Method for imparting releasability to a substrate surface

Claim 1

A method for imparting releasability to the surface of a plastic film or paper as the substrate which comprises the steps of: (a) coating the substrate surface with an organopolysiloxane composition comprising (1) an organopolysiloxane having, in a molecule, at least two aliphatically unsaturated hydrocarbon groups bonded to the silicon atoms, (2) an organohydrogenpolysiloxane represented by the general unit formula (RSiO.sub.1.5).sub.m (R.sub.2 HSiO.sub.0.5).sub.n, in which each R is, independently from the others, a substituted or unsubstituted monovalent hydrocarbon group free fom aliphatic unsaturation and the subscripts m and n are each a positive integer with the proviso that the ratio of n/m is larger than 0.2 but smaller than 1.5, in such an amount that from 0.5 to 5 moles of the hydrogen atoms directly bonded to the silicon atoms are provided per mole of the aliphatically unsaturated hydrocarbon groups in the organopolysiloxane as the component (1), and (3) a catalytic amount of a platinum compound; and (b) subjecting the plastic film or paper coated with the organopolysiloxane composition to a heat treatment or to irradiation with ultraviolet light.

Claim 2

A method for imparting releasability to the surface of a plastic film or paper as the substrate which comprises the steps of: (a) coating the substrate surface with an organopolysiloxane composition comprising (1) an organopolysiloxane having, in a molecule, at least two aliphatically unsaturated hydrocarbon groups bonded to the silicon atoms, (2) an organohydrogenpolysiloxane represented by the general unit formula (RSiO.sub.1.5).sub.m (R.sub.2 HSiO.sub.0.5).sub.n, in which each R is, independently from the others, a substituted or unsubstituted monovalent hydrocarbon group free fom aliphatic unsaturation and the subscripts m and n are each a positive integer with the proviso that the ratio of n/m is larger than 0.2 but smaller than 1.5, in such an amount that from 0.5 to 5 moles of the hydrogen atoms directly bonded to the silicon atoms are provided per mole of the aliphatically unsaturated hydrocarbon groups in the organopolysiloxane as the component (1), and (3) a catalytic amount of a platinum compound; and (b) subjecting the plastic film or paper coated with the organopolysiloxane composition to a heat treatment or to irradiation with ultraviolet light.

Claim 3

A method for imparting releasability to the surface of a plastic film or paper as the substrate which comprises the steps of: (a) coating the substrate surface with an organopolysiloxane composition comprising (1) an organopolysiloxane having, in a molecule, at least two aliphatically unsaturated hydrocarbon groups bonded to the silicon atoms, (2) a combination of organohydrogenpolysiloxane in such an amount that from 0.5 to 5 moles of the hydrogen atoms directly bonded to the silicon atoms are provided per mole of the aliphatically unsaturated hydrocarbon groups in the organopolysiloxane as the component (1), composed of (2a) a first organohydrogenpolysiloxane represented by the general unit formula (RSiO.sub.1.5).sub.m (R.sub.2 HSiO.sub.0.5).sub.n, in which each R is, independently from the others, a substituted or unsubstituted monovalent hydrocarbon group free from aliphatic unsaturation and the subscripts m and n are each a positive integer with the proviso that the ratio of n/m is larger than 0.1 but smaller than 3.0, and (2b) a second organohydrogenpolysiloxane represented by the general formula R.sup.1 --SiR.sub.2 --O--SiHR--O).sub.p (SiR.sub.2 --O).sub.q SiR.sub.2 --R.sup.1, in which R has the same meaning as defined above, R 1 has the same meaning as R or is a hydrogen atom, the subscript p is a positive integer not exceeding 1,000 and the subscript q is zero or a positive integer not exceeding 1,000, in such a proportion that the molar ratio of the silicon-bonded hydrogen atoms provided by the second organohydrogenpolysiloxane to the silicon-bonded hydrogen atoms provided by the first and the second organohydrogenpolysiloxanes is in the range fro 9:10 to 1:10, and (3) a catalytic amount of a platinum compound; and (b) subjecting the plastic film or paper coated with the organopolysiloxane composition to a heat treatment or to irradiation with ultraviolet light.

Claim 4

A method for imparting releasability to the surface of a plastic film or paper as the substrate which comprises the steps of: (a) coating the substrate surface with an organopolysiloxane composition comprising (1) an organopolysiloxane having, in a molecule, at least two aliphatically unsaturated hydrocarbon groups bonded to the silicon atoms, (2) a combination of organohydrogenpolysiloxane in such an amount that from 0.5 to 5 moles of the hydrogen atoms directly bonded to the silicon atoms are provided per mole of the aliphatically unsaturated hydrocarbon groups in the organopolysiloxane as the component (1), composed of (2a) a first organohydrogenpolysiloxane represented by the general unit formula (RSiO.sub.1.5).sub.m (R.sub.2 HSiO.sub.0.5).sub.n, in which each R is, independently from the others, a substituted or unsubstituted monovalent hydrocarbon group free from aliphatic unsaturation and the subscripts m and n are each a positive integer with the proviso that the ratio of n/m is larger than 0.1 but smaller than 3.0, and (2b) a second organohydrogenpolysiloxane represented by the general formula R.sup.1 --SiR.sub.2 --O--SiHR--O).sub.p (SiR.sub.2 --O).sub.q SiR.sub.2 --R.sup.1, in which R has the same meaning as defined above, R 1 has the same meaning as R or is a hydrogen atom, the subscript p is a positive integer not exceeding 1,000 and the subscript q is zero or a positive integer not exceeding 1,000, in such a proportion that the molar ratio of the silicon-bonded hydrogen atoms provided by the second organohydrogenpolysiloxane to the silicon-bonded hydrogen atoms provided by the first and the second organohydrogenpolysiloxanes is in the range fro 9:10 to 1:10, and (3) a catalytic amount of a platinum compound; and (b) subjecting the plastic film or paper coated with the organopolysiloxane composition to a heat treatment or to irradiation with ultraviolet light.