JPH08175291A - Weather strip for automobile - Google Patents

Abstract

PURPOSE: To surely assure adhesion with sealer by forming compounds in an ethylene propylene system capable of being vulcanized using sulfur as vulcanizing agent out of the rubber compound of blended polymer in a specified range of a blending ratio. CONSTITUTION: Window frame rubber W is formed out of compounds in an ethylene propylene system capable of being vulcanized using sulfur as vulcanizing agent. The aforesaid compounds in an ethylene propylene rubber system is formed into the rubber compound of polymers blended in the blending ratios 40 to 98% polymer by weight in an ethylene propylene system: 2 to 60%, polymer by weight in an unsaturated nitrile conjugated diene copolymer rubber system: 0 to 30%, polymer by weight in a stylene conjugated diene copolymer. When the weather strip is actually mounted to an automobile, let sealer abut against a glass holding groove bottom section 11 and a seal lip forming area 13. By this constitution, practical adhesion with sealer can be assured even if any pretreatment such as hobbing and the like is not applied to estimated areas against which sealer abuts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather strip for an automobile, which is made of an EPDM compound and has a portion that comes into contact with a sealer when the vehicle is mounted on an actual vehicle.

[0002] Here, the weatherstrip means a front window, a fixed window glass part such as a quarter window, a door stop part such as a hood, a door and a sunroof in an automobile, and
It is attached to a sliding part such as a door and a door glass to shield the interior of the vehicle from wind, rain, dust, sound, cold and heat, etc. ("New Edition Automotive Engineering Handbook" Automotive Engineering Society, October 1, 1984).
Issued on the 0th, see Vol. 6, pages 1-39). That is, the so-called
It includes window frame rubber, door weather strips, glass runs, and the like.

A list of polymer / plasticizer abbreviations used in the present specification is shown below.

NBR ... Unsaturated nitrile / conjugated diene copolymer rubber, EPDM ... Sulfur vulcanizable terpolymer ethylene propylene rubber SBR ... Styrene / conjugated diene copolymer rubber, DOP ... Dioctyl phthalate.

[0005]

2. Description of the Related Art Here, a window frame rubber as shown in FIG. 1 will be described as an example, but the present invention is not limited to this.

A sealer is usually used to bond and seal the window frame rubber W to the window plate (glass plate) and the vehicle body. In this case, the window frame rubber is usually a sulfur-vulcanizable ternary EPD.
Extruded materials are used for the M formulation.

The EPDM and the sealer do not have good adhesion. This is because EPDM is a typical non-polar rubber, and the sealer is a polar polymer such as polyurethane in order to ensure adhesion with glass or metal.

For this reason, the parts to be contacted with the sealer of the window frame rubber after extrusion, that is, the glass gripping groove bottom part 1 and the seal lip forming part 3 are subjected to pre-treatment by buffing, degreasing treatment and primer application after extrusion. I was dealing with it by improving the adhesiveness.

[0009]

However, the portion that comes into contact with the sealer is the bottom portion of the glass gripping groove as described above,
It is difficult to mechanize the buffing because it has an uneven surface on which the lip portion is formed. Further, it is essential to apply a primer, which hinders cost reduction.

In view of the above, the present invention is a weather for automobiles which can secure a practical adhesiveness with a sealer after extruding without pretreatment such as buffing at a portion to be contacted with the sealer. Intended to provide strips.

[0011]

The present invention solves the above-mentioned problems by the following constitution.

A weather strip for an automobile, which is formed of a sulfur vulcanizable ethylene propylene rubber (EPDM) -based compound and has a portion that comes into contact with a sealer when mounted on an actual vehicle, wherein the EPDM-based compound is an EPDM-based polymer. A rubber compound of a blend polymer having a blending ratio of 40 to 98 wt% NBR polymer 2 to 60 wt% SBR polymer 0 to 30 wt%.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The means of the present invention will be described in detail below. In the following description, the unit of composition and the composition ratio are units of weight unless otherwise specified.

(1) As shown in FIG. 1, the weather strip for an automobile of this embodiment, that is, the window frame rubber W, is similar to the above.
A part formed of a sulfur vulcanizable EPDM compound and contacting the sealer when mounted on an actual vehicle (a part to be contacted with the sealer), that is, a glass gripping groove bottom part 11 and a seal lip forming part 1
Prerequisite is to have 3.

EPDM is ethylene, propylene in which a small amount of a non-conjugated diene such as ethylidene norbornene, cyclopentadiene and 1,4-hexadiene is added as a third component and copolymerized to introduce a double bond into a side chain. It can be vulcanized with sulfur.

The polymer is usually mixed with auxiliary materials such as a reinforcing filler (carbon black or white carbon), a plasticizer, a lubricant and a vulcanizing agent.

(2) In the above constitution, the following blended polymer blend is used as the EPDM blend.

The blend polymer is an EPDM polymer 40 to 98% (preferably 70 to 40%).
90%) NBR polymer 2 to 60% (preferably 5 to 5)
20%) SBR polymer 0 to 30% (preferably 5 to 5)
20%) and the NBR polymer is an unsaturated nitrile-conjugated diene-acrylic acid ester terpolymer.

Here, if the EPDM polymer is less than 40%, it is difficult to ensure the ozone resistance of the main rubber, and if it exceeds 98%, it is difficult to secure the adhesiveness of the main rubber with the sealer.

If the NBR type polymer is less than 2%,
It is difficult to secure the adhesiveness between the main body rubber and the sealer. If it exceeds 60%, it is difficult to ensure the ozone resistance of the main body rubber and it is difficult to secure the vulcanized adhesiveness of the main body rubber to the main body.

The SBR-based polymer has the function of increasing the miscibility of the NBR-based polymer with the EPDM-based polymer. It is presumed that the SBR polymer has an intermediate polarity between the EPDM polymer and the NBR polymer. SBR polymer is 3
If it exceeds 0%, the vulcanized physical properties of the main rubber are likely to deteriorate.
SBR-based polymer 5% to improve the miscibility
It is desirable to mix the above.

The NBR polymer may be a general-purpose unsaturated nitrile-conjugated diene copolymer rubber, but it is preferable to use an unsaturated nitrile-conjugated diene-acrylic ester terpolymer rubber.

Here, as the unsaturated nitrile, acrylonitrile, methacrylonitrile, etc .; as the conjugated diene, butadiene, isoprene, etc .; as the acrylic ester, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n- Butyl acrylate, isobutyl acrylate, n-pentyl acrylate, isopentyl acrylate (preferably alkyl alcohol ester having 2 to 5 carbon atoms) and the like;

In particular, acrylonitrile-butadiene-n
-Butyl acrylate is preferred. And, their monomer composition is usually acrylonitrile: 10 to 40%
Butadiene: 20-50%, n-butyl acrylate:
25 to 55%.

The SBR polymer may be a general-purpose styrene / conjugated diene copolymer (SBR), but hydrogenated products thereof are preferable because they increase the sealer adhesion and primer adhesion resistance.

The hydrogenation rate is usually 90 to 100%,
Desirably, it is 95 to 100%.

The polymer composition of this conjugated diene rubber before hydrogenation has a styrene content of 10 to 40% (preferably 20).
˜30%), and conjugated diene content: 60 to 90% (desirably 70 to 80%). The conjugated diene used in the NBR rubber can be used.

The embodiment of this conjugated diene rubber is
If A: styrene polymer, B: styrene-butadiene random copolymer or butadiene polymer having many vinyl bonds, and C: butadiene polymer having many cis-1,4 bonds, AB, ABA, ABC, etc. ABA is particularly preferable.

The above-mentioned blended polymer usually contains a reinforcing filler (carbon black or white carbon),
Plasticizers, lubricants, vulcanizing agents and, if necessary, auxiliary materials such as colorants are mixed and kneaded with a general-purpose kneader such as a roll or a Banbury mixer to obtain the rubber composition for weatherstrip of the present invention.

Then, the window frame rubber (weather strip) is extruded and vulcanized by an extruder. Vulcanization is, for example,
A microwave heating device and a hot air vulcanization device are used. The vulcanization conditions are usually 200 ° C. × 3 to 10 minutes. (3) The window frame rubber W manufactured in this manner is, as in the conventional case, located at the planned sealer contact portion, that is, the glass gripping groove bottom portion 1
1 and a seal lip S on the seal lip forming portion 13,
As shown in FIG. 2, it is mounted on an actual vehicle. In the figure, 17
Is a vehicle body flange, and 19 is a windshield glass.

At this time, since the main body rubber is formed of a specific EPDM compound having good adhesiveness with the sealer, a sufficient adhesive strength with the sealer S can be expected, and buffing and Practical adhesive strength (1.5 kgf / 10 mm) can be obtained without pretreatment such as degreasing treatment and primer coating.

Further, when the primer coating is applied, a larger adhesive strength can be obtained between the main rubber and the sealer. In particular, when the EPDM primer is pre-coated prior to the application of general-purpose primer (in the case of urethane-based sealer, isocyanate-based primer), 100% adherend destruction (sealer destruction)
The maximum adhesive strength of is obtained.

As a general-purpose primer, "9002T"
(Made by Sunstar Giken Co., Ltd.) isocyanate type,
As a primer for EPDM, "K500" (manufactured by Sumitomo 3M), "SL8861" (manufactured by Sakai Kagaku) / [dismodule RFE] (manufactured by Bayer) = 100 /
4 can be preferably used. Etc. can be mentioned.

The sealer applicable to the present invention is not particularly limited, but urethane type ones such as "CSI450" (manufactured by Cementine) can be preferably used.

[0035]

As described above, the weather strip of the present invention is a weather strip having a portion that comes into contact with the sealer when mounted on an actual vehicle.
The following actions and effects are obtained by extruding an EPDM rubber compound of a blend polymer having a blend ratio of wt%, NBR polymer: 2 to 60 wt%, SBR polymer: 0 to 30 wt%. Play.

After extrusion molding on the sealer contacting part, buffing
Adhesion to the sealer is good due to the presence of the rubber of the main body, even without pretreatment such as degreasing treatment and primer treatment. Therefore, the weather strip of the present invention does not require the buffing / degreasing process after extrusion molding before being mounted on an actual vehicle, and the productivity is improved.

[0037]

[Test Example] Hereinafter, an example carried out to confirm the effect of the present invention will be described.

A. Extruder (Specification: Cylinder diameter 60 mmφ,
Using the compression ratio of 1.5) in the basic formulation of Table 1,
Using a rubber material of each compounding formulation shown in Tables 2 to 4 as a blend polymer, an extrudate with a width of 10 mm and a thickness of 3 mm was extruded (condition; extrusion speed: 5 m / min), and then hot air vulcanization (2
Each test piece was prepared by cutting the extrudate into a length of 100 mm and heating at 20 ° C. for 15 minutes. In addition, Comparative Examples 4 and 5 are shown in Table 5
A test piece was prepared in the same manner using the compounded rubber shown in.

The following items were tested for each test piece.

(1) Tensile strength test: Performed according to JIS K 6301.

(2) Adhesion test against sealer: A primer (primer (“9002T” manufactured by Sunstar Giken Co., Ltd.) was applied to each test piece.
Or in addition to it, EPDM primer (“K500”)
Sumitomo 3M Co., Ltd.)) or not, and after forming a sealer layer with a urethane sealer (“CS1450” manufactured by Cementine Co., Ltd.) to a film thickness of 5 mm, 50 ° C. ×
After drying and curing the sealer under the condition of 93% RH x 5 days,
A 180 ° peel test was performed at a pulling speed of 50 mm / min.

(3) Ozone resistance test: Performed according to JIS K 6301. Conditions are ozone concentration: 50pphm, test temperature: 40
C., elongation: 50%, observation time: 300 hours. B. Test results: From Table 2 showing the test results,
It can be seen that good properties are exhibited in all of the tensile strength, the sealer adhesion, and the ozone resistance. In particular, when the NBR is an unsaturated nitrile-conjugated diene-acrylic acid ester terpolymer (modified NBR), a general-purpose NBR
In comparison with the above, the sealer adhesion resistance in the primerless state is excellent (see Examples 1 and 3), and when hydrogenated SBR is used as the SBR, the adhesion to the sealer increases. See Examples 4 and 9). Furthermore, when the EPDM primer coating is applied prior to the primer coating,
It can be seen that the maximum strength of 100% adherend (sealer) destruction is obtained (Example 5).

Comparative Example 1 in which NBR is not blended
No. 2 has almost no adhesion to the sealer regardless of the presence / absence of primer application, SBR has an excessive blend ratio, Comparative Example 3 has poor vulcanized rubber strength, and NBR has an excessive blend ratio. In each case, the ozone resistance is inferior. Furthermore, conventional non-blended EPDM
It can be seen that Comparative Examples 6 and 7 in which the primer coating was used were inferior to the sealer adhesion in each of the cases where the rough surface was processed and the rough surface was processed, as compared with the respective examples where the primer was applied. .

Note that * 1) to * 6) in Tables 2 to 4 are as follows.

* 1) "JSR EP65": EPDM manufactured by Japan Synthetic Rubber Co., Ltd .; ethylene content 60%, third component ethylidene norbornene, iodine value 29.0.

* 2) "JSR N250S": general-purpose NBR manufactured by Japan Synthetic Rubber Co .; acrylonitrile content 20%.

* 3) "JSR N250S": acrylonitrile-butadiene-n-butyl acrylate manufactured by Japan Synthetic Rubber Co .; acrylonitrile content 25%, n-butyl acrylate content 40%.

* 4) "JSR DINARON 132
0P ": hydrogenated SBR manufactured by Japan Synthetic Rubber Co., Ltd., styrene content 1
0%, hydrogenation rate 99%, * 5) "JSR 1502": General-purpose S manufactured by Japan Synthetic Rubber Co., Ltd.
BR, styrene content 23.5%.

* 6) EPDM prior to application of general-purpose primer
Apply primer for use.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

[Table 4]

[0054]

[Table 5]

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a window frame rubber (weather strip) to which the present invention is applied.

FIG. 2 is a sectional view of the window frame rubber of FIG. 1 mounted on an actual vehicle.

[Explanation of symbols]

 11 ... Glass grip groove bottom (schera abutting site) 13 ... seal lip forming site (sealer abutment site) 15 ... main body rubber 17 ... window frame rubber main body S ... sealer

Claims (3)

[Claims] 1. A weather strip for an automobile, which is formed of a sulfur vulcanizable ethylene propylene rubber (EPDM) -based compound and has a portion that comes into contact with a sealer when mounted on an actual vehicle, wherein the EPDM-based compound is EPDM-based compound. Polymer-based polymer 40-98 wt% NBR-based polymer 2-60 wt% SBR-based polymer 0-30 wt% A blended polymer rubber blend having a blend ratio of 0. 2. The weather strip for automobiles according to claim 1, wherein the NBR-based polymer is a rubber compound of a blend polymer which is an unsaturated nitrile-conjugated diene-acrylic acid ester terpolymer. 3. The weatherstrip for an automobile according to claim 1, wherein a primer layer is interposed between the weatherstrip body and the sealer.