Method of tinting a plastic article

Abstract

A method of tinting a plastic article is provided. The method comprises the steps of (a) providing a plastic article comprising a thermoset or thermoplastic polymer; (b) contacting at least a portion of the surface of said plastic article with a treatment composition comprising at least one dye and water; (c) maintaining said portion of said plastic article in contact with said treatment composition for a period of time at least sufficient to form a tinted plastic article; (d) removing said tinted plastic article from contact with said treatment composition; and (e) rinsing said tinted plastic article with water to remove excess dye. The method is carried out in the absence of an organic solvent, without the need for fixing or further processing steps.

1 . A method of tinting a plastic article comprising:
 (a) providing a plastic article comprising a thermoset or thermoplastic polymer, with the proviso that the plastic article does not comprise a polymer prepared from diethyleneglycol bis allylcarbonate,   (b) contacting at least a portion of the surface of said plastic article with a treatment composition comprising at least one dye and water,   (c) maintaining said portion of said plastic article in contact with said treatment composition for a period of time at least sufficient to form a tinted plastic article;   (d) removing said tinted plastic article from contact with said treatment composition; and   (e) rinsing said tinted plastic article with water to remove excess dye,   wherein the treatment composition is characterized by the absence of an organic solvent.   
   
   
       2 . The method of  claim 1 , wherein the dye is a water-soluble liquid dye. 
   
   
       3 . The method of  claim 2 , wherein the dye is an alkyleneoxy-substituted chromophore. 
   
   
       4 . The method of  claim 1  wherein said treatment composition is maintained at a temperature of 25 to 99° C. 
   
   
       5 . The method of  claim 4 , wherein said treatment composition is maintained at a temperature of 50 to 75° C. 
   
   
       6 . The method of  claim 1  wherein said period of time is from less than 0.1 sec to 5 minutes. 
   
   
       7 . The method of  claim 6 , wherein said period of time is from 30 sec to 3 minutes. 
   
   
       8 . The method of  claim 1  wherein said plastic article is contacted with said treatment composition by at least one of:
 (I) dipping at least a portion of the surface of said plastic article into said treatment composition; and   (II) applying said treatment composition to at least a portion of the surface of said plastic article.   
   
   
       9 . The method of  claim 8  wherein said treatment composition is applied to at least a portion of the surface of said plastic article by at least one of spray application, curtain application, flow coating and spin application. 
   
   
       10 . The method of  claim 1 , wherein said thermoplastic or thermoset polymer comprises a polymer selected from the group consisting of polycarbonates, polyesters, polyester polycarbonate copolymers and blends, polyethylene glycol (PETG), polymethylmethacrylate (PMMA), polyurethanes, polyurethanes, styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), nylon, polyvinylalcohols, plasticized polyvinylchlorides and mixtures thereof. 
   
   
       11 . The method of  claim 1  wherein said treatment composition further comprises one or more surfactants. 
   
   
       12 . The method of  claim 11 , wherein the surfactant is selected from the group consisting of anionic surfactants, amphoteric surfactants, non-ionic surfactants, and mixtures thereof. 
   
   
       13 . The method of  claim 11  wherein the surfactant is selected from the group consisting of glycols. 
   
   
       14 . The method of  claim 13  wherein the surfactant is diethylene glycol. 
   
   
       15 . The method of  claim 11  wherein said surfactant is present in an amount of from 1 to 15 percent by weight, based on the total weight of said treatment composition. 
   
   
       16 . The method of  claim 1  wherein said plastic article further comprises at least one of pigments, crosslinked polymethylmethacrylate microspheres, glass microspheres and metal flakes. 
   
   
       17 . The method of  claim 1  wherein said plastic article is a molded article selected from the group consisting of shaped articles, films and sheets. 
   
   
       18 . The method of  claim 16  wherein said molded article is a shaped article selected from the group consisting of optical lenses, ophthalmic lenses, sunshade lenses, face shields, glazings and athletic shoe parts. 
   
   
       19 . The method of  claim 16  wherein the molded article is an athletic shoe part. 
   
   
       20 . The method of  claim 1  wherein said plastic article is selected from the group consisting of thermoplastic pellets and thermoplastic strands. 
   
   
       21 . The method of  claim 20  further comprising melting at least one of said treated thermoplastic pellets and said treated thermoplastic strands to form a treated molten thermoplastic composition, and introducing said treated molten thermoplastic composition into a mold, thereby forming a treated shaped molded article. 
   
   
       22 . The method of  claim 1  further comprising:
 (i) contacting said treatment composition with particulate activated carbon to form a mixture of said treatment composition and particulate activated carbon;   (ii) isolating from said mixture a substantially dye free and/or additive-free liquid comprising water;   (iii) optionally adding at least one dye to said substantially additive-free water thereby forming a further treatment composition.   
   
   
       23 . The method of  claim 1  further comprising introducing said treatment composition continuously into an immersion tank through a ring having a plurality of perforations.