Karan The present invention condensacoon to a method of purifying a crude TMP obtained by an aldol condensation and a subsequent crossed Cannizzaro reaction of NBAL of formaldehyde in the presence of a basic catalyst. Formaldehyde used in the present invention as starting material can be used as an aqueous solution or solid as paraformaldehyde. Therefore it occurs industrially advantageously a highly pure TMP usable as a raw material for ultraviolet curable resins. Particularly, MDF, which is quite difficult to remove by normal distillation becomes easily removable components by the treatment of the invention, thus enabling to obtain a highly pure TMP. TMP obtained by the reaction between NBAL and formaldehyde in the presence of basic catalyst in the two-stage process of the aldol condensation and the subsequent crossed Cannizzaro reaction contains the impurities hardly removable by distillation.
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Shaktigul For an industrial process, the sodium or potassium salts are preferred. The product mixture from the reaction of NBAL and formaldehyde is separated, if necessary after removing formaldehyde unreacted by condensation in crude TMP and the formic acid salt, obtained as a byproduct during the crossed Cannizzaro reaction by a solvent extraction or hot filtration after condensing.
It is known that the condensation products mentioned above are thermally decomposed under acidic conditions publication of Japanese Patent No. A process for obtaining trimethylolpropane-enriched product streams from the secondary streams of trimethylolpropane.
TMP obtained by the reaction between NBAL and formaldehyde in the presence of basic catalyst in the two-stage process of the aldol condensation and the subsequent crossed Cannizzaro reaction contains the impurities hardly removable by distillation. After removing the component and high boiling inorganic salt of crude TMP, the resultant TMP distillate is subjected to a heat treatment under acidic conditions.
The purity of TMP obtained was However, the cast detrimentally final TMP color was as high as These basic catalysts may be used alone or in combination of two or more. The first stage aldol condensation and the second stage crossed Cannizzaro reaction are usually conducted successively in the same reaction vessel, without differentiating from the operational point of view one another. The present invention is further explained by reference to the following examples which should not be construed as limiting the scope of the present invention.
In the present invention, as the load of distillation column is reduced, the distillation apparatus improved from the economic viewpoint with respect to the structure and operatively allowing it to produce a highly pure TMP advantageously in industrial scale.
However, since TMP after the solvent extraction, the hot filtration, etc. The gas chromatographic analysis showed that the purity of TMP obtained was In the present invention, before the subsequent heat treatment, a component of high boiling point and an inorganic salt, including the sldolica of residual formic acid obtained as a byproduct during the crossed Cannizzaro reaction, the TMP crude thus separated was previously removed.
Therefore, an object of the present invention to provide an industrially advantageous method for producing a highly pure TMP from a crude TMP obtained by a reaction between NBAL and formaldehyde in the presence of a basic catalyst in aldllica two-phase condensation aldol and a subsequent crossed Cannizzaro reaction. In addition, a highly pure TMP is obtained, since the remaining formaldehyde condenses with TMP is to condehsacion easily removable CMF during one heat treatment under acidic conditions.
The impurities are free formaldehyde, condensation products of TMP and formaldehyde, methanol contained in formalin starting, methanol formed during the crossed Cannizzaro reaction, condensation products of methanol, TMP and formaldehyde, etc. Recientemente, el TMP cruzafa empezado a ser ampliamente utilizado y particularmente en el uso como materia prima para resinas curables con ultravioleta, presentando el TMP cindensacion pureza superior a la que antes se ha llegado a requerir.
To completely remove the impurities such as formaldehyde, MDF, etc. The present invention has been accomplished based on this finding. A process for the decomposition of polyhydric alcohols in the synthesis of high-boiling by-products formed. EST3 — Tucked to produce highly pure trimethylolpropane. Process for separating alcohols from mixtures of alcohols, water and other compounds.
A method of further purification is described in DD-A Thus, a highly pure TMP has not been obtained with conventional distillation methods. Deactivation is carried out by adding the acid to the crude TMP in an amount 0. Without adding phosphoric acid and without subjecting to heat ccondensacion, g of the distillate mainly comprising TMP by distillation at under a reduced pressure of Pa 1 Torr using a column with Sulzer-packed 10 theoretical stages purified. However, when TMP contains the formic acid salt and the component of high boiling condensation products are decomposed hard by heat treatment in the presence of acid even in an amount equivalent to the amount of formic acid salt condensacon, leaving obtained this a highly pure TMP mode.
The basic catalyst is used in an amount of 1. The solvent may be used alone or in combination of two or more. The content of the remaining formaldehyde in the final TMP was 5 ppm. Ejemplo comparativo 4 Comparative Example 4. The liquid reaction mixture from the two-stage process contains a formic acid salt formed during the crossed Cannizzaro reaction. Para un procedimiento industrial, se prefieren las sales de sodio o potasio.
The content of the remaining formaldehyde in the final TMP was 3 ppm. In the present invention, as described above, after first removing the inorganic salt such as sodium formate, and the component of high boiling the crude TMP, the treated TMP is subjected to heat treatment under acidic conditions. Ejemplo comparativo 2 Comparative Example 2. The reaction was complete after 0. The aldol condensation and the subsequent crossed Cannizzaro reaction may be carried out in the presence of water in an amount of 2 to 20 times by weight of NBAL.
The present invention relates to a method of purifying a crude TMP obtained by an aldol condensation and a subsequent crossed Cannizzaro reaction of NBAL of formaldehyde in the presence of a basic catalyst.
Then, after further adding The content of the remaining formaldehyde in the final TMP was 1 ppm. With such heat treatment, the component hardly removable from TMP by distillation is thermally decomposed or chemically combines to form an easily removable component of TMP by distillation. In the following examples and comparative examples, the content of the remaining formaldehyde in the final TMP product was determined by acetylacetone method, and the color cast APHA color pattern obtained according to JIS K document 6.
As a result of extensive studies in the production method of TMP to eliminate the above problems, the inventors have found that a highly pure TMP is obtained from a crude TMP by previously removing a component of high boiling point and an inorganic salt such as sodium formate, the crude TMP, heat-treating the treated TMP under acidic conditions, and purifying the heat-treated TMP by distillation, etc.
The method proposed in Japanese Patent Publication No. Such an acid may include mineral acids such as phosphoric acid and sulfuric acid and organic acids such as p-toluenesulfonic acid and methanesulfonic acid.
The Japanese Patent Publication No. Most Related.
Condensación aldólica cruzada