PROBLEM TO BE SOLVED: To obtain an interlayer excellent in penetration resistance over a wide range of temperatures, good in adhesivity to glass surface, and capable of reducing disasters due to glass fragments when a laminated glass using the interlayer is broken, by incorporating a specific modified polyvinyl acetal with a plasticizer. SOLUTION: This interlayer for safety laminated glass contains a modified polyvinyl acetal(PVA) which has vinyl acetal units in the molecule and 2-20C hydroxyalkyl groups on the side chains which are required for lying bound directly to the main chain. In this case, it is preferable that each of the hydroxyalkyl groups is present in the form of an olefin unit containing this hydroxyalkyl group such as 3-butene-1-ol. The content of the hydroxyalkyl groups in the PVA is pref. 0.1-20mol%. The viscosity-average molecular weight and acetalization degree of the PVA are pref. 100-20,000 and 50-80mol%, respectively. This interlayer comprises 100 pts.wt. of the modified PVA and 20-80 pts.wt. of a plasticizer (e.g. triethylene glycol-di-2-ethyl butyrate).
【課題】 本発明は低温から高温までの広い温度領域に おいて優れた耐貫通強度を有する安全合わせガラス中間 膜を提供することにある。
【解決手段】 炭素数２〜２０のヒドロキシアルキル基 を側鎖に有する変性ポリビニルアセタールからなる安全 合わせガラス用中間膜。