Abstract:
Compounds of the formulae I, II and III ##STR1## in which R is --F, --Cl, --Br, C.sub.1 -C.sub.18 alkoxy, and n is the number 0, 1, 2 or 3, are suitable in particular for use as photoconductive substances.
Abstract:
There is provided a system for decomposing and removing a toxic substance by introducing a gas containing the toxic substance into a reaction apparatus and causing the gas to contact with a heated oxide semiconductor, in which a porous material carrying, as the oxide semiconductor, chromium oxide or nickel oxide is placed in the reaction apparatus, chromium oxide or nickel oxide is thermally excited, and the gas is contacted with the chromium oxide or nickel oxide which is thermally excited. Thus, it is possible to provide a practically useful technique for decomposing and removing a toxic substance with high decomposition/removal efficiency.
Abstract:
A process for the preparation of compounds of formula I ##STR1## by reacting a pyrrolopyrrole of formula ##STR2## wherein X.sub.1 is a group selected from ##STR3## X.sub.2 is a group selected from ##STR4## or has the same meaning as X.sub.1, with a secondary amine of formula ##STR5## in the molar ratio 1:2, in the presence of an anhydrous dipolar aprotic solvent and of an amount 0.1 to 15 times in excess of stoichiometric proportion, based on the amine of formula III, of an anhydrous organic base, in the temperature range from 50.degree. to 230.degree. C. and under a pressure from 0 to 10 bar.The substituents R.sub.1 to R.sub.8, Y and Hal are as defined in claim 1.The compounds of formula I are especially suitable for use as photoconductive substances.
Abstract:
A process for the preparation of mixed crystals of 1,4-diketopyrrolo�3,4-c!pyrroles, consisting of 1 mol each of two different compounds of formula ##STR1## by heating a corresponding mixture in solid form to the temperature range from 220.degree. to 380.degree. C. A and B are, for example, each a group of formula ##STR2## wherein R.sub.1 and R.sub.2 are each independently hydrogen, chloro, bromo, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.6 alkylamino, phenyl or --CN, G is --O--, --NR.sub.7 --, --N.dbd.N-- or --SO.sub.2 --, R.sub.3 and R.sub.4 are hydrogen, and R.sub.7 is hydrogen, methyl or ethyl.The mixed crystals and solid solutions obtained are excellently suited for pigmenting high molecular weight material.
Abstract:
A coated material comprising a substrate which is coated with a layer of a pyrrolopyrrole of formula I ##STR1## wherein R.sub.1 and R.sub.2 may be 4-pyridyl and X.sub.1 and X.sub.2 are O, said compound of formula I being at least partially in the form of a salt of a strong acid, is suitable for use as an optical recording material and, owing to its electrical conductivity and photoconductivity, as antistatically treated material, as sensor, photoreceptor and solar battery.
Abstract:
Black perylene pigments which comprise one of the isomers of the formula Ia or Ib in which R1, R2 are each independently phenylene, naphthylene or pyridylene, each of which may be mono- or polysubstituted by C1-C12-alkyl, C1-C6-alkoxy, hydroxyl, nitro, and/or halogen; X is halogen; n Is from 0 to 4, or comprises a mixture of both isomers and has a blackness value ≧210 in an alkyd/melamine baking varnish.
Abstract:
The present invention provides a low-cost hydrogen gas sensor, which exhibits high sensory selectivity for protons and operates at room temperature, and can also provide a highly sensitive sensor capable of fulfilling the important functions of detecting hydrogen gas and preventing leakage accidents in production plants that use hydrogen gas as a carrier, in hydrogen gas storage facilities, and in so-called fuel cells that use hydrogen gas as an energy source. In addition, the sensor is also effective as an acid sensor for hydrofluoric acid and the like. The present invention relates to an acid and hydrogen gas sensor, wherein protons are brought into contact with an organic compound containing an introduced pyridine ring (such as pyridine-DPP), and the change in electrical resistivity, photoconductivity, or optical absorption band for the organic compound that accompanies proton addition is detected.
Abstract:
A black perylene-based pigment produced by calcining at least one compound selected from the group consisting of diimide derivatives of perylene tetracarboxylic acid and diimide derivatives of perylene diiminodicarboxylic acid, at a temperature of 200 to 600° C. in vacuum or in an inert gas atmosphere, exhibits an excellent blackness, an excellent heat resistance and an excellent weather fastness as well as a high resistance and a high safety.
Abstract:
The invention relates to an optical storage medium comprising a substrate and a storage layer, wherein the storage layer comprises a compound of the formula (I) or (II) in which A and A′, independently of one another, are unsubstituted or mono- or di-halo-, -hydroxy-, —C1-C6alkyl-, —C1-C6alkoxy-, -cyano- or -nitro-substituted phenyl, pyridyl, pyrrolyl, imidazolyl, furyl or thienyl, which can, if desired, be fused to a benzene ring, are halide, tetrafluoroborate or unsubstituted or with one or more halogen substituted C1-C6alkane-sulfonate, benzenesulfonate, C1-C6alkylbenzenesulfonate, C1-C6alkylsulfate or di-C1-C6alkyl-phosphonate of N—C1-C6alkyl-pyridiniumyl, or are unsubstituted or mono- or di-hydroxy-substituted C2-C6alkyl or C2-C6alkenyl, whose chain may be uninterrupted or interrupted by one or two oxygen atoms, B and B′, independently of one another, are 2 H, S, S2 or SO2, and n and n′, independently of one another, are each a number from 1 to 4. The invention also relates to a process for the optical writing, storage, reading, modification or erasing of data at a wavelength of from 400 to 700 nm using a novel recording medium, to an optical recorder for the optical writing, modification or erasing of data using only continuous laser radiation or only modulated laser radiation, to a process for converting a compound of the formula (I) or (II) from a black form into a red form by mechanical force, and to new compounds of the formula (I) or (II).
Abstract:
A process for the optical recording and storage of information in the form of bits by irradiating a recording material comprising a substrate coated with at least one layer of a pigment selected from the group of the dithiopyrrolopyrroles, dithioquinacridones, phthalocyanines or mixtures of several of these pigments as recording layer dotwise or linearly with laser light in the near infrared range (NIR range), which pigment (a) has a crystal modification having an absorption band in the NIR range, and (b) is in contact with a solid organic compound that changes the crystal modification of the pigment upon irradiation with laser light, so that (c) after irradiation the absorption in the NIR range is reduced, while the organic compound exhibits no absorption in the NIR range before and after irradiation.