Method for the partial coloring of plastic parts

Abstract

The invention relates to an improved method for the partial coloring, in particular for the color laser engraving, of plastic parts, in particular thermoplastic plastic parts, more particularly thermoplastic plastic parts that have a multi-layered structure, to the resulting partially colored, preferably color laser engraved, plastic parts, in particular thermoplastic plastic parts, and to a device for the partial coloring of plastic parts.

1 .- 11 . (canceled) 
     
     
         12 . A process for partial coloring, in particular color laser engraving, of plastic parts, preferably of thermoplastic plastic parts, very particularly preferably of thermoplastic plastic parts comprising a layer construction, comprising at least:
 i) producing a coloring layer b) on at least a partial area of a plastic part (A);   ii) irradiating the plastic part (A) from i) with nonionizing electromagnetic radiation (C),   wherein the partial coloring is effected substantially only at sites covered with the coloring layer b) in step i) or at sites irradiated in step ii), wherein a wavelength range of the nonionizing electromagnetic radiation (C) is chosen such that the coloring layer b) has a radiation permeability of ≥0.1% to ≤99%, preferably of ≥0.5% to ≤95%, particularly preferably of ≥0.9% to ≤93%, for a chosen radiation determined by the UV-VIS-NIR-MIR method according to DIN EN ISO/IEC 17025.   
     
     
         13 . The process as claimed in  claim 12 , wherein the plastic part (A) comprises a layer construction, wherein the layer construction comprises at least one layer of a thermoplastic plastic. 
     
     
         14 . The process as claimed in  claim 13 , wherein the layer construction comprises at least one layer comprising at least one thermoplastic plastic and
 at least one further layer comprising at least one thermoplastic plastic and at least one black pigment, preferably carbon black.   
     
     
         15 . The process as claimed in  claim 14 , comprising irradiating with focused nonionizing electromagnetic radiation (C) as in step ii) in the absence of a coloring bath before step i) and/or after step ii). 
     
     
         16 . A security document obtained by the process as claimed in  claim 12 . 
     
     
         17 . An apparatus comprising a coloring bath (B), a sheet (D) comprising one or more radiation-decoupling materials and a radiation source (E) for producing focused nonionizing electromagnetic radiation (C), wherein the coloring bath (B) preferably has a temperature of ≤99° C. to ≥−60.0° C., more preferably ≤99° C. to ≥0.0° C., more preferably of ≤70° C. to ≥10° C., particularly preferably of ≤50° C. to ≥15° C., wherein the temperature may vary in a temperature range of 100° C. or remains constant upon startup of the apparatus and in that the focused nonionizing electromagnetic radiation (C) passes through the sheet (D) comprising one or more radiation-decoupling materials before impacting a plastic part (A). 
     
     
         18 . The apparatus as claimed in  claim 17 , wherein the coloring bath (B) has a temperature of ≤99° C. to ≥−60° C., preferably of ≤99° C. to ≥0° C., more preferably of ≤70° C. to ≥10° C., particularly preferably of ≤50° C. to ≥15° C., wherein the temperature preferably remains constant upon startup of the apparatus.