CA1045120A - Disazo pigments and a process for their manufacture - Google Patents

Abstract

NEW DISAZO PIGMENTS AND A PROCESS FOR THEIR MANUFACTURE
Abstract of the Disclosure Disazo pigments of the formula wherein R1 denotes a H atoms, an alkyl group which contains 1-4 C atoms and is optionally substituted by a phenyl radi-cal, or an aryl radical, R2 denotes a H atom, an alkyl group containing 1-4 C atoms, a cyano or carbamoyl group, or an alkanoylamino group containing 2-4 C atoms, R3 denotes an alkyl group containing 1-4 C atoms, an alkoxycarbonyl group containing 2-6 C atoms, or a phenyl group which is optionally substituted by halogen atoms or alkyl or alkoxy group containing 1-4 C atoms, Z denotes an O atom or a N
atom, the N atom forming, conjointly with the radical R1, a benzimidazole ring, X and Y denote H or halogen atoms or methyl or nitro groups, and V denotes an O atom or a -CO-group are useful for coloring plastics in fast yellow to red shades.

Description

~a~4S12~
The present invention relates -to valuable, new disazo pigments o -the formula .

R2 ~ ~ 3 R (I) L 1 .
'`'' "
~herein Rl denotes a H atom, an alkyl group which contains 1-4 C atoms and is optionally substituted by a phenyl radical, '~
or an aryl rad.ical, particularly a phenyl radical which is optionally substituted by halogen a-toms or alkyl or alkoxy groups containing 1-4 C atoms, R2 denotes a H atom, an a].kyl group containing 1-~ C atoms, a cyano or car.barnoyl gr~up, or an alkanoylamino group containing 2-4 C atoms, R3 denotes an alkyl group containing 1-4 C atoms, an alkoxycarbonyl group c~l- :
taining 2~6 C atoms or a phenyl group which is optionally .
substituted by halogen atoms or alkyl or alkoxy groups Gon- ..
taining 1-4 C atoms, Z denotes anO atom, or a N atom which ;-conjointly with the radical R1 forms a benzimidazole ring, X and Y denote H or halogen atoms, or methyl or nitro groups and V denotes anO atom or a ~CO- group.
Ihe pig.nents of the ~ormula , '~
- .

':

1~45~LZ(~

OH ~ - O HO ~Y ~,z (II) CN

or z ~ lo/ ~3 ~ CN
p O R3 ., wherein Rl, R3 and Z have the meaning in~icated above, are j of particular in-terest.
~' The new disazo pigments are obtained if the -tetrazo i compound of a diamine of the formula H2~

: is coupled, in a molar ratio of 1:2~ with a pyridine deriva-tive of the formula ~-R2 (V) ;~ ~' HO Z
: ~ L

~ 3 ~

-"

104~2 '1,5-Dlaminoanthraquinone and 2,6~diaminoanthriaauinorle are of particular interest as the diamines.
The following further diamines should be mentioned:
4,8-dinitro-1,5-diaminoa~thraq~linone, 2,6-dimethyl-1,5-diamino-anthraquinone, 2,~-dibromo-1,5-diaminoanthraquinone~ 1,6~
diaminoanthraqui1lone 5 1,7-diaminoan-thraquinone, 1,5-dichloro-

2,6~diaminoanthraquinone, 3,7--dibromo-2,6-diaminoanthraquinone, 1,3,5,7-tetrabrorno-2,5-diarninoanthraquinone, 1,5-dinitro~2,6 diaminoanthraquinone, 2,4,6,8-tetrachloro-1,5-diaminoanlhra -~
quinone, 2,4,6,8 tetrabromo-1~5--diaminoanthraquinone, 1,5-dibromo-2,6-diaminoanthraquinone, 3,7-dibromo-2,6--diamil~o anthraquinone, 3,6-dibromo-2,7-diaminoanthraquinone and finally 2,6-diaminoxan-thone and 3 methyl--2,6-diaminoxanthone, The coupling components pre~erably correspond to the formula ~R3 ~ N (V13 - HO ~ Z
Rl `

wherein Rl, R3 and Z have the meaning lndicated.
Particular interest attaches to pyridine derivatives of the formulae 3 ~ N UO
HO (VII) ~ (VII'L) ~
Rl Xl ~1. '' - . . ,.:
~ '' ' .

109LS~2~
wherei.n ~1 ard R3 have the m.eani.ng indicated and preferably denote a me-thyl or phenyl group, and Xl and Y1 denote H or halo~en atoms, ni-tro or carbamoyl groups, alkyl, alkox~- or alkylsulphonyl ~roups containing 1~4 C atoms, alkoxycarbonyl, alkanoylamino or alkylcarbamoyl groups con-taining 2-6 C atoms, or phenox~- or phenylcarbamoyl groups which are optiona~lly substituted by halogen atoms or alkyl or alkoxy groups con~
taining 1--4 C atoms.
The pyridones of the ~ormula (VII) are known compo~nds, The following examples should be mentioned: 4~methyl-3-cyano 6-hydroxypyrid-2-one, 1 methyl-3-cyano-4~methyl-6-hydroxy-pyrid-2 one, 1-ethyl-3~cyano-4~methyl-6-hydroxypyrid~2-one, l~phenyl-3-cyano-4-methyl-6-hydroxypyrid-2-on.e, 1-p--tolyl-3-cyano~4 methyl 6-hydroxypyrid~2 one, l~p-anisyl-3-cyano-4-methyl-6-hydroxypyrid-2-one, 1-phenyl-3-cyano-4-phenyl-6- ., hydroxypyrid-2-one, 1-p-tolyl-3-cyano-4-phenyl-6~hydroxypyrid 2-one, 1-p-anisyl-3-cyano-4-phenyl-6-hydroxypyrid-2-one, 1-phenyl-3-carbonamido-4-methyl-6-hydroxypyrid-2-one, 1 phenyl_

3-carbonamido-4-phenyl-6-hydroxypyrid~2-one, 2,6-dihydroxy~-3 ~yano-4-ethoxycarbonylpyridine, 2,6-dihydroxy-4~methylpyridine, .
2,6~dihydroxy-4-phenylpyridine, 2,6-dihydroxy~4-(p-methoxy--phenyl)-pyridine, 4-methyl-2,6-dihydroxypyridine, 1-ethyl-4- :
methyl-3~ace-tylamino-6-hydroxypyrid-2-one, 1,4-dimethyl-3~
acetylamino-6-hydroxypyrid-2-one, 1-ethyl~4-phenyl-3-acetyl- -amino-6-hydroxypyrid-2-one and 1-phenyl-4 methyl-3-acetyl-amino-6-hydroxypyrld-2-one. .`
The benzimidazolopyridines are appropriately obtained by ;

.
_ 5 ~ .-,:
' ;' :~ `

~ 04S~
kno~ ~rocesses by condensation of a benzimidazole o. the formula ~- C1~2~R2 ,~ , ~1 . ' - wherein R2, Xl and Yl have -the mean.ing indicated, ~ith an acylacetic ester o~ the formula '.

~jCOCH2COOR . . ' .
:, wherein R denotes an alkyl group containing 1-4 C atoms, and R3 has the meaning indicated.
The follo~.Ting examples of acylacetic esters should be mentioned: acetaacetic acid methyl ester, acetoacetic acid ethyl ester, benzoylacetic acid ethyl ester and oxalacetic acid diethyl ester The following benzimidazoles should be mentioned: 2-cyanomethyl-benzimidazole, 2-cyanomethyl-4-chloro-benzimidazole, 2-cyanomiethyl-5-chloro-benzimidazole, 2-cyanomethyl-5,6-dichloro-benzimidazole, 2-cyanomethyl-4 chloro-6-methyl~
benzimidazole, 2-cyanomethyl-5-methoxy-benzimidazole, 2~cyano me-thyl-6~ethoxy-benzimidazole, 2-cyanomethyl 6-nitro~benzimida~
zole, 2-cyanomethyl-5~methylsulphonyl-benzimidazole, benzimida~
zolyl-2-acetic acid amide, 2-ethyl-benzimidazole and 2-cyano-methyl-5-tri~Dluoromelhyl-benzlm.idazo].e. , The coupling is appropriately carrled out by adding the ~, .

lO~S~
tetrazohium solutiGn gradually to an aqueous or organic solu--tion of the coupling component~ at a pH value of 4-8 It is advantageous to adjust the pH value by adding a buffer Examples o~ buffers which can be used are the salts, particular-ly alkali metal salts, of formic acid, acetic acid or phos-phoric acid and tertiary nitrogen bases3 such as pyridine, trimethylamine, triethylamine or triethanolamine Furthermore, wetting, dispersing or emulsifying agents~ for example an aralkylsulphona~e, such as dodecylbenzenesulphona-te~
polycondensation products of ethylene oxides, such as the product of the reaction of ethylene oxide with p-tert -octyl-phenol, and also alkyl esters of sulphoricinoleates, for example n-butyl-sulphoricinoleate, can be added to the coupling ::
solution The coupling dispersion can also con-tain pro-tective colloids, for example methylcellulose or minor amounts of an inert organic solvent which is sparingly soluble or insoluble in water, for example halogenated or nitrated aromatic hydrocarbons, such as benzene, toluene, xylene, chlorobenzene, dichlorobenzene or nitrobenzene, and aliphatic :
halogenohydrocarbons, such as carbon tetrachloride or tri- .
chloroethylene, and also organic solvents ~ihich are miscible with water, such as acetone, methanol, ethanol, isopropanol, methyl ethyl ketone and dimethylformamide. -By virtue of their insolubility, the resulting pigments can be isolated from the reaction mixtures by filtration.
An after-treatment in an organic solvent, preferably a solvent .
boiling above 100C generally proves advantageous in order to ~ ' ', . :
: - 7 - .

~, .
.' ,. :

~0 ~ 5 obtain an excellent texture of these pigments. Solvents ~rhich are found to be particularly suitable are benzene deriva-tives substituted by ~alogen atoms or alkyl or nitro groups, such as xylene, chlorobenzene 5 o-dichlorobenzene or nitro-benzene, and pyridine bases, such as pyridlne, picoline or quinoline, and also ketones, such as cyclohexanone, ethers, such as ethylene glycol monomethyl ether or ethylene glycol monoethyl ether, amides, such as dimethylformamide, dimethyl-acetamide or N-methylpyrrolidone, and sulphoxane. m e - after-treatment is preferably carried out by heating the dried pigment in the solvent to 100-150C, in the course of which a `-homogeneous crystal structure is formed and, in many cases, there is a coarsening o~ grain, which has a ~a*ourable effect on the rheological behaviour and on the ~astness to migration and light of the resulting pigments.
The coupling can also be carried out advantageously by adding an acid solution o~ the tetrazonium salt slowly to an organic solution, buffered with a tertiary nitrogen base~ of the coupling component Suitable organic solvents are, in particular, water-miscible solvents, such as dimethylforma-mide, dimethylacetamide, N-methylpyrrolidone and dimethyl-sulphoxide or sulphoxone. This method of~ers the advantage that, after the coupling is completed, water and readily volatile solvents which have been added with the tetrazo component, can be distilled o~f and the after-treat-ment can be carried out in the coupling suspension The coupling can also be carried out by continuously - 8 - ~
, .
' ' . ....

1(~4~L%O
combining, in a mixing jet, an acid solution of the tetrazon-- ium sal-t with an alkaline solution of the coupling component, in the course o~ which an immediate coupling of the components takes place. The resulting colorant suspension is continuously withdrawn from the mixing jet and the colorant is isolated by ~iltration.
- Instead o~ the tetrazonium salts, it is also possible to use the corresponding tetraZOaminO compounds~ These are obtained by a known process by coupling an aryltetrazonium salt with 2 mols of a primary, or preferably a secondary, amine. The most diverse amines are suitable ~or this purpose, ~or example aliphatic amines, such as methylamine, ethylamine, ethanolamine, propylamine, butylamine, hexylamine - and, particularly, dimethylamine, diethylamine, diethanolamine, methylethanolamine, dipropylamine or dibutylamine, aminoacetic -acid, methylaminoacelic acid, butylaminoacetic acid, amino- -ethanesulphonic acid, methylaminoethanesulphonic acid, guanyl-ethanesulphonic acid or ~-aminoethylsulphuric acid, alicyclic amines, such as cyclohexylamine, N-methylcyclohexylamine or dicyclohexylamine, aromatlc amines, such as 4-aminobenzoic acid, sulphanilic acid, 4-sulpho-2-aminobenzoic acid, (4-~sulphophenyl)-guanidine, 4-N-methylaminobenzoic acid, 4-ethylaminobenzoic acid, l-aminonaphthalene-4-sulphonic acid or l-aminonaphthalene-2,4 disulphonic acid, heterooycllc amines, such as piperidine, morpholine, pyrrolidine or dihydroindole, ~; ~ and finally also sodium cyanamide or dicyandiamide.
As a rule, the resulting tetrazoamino compounds are :
~ ~ - 9 1~5~0 sparingly soluble in cold water and can, if appropriate, be isolated from the reaction medium in a crystalline form a~ter salting out In many cases the moist press cakes can be used for a further reaction. In individual cases it can be found appropriate to free the tetrazoamides from water by vacuum drying, prior to the reaction.
The coupling of the tetrazoamino compound with the -coupling component is carried out in an organic solvent, for example chlorobenzene, o-dichlorobenzene, nitrobenzene, pyridine, ethylene glycol, ethylene glycol monoethyl or mono-methyl ether, dimethylformamide, formic acid or acetic acid.
When solvents,which are miscible with water,are used, it is not necessary to use the tetraZOaminO compounds in an anhydrous form. ~or example, filter cakes which are ;~
moist with water can be used.
The coupling is appropriately carried out in a warm, acid medium, preferably at temperatures between 80 and 180C, and generally proceeds very rapidly and to completion I~
neutral solvents are used, it is advantageous to add an acid, for example hydrogen chloride, sulphuric acidg formic acid or !, acetic acid. By virtue of their insolubility, the resulting pigments can be isolated from the reaction mixturè
by ~iltration It is, therefore, unnecessary in most cases to carry out an after-treatment with organic solvents, such as is required in the case of pigments which are obtained by the aqueous coupling route Finally, the coupling can also be accomplished by - 10 - .`
- ~ , . : .
':

`

10~5~l2(~
suspending the diamine to be tetrazotised in an organic sol-vent together with the coupling component in a molar ratio of 1:2, and treating the suspension with a diazotising agent, particularly an ester of nitrous acid, such as methyl, ethyl, butyl, amyl or octyl nitrite, with nitrosylsulphuric acid or wi-th nitrosyl chloride.
The new colorants are valuable pigments which can be used in a finely divided form for pigmenting high molec-ular organic ma-terial, for example cellulose ethers and cellulose esters, such as ethylcellulose, nitrocellulose, cellulose acetate or cellulose butyrate, natural resins or synthetic resins, such as polymerisation resins or condensa-tion resins, for example aminoplasts, particularly urea-formaldehyde and melamine-formal~ehyde resins, alkyd resins, phenoplasts 9 polycarbonates, polyolefines, such as poly-styrene, polyvinyl chloride, polyethylene, polypropylene 7 polyacrylonitrile or polyacrylic acid esters9 polyamides, polyurethanes or polyes-tersl rubber, casein, silicone and . .
silicone resins, individually or as mixtures. -It is immaterial here whether the high molecular compounds mentioned are present in -the form of plastic com-positions or~melts or in the form of spinning solutions, lacquers or paints. Depending on the end use, it is found advantageous to use the new pigments as toners or in the form o~ preparations.
` By vlrtue of their high tinctorial strength and transparency, the new colorants are particularly suitable ` ~ 0 ~ 5 ~ 2~
for use in printing inks, such as in letterpress, gravure and offset printing.
CH-PS 522,713 describes a pigment which is obtained by coupling tetrazotised 1,5-diaminoanthraquinone with 2 mols -of 3-cyano-4-methyl-2,6-dihydroxypyridine. However, the colour of -this known pigment is indica-ted as blue, ~Ihile the pigment obtained in accordance with the invention from tetrazotised 1,5-diaminoanthraquinone and 2 mols of 3-cyano-

4-methyl-2,6-dihydroxypyridine, the struc-ture of which has been established by combustion analysis and mass-spectrum, gives an orange coloration. Compared wi-th the color-ants described in DAS 1,544,372, the pigments according to the invention are distinguished by a-particularly high tinc-torial strength and transparency in printing inks, and also by better fastness to light and migration.
In the examples which follow, unless otherwise speci-fied7 the parts denote parts by weight and the percentages -denote percentages by weight, Example 1 .
11.9 parts of 1,5-diaminoanthraquinone, in 150 parts ;
~by volume of glacial acetic acid and 30 parts by volùme of : 1:
concentrated hydrochloric acid, are stirred for several hours !, ~and are then cooled to 0 - 5C and are tetrazotised at this temperature with 25 parts by volume o~ 4N sodium nitrite solu-tion. ~he tetrazo solution is made up to a volume of 600 parts wlth ice and water and is clarified by ~il-tration.
18.5 parts of 1-ethyl-2-hydroxy-4-methyl-5-cyano-6-pyridone are - 12 _ ~ , ; ' ' ,.

~ 09~5~1l2~
dissolved in 1,000 parts by volume of dimethylformamide and 100 parts by volume of pyridine and the tetrazo solution is added dropwise over the course of 1 hour at 20 - 25C, whilst stirring well. After the addition of the tetrazo solution is completed, the mixture is stirred for 1 hour at room tempera-true and is then warmed to the boil. ~ater and acetic acid are distilled off until the internal temperature reached is 150C. The mixture is stirred for a further 4 hours at this temperature, the pigment being converted into a homo-geneous crystalline form. The mixture is then allowed to cool to 100C and is filtered and the precipitate is washed with dimethylformamide, warmed to 100C9 until a vir~
tually colourless filtrate issues. The precipitate is then washed with cold methanol and finally with water.
After drying in vacuo at 70 - 75C, a soft-grained pigment which dyes plastics and lacquers in brilliant orange shades, is obtained. The pigment corresponds to the formula ;
C~3 - ..

~ 2H5 O ~ ~ OHO ~ ~= O HO~y~ ~ o , 2 S ~ ~=N ~ -N

, m e table which follows lists further colorants which are obtained if -the diaminoanthraquinones mentioned in column I are tetrazotised and coupled, in accordance with instructions ` 1(~4S12~
` .
of Example 1, with the coupling components listed in column ; II. Column III indicates the shade of a 0.2% streng-th colora-tion achie ed using the colorant in PVC.

. :

, ;, .
'' ' .
., ~ .
: :.
- ~ ,. .

' '':
- ;~

~ ~ -,, , ' ` ` :
: , , ~ 4 ~ 1 20 ~ . . ~
: No. I ~ III
, . ~ . . . ~ _ _ _ _ ~ . , 2 1,5-diamino- 6-hydroxy-3-cyano-4-methyl-anthraquino-ne pyrid-2-one orange 3 ll 1-methyl-~3-cyano-4-methyl-6-. hydroxypyrid-2-one orange 4 n 1-propyl-~3-cyano-4-methyl-6-hydroxypyrid-2-one orange " 1-isopropyl~3-cyano-4-methyl-6-hydroxypyrid-2-one orange 6 1-n-butyl-3-cyano-4-methyl-6-hydroxypyrid-2-one orange :
7 n 1-benzyl-3 cyano-4-methyl-6-. hydroxypyrid-2-one bro~n -~
8 ll 6-hydroxy-4-me-thylpyrid-2-one orange 9 . 6-hydroxy-4-methyl-1-ethyl-pyrid-2-one orange :~
.. 6-hydroxy-4-methyl-1-n-butyl- .
. . . pyrid-2-one orange 11 n 6 hydroxy-L~methyl-3-carbon-amido-l-me-thylpyrid-2-one orange 12 n 6-hydroxy-4-methyl-3-carbon-amido-l-ethylpyrid-2-one orange 13 ~ 6-hydroxy-4-methyl-3-carbon-. . amidopyrid-2-one orange 1~ .1 6-hydroxy-4-methyl-3-carbon- :
: amido~ propylpyrid-2-one orange .. :
n 6-hydroxy-4-methyl-3-carbon- ~ :
amido-l-isopropylpyrid-2-one orange :
:16 " 6-hydroxy-~methyl-3-carbon- : -amido-l-n-butylpyrid-2-one orange 172,6-diamino- 6-hydroxy-3-cyano-4-methyl-anthraquinone pyrid-2-one yellow 18 n 6-hydroxy-3-cyano-l-~methyl-1- yellow-ethylpyrid-2-one orange : .
~ 19 n 6-hydroxy-3-carbonamido-4-: methyl-l-ethylpyrid~2-one yellow .

~ ~ ~ 15 : :

5~Z(~
_, _ . _ ~ ~
; No. I II III
___ ,, ,. . _ .-, 20 2,6-diamino- 6-hydroxy-3-carbonamido-4- I .
anthraquinone methyl-l--propylpyrid-2-one yellow 21 ,l 6-hydroxy-3-carbonamido-L~ yello~
methyl-l~isopropylpyrid-2-one orange 22 . " 6-hydroxy-3-carbonamido-4- ...
methyl-l-n-butylpyrid-2-one yellow , 23 " 6-hydroxy-3-carbonamido-4-. methyl-l-me-thylpyrid-2-one yellow :-24 ll 6-hydroxy-3-cyano-4-methyl~l- :
methylpyrid-2-one yellow " 6-hydroxy-~-cyano-L~methyl-l~ ~.
. propylpyrid-2-one . yellow 26 ll 6-hydroxy-L~methylpyrid-2-one yellow 27 n 6-hydroxy-L~methyl-l-ethyl- ...
pyrid-2-one yellow 28 n 6-hydroxy-4-methyl-1-n-butyl- .. ~
pyrid-2-one yellow ~-29 2,7-diamino- 6-hydroxy-4-methyl-3 cyano-l- yellow-::~
anthraquinone ethylpyrid-2-one orange 3o ~ 3-cyano-L~carbethox~-1,2- .~:.
(1',2')-benz-(4'~5')-imidaz-olo-6-hydroxypyrldine bro~n 31 2,6-diamino- 6-hydroxy-3-cyano-4-methyl-1-7-methyl- ethylpyrid-2~one yellow .
: an-thraquinone .
32 1,5-diamino- 3-cyano-L~phenyl-1,2-(1',2')-2,6-dimethyl- benz-(4!~5')-imidazolo-6-anthraquinone hydroxypyridine claret 33 2,6-diamino- 3-cyano-4-methyl-1,2-(1',2')- .
3,7-dibromo- benz-(4',5')-imidazolo-6-anthraquinone hydroxypyridine red : ~ 34 l~ 6-hydroxy~4-methylpyrid-2-one yellow 35 2,6-diamino- n : .
1,5-dichloro- .
anthraquinone brown . ., ~ 16 -~ ~4~2C) No I ! II III ¦ .
~ ~
36 2,6-diamino- 3-cyano-4-methyl-1,2-(lt 2')-1,5-dichloro- benz-(4',5')-imidazolo-6~
anthraquinone hydroxypyridine red 37 2,6-diamino- "
anthraquinone red 38 1,5-diamino- "
anthraauinone red 39 n 3-cyano-4-phenyl-1,2-(1',2l)- ..
benz-(4t,5~)-imidazolo-6- .
hydroxypyridine red ..
40 2,6-diamino- ,- ;
anthraquinone brown ~:
41 . " 3-c~ano-4-carbe-tho -1,`2-. (1' 27)-benz-(4',5 ~-imid- .
azo~o-6-hydroxypyridine beige 42 1,5-diamino- n : .:
anthraquinone . claret 43 1,5-diamino- CH
anthra~uinone C~ ~ . claret .

¦ ~ OH
C.~3 . : C~3 . l~3 ~:
- ~ ¦ l l C~3~ ¦ lare-t ; -CH3 :-: . . . ;' '' ': ' ",:

~ ; 7 ~.

~1,0451Z(l ___._ . ~ . . .
No. I II III
. - - . .
1,5-diamino-6-hydroxy-4-methyl-3-acetyl-an-thraquinone aminopyrid-2-one red 46 2,6-diamino- 6-hydroxy-3~cyano-4-methyl-1- yellow-xanthone ethylpyrid-2-one orange 47 1,5-diamino- 6-hydroxy-3-cyano-4-methyl-1-anthraquinone phenylpyrid-2-one orange 48 n 6-hydroxy-3-cyano-4-methyl-1-(4'-chloro)-phenylpyrid-2-one orange 49 n 6-hydroxy-3-cyano-4-methyl-1-(4 t -methyl)-phenylpyrid-2-one orange n 6-hydroxy-3-cyano-4-methyl-1-(4'-methoxy)-phenylpyrid-2-one orange ,'':
.. ~ ~ ~
65 parts of stabilised polyvinyl chloride, 35 parts of dioctyl phthalate and 0.2 part of the colorant obtained in accordance with Example 1 are stirred with one another and are worked on a twin-roll calender for 7 minutes at 140C. A pure orange_coloured sheet, wi-th very good fastness to light and migration, is obtained.
Example 52 1,00 g ofthep ~ ent prepared in accordance with Example 1 is finely ground on an Engelsmann grinding machine with ~.00 g of lithographic varnish having the composition:
29.4% of linseed oil stand oil (300 poises), 67.2% o~ linseed oil stand oil ( 20 poises), 2.1% of cobalt acetate (870 Co) and 1.3% of lead acetate and is then printed at 1 g/m on art printing paper in the ~ 5~ZO
letterpress process with -the aid of a blockO A deep shade of pure and glossy orange, having a very good trans-parency, is obtained.
The pigment is also suitable for o-ther prin-ting processes, such as gravure printing, o~fse-t printing and flexographic printing and gives excellent results in these ` applications too.

10 parts of titanium dioxide and 2 parts of a col-ouring substance prepared in accordance with Ex~mple 1 are ground for 48 hours in a ball mill together with 88 parts of -a mixture of 26.4 parts of coconut alkyd resin,2~0 parts of melamine-formaldehyde resin (50% solids content), 8.8 parts of ethylene glycol monomethyl ether-and 28.8 parts of xylene.
IP this Iacquer is sprayed onto an aluminium foil, dried at room temperature fcr 30 minutes and then stoved at 120C for 30 minutes, a brilliant orange-coloured lacquering which has a good gloss and which is disting~ished by very good stability to overlac~uering, light and weathering, is obtained. ;;
,, ~

~ ',:
- , ' ' - ' . '. ' ' - 19 -. ' "

Claims (9)

WHAT WE CLAIM IS:

1. A disazo pigment of the formula wherein R1 denotes a H atoms, an alkyl group which contains 1-4 C atoms and is optionally substituted by a phenyl radi-cal, or an aryl radical, R2 denotes a H atom, an alkyl group containing 1-4 C atoms, a cyano or carbamoyl group, or an alkanoylamino group containing 2-4 atoms, R3 denotes an alkyl group containing 1-4 C atoms, an alkoxycarbonyl group containing 2-6 C atoms, or a phenyl group which is optionally substituted by halogen atoms or alkyl or alkoxy groups containing 1-4 C atoms, Z denotes an O atom or a N
atom, the N atom forming, conjointly with the radical R1, a benzimidazole ring, X and Y denote H or halogen atoms or methyl or nitro groups, and V denotes an O atoms or a -CO-group.

2. A disazo pigment of the formula wherein R1, R3 and Z have the meaning indicated in Claim 1.

3. A disazo pigment of the formula wherein R1, R3 and Z have the meaning indicated in Claim 1.

4. The compound according to claim 1 of the formula

5. The compound according to claim 1 of the formula

6. The compound according to claim 1 of the formula

7. The compound according to claim 1 of the formula

8. Process for pigmenting high molecular organic mat-erial, characterised by the use of the pigments according to Claim 1.

9. High molecular organic material containing a pig-ment according to Claim 1.