JP2007002168A - Foaming agent for foam-shielding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foaming agent for a foam-shielding method, having excellent foaming power and biodegradability. <P>SOLUTION: The foaming agent for the foam-shielding method contains an α-olefinsulfonic acid salt represented by general formula (1): RCH=CH(CH<SB>2</SB>)<SB>n</SB>SO<SB>3</SB>Z (wherein, R is an 8-30C aliphatic hydrocarbon group; n is 0-5; and Z is an alkali metal and/or an alkaline earth metal) as an active ingredient. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a foaming agent for a bubble shield method.

Bubbles generated by foaming a liquid containing foaming agent are sprayed on the propulsion direction of the earth pressure shield and excavated while mixing the excavated soil and air bubbles, that is, reducing the excavation resistance of the face, reducing friction, and excavating soil transport treatment A bubble shield method with improved workability has been proposed. (For example, see Patent Document 1 and Patent Document 2)
As foaming agents used in the bubble shield method, protein foaming agents such as animal hydrolyzed proteins and surfactant foaming agents such as alkyl ether sulfates have been proposed. Moreover, in patent document 3, the foaming agent for the bubble shield construction method which used together the alkyl ether sulfate ester salt and the higher alcohol is used, and in patent document 4, it is for the bubble shield construction method which used the alkyl ether sulfate ester salt and the polyalkylene glycol together. Foaming agents have also been proposed.

JP 55-45936 A JP 57-29792 A JP 2003-314191 A JP 2003-342560 A

However, although these foaming agents are excellent in foaming power, a problem has been pointed out that the biodegradability of bubbles is not sufficient.
In the bubble shield method, a defoaming agent is added to the mixed drilling soil in which the excavated soil and air bubbles are mixed to defoam the bubbles, and then mixed with cement-based solidifying material, etc., and some of the building materials and civil engineering materials are used. Most of them are used as landfill materials for rivers and bays. When used as a landfill material, consideration for the environment must be fully taken into consideration, and from such a viewpoint, a foaming agent excellent in biodegradability is desired.

  Then, this invention is made | formed for the purpose of providing the foaming agent excellent in foaming power and biodegradability used for a bubble shield construction method.

That is, the foaming agent for the bubble shield method of the present invention is
The following general formula (1)
RCH = CH (CH ₂ ) _n SO ₃ Z (1)
(Wherein R is an aliphatic hydrocarbon group having 8 to 30 carbon atoms, n is 0 to 5, and Z is an alkali metal and / or alkaline earth metal). It is characterized by including.

  The foaming agent for the bubble shield method of the present invention has excellent foaming power and is excellent in biodegradability, and therefore can solve the problem of environmental pollution.

  The aliphatic hydrocarbon group having 8 to 30 carbon atoms represented by R in the general formula (1) may be either saturated or unsaturated, and may be linear or branched. For example, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, oleyl group, linoleyl group, linolenyl group, etc. Is mentioned. Among these, those having 8 to 20 carbon atoms are preferable from the viewpoint of foaming power, and a tetradecyl group is particularly preferable.

  N in General formula (1) shows the average mole number of a methyl group, and is the range of 0-5. When the number of added moles exceeds 5, the foaming power is deteriorated.

  Z in the general formula (1) represents an alkali metal, an alkaline earth metal, or a mixture of both, such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, radium, and these The mixture of 2 or more types of these is mentioned. Of these, sodium, potassium, magnesium, calcium, and barium are preferable, and sodium, potassium, and calcium are particularly preferable.

  Although the alpha olefin sulfonate can be produced by sulfonation of an alpha olefin, it is usually obtained as a mixture of an alkenyl sulfonate and a hydroxyalkane sulfonate, so that it can be obtained as a commercial product as a mixture thereof.

  As necessary, the foaming agent of the present invention includes an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a fatty acid, a water-soluble inorganic metal salt, a water-soluble organic solvent, and a water-soluble polymer. A dispersant may be used in combination. In particular, an anionic surfactant and a water-soluble organic solvent have an effect of improving the stability of the foaming agent aqueous solution.

Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl acid ester salt, alkyl ether sulfate ester salt and the like, and one or a mixture of two or more thereof can be used. Of these, preferred are alkyl ether sulfates.
The addition amount of the anionic surfactant is usually 0 to 100 parts by mass, preferably 10 to 50 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

It is necessary to use a cationic surfactant that does not inhibit the foaming property of the foaming agent of the present invention. For example, monoalkylammonium chloride, dialkylammonium chloride, EO-added ammonium chloride, tetramethylammonium chloride, benzyltrimethyl Examples include ammonium chloride. Monoalkyl ammonium chloride is preferred.
The addition amount of the cationic surfactant is usually 0 to 100 parts by mass, preferably 1 to 30 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

Nonionic surfactants include alkyl ether types, alkylphenol types, alkyl ester types, sorbitan ester types, sorbitan ester ether types, and the like, and one or a mixture of two or more thereof can be used. Of these, the alkyl ether type is preferred.
The addition amount of a nonionic surfactant is 0-100 mass parts normally with respect to 100 mass parts of alpha olefin sulfonates, Preferably it is 1-30 mass parts.

As the amphoteric surfactant, it is necessary to use one that does not inhibit the foaming property of the foaming agent of the present invention, and examples thereof include alanine type, imidazolinium betaine type, aminopropyl betaine type, aminodipropion type and the like. It is done. The imidazolinium betaine type is preferable.
The addition amount of the amphoteric surfactant is usually 0 to 100 parts by mass, preferably 1 to 30 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

The fatty acid may be linear or branched, natural or synthetic, saturated or unsaturated, such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, beef tallow fatty acid, Examples include oleic acid, castor hardened fatty acid, linoleic acid, palmitoleic acid, linolenic acid, and the like, and one or a mixture of two or more thereof can be used. Of these, stearic acid and palmitic acid are preferred.
The addition amount of the fatty acid is usually 0 to 50 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

Examples of water-soluble inorganic metal salts include sodium salts (sodium sulfate, sodium chloride, etc.), potassium salts (potassium sulfate, potassium chloride, etc.), magnesium salts (magnesium sulfate, magnesium chloride, etc.), calcium salts (calcium sulfate, calcium chloride, etc.). Etc.), and a mixture of one or more of these can be used. Of these, preferred are magnesium sulfate and sodium sulfate.
The addition amount of the water-soluble inorganic metal salt is usually 0 to 50 parts by mass, preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

As the water-soluble organic solvent, it is necessary to use one that does not inhibit the foaming property of the foaming agent of the present invention. For example, a cellosolve solvent (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), carbitols (ethylcarbitol, Butyl carbitol, etc.), polyoxyethylene lower alkyl ether having 3 to 10 added moles of ethylene oxide, diols (ethylene glycol, diethylene glycol, etc.), alcohols (ethyl alcohol, lauryl alcohol, etc.), etc. One or a mixture of two or more can be used. Among these, preferred are cellosolve solvents and diols, specifically butyl cellosolve, isobutyl cellosolve, ethylene glycol and diethylene glycol.
The addition amount of the water-soluble organic solvent is usually 0 to 100 parts by mass, preferably 5 to 70 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

Examples of the water-soluble polymer include cellulose derivatives (such as methyl cellulose and hydroxyethyl cellulose), polyvinyl alcohol, sodium alginate, polyvinyl ether, polyethylene glycol, and the like, and one or a mixture of two or more thereof can be used. Preferred are cellulosic derivatives.
The addition amount of the water-soluble polymer is usually 0 to 30 parts by mass, preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

It is necessary to use a dispersant that does not inhibit the foaming property of the foaming agent of the present invention. For example, naphthalenesulfonic acid, alkylnaphthalenesulfonic acid, polycarboxylic acid, polystyrenesulfonic acid, alkylamine type And alkylphenol type. Preference is given to polycarboxylic acids.
The addition amount of the dispersing agent is usually 0 to 100 parts by mass, preferably 1 to 50 parts by mass with respect to 100 parts by mass of the alpha olefin sulfonate.

When using the foaming agent of the present invention in the bubble shield method, the foaming agent is previously foamed in the form of an aqueous solution, the bubbles are sent to the excavation surface and mixed with the excavated soil, and a foaming device. It is possible to adopt a method in which the bubbles foamed using are continuously sent to the excavation surface and mixed with excavated soil.

  In both the method of foaming the foaming agent in the form of an aqueous solution in advance and the method of creating bubbles using a foaming device, when the bubbles are sent to the drilling surface and mixed with excavated soil, the foaming agent is used. As long as the foaming effect is not inhibited, various conventionally used admixtures can be used together as necessary. Examples of these admixtures include known water-soluble polymers (such as methylcellulose and sodium polyacrylate), thickeners (such as xanthan gum, guar gum, and sodium alginate), clay minerals (such as bentonite), and superabsorbent resins. be able to.

  Hereinafter, the effects of the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

[Example 1]: Biodegradability test As a foaming agent of the present invention of the general formula (1), sodium alpha olefin sulfonate (trade name "Lipolane LB-440", manufactured by Lion Corporation: RCH = CH (CH ₂ ) _n SO ₃ Na and _{RCH 2 CH (OH) (CH} 2) m SO 3 mixture of Na (the number of carbon atoms in R 14)) was used to examine the biodegradability of the foaming agent. The biodegradability test is based on the sewage test method (mainly JIS K3363 “Degradability of synthetic detergents” described in “Sewage test method, first volume”, Volume 2, Chapter 3, Section 12-3, issued by Japan Sewerage Association. The method according to “Test method” was performed. In this method, activated sludge from a sewage treatment plant is used as a microorganism source, and a basic culture solution with a test substance concentration of 30 mg / L is aerobically shaken to decompose the test substance with activated sludge, and after a predetermined number of days. This is a method for quantifying the amount of the test substance remaining in the culture medium.

<Preparation of basic culture solution>
Prepare the following reagents by dissolving them in 1 L of purified water.
Ammonium chloride (NH ₄ Cl) 3.0 g
Potassium monohydrogen phosphate (K ₂ HPO ₄ ) 1.0g
0.25 g of magnesium sulfate (MgSO ₄ )
Potassium chloride (KCl) 0.25g
Iron (II) chloride (FeCl ₂ ) 0.002g
Yeast extract 0.3g

<Preparation of activated sludge>
A test substance is added to a 1 L flask containing 500 mL of basic culture solution to a concentration of 30 mg / L, and 5 mL of activated sludge is added, followed by acclimation culture for 72 hours by shaking at 25 ± 3 ° C. The activated sludge was returned sludge of the activated sludge method that mainly treats domestic wastewater and was adjusted so that the MLSS was 5700 mg / L, and was used within 5 hours after collection.

<Biodegradability test method>
Add a basic culture solution to a 500 mL flat bottom flask containing 5 mL of activated sludge to 250 mL, add 30 mg / L of the test substance (sodium alpha olefin sulfonate), and shake at 25 ± 3 ° C. (170 rpm A part of the supernatant culture solution was collected after standing for 1 hour after the start of culture, 1 day, 3 days, 7 days, and 8 days at the start of culture, and analyzed for the remaining amount of the test substance. The test substance analysis amount before the start of culture becomes the initial test substance concentration.
As a control test, linear as standards - Sodium dodecylbenzenesulfonate (trade name "dodecene -1-LAS", produced by Wako Pure Chemical Industries, _{Ltd.: C 12 H 25 (C 6} H 4) SO 3 The same operation was performed using Na). Moreover, it carried out similarly about the system (blank test) which did not add a test substance and a reference material at all. The results are also shown in Table 1.

Ｄt：ｔ日後の生分解度（％）
Ｓo：試験開始時の試験物質又は標準物質の濃度（ｍｇ／Ｌ）
Ｂo：試験開始時の空試験値
Ｓt：ｔ日後の試験物質又は標準物質の濃度（ｍｇ／Ｌ）
Ｂt：ｔ日後の空試験値
短い日数で生分解度の数値が高まる程、生分解性が良好といえる。 <Calculation of biodegradability>
The degree of biodegradation (%) was calculated by the following formula.

Dt: degree of biodegradation after t days (%)
So: Concentration of test substance or standard substance at the start of the test (mg / L)
Bo: Blank test value at start of test St: Concentration (mg / L) of test substance or standard substance after t days
Bt: Blank test value after t days The biodegradability can be said to be better as the numerical value of biodegradability increases in a shorter number of days.

  For the reference substances in Table 1, if the biodegradation rate after 7 days of culture is 97.5% or more, it indicates that the biodegradability test is being conducted effectively. It can be confirmed that was performed effectively. From the results shown in Table 1, it can be seen that sodium alpha olefin sulfonate, which is the foaming agent of the present invention, is more biodegradable than the standard substance.

[Example 2]: Foaming test Sodium alpha olefin sulfonate (trade name “Lipolane LB-440”, manufactured by Lion Co., Ltd.) was used as an active ingredient as the foaming agent of the present invention of the general formula (1). A dilute aqueous solution prepared with water so that a certain amount of sodium alpha olefin sulfonate was 0.5% by mass and 1% by mass was prepared, foamed under the following foaming conditions, and the maximum foaming ratio was measured.
Foaming conditions Air discharge rate: 10L / min
Air pressure: 0.4 MPa
Water temperature / temperature: 20 ± 2 ℃

Foaming was performed using a foaming apparatus containing peanuts, the flow rate of the diluted aqueous solution was adjusted with a valve, the bubbles were taken into a 1 L container, the mass (g) was measured, and the expansion ratio was calculated by the following formula. The results are shown in Table 2.
Foaming magnification (times) = 1000 / bubble mass (g)
It can be said that the larger the expansion ratio, the better the foaming power of the foaming agent.

Note as a comparative example, generally polyoxyethylene alkyl ether sulfate is a foaming agent of an anionic surfactant which is commonly (trade name "San'noru NL-1430", Lion Corp.: RO (CH ₂ CH ₂ O ) using _n SO ₃ Na (12 carbon atoms R)), were subjected to the same foaming test. The results are also shown in Table 2.

  From the results of Table 2, it can be seen that sodium alpha olefin sulfonate, which is the foaming agent of the present invention, has a cell force equal to or higher than the foaming agent of the conventional anionic surfactant.

Claims (1)

The following general formula (1)
RCH = CH (CH ₂ ) _n SO ₃ Z (1)
(In the formula, R is an aliphatic hydrocarbon group having 8 to 30 carbon atoms, n is 0 to 5, and Z is an alkali metal and / or an alkaline earth metal.)
The foaming agent for a bubble shield method characterized by containing the alpha olefin sulfonate represented by these as an active ingredient.