Liquid silicone rubber coating composition, curtain airbag, and its production method
A liquid silicone rubber coating composition exhibiting high adhesion for an airbag base fabric; a curtain airbag having a silicone rubber coating layer of the cured composition formed on at least one surface of the base fabric; and a method for producing such curtain airbag are provided. The composition comprises (A) an organopolysiloxane having at least 2 alkenyl groups bonded to the silicon atoms per molecule; (B) an organohydrogenpolysiloxane having at least 2 structural units represented by formula (1) per molecule, the structural units being linked by a non-siloxane structural unit not containing SiH group; (C) an addition catalyst; (E) an organosilicon compound having an epoxy group and an alkoxy group bonded to the silicon atom in the molecule; and (F) a titanium compound and/or a zirconium compound; and preferably (D) a fine powder silica having a specific surface area of at least 50 m 2 /g.
1. A liquid silicone rubber coating composition comprising
(A) 100 parts by weight of an organopolysiloxane having at least 2 alkenyl groups bonded to silicon atoms per molecule;
(B) an organohydrogenpolysiloxane comprising in the molecule at least 2 structural units represented by the following formula (1), which are connected together via a SiH-free non-siloxane structural unit,
wherein R 1 is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms and a is an integer of 2 or more, in an amount such that 1 to 10 hydrogen atoms bonded to silicon atoms in component (B) are present in relation to one alkenyl group bonded to a silicon atom in component (A);
(C) an addition reaction catalyst;
(D) 0 to 50 parts by weight of fine powder silica having a specific surface area of at least 50 m 2 /g;
(E) 0.1 to 10 parts by weight of an organosilicon compound having an epoxy group and an alkoxy group bonded to a silicon atom in the molecule; and
(F) 0.1 to 5 parts by weight of at least one member selected from a titanium compound and a zirconium compound.
2. The liquid silicone rubber coating composition according to claim 1 wherein the organohydrogenpolysiloxane of component (B) comprises the structure in which one or two or more structural units of the following formula (2) are connected:
wherein R 1 and a are as defined above, R 2 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 10 carbon atoms, R 3 is a substituted or unsubstituted divalent hydrocarbon group of at least 2 carbon atoms which may contain a silicon atom, and b is 1, 2 or 3.
3. The liquid silicone rubber coating composition according to claim 2 wherein R 3 in the organohydrogenpolysiloxane of formula (2) in component (B) is a straight chain, branched, or cyclic alkylene group having 2 to 20 carbon atoms which may contain a diorganosilylene group; or a divalent aromatic hydrocarbon group having 6 to 40 carbon atoms containing 1 to 4 phenylene skeletons which may contain a diorganosilylene group.
4. The liquid silicone rubber coating composition according to claim 1 wherein the organohydrogenpolysiloxane of component (B) is linear or branched and terminated with a (R 2 ) 3 SiO— and/or H(R 2 ) 2 SiO— group wherein R 2 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 10 carbon atoms.
5. The liquid silicone rubber coating composition according to claim 1 wherein component (F) is an organotitanium compound.
6. The liquid silicone rubber coating composition according to claim 5 wherein the organotitanium compound of component (F) is an organotitanate, an organotitanium chelate compound, or a combination thereof.
7. The liquid silicone rubber coating composition according to claim 1 wherein component (F) is an organozirconium compound.
8. The liquid silicone rubber coating composition according to claim 7 wherein the organozirconium compound of component (F) is an organozirconium ester, an organozirconium chelate compound, or a combination thereof.
9. The liquid silicone rubber coating composition according to claim 1 wherein the organohydrogenpolysiloxane of component (B) comprises the structure in which one or two or more structural units of the following formula (2)-1 are connected:
wherein R 1 is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms and not containing an aliphatic unsaturated bond, and a is an integer of 2 to 200, R 2 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms and not containing an aliphatic unsaturated bond, and R 3 is a linear, branched or cyclic alkylene group having 2 to 20 carbon atoms optionally containing a diorganosilylene group of —(R 2 ) 2 Si— structure, or a divalent arylene group or an alkylene-arylene group having 6 to 40 carbon atoms in which 1 to 4 phenylene skeletons are contained and optionally containing a diorganosilylene group of —(R 2 ) 2 Si— structure.
10. The liquid silicone rubber coating composition according to claim 9 wherein the organohydrogenpolysiloxane of component (B) comprises two or more structural units of the formula (2)-1 in which two of —R 3 — are connected to each other.
11. The liquid silicone rubber coating composition according to claim 9 wherein the organohydrogenpolysiloxane of component (B) is terminated with a (R 2 ) 3 SiO— and/or H(R 2 ) 2 SiO— group.
12. The liquid silicone rubber coating composition according to claim 10 wherein the organohydrogenpolysiloxane of component (B) is terminated with a (R 2 ) 3 SiO— and/or H(R 2 ) 2 SiO— group.
13. A method for producing a curtain airbag comprising the steps of coating the coating composition of claim 1 on at least one surface of a substrate comprising a fiber cloth, and curing the coating composition to form a silicone rubber coating layer of the cured product of the coating composition on at least one surface of the substrate.
14. A curtain airbag comprising
a substrate made of a fiber cloth, and
a silicone rubber coating layer formed by coating a liquid silicone rubber coating composition comprising
(A) 100 parts by weight of an organopolysiloxane having at least 2 alkenyl groups bonded to silicon atoms per molecule;
(B) an organohydrogenpolysiloxane comprising in the molecule at least 2 structural units represented by the following formula (1), which are connected together via a SiH-free non-siloxane structural unit,
wherein R 1 is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms and a is an integer of 2 or more, in an amount such that 1 to 10 hydrogen atoms bonded to silicon atoms in component (B) are present in relation to one alkenyl group bonded to a silicon atom in component (A);
(C) an addition reaction catalyst;
(D) 0 to 50 parts by weight of fine powder silica having a specific surface area of at least 50 m 2 /g;
(E) 0.1 to 10 parts by weight of an organosilicon compound having an epoxy group and an alkoxy group bonded to a silicon atom in the molecule; and
(F) 0.1 to 5 parts by weight of at least one member selected from a titanium compound and a zirconium compound
on at least one surface of the substrate and curing said composition.