JP3429653B2 - Method for producing light-colored anionic surfactant - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a light-colored anionic surfactant. More specifically, the present invention relates to a method for producing a light-colored anionic surfactant comprising a sulfuric acid ester salt of a higher alcohol or an alkylene oxide adduct thereof.

[0002]

BACKGROUND OF THE INVENTION Anionic surfactants, which are composed of sulfates of higher alcohols or their alkylene oxide adducts, are widely used as main active agents for dish detergents, shampoos, laundry detergents and the like. However, at present, it has a pale yellow color, and its lightening and colorlessness are desired to improve the commercial value.

Bleaching is generally used as a method for producing a light-colored anionic surfactant. Bleaching agents used for such bleaching treatment are roughly classified into chlorine-based and oxygen-based bleaching agents, and hypochlorites (Na, K salts, etc.) as chlorine-based bleaching agents,
Hydrogen peroxide is mainly used as an oxygen-based bleaching agent.
From the viewpoint of bleaching effect, it is better to use hypochlorite,
It has been pointed out that the sulfuric acid ester salt of an alkylene oxide adduct of a higher alcohol treated with hypochlorite is sensitizing to the skin, and under the present circumstances, bleaching with hypochlorite is not adopted due to voluntary regulation of the Japan Industrial Association.

On the other hand, hydrogen peroxide has a low bleaching effect, and it is necessary to use a large amount of hydrogen peroxide for fading.
Therefore, hydrogen peroxide may remain in the aqueous surfactant solution or slurry, and if the amount of residual hydrogen peroxide is large, it may cause discoloration of the dye in the product when blended in shampoo or the like.

Further, as a method for producing a light-colored anionic surfactant, Japanese Patent Publication No. 60-51520 discloses a method for producing an aqueous solution or slurry of anionic surfactant, hydrogen peroxide or a hydrogen peroxide generating substance, succinic anhydride or anhydrous. A method of acting benzoic acid is described. However, in this method, the peroxide remains, and it is necessary to remove the residual peroxide by thermal decomposition or sulfite after the bleaching treatment.

Therefore, the present invention has been made by paying attention to such a problem, and an object of the present invention is to safely and reduce the amount of the bleaching agent used, to reduce the cost, and to efficiently generate the anion. It is an object of the present invention to provide a method for producing a light-colored anionic surfactant, which can lighten the surfactant and further reduce the amount of residual oxidizing agents such as hydrogen peroxide.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, sulphated a higher alcohol or an alkylene oxide adduct thereof with sulfur trioxide gas or chlorosulfonic acid. Later, when neutralizing, simultaneously with or after the neutralization, the anionic surfactant aqueous solution or slurry is bleached with a reducing agent, and then bleached with an oxidizing agent to give a safe and bleaching agent. The inventors have found that the amount of use can be reduced, the cost of the anionic surfactant aqueous solution or the slurry can be efficiently reduced, and the present invention has been completed.

That is, the present invention comprises a sulfuric acid ester salt of a higher alcohol or an alkylene oxide adduct thereof after sulfating the higher alcohol or an alkylene oxide adduct thereof with sulfur trioxide gas or chlorosulfonic acid. In the method for producing an anionic surfactant,
Simultaneous with or after neutralization, an anionic surfactant aqueous solution or slurry is bleached with a reducing agent, and then a bleaching treatment with an oxidizing agent is provided. is there.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

In the present invention, examples of the higher alcohol or the alkylene oxide adduct thereof which is a raw material for sulfation include compounds represented by the following general formula (I).

RO (AO) _n H (I) (In the formula, R represents a linear or branched alkyl group having 8 to 20 carbon atoms, A represents an alkylene group having 2 to 3 carbon atoms,
The n A's may be the same or different. n is a number from 0 to 10 that indicates the average number of moles of alkylene oxide added. ) Specific examples of the higher alcohol represented by the above general formula (I) include natural alcohols derived from matcha oil, coconut oil, palm oil, beef tallow, etc., and further oxo method, Ziegler method and paraffin direct oxidation method. The obtained C8-C20 synthetic alcohol etc. are mentioned.

Examples of the alkylene oxide adduct of the higher alcohol represented by the above general formula (I) include ethylene oxide and / or propylene oxide adduct of the higher alcohol, and ethylene oxide having an average addition mole number of 1 to 10 is mentioned. Adducts are especially preferred.

In the present invention, the higher alcohol or alkylene oxide adduct thereof as described above is first sulphated with sulfur trioxide gas or chlorosulfonic acid and then neutralized to give a higher alcohol or alkylene oxide adduct thereof. A sulfate salt is obtained.

Examples of the neutralizing agent used here include sodium hydroxide, potassium hydroxide, ammonium hydroxide, alkanolamine, diethanolamine and triethanolamine, with sodium hydroxide and ammonium hydroxide being preferred.

The concentration of the neutralizing agent is not particularly limited, and it is preferable that sufficient fluidity can be obtained according to the viscosity behavior in the concentration of the anionic surfactant aqueous solution or slurry after neutralization. For example, in the case of a higher alcohol sulfate ester salt, the concentration after neutralization is 30% by weight or less or 60% or less.
In the case of a sulfuric acid ester salt of an alkylene oxide adduct of a higher alcohol, the concentration after neutralization is up to 30% by weight.
It is preferable that the amount is less than or equal to wt% or 55 to 80 wt%. In these ranges, although the viscosity is somewhat high,
Sufficient fluidity is obtained for operation.

In the method of the present invention, the aqueous solution or slurry of anionic surfactant is first bleached with a reducing agent and then with an oxidizing agent, simultaneously with or after the neutralization as described above. That is, first, bleaching is performed with a reducing agent having a relatively high bleaching rate, and then oxidization having a slower bleaching rate than that of the reducing agent is performed to simultaneously decompose the remaining reducing substance and bleach. As a result, the amount of bleach used can be reduced and a high bleaching effect can be obtained.

A neutralization method in the production of an anionic surfactant comprising a sulfuric acid ester salt of a higher alcohol or an alkylene oxide adduct thereof is such that the sulfuric acid ester and the neutralizing agent are continuously neutralized (expressed as the first stage continuous neutralization). After that, the pH is generally adjusted by a batch operation or the pH is controlled by a continuous operation (expressed as second-stage neutralization). In the method of the present invention, when the bleaching treatment is carried out simultaneously with the neutralization, a reducing agent can be added to the first-stage continuous neutralization system and an oxidizing agent can be added to the second-stage neutralization system. It is not necessary to install bleaching equipment in the above, and the equipment cost is reduced, which is preferable. After further adding an oxidant and stirring and mixing,
For example, it may be left alone in a product storage tank or the like.

In the present invention, the reducing agent may be at least one selected from sulfur dioxide, sulfurous acid and salts thereof, bisulfite and salts thereof, and the like, and preferably bisulfite salt. When the reducing agent is a salt, as its counter ion,
Alkali metal, alkaline earth metal and the like can be used, but sodium salt is preferable. The addition amount of the reducing agent depends on the hue of the anionic surfactant aqueous solution or slurry after neutralization, but is preferably 0.001 to 1% by weight as a pure component per effective component of the anionic surfactant aqueous solution or slurry, More preferably 0.001 to 0.5% by weight. If the amount of the reducing agent added is too large, the reducing agent is wasted, which is not preferable.

When sulfur trioxide is used as the sulfating agent, sulfur dioxide contained in sulfur trioxide can be added to the neutralization system as a reducing agent. Normally, sulfur trioxide is produced by burning liquid sulfur into sulfur dioxide, and then producing sulfur trioxide with a vanadium pentoxide catalyst. By controlling the conversion rate of sulfur dioxide to sulfur trioxide in this process, sulfur dioxide can be added and used as a reducing agent to the neutralization system.

Hydrogen peroxide is preferably used as the oxidizing agent in the present invention. The amount of the oxidizing agent added is preferably 0.001 to 1% by weight in terms of pure content, based on the effective content of the anionic surfactant aqueous solution or slurry, and more preferably the equivalent amount to the added reducing agent. If the amount of the oxidizing agent added is too large, the oxidizing agent such as hydrogen peroxide may remain, which may cause a problem such as fading of the dye in the product. If the amount is small, the reducing substance may remain, and if the reducing substance remains, problems such as deactivation of the preservative (Caison CG etc.) and fading of the dye in the product may occur.

As for the pH of the bleaching treatment, it is preferable that the bleaching with a reducing agent is carried out at a pH of 10 or less, particularly 2 to 8. If the pH exceeds 10, the bleaching effect will be insufficient and
If it is less than the range, deterioration of odor (odor of aldehyde) may occur.
Further, the pH of the bleaching treatment with the oxidizing agent is not particularly limited, and may be the required product standard or the like.

The bleaching temperature in the present invention is 20 to 90.
C, preferably 30 to 70C. Within this range, the higher aldehyde, which is an odorous component, is scarcely produced and the odor is not deteriorated.

The bleaching time depends on the hue of the anionic surfactant aqueous solution or slurry at the time of neutralization or after neutralization, but the bleaching time with a reducing agent is preferably 10 minutes or longer, and particularly preferably 30 minutes or longer. If the bleaching time with the reducing agent is short, the bleaching effect of the reducing agent becomes small, and the reducing agent is wasted by reacting with the oxidizing agent added next. Although bleaching with an oxidizing agent has a slower bleaching speed than bleaching with a reducing agent, depending on the final target hue, it is preferably 6 hours or longer, particularly 12 hours or longer.

[0024]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and the like. In the examples,% is based on weight unless otherwise specified.

Example 1 (1) Synthesis of higher alcohol ethoxylate sulfate ester salt A higher alcohol mainly containing 12 carbon atoms (trade name Calcor 2098, manufactured by Kao Corporation,
98% carbon number 12 ethoxylates (brand name Emulgen 102.5, manufactured by Kao Corporation, molecular weight 295, average E
The number of moles of O added (2.5) is sulphated with sulfur trioxide gas diluted with dry air, and the concentration of the higher alcohol ethoxylate sulfate sodium salt after neutralization is 25% with a 3.4% aqueous sodium hydroxide solution. The solution was neutralized on the alkaline side (pH 10 to 12) to prepare an aqueous solution of (1) to prepare an aqueous solution of higher alcohol ethoxylate sulfate sodium salt.

(2) An aqueous solution of higher alcohol ethoxylate sulfate sodium salt prepared by the bleaching treatment (1) was charged into a tank reactor,
Adjust to pH 7.1 with sulfuric acid and 5.0% as a reducing bleaching agent.
Aqueous sodium bisulfite solution was added in the amount shown in Table 1, and bleaching treatment was performed at a temperature of 40 ° C. for 1 hour. Next, 1.0% hydrogen peroxide solution as an oxidizing bleaching agent was added in an amount shown in Table 1 and mixed,
It was stored for 24 hours at a temperature of 40 ° C. and protected from light and bleached.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the following methods. The results are shown in Table 1.

<Method of Measuring Hue> 10 aqueous solutions of higher alcohol ethoxylate sulfate ester salt before and after bleaching treatment are used.
It was diluted so as to be an aqueous solution having a% effective content, and adjusted to pH 7.0 with phosphoric acid or sodium hydroxide. Then 1c
Absorbance at a wavelength of 420 nm was measured by a spectrophotometer using ion-exchanged water as a control in the m-cell, and the value was multiplied by 1000 to obtain a hue.

<Measurement Method of Peroxide Value (POV)> 25
Accurately weigh about 1 g of the sample into a 0 ml Erlenmeyer flask with a stopper, and add 10 ml of chloroform to this,
Gently shake to dissolve the sample. In this case, the sample should be transparently dissolved or slightly cloudy. Further, 15 ml of glacial acetic acid is correctly added to the sample solution, and then 1 ± 0.1 g of potassium iodide powder is added, and the mixture is heated on a water bath with a reflux condenser, and boiling is correctly continued for 3 minutes after the solvent starts to reflux. Then, the Erlenmeyer flask with a stopper was rapidly cooled in running water, 75 ml of water was added thereto, and after vigorously shaking with a stopper, the starch solution was titrated with N / 100 sodium thiosulfate normal solution as an indicator. The end point is when the blue color due to starch disappears. A blank test will be conducted in parallel with this test. From the above titration value, the peroxide value was determined by the following formula.

[0030]

[Equation 1]

Here, A: ml number of N / 100 sodium thiosulfate standard solution of this test B: m of N / 100 sodium thiosulfate standard solution of blank test
l Number F: N / 100 Factor S of sodium thiosulfate normal solution S: sample weight (g) Examples 2 to 3 The higher alcohol ethoxylate used in Example 1 (trade name: Emulgen 102.5) was measured by a rising thin film reactor. ,
Kao Corporation, molecular weight 295, average EO addition mole number 2.
5) was sulphated with sulfur trioxide gas diluted with dry air. Then, the obtained sulfate ester is a loop-type continuous neutralization reactor (inner volume
1,160 cm ³ , residence time 10 minutes, circulation ratio 10 times), under the conditions shown in Table 1, a slurry of higher alcohol ethoxylate sulfate sodium salt after neutralization with a 31.6% sodium hydroxide aqueous solution was used. It is neutralized to a concentration of about 70% and at the same time as a reducing bleaching agent, a neutralization of 0.1%.
An 11% sodium bisulfite aqueous solution was added so as to have the addition amount shown in Table 1, and a 5.1% phosphoric acid aqueous solution was added as a pH buffer to a concentration of 0.25% in the higher alcohol ethoxylate sulfate sodium salt. Was added.

The obtained slurry of higher alcohol ethoxylate sulfate sodium salt was adjusted to pH 6 to 8 with an aqueous solution of sulfuric acid or sodium hydroxide using an Ajihomo mixer (internal volume: 25 liters) manufactured by Tokushu Kikaki. Then, 35% hydrogen peroxide solution was added as an oxidative bleaching agent in an amount shown in Table 1 and mixed. The obtained slurry of higher alcohol ethoxylate sulfate sodium salt was stored at a temperature of 40 ° C. under conditions of light shielding for the time shown in Table 1 and bleached.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 1.

Example 4 Using a falling film reactor, a higher alcohol mainly having 12 and 14 carbon atoms (trade name: Calcol 7-24A, manufactured by Kao Corporation, C ₁₂ / C ₁₄ = 75/25 (weight ratio) )) Ethoxylate (trade name: Emulgen 102KG, Kao Corporation)
Sulfation, neutralization and bleaching treatments were carried out in the same manner as in Examples 2 to 3 under the conditions shown in Table 1 using the product, molecular weight 280, average EO addition mole number 2.0). However, the neutralizer is 27.1
% Aqueous solution of sodium hydroxide, a pH buffer solution of 5.4% phosphoric acid solution, and a reducing bleaching agent of 0.12% sodium bisulfite solution.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 1.

Example 5 The higher alcohol ethoxylate (trade name Emulgen 102KG, used in Example 4 was used in a falling film reactor.
Kao Corporation, molecular weight 280, average EO addition mole number 2.
0) was sulphated, neutralized and bleached under the conditions shown in Table 1 in the same manner as in Examples 2-3. However, the neutralizer is 27.1
% Sodium hydroxide aqueous solution, pH buffer used 5.4% phosphoric acid aqueous solution, and reducing bleach used 0.41% sodium bisulfite aqueous solution.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 1.

Comparative Example 1 An aqueous solution of the higher alcohol ethoxylate sulfate sodium salt prepared in (1) of Example 1 was charged into a tank reactor and adjusted to pH 7.1 with sulfuric acid at a temperature of 40 ° C.
It was stored for 24 hours under the condition of shading.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 2.

Comparative Example 2 An aqueous solution of the higher alcohol ethoxylate sulfate sodium salt prepared in (1) of Example 1 was charged into a tank reactor and adjusted to pH 7.1 with sulfuric acid to give an oxidative bleaching agent of 5. An amount of 0% hydrogen peroxide solution shown in Table 2 was added and mixed, and the mixture was stored for 24 hours at a temperature of 40 ° C. and protected from light, and bleaching treatment was performed.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 2.

Comparative Example 3 The higher alcohol ethoxylate used in Example 1 (trade name Emulgen 102.5,
Kao Corporation, molecular weight 295, average EO addition mole number 2.
5) was sulphated with sulfur trioxide gas diluted with dry air. Then, the obtained sulfate ester is a loop-type continuous neutralization reactor (inner volume
1,160 cm ³ , retention time 10 minutes, circulation ratio 10 times) under the conditions shown in Table 2 with a 31.6% sodium hydroxide aqueous solution to prepare a slurry of higher alcohol ethoxylate sulfate sodium salt after neutralization. Neutralize to a concentration of around 70% and 5.1 as a pH buffer
% Phosphoric acid aqueous solution was added to the higher alcohol ethoxylate sulfate sodium salt to a concentration of 0.25%.

The obtained slurry of higher alcohol ethoxylate sulfate ester salt was adjusted to pH 6-8 with sulfuric acid or sodium hydroxide aqueous solution using a special machine Ajihomo mixer (internal volume 25 liters), and the temperature was adjusted to 40 It was stored for 31 hours under conditions of ℃ and light-shielding.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 2.

Comparative Examples 4 to 5 The higher alcohol ethoxylate used in Example 1 (trade name Emulgen 102.5,
Kao Corporation, molecular weight 295, average EO addition mole number 2.
5) was sulphated with sulfur trioxide gas diluted with dry air. Then, the obtained sulfate ester is a loop-type continuous neutralization reactor (inner volume
1,160 cm ³ , retention time 10 minutes, circulation ratio 10 times) under the conditions shown in Table 2 with a 31.6% sodium hydroxide aqueous solution to prepare a slurry of higher alcohol ethoxylate sulfate sodium salt after neutralization. At the same time, it was neutralized to a concentration of about 70% and at the same time as an oxidative bleaching agent.
11% hydrogen peroxide solution was added to the amount shown in Table 2, and a 5.1% phosphoric acid aqueous solution as a pH buffer was added to the higher alcohol ethoxylate sulfate sodium salt to a concentration of 0.25%. Was added.

The obtained slurry of higher alcohol ethoxylate sulfate sodium salt was adjusted to pH 6 to 8 with sulfuric acid or sodium hydroxide aqueous solution using a special machine Ajihomomixer (internal volume 25 liters), and the temperature was adjusted. It was stored under the conditions of 40 ° C. and light shielding for the time shown in Table 2.

The hue before and after the treatment of the aqueous solution of the higher alcohol ethoxylate sulfate ester salt and the peroxide value (POV) after the treatment were measured by the same method as in Example 1. The results are shown in Table 2.

[0048]

[Table 1]

[0049]

[Table 2]

Note) * 1 Method of adding a bleaching agent: (A) Treating the sulfate ester salt after neutralization with a reducing agent and then an oxidizing agent (B) Treating with a reducing agent during the first-stage continuous neutralization, the second stage Oxidizing agent is treated at the same time (A ') Neutralized sulfuric acid ester salt is treated with oxidizing agent (B') Oxidizing agent is treated at the first stage continuous neutralization * 2 Addition amount: Surfactant aqueous solution or Amount of effective component of slurry * 3 pH: pH as 10% effective component aqueous solution * 4 Hue: Absorbance of 10% effective component aqueous solution (420nm, 1cm cell) x 1000

[0051]

According to the manufacturing method of the present invention, a light-colored anionic surfactant aqueous solution or slurry can be manufactured safely, with a reduced amount of bleach used, and at low cost. . Further, the amount of residual oxidizing agent such as hydrogen peroxide can be reduced.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) C11D 1/29 C07C 303/44 C07C 305/02 Patent file (PATOLIS) JISST file (JOIS)

Claims (5)

(57) [Claims] 1. An anionic surfactant comprising a higher alcohol or an alkylene oxide adduct thereof is sulphated with sulfur trioxide gas or chlorosulfonic acid and then neutralized to form a sulfuric acid ester salt of a higher alcohol or an alkylene oxide adduct thereof. In the method for producing, an aqueous solution or slurry of an anionic surfactant, simultaneously with or after neutralization ,
A small amount selected from sulfurous acid and its salt, bisulfurous acid and its salt
A method for producing a light-colored anionic surfactant, characterized in that at least one reducing agent is added for bleaching treatment, and then bleaching treatment is carried out with an oxidizing agent. 2. The process according to claim 1, wherein the higher alcohol or its alkylene oxide adduct is a compound represented by the general formula (I). RO (AO) _n H (I) (In the formula, R represents a linear or branched alkyl group having 8 to 20 carbon atoms, A represents an alkylene group having 2 to 3 carbon atoms,
The n A's may be the same or different. n is a number from 0 to 10 that indicates the average number of moles of alkylene oxide added. ) 3. The method according to claim 1, wherein the aqueous solution or slurry of anionic surfactant is bleached with a reducing agent and then bleached with an oxidizing agent simultaneously with the neutralization. 4. The production method according to claim 1, wherein the reducing agent is added in an amount of 0.001 to 1% by weight based on the effective content of the aqueous surfactant solution or slurry. 5. The oxidizing agent is hydrogen peroxide, and the hydrogen peroxide is added in an amount of 0.
The manufacturing method according to any one of claims 1 to 4, wherein 001 to 1% by weight is added.