NO160214B - PHOTOPOLYMERIZABLE MASSES. - Google Patents

Description

The invention relates to photopolymerizable masses, so

as coating agents, varnishes and printing inks, where special acylphosphine oxide compounds are used as photoinitiators.

A number of photoinitiators are already known

the most diverse structures, for example aromatic ketones,

e.g. acetophenone- 09 benzophenone derivatives and benzyl ketals,

e.g. benzyl dimethyl ketal (BRD official publication 22 61 383), benzoin

ether (BRD official document 16 94 149), thioxanthones (BRD official document 20 03 132) etc. Photopolymerizable masses which are cured with this kind of initiator system, however, show an undesirable yellowing which makes the use of these systems on light (resp.

white) surfaces or as a cover on colored thread images unusable.

A further disadvantage is the often unsatisfactory storage stability of the fully sensitized resin mixtures, which, despite storage in the dark, are often only stable for a few days.

The photopolymerizable masses include acylphosphine oxide compounds of the general formula

where R* means a straight-chain or branched alkyl radical with 1-6 carbon atoms, a cyclohexyl-, cyclopentyl-, aryl-, halogen-, alkyl- or alkoxyl-substituted aryl-, an S- or N-containing 5- or 6-membered heterocyclic radical ;

7 112

R has the same meaning as R , whereby R and R can be the same or different or means an alkoc acid residue 1-6 carbon

atoms, an aryloxy or an arylalcolic acid residue, or R 1 and R 2 may be connected to each other to form a ring;

R means a straight-chain or branched alkyl radical with 2-18

carbon atoms, a cycloaliphatic residue containing 3-12 carbon atoms, an alkyl-, alkoxy- or thioalkyl-substituted phenyl or naphthyl residue, an S- or N-containing 5- or 6-membered heterocyclic residue, whereby the residues R<3 >optionally has additional functional groups, or means the grouping

1 2

where R and R have the above meaning and X means a phenylene residue or an aliphatic or cycloaliphatic divalent residue containing 2-6 carbon atoms;

1 3

and whereby optionally at least one of the residues R to R is olefinically unsaturated.

The products according to the invention include in particular such acylphosphine oxide compounds of the above-mentioned general formula where R<3> stands for an at least twice substituted phenyl, pyridyl, furyl or thienyl residue, which at least on the two carbon atoms that are neighbors to the attachment site with the carbonyl group carries the substituents A and B, which may be mutually the same or different, and which mean alkyl, alkoxy or alkylthio radicals with 1-6 carbon atoms, cycloalkyl radicals with 5-7 carbon atoms, phenyl radicals or halogen, preferably chlorine or bromine atoms, or R<3> means an α-naphthyl residue substituted at least in the 2,8-positions at A and B or a β-naphthyl residue substituted at least in the 1,3-positions at A and B.

With regard to the general formula (I) for the acylphosphine oxide compounds described, the following particulars must be stated:

R can be a straight-chain or branched alkyl residue with

1-6 C atoms, for example methyl, ethyl, i-propyl, n-propyl, n-butyl, amyl, n-hexyl,

cyclopentyl-, cyclohexyl-,

aryl, e.g. phenyl-, naphthyl-, halogen-substituted aryl, e.g. mono- or dichlorophenyl-,

alkyl-substituted phenyl-, e.g. methylphenyl-, ethylphenyl-, isopropylphenyl-, tert.-butylphenyl-, dimethylphenyl-, . alkoxy-substituted aryl-, e.g. methoxyphenyl-, ethoxyphenyl-, dwmethoxyphenyl-,

S- or N-containing 5- or 6-membered rings, e.g. thiophenyl-, pyridyl-.

1 2

In addition to the meaning of R, R can be an alkyl radical with

1-6 C atoms, e.g. methoxy-, ethoxy-, i-propoxy-,

butoxy-, ethyloxyethoxy-,

an aryloxy acid residue, e.g. phenoxy-, methylphenoxy-, an aryl-substituted carboxylic acid residue, e.g. benzyloxy-j

1 2

R can be connected with R to a ring, such as e.g. in acyl-phosphonic acid-o-phenylene esters.

R 3 can be an ethyl, i-propyl, n-propyl, n-butyl, 1-butyl, tert-butyl, i-amyl, n-hexyl, heptyl, n-octyl -, 2-ethylhexyl-, i-nonyl-, dimethylheptyl-, lauryl-, stearyl-, cyclopropyl-, cyclobutyl-, cyclopentyl-, i-methyl-cyclopentyl-, cyclohexyl-, 1-methylcyclohexyl-, norbornadienyl-, adamantyl-, dimethyloctyl-, dimethylnonyl-, dimethyl-decyl-, methylphenyl-, dimethylphenyl-, trimethylphenyl-, tert-butylphenyl-, isopropylphenyl-,

methoxyphenyl-, dimethoxyphenyl-, i-propoxyphenyl-, thio-methoxyphenyl-,

a- and p-naphthyl-, thiophenyl-, pyridyl-, (3-acetoxyethyl- or 3-carboxyethyl residue,

preferably a 2,6-dimethylphenyl-, 2,6-dimethoxyphenyl-, 2,6-dichlorophenyl-, 2,6-dibromophenyl-, 2-chloro-6-methoxy-

phenyl-, 2-chloro-6-methylthio-phenyl-, 2,4,6-trimethylphenyl-, 2,4,6-trimethoxyphenyl-, 2,3,4,6-tetramethylphenyl, 2,6-dimethyl-4- tert-butylphenyl-, 1,3-dimethylnaphthalene-2-, 2,8-dimethyl-naphthalene-1-, 1,3-dimethoxy-naphthalene-2-, 1,3-dichloronaphthalene-2-, 2,8- dimethoxynaphthalene-l-,

2,4,6-trimethylpyridine-3-, 2,4-dimethoxy-furan-3- or a 2,4,5-trimethylthiophene-3-residue.

12

R and R can also contain C-C double bonds such as

makes it possible to polymerize the photoinitiator into the binder.

Particularly preferred are aroyl-phenylphosphinic acid esters or aroyldiphenylphosphine oxides whose aroyl residue is in each case substituted in the o-styles by alkyl, alkoxy, halogen, alkylthio residues or mixtures thereof, e.g. 2,6-dimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl-phenyl-phosphinic acid methyl ester, 2,6-dichlorobenzoyl or 2,6-dimethoxybenzoyldiphenylphosphine oxide.

Preparation of such compounds is successful by reaction of acid halides of formula

where X = Cl, Br, with phosphines of formula

4

R = straight-chain or branched C1 to C8 alkyl or cycloalkyl radical with 5 or 6 C atoms.

The turnover can be carried out in a solvent such as e.g. a hydrocarbon or a hydrocarbon mixture, e.g. petroleum ether, toluene, cyclohexane, an ether, other common organic solvents, also apply without solvent at temperatures between -30°C and +130°C, preferably at 10-100°C. The product can be crystallized directly from the solvent, or it remains after evaporation or

distilled in vacuum.

Extraction of the acid halides

and the sub-

stituted phosphine R 1R 2 POR 4 takes place according to methods known to the person skilled in the art from the literature (e.g. Weygand-Hilgetag, Organisch-Chemisene Experimentierkunst, 4th edition,

pp. 246-256, J.A. Barth-Verlag, Leipzig 1970 as well as K. Sasse in Houben-Weyl, volume 12/1, pp. 208-209, G. Thieme-Verlaq, Stuttgart).

The method for producing the acylphosphine oxide compounds described here can be used e.g. describe as follows:

Suitable phosphines are e.g. methyl dimethoxyphosphine, butyl dimethoxyphosphine, phenyldimethoxyphosphine, tolyldimethoxyphosphine, phenyldiethoxyphosphine, tolyldiethoxyphosphine, phenyldiisopropoxyphosphine, tolyldiisopropoxyphosphine, phenyldibutoxyphosphine, toluyldibutoxyphosphine resp. dimethylmethoxyphosphine, dibutylmethoxyphosphine, dimethylbutoxyphosphine, diphenylmethoxyphosphine, diphenylethoxyphosphine, diphenylpropoxyphosphine, diphenyl-isopropoxyphosphine, diphenylbutoxyphosphine or similar starting materials leading to the compounds according to the invention.

Chlorides and bromides are suitable as acid halides, particularly acid chlorides.

Examples of the compounds according to the invention are in particular the following (without this being considered a limitation):

The compounds with structure according to the invention show very good reactivity as photoinitiators for photopolymerizable monomers with at least one C-C multiple bond and mixtures of such with each other and with known additives. The acylphosphine oxide compounds according to the invention are particularly suitable as photoinitiators in photopolymerizable masses for coatings and varnishes as well as marking materials. They are with regard to the yellowing of the lacquers produced in this way resp. coat the known photoinitiators (e.g. benzyl dimethyl ketal) far superior.

Preference is given in this connection to acylphenyl-phosphinic acid esters or acyldiphenylphosphine oxides, the acyl residue of which derives from a sec.- or tert.-substituted aliphatic carboxylic acid such as pivalic acid, 1-methylcyclohexanecarboxylic acid, norbornene carboxylic acid, α,α-dimethylalkanecarboxylic acid ("Versatic" acid with 9-13 carbon atoms), 2 -ethylhexanecarboxylic acid, or from a substituted aromatic carboxylic acid such as p-methyl-benzoic acid, o-methyl-benzoic acid, 2,4-dimethylbenzoic acid, p-tert-butylbenzoic acid, 2,4,5-trimethylbenzoic acid, p-methoxy-benzoic acid or p-thiomethylbenzoic acid.

In particular, the preferred o-disubstituted aroyl-diphenyl-phosphine oxides resp. aroyl-phenylphosphinic acid esters possess excellent storage stability at very high reactivity in photopolymerizable monomers. This applies above all to the most commonly used resins based on the styrene-containing unsaturated polyester as well as to the styrene-free acrylic acid esters. With the initiators according to the invention, white pigmented lacquers can also be cured without yellowing, but resins that are pigmented with color can also be processed. In these properties, they are superior to the known photoinitiators, e.g. benzyl dimethyl ketal or α-hydroxyisobutyrophenone.

Furthermore, it was surprisingly found that these advantages are maintained or even further enhanced if the preferred aroyldiphenylphosphine oxides are used in combination with known photoinitiators.

Particularly effective synergistic mixtures are obtained by combinations with known photoinitiators based on the aromatic ketones, especially benzyldimethylketal, o-hydroxyisobutyrophenone, diethoxyacetophenone, benzophenone and 2-methylthioxanthone, 2-isopropylthioxanthone as well as 2-chloro-thioxanthone. Here, by adding tertiary amines such as methyldiethanolamine, their well-known accelerating effect is also exploited. By combining the initiators according to the invention with e.g. benzyl dimethyl ketal seems to produce surprisingly active, highly storage-stable, amine-free, photopolymerizable masses which can optionally also be pigmented.

As photopolymerizable monomers, the usual compounds and substances with polymerizable C-C double bonds, which are activated by e.g. aryl, carbonyl, amino, amide, amido, ester, carboxyl or cyanide groups, halogen atoms or C-C double or C-C triple bonds. It can e.g. vinyl ethers and vinyl esters, styrene, vinyl toluene, acrylic acid and methacrylic acid as well as their esters with mono- and polyhydric alcohols, their nitriles or amides, maleic and furo esters as well as N-vinylpyrrolidone, N-vinyl-caprolactam, N-vinylcarbazole and allyl esters such as diallyl phthalate.

As polymerizable higher molecular compounds are e.g. the following suitable: unsaturated polyesters, produced from a,B-unsaturated dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid, optionally in a mixture with saturated resp. aromatic dicarboxylic acids, such as adipic acid, phthalic acid, tetrahydrophthalic acid or terephthalic acid, by reaction with alkanediols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol or oxalkylated bisphenol A; epoxy acrylates, prepared from acrylic or methacrylic acid and aromatic or aliphatic diglycidyl ethers and urethane acrylates (e.g. prepared from hydroxyalkyl acrylates and polyisocyanates), as well as polyester acrylates (e.g. prepared from hydroxyl group-containing saturated polyesters and acrylic or methacrylic acid) .

Optionally, the photopolymerizable coating agents, varnishes and printing inks can also be present or used as aqueous dispersions.

The photopolymerizable compounds, the composition of which for the purpose of application in question will be known to the person skilled in the art, can have saturated and/or unsaturated polymers added in a known manner as well as further additives such as inhibitors against thermal polymerization, paraffin, pigments, dyes, peroxides, various auxiliaries , fillers, matting agents and glass fibers as well as stabilizers against thermal or photochemical degradation.

Such mixtures are known to those skilled in the art,

and the type and quantity of the additives depends on the application in question1.

The compounds according to the invention are usually used in a concentration of 0.001-20%, in particular 0.01-15%, preferably 0.1-5%, calculated on the photopolymerizable mat. They can optionally be combined with accelerators, which have an inhibiting influence of the oxygen in the air on the photo-polymerization.

Such accelerators or synergists are e.g. secondary and/or tertiary amines, e.g. methyldiethanolamine, dimethylethanolamine, triethylamine, triethanolamine, p-dimethylamino-benzoic acid ethyl ester, benzyl-1-dimethylaraine, dimethylaminoethyl acrylate, K-phenylglycine, N-methyl-N-phenylglycine and analogs, which are compounds known to those skilled in the art. For acceleration of curing, further aliphatic and aromatic halides can serve, e.g. 2-chloromethyl-naphthalene, 1-chloro-2-chloromethyl-naphthalene, as well as radical generators such as peroxides and azo compounds.

As radiation sources for light which trigger polymerization of such mixtures, those which emit light are preferably used in the absorption range of the compounds according to the invention, i.e. between 230 and 450 nm. Particularly suitable are KvikksAlvr low-pressure jets, low-pressure and high-pressure jets, as well as (superactinic) fluorescent tubes or impulse jets.

The mentioned lamps may possibly be doped.

The parts and percentages given in the following examples mean weight, unless otherwise stated. Volume units relate to units such as liters to kg.

Example 1

To a mixture of 1350 parts by volume of petroleum ether (boiling range 40-70°C), 180 parts by volume of N,N-diethylaniline and 67 parts by volume of methanol are added while stirring at 0°C 225 parts of diphenylchlorophosphine, dissolved in 220 parts by volume of petroleum ether. The mixture is then stirred for a further 2 hours at room temperature. After cooling to approx. +5°C, the secreted amine hydrochloride is sucked off and the filtrate is first distilled at 10-20 Torr, to remove all low-boiling material. The diphenylmethoxyphosphine is then fractionally distilled at 0.1-1 Torr. Bp.Q 5 120-124°C. Yield: 175 parts (80% calculated on diphenylchlorophosphine).

To 36.2 parts of pivaloyl chloride, 64.8 parts of diphenylmethoxyphosphine are added dropwise while stirring at 30-60°C. After complete addition, this is left to react for a further 30 minutes, cooled to 0-10°C and the precipitated product is recrystallized from cyclohexane.

Yield: 69.5 parts pivaloyldiphenylphosphine oxide (81% of

the theory.

Temp. 110-112°C, HMR (CDCl3,<&>), 1.33 (S), 7.4-8.0 (M)

Example 2

To 77 parts of toluyl acid chloride, 108 parts of methoxydiphenylphosphine (prepared according to example 1) are added, dissolved in 200 parts by volume of toluene. It is then heated to 50°C for 60 minutes, cooled, the precipitate of toluyldiphenylphosphine oxide is suctioned off and recrystallized from cyclohexane. Yield: 117 parts (73% of theory), m.p. 105°C.

HMR (CDC13, <&>): 2.35 (S); 7.2-8 (m)

Example 3

Analogously to example 2, 134 parts of 2-methylbenzoyl-diphenylphosphine oxide are prepared from 77 parts of 2-methylbenzoic acid chloride and 108 parts of methoxydiphenylphosphine.

Yield: 84% of theory, m.p. 107°C.

NMR (CDCl 3 , δ): 2.5 (S); 7.2-8 (m); 8.8 (m)

Example 4

Analogously to example 1, 41.3 parts of p-tert-butyl-benzoic acid chloride are reacted with 45.4 parts of methoxydiphenylphosphine, dissolved in 20 parts of toluene, at 50°C for 90 minutes. After evaporation of the solvent on the rotary evaporator, it is recrystallized from cyclohexane.

Yield: 63 parts (83% of theory), m.p. 136°C.

NMR (CDCl 3 , b ): 1.3 (S); 7.3-8.1 (m); 8.5 (d)

Example 5

Analogous to example 2, 52 parts of terephthalic acid dichloride, dissolved in 200 parts of toluene, and 108 parts of methoxydiphenylphosphine produce 46 parts of terephthaloyl-bis-diphenylphosphine oxide (yield: 35% of theory), m.p. 205°C.

NMR (CDCl 3 , <&>): 6.8-8.2 (m)

Example 6

As indicated in example 2, 80 parts of 1-methyl-1-cyclohexanecarbonic acid chloride and 108 parts of methoxydiphenylphosphine without solvent produce 100 parts of 1-methyl-cyclohexylcarbonyl-diphenylphosphine oxide in the form of an oily crude product which is purified by chromatography and silica gel (eluent toluene).

Yield: 42 parts (26% of theory), m.p. 80°C

NMR (CDCl 3 , Å ): 1.4 (s); 1.1-1.6 (m); 2.1-2.4 (m); 7.3-8.0 (m)

Example 7

As indicated in example 1, 165 parts of 2-methyl-2-ethyl-hexanoyl-diphenylphosphine oxide are prepared from 88 parts of 2-methyl-2-ethylhexanoic acid chloride and 108 parts of methoxydiphenylphosphine in the form of an oily crude product. By column chromatography on silica gel (eluent: toluene/ether 3:1), the product is obtained in the form of a light yellow oil. Yield: 154 parts (90% of theory).

NMR (CDCl 3 , fe ): 1.2 (s); 0.5-2.2 (m); 7.3-8.1 (m)

Example 8

As stated in example 1, at 50°C 43.2 is added

parts of methoxydiphenylphosphine to 35.3 parts of 2,2-dimethylheptane-carbonic acid chloride ("Versatic" acid chloride). Stir for 3 hours at 50°C, cool to 15°C and stir the mixture into a slurry of 60 g of silica gel in 350 ml of toluene, stir for a further 1 hour under ice cooling. This is then suctioned off, and the solvent is distilled off under reduced pressure. "Versatoyl" diphenylphosphine oxide remains as a viscous oil.

Yield: 62 parts (90% of theory).

NMR (CDCl3,0): 0.4-2.3 (m); 7.2-8.1 (m)

Example 9

To a mixture of 600 parts by volume of petroleum ether, 263

parts of N,N-diethylaniline and 120 parts of isopropanol, 143 parts of phenyldichlorophosphine are dripped over the course of 1 hour at 0°C. The mixture is then stirred for a further 1 hour at room temperature, and then distilled after working up as described in example 1. The diiso-propoxyphenylphosphine distils at 68-72°C/0.3 mm. Out-

exchange: 126 parts (69% of theory).

158 parts of diisopropoxyphenylphosphine are added below

good stirring at 50-60°C slowly to 84 parts of pivalic acid chloride. The mixture is stirred for a further 2 hours and fractionated in a vacuum. Pivaloyl-phenylphosphinic acid isopropyl ester distills at 119-121°C/- 0.5 mm.

Yield: 112 parts (60% of theory).

Example 3

Analogously to example 2, 134 parts of 2-methylbenzoyl-diphenylphosphine oxide are prepared from 77 parts of 2-methyl-benzoic acid chloride and 108 parts of methoxydiphenylphosphine.

Yield: 84% of theory, m.p. 107°C.

NMR (CDCl 3 , S): 2.5 (S); 7.2-8 (m); 8.8 (m)

Example 4

Analogously to example 1, 41.3 parts of p-tert-butyl-benzoic acid chloride are reacted with 45.4 parts of methoxydiphenylphosphine, dissolved in 20 parts of toluene, at 50°C for 90 minutes. After evaporation of the solvent on the rotary evaporator, it is recrystallized from cyclohexane.

Yield: 63 parts (83% of theory), m.p. 136°C.

NMR (CDCl 3 , b ): 1.3 (S); 7.3-8.1 (m); 8.5 (d)

Example 5

Analogous to example 2, 52 parts of terephthalic acid dichloride, dissolved in 200 parts of toluene, and 108 parts of methoxydiphenylphosphine produce 46 parts of terephthaloyl-bis-diphenylphosphine oxide (yield: 35% of theory), m.p. 205°C.

NMR (CDCl 3 , <&>): 6.8-8.2 (m)

Example 6

As indicated in example 2, 100 parts of 1-methyl-cyclohexylcarbonyl-diphenylphosphine oxide are prepared from 80 parts of 1-methyl-1-cyclohexanecarbonic acid chloride and 108 parts of methoxydiphenylphosphine without solvent in the form of an oily crude product which is purified by chromatography and silica gel (eluent toluene).

Yield: 42 parts (26% of theory), m.p. 80°C

NMR (CDCl 3 , Å ): 1.4 (s); 1.1-1.6 (m); 2.1-2.4 (m); 7.3-8.0 (m)

Example 7

As stated in example 1, 165 parts of 2-raethyl-2-ethyl-hexanoyl-diphenylphosphine oxide are prepared from 88 parts of 2-methyl-2-ethylhexanoyl chloride and 108 parts of methoxydiphenylphosphine in the form of an oily crude product. By column chromatography on silica gel (eluent: toluene/ether 3:1), the product is obtained in the form of a light yellow oil. Yield: 154 parts (90% of theory).

NMR (CDCl 3 , k ): 1.2 (s); 0.5-2.2 (m); 7.3-8.1 (m)

Example 8

As stated in example 1, at 50°C 43.2 is added

parts of methoxydiphenylphosphine to 35.3 parts of 2,2-dimethylheptane-carbonic acid chloride ("Versatic" acid chloride). Stir for 3 hours at 50°C, cool to 15°C and stir the mixture into a slurry of 60 g of silica gel in 350 ml of toluene, stir for a further 1 hour under ice cooling. This is then suctioned off, and the solvent is distilled off under reduced pressure. "Versatoyl" diphenylphosphine oxide remains as a viscous oil.

Yield: 62 parts (90% of theory).

NMR (CDCl 3 , o ): 0.4-2.3 (m); 7.2-8.1 (m)

Example 9

To a mixture of 600 parts by volume of petroleum ether, 263

parts of N,N-diethylaniline and 120 parts of isopropanol, 143 parts of phenyldichlorophosphine are dripped over the course of 1 hour at 0°C. The mixture is then stirred for a further 1 hour at room temperature, and then distilled after working up as described in example 1. The diiso-propoxyphenylphosphine distils at 68-72°C/0.3 mm. Out-

exchange: 126 parts (69% of theory).

158 parts of diisopropoxyphenylphosphine are added below

good stirring at 50-60°C slowly to 84 parts of pivalic acid chloride. The mixture is stirred for a further 2 hours and fractionated in a vacuum. Pivaloyl-phenylphosphinic acid isopropyl ester distills at 119-121°C/- 0.5 mm.

Yield: 112 parts (60% of theory).

NMR (CDCl 3 , δ) 1.25 (S); 1.33 (h); 4.5 (m); 7.3-8 (m)

Example 10

To a mixture of 100 parts by volume of toluene, 421 parts by volume of N,N-diethylaniline and 100 parts by volume of methanol, 214 parts of phenyldichlorophosphine are added at 0°C. The mixture is then stirred for a further 1 hour at room temperature, the precipitate of amine hydrochloride is suctioned off and fractionated. The dimethoxyphenylphosphine distills at 46-50°C/0.2-0.3 mm.

Yield: 190 parts (93% of theory).

110.5 parts of dimethoxyphenylphosphine are added dropwise at 15°C to 78.7 parts of pivaloyl chloride. It is then heated for a further 30 minutes to 50°C and the reaction mixture is then distilled. Pivaloylphenylphosphinic acid methyl ester decomposes at 104-107<0>C/0.3 mm.

Yield: 101.3 parts (65% of theory). NMR (CDCl 3 , ): 1.3<»>

(S); 3.75 (d); 7.4-8 (m).

Example 11

To 163 parts of 2-ethylhexanoic acid chloride are added dropwise at 30°C 170 parts of dimethoxyphenylphosphine (Example 4). In connection with this, it is stirred for 50 minutes at 50°C and then fractionated in an oil vacuum.

2-Ethyl-hexanoyl-phenylphosphinic acid methyl ester converts at 160-168°C/1.2 mm.

Yield: 230 parts (81% of theory). NMR (CDCl 3 , &): 0.6-2

(m); 3.2 (q); 3.8 (d), 7.3-8 (m)

Example 12

To 155 parts of 4-methylbenzoyl chloride, dissolved in 250 parts by volume of toluene, 170 parts of dimethoxyphenylphosphine are added at 30°C. This is left to react for 60 minutes, cooled to 0°C and the precipitate sucked off. After recrystallization from cyclohexane, 4-methylbenzoyl-phenylphosphinic acid methyl ester melts at 99-101°C.

Yield: 180 parts (65% of theory). NMR: 2.25 (S); 3.7 (d);

7-8.1 (m)

Example 13

To a mixture of 1350 parts by volume of petroleum ether (boiling range 40-70°C), 180 parts by volume of N,N-diethylaniline and 67 parts by volume of methanol, 225 parts of diphentyl-chlorophosphine, dissolved in 220 parts by volume of petroleum ether, are added while stirring at 0°C. The mixture is then stirred for a further 2 hours at room temperature. After cooling to approx. +5°C, the secreted amine hydrochloride is suctioned off and the filtrate is first distilled at 10-20 Torr, to remove all low-boiling material. The diphenyloxyphosphine is then fractionally distilled at 0.1-1 Torr. Kp. Q 5 120-124°C. Yield: 175 parts (80% calculated on diphenylchlorophosphine).

In a stirring apparatus with reflux cooler and drip funnel, 638 parts of methoxydiphenylphosphine are slowly added to 547.5 parts of 2,4,6-trimethylbenzoyl chloride at 50-55°C. The mixture is stirred for a further 4-5 hours at 50°C, the contents of the flask are dissolved at 30°C in ether and petroleum ether is added until paleness begins. On cooling, 910 parts crystallize (87% of theory). 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. Melting point: 89-92 C, slightly yellow crystals.

Example 14

In an apparatus as described in example 13, 20 parts of 2,6-dimethoxybenzoyl chloride are suspended in 20 parts by volume of toluene, and 21.6 parts of methoxydiphenylphosphine are added dropwise to this mixture at 50-55°C with stirring. The mixture is stirred for a further 3 hours at 50°C and then recrystallized directly from toluene. 32 parts of yellowish crystals are obtained, mp: 124-126°C.

Example 15

In an apparatus as described in example 13, 91 parts of 2,4,6-trimethylbenzoyl chloride are charged. To this, 83 parts of triethyl phosphite are added at 60°C over the course of 15 minutes, and the mixture is stirred for a further 8 hours at 80°C. The contents of the flask are distilled at a reduced pressure of 0.4 mm, and the fraction at 120-122°C/0.4 mm is captured. 51 parts of 2,4,6-trimethylbenzoyl-phosphonic acid diethyl ester are obtained

(36% of theory) in the form of a slightly yellowish liquid.

NMR (CDCl 3 , i>) 1.25 (S); 1.33 (h) ; 4.5 (m) ; 7.3-8 (m)

Example 10

To a mixture of 1000 parts by volume of toluene, 421 parts by volume of N,N-diethylaniline and 100 parts by volume of methanol, 214 parts of phenyldichlorophosphine are added at 0°C. The mixture is then stirred for a further 1 hour at room temperature, the precipitate of amine hydrochloride is suctioned off and fractionated. The dimethoxyphenylphosphine distills at 46-50°C/0.2-0.3 mm.

Yield: 190 parts (93% of theory).

110.5 parts of dimethoxyphenylphosphine are added dropwise at 15°C to 78.7 parts of pivaloyl chloride. It is then heated for a further 30 minutes to 50°C and the reaction mixture is then distilled. Pivaloylphenylphosphinic acid methyl ester decomposes at l04-107°C/0.3 mm.

Yield: 101.3 parts (65% of theory). NMR (CDCl 3 , b ): 1.3<»>

(S); 3.75 (d); 7.4-8 (m).

Example 11

To 163 parts of 2-ethylhexanoic acid chloride are added dropwise at 30°C 170 parts of dimethoxyphenylphosphine (Example 4). In connection with this, it is stirred for 50 minutes at 50°C and then fractionated in an oil vacuum.

2-Ethyl-hexanoyl-phenylphosphinic acid methyl ester transitions at 160-168°C/1.2 mm.

Yield: 230 parts (81% of theory). NMR (CDCl 3 , &): 0.6-2

(m); 3.2 (q); 3.8 (d)» 7.3-8 (m)

Example 12

To 155 parts of 4-methylbenzoyl chloride, dissolved in 250 parts by volume of toluene, 170 parts of dimethoxy-phenylphosphine are added at 30°C. This is left to react for 60 minutes, cooled to 0°C and the precipitate sucked off. After recrystallization from cyclohexane, 4-methylbenzoyl-phenylphosphinic acid methyl ester melts at 99-101°C.

Yield: 180 parts (65% of theory). NMR: 2.25 (S); 3.7 (d);

7-8.1 (m)

Example 13

To a mixture of 1350 parts by volume of petroleum ether (boiling range 40-70°C), 180 parts by volume of N,N-diethylaniline and 67 parts by volume of methanol, 225 parts of diphen1-chlorophosphine, dissolved in 220 parts by volume of petroleum ether, are added while stirring at 0°C. The mixture is then stirred for a further 2 hours at room temperature. After cooling to approx. +5°C, the secreted amine hydrochloride is suctioned off and the filtrate is first distilled at 10-20 Torr, to remove all low-boiling material. The diphenyloxyphosphine is then fractionally distilled at 0.1-1 Torr. Kp. Q 5 120-124°C. Yield: 175 parts (80% calculated on diphenylchlorophosphine).

In a stirring apparatus with reflux cooler and dropping funnel, 638 parts of methoxydiphenylphosphine are slowly added to 547.5 parts of 2,4,6-trimethylbenzoyl chloride at 50-55°C. The mixture is stirred for a further 4-5 hours at 50°C, the contents of the flask are dissolved at 30°C in ether and petroleum ether is added until paleness begins. On cooling, 910 parts crystallize (87% of theory). 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. Melting point: 89-92°C, slightly yellow crystals.

Example 14

In an apparatus as described in example 13, 20 parts of 2,6-dimethoxybenzoyl chloride are suspended in 20 parts by volume of toluene, and 21.6 parts of methoxydiphenylphosphine are added dropwise to this mixture at 50-55°C with stirring. The mixture is stirred for a further 3 hours at 50°C and then recrystallized directly from toluene. 32 parts of yellowish crystals are obtained, mp: 124-126°C.

Example 15

In an apparatus as described in example 13, 91 parts of 2,4,6-trimethylbenzoyl chloride are charged. To this, 83 parts of triethyl phosphite are added at 60°C over the course of 15 minutes, and the mixture is stirred for a further 8 hours at 80°C. The contents of the flask are distilled at a reduced pressure of 0.4 mm, and the fraction at 120-122°C/0.4 mm is captured. 51 parts of 2,4,6-trimethylbenzoyl-phosphonic acid diethyl ester are obtained

(36% of theory) in the form of a slightly yellowish liquid.

Ekaempe1 16

To a mixture of 1000 parts by volume of toluene, 421 parts by volume of N,N-diethylaniline and 100 parts by volume of methanol, 214 parts of phenyldichlorophosphine are added at 0°C. The mixture is then stirred for 1 hour at room temperature, the precipitate of amine hydrochloride is suctioned off and fractionated. The dimethoxyphenylphosphine distills at 46-50°C/0.2-0.3 mm. Yield: 190 parts (93% of theory).

182.5 parts of 2,4,6-trimethylbenzoyl chloride are added dropwise at 50°C to 170 parts of dimethoxyphenylphosphine. The temperature is maintained

50°C for 5 more hours, the slightly yellowish oil dissolves at 70-80°C

in cyclohexane, and the product is then brought to crystallization by cooling to 5°C. Slightly yellowish crystals are obtained, mp: 51-52°C, yield: 81% of theory.

Additional compounds were prepared as indicated

in examples 13-16, are listed in table 2.

Example 17

A covering, pigmented varnish is produced from a mixture of 100 parts of the reaction product of bisphenol-A-diglycidyl ether and 2 mol of acrylic acid, 122 parts of butanediol-1,4-diacrylate, 6 parts of n-butanol, 122 parts of TiOj pigment. Lacquers of this type are known to those skilled in the art. 6.5 parts of 2-methylbenzoyl-diphenylphosphine oxide are added to this mixture as photoinitiator. The finished varnish is spread on glass plates to a thickness of 75 µm and irradiated with a Hg high-pressure lamp (output 80 W/cm arc length). The distance between the lamp and the lacquer film was 10 cm. The samples were pulled in an inert gas atmosphere under the lamp on a conveyor belt whose running speed could be adjusted continuously.

At conveyor belt speeds of up to 6 m/min, scratch-resistant, thoroughly cured and completely white lacquer films are obtained.

Example 18

To a binder of 65 parts of a reaction product of bisphenol-A diglycidyl ether with two equivalents of acrylic acid and

35 parts of butanediol-1,4-diacrylate are added in each case

3 parts photoinitiator. These mixtures are pressed onto glass plates in a layer thickness of 80 µm with a spreader knife and irradiated (Hg high-pressure lamp, 80 W/cm arc length, distance 10 cm). The irradiation time required to achieve a nail-hard, scratch-resistant surface is represented by the maximum possible conveyor belt speed with which the samples could be pulled forward under the lamp. For example, the following values were measured:

Example 19

3% N-phenylglycine is added to a varnish prepared according to example 18. Application is then made to glass plates as indicated in example 14, and this is illuminated. The results follow from table 3.

Example 20

In the esterification of 431, maleic anhydride divides and

325 parts phthalic anhydride with 525 parts propylene glycol-1,2 produces an unsaturated polyester. After adding 0.01% hydroquinone, a 66% solution in styrene is produced from the polyester. 97 parts of this UP resin is added to 1.5 parts of pivaloyl diphenylphosphine oxide.

For the light curing experiments, 10 parts of a 1% solution of paraffin (softening range 50-52°C) in styrene are added to 100 parts of this mixture, and the resin is applied to glass plates with a film application device with a slot depth of 400 um. After approx. After 1 minute of deaeration, the films are illuminated with fluorescent lamps (Philips TLA 05/40 W), which are placed at a distance of 4 cm.

After an illumination time of 4 min. the films have a pendulum hardness of 76 s (according to Kttnig) and can be sanded and treated with swabs.

Example 21

A binder prepared according to example 18 mixed in each case with 3 parts of a photoinitiator according to table 3 and then applied to white photographic paper in a layer thickness of 76 µm and drawn under a Hg high-pressure lamp (output 80 W/cm arc length ) under inert gas at a speed of 72 m/min. The samples hardened in this way were hard as nails and had a high gloss. As table 4 shows, the compounds according to the invention greatly exceed the state of the art which is characterized by the initiators benzyldimethylketal and the mixture benzyldimethylketal/benzophenone/methyldiethanolamine.

Example 22

To measure the curing activity of the compounds according to the invention in photopolymerizable unsaturated polyester resins, the temperature course during illumination was plotted. For this purpose, the following resins were produced: Resin A: By melt condensation of maleic acid, o-phthalic acid, ethylene glycol and propylene glycol-1.2 in the molar ratio 1 : 2 : 2.4 : 0.85, an unsaturated polyester with an acid number of 50 is obtained.

Resin B: From maleic acid, tetrahydrophthalic acid and diethylene glycol in the molar ratio 1 : 0.5 : 1.5, a UP resin with an acid number of 46 is obtained.

For use, both resins were dissolved 65% in styrene and stabilized with 100 ppm hydroquinone.

10 g of such a resin is sensitized with 0.35% of the various photoinitiators and then irradiated in a dish

white tin (diameter 3.8 cm), which for thermal insulation is wrapped in polyurethane resin foam. The radiation source is a UV field (87 x 49 cm) of ten lamps arranged next to each other (TUV 40 W/0.5, Philips, whereby the distance to the sample is 10 cm). The temperature course in the resin during curing is recorded via a thermocouple with a printer. The measured values obtained are compiled in table 5.

Example 23

In one binder of 65 parts of a reaction product of bisphenol-A diglyzide and acrylic acid, 35 parts of butane-1,4-diol diacrylate and 3 parts of methyldiethanolamine, 3 parts of photoinitiator are dissolved. The finished mixture is spread on glass plates in a layer with a thickness of 60 µm and is passed at a distance of 10 cm under a mercury high-pressure lamp (output 80 W/cm arc length). The reactivity is indicated as the maximum possible conveyor belt speed at which a scratch-resistant curing of the lacquer film is still achieved.

2,6-substituted derivatives also show a significantly higher reactivity than derivatives bearing the substituents in other positions in the benzoyl residue.

Example 24

A lacquer system analogous to example 23 is added to the following photoinitiator combinations and tested as indicated in example 23.

Example 25

In a mixture of 55 parts of a reaction product of bisphenol-A diglycidether and acrylic acid, 45 parts of butanediol diacrylate, 55 parts of rutile pigment and 3 parts of methyldiethanolamine, the following photoinitiators are dissolved. The finished mixture is fed with a spiral (80 µm) onto glass plates and passed under two successively arranged Hg high-pressure lamps (output 80 W/m each). The conveyor speed, at which a scratch-resistant cure is still possible, characterizes the reactivity of the initiator system.

In a further batch, the above-mentioned composition is spread with a spreader knife to a layer thickness of 200 µm. After UV curing, the layer is loosened, washed with acetone, and then the cured layer thickness is determined. You thus get a measure of the through-hardening.

Example 26

The photoinitiators to be compared are dissolved in a mixture of 55 parts of a reaction product of bisphenol-A diglycidether and acrylic acid, 45 parts of butanediol diacrylate and 55 parts of rutile pigment. The finished varnish is spread to a thickness of 80 μm on glass plates and cured as described in example 25. It is found that benzyldimethylketal or α-hydroxyisobutyrophenone alone does not cause any hardening of the pigmented varnish. Without a significant reduction in curing, however, they can replace part of the initiator 2,4,6-trimethylbenzoyl-diphenylphosphinoxide according to the invention.

Example 27

In the esterification of 431, maleic anhydride divides and

325 parts phthalic anhydride with 525 parts propylene glycol-1,2 produces an unsaturated polyester. After the addition of 0.01% hydroquinone, a 66%±g solution in styrene is prepared from the polyester, and in this the relevant photoinitiator is dissolved.

For the light curing experiments, 10 parts of a 1% solution of paraffin (softening range 50-52°C) in styrene are added to 100 parts of this mixture, and the resin is applied to glass plates with a film application device with a gap depth of 400 µm. After approx. After 1 minute of deaeration, the films are illuminated with fluorescent lamps (Philips TIA05/40 W), which are placed at a distance of 4 cm. This testing was repeated after a storage time in the dark for the photopolymerizable mixture of 5 days at 60°C. After an illumination time of 2 minutes, the following results are obtained:

Example 28

By esterification of 143 parts of tetrahydrophthalic anhydride and 175 parts of maleic anhydride with 260 parts of diethylene glycol, an unsaturated polyester resin is produced which is dissolved 64% in styrene and stabilized with 0.01% hydroquinone.

For light curing experiments, 20 parts of Ti02, 10 parts of a 1% paraffin solution in styrene as well as the initiator in question in the indicated amount are added to 100 parts of this solution. The resin is applied to glass plates with a spreading knife

in a layer thickness of 60 µm and is immediately irradiated for 20 seconds under a Hg high-pressure lamp (100 W/cm arc length) at a distance of 10 cm. The following results are obtained:

While the resins sensitized with the initiators according to the invention after a storage of 5 days at 60°C did not show any significant decrease in reactivity, the batch with benzyl/amine was already gelled.

Example 29

To 100 parts of a resin prepared according to example 28, 15 parts of a 0.7% solution of paraffin (m.p. 50-52°C) in styrene, in which the photoinitiator has been dissolved, are added. You also add 3% colored pigment to the resin, spread 100 µm thick films onto glass and illuminate for 20 sec. as in example 10. It can be seen from these results that the initiators according to the invention are also suitable for curing colour-pigmented varnishes or of printing inks, also when they are combined with initiators that until now have not been, or have only been slightly, usable, i.e. that they show a synergistic effect.

Claims (13)

1. Photopolymerizable masses for photopolymerizable coating agents, varnishes and printing inks, characterized in that they contain acylphosphine oxide compounds of the general formula as photoinitiators where R^" means a straight-chain or branched alkyl residue with 1-6 carbon atoms, a cyclohexyl-, cyclopentyl-, aryl-, halogen-, alkyl- or alkoxy-substituted aryl-, an S- or N-containing 5- or 6- linked heterocyclic residue; 2 112 R has the meaning of R , where R and R can be the same or different, or means an olefin residue with 1-6 carbon atoms, 1 2 an aryloxy or an aryl olefin residue, or R and R can be connected to each other to form a ring; R 3 means a straight-chain or branched alkyl radical with 1-18 carbon atoms, a cycloaliphatic radical containing 3-12 carbon atoms, a phenyl radical, an alkyl-, alkoxy- or thioalkyl-substituted phenyl or naphthyl radical, an S- or N-containing 5 - or 6-membered heterocyclic residue, where the residues R <3> optionally carry additional functional groups, or means the grouping where R 1 and R 2 have the above meaning and X means a phenylene residue or an aliphatic or cycloaliphatic divalent residue containing 2-6 carbon atoms; and where optionally at least one of the residues R 1 to R 3 is olefinically unsaturated. 2. Photopolymerizable masses as stated in claim 1, characterized in that R3.<i> the acylphosphine oxide compounds used as photoinitiators is a tertiary aliphatic residue. 3. Photopolymerizable masses as stated in claim 1, characterized in that R<3> in the acylphosphine oxide compounds used as photoinitiators is a mono-, di- or trialkyl-substituted phenyl residue, where the alkyl residue or residues contain 1-8 carbon atoms. 4. Photopolymerizable masses as set forth in claim 1, characterized in that Ri the acylphosphine oxide compounds used as photoinitiators is at least a doubly substituted phenyl, pyridyl or thienyl residue which carries the substituents A and B at least on both of the carbon atoms that are neighbors to the point of attachment with the carbonyl group which may mutually be the same or different, and stand for alkyl, alkoxy or alkylthio residues containing 1-6 carbon atoms, cycloalkyl residues containing 5-7 carbon atoms, phenyl residues or halogen atoms, or R 3 is one at least in 2,8- the positions at A and B substituted α-naphthyl residue or at least in the 1,3-positions at A and B substituted B-naphthyl residue. 5. Photopolymerizable masses as stated in claim 4, characterized in that R3 in the acylphosphine oxide compounds used as photoinitiators is a 2,4,6-trimethylphenyl-, 2,3,6-trimethylphenyl-, 2,6-dimethoxyphenyl-, 2,6 -dichlorophenyl-, 2,6-bis-(methylthio)-phenyl- or a 2,3,5,e^tetramethyl-phenyl residue. 6. Photopolymerizable masses as stated in claim 4, characterized in that R 3 in the acylphosphine oxide compounds used as photoinitiators is a 2,4,6-tri-methylpyridyl-3- or a 2,4-dimethylthienyl-3-residue. 7. Photopolymerizable masses as specified in claim 4, characterized in that R3 in the acylphosphine oxide compounds used as photoinitiators is a 1,3-dimethyl-naphthalene-2-, a 2,8-dimethyl-naphthalene-1-, a 1,3- dimethoxy-naphthalene.n-2- or a 2, 8-dimethoxynaphthalene-1-residue. 8. Photopolymerizable masses as stated in bold of claims 4 to 7, characterized in that R<1> and R<2> in the acylphosphine oxide compounds used as photoinitiators have the meaning phenyl or Cj-Cg-alkyl substituted phenyl. 9. Photopolymerizable masses as stated in any of the preceding claims, characterized in that the acylphosphine oxide compounds are used in combination with secondary and/or tertiary amines. 10. Photopolymerizable masses as stated in any of the preceding claims, characterized in that the acylphosphine oxide compounds used as photoinitiators are used in a concentration of 0.001 to 20%, preferably 0.01 to 4%. 11. Photopolymerizable masses as specified in any of the preceding claims, characterized in that the acylphosphine oxide compounds used as photoinitiators are used in a mixing ratio acylphosphine oxide compounds aromatic ketone of 10:1 to 1:30, preferably 1:1 to 1:10/1 coating agents , varnishes and printing inks. 12. Photopolymerizable masses as stated in claim 11, characterized in that a tertiary amine is added as an accelerator in a concentration of 0.5-15%. 13. Photopolymerizable masses as stated in any of the preceding claims, characterized in that the acylphosphine oxide compounds are used in combination with a tert.* amine as well as with benzophenone and/or thioxanthone, which may optionally also carry methyl, isopropyl, chlorine - or chloromethyl residues, or with benzyl dimethyl ketal, benzoin isopropyl ether, α-hydroxyisobutyrophenone, diethoxyacetophenone or p-tert.-butyltrichloroacetophenone with the precaution that the total content of photoinitiators is between 1% and 20% of the total amount of the photopolymerizable mixture.