Process for preparing episulfide resins

Patent metadata

Field	Value
Publication number	US-8969503-B2
Application number	US-201013497110-A
Country	US
Kind code	B2
Filing date	Sep 21, 2010
Priority date	Sep 22, 2009
Publication date	Mar 3, 2015
Grant date	Mar 3, 2015

Abstract

A process for converting epoxy resin to episulfide resin through reactive melt extrusion of a solid epoxy resin with a sulfur donating compound. The resulting resin provides for an application that utilizes the resulting extruded episulfide resin as a low application temperature resin for powder coatings applications.

First claim

What is claimed is:

1. A process for producing an episulfide resin composition comprising melt reacting a solid reaction mixture of (a) at least one epoxy resin in solid form with (b) at least one sulfur donating compound, wherein the sulfur donating compound comprises thiourea; wherein the episulfide resin composition includes both urea and a solid reaction product and is formed by melt reaction.

2. The process of claim 1 , wherein the at least one sulfur donating compound is in solid form.

3. The process of claim 1 , wherein the reaction is carried out in a melt extruder.

4. The process of claim 1 , wherein the at least one epoxy resin is a solid epoxy resin from a 1.5-type to a 10-type epoxy resin.

5. The process of claim 1 , wherein the molar ratio of the at least one epoxy resin to the sulfur donating compound is from about 1:0.01 to about 1:1.

6. The process of claim 1 , wherein the reaction is carried out at a temperature of from at least about 5° C. above the Tg of the epoxy resin reactant component (a).

7. An episulfide resin composition comprising both a solid reaction product of (a) at least one epoxy resin in solid form with (b) at least one sulfur donating compound without a solvent, wherein the sulfur donating compound comprises thiourea, and a by-product of the sulfur donating compound comprising urea; wherein the episulfide resin composition is formed by reacting through melt extrusion components (a) and (b).

8. The episulfide resin composition product of claim 7 having less than about 1 percent volatile organic compounds (VOCs).

9. The episulfide resin composition product of claim 7 having a chlorine content of less than about 1000 ppm.

10. A powder coating formulation comprising the reaction product of (i) the episulfide resin composition product of claim 7 ; and (ii) a flow modifier.

11. The powder coating formulation of claim 10 , including (iii) a curing agent; (iv) a curing catalyst; (v) a filler; or (vi) a solvent.

12. The episulfide resin composition product of claim 7 , wherein the epoxy resin comprises a reaction product of an aromatic bisphenol and epichlorohydrin.

Assignees

• Aguirre Vargas Fabio
• Thibault Raymond J
• Beckerdite John
• Dow Global Technologies Llc

Inventors

• Aguirre Vargas Fabio
• Thibault Raymond J
• Beckerdite John

Classifications

• C08G75/08

  from thiiranes · CPC title

• C08G75/06 Primary

  from cyclic thioethers · CPC title

• C08G59/1483

  containing sulfur · CPC title

• C09D163/00

  Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins · CPC title

• C08K5/36

  Sulfur-, selenium-, or tellurium-containing compounds {(C08K5/0091 takes precedence)} · CPC title