JP6912681B1 - Method for producing secondary alcohol alkoxylate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for mass-producing a secondary alcohol alkoxylate having less coloring.
SOLUTION: An alkylene oxide is a secondary alcohol alkoxylate precursor via an inlet of a tubular reactor and an alkylene oxide supply unit installed at n places (n is an integer of 2 or more) other than the inlet. In addition to the above, the secondary alcohol alkoxylate precursor is reacted with the alkylene oxide in the tubular reactor, and the alkylene oxide supply unit has the formula (1): N [X _n'. , X _{n'+ 1} ] / (n-1)> 0.4, and the alkylene oxide is further added to the formula (2): N [Y _{n "} , Y _{n" + 1.} ] / A method for producing a secondary alcohol alkoxylate, which is added to the secondary alcohol alkoxylate precursor so as to satisfy n ≧ 0.3.
[Selection diagram] None

Description

The present invention relates to a method for producing a secondary alcohol alkoxylate.

Secondary alcohol alkoxylates, including secondary alcohol ethoxylates, are widely used as nonionic surfactants because they have a low pour point and are easy to handle. This secondary alcohol alkoxylate is obtained in the presence of an alkaline catalyst such as sodium hydroxide, potassium hydroxide, sodium alkoxide or an acidic catalyst such as boron trifootate, boron trifootide-complex, antimony pentoxide, tin tetrachloride or the like. It is produced by adding an alkylene oxide using a secondary alcohol as a starting material (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 61-186337

In recent years, from the viewpoint of increasing added value, there has been a demand for a technique for mass-producing secondary alcohol alkoxylates with less coloring.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a means for producing a large amount of a secondary alcohol alkoxylate having less coloring.

The present inventors have conducted diligent research in order to solve the above problems. As a result, when the alkylene oxide is supplied at a plurality of locations in the tubular reactor (reaction tube) to react the secondary alcohol with the alkylene oxide, the alkylene oxide is supplied at a specific ratio with a long supply interval and the supply amount. The present invention has been completed by finding that the above-mentioned problems can be solved by supplying a large amount of alcohol.

That is, the above purpose is to use a secondary alcohol alkoxylate for alkylene oxide via an alkylene oxide supply unit installed at the inlet of the tubular reactor and n places (n is an integer of 2 or more) other than the inlet. The secondary alcohol alkoxylate precursor is added to the precursor to react with the alkylene oxide in the tubular reactor, and the alkylene oxide supply unit satisfies the following formula (1). Can be achieved by a method for producing a secondary alcohol alkoxylate, which is installed in the tubular reactor and further adds the alkylene oxide to the secondary alcohol alkoxylate precursor so as to satisfy the following formula (2). :

According to the present invention, a secondary alcohol alkoxylate with reduced coloring can be mass-produced.

FIG. 1 is a schematic diagram illustrating an embodiment of a manufacturing process of the present invention. FIG. 2 is a diagram showing an example of a tubular reactor according to the present invention. Figure 3 is a 'supply of alkylene oxide unit P _n installed in _th' from the inlet side of the tubular reactor n, the supply of alkylene oxide unit P _n to be installed from the inlet side of the tube reactor n '+ 1 th It is a figure explaining the interval [X _{n' (m)] with'+1.}

Hereinafter, embodiments according to one embodiment of the present invention will be described. The present invention is not limited to the following embodiments.

In the present specification, "X to Y" indicating a range includes X and Y and means "X or more and Y or less". Unless otherwise specified, the operation and physical properties are measured under the conditions of room temperature (20 to 25 ° C.) / relative humidity of 40 to 50% RH.

<Manufacturing method of secondary alcohol alkoxylate>
In one embodiment of the present invention, the alkylene oxide is subjected to secondary alcohol alkoxy via the inlet of the tubular reactor and the alkylene oxide supply section installed at n places (n is an integer of 2 or more) other than the inlet. The secondary alcohol alkoxylate precursor is added to the rate precursor to react with the alkylene oxide in the tubular reactor, and the alkylene oxide supply unit satisfies the following formula (1). A method for producing a secondary alcohol alkoxylate, wherein the alkylene oxide is further added to the secondary alcohol alkoxylate precursor so as to satisfy the following formula (2). One side):

When a secondary alcohol alkoxylate (particularly a secondary alcohol ethoxylate) is used as a surfactant, it is useful to increase the number of moles of alkylene oxide added to the secondary alcohol alkoxylate in order to increase the water solubility. .. Further, when the secondary alcohol alkoxylate is mass-produced, it is preferable to continuously produce it instead of the batch type. As a continuous production method, there is a method of using a tubular reactor (reaction tube). Therefore, the present inventors have studied the continuous production of a secondary alcohol alkoxylate having a large number of added moles using a tubular reactor (reaction tube), and found that the secondary alcohol It has been found that the hue of the alkoxylate may increase (the secondary alcohol alkoxylate may be colored). Therefore, the present inventors have diligently studied the means for reducing the coloration of the secondary alcohol alkoxylate having a high number of moles of alkylene oxide added in the continuous production method. As a result, the alkylene oxide was added to the secondary alcohol in two steps (the primary alkoxylation reaction of adding the alkylene oxide to the secondary alcohol and the alkylene oxide to the secondary alcohol alkoxylate precursor obtained by the primary alkoxylation reaction). In the case of addition by the second alkoxylation reaction), the local addition reaction of the alkylene oxide to the secondary alcohol alkoxylate precursor at the time of the second alkoxylation reaction is considered to be one of the causes of the increase in hue. I guessed. Therefore, the control of the addition reaction of alkylene oxide to the secondary alcohol alkoxylate precursor was intensively studied. As a result, the alkylene oxide is divided and supplied to a secondary alcohol alkoxylate precursor (an alkylene oxide low molar adduct having a small number of alkylene oxide addition moles) in a plurality of supply units in a tubular reactor (reaction tube). When (split feed)
Equation (i) (1): N [X _n' , X _{n'+ 1} ] / (n-1)> 0.4 is satisfied, that is, the alkylene oxide supply interval is lengthened at a rate exceeding 40%. The alkylene oxide is supplied; and the equation (ii) (2): N [Y _{n "} , Y _{n" + 1} ] / n ≧ 0.3 is satisfied, that is, the supply amount is increased at a rate of 30% or more. , Supplying alkylene oxide,
It has been found that it is effective to produce the final product, a secondary alcohol alkoxylate having a high molar number of alkylene oxide adducts (high molar adduct of alkylene oxide). The split feed in a particular format as described above allows the alkylene oxide addition reaction to be adequately controlled, resulting in the coloring of the final product, the secondary alcohol alkoxylate (high molar adduct of alkylene oxide). I guess it can be reduced. Further, the above method is a continuous production method. Therefore, it is possible to mass-produce a secondary alcohol alkoxylate (high molar adduct of alkylene oxide) having reduced coloring. Therefore, according to the above configuration, a secondary alcohol alkoxylate (high molar adduct of alkylene oxide) with reduced coloring can be mass-produced.

It should be noted that the mechanism for exerting the above-mentioned effects and effects according to the constitution of the present invention is a guess, and the present invention is not limited to the above-mentioned guess.

Hereinafter, each step of the first aspect will be described with reference to the drawings. That is, as shown in FIG. 1, (i) a secondary alcohol alkoxylate precursor (alkylene oxide low molar adduct or low AO adduct) is produced (step (i)); (ii) said step (i). An alkylene oxide is added to the secondary alcohol alkoxylate precursor produced in i) in a tubular reactor (step (ii)) to produce a secondary alcohol alkoxylate. The following description shows an example of each step of the first aspect, and the present invention is not limited to the following.

(Step (i))
In this step, a secondary alcohol alkoxylate precursor (alkylene oxide low molar adduct or low AO adduct) is produced. The method for producing the secondary alcohol alkoxylate precursor is not particularly limited, and a known method can be applied in the same manner or appropriately modified. For example, (i-1) a secondary alcohol is reacted with an alkylene oxide in the presence of a catalyst to obtain an alkylene oxide adduct (first alkoxylation reaction step: “first alkoxylation reaction” in FIG. 1); i-2) The alkylene oxide adduct (reaction solution) obtained in the above step (i-1) is mixed with water and separated into an aqueous layer and an organic layer (cleaning step: “reaction solution cleaning” in FIG. 1). (I-3) A method comprising purifying the organic layer separated in the above step (i-2) (purification step: "light separation" and "rectification" in FIG. 1) can be used.

Hereinafter, the above embodiment will be described. However, the present invention is not limited to the following forms.

(Step (i-1))
In this step, a secondary alcohol is reacted with an alkylene oxide in the presence of a catalyst to obtain an alkylene oxide adduct (first alkoxylation reaction step: “first alkoxylation reaction” in FIG. 1).

The secondary alcohol, which is a raw material in the alkylene oxide addition reaction, has a hydroxyl group bonded to a carbon other than the terminal of a saturated aliphatic hydrocarbon (normal paraffin) having 11 to 15 carbon atoms represented by the following formula (A). Is a mixture of secondary alcohols.

In the above formula (A), the sum (x + y) of x and y is an integer of 8 to 12.

The secondary alcohol is a secondary alcohol (x + y is an integer of 8 to 12) formed by bonding a hydroxyl group to a carbon other than the terminal of a saturated aliphatic hydrocarbon having 11 to 15 carbon atoms. It is a mixture containing (secondary alcohol) as a main component (hereinafter, also simply referred to as “secondary alcohol”), and preferably, a hydroxyl group is bonded to a carbon other than the terminal of a saturated aliphatic hydrocarbon having 12 to 14 carbon atoms. It is a mixture containing a secondary alcohol (the secondary alcohol of the above formula (A) in which x + y is an integer of 9 to 11) as a main component. Here, "containing a secondary alcohol as a main component" means that a secondary alcohol having a predetermined carbon number is contained in an amount of more than 90% by mass (preferably more than 95% by mass) with respect to the secondary alcohol (upper limit: 100). It means that it is contained in the ratio of mass%). The average molecular weight of the secondary alcohol is 158 or more and 228 or less, preferably 186 or more and 214 or less. The secondary alcohol may be synthetic or commercially available.

In one embodiment of the present invention, examples of the method for producing a mixture of secondary alcohols represented by the above formula (A) include JP-A-48-34807, JP-A-56-131531, and JP-A-48. A known method such as 377242 can be applied in the same manner or appropriately modified. For example, in the secondary alcohol, a saturated aliphatic hydrocarbon is liquid-phase oxidized with a molecular oxygen-containing gas in the presence of metaboric acid to obtain a reaction solution containing an oxide (oxidation reaction step); the oxide. Is esterified to obtain a reaction solution containing a borate compound (esteration step); the reaction solution containing the borate compound is distilled and separated into unreacted saturated aliphatic hydrocarbons and distillation residue (unreacted saturated). Adipose hydrocarbon recovery step); The distillation residue is hydrolyzed to separate orthoboric acid and an organic layer (hydrolysis step); the organic layer is saponified with an alkali to form an alkaline aqueous solution layer and a crude alcohol layer. Separation (saponification step); can be obtained by further purifying the crude alcohol layer (purification step).

In one embodiment of the present invention, as the step (i-1) (first alkoxylation reaction), for example, JP-A-2003-221593, JP-A-48-34807, JP-A-56-131531 Gazette, Oil Chemistry, 24, 7, p. p. Known methods such as 427-434 (1975) and Japanese Patent Publication No. 51-046084 can be applied in the same manner or appropriately modified. The following is an example of the alkylene oxide addition reaction. The present invention is not limited to the following method.

As the catalyst, an acid catalyst is used from the viewpoint that the number of moles of alkylene oxide added can be controlled to a desired degree (low). That is, in the preferred embodiment of the present invention, the catalyst is an acid catalyst. Examples of the acid catalyst include boron trifluoride, boron trifluoride-complex (ether complex (etherate), phenol complex (phenolate), acetate complex, etc.), antimony pentachloride, tin tetrachloride, tris (pentafluorophenyl) borane, and the like. Phosphoric acid, sulfuric acid and the like can be mentioned, but the present invention is not limited thereto. The amount of the catalyst added is, but is not limited to, 0.05 to 0.5% by mass, preferably more than 0.05% by mass and less than 0.3% by mass with respect to the secondary alcohol.

As the alkylene oxide (AO), ethylene oxide, propylene oxide and the like are suitable. In one embodiment of the present invention, nitrogen may be substituted when adding the alkylene oxide. The initial nitrogen pressure at the time of nitrogen substitution is preferably 0.05 to 1.0 MPa, more preferably 0.05 to 0.4 MPa.

The amount of alkylene oxide supplied can be appropriately adjusted according to the desired average number of moles of alkylene oxide added to the secondary alcohol. For example, the amount of alkylene oxide added is 1.0 mol or more and less than 1.8 mol, preferably more than 1.0 mol, with respect to 1 mol of the secondary alcohol (one hydroxyl group of the secondary alcohol). It is 7 mol or less, more preferably 1.1 to 1.5 mol, particularly preferably 1.1 to 1.4 mol, and the like, but the present invention is not limited thereto. When the alkylene oxide is added in a divided manner, the amount of the alkylene oxide added is the total amount of the alkylene oxide added.

The reaction of the secondary alcohol with the alkylene oxide is such that the secondary alcohol and the catalyst are supplied to the reactor and then the alkylene oxide is supplied to the reactor; the secondary alcohol is supplied to the reactor and then the catalyst and the catalyst are supplied. The alkylene oxide may be supplied to the reactor in any order or simultaneously; the secondary alcohol, the alkylene oxide and the catalyst may be supplied to the reactor in any form. Preferably, the secondary alcohol and the catalyst are supplied to the reactor, and then the alkylene oxide is supplied. Further, the secondary alcohol, the catalyst and the alkylene oxide may be supplied in a batch, continuously, or in stages (divided), respectively. Preferably, the secondary alcohol and the catalyst are collectively supplied to the reactor, and the alkylene oxide is supplied to the reactor in stages (divided). Thereby, the number of moles of alkylene oxide added (m in the following formula (C)) can be easily controlled within a desired range.

The reactor used for the reaction between the secondary alcohol and the alkylene oxide may be a tank reactor (batch reactor), a tube reactor (continuous reactor), or a continuous tank reactor. .. Further, the above reactors may be combined as appropriate.

The reactor is not particularly limited, and can be appropriately selected depending on the supply amount of each raw material (secondary alcohol, alkylene oxide, catalyst) and the like. From the viewpoint that the alkylene oxide can be easily divided and supplied to the reactor, it is preferable to use at least a tubular reactor (continuous reactor). That is, in a preferred embodiment of the present invention, the reaction between the secondary alcohol and the alkylene oxide is carried out in a tubular reactor (continuous reactor), and the alkylene oxide is applied at at least one place other than the inlet of the tubular reactor. Add (ie, split and supply the alkylene oxide). Thereby, the number of moles of alkylene oxide added (m in the following formula (C)) can be controlled more easily. Further, with this configuration, it is possible to suppress the temperature change in the reactor and suppress / prevent the local temperature rise due to the ethylene oxide addition reaction. In addition, a thermometer is installed in the reactor. Thereby, the temperature during the reaction can be easily controlled.

Alternatively, in another preferred embodiment of the present invention, the reaction of the secondary alcohol with the alkylene oxide is carried out in a tank reactor (batch reactor). In addition, a thermometer is installed in the reactor. Thereby, the temperature during the reaction can be easily controlled.

Alternatively, in another preferred embodiment, a tubular reactor and a tank reactor are used in combination. Here, the installation order of the tubular reactor and the tank reactor is such that the tank reactor is installed downstream of the tubular reactor (the reactant of the tubular reactor is supplied to the tank reactor). Is preferable. With this configuration, the number of moles of alkylene oxide added (m in the following formula (C)) can be controlled more easily while suppressing / preventing the local temperature rise due to the alkylene oxide addition reaction more effectively.

The shape / size of the reactor is not particularly limited, and can be appropriately selected depending on the supply amount of each raw material (secondary alcohol, alkylene oxide, catalyst) and the like. For example, in a tubular reactor, the reactor (reaction tube) may be linear or have a partially bent portion (for example, J-shaped, U-shaped, Z-shaped, etc.). It may be circular. The tubular reactor (reaction tube) preferably has at least a partially bent portion, and more preferably has a structure in which U-shaped reaction tubes are repeatedly connected. Further, the alkylene oxide may be supplied to a plurality of locations of the reactor, and preferably the alkylene oxide is supplied to a plurality of locations of the tubular reactor. When a plurality of alkylene oxide supply units are installed in a reactor (particularly a tubular reactor), the amount of alkylene oxide supplied in each supply unit is preferably an amount or a reaction temperature so that the reaction temperature does not rise locally. The amount is preferably controlled by a range. Alternatively, the supply location of the alkylene oxide is preferably, but is not limited to, a location where the alkylene oxide supplied in the previous stage (upstream) reacts and the concentration of the alkylene oxide is lowered. By supplying the above-mentioned alkylene oxide in a divided manner and controlling the reaction temperature within an appropriate range (particularly 70 ° C. or lower), the reduction in hue can be effectively suppressed. In addition, although the tube-type reactor may be equipped with a thermometer at only one place, it is preferable that a plurality of thermometers are installed in the reactor in order to capture the peak temperature in the reactor. With this configuration, temperature changes during the reaction can be confirmed evenly. Here, the number of thermometers installed is preferably 5 or more and 50 or less per 100 m of tubular reactor length, and it is preferable that the peak temperature in the reactor can be captured by the number of locations where alkylene oxide is supplied to the reactor. It is preferably 7 or more and 15 or less, but is not limited thereto. The interval between the installation of the thermometer is immediately after the place where the alkylene oxide is supplied to the reactor (for example, 0 m or more and less than 100 m from the place where the alkylene oxide is supplied, preferably 0 to 80 m, more preferably the total number of thermometers installed. It is preferable to install it in a place where the temperature rises due to the reaction at a rate of more than 80% (0 to 50 m) and the peak temperature can be captured, and it is preferably 1 m or more and 50 m or less, preferably 5 m or more and 10 m or less, but is not limited thereto. .. By installing the thermometer as described above, the reaction temperature can be controlled within an appropriate range (particularly 70 ° C. or lower), and the reduction of hue can be effectively suppressed.

As the reaction conditions (alkoxylation reaction conditions) between the secondary alcohol and the alkylene oxide, the same conditions as those known can be adopted. For example, the reaction temperature is 30 ° C. or higher and 70 ° C. or lower, preferably 45 ° C. or higher and 70 ° C. or lower, but is not limited thereto. In order to adjust to the reaction temperature, the reactor may have a system for flowing a heat medium (eg, hot water). When using a tubular reactor, it is preferable to monitor all the thermometers installed to confirm that the reaction temperature of the tubular reactor does not exceed the peak temperature. The reaction time is 30 minutes or more and 150 minutes or less, preferably 50 minutes or more and 120 minutes or less, but is not limited thereto. Under such conditions, the alkylene oxide adduct molars of the alkylene oxide adduct can be easily controlled in a desired range. In addition, by-production of color-inducing substances can be effectively suppressed / prevented. The reaction time is the total reaction time when two or more reactors are used. Alternatively, the number of alkylene oxide adducts added during the reaction may be measured, and the reaction may be terminated when a desired value is reached. The reaction pressure may be either normal pressure or pressurized, but from the viewpoint of solubility of alkylene oxide, reaction rate and the like, it is preferable to carry out the reaction under pressure with an inert gas such as nitrogen gas.

By the above reaction, an alkylene oxide adduct (alkylene oxide adduct A) (a reaction solution containing an alkylene oxide adduct (alkylene oxide adduct A)) is obtained.

(Step (i-2))
In this step, the alkylene oxide adduct (alkylene oxide adduct A) obtained in the above step (i-1) (reaction solution containing the alkylene oxide adduct (alkylene oxide adduct A); the same applies hereinafter) is mixed with water. It is mixed and separated into an aqueous layer and an organic layer (cleaning step: “reaction solution cleaning” in FIG. 1). This separates the organic layer containing the alkylene oxide adduct. The alkylene oxide addition reaction does not substantially proceed depending on the washing step of this step (i-2) (the number of alkylene oxide adducts (average number of moles added) of the alkylene oxide adduct of the alkylene oxide adduct is substantially the same. Does not change to).

The alkylene oxide adduct may be mixed with water alone or with a solution containing water (hereinafter, also referred to as "washing water"). Here, when washing water is used, the washing water contains, for example, bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, magnesium hydroxide and the like, in addition to water. Not limited to these. Preferably, the washing water is a mixed solution (alkaline aqueous solution) of water and a base (particularly sodium hydroxide and potassium hydroxide). The content of the components such as the base in the washing water is, for example, an amount such that the concentration is 0.1 to 30% by mass, preferably 0.5 to 5% by mass, but is not limited thereto. As a result, the catalyst (particularly the acid catalyst) can be efficiently removed. Further, the step of mixing the alkylene oxide adduct with water or washing water may be performed once or repeated twice or more. In the latter case, the alkylene oxide adduct is mixed with wash water, separated into an aqueous layer and an organic layer (organic layer 1), and then the organic layer 1 is mixed with water alone, and the aqueous layer and the organic layer are mixed. It is preferable to separate it into (organic layer 2). That is, in a preferred embodiment of the present invention, in the separation, the reaction solution containing the alkylene oxide adduct is mixed with an alkaline aqueous solution to separate into an aqueous layer and an organic layer 1, and then the organic layer 1 is mixed with water to form water. This is done by separating into a layer and an organic layer 2. Thereby, the color-inducing substance can be removed more efficiently.

The mixing ratio of the alkylene oxide adduct to water or washing water (particularly the alkaline aqueous solution) (reaction solution containing the alkylene oxide adduct: water or washing water (mixed volume ratio)) is preferably 1 to 8: 1, more preferably. Is 3 to 5: 1, but is not limited to these. That is, in a preferred embodiment of the present invention, when the reaction solution containing the alkylene oxide adduct is mixed with the alkaline aqueous solution, the mixed volume ratio of the reaction solution and the alkaline aqueous solution is 1 to 8: 1. Further, in a preferred embodiment of the present invention, when the organic layer 1 is mixed with water, the mixed volume ratio of the organic layer 1 and water is 1 to 8: 1. In a more preferable embodiment of the present invention, when the reaction solution containing the alkylene oxide adduct is mixed with the alkaline aqueous solution, the mixed volume ratio of the reaction solution and the alkaline aqueous solution is 3 to 5: 1. Further, in a more preferable embodiment of the present invention, when the organic layer 1 is mixed with water, the mixed volume ratio of the organic layer 1 and water is 3 to 5: 1. By keeping the amount of water or washing water below the same amount (particularly smaller) as the liquid containing the alkylene oxide adduct (reaction liquid or organic layer 1) as described above, the reaction liquid is made water while ensuring the washing efficiency. Alternatively, the emulsified state (particularly the water-in-oil type) (and therefore coloring) when mixed with the washing water can be more effectively suppressed / prevented.

Alternatively, the alkylene oxide adduct is mixed with an alkaline aqueous solution (washing water), separated into an aqueous layer and an organic layer (organic layer 1), and if necessary, then the organic layer 1 is mixed with water alone to form an aqueous layer. And an organic layer (organic layer 2) may be separated.

The method for mixing the alkylene oxide adduct with water or washing water is not particularly limited, and a known method can be used. For example, water or washing water is added to the alkylene oxide adduct, and the mixture is sufficiently stirred and mixed to dissolve the alkylene oxide adduct in the organic layer and then allowed to stand. When the aqueous layer and the organic layer are separated, the organic layer is taken out. The method etc. can be mentioned. Here, the stirring / mixing conditions are not particularly limited. For example, the stirring / mixing temperature is 40 to 100 ° C., preferably 80 ° C. or higher and lower than 100 ° C. The stirring / mixing time is 5 to 120 minutes, preferably 10 minutes or more and less than 30 minutes. When the alkylene oxide adduct is washed with water and washing water (washing with water and then washing with washing water, or washing with washing water and then washing with water), even if the stirring and mixing conditions in each washing step are the same. Or it may be different.

After mixing the reaction solution with water or wash water, it is allowed to stand to separate into an aqueous layer and an organic layer. Here, the standing condition is also not particularly limited, but the standing temperature preferably exceeds 60 ° C. By setting the standing temperature to more than 60 ° C., it is possible to suppress the formation of an emulsified layer between the aqueous layer and the organic layer, and the aqueous layer can be separated well. As a result, the color-inducing substance contained in the aqueous layer can be removed more efficiently, and the hue of the final product (secondary alcohol alkoxylate) can be improved. The standing temperature is preferably more than 60 ° C. and less than 100 ° C., more preferably more than 60 ° C. and 95 ° C. or less, and particularly preferably more than 65 ° C. and less than 85 ° C. The standing time is, for example, 5 to 120 minutes, preferably 30 to 60 minutes, but is not limited to the above. The apparatus used for mixing the alkylene oxide adduct with water or wash water is not particularly limited, but after stirring and mixing the alkylene oxide adduct with water or the mixing solution (wash water) in the mixer portion (mixing tank). , A mixer-settler type device that can separate the aqueous layer and the organic layer in the settler part (stationary tank) can be used. Alternatively, a device such as a line mixer or a countercurrent scrubber may be used.

This step separates the organic layer containing the alkylene oxide adduct. In particular, the alkylene oxide adduct is mixed with wash water and separated into an aqueous layer and an organic layer (organic layer 1), and then the organic layer 1 is mixed with water alone to form an aqueous layer and an organic layer (organic layer 2). When separated into, an alkylene oxide adduct is obtained with high purity.

The organic layer obtained as described above may be dehydrated if necessary. Thereby, the number of moles of alkylene oxide added to the secondary alcohol alkoxylate precursor (m in the following formula (C)) can be more effectively controlled within a desired range. Here, the dehydration method is not particularly limited, and a known method can be applied in the same manner or appropriately modified. For example, it can be dehydrated by distilling or fractionating the organic layer. The dehydration pressure (pressure at the top of the column) at this time is, but is not limited to, 1 to 500 hPa, preferably 50 to 300 hPa or the like. In addition, in this specification, a pressure means the value of the pressure measured by the pressure gauge installed in the upper part of the reactor for measuring the pressure of a gas phase part. Unless otherwise specified, the same definitions apply herein. The dehydration temperature (bottom temperature) is, but is not limited to, 50 to 200 ° C., preferably 100 to 150 ° C. and the like. Under such conditions, unreacted alcohol and the like are efficiently removed, and the number of moles of alkylene oxide added to the secondary alcohol alkoxylate precursor (m in the following formula (C)) is further increased to a desired range. Can be effectively controlled.

The average number of moles of alkylene oxide added (k in the following formula (B)) of the alkylene oxide adduct (alkylene oxide adduct B) obtained in this step is more than 0 and less than 2.1, preferably 2. It is less than 0.0, more preferably less than 1.8, even more preferably 1.7 or less, and particularly preferably less than 1.7. The average number of moles of alkylene oxide added to the alkylene oxide adduct (alkylene oxide adduct) obtained in this step is more than 0, but the target product (particularly the secondary alcohol alkoxylate 3 mol adduct (alkylene oxide)). From the viewpoint of improving the yield of the adduct B)), it is preferably 1.2 or more, more preferably more than 1.5. With such an addition number of moles, the secondary alcohol alkoxylate can be produced more efficiently (more mass-produced) while further reducing the coloring of the final product, the secondary alcohol alkoxylate. That is, in a preferred embodiment of the present invention, the average number of moles of alkylene oxide added to the alkylene oxide adduct (alkylene oxide adduct A) obtained in this step is 1.2 or more and less than 2.0. In a more preferred embodiment of the present invention, the average number of moles of alkylene oxide added to the alkylene oxide adduct (alkylene oxide adduct A) obtained in this step is more than 1.5 and less than 1.8. In a more preferable embodiment of the present invention, the average number of moles of alkylene oxide added to the alkylene oxide adduct (alkylene oxide adduct A) obtained in this step is more than 1.5 and 1.7 or less. In a particularly preferred embodiment of the present invention, the average number of moles of alkylene oxide added to the alkylene oxide adduct (alkylene oxide adduct A) obtained in this step is more than 1.5 and less than 1.7. In the present specification, the average number of moles of alkylene oxide added is a value measured by the following method.

(Average number of moles of alkylene oxide adduct added)
The average number of moles of alkylene oxide added (average number of moles of AO added) of the alkylene oxide adduct is calculated from the analytical value of the hydroxyl value of the alkylene oxide adduct using the following formula 1. The hydroxyl value is measured based on the B method of JIS K1557-1: 2007. Specifically, the sample is a pyridine solution containing phthalic anhydride, and the hydroxyl groups are phthalated under reflux of pyridine. The excess phthalate reagent is hydrolyzed with water and the resulting phthalic acid is titrated with a standard solution of sodium hydroxide. The hydroxyl value is measured by calculating from the difference in titration between the blank test and the sample test.

(Step (i-3))
In this step, the organic layer separated in the above step (i-2) is purified (purification step: "light separation" and "rectification" in FIG. 1). As a result, a secondary alcohol alkoxylate precursor is obtained.

Here, the purification method is not particularly limited, and a known method can be applied in the same manner or appropriately modified. For example, it can be purified by distilling or fractionating the organic layer. The purification pressure (pressure at the top of the column) at this time is, but is not limited to, 1 to 100 hPa, preferably 3 to 50 hPa or the like. The purification temperature (bottom temperature) is, but is not limited to, 150 to 250 ° C., preferably 175 to 225 ° C. and the like. Under such conditions, it is desirable to efficiently remove light substances, unreacted alcohols, secondary alcohol alkoxylate fractions having a low number of moles of alkylene oxide (for example, less than 2.5 moles), and the like. The secondary alcohol alkoxylate precursor of the above can be appropriately separated. In FIG. 1, the purification step (distillation / fractional distillation step) is performed twice, but the purification step may be performed once or repeatedly. For example, as shown in FIG. 1, after removing the light substance by the light separation step (“light separation” in FIG. 1), unreacted alcohol or alkylene oxide is added by the rectification step (“rectification” in FIG. 1). The low AO molar addition fraction having a low molar number (for example, the number of moles of alkylene oxide added = less than 2.5) may be removed. As a result, a secondary alcohol alkoxylate precursor represented by the following formula (C) is obtained.

In the above formula (C), x and y have the same definitions as the above formula (A).

In the above formula (C), X represents an alkylene group having 1 to 3 carbon atoms. Here, the alkylene groups having 1 to 3 carbon atoms are a methylene group (−CH ₂ −), an ethylene group (−CH ₂ CH ₂ −), a trimethylene group (−CH ₂ CH ₂ CH ₂ −), and a propylene group (−CH 2 CH 2 CH 2 −). CH (CH ₃ ) CH _2- , −CH ₂ CH (CH ₃ ) −). Preferably, X is an ethylene group. m is the average number of moles of alkylene oxide added to the secondary alcohol alkoxylate precursor. m is preferably 2.5 or more and 3.5 or less, more preferably more than 2.7 and less than 3.1, but is not limited thereto. In the present specification, the average number of moles of alkylene oxide added to the secondary alcohol alkoxylate precursor is the same as that of "alkylene oxide adduct" in the above (average number of moles of alkylene oxide adduct). It should be read as "classic alcohol alkoxylate precursor" and the value measured in the same manner is adopted.

That is, in a preferred embodiment of the present invention, the secondary alcohol alkoxylate precursor is represented by the following formula (C):

In the above formula (C), X represents an alkylene group having 1 to 3 carbon atoms; the total (x + y) of x and y is an integer of 8 to 12; m is 2.5 or more and 3.5 or less. be,
In the presence of a catalyst, a secondary alcohol is reacted with an alkylene oxide to obtain a reaction solution containing an alkylene oxide adduct A, the reaction solution is mixed with water, and then allowed to stand at a temperature exceeding 60 ° C. Then, it is separated into an aqueous layer and an organic layer, and the following formula (B):

In the above formula (B), X and x and y have the same definition as the above formula (C); k is 5 or more and 50 or less.
It is obtained by obtaining a liquid containing the alkylene oxide adduct B represented by the above and purifying the liquid. Further, in the above preferable form, in the formula (B), k is preferably more than 1.5 and less than 1.8. In the above preferred embodiment, the separation is performed by mixing the reaction solution with an alkaline aqueous solution and separating it into an aqueous layer and an organic layer 1, and then mixing the organic layer 1 with water and separating the reaction solution into an aqueous layer and an organic layer 2. It is preferably done by. In the above embodiment, when the reaction solution is mixed with the alkaline aqueous solution, the mixed volume ratio of the reaction solution and the alkaline aqueous solution is preferably 1 to 8: 1. In the above embodiment, when the organic layer 1 is mixed with the water, the mixed volume ratio of the organic layer 1 and the water is preferably 1 to 8: 1.

The secondary alcohol alkoxylate precursor as described above exhibits a good hue with reduced coloring. Specifically, the hue (APHA) of the secondary alcohol alkoxylate precursor is less than 45, preferably 40 or less, and more preferably 30 or less. Here, the lower limit of the hue (APHA) of the secondary alcohol alkoxylate precursor is not particularly limited, but 20 or more is sufficient. That is, the hue (APHA) of the secondary alcohol alkoxylate precursor is preferably 20 to 40, more preferably 20 to 30. In the present specification, the hue (APHA) of the secondary alcohol alkoxylate precursor adopts the value measured by the method described in the following Examples.

(Step (ii))
In this step, an alkylene oxide is added to the secondary alcohol alkoxylate precursor produced in the above step (i) in a tubular reactor (second alkoxylation reaction step: “second alkoxylation” in FIG. reaction"). Here, the tubular reactor has an alkylene oxide supply unit at n locations other than the inlet and the inlet (n is an integer of 2 or more), and the alkylene oxide is transferred through the alkylene oxide supply unit. It is added (divided and supplied) to the secondary alcohol alkoxylate precursor to react the secondary alcohol alkoxylate precursor with the alkylene oxide in the tubular reactor. In the present specification, the alkylene oxide supply unit is intended as a supply unit to which the alkylene oxide is actually supplied. Therefore, even if the alkylene oxide supply unit is installed in a tubular reactor for supplying the alkylene oxide, the alkylene oxide supply unit that does not actually supply the alkylene oxide is referred to as the "alkylene oxide supply unit" according to the present invention. Do not consider.

In the tubular reactor, the alkylene oxide supply unit (including the reactor inlet) is installed in the tubular reactor so as to satisfy the following formula (1). That is, when the secondary alcohol is reacted with the alkylene oxide, the alkylene oxide supply set is installed at a ratio of more than 40%.

In the above formula (1), N [X _n' , X _{n'+ 1} ] represents the number of adjacent three alkylene oxide supply unit sets satisfying _{X n'} <X _{n'+ 1].} At this time, X n _', the tubular reactor n from the inlet side of the'_'and, from the inlet side of the tube reactor n' alkylene oxide feed unit P _n installed in th alkylene oxide installed + 1st Indicates the interval (m) between the supply unit P _{n'+ 1 and.} n'is an integer greater than or equal to 0 and less than or equal to n-2. Further, X _{n'+ 1} is the distance (m) between the alkylene oxide supply unit P _{n'+ 1 and the alkylene oxide supply unit P n'+ 2} installed n'+ second from the inlet side of the tubular reactor. Represent. That is, N [X _n' , X _{n'+ 1 ] is three adjacent alkylene oxide supply units (P n'} , P _{n'+ 1} and P _{n'from the} inlet side of the tubular reactor, as shown below. _{When +2} ) is set as one set, it is closer to the outlet (downstream of the reaction) than the distance ( _{Xn' ) between two adjacent alkylene oxide supply parts (P n'and} P _{n'+1) on the inlet (upstream of the reaction).} The distance (X _{n'+ 1} ) between two adjacent alkylene oxide supply units (P _{n'+ 1} and P _{n'+ 2} ) is larger (X _n' <X _{n'+ 1} ) means the number of alkylene oxide supply unit sets. do.

That is, the above formula (1) is based on the number of alkylene oxide supply unit sets (N [X _n' , X _{n' ) that satisfy X n'} <X _{n'+ 1} with respect to the total number of alkylene oxide supply unit sets (n-1). ₊₁ ])) (N [X _n' , X _n'+1 ] / (n-1)) means that it exceeds 40% (4/10). In the present specification, "N [X _n' , X _{n'+ 1} ] / (n-1)" is the number of alkylene oxide supply unit sets satisfying _{X n'} <X _{n'+ 1 (N [X n'} , X). _{The value obtained by dividing n'+ 1} ]) by the total number of sets of alkylene oxide supply units (n-1) is obtained to the second decimal place, and the value obtained by rounding to the first decimal place is adopted.

As used herein, the reaction tube is intended to be a portion of a tubular reactor in which the addition reaction of an alkylene oxide to a secondary alcohol alkoxylate precursor substantially proceeds. Therefore, for example, in FIG. 2, the reaction tube portion between the tubular _{reactor inlet (P 0 in} FIG. 2) and the tubular reactor outlet (P _{outlet in FIG. 2) is the present embodiment.} It is a reaction tube according to.

In the present specification, the alkylene oxide supply unit (P _0' ) in which n'is 0 is a tubular reactor inlet (“P ₀ ” in FIG. 2) which is the alkylene oxide supply unit first installed in the reaction tube. ).

In the present specification, the distance (X _n' ) between two adjacent alkylene oxide supply units (P _n'and P _{n'+ 1} ) is the alkylene oxide supply unit to which the alkylene oxide is supplied, as shown in FIG. (P n _') center of the reaction tube at the (in FIG. 3, "P _n'") and the alkylene oxide feed section (P n _') the supply of alkylene oxide portion adjacent the reaction downstream of the (P _{n' + 1)} The distance from the center of the reaction tube (“P _{n'+ 1} ” in FIG. 3) (the length of the solid line portion in FIG. 3 “X _n' ”). At this time, the center of the reaction tube is a point corresponding to the center of gravity of the cut surface obtained by cutting the tube at a surface perpendicular to the longitudinal direction of the reaction tube. For example, when the cross section of the reaction tube is circular, it is the center of the circle, and when it is not circular, it is the center of the largest circle that can be drawn inside the cross section of the reaction tube. For example, the supply of alkylene oxide unit (P 0 _') with the P _0' the supply of alkylene oxide portion adjacent to (P 1 _') spacing between (X _1') is first reaction tube inlet alkylene oxide is supplied ( The center of the reaction tube at the center of the tube plate surface corresponding to the boundary between the tube plate surface and the reaction tube; see FIG. 2), and the center of the reaction tube at the alkylene oxide supply section where the alkylene oxide is supplied next. Is the distance between.

Here, when N [X _n' , X _{n'+ 1} ] / (n-1) in the formula (1) is 0.4 or less, the alkylene oxide is supplied too frequently and the alkylene oxide is secondary. It is locally added to the alcohol alkoxylate precursor, resulting in coloring of the final product, the secondary alcohol alkoxylate (Comparative Examples 1, 3 and 4). From the viewpoint of further reducing the coloring of the secondary alcohol alkoxylate, which is the final product, N [X _n' , X _{n'+ 1} ] / (n-1) in the formula (1) is 0.5 or more. It is preferably present, more preferably more than 0.7, and particularly preferably 0.8 or more. According to this embodiment, the local addition reaction of alkylene oxide to the secondary alcohol alkoxylate precursor is suppressed, the alkylene oxide addition reaction is appropriately controlled, and the final product, the secondary alcohol alkoxylate, is colored. Can be reduced more effectively. _{Since it is preferable that X n'} <X _{n'+ 1} is satisfied in all the alkylene oxide supply unit sets, the upper limit of N [X _n' , X _{n'+ 1} ] / (n-1) in the formula (1) is It is preferably 1, but may be less than 0.95 or 0.9 or less, for example. That is, in a preferred embodiment of the present invention, the alkylene oxide supply unit is installed in the tubular reactor so as to satisfy the following formula (1'):

In the above formula (1'), N [X _n' , X _{n'+ 1} ] has the same definition as the above formula (1).

In the above formula (1), the alkylene oxide is supplied at a ratio of more than 40% so that the supply interval is long, but preferably at a ratio of more than 80%, more preferably in all the alkylene oxide supply unit sets. supply interval is equal to or more _{(X n '≦ X n'} + 1). With this configuration, the coloring of the final product, the secondary alcohol alkoxylate, can be reduced more effectively.

When X _{n'+ 1} is larger than _{X n' (satisfies X n'} <X _{n'+1 ), the alkylene oxide supply unit P n'+ 1} installed at the n'+ 1th position from the inlet side of the tubular reactor, and The n'th from the inlet side of the tubular reactor with respect to the distance [X _{n'+ 1 (m)] between the alkylene oxide supply unit P n'+ 2} installed n'+ second from the inlet side of the tubular reactor. in _'and, from the inlet side of the tube reactor n' alkylene oxide feed unit P _n installed alkylene oxide feed unit P _n is placed + 1st _'+1, interval [X n _of' (m)] of the The ratio [X _{n'+ 1} / X _n' ] is greater than 1. From the viewpoint of further reducing the effect of the coloration of the secondary alcohol alkoxylate which is the final product, the ratio of _{'X n} for the _{+ 1' X n [X n} '+ 1 / X n'] is preferably greater than 1.05 , More preferably 1.10 or more, but not limited to this. The ratio of _{'X n} for the _{+ 1'} X _n when the _{[X n '+ 1 / X} n'] is, for example, 1.50 or less, preferably less than 1.30, but not limited to ..

The alkylene oxide supply interval (distance between adjacent alkylene oxide supply portions, "X _n' " in FIG. 3) is, for example, 10 m or more and 200 m or less, preferably 20 m or more and 150 m or less, and more preferably 30 m or more and 100 m. Less than, but not limited to. The local addition reaction of alkylene oxide to the secondary alcohol alkoxylate precursor can be more effectively suppressed or prevented. Therefore, the hue of the final product, the secondary alcohol alkoxylate, can be improved.

The number of alkylene oxide supply portions of the tubular reactor is installed so as to decrease in the downstream direction of the tubular reactor. Preferably, the alkylene oxide supply is between the inlet of the tubular reactor and half of the total tube length with respect to the number of alkylene oxide supply units installed (N _{outlet) beyond half of the total tube length of the tubular reactor to the outlet.} The ratio (N _inlet / N _outlet ) of the number of installed parts (N _inlet ) is more than 1.0 / 1 and 10.0 / 1 or less, preferably 1.5 / 1 or more and less than 5.0 / 1. As used herein, the term "N _inlet " refers to the region of the total pipe length from the inlet to the outlet of a tubular reactor, from the inlet to half of the total pipe length (including the reactor inlet and half of the total pipe length) ("tube type". This is the number of alkylene oxide supply units installed in the "reactor upstream region"). Therefore, when the alkylene oxide supply unit is installed at the _inlet of the tubular reactor, the “N inlet” includes the number of ethylene oxide supply units installed at the inlet of the tubular reactor. Further, the "N _outlet " is a region from the inlet to the outlet of the tubular reactor, which exceeds half of the total tubular length of the tubular reactor and reaches the outlet (also referred to as "downstream region of the tubular reactor"). It is the number of installations of the alkylene oxide supply part in. For "N _inlet / N _outlet ", the value obtained by dividing the above "N _inlet " by the above "N _outlet " is obtained to the second decimal place, and the value obtained by rounding to the first decimal place is adopted. For example, in Example 1 below, a total of 10 ethylene oxide supply units including the inlet of the second reactor are installed in the second reactor, and the region from the inlet of the second reactor to half of the total pipe length (tube type reaction). The number of alkylene oxide supply units installed in the upstream area of the reactor is 8 (N _inlet = 8), and the area beyond half of the total length of the tubular reactor of the second reactor to the outlet (downstream of the tubular reactor). Since the number of alkylene oxide supply units installed in the region) is 2 (N _outlet = 2), the N _inlet / N _outlet is 4.0 (= 8/2).

In addition to the above, in a tubular reactor, an alkylene oxide is added to the secondary alcohol alkoxylate precursor so as to satisfy the following formula (2). That is, when the secondary alcohol alkoxylate precursor is reacted with the alkylene oxide, the alkylene oxide is supplied at a ratio of 30% or more so that the supply amount is large.

In the above equation (2), N [Y _{n "} , Y _{n" + 1} ] represents the number of two adjacent alkylene oxide supply sets satisfying _{Y n "} <Y _{n" + 1.} At this time, Y _{n "} represents the supply amount (kg / hr) of the alkylene oxide in the _{alkylene oxide supply unit P n"} installed at the n "th position from the inlet side of the tubular reactor. N" is 0 or more n. It is an integer less than or equal to -1. Further, Y _{n "+ 1} represents the supply amount (kg / hr) of the alkylene oxide _{in the alkylene oxide supply unit P n" + 1} installed n "+ 1st from the inlet side of the tubular reactor, that is, N [. Y _{n "} , Y _{n" + 1} ] is the alkylene oxide supply unit on the inlet (reaction upstream) side when _{two adjacent alkylene oxide supply units (P n "} and P _{n" + 1 from the inlet side) are set as one set. "alkylene} oxide feed amount at _{(Y n (P n)"} from), the outlet of the _"alkylene oxide feed amount of _{(+1 (Y n (reaction} downstream) side of the adjacent alkylene oxide feed unit _{P n)" +1)} The larger (Y _{n "} <Y _{n" + 1} ) means the number of alkylene oxide supply unit sets.

That is, the above formula (2) is based on the number of alkylene oxide supply unit sets _{satisfying Y n "} <Y _{n" + 1} (N [Y _{n "} , Y _{n" + 1} ]) with respect to the total number of alkylene oxide supply unit sets (n). Means that it is 30% (3/10) or more. In the present specification, "N [Y _n" , Y _{n "+ 1} ] / n" is the number of alkylene oxide supply unit sets satisfying _{Y n "} <Y _{n" + 1 (N [Y n "} , Y _{n" + 1} ]. ) Is divided by the number of sets of all alkylene oxide supply units (n) to the second decimal place, and the value obtained by rounding to the first decimal place is adopted.

In the present specification, the alkylene oxide supply unit (P _{0 "} ) in which n" is 0 is a tubular reactor inlet (“P ₀ ” in FIG. 2) which is the alkylene oxide supply unit first installed in the reaction tube. ).

Here, when N [Y _{n "} , Y _{n" + 1} ] / (n-1) in the formula (2) is less than 0.3, the alkylene oxide addition reaction is appropriately controlled by the temperature rise in the reactor. As a result, the secondary alcohol alkoxylate, which is the final product, is colored (Comparative Examples 1, 2, 3, 5). From the viewpoint of further reducing the coloring of the secondary alcohol alkoxylate, which is the final product, N [Y _{n "} , Y _{n" + 1} ] / (n-1) in the formula (2) is 0.6 or more. It is preferably more than 0.7, more preferably 0.9 or more, and particularly preferably 0.9 or more. The upper limit of N [Y _{n "} , Y _{n" + 1} ] / (n-1) in the formula (2) is preferably 1, but even if it is less than 0.97 or 0.95 or less, for example. good.

In the above formula (2), the alkylene oxide is supplied so that the supply amount of the alkylene oxide is increased at a ratio of 30% or more, preferably at a ratio of more than 80%, more preferably at a ratio of 90% or more. In the oxide supply unit set, the supply amount of alkylene oxide is equal to or higher than or equal to (Y _{n "} ≤ Y _{n" + 1} ). With this configuration, the coloring of the final product, the secondary alcohol alkoxylate, can be reduced more effectively.

When Y _{n "+1} is larger than _{Y n" (Y n "} <Y _{n" + 1} ), the amount of alkylene oxide supplied (Y _{n "} ) at _{the alkylene oxide supply unit (P n"} ) on the inlet (upstream of the reaction) side , Difference (Y _{n "+ 1-} Y _n" (kg / hr) from the alkylene oxide supply amount (Y _{n "+1 ) at the adjacent alkylene oxide supply unit (P n" + 1} ) on the outlet (downstream of the reaction) side. ) Is more than 0 (kg / hr). From the viewpoint of further reducing the effect of the coloration of the secondary alcohol alkoxylate which is the final _product, when _{Y n "+1} is _{Y n"} is greater than _{(Y n "<Y n"} +1), and _{Y n ",} Y The difference between _{n "+ 1 and (Y n" + 1-} Y _{n "} (kg / hr)) is preferably 0.5 (kg / hr) or more and 60 (kg / hr) or less, more preferably 1 (kg / hr). hr) or more and less than 40 (kg / hr), but is not limited thereto.

The second alkoxylation reaction is carried out in a tubular reactor under the conditions described above by adding an alkylene oxide at the inlet of the tubular reactor and at least one place other than the inlet to obtain a secondary alcohol alkoxylate. The precursor is continuously reacted with the alkylene oxide. With this configuration, it is possible to suppress a local temperature change in the reactor (particularly, suppress / prevent a local temperature rise due to the alkylene oxide addition reaction). Therefore, the coloring of the final product, the secondary alcohol alkoxylate, can be effectively reduced. It is also possible to easily control the number of moles of alkylene oxide added to the final product, the secondary alcohol alkoxylate. The reaction between the secondary alcohol alkoxylate precursor and the alkylene oxide may be carried out in a tubular reactor (continuous reactor), and the tank reactor (batch reactor) is used before and after the tubular reactor. , A tubular reactor (continuous reactor) and a continuous tank reactor may be provided separately.

In one embodiment of the present invention, examples of the alkylene oxide addition reaction include JP-A-2003-221593, JP-A-48-34807, JP-A-56-131531, Oil Chemistry, 24,7, p. .. p. Known methods such as 427-434 (1975) and Japanese Patent Publication No. 51-046084 can be applied in the same manner or appropriately modified. The following is an example of the alkylene oxide addition reaction. The present invention is not limited to the following method.

As the catalyst, an alkaline catalyst is used from the viewpoint that a secondary alcohol alkoxylate having a desired number of alkylene oxide addition moles can be produced (the number of alkylene oxide addition moles can be controlled to be high). That is, in the preferred embodiment of the present invention, the catalyst is an alkaline catalyst. Examples of the alkaline catalyst include, but are not limited to, sodium hydroxide, potassium hydroxide, sodium alkoxide and the like. The amount of the catalyst added is 0.01 to 1% by mass, preferably more than 0.02% by mass and less than 0.5% by mass, based on the secondary alcohol alkoxylate precursor, but is not limited thereto. .. Alternatively, the amount of the catalyst supplied to the tubular reactor is 0.1 to 5 kg / hr, preferably 0.5 to 2 kg / hr, but is not limited thereto.
In this step, the catalyst may be added in the form as it is or in the form of a solution (for example, an aqueous solution). The concentration of the catalyst in the latter case is, but is not limited to, about 30 to 70% by mass in the catalyst solution.

As the alkylene oxide (AO), ethylene oxide, propylene oxide and the like are suitable. In one embodiment of the present invention, nitrogen may be substituted when adding the alkylene oxide. The initial nitrogen pressure at the time of nitrogen substitution is preferably 1.0 to 2.0 MPa, more preferably 1.3 to 1.7 MPa.

The amount of alkylene oxide supplied to the tubular reactor is, but is not limited to, 300 to 1500 kg / hr, preferably 700 to 1200 kg / hr. Alternatively, the amount of alkylene oxide supplied to the tubular reactor is such that the average number of moles of alkylene oxide added to the secondary alcohol (the average number of moles of alkylene oxide added to the final product, the secondary alcohol alkoxylate) is 5. It may be adjusted to be ~ 50 mol (preferably 6-15 mol, more preferably 7-9 mol). For example, the amount of alkylene oxide added is, but is not limited to, 5 to 15 mol, preferably 6 to 12 mol, etc., with respect to 1 mol of the secondary alcohol alkoxylate precursor. The amount of alkylene oxide added is the total amount of alkylene oxide added in this step.

In the reaction between the secondary alcohol alkoxylate precursor and the alkylene oxide, the secondary alcohol alkoxylate precursor and the catalyst are supplied to the reactor, and then the alkylene oxide is separately supplied to the tubular reactor; the secondary alcohol. After feeding the alkoxylate precursor and the catalyst to the tubular reactor in any order (in the order of the secondary alcohol alkoxylate precursor-catalyst or the catalyst-post-secondary alcohol alkoxylate precursor) or at the same time, the alkylene The oxide is separately supplied to the reactor; the secondary alcohol alkoxylate precursor, the alkylene oxide and the catalyst are supplied to the tubular reactor, and then the alkylene oxide is supplied at at least one place other than the reactor inlet, and the like. It may be done in any format. Preferably, the secondary alcohol alkoxylate precursor, the alkylene oxide and the catalyst are supplied to the tubular reactor, and then the alkylene oxide is supplied at least one place other than the reactor inlet under the above-mentioned specific conditions. Thereby, it is possible to more effectively suppress the local temperature change in the reactor (in particular, to more effectively suppress / prevent the local temperature rise due to the alkylene oxide addition reaction). Therefore, the coloring of the final product, the secondary alcohol alkoxylate, can be reduced more effectively. In addition, the number of moles of alkylene oxide added to the final product, the secondary alcohol alkoxylate, can be controlled more easily. The secondary alcohol and catalyst may be supplied in bulk, continuously, or in stages (divided), respectively.

The shape and size of the tubular reactor are not particularly limited, and can be appropriately selected according to the supply amount of each raw material (secondary alcohol alkoxylate precursor, alkylene oxide, catalyst) and the like. For example, a tubular reactor (reaction tube) may be linear or partially bent (for example, J-shaped, U-shaped, Z-shaped, spiral-shaped, etc.) or circular. It may be. The tubular reactor (reaction tube) preferably has at least a partially bent portion, more preferably a U-shaped reaction tube, and particularly preferably a U-shaped reaction tube as shown in FIG. It has a structure in which reaction tubes are repeatedly connected. That is, in the preferred embodiment of the present invention, the tubular reactor has at least a partially bent portion. In a preferred embodiment of the invention, the tubular reactor has a U-shaped reaction tube. In a particularly preferred embodiment of the present invention, the tubular reactor has a structure in which U-shaped reactor tubes are repeatedly connected.

The inner diameter of the tubular reactor (reaction tube) is 15 mm or more and 65 mm or less, preferably 20 mm or more and 50 mm or less, but is not limited thereto. The outer diameter of the tubular reactor (reaction tube) is 10 mm or more and 70 mm or less, preferably 25 mm or more and 55 mm or less, but is not limited thereto. The length (tube length, total length) of the tubular reactor (reaction tube) can be appropriately selected according to the production amount of the secondary alcohol alkoxylate and the like. For example, the length (tube length) of the tubular reactor (reaction tube) is 100 m or more and 3000 m or less, preferably 300 m or more and 2000 m or less, but is not limited thereto. With a tubular reactor of such size, the hue of the final product, the secondary alcohol alkoxylate, can be improved more effectively.

In addition, the alkylene oxide is supplied at at least one place other than the inlet of the tubular reactor (it is continuously introduced through a supply portion installed along the longitudinal direction of the tubular reactor). Here, the number of alkylene oxides supplied is, for example, 2 or more and 30 or less, preferably 3 or more and 20 or less, and more preferably 5 or more and 18 or less, in addition to the inlet of the reactor, per 1000 m of tubular reactor length. , Not limited to these. That is, in one embodiment of the present invention, the alkylene oxide is added at 2 to 30 places per 1000 m of the tubular reactor. In a preferred embodiment of the present invention, alkylene oxides are added at 3 to 20 locations per 1000 m of tubular reactor. In a more preferred embodiment of the present invention, alkylene oxides are added at 5 to 18 locations per 1000 m of tubular reactor. Here, the alkylene oxide supply unit may be installed at any position of the tubular reactor, but as shown in FIG. 2, it is preferably installed on the same tubular surface of the tubular reactor. With this configuration, the supply amount of alkylene oxide can be controlled and coloring can be reduced.

Each alkylene oxide supply unit of the tubular reactor may be provided with a mechanism for smoothly supplying the alkylene oxide. As such a mechanism, for example, a weir is provided on the surface of the supply part, a mechanism for selectively flowing alkylene oxide from one reaction tube outlet to a desired reaction tube inlet is provided, and the opening of the reaction tube inlet and outlet is maintained. However, the present invention is not limited to these.

Each alkylene oxide supply portion of the tubular reactor may be supplied with alkylene oxide from one alkylene oxide source as shown in FIG. 2, or may be supplied with alkylene oxide from different (plural) alkylene oxide sources. You may.

Further, although the tube type reactor may have a thermometer installed at only one place, it is preferable that a plurality of thermometers are installed in the reactor. With this configuration, temperature changes during the reaction can be confirmed evenly. That is, in a preferred embodiment of the present invention, the temperature is measured at at least one place other than the inlet of the tubular reactor. Here, the number of installed thermometers is, for example, 5 or more and 50 or less, preferably 7 or more and 20 or less per 1000 m of tubular reactor length, but is not limited thereto. Further, the installation interval of the thermometer is immediately after the place where the alkylene oxide is supplied to the reactor (for example, 0 m or more and less than 100 m from the place where the alkylene oxide is supplied, preferably 0 to 80 m, and more preferably the total installation of the thermometer. It is preferable to install it in a place where the temperature rises due to the reaction at a rate of more than 80% of the number and the peak temperature can be captured, preferably 1 m or more and 50 m or less, preferably 5 m or more and 10 m or less. Not limited. By installing the thermometer as described above, the addition reaction of the alkylene oxide to the secondary alcohol alkoxylate precursor can be controlled more reliably. Therefore, the hue of the final product, the secondary alcohol alkoxylate, can be improved.

As the reaction conditions (alkoxylation reaction conditions) between the secondary alcohol alkoxylate precursor and the alkylene oxide, the same conditions as those known can be adopted. For example, the reaction temperature is 120 ° C. or higher and 180 ° C. or lower, preferably 130 ° C. or higher and 170 ° C. or lower, but is not limited thereto. Further, the maximum temperature during the reaction is preferably 170 ° C. or lower, more preferably less than 165 ° C. Thereby, the reduction of hue can be suppressed more effectively. As for the reaction temperature of the tubular reactor, it is preferable to monitor all the thermometers to be installed to confirm whether the peak temperature is exceeded.

Generally, the alkylene oxide addition reaction is an exothermic reaction. Therefore, in order to adjust to the reaction temperature, the reactor may have a system for circulating a heat medium (for example, hot water) as shown in FIG. When a system for flowing a heat medium is provided, the heat medium after circulation (for example, hot water or steam) may be taken out and used for other processes. This form leads to reuse of existing energy, reduction of carbon dioxide emissions, etc., and is preferable from the viewpoint of the global environment.

The reaction time is 0.1 hour or more and 2 hours or less, preferably 0.3 hours or more and 1 hour or less, but is not limited thereto. Under such conditions, a desired amount of alkylene oxide can be added to the secondary alcohol alkoxylate precursor. Moreover, the hue of the secondary alcohol alkoxylate, which is the final product, can be further improved. The reaction time is the total reaction time when two or more reactors are used. Alternatively, the alkylene oxide addition number of the secondary alcohol alkoxylate produced by the reaction may be measured, and the reaction may be terminated when the desired addition mole number is reached. The reaction pressure may be either normal pressure or pressurized, but from the viewpoint of solubility of alkylene oxide, reaction rate and the like, it is preferable to carry out the reaction under pressure with an inert gas such as nitrogen gas.

From the above, a secondary alcohol alkoxylate represented by the following formula (D) can be produced. Further, since the above method uses a tubular reactor, continuous (mass production) production is possible. Further, the secondary alcohol alkoxylate produced as described above has excellent hue and high purity. Therefore, according to the method according to the present disclosure, a secondary alcohol alkoxylate having an excellent hue can be continuously (in large quantities) produced.

In the above formula (D), x and y have the same definitions as the above formula (A). Further, in the above formula (D), X has the same definition as the above formula (B).

In the above formula (D), n is the average number of moles of alkylene oxide added to the secondary alcohol alkoxylate. n is 5 or more and 50 or less, preferably 6 or more and 15 or less, and more preferably 7 or more and 9 or less. Such a secondary alcohol alkoxylate has high water solubility and can be suitably used as a surfactant. In the present specification, the average number of moles of alkylene oxide added to the secondary alcohol alkoxylate is the same as the "alkylene adduct adduct" in the above (average number of moles of alkylene oxide adduct) as "secondary alcohol". Replace with "alkoxyrate" and adopt the value measured in the same way.

The secondary alcohol alkoxylate according to the present invention has an excellent hue (less or no coloring). Specifically, the hue (APHA) of the secondary alcohol alkoxylate is 70 or less. Here, the hue (APHA) of the secondary alcohol alkoxylate is preferably 65 or less, more preferably 60 or less. Here, the lower limit of the hue (APHA) of the secondary alcohol alkoxylate is preferably as low as possible, but is not particularly limited, but 50 or more may be sufficient, and 55 or more may be used. That is, the hue (APHA) of the secondary alcohol alkoxylate is preferably 50 to 70, more preferably 50 to 65, and even more preferably 50 to 60. In the present specification, the hue (APHA) of the secondary alcohol alkoxylate adopts a value measured by the method described in the following Examples.

As mentioned above, the secondary alcohol alkoxylate produced by the method of the present invention is less likely or less likely to be colored. In addition, the secondary alcohol alkoxylate produced by the method of the present invention does not gel or is difficult to gel, has excellent detergency, and has little or no odor. Therefore, the secondary alcohol alkoxylate and the secondary alcohol alkylene oxide high adduct are useful as raw materials for the detergent (surfactant) composition.

Here, the detergent (surfactant) composition containing the secondary alcohol alkoxylate may be used alone, or may be used in combination with other conventionally known surfactants. Examples of such surfactants include alkylbenzene sulfonates, alkyl sulfate ester salts, α-olefin sulfonates, alkyl sulfonates, aliphatic amide sulfonates, dialkyl sulfosuccinates, and alkyl ether sulfate ester salts. Examples thereof include anionic surfactants such as, alkylamine salts, cationic surfactants such as quaternary ammonium salts, and amphoteric ion surfactants such as alkylbetaine.

Various additives can be added to the detergent (surfactant) composition containing the secondary alcohol alkoxylate. Such additives include, for example, alkaline agents, builders, fragrances, optical brighteners, colorants, foaming agents, foam stabilizers, polishes, bactericides, bleaches, enzymes, preservatives, dyes, solvents. And so on.

Detergent (surfactant) compositions containing secondary alcohol alkoxylates are cleaning agents for clothing, textiles, tableware, containers, general merchandise, food, building maintenance products, homes, furniture, automobiles, aircraft, metal products, etc. , Shampoo, body shampoo, etc., can be effectively used as a detergent.

Alternatively, the secondary alcohol alkoxylate may be used as an emulsifier. The oily substance that can be used at this time is not particularly limited, and mineral oil, animal and vegetable oil, synthetic oil, and the like can be used. These can be used alone or in combination of two or more. Examples of mineral oils include spindle oils, machine oils, liquid paraffin oils and the like. Examples of animal and vegetable oils include beef tallow, pork fat, fish oil, whale oil, rapeseed oil, sesame oil, palm oil, soybean oil, palm oil, camellia oil, and castor oil. In one embodiment of the present invention, the emulsifier can be used for pesticides, metalworking oils, paints, emulsion polymerization emulsifiers and the like.

The effects of the present invention will be described with reference to the following examples and comparative examples. However, the technical scope of the present invention is not construed as being limited to the following Examples and Comparative Examples, and Examples obtained by appropriately combining the technical means disclosed in each Example are also the scope of the present invention. include. In the following examples, the operation was performed at room temperature (25 ° C.) unless otherwise specified. Unless otherwise specified, "%" and "parts" mean "mass%" and "parts by mass", respectively.

Example 1
1000 g of a mixture of saturated aliphatic hydrocarbons having 12 to 14 carbon atoms (average molecular weight: 184) and 25 g of metaboric acid were placed in a cylindrical reactor having a capacity of 3 L, and the oxygen concentration was 3.5 vol% and the nitrogen concentration was 96.5 vol%. Gas was blown at a rate of 430 L per hour, and a liquid phase oxidation reaction was carried out at 170 ° C. under normal pressure for 2 hours to obtain an oxidation reaction mixture (oxidation reaction step). The mixture of saturated aliphatic hydrocarbons having 12 to 14 carbon atoms used as a raw material is the total mass of a mixture of saturated aliphatic hydrocarbons having 12 to 14 carbon atoms and saturated aliphatic hydrocarbons having 12 to 14 carbon atoms. It is contained in a proportion exceeding 95% by mass with respect to.

This oxidation reaction mixture was treated at 200 hPa at 170 ° C., and the alcohol contained therein was orthoboric acid esterified to obtain a borate compound (boric acid ester mixture) (esterification step). Next, this borate compound (borate ester mixture) was flash-distilled at 170 ° C. (column bottom temperature) at 7 hPa (unreacted saturated aliphatic hydrocarbon recovery step). Then, the residual liquid was hydrolyzed with a large amount (2% by mass with respect to the residual liquid) of hot water at 95 ° C. and separated into an aqueous layer containing orthoboric acid and an organic layer (hydrolysis step). The obtained organic layer was saponified and washed with water at 140 ° C. using sodium hydroxide to remove organic acids and organic acid esters (saponification step). This organic layer was fractionated at 7 hPa to obtain a boiling point range of 95 to 120 ° C. as the first fraction and a boiling point range of 120 to 150 ° C. as the second fraction (purification step). Here, the first fraction (distill at 95 ° C. or higher and lower than 120 ° C.) was a mixture of a small amount of saturated aliphatic hydrocarbon, carbonyl compound and monohydric primary alcohol (monoalcohol). The secondary distillate (boiling point range 120-150 ° C. distillate) is a mixture of a trace amount of a carbonyl compound and a secondary alcohol (monoalcohol), in which the majority of the secondary alcohol is monohydric secondary. It is an alcohol and contains a secondary alcohol having 12 to 14 carbon atoms in a proportion of more than 95% by mass based on the total mass of the mixture. As this second fraction, a mixture of secondary alcohols (average molecular weight: 200) was obtained.

The mixture of the secondary alcohol obtained above (average molecular weight: 200) was charged into a tube-type first reactor (tube-type reactor, internal volume: 10 L) at 10 kg / hr, and boron trifluoride ether was added. The complex (acid catalyst) was supplied at 24 g / hr. A total of nine thermometers were installed in the first reactor at a position where the maximum reaction temperature was captured from the reactor inlet.

Next, ethylene oxide was added to the first reactor at the inlet (first stage) of the first reactor, at a location 20 m from the inlet (second stage), and at a location 40 m from the inlet (third stage). The mixture was divided into stages and supplied at 3.3 kg / hr, and an ethoxylation reaction was carried out at 50 ° C. for 55 minutes to obtain a reactant (first alkoxylation reaction step). The ethoxylation reaction temperature was in the range of 40 to 70 ° C. The amount of ethylene oxide supplied in the ethoxylation reaction was about 1.5 mol with respect to 1 mol of the mixture of secondary alcohols. The above-mentioned reactant was supplied to a second reactor (tank reactor, internal volume: 10 L) and further subjected to an ethoxylation reaction at 50 ° C. for 55 minutes to obtain a reactant containing ethylene oxide adduct A.

Then, at 90 ° C., a 1 mass% NaOH aqueous solution was added to the reaction product to separate it into an organic layer and an aqueous layer, and then water was added to the organic layer to add an organic layer containing a secondary alcohol ethoxylate precursor and an aqueous layer. To obtain a liquid containing ethylene oxide adduct B having an average number of ethylene oxide adducts of 1.7 (washing step).

Next, the liquid containing the ethylene oxide adduct B obtained above is supplied to the first reservoir cut column (light separation column), and the light substance is distilled off at a bottom temperature of 190 ° C. and a top pressure of 3 hPa to distill off the bottom liquid. Was recovered. This bottom liquid is supplied to an alcohol recovery column (rectification column), distilled at a bottom temperature of 190 ° C. and a top pressure of 25 hPa, and unreacted alcohol and a low EO molar addition fraction are distilled off to obtain a secondary alcohol. An ethoxylate precursor was obtained (purification step). With respect to the obtained secondary alcohol ethoxylate precursor, the average number of ethylene oxide addition moles (average EO addition mole number) of the secondary alcohol ethoxylate precursor was measured according to the following method and found to be 2.9. ..

(1) Measurement of the average number of ethylene oxide addition moles (average number of EO addition moles) of the secondary alcohol ethoxylate precursor The average number of ethylene oxide addition moles (average) of the secondary alcohol ethoxylate precursor isolated above. The EO addition molar number (n)) is calculated from the analytical value of the hydroxyl value using the following formula 2. The hydroxyl value is measured based on the B method of JIS K1557-1: 2007. Specifically, the sample is a pyridine solution containing phthalic anhydride, and the hydroxyl groups are phthalated under reflux of pyridine. This reaction is promoted using imidazole as a catalyst. The excess phthalate reagent is hydrolyzed with water and the resulting phthalic acid is titrated with a standard solution of sodium hydroxide. The hydroxyl value is measured by calculating from the difference in titration between the blank test and the sample test.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 1 below (the position of the EO supply unit in Table 1). In the column _{of "X n'} <X _{n'+ 1} " in Table 1 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 1 below, n is 9, and the number of sets of three adjacent ethylene oxide supply units (N [X _n' , X _{n'+ 1} ]) _{satisfying X n'} <X _{n'+1 is} Since it is 6, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.8 (= 6/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 1 below (the position of the EO supply unit in Table 1). , The amount shown in Table 1 below (EO supply amount in Table 1) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by the 10 thermometers installed was 160 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 1 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is set to "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 1 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 8, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.9 (= 8/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized with acetic acid until the pH reached 6, to obtain a secondary alcohol ethoxylate (1).

Regarding the secondary alcohol ethoxylate (1) obtained above, the average number of moles of ethylene oxide added (average number of moles of EO added) was measured according to the following method and found to be 9. The hue (APHA) of the obtained secondary alcohol ethoxylate (1) was evaluated according to the following method and found to be 50 to 55.

(2) Measurement of average number of ethylene oxide addition moles (average number of EO addition moles) of secondary alcohol ethoxylate)
The average number of moles of ethylene oxide added (average number of moles of EO added (n')) of the secondary alcohol ethoxylate isolated above is calculated from the analytical value of the hydroxyl value using the following formula 3. The hydroxyl value is measured based on the B method of JIS K1557-1: 2007. Specifically, the sample is a pyridine solution containing phthalic anhydride, and the hydroxyl groups are phthalated under reflux of pyridine. This reaction is promoted using imidazole as a catalyst. The excess phthalate reagent is hydrolyzed with water and the resulting phthalic acid is titrated with a standard solution of sodium hydroxide. The hydroxyl value is measured by calculating from the difference in titration between the blank test and the sample test.

(3) Evaluation of hue The secondary alcohol ethoxylate was put up to the marked line of the colorimetric tube, placed on white paper, and compared with the standard solution in natural light. At this time, the number of Hazen unit colors (platinum-cobalt scale) (APHA No.) corresponding to the hue of the sample was selected by comparing the bottom surface from the mouth of the colorimetric tube. The smaller the hue (APHA No.) in Table 1 below, the less the coloring. If the hue (APHA No.) is 70 or less, it is practically acceptable, and it is desirable that the hue (APHA No.) is 65 or less (particularly 60 or less).

Example 2
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 2 below (the position of the EO supply unit in Table 2). In the column _{of "X n'} <X _{n'+ 1} " in Table 2 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 2, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 4, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.5 (= 4/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 2 below (the position of the EO supply unit in Table 2). , The amount shown in Table 2 below (EO supply amount in Table 2) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 163 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 2 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is set to "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 2 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 8, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.9 (= 8/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a secondary alcohol ethoxylate (2).

Regarding the secondary alcohol ethoxylate (2) obtained above, the average number of moles of ethylene oxide added (average number of moles of EO added) was measured according to the method described in Example 1 and found to be 9. Moreover, when the hue (APHA) of the obtained secondary alcohol ethoxylate (2) was evaluated according to the method described in Example 1, it was 60 to 65.

Example 3
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 3 below (the position of the EO supply unit in Table 3). In the column _{of "X n'} <X _{n'+ 1} " in Table 3 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 3 below, n is 9, and the number of sets of three adjacent ethylene oxide supply units (N [X _n' , X _{n'+ 1} ]) _{satisfying X n'} <X _{n'+1 is} Since it is 4, N [X _n' , X _{n'+ 1} ] / (n-1) is 0.5 (= 4/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 3 below (the position of the EO supply unit in Table 3). , The amount shown in Table 3 below (EO supply amount in Table 3) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 162 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 3 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 3 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 9, N [Y _{n "} , Y _{n" + 1} ] / n is 1.0 (= 9/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a secondary alcohol ethoxylate (3).

With respect to the secondary alcohol ethoxylate (3) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1, and it was 9. Further, when the hue (APHA) of the obtained secondary alcohol ethoxylate (3) was evaluated according to the method described in Example 1, it was 55 to 60, but it was visually slightly colored as compared with Example 1. Was.

Example 4
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 4 below (the position of the EO supply unit in Table 4). In the column _{of "X n'} <X _{n'+ 1} " in Table 4 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 4, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 6, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.8 (= 6/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 4 below (the position of the EO supply unit in Table 4). , The amount shown in Table 4 below (EO supply amount in Table 4) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 162 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 4 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is set to "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 4 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 6, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.7 (= 6/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a secondary alcohol ethoxylate (4).

With respect to the secondary alcohol ethoxylate (4) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1, and it was 9. Moreover, when the hue (APHA) of the obtained secondary alcohol ethoxylate (4) was evaluated according to the method described in Example 1, it was 60 to 65.

Example 5
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 5 below (the position of the EO supply unit in Table 5). In the column _{of "X n'} <X _{n'+ 1} " in Table 5 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 5, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 6, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.8 (= 6/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 5 below (the position of the EO supply unit in Table 5). , The amount shown in Table 5 below (EO supply amount in Table 5) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 167 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 5 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 5 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 4, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.4 (= 4/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a secondary alcohol ethoxylate (5).

With respect to the secondary alcohol ethoxylate (5) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1, and it was 9. Moreover, when the hue (APHA) of the obtained secondary alcohol ethoxylate (5) was evaluated according to the method described in Example 1, it was 65 to 70.

Comparative Example 1
The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 6 below (the position of the EO supply unit in Table 6). In the column _{of "X n'} <X _{n'+ 1} " in Table 6 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 6, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 0, N [X _n' , X _{n'+ 1} ] / (n-1) is 0 (= 0/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 6 below (the position of the EO supply unit in Table 6). , The amount shown in Table 6 below (EO supply amount in Table 6) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 175 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 6 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 6 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 0, N [Y _{n "} , Y _{n" + 1} ] / n is 0 (= 0/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a comparative secondary alcohol ethoxylate (1).

With respect to the comparative secondary alcohol ethoxylate (1) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1 and found to be 9. Moreover, when the hue (APHA) of the obtained comparative secondary alcohol ethoxylate (1) was evaluated according to the method described in Example 1, it was 75 to 80.

Comparative Example 2
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, an ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 7 below (the position of the EO supply unit in Table 7). In the column _{of "X n'} <X _{n'+ 1} " in Table 7 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 7, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 6, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.8 (= 6/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 7 below (the position of the EO supply unit in Table 7). , The amount shown in Table 7 below (EO supply amount in Table 7) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 175 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 7 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 7 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 0, N [Y _{n "} , Y _{n" + 1} ] / n is 0 (= 0/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a comparative secondary alcohol ethoxylate (2).

With respect to the comparative secondary alcohol ethoxylate (2) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1 and found to be 9. Moreover, when the hue (APHA) of the obtained comparative secondary alcohol ethoxylate (2) was evaluated according to the method described in Example 1, it was 75 to 80.

Comparative Example 3
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 8 below (the position of the EO supply unit in Table 8). In the column _{of "X n'} <X _{n'+ 1} " in Table 8 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 8, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 2, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.3 (= 2/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 8 below (the position of the EO supply unit in Table 8). , The amount shown in Table 8 below (EO supply amount in Table 8) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 172 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 8 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 8 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 2, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.2 (= 2/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a comparative secondary alcohol ethoxylate (3).

With respect to the comparative secondary alcohol ethoxylate (3) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1 and found to be 9. Moreover, when the hue (APHA) of the obtained comparative secondary alcohol ethoxylate (3) was evaluated according to the method described in Example 1, it was 70 to 75.

Comparative Example 4
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, an ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 9 below (the position of the EO supply unit in Table 9). In the column _{of "X n'} <X _{n'+ 1} " in Table 9 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 9, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 2, N [X _n' , X _{n'+ 1} ] / (n-1) is about 0.3 (= 2/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 9 below (the position of the EO supply unit in Table 9). , The amount shown in Table 9 below (EO supply amount in Table 9) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 171 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 9 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 9 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 3, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.3 (= 3/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a comparative secondary alcohol ethoxylate (4).

With respect to the comparative secondary alcohol ethoxylate (4) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1 and found to be 9. Moreover, when the hue (APHA) of the obtained comparative secondary alcohol ethoxylate (4) was evaluated according to the method described in Example 1, it was 70 to 75.

Comparative Example 5
A secondary alcohol ethoxylate precursor was obtained in the same manner as in Example 1.

The secondary alcohol ethoxylate precursor obtained above (average number of moles of EO added = 2.9) was placed in the second reactor (U-shaped reactor, outer diameter: 32 mm, inner diameter: 28 mm, tube length: 650 m). Was supplied at 1050 kg / hr, a 48 mass% sodium hydroxide aqueous solution at 950 g / hr, and ethylene oxide at 850 kg / hr. The second reactor had a structure in which 33 U-shaped reaction tubes having a tube length of 10 m were repeatedly connected. Further, in the second reactor, the ethylene oxide supply unit (EO supply unit) was installed at the position shown in Table 10 below (the position of the EO supply unit in Table 10). In the column _{of "X n'} <X _{n'+ 1} " in Table 10 below, the set of three adjacent ethylene oxide supply units satisfying _{X n'} <X _{n'+ 1 is set to "○", and X n'} < A set of three adjacent ethylene oxide feeders that do not satisfy X _{n'+ 1 (ie, X n'} > X _{n'+ 1} or X _n' = X _{n'+ 1} ) is indicated by "x", respectively. As shown in Table 10, n is _{9, X n '<X n} ' + 1 3 single ethylene oxide feed unit number of sets of adjacent satisfy _{(N [X n ', X} n' + 1]) is Since it is 4, N [X _n' , X _{n'+ 1} ] / (n-1) is 0.5 (= 4/8). In addition, a total of 10 thermometers were installed near each ethylene oxide supply in the second reactor.

Next, ethylene oxide (EO) is applied to the second reactor via the ethylene oxide supply unit (EO supply unit) installed at the position shown in Table 10 below (the position of the EO supply unit in Table 10). , The amount shown in Table 10 below (EO supply amount in Table 10) was supplied, and the ethoxylation reaction was carried out at an initial nitrogen pressure of 1.0 to 2.0 MPa and 140 to 160 ° C. for 0.5 to 1.0 hours. Further, a reaction product containing a secondary alcohol ethoxylate was obtained. At this time, the maximum reaction temperature of the tubular reactor measured by all 10 thermometers was 172 ° C. In addition, ethylene oxide (EO) was supplied on the tube plate surface of the second reactor (the ethylene oxide supply section was installed on substantially the same tube plate surface). Furthermore, the total supply of ethylene oxide in the ethoxylation reaction was about 6 mol with respect to 1 mol of the secondary alcohol ethoxylate precursor. In the column _{of "Y n"} <Y _{n "+1} " in Table 10 below, the set of two adjacent ethylene oxide supply units satisfying _{Y n "} <Y _{n" + 1 is "○", and Y n "} < A set of two adjacent ethylene oxide feeders that do not satisfy Y _{n "+1 (ie, Y n"} > Y _{n "+1} or Y _n" = Y _{n "+1} ) is indicated by" x ", respectively. As shown in Table 10 below, n is 9, and the number of sets of two adjacent ethylene oxide supply units (N [Y _{n "} , Y _{n" + 1} ]) _{satisfying Y n "} <Y _{n" + 1 is} Since it is 2, N [Y _{n "} , Y _{n" + 1} ] / n is about 0.2 (= 2/9).

The reaction product containing the secondary alcohol ethoxylate obtained above was neutralized in the same manner as in Example 1 to obtain a comparative secondary alcohol ethoxylate (5).

The average number of ethylene oxide-added moles (average number of EO-added moles) of the comparative secondary alcohol ethoxylate (5) obtained above was measured according to the method described in Example 1 and found to be 9. Moreover, when the hue (APHA) of the obtained comparative secondary alcohol ethoxylate (5) was evaluated according to the method described in Example 1, it was 70 to 75.

_{N [X n'} , X _{n'+ 1} ] / (n-1) and N [Y _{n "} , Y _{n" + 1} ] / n of the second reactors of Examples 1 to 5 and Comparative Examples 1 to 5 above. The maximum reaction temperature of the second reactor and the hue of each secondary alcohol ethoxylate are summarized in Table 11 below.

As shown in Table 11 above, the secondary alcohol ethoxylates (1) to (5) of the examples are superior in hue to the comparative secondary alcohol ethoxylates (1) to (5). I understand. In this example, the evaluation was made with a tubular reactor having a tube length of about 400 m, but it is considered that the same result as above can be obtained with a tubular reactor having a longer tube length (for example, 700 to 1000 m). NS.

Example 6
1000 g of a mixture of saturated aliphatic hydrocarbons having 12 to 14 carbon atoms (average molecular weight: 184) and 25 g of metaboric acid were placed in a cylindrical reactor having a capacity of 3 L, and the oxygen concentration was 3.5 vol% and the nitrogen concentration was 96.5 vol%. Gas was blown at a rate of 430 L per hour, and a liquid phase oxidation reaction was carried out at 170 ° C. under normal pressure for 2 hours to obtain an oxidation reaction mixture (oxidation reaction step). The mixture of saturated aliphatic hydrocarbons having 12 to 14 carbon atoms used as a raw material is the total mass of a mixture of saturated aliphatic hydrocarbons having 12 to 14 carbon atoms and saturated aliphatic hydrocarbons having 12 to 14 carbon atoms. It is contained in a proportion exceeding 95% by mass with respect to.

This oxidation reaction mixture was treated at 200 hPa at 170 ° C., and the alcohol contained therein was orthoboric acid esterified to obtain a borate compound (boric acid ester mixture) (esterification step). Next, this borate compound (borate ester mixture) was flash-distilled at 170 ° C. (column bottom temperature) at 7 hPa (unreacted saturated aliphatic hydrocarbon recovery step). Then, the residual liquid was hydrolyzed with a large amount (2% by mass with respect to the residual liquid) of hot water at 95 ° C. and separated into an aqueous layer containing orthoboric acid and an organic layer (hydrolysis step). The obtained organic layer was saponified and washed with water at 140 ° C. using sodium hydroxide to remove organic acids and organic acid esters (saponification step). This organic layer was fractionated at 7 hPa to obtain a boiling point range of 95 to 120 ° C. as the first fraction and a boiling point range of 120 to 150 ° C. as the second fraction (purification step). Here, the first fraction (distill at 95 ° C. or higher and lower than 120 ° C.) was a mixture of a small amount of saturated aliphatic hydrocarbon, carbonyl compound and monohydric primary alcohol (monoalcohol). The secondary distillate (boiling point range 120-150 ° C. distillate) is a mixture of a trace amount of a carbonyl compound and a secondary alcohol (monoalcohol), in which the majority of the secondary alcohol is monohydric secondary. It is an alcohol and contains a secondary alcohol having 12 to 14 carbon atoms in a proportion of more than 95% by mass based on the total mass of the mixture. As this second fraction, a mixture of secondary alcohols (average molecular weight: 200) was obtained.

A mixture of secondary alcohols having 12 to 14 carbon atoms (average molecular weight: 200) was charged into a tube-type first reactor (tube-type reactor, internal volume: 10 L) at 10 kg / hr, and boron trifluoride was added. The ether complex (acid catalyst) was supplied at 24 g / hr. The mixture of the secondary alcohol as a raw material contains a secondary alcohol having 12 to 14 carbon atoms in a ratio of more than 95% by mass with respect to the total mass of the mixture. In addition, a total of nine thermometers were installed in the first reactor at a position where the maximum reaction temperature was captured from the reactor inlet.

Next, ethylene oxide was added to the first reactor at the inlet (first stage) of the first reactor, at a location 20 m from the inlet (second stage), and at a location 40 m from the inlet (third stage). The mixture was divided into stages and supplied at 3.0 kg / hr, and an ethoxylation reaction was carried out at 50 ° C. for 55 minutes to obtain a reactant. The ethoxylation reaction temperature was in the range of 40 to 70 ° C. The amount of ethylene oxide supplied in the ethoxylation reaction was about 1.4 mol with respect to 1 mol of the mixture of secondary alcohols.

The above-mentioned reactant was supplied to a second reactor (tank reactor, internal volume: 10 L) and further subjected to an ethoxylation reaction at 50 ° C. for 55 minutes to obtain a reactant containing an ethylene oxide adduct.

The reaction product 14.8 L / hr and 1 mass% sodium hydroxide aqueous solution 3.7 L / hr obtained above were put into the first mixing tank of a mixer-settler type device, and stirred at 95 ° C. for 15 minutes. , Washed. Then, this mixture is transferred to the first stationary tank of a mixer-settler type device, and allowed to stand in the first stationary tank at 75 ° C. for 30 minutes to form an organic layer containing an ethylene oxide adduct (organic layer 1-). It was separated into 1) and an aqueous layer. This organic layer (organic layer 1-1) 14.8 L / hr and water 3.7 L / hr are put into the second mixing tank of a mixer-settler type device, stirred at 95 ° C. for 15 minutes, and washed. went. Then, this mixture is transferred to a second stationary tank of a mixer-settler type device, and allowed to stand at 70 ° C. for 30 minutes in the second stationary tank to form an organic layer (organic) containing an ethylene oxide adduct (1). The layer 1-2) was separated into an aqueous layer to obtain a liquid (1) containing an ethylene oxide adduct (1) (alkylene oxide adduct B) having an average number of ethylene oxide adducts of 1.6.

Further, with respect to the obtained organic layer (organic layer 1-2), the presence of an emulsified layer was visually determined at the interface between the organic layer and the aqueous layer in the second static tank. As a result, no emulsified layer was observed at the interface between the organic layer and the aqueous layer (less than 5% with respect to the total area of the liquid surface). Further, with respect to the obtained organic layer (organic layer 1-2), the presence of crystals in the organic layer in the second standing tank was visually determined. As a result, no crystals were observed in the organic layer.

Next, the liquid (1) containing the ethylene oxide adduct (1) obtained above is supplied to the first reservoir cut column (light separation column), and the light substance is retained at a bottom temperature of 190 ° C. and a top pressure of 3 hPa. The bottom liquid was collected. This bottom liquid is supplied to an alcohol recovery column (rectification column), distilled at a bottom temperature of 190 ° C. and a top pressure of 25 hPa, and unreacted alcohol and a low EO molar addition fraction are distilled off to obtain a secondary alcohol. An ethoxylate precursor (2) was obtained. The average number of moles of ethylene oxide added (p in the formula (2)) of the obtained secondary alcohol ethoxylate precursor (2) was measured and found to be 2.9. Further, the hue (APHA) of the obtained secondary alcohol ethoxylate precursor (2) was evaluated according to the method described in Example 1 and found to be 20 to 30.

In Example 1, a secondary alcohol ethoxylate (6) was obtained in the same manner as in Example 1 except that the secondary alcohol ethoxylate precursor (2) obtained above was used instead. ..

With respect to the secondary alcohol ethoxylate (6) obtained above, the average number of ethylene oxide addition moles (average number of EO addition moles) was measured according to the method described in Example 1, and it was 9. Moreover, when the hue (APHA) of the obtained secondary alcohol ethoxylate (6) was evaluated according to the method described in Example 1, it was 50 to 55.

Claims (7)

The alkylene oxide is added to the secondary alcohol alkoxylate precursor via the alkylene oxide supply section installed at the inlet of the tubular reactor and at n locations other than the inlet (n is an integer of 2 or more). The secondary alcohol alkoxylate precursor is reacted with the alkylene oxide in the tubular reactor.
The alkylene oxide supply unit is installed in the tubular reactor so as to satisfy the following formula (1), and the alkylene oxide is further added to the secondary alcohol alkoxylate precursor so as to satisfy the following formula (2). Method for producing secondary alcohol alkoxylate to be added:

The method according to claim 1, wherein the alkylene oxide supply unit is installed in the tubular reactor so as to satisfy the following formula (1'):

In the above formula (1'), N [X _n' , X _{n'+ 1} ] has the same definition as the above formula (1). In the formula (1), if it meets X _{n '<X n' + 1, + 1} ratio _'the X _n with respect _to' the X _n (X _{n '+} 1 / X _n') is 1.10 or more, wherein Item 2. The method according to item 1 or 2. The method according to any one of claims 1 to 3, wherein the alkylene oxide supply unit is installed at 2 to 30 places per 1000 m of the tubular reactor. The method according to any one of claims 1 to 4, wherein the tubular reactor has a U-shaped reaction tube. The method according to any one of claims 1 to 5, further comprising measuring the temperature at at least one place other than the inlet of the tubular reactor. The secondary alcohol alkoxylate precursor has the following formula (C):

In the above formula (C), X represents an alkylene group having 1 to 3 carbon atoms; the total (x + y) of x and y is an integer of 8 to 12; m is 2.5 or more and 3.5 or less. be,
In the presence of a catalyst, a secondary alcohol is reacted with an alkylene oxide to obtain a reaction solution containing an alkylene oxide adduct A, the reaction solution is mixed with water, and then allowed to stand at a temperature exceeding 60 ° C. Then, it is separated into an aqueous layer and an organic layer, and the following formula (B):

In the above formula (B), X and x and y have the same definition as the above formula (C); k is 5 or more and 50 or less.
The method according to any one of claims 1 to 6, which is obtained by obtaining a liquid containing the alkylene oxide adduct B represented by the above and purifying the liquid.

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