JPH09169874A - Modification of physical property of polymer and modifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer composition which gives a well balanced crosslinked material particularly having a superior heat aging resistance, tear resistance and dynamic durability by using a specific component in a crosslinking process using an organic peroxide. SOLUTION: This is a polymer composition consisting of a polymer, an organic peroxide, a sulfur phenol resin and/or a sulfur alkyl phenol resin. The polymer is a rubber and/or a resin. The sulfur phenol resin and/or the sulfur alkyl phenol resin are synthesized by making phenol or an alkyl phenol react with sulfur. Sulfurized-p-tert.-butyl phenol resin and sulfurized-p-tert.-amyl phenol resin can be mentioned as examples of a sulfurized alkyl phenol resin. The adequate amount of addition of the sulfurized phenol resin and/or the sulfurized alkyl phenol resin is 0.1-5.0 pt.wt. to 100 pts.wt. rubber and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for organic peroxide crosslinking of a polymer and a method for modifying the physical properties of the polymer. Further, it relates to a polymer physical property modifier as a novel use of a sulfurized phenol resin and / or a sulfurized alkylphenol resin for a polymer. The method of crosslinking rubber or resin with an organic peroxide has been used for a long time because a crosslinked product having good heat resistance and compression set resistance can be obtained. Since the cross-linking structure by the organic peroxide is a carbon-carbon cross-link, as compared with sulfur cross-linking, which is a general vulcanization method for rubber, the tensile strength and tear strength are low, and the dynamic properties are inferior. It is said.

[0002]

Therefore, in organic peroxide crosslinking of rubbers and resins, co-crosslinking agents are often used together for the purpose of improving the physical properties of the crosslinked product, especially the dynamic properties. Co-crosslinking agents include sulfur, polyfunctional monomers, metal salts of methacrylic acid or acrylic acid, dioximes, etc., but must satisfy durability without deteriorating heat resistance and compression set resistance. Is difficult

As a method for modifying the physical properties of rubber or resin in organic peroxide crosslinking, a method of adding a co-crosslinking agent such as a polyfunctional monomer, a polyfunctional polymer, sulfur or oxime is generally known. There is. However, when sulfur is used among these, although the tensile strength and the like are improved, the compression set is largely reduced, and the odor during vulcanization is also a problem. Further, although the use of a polyfunctional monomer or a polyfunctional polymer shows an improvement in physical properties, a decrease in dynamic durability is seen, and a satisfactory physical property modifier has not yet been developed. Further, the present applicants disclose in JP-A-6-313066 a method of suppressing early vulcanization of rubber by using a sulfurized phenol resin and / or a sulfurized alkylphenol resin.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to the cross-linking of rubbers and resins (hereinafter, referred to as rubber and resin together in this specification, etc.) with an organic peroxide to determine the physical properties of the cross-linked product. The purpose is to provide a method of improving in a well-balanced manner.

[0005]

Means for Solving the Problems The present invention is a composition comprising a sulfurized phenol resin and / or a sulfurized alkylphenol resin compounded for the purpose of modifying physical properties when crosslinking rubber or the like with an organic peroxide. It is an application as a physical property modifier, a method for modifying physical properties of rubber and the like that allows it to coexist, and a physical property modifier for rubber and the like. By adding a sulfurized phenol resin and / or a sulfurized alkylphenol resin to rubber or the like and crosslinking with a peroxide, a well-balanced physical property of the crosslinked product can be obtained. In particular, it is possible to give rubber and the like physical properties excellent in heat aging resistance, tear resistance and dynamic durability.

The sulfurized phenol resin and sulfurized alkylphenol resin of the present invention release sulfur during the crosslinking reaction and are synthesized by the reaction of phenol or alkylphenol with sulfur. Examples of sulfurized alkylphenol resins include sulfurized-p-tert-butylphenol resin and sulfurized-p-tert-amylphenol resin.

As the rubber according to the present invention, natural rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, ethylene propylene terpolymer, ethylene propylene copolymer, silicone rubber, urethane rubber, fluoro rubber, acrylic rubber, chlorinated polyethylene, etc. Can be mentioned. Examples of the resin include polyethylene, ethylene vinyl acetate copolymer, polyvinyl chloride and the like.

The sulfurized phenolic resin according to the present invention and /
Or, as a crosslinking agent for an organic peroxide applicable when using a sulfurized alkylphenol resin, for example, dicumyl peroxide, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, di- ( tert
-Butylperoxyisopropyl) benzene, 2,5-
Examples include dimethyl-2,5-di (tert-butylperoxy) hexane and benzoyl peroxide.

In this compounding system, as a co-crosslinking agent, for example, a polyfunctional monomer such as trimethylolpropane trimethacrylate, ethylene dimethacrylate, triallyl cyanurate, triallyl isocyanurate, a metal of methacrylic acid or acrylic acid is used. A salt, a polyfunctional polymer using the functional group of 1,2-polybutadiene, a sulfur-containing compound, etc. can be blended. In addition to this compounding system, compounding agents known in the ordinary rubber and resin industry, such as metal oxides such as zinc oxide and magnesium oxide, calcium carbonate, silica and carbon black, and other fillers or reinforcing agents. Agents, paraffin-based, naphthenic- or aromatic-based processing oils, softeners, plasticizers, various higher fatty acids such as stearic acid, colorants and pigments, antioxidants, foaming agents, UV absorbers, and other compounding agents Etc. can be blended as needed.

The compounding of various compounding agents according to the present invention with rubber or the like is prepared by mixing them with a conventionally used mixer such as an open roll, a Banbury mixer, an extruder or a pressure kneader.

[0011]

If the sulfur-releasing sulfurized phenolic resin or sulfurized alkylphenol resin of the present invention is added in an excessively large amount, the physical properties will not be balanced and it is uneconomical. If it is too small, the effect cannot be obtained. Therefore, the addition amount of the sulfurized phenol resin and / or the sulfurized alkylphenol resin according to the present invention is 0.
1 to 5.0 parts by weight, and more preferably 0.5 to
An amount of 2.0 parts by weight is suitable.

[0012]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 A rubber composition was obtained by mixing according to a conventional method according to the formulation shown in Tables 1 and 2. The vulcanization behavior of the compounded rubber was measured using a rheometer. For the vulcanized sample of the compounded rubber composition, a tensile test was conducted in accordance with JIS K6301.
A heat aging test, a compression set test, a tear test, and a flex crack test were performed. Among the results, Comparative Examples are shown in Table 3 and Examples are shown in Table 4. In Tables 1 and 2, Mitsui EPT3045 is a product name of EPDM manufactured by Mitsui Petrochemical Co., Ltd., Park Mill D.
-40 is the trade name of dicumyl peroxide manufactured by NOF CORPORATION, Sunester TMP is the trade name of trimethylolpropane trimethacrylate manufactured by Sanshin Chemical Industry Co., Ltd., and Sanfel R is dithiodimorpholine manufactured by Sanshin Chemical Industry Co., Ltd. Brand name, DIC No. 1 is the trade name of sulfurized alkylphenol resin manufactured by Dainippon Ink and Chemicals, Inc., V
ultac # 7 is a trade name of a sulfurized alkylphenol resin manufactured by Pennwalt, and Sumifine V-200 is a trade name of a sulfurized alkylphenol resin manufactured by Sumitomo Chemical Co., Ltd.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

[Table 4]

Example 2 According to the formulation shown in Table 5, the ingredients were mixed by a conventional method,
A rubber composition was obtained. The vulcanization behavior of the compounded rubber was measured using a rheometer, and for the vulcanized sample of the compounded rubber composition, in accordance with JIS K6301, tensile test, heat aging test, compression set test, tear test, flexion test. A crack test was conducted and the results are shown. In Table 5, Perhex 3
M-40 is a trade name of 1,1-bis (tertiary butylperoxy) -3,3,5-trimethylcyclohexane manufactured by NOF CORPORATION.

[0018]

[Table 5]

Example 3 According to the formulation shown in Table 6, mixing was carried out using a kneader at a rotation speed of 30 rpm and a temperature of 110 ° C., and then crosslinking was carried out to evaluate the crosslinked product. Table 6 also shows the results.

[0020]

[Table 6]

[0021]

[Effects of the Invention] In crosslinking rubber or the like with an organic peroxide,
According to the modification method of the present invention, tensile strength, tensile stress,
It is possible to obtain a well-balanced crosslinked product having excellent heat aging resistance, tear resistance, and dynamic durability.

Claims (12)

[Claims] 1. A polymer composition comprising a polymer, an organic peroxide, a sulfurized phenol resin and / or a sulfurized alkylphenol resin. 2. The composition according to claim 1, wherein the polymer according to claim 1 is a rubber and / or a resin. 3. A method for modifying crosslinked physical properties of a polymer, wherein a sulfurized phenol resin and / or a sulfurized alkylphenol resin is allowed to coexist during organic peroxide crosslinking of the polymer. 4. A method for improving heat aging resistance of a polymer, characterized in that a sulfurized phenol resin and / or a sulfurized alkylphenol resin is allowed to coexist during organic peroxide crosslinking of the polymer. 5. A method for modifying the tear strength of a polymer, wherein a sulfurized phenol resin and / or a sulfurized alkylphenol resin is allowed to coexist during organic peroxide crosslinking of the polymer. 6. A method for modifying dynamic durability of a polymer, characterized in that a sulfurized phenol resin and / or a sulfurized alkylphenol resin are allowed to coexist during organic peroxide crosslinking of the polymer. 7. The polymer according to any one of claims 3 to 6 is rubber and / or
Alternatively, it is a resin, and the method for modifying physical properties according to claims 3 to 6. 8. A cross-linking physical property modifier for polymer organic peroxide cross-linking, which comprises a sulfurized phenol resin and / or a sulfurized alkylphenol resin as a main component. 9. A heat-resistant antioxidant for crosslinking a polymer organic peroxide, which comprises a sulfurized phenol resin and / or a sulfurized alkylphenol resin as a main component. 10. A tear strength modifier for polymer organic peroxide crosslinking, comprising a sulfurized phenol resin and / or a sulfurized alkylphenol resin as a main component. 11. A dynamic durability modifier for polymer organic peroxide crosslinking, which comprises a sulfurized phenol resin and / or a sulfurized alkylphenol resin as a main component. 12. The physical property modifier according to claim 8, wherein the polymer according to any one of claims 8 to 11 is a rubber and / or a resin.