Continuous process for preparing a polyurethane latex

• US 20020082342A1
• Filed: 02/27/2002
• Published: 06/27/2002
• Est. Priority Date: 03/17/1997
• Status: Abandoned Application

• Current Assignee: James E. Pate III, James J. Jakubowski, Wayne R. Willkomm
• Original Assignee: James E. Pate III, James J. Jakubowski, Wayne R. Willkomm
• Inventors: Willkomm, Wayne R., Pate, James E. III, Jakubowski, James J.
• Application Number:
  US10/085,913
• Publication Number:
  US 20020082342A1
• Time in Patent Office: Days
• US Class Current: 524/589
• CPC Class Codes: C08G 18/0866 the dispersing or dispersed phase being an aqueous medium
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/283 Compounds containing ether groups, e.g. oxyalkylated monohydroxy compounds
• CPC Class Codes: C08G 18/3246 heterocyclic, the heteroatom being oxygen or nitrogen in the form of an amino group

Abstract

A polyurethane/urea/thiourea latex having a narrow molecular weight polydispersity and sub-micron particle size can be prepared by first preparing a high internal phase ratio (HIPR) emulsion of a polyurethane/urea/thiourea prepolymer, then contacting the emulsion with a chain-extending reagent under such conditions to form the polymer latex.

Claims

1. A composition comprising a polyurethane latex having a mean volume average particle size of not greater than about 1 micron and a solids content of at least 45 percent by weight, wherein the polyurethane latex contains the following units:

2. The composition of claim 1, wherein the polyurethane latex contains units formed from 4,4′

-diisocyanatodiphenylmethane or 2,4′

-diisocyanatodiphenylmethane or a combination thereof.

3. The composition of claim 1, wherein the polyurethane latex has a solids content of not less than 50 percent by weight based on the total weight of the latex.

4. The composition of claim 3, wherein the latex has a solids content of not less than 55 percent by weight based on the total weight of the latex and has a volume average particle size of not greater than 0.5 micron and a polydispersity of not greater than 1.5.

5. The composition of claim 1, wherein the polyurethane latex has a mean volume average particle size of not greater than about 0.5 micron.