JP2625150B2 - Manufacturing method of inner olefin sulfonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a so-called inner olefin sulfonate in which an olefinic double bond does not exist at the end of a long-chain molecule but exists only inside. About.

[Conventional technology]

DW Roberts and other reports (Tenside Deterge
nts 22 , 1985, 4 p193), it was recognized that inner olefins were difficult to be sulfonated. And
It has been thought that the reason why the inner olefin is hardly sulfonated is that 2 moles of sulfur trioxide is added to 1 mole of the olefin as a sulfonated intermediate to form carbyl sulfate.

As a means for efficiently promoting the sulfonation of inner olefins, it has been proposed to increase the ratio of sulfur trioxide to olefin.However, if the reaction is carried out under such harsh conditions, the color of the product will deteriorate. Marketability is lost.

In order to produce the inner olefin sulfonate without deteriorating the color tone, there is a method of keeping the molar ratio of sulfur trioxide to olefin low. In addition, a step of separating the remaining unreacted olefin was required (see Japanese Patent Application Laid-Open No. 54-14918 of the present applicant).

[Problems to be solved by the invention]

Therefore, an object of the present invention is to provide a method for producing an inner olefin sulfonate having a good color tone and a conversion rate to a sulfonate of 90% or more.

[Solutions to solve the problem]

The present invention relates to a process for producing an inner olefin sulfonate, which comprises a reaction product mainly comprising sultone obtained by reacting sulfur trioxide with 1 mol of a long-chain inner olefin of C _{8 to} C _18. At temperatures below 40 ° C
This is a method for producing an inner olefin sulfonate by a two-stage hydrolysis method, in which primary hydrolysis is performed with an aqueous alkali solution for up to 3 hours, and then secondary hydrolysis is performed at a temperature of 90 to 180 ° C.

It is preferable that the long-chain inner olefin of C _{8 to} C ₁₈ is contained in the starting material at least 50% or more. C _{8 to} C
Examples of ₁₈ long-chain inner olefins include tetradecene having double bonds at positions 2 to 7, hexadecene having double bonds at positions 2 to 8, and octadecene having double bonds at positions 2 to 9. As a starting material, a mixture of inner olefins in which the position of the double bond of these long-chain inner olefins is at various positions, or an inner olefin having various carbon numbers in the range of C _{8 to} C ₁₈ can be used as a starting material. There is no problem even with a mixture of olefins.

The formation reaction of sultone can be usually carried out at 25 to 40 ° C. by supplying SO ₃ gas at 1 to 20% V / V while flowing the inner olefin in a film form. The molar ratio of SO _{3 to} the inner olefin is preferably about equimolar.

The reaction product thus obtained is a mixture containing 50-90% of β-sultone, 7-30% of alkenesulfonic acid and 3-20% of γ-sultone.

In hydrolyzing this mixture, if the hydrolysis conditions are not appropriately set, the β-sultone will be decomposed into olefins and Na ₂ SO ₄ , and the conversion rate to sulfonate will be reduced. , And γ-sultone have been found to be thermally stable and cannot be converted to sulfonates unless the temperature is at least 90%, thereby completing the present invention.

Incidentally, with respect to C ₁₄ olefins having a double bond positional distribution of as shown in Table 1 below, at 38 ° C., the molar ratio of 1: 1 by reacting a SO _3, Table 2 obtained by neutralizing The primary hydrolysis of the reaction product which is a β-sultone-containing composition shown in the following at various hydrolysis temperatures and then the secondary hydrolysis at a temperature of 130 to 140 ° C. shows that the conversion to sulfonate is as follows: Table 3 shows the results.

As is apparent from this table, the conversion rate of olefins to sulfonates sharply decreases around 40 ° C., and the by-product olefins and Na ₂ SO ₄ increase.

The primary hydrolysis must be performed at a temperature of 40 ° C. or less. Preferably, the range of 30 to 35 ° C is good. Perform under agitation for 1-3 hours.

The second hydrolysis may be at a temperature of 90 to 180 ° C. and may be shorter than the first hydrolysis.

〔effect〕

The present invention can significantly improve the conversion rate of an inner olefin to a sulfonate by the two-stage hydrolysis as described above, and because the conditions are milder than the conventional hydrolysis conditions, side reactions and the like are suppressed. And good quality can be obtained.

〔Example〕

Example 1 100 g (0.363 mol) of the composition shown in Table 2 was dispersed in 130 g of water containing an equivalent amount of NaOH, and the mixture was stirred for 2 hours while maintaining the temperature at 30 to 35 ° C. The reaction was carried out while confirming that the reaction dispersion was alkaline with a phenolphthalein indicator. Thereafter, NaOH was added so as to be 10% excess of the equivalent, and the reaction was carried out at 130 to 140 ° C for 30 minutes in an autoclave. Thus, the conversion to sulfonate detected from the amount of olefin in the hydrolyzate was 95.7%.

Comparative Example 1 On the other hand, after dispersing the same composition in Table 2 in the same amount of the aqueous alkaline solution, immediately followed by stirring reaction in a water bath at 90 to 95 ° C,
Immediately after the alkali coloring due to phenolphthalein disappeared, 10% NaOH
An aqueous solution was added. After reacting at 90-95 ° C for 2 hours,
Add NaOH to make a 10% excess and at 130-140 ° C
The reaction was performed for 30 minutes. The conversion of sulfonate calculated from the amount of olefin in the hydrolyzate was 81.9%.

Example 2 An olefin having a carbon distribution and a double bond position distribution as shown in Table-4 was converted to a sulfur trioxide to olefin molar ratio.
The reaction was carried out at 1.05 to obtain a reaction product as shown in Table-5.

100 g (0.329 mol) of this reaction product was treated in the same manner as in Example 1, and the conversion to sulfonate calculated from the amount of olefin in the hydrolyzate was 95.8%.

Example 3 Trans 2-Octene was prepared in Dioxane-
After reacting with the sulfur trioxide complex at a molar ratio of SO _{3 to} olefin of 0.5, purification was carried out to obtain a reaction product as shown in Table-6.

Approximately 50 mg of this reaction product is 2 mg in an aqueous solution containing 100 mg of NaOH
Dispersed in a glass sealed tube at room temperature (about 25 ° C) for 3 hours,
The mixture was hydrolyzed at 90 to 95 ° C for 1 hour while occasionally shaking the sealed tube. Almost no olefin was newly formed by this hydrolysis reaction, and more than 90% was converted to sulfonate by NMR and HPLC analysis.

Comparative Example 2 On the other hand, without reacting the same sample at room temperature,
After reacting for 1 hour at 95 ° C, the newly formed olefin is
At 52%, the conversion to sulfonates was less than half.

Claims (1)

(57) [Claims] 1. A reaction product of an inner olefin containing at least 50% by weight of a long-chain inner olefin of C _{8 to} C ₁₈ and sulfur trioxide is neutralized at a temperature of 40 ° C. or lower, and further treated with an aqueous alkaline solution. A method for producing an inner olefin sulfonate, comprising performing primary hydrolysis at a temperature of not higher than 1 ° C for 1 to 3 hours, and then performing secondary hydrolysis at a temperature of 90 to 180 ° C.