(Meth)acrylic polymer particle, method for producing the same, plastisol composition made from the polymer particle, and article made from the plastisol composition
View Patent ↗Disclosed are an industrially useful (meth)acrylic polymer particle for use in a plastisol which is excellent in storage stability, particularly under circumstance at 40° C. or above, so that it can suppress gelation and maintain a sol state during storage and which can give a shaped article excellent in flexibility and chipping resistance; a method for producing the (meth)acrylic polymer particle; and a plastisol composition made from the (meth)acrylic polymer particle. Specifically disclosed is a method for producing a (meth)acrylic polymer particle, which comprises polymerizing a monomer or monomer mixture (B) to form a polymer (b) in the presence of a polymer (a) obtained by polymerization of a monomer or monomer mixture (A), wherein a glass transition temperature (Tg) of the polymer (a) as calculated from the FOX equation is 90° C. or above, a solubility parameter of the polymer (a) is 19.90 (J/cm 3 ) 1/2 or below, and a solubility parameter of the polymer (b) is 20.22 (J/cm 3 ) 1/2 or above.
1. A method for producing a (meth)acrylic polymer particle, comprising polymerizing a monomer or monomer mixture (B) to form a polymer (b) in the presence of a polymer (a) obtained by a process comprising polymerizing a monomer or monomer mixture (A), wherein a glass transition temperature (Tg) of the polymer (a) as calculated from the FOX equation is 90° C. or above, a solubility parameter of the polymer (a) is 19.90 (J/cm 3 ) 1/2 or below, and a solubility parameter of the polymer (b) is 20.22 (J/cm 3 ) 1/2 or above, and the monomer or monomer mixture (A) comprises 10% by mass or more of t-butyl methacrylate.
2. A method for producing a (meth)acrylic polymer particle, comprising polymerizing a monomer or monomer mixture (B) to form a polymer (b) in the presence of a polymer (a) obtained by a process comprising polymerizing a monomer or monomer mixture (A), wherein a glass transition temperature (Tg) of the polymer (a) as calculated from the FOX equation is 90° C. or above, a solubility parameter of the polymer (a) is 19.90 (J/cm 3 ) 1/2 or below, and a solubility parameter of the polymer (b) is 20.22 (J/cm 3 ) 1/2 or above, and the monomer or monomer mixture (A) comprises 0.01% by mass or more and less than 10% by mass of a monomer comprising a hydroxyl group or an acetoacetyl group.
3. A (meth)acrylic polymer particle obtained by the method of claim 1 .
4. A plastisol composition comprising the (meth)acrylic polymer particle according to claim 3 and a plasticizer, wherein the plasticizer comprises 60% by mass or more of a plasticizer having a solubility parameter in a range of from 18.40 (J/cm 3 ) 1/2 or above to lower than 18.71 (J/cm 3 ) 1/2 .
5. A plastisol composition comprising the (meth)acrylic polymer particle according to claim 3 and a plasticizer, wherein the plasticizer comprises 1% by mass or more and less than 40% by mass of a plasticizer having a solubility parameter in a range of from 18.71 (J/cm 3 ) 1/2 or above to lower than 20.45 (J/cm 3 ) 1/2 .
6. An article comprising the plastisol composition according to claim 4 .
7. An undercoating material for an automobile comprising the plastisol composition according to claim 4 .
8. A body sealer comprising the plastisol composition according to claim 4 .
9. An article comprising the plastisol composition according to claim 5 .
10. An undercoating material for an automobile comprising the plastisol composition according to claim 5 .
11. A body sealer comprising the plastisol composition according to claim 5 .
12. The method for producing a (meth)acrylic polymer particle according to claim 1 , wherein the mass ratio of polymer (a) to polymer (b) is from 65/35 to 95/5.
13. A method for producing a (meth)acrylic polymer particle, comprising polymerizing a monomer or monomer mixture (B) to form a polymer (b) in the presence of a polymer (a) obtained by a process comprising polymerizing a monomer or monomer mixture (A), wherein a glass transition temperature (Tg) of the polymer (a) as calculated from the FOX equation is 90° C. or above, a solubility parameter of the polymer (a) is 19.90 (J/cm 3 ) 1/2 or below, and a solubility parameter of the polymer (b) is 20.22 (J/cm 3 ) 1/2 or above, and the (meth)acrylic polymer particle has a mass average molecular weight of from 10,000 to 5,000,000.
14. The method for producing a (meth)acrylic polymer particle according to claim 1 , wherein the particle diameter of the (meth)acrylic polymer particle is from 0.1 μm to 2.0 μm.
15. The method for producing a (meth)acrylic polymer particle according to claim 1 , wherein the monomer mixture (A) is polymerized by emulsion polymerization, seed polymerization, soap-free polymerization, dispersion polymerization, or micro suspension polymerization.
16. The method for producing a (meth)acrylic polymer particle according to claim 1 , wherein two or more monomer mixtures (B) are polymerized in the presence of polymer (a) after the polymerization of monomer mixture (A).
17. The plastisol composition according to claim 4 , wherein the content of the (meth)acrylic polymer particle in the plastisol composition is from 5% to 70% by mass.
18. The plastisol composition according to claim 4 , wherein the plastisol further comprises at least one additive selected from the group consisting of a pigment, an antifoamer, a mildewproofing agent, a deodorant, an antimicrobial, a surfactant, a lubricant, an ultraviolet absorbent, a spice, a foaming agent, a leveling agent, an adhesive, a viscosity reducing agent, and a diluent.
19. The plastisol composition according to claim 4 , wherein the plastisol further comprises calcium carbonate.