US 11,939,413 B2
Acrylic resin powder, resin composition, hot melt adhesive composition containing acrylic resin powder and method for producing same
Shogo Miyai, Tokyo (JP); and Toru Kondo, Tokyo (JP)
Assigned to Mitsubishi Chemical Corporation, Tokyo (JP)
Filed by Mitsubishi Chemical Corporation, Tokyo (JP)
Filed on Sep. 25, 2020, as Appl. No. 17/031,988.
Application 17/031,988 is a continuation of application No. PCT/JP2019/012407, filed on Mar. 25, 2019.
Claims priority of application No. 2018-058236 (JP), filed on Mar. 26, 2018.
Prior Publication US 2021/0009868 A1, Jan. 14, 2021
Int. Cl. C08F 265/06 (2006.01); C08F 20/14 (2006.01); C08G 18/62 (2006.01); C08J 3/12 (2006.01); C09J 133/12 (2006.01); C09J 175/06 (2006.01)
CPC C08F 265/06 (2013.01) [C08F 20/14 (2013.01); C08G 18/6225 (2013.01); C08J 3/12 (2013.01); C09J 133/12 (2013.01); C09J 175/06 (2013.01); C08J 2333/12 (2013.01); C08J 2433/12 (2013.01)] 14 Claims
 
1. An acrylic resin powder, comprising:
a multi-stage polymer (M) comprising:
a polymer (B) obtained by polymerizing a monomer mixture (b) in the presence of a polymer dispersion of a polymer (A) obtained by polymerizing a monomer mixture (a) containing 50% to 60% by mass of methyl methacrylate and an alkyl (meth)acrylate ester (ma);
wherein
the monomer mixture (b) comprises:
50% to 90% by mass of methyl methacrylate,
10% to 50% by mass of an alkyl (meth)acrylate ester (mb), and
0% to 10% by mass of a copolymerizable monomer different from methyl methacrylate and the alkyl (meth)acrylate ester (mb),
the alkyl group of the alkyl (meth)acrylate ester (ma) has 4 to 8 carbon atoms,
the alkyl group of the alkyl (meth)acrylate ester (mb) bas 4 to 8 carbon atoms,
a glass transition temperature of the polymer (A) is 20° C. or lower,
a glass transition temperature of the polymer (B) is 55° C. or higher,
the acrylic resin powder is soluble in acetone, and
a mass average molecular weight of the multi-stage polymer (M) is 10,000 or more and 300,000 or less.