CH691684A5 - Organo-boron compound - Google Patents

Abstract

A compound of formula (I) is new. - In (I), R1 = 1-20C alkyl, 3-12C cycloalkyl, 2-8C alkenyl, phenyl-1-6C alkyl or naphthyl-1-3C alkyl optionally interrupted by O, S(O)p and/or NR5 or optionally substituted by 1-12C alkyl, OR6, R7S(O)p, R7S(O)2O, NR8R9, SiR10R11R12, BR13R14 or R15R16P(O)q; R2, R3 and R4 = phenyl or biphenyl optionally substituted with 1-12C alkyl (optionally substituted with OR6, NR8R9 or halogen), OR6, R7S(O)p, R7S(O)2O, R8R9NS(O)2, NR8R9, NR8R9CO, SiR10R11R12, BR13R14, halogen, R15R16P(O)q or a group of formulae (Ia)-(If), where the sum of the Hammett sigma -constants ( sigma ) or R2, R3 and R4 is between +0.36 and +2.58; X = O, S or NR21; R5 = H, 1-12C alkyl, phenyl-1-6C alkyl (optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen) or phenyl (optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen); R6 and R7 = 1-12C alkyl (optionally substituted with halogen), phenyl-1-6C alkyl (optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen) or phenyl (optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen); R8-R16 = 1-12C alkyl, 3-12C cycloalkyl, phenyl-1-6C alkyl (optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen) or phenyl (optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen) or R8 and R9, together with the N to which they are attached, form a 6-membered aliphatic ring optionally containing O or S heteroatom; R17-R20 = H, 1-12C alkyl (optionally substituted with 1-12C alkoxy), phenyl or phenyl-1-6C alkyl (either of which is optionally substituted 1-5 times by 1-6C alkyl, 1-12C alkoxy or halogen); p = 0-2; r = 0-5; R21 = H or 1-12C alkyl; R22, R22a, R23 and R24 = H, 1-12C alkyl( optionally substituted by 1-12C alkoxy, OH or halogen) or phenyl (optionally substituted by 1-12C alkoxy, OH or halogen); q = 0 or 1; and G = a radical which is able to form positive ions. - Also claimed are: (i) a composition comprising: (a) ethylenically unsaturated compound(s); (b) compound(s) containing an acidic group, which may also be present in (a); (c) photoinitiator(s) of formula (I); and optionally (d) coinitiator(s); (ii) a process for the photopolymerisation of non-volatile monomeric, oligomeric or polymeric compounds containing ethylenically unsaturated double bond(s) and compound(s) containing an acidic group; (iii) a substrate which is coated on its surface(s) with a composition as in (i); (iv) a process for the photographic production of relief images which comprises subjecting a coated substrate as in (iii) to imagewise exposure and removing the unexposed areas with a solvent; (v) a process for producing relief images which comprises exposing a coated substrate as in (iii) by means of a movable laser beam (without mask) and subsequently removing the unexposed areas with a solvent; and (vi) a process for the thermal polymerisation of compounds containing ethylenically unsaturated double bonds, which comprises using (I) as an initiator.

Description

       

  



  The invention relates to highly reactive borate photoinitiator compounds which are stable in acidic media, photopolymerizable compositions containing these compounds, and the use of the compounds as initiators for the polymerization.



  The use of borates as photoinitiators in combination with coinitiators is known in the prior art. For example, U.S. Patents 4,772,530, 4,772,541 and 5,151,520 triarylalkyl borate anions with cationic dyes such as e.g. Cyanines, rhodanines, etc., as counterions. These compounds are used as photoinitiators. In U.S. Patent 4,954,414, cationic transition metal complexes are used together with triarylalkyl borate anions in photopolymerizable compositions. It is also known from U.S. Patent 5,055,372 the use of quaternary ammonium compounds such as e.g. Tetramethylammonium, pyridinium, cetylpyridinium etc., as cationic counterions to the triarylalkyl borate. In this publication, the borates are used in conjunction with aromatic ketone initiator compounds as coinitiators in photocurable materials.

   These borates are not stable in media which contain components with acid groups and can therefore not be used as photoinitiators in such media.



  In the art there is a need for stable reactive compounds for the extensive field of application of photointiators, in particular also those which are stable in the acidic medium.



  It has now surprisingly been found that certain monoborate compounds are sufficiently stable and reactive even in acidic media. The invention therefore relates to compounds of the formula (I)
EMI1.1
 
 



  wherein
 R1 is C1-C20-alkyl, C3-C12-cycloalkyl, C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl, the radicals being C1-C20-alkyl, C3-C12-cycloalkyl , C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl can be interrupted with one or more groups O, S (O) p or NR5 or where the residues C1-C20-alkyl, C3 -C12-Cycloalkyl, C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl unsubstituted or with C1-C12-alkyl, OR6, R7S (O) p, R7S (O) 2O, NR8R9 , SiR10R11R12, BR13R14 or R15R16P (O) q, are substituted; R2, R3 and R4 independently of one another are phenyl or biphenyl, the radicals phenyl or biphenyl being unsubstituted or with C1-C12-alkyl which is unsubstituted or substituted by OR6, NR8R9 or halogen, OR6, R7S (O) p, R7S (O) 2O, R8R9NS (O) 2, NR8R9, NR8R9CO,
EMI2.1
 



  , SiR10R11R12, BR13R14, halogen, R15R16P (O) q,
EMI2.2
 



  or
EMI2.3
 
 are substituted;
 characterized in that the sum of the Hammett sigma constants (SIGMA sigma) of the substituents on the aromatic radicals R2, R3 and R4 is between + 0.36 and + 2.58;
 X represents O, S or NR21;
 R5 is hydrogen, C1-C12-alkyl, unsubstituted or mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- or pentasubstituted by C1-C6-alkyl , C1-C12 alkoxy or halogen substituted phenyl;
 R6 and R7 unsubstituted or halogen-substituted C1-C12-alkyl, unsubstituted or mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentavalent C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl;



  R8, R9, R10, R11, R12, R13, R14, R15 and R16 independently of one another C1-C12-alkyl, C3-C12-cycloalkyl, unsubstituted or one to five times with C1-C6-alkyl, C1-C12-alkoxy or Halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentas with C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl, or R8 and R9 together with the N atom to which they are attached form a 6-membered aliphatic ring which may also contain oxygen or sulfur as a further heteroatom;
 R17, R18, R19 and R20 independently of one another are hydrogen, unsubstituted or C1-C12-alkoxy-substituted C1-C12-alkyl, phenyl or phenyl-C1-C6-alkyl, the radicals phenyl or phenyl-C1-C6-alkyl being unsubstituted or substituted one to five times with C1-C6-alkyl, C1-C12-alkoxy or halogen;
 p represents a number from 0 to 2;

  
 r represents a number from 0 to 5;
 R21 represents hydrogen or C1-C12-alkyl;
 R22, R22a, R23 and R24 independently of one another are hydrogen, unsubstituted or C1-C12-alkoxy, OH or halogen-substituted C1-C12-alkyl or unsubstituted or C1-C12-alkoxy, OH or halogen-substituted phenyl,
 q represents 0 or 1; and
 G represents a residue which can form positive ions.



  The invention also relates to compositions containing
 (a) at least one ethylenically unsaturated compound;
 (b) at least one compound containing an acidic group,
 wherein the acidic group can also be contained in component (a);
 (c) at least one photoinitiator of the formula (I); and
 (d) optionally one or more coinitiators.



  The compounds of the formula I are very reactive initiators for the photopolymerization of ethylenically unsaturated compounds, optionally with the addition of coinitiators.



  The compounds are characterized in that the sum of the Hammett sigma constants (SIGMA sigma) of the substituents on the aromatic radicals R2, R3 and R4 is between + 0.36 and + 2.58.



  If the radicals are phenyl or biphenyl, they are one to four times, e.g. mono-, di- or trisubstituted, in particular mono- or disubstituted.



  C1-C20 alkyl is linear or branched and is, for example, C1-C12, C1-C8, C1-C6 or C1-C4 alkyl. For example, it means methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, 2,4,4-trimethyl-pentyl, 2-ethylhexyl, octyl, Nonyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl or lcosyl. For example, R1 is C1-C12 alkyl, especially C1-C8 alkyl, preferably C1-C6 alkyl, e.g. Methyl, hexyl or butyl. If R1, R2, R3 and R4 are C1-C20-alkyl substituted with R9R10R11Si, the alkyl radical is e.g. C1-C12, especially C1-C8, preferably C1-C4 alkyl. Methyl is particularly preferred.



  C1-C12 alkyl and C1-C6 alkyl are also linear or branched and have e.g. the meanings given above up to the corresponding number of carbon atoms. R5, R6, R7, R8, R9, R10, R11, R12 and R13 are e.g. C1-C8, especially C1-C6, preferably C1-C4 alkyl, e.g. Methyl or butyl. C1-C6-alkyl substituents for phenyl-C1-C6-alkyl, phenyl or biphenyl are especially C1-C4-alkyl, e.g. Methyl or butyl. Cetyl is hexadecyl.



  C2-C20 alkyl which is interrupted one or more times by -O-, -S (O) p- or -NR5- is, for example, 1-9, e.g. 1-7 or 1 or 2 times interrupted by -O-, -S (O) p- or -NR5-. For example, Structural units such as -CH2-O-CH3, -CH2CH2-C) -CH2CH3, - [CH2CH2O] y-CH3, with y = 1-9, - (CH2CH2O) 7CH2CH3, -CH2-CH (CH3) -O-CH2- CH2CH3 or -CH2-CH (CH3) -O-CH2CH3.



  C3-C12 cycloalkyl means e.g. Cyclopropyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, especially cyclopentyl and cyclohexyl, preferably cyclohexyl.



  C2-C8-alkenyl radicals can be mono- or polyunsaturated and are, for example, allyl, meth-allyl, 1,1-dimethylallyl, 1-butenyl, 3-butenyl, 2-butenyl, 1,3-pentadienyl, 5-hexenyl or 7-octenyl, especially allyl. R4 as C2-C8 alkenyl is e.g. C2-C6, especially C2-C4 alkenyl.



  Phenyl-C1-C6-alkyl means e.g. Benzyl, phenylethyl, alpha-methylbenzyl, phenylpentyl, phenylhexyl or alpha, alpha-dimethylbenzyl, especially benzyl. Phenyl-C1-C4-alkyl, in particular phenyl-C1-C2-alkyl, is preferred. Substituted phenyl-C1-C6-alkyl is one to four times, e.g. substituted once, twice or three times, in particular once or twice on the phenyl ring.



  Substituted phenyl is one to five times, e.g. substituted once, twice or three times, in particular once or twice on the phenyl ring.



  Naphthyl-C1-C3-alkyl is, for example, naphthylmethyl, naphthylethyl, naphthylpropyl or naphthyl-1-methylethyl, especially naphthylmethyl. The alkyl unit can be in the 1- or 2-position of the naphthyl ring. Substituted naphthyl-C1-C3-alkyl is one to four times, e.g. substituted once, twice or three times, in particular once or twice, on the aromatic rings.



  C1-C12-alkoxy stands for linear or branched radicals and means e.g. Methoxy, ethoxy, propoxy, isopropoxy, n-butyloxy, sec-butyloxy, iso-butyloxy, tert-butyloxy, pentyloxy, hexyloxy, heptyloxy, 2,4,4-trimethylpentyloxy, 2-ethylhexyloxy, octyloxy, nonyloxy, decyloxy or dodecyloxy, in particular methoxy, ethoxy, propoxy, isopropoxy, n-butyloxy, sec-butyloxy, isobutyloxy, tert-butyloxy, preferably methoxy.



  Halogen means fluorine, chlorine, bromine and iodine, in particular chlorine, bromine and fluorine, preferably chlorine and fluorine.



  If C1-C20-alkyl is substituted one or more times with halogen, e.g. 1 to 3 or 1 or 2 halogen substituents on the alkyl radical.



  If R8 and R9 form a ring together with the N atom to which they are attached, they are e.g. around a piperidine ring. If the ring is interrupted by oxygen, the rest means e.g. Morpholino.



  As counterion G Residues which can form positive ions are generally suitable for the negative borate in formula I. These are, for example, alkali metals, in particular lithium or sodium, quaternary ammonium compounds, dye cations or cationic transition metal coordination complex compounds. Ammonium, tetraalkylammonium or dye cations are preferred. An example of tetraalkylammonium is tetra (C1-C4-alkyl) ammonium. This includes compounds of the following formula: N (C1-C4-alkyl) <+>, where C1-C4-alkyl can have the meanings given above up to the corresponding number of carbon atoms. Examples of corresponding ammonium compounds are tetramethylammonium, tetraethylammonium, tetrapropylammonium or tetrabutylammonium, in particular tetramethylammonium and tetrabutylammonium. Benzyltri (C1-C4-alkyl) ammonium is also suitable.

   That means C6H5-CH2-N (C1-C4-alkyl) 3 <+>, where C1-C4-alkyl may have the meanings given above up to the corresponding number of carbon atoms. Examples of such radicals are benzyltrimethylammonium, benzyltriethylammonium, benzyltripropylammonium and benzyltributylammonium, especially benzyltrimethylammonium and benyzltributylammonium. Trisalkylammonium ions are also suitable, e.g. Trimethylammonium. Phosphonium and ammonium counterions of the formulas are suitable <+> PRwRxRyRz and <+> NRwRxRyRz, where Rw, Rx, Ry, Rz independently of one another represent hydrogen, unsubstituted or substituted alkyl, cycloalkyl, alkenyl, phenyl or arylalkyl. Substituents for these alkyl, cycloalkyl, alkenyl, phenyl or arylalkyl radicals are e.g.

   Halide, hydroxy, heterocycloalkyl (e.g. epoxy, aziridyl, oxetanyl, furanyl, pyrrolidinyl, pyrrolyl, thiophenyl, tetrahydrofuranyl, etc.), dialkylamino, amino, carboxy, alkyl and arylcarbonyl, and aryloxy and alkoxycarbonyl.



  The tetravalent nitrogen can also be a member of a 5- or 6-membered ring, which ring can in turn be fused to other ring systems. These systems can also contain additional heteroatoms, e.g. S, N, O.



  The tetravalent nitrogen can also be a member of a polycyclic ring system, e.g. Azonia propellan. These systems can also contain other heteroatoms, e.g. S, N, O.



  Also suitable are polyammonium and polyphosphonium salts, in particular the bite salts, where the same substituents as described above for the "mono" compounds may be present.



  The ammonium and phosphonium salts can also be substituted with neutral dyes (e.g. thioxanthenes, thioxanthones, coumarins, ketocoumarins, etc.). Such salts are obtained from the reaction of the ammonium and phosphonium salts substituted with reactive groups (e.g. epoxy, amino, hydroxy, etc.) with suitable derivatives of neutral dyes. Corresponding examples are described in EP-A 224 967 (Quantacure QTX).



  Ammonium and phosphonium salts can also be substituted with colorless electron acceptors (e.g. benzophenones): Examples of this are Quantacure ABQ
EMI7.1
 



   Quantacure BPQ
EMI7.2
 and Quantacure BTC
EMI7.3
 from International Bio-Synthetics.



  Other interesting quaternary ammonium compounds are e.g. Trimethylcetylammonium or cetylpyridinium.



  As positive counterions G <+> in the compound of formula I are e.g. also use the following ions:
EMI7.4
 
EMI7.5
 
 
 wherein Z is P, S or N and R is an alkyl or aryl radical. Connections such as e.g.
EMI7.6
 or
EMI7.7
 (described by Yagci et al. in J. Polym. Sci. Part A: Polymer Chem. 1992, 30, 1987 and Polymer 1993, 34 (6), 1130), or as e.g.
EMI7.8
 or
EMI8.1
 R min = unsubstituted or substituted benzyl or phenacyl (described in JP-A Hei 770 221). In these compounds, the aromatic rings in the pyridinium can also be substituted.



  As positive counterions G Other onium ions, such as e.g. Iodonium or sulfonium ions can be used.



  Examples of such counterions to the borate are residues of the formula
EMI8.2
 such as are described in EP-A 555 058 and EP-A 690 074. Also interesting as counterions
EMI8.3
 
 
EMI8.4
 



  .



  Further suitable counterions for the borates according to the invention are cations of the formula
EMI8.5
 
 
 



  wherein R9 represents an alkyl radical, in particular ethyl, or benzyl and the aromatic ring can carry further substituents.



  Other suitable counterions are halonium ions, especially diaryliodonium ions, e.g. in EP-A 334 056 and EP-A 562 897.



  However, cations of ferrocenium salts, such as described in EP-A 94 915 and EP-A 109 851, for example
EMI8.6
 
 



  Other suitable "onium" cations such as ammonium, phosphonium, sulfonium, iodonium, selonium, arsonium, tellonium, bismuthonium are e.g. in Japanese Patent Application Hei 6 266 102.



  Examples of cationic transition metal complex compounds which are useful as counterions are described in U.S. Patent 4,954,414. Bis (2.2 min -bipyridine) (4.4 min -dimethyl-2.2 min -bipyridine) ruthenium, Tris (4.4 min -dimethyl-2.2 min -bipyridine) ruthenium, Tris ( 4.4 min dimethyl 2.2 min bipyridine) iron, tris (2.2 min, 2 min min terpyridine) ruthenium, tris (2.2 min bipyridine) ruthenium and bis (2.2 min -bipyridine) (5-chloro-1,10-phenanthroline) ruthenium.



  Dyes suitable as counterions are, for example, cations of triarylmethanes, e.g. Malachite green, indolines, thiazines, e.g. Methylene blue, xanthones, thioxanthones, oxazines, acridines, cyanines, rhodamines, phenazines, e.g. Saffron.



  Also dyes with acid groups, e.g. Methyl red, ethyl orange, methyl orange, acid yellow, rosolic acid, phenol red, fluorescein, rose bengal, thymolphthalein monophosphoric acid, auramine O, cresyl violet, rhodamine B, brilliant green or variant blue are suitable.



  If the compounds of the formula I do not contain any dye as counterion and at the same time the corresponding borate is not sufficiently absorbent, it is expedient to add at least one coinitiator or electron acceptor (d) to the composition for the photopolymerization process. The term coinitiator is used in this application e.g. also for sensitizers (= energy carriers), e.g. Thioxanthones, dyes or reaction accelerators, e.g. Amines, thiols, etc. These are preferably dyes. Suitable dyes which can be added as coinitiators are e.g. in U.S. Patent 5,151,520. For example, triarylmethanes, e.g. Malachite green, indolines, thiazines, e.g. Methylene blue, xanthones, thioxanthones, oxazines, acridines or phenazines, e.g. Saffron.



  The transition metal complex compounds or onium ion compounds described above can also be used as coinitiators.



  Cationic, neutral or anionic dyes can be used as coinitiators for the compounds according to the invention.



  Particularly suitable cationic dyes are malachite green, methylene blue, safranine O, rhodamines of the formula III
EMI10.1
 
 
 



  where R and R min are alkyl or aryl, e.g. Rhodamine B, Rhodamine 6G or Violamin R, also Sulforhodamine B or Sulforhodamine G.



  Other suitable dyes are fluorones, e.g. by Neckers et al. in J. Polym. Sci., Part A, Poly. Chem, 1995, 33, 1691-1703. Is particularly interesting
EMI10.2
 
 



  Examples of other suitable dyes are cyanines of the formula IV
EMI10.3
 
 
 



  where R = alkyl; n = 0, 1, 2, 3 or 4 and Y1 = CH = CH, N-CH3, C (CH3) 2, O, S or Se. Preferred are cyanines, wherein Y1 in formula IV is C (CH3) 2 or S.



  The following dye compounds are also suitable as coinitiators:
EMI10.4
 
 



  wherein
 Z represents P, S or N and R represents an alkyl or aryl radical. Preferred compounds of the above formulas are those in which ZR3 is N (CH3) 3, N (C2H5) 3 or P (C6H5) 3.



  Connections such as e.g.
EMI11.1
 
 
 



  such as by Yagci et al. in J. Polym. Sci. Part A: Polymer Chem. 1992, 30, 1987 and Polymer 1993, 34 (6), 1130. Connections such as e.g.
EMI11.2
 
 
 



  with R min = unsubstituted or substituted benzyl or phenacyl (described in JP-A Hei 770 221). In these compounds, the aromatic rings in the pyridinium can also be substituted.



  Other suitable dyes can be found, for example, in US Pat. No. 4,902,604. They are azulene dyes. Of particular interest as coinitiators for the compounds according to the invention are the compounds 1-18 given in columns 10 and 11 of this patent in the table.



  Other suitable dyes are e.g. Merocyanine dyes as described in U.S. Patent 4,950,581 from column 6, line 20 to column 9, line 57.



  Coumarin compounds can also be used as coinitiators for the compounds or photoinitiators according to the invention. Examples of this are given in U.S. Patent 4,950,581 in columns 11, line 20 through column 12, line 42.



  Other suitable coinitiators are xanthones or thioxanthones, e.g. in U.S. Patent 4,950,581, column 12, line 44 to column 13, line 15.



  Anionic dye compounds, for example, can also be used as coinitiators. For example, Rose Bengal, Eosin or Fluorescein are also suitable as coinitiators. Other suitable dyes, such as from the triarylmethane or azo class, e.g. in U.S. Patent 5,143,818.



  Also suitable are e.g. Benzoxanthene, benzothioxanthene, pyronine or porphyrin dyes or UV absorbers. These are e.g. Thioxanthone derivatives, coumarins, benzophenone, benzophenone derivatives or hexaarylbisimidazole derivatives.



  Suitable hexaarylbisimidazole derivatives are e.g. in U.S. Patents 3,784,557, 4,252,887, 4,311,783, 4,459,349, 4,410,621 and 4,622,286. Of particular interest are 2-o-chlorophenyl-substituted derivatives such as e.g. 2.2 min -bis (o-chlorophenyl) -4.4 min, 5.5 min -tetraphenyl-1.1 min -bisimidazole. Other suitable UV absorbers in this context are e.g. polycyclic aromatic hydrocarbons, e.g. Anthracene or pyrene, as well as the triazines described in EP-A-137 452, DE-A-2 718 254 and DE-A-2 243 621. Further suitable triazines can be found in US Pat. No. 4,950,581 column 14, line 60 to column 18, line 44. Trihalomethyltriazines, e.g. 2,4-bis (trichloromethyl) -6- (4-styrylphenyl) -s-triazine.



  The sum of the Hammett sigma constants (SIGMA sigma) of the substituents on the aromatic radicals R2, R3 and R4 of the photoinitiators of the formula I in the compositions according to the invention must be between + 0.36 and + 2.58. This means that values that are greater than + 0.36 and at the same time less than + 2.58 must be available. Compounds with the values + 0.36 and + 2.58 are inactive in substrates containing acid-forming groups.



  The sum of the sigma constants of the compounds according to the invention is between + 0.36 and + 2.58, e.g. 0.39 and + 2.52, + 0.42 and + 2.49, or + 0.48 and + 2.43, for example + 0.54 and + 2.37 or + 0.60 and + 2.31, especially between + 0.69 and + 2.04.



   Hammig proposed sigma constants to quantify the effect of a substituent X on the dissociation of the corresponding benzoic acid XC6H4COOH. The sigma constants are defined by the following equation: log k / k0 = sigma rho k0 is the equilibrium constant for XC6H4COOH, with X = H (i.e. benzoic acid), k is the constant for XC6H4C0OH. rho is a reaction-specific constant for a reaction under certain conditions. Obviously rho has the value 1 for the dissociation of benzoic acid. Hydrogen is assigned the sigma constant 0.00, while electron donor groups, which make the dissociation of a substituted benzoic acid difficult, receive negative sigma constant values. Electron-withdrawing groups that increase the acidity of the substituted benzoic acid have positive values of the sigma constant.

   The order of magnitude of the values of the sigma constants depends on the field and resonance effects of the respective substituent. See J. March, Advanced Organic Chemistry, Third Edition, McGraw-Hill Book Company, New York, 1985, pp. 242-250. The Hammett equation is valid for a large number of reactions under the most varied reaction conditions (Jaffé, Chem. Rev. 1953, 53, 191-261). Little et al. determined (J. Amer. Chem. Soc. 1964, 86, 1376), for example, the Hammett sigma constants of substituents on phenylferrocenes. Factors that influence the oxidation of such ferrocene derivatives also play a role in the consideration of borate photoinitiators because the production of initiating radicals takes place through oxidation of the borate.

   Little et al. also show a good correlation between the measured oxidation potentials of the ferrocene derivatives and the sigma constants for meta and para substitutes (sigma m, sigma p) from table values. Little et al. established a good connection between these values and the corresponding constants for ortho substituents (sigma o). Charton presents in Can. J. Chem. Vol. 38, 1960, 2493-2499, found that the o and p values for the substituents are very similar. In the event that no values for o-substituents are given in the tables published by Little and in the tables below, the corresponding values for the p-substituents can be used.

   Values for sigma o, sigma m and sigma p for common substituents can be found, for example, in tables in the publications mentioned above or also by C. Gardner Swain et al. in J. Amer. Chem. Soc. 1968 4328-4337. A detailed list is also provided by O. Exner in Correlation Analysis in Chemistry: Recent Advances, Plenum, New York, 1978, 439-540. For substituents that are not included in these lists, the values of the respective sigma constants can be determined by measuring the oxidation potential (as described by Little et al. In the article cited above) or by determining the acid strength of the corresponding benzoic acids.



  Preferred compounds of the formula I are those in which R1 is C1-C20-alkyl, C3-C12-cycloalkyl, C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl, these radicals being unsubstituted or with C1-C12-alkyl are substituted.



  Also of interest are compounds of the formula I in which R1 is C1-C12-alkyl, allyl, cyclopentyl, cyclohexyl, benzyl or naphthylmethyl.



  Also preferred are compounds of the formula I in which R2, R3 and R4 independently of one another are phenyl or biphenyl, these radicals being unsubstituted or with C1-C6-alkyl which is unsubstituted or substituted with OR6, NR8R9 or fluorine or OR6, NR8R9, BR13R14, R7S ( O) p, R7S (O) 20 or
EMI13.1
 are substituted.



  Further preferred compounds of the formula I are those in which R2, R3 and R4 independently of one another are phenyl or biphenyl, these radicals being unsubstituted or with C1-C12-alkyl, trifluoromethyl,
EMI14.1
 OR6, NR8R9, halogen, BR13R14, R7S (O) p, R7S (O) 2O or
EMI14.2
 are substituted; Y1 is C1-C12 alkyl or phenyl; R6 is C1-C12-alkyl, trifluoromethyl, phenyl substituted with C1-C6-alkyl, C1-C12-alkoxy or halogen; R7 represents C4-C12-tert-alkyl, trifluoromethyl or phenyl substituted with C1-C6-alkyl, C1-C12-alkoxy or halogen; R8 and R9 are C1-C12-alkyl, phenyl or phenyl-C1-C6-alkyl or R8 and R9 together with the N atom to which they are attached form a morpholino ring; R13 and R14 are phenyl which is mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen;

   R17, R18, R19 and R20 independently represent C1-C12-alkyl which is unsubstituted or substituted by C1-C12-alkoxy or phenyl which is substituted by C1-C6-alkyl, C1-C12-alkoxy or halogen.



  Other preferred compounds of formula I are those in which R2, R3 and R4 in formula I are the same.



  Preference is also given to compounds of the formula I in which G is a dye or metal complex, sulfonium, sulfoxonium or iodonium cation or G is a UV absorber compound which can form cations, or G is a metal cation of the group I of the periodic table, or G is a cation MY <+>, where M is a metal from group II of the periodic table and Y is alkoxy or halogen, or G is an ammonium or phosphonium salt.



  Also preferred are compounds of the formula I in which R1 is C1-C6-alkyl, R2, R3 and R4 are the same and phenyl which is mixed with phenoxy, R8R9NS (O) 2, NR8R9CO,
EMI15.1
 



   Fluorine, bromine, chlorine, with halogen-substituted C1-C4-alkyl or
EMI15.2
 is substituted mean; R8 and R9 are C1-C4 alkyl; R21 represents C1-C4-alkyl; r represents the number 3; and G ammonium, trimethylammonium, tetramethylammonium, tetrabutylammonium, tetradecylammonium, trimethyl-n-cetylammonium, cetylpyridinium, methyl-2-chloropyridinium, trimethyl-hydroxymethylammonium, triethyl-3-bromopropyl-ammonium, triphenylhenyliononium, triphenylhenylionononium, triphenylshenononium, blue-triphenylsulfonium , Safranin O-cation, 3,4-dimethyl-2- (2-hydroxy-3-trimethylaminopropoxy) thioxanthone cation, (CH3) 3N <+> (CH2) 6N <+> (CH3) 3,
EMI 15.3
 
 
EMI 15.4
 
 
EMI15.5
 
 
EMI 15.6
 



  is.



  The compounds of formula I can e.g. by reacting triorganylboranes (A) with organometallic reagents, e.g. Alkyl lithium compounds or Grignard reagents are obtained:
EMI15.7
 
 



  M is e.g. an alkali metal, such as Li or Na, or MgX, where X represents a halogen atom, in particular Br.



  Another possibility for the preparation of the compounds of the formula I is, for example, the reaction of alkyldihaloboranes or alkyldi (alkoxy) boranes or alkyldi (aryloxy) boranes (B) with organometallic compounds, e.g. Grignard reagents or lithium organyl compounds:
EMI16.1
 
 



  X stands for halogen, in particular Br, X min means halogen, alkoxy or aryloxy. The meanings of the other radicals are as stated above.



  In the event that G in the formula I given above represents a positive radical other than lithium or magnesium, these compounds can e.g. can be obtained by cation exchange reactions.



  The reaction conditions when working with organometallic reagents are generally familiar to the person skilled in the art. For example, the reaction is conveniently carried out in an inert organic solvent, for example an ether or aliphatic hydrocarbon, e.g. Diethyl ether, tetrahydrofuran or hexane.



  The organometallic reagents for the preparation of the polyborates according to the invention are, for example, the lithium compounds of the corresponding aliphatic and aromatic hydrocarbon radicals. The production of Grignard reagents is familiar to the person skilled in the art and is described in a variety of ways in textbooks and other publications.



  The reaction with the organometallic reagent is conveniently carried out in the absence of air in an inert gas atmosphere, e.g. carried out under nitrogen. The reaction is usually carried out with cooling to 0 ° C. or below and then heating to room temperature.



  It is advisable to stir the reaction mixture. The isolation and cleaning of the products is also carried out according to methods generally known to the person skilled in the art, e.g. Chromatography, recrystallization, etc.



  If the compounds of the formula I according to the invention contain a dye residue as a cation, these compounds are prepared by cation exchange reaction of a corresponding borate salt with a dye. The borate salts suitable for exchange are e.g. the lithium, magnesium, sodium, ammonium or tetraalkylammonium salts.



  If the compounds of the formula I according to the invention contain a transition metal complex as a cation, these compounds are prepared analogously to the method described in US Pat. No. 4,954,414, column 7, section 2.



  The production of some triorganylboranes (A) is e.g. by Wittig et al. in Chem. Ber. 1955, 88, 962.



  Access to some alkyl dihaloboranes (B) is e.g. by Brown et al. in JACS 1977, 99, 7097, and U.S. Patent 3,083,288. Mikailov et al. in Zh. Obshch. Khim. 1959, 29, 3405, and Tuchagues et al. in Bull. Chim. Soc. France, 1967, 11, 4160, describe the preparation of such compounds. The alkyl dialkoxy and alkyl diaryloxy boranes can be prepared according to various published regulations, e.g. Brown et al. Organometallics 1983, 2, 1316; Brown et al. Organometallics 1992, 11, 3094; Brown et al. J. Org. Chem. 1980, 2, 1316.



  The boranes required as starting materials for the compounds according to the invention can be obtained, for example, in accordance with one of the published methods mentioned above.



  According to the invention, the compounds of the formula I can be used as photoinitiators for the photopolymerization of acidic compositions comprising at least one ethylenically unsaturated compound and at least one acidic group, the acidic group also being able to be present in the ethylenically unsaturated compound.



  This use can also be made in combination with other photoinitiators, coinitiators and / or other additives.



  As additives, e.g. Coinitiators or electron acceptors are used. Suitable coinitiators are e.g. Benzopteridinedione (described in JP Hei 02 113 002), substituted benzophenones (e.g. Michler's Ketone, Quantacure ABQ, Quantacure BPQ and Quantacure BTC from International Biosynthetics), trichloromethyltriazines (described in JP Hei 01 033 548), metal complexes (described in JP Hei 04 261 405), porphyrins (described in JP Hei 06 202 548 and JP Hei 06 195 014), coumarins and ketocoumarins (described in US 4 950 581 and JP Hei 06 175 557), p-aminophenyl compounds (described in EP-A 475 153), xanthenes (described in JP Hei 06 175 566) or pyrilium, thiopyrilium and selenopyrilium dyes (described in JP Hei 06 175 563).



  Easily reducible compounds are also suitable as additives. In this context, an easily reducible compound also includes compounds as described in US Pat. No. 4,950,581, for example also iodonium salts, sulfonium salts, organic peroxides, compounds with carbon-halide bonds (trichloromethyltriazines), heterocyclic sulfur compounds and other photoinitiators (alpha aminoketones). Other additives include heterocylene, as described in patents and patent applications US 5 168 032, JP 02 244 050, JP 02 054 268, JP 01 017 048 and DE 383 308.



  Other additives are e.g. aromatic imines, described in US Pat. No. 5,079,126 and US Pat. No. 5,200,292 (eg iminoquinonediazides), thiols, described in US Pat. No. 4,937,159, and thiols and N, N-dialkylanilines, described in US Pat. No. 4,874,685. Several of the electron acceptors listed can also be used and additives can be used in combination.



  As already mentioned, the combination of the borate compounds according to the invention with coinitiators, e.g. even those that act as sensitizers (= energy transfer) are advantageous. Combinations with several different sensitizers, such as e.g. Mixtures of the borate compounds according to the invention with "onium" salts and thioxanthones or coumarins or dyes, very effectively. Preferred "onium" salts in these mixtures are diphenyliodonium hexafluorophosphate, (p-octyloxyphenyl) (phenyl) iodonium hexafluorophosphate or corresponding other anions of these compounds, e.g. the halides; but also sulfonium salts, e.g. Triarylsulfonium salts (Cyracure <TM> UVI 6990, Cyracure Union Carbide's UVI-6974; Degacure <TM> KI 85 from Degussa or SP-150 and SP-170 from Asahi Denka).

   For example, a mixture of the borate compounds according to the invention with diphenyliodonium hexafluorophosphate and isopropylthioxanthone, a mixture of the borate compounds according to the invention with (p-octyloxyphenyl) (phenyl) iodonium hexafluorophosphate and isopropylthioxanthone, and a mixture of the borate compounds according to the invention are preferred
EMI19.1
 
EMI19.2
 
 (= Cyracure <TM> UVI-6974) and isopropylthioxanthone.



  However, it is also particularly advantageous to add a further photoinitiator of the alpha-aminoketone type to the mixtures mentioned above. For example, mixtures of the borates according to the invention with "onium" salts and thioxanthones or dyes and alpha-aminoketones are very effective. A preferred example is the mixture of the borate compounds according to the invention with diphenyliodonium hexafluorophosphate or (p-octyloxyphenyl) (phenyl) iodonium hexafluorophosphate, isopropythioxanthone and (4-methylthiobenzoyl) methyl-1-morpholino-ethane. Tetramethylammonium-hexyl-tris (m-fluorophenyl) borate is particularly suitable as a borate compound in these mixtures.



  According to the invention is also a composition containing, in addition to components (a), (b) and (c), at least one neutral, anionic or cationic dye or a thioxanthone and an onium compound. The invention furthermore relates to such a composition, which additionally contains a radical photoinitiator, in particular an alpha-aminoketone compound.



  The invention also relates to a composition comprising, in addition to components (a), (b) and (c), at least one compound of the formula XI
EMI 19.3
 
 
 



  wherein Ra, Rb, Rc and Rd independently of one another for C1-C12-alkyl, trimethylsilylmethyl, phenyl, another aromatic hydrocarbon, C1-C6-alkylphenyl, allyl, phenyl-C1-C6-alkyl, C2-C8-alkenyl, C2- C8-alkynyl, C3-C12-cycloalkyl or saturated or unsaturated heterocyclic radicals, where the radicals are phenyl, other aromatic hydrocarbon, phenyl-C1-C6-alkyl, and saturated or unsaturated heterocyclic radicals unsubstituted or with unsubstituted or with OR6, NR8R9 or Halogen substituted C1-C12 alkyl, OR6, R7S (O) p, R7S (O) 2O, R8R9NS (O) 2, NR8R9, NR8R9CO, SiR10R11R12, BR13R14, halogen or R15R16P (O) q are substituted;

  
 R6 and R7 unsubstituted or halogen-substituted C1-C12-alkyl, unsubstituted or mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentavalent C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl;
 R8, R9, R10, R11, R12, R13, R14, R15 and R16 independently of one another C1-C12-alkyl, C3-C12-cycloalkyl, unsubstituted or one to five times with C1-C6-alkyl, C1-C12-alkoxy or Halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentas with C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl, or R8 and R9 together with the N atom to which they are attached form a 6-membered aliphatic ring which may also contain oxygen or sulfur as a further heteroatom;
 p represents a number from 0 to 2;

  
 q represents 0 or 1; and
 E represents a radical which can form positive ions, in particular alkali metals, ammonium or tetraalkylammonium.



  The meanings of the residues C1-C12-alkyl, trimethylsilylmethyl, phenyl, other aromatic hydrocarbon, C1-C6-alkylphenyl, allyl, phenyl-C1-C6-alkyl, C2-C8-alkenyl, C2-C8-alkynyl, C3-C12- Cycloalkyl, saturated or unsaturated heterocyclic radical and radical, which can form positive ions, and for R6-R16 are as given above for formula I.



  In addition, according to the invention is a composition containing at least one borate of the formula I and at least one dye which changes or loses its color during or after the irradiation, which dye can also be a component of the compound of the formula I as a cation. Examples of such dyes are cyanine and pyrillium dyes.



  The unsaturated compounds which can be considered as component (a) can contain one or more olefinic double bonds. They can be low molecular weight (monomeric) or higher molecular weight (oligomeric). Examples of monomers with a double bond are alkyl or hydroxyalkyl acrylates or methacrylates, e.g. Methyl, ethyl, butyl, 2-ethylhexyl or 2-hydroxyethyl acrylate, isobornyl acrylate, methyl or ethyl methacrylate. Silicone acrylates are also interesting. Further examples are acrylonitrile, acrylamide, methacrylamide, N-substituted (meth) acrylamides, vinyl esters such as vinyl acetate, vinyl ethers such as isobutyl vinyl ether, styrene, alkyl and halostyrenes, N-vinyl pyrrolidone, vinyl chloride or vinylidene chloride.



  Examples of monomers with multiple double bonds are ethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol or bisphenol A diacrylate, 4.4 min bis (2-acryloyloxyethoxy) diphenylpropane, trimethylolpropane triacrylate, pentaerythritol triacrylate or vinytetracrylate or vinylacetate Divinylbenzene, divinylsuccinate, diallyl phthalate, triallyl phosphate, triallyl isocyanurate or tris (2-acryloylethyl) isocyanurate.



  Examples of higher molecular weight (oligomeric) polyunsaturated compounds are acrylated epoxy resins, acrylated or vinyl ether or epoxy group-containing polyesters, polyurethanes and polyethers. Further examples of unsaturated oligomers are unsaturated polyester resins, which are usually produced from maleic acid, phthalic acid and one or more diols and have molecular weights of approximately 500 to 3000. In addition, vinyl ether monomers and oligomers as well as maleate-terminated oligomers with polyester, polyurethane, polyether, polyvinyl ether and epoxy main chains can also be used. Combinations of vinyl ether group-bearing oligomers and polymers, as described in WO90 / 01512, are particularly suitable. Copolymers of vinyl ether and maleic acid functionalized monomers are also suitable.

   Such unsaturated oligomers can also be referred to as prepolymers.



  For example, Esters of ethylenically unsaturated carboxylic acids and polyols or polyepoxides, and polymers with ethylenically unsaturated groups in the chain or in side groups, e.g. unsaturated polyesters, polyamides and polyurethanes and copolymers thereof, alkyd resins, polybutadiene and butadiene copolymers, polyisoprene and isoprene copolymers, polymers and copolymers with (meth) acrylic groups in side chains, and also mixtures of one or more such polymers.



  Examples of unsaturated carboxylic acids are acrylic acid, methacrylic acid, crotonic acid, itaconic acid, cinnamic acid, unsaturated fatty acids such as linolenic acid or acidic acid. Acrylic and methacrylic acid are preferred.



  Aromatic and particularly aliphatic and cycloaliphatic polyols are suitable as polyols. Examples of aromatic polyols are hydroquinone, 4,4'-dihydroxydiphenyl, 2,2-di (4-hydroxyphenyl) propane, and novolaks and resols. Examples of polyepoxides are those based on the polyols mentioned, especially the aromatic polyols and epichlorohydrin. Polymers and copolymers which contain hydroxyl groups in the polymer chain or in side groups, such as e.g. Polyvinyl alcohol and copolymers thereof or polymethacrylic acid hydroxyalkyl esters or copolymers thereof, are suitable as polyols. Other suitable polyols are oligoesters with hydroxyl end groups.



  Examples of aliphatic and cycloaliphatic polyols are alkylene diols with preferably 2 to 12 carbon atoms, such as ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, hexanediol , Octanediol, dodecanediol, diethylene glycol, triethylene glycol, polyethylene glycols with molecular weights of preferably 200 to 1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,4-dihydroxymethylcyclohexane, glycerol, tris (beta-hydroxyethyl) amine, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol and sorbitol.



  The polyols can be partially or completely esterified with one or different unsaturated carboxylic acids, the free hydroxyl groups in partial esters being modified, e.g. can be etherified or esterified with other carboxylic acids.



  Examples of esters are:



  Trimethylolpropane triacrylate, trimethylolethane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, Tripentaerythritoctaacrylat, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate, Dipentaerythrittetramethacrylat, Tripentaerythritoctamethacrylat, pentaerythritol, Dipentaerythrittrisitaconat, dipentaerythritol, dipentaerythritol hexaitaconate, Ethylene glycol diacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diitaconate, sorbitol triacrylate, sorbitol tetraacrylate,

   Pentaerythritol-modified triacrylate, sorbitol tetramethacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylates and methacrylates, glycerol di- and triacrylate, 1,4-cyclohexane diacrylate, bisacrylates and bismethacrylates of polyethylene glycol with a molecular weight of 200 to 1500, or a molecular weight of 200 to 1500 thereof.



  Also suitable as component (a) are the amides of identical or different unsaturated carboxylic acids of aromatic, cycloaliphatic and aliphatic polyamines with preferably 2 to 6, particularly 2 to 4, amino groups. Examples of such polyamines are ethylenediamine, 1,2- or 1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine, 1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine, dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine, phenylenediamine, bisphenylenediamine, di-beta-aminoethyl ether, diethylene triamine, triethylene tetramine, di (beta-aminoethoxy) - or di (beta-aminopropoxy) ethane. Other suitable polyamines are polymers and copolymers with optionally additional amino groups in the side chain and oligoamides with amino end groups.

   Examples of such unsaturated amides are: methylene-bis-acrylamide, 1,6-hexamethylene-bis-acrylamide, diethylenetriamine-tris-methacrylamide, bis (methacrylamidopropoxy) ethane, beta-methacrylamidoethyl methacrylate, N [(beta-hydroxyethoxy) ethyl] - acrylamide.



  Suitable unsaturated polyesters and polyamides are derived e.g. on maleic acid and diols or diamines. Maleic acid can be partially replaced by other dicarboxylic acids. They can be used together with ethylenically unsaturated comonomers, e.g. Styrene. The polyesters and polyamides can also be derived from dicarboxylic acids and ethylenically unsaturated diols or diamines, especially from long-chain ones with e.g. 6 to 20 carbon atoms. Examples of polyurethanes are those which are composed of saturated or unsaturated diisocyanates and unsaturated or saturated diols.



  Polybutadiene and polyisoprene and copolymers thereof are known. Suitable comonomers are e.g. Olefins such as ethylene, propene, butene, hexene, (meth) acrylates, acrylonitrile, styrene or vinyl chloride. Polymers with (meth) acrylate groups in the side chain are also known. For example, are reaction products of novolak-based epoxy resins with (meth) -acrylic acid, homo- or copolymers of vinyl alcohol or their hydroxyalkyl derivatives which are esterified with (meth) -acrylic acid, or homo- and copolymers of (meth) -acrylates with Hydroxyalkyl (meth) acrylates are esterified.



  The photopolymerizable compounds can be used alone or in any mixtures. Mixtures of polyol (meth) acrylates are preferably used.



  Component (b) is a compound which is an acid or which carries an acidic group or is bound as a ligand or counterion and which performs specific functions which are important for the end properties in the formulation.



  These are all organic and inorganic Bronsted acids such as Carbonic acid, sulfuric acid, sulfonic acid, phosphorous acid, phosphoric acid, poly- and metaphosphoric acid, nitrous acid and nitric acid, acetic acid, oxalic acid, amino acids etc., as well as derivatives of these acids, which are still acidic in character. The compounds with acidic groups are organic or inorganic molecules to which derivatives of the Brönsted acids mentioned above are bound.



  These can be monomers, e.g. Acrylic acid and methacrylic acid, maleic acid, fumaric acid; Phthalic acid and its anhydrides, but also unsaturated fatty acids such as linolenic acid or acidic acid. Furthermore, oligomers and polymers with acidic groups are meant, which can be both unsaturated and saturated and either participate in the polymerization reaction or are used as film-forming binders. The poly- and oligomers can be simply substituted, which is often achieved by termination with an acid-containing termination reagent, but can also be substituted several times, which is achieved by copolymerization of acid-modified monomers with unmodified monomers.

   Another possibility for introducing acid groups into an oligomer or polymer is the polymer-analogous reaction with acid-functionalized reagents. The acid-modified oligomers and polymers are, in particular, polyesters, polyacrylates, polyamides, polyurethanes, polyols, polyethers modified with carboxylic acid and sulfonic acid , Polyepoxides, alkyd resins, polybutadienes, polyisoprenes, polystyrenes, polyimides, cellulose, cellulose esters, chlorinated polyolefins, polyvinyl butyral, polyallyl ethers, polyvinyl ethers, polycarbonates, polyacrylonitrile, polyisocyanates, melamine resins and the copolymers from the monomer units of the polymers listed.



  Other compounds with acid groups which are suitable as component (b) are dyes such as Methyl red hydrochloride, ethyl orange, methyl orange, acid yellow, rosolic acid, phenol red, fluorescein, rose bengal, thymolphthalein monophosphoric acid, auramine o, cresyl violet, rhodamine b, brilliant green or variant blue. Component (b) can also consist of pigments, fillers or other inorganic auxiliaries (such as filter aids, defoamers, matting agents, wetting agents, agents to increase scratch resistance or improve friction properties, anti-settling agents, emulsifiers, fungicides and biocides) with acidic groups. Examples of pigments with acidic groups are sulfonated and phosphated phtahlocyanines, diketopyrrolopyrroles such as e.g. Irgazin DPP Rot BL, indanthrones such as

   Irgazin Blau A3RN and Chinakridone such as Chinquasia Red Y859. The fillers and auxiliaries include, for example, acidic silica gels, BaSO4, CaSO4, bleaching earths (e.g. Prolit, Tonsil Optimum), diatomaceous earth, silicic acid, kaolins, silicon dioxide, bentonites, aluminum triphosphate, etc. ) in question. Examples include phosphates and sulfates. Organic corrosion protection agents based on carboxylic acids, such as Irgacor 252, are also used. Component (b) also includes substances that change the rheological properties of the formulation, including thickeners and flow aids.

   Acidic organic polymers are usually used, as described above, but now branched and crosslinked polymers are also used as thickeners. Spherical polymers, e.g. Microgels, on the other hand, are used as flow improvers in the formulation. Modified fillers or pigments are also used for this purpose and examples include aerosils and silicas.



  Binders can also be added to the compositions according to the invention, which is particularly expedient if the photopolymerizable compounds are liquid or viscous substances. The amount of binder can e.g. 5-95, preferably 10-90 and particularly 40-90 wt .-%, based on the total solids. The choice of binder depends on the field of application and the properties required for this, such as developability in aqueous and organic solvent systems, adhesion to substrates and sensitivity to oxygen.



  Suitable binders are e.g. Polymers with a molecular weight of about 5000-2,000,000, preferably 10,000-1,000,000. Examples are: homo- and copolymers acrylates and methacrylates, e.g. Copolymers of methyl methacrylate / ethyl acrylate / methacrylic acid, poly (methacrylic acid alkyl ester), poly (acrylic acid alkyl ester); Cellulose esters and ethers such as cellulose acetate, cellulose acetate butyrate, methyl cellulose, ethyl cellulose; Polyvinyl butyral, polyvinyl formal, cyclized rubber, polyethers such as polyethylene oxide, polypropylene oxide, polytetrahydrofuran;

   Polystyrene, polycarbonate, polyurethane, chlorinated polyolefins, polyvinyl chloride, copolymers of vinyl chloride / vinylidene chloride, copolymers of vinylidene chloride with acrylonitrile, methyl methacrylate and vinyl acetate, polyvinyl acetate, copoly (ethylene / vinyl acetate), polymers such as polycaprolactam and poly (hexamethylene adipamide), polyesters such as poly (ethylene glycol) ) and poly (hexamethylene glycol succinate).



  The unsaturated compounds can also be used in a mixture with non-photopolymerizable film-forming components. These can e.g. physically drying polymers or their solutions in organic solvents, e.g. Nitrocellulose or cellulose acetobutyrate. However, these can also be chemically or thermally curable resins, such as Polyisocyanates, polyepoxides or melamine resins. The use of thermally curable resins is important for use in so-called hybrid systems, which are photopolymerized in a first stage and crosslinked by thermal aftertreatment in a second stage.



  Compositions are preferred in which the coinitiator (d) is a dye or a UV absorber.



  Compositions with cyanine, merocyanine, anthraquinone, azo, diazo, acridine, coumarin, phenazine, phenoxazine, phenothiazine, rhodamine, xanthone, triphenylmethane or xanthene derivative as the dye are particularly preferred.



  Particularly preferred are cyanines of the formula IV, in which n = 1-4, Y = C (CH3) 2 or S and R = C1-C10-alkyl.



  Compositions in which the dye is cresyl violet, patent blue, brilliant blue, safranin O, fluorescein, rhodamine B, pyronine G4, azure A, lissamin green, ethyl orange or methylene blue are particularly preferred.



  Compositions in which the UV absorber is a thioxanthone derivative, a coumarin, benzophenone, a benzophenone derivative or a hexaarylbisimidazole derivative are also preferred.



  In addition to the photoinitiator (c), the photopolymerizable mixtures can contain various additives. Examples include thermal inhibitors that are designed to prevent premature polymerization, e.g. Hydroquinone, hydroquinone derivatives, p-methoxyphenol, beta-naphthol or sterically hindered phenols such as e.g. 2,6-di (tert-butyl) -p-cresol. To increase dark storage stability, e.g. Copper compounds such as copper naphthenate, stearate or octate, phosphorus compounds such as e.g. Triphenylphosphine, tributylphosphine, triethylphosphite, triphenylphosphite or tribenzylphosphite, quaternary ammonium compounds such as e.g. Tetramethylammonium chloride or trimethylbenzylammonium chloride, or hydroxylamine derivatives such as e.g. N-diethyl-hydroxylamine can be used.

   In order to exclude atmospheric oxygen during the polymerization, paraffin or similar wax-like substances can be added, which migrate to the surface at the beginning of the polymerization due to the lack of solubility in the polymer and form a transparent surface layer which prevents the entry of air. An oxygen-impermeable layer can also be applied. Small amounts of UV absorbers such as e.g. those of the hydroxyphenyl-benzotriazole, hydroxyphenyl-benzophenone, oxalic acid amide or hydroxyphenyl-s-triazine type, who added. Individual or mixtures of these compounds with or without the use of sterically hindered amines (HALS) can be used.



  Examples of such UV absorbers and light stabilizers are



  1. 2- (2 min -hydroxyphenyl) benzotriazoles, e.g. 2- (2 min -hydroxy-5 min -methylphenyl) -benzotriazole, 2- (3 min, 5 min -di-tert-butyl-2 min -hydroxyphenyl) -benzotriazole, 2- (5 min -tert-butyl-2 min -hydroxyphenyl) -benzotriazole, 2- (2 min -hydroxy-5 min - (1,1,3,3-tetramethylbutyl) phenyl) -benzotriazole, 2- (3 min, 5 min -Di-tert-butyl-2 min -hydroxyphenyl) -5-chloro-benzotriazole, 2- (3 min-tert-butyl-2 min -hydroxy-5 min -methylphenyl) -5-chlorobenzotriazole, 2- (3 min -sec-butyl-5 min -tert -butyl-2 min -hydroxyphenyl) -benzotrizole, 2- (2 min -hydroxy-4 min -octoxyphenyl) -benzotriazole, 2- (3 min, 5 min -Di-tert-amyl-2 min -hydroxyphenyl) -benzotriazole, 2- (3 min, 5 min -Bis- (alpha, alpha -dimethylbenzyl) -2 min -hydroxyphenyl) -benzotriazole, mixture of 2- (3 min-tert-butyl-2 min -hydroxy-5 min - (2- octyloxycarbonylethyl) phenyl) -5-chloro-benzotriazole,

   2- (3 min-tert-butyl-5 min - [2- (2-ethylhexyloxy) -carbonylethyl] -2 min -hydroxyphenyl) -5-chloro-benzotriazole, 2- (3 min-tert-butyl-2 min - hydroxy-5 min - (2-methoxycarbonylethyl) phenyl) -5-chloro-benzotriazole, 2- (3 min-tert-butyl-2 min -hydroxy-5 min - (2-methoxycarbonylethyl) phenyl) -benzotriazole, 2- ( 3 min-tert-butyl-2 min -hydroxy-5 min - (2-octyloxycarbonylethyl) phenyl) -benzotriazole, 2- (3 min-tert-butyl-5 min - [2- (2-ethylhexyloxy) carbonylethyl] -2 min -hydroxyphenyl) -benzotriazole, 2- (3 min -dodecyl-2 min -hydroxy-5 min -methylphenyl) -benzotriazole, and 2- (3 min -tert-butyl-2 min -hydroxy-5 min - (2- isooctyloxycarbonylethyl) phenyl-benzotriazole, 2.2 min -methylene-bis [4- (1,1,3,3-tetramethylbutyl) -6-benzotriazol-2-yl-phenol];

   Transesterification product of 2- [3 min-tert-butyl-5 min - (2-methoxycarbonylethyl) -2 min-hydroxy-phenyl] -benzotriazole with polyethylene glycol 300; [R-CH2CH2-COO (CH2) 3] 2- with R = 3 min-tert-butyl-4 min -hydroxy-5 min -2H-benzotriazol-2-yl-phenyl.



  2. 2-hydroxybenzophenones, e.g. the 4-hydroxy, 4-methoxy, 4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4.2 min, 4 min tri-hydroxy, 2 min hydroxy-4,4 min -dimethoxy derivative.



  3. Esters of optionally substituted benzoic acids, e.g. 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis- (4-tert-butylbenzoyl) resorcinol, benzoylresorcinol, 3,5-di-tert-butyl-4-hydroxybenzoic acid-2,4-di- tert-butylphenyl ester, 3,5-di-tert-butyl-4-hydroxybenzoic acid hexadecyl ester, 3,5-di-tert-butyl-4-hydroxybenzoic acid octadecyl ester, 3,5-di-tert-bel-4-hydroxybenzoic acid 2- methyl 4,6-di-tert-butylphenyl ester.



  4. Acrylates, e.g. alpha-cyano-beta, beta -diphenylacrylic acid ethyl ester or isooctyl ester, alpha-carbomethoxy-cinnamic acid methyl ester, alpha-cyano-beta-methyl-p-methoxy-cinnamic acid methyl ester or -butyl ester, alpha-carbomethoxy-p-methoxy-cinnamic acid- methyl ester, N- (beta-carbomethoxy-beta-cyanovinyl) -2-methyl-indoline.



  5. Sterically hindered amines, e.g. Bis (2,2,6,6-tetramethylpiperidyl) sebacate, bis (2,2,6,6-tetramethylpiperidyl) succinate, bis (1,2,2,6,6-pentamethylpiperidyl) ) sebacate, n-butyl-3,5-di-tert-butyl-4-hydroxybenzyl-malonic acid bis (1,2,2,6,6-pentamethylpiperidyl) ester, condensation product from 1-hydroxyethyl-2,2 , 6,6-tetramethyl-4-hydroxypiperidine and succinic acid, condensation product of N, N min-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylene diamine and 4-tert-octylamino-2,6- dichloro-1,3,5-s-triazine, tris (2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) - 1,2,3,4-butanetetraoate, 1.1 min - (1,2-ethanediyl) bis (3,3,5,5-tetramethyl-piperazinone), 4-benzoyl-2,2,6,6 -tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis- (1,2,2,6,6-pentamethylpiperidyl) -2-n-butyl-2- (2-hydroxy-3,5- di-tert-butylbenzyl) malonate, 3-n-octyl-7,7,9,

  9-tetramethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione, bis (1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate, bis (1-octyloxy2.2 , 6,6-tetramethylpiperidyl) succinate, condensation product of N, N min-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylene diamine and 4-morpholino-2,6-dichloro-1,3 , 5-triazine, condensation product of 2-chloro-4,6-di- (4-n-butylamino-2,2,6,6-tetramethylpiperidyl) -1,3,5-triazine and 1,2-bis- ( 3-aminopropylamino) ethane, condensation product of 2-chloro-4,6-di- (4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl) -1,3,5-triazine and 1,2- Bis- (3-aminopropylamino) ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] decane-2,4-dione, 3-dodecyl-1 - (2,2,6,6-tetramethyl-4-piperidyl) pyrrolidine-2,5-dione, 3-dodecyl-1- (1,2,2,6,6-pentamethyl-4-piperidyl) pyrrolidine 2,5-dione.



  6. oxalic acid diamides such as e.g. 4.4 min -di-octyloxy-oxanilide, 2.2 min -diethoxy-oxanilide, 2.2 min -di-octyloxy-5.5 min -di-tert-butyl-oxanilide, 2.2 min -di-dodecyloxy -5.5 min di-tert-butyl-oxanilide, 2-ethoxy-2 min -ethyloxanilide, N, N min-bis (3-dimethylaminopropyl) -oxalamide, 2-ethoxy-5-tert-butyl-2 min - ethyloxanilide and its mixture with 2-ethoxy-2 min -ethyl-5.4 min -di-tert-butyl-oxanilide, mixtures of o- and p-methoxy- and of o- and p-ethoxy-di-substituted oxanilides.



  7. 2- (2-hydroxyphenyl) -1,3,5-triazines, e.g. 2,4,6-tris (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy- 4-propyloxyphenyl) -6- (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4,6-bis (4-methylphenyl) -1,3, 5-triazine, 2- (2-hydroxy-4-dodecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy -3-butyloxypropyloxy) phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-octyloxypropyloxy ) phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-dodecyl / tridecyl-oxy- (2-hydroxypropyl) oxy-2-hydroxyphenyl] -4, 6-bis (2,4-dimethylphenyl) -1,3,5-triazine.



  8. Phosphites and phosphonites, e.g. Triphenyl phosphite, diphenylalkyl phosphite, phenyl dialkyl phosphite, tris (nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris (2,4-di-tert-butylphenyl) phosphite, diisithritol bisphitophosphite di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis-isodecyloxy-pentaerythritol diphosphite, bis- (2,4-di-tert-butyl-6-) methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis (2,4-di-tert-butylphenyl) -4.4 min -biphenylene- diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz [d, g] -1,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra -tert-butyl-12-methyl-dibenz [d, g] -1,3,2-dioxaphosphocin, bis (2,4-di-tert-butyl-6-methylphenyl) methylphosphite, bis- (2,

  4-di-tert-butyl-6-methylphenyl) ethyl phosphite.



  Amines can be added to accelerate the photopolymerization, e.g. Triethanolamine, N-methyl-diethanolamine, ethyl p-dimethylaminobenzoate or Michler's ketone. The effect of the amines can be enhanced by adding aromatic ketones of the benzophenone type. Amines which can be used as oxygen scavengers are, for example, substituted N, N-dialkylanilines, as described in EP-A-339 841. Further accelerators, coinitiators and autoxidizers are thiols, thioethers, disulfides or phosphines, as described in EP-A-438 123 and GB 2 180 358.



  The photopolymerization can also be accelerated by adding further photosensitizers which shift or broaden the spectral sensitivity. These are especially aromatic carbonyl compounds such as Benzophenone, thioxanthone, anthraquinone and 3-acylcoumarin derivatives as well as 3- (aroylmethylene) thiazolines, but also eosin, rhodanine and erythrosine dyes.



  The curing process can be supported, in particular, by compositions pigmented (e.g. with titanium dioxide), also by adding a component which forms free radicals under thermal conditions, e.g. an azo compound such as 2.2 min azobis (4-methoxy-2,4-dimethylvaleronitrile), a triazene, diazosulfide, pentazadiene or a peroxy compound such as hydroperoxide or peroxycarbonate, e.g. t-butyl hydroperoxide, e.g. described in EP-A 245 639.



  Other common additives are - depending on the intended use - optical brighteners, fillers, pigments, dyes, wetting agents or leveling agents. For the hardening of thick and pigmented coatings, the addition of micro glass balls or powdered glass fibers, e.g. in US-A-5 013 768.



  The invention also relates to compositions comprising, as component (a), at least one ethylenically unsaturated photopolymerizable compound dissolved or emulsified in water.



  Such radiation-curable aqueous prepolymer dispersions are commercially available in many variations. This is understood to mean a dispersion of water and at least one prepolymer dispersed therein. The concentration of water in these systems is e.g. at 5 to 80, in particular 30 to 60 wt .-%. The radiation-curable prepolymer or prepolymer mixture is contained, for example, in concentrations of 95 to 20, in particular 70 to 40,% by weight. In these compositions, the sum of the percentages given for water and prepolymers is 100 in each case, and the auxiliaries and additives are added in different amounts, depending on the intended use.



  The radiation-curable, water-dispersed, and often also dissolved, film-forming prepolymers are mono-or polyfunctional ethylenically unsaturated prepolymers which are known per se and which can be initiated by free radicals for aqueous prepolymer dispersions and contain, for example, a content of 0.01 to 1.0 mol per 100 g prepolymer of polymerizable double bonds, and an average molecular weight of, for example have at least 400, in particular from 500 to 10,000. Depending on the application, prepolymers with higher molecular weights can also be used.

   For example, polymerizable CC double bonds containing polyesters with an acid number of at most 10, polymerizable CC double bonds containing polyethers, hydroxyl group-containing reaction products of a polyepoxide containing at least two epoxy groups per molecule with at least one alpha, beta-ethylenically unsaturated carboxylic acid, polyurethane (meth) Acrylates and alpha, beta-ethylenically unsaturated acrylic copolymers containing acrylic copolymers are used, as are described in EP-A-12 339. Mixtures of these prepolymers can also be used.

   Also suitable are the polymerizable prepolymers described in EP-A-33 896, which are thioether adducts of polymerizable prepolymers with an average molecular weight of at least 600, a carboxyl group content of 0.2 to 15% and a content of 0.01 to 0.8 moles of polymerizable CC double bonds per 100 g of prepolymer. Other suitable aqueous dispersions based on special (meth) acrylic acid alkyl ester polymers are described in EP-A-41 125; suitable water-dispersible, radiation-curable prepolymers made from urethane acrylates can be found in DE-A2 936 039.



  As further additives, these radiation-curable aqueous prepolymer dispersions can include dispersing aids, emulsifiers, antioxidants, light stabilizers, dyes, pigments, fillers, e.g. Talc, gypsum, silica, rutile, carbon black, zinc oxide, iron oxides, reaction accelerators, leveling agents, lubricants, wetting agents, thickeners, matting agents, defoamers and other auxiliaries customary in coating technology. Water-soluble high-molecular organic compounds with polar groups, such as e.g. Polyvinyl alcohols, polyvinyl pyrrolidone or cellulose ether in question. Non-ionic, optionally also ionic emulsifiers can be used as emulsifiers.



  The photopolymerizable compositions advantageously contain the photoinitiator (c) in an amount of 0.05 to 15% by weight, preferably 0.1 to 5% by weight, based on the composition.



  In certain cases it may be advantageous to use mixtures of two or more of the photoinitiators of the formula I according to the invention. Of course, mixtures with known photoinitiators can also be used, e.g. Mixtures with benzophenone, acetophenone derivatives, such as, for example, alpha-hydroxycycloalkylphenyl ketones, dialkoxyacetophenones, alpha-hydroxy- or alpha-aminoacetophenones, 4-aroyl-1,3-dioxolanes, benzoin alkyl ethers and benzil ketals, monoacylphosphinoxidenoxides, bisaconoxinoxenoxides.



  Examples of particularly suitable additional photoinitiators are: 1- (4-dodecylbenzoyl) -1-hydroxy-1-methylethane, 1- (4-isopropylbenzoyl) -1-hydroxy-1-methylethane, 1-benzoyl-1 - hydroxy-1-methylethane, 1- [4 (2-hydroxyethoxy) benzoyl] -1-hydroxy-1-methylethane, 1- [4 (acryloyloxyethoxy) benzoyl] -1-hydroxy-1-methylethane , Diphenyl ketone, phenyl-1-hydroxycyclohexyl ketone, (4-morpholinobenzoyl) -1-benzyl-1-dimethylamino-propane, 1- (3,4-dimethoxyphenyl) -2-benzyl-2-dimethylamino-butanone-1, (4- Methylthiobenzoyl) -1-methyl-1-morpholino-ethane, benzil dimethyl ketal, bis (cyclopentadienyl) bis (2,6-difluoro-3-pyrrylphenyl) titanium, cyclopentadienyl-arene-iron (II) complex salts, e.g.

   (eta <6> -isopropylbenzene) (eta <5> -cyclopentadien-yl) -iron-II-hexafluorophosphate, trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxy-benzoyl) - (2,4,4-trimethylpentyl) phosphine oxide, bis (2,4,6- trimethylbenzoyl) -2,4-dipentoxyphenylphosphine oxide or bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide. Further suitable additional photoinitiators can be found in US Pat. No. 4,950,581 column 20, line 35 to column 21, line 35.



  Triazine compounds, such as e.g. the triazines described in EP-A-1 37 452, DE-A-2 718 254 and DE-A-2 243 621. Further suitable triazines can be found in US Pat. No. 4,950,581, column 14, line 60 to column 18, line 44. Trihalomethyltriazines, e.g. 2,4-bis (trichloromethyl) -6 (4-styrene-phenyl) -s-triazine.



  If the photoinitiators (c) according to the invention are used in hybrid systems, in addition to the radical hardeners according to the invention, cationic photoinitiators such as e.g. Peroxide compounds, e.g. Benzoyl peroxide (other suitable peroxides are described in US Pat. No. 4,950,581, column 19, lines 17-25), aromatic sulfonium or iodonium salts, such as, for example, US Pat. No. 4,950,581 column 18, line 60 to column 19, Line 10, or cyclopentadienyl-arene-iron (II) complex salts, for example (eta <6> -isopropylbenzene) (eta <5> -cyclopentadien-yl) -iron-II-hexafluorophosphate, used.



  The invention therefore also relates to compositions which, in addition to the photoinitiator (c), also comprise at least one further photoinitiator (c min) and / or other additives.



  Of particular interest are those compositions containing, as additional photoinitiator (c min), a titanocene, a ferrocene, a benzophenone, a benzoin alkyl ether, a benzil ketal, a 4-aroyl-1,3-dioxolane, a dialkoxyacetophenone, an alpha-hydroxy or alpha Aminoacetophenone, an alpha-hydroxycycloalkyl phenyl ketone, a xanthone, a thioxanthone, an anthraquinone or a mono- or bisacylphosphine oxide or mixtures thereof.



  The photopolymerizable compositions can be used for various purposes, for example as a printing ink, as a clear lacquer, as a white lacquer, e.g. for wood or metal, as paint, etc. for paper, wood, metal or plastic, as daylight-curable coating for building and street marking, for photographic reproduction processes, for holographic recording materials, for image recording processes or for the production of printing plates that can be developed with organic solvents or aqueous-alkaline, for the production of masks for screen printing, as dental filling compounds, as adhesives, as pressure sensitive adhesives, as laminating resins, as etching or permanent resists and as solder masks for electronic circuits, for the production of three-dimensional objects by mass hardening (UV hardening in transparent forms)

   or by the stereolithography method, e.g. in US Pat. No. 4,575,330, for the production of composite materials (eg styrenic polyesters, which may optionally contain glass fibers and other auxiliaries) and other thick-layered masses, for coating or sealing electronic parts or as coatings for optical fibers .



  The compounds according to the invention can furthermore be used as initiators for emulsion polymerizations, as initiators of a polymerization for the fixing of order states of liquid-crystalline monomers and oligomers, as initiators for the fixing of dyes on organic materials.



  Mixtures of a prepolymer with polyunsaturated monomers, which also contain a monounsaturated monomer, are often used in paints. The prepolymer is primarily decisive for the properties of the lacquer film; through its variation, the person skilled in the art can influence the properties of the hardened film. The polyunsaturated monomer acts as a crosslinker, which makes the paint film insoluble. The monounsaturated monomer acts as a reactive diluent that lowers viscosity without the need to use a solvent.



  Unsaturated polyester resins are mostly used in two-component systems together with a monounsaturated monomer, preferably with styrene. Specific one-component systems are often used for photoresists, e.g. Polymaleimides, polychalkones or polyimides, as described in DE-OS 2 308 830.



  The compounds according to the invention and mixtures thereof can furthermore be used as radical photoinitiators or photoinitiating systems for radiation-curable powder coatings. The powder coatings can be based on solid resins and monomers containing reactive double bonds, e.g. Maleates, vinyl ethers, acrylates, acrylamides and mixtures thereof. A free-radically UV-curable powder coating can be prepared by mixing unsaturated polyester resins with solid acrylamides (for example methyl acrylamidoglycolate methyl ester) and a radical photoinitiator according to the invention, as described, for example, in the lecture "Radiation Curing of Powder Coating", Conference Proceedings, Radtech Europe 1993 by M. Wittig and Th. Gohmann described, can be formulated. The powder coatings can also contain binders, such as those e.g. in DE-A-4 228 514 and EP-A-636 669.

   Radically UV-curable powder coatings can also be formulated by mixing unsaturated polyester resins with solid acrylates, methacrylates or vinyl ethers and a photoinitiator (or photoinitiator mixture) according to the invention. The powder coatings can also contain binders, such as those e.g. in DE-A-4 228 514 and EP-A-636 669. The UV-curable powder coatings can also contain white or colored pigments. For example, preferably rutile titanium dioxide can be used up to concentrations of 50% by weight in order to obtain a hardened powder coating with good covering properties. The method usually involves electrostatically or tribostatically spraying the powder onto the substrate, e.g.

   Metal or wood, melting the powder by heating and, after a smooth film has formed, radiation curing the coating with ultraviolet and / or visible light, e.g. with medium pressure mercury lamps, metal halide lamps or xenon lamps. A particular advantage of the radiation-curable powder coatings in comparison to the corresponding thermally curable ones is that the flow time after the powder particles have melted can optionally be delayed to ensure the formation of a smooth, high-gloss coating. In contrast to thermally curable systems, radiation-curable powder coatings can be formulated in such a way that they melt at lower temperatures without the undesirable effect of shortening the service life. For this reason, they are also suitable as coatings for heat-sensitive substrates, e.g.

   Wood or plastics.



  In addition to the photoinitiators according to the invention, the powder coating formulations can also contain UV absorbers. Corresponding examples are given above under items 1-8. listed.



  The photocurable compositions according to the invention are suitable e.g. as coating materials for all types of substrates, e.g. Wood, textiles, paper, ceramics, glass, plastics such as polyester, polyethylene terephthalate, polyolefins or cellulose acetate, in particular in the form of films, and metals such as Al, Cu, Ni, Fe, Zn, Mg or Co and GaAs, Si or SiO2 to which a protective layer or an image is to be applied by image-wise exposure.



  The substrates can be coated by applying a liquid composition, a solution or suspension to the substrate. The choice of solvent and the concentration depend mainly on the type of composition and the coating process. The solvent should be inert, i.e. there should be no chemical reaction with the components and it should be possible to remove them again after drying after coating. Suitable solvents are e.g. Ketones, ethers and esters such as methyl ethyl ketone, isobutyl methyl ketone, cyclopentanone, cyclohexanone, N-methylpyrrolidone, dioxane, tetrahydrofuran, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 1,2-dimethoxyethane, ethyl acetate, acetic acid n-acetate -butyl ester and 3-ethoxy-propionic acid ethyl ester.



  The solution is applied uniformly to a substrate, e.g. by spinning, dipping, knife coating, curtain casting, brushing, spraying, especially by electrostatic spraying and reverse roll coating, and by electrophoretic deposition. It is also possible to place the light-sensitive layer on a temporary, flexible support and then to transfer the final substrate, e.g. a copper-clad printed circuit board.



  The application quantity (layer thickness) and type of substrate (layer carrier) depend on the desired application area. The layer thickness range generally comprises values from approx. 0.1 μm to more than 100 μm.



  The radiation-sensitive compositions according to the invention are used as negative resists which have a very high sensitivity to light and can be developed in an aqueous alkaline medium. They are suitable as photoresists for electronics (galvanoresist, etching resist, solder resist), the production of printing plates such as offset printing plates or screen printing forms, the use in molded part etching or the use as micro-resist in the production of integrated circuits. The possible layer supports and the processing conditions of the coated substrates are correspondingly different.



  The compounds according to the invention are also used for the production of single- or multi-layer materials for image recording or image multiplication (copies, reprography), which can be single or multi-colored. Furthermore, these materials can also be used in color inspection systems. This technology can also be used in formulations containing microcapsules and a thermal step can follow the exposure step for imaging. Such systems and technologies and their application are e.g. in US 5,376,459.



  For photographic information records e.g. Foils made of polyester, cellulose acetate or paper coated with plastic; Specially treated aluminum for offset printing forms, copper-clad laminates for the production of printed circuits and silicon wafers for the production of integrated circuits. The layer thicknesses for photographic materials and offset printing forms are generally approximately 0.5 .mu.m to 10 .mu.m, for printed circuits 1 .mu.m to approximately 100 .mu.m.



  After the substrates have been coated, the solvent is generally removed by drying and a layer of the photoresist on the support results.



  The term “image-wise” exposure includes both exposure through a photomask that contains a predetermined pattern, for example a slide, exposure through a laser beam that is moved, for example, computer-controlled, over the surface of the coated substrate and in this way forms an image, and irradiation with computer-controlled electron beams.



  After the imagewise exposure of the material and before development, it can be advantageous to carry out a thermal treatment for a shorter time. Only the exposed parts are thermally hardened. The temperatures used are generally 50-150 ° C., preferably 80-130 ° C .; the time for the thermal treatment is usually between 0.25 and 10 minutes.



  The photocurable composition can also be used in a process for the production of printing forms or photoresists such as e.g. in DE-A-4 013 358 is used. In it, the composition is exposed to visible light of a wavelength of at least 400 nm without a mask for a short time before, simultaneously with or after the image-wise irradiation.



  After the exposure and, if appropriate, thermal treatment, the unexposed areas of the photoresist are removed in a manner known per se using a developer.



  As already mentioned, the compositions according to the invention can also be developed in an aqueous-alkaline manner. Suitable aqueous-alkaline developer solutions are, in particular, aqueous solutions of tetraalkylammonium hydroxides or of alkali metal silicates, phosphates, hydroxides and carbonates. Smaller amounts of wetting agents and / or organic solvents can optionally be added to these solutions. Typical organic solvents that can be added to the developer liquids in small amounts are, for example, cyclohexanone, 2-ethoxyethanol, toluene, acetone and mixtures of such solvents.



  Photocuring is of great importance for printing inks, since the drying time of the binder is a decisive factor for the production speed of graphic products and should be on the order of fractions of a second. UV-curable inks are particularly important for screen printing.



  As already mentioned above, the mixtures according to the invention are also very suitable for the production of printing plates. Here, e.g. Mixtures of soluble linear polyamides or styrene / butadiene or styrene / isoprene rubber, polyacrylates or polymethyl methacrylates with carboxyl groups, polyvinyl alcohols or urethane acrylates with photopolymerizable monomers, for example acrylic or methacrylamides or acrylic or methacrylic esters, and a photoinitiator. Films and plates from these systems (wet or dry) are exposed via the negative (or positive) of the artwork, and the uncured parts are then eluted with a suitable solvent.



  Another area of application for photocuring is metal coating, for example in the coating of sheets and tubes, cans or bottle closures, as well as photocuring on plastic coatings, for example floor or wall coverings based on PVC.



  Examples of the photocuring of paper coatings are the colorless coating of labels, record sleeves or book covers.



  It is also interesting to use the compounds according to the invention for curing molded parts made of composite materials. The composite mass consists of a self-supporting matrix material, e.g. a glass fiber fabric, or for example plant fibers [cf. K.-P. Mieck, T. Reussmann in Kunststoffe 85 (1995), 366-370], which is soaked in the light-curing formulation. Shaped parts made of composite materials produced with the connections according to the invention achieve high mechanical stability and resistance. The compounds according to the invention can also be used as photo hardeners in molding, impregnating and coating compositions, as are described, for example, in EP-A-7086.

   Such compositions are, for example, fine-layer resins, to which high demands are made with regard to curing activity and yellowing resistance, fiber-reinforced molding materials, such as flat, longitudinally or cross-corrugated light panels. Processes for the production of such molding materials, e.g. Hand lay-up processes, fiber spraying, spinning or winding processes are e.g. by P. H. Selden in "Glass fiber reinforced plastics", page 610, Springer Verlag Berlin-Heidelberg-New York 1967 described. Articles of daily use that can be manufactured using these processes are boats, chipboard or blockboard coated with glass fiber reinforced plastic on both sides, pipes, containers, etc. Further examples of molding, impregnating and coating compounds are UP resin fine layers for glass fiber-containing molding materials (GRP) , e.g. Corrugated sheets and paper laminates.

   Paper laminates can be based on urea or melamine resins. The fine layer is created on a carrier (e.g. a film) before the laminate is produced. The photocurable compositions according to the invention can also be used for casting resins or for embedding objects, e.g. of electronic parts, etc., are used. Medium pressure mercury lamps are used for curing, as are common in UV curing. However, less intense lamps are also of particular interest, e.g. type TL 40W / 03 or TL40W / 05. The intensity of these lamps corresponds approximately to that of sunlight. Direct sunlight can also be used for curing. Another advantage is that the composite can be removed and deformed from the light source in a hardened, plastic state. This is followed by complete curing.



  The compositions and compounds according to the invention can also be used for the production of optical waveguides and optical switches, the generation of a difference in the refractive index between exposed and unexposed areas being exploited.



  It is also important to use photocurable compositions for imaging processes and for the optical production of information carriers. As already described above, the layer (wet or dry) applied to the support is irradiated with a photomask with UV or visible light and the unexposed areas of the layer are removed by treatment with a solvent (= developer). The photocurable layer can also be applied to metal using the electrodeposition process. The exposed areas are cross-linked polymer and therefore insoluble and remain on the support. With appropriate coloring, visible images are created. If the carrier is a metallized layer, the metal can, after exposure and development, be etched away at the unexposed areas or reinforced by electroplating.

   In this way, printed electronic circuits and photoresists can be produced.



  The photosensitivity of the compositions according to the invention generally ranges from approx. 200 nm over the UV region to the infrared range (approx. 20,000 μm, in particular 1200 nm) and thus spans a very wide range. Suitable radiation contains e.g. Sunlight or light, from artificial light sources. A large number of different types are therefore used as light sources. Both point sources and flat spotlights (lamp carpets) are suitable.

   Examples are: carbon arc lamps, xenon arc lamps, medium-pressure, high-pressure and low-pressure mercury lamps, possibly doped with metal halides (metal halogen lamps), microwave-excited metal halide lamps, excimer lamps, superactinic fluorescent tubes, fluorescent lamps, argon incandescent lamps, photographic fluorescent lamps, electron flash lamps Floodlights, electron beams and X-rays, generated using synchrotrons or laser plasma. The distance between the lamp and the substrate to be exposed according to the invention can vary depending on the application and lamp type or intensity, e.g. between 2 cm to 150 cm. Laser light sources, e.g. Excimer lasers such as Krypton-F lasers for exposure at 248 nm. Lasers in the visible and infrared range can also be used.

   The high sensitivity of the materials according to the invention is very advantageous here. This method can be used to produce printed circuits in the electronics industry, lithographic offset printing plates or relief printing plates and photographic image recording materials.



  The invention therefore also relates to a process for the photopolymerization of non-volatile monomeric, oligomeric or polymeric compounds having at least one ethylenically unsaturated double bond and at least one compound containing an acidic group, the acidic group also being able to be present in the ethylenically unsaturated compound, characterized in that that at least one compound of the formula I according to claim 1, in which G represents a dye residue or UV absorber residue, or at least one compound of the formula I according to claim 1 in combination with at least one coinitiator, is added to the above-mentioned compounds and with light out the infrared range is irradiated over the UV range up to the wavelength of 200 nm,

   and the use of a composition as described above for the production of pigmented and non-pigmented paints, powder coatings, printing inks, printing plates, adhesives, dental materials, optical fibers and optical switches, color testing systems, glass fiber cable coatings, screen printing stencils, resist materials, in photographic reproduction processes, for encapsulating electrical and electronic components , for the production of composite materials, for the production of magnetic recording materials, for the production of three-dimensional objects by means of stereolithography, and as an image recording material, in particular for holographic recordings.



  The invention also relates to a coated substrate which is coated on at least one surface with a composition as described above, and to a process for the photographic production of relief images, in which a coated substrate is exposed imagewise and then the unexposed portions are removed with a solvent . Of particular interest here is the exposure - already mentioned above - using a laser beam.



  The compounds of the formula I according to the invention are white powders which are stable in air. As already mentioned above, the compounds are characterized in that the sum of the Hammett sigma constants (SIGMA sigma) of the substituents on the aromatic radicals in R2, R3 and R4 is between + 0.36 and + 2.58. These compounds are acid stable and can be used as photo hardeners in acidic photopolymerizable formulations.



  The borate compounds according to the invention can be used not only as initiators for photopolymerization reactions, but also as thermal polymerization initiators.



  The invention therefore also relates to the use of the compounds of the formula I as an initiator for the thermal polymerization of compounds with ethylenically unsaturated double bonds, and to a process for the thermal polymerization of compounds with ethylenically unsaturated double bonds, characterized in that at least one compound of the formula is used as the polymerization initiator I is used.



  The following examples further illustrate the invention. As in the rest of the description and in the claims, details in parts or percentages relate to the weight, unless stated otherwise.



  If no special isomers are specified in the designation of alkyl radicals with more than three carbon atoms, they are in each case the n-isomers.


 Example 1: Method A: Working procedure for the production of borates from triorganylboranes
 


 Tetramethylammonium butyl tris (2,6-difluorophenyl) borate
 



  1.0 equivalents of butyllithium (0.012 mol) in hexane are added to a solution of 5.0 g (0.012 mol) of tris (2,6-difluorophenyl) borane in 20 ml of tetrahydrofuran (THF) at 0 ° C. so that the temperature 5 DEG C does not exceed. The reaction mixture is allowed to warm to room temperature and stirred for 0.5 h. The mixture is then concentrated in vacuo and the oily residue is dissolved in 80 ml of a 4: 1 mixture of methanol and water. After filtering off and treating the filtrate with 3.95 g (0.036 mol) of tetramethylammonium chloride, a white solid precipitates. This is filtered off, washed with water and dried in vacuo. 3.3 g (57% of theory) of the borate with a melting point of> 230 ° C. are obtained.

   The shift value delta in <1> <1> B NMR spectrum in CD3COCD3 is -13.21 ppm.


 Example 2: Method B: Working procedure for the production of borates from alkyldihaloboranes
 


 Tetramethylammonium hexyl tris (p-chlorophenyl) borate
 



  A small part of a solution of 5.8 g (0.03 mol) of 1-bromo-4-chlorobenzene in 30 ml of THF is added to a suspension of 0.73 g (0.03 mol) of magnesium shavings in 10 ml of THF. The reaction mixture is heated until the Grignard reaction starts. At the start of the reaction, the heating is stopped and the remaining 1-bromo-4-chlorobenzene solution is added dropwise over 20 min so that a slight reflux is maintained. After the addition, the mixture is heated until the remaining magnesium is used up. In another reaction vessel, 10 ml of THF are slowly added to 3.2 g (0.01 mol) of hexyldibromoborane dimethyl sulfide cooled to 0 ° C. The Grignard solution is then added dropwise at the same temperature for 30 minutes and, after the addition is complete, heated under reflux for 2 hours.

   The mixture is then concentrated in vacuo and the resulting oily residue is dissolved in 80 ml of a 4: 1 mixture of methanol and water. After filtering off and treating the filtrate with 3.3 g (0.03 mol) of tetramethylammonium chloride, a white solid precipitates. This is filtered off, washed with water and dried in vacuo. 2.8 g of the borate are obtained. Recrystallization from methanol gives 1.75 g (35% of theory) of pure borate with a melting point of 154-156 ° C. The shift value delta im <1> <1> B NMR spectrum in CD3COCD3 is -9.87 ppm.


 Example 3: Method C Preparation of hexyl tris (3-trifluoromethylphenyl) borate
 



  For a solution of 3.38 g (0.015 mol) of 1-bromo-3-trifluoromethylbenzene in 15 ml of Diethyie, that number of stages is given at which a hardened line can still be seen. The dyes and results used are listed in Table 9.
 <tb> <TABLE> Columns = 3 Table 9
 <tb> Head Col 1: dye
 <tb> Head Col 2: Number of stages shown
 <tb> Head Col 3: bleaching behavior *
 <tb> <SEP> cyanine <SEP> 4 (SEP) <-> (TB> <SEP> Safranin O <SEP> 13 <CEL AL = L> -
 <tb> <CEL AL = L> Rhodamine B <SEP> 12 (SEP) <-> (TB> <SEP> pyronine GY <SEP> 12 <SEP> b
 <tb> <SEP> Methylene blue <CEL AL = L> 7 <CEL AL = L> b
 <tb> </TABLE>
EMI60.1
 
 



  * b = bleaches (visual inspection)
 - = fading is not observed, but this does not exclude that it does not occur,
 it just means that it is not noticed during the visual inspection


 Example 59
 



  A photocurable formulation is made by mixing the following components:
 <tb> <TABLE> Columns = 2
 <tb> <SEP> 10.0 g <SEP> dipentaerythritol monohydroxy pentaacrylate, <TM> SR 399, Sartomer Co., Berkshire, GB
 <tb> <CEL AL = L> 15.0 g <SEP> tripropylene glycol diacrylate, Sartomer Co., Berkshire, GB
 <tb> <SEP> 15.0 g <SEP> N-vinyl pyrrolidone, Fluka
 <tb> <SEP> 10.0 g <SEP> trimethylolpropane triacrylate, Degussa
 <tb> <SEP> 50.0 g <SEP> urethane acrylate <TM> Actylan AJ20, Société National des Poudres et Explosifs
 <tb> <SEP> 0.3 g <SEP> flow aid Byk 300, Byk-Mallinckrodt
 <tb> </TABLE>



  Portions of this composition are mixed with 0.4%, based on the total amount of the formulation, of compound 5, and 0.3% of a dye. All operations are carried out under red light. The formulations are applied to a 300 μm aluminum foil. The thickness of the dry layer is 60 µm. A 76 μm thick polyester film is applied to this film. The exposure is carried out by a frequency-doubled Nd / YAG laser (COHERENT DPSS 532-50, beam diameter 0.7 mm, divergence <1.3 mrad) with monochromatic light with a wavelength of 532 nm and a power of 50 mW. The laser beam with a diameter of approx. 3.3 mm is moved at a speed of 6 mm / s over a Stouffer wedge fixed to the sample with 21 steps.

   After the exposure, the films and the mask are removed and the exposed layer is developed in an ultrasound bath at 23 ° C. in ethanol for 10 seconds. Drying takes place at 40 ° C. for 5 minutes in a forced air oven. After development, a line of different widths and lengths remains. For the evaluation, the number of stages is indicated at which a hardened line can still be seen. The dyes and results used are shown in Table 10:


 Table 10
 
EMI61.1
 
 


 Example 60
 



  The same formulations as in Example 57 are used and portions of this composition are mixed with 0.4%, based on the total amount of the formulation, of compound 5 and 0.3% of a dye. All operations are carried out under red light. The samples are filled into pill jars approx. 3 cm in diameter. These formulations are used in the glasses with a frequency-doubled Nd / YAG laser (COHERENT DPSS 532-50, beam diameter 0.7 mm, divergence <1.3 mrad) with monochromatic light of wavelength 532 nm and a power of 50 mW at a distance of 30 cm for 10 seconds. After exposure, the uncured formulation is poured out and the remaining, hardened layer is developed in an ultrasound bath at 23 ° C. in ethanol for 10 seconds. Drying takes place at 40 ° C. for 5 minutes in a forced air oven.

   After development, a needle-like figure of different lengths remains. The length of the figure is given for evaluation and this is a measure of the hardening capacity. The dyes and results used are shown in Table 11:


 Table 11
 
EMI62.1
 
 


 Example 61
 



  The procedure is as in Example 50, but using 0.4% of the dye borate salts. In addition, instead of the xenon lamp, a frequency-doubled Nd / YAG laser (COHERENT DPSS 532-100, beam diameter 0.7 mm, divergence <1.3 mrad) with monochromatic light of the wavelength 532 nm and a power of 100 mW. The laser beam with a diameter of approx. 3.3 mm is moved at a speed of 6 mm / s over a Stouffer wedge fixed to the sample with 21 steps. After development, a line of different widths and lengths remains. For the evaluation, the number of stages is indicated at which a hardened line can still be seen. The dyes and results used are listed in Table 12.

   Table 12:
 <tb> <TABLE> Columns = 2 Table 12
 <tb> Head Col 1: connection
 <tb> Head Col 2: Number of stages shown
 <tb> <SEP> 21 <SEP> 9
 <tb> <SEP> 22 <SEP> 12
 <tb> </TABLE>


 Example 62
 



  The procedure is as in Example 60, but dye borate salts are used in such concentrations that the optical density of a layer of 2 mm for the wavelength of 532 nm is 0.5, and compound 5 is additionally used. In contrast to Example 61, a frequency-doubled Nd / YAG laser (COHERENT DPSS 532-100, beam diameter 0.7 mm, divergence <1.3 mrad) with monochromatic light of the wavelength 532 nm and a power of 100 mW and exposed at a distance of 30 cm for 5 seconds.

   The results are shown in Table 13.
 <tb> <TABLE> Columns = 3 Table 13
 <tb> Head Col 1: connection
 <tb> Head Col 2: Concentration compound 5
 <tb> Head Col 3: Length of the figure formed in mm
 <tb> <SEP> 0.05% 21 <SEP> 0 <SEP> 10
 <tb> <SEP> 0.05% 21 <CEL AL = L> 0.3% <CEL AL = L> 15
 <tb> <SEP> 0.05% 21 <SEP> 0.6% <SEP> 15
 <tb> <SEP> 0.03% 22 <SEP> 3
 <tb> <SEP> 0.03% 22 <CEL AL = L> 0.3% <SEP> 8
 <tb> <SEP> 0.03% 22 <SEP> 0.6% <SEP> 11
 <tb> </TABLE>


 Example 63
 



  The same formulations as in Example 59 are used and portions of this composition are mixed with 0.4%, based on the total amount of the formulation, of compound 5 and 0.3% of a dye. All operations are carried out under red light. The samples are filled into black plastic lids with a diameter of approx. 1.5 cm and a height of approx. 12 mm and covered with a Mylar film. These samples are taken with daylight and a dose of 1200 Mj / cm <2> exposed. After exposure, the uncured formulation is poured out and the remaining, hardened layer is developed in an ultrasound bath at 23 ° C. in ethanol for 1 minute. Drying takes place at 40 ° C. for 5 minutes in a forced air oven. For the evaluation, the thickness of the hardened layer is measured and this is a measure of the hardening capacity.

   The dyes and results used are shown in Table 14:
 <tb> <TABLE> Columns = 2 Table 14
 <tb> Head Col 1: dye
 <tb> Head Col 2: Thickness of the hardened layer in mm
 <tb> <SEP> Safranin O <SEP> 0.56
 <tb> <SEP> Methlene blue <CEL AL = L> 1.15
 <tb> </TABLE>


 Example 64
 



  The procedure is as in Example 63, but instead of mixtures of borates and dyes, 0.4% of the dye borate salts according to the invention are used and only a dose of 200 mJ / cm <2> used. The results are shown in Table 15:
 <tb> <TABLE> Columns = 2 Table 15
 <tb> Head Col 1: connection
 <tb> Head Col 2: Thickness of the hardened layer in µm
 <tb> <SEP> 20 <SEP> 395
 <tb> <SEP> 21 <SEP> 48
 <tb> <CEL AL = L> 22 <CEL AL = L> 135
 <tb> </TABLE>


 Example 65
 



  The procedure is as in Example 46, except that 1.7% of a radical photoinitiator is added together with 0.4% of compound 5 and 0.3% Quantacure ITX. However, an iron-doped mercury lamp is used for the exposure, and exposure is carried out for 40 seconds at a distance of 30 cm. The results are described in Table 16.


 Table 16
 
EMI65.1
 
 


 Example 66
 



  The procedure is as in Example 46, but 0.1% of a cationic photoinitiator is added together with 0.4% of compound 5. The results are described in Table 17.


 Table 17
 
EMI65.2
 
 
EMI66.1
 
 


 Example 67
 



  The procedure is as in Example 46, but 0.4% of a cationic photoinitiator is added together with 0.4% of compound 5 and 0.3% of a dye. The results are described in Table 18.


 Table 18
 
EMI66.2
 
 
EMI67.1
 
 


 Example 68
 



  0.45 compound 5 and 0.3% of a dye are mixed into 20 g of Palatal P 5-01 (BASF). The samples are filled into black plastic lids with a diameter of approx. 1.5 cm and a height of approx. 12 mm and covered with a Mylar film. These samples are exposed with fluorescent lamps (Philips TL03 40 W) at a distance of 10 cm for 6 minutes. After exposure, the uncured formulation is poured out and the remaining, hardened layer is dried. For the evaluation, the thickness of the hardened layer is measured and this is a measure of the hardening capacity. The dyes and results used are shown in Table 19.


 Table 19
 
EMI68.1
 
 


 Example 69
 



  * The procedure is as in Example 59, but 0.4% of compound 5 and 0.3% of an electron acceptor and 0.3% of a dye are added in each case. However, the exposure takes place with a xenon lamp at a distance of 30 cm for 20 seconds. The results are described in Table 20.
 <tb> <TABLE> Columns = 3 Table 20
 <tb> Head Col 1: electron acceptor
 <tb> Head Col 2: dye
 <tb> Head Col 3: Number of hardened stages
 <tb> <SEP> Quantacure ITX <SEP> Safranin O <SEP> 10
 <tb> </TABLE>


 Example 70
 



  The procedure is as in Example 69, but 0.3% of dye borate salts according to the invention and 0.3% of a dye are added in each case. The results are described in Table 21


 Table 21
 



  .
EMI69.1
 



    

Claims (14)

  1. Compounds of formula (I) EMI70.1          wherein  R1 is C1-C20-alkyl, C3-C12-cycloalkyl, C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl, the radicals being C1-C20-alkyl, C3-C12-cycloalkyl , C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl can be interrupted with one or more groups O, S (O) p or NR5 or where the residues C1-C20-alkyl, C3 -C12-Cycloalkyl, C2-C8-alkenyl, phenyl-C1-C6-alkyl or naphthyl-C1-C3-alkyl unsubstituted or with C1-C12-alkyl, OR6, R7S (O) p, R7S (O) 2O, NR8R9 , SiR10R11R12, BR13R14 or R15R16P (O) q, are substituted;  R2, R3 and R4 independently of one another are phenyl or biphenyl, the radicals phenyl or biphenyl being unsubstituted or with C1-C12-alkyl which is unsubstituted or substituted by OR6, NR8R9 or halogen, OR6, R7S (O) p, R7S (O) 2O, R8R9NS (O) 2, NR8R9, NR8R9CO, EMI70.2       SiR10R11R12, BR13R14, halogen, R15R16P (O) q, EMI70.3       or EMI70.4  are substituted;  characterized in that the sum of the Hammett sigma constants (SIGMA sigma) of the substituents on the aromatic radicals R2, R3 and R4 is between +0.36 and +2.58;    X represents O, S or NR21;  R5 is hydrogen, C1-C12-alkyl, unsubstituted or mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- or pentasubstituted by C1-C6-alkyl , C1-C12 alkoxy or halogen substituted phenyl;  R6 and R7 unsubstituted or halogen-substituted C1-C12-alkyl, unsubstituted or mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentavalent C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl;  R8, R9, R10, R11, R12, R13, R14, R15 and R16 independently of one another C1-C12-alkyl, C3-C12-cycloalkyl, unsubstituted or one to five times with C1-C6-alkyl, C1-C12-alkoxy or Halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentas with C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl, or R8 and R9 together with the N atom to which they are attached form a 6-membered aliphatic ring which may also contain oxygen or sulfur as a further heteroatom;  R17, R18, R19 and R20 independently of one another are hydrogen, unsubstituted or C1-C12-alkoxy-substituted C1-C12-alkyl, phenyl or phenyl-C1-C6-alkyl, the radicals phenyl or phenyl-C1-C6-alkyl being unsubstituted or substituted one to five times with C1-C6-alkyl, C1-C12-alkoxy or halogen;  p represents a number from 0 to 2;  r represents a number from 0 to 5;  R21 represents hydrogen or C1-C12-alkyl;  R22, R22a, R23 and R24 independently of one another are hydrogen, unsubstituted or C1-C12-alkoxy, OH or halogen-substituted C1-C12-alkyl or unsubstituted or C1-C12-alkoxy, OH or halogen-substituted phenyl;  q represents 0 or 1; and  G represents a residue which can form positive ions. 2nd  Compounds of formula I according to claim 1, wherein R1 is C1-C6-alkyl, R2, R3 and R4 are the same and phenyl, which with phenoxy, R8R9NS (O) 2, NR8R9CO, EMI71.1  , Fluorine, bromine, chlorine, with halogen-substituted C1-C4-alkyl or EMI72.1  is substituted mean; R8 and R9 are C1-C4 alkyl; R21 represents C1-C4-alkyl; r represents the number 3; and G ammonium, trimethylammonium, tetramethylammonium, tetrabutylammonium, tetradecylammonium, trimethyl-n-cetylammonium, cetylpyridinium, methyl-2-chloropyridinium, trimethyl-hydroxymethylammonium, triethyl-3-bromopropylammonium, ciphenylhenyliononium, triphenylphenylsulfonium, blue-triphenylsulfonium-ionium, triphenylsulfonium-ionium, triphenylphenylsulfonium , Safranin O-cation, 3,4-dimethyl-2- (2-hydroxy-3-trimethylaminopropoxy) thioxanthone cation, (CH3) 3N <+> (CH2) 6N <+> (CH3) 3,   EMI72.2  , EMI72.3  , (Phenyl) 3P = N <+> = P (phenyl) 3, EMI72.4     EMI72.5     EMI72.6       is. 3rd  Containing composition    (a) at least one ethylenically unsaturated compound    (b) at least one compound containing an acidic group,    component (a) may also contain the acidic group,    (c) at least one photoinitiator of the formula (I); and    (d) optionally at least one coinitiator. 4. Composition according to claim 3, characterized in that it contains, in addition to the photoinitiator (c), at least one further photoinitiator (c min) and / or other additives. 5. The composition according to claim 3, comprising in addition to components (a) - (c) at least one neutral, anionic or cationic dye (d) and an onium compound (d min). 6. The composition according to claim 5, additionally containing a radical photoinitiator, in particular an alpha-aminoketone compound. 7.  Composition according to Claim 3, comprising, in addition to components (a) - (c), at least one compound of the formula XI EMI73.1          wherein Ra, Rb, Rc and Rd independently of one another for C1-C12-alkyl, trimethylsilylmethyl, phenyl, another aromatic hydrocarbon, C1-C6-alkylphenyl, allyl, phenyl-C1-C6-alkyl, C2-C8-alkenyl, C2- C8-alkynyl, C3-C12-cycloalkyl or saturated or unsaturated heterocyclic radicals, where the radicals are phenyl, other aromatic hydrocarbon, phenyl-C1-C6-alkyl, and saturated or unsaturated heterocyclic radicals unsubstituted or with unsubstituted or with OR6, NR8R9 or Halogen substituted C1-C12 alkyl, OR6, R7S (O) p, R7S (O) 2O, R8R9NS (O) 2, NR8R9, NR8R9CO, SiR10R11R12, BR13R14, halogen or R15R16P (O) q are substituted;  R6 and R7 unsubstituted or halogen-substituted C1-C12-alkyl, unsubstituted or mono- to pentasubstituted by C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentavalent C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl;  R8, R9, R10, R11, R12, R13, R14, R15 and R16 independently of one another C1-C12-alkyl, C3-C12-cycloalkyl, unsubstituted or one to five times with C1-C6-alkyl, C1-C12-alkoxy or Halogen-substituted phenyl-C1-C6-alkyl or unsubstituted or mono- to pentas with C1-C6-alkyl, C1-C12-alkoxy or halogen-substituted phenyl, or R8 and R9 together with the N atom to which they are attached form a 6-membered aliphatic ring which may also contain oxygen or sulfur as a further heteroatom;  p represents a number from 0 to 2;  q represents 0 or 1; and  E represents a radical which can form positive ions, in particular alkali metals, ammonium or tetraalkylammonium. 8. The composition according to claim 3, containing at least one borate of the formula I as component (c) and at least one dye which changes or loses its color during or after the irradiation, which dye can also be a component of the compound of the formula I as a cation . 9. Composition according to one of claims 3-8, containing 0.05 to 15, in particular 0.2 to 5 wt .-% of component (c), based on the composition. 10th  Use of compounds of the formula I defined in claim 1 as photoinitiators for the photopolymerization of acidic compositions comprising at least one ethylenically unsaturated compound and at least one compound which contains an acidic group, the acidic group also being able to be present in the ethylenically unsaturated compound. 11.  Process for the photopolymerization of non-volatile monomeric, oligomeric or polymeric compounds having at least one ethylenically unsaturated double bond and at least one compound containing an acidic group, it being possible for the acidic group to also be present in the ethylenically unsaturated compound, characterized in that the compounds mentioned above at least one compound of the formula I according to claim 1, in which G represents a dye residue or UV absorber residue, or at least one compound of the formula I according to claim 1 in combination with at least one coinitiator (d), is added and with light from the infrared range above the UV range is irradiated up to the wavelength of 200 nm. 12th  Use of a composition according to any one of claims 3-9 for the production of pigmented and non-pigmented lacquers, powder coatings, printing inks, printing plates, adhesives, dental materials, optical fibers, optical switches, color testing systems, glass fiber cable coatings, screen printing stencils, resist materials, for encapsulating electrical and electronic components, for Production of composite materials, for the production of magnetic recording materials, for the production of three-dimensional objects by means of stereolithography, in photographic reproduction processes, and as image recording material, in particular for holographic recordings. 13. Coated substrate which is coated on at least one surface with a composition according to any one of claims 3-9. 14.  Use of the compounds of formula I as an initiator for the thermal polymerization of compounds having ethylenically unsaturated double bonds.