国产夫妻精品视频久久久|久久国产精品久久精品国产美女|亚洲第一国产毛片久久久|亚洲国产成人av毛片国产

Silicone refers to a compound containing a Si-C key, and at least one organic group is directly connected to the silicon atom. Because the molecular chain stabilization of the silicone is firm, it is a inert body, so the performance is very stable, with high low temperature Excellent performance, still do not change, harden or crack at -60 ° C, no soft, degradation at high temperatures at 220 ° C; chemical solvent, ultraviolet, better weather resistance, not yellow, this is the bonding of other materials Adventures cannot be superior.