Organic compounds -- part of the class 532-570 series – Organic compounds – Azo
Patent
1997-12-11
1999-08-24
Powers, Fiona T.
Organic compounds -- part of the class 532-570 series
Organic compounds
Azo
534850, 8639, 8922, C09B 6748, C09B 6722, D06P 118
Patent
active
059426039
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a compound having a novel type of crystal, a thermally stable crystal modification of disperse dye, a process for producing thereof, and a process of dyeing with it.
PRIOR ART
A compound represented by the following formula (1) known as a useful compound for dyestuff (Japanese Patent Publication No. 12035/1970). ##STR2## It is known that the dyestuff composition comprising the compound represented by the above formula (1) is capable of dyeing synthetic fiber such as polyester fiber in dark blue. As the results of recent streamlining and energy saving in the dyeing industry, it has become common practice to reduce a liquor ratio and to employ a process that the dispersed dye liquor is forced to circulate through a stationary substrate, such as Obermaier dyeing, cheese dyeing, beam dyeing, and other liquor flow dyeing. These dyeing processes need development of a dyestuff having an excellent dispersion stability at a high temperature for prevention of unequal dyeing by such filter effect.
As shown in FIG. 3, only amorphous type's compound, as the compound represented by the formula (1), having dull peaks of the diffraction pattern in the X-ray diffractometry of Cu-K.alpha. line is known. In the present application, ".alpha.-crystal" means a well known amorphous type of the compound represented by the formula (1) and ".beta.-crystal" means a novel crystal modification of the compound of the present invention hereinafter in order to simplify descriptions.
In the case that .alpha.-crystal is used as a dyestuff, the dyestuff is manufactured by mechanical grinding by a sand-mill together with a dispersing agent such as sodium salt of naphthalenesulfonic acid-formalin condensate or sodium lignin sulfonate as usual process for producing a dispersed dyestuff composition, and then the dyestuff composition is provided in order to dye fabrics of polyester fiber or blended woven fabrics of polyester fiber and polyacrylate fiber or cotton. However, particles of the dyestuff composition form a tar-like substance or coagulation which is formed by destroying of dispersion state because .alpha.-crystal does not have a thermal stability at a temperature of 95-135.degree. C. at which dyeing is performed on polyester fiber. The forming of such a tar-like substance and coagulated particles of a dyestuff hinder even dyeing. Particularly, in Obermaier dyeing, cheese dyeing, beam dyeing and liquor flow dyeing, since it is difficult that the coagulated particles pass through yarn or fiber layers, the particles cause clogging, failure of internal penetration, casng spot and so on and also cause not only hindering even dyeing but also deteriorating fastness of dyed substrates.
Therefore, when .alpha.-crystal of the compound represented by the formula (1), which is prepared in the well-known and usual way, is used as a dyestuff for dyeing, dispersion state of dyestuff particle in a dye bath becomes poor and such poverty in dispersion state prevents us from obtaining substrates dyed evenly.
DISCLOSURE OF THE INVENTION
As the result of that the present inventors studied earnestly in order to overcome the above-described problems, we have found that .beta.-crystal has a stability at high temperature, which is a novel crystal modification of the present invention characterized by a specific X-ray diffraction pattern of the compound represented by the above formula (1), and we have completed the present invention.
The novel .beta.-crystal of the present invention is also characterized that a tar-like substance or coagulation are not formed at high temperature more than 95.degree. C. at which dyeing is performed on synthetic fiber because of said thermal stability. And the novel .beta.-crystal of this invention is characterized by having plural, sharp peaks in the powder X-ray diffractometry shown in FIGS. 1 and 2. This differs from .alpha.-crystal having dull peaks in the powder X-ray diffractometry shown in FIG. 3. Particularly, the .beta.-crystal is characterized by
REFERENCES:
patent: 4960435 (1990-10-01), Tunoda et al.
patent: 4985043 (1991-01-01), Buhler et al.
patent: 5532344 (1996-07-01), Himeno et al.
Akatani Yoshiki
Murakami Yasuo
Nippon Kayaku Co. Ltd.
Powers Fiona T.
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