Transparent membrane structures

Claim 1

A roofing fabric membrane structure composition comprising: (a) a base fabric material, (b) a base coating composition, applied to at least one surface of said base fabric material and (c) a silicone coating composition applied to at least one surface of said base fabric material already having thereon said base coating composition which is resistant to dirt pickup comprising: (i) a liquid vinyl chainstopped polysiloxane having the formula, ##STR8## where R and R 1 are monovalent hydrocarbon radicals free of aliphatic unsaturation with at least 50 mole percent of the R 1 groups being methyl, and where n has a value sufficient to provide a viscosity up to about 1,000 centipoise at 25° C.; (ii) a resinous organopolysiloxane copolymer comprising: (i) (R 2 ) 3 SiO 0 .5 units and SiO 2 units, (ii) (R 3 ) 3 SiO 0 .5 units, (R 3 ) 2 SiO units and SiO 2 units, or (iii) mixtures thereof, where R 2 and R 3 are selected from the group consisting of vinyl radicals and monovalent hydrocarbon radicals free of aliphatic unsaturation, where from about 1.5 to about 10 mole percent of the silicon atoms contain silicon-bonded vinyl groups, where the ratio of monofunctional units to tetrafunctional units is from about 0.5:1 to about 1:1, and the ratios of difunctional units to tetrafunctional units ranges up to about 0.1:1; (iii) a platinum or platinum containing catalyst; and (iv) a liquid organohydrogenpolysiloxane having the formula, ##EQU8## sufficient to provide from about 0.5 to about 1.0 silicon-bonded hydrogen atoms per silicon-bonded vinyl group, R is a monovalent hydrocarbon radical free of aliphatic unsaturation, a has a value of from about 1.0 to about 2.1, b has a value of from about 0.1 to about 1.0, and the sum of a and b is from about 2.0 to about 2.7, there being at least two silicon-bonded hydrogen atoms per molecule.

Claim 24

A method for making a roofing fabric membrane structure comprising the steps: I. applying to at least one side of a base fabric material, a base coating composition, II. applying to at least one side of said base fabric material coated with said base coating composition, a silicone coating composition which is resistant to dirt pickup comprising: (a) a liquid vinyl chainstopped polysiloxane having the formula, ##STR9## wherein R and R 1 are monovalent hydrocarbon radicals free of aliphatic unsaturation with at least 50 mole percent of the R 1 groups being methyl, and where n has a value sufficient to provide a viscosity up to about 1,000 centipoise at 25° C.; (b) a resinous organopolysiloxane copolymer comprising: (i) (R 2 ) 3 SiO 0 .5 units and SiO 2 units, (ii) (R 3 ) 3 SiO 0 .5 units, (R 3 ) 2 SiO units and SiO 2 units, or (iii) mixtures thereof, where R 2 and R 3 are selected from the group consisting of vinyl radicals and monovalent hydrocarbon radicals free of aliphatic unsaturation, where from about 1.5 to about 10 mole percent of the silicon atoms contain silicon-bonded vinyl groups, where the ratio of monofunctional units to tetra-functional units is from about 0.5:1 to about 1:1, and the ratio of difunctional units to tetrafunctional units ranges up to about 0.1:1; (c) a platinum or platinum containing catalyst; and (d) a liquid organohydrogenpolysiloxane having the formula, ##EQU9## sufficient to provide from about 0.5 to about 1.0 silicon-bonded hydrogen atoms per silicon-bonded vinyl group, R is a monovalent hydrocarbon radical free of aliphatic unsaturation, a has a value of from about 1.0 to about 2.1, b has a value of from about 0.1 to about 1.0, and the sum of a and b is from about 2.0 to about 2.7, there being at least two silicon-bonded hydrogen atoms per molecule. III. Curing said silicone coating composition which is resistant to dirt pickup to said base coating composition.

Claim 25

A method for making a roofing fabric membrane structure comprising the steps: I. applying to at least one side of a base fabric material, a base coating composition, II. applying to at least one side of said base fabric material coated with said base coating composition, a silicone coating composition which is resistant to dirt pickup comprising: (a) a liquid vinyl chainstopped polysiloxane having the formula, ##STR9## wherein R and R 1 are monovalent hydrocarbon radicals free of aliphatic unsaturation with at least 50 mole percent of the R 1 groups being methyl, and where n has a value sufficient to provide a viscosity up to about 1,000 centipoise at 25° C.; (b) a resinous organopolysiloxane copolymer comprising: (i) (R 2 ) 3 SiO 0 .5 units and SiO 2 units, (ii) (R 3 ) 3 SiO 0 .5 units, (R 3 ) 2 SiO units and SiO 2 units, or (iii) mixtures thereof, where R 2 and R 3 are selected from the group consisting of vinyl radicals and monovalent hydrocarbon radicals free of aliphatic unsaturation, where from about 1.5 to about 10 mole percent of the silicon atoms contain silicon-bonded vinyl groups, where the ratio of monofunctional units to tetra-functional units is from about 0.5:1 to about 1:1, and the ratio of difunctional units to tetrafunctional units ranges up to about 0.1:1; (c) a platinum or platinum containing catalyst; and (d) a liquid organohydrogenpolysiloxane having the formula, ##EQU9## sufficient to provide from about 0.5 to about 1.0 silicon-bonded hydrogen atoms per silicon-bonded vinyl group, R is a monovalent hydrocarbon radical free of aliphatic unsaturation, a has a value of from about 1.0 to about 2.1, b has a value of from about 0.1 to about 1.0, and the sum of a and b is from about 2.0 to about 2.7, there being at least two silicon-bonded hydrogen atoms per molecule. III. Curing said silicone coating composition which is resistant to dirt pickup to said base coating composition.