JP3094647B2 - Photosensitive resin support structure for printing plate production - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel photosensitive resin support structure used for producing a printing plate from a liquid photosensitive resin or a solid photosensitive resin plate. More specifically, a photosensitive resin printing plate using the support structure of the present invention is directly adhered to a plate cylinder of a printing press, or is temporarily adhered to a support such as a carrier sheet and then to the plate cylinder. The present invention relates to a photosensitive resin support structure having an effect of enabling high working efficiency to be maintained without causing air pockets on an adhered surface when affixing to a plate cylinder side for mounting.

[0002]

2. Description of the Related Art It is well known to manufacture a printing plate from a solid or liquid photosensitive resin, and is basically performed through image exposure, development and post-processing steps (for example, Convertec). , March 1989, pp. 63-67). At this time, in order to ensure easy handling, mechanical strength, or dimensional accuracy of the obtained photosensitive resin plate, a support (base film) is laminated on the surface of the photosensitive resin layer opposite to the relief forming layer. ing. A cushion sheet or the like may be further laminated to ensure print quality.

The obtained printing plate is cut into a predetermined size and fixed directly to a plate cylinder of a printing press, or is temporarily fixed to a support table such as a carrier sheet or a saddle to form a printing plate after the plate is adjusted to a printing size. Attach to plate cylinder. At this time, as a method of fixing the printing plate to the plate cylinder side, a method of bonding or adhering the back surface of the printing plate support and the surface to be fixed on the plate cylinder side with a double-sided adhesive tape has been widely used.

[0004] In this method of sticking and fixing with a double-sided adhesive tape, it is possible to repeatedly bond and peel off by appropriately adjusting the adhesive strength, and to adjust the position when attaching the printing plate or use the printing plate repeatedly. It is convenient at the time. JP-A-61-61168 discloses that by providing an adhesive layer on the back of a printing plate support in advance, the plate can be quickly fixed to the plate cylinder side by a simple operation, and a special adhesive material such as a double-sided adhesive tape can be used. A method for producing a photocurable resin plate material that is not required is proposed.

However, when the double-sided adhesive tape is adhered to the back of the printing plate, or when the adhesive layer adhered to the back of the printing plate is adhered to the plate cylinder, air is trapped on the adhesive surface and bubbles are formed. In reality, considerable skill is required to attach the film without generating bubbles. Therefore, Japanese Utility Model Application Laid-Open No. 3-18148 discloses a double-sided adhesive tape in which adhesive surfaces are formed on both surfaces of a tape base material, by forming at least one surface of the adhesive layer as an intermittent adhesive layer so that air bubbles enter the adhesive surface. We have proposed a double-sided adhesive tape for fixing master paper for offset printing, which can be easily adhered without causing blemishes.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to produce a printing plate from a liquid or solid photosensitive resin and to attach the printing plate to the plate cylinder side via an adhesive layer. The same simple process as the conventional photosensitive resin printing plate can be adopted in the process, and the printing plate can be quickly and easily attached to the plate cylinder side without using a double-sided adhesive tape. Photosensitivity for printing plate manufacturing that makes it possible to easily perform the work without entrapping air bubbles in the bonding surface in the printing plate attaching work, and to make such printing plates inexpensive. It is to provide a resin support structure.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a support structure in which an adhesive layer and its protective film are provided on a support, which is opposite to the surface where the adhesive layer is in contact with the support. A photosensitive resin support structure for producing a printing plate, characterized in that the surface has a passage for communicating air which is open when the protective film is peeled off. This problem is solved by the present support structure. As shown in FIG. 1, the support structure of the present invention includes a support 1, an adhesive layer 2 having an open and communicating air passage, and a protective film 3.

The support 1 is for laminating the support on a photosensitive resin to reinforce the printing plate finally obtained and to keep the printing plate in a predetermined shape. It is appropriately selected depending on the situation. When back exposure or masking exposure is performed from the support side during the production of a printing plate, a plastic film or sheet transparent to actinic rays is used. Such examples include polyester films, polypropylene films, polyvinyl chloride films, and the like. The thickness of the plastic film support is usually in the range of 10 μm to 500 μm, but a polyester film having a thickness of 50 to 250 μm is often used in view of providing sufficient strength for supporting the resin plate and cost.

The adhesive layer 2 is for attaching the support 1 on which the resin printing plate is laminated to the plate cylinder side, and is arranged on the surface of the support opposite to the plate side. Known adhesives such as acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and vinyl acetate adhesives (advanced by Shozaburo Yamaguchi) "Encyclopedia of Adhesion and Adhesion," published by Asakura Shoten in 1986, 11
8 to 169) in consideration of the transparency to actinic rays, adhesive strength / adhesive strength / peeling strength with a support or a protective film, solvent resistance to a developing solution, and the like. For the purpose of the present invention, a removable pressure-sensitive adhesive that does not permanently adhere is preferable, and examples thereof include an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, and a silicon-based pressure-sensitive adhesive.

When the thickness of the adhesive layer 2 is too large, misregistration occurs and the printing accuracy is reduced. When the thickness is too small, the adhesion to the adherend is poor. ５００500 μm. On the surface of the adhesive layer 2 opposite to the surface in contact with the support, there is provided a passage for communicating air which is opened in a state where the protective film is peeled off, and the passage is formed of the adhesive layer. It is connected to the end. This is to prevent air from being trapped between the adhesive surface and the surface to be adhered on the plate cylinder side when the printing plate is adhered to the plate cylinder side.

The cross section of the air passage is rectangular, for example.
There are wedge-shaped and semi-circular shapes, the depth of which reaches the surface of the support or reaches halfway. The plane pattern of the air passage has to be continuous with the path, and for example, there is a pattern such as a stripe shape, a lattice shape, and a mesh shape.
Further, the structure having an open communicating passage of air is such that the adhesive is scattered vertically and horizontally, a porous body of the adhesive, a fibrous laminate of the adhesive, or a combination thereof. Is also good.

If the opening width of the air passage is too large, the influence of the step of the thickness of the adhesive layer is transmitted to the plate surface. If the opening width is too small, the passage is blocked by the cold flow of the adhesive. Is suitably within the range. The average distance between the roads is preferably in the range of 0.5 mm to 20 mm, because if the distance is too long, the formation of air bubbles is allowed between them, and if the distance is too short, the adhesion stability decreases. Note that a thin film layer may be provided in the adhesive layer for the purpose of reinforcement.

As for the method of providing the adhesive layer on the surface of the support, there are known methods such as a method of dissolving or dispersing the adhesive in a volatile solvent and coating the surface of the support, and a method of melt-coating the adhesive. The method is taken. A method of forming an adhesive layer having an open communicating passage of air is, for example, by applying a stripe of a desired size on the surface of the support or by once applying the adhesive to the entire surface of the support. Scraping the adhesive with a nail having the desired cross-sectional shape and pitch, or pressing the adhesive on the adhesive surface with a roll having the desired letterpress shape and pattern, or foaming and porousizing the adhesive with a foaming agent Or by extruding an adhesive into a fibrous form and laminating it on a support, or a combination thereof.

On the surface of the adhesive layer opposite to the surface in contact with the support, a protective film is provided to protect the adhesive layer during handling or in the process of plate making and plate attachment. The protective film preferably has resistance to a developing solution such as an aqueous, alcohol, or hydrocarbon used in the plate making process. Examples of such a protective film include a transparent plastic film made of polyester, polypropylene, polyethylene, propylene-ethylene copolymer, soft polyvinyl chloride, polyamide, and acrylic resin having a thickness of 5 to 200 μm. When back exposure is not required, an opaque material such as synthetic paper or waterproof paper can be used.

The adhesive strength of the adhesive layer is appropriately adjusted as needed. The adhesive strength with the support is 180 ° after the test piece having a width of 25 mm is left at 20 ° C. for one week to stabilize the adhesive strength. It is desirable that the adhesive strength (180 ° adhesive strength) when peeled at a speed of 300 mm / min in the direction of degree is 50 g / 25 mm or more, preferably 200 g / 25 mm or more. If the 180 ° adhesive strength is 200 g / 25 mm or more, even a thick plate having a plate thickness of 3 mm or more does not cause practical problems such as peeling.

The adhesive force of the adhesive to the carrier sheet or to-be-adhered surface on the plate cylinder side is the same as the adhesive force to the support. However, if the adhesive force to the support is smaller when the plate is once peeled off, the adhesive is It is not preferable because the layer accompanies the surface to be bonded on the side opposite to the support. In order to avoid this, a known adhesive is applied on the support side in advance to enhance the adhesiveness of the two, and an anchor coat layer is provided, or a measure is taken to increase the adhesive strength by directly corona-treating the support. .

[0017] Also, the adhesive force between the adhesive layer protective film, at lest and usually 180 ° adhesion from readily say points peeling of the protective film to peel the protective film during handling or during plate-making process 1 ~ 500g / 25mm, preferably 5-200g
/ 25 mm, more preferably 10 to 50 g / 25 mm. In addition, this adhesive force must be adjusted to be smaller than the adhesive force with the support described above in order to enable the peeling of the protective film. For this purpose, a release agent layer may be provided on the surface to be bonded of the protective film. As the release agent, a known release agent or a fluororesin which is generally used for an adhesive tape or the like is used.

[0018] The surface of the protective film opposite to the surface in contact with the adhesive layer is preferably uniformly roughened in order to improve the evacuation during plate making. Roughening does not need to be performed excessively, for example, 10-point average roughness (Rz) according to JIS standards
About 0.1 μm is sufficient. Examples of the method for roughening include a sand blast method and a chemical etching method. Further, when a film or sheet used for the protective film is formed, the film can be formed by a resin matting method for roughening the surface.

On the surface of the support on which the photosensitive resin is laminated,
A resin adhesive layer may be provided to enhance the adhesiveness with the resin. This adhesive layer is formed by applying an adhesive material to the support or directly corona-treating the support. As the adhesive material, those known as an adhesive for a support for a photosensitive resin plate, for example, those described in JP-B-48-6563 and JP-A-49-43561, the chemical properties of the photosensitive resin. It is appropriately selected in consideration of such factors. A dye or an ultraviolet absorber may be added to the adhesive layer for the purpose of preventing halation or adjusting the ultraviolet transmission wavelength range. The thickness of the adhesive layer is usually 0.1 to 10 μm
Is within the range.

The photosensitive resin for which the support structure of the present invention can be used is a known photosensitive resin which undergoes a radical reaction upon irradiation with actinic rays to polymerize and cure. As such a photosensitive resin, for example, a liquid photosensitive resin obtained by mixing an ethylenically unsaturated compound and a photopolymerization initiator with a prepolymer composed of unsaturated polyester or unsaturated polyurethane,
Alternatively, for example, a polymer selected from styrene butadiene copolymer rubber, styrene isoprene copolymer rubber, methyl methacrylate resin, partially saponified polyvinyl acetate, water-soluble polyamide, unsaturated polyurethane, etc. is used as a binder, and an ethylenically unsaturated compound, light There is a solid photosensitive resin plate to which a polymerization initiator is added.

In the support structure of the present invention, the developing solution may penetrate into the air passage provided in the adhesive layer during the developing step in the production of the printing plate. When the protective film is peeled off to attach the plate, the soaked developer emits an unpleasant odor, which is not desirable for environmental hygiene, or the performance may fluctuate by acting on the adhesive layer. The support structure of the present invention is more advantageously used for a liquid photosensitive resin which usually uses an aqueous developer.

In the support structure of the present invention, when it is necessary to perform back exposure and masking exposure during the production of a printing plate, all of the layers are required to have a thickness of 300 to 40 required for polymerization and curing of the photosensitive resin.
It is necessary that the support structure has a transmittance for actinic rays in a wavelength region of 0 nm, and the support structure has an actinic ray transmittance of 10 nm.
%, Preferably 30% or more.

The support structure of the present invention is used as a resin support in a step of manufacturing a printing plate from a photosensitive resin, and when the manufactured printing plate is attached and fixed to a surface to be adhered on the plate cylinder side, When the protective film is peeled off, the adhesive layer is exposed, and the adhesive layer is adhered to the plate cylinder-side adhered surface and is used for printing. When attaching this adhesive layer to the plate cylinder side, even if there is a part where air is trapped and air pockets do not stick, if this part is pressed lightly from the top of the printing plate, this air is easily released. It can be pasted and uniformly attached on the entire surface.

[0024]

The present invention will be described below with reference to examples.

Example 1 (1) Fabrication of Supporting Structure Thickness 1 coated with a vinyl chloride-based adhesive to which a photopolymerization initiator was added in order to increase adhesion to a photosensitive resin on one surface
00 μm transparent polyester film (APR plate making base film, Asahi Kasei Kogyo Co., Ltd., BF-
On the other side of the support (base film) made of 304), a 100-μm-thick pressure-sensitive acrylic double-sided adhesive tape (Scotch, trade name, manufactured by Sumitomo 3M Limited)
ST-416) was divided into a width of 6 mm, and was adhered in stripes at intervals of 1 mm to form an adhesive layer having an air passage communicating therewith. Next, a commercially available low-density polyethylene film having a thickness of 40 μm was laminated as a protective film on the adhesive layer to prepare a support structure of the present invention.

(2) Preparation of photosensitive resin printing plate Next, a photosensitive resin printing plate was prepared using this support structure. That is, prepare polyurethane prepolymer, ethylenic monomers, Asahi Chemical Industry as the liquid photosensitive resin comprising a photopolymerization initiator Co. photosensitive resin APR, F-47 (trade name), as the base film (1) The support structure thus obtained is used as a cover film to roughen one surface (Ra =
APR cover film CF-42 (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. consisting of a 30 μm thick polypropylene film having a thickness of 0.4 μm) and an anionic surfactant (APR Wash (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.)) as a cleaning liquid. Out agent type W-8) and 2% by weight of silicon-based antifoaming agent (APR antifoaming agent type SH manufactured by Asahi Kasei Corporation)
An APR ALF-III type (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. was used as a plate making apparatus for an aqueous solution in which -4) was dissolved in 0.2 wt%.

First, a negative film of a test pattern is placed on a glass plate of a plate making apparatus, a cover film is placed thereon so that the roughened surface is in contact with the negative film side, and a liquid photosensitive resin is placed on the negative film. The printing plate was supplied so as to obtain a 7 mm printing plate, the support structure prepared in (1) was placed on the resin so that the support side was in contact with the liquid resin, and the upper cover plate of the plate making machine was closed.

Subsequently, a flexographic printing plate having a thickness of 7 mm was prepared through the steps of relief exposure, back exposure, resin recovery, development with a washing solution, underwater exposure, and drying in accordance with the instruction manual. During the plate making step, no inconvenience caused by using the support structure of the present invention was particularly observed. The 180 ° peel strength of the adhesive layer of the printing plate at a tension speed of 300 mm / min is 180 g / 25 for the protective film.
mm, 500g / 25mm for polyester film
Met.

(3) Attaching and Printing of Printing Plate to Carrier Sheet The photosensitive resin printing plate prepared in (2) was then subjected to a printing step. Printing machine using a JEOL Seiki Co., Ltd. printing press Gem flex (trade name), was prepared kraft liner A flute double-sided cardboard as an object to be printed.

First, the protective film on the back surface of the printing plate was peeled off, but could be peeled off without difficulty. Next, the exposed adhesive layer was aligned and then stuck and fixed on a carrier sheet made of a polyester film having a thickness of 175 μm. At this time, even if air is partially left between the adhesive layer and the carrier sheet and air bubbles are generated, if the air is easily pressed by gently wiping the part from above the printing plate, the air easily escapes and the entire surface is stuck uniformly I was able to do it. The printing was carried out by mounting the carrier to the plate cylinder of the printing press, but no problem was found, and no inconvenience was caused by using the support structure of the present invention.

After the printing was completed, the carrier sheet was detached and the attached printing plate was peeled off by hand from the end, but could be easily peeled off. Then, the peeled printing plate was positioned and attached to another carrier sheet, but in this case, no air bubbles were trapped. Printing was performed with the carrier sheet attached to a printing machine, but printing was possible without any problem. All of the above operations could be performed by one person. When the printed matter was examined, no misalignment of the image due to plate elongation or misregistration was observed on the printed matter, and the printed matter was printed normally.

COMPARATIVE EXAMPLE 1 (1) Preparation of Support Structure In the preparation of the support structure of Example 1, when forming the adhesive layer, a pressure-sensitive acrylic double-sided adhesive tape was applied over the entire surface instead of a stripe. A support structure for the production of a photosensitive resin printing plate was prepared in the same manner except for sticking.

(2) Preparation of photosensitive resin printing plate Next, a photosensitive resin printing plate was prepared in the same manner as in Example 1.

(3) Attachment of printing plate to carrier sheet
As in the case of Printing Example 1, the protective film was peeled off and then applied to the carrier sheet. However, even if it was performed carefully, there was a part where air bubbles with an average diameter of 5 to 50 mm were entrapped between the adhesive layer and the carrier sheet and not adhered. Was. In order to release the air in this area, it was pressed with a strong wiping from above the printing plate, but the air did not escape. Peel off the printing plate from the carrier sheet to the part with air bubbles without stopping, paste it slowly and carefully again,
By repeating this process several times, we were able to finish the paste without trapping air bubbles.

The printing was carried out in the same manner as in Example 1 by mounting the carrier sheet on the plate cylinder of the printing press, but there was no particular problem at the time of printing or on the printed product. However, when the printing plate was peeled off from the carrier sheet after printing, and then pasted on another carrier sheet, the bubbles were again entrapped between the adhesive layer and the carrier sheet, making it difficult to paste it. It was the same as at the time. As exemplified above, when the plate attaching operation using the photosensitive resin printing plate support structure of the present invention is compared with the plate attaching operation using the support structure of Comparative Example 1, the present invention has It can be seen that the operation using the support structure is good.

[0036]

According to the support structure of the present invention, when a printing plate is manufactured from a photosensitive resin using the same, (1) an air passage is formed on the back surface through the same process as that of the conventional photosensitive resin printing plate. A printing plate having an adhesive layer provided with is obtained.

When this printing plate is attached to the carrier sheet or to-be-adhered surface of the plate cylinder via the adhesive layer, (2) the attaching operation is quick and easy without requiring a special adhesive material such as a double-sided tape. And (3) the operation can be performed easily and without skill, without air being entrapped in the bonding surface to generate air bubbles. Also, (4) a process of preparing a printing plate from a photosensitive resin and attaching it to a support base or a plate cylinder can be achieved at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a support structure of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support body 2 Adhesive layer 3 Protective film

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-288151 (JP, A) JP-A-2-146040 (JP, A) JP-A-63-213846 (JP, A) JP-A-2- 262659 (JP, A) JP-A-61-182043 (JP, A) JP-A-5-246012 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/00 G03F 7 / 09

Claims (1)

(57) [Claims] 1. A support structure comprising a support and an adhesive layer and a protective film provided on the support, wherein the adhesive layer has a protective film on a surface opposite to a surface in contact with the support. A photosensitive resin support structure for producing a printing plate, comprising a passage for communicating air that is open in a peeled state.