Interlayer for laminated glass, and laminated glass

An interlayer film for laminated glass having a three or more layer structure, the interlayer film for laminated glass comprising:

• a first layer;
• a second layer layered on a first surface of the first layer;
• and
• a third layer layered on a second surface opposite to the first surface of the first layer,
• the first layer containing a thermoplastic resin and a plasticizer,
• the second layer containing a thermoplastic resin and a plasticizer,
• the third layer containing a thermoplastic resin and a plasticizer,
• the thermoplastic resin contained in each of the first layer, the second layer, and the third layer being at least one selected from the group consisting of a polyvinyl acetal resin, an ethylene-vinyl acetate copolymer resin, an ethylene-acrylic acid copolymer resin, a polyurethane resin and a polyvinyl alcohol resin,
• the plasticizer contained in each of the first layer, the second layer, and the third layer being at least one selected from the group consisting of an organic ester plasticizer, an organic phosphate plasticizer and an organic phosphite plasticizer,
• a content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer being 35 parts by weight or less, and
• when an absolute value of a difference between a cloud point measured by using a liquid prepared by dissolving 8 parts by weight of the thermoplastic resin in the first layer in 100 parts by weight of the plasticizer in the first layer and a cloud point measured by using a liquid prepared by dissolving 8 parts by weight of the thermoplastic resin in the second layer in 100 parts by weight of the plasticizer in the second layer being represented by Xa, and a content based on parts by weight of an entire plasticizer in the interlayer film for laminated glass relative to 100 parts by weight of an entire thermoplastic resin in the interlayer film for laminated glass being represented by Z, the interlayer film satisfying at least one of a first constitution and a second constitution below:
• First constitution:
• Xa≤115 and Z≤−0.16Xa+59, and
• Second constitution:
• the thermoplastic resin in the first layer is a polyvinyl acetal resin, and when an acetylation degree based on a mole percent of the polyvinyl acetal resin in the first layer is represented by Y, Y≥2 and Z≤−0.16Xa−0.2Y+59,
• wherein the content Z of the plasticizer is calculated as [{X1 (mg)×P1+X2 (mg)×P2+X3 (mg)×P3}/{X1 (mg)×R1+X2 (mg)×R2+X3 (mg)×R3}], wherein
• X1 is a weight of the first layer,
• R1 is a content of the thermoplastic resin which accounts for the total of the thermoplastic resin and the plasticizer in the first layer,
• P1 is a content of the plasticizer which accounts for the total of the thermoplastic resin and the plasticizer in the first layer,
• X2 is a weight of the second layer,
• R2 is a content of the thermoplastic resin which accounts for the total of the thermoplastic resin and the plasticizer in the second layer,
• P2 is a content of the plasticizer which accounts for the total of the thermoplastic resin and the plasticizer in the second layer,
• X3 is a weight of the third layer,
• R3 is a content of the thermoplastic resin which accounts for the total of the thermoplastic resin and the plasticizer in the third layer, and
• P3 is a content of the plasticizer which accounts for the total of the thermoplastic resin and the plasticizer in the third layer, and
• wherein, when the interlayer film for laminated glass has more than the three-layer structure, the content Z of the plasticizer in the interlayer film is measured as in the case where the interlayer film has the three-layer structure.