Composite stretchable film and method for forming same
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsJun Hatakeyama, Motoaki Iwabuchi, Joe Ikeda
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Abstract
The present invention is a composite stretchable film including: a surface film which is a cured product of a polyurethane 1 containing a copolymer of one or more of units “a1” to “a4” and silicone-pendant type urethane units “b1” and/or “b2” represented by the following general formula (1); and an inner film which is a cured product of a polyurethane 2 containing a unit “c” having polyether and urethane bonds represented by the following general formula (2), on which the surface film is laminated. The present invention provides a stretchable film that has excellent stretchability and strength, with the film surface having excellent water repellency, and a method for forming the same.
Claims8
A composite stretchable film comprising:
- a surface film which is a cured product of a polyurethane 1 containing a copolymer of a unit “a1” having polycarbonate and urethane bonds, and a silicone-pendant type urethane unit “b1” represented by the following general formula (1);
- and
- an inner film which is a cured product of a polyurethane 2 containing a unit “c” having polyether and urethane bonds represented by the following general formula (2), on which the surface film is laminated, wherein
- the composite stretchable film has a stretching property of 20 to 1000% in a tensile test regulated by JIS K 6251:
- wherein, R1 and R2 represent a pentamethylene group;
- R3 and R4 represent a butylene group;
- R5 represents a linear or branched alkylene group having 2 to 20 carbon atoms;
- R6, R7, and R8 represent a methyl group R9 represents a methyl group;
- R10 represents a hydrogen atom;
- R11 represents a single bond;
- R12 represents a hydrogen atom;
- X represents a linear alkylene group having 3 to 7 carbon atoms, and optionally containing an ether group;
- m, n, and p represent an integer of 1 to 200, and q, and r represent an integer of 0 to 20;
- and a1, b1, and c represent a ratio of the repeating unit satisfying inequalities 0<a1<1.0, and 0<b1<1.0 in the polyurethane 1.
A method for forming a composite stretchable film, comprising:
- applying a polyurethane 1 containing a copolymer of a unit “a1”, having polycarbonate and urethane bonds, and a silicone-pendant type urethane units “b 1” represented by the following general formula (1) on an inner film which is a cured product of a polyurethane 2 containing a unit “c” having polyether and urethane bonds represented by the following general formula (2);
- and
- curing the polyurethane 1 by heating and/or light exposure to form a surface film, wherein
- the composite stretchable film has a stretching property of 20 to 1000% in a tensile test regulated by JIS K 625:
- wherein, R1 and R2 represent a pentamethylene group;
- R3 and R4 represent a butylene group;
- R5 represents a linear or branched alkylene group having 2 to 20 carbon atoms;
- R6, R7, and R8 represent a methyl group;
- R9 represents a methyl group;
- R10 represents a hydrogen atom;
- R11 represents a single bond;
- R12 represents a hydrogen atom;
- X represents a linear alkylene group having 3 to 7 carbon atoms, and optionally containing an ether group;
- m, n, and p represent an integer of 1 to 200, and q, and r represent an integer of 0 to 20;
- and a1, b1, and c represent a ratio of the repeating unit satisfying inequalities 0<a1<1.0, and 0<b1<1.0 in the polyurethane 1.
Dependencies are inferred from the claim text.