METHOD FOR PRODUCE A PRINTED PLASTISOL OR LACQUER LAYER

Description

[0001] The invention relates to a method for producing a printed plastisol or lacquer layer.

[0002] Printed plastisol or lacquer coatings are used, for example, in the production of wall coverings with digitally printed designs or in the production of floor coverings. The digital printing of polymer substrates is known from WO 2015 / 140682 A1. Ink adhesion and color homogeneity are key quality criteria for the print. Particularly with polymer substrates, homogeneous surface properties are desirable, regardless of the ink used, to prevent defects caused by localized wetting problems ("island formation"), insufficient abrasion resistance, and the resulting color inconsistencies.

[0003] A method for inkjet printing on a non-absorbent substrate is known from EP 2 249 971 B1. Another method for producing a surface coating, in which printing takes place on a still liquid material layer prior to a hardening step, is known from the subsequently published EP 3 335 897 A1.

[0004] US patent 2016 / 297223 A1 discloses a method for producing a printed varnish layer, comprising the steps of: providing a web-shaped carrier; applying a flowable, liquid varnish layer to the carrier; non-contact printing of the flowable varnish layer; and curing the printed varnish layer, wherein the non-contact printing of the flowable varnish layer includes inkjet printing.

[0005] A significant disadvantage of prior art processes, such as printing onto a PVC plastisol layer previously applied to a substrate, lies in the required thermal treatment of the PVC plastisol for gelation or hardening. This necessitates, for example, exposing the substrate to a gelation temperature of typically 140°C to 160°C. However, the polymeric substrates used in many products, such as floor coverings, are no longer mechanically stable or processable within this temperature range. Examples of these unsuitable substrates include 50–250 µm thick calendered S-PVC films for the production of luxury vinyl tiles (LVT) or PVC / PET films used in decorative applications.

[0006] The object of the invention is therefore to propose a method for producing a printed plastisol or varnish layer which allows the printed plastisol or varnish layer to be applied to temperature-sensitive substrates that are not resistant or processable at the temperatures required for hardening the plastisol or varnish layer.

[0007] This problem is solved by a method having the features of claim 1. The dependent claims each relate to advantageous embodiments of the invention.

[0008] Accordingly, the procedure is designed to include the following steps: Providing a web-shaped carrier with a release coating and / or a surface with release properties; applying a flowable, preferably liquid or solar-like plastisol or lacquer layer to the release coating and / or the surface with release properties; contactless printing of the flowable plastisol or lacquer layer; and curing of the printed plastisol or lacquer layer. where the contactless printing of the flowable plastisol or varnish layer includes digital printing.

[0009] The production of the printed plastisol or varnish layer can thus be carried out independently of the provision of the substrate onto which the printed plastisol or varnish layer can be applied in a subsequent process step, particularly for decorative purposes. This means that the thermal treatment of the plastisol or varnish layer, in particular a corresponding gelling step, a curing step, or a drying step, takes place without thermal stress on the substrate. After curing, the printed plastisol or varnish layer can be fed inline to a laminating device, where it is laminated onto a substrate that may be temperature-sensitive. Alternatively, the printed plastisol or varnish layer can be stored on the web-shaped substrate until further processing, for example, by winding it onto a spool along with the web-shaped substrate.

[0010] Providing a web-shaped carrier with a release coating and / or a surface with separating properties can include a release liner or a surrounding transfer belt. The release liner or the surrounding transfer belt can have a silicone-containing coating as the release coating. The release coating and / or the surface with separating properties are not limited to any particular embodiment. In particular, the release coating does not necessarily have to be a separate layer from the web-shaped carrier. The release coating can be obtained by conditioning the web-shaped carrier with adhesion-reducing materials, for example, by siliconizing a carrier fabric tape. The essential requirement is solely a non-adhesive or separating property between the surface of the carrier and the plastisol or lacquer layer.For example, stainless steel strips are known that allow the removal of a hardened plastisol or paint layer without the application of a separating layer.

[0011] During the hardening process, the printed plastisol or varnish layer can be heated to more than 130°C and preferably to more than 150°C.

[0012] Non-contact printing of the flowable plastisol or varnish layer includes digital printing, for example inkjet printing or laser printing.

[0013] When applying a flowable plastisol or varnish layer, a UV varnish layer can be applied, which is cured by UV irradiation after contactless printing. Alternatively or additionally, the application of a flowable plastisol or varnish layer can include the application of a solar-resistant PVC plastisol layer, which is heated to a temperature preferably above 130°C during curing, which may involve gelation of the solar-resistant plastisol layer. According to a further alternative, an aqueous varnish layer can be applied when applying a flowable plastisol or varnish layer, which is cured by drying after contactless printing.

[0014] After the printed plastisol or varnish layer has cured, an adhesion promoter can be applied to the printed and cured layer and then dried. The adhesion promoter can be applied to the printed side of the plastisol or varnish layer. It can be used to improve the adhesion of the plastisol or varnish layer to a clear film or a wear-resistant film.

[0015] After the printed plastisol or varnish layer has hardened, the web-shaped carrier with the applied plastisol or varnish layer can be provided on a winding spool for later processing.

[0016] After curing, the printed plastisol or lacquer layer on the web-shaped carrier can be fed into a laminating machine and laminated onto a substrate. Because the substrate is not exposed to the temperatures used to cure the plastisol or lacquer layer, the dimensions of the potentially temperature-sensitive substrate can be controlled. This is an essential prerequisite for the embossing in the register that often follows lamination, for example, in the production of floor coverings such as LVT. Accordingly, the process can include embossing the laminate after the cured and printed plastisol or lacquer layer has been laminated onto a substrate.

[0017] Before or during lamination, the plastisol or lacquer layer can be detached from and removed from the sheet-like carrier. In an alternative embodiment, the sheet-like carrier can remain attached to the plastisol or lacquer layer and be laminated onto the substrate as an intermediate layer between the plastisol or lacquer layer and the substrate.

[0018] Laminating the plastisol or lacquer layer onto the substrate can involve laminating the plastisol or lacquer layer onto a clear film and / or onto the substrate of a floor covering. The clear film can be laminated onto the plastisol or lacquer layer, with the plastisol or lacquer layer positioned between the substrate and the clear film in the resulting laminate.

[0019] Laminating the printed plastisol or varnish layer onto the substrate can be carried out at a laminating device temperature of less than 130°C, and preferably at a temperature of less than 110°C, using, for example, a thermally plasticized substrate. During printing, an ink can be introduced into the flowable plastisol or varnish layer. Alternatively, an adhesive property can be used without thermal plasticization, such as a hot melt. The printing process includes digital printing. The digital printing can be, for example, laser printing or inkjet printing.

[0020] If the flowable plastisol or varnish layer is a plastisol layer, the curing of the printed plastisol layer may involve gelling or glazing the printed plastisol layer, stabilizing the ink in the gelled or glazing plastisol layer.

[0021] When providing a web-shaped carrier with a release coating and / or a surface with a separating property, for example a siliconized paper, textile or fabric can be provided onto which a PVC plastisol is applied during the application process, which gels or gels after printing during hardening.

[0022] Further details of the invention are explained with reference to the figures below.

[0023] This shows: Figure 1 schematically shows a first embodiment of a possible plant layout for carrying out the method according to the invention; Figure 2 schematically shows a second embodiment of a possible plant layout for carrying out the method according to the invention; Figure 3 schematically shows a third embodiment of a possible plant layout for carrying out the method according to the invention; and Figure 4 schematically shows a fourth embodiment of a possible plant layout for carrying out the method according to the invention.

[0024] At the in Figure 1In the illustrated embodiment, a web-shaped carrier 1 with a release coating 2 and / or a surface with release properties is provided from a spool 13 in a process step 100. The web-shaped carrier 1 with the release coating 2 and / or the surface with release properties is fed to a plastisol applicator 14, by means of which a flowable plastisol layer 3 is applied to the release coating 2 and / or the surface with release properties in a step 200. The plastisol layer 3 is particularly still flowable and has a sol-like consistency when it has not yet been gelled or cured.

[0025] After the free-flowing plastisol or lacquer layer 3 has been applied to the release coating 2 and / or the surface with release properties of the web-shaped carrier 1 in step 200, it is printed contactlessly in its free-flowing state in step 300. In the present embodiment, ink 9 is introduced into the free-flowing plastisol layer 3 using digital printing, for example, laser printing or inkjet printing. In a subsequent step 400, the printed plastisol layer 3 is cured. The curing process in step 400 can involve gelation or gelling.

[0026] In this way, a printed and hardened plastisol or varnish layer 3 can be provided on a web-shaped carrier 1 and, for example, immediately transported inline to a laminating device 6 for further processing or provided offline, for example by storing the printed plastisol or varnish layer on a winding spool 5 for later processing.

[0027] In the case of inline processing of the produced printed and cured plastisol layer 3, it can be fed on its web-shaped carrier 1 to a laminating device 6, where in step 600 the web-shaped carrier 1 is detached from and removed from the plastisol layer 3. The web-shaped carrier 1 can be wound onto a winding spool 12. The web-shaped carrier 1 wound onto the winding spool 12 can later be reused by being reintroduced into the process in step 100.

[0028] A clear film 8 is fed into the laminating device 6. The printed side of the plastisol layer 3 is applied to the clear film 8, and the plastisol layer 3 is then laminated onto a substrate 7, so that the plastisol layer 3 is positioned between the clear film 8 and the substrate 7 in the resulting laminate. Optionally, the clear film 8 is heated by infrared radiation 10 immediately before being applied to the plastisol layer 3 to improve its adhesion. Similarly, in lamination step 500, the substrate 7 fed into the laminating device 6 is also optionally heated by the preheating device 11, e.g., an IR emitter, immediately before it comes into contact with the plastisol layer 3, to further improve the adhesion of the plastisol layer 3 to the substrate 7.The laminating device 6 has a heated roller which basically provides sufficient heat input to the clear film 8 and the substrate 7 to bond the produced laminate together.

[0029] As also shown, in an alternative embodiment of the described method it can be provided that only the plastisol layer 3 and the clear film 8 are joined to form a laminate by the laminating device 6 in the lamination step 500 and in particular are not (yet) combined with the substrate 7 to form a three-layer laminate, but instead the two-layer laminate consisting of clear film 8 and plastisol layer 3 is removed in step 900.

[0030] The in Figure 2 The embodiment shown differs from the one in Figure 1The embodiment shown is characterized in that, instead of a web-shaped carrier 1 which is provided via an unwinding spool 13 and taken up again on a winding spool 12, the web-shaped carrier 1 is provided in the form of a circumferentially closed transfer belt, which, however, according to the principles of the invention, has a separating coating 2 and / or a surface with separating properties on one side facing the plastisol layer 3 in order to achieve the easy removal of the printed plastisol layer produced on the web-shaped carrier 1 after hardening 400.

[0031] The in Figure 3 The embodiment shown differs from the one in Figure 1In the illustrated embodiment, a UV lacquer application unit 15 is used instead of a plastisol application unit 14 to apply a UV lacquer layer 3 to the web-shaped carrier 1 in step 200. After printing the UV lacquer layer in step 300, the still liquid UV lacquer layer is cured by UV irradiation in step 400.

[0032] In one variant of the in Figure 3 In the illustrated embodiment, a step 700 is provided downstream of the hardening 400 and upstream of the laminating 500, in which an adhesion primer 4 is applied to the printed and hardened lacquer layer 3 and dried in a subsequent step 800. The adhesion primer 4 is applied to the printed side of the lacquer layer 3 and is intended to improve the adhesion of the printed lacquer layer 3 to the clear film 8.

[0033] The in Figure 4 The embodiment shown differs from the one in Figure 1The embodiment shown is characterized in that, instead of a plastisol applicator, a lacquer applicator 16 is provided, via which a lacquer is applied to the release coating 2 and / or the surface with release properties of the web-shaped carrier 1. According to the principles of the present invention, this lacquer coating 3, while still flowable, in particular liquid, is printed in step 300 by the introduction of ink 9 and subsequently cured by drying in step 400. The lacquer can be aqueous or

[0034] Further advantageous embodiments of the invention result from the subject matter defined in the following claims. Reference symbol list

[0035] 1. Reference symbol list 1 Carrier 2 Release coating and / or surface with release properties 3 Plastisol or lacquer layer 4 Adhesion primer 5 Take-up reel 6 Laminating unit 7 Substrate 8 Clear film 9 Ink 10 Clear film preheating unit 11 Substrate preheating unit 12 Take-up reel 13 Unwind reel 14 Plastisol applicator 15 UV lacquer applicator 16 Lacquer applicator 100 Preparing 200 Applying 300 Printing 400 Curing 500 Laminating 600 Peel and remove 700 Applying 800 Drying 900 Ejecting

Claims

1. A method for producing a printed plastisol layer or paint layer, comprising the steps of: - providing (100) a rail-shaped carrier (1) having a release coating (2) and / or a surface having a releasing property; - applying (200) a flowable, preferably liquid or sol-like plastisol layer or paint layer (3) onto the release coating (2) and / or the surface having a releasing property; - contactless printing (300) of the flowable plastisol layer or paint layer (3); and - curing (400) the printed plastisol layer or paint layer (3), wherein the contactless printing (300) of the flowable plastisol layer or paint layer (3) comprises a digital printing.

2. The method according to claim 1, wherein (i) the release coating (2) and the surface having a releasing property has a non-adhesive or releasing property between the surface of the rail-shaped carrier (1) and the plastisol layer or paint layer (3); and / or (ii) the providing (100) of a rail-shaped carrier (1) having a release coating (2) and / or a surface having a releasing property comprises providing a release liner or a circulating transfer belt.

3. The method according to claim 1 or 2, wherein during the curing (400), the printed plastisol layer or paint layer (3) is heated to more than 130 °C, preferably to more than 150 °C.

4. The method according to any of the preceding claims, wherein the contactless printing (300) of the flowable plastisol layer or paint layer (3) comprises an inkjet printing.

5. The method according to any of the preceding claims 1 or 2, wherein during the applying (200) of a flowable plastisol layer or paint layer (3), a UV paint layer is applied, which after the contactless printing (300) is cured by means of UV irradiation.

6. The method according to any of the preceding claims 1 or 2, wherein during the applying (200) of a flowable plastisol layer or paint layer (3), a paint layer is applied, which after the contactless printing (300) is cured (400) by means of drying or chemical crosslinking.

7. The method according to any of the preceding claims, wherein after the curing (400) of the printed plastisol layer or paint layer (3), an adhesion primer (4) is applied (700) onto the printed and cured plastisol layer or paint layer (3) and is subsequently dried (800).

8. The method according to any of the preceding claims, wherein after the curing (400) of the printed plastisol layer or paint layer (3), the carrier (1) with the plastisol layer or paint layer (3) applied thereon is provided on a take-up reel (5) for later further processing.

9. The method according to any of the preceding claims, wherein after the curing (400), the printed plastisol layer or paint layer (3) on the rail-shaped carrier (1) is fed to a laminating device (6) and is laminated (500) onto a substrate (7) with the laminating device (6), wherein optionally before the laminating (500) or during the laminating (500), the plastisol layer or paint layer (3) is detached and removed (600) from the rail-shaped carrier (1).

10. The method according to claim 9, wherein the laminating (500) of the plastisol layer or paint layer (3) onto a substrate (7) comprises the laminating (500) of the plastisol layer or paint layer (3) onto a clear film (8) and / or onto a carrier layer of a floor covering.

11. The method according to claim 9 or 10, wherein the laminating (500) of the printed plastisol layer or paint layer (3) onto the substrate (7) is carried out at a temperature of less than 130 °C and preferably at a temperature of less than 110 °C.

12. The method according to any of the preceding claims, wherein during the printing (300), an ink (9) is introduced into the flowable plastisol layer or paint layer (3).

13. The method according to claim 12, wherein the flowable plastisol layer or paint layer is a plastisol layer and the curing (400) of the printed plastisol layer comprises the gelling of the printed plastisol layer, wherein the ink (9) is stabilized in the plastisol layer.

14. The method according to any of the preceding claims, wherein during the providing (100) of a rail-shaped carrier (1) having a release coating and / or a surface having a releasing property, a siliconized paper, textile, or fabric is provided, onto which during the applying (200) a PVC plastisol is applied, which after the printing (300) is gelled during the curing (400).