EP2758250A1

EP2758250A1 - Multi-layered structure form for use as printing blanket or printing plate for relief printing, in particular flexo printing

Info

Publication number: EP2758250A1
Application number: EP12750592.3A
Authority: EP
Inventors: Stefan Füllgraf; Armin SENNE; Torsten RASCHDORF; Gabriele Lindenthal
Original assignee: ContiTech Elastomer Beschichtungen GmbH
Current assignee: ContiTech Elastomer Beschichtungen GmbH
Priority date: 2011-09-19
Filing date: 2012-08-22
Publication date: 2014-07-30
Anticipated expiration: 2032-08-22
Also published as: SI2758250T1; DE102011053748A1; EP2758250B1; US20140202348A1; HUE036927T2; WO2013041319A1

Abstract

The present invention relates to a multi-layered structure form (1) for use as printing blanket or printing plate for relief printing, in particular flexo printing, comprising a first layer (10) having a vulcanizate on the basis of at least one elastomer, and at least an additional layer (30, 40). The first layer (10) can be stripped off (strippable) from the additional layer (30, 40).

Description

description

Multilayer sheet for use as a blanket or printing plate for high-pressure, in particular flexographic printing

The invention relates to a multilayer sheet material for use as a blanket or printing plate for high-pressure, in particular flexographic printing. The multilayer sheet has a first layer comprising a vulcanizate based on at least one elastomer and at least one further layer. The invention further relates to a method for producing such a multilayer sheet. The printing technique deals with the duplication of artwork by

Printing inks from a printing form to a print carrier, such as e.g. Paper, cardboard or plastic are transferred. This includes the high pressure technique, in which the printing elements are raised above the depressions on the printing form, i. the image areas of the printing form are higher than the non-image areas. The increased trained printing elements or image locations are provided with the ink, whereby they form the artwork, which can then be transferred to the print substrate to image the artwork there.

The printing form may be a multilayer sheet which serves as a

Pressure plate or can be formed as a blanket. In both cases, the multilayer sheet has, as the uppermost layer, a printed layer which is used for printing

Print carrier is aligned. The print layer may be provided on a strength support layer. If the print layer and, if appropriate, the reinforcement layer are flexible, for example by photopolymers, this is referred to as the flexographic printing process. Further layers between the printing layer and the optional reinforcement layer are possible in the high-pressure process, for example in the form of a compressible layer. Also a plurality of compressible layers and reinforcing layers may be provided, which are preferably arranged alternately. All layers form

conventionally bonded together, i. the adjacent layers are adhesively bonded together, i. cohesively by e.g. Adhesive or by vulcanization.

The formation of the elevated printing elements or image locations of the printing original can be effected by laser engraving in the high-pressure process and in particular in the flexographic printing process. For this purpose, the printing layer on photopolymers. Among photopolymers, photo-curing plastics such as e.g. Epoxy resins understood. Alternatively, the raised printing elements or image areas may also be processed by mechanical processing such as e.g. be produced by milling on the print layer.

Such a printing layer of photopolymer is described for example in the patent EP 1 315 617 Bl. In this case, the printing layer has an elastomeric

Binder, a polymerizable compound, a photoinitiator or a

Photoiniatorsystem and a finely divided filler, for example, a fumed oxide (silica, titanium oxide, aluminum oxide). In this case, by means of laser light, the material of the print layer at the points that later the printing elements or

Image areas form, irradiated and the remaining areas are not. By irradiation, for example with actinic light, in the areas of the later printing elements or image areas, the full-surface crosslinking (vulcanization) of this printing layer takes place, so that a printing relief is engraved into the printing layer by means of a laser. The area of the printing layer formed in this way is then also referred to as a relief layer, printing relief, printing form or printing original after the laser treatment. In the non-irradiated areas no crosslinking of the photopolymers takes place, so that they can be washed out after the irradiation, for example, and form the depressions or non-image areas of the printing layer. The disadvantage here, for example, that the production of a printing plate is very expensive due to several steps. In most cases, an adjustment of the Contact pressure when printing at different speeds due to the dynamic stiffness of the material required. Furthermore, the photopolymeric printing layer or printing original is characterized by low color transfer. Also, errors may occur in mounting the exposed photopolymer sheet. Finally, the training as a roll goods limits, so that the end user must have different formats in stock.

In order to overcome these disadvantages, the publication WO 2010 121 887 Al teaches to form the polymeric material of the printing layer as a vulcanizate, i. to produce the complete crosslinking of the polymers by vulcanization of the entire printing layer, so that a laser engraving of the printing elements or image locations and

subsequent washing out of the non-irradiated areas of the depressions or

Non-imaging of the print layer is no longer required. Rather, provided with a vulcanized printing layer multilayer sheet of the

Publication WO 2010 121 887 AI in the form of a blanket or a

Printing plate delivered as roll goods to the customer. This mounts the rolls on a sleeve (adapter, impression cylinder). Then, the ablation of the printing layer is performed in the areas which are to form the depressions or non-image areas of the printing layer, e.g. by a laser or mechanical processing such as e.g. Milling connected with a subsequent cleaning, so as to form the artwork.

In conjunction with today's laser technologies can in the vulcanizate a

Print layer engraved with grid points with different depths and shapes are introduced. The removal of the vulcanizate of the printing layer to form the depressions or non-image areas of the artwork takes place quickly, cleanly and without solvent. It is guaranteed a 100% fit and reproducibility. Of great economic importance is the fact that the customer in the creation of the printing form according to the teaching of the publication WO 2010 121 887 AI requires significantly fewer process steps. In this sense, the term "vulcanizate" is the term for products or product components produced by vulcanization of a vulcanisable polymer mixture, in this case the printing layer The polymer mixture contains a rubber component or several rubber components A vulcanizate is distinguished by elastic properties The type of rubber is cross-linked by means of sulfur (eg NR) or peroxides (eg EPDM) .The thermal vulcanization at temperatures of 130 to 200 ° C is of particular importance

Cold vulcanization or radiation vulcanization can be used. Information on usable vulcanizates can be found in the published patent application WO 2010 121 887 A1, the disclosure of which is also part of the present invention.

With regard to the mixture ingredients, reference is made in particular to the published patent application DE 100 04 632 A1, the disclosure of which is likewise part of the present invention. In the method of published patent application WO 2010 121 887 A1, the surface of the printing layer is completely formed before the removal as a printing element or image position, i. a vulcanized unprocessed print layer would transfer color to the print carrier over its entire surface during printing since the print copy is only produced by the removal that has not yet taken place. This is disadvantageous, since the areas of the print layer, which are not part of the artwork, must be removed completely and above all over a large area. If these are larger contiguous areas, they must nevertheless be removed with the very fine machining of a laser or milling cutter intended to form the fine printing master, i. Large surfaces must be time-consuming removed with a very fine tool. In particular, the proportion of the surface of the print layer, which after the removal of the printing elements or

Bildstellen form, comparatively small compared to the surface to be removed of the wells or non-image areas of the print layer, so the cost, especially the time required, even further and thus the cost, for example on the appropriate machine usage, especially the machine use times and the machine and tool wear. Furthermore, the printing original is regularly washed or cleaned in printing processes in order to keep the artwork clean and a possible formation of unwanted printing elements or image locations in the removed area of the depressions or

To avoid non-image spots caused by color or dirt particles. Under this

The background is the use of created by the known methods by laser or Fräsaserabtrag print templates disadvantageous because the areas generated by the removal of the depressions or non-image areas of the print layer color or dirt particles provide a relatively good substrate for adhesion. The object of the present invention is therefore to provide a multilayer sheet of the type described above, in which the aforementioned disadvantages are overcome, in particular the print original can be generated easier and faster than previously known, in particular the wells or non-image areas of the artwork easier and faster than previously known can be generated.

The object is achieved by the features of the characterizing part of claim 1 and the method according to claim 13. Advantageous developments are described in the respective subclaims. Thus, the present invention relates to a multilayer sheet according to the preamble of claim 1, whose first layer is peelable from the further layer (strippable).

The invention is based on the finding that it is very complicated, in particular time-consuming, the formation of the depressions or non-image areas of the print layer for producing the print original by abrading processing, e.g. by

Laser ablation or milling to produce. Furthermore, a relatively rough background is produced by the abrasive machining. Therefore, according to the present invention, these portions of the first layer of the multi-layer sheet which can be used as a print layer of a blanket or a printing plate can be peeled off from the at least one further layer. The print layer may be due to their Composition also as elastomer layer or due to their geometric

Arrangement also be referred to as cover layer. Preferably, an elastomeric material is used for the production of the printing layer, which under the

Product name AA6FIZ is manufactured and sold by Gummiwerk Kraiburg GmbH & Co. KG.

Thus, according to the invention, only the areas of the print layer are elaborately processed by means of mechanical removal, in which also elevated printing elements or image locations are to be formed as a print original. The remaining areas, which are conventionally likewise expensive to machine by means of mechanical removal in order to create the depressions or non-image areas of the print layer, are easily and quickly stripped or stripped from the at least one further layer according to the invention.

This is also advantageous because the substrate, which after removal or

Stripping on the at least one further layer is left, is smoother and smoother than after a machining. In this way, dye or dirt particles can adhere worse to this surface. This allows

Impurities in the areas of the recesses generated by the removal or

Non-image areas of the print layer can be avoided or at least reduced, whereby the expense of cleaning or washing the print original can be reduced.

On the one hand, laser ablation or mechanical removal in the area of the original can first be carried out, and then the excess area of the printed layer can be separated from it and stripped off (stripped). On the other hand, first the

unworkable area of the print layer from the remaining area of the

Printing layer separated and stripped (stripped) and then the artwork in the remaining area of the print layer are created by laser ablation or mechanical removal. In this case, the first-mentioned approach is to be preferred, since the surface to be stripped later (to be stripped) of the printing layer gives mechanical stability during the removal processing of the print original, in particular in the marginal areas of the print original. The peelability or strippability of the first layer is made possible according to the invention in that the adhesive effect is formed between the first layer and the at least one further layer in such a way that it enables on the one hand a secure adhesion of the first layer to the at least one further layer and, on the other hand, the first Layer under the action of a tensile force substantially in the direction A, that is, perpendicular to the plane of the multi-layer sheet, can be stripped or stripped from the at least one further layer. The separation of the print layer into an area where the elevated formed

Printing elements or image locations are or can be, and an area that can be removed by peeling, can be done by cutting, eg manually with a carpet knife or the like or even with a machine with a suitable cutting tool or other release agent such as water jet or Sandblast cutting, cutting, milling or the like. Thus, it is also conceivable to have this separation carried out by the mechanical removal processing, for example by means of a laser or milling cutter, by removing the first layer to a depth, thereby producing the separation of the first layer into the two regions. In the context of this invention, the term "strippable" or "strippable" is to be understood as meaning that a layer has tensile forces acting essentially in direction A, ie perpendicular to the plane of the multilayer sheet, of its background, such as at least one further layer can be replaced. In this case, the detachment takes place as completely as possible by the tensile forces, ie leave without residues or with as few residues on the ground. However, it is sufficient for the invention, if the first layer is at least so detached from the at least one further layer, that the remaining residues of the first layer on the at least one further layer still wells or non-image areas of the printed layer and thus not designed as increased Print elements or image areas act, ie no color transferred to the print carrier. According to one aspect of the invention, the multilayer sheet has a

Interlayer, which has a lower separation resistance T than the first layer. It is advantageous hereby that the peelability or strippability of the first layer is ensured by the at least one further layer. In this way, the intermediate layer in terms of separation resistance T is the weakest link in the structure of the multilayer sheet, so that at a sufficiently large tensile force substantially in the direction A, the intermediate layer is yielded first and the first layer of the at least one further layer can be stripped or stripped.

In this case, the intermediate layer has a separation resistance T, which is between 50% and 5% of the separation resistance T of the first layer, preferably between 40% and 5% of the

Separation resistance T of the first layer, more preferably between 30%> and 5% of the separation resistance T of the first layer, most preferably between 20%> between 5% of the separation resistance T of the first layer. In absolute terms, the intermediate layer has a separation resistance T between 1.2 N / mm and 0.1 N / mm, preferably a separation resistance T between 1.0 N / mm and 0.1 N / mm, particularly preferably a separation resistance T between 0 , 8 N / mm and 0.1 N / mm, most preferably a separation resistance T between 0.6 N / mm and 0.4 N / mm.

The term of the separation resistance T in the sense of the standard DIN 53 530 is to be understood, which deals with the examination of organic materials in the form of a separation test on adhesively bonded fabric layers. For the purposes of DIN 53 530, the term "separation resistance T" is to be understood as meaning the quotient of the separation force F determined according to the separation test of this standard and the sample width B. Accordingly, the separation resistance T is measured as force per unit length in N / mm and Alternatively, however, in another way, the separation resistance T of

Intermediate layer can be reduced compared to the first layer, for example by the Material property of the intermediate layer and / or the surface finish and / or their coating.

In this context, the term "intermediate layer" is to be understood as meaning a layer or else coating which is provided between the first layer and the at least one further layer of the multi-layered fabric. strippable first layer and the substrate from which the first layer is to be stripped, and the reduced separation resistance T of the intermediate layer between the first layer and the substrate is opposite that of the first layer, in other words substantially when a tensile force is applied in the direction of A the

Intermediate layer of this tensile force and tears. The further structure or the procurement of the multilayer sheet is so far not relevant for the present invention, as long as this effect is maintained.

According to a further aspect of the invention, the further layer and / or the intermediate layer comprises a vulcanizate based on at least one elastomer.

It is advantageous here that the same production processes, in particular vulcanization, can be used by the use of a vulcanizate both for the first layer and for the intermediate layer and thus the production costs are kept low. Also, the crosslinking of the elastomers of the first layer and the intermediate layer results in good adhesion of the first layer to the at least one further layer. Although this liability is inventively canceled by tensile forces, however, a reliable and permanent adhesion of the region of the multi-layer sheet, which is to serve as a printing template or a printing plate in a blanket, required to print the template reliably and over a longer period than blanket or printing plate to use, since this is the

Can not separate artwork from its background. In particular, when using a blanket on cylinder printing presses significant centrifugal forces act on the Print template, which the adhesion between the first layer and the intermediate layer must certainly withstand over a longer period of time.

According to a further aspect of the invention, both the first layer and the further layer and / or the intermediate layer each have a vulcanizate based on the same elastomer.

It is advantageous here that in this way the first layer and the intermediate layer are resistant to swelling against the same media. This is particularly advantageous in the preparation or use of printing blankets and printing plates, as by a

Swelling of the first layer or the intermediate layer of the blanket or the

Pressure plate, the delimitation between the elevated trained printing elements or image locations of the artwork and the wells or non-image areas of

Print template can be reduced or completely prevented. Thus, by swelling a layer, especially in the edge region, where media can penetrate laterally into the layers, there may be an increase in a depression or non-image area, so that this area likewise comes into contact with ink during printing and these unintentionally come into contact with the print substrate transfers, ie increased by the swelling

Forming print elements or image locations of the artwork, which are not provided. In this way, the print template can be changed and a print image of this can be generated, which makes the print carrier and thus the print template unusable.

Such swelling is known in the use of adhesives which are used to bond individual layers of a multilayer sheet together. However, since known adhesives are not dimensionally stable and on the

In order to swell, it is advantageous to use a vulcanizate based on the same elastomer as an intermediate layer instead of adhesives in order to bond the individual layers of a multilayer sheet, in particular the first layer and the intermediate layer, to one another in an adhesive but strippable manner. According to one aspect of the invention, the vulcanizate of both the first layer and the further layer and / or the intermediate layer can be removed with a laser, preferably a carbon dioxide laser, a fiber laser or a diode laser.

The use of a laser is advantageous because it is already commonly used for

Production of printing templates can be used and thus the multilayer sheet according to the invention can be processed by means of existing manufacturing facilities. In particular, eg carbon dioxide lasers (also called carbon dioxide lasers or C0 ₂ lasers) are among the most common and most powerful industrially used lasers. They are primarily used for material processing because they are relatively efficient and inexpensive. Likewise, fiber lasers are characterized by a robust construction, a high beam quality and efficiency, which is why fiber lasers are suitable for many applications. For example, fiber lasers with high performance can be used for eg

Welding, cutting or ablation are used. The use of a diode laser is also preferred, since diode lasers are distinguished by their very compact design, a comparatively high electrical / optical efficiency, comparatively long maintenance intervals, the possibility of coupling and transporting the radiation in optical cables, and a very long service life. As a result, the acceptance of the multilayer sheet according to the invention by the customer is increased. The laser ablation can be done both by laser ablation and laser desorption.

According to a further aspect of the invention, the intermediate layer comprises particles which are at least partially enclosed by the material of the intermediate layer.

It is advantageous here that these partially or completely enclosed bodies reduce the amount of the elastomer material which is present in the intermediate layer between the first layer and the at least one further layer by their own volume and thus reduce the separation resistance T of the intermediate layer. In this case, the reduction of the separation resistance T, for example, by the shape, the volume or the surface texture of the body are affected. Also, this may be due to the thickness of the intermediate layer in direction A or the proportion of body at the

Composition of the intermediate layer done. Likewise, the material of the intermediate layer, in particular its elastomeric material, substances are added which the release force T of the intermediate layer, in particular the elastomer of the

Interlayer, so far reduce that the desired separation force resistance T is reached.

As materials of the bodies, e.g. Glass, polymer, metal, minerals, graphite or PTFE (polytetrafluoroethylene) into consideration. The bodies are preferably made of polymer, more preferably of thermoplastic polymer, in particular of polystyrene, in particular of expandable polystyrene, as known under the brand name "Styropor ™." According to one aspect of the invention, the particles of the intermediate layer are at least partially spherical in shape.

In this embodiment, it is advantageous for the body to be relatively easy to peel off materials which adhere to a spherical surface. In this way, a defined and reproducible cracking behavior of the intermediate layer can be achieved, so that the first layer can be defined and reproducibly stripped or stripped from the substrate. Preferably, no or as little residues as possible are left on the substrate, at least in such a small and low degree in direction A, that these residues do not distort the artwork.

According to a further aspect of the invention, the further layer is as

Reinforcing layer, preferably formed as a dimensionally stable reinforcement layer.

In this preferred embodiment, it is advantageous that the at least one further layer as a reinforcement layer increases the stability of the multi-layered structure and makes it more resilient, more robust and easier to handle. It can the reinforcing layer has one or more different types of reinforcements such as one or more textile structures such as knitted fabric, knitted fabric or fabrics of various configurations. These may for example be embedded in a polymeric material, preferably in a vulcanized polymeric material, ie be surrounded by it or, in contrast to the printing layer, have such a surface, or a corresponding surface for the peelable

To form print layer. As a strength support layer, a film such as e.g. a polymeric film (e.g., polyamide film) or metal foil is used. In a fabric having many layers and at least two strength layers, a combination of a textile structure and a film or a

Foil composite be implemented.

It is particularly preferred that the reinforcement layer is dimensionally stable

Reinforcing layer is formed by e.g. Aluminum, steel or a PET or PE film has. It is particularly advantageous in this particularly preferred embodiment that such a dimensionally stable reinforcement layer can cause a particularly high stability of the multilayer sheet.

According to one aspect of the invention, a compressible layer is arranged between the first layer and the further layer, preferably between the intermediate layer and the further layer.

In this way, the first layer is applied as a print layer directly on a compressible layer. This is advantageous because in this way the compressible layer - also called compression layer - avoiding a Walk through

Volume reduction in the pressure zone and compensation of

Empress differences serves. For the compressible layer it is crucial that it does not expand when compressed, i. that their volume during

Squeezing actually downsized, so no sideways spreading

Dislocations arise. For example, microspheres made of plastic in a rubber compound or a microporous cell structure can be used here enclosed gas chambers (foams). The relevant materials are in particular polyurethanes, crosslinked polyethylenes, polypropylenes, NBR, Neoprene and EPM. The modulus of elasticity is usually in the range of 1 MPa to 1000 MPa.

With regard to further details of the compressible layer, reference is made in particular to the publications EP 0 844 100 B1 and EP 2 070 717 A1, the disclosure of which is part of the present invention.

According to a further aspect of the invention, the first layer comprises a textile

Sheet, preferably an open fabric, especially preferably a nonwoven on.

This is advantageous because the textile fabric, preferably the open textile fabric, particularly preferably the nonwoven fabric, can be penetrated by the material of the first layer and thus combine the properties of the material of the first layer and the textile fabric. In this way, mechanical forces, e.g. act on the first layer during a mechanical processing or during stripping (stripping), are absorbed by the textile fabric. Thus, in this way the first layer can be brought to a desired thickness by grinding. In this case, the textile fabric may be a knit, knitted or woven fabric. The textile fabric is preferably an open textile fabric, particularly preferably a nonwoven fabric.

For example, the mechanical forces acting on a grinding process up to a thickness of about 1 mm can still be absorbed by the vulcanized material of the first layer. With a thinner first layer, however, this can no longer be ensured, so that it is expedient to embed an open textile fabric in the material of the first layer, which then at least partially absorbs the mechanical forces. Furthermore, regardless of the layer thickness, it is advantageous to introduce an open textile fabric, preferably a nonwoven fabric, into the material of the first layer, since it can also at least partially absorb the tensile forces during stripping of the first layer. According to another aspect of the invention, at least one layer comprises a magnetic or magnetizable material. This is advantageous because in this way the multilayer sheet by means of magnetic force on a substrate such as a printing cylinder or a

Pressure plate holder can be held. Here are usually so far

Adhesive used. However, they can swell, i. change their shape in particular in height and thereby raise areas of the blanket or the printing plate. As a result, depressions or non-image areas can be raised in such a way that they act unintentionally as elevated pressure elements or image areas and thus change the artwork and make the print substrate unusable, since instead of the intended

Print image is created another. According to a further aspect of the invention, the intermediate layer has a lower separation resistance T than the first layer and is designed to be compressible.

This has the advantage that the peelability (strippability) and compressibility properties can be combined in a single layer. In this way, the cost of producing a multi-layer sheet, which these two properties in the form of separate and sequential

has to be produced layers reduced. This can be the

Reduce manufacturing costs. Further, the multi-layer sheet can be made thinner, since the separate compressible layer can be dispensed with.

The implementation of this property combination is made possible by the design of the intermediate layer. For example, this can be provided with a greater layer thickness on the at least one further layer than in an embodiment in which the intermediate layer is intended essentially to serve only for the peelability or strippability of the regions of the print layer which are to form the depressions or non-image areas. Due to this greater layer thickness, the intermediate layer acts in the areas in where it is not stripped or stripped, ie in the areas of the print template, which are to form the printing elements or image locations of the artwork, compressible. In this way, one and the same layer can perform two functions in the two different areas of the print layer.

The peelability or strippability can be achieved by the measures that have been previously described for this purpose. The compressibility of the

Intermediate layer may e.g. can also be achieved by these measures, i. by a combination of inclusions in an elastomer-containing material or by the material properties of the intermediate layer itself. However, it is also possible to introduce into the intermediate layer materials or elements which serve essentially only for compressibility and not or only insignificantly the peelability or strippability of the intermediate layer influence, in particular only reduce so much that the peelability or strippability is still guaranteed safe.

According to a further aspect of the invention, the vulcanizate of the first layer and / or the intermediate layer is a vulcanized thermoplastic-free rubber mixture containing at least one rubber component as well as mixing ingredients. In particular, ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), (partially) hydrogenated nitrile rubber (HNBR), fluororubber (FKM), chloroprene rubber (CR )

Natural rubber (NR), styrene butadiene rubber (SBR), isoprene rubber (IR), butyl rubber (HR), bromobutyl rubber (BIIR), chlorobutyl rubber (CUR), butadiene rubber (BR), chlorinated polyethylene (CM), chlorosulfonated Polyethylene (CSM), polyepichlorohydrin (ECO), ethylene-vinyl acetate rubber (EVA), acrylate rubber (ACM), ethylene-acrylate rubber (AEM), silicone rubber (VMQ), fluorinated methyl silicone rubber (MFQ), perfluorinated propylene rubber (FFKM),

Perfluorocarbon rubber (FFKM) or polyurethane (PU) to be used, wherein the aforementioned rubber types without waste or in a blend, in particular in conjunction with one of the aforementioned rubber types are used. The rubber component EPM, EPDM, SBR, BR, CR, NR or NBR is preferably used. The usual mixture ingredients comprise at least one crosslinker or a

Crosslinking system (crosslinking agent and accelerator). Other compounding ingredients are usually still a filler and / or a processing aid and / or a plasticizer and / or an aging inhibitor and optionally further additives (for example color pigments). In this regard, reference is made to the general state of rubber mixing technology.

According to a further aspect of the invention, alternatively to the vulcanized thermoplastic-free rubber mixture, the vulcanizate of the first layer and / or the intermediate layer used is a thermoplastic vulcanizate comprising at least one thermoplastic component, at least one rubber component which is at least partially crosslinked, and mixing ingredients.

Preferred Thermplastkomponente are polyethylene (PE), polypropylene (PP), polystyrene, polyamide (PA) or polyester (PES). EPDM, EPDM, SBR, BR, CR, NR or NBR, in particular in a blend-free design, can be used in particular as rubber components. With regard to the mixture ingredients refer to the aforementioned mixing technology, as is known in particular from the teaching of the published patent application DE 100 04 632 AI, whose disclosure also

Part of the present invention is.

According to a particularly preferred aspect of the invention, the multilayer sheet according to the invention comprises at least the following layers in the following order, starting from the printing side, starting opposite to the direction A:

1. a first layer, preferably printed layer of a blanket or a

Printing plate,

2. intermediate layer, which tears when removing or stripping the first layer, 3. compressible layer or compression layer, and

4. Reinforcing layer, preferably dimensionally stable reinforcement layer.

In this case, further layers may be provided between the individual layers mentioned above, or may be the lower layer, i. the

Reinforcing layer, further layers follow. Thus, the lowermost layer may be followed by at least one further compressible layer and a reinforcement layer in this order, or further such combinations of layers. However, it is preferred that the first layer is peelable or strippable through the intermediate layer directly in contact with the compressible layer and the compressible layer rests directly on the reinforcement layer. Such a structure is advantageous from the said at least four layers, because in this way a multilayer sheet is provided, the first layer of which can be stripped or stripped and whose compressive surface is compressively mounted on a reinforcing member, preferably a dimensionally stable reinforcing member.

The present invention also relates to a process for producing a

multilayer sheet for use as a blanket or printing plate for high-pressure, in particular flexographic printing, with at least the following steps:

Vulcanizing a first layer comprising at least one elastomer in a first step,

mechanically working the first layer to produce a predetermined layer thickness in a further step, and

Applying the first layer to at least one further layer in a further step,

wherein the first layer is strippable from the at least one further layer. This process is based on the finding that the first layer of a multilayer sheet according to the invention is simpler, faster and cheaper can be prepared when the first layer is first vulcanized separately and also the desired layer thickness is brought before it is then applied to at least one further layer, in particular a reinforcement, particularly preferably to a dimensionally stable reinforcement.

Furthermore, dimensionally stable reinforcements such as e.g. Steel and aluminum sheets in a thickness suitable for the manufacture of printing blankets or printing plates, only available in certain widths. Thus, it is advantageous to use the first layer of a

multilayer sheet separately by mechanical working such as e.g. To bring grinding to the desired thickness (thickness), then bring to the dimensions of the dimensionally stable strength member and only then on the dimensionally stable

Apply strength carrier. Tighter tolerances of the layer thickness (layer thickness) can be achieved here than with products on the market.

According to one aspect of the invention, the step of applying the first layer to at least one further layer of the method for producing a

multilayer sheet the following steps:

Applying a vulcanizable intermediate layer on one side of the first layer and / or on one side of the further layer,

Merging the first layer with the further layer with their

Intermediate layer or its intermediate layers, and

Vulcanization of the multilayer sheet.

Providing the strippability of the first layer relative to the at least one further layer in this manner is advantageous because it allows the use of adhesives such as e.g. Adhesive can be dispensed with. It is particularly preferred if the

Interlayer and the first layer each having a vulcanizate based on the same elastomer. In both cases, swelling of the intermediate layer compared to adhesives can be prevented or at least reduced. There are several options available, the intermediate layer between the first layer and the at least one further layer, for example a

Strength support layer, preferably a dimensionally stable reinforcement layer, or a compressible layer may be provided. Thus, only the first layer on one side can be provided with the vulcanizable material of the intermediate layer, e.g. by brushing or spraying. It is also possible to provide only the at least one further layer on one side with the vulcanizable material of the intermediate layer. It is also possible to provide both the first layer on one side and the at least one further layer on one side with the vulcanizable material of the intermediate layer. In all cases, in a further step, the first layer and the at least one further layer are combined with the respective side provided with the vulcanizable material of the intermediate layer and then vulcanized, so that the intermediate layer as a vulcanized intermediate layer between the first layer and the at least one other Layer forms. For this purpose, the first layer and the at least one further layer can be compressed before and / or during vulcanization.

Several embodiments and further advantages of the invention are described below

Explained in connection with the following figures. It shows:

Fig. 1 is a schematic representation of a multilayer sheet according to a first embodiment of the present invention;

Fig. 2 is a schematic representation of a multilayer sheet according to the first embodiment of the present invention after a first

Processing step;

3 is a schematic representation of a multilayer sheet according to the first embodiment of the present invention after a second processing step;

4 shows a schematic illustration of a multilayer sheet according to the first exemplary embodiment of the present invention after a third processing step; 5 is a schematic representation of a multilayer sheet according to a second embodiment of the present invention;

Fig. 6 is a schematic illustration of a multilayer sheet according to a third embodiment of the present invention;

7 is a schematic representation of a multilayer sheet according to a fourth embodiment of the present invention after a first

Processing step;

8 is a schematic representation of a multilayer sheet according to the fourth embodiment of the present invention after a third processing step;

9 shows a schematic illustration of a multilayer sheet according to the first exemplary embodiment of the present invention after a first production step;

10 shows a schematic representation of a multilayer sheet according to the first exemplary embodiment of the present invention after a second production step;

Fig. 11 is a schematic representation of a multilayer sheet according to the first embodiment of the present invention according to a third

Manufacturing step; and

Fig. 12 is a schematic representation of a multilayer sheet according to the first embodiment of the present invention prior to a fourth

Manufacturing step.

Fig. 1 shows a schematic representation of a multilayer sheet 1 according to a first embodiment of the present invention. The multilayer sheet 1 according to the invention, which can preferably be used as printing blanket 1 or printing plate 1 in high-pressure processes, in particular in flexographic printing processes, has at least one first layer 10 and at least one further layer 30, 40.

The first layer 10 is in the direction A perpendicular to the plane of the blanket 1 and the printing plate 1 as the outermost layer of the multilayer sheet 1 and thus also formed as a printing layer 10 of the blanket 1 and the printing plate 1. As such, the surface 11 of the print layer 10 faces the print carrier (not shown) during printing. The one further layer 30, 40 is preferably formed as a reinforcement layer 40, particularly preferably as a dimensionally stable reinforcement layer 40 and as such may comprise aluminum, sheet steel, PET film or PE film or consist of one of these materials. In this case, the further layer 30, 40 will be considered below as a dimensionally stable reinforcement layer 40, without the invention on this

Restrict embodiment.

The printing layer 10 and the dimensionally stable reinforcement layer 40 are connected to one another in accordance with the invention in such a way that the printing layer 10 is of the dimensionally stable form

Reinforcing layer 40 can be stripped off or stripped.

This can be implemented, for example, in that the printing blanket 1 or the printing plate 1 according to the first exemplary embodiment has an intermediate layer 20 which is formed between the printing layer 10 and the dimensionally stable reinforcing member 40 and bonds them to one another in an adhesive but strippable manner. This adhesive but peelable (strippable) connection between the pressure layer 10 and the dimensionally stable strength member 40 is achieved in the first embodiment of the present invention, characterized in that the intermediate layer 20 comprises a material from which particles 21, which are preferably spherical, at least partially enclosed becomes. These trapped particles 21 reduce the separation resistance T of the intermediate layer 20 with respect to the separation resistance T of the printing layer 10 in such a way that only the intermediate layer 20 ruptures with an attacking tensile force in direction A, but not the printing layer 10.

In this first embodiment, the intermediate layer 20 connects the printing layer 10 directly to the dimensionally stable strength member 40, but are also

Embodiments possible in which the intermediate layer 20, the printing layer 10 with another layer, eg a compressible layer 30 (see Fig. 5) adheres but peelable (strippbar) connects.

Fig. 1 shows at the same time an inventive multilayer sheet 1 as a blanket 1 or printing plate 1 for a high-pressure process, in particular one

Flexographic printing process, before a first processing step to create a

Print original 12, which is to be formed in the form of elevated printing elements 13 or image locations 13 (cf., FIGS. 2 to 6). In this state, the blanket 1 or the printing plate 1 has a flat surface 11 of the printing layer 10 with a predetermined thickness (thickness) and is held over the dimensionally stable reinforcing layer 40, so that the surface 11 of the printing layer 10 can be processed.

Fig. 2 shows a schematic representation of a multilayer sheet 1 according to the first embodiment of the present invention after a first

Processing step. In this first processing step to create a

Print original 12 are removed by means of removal, e.g. can be done by a laser or by a router or the like, the recesses 14 and non-image areas 14 of the printing original 12 are formed, of which then formed the elevated

Lift off printing elements 13 or image locations 13 of the printing original 12.

After this abrading processing, the artwork 12 is in the plane of

Blanket 1 or the pressure plate 1 at its outer edge surrounded by a circumferential and closed outermost recess 15 and outermost non-image point 15, not the formation of the original 12 but the demarcation of the

Print original 12 opposite the surrounding area 17 (see Fig. 3) of the printing layer 10 is used.

Fig. 3 shows a schematic representation of a multilayer sheet 1 according to the first embodiment of the present invention according to a second

Processing step. In this second processing step to create a

Print template 12, the intermediate layer 20 in the outermost recess 15 and the extreme non-image area 15 is severed by a separating depression 16 or cutting depression 16, so that the printing layer 10 is divided into a region which forms the printing original 12 and a further region which represents the region 17 of the printing layer 10 to be stripped off or stripped.

4 shows a schematic representation of a multilayer sheet 1 according to the first exemplary embodiment of the present invention after a third

Processing step. In this third processing step to create a

Print original 12 is deducted or stripped area 17 of the print layer 10 of the dimensionally stable strength member 40. For this purpose, the intermediate layer 20 is provided with a separation resistance T, which is less than that of the printing layer 10 and the dimensionally stable strength member 40, so that the deducted or stripped area 17 of the printing layer 10 of the dimensionally stable reinforcing member 40 as far as possible by traction in the Essentially remove in the direction of A.

In this way, according to the processing steps described in connection with FIGS. 1 to 4, only the region of the printing layer 10 remains on the dimensionally stable reinforcement carrier 40, in which the printing original 12 was formed. The remaining area 17 could according to the invention easily and quickly from the dimensionally stable

Strengtheners 40 are stripped (stripped) instead of having to remove this area by laser processing or mechanical processing time consuming as well as the desired wells 14, 15 or non-image areas 14, 15 of the original 12. This is according to the invention a significant simplification of the production a print template 12 for high pressure, in particular flexographic printing, achieved with the corresponding advantages of the associated time and cost savings.

Alternatively, the order of the processing steps, as described in connection with Figs. 1 to 4, according to the invention also run the other way around. In this case, first, the area 17 through a separation recess 16 or

Cutting recess 16 separated from the later to be processed area of the printing original 12 with the raised printing elements 13 and image locations 13 and deducted or stripped. Only then does the formation of the increased pressure elements 13 or

Image locations 13 of the printing original 12 and their depressions 14, 15 or non-image areas 14, 15 by the erosive processing. 5 shows a schematic representation of a multilayer sheet 1 according to a second exemplary embodiment of the present invention. However, in this second embodiment, the intermediate layer 20 adhesively bonds the print layer 10 to a compressible layer 30, which in turn is adhesively bonded to the dimensionally stable strength support layer 40. In this way, the advantages of a compressible layer 30 in the inventive

multilayer fabrics 1 are introduced.

Fig. 6 shows a schematic representation of a multilayer sheet 1 according to a third embodiment of the present invention. In this third

Embodiment, the printing layer 10 with an open fabric 18, preferably a nonwoven fabric 18 is provided to reinforce the material of the printing layer 10 against mechanical forces. These may e.g. during stripping of the area 17 of the printing layer 10 to be removed or stripped during the abrading processing of the depressions 14 or non-image areas 14 of the original 12, the outermost recess 15 or outermost non-image area 15 of the original 12 and the cutting depression 16 or cutting depression 16 of the outermost recess 15, for example occur by milling or even in the mechanical processing of the printing layer 10 by e.g. Grinding to bring the printing layer 10 to the desired layer thickness. 7 shows a schematic representation of a multilayer sheet 1 according to a fourth exemplary embodiment of the present invention after a first

Processing step. The multilayer sheet 1 of the invention according to the fourth exemplary embodiment, which can preferably be used as printing blanket 1 or printing plate 1 in high-pressure processes, in particular in flexographic printing processes, has at least a first layer 10, a compressible intermediate layer 20 and at least one further layer 30, 40 (cf. Fig. 1). This corresponds to this first Processing step the first processing step of the first embodiment, ie, Fig. 7 shows the blanket 1 or the printing plate 1 before a first

Processing step for creating a printing original 12, which is to be formed in the form of elevated printing elements 13 or image locations 13 (cf., FIGS. 2 to 6).

The peelability or strippability is also effected in the multilayer sheet 1 according to the fourth embodiment by the intermediate layer 20 by means of the particles 21 enclosed in the material of the intermediate layer 20. In this case, the intermediate layer 20 is designed to achieve a compressible effect significantly larger in the direction A dimensioned, i. provided with a larger layer thickness, than in the first to third embodiments. Owing to this greater layer thickness, in the area of the printing layer 10 in which the printing original 12 is formed in the form of elevated printing elements 13 or image sites 13, a compressible effect can be achieved by the intermediate layer 20 without having to provide a separate compressible layer 30, as described with respect to the second embodiment in FIG.

In this case, the larger layer thickness of the intermediate layer 20 in FIG. 7 is indicated schematically by the fact that the enclosed particles 21 are arranged in three horizontal rows. In the real embodiment, however, the entrapped particles 21 will rather randomly disperse and dispose in the material of the intermediate layer 20.

Fig. 8 shows a schematic representation of a multilayer sheet 1 according to the fourth embodiment of the present invention according to a third

Processing step. In this case, this third processing step corresponds to the third

Processing step of the first embodiment according to Fig. 4, i. FIG. 8 shows a multilayer sheet 1 in which the region 17 of the printing layer 10 to be peeled or stripped off has been pulled off the dimensionally stable reinforcement 40. The area of the intermediate layer 20 extending in the direction A below the

Print template 12 is in this case acts as a compressible layer 30 (see Fig .. 5). Here, it is shown schematically in FIG. 8 that, due to the comparatively large layer thickness of the intermediate layer 20, in order to achieve a compressible effect in the region of the printing original 12 in the surrounding area 17 (see FIG

Pressure layer 10 for forming residues of the intermediate layer 20 in the form of projecting in the direction A material residues 22 may come, in which also particles 21 may be included. Such a configuration of the surface of the stripped intermediate layer 20 in the surrounding region 17 may also occur in the first to third embodiments, but is not shown schematically in the corresponding FIGS. 4 to 6 for the sake of clarity. In this case, the protruding material residues 22 in all embodiments in the direction A are formed so small that they do not affect the printing original 12, i. do not act as elevated printing elements 13 or image position 13.

9 shows a schematic representation of a multilayer sheet 1 according to the first exemplary embodiment of the present invention after a first

Manufacturing step. In this first manufacturing step, the material of the first layer 10, which can form the print layer 10 of a blanket 1 or a printing plate 10, is applied to a surface (not shown) and vulcanized. The vulcanized printing layer 10 may be removed therefrom or after a subsequent processing step from the surface. On its upper side 11, which is aligned in the illustration of FIG. 9 in the direction A, the printing layer 10 may have at least slight bumps.

10 shows a schematic representation of a multilayer sheet 1 according to the first exemplary embodiment of the present invention after a second production step. In this second production step, the uneven surface 11 of the printing layer 11 has been processed in order to obtain as flat a surface 11 as possible of the printing layer 10 with a desired layer thickness. In this case, a flat surface 11 is to be understood as meaning a surface 11 of the printing layer 10 which has only elevations, points, ripples and the like to such a small extent that the formation or differentiation of increased form takes place Print elements 13 and image locations 13 of the printing original 12 and depressions 14 or non-image areas 14 of the printing original 12 is not disturbed or impaired by this. The machining can be done mechanically, for example by grinding, brushing, polishing or finishing.

11 shows a schematic representation of a multilayer sheet 1 according to the first exemplary embodiment of the present invention after a third production step. In this third production step, an intermediate layer 20 was applied to the side of the printing layer 10, which lies opposite the upper side 11 of the printing layer 10 in the direction A and thus forms the underside of the printing layer 10. In this embodiment, this intermediate layer 20 has a material from which particles 21, which are preferably spherical, are at least partially enclosed. These trapped particles 21 reduce the separation resistance T of the intermediate layer 20 with respect to the separation resistance T of the printing layer 10 in such a way that only the intermediate layer 20 ruptures with an attacking tensile force in direction A, but not the printing layer 10.

While in FIG. 11 only an application of the material of the intermediate layer 20 to the underside of the printing layer 10 is shown, it is equally possible according to the invention to place the material of the intermediate layer 20 on the side A of the further layer 30, 40 of the multilayer To apply sheet 1, which is to be connected to the printing layer 10 through the intermediate layer 20. Likewise, the material of the intermediate layer 20 also on both the bottom of the

Printing layer 10 and on the aligned in the direction A side of the further layer 30, 40 are applied. The latter can be in the form of uniform or

different thick orders on the respective surfaces of the layers 10, 30, 40 done.

FIG. 12 shows a schematic representation of a multilayer sheet 1 according to the first exemplary embodiment of the present invention before a fourth

Manufacturing step. In this following fourth manufacturing step, the two will now be Layers 10, 40, which are to be connected by means of the intermediate layer 20 adhering to each other but peelable or strippable, compressed in the direction A by means of a contact force F and vulcanized fixed in this state. In this

Vulkanisationsschritt takes place the full-surface crosslinking of the material

Intermediate layer 20. As a result of this fifth manufacturing step, the vulcanization, the multilayer sheet 1 of the blanket 1 or the printing plate 1 according to FIG. 1 is formed.

Alternatively, for the manufacturing steps one to five of Figs. 9 to 12, those of the second and third embodiments may be used instead of the multilayer sheet 1 of the first embodiment.

Thus, for the production of a multilayer sheet 1 of the second

Embodiment in the fourth manufacturing step instead of the dimensionally stable

Reinforcing layer 40 to use a compressible layer 30, which if necessary. In turn, then in other manufacturing steps, e.g. by gluing or also vulcanizing with e.g. a dimensionally stable reinforcement layer 40 can be connected. In this way, after the vulcanization according to FIG. 9, a multilayer sheet 1 is produced, as shown in FIG. 5 after a machining operation.

Further, for producing a multilayer sheet 1 of the third

Embodiment in the first manufacturing step, the open fabric 18, preferably the nonwoven fabric 18 to be embedded in the material to be vulcanized of the printing layer 10 to after vulcanization according to FIG. 9, a multilayer

To obtain sheet 1, as shown in Fig. 6 after an abrasive machining. LIST OF REFERENCE NUMBERS

(Part of the description)

A direction perpendicular to the plane of the multilayer sheet 1

F contact force in direction A

I multilayer sheet, preferably blanket or printing plate 10 printing layer

I I surface of the print layer 10, facing the print carrier during printing 12 print original or print relief of the print layer 10

13 increased trained printing elements or image locations of the printing original 12th

14 depressions or non-image areas of the print original 12

15 outermost recess or outermost non-image point of the printing original 12th

16 separation recess or cutting recess of the outermost depression 15

17 area of the printing layer 10 to be peeled off or stripped

18 open textile fabric, preferably nonwoven fabric

20 intermediate layer

21 particles, in particular hollow spheres or polystyrene balls

22 protruding material residues of the intermediate layer 20th

30 compressible layer, compression layer

40 further layer, in particular reinforcement layer, preferably dimensionally stable reinforcement layer

Claims

claims

1. Multilayer sheet (1) for use as a blanket or

Pressure plate for high pressure, in particular flexographic printing, with

a first layer (10) comprising a vulcanizate based on at least one elastomer, and

at least one further layer (30, 40),

characterized in that

the first layer (10) is removable (strippable) from the further layer (30, 40).

2. A multilayer sheet (1) according to claim 1, further comprising

an intermediate layer (20) having a lower separation resistance T than the first layer (10).

3. Multilayer sheet (1) according to claim 1 or 2,

wherein the further layer (30, 40) and / or the intermediate layer (20) a

Vulcanizate based on at least one elastomer.

4. Multilayer sheet (1) according to one of the preceding claims,

wherein both the first layer (10) and the further layer (30, 40) and / or the intermediate layer (20) each comprise a vulcanizate based on the same elastomer.

5. Multilayer sheet (1) according to one of the preceding claims,

wherein the vulcanizate of both the first layer (10) and the further layer

(30, 40) and / or the intermediate layer (20) with a laser, preferably a

Carbon dioxide laser, a fiber laser or a diode laser can be removed.

6. Multilayer sheet (1) according to one of claims 2 to 5,

wherein the intermediate layer (20) comprises particles (21) derived from the material of

Intermediate layer (20) are at least partially enclosed.

7. Multilayer sheet (1) according to claim 6,

wherein the particles (21) of the intermediate layer (20) are at least partially spherical.

8. Multilayer sheet (1) according to one of the preceding claims,

wherein the further layer (30, 40) is designed as a reinforcement layer (40), preferably as a dimensionally stable reinforcement layer (40).

9. Multilayer sheet (1) according to one of the preceding claims,

wherein between the first layer (10) and the further layer (40),

preferably between the intermediate layer (20) and the further layer (40) a compressible layer (30) is arranged.

10. Multilayer sheet (1) according to one of the preceding claims,

wherein the first layer (10) comprises a textile fabric (18), preferably an open textile fabric (18), more preferably a nonwoven fabric (18).

11. Multilayer sheet (1) according to one of the preceding claims,

wherein at least one layer (10, 20, 30, 40) is a magnetic or

having magnetizable material.

12. Multilayer sheet (1) according to one of the preceding claims,

wherein the intermediate layer (20) has a lower separation resistance T than the first

Layer (10) and is formed compressible.

13. A method for producing a multilayer sheet (1) for

Use as blanket or printing plate for high pressure, especially the

Flexographic printing, with at least the following steps:

Vulcanizing a first layer (10) comprising at least one elastomer in a first step, mechanically working the first layer (10) to produce a

predetermined layer thickness in a further step, and

Applying the first layer (10) on at least one further layer (30, 40) in a further step,

wherein the first layer (10) is peelable (strippable) from the at least one further layer (30, 40).

14. A process for producing a multilayer sheet (1) according to

Claim 13, wherein the step of applying the first layer (10) to at least one further layer (30, 40) comprises the following steps:

Applying a vulcanizable intermediate layer (20) on one side of the first layer (10) and / or on one side of the further layer (30, 40),

Merging the first layer (10) with the further layer (30, 40) with its intermediate layer (20) or intermediate layers (20), and

Vulcanizing the multilayer sheet (1).

15. A method for producing a multilayer sheet (1) according to

Claim 14,

wherein the intermediate layer (20) has a lower separation resistance T than the first layer (10).