Fine polymer particles for plastisol, process for producing the same, and halogen-free plastisol composition and article made with the same

1. A non-halogenated plastisol composition comprising:

i) a fine particle of polymer for a plastisol free from halogen atoms and having a specific surface area of 0.6 to 20.0 m 2 /g as determined by nitrogen-gas adsorption and an oil absorption rate by linseed oil of 0.8 mL/g or less; and

ii) a plasticizer,

wherein said fine particle is of at least one polymer selected from the group consisting of acrylic polymers, acrylic copolymers, styrene polymers, styrene copolymers, butadiene polymers, butadiene copolymers, vinyl-acetate polymers, vinyl-acetate copolymers and a mixture thereof.

2. The non-halogenated plastisol composition of claim 1 wherein the fine particle of polymer has two or more polymer layers having different compositions concentrically from the particle center to its surface.

3. The non-halogenated plastisol composition of claim 1 , wherein said fine particle of polymer is in the form of agglomerates formed from a plurality of primary particles wherein the primary particles have an average particle size of at least 500 nm.

4. A process for manufacturing a non-halogenated plastisol composition comprising the steps of:

preparing an aqueous dispersion of a fine particle of polymer in which primary particles have an average particle size of at least 500 nm;

drying the aqueous dispersion at not lower than 50° C. but not higher than a glass-transition temperature of the polymer +20° C., by spray drying; and

blending with a plasticizer.

5. The non-halogenated plastisol composition of claim 1 , further comprising an inorganic filler.

6. The non-halogenated plastisol composition as claimed in claim 5 wherein viscosity values at shear speeds of 10000 sec −1 and 0.42 sec −1 are 0.1 to 1.0 Pa·s (25° C.) and 100 to 1000 Pa·s (25° C.), respectively.

7. The non-halogenated plastisol composition as claimed in claim 6 wherein the inorganic filler essentially consists of inorganic fillers with an average particle size of less than 2.0 μm (C1) and of 2.0 μm or more (C2) and a component, ratio of these inorganic fillers (C1) to (C2) (by weight) is 30/70 to 70/30.

8. The non-halogenated plastisol composition of claim 1 , wherein the plasticizer comprises a phthalic acid diester of an aliphatic alcohol having 7 to 10 carbon atoms in at least 50 wt %.

9. An article produced using the plastisol composition as claimed in any of claims 5 to 8 .

10. The non-halogenated plastisol composition of claim 1 , wherein said polymer is an acrylic polymer.

11. The non-halogenated plastisol composition of claim 1 , wherein said polymer is at least one copolymer selected from the group consisting of styrene-butadiene copolymer, acrylonitrile-butadiene copolymers and acryl-vinyl acetate copolymers.

12. A method of coating comprising applying the non-halogenated plastisol composition of claim 1 ; and curing.

13. A method of sealing comprising applying the non-halogenated plastisol composition of claim 1 ; and curing.

14. A method of undercoating an automobile comprising applying the non-halogenated plastisol composition of claim 1 to a surface of an automobile; and curing.

15. The method of coating of claim 12 , wherein said curing is by heating.

16. The method of sealing of claim 13 , wherein said curing is by heating.