Amide-linked perfluoropolyether thiol compounds and processes for their preparation and use

Abstract

A perfluoropolyether thiol compound comprises a perfluoropolyether segment, at least one mercapto group (—SH), and at least one intervening divalent carbonylimino moiety (—C(═O)—NR—, wherein R is hydrogen or alkyl). The compound can be produced, for example, by a ring-opening reaction of thiolactones with perfluoropolyether-substituted, primary or secondary amines. The compound can be used, for example, as a polymerization chain transfer agent, as an intermediate for the preparation of functional group-containing fluorochemical derivatives such as disulfides, and as a fluorinated surface treatment.

We claim: 
     
         1 . A process for preparing a perfluoropolyether thiol compound comprises (a) providing at least one thiolactone compound; (b) providing at least one perfluoropolyether-substituted, primary or secondary amine compound; and (c) combining the thiolactone compound and the perfluoropolyether-substituted, primary or secondary amine compound. 
     
     
         2 . The process of  claim 1 , wherein said thiolactone compound is selected from thiolactone compounds having from 5 to 8 ring members, and mixtures thereof. 
     
     
         3 . The process of  claim 1 , wherein said thiolactone compound is gamma-butyrothiolactone. 
     
     
         4 . The process of  claim 1 , wherein said perfluoropolyether-substituted, primary or secondary amine compound is amide-linked. 
     
     
         5 . A process comprising polymerizing at least one vinyl monomer in the presence of at least one polymerization initiator and at least one perfluoropolyether thiol compound of formula (II) above, wherein R is hydrogen or alkyl; Q is a divalent organic linking group selected from —CH 2 CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —S—C(═O)—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[O—C(═O)]—CH 2 CH 2 —, —(CH 2 CH 2 O) 2 —[C(═O)]—CH 2 CH 2 —, and combinations thereof; and R f ′, a, x, and y are as defined in  claim 1 . 
     
     
         6 . A process comprising oxidizing at least one perfluoropolyether thiol compound of formula (II) above, wherein R is hydrogen or alkyl; Q is a divalent organic linking group selected from —CH 2 CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —S—C(═O)—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[O—C(═O)]—CH 2 CH 2 —, —(CH 2 CH 2 O) 2 —[C(═O)]—CH 2 CH 2 —, and combinations thereof; and R f ′, a, x, and y are as defined in  claim 1 . 
     
     
         7 . A perfluoropolyether disulfide compound comprising two perfluoropolyether segments and at least one pair of intervening divalent carbonylimino moieties that are linked by, and bonded to, a central divalent dithio moiety; wherein said compound is a disulfide-linked dimer of a perfluoropolyether thiol compound of formula (II) above, wherein R is hydrogen or alkyl; Q is a divalent organic linking group selected from —CH 2 CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —S—C(═O)—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[O—C(═O)]—CH 2 CH 2 —, —(CH 2 CH 2 O) 2 —[C(═O)]—CH 2 CH 2 —, and combinations thereof; and R f ′, a, x, and y are as defined in  claim 1 . 
     
     
         8 . The compound of  claim 7 , wherein said compound comprises two monovalent perfluoropolyether segments and one pair of said intervening carbonylimino moieties. 
     
     
         9 . A process comprising
 (a) providing at least one substrate having at least one surface;   (b) providing at least one treatment composition comprising
 (1) at least one perfluoropolyether thiol compound of formula (II) above, wherein R is hydrogen or alkyl, Q is a divalent organic linking group selected from —CH 2 CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —S—C(═O)—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[O—C(═O)]—CH 2 CH 2 —, —(CH 2 CH 2 O) 2 —[C(═O)]—CH 2 CH 2 —, and combinations thereof, and R f ′, a, x, and y are as defined in  claim 1 , 
 (2) at least one perfluoropolyether disulfide compound of  claim 7 , or 
 (3) a combination thereof; and 
   (c) applying said treatment composition to at least a portion of at least one said surface of said substrate.   
     
     
         10 . An article comprising at least one substrate having at least one surface bearing on at least a portion thereof at least one treatment composition comprising
 (a) at least one perfluoropolyether thiol compound of formula (II) above, wherein R is hydrogen or alkyl, Q is a divalent organic linking group selected from —CH 2 CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 —[N(CH 3 )—C(═O)]—CH 2 CH 2 CH 2 —S—C(═O)—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[NH—C(═O)]—CH 2 CH 2 CH 2 —, —CH 2 CH 2 —[O—C(═O)]—CH 2 CH 2 —, —(CH 2 CH 2 O) 2 —[C(═O)]—CH 2 CH 2 —, and combinations thereof, and R f ′, a, x, and y are as defined in  claim 1 ,   (b) at least one perfluoropolyether disulfide compound of  claim 7 ,   (c) at least one product of reaction of said perfluoropolyether thiol compound or said perfluoropolyether disulfide compound with said substrate, or   (d) a combination thereof.