(per) fluoropolyether carboxylic acids and use thereof for the oleo-repellent paper sizing
AssigneeSolvay Solexis S.p.A.
InventorsAntonio Russo, Claudio Tonelli, Mario Visca
Life of this patent
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Abstract
Carboxylic acids comprising perfluoropolyether chains, of formula: T1—CFW1—O—Rf—CFW2—T2 (I) wherein T1, T2, equal to or different from each other, are selected from the group formed of —CH2—B—Y—(COOH)n, —CH(CF3) O—Y(COOH)n, —F, —CF3, —C2F5, —(C2F4)Cl, wherein B=—O— or —S—; Y=C1—C20 alkylene chain, n=1-4; with the proviso that at least one of the two end groups T1, T2 be —CH2—B—Y—(COOH)n, —CH(CF3)O—Y(COOH)n; W1, W2, equal to or different from each other, are —F or —CF3; Rf is a (per)fluoropolyoxyalkylene chain formed of one or more repeating units, statistically distributed along the chain, having a number average molecular weight in the range 500-10,000.
Claims9
A method for conferring oleorepellence to paper substrata in wet-end and size-press applications comprising the step of sizing with compounds of the formula:
- T1—CFW1—O—Rf—CFW2—T2 (I)
- or salts thereof, wherein
- T1, T2, equal to or different from each other, are selected from the group formed of—CH2—B—Y—(COOH)n, —CH(CF3)O—Y(COOH)n, —F, —CF3, —C2F5, —(C2F4)C1;B=—O— or —S—;
- Y represents a C1—C20 alkylene chain, optionally containing heteroatoms as O, N, S;
- n is an integer between 1 and 4;
- with the proviso that at least one of the two end groups T1, T2 is —CH2—B—Y—(COOH)n, —CH(CF3)O—Y—(COOH)n;
- W1, W2, equal to or different from each other, are —F or —CF3;
- Rf is a (per)fluoropolyoxyalkylene chain formed of one or more repeating units, statistically distributed along the chain, having the following structure:
- (CFXO), (CF2CF2O), (CF2CF2CF2O), (CF2CF2CF2CF2O), (CR4R5CF2CF2O), (CF(CF3)CF2O), (CF2CF(CF3)O), wherein X=F, CF3;
- R4 and R5, equal to or different from each other, are selected from H, C1, or perfluoroalkyl from 1 to 4 carbon atoms, said Rf having a number average molecular weight in the range 500-10,000.
Dependencies are inferred from the claim text.