Note: Descriptions are shown in the official language in which they were submitted.
5 ~ 2~
It has been found that a new valuable disazo pigment
of the formula
COOC1~3 lOOC~3
CO~II ~ NHOC
Cl
is obtained when a) a carboxylic acid hali.de of the formula
. ~OCll3
~ ~' ' '-"'~
~ COHal
wherein Hal denotes a halogen atom, is condensed with 4-
chloro-1,3-phenylenediamine in the molar ratio of 2-1 or ~)
the diàzo compound of anthranilic acid methyl ester is
coupled with the bis-naphthol o~ the formula
~ OH HO
- : .
~ ~ in the molar ratio o~ 2:1. .
...
: ~ The:azo colorant-carboxylic acid on which the acid :;i
halide used as :the starting material is based, is obtained by i :
.
: coupling diazotised anthranilic acid methyl ester with 2~3- ~
- : .. ;
~ 2 _ ~ ~
~51~1 '
hydroxynaphthoic acid.
The azo colorant-carboxylic acid obtained is treated
with agents which are able to conver-t carboxylic acids to
their ha]ides, for example the chlorides or bromides, in
particular with phosphorus halides, such as phosphorus
i ~ pentachloride or phosphorus trichloride or phosphorus penta-
bromide, phosphorus oxyhalides and, pre~erably, thionyl
chloride.
The treatment with such acid-halogenating agents is
suitably carried out in inert organic solvents, such as
dimethylformamide, chlorobenzenes, ~or example monochloro-
~
benzene or dichlorobenzene, toluene, xylene or nitrobenzene,in the case of the 5 last-mentioned solvents with addition of
dimethylformamide if necessary. When manufacturing the
carboxylic acid halides it is advisable ~irst to dry the azo
compound which has been manufactured in an aqueous medium, or
to free it azeotropically from water by boiling in an organic
solvent~ This azeotropic drying can, if desired, be carried ;
out immediately prior to the treatment with the acid-
halogenating agents.
The condensation of the carboxylic acid halide,
especially the carboxylic acid chloride, with the diamine is
preferably carried out in an anhydrous medium. It is
carried out at temperatures which lie within the boiling range
of normal organic solvents, such as toluene, monochloroben-
zene, dichlorobenzene, trichlorobenzene, nitrobenzene and the ;
like. To accelerate the reaction it is advisable to use an
- - ' .,' '.
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- 3 - ;~
~ , . ~';'
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.
10~5~
acid~bindi~g agent, such as anhydrous sodium acetate or
pyridine. I~here a very pu~e pigmen-t is desired i-t is
advisable to isolate the acicl chloride, obtained ~rom the
azo-carboxylic acid, be~ore reacting it with the diamine.
For numerous purposes, however, a pigment in -the manufacture
o~ which an isolation of the acid chloride has been dis-
pensed with and the condensation with the amine is carried
out immedia-tely following the manufacture of the carboxylic
acid chloride, is sufficiently pure.
Instead of the pure 4-chloro-1,~-phenylenediamine it
is also possible to use mixtures thereof with other m-
phenylenediamines, especially 1,3-phenylenediamine. By
doing so, improvements in the tinctorial properties of the
pigments can be achieved.
The coupling according to an embodiment b) of the
process according to the invention is suitably carried out by
gradual addition of the aqueous alkaline solution of the
coupling component to the acid solution of the diazonium
salt. The amount of alkali metal hydroxide to be used for
dissolving the coupling component is suitably so chosen that
it su~fices to neutralise the mineral acid liberated from the
diazonium salt during coupling. The coupling is advan-
tageously carried out at a pH value of 4 to 6. The pH va~ue ~;
is advantageously adjusted by addition of a buffer.
Examples of buffers which can be used are the salts,
especially the alkali metal salts, of ~ormic acid or phos- ;~
phorio acid or especially of acetic acid. The alkaline ~
' ' .
- 4 - ~ ~
1045~Z~
solution OI the coupling component preferably contains a
wetting agent, dispersing agent or emulsifier, for example
an aralkylsulphonate, such as dodec~lbenzenesulphonate, or
the sodium salt o~ l,l'~naphthylmethanesulphonic acid, po]y-
condensation products of alkylene oxides, such as the reac-
tion product of ethylene oxide with p-tert~-octylphenol,
or alkyl esters of sulphoricinoleates, for example n-butyl
sulphoricinoleate. The dispersion o~ the coupling component
can also advantageously contain protective colloids, for
example methylcellulose or minor amounts of inert, sparingly
water-soluble or water-insoluble organic solvents, for
example optionally halogenated or nitrated aromatic hydro~
carbons, such as benzene, toluene, xylene, chlorobenzene~
dichlorobenzenes or nitrobenzene, as well as aliphatic
halogenohydrocarbons, such as, for example, carbon tetra-
chloride or trichloroethylene, and also water-miscible
organic solvents, such as acetone, ethylene glycol monomethyl
i
ether, methyl ethyl ketone~ methanol, ethanol or isopropanol.
The coupling can advantageously be carried out by
combining an acid solution of the diazonium salt continuously
with an alkaline solution of the coupling component in a
mixing nozzle, whereupon immediate coupling of the components
takes place. Care must be taken that the diazo component
and coupling component should be present in equimolecular
amounts in the mixing nozzle, a slight excess of coupling
component proving advantageous. This is most simply
effected by control].ing the pH value of the liquid in the ;;~
: . .
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~ 5 _ ~
.. ..
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5~
mixing nozzle. Vigorous intermixing o~ the two solutions
in the mixing nozzle must also be ensured. The resulting
colorant dispersion is continuously withdrawn from the
mixing nozæle and the colorant is isolated by flltration.
Finally, the coupling can also be carried out by
suspending the amine which is to be diazotised, together
with the coupling component, in the molar ratio of 2:1, in an
organic solvent and treating the suspension wi-th a diazo-
tising agent, especially an es-ter o~ nitrous acid, such as
methyl nitrite, ethyl nitrite, butyl nitrite or amyl nitrite.
~ y virtue of their insolu~ ty, the pigments
obtained can be isolated from the reaction mixtures by fil-
tration. Since the by-products remain in solution, the
resulting pigments are obtained in excellent purityO An
a~ter-treatment with organic solvents is indicated for pig-
men-t obtained by the aqueous coupling method. A further
advantage of the process according to the invention is the
high yield, the advantageous form, from thè point of view of
pigments technology, and the constancy of properties of the
pigment obtained.
The new colorant is a valuable, orange pigment, which ;
~can be used, in a finely dlvided form, for pigmenting high
molecular organic material, for example cellulose ethers and
cellulose esters, such as ethylcellulose, nitrocellulose,
cellulose aoetate and cellulose butyrate, polyamides, poly- ~
urethanes or polyesters, natural resins or synthetic resins, ;
such as polymerisation resins or condensation resins, for
. . ..
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~ 5121
example aminoplasts, especially urea-formaldehyde and mela-
mine-formaldehyde resins, alkyd resins, phenoplasts, poly-
carbonates, polyolefines, such as polystyrene, polyvinyl
chloride, polyethylene, polypropylene, polyacrylonitrile and
polyacrylic acid esters, rubber, casein, sillcone and
silicone resins, individually or as mixtures.
It is immaterial whether the high molecular compounds
mentioned are in the form of plastic masses, melts or spinning
solutions, lacquers, paints or printing inks. Depending on
the end use, it proves advantageous to use the new pigments
as toners or in the form of prepa;ations.
The colorations obtained with the pigment according
to the invention are distinguished by great depth o~ colour
and brilliance, and fastness to light and to migration.
.
Compared to the nearest comparable state of the art,
namely the colorant described in Example 1 o~ the table of
DL-PS 61,580, the colorant according to the invention is ;
distinguished by better ~astness to migration and to light.
In the examples which ~ollow the parts, unless
stated otherwise, denote parts by weight and the percentages
denote percentages by weight. ;
Example 1
'~0 parts o~ the colorant which is obtained by
coupling diazotised l-aminobenzene-2-carboxylic acid methyl ~-
~-ester with 2,3-hydroxynaphthoic acid are warmed, in a finely ;
divided ~orm in a mlxture o~ 308 parts o~ o-dichlorobenzene
and 30.2 parts o~ thion~l chloride, to 95C over the course o~ ;
_
~: : "
~ ~ ~ 5 ~ Z ~
one hour, while stirring. The reaction mixture is then kept
at 95-100C ~or 10 minutes. After cooling to 20C, the azo
colorant-carboxylic acid chloride which has precipi-tated in a
crystalline form is isolated by filtratlon, rinsed with a
little o~dichlorobenzene and then with benzene, and dried in
vacuo at 70C.
36.85 parts of the carboxylic acid chloride thus
obtained are dissolved in 650 parts of o-dichlorobenzene a-t
i 100C, while stirring. A solution, at 120C) which contains
7.13 parts of 4-chloro-1,3-diaminobenzene in 260 parts of o-
dichlorokenzene is added to the preceding solution in the
course of 3 minutes. The mixture is stirred for 16 hours at
140~145C. The condensation product formed is ~iltered off
at 100C, rinsea first with o-dichlorobenzene at 100C and
then with methanol at 20C, and dried in vacuo at 100C.
The organic pigment obtained is an orange powder which is
sparingly soluble in organic solvents and which, when brough~
to a fineiy divided state, colours polyvinyl chloride sheets - ~
in brilliant orange shades of good fastness to migration and --
to light.
Element~y analysis of the organic pigment obtained.
C H Cl N 0
found % 65.2 3.7 4.3 10.5 15.6
. . .
- calculated % 65.47 3.844~40 10.42 15.87
Example 2 (one-pot process)
35 parts of the colorant which is obtained by coup-
ling diazotised l-aminobenzene-2-carboxyllc acid methyl ester
~: 8
~ ' ' ' ,..... '
1~)45~2~
wi-th 2,3--hydroxyrlaphthoic acid are warmed, in a ~inely
divided form in a mixture of ~30 par-ts of o-dichlorobenzene
and 15.1 parts of thionyl chloride, to 95C over the course
o~ one hour, while stirring. The reaction mixture is then
kept at 95-100C for 10 minutes~ The excess thionyl
chloride is now distilled off together with 65 parts of o-
dichlorobenzene, under a slight vacuum. To this carboxylic
acid chloride solution, at 100C, is added, over the course
o~ 3 minutes, a solution which contains 7.13 parts of 4-
chloro-1,3-diaminobenzene in 130 parts of o-dichlorobenzene
and is at 120C. The mixture is stirred ~or 16 hours at
140-145C~ The condensation product formed is filtered off
at 100C and worked up as described in Example 1. The
organic pigment obtained is substantially identical with that
described in Example 1.
..
Exam~ (alkyl nitrite process) ~; -
3.1 parts of 1-aminobenzene-2-carboxylic acid me-thyl
ester and 4.83 parts of bis-[2'-hydroxy-3'-naphthoyl]-4-
chloro-1,3-diaminobenzene are introduced into 145 parts of
dimethylformamide, while stirring, and 10 parts o~ glacial
acetic acid are added. The suspension is stirred for 30
minutes at 20_30C. A mixture o~ 10 parts of dime~h-yl~orm-
amide and 2.6 parts of tert.-butyl nitrite is now added d;lop-
wise over the course o~ 15 minutes at 20-30C. The diazo~
tisation and coupling take place at the ~ollowing tempera-
tures: 2 hours at 20-30C, 1 hour at 40-45C and 1 hour at
60-65C. Thereafter, 50 parts are distilled off in vacuo at
- _ 9 _ .
~ S ~ 2~
: 60-70C, so as to free the pigment from the glacial aceticacid. The pigment suspension is now warmed at 120-130C for
3 hours. The product is filtered off at 100C, rinsed first ~:
with dimethylformamide at 100C, then with methanol at 20C
and then with water at 80C, and is finally dried in vacuo at
100C. The organic pigment obtained is substantially ~ ~
identical in shade with that described in Example 1. .
Example 4 (diazoamino process) .
5.6 parts of the diazoamino compound of the formula
H3C-OOC
. . ~ NCN-N H 0
(prepared by coupling diazotised l-aminobenzene-2-carboxylic ..
acid methyl ester with morpholine in an alkaline medium) and ;
4.83 parts of bis-[2'-hydroxy-3'-naph-thoyl]-4-chloro-1,3- ~-
diaminobenzene are suspended, while stirring, in 260 parts of
1,2-diehlorobenzene and the suspension is warmed to 60C.
20 parts of glacial acetic acid are now added and the whole
is warmed to 120-130C for 2 hours. . After this time, the :
splittlng of the diazoamino compound and the coupling are . -
eomplete. The orange pigment is filtered off at 100C,
rinsed with hot 1,2-dichlorobenzene at 100C and then with
methanol at 20C and with water.at 80C and finally dried in
:- vacuo at 100C. The organic pigment obtained is substan-
tially identical in shade with tha-t described in Example 1.
(batch coupling)
6.1 parts o~ 1-aminobenzene-2-carboxylic acid methyl
'.
' ' ' ' "" .';:
~L~)45~Z~ ;
ester are diazotised in the usual manner at ~0-5C.
At +5-10C -the diazo solution is added, over the
course of ~5 minutes, to a solution of 200 parts of water, 10
parts of ~0% strength sodium hydroxide solu-tion and 9.65
parts of bis-[2 t -h~droxy-3'-naphthoyl]-4-chloro-1,3-diamino-
benzene. During the entire coupling period the pH value
should be 12-1~ and is maintained continuously by means of
dilute sodium hydroxide solution.
After coupling is complete, the mixture is s-tirred
for a further 30 minutes at 10C. The red-orange pigment is
now brought to pH 2 with hydrochloric acid. The suspension
is warmed -to 60C and is kept at 60-65C ~or 30 minutes.
The pigmen-t, which is obtained in a good ~orm, is filtered
off warm, washed with water un-til neutral and dried in a
vacuum cabinet at 60-70C. ;
The optimum use form is prepared by recrystallisa-tion
from nitrobenzene or other solvents bolling above 170C.
The organic pigment obtained is substantially identical in
shade with ~that described in Example 1.
Example 6 (nozzle coupling)
31.7 parts of 1-aminobenzene-2-carboxylic acid methyl
ester are dlazotised in the usual manner with 2 parts o~
acetic acid, 100 parts by volume of hydrochloric acid (30%
strength), ice and 52.5 parts by volume o~ 4 N sodium nitrite
solution at +0-5C, and the mixture is filtered.
Separately, 48.3 parts of bis-[2'-hydroxy-3'-naphthoyl]-
4-chloro-1,3-diaminobenzene are dissolved in 200 parts by
, :~
: . . .
iL~)9LS121
volume o-f me-thano~, ]00 parts by volume of sodium hydroxide
solution (30% strength) and 200 parts of water, whilst stir-
ring, and the solution is filteredu
The two solutions, if necessary adjusted to the same
volume by dilution with water, are fed continuously -to a
mixing nozzle where immediate coupling of the components takes
place. The flow speed of the solution which is regulated to
ensure that the pH value in the mixing nozzle is between 4.5
and 5Ø The temperature should be between 20 and 30C~
The colorant susFension produced is filtered and the filter -''
resldue is washed thoroughly with water.
The water-moist press cake is dehydrated azeotropically
with 800 par-ts of nitrobenzene and the mixture is then boiled '' '
for 2 hours under reflux. The product is filtered off at 100C,
washed first with hot ni-trobenzene and then with methanol and '-'
wa-ter and dried at 100C in a vacuum drying cabinet.
~ le organic pigment obtained is substantially identical
in shade with that described in Example 1. ' ~
Example I (co-condensation) "
36.85 parts of azo colorant-carboxylic acid chloride
described in Example 1 are dissolved in 650 parts of o-di-
. .
chlorobenzene at 100C, whilst stirring. A solution, at 120C, ~';
which contains 3.57 parts of 4-chloro-1,3-diaminobenzene and 2-.7 ''
parts of 1,3-diaminobenzene in 260 parts of o-dichlorobenzene ' ~'
is added to'the preceding solution over the course of 3
': ., -
minutes. The pigment prepared in this way is condensed, and
worked up, analogously to the method described in Example 1~
~. .. .
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~ ~4S~
The organic pigment obtained is an orange powder which
is sparingly soluble in organic solvents and which, when
brought to a ~inely divided state, colours polyvinyl chloride
sheets in brilliant orange shades o~ good fastness to mig- .
ratioD and to light. The pigment is substantially identical
in shade with that described in Example 1. ;
To shift the shade towards more red or more orange,
-the ratios of the l,~-diaminobenzenes employed may be varied
between 10:90 and 90:10.
Example 8 (co-condensation)
35 parts of the colorant which is obtained by coup-
llng diazotised l-aminobenzene-2-carboxylic acid methyl ester
with 2,3-hydroxynaphthoic acld are warmed, in a finely
divided form in a mixture of 390 parts of o-dichlorobenzene
and 15.1 parts of thionyl chloride, to 95C over the course
of one hour, while stirring. The reaction mixture is then
kept at 95-100C for 10 minutes. The excess thionyl
chloride is now distilled off together with 65 parts of o-
dichlorobenæene~ under a slight vacuum. To this carboxylic
acid chloride solution, at 100C, is added, over the course ;~
of 3 minutes, a solution which contains 4.3 parts of 4-chloro-
1,3-diaminobenzene and 2.16 parts of 1,3-diaminobenzene in
130 parts of o-dichlorobenzene and is at 120C. The mixture
~is stirred for 16 hours at 140-145C and worked up as des-
cribed in Example 1. The organic pigment obtained is sub~
stantially identical with that described in Example 1.
To shift the shade towards more red or more orange,
. -
. : ~ ',''
3 ~
,
~ O~SlZ~
the ratios o~ the 1,3-diaminobenzenes employed may be varied
between 10:90 and 90:10.
xample 9
o. 6 g of the pigment prepared according to Example l
are mixed with 67 g of polyvinyl chloride, 33 g of dioctyl
phthalate, 2 g of dibutyl-tin dilaurate and 2 g of titani~
dioxide and the mixture is processed for 15 minutes on a roll
mill at 160C, to give a thin sheet. The orange colouration
thus produced is deep, and fast to migration, heat and light.
Examp]e lO
1~ g of titanium dioxide and 2 g of the pigment
prepared according to Example l are ground for 48 hours in a
ball mill with 88 g of a mixture of 26.4 g of coconut alkyd
resin, 24.0 g of melamine-formaldehyde resin (50% solids
content), 8.8 g of ethylene glycol monomethyl ether and
28.8 g of xylene.
If this lacquer is sprayed onto an aluminium foil,
pre-dried for 30 minutes at room temperature and then stoved
for 30 minutes at 120C, an orange lacquering is obtained
which has good depth of colour and is distinguished by good ;
~astness to overlacquering and to light.
Example ll
2 g of the pigment prepared according to Example l
are ground on a triple roll mill with 36 g of hydrated alumina,
60 g of linseed oil varnish of medium viscosity and 2 g of
cobalt linoleate. The orange prints produced with the
colour paste obtained are deep and have good fastness to light.
: ~ 14 ~ ~
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