JPH0229681B2 - HIKARIJUGOSE ISOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photopolymerizable composition,
In particular, it has extremely high sensitivity to visible light,
The present invention relates to a photopolymerizable composition that is also suitable for image formation using a visible light laser, such as an argon ion laser. Conventionally, a compound having at least one ethylenically unsaturated bond capable of addition polymerization is mixed with a photopolymerization initiator, and if necessary, an organic polymer substance with film-forming ability, a thermal polymerization inhibitor, etc. The method of copying images using a composition and photographic techniques is well known and is widely used, for example, in photosensitive resin printing plates, photoresists, and the like. In this method, conventional photopolymerization initiators include benzoin, benzyl, benzophenone,
Anthraquinone, Michler's ketone, etc. have been used, but each of these photopolymerization initiators has a problem in that they are sensitive to relatively short wavelength ultraviolet rays but are hardly sensitive to long wavelength visible light. The ability to use visible light as a light source for image formation and curing of coatings is extremely desirable and has been desired for a long time, especially with the recent development of scanning exposure technology using laser beams.
There is a strong desire for the development of a photosensitive material that is highly sensitive to visible laser light such as an argon laser. Photopolymerization initiators sensitive to visible light (wavelength 400nm to 700nm) include various dyes,
Combinations of dyes and other compounds have been proposed. It is known that the photopolymerization initiation effect is significantly increased when dyes are combined with certain appropriate reducing substances.
For example, combinations such as methylene blue-triethanolamine and eosin-ascorbic acid have already been reported. However, these known visible light polymerization initiator systems have a number of drawbacks. That is, these generally do not have sufficient sensitivity and require a large amount of light energy to cause photopolymerization, and recording by laser beam scanning exposure is either impossible, or even if it is possible, the output is quite high. It requires several lasers and is not economical. Furthermore, photoinitiators that provide relatively high sensitivity are generally specialized and expensive compounds. In view of this situation, the inventor of the present invention has conducted intensive studies on light-sensitive materials that are extremely sensitive to visible light and are inexpensive. The inventors have discovered that when a combination of these substances is used as a photopolymerization initiator, it exhibits surprisingly high sensitivity to visible light, leading to the present invention. That is, the present invention provides a photopolymerizable composition comprising an addition polymerizable compound having at least one ethylenically unsaturated bond and a photopolymerization initiator, wherein the photopolymerization initiator has (a) the following general formula [] Compound represented by (In the formula, M ₁ is a hydrogen atom or an alkali metal, M ₂
is a hydrogen atom, an alkali metal, an ammonium group,
a substituted ammonium group or an alkyl group,
X ₁ to _{X 8} are halogen atoms, hydrogen atoms, or monovalent organic or inorganic residues, and at least one of them is a halogen atom. ) and (b) a compound represented by the following general formula [] (In the formula, Ar is a monovalent or divalent aromatic residue (which may have a substituent such as an alkyl group), R ₁ to _{R 4}
is an alkyl group, substituted alkyl group, or aryl group, which can also be part of the side chain or main chain of the polymer. n is 0 or 1. ) The present invention relates to a photopolymerizable composition characterized in that it is a combination of the following. Each component constituting the photopolymerizable composition of the present invention will be described below. In the photopolymerizable composition of the present invention, the addition-polymerizable compound having at least one ethylenically unsaturated bond (hereinafter referred to as an ethylenic compound), which is the first component, includes other compounds in the composition. There are no particular restrictions on the structure or molecular weight as long as the photopolymerizable composition is compatible with the components of When used as such, it is preferable to use one having a boiling point of about 100° C. or higher under atmospheric pressure. Specific examples of such substances include (meth)acrylic esters of polyhydric alcohols, such as glycerin mono(meth)acrylate, glycerin di(meth)acrylate,
Acrylate, diethylene glycol mono(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, etc., or epoxy compounds and (meth)acrylate An addition reaction product of acrylic acid, an addition reaction product of a compound having a carboxyl group and glycidyl (meth)acrylate, an acrylamide-based compound such as (meth)acrylamide, methylenebis(meth)acrylamide, triacryl formal, etc., or containing a hydroxyl group Examples include unsaturated urethane compounds obtained by addition reaction between ethylenically unsaturated compounds and isocyanates. These compounds may be used alone or in combination of two or more. Next, the photopolymerization initiator component, which is a significant feature of the present invention, will be explained. The photopolymerization initiator of the present invention consists of two components (a) and (b), and the (a) component absorbs light (especially visible light with a wavelength of 400 nm or more) and decomposes when irradiated with active light. is a component that generates radicals and reacts with the ethylenic compound in the photopolymerizable composition to initiate addition polymerization of the ethylenic compound, and component (b) is the component (a) described above.
It is a component that promotes the photodecomposition reaction of components and, as a result, significantly increases the photosensitivity of the photopolymerizable composition. Component (a) is a compound represented by the general formula [], and this compound is usually used as a pigment,
It contains many substances that are well-known, for example as dyes or pharmaceuticals, and are easily and inexpensively available. Examples of such compounds include eosin Y,
These include erythrosine, diiodofluorescein, dibromefluorescein, rose bengal, and markyurochrome. Among these, erythrosin or eosin Y is particularly preferred. Component (b) is a compound represented by the general formula []. R ₁ to _{R 4} in the general formula are alkyl, substituted alkyl, or aryl groups, and among these, particularly preferred are hydroxy-substituted alkyl, substituted alkyl having a hydroxy group and other substituents, and arylmethyl. Many of the compounds having these groups are additives of primary or secondary arylmethylamines and epoxy compounds such as ethylene oxide, propylene oxide, glycidol, alkyl glycidyl ethers, aryl glycidyl ethers, carboxylic acid glycidyl esters, etc. It can be easily synthesized by reaction. Examples of such compounds include tribenzylamine, N,N-dibenzylethanolamine, N,
N-diverzylpropanolamine, N-(2,
3-dihydroxypropyl)dibenzylamine,
N-(2-hydroxy-3-phenoxypropyl)
Dibenzylamine, N-(2-hydroxy-3-
butoxypropyl)dibenzylamine, N,N-
bis(2-hydroxyethyl)benzylamine,
N,N-bis(2,3-dihydroxypropyl)
Benzylamine, N-methyl-N-benzylethanolamine, N-methyl-N-(2,3-dihydroxypropyl)benzylamine, N,N,
N',N'-tetrakis(2-hydroxyethyl)
Examples thereof include xylylene diamine, N,N,N',N'-tetrakis(2,3-dihydroxypropyl)xylylene diamine, and the like. Although it is possible to obtain a certain degree of photosensitivity by using other tertiary amines, such as triethanolamine, in place of these compounds, the photosensitivity is insufficient. Exceptionally high photosensitivity can be obtained only when an aminated compound is used. As component (b), in addition to the low-molecular substances exemplified above, polymeric substances can also be used, and in that case, film-forming properties can be imparted to the composition without adding any other polymeric binder. Can be granted. Examples of methods for producing the polymeric component (b) include the following methods. (i) A secondary amine is subjected to a condensation reaction with a polymer having a halogenomethylphenyl group in a side chain. (ii) An unsaturated addition reaction product obtained by adding glycidyl (meth)acrylate to a secondary amine containing a benzyl group is (co)polymerized. (iii) A secondary amine containing a benzyl group is reacted with a polymer having a functional group in its side chain that can react with an amino group such as an epoxy group. (iv) 1 mole of N,N'-disubstituted xylylenediamine is reacted with 1 mole of a compound having two functional groups capable of reacting with amino groups such as epoxy groups, and a high Molecularize. The photopolymerization initiator contained in the photopolymerizable composition of the present invention and having a remarkable feature is a combination of components (a) and (b) as described above. Each of these substances may be used alone, but it is also possible to use two substances.
It is also possible to use a mixture of more than one species. Furthermore, the weight ratio of the combination in which the effects of the present invention are particularly prominently exhibited is in the range of the ratio of compound (a) to (b) from about 5:1 to about 1:100, preferably about 1:1. From about 1:
Ranges up to 50. The amount of the photopolymerization initiator in the photopolymerizable composition of the present invention is from 0.01% to 20% by weight based on the total amount of the compound of component (a), the ethylenic compound and, if necessary, the organic polymeric binder. The appropriate range is up to
More preferably, it is in the range of 0.1% to 5% by weight. If the amount of component (a) is less than this range, the photopolymerizability of the composition will be significantly reduced because the amount of radicals that initiate polymerization of the ethylenic compound when irradiated with actinic light will be small. Furthermore, if an excessive amount exceeding the above range is used, the photosensitivity decreases due to effects such as blocking of effective light. Component (b) is added to component (a) in an amount within the aforementioned ratio range, but 50% by weight relative to the total composition.
Exceeding this is not preferable because it will adversely affect the physical properties of the cured composition. However, this is not the case when component (b) contains a polymer that also serves as a binder, and it can also be contained in an amount of up to about 90% by weight based on the total amount of the composition. The photopolymerizable composition of the present invention is a mixture whose essential components are an ethylenic compound and a photopolymerization initiator consisting of two components (a) and (b), as described above. In order to impart film-forming ability to
An organic polymer substance that is compatible with the above-mentioned essential components and has a film-forming ability can be contained in the photopolymerizable composition as a binder. For many uses such as presensitized printing plates (PS plates) and photoresists, it is preferable to use such a binder substance in combination to impart film-forming ability to the photopolymerizable composition. Any polymeric substance may be used as long as it is soluble in the solvent and compatible with the ethylenic compound and the photopolymerization initiator component, but particularly preferred are water, water, Alternatively, it is a polymeric substance that is soluble in aqueous solutions such as alkali and acid, and therefore can be developed with an aqueous developer. Furthermore, in order to obtain particularly high sensitivity, it is preferable to use a polymer having a polymerizable unsaturated group in the side chain. Examples of such polymers include addition polymers having carboxyl groups in the side chains, such as polymers obtained by adding glycidyl (meth)acrylate to (co)polymers such as (meth)acrylic acid and maleic acid; Polymers having epoxy groups such as glycidyl (meth)acrylate (co)polymers, epoxy novolac resins and the like with (meth)acrylic acid added to them, and diols having unsaturated groups and diisocyanates. There are polyurethanes obtained by heavy addition. Other soluble polymers without unsaturated groups such as copolymerized nylon, polyvinyl alcohol/(meth)acrylic acid ester, (meth)acrylic acid copolymer, styrene/(meth)acrylic acid copolymer, styrene/maleic acid copolymer Polymer, (meth)acrylic acid ester/(meth)
Acrylamide copolymers and the like can be used similarly. These polymeric substances may be used alone or in combination of two or more in an appropriate ratio. When the above-mentioned polymeric substances are contained as a binder in the photopolymerizable composition of the present invention, the range in which good image or cured film characteristics can be provided may vary depending on the type of the polymeric substance, but in general, the photopolymerizable composition of the present invention It is preferably contained in a range of about 10% to 90% by weight, more preferably in a range of about 30% to about 80% by weight, based on the total weight of the polymerizable composition. In addition, when using a polymer having no unsaturated groups as a binder, it is preferable to contain at least one polymer having two or more unsaturated groups as the ethylenic compound component. When using a polymer having one unsaturated group, the ethylenic compound component may have only one unsaturated group, and in fact, higher sensitivity can be obtained in this case. Since a polymer having an unsaturated side chain can itself be regarded as an ethylenic compound component, when the polymer itself is used as a binder, it is not necessarily necessary to add a low-molecular ethylenic compound. However, even in that case, it is advantageous to contain a low molecular weight ethylenic compound in order to obtain high sensitivity. Additives such as a thermal polymerization inhibitor, a photopolymerization accelerator, an adhesion improver, and a development accelerator can be added to the photopolymerizable composition of the present invention, if necessary. A thermal polymerization inhibitor is a substance that has the function of preventing unnecessary thermal polymerization during storage of a photopolymerizable composition and improving stability over time. Specific examples thereof include soluble nitrite, hydroquinone, benzoquinone, and
-methoxyphenol, t-butylcatechol,
Examples include phenothiazine and N-nitrosodiphenylamine. The amount of these substances added varies considerably depending on the type, but is generally from 0.01% to about 5% by weight, preferably about 5% by weight based on the ethylenic compound.
It ranges from 0.05% to about 3%. The photopolymerization initiator is a substance that has the effect of further increasing the photopolymerization rate of the present composition and further improving the sensitivity. Examples thereof include allylthiourea, thiourea,
These substances include thioglycerin, triphenylphosphine, etc.
In the range 0.1% to 10%, preferably 0.5% to 5
The content is preferably within a range of %. Adhesion improvers are additives that have the function of increasing the adhesion between the cured coating film and the support, thereby improving image reproducibility and durability of the coating film. Particularly effective ones include aminosilane, epoxysilane, etc. There are so-called silane coupling agents, and the appropriate amount to be used is about 0.01 to 1% by weight based on the total amount of the composition. The development accelerator is a substance that has the effect of promoting dissolution or dispersion of the uncured photosensitive layer in water and facilitating development, especially when water development is intended. Preferred examples include long-chain alkylbenzene sulfur. Surfactants include sodium fluorinate and long-chain alkyl sulfate sodium salts. In addition, various additives such as plasticizers, dyes/pigments, fillers, etc. can be added to the photopolymerizable composition of the present invention, if necessary. The photopolymerizable composition of the present invention has an extremely wide range of uses such as printing plates, photoresists, paints, printing inks, adhesives, and reinforced molded products (FRP), but particularly useful uses include lithographic printing. Photosensitive image forming materials such as printing plate materials and photoresists. In these applications, the photopolymerizable composition of the present invention is most commonly dissolved in a solvent to form a solution, which is then applied onto a support by a known method and dried to form a film. This is a great way to use it. The support used here is generally a planar material that does not undergo significant dimensional changes; examples include metals such as aluminum, zinc, copper, and iron, polyethylene terephthalate, polystyrene, polymethyl methacrylate, Examples include polymeric substances such as nylon, cellulose acetate, polyethylene, polypropylene, bisphenol A polycarbonate, polyacrylonitrile, polyvinyl chloride, vinyl chloride/vinyl acetate copolymer, glass, silicon oxide, ceramics, paper, etc. . 2 thin plates of these materials
It is also possible to use materials in which more than one material is laminated, or a thin film of another material is formed on the surface of one material by means such as vapor deposition. In addition, the surface of the support as described above may be subjected to graining, electrolytic etching, chemical etching, etc.
It can be used after being subjected to treatments such as electrolytic oxidation and corona discharge, and can also be provided with a coating such as an adhesive layer or an antihalation layer. In addition, a negative (or positive) dampening water-less lithographic plate using a support coated with an ink-repellent silicone rubber layer (or a silicone rubber layer coated on a coating film of the photosensitive composition of the present invention) can be used. Printing plates can also be made. The photopolymerizable composition film of the present invention exhibits good photosensitivity as it is, but since the photopolymerization reaction is generally inhibited by oxygen, in order to obtain particularly high photosensitivity, exposure should be carried out in a vacuum or under nitrogen or carbon dioxide gas. It is preferable to conduct the photopolymerizable composition in an inert gas atmosphere, or to provide a transparent and oxygen-blocking coating on the surface of the photopolymerizable composition coating. Such coating methods include:
There are two methods: a method in which a solution of an oxygen-barrier and soluble polymer such as polyvinyl alcohol is applied onto the photosensitive coating and dried, and a method in which an oxygen-barrier plastic film is pressure-bonded and laminated on the surface of the photosensitive coating. Examples of the oxygen-blocking film used in the latter case include films of polyethylene terephthalate, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylidene chloride, cellophane, etc., or films made by laminating two or more thereof. The image-forming material made from the photopolymerizable composition of the present invention can be image-wise exposed by a conventional photographic method, that is, by exposing a negative film in close contact with light, by a method such as projection exposure, or by a method such as scanning exposure with a laser beam. Thereafter, an image can be formed by dissolving and removing the unexposed areas with a solvent that dissolves the photosensitive layer. Since the composition of the present invention is colored with a sensitizing dye,
A clear visible image can be obtained, and the resulting image has good ink receptivity and acid resistance, so it can be suitably used as a printing plate or resist. The photopolymerizable composition of the present invention is sensitive to radiation in a wide range of wavelengths from about 200 nm to about 650 nm, but is particularly sensitive to visible light with wavelengths of about 400 nm or more. Therefore, as the light source for exposure, a light source that mainly emits visible light, such as a tungsten lamp, a white fluorescent lamp, or a visible light laser, is preferably used. Of course, light sources that mainly emit ultraviolet rays, such as high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, and ultraviolet fluorescent lamps used for conventional photosensitive materials, can also be used. In particular, the photosensitive composition of the present invention has a maximum sensitivity around a wavelength of 500 nm, so it shows extremely high sensitivity to argon laser light (wavelengths of 488 nm and 514.5 nm), and therefore has a low output power, for example, an output of 100 m
Scanning exposure can also be performed using a small air-cooled argon laser device of W or less, so its application fields are extremely versatile. A further advantageous feature is that the composition of the present invention does not contain any expensive or difficult-to-synthesize components and can be prepared extremely easily and at low cost. The present invention will be described below based on production examples, examples, and comparative examples. (Note that all "parts" here are parts by weight.) Production example 1 Synthesis of binder polymers (A) to (C) (A) 60 parts of methyl acrylate, 40 parts of acrylic acid, 150 parts of ethyl alcohol and 50 parts of water were mixed, 0.5 part of azobisisobutyronitrile was added, and the mixture was reacted with stirring at 70°C for 8 hours. 60 parts of glycidyl methacrylate and 8 parts of pyridine were added to the obtained polymer solution, and the mixture was reacted at 75° C. for 3 hours with stirring. After diluting with ethyl alcohol, determine the solid content concentration.
Stored as a 20% solution. (B) 30 parts of styrene, 30 parts of methyl acrylate, 40 parts of methacrylic acid, 80 parts of ethyl alcohol, and 20 parts of water were mixed, 0.5 part of azobisisobutyronitrile was added, and the mixture was refluxed for 12 hours with stirring. 40 parts of glycidyl methacrylate and 15 parts of pyridine were added to the obtained polymer solution, and the mixture was reacted with stirring at 75°C for 4 hours. After adding ethyl alcohol, solid content concentration
Diluted to 20%. (C) Mix 40 parts of epoxy novolac resin (Ciel Chemical "Epicote" 154), 20 parts of methacrylic acid, 20 parts of methyl ethyl ketone, and 1 part of pyridine,
React at 75℃ for 5 hours with stirring, then add 20% methyl ethyl ketone/ethyl alcohol (1/1).
It was diluted to a specific concentration and stored. Production Example 2 Synthesis of photopolymerization initiator (b) component, (A) to (E) Mix a primary or secondary amine and an epoxy compound in the proportions shown in the following table, and react under appropriate reaction conditions with stirring. An additional reaction product was obtained.

[Table] ** “Shouamine” manufactured by Showa Denko Co., Ltd.
Example 1 40 parts of the polymer of Production Example 1-(A) (as a solid part) 50 parts of glycerin monomethacrylate, 1 part of erythrosine, 10 parts of the compound of Production Example 2-(A), 600 parts of ethyl alcohol, 500 parts of methyl ethyl ketone After graining, this solution was applied to an aluminum plate whose surface had been treated with an aqueous sodium silicate solution using a spin coater, and dried at 100°C for 5 minutes. The thickness of the coating film was approximately 5 μm. Next, a 12 μm thick polyethylene terephthalate film (“Lumirror” manufactured by Toray Industries, Inc.) was laminated on the surface of this coating film by pressure bonding using a roller to prepare a photosensitive material. An optical wedge (manufactured by Stouffer) with an optical density step of 0.15 and a test chart negative film were brought into close contact with this photosensitive material, and exposed for 3 seconds from a distance of 15 cm using a 100 W tungsten lamp. The cover film was peeled off and developed by rubbing lightly in tap water. The sensitivity (optical wedge curing stage number) was 5, and the test chart image faithfully reproduced the negative film image. In addition, an optical wedge and a test chart negative were placed on this photosensitive material, and wavelengths of 488 nm and 514.5 nm were placed on top of the wedge.
An argon laser beam (spot diameter 50 μm) that emits visible light of 10 m
Scanning was carried out under the conditions of W, scanning speed of 150 m/sec, and scanning line density of 90 lines/mm, and after peeling off the cover film, development was carried out with water. The sensitivity (optical wedge curing stage number) was 4, and the image faithfully reproduced the negative film image. Examples 2 to 10, Comparative Examples 1 to 2 Various solutions were prepared with the following compositions and applied to a surface-treated aluminum plate in the same manner as in Example 1. After drying,
Ethylene-vinyl alcohol copolymer film with a thickness of 15 μm (“Eval Film” manufactured by Kuraray Co., Ltd.)
EF-H) were laminated under pressure to form a photosensitive material. Binder 1-(B) 20 parts 1-(C) 30 parts Ethylene compound 40 parts Photoinitiator (a) 1 part (b) 5 parts Allylthiourea 2 parts Sodium nitrite
0.5 parts (dissolved in a small amount of water and added) Sodium dodecylbenzenesulfonate 3 parts Ethyl alcohol 400 parts Methyl ethyl ketone 500 parts Using photosensitive materials stored at room temperature for 5 days after preparation,
The mixture was stirred through an optical wedge and a test charted negative film under the following two conditions, and after the cover film was peeled off, it was developed with tap water and the sensitivity and image were examined. [Conditions] Expose for 1 second from a distance of 15 cm using a 100W tungsten lamp. An argon laser beam (diameter 50 μm) that emits visible light with wavelengths of 488 nm and 514.5 nm is used to scan the printing plate under the conditions of a light intensity of 1 mW, a scanning speed of 150 m/sec, and a scanning line density of 45 lines/mm. The results are shown in Table 1. The test chart images in the sensitivity range of 3 to 7 faithfully reproduced negative film images. The laser-exposed plate of Example 4 was used as a printing plate to print with a normal offset printing machine, and good printed matter was obtained.

【table】

Claims (1)

[Scope of Claims] 1. A photopolymerizable composition comprising an addition polymerizable compound having at least one ethylenically unsaturated bond and a photopolymerization initiator, wherein the photopolymerization initiator (a) has the following general formula: Compounds represented by [] [In the formula, M ₁ is a hydrogen atom or an alkali metal, M ₂
is a hydrogen atom, an alkali metal, an ammonium group,
a substituted ammonium group or an alkyl group,
X ₁ to _{X 8} are halogen atoms, hydrogen atoms, or monovalent organic or inorganic residues, and at least one of them is a halogen atom. ] and (b) a compound represented by the following general formula [] [In the formula, Ar is a monovalent or divalent aromatic residue (which may have a substituent such as an alkyl group), R ₁ to _{R 4}
is an alkyl group, substituted alkyl group, or aryl group, which can also be part of the side chain or main chain of the polymer. n is 0 or 1
It is. ] A photopolymerizable composition characterized in that it is a combination of.