DK162722B - Photopolymerizable recording substance - Google Patents

Description

in

DK 162722 B

The present invention relates to a photopolymerizable recording material for the production of printing plates and relief molds.

5 A number of photoinitiators of the most diverse structures are already known, for example. aromatic peptones such as acetophenone and benzophenone derivatives and benzilkate, e.g. benzyl dimethyl ketal (German Publication No. 2 003 132), benzoin ether (German Publication No. 1 694 149), thioxanthone (German Publication No. 2 003 132) and countless others. However, photopolymerizable masses cured with such initiator systems exhibit an undesirable yellowing which makes it impossible to use these systems on clear (or 15 white) surfaces or as coatings for color reproductions.

Another disadvantage is the often insufficient storage stability of the finished sensitized resin mixture which, despite storage in the dark, is barely durable for a few days.

The present invention is characterized in that the recording material as a photoinitiator contains acyl phosphine oxide compounds of the general formula 25

Rv.

\ 0 3 P-C-R (I)

/ I

2 ^ · ^ 0

30 R

wherein R 1 represents an alkyl group of 1-6 carbon atoms, a cycloalkyl group of 5 or 6 ring atoms, an optionally halogen, alkyl or alkoxy-substituted aryl group or the like.

DK 162722 B

2 shows an S- or N-containing five- or six-membered heterocyclic group; R 112 has the same meaning as R, wherein R and R may be the same or different, or may represent an alkoxy group, 1 2 aryloxy or ary 1 alkoxy group, or R and R are connected to each other to a ring; 3 R represents a tertiary alkyl group of 4-18 carbon atoms 10 or a tertiary cycloalkyl group of 5 or 6 ring carbon atoms or a cycloalkyl group, aryl group or a five- or six-membered heterocyclic group containing at least in both o-positions to the carbonyl group A and B are bonded, wherein A and B represent alkyl, alkoxy, alkoxyalkyl, alkylthio, cycloalkyl or aryl groups or halogen atoms, and A and B may be the same or different.

In particular, the invention provides such acylphosphine oxide compounds of the above general formula, wherein R represents at least 2 times the substituted phenyl, pyridyl, furyl or thienyl group at least at the two carbon atoms adjacent to the attachment site with the carbonyl group, carrying the substituents A and B, which may be the same or different, and denoting 1-6 carbon atom-containing alkyl, alkoxy or alkylthio groups, 5-7 carbon atom-containing cycloalkyl groups, phenyl groups or halogen, preferably chlorine or 3 bromine atoms, or R represents a o-naphthyl group substituted at least in the 2.8-30 position with A or B or at least in the 1,3 position represents a -naphthyl group substituted by A and B.

With regard to the general formula I, for the 35 acylphosphine oxide compounds in question, the following should be stated:

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3 R 1 may be a straight or branched alkyl group having 1-6 carbon atoms such as methyl, ethyl, i-propyl, n-propyl, n-butyl, amyl, n-hexyl, cyclopentyl, cyclohexyl-, aryl-, phenyl-, naphthyl-, halogen-substituted aryl-, such as mono-, dichlorophenyl-, alkyl-substituted pheyl-, methylphenyl-, ethylphenyl-, isopropylphenyl-, tert-butyl-, dimethylphenyl- , alkoxy-substituted aryl, such as methoxyphenyl, ethoxyphenyl, dimethoxyphenyl, S- or N-containing five or six-membered rings such as thiophenyl, pyridyl.

1 2

In addition to the meaning of R, R may represent an alkoxy group of 1-6 carbon atoms such as methoxy, ethoxy, i-propoxy, butoxy, ethyloxyethoxy, an aryloxy group such as phenoxy, ethylphenoxy, an aryl-substituted alkoxy group, as benzoyloxy-; 1 2 R may be connected with R to a ring such as e.g. an acylphosphonic acid o-phenylene ester.

3 R may represent an ethyl, i-propyl, n-butyl, i-butyl, tert-butyl, i-amyl, n-hexyl, heptyl, n-octyl, 2- ethylhexyl, i-nonyl, dimethylheptyl, lauryl, stearyl, cyclopropyl, cyclobutyl, cyclopentyl, 1-methylcyclopentyl, cyclohexyl, 1-methylcyclohexyl, norbornanedienyl, adamantyl -, dimethyloctyl, dimethylnonyl, dimethyldecyl, methylphenyl, dimethylphenyl, trimethylphenyl, tert.-butylphenyl, isopropylphenyl, methoxyphenyl, dimethoxyphenyl, i-propoxyphenyl, thiomethoxy, e- and t-naphthyl, thiophenyl, pyridyl, ω-acetoxy-oxyethyl or ε-carboxyethyl group, preferably a 2,6-dimethylphenyl, 2,6-dimethoxyphenyl, 2,6-dichlorophenyl, 2,6-dibromophenyl-, 2-chloro-6-methoxy-phenyl-, 2-chloro-6-methylthio-phenyl-, 2,4,6-trimethylphenyl-, 2,4, -35-6-trimethoxyphenyl-, 2 , 3,4,6-tetramethylphenyl-, 2,6-dimethyl-4-tert.-butylphenyl-, 1,3-dimethoxynaphthalene-2-, 1,3-dichloronaphthalene-2-, 2,8-dimethoxynaphthalene- L,

DK 162722B

4 2.4.6-trimethylpyridine-3-, 2,4-dimethox7-furan-3 or a 2,4,5-trimethylthiophene-3 group.

1 2 R and R may further contain C-C double bonds 5 which enable the photoinitiator to be polymerized in the binder.

Particularly preferred are aryl phenylphosphinic acid residues or aryl phenylphosphine oxide whose aryl group is each substituted at each 10-position with the alkyl, alkox7, halo gene, alkyl thio groups or mixtures thereof, e.g.

2,6-dimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethyl benzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl phenylphosphine acid ester, 2,6-dichlorobenzoyl or 2,6-dimethoxylbenzoyl diphenylphosphine oxide.

The preparation of such compounds occurs by reaction of sTrehaloids of formula 20 0 3 1 R -CX wherein X - Cl, Br, with phosphines of formula R1 25 x 4 4 P-OR R = straight or branched 2 / C1-C alk7l-, or

Rz C7Cloalk7l with 5 or 6 carbon atoms. 1 35

The reaction may be carried out in a solvent, e.g. a hydrocarbon or a hydrocarbon mixture, such as petroleum ether, toluene, c7clohexane, an ether, other usual inert organic solvents or also without

DK 162722 B

solvent at temperatures between -30 ° C and +130 ° C, preferably at 10-100 ° C. The product may crystallize directly from the solvent, or be left after evaporation thereof or distilled in vacuo.

5

The preparation of the acid halide 0 3 «

R c CX

10 12 4 and of the substituted phosphine RR POR occur according to methods well known to those skilled in the art (e.g., Weygand-Hilgetag, Organisch-Chemischche Experimentierkunst, 4th ed., Pp. 246-256, Publishers' JA Barth, Leipzig 1970 and K. Kasse in Houben-Weyl, 15

Volume 12/1, pp. 208-209, Publisher G. Thieme, Stuttgart).

The process for the preparation of the compounds of the invention can e.g. is described as follows: 20 Λ u ___ 0CH- _ J! ® <j. ♦ r§r «- * 25 '3 CK, J * - ί ° Γ 5 35 6

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or 10 CH, t ° r for 15 or 20 P- p ^ 0 0 <^ ν, · - <2> T # * ^

Cl 1; CE3 ° Cl 25 or 30. OCK, —fr Jf> · · * full · W3C- V. and 3 7

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Suitable phosphines are e.g. methyl-dimethoxyphosphin, butyl dimethoxyphosphin, phenyldimethoxyphosphin, tolyl-dimethoxyphosphin, phenyldiethoxyphosphin, tolyldiethoxy-phosphine phenyldiisopropoxyphosphin, tolyldiisopropoxy 5-phosphine phenyldibutoxyphosphin, toluyldibutoxyphosphin or dimethylmethoxyphosphin, dibutylmethoxyphosphin, diphenylmethoxyphosphin, diphenylethoxyphosphin, diphenyl nylpropoxyphosphin, diphenylisopropoxyphosphin, diphenyl-butoxyphosphin or similar starting materials leading to the subject compounds.

As acid halides, chlorides and bromides are suitable, especially preferred are the acid chlorides.

Examples of the compounds of the present invention are the following: 20 25 1 35 8

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Table 1: Examples of the compounds of the invention (Ph = phenyl)

Compound Mp. Kp. Yield Ar.aly = s '' 5 (C °) (C °) c H? -. ch3 o a - CH - C-C—- 104 / 0.3 m S5 ί ber. 60.0 7.03 12.9 J ca c ^ cch-. fun.59.8 £, 5 12, to 10 ciil 2Ν £ 3Ν? Γ?! 1 - 154 / 1.2 = s 65 ί "δΊ.Ο» 7.23 11.03 CH2 o vvi £ 3 ·. · · 63.3 8.1 · 11.0 ·

Cf O / ¾ · 101 - 70 ί 65.5S 5, c7 11.31 é == ¾ '' .. £ 5.7 '5.6 11.0 15 = ¾ O? H · 10-5 - 73? "75.00 5.31 9.59 o" *? H - '75.3 5.3 =, 3 CH.

CH. o Ta 20 107 - 'BH S. !. 75.00 5.31 =, = 9 o a ·> 74.7 5, L 5.5 ch. ίογ ^ Ζ · 135 - 8 * s It'T ff: f O? "n '.it 7z, 0 s» 5 * »7 C ^ 25 ca3 ch3 o o

Kl2? -CH2 5Vc-? A2 - 205 - 35; 71.91 t, 40 11.61

ό O 1 '71, s 4.3 11, C

30 ''.

C? A, 124 - 81 ί * '71.33 6, = 4 10,; 4

Chf '' cHj C in '71.0 5.5 11.0 -, .. / = ¾ C "3'cf ^ - 120 / 0.5 = 60 ί" 62.68 7.24 11.57 CH, CH, 0 rh '»63.0 8.0 11.4 35 9

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Table 1: Examples of the compounds of the invention (Ph = phenyl)

Compound Mp. Kp. Yield, r \ * r \ λ * »2ιlysse (c °) (c °) 5 o ri

ch. cl, cLj c -? ^ - - so i ber.73 »52 7 * 2? °> cS

"<pr.5 15 lun.«. '»· * ··« ra3 ^ 3 0 SS, 0 ri - SO; *' 66, zs =,: i 9.01 JO SS- O ri "= 5, S ό, Ι 3.5 c: -:, o c-chcc: - :,) 2 'VS ^ - 5: ° / 0.3 eo ί 1' 52, a3 S, 22 15, C5 andf '' 'ch - o ^ ch, "52.1 s, i ia, s ✓ ^ * f7 \ 15 W r / rh (c \ ——- 155 - 65 ί> t 7", 52 *, 73 3.71 '-' 11 77 »7 11,3 *» so cc2 = 5 lC2 ° / 0.05 = 3 or δ “53, 5, Si 13.71 O ^ CH-» '53, 9 5.7 13.5 20 c ; r. o? i 20 25; U 73, £ 2 7.05 e, c; 0? h · u 73,3 7; 1 9,5

ISLAND

CH- CH_ c? S - SO i, f 73.63 7.69 9, CS

'V *' ^ "73.9 8.1 a s 3 2 / N.

CH, CH- O? I 25 3 έ- 3 1 35

DK 162722B

10

The compounds of this invention exhibit a structure which has very good reactivity as photoinitiators for photopolymer in visible monomers having at least one C-C polyvalent bond and mixtures thereof and with each other and with 5 known additives. The present acylphosphine oxide compounds are particularly well suited as photoinitiators in photopolymerizable masses for coatings and varnishes as well as for reproduction materials. As far as yellowing of the lacquers or coatings thus prepared, they are far superior to the known photoinitiators (e.g. benzildimethyl ketal).

For this purpose, acylphenylphosphinic esters or acyldiphenylphosphine oxides are preferred if acyl groups are derived from a secondary or tertiary substituted aliphatic carboxylic acid such as pivalic acid, 1-methylcyclohexanecarboxylic acid, norbornene carboxylic acid, with 9-13 carbon atoms), 2-ethylhexane carboxylic acid, or of a substituted aromatic carboxylic acid such as p-methylbenzoic acid, o-methylbenzoic acid, 2,4-dimethylbenzoic acid, p-tert-butylbenzoic acid, 2,4,5-trimethylbenzoic acid, p-methoxybenzoic acid or p-thiome-methylbenzoic acid. 1 2 3 4 5 6 7 8 9 10 11

Especially the preferred o-substituted aroyldiphenylphosphine oxides or aroylphenylphosphinic ester possess a very good storage stability with extremely high 4 reactivity in photopolymerizable monomers. This applies 5 above all to the most widely used resins based on 6 styrene-containing unsaturated polyesters and to the styrene-free 7 acrylic acid esters. With the aforementioned initiators, 8 even those with white pigmented varnish cure without yellowing, 9 but also colored pigmented resins can be processed.

10

With regard to these properties, they outperform the previously known 11 photo initiators such as e.g. benzildimethyl ketal or α-hydroxyisobutyrophenone.

DK 162722 B

11

Further, it has surprisingly been found that these advantages remain or can be enhanced when combining the preferred aroyl diphenylphosphine oxides with known photoinitiators.

5

Particularly effective synergistic mixtures are obtained by combinations with known photoinitiators based on aromatic ketones, especially benzyl dimethyl ketal, α-hydroxy-isobutyrophenone, diethoxyacetophenone, benzophenone and 2-10 methylthioxanthol, 2-isopropyldioxanthone, and 2-chloro-thioxanthol. To this end, by the addition of tertiary amines such as methyldiethanolamine, their well known promoting effect is further utilized. By combining the said initiators with e.g. benzyl dimethyl ketal has succeeded in producing surprisingly effective, highly storage-stable, amine-free, photopolymerizable masses which may also be pigmented.

As the photopolymerizable monomers, the usual compounds and substances with polymerizable C-C double bonds which are activated by e.g. aryl, carbonyl, amino, amide, amido, ester, carboxy or cyanide groups, by halogen atoms or C-C double or C-C triple bonds. Mention may be made, for example. vinyl ether and vinyl ester, styrene, vinyl toluene, acrylic acid and methacrylic acid, and their esters with mono- and polyhydric alcohols, their nitriles or amides, maleic and fumar esters, and N-vinylpyrrolidone, N-vinylcaprolactamer, N-vinylcarbazole and allyl esters.

30

As polymerizable high molecular weight compounds, e.g. The following are suitable: unsaturated polyesters prepared from ', S-unsaturated drearboxylic acids such as maleic acid, fumaric acid or itaconic acid optionally in admixture with unsaturated or aromatic dicarboxylic acids such as adipic acid, phthalic acid, tetrahydrophthalic acid or terephthalic acid, by reaction with alkanediol,

DK 162722B

12 diol, neopentyl glycol or oxalkylated bisphenol A; epoxy acrylates, prepared from acrylic or methacrylic acid and aromatic or aliphatic diglycidyl ethers and urethane acrylates (eg, made from hydroxyalkyl acrylates and polyisocyanates), and polyester acrylates (eg made from hydroxy group-containing unsaturated polyesters) and acrylic or methacrylic acid).

Optionally, the photopolymerizable coating agents, lacquers and inks may also be present or used as aqueous dispersions.

The photopolymerizable compounds, whose composition for each application can be calculated by those skilled in the art, may be known in the known manner with saturated and / or unsaturated polymers as well as additional additives as inhibitors of the thermal polymerization, paraffins, pigments, dyes, peroxides, reaction aids, fillers, feeders and glass fibers as well as 20 stabilizers for thermal or photochemical degradation.

Such mixtures are known to those skilled in the art and the amount of addition depends on the individual application.

25

The compounds of the present invention are usually used for said purpose at a concentration of from 0.001 to 20%, especially from 0.01 to 15%, preferably from 0.1 to 5%, based on the photopolymerizable mass used. They may optionally be combined with accelerators which inhibit the influence of the air oxygen on the photopolymerization.

Such accelerators or synergists are e.g. secondary and / or tertiary amines such as methyl diethanolamine, dimethylethanolamine, triethylamine, triethanolamine, p-dimethylaminobenzoic acid ethyl ester, benzyldimethylamine, dimethylaminoethyl acrylate, N-phenylglycine, N-methyl-N-phe-13

DK 162722 B

nylglycine and analogs, which are known in the art. To accelerate the cure, additional aliphatic and aromatic halides can be used such as e.g. 2-chloromethylnaphthalene, 1-chloro-2-chloromethyl-naphthalene, and radical formers such as peroxides and azo compounds.

As radiation sources for the polymerization of such mixtures, such light is used, the light of which preferably lies in the absorption range of the compounds of the present invention, ie. between 230 and 450 nm. Particularly suitable are mercury low-pressure jets, medium pressures and high-pressure jets, as well as (superactinic) fluorescent tubes or pulse jets. The lamps mentioned may be doped.

15

The present photoinitiators are also particularly suitable for photopolymerization of reproduction materials, particularly for the production of printing plates and embossing molds, and consist predominantly of a photoinitiator-containing mixture of a) at least one monomer with at least one photopolymerizable olefinically unsaturated double bond, and b) at least one organic polymeric binder.

25

It is possible with the present photoinitiators to achieve a significantly faster cure of photopolymeric reproduction systems than with the prior art photoinitiators, and at the same time improve the relief structure of the 30 photopolymer relief forms.

Of the above-mentioned acylphosphine oxide compounds, these photopolymerizable reproduction materials are particularly suitable for the formula (I)

DK 162722B

R1

\ O

P - C - R 2 / I!

5 R 2 O

In which R and R represent the groups described above, 3 and R represent a tertiary alkyl group of 4-18 carbon atoms or a tertiary cycloalkyl group of 5 or 6 ring carbon atoms, or a cycloalkyl group, aryl group, or a six-membered heterocyclic group containing at least in both ortho positions to the carbonyl group the substituents A and B are bonded, wherein A and B represent alkyl, alkoxy, alkoxyalkyl, alkylthio, cycloalkyl or aryl groups or halogen atoms, and A and B may be the same or different.

20

The term "in both ortho positions of the carbonyl group contains substituents A and B" is understood to mean that substituents A and B are bonded to both of the ring carbon atoms which can carry substituents adjacent to the attachment site with the carbonyl group.

This means that the α-naphthyl group is at least in the 2,8-position and the α-naphthyl group at least in the 1,3-position containing the substituents A and B. At the cyclohexyl group, substituents A and B are at the 2,6 position, at the cyclopentyl group at the 2.5 position. Such acylphosphine-3

oxide compounds containing R bonded can, e.g. is illustrated by structural formulas II-VII

35

DK 162722 B

15 hV-O-CO- / h> (II); r1r2-? o-co- / · V (III) 'λ7 r7

B B

A 'In 10 R ^ 2-? 0-C0- / ~~ \ (IV) rV-po-co - /' ^, t (V)

* B

'- 15' A Λ R ^ -Po-co-rf ^ V ^ S ') - \ I II J (VI) R “K -PO-CO- / N, s, 0 (VII)

* / I

20 X

optionally X represents additional substituents in cycloalkyl, phenyl, naphthyl or heterocyclic groups having the meaning of A or B.

However, in the particularly suitable acylphosphine oxide compounds for photopolymerizable masses, 3R may also denote a tertiary alkyl or cycloalkyl group (each time having a tertiary C atom adjacent to the carbonyl group) such as e.g. tert-butyl, 1,1-dimethylheptyl, 1-methylcyclohexyl or 1-methylcyclopentyl. Particularly suitable for photopolymerizable reproduction masses are phosphine oxide compounds of formula I wherein R 1 is aryl of 6 to 12 carbon atoms, such as e.g. naphthyl, toluyl 16 2

DK 162722 B

and especially phenyl, and R is C ^-C ^ alkoxy as methoxy or ethoxy and especially aryl having 6-12 carbon atoms, preferably phenyl. Surprisingly high efficiencies with simultaneous high stability are photopolymerizable reproductive materials with acylphosphine oxide compounds of formula I, 3 whose acyl group -CO-R is derived from a tertiary aliphatic or cycloaliphatic carboxylic acid or from at least one substituted at the 2.6 position (with A and B). Particularly suitable acyl groups of this type are the 2,2-dimethyl-C ^-10 C 10-alkanoyl, 2-methyl-2-ethyl-Cg-alkanoyl groups and the benzoyl group, as in the 2,6-, 2,3,6- , 2,4,6 or 2.3.5.6 position carries the substituents A and B, especially the C 1 -C 2 alkyl groups, C 1 -C 2 alkoxy groups or halogen atoms.

15

The subject reproduction materials may contain the phosphine oxide compounds of formula I as the sole photoinitiators, usually in an amount of from 0.005 to 10 and especially in an amount of 0.005-5% by weight based on the entire amount of the photopolymerizable reproduction material, however. the phosphine oxide compounds also, as indicated above, are used in combination with well-known photoinitiators and / or with tert-amines in the photopolymerizable reproduction materials.

25

For this purpose, the total concentration of initiator system (photoinitiators plus amine) is between 0.05 and 15% by weight based on the entire amount of the photopolymerizable reproduction material, the amine proportion being preferably at least equal to half the total tiatorindhold.

For the mixture of (a) and (b) which form the basis of the subject matter of reproduction, as low molecular weight compounds having at least one photopolymerizable olefinically unsaturated double bond, such monomers which are well known to such masses are suitable if they form the carrier.

DK 162722B

equal mixtures with the polymeric binders selected in each case and having a boiling point above 100 ° C at atmospheric pressure. Generally, they have a molecular weight below 2000 and especially below 1000. Preferably, monomers having two or more olefinically unsaturated photopolymerizable double bonds alone or in mixtures with monomers having only one olefinically unsaturated photopolymerizable double bond, the proportion of monomers having only one double bond in general only amounts to approx. 5-50 and 10 preferably 5-30% by weight of the total monomer amount. The nature of the monomers used extends greatly to the nature of the co-polymeric binder used. Thus, mixtures with unsaturated polyester resins are especially allyl compounds containing two or more double bonds, e.g. maleic acid dialkyl ester, allyl acrylate, diallyl phthalate, trimelleic acid di- and triallyl ester or ethylene glycol bisallyl carbonate as well as di- and polyacrylates and methacrylates suitable for preparation by esterification of diols or polyols with acrylic acid or methacrylic acid. di- and tri- (meth) acrylates of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol having a molecular weight up to approx. 500, 1,2-propanediol, 1,3-propanediol, neopentylglycol (2,2-dimethylpropanediol), 1,4-butanediol, 1,1,1-25 trimethylolpropane, glycerol or pentaerythritis; further monoacrylates and monomethacrylates of such diols and polyols as e.g. ethylene glycol or di-, tri- or tetraethylene glycol monoacrylate, monomers having two or more olefinic unsaturated bonds containing ureas and / or amide groups such as the aliphatic diols of the aforementioned species, organic diisocyanates and hydroxyalkyl (meth) acrylates prepared low molecular weight compounds. Mention should also be made of acrylic acid, methacrylic acid and derivatives thereof such as e.g. (meth) acrylamide, N-hydroxymethyl (meth) acrylamide or (meth) acrylates of mono alcohols having 1-6 carbon atoms. Mixtures of allyl monomers with di- or polyacrylates are particularly suitable. chooses

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18, mixtures of polyamide as polymeric binder are provided, so that the monomeric species mentioned are suitable in addition to the di- and polyacrylates, especially those which, in addition to the double bonds, also contain amine and / or urethane groups 5 such as e.g. derivatives of acrylamides e.g. reaction products of 2 moles of N-hydroxymethyl (meth) acrylamide with 1 mole of an aliphatic diol such as e.g. ethylene glycol, xylylene bisacrylamide or alkylene bisacrylamide having 1-8 carbons atoms in the alkyl group. For the preparation of reproductive materials which can be developed with aqueous alkaline solution e.g. for the production of printing plates with polyvinyl alcohol, polyvinyl alcohol alkoxylation products or polyvinylpyrrolidone as polymeric binder particularly suitable water-soluble monomers such as e.g. hydroxyethyl (meth) acrylate or mono and di (meth) acrylates of polyethylene glycols having a molecular weight of about 200 to 500. For combination with elastomeric diene polymers as binder e.g. with polystyrene-polyisoprene-polystyrene three-block copolymers, polystyrene-polybutadiene two-block polymer or polystyrene-polyisoprene two-block copolymers are particularly suitable polyacrylates or methacrylates of polyols and especially glycols having at least 4 carbon atoms.

As organic polymeric binders b) for the mixture of the photopolymerizable reproduction materials and especially for the production of printing plates and embossing molds, the polymers known for this purpose come into play, in addition to being generally tolerable with the low molecular weight compounds a) and - for It will be appreciated by those of ordinary skill in the art to be soluble in a suitable developing solvent or dispersible herein to allow the unlabeled and non-crosslinked portions of the layer of the photopolymerizable reproduction material to be washed out. Suitable saturated or unsaturated binders include linear polyamides and especially alcohol-soluble copolyamides as described in French patent application 19.

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No. 1,520,856, cellulose derivatives, especially aqueous / alkaline leachable cellulose derivatives, vinyl alcohol polymers and polymers and copolymers of vinyl esters of aliphatic monocarboxylic acids of 1-4 carbon atoms such as unsaturated polyester resins, such as e.g. disclosed in German publication specification No. 2 040 390. Of the linear or branched polyesters of linear or branched kind produced by the reaction of unsaturated and possibly unsaturated di- and possibly fluorobasic carboxylic acids with di- and optionally polyalcohols, are particularly preferred. an acid number between 75 and 160 as they lead to an excellent dispersibility and solubility of the materials 15 in alkaline / aqueous developer solvents. With regard to the composition and preparation of unsaturated polyester resins, reference should be made to the available literature e.g. Η. V. Boenig; Unsaturated Polyesters, Structure and Properties, Amsterdam 1964.

20

The reproduction material at issue consists predominantly ie. more than 50 and preferably from 70 to 100% by weight of the photoinitiator-containing mixture consisting of a) and b). The content of this mixture of the polymeric binder b) is usually from 45 to 90 and especially from 45 to 65% by weight based on the sum of the amount of the polymer b) and the photopolymerizable low molecular weight compounds a). 1 2 3 4 5 6

It is often advantageous to add the photopolymeriser 2 bare materials to the usual amount of known inhibitors of thermal polymerization such as e.g. hydroquinone, p-methoxyphenone, m-dinitrobenzene, p-quinone, methylene blue, ε-naphthol, N-nitrosamines such as N-nitrosodi-6-phenylamine, phenothiazine, phosphoric acid ester as the tri-phenylphosphite or the salts, and especially alkali and the aluminum salts of N-nitroso-cyclohexyl-hydroxylamine.

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20

The materials may also contain additional additives such as plasticizers, saturated low molecular weight compounds with amide groups, waxes, etc.

Further processing of the photopolymerizable reproduction materials e.g. for photopolymeric printing plates, which exhibit, in layer form, the reproduction material as a relief shaped layer, can be made in known manner and depend on the nature of the mixture of a) plus b) and whether the mass is liquid or solid. Reprocessing of reproduction materials (for example, for relief molds) is done in a known manner by car-led lighting with actinic light. After the imaging illumination, for the manufacture of relief molds or photoresists, the unlit portions of the layer of the reproductive material are removed mechanically or per se by a suitable developer solvent, and the resulting molds, e.g. relief molds are in many cases suitably dried at full illumination.

20

A particular advantage is that with the subject matter of the reproduction in question it is often possible, even to relinquish a pre-illumination before the image illumination of the layers of the photopolymerizable reproduction materials, and to work with satisfactory illumination times. An unexpected great advantage is further that, as mentioned in Example 14, the layers of the subject reproduction materials, in the processing for relief printing forms, provide an improved relief structure, e.g. at 30 printing leads to a clearly improved reproduction of the negative print.

The parts and percentages mentioned in the following examples are, unless otherwise indicated, in parts by weight and by weight. Volume parts relate to parts like liters per kilogram.

EXAMPLE 1

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To a mixture of 1350 parts by volume petroleum ether (boiling range 40-70 ° C), 180 parts by volume N, N-diethylaniline and 67 parts by volume of methanol is added with stirring at 0 ° C 225 parts of diphenyl chlorophosphine dissolved in 220 volumes of petroleum ether. The mixture is then stirred for 2 hours at room temperature. After cooling to approx. +5 ° C is extracted with the separated amine hydrochloride, 10 and the filtrate is then distilled at 10-20 torr to remove all light boiling material. Subsequently, the diphenylmethoxyphosphine is fractionated at 0.1-1 torr. B.p. g 120-124 ° C. Yield: 175 parts (80% based on diphenyl chlorophosphine).

In a flask of stirring, reflux and drip funnel, 638 parts of methoxydiphenylphosphine are slowly added at 54 DEG to 557.5 to 547.5 parts of 2,4,6-trimethylbenzoyl chloride.

The mixture is further stirred for 4-5 hours at 50 ° C, after which the 20 flask content is dissolved at 30 ° C in ether and petroleum ether is added to incipient cloudiness. On cooling, 910 parts (87% of theory) crystallize 2,4,6-trimethylbenzoyl diphenylphosphine oxide, m.p. 89-92 ° C, as pale yellow crystals.

EXAMPLE 2 In an apparatus as in Example 1, 20 parts of 2,6-dimethoxybenzoyl chloride are slurried in 20 parts by volume of toluene, and to this mixture, 21.6 parts of dimethoxydiphenylphosphine are added dropwise with stirring at 50-55 ° C. Then, stir for 3 hours at 50 ° C and then recrystallize directly with toluene. You get 32 parts of yellow crystals with m.p.

124-126 ° C.

EXAMPLE 3 22

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In an apparatus as in Example 1, 91 parts of 2,4,6-trimethylbenzoyl chloride are placed. To this, 83 parts of triethyl phosphite are added at 60 ° C for 5 minutes and then stirred at 80 ° C for another 8 hours. The flask contents are distilled at a reduced pressure of 0.4 mm and the fraction at 120-122 ° C / 0.4 mm is captured. 51 parts of 2,4,6-trimethylbenzoylphosphonic acid diethyl ester (36% of theory 10) are obtained as a pale yellow liquid.

To a mixture of 1000 parts by volume toluene, 421 parts by volume Ν, Ν-diethylaniline and 100 parts by volume of methanol is added at 0 ° C 214 parts of phenyldichlorophosphine.

Thereafter, stir for an additional 1 hour at room temperature, the precipitate of amine hydrochloride is suctioned and fractionated. The dimethoxyphenylphosphine is distilled at 46-50 ° C / 0.2-0.3 mm. Yield: 190 parts (93% of theoretical yield).

20

To 182.5 parts of 2,4,6-trimethylbenzoyl chloride, 170 parts of dimethoxyphenylphosphine are dropped at 50 ° C. The mixture is kept for an additional 5 hours at 50 ° C, then the slightly yellowish oil is dissolved at 70-80 ° C in cyclohexane, and the product is crystallized after cooling to 5 ° C. To obtain slightly yellowish crystals, mp 51 -52 ° C; yield: 81% of theory.

Additional compounds prepared analogously to Examples 1-4 are shown in Table 2.

35

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DK 162722 B

A 65% methanolic solution of a mixture of 60% of a copolyamide of adipic acid, hexamethylene diamine, 4,4, diaminodicyclohexylmethane and e-caprolactam, 25% of the diethyl ether of 1 mole ethylene glycol and 2 moles is prepared. N-hydroxymethyl acrylamide, 13.2% benzenesulfonamide and 1.8% 2,4,6-trimethylbenzoyl diphenylphosphine oxide as well as 0.2% of the aluminum salt of N-nitrosocyclohexylhydroxylamine and 0.01% of a black dye (Color-Index No. 12,195 ). The solution is poured into layers on a steel plate provided with an adhesive lacquer so that after drying at approx. At 70 ° C, a layer of the photopolymerizable reproduction materials having a layer thickness of 680 µm appears. The resulting photopolymer printing plate is thus illustrated, as indicated in the text, through a paper, after which the unlit layers are washed with an alcohol-water mixture.

The plate requires a silent reproduction of a 3% igre toner value with a raster line width of 60 lines per second.

20 cm a minimum illumination time of 4 minutes when lighting is done with high actinic fluorescent lamps at a distance of 5 cm.

Example 6 Proceed as in Example 5 but use only 11.4% benzenesulfonamide and an additional 1.8% methyldiethanolamine. The minimum illumination time is only 3 minutes.

EXAMPLE 7 30

Proceed as in Example 5, however, as a phos-phine oxide compound, 1.8% 2,6-dimethoxybenzoylphenylphosphine oxide is used as a photoinitiator. The minimum illumination time is 4.5 minutes.

EXAMPLE 8 25

DK 162722 B

Proceed as in Example 6, however, 1.8% 2,6-dimethoxybenzoyl diphenylphosphine oxide is used as the initiator.

5 The minimum illumination time is only 2.5 minutes.

EXAMPLE 9

Proceed as in Example 6, however 1.8% "Versa-10" diphenylphosphine oxide (2,2-dimethyloctanecarbonylphenylphosphine oxide) is used as the initiator. The minimum illumination time is 3.5 minutes.

Comparative Experiment A 15

Proceed as in Example 5, however, as a photoinitiator 1.8% benzyl dimethyl ketal is used. Otherwise under the same conditions, the minimum illumination time here is 5 minutes.

Thus, the subject reproduction materials in comparison have a 25-100% elevated reactivity.

EXAMPLE 10

However, as in Example 5. Addition of dye 25 is omitted and instead of the aluminum salt, the potassium salt of N-nitrosocyclohexylhydroxylamine is added. The layer of photopolymerizable reproduction material produced has a dry layer thickness of 500 µm. The plates require perfect formation of a 3% grid tone value with a grid line width of 34 lines per second. cm, such as e.g. is often used for printing newspapers, a minimum illumination time of 50 seconds if illumination is made with a commercially available iron-doped mercury high-pressure lamp at a distance of 60 cm with an electric power consumption of the UV burner of 3000 Watts / hour. The further work up of the plate is thus done as described in Example 5.

EXAMPLE 11 26

DK 162722 B

As in Example 10, only 11.4% of benzenesulfonamide is used. In addition, the mass contains 1.8% methyldiethanolamine. The minimum illumination time is only 35 seconds.

EXAMPLE 12 10 Proceed as in Example 10, however 11.4% benzenesulfonamide and an additional 0.9% methyldiethanolamine and 0.9% benzild dimethyl ketal are used. Further, instead of 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 1.8% 2,6-dimethoxybenzoyl diphenylphosphine oxide is used. The minimum illumination time here is also 35 seconds.

Comparative Experiment B

Proceed as in Example 10, however, as a photoinitiator 1.8% benzyl dimethyl ketal is used. The minimum illumination time is 55 seconds under the specified conditions.

EXAMPLE 13 To 650 parts of an unsaturated polyester consisting of fumaric acid, trimellithic anhydride and triethylene glycol with an acid number of 140, 400 parts of a mixture of equal parts tetraethylene glycol dimethacrylate and diallyl phthalate, 2 parts hydroquinone and 7 parts 2,4,6-trimethylbenzo are mixed. -30 nylphosphine oxide. The liquid reproduction material thus prepared is added to 110 ppm N-nitrosodiphenylamine.

In a manner known per se, relief printing molds are made from the reproduction material. To this end, the liquid reproduction materials are poured into layers on steel sheets which serve as a carrier layer provided with adhesive varnish, and 27

DK 162722 B

distributes by means of a 800 mm film thickness, and the layers are then covered to exclude air with 6 mm transparent polyester film. The liquid layers of the reproduction material are illuminated through the negative placed on the polyester film with a commercially available mercury pressure lamp. The negative and polyester foil are removed and then the unlit layers of the reproduction material are washed with a 0.5% aqueous soda solution.

The relief molds produced are dried and illuminated simultaneously for 2 minutes. As the correct illumination time at which all the required elements, ie: raster with 40 lines / cm and a tone value of 3%, exposed points with a diameter of the printed surface of 0.3 mm, fine lines with a cross section of 0.3 mm , fine lines with a cross section of 15 0.07 mm are anchored correctly on the carrier metal, under the given conditions 9 illumination units are measured with a commercially available illumination machine. The relief is correct and meets the requirements set.

20 Comparative Experiments C

Exactly as in Example 13, however, 8 parts of benzyl dimethyl ketal were used instead of the 2,4,6-trimethylbenzoyl diphenylphosphine oxide.

25

With this liquid reproduction material, a required illumination time of 23 illumination units, i.e. one with the factor 2.5 extended illumination time.

EXAMPLE 14 294 parts of a partially saponified polyvinyl acetate (saponification 82 mol%, average polymerization degree * 500) 35 are dissolved by stirring for 29 hours in 294 parts of water at 90 ° C. After cooling to 70 ° C, 200 parts of a monomeric mixture consisting of 180 parts of 2-hydrate are added with stirring.

DK 162722 B

28 oxyethyl methacrylate, 20 parts of 1,1-trimethylolpropane triacrylate, 10 parts of 2,4,6-trimethylbenzoyl diphenylphosphine oxide and 2 parts of 2,6-di-tert-butyl-p-cresol. The homogeneous viscous solution is filtered and evaporated under reduced pressure. When applied to an adhesive coated steel plate and 24 hours drying at room temperature, a 550 mn thick non-adhesive layer of the reproduction material is obtained. After 2 seconds of pre-illumination and subsequent illumination of 40 seconds through a negative in a fluorescent tube 10 flat lights and subsequent leaching with water in a spray washer and drying at 100 ° C a cliché with good relief structure and excellent mechanical properties is obtained.

Several thousands of prints can be printed with this form. The printing forms of printing give excellent readable 15 negative prints which fully meet the requirements for producing newspapers.

EXAMPLE 15 A printing plate is prepared as described in Example 14 with the reproduction material, however, instead of 2,4,6-trimethylbenzoyl diphenylphosphine oxide, it contains the same amount of 2,6-dimethoxybenzoyl diphenylphosphine oxide. The pre-lighting time is approx. 2 seconds, the required time for visual illumination 45 seconds.

Comparative Experiments D and E

As described in Example 14, a printing plate was prepared with the reproduction material which, however, as the photo-initiator in the same amounts, contains the known initiators benzildimethylketal (comparative experiment D) or benzoin isopropyl ether (comparative experiment E). Comparison of the required illumination time 35 of reproduction materials with the same amount of content of the photoinitiator in question showed the following results: 29

DK 162722 B

Reproduction material Pre- Imaging containing illumination illumination 2.4.6- dimethylbenzoyl diphenylphosphine oxide (ex. 14) 2 sec. 40 sec.

2,6-dimethoxybenzoyl diphenylphosphinoic acid (Ex. 15) 2 sec. 45 sec.

Benzild dimethyl ketal (comparative experiment D) 4 sec. 90 sec.

Benzoin isopropyl ether (comparative experiment E) 6 sec. 120 sec.

15

Comparison of relief printing molds made from the illuminated printing plates from Comparative Experiment D and relief printing molds prepared from Example 14 showed that Comparative Experiment D yielded poorly formed and blurry negative prints.

EXAMPLE 16 and Comparative Experiments F

As in Example 14 and Comparative Experiment D, 25 special printing plates were prepared in the same manner which differed only in that in one case they contained 2,4,6-trimethylbenzoyl diphenylphosphine oxide (Example 1) and in the other case contained benzyl dimethyl ketal (Comparative Experiment F ) in the photopolymerizable layer of the reproduction material. Adjacent to each other, the various plates without illumination were imaged directly with a commercially available iron-doped mercury high pressure lamp with a reflector at a distance of 75 cm and with an electrical power consumption of the 5 kW / h UV burner through a negative 35. The required minimum illumination time was determined. This was for the printing plates made as in Example 1 (the present invention) 60 seconds, for printing plates made as

DK 162722B

30 comparative trials F 110 seconds.

5 10 15 20 25 30 35

Claims (7)

A photopolymerizable recording material, especially 5 for the production of printing plates and embossing molds, consisting predominantly of a photoinitiator-containing mixture of a) at least one low molecular weight compound with at least one photopolymerizable olefinically unsaturated double bond and b) at least one organic polymeric binder characterized by It contains, as a photoinitiator, acylphosphine oxide compounds of the formula Wherein R 1 represents an alkyl group of 1-6 carbon atoms, a cycloalkyl group of 5 or 6 ring atoms, an optionally halogenated, alkyl or alkoxy substituted aryl group or an S or N-containing five- or six-membered heterocyclic group; 25 represents the same as r 1, wherein R 3 and may be the same or different, or represent an alkoxy, aryloxy or aryl alkoxy group, or R and R are bonded together to a ring; R 3 represents a tertiary alkyl group having 4-18 carbon atoms or a tertiary cycloalkyl group having 5 or 6 ring carbon atoms or a cycloalkyl group, aryl group or a five- or six-membered heterocyclic group, wherein at least in both o-positions of the carbonyl group there are B is substituents A and B which may be the same or different and represent alkyl, alkoxy, alkoxyalkyl, alkyl thio, cycloalkyl or aryl groups or halogen atoms. 5 Photopolymerizable recording material according to claim 1, characterized in that it contains an acyl phosphine oxide compound of formula I wherein R 2 represents 2 an aryl group of 6-12 carbon atoms and R represents a 10 alkoxy group of 1-4 carbon atoms or an aryl group of 6-12 carbon atoms. Photopolymerizable recording material according to claim 1 or 2, characterized in that it contains an acylphosphine oxide compound of formula I, wherein R represents a tertiary alkyl group of 4-18 carbon atoms or a tertiary cycloalkyl group of 5 or 6 ring carbon atoms. Photopolymerizable recording material according to claim 3 1 or 2, characterized in that R represents a phenyl group substituted at least in the 2,6 positions with groups A and B. Photopolymerizable recording material according to any one of claims 1-4, characterized in that it contains a tertiary amine. Photopolymerizable recording material according to any one of claims 1-5, characterized in that it contains as an organic polymeric binder a linear polyamide, an unsaturated polyester or a polymer with repeated vinyl alcohol groups in the molecular chain. 1 A method of producing relief molds by pictorial illumination of a layer of a photopolymerizable recording material applied to a support material and the subsequent removal of unlit portions of the recording material layer, characterized in that a photopolymerizable recording material is used according to a any of claims 1-6. 5 10 15 20 25 30 35