JPH043162A - Solid plate material made of photosensitive resin for printing plate - Google Patents

Abstract

PURPOSE:To improve flexibility, ink resistance and printing durability by imparting a phase sepn. structure of a sea-and-island form to a photosensitive layer. CONSTITUTION:The photosensitive layer has the phase sepn. structure of the sea-and-island form. The sea component phase preferably consists mainly of a compsn. prepd. by solidifying an ethylenic unsatd. compd. with a small amt. of a hydrophilic resin and if necessary, a gelatinizing agent. On the other hand, polyene, such as, for example, polybutadiene or polyisoprene or rubber components as the derivatives thereof are used as the island component. The solid plate material made of the photosensitive resin having the photosensitive layer which possesses such specific form yields the printing plate which exhibits excellent developability with water or alcohol and has the polar ink resistance, flexibility and further printing durability in combination.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photosensitive resin solid plate material for printing plates, and more particularly to a photosensitive resin solid plate material for printing plates that can be developed with water or alcohol. In particular, it relates to a photosensitive resin solid plate material that can be developed with water and provides a printing plate with good flexibility, ink resistance, and printing durability as a flexible printing plate or flexographic printing plate. .

[Prior Art J A photosensitive resin composition in which an elastomer such as chlorinated rubber, styrene-butadiene block copolymer, and polyurethane is used as a carrier resin component and an ethylenically unsaturated compound and a photopolymerization initiator are arranged thereon is called an elastomer. It is useful as a flexographic printing plate material by taking advantage of its characteristics, for example, US Pat.
Many proposals have been made, such as in Publication No. 1-43374.

However, since such photosensitive resin solid plate materials require halogenated hydrocarbon development, they have problems such as health problems and environmental pollution.

On the other hand, when considering numerical photosensitive resin printing plate materials, not specifically limited to flexo printing applications, water- or alcohol-developable solid printing plate materials are well known.
As shown in Japanese Patent Publication No. 6-26125, Japanese Patent Publication No. 50-32645, Japanese Patent Publication No. 57-28485, etc., printing in which the photosensitive layer is a photosensitive resin composition whose carrier resin component is mainly water- or alcohol-soluble polyamide. It is widely known as printing material. However, although printing plates obtained from such water- or alcohol-developable solid printing plate materials are resistant to oil-based inks, they are not resistant to inks containing polar solvents such as aqueous or alcohol-based. It is something that we do not have.

In view of the above problems, the present inventors have developed the possibility of developing a photosensitive resin solid plate material that can be developed with water or alcohol and is resistant to inks containing polar solvents such as water or alcohol. As a result of our studies, we found that we could achieve the desired photosensitivity by gelling and solidifying a large amount of photocurable components, which are mainly liquid components, using a small amount of a specific resin component and a specific component known as an organic solvent gelling agent. It was discovered and proposed that a solid resin plate material can be obtained (for example, Japanese Patent Application Laid-open No. 63-278053, Japanese Patent Application Laid-open No. 63-287845, etc.).

[Invention or Problems to be Solved] The object of the present invention is to further develop and improve the techniques described in JP-A-63-278053 and JP-A-63-287845, and in particular, to develop The object of the present invention is to provide a photosensitive resin solid plate material that provides a printing plate with improved flexibility, ink resistance, and printing durability as a possible and practical flexible printing plate or flexographic printing plate.

[Means for Solving the Problems] The object of the present invention is achieved by a photosensitive resin solid plate material for a printing plate, characterized in that the photosensitive layer has a phase-separated structure in the form of sea islands.

In other words, the present inventors solidified a large amount of ethylenically unsaturated compounds with a small amount of a specific resin that had not been previously considered for use as a solid plate material, and by applying this to a photosensitive resin composition, the inventors achieved an unexpected result. It has been discovered that this material can be used as a photosensitive resin printing plate material that has excellent developability and is suitable for a wide range of inks. A photosensitive resin solid plate material with a photosensitive layer that generates a specific form created by a combination of molding conditions exhibits excellent water or allol developability, polar ink resistance, flexibility, and printing durability. The present invention was achieved by discovering that it is possible to provide a printing plate having both of the following.

The specific form in the present invention is that the photosensitive layer has a sea-island phase separation structure, which means that the photosensitive layer of conventional photosensitive resin solid plate materials for printing plates has basically a uniform form. It is fundamentally different from

Here, the sea-island phase separation structure in the photosensitive layer of the present invention refers to a sea component phase consisting of one or more components and having a homogeneous morphology and a sea component phase having a homogeneous morphology in any cross section of the photosensitive layer. One or two components different from those constituting the phase
It mainly consists of an island component layer consisting of at least one species, and has a form in which the island component layer exists substantially dispersed in the form of islands in the sea component phase. Since the shape of the island component layer is basically circular or elliptical in any cross section of the photosensitive layer, it can be considered that it has a three-dimensionally discontinuous spherical shape.

The volume occupied by the spherical bodies of the island component layer in the photosensitive layer is preferably 5 to 70% by volume, more preferably 10 to 60% by volume, and this is less than 5% by volume. If the amount is more than 70% by volume, the effect of improving the printing durability of flexographic printing plates, which is the main objective of the present invention, will be reduced, and if the amount is more than 70% by volume, the water developability will be insufficient.

It is preferable that the components constituting the homogeneous phase and the components constituting the island component layer are incompatible with each other.

According to the present invention, it is possible to have a large number of two or more types of island component layers that are incompatible with each other in a sea component phase having a homogeneous morphology, and a sea component layer having such two or more types of island component layers The printing plate obtained from the photosensitive resin solid plate material for printing plates with a sea-island photosensitive layer has particularly good water developability and water resistance, and has excellent printing durability as a water-developable flexographic printing plate suitable for use with water-based inks. It becomes something.

In addition, in the present invention, there are no particular limitations on the shape or size of the particulate phase dispersed in the form of islands in the sea component phase.
Preferably, the total islet component phase has an independent spherical shape of 50% by volume or more, more preferably 70% by volume or more, or in the range of 50 to 1μ, more preferably 30 to 1μ, and even more preferably 20 to 1μ. If the amount of the 50 to 1 μm independent spherical component phase is less than 50% by volume, the water developability is likely to be poor and the relief shape of the printing plate is also likely to be poor.

The photosensitive resin solid plate material for printing plates of the present invention can be developed with water or alcohol, and the composition and manufacturing method are not particularly limited as long as the photosensitive layer has a sea-island phase separation structure. It is preferable that the sea component phase mainly consists of an ethylenically unsaturated compound solidified with a small amount of a hydrophilic resin and, if necessary, a gelling agent.

Preferred sea ingredients include the following (1), (2) (
A hydrophilic resin as a polymeric gelling agent is added to 100 parts by weight of an ethylenically unsaturated compound containing at least 50% by weight of acrylates or methacrylates represented by the general formula (3) or their derivatives. , preferably 3 to 30 parts by weight, preferably 5 to 15 parts by weight of polyamide or polyether amide having polyethitone oxide segments, and furthermore N-
One or more gelling agents selected from acyl amino acid derivatives, alkyl group-substituted or unsubstituted benzylidene sorbitols, or 12-hydroxystearic acid 1-
It is preferable to contain 30 parts by weight, preferably 3 to 15 parts by weight, and the use of these gelling agents is effective for giving the photosensitive layer of the solid plate material of the present invention a preferable sea-island structure.

O C)+2 = C-C-0-+L+-nO-4- C-L
Oh H[1 R00 CI(2”C-C-0-qRH+, 0-C4-C-0→
R30+-,,,I(Cth ”C-C-0-C1(2
-Ctl-CL -0-Ri+1 1 (R1 is rN, R2 is CH2CH2 or CH2CH2, Ctl3 R3 is an alkylene group having 2 to 6 carbon atoms, R4 is an alkyl group having 4 to 14 carbon atoms or an alkyl group-substituted or unsubstituted phenyl group,
X is a dicarboxylic acid residue having 4 to 12 carbon atoms, n, m are integers from 1 to 10).

On the other hand, although it is not particularly limited as an island component,
Preferably, rubber components such as polyenes such as polybutadiene or polyisoprene or derivatives thereof, rubber components such as epichlorohydrin rubber, aliphatic hydrocarbon rubber, and polyurethane, polyamide, polyester, etc. having a polyether structure as a soft segment are preferable. It is preferable that the elastomer component mainly consists of these elastomer components, and more preferably that it consists of two or more of these elastomer components.

In addition, depending on the required characteristics of the target printing plate, it is possible to use a sea component or an island component and a plasticizer component.
As such plasticizer components, compounds known as plasticizer components for polyamide photosensitive resin compositions are mainly used, such as alkylbenzenesulfonamides and polyalkylene glycols. As the photopolymerization initiator for rapidly photopolymerizing the photosensitive layer composition constituting the printing plate of the present invention, all conventionally known compounds can be used. Examples include benzoin alkyl ethers, benzophenones, anthraquinones, hensyls, acetophenones, and diacetyls. Furthermore, in order to increase the thermal stability of the photosensitive composition, all conventionally known polymerization inhibitors can be used. Preferred polymerization inhibitors include phenols, hydroquinones, catechols, and phenothiazine. Other additives include amine compounds, dyes, pigments, surfactants,
Antifoaming agents, ultraviolet absorbers, fragrances, plasticizers, etc. can be added.

The method for producing the photosensitive resin solid plate material for printing plates having a phase separation structure of the photosensitive layer or sea-island type of the present invention is not particularly limited, but may include appropriate photosensitive layer constituents, stock solution preparation method, conditions, and is manufactured based on the balance of molding methods and conditions, and there are manufacturing methods such as casting and cooling film formation after melting and mixing, dry film formation after solution mixing, and kneader-kneading push-pull compression roll molding. Selected appropriately.

A preferred manufacturing method includes, for example, adding a small amount of hydrophilic polyamide and dibenzylidene sorbitol, N as a polymeric gelling agent to acrylate or methacrylate containing a hydrophilic group such as a hydroxyl group in the molecule.
- General gelling agents such as acylamino acid amides and other compounds necessary for photosensitive compositions are dissolved by heating, and a lipophilic elastomer component is added to this solution, such as carboxylated polyoxyethylene lauryl ether or its like. After uniformly dispersing using mechanical force and the use of a compound having surfactant action such as a derivative such as a tertiary amine salt or a compound known as a neutral surfactant, it is cast onto a support. Examples include methods of cooling and solidifying.

As a support for the printing plate material of the present invention, a metal plate made of steel, stainless steel, aluminum, copper, etc., which has an adhesive layer as necessary, a plastic sheet such as a polyester film, a synthetic rubber sheet, etc. is used, and the photosensitive layer is It is usually formed to a thickness of 0.61 to 10 mm, and its upper surface is 0.06 mm to 10 mm thick.
It is preferable to have a water-soluble or water-dispersible protective film of 0F, ~10μ.

In order to form a relief image for printing using the printing plate material of the present invention, a negative or positive original film is closely adhered to the photosensitive layer prepared as described above, and usually
High-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, chemical lamps centered on the wavelength of 450 mμ,
It is irradiated with ultraviolet light from a carbonark lamp, etc., and is cured by a photoreaction. A relief is then formed on the support by dissolving or dispersing the uncured portion in water or alcohol using a spray or brush developing device.

The photosensitive resin solid plate material of the present invention is useful as a solid printing plate material intended for printing plates developed with water or alcohol, and exhibits the most effect when used as a flexible printing plate material. This is the most excellent water-developable flexographic printing plate material, and it is a printing plate that has unprecedented water-developability, flexographic ink solvent resistance, and printing durability.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples. The morphological photographs used in the present invention were obtained by completely curing and fixing the photosensitive layer of the photosensitive resin solid plate material with ultraviolet rays, and then staining the sliced cross section with osmic acid using a scanning electron microscope (JSM-T300 manufactured by JEOL Ltd.). (type), composition images of backscattered electron images measured at an acceleration voltage of 10 Kv, and the magnification is indicated each time.

Note that the numbers used in the following examples are parts by weight.

Synthesis Example 1 A copolyamide comprising the following components was synthesized based on a known recipe (for example, JP-A-55-79437).

ε-caprolactam, / Equimolar salt of hexamethylene diamine and adipic acid / Equimolar salt of α,ω-diaminopropylpolyoxyethylene (number average molecule 11000) and adipic acid = 20/20/60 Copolymerization obtained here When the terminal groups of polyamide are quantified, the primary amino groups are 4.0×10−
5 morphs/g.

The carboxyl group was 2.1XIO-5 mol2/g, and the number average molecular weight as determined by the terminal group quantitative method was approximately 33,000.

Synthesis Example 2 A polyether ester amide consisting of the following components was synthesized based on a known recipe (for example, JP-A-58-1.1.7537).

ε-caprolactam/polyethylene glycol with a number average molecular weight of 1000 and equimolar terephthalic acid mixture = 40/
70 The polyether ester amide obtained here had a GPC number average molecular weight in terms of nylon 6.6 of 28,000, and a terminal carboxyl group of 2.9 Xi05 mol/g.

Synthesis Example 3 A polyether ester amide elastomer comprising the components listed in F was synthesized based on a known formulation (for example, Japanese Patent Publication No. 2-372).

Laurolactam 7/Equimolar adipic acid mixture with poly(tetramethylene oxide) glycol having a number average molecular weight of 650 - 40,.../70 GPC nylon 6.6 equivalent number average molecular weight of the polyether ester amide rated here is 25,000.

Synthesis Example 4 A polyether ester amide elastomer comprising the following components was synthesized based on a known formulation (for example, Japanese Patent Publication No. 2-372).

Laurolactam/poly(propylene oxide) glycol with a number average molecular weight of 1000 and equimolar adipic acid mixture = 40,.../70 The number average molecular weight of the polyether ester amide obtained here in terms of GPC nylon 6.6 is It is 22000.

Synthesis Example 5 1 mol of isophoronediamine and 2-
Ethylhexyl glycidyl ether 1 mole adduct
70'C, 3 hours reaction) was synthesized.

Example 1 10 parts of the polyetheramide obtained in Synthesis Example 1, 12 parts of the polyetheresteramide elastomer obtained in Synthesis Example 3, 0.05 part of heat stabilizer hydroquinone,
15 parts of caprolactone modified 2-hydroxyethyl methacrylate, 23 parts of β-hydroxyethyl β'-acryloyloxyethyl phthalate, 10 parts of 2-acryloyloxyethyl hexahydrophthalic acid, and maleic anhydride modified polybutadiene "M2O0O-20" ( (manufactured by Japan Petrochemical Co., Ltd.) was mixed, heated, and heated to 105°.
After stirring at C for 1 hour, Additive 1 shown in Synthesis Example 5
After stirring at 140°C for 11 hours, 1.5 parts of benzyl dimethyl ketal was added as a photopolymerization initiator, and 7 parts of hydrocarboxylated penta(oxyethylene) lauryl ether were added as other additives/JlU agent components. and 5 parts of dibenzylidene sorbitol, N-lauroyl-■,-
5 parts of glutamic acid α/γ-di-n-butylamide was added and dissolved. The solution obtained in this way is coated with a polyester adhesive and cured in advance to a thickness of 1 to 0.
The thickness of the photosensitive layer is 1700 μm on a 0μ polyester substrate.
A solid photosensitive resin printing plate material was obtained by casting, coating, and standing at room temperature so that the particle diameter was μ.

The morphological diagram of the photosensitive layer of this printing plate material (magnification: 1000 times) is as shown in FIG. 1, and it showed a phase separation structure in the form of a sea-island structure containing two or more types of island component phases.

On the photosensitive layer of this printing plate material, a gray scale negative film for sensitivity measurement (manufactured by Stouffer, 21 Steps) was applied.
5sensitivity Guide) and negative film 150 lines for image reproducibility evaluation 3%, 5%, 10
% halftone dots, diameter 200μ, and 300μ independent points, width 50
and 70μ fine wire) were placed in vacuum contact and exposed for 3 minutes from a distance of 1 m using a 2KW ultra-high pressure mercury lamp.

After the exposure was completed, development was carried out using a brush type washing machine (liquid temperature: 25° C.) containing neutral water. Depth 1000 in 4 minutes development time
A relief image of μ was formed. As a result of evaluating this relief image, it was found that the clay scale part remained up to 14 steps, and the image part was almost perfectly reproduced, including 5% halftone dots, 300μ independent points, and 50μ thin lines. The hardness of the printing plate was 60 Shore A hardness after the post-exposure to actinic light. 700 using water-based ink using this printing plate.
A flexographic printing test was conducted on 00 sheets and good printed matter was obtained. This printing test was carried out using a "Marcanday" 5DG12-3 flexographic label printing machine (Marcanday Co., Ltd.) using water-based ink (G-Man Co., Ltd.).

Example 2 10 parts of the polyether ester amide obtained in Synthesis Example 2 was mixed with 0.05 part of heat stabilizer hydroquinone, 15 parts of caprolactone-modified 2-hydroxydiethyl methacrylate, and β
-33 parts of hydroxyethyl β' acryloyloxyethyl phthalate, maleic anhydride-modified polybutadiene "N"
i 2000-20” (manufactured by Nippon Petrochemical Co., Ltd.) 20
After mixing, heating, and stirring at 105°C for 1 hour, 10 parts of the additive shown in Synthesis Example 5 were added, and 1-4
After stirring for 11 hours at 0°C, 2 parts of glycidyl methacrylate was added, and after further heating and stirring for 30 minutes, 1.5 parts of benzyl dimethyl ketal was added as a photopolymerization initiator, and hydrocarboxylated penta( 3 parts of (oxyethylene) lauryl ether, 2 parts of dibenzylidene sorbitol, and 2 parts of N-lauroyl-glutamic acid-α·γ-di-n-butylamide were added and dissolved.

The solution obtained in this manner was cast, applied, and left at room temperature on a 100 μm thick polyester substrate on which a polyester adhesive had been applied and cured in advance so that the photosensitive layer had a thickness of 1700 μm. A solid photosensitive resin printing plate material was obtained.

The photosensitive layer morphology diagram (magnification: 1000 times) of this printing plate material is as shown in FIG. 2, and it showed a phase separation structure in the form of sea islands.

A printing plate prepared from this photosensitive resin printing plate material in the same manner as in Example 1 was able to produce good printed matter in the same 10,000-sheet printing test as in Example 1.

Example 3 In Example 1, the elastomer obtained in Synthesis Example 4 was used instead of the elastomer obtained in Synthesis Example 3, and a solid photosensitive resin printing plate material was similarly obtained.

The photosensitive layer morphology diagram (magnification: 1000 times) of this printing plate material had a sea-island phase separation structure as shown in FIG.

Comparative Example 1 20 parts of the polyether amide obtained in Synthesis Example 1 was mixed with 0.05 part of hydroquinone as a heat stabilizer and modified caprolactone 2-
It was added to a mixture of 15 parts of hydroxyethyl methacrylate and 55 parts of β-hydroxyethyl β'-acryloyloxyethyl phthalate, heated, and heated to 105°C to form a 1-
After stirring for an hour, 10 parts of the additive shown in Synthesis Example 5 were added, and after stirring at 140°C for 11 hours, 1.5 parts of benzyl dimethyl ketal as a photopolymerization initiator was added and dissolved. The solution obtained in this manner was cast, applied, and left at room temperature on a 100 μm thick polyester substrate on which a polyester adhesive had been applied and cured in advance so that the photosensitive layer had a thickness of 1700 μm. A solid photosensitive resin printing plate material was obtained.

The photosensitive layer morphology diagram (magnification: 5,000 times) of this printing plate material is as shown in FIG. 4, and showed a structure of approximately uniform morphology.

A printing plate prepared from this photosensitive resin printing plate material in the same manner as in Example 1 showed remarkable thickening in the print area in the same printing test as in Example 1.

Comparative Example 2 The photosensitive layer morphology diagram (magnification: 10,000 times) of “CYREL” (DUPONT), a commercially available halogenated hydrocarbon-developed photosensitive resin printing plate material, is as shown in Figure 5, and is almost uniform. It shows a structure. Flexographic printing plates obtained from this printing plate material had excellent printability or had no water developability.

Comparative Example 3 The photosensitive layer morphology diagram (magnification: 10,000 times) of "Trelief" WSS (Toshisha Co., Ltd.), which is a commercially available water-developable photosensitive resin printing plate material, is as shown in Fig. 6, and it is approximately uniform. It shows the structure of the morphology. A printing plate obtained from this printing plate material has no printability with water-based inks.

Comparative Example 4 APRFP6, a commercially available liquid photosensitive resin printing plate material
0” (manufactured by Asahi Kasei ■) Photosensitive layer morphology diagram (magnification = 11 parts)
is as shown in FIG. 7, and shows a structure with an approximately homogeneous morphology. This printing plate material is liquid.

[Effects of the Invention] Since the present invention is configured as described above, flexibility, printing durability,
This makes it possible to provide a water-developable photosensitive resin solid printing plate material that provides a water-resistant printing plate.

[Brief explanation of drawings]

1, 2 and 3 are cross-sectional views showing examples of the particle structure of the photosensitive layer of the photosensitive resin solid plate material for printing plates obtained by the present invention, and FIGS. FIG. 3 is a cross-sectional view showing the particle structure of the photosensitive layer of the photosensitive resin solid plate material for printing plates.

Claims (3)

[Claims] (1) A photosensitive resin solid plate material for printing plates, characterized in that the photosensitive layer has a phase separation structure in the form of sea islands. (2) The photosensitive resin solid plate material for printing plates according to claim (1), characterized in that it contains two or more types of island component phases. (3) A claim characterized in that 50% by volume or more of the island component phase has an independent spherical shape with a diameter of 50 to 1 micron (
The photosensitive resin solid plate material for printing plates described in 1).