Nanocomposites containing crystalline polyester and organosilica

Patent metadata

Field	Value
Publication number	US-11091631-B2
Application number	US-201716346252-A
Country	US
Kind code	B2
Filing date	Nov 2, 2017
Priority date	Nov 4, 2016
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

The invention provides a process for preparing core-shell composite particles comprising a polyester, polymerized ethylenically unsaturated silane compounds, and optionally a hydrophobic surface treatment. The invention further provides a composite particle comprising a polyester and a radically polymerized ethylenically unsaturated silane compound.

First claim

The invention claimed is:

1. A process for preparing core-shell composite particles comprising:
(i) providing a solution comprising one or more polyesters and up to 10 parts by mass, per part of the total amount of polyester, of a first ethylenically unsaturated silane compound having alkoxysilane groups in an organic solvent;
(ii) adding sufficient base to the solution provided in step (i) to deprotonate acid groups on the polyester in solution;
(iii) adding water to the solution obtained in step (ii) to form an emulsion;
(iv) distilling at least a portion of the solvent and the base from the emulsion to bring the emulsion to a pH of from 5 to 7;
(v) adding up to 30 parts by mass, per part of the total amount of polyester, of a second ethylenically unsaturated silane compound having alkoxysilane groups to the emulsion;
(vi) radically polymerizing the first and second ethylenically unsaturated silane compounds to form a shell of the polymerized silane compounds about the polyesters to provide a dispersion of core-shell particles; and
(vii) cross-linking the polymerized ethylenically unsaturated silane compound by hydrolyzing and condensing at least a portion of the alkoxysilane groups,
wherein the core shell composite particles are produced with at least 0.1 total parts of ethylenically unsaturated silane compound having alkoxysilane groups per part of the total amount of polyester.

2. The process of claim 1 , further comprising surface-treating the core shell particles with a hydrophobizing agent.

3. The process of claim 2 , wherein the hydrophobizing agent comprises a silane and/or a silazane and wherein cross-linking and hydrophobizing are performed simultaneously.

4. The process of claim 1 , wherein the first and second ethylenically unsaturated silane compounds have the same composition.

5. The process of claim 1 , wherein a portion of alkoxysilane groups of the first ethylenically unsaturated silane compound are hydrolyzed before radically polymerizing.

6. The process of claim 1 , further comprising adding a vinyl monomer, an acrylic monomer, or an alkoxysilane to the emulsion in step (v).

7. The process of claim 1 , further comprising isolating the core-shell particles.

8. The process of claim 1 , wherein the first and second ethylenically unsaturated silane compounds independently have a structure R 4 SiR′ m (OR″) n , wherein R 4 is either C2-C4 alkenyl or R 3 C(CH 2 )(CO)OR 2 —, R 3 is either H or C1-C6 alkyl, R 2 is C3-C22 alkylene, and R′ and R″ are independently C1-C6 alkyl, m is an integer of 0-2, and n is an integer of 1-3, wherein m+n=3.

9. A composite particle produced by the process of claim 1 .

10. A toner composition comprising toner particles and the composite particle produced by the process of claim 1 .

Assignees

• Cabot Corp

Inventors

• Fomitchev Dmitry
• Tu Hairuo
• Palumbo Paul S
• Kumar Samir

Classifications

• G03G9/09321

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• B01J13/203

  Exchange of core-forming material by diffusion through the capsule wall · CPC title

• G03G9/09307

  specified by the shell material · CPC title

• G03G9/09725

  Silicon-oxides; Silicates · CPC title

• C08L67/02 Primary

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title