WO2017179456A1

WO2017179456A1 - Rubber blanket for printing

Info

Publication number: WO2017179456A1
Application number: PCT/JP2017/013992
Authority: WO
Inventors: 将邦川口
Original assignee: 株式会社金陽社
Priority date: 2016-04-12
Filing date: 2017-04-03
Publication date: 2017-10-19
Also published as: JP6134835B1; JP2017189891A

Abstract

A rubber blanket for printing according to one embodiment includes: a sheet-like base made from metal; a surface rubber layer provided to the front surface of the sheet-like base such that end portions of the sheet-like base are exposed therefrom; and a plastic layer provided to the back surface of the sheet-like base, said back surface being on the reverse side of the surface to which the surface rubber layer is provided. The plastic layer is disposed so as to face or substantially face the surface rubber layer with the sheet-like base interposed therebetween. The front surface of the plastic layer, said surface being on the reverse side of the sheet-like base-side surface thereof, is a roughened surface having an arithmetic mean roughness Ra of from 2.0 μm to 20 μm, and the roughened surface has a pearskin finish.

Description

Rubber blanket for printing

The present invention relates to a rubber blanket for printing.

In offset printing, the print image created on the plate cylinder is transferred from the plate cylinder to the blanket, and further transferred from the blanket to the substrate to be printed.

The blanket has a structure including, for example, a metal plate as a base material and a resin layer or a surface rubber layer provided on the surface of the base material (Japanese Patent Laid-Open No. 03-133695). In addition, a blanket in which a plastic sheet is further provided on the back surface of a metal plate is also known (Japanese Translation of PCT International Publication No. 2010-532727). Such a blanket is attached to the blanket cylinder by winding a metal plate as a base material around the blanket cylinder.

When mounting such a blanket on the blanket cylinder, a plastic sheet is interposed between the metal plate and the blanket cylinder so that the metal plate does not directly contact the blanket cylinder. For this reason, generation | occurrence | production of the damage | wound of a metal plate and a blanket cylinder, and generation | occurrence | production of the rust by the dissimilar metal contact between a metal plate and a blanket cylinder can be suppressed.

In addition, when the blanket is wound around and attached to the blanket cylinder, the plastic sheet directly contacts the blanket cylinder. For this reason, compared with the case where the metal plate of the blanket is brought into direct contact with the blanket cylinder, the friction coefficient is increased, and there is a possibility that the blanket cannot be accurately mounted on the blanket cylinder. As a result, the blanket is displaced during use, and in some cases, the blanket is damaged. Further, there is a risk of peeling off from the blanket cylinder.

For this reason, for example, a method of treating a plastic sheet with talc or a lubricant to reduce the coefficient of friction between the plastic sheet and the blanket cylinder so as to make it easy to mount is performed. However, such a method may increase labor.

An object of the present invention is to provide a printing rubber blanket that is easy to mount on a blanket cylinder, improves handling, and enables accurate positioning to the blanket cylinder.

The printing rubber blanket according to the embodiment includes a metal sheet-like base material, a surface rubber layer provided so that an end of the sheet-like base material is exposed on the surface of the sheet-like base material, and the surface And a plastic layer provided on the back surface of the sheet-like substrate opposite to the rubber layer. The plastic layer is disposed so as to face or substantially face the surface rubber layer with the sheet-like substrate interposed therebetween. The surface of the plastic layer opposite to the sheet-like substrate is a rough surface having an arithmetic average roughness Ra of 2.0 μm to 20 μm. The rough surface has a satin pattern.

FIG. 1 is a diagram illustrating an example of a printing rubber blanket according to an embodiment. FIG. 2 is a schematic view showing an example in which a rubber blanket for printing is wound around a blanket cylinder.

Hereinafter, the rubber blanket for printing according to the embodiment will be described in detail.

The printing rubber blanket according to the embodiment includes a metal sheet-like base material. The surface rubber layer is provided so that the edge part of the sheet-like base material is exposed on the surface of the sheet-like base material. The plastic layer is provided on the back surface of the sheet-like substrate on the side opposite to the surface rubber layer. The plastic layer is disposed so as to face or substantially face the surface rubber layer with the sheet-like substrate interposed therebetween. That is, the surface rubber layer and the plastic layer are provided on the sheet-like base material so as to face each other or substantially face each other across a region excluding the end of the sheet-like base material. The surface of the plastic layer opposite to the sheet-like substrate is a rough surface having an arithmetic average roughness Ra of 2.0 μm to 20 μm, and the rough surface has a satin pattern.

The metal sheet-like base material is made of, for example, stainless steel (for example, SUS). The sheet-like base material preferably has a thickness of 0.1 mm to 0.3 mm, for example.

The edge of the sheet-like substrate that is exposed (projects) from the surface rubber layer and the plastic layer is located on both sides of the rubber layer and the plastic layer even at one end located on one side of the surface rubber layer and the plastic layer. Both ends may be used. The edge part of a sheet-like base material is used in order to fix the rubber blanket for printing to a blanket cylinder.

In the embodiment, both end portions of the sheet-like substrate protrude from both side surfaces of the rubber layer and the plastic layer.

The surface rubber layer can be, for example, the surface rubber layer of any rubber blanket for offset printing known per se. Examples of the surface rubber layer include natural rubber, styrene butadiene rubber, nitrile rubber (NBR), chloroprene, butylene rubber, ethylene propylene rubber, chlorosulfonated polyethylene, silicone rubber or fluorine rubber. However, the surface rubber layer is not limited to these rubbers. The surface rubber layer may be an elastomer compound. The blend may contain any fiber known per se. The surface rubber layer may contain additives such as a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, a reinforcing agent, a filler, and a plasticizer.

The surface rubber layer preferably has a thickness of 0.1 mm to 1.0 mm, for example.

The surface rubber layer can be provided directly on the sheet-like substrate or with one or more base fabric layers, one or more adhesive layers, and one or more compression layers interposed therebetween.

The surface rubber layer, the base fabric layer, the compression layer, and the adhesive layer can be provided by being adhered to a sheet-like substrate using an adhesive or an adhesive tape. Adhesives or adhesive tapes are, for example, thermoplastic polyurethane, polyvinyl chloride, vinyl acetate polymer, thermosetting polyurethane, polyester, polyamide, polyolefin, phenol resin, epoxy adhesive, polyurethane adhesive, polyacrylic adhesive Agent or acrylic PSA.

In a rubber blanket for printing having a base fabric layer between the surface rubber layer and the sheet-like substrate, it is preferable to provide a seal portion on the outer peripheral side surface of the laminate including the adhesive, the base fabric layer, and the surface rubber layer. Such a seal portion prevents the printing rubber blanket from being swollen due to the cleaning liquid soaking in the printing rubber blanket.

As the base fabric layer, for example, a woven fabric or a non-woven fabric can be used. As the constituent material, for example, selected from cotton, wool, hemp, silk, rayon, cupra, acetate, nylon, vinylon, polyester, polyvinyl chloride, acrylic, acrylate, polyimide, carbon fiber, aramid fiber, metal fiber or glass fiber A single material or two or more materials can be used.

The compression layer and the adhesive layer are each obtained, for example, by vulcanizing a rubber compound sheet. Non-polar polymers such as acrylonitrile / butadiene rubber, chloroprene rubber, fluorine rubber, polyurethane rubber, ethylene propylene rubber or butyl rubber can be used as the rubber contained in the rubber compound. In addition to the rubber material, the rubber compound may contain an additive for obtaining a rubber elastic body. Examples of the additive include a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, a reinforcing agent, a filler, and a plasticizer.

The compression layer can be a porous structure such as a sponge or a solid structure. As a method of forming the porous structure, for example, the addition of the microcapsules, methods of use including immersion paper, elution salts, can be employed as foaming agent method.

The thickness of the compression layer may be, for example, 0.1 mm to 1.2 mm.

The seal portion can be formed of, for example, acrylonitrile / butadiene rubber, chloroprene rubber, fluorine rubber, polyurethane rubber, ethylene propylene rubber, butyl rubber, or the like. The seal part may contain compounding agents such as a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, a reinforcing agent, a filler, and a plasticizer.

The plastic layer may be, for example, a polyamide, polyester, polypropylene, polyethylene, polyurethane, polyolefin, phenolic compound, nylon polyvinyl fluoride, polyvinyl chloride or a copolymer containing polyvinyl acetate, or ethylene-acrylic acid, ethylene-methacrylic acid copolymer. Polymer films can be used. As the plastic layer, a film of an ionomer, an acid-modified polymer or an anhydride-modified polymer can be used.

The plastic layer preferably has a thickness of about 0.02 mm to about 0.5 mm.

In the positional relationship between the surface rubber layer and the plastic layer, “substantially opposed” means that one side surface of the corresponding plastic layer is extended to a length of 10 mm or less in the longitudinal direction of the plastic layer with respect to one side surface of the surface rubber layer. It means to move backward.

The surface of the plastic layer opposite to the sheet-like substrate is a rough surface having an arithmetic average roughness Ra of 2.0 μm to 20 μm, and the rough surface has a satin pattern.

A rough surface having a satin pattern can be formed, for example, by subjecting the surface of the plastic layer to polishing or embossing by jetting sand particles.

A satin pattern is a pattern having countless irregular irregularities.

If the Ra value of the rough surface of the plastic layer exceeds 20 μm, the uneven shape of the surface of the plastic layer itself is reflected on the printed surface, which may cause printing failure. When the Ra value is less than 2.0 μm, it is difficult to provide sufficient lubricity between the plastic layer and the blanket cylinder when the plastic layer of the printing rubber blanket is mounted on the blanket cylinder. For this reason, there is a risk of hindering the smooth mounting of the printing rubber blanket to the blanket cylinder. A more preferable arithmetic average roughness Ra is 2.0 μm to 10 μm.

The plastic layer can be provided by adhering to a sheet-like substrate using, for example, the above-described adhesive or adhesive tape.

A primer may be interposed between the sheet-like substrate and the adhesive or adhesive tape, or between the plastic layer and the adhesive or adhesive tape, or both.

Any primer known per se can be used as the primer.

Next, the printing rubber blanket according to the embodiment will be specifically described with reference to FIG. 1A is a plan view of a printing rubber blanket, and FIG. 1B is a cross-sectional view taken along line bb of FIG. 1A.

The printing rubber blanket 1 includes, for example, a rectangular metal sheet-like substrate 2. The surface rubber layer 3 uses an adhesive so that, for example, both end portions of the sheet-like substrate 2, that is, the first end portion 2 a and the second end portion 2 b are exposed on the surface of the sheet-like substrate 2. It is provided by bonding. The plastic layer 4 is provided so that the first end portion 2a and the second end portion 2b of the sheet-like base material 2 are exposed on the back surface of the sheet-like base material 2 on the side opposite to the surface rubber layer 3. . The plastic layer 4 is provided by being bonded to the back surface of the sheet-like substrate 2 using an adhesive. The surface rubber layer 3 and the plastic layer 4 are provided on the sheet-like substrate 2 so as to face each other across an area excluding the first end 2a and the second end 2b of the sheet-like substrate 2. In such a structure, the first end 2 a and the second end 2 b of the sheet-like substrate 2 protrude in the horizontal direction from both side surfaces of the surface rubber layer 3 and the plastic layer 4. The protruding first end 2a and second end 2b of the sheet-like substrate 2 are used to fix the printing rubber blanket 1 to the blanket cylinder.

Next, a procedure when the printing rubber blanket 1 is wound around and attached to the peripheral surface of the blanket cylinder using the first end 2a and the second end 2b protruding from the sheet-like substrate 2 will be described. However, these are only examples and do not limit the present invention.

FIG. 2 (a) is a front view of an example of the blanket cylinder with the blanket attached. FIG. 2B is a cross-sectional view taken along the line cc showing an enlarged view when the blanket is attached to the blanket of FIG. FIG. 2C is a cross-sectional view taken along the line cc showing the state in which the blanket is fixed through the state of FIG.

The blanket cylinder 100 includes a bottomed cylindrical body 101 and

shaft portions

110a and 110b extending from the ends 102a and 102b of the body 101. A gap 103 extending in the direction from one end to the other end in parallel with the trunk body axis is opened toward the inside of the trunk body 101 on the circumferential surface of the trunk body 101 (FIG. 2A). A blanket fixing mechanism 130 is disposed from the gap 103 to the inside of the trunk body 101. The blanket fixing mechanism 130 extends in the direction from one end to the other end of the trunk body 101 in parallel with the trunk body axis, and has two fixing

shafts

120a and 120b penetrating the bottom at at least one end of the trunk body 101. Is provided. The fixed

shafts

120a and 120b exposed from the trunk main body 101 can include gripping portions (not shown) that rotate them about the respective shafts.

The rubber blanket 1 for printing is fixed to the trunk body 101 as follows. First, the first end 2 a of the sheet-like substrate 2 in the printing rubber blanket 1 is inserted into the gap 103 and set to the fixing portion 121. Thereafter, the second end 2b of the sheet-like base material 2 is passed over the peripheral surface of the trunk body 101 and inserted into the gap 103 so that the surface with the surface rubber layer 3 is on the front side, and set to the fixing portion 122. . In this example, the first end 2a is a leading edge (a tail end), and the second end 2b is a trailing edge (a tail end).

The fixed

portions

121 and 122 are provided on the fixed

shafts

120a and 120b, and extend from one end of the trunk body 101 to the other end along the respective shafts. The region where the fixing

portions

121 and 122 are disposed preferably has a sufficient length for fixing the printing rubber blanket 1. For example, the region may be as long as the trunk body length or shorter than the trunk body length. The fixing

portions

121 and 122 may be sandwiching portions for fixing the respective end portions.

When the first end 2a and the second end 2b of the printing rubber blanket 1 are set on the fixing

portions

121 and 122, as shown in FIG. The fixed shaft 120b is rotated and adjusted by operating the grip portion so that it faces. In this state, one end (first end 2a) is first set between the fixed portion 121 and the fixed shaft base 125 that supports the fixed portion 121, and then between the two distal ends of the fixed portion 122. The other end (second end 2b) is set. Thereafter, the fixed shaft 120b is rotated around the shaft, and the tip of the fixed portion 122 is pressed against the side surface of the fixed portion 121 (FIG. 2C). The fixing part 121 also has a role as a holding part at the tip of the fixing part 122. When the front end of the fixing portion 122 is pressed against the side surface of the fixing portion 121, the printing rubber blanket 1 is wound inside the cylinder body 101 by the fixing shaft 120b. As a result, the printing rubber blanket 1 is fixed to the cylinder body 101.

The surface 4a of the plastic layer 4 opposite to the sheet-like substrate 2 is a rough surface having an arithmetic average roughness Ra of 2.0 μm to 20 μm, and the rough surface has a satin pattern.

The rubber blanket 1 for printing according to the embodiment can be used as a blanket for offset printing, for example, and is fixed to the blanket cylinder 100 by the procedure shown in FIG. At the time of use, the surface rubber layer 3 of the printing rubber blanket 1 receives ink from the plate cylinder and sends it to the printing medium, and the intended print image is transferred to the printing medium.

According to the printing rubber blanket 1 according to the embodiment described above, the printing rubber blanket 1 is wound around the blanket cylinder 100 and fixed as shown in FIG. The metal sheet-like base material 2 is not in direct contact with the peripheral surface of the blanket cylinder 100 during the wrapping attachment, and the plastic layer 4 on the back surface of the sheet-like base material 2 is interposed between the blanket cylinder 100 and the sheet-like base material 2. Is done. As a result, scratches on the metal sheet-like base material 2 and the blanket cylinder 100 due to the metal sheet-like base material 2 coming into direct contact with the blanket cylinder 100, the metal sheet-like base material 2 and The generation of rust due to the contact of different metals between the blanket cylinders 100 can be suppressed.

However, when the printing rubber blanket 1 is wound around and attached to the blanket cylinder 100, as described in the background art, if the plastic layer 4 directly contacts the blanket cylinder 100, the blanket metal sheet-like substrate 2 is brought into contact with the blanket cylinder 100. The coefficient of friction increases as compared with the case of direct contact with 100. As a result, the printing rubber blanket 1 cannot be mounted on the blanket cylinder 100 accurately.

According to the embodiment, the surface 4a opposite to the sheet-like substrate 2 of the plastic layer 4 is a rough surface having an arithmetic average roughness Ra of 2.0 μm to 20 μm, and the rough surface is a satin pattern. Therefore, the friction coefficient between the plastic layer 4 and the blanket cylinder 100 can be reduced when the rubber blanket 1 for printing is wound around and attached to the peripheral surface of the blanket cylinder 100. As a result, mounting of the printing rubber blanket 1 to the blanket cylinder is facilitated and handling is improved, so that the printing rubber blanket 1 can be accurately positioned on the blanket cylinder 100, and the printing rubber blanket 1 is displaced during use. Can be prevented.

Hereinafter, an example will be described in detail.

<Example 1>
A polyamide film having a width of 20 mm, a length of 200 mm, and a thickness of 0.10 mm was prepared as a plastic layer. The polyamide film was subjected to a sample without being roughened (Ra value 0.14 μm).

<Example 2>
A polyamide film having a width of 20 mm, a length of 200 mm, and a thickness of 0.10 mm was prepared as a plastic layer. The surface of this polyamide film was processed into an L-shaped dot shape to give a rough surface with an Ra value of 4.60 μm.

<Example 3>
A polyamide film having a width of 20 mm, a length of 200 mm, and a thickness of 0.10 mm was prepared as a plastic layer. The surface of this polyamide film was processed into a rhombus lattice shape to give a rough surface with an Ra value of 4.39 μm.

<Example 4>
A polyamide film having a width of 20 mm, a length of 200 mm, and a thickness of 0.10 mm was prepared as a plastic layer. The surface of this polyamide film was processed into a satin finish to give a rough surface with an Ra value of 3.66 μm.

<Example 5>
A polyamide film having a width of 20 mm, a length of 200 mm, and a thickness of 0.10 mm was prepared as a plastic layer. The surface of this polyamide film was processed into a satin shape to give a rough surface with an Ra value of 5.99 μm.

[Evaluation 1]
A cylinder made of stainless steel (SUS304) with a diameter of 38 mm, a weight of 0.5 kg, and Tensilon (model: RTC-1250A) manufactured by Orientec as a load cell were prepared. Subsequently, a weight is fixed to one end along the long side of the films of Examples 1 to 5, a load meter is fixed to the other end, and the film portion located between the weight and the load meter is suspended on the support shaft. did. Thereafter, the load meter was pulled downward at a speed of 5.0 mm / min, and the static friction force (N) was measured. This was done three times and the median was recorded.

The results of Evaluation 1 are shown in Table 1 below.

As is clear from Table 1, the film whose surface was roughened by processing with L-shaped dots and rhombus lattices (Examples 2 and 3) had a coefficient of friction as compared with the film of Example 1 without roughening. It can be seen that the static frictional force involved in is reduced.

Further, it can be seen that the film (Example 4, Example 5) having a roughened surface processed into a satin finish has a lower static frictional force than the films of Example 2 and Example 3.

[Evaluation 2]
In order to further confirm the effect of the present invention, printing rubber blankets each including the films of Examples 1 to 5 described above as a plastic layer were prepared, and the mounting properties when the printing rubber blanket was mounted on the blanket cylinder and The printability was evaluated.

First, the surface rubber layer 3 made of NBR was provided on the surface of the SUS sheet-like base material 2 shown in FIG. 1 so that the left end portion 2a of the sheet-like base material 2 was exposed. The total thickness including the surface rubber layer 3 is 1.75 mm.

<Example 6>
The film of Example 1 (thickness: 0.125 mm) is pasted to the back surface of the sheet-like substrate 2 opposite to the surface rubber layer 3 using an adhesive (0.035 mm), and printing with a thickness of 1.91 mm is performed. A rubber blanket was obtained.

<Example 7> to <Example 10>
The films of Examples 2 to 5 (thickness: 0.025 mm) were bonded to the back surface of the sheet-like substrate 2 opposite to the surface rubber layer 3 by using a double-sided adhesive tape (0.15 mm), respectively. A rubber blanket for printing of 1.925 mm was obtained.

As an evaluation of the wearability, the rubber blankets for printing in Examples 6 to 10 were each attached to a blanket cylinder to confirm the wearability. For example, the wearability of the wearer was sensory-evaluated in three stages, “1”, “2”, and “3” as shown below. That is, the friction force was reduced when 1 was installed. In No. 2, a relatively large frictional force was applied at the time of wearing. The frictional force of 3 was larger than the evaluation of 2.

Further, as an evaluation of printability, printing was performed on the entire surface of the reprint using the printing rubber blankets of Examples 6 to 10, and the printability was confirmed. The printability is, for example, whether ink is applied to the entire surface with a printing pressure of 0.15 mm so that the density is about 1.0 with respect to the refill paper, whether the uneven shape of the plastic layer is reflected on the printed surface, and white spots, etc. It was confirmed that there was no abnormality. The case where the print surface was reflected or abnormal was evaluated as “unsuitable”, and the case where it was not reflected on the print surface and there was no abnormality was evaluated as “good”.

The results of Evaluation 2 are shown in Table 2 below.

As apparent from Table 2, the printability was good in all the rubber blankets for printing in Examples 6 to 10.

The rubber blanket for printing (Examples 7 and 8) provided with a polyamide film having a rough surface by processing the surface of Example 2 and Example 3 with L-shaped dots and a rhombus lattice is the same as the polyamide film without the rough surface processing of Example 1. Compared with the printing rubber blanket (Example 6) provided, the frictional force when mounted on the blanket cylinder was reduced.

The rubber blankets for printing (Examples 9 and 10) having a polyamide film which was roughened by processing the surface of Example 4 and Example 5 into a textured surface were further mounted compared to the rubber blankets for printing of Examples 7 and 8. The frictional force was reduced.

Therefore, the rubber blankets for printing of Examples 9 and 10 can improve the handleability when mounted on the blanket cylinder.

Claims

Metal sheet-like substrate;
A surface rubber layer provided on the surface of the sheet-like substrate so that an end of the sheet-like substrate is exposed; and a plastic layer provided on the back surface of the sheet-like substrate opposite to the surface rubber layer The plastic layer is disposed opposite or substantially opposite the surface rubber layer with the sheet-like substrate interposed therebetween;
With
The surface of the plastic layer opposite to the sheet-like substrate is a rough surface having an arithmetic average roughness Ra of 2.0 μm to 20 μm,
The rough surface is a rubber blanket for printing having a satin pattern.
The plastic layer is made of polyamide, polyester, polypropylene, polyethylene, polyurethane, polyolefin, phenolic compound, nylon polyvinyl fluoride, polyvinyl chloride or a copolymer containing polyvinyl acetate, or ethylene-acrylic acid, ethylene-methacrylic acid copolymer. The printing rubber blanket according to claim 1, which is a united film.
The printing rubber blanket according to claim 1, wherein the plastic layer is a polyamide film.
The printing rubber blanket according to any one of claims 1 to 3, wherein the surface rubber layer is provided on the surface of the sheet-like base material with an adhesive layer interposed therebetween.
The printing rubber blanket according to any one of claims 1 to 3, wherein the surface rubber layer is provided by sandwiching one or more base fabric layers on the surface of the sheet-like base material.
The printing rubber blanket according to any one of claims 1 to 3, wherein the surface rubber layer is provided on the surface of the sheet-like substrate with one or more compression layers interposed therebetween.