Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Reexamination Certificate
2000-02-14
2002-06-11
Green, Anthony (Department: 1755)
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
C106S493000, C106S494000
Reexamination Certificate
active
06402828
ABSTRACT:
The invention relates to a pigment composition which comprises azo pigments and auxochromes, a process for the preparation of the composition by coupling an aromatic diazonium compound with 3-hydroxy-2-naphthoic acid, a process for toning an azo lake pigment composition and the use of auxochromes with azo lake pigments.
Azo pigments produced by using 3-hydroxy-2-naphthoic acid as a coupling component are known and particularly useful. For example, they include Pigment Red 57:1 and Pigment Red 48:2. These azo pigments find a diversity of applications and are mainly used to colour printing inks, paints, oil and water colors, plastics and cosmetics. There is a wide range of requirements expected from the pigments used in these applications. For example, a high degree of brilliance and transparency is required for printing inks; durability and hiding power for paints; and heat resistance for plastics. Due to the diversity and extent of these requirements, there is a high demand for pigment compositions which contain known and well-established azo pigments, but permit a wide range of uses according to the intended fields of application.
There is a specific need for improving the toning of azo lake pigment compositions. The term toning, as used in the context of the instant specification, means the control and improvement of properties, such as hue and brilliance.
Brilliance, transparency or hiding power of a pigment composition can be intensified by applying physical methods, such as varying the fineness, form, shape and surface properties of the pigment particles.
The prior art also proposes alternative routes for achieving these goals. It has been recommended to modify the chemical structure of a small amount of pigment in the composition. This can either be achieved by modifying the structure of the 2-hydroxy-3-naphthoic acid. These chemically modified additives present in pigment compositions may be defined as auxochromes. According to EP-A-202 906, the carboxy group in the 2-hydroxy-3-naphthoic acid coupling component is derivatised to an amide or to a substituted amide. According to EP-A-259 007, part of the 2-hydroxy-3-naphthoic acid is replaced with binaphthol.
It is also known to add an auxochrome to azo pigments such as Pigment Red 57:1 in order to obtain shading and depth effects. Auxochromes for Pigment Red 57:1 to obtain blue shading effects have been produced by coupling Tobias acid (2-amino-1-napthalenesulfonic acid) onto 2-hydroxy-3-naphthoic acid. However, the resulting blue shade products still appear “dirty”.
Therefore, the object of this invention was to provide azo lake pigment compositions with an improved quality of shading. Preferably, the masstone, particularly for heatset applications, and transparency of the ink in an oil ink system should be improved.
Accordingly, the claimed pigment composition has been found wherein the auxochrome component of the pigment compositions can be prepared by coupling a 2-hydroxy-3-naphthoic acid component with a phenyl amine component, wherein the phenyl group is substituted by at least one C
1
-C
4
-alkoxy substituent, particularly methoxy.
The present invention relates to a pigment composition which comprises at least one pigment of the formula:
wherein X represents hydrogen or a cation from a metal selected from calcium, barium, strontium, magnesium, manganese and aluminium, R
1
, R
2
and R
3
represent hydrogen or members from the group consisting of C
1
-C
4
-alkyl, phenyl, halogen, —NO
2
and —CF
3
, and R
4
is as defined as R
1
, R
2
and R
3
or represents a group of the partial formula
wherein X′ is as defined as X above and R
1
′, R
2
′ and R
3
′ are as defined as R
1
, R
2
and R
3
under the formula (I) above, and at least one auxochrome of the formula
wherein X″ is as defined as X under the formula (I) above, at least one of R
5
, R
6
, R
7
, R
8
and R
9
represents C
1
-C
4
-alkoxy and R
5
, R
6
, R
7
, R
8
and R
9
independently of one another additionally represent members selected from the group consisting of hydrogen, C
1
-C
4
-alkyl, phenyl, halogen, —SO
3
—H, —NO
2
and —CF
3
and R
7
additionally represents a group of the partial formula
wherein X′″ is as defined as X under the formula (I) above, R
5
, R
6
, R
8
and R
9
are as defined as R
5
, R
6
, R
7
and R
8
under the formula (II) above.
A preferred embodiment of the present invention relates to a composition, which comprises at least one pigment of the formula (I), wherein X represents hydrogen or a cation from a metal selected from calcium, barium, strontium, magnesium, manganese and aluminium and R
1
, R
2
, R
3
and R
4
represent hydrogen or members from the group consisting of C
1
-C
4
-alkyl, phenyl, halogen, —NO
2
and —CF
3
, and an auxochrome of the formula (II), wherein X is as defined under the formula (I) above, at least one of R
5
, R
6
, R
7
, R
8
, and R
9
represents C
1
-C
4
-alkoxy and R
5
, R
6
, R
7
, R
8
, and R
9
independently of one another additionally represent members selected from the group consisting of hydrogen, C
1
-C
4
-alkyl, phenyl, halogen, —SO
3
—H, —NO
2
and —CF
3
.
A particularly preferred embodiment of the present invention relates to composition, which comprises at least one pigment of the formula
wherein R
1
and R
2
are different, R
1
represents hydrogen, C
1
-C
4
-alkyl or halogen and R
2
represents C
1
-C
4
-alkyl or halogen and X represents hydrogen or a cation from a metal selected from calcium, barium, strontium, magnesium, manganese and aluminium, and an auxochrome (II).
Particularly preferred is a composition, which comprises a pigment (I′), wherein R
1
and R
2
are different, R
1
represents hydrogen, methyl or chloro and R
2
represents methyl or chloro, and an auxochrome (II).
Especially preferred is a composition, which comprises Pigment Red 57:1 and an auxochrome (II) such as an auxochrome obtained by the coupling of ortho-nitro-para-anisidine (ONPA), para-cresidine-orthosulphonic acid (PCOS) or para-nitro-ortho-anisidine (PNOA) with 2-hydroxy-3-naphthoic acid (BONA).
The present invention also relates to compositions comprising preferred auxochromes. In this context a composition is particularly preferred, which comprises at least one pigment (I) and an auxochrome of the formula
wherein X″ is as defined as X under the formula (I) above and R
7
represents hydrogen or —NO
2
.
In the pigment composition according to the present invention, the amount of auxo-chrome (II) added to the pigment (I) is from about 0.01 to 10.0%, particularly 0.1 to 5.0%, and especially 0.2 to 2.0% by weight based on the weight of the pigment.
The present invention also relates to a composition, which comprises at least one pigment of the formula (I) of above, an auxochrome of the formula (II) of above and the coupling product of 2-napthylamine-1-sulphonic acid (Tobias acid) with the coupling component (V), particularly 2-hydroxy-3-naphthoic acid.
The pigment composition according to the present invention usually is prepared by methods which are known per se, e.g. by diazotising in situ an aromatic amine and coupling the resulting aromatic diazonium compound with 3-hydroxy-2-naphthoic acid.
The present invention also relates to the process for the preparation of the pigment composition, which comprises diazotising at least one amine of the formula
wherein R
1
, R
2
and R
3
are as defined above and R
4
is as defined as R
1
, R
2
and R
3
or represents a group of the partial formula
wherein R
1
, R
2
and R
3
are as defined as R
1
, R
2
and R
3
above; and at least one amine of the formula
wherein at least one of R
5
, R
6
, R
7
, R
8
, and R
9
represents C
1
-C
4
-alkoxy and R
5
, R
6
, R
7
, R
8
, and R
9
are as defined above and R
7
additionally represents a group of the partial formula
wherein R
5
′, R
6
′, R
8
′ and R
9
′ are as defined above, and coupling the diazotised amines (III) and (IV) with a coupling component of the formula
wherein X is as defined above under formula (I).
The process for preparing t
Chisholm Greig
Kerwin Paul
Nicol Mairi
Ciba Specialty Chemicals Corporation
Crichton David R.
Green Anthony
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