Isocyanate-terminated prepolymer, the method for preparing the same and the use thereof

Patent metadata

Field	Value
Publication number	US-9434809-B2
Application number	US-201313768430-A
Country	US
Kind code	B2
Filing date	Feb 15, 2013
Priority date	Aug 24, 2009
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

The present invention pertains to the field of polyurethane, especially relates to an isocyanate-terminated prepolymer, the method for preparing the same and the use thereof. The present invention adjusts the reaction components and the ratios thereof to obtain an isocyanate-terminated prepolymer suitable for preparing flexible polyurethane foam under a relative low mold temperature. The method for preparing flexible polyurethane foam by using the isocyanate-terminated prepolymer provided in this present invention can reduce the mold temperature, production time and energy consumption, as well as to obtain a polyurethane flexible foam processing good physical and mechanical properties.

First claim

The invention claimed is:

1. An isocyanate-terminated prepolymer, wherein the isocyanate-terminated prepolymer comprises the reaction product of reaction components of a1, a2 and a3:
a1) 52-54% by weight of diphenylmethane diisocyanate (MDI), based on 100% by weight of the isocyanate-terminated prepolymer, wherein the diphenylmethane diisocyanate (MDI) comprises 73-79% by weight of 4,4′-diphenylmethane diisocyanate, based on 100% by weight of the diphenylmethane diisocyanate (MDI),
a2) 34-36% by weight of polymethylene polyphenyl polyisocyanate (PMDI), based on 100% by weight of the isocyanate-terminated prepolymer, wherein the polymethylene polyphenyl polyisocyanate (PMDI) has an average functionality of from 2.6 to 2.8, and
a3) 10-13% by weight of polyoxyethylene-polyoxypropylene polyol, based on 100% by weight of the isocyanate-terminated prepolymer, wherein the average functionality of the polyoxyethylene-polyoxypropylene polyol is 2-6, the average molecular weight is 2000-10000, and the average ethylene oxide content of the polyoxyethylene-polyoxypropylene polyol is 24-40% by weight, based on 100% by weight of the polyoxyethylene-polyoxypropylene polyol,

wherein, the NCO content of the isocyanate-terminated prepolymer is 27-30% by weight, based on 100% by weight of the isocyanate-terminated prepolymer.

2. The isocyanate-terminated prepolymer as claimed in claim 1 , wherein the average ethylene oxide content of the polyoxyethylene-polyoxypropylene polyol is 24-37% by weight, based on 100% by weight of the polyether polyol.

3. A method for preparing an isocyanate-terminated prepolymer, comprising the step of reacting components of a1, a2 and a3:
a1) 52-54% by weight of diphenylmethane diisocyanate (MDI), based on 100% by weight of the isocyanate-terminated prepolymer, wherein the diphenylmethane diisocyanate (MDI) comprises 73-79% by weight of 4,4′-diphenylmethane diisocyanate, based on 100% by weight of the diphenylmethane diisocyanate (MDI),
a2) 34-36% by weight of polymethylene polyphenyl polyisocyanate (PMDI) having an average functionality of from 2.6 to 2.8, based on 100% by weight of the isocyanate-terminated prepolymer, and
a3) 10-13% by weight of polyoxyethylene-polyoxypropylene polyol, based on 100% by weight of the isocyanate-terminated prepolymer, wherein the average functionality of the polyoxyethylene-polyoxypropylene polyol is 2-6, the average ethylene oxide content of the polyoxyethylene-polyoxypropylene polyol is 24-40% by weight, based on 100% by weight of the polyoxyethylene-polyoxypropylene polyol,
wherein the NCO content of the isocyanate-terminated prepolymer is 27-30% by weight, based on 100% by weight of the isocyanate-terminated prepolymer.

4. The method as claimed in claim 3 , wherein the average ethylene oxide content of the polyoxyethylene-polyoxypropylene polyol is 24-37% by weight, based on 100% by weight of the polyether polyol.

5. A method for preparing a flexible polyurethane foam comprising the step of reacting components of A, B and C:
A) isocyanate-terminated prepolymer as claimed in claim 1 or 2 ,
B) polyol, comprising;
b1) 0.1-20 weight parts of at least a first polyoxyethylene-polyoxypropylene polyol, based on 100% by weight of B and C, wherein the functionality of the first polyoxyethylene-polyoxypropylene polyol is equal to or more than 2, the average ethylene oxide content of the first polyoxyethylene-polyoxypropylene polyol is equal to or more than 50% by weight,
b2) 30-90 weight parts of a second polyoxyethylene-polyoxypropylene polyol, based on 100% by weight of B and C, wherein the hydroxyl value of the second polyoxyethylene-polyoxypropylene polyol is 25-40 mg/KOH, the average ethylene oxide content of the second polyoxyethylene-polyoxypropylene polyol is equal to or less than 30% by weight,
b3) 5-60 weight parts of polymer polyol,
b4) 0.01-15 weight parts of chain extender,
b5) 0.01-20 weight parts of catalyst and/or foam stabilizer, and
C) 0.1-7 weight parts of water,

wherein the NCO index of the reaction is 70-120.

6. The method as claimed in claim 5 , wherein the reaction of reaction components A, B and C is carried out in a mould, and the mould temperature is 15-40° C.

Assignees

• Bayer Materialscience Ag
• Covestro Deutschland Ag

Inventors

• Lin Jen-Chieh
• Kung Hochien
• Zhu Hong

Classifications

• C08G18/14

  Manufacture of cellular products · CPC title

• C08G18/7664

  containing alkylene polyphenyl groups · CPC title

• C08G18/7671

  containing only one alkylene bisphenyl group · CPC title

• C08G18/7657 Primary

  containing two or more aromatic rings · CPC title

• C08G18/12 Primary

  using two or more compounds having active hydrogen in the first polymerisation step · CPC title