METHOD FOR THE PARTIAL COLORING OF PLASTIC PARTS

Abstract

The present invention concerns a method for the partial dyeing, in particular for the colour laser engraving, of plastic components, in particular thermoplastic plastic components, more particularly thermoplastic plastic components, comprising a layer construction as well as the resulting partially dyed, preferably colour laser engraved plastic components, in particular thermoplastic plastic components.

Claims

1.-14. (canceled)

15. A method for the partial dyeing of plastic components, including the steps i) submerging a plastic component in a dye bath, ii) possibly the heating of the dye bath, iii) irradiation of the plastic component from i) and possibly ii) with focussed non-ionising electromagnetic radiation, preferably focussed non-ionising electromagnetic radiation with a wavelength within a range of 0.1 m to 1 mm, more preferably within a range of 0.15 m to 20 m, most preferably with laser radiation within a range of 0.15 m to 20 m, wherein the partial dyeing substantially happens only at the points irradiation during step iii).

16. The method according to claim 15, wherein step iii) is carried out by means of laser irradiation within a wavelength range of 0.15 m to 20 m.

17. The method according to claim 15, wherein the dye bath comprises at least one colorant, preferably at least a dye, or mixtures of the same.

18. The method according to claim 15, wherein the dye bath comprises at least one dye of the group of solvent dyes and/or disperse dyes according to the Colour Index classification or mixtures of these dyes.

19. The method according to claim 15, wherein the submersion depth of the plastic component in step i) is 120 mm, preferably 0.01 to 100 mm, particularly preferably 0.1 to 20 mm.

20. The method according to claim 15, wherein the dye bath comprises: a) water and/or an organic solvent, b) at least one colorant, preferably at least one dye, particularly preferably at least one dye of the solvent dyes and/or disperse dyes according to the Colour Index classification or a mixture of these dyes.

21. The method according to claim 20, wherein the dye bath further comprises: c) at least one solvent with the structure formula (I)
R[(O(CH.sub.2).sub.m).sub.n]OH(I), where R is an ethyl, propyl or butyl radical, m is 2, 3 or 4 and n is 1, 2 or 3, under the stipulation that, if R is butyl, m is 2 or 4, d) at least one levelling agent with the structure formula (II):
H[(O(CH.sub.2).sub.m).sub.n]OH(II), where m is 2, 3 or 4 and n is 1, 2 or 3.

22. The method according to claim 21, wherein the components a) to d) are included in the following quantities, related to the total weight of the dye solution: a) 50 to 99.99 wt. %, preferably 62.5 to 90.0 wt. %, particularly preferably 65.0 to 85.0 wt. %, b) 0.01 to 15.0 wt. %, preferably 0.1 to 5.0 wt. %, particularly preferably 0.2 to 4.0 wt. %, c) 0 to 35.0 wt. %, preferably 1.0 to 30.0 wt. %, particularly preferably 5.0 to 25.0 wt. %, d) 0 to 30.0 wt. %, preferably 1.0 to 20.0 wt. %, particularly preferably 3.0 to 15.0 wt. %.

23. The method according to claim 15, wherein the plastic component comprises at least one thermoplastic plastic selected from the group consisting of one or more polycarbonate(s) or copolycarbonate(s) on a basis of diphenols, poly- or copolyacrylate(s) and poly- or copolymethacrylate(s), poly- or copolymer(s) with styrol, thermoplastic polyurethane(s), as well as polyolefine(s), poly- or copolycondensate(s) of terephthalic acid, poly- or copolycondensate(s) of naphthalindicarboxylic acid, poly- or copolycondensate(s) of at least one cycloalkyldicarboxylic acid, mixtures of the above mentioned, or their blends.

24. The method according to claim 23, wherein the plastic component is moulded component.

25. The method according to claim 15, wherein the plastic component is a layer construction including at least one layer of a thermoplastic plastic selected from polymerisates of ethylenically unsaturated monomers and/or polycondensates of bifunctionally reactive compounds, preferably one or more polycarbonate(s) or copolycarbonate(s) on a basis of diphenols, poly- or copolyacrylate(s) and poly- or copolymethacrylate(s), poly- or copolymer(s) with styrol, thermoplastic polyurethane(s) as well as polyolefine(s), poly- or copolycondensate(s) of terephthalic acid, poly- or copolycondensates of naphthalindicarboxylic acid, poly- or copolycondensate(s) of at least one cycloalkyldicarboxylic acid, mixtures of these or their blends, particularly preferably one or more polycarbonate(s) or copolycarbonate(s) on a basis of diphenols or blends containing at least one polycarbonate or copolycarbonate.

26. The method according to claim 25, wherein the layer construction comprises a further layer, including at least one thermoplastic plastic and at least one laser-sensitive additive, preferably a black pigment, particularly preferably carbon black.

27. The method according to claim 15, wherein the method further comprises the steps: iv) removal of the dye bath, v) irradiation with the same laser beam as during step iii).

28. Plastic article according to claim 15.

Description

EXAMPLES

[0119] The plastic component to be dyed is a plastic film made of polycarbonate (Makrofol ID 4-4-010207 200 m opaque white) from company Covestro Deutschland AG.

Example 1: Composition of the Dye Bath

[0120] 69.31 wt. % water

[0121] 0.99 wt. % Macrolex Blue 3R (dye from company Lanxess AG, Germany)

[0122] 19.8 wt. % ethyleneglycolbutylether (EGBE), (solvent, The Dow Chemical Company)

[0123] 9.9 wt. % parts diethyleneglycol (DEG), (levelling agent, Merck KGaA)

[0124] Method for Colour Laser Engraving

[0125] A NdYAG laser from company Foba was used for laser irradiation, namely Model D84 with a laser capacity of approx. 7.5 watt, a laser frequency of 8 KHz during pulsed operation and a current of 8 A. The advancing speed of the laser, the submersion depth and the temperature of the dye bath are listed in Table 1.

[0126] The Makrofol ID 4-4-010207 200 m opaque white film was submersed in the dye bath according to the information in Table i. The dye bath with the film was the placed on the workpiece carrier of a Foba D84S laser system. The focus of the laser was adjusted to the film surface. Information regarding the submersion depth can be found in Table 1. Submersion depth should be understood in the sense of this invention as the penetration depth of the radiation used into the dye bath up to the surface of the plastic component to which the partial dyeing is to be applied. it was irradiated with the laser beam.

TABLE-US-00001 TABLE 1 Conditions of colour laser engraving Example 2 Example 3 Dye bath Example 1 Example 1 Temperature of dye bath 40 C. 40 C. Submersion depth 1 mm 1 mm Advancing speed 100 mm/s 500 mm/s

[0127] It was possible to show with both of these examples that an intense blue dyeing in the form of the incoming laser beam appeared on the film at the points that were irradiated with the laser beam. The areas of the film that were not irradiated with the laser were substantially not dyed. An intense dyeing of the film was observed at an advancing speed of 100 mm/s.