METHOD FOR PRODUCING VIRTUAL THREE-DEMENSIONAL PATTERNS IN MOLDED BODIES MADE OF PLASTIC

Abstract

The present invention relates to a two-step process for the production of virtual three-dimensional patterns in polymeric mouldings with the aid of injection-moulding processes, in particular a process in which a conventional injection-moulding process are combined with a reactive injection-moulding process in a suitable manner in order to obtain polymeric mouldings having a virtual three-dimensional pattern which is visible on one surface and is formed by flake-form effect pigments, and to the polymeric mouldings produced by means of this process and to the use thereof, in particular for decorative purposes.

Claims

1. Injection-moulding process for the generation of virtual three-dimensional patterns in polymeric mouldings, where in a first process step in an injection mould which has injection-mould parts A and B which can be separated from one another and which have an inside surface A′ and B′ respectively and together form an interior cavity, where inside surface A′ has bumps and/or pits on a base area which form a three-dimensional pattern, with the injection mould opened a thermoplastic film pigmented with flake-form effect pigments is fixed to surface A′, the injection mould is closed, a thermoplastic melt is introduced into the interior cavity between the thermoplastic film and surface B′ of injection mould part B, and the injection mould is heated or cooled with formation of a polymeric base moulding, where the base moulding has a body comprising a thermoplastic and a surface comprising the thermoplastic film which has a three-dimensional pattern comprising bumps and/or pits which is virtually enhanced by alignment of the flake-form effect pigments parallel to the bumps and/or pits in the thermoplastic film, and where in a second process step the polymeric base moulding is introduced into an injection mould having an interior cavity in such a way that the base moulding's outside surface, which has the thermoplastic film with bumps and/or pits, faces the interior cavity, the injection mould is closed, and a mixture of at least two flowable components which react with one another with polymerisation is introduced into the interior cavity remaining, at least partly flooding the thermoplastic film, where the flowable components solidify with one another by polymerisation to form a transparent plastic and the thermoplastic film forms a strong and positive bond to this plastic, and the injection mould is heated or cooled and subsequently the resultant moulding, which has an outside surface comprising the transparent plastic and a virtual three-dimensional pattern formed by the flake-form effect pigments on at least part of this outside surface, is demoulded or removed.

2. Process according to claim 1, characterised in that the thermoplastic film has been mass-coloured with flake-form effect pigments.

3. Process according to claim 1, characterised in that the three-dimensional pattern is a macroscopic pattern in the form of a pictorial object, an alphanumeric motif, a line and/or dot pattern, a logo, a code or an abstract pattern.

4. Process according to claim 1, characterised in that the flake-form effect pigments are selected from the group pearlescent pigments, interference pigments, metal-effect pigments, flake-form functional pigments, flake-form structured pigments, or a mixture thereof.

5. Process according to claim 1, characterised in that the flake-form effect pigments have a particle size in the range from 5 to 250 μm and an aspect ratio of at least 2.

6. Process according to claim 1, characterised in that the flake-form effect pigments are present in the pigmented thermoplastic film in an amount of 0.1 to 20% by weight, based on the total weight of the pigmented film.

7. Process according to claim 1, characterised in that, in addition to the flake-form effect pigments, the pigmented thermoplastic film also comprises further organic or inorganic coloured pigments, dyes and/or fillers.

8. Process according to claim 1, characterised in that the thermoplastic melt comprises particulate or soluble colourants.

9. Process according to claim 1, characterised in that the body of the base moulding is transparent, translucent or opaque.

10. Polymeric moulding which has a thermoplastic base moulding and a transparent surface layer located thereon comprising a transparent plastic formed by reactive polymerisation of at least two flowable components, where the thermoplastic base moulding and the transparent surface layer have an interface with one another which is formed by a thermoplastic film pigmented with flake-form effect pigments which has a film surface which faces the transparent surface of the polymeric moulding and has a three-dimensional pattern comprising bumps and/or pits, which is virtually enhanced by alignment of the flake-form effect pigments parallel to the bumps and/or pits in the thermoplastic film and is visible through the transparent surface layer, produced by a process according to claim 1.

11. Polymeric moulding according to claim 10, characterised in that the thermoplastic base moulding has a body which comprises particulate and/or soluble colourants.

12. Polymeric moulding according to claim 11, characterised in that the body is transparent, translucent or opaque.

13. A method comprising incorporating a polymeric moulding according to claim 10 as decorative and/or the labelling element or part of durable consumer goods.

14. A method according to claim 13, characterised in that the durable consumer goods are packaging, products in the electrical and electronics industry, domestic appliances, furniture, clothing, bags, shoes, sports articles, vehicles or vehicle parts.

Description

EXAMPLE 1

[0125] A film (PC/ABS, Bayblend® T 65 HI, product from Covestro) having a content of 2.0% by weight of Colorstream® F 10-51 Lava Red (flake-form effect pigment based on SiO.sub.2 substrates, particle size 5-50 μm, product from Merck KGaA) having a thickness of approx. 300 μm is produced in a size of 100×150 mm by means of an injection-moulding process.

[0126] The film mass-coloured with the effect pigment is laid in the injection mould of an Arburg Allrounder 320 M injection-moulding machine, whose first inside surface, which faces the cavity of the injection mould, has been provided with a three-dimensional structure in the form of the mirror image of a logo. The film is electrostatically fixed to this inside surface.

[0127] After the mould has been closed, a plastic melt (PC/ABS, Bayblend® T 65 HI, product from Covestro AG) is injected into the remaining cavity between the pigmented thermoplastic film and the other inside surface of the injection mould which has not been provided with the three-dimensional structure (nozzle side). The injection operation is carried out at a temperature in the range from 180 to 260° C. and a pressure in the range from 300 to 900 bar. The film positively bonds to the body formed to give a polymeric base moulding which has on one of its surfaces a three-dimensional pattern in the form of a logo in a glossy surface pigmented with effect pigments. Since the logo has various pits of only about 100-600 μm each, its actual three-dimensional structure is only weakly perceptible optically, but can be felt haptically.

[0128] The base moulding produced beforehand is applied to an inside surface of the injection mould in a suitable RIM injection moulding tool in such a way that the logo on the film surface of the base moulding faces the interior cavity of the injection mould. The mould is then closed. A reactive mixture (2-component PUR system) is introduced into the cavity still remaining between the pigmented film surface and the free inside surface of the injection mould and allowed to cure. The reactive mixture used is a mixture of 49% by weight of component 1, consisting of Desmophen® XP2488 (24.15% by weight), Desmophen® C1100 (24.15% by weight), Dabco® T-12 (0.5% by weight) and FC 983 (0.2% by weight), and 51% by weight of component 2, consisting of Desmodur® N-3600, all products from Bayer MaterialScience.

[0129] After the cooling operation and opening of the mould, a moulding is obtained whose first outside surface exhibits an area, giving the impression of lying behind glass, having a uniformly strong red gloss with a finely structured virtual three-dimensional pattern located therein in the form of a logo which is formed by the flake-form effect pigments in the film and which corresponds to the motif of the logo on the surface of the base moulding. The other principal surface of the moulding is flat, translucent and has a pale colour.

EXAMPLE 2

[0130] A film (PC/ABS, Novodur Ultra 4105, product from Ineos Styrolution Group GmbH) having a content of 2.0% by weight of Miraval® 5411 (flake-form effect pigment based on borosilicate substrates, particle size 20-200 μm, product from Merck KGaA) and 0.2% by weight of PV Fast Blue B2G01 (product from Clariant International Ltd.) having a thickness of approx. 300 μm is produced in a size of 100×150 mm by means of an injection-moulding process.

[0131] The film mass-coloured with the effect pigment is laid in the injection mould of an Arburg Allrounder 320 M injection-moulding machine, whose first inside surface, which faces the cavity of the injection mould, has been provided with a three-dimensional structure in the form of the mirror image of a logo. The film is electrostatically fixed to this inside surface.

[0132] After the mould has been closed, a plastic melt (ABS, Terluran® GP22, product from BASF, having a carbon black content of 0.5% by weight) is injected into the cavity remaining between the pigmented thermoplastic film and the other inside surface of the injection mould which has not been provided with the three-dimensional structure (nozzle side). The injection operation is carried out at a temperature in the range from 180 to 260° C. and a pressure in the range from 300 to 900 bar. The film positively bonds to the body formed to give a polymeric base moulding which has on one of its surfaces a three-dimensional pattern in the form of a logo in a glossy-blue surface pigmented with effect pigments. Since the logo has various pits of only about 100-600 μm each, its actual three-dimensional structure is only weakly perceptible optically, but can be felt haptically.

[0133] The base moulding produced beforehand is applied to an inside surface of the injection mould in a suitable RIM injection mould tool in such a way that the logo on the film surface of the base moulding faces the interior cavity of the injection mould. The mould is then closed. A reactive mixture (2-component PUR system) is introduced into the cavity still remaining between the pigmented film surface and the free inside surface of the injection mould and allowed to cure. The reactive mixture used is the mixture according to Example 1.

[0134] After the cooling operation and opening of the mould, a moulding is obtained whose first outside surface exhibits an area, giving the impression of lying behind glass, having a uniformly blue gloss with a partly glittery, finely structured virtual three-dimensional pattern with bright gloss located therein in the form of a logo which is formed by the flake-form effect pigments in the film and which corresponds to the motif of the logo on the surface of the base moulding. The other principal surface of the moulding is flat, opaque and has a dark-grey colour