Intermediate film for laminated glass, method for producing intermediate film for laminated glass, and laminated glass

A method for producing an interlayer film for a laminated glass comprising a laminate that includes two or more resin layers in a stack and having a multitude of protrusions and recesses on at least one surface,

• wherein a maximum height Ry (μm) and an average interval Sm (μm) of the protrusions and recesses measured in conformity with JIS B 0601 (1994) on the surface having the multitude of protrusions and recesses satisfy the following formula (1):
• (Ry×Sm)/2≤3,500 (1),
• wherein the method comprises a step of providing the multitude of protrusions and recesses on at least one surface of the interlayer film for a laminated glass by an extrusion lip embossing method utilizing melt fracture, and
• wherein the step includes coextrusion of resins from a co-extruder under the following conditions:
• a resin pressure at an inlet of a die of 40 to 150 kgf/cm2,
• a resin temperature of 160° C. to 250° C.,
• a die temperature of 100° C. to 270° C.,
• a width of an outlet of the die of 700 to 3,500 mm,
• an extrusion amount per width of the outlet of the die of 130 to 1,700 kg/hr·m,
• a film surface temperature immediately after ejection from the outlet of the die of 170° C. to 250° C.,
• a distance from the outlet of the die to a cooling water tank of 10 to 400 mm, and
• a water temperature in the cooling water tank of 10° C. to 70° C.