Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Reexamination Certificate
2000-07-19
2003-01-14
Green, Anthony J. (Department: 1755)
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
C106S410000, C106S411000, C430S105000, C430S108200, C430S137170, C540S139000, C540S140000, C540S141000
Reexamination Certificate
active
06506244
ABSTRACT:
The invention relates to a new polymorphic pigmentary form of phthalocyanines, the preparation therof by salt-milling a phthalocyanine crude in the presence of a water-soluble neutral organic liquid, and some uses thereof.
Phthalocyanines are well-known as pigments useful for many purposes. Their properties depend very much on the metallisation, the substitution as well as the crystal modification. Usual phthalocyanine pigments for colouring purposes are non-metallized, cobalt and very especially copper phthalocyanine and halogenated derivatives thereof. There are however also some special applications where other phthalocyanines are used in small quantities, such as platinum or palladium phthalocyanine compounds as solid recording layers in optical recording media and magnesium, aluminum, titanyl, vanadyl or zinc phthalocyanine compounds as photoreceptors or charge generators in electrophotography or as magnetic recording media.
Copper phthalocyanines have been studied intensively as pigments, because their properties appeared to be absolutely unique. In fact, it is not possible to extrapolate the chemical and physicochemical behaviour, and in particular the crystal phase stability of copper phthalo-cyanines, to other phthalocyanines. For example, a copper phthalocyanine is extremely stable, while the &agr; crystal phases of magnesium, chloroaluminium, chloroindium, vanadyl and zinc phthalocyanines, are transformed into more stable crystal modifications through the influence of mechanical forces, heat and solvents, thus increasing the absorption in the near infrared but impairing the coloristic properties (Journal of Imaging Science 29/3, 116-121, 1985).
JP-A-59/157649 discloses grinding a phthalocyanine pigment with a monomer which does not cause crystal dislocation, U.S. Pat. No. 5,055,368 salt-milling titanyl fluorophthalocyanines stepwise in the absence of solvents to a poorly crystalline form, and U.S. Pat. No. 5,238,764 contacting salt-milled titanyl fluorophthalocyanine pigments with a low polar solvent to preserve its photosensitivity. However, such procedures can only be used in few particular cases.
JP-A-01/247464, JP-A-05/257322 and JP-A-07/286107 disclose zinc phthalocyanine derivatives, those of JP-A-01/247464 having the characteristic X-ray diffraction peaks of the &egr; crystal modification of copper phthalocyanine. However, these derivatives have impaired pigmentary properties due to their increased solubility.
JP-A-11/84731 discloses salt-milling copper phthalocyanine in the presence of a substituted copper phthalocyanine dispersant. This product is used in a toner.
EP-0 780 446 discloses salt-kneading phthalocyanines in the presence of liquid carboxylic acids. However, this process is complicated as the acid has to be extracted with an alkali for its separation from the pigment. An expensive, closed equipment has moreover to be used due to the acids' unpleasant smell.
Example 57 of U.S. Pat. No. 3,763,182 discloses the preparation of bluish green zinc phthalocyanine from phthalodinitrile, zinc sulfate, ammonium sulfate and sodium peroxide in polyethylene glycol at low temperature.
U.S. Pat. No. 3,903,107 discloses a process for the preparation of phthalocyanine X polymorphs, which according to U.S. Pat. No. RE-27,117 is characterized by two strong peaks at Bragg angles (2&thgr;) of 7.5 and 9.1 (in the case of metal-free phthalocyanine).
It has been surprisingly found, that phthalocyanine pigments of excellent coloristic properties, fastness and stability against flocculation, solvents and chemicals are simply obtained from crude, not chemically modified phthalocyanines which are metal-free or derived from metals others than copper, through kneading in the presence of crystalline inorganic salts in a non-aromatic, water-soluble polar solvent.
The invention relates to a process for the preparation of a pigment through kneading of a crude phthalocyanine compound with a water-soluble crystalline inorganic salt in the presence of an organic liquid, then adding water, filtrating and washing to separate said pigment from said salt, then drying said pigment, characterized in that
said phthalocyanine compound is a compound or a mixture of compounds of formula
wherein M is two hydrogens or monovalent metals, a bivalent metal, or a bivalent oxometal, hydroxymetal or halogenometal moiety, with the proviso that the metal is not copper, and each X independently from all others is hydrogen or halogen; and
said organic liquid is water-soluble and has at least one oxy or oxo group in its molecule.
Halogen is for example bromine, chlorine or fluorine, particularly chlorine. Preferably, the number of X which are halogen is 0, 8 or 16, most preferably 0, whereby the remaining X are hydrogen. Compounds of formula (I) are preferably of symmetry C
4V
or higher, determined in formula (I) without taking account of the bonds.
Suitable metals may for example be chosen from those of groups 1 to 10 and 12 to 14 of the periodic system (corresponding to the 1997 IUPAC nomenclature). Metals of the transition groups 2 to 6 and 12 to 14 are preferred because they are more inert and do not lead to coloured compounds in the presence of compounds which are often purposely also present in the final application medium, such as for example sulfur containing compounds. Magnesium, aluminum, titanium, vanadium, zirconium and zinc are most preferred for economic and environmental reasons.
Divalent metals are, for example, Zn(II), Fe(II), Ni(II), Ru(II), Rh(II), Pd(II), Pt(II), Mn(II), Mg(II), Be(II), Ca(II), Ba(II), Cd(II), Hg(II), Sn(II), Co(II) or Pb(II). Divalent oxometals are, for example, V(IV)O, Mn(IV)O, Zr(IV)O or Ti(IV)O. Divalent halogenometals are, for example, Fe(III)Cl, In(III)Cl or Ce(III)Cl. Divalent hydroxymetals are, for example, Al(III)OH, Cr(III)OH, Bi(III)OH or Zr(IV)(OH)
2
.
The application of course also relates to the pigments obtained by above-mentioned method.
The crystalline inorganic salt should be poorly soluble in the organic liquid, generally ≦100 mg/l at 20° C., preferably ≦10 mg/l at 20° C., most preferred practically insoluble at 20° C. It should however be highly soluble in water, preferably at least 10 g/100 ml. Suitable particle sizes have a maximum of the particle size distribution by weight from 1 &mgr;m to 1 mm, preferably from 5 to 200 &mgr;m, most preferred from 10 to 50 &mgr;m.
The crystalline inorganic should also be highly soluble in water, preferably at least 10 g/100 ml. Preferred crystalline inorganic salts are aluminium sulfate, sodium sulfate, calcium chloride, potassium chloride or sodium chloride. Preferred organic liquid are alcohols, ethers, ketones, esters, amides, sulfoxides, sulfones and mixtures thereof.
The organic liquid may for example be an alcohol, ether, ketone, ester, amide, sulfoxide or sulfone, such as methanol, ethanol and isomeric propyl, butyl and pentyl alcohols, ethylene glycol, propylene glycol, butylene glycol, glycerine, diethylene glycol, polyethylene glycol and polypropylene glycol or the monomethyl, monoethyl, dimethyl or diethyl ethers thereof, diacetone alcohol, ethyl methyl ketone, ethyl butyl ketone, cyclohexanone, butyl acetate, triacetin, ethylene glycol diacetate, ethylene carbonate, dimethylformamide, dimethyl-acetamide, N-methyl pyrrolidone, dimethyl sulfoxide and sulfolane. They may of course be more than one oxy and/or oxo groups in the molecule.
It is most preferred to use neutral compounds, the pK
a
and pK
b
of which are from 5.5 to 8.5, in particular from 6 to 8, especially around 7.
The ratio of organic liquid to crystalline inorganic salt is preferably from 1 ml: 6 g to 3 ml: 7 g; the ratio of organic liquid to the total weight of crystalline inorganic salt and compound of formula (I) is preferably form 1 ml: 2,5 g to 1 ml: 7,5 g. The weight ration of compound of formula (I) to crystalline inorganic salt is preferably from 1:4 to 1:12.
Kneading is suitably effected at a temperature of from just above the melting point to just below the boiling point of the organic liquid, for a period of from ab
Grandidier Yves
Hirano Keisuke
Nagasue Hitoshi
Ciba Specialty Chemicals Corporation
Crichton David R.
Green Anthony J.
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