Mitsubishi Gas Chemical Company, Inc.

Masafumi Watanabe

Ikutaro Kuzuhara

Junichi Amemiya

Toshio Watanabe

Atsushi Iwamoto

Soemu Miyashita

Teruyuki Ninomiya

Takeru Nishida

Naoshi Mori

Junichi Ameniya

In the production of spiroglycol by the reaction of pentaerythritol and hydroxypivalaldehyde in water in the presence of an acid catalyst, (A) a total content of amines and amine salts in hydroxypivalaldehyde is reduced to 1.5% by weight or lower; (B) seed crystals are added to the reaction system before initiating the reaction and/or during the reaction in an amount from 1.5 to 30% by weight on the basis of the total feed amount of pentaerythritol, hydroxypivalaldehyde, water, the acid catalyst and the seed crystals, each being fed into the reaction system; (C) the pH of the reaction system is kept from 0.1 to 4.0 from initiation of the reaction to completion of the reaction; and (D) the sum of a maximum theoretical amount of spiroglycol to be synthesized from pentaerythritol and hydroxypivalaldehyde to be fed into the reaction system and an amount of spiroglycol contained in the seed crystals to be added to the reaction system is controlled within a range from 5 to 35% by weight on the basis of the total feed amount. The spiroglycol produced has an increased particle size. By washing the spiroglycol with a basic solution, the heat stability is improved.

Process for producing spiroglycol

Provided is a method for producing di-TMP by reacting n-butyl aldehyde (NBD), formaldehyde and a base, said method including a first step of reacting the NBD, formaldehyde (1) and a base (I) to obtain a reaction mixture solution containing trimethylolpropane (TMP), di-TMP and 2-ethyl-2-propenal (ECR); a second step of distilling the reaction mixture solution to recover the ECR therefrom; and a third step of sequentially adding the ECR recovered by distillation, and adding at least one of a base (II) and formaldehyde (2), to the reaction mixture solution from which the ECR has been recovered by distillation, and thereby allowing a reaction for production of the di-TMP to proceed gradually, in which TMP is added in any one of the first to third steps or in plural steps of the first to third steps.

Process for production of ditrimethylolpropane

The present invention provides a method for producing ditrimethylolpropane including reacting n-butyraldehyde with formaldehyde in the presence of a base catalyst to thereby produce trimethylolpropane and ditrimethylolpropane, wherein the method includes (I) a step of reacting n-butyraldehyde with formaldehyde (1) in the presence of a base catalyst (1), to thereby produce a reaction mixture containing trimethylolpropane, ditrimethylolpropane, and 2-ethyl-2-propenal; (II) a step of recovering 2-ethyl-2-propenal through distillation of the produced reaction mixture; and (III) a step of adding, to a distillation residue obtained through recovery of 2-ethyl-2-propenal, the recovered 2-ethyl-2-propenal and formaldehyde (2), and optionally a base catalyst (2), to thereby allow reaction for production of ditrimethylolpropane to proceed, wherein the amounts of formaldehyde (I) and the base catalyst (1) supplied in step I and formaldehyde (2) and the base catalyst (2) supplied in step II are controlled to specific amounts, to thereby effectively produce ditrimethylolpropane. According to the present invention, the yield of di-TMP is considerably increased, and the amount of bis-TMP by-produced can be considerably reduced with respect to the amount of di-TMP (i.e., a product of interest) produced; that is, di-TMP can be effectively produced in an industrially advantageous manner.

A method for producing flake-like dried DOG by making DOG containing from 10 to 50% by mass of a liquid go through a continuous melt-drying step of a specified condition and then making it go through, as a next step, a vacuum-drying step of a specified condition or a ventilation-drying step of a specified condition while holding a molten state thereof, to obtain DOG in which the liquid in DOG is reduced to not more than 0.5% by mass (dried DOG), and flaking the obtained dried DOG in a flake production step.

Process for production of flake-like dried 2-(5-ethyl-5-hydroxymethyl-1,3-dioxan-2-yl)-2-methylpropan-1-ol

A process of producing 2-(5-ethyl-5-hydroxymethyl-1,3-dioxane-2-yl)-2-methylpropane-1-ol (DOG) by the acetalization of hydroxypivalaldehyde with trimethylolpropane in water in the presence of an acid catalyst and optional seed crystals. DOG crystals having an increased particle size and containing the trans isomer in a high content are produced by the process in which the reaction temperature, pH of the reaction system and concentration of DOG to be produced in the reaction system are controlled.

Process of producing dioxane glycol

The present invention provides a method of producing high-purity hydroxypivalaldehyde and/or dimer thereof, including: reacting isobutyl aldehyde with formaldehyde in a presence of a basic catalyst; distilling a low boiling point component including unreacted isobutyl aldehyde to obtain an aqueous solution; adding a diluent to the aqueous solution; cooling the aqueous solution to crystallize the hydroxypivalaldehyde and/or the dimer thereof; and subjecting the aqueous solution to a solid-liquid separation, followed by washing with an organic solvent and/or water, in which the diluent and a basic compound are added to the aqueous solution containing the hydroxypivalaldehyde and/or the dimer thereof obtained by distilling the low boiling point component off so that a concentration of the hydroxypivalaldehyde and/or the dimer becomes 5 to 23% by mass, the concentration of formaldehyde becomes 0.2 to 2.5% by mass, and a pH value becomes 5.0 or more, the solution is crystallized at a temperature of 20 to 45&#xb0; C. and subjected to the solid-liquid separation. In this method, handling of a high-viscosity slurry and carrying out any complicated operation such as regeneration of an ion exchange resin are not required, so the high-purity HPA and/or the dimer thereof can be obtained in high yield with an energetically advantageous manner.

Method of producing high-purity hydroxypivalaldehyde and/or dimer thereof

In the method of the present invention, a dimethylolcarboxylic acid is produced by reacting a trimethylolalkane and formaldehyde to prepare a cyclic formal having a formal protecting group, followed by the oxidation of the cyclic formal by using nitric acid as an oxidizing agent to prepare a cyclic carboxylic acid which is then subjected to cleavage to remove the formal protecting group. The formal protecting group protects two of the methylol groups against the oxidation to enable the production of the dimethylolcarboxylic acid with a high selectivity.

Production of dimethylolcarboxylic acid

A process for producing a polyol by reacting an aliphatic aldehyde with formaldehyde in the presence of a basic catalyst, which comprises a step of concentration which comprises removing water and unreacted formaldehyde from a reaction liquid by distillation; a step of extraction which comprises extracting the polyol from a concentrated reaction liquid with an extracting reagent; a step of washing with water which comprises washing an extract liquid with water and separating the liquid into an oil layer containing the polyol and an aqueous layer; wherein by useing an specific aliphatic aldehyde as the extracting agent and recovering the extracting reagent from the oil layer containing the polyol after adjusting pH of the oil layer, a high purity polyhydric alcohol can be obtained at a high yield with suppressed formation of byproducts such as acetal compounds and aldol compounds.

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Okayama, Japan

Masafumi Watanabe