrile and methacrylonitrile. (C) is a monomer having an epoxy group in a molecule represented by the following general formula (3).

[0010]

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In the formula, R _{1 to} R ₃ are hydrogen or a C _{1 to} C ₁₀ alkyl group, and R ₄ is a group represented by the following general formula (4).

[0012]

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(Where n is an integer of 1 or more) Examples of the monomer (c) include glycidyl methacrylate and glycidyl acrylate. (D)
Is a monomer represented by the following general formula (5) and having a hydroxyl group in the molecule.

[0014]

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In the formula, R _{1 to} R ₃ are hydrogen or a C _{1 to} C ₁₀ alkyl group, and R ₄ is —C _n H _2n OH (where n is an integer of 1 or more). Examples include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and the like.

In synthesizing the chloroprene copolymer of the present invention, another monomer copolymerizable with the chloroprene monomer may be copolymerized. There are 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, sulfur, styrene, isoprene, butadiene, and the like, which can be used as long as the characteristics of the present invention are not impaired. Further, a small amount of another kind of rubber such as natural rubber, butyl rubber, BR, NBR, EPDM, etc. may be blended with the chloroprene copolymer within a range not to impair the properties of the present invention.

When the chloroprene copolymer used in the present invention is produced, the total amount of one or more monomers selected from (a) to (d) is 0% per monomer. 0.1 to 50 mol%, preferably 0.5 to 30 mol%. If the amount deviates from this range, the effect of the present invention is not significantly exhibited. If the amount is outside this range, the amount of unreacted monomer remaining in the reaction system at the end of the polymerization increases, which makes the demonomer operation complicated and economically disadvantageous. Good physical properties are impaired.

In order to obtain the chloroprene copolymer used in the present invention, emulsion polymerization may be performed under a predetermined pH condition according to a known technique. Hereinafter, the emulsion polymerization will be described.
When the monomer (a) is copolymerized with a chloroprene monomer, an alkali metal salt of an alkylbenzenesulfonic acid having 6 to 18 carbon atoms or an alkali metal of a formalin condensate of β-naphthalenesulfonic acid is used in an acidic atmosphere. One or more emulsifiers selected from metal salts, polyoxyethylene alkyl ethers and the like are used. (B) ~
In the case of (d), in an acidic to alkaline atmosphere, in addition to the above emulsifier, an emulsifier containing an alkali metal salt of rosin acid or disproportionated rosin acid can be appropriately selected and used.

The molecular weight regulator is not particularly limited, and alkyl mercaptan, dialkyl xanthogen disulfide and the like are used. As the initiator, for example, benzoyl peroxide, potassium persulfate and the like are used. The polymerization temperature is 0
It is in the range of 60C, preferably 10-50C. The monomer conversion ranges from 40 to 90%, preferably from 60 to 90%. As the polymerization terminator, a commonly used terminator can be used. For example, thiodiphenylamine, 4-tert-butylcatechol, diethylhydroxylamine and the like can be used.

Unreacted monomers are removed by, for example, a steam stripping method.
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 chloroprene copolymer obtained in the present invention (hereinafter often referred to as chloroprene rubber)
Can be made into a chloroprene rubber by compounding, kneading and vulcanizing a vulcanizing agent, a vulcanization accelerator, a reinforcing agent, a softener, a plasticizer, a processing aid, an antioxidant, and the like. Incorporation of an epoxy resin having an epoxy group in the molecule is effective as a means for more clearly expressing the effects of the present invention.

As the epoxy resin, for example, a commercially available liquid or solid epoxy resin having an epoxy equivalent of about 100 to 6000, or a special epoxy resin such as a flexible epoxy resin, a heat-resistant epoxy resin, or a brominated epoxy resin. Known ones can be used. In addition to adding the epoxy resin to the chloroprene-based rubber, the epoxy resin can be added during the synthesis of the chloroprene-based copolymer, that is, at the initial stage and the middle stage of the polymerization, or after the completion of the polymerization and before the finishing with drying. In this case, a method of adding an emulsion obtained by emulsifying an epoxy resin in advance is preferably used.

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 may be used in combination of two or more. Further, the vulcanization can be more effectively performed by using in combination with a vulcanization accelerator described later.
The added amount of these vulcanizing agents is preferably 3 to 15 parts by weight based on 100 parts by weight of the chloroprene rubber.

As the vulcanization accelerator, for example, ethylenethiourea, diethylthiourea, trimethylthiourea, triethylthiourea, N, N'-diphenylthiourea and the like are used. Particularly, from the viewpoint of processing safety and low compression set, trimethylthiourea is preferably used. Further, for the purpose of adjusting the vulcanization rate and processing safety, other vulcanization accelerators, for example, guanidine, thiuram, thiazole and the like may be used in combination. 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.

Examples of the reinforcing agent include carbon black and silica, and are used to increase the mechanical strength of rubber. Generally, 20 to 100 parts by weight of rubber
It is about 80 parts by weight. 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 in an amount of 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 and the like.
About part by weight can be added.

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, but it 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 for the vibration isolating member, it is common practice to apply an adhesive treatment to the metal, but the present invention is also extremely effective. It is. Examples of the adhesive for vulcanizing and bonding the rubber composition containing the chloroprene copolymer of the present invention as a main component and a metal include a combination of Chemlock 205 (single coating) and Chemlock 220 (two-layer coating) manufactured by LOAD or Toyo. Metalok GS, Metalok P, Metalok PA, Metalok GT, Loxite 3040 from Firestone, Borg-Warner Co.
tyPlyS, Dayton Chemical
Thixon N from al Products Lab
M-2, a combined system of Thixon P-4 and NM-2, or a combined system of Thixon XD-9263 and NM-2, or Desmodur R, I manufactured by Bayer
Vulcabon TX or the like manufactured by CI Inc. can be used, but it is necessary to select appropriately 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 rubber composition containing the chloroprene copolymer of the present invention as a main component can be obtained by mixing with a kneading machine such as a kneader, a Banbury or a roll in the same manner as for a normal chloroprene rubber. Next, a vulcanized adhesive is obtained by molding into a shape suitable for the purpose and vulcanizing and bonding with a metal. 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 rubber composition comprising a chloroprene copolymer as a main component and a metal according to the present invention has, in addition to the mechanical properties of rubber, vibration-proof performance, vulcanized adhesion to metal and heat resistance, Since the durability, such as ozone resistance, is balanced, it 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. As anti-vibration rubber for automobiles,
Engine mount, torsion damper, rubber bush, strut mount, bound bumper, helper rubber, member mount, stabilizer bush, air spring, center support bearing, rubber-containing propeller shaft, anti-vibration lever, companion 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. Further, the present invention can be applied to anti-vibration members for ships, aircraft, civil engineering, construction, industrial machinery, and the like.

[0033]

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 11 and Comparative Examples Polymerization for obtaining a chloroprene copolymer was carried out by continuously dropping an aqueous potassium persulfate solution at a polymerization temperature of 40 ° C. in a nitrogen atmosphere using a 5 L four-necked flask. It was carried out while.
The polymerization recipe for obtaining the copolymer is shown in Tables 1 and 2. Methacrylic acid as a monomer of (a) according to the present invention,
Acrylonitrile was used as the monomer of (b), glycidyl methacrylate was used as the monomer of (c), and 2-hydroxyethyl methacrylate was used as the monomer of (d). When the monomer conversion reached 80%, the polymerization was stopped by adding 100 ppm of diethylhydroxylamine.
A 2% aqueous NaOH solution was added to the obtained copolymer emulsion to adjust the pH to 9.0, and unreacted monomers were removed by steam stripping. Further, a 5% acetic acid aqueous solution was added to adjust the pH to 7.0, and then coagulated with a freezing drum, washed with water and dried to obtain each chloroprene copolymer.

[0035]

[Table 1]

[0036]

[Table 2]

Using the chloroprene rubber composition obtained by compounding using an 8-inch roll according to the compounding recipe shown in Table 3, the vulcanization adhesiveness was evaluated, and the vulcanized product was subjected to a physical property test. The measurement results are shown in Tables 4 and 5. Tensile strength of test specimens vulcanized at 160 ° C for 20 minutes with a hydraulic press,
The mechanical properties such as elongation and hardness are based on JIS K6251, and the anti-vibration properties are evaluated by applying a static shear modulus (Gs) obtained according to JIS K6386, a frequency of 100 Hz, and a vibration of 0.1% amplitude. The dynamic magnification (E '/ 3Gs) determined from the storage elastic modulus (E') of the sample. The compression set test of the sample vulcanized at 160 ° C. for 30 minutes was performed in accordance with JIS K6262. The metal test piece is made of iron (JIS G3141: SPCC-SD), sandblasted on the metal test piece in advance, further degreased, and then used as an adhesive treatment with Chemlock 20 using a brush.
5 was applied twice, and then Chemlock 220 was applied twice and subjected to an adhesion test. Evaluation of vulcanization adhesiveness is based on JIS
The test was performed based on a 90 ° peel test between a metal piece and rubber according to K6256 (adhesion test method for vulcanized rubber).

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

The materials used in Tables 3 and 6 are as follows. 1) Octalamine, an antioxidant manufactured by Uniroyal 2) SRF grade carbon black 3) Petroleum-based process oil

Example 12 In the case where the copolymer of Example 5 was used and 2 parts by weight of an epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd.) was blended at the time of roll blending according to the blending recipe shown in Table 6. Table 7 shows the measurement results.

Example 13 The copolymer of Example 5 was used to prepare a brominated epoxy resin (brominated epoxy resin manufactured by Asahi Ciba (grade 8011, epoxy equivalent 4
55 to 485, bromine content of 18 to 22% by weight)). Table 7 shows the measurement results.

[0044]

[Table 6]

[0045]

[Table 7]

[0046]

As shown in Tables 4, 5 and 7,
The rubber composition containing the chloroprene copolymer of the present invention as a main component has good adhesion to metal, and shows a low dynamic magnification, and further has mechanical properties of rubber and excellent compression set and heat resistance. Therefore, it is useful as an anti-vibration member, and is particularly suitable as an anti-vibration rubber for automobiles, particularly as an anti-vibration rubber for an engine mount.

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Claims (4)

[Claims] 1. A copolymer obtained by copolymerizing a 2-chloro-1,3-butadiene monomer with one or more of the following monomers (a) to (d): Vulcanized adhesive of a rubber composition mainly composed of: and a metal. (A) a monomer having a carboxyl group in the molecule (b) a monomer having a cyano group in the molecule (c) a monomer having an epoxy group in the molecule (d) a monomer having a hydroxyl group in the molecule Monomer 2. The monomer of (a) is methacrylic acid, and (b)
2. The vulcanized adhesive of a rubber composition and a metal according to claim 1, wherein the monomer (a) is acrylonitrile and the monomer (c) is glycidyl methacrylate. 3. The vulcanized adhesive according to claim 1, wherein the rubber composition contains an epoxy resin. 4. A vibration damping member comprising the vulcanized adhesive according to claim 1, 2 or 3.