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. In an improved process for preparing a di-hydroxyalkylether of hydroquinone, the improvement comprising adding a discoloration inhibiting effective amount of a bis cyclic phosphite compound according to the 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
to a reaction mixture suitable for making said di-hydroxyalkylether of hydroquinone.
2. In an improved process for the color stabilization of a di-hydroxyalkylether of hydroquinone, the improvement comprising adding a discoloration inhibiting effective amount of a his cyclic phosphite compound according to the 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
to the di-hydroxyalkylether of hydroquinone.
3. A polyurethane-forming reaction mixture comprising a di-hydroxyalkylether of hydroquinone and a discoloration inhibiting effective amount of a bis cyclic phosphite compound having the 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.
4. A cast elastomer or thermoplastic elastomer made by reacting the reaction mixture of claim 3 .