| abstract |
(57) Abstract: A method for producing a polyvinyl acetal capable of shortening the production time is provided. Moreover, the interlayer film for laminated glass and laminated glass are obtained using the polyvinyl butyral obtained by this manufacturing method. In a method for producing polyvinyl acetal by condensing polyvinyl alcohol and an aldehyde compound, polyvinyl alcohol having a 1,2-glycol bond content of 1.70 mol% or less is used. Using polyvinyl butyral among the polyvinyl acetals obtained by this production method, an interlayer film for laminated glass and a laminated glass are obtained by a method similar to the conventional one. |