JPH06148885A - Photosensitive resin composition and ps board using that - Google Patents

Abstract

PURPOSE:To obtain a photosensitive resin compsn. having enough sensitivity for argon ion laser light of low energy by combining a specified triazine compd. and a titanosene compd. as a photopolymn. initiator. CONSTITUTION:This photosensitive resin compsn. contains a polymer binder, polyfunctional monomer and photopolymn. ionitiator. As for the photopolymn. initiator, a titanosene compd. and a triazine compd. expressed by formulae I, II and/or III are used. In formulae I-III, R<1>, R<2> are independently hydrogen atoms or methyl groups and R<3> is an alkyl group of 1-3 carbon number. Further, an acrydine compd. may be used as the photopolymn. initiator with compds. above mentioned. By this method, the titanosene compd. gives photosensitivity in a visible light region to the polymer binder. The triazine compd. has structural and physical features such as containing piperonyl groups and/or substd. styryl groups.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly sensitive photosensitive resin composition curable by visible light such as an argon ion laser and a PS plate using the same.

[0002]

2. Description of the Related Art In recent years, due to the development of electronic device technology such as computers, FA has been developed in the field of printing industry, and it has become possible to collectively carry out inputting, editing, proofreading and plate making of originals and image data. In the above plate making, a method of directly drawing with a laser beam is adopted, and as this laser beam, an argon ion laser having a wavelength of 488 nm in the visible region is preferably used. Therefore, it is desired to develop a resin composition having photosensitivity to visible light, for example, JP-A-63-260909.
JP-A-1-105238, JP-A-1-20341
3, JP-A-1-203414, JP-A-2-1714.
No. 2, JP-A-2-73813, JP-A-2-127404
Japanese Patent Application Laid-Open No. 3-239703, various proposals have been made.

Among the above techniques, Japanese Patent Laid-Open No. 63-26090
No. 9, JP-A-1-105238, JP-A-1-2034.
No. 13, JP-A-1-203414, JP-A-2-171.
No. 4 and JP-A-2-73813 each use acridine and a trihalomethyl group-containing triazine as a photopolymerization initiator. In addition, JP-A-2-12740
No. 4 and JP-A-3-239703 use a metallocene compound in addition to the photopolymerization initiator.

On the other hand, PS suitable for use in lithographic printing plates
As for the plate (Pre-Sensitized Plate), a roughened aluminum substrate 1 is anodized as shown in FIG. 1 to form an oxide film 2, and the surface is hydrophilized. There is known a technique of forming a photosensitive resin layer 3 by coating with. Further, if necessary, an overcoat layer 4 for the purpose of blocking oxygen may be provided thereon.

[0005]

The above-mentioned PS plate and the like require the use of an original film when exposed to ultraviolet rays having high energy, so that there is a problem of accuracy of the original film and the film and the photosensitive film. There was a problem of poor accuracy due to poor adhesion with the flexible resin layer. On the other hand, when laser light is used, the above problem does not occur because the original film is not used and scanning is performed directly. However, a low-wavelength laser having high energy has a problem in practical use because it has a short life. Further, since a relatively long wavelength argon ion laser or the like has low energy, it is necessary to use a highly sensitive photosensitive resin composition, and the advent of such a photosensitive resin composition has been desired.

However, the technique using the acridine and the trihalomethyl group-containing triazine described in each of the above publications has insufficient sensitivity to an argon ion laser,
Problems such as longer exposure time and lower precision due to poor curing remained unsolved. In addition, JP-A-2-127404
The technique of using a metallocene compound described in JP-A No. 1994-242242 also does not satisfy all of sensitivity, adhesion, developability and pattern shape.

[0007]

In order to solve the above problems, the photosensitive resin composition of the present invention is a photosensitive resin composition containing a polymer binder, a polyfunctional monomer and a photopolymerization initiator, As a photopolymerization initiator, a titanocene compound and a triazine compound described in the following (Chemical formula 1), (Chemical formula 2) and / or (Chemical formula 3) (wherein R ¹ and R ² each independently represent a hydrogen atom or a methyl group). , R ³ represents an alkyl group having 1 to ³ carbon atoms. Further, as the photopolymerization initiator, an acridine compound may be used in combination.

[0008]

[Chemical 1]

[Chemical 2]

[Chemical 3]

The PS plate of the present invention is roughened by mechanical polishing and electropolishing, and a photosensitive resin layer is formed on an aluminum substrate which has been subjected to an anodic oxide coating treatment and subsequent hydrophilic treatment. The PS plate is formed by applying the above-mentioned photosensitive resin composition of the present invention as a photosensitive resin layer. It is preferable to further provide an oxygen-blocking overcoat layer containing polyvinyl alcohol as a main component on the photosensitive resin layer.

The photosensitive resin composition of the present invention uses the special trihalomethyl group-containing triazine compound described in (Chemical formula 1), (Chemical formula 2) and / or (Chemical formula 3) as a photopolymerization initiator, and titanocene. By using a compound in combination, the sensitivity to visible light is improved, and curing with an argon ion laser is sufficiently possible. Further, since a PS plate using this composition can be printed using an argon ion laser, an original film is unnecessary. Therefore, printing accuracy is good and the number of plate making steps can be reduced.

The polymer binder used in the photosensitive resin composition of the present invention comprises a monomer having an aromatic hydroxyl group such as p-hydroxyphenyl (meth) acrylate and an aliphatic hydroxyl group such as 2-hydroxyethyl (meth) acrylate. Monomers having, (substituted) alkyl (meth) acrylates, (meth) acrylamides, vinyl ethers,
Polymerization or copolymerization of vinyl ester, vinyl ketone, alkylene-substituted aromatics such as styrene, olefins, (meth) acrylonitrile, or monomer having unsaturated double bond such as acrylic acid. It is a thing.

By adding an organic acid such as carboxylic acid to the above-mentioned monomer, an alkali developable binder can be obtained. In this case, the polymer binder to be formed preferably has an acid value of 100 to 150 and an average molecular weight of 10,000 to 20,000. When the polymer binder has a hydroxyl group or a carboxylic acid group, it may be modified with glycidyl (meth) acrylate or the like to further add an unsaturated double bond.

As a combination of monomers particularly preferable as the polymer binder, a combination of methacrylic acid / methyl methacrylate / benzyl methacrylate / hydroxyphenyl methacrylate, methacrylic acid /
Examples include a combination of methyl methacrylate / styrene / hydroxyphenyl methacrylate.

As the polyfunctional monomer as a crosslinking agent, ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, propylene glycol. Diacrylate, propylene glycol dimethacrylate, trimethylolpropane triacrylate,
Trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, Cardo epoxy diacrylate or the like is used.

As the photopolymerization initiator of the present invention, a titanocene compound and a triazine compound of (Chemical Formula 1), (Chemical Formula 2) and / or (Chemical Formula 3) are used as described above. The titanocene compound can impart photosensitivity in the visible light range to the polymer binder, and is disclosed in, for example, JP-A-2-127.
No. 404, No. 3-27393 and No. 3-239703.
Compounds (Chemical Formula 4) (provided that R ⁴
And R ⁵ represent the same or different cyclopentadienyl group which may be substituted, and R ⁶ and R ⁷ represent the same or different phenyl group which may be substituted. ) Can be used. The titanocene compound is used in an amount of 10 to 30% by weight, preferably 12 to 20% by weight, based on the solid content of the photosensitive resin composition. If the amount used is less than 10% by weight, the sensitivity in the visible light region may not be sufficiently increased, while if it exceeds 30% by weight, the strength of the resist pattern may decrease.

[0016]

[Chemical 4]

The triazine compound of the present invention has structural and physical properties such as containing a piperonyl group and / or a substituted styryl group as compared with the conventionally used bistrihalomethyltriazine, tristrihalomethyltriazine and the like. This is characteristic, and therefore, the sensitivity of the photosensitive resin composition can be increased about 10 times as compared with the case where the titanocene compound is added alone. These triazine compounds (Chemical Formula 1) to (Chemical Formula 3) are used alone or in a mixture, and used in an amount of 0.1 to 15% by weight, preferably 0.5 to 5% by weight, based on the solid content of the photosensitive resin composition. . If the amount used is less than 0.1% by weight, the sensitivity may not be improved. On the other hand, if it exceeds 15% by weight, problems such as generation of development residues or generation of foreign matter due to poor dissolution may occur. In addition,
In addition to the above triazine compound, a conventionally known trihalomethyltriazine compound may be added in such a range that the total amount thereof does not exceed 50% by weight of the total amount of the triazine compound.

In the present invention, it is preferable to use an acridine compound in order to prevent the sensitivity of the photosensitive resin composition from lowering due to oxidation in air. Examples of such acridine compounds include 9-phenylacridine,
9- (4-substituted) phenylacridine, 9-substituted aminoacridine, 1,7-bis (9-acridinyl) heptane, 1,5-bis (9-acridinyl) pentane, 1,
3-bis (9-acridinyl) propane is mentioned.
The acridine compound is used in an amount of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on the solid content of the photosensitive resin composition. If the amount used is less than 0.1% by weight, the measures to prevent the sensitivity from being lowered by oxygen may not be sufficiently exerted.
Further, if it exceeds 10% by weight, the developing speed may be drastically reduced,
Problems such as residual residue may occur.

In the photosensitive resin composition of the present invention, it is preferable to use a coumarin compound as a sensitizer for further increasing the sensitivity in addition to the above components. As the coumarin compound, the compounds shown in (Chemical formula 8) and (Chemical formula 9) or LS-157, LS-153, and LS- manufactured by Mitsui Toatsu Dyes Co., Ltd.
Compounds such as 158 are suitable, but are not limited to these. The coumarin compound is blended so that the absorbance of the photosensitive resin composition at 488 nm is 0.1 to 1.5, preferably 0.3 to 0.8. If this absorbance is less than 0.1 or exceeds 0.8, the sensitivity may decrease in some cases.

[0020]

[Chemical 8]

[Chemical 9]

In order to prepare a resist for an argon ion laser using the above-mentioned photosensitive resin composition, first, a known organic solvent such as methyl ethyl ketone, toluene, ethylene glycol monomethyl ether, 2-methoxyethanol, etc. is used as a photosensitive material. Solid content of resin composition 5 to
Dilute to about 20% by weight. Then, this solution is applied on a substrate such as aluminum or a polyethylene terephthalate (PET) film to prepare a dry film resist so that the dry film thickness becomes 1 to 4 g / m ² .
Blow and dry at room temperature to form a photosensitive resin layer.

On the photosensitive resin layer, it is preferable to further provide an overcoat layer containing polyvinyl alcohol (PVA) as a main component for blocking oxygen. This PVA
Are preferably those having an average molecular weight of 300 to 1000 and a saponification rate (hydrolysis rate of acetyl groups) of 70 to 90%, and are used by diluting with water to a solid content concentration of 5 to 20% by weight in consideration of coating properties. . At this time, it is preferable to add almost the same amount of SiO ₂ powder as PVA, and an appropriate amount of a surfactant such as a nonylphenylethylene oxide adduct. The dry thickness of this overcoat layer is preferably 1 to 2 μm.

The resist for argon ion laser completed in this way was manufactured by O.I. 5-3mW (1-3mJ / c
m ² ) argon ion laser light (wavelength 488 nm)
Can be exposed with high sensitivity. In this case, the hold time (holding time) is preferably about 30 minutes to 1 hour. The exposure using a laser emits a laser beam from a fine nozzle while scanning according to an instruction from a control device, and the exposure is far more accurate than the conventional ultraviolet irradiation method using an original film. It is possible,
Moreover, there is an advantage that the operation can be simplified. After the exposure, development is performed by brushing for about 1 minute at room temperature using a dilute Na ₂ CO ₃ aqueous solution, for example. The above-mentioned resist for argon ion laser is suitable for use as an etching resist for PS plates, letterpress printing plates, intaglio printing plates, printed wiring boards and the like.

The PS plate of the present invention is produced according to the above-mentioned method for producing a resist. The aluminum substrate or its alloy plate used is JIS A-1050 material, JIS A-
1100 material, JIS A-3003 material, JIS A-3103 material, JIS A-5005 material and the like. These aluminum substrates may be subjected to a pretreatment prior to being mechanically roughened to remove rolling oil on the surface as necessary or to expose a clean aluminum surface. Good. For the former, a solvent such as trichlorethylene, a surfactant, or sodium silicate is widely used, and for the latter, an alkali etching such as sodium hydroxide or potassium hydroxide is widely used.

Mechanical polishing is performed subsequent to the above pretreatment. As a method for mechanically roughening the surface of the aluminum substrate, various conventionally known methods can be used. For example, methods such as sand blasting, ball grain, wire grain and brush grain are included, and among these, brush grain is particularly preferable. For details of the brush grain method, see Japanese Patent Publication No. 51-46003 (or US Pat. No. 3,891,516) and Japanese Patent Publication No. 50-40.
No. 047. The mechanical surface roughening is preferably performed so that the center line average roughness Ra of the PS plate support obtained by the method of the present invention is 0.2 to 1.0 μm. Due to this mechanical roughening, undulations with a relatively large period (primary structure) and minute sharp irregularities (secondary structure) are formed on the entire surface of the undulation on the surface of the aluminum substrate. It

The surface of the aluminum substrate mechanically roughened as described above is then chemically etched. This chemical etching process has the function of removing abrasives, aluminum debris, etc., which have bitten into the surface of the mechanically roughened aluminum substrate, and also removing the minute sharp irregularities described above, and the electrical treatment applied after that. Chemical roughening can be achieved more uniformly and effectively. Details of such a chemical etching method are described in US Pat.
No. 834,998, which is a method of immersing aluminum in an aqueous solution of an acid or a base capable of dissolving aluminum. Examples of the above acid include sulfuric acid, persulfuric acid, hydrochloric acid, and the like, and examples of the above base include sodium hydroxide, potassium hydroxide, sodium triphosphate, dibasic sodium phosphate, tribasic potassium phosphate, and dibasic phosphoric acid. Includes potassium, sodium aluminate, sodium carbonate and the like. Among these, it is particularly preferable to use the latter aqueous solution of a base because the etching rate is faster. When the above chemical etching is carried out using an aqueous solution of a base, smut is generally formed on the surface of aluminum. In this case, therefore, phosphoric acid, nitric acid, sulfuric acid, chromic acid or two or more of these are used. It is preferable to perform so-called desmut treatment, which is a treatment with a mixed acid containing an acid.

The aluminum substrate treated as described above is then electrochemically roughened in an acidic electrolyte. The acidic electrolyte is an aqueous solution of nitric acid, hydrochloric acid or a mixture of nitric acid and hydrochloric acid, and a mixture of these acids and other acids such as organic acid, sulfuric acid and phosphoric acid. In addition, a corrosion inhibitor (or stabilizer) or the like can be added. The electrochemical roughening by the method of the present invention can be carried out by any of batch processing, semi-continuous method and continuous method.

After the completion of the electrolytic surface roughening, the aluminum substrate is again chemically etched with a base. This etching is the same as the method of immersing in the aqueous solution of the above base, and the above base such as sodium hydroxide is used. After the chemical etching with the base, it is preferable to perform desmut treatment with phosphoric acid, nitric acid, sulfuric acid, chromic acid or the like.

The aluminum substrate treated as described above is then anodized. This anodizing treatment can be performed according to a known method. For example, sulfuric acid, phosphoric acid,
Oxalic acid, chromic acid, amidosulfonic acid or a mixture of two or more of these, or an aqueous solution or non-aqueous solution containing Al ³⁺ ions in them as an electrolyte solution is anodized mainly by using a direct current. Alternatively, a combination of these currents can be used.

The aluminum substrate anodized as described above is further described in US Pat. No. 2,714,066 and US Pat. No. 3,18.
As described in each specification of No. 1,461, it can be hydrophilized by a method of immersing in an aqueous solution of an alkali metal silicate, for example, sodium silicate. Subsequent to the above silicate treatment, it is also preferable to further perform a hydrophilic treatment with phosphonic acid. Further, an undercoat layer composed of a polymer compound containing a monomer unit having a sulfonic acid group described in JP-A-59-101651, and an NH ₄ group described in JP-A-60-149491. , COOH group, SO ₃ H
An undercoat layer made of a compound having a group can also be used.

A PS plate can be obtained by providing a photosensitive resin layer of the photosensitive resin composition of the present invention on the PS plate support thus obtained. A bar coater, a wheeler, or the like is used to apply the photosensitive resin layer. Then, for example, it is dried at around 80 ° C. for 4 to 8 minutes.
The dry film thickness at this time is 1 to 10 g / m ² , preferably 2
~ 4 g / m ² . If the dry film thickness is less than 1 g / m ² , problems such as poor printing durability and poor inking may occur, while if it exceeds 4 g / m ² , problems such as inability to obtain practical sensitivity may occur.

Next, an oxygen-blocking overcoat layer containing polyvinyl alcohol (PVA) as a main component is provided on the photosensitive resin layer. This overcoat layer is also formed, for example, by using a roller coater, a wheeler, etc.
Dry for 1 to 3 minutes at around 0 ° C. Thus, the PS plate of the present invention is completed.

[0033]

According to the present invention, by combining a special triazine compound and a titanocene compound as a photopolymerization initiator, a photosensitive resin composition having sufficient sensitivity to low energy argon ion laser light is formed. be able to. In addition, since a PS plate produced using this photosensitive resin composition can be plate-made by an argon ion laser beam, a precise image can be obtained and the number of plate-making steps can be reduced.

[0034]

EXAMPLES Examples and comparative examples according to the present invention will be described below. Example 1 0.3% aluminum substrate (JIS A-1050 material) 10% N
It was immersed in an aOH aqueous solution at 50 ° C. for 20 seconds for degreasing, washed with water, then neutralized with a 25% H ₂ SO ₄ aqueous solution for 30 seconds and washed with water. Then, the surface of the aluminum substrate was brush-polished using a nylon brush and a 400-mesh permestone water suspension, and then thoroughly washed with water. 20% N of 70 ℃
Using an aOH aqueous solution, the amount of aluminum dissolved is 10 g
Alkali etching was performed so as to be / m ² .

Then, it was washed with water, desmutted with a 25% nitric acid aqueous solution, and then washed with water. The aluminum substrate thus treated was subjected to electrolytic graining. The electrolyte used is
It contained nitric acid at 15 g / l and the liquid temperature was 50 ° C. Following electrolytic surface roughening, alkali etching was performed using a 1% NaOH aqueous solution at 70 ° C. so that the dissolved amount of Al was 1 g / m ² , and 10%
After immersion in an H ₂ SO ₄ aqueous solution at 50 ° C. for 2 minutes for desmutting treatment, anodizing treatment was similarly performed in a 10% H ₂ SO ₄ aqueous solution to form an oxide film of 2.5 g / m ² . The support thus prepared was immersed in a 2.5% sodium silicate aqueous solution at 80 ° C.
The substrate was soaked for 1 minute in order to prepare a PS plate support.

On the other hand, as a photosensitive resin composition, a polymer binder methyl methacrylate / methacrylic acid / hydroxyphenyl methacrylate / benzyl methacrylate = 50/20/10/20 100 parts by weight polyfunctional acrylic compound trimethylolpropane triacrylate 55 〃 photopolymerization Initiator-Titanocene compound Compound described below (Chemical Formula 5) 25 "-Triazine compound Triazine P (manufactured by PANCHIM) 7" -9-phenylacridine 3 "Sensitizer Coumarin 2" Solvent Methylethylketone / toluene = 7/2 160 " Was prepared.

[0037]

[Chemical 5]

The above-mentioned photosensitive resin composition is provided on the support,
After coating so as to have a dry film thickness of 3.5 g / m ² , after drying, an aqueous solution of PVA and SiO ₂ powder (PVA /
SiO ₂ / water = 7/7/86; weight ratio) and dry film thickness is 1.
It was applied so as to be 5 g / m ² . P thus obtained
The S plate was scanned and exposed to an argon ion laser having an intensity of 1 mJ / cm ² to draw a pattern. Na ₂ C at 26 ° C after exposure
A printed pattern was obtained by immersing in a 0.5% O ₃ solution for 3 minutes. This pattern was good in that there was little film loss due to the developer and there was no resist residue in the unexposed areas. Finally, after gumming with gum arabic, 1 J / m ^{2 of} post exposure was carried out with a metal halide lamp to complete a printing plate.

Example 2 A PS plate was prepared in the same manner as in Example 1 except that 7 parts by weight of triazine PES (manufactured by PANCHIM) was used instead of triazine P in the preparation of the photosensitive resin composition. Obtained. The PS plate was developed by scanning exposure with an argon ion laser of 2.5 mJ / cm ² , and Example 1
A good printed pattern similar to that obtained was obtained.

Example 3 A PS plate was obtained in the same manner as in Example 1 except that the amount of the titanocene compound used in the preparation of the photosensitive resin composition was changed to 10 parts by weight. When this PS plate was subjected to development by scanning exposure with an argon ion laser at 12 mJ / cm ² , there was some film loss in the exposed area, but partial chipping or peeling was not confirmed. When the amount of the titanocene compound is reduced as compared with this example, it is considered that the effect of the present invention cannot be obtained.

Comparative Example In Example 1, 2,4-bis-trichloromethyl- was used instead of 7 parts by weight of triazine P in the preparation of the photosensitive resin composition.
A PS plate was obtained in the same manner as in Example 1 except that 7 parts by weight of 6- (4-styrylphenyl) -S-triazine was used. This P
The S plate was exposed by an argon ion laser scanning exposure of 3.5 mJ / cm ² and developed, but the film loss in the exposed part was large,
Moreover, a part was chipped and peeled off. Further, a resist residue was found in a part of the unexposed area.

[0042]

As described above, the photosensitive resin composition of the present invention contains the special trihalomethyl group described in (Chemical formula 1), (Chemical formula 2) and / or (Chemical formula 3) as a photopolymerization initiator. Since the triazine compound is used and the titanocene compound is used in combination, it is possible to form a photosensitive resin composition having sufficient sensitivity to an argon ion laser beam having a low energy in a visible light region. In addition, since the PS plate produced by using this photosensitive resin composition can be produced by argon ion laser light, an original film is not required. Therefore, printing accuracy is good and the number of plate making steps can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the structure of a PS plate.

[Explanation of symbols]

1 ... Aluminum substrate, 2 ... Oxide film, 3 ... Photosensitive resin layer, 4 ... Overcoat layer.

[Chemical 6]

[Chemical 7]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number in the agency FI Technical indication location G03F 7/11 501 (72) Inventor Shunmi Aoyama 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyoka Industry Co., Ltd.

Claims (4)

[Claims] 1. A photosensitive resin composition containing a polymer binder, a polyfunctional monomer and a photopolymerization initiator, wherein a titanocene compound as the photopolymerization initiator and the following (Chemical formula 1), (Chemical formula 2) and / or (Chemical formula 1) Chemical formula 3) (wherein R ¹ and R ² independently represent a hydrogen atom or a methyl group, and R ³ represents an alkyl group having 1 to 3 carbon atoms). A photosensitive resin composition. [Chemical 1] [Chemical 2] [Chemical 3] 2. The photosensitive resin composition according to claim 1, wherein an acridine compound is further used in combination as the photopolymerization initiator. 3. A photosensitive resin layer is formed on an aluminum substrate which has been roughened by mechanical polishing and electrolytic polishing, and which has been further anodized and hydrophilized.
In S plate, the said photosensitive resin layer consists of the photosensitive resin composition of Claim 1 or 2, The PS plate characterized by the above-mentioned. 4. The PS plate according to claim 3, further comprising an overcoat layer containing polyvinyl alcohol as a main component on the photosensitive resin layer.