Aqueous dispersions of encapsulated polyisocyanates

• US 5,191,012 A
• Filed: 03/28/1991
• Issued: 03/02/1993
• Est. Priority Date: 03/28/1991
• Status: Expired due to Fees

• Current Assignee: Miles, Inc. (Bayer AG)
• Original Assignee: Miles, Inc. (Bayer AG)
• Inventors: Markusch, Peter H., Sarpeshkar, Ashok M., Tirpak, Robin E.
• Primary Examiner(s): Michl, Paul R.
• Assistant Examiner(s): NILAND, PATRICK DENNIS
• Application Number:
  US07/677,010
• Time in Patent Office: 705 Days
• Field of Search: 524/591, 524/874, 528/60, 528/61, 528/44
• US Class Current: 524/591
• CPC Class Codes: C08G 18/0804 Manufacture of polymers containing ionic or ionogenic groups
• CPC Class Codes: C08G 18/5036 containing -N-C=O groups
• CPC Class Codes: C08G 18/703 Isocyanates or isothiocyanates transformed in a latent form by physical means
• CPC Class Codes: C08G 18/8038 with compounds of C08G18/3225

Abstract

The present invention is directed to an aqueous dispersion of an encapsulated polyisocyanate which contains ureacted isocyanate groups and is prepared by

a) dispersing in water a polyisocyanate which has an isocyanate content of at least 12% by weight and

b) reacting the dispersed polyisocyanate with a polyamine having primary and/or secondary amino groups and a molecular weight of 400 or less in an amount sufficient to provide an equivalent ratio of amino groups to isocyanate groups of at least 0.05:1.0.

The present invention is also directed to aqueous compositions containing the previously described encapsulated polyisocyanate and an isocyanate-reactive compound.

Claims

1. An aqueous dispersion of an encapsulated polyisocyanate which contains unreacted isocyanate groups and is prepared by a process which comprises

a) dispersing in water a polyisocyanate which has an isocyanate content of at least 12% by weight and

b) reacting the dispersed polyisocyanate with a polyamine having primary and/or secondary amino groups and having a molecular weight of 400 or less in an amount sufficient to provide an equivalent ratio of amino groups to isocyanate groups of at least 0.05:

1.0.

2. The aqueous dispersion of claim 1 wherein said dispersed polyisocyanate was rendered hydrophilic by reaction with a compound containing a lateral or terminal nonionic hydrophilic group.

3. The aqueous dispersion of claim 1 wherein said equivalent ratio of amino groups to isocyanate groups is 0.05:

1.0 to 0.45;

1.0.

4. The aqueous dispersion of claim 2 wherein said equivalent ratio of amino groups to isocyanate groups is 0.05:

1.0 to 0.45;

1.0.

5. An aqueous composition which comprises a component which is reactive with isocyanate groups and an aqueous dispersion of an encapsulated polyisocyanate which contains unreacted isocyanate groups and is prepared by a process which comprises

a) dispersing in water a polyisocyanate which has an isocyanate content of at least 12% by weight and

b) reacting the dispersed polyisocyanate with a polyamine having primary and/or secondary amino groups and having a molecular weight of 400 or less in an amount sufficient to provide an equivalent ratio of amino groups to isocyanate groups of at least 0.05:

1.0.

6. The aqueous dispersion of claim 5 wherein said dispersed polyisocyanate was rendered hydrophilic by reaction with a compound containing a lateral or terminal nonionic hydrophilic group.

7. The aqueous dispersion of claim 5 wherein said equivalent ratio of amino groups to isocyanate groups is 0.05:

1.0 to 0.45;

1.0.

8. The aqueous dispersion of claim 6 wherein said equivalent ratio of amino groups to isocyanate groups is 0.05:

1.0 to 0.45;

1.0.