JP2954302B2 - Photosensitive resin composition for screen printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION

[Industrial application field] The present invention has a sensitivity characteristic required as a scanning recording material by visible argon laser light, and the photosensitive layer has a thickness of 10 μm.
The present invention also relates to a photosensitive resin composition for a screen printing plate suitable for a photosensitive resin material which can be cured and which is excellent in practical physical properties and storage stability as a screen printing plate. [Prior art] Currently, in order to manufacture a screen printing plate using laser light, patterning is performed on a silver halide film using a laser photoplotter or the like based on an image pattern designed by a CAD / CAM system. After producing a positive film (film production process), the positive film was placed on a PS plate for screen printing, and the plate was made by baking ultraviolet rays (plate making process). On the other hand, photopolymerizable compositions having photosensitivity to visible laser light are disclosed in, for example, JP-A-57-114139, JP-A-59-1142205, and JP-A-65-43133. A photopolymerizable composition containing a sensitizing dye and a photosensitizer (photoinitiator) is known. [Problem to be Solved by the Invention] The plate making method using the CAD / CAM system requires a film manufacturing process at present and is indispensable. However, in the future, a visible argon laser beam (488 nm wavelength) will be used. It is expected that a system that draws directly on the screen PS version will be possible. In that case, advantages such as shortening of the plate making process, shortening of the delivery date, reduction of production and management costs, improvement of position accuracy and resolution, and the like can be expected. However, the photopolymerizable compositions described in the above publications having photosensitivity to visible laser light are used as screen printing plate materials because all of them have been developed only as IC-based resists. To be used for the following reasons. . At present, the thickness of a photosensitive coating film that can be exposed using visible argon laser light (wavelength: 488 nm) is only as thin as several microns, and is as thin as 10 μm or more in terms of strength and other factors. Is not suitable for screen printing that requires a photosensitive coating. Therefore, in order to increase the thickness of the photosensitive coating, it is necessary to further increase the sensitivity of the photopolymerizable composition. . With such a known photopolymerizable composition, the physical properties of the photocured film are insufficient in terms of practical physical properties such as printing durability and solvent resistance and storage stability.

Summary of the Invention

[Summary] The present inventors have conducted intensive studies in view of the above problems, and as a result, have found that a photosensitive resin composition comprising a specific photosensitive resin blended with a specific photopolymerization initiator and a photosensitizer is used as a photosensitive layer. The screen printing plate used as a substrate can be easily cured with visible argon laser light (wavelength 488 nm) even if the thickness of the photosensitive layer is 10 μm or more, and the physical properties of the photocured film are screen printing plates. The present invention has been completed based on the finding that practical physical properties as well as storage stability are sufficient. That is, the photosensitive resin composition for a screen printing plate of the present invention is an addition-polymerizable compound having an ethylenically unsaturated double bond with respect to 100 parts by weight of an alcohol-soluble polyamide resin developable with water or a weakly acidic aqueous solution. 20-50
0 parts by weight, and the photopolymerization initiator shown below, and
And the following photosensitizers are contained in the following quantitative ratios. . Coumarin dyes. Benzophenone group-containing polyvalent peroxyester:
50-500% by weight, A compound having a methylene group at the α-position of the nitrogen atom: 50 to 1,000% by weight [Effect] The present invention comprises a specific photosensitive resin containing a specific photopolymerization initiator and a photosensitizer. Screen printing plates using a photosensitive resin composition as a photosensitive layer can be easily cured by visible argon laser light (wavelength 488 nm) even if the thickness of the photosensitive layer is 10 μm or more,
The physical properties of the photocured film are sufficient in terms of practical physical properties as a screen printing plate and storage stability, and are suitable as a photosensitive resin for screen printing.

DETAILED DESCRIPTION OF THE INVENTION

[I] Photosensitive resin composition for screen printing plate (1) Component (a) Alcohol-soluble polyamide resin developable with water or a weakly acidic aqueous solution Water or water used in the photosensitive resin composition for screen printing plate of the present invention Examples of alcohol-soluble polyamide resins that can be developed with a weakly acidic aqueous solution include commercially available tertiary amino groups or quaternized polyamide resins, sulfonic acid (salt) group-containing polyamide resins, ether group-containing polyamide resins, An alcohol-soluble polyamide resin such as a hydroxy group-containing polyamide resin can be used. Among these alcohol-soluble polyamide resins, it is preferable to use a polyamide resin containing a tertiary amino group containing a tertiary nitrogen atom in the constituent monomer molecule. Such polyamide resin containing a tertiary nitrogen atom in the constituent monomer molecule, those obtained by a polycondensation reaction of a monomer containing a tertiary amino group in the molecule,
Alternatively, it is obtained by a copolycondensation reaction with another monomer as necessary. Monomers containing a tertiary nitrogen atom, especially an amino group, in the molecule include 6,6-bis (N, N-dimethylamino)
-4,8-dioxa-1,11-undecanediamine, N, N-bis (β-aminoethyl) -alkylamine, N, N-bis (aminoalkyl) -ethylenediamine, N, N′-dialkyl-N, Diamines having a nitrogen atom in the molecule, such as N'-bis (aminoalkyl) -ethylenediamine, N, N'-dialkyl-N, N'-bis (aminoalkyl) -hexamethylenediamine, N- (aminoalkyl)- N-
(Carboxyethyl) alkylamine, N, N-dialkyl-N- (aminoalkyl) -N- (carboxyethyl) hexamethylenediamine, N- (aminoalkyl)
Ω-amino acids such as -N- (carboxyethyl) -piperazine and the like. These polyamide resins preferably have a molecular weight of 10,000 to 50,000, particularly 15,000 to 30,000. The diamine can be condensed with a dibasic acid to form a polyamide resin, and the ω-amino acid can be singly or copolycondensed with another dibasic acid, diamine or the like to form a polyamide resin. The polyamide resin preferably used in the present invention is nylon as a copolycondensate of the following compounds 1 and 2. Compound 1: N, N-bis (γ-aminopropyl) piperazine, , N-bis (γ-aminopropyl) piperazine adipate, which is a salt of adipic acid with HOOC (CH ₂ ) ₄ COOH, Compound 2: ε-caprolactam The structure of such a copolycondensation nylon can be generally represented by the following general formula. General formula (However, m and n are arbitrary integers.) (B) An addition-polymerizable compound having an ethylenically unsaturated double bond, the ethylenically unsaturated compound used in the photosensitive resin composition for a screen printing plate of the present invention. Examples of the addition-polymerizable compound having a saturated double bond include those having at least one photoactive ethylenically unsaturated group such as an acryloyl group, a methacryloyl group, an allyl group, a vinyl ether group, an acrylamide group, and a methacrylamide group. Those insoluble or poorly soluble in water are preferably used. In particular, those having two or more photoactive ethylenically unsaturated groups are preferable because they give cured products having good solvent resistance. The photoactive unsaturated compound includes a photoactive prepolymer or oligomer having a molecular weight of 10,000 or less, in addition to a photoactive compound usually called a vinyl monomer. Specific examples of such a photoactive unsaturated compound include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dibromo Neopentyl glycol di (meth) acrylate, 2,8-dibromopropyl (meth) acrylate, triallyl isocyanurate, methoxyethyl vinyl ether, tertiary butyl vinyl ether, lauryl (meth) acrylate,
Methoxyethylene glycol (meth) acrylate, 2
-Ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, hexyl diglycol (meth) acrylate, ethylene glycol (meth) acrylate, di-hexaethylene glycol di (meth) acrylate , Ethylene glycol diglycidyl ether (meth) acrylate, 2-ethyl-hexyl glycidyl ether (meth) acrylate, 2-methyl-octyl glycidyl ether (meth) acrylate, trimethylolpropane polyglycidyl ether poly (meth) acrylate, terephthalic acid Glycidyl ether (meth) acrylate, a reaction product of tricleandiisocyanate with 2-hydroxylpropyl (meth) acrylate, Such as the reaction product of cyanate and 2-hydroxyethyl (meth) acrylate, or, such as molecular weight of 10,000 or less of an unsaturated polyester having an ethylenically unsaturated group, such as maleic acid glycol ester and the like. In the above examples of compounds, the phrase “(meth) acrylate” means both acrylate and methacrylate. These addition-polymerizable compounds having an ethylenically unsaturated double bond may be used alone or in combination of two or more to form a polyamide 100 containing a tertiary nitrogen atom in the monomer molecule.
It is used in the range of 20 to 500 parts by weight, preferably 50 to 200 parts by weight, based on parts by weight. If the amount of the addition-polymerizable compound having an ethylenically unsaturated double bond is too small, the water resistance of the cured product is not sufficient, and if it is too large, the composition may be separated and deposited on a dried film. is there. (C) Photopolymerization initiator and photosensitizer The photopolymerization initiator and photosensitizer used in the photosensitive resin composition for a screen printing plate of the present invention include: It is important to include a sensitizer. Record . Coumarin dyes,. A polyvalent peroxyester containing a benzophenone group; Compounds having a methylene group at the α-position of the nitrogen atom Coumarin-based dyes The coumarin-based dyes that are photosensitizers include coumarin dyes represented by a general formula. Benzophenone group-containing polyvalent peroxyester The benzophenone group-containing polyvalent peroxyester which is the photopolymerization initiator is 3,3'4,4'-tetra- (t-butylperoxycarbonyl) benzophenone represented by the following general formula. (Note that “t-Bu” and “Bu-t” in the above formula represent tertiary butyl.) Compound having a methylene notation at the α-position of a nitrogen atom α-position of a nitrogen atom which is the photosensitizer described above. Examples of the compound having a methylene group include triethylamine, N-methyldiethanolamine, triethanolamine, N-ethyl-N-benzylaniline, N-methyldiethanolamine, N, N-diethyl-p-phenylenediamine, N
-Phenylglycine and the like, especially N-
Phenylglycine, N-methyldiethanolamine and triethanolamine are preferred. Since the photosensitive resin composition of the present invention containing these three types of photopolymerization initiators and photosensitizers can be particularly sensitively exposed to argon laser light, it can be used in a system for directly drawing using visible argon laser light. Can be applied. The ratio of these photopolymerization initiators is 0.1 to 15 relative to 100 parts of the addition-polymerizable compound having an ethylenically unsaturated double bond.
Parts, especially in the range of 0.3 to 10 parts. The ratio of the photopolymerization initiator and the photosensitizer used in the above-mentioned is 50 to 500%, 50 to 1,000%, preferably 100 to 500%, and 200 to 500% of the components. 600%, particularly preferably 100-300% of ingredients,
Ingredients are in the range of 200-400%. [II] Preparation of photosensitive resin composition for screen printing plate In order to obtain the photosensitive resin composition for screen printing plate of the present invention from each of the above components, it is produced by generally employing the following method. . That is, the tertiary nitrogen-containing copolymer polyamide resin was dissolved in a mixed solvent of methanol and trichloroethylene and the like, and triacrylate phosphate, glycerol diacrylate and pentaerythritol triacrylate were added thereto and dissolved. The first liquid,
Then, a photopolymerization initiator, a photosensitizer, and the like are added to the first liquid at a ratio of 1 to 20% by weight, and the mixture is thoroughly stirred and dissolved to form a photopolymerizable composition solution (photosensitive material). And [III] Formation of photosensitive layer A screen made of gauze made of 80-400 mesh tetron woven cloth or the like on an aluminum mold in a conventional manner is used as a screen plate, and a photosensitive material is placed on the screen using a bucket. (In general, the layers are laminated in a thickness of 2 to 400 μm, preferably 10 to 400 μm, particularly preferably 10 to 40 μm). Then, this is dried in a dryer at a temperature of 30 to 50 ° C. to form a photosensitive film to obtain a PS plate for screen printing. After that, 5% polyvinyl alcohol (90% saponification degree, polymerization degree
500) It is preferable to form an overcoat layer by applying an aqueous solution so as to have a thickness of 5 to 6 μm. [IV] Exposure The PS plate for screen printing on which a photosensitive film made of the photosensitive resin composition for screen printing plate is formed is exposed using an exposure apparatus 1 as shown in FIG. The exposure apparatus 1
An exposure apparatus 1 in which an argon laser transmitter 3 and an argon laser scanner 4 are directly connected to a CAD / CAM system 2. Such an exposure apparatus 1 is an apparatus 1 that can directly draw an image pattern designed by a CAD / CAM system 2 on a PS plate 5 for screen printing using visible argon laser light (wavelength 488 nm). . As such an apparatus, a modified coaxial facsimile capable of condensing a beam having a wavelength of 488 nm of an argon laser as the argon laser scan 4 and directly drawing an image can be used. The laser beam is focused on a 25 nm point light source, and this is AO (Acousto Op
tic) A test signal modulated by the modulator 6 can be used. The photosensitive film of the PS plate for screen printing is cut out from the aluminum mold, wound and fixed on the scanning experiment drum 7 so as not to be wrinkled, and a focused beam is applied to the photosensitive film. Exposure is performed at a scanning speed of 9.8 m / sec. Scanning line densities are typically performed at 300 to 1,000 lines / inch. [V] Image In the case where a normal water-soluble photosensitive resin such as polyvinyl alcohol is used in the photosensitive resin composition for a screen printing plate of the present invention, the photosensitive resin composition can be developed with ordinary water. When a polyamide resin having a tertiary nitrogen atom in the molecule is used as the polyamide resin constituting the resin, it is a water-insoluble polymer and cannot be developed with water. Therefore, it is important to use an acidic aqueous solution to solubilize such a special polyamide resin. The tertiary nitrogen atom in the molecule of the polyamide resin is quaternized by this acidic aqueous solution, so that a water-soluble polyamide polymer can be obtained. The acidic aqueous solution generally has a hydrogen ion concentration (pH) in the range of 3 to 6, preferably 3 to 5. As such an acid, an organic acid such as acetic acid and oxalic acid, a mineral acid such as hydrochloric acid and nitric acid and the like can be used, but an organic acid is preferably used from the viewpoint of environmental protection. However, since the portion of the photosensitive resin that has been exposed and cured by photopolymerization is intertwined with the polymer of the addition-polymerizable compound having an ethylenically unsaturated double bond, the polyamide resin in the photosensitive resin is intertwined. Since the tertiary nitrogen atom in the polyamide resin is hard to be quaternized, it is hard to be solubilized and a water-resistant screen printing plate can be obtained. [VI] Screen printing plate The screen printing plate obtained in this way is screen PS using visible argon laser light (wavelength 488 nm).
A system for directly drawing on a plate becomes possible, and there are many advantages such as shortening of a plate making process, shortening of delivery time, reduction of production and management costs, and improvement of position accuracy and resolution.

[Experimental example]

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The raw materials used in each Example and Comparative Example are as follows. Raw materials Photopolymerization initiator and photosensitizer Component (a): Coumarin dye represented by the following general formula Component (b): 3,3'4,4'- represented by the following general formula
Tetra- (t-butylperoxycarbonyl) benzophenone Component (c-1): N-phenylglycine Component (c-2): N-methyldiethanolamine Component (c-3): triethanolamine. Examples 1 to 8 and Comparative Examples 1 and 2 Preparation of Photopolymerizable Composition 100 parts of a tertiary nitrogen-containing copolymer polyamide resin (manufactured by Toyobo Co., Ltd.) in a mixed solvent of 100 parts of methanol and 300 parts of trichloroethylene. After dissolution, 30 parts of phosphoric acid triacrylate, 50 parts of glycerol diacrylate and 20 parts of pentaerythritol triacrylate were added and dissolved to obtain a first liquid. Next, a photopolymerization initiator such as a sensitizing dye and photosensitizers (components (a) to (c)) mixed in the proportions shown in Table 1 were added to the first liquid and stirred. And dissolved to obtain a photopolymerizable composition solution (photosensitive material). Preparation method of photosensitive layer (test plate) The above-mentioned photosensitive material was applied to a 75 μm thick polyester sheet using a bar coder at a dry film thickness of a predetermined thickness (25 mm).
(Approximately 40 μm), and the photosensitive film was dried with a hot-air dryer at 50 ° C. Next, a 5% aqueous solution of polyvinyl alcohol (degree of saponification: about 90%, degree of polymerization: about 500) is applied on the photosensitive layer using a bar coder so as to have a dry film thickness of 2 to 4 μm.
After drying, a test plate was prepared. Measurement of Sensitivity A step guide P (15 steps) manufactured by Fuji Photo Film Co., Ltd. was superimposed on the test plate, and a continuous light of a xenon lamp (300 Watt manufactured by Oak Manufacturing Co., Ltd.) was taken out by filtering. Light equivalent to almost monochromatic light having a peak at a wavelength of 488 nm (light intensity; 174 mW / c
m ² ) was irradiated from above for 60 seconds. The exposure energy required for curing is calculated based on the number of stages that were developed and developed with a developer (0.6% acetic acid aqueous solution) and photocured, and the value was used as the sensitivity (mj / c
m ² ). The results are shown in Table 1. Examples 9 to 15 Preparation Method of Argon Laser Scanning Sample Screen Plate Tetron 250-mesh yellow gauze was spread on an aluminum mold in accordance with a conventional method. The photosensitive material prepared in the same manner is overcoated with a bucket to a predetermined thickness using a bucket.
After drying with a drier at a temperature of ° C., polyvinyl alcohol was applied on both surfaces after exposure to a thickness of 5 to 6 μm to prepare a screen plate having an overcoat layer formed thereon. Image formation with argon laser Argon laser 48 as argon laser scanner
A modified coaxial facsimile capable of condensing a beam with a wavelength of 8 nm and drawing directly was used. The beam was focused on a 25 nm point light source, and a test signal modulated by an AO modulator was used. Cut the photosensitive film of the screen plate from the aluminum mold, wind and fix it carefully so as not to wrinkle on the scanning experiment drum, and apply 9.8 m / sec while applying a condensed beam on this photosensitive film Exposure was performed at a scanning speed of The scanning line density is set to 600 lines / inch.
Spray development was performed with the above weak acid solution. The results are as shown in Table 2, which shows that the binder is 100 parts of nylon, the ethylenically unsaturated compound 1
A photosensitive material for a screen plate was prepared by applying components (a), (b), and (c) to each of 00 parts by changing the amount of each component, and applied. From the results in Table 1, it can be seen that the three components of components (a) to (c) are used in combination as a photopolymerization initiator and a photosensitizer, and that only two components of components (a) and (b) are used. Compared with the case where the combination of the components (a) to (c) is adopted, the sensitivity difference is twice or more, and the photosensitive resin composition of the present invention in which the three components (a) to (c) are combined is more effective. This indicates that the utility is high. Also, from the results in Table 2, it is recognized that the composition exhibits high photosensitivity to visible laser light. Further, when the photosensitive layer is used after being thickened to a thickness of 25 μm or more, for example, when it is used as a film having a thickness of 40 μm, the concentration of the component (a) is reduced as in Examples 4 and 5. Can be made to correspond. Although the apparent sensitivity is slightly lowered by this, it is possible to correct the imbalance between the photocured state of the film surface caused by the filter effect and the photocured state on the back side of the film, that is, on the adhesive surface of the support. In addition, in an experiment for practical application to a screen printing plate, as shown in Table 2, the total thickness (including a thickness of 58 μm)
Although a screen printing plate having a thickness of μm was obtained, a clear image was obtained by the argon ion laser beam, indicating that this photosensitive material was highly practical in terms of performance.

[Brief description of the drawings]

FIG. 1 shows an exposure apparatus in which an argon laser scanner is directly connected to a CAD / CAM system according to an embodiment of the present invention. 1: Exposure device 2: CAD / CAM system 3: Argon laser scanner 4: Argon laser transmitter 5: PS plate for screen printing 6: AO modulator 7: Drum for scanning experiment

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03F 7/028 G03F 7/037 G03F 7/027

Claims (1)

(57) [Claims] An addition-polymerizable compound having an ethylenically unsaturated double bond per 100 parts by weight of an alcohol-soluble polyamide resin developable with water or a weakly acidic aqueous solution.
A photosensitive resin composition for a screen printing plate, comprising -500 parts by weight, the following photopolymerization initiator, and the following photosensitizer in the following quantitative ratios. . Coumarin dyes. Benzophenone group-containing polyvalent peroxyester:
50-500% by weight, Compound having a methylene group at the α-position of the nitrogen atom: 50 to 1,000% by weight