Method of dyeing a semi-finished product

Abstract

A method of dyeing a semi-finished product is disclosed. The method comprise: (a) providing a semi-finished product selected from the group consisting of powders, pellets and strands, that contain at least one thermoplastic polymer; (b) immersing said semi-finished product in a dye bath comprising, (i) at least one dye, (ii) water, (iii) at least one carrier represented by the following general formula I, (I) R 1 [O(CH 2 ) n ] m OR 2  where R 1 and R 2 independently one of the other denote H, C 1-18 -alkyl, benzyl, benzoyl or phenyl radicals which may be substituted in the aromatic ring by alkyl and/or halogen, n is 2 or 3 and m is 1 to 35, and (iv) a diol selected from at least one of linear or branched C 2 -C 20 aliphatic diols, poly(C 2 -C 4 alkylene glycol), cycloaliphatic diols having from 5 to 8 carbon atoms in the cyclic ring, monocyclic aromatic diols, bisphenols and hydrogenated bisphenols; (c) retaining said semi-finished product in said bath for a period of time sufficient to form a dyed semi-finished product; and (d) removing said dyed semi-finished product from said bath.

1 . A method of dyeing a semi-finished product selected from the group consisting of strand, pellet and powder comprising: 
 (a) providing a semi-finished product comprising at least one thermoplastic polymer;    (b) immersing said semi-finished product in a dye bath comprising, 
 (i) at least one dye,  
 (ii) water,  
 (iii) at least one carrier represented by the following general formula I,  
   (I) R 1 [O(CH 2 ) n ] m OR 2    
  where R 1  and R 2  independently one of the other denote H, C 1-18 -alkyl, benzyl, benzoyl or phenyl radicals which may be substituted in the aromatic ring by alkyl and/or halogen, n is 2 or 3 and m is 1 to 35, and  
 (iv) a diol selected from at least one of linear or branched C 2 -C 20  aliphatic diols, poly(C 2 -C 4  alkylene glycol), cycloaliphatic diols having from 5 to 8 carbon atoms in the cyclic ring, monocyclic aromatic diols, bisphenols and hydrogenated bisphenols;  
   (c) retaining said portion of said semi-finished product in said bath for a period of time at least sufficient to form a dyed semi-finished product; and    (d) removing said dyed semi-finished product from said bath.    
   
   
       2 . The method of  claim 1  wherein said thermoplastic polymer is at least one member selected from the group consisting of (co)polyesters, (co)polycarbonates, polyesterpolycarbonate copolymers, acrylonitrile-butadiene-styrene copolymers, polyamides, polyurethanes, polyalkyl(meth)acrylate and styrene copolymers.  
   
   
       3 . The method of  claim 1  wherein said dye bath comprises, 
 0.001 to 0.5 percent by weight of said dye,    65 to 75 percent by weight of water,    15 to 25 percent by weight of said carrier, and    1 to 15 percent by weight of said diol,    the percent weights being based on the total weight of said dye bath in each case.    
   
   
       4 . The method of  claim 1  wherein said dye bath is maintained at a temperature of 25 to 99° C.  
   
   
       5 . The method of  claim 1  wherein R is selected from linear or branched C 1 -C 18  alkyl, and n is 2.  
   
   
       6 . The method of  claim 5  wherein R is selected from n-butyl, i-butyl and t-butyl.  
   
   
       7 . The method of  claim 1  wherein said dye bath further comprises a surfactant selected from at least one of: anionic surfactants; amphoteric surfactants; and a non-ionic surfactant selected from at least one of poly(C 2 -C 4  alkoxylated) C 14 -C 18  unsaturated fatty acids, poly(C 2 -C 4  alkoxylated) phenol and poly(C 2 -C 4  alkoxylated) C 1 -C 9  alkyl substituted phenol.  
   
   
       8 . The method of  claim 7  wherein said surfactant is present in an amount of from 1 to 15 percent by weight, based on the total weight of the dye bath.  
   
   
       9 . The method of  claim 1  wherein said diol is a poly(C 2 -C 4  alkylene glycol) selected from diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol and mixtures thereof.  
   
   
       10 . The method of  claim 9  wherein said diol is diethylene glycol.  
   
   
       11 . The method of  claim 1  wherein said dye is selected from static dyes, photochromic dyes and combinations thereof.  
   
   
       12 . The method of  claim 11  wherein said dye is a water-insoluble static dye selected from the group consisting of azo dyes, diphenylamine dyes and anthraquinone dyes.  
   
   
       13 . The method of  claim 11  wherein said dye is a static dye, and said static dye is selected from the group consisting of disperse dyes, non-migratory static dyes and combinations thereof.  
   
   
       14 . The method of  claim 11  wherein said photochromic dye is selected from at least one of spiro(indoline)naphthoxazines, spiro(indoline)benoxazines, benzopyrans, naphthopyrans, organo-metal dithizonates, fulgides and fulgimides.  
   
   
       15 . The method of  claim 1  wherein said dye bath further comprises at least one of, UV stabilizers, optical brighteners, mold release agents, antistatic agents, thermal stabilizers, IR absorbers and antimicrobial agents.  
   
   
       16 . The method of  claim 1  wherein said semi-finished product further contains at least one member selected from the group consisting of pigments, crosslinked polymethylmethacrylate microspheres, glass microspheres and metal flakes.  
   
   
       17 . The method of  claim 1  wherein said thermoplastic polycarbonate is aromatic polycarbonate.  
   
   
       18 . The semi-finished product prepared by the method of  claim 1 .  
   
   
       19 . The strand prepared by the method of  claim 1 .  
   
   
       20 . The pellet prepared by the method of  claim 1 .  
   
   
       21 . The powder prepared by the method of  claim 1.