Fluorine efficient finishes for textiles
View Patent ↗An improved emulsion polymerization process for producing an oil and water repellent finish for textiles wherein the improvement comprises polymerization in an aqueous solution containing 0.1 to 4.9% by weight of dipropylene-glycol monomethyl ether acetate or propylene glycol diacetate relative to water is disclosed.
1. An improved process for producing an oil and water repellent finish for textiles which comprises emulsion polymerization of a perfluoro(meth)acrylate ester with one or more hydrophilic group-containing esters wherein the improvement comprises polymerization in an aqueous solution containing 0.1 to 4.9% by weight of dipropylene glycol monomethyl ether acetate (CH 3 O(CH 2 ) 3 O(CH 2 ) 3 OCOCH 3 ) or propylene glycol diacetate (CH 3 OCO(CH 2 ) 3 OCOCH 3 ) relative to the water, wherein the copolymer is comprised of monomers copolymerized in the following percentages by weight:
(a) from about 50% to about 85% of a monomer of formula I:
R f —CH 2 CH 2 —OC(O)—C(R)═CH 2 I
(b) from about 10% to about 25% of a monomer of formula II:
R 2 —OC(O)—C(R)═CH 2 II
(c) from 0.1% to about 5% of a monomer of the formula III
HO—CH 2 CH 2 —OC(O)—C(R)═CH 2 III
(d) from 0.1% to about 5% of a monomer of the formula IV:
H—(OCH 2 CH 2 ) m —O—C(O)—C(R)═CH 2 IV
(e) from 0.1% to about 3% of a monomer of the formula V:
HO—CH 2 —NH—C(O)—C(R)═CH 2 V
(f) and optionally, from 0% up to about 10% of vinylidene chloride (formula VI) or vinyl acetate (formula VII), or a mixture thereof:
CH 2 ═CCl 2 VI
CH 3 —(O)COCH═CH 2 VII
wherein
R f is a straight or branched-chain perfluoroalkyl group of from about 2 to about 20 carbon atoms, each R is independently H or CH 3 ; R 2 is an alkyl chain from about 2 to about 18 carbon atoms; and m is 2 to about 10.
2. The process of claim 1 wherein R f in monomer (a) of formula I is:
CF 3 CF 2 (CF 2 ) x C 2 H 4 OC(O)—C(H)═CH 2
wherein
x=6, 8, 10, 12, 14, 16, and 18 in the respective relative amounts of about 3%, 50%, 31%, 10%, 3% 2% and 1%, and said monomer has a weight average molecular weight of about 569.
3. The process of claim 1 wherein monomer (b) is stearyl (meth)acrylate.
4. The process of claim 1 wherein monomer (c) is hydroxyethyl methacrylate.
5. The process of claim 1 wherein for monomer (d) m is between about 5 and about 10.
6. The process of claim 1 wherein monomer (e) is N-methylolacrylamide.
7. The process of claim 1 wherein a blocked isocyanate extender is added after the polymerization is carried out, but prior to application to the fabric.
8. The process of claim 1 wherein a silicone softener is added after the polymerization is carried out, but prior to application to the fabric.