申请人:BASF Akiengesellschaft
公开号:US20030125459A1
公开(公告)日:2003-07-03
Described is a process for preparing aqueous polymer dispersions by at least two-stage free-radical aqueous emulsion polymerization of ethylenically unsaturated monomers, comprising:
1. a first polymerization stage, 1, in which a first monomer composition M(1) is polymerized in accordance with a monomer feed technique by adding a free-radical polymerization initiator I(1), giving an aqueous dispersion of a polymer P(1), and
2. a further polymerization stage, 2, in which
2
a
. a monomer composition M(2) whose makeup is different than that of the monomer composition M(
1
) is added in undiluted form to the aqueous dispersion of the polymer P(1), and
2
b
. the monomer composition M(2) is polymerized, and
3. if desired, steps 2a and 2b are repeated to carry out further polymerization stages, i,
the total amounts of the monomer M(2) making up from 0.1 to 20% by weight of the monomers M(
1
) polymerized in stage 1 and the addition of the monomer mixture M(2) not taking place before the end of the addition of the monomer mixture M(
1
), wherein the polymerization in polymerization stage 2 and any further polymerization stages takes place in the presence of residual amounts of the initiator I(1) added in the 1
st
stage or by adding further initiator I(1) and from the beginning of step 1 to the end of step 2
b
in the last polymerization stage the temperature in the reaction vessel is at least 70° C.,
and also the use of these polymer dispersions for preparing pressure sensitive adhesives.
描述了一种通过乙烯基不饱和单体的至少两级自由基水乳液聚合制备水性聚合物分散体的工艺,包括:
1. 第一聚合阶段,1,在该阶段中,通过添加自由基聚合引发剂 I(1),按照单体进料技术聚合第一单体组合物 M(1),得到聚合物 P(1)的水性分散体,和 2.
进一步聚合阶段 2,其中
2
a
单体组合物 M(2),其组成不同于单体组合物 M(
1
) 以未稀释的形式添加到聚合物 P( 1) 的水分散液中,以及
2
b
聚合单体组合物 M(2),以及
如果需要,重复步骤 2a 和 2b,以执行进一步的聚合阶段,即
单体 M(2) 的总量占单体 M(
1
)聚合量的 0.1%至 20%(按重量计),且单体混合物 M(2)的添加不在单体混合物 M(
1
),其中聚合阶段 2 和任何其他聚合阶段的聚合是在有第 1 阶段中添加的引发剂 I(1)的残余量存在的情况下进行的
第
或进一步加入引发剂 I(1),从步骤 1 开始到步骤 2 结束
b
在最后一个聚合阶段,反应容器内的温度至少为 70 摄氏度、
这些聚合物分散体还可用于制备压敏胶。