CARBAZOLE PHOTOINITIATORS FOR THE PHOTOPOLYMERIZATION OF UNSATURATED COMPOUNDS

Abstract: Carbazole photoinitiators for the photopolymerization of unsaturated compounds are provided, having the formulae: wherein: R₁ and R₂ are each alkyl having from one to about eighteen carbon atoms; or are taken together to form alkylene having from about two to about twelve carbon atoms; R₃ is selected from the group consisting of hydrogen; alkyl having from one to about eighteen carbon atoms; and acyl having from about two to about twelve carbon atoms; in which R₅ is selected from the group consisting of hydrogen; alkyl and alkenyl having from one to about eighteen carbon atoms; and R₆ and R₇ are selected from the group consisting of alkyl; hydroxyalkyl having from one to about eighteen carbon atoms; and R₆ and R₇ taken together to form alkylene having from about two to about twelve carbon atoms; and oxadialkylene and iminodialkylene hav­ ing from four to about twenty-four carbon atoms; Y₁ is hydrogen or Y₂ is selected from the group consisting of hydrogen, halogen, and nitro; R₄ is a direct linkage (-) or alkylene having from about two to about twelve carbon atoms; X₂ is -O-R₈-O- or in which: R₈ is alkylene having from about two to about twelve carbon atoms; R₉ and R₁₀ are alkyl having from one to about eighteen carbon atoms; or are taken together to form alkylene having from about two to about twelve carbon atoms.

Description: Photochemical polymerization processes have attained substantial importance in the art, especially in those cases where thin layers have to be hardened in a short time, for example, in the hardening of varnish coatings, or in the drying of printing inks. Many compounds are known as photoinitiators for the photopolymerization of unsaturated compounds. Aromatic ketones such as benzophenone are most commonly used, due to their excellent solubility to unsaturated compounds. Recently, α-substituted aromatic aliphatic ketones were proposed as photoinitiators in U. S. Patent No. 4,308,400, and sulfur-containing-α-amino-aromatic-aliphatic ketones were proposed as photoinitiators in Japan Kokai No. 83-157805. Many of these known photoinitiators have the shortcoming that when mixed with an unsaturated compound they display an insufficient storage life. Furthermore, these photoinitiators tend to cause an undesirable yellowing of the polymerized composition, and they are insufficiently reactive, as evidenced by a relatively long polymerization time. Some are rapidly inactivated by atmospheric oxygen. The European Patent Application 0117 233 describes photosetting dyed material containing a) an olefinically unsaturated photopolymerizable binder, b) a pigment or a dye and c) at least one of the compounds I, II or III acting as photoinitiator wherein Ar is an aromatic group containing oxygen, selected from one of the following formulae wherein n is 1, 2 or 3, Z is a direct bond -CH₂-, -CH₂CH₂- or -O-, Z' is -CH₂CH₂-, unsubstituted or substituted by CH₃, or -(CH₂)₃-, R⁴, R⁵, R⁶, R⁷ and R⁸ independently from each other are hydrogen, halogen, C₁-C₄-alkyl, C₃-C₁₂-alkenyl, C₅-C₆-cycloalkyl, phenyl, -COOH, -COO(C₁-C₄)-alkyl, -OH or -OR⁹, provided that at least one of the groups R⁴ to R⁸ is -OH or -OR⁹, R⁹ means c₁-C₁₂-alkyl, C₃-C₁₂-alkenyl, cyclohexyl, hydroxycyclohexyl, C₁ -C₄-alkyl substituted by one or several of the groups Cl, Br, CN, SH, -N(C₁-C₄-alkyl)₂, piperidino, morpholino, OH, -O(C₁-C₄-alkyl), -OCH₂ CH₂ CN, -OCH₂CH₂COO(C₁-C₄-alkyl), -OOC-R¹⁰, -COOH, -COO(C₁-C₈-alkyl), -CONH(C₁-C₄-alkyl), -CON(C₁-C₄-alkyl)₂, -CO-(C₁-C₄-alkyl) or -CO-phenyl-substituted C₁₋₄ alkyl, 2,3-epoxypropyl, (CH₂CH₂O) q -H, phenyl, C₇-C₉-phenylalkyl, C₇-C₉-phenylhydroxyalkyl, phenyl substituted by halogen, C₁-C₄-alkyl, C₁-C₄-alkoxy or -COO(C₁-C₄-alkyl); tetrahydropyranyl, tetrahydrofuranyl, a group -CO-R¹⁰, -COO(C₁-C₈-alkyl), -CONH(C₁-C₄-alkyl) -CON(C₁-C₄-alkyl)₂, -Si(R¹⁵) (R¹⁶)₂, -SO₂-R¹⁷ or a group with the formula wherein p is 1 to 4, g is 2 to 20, A is oxygen or sulphur and B is a direct bond or a C₁-C₁₀-alkylene group, or R⁹ is a group of the formula R¹⁰ is C₁-C₄-alkyl, C₂-C₄-alkenyl or phenyl, X and X' are amino groups -N(R¹¹) (R¹²), Y means a divalent group of the formula -N(R¹³)- or -N(R¹³)-(CH₂) x -N(R¹³')-, wherein x is 1 to 8, R¹¹ means hydrogen, C₁-C₁₂-alkyl, C₂-C₄-alkyl substituted by one or several of the groups OH, C₁-C₄-alkoxy, CN or -COO (C₁-C₄-alkyl); C₃-C₅-alkenyl, cyclohexyl, C₇-C₉-phenylalkyl, phenyl or phenyl substituted by Cl, C₁-C₄-alkyl, OH, C₁-C₄-alkoxy or -COO(C₁-C₄-alkyl), or R¹¹ and R¹ together stand for the group -CH₂OCH₂-, R¹² has one of the meanings given for R¹¹ or means together with R¹¹ C₃-C₇-alkylene that can be interrupted by -O-, -S- or -N(R¹⁴ )-, or R¹² means together with R² C₁-C₈-alkylene C₇-C₁₀-phenylalkylene o-xylylene or C₂-C₄-oxa- or azaalkylene, R¹³ and R 13' are hydrogen, C₁-C₁₂-alkyl, C₁-C₄-hydroxyalkyl, cyclohexyl or benzyl, R¹⁴ means hydrogen, C₁-C₄-alkyl, C₁-C₄-hydroxyalkyl, -CH₂CH₂CN or -CH₂CH₂COO(C₁-C₄-alkyl), R¹⁵ and R¹⁶ mean C₁-C₄-alkyl or phenyl, R¹⁷ means a C₁-R₁₈-alkyl, phenyl or C₇-C₂₀-alkylphenyl, Ar' has one of the meanings given for Ar, R¹ and R² independently from each other are C₁-C₈-alkyl, C₁-C₄-alkyl substituted by OH, C₁-C₄ -alkoxy, CN, -COO(C₁-C₈-alkyl) or N(R¹¹) (R¹²); allyl, phenyl, chlorophenyl,R⁹-O-phenyl or C₇-C₉-phenylalkyl or R¹ and R² together mean C₂-C₈-alkylene C₃-C₉-oxa- or azaalkylene. R³ is a direct bond, C₁-C₆-alkylene, C₂-C₆-oxaalkylene or cyclohexylene or forms together with both substituents R² and both C-atoms which those substituents are bond to, a cyclopentane-, cyclohexane-, cyclohexene-, endomethylencyclohexane-or endometylencyclohexene ring, or a salt of such compound formed by acid addition. Furthermore these compounds used as photoinitiators are claimed. The US-A-3 946 021 discloses bis-basic ketones of carbazole having the following formula: wherein Z is hydrogen or straight or branched lower alkyl having from 1 to 4 carbon atoms; A is a straight or branched alkylene chain having from 1 to about 6 carbon atoms; and each Y is A. the group wherein R¹ and R² are individually hydrogen or lower alkyl having from 1 to about 4 carbon atoms; or B. the group wherein n is a whole integer of 4 or 5, and R³ is hydrogen or lower alkyl having from 1 to about 4 carbon atoms and can be linked to any one of the carbon atoms of the heterocyclic group; or C. the group wherein X is oxygen or NR⁴, and R⁴ is hydrogen or lower alkyl of from 1 to about 4 carbon atoms; or a pharmaceutically acceptable acid addition salt of said base. It is stated that this compounds have antiviral activity. There is therefore a need in the art for photoinitiators which are readily soluble in the substrate, and which, having a good storage life in the dark, initiate the photopolymerization more rapidly and give a higher polymer yield per unit of time, than the known photoinitiators. In accordance with this invention, carbazole photoinitiators are provided having the following formulae (I), (II) and (III) that possess the required properties as photoinitiators. In particular, they effect a rapid photopolymerization, and either do not display the shortcomings referred to, or display them to a much lesser degree, than the known photoinitiators. Furthermore, they are suitable for the photochemical cross linking of polyolefins. Subject matter of this invention is a photopolymerizable prepolymer composition comprising carbazole photoinitiator which has one of the formulae: wherein: R₁ and R₂ are each alkyl having from 1 to 18 carbon atoms; or are taken together to form alkylene having from 2 to 12 carbon atoms; R₃ is selected from the group consisting of hydrogen; alkyl having from 1 to 18 carbon atoms; and acyl having from 2 to 12 carbon atoms; in which R₅ is selected from the group consisting of hydrogen; alkyl and alkenyl having from 1 to 18 carbon atoms; and R₆ and R₇ are selected from the group consisting of alkyl; hydroxyalkyl having from 1 to 18 carbon atoms; and R₆ and R₇ taken together to form alkylene having from 2 to 12 carbon atoms; and oxadialkylene and iminodialkylene having from 4 to 24 carbon atoms; Y₂ is selected from the group consisting of hydrogen, halogen and nitro; R₄ is a direct linkage (-) or alkylene having from 1 to 12 carbon atoms; in which: R₈ is alkylene having from 2 to 12 carbon atoms; R₉ and R₁₀ are alkyl having from 1 to 18 carbon atoms; or are taken together to form alkylene having from 1 to 12 carbon atoms; and an unsaturated compound having at least one ethylenic double bond that is photopolymerizable to form a polymer. Exemplary R₁, R₂, R₃, R₅, R₆, R₇, R₉ and R₁₀ alkyl are methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, isobutyl, amyl, sec-amyl, isoamyl, tert-amyl, hexyl, isohexyl, sec-hexyl, tert.-hexyl, heptyl, isoheptyl, tert.-heptyl, sec.-heptyl, octyl, isooctyl, 2-ethylhexyl, nonyl, isononyl, tert.-nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, heptadecyl and octadecyl. Exemplary R₁ and R2 taken together as alkylene include ethylene, propylene, butylene, amylene, hexylene,heptylene, octylene, nonylene, decylene and dodecylene. Exemplary R₃ acyl include acetyl, propionyl, butyroyl, valeroyl, caproyl, 2-ethylhexanoyl, decanoyl and lauroyl; acryloyl, methacryloyl, vinylacetyl, benzoyl, toluoyl, t-butylbenzoyl and chlorobenzoyl. Exemplary R₅ alkenyl include allyl and octadecenyl. Exemplary R₆ and R₇ hydroxyalkyl include hydroxyethyl, 2-hydroxypropyl and 2-hydroxybutyl, 2-hydroxyhexyl, 2-hydroxyoctyl, 2-hydroxynonyl, and 2-hydroxydodecyl. Exemplary R₆ and R₇ alkylene, oxadialkylene and iminodialkylene include ethylene, propylene, butylene, amylene, hexylene, heptylene, octylene, decylene and dodecylene, oxadiethylene and iminodiethylene. Exemplary Y₂ halogen include chlorine, bromine, fluorine and iodine. Exemplary R₄ alkylene include methylene, ethylene, trimethylene, tetramethylene, hexamethylene, octamethylene, decamethylene and dodecamethylene. Exemplary R₈ alkylene include ethylene, propylene, 2, 2-dimethylpropylene, 1,4-butylene, hexamethylene and decamethylene. Exemplary R₉ and R₁₀ alkylene include methylene, ethylene, propylene, butylene, amylene, hexylene, octylene, decylene and dodecylene. A further subject matter of this invention are carbazole photoinitiator for the photopolymerization of unsaturated compounds of the formulae (I), (II) and (III) shown above. Special embodiments of the carbazole photoinitiators are those in which: R₁ and R₂ are each alkyl having from 1 to 18 carbon atoms, R₁ and R₂ are taken together to form alkylene having from 2 to 12 carbon atoms, R₃ is hydrogen, R₃ is alkyl having from 1 to 18 carbon atoms or R₃ is acyl having from 2 to 12 carbon atoms. The following are carbazole compounds of the formulae (I), (II) and (III) falling within the invention. 1. 3-(2-methyl-2-dimethylaminopropionyl) carbazole 2. 3-(2-methyl-2-morpholinopropionyl)-9-methylcarbazole 3. 3,6-bis(2-methyl-2-morpholinopropionyl)-9-methylcarbazole 4. 3-(2-methyl-2-morpholinopropionyl)-9-butylcarbazole 5. 3-(2-ethyl-2-piperidinopropionyl)-9-butylcarbazole 6. 3-(2-methyl-2-diethanolaminopropionyl)-9-methylcarbazole 7. 3-(2-methyl-2-dibutylaminopropionyl)-6-chlorocarbazole 8. 3-(2-methyl-2-piperazinopropionyl-6-nitro-9-methylcarbazole 9. 3-(2-methyl-2-morpholinopropionyl)-9-acetylcarbazole 10. 3,6-bis(2-methyl-2-morpholinopropionyl)-9-benzoylcarbazole 11. 3-(2-methyl-2-hydroxypropionyl)-9-methylcarbazole 12. 3-(2-methyl-2-methoxypropionyl)-9-methylcarbazole 13. 3-(2-methyl-2-allyloxypropionyl)-9-methylcarbazole 14. 3-(1-hydroxycyclohexanoyl)-9-butylcarbazole 15. 1,4-bis(1-(9-methyl-3-carbazolyloyl)isopropyl)piperazine 16. N,N'-dimethyl-N,N'-bis(1-(9-methyl-3-carbazolyloyl) isopropyl)ethylenediamine. The carbazole compounds of formulae (I), (II) and (III) can be readily prepared by known procedures, for example, by the method described in US-patent No. 4,308,400. The compounds of formulae (I) and (III) can be prepared by brominating the compound shown below, reacting the resulting compound with H-X₁ or H-X₂-H: The compounds of the formula (II) can be prepared by brominating the compound shown below, reacting the resulting compound with H-X₁. The following example is illustrative: EXAMPLE I Synthesis of 3-(2-methyl-2-morpholinopropionyl)-9-methylcarbazole 3-(2-Methylpropionyl)-9-methylcarbazole 15 g was dissolved in 50 ml of carbon tetrachloride. A solution of 12 g of bromine in 30 ml of carbon tetrachloride was added dropwise over one hour at room temperature, and the reaction mixture then stirred for one additional hour at room temperature. Then nitrogen gas was introduced to remove the hydrogen bromide produced and excess bromine Morpholine 30 g was added to the reaction mixture, which was then heated up to 120°C, while carbon tetrachloride was distilled off. The solution was stirred for 3 hours at 120°C, and the morpholine hydrobromide filtered out, and excess morpholine distilled off. Toluene 100 ml was added, and the solution was washed with water, and then extracted with aqueous 3 N HCl solution. The HCl solution was neutralized by adding 3 N NaOH solution, and then extracted with toluene. The toluene solution was washed with water, and then toluene was distilled off. The residue was recrystallized from ethanol. The desired product, melting at 164-166°C, was obtained. If desired, the photoinitiators of this invention can be combined with secondary and tertiary alkyl and hydroxyalkyl amines, which act as accelerators. Such amines include, for example, triethanolamine, triisopropanolamine, methyl-diethanolamine, octyl-diethanolamine, dodecyl-diethanolamine, octadecyl-diethanolamine, dibutylethanolamine, dioctyl-ethanolamine, methyl-hydroxyhexyloctanolamine, diethanolaniline, diethanolamine, methyl-ethanolamine, butyl-ethanolamine, dodecyl-ethanolamine, tetrahydroxyethyl-hexamethylenediamine, triethylamine, tributylamine, dimethylaminopropylamine, dimethylaniline, diethylamine, dibutylamine, dioctylamine, tetramethyl-ethylenediamine and Michler's ketone. Among these amines, the alkanolamines are preferable, due to their excellent effect. The photoinitiators of this invention can polymerize or harden any unsaturated compounds containing at least one ethylenic double bond in the molecule, as monomers or prepolymers, by actinic light. Such unsaturated compounds include, for example, unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid and maleic acid; esters or amides of such unsaturated carboxylic acids with mono- or polyhydric alcohols or amines; methacrylates of polyhydroxyesters obtained from polyol and polycarboxylic acid; unsaturated polyesters or polyamides obtained from unsaturated dicarboxylic acids and polyols or polyamines; urethane acrylates obtained from urethane compounds containing isocyanate groups prepared from diisocyanates with polyols and hydroxyalkyl methacrylates; epoxyacrylates obtained from polyglycidyl ethers of bisphenols or polyols and methacrylic acid; polyesters obtained from glycidyl methacrylate and dicarboxylic acid; dimethacryl modified polyesters or polyamides obtained from polyesters or polyamides containing carboxyl groups and glycidyl methacrylate. The unsaturated esters can be derived from mono- or polyhydric alcohols having from one to six hydroxyl groups and from one to eighteen carbon atoms, in an open aliphatic chain or carboxylic or heterocyclic ring, including methanol, ethanol, butanol, allyl alcohol, octanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, glycerine, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl) isocyanurate, pentaerythritol, diglycerine, ditrimethylolpropane and dipentaerythritol; mono- or poly-amines include ammonia, methyl amine, butylamine. The unsaturated amides can be derived from mono or polyamino amines having from one to six amino groups and from one to eighteen carbon atoms in an open aliphatic chain or carboxylic or heterocyclic ring, including octylamine, diethylamine, dibutylamine, ethylenediamine, diethylenetriamine, piperazine, 1,6-hexamethylenediamine and melamine. Preferred examples of esters and amides of unsaturated carboxylic acids include methyl-, ethyl-, butyl-, isooctyl- and 2-hydroxyethyl-acrylate, methyl- and ethyl-methacrylate, ethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, tris-(2-hydroxyethyl) isocyanurate triacrylate, dipentaerythritol tetraacrylate; dipentaerythritol, hexaacrylate, glycerine diacrylate, triethylene glycol dimethacrylate, pentaerythritol trimethacrylate, ethylene glycol dicrotonate, diallyl fumarate bis(acryloyloxyethylphenyl)-propane, acrylamide, methacrylamide, ethylene-bis-(acrylamide), hexamethylene-bis(acrylamide) and methylene-bis-(acrylamide). Examples of other photopolymerizable compounds are diallyl phthalate, diallyl malonate, divinyl phthalate, vinyl acetate, isobutyl vinyl ether, ethylene glycol divinyl ether, styrene, acrylonitrile, triallyl isocyanurate and triallyl phosphate. The photoinitiators of this invention are effective in small amounts, and the amount is not critical, but is selected to give the desired rate of photopolymerization according to the unsaturated compound used. Good results are obtained in amounts within the range from about 0.1 to about 20 parts by weight, based on 100 parts of above unsaturated compound. More than this can be used. The photopolymerizable systems comprising the photoinitiator and unsaturated compound can contain other conventional additives, such as heat polymerization inhibitors, colorants or pigments, plasticizers, surface-protecting agents, and lubricants. Heat-polymerization inhibitors include hydroquinone, p-methoxyphenol, pyrogallol, catechol, 2, 6-di-t-butyl-p-cresol, β-naphthol, and t-butylhydroquinone. Colorants or pigments include carbon black, metal (silver, aluminum) powder, chrome yellow, titanium white, talc, alumina, Milori Blue, Chrome Vermillion, Hansa yellow, Benzidine Yellow, Vulcan Orange, Permanent Orange, Lake Red C, Brilliant Carmine B, Rhodamin Lake, Eosine, Victoria Blue Lake, Phthalocyanine Blue, Phthalocyanine Green, Quinacridone Red, Dioxazine Violet and Methyl Violet. The polymerization is carried out in the usual way, by irradiation with light. Suitable light sources are, for example, carbon arc, mercury high pressure lamp, xenon lamp, metal halide lamp, tungsten lamp, argon laser and helium-cadmium laser. The following Examples represent preferred embodiments of photopolymerization systems utilizing photoinitiators of formulae (I), (II) and (III). All parts indicated are by weight. The control compound 2 is known from EP-A-0 003 002. Examples 1 to 8 A resin mixture composed of 75 parts of NK ester U-108A (urethane acrylate (m.w. = 1500) available from Shinnakamura Kagaku), 25 parts of 1,6-hexanediol diacrylate and 0.5 part of photoinitiator as indicated in Table I was applied to paper using a film-drawing device to a thickness of 50 mµ. The films were irradiated with a mercury high pressure lamp (Toshiba; Model H-400P) for 15 seconds (distance = 12 cm). The pencil hardness of the hardened films was measured, and the results are shown in Table I. The superior hardness when the photoinitiator of the invention was used is apparent from the results. Examples 9 to 16 A resin mixture composed of 80 parts of NK-ester UVX-2(epoxy acrylate (m.w.= 1500) available from Shinnakamura Kagaku), 20 parts of trimethylolpropane triacrylate, 70 parts of TiO₂, 6 parts of N-methyldiethanolamine and 6 parts of photoinitiator as indicated in Table II was applied to paper using a film-drawing device to a thickness of 10 mµ. These films were irradiated with a mercury high pressure lamp (Toshiba; Model H-400P) for 30 seconds (distance = 15 cm). The pencil hardness of the hardened films was then measured, and the results are shown in Table II. The superior hardness when the photoinitiator of the invention was used is apparent from the results. Examples 17 to 23 A resin mixture composed of 80 parts of NK-ester U-108A (urethane acrylate (m.w.= 1500) available from Shinnakamura Kagaku), 20 parts of trimethylolpropane triacrylate, 22 parts of phthalocyanine blue (Dainichiseika; SR-5020), 7 parts of ethyl-4-dimethylaminobenzoate and 7 parts of photoinitiator as indicated in Table III was applied to paper using a film-drawing device to a thickness of 10 mµ. These films were irradiated with a mercury high pressure lamp (Toshiba; Model H-400P) for 30 seconds (distance = 15 cm). The pencil hardness of the hardened films was measured, and the results are shown in Table III. The superior hardness when the photoinitiator of the invention was used is apparent from the results.

Claims: A photopolymerizable prepolymer composition comprising a carbazole photoinitiator which has one of the formulae: wherein: R₁ and R₂ are each alkyl having from 1 to 18 carbon atoms; or are taken together to form alkylene having from 2 to 12 carbon atoms; R₃ is selected from the group consisting of hydrogen; alkyl having from 1 to 18 carbon atoms; and acyl having from 2 to 12 carbon atoms; in which R₅ is selected from the group consisting of hydrogen; alkyl and alkenyl having from 1 to 18 carbon atoms; and R₆ and R₇ are selected from the group consisting of alkyl; hydroxyalkyl having from 1 to 18 carbon atoms; and R₆ and R₇ taken together to form alkylene having from 2 to 12 carbon atoms; and oxadialkylene and iminodialkylene having from 4 to 24 carbon atoms; Y₁ is hydrogen or Y₂ is selected from the group consisting of hydrogen, halogen and nitro; R₄ is a direct linkage (-) or alkylene having from 1 to 12 carbon atoms; X₂ is -O-R₈-O- or in which: R₈ is alkylene having from 2 to 12 carbon atoms; R₉ and R₁₀ are alkyl having from 1 to 18 carbon atoms; or are taken together to form alkylene having from 1 to 12 carbon atoms; and an unsaturated compound having at least one ethylenic double bond that is photopolymerizable to form a polymer. A photopolymerizable prepolymer composition comprising a photoinitiator according to claim 1 also containing a secondary or tertiary alkyl or hydroxyalkyl amine. A process for photopolymerizing an unsaturated compound having at least one photopolymerizable ethylenic double bond, which comprises initiating the unsaturated compound with actinic light in the presence of a photoinitiator as defined in claim 1. Carbazole photoinitiators for the photopolymerization of unsaturated compounds, having one of the formulae: wherein: R₁ and R₂ are each alkyl having from 1 to 18 carbon atoms; or are taken together to form alkylene having from 2 to 12 carbon atoms; R₃ is selected from the group consisting of hydrogen; alkyl having from 1 to 18 carbon atoms; and acyl having from 2 to 12 carbon atoms; X₁ is -OR₅ or in which R₅ is selected from the group consisting of hydrogen; alkyl and alkenyl having from 1 to 18 carbon atoms; and R₆ and R₇ are selected from the group consisting of alkyl; hydroxyalkyl having from 1 to 18 carbon atoms; and R₆ and R₇ taken together to form alkylene having from 2 to 12 carbon atoms; and oxadialkylene and iminodialkylene having from 4 to 24 carbon atoms; Y₂ is selected from the group consisting of hydrogen, halogen and nitro; R₄ is a direct linkage (-) or alkylene having from 1 to 12 carbon atoms; X₂ is -O-R₈-O- or in which: R₈ is alkylene having from 2 to 12 carbon atoms; R₉ and R₁₀ are alkyl having from 1 to 18 carbon atoms; or are taken together to form alkylene having from 1 to 12 carbon atoms. Carbazole photoinitiators according to claim 4 in which R₁ and R₂ are each alkyl having from 1 to 18 carbon atoms. Carbazole photoinitiators according to claim 4 in which R₁ and R₂ are taken together to form alkylene having from 2 to 12 carbon atoms. Carbazole photoinitiators according to claim 4 in which R₃ is hydrogen. Carbazole photoinitiators according to claim 4 in which R₃ is alkyl having from 1 to 18 carbon atoms. Carbazole photoinitiators according to claim 4 in which R₃ is acyl having from 2 to 12 carbon atoms.

Inventors: KUBOTA, NAOHIRO
Applicants: ADEKA ARGUS CHEMICAL CO., LTD.
Application year: 1985
Main classification: C07D209
IPC codes: C08F2, C07D209, G03F7