Working fluid compositions

Abstract

The present invention relates to a composition suitable to be used as working fluid, said composition being in the form of a solution and comprising at least one (per)fluoropolyether polymer [polymer (P)] and at least one amorphous polymer [polymer (F)].

1 . A composition (C) comprising at least one (per)fluoropolyether polymer (P) and at least one amorphous polymer (F), wherein said composition (C) is in the form of a solution. 
     
     
         2 . The composition according to  claim 1 , wherein said polymer (P) comprises a (per)fluoropolyether chain (R pf ) of formula:
   —(CFX) a O(R f )(CFX′) b —
   wherein   a and b, equal or different from each other, are equal to or greater than 1;   X and X′, equal or different from each other, are —F or —CF 3 , provided that when a and/or b are greater than 1, X and X′ are —F;   (R f ) comprises, preferably consists of, repeating units R ∘ , said repeating units being independently selected from the group consisting of:   (i) —CFXO—, wherein X is F or CF 3 ;   (ii) —CFXCFXO—, wherein X, equal or different at each occurrence, is F or CF 3 , with the proviso that at least one of X is F;   (iii) —(CF 2 ) j —CFZ—O— wherein j is an integer from 0 to 3 and Z is a group of general formula —O—R (f-a) -T, wherein R (f-a)  is a fluoropolyoxyalkene chain comprising up to ten recurring units, said recurring units being selected from: —CFXO— and CF 2 CFXO—, with each of each of X being independently F or CF 3  and T being a C 1 -C 3  perfluoroalkyl group.   
     
     
         3 . The composition according to  claim 2 , wherein said chain (R f ) is selected from chains of formula:
   —[(CF 2 CF 2 O) b1 (CF 2 O) b2 (CF(CF 3 )O) b3 (CF 2 CF(CF 3 )O) b4 ]—  (R f -I)
   wherein:   b1, b2, b3, b4, are independently integers ≥0 and are chosen so that the number average molecular weight is between 400 and 20,000;
   —[(CF 2 CF 2 O) c1 (CF 2 O) c2 (CF 2 (CF 2 ) cw CF 2 O) c3 ]—  (R f -II)
 
   wherein:   cw=1 or 2;   c1, c2, and c3 are independently integers ≥0 and are chosen so that the number average molecular weight is between 400 and 20,000;
   —[(CF 2 CF(CF 3 )O) d ]—  (R f -III)
 
   wherein:   d is an integer >0 and is chosen so that the number average molecular weight is between 400 and 20,000;
   —[(CF 2 O) c2 (CF 2 (CF 2 ) cw CF 2 O) c3 ]—  (R f -IV)
 
   wherein:   cw=1 or 2;   c2 and c3 are independently integers >0 and are chosen so that the number average molecular weight is between 400 and 20,000;
   —[(CF 2 CF 2 C(Hal*) 2 O) e1 —(CF 2 CF 2 CH 2 O) e2 —(CF 2 CF 2 CH(Hal*)O) e3 ]—  (R f -V)
 
   wherein:
 Hal*, equal or different at each occurrence, is a halogen selected from fluorine and chlorine atoms; 
 e1, e2, and e3, equal to or different from each other, are independently integers ≥0 such that the (e1+e2+e3) sum is comprised between 2 and 300. 
   
     
     
         4 . The composition according to  claim 3 , wherein said chain (R f ) is selected from chains of formulae (R f -VI-a) to (R f -VI-c):
   —[(CF 2 CF(CF 3 )O) f1 —(CF 2 O) f2 ]—  (R f -VI-a)
   wherein   f1 and f2, are independently integers ≥0 and are chosen so that the number average molecular weight is between 400 and 20,000;
   —(CF(CF 3 )CF 2 O) n —  (R f -VI-b)
 
   wherein   f3 is an integer higher than 0, and is chosen so that the number average molecular weight is between 400 and 20,000, preferably between 1,000 and 10,000;
   —(CF 2 CF 2 CF 2 O) f4 —  (R f -VI-c)
 
   wherein   f4 is an integer higher than 0, and is chosen so that the number average molecular weight is between 400 and 20,000.   
     
     
         5 . The composition according to  claim 1 , wherein said polymer (F) is selected from the group consisting of amorphous polymers characterized by a glass transition temperature (T g ) in the range from −100° C. to 250° C., measured according to ASTM D3418. 
     
     
         6 . The composition according to  claim 5 , wherein said polymer (F) is selected from the group consisting of:
 styrene polymers and co-polymers;   vinyl polymers and co-polymers;   acrylic polymers and co-polymers;   (per)fluoropolymers;   polyesters;   polyamideimide (PAI) and polyetherimide (PEI);   polyethers;   sulphur containing polymers; and   polyurethane (TPU), fluorinated polyurethane and acrylonitrile polymers.   
     
     
         7 . The composition according to  claim 6 , wherein said polymer (F) is a perfluoropolymer. 
     
     
         8 . The composition according to  claim 7 , wherein said polymer (F) is a perfluoropolymer comprising recurring units derived from at least one perfluorinated monomer selected from the group consisting of:
 (A) cyclic monomers complying with one of the following formulae (A1) to (A3):   
       
         
           
           
               
               
           
         
          wherein each of R f4 , R f5 , R f6 , equal to or different from each other, is independently a fluorine atom or a C 1 -C 6  perfluoroalkyl group, optionally comprising one or more oxygen atom; 
       
       
         
           
           
               
               
           
         
          wherein n is 1 or 2; 
       
       
         
           
           
               
               
           
         
          wherein n is 1 or 2; 
         (B) C 2 -C 8  perfluoroolefins, such as tetrafluoroethylene (TFE) and hexafluoropropene (HFP); 
         (C) CF 2 ═CFOR f1 , wherein Rn is selected from:
 (R f i*) C 1 -C 6  perfluoroalkyl group and 
 (R f i**) —CF 2 OR f2    
 wherein 
 t is an integer equal to 1 or 2 and 
 R f2  is a linear or branched C 1 -C 6  perfluoroalkyl group, a cyclic C 5 -C 6  perfluoroalkyl group, or a linear or branched C 1 -C 12  perfluorooxyalkyl group comprising one or more ether groups. 
 
       
     
     
         9 . The composition according to  claim 8 , wherein said polymer (F) comprises recurring units derived from tetrafluoroethylene (TFE) and from at least one perfluorinated monomer different from TFE [co-monomer (F)]. 
     
     
         10 . The composition according to  claim 9 , wherein said at least one co-monomer (F) is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         wherein each of R f4 , R f5 , R f6 , equal to or different from each other, is independently a fluorine atom or a C 1 -C 6  perfluoroalkyl group, optionally comprising one or more oxygen atom; 
       
       
         
           
           
               
               
           
         
         wherein n is 1 or 2; 
       
       
         
           
           
               
               
           
         
         wherein n is 1 or 2; and
 combinations thereof; 
 
         or from the group consisting of: 
         (C) CF 2 ═CFOR f1 , wherein Rn is selected from:
 (R f1 *) —CF 3 , —C 2 F 5 , and —C 3 F 7 , and combinations thereof; 
 (R f1 **) —CF 2 OR f2 , wherein R f2  is a linear or branched C 1 -C 6  perfluoroalkyl group, cyclic C 5 -C 6  perfluoroalkyl group, or a linear or branched C 2 -C 6  perfluoroxyalkyl group; and 
 combinations thereof. 
 
       
     
     
         11 . The composition according to  claim 8 , wherein said polymer (F) essentially consists of recurring units of formula: 
       
         
           
           
               
               
           
         
         wherein each of R f4 , R f5 , R f6 , equal to or different from each other, are as defined is independently a fluorine atom or a C 1 -C 6  perfluoroalkyl group, optionally comprising one or more oxygen atom. 
       
     
     
         12 . The composition according to  claim 8 , wherein said polymer (F) comprises recurring units of formula:
   CF 2 ═CFO—CF 2 O—CF 2 CF 3  (MOVE1);  (D**i)
     CF 2 ═CFO—CF 2 O—CF 2 CF 2 OCF 3  (MOVE2);  (D**ii)
     CF 2 ═CFO—CF 2 O—CF(CF 3 )OCF 3  (MOVE2a);  (D**iii)
     CF 2 ═CFO—CF 2 O—CF 3  (MOVE3);  (D**iv)
   and combinations thereof.   
     
     
         13 . The composition according to  claim 1 , wherein said composition (C) comprises at least one polymer (P) in an amount higher than 50 wt. % and up to 99.99 wt. % based on the total weight of said composition (C). 
     
     
         14 . The composition according to  claim 1 , wherein said composition (C) comprises at least one polymer (F) in an amount of from 0.01 to less than 50 wt. % based on the total weight of said composition (C). 
     
     
         15 . A hydraulic fluid, damping media; lubricant or release agent comprising the composition (C) of  claim 1 . 
     
     
         16 . A method for increasing the viscosity of at least one polymer (P) as defined in  claim 3 , said method comprising contacting said at least one polymer (P) with at least one polymer (F), wherein polymer (F) is an amorphous polymers characterized by a glass transition temperature (T g ) in the range from −100° C. to 250° C., measured according to ASTM D3418. 
     
     
         17 . The composition according to  claim 3 , wherein:
 chain (R f ) is (R f -I), b1 is 0, and b2, b3, b4, are independently integers ≥0 and are chosen so that the number average molecular weight is between 1,000 and 10,000, with the ratio b4/(b2+b3) being ≥1; or   chain (R f ) is (R f -II) and c1, c2, and c3 are independently integers >0 and are chosen so that the number average molecular weight is between 1,000 and 10,000, with the ratio c3/(c1+c2) being less than 0.2; or   chain (R f ) is (R f -III) and d is an integer >0 and is chosen so that the number average molecular weight is between 1,000 and 10,000; or   chain (R f ) is (R f -IV) and c2 and c3 are independently integers >0 and are chosen so that the number average molecular weight is between 1,000 and 10,000; with the ratio c3/c2 being less than 0.2; or   chain (R f ) is (R f -V) and each -Hal* is a fluorine atom.   
     
     
         18 . The composition according to  claim 4 , wherein
 chain (R f ) is (R f -VI-a) and f1 and f2, are independently integers greater than 0 and are chosen so that the number average molecular weight is between 1,000 and 10,000, with the ratio f1/f2 being ≥1; or   chain (R f ) is (R f -VI-b) and f3 is an integer higher than 0, and is chosen so that the number average molecular weight is between 1,000 and 10,000; or   chain (R f ) is (R f -VI-c) and f4 is an integer higher than 0, and is chosen so that the number average molecular weight is between 1,000 and 10,000.   
     
     
         19 . The composition according to  claim 1 , wherein said composition (C) comprises at least one polymer (P) in an amount from 60 wt. % to about 99.95 wt. %, based on the total weight of said composition (C). 
     
     
         20 . The composition according to  claim 1 , wherein said composition (C) comprises at least one polymer (F) in an amount of from 0.05 to 40 wt. %, based on the total weight of said composition (C).