SE444991B - PHOTOPOLYMERIZABLE COMPOSITION AND SUBSTRATE COATED WITH THE COMPOSITION - Google Patents

Description

15 20 25 30 35 vsosvosfe 2 Such elements are relatively oxygen insensitive (P Q a barrier layer) and with the appropriate choice of barrier layer they can be developed with basic solutions after exposure.

These elements remain relatively slow and require additional coating operation to generate the barrier layer. In addition to the time and cost factors resulting from the coating operation, careful control of solvents and conditions in this step must be observed to avoid sensitometric damage to the photosensitive layers.

Other radiation-sensitive compositions known in the art include those in U.S. Pat. No. 3,827,956.

This ultraviolet radiation sensitive composition comprises 1) an acrylic monomer (eg pentaerythritol triacrylate), 2) an acrylate oligomer (eg the reaction product between toluene diidocyanate and two equivalents of 2-hydroxyethyl methacrylate) and 3) a halogenated polynuclear lactone catalyst. U.S. Pat. Nos. 3,297,745, 4,017,649 and 4,065,627 disclose other acrylate end-capped urethane oligomers which can be homopolymerized or copolymerized with other ethylenically unsaturated compounds. These materials are photopolymerizable with relatively high radiation sensitivity and low oxygen sensitivity, but they are not base-soluble and are therefore not useful as base-developable printing plates. These compositions also have poor bonding properties to metal surfaces, such as zinc and aluminum.

It has now been found that radiation-sensitive high-speed photopolymerizable compositions with excellent adhesion to certain substrates, especially aluminum surfaces, which compositions are suitable for use in radiation-sensitive printing plates and color swatches, can be prepared. These compositions can also have significant storage stability and insensitivity, and the polymers I prepared therefrom are hard and have a long service life; The compositions are also base soluble and can be developed in basic solutions in sheet metal processes. The photosensitive compositions of the present invention comprise 1) an ethylenically unsaturated radical polymerizable end-capped oligomer, in which the bridging oligomer moiety between the unsaturated end groups i has carboxyl group substitution, 2) a polymeric binder substituent. 3) at least one radical polymerizable monomer having at least one ethylenically unsaturated group and 4) a radiation sensitive initiator system capable of initiating radical polymerization upon absorption of electromagnetic radiation.

A storage stable photosensitive image generating element with particular use for providing base developable printing plates can be prepared by applying the photosensitive compositions of the present invention to a backing layer.

Particularly improved compositions comprising the photosensitive oligomers, limited classes of binders, polymerizable monomers and photoinitiation systems have unexpectedly high radiation sensitivity and no oxygen or moisture sensitivity.

There are four essential constituents in the radiation sensitive compositions of the present invention, namely 1) an oligomer, 2) a binder, 3) a polymerizable monomer and 4) a photoinitiation system. All these four materials must be present in the polymerizable composition in order for it to work well in photoimageable recording elements, such as in lithographic printing processes. The compositions comprise per 100 parts in total: 10 to 60 parts by weight of oligomer, 10 to 50 parts by weight of binder, 10 to 60 parts by weight of monomer, and 0.1 to 12.0 parts by weight of photoinitiator systems.

As a photoinitiator system, it is preferred to have a photosensitizer and a compound which, when photosensitized, can initiate radical polymerization. In the practice of the present invention, the second compound is defined as an initiator. The photoinitiator 0.5-10 system is even more preferably present in a variety of parts. Preferably, the photosensitive composition per 100 parts comprises in total: I 15 - 45 parts by weight of oligomer, 15 - 35 parts by weight of binder, 25 - 50 parts by weight of monomer, 0.2 '- 10 parts by weight of initiator (more preferably 2 - 8), 0.1 - 5 parts by weight of photosensitizer (preferably 1-4).

Most preferably, the compositions of the present invention comprise per 100 parts in total: u 20 "- 35 parts by weight of oligomer, 20 - 30 parts by weight of binder, 30 - 50 parts by weight of monomer, 2 - 6 parts by weight of initiator and 1 - 3 parts by weight of photosensitizer.

In general, the photosensitive compositions of the invention are prepared by mixing the components in a low boiling (boiling at less than about 150 ° C at atmospheric pressure) polar solvent which is not reactive with carboxyl groups or ethylenically unsaturated groups such as methanol, ethanol. promethylethyl ketone, tetrahydrofuran or panol, acetone, if present in water, mixtures thereof. Even less than 50% by weight of water in the solvent may be preferred. The amount of solvent used (usually 0-98% by weight, preferably 10-96% by weight and in lithographic applications preferably 85-95% by weight of solvent) depends on the desired viscosity and the desired coating thickness. It is often desired to add a surfactant or a coating aid, but including the solvent, it is not required but only these aids, in order to functionally practice the invention, are better modes of exercise. 0.001-2% of surfactant, in particular, silicon or fluorocarbon active agents, is usually sufficient. These compositions may contain any number of additional useful additives, such as dyes, pigments, coating aids, surfactants, etc. The coating weight of the compositions of the present invention is usually 0.3-9 g / m 2, preferably 0.5-5 g / m 2 and most preferably 0.8-2.4 g / m 2. Suitable substrates include resin-coated papers, various transparent or opaque plastic sheets or films, metal sheets and foils (preferably aluminum substrates, which have been wound and anodized). The coated substrates must be kept in the absence of light unless the oil element is sensitized to a narrow electromagnetic spectrum area outside the normal light range and the element is provided with a filter layer which excludes normal visible light.

The preferred use of the photopolymerizable compositions of the present invention is as a presensitized sheet for use in printing operations, such as in the formation of lithographic sheets.

This structure comprises a veined and anodized aluminum substrate coated with 0.3-9 g / m 2 of the compositions of the present invention. Veined substrates are surfaces that have been textured or roughened. is well known in the art and can be accomplished by This treatment - vein removal (roughening with an abrasive), chemical etching or electrochemical veining. Anodizing is the well-known anodizing of metal surfaces. Polymeric topcoat layers used in these designs must be soluble in aqueous alkaline solutions of pH 8-13, such as the aqueous developers of the examples.

A general structural formula of the urethanol oligomers can be drawn as follows: wherein (O) is an ethylenically unsaturated, radical polymerizable group, preferably selected from acryloyloxyalkoxy (alternatively designated acryloxyalkoxy), methacryloylalkoxy (alternatively designated methacryloxyalkoxy), vinylalkoxy and allyloxy, D is the remainder of a polyisocyanate [preferably a diisocyanate) having at least two of its groups -N = C = to form -NHC groups, where D binds E to R, A is a carboxyl-II O 'OO axis! II 'acid-containing group (eg% CH2) mC' d \\ * oH a is a tai with an average value ev 2-zo, b is a number with an average value of 0.3-10 and m_ = 1-6, R is the residue of a polyol having at least a + b hydroxyl groups and an average molecular weight based on the number of 90-10,000, which residue is formed by removing hydrogen from the hydroxyl groups.

The backbone of the oligomer, group R, may be any aromatic or aliphatic polyol having a molecular weight of 90-10,000. The backbone of the oligomer may be any oligomer having the stipulated molecular weight and number of hydroxyl groups, but polyester polyols and polyoxyalkylene polyols are preferred.

Linear oligomeric polyols are useful, but the branched or three-dimensional polyols, such as polycaprolactone polyols, are preferred. The backbone can be prepared by any of the many well known methods for forming polyhydroxyl substituted oligomers having a molecular weight of 90-10,000. hydroxy equivalent weight of 45-5000 to be usable according to the present invention Preferably, the polyol has a hydroxy equivalent weight of 90-4000 and most preferably zoo-2006. "" I ", The oligomeric backbone may be homopolymer, copolymer; graft polymer or mixtures thereof. For example, "W polycapraglactone polyols may be used or polyprolactone polyols of lower molecular weight (average molecular weights of less than eg SO 2) may be combined with polyacids (preferably dicarboxylic acids) or with polyisocyanates (polyisocyanates). preferably diisocyanate) to form higher molecular weight oligomer backbones.

In the synthesis of the oligomers useful in the present invention, it is preferred to combine the ED substituent with the oligomeric backbone R by first separately forming an adduct of the polyisocyanate, of which D is a residue, by reacting one mole of the diisocyanate with one mole of an ethylenically unsaturated radical polymerizable monomer having a hydroxyl group. The adduct formed is then reacted with a hydroxyl group on the oligomeric polyol backbone (the reaction proceeds with an isocyanate group). In an alternative method, where the compound having the radical polymerizable group having a hydroxyl group and the polyisocyanate is added to the oligomeric polyhydroxy backbone before the E-D adduct is formed, the polyisocyanate will act both as a polymer extender for the oligomer and as an adduct former with the radical-containing compound. In such a reaction, there is much less control over the final product and there is a tendency for the oligomer to form a gel. Therefore, in a independently performed synthesis, the radical polymerizable monomer and the polyisocyanate (preferably diisocyanate) form, for example, an isocyanatoalkyl acrylate, isocyanatoalkyl methacrylate, an isocyanatoalkyl ether or an isocyanatoalkyl vinyl ether product.

The adduct (E-D) formed in this step is then reacted with the polyhydroxy-containing novel chain, so that the remaining isocyanate group in the adduct reacts with some, but not all, of the hydroxyl groups on the oligomer to bond to it.

The carboxylic acid groups are added to the oligomer backbone, preferably after the addition of the radical polymerizable moieties by reaction between residual hydroxyl groups on the oligomer backbone and a compound having free carboxyl groups. Preferably, such a compound is a dicarboxylic acid or anhydride, so that the bridge bond to the oligomer backbone becomes an ester group. An isocyanate bridge can be formed by first preparing an acid-isocyanate adduct.

A more detailed formula for the preferred oligomeric materials is as follows: O (E-D-R1 + aR2- + R1-É-R3-É-one) b wherein D, a and b have the same meaning as above,. 0 'E is selected from + cH2 + no-c-o = cH2, + cH2 + no-c = cn2' and in R4 12.4.

+ CH2 + nO-CH2-CH = CH21 where R4 is -H or -CH3 and n is an integer, of 2-4, In R1 is the residue formed by the removal of active hydrogen atoms and hydroxyl groups from oligomeric Q-hydroxy-Carboxylic acids or the residue formed by removal of the active hydrogen atoms and hydroxyl groups from oligomeric diols, R2 is a residue having a valence of plus b, of an aliphatic polyol of the formula R5 (OH) a + b after removal of a + b hydrogen atoms from the hydroxyl groups, or a polyol of the formula 5 (Hæziíl-R '°' D '°' R <° H> ana-1 2 2 after removal of a + b4]. hydrogen atoms from hydroxyl groups, wherein R5 is the remainder of an aliphatic polyol radical formed by removing the OH groups therefrom with 3-10 valences substituted with OH groups and which may have one or two ether oxygen atoms in the aliphatic backbone, and - O 'II R3 is the remainder of a dicarboxylic acid with both -C-OH groups removed therefrom., f, .........._._-.._.._..._.._ .. ._..-... _.,. 7903709-9 9 Before typically the molecular weight of (R1 + aR2 (R1) b is 200-5000.

Particularly desirable aliphatic polyols from which R 2 is formed are polyether polyols, polyester polyols, polylactone polyols, polyolefin polyols, polydiene polyols, polysiloxane polyols, poly (alkyl acrylate) polyols and poly (glycidyl ether) polyols. A particularly desirable material has the structural formula HI - N [H00-H3-co} ¿-nïfocwn-R6 ~ Nnco4cH2 + ¿occ = cH2] p RH 3 and R4 have the same meaning as above, wherein R c is 2-5, number average of 2-7.7, g is a number average of 0.3 ~ 4, R6 is the residue of a diisocyanate with two -N = C = 0 groups removed therefrom and is preferably an aromatic residue thereof, and in R7 is a organic triyl radical, which is the remainder of an organic polyol having at least three hydroxyl groups removed therefrom and having a molecular weight of 90-10,000, preferably selected from aliphatic triols, tetrols and pentols, poly (oxyalkylene) triols, tetrols and pentols, polyester triols , -tetrols and pentols, polylactone triols, tetrols and pentols, polyolefin triols, tetrols and pentols, polyacrylate triols, tetrols and pentols, polyalkyl acrylate triols, tetrols and pentols and polysiloxane triols, ethetrols.

Another particularly desirable material can be represented by R_ 15 20 25 30 35 7903709-9 10 .in ¿"Ošfrécëgdolel-Ríco fl fo NH! O (CH) c o-R9 2 de .ü IO oêcéc fl gaäoäê fi munóuníoçc fi êaëocï-CH2 Ru is wherein R 3 and R 6 have the same meaning as above, d is 1-6, e is an average of 0.5-5, f is an average of 1-6; R8 is the divalent hydrocarbon radical which is the residue of an organic polyisocyanate (preferably diisocyanate) with two isocyanate groups removed therefrom, R9 is an alkane polyol radical having a valence of h + 1 which is the residue of an alkane polyol having h3 + 1 hydroxyl groups removed therefrom + 1 hydroxyl groups before removal), which alkane polyol 'has a molecular weight of 100-10,000 and preferably 200f2000, wherein h is an integer from 2-8; The general method of preparing the oligomers of the present invention is as follows: Step 1 - Preparation of a one-to-one adduct of a (radical polymerizable) hydroxyalkyl material and a polyisocyanate, preferably a diisocyanate.

This is accomplished by reacting the two materials in a one-to-one phthalate, Step 2 - Reaction between an organic polyol having β-hydroxy groups and up to X to 1 mole of the adducts. 7905709-se ll from step 1. This forms a urethane oligomer with both ethylenically unsaturated groups and at least one free hydroxyl group. Although some individual oligomer moieties in this reaction may, of course, have all of the X hydroxyl groups reacted with the isocyanate, by controlling the proportions of the isocyanate adduct and the polyol, the average number of free hydroxyl groups on the urethane oligomer becomes at least one.

Step 3 - The free hydroxyl groups on the product from step 2 are esterified with a polycarboxylic acid (preferably a dicarboxylic acid and preferably an anhydride of a diacid). This reaction forms the carboxyl-substituted, ethylenically unsaturated urethanol oligomer of the invention. The adduct between the hydroxyalkyl acrylate and the diisocyanate from step 1 has the general formula:. Wherein R, R, R 6 are preferably tolyl and R 10 is an aliphatic group and preferably (CH 2) 2 -6.

It is preferred to use diisocyanates such as and a have the same meaning as above and tolylene-2,4-diisocyanate and isophorone diisocyanate due to the large difference between the reactivities of the isocyanate groups thereon. Without this difference the product would need to be purified or else gain less control over the product obtained.

Such adducts are prepared by adding about 0.9 to 1.1 molar equivalents of the hydroxyalkyl acrylate to one mole of organic diisocyanate while stirring the reaction mixture. It is usually desirable to keep the temperature below about 30 ° C during the addition.

The reaction may be terminated after stirring the mixture for 10 minutes to 1 hour or more. If it is not completed so rapidly, the reaction can be terminated by further heating the mixture at temperatures of SOOC or more for at least 1 hour. Since many of the reaction products are viscous liquids or solids (the reaction product between 2-hydroxyethyl methacrylate and 2,4-toluene diisocyanate is a solid) it is preferred to add 0.25 to about 35 parts by weight of a solvent containing no functional group, such as methyl ethyl ketone, acetone , tetrahydrofuran or the like. The solvent may be added at the beginning of the reaction with the addition of the hydroxyalkyl acrylate. Although not always necessary, it is often desirable to add a catalyst to effect reaction between the hydroxyl group of the hydroxyalkyl acrylate and one of the isocyanate groups of the organic diisocyanate. Suitable catalysts for the reaction are well known; an example of such is dibutyltin dilaurate. Step 2 is accomplished by either adding the product from step 1 to a organic polyol, as defined above, over a period of 1-5 hours or more, while heating the mixture at about 50-10 ° C. or vice versa. As in step 1, a catalyst such as dibutyltin dilaurate can be used to facilitate the reaction. It is often desirable to add a polymerization inhibitor, such as 2,6-di (t-butyl) -4-methylphenol, to prevent premature polymerization.

The ratio of the diisocyanate-hydroxyalkyl acrylate adduct to the organic polyol is selected so that one mole of oligomer obtained in the reaction contains at least two acrylic acid groups but leaves at least 0.3 equivalents of unreacted hydroxyl groups. Step 3 is carried out, usually without isolation, of the product of step 2 by esterification of unreacted hydroxyls in the product of step 2 with an anhydride of a dicarboxylic acid. Preferably, the esterification is accomplished by adding an amount of an anhydride of a dicarboxylic acid, such as preferably succinic anhydride or adipic anhydride, and further heating to 50-110 ° C for 3 to about 10 hours, wherein the higher the temperature the shorter the heating time required. Depending on the extent of the desired carboxylation, from about 0.3 to about 4 moles of anhydride are used per mole of organic polyol originally present in the reaction mixture. However, the esterification can be carried out by using instead of the anhydride an ester of the dicarboxylic acid, namely the methyl or ethyl ester, and by ester exchange distillation of the formed corresponding methanol or ethanol.

The esterification can also be carried out by using other reactive derivatives of the dicarboxylic acid, such as the die acid chloride, and removing the hydrogen: chloride formed. Sometimes it is necessary to add a hazardous catalyst, such as lithium acetate, to increase the rate of this reaction.

Regulating the ratio of the number of acid groups (carboxylic acid groups) on the oligomer to the gram molecular weight of the oligomer is an effective way to regulate the binding ability of the composition to a substrate after photoinitiated reaction. With increasing acid concentration, the composition is more easily removed upon development.

A wide range of this ratio can be used depending on the desired properties of the final product.

A composition with a molecular weight to acid group ratio of 67-17,000 is useful. It is preferred that the ratio of molecular weight to acid groups in the oligomer be 500-S000 and preferably 800-3000.

The second of the critical elements in the photopolymerizable compositions of the present invention is the binder. This material is an organic film-forming polymer having a molecular weight of at least 6,000, preferably 12,000 and most preferably at least 15,000. It is desirable but not essential to the practice of the present invention that the binder have a labile hydrogen or easily separable hydrogen. The polymer preferably has a molecular weight not greater than 100,000, preferably not greater than 80,000 and most preferably not greater than 50,000, although binders having molecular weights of up to 2,000 ooo or 3 ooo ooo are well known in the art. To be a labile or easily separable hydrogen, a hydrogen in the binder must be bonded to a carbon atom with an adjacent heteroatom selected from N, S, Se and 0. Preferably the heteroatom is N, S or 0; It is also preferred that the carbon having the readily separable hydrogen is a heterocyclic 5-, 6- or 7-membered ring, consisting of C, N and O atoms, with preferably two heteroatoms adjacent to the carbon atom having the labile hydrogen.

The carbon atom bearing the labile hydrogen may be primary, but is preferably secondary or tertiary. The greater the separability, the lower the proportion of binder the composition needs, even if there is not necessarily a linear relationship. Preferred binders are the polyvinyl acetals, such as polyvinyl formal, polyvinyl butyralph and mixtures thereof. Polyvinyl methyl ether, polyvinyl alcohol, hydroxyalkylcellulose (eg hydroxypropylcellulose), polyamides, polyvinyl acetate, polyvinyl acetate-polyvinyl chloride copolymers, polyethylene oxides and polyacrylate (eg polyalkyl methacrylate have also been shown to work well). The rate or quantity efficiency of the double bond conversion (ie the polymerization) and the photosensitivity of the various coatings when exposed to air is a function of the type of polymeric binder used.

While some polymers do not provide the composition with the desired speed or photosensitivity, many polymers have been found to provide surprisingly large increases. Among the polymers which have been found to increase the rate of conversion of double bonds include polyvinyl acetals, polyvinyl alcohol, hydroxyalkylcellulose (eg hydroxypropylcellulose), polyamides, polyvinyl acetate, polyvinyl acetate vinyl chloride, polyethylene oxide and polyethylene oxide. Polymers that do not give an increase include certain aliphatic hydrocarbon resins, cellulose acetate butyrates, certain polyurethanes, such as Estaneç), and linear saturated polyesters.

Those skilled in the art will appreciate that not all rate-increasing polymers are necessarily the best binders for lithographic sheet coatings, although they are still useful and desirable in other imaging processes, such as duplication film and proofing systems. Other properties, such as solubility, water sensitivity and adhesion, must be considered in the choice of polymeric binder for lithographic plates.

The exact function of the binder in the compositions of the present invention is not clear. The labile hydrogen on this is believed to be desirable, since many materials without labile hydrogen do not prove to work as well as those with labile hydrogen; although some actually work well. In addition, oxygen barrier properties may be desirable in the binder polymer, but such properties are not known to be essential. Another of the critical materials in the photopolymerizable compositions of the present invention is the monomer. This material is a radical polymerizable monomer having one or more ethylenically unsaturated groups and preferably 2-4 ethylenically unsaturated groups, such as acrylate, methacrylate, vinyl and allyl. Preferred compounds are those having several acrylate and methacrylate groups, for example acrylic acid esters of low molecular weight polyols, such as trimethylolpropane triacrylate, pentaerythritol tetraacrylate and triacrylate, etc. Preferably, these monomers have a molecular weight of less than 2000 ° C. ...

Suitable radical polymerizable monomers useful in the compositions of the present invention are well known and are listed in many patents, for example, U.S. Pat. Nos. 3,895,949 and 4,037,021. Preferred monomers include polyacrylate. and the polymethacrylate esters of alkane polyols, for example pentaerythritol tetraacrylate, tris (2-acryloxyethyl) isocyanurate, tris (2-methylacryloxyethyl) Hisocyanurate, 2-acetoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 1-acrylaxyl -dioxabicyclo [3.0.0] octane (ADOZL bis [4- (2-acryloxyethyl) phenyl] methylmethane, diacetone, acrylamide and acrylamidoethyl methacrylate.

The compositions of the present invention must also have a radiation sensitive system that can initiate radical polymerization after absorption of radiation.

Radical initiators are materials known in the art, such as by Free-Radical Chemistry, D. C. Nonhebel, and J. C. Walton, University Press (1974). Particularly suitable radical generators can be selected from many classes of organic compounds including, for example, organic peroxides, azo compounds, aromatic diazonium salts, aromatic iodine salts, aromatic sulfonium salts, aromatic phosphonium salts, quinones, benzophenones, nitrosophenides, aryl halogens, aryl halogens, acrylyl halides , triarylimidazoles, diimidazoles, chloroalkyltriazines, etc. These materials generally must have photosensitizers in combination to form a photoinitiator system. Photosensitizers are well known in the art.

Further descriptions of known radical photoinitiator systems for ethylenically unsaturated compounds are found in U.S. Pat. Nos. 3,887,450 (eg, column 4), 3,895,949 (eg, column 7) and 4,043,819. Preferred initiators are the onium salts described in U.S. Pat. Nos. 3,729,313, 4,058,400 and 4,058,401.

Other desirable initiators are diimidazoles (described in U.S. Patent No. 824,733, filed August 15, 1977) and chloroalkyltriazines described in U.S. Patent 3,775,133.

These references also describe sensitizers. Another good reference to photoinitiator systems is Light--Sensitive System, J.-Kosar, 1965, J. Wiley and Sons, inc., Especially Chapter 5. 10 15 20 25 30 35 7903 7Û9 ~ 9 17 Preparation I A polycaprolactone hexol is prepared for use in forming a carboxyl-substituted urethane oligomer. 63.5 g of dipemerythritol, 228 g of epsilon-caprolactone and 0.02 g of 2,6-di-t-butyl-4-methylphenol (as an oxidation inhibitor) were added to a 500 ml three-necked flask which had been fitted with a mechanical overhead stirrer and a condenser. The liquid was freed from oxygen by bubbling with dry hydrogen gas from a gas dispersion tube for 20 minutes. This tube was then replaced with a gas introduction additive and the reaction mixture was heated while maintaining a slight overpressure with nitrogen gas. The mixture is stirred at 17 ° C for 1 hour while stirring is continued. The reaction mixture was then allowed to cool to room temperature under a nitrogen atmosphere. This material is designated P-I. This procedure is similar to that of U.S. Pat. No. 3,169,945.

Preparation II A urethane oligomer (hereinafter referred to as P-II) was prepared according to the following procedure.

A 1000 ml three-necked flask was equipped with an additive, mechanical stirrer, thermometer, hopper and drying tube. To this flask were charged 175 g of polycaprolactone-hexol P-I and 60 ml of methyl ethyl ketone. A solution of 13 g of 2,4-tolylene diisocyanate in 9 ml of methyl ethyl ketone was slowly dropped into the first solution with stirring at room temperature. The addition was complete in 20 minutes and the reaction mixture was stirred for 90 minutes at 30 ° C, after which infrared spectroscopy showed that essentially all isocyanate had reacted.

To a second flask equipped with an overhead mechanical stirrer, thermometer, hopper and drying tube was charged 86.1 g of 2,4-tolylene diisocyanate. To the addition funnel were added 70.2 g of 2-hydroxyethyl methacrylate (hereinafter 7HEMA) and 0.02 g of the inhibitor from the previous preparation at 35? 9os109 + 9 - 18 position to which was then added slowly with stirring to the diisocyanate while the temperature was kept below or at 30 ° C. The addition was complete in 15 minutes and after 40 minutes of reaction time a white solid formed. The solid was dissolved in 45 ml of methyl ethyl ketone by heating to 4500 and kept at this temperature for 10 minutes to complete the reaction. The flask containing the reaction product (adduct) between the polycaprolactone hexol (PI) and the 2,4-tolylene diisocyanate was heated to 67 ° C. and the solution of the HEMA / 2,4-tolylene diisocyanate adduct in methyl ethyl ketone was added slowly with stirring over a period of 2 hours. 27 g of succinic anhydride were then added together with an additional 0.2 g of the inhibitor. heating and stirring were continued until the anhydride had completely reacted (about 5-6 hours). a The final product is a carboxyl-substituted urethane oligomer, P-II.

Preparation III The preparation of a second carboxyl-substituted urethane oligomer is described here. To a 500 ml three-necked flask was charged 29.2 g of a poly (propylene oxide) triol having a molecular weight of 740, 25 ml of ethyl acetate and 0.007 g of methylhydroquinone as reaction inhibitor. The flask was heated in a 65 ° C oil bath with stirring and 13.0 g of HEMA and 17.4 g of tolylene diisocyanate were added simultaneously from addition funnels.

After adding half of these reactants, the reaction mixture was stirred for another 30 minutes. Then 0.001 g of SnCl 2 catalyst and 0.004 g of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate were added.

The reaction mixture was stirred for an additional 30 minutes and then the residue of HEMA and the diisocyanate was added slowly. Stirring was continued overnight. Infrared analysis showed no free isocyanate groups after this time. 10 15 20 25 30 35 '79U37ü9-92 »19 point. To this reaction mixture was added with stirring 1.4 g of succinic anhydride. The temperature was raised to 93 ° C and maintained there until the anhydrate had completely reacted. The mixture was then cooled and diluted to such a weighted solution of P-III oligomer in ethyl acetate. A 250 ml flask was charged with 21.2 g of a polycaprolactone polyol having a molecular weight of about 540, 25.1 ml of ethyl acetate and 0.007 g of methylhydroquinone as antioxidant. 17.4 g of tolylene-2,4-diisocyanate and 13.0 g of 2-hydroxyethyl methacrylate (HEMA) were added separately to feed funnels on the flask, the polyol solution was heated to e7 ° C and the isocyanate and HEMA were added dropwise with rapid stirring until half of each material was added. the heating for 30 minutes 0.002 g of SnCl 2 and 0.008 g of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate were added and the solution was stirred for a further 30 minutes The residue of the diisocyanate and HEMA was added dropwise and then another 5 ml of ethyl acetate was added. The mixture was stirred at 67 DEG C. Overnight, when isocyanate could no longer be separated by infrared analysis, 1.4 g of succinic anhydride were added together with 10 ml of ethyl acetate, the temperature was raised to 100 DEG C. and reacted. the anhydride was detected by infrared analysis as substantially complete after 5 hours.

This resulting material, a carboxylic acid substituted urethane oligomer, is referred to as P-IV and is useful in the practice of the present invention.

Preparation V A particularly useful binder material for oligomers was prepared as follows. A low molecular weight polyvinyl alcohol (88% hydrolyzed polyvinyl acetate) is reacted with butyraldehyde and acrolein using an acid catalyst, preferably sulfuric acid. The proportions between the reactants were 100 / 43.2 / 6.4.

The bridge product precipitated from water with dilute weakly basic solution (NaHCO3). Analysis of the product showed that the empirical formula was close to that based on the stoichiometry of the reaction, c - JCH3 4cH2- H) 5 M (CHE1 / "\ ï-èš-74cH2-cH% § 'oo '- -E / ^ \ Ä 1 É / eng CH CH 2 2053' _ This material is referred to below as PV.

Preparations VI-XI 'V An additional six oligomers were prepared to evaluate the present invention.

P ~ VI was prepared by first placing 128.8 g of 2,4-toluene diisocyanate in a three-necked 250 ml flask equipped with a mechanical stirrer and a pressure equalizing dropping funnel. The flask was kept at room temperature with a water bath. 106.6 g of hydroxyethyl methacrylate and 0.089 g of butylated hydroxytoluene and 100 g of methyl ethyl ketone were added slowly over a period of 30 minutes. The reaction mixture was stirred for 1 hour at room temperature. Nethyl ethyl ketone was added and the reaction mixture was heated to 45 ° C for 3 hours to complete the reaction.

P-I (350 g of 79% solids in methyl kiketone) was placed in a 500 ml three-necked flask equipped with a mechanical stirrer, pressure equalizing dropping funnel and 26.0 g of 2,4-toluene diisocyanate were added over a period of 30 minutes. The temperature rose to 32 ° C. The mixture was cooled to room temperature and stirred over the weekend. The first reaction product from the above synthesis was added over a period of 4 hours to this second solution which had been heated to 65 ° C. Heating was continued for 10 hours to form the second reaction product. 1.8 g of succinic anhydride and 0.1 g of lithium acetate were added to 112.4 g (71% solids in methyl ethyl ketone) of the second reaction product and the whole mixture was heated to 78 ° C for 12 hours to complete the reaction and to form the oligomer P-VI.

P-VII is prepared by placing 112.4 g (71% solids in methyl ethyl ketone) of the second reaction product in the preparation of P-VI in a 500 ml three-necked flask with stirrer and condenser and then adding 2.4 g of succinic anhydride and 0.1 g of lithium acetate. The mixture was heated to 78 ° C for 12 hours until the reaction was complete to form P-VII.

P-VIII was formed by placing 112.4 g (71% solids in methyl ethyl ketone) of the second reaction product in the preparation of P-VI in a 500 ml three-necked flask with stirrer and condenser together with 5.5 g of succinic anhydride. and 0.1 g of lithium acetate.

The reaction mixture was then heated to 78 ° C for 32 hours until the reaction was complete to form P-VIII.

P-IX was formed by first producing a polycaprolactone hexol by introducing 342 g of caprolactone and 127 g of dipentaerythritol into a 1000 ml reaction vessel equipped with a thermometer, mechanical stirrer and condenser. The reaction mixture was freed from oxygen by bubbling dry nitrogen through a gas dispersion tube for about 30 minutes. The gas dispersion tube was then replaced with a gas supply batch and the reaction was maintained under slight pressure of nitrogen gas. The reaction mixture was heated in an oil bath at 165 DEG-160 DEG C. with continuous stirring for 24 hours. The product was allowed to cool to room temperature under a nitrogen atmosphere. 141.0 g of the polycaprolactone hexol and 50 g of methyl ethyl ketone were placed in a 1000 ml flask equipped with a pressure equalizing dropping funnel and a mechanical stirrer.

This solution was kept at room temperature using a water bath while 2,4-toluene diisocyanate (13.0 g) in 20 g of methyl ethyl ketone was added over a period of 25 minutes through the dropping funnel with continued stirring.

Stirring at room temperature was continued for 22 hours to give the second reaction product. '. 38.2 g of 2,4-tcluene diisocyanate and 0.2 g of butylated hydroxytoluene were introduced into a 250 ml three-necked flask equipped with a mechanical stirrer, pressure equalizing dropping funnel and thermometer. 31.2 g of hydroxyethyl netacrylate were added with continued stirring over a period of 15 minutes at a temperature below 30 ° C. The mixture was stirred for 1 hour and a white solid formed. 20 ml of methyl ethyl ketone were added and the mixture was heated to 45 ° C for 3 hours to complete the formation of the third reaction product. 69. 7 g of the second reaction product and 0.02 g of butylated hydroxytoluene were added to a 500 ml three-necked flask with a mechanical stirrer, condenser and pressure equalizing dropping funnel. This solution was heated to 69 ° C with continuous stirring. The entire third reaction product was added to this solution over a period of 1 hour. Heating and stirring were continued for 13 hours to produce the fourth reaction product. 13.0 g of succinic anhydride and 0.4 g of lithium acetate were added to the fourth reaction product, and the solution was heated at 70 ° C-80 ° C with continuous stirring to produce P-IX. 7 P-X was prepared by first forming a polyol by placing 93.1 g of tripentaerythritol and 303.2 g of caprolactone in one liter of reaction vessel equipped with a mechanical stirrer, condenser and thermometer. The reaction mixture was purged with dry nitrogen for 30 minutes and a gas inlet pipe was attached to the vessel. Nitrogen gas overpressure was maintained over the reaction mixture when it was heated to 165-170 ° C for 9.5 hours, after which it was allowed to cool to room temperature. 300 g of this polyol and 75 g of methyl ethyl ketone were introduced into a 1000 ml flask equipped with a stirrer, dropping funnel and thermometer. 16.4 g of 2,4-toluene diisocyanate were added through the dropping funnel over a period of 10 minutes.

The temperature of the mixture rose to 28-32 ° C and the reaction was continued for about 3.5 hours to form the first reaction product. 153 g of this product (as 80% solids in methyl ethyl ketone) were added with 0.04 g of butylated hydroxytoluene in a flask and heated to 65-70 ° C. For a period of 2 hours, the third reaction product of Preparation IX was added to this solution and heated for a further 3 hours. 18.5 g of succinic anhydride and 0.5 g of lithium acetate were added to the above solution, and the mixture was heated to 70-8000 in 22 h to form the product PX.

P-XI was prepared by first forming an adduct of 2,4-toluene diisocyanate (26.8 g) and hydroxyethyl methacrylate (22 g) in 30 ml of methyl ethyl ketone with 0.02 g of butylated hydroxytoluene in the same procedure used to to form the third reaction product of preparation IX. This product was added over a period of 1 hour to the product of the second solution of P-VI (87.7 g as 80% solids in methyl ethyl ketone) and 0.02 g of butylated hydroxytoluene and heated to 65-70 ° C. Heating was continued for 7.5 hours at about 6700 ° C. 10 g of succinic anhydride and 0.4 g of lithium acetate were then added to the solution and the whole heating at 7 ° C a4 P-xz.

Preparation XII; A urethane oligomer (hereinafter P-XII) was prepared by the following procedure. A 1000 ml three-necked flask with adapter equipped with an overhead mechanical stirrer, thermometer, addition funnel and drying tube was charged with 180 g of a polypropylene oxide polyol having a molecular weight of 600 g. and 90 ml of methyl ethyl ketone. A solution of 34.8 g of 2,4-toluene diisocyanate in 30 g of methyl ethyl ketone was added with stirring at room temperature. The addition was completed after 80 minutes and stirring was continued at room temperature for 90 minutes. After the addition of 0.02 g of 2,6-di-t-butyl-4-methylphenol, the temperature was raised to 45 DEG-50 DEG C. at 15 DEG C., at which point isocyanate groups could no longer be detected by infrared analysis. .

To a 250 ml one-necked flask with a magnetic stirrer and drying tube was charged 95.7 g of 2,4-toluene diisocyanate. 78.9 2-hydroxyethyl methacrylate was added over a period of about 10 minutes while maintaining the temperature at less than 30 ° C with a cold water bath. After about 40 minutes total reaction time a white solid formed and 45 ml of methyl ethyl ketone was added. The solution solidified after standing overnight and was redissolved by heating to ee 4s ° c. The product of the reaction between the polyol and 2,4-toluene diisocyanate was heated to 67 ° C and the product of the reaction between 2-hydroxyethyl methacrylate and 214-toluene diisocyanate was added over a period of about 30 minutes. After 6 hours, 27 g of succinic anhydride and 1.05 g of lithium acetate were added. After about 28 hours of heating at 53 ° C-70 ° C, it was determined that the anhydride had completely reacted by infrared analysis. A solution was prepared (1% by weight) of 3.32 parts of pentaerythritol tetrachrylate, 1.87 parts of P-II, 0.17 parts of triethylamine, 0.34 parts of diphenyl iodhexafluoro phosphate, 0.17 parts of 4,4'-bis (dimethylamino) benzophenone (a photosensitizer for the iodine catalyst) and 91.62 parts of azeotrope n-propanol / water (71, 8% n-propanol and 28.2% water) . Small portions of this solution were prepared and 2.50 parts by weight of various organic polymeric binders were added to the solution. Aluminum sheets which had been annealed and anodized were coated with these solutions using a 14 wire wound rod and then dried with a heat gun. .

The coated aluminum was then exposed for 13 seconds in a vacuum arc for a carbon arc lamp with an output power of about 5000 W and at a distance of about 1 m through a 21-step step wedge and a gray filter with a density of 0.51.

Exposed sheets were developed by drying with a weak aqueous aqueous solution of 0.63% sodium metatics or 0.23% sodium (lower alkyl) naphthalene sulfonate. The binders used in the examples were: 1. PV, 2. poly (vinyl methyl ether), 3. poly (vinyl formal), prepared from a polyvinyl acetate starting material and with 85% of the acetate groups replaced by alcohol and formal groups (the polyvinyl acetate had a viscosity of about 12 cP at 25 ° C, as 86 g in 1000 ml of benzene) and _ 4. poly (vinyl butyral).

The following table shows the polymer that remains after exposure to a certain number of steps and development by means of the weak basic solution. 10 15 20 25 30 25 79os7ro9-9 i d '262 Example S t e g _ _1: -¿._s_1; _. veil. l 8 10 2 4 p 3 4 i's, _ 2 'The "Veil values" show the lowest exposure from 7 which photopolymer was retained on the sheet. The “fixed values” indicate the exposure level at which the density of the developed image can no longer be distinguished from the background and is assumed to be cured to the desired level.

. The number of steps in a row shows an increase of about 40% of the filtration strength. The higher the number of steps remaining after development, the higher the sensitivity of the exposed and developed composition.

EXAMPLE 5 The utility of the composition of the present invention in conventional newsprint printing operations is evaluated here. A solution was prepared from 17.2 g of pentaerythritol tetraacrylate, 13.5 g of P-II (70% by weight in methyl ethyl ketone), 17.6 g of polyvinyl formalin in a 6% by weight solution in the azeotrope, 295 g of azeotrope n-propanol / water, 4.3 g of 20% triethylamine, 3.7 g of red pigment (Pigment Red 48, C115865 in Color Index) in a composition with a weight ratio of 1: 2 to polyvinyl formal (as described above), 1.74 g of diphenyl- iodine hexafluorophosphate and 0.65 g of the photosensitizer 4,4'-bis (dimethylamino) benzophenone. This composition was coated on veined anodized aluminum using a press roll coater equipped with a gravure rubber rubber sleeve. The coating weight was about 1.72 g / m2. The coating was exposed in a vacuum rack with a carbon arc lamp for 40 seconds through a gray filter with a density of 0.5 and a newsprint negative. The coating was developed with the aqueous developing solution of Examples 1-4 and then rubberized with a subtraction plate. The resulting printing form was mounted on a high speed scroll press using direct lithographic techniques and produced 95,000 newspaper prints without degrading the image of the line original or halftone images.

EXAMPLE 6 A solution was prepared from 7.72 g of PV, 327.4 g of azeotrope n-propanol / water, 12.8 g of pentaerythritol tetraacrylate, 10.3 g of a 69% by weight solution of P-II in the azeotrope, 3.2 g of a 20% solution of triethylamine in the azeotrope, 15.7 g of Pigment Red 48 dispersed in PV and the azeotrope (4: 8: 88), 1.3 g of diphenyl iodhexafluorophosphate and 0.65 g of the benzophenone sensitizer in the previous examples. This solution was coated on veined anodized aluminum using a press roll coater equipped with a gravure rubber sleeve at a coating weight of about 1.72 g / m 2. The coatings were exposed from a pasted dummy with a laser imaging system using primarily the 351 and 364 nm lines from an argon ion laser (at 4 mJ / cm 2 exposure) and developed with the mild basic aqueous development solution of the previous examples and rubberized. with a commercial subtraction sheet rubber.

The printing molds were mounted on a roller offset press and generated high-quality prints.

EXAMPLE 7 A solution was prepared from 12.8 g of polyvinyl formal of a 6% by weight solution in azeotrope n-propanol / water, 1.28 g of pentaerythritol tetrachrylate, 1.42 g of P-III as a 50% by weight solution in ethyl acetate, 24 g of the the azeotropic solution, 0.28 g of Pigment Red 48 in polyvinyl formal (weight ratio 1: 2), 8 drops of a 20% solution of triethylamine in the azeotrope, 0.13 g of diphenyl iodhexafluorophosphate and 0.065 g of the benzophenone sensitizer from the previous examples.

This solution was coated on aged anodized aluminum using the AKI4 wire-wound rod. After exposure (from a carbon arc lamp with an output power of 5000 W lo _ 15 20 25 30 våozvoè-9, _, _ 28 »i l3 s through a gray filter with a density of 0.51) and development with the weak basic solution from the previous examples, a solid image was obtained in step 6 and an effluent was obtained in step 7. EXAMPLE 8 A solution was prepared from 1.54 g of PV, 2.56 g of pentaerythritol tetrachrylate, 2.6 g of P-II as a 70% by weight solution in methyl ethyl ketone, 0.64 g of triethylamine as a 20% by weight solution in the azeotrope, 4.7 g of a dispersion of Pigment Red 48 in PV and the azeotrope (4: 8: 88), 65.6 g of the azeotrope, 0.25 g of diphenyl iodhexafluorophosphate and 0.1 g of 4,4'-bis (dimethylamino) benzophenone. This solution was coated with an A144 wire-wound rod on a substrate comprising a polyethylene film having a topcoat of TiO2 and CaCO3 in a polyurethane binder. This coating was air dried with a heat gun and coated with a 10% solution of low molecular weight (see% hyalarylated polyvinyl acetate) poly (vinyl alcohol) with a small amount of inert surfactant as a coating aid. An á'lO wire wound rod was used to apply this solution.

The dried coating was exposed in a vacuum rack to a carbon arc lamp for 13 seconds through a gray filter with a density of 0.5, a halftone negative and a step wedge. The exposed coating was developed with an aqueous solution of 0.63% sodium metasilicate and 0.23% sodium (lower alkyl) naphthalene sulfonate. A strong red-violet image on a white background was obtained.

Fixed step 3 and blur step 5 were visible and sharp 3-97% points of at least one 10 dashed grid were obtained.

EXAMPLES 9-15 The following examples illustrate the necessity and interaction between the various components of the system of the present invention. The effect of poly (vinyl alcohol) - topcoats, commonly used in the art _ as an oxygen barrier; was also examined.

Solutions were prepared with different combinations of representative additives. P-V was used as binder, P ~ II as the carboxyl-containing radical polymerizable oligomer, pentaerythritol tetrachrylate as the radical polymerizable monomer, diphenyl iodhexafluorophosphate (as 0.04 parts by weight) as es / radical / nitrate. Û:> -_-_ \ _> ¿\ / m - c7 fl l5, N a // N "'p 0 czns cnacozn hereinafter referred to as CEBH (0,0l parts by weight) as a sensitizer and poly (vinyl alcohol) as a topcoat.

The solutions with the compositions listed in the table below were coated on veined and anodized aluminum to give dry coating weights of 1.06-1.61 g / m 2. When a top coat was present, the poly (vinyl alcohol) was applied with approximately the same coating weight as the base coat.

In the examples, the solutions were prepared from isopropanol or methanol-methylethyl ketone aqueous solutions. Triethylamine was added in all the examples in amounts equivalent to the acid in P-II. The dried samples were exposed through a 21-step step wedge for 2 seconds with a 16,000 foot normal tungsten source. The exposed samples were developed by drying with an aqueous solution of 0.35% sodium metasilicate and 0.25% sodium (lower alkyl) naphthalene sulfonate. 10 15 20 25 30 35 190s7o9> 97i 30 Ex - 7 _ _ nr P-V P-II Monomer Top layer Step ~ 9 0.3 0.0. 0.4 No e 1 10 a 0.3 0.4 o, o No 1 11 0.0 0.5 4_- 0.4 No _ 0 12 g 0.0 0.5 0.4 Isa 10 1: - : 0.3 0.2 _ 0.4 'No 9 _14 0.3 0.4 0.2 No 10-11 _ 15' 0.3 0.4 0.2 Yes 14 As can be seen from these results, The presence of any of the three constituents (binder, oligomer or monomer) of bad or unusable photopolymerizable compositions. When a top coat is applied to the composition without the binder (Example 12), the oxygen sensitivity of the system is reduced and it polymerizes well. Surprisingly, the systems having the three components of the present invention work well as the topcoat system (Examples 13 and 14) and when the systems of the present invention are combined with a topsheet, even better results are obtained - (Example 15). These results are surprising and highly sought after.

EXAMPLE 16 A solution was prepared from 4 parts of poly (m-dialyl phthalate), 2 parts of P-II, 4 parts of pentaerythritol tetrachrylate, 5 parts of methanol, 0.4 parts of diphenyl iodhexafluorophosphate, 0.1 part of CEBH, 0.4 parts of Phthalocyanine Blue GS and methyl ethyl ketone to 100 parts. This mixture was coated on aged and anodized aluminum to give a dry coating weight of about 1.34 g / m 2. This was coated with poly (vinyl alcohol) having approximately the same coating weight as the base coating. The coating was air dried and exposed and then developed as in Examples 9-15. The photopolymer remained through step 12.

EXAMPLE 17 The same procedure as in Example 16 was used except that 4 parts of tris-methacryloxyethyl isocyanurate 31 was used instead of the pentaerythritol tetraacrylate.

The photopolymer again remained through step 12.

EXAMPLES 18-21 A solution was prepared from 0.3 g of PV, 0.4 g of pentaerythritol tetrachrylate, 0.22 g of P-II, 0.04 g of diphenyl iodine-hexafluorophosphate, 0.02 g of CEBH, 1.28 g of methyl ethyl ketone 0.47 g of water, 7.36 g of isopropanol and 6 drops of a 20% by weight solution of triethylamine in n-propanol; The solution was coated with wire-wound rods on veined and anodized aluminum with coating weights of 0.95, 1.36 and 2.04 g / m2. Some of the coatings were coated with a 10% by weight solution of poly (vinyl alcohol) using an A18 'wire-wound rod. The coatings were exposed using a 488 nm argon laser and developed by drying with a pad and an aqueous solution of 0.35% sodium metasilicate and 0.25 sodium (lower alkyl) naphthalene sulfonate. The laser beam had to pass through a step wedge with 21 steps. The exposure values (in mJoule / cm2), s listed below are the exposures required to give a fixed step 6 for the different coating weights.

Coating s- Top- Expo- gain weight, g / m ëßiët nering 18 0.95 Yes 1.8 19 1.36, Yes E 1.8 20 1.36 No io-14 21 2.04 No 10 'As shown improves the top layer compositions, but the uncoated materials are still extremely fast and have high quality even when exposed to the presence of air.

EXAMPLES 22-32 Solutions were prepared as in Example 16 except that different photoinitiation systems were evaluated.

The exposure was made for a mercury vapor lamp with an output power of 500 W / 25 mm at a distance of about 34 cm through an interference filter with a maximum transmission at 366 nm and a step wedge with 21 steps. The table shows the relative sensitivity of the system to the residual photopolymer ex 22 23 _ 24 25 2s 27_ 28 29 30 31 32 with the development according to Example 16. - Approx. Absorption Phytoinitration system at 366 nm 4,4'-bis (dimethylamino) - 0,3 benzophenone 2-o-chlorophenyl-4,5-di- (methylmethiphenyl) imidazole dimer 2-o-chlorophenyl-4,5-diphenylimidazole dimer 2-mercaptobenzoxazole ~.

Same as Example 22 0.01 4,4'-bis (dimethylamino) - 0.1 benzophenone diphenyl iodhexafluorophosphate tetraphenylbenzidine, 0.2 diphenyliodhexafluorophosphate tetraphenylbenzidine - 0.1 diphenyliododhexafluorophosphate tetraphenylbenzidyl bisphylphenyl (2,2-diphylphenyl) triphenyl - 0.2 - (4-methoxylstyryl) -s-triazine 3-carboxymethyl-5 (3-ethyl-2,2 -2-benzothiazolinylidene) -2- (3-heptyl-4-oxo-2-thio- -5- (thiazolinylidene) -4- -thiazolidone diphenyl iodhexafluorophosphate chlorothioxanthone "0.2 diphenyl iodhexafluorophosphate ethyldimethoxyanthracene 0.02 diphenyl iodhexafluorophosphate JI 4,4'-bis (dimethylamino) - 0.1 benzophenone 2 'Relative 70 .3 3.3 4.8 13 6.6 13 '40 40 10 15 20 25 30 35 79os7o9 + 9.33 EXAMPLES 33-39 A stock solution was prepared by mixing 5.13 g of pentaerythritol tetrachrylate, 4.03 g of P-II , 25.5 g of a 10% by weight solution of polyvinylformal in the azeotropic solution of n-propanol and water, 119 g of methyl ethyl ketone and 1.5 g of a 20% by weight solution of triethylamide in azeotropenf To parts of 20 g v this solution was put different photoinitiation systems.

The photoinitiation systems and the amount of each are shown in the following table. The solutions were then coated on a veined anodized aluminum substrate with a 5414 wire wound rod and dried with a heat gun. The resulting coatings were exposed for 13 s to a carbon arc lamp through a step wedge with 2l steps and a filter with a density of 0.5. The exposed coatings were developed by drying with an aqueous solution of 0.63% by weight of sodium metasilicate and 0.23% by weight of sodium (lower alkyl) naphthalene sulfonate. The number of solid steps observed after rubberization and printing was recorded. As in previous examples, the higher the number of steps retained, the greater the sensitivity of the coating. I 7 1 Weight Fast walking Photoinitiation system 9 step 33 4,4'-bis (dimethylamino) benzophenone 0.035 0 34 4,4'-bis (dimethylamino) benzophenone 0.035 7 diphenyl iodhexafluorophosphate '0.070 35 7-diethylamino-4-methyl coumarin 0.035 36 7- diethylamino-¶-methylcoumarin 0.035 '4 diphenyl iodhexafluorophosphate 0.070 37 2,4-bis (trichloromethyl) -s- (4- (o7o2-methoxystyryl) -s-triazine 38 2,4-bis (trichloromethyl) -6- ( 4- 0.14 3-methoxystyryl) -s-triazine 39 4,4'-bis (dimethylamino) benzophenone 0.035 μl 2-o-chlorophenyl-4,5-di (m-methoxy-0,10 phenyl) -imidazole dimer 2 -o-chlorophenyl-4,5-diphenyl-0.10 imidazole dimer 2-mercaptobenzoxazole 0.07 None of these compositions had topcoats. 10 15 20 -_79o37o9 ~ 9 = 34.

EXAMPLES 40 'and 41 _ Two additional monomers were evaluated in the compositions of the present invention. Two solutions (A and B) were prepared with the following composition: P-II (64% in methyl ethyl ketone) ~ 3.12 polyvinyl formal (10% in n-propanol-7,6-water azeotrope) "," "PV (1.2.9% in n-propanol (62%), 4.18 isopropanol (10%, and water (28%) dispersion of Pigment Red_48 and 10.0 polyvinyl formal (10% in the above azeotrope) in 2 / l parts by weight. / pigment 4,4l-bis (dimethylamino) benzophenone 0.19 diphenyl iodhexafluorophosphate 0.37 triethylamine (20% by weight in the azeotrope), 0.96 n-propanol-water, azeotrope 70.0 To solution A was added 3.67 g of pentaerythritol tetrachrylate and To solution B was added 3.67 g of trisQ-crystalline isocyanurate. The solutions were then coated on veined and anodized aluminum using an Al-118 wire-wound rod and dried for 1 minute at 65 ° C. the plates were then exposed with a 2 kw diazo lamp in 2, 5 and 10 s of air.The exposed plates were developed by washing with an aqueous solution of 3% sodium metasilicate, 3% n-propanol, 0.3 3 sodium dodecyl diphenyl ether disulfonate and 0.3% of an alkyl naphthalene sulfonate. The number of fastening and veil steps that remained after development is given in the following table, Coating 2 s 5 s 10 s, fixed / veil fixed / veil fixed / veil A 4-5 5-7 6-8 B * 7-8 9-10 9 The usefulness of the compositions of the present invention in lower intensity exposure processes was investigated. The percentage weight composition of the compositions was as follows:% Solids Component solution A solution B pentaerythritol tetraacrylate '43.1' 32.3 P-11 I 23.7'l Pv _ s, 25_ 17.2 polyvinyl formal (10% in the azeotrope ) 15.2 '' 17.7 pigment dispersion (according to ex. 40), 3.09 2.8 triethylamine (20% in azeotrope) 2.15 1.6. diphenyl iodhexafluorophosphate 4.30 8 4,4'-bis (dimethylamino) benzophenone 2.14 2 Solution A was dried for 1 min at 82 ° C with a coating weight of 200 mg / 0.09 m2 heat gun at a coating weight of 170 mg / 0 , 09 m2.

. Solution B was dried with a -The substrate in both cases was grouted and anodized aluminum..A conventional microfilm enlarger was used-. and the plates were exposed to between 10 and 30 'mW / cm 2 irradiation with a mercury xenon lamp through a 21-step step wedge in contact with the plate. The exposure was made in air. The exposed plates were developed by washing with an aqueous solution of 5.25% metasilicate, 6.37% n-propanol, 8.25% glycerol and 0.075% alkylnaphthalene sulfonate. The results are given below.

Exposure time Step Plate s fixed / veil A '2 in 3-s 4' 4-6 67 5-6 8 5-7 .Be 2 5-7 4 6-8 6 6-8 10 '15 _ 20- zs 30 _35 19u37o9-9, 36 _ When identical shapes were printed (A in 3 s and B ils) -with line originals and halftones on an aluminum sheet, l0,000 high-quality prints were obtained without any image loss. EXAMPLE 44-so A standard solution was prepared with the following weight percentages of the constituents of n-propanol-water azeotrope: 'pentaerythritol tetrachrylate 43.2 Pv ~ 6.35' polyvinyl formal (10% in the azeotrope '15.1 Pigment Red 48 a 3.1 triethylamine 2.15 diphenyl iodhexafluorophosphate 4,4,4,4'-bis (dimethylamino) benzophenone -2,2 To 7 parts of this solution were added 23.5% by weight of oligomers P-II and P-VI P-XI The solutions were coated on veined and anodized aluminum using an A118 wire-wound rod and dried for 1 minute at 65 ° C.

The dry coatings were exposed to air through a 21-step step wedge with a mercury metal halide diazole lamp and developed by drying with the aqueous developing solution of Example 40. The results are shown in the following table. Example Oligomers .a 44 P-vx - 4-7 45, P-V11 I 4-1 46 P-VIII -, 3-6 41 P4xx 1 _4-s 48 P-11 _ 3-6 49 '- Px 4-5 so P-xx o-2 10 1s_ 20 25 30 79.337: 19- »9 37 The above examples show the effect of variation of the ratio between the acid groups and the molecular weight of the oligomer. The first two compositions (Examples 44 and 45) had acid group to molecular weight ratios of approximately 134000 and 1: 360O, respectively, and were more difficult to develop than the preferred ones and tended to retain the ink on the background. A stronger and more powerful developer could correct this tendency.

The oligomer of Example 50 had an acid to molecular weight ratio of about 1.75 ° C and was developed a little too lightly, removing much of the photoreacted material. However, all the compositions were useful and could be polymerized in air. Examples 46-49 worked extremely well and had a ratio between the number of acid groups and the molecular weight of between about 800 and 1: 3 and 1: Example 48 had a ratio of about 1,200. Compositions without some acid groups do not adhere well to the substrate. Development does not distinguish between exposed and unexposed areas with both removed without distinction. Compositions without ethylene unsaturation do not photoreact or bind to 1-.111 p1α-ethylene. in EXAMPLE 51 A solution was prepared similar to those of Examples 44-50 using P-XII instead of the oligomers in the above examples. Coatings were exposed and developed as in Examples 44-50. Only one slippage step and no fixed steps were obtained. Prolonged exposure resulted in more sustained steps. IN EXAMPLES 52-57 A solution was prepared for comparison of different binder materials. The solution comprised in parts by weight: d-19os1o9-9 ~ f 38 2 pentaerythritol tetrachynylate 41.3 P-II I - ', ~ - 22 .5-polyvinyl formal.?t- 9.95 Pggment.Rea 48 _ f. _ '2,94 triethylamine I' 2,05 diphenyl iodhexafluorophosphate -4,2 4,4'-bis (dimethylamine) benzophenone 2.1 selected binders 14.9 The selected binders were 52. Pv. 2 53. low molecular weight hydroxypropylcellulose 54. polyvinyl butyral (molecular weight 38,000 - 45_000) 55. polyamide (Elvamide () nylon resin from DuPont Co.) 56. polyvinyl formal a 57. no resin.

The solutions were coated on salt plates (clear crystals of sodium chloride), dried and the infrared spectrum was determined.

The coatings were exposed to air for irradiation of a 2 kW mercury metal halide diazole lamp at different times with different radiation intensities. Infrared spectrum was determined after exposure and the percentage of double bonds converted at exposure was calculated based on the absorption at 810 cm -1. The results are given below. . % double bonds Exemgel converted at 9 mW / cm 2 radiation sz '35 53 - 32 54 - 32 55 27 56 25 57 _ »15 EXAMPLES 58-69 I A solution was prepared for comparison between different binder materials. The solution comprised in parts by weight: 20 p of ether-phytol tetrachrylate 43.1 P-I:. 23.1 polyvinyl formal 15.0 Pigment Red 48 I 3.0 triethylamine 2.2 diphenyl iodhexafluorophosphate 4.4 4,4 Hbis (ethylethyl benzophenone 24, 2 selected polymeric binders 6.3 The selected binders were '' 58. P-ïv 59. polyvinylpyrrolidone 60; polyvinylformal 61. copolymer of vinyl chloride (81%) and vinyl acetate (19%) 62. polyvinyl acetate '_ 63. polyethylene oxide (molecular weight š 4,000,000) 64. polymethyl methacrylate (low molecular weight, intrinsic viscosity Q 0,2 65. low molecular weight polyolefin resin 66. linear saturated polyester resin 67. thermoplastic aromatic polyurethane 68. cellulose acetate butyrate V69.

The results of infrared analysis after coating of these compositions as in Examples 52-57 and exposure to 9 mW / cm 2 radiation are given below. I 30 35 "Double Binding Conversion% Exemgel 58 30 59 30 60 25 61 25 62 25 63 24 64 23 65 16 66 15 67 15 68 13 69 l5 In Examples 52-69_the exposure time was 10 s.

Claims (4)

1o_ 15 20 25 30 79: 137a9n-ter ** ”d” PATENTRRAV _ 1. Photopolymerizable composition, k ä n n e - t e c k n a d that it comprises 1.) 10 - 60% by weight of an organic film-forming polymer having a molecular weight of at least 6000, 2.) 10 - 60% by weight of a radical polymerizer carrier having at least one ethylenically unsaturated group and 3. .3) 0.1 to 12% by weight of a photoinitiator system capable of initiating radical polymerization upon absorption of electromagnetic radiation, and 4) 10 to 60% by weight of a photopolymerizable oligomer of the formula O (s-pain-eoë) -A) b wherein E is an ethylenically unsaturated, radical polymerizable '9fUPP: D is the residue of e; polyisocyanate with at least two of the isocyanate groups reacted to form -NHC groups 8 attached to E and R, R with at least a + b hydroxyl groups, which residue is formed by removing hydrogen from the hydroxyl groups, which polyol has an average molecular weight based on the number of 90 ~ 10,000, A is a carboxylic acid-containing group a is a number having an average value of 2-20 and b is a number that has an average value of 0.3-10. A photopolymerizable composition according to claim 1, characterized in that AE is selected from acryloyloxyalkoxy, methacryloyloxyalkoxy, vinylalkoxy and allyloxy groups, D is the residue of a diisocyanate, A is the choice: planar + ca2) mEou and -c6n4Sonl 0 m is an integer from 1-6. Photopolymerizable composition according to claim 1 or L, characterized in that E is selected from acryloyloxyalkoxy and methacryloyloxyalkoxy and that the radical-polynerizable monomer has 2-4 ethylenically unsaturated groups selected from acryloplay and methacryloxy. A photopolymerizable composition according to any one of claims 1 to 3, wherein the film-forming polymer is selected from polyvinyl acetals, polyvinyl alcohol, polyvinylpyrrolidone, polyamides, hydroxyalkylcellulose, polyvinyl acetate and copolymers of polyvinyl chloride and polyvinyl acetate. Photopolymerizable composition according to one or more of claims 1 to 4, characterized in that the oligomer is represented by the formula: O - O (ß-b-nla-a-nz-ßnl-ë-n3-ëoufb wherein E is an ethylenically unsaturated radical polymerizable group selected from acryloyloxyalkoxy and methacryloyloxyalkoxy, d 1 D is the residue of a diisocyanate having its two isocyanate groups reacted to form -NHC groups O-bonded to E and R1, R1 is the residue formed by the removal of active hydrogen atoms and hydroxyl groups from oligomeric Q-hydroxycarboxylic acids or the residue formed by removal gave active hydrogen atoms and hydroxyl groups from oligomeric diols, R2 is the residue of an aliphatic polyol of the formula R5 (OH) a + b after removal of a + b hydrogen atoms from hydroxyl groups and having a valence of a + b, or the remainder of an aliphatic polyol of the formula “5____s (HO) a + b_l RODOR (OH) a + b_l 2 2- after removal of ( a + b ~ l) hydrogen atoms from hydroxyl groups and R 5 is the residue of an aliphatic p olyol radical formed by removal of the O 2 radicals from the polyol and having 3-10 valencies substituted with OH groups, R 3 is the residue formed by removing two I -COH groups from a dicarboxylic acid, 11 is a number having an average value of 2-20 and b is a number having an average value of 0.3-10, the molecular weight of (R1 + àR2- + R1) b being 200 Photopolymerizable composition according to claim 1, characterized in that the oligomer is represented by the formula _ _ _ oo 'o' o 'o _' II 3 II 7 __ "6 ll 'I __ ¿acc-n -c -gyšn pewa-n -NHc04-cH2a-cocc = cr12_ / P _. | _. wherein R 3 is the residue formed by removal of two -COH groups from a dicarboxylic acid, II '0 - 4 is H or CH 3, R c is 2-5, p is a number with an average value of 2-7,7 q is a number having an average value of 0.344, R6 is the residue formed by the removal of two isocyanate groups from a diisoyanate and R7 is an organic polyol radical which is the residue of an organic polyol having at least 3 hydroxyl groups removed and having a molecular weight of so - 1o ooo. Photopolymerizable composition according to claim 1, characterized in that the oligomer has the formula *:; ..- «Hi '15 20 25 30 35 veoavue-9 43 'a I Oëßécuydoleg-Rïcon f lä Iznr o (cn2> dc eofa9 ° o. I 5 t ogcçcuàåaoë fi mm Nncoçcnz-èêocc-cza? n ~ f '- O 0_ Ru ~ wherein R3 is the residue formed by removing two -COH groups from a dicarboxylic acid, so 1: 4 is n or m6, R6 and R8 are independently residues formed by removal of two isocyanate groups from a diisocyanate, "a is 1-6, e is a number with an average value of 0.5-5, R9 which is the residue of a alkane polyol having h + 1 hydroxyl groups removed, which alkane polyol has a molecular weight of 100 - 10,000, f is an integer from 1-6 and h is an integer from 2-8. side is coated is an alkane polyol radical having a valence of h + 1, with a polymerizable composition comprising _1) 10 - 60% by weight of an organic film-forming polymer having a molecular weight of at least 6000, 2) 10 - 60% by weight of a row metal polymerizable monomer having at least one ethylenically unsaturated group and 0.1 to 0.1 to 12% by weight of a photoinitiator system capable of initiating radical polymerization after absorption of electromagnetic radiation, and 4.) 10 - 60% by weight of a photopolymerizable oligomer of the formula '10 -Dveosvu-9-Å' V 'da' 44. Wherein Z is an ethylenically unsaturated, radical polymerizable 9fUPP '' "». D is the remainder of a polyisodic cyanate having at least two of the isocyanate groups reacted to form -NBC groups II Is the residue of a polyol having at least a + b hydroxyl groups, which residue is formed by removal of hydrogen from the hydroxyl groups, which polyol has an average molecular weight based on the number of 90 - 10,000, A is a carboxylic acid-containing group, a is a number having an average value of 2-20 oeh b is a number having an average value of 0.3-10 9. Substrate according to claim 8, characterized in that it is of threaded and anodised aluminum and the composition is present in an amount of 0.3-9 g / m2.