▎ 摘　　要

NOVELTY - A composite silicone sealant comprises component (A) and component (B). The component (A) comprises base gum, nano-material powder, filler and silane coupling agent. The component (B) comprises cross-linking agent, plasticizer and catalyst. The base gum comprises hydroxyl-terminated polydimethylsiloxane, hydroxyl-terminated polymethylphenylsiloxane, alkoxy-terminated polydimethylsiloxane, vinyl-terminated polydimethylsiloxane or allyl silyl-terminated polydimethylsiloxane. The nano-material powder comprises 5-10 layers of graphene oxide, modified graphene or modified white graphene. USE - Composite silicone sealant used for two-way sealing of insulating glass. ADVANTAGE - The composite silicone sealant has excellent high-gas barrier properties and mechanical strength, and has excellent compatibility with butyl rubber and processing performance. The composite silicone sealant is environmentally-friendly. DETAILED DESCRIPTION - A composite silicone sealant comprises component (A) and component (B). The component (A) comprises 100 parts mass base gum, 0.01-10 parts mass nano-material powder, 40-100 parts mass filler and 5-10 parts mass silane coupling agent. The component (B) comprises 10-20 parts mass cross-linking agent, 10-30 parts mass plasticizer and 0.1-2 parts mass catalyst. The weight ratio of component (A) to the component (B) is 10-13:1. The base gum comprises hydroxyl-terminated polydimethylsiloxane, hydroxyl-terminated polymethylphenylsiloxane, alkoxy-terminated polydimethylsiloxane, vinyl-terminated polydimethylsiloxane or allyl silyl-terminated polydimethylsiloxane. The nano-material powder comprises 5-10 layers of graphene oxide, modified graphene or modified white graphene. An INDEPENDENT CLAIM is included for method for producing composite silicone sealant with high-gas barrier properties, which involves (i) selecting nano-material powder, 5-10 layers of graphene oxide, modified graphene or modified white graphene obtained by the treatment with the surfactant, (ii) adding base gum, nano-material powder, filler and silane coupling agent, stirring evenly in a kneader or a planetary mixer and obtaining component (A), (iii) adding crosslinking agent, plasticizer and catalyst to the planetary mixer and stirring at a negative pressure of -0.06-0.099 MPa in room temperature to obtain component (B), (iv) mixing the component (A) and component (B) in the prescribed proportions to obtain the silicone sealant.