875results about "Isocyanic acid derivatives preparation" patented technology

Absorbable polyurethanes, polyamides and polyester urethanes prepared from at least one compound selected from:or the diamines and diisocyanates thereof, wherein each X represents a member independently selected from —CH2COO— (glycolic acid moiety), —CH(CH3)COO— (lactic acid moiety), —CH2CH2OCH2COO— (dioxanone), —CH2CH2CH2CH2CH2COO— (caprolactone moiety), —(CH2)yCOO— where y is one of the numbers 2, 3, 4 or 6-24 inclusive, and —(CH2CH2O)z′CH2COO— where z′ is an integer between 2 and 24, inclusive; each Y represents a member independently selected from —COCH2O— (glycolic ester moiety), —COCH(CH3)O— (lactic ester moiety), —COCH2OCH2CH2O— (dioxanone ester), —COCH2CH2CH2CH2CH2O— (caprolactone ester), —CO(CH2)mO— where m is an integer between 2, 3, 4 or 6-24 inclusive, —COCH2O(CH2CH2O)n— where n is an integer between 2 and 24, inclusive; R′ is hydrogen, benzyl or an alkyl group, the alkyl group being either straight-chained or branched; p is an integer between 1 and 4, inclusive; and Rn represents one or more members selected from H, alkoxy, benzyloxy, aldehyde, halogen, carboxylic acid and —NO2, which is attached directly to an aromatic ring or attached through an aliphatic chain. Absorbable polymers prepared from these compounds are useful for drug delivery, tissue engineering, tissue adhesives, adhesion prevention and other implantable medical devices.

One aspect of the present invention relates to ligands for transition metals. A second aspect of the present invention relates to the use of catalysts comprising these ligands in transition metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The subject methods provide improvements in many features of the transition metal-catalyzed reactions, including the range of suitable substrates, reaction conditions, and efficiency.

Carboxylic acid-substituted polyalkylene polyamines in which amine nitrogen atoms on the polyamine backbone structure are replaced by guanidine groups provide a pH range extending into high pH values. These substances are useful as carrier ampholytes in isoelectric focusing.

The synthesis process of phenyl dimethylene diisocyanate belongs to the field of isocyanate synthesizing technology. In inert liquid medium, phenyl dimethylamine or its hydrochloride or carbonate reacts with bis(trichloromethyl) carbonate at the temperature of -20 deg.c to -60 deg.c, before heating and reflux reaction for 0.5-5 hr to synthesize phenyl dimethylene diisocyanate. The amount of bis(trichloromethyl) carbonate is 0.5-15 times that of phenyl dimethylamine or its hydrochloride or carbonate. The present invention has stable solid crystal materials, and is environment friendly and suitable for industrial production.

A cyanate ester compound represented by the formula (1), wherein Ar2 represents a phenylene group, a naphthylene group or a biphenylene group, Ar1 represents a naphthylene group or a biphenylene group when Ar2 is a phenylene group, or Ar1 represents a phenylene group, a naphthylene group or a biphenylene group when Ar2 is a naphthylene group or a biphenylene group, Rx represents all substituents of Ar1, each Rx is the same or different and represents hydrogen, an alkyl group or an aryl group, Ry represents all substituents of Ar2, each Ry is the same or different and represents hydrogen, an alkyl group or an aryl group, and n is an integer of 1 to 50.

A polyol composition having a number average molecular weight of from about 1,000 to about 3,000 Daltons is made up of (1) at least 60% by weight of a low monol polyoxypropylene polyol having a number average molecular weight of from about 2,000 to 12,000 Da and a degree of unsaturation less than or equal to 0.02 meq / g and (2) no more than 40% by weight of a polyol having a number average molecular weight of from about 400 to about 1,000 Da and a polydispersity index greater than 1.1. This polyol composition is reacted with a diisocyanate, a polyisocyanate, an isocyanate-terminated prepolymer or an isocyanate-terminated quasi-prepolymer to produce polyurethane elastomers having good physical and mechanical properties. Any of the known processes for producing polyurethane elastomers, including one-shot processes, may be used to produce elastomers in accordance with the present invention.

The present invention relates in a first consideration to aldimines of formula (I). Said aldimines are particularly suitable as latent hardeners in curable compositions, particularly compositions comprising one or two-component isocyanate groups. Due to the presence of the reactive group, they can be converted to compounds of the formulas (X) and (XII) comprising aldimine groups, implementing a further consideration of the present invention. The aldimines, or the compounds comprising aldimine groups, can be used primarily in adhesive and sealant materials, but also in coatings, and can be produced easily from readily available source materials, and have good thermal stability. The tertiary amino group thereof has a surprisingly low alkalinity and can in some cases have a catalytic effect in chemical reaction systems.

The complex of the present invention containing an onium salt and a central Lewis acidic metal has a high catalytic activity at a high temperature for the copolymerization of an epoxide and carbon dioxide to produce a high molecular weight poly-carbonate.

The invention relates to high-functional polyisocyanates containing allophanate and silane groups, a method for their production and their use as a starting component in the production of polyurethane plastics, in particular as a crosslinker component in polyurethane paints and coatings.

A polyurethane prepolymer obtainable by reacting at least one aromatic polyisocyanate having symmetrical substitution of NCO groups and at least one aromatic polyisocyanate having asymmetric substitution of NCO groups, the fraction of aromatic polyisocyanate having symmetrical substitution of NCO groups being higher than the fraction of polyisocyanate having asymmetric substitution of NCO groups, and at least one polyol having an OH functionality of more than 2.5 and at least one polyol having an OH functionality of less than 2.5.

Use of homogeneous catalytic systems which include as a pre-catalyst a complex of a Group IV metal and a salalen ligand in the polymerization of alpha-olefins, is disclosed. The alpha-olefin polymers obtained are characterized by controlled levels of tacticity. Also disclosed are novel salalen ligands and novel complexes thereof with Group IV metals.

The invention relates to a mixer reactor of the rotor-stator type. This mixer reactor comprises a substantially rotationally symmetric housing which has a distributing chamber, a mixing chamber, a front plate that modifies the cross-section of the housing between these two chambers, and there are separate inlets into the mixing chamber for at least two substances and an outlet for removing the mixed material or product. The inlet for the first substance is provided in the axis of rotation of the mixing chamber. Two or more channels are aligned radially outward from this inlet, and the first substance is transported through these channels and into the mixing chamber. The inlet for the at least second substance is constructed in the form of a plurality of openings in the front plate, these inlet openings being are arranged rotationally symmetrically to the axis of rotation. Each of these inlet openings for the at least second substance has a corresponding pin which can be displaced in the axial direction.

The invention relates to a process for the preparation of isocyanates in the gas phase, in which the possibilities for back-mixing and byproduct formation are reduced by improving the mixing of the starting materials in a tubular reactor.

The present invention relates to a process of producing a collagen gel comprising collagen fibers cross-linked with each other by a cross-linking agent on the way of fibrosis of collagen, and a collagen gel comprising the cross-linked collagen fibers obtained by the process. The collagen gel comprising cross-linked collagen fibers of the present invention has high strength and thermal stability and can be widely used as cell carriers and medical materials.

The present invention provides a method for producing isocyanate, which is preferably used in the field of optical materials and is widely used as a raw material for polyurethane-based materials and polyisocyanurate-based materials, including a process capable of improving the productivity of hydrochloride . The manufacturing method of chain aliphatic isocyanate or cycloaliphatic isocyanate of the present invention comprises making chain aliphatic amine or cycloaliphatic amine and hydrogen chloride reaction, obtains chain aliphatic amine hydrochloride or cycloaliphatic amine A method for producing a chain aliphatic or cyclic aliphatic isocyanate according to a hydrochloride step, wherein the step is carried out at a pressure higher than atmospheric pressure by 0.01 MPa or more.

The invention provides a preparation method of methylene diphenyl diisocyanate. The method comprises the following steps: performing a salt forming reaction on m-xylylenediamine and hydrogen chloride gas to obtain m-xylylenediamine hydrochloride; mixing the m-xylylenediamine hydrochloride, an organic phosphorus compound and solid phosgene for reaction to obtain methylene diphenyl diisocyanate. In a process of preparing methylene diphenyl diisocyanate, according to the application, an organic phosphorus compound additive is introduced, so that the reaction of m-xylylenediamine hydrochloride is promoted, therefore, the reaction rate and the effective conversion rate are improved.

The invention relates to a process for the continuous preparation of organic isocyanates through the reaction of organic amines with phosgene in the presence of organic solvents under pressure whereby a concentrated phosgene-containing stream is mixed preferentially with an amine-containing stream in a jet mixer to create a combined jet of reacting amine-phosgene mixture, whereby the combined jet is discharged directly into a reactor vessel and the reactor vessel is operated at a temperature above the decomposition temperature of intermediate carbamoyl chloride products which can be formed upon mixing the aforementioned streams, wherein the combined jet is not pre-mixed with bulk reactor contents, wherein the jet mixer provides sufficiently rapid and thorough mixing and thereby enables an initial reaction temperature lower than the bulk reactor vessel temperature, and the combined jet entering the reactor has sufficient momentum to cause entrainment into it of a sufficient quantity of the bulk reactor contents to be rapidly dispersed and reach the bulk reactor temperature.