DD210360A1 - LIGHT-SENSITIVE, POSITIVELY WORKING COPIER MATERIAL - Google Patents

Abstract

The invention relates to a photosensitive, positive-working copy material for photolithographic production of printing plates, consisting of a polymer, an olefinic monomer and a photodimer of anthracenes, azinium anthracenes or azaanthracenes. The imagewise exposure leads to cycloreversion of the photodimers and subsequent thermal Diels-Alder reaction between the photogenerated anthracene, azinium anthracene or azaanthracene derivatives and the olefinic copying material component. The resulting depletion of olefinic material in the exposed areas only leads to a hardening of the unexposed areas during the subsequent heat treatment. The addition of polymerization initiators and crosslinkers intensifies the hardening effect. Final development with suitable solvents leads to the production of positive relief images which are used as etching protection layers, printing forms or the like. can be used.

Description

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Photosensitive, positive working copy material. Field of application of the invention

The invention relates to a photosensitive, positive-working copy material which is suitable for the production of printing plates.

Characteristic of the known technical solutions

For the preparation of photosensitive copying materials which are suitable for the preparation of printing plates, photosensitive substances or mixtures of substances are used, which work either negatively (light-curing) or positively (light-softening). For the photochemical production of printing plates, it is irrelevant in the sails whether the copy material works positively or negatively, since, depending on the desired printing technique, the original can be selected as positive or negative. For this reason, both negative and positive working materials are currently used in practice. The negative working materials are based on photopolymerization. Selected polymers, oligomers, polymer-monomer or polymer-oligomer mixtures are light-cured (W. KÖNIG, W. SOBSK and H. TEAÜZEDDSL, Mitteilungsbl. Ghem. Ges. DDR 1981, £ 6 _} 121).

The positive-working copying materials exploit the fact that intermolecular interactions take place between o-naphthoquinonediazides and novolaks, which bring about a reduction in the alkali solubility of the novolak. The photochemical

.-, - η ο α Q Q Π

Decomposition of the o-quinonediazide embedded in the novolak to give corresponding indenecarboxylic acids results in the preparation of the original alkali solubility characterizing the pure polymer (J. KOSAR, Light Sensitive Systems, Chemistry and Application, Nonsilver Halide Photographic Processes, John Wiley & Sons, New York-1965 J. Photogr. Sci. 1971, V8, 88). These positive-copy materials are characterized in that their photosensitivity can not or only insignificantly increased by sensitizers, and that the production of sufficiently thick photosensitive thicker positive layers is difficult or impossible because of the inherent strong layer thickness dependence of the necessary exposure time. ,

A general goal of printing plate making is the development of systems that work with materials that can be exposed directly in the camera due to sufficient photosensitivity. Sine such work technique requires not only the use according sensitive materials, for most application issues (tone quality natural templates) is also necessary Dais ^this: materials work positively. Furthermore, printing plates produced by photolithography by coating, exposure and developing are subject to high mechanical requirements. The wear of such printing plates can be significantly reduced if they are thermally or photochemically cured in the connection to the photolithographic processing.

Object of the invention.

The aim of the invention is to provide a light-sensitive, positive-working copying material comprising a ^Removing. Having extensive film thickness and high photosensitivity curable thermally and thereafter is mechanically stable and is suitable for a photolithographic production of printing forms, - .- ''

Explanation of the essence of the invention

The invention has for its object to develop a photosensitive, positive-working copy material which is insoluble in unexposed areas and thermally curable, soluble in exposed areas and imagewise exposure and downstream hardening and development process results in a printing plate with a clear picture. In accordance with the invention, the object is achieved by dissolving the mixture in one solvent or mixture of one or more polymers, one or more olefinic monomers and one or more photodimers of anthracenes, azinium anthracenes and / or azaanthracenes suitable backing, such as a metal foil, quartz, silicon or silica spun on or cast to a self-supporting layer.

As polymers, materials are used which have been obtained as a result of free-radical or ionic polymerization or copolymerization of olefinic monomers. For this purpose, preference is given to using polyacrylic acid and / or derivatives, polymethacrylic acid and / or derivatives or "poly-styrene" and / or "derivatives which are known to form transparent films and layers the monomers corresponding to the polymers used, such as acrylic acid and / or derivatives, methacrylic acid and / or derivatives, styrene and / or derivatives or vinyl ethers or oligomers of said monomers with a high olefinic content For adequate curing of the layers within a short time the addition of olefinic crosslinkers is advantageous, such as divinylbenzene, allyl acrylate or methacrylate, glycol dimethacrylate or cinnamic allyl ester.- The photodimers used are anthracene (I), aziniumanthracene (HV) or azaanthracene derivatives (VT, VTI) where E = alkyl, branched Alkyl, unsubstituted or substituted aryl and L and M linear and / or angularly condensed arene and / or heteroarene, Z is hydrogen or one or more identical or different substituents in possible

Ürnrn

Positions, preferably for alkyl, aryl, substituted aryl, OE with the meaning given for R, halogen, NO ₂ or CN. X "" represents an anion, for example a halide, perchlorate, Te met luorobor at, tetraphenylboranate, tosylate, picrate, TCHQ "or OH". If desired, a polymerization initiator, in particular dibenzoyl peroxide or azo-bis-isobutyronitrile, is added to the mixture of these components. The mixture is dissolved in a suitable solvent, in particular in an alcohol, nitrile, ketone, aliphatic or aromatic hydrocarbon, halohydrocarbon, ester or ether, or in a mixture of at least two of these solvents. Depending on the solvent viscosity j of the concentration and the spinning speed (n = 2000 to 8000 min "), spin-on layers of thickness 1 to 150 μm are obtained and the material is exposed imagewise. Suitable beam sources for this are HBO, XBO, XHB or NBO lamps. A special filtering of the excitation light is not necessary, with shorter-wave excitation (λ <350 im): but becomes a higher; Reaction rate observed. .

The oildmäsige exposure leads to the cyclare version of the photodimers used to form the monomers YIII-XIY with the meanings given for R, Z, L, M and X. "The photochemically formed anthracenes, aziniumanthracenes and azaanthracenes react as dienes with the olefins in the form of a ( 4 + 2) -Cycloddition to Diels-Alder adducts.This (4 + 2) cycloaddition proceeds thermally.In the course of the Diels-Alder reaction, the layer is depleted at: formerly exposed sites: olefinic fraction and In the subsequent heat treatment, graft polymerization and crosslinking increase the degree of polymerization only at unexposed areas, as a result of which the solubility decreases dramatically in these layer areas, and the material here is practically insoluble when appropriately heat-treated.

When dipping in the solvents used for dissolving the mixture or those of similar structure and thus.

The exposed sites, consisting of soluble starting polymers or oligomers as well as Diels-Alder adduct, are washed out, and unexposed areas remain unaffected in this process. The thus treated positive relief image material is dried. Particularly suitable compositions of the mixture used are: polyacrylic acid or polymethacrylic acid derivatives, preferably polymers or copolymers of acids or methyl esters as polymer constituent, acrylic acid, methacrylic acid or its methyl ester as olefinic monomers, glycol dimethacrylate or methacrylic allyl ester as crosslinker, dibenzoyl peroxide or azo-bis-isobutyronitrile as a polymerization initiator and acridizinium perchlorate diaer, 9-methylacridizinium perchlorate diamine, acridizinium bromide diacid, benz [b] acridizinium tosylate dimer or N-methylbenzo fg / quinolinium. tetrafluoroborate dimer as photodimers.

The material according to the invention is characterized by a high stability against mechanical loads (pressure, abrasion) and surprisingly corresponds to the requirements for a printing plate production. It also owns. greater layer thickness ^{: a} high photosensitivity. That- * positive relief image obtained mit'die- 'sem material, the template is clear, it is to all downstream operations such as printing operations due to the good surface adhesion stable.

embodiments

example 1

75 g of polymethylmethacrylate (average molecular weight approx.

20,000),

12 g of acrylic acid,

10 g of acridizinium perchlorate dimer,

2.9 g of allyl methacrylate, 0.1 g of dibenzoyl peroxide

are dissolved in chloroform / chlorobenzene / o-dichlorobenzene (2: 10: 1) and on a mechanically roughened aluminum surface

on ge spin (η = 4000 min ""}. The layer thickness was 5 mm. The sufficiently dried material was irradiated for 20 s with the unfiltered light from a 250 W photoflood lamps. The mixture was then annealed for 30 min at 80 ⁰ C. The positive image was developed by dipping in chloroform / methylene chloride (1: 1) and dried in air.

Example 2

80 g of a 1: 1 copolymer of methyl methacrylate and methacrylic acid (average molecular weight about 20,000), 8 g of acrylic acid,

11.9 g of 9-methylacridizinium perchlorate dimer, 0.1 g of azo-bis-isobutyronitrile

are solved analogously to Example ¹ , centrifuged on ge, exposed and developed.

Example 3

70 g of a 1: 1 copolymer of methyl methacrylate and methacrylic acid (average molecular weight about 20,000), 8 g Methacrylsäurey ''.

10 g glycol dimethacrylate, 11.9 g acridizinium bromide dimer, 0.1 g dibenzoyl peroxide

are in chloroform / Ohlorbenzen / o-dichlorobenzene. (2: 10: 1) solved, and. to, a · film-the layer thickness ;. 100 Hm. Shed. The air-dry material was irradiated for 130 s with the filtered light (interference filter 31 3 ma) of an HBO 500. Connecting-Bend was tempered at 80 ⁰ C for 30 min. The positive image was developed by dipping in chloroform / methylene chloride (T: V) (1 min.) And dried in air. The etching depth observed at the exposed areas was about 50 μm.

Example 4. -

70 g'.polymethyl methacrylate,, _;

12 g of acrylic acid,.

14 g of Benz ["b] acridizinium tosylate dimer

3.9 g of p-divinylbenzene, 0.1 g of azo-bis-isobutyronitrile

be solved analogously to Example 3, potted, exposed (.Interferenzfilter 365 ma), annealed and developed. The etching depth observed at the exposed areas was about 70 / im.

Example 5

75 g of a copolymer of methacrylic acid / styrene (2: 1) (average molecular weight about 12,000),

5 g of acrylic acid,

6 g of itf-methylstyrene,

13.9 g of N-methylbenzo [g] quinolinium tetrafluoroborate dimer, 0.1 g of AzQ-bis-isobutyronitrile

be solved analogously to Example 3, potted, irradiated (interference filter 333 nm), annealed and. The etching depth observed at the exposed areas was approximately 40 km *

"Nc" αQO * 09.fi380

XE

,, ι η ιη, ι.ι, ηηίί ΟΟΛ

Claims (2)

Srfindungsanspruch 1. Photosensitive, positive-working. Copy mass for photolithographic production of printing plates, characterized in that da.3 a mixture consisting of one or more polymers and / or oligomers, preferably polyacrylic acid and / or derivatives, polymethacrylic acid and / or derivatives, polystyrene and / or derivatives, with a weight proportion of 50 to 95%, preferably 70 to 80%, and one or more '* olefinic ^ Monomerehy preferably acrylic acid and / or derivatives, derivatives of methacrylic acid and / or styrene and / or derivatives or vinyl ethers, or oligomers of the above Monomers with a high olefinic content, with a weight fraction of 4 to 40%. preferably 10 to 15%, and one or more photodimers; of anthracene, azinium anthracene or azaanthracene derivatives of the general formulas I-YII in which R = alkyl, branched alkyl, unsubstituted or substituted aryl and L and M linear and / or angularly condensed arene and / or a heteroarene system, where Z is hydrogen or . glei'che one or more - or "ver send var ous sub ^st: ituent s in Moegli chen-items, preferably represents alkyl, aryl, substituted aryl, OE with the specified importance for e, halogen, NO2 or ClT and X ~ an anion, for example a halide, perchiorate, tetrafluoroborate, tetraphenylboranate, tosylate, picrate, TCHQ.sup.- or OH.sup.-, with ^{1: 1} wt% of 1 to 20%, preferably 10 to 15%, of 1 and 1% of olefin Polymerization crosslinker, preferably divinylbenzene, allyl acrylate or methacrylate, glycol dimethacrylate or cinnamyl allyl ester, with a wt .-% content of up to 10%, and optionally a polymerization initiator, in an alcohol, nitrile, ketone, ester, ether, aliphatic or aromatic hydrocarbon or halogenated hydrocarbon or dissolved in a mixture of at least two of these solvents, the solution spun onto a suitable surface or a self-supporting layer is prepared by pouring the solution; th, films or foils with light, in particular von'Foto-, HBO, XBO, XHB or NBO lamps, optionally with the interposition of a filter are irradiated imagewise, then exposed material by annealing at 50 to 100 ⁰ C, preferably at SO ⁰ C, at unexposed places. cures, subsequently imagewise exposed areas of this material by immersion in the same solvent or mixture used to dissolve the mixture or in a Lö- _; ; solvent or mixture with similar dissolving properties or, by rinsing with such leached and das'Material is finally dried. " 2. Copying material according to item 1, characterized in that the mixture in particular polyacrylic acid or Ppropmethacrylsäurederivate., Ν preferably polymers or copolymers of acids or methyl esters, with a weight fraction of preferably 70 to 80 % as a polymer component, acrylic acid, methacrylic acid or its methyl ester as olefinic : Monomers, glycol dimethacrylate or allyl methacrylate, as crosslinker and dibenzoyl peroxide. or azo-bis-isobutyronitrile, oil polymerization initiator; 5. Copying material according to items 1 and 2, characterized in that the mixture as photodimer component is preferably acridizinium perchlorate dimer, 9-methylacridizinium perchlorate dimer, acridizinium bromide dimer, benzyl b] acridizinium tosylate dimer or H-methylbenzoyl- quinolinium tetrafluoroborate Contains dimer with a weight fraction of preferably -10 to 15%. For this purpose, see Sefe Formein