JPS6241873B2 - - Google Patents

Description

[Detailed description of the invention]

Object of the Invention (Field of Industrial Application) The present invention relates to a weather strip for automobiles with improved wear resistance and adhesion. (Prior Art) Weather strips for automobiles use a base material made of rubber or synthetic resin. This automotive weather strip has soundproofing and
A wide variety of properties are required, such as weather resistance and, above all, abrasion resistance. Conventionally, methods of imparting wear resistance to weather strips include providing a chloroprene rubber coating coated with urethane paint on the surface, providing a silicone coating layer, and the like. However, the formation of the chloroprene rubber coating has the disadvantage of continuous molding and is also expensive. Furthermore, the silicon coating film has a drawback of poor abrasion resistance after weathering, and does not satisfy the above performance. On the other hand, in recent years, polyolefin-based vulcanized rubbers, such as ethylene-propylene-diene ternary copolymer rubber (EPDM) and ethylene-propylene copolymer rubber (EPM), have improved weather resistance, aging resistance, and ozone resistance compared to conventional synthetic rubber. Because of its excellent sex,
It has come to be used in many fields. (Problem to be solved by the invention) However, since the polyolefin vulcanized rubber described above has poor abrasion resistance, when it is used as a base material for automobile weather strips, a urethane paint or the like must be applied to its surface. There must be. However, since the vulcanized rubber does not contain unsaturated bonds or polar groups in the main chain of its constituent molecules, the resulting coating film is likely to peel off even when paint is applied. The current situation is extremely difficult. In order to solve the above problems, the present inventors conducted research on a primer composition that strengthens the adhesion of a urethane paint applied to polyolefin vulcanized rubber. They have also discovered a primer composition that does not impair the flexibility and flexibility that are the characteristics of the vulcanized rubber, and that has sufficient adhesion to the vulcanized rubber. Structure of the Invention (Means for Solving Problems) That is, the present invention provides a weather strip having a polyolefin vulcanized rubber as a base material.
A hydrocarbon polymer whose main chain is saturated or partially saturated and has at least one hydroxyl group at the end, and

A primer layer consisting of a compound having a bond (X is a halogen) was provided, and a polyurethane paint was applied thereon. (Function) The hydrocarbon polymer that is a component of the primer composition is a hydrocarbon polymer in which the main chain in the molecule is saturated or partially saturated. Furthermore, since it has a hydroxyl group in its main chain, it has good adhesion to urethane paints. In addition to this hydrocarbon polymer,

A primer composition containing a compound having a bond (X is a halogen) exhibits extremely strong adhesion to polyolefin vulcanized rubber and urethane paint. Therefore, if a urethane paint is applied to the surface of a weather strip based on the same vulcanized rubber via the above primer composition, the wear resistance after heat resistance and the wear resistance after weather resistance of the weather strip will be improved. Wear resistance will be significantly improved. (Example) Hereinafter, the base material, primer composition, and urethane paint constituting the automotive weather strip of the present invention will be explained by giving specific examples. The base material constituting the weather strip is polyolefin vulcanized rubber. Specific examples include ethylene-propylene-diene ternary copolymer rubber (EPDM) and ethylene-propylene copolymer rubber (EPM). Furthermore, examples include those containing other rubber components in amounts within a range that does not impair the properties of these copolymer rubbers. Namely, natural rubber (NR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), polyisoprene rubber (IR), chloroprene rubber (CR), or butyl rubber (IIR). ) etc. may be used in an amount of 1/2 part by weight or less of the polyolefin vulcanized rubber. The above-mentioned various vulcanized rubbers contain commonly used compounds, such as sulfur, morpholine, disulfide, dicumyl peroxide, etc. as vulcanizing agents, 2-mercaptobenzothiazole, zinc dimethyldithiocarbamate, and tetrachloride as vulcanization accelerators. Methylthiuram disulfide, etc., phenyl-α-naphthylamine, 2,6-di-t-butyl-p-cresol, etc. are used as antioxidants, antioxidants, and ozone deterioration inhibitors, and carbon black, etc. are used as fillers. Hydrous silicic acid, magnesium carbonate, clay, etc. are used, and dioctyl sebacate, mineral oil, etc. are used as plasticizers. Rubber foaming agents include N・N′-dinitrosopentamethylenetetramine, N・N′-dimethyl-N・
N'-dinitrosoterephthalamide, azodicarbonamide, azobisisobutyronitrile, benzenesulfonylhydrazide, p.p'-oxybis(benzenesulfonylhydrazide), toluenesulfonylhydrazide, etc. are also used as foaming aids. The agent contains urea, salicylic acid, etc., depending on the amount of foaming. Moreover, the presence or absence of foaming is adjusted as appropriate depending on the application location. Next, the composition of the primer composition consists of a hydrocarbon polymer (hereinafter referred to as a hydrocarbon polymer) whose main chain is saturated or partially saturated and has at least one hydroxyl group at the end, and

[Formula] A compound having a bond (X is a halogen). Specifically, the above-mentioned hydrocarbon polymer has an average molecular weight of 500 to 500,000, which has one or more, preferably 1.8 to 5, hydroxyl groups in one molecule, and whose main chain is saturated or partially saturated. Preferably 1000~
20,000 polyhydroxypolybutadiene polymer (Japanese Patent Application Laid-Open No. 142695/1983). Alternatively, polyhydroxypolyolefins having a hydroxyl group at the molecular end and having an average molecular weight of 1000 to 5000 (manufactured by Mitsubishi Chemical Industries, Ltd., trademarks: "Polytail H" and "Polytail HA") can also be exemplified. Also, in the molecule

[Formula] A compound having a bond (X is a halogen) is, for example, a halogenated succinimide such as N-bromsuccinimide, a halogenated isocyanuric acid such as trichloroisocyanuric acid or dichloroisocyanuric acid, or a halogenated hydantoin such as dichlorohydantoin. be. These compounds are added to the above hydrocarbon polymer 100
A primer composition is prepared by blending in a proportion of 100 parts by weight or less, preferably 50 parts by weight or less, and diluting with a solvent. The solvents used at this time are aromatic hydrocarbons such as benzene, toluene, and xylene, ethers such as dioxane and tetrahydrofuran, esters such as ethyl acetate and propyl acetate, or ketones such as methyl ethyl ketone. When diluting the primer composition with these solvents, the concentration is preferably 30% or less, and if it exceeds 30%, there is a risk of precipitation as solid content. Next, the urethane paint used in the present invention is not a special one, and a wide variety of commercially available urethane paints can be used regardless of whether it is a one-pack type or a two-pack type. Furthermore, no special equipment is required when applying the primer composition and urethane paint to the weatherstrip base material. That is, the above primer composition diluted with a solvent,
After adjusting the viscosity by heating if necessary, it may be applied using a normal coating method such as dipping, spraying, or brushing. Since this primer composition is a one-component type, it has a very long pot life, and if the viscosity increases due to evaporation of the solvent, the viscosity can be adjusted by adding the solvent again. Needless to say, the urethane paint may also be applied by the above-mentioned coating method. Further, after applying the urethane paint, silicone oil may be further applied for the purpose of preventing blocking or improving wear resistance. Next, the effects of the present invention will be specifically explained using the following examples. First, an EPDM compound having the composition shown in Table 1 was extruded and then vulcanized at 160°C for 30 minutes to produce a weather strip for an automobile.

[Table] In each of the following examples, urethane paints having the compositions shown in Table 2 were used.

[Table] The urethane prepolymer shown in Table 2 is a mixture of 100 parts by weight of the urethane polymer (A) shown below and 40 parts by weight of the urethane prepolymer (B). Urethane prepolymer (A): The composition shown in Table 3 was reacted in dry nitrogen gas at 80°C for 3 hours to obtain a urethane prepolymer.

[Table] Urethane prepolymer (B): The composition shown in Table 4 was reacted in dry nitrogen gas at 80°C for 3 hours to obtain a urethane prepolymer.

[Table] Example 1 A weather strip base material having the composition shown in Table 1 was immersed in the following primer composition.
After air drying for an hour, the urethane paint shown in Table 2 was applied and cured at room temperature for 24 hours.

[Table] In Examples 2 to 5 below, the composition of the primer was changed and the same treatment as in Example 1 was performed.

【table】

【table】

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[Table] In order to examine the abrasion resistance of the weatherstrip base materials treated in Examples 1 to 5 above, the following tests were conducted. (1) Wear resistance test using the Glass Edge abrasion tester, which is an improved version of the Gakushin abrasion tester: [Test conditions] Friction element: Glass (thickness 5 mm) Friction element cycle: 60 times/min Friction element stroke: 70 mm [ Test method] Normal wear: The base material is attached to the above testing machine, and the base material is rubbed to examine the wear property under normal conditions. The results of the above test are shown in Table-10.

[Table] (2) 180° bending test The weatherstrip base material treated in Examples 1 to 5 above was bent 180° to examine its followability. It showed good followability without any loss in flexibility and flexibility. The following comparative examples are those conventionally used as primers for polyolefin vulcanized rubber. The weatherstrip base material of the above example was subjected to the same treatment using these primers. Comparative Example 1 "Ester Resin-20" (trademark: Toyobo Co., Ltd., saturated polyester) and methyl ethyl ketone:
A primer composition consisting of a mixed solvent of toluene = 1:9 was prepared. Comparative Example 2 A primer composition consisting of "Vinyrite-VMCH" (trademark: manufactured by Union Carbide, vinyl chloride-vinyl acetate copolymer) and a mixed solvent of methyl ethyl ketone:toluene = 1:1 was prepared. Comparative Example 3 “Eslec-BM-2” (trademark: Sekisui Chemical Co., Ltd., butyral resin) and butanol:xylene=
A primer composition consisting of a 1:1 mixed solvent was prepared. Comparative Example 4 A primer composition consisting of "Orestar-M55-80A" (trademark: manufactured by Mitsui Toatsu Co., Ltd., moisture-curable polyurethane resin) and toluene was prepared. Comparative Example 5 “Desmofen-100” (trademark: manufactured by Bayer AG,
polyhydroxy compound) and “desmodyur”
A primer composition was prepared consisting of a 1:1.5 mixture of "R" (trademark: polyisocyanate manufactured by the same company) and a mixed solvent of methylene glycol, butyl acetate, ethyl acetate, and toluene. Comparative Example 6 A primer composition consisting of "Betucosol J-534" (trademark: Dainippon Ink & Chemicals, Co., Ltd., linseed oil-modified long oil alkyd resin), cobalt naphthenate (drying agent), and a mineral base was prepared. Comparative Example 7 “Betsukosol J-524” (Trademark: Dainippon Ink & Chemicals Co., Ltd., linseed oil modified long oil alkyd resin)
A primer composition consisting of xylene and a 4:1 mixture of "Super Betsukamine J-820" (trademark: manufactured by the same company, butylated melamine resin) was prepared. Comparative Example 8 A primer composition consisting of a 99:1 mixture of "Acryloid C-110V" (trademark: manufactured by Rohm & Haas, thermoplastic acrylic resin) and nitrocellulose and toluene was prepared. Comparative Example 9 4: "Acridik 47-712" (trademark: Dainippon Ink & Chemicals Co., Ltd., thermosetting acrylic resin) and "Supervetsucomin 47-508" (trademark: Dainippon Ink & Chemicals Co., Ltd., butylated melamine resin) 1 mixture and a mixed solvent of toluene and butyl acetate. The weatherstrip base materials treated in Comparative Examples 1 to 9 above were subjected to the testing apparatus described in (1) above to examine their abrasion resistance, and the results were as shown in Table 11.

【Table】 It can be seen that this is a significant improvement compared to the material. Effects of the Invention As detailed above, by applying a urethane paint to a base material made of polyolefin vulcanized rubber via the primer composition of the present invention, its wear resistance and adhesion are significantly improved. It was used in weather strips for automobiles with sufficient effect.

Claims (1)

[Scope of Claims] 1. Hydrocarbon whose main chain is saturated or partially saturated and has at least one hydroxyl group at the end, on the surface of the base material of a weather strip based on polyolefin vulcanized rubber. 1. A weather strip comprising a primer layer made of a polyurethane polymer and a compound having a bond of the formula (X is a halogen) in the molecule, and a coating layer made of a polyurethane paint.