Method for preparing 2-hydroxy-6-ureidocarbonyl naphthalene derivative
申请人:KABUSHIKI KAISHA UENO SEIYAKU OYO KENKYUJO
公开号:EP1564206A1
公开(公告)日:2005-08-17
Disclosed is a method for preparing a 2-hydroxy-6-ureidocarbonyl naphthalene derivative. The method comprises the step of reacting 2-hydroxy-6-aminocarbonyl naphthalene and a isocyanate in an organic solvent at a temperature of 90-200°C. According to the present invention, 2-hydroxy-6-ureidocarbonyl naphthalene derivative can easily be obtained within relatively short time and high yield.
The present invention provides a monoazo compound represented by formula (1) or a salt thereof:
wherein, Y1 and Y2 represent a group selected from hydrogen atom, formula (2) and formula (3);
-CO-E-X (3)
provided that at least one of Y1 and Y2 is a group represented by formula (2);
Z is a group selected from formulae (4), (5) and (6);
Crystal structures of two black monoazo (hydrazone) pigments have been determined from powder X-ray diffraction data combined with DFT calculations. The DFT calculations suggested the molecules are in hydrazone forms but not in azo forms in both crystal structures. The molecular arrangements in the crystal structures suggested Davydov splitting may occur by excitonic interactions and it causes the red absorption band shift in the crystalline state leading to the characteristic black colors.
The present invention provides a safe charge control agent which exhibits an excellent negative chargeability and excellent dispersibility in and compatibility with binder resins, and is even applicable for col or toners. Specifically, the charge control agent consists of a naphthol derivative of formula [I]:
and a salt thereof, and an electrophotographic toner comprising the agent are provided.
Process for dehydrating hydrous sodium Beta-naphtholate
申请人:KABUSHIKI KAISHA UENO SEIYAKU OYO KENKYUJO
公开号:EP1506950A1
公开(公告)日:2005-02-16
The present invention provides a process for dehydrating hydrous sodium β-naphtholate comprising: the step of heating the hydrous sodium β-naphtholate or a mixture of the hydrous sodium β-naphtholate and β-naphthol which comprises no more than 0.2 mole of β-naphthol per one mole of sodium β-naphtholate in a solvent at a temperature of 260-300°C under an inert gas. The process makes it possible to dehydrate hydrous sodium β-naphtholate thoroughly in a short time with less production of tarry components.