Polyacetals with improved resistance to bleach
AssigneeTicona LLC
InventorVincent J. Notorgiacomo
Life of this patent
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Abstract
A molding composition exhibiting bleach resistance includes a polyoxymethylene matrix polymer, from about 0.5 to about 10 weight percent of a bleach stabilizer selected from alkali metal or alkaline earth element carbonates or phosphates and mixtures thereof dispersed in the matrix resin. A bleach co-stabilizer is selected from the group consisting of: (a) a poly(alkoxy) stabilizer; (b) a zinc oxide stabilizer; (c) a color stabilizer consisting of a mixture of calcium citrate and calcium propionate, wherein the calcium citrate is the predominant component of the color stabilizer mixture; or (d) mixtures of two or more of (a), (b) and (c). The compositions exhibit a bleach resistance index of at least 2.0.
Claims32
A molding composition exhibiting bleach resistance comprising a polyoxymethylene matrix polymer, from about 0.5 to about 10 weight percent of a bleach stabilizer selected from alkali metal or alkaline earth element carbonates or phosphates and mixtures thereof dispersed in the matrix resin and a bleach co-stabilizer selected from the group consisting of:
- (a) a poly(alkoxy) stabilizer;
- (b) a zinc oxide stabilizer;
- (c) a color stabilizer consisting of a mixture of calcium citrate and calcium propionate, wherein the calcium citrate is the predominant component of the color stabilizer mixture;
- or
- (d) mixtures of two or more of (a), (b) and (c);
- and
- wherein the composition exhibits a bleach resistance index of at least 2.0.
An injection molded part adapted for interfacing aqueous bleach compositions prepared from a composition comprising a polyoxymethylene matrix polymer, from about 0.5 to about 10 weight percent of a bleach stabilizer selected from alkali metal or alkaline earth element carbonates or phosphates and mixtures thereof dispersed in the matrix resin.
Dependencies are inferred from the claim text.