JPS60200249A - Photosensitive laminated body - Google Patents

Abstract

PURPOSE:To enhance intimate adhesion to an original at the time of exposure and to prevent tackiness of the surface of a printing plate by forming a photosensitive layer on a support and a cover film on this layer in succession, and interposing a layer contg. PVAL and a water-soluble cellulose deriv. between the cover film and the photosensitive layer. CONSTITUTION:A layer contg. (A) PVAL and (B) a water-soluble cellulose deriv. in a A/B weight ratio of 0.01-0.95 is interposed between the cover film and the photosensitive layer of a photosensitive laminated body composed of the cover film, the photosensitive layer, and the support from the upper layer. When the photosensitive laminate of such a structure is stripped of the cover film, the layers a and B are unifomly bonded to the photosensitive layer, and when it is brought into contact with a negative original and exposed, unfirom and intimate contact is ensured without tack, and a sharp image can be formed. After development, printing ink can be well transferred, and a good printing plate can be obtained. This photosensitive laminate can be used for decorative patterns, displays, photoresists, etc., in addition to various kinds of printing plates.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive laminate from which a printing plate with clear images and good ink transfer properties can be obtained. More specifically, in the present invention, during exposure, the v! ! This invention relates to a photosensitive laminate that has improved adhesion and also has improved adhesion on the plate surface after plate making.

Normally, when image-wise exposing a photosensitive resin plate, a method is used in which an original film is vacuum-adhered onto the photosensitive layer and exposed to actinic rays.

However, the surface of the photosensitive layer is often sticky, and due to this stickiness, when the original film is brought into close contact with the photosensitive layer, air is not partially removed and remains at the interface, resulting in the image being distorted. Uniform baking becomes impossible. Also, g
When the original film is later peeled off from the photosensitive layer, a part of the original film may be transferred to the surface of the photosensitive layer, and the surface of the photosensitive layer may be transferred to the original film, thereby damaging the original film.

In addition, photosensitive resin plates are available in a wide range of hardnesses, from those comparable to the hardness of metal to the softness of rubber, by selecting the photosensitive resin composition. You can get a relief version. Among these, in recent years, the demand for photosensitive resin plates for high-speed rotary printing in the business home printing field has increased, and as a result, the demand for relief plates having a soft hardness close to that of rubber has rapidly increased.

However, when the hardness of the relief plate surface becomes soft.

Coupled with this, the surface of the relief plate becomes sticky.

Several problems arise in its handling. For example, if the original film is placed on top of the relief plate after relief plate making, the gelatin layer of the original film will stick to it and may damage it. Further, during printing, foreign matter such as paper powder or thread waste adheres to the relief plate surface, hindering the transfer of printing ink, and causing staining of the printed pattern. Similarly, during printing, the fibers of the printing paper are peeled off. A so-called paper peeling phenomenon may be observed.

Various methods have been proposed to solve these problems. For example, one way to improve the adhesion between the original film and the photosensitive layer during exposure is to coat the surface of the #B photolayer with polyvinyl alcohol having a specified degree of polymerization, saponification, etc. 49803, JP-A-52-110010), and a method of providing an alcohol-soluble polyamide coating (JP-A-56-110941).

However, even if these could improve the adhesion between the original film and the photosensitive layer, they would be completely removed after development, drying, etc., that is, after plate making, and would not solve the problem of stickiness on the plate surface. .

On the other hand, as a method to prevent the stickiness of the plate surface after plate making, there is a method of hardening the surface layer of the relief plate surface, but for this purpose, it can also be called a post-processing method that adds another process after the relief plate making process. For example, chemical treatment with hypochlorous acid or short-wavelength ultraviolet irradiation is used. The disadvantage of this method is that the relief plate-making process takes a long time and requires reagents and equipment.

Another improvement method is to apply a small amount of an anti-blocking agent such as powder to the surface of the relief plate. Coating an anti-tack agent is a simple method, but its disadvantage is that the effect is only temporary, and depending on the amount applied, it can cause uneven printability, particularly ink transfer properties. Furthermore, such anti-blocking agents can impair the tackiness of the adhesive tape when the relief is mounted on the plate cylinder of a printing press.

Therefore, the present inventors have discovered that it is possible to improve the adhesion between the photosensitive layer and the original film when exposed to light, and to prevent the stickiness of the plate surface without adding any special process after plate making. As a result of intensive research efforts, we have finally completed the present invention.

That is, the present invention provides a photosensitive laminate comprising, at least from the upper layer, (1) a cover film, (2) a photosensitive layer, and (3) a support. :
(2) A photosensitive laminate characterized in that a layer containing (A) polyvinyl alcohol and (B) a water-soluble cellulose derivative is provided between the photosensitive layer and the photosensitive layer.

In the present invention, the photosensitive laminate is one in which an image can be obtained by exposing and developing an original film with actinic rays, and its composition includes at least slippers, a cover film, polyvinyl alcohol, and a water-soluble cellulose derivative. (hereinafter referred to as an anti-adhesive layer), a photosensitive layer, and a support.

A removable plastic film is used as the cover film, and in the present invention, a polyester film is most suitable.

Next, the components constituting the photosensitive layer are generally filled polymers,
It contains a photocuring agent, a photosensitizer, a polymerization inhibitor, and other additives, and depending on the type of filler polymer that is its main component, it is called, for example, polyamide-based, polyurethane-based, polyester-based, polyvinyl alcohol-based, etc. Either type can be employed in the present invention. I
The L photocuring agent is a compound containing one or more photopolymerizable unsaturated groups in 5 molecules, and known ones can be used, and examples of fc include the following. Ethylene glycol di(meth)acrylate.

Unsaturated compounds obtained by the addition reaction of trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycidyl (meth)acrylate with an active hydrocarbon compound (addition reaction of propylene glycol with glycidyl acrylate) ], N-substituted (meth)acrylamide, 2-hydroxyV ethyl (meth)acrylate, condensate of N-methylolacrylamide and polyhydric alcohol, etc.Other photosensitizers 1
Known polymerization inhibitors and the like can be used.

In the present invention, the photosensitive layer containing the above-mentioned components is developed with a solvent in which the photosensitive layer is emulsified, dispersed, or dissolved. In the present invention, a photosensitive layer that is developed with a solvent containing water as a main component is particularly preferred.

As the support constituting the present invention, any material such as metal such as steel and aluminum, plastic film, glass, etc. can be used.

In the present invention, the polyvinyl alcohol contained in the anti-adhesion layer provided between the cover film and the photosensitive layer is not limited in terms of degree of polymerization and degree of saponification.

Preferably the degree of polymerization is 500-3000. Saponification degree 80%
~100 rice cakes.

Examples of the water-soluble cellulose derivatives contained together with the polyvinyl alcohol include alkali metal salts or ammonium salts of carboxyl methyl cellulose, droxyethyl cellulose, hydroxypropyl cellulose, and methyl cellulose.

The mixing ratio of polyvinyl alcohol and water-soluble cellulose derivative is 0.01 to 0.95 in weight ratio of polyvinyl alcohol to the mixture. Since these coating layers are often exposed to light in close contact with the original film during plate making, it is desirable that the film strength be strong, and the less adhesion the better. In this respect, since water-soluble cellulose derivatives lack film strength and adhesive properties, it is preferable to increase the mixing ratio of polyvinyl alcohol, but the effect of preventing adhesion on the relief surface after plate making is better as the mixing ratio of polyvinyl alcohol is lower. There is. Therefore, the preferred weight ratio of polyvinyl alcohol to the mixture is 0.2 to 0.8.
In particular, 0.5 to 0.7 is optimal.

In the present invention, the anti-adhesive layer to be coated on the photosensitive layer is effective even if it is extremely thin; if it is thick, even if it has an anti-adhesive effect, the distance between the photosensitive layer and the original film becomes large, resulting in poor image reproduction. To avoid impairing fidelity, the layer thickness is usually 0.1 to 20 .mu.m, more preferably 0.1 to 5 .mu.m.

Any method can be adopted to obtain the photosensitive laminate of the present invention having the above-mentioned constituent requirements, but for example,
First, do you provide an adhesive layer on the support?

Alternatively, a photosensitive layer is provided as it is by, for example, a heat press method, a casting method, a solution casting method, a melt extrusion method, etc., and then polyvinyl alcohol and a water-soluble cellulose derivative are separately applied on a film to be used as a cover film for protecting the photosensitive layer. A method of applying an aqueous solution of the mixture of on the photosensitive layer.

A method in which the anti-adhesive RJj is formed by coating and drying, and a cover film is laminated thereon, and an anti-adhesive layer, which has been separately formed as a film, is laminated on the photosensitive layer.

Furthermore, there is a method of laminating a cover film.

When the cover film of the photosensitive laminate of the present invention obtained in this manner is peeled off, the surface of the coating film that is in close contact with the photosensitive layer side is non-tacky, so it can be uniformly adhered to the photosensitive layer side, resulting in a sharp image. Exposure becomes possible. Moreover, surprisingly, after development, the transferability of the printing ink is good, and a good printing plate can be obtained without foreign matter such as paper powder adhering to the plate surface during printing. The resulting printing plates include photosensitive resin letterpress materials, lithographic materials, and V5 printing materials.

In addition to the printing plate, the photosensitive laminate of the present invention also includes decorative designs,
It can be effectively used for various purposes such as name plates, displays, and other photoresists.

The present invention will be explained in more detail below using Examples and Comparative Examples.

Example 1゜1-cabroctam 47.5 kf, bisaminoprobil biverazine-azibe) 40.0 kf, nylon 6
6 Salt 12.5 ~ and water 100kF were placed in a 500I autoclave and heated at 180℃ for 2 hours, then the temperature was raised to 2.
Polyamide was produced by feeding at 40° C. for 4 hours. This polyamide has a ηrel (1ts in 96SVt acid solution at 30°C)
solution) was 2.4. 55 parts of this polyamide, 4.8 parts of adipic acid, 31.4 parts of acrylic acid reaction product of tripropylene glycol diglycidyl ether, 7.5 parts of N-methyltoluenesulfonic acid amide, 1 part of benzoin methyl ether/I, hydroquinone 10.3 parts of monomethyl ether/L was heated and dissolved in 100 parts of methanol.

This solution? 71ff (F-), methanol was removed by air drying in a dark place, and the mixture was further dried under reduced pressure at 30° C. for 16 hours. The sheet of uniformly transparent photosensitive resin composition thus obtained was thermally bonded to a 188μ thick polyester film via a polyester adhesive to form a photosensitive film having a 600μ thick photosensitive layer. Created.

On the other hand, in 75 parts of water, 3.5 parts of polyvinyl alcohol/I/ (PVA-420, manufactured by Kuraray Co., Ltd.) and sodium carboxymethyl cellulose (Celogen 7 A, manufactured by Daiichi Kogyo M-Yakusha) were added.
) 1.5 parts were dissolved and 20 parts of ethanol/I was added to obtain a clear homogeneous solution. This solution was coated on a 125μ polyester film using a roll coater, and dried with hot air at 90°C to form a thin film layer with an average thickness of 165μ. A photosensitive laminate having a cover film was prepared by thermocompression bonding at 95° C. with the sodium salt mixture coating facing the photosensitive layer side.

Next, when the obtained photosensitive laminate was brought into close contact with a negative film and exposed to N light, the cover film was peeled off.

The coating applied to the cover film was completely transferred onto the photosensitive layer, and the coating surface had no tackiness, allowing uniform adhesion of the negative film. After exposure.

It was developed in a Type 172 washing machine containing tap water and dried to obtain a relief plate. This relief plate had good image reproducibility with respect to negative film. When a polyester film was placed on the surface of the t7IC relief and pressed, both sides did not adhere at all and were easily peeled off, indicating that the relief surface had no tackiness.

Furthermore, using the obtained relief plate, the printing speed was increased to 80
When I printed 2,000 copies of A-49 size printed matter with 1 m, the ink was evenly transferred to all of them.

There was no adhesion of paper dust, etc., and the density of the peta portion was as high as 0.95 as a result of absorbance measurement (OD meter).

Comparative Example 1 A polyester film with a JiE of 125μ and a polymerization degree of 80
0, polyvinyl alcohol with saponification degree of 98.5%/L1
5ts aqueous solution was applied and dried to create a cover film having a polyvinyl alcohol film with a film thickness of 2μ, which was similarly thermocompressed onto the photosensitive film obtained in Example 1.
A li&photosensitive laminate was created.

The obtained photosensitive laminate was capable of uniformly adhering a negative film, but when a polyester film was placed on the surface of the relief plate obtained in the same manner as in Example 1 and pressure-bonded, the surface of the relief plate showed tackiness. However, an extremely large amount of force was required to peel off the polyester film.

Further, when the relief plate was subjected to a printing test in the same manner as in Example 1, there were an average of 20 spots out of 1074 solid areas where ink did not adhere due to fiber waste and paper dust. The concentration of the Mayupeta part was 0.86, which was about 10% lower than that of Example 1.

Example 2 Polyvinyl alcohol/L/(Nippon Gohsei Co., Ltd., Goseno/
A solution was prepared by dissolving 3.5 parts of L/NH-18) and 1.5 parts of methyl cellulose (Methyl Cellulose 400, manufactured by Hanui Chemical Co., Ltd.) in 75 parts of water, and then adding 20 parts of ethanol. A thin W4M film with a thickness of 1.5 μm was formed on a 125 μm polyester film using the same method as in Example 1.
A cover film with an anti-adhesion layer was obtained. This cover film was thermocompressed onto the photosensitive film obtained in □ in the same manner as in Example 1 to create a photosensitive laminate, which was exposed to light, developed, and dried to perform plate making to obtain a relief plate for printing. Ta. Since the obtained relief plate had no adhesive properties, it could be easily peeled off even when a negative film was pressed onto the surface of the relief plate. Next, I did a printing test using this relief plate and found out! You can get good quality prints.

Comparative Example 2 A 5.0% aqueous solution of boxymethylcellulose sodium salt was applied to a 125 μm thick polyester film.
After drying, a cover film with a carboxy V methyl cellulose film having a thickness of 2 μm was prepared.

A photosensitive laminate was prepared by thermocompression bonding on the photosensitive film obtained in Example 1 in the same manner.

The obtained photosensitive laminate had no tackiness on the surface from which only the polyester film serving as the cover film was removed, as in Comparative Example 1.

The surface of the relief plate obtained by imagewise exposure and development of the photosensitive laminate was sticky.

ti, when a printing test was conducted in the same manner as in Example 1,
There were an average of 15 spots where ink did not adhere to the 10cIa peta area, and the density in the peta area was low at 0.85◎ Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] 1. At least from the upper layer: (1) a cover film. In a photosensitive laminate consisting of (2) a photosensitive layer and (3) a support, between (1) the cover film and (2) the photosensitive layer, (A) HoIJI'ylalco-μ and (B) A photosensitive laminate comprising a layer containing a water-soluble cellulose derivative. 2. Mixing ratio of (A) polyvinyl alcohol and (B) water-soluble cellulose derivative [(A) / (A) + CB
)) is 0.01 to 0.95 (weight ratio), the photosensitive laminate according to claim 1.