Composition and process for weighting silk

Abstract

A composition for treatment of silk and a process using said composition are described. In particular a silk loading or weighting process is described, which uses an aqueous composition comprising metal salts and organic monomers.

1 . An aqueous composition for silk loading comprising at least:
 a) from 0.1 to 200 g/l of one or more vinyl monomers preferably selected from (meth)acrylamides, (meth)acrylonitriles, alkyl(meth)acrylates, hydroxy alkyl (meth)acrylates and (poly)ethylene glycol (meth)acrylates;   b) from 0.01 a 20 g/l of a radical initiator,   c) from 0.015 to 36 g/l of a second redox initiator selected from metal salts   wherein said one or more vinyl monomers comprise from 31% to 100% in weight, with respect to the overall weight of vinyl monomers, of a hydroxy alkyl (meth)acrylate and/or wherein the aqueous composition has a pH comprised between 3.3 and 6.8.   
     
     
         2 . The aqueous composition of  claim 1  having a pH comprised between 2 and 7, preferably between 3.3 and 6.8, more preferably between 3.5 and 6, still more preferably between 4 and 5. 
     
     
         3 . The aqueous composition of  claim 1  wherein the one or more vinyl monomers of the component a) are selected from MMA, MAA and HEMA, the component b) is selected from ammonium persulphate (APS), potassium persulphate (PPS), 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis(2-methyl-propionamidine)dichlorhydrate (ADC), preferably between ammonium persulphate and potassium persulphate, and the component c) is selected from iron sulphate, aluminium sulphate and copper sulphate. 
     
     
         4 . The aqueous composition of  claim 1  comprising at least:
 from 10 to 100 g/l, from 15 to 50 g/l, preferably from 30 to 40 g/l, of component a), from 0.1 to 5 g/l, preferably from 0.1 to 1 g/l of component b), and from 0.1 g/l to 7 g/l, preferably from 0.15 to 2 g/l of component c). 
 
     
     
         5 . The aqueous composition of  claim 1  wherein said one or more vinyl monomers comprise from 61% to 100% in weight of a hydroxy alkyl (meth)acrylate, preferably HEMA, with respect to the overall weight of vinyl monomers. 
     
     
         6 . The aqueous composition of  claim 1  comprising at least:
 a) from 30 to 40 g/l of HEMA; 
 b) from 0.1 to 1 g/l of APS, 
 c) from 0.15 to 2 g/l of copper sulphate 
 
       wherein said aqueous composition has a pH comprised between 4 and 5. 
     
     
         7 . A process for silk loading comprising:
 supplying the silk,   supplying an aqueous composition of  claim 1 ,   immersing the silk in the composition,   heating the composition in which the silk is immersed to a temperature comprised between 60° C. and 90° C. for a time preferably comprised between 5 and 120 minutes, more preferably between 15 and 45 minutes, still more preferably between 20 and 35 minutes,   removing, washing and drying the silk.   
     
     
         8 . A process for silk loading, comprising:
 supplying the silk,   supplying an aqueous composition comprising one or more vinyl monomers a) as defined in  claim 1 ,   immersing the silk in the composition,   adding components b) and c) to the composition and bringing the pH to a value comprised between 2 and 7, to give a composition of any one of claims from 1 to 6,   heating the composition in which the silk is immersed to a temperature comprised between 60° C. and 90° C. for a time preferably comprised between 5 and 120 minutes, more preferably between 15 and 45 minutes, still more preferably between 20 and 35 minutes,   removing, washing and drying the silk.   
     
     
         9 . The process of  claim 7 , wherein the pH is comprised between 3.3 and 6.8, more preferably between 3.5 and 6, still more preferably between 4 and 5. 
     
     
         10 . The process of  claim 7 , wherein the temperature is comprised between 65° C. and 75° C., more preferably between 67° C. and 72° C. 
     
     
         11 . The process of  claim 7  wherein said one or more vinyl monomers comprise from 61% to 100% in weight of a hydroxy alkyl(meth)acrylate, preferably HEMA, with respect to the overall weight of vinyl monomers. 
     
     
         12 . The process of  claim 7  wherein said vinyl monomer is HEMA, said component b) is ammonium persulphate and aid component c) is copper sulphate. 
     
     
         13 . The process of  claim 7  wherein the percentage of loading is greater than 50%, preferably greater than 70%, more preferably greater than 90%. 
     
     
         14 . The process of  claim 7  wherein the percentage of grafting is greater than 80%, preferably greater than 90%, more preferably greater than 95%. 
     
     
         15 . The process of  claim 7  wherein said component a) is HEMA in a quantity comprised between 0.1 and 200 g/l; said component b) is ammonium persulphate in a quantity comprised between 0.1 and 1 g/l; said component c) is copper sulphate in a quantity comprised between 0.15 and 3 g/l; said pH is comprised between 4 and 5; said temperature is comprised between 65 and 75° C. and said time is comprised between 20 and 45 minutes. 
     
     
         16 . The process of  claim 7  wherein the bath ratio is less than 100 l/Kg, preferably less than 50 l/Kg, more preferably less than 30 l/Kg, still more preferably less than 20 l/Kg. 
     
     
         17 . A silk loaded according to  claim 7 . 
     
     
         18 . The silk of  claim 17 , characterised by a titre of greater than 8.5 tex, preferably greater than 12 tex, more preferably greater than 19 tex. 
     
     
         19 . The silk of  claim 17 , characterised by an ultimate tensile strength of greater than 250 cN, preferably greater than 300 cN. 
     
     
         20 . The silk of  claim 17  characterised by an average elongation at break of greater than 12.5%, preferably greater than 16%. 
     
     
         21 . A silk loaded with products of polymerisation of vinyl monomers characterised by a titre of greater than 8.5 tex, preferably greater than 12 tex, more preferably greater than 19 tex and by one or more of the following characteristics:
 an average ultimate tensile strength of greater than 250 cN, preferably greater than a 300 cN   an average elongation at break of greater than 12.5%, preferably greater than 16%   a degree of whiteness of greater than 60%, preferably greater than 65%.   
     
     
         22 . The silk of  claim 21 , containing the products of polymerisation of one or more vinyl monomers which comprise from 61% to 100% in weight with respect to the overall weight of vinyl monomers, of a hydroxy alkyl (meth)acrylate, preferably HEMA.