JP2009143867A - Method for producing ditrimethylolpropane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems such that the separation of ditrimethylolpropane (di-TMP) from bistrimethylolpropane is difficult in a method for producing the di-TMP by recovering a byproduct in the production of the trimethylolpropane (TMP) and also the amount of production of the di-TMP is limited by the amount of production of the TMP, a method for synthesizing the di-TMP by the dehydrating condensation of 2 molecules of the TMP produces a condensate comprising ≥3 molecules as byproducts, also, a method for synthesizing the di-TMP by using an esterification-treated TMP as a raw material requires a regeneration process of the di-TMP by hydrolysis, a method for synthesizing the di-TMP from an excessive TMP with ECR requires the recovering process of the TMP, etc. <P>SOLUTION: This method for producing the di-TMP comprises a first stage of reacting n-butyraldehyde with formaldehyde (1) and a base (I) to obtain a reaction mixture containing the TMP and di-TMP, and a second stage of adding 2-ethyl-2-propenal and formaldehyde (2) and/or a base (II) to the above reaction liquid for promoting the reaction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for efficiently producing ditrimethylolpropane (hereinafter referred to as di-TMP).

  Under a base, trimethylolpropane (hereinafter referred to as TMP) is obtained by aldol condensation between normal butyraldehyde (hereinafter referred to as NBD) and formaldehyde (base acts as a condensation catalyst) and cross Canitz allo reaction (base is consumed as a reactant). When di-TMP is produced industrially, di-TMP having a higher boiling point is produced as a by-product, and di-TMP is obtained by recovering from the high-boiling mixture (residue in the still). reference). That is, a TMP extract (crude TMP) substantially free of sodium formate can be obtained by extracting the reaction product solution of NBD and formaldehyde using a solvent after or without concentration. When this crude TMP is purified by distillation under high vacuum, 1 to 20% of TMP and 20 to 50% of di-TMP are contained in the residue of the distillation kettle. As a method for recovering di-TMP from the residue in the kettle, a method of crystallization with ethyl acetate (see Patent Document 2), a method of crystallization with an aqueous solvent in the presence of sodium formate (see Patent Document 3), 1 , 4-dioxane solvent (see Patent Document 4), a method of strictly defining the conditions and crystallizing with an acetone solvent (see Patent Document 5), and the like have been proposed. In addition, as a method for increasing the amount of di-TMP by-products in producing TMP, a method of setting reaction conditions to a specific condition (see Patent Documents 6 and 7) has been proposed. A method of adding an organic solvent immiscible with water to the reaction system (see Patent Document 8) has also been proposed.

On the other hand, as a method for obtaining di-TMP itself by synthesis, a method for obtaining di-TMP by producing an ether bond by dehydration condensation of two molecules of TMP, or a method in which the method is partially improved (see Patent Document 9). It has been known. Furthermore, a method of synthesizing di-TMP by reacting 2-ethyl-2-propenal (hereinafter referred to as ECR) and TMP is also known (see Patent Document 10).
US Pat. No. 3,097,245 JP 47-30611 A JP-A 49-13311 JP 2002-47231 A Japanese Patent Laid-Open No. 2005-23067 Japanese Patent Laid-Open No. 57-139028 JP 57-142929 A JP-A-8-157401 JP-T 6-501470 JP-A-9-268150

The above-described method for obtaining di-TMP as a by-product in the production of TMP has the following problems.
The production method generally used at present is a method for recovering TMP, which is the main object, from the residue in the distillation still. In this method, a TMP reaction mixture such as formaldehyde or NBD which is a raw material for TMP, a modified product generated during TMP distillation recovery, or a by-product other than di-TMP such as acetal of TMP and formaldehyde is used. It is difficult to recover di-TMP in an industrially satisfactory yield since only the content of di-TMP is required to be separated and recovered.
In particular, it is difficult to separate di-TMP from bistrimethylolpropane (hereinafter referred to as bis-TMP), which is a linear formal of two molecules of TMP and formaldehyde contained in the residue of the TMP-manufactured distillation pot. In order to efficiently produce di-TMP, it is essential to significantly reduce the amount of by-product of bis-TMP.
At the time of TMP production, attempts have been made to increase the amount of di-TMP by-product by setting the reaction conditions to a specific condition, but the amount of di-TMP produced is still based on NBD. The yield is about 10 mol%, which is only 2 to 3 times the amount of by-product compared with the amount of conventional di-TMP by-product. In the method of extraction by adding an organic solvent immiscible with water to the reaction system described in Patent Document 8, the target compound is contained in both the aqueous layer and the organic layer after extraction, so post-treatment after the reaction is extremely difficult. Not only is it complicated, but it is necessary to recover the used organic solvent, which is extremely disadvantageous industrially. Therefore, since di-TMP is a by-product of TMP production, the production amount is inevitably limited by the production amount of TMP, and there is a problem that it cannot cope with the increase in demand for di-TMP.

On the other hand, the method of synthesizing di-TMP by producing an ether bond by dehydration condensation of two molecules of TMP can solve the above-described problem of increase in the supply and demand of di-TMP.
However, in the case of TMP having a structure having three alcoholic hydroxyl groups that can participate in the reaction in one molecule, since it is a reaction between TMP molecules, the by-product of three or more molecules of the ether condensate that is inevitably generated can be avoided. Absent. In order to suppress this, the reaction rate of the dehydration condensation reaction of TMP must be set low, and accordingly, the recovery of unreacted TMP becomes a large economic burden and is industrially disadvantageous.

In order to improve this point, Patent Document 9 describes a method using TMP obtained by reacting a part of three alcoholic hydroxyl groups in advance as an ester of a lower fatty acid as a raw material. However, even in this method, it is not possible to selectively react only two alcoholic hydroxyl groups in one molecule of TMP as an ester of a lower fatty acid. It is hard to say that it has been resolved. In this method, the step of regenerating di-TMP by hydrolysis from di-TMP having esterified alcoholic hydroxyl groups produced from TMP esterified with one or two alcoholic hydroxyl groups. Newly required, the economic burden increases and it is industrially disadvantageous.
Further, Patent Document 10 describes a method for obtaining di-TMP from excess TMP and ECR. In this method, even when TMP is used in a large excess with respect to ECR, the yield of di-TMP based on ECR is obtained. The rate is less than 70%, and moreover, the TMP used excessively needs to be recovered, which is economically disadvantageous. An object of the present invention is to provide a method for producing di-TMP efficiently and industrially advantageously.

As a result of intensive studies on a method for producing di-TMP having the above-mentioned problems, the present inventors have found that di-TMP can be efficiently produced, and have completed the present invention. That is, this invention relates to the manufacturing method of di-TMP of the following (A)-(H) description.
(A)
First step of reacting NBD with formaldehyde (1) and base (I) to obtain a reaction mixture containing TMP and di-TMP, and the reaction of ECR with formaldehyde (2) and / or base (II) A method for producing di-TMP comprising the second stage of adding to a mixed solution and allowing the reaction to proceed.
(B)
The production method according to (A), wherein the amount of ECR is 0.1 to 10.0 mol with respect to 1.0 mol of NBD.
(C)
The manufacturing method of di-TMP as described in (A) or (B) whose amount of formaldehyde (1) is 2.5-10.0 mol with respect to 1.0 mol of NBD.
(D)
The method for producing di-TMP according to any one of (A) to (C), wherein the amount of formaldehyde (2) is 2.0 to 10.0 mol with respect to 1.0 mol of ECR.
(E)
The total amount of formaldehyde (1) and (2) is 2.0-10.0 mol with respect to the sum total 1.0 mol of NBD and ECR, It is any one of (A)-(D) Of manufacturing di-TMP.
(F)
The production of di-TMP according to any one of (A) to (E), wherein the amount of formaldehyde (1) is 9 to 100% based on the total molar amount of formaldehyde (1) and (2). Method.
(G)
The equivalent of base (I) and (II) is 0.9-2.5 equivalent with respect to a total of 1.0 mol of NBD and ECR, (A)-(F) Production method of di-TMP.
(H)
The production of di-TMP according to any one of (A) to (G), wherein the equivalent of the base (I) is 13 to 100% with respect to the sum of the equivalents of the bases (I) and (II) Method.

  According to the present invention, di-TMP can be efficiently produced from NBD by intermediate addition of ECR, divided addition of formaldehyde and divided addition of base. In addition, the amount of di-TMP produced can be increased, and the amount of by-product bis-TMP can be greatly reduced. In the method of the present invention, an unreacted raw material (formaldehyde) having a boiling point lower than that of di-TMP can be recovered by distillation and recycled, so that the present invention is an industrially extremely advantageous method.

The present invention comprises a first step of reacting NBD with formaldehyde (1) and base (I) to obtain a reaction mixture containing TMP and di-TMP, and ECR, formaldehyde (2) and / or base (II). In the second step of adding to the reaction mixture and allowing the reaction to proceed, di-TMP can be produced efficiently. The reactions occurring in the first and second stages of the present invention can be organized into the following three reaction formulas when the base is an alkali metal hydroxide (MOH). HCHO represents formaldehyde.
1.NBD + 3HCHO + MOH → TMP + HCOOM
2.NBD + HCHO → ECR + H ₂ O
3. TMP + ECR + 2HCHO + MOH → di-TMP + HCOOM (TMP + ECR + 2HCHO + H2O → di-TMP + HCOOH)
Combining the three reactions into one,
2NBD + 6HCHO + 2MOH → di-TMP + 2HCOOM + H ₂ O
The yield is calculated assuming that 1 mol of di-TMP is produced from 2 mol of NBD. The present invention will be described in further detail.

  As NBD and ECR used in the present invention, those which are generally commercially available are used as they are, or those which are further purified by distillation or the like. Of course, these can be synthesized and used by a generally known method. As ECR, it is also possible to use ECR produced as a by-product in the TMP production process, for example, recovered ECR containing organic components such as water and methanol.

  The ECR used in the present invention is preferably 0.1 to 10.0 mol, more preferably 0.3 to 7.0 mol, relative to 1.0 mol of NBD. Outside this range, the amount of di-TMP produced decreases.

  The formaldehyde used in the present invention may be an aqueous formaldehyde solution or solid paraformaldehyde. The aqueous formaldehyde solution usually contains several percent of methanol as a stabilizer, but can be used in the reaction after separation by distillation or the like if necessary.

  The total amount of formaldehyde (1) and (2) used in the present invention is based on the amount of formaldehyde used determined in a predetermined molar ratio from the total amount of NBD and ECR used. The total amount of formaldehyde (1) and (2) is preferably 2.0 to 10.0 moles, more preferably 2.5 to 5.0 moles, and still more preferably, relative to the total 1.0 moles of NBD and ECR. Is 3.0-4.0 mol.

  The amount of formaldehyde (1) is preferably 2.5 to 10.0 mol with respect to 1.0 mol of NBD, and the amount of formaldehyde (2) used is 2.0 to 10 with respect to 1.0 mol of ECR. More preferably, it is 0 mol. If the molar ratio is smaller than these ranges, the amount of di-TMP produced decreases and the by-products also increase. When the molar ratio is larger than this range, the amount of di-TMP produced relative to TMP decreases.

  As the bases (I) and (II) in the present invention, both inorganic bases and organic bases can be used. Examples of inorganic bases include sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide, and carbonates of alkali metal or alkaline earth metal hydroxides such as sodium carbonate, potassium carbonate, calcium carbonate, and lithium carbonate. Is mentioned. For industrial implementation, an inorganic base of sodium is common.

  As the organic base, aliphatic amine compounds, particularly tertiary amines such as trimethylamine, triethylamine, diethylmethylamine, dimethylethylamine, triisopropylamine, tributylamine and the like can also be used.

  These inorganic bases and organic bases are not only used alone, but also a plurality of bases, for example, triethylamine in combination with base (I), sodium hydroxide in base (II), or the use of a plurality in succession. Is possible. In the case of a base mainly composed of carbonate, carbonate is consumed in the reaction, and the hydrogen carbonate generated by the reaction is converted to carbonate by heating or the like and consumed in the reaction. This base may be a carbonate or a mixture with bicarbonate generally used as an industrial chemical. Further, a carbonate produced by oxidizing or hydrolyzing a formate salt as a raw material or a mixture with a bicarbonate may be used.

  The total amount of the bases (I) and (II) is preferably 0.9 to 2.5 equivalents, more preferably 1.0 to 1.1, based on 1.0 mol of the total amount of NBD and ECR used. 5 equivalents. For example, the amount of sodium carbonate that is 2 equivalents of base is preferably 0.9 to 2.5 equivalents (0.45 to 1.25 mol) with respect to a total of 1.0 mol of NBD and ECR. . If it is less than this range, not only a large amount of unreacted raw material remains, but also a side reaction from the unreacted raw material occurs. On the other hand, when the amount is larger than this range, a large amount of acid is required when neutralizing the excess base, which is not preferable.

<First stage>
Examples of the first stage reaction method of the present invention include a method of adding NBD and a base (I) in parallel to an aqueous formaldehyde (1) solution, or an aqueous formaldehyde (1) solution and a carbonate first as main components. Such a method of mixing an aqueous solution of base (I) and adding NBD dropwise thereto at a constant rate, a method of simultaneously adding NBD, base (I) and formaldehyde (1) are used. NBD, base (I), and formaldehyde (1) are added in order or in parallel, each of which is added continuously over 1 to 300 minutes. The addition may be finished first.

  The amount of formaldehyde (1) is preferably 9 to 100%, more preferably 23 to 95%, based on the molar sum of formaldehyde (1) and (2). If it is less than this range, the TMP production reaction hardly proceeds, and side reactions between raw material NBDs and ECRs easily occur.

  The equivalent of the base (I) is preferably 13 to 100%, more preferably 23 to 95%, based on the total equivalent of the bases (I) and (II). If it is less than this range, not only the TMP production reaction will proceed but also side reactions between raw NBDs and between ECRs will easily occur.

  The reaction temperature of the first stage NBD and formaldehyde (1) is preferably 0 to 120 ° C, more preferably 20 to 110 ° C. After completion of the addition of NBD, the reaction can be further advanced by heating at 0 to 120 ° C. for 1 to 300 minutes. In this case, in order to keep the inside of the system at a predetermined reaction temperature, pressurization may be performed with an inert gas such as nitrogen gas.

<Second stage>
The reaction formula of TMP, ECR, unreacted residual formaldehyde (1) or formaldehyde (2), and base (II) in the reaction mixture of the second stage of the present invention is represented by the formula (1). The formic acid produced by the formula (1) becomes a formate with a base.

After obtaining a reaction mixture of TMP and di-TMP by the first stage reaction, ECR and formaldehyde (2) and / or base (II) are added to the reaction mixture to perform the second stage reaction.

The amount of formaldehyde (2) and / or base (II) used in the second stage is the amount of base (I) and (II) determined at a predetermined ratio from the total amount of NBD and ECR used. Based on the total amount and the total amount of formaldehyde (1) and (2), the remaining formaldehyde (2) and base (II) added during the first stage reaction are used. As for the method of adding ECR and formaldehyde (2) and / or base (II), each of them is added in order or simultaneously in parallel, and continuously added over 1 to 300 minutes. Any of the above may be terminated first.

  The reaction temperature in the second stage depends on the type of base used, but is preferably 0 to 120 ° C, more preferably 20 to 120 ° C. In particular, when carbonate is used as the base (II), it is necessary to maintain a temperature at which the reaction from the hydrogen carbonate generated in the reaction to the carbonate sufficiently proceeds, and this temperature is preferably 60 to 120 ° C. More preferably, it is 80-120 degreeC. Even in this reaction, in order to keep the inside of the system at a predetermined reaction temperature, it is possible to pressurize with an inert gas such as nitrogen gas.

  If the reaction is insufficient when the addition of the second stage ECR and formaldehyde (2) and / or base (II) is completed, the reaction is completed by heating further. The reaction temperature in this case is preferably 0 to 120 ° C, more preferably 20 to 120 ° C, although it depends on the type of base used. In particular, when carbonate is used as the base (II), it is necessary to maintain a temperature at which the reaction from the hydrogen carbonate generated in the reaction to the carbonate sufficiently proceeds, and this temperature is preferably 60 to 120 ° C. More preferably, it is 80-120 degreeC. Even in this reaction, it is possible to pressurize with an inert gas such as nitrogen gas in order to keep the inside of the system at a predetermined reaction temperature.

  The time required for completion of the reaction by heating after the addition of ECR and formaldehyde (2) and / or base (II) in the second stage is preferably from 1 to 180 minutes, more preferably from 30 to 120 minutes. is there. If it is longer than this range, the reaction solution may be colored.

  After the completion of the second stage reaction, any unreacted raw material ECR is recovered. This separation and recovery can be easily performed by distillation under reduced pressure, normal pressure or pressurized conditions. The distillate obtained here contains components such as water and methanol in addition to ECR, but the distillate can be used in the next reaction as it is or after purification by distillation or the like.

<Di-TMP isolation>
Isolation and purification of the target di-TMP from the reaction mixture after completion of the second stage reaction can be carried out by operations generally performed in TMP purification, and the method is not particularly limited. After neutralizing the liquid, the raw material formaldehyde is recovered, extracted, and then recovered and purified by distillation or crystallization.

  All the reactions and operations of the first and second steps and di-TMP isolation of the present invention may be carried out in a dedicated apparatus for each reaction or operation. It may be performed by one or a plurality of apparatuses that can cope with the above.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, of course, this invention is not limited by these Examples. The raw material used in this example was a commercially available reagent. Formaldehyde aqueous solution is a product of Mitsubishi Gas Chemical Co., Ltd., NBD is a special grade product of Aldrich, sodium carbonate is a special grade product of Wako Pure Chemical Industries, Ltd. Used a recovered product of 13% water, 6% methanol, 3% organic components other than methanol, and 78% ECR. The analysis was performed using gas chromatography (GC) by diluting the sample and the internal standard sample with an acetone solvent.
[Gas chromatography analysis conditions]
Equipment: HP-5890 (manufactured by Agilent Technologies)
Column used: DB-1 (manufactured by Agilent Technologies)
Analysis conditions: Injection Temp 250 ° C.
Detector Temp 250 ° C
Column temperature: 60 ° C., hold for 6 minutes → heat up to 250 ° C. at 7 ° C./minute→250° C., hold for 20 minutes Detector: Hydrogen flame ionization detector (FID)

Example (Synthesis example with addition of ECR, split addition of formaldehyde, batch addition of base)
First stage: To a 1000 ml four-necked flask equipped with a reflux condenser, a thermometer, and two dropping funnels, 181 g of a 40% by weight aqueous formaldehyde (1) solution (2.4 mol as formaldehyde, 79 of the total amount of formaldehyde used) %) And heated to 74 ° C. Thereafter, while gradually heating to 94 ° C., 54 g (0.75 mol) of NBD having a purity of 99.9% and 263 g of a 21 mass% sodium carbonate (I) aqueous solution (0.53 mol = 1.06 equivalents as sodium carbonate, total The total amount (corresponding to 100% of the base used) was added in 25 minutes using two dropping funnels, and heated and held at 94 ° C. for 60 minutes to obtain a reaction mixture.
Second stage: In the reaction mixture, purity of 78% ECR 21 g (0.2 mol as ECR) and 103 g of 18 wt% formaldehyde (2) aqueous solution (0.62 mol as formaldehyde, corresponding to 21% of the total use amount of formaldehyde) Were added to the reaction mixture in 48 minutes and 90 minutes, respectively, while maintaining the temperature of the reaction mixture at 98 ° C. with two dropping funnels. After completion of the dropwise addition, the mixture was further heated and held at 100 ° C. for 60 minutes, and then the reaction mixture was analyzed by GC analysis to calculate TMP as 74 g, di-TMP as 27 g, and bis-TMP as 3 g. The yield of each raw material based on NBD was 74.0% for TMP, 28.8% for di-TMP, and 2.9% for bis-TMP. The yield based on the total of ECR and NBD was 58.4% for TMP, 22.8% for di-TMP, and 2.3% for bis-TMP.

Comparative example (conventional production method: no ECR added, formaldehyde and base added together)
In a 1000 ml four-necked flask equipped with a reflux condenser, a thermometer, and two dropping funnels, a total amount of 297 g of a 32 mass% aqueous formaldehyde solution (3.2 mol as formaldehyde) was charged and heated to 73 ° C. Thereafter, while gradually heating to 89 ° C., 72 g (1.0 mol) of NBD having a purity of 99.9% and 264 g of 21 mass% sodium carbonate aqueous solution (0.53 mol = 1.06 equivalents as sodium carbonate) were added from the dropping funnel. All amounts were added at 184 minutes and 25 minutes, respectively. After completion of the addition, the mixture was heated at 89 ° C. for 180 minutes to obtain a reaction mixture. By GC analysis of the obtained reaction mixture, it was calculated that TMP was 90.8 g, di-TMP was 3.9 g, and bis-TMP was 2.2 g. The yield of each raw material based on NBD was 67.7% for TMP, 3.1% for di-TMP, and 1.6% for bis-TMP.

  High-purity di-TMP is effectively used as a raw material for polyacrylates, polyether polyols, polyurethanes, alkyd resins, synthetic lubricating oils and the like. By the method of the present invention, di-TMP can be obtained efficiently.

Claims (8)

  A first step of reacting normal butyraldehyde with formaldehyde (1) and base (I) to obtain a reaction mixture containing trimethylolpropane and ditrimethylolpropane, and 2-ethyl-2-propenal with formaldehyde (2) and A method for producing ditrimethylolpropane comprising the second step of adding a base (II) to the reaction mixture and allowing the reaction to proceed. The method for producing ditrimethylolpropane according to claim 1, wherein the amount of 2-ethyl-2-propenal is 0.1 to 10.0 mol with respect to 1.0 mol of normal butyraldehyde. The method for producing ditrimethylolpropane according to claim 1 or 2, wherein the amount of formaldehyde (1) is 2.5 to 10.0 moles with respect to 1.0 mole of normal butyraldehyde. The amount of formaldehyde (2) is 2.0 to 10.0 mol with respect to 1.0 mol of 2-ethyl-2-propenal. 4. The ditrimethylolpropane according to any one of claims 1 to 3 Production method. The total amount of formaldehyde (1) and (2) is 2.0-10.0 mol with respect to the total 1.0 mol of normal butyraldehyde and 2-ethyl-2-propenal. The manufacturing method of the ditrimethylol propane of any one of Claims 1. The method for producing ditrimethylolpropane according to any one of claims 1 to 5, wherein the amount of formaldehyde (1) is 9 to 100% based on the total molar amount of formaldehyde (1) and (2). The equivalent of base (I) and (II) is 0.9-2.5 equivalent with respect to a total of 1.0 mol of normal butyraldehyde and 2-ethyl-2-propenal. A process for producing ditrimethylolpropane according to claim 1. The method for producing ditrimethylolpropane according to any one of claims 1 to 7, wherein the equivalent amount of the base (I) is 13 to 100% with respect to the total equivalent amount of the bases (I) and (II).