Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Reexamination Certificate
2000-12-22
2002-12-17
Green, Anthony J. (Department: 1755)
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
C106S494000, C106S495000, C546S049000, C546S056000
Reexamination Certificate
active
06494948
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a process for the preparation of quinacridone pigment compositions in the presence of mixtures of certain sulfonyl-containing derivatives of 2,5-dianilinoterephthalic acid.
Processes for the preparation of quinacridone are known. E.g., S. S. Labana and L. L. Labana, “Quinacridones” in
Chemical Review,
67, 1-18 (1967); W. Herbst and K. Hunger,
Industrial Organic Pigments,
2nd ed. (New York: VCH Publishers, Inc., 1997), pages 454-459; and U.S. Pat. Nos. 3,157,659, 3,256,285, and 3,317,539. The quinacridones thus obtained, known as crude quinacridones, are generally unsuitable for use as pigments and must undergo one or more additional finishing steps to modify the particle size, particle shape, or crystal structure to achieve pigmentary quality. For example, in a preferred method for preparing quinacridones, certain 2,5-dianilinoterephthalic acid precursors are thermally ring closed in the presence of polyphosphoric acid. E.g., U.S. Pat. No. 3,257,405. After ring closure is complete, the melt is drowned by pouring into a liquid in which the quinacridone is insoluble, usually water and/or an alcohol, after which the resultant crystalline pigment is typically further conditioned by solvent treatment and/or milling.
The addition of certain quinacridone derivatives or their precursors to the ring-closure step has been reported to enhance the coloristic and rheological properties of quinacridone pigments. For example, U.S. Pat. No. 5,368,641 discloses the use of various quinacridone derivatives in the manufacture of 2,9-dimethylquinacridone, U.S. Pat. No. 5,457,203 describes the use of quinacridone derivatives during the oxidation of dihydroquinacridone (prepared from 2,5-dianilino-3,6-dihydroterephthalic acid) to quinacridone, and U.S. Pat. Nos. 5,683,502 and 5,713,999 disclose the manufacture of quinacridone pigments in the presence of compounds other than quinacridones.
U.S. Pat. No. 5,755,873 describes the preparation of quinacridone pigments by ring closure of the corresponding dianilinoterephthalic acid precursors in the presence of various substituted dianilinoterephthalic acid derivatives, including 2,5-di(sulfamoylanilino)terephthalic acid. Although the resultant quinacridone pigment compositions typically exhibit improved coloristic and rheological properties, the quinacridone derivative that forms when using 2,5-di(sulfamoylanilino)terephthalic acid has an undesirable tendency to bleed from the resultant pigment preparations, which can adversely affect their use.
It has now been found that quinacridone pigment compositions exhibiting an advantageous combination of coloristic and rheological properties without excessive bleeding associated with 2,5-di(sulfamoylanilino)terephthalic acid can be obtained by using reduced quantities of 2,5-di(sulfamoylanilino)terephthalic acid in combination with other sulfonyl-containing derivatives of 2,5-dianilinoterephthalic acid during quinacridone synthesis.
SUMMARY OF THE INVENTION
The present invention relates to a process for the preparation of quinacridone pigment compositions comprising
(a) heating, at a temperature of about 80° C. to about 145° C. (preferably 95° C. to 130° C.) (preferably for about one to about 24 hours), a reaction mixture comprising
(i) 2,5-dianilinoterephthalic acid or 2,5-dianilino-6,13-dihydroterephthalic acid or a derivative of 2,5-dianilinoterephthalic acid or 2,5-dianilino-6,13-dihydroterephthalic acid having one or more substituents other than sulfonyl groups in at least one aniline ring, a salt or ester thereof, or a mixture thereof,
(ii) about 0.1 to about 5 percent by weight (preferably 1 to 3 percent by weight), based on component (a)(i), of a 2,5-di(sulfamoylanilino)terephthalic acid having the formula (I)
and/or a 2,5-di(sulfamoylanilino)-6,13-dihydroterephthalic acid having the formula (I′)
wherein W
1
and W
2
are independently hydrogen, halogen,
C
1
-C
6
alkyl, or C
1
-C
6
alkoxy,
(iii) about 0.1 to about 15 percent by weight (preferably 5 to 10 percent by weight), based on component (a)(i), of one or more sulfonyl-containing derivatives of 2,5-dianilinoterephthalic acid having the formula (II)
and/or one or more sulfonyl-containing derivatives of 2,5-dianilino-6,13-dihydroterephthalic acid having the formula (II′)
wherein
X
1
and X
2
are independently OR
a
or NR
b
R
c
,
Y
1
and Y
2
are independently hydrogen, halogen, C
1
-C
6
alkyl, or C
1
-C
6
alkoxy,
R
1
and R
2
are independently hydrogen, a metal, an ammonium ion, or C
1
-C
12
alkyl,
R
a
is hydrogen, a metal, an ammonium ion, or C
1
-C
12
alkyl,
R
b
is hydrogen, C
1
-C
12
alkyl or substituted C
1
-C
12
alkyl, C
5
-C
7
cycloalkyl or substituted C
5
-C
7
cycloalkyl, C
6
-C
10
aryl, heteroaryl having five or six ring atoms (in which at least one such ring atom is N, O, S, or a combination thereof, and which is optionally fused to one or more additional aromatic rings), or C
7
-C
16
aralkyl,
R
c
is hydrogen, C
1
-C
12
alkyl or substituted C
1
-C
12
alkyl, C
5
-C
7
cycloalkyl or substituted C
5
-C
7
cycloalkyl, or C
7
-C
16
aralkyl, or R
b
and R
c
together with the nitrogen atom form a heterocycle having 5 to 7 ring atoms, and
m and n are independently from 0 to 3, with the provisos that
(1) at least one of m or n is not 0 (preferably where both m and n are 1),
(2) if X
1
and X
2
are both NH
2
, then either (A) at least one of Y
1
or Y
2
must be halogen, C
1
-C
6
alkyl, or C
1
-C
6
alkoxy or (B) Y
1
must be different from W
1
and/or Y
2
must be different from W
2
(i.e., so that component (iii) is always different from component (ii)), and
(3) if any one or more of components (a)(i), (a)(ii), or (a)(iii) is a 2,5-dianilino-6,13-dihydroterephthalic acid or any derivative thereof, reaction step (a) additionally comprises an oxidation step (which converts the initially formed dihydroquinacridone intermediate to the corresponding quinacridone),
(iv) about 3 to about 20 parts by weight (preferably 3 to 10 parts by weight), per part of component (a)(i), of a dehydrating agent (preferably polyphosphoric acid), and
(v) 0 to about 20 parts by weight, per part of component (a)(i), of a solvent;
(b) drowning the reaction mixture from step (a) by adding said reaction mixture to about 3 to about 15 parts by weight (preferably 5 to 10 parts by weight), per part of component (a)(i), of a liquid in which the quinacridone pigment composition is substantially insoluble;
(c) isolating the quinacridone pigment composition;
(d) optionally, conditioning the quinacridone pigment composition; and
(e) optionally, blending (preferably dry blending) the resultant quinacridone pigment composition with one or more pigment derivatives (preferably quinacridone derivatives).
DETAILED DESCRIPTION OF THE INVENTION
Quinacridone pigments (by which is meant unsubstituted quinacridone, quinacridone derivatives, and solid solutions thereof) are prepared according to the invention by first ring-closing 2,5-dianilinoterephthalic acid precursors, including known aniline-substituted derivatives thereof, as well as their metal or amine salts or esters, by heating the 2,5-dianilinoterephthalic acid precursors in the presence of a dehydrating agent (preferably polyphosphoric acid) and a sulfonyl-containing derivative of 2,5-dianilinoterephthalic acid according to the invention or, less preferably, by thermally inducing ring closure in a high-boiling solvent in the presence of a sulfonyl-containing derivative of 2,5-dianilinoterephthalic acid according to the invention. The quinacridone-containing reaction mixture is then drowned and the resultant quinacridone pigment composition is isolated by known methods. Although generally not necessary, the resultant quinacridone pigment composition can also be subjected to additional conditioning steps to improve pigmentary properties and, if desired, blended with various additives.
Ring-closure step (a) is carried out in a dehydrating agent, particularly a strong acid such as polyphosphoric acid, acidic esters
Badejo Ibraheem T.
Rice Daphne J.
Bayer Corporation
Gil Joseph C.
Green Anthony J.
Henderson Richard E. L.
Roy Thomas W.
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