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362 results about "Phthalic acid anhydride" patented technology

Gas-phase oxidization process and process for the preparation of phthalic anhydride

This invention relates to the vapor-phase oxidation of hydrocarbons by passing a gaseous mixture comprising of a molecular oxygen-containing gas and hydrocarbons which may contain substituents to a fixed bed of catalyst and provides a process for vapor-phase oxidation to be effected by passing a gaseous mixture of raw materials to a fixed bed of catalyst in which the void ratio of the catalyst layers increases by stages in one step or more from upstream downward in the flow of the gaseous mixture of raw materials. For example, the process can oxidize in vapor phase such hydrocarbons as naphthalene, xylene, benzene, toluene, durene, butene, acenaphthene, anthracene, indene and their derivatives in high yields with high productivity. Moreover, the process can prepare phthalic anhydride in high yields with high productivity by the vapor-phase oxidation of naphthalene or ortho-xylene.
Owner:NIPPON MICROMETAL

Clean esterification method for producing bialkyl ortho phthalate

The present invention relates to a clean esterification method for producing dialkyl phthalate. It is characterized by that it adopts the ionic liquid formed from sulfonic acid group functionalized alkyl pyridine cation or sulfonic acid group functionalized 1,3-dialkyl iminazol cation or 2-oxopyrrolidine cation and organic or inorganic anion X as catalyst of reaction and reaction medium; at normal pressure its reaction temperature is 90-130deg.C and reaction time is 1-2hr, it can catalyze the esterification reaction of phthalic anhydride and isooctanol or n-octanol so as to obtain the invented dialkyl phthalate.
Owner:QINGDAO UNIV OF SCI & TECH

Specific fluorescent probe for identifying hydrazine and application thereof

The invention discloses a specific fluorescent probe for identifying hydrazine and an application thereof, belonging to the field of fine chemical engineering. The fluorescent probe is a 4-trifluoromethyl-7-aminocoumarin derivative, and is prepared by steps of putting 4-trifluoromethyl-7-aminocoumarin, phthalic anhydride and sodium acetate into a reaction bottle in proportion, and performing backflow by adding acetic acid. The fluorescent probe and the corresponding hydrazine content detection process cannot be interfered by biological system matrixes and impurities, so the fluorescent probe can be used for quantitative measurement of the hydrazine content in various biological systems. The probe has high specificity, and can be subjected to hydrolysis after specifically reacting with hydrazine; a hydrolysate has good fluorescence characteristics. Raw materials are cheap and easily available, can be obtained through chemical synthesis, and synthesis process is simple and feasible; the probe has high sensitivity, is suitable for detecting the hydrazine content in cells, and can be used for measuring the hydrazine content by drawing a standard curve. The probe is a ratio type probe, and effectively avoids the influences of non-uniform probe distribution, environmental factors, actuators and the like on the measurement results.
Owner:CHANGSHU RES INST OF DALIAN UNIV OF TECH CO LTD

Preparation method of polymeric-microsphere-carrier immobilized N-hydroxyphthalimide catalyst

The invention belongs to the technical field of immobilized N-hydroxyphthalimide catalysts, and specifically relates to a preparation method of polymeric-microsphere-carrier immobilized N-hydroxyphthalimide catalyst. The preparation method is characterized in that intermediate product aldehyde group modified microsphere GMA / MMA-AL, modified microsphere GMA / MMA-PA bonded with a phthalic acid group and microsphere GMA / MMA-PPA loaded with phthalic anhydride PPA are prepared, and finally a functional microsphere loaded with N-hydroxyphthalimide functional microsphere group is obtained. With the preparation method provided by the invention, the efficient organic catalyst N-hydroxyphthalimide (NHPI) is easy to separate and can be reused, a system is easy to purity, and therefore, environment-friendly catalytic oxidation is realized.
Owner:ZHONGBEI UNIV

Heat-resistant single-component moisture-curing polyurethane adhesive and preparation method and application thereof

The invention discloses a heat-resistant single-component moisture-curing polyurethane adhesive and a preparation method and application thereof. The preparation method comprises the following step: carrying out esterification reaction on castor oil, phthalic anhydride and dihydric alcohol at first to prepare a castor oil modified polyester polyol with the functionality of 2.0-2.5 and containing abenzene ring aromatic structure and a long fatty acid molecular segment. When partially substituted polyols are used for modification of polyurethane, rigid benzene rings can be introduced into a soft segment. Distribution of microcrystals in the soft segment structure is controlled, so that the flexibility of an adhesive layer is enhanced; the cohesive strength is increased, and the heat resistance is improved; meanwhile, the modified castor oil polyester polyol can effectively control the crosslinking degree of the polymer and prevent the drastic reduction of performance of an adhesive or coagulation caused by excessive crosslinking degree. The castor oil modified polyester polyol is used for modifying polyurethane, so that the adhesive property and the heat resistance of the adhesive can be obviously improved. The adhesion problem of cracking at an adhesion position of wood during high-temperature baking processes such as wood drying and bent plate making in a wood processing process is solved.
Owner:FUJIAN INST OF RES ON THE STRUCTURE OF MATTER CHINESE ACAD OF SCI +1

Process for the preparation of biologically active tetrahydrobenzthiazole derivative

Improved process for the preparation of the intermediate compound of formula II for formation of biological active tetrahydrobenzothiazole compound of formula (I) as well as the biological active tetrahydrobenzothiazole compound of formula (I) and / or its pharmaceutically acceptable salts or solvates. The process comprises reacting 4-amino cyclohexanol of formula (III) or its acid addition salts with phthalic anhydride in presence of acid catalyst and their salts, in polar aprotic solvent or its mixture with organic solvent, capable of removing water azeotropically to give 4-(phthalimido)-cyclohexanol of formula (IV); oxidizing 4-(phthalimido)-cyclohexanol of formula (IV) to give 4-(phthalimido)-cyclohexanone of formula (V); brominating 4-(phthalimido)-cyclohexanone of formula (V) with brominating agent in organic solvent in presence of Lewis acid catalyst to prepare 2-bromo-4-(phthalimido)-cyclohexanone of formula (VI); treating 2-bromo-4-(phthalimido)-cyclohexanone of formula (VI) with thiourea in organic solvent in presence of base to give 2-amino-6-phthalimido-4,5,6,7-tetrahydro benzothiazol of formula (VII); reacting compound of formula (VII) with hydrazine hydrate and base in polar solvent to give racemic 2,6-diamino-4,5,6,7-tetrahydro-1,3-benzothiazole of formula (VIII); resolving racemic 2,6-diamino-4,5,6,7-tetrahydro-1,3-benzothiazole of formula (VIII) to prepare (6S)-2,6-diamino-4,5,6,7-tetrahydro-1,3-benzothiazole of formula (II). To form the compound of Formula I and if desired its salts / solvates the above process is carried out with further steps of coupling (6S)-2,6-dimino-4,5,6,7-tetrahydro-1,3-benzothiazole of formula (II) with propionaldehyde in presence of mineral acid in polar organic solvent and reducing agent to prepare (S)-(−)-2-Amino-6-(n-propylamino)-4,5,6,7-tetrahydrobenzothiazole of formula (I);and if desired converting (S)-(−)-2-Amino-6-(propylamino)-4,5,6,7-tetrahydrobenzothiazole to its pharmaceutically acceptable salts or solvates.
Owner:ALEMBIC LTD

Poly(imide-amide) copolymer, article containing poly(imide-amide) copolymer, and electronic device including same

ActiveCN106957427AImideStructural unit
A poly(imide-amide) copolymer includes: an imide structural unit which is a reaction product of a first diamine and a dianhydride, and an amide structural unit which is a reaction product of a second diamine and a diacyl halide, wherein each of the first diamine and the second diamine includes 2,2'-bis-trifluoromethyl-4,4'-biphenyldiamine, and at least one of the first diamine and the second diamine further includes a compound represented by Chemical Formula 1, wherein the dianhydride includes 3,3',4,4-biphenyltetracarboxylic dianhydride and 4,4'-hexafluoroisopropylidene diphthalic anhydride, wherein the diacyl halide includes terephthaloyl chloride (TPCI), and wherein an amount of the compound represented by Chemical Formula 1 is less than or equal to about 10 mole percent based on the total amount of the first diamine and the second diamine: NH2-A-NH2 Chemical Formula 1, wherein in Chemical Formula 1, A is the same as described in the detailed description.
Owner:SAMSUNG ELECTRONICS CO LTD +1

Analysis method for polyether polyol hydroxyl value

The invention provides an analysis method for polyether polyol hydroxyl value, which comprises the following steps: A, weighing a polyether polyol test sample m into a conical flask, and taking another empty conical flask; B, transferring a phthalic anhydride pyridine solution into the test sample accommodated conical flask and the empty conical flask respectively, placing the two conical flasks in an oscillation oil bath pan, and connecting the two conical flasks with an air condensation pipe for reaction; C, after reaction, taking the two conical flasks out of the oil bath pan for cooling; D, flushing the two conical flasks with deionized water and acetone in sequence, and oscillating the two conical flasks to mix the solutions completely; E, adding a sodium hydroxide aqueous solution into the two conical flasks respectively, and adding a few drops of phenolphthalein indicator; F, titrating the solutions in the two conical flasks with potassium hydroxide standard solution until the solutions in the two conical flasks changes into pink; and G, calculating out the polyether polyol hydroxyl value as per a formula. The method is simple in analysis procedure, has high precision and accuracy, can efficiently shorten detection period, lower experimental cost, and bring certain economical benefits to an enterprise.
Owner:SHANGHAI FALAB TEST

New preparation method of L-alanyl-L-glutamine

The invention provides a new preparation method of L-alanyl-L-glutamine. The new preparation method comprises the following steps of: reacting phthalic anhydride with L-alanyl so as to prepare phthalic anhydride-L-alanyl, and acylating and halogenating the phthalic anhydride-L-alanyl with a halogenated reagent so as to synthesize phthalic anhydride-L-alanyl halogen; carrying out esterification reaction on L-glutamic acid and alcohol under the action of acid catalysis to obtain L-glutamic acid monoester; condensing the L-glutamic acid monoester and the phthalic anhydride-L-alanyl halogen under the action of alkali to obtain phthalic anhydride-L-alanyl-L-glutamic acid monoester which is an important intermediate for synthesizing the L-alanyl-L-glutamine; adding the phthalic anhydride-L-alanyl-L-glutamic acid monoester to ammonium hydroxide for ammonolysis and deprotection, and finally crystallizing in alcohol to obtain L-alanyl-L-glutamine. The new preparation method has the advantages that reaction raw materials are easily available, L-glutamic acid and L-alanyl are low in price, the product purity and the product yield are high, the production cost can be effectively reduced, and large-scale production is realized.
Owner:CONSCI PHARMA

Multilayer catalyst having vanadium antimonate in at least one catalyst layer for preparing carboxylic acids and/or carboxylic anhydrides and process for preparing phthalic anhydride having a low hot spot temperature

The present invention relates to a catalyst system for preparing carboxylic acids and / or carboxylic anhydrides, which system comprises a plurality of superposed catalyst layers arranged in a reaction tube, where vanadium antimonate is introduced into the active material in at least one of the catalyst layers. The present invention further relates to a process for gas-phase oxidation, in which a gaseous stream comprising at least one hydrocarbon and molecular oxygen is passed through a plurality of catalyst layers and the maximum hot spot temperature is below 425° C.
Owner:BASF AG
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