JPH0324370B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a weather strip used for sealing the body of an automobile, and in particular, as shown in FIG. This is suitable for a weather strip that is fixed to the rear door glass 2 to seal the mating area. <Prior Art> The above-mentioned weather strip has, for example, a cross section as shown in FIG. It consists of a support wall part 7 extending from the shoulder of the inside wall 6a, and a sliding lip part 8, which is bent from the free end of the support wall part 7 toward the outside of the car, and on which the front door glass 1 comes into sliding contact. There is a composition. In addition, the U-shaped insert 9 and the elbow-shaped insert 10 fixed to the top of the U-shaped insert 9 are located halfway up the U-shaped holding part 6 and the support wall 7, respectively.
is buried. Adhesive is applied to these inserts during weatherstrip molding. Water leaks easily at the part A of the weather strip 11 that comes into contact with the roof side rail weather strip 12 (see Figure 3). A compression seal member 5 made of sponge rubber and having a cross-sectional shape that fills the space surrounded by the support wall 7 and the sliding contact lip portion 8 is integrated. The main body of the weather strip 11 and the compression seal member 5
have traditionally been made of solid and sponge rubbers, SBR or SBR/NR blends, respectively. <Problems to be Solved by the Invention> However, weather strips made of these materials have high glass sliding resistance and do not have good abrasion resistance. At least the surface of each of the sealing members 10 on the sliding contact side of the glass is subjected to urethane coating treatment or halogen treatment (these treatments lead to an increase in the cost of the weather strip). If these surface treatments are not applied, or if the treated film disappears over time even if it is applied, the glass surface will become black and dirty due to the adhesion of fine rubber particles generated by wear, and furthermore, the glass surface will become dirty due to the adhesion of rubber particles generated by wear. The load during lifting and lowering was increased and abnormal noises were likely to occur. <Means for solving the problems> The main body of the weather strip of the present invention is made of solid rubber of a nitrile rubber (NBR)/polyvinyl chloride (PVC) polymer blend with a polyvinyl chloride content of 20 to 60 wt%. Furthermore, the above-mentioned problems are solved by integrating a compression sealing member made of sponge rubber of the above-mentioned polymer blend into the main body. <Explanation of structure> Here, if the PVC content of the polymer blend is less than 20 wt%, the structure of PVC sea phase-NBR island phase is considered to become NBR sea phase-PVC island phase,
PVC mixed effect - weather resistance, ozone resistance, oil resistance,
Improved chemical resistance and abrasion resistance, but on the other hand 60wt
%, the compression set increases, causing problems in the sealability over time of the glass sliding contact portion (sliding contact lip portion).
When used, this polymer blend contains inorganic fillers (carbon black, calcium carbonate), vulcanizing agents, vulcanization accelerators,
Add plasticizer, etc. In this formulation, it is desirable to use one or more of the specific lubricants shown in Table 1 in combination at 1 to 10 PHR, since this can further reduce the sliding resistance of the glass run portion. Here, the lubricant content is
If the amount is less than 1 PHR, the effect of adding the lubricant (sliding resistance reduction effect) will not be achieved, and if it exceeds 10 PHR, the effect of adding the lubricant will hardly increase and there is a risk of blooming and staining the glass. Furthermore, sponge rubber can be easily obtained by adding and mixing a blowing agent, which is usually incorporated into NBR, into the above polymer blend. As a foaming agent,
N,N'-dinitrosopentamethylenetetramine,
Examples include azodicarbonamide, P-toluenesulfoninyl hydrazide, P,P'-oxybisbenzenesulfonyl hydrazide (OBSH), and the like. In addition, the compression seal member (sponge rubber) is usually integrated into the weather strip body (solid rubber) by molding the main body by extrusion or injection, and then setting only the area where the compression seal member will be formed in a mold and then performing injection/transfer, etc. This is done by molding and vulcanizing and adhering at the same time. At this time, it is desirable from the viewpoint of adhesion to apply "NBR-based glue" to the part of the main body in advance. <Effects of the Invention> As described above, the weather strip of this invention has the following effects:
By forming the main body and the compression seal member with an NBR/PVC polymer blend, as shown in the examples and comparative examples below, the glass sliding contact area is improved compared to the case where the main body and the compression seal member are made of an SBR/NR polymer blend or SBR. Sliding resistance is extremely low, and it can be mounted on an actual vehicle without surface treatment to reduce sliding resistance. Therefore, as a matter of course, problems such as glass staining, increased sliding resistance, and deterioration of sealing performance, which conventionally occur when halogen treatment or urethane coating is not performed, do not occur. <Examples/Comparative Examples> Each test piece of the Examples/Comparative Examples was tested at 100 Kgf/cm ² × 170°C × using the following basic formulation with the polymer and lubricant as shown in Table 2.
It was obtained from a 2 mm thick solid rubber sheet that was vulcanized and molded for 10 minutes. Basic composition (unit: parts by weight); Polymer 100 Carbon black (HAF) 70 Plasticizer (phthalate ester) 90 Zinc white 5 Sulfur yellow 0.5 Vulcanization accelerator 4 Lubricant Variables The test methods for each property are as follows. He did as follows. (1) Sliding resistance; 2mmt seam (test piece) 2 as shown in Figure 4
Glass plate 22 (50mm x 100mm x 5mmt) on top of 1
A weight 23 (500 g or 100 g) was placed on the glass plate and the string 24 was used to pull it, and the average load (dynamic friction) when the glass plate was sliding was measured. (2) Ozone resistance: Evaluate crack occurrence time by dynamic ozone test (conditions: 0-20% elongation repetitions)
60cpm., ozone concentration 50pphm., ambient temperature 38
(℃) (3) Abrasion resistance; Akron abrasion test (BS903, Art A9) (conditions: load 6lb., angle 15°, rotation speed (drum side 33rpm. sample side 16rpm)) (4) Compression set; JISK6301 -10 (conditions; 100℃×
22hr., 25% compression) From the results shown in Table 2, the NBR/
Weatherstrips whose bodies are made of a PVC polymer blend not only have much lower sliding resistance than those made of NR/SBR or NBR, but also have good abrasion resistance and compression set. It can be seen that the strength and ozone resistance are also sufficient for practical use. Furthermore, sponge rubber (Example 11) having the following composition was vulcanized and bonded to solid rubber (Example 1), and both were pulled by hand to observe the location of breakage. The results are shown in Table 3. Sponge rubber formulation (unit: parts by weight) Polymer blend (same as Example 1) 100 Carbon black (HAF) 50 Plasticizer (phthalate ester) 30 Stearic acid 1 Zinc white 5 Sulfur 0.5 Vulcanization accelerator 1.5 Foaming agent ( OBSH) 3

【table】

【table】

[Table] Manufactured by East Co., Ltd., phenolic resin/chlorinated rubber
adhesive

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the general part of the weather strip to which this invention is applied, Fig. 2 is a cross-sectional view of the compressed seal member adhesion site, Fig. 3 is a model view of the weather strip in the attached state, and Fig. 4 is the sliding resistance. FIG. 2 is a model diagram showing a method for measuring . DESCRIPTION OF SYMBOLS 1...Front door glass, 2...Rear (door) glass, 5...Compression seal member, 6...U-shaped holding part, 7...Support wall part, 8...Sliding contact lip part, 11...Weather strip .

Claims (1)

[Scope of Claims] 1. A weather strip characterized in that the main body is formed of solid rubber of a nitrile rubber/polyvinyl chloride polymer blend having a polyvinyl chloride content of 20 to 60 wt%. 2 Compression sealing members made of sponge rubber of the above polymer blend are integrated into the main body made of solid rubber of nitrile rubber/polyvinyl chloride polymer blend with a polyvinyl chloride content of 20 to 60 wt% at required locations. A weather strip that is characterized by: