Method for producing acrylic polymer, acrylic polymer, and plastisol composition
Disclosed is a method for producing a plastisol acrylic polymer which can have a satisfactory adhesion property even when the heating time is short and the heating temperature is low, and which has excellent storage stability. The method comprises (1) a step of polymerizing an acrylic monomer mixture (a) to produce a polymer (A) and (2) a step of polymerizing an acrylic monomer mixture (b) in a dispersion containing the polymer (A), wherein a monomer having a hydroxy group is contained in the acrylic monomer mixture (a), a monomer having an acetoacetyl group or a block isocyanate group is contained in the acrylic monomer mixture (b), and the dissolution parameter (SA) for the polymer (A) and the dissolution parameter (SB) for a polymer (B) produced by the polymerization of the acrylic monomer mixture (b) are different from each other.
1. An acrylic polymer obtained by
polymerizing an acrylic monomer mixture (a) to obtain a polymer (A); and
polymerizing an acrylic monomer mixture (b) in a dispersion comprising the polymer (A), wherein
the acrylic monomer mixture (a) comprises a monomer having a hydroxyl group,
the acrylic monomer mixture (b) comprises a monomer having an acetoacetyl group or a blocked isocyanate group, and
a solubility parameter (SA) of the polymer (A) is different from a solubility parameter (SB) of a polymer (B) obtained by polymerizing the acrylic monomer mixture (b),
wherein the acrylic monomer mixture (b) comprises the monomer having an acetoacetyl group or a blocked isocyanate group in an amount of 0.7 to 15 mol % based on 100 mol % of the acrylic monomer mixture (b),
wherein the acrylic monomer mixture (a) comprises the monomer having a hydroxyl group in an amount of 0.1 to 15 mol % based on 100 mol % of the acrylic monomer mixture (a), and
wherein the acrylic monomer mixture (a) further comprises methyl methacrylate, butyl methacrylate, or a combination thereof, in a total amount of 55 mol % or greater based on 100 mol % of the acrylic monomer mixture (a).
2. A plastisol composition comprising the acrylic polymer of claim 1 and a plasticizer.
3. The acrylic polymer of claim 1 , wherein the monomer having a hydroxyl group is at least one monomer selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and dipentaerythritol hexa(meth)acrylate.
4. The acrylic polymer of claim 1 , wherein the monomer having a hydroxyl group is at least one monomer selected from the group consisting of 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.
5. The acrylic polymer of claim 1 , wherein the acrylic monomer mixture (a) comprises the monomer having a hydroxyl group in an amount of 0.1 to 10 mol % based on 100 mol % of the acrylic monomer mixture (a).
6. The acrylic polymer of claim 1 , wherein the acrylic monomer mixture (a) further comprises methyl methacrylate and butyl methacrylate in a molar ratio within a range of from 20:80 to 75:25.
7. The acrylic polymer of claim 1 , wherein the acrylic monomer mixture (b) comprises a monomer having an acetoacetyl group.
8. The acrylic polymer of claim 1 , wherein the acrylic monomer mixture (b) comprises a monomer having a blocked isocyanate group.
9. The acrylic polymer of claim 7 , wherein the monomer having an acetoacetyl group is at least one monomer selected from the group consisting of 2-acetoacetoxyethyl (meth)acrylate, 2-acetoacetoxypropyl (meth)acrylate, 2-cyanoacetoacetoxyethyl methacrylate, N-(2-acetoxyaminoethyl) (meth)acrylamide, allyl acetoacetate, and vinyl acetoacetate.
10. The acrylic polymer of claim 8 , wherein the monomer having a blocked isocyanate group is at least one monomer selected from the group consisting of 2[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate and 2-[O-(1′-methyl propylidene amino)carboxyamino]ethyl methacrylate.
11. The acrylic polymer of claim 1 , wherein the acrylic monomer mixture (b) comprises the monomer having an acetoacetyl group or a blocked isocyanate group in an amount of 0.7 to 9 mol % based on 100 mol % of the acrylic monomer mixture (b).
12. The acrylic polymer of claim 1 , wherein the monomer having a hydroxyl group is a (meth)acrylic acid ester having a hydroxyl group.