JPS6040461B2 - Automotive weather strip - Google Patents

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to automotive weatherstrips.

Traditionally, materials such as natural rubber, chloroprene rubber, and styrene-butadiene copolymer rubber have been used for weatherstrips. A wide range of performance is required, including wear resistance and abrasion resistance. Until now,
As a means to improve the abrasion resistance of the weatherstrip surface, urethane paints coated with chloroprene rubber and silicone coatings were explored, but forming a chloroprene rubber coating was difficult in continuous molding and was expensive. can be,
Furthermore, since silicone coatings have poor weather resistance and abrasion resistance, urethane paints have been used as a relatively good solution for improving abrasion resistance (silicon coatings and urethane coatings have been used). (See Table 2 at the end for each product.) 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 its abrasion resistance, the urethane coating does not form properly. Due to the poor adhesion of ethylene-propylene rubber, it was impossible to achieve the intended purpose. Several treatment methods have already been tried as means to improve the defect of poor adhesion of ethylene-propylene rubber. For example {1)
Polish the surface with a wire brush, sandpaper, etc.
■Irradiate with ultraviolet rays, '3} Soak in concentrated sulfuric acid, '4}
Treatment with a mixture solution of organic monocarboxylic acid and phosphoric acid, [5} Treatment with aldehydes, '6) Painting with a mixture of chlorinated polypropylene and ethylenediamine, '7} Treatment with chlorinated isocyanate, '8 }Exposing to ozone to oxidize the surface, '9} Treating with alkyl hypohalite, treating with 00 polymerized fatty acid-modified eboxy resin, amine curing agent, and organic solvent. However, in these conventional processing methods, 1) the polishing condition tends to be uneven, 2) there are hygiene problems due to the generation of dust, 2) it leads to the deterioration of the vulcanizate;
Handling of the processing agent is dangerous; ■Special processing agent is required. ■The treatment process is complicated, ■The equipment is expensive, and other disadvantages exist, and even with such treatment, the adhesion between the urethane paint and the ethylene-propylene vulcanized rubber is not guaranteed. There was no guarantee that it would improve. In order to improve the abrasion resistance of the surface of an automotive weather strip based on ethylene-propylene vulcanized rubber, the present inventors developed a primer that improves the adhesion between the ethylene-propylene vulcanized rubber and the urethane paint applied. After researching the composition, they discovered a primer composition that does not impair the flexibility and flexibility that are the characteristics of vulcanized rubber, and also has sufficient adhesion to the vulcanized rubber base material. Ta.

In the present invention, this primer composition is applied to a urethane paint coating of an automobile weather strip based on ethylene-propylene vulcanized rubber. That is, the present invention uses ethylene-propylene-based vulcanized rubber as a base material, coats it with a functional hydrocarbon polymer containing a saturated aliphatic ring and having a hydroxyl group as a functional group, "on top of that," An object of the present invention is to provide an automobile weatherstrip characterized by being coated with a urethane paint.Hereinafter, the present invention will be explained in detail.
Ethylene-propylene terpolymer vulcanized rubber or
Ethylene-propylene-polymer sulfur rubber is used, but a functional hydrocarbon polymer containing a saturated aliphatic ring and having a hydroxyl group as a functional group is used as a primer for the base material, as described in Japanese Patent Application Laid-open No. It is a polymer as shown in Japanese Patent No. 51-71391.

Particularly preferred are those 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 50
0~50,00 Castle order, preferably 1,000~30,00
0. 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. Typical examples of production methods include a method in which a monomer is polymerized until it becomes a suitable low molecular weight polymer, and a method in which a high molecular weight polymer is oxidized and decomposed. Examples of their manufacturing methods are Tokko Sho 37-18190, Mochiko Sho 38-342, Samurai Sho 42-22048, Mochiko Sho 5993, and Tsubaki Sho 4.
It is described in Japanese Patent Publication No. 0114747 and Japanese Patent Publication No. 47136273. Examples of the above-mentioned conjugated diene compounds include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, etc., and examples of the above-mentioned aromatic compounds having a pinyl group include styrene. , vinyltoluene, vinylnaphthalene, phenylbutadiene, methylstyrene, divinylbenzene, coumaron,
Examples include cinnamic acid, vinylphenol, and vinylbenzoic acid. 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 10% by weight, preferably 5 to 7% by weight, based on the polymer. 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,
There is a method of hydrogenation using a carrier such as carbon dioxide, barium carbonate, or calcium carbonate (see Tokukan Sho 51-76 No. 7). The functional hydrocarbon polymer containing a saturated aliphatic ring used in the present invention has a hydroxyl group as a functional group, and the content thereof is preferably 1 or more per molecule of the polymer, preferably 1. It is more than sealing. To give one example, a copolymer obtained by placing 1,3-butadiene and styrene in an arbitrary ratio in an autoclave and polymerizing in inpropyl alcohol with 60% hydrogen oxide in argon, Then, hydrogenation is carried out in cyclohexane using a carbon-supported ruthenium catalyst to obtain the corresponding functional hydrocarbon polymer.

The above-mentioned functional hydrocarbon polymer containing a saturated aliphatic ring and having a hydroxyl group as a functional group may be used as it is or after being dissolved in an organic solvent.

In this case, the organic solvents include n-hexane, cyclohexane, benzene, toluene, xylene, chloroform,
Various organic solvents include carbon tetrachloride, trichlorethylene, tetrahydrofuran, and carbon disulfide, and these can be used alone or in a mixture of two or more.

The urethane paint used in the automotive weather strip of the present invention is, for example, a mixture of urethane polymer, silicon oxide, carbon black, silicon, etc., and a solvent.

Examples of the above urethane polymer include a one-component urethane polymer obtained by subjecting a urethane prepolymer produced from a bifunctional polyol and a diisocyanate to a chain extension reaction with a low molecular weight diol, or a one-component urethane polymer produced from a 2- to 4-functional polyol and a diisocyanate. A two-component urethane polymer obtained by mixing a di- to tetra-functional polyol with a urethane prepolymer produced by the above method immediately before use is mentioned.

In addition to the ethylene-propylene sorter polymer or the ethylene-propylene polymer, the ethylene-propylene vulcanized rubber used in the automotive weather strip of the present invention may contain other materials in an amount that does not lose these properties. Rubber components, such as natural rubber (NR), styrene-butadiene copolymer rubber (SBR), polyptadiene rubber (BR), acrylonitrile butadiene (NBR), polyisoprene (IR), and rubber.

Also included are loprene rubber (CR), butyl rubber (11R), and those containing other resin components such as polyethylene (PE), polypropylene (PP), and ethylene-vinyl acetate copolymer (EVA). In this case, the content of other rubber components is usually 1/2 or less of the ethylene-propylene terpolymer or ethylene-propylene polymer. In addition, the compound usually used for this vulcanized rubber,
That is, sulfur as a bulking agent, morpholine, disulfide, dicumyl peroxide, etc. as a vulcanization accelerator, 2
-Mercaptobenzothiazole, zinc dimethyldithiocarbamate, tetramethylthiuram disulfide, etc.
Anti-aging agent, antioxidant. Phenyl-Q naphthylamine, 2,6-di-t-butyl-p-cresol, etc. are used as ozone deterioration inhibitors, carbon, hydrous silicic acid, magnesium carbonate, clay, etc. are used as fillers, and dioctyl sebacate, mineral oil, etc. are used as plasticizers. Needless to say, there are.

In addition, as foaming agents for rubber, N,N'-dinitroso bentamethylene tetramine, N,N'-dimethyl-N,
N'-dinitrosoterephthalamide, azodicarbonamide, azobisisobutyronitrile, benzene sulfonyl hydrazide, P,P'-oxybis (benzenesulfonyl hydraside, toluenesulfonyl hydrazide, etc.) Foaming infantile agents include urea, salicylic acid, etc. may be arbitrarily arranged depending on the amount of foaming.

Moreover, the presence or absence of foaming is arbitrarily adjusted depending on the application location. To manufacture the automotive weather strip of the present invention,
The above-mentioned primer is applied by spraying, brushing, or other painting methods to the sealing side of the ethylene-propylene vulcanized rubber, which has been molded by conventional extrusion, compression, or injection molding. After drying at a temperature ranging from room temperature to about 200° C., a urethane paint is coated thereon by a normal coating method to form a urethane coating layer, and then dried and cured.

In addition, on top of this automotive weather strip, in order to improve wear resistance and prevent blocking properties,
Furthermore, silicone may be applied. The automotive weather strip of the present invention has excellent adhesion between the ethylene-propylene vulcanized rubber and the urethane coating layer through a special primer, so it has much better abrasion resistance than conventional products. It becomes something.

Examples of the present invention are listed below.

In addition, the physical property test is based on the following.

'11 Wear resistance test using a glass edge abrasion tester that is an improved version of the Gakushin type abrasion tester Test conditions Friction element Glass (thickness 5 rails) Friction element cycle 60 sub/min Friction element stroke 7 sides Test method Normal wear: Attach the sample to the above testing machine, rub the sample, and examine the abrasion properties under normal conditions.

Weather and abrasion resistance: After being exposed to a Weatherometer using two carbon arc lamps for 20 hours, the material is rubbed to examine its weather and abrasion resistance.

{21 Adhesion test by peeling test (JISD0202) {3' Followability test by bending test (JISK6301) The rubber base material used in the example was prepared as follows.

Ethylenep.

Pyreneterpolymer 10 base, carbon black 57
．． 16 parts of a rubber compound containing 5 parts of mineral oil, 35 parts of mineral oil, 5 parts of zinc white, 1 part of stearic acid, 2 parts of a galvanic accelerator, and 1.5 parts of sulfur.
Perform 3 beard vulcanization at 0:00 o'clock. An ethylene-propylene ester polymer was prepared. Further, the functional hydrocarbon polymer containing a saturated aliphatic ring and having a hydroxyl group as a functional group used in the Examples was prepared by the following Production Method A or Production Method B.

Manufacturing method A: 1,3-butadiene 7 fins, styrene 2 fins in autoclave
Add 7 volumes of inpropyl alcohol and 1 volume of 60% hydrogen peroxide solution, and polymerize in Arungon at 9000 for 5 hours.

Thereafter, hydrogenation was carried out in cyclohexane using carbon-filled ruthenium and hydrogen gas to obtain a functional hydrocarbon polymer. Production method B: Polymerization and hydrogenation reactions were carried out in the same manner as in production method A using six 1,3-butadiene vessels and three styrene vessels to produce a functional hydrocarbon polymer.

Example 1 A functional hydrocarbon polymer containing a saturated aliphatic ring and having a hydroxyl group as a functional group prepared by Production Method A was
After heating and melting at 0° C. and dipping Motomura into it, a urethane paint was applied and dried and cured at 10,000° C. for 3 coats to produce a weather strip for automobiles.

Example 2 Functional hydrocarbon polymer 10 containing the same saturated aliphatic ring as used in Example 1 and having a hydroxy group as a functional group
1 part was dissolved in 90 parts of cyclohexane, and the solution was applied to a base material to produce a weather strip for an automobile in the same manner as in Example 1.

Example 3 5 parts of a functional hydrocarbon polymer containing the same saturated aliphatic ring as used in Example 1 and having a hydroxyl group as a functional group was dissolved in 95 parts of n-hexane, and the solution was applied to a substrate. An automobile weather strip was manufactured in the same manner as in Example 1.

Example 4 5 parts of a functional hydrocarbon polymer containing a saturated aliphatic ring and having a hydroxyl group as a functional group prepared by Production Method B was dissolved in 95 parts of toluene, and the solution was applied to a substrate, and Example 1 An automobile weather strip was manufactured in the same manner as above.

Example 5 1 part of a functional hydrocarbon polymer containing the same saturated aliphatic ring used in Example 4 and having a hydroxyl group as a functional group was dissolved in 9 ml of toluene, and the solution was applied to a substrate. A weather strip for automobiles was produced in the same manner as in Example 'r.

Example 6 5 parts of a functional hydrocarbon polymer containing the same saturated aliphatic ring as used in Example 4 and having a hydroxyl group as a functional group was dissolved in 95 parts of tetrahydrofuran, and the solution was applied to a substrate. An automobile weather strip was manufactured in the same manner as in Example 1.

Control Example 1 "Ester Resin 20" (trade name: manufactured by Toyobo Aya Co., Ltd., saturated polyester) was dissolved in a mixed solvent [methyl ethyl ketone '1': toluene side] and applied to the same base material used in Example 1. After drying at room temperature, a urethane paint was applied and dried by heating at 90 qo for 8 minutes to produce an automobile weather strip.

'Comparative Example 2 "Pinilite VMCH" (trade name: manufactured by Union Carbide Co., Ltd., pinychloride-vinyl acetate copolymer resin) was dissolved in a mixed solvent (methyl ethyl ketone 01: toluene '1), and the same procedure as in Example 1 was carried out. Apply to the same substrate used,
After drying at room temperature, a urethane paint was applied and dried by heating at 90° C. for 8 minutes to produce a weather strip for an automobile.

Control example 3 "Essurek BM-2" (trade name: Sekisui Chemical Co., Ltd., butyral resin) dissolved in a mixed solution of [Ptanol 01: Xylene '11] was used and applied to the same substrate used in Example 1. After drying at room temperature, apply urethane paint9.
A weather strip for an automobile was manufactured by drying and curing with Pi○ for 8 minutes.

Control example 4 "Orestar-M55-8 sail" (trade name: manufactured by Mitsui Tosho, moisture-curing polyurethane resin) dissolved in toluene was applied to the same base material as used in Example 1, and was heated at room temperature. After drying, a urethane paint was applied and dried and cured at 90° C. for 8 minutes to produce a weather strip for an automobile.

Control example 5 “Desmophen 100” (product name: Bayer AG, polyhydroxy compound) 10 layers and “Desmodur L” (
Product name: manufactured by Bayer AG, polyisocyanate) 15 anchor parts were dissolved in a mixed solution of [methyl glycol acetate: butyl acetate: ethyl acetate: toluene] and applied to the same substrate used in Example 1. After drying at room temperature, a urethane paint was applied and dried and cured at 90 qo for 8 minutes to produce an automobile weather strip.

Control example 6 "Beccosol J-534" (trade name: manufactured by Dainippon Ink and Chemicals, linseed oil-modified long oil alkyd resin) was dissolved in a mineral base, and cobalt naphthenate was added as a desiccant. was applied to the same base material as used in Example 1, and after drying at room temperature, a urethane paint was applied and dried and cured at 90 qo for 8 minutes to produce a weather strip for an automobile.

Control example 7 80 parts of "Beccosol J-524" (trade name: manufactured by Dainippon Ink and Chemicals, linseed oil-modified short oil alkyd resin), "Super Beckamin J-820" (trade name: manufactured by Dainippon Ink and Chemicals, butyl A mixture of 20 parts of melamine resin) mixed and dissolved in xylene was applied to the same substrate as used in Example 1, dried at 120°C for 30 minutes, then coated with urethane paint, and heated at 90qo for 8 minutes. Control Example 8: 99 parts of "Acryloid C-110V" (product name: thermoplastic acrylic resin, manufactured by Rohm & Ha, Inc.) and 1 part of nitrocellulose were mixed with toluene. Using the dissolved one,
This was applied to the same base material as used in Example 1, and after drying at room temperature, a urethane paint was applied and dried and cured at 90° C. for 8 minutes to produce a weather strip for an automobile.

Comparative example 9 "Acrydik 47-712" (product name: Dainippon Ink & Chemicals, thermosetting acrylic resin) 8 Foundation part and "Su-
"Pervetsukamine 47-508" (trade name: manufactured by Dainippon Ink and Chemicals, butylated melamine resin) was dissolved in a mixed solvent [toluene:butyl acetate (2:1)], and this was used in Example 1. Apply to the same substrate as used and apply for 15 minutes.
After drying at 0℃ for 30 minutes, apply urethane paint and apply 90q
A weather strip for an automobile was manufactured by drying and curing for 8 minutes at a temperature of 100°C.

Table 1 shows the physical property test results of Examples 1 to 6 above.

From these results, the automotive weather strip of the present invention has excellent adhesion between the vulcanized rubber substrate and the urethane paint film layer, and has superior abrasion resistance and deformation followability compared to conventional products. I know that there is.

Table 1 *) No base material exposed.

All of Comparative Examples 1 to 9 had extremely poor abrasion resistance, adhesion, and followability, and could not be used as comparative controls.

Table 2 *) All numerical values indicate base material extrusion based on this number of frictions.

Claims (1)

[Claims] 1 Using ethylene-propylene vulcanized rubber as a base material, a functional hydrocarbon polymer containing a saturated aliphatic ring and a hydroxyl group as a functional group is applied as a primer, and then a urethane paint is coated on top of the primer. A weather strip for automobiles that is characterized by: