Non-spherical resin particles, manufacturing method thereof, and use thereof

Patent metadata

Field	Value
Publication number	US-9527969-B2
Application number	US-201214129348-A
Country	US
Kind code	B2
Filing date	Jun 29, 2012
Priority date	Jun 30, 2011
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

The invention provides non-spherical resin particles with a novel shape capable of improving light diffusion, adhesion, oil absorption, and other properties, as well as a manufacturing method and use of the particles. Each non-spherical resin particle includes a concave portion and a convex portion formed in the concave portion, wherein the convex portion has a quasi-spherical surface. The method of manufacturing non-spherical resin particles involves a step of polymerizing 100 parts by weight of a first monomer mixture containing 77 to 99.99 parts by weight of a branched alkyl methacrylate, 0.01 to 3 parts by weight of a polyfunctional monomer, and 0 to 20 parts by weight of a monofunctional (meth)acrylate which is not a branched alkyl methacrylate, in the presence of 0.1 to 0.9 parts by weight of a chain transfer agent and 0 to 100 parts by weight of a (meth)acrylate polymer, to obtain resin particles.

First claim

The invention claimed is:

1. Non-spherical resin particles, wherein each of the non-spherical resin particles comprises a contiguous surface,
wherein the contiguous surface comprises:
a first concave portion;
a convex portion formed in the first concave portion; and
a spherical portion;
wherein the convex portion has a quasi-spherical surface;
and wherein the contiguous surface forms a cavity between the spherical portion and the convex portion;
wherein each of the non-spherical resin particles has a diameter represented by “a”;
the convex portion of said each of the non-spherical resin particles has a diameter represented by “b”;
the first concave portion of said each of the non-spherical resin particles has a diameter represented by “c”;
and wherein the ratio of b/a is in the range of 0.25 to 0.70 and the ratio of c/a is greater than 0.20.

2. The non-spherical resin particles as set forth in claim 1 , wherein the surfaces of the spherical portions of said non-spherical resin particles have one or more second concave portions smaller than the first concave portions of the non-spherical resin particles.

3. The non-spherical resin particles as set forth in claim 1 , wherein:
each of the non-spherical resin particles has a second concave portion smaller than the first concave portion of said each of the non-spherical resin particles on a surface of a spherical portion of said each of the non-spherical resin particles; and
the second concave portion has a maximum depth of greater than or equal to 50 nm and less than or equal to 500 nm.

4. The non-spherical resin particles as set forth in claim 1 , wherein said particles have diameters with a coefficient of variation of less than or equal to 15%.

5. A method of manufacturing non-spherical resin particles of claim 1 , comprising:
the first step of polymerizing 100 parts by weight of a first monomer mixture containing 77 to 99.99 parts by weight of a branched alkyl methacrylate, 0.01 to 3 parts by weight of a polyfunctional monomer, and 0 to 20 parts by weight of a monofunctional (meth)acrylate which is not a branched alkyl methacrylate, in the presence of 0.1 to 0.9 parts by weight of a chain transfer agent and 0 to 100 parts by weight of a (meth)acrylate polymer, to obtain resin particles; and
the second step of letting the obtained resin particles to absorb a second monomer mixture containing a monofunctional aliphatic monomer and a polyfunctional monomer, and thereafter polymerizing the resin particles,
wherein in the second step, the polyfunctional monomer is used in an amount of from 5 to 50 wt % to the amount of the monofunctional aliphatic monomer being used.

6. The method as set forth in claim 5 , wherein in the second step, 5 to 50 parts by weight of the resin particles absorb 100 parts by weight of the second monomer mixture.

7. An external preparation, comprising the non-spherical resin particles as set forth in claim 1 .

8. A coating material, comprising the non-spherical resin particles as set forth in claim 1 .

9. A light diffusion member, comprising the non-spherical resin particles as set forth in claim 1 .

Assignees

• Nakamura Masaaki
• Harada Ryosuke
• Sekisui Plastics

Inventors

• Nakamura Masaaki
• Harada Ryosuke

Classifications

• A61P17/00

  Drugs for dermatological disorders · CPC title

• C08L47/00

  Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds; Compositions of derivatives of such polymers (C08L45/00 takes precedence; of conjugated diene rubbers C08L9/00 - C08L21/00) · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title

• C08F2/38

  Polymerisation using regulators, e.g. chain terminating agents {, e.g. telomerisation} · CPC title

• C08F265/06

  Polymerisation of acrylate or methacrylate esters on to polymers thereof · CPC title