JP2000246100A - Catalyst for alkylene oxide addition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst which exhibits a high catalytic activity in an alkylene oxide addition reaction and enables an adduct with a low COV value to be efficiently obtained by using a composite oxide containing Mg atom, Ca atom, and Si atom as the catalyst. SOLUTION: The atomic ratio of Ca/Mg is preferably about 0.001-1.0, still preferably about 0.005-0.5, in terms of the reaction rate of alkylene oxide addition and the product quality. The atmic ratio of Si/Mg is preferably about 0.005-7.0, still preferably about 0.01-1.0. The catalyst is prepared by suspending an SiO2 powder in ion-exchanged water under stirring, dropping an aqueous solution of a mixture of magnesium nitrate hexahydrate and calcium nitrate tetrahydrate and an aqueous solution of sodium hydroxide to the suspension to subject it to precipitation reaction, then separating the resultant solid component by filtration, washing the solid component with ion-exchanged water, drying the component, and baking it in an inert gas or a vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catalyst for adding an alkylene oxide and a method for producing an alkylene oxide adduct using the catalyst.

[0002]

2. Description of the Related Art As a catalyst used in a reaction for adding an alkylene oxide to an active hydrogen-containing organic compound such as alcohol or phenol, for example, a composite oxide catalyst of Mg atom and Si atom is known. However, when a composite oxide catalyst of Mg atoms and Si atoms is used, the resulting alkylene oxide adduct is colored yellow and further has an aldehyde odor due to the influence of the acid by the Si atoms. Emits. Also, it has a disadvantage that the carbonyl value (hereinafter referred to as COV value) of the alkylene oxide adduct becomes extremely high. Furthermore, when the COV value of the alkylene oxide adduct is high, the quality of the derivative obtained through this also deteriorates remarkably. Conversely, if the amount of Si atoms in the catalyst is reduced, desired reaction activity cannot be obtained.

An object of the present invention is to provide a catalyst having good catalytic activity in an alkylene oxide addition reaction and capable of efficiently obtaining an adduct having a low COV value.

[0004]

SUMMARY OF THE INVENTION The present invention provides a catalyst for adding an alkylene oxide comprising a composite oxide containing Mg, Ca and Si atoms, and an active hydrogen-containing organic compound and an alkylene oxide in the presence of the catalyst. To produce an alkylene oxide adduct.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The Ca / Mg atomic ratio in the catalyst of the present invention is preferably from 0.001 to 1.0, and more preferably from 0.005 to 0.5 from the viewpoint of the rate of alkylene oxide addition reaction and the quality of the product.
Is more preferred. The Si / Mg atomic ratio is preferably from 0.005 to 7.0, more preferably from 0.01 to 1.0.

[0006] The catalyst of the present invention may be produced by any of a coprecipitation method, an impregnation method and the like. A typical production method includes the following coprecipitation method. First, SiO ₂ powder is suspended in ion-exchanged water and stirred. The SiO ₂ powder preferably has a BET surface area of at least 600 m ² / g in view of the activity of the obtained catalyst. A mixed aqueous solution of magnesium nitrate hexahydrate, calcium nitrate tetrahydrate and an aqueous solution of sodium hydroxide are added dropwise to perform a precipitation reaction. The mixing ratio of magnesium nitrate hexahydrate and calcium nitrate tetrahydrate in the mixed aqueous solution is preferably such that the Ca / Mg atomic ratio falls within the above range from the viewpoint of the performance of the obtained catalyst. In addition, it is preferable to adjust the supply rate of the aqueous sodium hydroxide solution to make the precipitation reaction uniform, and to carry out the reaction at a constant pH within the range of pH 7 to 13. The amount of the mixed aqueous solution of magnesium and calcium to be supplied is preferably such that the Si / Mg atomic ratio in the system is within the above range. After the precipitation reaction is performed in this manner, the supply of each aqueous solution is stopped, and the suspension is aged by stirring for 1 hour or more. Thereafter, the solid content is separated by filtration and washed with ion-exchanged water. Since Na ⁺ ions contained in the raw material become catalyst poisons, the washing is preferably continued until no Na ⁺ ions are detected in the washing solution. The solids thus obtained are dried in a warm air dryer at 60-130 ° C, preferably at 80-120 ° C.
After drying for 12 hours or more, in an inert gas or vacuum
The catalyst is obtained by calcining at 400 to 1000 ° C, preferably 500 to 800 ° C. The calcined catalyst is cooled in an inert gas or vacuum in order to prevent adsorption of moisture or carbon dioxide gas in the air, and further cooled. It is preferable to immerse in an object or store in a vacuum.

The active hydrogen-containing organic compound used in the present invention may be any compound as long as it can be alkoxylated with an alkylene oxide. However, alcohols, phenols, polyols, carboxylic acids, thiols, amines And amides. Among these, alcohols are preferred, and the alcohols are preferably linear or branched primary or secondary alcohols having 1 to 30 carbon atoms, and more preferably primary alcohols having 6 to 24 carbon atoms.

The alkylene oxide used in the present invention may be any one capable of reacting with an active hydrogen-containing organic compound to form an alkylene oxide adduct. Is preferably epoxidized, and ethylene oxide, propylene oxide or a mixture thereof is particularly preferred.

The reactor used for the reaction between the active hydrogen-containing organic compound and the alkylene oxide may be any of a stirred tank batch type, a stirred tank flow type, a fixed bed flow type, and the like. Considering the complexity, a fixed bed circulation type is preferable.

In the use in a batch reactor, the amount of the catalyst used in the present invention is usually based on the amount of the active hydrogen-containing organic compound.
It is preferably from 0.1 to 20% by weight, more preferably from 0.5 to 8% by weight. The reaction temperature is preferably from 80 to 230 ° C, more preferably 1 to 30, from the viewpoints of reaction rate, product selectivity, and decomposition temperature.
20-180 ° C, most preferably 120-160 ° C. The reaction pressure depends on the reaction temperature, but is preferably 2 MPa absolute pressure or less, more preferably 0.2 to 1 MPa absolute pressure.

When the catalyst is used in powder form, for example, an active hydrogen-containing organic compound and a catalyst are charged into a reactor,
After introducing and reacting the alkylene oxide under a predetermined temperature and pressure condition in a nitrogen atmosphere, the reaction can be carried out by cooling and filtering off the catalyst. When used in a molded article, the molded catalyst is put into a stirring blade having a basket made of, for example, a stainless steel wire, and this and an active hydrogen-containing organic compound are charged into a reactor. After introducing and reacting the alkylene oxide under the temperature and pressure conditions described above, the reaction can be carried out by cooling and extracting only the generated alkylene oxide adduct.

When the reaction is carried out in a fixed bed flow system, the fixed catalyst of the present invention is charged into a fixed bed flow reactor, and an alkylene oxide and an organic compound containing active hydrogen are passed through the reactor. Preferably 0.1～100H ^-1 at a liquid passage rate liquid hourly space velocity of the liquid components containing the alkylene oxide adduct, more preferably 0.2 to 70 h ^-1, particularly preferably 1 to 50 h ^-1. The reaction tube pressure is preferably from 0.1 to 3 MPa absolute pressure, more preferably from 0.2 to 2 MPa absolute pressure, particularly preferably from 0.2 to 1.5 MPa absolute pressure. The reaction temperature is preferably from 50 to 300 ° C, more preferably from 80 to 250 ° C, particularly preferably from 100 to 230 ° C. When a lower alkylene oxide, particularly ethylene oxide, is used as the alkylene oxide, it is preferable to carry out the reaction in a nitrogen atmosphere in order to reduce the risk of explosion.

When a molded article is used as the catalyst of the present invention,
The resulting alkylene oxide adduct does not contain the component metal of the catalyst, and after the reaction as in the case of using a conventional catalyst, the alkylene oxide adduct and the catalyst do not require a separation treatment such as filtration and centrifugation. is there.

According to the present invention, an alkylene oxide adduct having a COV value of preferably 5 μmol / g or less can be obtained.

[0015]

The percentages in the following examples are by weight unless otherwise specified.

Example 1 [Preparation of catalyst] A flask was charged with 1000 g of ion-exchanged water and 52 g of SiO ₂ powder (Mizukasil P-707, manufactured by Mizusawa Chemical Co., Ltd.) and stirred at 300 r / min with a constant speed stirrer. Here, 1026 g of magnesium nitrate hexahydrate and 47 g of calcium nitrate tetrahydrate
An aqueous solution (hereinafter referred to as a solution) dissolved in 2000 g of ion-exchanged water and a 5N aqueous sodium hydroxide solution (hereinafter referred to as a solution) were simultaneously supplied. The solution was supplied at 20 mL / min, and the supply rate of sodium hydroxide was 12.5 ± 0 with the pH of the system.
Adjusted to be 5. After the entire amount of the solution was supplied, the suspension was aged for 1 hour with stirring. The obtained suspension was filtered, and the obtained white solid was sufficiently washed with ion-exchanged water. After washing, it was dried in a hot air dryer at 80 ° C. for 12 hours. The dried white solid is placed in a nitrogen stream at 600
C. for 2 hours. The Ca / Mg atomic ratio of the obtained catalyst is 0.1.
05, the Si / Mg atomic ratio was 0.22.

[Production of alkylene oxide adduct] Into an autoclave, 300 g of lauryl alcohol and 4% of the above catalyst were added to the alcohol, and the system was purged with nitrogen. The temperature rose.
At the same temperature, 213 g of ethylene oxide (hereinafter referred to as EO) was introduced while maintaining the pressure at 0.3 to 0.5 MPa absolute pressure to carry out the reaction. After aging, the mixture was cooled to 80 ° C and the catalyst was filtered off at 20 ° C. The average number of moles of EO added to the obtained ethoxylate was determined by gas chromatography to be 3.0, and the reaction rate was as shown in Table 1. The COV value of the obtained ethoxylate was measured by the following method. Table 1 shows the results.

<Method of measuring COV value>
The color was developed with -dinitrophenylhydrazine, the absorbance was measured at 435 nm, the number of μmol of the carbonyl compound in 1 g of the sample was determined from the calibration curve, and this was defined as the COV value.

Comparative Example 1 An Mg / Si catalyst was prepared in the same manner as in Example 1 except that calcium nitrate tetrahydrate was not added. Using the obtained composite oxide catalyst of Mg atoms and Si atoms, an alkylene oxide adduct was produced in the same manner as in Example 1. The average EO addition mole number of the obtained ethoxylate is 3.0,
The reaction rates were as shown in Table 1. The COV value of the obtained ethoxylate was measured by the above method. Table 1 shows the results.

[0020]

[Table 1]

As is apparent from Table 1, the COV value of the ethoxylate obtained in Example 1 was improved to 1/30 of the ethoxylate obtained in Comparative Example 1, and the ethylene oxide addition reaction rate was improved. It has tripled.

[0022]

According to the present invention, an alkylene oxide adduct having a small amount of by-products in the reaction product can be efficiently produced, which is extremely valuable in industry.

Continued on the front page (72) Inventor Osamu Tabata 1334 Minato, Wakayama City, Wakayama Pref. CA61 CF90

Claims (2)

[Claims] 1. A catalyst for adding an alkylene oxide, comprising a composite oxide containing an Mg atom, a Ca atom and a Si atom. 2. A method for producing an alkylene oxide adduct, comprising reacting an active hydrogen-containing organic compound with an alkylene oxide in the presence of the catalyst according to claim 1.