This disclosure is related to the field of polymer interlayers for multiple layer glass panels and multiple layer glass panels having at least one polymer interlayer sheet. Specifically, this disclosure is related to the field of polymer interlayers comprising multiple thermoplastic layers which resist the formation of optical defects.

This disclosure is related to the field of polymer interlayers for multiple layer glass panels and multiple layer glass panels having at least one polymer interlayer sheet. Specifically, this disclosure is related to the field of polymer interlayers comprising multiple thermoplastic layers which resist the formation of optical defects.

There is provided an interlayer film for laminated glass which is capable of enhancing sound insulating properties in the laminated glass obtained in the case of being used for constituting the laminated glass, and laminated glass prepared using the interlayer film for laminated glass. An interlayer film for laminated glass according to the present invention includes a modified polyvinyl acetate and a plasticizer, and the modified polyvinyl acetate has a vinyl acetate structural unit and a fatty acid vinyl ester structural unit; the laminated glass according to the present invention includes a first laminated glass constituent member, a second laminated glass constituent member, and an interlayer film sandwiched between the first and second laminated glass constituent members, and in the laminated glass according to the present invention, the interlayer film is the interlayer film for laminated glass described above.

The present invention provides multiple layer interlayers having a soft inner polymer layer and relatively stiff outer layers that can be laminated without unacceptable optical distortion and used in various multiple layer glass panel type applications. Multiple layer interlayers of the present invention have surface topography that is formed by controlling the melt fracture that occurs at the exposed surface of the interlayer, or individual layers of the multiple layer interlayer, during formation of the interlayer. By precisely controlling the surface topography of the interlayer, lamination of the interlayer with a rigid substrate does not lead to unacceptable optical distortion caused by the transfer of the surface topography through outer, stiffer layers into softer, internal layers of the interlayer.

The present invention aims to provide an intermediate film for laminated glass which, in the case of being used for constituting a laminated glass, enables to improve the sound-insulating property of the obtained laminated glass, and a laminated glass. The intermediate film 1 for laminated glass of the present invention comprises a first layer 2 which contains a polyvinyl acetal resin and a plasticizer, and the polyvinyl acetal resin and the first plasticizer are a polyvinyl acetal resin and a first plasticizer which have a cloud point of 5° C. or lower when the cloud point is measured using a solution prepared by dissolving 8 parts by weight of the polyvinyl acetal resin in 100 parts by weight of the first plasticizer; and the laminated glass 11 of the present invention comprises first and second components for laminated glass, and the intermediate film 1 for laminated glass sandwiched between the first and second components for laminated glass.

An interlayer film for laminated glass that can improve a sound insulation property of an obtained laminated glass when the interlayer film for laminated glass is used for configuring the laminated glass is provided. The interlayer film for laminated glass according to the present invention includes a first layer and a second layer laminated on a first surface of the first layer. The first layer includes a polyvinyl acetate resin and a plasticizer.

The present invention provides an intermediate film for laminated glass which can improve sound insulation. The intermediate film has a layered structure including at least two layers, comprising: a first layer containing a polyvinyl acetal resin and a plasticizer; and a second layer positioned on a first surface of the first layer. In a phase diagram of three values including a degree of acetalization, a degree of acetylation, and a hydroxyl group content of the polyvinyl acetal resin contained in the first layer, the values of the degree of acetalization, the degree of acetylation, and the hydroxyl group content each fall within a region surrounded by a line including four straight lines connecting first, second, third, and fourth coordinates, which respectively have a degree of acetalization:degree of acetylation:hydroxyl group content of 70 mol %:30 mol %:0 mol %, 34 mol %:30 mol %:36 mol %, 94 mol %:0 mol %:6 mol %, and 100 mol %:0 mol %:0 mol %.

An interlayer film for a laminated glass includes a thermoplastic resin and a plasticizer. The ratio of a high molecular weight component with an absolute molecular weight of 1000000 or more in the thermoplastic resin is 7.4% or higher, or the ratio of a high molecular weight component with a polystyrene-equivalent molecular weight of 1000000 or more in the thermoplastic resin is 9% or higher. A first multilayer interlayer film for a laminated glass includes an interlayer film for a laminated glass and an interlayer film for a laminated glass that contains a thermoplastic resin and a plasticizer, and is laminated on one face of the interlayer film for a laminated glass.

An interlayer film for laminated glass that can improve a sound insulation property of an obtained laminated glass when the interlayer film for laminated glass is used for configuring the laminated glass is provided. The interlayer film for laminated glass according to the present invention includes a first layer and a second layer laminated on a first surface of the first layer. The first layer includes a polyvinyl acetate resin and a plasticizer.

A method for producing a polyacrylic acid (salt)-based water absorbent resin, sequentially including the steps of: storing or producing acrylic acid; mixing acrylic acid containing a polymerization inhibitor with water, a crosslinking agent, and optionally, a basic composition, and/or neutralizing them, to prepare an aqueous monomer solution; polymerizing the aqueous monomer solution; drying an obtained water-containing gel-like crosslinked polymer; and optionally carrying out surface crosslinking, wherein the acrylic acid containing the polymerization inhibitor has a water content of not higher than 1,000 ppm (by mass; the same applies hereinafter), and/or the aqueous monomer solution has a formic acid content of 1 to 700 ppm, relative to the monomer.