阅读说明：本技术 提供图像的印版和生产印版的方法 (Printing plate for providing image and method for producing printing plate ) 是由 阿明·塞内 于 2018-10-16 设计创作，主要内容包括：本发明涉及一种提供图像的印刷模板,其包括具有弹性体涂层的基底,其中该弹性体涂层带有雕刻图案,其特征在于,该弹性体涂层包括硬橡胶并且具有高于40肖氏D的硬度。此外,本发明包括一种用于生产提供图像的印刷模板的方法,以及还有用于凹版印刷的方法。(The present invention relates to a printing stencil for providing an image, comprising a substrate having an elastomeric coating, wherein the elastomeric coating carries an engraved pattern, characterized in that the elastomeric coating comprises a hard rubber and has a hardness higher than 40 shore D. Furthermore, the invention comprises a method for producing a printing stencil for providing an image, and also a method for intaglio printing.)

1. A printing template for providing an image, comprising a substrate having an elastomeric coating, wherein the elastomeric coating carries an engraved pattern, characterized in that the elastomeric coating comprises a hard rubber and has a hardness higher than 40 shore D.

2. The image-providing printing stencil of claim 1, wherein the hard rubber is based on a hard rubber of: butadiene-acrylonitrile rubber (NBR), carboxylated nitrile rubber (XNBR), ethylene-vinyl acetate copolymer (EVAC), ethylene-vinyl acetate rubber (EVM), hydrogenated acrylonitrile-butadiene rubber (HNBR), perfluoroelastomer (FFKM), ethylene-acrylate rubber (AEM), polyacrylate rubber (ACM), chlorinated polyethylene rubber (CM), chlorosulfonyl polyethylene rubber (CSM), ethylene-propylene-diene rubber (EPDM), ethylene-propylene rubber (EPM), Fluororubber (FKM), epichlorohydrin rubber (CO), epichlorohydrin copolymer rubber (ECO), propylene oxide copolymer rubber (GPO), Butadiene Rubber (BR), Chloroprene Rubber (CR), isobutylene-isoprene rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), Isoprene Rubber (IR), Nitrile Butadiene Rubber (NBR), Natural Rubber (NR), Styrene Butadiene Rubber (SBR), fluorosilicone rubber (FVMQ), methylphenyl silicone rubber (PMQ), methylphenyl vinyl silicone rubber (PVMQ), methyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), polyester urethane (AU), polyether urethane (EU), or a combination thereof.

3. The image-providing printing stencil of claim 1 or 2, wherein the hard rubber is a hard rubber based on butadiene-acrylonitrile rubber (NBR), ethylene-propylene-diene rubber (EPDM), or a combination thereof.

4. The image-providing printing stencil of any of claims 1 to 3 being in the form of a gravure printing cylinder or plate.

5. The image-providing printing stencil of any of claims 1 to 4, wherein the substrate is a hollow cylinder, an axial cylinder, or a sleeve that is a cylindrical reinforcing structure.

6. The image providing printing stencil of any of claims 1 to 5, wherein the elastomeric coating has a hardness of at least 70 Shore D.

7. The image providing printing stencil of any of claims 1 to 6, wherein the elastomeric coating has a thickness of at least 30 μ ι η.

8. The image providing printing stencil of any of claims 1 to 6, wherein the surface of the elastomeric coating has a roughness average depth Rz of less than 1 μ ι η.

9. A method for producing a printing stencil for providing an image, comprising

a. A substrate is provided, and the substrate,

b. providing an elastomeric coating on the substrate, and

c. an engraved pattern is provided on the elastomeric coating by engraving,

characterized in that the elastomeric coating comprises a hard rubber and has a hardness higher than 40 Shore D.

10. The method of claim 9, wherein the step b of providing an elastomeric coating on the substrate comprises the steps of:

b.1 covering the substrate with an elastomer or elastomer mixture,

b.2 vulcanizing the elastomer or the elastomer mixture and forming the hard rubber,

b.3 removing excess hard rubber by a turning procedure, an

b.4 removing material from the surface of the elastomer coating by grinding.

11. The method of claim 9 or 10, wherein the engraving is achieved by an electromechanical engraving program or by a laser engraving program.

12. A method for gravure printing comprising

a. Providing an image providing printing stencil according to any of claims 1 to 8,

b. applying ink on the surface of the printing stencil, and

c. transferring the ink from the surface of the printing stencil to a printable substrate.

Technical Field

The present invention relates to a printing stencil for providing an image, comprising a substrate having an elastomeric coating, wherein the elastomeric coating carries an engraved pattern, characterized in that the elastomeric coating comprises a hard rubber and has a hardness higher than 40 shore D. Furthermore, the invention comprises a method for producing a printing stencil for providing an image, and also a method for intaglio printing.

Background

The gravure printing method is a printing technique in which the elements to be copied are present as recesses (cells) in the printing template. The printing program includes: the ink is first applied to the entire printing stencil, excess ink is removed using a doctor blade or wiper, the printing ink is then allowed to reside only in the depressions, and the printing ink is then transferred to the paper.

The printing template may be a plate or a gravure cylinder. However, the industry has particular interest in web gravure printing, where the printing stencil is a gravure printing cylinder. By way of example, the method is used to print a journal or catalog.

The image-providing (printing) surface of the printing stencil is produced in a conventional manner by: a soft copper layer having a hardness of, for example, 2 on mohs scale is first subjected to electromechanical engraving or laser engraving and the printing unit is engraved. The softness of the copper layer is necessary to enable the engraving tools used in the prior art to engrave without immediately suffering from unacceptable wear. If these tools suffer excessive wear, the economic behaviour of the method will no longer be feasible. A hard chrome layer having a hardness of, for example, 8 mohs is then applied using an electroplating procedure to protect the engraved layer from wear by the doctor blade during the printing process.

However, this conventional approach has attendant disadvantages: this method requires the application of two layers on the printing stencil and is therefore relatively complex and energy consuming. For the application of the chromium layer, the method also comprises an electroplating step, which is extremely disadvantageous for reasons relating to health and environment. In particular, the application of hard chrome layers generally uses chromium trioxide (VI), which is highly toxic during the application procedure before the deposition is completed. Furthermore, proper handling of chromium compounds is problematic not only for environmental reasons, but also from a cost perspective. As the batch sizes of print orders continue to decrease, the disadvantages associated with such conventional methods for the production of printing templates no longer have any bearing on the benefits.

Disclosure of Invention

It is therefore an object of the present invention to provide a printing stencil for providing an image, the production of which avoids the above-mentioned disadvantages of the conventional methods. Furthermore, the present invention is based on the provision of a suitably improved production process.

These objects are achieved by the characterizing embodiments in the claims.

In particular, a printing stencil for providing an image is provided, comprising a substrate having an elastomeric coating, wherein the elastomeric coating carries an engraved pattern, characterized in that the elastomeric coating comprises a hard rubber and has a hardness higher than 40 shore D.

In the present invention, the printing stencil of the present invention includes an elastomeric coating comprising a hard rubber. The elastomeric coating is also referred to hereinafter as a hard rubber layer. In a preferred embodiment, the elastomeric coating consists essentially of a hard rubber. Accordingly, the present invention provides a printing stencil having a printed layer that is a single layer of a hard rubber layer that replaces the two layers (particularly the copper and chromium layers) of conventional printing stencils. Thus, the substrate of the printing stencil of the present invention comprises the elastomeric coating as a single layer. The solid rubber layer allows engraving by engraving techniques known in the intaglio printing industry while completely avoiding the galvanic surface treatment described in the prior art.

The hard rubber of the printing stencil of the present invention may comprise any suitable hard rubber. Preferably, the hard rubber is based on the following: butadiene-acrylonitrile rubber (NBR), carboxylated nitrile rubber (XNBR), ethylene-vinyl acetate copolymer (EVAC), ethylene-vinyl acetate rubber (EVM), hydrogenated acrylonitrile-butadiene rubber (HNBR), perfluoroelastomer (FFKM), ethylene-acrylate rubber (AEM), polyacrylate rubber (ACM), chlorinated polyethylene rubber (CM), chlorosulfonyl polyethylene rubber (CSM), ethylene-propylene-diene rubber (EPDM), ethylene-propylene rubber (EPM), Fluororubber (FKM), epichlorohydrin rubber (CO), epichlorohydrin copolymer rubber (ECO), propylene oxide copolymer rubber (GPO), Butadiene Rubber (BR), Chloroprene Rubber (CR), isobutylene-isoprene rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), Isoprene Rubber (IR), Nitrile Butadiene Rubber (NBR), Natural Rubber (NR), Styrene Butadiene Rubber (SBR), fluorosilicone rubber (FVMQ), methylphenyl silicone rubber (PMQ), methylphenyl vinyl silicone rubber (PVMQ), methyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), polyester urethane (AU), polyether urethane (EU), or a combination thereof.

In a particularly preferred embodiment, the hard rubber is a hard rubber based on butadiene-acrylonitrile rubber (NBR), ethylene-propylene-diene rubber (EPDM), or a combination thereof.

The hardness of the elastomeric coating of the printing stencil according to the invention is higher than 40 shore D, preferably higher than 50 shore D, particularly preferably higher than 70 shore D. The hardness is determined according to DIN ISO 7619-1. Thus, the hard rubber layer of the printing stencil of the present invention differs from conventional elastomers in higher hardness (corresponding to higher modulus of elasticity) and thus exhibits less deformation and recovery (rubber-like elasticity).

The image-providing printing stencil of the present invention may be any suitable printing stencil. Preferably, the image-providing printing stencil is a gravure printing cylinder or plate. Gravure printing cylinders are particularly preferred here, since this is the most common in commercial printing. If the printing stencil of the present invention is a gravure printing cylinder, the substrate is preferably a hollow cylinder, an axial cylinder, or a sleeve as a cylindrical reinforcing structure. The substrate may be composed of any suitable material. By way of example, the substrate may be comprised of plastic or metal. In a preferred embodiment, the substrate is composed of aluminum and/or steel. Particularly preferably, the substrate is a hollow or axial cylinder made of aluminum and/or steel.

The elastomeric coating of the printing stencil of the present invention can have any suitable thickness. Preferably, the thickness of the elastomeric coating is at least 30 μm. In a particularly preferred embodiment, the thickness of the elastomeric coating is in the range of 30 μm to 30 mm. The large range of 30 μm to 30mm allows multiple uses of the printing stencil without the need to reapply rubber. For this procedure, it is only necessary to remove the engraving by grinding after use and to apply a new engraving.

The roughness of the elastomer coating can be adjusted in a suitable manner by grinding and polishing, for example to an average roughness depth Rz of less than 2 μm. In a preferred embodiment of the invention, the surface of the elastomeric coating has a roughness average depth Rz of less than 1 μm. The roughness ensures that the ink film provides lubrication for the doctor blade on the surface of the printing stencil during the subsequent printing process.

Furthermore, the present invention provides a method for producing a printing stencil providing an image, the method comprising (a) providing a substrate, (b) providing an elastomeric coating on the substrate, and (c) providing an engraved pattern on the elastomeric coating by engraving, characterized in that the elastomeric coating comprises a hard rubber and has a hardness higher than 40 shore D.

The image-providing printing template produced by the method may be any suitable printing template. Preferably, the image-providing printing stencil is a gravure printing cylinder or plate. Gravure printing cylinders are particularly preferred here, since this is the most common in commercial printing.

In the method of the present invention, a substrate is first provided (step (a)). If the printing stencil produced by the method of the invention is a gravure printing cylinder, the substrate is preferably a hollow cylinder, an axial cylinder or a sleeve as a cylindrical reinforcing structure. The substrate may be composed of any suitable material. By way of example, the substrate may be comprised of plastic or metal. In a preferred embodiment, the substrate is composed of aluminum and/or steel. Particularly preferably, the substrate is a hollow or axial cylinder made of aluminum and/or steel.

In step (b) of the method of the present invention, an elastomeric coating is provided on the substrate. This can be achieved by conventional methods. In a preferred embodiment of the method of the invention, step (b) comprises the partial steps of (b.1) covering the substrate with an elastomer or elastomer mixture, (b.2) vulcanization of the elastomer or elastomer mixture to form a hard rubber, (b.3) removing excess hard rubber by a turning procedure, and (b.4) removing material by grinding from the surface of the elastomer coating.

Covering the substrate with the elastomer or elastomer mixture in step (b.1) may be achieved, for example, by winding the calendered sheet onto the substrate. Alternatively, the elastomer or elastomer mixture may likewise be extruded onto the substrate. By way of example, this can be achieved by means of a ring extruder. Furthermore, the substrate may be covered by tape covering or by a knife coating/dipping procedure from a solution of the elastomer or elastomer mixture. The layer thicknesses used in the coating procedure allow the desired or desired final layer thickness to be achieved after vulcanization and grinding.

The elastomer or elastomer mixture to be applied is preferably: butadiene-acrylonitrile rubber (NBR), carboxylated nitrile rubber (XNBR), ethylene-vinyl acetate copolymer (EVAC), ethylene-vinyl acetate rubber (EVM), hydrogenated acrylonitrile-butadiene rubber (HNBR), perfluoroelastomer (FFKM), ethylene-acrylate rubber (AEM), polyacrylate rubber (ACM), chlorinated polyethylene rubber (CM), chlorosulfonyl polyethylene rubber (CSM), ethylene-propylene-diene rubber (EPDM), ethylene-propylene rubber (EPM), Fluororubber (FKM), epichlorohydrin rubber (CO), epichlorohydrin copolymer rubber (ECO), propylene oxide copolymer rubber (GPO), Butadiene Rubber (BR), Chloroprene Rubber (CR), isobutylene-isoprene rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), Isoprene Rubber (IR), Nitrile Butadiene Rubber (NBR), Natural Rubber (NR), Styrene Butadiene Rubber (SBR), fluorosilicone rubber (FVMQ), methylphenyl silicone rubber (PMQ), methylphenyl vinyl silicone rubber (PVMQ), methyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), polyester urethane (AU), polyether urethane (EU), or a combination thereof.

In a particularly preferred embodiment, butadiene-acrylonitrile rubber (NBR), ethylene-propylene-diene rubber (EPDM), or a combination thereof is used.

The vulcanization of the elastomer or elastomer mixture and the formation of the hard rubber in step (b.2) may be achieved by any conventional method. The hard rubber is obtained here by crosslinking of the elastomer or elastomer mixture. By way of example, the vulcanization may be carried out in an autoclave. In a preferred embodiment, the substrate covered with the elastomer or elastomer mixture may also be wrapped prior to vulcanization. This additional step is advantageous in terms of an optimized vulcanization.

The hardness of the hard rubber obtained after vulcanization is greater than 40 Shore D, preferably greater than 50 Shore D, particularly preferably greater than 70 Shore D. The hardness is determined according to DIN ISO 7619-1.

The removal of excess hard rubber by the turning procedure in step (b.3) can likewise be achieved by any conventional method.

The grinding of the elastomer coated surface in step (b.4) is preferably carried out by means of a rotary diamond cutting device ("Polishmaster") in order to achieve the final dimensions therefrom. The elastomeric coating obtained by the process of the present invention may have any suitable thickness. Preferably, the thickness of the elastomeric coating after grinding is at least 30 μm. In a particularly preferred embodiment, the thickness of the elastomeric coating is in the range of 30 μm to 30 mm.

Likewise, the roughness of the elastomer coating can be adjusted in a suitable manner by grinding, for example to a mean roughness depth Rz of below 2 μm. In a preferred embodiment of the invention, the average roughness depth Rz of the surface of the elastomeric coating after grinding is lower than 1 μm.

Furthermore, another possibility is to additionally produce a specific grinding effect on the surface of the elastomer coating by means of, for example, two grinding stone wheels. This is advantageous because this type of specific grinding effect then allows the printing ink to act as a lubricating film between the squeegee and the printing stencil. However, unlike the conventional method, this step is not necessary. Since the hard rubber with a hardness above 70 shore D still contains an elastic component, the doctor blade can achieve sealing and a clear print even without an additional specific abrasive effect of the surface.

In step (c) of the method of the present invention, an engraved pattern is provided on the elastomeric coating by engraving. The engraving procedure preferably uses electromechanical engraving or laser engraving.

In the case of electromechanical engraving, a diamond stylus cuts the cell into a printing template. If the printing stencil is a gravure printing cylinder, the diamond stylus cuts the unit into a rotating cylinder; here, the sliding foot can hold the stylus at a constant distance from the drum. The arrangement and size of the cells determines the subsequent printed image. Electromechanical engraving produces cells having a depth of, for example, about 45 to 55 μm.

Particular preference is given to using laser engraving. The laser engraving produces a cell depth of, for example, about 35 to 45 μm, and therefore the application speed of the image can be increased by up to 75% compared to electromechanical engraving.

In a preferred embodiment, quality control may also be performed after engraving is complete. This quality control is usually carried out before delivery and in particular the print-out properties and also the surface quality are checked.

The method of the present invention has a number of advantages over conventional methods of producing printing templates. In particular, the present invention avoids electroplating methods, which are disadvantageous for reasons related to cost and environment. Furthermore, the method of the invention requires significantly fewer steps to produce the printing stencil of the invention, since it also requires only one coating to be applied. Furthermore, the method of the invention also offers the possibility of using the prior art. The user does not need to incur any additional capital expenditure.

Furthermore, the present invention provides a method for intaglio printing comprising (a) providing the inventive printing stencil described above, (b) applying ink onto a surface of the printing stencil, and (c) transferring the ink from the surface of the printing stencil onto a printable substrate.

The invention will now be explained in more detail with reference to working examples.

Drawings

Detailed Description

A black HNBR mixture with the following properties was produced:

color CA.9005RA L

Hardness: 77D Shore A

Density: 1.245g/cm³

The unvulcanized rubber mixture was provided in a uniform form as a stretched calendered sheet having a thickness of about 1.2mm and wound on a hollow aluminum drum. The unvulcanized rubber has little tackiness and can therefore be successfully wound.

Vulcanization was then carried out at a temperature of 135 ℃ for a period of 16 hours. The material was then slowly cooled to avoid separation effects.

The non-finished dimensions of 143.39mm were then turned using a lathe cutter. Here, the rate of penetration is limited to 50mm/min and the surface temperature is monitored to ensure that it is in the range of 40 to 50 degrees celsius.

The elastomer coated hollow aluminum cylinder was then polished. This was achieved by two-step fine polishing to reach a final size of 143.24 mm. The surface after fine polishing has an average roughness depth Rz of less than 0.6 μm.

The surface was then ground to adjust the average roughness depth Rz of the surface to 0.7 to provide a layer of lubricating ink under the blade.

The hardness of the elastomeric coating was 82 shore D.

A 120 ° diamond stylus was then used for electromechanical engraving. Wear of the contact pin is continuously monitored.

FIG. 1 shows a schematic view of aA photomicrograph of the engraved surface is shown. The quality of the cut profile/cell edge corresponds to the quality of a conventional printing stencil with a copper coating.

The gravure cylinder thus produced was used for gravure printing tests.

FIG. 2A micrograph of the resulting print is shown.

The ink density of the resulting print was 1.7. Hue and area coverage are satisfactory.

Finally, wear tests were performed by printing using a Moser proofing press with a soft MDC blade. Print quality up to 150000 lineal meters is satisfactory. The requirement is only 50000 linear meters. Thus, the gravure printing cylinder shows low wear.

In summary, the printing effect of the hard rubber coated gravure cylinder is as good as that of conventional copper coated and hard chrome plated gravure cylinders.