100 results about "Monoethyl maleate" patented technology

The invention discloses a method for preparing dimethyl succinate. The method comprises two reaction processes of esterification and hydrogenation and the reaction processes are as follows: (1) after pre-esterification reaction, maleic anhydride-methanol solution enters a catalytic distillation tower from the upper rectifying section of the tower, methanol enters the tower from the lower stripping section of the catalytic distillation tower, the reaction section is filled with solid acid catalyst, the two material flows perform countercurrent contact on the surface of the catalyst to perform esterification reaction and synthetize dimethyl maleate; and (2) dimethyl maleate and hydrogen are placed in a fixed bed reactor to perform hydrogenation reaction and generate the dimethyl succinate product in the presence of hydrogenation catalyst under a certain reaction condition. The method of the invention has the advantages of high raw material conversion rate and good product selectivity; and the process flow is simple, the energy consumption is low, no pollution can be caused and the scale production of dimethyl succinate can be realized.

The present invention belongs to the field of chemical engineering technology. It relates to a new catalyst for preparing 1,4-butanediol by utilizing hydrogenation of dimethyl maleate. Said invention uses mesopore molecular sieve MCM-41 as carrier and impregnates it with Cu salt solution to prepare catalyst precursor, then the precursor is calcined so as to obtain the invented Cu/MCM41 catalyst. Said catalyst has higher activity and higher 1,4-butanediol selectivity.

The invention relates to an improved method for preparing dimethyl maleate through reaction of maleic anhydride and methanol. The method completes preparation of the dimethyl maleate in a single catalysis and distillation tower, namely the method comprises the following steps that: mono-esterification reaction is performed in a tower kettle of the catalysis and distillation tower, and reaction heat is used for directly generating methanol steam; and simultaneously, liquid-phase reaction products containing monomethyl maleate are added to the upper part of the catalysis and distillation tower through a pipeline and flow down and generate counter current contact with the gradually dried methanol steam which flows up to complete the reaction. According to the method, not only the esterification reaction heat can be effectively utilized but also heat exchange and mono-esterification reaction equipment in the prior art can be saved, thereby the flow is more compact and more reasonable.

The invention discloses a continuous preparation method of 1,4-butanediol. The method comprises the following steps: carrying out a monoesterification reaction on bio-based succinic acid and methanolto obtain a succinic acid monoesterification liquid containing succinic acid monomethyl ester; mixing with monomethyl maleate to obtain a mixed esterification liquid; feeding into a double esterification reaction tower, and carrying out a double esterification reaction to generate a mixture of dimethyl succinate and dimethyl maleate; feeding the mixture into a hydrogenation reactor, and carrying out a hydrogenation reaction, wherein the the dimethyl maleate in the mixture is hydrogenated to generate dimethyl succinate; and performing a cascade reaction to convert into an intermediate product gamma-butyrolactone, and then generating 1,4-butanediol and tetrahydrofuran. According to the method, the bio-based succinic acid is adopted to partially replace monomethyl maleate to produce 1,4-butanediol, so that the consumption of petroleum chemicals is reduced, and the production cost of 1, 4-butanediol is reduced; and bio-based succinic acid and methanol are subjected to a monoesterificationreaction, and then mixing is performed with monomethyl maleate, so that the mutual influence caused by co-monoesterification of succinic acid and maleic anhydride is avoided.

The invention relates to a preparation method of a copper hydrogenation catalyst, which comprises the following steps: adding a mixed salt solution of soluble copper salt and other metal soluble salts into an alkali solution to prepare corresponding hydroxide precipitate, filtering, washing with water, uniformly mixing with a sodium hydroxide solid phase, adding warm water and aluminum powder paste into the mixed material, and uniformly stirring, and maintaining for a certain time at a certain temperature, then transferring into a still kettle for treatment, then replacing sodium ions in the system through hydrothermal treatment, and finally drying and roasting to obtain the copper-based catalyst. The copper-based catalyst prepared by the method has the characteristics of small stacking density, large porosity, high activity and multiple catalytic functions, and is particularly suitable for and simultaneously used as a catalyst for preparing ethylene glycol by hydrogenation of dimethyl oxalate, preparing butanediol by hydrogenation of dimethyl maleate/dimethyl succinate, preparing 1, 4-cyclohexanedimethanol by hydrogenation of 1, 4-cyclohexanedicarboxylic acid dimethyl ester, preparing 2-methyl furan by hydrogenation of furfural/furfuryl alcohol, and the like.

The invention provides a preparation method for a high-performance polycarboxylic acid water-reducing and slump-retaining agent. The method comprises the following steps of: (1) reacting polyethylene glycol and maleic anhydride in an enclosed reaction kettle at the temperature of 80-130 DEG C for 2-6 hours to obtain a maleic anhydride polyethylene glycol ester; (2) uniformly mixing diluted water, vitamin C serving as a reducting agent, maleic anhydride, 2-acrylamide-2-methyl propane sulfonic acid and the maleic anhydride polyethylene glycol ester obtained in the step (1), pumping into a high-level groove 1, uniformly stirring dimethyl maleate or a mixture of the dimethyl maleate and monomethyl maleate, and pumping into a high-level groove 2 for later use; and (3) adding a polyether monomer, hydrogen peroxide and water into a polymerizing kettle, heating, controlling the temperature between 50 DEG C and 70 DEG C, uniformly dropwise adding materials in the high-level groove 1 and the high-level groove 2 into the polymerizing kettle simultaneously, preserving heat for 0.5-2 hours after adding, neutralizing the pH value to 5-7 with liquid alkali, adding water till needed concentration is reached, and discharging to obtain the high-performance polycarboxylic acid water-reducing and slump-retaining agent. The polycarboxylic acid water-reducing and slump-retaining agent prepared with the method has excellent slump-retaining performance, and is environmentally-friendly.

The embodiment of the invention provides sensitively responsive polymer nano-particles which comprise poly(cystamine bisacrylamide-alt-spermine) and polyethylene glycol-b-polylysine(2,3-dimethyl maleate); in poly(cystamine bisacrylamide-alt-spermine), a cystamine bisacrylamide monomer and a spermine monomer are connected through a carbon-nitrogen bond; in polyethylene glycol-b-polylysine(2,3-dimethyl maleate), a polyethylene glycol chain segment is methyl-polyethylene glycol-amino; one end of a polylysine chain segment is connected with the amino end of the polyethylene glycol chain segment through an amide bond; and 2,3-dimethyl maleate is connected with amino on the side chain of the polylysine chain segment through an amide bond. The sensitively responsive polymer nano-particles are good in stability and can be effectively enriched at a tumor site; loaded medicinal molecules can enter tumor cells easily; in addition, the sensitively responsive polymer nano-particles are good in biocompatibility and easy to degrade.

The invention discloses a preparation method of a dimethyl maleate hydrogenation catalyst, which comprises the following steps: 1, preparing a copper and zinc coprecipitation material; 2, preparing pseudo-boehmite colloidal sol; 3, preparing a catalyst precursor from the coprecipitation material and the pseudo-boehmite colloidal sol or from the coprecipitation material, the pseudo-boehmite colloidal sol and pseudo-boehmite powder; and 4, drying, roasting, and tabletting to obtain the catalyst. The invention also discloses another preparation method which comprises the following steps: preparing a catalyst precursor by mixing a coprecipitation material and pseudo-boehmite colloidal sol, drying, roasting, then mixing with pseudo-boehmite powder, and tabletting or granulating to obtain the catalyst. Besides, the invention also discloses a method for realizing catalytic dimethyl maleate hydrogenation by using the catalyst. The proportion of the product can be adjusted according to market demands. According to the invention, the prepared catalyst is good in strength and low in roasting temperature, has favorable catalytic property and can effectively reduce occurrence of polymerization reaction in the reaction process at the same time.

The invention provides a production method of dimethyl maleate, and in particular relates to a method used for producing the dimethyl maleate by enabling mixed liquid, which is obtained by using dimethyl maleate as a solvent to absorb maleic anhydride in maleic anhydride-containing mixed gas and is taken as a raw material, and methanol to be subjected to an esterification reaction. The production method comprises the following steps: enabling the maleic anhydride-containing mixed gas to be subjected to heat exchange and preliminary cooling, and then enabling the maleic anhydride-containing mixed gas to enter the bottom of an absorption tower and be in counter-current contact with the dimethyl maleate sprayed from the top of the tower so as to obtain absorption liquid; filling an esterification tower with solid acid esterification catalyst filler, pumping the absorption liquid from the top of the esterification tower, and enabling the pumped absorption liquid and the methanol at the bottom of the esterification tower to be subjected to a contact type reaction; obtaining a dimethyl maleate crude product at the bottom of the tower, distilling to obtain the dimethyl maleate product, and returning part of the dimethyl maleate product for absorbing the maleic anhydride in a spraying way; carrying out distillation and separation on water-containing methanol steam on the top of the tower to obtain methanol and water, and returning the methanol for the esterification reaction.

The invention discloses a technique for hydrogenation production of dimethyl succinate by using an intermediate product of 1,4-butanediol device. Particularly, the invention invents a new production process of dimethyl succinate. The technique disclosed by the invention comprises the following steps: generating a mixture of dimethyl succinate and methanol by hydrogenation production of an intermediate product generated after esterification reaction in a maleic anhydride method BDO device, wherein the intermediate product is a mixture of dimethyl maleate, dimethyl fumarate, dimethyl methoxy butyl diacid and methanol; carrying out distillation separation on the mixture, thus preparing a polymer-grade dimethyl succinate product of which the purity reaches 99.95% or above. According to the technique, an esterification part device of the maleic anhydride method BDO and a hydrogen compressor are directly utilized, the productive investment of dimethyl succinate is reduced and good economic benefits can be obtained.

The invention belongs to the technical field of chemical products, and particularly relates to a dimethyl maleate hydrogenation reaction catalyst as well as a preparation method and an application thereof. The catalyst comprises the following elements in percentage by mole: 30 to 40 percent of Cu, 20 to 30 percent of Mn, 10 to 20 percent of Al, 10 to 20 percent of Zn, 0 to 5 percent of Ag and 0 to 5 percent of Ru. The Al element, the Ag element and the Ru element are added into the catalyst, so that dispersion and modification of active components in the catalyst are realized, the total selectivity of BDO and gamma-butyrolactone can reach 93%, the cost can be effectively reduced, and the catalyst is green and environment-friendly. According to the present invention, with the catalyst, the 1, 4-butanediol and/or gamma-butyrolactone can be prepared with high selectivity by changing the reaction conditions during the 1, 4-butanediol preparation process through the dimethyl maleate hydrogenation reaction catalyst; the preparation method of the catalyst is simple and low in cost, and the prepared catalyst is environmentally friendly and has long service life.

The invention belongs to the technical field of powder coatings and in particular relates to a luster-enhancing agent for a powder coating as well as a preparation method and application of the luster-enhancing agent. The luster-enhancing agent for the powder coating, provided by the invention, is prepared from the following raw materials: dimethyl maleate, tert-butyl acrylate and (perfluoro cyclohexyl)methyl acrylate; an end capping agent, an initiating agent and an organic solvent are added and a copolymerization reaction is carried out to obtain the luster-enhancing agent. The luster-enhancing agent for the powder coating, provided by the invention, has better compatibility with the powder coating, and can be used for wetting base materials very well and improving the adhesive force; the coating prepared from the luster-enhancing agent has better anti-impact performance and can be cured into a film very well, and the leveling property of the powder coating is better; the luster-enhancing agent provided by the invention has obvious luster enhancing performance, and can be used for preparing the high-gloss powder coating; a fluoro raw material has the effect of improving the water-resistance property of the luster-enhancing agent, and the water boiling capability is remarkably improved.

The invention discloses a valve pressure resistant sealing ring material, and relates to the technical field of sealing ring manufacturing. The valve pressure resistant sealing ring material is prepared from the following raw materials in parts by weight: basic oil, dimethyl maleate, alkyl polyglucoside, kukui nut oil, sodium formate, carboxymethyl chitosan, poly-polyvinyl pyridine, nano ferroferric oxide microspheres, polyvinyl acetate, silicon dioxide powder, a beeswax matrix, plant extract oil, butyl rubber, modified butyl acrylate, a modified organic silicon phenolic aldehyde epoxy resin, high-pressure low-density PE (Polyethylene), graphene, a polyamide fiber and polytetrafluoroethylene. The valve pressure resistant sealing ring material disclosed by the invention is good in high pressure resistance, high temperature resistance, low temperature resistance and corrosion resistance, not liable to break, long lasting in use and applicable to preparation of sealing rings, and due to adoption of the high-pressure resistance PE and the graphite, the toughness and the tensile strength of the material are improved.