Isocyanate-Terminated Prepolymer Composition and a Polyurethane or Polyurea Elastomer Produced Therefrom

• US 20080097068A1
• Filed: 10/11/2005
• Published: 04/24/2008
• Est. Priority Date: 10/15/2004
• Status: Abandoned Application

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Mueller, Gerhard, Thiede, Verena, Bruchertseifer, Christian
• Application Number:
  US11/660,807
• Publication Number:
  US 20080097068A1
• Time in Patent Office: Days
• US Class Current: 528/85
• 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 18/4277 Caprolactone and/or substituted caprolactone
• CPC Class Codes: C08G 18/7671 containing only one alkylene bisphenyl group

Abstract

The present invention relates to an isocyanate-terminated prepolymer composition obtained from reaction of a methylene diphenylisocyanate, comprising at least 25 weight percent of the 2,4′- isomer, with a polycaprolactone polyol; and to polyurethane or polyurea elastomers obtained from the said isocyanate-terminated prepolymer composition.

Claims

1. ) An isocyanate-terminated prepolymer composition that has an isocyanate content of from 1 to 25 weight percent and which is the reaction product of:

a) a polyol composition comprising a polycaprolactone polyol having an average molecular weight of from 400 to 10000 Dalton and an average hydroxyl functionality of from 2 to 4;

with

b) a stoichiometric excess of an isocyanate mixture that contains methylene diphenylisocyanate (MDI) in at least about 60 weight percent of the total isocyanate present and wherein the MDI comprises the 2,4′

- and 4,4′

-methylene diphenylisocyanate isomer in a molar ratio of from 25;

75 to 80;

20.

2. ) The isocyanate-terminated prepolymer composition of claim 1 having an average isocyanate content of from 8 to 20 weight percent.

3. ) The isocyanate-terminated prepolymer composition of claim 1 wherein the isocyanate mixture (b) consists essentially of 2,4′

- and 4,4′

-methylene diphenylisocyanate.

4. ) The isocyanate-terminated prepolymer composition of claim 3 wherein the 2,4′

- and 4,4′

-methylene diphenylisocyanate isomers are present in a molar ratio of from 30;

70 to 70;

30.

5. ) The isocyanate-terminated prepolymer composition of claim 1 wherein the polyol comprises a polycaprolactone polyol having an average molecular weight of from 400 to 5000 Dalton and an average hydroxyl functionality of from 2 to 4.

10. ) A two component system suitable for use in the manufacture of polyurethane elastomers which comprises as individual components:

a) an isocyanate-terminated prepolymer composition as claimed in claim 1;

and

b) an isocyanate-reactive composition that contains (i) a polyether or polyester polyols or high molecular weight amine-terminated polyoxyalkylene adduct, or mixtures of two or more thereof; and

optionally (ii) a chain extending agent being a low molecular weight dihydroxy substance or an aromatic or aliphatic polyamine, or mixtures of two or more thereof.

6. ) A isocyanate-terminated prepolymer composition suitable for spray elastomer applications which has an average isocyanate content of from 8 to 20 weight percent in is obtained by reacting a stoichiometric excess of an isocyanate mixture consisting essentially of 2,4′

- and 4,4′

-methylene diphenylisocyanate present in a molar ratio of from 30;

70 to 70;

30;

with a polyol composition comprising a polycaprolactone polyol or ether-modified polycaprolactone polyol having an average molecular weight of from 400 to 5000 Dalton

7. ) A polyurethane composition obtained from the reaction of:

a) an isocyanate-terminated prepolymer composition that has an isocyanate content of from 1 to 25 weight percent and which itself is obtained from the reaction of;

i) a polyol composition comprising a polycaprolactone polyol having an average molecular weight of from 400 to 10000 Dalton and an average hydroxyl functionality of from 2 to 4;

with

ii) a stoichiometric excess of an isocyanate mixture that contains methylene diphenylisocyanate (MDI) in at least about 60 weight percent of the total isocyanate present and wherein the MDI comprises the 2,4′

- and 4,4′

-methylene diphenylisocyanate isomer in a molar ratio of from 25;

75 to 80;

20;

with

b) one or more compounds selected from the group consisting of high molecular weight polyether or polyester polyols or polyamine substances, and optionally in the presence of

c) a low molecular weight chain extending agent.

8. ) The polyurethane composition of claim 7 wherein the chain extending agent c) when present is a dihydroxy substance.

9. ) The polyurethane composition of claim 7 wherein the chain extending agent c) when present is an aromatic or aliphatic polyamine.