WO2003070445A1

WO2003070445A1 - Colour decoration system

Info

Publication number: WO2003070445A1
Application number: PCT/EP2003/001604
Authority: WO
Inventors: Sven Jacobsen; Christian Kuckertz
Original assignee: Wipak Walsrode Gmbh & Co. Kg
Priority date: 2002-02-22
Filing date: 2003-02-18
Publication date: 2003-08-28
Also published as: DE10207639A1; AU2003210295A1

Abstract

The invention relates to a colour decoration system comprising a series of layers including at least a) one transparent surface layer based on a polymer blend at least consisting of a thermoplastic polyalkylmethacrylate, optionally at least one thermoplastic polyalkylacrylate, and at least one elastomer polymer, said surface layer being provided with b) a colour decoration layer, c) a connecting layer consisting of a plastic material which connects to the substrate to be decorated under the effect of heat, and d) optionally a preferably biaxially oriented protective layer which is arranged between the colour decoration layer b) and the connecting layer c) and consists of a plastic which has a higher softening point than the plastic material of layer c).

Description

Color decorating system

The present invention relates to color decoration systems comprising a layer sequence of at least one transparent surface layer based on a polymer blend made of thermoplastic polyalkyl methacrylate and an elastomeric polymer component distributed therein, a color decoration layer applied thereon and a connecting layer made of plastic material which optionally adjoins the color decoration layer and which is exposed to heat with the addition of decorating substrate connects, and a protective layer of plastic, which may be arranged between the color decoration layer and the connecting layer, and which has a higher softening point than the plastic material of the connecting layer.

From European patent application EP-A-0 694 377 it is already known to decorate substrates made of polyolefins, preferably polypropylene, with a color decoration system whose surface layer consists of polymethyl methacrylate. According to the statements in this published specification, these color decoration systems, especially if they are equipped with UV absorbers, should have a lower tendency to delaminate under temperature fluctuations or UV radiation. If, however, substrates with a more complex, three-dimensional design are to be equipped with such color decoration systems, it turns out that such substrates cannot be decorated flawlessly. It is observed that, for. B. in a shaping of the substrate by back injection, the initial bond with the color decor system introduced into the mold is not sufficiently durable and the surface layer has a tendency to chip off in places with a more complicated design, which can damage the color decor.

In addition, when injecting such a color decor system with plastic materials, such as. B. polypropylene, for shaping the substrate to be decorated to thermal and / or mechanical damage to the color decoration layer, since the plastic layer lying over the color decoration layer should have a lower melting point than the molded plastic material, such as polypropylene, and a complete Melting of this layer can take place. This may not only damage the temperature-sensitive dyes, but also damage the overall mechanical integrity of the color layer.

The object of the present invention was therefore to provide a color decoration system which does not have these disadvantages and is particularly suitable for decorating three-dimensional substrates which are preferably designed in contact with the color decoration system.

This object is achieved by making the color decor system according to the invention available.

The color decor system according to the invention has at least one layer sequence

a.) a transparent surface layer based on a polymer blend of at least one thermoplastic polyalkyl methacrylate, optionally at least one thermoplastic polyalkyl acrylate and at least one elastomeric polymer, which is provided with

b.) a color decor layer,

c.) a connecting layer made of a plastic material that bonds to the substrate to be decorated and

d.) if appropriate, a preferably biaxially oriented protective layer made of plastic, which has a higher softening point than the plastic material of layer c), is arranged between the color decorative layer b.) and the connecting layer c).

The transparent surface layer a) is preferably made of a polymer blend of up to 40% by weight, preferably from 15 to 30% by weight, based on the total amount of polymers, of an elastomeric polymer, preferably one elastomeric polymers that do not impair transparency, particularly preferably a crosslinked polybutyl acrylate.

The thermoplastic polyalkyl methacrylate present in the polymer blend is preferably a polymethyl methacrylate and, if appropriate, up to 20% by weight, based on the thermoplastic polymer component, a poly-C2-C ₄ -alkyl methacrylate or preferably a poly-C 1 -C ₄ -alkyl acrylate, particularly preferably polybutyl acrylate.

The polymer blend therefore particularly preferably consists of polymethyl methacrylate, optionally up to 20% by weight, based on the thermoplastic polymer component, polybutyl acrylate and a crosslinked polybutyl acrylate.

In addition, layer a) preferably has UV absorber compounds for absorbing UV radiation, which are preferably chemically bound. These are preferably known organic UV absorber compounds, such as. B. sterically hindered phenols, benzophenones, benzotriaxols, particularly preferably sterically hindered amine compounds such as so-called HALS compounds, which are each used in amounts such that at least 95%, preferably 98 to 99% of the UV radiation is absorbed.

The surface layer is transparent, so that the colored decoration layer is visible through this layer a.).

The color decorative layer b) is preferably printed on the layer a), it being possible to use the known printing inks, preferably based on polyvinyl chloride or polyvinyl butyrate as a binder. Color decor is not only the application of a colored design for aesthetic reasons such. B. understood a pattern or a single-colored, coherent layer of color, but also the application of labels, preferably advertising and / or information labels.

This also includes the application of codes to secure, record and / or protect against unauthorized copying. You can do this in addition to Printing inks also correspondingly printable solutions as marking substances, such as. B. electrically conductive polymers or fluorescent pigments can be used.

The printing inks or the marking substances used are preferably in the form of solvent-containing systems which have, as solvents, customary solvents for printing inks, such as acetone or toluene. The color decors, such as B. print images, advertising lettering and / or coding, are preferably applied by gravure or flexographic printing to layer a).

The layer c), which consists of a plastic material that connects to the substrate to be decorated under the action of heat, has the function of a connecting layer. The softening point of the plastic material should preferably be at least 95 ° C, more preferably than the softening point of the substrate to be decorated in the range of 100 ° C, up to a temperature lying lower at most equal to, or preferably by at least 5 ^C C. If, therefore, the substrate to be decorated consists of a plastic material, layer c) should preferably consist of a polymer, the predominant part of which consists of the monomer units from which the plastic material of the substrate to be decorated is constructed. For example, an ethylene-propylene copolymer with a predominant proportion of propylene is mentioned as the plastic material, provided the substrate consists of polypropylene.

The color decor system according to the invention preferably has a further layer d) which is arranged as a protective layer between the color decor layer b) and the connecting layer c). This protective layer is preferably based on a plastic that has a higher softening point than the plastic material of layer c), the so-called connecting layer. This protective layer is preferably oriented at least monoaxially, particularly preferably biaxially.

Layer d) ensures that, in particular when decorating such substrates, only by back injection or back pressing of the Decorative systems are made with a polymeric substrate material, the color decorative layer is not damaged when softening the connecting layer. Layer d) is preferably made of a polyester, an olefinic homo- or copolymer, preferably of polyethylene terephthalate, polypropylene, polyethylene or an ethylene / propylene copolymer, it being necessary to ensure that the softening point of the protective layer d) is at least 10 K higher than the softening point of the plastic of the connecting layer c). If the substrate to be decorated consists of plastic, the plastic of the protective layer d) can preferably be constructed from the same monomer units as the substrate polymer.

The color decor system according to the invention can furthermore each have an adhesion promoter layer between the layers b) and c) or b) and d) and / or d) and c). For these layers, depending on the plastic materials to be bonded, known adhesion promoter systems, such as, for. B. an optionally solvent-containing two-component polyurethane adhesive or a polyacrylate adhesive or a maleic anhydride grafted polypropylene can be used.

The thickness of layer a) is preferably in the range from 10 to 150 μm, particularly preferably from 30 to 130 μm. The thickness of the layer c) is preferably in the range from 20 to 500 μm, particularly preferably from 30 to 250 μm, very particularly preferably in the range from 30 to 100 μm. If layer d) is present, its thickness is preferably in the range from 8 to 300 μm, particularly preferably from 12 to 30 μm.

Not only does the transparent surface layer a) contain the abovementioned compounds for absorption of UV radiation, but also layer c) or d) and, if the layer b) and c) or layer b) and d are combined ) an adhesion promoter layer is used, in each case also this adhesion promoter layer (s), it being possible for the corresponding compounds, preferably also chemically, to be bound.

To produce the color decor system according to the invention, the polymer blend is made from at least one thermoplastic polyalkyl methacrylate, optionally a thermoplastic polyalkyl acrylate and a preferably homogeneously distributed elastomeric polymer, preferably a crosslinked polybutyl acrylate, preferably by extrusion or coextrusion, the transparent surface layer a) is produced. This layer is with flexographic or gravure printing or with the help of another known printing process such. B. screen printing, digital printing or inkjet printing the color decor in the appropriate pattern, for. B. as a veneer replacement, as a compact layer of paint, as information and / or advertising and / or applied for coding.

If the color decoration system according to the invention is intended to comprise the protective layer d), this is produced separately using customary processes, such as flat film extrusion or the film blowing process, preferably using monoaxial, particularly preferably biaxial stretching, and with the aid of a suitable adhesion promoter system onto the printed side and thus onto the color decoration layer b .) laminated. If layer d) is not to be present in the color decoration system according to the invention, layer c) is laminated onto the color decoration layer b), preferably again using a suitable adhesion promoter system.

Both in the presence of a layer d) and in the direct connection of the layer c) with the layer sequence a) and b), the connection layer c) is preferably produced separately by flat film extrusion or by extrusion according to the film blowing process and with the layer sequence a) and b) or a), b) and d) with the aid of a suitable adhesion promoter system, which preferably contains solvents. In addition, layer c) can also be applied in the coating process.

The color decor system according to the invention is suitable for decorating substrates of any kind, such as substrates made of plastics, preferably polyamides, polyolefins, polyesters, such as. B. polyamide-6, polyamide-6,6, polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, wood-based substrates, such as. B. chipboard, fibreboard, paper, provided that only the respective substrate with the layer c) connects permanently under the influence of heat. The color decor system according to the invention is preferably suitable for Decorating substrates, particularly preferably three-dimensional substrates with a complicated design.

Another object of the present invention is therefore a substrate, decorated with a color decoration system according to the invention, preferably a molded plastic body, which was designed and simultaneously decorated by back injection or back pressing of the color decoration system according to the invention.

For this purpose, the color decor system according to the invention, which preferably has a protective layer d), is placed in a mold such that the surface layer a) is in direct contact with the wall of the mold and the connecting layer c) connects to the heated substrate material introduced into the mold and the decorated shaped body is removed from the mold after cooling.

The softened plastic of the substrate material is preferably introduced into the mold by injection molding or is connected to the color decoration system according to the present invention by back pressing in the mold. For this purpose, polypropylene is particularly suitable as the substrate material and an ethylene / propylene copolymer as the plastic material of the layer c) or a polyethylene with a density of 0.92 to 0.98 g / cm ³ as the substrate material and an ethylene homo- as the plastic material of the connecting layer c) or copolymer with a softening point lower than the softening point of the polyethylene from which the substrate is made.

With the color decor system according to the invention, however, it is also possible to decorate flat substrates, such as plates or paper under the influence of heat, which leads to the softening of the connecting layer c), provided that the paper or the corresponding plate, preferably a particle board, has connections that are can connect the plastic material of layer c) either physically or chemically.

The present invention therefore furthermore relates to processes for decorating a preferably three-dimensional substrate by combining an inventive color decor system with the connecting layer c) with the Bring the substrate into contact so that the color decoration system is permanently connected to the substrate to be decorated via the layer c). The substrate is preferably a continuous plate which decorates inline or a shaped body which is first formed in a mold and at the same time is decorated with the color decor system according to the invention.

The softening point of the polymers used corresponds to the Vicat softening temperature, which is defined and determined in accordance with ISO EN 306.

Examples

example 1

A 125 μm thick film made of a polymer blend made of polymethyl methacrylate and 15% by weight, based on the polymer components, of a crosslinked polybutyl acrylate is gravure printed with PVC-based printing inks. The printed side is laminated with a 15 μm thick, biaxially oriented polypropylene (BOPP) film using a solvent-based 2-component polyurethane adhesive system. This pre-composite is bonded to a separately produced cast film made of propylene / ethylene copolymers (50 μm thick) using the solvent-based 2-component polyurethane adhesive system.

1a.)

Alternatively, the above-described composite is connected to the above-described propylene / ethylene copolymer film using an acrylate-based adhesive system.

1 b.)

The preliminary composite described above is coated on the BOPP film side with a 50 μm thick ethylene / propylene copolymer layer. The resulting groups are e.g. B. suitable for decoration by back injection with a homopolymeric propylene. For this purpose, a pre-punched color decoration system according to the invention is placed in the opened injection mold of a conventional injection molding machine, pneumatically fixed and, after the mold has been closed, back-injected with a propylene homopolymer at 200 ° C. The propylene / ethylene copolymer layer (melting point 129 ° C.) melts at least partially and thus enables an intimate connection of the color decoration layer with the substrate. After the cooling process has ended, the decorated substrate is removed from the injection mold.

Example 2

A 60 μm thick film made of a polymer blend composed of 60% by weight of polymethyl methacrylate and 10% by weight of polybutyl acrylate and 30% by weight of crosslinked polybutyl acrylate, in each case based on the total amount of the polymer blend, was rotogravured with PVB-based printing inks as color decor b) printed. A 30 μm thick biaxially oriented polyethylene film (PE soaking point 124 ° C) is laminated onto the color decor using solvent-free 2-component PU laminating adhesive. This composite is coated with a layer of ethylene vinyl acetate copolymer with a softening point of 98 ° C as a connecting layer. The color decor system according to the invention is placed in an injection mold in such a way that layer a) lies directly against the mold wall and layer c) combines with the polyethylene injected into the mold. After cooling, the PE substrate decorated in this way can be removed from the mold.

Example 3

A 125 μm thick film made of a polymer blend of polymethyl methacrylate and and 15% by weight, based on the polymer components, of a cross-linked polybutyl acrylate is printed with a carbon design in flexographic printing, PVC-based printing inks being used. This film is laminated with a 150 μm thick PET film (polyethylene terephthalate film) using a solvent-based, aliphatic 2-component PU adhesive. This preliminary network is provided with a copolyamide layer, the connecting layer c) having been applied in a thickness of 25 μm on the PET side of the composite.

This composite is laminated to a medium-thick fibreboard (MDF) under the influence of heat at 95 ° C (softening point of the copolyamide approx. 75 ° C). You get a very scratch-resistant, high-gloss, weatherproof wood paneling.

Claims

claims

1. color decor system comprising a layer sequence of at least

b.) a color decor layer,

d.) if appropriate, a preferably biaxially oriented protective layer made of a plastic which is arranged between the color decorative layer b.) and the connecting layer c) and which has a higher softening point than the plastic material of the layer c).

2. color decor system according to claim 1, characterized in that between the layers b) and c), b) and d) and / or d) and c) there is in each case an adhesion promoter layer.

3. Color decor system according to claim 1 or 2, characterized in that the polymer blend of layer a) from up to 40% by weight, preferably from 15 to 30% by weight, based on the total amount of polymer, of an elastomeric polymer, preferably a crosslinked one Polybutyl acrylate exists.

4. color decor system according to one of claims 1 to 3, characterized in that the polymer blend as a thermoplastic polyalkyl methacrylate, a polymethyl methacrylate and optionally up to 20 wt.%, Based on the thermoplastic component, poly-C ₂ -C ₄ -alkyl methacrylates or preferably poly -C-C ₄ alkyl acrylates, particularly preferably polybutyl acrylates, contains.

5. color decor system according to one of claims 1 to 4, characterized in that the layer a) contains chemically bound UV absorber compounds in such amounts that at least 95% of the UV radiation is absorbed.

6. color decor system according to one of claims 1 to 5, characterized in that the layer d) consists of a polyester, an olefinic homo- or copolymer, preferably of polyethylene terephthalate, polypropylene, polyethylene or an ethylene / propylene copolymer.

7. color decor system according to one of claims 1 to 6, characterized in that the plastic material of layer c) has a softening point of at least 95 ° C, preferably in the range of 100 ° C to a temperature which is equal to or lower than the softening point of the decorating substrate.

8. color decor system according to one of claims 1 to 7, characterized in that the layer c) consists of a plastic material, the predominant proportion of monomer units of which corresponds to the monomer from which the substrate to be decorated is constructed.

9. A method for decorating a substrate, characterized in that a color decoration system according to one of claims 1 to 8 with the connecting layer c) is brought into contact with the substrate in such a way that, under the action of heat, the color decoration system over the layer c) with the decoration Substrate connects.

10. The method according to claim 9, characterized in that one places a color decoration system according to one of claims 1 to 8 in a mold so that the surface layer a) has direct contact with the wall of the mold and the connecting layer c) with the in the Formed, heated substrate material connects and removes the decorated substrate from the mold after cooling.

11. The method according to claim 10, characterized in that a softened plastic is introduced as a substrate material in the mold.

12. The method according to claim 11, characterized in that the softened plastic is connected by injection molding, preferably back molding, or back pressing with the color decor system in the mold.

13. The method according to claims 9 to 12, characterized in that the connecting layer c) consists of an ethylene / propylene copolymer and the substrate consists of polypropylene.

14. The method according to claims 9 to 12, characterized in that the connecting layer c) consists of an ethylene homo- or co-polymer and the substrate consists of a polyethylene with a density of 0.92 to 0.98 g / cm ³ ,

15. substrate decorated with a color decoration system according to one of claims 1 to 8.

16. The substrate according to claim 15, characterized in that the substrate consists of polypropylene and the connecting layer c) consists of an ethylene / propylene copolymer.

17. The substrate according to claim 15, characterized in that the substrate consists of a polyethylene with a density of 0.92 to 0.98 g / cm ³ and the connecting layer c) consists of an ethylene homo- or co-polymer.