Method for producing ditrimethylolpropane

Patent metadata

Field	Value
Publication number	US-9169184-B2
Application number	US-201113820586-A
Country	US
Kind code	B2
Filing date	Sep 5, 2011
Priority date	Sep 7, 2010
Publication date	Oct 27, 2015
Grant date	Oct 27, 2015

Abstract

The present invention provides a method for producing ditrimethylolpropane which is characterized by the following (1) and (2): (1) a distillation still residue separated from purified trimethylolpropane is subjected to re-distillation under specific conditions to obtain a ditrimethylolpropane-containing solution having given contents of bis-TMP and tri-TMP; and (2) when subjecting the ditrimethylolpropane-containing solution to crystallization with an organic solvent, the crystallization is initiated under pressure at a temperature exceeding a boiling point of the organic solvent as measured under normal pressures, and the resulting crystallization product solution is cooled at a temperature drop rate of 2° C./min or less. According to the above method, it is possible to produce a high-purity ditrimethylolpropane from a distillation still residue obtained upon production of trimethylolpropane in a simple, industrially useful manner.

First claim

The invention claimed is:

1. A method for producing ditrimethylolpropane (di-TMP) by recovering the di-TMP from a reaction solution containing trimethylolpropane (TMP), the di-TMP, tritrimethylolpropane (tri-TMP) and bistrimethylolpropane (bis-TMP), which is produced by reacting n-butyl aldehyde and formaldehyde in the presence of a base catalyst, said method comprising:
(I) reacting n-butyl aldehyde and formaldehyde in the presence of the base catalyst to obtain the reaction solution (A1) containing the TMP, the di-TMP, and the bis-TMP and/or the tri-TMP as by-products;
(II) distilling the reaction solution (A1) to remove unreacted formaldehyde therefrom and obtain the TMP-containing solution (A2);
(III) subjecting the TMP-containing solution (A2) to extraction with the organic solvent (Y1) to separate a reaction product-containing extract therefrom;
(IV) distilling the extract obtained in (III) to remove the organic solvent (Y1) therefrom and obtain the crude TMP (A3);
(V) distilling the crude TMP (A3) to separate the purified TMP (A4) therefrom and obtain a di-TMP-containing solution (B1) from the distillation still residue;
(VI) further distilling the di-TMP-containing solution (B1) to separate a di-TMP-containing solution (B2) as a distillate therefrom; and
(VII) subjecting the di-TMP-containing solution (B2) to crystallization with the organic solvent (Y2) containing an aliphatic ketone to obtain di-TMP (B3);
said method being carried out under the following conditions (1) and (2):
(1) the di-TMP-containing solution (B2) obtained in (VI) contains the bis-TMP and the tri-TMP in amounts of 10 parts by mass or less and 5 parts by mass or less, respectively, on the basis of 100 parts by mass of the di-TMP; and
(2) in (VII), the crystallization is initiated under pressure at a temperature exceeding a boiling point of the organic solvent (Y2) as measured under normal pressures, and the resulting crystallization product solution is cooled at a temperature drop rate of 2° C./min or less.

2. The method for producing ditrimethylolpropane according to claim 1 , wherein (VI) is carried out using a distiller constructed from combination of a thin-film evaporator and a rectifying column, and a bottom pressure of the distiller upon further distilling the di-TMP-containing solution (B1) in (VI) is from 0.1 to 1.0 kPa.

3. The method for producing ditrimethylolpropane according to claim 1 , wherein a bottom temperature of the distiller upon further distilling the di-TMP-containing solution (B1) in (VI) is from 250 to 300° C.

4. The method for producing ditrimethylolpropane according to claim 1 , wherein the organic solvent (Y2) used in (VII) is acetone.

5. The method for producing ditrimethylolpropane according to claim 1 , wherein in (VII), a mass ratio of the organic solvent (Y2) to the di-TMP-containing solution (B2) [organic solvent (Y2)/di-TMP-containing solution (B2)] is from 0.5 to 20.

6. The method for producing ditrimethylolpropane according to claim 1 , wherein a temperature upon initiation of the crystallization in (VII) is from 70 to 90 ° C.

7. The method for producing ditrimethylolpropane according to claim 1 , wherein a pressure upon initiation of the crystallization in (VII) is from 0.11 to 0.3 MPa.

8. The method for producing ditrimethylolpropane according to claim 1 , wherein in (VII), the crystallization initiation temperature is held for a time period of from 0.1 to 5 hours.

9. The method for producing ditrimethylolpropane according to claim 1 , wherein a temperature upon termination of the crystallization in (VII) is from 40 to 20 ° C.

10. The method for producing ditrimethylolpropane according to claim 1 , wherein a pressure upon termination of the crystallization in (VII) is from 100 to 20 kPa.

11. The method for producing ditrimethylolpropane according to claim 1 , wherein the organic solvent (Y2) vaporized in (VII) is cooled and fed back to the crystallization system to remove heat generated upon the crystallization.

Assignees

• Matsumoto Masami
• Shigeta Hiroaki
• Nakagawa Nozomi
• Kuzuhara Ikutaro
• Mitsubishi Gas Chemical Co

Inventors

• Matsumoto Masami
• Shigeta Hiroaki
• Nakagawa Nozomi
• Kuzuhara Ikutaro

Classifications

• C07C41/01

  Preparation of ethers · CPC title

• C07C41/40 Primary

  by change of physical state, e.g. by crystallisation · CPC title

• C07C29/38

  by reaction with aldehydes or ketones · CPC title

• C07C41/42 Primary

  by distillation · CPC title

• C07C31/22

  Trihydroxylic alcohols, e.g. glycerol · CPC title