Color stabilization of hydroquinone hydroxyethyl ether products
The present invention relates to the color stabilization of hydroquinone hydroxyethyl ethers by phosphite compounds containing the bis-cyclic structure of spiro phosphites, both rings being attached to the same tertiary carbon atom in the phosphite molecule.
1. A composition comprising; (a) a di-hydroxyalkylether of hydroquinone wherein each hydroxyalkyl group has one to four carbon atoms, and (b) a discoloration inhibiting effective amount of a bis cyclic phosphite compound, wherein component (b) is represented by the structural formula:
R 1 and R 2 can be aromatic ring with or without substituents
R 1 and R 2 can be any akyl or cycloalkyl group
R 1 and R 2 can be same or different.
2. The composition of claim 1 wherein said di-hydroxyalkylether of hydroquinone is a commercial grade that is at least 80% by weight pure.
3. The composition of claim 2 wherein the commercial grade has a purity of at least 90% based upon the weight of the composition.
4. The composition of claim 1 wherein R1 and R2 are moieties selected from the group consisting of stearyl, isodecyl, and combinations thereof.
5. The composition of claim 1 wherein component (b) is present in an amount of between about 0.1 percent and about five percent based upon tho weight of the composition.
6. The composition of claim 1 wherein component (b) is present in an amount of between about 0.3 percent and about two percent based upon the weight of the composition.
7. The composition of claim 1 wherein component (b) is present in an amount of between about 0.5 percent and about one patent based upon the weight of the composition.
8. A method for stabilizing a di-hydroxyalkylether of hydroquinone-containing composition against discoloration which comprises incorporating a discoloration inhibiting effective amount of a bis cyclic phosphite compound into the composition, wherein said bis cyclic phosphate has the structural formula:
R 1 and R 2 can be aromatic ring with or without substituents
R 1 and R 2 can be any akyl or cycloalkyl group
R 1 and R 2 can be same or different.
9. The method of claim 8 wherein said discoloration inhibiting effective amount is between about 0.1 percent and about five percent based upon the weight of the di-hydroxyalkylether of hydroquinone plus the bis cyclic phosphite.
10. The method of claim 8 wherein said discoloration inhibiting effective amount is between about 0.3 percent and about two percent based upon the weight of the di-hydroxyalkylether of hydroquinone plus the bis cyclic phosphite.
11. The method of claim 8 wherein said discoloration inhibiting effective amount is between about 0.5 percent and about one percent based upon the weight of the di-hydroxyalkylether of hydroquinone plus the bis cyclic phosphite.
12. The method of claim 8 wherein R1 and R2 are moieties selected from the group consisting of stearyl, isodecyl, and combinations thereof.