Abstract:
PROBLEM TO BE SOLVED: To carry out a reaction while controlling the concentration of a specific composition in a mixture and control the selectivity of the chemical reaction by a method comprising the fractionation of a solution of a mixture of compounds of chemically equilibrium state and reacting the fractionated part with other compound. SOLUTION: A solution of a mixture of two or more kinds of compound of chemically equilibrium state is made to react, separately from a reaction of a polyoxymethylene glycol, formaldehyde monomer and/or a formaldehyde solution containing methylene glycol with aniline in the presence of an acid catalyst, with at least one kind of other compound 9. The reaction is carried out by (A) fractionating the mixture into at least two parts (the necessary part 5 and the remaining part 6) containing the different compounds in the mixture existing at a high concentration relative to the chemically equilibrium state by a separation method and (B) reacting a fractionated part 5 with the compound 9 by a main reactor 2 before the complete reforming of the chemical equilibrium to obtain the objective product 10.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a thiol, a thioether, and a disulfide, by reacting an olefin with hydrogen sulfide. SOLUTION: This method for preparing a sulfur-containing compound expressed by general formula I (Q is -S- or -S-S-; and R 1 is H or a 1-30C saturated or unsaturated straight-chain or branched-chain alkyl and R 2 is H or a 1-30C saturated or unsaturated straight-chain or branched-chain alkyl, provided that R 1 and R 2 are not allowed to be H at the same time) comprises reacting a mixed gas stream containing the hydrogen sulfide with the 1-30C straight-chain or branched-chain olefin by using, or not using, oxygen, wherein reaction is conducted at a pressure of 2-325 bar in the presence of water and carbon dioxide. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To produce plural kinds of isocyanates at the same time in high yield while suppressing the formation of by-products by reacting the corresponding plural kinds of amines with phosgene in a mixing means and a downstream retention time reactor, separating the reaction mixture and fractionating the products. SOLUTION: Plural kinds of isocyanates (e.g. diphenylmethane diisocyanate and toluylene diisocyanate) are produced at the same time by reacting the corresponding plural kinds of amines (e.g. hexamethylenediamine and diphenylmethanediamine) with phosgene in a mixing means (e.g. a static or dynamic mixer) and a downstream retention time reactor, separating the reaction mixture from excess phosgene and hydrogen chloride and fractionating the reaction mixture into individual isocyanate fractions.
Abstract:
PROBLEM TO BE SOLVED: To provide a process for preparing an alkylthiol by the addition of hydrogen sulfide to a double bond of an olefin by which the problems caused by the use of a solid acid catalyst are solved. SOLUTION: The process for preparing the alkylthiol involves adding hydrogen sulfide to the double bond of the 6-20C olefin at a temperature of from 20 to 150°C and a pressure of from 1 to 40 bar, wherein the reaction is carried out in the presence of at least one liquid organic acid. The use of the liquid organic acid as a catalyst for increasing the selectivity and/or reaction rate in the addition of the hydrogen sulfide to the double bond of the 6-20C olefin to prepare the alkylthiol is also provided. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a method for inexpensively producing a metal formate/formic acid mixture on an industrial scale. SOLUTION: The method for producing the metal formate/formic acid mixture comprises (a) a process for reacting at least one kind of a metal hydroxide with carbon monoxide (CO) or a CO-containing gas in an aqueous solution in the presence of a catalyst to give the corresponding metal formate, (b) a process for separating water and the catalyst by distillation, (c) a process for adding formic acid and (d) a process for properly adjusting the metal formate/formic acid mixture obtained by the processes (a)-(c) to its storage temperature. In the process (a), the metal hydroxide is an alkali metal and/or an alkaline earth metal hydroxide and the process (c) is carried out at a proper time before the process (b). COPYRIGHT: (C)2004,JPO
Abstract:
The invention relates to a method for producing organic isocyanates, said method consisting of the following steps: (a) a first partial quantity of chlorine containing
Abstract:
The invention relates to an aqueous formaldehyde solution, containing formaldehyde in the form of monomeric formaldehyde, methylene glycol and polyoxymethylene glycols in a total concentration x >/= 65 wt. %. Said solution is characterized in that the average molar mass M of the polyoxymethylene glycols is equal or inferior to the values, which are obtained according to formula I, depending on the formaldehyde concentration, whereby M represents the average molar mass and x the total concentration of formaldehyde in the form of monomeric formaldehyde, methylene glycol and polyoxymethylene glycols in wt. % (formaldehyde total concentration).
Abstract:
The invention relates to a method for producing trioxane by the trimerization of formaldehyde in an aqueous acidic solution and by subsequently separating out trioxane from a mixture (trioxane raw product) essentially consisting of trioxane, water and formaldehyde. The invention is characterized in that: a) the trioxane raw product from the trimerization is distilled; b) the trioxane is crystallized out; c) is separated out from the mother liquor; d) is subsequently melted, and; e) additional byproducts are removed by distillation.