POLYAMIDES MASS COLOURED WITH DIKETOPYRROLOPYRROLE PIGMENTS

POLYAMIDES COLORES AVEC DES PIGMENTS DE DICETOPYRROLOPYRROLE

English Abstract

Mass-coloured synthetic polyamide containing, as pigment, at least one
diketopyrrolopyrrole pigment of formula
<IMG>
wherein A and B are each independently of the other a radical of formula
<IMG>

2
wherein Q is a -CONH2 group,
m is 1 or 2,
R1 and R2 are each independently of the other hydrogen, Cl, Br, CH3 or C2H5,
R3 is hydrogen, CH3, C2H5 or phenyl,
X is a direct bond, -O-, -S-, -SO2-, -CH=CH-, -CH2- or -C(CH3)2-, and
Y is -O- or -S-.
Polyamides mass-coloured with the pigments useful in the practice of this
invention have
exceptional heat stability and excellent lightfastness.

Claims

-11-
What is claimed is:
1. Mass-coloured synthetic polyamide containing, as pigment, at least one
diketopyrrolopyrrole pigment of formula
<IMG>
wherein A and B are each independently of the other a radical of formula
<IMGS>
wherein Q is a -CONH2 group,
m is 1 or 2,
R1 and R2 are each independently of the other hydrogen, Cl, Br, CH3 or C2H5,
R3 is hydrogen, CH3, C2H5 or phenyl,
X is a direct bond, -O-, -S-, -SO2-, -CH=CH-, -CH2- or -C(CH3)2-, and

-12-
Y is -O- or -S-.
2. A polyamide according to claim 1, containing as pigment at least one
diketopyrrolopyr-
role pigment of formula I, wherein A and B are identical and are a radical of
formula
<IMGS>
wherein X is a direct bond or -O-.
3. A polyamide according to claim 1, containing as pigment at least one
diketopyrrolopyr-
role pigment of formula I, wherein A and B are identical and are a radical of
formula
<IMGS>

Description

~12~~~~'.~
-1-
HW/P-19626/A
Polyamides mass coloured with diketopyrrolop ry role pigments
The present invention relates to the mass colouration of synthetic polyamides
with
diketopyrrolopyrrole pigments containing carbamoyl groups.
The mass colouration of synthetic polyamides makes greater demands of the
colourants
than the mass colouration of other plastic materials. The melting points of
synthetic
polyamides are very much higher and also the chemical reactivity of the fused
polyamides, especially of polyamide 66, is substantially greater, so that the
colourants
employed must have extremely good heat stability. There are few pigments that
meet
these exacting demands, particularly if superior lightfastness is additionally
required.
Compared with other known diketopyrrolopyrrole pigments as disclosed, inter
alia, in
US patents 4 415 685 and 4 579 949, the diketopyrrolopyrrole pigments
containing
carbamoyl groups used in the practice of this invention for colouring
synthetic polyamides
do not have any exceptional properties when used for colouring other plastic
materials.
Surprisingly, however, it has been found that they have an unexpectedly
enhanced heat
stability and quite outstanding lightfastness when used for colouring
synthetic polyamides.
Accordingly, the present invention relates to mass-coloured synthetic
polyamide
containing, as pigment, at least one diketopyrrolopyrrole pigment of formula
A O
W
HN NH
O B
wherein A and B are each independently of the other a radical of formula

~~_2~2
-z-
Q
(~, m
X > >
m R~ R3
R2
/ ~ \ /
O , ~ O , or
\ ~' N
Q
O
i
wherein Q is a -CONH2 group,
m is 1 or 2,
Rl and R2 are each independently of the other hydrogen, Cl, Br, CH3 or C2H5,
R3 is hydrogen, CH3, C2H5 or phenyl,
X is a direct bond, -O-, -S-, -S02-, -CH=CH-, -CH2- or -C(CH3)2-, and
Y is -O- or -S-.
particularly suitable diketopyrrolopyrrole pigments of formula I are those
wherein A and
B are identical and are a radical of formula
CONH2
X ~ ~ CONH2
CONH2 ~ ~ ~ CONH2
/ ~ \
or
wherein X is a direct bond or -O-.

-3-
Preferred diketopyrrolopyrrole pigments are those of formula I, wherein A and
B are
identical and are a radical of formula
or ~ ~ CONH2.
CONH2
The pigments useful in the practice of this invention can be prepared by
methods
analogous to standard known ones, conveniently by treating compounds of
formula I,
wherein Q is CN, with concentrated sulfuric acid.
Synthetic polyamides which may suitably be used in the practice of this
invention are
those that may typically be prepared from e-caprolactam (Perlon~, Nylon~ 6),
from
cn-aminoundecanoic acid (Rilsan~), from hexamethylenediamine and adipic acid
(Nylon~
66), or from analogous starting materials. Also suitable are copolyamides,
typically of
E-caprolactam and hexamethylenediamine and adipic acid.
The eligible pigments are blended with the polyamide by known methods in solid
form or
in suspension, and the blend so obtained may be subjected to an intermediate
drying.
It is preferred to coat the polyamides to be coloured, which are in the form
of powders;
granules or chips, with the dry pigment in powder form, i.e. to blend them
mechanically
such that the surface of these polyamide particles is coated with a layer of
pigment. The
pigment is conveniently in finely divided form. Instead of using the pure
pigment, it is
sometimes also possible to use with advantage preparations that comprise, in
addition to
the pigment, a heat-stable carrier that is compatible with polyamide,
preferably a calcium
or magnesium salt of a higher fatty acid, typically of stearic or behenic
acid, and also
polyethylene, polystyrene, polyesters and, naturally, polyamides or a mixture
thereof.
Such earners are disclosed, inter alia, in US patents 4 093 584 and 4 279 802,
GB patent 1 398 352 and CH patent 599 322. These granular preparations can be
mixed
with noncoloured polyamide granulate and further processed.
The polyamide particles coated with pigment are fused and spun or otherwise
shaped by
known methods to films or other moulded articles such as injection moulded
parts

~1282~~ ~
-4-
(engineering plastics).
The pigment can also be incorporated in the fused polyamide before the melt is
distributed
to the spinnerets (injection process) and the coloured polyamide is thereafter
spun or
shaped.
The coloured polyamide preferably contains 0.01 to 10 % by weight, preferably
0.1 to 3 %
by weight, of an eligible pyrrolopyrrole pigment of formula I.
The uniformly coloured objects so obtained are distinguished by superior
fastness to light,
shampooing, wet treatments, rubbing, chlorine, dry cleaning and, in
particular, by superior
heat-resistance, in certain cases by a high 1R remission and also by good
textile properties
such as tear strength and elongation or, in the case of moulded parts, by good
dimensional
stability.
Owing to their good distribution in the polymer melt, the pigments suitable
for use in the
practice of this invention are uniformly and finely distributed in the
coloured material.
The invention is illustrated by the following Examples in which, unless
otherwise
indicated, parts are by weight.
Example 1: With stirring, 10 parts of the dry ground pigment of formula
NC
CN
are charged at room temperature to 100 parts by volume of concentrated
sulfuric acid
(96 %). The dark red solution that forms within 10 minutes is stirred for 16
hours at room

2)..2~?~~v',
-5-
temperature and then poured onto 800 parts by volume of ice (bulk volume). The
resultant
suspension is stirred with the toothed disc until the ice has completely
melted and is then
filtered. The residue is washed with water until neutral, suspended in 240
parts by volume
of N-methylpyrrolidone and recrystallised by heating for 6 hours to
175°C while
simultaneously removing water by distillation. The crystals are isolated by
filtration,
washed with methanol and lyophilised, giving 8.5 parts (78 % of theory) of the
pigment of
formula
HZNOC
CONH2
Analysis: C H N
calcd: 64.17% 3.77% 14.97%
found: 64.34% 3.90% 14.55%
Example 2: 10 parts of the dry ground pigment of formula

-6-
CN
21~~~~~~~
are charged at room temperature to 100 parts by volume of concentrated
sulfuric acid
(96 %). The dark red solution that forms within 15 minutes is stirred for 18
hours at room
temperature and then poured onto 800 parts by volume of ice (bulk volume). The
resultant
suspension is stirred with the toothed disc until the ice has completely
melted and is then
filtered. The residue is washed with water until neutral and subsequent drying
gives
parts (92 % of theory) of the pigment of formula
CONH2
CONH2

~\
~~.~~~~~~i
_7_
Anal C H N
calcd: 62:66% 3.94% 14.61 %
found: 62.75% 4.39% 14.76%
Example 3: 5 parts of the dry ground pigment of formula
CN
CN
are charged at room temperature to 100 parts by volume of concentrated
sulfuric acid
Q96 %). The bluish-violet solution that forms within 30 minutes is stirred for
18 hours at
room temperature and then poured into 400 parts by volume of ice/water. The
resultant
suspension is stirred with the toothed disc until the ice has completely
melted and is then
~liltered. The residue is washed with water until neutral and subsequent
lyophilisation gives
4.3 parts (82 % of theory) of the pigment of formula

~'\
~~2~2~:~
_g_
12
Analysis: C H N
calcd: 71.76% 4.33% 10.46%
found: 71.55% 4.50% 9.99%
Example 4: 2 parts of the dry ground pigment of formula
CONH~

-9-
CN
CN
are charged at room temperature to 40 parts by volume of concentrated sulfuric
acid
(96 %). The violet solution that forms within 30 minutes is stirred for 22
hours at zoom
temperature and then poured onto 600 parts by volume of ice (bulk volume). The
resultant
suspension is stirred with the toothed disc until the ice has completely
melted and is then
filtered. The residue is washed with water until neutral and subsequent drying
gives
2.15 parts (99 % of theory) of the pigment of formula

2~~~~f:~'Y
- lo-
Example 5: The pigment is synthesised as described in Example 1. The filter
residue is
likewise washed with water until neutral, suspended in 160 parts by volume of
N-methylpyrrolidone and recrystallised by heating for 6 hours in an autoclave
to 260°C.
The crystals are isolated by filtration, washed with water and dried, giving
5.5 parts (50 %
of theory) of the same pigment as in Example 1 in coarse crystalline form.
Exam~Ie 6: 975 parts of polyamide 66 (~Ultramid AS 2500 S supplied by BASF AG)
are
mixed dry in powder form with 25 parts of the pigment of Example 1 and the
mixture is
vacuum dried. The polymer so treated is fused at 280-295°C in an
extruder and spun to
filaments. The orange filaments have superior lightfastness.
CONH2

Representative Drawing