Reduction of discoloration in white polyurethane foams
AssigneeMilliken & Company
InventorsMark E. Ragsdale, Philip T. Radford
Life of this patent
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Abstract
Surprisingly effective additive formulations for the reduction of highly undesirable yellowing or other discoloration of white, uncolored, polyurethane foam articles are provided. White polyurethane foam exhibits a susceptibility to yellowing and discoloration to a great extent, particularly in relatively short periods of time, than other types of polymeric articles. The inventive additives impart excellent low-discoloration properties over appreciable amounts of time of regular exposure to harmful elements, thereby according the pertinent industry a manner of providing white polyurethane foams for longer periods of time. Methods of producing such reliably white-colored polyurethane foams are also provided.
Claims20
A composition suitable for use in the manufacture of a polyurethane foam, the composition comprising:
- (a) a polyol,
- (b) a benzotriazole, the benzotriazole being present in the composition in an amount of about 0.5 to about 6.0 parts per hundred parts of the polyol (php),
- (c) a lactone-based antioxidant having a 3-phenylbenzofuran-2-one structure, the lactone-based antioxidant being present in the composition in an amount of about 0.05 to about 1.0 php,
- (d) a fourth component selected from the group consisting of:
- (i) about 0.05 to about 1.0 php of a secondary phenylamine,
- (ii) about 0.05 to about 2.0 php of a hindered phenol, and
- (iii) a combination of about 0.05 to about 1.0 php of a secondary phenylamine and about 0.05 to about 2.0 php of a hindered phenol, and
- (e) an isocyanate.
A composition comprising:
- (a) a polyol,
- (b) a benzotriazole,
- (c) a lactone-based antioxidant having a 3-phenylbenzofuran-2-one structure,
- (d) a fourth component selected from the group consisting of secondary phenylamines, hindered phenols, and combinations thereof, and
- (e) an isocyanete.
Dependencies are inferred from the claim text.