Decolorization of hydroxy-containing methacrylate homopolymers and copolymers
First Claim
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1. A process for decolorizing homo- and co-polymers of hydroxy-containing methacrylates of the formula ##STR2## wherein n>
- 2,m>
4 and b>
1;
wherein said homo- and co-polymers are prepared in the presence of a chain transfer catalyst;
comprising the steps of exposing the polymers to;
(a) an acid having a pKa less than about 2;
(b) a chelating bidentate nitrogen ligand containing a fragment of the formula alkylidene(NR2)x (imidazolyl)ywherein y>
1 and (y+x)>
2;
said alkylidene is C2 to C10 ;
each R is independently H or C1 to C10 alkyl;
and(c) a polar absorbent medium.
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Abstract
This invention relates to a process whereby hydroxy-containing methacrylate homo- and copolymers are decolorized by the addition of a strong acid and a chelating bidentate nitrogen ligand, with subsequent filtering through a polar adsorption medium.
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Citations
15 Claims
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1. A process for decolorizing homo- and co-polymers of hydroxy-containing methacrylates of the formula ##STR2## wherein n>
- 2,m>
4 and b>
1;
wherein said homo- and co-polymers are prepared in the presence of a chain transfer catalyst;comprising the steps of exposing the polymers to; (a) an acid having a pKa less than about 2; (b) a chelating bidentate nitrogen ligand containing a fragment of the formula alkylidene(NR2)x (imidazolyl)y wherein y>
1 and (y+x)>
2;said alkylidene is C2 to C10 ; each R is independently H or C1 to C10 alkyl; and (c) a polar absorbent medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- 2,m>
Specification