Mitsubishi Gas Chemical Company, Inc.

Atsushi Iwamoto

Toshio Watanabe

Teruyuki Ninomiya

Takaki Ikebe

Masafumi Watanabe

Soemu Miyashita

Akira Mori

Ikutaro Kuzuhara

In the method of producing ditrimethylolpropane of the present invention, the distillation still residue obtained in the production of trimethylolpropane is subjected to crystallizing treatment while strictly regulating the amount of organic solvent to be used, the crystallization temperature and the crystallization time within the specific ranges. With the method of the present invention, a highly pure di-TMP is obtained only by a single operation of the crystallization.

Method for producing ditrimethylolpropane

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.

Process for producing a polyol

A method of producing a highly pure trimethylolpropane from a crude trimethylolpropane obtained by a reaction of n-butyl aldehyde and formaldehyde in the presence of a basic catalyst in a two-stage process of an aldol condensation and a crossed Cannizzaro reaction. Since a high-boiling component and an inorganic salt are removed in advance from the crude trimethylolpropane, hardly removable impurities such as condensation products in the crude trimethylolpropane are changed in the subsequent heat treatment under acidic conditions to components easily removable by distillation. By distilling the heat-treated crude trimethylolpropane, a highly pure trimethylolpropane with a low content of remaining formaldehyde and a low coloring degree is easily obtained.

Method of producing highly pure trimethylolpropane

A process for producing a polyhydric alcohol with high selectivity by subjecting formaldehyde and a specific aliphatic aldehyde to an aldol condensation reaction in the presence of a base catalyst, and then subjecting the resultant reaction product to a crossed Cannizzaro reaction, while reacting a solution containing a 2-substituted-2-alkanal, formed as a byproduct during the aldol condensation reaction, with water or formaldehyde in the presence of the base catalyst, and thereafter reacting the resultant mixture with the aliphatic aldehyde.

Process for producing polyhydric alcohol

A process for producing a polyhydric alcohol which comprises subjecting formaldehyde and a specific aliphatic aldehyde to an aldol condensation reaction in the presence of a base catalyst, and then subjecting the resultant reaction product to a crossed Cannizzaro reaction, while separating 2-alkenal formed as a byproduct during the aldol condensation reaction, prior to the completion of the crossed Cannizzaro reaction. Also a process for producing a polyhydric alcohol which comprises reacting formaldehyde with a 2-alkenal, such as that obtained in the aldol condensation reaction, in the presence of a base catalyst, then subjecting the resultant reaction product and a specific aliphatic aldehyde to an aldol condensation reaction, and subsequently subjecting the resultant reaction product to a crossed Cannizzaro reaction. The processes provide a polyhydric alcohol in high selectivity with a minimum excess of formaldehyde, without substantially by-producing a 2-alkenal.

A process for producing ditrimethylolpropane which comprises reacting trimethylolpropane, 2-ethylacrolein, and formaldehyde in the presence of a basic catalyst. Ditrimethylolpropane is produced efficiently and industrially advantageously.

Process for producing ditrimethylolpropane

There is disclosed a process for producing a polyhydric alcohol which comprises reacting an aliphatic aldehyde with formaldehyde in the presence of a base compound consisting essentially of a hydrogencarbonate and a carbonate which have been formed by the oxidation or hydrolysis of a formic acid salt, in particular, the process according to the above process wherein a formic acid salt which has been by-produced by the reaction of an aliphatic aldehyde with formaldehyde is oxidized or hydrolyzed in the presence of a noble metal catalyst or a nickel catalyst in a reductive state to form a base compound consisting essentially of a hydrogencarbonate and a carbonate and this base compound is circulated through the reaction of the aldehyde and formaldehyde and is reused as the base compound. The above process enables easy and highly efficient production of high quality polyhydric alcohols substantially without by-producing a formic acid salt with a low value-added.

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Okayama, Japan

Atsushi Iwamoto