@ The specification is concerned with sealant compositions comprising prepolymers which are capable of being cured by atmospheric moisture. The compositions provide a desirable blend of properties with regard to application and use, using prepolymers derived from comparatively inexpensive raw materials. The prepolymers correspond to a reaction product of an at least substantially linear acrylate ester polymer having a Tg of not greater than 10°C with a hydrolysable silane having a saturated organo-functional group, the reaction product being a fluid material soluble in organic solvents and curable by exposure to atmospheric moisture to a resilient solid. The prepolymer is a silane-modified polymer which preferably has from 2 to 3 hydrolysable silane groups per molecule of prepolymer and from 1 to 3 hydrolysable groups per silane group. Preferred acrylate ester polymers are homo- or co-polymers of butyl acrylate; copolymers may contain other acrylate monomers and or may contain up to 50 wt % vinyl monomer e.g. styrene. Preferred silanes are amino-silanes particularly those having 2 or 3 hydrolysable alkoxy groups. Also described and claimed are methods of making the prepolymers. The compositions are suited for construction and glazing sealants.
本说明书涉及的密封剂组合物包含可在大气湿气中固化的预聚物。这种组合物使用从相对廉价的原材料中提取的预聚物,在应用和使用方面提供了理想的混合特性。这种预聚物是一种 Tg 不大于 10°C 的至少是线性的
丙烯酸酯聚合物与具有饱和有机官能团的可
水解
硅烷的反应产物,反应产物是一种可溶于有机溶剂的流体材料,暴露在大气湿气中可固化成有弹性的固体。预聚物是一种
硅烷改性聚合物,每个预聚物分子最好有 2 至 3 个可
水解
硅烷基团,每个
硅烷基团最好有 1 至 3 个可
水解基团。优选的
丙烯酸酯聚合物是
丙烯酸丁酯的均聚物或共聚物;共聚物可含有其他
丙烯酸酯单体,或含有高达 50 wt % 的
乙烯基单体,如
苯乙烯。优选的
硅烷是
氨基
硅烷,特别是具有 2 或 3 个可
水解烷氧基的
氨基
硅烷。此外,还描述了预聚物的制造方法。这些组合物适用于建筑和
玻璃密封剂。