Patent ID: 9649828
Date: 2017-05-16
CPC Classifications: B32B,C08K,Y10T

Claim:
1. An intermediate film for laminated glass with a laminated structure of three or more layers, comprising: a first layer containing a polyvinyl acetal resin and an organic ester plasticizer, a second layer laminated on a first surface of the first layer, the second layer comprising a polyvinyl acetal resin and an organic ester plasticizer, and a third layer laminated on a second surface of the first layer that is opposite to the first surface of the first layer, the third layer comprising a polyvinyl acetal resin and an organic ester plasticizer; wherein a degree of acetylation of the polyvinyl acetal resin contained in the first layer exceeds 30 mol %, a degree of acetylation of the polyvinyl acetal resin contained in the second layer is 0.1 mol % or higher and 20 mol % or lower, and a degree of acetylation of the polyvinyl acetal resin contained in the third layer is 0.1 mol % or higher and 20 mol % or lower, wherein an amount of the organic ester plasticizer in the second layer is 15 parts by weight or more and 45 parts by weight or less for each 100 parts by weight of the polyvinyl acetal resin in the second layer, and an amount of the organic ester plasticizer in the third layer is 15 parts by weight or more and 45 parts by weight or less for each 100 parts by weight of the polyvinyl acetal resin in the third layer, wherein an amount of the organic ester plasticizer for each 100 parts by weight of the polyvinyl acetal resin in the second layer is lower than an amount of the organic ester plasticizer for each 100 parts by weight of the polyvinyl acetal resin in the first layer and an amount of the organic ester plasticizer for each 100 pans by weight of the polyvinyl acetal resin in the third layer is lower than an amount of the organic ester plasticizer for each 100 parts by weight of the polyvinyl acetal resin in the first layer, wherein an amount of the organic ester plasticizer in the first layer is 50 parts by weight or more for each 100 parts by weight of the polyvinyl acetal resin in the first layer, a hydroxy group content in the polyvinyl acetal resin contained in the first layer is lower than a hydroxy group content in the polyvinyl acetal resin contained in the second layer, and the difference between the hydroxy group content in the polyvinyl acetal resin contained in the first layer and the hydroxy group content in the polyvinyl acetal resin contained in the second layer is 9.2 mol % or smaller, wherein the polyvinyl acetal resin contained in the first layer contains a high-molecular-weight component with an absolute molecular weight of 1,000,000 or higher and a proportion of the high-molecular-weight component in the polyvinyl acetal resin contained in the first layer is 7.4% or higher, or the polyvinyl acetal resin contained in the first layer contains a high-molecular-weight component with a molecular weight in terms of polystyrene of 1,000,000 or higher and a proportion of the high-molecular-weight component with a molecular weight in terms of polystyrene in the polyvinyl acetal resin contained in the first layer is 9% or higher, and wherein a ratio (G′(Tg+80)/G′(Tg+30)) of an elastic modulus G′(Tg+80) at (Tg+80)° C. to an elastic modulus G′(Tg+30) at (Tg+30)° C. is 0.65 or higher, provided that a resin film containing 100 parts by weight of the polyvinyl acetal resin contained in the first layer and 60 parts by weight of triethylene glycol di-2-ethyl hexanoate (3GO) as a plasticizer is prepared and a viscoelasticity of the resin film is measured, and that Tg (° C.) represents a glass transition temperature of the resin film.