JPS5830755A - Exposing method - Google Patents

Abstract

PURPOSE:To obtain a resin letterpress plate having high relief and strong printing resistance, by forming a photosensitive resin layer on a support in >=2 times, exposing the layer first to a light image enlarged in image line thickness, gradually reducing the enlarging rate, and finally executing contact exposure, and developing each resin layer after each exposure. CONSTITUTION:The first photosensitive resin layer 3 is formed on a support 1 of an aluminum or the like metal plate or a polyester or the like resin plate or a sheet, and a transparent original image sheet 6 is arranged opposite to the layer 3 spaced by a gap 4, and the layer 3 is irradiated with actinic rays 7 through the gap 4 of air or the like to form the enlarged image 2 of the original 5 and harden it. So lon as the gap 4 has a refractive index lower than that of the sheet 6, any kind of medium will do. The enlarging rate depends upon said index and the distance. In place of said process, an original sheet having thickened image lines may be contact exposed. Another photosensitive resin layer 31 same as that of the layer 3 or having good adhesiveness to the layer 3 is formed on it, the sheet 6 is brought into close contact with the layer 31, and this is contact-exposed to form a hardened layer 21 as large as the image 5. Images lower in enlarging rate than the image 2 may be formed in >=2 times and finally contact-exposed, thus permitting a resin letterpress plate having high relief and strong printing resistance, and breaking resistance or the like to be obtained.

Description

[Detailed description of the invention] The present invention relates to a novel method for manufacturing printing plates.

More specifically, the present invention is directed to a method for producing a photosensitive resin letterpress plate useful for obtaining a printing plate requiring a high relief layer such as a 7-inch printing plate.

Conventionally, V-7 is formed by irradiating the photosensitive resin layer with actinic light through a transparent body containing a solid liquid, photocuring selected portions of the photosensitive resin layer, and removing uncured portions.
It is also known to use this as a printing material.

A common method for producing a photosensitive resin relief plate is, for example, by placing a photosensitive resin layer with a thickness of aS to 1000 mm on a support, and adhering a negative film directly or through a thin transparent protective cover. , actinic light e.g. wavelength 2000 ~
A light beam of 8000 angstroms is irradiated to harden the photosensitive resin layer in the portion corresponding to the transparent solid liquid of the negative film, and a cleaning solution (e.g. aqueous alkaline solution, aqueous surfactant solution, etc.) is applied.
After insolubilizing K, the uncured resin is dissolved and removed with the above-mentioned cleaning solution, and after drying, depending on the case, the resulting relief is exposed to actinic light again. can get.

Such photosensitive resin layers can be either solid or liquid at room temperature, and a large number of resin compositions have been proposed and used.

The relief thickness of printing plates used for newspaper printing, books, and general printing is approximately 1.0 m or less, but for printing materials with poor surface smoothness such as rough paper and kraft paper two-tiered poles, In order to prevent ink stains on the non-printing surfaces, printing plates with a high relief thickness of several ym are required.

However, in the conventional manufacturing method of photosensitive resin letterpress printing plates, in order to obtain a thick relief surface, it is necessary to lengthen the irradiation time of actinic light, which lowers the degree of relief. In addition, in resin plates with thick relief, image areas with large areas such as capital letters, solids, and halftones can withstand the printing pressure during printing, but fine lines and small dots cannot withstand the printing pressure, resulting in damage to the relief. The problem is that the printing durability is low due to the occurrence of chips and the like.

As a result of intensive research into ways to solve these problems with photosensitive resin letterpress, the inventor found that LO! In a printing plate with a high relief thickness of approximately 1.5 cm or more, the resin has a wider direct area of adhesion at the base of the relief (the part of the relief on the support side) to the support than a resin plate made by a normal method. He discovered a method for manufacturing letterpress plates and completed the present invention. That is, the present invention provides an exposure method in which a photosensitive resin layer provided on a support is irradiated with actinic rays from the surface through a transparent image body to form a cured resin part corresponding to the transparent part; ) The transparent photosensitive resin layer is applied in two or more parts, and (II) At least the photosensitive resin layer applied in the first process is used to irradiate with actinic rays with a gap between the surface of the photosensitive resin layer, or (b) pass through a deformed transparent image body in which the transparent part of the transparent image body is enlarged, and In addition, actinic rays are irradiated with a gap between the surface of the wrinkled photosensitive resin layer and the surface of the photosensitive resin layer (hereinafter this may be referred to as 1st stage exposure'). The photosensitive resin layer is irradiated with actinic rays through the transparent image body, leaving a substantial gap between the transparent image body and the surface of the photosensitive resin layer (hereinafter, this will be referred to as 1 final stage exposure 1). This is an exposure method characterized by the following.

Examples of the support used in the present invention include metal plates made of iron, stainless steel, zinc, aluminum, etc., rubber sheets made of natural rubber, synthetic rubber, etc., celluloid, and polyethylene.

Polypropylene, polyethylene terephthalate.

Examples include resin sheets such as solid photosensitive resin sheets, films, and laminates thereof. Such a support has a thickness of 0.01 to several millimeters, and an antihalation layer, an adhesive layer, etc. may be provided on the surface, if necessary. Further, a laminate in which a cured photosensitive resin layer of 0.02 mm to several millimeters is provided on the above-mentioned plate, sheet, or film can be mentioned. In the case of a support having a cured photosensitive resin layer,
The formation of the cured layer may be performed separately from the process of the present invention, or may be performed in parallel with, before or after the first stage exposure. In this case, the exposure to form the cured layer is performed from the side opposite to the first stage exposure.

The photosensitive resin used in the present invention may be the same as that used as a part of the support and the one that is provided in several parts, but it is also possible that each of the photosensitive resins is different. good. However, if the composition is different,
It is more desirable that the components of the resin that are in contact with each other have compatibility with each other. For example, for resins based on polyurethane and poly7dide, resins containing urethane compounds having -CONH- groups are preferred.

Furthermore, for resins based on alkali-soluble polymers having carboxyl groups, resins based on unsaturated polyesters also containing carboxyl groups are preferred.

A combination of 5IIC and 5IIC having functional groups having mutual affinity is desirable because it provides good adhesion at the interface.

In addition, the resin on the surface of the photosensitive resin layer that is exposed to light during support formation and the initial stage may be impregnated with an excessive amount of thermal polymerization inhibitor to delay the curing reaction, or in the case of anaerobic resin, oxygen or If actinic light is irradiated with the surface exposed to air, the surface portion of the resin layer will be uncured or insufficiently cured, and when the photosensitive resin layer is formed in the next step or exposed, the photosensitive resin will be damaged. As the curing process progresses, it can be integrated with the insufficiently cured area and harden to obtain a strong adhesive force. In addition, if the adhesiveness is poor, this can be solved by sandwiching a third component having adhesiveness at the interface.

Furthermore, various combinations of so-called solid photosensitive resins and liquid photosensitive resins may be used.

In the present invention, a layer of the photosensitive resin as described above is formed on a support in two or more parts to obtain a desired thickness, and at the stage of forming each layer, appropriate solid-liquid exposure is carried out to trap the layers. This is to optimize the shape of the relief finally obtained. At this time, the photosensitive resin closer to the support is exposed to a wider range of light than the layer farther away. Such wide exposure can be performed using the transparent image body used in the final stage exposure, or it can be performed using a modified transparent image body whose transparent part is enlarged from the transparent solid liquid. can. In the case of using a transparent image body, when exposing with a gap between the transparent image body and the surface of the photosensitive resin layer, a more expanded area is exposed due to the refractive index. FIG. 1 shows the raw salt. A photosensitive resin layer 3 is provided on a support plate 1, and a transparent image body 6 is placed with a gap 4 between the support plate 1 and the photosensitive resin layer 3. The active light +17 enters the interior through the transparent part 5 of the transparent wafer body 6, but if there is no space #114, the light rays entering the photosensitive resin part like the third wJ will not be missed much. On the other hand, in FIG. 1 where there is a gap 114, the light rays converge at the gap 114 and a considerably wide area can be exposed and cured. As can be easily understood by looking at FIG. 1, if a modified transparent painted monk body having an enlarged transparent part 2' is used, the modified transparent painted monk body can be substantially freed from the photosensitive resin layer 3. The cured resin portion 2 can be formed by placing it on top and exposing it to light.

After forming the thus enlarged cured resin portion 2, a photosensitive resin layer is further provided thereon, and a desired relief can be obtained by directly exposing the layer to light. FIG. 2 shows this principle. A photosensitive resin layer 31 is further provided on the photosensitive resin layer 3 having the enlarged hardened portion 2 formed in the previous step, and a transparent image member 6 is passed through the photosensitive resin layer 31. The cured resin portion 21 can be formed on the enlarged cured resin portion 2 by irradiating the light beam.

The relief consisting of the cured resin part 2 and the cured resin part 21 formed in accordance with the present invention is now called the cured resin part 22 in FIG.
It can be easily understood that the relief of the present invention is stable when compared with the relief consisting of.

The above explanation has been given regarding an example in which the photosensitive resin layer is formed in two separate steps, but this can also be done in more separate steps. ~ The magnitude of the spread of transmitted light due to diffusion or scattering depends on the distance of the gap and the refractive index of the material that forms the gap.

In the present invention, one gap' means a layer having an optical effect as shown in FIG. 1, and is not necessarily intended to be a gap in the common sense sense.

A substance that satisfies this requirement must be substantially transparent to actinic light. Further, in order to exhibit the effects of the present invention well, it is necessary to select K such that the refractive index of the material filling the gap is smaller than the refractive index of the material constituting the transparent image body or the modified transparent image body.

The substances dripping into the gap include gaseous substances such as oxygen, nitrogen, carbon dioxide, and air; liquid substances such as water, low molecular weight hydrocarbons, and alcohol; and solid substances such as polyethylene and polypropylene. A material is chosen that does not dissolve or mix with the previous photopolymer. Gaseous substances are preferred, and gases containing oxygen gas are particularly preferred. This is because most photosensitive resins are anaerobic, and when cured in the presence of oxygen gas, the surface becomes sticky, which results in good adhesion to the cured part of the next coating as described above.

Further, the required gap distance varies depending on the refractive index of the material filling the gap.

Therefore, the refractive index n of the substance constituting the transparent image body.

The product of the ratio of the refractive index n of the material filling the gap to the distance A (W) of the gap, 111M, must be within a certain range.

For example, in the case where relief is formed in two stages as shown in FIG. 2, the value of the product is 110 from Q and S,
Preferably (L75 to 7.5).The person's value must be determined so that the M value is within this range.

That is, 0.5 X-<A(s s x shin,
n.

Preferably 0.75 X-<A<7.5X-
n, n goose.

For example, if the above-mentioned transparent image body or transparent body is a negative film with polyester as a paste, and the substance filling Seki 11 is air, H, = l, 5°nt = 1.0, so the range where the gap can be taken is Ha, a33! from 10 mm to 10 mm, preferably from 0.5 mm to 5 mm.

If this person's value is smaller than the above range, the thickness of the second relief 20 is too small and the role of the second relief 21 on top of the second relief 2 is insufficient, and the thickness of the second relief 21 due to printing pressure etc. This will cause printing problems and reduce printing durability. On the other hand, if the value of A is larger than the above range, the thickness of the first leaf 20 becomes large, so that it cannot sufficiently serve as a base, and there is a drawback that soiling of the base is likely to occur.

If the photosensitive resin layer is to be provided in multiple steps, the amount may be adjusted as appropriate according to the above concept.

In addition, when using a deformed transparent image body, 1 of the enlargement of the transparent part
It is necessary to determine the gap depending on the degree of exposure, and in some cases, exposure may be performed without a gap, so the distance of the gap cannot be determined unconditionally. The method of enlarging is fi [the transparent part may be expanded in proportion to the shape of the image, but for example, in the case of a multi-axis image or a detailed image, consider the entire solid-liquid in the desired range as an integrated transparent part, It may also be an enlarged transparent part of it. However, it is easier and preferable to use only the transparent image body to adjust the gap and form scratches without using the deformed transparent image body.

Light sources that emit active rays used in the present invention include ultraviolet fluorescent lamps, low-pressure water lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps,
Examples include a carbon arc, a xenon lamp, a metal halide lamp, etc., and it is preferable to use them as a scattered light or light source.

When carrying out the final stage exposure in the present invention, the transparent image body must be placed so as to match the position of the first stage exposure that has already been carried out. Furthermore, during the final stage exposure, the transparent image body must adhere to the resin layer in order to prevent image thickening and white spots. However, if the resin layer is in liquid form, the transparent image member can also be adhered to it through a thin sheet of polyester, cellophane, polypropylene, or the like.

As mentioned above, according to the method of the present invention, it is possible to obtain a printing order of excellent quality without deterioration of printing durability due to pressing, and in particular, it is possible to easily obtain a printing plate with a thickness of several millimeters. I can do it.

Hereinafter, the present invention will be explained in detail by giving Examples. In addition,
Parts in the examples mean parts by weight.

Example 1 Polyethylene diadipate diol (MW.

zooo) too part, ethylene oxide-propylene oxide block copolymer diol (MW.

x　o　o　o, containing 35% by weight of ethylene oxide).

26 parts of toluidine diisocyanate, Jiguchi! After reacting 13 parts of 2-hydroxyethyl methacrylate IS part at 80°C for 5 hours,
Added 0.03 parts of ido-p-quinone and reacted at 70°C for 2 hours to obtain unsaturated polyurethane = To 100 parts of this unsaturated polyurethane, 10 parts of 2-hydoxyethyl methacrylate, 10 parts of triethylene glycol dimethacrylate, Photosensitive resin (I) was prepared by mixing 10 parts of 2-acetoxyethyl methacrylate, 2 parts of benzoin ethyl ether, and 0.2 parts of p-methoxyphethol.

Next, 20 parts of snow-hydroxypropyl methacrylate was added to 100 parts of the unsaturated polyurethane.

Tetraethylene glycol dimethacrylate) 5 parts, 2-
Photosensitive resin composition 0 was prepared by blending 10 parts of 7-setoxyl methacrylate, 2 parts of benzoin ethyl ether, and 0.2 parts of p-methoxyphenol.

A polyester film (A15) provided with an anti-ration layer and an adhesive layer was placed on a horizontal steel plate, and the photosensitive resin composition prepared above (n was a doctor knife) was placed on top of it to a thickness of 2 sl. A negative film coated on a 5M glass plate was placed between the resin layer and L!15sa
A 20'W ultraviolet fluorescent lamp 1 installed with an air gap of g.
Using 0 light sources arranged in parallel [10aI from the glass surface]
After exposure for 10 minutes from a distance of After adhering to the resin layer through a polyester film, a 10 m long flat glass plate was layered on top of the polyester film, and exposed for 15 minutes with an ultraviolet fluorescent lamp.
The uncured resin was dissolved and removed with an aqueous solution of 1,0-caseinida at 0°C to obtain a print *t# with a relief thickness of 4 m and a relief thickness of 3.85 dew. When this printing plate was used to print on kraft paper, clear prints were obtained with no scuffing.

Example 2 Polyisopropylene rubber (Nippon Synthetic Rubber Co., Ltd. % formula % L2-polybutadiene (Nippon Synthetic Rubber Co., Ltd. product rJ
8RRB 51oJ) lo o part was placed in a heatable kneader and mixed at 100°C for 1 hour, then 20 parts of neopentyl glybur dimethacrylate, 2 parts of benzoin ethyl ether, and 0.1 part of p-methoxyphenol were added. Mixed for 15 minutes. The uniformly mixed composition is 1
A photosensitive resin sheet with a thickness of 15 m was produced using a press at a pressure of 0 to 50 kI/- and a temperature of 140 to 150°C.

Next, a 100μ polyester film was placed on a horizontally placed glass plate, and the photosensitive resin composition ■ prepared in Example 1 was put on it to a thickness of 3μ, and the negative film of the original was placed on the resin surface. It was set with an air gap so that IsM was established between the two. The polyester film side was exposed for 1 minute using a 15 W, 10 line, 10' csa ultraviolet fluorescent lamp, then exposed for 3 minutes using a 2 kW ultra-high pressure mercury lamp at a distance of 50 scratches from the negative film side, and then the negative film was removed and the film was exposed as described above. A photosensitive resin sheet having a thickness of L5 m was laminated on the exposed resin layer, and the negative film was brought into close contact with the film in a vacuum printing frame and exposed for 5 minutes from a distance of 100 m using a 2 kll ultra-high pressure mercury lamp. After exposure, remove the negative film and
When chlorocene was sprayed onto the plate surface for 7 minutes at a pressure of 9/d and the polyester film on the back side was peeled off, the entire resin layer was approximately L5 m111. A printing plate with a relief portion of about 3 stories and a total thickness of 4 Sm was obtained. The mark 1N1kl on the obtained printing plate faithfully reproduced the manuscript.

Example 3 A polyester film substrate having a thickness of KCL1 was placed on a surface plate, and the photosensitive resin composition (I) obtained in Example 1 was placed on it.
After coating with a thickness αS wx K doctor knife,
UV irradiation was performed. During the 105th turn of the resin layer, curing did not proceed due to oxygen, but the resin at the bottom was completely solidified. After laminating the photosensitive resin sheet obtained in Example 2 and having a thickness of L5 to this resin layer, a toluene solution containing 1% of p-quinone was applied to this laminate using a 7-bar coater. The weight increase of this laminate after toluene evaporation is x
It was α2g per i.

A 2-set polypropylene plate and then a negative film of the original were placed on top of this laminate and irradiated with a 2 kl ultra-high pressure mercury lamp.The polypropylene plate and negative film were removed, and the photosensitive film obtained in Example 1 was placed on top of the laminate. The thickness of the resin composition is 2.
After coating with ws K and adhering a negative film through a 12μ polyester film and irradiating it with ultraviolet rays, it was dissolved and developed with chloro7ane to give a total thickness of 4. , 1 m, relief part λ5. A printing plate of m (two columns of 2iaa and L5■) was obtained.

The adhesive strength between each layer of this printing plate was strong enough to withstand printing.

Example 4 On a laminate having a cured layer of the photosensitive resin composition (2) obtained in Example 1 on the substrate, the same photosensitive resin composition (2) obtained in Example 1 was used as in Example 1. A printed version was created using the same method.

The obtained printing plate has a support portion having a thickness of 2fi, a relief portion serving as an intermediate base having a thickness of 3.1111°, and a relief portion on the uppermost level having a thickness of 2 and a total thickness of 7fi.

The gap during relief exposure, which serves as the intermediate base, is an air layer 211
11, but from the cross section of the printing plate, the middle base relief was approximately 3 m longer at the interface with the top relief. Therefore, the top relief of this printing plate is in the shape of a base that is approximately three times larger around the circumference.

Example 5 151 from the photosensitive resin composition obtained in Example 2
A photosensitive resin sheet having a thickness of 111 mm was produced.

A masking film with a simple design was created by copying the transparent parts of the original negative film, including the nine characters, onto a split film (manufactured by Kimoto Co., Ltd.).

Next, add a toluene solution containing 1% hydroquinone to the parts.
The photosensitive resin sheet was coated with a tar in the same manner as in Example 3. After the toluene has completely evaporated, a water dam with a depth of 15 m is made on the hydroquinone-treated side of this sheet, and a pre-prepared masking film is placed on this water surface so as not to contain air bubbles, and the masking film is placed at a distance of 50 meters from this masking side. , and irradiated with a 2 kW ultra-high pressure water chain lamp with an exposure time of 3 minutes.

After that, the water from the dam was removed and the sheet was dried. The photosensitive resin composition (2) prepared in Example 1 was then coated on the sheet to a thickness of 2M, and the original negative film was placed on the sheet through a 12μ polyester film. - After being brought into close contact with the resin layer, it was exposed to the above light source for 5 minutes. After exposure, when xylene is blown for 10 minutes at a pressure of 2 kg/-, the support part becomes about 1. s
m.

The thickness of the relief part forming the middle base was approximately 2 cm, and the top relief was 21111 cm, with a total thickness of 5 cm. When printing using this plate, clear printed matter was obtained without causing background stains.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle when exposing with a gap, and FIG. 2 is a diagram showing the principle when a relief is finally formed following FIG. 1. FIG. 3 is a diagram showing the principle of a normal relief forming method. Procedural amendment dated September 9, 1981, Director General of the Patent Office 1, Indication of the case, Patent Application No. 1983-127682 2, Name of the invention, Exposure method 3, Relationship with the W-correction case Patent applicant 1-11 Minamihonmachi, Higashi-ku, Osaka (300) Teijin Ltd. Representative Tomoo Tokusue 5, Subject of amendment (1) In the 3rd line from the bottom of page 11 of the specification, the word “tacky” has been replaced with “uncured.” (2) Correct "Scattered light, light source" in the 11th line from the top of No. 141R to "Scattered light source." (3) “Photosensitive resin (
T)" is corrected to "Photosensitive resin composition (I)." (4) “Photosensitive resin (
(2)" is corrected to "Photosensitive resin composition (n)." (5) "Split film (Kimoto Co., Ltd. product)" in the 11th line from just below No. 21 is corrected to "Strip coat (Kimoto Co., Ltd. product)". Written amendment to the above procedure March 7, 1980 Mr. Commissioner of the Japan Patent Office 1. Indication of the case/Patent Application No. 127682/Sho '6-127682 2. Name of the invention Exposure method 3. Person making the amendment Relationship with the case Patent applicant 1-11 Minamihonmachi, Higashi-ku, Osaka (c3oo) Teijin Co., Ltd. Representative Tomo Tokusue Teijin Co., Ltd. 5, subject to correction / 1st day Hana 2aki / 3 times

Claims (1)

[Claims] L In an exposure method in which actinic rays are irradiated from the surface of a photosensitive resin layer provided on a support through a transparent 15g MII body to form a cured resin portion corresponding to the transparent portion; (1 ) The photosensitive resin layer is applied twice or more, and the photosensitive resin layer applied at least the first time is coated with the transparent image body and the photosensitive resin layer through the transparent body. irradiate actinic rays with a gap between the surface of the photosensitive resin layer, or
Actinic rays are irradiated through the image body Ii, with a gap between the deformed transparent image body and the surface of the photosensitive resin layer, or at the same time. An exposure method characterized by irradiating actinic light through the transparent image body with substantially no gap between the transparent image body and the surface of the photosensitive resin layer.