Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is based on the observation
that colourations of outstanding fastness are obtained
in organic material of high molecular weight by using as
pigments disazo compounds of the formula
=N-CHCONH ~ NHCOCH-N-
Cl RO
wherein X represents a chlorlne atom, methyl or a tri-
fluoromethyl group and R represents an alkyl group of
1 to 3 carbon atoms, in a finely dispersed form.
Preferred disazo compounds are those of the indicated
formula wherein R represents an ethyl group and X repre-
sents a chlorine atom.
The disazo compound of the formula
N=N-CHCONH ~ NHCO-CH-N-
Cl C2H5 Cl
is also of particular interest.
The dlsazo colourants to be used according to the
lnvention are known compounds which are obtained by
coupling the diazo-component of an amine of the formula
X
~ NN~ ~
with a bisacetoacetyl-phenylenediamine of the formula
D ~
1~15~1
~R
CH3COCH2COHN ~ NHCOCH2COCH3
OR
in the molar ratio 2:1.
The following diamines may be cited as examples of
diazo components.
2,5-dichloroaniline and
2-methyl-5-chloroaniline.
The coupling components are obtained by reacting a
diamine of the formula
qR
2 ~ 2
R
wherein R has the indicated meanings, with diketene. The
following diamines may be cited as examples:
2,5-dimethoxy-1,4-phenylenediamine
2,5-diethoxy-1,4-phenylenediamine
2,5-dipropoxy-1,4-phenylenediamine
2,5-diisopropoxy-1,4-phenylenediamine
The coupling preferably takes place in a weakly
acid medium, advantageously in the presence of conventional
agents that promote the coupling. Such agents are in par-
tlcular dispersants, for example aralkylsulphonates, such
as dodecylbenzenesulphonate, or l,l'-dinaphthylmethane-
2,2'-disulphonic acid or polycondensation product,s of
alkylene oxides. The dispersion of the coupling component
can also
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advantageously contain protecti~e colloids, for exa~ple
methyl ceL~ulose or ~inor amounts of inert organic solvents
which are sparingly soluble or insoluble in water, for example
optionally halogenated or nitrated aromatic hydrocarbons, for
example, benzene, toluene, xylene, chlorobenzene, dichloro-
benzene or nitrobenzene, and also aliphatic halogenated hydro-
carbons, for example carbon tetrachloride or trichloro-
ethylene, as well as organic solvents which are miscible with
water, for example, acetone, ethylene glycol monomethyl ether,
methyl ethyl ketone, methanol, ethanol or isopropanol.
The coupling can also advantageously be carried out
by continuously combining an acid solution of the diazonium
salt with an alkaline solution of the coupling component in a
mixing nozzle, whereupon an immediate coupling of the component
occurs. Care must be taken that the diazo component and the
coupling component are present in equimolecular amounts in the
mixlng nozzle, although a slight excess of coupling component
proves to be advantageous. This is most simply accomplished
by controlling the pH of the liquid in the mixing nozzle.
Furthermore, intense turbulent mixing of the two solutions
in the mixing nozzle must be ensured. The resultant colourant
dispersion is continuously drawn off from the mixing nozzle
and the colourant separated by filtration.
Finally, the coupling can also be carried out by
suspending the diazo component with the coupling component in the
D -~-
i~15~1
molar ratio 2:1 in an organic solvent and treating the coup-
ling mixture with a diazotising agent, in particular with an
ester of nitrous acid, such as methyl, ethyl, butyl, amyl or
octyl nitrite.
The pigments usually precipitate at elevated temperature
and can be isolated in pure form by filtration and subsequent
removal of any impurities by washing them with an organic
solvent.
The pigments have in general a good texture and can be
widely used as crude products. If necessary or desired, the
crude products can be converted into a finely dispersed form by
grinding or kneading, advantageously using grinding assistants,
such as inorganic and/or organic salts in the presence or ab-
sence of organic solvents. After the grinding procedure, the
assistants are removed in the conventional manner: soluble
inorganic salts for example with water, and water-insoluble
assistants for example by steam distillation
The properties of the crude pigments can often be
improved by treating them with organic solvents, preferably
those having a boiling point above 100C. Particularly
suitable organic solvents are: benzenes which are substituted
by halogen atoms, alkyl ornitro groups, for example ~ylene,
chlorobenzene, o-dichlorobenzene or nitrobenzene, as well as
pyridine bases, such as pyridine, picoline or quinoline, and
also ketones, for example, cyclohexanone; ethers, for example
~_~
Bi~l
ethyl~ne glycol monomethyl and monoeth~l ether; amides, such as
dimethyl formamide or N-methylpyrrolidone, as well as dimethyl
sulphoxide or water under pressure.
The aftertreatment is effected preferably by heating
the pigment in ~he solvent to 100-150C, when in many cases an
increase in the granular size occurs. The fastness to light
and migration of the resultant pigments are thereby favourably
influenced.
Suitable material of high molecular weight comprises
preferably synthetic resins, for example cellulose ethers and
esters, such as acetyl cellulose, nitrocellulose, and amino-
plasts, in particular ureajformaldehyde and melamine/formal-
dehyde resins, alkyd resins, phenolic plastics, polycarbonates,
polyolefins, such as polystyrene, polyvinyl chloride, poly-
ethylene, polypropylene, polyacrylonitrile, polyacrylates.
Of particular interest are lacquers, for example those
based on alkyd/melamine/formaldehyde resins, alkyd/urea/
formaldehyde resins, as well as thermoplastic and thermocuring
acrylic resins.
The colourants to be used according to the invention
are also of great interest for use in printing inks.
The pigments of the present invention have good
dispersibility and thermostability. The colourations obtained
therewith are distinguished by good fastness to migration and
unu~ually good fastness to light and ~7ea~hering.
1~5~ 1
The disazo compounds to be used according to the
invention are described in par~ in German patent specification
~50,039. However, no mention at all is made therein of their
use as pigments.
Swiss patent specification 557,407 describes similar
disazo c~ourants which are used for pigmenting organic material
of high molecular weight. However, the colourations obtained
therewith have less good fastness to light and weathering.
The invention is illustrated by the following Examples,
in which the parts and percentages are by weight unless
otherwise indicated.
,
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Example 1
5.1 parts of 2,S-dichloroaniline are dissolved in
40 parts by volume of glacial acetic acid at room temperature.
The brown solution is stirred with 8 parts by volume of conc.
hydrochloric acid and the thick suspension which forms
(chlorohydrate) is diluted with 16 parts of water, cooled to
5C, treated dropwise in the course of 15 minutes and at 5C
with 8.3 parts by volume of 4N sodium nitrite solution and the
resultant brown diazo solution is filtered clear.
Subsequently, 5.5 parts of 2,5-diethoxy-1,4-bis-acetoacetyl-
aminobenzene are dissolved in 60 parts of water ~ith the addition of
7.5 parts by volume of 30% sodium hydroxide solution. The
pale yellow solution is treated at 5C in the course of 15
minutes with the above diazo solution, whereupon an orange
precipitate forms. The resultant suspension is adjusted to a
pH value of 5 by the slow addition of 26 parts of 30% aqueous
sodium hydroxide solution. It is stirred for 4 hour8 at a
temperature rising to 20C, diluted with 400 parts of water,
heated in the course of 1 hour to 75C and filtered hot by
suction. The residue is washed free of salt and dried in vacuo
at 60C, affording 10.14 parts (98% of theory) of a red powder
of the formula
i~15~
Cl &l
`N ~ ~ =N ~>
¦ O` ¦ Cl
CH3CO--CII-CO~H ~ I~HCO-CH-COCH~
C~H5
After an aftertreatment in N-methylpyrrolidone (1 hour at
162C), this pigment colours polyvinyl chloride in fast,
orange shades when incorporated thereinto on a roll mill.
The pigment also colours polyester resins in bright and very
fast orange shades.
nalysis: calculated: C 50.72 H 3.97 N 11.83 Cl 19.96%
found: C 50.5 H 3.9 N 12.1 Cl 19.8 %
The 2,5-diethoxy-1,4-bis~acetoacetylaminobenzene can be
prepared as follows: 9.8 parts of 2,5-diethoxy-1,4-phenylene-
diamine are heated in 100 parts by volume of glacial acetic
acid to 40C. The resultant brown solution is treated
dropwise in the course of 10 minutes with 8.5 parts of
diketene, whereupon the temperature rises to 73C and a beige
precipitate forms. The slurry is heated to 98C over the
course of 10 minutes, stirred for 1 hour at this temperature,
allowed to cool to xoom temperature, and the precipitate is
collected by suction filtration. The produ~ is washed with
40% acetic acid and then with cold water ana dried, affording
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14.9 p~rts (~1% of theory) of a pale yellow powder with a
melting pOillt of 214~-216~C.
nalysis: calclllated: C 59.33 H 6.64 N 7.69%
ound: C 59.2 H 6.6 N 7.7%
The following table lis~s further pigments which are obtained
by coupling the diazotised bases of column I with the bis-
acetoaceticarylides of the diamines of column II in the molar
ratio 2:1. Column III indicates the shade of polyvinyl chloride
sheeting which is coloured with 0.2% of these pigments.
f~
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Example II III
2 2-methyl-5- 2,5-diethoxy-1,4- yellowish
chloraniline phenylenediamine orange
3 2,5-dichloro- 2,5-dimethoxy- orange
aniline 1,4-phenylene-
diamine
4 2,5-dichloro- 2,5-dipropoxy- orange
aniline 1,4-phenylene-
diamine
2-methyl-5- ,. yellowish
chloroaniline orange
6 2,5-dichloro- 2,5-diisopropoxy- yellow
aniline 1,4-phenylenedi-
amine
Example 7
3.5 parts of 2,5-dichloroaniline and 3.6 parts of
2,5-diethoxy-1,4-bisacetoacetylaminobenzene are dissolved
at 50C in 200 parts of ethyl cellosolve and 20 parts of
glacial acetic acid. After cooling to room temperature,2.5
parts of tert-butylnitrite in 100 parts of dichlorobenzene
are added dropwise, whereupon the temperature ri~es to
40C and the pigment formation commences. The batch is
subsequently stirred for 2 hours at 40 to 50C and for 5
hours at 130 to 140C, in thecourse of which the colourant
assumes a homogeneous crystalline form. Microscopic exami-
nation reveals orange crystalline aggregates having a
-- 11 --
1~15~1
length of 5 to 10 ,u. After filtration at 140C, washing
with hot dichlorobenzene until the filtrate runs colour-
less, expelling the dichlorobenzene by methanol and
finally washing with hot water and drying, 6 parts of an
orange pigment are obtained.
Example 8
0.2 g of the pigment obtained in Example 1 and 100 g
of polystyrene granules are mixed and processed on a roll
mill at 130C until the colouration appears homogeneous.
The composition is then pressed between chromed plates to
sheets. The orange colouration of the sheets is of good
lightfastness. The pigmentation can also be carried out in
an extruder instead of on a roll mill. In addition, it is
also possible to granulate the homogeneously pigmented
composition and to mould it in an injection moulding
machine.
Example 9
0.2 g of the pigment prepared in accordance with
Example 1, 1 g of titanium dioxide (rutile) and 100 g of
polyethylene granules are mixed in a drum mixer and the
mixture is subsequently processed on a roll mill at
130C. The composition ls pressed hot to sheets or formed
ln an extruder. The sheet~ have a fine orange shade of
excellent lightfastness.
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Example 10
0.1 g of the pigment prepared in accordance with
Example 1, 0.5 g of titanium dioxide (rutile) and 100 g of
polypropylene granules are mixed in a drum mixer and the
mixture is subsequently processed on a roll mill at 130C
until it is homogenously coloured. The composition ls
pressed hot to rough sheets of 1 mm. These sheets have a
fine orange shade of good lightfastness.
Example 11
100 g of a formaldehyde/urea resin in powder form
which is suitable for moulding materials, 10 g of lithopone
and 1 g of the pigment prepared in accordance with Example
1, are ground for 16 hours in a ball mill. The composition
is subsequently pressed at 140-160C into moulds. The
orange samples have good lightfastness and heat resistance.
Example 12
24.5 g of an unesterified epoxide resin, 10.5 g of
an oil-reactive alkylphenol resin, 35 g of xylene and 30 g
of diacetone alcohol are processed to a lacquer and ground
for 24 hours ln a ball mill with 4 g of the pigment
obtaln~d accordlng to example 1. After spraying on~o
alumlnlum sheets and stovlng at 120C, orange coatlngs of
very good fastness to heat, overstripe bleeding and light
are obtained.
D
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Example 13
Acrylic resin stoving enamel
4 parts of the finely divided pigment of Example 1
are stirred into 20 parts of solvent of the following
composition: 50 parts of Solvesso 150 !mixture of aromatic
carbons), 15 parts of butyl acetate, 5 parts of Exkin II
(levelling agent based on ketoxime), 25 parts of methyl
isobutyl ketone and 5 parts of silicone oil (1 % in
Solvesso 150). After complete dispersion has been attained
(in approx. 15 to 60 minutes, depending on the type of
stlrrer), the following binders are added: 48.3 parts of
8aycryl L 530 (acrylic resin; 51 % in xylene/butanol 3:1)
and 23.7 parts of Maprenal TTX (melamine resin; 55 % in
butanol). After brief homogenisation, the lacquer is
applled by conventional methods, such as spraying and
immersing, or in the coil coating method specially for the
continuous coating of metal sheets, and stoves ~stoving
for 30 minutes at 130C). The orange finishes are
distinguished by very good levelness, high gloss and
excellent fine distribution of the pigment as well as by
excellent weather fastness properties.
Example 14
4 g of the pigment obtained according to Example 1,
35 g of a 60 % solution of an alkyd resin, modified with
urea/formaldehyde, in xylene/butanol 1:1, 10 g of oil of
terpentine and 5 g of xylene, are ground for 48 ~ours in
a ball mill. After spraying the resultant coloured lacquer
onto an aluminium sheet and stoving at 120C, an orange
finish of very good fastness to light, heat and overstripe
bleeding is obtained
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D
1~5~1
Example 15
80 g of an unsaturated liquid polyester resin,
19.72 g of monostyrene and 0.28 g of a cobalt siccative
which contains 16 ~ of cobalt, are ground for 48 hours-
in a ball mill with 1 g of the pigment obtained according
to Example 1 and 5 g of titanium dioxide ~rutile).
Shortly before the application of this lacquer, a mixture
consisting of 4.15 g of cumene hydroperoxide (70 %), 2.42 g
of ethyl acetate and 13.33 g butyl acetate is added. Card-
board is coated with this mixture and dried in the air to
give an orange coating of very good fastness to light, heat
and overstripe bleeding.
Example 16
67 g of polyvinyl chloride powder (suspension
polymer), 33 g of dioctyl phthalate, 2 g of dibutyl tin
dilaurate, 0.3 g of a stabiliser on phosphate basis and
0.7 g of the pigment prepared according to Example 1,
are mixed and processed for 15 minutes at 160C on a roll
mill. Subsequently a sheet having a thickness of 0.4 mm
is prepared on the calender. It is coloured ln a bright
orange shade which is heat-reslstant and fast to migra-
tlon.
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.,;
i',
