Low viscosity polymer polyols characterized by a high hydroxyl number

Abstract

The present invention relates to novel polymer polyols which have low viscosities and high hydroxyl numbers, and to a process for the preparation of these novel polymer polyols. These polymer polyols have hydroxyl numbers of ≧20, solids contents of about 30 to about 65% by weight and a viscosity that is less than or equal to: be^[2.7c]. These comprise the reaction product of a base polyol, a preformed stabilizer and at least one ethylenically unsaturated monomer, in the presence of a free-radical polymerization initiator and at least one polymer control agent. The base polyol has a hydroxyl number of 60 to 1900, a functionality of 1 to 10, and an equivalent weight of 30 to 900.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to low viscosity polymer polyols that have a high hydroxyl number and a solids content of about 30 to about 65% by weight. This invention also relates to a process for the preparation of these novel polymer polyols. These polymer polyols have hydroxyl numbers of ≧20, solids contents of about 30 to about 65% by weight and a viscosity that is less than or equal to: be[2.7c]. These comprise the reaction product of a base polyol, a preformed stabilizer and at least one ethylenically unsaturated monomer, in the presence of a free-radical polymerization initiator and at least one polymer control agent. [0002] Polymer polyol compositions are commercial products that have found use in a variety of applications primarily as constituents in the production of polyurethanes. Polyurethanes are suitable for the production of coatings, adhesives, sealants, elastomers, and flexible, semi-flexible and rigid foams. The primary function ...

AI Technical Summary

Benefits of technology

[0013] This invention relates to low viscosity polymer polyols which are characterized by high hydroxyl numbers, and to a process for the preparation of these low viscosity polymer polyols which have high hydroxyl numbers.

Problems solved by technology

Many of these compositions possessed undesirably high viscosities for certain applications.

Polymer polyols derived from such high styrene monomer mixtures appear incapable of satisfying ever-increasing market needs, which include rigorous stability, filterability and low-viscosity requirements, and increased load-bearing characteristics in polyurethane foams.

However, an increase in the solids contents of polymer polyols is, generally, at the expense of the other properties (i.e. filterability, stability and viscosity) of the polymer polyol.

Employment of high styrene monomer mixtures and high solid content polymer polyols, by prior practices, generally resulted in undesirably high viscosity polymer polyols.

Because of increased use of sophisticated mixing systems, such as impingement systems, excessive viscosity of the polymer polyol is becoming a significant problem.