JPS6037455B2 - Photosensitive resin plate material - Google Patents

Description

Detailed Description of the Invention The present invention relates to a methacrylic acid ester polymer in which microgel obtained from a rubber base material and a vinyl monomer is dispersed;
A photosensitive resin composition consisting of a diacrylate or dimethacrylate ester of a dihydric alcohol, which is a photopolymerizable monomer having bifunctionality, a photopolymerization initiator, and a thermal polymerization inhibitor, is colored brown. The present invention relates to a photosensitive resin plate material laminated on a metal support.

In the printing industry, letterpress printing, which uses photosensitive resin as a plate material, has developed rapidly in recent years, but in order to use this printing method in the newspaper industry, it is necessary to print in a short time. Due to the special circumstances of the printing department, which competes for sand separation, there is a demand for a high-speed plate-making process in which the so-called plate-making time required from exposure of an original image to plate-making process is about 6 minutes or less.

In general, it goes without saying that it is important to obtain a relief plate with good reproducibility of the original image, but especially when obtaining a relief plate from a photosensitive resin plate material, it is necessary to expose the plate material through a negative film of the original image. By making the photosensitive resin in the image area of the plate unmeltable and removing the unexposed area with a solvent, it is possible to achieve good reproducibility (abbreviated as relief reproducibility) over the minute parts of the relief image. It is considered important in increasing the commercial value of printed materials.

Furthermore, when a letterpress obtained from the printing village, for example, an original obtained from the photosensitive resin plate material, is subjected to a paper pattern, the original is As mentioned above, it is essential that the leaf has pressure resistance to prevent it from being crushed or cracked, and for this purpose, it is of course important to select a photosensitive resin with strong rut resistance, and also to When the relief is cut perpendicular to the printing plate, it is necessary to form the relief so that the vertical cross section of the relief forms a so-called isosceles trapezoid with a wide base and a narrow top (printed part). Conventionally, plate materials based on photosensitive resins are made by laminating a resin composition obtained from alcohol-soluble polyamide, unsaturated polyester, polyvinyl alcohol conductor, etc. and a photopolymerizable monomer on a metal support. Printing materials are provided.

However, these known printing materials are extremely unsatisfactory in meeting the above-mentioned several requirements. In this respect, for example, when using the above-mentioned known photosensitive resin plate material, there is a drawback that pressure resistance is unsatisfactory in practical terms. The present invention provides a photosensitive resin plate material which does not have the above-mentioned drawbacks and can fully satisfy the above-mentioned problems regarding printing plates, especially photosensitive resin plate materials. The present invention provides a photosensitive resin plate material that is extremely satisfactory in practical terms in terms of stability, reproducibility of relief, shortening of plate-making processing time, etc. Such a plate material is extremely useful and valuable as a high-performance photosensitive resin plate material required for letterpress printing, especially newspaper printing, etc.

Accordingly, the present invention includes 60 to 8 parts by weight of a polymer in which a microgel obtained from a rubber base material and a pinyl monomer is dispersed, and a diacrylate or dimethacrylate ester of a dihydric alcohol. 20 to 4 parts by weight of one type or a mixture, 0.1 to 2 parts by weight of a photopolymerization initiator, and 0.0 parts by weight of a thermal polymerization inhibitor.
This is a photosensitive resin printing plate characterized by comprising a mirror layer of a photosensitive resin composition comprising 0.01 to 2 parts by weight on a brown colored surface of a metal support. Each component of the printing plate of the present invention will be explained below according to the procedure for manufacturing the printing plate.

Wind Photosensitive resin composition: Diacrylic acid, a dihydric alcohol, is added to 60 to 8 parts by weight of a methacrylic acid ester polymer in which microgel, which is a fine particulate rubber material obtained from a rubber base material and a vinyl monomer, is dispersed. 20 to 4 parts by weight of a bifunctional photopolymerizable monomer of one type or a mixture of esters or dimethacrylic acid esters, 0.1 to 2 parts by weight of a photopolymerization initiator, and 0.01 to 0.01 parts by weight of a thermal polymerization inhibitor.
2 parts by weight are added and milled with a heated roll to obtain a photosensitive resin composition.

The methacrylic acid ester polymer in the present invention is a homopolymer of methacrylic acid ester or a copolymer of methacrylic acid ester and other copolymerizable vinyl monomers.

Examples of methacrylate esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and methyl methacrylate and ethyl methacrylate are particularly preferred. Examples of the other copolymerizable vinyl monomers include methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
Examples include polymerizable vinyl monomers such as -ethyl-hexyl, vinyl chloride, vinylidene chloride, butadiene, vinyl acetate, styrene, Q-methylstyrene, vinylpyridine, and acrylonitrile.

A particularly preferred example of the above copolymer is a methyl methacrylate and ethyl methacrylate copolymer containing an acrylate ester as a copolymerization component. The above-mentioned acrylic acid ester polymer used in the present invention has extremely excellent pressure resistance.

Moreover, the microgel in the present invention refers to a fine particulate rubber-based material obtained by graft polymerizing a vinyl monomer onto a so-called rubber-based base material having a particle size of 0.01 to 10 mm. Examples of the rubber base material include polybutadiene-based materials such as polybutadiene and styrene-butadiene copolymer rubber, polyacrylate ester-based polymers such as polybutyl acrylate, ethylene-propylene copolymers, and polyisoprene. Typical examples include ordinary rubber or rubber-like elastic materials.

The pinyl monoisland is a vinyl monomer copolymerizable with the above-mentioned methacrylic acid ester and methacrylic acid ester, and includes common vinyl monomers such as methyl methacrylate, acrylonitrile, and styrene. It is important for the microgel in the present invention that the rubber base material has a particle size of 0.01 to 10 μm. In addition, if the size is larger than 10 Buddhas, the reproducibility of the leaf will be affected.

The weight ratio of the rubber base material and the pinyl monomer is 1:0.1 to 1
:30 is preferable.

Next, the diacrylic acid ester or dimethacrylic acid ester of dihydric alcohol in the present invention includes, for example, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and polyethylene glycol having a molecular weight of 300 to 800. - glycol diacrylate or dimethacrylate such as polyethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate with a molecular weight of 350 to 850, neobentyl glycol dimethacrylate, etc. There is.

These compounds may be used alone in the present invention, or two or more of them may be used simultaneously as necessary. Therefore, a photopolymerizable monomer having monofunctionality, such as a monofunctional compound such as alkoxypolyethylene glycol acrylate or alkoxypolyethylene glycol methacrylate, can be used as the difunctional compound used in the present invention. Even if used in place of a photopolymerizable monomer having
It is weaker in strength than a polymer with a network structure formed by a difunctional compound such as the difunctional photopolymerizable monomer used in the present invention, and cannot withstand the pressure during paper molding. . Examples of the photopolymerization initiator in the present invention include Q-methylbenzoin, benzoin, Q-benzylbenzoin, benzoin methyl ether, benzoin ethyl ether, O-methylolbenzoin, benzoinpropyl ether, benzoin butyl ether, etc. penso, yne derivatives such as tel, and 2-methylanthraquinone, 2-
Anthraquinone derivatives such as ethylanthraquinone, 2-tere-butylanthraquinone, 2-acylanthraquinone, 2-chloroanthraquinone, 2-fromanthraquinone, 2-nitroanthraquinone, 1-chloroanthraquinone, 1-methylanthraquinone, anthraquinone-1-aldehyde Those commonly used in this field can be used.

Furthermore, as the thermal polymerization inhibitor in the present invention, for example, hydroquinone, p-methoxyphenol, catechol, p-
-te ratio-butylcatechol, 2,6-di-rt-butyl-p-cresol, phenol derivatives such as pyrogallol, phenothiazine, P-naphthols, nitro compounds such as nitrobenzene, and penzoquinone derivatives such as p-penzoquinone, chloranil, etc. Hydroquinone or p-methoxyphenol is particularly preferred.

Regarding the weight ratio of each component of the photosensitive resin composition in the present invention, the methacrylic acid ester polymer in which the microgel obtained from the rubber base material and the vinyl monomer is dispersed is 8 parts by weight, and the divalent One type or a mixture of alcohol diacrylate ester or dimethacrylate ester
If the amount is less than 1 part by weight, the solvent resistance of the cured part during dissolution by the solvent when preparing a relief plate will be poor, resulting in surface roughness of the obtained relief plate, and clear printing will not be possible.

On the other hand, when the amount of one or a mixture of diacrylate ester or dimethacrylate ester of a dihydric alcohol is greater than 4 parts by weight with respect to 60 polymerized parts of the above-mentioned acrylate ester polymer, the above-mentioned relief reproducibility is reduced. It's bad again,
It becomes brittle and cannot withstand the pressure of paper molding. If the amount of the photopolymerization initiator is less than 0.1 parts by weight, curing by light when obtaining the above-mentioned letterpress is slow, and even if it is more than 2 parts by weight, the resulting weight increase effect is not so noticeable. Thermal polymerization inhibitor is 0.0
If it is less than 1 part by weight, the effect of preventing thermal polymerization required in the step (C) described below will be small. During the heating and compression molding operation, the photosensitive resin composition hardens and becomes unusable, and if it exceeds 2 parts by weight, photocuring is inhibited. (B) Production of brown-colored metal support : A representative example of the production of the brown-colored metal support in the present invention will be described below.

For example, brown coloring substances such as brown pigments such as Bengara,
For example, it is kneaded with a thinner consisting of cellosolve acetate and butanol and a thermosetting adhesive such as an epoxy adhesive to form a kneaded product with a viscosity that is easy to apply.

This is applied to a metal object of any shape used in the present invention to a predetermined thickness, as will be described later. Before this application, the metal surface is subjected to known pretreatment, for example, when the metal is aluminum. It is desirable to perform a pretreatment such as treatment with zinc phosphate.

Then, the metal support of any shape obtained by applying the kneaded product in this manner is phosphorized to obtain a metal support colored with a brown coloring substance and having a predetermined thickness.

The colored metal support in the present invention may be obtained by coating the surface layer of the brown coloring substance of the colored metal support obtained above with an adhesive such as the epoxy resin described above.

In the present invention, the reason why the surface of the metal support is colored brown is that when producing a letterpress using the printing plate material of the present invention, as described above, the ultraviolet rays irradiated for exposure pass through the negative film of the original image. Furthermore, it passes through the photosensitive resin composition layer and is diffusely reflected on the surface of the metal support that is in close contact with the back surface of the photosensitive resin composition layer, and as a result, as mentioned above, the vertical cross section of the relief becomes an isosceles trapezoid. This is to prevent the above-mentioned relief reproducibility and pressure resistance when making paper molds from being deteriorated as a result. Brown is defined in JIS Z8721-196 as ``Standard color edge''.
(Published by Japanese Standards Association in 1971) Arc 3-5/3
~12,7. Ball 3-5/4-12, 1 pulse 3-5/2-1
2,2.5YR3-5/4-10 and 5YR3-5/
It refers to coloring in the range of 3 to 8, and stations 4/8 to 10, 7. Ball 4
/6-10 and 7. Stations 3/4 to 6 are particularly preferred. To obtain a color within the above range, for example, add yellow lead or titanium white to the petal pattern to give it a yellowish brown color (7.5% if expressed using the standard color chart above).
Arc 3/4,) or carbon hook may be added to the petal to make it dark brown (7. skin 4/6 if expressed using the same standard color standard), and there is a layer between these two to prevent light reflection. There is no difference in effectiveness. However, if a colored substance such as a white, yellow, or gray pigment is used instead of brown, the effects of the above-mentioned relief reproducibility and pressure resistance when making a paper pattern cannot be obtained in the present invention. . Next, the material of the metal support in the present invention includes iron, stainless steel, galvanized iron, aluminum, aluminum alloy, etc., but is not particularly limited.

tq Lamination of photosensitive resin composition and colored metal support: Next, a coextrusion molding method is used to laminate the photosensitive resin composition obtained above and the brown colored metal support obtained in the above procedure. ,
This is carried out by compression molding, casting, etc., but in this case it is best to minimize the thermal history to avoid thermal polymerization, and the preferred method for the above lamination is compression molding using a compression molding machine. It is preferable to obtain the printing plate material of the present invention by laminating the two layers.

The plate material of the present invention obtained as described above is stored in an inert gas atmosphere such as nitrogen gas or carbon dioxide gas before exposure.

Commercially available exposure machines such as arc lamps and high-pressure mercury lamps commonly used in the industry are sufficient for exposure when producing letterpress plates using the plate material of the present invention obtained as described above.
The ultraviolet rays or short-wavelength visible rays generated by this exposure machine are preferably selected to have a wavelength that corresponds to the wavelength range to which the photosensitive resin composition is sensitive.

Next, the solvent used for eluting and removing the uncured portion of the plate material of the present invention after the above-mentioned exposure dissolves the exposed photosensitive resin composition well and dissolves the photosensitive resin composition cured by the above-mentioned exposure. Although the solvent must not dissolve at all, examples of the solvent having such an effect include hydrocarbons, halogenated hydrocarbons, ketones, alcohols, and ethers.

In particular, halogenated materials such as 1,1,1-trichloroethane, which is low in toxicity, stable against heat, and nonflammable, due to the workplace working environment during elution with the solvent, and thermal stability during solvent recovery. Hydrocarbons are preferred. As mentioned above, the plate material of the present invention is exposed through a negative film of the original image to make the exposed part of the plate material indestructible, and the unexposed part is removed with the solvent to obtain a relief. When obtaining the leaf as described above from a photosensitive resin printing plate, the exposure time is shorter than when using the conventional photosensitive resin printing plate mentioned above, and the time required from the above exposure to obtaining a relief plate (so-called plate making time) is shorter. ) is at most 6 minutes or less, which is significantly shorter than the 10 to 1 powder time required for conventional photosensitive resin plate materials. Furthermore, the plate material of the present invention can be used not only as an original plate for paper pattern making as described above, but also as a printing plate for direct printing, so its practical value is extremely high. Examples are shown below, but the present invention is not limited to these Examples in any way. Example 1 Methyl methacrylate 84.0 mm was prepared by dispersing a cyclogel obtained by graft polymerization from 3 parts by weight of polybutyl acrylate (particle size: 0.2 French) and 3 parts by weight of methyl methacrylate.
Methacrylic acid ester polymer obtained by polymerization of mother weight part and 9.4 weight parts of methyl acrylate
After mixing 34 parts of 100 tatetraethylene glycol diacrylate, 0.7 parts of ethyl anthraquinone, and 0.3 parts of tapermethoxyphenol, the mixture was kneaded for 4 minutes with a 10,000 roll heated roll to obtain a photosensitive resin composition.

An aluminum support (thickness: 0.3 ribs) colored with a brown pigment (7. mark 3/6 on the standard color scale) was coated with epoxy adhesive (trade name: Epoki-820-4, manufactured by Mitsui Toatsu Chemical Co., Ltd.). X
) to a thickness of about 5 mm.

1. Using a compression molding machine, the above-mentioned photosensitive resin composition was bonded to the above-mentioned colored aluminum support by pressing at 14,000 for 2 minutes. Obtained a photosensitive resin plate. After this photosensitive resin plate was left in a carbon dioxide gas flow (flow rate 2 so/min) for 2 hours, it was immediately exposed to light using the following exposure device. A negative film (original negative film) having thin lines with a thickness of 20 to 150 mm every 10 ridges and halftone dots is closely attached to the photosensitive resin plate, and a Fox W high-pressure mercury lamp (made by Iwasaki Electric ■) is attached. Ultraviolet light exposure was performed for 15 minutes at a distance of 62 arcs using an Ainicordorfin 2000). 1/5000 on the exposed photosensitive resin plate at a spray pressure of 4k9/ground.
After spraying 1,1-trichloroethane for 2.5 minutes to dissolve the uncured portion, it was dried with hot air of about 80 q0 for 2 minutes, and then exposed to backlight for 2 minutes using the above exposure machine to form a photosensitive resin letterpress (original plate). I got it. Proof printing was performed on the above photosensitive resin letterpress using a proofing machine U (Vander Cook Universal M type).

When the printing pressure was changed to 0, 3, 6, 9, 12hjls, printing was thin with printing pressure of 0.3njls, but with printing pressure of 6, 9,
With 12hils, fine line drawings were reproduced and the gradation of halftone dots was also good, resulting in practically satisfactory printing reproducibility, and the reproduction accuracy for negative film was good. Further, a paper pattern was made from the photosensitive resin letterpress using a rolling machine (manufactured by Kaneda Kikai).

Layer paper pattern paper (non-pack mat made of special paper, 13% water added) on photosensitive resin letterpress and roll at 180k9/cm.
A paper pattern was obtained by making a paper pattern. The performance as an original plate was evaluated as follows.

{1' When a paper pattern was made from the photosensitive resin letterpress using a rolling machine, the state of the pongee line in the line drawing area was observed.

When the paper cannot withstand the rolling pressure and becomes thin, and has deformations such as bends, corrugations, and chips, this is transferred to the paper pattern and significantly reduces the reproduction accuracy.

In this regard, there was no deformation of the thin wire in the present example. ■
The contour of the relief part of the photosensitive resin relief plate was measured using a contourer (manufactured by Mitoyo Seisakusho ■).

If the shape of the relief part is an isosceles trapezoid, the reproduction accuracy is good, but
If the bowl is in an upside-down shape (with a bulge in the middle), the accuracy of reproduction will drop significantly. Furthermore, if the shoulder angle formed by the side and top sides of the isosceles trapezoid is not appropriate, it will take on a so-called high-rise building shape, resulting in poor pressure resistance against rolling pressure. In this respect, in the above-mentioned embodiment, the outline of the relief portion was an isosceles trapezoid, and the reproduction accuracy was good.

Next, a polypropylene reproduction plate was obtained using the above-mentioned paper pattern as a matrix in the following manner.

That is, the two mother molds were mounted on a roll with a diameter of 600 mm and the inside of which was water-cooled, and a press roll having the same diameter as the roll including the thickness of the paper mold was placed opposite to this. Pass the steel belt between these two. The gap between these two rolls is determined by adding 0.5 to the thickness of the steel belt and the thickness of the thinnest part of the paper pattern. The temperature of the push roll example is maintained to such an extent that the molten polypropylene supplied onto the steel belt does not solidify. Melt index (ASTM
A crystalline propylene homopolymer having a D-12 paper-69) of 7.0 and containing 0.1% by weight of para-tertiary butyl-benzoic acid basic aluminum salt was uniformly supplied in a state of heating and melting to 22,000. , embossing between two rolls.

The embossed copy plate is almost cooled and solidified during one quarter of a turn of the paper mold side roll, at which point it is cooled by water from the outside through a steel belt, and after another quarter turn, the copy plate is removed from the paper pattern. Peeled off. When the thus obtained polypropylene reproduction printing plate was subjected to proof printing using the above-mentioned proofing press in the same manner as the above-mentioned photosensitive resin letterpress printing plate,
Fine line drawings were reproduced, the gradation at the end point was also good, and printing reproducibility that was satisfactory for practical use was obtained, and the reproduction accuracy for negative film was good.

Comparative Examples 1-2 Two types of metal supports shown below were prepared as comparative samples.

Comparative sample 1: Grained aluminum support (0.3 feet thick).

Comparative sample 2: Aluminum support (0.3 ribs thick) colored with white pigment (also N9 on the standard color chart).

These metal supports were used in place of the brown-colored aluminum support (thickness: 0.3 mm) in Example 1, and the other conditions were the same as in Example 1, and a photosensitive resin letterpress plate was prepared. and a polypropylene reproduction printing plate was obtained.

When evaluated as an original plate, in all of Comparative Examples 1 and 2, the string line was crushed, bent, corrugated, chipped, and other deformations due to the rolling pressure during paper pattern making.

This deformation is transferred from the paper mold to the polypropylene reproduction printing plate, and when proof printing is performed on this polypropylene reproduction printing plate, the crushed, bent, wavy, chipped, etc. of fine lines are printed as they are, which significantly reduces the reproduction accuracy for negative film. lowered. In addition, when the outline of the relief part was measured using a contourer, it was found to be in the shape of an upside-down bowl.

For this reason, when proof printing was performed using a photosensitive resin letterpress plate and a polypropylene reproduction printing plate, when printing at a printing pressure higher than ahils, stains were caused by the printing ink around the printed type, etc., and the size of the print was larger than that of the negative, and the reproduction was The accuracy was significantly reduced. Example 2 Polybutyl acrylate (
Methacrylic acid ester obtained by copolymerization of 81 parts by weight of methyl methacrylate and 9 parts by weight of methyl acrylate, in which microgel obtained by graft polymerization from 5 parts by weight of particle size 0.2r) and 5 parts by weight of methyl methacrylate is dispersed. Polymer: 100 polyethylene glycol dimethacrylate 40 polyethylene glycol dimethacrylate with an average molecular weight of 536
10/21 Ethylanthraquinone
1 tap-methoxyphenol 0.3
After mixing the mixture, the mixture was kneaded for 4 minutes using a 10,000 mm hot roll to obtain a photosensitive resin composition.

Claims (1)

[Claims] 1 Methacrylic acid ester polymer 60-8 in which microgel obtained from a rubber base material and a vinyl monomer is dispersed
0 parts by weight, 20 to 40 parts by weight of one type or mixture of diacrylic ester or dimethacrylic ester of dihydric alcohol, 0.1 to 2 parts by weight of photopolymerization initiator, and 0.01 to 2 parts by weight of thermal polymerization inhibitor. 1. A photosensitive resin plate material comprising a photosensitive resin composition laminated on a brown colored surface of a metal support.