JPS6012622B2 - Polyamide photosensitive resin printing plate composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid state photosensitive resin composition containing soluble nylon as a shape-retaining component (also referred to as a binding component of the composition), and particularly relates to a solid state photosensitive resin composition for forming a printing plate material for letterpress printing. The present invention provides a composition for a photosensitive resin printing plate.

The photosensitive resin printing plate composition is closely formed as a sheet-like material of a certain thickness on a suitable base material and supplied to a plate making company. At plate makers, a negative film carrying an image is placed on top of it and exposed and printed.
A photopolymerization reaction occurs, converting the exposed area to solvent insolubility,
Next, there is development, and in an operation called washing out, the composition in the unexposed areas is dissolved and removed with an alcohol solvent, etc.
A negative, faithful leaf image is formed on a substrate and subjected to printing operations. The printing plates used in so-called letterpress printing have long been mainly type and metal corrosion plates, but recently, reflecting various environmental and economic requirements, the use of resin has progressed.

By using a resin composition for relief formation, in addition to the combination with a metal base material, a transparent letterpress material based on a resin film has appeared, offering various advantages that could not be obtained with type or metal corrosion plates. discovered. That is, the plate can be easily made into a cylindrical shape and is maneuverable, and since the plate is transparent, it is very easy to set the plate on the plate chest. These features, combined with the good abrasion resistance that is a feature of nylon resin, make it useful in business form printing, which often requires a very large number of runs, especially in the field of rotary letterpress printing. . The field of letterpress printing is a field that takes advantage of the features and advantages of letterpress printing.
In addition to the majority of newspaper printing, it also produces a large amount of printed matter in general commercial printing.

A wide variety of photosensitive resin letterpress materials are already commercially available for use in letterpress printing. Broadly speaking, they can be divided into those that are manufactured in a factory in the form of a solid plate, and require only two steps at the plate making company to achieve the desired size: exposure and washing, and those that are made of liquid photosensitive resin. In some cases, the manufacturer supplies the material and accompanying materials for plate making, and the plate making company uses specific plate making equipment to form a sheet-like plate material and performs exposure and washing to create a printing plate. . In the latter method, due to problems with the plate-making equipment, the plate-making size is not arbitrary, and in some cases it may be necessary to use more resin and materials than necessary, and the reproducibility of fine images may be affected by It may be inferior to other printing materials. When printing plates for business forms, there are many forms with high dimensional accuracy, and in order to perform rotary letterpress printing on them, it is necessary to print them in a curved shape.

With liquid compositions, it is impossible to print curved surfaces, and it is necessary to use special technology to make corrections in advance at the negative film creation stage, which requires extra labor and cost. Become. It has already been recognized that letterpress materials obtained from compositions using nylon as a solid state-retaining component are excellent in image reproduction performance, printing durability, and resistance to counterfeiting.

In comparison, those in which a plate material is formed from a liquid composition may be inferior in image reproduction performance, printing durability, forgery resistance, and the like. However, some plate materials made from these liquid compositions have a relatively low hardness in the relief portion after curing, and therefore, from the point of view of ink receptivity, the solid state photosensitive resin composition is rather hard. There are some materials that give better results than those obtained from commercially available materials. It was originally promoted with the idea of replacing type and metal corroded plates with resin compositions, so harder photosensitive resin letterpress materials were accepted as suitable, but printing plates With the new form of printing, the development of printing on new objects progressed in an unconventional direction.
There has been a demand for a composition for a solid state photosensitive resin printing plate that has good ink receptivity, that is, has a slightly reduced hardness. Against this background, the present invention aims to develop a composition that is more flexible and has superior properties to conventional nylon resin letterpress materials.

Many attempts have already been made to obtain flexible letterpress materials.

One of these is the addition of plasticizers to printing plate compositions. This is a common method for improving the processability and visibility of resins, but it requires the addition of a fairly large amount of plasticizer to achieve the desired hardness, and there are problems with compatibility with the resin. Even if this problem could be solved by some method, the presence of a large amount of plasticizer would cause a problem in that the image reproduction performance would deteriorate. Other attempts to obtain flexible relief materials have been made by using flexible polymers as binding components. A typical example is the use of N-alkoxymethylated nylon, but even in this case there are problems in terms of balance with ink receptivity, image reproducibility, printing durability, etc., and it is also cost-effective. The songs are lacking. The present inventor has determined the problems of the prior art as described above, and as a result of intensive study, has found that the object of the present invention can be achieved by the present invention described below,
I put it out. That is, the present invention provides a field-state photosensitive resin printing plate composition containing a soluble polyamide and a photo-insolubilizable unsaturated monomer as main components, in which the weight ratio of the polyamide to the photo-insolubilizable unsaturated monomer is from 0.4 to 0.4. 1.5, the photo-insolubilized unsaturated mole is a monofunctional acrylic acid ester derivative represented by the following general formula [1], and C=CH-CO-Xf
Y) n [1] (x is a polyester or monoester residue having an ester structure obtained by the reaction of a polyhydric alcohol and a polybasic acid, n is an integer of 1 to 3, Y is a hydroxyl group or a carpoxyl group .

When n is 2 or 3, Y may be the same or different. ) A cured composition obtained by applying a sufficient exposure amount to form a relief image on the composition has a tensile modulus of 10k9' or less after being left for 5 days under conditions of 2yo and 50% relative humidity. A composition for a polyamide-based photosensitive resin printing plate, characterized in that:

The soluble polyamide used in the present invention is a polyamide that has high solubility in solvents, particularly lower alcohols, and is specifically synthesized from dibasic fatty acids, diamines, -amino acids, lactams, or derivatives thereof by known methods. Not only homopolymers, but also copolymers, block polymers, etc. can be used. A polyamide having a substituent on a carbon atom or a nitrogen atom constituting the primary mirror may also be used, and a polyamide containing bonds other than C1C and 1C-N-CO- bonds in the main chain may also be used. Typical examples are nylon 3, 4, 5,
6.8.11.12.13.6.6.6.10.13.
13. Polyamide from metaxylylene diamine and adipic acid, trimethylhexamethylene diamine, or polyamide from isophorone diamine and adipic acid, or copolyamide containing these components, caprolactam/adipic acid/hexamethylene diamine/4・4
'-diaminodicyclohexylmethane copolyamide and their N-methylol and N-alkoxymethyl derivatives can also be used. The polyamide that can be used in the method of the present invention is not limited to a single polyamide, and may be a mixture of two or more polyamides. The photoinsolubilized unsaturated monomer used in the present invention is mainly a monofunctional acrylic acid ester derivative having a hydroxyl group or a carboxyl group, and in particular has a boiling point of 200°C or higher at normal pressure,
The following general formula [1] having one acryloyl group in the molecule
It is a compound represented by C is =CH-CO-XfY
) n[1] (X is a polyester or monoester residue having an ester structure obtained by the reaction of a polyhydric alcohol and a polybasic acid, n' is an integer from 1 to 3, and Y is a hydroxyl group or a carboxyl group .

When n is 2 or 3, Y may be the same or different. ) The mo/ma of [1] above is the following [a} to [d
} and other methods.

An acrylate having a ta-hydroxyl group is reacted with a polybasic acid anhydride.

'b - React an acrylate with an epoxy group with a monobasic acid or a polybasic acid.

'c- React an acrylate with a carboxyl group and a monoepoxide.

'd} A mixture of acrylic acid and polybasic acid anhydride is reacted with monoepoxide.

Examples of compounds that can be synthesized by such a reaction and used in the present invention are as follows.

Maleic acid monoacryloyloxyethyl ester, maleic acid monoacryloyloxyisopropyl ester, succinic acid monoacryloyloxyethyl ester,
Succinic acid monoacryloyloxyisopropyl ester, phthalic acid monoacryloyloxyethyl ester,
Monoacrylate of polyester diol with phthalic acid and propylene glycol, monoacrylate of polyester diol with maleic acid and propylene glycol,
Monoacrylate of polyester diol with hexahydrophthalic acid and propylene glycol, monoacrylate of polyester diol with succinic acid and propylene glycol, monoacrylate of polyester diol with maleic acid and ethylene glycol and glycerin-diphenyl ether, Monoacrylate of polyester diol of tetrahydrophthalic acid, propylene glycol, and glycerate butyl ether, monofunctional acrylate ester derivatives of these can be used alone or in combination of two or more. .

The weight ratio of the polyamide and the photo-insolubilizable unsaturated monomer is 0.4 to 1.5, preferably 0.5 to 1.0.

This ratio is 0.5 or less, especially 0. When the composition reaches its final stage, the surface of the composition becomes sticky, and when used as a printing plate, the negative film will stick strongly to the surface. In terms of work, complete adhesion is hindered and unnecessary effort is required to remove the negative film. For this reason, the film surface of the negative film is often damaged, and favorable results cannot be obtained. If it is 1.0 or more, especially 1.5 or more, it will not be possible to sufficiently reduce the hardness that is the object of the present invention, and it will not be possible to obtain a sufficiently satisfactory relief image. The composition of the present invention may also contain, as a minor component, acrylate and methacrylate derivatives used in the art having difunctional or more reactive groups.

Examples of the polyfunctional (meth)acrylate compounds that can be used include, but are not limited to, the following. Ethylene glycol di(meth)acrylate diethylene glycol di(meth)acrylate triethylene glycol di(meth)acrylate polyethylene glycol #200 di(meth)acrylate polyethylene glycol #400 di(meth)acrylate polyethylene glycol #600 di(meth)acrylate 1. 3
-Butylene glycol di(meth)acrylate 1,4-
Butylene glycol di(meth)acrylate 1,6-hexane glycol di(meth)acrylate Neobentyl glycol di(meth)acrylate Dipropylene glycol di(meth)acrylate Polypropylene glycol di(meth)acrylate 2,2-bis(4) (meth)acryloxydiethoxyphenyl)propanetrimethylolpropanetri(meth)acrylatetrimethylolethanetri(meth)acrylatetetramethylolmethanetriacrylatetetramethylolmethanetetraacrylatedibromneobentylglycoldi(meth)acrylatesorbitol Tri(meth)acrylate Sorbitol Di(meth)acrylate Polyester(meth)acrylates Epoxy(meth)acrylates In order to make a composition containing the above-exemplified polyamide and a monomer or a monomer mixture photosensitized, it is necessary to make it photosensitive. A photoinitiator or photosensitizer is added to initiate the polymerization reaction.

As a photopolymerization initiator, (i' carbonyl compound - pendyl, benzoin alkyl ether, diacetyl, benzophenone, Micher's ketone, acetophenone, benzoin silyl ether, etc.), (li) peroxide, (i
ii) Azo compounds - azobisisobutyronitrile, azodibenzoyl, azo-2,4-dimethyl-4-methoxyvaleronitrile, etc., 0 sulfur compounds - dibenzothiazolyl sulfide, hydroxyxanthate group, etc. M halides - CBr, etc., M redox systems - iron salts, photoreducible dyes, etc., Nih hydrogen abstraction systems,
There is an iD inorganic compound system. It is important to add an appropriate amount of photopolymerization initiator that is compatible with the characteristics of the reactive monomer used and the properties of the composition, and its selection can be easily determined by experiment. In addition to the above, thermal polymerization inhibitors, plasticizers, beam pigments, and the like can also be appropriately added to the composition of the present invention.

The composition of the present invention consisting of each of the above components must further satisfy the following requirements.

That is, the tensile modulus of the cured composition obtained by giving the composition an exposure amount sufficient to form a relief image after being left for 5 days under conditions of 2yo and 50% relative humidity is 10k9/g or less. The requirement is that The lower limit of the tensile modulus depends on the purpose of use, but is generally 0.5k9/
It's about the same level as Hiro. By satisfying these requirements, a plate that fits well onto the plate cylinder can be obtained. Conventionally, it has been empirically known that the hardness of the printing plate is dominant in ink transferability to printing paper, but the present inventors have found that ink transferability is more strongly dependent on the tensile modulus of the printing plate. I found out what I was doing.

That is, even if the Shore D hardness of the printing plate is approximately the same, the lower the tensile modulus of elasticity, the better the ink transferability. The reason for this is presumed to be that the ink transferability becomes better as the printing plate surface is more easily deformed in response to the unevenness of the paper surface. The tensile modulus is considered to be the most direct physical property value that indicates the ease with which a printing plate deforms. For this reason, there is a close relationship between the ink transferability and the tensile modulus of the printing plate, and in particular, when the tensile modulus becomes 10 kg/kg or less, the ink transferability improves rapidly. For these reasons, the tensile modulus of the printing plate obtained from the photosensitive composition of the present invention is 1.
It is necessary that the amount is less than 0 kg/. A composition that satisfies the conditions of the present invention can be made in numerous combinations of polymers and monomers.

For example, it is possible to use very flexible polymers, but this often results in the so-called cold flow problem in which the unexposed plate material deforms even at room temperature. However, in the present invention, since a monofunctional acrylic acid ester derivative having a hydroxyl group or a carboxyl group is mainly used as a photo-resistant unsaturated monomer, the plate material after photocuring has a small tensile modulus. In other words, in general, monofunctional acrylic esters have a looser crosslinked structure formed by photopolymerization than polyfunctional acrylic esters or methacrylic esters, which are normally used for insolubilizing unsaturated monomers, so that the photocurable portion is less likely to be cured. The tensile modulus of elasticity becomes smaller.
However, the looseness of the crosslinked structure causes a significant decrease in image reproducibility, but since the monofunctional acrylic ester of the present invention has -OH groups and -COO groups in the molecule, it has poor compatibility with polyamide. Since the properties are very good, the polyamide is efficiently included in the crosslinked structure formed by photopolymerization. Therefore, it has the advantage that the deterioration in image reproducibility is extremely slight. Therefore, the tensile modulus is 10k
As a typical example of a photosensitive resin composition having a size of 9' or less and having practical image reproducibility, the polyamide of the present invention and -O
There are those whose main component is a monofunctional acrylic acid ester having H or one COO day. The photopolymerization component, various additives, and polyamide used in the present invention can be mixed by various known methods.

That is, there are methods of mixing these in a molten state, or methods of dissolving and mixing them in a solvent such as alcohol, and then removing the solvent. When applying the compositions obtained in this way to printing plates, these compositions or solutions of the compositions are molded to a thickness by known methods such as compression molding, extrusion molding, calendering, and coating methods. Use by forming into a uniform sheet. The photosensitive layer sheet is fixed to another suitable support to improve the dimensional accuracy and mechanical strength of the plate. The surface of the photosensitive layer is generally covered with a cover film mainly for protection.

Further, when a cover film with a roughened surface is used, the rough surface state is transferred to the surface of the photosensitive layer, and the surface of the photosensitive layer becomes rough. By doing so, the negative film can be easily and completely adhered to the negative film. When a smooth film is used as a cover film, it is recommended to use a matte film as the negative film, but the use of the above-mentioned paper-faced film is advantageous since it is not necessary. Such roughened films include chemically treated or sand-matted polyester films, and film-based synthetic paper made from polypropylene or polystyrene. However, the use of a cover film with a smooth surface does not diminish the object of the invention.

An image carrier film is vacuum-adhered to the surface of the photosensitive resin printing plate material thus obtained, and ultraviolet rays or light containing ultraviolet rays are irradiated from above.

As such a light source, a high-pressure or ultra-high-pressure mercury lamp, a carbon arc lamp, an ultraviolet crab light lamp, a xenon lamp, etc. are used. Since the exposed areas of the photosensitive layer become insoluble by irradiation, a relief image can be created by washing away the unexposed areas with a solvent mainly composed of lower alcohols.

To wash out the unexposed areas, a method of spraying a solvent from a spray nozzle or a method of scrubbing with a brush or the like in a solvent is used. After the washing operation, if the surface of the plate is washed and dried, a plate that can be immediately used for printing can be obtained.
A printing plate having a photosensitive layer made of the composition of the present invention has the following significant improvements.

{11 The cured photosensitive layer is flexible as a whole and has good fit to the plate cylinder.

■ The hardness of the relief image of the cured photosensitive layer is Shore D.
60 or less, and the ink receptivity is good.

Due to the characteristics of polyamide, moisture can enter and exit the cured composition depending on the outdoor conditions, but it does not become too hard even in sufficiently dry conditions, and the decrease in mechanical strength is small even in humid weather conditions, so it is not brittle. It won't happen. The reproduction performance of the relief image is sufficient for printing business forms, which is the main purpose of the plate material of the present invention. Examples will be described below. Example 1 Copolymerized nylon “U1tramidIC” manufactured by BASF
was used as a polyamide component, and monoacryloyloxyethyl succinate (Toagosei Chemical Industry ■ product, "Aronix #550") was blended with this, and to this blend, benzine sulfate was added.

A sheet material was prepared by adding 2% Pirenal as a photopolymerization initiator, and the sheet material was adhered onto a polyester film (thickness: 200 mm) to prepare a plate sample having a total thickness of about 1 sail. The evaluation results are shown in Table 1. Table 1 NO. In No. 5, it was difficult to adhere and peel off the negative film because the plate surface was sticky.

Example 2 100 parts by weight of “U1tramid IC” and “Aron”
A composition consisting of 20 parts by weight of ix #5500'' with the following sensitizer added was dissolved in ethanol (water content 10%) and placed on a polyester film (thickness 200 mm) coated with an adhesive. A sheet-like product was created by casting and drying.

The total thickness was adjusted to approximately 1 willow. A negative film with a test image was adhered to the surface of this composition sheet and exposed (for 3 minutes) using a printer "Jet Light" 2000 manufactured by Oak Seisakusho. Thereafter, development and washing were performed using a brush-type washing machine with an ethanol/water temperature mixed solvent (mixing ratio 8/2). The images were evaluated using a magnifying glass. To determine the hardness, after the exposure treatment, the base film was peeled off from the photosensitive layer, and only the photosensitive layer was left in a temperature and humidity controlled room at 2300 RH and 50% for one day. Several or more sheets were stacked to a thickness of 3 to 5 skins, and the hardness was measured using a Shore D hardness meter. The evaluation results are shown in Table 2. Table 2 Example 3 A 500 cc four-necked flask was equipped with a condensation rod, a reflux condenser, and a thermometer, and a mixture of ethanol/water = 85/15 was prepared at 150 ml.
Add evening.

Add "Umamid I〇'90" and heat it under reflux to completely dissolve it. Add "Amn" to this nylon solution.
ix #550 and 110, glycidyl methacrylate 4
molecule and one molecule of xylylenediamine (GX
), and pentaerythritol triacrylate (Shin-Nakamura Chemical Co., Ltd. "NK Estenozo A-TMM3") were used as a monomer mixture (nylon monomer weight ratio approximately 0.75).
), to which 0.1% of 2-methylanthraquinone was added. This solution was cast onto a polyester film coated with adhesive to form a sheet and dried. The total thickness was about 1 rib. After drying, a chemical matte-treated polyester film ("LumiPearl") was adhered to the surface through a thin coating of alcohol solvent. One week after formation, exposure and development were performed. A sharp image was obtained, and the depth of the white areas was sufficient.

After drying the cured product (5000, 24 hr), 2yC, RH
The hardness of the composition after being left at 50% for 10 days was 50 (Shore D). The initial elastic modulus obtained in the tensile test is
It was 8.5k9/fence. In addition, this composition does not contain any stabilizers other than the thermal polymerization inhibitor contained in the unsaturated monomer used, but it has very good stability during storage and even under high humidity conditions. , no phenomena such as monomer seepage occurred. Example 4 Same as in Example 3, the amount of "mtramid" used was 80 mm, and the weight ratio of nylon/monomer was 0.
67 was prepared.

Monoma released “AJonix #5500” on the 106th, GX
On the 4th evening, I used 10 tons of A-TMM-3. With this composition as well, an excellent relief image was obtained and the hardness was Shore D48.

The tensile modulus was 7.3k9/h. Example 5 The weight ratio of "U1tramidI〇' and monomer is 0.8
3, a reaction product of monofunctional acrylate in the monomer, one molecule of propylene glycol diglycidyl ether, which is a polyfunctional monomer, and two molecules of acrylic acid (abbreviated as PA)
The results are shown below when the weight ratio was changed between 5/1 and 2/1.

As a sensitizer, 0.5% of 2-methylanthraquinone was added. The Shore D hardness and tensile modulus of the exposed and cured compositions are shown in Table 3. Table 3 Example 6 Table 4 shows the results when monofunctional Aronix #550 and PA used in Example 5 were used at a weight ratio of 3/1 as monomers, and the blending ratio with nylon was varied. It was as follows.

0.5% of 2-methylanthraquinone was used as a sensitizer. Table 4 was used as the monofunctional monomer component.

No. “Aronix #5500” at a blending ratio of 14
A printing plate was prepared using a composition in which ``'' was replaced with ``Amnix #570.'' Exposure and development were carried out in a conventional manner to obtain a printing plate with a sharp image. When an ink receptivity test was conducted using a letterpress proofing machine under the same conditions as a resin plate with hardness of Shore D67, it was observed that there was a clear difference in print density at low printing pressure.Example 9 “〜oni” is an acrylic oligoester.
A composition was prepared using x#5700'' (Toagosei ■ product) as a monofunctional monomer at the following blending ratio.

BASF “U1tramidI〇’”
10 Foundation ''~Plate iX#5700''
8 anchor ethylene glycol diacrylate
2 Ikarito Trietanolamine 5
3 parts Penzophenone 3 parts This composition was formed into a sheet by a conventional method. Example 7 Amilan CM400 manufactured by Torayan was used as the nylon component, and monoacryloyloxyethyl phthalate was used as the monofunctional monomer. It was used.

The weight ratio of both was about 0.67, and 0.3% of 2-methylanthraquinone was used as a sensitizer. “Aronix#55
A more flexible cured composition was obtained than when using 00''. Two parts of the GX mentioned above are added to this system, and A-TM
When 5 parts of M-3 was added to form a relief image, sharper image edges were obtained. Example 8 A plate material was obtained from "Fonix #570" (structural formula: manufactured by Toagosei), which is an acrylic oligoester monomer having a hydroxyl group.

Exposure and development in the usual manner gave a printing plate with a highly sharp image. Dry the photocured product (5000
, 24 hours), the hardness after being left at 23oo and RH50% for 10 days was Shore D45. Example 10 In Example 7, monoacryloyloxyethyl maleate was used instead of monoacryloyloxyethyl phthalate.

The printing plate obtained using this photosensitive composition was heated at 23°CRH.
After being left at 50% for 10 days, the hardness was Shore D50 and the tensile modulus was 8.0k9/Iso. As a result of printing tests, good ink transfer properties were obtained. Example 11 In Example 9, instead of “Amnix''5700,
B-hydroxyethyl-8'-acryloyloxyethyl phthalate having the following structural formula was used.

After the obtained printing plate was left for 10 days at 23oORH50%, the hardness was Shore D42, and the tensile modulus was 4.0.
It was k9'.

Claims (1)

[Claims] 1. A solid photosensitive resin printing plate composition containing a soluble polyamide and a photoinsolubilizable unsaturated monomer as main components,
The weight ratio of polyamide and photoinsolubilized unsaturated monomer is 0.4
~1.5, the photoinsolubilized unsaturated monomer is a monofunctional acrylic ester derivative represented by the following general formula [I], and CH_2=CH-CO-X-(Y)_n[I](
X is a polyester or monoester residue having an ester structure obtained by the reaction of a polyhydric alcohol and a polybasic acid, n is an integer of 1 to 3, and Y is a hydroxyl group or a carboxyl group. When n is 2 or 3, Y may be the same or different. ) A cured composition obtained by giving a sufficient exposure amount to form a relief image on the composition has a tensile modulus of 10 kg/mm^ after being left for 5 days at 23°C and 50% relative humidity. 1. A composition for a polyamide photosensitive resin printing plate, characterized in that the polyamide photosensitive resin printing plate composition has a molecular weight of 2 or less.