442results about "Carbonic/haloformic acid esters preparation" patented technology

This invention describes the use of resveratrol and curcumin, representatives of naturally occurring polyphenols, in their native form, after hydrogenation, and as their respective allyl derivatives, individually, in combination with themselves and other commercial monomers, to make representative varieties of polymers, e.g., polycarbonates (PC), polyurethanes (PU), co-polymers and biodegradable polymers.

The method for synthesizing dimethyl carbonate by using urea and methanol and adopting heterogeneous catalyst includes the following steps: under the condition of 600-1300 deg.c 10X10 to the power 5-1X10 to the power 5 pa and air or oxygen gas atmosphere calcining carbonate or hydroxide of alkali metal and alkaline earth metal for 1-10 hr. to obtain catalyst, adding urea and methanol into high-pressure reaction still, and adding catalyst, heating to 120-180 deg.c under the condition of magnetic stirring, low-temp. resistion time is 2 hr-10 hr. more heating to 180-240 deg.C, high-temp. reaction time 2 hr-20 hr, cooling to room temp. and making separation so as to obtain the invented roduct.

The invention provides a supported palladium-based catalyst and a preparation method and an application thereof. The supported palladium-based catalyst comprises an active ingredient and a carrier, wherein the active ingredient is a palladium-based compound; the carrier is selected from at least one of aluminum oxide, silicon oxide, magnesium oxide, zinc oxide, zirconium oxide, titanium dioxide, metal organic framework compound, activated carbon, molecular sieve, carbon nanotube, and graphene. The supported palladium-based catalyst is applied to the reaction of methyl nitrite vapor-phase carbonylation preparing dimethyl carbonate, and has the advantages that the catalytic activity is high, the product selectivity is high, and the service life is long.

The invention discloses a process for synthesizing methyl carbonate by alcoholysis of urea with aliphatic diol as cyclic agent consisting two steps, (1) reacting urea with aliphatic diatomic alcohol (ethylene glycol or 1,2-methyl ethylene glycol) to synthesize ethylene carbonate ester or propylene carbonate ester, (2) subjecting ethylene carbonate ester or propylene carbonate ester with methanol ester to synthesize methylcarbonate.

The invention discloses a process for synthesizing methyl carbonate from alcoholysis of methanol and urea in a high pressure reactor, wherein the catalyst is a amine salt type ionic liquid having a molecular formula of R1R2R3NHX-MaXb, the raw material methanol and urea are subject to alcoholysis reaction and methyl carbonate is synthesized in one step.

The invention discloses starlike tetraphenylethylene derivative molecular glass, a positive photoresist, a positive photoresist coating and application thereof. The starlike tetraphenylethylene derivative molecular glass has the molecular structure shown in the description. The molecular glass is simple in synthesis process and suitable for industrial production; the tetraphenylethylene has a spatial solid geometrical skeleton adopting a rigid structure, can effectively inhibit molecular crystallization and is easy for film formation; the molecular glass has good solubility in various polar solvents, and has the characteristics of high glass transition temperature and high thermal stability, and can better meet requirements of a photoetching process; by adopting a spin coating method, a good film can be obtained, and the molecular glass can be used as the photoresist and can be prepared into the positive photoresist for photoetching through cooperation with other additives.

The invention discloses star-shaped adamantane derivative molecular glasses having the following structure shown in the description, wherein substituents R1-R12 are respectively hydrogen, hydroxy, alkoxy or acid sensitivity substituents; the substituents R1-R12 can be different or the same, but the substituents at a same benzene ring cannot both be hydrogen. The invention also discloses a preparation method of the star-shaped adamantane derivative molecular glasses. The method is simple in synthesis process, products of the steps of a reaction all can be separated from the system through a recrystallization or precipitation method. The molecular glasses can be used as photoresist main body materials made into thin films, and also can be used for photoetching.

The urea alcoholizing process for synthesizing dimethyl carbonate includes adding solid alkali into reactor, adding urea solution comprising urea and methanol in the molar ratio of 0.01-100 and the material feeding rate radio of 0.01-100 into the reactor, and reaction at 150-250 deg.c and 0.1-10 MPa in the conditions of reactor bottom temperature 70-200 deg.c, stripping section temperature 70-200deg.c, rectifying section temperature 70-200 deg.c and reflux ratio of 1-20. The present invention has the advantages of continuous process, mild reaction condition, etc.

The invention relates to a process for producing dimethyl carbonate from industrial synthetic gas. According to the invention, O2, CO, N2, NO, and methanol are delivered into an esterification system for esterification; heavy component drawn from the esterification system is subjected to recovery treatment in a wastewater tower; light component drawn from the esterification system passes a compressor II and is subjected to a carbonylation reaction in a carbonylation reactor; the carbonylation reaction product is delivered into a second condensation separation tower, and is subjected to gas-liquid separation; separated liquid phase is refined in a pressurized rectification tower; part of non condensable gas is discharged from the separated gas phase, and the gas phase is continued to be subjected to a reaction in the esterification system; the discharged non-condensable gas is delivered into a denitration reactor; light component at a top of the pressurized rectification tower is subjected to further recovery treatment in a methanol recovery tower; heavy component from the pressurized rectification tower is delivered into a product tower; dimethyl carbonate is drawn from the top of the product tower, and dimethyl oxalate is drawn from the bottom of the product tower. The process has the economical and practical characteristics of low equipment investment, environment friendliness, energy saving, high catalyst efficiency, high raw material utilization rate, and the like.

An integrated coal-to-liquids process is provided to minimize carbon dioxide emissions and efficiently make use of carbon resources, by recovering carbon dioxide emissions from Coal-to-Liquids (CTL) facilities, using the recovered carbon dioxide in at least one carbonylation reaction step for converting ammonia to urea and then converting urea into dimethyl carbonate.

A complex catalyst for preparing carbonate from alcohol by homogeneous oxidizing-carbonylating reaction has a chemical formula MXnLm, where M is metal, X is chosen from halogen, SO4 (or HSO4) radical, CO3 (or HCO3) radical, etc, L is chosen from RN4 ion, RP4 ion, pyridine, etc, and m=1-12. It is prepared through complex reaction between quaternary ammonium (or phosphorus) salt and metal salt. Its application method is also disclosed.

The invention belongs to the synthesis of organic carbonates and relates to a technology of synthesizing diethyl carbonate by a urea alcoholysis method. The technology comprises the steps of: adding anhydrous ethyl alcohol, ethyl carbamate and a catalyst into a high pressure reaction kettle, wherein the mole ratio of the anhydrous ethyl alcohol to the ethyl carbamate is 2 to 25, and the catalyst is combined metal oxide, and accounts for 0.5 to 10 percent of the whole system by mass percent; raising the temperature to 150 to 200 DEG C by stirring so as to carry out reaction for 1 to 15 hours; and taking out the reaction liquid after the reaction, and realizing the separation of the catalyst and the reaction liquid by simple filtration. The combined metal oxide is prepared by 2 to 3 metal oxide precursors among Li, Na, K, Ca, Mg, Ba, Sr, Al, Sn, Pb, La, Ti, W, Zr, Fe, Co, Ni, Cu and Zn through thermal decomposition method or coprecipitation method. The preparation method of the technology is simple, the catalyst activity is high, the stability is good, and the separation and recycling are easy.

A chlorine-free bimetallic catalyst for gas phase synthesis of dimethyl carbonate is characterized in that the catalyst comprises an active component of copper, an additive, and active carbon; on a metal basis, the catalyst comprises 10.0-25.0 wt% of Cu, 1.0-10.0 wt% of the additive, and 65-85 wt% of active carbon. The catalyst of the invention has the advantages of high conversion rate and good selectivity.

The present invention provides a process for the preparation of dialkyl carbonates of general formula (1)

wherein R=alkyl (C₁-C₈) or C₆H₅CH₂ the said process comprises a reaction in between cyclic carbonate and alcohol, in the presence of a solid, double metal cyanide complex catalyst, at a temperature in the range of 140-180° C., for a period of 4-10 hrs, followed by the separation of catalyst from the above said reaction mixture by known methods to obtain the desired product.

A method for enhancing the efficiency of a rhenium-promoted epoxidation catalyst is provided. Advantageously, the method may be carried out in situ, i.e., within the epoxidation process, and in fact, may be carried out during production of the desired epoxide. As such, a method for the epoxidation of alkylenes incorporating the efficiency-enhancing method is also provided, as is a method for using the alkylene oxides so produced for the production of 1,2-diols, 1,2-carbonates, 1,2-diol ethers, or alkanolamines.

A catalyst for synthesizing the propylene carbonate is composed of potassium salt (10-20 wt%), and activated carbon, metal oxide, or molecular sieve (80-90 wt%). The propylene carbonate is prepared through reaction between potassium salt, epoxy propane and iodomethane at 120-180 deg.C and 2-6 MPa for 0.5-2 hr. Its advantages are high catalytic activity, low cost and cyclic use.

A process for producing an aromatic polycarbonate through an ester interchange reaction between an aromatic carbonic acid diester and an aromatic dihydroxy compound, wherein the aromatic carbonic acid diester is obtained through the decarbonylation reaction of an aromatic oxalic acid diester represented by the following general formula (1):wherein two Ar's are the same or different aromatic hydrocarbon groups having 6 to 14 carbon atoms, and has a hydrolyzable halogen content of 5 ppm or less.According to the present invention, an aromatic polycarbonate having a high molecular weight and excellent color can be easily produced without impairing ester interchange reactivity for the production of the aromatic polycarbonate by using an aromatic carbonic acid diester obtained through the decarbonylation of an aromatic oxalic acid diester and controlling the amount of hydrolyzable halogen contained in the aromatic carbonic acid diester to a value smaller than a predetermined value.

The present invention relates to double-component carried catalyst PdCl2-Cu(OAc)2/zeolite for synthesizing diphenyl carbonate and its preparation. The catalyst consists of zeolite in 50-100 weight portions, PdCl2 in 0.1-10 weight portions and Cu(OAc)2 in 0.1-30 weight protions. It is prepared through equi-volume soaking and roasting at 250-750 deg.c. The catalyst system has also metal acetate as inorganic oxidation-reduction assistant, hydroquinone as organic oxidation-reduction assistant, and tetrabutyl ammonium bride as surfactant. The catalyst has very high catalytic activity and excellent selectivity to liquid phenol in synthesizing diphenyl carbonate. The catalyst is easy to separate from product, easy to recover and regenerate and has simple preparation process.

The invention belongs to the technical fields of organic chemistry and catalytic chemistry, and relates to an organic acid-base catalyst which is used for carboxylic acid aryl-ester groups which are compounded by ester exchanges. The organic base in the organic acid-base catalyst refers to an organic compound which contains nitrogen, phosphorus and halogen elements and solid-carrying organic base of the organic base, while the organic acid mainly refers to organic sulfonic acid, organic phosphorus acid, organic carboxyl acid, urea and the like and solid-carrying organic acid of the organic acid. The invention can be used as organic matters such as amino acid and the like which has double functions of organic acid and base and as catalysts which can be used to solid support the organic acid base on a same carrier. The catalyst of the invention has good catalytic performance and is easy to be separated from reaction systems, ester exchange conditions are temperate, the invention is convenient to continue, the conversion rate of oxalic dim-ethyl ester can reach over 90%, the selectivity to phenyloxalate can reach over 70%, and the invention is suitable for industry applications.

The invention discloses a copper-based catalyst prepared by an ammonia distillation method and an application of the copper-based catalyst in a reaction system for oxidation carbonylation synthesis of alkyl carbonate. The use of a chlorine-containing compound is completely avoided in the preparation process of the catalyst, so that the problems of equipment corrosion and deactivation caused by chlorine loss are completely solved; and the catalyst prepared by the ammonia distillation method is high in selectivity, long in service life, low in preparation cost and relatively simple in process.

The invention provides a catalyst for preparing dimethyl carbonate by using urea alcoholysis and a preparation method thereof. The catalyst has a specific surface area of 150-350 m/g, a specific pore volume of 0.5-2.0 cm/L and the pore-size distribution of 50-150, gamma-Al2O3 as a carrier accounts for 50-80 percentage of the catalyst by weight, and the balance comprises active constituents. The main active constituent comprises at least one of ZnO, CaO and PbO, and an active constituent oxide and an alumina carrier can form a stable spinelle structure. The catalyst has good stability, can achieve the stable operation service life longer than 500 hours, reacts with a urea methanol solution to synthesize the dimethyl carbonate with higher catalytic activity, has the simple preparation method, can finish load without special equipment, is beneficial to industrialized amplification, is a fixedly-carrier catalyst and solves the problem that the prior homogeneous catalyst is difficult to recycle.