Note: Descriptions are shown in the official language in which they were submitted.
The pr~sent invention relates to the new brown ~-
modification of a disazo pigment. Wher~as in the range
of blue, green and red pigment dyes, organic pigments
satisfying the most stringent requirements with respect
to fastness properties had been discovered relatively
early9 a much longer time was needed before organic
brown pigments having very good fastness properties were
able to be produced. This became possible ? as is shown
for example from the two Swiss Patent Specifications Nos.
434,520 and 561,258, by virtue of the use of diazotised
nitrochloro- or trichloroanilines as diazo components.
Pigments of this type, which in themselves are doubtlessly
of a very high quality, have however, in view of the
environmental protection regulations now in force, a
serious disadvantage as a result of the manner in which
they are produced: nitrochloro- and trichloroanilines
can be diazotised only by the use of nitrosylsulfuric
acid or glacial acetic acid, a procedure with which are
associa~ed considerable ecological problems, which can
be overcome only witl grea~ difficulty and by very
expensive means. Furthermore, the pigments produced with
nitrochloroanilines tend to deflagrate when being ground.
In the German Offenlegungsschrift No. 2,361,433, is
described in Example 1 the production of a reddish-brown
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7~ 1 ~
disazo pigment of the formula (I3
Cl
Cl
~ H ~ (I)
by condensation of the azocarboxylic acid chloride of
the formula (II) Cl
N~l -
~ COCl (II),
in the molar ratio o 2:1, with 1,5-diaminonaphthalene
in o-dichlorobenzene, in which process the 1,5-diamino-
naphthalene, dissolved in o-dichlorobenzene, is added to
a solution at 110C of the carboxylic acid chloride of the
formula (II) in o-dichLorobenzene; and the mixture is
subsequently heated for 18 hours at 145C. The resulting
dyeg in the production of which the aforementioned
ecological difficulties do not occur, has indeed good
fas~ness properties, but is of little colouristic interest
on account of its dull shade. The X ray diffracti.on
diagram of this pigment, which is ~o be denoted in the
ollowing as the a~modification, is characterised by
the following lines:
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Tnterplanar spacing or Intensity of the
d-value in ~ line
. . . _
10.8 very strong
9.5 medi~m
6.9 medium
4-9~ strong
4.74 medium
4.32 strong D*
4.09 medium D*
3.67 medium
3.23 very strong
3.14 medium
* D = diffused,
and in the range of 11.0 to 3.1 ~ there occ~ur further
-~ weak lines, namely at the following d-values:
7.8 4.0 3.95 3.87 3.73 3.63 3.33 and 3.17 ~ .
It has now been found that there is surprisingly
obtained a new valuable, deeply coloured, neutral-
.brown crystal modifi.cation of the dye of the formula
(I), called the ~-modification, the X~ray diffraction
spectrum of which is characterised by the following lines:-
InterplanarOspacing or Intensity of the line
lO.S very strong
6.5 medium
: 6.2 very strong
5.24 medium
4.78 medium
4.33 medium
4.14 medium
3.67 s~rong
3-45 strong
3.38 strong
~7~ 8
3.30 very strong
3.26 medium
3.16 medium
and in the range of 11.0 to 3.1 ~ there appear further
weak lines, namely at the following d-values:
` 17.2 3.5 and 3.22 ~ ,
by a process comprising adding undissolved 1,5-di~mino-
naphthalene, optlonally together with a catalytic amount
of a tertiary amine, especially pyridine, at room
temperature to a suspension of the carboxylic acid
chloride of the formula (II) in an inert organic solvent,
heating the mixture obtained, and completing the
condensation reaction at elevated temperature.
An improvement in the fastness to migration is
obtained by the addition o catalytic amounts of pyridine.
It was also found that, surprisingly, the same new
crystal modification, called ~-modification, is obtained
by heating the a-modification of the pigment of the
formula (I) in an inert high-boiling organic solvent.
Organic solvents boiling above 200C are preerred,
par~icularly nitrobenzene.
The X-ray diffraction diagrams were obtained by a
customary powder method, whereby the diffraction pat~ern
was recorded on films. A Guinier-DeWolff No. 2 camera
with CuKa radiation (~ = 1.5418 R) was employed The cali-
bration substance used was a-~quartz with d-values from
the ASTM File No. 5-0490. The intensity was estimated
visually and dlvided into four steps: very strong /
strong / medium / weak.
The new pigment modification is suitable, in the
inely dispersed form, for dyeing high-molecular, organic
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material of natural or synthetic origin. The materials
can be for example natural resins, drying oils or
rubber. They can however be modified natural substances,
for example chlorinat~d rubber, oil-modified alkyd
resins or viscose, or cellulose derivatlves such as
cellulose acetate and nitrocellulose, and particularly
fully synthetic organic polyplasts, i~e. plastics
produced by polymerisation, polycondensation and poly-
addition. Examples which may be mentioned of this class
of plastics are in particular the following: polyethylene,
polypropylene, polyisobutylene, polystyrene, polyvinyl
chloride, polyvinyl acetate, polyacrylonitrile, poly-
acrylates and polymethacrylates; polyesters, especially
high-molecular esters of aromatic polycarboxylic acids
with polyfunctional alcohols; polyamides; the condensation
products of formaldehyde with phenols, the so-called
phenoplasts, and the condensation products of formaldehyde
with urea, thiourea and melamine, the so-called amino-
plasts; the polyesters used as lacquer resins, that is
both saturated resins, for example alkyd resins, and
unsaturated resins, for example maleic resins, and also
the polyaddition or polyco~densation products of epichloro-
hydrin with polyols or polyphenols~ known under the name
of "epoxide resins'l; and also the so-called thermoplasts,
i.e. the thermoplastic polyplasts. It is to be emphasised
that not only the homogeneous compounds but also mi~tures
of polyplasts, as well as co~condensates and co-
polymerisates, for example those based on butadiene,
can be pig~ented with the pigment modification according
~o the invention.
It is in this respect irrelevant whether or not ~he
high-molecular compounds mentioned are in the form of
plastic mi~tures or of melts, or in the form of spinning
7 ~ ~
solutions, lacquers, coating materials or prin~ing
inks or pastes. Depending on the purpose of application,
it proves advantageous to use the pigment modification
according to the invention either as a toner or in
the form of preparations.
The pigment modification according to the invention
is distinguished by its depth of colour, by good
fastness to heat, light, weather, overlacquering,
rubbing, solvents and migration, and by good dispers-
ibility.
Except where otherwise stat~d in the following
Examples, the term 'parts' signifies parts by weight7
percentages are per cent by weight, and the temperature
values are given in degrees Centigrade.
' ~
Flxample 1
72.2 parts o~ the azo dye obtained by coupling
cliazotised l-amino-2,5-dichlorobenzene with 2,3-
hydroxynaphthoic acid are heated, finely dispersed
in admixture with 520 parts of o-dichlorobenzene, with
stirring to 85. There is subsequently added dropwise
at 80-90, in the course of 10 minutes, 32.7 parts of
thionyl chloride, and the reaction mixture is further
heated and held at 115-120 for 60 minutes. It is cooled
to 20, and the azo dye carboxylic acid chloride, which
has precipitated in crystalline form, is isola~ed by
filtration, washed with a small amount of o-dichloro-
benzene and then with petroleum ether, and dried at
70 in vacuo.
37095 parts of the azo dye carboxylic acid chloride
thus obtained are stirred with 650 parts of anhydrous
o-dichlorobenzene at 20-25 for 15 minutes. To the fine
suspension are added 2.5 parts of pyridine and 7.9 parts
of l,5~naphthylene diamine, and the mixture is heated
and stirred for 15 hours at 140-145. The condensation
product which has precipitated is filtered off at 100,
and washed firstly with o-dichlorobenzene at 100, then
with methanol at 20 and subsequently with water at 80.
It is finally dried in vacuo at 100 to yield 39.4 parts
(93~ % of theory) of the pigment dye of the formula (I),
of which the X-ray diffraction spectrum is identical to
that which in the specification characterises the ~-
modification. The resulting pigment dye of the ~-modifi-
cation is a brown powder very difficultly soluble in
organic solvents. It dyes PVC and lacquers in neutral,
deeply coloured shades of brown which have very good
fastness ta migration, light, weather, overlacquering
and heat.
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Elementary~ nalysis of the pigment dye obtained
C H Cl N 0
% found: 62.3 3.2 17.0 9.8 7.5
% calculated: 62.5 3.1 16.~ 9.9 7.6
Example 2 (Direct process)
36.1 parts of the azo dye obtained by coupling
diazotised l-amino-2,5-dichlorobenzene with 2,3-hydroxy-
naphthoic acid are heated, finely dispersed in admixture
with 700 parts of anhydrous o-dichlorobenzene, with
stirring to 85. There is subsequently added dropwise
at 80-90, in the course of 10 minutes, 16.4 parts of
thionyl chloride. The reaction mixture is heated and
held at 115-120 for 60 minutes. The unreacted thionyl
chloride, together with 50 parts of o-dichlorobenzene,
is then distilled of under a slight vacuum. The azo dye
carboxylic acid chloride which has formed is cooled to
20~ and 2.5 parts of pyridine and 7.9 parts of 1,5-
naphthylenediamine are immediately added. The red sus-
pension is heated and stirred at 140-145 for 15 hours.
The bro~n pigment which has formed is filtered off at lOQ,
and processed as described in Fxample 1 to yield 40,3
parts (95.6 % of theory) of the pigment dye of the
formula (I), of which,the ~-modifica~ion (characterised
~y X-ray diffrac~ion spec~rum), the shade of colour and
the fastness properties are ~he same as those o the
pigment dye of Example,l. ' ' '
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Example 3
Conversion of the ~-modification into the ~-modification
. _
Five parts of the disazo pigment, obtained according
to Example 1 of the German Offenlegungsschrift No.
2,361,433 by condensation of the azo dye carboxylic
acid chloride, in the molar rato of 2.2 : 1, with 1,5-
naphthylenediamine on o-dichlorobenzene, are boiled
in 180 parts of nitrobenzene with stirring for 3 hours.
After cooling to 100, the pigment is filtered off, and
washed firstly with a small amount of nitrobenæene at
100, then with methanol at 20 and dried at 100 in vacuo.
The yield is 4.6 parts of a brown soft pigment powder
corresponding to the ~-modification. The pigment is
converted by grinding or salt kneading into a form
favourable for application, and in this form dyes polyvinyl
chloride sheets in brown shades; it has the properties
mentioned in Example 1. A longer treatment with nitro-
benzene does not lead to any modification change. The
~-modification is therefore stable. For the conlersion
into the ~-form, it is also possible to use other solvents
boiling above 200, such as l-chloronaphthalene.
Example 4
65 parts of polyvinyl chloride, 35 parts of dioctyl-
phthalate and 0.2 part of the pigment obtained according
to Example 1 are mixed ~ogether, and then rolled backwards
and forwards for 7 minutes at 140 on a two-roller calender to
obtain a neutral brown-dyed sheet which has a deep shade
of colour and very good fastness to light, weather,
migration and overlacquering.
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Example 5
40 parts of a nitrocellulose lacquer, 2.375 parts
of titanium dioxide and 0.125 part o~ the pigment obtained
in Example 1 are ground for 16 hours in a bar mil].
The lacquer resulting is applied in a thin layer to an
aluminium sheet. A neutral brown lacquer coating having
excellent fas~ness properties is obtained.
Example 6
A mixture of 25 parts of the pigment obtained
according to Example 1, 25 parts of cellulose acetate
(34.5% of bound acetic acid), lOO parts of sodium
chlori~e and 50 parts of diacetone alcohol is treated
in a kneader, with cooling, until the desired degree of
fineness of the pigment is achieved. An addition of 25
parts of water is subsequently made and kneading is
continued until a fine-granular mixture has been formed.
This is transferred to a suction filter and washed with
water until no further chlorine ions are detectable in
the ~iltrate. The material is dried at 85 in vacuo and
afterwards ground in a hammer mill.
1.33 par~s of the pigment preparation obtained are
added to an acetate rayon spinning solution consisting
of 100 parts of cellulose acetate and 376 parts of
acetone. Stirring is maintained for 3 hours to effect
the complete dispersion of the dye. The filament obtained
from this solu~ion in the usual way after the drying
operation displays a neutral brown dyeing having very
good fastness properties.
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Example 7
0.25 part of the dye according to Example 1 is
ground with 40 parts of an alkyd-melamine stoving
lacquer, which contains 50%of so~ds,and 4.75 parts
of titanium dioxide for 24 hours in a bar mill. The
lacquer obtained is applied in a thin layer to an
aluminium sheet, and stoved for one hour at 120. The
result is a brown lacquer coating having good fastness
to light and to weather.
~xample 8
4.8 parts of the dye according to Example 1 are
ground with 4.8 parts of the sodium salt of 1,1'-
dinaphthylmethane-2,2'-disulfonic acid and 22.1 parts
of water in a customary colloidal mill until all
pigment particles are smaller than 1 ~. The resulting
pigment suspension has a pigment content of about 15%.
If this aqueous suspension is added to the viscose
spinning solution, there is obtained by the usual spinning
process a cellulose filament which is dyed neutral brown
and which has very good fastness properties.
Example 9
A stabîlised mixture of 100 g of a suspension polyvinyl
chloride ("Hostalit C 260", Hoechst AG, K value = 60~,
1.5 g of a complex formed from barium salts and cadmium
salts of higher fatty acids, complexing agents and
antioxidants, as stabiliser ('IAdvastab B C 26", CIBA-
GEIGY AG, Basle)~ 0.5 g of a co-stabiliser based on
organic phosphite compounds (~'Advastab CH 300", CIBA-
GEIGY AG, B~sle), 3.0 g of an epoxidised soyabean oil
("Advaplas~ 29", CIBA-GEIGY AG, Basle), 0.5 g of a lubricant
~,
("E-Wachs", BASF AG, Ludwigshafen)~ 2.0 g of titani~n
dioxide KRONUS Cl 220", Titangesellschaft GmbH~ Lever-
kusen) and ~.1 g of the pigment according to Example 1
is processed for 8 minutes at 180 on mixing rolls
with a roll velocity of 20:24 (friction 1:1.2) and a
roll gap of 0.3 mm, and subsequently moulded to form
a 1 mm plastics sheet. The brown dyeing of the rigid
polyvinyl chloride sheet has excellent fastness to
rubbing, heat, migration, light and weather.
Exampl.e 10
A printing ink is ob~ained from 10 g of the pigment
according to Example 1, 30 g of aluminium hydroxide and
60 g of a lithographic varnish produced on a linseed~
- oil/stand oil base, using a three-roll mill.
The printings obtained therewith in the letterpress
printing process are distinguished by a beautiful bro~rn
shade`having excellent fastness to light and very good
fastness to solvents and to overlacquering.
_am~le 11
A stabilised mixture of 65 g of an emulsion polyvinyl
chlo;ide having a K value of 72-74 ("Lonza GD", Lcnza AG,
Basle), 32 g of dioctylphthalate, 3 g of an epoxidised
soyabean oil as pla.sticiser ("Advaplast 39", Ciba Geigy
~G, Basle), 1.5 g of a complex, formed from~fatty-acid
~ barium salts and cadmium salts, complexing agents and
antioxidants, as stabiliser ('`Advastab B C 26", CIBA-GEI~Y
AG, Basle), 0.5 g of a co-s~abiliser based on organic
phosphite compounds ("Advastab CH 300", Ciba Geigy AG,
Basle), 5 g of titanium dioxide ("Titandioxid KRONUS RN
56", Titangesellschaft GmbH, Leverkusen) and 0.5 g of the
. pigme~t according to Example 1 is processed for 8 minutes
;iK ~ 0/ ,~,
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at 160 on mixing rolls with a roll velocity of 20:24
(friction 1:1.2) and a roll gap of 0.3 mm. The brown
dyeing of the soft polyvinyl chloride sheet obtained
in this manner has very good fastness to migration,
rubbing, heat and light.
Example 1.2
A stoving lacquer formed from 20 g of titanium
dioxide (for example "Titandioxid KRONUS RN 57",
Titangesellschaft GmbH, Leverkusen), 40 g of a 60%
solution of a coconut oi~ alkyd resin (copolycondensate
from coconut oil fatty acid, phthalic acid and pentaery-
thritol) in xylene, 24 g of a 50% solution of a melamine
B resin (for example "Superbeckamin 852", Reichhold-Chemie,
- Hamburg) in butanol, 8 g of xylene, 7 g of ethylene
gl.ycol monomethyl ether and 1 g o~ the pigment according
to Ex~mple 1 is finely ground in a ball mill; it is then
sprayed onto an aluminium sheet, allowed to dry and
subsequently stoved at 120 for 30 minutes. The brown
dyeing has very good fastness to weather, overlacquering
- and heat.
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