JPS6046701B2 - light sensitive element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel photoreceptive elements, and more particularly to photoreceptive elements that act as positives.

Photosensitive compositions are known in the image reproduction art such that their solubility changes under the influence of radiation active on the photosensitive composition. A negative or positive working image is formed by decreasing or increasing the solubility of the composition in a suitable solvent, respectively. Compositions that produce negative images of the original are much more common than compositions that produce positive images. One system that works positively is o-
It is based on the photolysis of quinonediazide.

The resulting photolysis products are more soluble in aqueous alkali than the starting compounds. Another positive working system is disclosed in U.S. Pat. No. 3,782,951, which describes a composition of a hexaaryldiimidazole, a hydrogen donor, an ethylenically unsaturated compound, and an organic polymeric binder. ing. Further compositions which act as positives are known from DE 22 42 106 A1.

This composition contains 1,4-dihydro-4-(2''-nitrophenyl)pyridine as a photosensitizing compound, and primarily this produces a relatively high photosensitivity and is relatively easy to use. However, the disadvantage with this composition is that the effective solubility difference between exposed and unexposed image areas is not large enough for many practical applications. As a result of this small solubility difference, during the development process the unexposed areas begin to dissolve before relief image formation is complete, resulting in poor formed relief, thin layers and reduced image sharpness (
Sharp) is invited. These defects can be very disadvantageous in various applications. For example, if the material is used in printed circuit manufacturing, the photosensitive layer remaining on the support after development begins to dissolve and becomes so thin that it no longer fully serves its purpose as a resist pattern. I get used to it. The result is defective etching, which compromises the quality of the desired printed circuit. When this layer is used in the manufacture of offset plates, it does not have sufficient mechanical strength to withstand the applications to which such plates are subjected. A substantial difference in solubility in exposed and unexposed image areas, ie wide processing latitude, is an essential requirement that a photosensitive substrate processed by a development operation must meet. According to the invention,
a support carrying a photosensitive layer containing at least one polymeric binder and a dihydropyridine compound, the dihydropyridine compound having the formula
1 and R2 are alkyl, aryl, substituted aryl and heterocyclic ring, R3 and R4 are COOR'', C
OR' (wherein R'' is alkyl, substituted alkyl or aryl) and CN, and also R1 and R3 and/or R2 and R4 together represent a 5- or 6-membered carbocyclic or heterocyclic ring A photosensitive element for positive imaging is provided which is capable of forming a positive image.

The compounds of the invention defined above are summarized in the following table. Is alkyl 1-2 in R1 and R2?
carbon atoms, aryl ranges from 6 to 1 carbon atoms, and substituted aryl ranges from 6 to 14 carbon atoms. In R3 and R4, R''
is alkyl of 1 to 4 carbon atoms, substituted alkyl of 1 to 4 carbon atoms, or aryl of 6 to m carbon atoms. These 1,4-dihydro 4-(5″-
Nitro 2″-Frill) pyridine was prepared by Mr. Punch (FIa
It can be produced from 5-nitrofurfural, β-ketocarboxylic acid ester, β-ketocarboxylic acid nitrile, β-diketone and ammonia, or β-aminocrotonic acid ester by the pyridine synthesis method of
cyclec COMP Ourlds” Volume 1 (1950
) See pages 462 et seq.).

The synthesis of 1●4-dihydro2●6-dimethyl-4-(5''-nitro-7-furyl)pyridine-3,5-dicarboxylic acid ditertiary butyl ester (compound 3 of the table) is described next.

Other compounds are also produced in a similar manner. 24.4y
of 5 nitrofurfural diacetate, 33.2y of acetoacetic acid tertiary butyl ester, 5.0y of ammonium acetate and 5.077! t of ammonia solution (25
%) in 40 ml of pyridine in a steam bath for 6 hours.

After cooling, the solution is poured into 1e of ice water and left overnight at 0°C. The separated precipitate is recrystallized four times from hot ethanol. Yellow crystals 12y with a melting point of 195° C. are obtained.

For the production of light-sensitive recording elements, 1.4-
Dihydro-4-(5''-nitro-2''-furyl)-pyridine together with at least one known compatible organic binder (e.g. an alkali-soluble binder) onto a support, e.g. a film base, by conventional coating methods e.g. dip coating. , by spin coating, doctor knife coating, spraying, etc. It is known that a number of binders, such as alkali-soluble binders, are suitable for the purpose of the above-mentioned applications. These binders often contain alkali solubility promoting groups such as acid anhydride groups, carboxyl groups, sulfonic acid groups, and the like. Examples thereof include acrylic acid and/or methacrylic acid polymers and/or other suitable monomers thereof, such as acrylic esters or other acrylic derivatives, vinyl compounds such as vinyl ethers, vinyl acetates or their saponification products. , styrene, vinylpyrrolidone, copolymers with butadiene and related monomers, polyacrylic anhydride, maleic anhydride, maleic acid, maleic acid monoester,
Derivatives of monoamides and/or anhydrides and related compounds, such as copolymers of itaconic acid with suitable copolymers such as styrene, ethylene, vinyl ether, vinyl acetate, etc., polystyrene sulfonic acid and/or copolymers thereof, cellulose. Derivatives such as carboxymethylcellulose, cellulose phthalate or succinate, alginic acid and derivatives thereof may be mentioned. Furthermore, the phenol-formaldehyde resin known under the name "NOvOlac" is suitable.

Copolymers of maleic anhydride and styrene are particularly preferred polymeric binders for producing the elements of the invention.

The concentration of 1,4-dihydro-4(5″-nitro-7-furyl)pyridine is from about 20 to 20, based on the total weight of the photosensitive composition.
The weight is 8%.

The light-sensitive compounds can be used alone or in mixtures with one another. The concentration of polymeric binder is about 20 to 8 weight percent, based on the total weight of the composition. The sensitivity of the photosensitive layer can be improved by adding initiators or initiator systems.

Suitable initiators such as benzophenone, Michler's ketone, hexaarylbisimidazole and others are known from the literature. Michler's ketone, p-dimethylaminobenzaldehyde, 5-nitroimidazole and nitroaniline have proven effective. The photosensitive layer may also contain suitable dyes and pigments and other additives such as plasticizers, adhesion promoters and the like. When present, the initiator or initiator system can be used in amounts up to 1 weight percent, based on the weight of the total composition. As support it is possible to use the film bases commonly used for the production of photographic elements.

Suitable supports are paper, coated paper, foils and sheets of metals such as aluminum and copper, supports of synthetic polymeric materials such as polyethylene, polypropylene, polyesters such as polyethylene terephthalate and polyamides, as well as cellulose acetate, cellulose butyrate, and cellulose acetate. There is a butyrate support. This photosensitive layer can be coated directly onto these supports and used in this form for producing relief images.
It is also possible to first coat it on a temporary peelable support, preferably a transparent plastic film, and then transfer it by lamination onto the support to be used together. The thickness of this photosensitive layer is 10-15
It is in the range of 0 pm or more. The recording element can, for example, contain a customary intermediate layer for anchoring the photosensitive layer to its support.

Dyes, pigments, etc. may be present in the support or interlayer. For imaging, the photosensitive element is imagewise exposed to a radiation source that emits ultraviolet-rich radiation, such as a mercury vapor lamp, a xenon lamp, or the like. The element is then developed by washing away the exposed image areas. Preferably, aqueous alkaline solutions are used for washing, which may contain suitable alkalis such as alkali carbonates, borates and hydroxides as well as known carbonate, borate and phosphate buffer systems. . The cleaning solution can further contain surface-active substances. Naturally, depending on the polymeric binder used, organic solvents can also be used for washing. 1,4-dihydro 4-(5″
It is completely unexpected and surprising for the person skilled in the art that -nitro2''-furyl)pyridine is a photosensitive compound with such good properties.

Prior art document [J. Arrl. Chem. SOc. ,7
7 (1955) 447], it is known that photosensitivity is a function of the position of the nitro group in the molecule. That is, although 14-dihydro-4-(2''-nitrophenyl)pyridine in German Patent Application No. 2242106 is described as a photosensitive compound,
On the other hand, corresponding 3"- or 4"-nitro derivatives in which the nitro group is not in the ortho position to the bond are insensitive to light. Therefore, based on its position in the molecule, it would be unexpected to those skilled in the art that 1,4-dihydro-4-(5''-nitro-7-furyl)pyridine would be photosensitive. It is also unexpected that the photosensitive layers prepared from these compounds are superior to the compounds disclosed in DE-A-2242106.The best mode is illustrated in Example 4; In that case, the compound 3 in the table is l,4-dihydro2,6-
Offset printing using dimethyl-4-(5″-nitro-7-furyl)pyridine-3,5-dicarboxylic acid ditertiary butyl ester and styrene-maleic anhydride copolymer as an alkali-soluble organic polymeric binder. plates are manufactured.

The photosensitive elements of the invention are particularly suitable for the production of printing plates, especially offset printing plates, and for the production of printed circuits using elements with a peelable support. Transparent or opaque positive copies of line, screen or halftone originals can also be produced.
The following examples are intended to illustrate the invention.

The percentages herein are by weight unless otherwise specified. Example 1 A casting solution of the following composition is applied to an aluminum plate if the production of offset printing plates is intended.

Phenol-formaldehyde resin (trade name AlnOv)
Ol) 10.0 daglycol monomethyl ether 5.0y blue triarylmethane dye (Victoria Pure Blue FGA)
Compound 12.5y in the 0.1y table
p-dimethylaminobenzaldehyde 0.25y acetone 90.0ml The thickness of the dried layer is 20pm.

The plate is then exposed under the original photograph using a mercury vapor lamp (1000 W) at a distance of 60 CTt for 1 excitation second.

The exposed image areas are then washed using an aqueous solution having the following composition: A positive set printing plate with a long service life is obtained. Example 2 A photosensitive mixture of the following composition is applied to a polyethylene terephthalate film base, dried and gives a clear removable parfilm.

Methyl methacrylate (4%) in acrylic acid (5 mol%)
0 mol%)/ethyl acrylate (55 mol%) copolymer 10.0y Table Compound 1
45.0y triethylene glycol di-n-hexanoate/triethylene glycol di-n-octanoate (1:1) mixture 0.1y blue triarylmethane dye (Victoria Pure Blue F
GA) (dissolved in 100ml of methylene chloride)
The coating thickness of the photosensitive layer after drying for 0.1y is 50 μm.

After removing the cover film, this photosensitive layer is laminated onto a copper circuit board to form a photoresist for use in printed circuit manufacturing, and this is exposed under the original photo for 24 strokes at a distance of 60 cm for 2 minutes. Exposure was performed using a mercury vapor lamp (1000 W).

Development is carried out using a solution having the following composition. water
1e The plate is then etched in the usual manner with a normal ferric chloride solution.

After removing the photoresist film, a high quality printed circuit is obtained. Example 3 Coating Solution A is prepared with the following composition.

Enol formaldehyde resin (AlnOvOl)
9.0y Table Compound 44.5y Triethylene glycol di-n-hexanoate/triethylene glycol di-n-octanoate (1:1) mixture 0.1 g Blue triarylmethane dye (Victoria Pure Blue F
GA) 0.1y acetone
150.0y Ethylene glycol monoethyl ester 20.0y Separately, a coating solution B was prepared which contained compound (2) of DE-A-2242106 as a photosensitive compound.
It differed from solution A only in that it contained 4.5y of .

When these molding solutions are used for the production of offset printing forms, they are applied to aluminum plates and after drying 20 PTr! ．． Form a coating thickness of .

The element produced is exposed as described in Example 1 and the exposed parts are washed with a solution of the following composition. Na2cO32OyNa3PO4・12H20201
Na0H3.3y glycol monoedyl ether 20ml water
The following result is obtained by combining the total amount 1e.

Plate A Plate B image formation starts 2 circles 25 mackerel image formation complete 50 seconds
12 [Phase] Dissolution of layer 15 Box 215 Box 2
As is clear from the above results, plate A outperforms plate B over a fairly wide processing range.

Example 4 The following molding solution of a photosensitive composition is applied to an aluminum plate when used for offset printing plate production.

Styrene (50 mole %) - maleic anhydride (50 mole %) copolymer 5.0y Table Compounds 2.5y acetic acid ethyl ester Coating thickness of 100.0 ml dry coating is 20P7TL.

The element is exposed as described in Example 2.
The exposed image areas are then dissolved using a solution of the following composition: Na2cO32OqNa3PO4 ・12H2020y ・NaOH3y Glycol monoethyl ether 20ml water
The following result is obtained by combining the total amount 1e.

Start of image recording 2' Completion of image recording 5' Dissolution of layer 20σ seconds Example 5 A casting solution of the following composition is applied to a polyethylene terephthalate film base.

The dry coating thickness of this molded film is 10 μm. Styrene-maleic acid monoester copolymer
5.0q Compound 23.0y Red diazo dye (Ceres Red) 0
．． 5y methylene chloride 100.
After 0mt drying, 60C! UV lamp (10
00W) for 12 hours.

The exposed layer parts are then dissolved using a solution of the following composition: Na3PO4.121-12020y Methyl glycol 20y Water Total amount 1e A copy of the red original is obtained on a transparent support.

Example 6 A molding solution of the following composition is applied onto a polyethylene terephthalate film base and then dried.

(1:1) mixture of copolymer of methyl methacrylate (40 mol%), ethyl acrylate (55 mol%) and acrylic acid (5 mol%) with carbon black
10.0 da Mixture of triethylene glycol di-n-hexanoate and triethylene glycol di-n-ocnoate of Example 2
0.5rfL1 acetone
90.0 ml Then another layer of the following composition is applied over this layer.

Copolymer of styrene (50 mol%) and maleic anhydride (50 mol%) 10.0y Table compound 32.5y Example 2 triethylene glycol di n-
Hexanoic acid ester and trimethylene glycol di-n-
Octanoic acid ester 2.5mL
Acetate ethyl ester 100.0ml
After drying, the element is exposed to an ultraviolet lamp (1000 W) through the screen original for 2 minutes.

A positive screen image is obtained after washing the exposed spots using a solution of the following composition: Na3PO4・12H2020
y Methyl glycol 20ml Water Amount to make 1f total amount

Claims (1)

[Scope of Claims] 1 A support carrying a photosensitive layer containing at least one organic polymeric binder and a dihydropyridine compound, the dihydropyridine compound having the formula ▲ mathematical formula, chemical formula, table, etc. ▼ [wherein R_1 and R_2 are alkyl, aryl, substituted aryl and heterocyclic ring, R_3 and R_
4 is COOR', COR'(R' is alkyl, substituted alkyl or aryl) and CN, and also R_1 and R_3 and/or R_2 and R
_4 may be taken together to form a 5- or 6-membered carbocyclic or heterocyclic ring. 2. The element of claim 1, wherein the dihydropyridine compound is present in an amount of 20 to 80% by weight, based on the total weight of the photosensitive layer. 3. The element of claim 2, wherein the initiator is present in the photosensitive layer in an amount up to 10% by weight of the photosensitive layer. 4 Dihydropyridine compound is 1,4-dihydro-2,
6-dimethyl-4-(5'-nitro-2'-furyl)-
3,5-diacetopyridine, 1,4-dihydro-2,6
-dimethyl-4-(5'-nitro-2'-furyl)pyridine-3,5-dicarboxylic acid-ditertiary butyl ester and 1,4-dihydro-2,6-dimethyl-4-(5
2. The element according to claim 1, which is a member of the group consisting of '-nitro-2'-furyl)pyridine-3,5-dicarboxylic acid diethyl ester. 5 The photosensitive layer contains 1,4-dihydro-2,6-dimethyl-4- as the photosensitive compound.
(5'-nitro-2'-furyl)pyridine-3,5-dicarboxylic acid ditertiary butyl ester, and the organic polymeric binder is a copolymer of maleic anhydride and styrene. , the element listed in item 1 above.