JPS601192B2 - Automotive weather strip - Google Patents

Description

[Detailed description of the invention] The present invention relates to automotive weatherstrips.

Natural rubber, chloroprene rubber, styrene-butadiene copolymer rubber, etc. are used as materials for weatherstrips, but in addition to the functions of weatherstrips themselves, automotive weatherstrips also have soundproofing, weatherproofing, and other properties. sex,
A wide range of performance such as wear resistance is required. Until now, chloroprene rubber coated urethane paints and silicon coatings have been used as means to improve the abrasion resistance of the weatherstrip surface, but forming a chloroprene rubber coat is difficult in continuous molding and is costly. However, silicon coatings still have drawbacks in weather resistance and abrasion resistance (see Table 2 at the end), so urethane paints are a relatively good option for improving abrasion resistance. was. On the other hand, in recent years, ethylene-propylene terpolymer (EPDM) and ethylene-propylene polymer (EPR), which are ethylene-propylene rubbers, have improved weather resistance, aging resistance, ozone resistance, etc. compared to conventional synthetic rubber, and have been used in automobiles. However, ethylene-propylene rubber has poor surface abrasion resistance, and even when urethane paint is applied to improve the abrasion resistance, the urethane coating and ethylene - Due to the poor adhesion of propylene rubber, the purpose could not be achieved (see Table 2 at the end). Several treatment methods have already been tried as means to improve the defect of poor adhesion of ethylene-propylene rubber.

For example, polishing the surface with a wire brush, sandpaper, etc., [2] Irradiating with ultraviolet rays, '3) Soaking in concentrated sulfuric acid, ■ Treating with a mixed solution of organic monocarboxylic acid and phosphoric acid, '51 Altehydes. ■Painting with a mixture of chlorinated polypropylene and ethylenediamine, t7} Treating with chlorinated isocyanate, Oxidizing the surface by exposing to shelf ozone, '9} Treating with alkyl hypohalite, Work polymerization Examples of such methods include treatment with an epoxy resin modified with a fatty acid, an amine curing agent, and an organic solvent. However, in these conventional processing methods, ■ there is a tendency for uneven polishing to occur, ■ there are hygiene problems due to the generation of dust, ■ it causes deterioration of the vulcanizate, ■ there is danger in handling the processing agent, and ■ There are drawbacks such as requiring a special treatment agent, ■ The treatment process is complicated, and ■ Equipment costs are high. It was not always possible to improve the adhesion with the rubber. In order to improve the abrasion resistance of the surface of automotive weather strips based on ethylene-propylene vulcanized rubber, the present inventors have developed an approach to improve the adhesion between the ethylene-propylene vulcanized rubber and the urethane paint applied. Conducted research on rubber compositions.

As a result, we have developed an automotive product that uses a blended carboxylic sulfate of a functional hydrocarbon polymer containing a saturated aliphatic ring and an ethylene-propylene rubber compound as described below as a base material, and coats the surface with a urethane paint. It has been found that the weather strip has extremely good wear resistance. The present invention has been achieved based on this knowledge.

The present invention will be explained in detail below.

First, the functional hydrocarbon polymer containing a saturated aliphatic ring used in the present invention is a polymer as disclosed in JP-A-51-71391.

Particularly preferred is one obtained by hydrogenating a copolymer of a conjugated diene compound and an aromatic compound having a vinyl group. The molecular weight of this hydrocarbon polymer is usually 500-
50,000, preferably 1,000 to 30,000. This functional hydrocarbon polymer is obtained by hydrogenating a functional hydrocarbon polymer having an aromatic ring in the presence of a hydrogenation catalyst. can be obtained by polymerizing an aromatic monomer alone or together with other comonomers according to a conventional method. Examples of typical manufacturing methods include:
Examples include a method of polymerizing a monomer until it becomes a suitable low molecular weight polymer, and a method of oxidative decomposition of a high molecular weight polymer. Examples of their manufacturing methods are
-819 No., Special Publication Showa No. 342, Special Publication No. 42-22
No. 048, Special Publication No. 38-5993, Special Publication No. 40-147
No. 47, Japanese Patent Publication No. 47-36273, and other publications. Examples of the above conjugated gene compounds include 1 and 3
-Butadiene, isoprene, 1,3-bentadiene, 2
・3-dimethylbutadiene, etc. Examples of the aromatic compounds having a vinyl group include styrene, pinyltoluene, vinylnaphthalene, phenylbutadiene, methylstyrene, divinylbenzene, coumaron, iden,
Examples include cinnamic acid, vinylphenol, vinylbenzoic acid, etc. These can be used alone or as a mixture. The aromatic monomer content in the above-mentioned functional hydrocarbon polymer having an aromatic ring is 1 to 1 with respect to the polymer.
0% by weight, preferably 5-7% by weight. As a method for hydrogenating this functional hydrocarbon polymer having an aromatic ring, precious metals such as palladium, platinum, rhodium, osmium, and ruthenium are used alone as a catalyst, or carbon, alumina, silica/alumina, and diatom are used as catalysts. Master,
There is a method in which hydrogenation is carried out using a waste material such as barium carbonate or calcium carbonate (see JP-A-51-76387). The hydrocarbon polymer containing a saturated aliphatic ring as used in the present invention has a hydroxy group, a carboxy group, etc. as a functional group, and the content of these functional groups is preferably one or more per molecule of the polymer. is more than 1.9 hard. The ethylene-propylene vulcanized rubber used in the automotive weather strip of the present invention may contain, in addition to ethylene-propylene turbopolymer or ethylene-propylene polymer, other rubbers in amounts that do not impair these properties. Ingredients such as natural rubber (NR), styrene-butadiene copolymer rubber (SBF), polybutadiene rubber (BR), acrylonitrile butadiene (NBR), polyisoprene (
IR), chloroprene rubber (CR), butyl rubber (11
R), and other resin components such as polyethylene (PE),
Polypropylene (PP), ethylene-vinyl acetate copolymer (E
VA) and the like are also included.

In this case, the content of other rubber components is usually 1/2 or less of the amount of the ethylene-propylene terpolymer or ethylene-propylene polymer. In addition, compounds commonly used in rubber compounds, such as sulfur, morpholine, disulfide, and dicumyl peroxide as vulcanizing agents, and 2-mercabutobenzothiazole, dimethyl peroxide as vulcanization accelerators, etc. Zinc dithiocarbamate, tetramethylthiuram disulfide, etc., phenyl-Q naphthylamine as an anti-aging agent, antioxidant, and ozone deterioration inhibitor.
Needless to say, 2,6-di-t-butyl-p-cresol and the like, carbon, hydrated silicic acid, magnesium carbonate, and clay as fillers, and dioctyl sebacate, mineral oil, etc. as plasticizers are used.

In addition, as foaming agents for rubber, N・N'-dinitroso bentamethylene tetramine, N・N'-dimethyl-N,
N'-dinitrosoterephthalamide, azodilbonamide, azobiisof.

Tyronitrile, benzene sulfonyl hydrazide, P
．． P'-oxybis(benzenesphonyl hydrazide,
As a foaming aid such as toluenesulfonyl hydrazide, urea, salicylic acid, etc. may be optionally blended depending on the amount of foaming. Moreover, the presence or absence of foaming is arbitrarily adjusted depending on the application location.・
The urethane paint used in the present invention is, for example, a mixture of urethane polymer, silicon oxide, carbon black, silicon, etc., and a solvent.

An example of the above-mentioned urethane polymer is - obtained by subjecting a urethane prepolymer produced from a bifunctional polyol and a diisocyanate to a chain extension reaction with a low-molecular diol.
Examples include liquid urethane polymers or two-component urethane polymers obtained by mixing a urethane prepolymer produced from a 2- to 4-functional polyol and a diisocyanate with a 2- to 4-functional polyol immediately before use.

In order to manufacture the automotive weather strip of the present invention, a urethane paint is applied to the above-mentioned blended vulcanized rubber molded by a conventional molding method such as extrusion molding, compression molding, or injection molding to provide a sealing effect. A urethane coating layer is formed by applying it to the side by a coating method such as spraying or brushing, and is dried and cured.

Incidentally, silicone may be further coated on this automotive weather strip in order to improve wear resistance and prevent blocking properties. Due to the above structure, the automotive weather strip of the present invention has excellent adhesion between the blended vulcanized rubber and the urethane coating layer,
Wear resistance is significantly improved compared to conventional products.

Examples of the present invention will be listed and explained below.

The physical property tests were conducted in accordance with the following. {1}
Wear resistance test using a glass edge abrasion tester that is an improved version of the Gakushin abrasion tester Test conditions Friction element Glass (thickness 5 side) Friction element cycle 60 times/min Friction element stroke 7 ribs (2' peeling test) (JISD0202) Adhesion test '31 Bending test (JISK6301) Followability test example 160 parts of a rubber compound consisting of 30 parts of combined, 67.5 parts of carbon book, 35 parts of mineral oil, 5 parts of zinc white, 1 part of stearic acid, 2 parts of vulcanization accelerator, and 1.5 parts of sulfur. The vulcanizate obtained by carrying out 3-powder sulfurization at 10,000° C. was molded into a weather strip for automobiles as a base material, a urethane paint was applied to the surface, and the product was dried and cured at 10,000° C. for 3 minutes.

Example 2 Polymer 5 obtained by polymerizing 75 parts of 1.3-butadiene and 25 parts of styrene using a hydrogen peroxide solution and then hydrogenating it, EPDMIO part, 67.5 parts of carbon black, mineral oil 35 parts, zinc white 5 parts, stearic acid 1 part, vulcanization accelerator 2. A rubber compound consisting of 1.5 parts of sulfur is vulcanized at 160 qo for 30 minutes, and the resulting vulcanizate is used as a base material to form an automotive weather strip, and the surface is coated with urethane paint. The powder was then dried and hardened at 100 pm to give a product.

Example 3 A polymer obtained by polymerizing 1,3-butadiene 64% and styrene 36% using a hydrogen peroxide solution and then hydrogenating it, EPDMIO base, 67.5 parts of carbon black, mineral A vulcanizate obtained by subjecting a rubber compound consisting of 35 parts of oil, 5 parts of zinc white, 1 part of stearic acid, 2 parts of a thickening accelerator, and 1.5 parts of iodine at 160 qo for 3 cycles and 0 cycles. Formed into automotive weather strips as a base material,
A urethane paint was applied to the surface, and the product was dried and cured at 10°C for 3 powders.

Example 4 100% of 1.3-butadiene and 10% of styrene
The polymer obtained by polymerizing 0.0 and hydrogen peroxide solution and then hydrogenating it contains 3 parts, EPDMIO parts, 67.5 parts of carbon black, 35 parts of mineral oil, 5 parts of zinc fist, 1 part of stearic acid. Part, vulcanization accelerator 2. The vulcanizate obtained by vulcanizing a rubber compound consisting of 1.5 parts of sulfur at 160 qC for 3 minutes was used as a base material and formed into an automobile weather strip, and the surface was coated with urethane paint. , 3 at 100℃
The product was dried and cured for a few minutes.

Example 5 50 parts of the hydrogenated polymer used in Example 4,
EPDMIO anchor, 67.5 parts of carbon black, 35 parts of mineral oil, 5 parts of zinc white, 1 part of stearic acid, 2. vulcanization accelerator. 160q of a rubber compound consisting of 1.5 parts of Ikaribe Io
A vulcanized rubber obtained by hot-flowing at C for 30 minutes was used as a base material, and a urethane paint was applied thereto, followed by drying and curing at 10,000 for 3 minutes to produce a weather strip for an automobile.

Example 6 100 parts of hydrogenated polymer used in Example 4, EPDM
IO anchor, 67.5 parts of carbon black, 35 parts of mineral oil, 5 parts of zinc white, 1 part of stearic acid, 2 parts of vulcanization accelerator,
Using a vulcanizate obtained by subjecting a rubber compound consisting of 1.5 parts of sulfur to 3-powder sulfurization at 160 oo as a base material, molding it,
A urethane paint was applied to the surface and dried and cured at 100° C. for 3 minutes to produce a weather strip for an automobile.

Reference example 1 50 parts of polyethylene adibate (molecular weight approximately 2000),
EPDMIO part, carbon black 67.5 parts, mineral oil 35 parts, zinc white 5 parts, stearic acid 1 part, vulcanization accelerator 2. 160 parts of a rubber compound consisting of 1.5 parts of
After 3 removal of sulfur and 0 sulfur at °C, it was molded, coated with urethane paint, and dried and cured at 100 qo for 30 minutes to produce a weather strip for automobiles.

Reference example 2 Polyethylene oxide glycol (molecular weight approximately 4000)
50 parts, EPDMIO parts, carbon black 67.5
1 part of mineral oil, 5 parts of zinc white, 1 part of stearic acid, and 2 parts of vulcanization accelerator.
After heating at 60°C for 30 minutes, it was molded, coated with urethane paint, and dried and cured at 100°C for 3 wells to produce an automobile weather strip.

Reference Example 3 50 parts of polypropylene oxide glycol (molecular weight approximately 2000), parts of EPDMIO, 67.5 parts of carbon black, 35 parts of mineral oil, 6 parts of zinc white, 1 part of stearic acid, 2. A rubber compound consisting of 1 part and 1.5 parts of iodine was ground to 3 powders at 160°C.

After sulfurizing, molding, applying urethane paint, 10
000 for 30 minutes to produce a weather strip for an automobile. Examples 1 to 6 and Reference Examples 1 to 3 above
The physical property test results are shown in Table 1.

From these results, the automotive weather strip of the present invention has excellent adhesion between the vulcanized rubber base material and the urethane paint film layer, and has better abrasion resistance and deformation followability than conventional products. It turns out that it is excellent.

Table 1 Note) *1: In the wear resistance test, the base material was not exposed even after 50,000 times of friction.

*2: Base material exposure based on the number of times stated. I agree with all reference examples 1-3.
*3: Wear resistance is based on normal wear described below. Table 2 Wear Resistance Test Results 1: Normal wear: The sample was attached to a testing machine, rubbed, and the wear resistance under normal conditions was examined o2: Weather resistance wear: Exposure to a weatherometer using two carbon arc lamps for 200 hours. After that, rub it and examine its weather and abrasion resistance.

Claims (1)

[Claims] 1. Blend vulcanizate of a functional hydrocarbon polymer containing a saturated aliphatic ring obtained by hydrogenating a copolymer of a conjugated diene compound and an aromatic compound having a vinyl group and an ethylene-propylene rubber compound. A weather strip for automobiles, characterized in that the surface is coated with urethane paint.