DE2718047B2 - Photopolymerizable mixture that can be developed with water - Google Patents

Description

The invention relates to a photopolymerizable, water developable mixture containing a Methacrylic acid polymer as a binder, an ethylenically unsaturated compound, which at normal pressure boils above 100 ° C and contains at least two ethylenically unsaturated groups per molecule, as well as one

s photopolymerization initiator,

The usual photosensitive or precoated lithographic plates can be of two types subdivide: One is called the outer type, after which, after exposure and development, a varnish,

ίο that selectively adheres to the image areas and the Ink receptivity and printing durability increased, while the other than inner type is called, in which the ink adhesion and the mechanical strength of the image ches improving ingredient that is incorporated consequently in a printing press immediately after exposure and development can.

It goes without saying that it is beneficial for both

Species is that the plate with neutral tap water from the point of view of lowering the surface area of the printing form production, of preventing contamination and on the control of the operational stages is viable Though certain disks of the external kind can be developed using water-soluble diazo resins with water, are not yet Plates of the inner type which can be developed with tap water and which show satisfactory printing behavior are known, for example have printing plates based on photopolymerizable mixtures, which basically contain a water-soluble resin and an unsaturated group Monomer include the disadvantage that the image areas swell during development or a have insufficient oleophilicity in the image areas, resulting in poor ink receptivity. Although an increased amount of the oieophiien Besiendetiis certainly to improve the oleophilic nature of the image areas is effective such a measure unfortunately gives rise to one Another disadvantage, such as bleeding or phase separation due to the crystallization of the in larger quantities present component; furthermore, in some cases the viscosity of the photosensitive layer drops sharply, so that a sticky printing surface is obtained.

From DE-OS 20 64 080 and 22 05146 are photopolymerizable mixtures known which have an ethylenically unsaturated as essential constituents Compound, a photopolymerization initiator and

contain such a methacrylic acid polymer as a binder.

According to the teachings of the two references

the expert had to come to the conclusion that when using methacrylic acid polymers as

Only binders in photosensitive mixtures

development with aqueous-alkaline solutions but not with water alone is possible.

The object of the invention is therefore to create a photopolymerizable one that can be developed with water Mixture of the type specified at the beginning.

After extensive studies of various approaches to water developable photopolymerizable compositions using a number hydrophilic or water-soluble binder has now surprisingly been found that, if a relatively high molecular weight methacrylic acid polymer is used as a water-soluble resin in a photopolymerizable mixture, the resulting photosensitive Material can be developed with water so that

excellent pictures result.

The solution of this object of the invention is carried out according by creating a photopolymerizable water-developable mixture containing a Methacrylsäurepolymeres as a binder, an ethylenically unsaturated compound, boiling at atmospheric pressure over 100 ⁰ C and contains at least two ethylenically unsaturated groups per molecule, and a Photopolymerization initiator, which is characterized in that a 20% strength aqueous solution of the methacrylic acid polymer contained in the mixture has a viscosity of 5 to 30OPa-S at 25 ° C and that the mixture is based on 1 part by weight of methacrylic acid polymer 0.5 to 5 wt Contains parts of the ethylenically unsaturated compound.

The term "methacrylic acid polymer" denotes polymethacrylic acid and copolymers of methacrylic acid and other ethylenically unsaturated compounds, for example methyl methacrylate, methyl acrylate, styrene, butadiene, ethylene or propylene, in which the latter component is used in amounts that do not adversely affect the water developability of the photopolymerizable mixture Methacrylic acid polymers advantageously used within the scope of the invention must be suitable for forming an aqueous solution with a concentration of 20% by weight with a viscosity of 5 to 300 Pa · s at 25 ° C. and in particular from 30 Pas to 150 Pas. The photopolymerizable mixture containing the methacrylic acid polymer resin within the above! ' Contains viscosity range, for example, 1.7 parts by weight of trimethylolpropane triacrylate per part by weight of the polymer can be combined as an ethylenically unsaturated compound to improve the oleophilicity of the image area. Such a mixture provides a satisfactorily hard, non-adhesive layer when it is coated on the support, and is developable with water after imagewise exposure, the unexposed areas of the photosensitive layer being easily removed and an image of the photopolymerized water-insoluble photosensitive layer on the Bearer remains behind. An unexpected advantage of such a mixture is that the photosensitive layers are practically completely free of a tacky surface and this can be attributed to the markedly higher glass transition temperature (Tg) of the methacrylic acid polymer used due to its degree of polymerization, which is higher than that of other hydrophilic or water-soluble ones Resins (polymers) is, as can be seen from the table below:

Tg values in ° K of various hydrophilic

and water soluble polymers

bO

(from Polymer Handbook, 2nd edition, J. Brandrup et al., Wiley-Interscience Co. [1975]).

As stated above, the methacrylic acid polymer used in accordance with the invention can contain further ethy- lenisch unsaturated compounds, for example methyl methacrylate, methyl acrylate, styrene, butadiene or Ethylene copolymerized with it in amounts that

Polymethacrylic acid 501 Polyvinyl alcohol 358 Polyvinyl pyrrolidone 359 Polyethylene oxide 230 Polyacrylamide 379

Water developability of the mixture does not adversely affect the oleophilicity included to increase the photopolymerized layer.

In general, the other ethylenically unsaturated compounds listed above can be used in the mixture according to the invention in an amount of less than 30%, preferably less than 15%, specified as the ratio of the repeating units.

It is surprising that the as Binder layer containing a methacrylic acid polymer of such a high degree of polymerization, as in the case of the present invention, is nevertheless still water-developable if one takes into account that usually one has to choose low molecular weight binders in order to maintain good developability.

Another advantage of using the water-soluble methacrylic acid polymer described above is that the polymer is also in Soluble in alcohols, Faiis is a used binding agent! is insoluble in alcohols or other organic solvents, for example polyvinyl alcohol sharp limits on the nature of the polymerizable monomer and initiator to be used in the photopolymerizable mixture, and they must be dispersed in water. In contrast, the photopolymerizable mixture according to the invention based on the water-soluble methacrylic acid polymer can contain a large number of monomers and initiators, the transparent coating mixtures form, since the mixture is soluble in systems consisting only of an alcohol or an alcohol-water mixture

The according to the photopolymerizable compositions of the invention useful ethylenically unsaturated compounds do not have to have less than 100 ⁰ C at Atmosphärenriruck a boiling point and also have at least two polynerisie, br.re ethylenically unsaturated groups in the molecule. Examples of such compounds include monomers, prepolymers, for example dimers, trimers, tetramers and oligomers, ie polymers with a degree of polymerization of up to 10, mixtures thereof and copolymers thereof, ie with a degree of polymerization of up to about 15. Suitable examples of ethylenically unsaturated compounds include first of all acrylic and methacrylic esters, which specifically include polyacrylates and polymethacrylates of polyhydric alcohols, the term "poly" used here denoting a degree of polymerization not lower than two. Suitable polyhydric alcohols which can be used are alcohols having 2 to 20 carbon atoms, preferably 2 to 6 carbon atoms, and having 2 to 8 hydroxyl groups, preferably 2 to 6 hydroxyl groups. Specific examples of such polyhydric alcohols include

Ethylene glycols (ethylene glycol, diethylene glycol, triethylene glycol or tetraethylene glycol), Polypropylene oxides (propylene oxide, dipropylene oxide, tripropylene oxide, tetrapropylene oxide) or Polybutylene oxide, polycyclohexene oxide, Polyethylene oxide-propylene oxide, polystyrene oxide, Polyoxetane, polytetrahydrofuran, cyclohexanediol, Xy Iy lendiol, BiS - (^ 'hydroxyethoxy) benzene, Glycerine, diglycerine, tetramethylene glycol, Neopentylglycol.trimethylolethane,

Trimethylolpropan.Triäthylolpropane, pentaerythritol, dipentaerythritol, tripentaery thrite, tetrapentaerythritol, sorbitan, sorbitol, d-mannitol, butanediol, 1,10-decanediol, butanetriol, 2-butene-1,4-diol, 2-butyl-2-ethyl propanediol -Butyn-1,4-diol, 3-chloro-1,2-propanediol, 1, 'I-cyclohexanedimethanol, 3-cyclohexene-1,4-dimethanol, decalinediol, 23-dibromo-2-butene-1,4 diol, 2,2-diethyI-13-propanediol, 1 ^ -dihydroxy-i ^ A ^ tetrahydronaphthalene, 2,5-dimethyl-2E-hexanediol, 2i2-dimethyl-13-propanediol, 2 ^ -diphenyI-13-propanediol , Dodecanediol, mesoerithritol, 2-ethyl-1β-hexanediol, 2-ethyl-2- (hydroxymethyl) -13-propanediol, 2-ethyl-2-methyl-13-propanediol, heptanediol, hexanediol, 3-hexene-2 ^ 5 -diol, hydroxybenzyl alcohol, hydroxyethylresorcinol, 2-methyl-1,4-butanediol, 2-methyl-2,4-pentanediol, nonandio !, octanedio !, 1,5-Per.tap.dio !, 1-phenyl-l ^ -ethanediol, 13-PropaiuMol, 2,2,4,4-tetramethyl-13-cyclobutanediol, 23,5,6-tetramethyl-p-xylene-ix ^ ic'-diol, l, l, 4,4-tetraphenyl- 1,4-butanediol, lM ^ -tetraphenyl ^ -butyne-M-diol, le-trihydroxyhe xanJ, l'-Bi ^ -naphthoI, dihydroxynaphthalene, 1,1'-methylene-di-2-naphthol, 1,2,4-benzenetriol, biphenol, 2,2'-bis- (4-hydroxyphenyl) -butane , 1,1 -Bis - ^ - hydroxyphenylJ-cyclohexane, bis- (hydroxyphenyI) -methane _I catechin, 4-chlororesorcinol, 3,4-dihydoxyhydrocinnamic acid, hydroquinone, hydroxybenzyl alcohol, methylhydroquinone,

Methy! -2,4,6-trihydroxybenzoate, phloroglucinol, pyrogallol, resorcinol, glucose, «- (1 - Aminoethyl) -p-hydroxybenzyl alcohol, 2-amino-2-methyl-13-propanediol, 3 -. \ Mino-1,2-propanediol, N- (3-aminopropyl) -diethanolamine, N, N'-bis (2-hydroxyethyl) piperazine, 2,2-bis (hydroxymethyl) -2,2 ', 2 "-nitrilotriethanol, 2,2-bis (hydroxyniethyl) propionic acid, 13-bis (hydroxymethyl) urea, i (idl) hdil

(yy) N-butylethanolamine, diethanolamine, N-ethyl diethanolamine, 3-mercapto-1,2-propanediol, 3- piperidino-1,2-propanediol, 2- (2-pyridyl) -13-propanediol, triethanolamine, «- (1-aminoethyl) -p-hydroxybenzyl alcohol or ? · Amino-4-hydroxyphenyl sulfone, sorbitol and dipentaerythritol,

especially pentaerythritol are particularly preferred.

Acrylic acid and methacrylic acid esters of the above polyhydric alcohols are used in the context of Invention preferred, with preferred examples of such esters

Ethylene glycol diacrylate, Diethylene glycol dimethacrylate, Polyethylene glycol diacrylate,

wherein with polyethylene glycol triethylene glycol,

Tetraethylene glycol, pentaethylene glycol ... Tetradecaethylene glycol are designated, Pentaerythril tracrylate, Pentaerythritol dimethacrylate, Dipentaerythri tpentaacry lat, Glycerol triacrylate, diglycerol diniethacrylate,

13-propanediol diacrylate,

1,2,4-ButanetrioItrimethacryläi, I ^ -Cyclohexanediol diacrylate,

1,5-pentanediol diacrylate,

Neopentyl glycol diacrylate, Sorbitol diacrylate, sorbitol triacrylate,

Sorbitol tetraacrylate, sorbitol tetramethacrylate, ι ο Sorbi thexaacrylate or the triacrylate ester

of adducts from ethylene oxide

and trimethylol propane.

Another group of ethylenically unsaturated

Compounds include acrylamides and methacrylamides, and examples are methylene-bis-acrylamide, Methylene-bis-methacrylamide, the polyacrylamides or Polymethacrylamides, their amine components from ethylenediamine, diaminopropane, diaminobutane, penta methylenediamine, hexamethyl - ^ - bis ^ -aminopropyl) - amine, diethylenediamine, heptamethylenediamine, Octamethylenediamine, polyamides with carbon chains interrupted by heteroatoms, ring-containing Pclyaminde, for example phenylenediamine, xylylenedi- amine, ^ - (4-aminophenylethylamine, diaminobenzoic acid, diaminotoluene, diaminoanthraquinone or diaminofluorene are given.

Furthermore, various allyl compounds can be used. Examples of suitable allyl compounds include e.g. B. the diallyl esters of dicarboxylic acids, such as phthalic acid, terephthalic acid, sebacic acid, adipic acid, glutaric acid, malonic acid or oxalic acid, the Diallyesters or diallylamides of disulfonic acids, such as anthraquinone disulfonic acid, benzene disulfonic acid,

2 ^ -dihydroxy-p-benzene disulfonic acid, dihydroxynaphthalene disulfonic acid or naphthalene disulfonic acid.

Another group of ethylenically unsaturated compounds are the vinyl ether compounds and Examples include the polyvinyl ethers of those above described polyhydric alcohols. Suitable examples are ethylene glycol divinyl ether, 1,3,5-tri - ^ - viny! - oxyethoxybenzene, 13-di - ^ - vinyloxyethoxybenzene or Glycerol trivinyl ether.

Another group includes the vinyl esters and

Examples are divinyl succinate, divinyl adipate, divinyl phthalate, divinyl terephthalate, divinyl benzene-13-disulfonate or divinyl butane-1,4-disulfonate.

Another group includes the various styrene compounds and examples are divinylbenzoi,

so p-allyl styrene or p-isopropene styrene.

In addition, esters of itaconic acid and of the polyhydric alcohols indicated above can be used, 1,4-butanol diitaconate being suitable examples. Ethylene glycol diitaconate. Pentaerythritol diitaconate, dipentaerythritol taconate, dipentaerythritol pentaitaconate or dipentaerythritol hexa ^ taconate.

Modified acrylic acid esters, modified methacrylic acid esters, modified itaconic acid esters, arylated prepolymers, methacrylated prepolymers can also be used. use polymeric or itaconated prepolymers and examples include modified 1,4-butanediol diacrylate, modified trimethylolpropane acrylate, modified pentaerythritol triacrylate, methacrylated epoxy prepolymers or acrylated linear polyesters.

Other usable compounds than ethylenic Unsaturated compounds include N-Jj-hydroxyethyl - ^ - (methacrylamide) ethyl acrylate, N, N-bis - (^ - methacryloxyethyl acrylamide, allyl methacrylate and others

Connections made two or more by addition polymerizable ethically unsaturated bonds which are different from each other contain.

Such ethylenically unsaturated compounds listed above, which individually or in combination s can be used, are in the mixtures according to the invention in an amount of 0.5 to 5 parts by weight, preferably from 0.8 to 3 parts by weight, and more preferably 1 to 2 parts by weight per part by weight of the methacrylic acid resin. to

Various photopolymerization initiators known in the art can advantageously be used in the context of the invention and include those in J. Kosar, Light Sensitive Systems, Chapter 5, John Wiley & Sons, New York (1965), described r> materials such as carbonyl compounds, nitrogenous heterocyclic compounds and organic sulfur compounds, peroxides, redox compounds, Azo and diazo compounds, halogen compounds or photo-reducible compounds. Explanatory Examples include e.g. B. the following compounds: carbonyl compounds such as benzoin, benzoin methyl ether, Benzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert.-butylanthraquinone, 9,! 0-phenanthrenequinone, diacetyl, benzyl and compounds according to the following formula

wherein Ri is an alkyl group, which as corresponding Group in the usual cyanine dyes z. B. methyl, ethyl, propyl and other unsubstituted include lower alkyl groups, may be included, a hydroxyalkyl group, such as a 2-hydroxyethyl group, an alkoxyalkyl group such as a 2-methoxyphenyl group, a carboxyalkyl group such as a Carboxymethyl or 2-carboxyethyl group, a suI-foalkyl group, like a 2-sulfoethyl or 3-sulfopropyl group, and an aralkyl group, such as a benzyl, phenethyl, p-sulfophenethyl or p-carboxyphenethyl group, as well as a vinylmethyl group. R2 means an alkyl group, for example a methyl, ethyl, propyl or other lower alkyl group, an aryl group, for example a phenyl, p-hydroxyphenyl, p-methoxyphenyl, p-chlorophenyl or naphthyl group, as well as a thienyigruppe, Z means that to complete a heterocyclic, which is usually heterocyclic ring containing nitrogen atoms found in the usual cyanine dyes necessary non-metal atoms and includes, for example, benzothiazoles, e.g. B. Benzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 4-methylbenzothiazole, 6-methylbenzothiazoI, 5-phenylbenzothiazoI, 6-methoxybenzothiazole, 4-ethoxybenzothiazole, 5-methoxybenzothiazole, 5-hydroxybenzothiazole, 5,6-dimethylbenzothiazole or5,6-dimethoxybenzothiazole, naphthothiazoles, e.g. «-naphthothiazole or fi-naphthothiazole, Benzoselenazole, for example benzoselenazole, 5-chlorobenzoselenazole, 6-methylbenzoselenazole or 6-MethoxybenzoseIenazoL Naphthoselenazole. for example a-naphthoselenazole or / J-naphthoselenazole, Benzoaxazoles, for example benzoxazole, 5-methylbenzoxazole, 5-PhenyIbenzoxazoI or 6-methoxybenzoxazole, naphthoxazoles, for example «-naphthoxazole or ^ -naphthoxazole.

Typical examples of compounds represented by the above general formula include, for example

2-benzoylmethylene-3-methyl - /? - naphthothiazoline, 2-benzoylmethylene-3-ethyl-0-naphthothiazoline,
3-ethyl-2- (2-tert-hexoyl) -methylene-0-naphthothiazoline,

3-ethyl-2-propionylmethylene / 3-naphthothiazoline or
S-ChlorO-ethyl ^ -p-methoxybenzoylmethylene-benzothiazoline.

Suitable nitrogen-containing heterocyclic compounds include acridine derivatives, such as. B.

9-phenylacridine, 9-p-methoxyphenylacridine,

Phenazine derivatives, such as

9, IO-dimethylbenz (a) phenazine,

9-methylbenz (a) phenazine or

10-methoxybenz (a) phenazine,

Quinoxaline derivatives such as

6,4 ', 4'-trimethoxy-2,3-diphenylquinoxaline

or4 ', 4'-dimethoxy-2,3-diphenyl-

5-azactiiiioxalin,

^Quinazole: i <ierivate, such as 2-methylquinazoline

or 4-phenylquinazoline,

Imidazole derivatives such as

2,4,5,2 ', 4', 5'-hexaphenyl-l, r-biimidrzole.

Suitable examples of usable organic sulfur compounds include di-n-butyl disulfide, din-octyl disulfide, Dibenzyl disulfide, diphenyl disulfide, di-

Jj benzoyl disulfide, diacetyl disulfide, 2-mercaptobenzothiazole, 2-mercaptobenzoaxazole, 2-mercaptobenzimidazole, thiophenol, thiocresol, p-methoxybenzenethiol, Carboxymethyl-N.N-dimethyldithiocarbamate, ethyl trichloromethanesulfonate and similar connections.

Suitable examples of usable peroxides include hydrogen peroxide, di-terL-butyl peroxide, Benzoyl peroxide or methyl ethyl ketone peroxide.

Redox compound systems include combinations of a peroxide and a reducing agent and suitable examples include iron (H) ions and hydrogen peroxide, iron (II) ions and persulfate ions, Iron (III) ions and peroxide or iron (III) ions and persulfate ions.

Azo and diazo compounds include "A'-azo-bisisobutyronitrile, 2-azo-bis-2-methylbutyronitrile, 1-azobis-cyclohexanecarbonitrile or p-aminodiphenylamine diazonium salt.

Halogen compounds include chloromethylnaphthyl chloride, phenacyl chlorides, chloroacetone, ^ -naphthalenesulfonyl chloride, or xylene sulfonyl chloride.
Photoreducible dyes include

Rose bengal (CI 45 440),
Erythrosine (CI 45 405.45 425.45 430),
Eosin (CI45 380.45 400.45 410),
Acrylic flavin (CI 46 ΟΟΟχ
Riboflavin (Vit B ₂ ) or
Thionine (CI52 52025).

Among the compounds listed above, one or more compounds can be used as photopolymerization initiators can be used.

These photopolymerization initiators are used in an amount of 0.1 to 10, particularly 0.5 to 17

60

Parts by weight, based on 100 parts by weight of the used Ethylenically unsaturated compound used.

A thermal polymerization inhibitor can also be used in the photopolymerizable, photosensitive Mixtures are incorporated according to the invention, which are basically those listed above Contain ingredients. Specific examples of thermal photopolymerization inhibitors include e.g. p-methoxyphenol, hydroquinone, alkyl- (e.g. with I to 5 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, isopropyl, Isobutyl-. Isopentyl or sec-butyl groups) or aryl-substituted hydroquinones, tert-butyl catechol, pyrogallol, Copper (l) chloride, phenothiazine, chloranil, naphthylamine, ^ -naphthol, 2,6-di-tert.-butyl-p-cresol, Pyridine, nitrobenzene, dinitrobenzene, p-toluidine, methylene blue, copper salts of organic acids, for example Copper acetate or copper oxalate. Such thermal polymerization inhibitors are used in one area from 0.001 to 5 parts by weight per 100 parts by weight of the ethylenically unsaturated compound used applied.

The photopolymerizable, photosensitive mixtures according to the invention can also contain additional Contain additives such as coloring agents, plasticizers and resinous materials.

Suitable examples of coloring agents include pigments, such as. B. titanium oxide, carbon black, iron oxide, phthalocyanine derivatives or azo compounds and dyes, such as methylene blue (CI 52 015, 52 030), crystal violet (Cl 42 5jä, 42 557), rhodamine B (Cl 45 170), fuchsine (CI 42 500, 42 510, 42 520, 42 685), auramine (Cl 41000, 41 005), azo dyes or anthraquinone dyes. Of these materials, those that do not have light in the through the photopolymerization initiator absorb absorbed area, preferred. These colorants can range from 0.1 to 10 Parts by weight for pigments and from 0.01 to 10 parts by weight for dyes per 100 parts by weight of the Total amount of methacrylic acid resin and ethylenically unsaturated compound can be used. A more preferred range for both pigments and dyes is 0.1 to 3 parts by weight.

Suitable plasticizers that can be used include phthalates such as

Dimethyl phthalate, diethyl phthalate,
Dibutyl phthalate, diisobutyl phthalate,
Diheptyl phthalate, dioctyl phthalate,
Octyl capryl phthalate, dicyclohexyl phthalate,
Ditridecyl phthalate, butyl benzyl phthalate,
Diisodecyl phthalate or diallyl phthalate,
Glycol esters, such as dimethyl glycol phthalate,
Ethyl phthalyl ethyl glycolate,
Methyl phthalyl ethyl glycolate,
Butyl phthalyl butyiglycolate or
Triethylene glycol dicaprylate,
Phosphate esters such as tricresyl phosphate or
Triphenyl phosphate

Esters of aliphatic dibasic dicarboxylic acids, such as

Diisobutyl adipate, dioctyl adipate,
Dimethyl sabecate, dibutyl sebacate,
Dihexylazelate, dioctyllazelate or
Dibutyimaleate, triethyl citrate,
Tributyl triacetate, glycerol triacetate,
Butyl laurate or bis (2-ethyhexyl) -4,5-epoxycydohexane-1,2-dicarboxy lat

The suitable amount of plasticizer can be less than 30% by weight, preferably less than 10% by weight, based on the total weight of methacrylic acid resin and ethylenically unsaturated compound.

About the effect of the oxygen in the air on photopolymerization during imagewise exposure of the photosensitive material using the photopolymerizable mixtures according to

ίο invention suppresses, reduce, can be higher aliphatic carboxylic acid with 18 or more carbon atoms in the photopolymerizable mixture in in a range of 0.1 to 5%, based on the weight of the photopolymerizable mixture are incorporated

ii the. Suitable examples of higher aliphatic Carboxylic acids include stearic acid, arachidic acid, heneicosanoic acid, behenic acid, tricosanoic acid, lignoceric acid, Pentacosanoic acid, cerotic acid, heptacosanoic acid, octacosanoic acid, montanic acid, melissic acid or Lacceric acid, of which those acids having not less than 20 carbon atoms which are those above with the exception of stearic acid, are preferred.

The photopolymerizable mixtures according to

2> invention will generally be in a suitable Solution system dissolved to form a coating solution, on a suitable support, such as a plate, a cardboard box or film made of glass, wood, paper, cloth, metal, e.g. B. aluminum, zinc, copper, iron,

jo nickel, chromium or Fe-Cr-Ni alloys are formed, or on a cloth, a synthetic film, for example made of polyethylene terephthalate, polyamide, polyethylene, polypropylene, cellulose triacetate or the like Materials raised and dried to that

y to obtain coated recording material. The thickness of the photopolymerizable layer varies depending on the end use of the recording material, in particular exemplary coating thicknesses for the photopolymerizable mixture are a thickness of 0.5 μm to 10 μm for an offset printing plate, a thickness of 40 μm to 1 mm for a photoresist letter press printing plate and a thickness of 0.5 μπι to 50 μπι for a resist of general utility.

Suitable solvents usable for the production of such coating solutions include alkanol having 6 or less carbon atoms and having boiling points not higher than 160 ⁰ C, for example 40 ° C to 160 ° C. Examples of such alkenols are

Methanol, ethanol, propanol, butanol, pentanol, hexane, Isopropyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, selc-amyl alcohol, tert-amyl alcohol, 3-pentanol, isohexyl alcohol, 2-hexanol or 3-hexanol. These alkanols can be used individually or in combination. From these alcohols propanol, butanol, isopropyl alcohol, isobutyl alcohol and selc-butyl alcohol are most preferred Mixtures of such alkanols with water can also be used as solvents for the photopolymerizable Mixtures according to the invention are used. Preferred combinations are propanol / Water, butanol / water, isopropyl alcohol / water, isobutyl alcohol / water and set-butyl alcohol / water. Furthermore, other organic solvents, such as

it organic solvents! with a high polarity, for example acetone, methyl ethyl ketone, / S-hydroxyethyl methyl ether, jJ-hydroxyethyl ether, N, N-dimethylformamide or dimethyl sulfoxide to these solvents

system can be added within the range where the advantageous features of the present Invention not be adversely affected.

If the water-developable, photopolymerizable light-sensitive mixtures according to the invention in an alkanol or an alkanol / water mixture containing solvent system are dissolved, the result is goods, homogeneous solutions. These Homogeneity of the solutions containing the photopolymerizable mixtures according to the invention, the being one of the embodiments of the present invention provides several advantages.

These advantages include the ease with which the mixture can be made, a long shelf life of the solution after preparation, the ease with which the photosensitive solution of the Mixtures can be applied to a carrier and ensure complete uniformity of the applied photosensitive mixtures on the support.

If a photosensitive material with the photopolymerizable mixture according to the invention is used to make a photoresist, the photohardened resist image can easily be subsequently applied an etching process with an aqueous solution containing a strongly alkaline agent such as potassium hydroxide, sodium hydroxide, Contains sodium phosphate or potassium phosphate in a concentration of 2 to 20% by weight, be removed, this alkaline solution on the support at a temperature in the range from 15 ° C to 90 ° C is applied.

The following examples serve to further illustrate the invention. Unless otherwise stated, all parts, percentages and ratios are by weight.

example 1

A degreased aluminum plate (aluminum 98.8%, manganese with a thickness of 0.24 mm was cleaned with a polyamide brush, and then the surface of the plate was subjected to anodic oxidation by immersing the plate in dilute sulfuric acid at a concentration of 20% by weight. of 30 ° C. while passing through an electric current with a current density of 3 A / dm ² for 2 minutes C. for 1 minute After the plate was rinsed with water and dried, the following photosensitive mixture was coated on the plate to a dry thickness of 3 microns

Parts by weight Polymethacrylic acid Viscosity 125 Pa · s at 25 ° C (aqueous solution with 20% by weight) 10 n-butyl alcohol 40 Trimethylol propane triacrylate 24 Diheptyl phthalate 1 N-methyl-2-benzoyimethylene /? - naphthothiazole 0.1

Tap water (35 ° C), immersed for 1 minute and rubbed lightly with a sponge to remove the non-image areas. The thus obtained Printing forme was set in a printing machine and 20,000 copies of excellent quality without Lacquer formation manufactured.

Example 2

The same results were obtained practically by repeating the same procedure as in Example 1 but using the following photosensitive mixture:

The coated plate was left at 50 ° C overnight held and then pictorially at a distance of 50 cm with a 2 kW high-voltage mercury! amps 30 Seconds after which the exposed plate is exposed in

Example 3 Parts by weight Polymethacrylic acid (as in example I) 10 n-butyl alcohol 40 Pentaerythritol tetraacrylate 2.5 Diheptyl phthalate I. N-methyl-2-benzoylmethylene j3-naphthothiazole 0.1

The same results were also obtained using practically the same procedure as in Example 1 was repeated, but using the following photosensitive mixture:

Parts by weight Polymethacrylic acid (aqueous solution according to Example 1) 10 n-butyl alcohol 40 Trimethylolpropane trimethacrylate 2.5 Diheptyl phthalate 1 Michler ketone 0.08 Benzanthrone 0.04

Example 4

A copper substrate for a printing circuit was made photosensitive after polishing with the following Coating mixture coated to a dry thickness of 5 microns

Parts by weight

Polymethacrylic acid 10 (as in example 1) 40 n-butyl alcohol 3.5 Trimethylol propane triacrylate N-methyl-2-benzoylmethylene 0.08 /? - naphthothiazole Lophine dimers (2,4,5,2 ', 4', 5'-hexaphenyl- 0.04 l.l'-biimidazole)

After drying, imagewise exposure was carried out as in Example 1. The plate was then in immersed tap water heated to 35 ° C for 1 minute and weakly with a piece of sponge rubbed. Then the copper at the non-image area was etched by brushing the plate with an aqueous FeCb solution was sprayed with 40 wt .-% (40 ° C), so that the organic layer in the exposed areas resisted the etchant and in this way good as Etch resist was worked out. Finally, the resist coating was easily removed by dipping the board in an aqueous sodium hydroxide solution of 25 ° C with 5 wt .-% removed

Claims (8)

Patent claims: 1. Photopolymerizable, water-developable mixture, containing a methacrylic acid polymer as a binder, an ethylenically unsaturated compound which boils at normal pressure above 1000 ⁰ C and contains at least two ethylenically unsaturated groups per molecule, and a photopolymerization initiator, characterized in that a 20% aqueous solution of the methacrylic acid polymer contained in the mixture has a viscosity of 5 to 300 Pa · s at 25 ° C. and that the mixture contains 0.5 to 5 parts by weight of the ethylenically unsaturated compound per part by weight of methacrylic acid polymer. 2. Mixture according to claim I _1, characterized in that it additionally contains an alkanol with a content of not more than 6 carbon atoms or a mixture of water with an alkanol with not more than 6 carbon atoms as a solvent 3. Mixture according to claim 2, characterized in that the alkanol is selected from methanol, ethanol, Propanol, butanol, pentanol, hexanol, isopropyl alcohol, isobutyl alcohol, selc-butyl alcohol, tert-butyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 3-pentanol, isohexyl alcohol, 2-hexanol and / or 3-hexarol 4. Mixture according to claim t, characterized in that the aqueous solution of the methacrylic acid polymer has a viscosity of 30 to 150 Pa-s 25 ° C. 5. Mixture according to claim 1 or 4, characterized in that the methacrylic acid polymer is a copolymer of methacrylic acid and a further ethylenically unsaturated compound that is copolymerizable therewith, in which the ethylenically unsaturated compound in the copolymer is in an amount of less than 30%, expressed as the ratio of the units recurring therein, is present. 6. Mixture according to one of claims 1 to 5, characterized in that the ethylenically unsaturated compound of an acrylic or methacrylic ester with a polyhydric alcohol, a Acrylamide or methacrylamide, an allyl compound, a vinyl ether, a vinyl ester, a Styrene compound, an itaconic acid ester with a polyhydric alcohol or derivatives thereof consists. 7. Mixture according to one of claims 1 to 6, characterized in that the photopolymerization initiator consists of a carbonyl compound, a nitrogen-containing heterocyclic compound, an organic sulfur compound, a peroxide, a redox compound, an azo or Diazo compound, a halogenated organic compound or a photo-reducible compound. 8. Mixture according to one of claims 1 to 7, characterized in that the mixture additionally contains a thermopolymerization inhibitor.