230 results about "Crotonic acid" patented technology

The present invention relates to a thermoplastic/natural cellulosic fiber composite, and more specifically to a high molecular weight compatibilizer within that composite resulting in both a high flex strength and high modulus and significant reduction in water absorption. The compatibilizer is preferably a terpolymer comprising: a) 0.5-20 percent by weight of monomer units selected from the group consisting of maleic anhydride, substituted maleic anhydride, mono-ester of maleic anhydride, itaconic anhydride, maleic acid, fumaric acid, crotonic acid, acrylic acid and methacrylic acid; b) 0 to 40 percent by weight of monomer units selected from styrene and functionalized styrene; and c) 40 to 98.5 percent by weight of monomer units selected from the group consisting of C_1-8 alkyl acrylates and methacrylates, and vinyl acetate.

A polishing composition includes fumed alumina, alumina other than fumed alumina, colloidal silica, a first organic acid, a second organic acid, an oxidizing agent, and water. When the second organic acid is citric acid, the first organic acid is preferably malic acid, while when the second organic acid is malic acid, the first organic acid is preferably citric acid. When the second organic acid is succinic acid, iminodiacetic acid, itaconic acid, maleic acid, malonic acid, crotonic acid, gluconic acid, glycolic acid, lactic acid, or mandelic acid, the first organic acid is preferably either citric acid or malic acid. The polishing composition can be suitably used for polishing the surface of a substrate for a magnetic disk.

The invention discloses a polycarboxylate-based ceramic water reducer and a preparation method as well as an application thereof. The water reducer comprises monomers, distilled water, an inorganic chain transfer agent and an initiator; the monomers account for 29-45 percent of the total mass of the monomer and the distilled water; the monomers comprise acrylic acid and crotonic acid; acrylic acid accounts for 66-89 percent of the total mass of the monomers, and crotonic acid accounts for 10-40 percent of the total mass of the monomers. The polycarboxylate-based water reducer based on crotonic acid has the advantages of low mixing amount, high water reducing rate, simplicity in preparation and operation and no need of compounding with inorganic salts, and meet the requirements of ceramic production enterprises; the requirements on equipment during the production of the polycarboxylate-based ceramic water reducer are simple, post treatment is unnecessary, the energy consumption is small, and no environmental pollution is generated; the dose of pottery clay is small during application, the water reducing effect is good, the fluidity of ceramic slurry can be remarkably improved, and the viscosity of ceramic slurry is reduced; no settlement phenomenon of ceramic slurry appears within the adding dose range.

This invention relates to a method for synthesizing crotonic acid by selective oxidation of crotonaldehyde. The method adopts crotonaldehyde as the raw material, acetone, acetic acid, benzene or toluene as the solvent, phosphomolybdic acid as the main catalyst, and V2O5 as the cocatalyst, and reacts at 30-100 deg.C and 0.3-0.9 MPa in the presence of O2 to obtain crotonic acid. Phosphomolybdic acid can be supported by such carriers as active carbon, SiO2, gamma-Al2O3 or molecular sieve. Therefore, the catalyst can be separated from the reaction solution by filtration, and dried in air at 120 deg.C for recycling. The supported catalyst has such advantages as simple preparation, high catalytic activity, high selectivity, and high stability, and can be used repeatedly.

This invention relates to a method for synthesizing crotonic acid from crotonaldehyde byproduct. The method comprises: distilling 20-40% crotonaldehyde byproduct by controlling the boiling point of the distillate on the top of the column at 25-65 deg.C to remove light components and obtain 45-60% crotonaldehyde in the solution in distillation kettle, adopting the solution in distillation kettle as the raw material, acetone, acetic acid, benzene or toluene as the solvent, phosphomolybdic acid as the main catalyst, and V2O5 as the cocatalyst, and reacting at 30-100 deg.C and 0.3-0.9 MPa in the presence of O2, separating the catalyst, distilling to remove the solvent, and recrystallizing with deionized water for twice to obtain crotonic acid with a purity higher than 99%. Phosphomolybdic acid can be supported by such carriers as active carbon, SiO2, gamma-Al2O3 or molecular sieve. Therefore, the catalyst can be separated from the reaction solution by filtration, and dried in air at 120 deg.C for recycling. The method has such advantages as simple process and high crotonic acid yield.

Compositions for securing pre-pasted and non-pre-pasted wall coverings to a surface that is to be decorated are provided. The present compositions are aqueous colloidal dispersions or polymeric solutions comprising from about 3% to about 30% solids. The present compositions comprise water, an alkali, from about 2.5% to about 25% by weight of an alkali-soluble, polyvinyl acetate-crotonic acid copolymer, a thickener, and a glycol.

The invention provides a method for preparing cilnidipine used as a dihydropyridine calcium antagonist, which comprises the following steps: 2-(3-nitrobenzyl) acetoacetic acid 2-methoxyethyl acetate 4 and beta-amino crotonic acid cinnamic ester 5 react in an alcohol solvent to obtain a coarse product of cilnidipine 1, and the coarse product of the cilnidipine 1 is recrystallized to obtain the cilnidipine 1. The method has the advantages of short reaction period, simple and convenient after-treatment, simple synthetic route, moderate process condition, and the like and is suitable for industrial production.

The present invention relates to a process for the preparation of a polymer P having amide and ester groups in the solid state of aggregation, in a first step (a) a homo- or copolymer P1 of (meth)acrylic acid, itaconic acid or crotonic acid being reacted with at least one monohydroxy compound E at a temperature up to 200° C. to give a polymer P2, so that anhydride groups form in addition to ester groups, in a second step (b) the polymer P2 prepared in step (a) being cooled to below 60° C. so that the polymer P2 is present in the solid state of aggregation or as supercooled melt, and in a third step (c) the polymer P2 having anhydride groups and present in the solid state of aggregation or as supercooled melt being amidated with at least one amine compound A at temperatures below 60° C., the amine compound A used in the third step (c) being present in the solid state of aggregation or on or in a solid carrier material.

The invention discloses a preparation method of a delayed coagulation type ether polycarboxylate water reducing agent. The preparation method comprises the following steps: (1) preparing an esterification monomer; (2) performing a copolymerization reaction; and (3) performing a neutralization reaction. The preparation method uses a saccharide compound and crotonic acid to prepare the esterification monomer, and has the advantages of low costs and simple and convenient operation; the prepared saccharide esterification product participates in the next step of the copolymerization reaction, so that the main chain of the polycarboxylate water reducing agent has a polyhydroxy structure, the prepared polycarboxylate water reducing agent has a better delayed coagulation effect, the initial setting and final setting time of cement is effectively prolonged, and negative effects caused by using a retarder can be reduced; and the polyhydroxy structure of the saccharide compound enables the polycarboxylate water reducing agent to have better slump loss resistance, so that the pumping construction of concrete in summer is facilitated.

The invention discloses a synthesis method of cilnidipine. The synthesis method comprises the following steps: putting methoxyethyl-2-(3-nitrobenzylidene)acetoacetate and beta-amino crotonic acid cinnamyl ester into a reaction kettle, and under the nitrogen protection, adding an isobutyl alcohol solvent and an isobutyl alcohol aluminum catalyst for reflux reaction; cooling and putting over night, and filtering to obtain a cilnidipine crude product; washing with ethanol at 5-10 DEG C, and recrystallizing by using anhydrous ethanol to obtain a cilnidipine fine product. In the synthesis method, the isobutyl alcohol is used as the solvent and the isobutyl alcohol aluminum is used as the catalyst; compared with the prior art, the synthesis method has the advantages as follows: the reaction process is simple and the reaction yield is increased.

The invention adopts a new method for optically resolving DL-2-amino-crotonic acid ester, thereby producing important intermediate S-(+)-2-amino-crotonic acid ester hydrochloride for preparing levetiracetam.

The invention relates to a manufacture method of ham sausage type silkworm feed. The method comprises the following steps that: 1) soybean flour, mulberry green branch powder, starch, vitamin C, compound vitamin B, inorganic salt, citric acid, crotonic acid, choline chloride and the like are placed into mulberry leaf powder to be stirred to the uniformly mixed state, and dry powdery feed is obtained; 2) water is added into the dry powdery feed obtained in the first step, the materials are continuously stirred until the materials are uniformly mixed, and mixed feed is obtained; and 3) the mixed feed obtained in the second step is sequentially subjected to filling, buckling and steam boiling, then, the steamed and boiled feed is placed into cold water to be soaked, then, the feed is cleanly flushed, and the ham sausage type silkworm feed is obtained. When the manufacture method provided by the invention is adopted, the feed ham sausage type silkworm feed problem is solved, and the long-distance transportation problem is also solved.