Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Reexamination Certificate
2001-07-03
2003-04-08
Green, Anthony J. (Department: 1755)
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
C106S411000, C106S412000, C106S413000, C106S493000, C106S494000, C106S495000, C106S496000, C106S497000, C106S498000, C430S007000
Reexamination Certificate
active
06544325
ABSTRACT:
The invention relates to pigmentary solid solutions comprising copper phthalocyanine (Pigment Blue 15; C.I. 74160) as host and other blue to violet pigments as guests. Preferred hosts are the &agr; (Pigment Blue 15:1), &bgr; (Pigment Blue 15:3) and &egr; (Pigment Blue 15:6) crystal forms of copper phthalocyanine, especially the &egr; crystal form. Monophase solid solutions are preferred.
The invention also relates, furthermore, to dispersions comprising these solid solutions as pigment particles and pigment derivatives as rheology improvers. Preferred dispersions of solid solutions in the &egr; crystal lattice may be used in particular to prepare colour filters for liquid-crystal displays (LCDs) which in comparison to existing colour filters have an improved transmission window at 445±10 nm.
The correct position and the absolute value of the transmission window are the most important parameters for colour filters. There is a desire for high transmission in the wavelength range surrounding the light emission, coupled with as high as possible an absorption for different-coloured light. Normally, trichromatism is achieved by using one blue, one red and one green filter. These filters must be highly transparent, homogeneous and able to be prepared in a very uniform layer thickness.
Many blue filters are known and in some cases are available commercially. Some of them contain &egr; copper phthalocyanine (C.I. Pigment Blue 15:6) and carbazole violet (C.I. Pigment Violet 23). It has been found, however, that these filters are unable entirely to satisfy the present-day requirements. The aim of the invention is therefore to improve the blue filter.
It has repeatedly been disclosed that copper phthalocyanine (crude or in the &agr; phase) is easily convertible into its &bgr; crystal form, for example in U.S. Pat. No. 2,556,728 by salt grinding with a solvent, in EP-0 803 545 by dry grinding followed by solvent treatment, in EP-0 808 878 by dry grinding with a solid binder in an inert atmosphere, and in WO-99/54410 by dry or aqueous grinding followed by conditioning.
On the other hand, GB-1,411,880 and JP-A-04/252 273 describe the conversion of &agr; copper phthalocyanine first of all into a mixture of &agr; and &egr; copper phthalocyanine in a ball mill and then into pure &egr; copper phthalocyanine by treatment with solvents at only moderately elevated temperature. These results are, however, hardly reproductible.
U.S. Pat. No. 4,135,944 explains that the formation of &bgr; or &egr; copper phthalocyanine is dependent not only on shear force, solvent and temperature but also on the presence of a suitable phthalocyanine derivative which determines the formation of the &egr; crystal phase.
Also apparently showing themselves to be determinants of the crystal phase, according to JP-A-48/76 925, are chlorinated copper phthalocyanines, which are processed together with pure &agr; copper phthalocyanine to give a mixture whose x-ray diffraction pattern is very similar to that of &egr; copper phthalocyanine.
JP-A-09/95 638 and JP-A-08/44 056 describe the use in blue colour filters of physical mixtures of &agr; and &egr; copper phthalocyanine and, respectively, of &agr; copper phthalocyanine and dioxazine violet.
JP-A-61/266 471 discloses that the salt kneading of a copper phthalocyanine leads to the R or &bgr; form depending on whether it takes place in the presence or absence of a colourless reaction product of an aromatic isocyanate with an aliphatic amine.
JP-A-07/198 925 describes a 10% liquid dispersion of &egr; copper phthalocyanine, SiO
2
particles (“amorphous fumed silica”) and dioxazine violet in N-methylpyrrolidone. However, no solid solution is formed: in contrast, the x-ray powder diagram of a dispersion in accordance with example 1 clearly contains the characteristic signals of &egr; copper phthalocyanine and those of dioxazine violet separately alongside one another.
The invention also differs in a number of important points from the applications WO-01/04215, WO-01/09252 and JP-A-2000/281924, still unpublished at the priority date. Surprisingly, unwanted phase transformations of copper phthalocyanine in the course of salt grinding may be prevented by adding pigments from a selection of classes. Even more surprisingly, solid solutions are obtained which exhibit improved coloristic properties.
REFERENCES:
patent: 2556728 (1951-06-01), Graham
patent: 4077972 (1978-03-01), Baurecht et al.
patent: 4135944 (1979-01-01), Wheeler
patent: 4350534 (1982-09-01), Fechner et al.
patent: 4548968 (1985-10-01), Jaffe
patent: 5248336 (1993-09-01), Gerson et al.
patent: 5281268 (1994-01-01), Ganci et al.
patent: 5472496 (1995-12-01), Hendi et al.
patent: 5618343 (1997-04-01), Hendi et al.
patent: 5821373 (1998-10-01), Hao et al.
patent: 6280890 (2001-08-01), Sawamura et al.
patent: 6368399 (2002-04-01), Aoba et al.
patent: 1181248 (1964-11-01), None
patent: 101 163 (1984-02-01), None
patent: 719 842 (1996-07-01), None
patent: 0803545 (1997-10-01), None
patent: 0808878 (1997-11-01), None
patent: 1411880 (1975-10-01), None
patent: 48-076925 (1973-10-01), None
patent: 49-059136 (1974-06-01), None
patent: 51-054622 (1976-05-01), None
patent: 52-008030 (1977-01-01), None
patent: 61-266471 (1986-11-01), None
patent: 7-198925 (1995-08-01), None
patent: 2000-281924 (2000-10-01), None
patent: 99/54410 (1999-10-01), None
SciFinder Abstr. for JP 08044056 (Feb. 1996).
Derwent Abst. 1997:388615 for JP 09095638 (Apr. 1997).
Derwent Abstr. 92-252273 for JP 04252273 (Sep. 1992).
De Keyzer Gerardus
Grandidier Yves
Hall-Goulle Veronique
Ciba Specialty Chemicals Corporation
Crichton David R.
Green Anthony J.
LandOfFree
Pigmentary copper phthalocyanine solid solution and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pigmentary copper phthalocyanine solid solution and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pigmentary copper phthalocyanine solid solution and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3105959