Bonding sheet material for weather strip, weather strip, and method for producing same
AssigneeTokai Kogyo Kabushiki Kaisha
InventorsSatoshi Okamura, Yasuhiro Fukushima
Life of this patent
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Abstract
A bonding sheet material for a weather strip disclosed herein is a composition including at least EPDM, a cross-linking agent, and carbon black, and has a volume resistivity of 1.0×106 Ω·cm or more based on a double ring electrode method of JIS-K6271-1: 2015 where a test piece has a thickness of 2 mm. When the composition is placed in a mold and molded to press the composition at 50° C. under 100 Kgf/cm2 for 60 seconds whereby a molded article is produced, the molded article has a thickness change rate of 100% or less, the thickness change rate being represented by formula (1): Thickness change rate=((thickness of molded article after 30 minutes from releasing press−thickness of mold)/thickness of mold)×100.
Claims8
A bonding sheet material for a weather strip, the bonding sheet material being configured to bond opposite end portions of a weather strip material to each other, wherein
- the bonding sheet material is a composition including at least EPDM, a cross-linking agent, and carbon black,
- the bonding sheet material has a volume resistivity of 1.0×106 Ω·cm or more based on a double ring electrode method of JIS-K6271-1:
- 2015 where a test piece has a thickness of 2 mm,
- when the composition is placed in a mold and molded to press the composition at 50° C. under 100 Kgf/cm2 for 60 seconds whereby a molded article is produced, the molded article has a thickness change rate of 100% or less, the thickness change rate being represented by a formula (1),
- the formula (1):
- Thickness change rate=((thickness of molded article after 30 minutes from releasing press-thickness of mold)/thickness of mold)×100, and
- when a total amount of the composition configuring the bonding sheet material is defined as 100% by volume, a blending ratio of the carbon black is 11% or more by volume and 19% or less by volume.
A method for producing a weather strip including a main body portion having end portions and a bonding portion that bonds the opposite end portions of the main body portion to each other, the method comprising:
- preparing a weather strip material for forming the main body portion and a bonding sheet material for forming the bonding portion;
- and
- cross-linking the bonding sheet material by placing the bonding sheet material between the opposite end portions of the weather strip material, wherein
- the bonding sheet material satisfies all of the following conditions:
- a composition including at least EPDM, a cross-linking agent, and carbon black;
- a volume resistivity of 1.0×106 Ω·cm or more based on a double ring electrode method of JIS-K6271-1:
- 2015 where a test piece has a thickness of 2 mm;
- when the composition is placed in a mold and molded to press the composition at 50° C. under 100 Kgf/cm2 for 60 seconds whereby a molded article is produced, the molded article has a thickness change rate of 100% or less, the thickness change rate being represented by a formula (1);
- the formula (1):
- Thickness change rate=((thickness of molded article after 30 minutes from releasing press-thickness of mold)/thickness of mold)×100;
- and
- when a total amount of the composition configuring the bonding sheet material is defined as 100% by volume, a blending ratio of the carbon black is 11% or more by volume and 19% or less by volume.
Dependencies are inferred from the claim text.