Interlayer for laminated glass, and laminated glass

A method for producing an interlayer film for laminated glass, comprising the step of:

• extruding a resin composition by using an extruder to obtain an interlayer film being an extrusion product,
• wherein the interlayer film is in a sea-island state having a sea-like dark part and a plurality of island-like bright parts to be identified when observed with a transmission electron microscope,
• a polyvinyl acetal resin is contained in the dark part region and a polyvinyl acetal resin is contained in the bright part region,
• the content ratio of the hydroxyl group of the polyvinyl acetal resin contained in the dark part region is higher than the content ratio of the hydroxyl group of the polyvinyl acetal resin contained in the bright part region,
• the ratio of the area of the bright part region to the total of the area of the dark part region and the area of the bright part region is less than or equal to 7.8%,
• the arithmetic average value of major diameters of the bright parts is less than or equal to 400 nm or the median value of major diameters of the bright parts is less than or equal to 400 nm, and
• the thickness of the interlayer film is greater than or equal to 0.1 mm.