The invention relates to a process for the preparation of polymers stabilized with protective colloids in the form of water-redispersible powders or aqueous dispersions thereof having a reduced content of volatile components, by
a) polymerizing by emulsion or suspension polymerization, one or more monomers from the group consisting of vinyl esters, (meth)acrylates, vinyl aromatics, olefins, 1,3-dienes and vinyl halides and optionally further monomers copolymerizable therewith,
b) aftertreating the polymer dispersion thus obtained by means of postpolymerization, distillation, and/or introduction of steam or inert gas to obtain a residual content of volatile, nonaqueous components of <2000 ppm, and
c) spray drying of aftertreated polymer dispersion to a residual content of volatile, nonaqueous components of <400 ppm, the dispersion being adjusted prior to spray drying to a solids content of <45% by weight before spraying, the spray drying performed with gas at an inlet temperature of >120° C., and optimally
d) redispersing of the resulting powder in water.
本发明涉及一种用保护胶体稳定的聚合物的制备工艺,其形式为
水可再分散的粉末 或
水分散体,挥发性成分含量较低,制备方法为
a) 通过乳液聚合或悬浮聚合将
乙烯基酯、(甲基)
丙烯酸酯、
乙烯基芳烃、烯烃、1,3-二 烯和卤化
乙烯基以及可与之共聚的其他单体中的一种或多种单体聚合、
b) 通过后聚合、蒸馏和/或引入蒸汽或惰性气体对由此获得的聚合物分散体进行后处理,使挥发性非
水成分的残留量小于 2000 ppm,以及
c) 将处理后的聚合物分散液喷雾干燥,使挥发性非
水成分的残留量达到 120 摄氏度,最佳方法是
d) 将得到的粉末重新分散在
水中。