Voided latex particles

Patent metadata

Field	Value
Publication number	US-2019292346-A1
Application number	US-201916435716-A
Country	US
Kind code	A1
Filing date	Jun 10, 2019
Priority date	Aug 22, 2014
Publication date	Sep 26, 2019
Grant date	—

Abstract

A process for forming voided latex particles is improved by combining swelling and polymerization of an outer shell into a single step. The process includes contacting multi-stage emulsion polymer particles comprising a core, at least one intermediate shell, with a swelling agent, and polymerizing an outer shell after said contacting with swelling agent wherein the core and the at least one intermediate shell are contacted with swelling agent in the presence of less than 0.5% monomer based on the weight of the multi-stage emulsion polymer particles, and substantially all of the swelling occurs during polymerization of the outer shell.

First claim

1 . A voided latex particle having a hollow interior, said voided latex particle comprising:
(i) optionally a core comprising a hydrophilic component, (ii) at least one intermediate shell comprising, as polymerized units, one or more hydrophilic monoethylenically unsaturated monomer, one or more nonionic monoethylenically unsaturated monomer, or mixtures thereof, and (iii) an outer shell comprising a polymer having a Tg of at least 60° C. and bearing one or more functional groups selected from the group consisting of 1,3-diketo, amino, ureido, urea, hydroxyl, polyether, silane, phosphate, epoxy, fluorocarbon, aldehyde, ketone, acetoacetyl, functional groups or combinations thereof, wherein the voided latex particle is non-film-forming and opaque.

2 . The voided latex particle of claim 1 , wherein the outer shell comprises polymer bearing phosphate functional groups.

3 . The voided latex particle of claim 1 , wherein the outer shell comprises polymer bearing 1,3-diketo functional groups.

4 . The voided latex particle of claim 1 , wherein the outer shell comprises polymer bearing acetoacetyl functional groups.

5 . The voided latex particle of claim 1 , wherein the outer shell comprises polymer bearing silane functional groups.

6 . The voided latex particle of claim 1 , wherein the outer shell comprises polymer bearing ureido functional groups.

7 . The voided latex particle of claim 1 , wherein the outer shell comprises polymer bearing urea functional groups.

8 . The voided latex particle of claim 1 , wherein the outer shell polymer is a copolymer of a vinyl aromatic monomer and a polymerizable ethylenically unsaturated monomer containing one or more of said functional groups and combinations thereof.

9 . The voided latex particle of claim 8 , wherein the vinyl aromatic monomer is styrene.

10 . The voided latex particle of claim 8 , wherein the polymerizable ethylenically unsaturated monomer contains a (meth)acrylate or (methacrylamide) group.

11 . The voided latex particle of claim 8 , wherein the copolymer contains from 0.1 to 10 weight % of the polymerizable ethylenically unsaturated monomer.

12 . The voided latex particle of claim 8 , wherein the polymerizable ethylenically unsaturated monomer is selected from the group consisting of acetoacetoxy(meth)acrylates, allyl acetoacetate, methylolated diacetone (meth)acrylamides, aminoalkyl(meth)acrylates, and ethylenically unsaturated polymerizable aziridinyl monomers and combinations thereof.

13 . The voided latex particle of claim 1 , wherein the at least one intermediate shell is an encapsulating polymer layer configured between the hollow interior and outer shell.

14 . The voided latex particle of claim 1 , wherein the at least one intermediate shell comprises hydrophilic monomer in a lower proportion than that in any core polymer present.

15 . The voided latex particle of claim 1 , comprising a first intermediate shell layer comprising a copolymer of methacrylic acid, styrene, and methyl methacrylate.

16 . The voided latex particle claim 15 , further comprising a second intermediate shell layer comprising copolymerized methyl methacrylate and styrene.

17 . The voided latex particle of claim 1 , wherein the core is present and comprises methyl methacrylate, and/or copolymerized methacrylic acid and methyl methacrylate.

18 . A coating composition comprising voided latex particles in accordance with claim 1 .

19 . The coating composition of claim 18 , further comprising film-forming latex particles.

20 . The coating composition of claim 19 , wherein at least a portion of the film-forming latex particles bear functional groups that interact with the functional groups of the outer shell polymer.

21 . The coating composition of claim 18 , wherein said latex is an acrylic and/or vinyl acrylic latex.

22 . A paint composition comprising the coating composition of claim 19 , further comprising one or more of coalescing solvent, biocides, pigments, fillers, titanium dioxide, calcium carbonate, thickeners, leveling agents, pH adjusting agents, surfactants, or antifreeze agents.

Assignees

• Arkema Inc

Inventors

• Liu Lily
• Devonport Wayne
• Stark Sr Daniel Edward
• Boudreaux Matthew F

Classifications

• C08F6/006

  Removal of residual monomers by chemical reaction, e.g. scavenging · CPC title

• C08J2433/12

  Homopolymers or copolymers of methyl methacrylate · CPC title

• C08J9/224 Primary

  Surface treatment · CPC title

• C08F285/00 Primary

  Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers · CPC title

• C08J2201/04

  characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation · CPC title