Non-black rubber membranes
A roofing membrane comprising an olefinic rubber; and from about 20 to about 250 parts by weight of a silica filler per 100 parts by weight rubber; wherein the silica filler is chemically coupled to the olefinic rubber; and wherein the roofing membrane is non-black.
1. A roofing membrane comprising:
(i) a non-black element including silica dispersed within a crosslinked network of ethylene-propylene-diene rubber, where the silica is chemically coupled to the crosslinked network through a reaction with a coupling agent defined by the formula:
where R 8 is a divalent organic group or a bond, R 9 is a halogen atom or an alkoxy group, and each R 10 is independently a halogen, an alkoxy group, or a monovalent organic group, and where R 11 is a blocking group.
2. The membrane of claim 1 , where the non-black element includes at least 15 and less than 250 parts by weight silica per 100 parts by weight rubber.
3. The membrane of claim 1 , where the non-black element includes at least 20 and less than 200 parts by weight silica per 100 parts by weight rubber.
4. The membrane of claim 1 , where the non-black element further includes titanium dioxide.
5. The membrane of claim 4 , where the non-black element includes at least 20 and less than 90 parts by weight titanium dioxide per 100 parts by weight rubber.
6. The membrane of claim 1 , where the non-black element further includes a processing oil.
7. The membrane of claim 6 , where the non-black element includes at least 30 and less than 120 parts by weight processing oil per 100 parts by weight rubber.
8. The membrane of claim 7 , where the processing oil is a white oil.
9. The membrane of claim 6 , where the processing oil has a sulfur content of less than 0.5 weight percent and an unsaturation level of less than 3%.
10. The membrane of claim 1 , where the coupling agent is a thioester, a thiophosphinate, a thiophosphate, or a thiosulphonate.