345 results about "Diphenyl carbonate" patented technology

Disclosed is a method for producing an aromatic polycarbonate, which comprises reacting acetone with a phenol material, thereby producing bisphenol A, and polymerizing the resultant bisphenol A with diphenyl carbonate to produce an aromatic polycarbonate while producing phenol as a by-product, wherein the by-product phenol is recovered as a crude phenol product containing the by-product phenol as a main component and containing impurities, and the crude phenol product is used as at least a part of the phenol material for producing bisphenol A. According to the method of the present invention, a crude phenol product as such, containing, as a main component, a by-product phenol which is by-produced during the polymerization reaction for producing an aromatic polycarbonate, and containing impurities, can be utilized for producing an aromatic polycarbonate, without any purification or the like. In the method of the present invention, not only can a necessity for complicated operations, such as a purification treatment, be reduced, but also the amount of wastes can be reduced and the yield of the aromatic polycarbonate, based on any of phenol and bisphenol A, can be improved.

Diphenyl carbonate is produced by reacting phenol with diethyl carbonate in a series of fixed bed reactors each of which is connected at different position on a distillation column via side draw and return streams. The composition of material in a distillation column varies along the length of the column, which is predictable under a given set of conditions of temperature and pressure, thus withdrawing streams at different stages in the column, allows the reactor receiving the feed from a particular stage to be operated under conditions to maximize the desired reaction, while allowing the unreacted or byproduct to go back into the distillation and be sent to a stage (by the equilibrium of the distillation) where they are favorably treated in a reactor.

A poly(carbonate-co-ester) block copolymer is synthesized using synthetic strategies that can be incorporated into conventional melt facilities that are commonly used in the production of polycarbonate polymers. The polycarbonate block of the poly(carbonate-co-ester) copolymer is derived from a polycarbonate reaction mixture comprising an aromatic dihydroxy compound and a carbonic acid diester, such as bisphenol A and diphenyl carbonate, respectively. The second block of the copolymer is derived from a polyester prepolymer, the polyester prepolymer comprising a diol, diacid or diester, and at least one monomer that is selected to advantageously incorporate desired properties into the poly(carbonate-co-ester) copolymer. The polyester prepolymer is introduced to the polycarbonate reaction mixture to form the poly(carbonate-co-ester) copolymer. Properties of the copolymer can be altered by varying numerous conditions of the reaction.

Electrochemical devices for converting carbon dioxide to useful reaction products include a solid or a liquid with a specific pH and/or water content. Chemical processes using the devices are also disclosed, including processes to produce CO, HCO⁻, H₂CO, (HCO₂), H₂CO₂, CH₃OH, CH₄, C₂H₄, CH₃CH₂OH, CH₃COO⁻, CH₃COOH, C₂H₆, (COOH)₂, (COO⁻)₂, acrylic acid, diphenyl carbonate, other carbonates, other organic acids and synthetic fuels. The electrochemical device can be a CO₂ sensor.

The invention discloses a two-metal composite oxide catalyst of synthetic biphenyl carbonate through ester exchange, which consists of vanadium oxide and copper oxide, wherein the mole ratio is that V:Cuú¢100í†1-100; The sintering temperature is between 250 and 850 deg C; the parent body can be vanadium salt or vanadium oxide and copper salt or copper oxide; the making method adapts coprecipitation method or mechanic abrasion method. The invention improves the total productivity of biphenyl carbonate, which is easy to separate and recover the biphenyl carbonate.

Polycarbonates containing low or undetectable levels of Fries rearrangement products and comprising repeat units derived from one or more of resorcinol, hydroquinone, methylhydroquinone, bisphenol A, and 4,4′-biphenol have been prepared by the melt reaction of one or more of the aforementioned dihydroxy aromatic compounds with an ester-substituted diaryl carbonate such as bis-methyl salicyl carbonate. Low, or in many instances undetectable, levels of Fries rearrangement products are found in the product polycarbonates obtained as the combined result of a highly effective catalyst system which suppresses the Fries reaction and the use of lower melt polymerization temperatures relative to temperatures required for the analogous polymerization reactions using diphenyl carbonate.

The invention discloses a method for synthesizing diphenyl carbonate by heterogeneous ester interchange. The method uses methyl carbonate and phenol as raw materials and hetero-atom mesoporous molecular sieve as a heterogeneous catalyst to synthesize the diphenyl carbonate through ester interchange. The method mainly solves the problems of difficult separation and recycling of the catalyst, low yield of the diphenyl carbonate, and the like. The hetero-atom mesoporous molecular sieve as the catalyst can be prepared through a direct synthesis method, and can also be prepared through a post synthesis method. The ester interchange product of the method has high yield and good selectivity, wherein the yield reaches 45.1 percent and the selectivity reaches 99.9 percent; and particularly the molecular sieve catalyst used by the method has the advantages of no pollution to environment, no corrosion to equipment, easy separation and recycling, and the like, and can be widely applied to production of the diphenyl carbonate.

The present invention provides a method for making polycarbonates. One embodiment of the method comprises reacting diphenylcarbonate with a dihydric phenol. The diphenylcarbonate is made by reacting a reaction mixture comprising aryl alcohol together with a dialkyl carbonate in a reactor to produce aryl alkylcarbonate and diaryl carbonate.

The invention relates to a method for interesterification synthesis of diphenyl carbonate by dimethyl carbonate. In the method, phenol and the dimethyl carbonate are used as raw materials, and carbon nano tube-loaded titanium dioxide is used as a catalyst; the carbon nano tube-loaded titanium dioxide used as the catalyst can be prepared by a sol gel method, a immersion method or a hydrothermal method; and the catalyst takes carbon nano tube (CNT) as a carrier and titanium dioxide as an active component. The catalyst has the high activity, good selectivity and high stability on reaction for preparing the diphenyl carbonate by using the dimethyl carbonate and the phenol, so that the total yield of the dimethyl carbonate and alkyphenyl carbonic ester reaches 49.0%, no byproducts are generated, the catalyst can be repeatedly used for four times, and the conversion rate of the phenol still keeps above 45%. The carbon nano tube-loaded titanium dioxide catalyst is a multi-phase catalyst, is easy to separate, can be recycled and has potential industry application value.

Liquid crystal polycarbonates are made by forming a reaction mixture containing (a) an activated diaryl carbonate; (b) at least two species of aromatic diols selected from among resorcinol, 4,4′-biphenol, hydroquinone, methylhydroquinone, 4,4′-dihydroxyphenylether, dihydroxynaphthalene, including in particular the 2,6, 1,5, and 2,7 isomers, 4,4′-dihydroxybenzophenone and 2,6-dihydroxyanthraquinone (anthraflavic acid); and (c) optionally bisphenol A in a maximum amount of 10 mole %; and processing the reaction mixture in a melt transesterification reaction to form a liquid crystal polycarbonate. While the product composition has the same overall characteristics as compositions made using diphenyl carbonate as the donor moiety for the carbonate linkage, they are analytically distinguishable because of limited incorporation of intermediate or end-cap residues derived from the activated diaryl carbonate.

The present invention relates to a supported heteropoly compound catalyst used for an ester exchange synthesis reaction and is in particular applicable for a reaction to synthesize alkyl aryl carbonate (for example, methyl phenyl carbonate) and diaryl carbonate (for example, diphenyl carbonate) through the ester exchange of dialkyl carbonates (for example, dimethyl carbonate) and aromatic phenolic compound (for example, phenol). The catalyst uses a supported heteropoly compound as an active component, and a mulit-pore material as a carrier to make the total yield ratio reach 46 percent, and the selectivity reach 99 percent. Moreover, the catalyst is provided with the advantage that the catalyst is environment-friendly, causes no corrosion to the equipment, and can be separated easily, the preparation is simple, and so on.

The invention relates to a preparation method of a catalyst used for synthesizing diphenyl carbonate by an ester exchange method. The method is characterized in that a mesoporous molecular sieve MCM-41 is taken as a carrier, butyl titanate and ammonium metavanadate are taken as active components, an immersion method is employed for loading the active components, technical steps of ultrasonic processing and calcination are combined, so that the catalyst containing two active components titanium and vanadium is prepared. The catalyst has the advantages that active components are fine, distribution is uniform, the catalyst has high phenol conversion rate and ester exchange selectivity during a process for preparing diphenyl carbonate by reacting dimethyl carbonate and phenol, a phenol conversion rate can reach more than 46.0%, and no by product is generated. According to the invention, the preparation method is simple, raw materials of the catalyst have the advantages of low cost and easy acquisition, preparation cost is low, and the prepared catalyst does not generate pollution for environment and equipment.

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.

It is an object of the present invention to provide a specific process that enables a high-purity diphenyl carbonate that can be used as a raw material of a high-quality and high-performance polycarbonate to be produced stably for a prolonged period of time on an industrial scale of not less than 1 ton/hr from a reaction mixture containing a catalyst and reaction by-products that has been obtained through transesterification reaction and the like using a dialkyl carbonate and a phenol as a starting material. Although there have been various proposals regarding processes for the production of reaction mixtures containing aromatic carbonates by means of a reactive distillation method, these have all been on a small scale and short operating time laboratory level, and there have been no disclosures on a specific process or apparatus enabling mass production on an industrial scale from such a reaction mixture to a high-purity diphenyl carbonate that can be used as a raw material of a high-quality and high-performance polycarbonate. According to the present invention, there are provided a high boiling point material separating column A and a diphenyl carbonate purifying column B each comprising a continuous multi-stage distillation column having specified structures, and there is provided a specific process that enables a high-purity diphenyl carbonate which is important as a raw material of a high-quality and high-performance polycarbonate to be produced stably for a prolonged period of time on an industrial scale of not less than 1 ton/hr from a reaction mixture containing the diphenyl carbonate using an apparatus in which these two continuous multi-stage distillation columns are connected together.

The invention relates to an organic titanium catalyst for an exchange reaction of dimethyl carbonate and phenol ester. The catalyst is composed of titanium oxyacelate formed through coordination of titanium and an acetate radical, and a solvothermal method is adopted to solve the catalyst and mainly solves the problems of difficult catalyst separation and recovery and low ester exchange activity. The organic titanium catalyst prepared through the method has a high catalysis effect on a reaction for synthesizing diphenyl carbonate through an ester exchange process, and allows the phenol conversion rate to reach 47.8% and the ester exchange selectivity to reach above 99.9%. The catalyst has the advantages of cheap and easily available raw materials, simple preparation method, insolubility in a reaction system, easy separation and recovery from the reaction system after the reaction, and repeated use.

The invention discloses a preparation method of a catalyst for synthesizing diphenyl carbonate, and belongs to the technical field of catalyst synthesis. The catalyst is obtained by modifying a transition metal oxide by poly-electrolyte until the transition metal oxide is positively or negatively charged, and wrapping a layer of metal organic framework (MOFs) on the outer surface of the transition metal oxide by an electrostatic layer-by-layer self-assembling method, namely the oxide is used as a core, and the MOFs is used as a shell; the catalyst is MalphaObeta@MOFs fort short (M is one of transition metal elements, and alpha and beta are valences). The catalyst is enabled to react with ammonia chloride with a certain concentration to convert the core MalphaObeta into corresponding chloramine salt M(NH3)nClbeta (n is the number of ammonia molecules and is equal to 1 to 8); after ammonia is removed by low-temperature roasting, the catalyst MClbeta@MOFs is obtained. The catalyst can be used in a system for generating diphenyl carbonate by transesterification between urea or carbamic acid ester and phenol; new coordination adsorption is performed on the catalyst and ammonia generated by the reaction system to push the reaction to move rightwards; the yield of a diphenyl carbonate product is up to 90 percent or above; after the catalyst is used for 5 times, the catalysis effect is still good.

The invention discloses a method used for synthesizing diphenyl carbonate through ester exchange reaction by using dimethyl carbonate (DMC) and phenylethyl acetate (PA) as raw materials. The method is characterized in that a catalyst system used by the method basically consists of beta-diketone compounds (seen in structural general formulas 1 and 2) belonged to IVB-class metals, and also can be homologous compound thereof. The catalyst system can exist stably in the air, the catalyst has good selectivity and catalytic activity on products comprising methyl phenyl carbonate (MPC) and the diphenyl carbonate (DPC), and the using amount of the catalyst is little. Therefore, the catalyst system can be widely applied to the production of the diphenyl carbonate. In the structural general formulas 1 and 2, M is Ti, Zr and Hf; and R and R' are substituted groups on the beta-diketone compounds, and can be alkyl, alkoxyl and halogen.

A method for preparing TiO2/SiO2 catalyst for exchanging and synthesizing diphenyl carbonate by dimethyl carbonate and phenol ester includes: utilizing SiO2 as a carrier and TiO2 as an active component, utilizing urea as additives and diacetone as inhibitor, and roasting after dissolving and gelling, wherein the titanium and silicon mole ratio is 1:1-60. The method mainly solves the problem about low ester exchange yield of multi-phase catalyst. The TiO2/SiO2 catalyst prepared by the method has higher catalytic activity and ester exchange selectivity for exchanging and synthesizing diphenyl carbonate by dimethyl carbonate and phenol ester, phenol transformation rate can reach 42.9%, overall selectivity of ester exchange products (methyl phenyl carbonate and diphenyl carbonate) is larger than 99.9%, and byproducts are not detected. The method for preparing TiO2/SiO2 catalyst for exchanging and synthesizing diphenyl carbonate by dimethyl carbonate and phenol ester is simple and short in preparation time, and raw materials therefore are low in cost and easy to obtain.