JP3013189U - Offset blanket for varnish coat - Google Patents

Abstract

(57) [Summary] [Structure] The bottom layer is the non-stretchable layer 2, the top layer is the printing rubber layer 5, and the offset blanket 1 is provided with the peelable adhesive layer 3 between these layers. . [Effects] The non-stretchable layer 2 prevents misalignment between the recessed portion 6 of the offset blanket 1 and the non-varnished portion of the printing medium during varnishing. Further, the printing rubber layer 5 prevents the ink on the printing medium from being transferred onto the offset blanket 1.
Further, the peelable adhesive layer 3 makes it possible to easily form the concave portion 6 corresponding to a portion of the printing medium to which the varnish coating is not applied.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a varnish coat offset blanket used for printing catalogs, books, and the like.

[0002]

[Problems to be solved by conventional techniques and devices]

 In printed matter such as catalogs and books, a varnish coat may be applied to the surface of the printed matter by using the offset printing method in order to obtain a glossy surface. Such a varnish coat may be applied to the entire surface of the printed matter, but a varnish coat is often applied only to a predetermined part of the surface.

As a method for applying a varnish coat only to a predetermined portion of the surface of the printed matter, as shown in FIG. 4, an offset blanket 13 having a recess 63 formed on the surface is wound around a cylinder 7 and the varnish transferred from the varnish plate 8 is used. A method of transferring onto a printing medium is used. In this method, the concave portion 63 is formed at a portion corresponding to a portion of the printed material 9 on which the varnish coating is not applied, whereby the varnish coating can be applied only to a part of the printed material 9.

However, since the offset blanket 13 is generally stretchable, the offset blanket is likely to be misaligned between the recessed portion 63 of the offset blanket and the non-varnished portion of the printing medium 9, and the non-varnished portion is likely to occur. May be misaligned. Therefore, conventionally, a resin plate having no elasticity has been used as an offset blanket for varnish coating. The resin plate is produced, for example, by forming a photoresist on a photosensitive resin, exposing it, and removing an uncured portion to form a recess.

However, since the resin plate has a high hardness, when the offset blanket made of the resin plate is strongly pressed against the printing medium 9, the ink already printed on the printing medium 9 will not be printed on the resin printing plate. There is a possibility that a so-called reverse trapping phenomenon will occur in which the image is transferred to. An object of the present invention is to provide an offset blanket for a varnish coat, which is free from misalignment between the concave portion of the offset blanket and a non-varnished portion of the printing medium during the varnish coating process and does not cause reverse trapping phenomenon. Is.

[0006]

[Means for Solving the Problems]

 The offset blanket for varnish coating according to claim 1 for achieving the above object, the lowermost layer is a non-stretchable layer, the uppermost layer is a printing rubber layer, and at least a peelable adhesive layer is provided between these layers. It is characterized by having. In the varnish coat offset blanket according to the second aspect, a peelable adhesive layer is formed on the non-stretchable layer.

The offset blanket for varnish coating according to claim 3 is formed on an adhesive layer from which the printed rubber layer can be peeled off. The offset blanket for varnish coating according to claim 4 has at least two support layers between the printed rubber layer and the non-stretchable layer, and adhesives between any two of the support layers. Layers have been formed.

[0008]

[Action]

 According to the above configuration, by providing a peelable adhesive layer between the non-stretchable layer and the printed rubber layer and cutting up to this adhesive layer, the recess can be easily formed, and at the same time, the bottom layer can be formed. Since the expansion and contraction of the offset blanket is prevented by the non-expansion layer provided on the sheet, no positional deviation occurs between the concave portion and the printing medium. However, since the printing rubber layer is provided on the uppermost layer, the hardness is not high unlike the conventional resin plate, and the reverse trapping phenomenon can be prevented from occurring during the varnish coating process.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings showing embodiments. FIG. 1 is a sectional view showing an embodiment of the present invention. The offset blanket 1 is formed by laminating an adhesive layer 3, a support layer 4, and a printing rubber layer 5 on a non-stretchable layer 2 in this order. Further, in this figure, the concave portion 6 is formed by cutting the upper part from the boundary surface between the non-stretchable layer 2 and the adhesive layer 3.

The non-stretchable layer 2 is made of a metal thin plate having no stretchability such as an aluminum alloy thin plate. For the non-stretchable layer 2, a metal plate such as iron or copper, a synthetic resin having no stretchability, or the like can be used in addition to an aluminum alloy, and is usually formed to have a thickness of 0.1 to 0.5 mm. To be done. The pressure-sensitive adhesive layer 3 is made of an acrylate-based pressure-sensitive adhesive or the like and can be easily peeled off when forming the recesses 6. This adhesive layer 3 is capable of maintaining adhesiveness for a certain period of time, and is different from a curable adhesive. The term "adhesiveness" as used herein means that it is easily peeled off when the recess 6 is formed, but is not peeled off during the varnish coating process. The adhesive layer 3 is usually formed with a thickness of 0.02 to 0.2 mm. The adhesive layer is preferably formed on the non-stretchable layer or the support layer from the viewpoint of easy peeling.

The support layer 4 is formed by impregnating a base cloth such as cotton cloth with a rubber material such as acrylonitrile-butadiene rubber (NBR). For the base cloth, rayon, polyester or the like can be used in addition to cotton cloth, and as the rubber material, chloroprene rubber or the like can be used in addition to NBR. The support layer 4 is prepared by adding a vulcanizing agent or the like to rubber and coating the base fabric with an appropriate coating means such as a blade coating method, and usually has a thickness of 0.15 to 0.8 mm. Is formed by.

The printing rubber layer 5 is made of NBR or the like, and since varnish is carried on the surface of the printing rubber layer 5, it is possible to apply a varnish coat on the material to be printed. In addition to NBR, chloroprene rubber, polyurethane rubber, polysulfide rubber, silicone rubber and the like can be used for the printed rubber layer 5. The printed rubber layer 5 is prepared by adding a vulcanizing agent or the like to rubber, kneading, molding, and vulcanizing, and is usually formed to have a thickness of 0.2 to 3.0 mm.

FIG. 2 is a sectional view showing another embodiment of the present invention. The offset blanket 11 is formed by laminating a support layer 4, an adhesive layer 3, and a printing rubber layer 5 on the non-stretchable layer 2 in this order. Further, in this figure, the upper part is cut off from the boundary surface between the support layer 4 and the adhesive layer 3 to form the recess 61. The non-stretchable layer 2, the support layer 4, the adhesive layer 3 and the printed rubber layer 5 are the same as those used in the embodiment of FIG.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention. The offset blanket 12 is formed by laminating a support layer 4, an adhesive layer 3, a support layer 41, and a printing rubber layer 5 on the non-stretchable layer 2 in this order. Further, in this figure, the upper portion is cut off from the boundary surface between the support layer 4 and the adhesive layer 3 to form a recess 62. The non-stretchable layer 2, the support layers 4, 41, the adhesive layer 3 and the printed rubber layer 5 are the same as those used in the embodiment of FIG.

In the case of forming a portion on the surface of the printed matter that is not subjected to varnish coating, the recessed portions 6, 61, 62 are formed on the surface of the offset blankets for niscoating 1, 11, 12 of the present invention. The recesses 6, 61, 62 are formed by cutting the adhesive layer 3 of the offset blanket from above the portion corresponding to the varnish-free portion of the printing medium.

As a method for forming the recesses 6, 61, 62, first, an offset blanket is attached to a cylinder, and ink of a pattern including a pattern or a pattern corresponding to a non-varnished portion of an object to be printed is removed from the plate. There is a method of transferring to the surface of the offset blanket, then cutting from the surface of the offset blanket to the adhesive layer along the pattern with a cutter knife, and peeling the part corresponding to the pattern from the blanket to form a recess. The recess may be produced by removing the offset blanket from the cylinder.

In addition to the above method, the recesses can be formed by a method of designing and cutting the pattern with a computer (CAD / CAM). In this case, the surface of the flat offset blanket to the adhesive layer is cut by CAD / CAM, and the portion corresponding to the above pattern is peeled from the blanket to form a recess.

As shown in FIGS. 1 to 3, the offset blankets 1, 11 and 12 in which the recesses 6, 61 and 62 are formed are mounted on the cylinder and subjected to varnish coating to confirm the occurrence of the reverse trapping phenomenon. did. This varnish coating treatment was performed for 1 hour by rotating at a rotation speed of 10,000 rpm. Also, the occurrence of the reverse trapping phenomenon was visually confirmed.

On the other hand, the same test was performed using an offset blanket made of a negative type photosensitive resin plate (PG plate manufactured by Toray Industries, Inc.). The recesses in the offset blanket were formed by forming a photoresist on the surface of the resin plate, exposing it for 90 seconds, washing it with acetone, and eluting the unexposed portion. When this was used and varnish coating was performed in the same manner as described above, a reverse trapping phenomenon frequently occurred.

[0020]

[Effect of device]

 According to the present invention, a peelable adhesive layer is formed between the non-stretchable layer and the printing rubber layer, and the recess can be easily formed by cutting the adhesive layer from above. Further, since the lowermost layer of the offset blanket is the non-stretchable layer, there is no displacement between the concave portion of the offset blanket and the portion of the printing medium to which the varnish coating is not applied. Further, since the uppermost layer of the offset blanket is the printing rubber layer, it is possible to prevent the ink on the substrate to be transferred onto the offset blanket, that is, the reverse trapping phenomenon.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an offset blanket for varnish coating of the present invention in which a concave portion is formed.

FIG. 2 is a sectional view showing another embodiment of the offset blanket for varnish coating of the present invention in which a concave portion is formed.

FIG. 3 is a cross-sectional view showing still another embodiment of the offset blanket for varnish coating of the present invention in which a concave portion is formed.

FIG. 4 is a schematic view showing a varnish coating method using a conventional offset blanket.

[Explanation of symbols]

 1 Offset blanket 2 Non-stretchable layer 3 Adhesive layer 4 Support layer 5 Printing rubber layer

Claims (4)

[Scope of utility model registration request] 1. The lowermost layer is a non-stretchable layer, the uppermost layer is a printed rubber layer, at least an adhesive layer is provided between these layers, and the adhesive layer is peelable. Offset blanket for varnish coat. 2. The offset blanket for varnish coating according to claim 1, wherein a peelable adhesive layer is formed on the non-stretchable layer. 3. The offset blanket for varnish coating according to claim 1, wherein the printed rubber layer is formed on a peelable adhesive layer. 4. At least two support layers are provided between the printed rubber layer and the non-stretchable layer, and an adhesive layer is formed between any two of the support layers. Offset blanket for varnish coat according to 1.