JP2015013815A - Production method of guerbet alcohol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a high quality Guerbet alcohol having low carbonyl value.SOLUTION: A production method of a Guerbet alcohol includes following steps: a step (I) dimerizing a primary fatty alcohol in 190-250°C under the presence of base catalysts of 0.12-1.0 mol/kg for the primary fatty alcohol which is a raw material, and under a condition with a metal catalyst under 5 mg/kg for the primary fatty alcohol which is the raw material; and a step (II) holding for 1-6 hours in 80-180°C under the presence of the base catalyst of 0.04-0.12 mol/kg for the primary fatty alcohol which is the raw material after the step (I).

Description

  The present invention relates to a method for producing Gerve alcohol.

  Gerve alcohol is a β-branched alcohol synthesized by Guerbet reaction that dimerizes raw alcohol, and is used directly or as an intermediate raw material in the fields of surfactants, fiber oils, softeners, cosmetics, pharmaceuticals, lubricants, etc. It is a useful substance. In recent years, in applications such as cosmetics and lubricating oils, Gerve alcohol with less impurities has been demanded from the viewpoint of product odor and performance.

Patent Document 1 discloses a method for self-condensing an aliphatic alcohol in the presence of a strong base typified by an alkali metal hydroxide and / or a metal catalyst and / or a mineral oxide at a temperature of 195 ° C. or higher under reduced pressure. Yes.
Patent Document 2 discloses a method for producing Gerve alcohol using an alkaline substance such as potassium hydroxide and palladium-supported carbon as a dehydrogenation catalyst.

JP-A-9-227424 International Publication No. WO2007 / 088625

The carbonyl number of Gerve alcohol can be reduced by methods such as distillation and hydrogenation. Generally, distillation of Gerve alcohol with a large number of carbon atoms requires high vacuum and high temperature. It is not economical because it requires new raw materials. There is a need for a method for easily and inexpensively producing low carbonyl gerber alcohol that does not depend on these methods. However, in the preparation method using the metal catalyst described in Patent Document 1 and Patent Document 2, the carbonyl value of Gerve alcohol after completion of the reaction is high, which is not preferable in terms of quality.
Then, this invention makes it a subject to provide the manufacturing method of Gerve alcohol from which Gerve alcohol with a low carbonyl value is obtained.

The present invention provides a method for producing Gerve alcohol having the following steps (I) and (II).
Step (I): The primary aliphatic alcohol is used in the presence of a base catalyst of 0.12 mol / kg or more and 1.0 mol / kg or less with respect to the primary aliphatic alcohol of the raw material. Step of dimerization at 190 ° C. or higher and 290 ° C. or lower with a condition of less than 5 mg / kg with respect to the primary aliphatic alcohol Step (II): After step (I), 0 with respect to the primary aliphatic alcohol as a raw material Step of holding at 80 ° C. or higher and 180 ° C. or lower for 1 hour or more and 6 hours or less in the presence of a base catalyst of 0.04 mol / kg or more and 0.12 mol / kg or less

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of Gerve alcohol which can obtain Gerve alcohol with a low carbonyl value can be provided.

Hereinafter, the present invention will be described in detail.
The method for producing Gerve alcohol of the present invention includes the following steps (I) and (II).
Step (I): The primary aliphatic alcohol is used in the presence of a base catalyst of 0.12 mol / kg or more and 1.0 mol / kg or less with respect to the primary aliphatic alcohol of the raw material. Step of dimerization at 190 ° C. or higher and 290 ° C. or lower with a condition of less than 5 mg / kg with respect to the primary aliphatic alcohol Step (II): After step (I), 0 with respect to the primary aliphatic alcohol as a raw material Step for holding at 80 ° C. or higher and 180 ° C. or lower for 1 hour or more and 6 hours or less in the presence of a base catalyst of 14 mol / kg or more and 0.12 mol / kg or less

  INDUSTRIAL APPLICABILITY The present invention can provide a method capable of reducing the carbonyl value by maintaining at a high temperature in a system in which a base catalyst remains after the reaction, and can provide a method for easily producing Gerve alcohol having a lower carbonyl value. .

[Step I]
<Raw material>
The primary aliphatic alcohol used as a raw material in the present invention is a hydrocarbon having a primary hydroxyl group, and preferably has 4 to 22 carbon atoms, and has 6 carbon atoms, from the viewpoint of remarkably achieving the effects of the present invention. -18 are more preferable, and those having 8-14 carbon atoms are more preferable. The primary aliphatic alcohol used in the present invention preferably has 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more from the viewpoint of reactivity. Moreover, the carbon number of the primary alcohol used in the present invention is preferably 22 or less, more preferably 18 or less, and still more preferably 14 or less, from the viewpoint of reactivity.

  The primary aliphatic alcohol of the present invention may be saturated or unsaturated, linear or branched, or have a cyclic structure. From the viewpoint of reactivity, a linear aliphatic alcohol is preferable, and a saturated aliphatic alcohol is preferable. preferable.

Specific examples of the primary aliphatic alcohol include 1-octanol, 6-methyl-1-heptanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, Examples include 1-pentadecanol.
These raw material alcohols can be used singly or in combination of two or more.

<Base catalyst>
In the present invention, examples of the base that can be used include inorganic bases and organic bases. Specific examples of the inorganic base include alkali metal hydroxides such as LiOH, NaOH, KOH, RbOH, CsOH, Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , Rb ₂ CO ₃ , Cs ₂ CO _{3 and the} like. Alkali metal carbonates such as LiHCO ₃ , NaHCO ₃ , KHCO ₃ , RbHCO ₃ , CsHCO _3, etc., methoxy sodium, ethoxy sodium, t-butoxy sodium, methoxy potassium, ethoxy potassium, t-butoxy potassium, etc. And alkali metal alkoxide compounds. These inorganic bases may be used as they are, but can also be used as an aqueous solution.

  Among these bases, bases having a relatively strong basicity capable of promoting dehydrogenation reaction and aldol condensation reaction are preferable, alkali metal hydroxides such as LiOH, NaOH, KOH, RbOH, CsOH, and methoxy sodium. Alkali metal alkoxide compounds such as ethoxysodium, t-butoxysodium, methoxypotassium, ethoxypotassium, and t-butoxypotassium are more preferable, and KOH, methoxysodium, and t-butoxypotassium are more preferable from the viewpoint of versatility and economy. .

Said base catalyst can be used individually by 1 type or in combination of 2 or more types.
The amount of the base catalyst used is preferably 0.12 mol / kg or more, preferably 1.0 mol / kg or less, based on the primary aliphatic alcohol as a raw material, from the viewpoint of reaction rate and side reaction suppression. 54 mol / kg or less is more preferable, and 0.27 mol / kg or less is still more preferable.

<Gerbe reaction>
In the present invention, the primary aliphatic alcohol is reacted in the presence of a base catalyst. This reaction is a dehydration condensation reaction (Gerbe reaction), and when by-product water stays in the system, it promotes fatty acid production by the side reaction. Therefore, in order to improve the reaction rate and suppress side reactions, the reaction is preferably carried out while introducing nitrogen into the reaction system with stirring and removing the generated water from the system.
According to the production method of the present invention, the reaction temperature is appropriately determined in consideration of the boiling point of the raw material alcohol, but is preferably 190 ° C. or higher from the viewpoint of securing a sufficient reaction rate and obtaining high reaction efficiency. ° C or higher is more preferable, 220 ° C or higher is more preferable, 290 ° C or lower is preferable, 270 ° C or lower is more preferable, and 250 ° C or lower is further preferable.
The reaction time depends on the reaction temperature, raw material alcohol and the like, but is usually 1 hour or longer, preferably 20 hours or shorter, more preferably 10 hours or shorter.

  The pressure during the reaction may be any of reduced pressure, normal pressure, and pressurized, and is preferably 100 kPa or less, more preferably 80 kPa or less, and more preferably 60 kPa or less in order to advance the reaction efficiently. Is more preferable, and 1 kPa or more is preferable.

The reaction is preferably performed in an inert gas atmosphere. From the viewpoint of removing by-product water, it is preferable to distribute the inert gas as a carrier. As the inert gas, nitrogen, argon, carbon dioxide gas or the like is preferably used.
The inert gas can be circulated by a method of circulating the reaction solution above or a method of bubbling in the reaction solution. There is no particular limitation on the flow rate of the inert gas, but it is desirable to adjust the flow rate appropriately so that by-product water can be efficiently removed and loss due to entrainment is prevented. From the above viewpoint, the flow rate of the inert gas is preferably 0.02 L / h or more, more preferably 0.1 L / h or more, and further preferably 0.2 L / h or more per 1 kg of the reaction solution. Further, from the economical viewpoint, the flow rate of the inert gas is preferably 10 L / h or less, more preferably 2 L / h or less, and further preferably 1 L / h or less per 1 kg of the reaction solution.

  The alcohol conversion rate at the end of step (I) is preferably 40 mol% or more, more preferably 60 mol% or more from the viewpoint of productivity, and can prevent contamination by impurities due to overreaction, from the viewpoint of quality. Preferably it is 90 mol% or less, More preferably, it is 85 mol% or less.

In the step (I) of the present invention, the metal catalyst is substantially not contained. The metal catalyst referred to in the present invention is a catalyst containing a metal other than an alkali metal or an alkaline earth metal, for example, a transition metal catalyst, particularly a transition metal catalyst having dehydrogenation activity, specifically Cu. , Fe, Ni, Pt, Pd, Ru and the like.
The metal catalyst may be present within a range that does not impair the effects of the present invention, and is preferably less than 5 mg / kg, more preferably 2 mg / kg or less as a metal element with respect to the primary alcohol as a raw material, Preferably it is 0.5 mg / kg or less.
The amount of metal can be determined, for example, by ICP analysis.

[Step (II)]
<Base catalyst>
The base catalyst in step (II) may be the same as or different from the residue in step (I).
The base catalyst is reduced because it reacts with the acid produced by the disproportionation of the Gerde reaction intermediate aldehyde to produce soap. Therefore, the amount of the base catalyst may be only the residual base catalyst from step (I), may be further added with a base catalyst in step (II), or may be adjusted by adding an acid.

  The amount of the base catalyst in the step (II) is preferably 0.04 mol / kg or more, more preferably 0.06 mol / kg or more, from the viewpoint of the efficiency of the reaction with respect to the primary aliphatic alcohol of the raw material, From the viewpoint of preventing soap and hydrocarbon by-products, it is preferably 0.12 mol / kg or less, more preferably 0.11 mol / kg or less. Here, “raw primary aliphatic alcohol” means the amount of primary aliphatic alcohol used as a raw material in step (I).

<Holding temperature>
The holding temperature in the step (II) is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, more preferably 180 ° C. or lower, and more preferably 160 ° C. or lower from the viewpoint of reducing the carbonyl value of Gerve alcohol. The holding time is preferably 1 hour or longer, preferably 6 hours or shorter, more preferably 5 hours or shorter, and even more preferably 3 hours or shorter from the viewpoint of reducing the carbonyl value of Gerve alcohol.

The holding temperature of the step (II) is lower than the temperature of the step (I), and the difference of the holding temperature of the step (II) with respect to the temperature of the step (I) is an increase in by-products such as aldehyde and the quality of soap by-products. From the viewpoint of preventing the decrease, it is preferably 40 ° C. or higher, more preferably 60 ° C. or higher, and from the viewpoint of reducing the carbonyl value, it is preferably 100 ° C. or lower, more preferably 90 ° C. or lower.
The reaction system may be cooled to 80 ° C. or lower once, and heated up to 80 ° C. or higher again and held in multiple steps.

This step (II) reduces the carbonyl value.
The carbonyl value of the resulting Gerve alcohol is preferably 3.0 μmol / g or less, more preferably 2.5 μmol / g or less, still more preferably 2.0 μmol / g or less. From the viewpoint of productivity, 0.01 μmol / g g or more.

  The reason is not necessarily clear, but it is presumed that the production rate of the intermediate aldehyde is low and the hydrogenation reaction of the aldehyde is sufficiently fast.

  The gel alcohol obtained by the method of the present invention can be purified by a distillation operation or the like as necessary, but since it has high purity, it can be used for various applications as it is. Gerve alcohol is useful as a raw material or intermediate raw material for surfactants, fiber oils, softeners, cosmetics, pharmaceuticals, lubricating oils, and the like. From the viewpoint of use in these applications, the purity of Gerve alcohol is preferably 95% by mass or more.

  Examples and Comparative Examples are shown below, but are not limited thereto. Various measurement methods and physical property evaluation methods are shown below.

Example 1
(Process I)
In a flask equipped with a stirrer, 600.0 g (3.22 mol) of 1-dodecanol (manufactured by Kao Corporation, product name: Calcoal 2098), 11.3 g of 48% potassium hydroxide aqueous solution (manufactured by Kishida Chemical Co., Ltd.) as a base catalyst ( 0.16 mol / kg vs. 1-dodecanol), while stirring, nitrogen was circulated in the system at 240 ° C. (nitrogen circulation amount: 2.3 mL / min), vacuum degree 50 kPa, 3.5 hours, reaction Went. In addition, although potassium hydroxide usually contains iron, aluminum and other metal components, those having a content of 100 mg / kg or less are used, and metal components other than alkali metals or alkali metals in the reaction system are 0.5 mg / kg. Does not exceed kg.
The solution after completion of the reaction was diluted with hexane, followed by gas chromatography (column: Ultra-alloy capillary column 30.0 m × 250 μm (manufactured by Frontier Laboratories), detector: FID, injection temperature: 300 ° C., detector temperature: 300 ° C. He flow rate 4.6 mL / min. The product was quantified.
As a result, the alcohol conversion was 40%, and the Gerve alcohol yield was 36%. The carbonyl value was 3.2 μmol / g, and the alkali concentration was 0.10 mol / kg.
(Process II)
After the reaction, the mixture was stirred at 160 ° C. for 4 hours under 31 kPa. The gerbe alcohol obtained had a carbonyl value of 1.9 μmol / g.

The alcohol conversion rate and Gerve alcohol yield were calculated from the following formulas from the results of gas chromatography.
Alcohol conversion rate (%) = 100− [Amount of residual alcohol (mol) / Amount of raw material alcohol (mol)] × 100
Yield of Gerve alcohol (%) = [Amount of formed Gerve alcohol (mole) × 2 / Amount of raw material alcohol charged (mole)] × 100
The carbonyl value was measured in accordance with “Oil Analytical Test Method 2.3.4 (1996)” established by the Japan Oil Chemists' Society.
The alkali concentration in the step (II) was determined from the acid value [mg KOH / g] measured according to “Standard Oil Analysis Test Method 2.3.1 (1996)” established by the Japan Oil Chemists' Society according to the following formula.

Examples 2-4, Comparative Examples 1-3
Examples 2 to 4 and Comparative Examples 1 to 3 were performed in the same manner as in Example 1 except that the conditions of Step (I) and Step (II) were changed to the conditions shown in Table 1 below.
Production conditions and results are shown in the table.
In the table, the pressure “[−4h] 50 → [−6h] 31” in the step (I) in the table indicates that the pressure up to 4 hours is 50 kPa, and then the pressure up to 6 hours is 31 kPa. (Other notations follow this as well.)

From the table, according to the production method of Example 1, it reacts at 50 kPa for 3.5 hours, and in step (I), the alcohol conversion is 40% and the carbonyl value is 3.2 μmol / g. Thereafter, in step (II), at an alkali concentration of 0.10 mol / kg, by cooling to 160 ° C. and holding for 4 hours, it can be seen that Gerve alcohol having a carbonyl value of 1.9 μmol / g can be obtained in a yield of 36%.
In Example 2, the reaction for 6 hours gives an alcohol conversion of 85% and a carbonyl value of 6.6 μmol / g in step (I). Thereafter, in step (II), at an alkali concentration of 0.05 mol / kg, by cooling to 160 ° C. and holding for 4 hours, it can be seen that Gerve alcohol having a carbonyl value of 2.8 μmol / g can be obtained with a yield of 81%.
On the other hand, in Comparative Example 1 in which the low temperature holding is not performed, the carbonyl value is 4.3 μmol / g even if the alkali concentration is 0.05 mol / kg in the step (II).
Moreover, in Comparative Example 2, when the alkali concentration is 0.01 mol / kg and the low-temperature holding is performed at 160 ° C. for 4 hours, the carbonyl value of Gerve alcohol becomes 6.8 μmol / g. That is, it can be seen that, after the reaction, the carbonyl value is reduced by holding at a low temperature in a system having a sufficient alkali concentration, and a higher-quality gel alcohol is obtained.
In Example 3, it can be seen that when the alkali concentration is 0.09 mol / kg and the low-temperature holding is performed at 160 ° C. for 1 hour in Step (II), Gerve alcohol having a carbonyl value of 2.0 μmol / g is obtained. From this, it can be seen that in a system having a sufficient alkali concentration, the effect can be obtained even by holding at a low temperature for 1 hour.
Comparing Example 4 and Comparative Example 3, in Example 4 having an alkali concentration of 0.08 mol / kg and Comparative Example 3 having a concentration of 0.03 mol / kg, even if low temperature holding at 100 ° C. for 4 hours was performed, It can be seen that the obtained effects are different. It can be seen that the alkali concentration is greatly involved in carbonyl reduction.

Comparative Example 4
According to the production method of Comparative Example 6 described in Patent Document 1, Guerbet alcohol was produced.
That is, stearyl alcohol (Kao Corporation, product name: Calcoal 8098), potassium hydroxide (Katayama Chemical Co., Ltd.) 1% by weight (0.18 mol / kg) and 5% Pd-supported carbon (NE CHEMCAT) 100 mg / kg), and reacted at 220 ° C. for 10 hours under 200 Torr (26.7 kPa). The alcohol conversion was 95%, the alkali concentration after the reaction was 0.08 mol / kg, and Gerve alcohol having a carbonyl value of 8.5 μmol / g was obtained. Thereafter, holding at 80 ° C. for 170 minutes gave a carbonyl value of 8.7 μmol / g. From this, it can be seen that in the system using a metal catalyst, the carbonyl reduction effect cannot be obtained even if Step 2 is performed.

  As described above, the present invention is extremely advantageous as a method for producing high-quality Gerve alcohol.

Claims (4)

The manufacturing method of Gerve alcohol which has the following process (I) and process (II).
Step (I): The primary aliphatic alcohol is used in the presence of a base catalyst of 0.12 mol / kg or more and 1.0 mol / kg or less with respect to the primary aliphatic alcohol of the raw material. Step of dimerization at 190 ° C. or higher and 290 ° C. or lower with a condition of less than 5 mg / kg with respect to the primary aliphatic alcohol Step (II): After step (I), 0 with respect to the primary aliphatic alcohol as a raw material Step of holding at 80 ° C. or higher and 180 ° C. or lower for 1 hour or more and 6 hours or less in the presence of a base catalyst of 0.04 mol / kg or more and 0.12 mol / kg or less   The method for producing Gerve alcohol according to claim 1, wherein the base catalyst is an alkali metal hydroxide.   3. The method for producing Gerve alcohol according to claim 1, wherein the primary aliphatic alcohol is a primary linear aliphatic alcohol having 8 to 14 carbon atoms.   4. The method for producing Gerve alcohol according to claim 1, wherein the step (I) is performed until the reaction conversion rate of the primary aliphatic alcohol is 40% or more and 90% or less. 5.