There is provided an interlayer film for laminated glass with which the flexural rigidity of laminated glass can be enhanced and the sound insulating properties of laminated glass can be enhanced. The interlayer film for laminated glass according to the present invention includes first, second, and third layers containing a polyvinyl acetal resin and a plasticizer, the content of the hydroxyl group of the polyvinyl acetal resin in the first layer is lower than the content of the hydroxyl group of the polyvinyl acetal resin in each of the second and third layers, when absolute values of a difference between the content of the hydroxyl group of the polyvinyl acetal resin in the second and third layers and the content of the hydroxyl group of the polyvinyl acetal resin in the first layer are defined as XA and XB, respectively, each of the absolute values XA and XB is 9% by mole or more and 11% by mole or less, and when a content of the plasticizer in the interlayer film relative to 100 parts by weight of the polyvinyl acetal resin in the interlayer film is defined as Y, XA, XB, and Y satisfy the equations of Y≤−1.68XA+56 and Y≤−1.68XB+56.

Provided is an interlayer film for laminated glass with which double images in laminated glass can be significantly suppressed. An interlayer film for laminated glass according to the present invention has one end, and the other end having a larger thickness than the one end, and has a region for display corresponding to a display region of a head-up display, and when points are selected at 2 mm intervals while taking a position of 2 cm from an end part of the one end side toward the other end of the region for display as a start point, and a position of 2 cm from an end part of the other end side toward the one end of the region for display as an end point, and first partial wedge angles are calculated in respective first partial regions of 40 mm in the direction connecting the one end and the other end centered at respective selected points, an absolute value of difference between the maximum value among all the first partial wedge angle values and the minimum value among all the first partial wedge angle values is 0.4 mrad or less, and the interlayer film as a whole has a wedge angle of 0.1 mrad or more.

Provided is an interlayer film for laminated glass with which change in partial wedge angle can be suppressed at the time of preparation of laminated glass, and double images can be suppressed in the laminated glass. The interlayer film for laminated glass according to the present invention has one end, and the other end having a larger thickness than the one end; the thickness of the interlayer film does not increase evenly from the one end toward the other end, and an average rate of change in partial wedge angle determined by the following formula (X) is 10% or less when an interlayer film finally pressure-bonded is obtained through a predetermined process using the interlayer film for laminated glass as an interlayer film before pressure-bonding, and each partial wedge angle is measured in each of the interlayer film before pressure-bonding and the interlayer film after final pressure-bonding. Rate of change in partial wedge angle (%)=|(Partial wedge angle of interlayer film after final pressure-bonding−Partial wedge angle of interlayer film before pressure-bonding)/(Partial wedge angle of interlayer film before pressure-bonding)|×100 . . . Formula (X)

An interlayer film for laminated glass of the present invention comprises: a resin; a colorant; and a heat shielding material, wherein the interlayer film for laminated glass has a colored region in which a visible light transmittance of a laminated glass is 6% or more and 50% or less, provided that the laminated glass is produced using two clear glass plates having a visible light transmittance of 90.4% in conformity with JIS R 3202: 2011.

A polymeric film comprising a polyvinyl acetal resin a plasticizer and a blending agent containing an aliphatic ring and at least one hydroxyl group are disclosed. A laminate is also described where the polymeric film is used as the interlayer between two transparent materials such as glass. The laminate made using the polymeric film has excellent optical and impact resistance properties.

The method of producing a polyvinyl butyral resin of the present disclosure enable manufacture of a film of which yellow index is low and durability is enhanced, when a film for lamination is manufactured, by advancing acetalization reaction of a polyvinyl alcohol resin and a butanal in the presence of a hydroxy butyric acid.

A polymer film comprising polyvinylacetal and a laminated glass manufactured using the same are provided. At least one surface of the polymer film has a void volume (Vv) value at a material ratio of 10% ranging from 3 m.sup.3/m.sup.2 to 34.3 m.sup.3/m.sup.2, wherein the void volume (Vv) and material ratio are defined in accordance with ISO 25178-2:2012.

There is provided an interlayer film for laminated glass with which the production efficiency of laminated glass can be heightened. The interlayer film for laminated glass according to the present invention is an interlayer film for laminated glass having a one-layer structure or a two or more-layer structure and includes a first layer containing a thermoplastic resin, the softening point of the first layer is 60 C. or more, the interlayer film has an MD direction and a TD direction, and with regard to thermal shrinkage ratios obtained when the first inside portion, the second inside portion and the central portion are heated for 20 minutes at 140 C. respectively, all of the thermal shrinkage ratio MD1MAX, the thermal shrinkage ratio MD2MAX and the thermal shrinkage ratio MD3MAX are 45% or less.

There is provided an interlayer film for laminated glass with which the production efficiency of laminated glass can be heightened. The interlayer film for laminated glass according to the present invention is an interlayer film for laminated glass having a one-layer structure or a two or more-layer structure and includes a first layer containing a thermoplastic resin, the softening point of the first layer is 60 C. or more, the interlayer film has an MD direction and a TD direction, and with regard to thermal shrinkage ratios obtained when the first inside portion, the second inside portion and the central portion are heated for 2 minutes at 80 C. respectively, all of the thermal shrinkage ratio MD1MAX, the thermal shrinkage ratio MD2MAX and the thermal shrinkage ratio MD3MAX are 18% or less.

Resin compositions, layers, and interlayers comprising a poly(vinyl acetal) resin that includes residues of an aldehyde other than n-butyraldehyde are provided. Such compositions, layers, and interlayers can exhibit enhanced or optimized properties as compared to those formulated with comparable poly(vinyl n-butyral) resins.