JPS592045A - Preparation of print plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the halogen-based surface treatment of flexographic printing plates having a photosensitive layer containing a butadiene/acrylonitrile copolymer. More particularly, the invention relates to the surface treatment of photosensitive layers containing butadiene/acryl copolymers with bromine or iodine followed by chlorine and the products produced thereby.

Photosensitive flexographic printing plates have achieved considerable demand in the printing industry. Compositions particularly useful in the production of such flexographic printing plates include addition polymerizable ethylenically unsaturated compounds, photoinitiators and block copolymers such as styrene-butadiene-styrene as polymer binders. Examples include compositions containing a histyrene-isoprene-styrene conjugate or a butadiene/acrylonitrile polymer that optionally contains a carboxyl group. Printing plates using compositions containing the block copolymers described above are generally compatible only with alcohol or alcohol-acetate based inks. On the other hand, butadiene/acrylonitrile polymers, which optionally contain p-carboxyl groups, are generally compatible only with hydrocarbon-based inks.

7 Containing Styrene-Butadiene-Styrene Matahastyrene-Isoprene-Styrene Block Copolymer Binder
Lexographic printing plates, for example after imagewise exposure and development through a process transparency, are generally treated with an acidic hypochlorite solution to reduce the tackiness of the layer. Reduction of tack can also be achieved by the use of bromine solutions. However, neither chlorination nor bromine treatment makes these block copolymer-based printing plates compatible with hydrocarbon-based inks.

However, flexographic printing plates containing butadiene/acrylonitrile polymers, which optionally contain carboxyl groups, are not only sticky but also contain certain solvents and other components present in some printing inks, such as alcohols, acetates, etc. They are susceptible to attack by others, and therefore the use of these plates is limited to limited liver inks containing 5Ii amounts of hydrocarbon solvents. The use of chlorine-containing solutions, such as hypochlorous acid solutions, may reduce tackiness but prevent the printing narrow side of the printing plate from being attacked by inks containing alcohol and other solvents of the glaze. Butadiene/acrylonitrile polymer-containing flexographic printing plates are post-exposed (total non-imagewise exposure performed after imagewise exposure)
shows increased solvent resistance for all inks when treated with an aqueous solution having a free bromine concentration before or after
and most notably increased resistance to alcohol-containing inks and various other non-hydrocarbon solvents. However, this improvement is insufficient for practical use when the alcohol-containing ink also contains high levels of acetate esters or other aggressive co-solvents.

Chlorination introduced for tack reduction does not increase resistance and may decrease it. This improvement is also not observed upon chlorine or bromine treatment of printing plates containing styrene-isoprene-styrene or styrene-butadiene-styrene block copolymers.

Flexographic printing plates containing styrene-imprene-styrene, styrene-butadiene-styrene block copolymers and flexographic printing plates containing butadiene/acrylonitrile copolymers optionally containing carboxyl groups are detackified by iodine treatment and Provided with increased resistance to "photo-induced post-curing". It is not known whether iodine treatment improves solvent resistance for printing plates made from photosensitive compositions containing a butadiene/acrylic acid Lμ Hongjong association, which optionally contains dicarboxyl groups. improved compatibility with inks, ink solvents and co-solvent spectra (e.g. Eva-alcohol, alcohol-acetate, hydrocarbon, alcohol-hydrocarbon, alcohol-water, etc.) currently available to those skilled in the art. A need exists for a 2-halogen treatment process.

Two more types of halos? There also exists a need for a process in which bromine and chlorine or iodine and chlorine are applied sequentially and can be carried out before or after post-exposure.

Furthermore, there is a need for a process for the immediate 2-halogen treatment of aqueous developed printing plates without the need for drying.

According to the present invention, the acrylonitrile having a number average molecular weight of 20,000 to 75,000 and having an acrylonitrile content of 10 to 75,000
50% by weight of acetic acid and a high molecular weight butadiene/acrylonitrile copolymer having a carboxyl content of 0 to 15% by weight and a non-gaseous ethylenically unsaturated compound containing at least one terminal ethylene group. For imparting a modified solvent-resistant surface to a relief photosensitive flexographic printing plate in which the relief areas are produced by imagewise exposure of the elastomeric composition layer to actinic radiation and liquid development of the unexposed areas thereof. A method is provided which, optionally after drying the portion in relief, comprises, in any order: (1) post-exposing the developed surface to a source of actinic radiation; 2) This developed surface is continuously treated with a 2-layer aqueous solution, i.e., an aqueous solution with QJ contact for about 15 seconds to 20 minutes, having a concentration of 0.01 to 6.5% by weight of free bromine. or 0.2 ~
The first halogen is either an aqueous solution with a contact time of 1.0 to 10 minutes with a free iodine concentration of 10% by weight.
solution and subsequent 0.01-1.0 molar N
hOcL and HC of 0.012 to 1.2 mono 1 strain degree
1 of the aqueous solution for a contact time of about 15 seconds to 5 minutes.

The photosensitive composition used in the method of the invention includes a high molecular weight butadiene/acrylonitrile copolymer, a non-gaseous ethylenically unsaturated compound, an organic radiation-sensitive free radical-generating photoinitiator or photoinitiator system, and as discussed below. and other additives. The composition can be used in the form of a layer, or a layer of the composition can be adhered to a flexible support or a temporary support can be used.

Useful flexible supports include plastic films and metal sheets, open or closed cell ohms, flexible rubber layers, or combinations of foam and rubber layers with plastic films.

When a combination support is used, the plastic film is generally adjacent to the photosensitive layer. Examples of such supports include monopolymer films such as polyethylene terephthalate, flame-treated polyethylene terephthalate, electron discharge treated polyethylene terephthalate, polyethylene terephthalate, polymeric films, etc., such as U.S. Pat. No. 3,179,634, incorporated herein by reference. and thin metal sheets such as aluminum, tin-plated steel (brushed or glossy). The polymeric support generally has a thickness in the range of 0.001 inch to 0.00 inch (0.025 to 0.18 inch). The metal support is generally 0.0% for aluminum.
010~0.0115 inch (0.25~0.29m)
, and 0.008~o for anchored steel,
The thickness ranges from 0.20 to 0.25 mm. Examples of foam supports include open and closed self-containing foams such as polyvinyl chloride, polyurethane,
Examples include ethylene polyene diene rubber, neoprene, and others.

Examples of compressible combs include styrene/isoprene block copolymers, butadiene/acrylonitrile copolymers, natural rubber, and others.

The photosensitive compositions disclosed herein are developable in their unexposed state in aqueous, semi-aqueous basic or solvent solutions depending on the carboxyl content of the polymeric binder component of the photosensitive composition. This photosensitive layer is 0.005 to 0
．． Thickness ranges from 250 inches (approximately 0.13 to 6.35 m) or greater.

One essential component of the photosensitive elastomeric composition is about 20
,000 to about 75,000, preferably about 25,000,
Number average molecular weight (Mn) ranging from 000 to about 50,000
) is a high molecular weight butadiene/acrylonitrile copolymer (a). in for the polymers described herein.
can be determined by gel permeation chromatography using polybutadiene standards. The acrylonitrile content of the polymer varies from about 10 to about 50 weight percent, preferably from about 15 to about 40%. Optionally, the copolymer also has a carboxyl content of 0 to about 15%. If the copolymer contains carboxyl groups, the carboxyl content is preferably from about 1 to about 1
5% by weight, most preferably in the range of about 2 to about 10% by weight. The copolymer is about 55-9% by weight of the total composition.
It is present in an amount of 0% by weight, and preferably from about 60 to about 75%. At least about 55% by weight copolymer is required to provide sufficient flexibility and physical integrity to the photosensitive element, particularly for flexography plates.

Carboxyl groups can be incorporated into high molecular weight copolymers by adding carboxyl-containing monomers such as acrylic or methacrylic acid or monomers convertible to carboxyl-containing groups such as maleic anhydride or methyl methacrylate to the polymerization process. can. Such polymers come from several sources such as B, F, GOOdrloh
Chemlca, from one company [Hycar■]
It is commercially available under the trade name ``.

Another essential ingredient of the photosensitive compositions of the invention is a non-gaseous ethylenically unsaturated compound (b) containing at least one terminal ethylene group. The compound should be capable of forming a high molecular weight polymer by free radical initiated chain length addition polymerization and be compatible with the high molecular weight polymer (a). One group of suitable ethylenically unsaturated compounds include unsaturated esters of alcohols, especially such esters with α-methylenecarboxylic acid and tmα-methylenecarboxylic acid, and more particularly such esters of alkylene polyols and polyalkylene polyols. Esther.

and most particularly alkylene polyol di- and triacrylates and realkylene polyols made from sulalkylene polyols containing 2 to 15 carbon atoms or polyalkylene ether polyols or glycols containing 1 to 10 ether linkages. Ordi and triacrylates are drilled.

The following specific fossil foods are other examples of this group. Tertiary butyl acrylate and methacrylate), 1.
5-bentanediol diacrylate and dimethacrylate, N,N-diethylaminoethyl acrylate and methacrylate, ethylene glycol diacrylate and dimethacrylate)% 1,4-butanediol diacrylate and dimethacrylate, diethylene glycol diacrylate and dimethacrylate,
hexamethylene glycol diacrylate and dimethacrylate), 1,3-propanediol diacrylate and dimethacrylate, decamethylene glycol diacrylate and dimethacrylate), 1,4-cyclohexanediol diacrylate and dimethacrylate 1
/-t, 2,2-dimethylolpropane diacrylate and dimethacrylate, glycerol diacrylate and dimethacrylate, tripropylene glycol diacrylate and dimethacrylate, glycerol triacrylate and trimethacrylate, trimethylolpropane triacrylate and trimethacrylate 2,2-di(p -Hydroxydiphenyl) fluoropane diacrylate, 5 lythritol tetraacrylate and tetramethacrylate, 2,
2-di(p-hydroxyphenyl)furopane dimethacrylate, triethylene colcia, acrylate, polyoxyethyl-2,2-di(p-hydroxyphenyl)furopane dimethacrylate, bisphenol A di(3-methacrylate) oxy-2-hydroxypropyl) ether, di(2-methacryloxyethyl) ether of bisphenol A.

eMe, phenol A di(3-acryloxy-2-hydroxypropyl) ether, bisphenol A di(3-acryloxy-2-hydroxypropyl) ether,
2-acryloxyethyl)ether, di(5-methacryloxy-2-hydroxypropyl)ether of tetrachlorobisphenol A, tet, di(2-methacryloxyethyl)ether of lachlorobisphenol A, tetrabromo Di(3-methacryloxy-2-hydroxypropyl) ether of bisphenol A, di(2-methacryloxyethyl) ether of tetrabromobisphenol A, di(3-methacryloxyethyl) ether of 1,4-butanediol
methacryloxy-2-hydroxypropyl)ether,
j, 2,4-butanetriol triacrylate and trimethacrylate.

2.2.4-Trimethyl-1,6-intanesiol diacrylate and dimethacrylate % 1-7-earthylethylene-1,2-dimethacrylate, diallyl fumarate, styrene s 1,4-benzenediol dimethacrylate, 1. j-diimpropenylbenzene and 1)3#5-)! J isopropenylbenzene aromatic polyhuman mixtures such as bisphenols, novolacs and similar compounds, such as dijepoxy polyethers derived from those described in U.S. Pat. No. 3,661,576, which is hereby incorporated by reference. Also useful are acrylate and dimethacrylate esters, such as bisacrylates and methacrylates of polyethylene glycols with molecular weights from 200 to 500, and others.

Other groups of suitable ethylenically unsaturated compounds include U.S. Pat. No. 2,927, incorporated herein by reference;
The compounds disclosed in '022 are particularly those having a plurality of addition-polymerizable ethylene bonds when present as terminal bonds, and in particular those in which at least one and preferably most of such bonds are carbon-carbon- Carbon double bonds and carbon heteroatoms (e.g. nitrogen, oxygen and sulfur)
Examples include those conjugated with a double bond carbon containing a double bond with. Preferred are those in which an ethylenically unsaturated group, especially a vinylidene group, is conjugated with an ester or amide structure.

Specific examples of such compounds include unsaturated amides, especially α
- Examples of amides of methylenecarboxylic acids with α,ω-diamines and oxygen-interrupted ω-diamines, such as methylenebisacrylamide, methylenebismethacrylamide, ethylenebismethacrylamide, 1,6-hexamethylenebis-acrylamide, diethylenetriamine Tris methacrylamide, bis(methacrylamidopropoxy)ethane, β-methacrylamidoethyl methacrylate), N-
(β-hydroxyethyl)-β-(methacrylamide)
Ethyl acrylate, and N,N-bis(β-methacryloxyethyl)acrylamide, vinyl ester difluorophores divinyl succinate, divinyl adipate, divinyl phthalate, cyhinyl terephthalate, divinyl benyl 1,3-disulfonate, and divinyl Examples include butane-1,4-disulfonate, diallyl fumarate, and others.

Other ethylenically unsaturated compounds that can be used include 1
, styrene and its derivatives% 114-diisopro is an adduct of nylbenzene, 1,3.5-triisopropenylbenzene, itaconic anhydride with hydroxyethyl acrylate, (1+1), itaconic anhydride and terminal Adducts of liquid butadiene/acrylonitrile polymers containing amino groups and diacrylate and dimethacrylate esters of itaconic anhydride and jepoxy polyethers, US Pat. No. 5,661,
576, polybutadiene and butadiene/acrylonitrile copolymers containing terminal and pendant vinyl groups, and unsaturated aldehydes such as sorbaldehyde (2,4-hexagenal).

When aqueous basic developable systems are involved, water-bathable or ethylenically unsaturated compounds containing carboxyl or other alkali-reactive groups are particularly suitable. Further, U.S. Pat. No. 3,043,805 and U.S. Pat. No. 2,929
, 710, and similar materials may be used alone or in admixture with other materials.

Also useful are acrylic and methacrylic esters of ethylene oxide and adducts of polyhydric hydroxy compounds, such as those described in US Pat. No. 3,380,831. U.S. Pat. No. 3,418,295 and U.S. Pat.
The optically cross-linking polymers disclosed in No. 448,089 may also be used. All of these US patents are incorporated herein by reference.

The amount of unsaturated compound added should range from about 2 to about 40 percent by weight, based on the total weight of the composition. The specific amount for optimal results will vary depending on the particular polymer used. Preferably the amount of unsaturated compounds is from about 5 to about 25 parts by weight.
It is within the range of

The ethylenically unsaturated compound is preferably about 1
It has a boiling point of 00°C or higher. The most preferred ethylenically unsaturated compounds are triethylene glycol diacrylate, triethylene glycol dimethacrylate, hexamethylene glycol dimethacrylate and hexamethylene glycol diacrylate.

The photosensitive compositions of the present invention do not substantially scatter actinic radiation when in the form of a thin layer as described above. - The butadiene copolymer and polymer components are compatible with the ethylenically unsaturated compound in the proportions used to ensure a substantially transparent mixture, i.e. a non-radiative scattering mixture.
and preferably should be soluble therein.

"Compatibility" refers to the ability of two or more components to remain dispersed without causing significant amounts of actinic radiation scattering from each other.

Compatibility is often limited by the relative proportions of the components, and incompatibility is evidenced by the formation of a haze in the photosensitive composition. Some slight spiders may occur in the production of printed reliefs.

Such compositions may be obtained before or during exposure. However, in situations where fine details are desired
spiders should be completely excluded. The amount of ethylenically unsaturated compound, or any other components used, is therefore limited to concentrations that do not produce undesirable light scattering or clouding.

Other essential ingredients of the photosensitive compositions of the present invention are organic radiation-sensitive free radical-generating initiators or initiator threads (Q
). Virtually any organic radiation-sensitive free radical-generating initiator system that initiates and does not unduly terminate the polymerization of unsaturated compounds can be used in the photosensitive compositions of the present invention. The term "organic" is used herein to refer to compounds containing carbon and 91 or more oxygen, hydrogen, nitrogen, sulfur and halogens, but no metals. Because the process images used for imagewise exposure transfer heat generated from conventional sources of actinic radiation and the photosensitive compositions are typically manufactured under conditions that produce high temperature results,
Preferred free radical-generating initiator compounds are thermally inert below 85°C, and more preferably below 185°C. They should be dispersible in the composition to the extent necessary to initiate the desired polymerization or cross-linking under the influence of the amount of radiation absorbed in a relatively short exposure.

These initiators are based on the total weight of the solvent-free photosensitive composition, and preferably range from about 1,001 to about 10% by weight, and preferably from about 0.
．． Amounts of 1 to about 5 parts by weight are useful.

This free radical-generating initiator system has about 200p to about 80p
．． absorbs radiation in the range of 0OA and about 2500 to about 8000A and preferably about 2500 to about 500OA
at least one component having an actinic radiation absorption band having a molecular extinction coefficient of at least about 50 within the range of . By "actinic radiation absorption band" is meant a band of radiation active to generate the free radicals necessary to initiate polymerization or cross-linking of unsaturated materials.

Free radical-generating initiator systems can include 1 ya or more compounds that directly provide free radicals when activated by radiation. It may also include multiple compounds, one of which generates free radicals after doing so with a radiation-activated sensitizer.

A large number of such free radical-generating compounds can be used in the practice of the present invention, including aromatic ketones such as benzophenone, Michler's ketone 5 (4t4'-bis(dimethylamino)benzopheno 2
3% 414'-bis(diethylamino)bensifune, 4-acryloxy-4'-dimethylaminobenzophenone, 4-acryloxy-4'-jethylaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-phenyl-2,2-dimethoxyacetophenone (2,2-dimethoxy-1,2-diphenylethanone), 2-ethylanthraquinone, phenanthraquinone, 2-tertiary butylanthraquinone, 1.2-
-'nzanthraquinone, 2,6-benzanthraquinone, 216-cyclonaphthoquinone, benzyl dimethyl acetal and other aromatic ketones, benzoin,
benzoin ethers such as benzoin methyl ether,
Benzoin ethyl ether, benzoin isobutyl ether and benzoin phenyl ether, methylbenzoin, ethylbenzoin and other benzoins and 2.4.5-arylimidazolyl 12 compounds, such as 2-(0-chlorophenyl)-4,5-diphenylimidazolyl dimer, 2-(o-chlorophenyl-
4,5-i; (m-me)xyphenyl)imizoy)
luni, 2-(o-fluorophenyl)-4,5
-diphenylimidazolyl dimer, 2-(0-methoxyphenyl) -4,5-diphenylimidazolyl dimer s 2-(p-methoxyphenyl) -4,5-diphenylimidazolyl dimer, 2.4- cy(p-methoxyphenyl)-5-phenylimidazolyl dimer, 2
- (2,4'-dimethoxyphenyl) -4,5-diphenylimidazolyl dimer, 2- (p-methylmercaptophenyl) -4,5-diphenylimidazolyl dimer, and other U.S. Pat. 479,185 and 3,784,557 and British Patent No. 997.
No. 396 and No. 1,047,569 are disclosed. These patents are incorporated herein by reference.

The imidazolyl dimer is a free radical-generating electron donor (
donor) e.g. 2-mercaptobenzisoxazole,
Can be used with leuco crystal violet or tri(4-diethylamino-2-methylphenyl)methane. Sensitizers such as Michler's ketones can be added. Various energy transfer dyes such as rose bengal and eosin Y may also be used. Other examples of suitable disclosing agents are disclosed in US Pat. No. 2,760,865, which is incorporated herein by reference.

The photosensitive composition may also contain a small amount of a thermal addition polymerization inhibitor, for example from 0.001 to 2.0 by weight, based on the total weight of the solvent-free photosensitive composition. Suitable inhibitors include hydroquinone and alkyl- and aryl-substituted hydroquinones, 2.6-di-tert-butyl-4
- methylphenol, p-methoxyphenol, tertiary-butylpyrocatechol, hyrogallol, β-naphthol, 2.6-di6-butyl-p-cresol, phenothiazine, pyridine, nitrobenzene, dinitrobenzene, and Mention may be made of the nitrogenous dimer inhibitor systems described in incorporated US Pat. No. 4,168.9s2. Other useful inhibitors include p-toluquinone, chloranil and thiazine dyes such as Thionin Blue G (C 52025), Methylene Blue B (C 52015) and Toluidine Blue (C 52040). Such photosensitive paraboloids can be photopolymerized or photocrosslinked without removing the inhibitor. Preferred inhibitors are 2,6
1-di-tertiary-butyl-4-methylphenol p-
It is methoxyphenol.

The oxygen and ozone resistance of the photosensitive compositions of the invention and of the printed reliefs left therefrom can be improved by incorporating suitable amounts of compatible, well-known antioxidants and/or antiozonants. Antioxidants useful in the present invention include alkylated phenols such as 2,6-di-5-butyl-4-methylphenol, alkylated hisphenols, 2-methylenebis-(4-methyl-6-6- Butyluphenol), 1.3.5-)
Listyl-2,4,6-)Lis(3,5-di6th-butyl'-4-hydroxybenzyl)Hanzen, 2-(4-
Hydroxy-3,5-ditertiary butylanilino) -4
,6-bis(n-octylthio)-1,3,5-)
Examples include IJ thiazine polymerized trimethyldihydroquinone and dilaurylthiopropionate.

Antiozonants useful in the present invention include fine waxes and paraffin waxes, dibutylthiourea, 1.1
．． 3,3-tetramethyl-2-thiourea, antiozonant AFD (product of Nafton), norbornene e.g.
- norbornene-2-methyl terephthalate, Ozone Protector 80 (product of Reichhold Chemical Co.),
N-phenyl-2-naphthylamine, unsaturated vegetable oils such as rapeseed oil, linseed oil, safflower oil, polymers and resins such as ethylene/vinyl acetate copolymer resins, chlorinated polyethylene, chlorosulfonated polyethylene, chlorinated ethylene/methacrylic acid copolymer, polyurethane,
Polypentadiene, polybutadiene, furfural 94
Polymer resins, ethylene/propylene/diene rubbers, diethylene glycol esters and α-methylstyrene/hinyltoluene copolymers are used. The ozone resistance of the printed relief produced can also be improved by anealing it at elevated temperatures before use.

Optionally, immiscible polymeric or non-polymeric organic or inorganic fillers or reinforcing agents that are substantially transparent at the wavelengths used for exposing the photosensitizer and do not scatter actinic radiation, e.g. The photosensitive compositions may contain polystyrene, organophilic silica, bentonite, silica, powdered glass, colloidal carbon, and various types of dyes and pigments. Such materials are used in varying amounts depending on the desired properties of the elastomer. Fillers are useful in improving the strength of the elastomer layer, reducing tack, and even as colorants.

The photosensitive composition preferably contains a compatible plasticizer to lower the glass transition temperature of the binder and to facilitate selective development.

The plasticizer can be any common plasticizer that is compatible with the polymeric binder. Among the common plasticizers are dialkyl phthalates, alkyl phosphates, polyethylene glycols, polyethylene glycol esters and hypopolyethylene glycol ethers. Other useful plasticizers include oleic acid, lauric acid, and others.

Polyesters such as polyethylene sebacate and others are preferred plasticizers. Plasticizers are generally present in an amount of 1 to 15% by weight, based on the total solids weight of the photosensitive composition.

The photosensitive composition of the present invention can be prepared by combining each of the ingredients (a) high molecular weight butadiene/acryloni) in any suitable manner.
(b) a compatible ethylenically unsaturated compound and (C) a free radical-forming initiator system.

For example, flowable compositions may contain these and other desired additives in any order and optionally solvents such as chlorinated hydrocarbons such as methylene chloride, chloroform, methylchloroform, chlorobentane, trichloroethylene, tetrachloroethylene and chlorotoluene, on the ketone side. The light is methyl ethyl ketone, diethyl ketone and methyl isobutyl ketone, aromatic hydrocarbons such as benzene,
It can be prepared by mixing with the aid of toluene and xylene and tetrahydrofuran. The solvent may contain as diluent acetone, low molecular weight alcohols such as methyl, ethyl and propyl alcohol and esters such as methyl acetate, ethyl acetate and propyl acetate. This solvent can later be removed by heating the mixture or extrusion layer.

Conventional milling, mixing and solution techniques can be used in the manufacture of these compositions. The specific technique will vary depending on the different properties of each component. The homogeneous substantially non-radiative scattering composition is formed into layers or sheets in any desired manner. For example, solvent casting,
Hot pressing, calendering or extrusion are suitable methods for producing layers of desired thickness.

The photosensitive elements of the present invention can be in the form of a photosensitive layer or self-supporting sheet on a suitable forming wheel, bolt or platen by solvent casting or extrusion, calendering or hot pressing of the photosensitive composition. This layer or sheet can then be laminated onto the flexible support surface and adhered with the adhesive blend described below. If a solution is used, the coating can be formed on the adhesive-containing support.

The thickness of the photosensitive layer formed is a direct function of the thickness desired in the relief image, and this depends on the subject matter to be reproduced and the final use of the relief. For example, thick soft η relief is useful for flexographic printing, and thin hard relief is useful for lithographic printing. - The thickness of the photosensitive layer is approximately 0.250 mm
less than an inch. For example, it may range from about 0.005 to about 0.
250 inches (0.13 to 0.6350) and layers in this thickness range are used in the majority of printing plates.

Between said photosensitive layer and one flexible support there is preferably a layer of adhesive blend, which is described in 4a! It includes at least two kinds of polymers selected from the group of polymers.

(1) Polyester resin. A condensation polymer of ethylene glycol, terephthalic acid, isophthalic acid and azelaic acid in a molar ratio of approximately 6+2:1:5 with a Mw of 19,000 & and 37,000.

(2) Polyester polyurethane resin. 15% by weight
100-1 in solids methyl ethyl ketone and using a Brookfield spindle +5 at 12 rpm.
Brookfield viscosity of 200 centipoise and 5
Crystalline thermoplastic resin-c6 with adhesive activation temperature ranging from 4 to 53°C. This polyester polyurethane resin has an elongation at yield of 15%, an elongation at break of 615%, and an elongation at break of 600%.
It has a 400% elongation modulus of psi (42,18 in/c++2) and a crystallinity loss temperature of 49°C.

<3), yv amide resin. Translucent bright yellow/brown color.

Ball-and-ring softening point of 162-145°C, melt viscosity of 40-60 poise at 210°C, 299
Ignition point above ℃, 0.7 in 1 day and 1.6 in 7 days
% water absorption, 460psi (32,34Kf/1yn
2) Tensile strength at yield point, 450 psl (3 colors 4Kg
/cm2) and an elongation of 560% (tensile strength at yield, tensile strength at break 9 strength and elongation measured at 24°C according to ASTM method D-1708).

(4) Polyamide resin. A bright, semi-transparent color.

Ring and ball softening point at 150-160℃, 28-68 at 210℃
Poise viscosity, 1.5 inches in 1 day and 2.8% water absorption in 7 days, and -18°C - 24°C - 60°C (Tensile yield, tensile breakage and elongation are determined according to ASTM method D-1708 at the stated temperatures. The number average molecular weight (n) of the resin can be determined by gel permeation chromatography (GPC) using known standards such as polybutadiene, which is known to those skilled in the art. The weight average molecular weight (IW) of the resin is determined in a manner known to the painter by the use of light scattering techniques using known standards such as polystyrene, polymethacrylate, polymethyl methacrylate, and others! 7 can be measured.

This particular combination is within the following ranges based on the total weight of resin in the adhesive composition: (1) 0-78% by weight; (2) 0-78% by weight; (3) 0-94% by weight; 4) Can be present in the adhesive blend in the range of 0-97ffii%.

Preferred adhesive blends containing 4P, 5M and 2 resin components are described below, where percentages are based on the weight of all resin components.

A range of four-component adhesive blends are as follows.

(1) 25-31% by weight, preferably 25%.

(2) '2.5 to 31% by weight, preferably 25%,
(8) 25-19% by weight, preferably 25%, and (4) 25-1°9% by weight, preferably 25%.

A range of two five-component adhesive blends A and B are as follows.

A (1) 1-78-78%1. Preferably 1-6
5%.

(2) 1 to 78% by weight, preferably 1 to 65%.

(8) 1-94mkit:%, preferably 1-90
%. .

B (1) 1-63 weight strength, preferably 1-45
%.

(8) 1 to 93% by weight, preferably 1 to 85%.

error (4) 1-9731i-axe, preferably 1-90%.

The range of the 5al two-component adhesive blend C-G is as follows: C. adhesive blends are particularly preferred.

C<1) 7-77%, preferably 15-30% most preferably 30% and (3195-25%, preferably 85-5011 also preferably 70%).

D(1,) 5-60%, more preferably 5-3o and (4) 97-40o, more preferably 95-7o.

B (1) 23~77 hits, preferably 35~
45% and (2) 77-23%, preferably 65
~55%0F (2) 10~60%, preferably 25~
50% and (4) 90-40 conversion, preferably 75-70
%.

G (2) 7-72%, preferably 15-50% and (8) 93-28%, preferably 85-5o%.

Adhesive blends of the present invention have at least 3 bonds/inch (
55,57 Kf/m 2 ) and generally provide greater adhesive support/photosensitive layer adhesion values in the range of, for example, 8 bonds/inch (142,86 Kg/m 2 ) or more. These adhesion values are sufficient when the element according to the invention is used as a printing plate, especially as a frettage printing plate.

The adhesive blend preferably contains additives such as blocking inhibitors, colorants such as dyes, and the like. Useful blocking inhibitors preferably include polyolefin particles or beads or other hard particles or beads such as silicon dioxide and the like. The surfactant dioctyl natri-9 musulfosuccinate may be used. Preferred polyolefin materials are described in the Examples.

The bead size of the blocking inhibitor can be larger than the thickness of the adhesive layer. As a result, the beads partially protrude outside the layer of adhesive blend. It is believed that such a structure has little or no effect on the degree of adhesion. Many types of colorants or dyes are also useful in the adhesive layer.

A preferred dye is DuPont Milling Blue BL (CI Acid Blue 59). Other useful dyes include methylene violet (CI Basic Violets)
), ``Raxol'' Fast Blue MBEIN (CI Solvent Blue 58), ``Pontasil'' Wool Blue B
L ((J acid blue 59 or C engineering 50315),
"Bontasil" Wool Blue GL (CI Acid Blue 102 or C-work 50320), Victoria Pure Blue BO (CI Basic Proof or C-work 4259)
5), C engineering 109 red die, Rhodamine 3GO (CI
Basic Red 4), Rhodamine 6GDN (CI Basic Red 1 or C-45160), Tsukushin Dye (C-42510), Chalcozide Green S (
C engineering 44090) and anthraquinone blue 2GA (
CI Acid Blue 58) is mentioned.

The adhesive solution is generally prepared by adding the components (i.e., polymer, polyolefin block inhibitor, colorant) to the solvent in the following order with continuous stirring. Useful solvents include mixtures such as methylene chloride/ethyl acetate, methylene chloride/n-butyl acetate, methylene chloride/n-butyl acetate, methylene chloride/methanol/cellosolve, etc., and preferably methylene chloride/cellosolve (9(1/ 10 copies)
The mixture is opened. Additional solvent can be added to compensate for any weight loss. Solvent selection is governed by the desire to provide the fastest practical drying rate without blistering the coating and without leaving small amounts of solvent behind. The solvent should also have a solubilizing effect on the dye present.

The adhesive solution is then applied to the flexible support by known means, e.g. using a doctor blade or coated in a commercially available continuous web coater dryer, to a concentration of about 80-500 mg/dm2, preferably produces a dry coating weight in the range of about 260-300 Mg/dm2. The most preferred coating weight of the adhesive layer is about 260 Q/d m2. Generally, the adhesive is 0.0008 to 0.001 inch (0.020 inch)
~0.025 mm) dry thickness. In continuous coating, the web speed may vary, for example, from 15 to 150 feet/minute (4.57 to 45.72 m/min). Drying temperature is 60-130℃, preferably 80-9
It is in the range of 0°C.

Preferred flexible supports have a thickness of 0.001 to 0.00 inches (0.025 to 0.18 sm), preferably 0.0
Flame treatment of monopolymer films of 0.5 inch (0.13111) thick flame treated polyethylene terephthalate is known. U.S. Rev. Nos. 3,145,242, 3,360,029, and 3,391,912, incorporated herein by reference, are useful for flame treatment of polymeric films. A method and apparatus are described. The fuel equivalence ratio φ of the combustion gas mixture is 1.4, which is equal to 5(propane flow rate)/[(oxygen flow rate) ten (0,21 air flow rate)]. All flow rates are standard cubic feet or 47 minutes. The web speed is 175 linear ft/min (55.34 m/min).

The dried adhesive coated support can be adhered immediately to the photosensitive layer or can be saved for subsequent adhesion. To form the photosensitive element, the adhesive-coated support is applied to the photosensitive layer in a press at e.g.
0,000~30,000ps1 (1406~210
Lamination can be carried out by applying a pressure of 9 Kf/piece 2) for up to about 6 minutes and then cooling to below 60° C. in a press. Preferably the photosensitive element is produced by calendering. The photosensitive layer of the embossment, preferably extruded through a die, extends 0.005 inches (0.13 mm) from the side adjacent the adhesive layer.
m+) thick polyethylene terephthalate film is present, which subsequently acts as a protective cover sheet. Other films such as polystyrene, polyethylene, polypropylene or other release materials may be used. Preferably, between the photosensitive layer and the film cover sheet there is present a thin, rigid, flexible, solvent-soluble layer, such as a flexible polymeric film or layer, such as polyamide or a copolymer of ethylene and vinyl acetate. The flexible polymer film is removed from the film cover sheet.
After removal, it remains on the photosensitive layer. The angle-flexible polymeric film protects the overlying image-containing negative or bright image for reuse or improves contact or registration with the light-sensitive surface. The photosensitive element is then fogged through the support to polymerize a predetermined thickness of the photosensitive layer adjacent the adhesive support, prior to imagewise illumination using the light source described below. This polymerized portion of the photosensitive layer is referred to as a 7o atom. Floor thickness depends on exposure time, exposure source, etc.
It fluctuates. This exposure is generally for 1 to 60 minutes.

In accordance with the present invention, selected portions of the photosensitive layer of the element may be made, for example, in a process transparency, i.e., virtually transparent to actinic radiation, to provide a substantially uniform optical density area and a portion that is insensitive to actinic radiation. A printed relief can then be produced by exposing the entire image-containing transparency or stencil having areas of substantially uniform optical density to light until substantial addition polymerization or optical cross-linking occurs. During addition polymerization or cross-link formation, the butadiene/acrylonitrile copolymer/ethylenically unsaturated compound composition is converted to an insoluble state in the radiation island light portion of the layer and no significant polymerization or polymerization occurs in the unexposed portions or areas of the layer. No cross-linking occurs. The unfogged light portions of the layer are removed with a TL liquid developer containing a combination of molecular weight butadiene/acrylonitrile.

Actinic radiation from any light source of any type may be used in the photopolymerization process. The radiation may originate from a point source or may be in the form of a parallel ray cabinet or a diverging beam. By using a broad radiation source relatively close to the image-containing transparency, the radiation passing through the transparent portion of the image-containing transparency enters as a diverging ray and continuously traverses the diverging portion in the light-sensitive layer below the transparent portion of the transparency. irradiate.

This results in a ie trapezoidal polymer relief with its greatest width at the bottom of the photosensitive layer. The upper surface of this relief is a symmension of the transparent part.

Insofar as the free radical-generating initiator system activatable by actinic radiation exhibits its maximum sensitivity in the ultraviolet range, the radiation source preferably provides an effective amount of radiation having a wavelength range of 2500A to 5000λ. Should. Suitable such sources include solar radiation as well as carbon arcs,
Mention may be made of mercury vapor arcs, fluorescent lamps with ultraviolet emitting luminescent phosphors, argon glow lamps, electronic flash units, and photographic flood lamps. Electron accelerators and electron beam sources via suitable masks may also be used. Among these, mercury vapor lamps, especially the sunlamp or "blacklight" type and fluorescent sunlamps are the most suitable.

The radiation exposure time can vary from a fraction of a second to several minutes depending on the intensity and spectral energy distribution of the radiation, its distance from the composition and the nature and scenery of the composition available. a mercury vapor arc, typically at a distance of about 1.5 to about 60 inches (3,8α - 152 ffl) from the photosensitive composition;
Sunlights or high UV output fluorescent tubes are used.

The exposure temperature is not particularly critical, but it is preferred to operate at about room temperature to slightly elevated temperatures, ie, from about 20° to about 35°C.

After imagewise exposure, the image can be developed by washing with a suitable developer. The developer has a good solvent or swelling effect on the butadiene/acrylonitrile copolymer/ethylenically unsaturated compound composition and during the period required for the removal of unpolymerized or uncrosslinked moieties. , the insolubilized image or support or adhesive layer should be free of any residual effects.

The developer preferably also removes the polymer film layer, if present. Suitable developers include organic solvents such as 2-butanone, benzene, toluene, xylene, trichloroethane, trichloroethylene, methylchloroform, tetrachloroethylene and solvent mixtures such as tetrachloroethylene/n-butanol and others.

When the high molecular weight butadiene/acrylonitrile copolymer component contains carboxyl groups, suitable solvents include aqueous bases, which may be supplemented with water-soluble organic solvents.

Suitable specific developer mixtures include sodium hydroxide/
Isopropyl alcohol/water, sodium carbonate/water, sodium carbonate/2-butoxyshetanol/water, sodium borate/2-butoxyshetanol/water, sodium silicate/2-butoxycetanol/glycerol/water, sodium carbonate/2- (2-Butoxyethoxy)ethanol/water, and sodium hydroxide (0,5
4ti%). This is f/lL. The chosen developer combination depends on the carboxyl content of the photosensitive composition and the properties and amounts of the sizing agents used. Other aqueous developer combinations that may be used are described in US Revision No. 5,796,602, which is incorporated herein by reference. These aqueous base/water-soluble organic solvent combinations may be preferred in some cases because of their low cost, nonflammability, and low toxicity.

Development may be carried out at about 25°C, but sometimes the best results are obtained when the temperature of the solvent is between 30° and 60°C.

Development times can range from 1 to 120 minutes, preferably from 1 to 25 minutes.

In the development step where the relief is formed, the developer can be applied in any convenient manner, such as by dipping, dipping, spraying or roller application. Brushing helps remove unpolymerized or uncrosslinked portions of the composition. For aqueous development of printing plates, for example, about 5
Aqueous for ~300 seconds is then applied to the developer plate to remove traces of developer from the plate surface.

The expression "aqueous development" includes washing with water.

After solvent development, the printing plate is dried for 1 hour at a temperature ranging from room temperature to about 125°C, preferably 60°C. The printing plate may be dried after aqueous development, but the washed aqueous developer plate can be contacted with an aqueous bromine- or iodine-containing solution while still wet. Optional hot air drying can be accomplished through the use of a forced hot air dryer or other suitable dryer.

The plates were first soaked in an aqueous solution with a free bromine concentration of 0.01-3.5% by weight and a pH of 0.7-8.7.
5 seconds to 20 minutes, or 6.2 to 10! #The shell is placed in contact with an aqueous solution having a free iodine concentration for about 1.0 to 10 minutes. For example, 0.01 to 1.0 molar concentrations of Na0ct and 0012
~1.2 by an aqueous solution of HCl with a molar concentration of ~15 by a solution with a free chlorine concentration equal to that supplied by 9
Perform chlorine treatment for seconds to 5 minutes.

The plate can be flooded with an aqueous bromine solution or immersed in a bromine solution, the latter being preferred. bromine solution for 15 seconds to 20 minutes, more preferably 30 minutes.
It is preferable to keep it in contact with the printing plate for seconds to 5 minutes.

The bromine solution is preferably used at ambient temperature, but it can be heated to about 65°C.

This bromine-containing solution contains (1) bromine, (2) a bromate-bromide-acid system (bromate and bromide are salts of alkali metals, preferably sodium or potassium, and acids are hydrochloric acid, hydrobromic acid, sulfamic acid or other strong protic acids) (8) for example German Patent No. 2,8
23,300, a bromine-containing complex;
or (4) a monopersulfate-bromide system in which the monopersulfate and bromide are salts of an alkali metal, preferably the sodium or potassium salts mentioned above, and U.S. Patent Application No. 375,975, incorporated herein by reference. (as disclosed in the specification) to water. Preferably, the bromine-containing solution is prepared by adding 20 ml of concentrated HCl to 1,800 liters of tap water while mixing.
l can be manufactured. Add to this solution, while mixing, a mixture of 200 °C of tap water, 102 °C of potassium bromide, and 2.8 °F of potassium bromate (90.56% H20/8.8 °F).
1% HCL/0.49 To KBr and 0.49 To KBr.
14% KBrO3). Free bromine concentration is 0.4%.

Instead of an aqueous chlorine solution, the printing plate can be flooded with or immersed in an aqueous iodine solution. The latter is preferred. Preferably the iodine solution is held in contact with the printing plate for 1.5 to 2.5 minutes.

The iodine solution is preferably used at ambient temperature, but it can be heated to about 35°C. Preferably, the iodine-containing solution can be prepared by adding, for example, 6.4 tons of potassium iodide and, for example, 12.7 tons of iodine to 200 tons of water.

After carrying out one of the aforementioned halogen treatments, the printing plate can be flooded or immersed in an aqueous chlorine solution. Preferably, the chlorine solution is held in contact with the printing plate for 0.5 to 1.0 minutes. The chlorine solution is preferably used at ambient temperature, but it can be heated to about 65°C. - The chlorine-containing solution is 90- [C1orox■] and concentrated i.e. 39% hydrochloric acid IC1fn1. By adding p to 900ml of water
Can be manufactured.

After imagewise exposure and development, the printing plate can be post-exposed to a source of actinic radiation either before or after said halogen treatment. Post-exposure generally preferably lasts from 5 to 15 minutes to the actinic radiation source used for imagewise exposure.

After image processing, the printing plate is ready for use.

A preferred embodiment is illustrated in Example 1.

Printed reliefs produced from the light-sensitive flexographic elements of the invention can be used for all types of printing, but only for those types where a distinct height difference between the printed and non-printed parts is required. Printing, and especially I
It is most applicable to frettage printing where +i-characterized printed parts are required for example for printing on deformable printing surfaces. These types include, for example, dry offset printing, where the ink is carried by raised areas of the relief, as in conventional letterpress printing, which requires a large height difference between the printed and non-printed areas. and those in which the ink is carried and dispersed by recesses in the relief, as in intaglio printing, for example in line and inverted halftones. This plate is particularly useful for multicolor printing.

The resulting relief and printed images exhibit fidelity to the original transparency in both fine detail and overall dimension even when the element is imagewise exposed on a cylindrical support. The relief has high impact strength, is tough and abrasion resistant, has broad ink compatibility and has improved solvent resistance.

The following examples illustrate the invention, in which parts and parts are by weight. The following tests are useful in evaluating printing plates.

Tackiness Test The exposure and development printing plate of the present invention can be tested for its tackiness as follows.

(1) Wipe the surface clean with an impropa tool.

(2) Tissue For example, Scotto brand 510 toilet tissue is placed on the plate surface (1 inch x 2 inches, 2.54 x 5.083) using a 5002 weight.
Press for 0 seconds.

(8) Remove the tissue and record the results according to the following criteria.

(4) No tack - no tack B) Slight tack - sticks but peels off from the surface (C) Adhesive - peels off but leaves a few fibers on the plate φ) Very tacky - Those skilled in the art can fix non-tacky or grade (A) printing plate surfaces by the tactile method, which will stick and tear when the tissue is peeled off.

Both methods have been used.

All processed samples below are untacked.

Ink/Solvent Compatibility Testing The following method is used to determine the compatibility and usefulness of printing inks and solvents with respect to frettage printing plates having photosensitive elastic composition layers as described herein.

The flat exposed and developed printing plate was tested for its thickness and Shore OA hardness (ANsI/AEITM D 2240-7).
5) After measuring the weight, it is immersed in a specific solvent or ink for 24 hours. After removal from the solvent or ink and batting dry with a ball of string, its thickness, Shaw A hardness and weight are measured. When raw data representing thickness change (△T) expressed in inches (inches), Shore A hardness change (△H), and weight change (△%W) satisfies all of the following Yanagi criteria: In this case, the printing plate is considered to be compatible or superior (In) with respect to solvent processing/or ink.

△Traw' 0.003 inches (0,076r
ras) △Hrag' ≧-5 Shore■ A unit Δ%
Wrap' ≦ 6,5% A printing plate is considered incompatible or unsatisfactory ([J) with respect to solvents and/or inks if any of the following standards are met or exceeded: Conceivable.

△T reLW ' 20.012 inches (0,30
5m) △HraW' ≦-20 Shore OA unit Δ%
w raw ' 510% In the middle range between the two standards, treated printing plates are of intermediate (1) utility with respect to solvents and/or inks.

In addition to the above evaluations that are useful for single halogen treatments,
These six physical measurements combine to form a single merit number (slngle), hereinafter referred to as "F".
It is also desirable to set it as ll'1 gure of Mer4t). The F values for the separate individual treatments can then be added together to give a heuristic prediction of the expected F for the combination of treatments.

F is obtained using the following equation.

23.60 Numerical coefficients for the various raw data were derived from the performance of the Plate without halogen treatment and tested in Improper Tool/Ethyl Acetate (80/20 volume ratio) as described below. Standardization factors and weighting factors have been estimated by those skilled in the art to indicate the relative importance of the data in predicting print performance.

The weighting factor (wf) is as follows.

For ΔT 0.35 ΔHO,25 Δ%W #0.40 The normalization factor (nf) is obtained from the control plate data as follows.

Therefore, the numerical coefficient or product (wf)IX(nf)
j becomes as follows.

For ΔT raW 0.152 ΔHraw′ −0,231 Δ%Wraw10400 In order to standardize all data to the same scale, ie 0-1, the coefficient for raw must be negative. The reason is that tsEr&y is negative.

Δ%Wr for a constant in the expression of F! Lm 23
, 60 reflects the conclusion that the 61w measurement is the most critical of these three.

1 for flexography photopolymerizable printing plates;
An F value of 0 represents a substantially perfect upper value for a superior plate. That is, solvent impregnation (soaking) produces no change in any of the six measured properties. Using the above formula for determining F, the above qualitative standard becomes:

Excellent (g) ≧=0.88~1.0
>='0.62~0.88 Unsatisfied (o)>=0.0
~0.62 That is, F is negative if (1) the printing plate is more susceptible to attack by the chosen solvent or (2) a stronger solvent is used in the compatibility test. The value of 0.0 can be taken. Furthermore, (8) certain individual treatments or non-inventive combinations of treatments actually reduce the solvent tolerance of treated plates to a greater extent than that of untreated plates. For example, compare treatments 1 and j for solvents 2, 3 and 4 in Table 2 below with treatment g. In Table 8, samples 2 and 3.8 and 9 and 14 and 1
Please compare the F value for 5.

For cases (1) and (2) above, F comb
Predict 1nat1on=F1+F2. Again, the above (8) is Fcomb1nat1on=F1+(F2
Expect I'untreated:).

These formulas are used below. Expected values are independent of processing order.

In addition to simplifying the intercomparison of the results of various processing combinations on frettage printing plates calculated for various ink/solvent combinations, the F-value is a Useful for predicting the number of good prints to be obtained in the prints used.

The following correlation exists when both print collection data and F-number are available.

0.94 2,000,000 sheets 0.88
200,000 sheets 0.69 < 5,000 sheets The adhesive solution is made from the following ingredients.

Polyester resin (1) 227.0 Poliozzi:
/39.8 The above polyamide resin (8) is [Macromelt (Mac
romelt ■) J 6238 [Product of Henkel Adhesip] It is a bright dark red color with a semi-light color, and has a ring and ball softening point of 152-145°C and a temperature of 40-40°C at 210°C.
Melt viscosity of 60 poise, ignition point above 299°C, moisture absorption of 0.7% in 1 day and 1.6- in 7 days, 460 p
tensile yield strength of si (52,64Kg7cm2),
It has a tensile strength at break of 450 pθi (31,64 Kf/ff12) and an elongation of 560% (tensile yield strength, tensile strength at break and elongation are ASTM Method D-1).
708 at 24°C).

Polyester resin is the reaction product of ethylene glycol, terephthalic acid, isophthalic acid and azelaic acid (611!30 molar ratio).

19,000 Mn work 37. It has an i7w of O[10.

Polyolefin has a "k st fine (Vθ5 to fi
Hs ■) J 8F-616 (a product of Doura Commodities), the color is snow white, and the weight is about 1.600
Molecular weight of % Density about 0.96 at 20°C, 0.5 at 25°C
Penetration hardness of ~1.0, melting point of about 118-128°C, about 8
The ingredients are sequentially mixed with methylene chloride/cellosolve (90%
/10) Add to the mixture to produce a solution of about 16% solids. Polyolefin beads do not dissolve. The mixture is continuously stirred during and after addition of the ingredients to effect dissolution.

Any loss of weight during mixing is compensated by addition of methylene chloride.

Apply this adhesive solution to a 0.005 inch (~0.13 inch) thickness using a continuous web coater/dryer.
It is applied to a flame treated surface of an engineered tylene terephthalate film support to produce a dry coating weight of about 260 m9/dm2. Web speed is 45 feet/min (~1
5.72 m/min) and the drying temperature was 86°C (18
6,7″F).

Place the adhesive-coated polyethylene phthalate support, adhesive side up, at 0.00 mm of the thickness of the finished printing plate.
Place in a 0.80 inch (2.03 m) thick damped steel platen. The adhesive coated support and platen are placed on the press and have a layer of polyamide resin having a dry thickness of 0.0001 inch (0.004 m). , a 0.090 inch (approximately 2.29'w) thick extruded sheet of the photopolymerizable composition on a polyethylene terephthalate cover sheet having a thickness of 0.000 mm (0713 m + 11 mm) was placed thereon with the cover sheet side up. , and cover with a steel plate.

A cover 7 with a polyamide layer is manufactured by coating a polyethylene terephthalate film with the following solution using an extrusion coater:

Methylene chloride 81.0 Methanol
2. ON-methylpyrrolidone
10.0 polyamide resin
7.0 The polyamide resin used here is Macromelt (Macromel 6900 (product of Henkel Adhesive), 266-302'FC7) ring and ball softening point, 5-647/159710''F melting index,
570) ignition point, 0.2% in 1 day and 0.5 in 7 days
% water absorption, tensile υ yield strength of 1200 ps1, 35
It has a tensile strength at break of 00 ps1 and an elongation of 540 inches (Tensile yield strength, tensile strength at break and elongation are measured by the method of A8TM D-1708 at 24°C).
.

Extruded sheets of the photopolymerizable composition are prepared by blending the following ingredients and extruding through a die at 170°C.

Hexamethylene diacrylate) 10
．． 0enone 2.6-di-tert-butyl-4-methylpheno 0.
The temperature is increased and pressure is gradually applied, which spreads the photopolymerizable sheet across the dammed portion of the platen. After uniformly dispersing the sheet metal, the temperature was raised to 160°C and 20,000-30.00Dps1 (14
A pressure in the range 06-2109 Kf/cm2) is applied and held for 3 minutes. The assembly is cooled in the press to below 60C by flowing water through the press platen. The formed laminated element is removed from the press and placed support side up in a lightless unit. The element is given a general exposure through the support in air at atmospheric pressure for 4 minutes to polymerize the predetermined thickness of the photopolymerizable layer adjacent to the adhesive support. This overlapping portion of the element is called the floor.

After removing the cover sheet, attach this element to Sylpania B.
L-WHO-Cyrel with fluorescent lamp
■) Place in J 3040 exposure unit (DuPont product). The image-containing transparency (negative) and the element are exposed under vacuum for 15 minutes. The duration of exposure is a function of the polymer sheet thickness, the thickness of the polymeric floor, and the type of image-containing aperture surface used.

After exposure, the transparency is removed and the exposed element is placed in a rotary drum plush tights "Shillel ■" 6040 processor. The unpolymerized portion of this element and the entire polyamide resin layer were processed in a processor for 15 minutes.
Remove by washing with 2-(2-butoxyethoxy) 0.5 weight polyhydroxide in ethanol/water followed by a 2 minute water wash or with a tetrachloroethylene/butanol (80/20) mixture.

A relief image of 0.035 inch (0.89 s+m) is obtained. Place the developer element (printing plate) in a forced hot air dryer or other suitable dryer and dry at 60°C for 15 minutes.

In the examples below, the following halogen treatment solution is used.

Bromine 20-11H to 1800-I tap water while mixing
Add Cl. Add to this solution with mixing 200 m of tap water, 10 f of potassium bromide and 2.82 m of potassium bromate (free bromine concentration 0.4%).

Iodine Add 6.4t potassium iodide and 12.7f iodine to 200d water.

! See 90- of Clorox (C1orox■) and 1
Add 0-concentrated (37%) Hct to 900 wIt of water (Na0Cl ~0.06 molar and HCl ~0
．． 12 molar concentration).

EXAMPLE 1 Post-expose the above exposed and developed frettage printing plate for 10 minutes in air using the same exposure source as used for the imagewise exposure. Plate is 56-6o
It has a Shore OA2 hardness in the range of . This plate was prepared as described below.
(non-halogenated) and immersed in various solvent mixtures and 10012-propertool for 24 hours. The strength of the solvent is increased by adding a large amount of ethyl acetate to the total 2-propanol. The plate is tested for solvent resistance as described in Ink/Solvent Compatibility Testing. The raw data values obtained are listed in Table 1 below. The calculated F values are listed in Table 2 below. The symbols in the table are as follows.

Solvent 1: 2-propatol I 2: 2-propatol (,95)/ethyl acetate (5
) # 6:2-propertool (90)/ethyl acetate (1
0) I 4:2-propanol (85)/ethyl acetate (
15) #5: 2-propertool (80)/ethyl acetate (20) treatment a': Br210 min, C120, 5 min'b
iBr 22 minutes, ct 20.5 minutes Ic: Br 210 minutes, ct 20.5 minutes (calculation) Yellow'
d: Br 22 minutes, ct 20.5 minutes (calculation) ■'e: Br
2j [1 min, no ct2 #f: Br+2 min* No C12'g: no Br2, no ct2 #h: Cl2O, 5 min, Br210 min 1 1
: C120, 5 minutes, Br22 minutes l j :
Cl2O, 5 minutes, without Br2 Note) Add the F values in Table 2 for the single treatments listed in yellow arithmetic to obtain the expected value of F for these treatments. 1 1 a 0 0 0.3
01 b O00,34 1e O,2-0,901,001f
0.3 -1.25 1.721 g
7.0 -11.5 5.511
h O,1-1,00,62f i
10.4 -10.0 4.641
j 7.6 -11.0 5.
542 a O,1=0.5 0.
712 bo, 2 -1.0
0.962 e yellow - 2f yellow - 2g yellow -2h
O,9-3,01,782129,0-16,
09,35 2pi - 3a O,1-1,01,37 3b O,3-2,01,51 3e O,8-2,03,05 3f 1.99 -2.25 5.76
3 g 25.2 -21.25
12.143 h 1.5 -
5.0 3.0?3 1 39.5
-17.0 14.793 j
35.5 -21.75 12.714
a 0.3 -2.0・2.
294 b 1.0 -3.25
2.754 0 winter yellow --- 4-t'-N% --- 4g arrow% --- 4h 30.6 -18.0 10.
314 1 44.9 -22.0
20.754 jle-5a 1.4-4.0
4.055 b 1.2
-4.0 4.915 θ
Ro, 5 -7.0 10.05
5 f 8.0 -16.
75 12.385 g 5
4.5 -25.5 23.60s
h 52.2 -22.0
17.205 1 54.5
-28.0 26.605 j
61.0 -23.0 22.9
1 (Note) ■ The F value in Table 2 is obtained by interpolating the curve between the value of solvent 1 and the value of solvent B.

The ν values in table 2 are obtained by curve interpolation between the values of solvent 3 and solvent 5.

Table 2 F values for solvents and treatments Treatment a O,990,9B 0.97 0
．． 95 0.85bO8990,980,950,9
20,800 yellow% 1. (IN O,900
,820,770,75a→0.99 0.89
0.79 0.70 0.53e O,
980, 960, 910, 850, 74f
O,960,950,880,780,52g
O, 740, 600, 430, 230, 0h
O,990,960,880,450,1210
,760,500,! +3 0.14 0.0j
O,770,540,340,150,01
(Note) Calculated from the raw data value of 1.HPc=F6+
(FjFg) → Fd = Ff + (Fj Fg) As can be seen from the values in Table 2, printing plates a and b treated according to the present invention are similar to similar printing plates e treated by a process other than the present invention. Especially when compared to ~j, the solvent is 1~
When the strength is higher than 5, the solvent resistance is excellent.

This plate also has excellent calculated C and D machining. In the very weak solvent 2-propertool, the calculated F values are essentially the same for two halogen treatments in either order.

The following Table 3 shows the data in Table 2, i.e. a in solvents 1 to 5.
It consists of the values of %b, c%d, h and j, which is the F during the halogen treatment of the present invention and the reverse order of treatment.
It shows the difference in value.

Table 3 F value for solvent and treatment” a O,990,9B 0.9
7 0.95 0.85cf Yellow 1.01 0.90 0
．． 82 0.77 0.75h
o, 99 0,96 0.88 0.45 0.12a
-Q::△Invention (measured value - calculated value) -0,20,080,15'0
．． 18 0.10b-c=Δ Reverse order (measured value - subtraction value) -0,020,060,06-
0,52-0,63bO8990,980,950,9
20,80d (transfer) colleague 0.99 0.89
0.79 0.70 0.53:I
O, 760, 500, 330, 140t) - d = Δ invention (measured value - calculated value) 0 0.09 0.16
0.22 0.271-d=ΔReverse h order (measured value - calculated value) -0,23-0,39-0,4
6-0, 56-0, 53 (Note) Calculated static F from the 10 raw data. =F6+(FjFg) The positive values observed in Table 3 for the difference between a-Q and b-d are due to the synergistic effect (superaddj tl
vlty). h -c and 1-(]
The generally negative values observed for Cloth 6 for the difference in % are indicative of the inferior results obtained when chlorination precedes bromine treatment.

Example 2 Expose and develop as described in Example 1.

A flexography printing plate that had been post-exposed and treated as described below was treated with Solvent 5 of Example 1.
Very strong n-butanol/n-zorobyl acetate (
80/20) into the solution.

The plate is tested for solvent resistance as described in Ink/Solvent Compatibility Testing. Obtain nine △T, ΔH and ↓ and Δ
The raw data value of %W is used to calculate the F value, which is listed in Table 4. The symbols for this process are the same as those described in Example 1.

Table 4 Processing Raw data [single processing] ΔT Hu Δ%WFj
71.6 -26.0 24.24 -0.
13f 8.0 -14.0 13.4
2 0.58e 4.5 -7.0 8
．． 99 0.75 [Treatment of the present invention] b '5.1 -5.0 6.
79 0.82a 2.1 -
4.0 5.27 0.86 [between pairs (reverse order)] 1 82.4 -26.0 25.7
5 -0.22h 72.1 -2
2.0 22.23 −0.06 [Expected result] d FiFj −−0,45c Fe+Fj
-0.62 difference? a-Fo=0.24 Excellence of the present invention compared to expected results Fb-Fd=0.37 'Fa-F
h = 0.92 Superiority of the present invention compared to the control Korean order Fb - Fj = 1.04 'As can be seen from the data above, the treatment of the present invention exceeds that expected from the sum of the individual treatments. The result is also better, and it is much better than the reverse order of processing.

Example 6 The post-exposed flexography printing plate described in Example 1 was
．． Bromine for 5 minutes, then chlorine for 30 seconds, rinse with water and dry. The plate is mounted using double-sided adhesive tape onto the printing cylinder of a Gargus Stanfort type Al 60 printing press (manufactured by Feldruch-Maschinenfafrik-Flinters & Engineers).

Polyethylene base material and n-propertool/n-propyl acetate) (80/20) Molten fl hese ink (Clark Graphics product, Cyanbruna SF
3 per minute using X-10833, batch 5279)
00 sheets and 12 hours of printing operation totals about 200,0
Gives a good quality print for a 00 good print. Control plates treated in bromine alone for 10 minutes give images of unsatisfactory quality after less than about 10,000 impressions or after a printing time of 15 to 30 minutes.

Example 4 Other printing plates are manufactured as described in Example 1,
Process and test as described in Ink/Solvent Compatibility Test. As shown in Table 5 below, the post-exposure step described in Example 1 is carried out before, during or after the two halogen treatments. The solvent is Solvent 5 of Example 1, i.e. 2
-propanol/ethyl acetate (90/10).

Treatment symbols a to j are the same as described in Example 1. pg
is a post-exposure. The other symbols k−”u are as follows.

For processing: Br20.25 minutes, CL2 0.25 minutes'
l: Br20.50min, CI20.50min'
m: Br20.50min%P"% CL2.0.
50 minutes'n:'Br20.5'0 minutes, no CL2#
o: Br20.25min, PK, C120,
25 minutes” p: Br20.25 minutes, no C12’C
L: C120, 25 minutes, B, r2 Lu r:
Br210.0min, PK, CL20.50min'
s: Br210.0 min, CL2 0.50 min, p
icl t: Br2 2.0 min, pm %c
t2 o, so min l u: Br22.0 min,
C120, 50 min, pg table 5 1 PJa O, 97 synergistic 1-8 = 0.1
32 PK%b O,95 Synergistic: 2-1
1=0.123 pg%f 0.93 4 PFi,e O,91s
pg%h O, 90 samples treatment F value extraction
Required 6 PKlk 0.85 7 PFi, 1 0.84 8 c O, 849m
0.83 101, PK 0.83 11 d O,83 12PJn O,81 13o O,80 14k%PK O,76 151k 0.72 16PI%P 0.55 17kkk 0.51 18 g 0.43 Control, no treatment 1
9 Pmelon g 0.39 20 PFIIj 0.34 21 F lice 1 0.33 (Note) ■Calculated values Samples 6.13 and 14 are the results when the order of pg is changed for bromine and chlorine treatment for 15 seconds. It shows the fluctuation of F value. As shown in Table 6, post-exposure is more effective when applied first, but it is effective in either order.

Table 6 (Note) ■ The subtracted F value is 0.51 for treatment k (sample 17) in Table 5.

Samples 7.9 and 10 show the variation in F value when changing the PR order for bromine and chlorine treatments for 30 seconds.

As shown in Table 7, there is little effect on varying the PK order.

Table 7 (measured value - calculated value arrow) m 0.8! + ΔThe present invention is 0.11 (
Measured value - calculated value) 1, PK 0.83 ΔThe present invention is 0.11 (
Measured value - Calculated value Kaoru) (Note) Yellow The calculated F value is 0.72 for Treatment 1 (Sample 15) in Table 5.

Example 5 The printing plate prepared in Example 1 is halogenated (iodine replaced by bromine) as described below, but one control is without halogenation.
After soaking in a solvent mixture of ethyl acetate (90/10) for 24 hours and tapping dry, the printing plate is tested for solvent resistance as described in the Ink/Solvent Compatibility Test above. The F value for each treatment is shown in Table 8.

Table 8 1 Engineering 2 (80) 0.43 3 None 0.43 5 0.34 Calculated from 1+(2-3) 7 Engineering 2 (105) 0.45 8 C12 (30) 0.34 Same as 2 above 9 None 0,43 Same as 6 above 10
I2 (105), 0.78 Invention C12 (3
0) 11 0.36 7+(8-9)
Calculated from 13 engineering 2 (138) 0.611
4 C12 (30) 0.34 Same as 2 above 1
5 None 0.43 Same as 6 above17
- 0.52 13+(14-15)
The results in Table 8 show that there is an improvement in the solvent tolerance of the plates when treated according to the present invention compared to the additive results of a single treatment. Processing 4-5.10-1
The difference results for 1 and 16-17 indicate that iodine treatment followed by chlorine treatment provides a synergistic improvement.

EXAMPLE 6 Printing plates prepared as described in Example 1 and treated with a%b1r, s%t and uK ethyl acetate as described in Examples 1 and 4 were treated with n-propertool/n-propyl acetate (80/ 20) for 24 hours and evaluated as described above. The results, listed in Table 9 below, show that the post-exposure following the two-step halogen treatment was significantly superior to the post-exposure at other points in the process for printing plates impregnated with the aggressive solvent. Show that there is. The results of this example differ from those obtained in Example 4, which used a less aggressive solvent 2-propanol/ethyl acetate (90/10) and a milder halogen treatment.

Table 9 a' 2.57-8.336.310.79r29.
00-j2. o 9.45 CJ, 66s30.80
-4.00 4.60 0.88b1 1
9.20 -14.50 11.33 (3,5
4t248.60-22.0021.060.12u6
2.40 -8.50 7.50 -0.77 (Note) 1) Early after exposure 2) Middle after exposure 3) Late exposure after exposure

Claims (1)

[Scope of Claims] 1) It has a number average molecular bond of 20,000 to 75,000, the acrylonitrile content thereof is 10 to 50% by weight, and the carboxyl permanent content is 0 to 15% by weight. Imagewise exposure of a photosensitive elastomeric composition layer comprising a high molecular weight butadiene/acrylonitrile copolymer and a non-gaseous ethylenically unsaturated compound containing at least one terminal ethylene group with actinic radiation and its unprotected state. In a method for providing an improved solvent-resistant surface to a relief light-sensitive flexographic printing plate in which the relief areas have been produced by liquid development of the exposed areas, optionally after drying the areas in relief, in any order (1) subjecting the developed surface to a source of actinic radiation; and (2) sequentially subjecting the developed surface to two aqueous halogen solutions, i.e., free bromine concentrations ranging from 0.01 to 3.5 wt. having about 15
Aqueous bath solution or 0.2 to 10 minutes with contact for seconds to 20 minutes
A first halogen solution, either an aqueous solution with a contact time of about 1,0 to 10 minutes, with a free iodine concentration of % by weight followed by a molar concentration of <0.01 to 1,0 NaCl
and a second halogen solution for a contact time of about 15 seconds to 5 minutes of chlorine equivalent to that provided by an aqueous solution of 0.012 to 1.2 molar HCl. 2) The method according to claim 1, wherein the printing plate is first contacted with an aqueous bromine solution and then with an aqueous chlorine solution. 3) A method according to claim 1, wherein the printing plate is first contacted with an aqueous iodine solution and then with an aqueous chlorine solution. 4) A method according to claim 1, wherein the aqueous bromine solution is prepared by mixing bromine and an alkali bromate-bromide-acid mixture in water. 5) sequentially from the bottom upwards (4) the flexible support; (B) based on the total weight of the composition (a) 55 to 90 wt.
00, its acrylonitrile content is 10-50% by weight and its carboxyl content is 0.
~15% by weight of a high molecular weight butadiene/acrylonitrile copolymer, (b) capable of forming a high molecular weight polymer by free radical initiated chain extension addition polymerization of 2 to 40% by weight and compatible with said polymer (a). (c) a non-gaseous ethylenically unsaturated compound containing at least one terminal ethylenic group; (d) a photosensitive elastomeric composition layer containing 0-1sii% of a compatible plasticizer; (c) a flexible polymeric film; (D) a removable cover sheet and optionally a p-layer ( A flexographic printing plate is produced by imagewise exposure and liquid development of a photosensitive elastomeric element comprising a layer of adhesive composition present between layer (B) and layer (B). The method described in section. 6) A method according to claim 1, wherein the developed surface is aqueous developed and the halogen treatment is carried out without drying the developed surface.