JPH039358A - Gravure pringing plate and production thereof - Google Patents

Abstract

PURPOSE:To simplify a plate making process and to reduce the cost of a plate making material and to eliminate the generation of pollution by an etching material and photosensitive material by forming a three-dimensional structure resin layer consisting of dike-shaped fine projecting parts and many recessed cell parts. CONSTITUTION:A photosensitive resin 6a is laminated on a supporting substrate 2. This photosensitive resin layer 6a is exposed through an image forming film 7 for forming the dike-shaped fine projecting parts formed to intersect with the light transmittable or light non-transmittable fine lines 7a and a positive or negative image film 8 of continuous gradation. the photosensitive layer 6a is formed with a latent image layer 4a for forming the dike-shaped fine projecting parts and a latent image layer 45a for forming the recessed cell parts and thereafter, the resin layer is developed and is thereby formed with the resin layer 6 of the three-dimensional structure consisting of the dike-shaped fine projecting parts 4 and the many recessed cell parts 5 of respectively different depths enclosed by these parts. the complication of the stages, the increased cost of the plate making and the generation of pollution by an aq. soln. used as a photosensitive agent are obviated in this way.

Description

Detailed Description of the Invention [Background of the Invention] <Industrial Application Field> The present invention relates to a gravure printing plate using a photosensitive resin and a method for producing the same.

<Conventional technology> Conventionally, gravure printing has been used for catalogs, picture postcards,
It is widely used for general paper printing, plastic printing, metal printing, etc., for printing calendars, posters, art reproductions, etc.

These gravure printing methods are mainly classified into two printing methods: halftone gravure type and conventional gravure type. However, in any of these methods, a photosensitive resin film is applied to the surface of a copper plate or copper cylinder, and then a master pattern is baked and developed by irradiating light I7, and then a copper corrosive solution is applied. A method of manufacturing a gravure printing plate by etching the copper plate to create a concave image on the copper plate has been adopted.

In other words, in the case of halftone gravure type, a positive film, in which the density of the image is made up of the size of halftone dots, is closely attached to a copper plate or copper cylinder coated with a corrosion-resistant photosensitive resin, and then exposed to light, especially ultraviolet light. After developing with a solvent or water, the copper plate or copper cylinder is etched with an aqueous iron perchloride solution to prepare a mesh gravure printing plate.

On the other hand, in the case of the conventional gravure type, a carbon tissue made photosensitive by adding dichromate (a photosensitive resin with gelatin as a supporting film) is closely attached to a copper plate or copper cylinder, and then a gravure screen (fine wire After printing a continuous photographic gradation positive film (screen for forming crossed cells) and then etching a copper plate or cylinder with an aqueous solution of iron perchloride, the difference in density of the printed positive image becomes This appears as a difference in depth due to corrosion, and this is used as a gravure printing plate.

<Problem to be solved by the invention> Gravure printing plates using such copper plates have been used for many years, but the process of manufacturing the printing plates is complicated and the plate making method is expensive. Therefore, in the recent era of high-mix, low-volume production, printing costs have become expensive, making it difficult for the demand for gravure printing to grow.

Further, there are many problems such as the fact that the dichromate used as a photosensitizer and the iron perchloride aqueous solution used as a corrosive solution cause pollution.

[Summary of the invention]

Summary> As a result of extensive research in view of the above problems, the present inventors have developed a gravure film in which a photosensitive resin is laminated 12 on a support substrate, and light-transmitting fine lines are crossed on this photosensitive resin layer. After forming bank-like fine convex portions by closely exposing a screen to light, a continuous tone positive image film is closely exposed to light again to form a latent image layer for forming concave portions,
By further developing, the continuous tone four-part forming latent image layer forms concave cell portions having different depths surrounded by bank-like fine convex portions. The present invention was completed based on the knowledge that when this fla layer is used as a gravure printing plate, the large number of concave cells having different depths can adjust the amount of gravure printing ink. This is what we have come to.

That is, the gravure printing plate of the present invention has a two-dimensional structure on a supporting substrate, which is composed of a bank-like fine convex part and a large number of concave cell parts each having a different depth and surrounded by the bank-like fine convex part. It is characterized by forming layers.

In addition, the method for producing a gravure printing plate of the present invention includes laminating a photosensitive resin on a support substrate 2, and forming this photosensitive resin layer by crossing light-transmitting or light-opaque fine lines. The photosensitive resin layer is exposed to light through an image film for forming fine convex portions and a continuous tone positive or negative image film to form a latent image layer for forming fine convex portions on the photosensitive resin layer and a latent image layer for forming concave cell portions. After forming the image layer, it is developed to form a three-dimensional structural resin layer consisting of bank-like fine convex portions and a number of concave cell portions each surrounded by the concave cell portions having different depths. This is the way to do it.

Effect> The gravure printing plate of the present invention can be used for gravure printing by simply attaching a continuous tone positive dip film or negative film to the surface of a photosensitive resin having a cell latent image, and developing it after exposure to ultraviolet rays. Since plates can be manufactured, the plate-making process can be simplified, the cost of plate-making materials can be reduced, and there is no pollution caused by etching materials or photosensitive materials, which solves various problems faced by conventional copper gravure printing plates. This makes it possible to stimulate demand for gravure printing in an era of high-mix, low-volume production.

In addition, in the case of conventional copper gravure printing plates, since the copper plate material is soft and easily scratched, it was necessary to apply chrome plating to prevent scratches from the stainless steel doctor used to scrape off excess ink from the plate surface. The photosensitive resin gravure printing plate is made of resin with a three-dimensional structure, and
Since silicone resin is uniformly applied to the entire surface of the plate-made resin, it is possible to form an extremely strong and scratch-resistant plate surface, and on top of that, the ink is coated with silicone resin that is easy to remove. Therefore, the ink can be easily scraped off without using a hard stainless steel doctor to scrape off the ink. Therefore, the ink in the non-image area of the container can be removed by simply rubbing it lightly using an elastic rubber or resin material as the doctor, so that the plate surface is not easily damaged. Additionally, excess ink can be easily wiped off using a wiping roller or paper roller instead of using a doctor.

The photosensitive resin gravure printing plate of the present invention has a thick non-image bank-like fine convex resin layer that exhibits appropriate elasticity, so compared to conventional metal gravure printing plates, it It has the advantage that ink can be easily transferred to.

[Detailed description of the invention]

N) Gravure printing plate The gravure printing plate 1 of the present invention, as shown in FIG. and surrounded by a large number of concave cell portions 5 each having a different depth.

(1) Support substrate (a) Material The support substrate 2 constituting the gravure printing plate 1 of the present invention is a film or sheet of plastic such as polyester resin, polyamide resin, polyimide resin, epoxy resin, ABS resin, PPO resin, etc. Rubber plates such as rubber, synthetic rubber, and natural rubber, metal plates such as aluminum, copper, and lead, JY paper, and wood blocks can be used, but plastic and metal plates are particularly suitable.

(b) Shape The optimum supporting substrate 2 is generally about 0.1 to 50 W, preferably about 0.2 to 0.5 W.

(e) Adhesive layer It is desirable that the support substrate 2 is provided with an adhesive layer 3 in order to improve the adhesion with the three-dimensionally structured resin layer 6 laminated thereon. For the adhesive layer 3, a material obtained by laminating a later-described photosensitive resin over the entire surface and photocuring it, an epoxy resin, or the like can be used.

In particular, the adhesive layer 3, which is made by impregnating the surface of the base material layer with a photosensitive resin layer and photocrosslinking and curing it, has good adhesion to the supporting substrate.
Moreover, it also has good adhesion to the three-dimensionally structured resin layer 6, making it suitable for Z).

(2) Three-dimensional structured resin layer (a) Shape The three-dimensional structured resin layer 6 constituting the gravure printing plate 1 of the present invention is generally 10 to 1000 μm thick on the surface of the supporting substrate.
The photosensitive resin layer 6 is laminated to have a thickness of approximately 40 to 100 μm, and the photosensitive resin layer 6 is exposed to light through an image film, followed by development 1.

As shown in the enlarged surface view of FIG. 1, the resin layer 6 having the three-dimensional structure has bank-like fine convex portions 4 formed in a lattice shape.
and a large number of concave cell portions 5 each having a different depth surrounded by the concave cell portion 5.

(b) Bank-like fine convex portion The bank-like fine convex portion 4 is made of a resin with a three-dimensional structure obtained by curing photosensitive resin, and in order to be used for gravure printing, the width of the bank is usually 20 to 60 μm2, preferably 30-4
At 0 μITI, the spacing between adjacent banks is usually 100-170
μm1 is preferably 120 to 150 μm, usually 2 to 1011IT+ for depth or highlight areas, and 4 for shadow areas.
0 = 80μ mouth 1, good [2, < is formed with 3 to 5 μrn' in the highlight part and 50 to 7011 m in the shadow part.

As the photosensitive resin forming the resin 6 having the above-mentioned diagonal structure, commonly used positive type or negative type water-soluble, alkali water-soluble, acid water-soluble, or organic solvent-soluble resins are used. It's coming. Among such photosensitive resins, the positive type is OF manufactured by Tokyo Ohka.
There are PR, etc., and the negative type is Toyobo Co., Ltd.'s Printite.

(e) Concave Cell Portion - A large number of concave cell portions 5 surrounded by the grasping fine convex portions 4 are formed to have different 7'J in order to store ink for gravure printing. The 'tQ lightness of the ink can be expressed by the amount of printing ink applied.

The width of the concave cell portion 5 is within the range surrounded by the bank-like fine convex portion 4, but since the amount of printing ink varies depending on the image, the depth of the concave cell portion 5 is varied to adjust the amount. are doing. Its depth is less than or equal to the height of the bank-like fine convex portion 4,
Normally, the highlight area is 2-10μm, and the shadow area is 30-μm.
80 μm1, preferably 3 to 5 μm for highlight areas and 30 to 40 μm for shadow areas.

[11] Manufacture of gravure printing plate (1) Manufacturing method The gravure printing plate of the present invention basically consists of laminating the positive or negative photosensitive resin on the supporting substrate, and forming the photosensitive resin layer. It can be produced by exposing it to light through a positive or negative image film and then developing it.

(a) Photosensitive Resin Depending on whether a positive type or negative type photosensitive resin is used as the above-mentioned photosensitive resin, there will be some differences in the manufacturing process.

Negative type> Specifically, when using a negative type photosensitive resin, light-transmitting fine lines as shown in Figure 3 are crossed.
A gravure screen made of a C-formed image film is brought into close contact with the photosensitive resin surface and exposed to light such as ultraviolet rays to form a latent image layer for forming bank-like minute convex portions. Next, a continuous tone positive image film is brought into close contact with the surface of the photosensitive resin and exposed to light such as ultraviolet rays. A latent image layer for forming concave cell portions is formed on a photosensitive resin, and the photosensitive resin layer is partially polymerized or crosslinked to form a resin having a three-dimensional structure.

Alternatively, after a continuous tone positive image film is brought into close contact with the photosensitive resin surface and exposed to light such as ultraviolet rays, the gravure screen is again brought into close contact with the photosensitive resin surface and exposed to light such as ultraviolet rays again, A latent image layer for forming concave cell portions is formed surrounded by a latent image layer for forming bank-like minute convex portions made of resin having a three-dimensional structure.

Alternatively, a continuous floor with the gravure screen;7. B1
Pre-synthesis of positive image films 1. A synthetic positive film is formed, and this film is densely deposited on the surface of a photosensitive resin, and by one exposure, a latent image layer for forming bank-like minute convexities made of resin with a three-dimensional structure is formed. It is also possible to form an island image layer for forming concave cell portions surrounded by it.

The photosensitive resin exposed in this way has a different degree of photocuring due to the difference in exposure amount, and cell images with different depths can be obtained depending on the development process. in fact,".

A solvent selected from an aqueous solution, an alkaline aqueous F4 liquid, an acid aqueous solution, an organic solvent, etc., which can dissolve and remove the unexposed photosensitive resin depending on the degree of photocuring is used.

Positive type> When using a positive type photosensitive resin, a light-opaque negative image film is used.

In such a negative image film 5, a negative film is used which is prepared by combining a continuous tone negative image film and a gravure screen formed by intersecting light-opaque fine lines as shown in Fig. 4. Alternatively, a negative laminate film can be used that simply overlaps the two.

For exposure, the above-mentioned d-transparent negative image film is brought into close contact with the photosensitive resin layer, and a latent image layer consisting of concave cell portions is formed by exposure at a certain degree.

Next, as the development process is carried out, the two-dimensional structured molecules that make up the cell image are decomposed by the light and become easily dissolved in the developer, and the whole is surrounded by bank-like fine protrusions. It is possible to form a large number of concave cell portions having different depths.

The solvent used for such dissolution and removal is a solvent selected from aqueous solutions, alkaline aqueous solutions, acid aqueous solutions, organic solvents, and the like.

The photosensitive resin that can be used in the present invention may be a photodegradable resin, a photocrosslinkable type, or a photopolymerizable type. A photopolymerizable printing plate is preferable.

(b) Exposure Light rays are irradiated to expose the above-mentioned photosensitive resin to make the resin photocurable by photopolymerization or photocrosslinking in the case of a negative type resin, and to make it soluble in a solvent by photolysis in the case of a positive type resin. and 1~, the wavelength is generally 360~
Light such as 400 μm ultraviolet light can be used.

(e) Development In the case of negative type photopolymerizable or photocrosslinkable photosensitive resins, the degree of polymerization or crosslinking of the resin molecules varies depending on the amount of irradiated light, and this causes a difference in the degree of polymerization or crosslinking of the resin molecules. It is thought that the solubility is different, and the difference in swelling property due to the difference in solubility appears as a difference in cell depth.

In addition, with positive photopolymerizable or photocrosslinkable photosensitive resins, the degree of polymerization and crosslinking of the photodegradable resin molecules varies depending on the amount of light irradiated, and this causes differences in solubility in the developer. It is thought that the difference in swelling properties due to the difference in solubility appears as a difference in cell depth.

Solvents used for such phenomena and 1. Examples include water, dilute aqueous hydrochloric acid solution, aqueous alkali solution such as 6-caustic soda solution, and organic solvent.

(2) Manufacturing process To more specifically explain the manufacturing of the gravure printing plate of the present invention, the manufacturing T culm when manufacturing using a negative type photosensitive resin will be explained below based on the drawings. .

(a) First, the support plate 2 is attached to the support plate 12, and then the support plate 2 is
A resin 1 (preferably 1.< is the same type of photosensitive resin used as the photosensitive layer) that will serve as an adhesive for the three-dimensional resin layer 6 is applied to the surface of the support plate 2 as shown in b). Exposure (in the case of a photosensitive resin, this is carried out to strengthen the adhesion to the support plate 2) 12 to form an adhesive layer]-3.

(1)) Next, as shown in FIG. 2(b), a negative type photosensitive resin layer 6a is formed on the surface thereof.

(c) Next, as shown in FIG. 2(c), a gravure screen 7 having transmissive cross lines 7a necessary for forming concave cells is closely printed and the photosensitive resin layer 6a is exposed to 1-τ light. A latent image 4a of a concave cell portion, which becomes a bank-like fine convex portion 4, is formed in the resin layer.

(d) Furthermore, if a photographic film 8 having a continuous tone positive image as shown in FIG. A latent image layer 5a for forming concave cell portions, which forms concave cell portions 5 with different photocured dust, is formed depending on the strength of the light. This is based on the principle that the reaction rate of the photosensitive resin 6a, which causes a photochemical reaction under the action of light, is proportional to the intensity of light, and the gradation of the positive film that has not been printed is the dark black part with high density. The light that acts on the resin is weak and the polymerization and crosslinking reactions of the resin do not proceed much.
By development, a large amount of the resin in the cells surrounded by the bank-like fine convex portions 4 is eluted, and deep concave cell portions 5 are formed. In addition, light passes through the light black areas with low density [7], and the photochemical reaction progresses sufficiently to cause little resin to be eluted from the cells during development, forming shallow concave cell areas.

Therefore, the unexposed photosensitive resin 6a in the latent image cell image 4a, which becomes the bank-like fine convex portions 4, is photocured, and a latent image image 5a, which becomes the concave cell portions 5 with different depths, is formed.

((N)) Then, as shown in Figure 2 (E), a water-soluble material is prepared according to the type of photosensitive resin 6a used by a developing method such as the streak 1 no method or the washing/sliding method. By developing with water, alkaline aqueous solution for water-soluble ones, acid aqueous solution for water-soluble ones, and organic solvent for organic solvent-soluble ones, concave cell image areas with different depths depending on the photocured dust can be developed. 5 is attracted, so silicone resin liquid 9 is applied to its surface.
The oil-repellent layer 9 is formed by applying the oil evenly to form a second layer.
1 in 1 for resin gravure printing as shown in the figure (f)
is obtained.

(III) Gravure printing The gravure printing plate manufactured in this manner is coated with ink such as conductive ink and resist ink, and the ink is filled deep into the concave cell portions.

Normally, it is not possible to apply just enough ink, so a doctor scrapes off the excess ink from the plate surface.

The concave cell part of the pattern image is formed from small concave cells of different depths surrounded by bank-like minute convex parts, and countless screen lines made of bank-like minute convex parts are formed on the printing plate. Gravure printing can be performed by scraping off excess ink with a doctor.

[Experiment example]

Example 1 A water-soluble photosensitive resin (Printite manufactured by Toyobo Co., Ltd.) 6a was applied with a roller to a thickness of 840 microns on the support substrate layer 2 made of a polyester film with a thickness of 240 microns, and then dried. The entire surface of this resin was exposed to light and photocured to form an adhesive layer 3 to strengthen the adhesion to the polyester film 2.

Next, a water-soluble photosensitive resin 6a of the same type as this water-soluble photosensitive resin 6a was applied to a thickness of 100 microns. A gravure screen 7 having 200 meshes of transparent intersecting lines 7a is closely attached to this photosensitive resin layer 6a and exposed to ultraviolet light from a distance of 1 meter using a 6KW mercury lamp for 1 minute to form a latent image 4a which becomes a bank-like fine convex portion 4. Then, a continuous-tone positive image photographic film 8 is closely attached, and the same light source is used for 1
A photosensitive resin layer 6a having a cell latent image 5a which becomes a positive concave cell portion 5 by exposure to ultraviolet light for one minute was obtained. These latent images 4a and 5a were developed with water using the streak 1 neutral method to create a photosensitive resin gravure printing plate 1, and then a silicone resin/&9 (Matsumoto Kogyo Seiyaku Orgatics S I Reinforce the plate by applying COO3) 1. Ta.

The cell depth of the obtained gravure printing plate was as follows.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged perspective view of a gravure printing plate according to an embodiment of the present invention, FIGS. 2(a) to (i) are manufacturing process diagrams, and FIG. FIG. 4 is an enlarged view of a gravure screen crossed with light-opaque fine lines; FIG. 1... Gravure printing plate, 2... Support substrate, 3...
Adhesive layer, 4... Bank-like fine convex portion, 4a... Bank-like fine convex portion latent image, 5... Concave cell portion, 5a... Concave cell portion latent image, 6... Tertiary Resin layer with original network structure, 6a.
... Photosensitive resin layer, 7... Gravure screen, 7a
...Lightly transparent intersecting lines. 8...Positive image film, 9...Oil repellent layer.

Claims (1)

[Claims] 1. A three-dimensional structured resin layer consisting of bank-like fine convex portions and a large number of concave cell portions each having a different depth surrounded by the bank-like fine convex portions is provided on a support substrate. A gravure printing plate characterized by the following: 2. Claim 1, wherein an oil repellent layer is formed on the three-dimensional structured resin layer.
Gravure printing plate described in . 3. An image film and continuous gradation for forming bank-like fine protrusions, in which a photosensitive resin is laminated on a support substrate, and this photosensitive resin layer is formed by intersecting light-transmitting or non-light-transmitting fine lines. exposure through positive or negative image film,
After forming a latent image layer for forming bank-like fine convex portions and a latent image layer for forming concave cell portions on the photosensitive resin layer, development is performed to form bank-like fine convex portions and the respective depths surrounded by them. 1. A method for producing a gravure printing plate, characterized in that a three-dimensional structural resin layer consisting of a large number of concave cells having different shapes is formed. 4. Layer negative photosensitive resin on the support substrate,
An image film for forming fine ridge-like protrusions formed by crossing light-transmitting fine lines is closely exposed to the surface of this photosensitive resin layer to form a latent image layer for forming fine ridge-like protrusions. After that, a continuous tone positive image film is brought into close contact with the surface of the photosensitive resin and exposed again to form a concave shape in the unexposed photosensitive resin surrounded by the latent image layer for forming fine ridge-like convexities. Claim 3: A latent image layer for forming cell portions is formed and then developed.
A method for producing a gravure printing plate as described in . 5. Layer negative photosensitive resin on the support substrate,
After a continuous tone positive image film is brought into close contact with the surface of this photosensitive resin layer and exposed to light to form a latent image layer, a bank-like fine convex portion formed by crossing light-transmitting fine lines is formed. 4. The method for producing a gravure printing plate according to claim 3, wherein the image film is brought into close contact with the photosensitive resin layer and exposed again to form a latent image layer, and then developed. 6. A positive photosensitive resin with a three-dimensional structure is laminated on a support substrate, and a continuous tone negative image film and light-opaque fine lines are formed in advance on the surface of the photosensitive resin layer to intersect with a continuous tone negative image film. 4. The method for producing a gravure printing plate according to claim 3, wherein a synthetic negative film formed by combining a negative image film and a gravure screen is exposed in close contact with each other and then developed. 7. Claim 3, wherein an oil repellent layer is applied on the three-dimensional structured resin layer.
7. The method for producing a gravure printing plate according to any one of items 6 to 6.