SILICONE MEMBRANES

1 . A silicone membrane derived from a silicone composition comprising:

(i) 80 to 90 wt % of a silicone binder;

(ii) a plasticizer selected from: 5 to 15 wt % of a hydroxyl-terminated polysiloxane plasticizer; 5 to 15 wt % of a vinyl-terminated polysiloxane plasticizer; or a combination thereof;

(iii) 0.5 to 1.5 wt % of a reinforcing filler;

(iv) 1 to 8 wt % of a curative agent; and

(v) 1 to 25 wt % of a pigment;

wherein wt % is based on the total weight of the polymer solids.

2 . The silicone membrane of claim 1 , wherein the silicone binder is a polydimethylsiloxane.

3 . The silicone membrane of claim 1 , wherein hydroxyl-terminated polysiloxane plasticizer has formula:

wherein n is 0, 1, 2, 3, 4, 5, 6, 7, or 8.

4 . The silicone membrane of claim 1 , wherein the vinyl-terminated polysiloxane plasticizer has formula:

wherein m is 0, 1, 2, 3, 4, or 5.

5 . The silicone membrane of claim 1 , wherein the reinforcing filler is fumed silica.

6 . The silicone membrane of claim 1 , wherein the reinforcing filler is carbon black.

7 . The silicone membrane of claim 1 , wherein the curative agent is a peroxide.

8 . The silicone membrane of claim 7 , wherein the hydroxyl-terminated plasticizer and the vinyl-terminated plasticizer are present in a ratio of about 3 to 1.

9 . The silicone membrane of claim 1 , wherein the curative agent is a hydrosilation curative agent.

10 . The silicone membrane of claim 9 , wherein the hydrosilation curative agent has formula:

wherein x is 2, 3, 4, or 5; and y is 1, 2, 3, 4, or 5.

11 . The silicone membrane of claim 9 , wherein the hydroxyl-terminated plasticizer and the vinyl-terminated plasticizer are present in a ratio of about 1 to 1.

12 . The silicone membrane of claim 1 , wherein the composition further comprises an additive selected from a polyalkylene oxide compound having terminal functional groups selected from vinyl, allyl, acryloxy, methacryloxy, thiol, hydroxy, alkyl, alkoxysilyl, and silyl groups.

13 . The silicone membrane of claim 1 , wherein the pigment is a UV absorbing pigment, a UV reflecting pigment, an IR absorbing pigment, or a IR reflecting pigment.

14 . The silicone membrane of claim 1 , wherein the pigment is TiO 2 .

15 . The silicone membrane of any of claim 1 , wherein the composition further comprises a platinum catalyst.

16 . The silicone membrane of claim 15 , wherein the platinum catalyst is Karstedt's catalyst.

17 . A method of preparing a silicone roof membrane having improved durability comprising:

(a) adding a silicone mixture to a mixer;

(b) heating the silicone mixture to reduce the viscosity;

(c) adding the silicone mixture and a curative agent to an extruder assembly to form a silicone membrane;

(d) passing the silicone membrane through a calendar roll to press the silicone membrane into a desired thickness;

(e) adding a reinforcing scrim to reinforce the silicone membrane; and

(f) heating the silicone membrane in an oven.

18 . The method of claim 17 , wherein the silicone mixture comprises:

(i) 80 to 90 wt % of a silicone binder;

(ii) a plasticizer selected from: 5 to 15 wt % of a hydroxyl-terminated polysiloxane plasticizer;

5 to 15 wt % of a vinyl-terminated polysiloxane plasticizer; or a combination thereof;

(iii) 0.5 to 1.5 wt % of a reinforcing filler; and

(iv) 1 to 25 wt % of a pigment;

wherein wt % is based on the total weight of the polymer solids.

19 . The method of claim 17 , wherein the silicone mixture has a viscosity of greater than 1,000,000 cps.

20 .- 33 . (canceled)

34 . A method for covering a roof with a silicone membrane according to claim 1 , comprising:

(a) applying layers of the silicone membrane to a roof surface;

(b) overlapping adjacent edges of the layers;

(c) fastening the edges so that the overlap covers a fastener; and

(d) adhesively seaming the overlapped areas to seal and secure the membranes.