New triphendioxazine compounds

Abstract: Triphendioxazine compounds according to the general formulae (Ia) or (IIa) where R 1 , R 2 , R 3 and R 4 , independently of one another, are are a C 1-8 alkyl radical or a substituted or unsubstituted C 5-6 cycloalkyl radical. The invention further relates to the use of said compounds as pigments or colorants in polymer compositions or paper pulps, in electrophotographic toners and developers, in ink-jet inks, in coatings or for printing applications.

Description: The invention relates to novel chlorine-containing triphendioxazine compounds and to their use as pigments. The invention also relates to a particularly advantageous process for preparing these triphendioxazine compounds. GB 2284427 A describes chlorine-containing, symmetrically disubstituted triphendioxazine compounds of the following general formula where the rings labelled A carry rings which are fused linearly or angularly and consist of radical members, inter alia, of the formulae -NR 1 -(CO) m- NH- and -CR 1 =CH-CO-NH- wherein R 1 is hydrogen, C 1-4 alkyl or phenyl, preferably hydrogen, methyl or ethyl; and m is 1 or 2. The preparation process disclosed in GB 2284427 A starts from intermediates i.e. amino compounds, which are ortho-substituted by an alkoxy group and are obtainable only by way of a relatively complex synthesis. The pigments disclosed in GB 2284427 A are difficultly dispersible and cannot easily be brought into pigment form. It is an object of the invention to provide new pigments possessing high fastness to solvents, migration and light, which have good thermal stabilities and a high tinting power and are also easily dispersible resp. easily to be brought into pigment form. Another object of the invention is to provide a process by which the novel pigments are obtainable and which starts from readily available intermediates. These objects are achieved by the novel triphendioxazine compounds according to Claim 1 and their use as pigments according to Claim 3. The present patent application therefore provides compounds of the general formulae (Ia)and (IIa) where R 1 , R 2 , R 3 and R 4 , independently of one another, are a C 1-8 alkyl radical or a C 5-6 cycloalkyl radical. In view of the fact that only compounds having hydrogen substituents are capable of building hydrogen bridges (which is believed to be necessary for the pigmentary properties), it is surprising that even tetrasubstituted compounds possess pigmentary properties. The substituents R 1 , R 2 , R 3 and R 4 , independently of one another, are preferably a methyl radical, an ethyl radical, an n- or i-propyl radical, an n-, i-, sec- or tert-butyl radical or a cyclohexyl radical. Preferred symmetrically tetrasubstituted compounds are the tetramethyl-, tetraethyl-, tetrapropyl (n- or i-) and tetrabutyl (n-, i-, sec- or tert-)substituted compounds. Preferred asymmetrically tetrasubstituted compounds are those for which the definitions of R 1 and R 2 are selected from the group consisting of the radicals methyl, ethyl, propyl (n- or i-) and butyl (n-, i-, sec- or tert-) and R 3 and R 4 can have any of the above definitions. It has been found that even amino compounds which are not ortho-substituted are suitable as intermediates provided that the cyclization which follows the reaction with 2,3,5,6-tetra-chlorobenzoquinone (chloranil) is carried out with manganese dioxide and concentrated sulphuric acid, e.g. from 80 to 100% strength, preferably from 90 to 95% strength. The novel compounds of the formulae (Ia) and (IIa) according to the invention are prepared by the reaction of 1 mol of chloranil with 2 mol of a compound of the general formulae (XVI) and (XVIa) where R 1 and R 2 are as defined above, and followed by the process step of the cyclization conducted with manganese dioxide (MnO 2 ) and concentrated sulphuric acid, e.g. from 80 to 100% strength, preferably from 90 to 95% strength. The advantage of this process is that it is possible to start from the intermediates (XVI)and (XVIa) which, unlike the amino compounds which carry an alkoxy group in the ortho position, are relatively easy to obtain. For example, compounds of the formula (XVI) are obtainable by a process comprising the following steps: In a first step, the reaction of 2,4-dinitrochlorobenzene (XI) with the corresponding primary amine, to give the N-substituted 2,4-dinitroaniline (XII) In a second step, the reduction of the compound of the formula XII, preferably with hydrated sodium hydrogen sulphide, to give the 1,2-diamine compound (XIII) In a third step, the cyclization of a compound of the formula (XIII), preferably with phosgene, chloroformic ester or urea, to give the 1,3-dihydrobenzimidazol-2-one compound The disubstituted intermediate required to prepare the tetrasubstituted triphendioxazine compounds is obtainable, for example, by N-alkylation of the compound of the formula (XIV) in which R 1 is as defined above, preferably using dialkyl sulphate, alkyl bromide or alkyl iodide or, respectively, benzyl bromide or benzyl chloride, to give the compound of the formula (XV) In a further step, the nitro compound of the formula (XV) is reduced, preferably by the method of Béchamp, to give the amino compound of the formula (XVI) where R 1 and R 2 are as defined above. Compounds of the formula (XVIa) are obtainable, for example, by cyclizing the compound of the formula (XIII) with oxalic acid or oxalic ester. Triphendioxazine compounds of the general formulae (Ia) and (IIa) according to the invention are used as pigments. Aftertreating the crude pigments in organic solvents in which the pigments themselves are not dissolved and at elevated temperatures, for example at from 60 to 200°C, especially from 70 to 150°C and preferably from 75 to 100°C, can often be used to further improve the pigment properties. Aftertreatment is preferably combined with a milling or kneading operation. The pigments according to the invention are excellently suited to the colouring of polymer compositions, by which are meant solvent-free and solvent-containing compositions comprising plastics or synthetic resins (in oil-based or water-based paints, in coating materials of various kinds, for the spin dyeing of viscose or cellulose acetate, or for pigmenting plastics, such as polyamide, polyethylene, polystyrene, polyvinyl chloride, rubber and artificial leather). They can also be used in printing inks for the graphical industry, for the colouring of paper pulps, for the coating of textile or for pigment printing. The resulting colorations are notable for their outstanding heat, light and weather fastness, chemical resistance, colour strength and very good applications properties, examples being their crystallization fastness and dispersing fastness, and especially for their fastness to migration, bleeding, overcoating and solvents. In addition, the pigments of the invention are also suitable as colorants in electrophotographic toners and developers, such as one- or two-component powder toners (also known as one- or two-component developers), magnetic toners, liquid toners, polymerization toners and further speciality toners (literature: L.B. Schein, "Electrophotography and Development Physics"; Springer Series in Electrophysics 14, Springer Verlag, 2nd edition, 1992). Typical toner binders are addition polymerization, polyaddition and polycondensation resins, such as styrene, styrene-acrylate, styrene-butadiene, acrylate, polyester and phenolic-epoxy resins, polysulphones, polyurethanes, individually or in combination, and also polyethylene and polypropylene, in or to which further ingredients, such as charge control agents, waxes or flow assistants may be present or may be added subsequently. A further area of application of pigments of the invention is their use as colorants in powders and powder coating materials, especially triboelectrically or electrokinetically sprayed powder coating materials, which are used to coat the surfaces of articles made, for example, from metal, wood, plastic, glass, ceramic, concrete, textile material, paper or rubber (J.F. Hughes, "Electrostatics Powder Coating", Research Studies Press, John Wiley & Sons, 1984). Powder coating resins employed are typically epoxy resins, carboxyl- and hydroxyl-containing polyester resins, polyurethane resins and acrylic resins, together with customary hardeners. Combinations of resins are also used. For example, epoxy resins are frequently employed in combination with carboxyl- and hydroxyl-containing polyester resins. Examples of typical hardener components (depending on the resin system) are acid anhydrides, imidazoles and dicyandiamide and derivatives thereof, blocked isocyanates, bisacylurethanes, phenolic and melamine resins, triglycidyl isocyanurates, oxazolines and dicarboxylic acids. The pigments of the invention are suitable, moreover, as colorants in ink-jet inks, both aqueous and non-aqueous, and in those inks which operate in accordance with the hotmelt process. In the following examples the parts and percentages are by weight. The temperatures are indicated in degrees Celsius. One part by volume corresponds to the volume of one part by weight of water. EXAMPLE 1 Derivatives of 1,3-dimethyl-1,3-dihydrobenzimidazol-2-one a) 1,3-dimethyl-5-nitro-1,3-dihydrobenzimidazol-2-one 90 parts of 5-nitro-1,3-dihydrobenzimidazol-2-one are suspended in 500 parts of aqueous sodium hydroxide solution (30%) and the suspension is heated to 53°C; 161 parts of dimethyl sulphate are added dropwise over 12 hours during which the temperature rises to 70°C. The mixture is cooled to room temperature and filtered and the solid product is washed to neutrality. Drying under reduced pressure at 80°C gives 99 parts of a beige powder of a compound of the following formula Yield 96% Melting point 206.3°C 1 H-NMR (DMSO) δ 3.35 (s, CH 3 ) - 3.37 (s,CH 3 ) - 7.28 (d, 3 J=9Hz, H-C7) - 7.98 (d, 4 J=2Hz, H-C4) - 8.00 (dd, 3 J=9Hz, 4 J=2Hz, H-C6) b) 5-amino-1,3-dimethyl-1,3-dihydrobenzimidazol-2-one c) 2,5-dichloro-3,6-bis(1,3-dimethyl-2-oxo-1,3-dihydrobenz-imidazol-5-ylamino)[1,4]benzoquinone d) Diimidazolone(4,5-b:4',5'-m)triphendioxazine-1,3,9,11-tetramethyl-6,14-dichloro-2,10-dione of the following formula Yield 41 % Melting point >300°C Microanalysis: calc. C 55.08 H 3.08 Cl 13.55 N 16.06 O 12.23 exp. C54.9 H 3.3 Cl 13.3 N 16.1 O 12.4 COMPARATIVE EXAMPLE2 Asymmetric derivatives a) 2,5-dichloro-3-(1-ethyl-2-oxo-1,3-dihydrobenzimidazol-5-ylamino)-6-(1-methyl-2-oxo-1,3-dihydrobenzimidazol-5-ylamino)[1,4]benzoquinone 12 parts of sodium acetate and 15 parts of chloranil are suspended in 200 parts of ethanol and the suspension is heated to 53°C. 10.6 parts of 5-amino-1-ethyl-1,3-dihydrobenzimidazol-2-one are added over 1 hour and the mixture is subsequently heated under reflux for 1 hour. Then a further 12 parts of sodium acetate are added, followed by 9.8 parts of 5-amino-1-methyl-1,3-dihydro-benzimidazol-2-one. The mixture is stirred under reflux for 10 hours, then the solid product is filtered off hot and washed with 400 parts of boiling ethanol and then with 500 parts of boiling water. After drying, 24 parts of the product are suspended in 200 parts of dimethylformamide, the suspension is heated at 100°C for 4 hours and filtered while hot, and the solid product is washed with 600 parts of hot (100°C) dimethyl-formamide followed by 500 parts of water. Drying under reduced pressure at 80°C gives 16 parts of a brown powder of a compound of the following formula Yield 53% Melting point >300°C IR(KBr) 3250 - 2978 - 1703 - 1595 - 1574 - 1501 - 1485 cm -1 'H-NMR (DMSO 120°C) δ 1.21 (t, 3 J=6Hz, CH 3 ) - 3.31 (s, NCH 3 ) - 3.83 (q, 3 J=6Hz, NCH 2 ) - 6.84 (m, 3 J=9Hz, 4 J=2Hz, H-C4, H-C4', H-C6, H-C6') - 7.03 (d, 3 J=9Hz, H-C7) - 7.09 (d, 3 J=9Hz, H-C7') - 9.61 (s, H-N5, H-N5') - 10.86 (s, H-N3) - 10.88 (s, H-N3') b) Diimidazolone(4,5-b:4',5'-m)triphendioxazine-3-ethyl-11-methyl-6,14-dichloro-2,10-dione 150 parts of sulphuric acid (92%) are cooled to 5°C, and 15.4 parts of 2,5-dichloro-3-(1-ethyl-2-oxo-1,3-dihydro-benzimidazol-5-ylamino)-6(1-methyl-2-oxo-1,3-dihydrobenz-imidazol-5-ylamino)-[1,4]-benzoquinone are added over 30 minutes. Then 7.1 parts of activated manganese dioxide (88%) are added over 3 hours and the mixture is subsequently heated at room temperature for 18 hours. The mixture is diluted to 80% by adding 22 parts of water, with cooling. The excess manganese dioxide is destroyed using 1.4 parts of hydrogen peroxide (30%). The mixture is filtered over a polypropylene filter and the solid product is washed with 250 parts of sulphuric acid (80%), then with 250 parts of sulphuric acid (50%) and subsequently is washed free from sulphate with water. Drying under reduced pressure at 80°C gives 10 parts of metallic-green powder of a compound of the following formula Yield 66% Melting point >300°C IR (KBr) 3086 - 3000 - 1698 - 1646 - 1560 - 1485 - 1321 cm -1 Microanalysis: calc C 54.22 H 2.75 O 12.57 exp. C 54.0 H 2.9 O 12.7 USE EXAMPLE 3 4 parts of the pigment set out in the table below are milled in a ball mill with 96 parts of a mixture of 50 parts of a 60 per cent strength solution of coco-aldehyde-melamine resin solution in butanol, 10 parts of xylene and 10 parts of ethylene glycol monoethyl ether for 24 hours. The resulting dispersion is sprayed onto sheet aluminium, left to dry in air for 30 minutes and then baked at 120°C for 30 minutes. The result is a film of the colour specified in the table below, with very good migration fastness and also good light and weathering stability. USE EXAMPLE 4 Example of the preparation of a 0.1% coloured PVC film (blend of colour pigment to white pigment 1:5): 16.5 parts of a plasticizer mixture consisting of equal parts of dioctyl phthalate and dibutyl phthalate are mixed with 0.05 parts of the pigment set out in the table below and with 0.25 parts of titanium dioxide. Then 33.5 parts of polyvinyl chloride are added. The mixture is friction-rolled on a double-roll mill for 10 minutes, the resulting sheet being continually cut with a spatula and rolled together. In the roll mill, one roll is held at a temperature of 40° and the other at a temperature of 140°. The mixture is subsequently taken off in sheet form and pressed between two polished metal plates at 160° for 5 minutes. This gives a coloured PVC film of high brightness and very good migration and light fastness. Pigment of Example Colour in Use Example 3 Colour in Use Example 4 1d red-violet red-violet 2b(Comp.) violet violet

Claims: Triphendioxazine compounds of the general formulae (Ia) and (IIa) where R 1 , R 2 , R 3 and R 4 , independently of one another, are a C 1-8 alkyl radical or a C 5-6 cycloalkyl radical. Triphendioxazine compounds according to Claim 1 in which R 1 , R 2 , R 3 and R 4 , independently of one another, are a methyl radical, an ethyl radical, an n- or i-propyl radical, an n-, i-, sec- or tert-butyl radical or a cyclohexyl radical. Use of the compounds of formulae (Ia) and/or (IIa) according to claim 1 as pigments. Use according to Claim 5 as colorants for colouring polymer compositions or paper pulps, as colorants in electrophotographic toners and developers, as colorants in ink-jet inks, as colorants in the coatings industry, as colorants for textile printing or as a printing ink in the graphical industry.

Inventors: BOEGLIN PATRICK, KAUL BANSI LAL, KEMPTER PETER, BOEGLIN, PATRICK, KAUL, BANSI LAL, KEMPTER, PETER
Applicants: CLARIANT FINANCE BVI LTD, CLARIANT FINANCE (BVI) LIMITED
Application year: 1998
Main classification: C07D498
IPC codes: C07D498, C09B19