JP2001209169A - Photosensitive resin printing plate material for forming peelable image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin printing plate material for forming a peelable image excellent in suitability to sharp cutting. SOLUTION: The dynamic hardness of the surface of the photosensitive resin of the photosensitive resin printing plate material measured with a microhardness tester DUH201 is 0.02-0.04.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin plate material for exposing and curing the surface of a photosensitive resin, making a cut with a cutter or the like, and peeling off unnecessary portions to form an image. More specifically, the present invention relates to a photosensitive resin plate material for forming a peeled image having excellent sharp cutting properties.

[0002]

2. Description of the Related Art Usually, a printing plate used for flexographic printing uses a photosensitive resin plate material or a rubber plate material such as natural rubber or synthetic rubber. As a plate-making method for preparing a printing plate using these plate materials, in the case of a photosensitive resin plate material, the plate surface of the photosensitive resin layer is vacuum-adhered to the plate surface of a negative or positive film using an original film, and actinic rays are irradiated. After irradiating and exposing and curing a part of the photosensitive resin layer, the original film was peeled off,
Generally, a printing plate is prepared by developing and removing unexposed and uncured portions. On the other hand, plate making methods using rubber plate materials have traditionally been made by hand engraving (hand-cut method) or casting method (moulding method). A plate making method is performed in which an input / instruction is performed, a rubber plate material is patterned by cutting with an automatic cutter or the like, and an unnecessary portion is peeled off to form an image.

[0003] The shape of the cutter used for this cutting is various, for example, for polymer cutting, bucket,
Film cutting and the like are mainly used and are selectively used depending on the image pattern.

There is no problem in image patterning with a cutter or the like using the above rubber material. The printing plate on which an image is formed is rich in rubber elasticity and has good printability and good printability. Since there is no adhesive layer between the rubber layer and the body (also referred to as a base film), there is a problem that the rubber layer peels off during long-time printing.

Therefore, in the case of plate making using a photosensitive resin plate material instead of the above, the above problem does not occur because the adhesive layer exists between the photosensitive resin layer and the support. The surface layer cannot be cut sharply when the resin surface is exposed, cured, cut with a cutter or the like, and cut and patterned.
Alternatively, it is difficult, and a printing plate on which a peeled image is formed has a problem that a clear image is hardly obtained, and there is a problem that a satisfactory printed matter is not obtained because of poor image reproducibility.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a plate-making method for forming a peeled image by exposing and curing the surface of a photosensitive resin layer, and then cutting off an unnecessary portion by cutting with a cutter or the like. An object of the present invention is to obtain a photosensitive resin plate material which is capable of sharp cutting and which has excellent ink runnability, printability and image reproducibility.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have intensively studied, studied, and studied a photosensitive resin plate material for forming a peeled image. The inventors have found that the above-mentioned problems can be solved in a photosensitive resin plate material in which the fine hardness of the photosensitive resin surface formed by the amount and curing is within a specific range, and finally completed the present invention. That is, the present invention is a photosensitive resin plate material for peeling image formation, wherein the dynamic hardness of the photosensitive resin surface measured by a micro hardness meter DUH201 is 0.02 to 0.04. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the dynamic hardness in the present invention is measured by Shimadzu Dynamic Ultra-Micro Hardness Tester DUH-201.
Is a value measured by the following equation under the following measurement conditions under an environment of room temperature and humidity of 68 to 72%. Test mode: Soft material test (MODE3) Indenter: Triangular pan indenter 115 ° Test load: 0.2 Igf Loading speed: 10 (0.0145 gf / sec) Holding time: 5 seconds Displacement full scale: 10 μm , Exposure machine illumination 95
Irradiation was performed on the photosensitive resin surface layer at １０５105 W / m ² for 30 seconds to 3 minutes to cure the surface. This irradiation time substantially corresponds to the irradiation amount necessary for curing the photosensitive resin layer, cutting with a cutter, and peeling off.

The dynamic hardness (DH) is a hardness obtained from a load in the process of pushing the indenter and a pushing depth, and is defined by the following equation. DH = αP / D ² α: Constant depending on indenter shape 115 ° In case of triangular cone indenter 37.838 P: Test load (gf) D: Depth of penetration (μm)

What is important in the present invention is that the value of the dynamic hardness measured under the above conditions is a value at the irradiation exposure time when the sharpness of cutting and the peeling property of the photosensitive resin layer are satisfied. , Dynamic hardness 0.02
It must be within the range of 0.04. 0.02
If it is less than 3, the photocurable property of the photosensitive resin layer due to the irradiation of ultraviolet rays is substantially poor, so that adhesiveness remains on the side surface of the photosensitive resin when cutting with a cutter or the like, and the cutting sharpness is poor. On the other hand, if it exceeds 0.04, although the photosensitive resin side surface has no tackiness, a saw-like waveform is generated on the cutting surface, resulting in poor cutting sharpness, and as a result, a problem of impairing image formation occurs. .

Particularly, the solvent-developing type photosensitive resin plate material conventionally used is excellent in photocurability by irradiation with ultraviolet rays because the layer structure of the photosensitive resin is a uniform composition system and excellent in light transmittance. (High crosslink density)
Even with short-time irradiation for 30 seconds, the dynamic hardness shows a large value of 0.04 or more, and as a result, there is a problem that a sawtooth waveform is generated on the cutting surface. Therefore, it is not preferable to take measures such as lowering the crosslink density because problems such as an increase in the adhesiveness of the photosensitive resin side surface occur.

The photosensitive resin plate material used in the present invention comprises a photosensitive resin composition which satisfies dynamic hardness, has sharpness of cutting, and easily peels off the photosensitive resin, and is particularly used for flexographic printing. Is used for printing applications such as aqueous inks, alcohol inks, and co-solvent inks, and is particularly preferable for printing applications using aqueous inks. In order to improve the affinity with the ink, at least the following formula ( a), (b), (c),
(D) a photosensitive resin composition containing a hydrophilic component containing at least one ionic hydrophilic group represented by (e), further comprising a photopolymerizable unsaturated monomer (crosslinking agent), It is preferable to use a light-sensitive plate material in which an agent and others are blended. (A) -COOM (b) -SO 3 M (c) -SO 4 M (d) -nPO (OM) n (e) (O) 3 -nPO (OM) n (M is a hydrogen atom, a periodic table Represents an element of group I, II, or III, an amine or an ammonium group, and n is 1 or 2.)

The hydrophilic component of the photosensitive resin composition used in the present invention may be a resin obtained by modifying a hydrophobic polymer with an ionic hydrophilic group in order to impart hydrophilicity to the hydrophobic component. A mixture of a hydrophilic component or a water-swellable component mainly containing a hydrophobic component containing a polymer and a hydrophilic or water-swellable polymer containing an ionic hydrophilic group as a main component, a hydrophobic polymer and an ionic hydrophilic compound Chemically bonded hydrophilic or water-swellable polymer containing groups, hydrophobic copolymer as raw material for hydrophobic polymer and hydrophilic monomer as hydrophilic polymer as block copolymer A preferred example is a type in which the hydrophilic component and the hydrophobic component are combined to form a photosensitive flexographic printing plate material.

Examples of the hydrophobic polymer mentioned here include 1,4-polybutadiene, 1,2-polybutadiene, acrylonitrile rubber, butadiene acrylonitrile rubber, chloroprene rubber, polyurethane rubber, butadiene styrene copolymer, styrene butadiene-styrene block copolymer. , Styrene-isoprene-styrene block copolymer, polyamide resin, unsaturated polyester resin, (meth) acrylic acid copolymer, butadiene- (meth) acrylic acid-acrylic ester copolymer, silicone rubber, polyoxypropylene glycol,
Polymers that give rubber elasticity to plates such as isoprene rubber, butadiene rubber, styrene butadiene rubber, butyl rubber, ethylene-propylene rubber, epichlorohydrin rubber, etc., acrylic resins and polyurethane resins that give hardness and stability, polyester resins, chlorinated polyethylene , Polypropylene, polyethylene, polyacryl nitrile,
Polymers such as polyvinyl chloride can be exemplified, and these can be used alone or in combination as necessary. The resins can be modified so that they can react with a monomer or a cross-linking agent or between polymers.

The hydrophilic or water-swellable polymer used in the present invention includes, for example, a polymer of (meth) acrylic acid or a salt thereof, and a polymer of (meth) acrylic acid or a salt thereof.
Alkyl (meth) acrylate and copolymer, (meth) acrylic acid or salts thereof-styrene copolymer, (meth) acrylic acid or salts thereof-vinyl acetate copolymer, (meth) acrylic acid or salts thereof-acrylonitrile weight Coalescence, -COOM group, -SO ₃ M group, -SO ₄ group, -nPO
Polyamides, polyvinyl compounds, polyurethanes, polyureaurethanes, polyesters, epoxy compounds, polyamides, and salts and derivatives thereof containing (OM) n or (O) _3- nPO (OM) n (n is 1 or 2) groups (Where M is the periodic table I, II, III
Group element, amine or ammonia group). Similarly, a plurality of hydrophilic components can be used in combination, and may be modified as necessary.

As the photosensitive resin composition, a crosslinking agent, an antioxidant, a polymerization inhibitor, a plasticizer, and the like are arbitrarily added to the polymer in addition to the polymer. Specific examples of the crosslinking agent include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate,
1,4-butanediol di (meth) acrylate, 1,
6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol (PEG # 200) di (meth) acrylate with a molecular weight of 200 ,
PEG # 400 di (meth) acrylate, 1,3-butanediol dimethacrylate, neopentyl glycol di (meth) acrylate, 1,10-decanediol dimethacrylate, ethylene oxide-free di (meth) acrylate of bisphenol A, Ethylene oxide-modified trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 1,9-nonanediol di (meth) acrylate, light ester P2M (Kyoeisha Chemical Co., Ltd.)
Acrylate), triacrylate of 3-mol ethylene oxide adduct of pentaerythritol, oligopropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, and the like. Particularly, alkylene glycol-based and alkylene ether-based crosslinking agents Is preferred.

In the method for producing the photosensitive resin plate material of the present invention, the raw materials of the photosensitive resin composition such as the polymer, crosslinking agent, antioxidant, polymerization inhibitor and plasticizer are mixed by a kneader or an extruder. A photosensitive resin is manufactured by kneading, and further sandwiched between a support film coated with an adhesive layer on a base film and a cover film coated with an anti-adhesive layer, with the photosensitive resin layer being the center, and hot pressing,
A photosensitive resin plate material can be obtained by sequentially laminating by a method such as calender molding.

As a plate-making method for forming a peeled image using the photosensitive resin plate material of the present invention, for example, a cover film having an anti-adhesion layer of the photosensitive resin plate material is peeled off, and then the surface of the photosensitive layer is irradiated with active rays. Then, the surface of the photosensitive resin layer is exposed and cured. The light irradiation time at this time is between 45 seconds and 3 minutes, preferably between 1 minute and 2 minutes. As actinic rays, 15
The composition is cured by irradiation with ultraviolet light having a wavelength of 0 to 500 nm, particularly 300 to 400 nm. As the light source,
Low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, zirconium lamps, carbon arc lamps, fluorescent lamps for ultraviolet light, and the like can be used.

Next, in order to form an arbitrary image, the photosensitive resin layer is cut into an arbitrary image pattern with a cutting cutter, particularly preferably a polymer cutter. Then, an unnecessary portion is removed by hand to form an image as a printing plate. At this time, the adhesive strength between the base film of the support and the photosensitive layer is 100 g / inch to 700 g / inc.
h, preferably the photosensitive resin layer can be easily peeled off by adjusting the irradiation of the actinic ray so that the adhesive strength becomes 150 to 400 g / inch. Adhesive strength is 10
In the case of irradiation to obtain 0 g / inch or less (irradiation time of 30 seconds or less), the sharpness of image formation by cutting and the occurrence of tackiness are not preferable, and 700 g / in.
In the case of irradiation for obtaining ch or more (irradiation time of 3 minutes or more), the adhesive layer and the photosensitive resin layer are firmly adhered to each other and cannot be peeled off, which is not preferable.

The image thus obtained is completely cured by the irradiation above the irradiation when the unnecessary photosensitive resin layer is peeled off. This complete curing irradiation may be either irradiation to the surface of the photosensitive layer and / or irradiation from the base film as necessary. By doing so, the adhesive strength is further improved and the image can withstand long-term printing. Is preferable. On the other hand, the anti-adhesion layer on the photosensitive resin layer is removed by peeling off unnecessary portions or by washing with water after completely curing the photosensitive resin layer, and further removing the anti-adhesion layer and drying. If it has adhesiveness later, it may be treated with a germicidal lamp.

Examples of the adhesive layer having the above-mentioned adhesive strength include, for example, JP-A-60-260948 and JP-A-6-260948.
An adhesive layer disclosed in, for example, JP-A-67426, specifically contains a copolymer polyester having a glass transition temperature of 10 ° C or lower by 90 to 50% by weight and a copolymer polyester having a glass transition temperature of 50 ° C or higher by 10 to 10%. An adhesive layer comprising a composition containing a mixture containing 50% by weight, a polyfunctional isocyanate, and a compound having a hydroxyl group and an acryloyl group or a methacryloyl group is exemplified.

As the base film used for the photosensitive resin plate material of the present invention, a polyethylene terephthalate film is preferable from the viewpoint of dimensional stability, heat resistance, mechanical properties, and the like. A plastic resin film such as a film, a polypropylene film, and a polystyrene film can also be used.

The anti-adhesion layer used in the present invention includes
Water-soluble polymers can be preferably used, and specific examples thereof include polyvinyl alcohol and derivatives thereof, celluloses, water-soluble butyral, and copolymers of compounds having a hydroxyl group in the molecule.

[0024]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 Using a 1.70 mm thick water-based photosensitive resin original plate (Cosmolite CLH manufactured by Toyobo Co., Ltd., adhesive layer polyester), the cover film of the photosensitive resin layer was peeled off to have an anti-adhesion layer. The photosensitive resin layer was exposed. next,
The photosensitive resin surface was irradiated for 45 seconds using an exposure machine (manufactured by A & V) having a lamp (manufactured by Philips) having an illuminance of 95 to 105 w / m ² . The dynamic hardness at this time was 0.02. The adhesive strength is 350 g / in
ch. Then, the unnecessary photosensitive resin layer was stripped off by cutting using a polymer cutter to form an image pattern. The cut surface was sharp, had no tackiness, and the work of peeling off the photosensitive resin layer was easy. 7 minutes on the photosensitive resin surface where the image was formed, 10 minutes from the base film
Exposure was performed for 2 seconds to completely cure. Next, the anti-adhesion layer on the photosensitive layer was removed by washing with water, dried and then treated with a germicidal lamp to obtain a printing plate. When this printing plate was used to print on coated paper using a water-based ink with a model printing machine, the ink was applied well, and printing was possible without peeling of the photosensitive layer during printing.

Example 2 An image was formed in the same manner as in Example 1, except that the exposure time to the photosensitive resin layer was changed to 60 seconds. At that time, the dynamic hardness was 0.02, and the adhesive strength was 300 g / in.
In ch, the photosensitive resin layer could be easily peeled off as in Example 1, and the cut surface was sharp and free of adhesion. Further, when printing was performed using a completely cured printing plate, the ink was applied well and there was no peeling during printing.

Example 3 An image was formed in the same manner as in Example 1, except that the exposure time to the photosensitive resin layer was 90 seconds. At that time, the dynamic hardness was 0.025, and the adhesive strength was 230 g / i.
As in Example 1, the photosensitive resin layer could be easily peeled off at nch, and the cut surface was sharp and free of adhesion. Further, when printing was performed using a completely cured printing plate, the ink was applied well and there was no peeling during printing.

Example 4 An image was formed in the same manner as in Example 1, except that the exposure time to the photosensitive resin layer was 120 seconds. At that time, the dynamic hardness was 0.028, and the adhesive strength was 145 g /
As in Example 1, the photosensitive resin layer could be easily peeled off, and the cut surface was sharp and free of adhesion. Further, when printing was performed using a completely cured printing plate, the ink was applied well and there was no peeling during printing.

Example 5 An image was formed in the same manner as in Example 1, except that the exposure time to the photosensitive resin layer was changed to 180 seconds. At that time, the dynamic hardness was 0.034 and the adhesive strength was 113 g /
As in Example 1, the photosensitive resin layer could be easily peeled off, and the cut surface was sharp and free of adhesion. Further, when printing was performed using a completely cured printing plate, the ink was applied well and there was no peeling during printing.

Comparative Example 1 A printing plate was prepared by cutting a rubber plate material (technoplast, Technolac) having a thickness of 1.14 mm to form a printing plate. The cut surface was sharp and had no tack. When printing was performed using this printing plate in the same manner as in Example 1, the ink application was good, but printing was performed for a while, and the printing was interrupted because the rubber plate material was peeled off from the base film during printing.

Comparative Example 2 The photosensitive resin layer surface was exposed for 30 seconds to the surface of the photosensitive resin layer in the same manner as in Example 1 using a solvent-developing type photosensitive resin original plate (manufactured by DuPont, HLS) having a thickness of 1.70 mm. The height was 0.061. However, when cutting was performed by cutting with a cutter, a saw-like waveform was generated on the surface of the photosensitive resin, and further, the photosensitive resin layer in an unnecessary portion was to be peeled, but the plate making was stopped because the photosensitive resin layer was not peeled. It was 500 g / inch when the adhesive strength was measured by peeling it off forcibly.

COMPARATIVE EXAMPLE 3 A photosensitive resin layer surface was exposed for 60 seconds to the photosensitive resin layer surface in the same manner as in Example 4 using a solvent-developing type photosensitive resin original plate (manufactured by DuPont, HLS) having a thickness of 1.70 mm. The height was 0.069. However, when cutting was performed by cutting with a cutter, a saw-like waveform was generated on the surface of the photosensitive resin, and further, the photosensitive resin layer in an unnecessary portion was to be peeled, but the plate making was stopped because the photosensitive resin layer was not peeled. When peeled off forcibly and the adhesive strength was measured, it was 600 g / inch.

COMPARATIVE EXAMPLE 4 Using a solvent-developing photosensitive resin original plate (manufactured by DuPont, HLS) having a thickness of 1.70 mm, the photosensitive resin layer surface was exposed to the photosensitive resin layer surface for 90 seconds in the same manner as in Example 4 using a dynamic hardening method. The height was 0.069. However, when cutting was performed by cutting with a cutter, a saw-like waveform was generated on the surface of the photosensitive resin, and further, the photosensitive resin layer in an unnecessary portion was to be peeled, but the plate making was stopped because the photosensitive resin layer was not peeled. It was 650 g / inch when it was forcibly peeled off and the adhesive strength was measured.

Comparative Example 5 A photosensitive resin layer surface was exposed to a photosensitive resin layer surface for 120 seconds in the same manner as in Example 4 using a solvent-developing type photosensitive resin original plate (manufactured by DuPont, HLS) having a thickness of 1.70 mm. The height was 0.069. However, when cutting was performed by cutting with a cutter, a saw-like waveform was generated on the surface of the photosensitive resin, and further, the photosensitive resin layer in an unnecessary portion was to be peeled off. It was 650 g / inch when it was forcibly peeled off and the adhesive strength was measured.

Table 1 shows the results of Examples 1 to 5 and Comparative Examples 1 to 5.
Shown in

[0035]

[Table 1]

[0036]

As is clear from Table 1, by using the photosensitive resin plate material of the present invention, the sharpness of the cutting surface of the photosensitive resin layer by the peeling image forming method is excellent, and the peeling work is also possible. It is easy, the printing plate made by the forming method has good image reproducibility and good ink application, and the photosensitive resin layer does not peel off during printing,
Since the printing workability can be improved, it greatly contributes to the industry.

Claims (1)

[Claims] 1. The dynamic hardness of a surface of a photosensitive resin for forming a peeled image measured by an ultra-micro hardness meter DUH201 is 0.
A photosensitive resin plate material for forming a peeled image, which is from 02 to 0.04.