JP6784583B2 - Blanket for printing - Google Patents

Description

The present invention relates to a blanket for printing.

In offset printing, generally, dampening water and ink are supplied to a blanket-mounted cylinder through a plate, and then a printed matter supplied between the blanket cylinder and the impression cylinder or between the opposite blanket cylinders. Printing is performed by transferring the ink on the blanket to.

At this time, if the separation property (paper release property, paper ejection property) between the blanket surface and the printed matter such as paper is poor, the printed matter wraps around the blanket surface or curls, causing a problem in transporting the printed matter. Sometimes. In order to improve this separation property, a technique of irradiating the blanket surface with ultraviolet rays is disclosed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 51-37706

However, as disclosed in Patent Document 1, for example, when the blanket surface printing layer is irradiated with ultraviolet rays to modify the surface printing layer, the action of the modification extends only to the outermost surface of the surface printing layer and its vicinity. Absent. As a result, for example, when the blanket surface is worn due to long-term use, the effect of releasability becomes insufficient. Further, in the case of surface rubber having excellent weather resistance such as EPDM, the effect when irradiated with ultraviolet rays may be insufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a printing blanket having excellent releasability (paper releasability, paper ejection property) between a blanket surface and a printed matter such as paper. And.

In order to achieve such an object, the printing blanket of the present invention includes a base layer and a surface printing layer located on the base layer and containing a rubber component, and the surface printing layer has an ultrahigh molecular weight. It was configured to contain polyethylene.

As another aspect of the present invention, the ultra-high molecular weight polyethylene is configured to be in a fine particle state.
Further, as another aspect of the present invention, the ultra-high molecular weight polyethylene is configured such that the average particle size thereof is 200 μm or less.
Further, as another aspect of the present invention, the content of the ultra-high molecular weight polyethylene in the surface printing layer is in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the rubber component of the surface printing layer. And said.

Further, as another aspect of the present invention, the surface printing layer is configured to contain a silicone-based additive in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the rubber component of the surface printing layer. ..

Further, as another aspect of the present invention, the surface printing layer has ethylene propylene rubber (EP), ethylene propylene diene rubber (EPDM, EPT), nitrile butadiene rubber (NBR), and nitrile butadiene isoprene rubber as the rubber component. The configuration was such that at least one of NBIR), butyl rubber (IIR), carboxylated NBR (XNBR), and polysulfide rubber was contained.

According to the present invention, it is possible to provide a blanket for printing having excellent releasability (paper releasability, paper ejection property) between the blanket surface and a printed matter such as paper.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the printing blanket of the present invention. FIG. 2 is a schematic view showing a coated paper used for measuring the releasability, FIG. 2 (A) is a plan view of the coated paper, and FIG. 2 (B) is an arrow shown in FIG. 2 (A). It is a side view of the coated paper seen from the D direction. FIG. 3 is a schematic view of a state in which the coated paper shown in FIG. 2 is placed on the blanket surface as viewed from the side. FIG. 4 is a schematic view of how the coated paper placed on the blanket surface is peeled off as shown in FIG. 3 from the side view. 5A and 5B are schematic views showing a coated paper in which no curl is generated when the coated paper is peeled off from the blanket surface, FIG. 5A is a plan view of the coated paper, and FIG. 5B is a plan view of the coated paper. It is a side view of the coated paper seen from the arrow F direction shown in FIG. 5A. 6A and 6B are schematic views showing a coated paper in which curl is slightly generated when the coated paper is peeled off from the blanket surface, FIG. 6A is a plan view of the coated paper, and FIG. 6B is a view. It is a side view seen from the arrow G direction shown in 6 (A). FIG. 7 is a schematic cross-sectional view showing a coated paper that is curled and has a cylindrical shape when the coated paper is peeled off from the blanket surface.

An embodiment of the present invention will be described with reference to the drawings. It should be noted that the drawings are schematic or conceptual, and the dimensions of each member, the ratio of the sizes between the members, etc. are not necessarily the same as the actual ones, and may represent the same members, etc. However, the dimensions and ratios may differ from each other depending on the drawing. In addition, in the drawings attached to the present specification, the shape, scale, aspect ratio, etc. of each part may be changed or exaggerated from the actual product in order to facilitate understanding.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the printing blanket of the present invention. In FIG. 1, the blanket 11 of the present invention includes a surface printing layer 13 containing a rubber component on one surface of the base layer 12.

The base layer 12 constituting the blanket 11 is, for example, a base cloth such as cotton, polyester fiber, polyvinyl alcohol fiber, aramid fiber, polyethylene terephthalate (PET) film, polyphenylene sulfide (PPS) film, polyethylene naphthalate (PEN) film, etc. It may be a resin film or the like. The thickness of the base layer 12 can be appropriately set in the range of, for example, 0.2 to 2.8 mm.

The base layer 12 may be a laminate in which a plurality of base fabrics are laminated via an adhesive rubber layer, or a compression layer is interposed between the base fabrics constituting such a laminate. You may. The number of base fabrics constituting the laminated body can be appropriately set, and for example, it can be set to about 2 to 5 sheets. Examples of the rubber component of the adhesive rubber layer constituting the laminate include ethylene propylene rubber (EP), ethylene propylene diene rubber (EPDM, EPT), nitrile butadiene rubber (NBR), and nitrile butadiene isoprene rubber (NBIR). Examples thereof include butyl rubber (IIR), carboxylated NBR (XNBR), and polysulfide rubber, and one of these can be used alone or in combination of two or more.

Further, as the material of the compression layer, the material used for the conventional blanket can be used, for example, a multilayer woven fabric, a non-woven fabric, or a foamed structure sheet in which fine particles having a hollow structure are contained in a rubber material. A foamed structure sheet (sponge rubber) or the like having a hollow structure provided with a foaming agent or the like can be used. The compression layer is not limited to the one interposed between the base fabrics, and may be located between the base layer 12 and the surface printing layer 13.

The surface printing layer 13 constituting the blanket 11 contains ultra-high molecular weight polyethylene together with a rubber component. As the rubber component contained in the surface printing layer 13, a conventionally known rubber material for blanket can be used, for example, ethylene propylene rubber (EP), ethylene propylene diene rubber (EPDM, EPT), nitrile butadiene rubber ( NBR), nitrile butadiene isoprene rubber (NBIR), butyl rubber (IIR), carboxylated NBR (XNBR), polysulfide rubber, etc., and one of these can be used alone or in combination of two or more. can do.

The ultra-high molecular weight polyethylene contained in the surface printing layer 13 may be a powder, and the average particle size thereof is 200 μm or less, preferably 100 μm or less, and more preferably 70 μm or less. The ultra-high molecular weight polyethylene usually refers to polyethylene having a molecular weight of 20,000 to 300,000 increased to 500 to 7 million.

The content of such ultra-high molecular weight polyethylene in the surface printing layer 13 can be in the range of 1 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the rubber component of the surface printing layer. If the content of ultra-high molecular weight polyethylene is less than 1 part by weight, the releasability (an index indicating the ease of separating the printed matter from the blanket surface) may be insufficient, and if it exceeds 50 parts by weight, the blanket is manufactured. Workability at times may deteriorate.

Further, the surface printing layer 13 may contain a silicone-based additive together with the rubber component and the above-mentioned ultra-high molecular weight polyethylene. The content of the silicone-based additive in the surface printing layer 13 can be in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the rubber component of the surface printing layer 13. If the content of the silicone-based additive is less than 1 part by weight, high wear resistance may not be exhibited in the surface printing layer 13, which is not preferable. Further, if the content of the silicone-based additive exceeds 30 parts by weight, swelling due to ink may occur, and for example, when the printing plate is switched, the influence of the previous printing plate may remain, which is not preferable. .. Examples of the silicone-based additive contained in the surface printing layer 13 include a graft copolymer of silicone and acrylic, high molecular weight silicone, and the like.

Examples of the graft copolymer of silicone and acrylic include a graft copolymer of polyalkylsiloxane and a methacrylic acid alkyl ester / methacrylic acid hydroxyalkyl ester copolymer, and polyalkyl siloxane and methacrylic acid alkyl ester / alkyl acrylate. Examples thereof include a graft copolymer of an ester copolymer and a graft copolymer of a polyalkylsiloxane and an alkylmethacrylic acid ester copolymer. The content of such a graft copolymer of silicone and acrylic in the surface printing layer 13 is preferably in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the rubber component of the surface printing layer 13 as described above. Is in the range of 2 to 20 parts by weight. Examples of such a graft copolymer of silicone and acrylic include Charine R-170S and Charine R-170 manufactured by Nissin Chemical Industry Co., Ltd.

Further, as the high molecular weight silicone, for example, a silicone containing siloxane as a main component in the range of 65% by weight or more, preferably 65 to 75% by weight can be mentioned, and the content in the surface printing layer 13 is as described above. As described above, the range is 1 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 100 parts by weight of the rubber component of the surface printing layer 13. This high molecular weight silicone may contain silica as an accessory component in the range of 25 to 35% by weight. Examples of such high molecular weight silicone include pelletized high molecular weight silicone and the like, and examples thereof include GENIOPLAST PELLET S manufactured by Asahi Kasei Wacker Silicone Co., Ltd.

Such a surface printing layer 13 may be formed directly on one surface of the base material 12, or may be formed via an adhesive rubber layer. The adhesive rubber layer is, for example, ethylene propylene rubber (EP), ethylene propylene diene rubber (EPDM, EPT), nitrile butadiene rubber (NBR), nitrile, similar to the adhesive rubber layer constituting the base material of the above-mentioned laminate structure. Examples thereof include butadiene isoprene rubber (NBIR), butyl rubber (IIR), carboxylated NBR (XNBR), and polysulfide rubber, and one of these can be used alone or in combination of two or more. , The thickness of the adhesive rubber layer can be appropriately set.

The thickness of the surface printing layer 13 can be appropriately set in the range of, for example, 0.17 to 0.65 mm, preferably 0.25 to 0.65 mm. Further, the surface printing layer 13 may have a multi-layer structure, and in this case, at least the outermost surface layer contains ultra-high molecular weight polyethylene as described above. The thickness of the outermost surface layer in the surface printing layer 13 having such a multilayer structure can be appropriately set in the range of, for example, 0.05 to 0.64 mm.

According to the present invention, it is possible to realize a printing blanket having excellent separation properties (paper release property, paper ejection property) between the blanket surface and a printed matter such as paper.

The above-described embodiment is an example, and the printing blanket of the present invention is not limited thereto. For example, an appropriate amount of a silane coupling agent may be added to the surface printing layer 13. The amount of the silane coupling agent added can be appropriately set. The amount of the silane coupling agent added can be set, for example, in the range of 0.1 to 15 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the rubber component of the surface printing layer 13.

Next, the present invention will be described in more detail with reference to Examples.
<Making a blanket>
An NBR-based rubber glue for a compression layer containing acrylic hollow fine particles (organic thermal expansion microballoons) was applied to one surface of the base cloth as the second layer cloth and dried. Further, NBR-based rubber glue for the adhesive rubber layer was applied to one surface of the base cloth as the first layer cloth and dried. Next, the glued surfaces of the above two base cloths were pasted together.

Next, the NBR-based rubber glue for the adhesive rubber layer was applied to the other surface of the base cloth as the second layer cloth bonded as described above and dried. Further, NBR-based rubber glue for the adhesive rubber layer was applied to one surface of the base cloth as the third layer cloth and dried. Next, the glued surface of the base cloth as the second layer cloth and the glued surface of the base cloth as the third layer cloth were bonded together. After that, vulcanization is performed by pressurizing and heating to have a base cloth of the first layer cloth to the third layer cloth, and a compression layer is provided between the base cloth of the first layer cloth and the base cloth of the second layer cloth. A base layer having a thickness of 1.6 mm was obtained.

On the other hand, 10 kinds of rubber compositions (unvulcanized state) for the surface printing layer of the compositions 1 to 10 shown in Tables 1 and 2 below were dissolved in a toluene solvent to prepare a surface rubber paste. These 10 kinds of surface rubber glues were applied to the base cloth as the first layer cloth constituting the base layer prepared as described above, and dried. Then, can vulcanization was carried out at 140 ° C. for 7 hours to form a surface printing layer, and the surface printing layer was polished to prepare blankets (Samples 1 to 10).

In addition, blankets (Samples 11 to 14) were prepared in the same manner as the blankets of Samples 1 to 10, except that the rubber compositions for the surface printing layer were four types of compositions 11 to 14 shown in Table 3 below. did. However, for the rubber compositions (unvulcanized state) for the four types of surface printing layers of compositions 11 to 14, these are dissolved in a mixed solvent of toluene and methyl isobutyl ketone (MIBK), and the surface rubber paste is used. Was prepared.

The abbreviations of the compounding ingredients shown in Tables 1, 2 and 3 below are as follows. The numerical values shown in Tables 1, 2 and 3 represent parts by weight.
-Ultra high molecular weight polyethylene A: Mitsui Chemicals Co., Ltd. Miperon (registered trademark) XM-221U
(Average particle size about 25 μm)
-Ultra high molecular weight polyethylene B: Mitsui Chemicals, Inc. Miperon (registered trademark) PM-200
(Average particle size about 10 μm)
-Silicone-based additive: Charine (registered trademark) R170S manufactured by Nissin Chemical Industry Co., Ltd.
-Plastic agent A: Polyether ester-based plasticizer-Plastic agent B: Ester-based / Vulcanization accelerator A: Thiuram-based vulcanization accelerator / Vulcanization accelerator B: Sulfenamide-based vulcanization accelerator / Vulcanization promotion Agent C: Dithiocarbamic acid-based vulcanization accelerator / vulcanization accelerator D: Sulfenamide-based vulcanization accelerator

<Blanket evaluation>
For each blanket (Samples 1 to 14) prepared as described above, the separation property of the printed matter from the surface printed layer, the ink transfer density, and the Taber wear index were measured by the following methods and conditions, and the results are shown in Table 4 below. It was shown to.

(Measurement method / condition of separation)
A film on which an ink film was formed was prepared by coating an ink solution dissolved in butyl acetate. The film was placed on the blanket surface, the blanket on which the film was placed was pressed using a press machine, and then the film was peeled off from the blanket surface at a constant speed.

Next, a square coated paper 50 having a diagonal length of about 77 mm connecting the two pairs of vertices (P, Q) is placed on the surface of the blanket 11 on which the ink film is transferred from the film (FIGS. 2 and 3). (See), the blanket on which the coated paper 50 was placed was pressed using a press machine. Then, as shown in FIG. 4, the coated paper 50 is 20 ± 5 mm so as to move the coated paper 50 from the surface of the blanket 11 from one pair of vertices P of the coated paper 50 toward the other pair of vertices Q facing the pair of vertices. At a rate of / sec, the blanket 11 was peeled in a direction of 90 ° to 120 ° (for example, in the case of 90 °, the direction indicated by the arrow E) with respect to the surface of the blanket 11.

After peeling the coated paper 50 from the surface of the blanket 11, the length from one pair of vertices P to the other pair of vertices Q was measured with a caliper. The longer this length is, that is, the closer it is to the above-mentioned diagonal length (about 77 mm), the more curl is not generated in the coated paper 50, or curl is generated so as to be recognized as almost no curl. This means that the release property (paper release property / paper discharge property) is excellent.

For example, as in the case of the coated paper 50'after peeling shown in FIG. 5, when almost no curl is generated, the length L1 of the two opposite vertices (P, Q) of the coated paper 50'is the diagonal length 77 mm. The length is the same as or close to 77 mm in length. Further, when curling is slightly generated as in the peeled coated paper 50 ”shown in FIG. 6, the length L2 of the two opposite vertices (P, Q) of the coated paper 50 ”is the coat shown in FIG. The length is shorter than L1 on paper 50'.

On the other hand, when the coated paper has a cylindrical shape due to curling as in the peeled coated paper 50 "'shown in FIG. 7, the lengths of the two pairs of vertices (P, Q) are replaced. , The diameter of the cylindrical coated paper 50 "'is measured, and the degree of curl is determined from the measured diameter. In this case, it is clear that the diameter is shorter than the diagonal line of 77 mm, and the occurrence of curl can be visually confirmed.

(Measurement method / condition of ink transfer density)
An ink transfer test was performed on each of the produced blankets, and the ink transfer concentration transferred to the paper was measured using a reflection densitometer (QUIKdens manufactured by X-Light Co., Ltd.). The higher the density, the better the ink transfer property.

As the ink used for measuring the separation property and the ink transfer density, "FLASH DRY (registered trademark) Calton X Kurenai M (ultraviolet curable ink manufactured by Toyo Ink Co., Ltd.)" was used for samples 1 to 10. For Samples 11 to 14, "WEB DRY (registered trademark) Leo X Kurenai (oil-based ink manufactured by Toyo Ink Co., Ltd.)" was used.

(Measurement method / condition of Taber wear index)
Using the prepared blanket, a Taber wear test was carried out with a load of 500 g and a wear wheel H-18 in accordance with JIS K6264. The lower the Taber wear index, the less the blanket wear.

From the results in Table 4, the blankets (Samples 2 to 5, Samples 7 to 10, Samples 12 to 14) containing any of the ultrahigh molecular weight polyethylenes A and B in the surface printing layer were blankets (Sample 1, Sample 6, It was confirmed that the releasability (paper releasability / paper ejection property) was improved as compared with the sample 11) without impairing the ink transfer property. Further, from the results in Table 4, it was confirmed that even a blanket containing EPDM, which has excellent weather resistance, as a main component has a sufficient effect of improving the releasability (paper releasability / paper ejection property).
Furthermore, based on the comparison of the Taber wear index between the blankets (Samples 1 to 5) and the blankets (Samples 6 to 10), the addition of the silicone-based additive to the surface printing layer has a releasability (paper releasability / paper ejection property). It was confirmed that it is effective in suppressing the wear of the blanket without impairing the effect of the improvement of).

It can be used for blanket-based printing.

11 ... Blanket 12 ... Base layer 13 ... Surface printing layer

Claims (6)

A base layer and a surface printing layer located on the base layer and containing a rubber component are provided.
A blanket for printing, wherein the surface printing layer contains ultra-high molecular weight polyethylene. The printing blanket according to claim 1, wherein the ultra-high molecular weight polyethylene is in a fine particle state. The printing blanket according to claim 1 or 2, wherein the ultra-high molecular weight polyethylene has an average particle size of 200 μm or less. Any of claims 1 to 3, wherein the content of the ultra-high molecular weight polyethylene in the surface printing layer is in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the rubber component of the surface printing layer. The printing blanket according to item 1. Any one of claims 1 to 4, wherein the surface printing layer contains a silicone-based additive in the range of 1 to 30 parts by weight with respect to 100 parts by weight of the rubber component of the surface printing layer. The printing blanket described in. The surface printing layer contains ethylene propylene rubber (EP), ethylene propylene diene rubber (EPDM, EPT), nitrile butadiene rubber (NBR), nitrile butadiene isoprene rubber (NBIR), butyl rubber (IIR), and carboxylated rubber components. The printing blanket according to any one of claims 1 to 5, which contains at least one of NBR (XNBR) and polysulfide rubber.

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