JPH0588467B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a photosensitive composition suitably used for lithographic printing plates, photoresists, etc., and more specifically to a highly sensitive and positive photosensitive composition. [Prior Art] When an o-quinonediazide compound is irradiated with actinic rays, it produces a five-membered ring carboxylic acid and becomes alkali-soluble. It has been used as a photoresist. A photosensitive composition comprising this o-quinonediazide compound and an alkali-soluble resin such as a novolac resin is generally used, and various attempts have been made to improve the sensitivity of this photosensitive composition. For example, Japanese Patent Publication No. 56-19619 describes the addition of hydantoins and benzoic acid.
Publication No. 73045 describes the addition of a condensation product of hydroxybenzophenone and formaldehyde. However, in order to sufficiently increase sensitivity, large amounts of these additives must be added.
In this case, when used in an image-forming material, the solubility in a developing solution in the end-exposed area also increases, resulting in a disadvantage that the development tolerance becomes narrow. In addition, addition of phthalic anhydride, maleic anhydride, etc.
-80022) and the addition of a 6-membered cyclic acid anhydride (Japanese Unexamined Patent Publication No. 11932/1983), both of which are relatively effective in increasing photosensitivity, but long-term When used as an image-forming material after storage, the development latitude becomes narrower, and lithographic printing plates using these photosensitive compositions are susceptible to various chemicals used in plate-making operations (e.g., chemicals used for stain removal and gumming). Since the image area is easily attacked by water (e.g., alcohol-containing dampening water, etc.), plate skipping and background smearing are likely to occur, making it difficult to use as a printing plate for heavy printing. [Problems to be Solved by the Invention] An object of the present invention is to improve the above-mentioned drawbacks and to provide a photosensitive composition that is highly sensitive and has excellent long-term storage stability. Another object of the present invention is to provide a photosensitive composition that can be particularly suitably used as a lithographic printing plate. [Means for solving the problems] The present invention provides (a) a γ-lactone ring structure and an o-lactone ring structure in the molecule;
- A photosensitive composition characterized by containing a photosensitive polyurethane compound having a quinonediazide group and (b) an alkali-soluble resin. Examples of the above-mentioned γ-lactone ring structure include a structure represented by the following general formula (1).

〔Example〕

[1] Production of photosensitive polyurethane compound A γ-lactone ring compound and a diisocyanate compound having the composition shown in Table 1 were mixed with a solvent (diethylene glycol dimethyl ether) in the amount shown in Table 1 using a stirrer and a thermometer. The mixture was charged into a reactor and heated to 150°C with stirring to start the reaction. Thereafter, stirring was continued at 150°C for 8 hours to obtain (a) polyurethane compound precursor.
Next, it was cooled to 50°C, and the amount of solvent (diethylene glycol dimethyl ether) listed in the column of "Production of photosensitive polyurethane" in Table 1 was added.
Further, naphthoquinone-(1,2)-diazide-(2)-5-sulfonyl chloride in the amount listed in Table 1 as an o-quinonediazide compound having a halogenosulfonyl group was added and dissolved, and the mixture was maintained at 40 to 50°C. An aqueous potassium carbonate solution (40% aqueous solution) was added until the reaction solution became neutral. After making the mixture neutral, the mixture was stirred for about 5 hours to react, and then 10 times the amount of water as the reaction solvent was poured to precipitate the reaction product, which was then separated. This was washed with a small amount of isopropyl alcohol and vacuum dried at room temperature to obtain polyurethane compound (a). [2] Preparation of photosensitive composition Using the photosensitive polyurethane compound produced in [1] above, the photosensitive polyurethane compound and the novolac type phenolic resin PSF2807 (Gunei Co., Ltd.) were added as the alkali-soluble resin. A photosensitive composition was prepared by dissolving o-quinonediazide compound (manufactured by Kagaku Co., Ltd.), and optionally an o-quinonediazide compound having the composition shown in Table 2, various additives, etc. in a solvent. [3] Measurement of photosensitivity and evaluation of development acceptability of photosensitive composition [3]-1 Method for making photosensitive plate The composition prepared in [2] above was coated on a grained aluminum plate (thickness: 3 mm). A photosensitive plate was prepared by coating the film and drying it. The coating weight after drying was 2.0 g/m ² . [3]-2 Measurement conditions for photosensitivity and evaluation conditions for development tolerance
Output with 0.15 gray scale (density level 0 to 15) placed 1m away from the photosensitive plate.
Exposure was performed using a 1kW metal halide lamp [Idolfin 1000, manufactured by Iwasaki Electric Co., Ltd.]. Thereafter, this photosensitive plate was processed using a commercially available positive planographic printing plate developer "DP-4" (manufactured by Fuji Photo Film Co., Ltd.).
The film was developed with a 9-fold diluted aqueous solution at 20°C for 60 seconds. Sensitivity was expressed by the appropriate exposure time for this 60 second development. However, the appropriate exposure time at this time was defined as the exposure time at which the third stage of the gray scale was completely developed (became clear). Development acceptability was determined by exposing the photosensitive plate prepared in [3]-1 above for 60 seconds at the appropriate exposure time for development using the same exposure device as above, and then developing for 240 seconds using the same development method as above. The number of steps at which the gray scale becomes clear (hereinafter referred to as the number of clear steps) was measured and compared with the number of clear steps (3 steps) when developing for 60 seconds, and the difference in steps is shown. [4] Preparation of printing plate and evaluation of printing suitability A positive film with a test pattern was placed in close contact with a photosensitive plate prepared in the same manner as in [3]-1 above, and a metal halide lamp with an output of 1 kW was placed 1 m away from the photosensitive plate. (Idol Fin 1000 manufactured by Iwasaki Electric Co., Ltd.)
A printing plate was prepared by exposure at the appropriate exposure time in second development, followed by development for 60 seconds as before. The printing plate thus produced was mounted on a four-color lithographic printing machine, and printed using standard ink for lithographic printing under conditions similar to actual lithographic printing.
When printing suitability was evaluated after 50,000 copies were printed, clear images faithful to the originals were obtained in all printing plates, with no printing defects such as thick halftone dots, plate skipping, or blurring. [5] Evaluation of storage stability of photosensitive plate A photosensitive plate was prepared in the same manner as in [3]-1 above, and subsequently, as an accelerated test, it was placed in a constant temperature and humidity chamber (60°C, 60%
A photosensitive plate stored for 100 hours at RH) and a photosensitive plate without an accelerated test were prepared, and printing plates were prepared in the same manner as in [4] above, printed, and accelerated tests were performed. The storage stability of the photosensitive plates was evaluated by determining whether there were any differences in developability, photosensitivity, printability, etc., without conducting any tests.

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〔Effect of the invention〕

The photosensitive composition of the present invention has a 5-membered γ-lactone ring structure and contains a polyurethane compound having an o-quinonediazide group.
It is a good photosensitive material that is highly sensitive and has no problems in development tolerance, long-term storage stability, etc. The photosensitive composition of the present invention is particularly suitable as a photosensitive material for positive-working photosensitive printing plates, but is not necessarily limited to photosensitive planographic printing plates, such as ICs, lead frames, connectors, etc. It can also be used as a photosensitive material for microfabrication required when manufacturing electronic components such as.

Claims (1)

[Scope of Claims] 1. A photosensitive composition comprising (a) a photosensitive polyurethane compound having a γ-lactone ring structure and an o-quinonediazide group in the molecule, and (b) an alkali-soluble resin. 2. The photosensitive composition according to claim 1, wherein the γ-lactone ring structure is represented by the following formula. 3 (a) A photosensitive polyurethane compound having a γ-lactone ring structure and an o-quinonediazide group in the molecule contains a hydroxyl group obtained by reacting a polyhydroxy compound having a γ-lactone ring structure in the molecule with a polyisocyanate compound The photosensitive composition according to claim 1 or 2, which is obtained by reacting a polyurethane precursor with an o-quinonediazide compound having a halogenosulfonyl group. 4. The polyhydroxy compound having a γ-lactone ring structure in the molecule is selected from the group consisting of phenolphthalein, thymolphthalein, naphtholphthalein, o-cresolphthalein, tetrachlorophenolphthalein, and tetrabromophenolphthalein. The photosensitive composition according to claim 3, which is one or more kinds of compounds.