JPS62149330A - dispersant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a dispersant, and particularly to a dispersant that can disperse various fine powders in water with extremely good dispersibility.

[Prior Art] In order to disperse solid particles in a liquid and create a stable suspension, a dispersant is generally added and used. For example, in various main treatment facilities, suspended solids in circulating water are Dispersants are widely used for the purpose of preventing sludge circulation, such as when maintaining a state in which sedimentation is difficult using a dispersant and discharging it outside the blower system for treatment.

Conventional dispersants include various surfactants, low molecular weight polycarboxylic acids, and lignin sulfonates.

Formalin condensates of naphthalene sulfonates and the like are used, and are used appropriately depending on the object to be treated. Most of these dispersants are adsorbed to fine particles in water,
Stable dispersion is achieved by utilizing electrostatic repulsion between particles due to negative charges of carboxylic acid ions or sulfonic acid ions in dispersant molecules on the surface of each particle.

[Problems to be solved by the invention] Generally, in order to uniformly and stably disperse fine powder in water, the finer the particles, the smaller the difference in density between the particles and water, and the higher the viscosity of the water. Of these factors, the size of the particles is determined by the object to be treated, and the difference in density between particles and water cannot usually be changed. On the other hand, the viscosity of water can be increased by adding water-soluble polymers.

For this reason, when the target to be treated is a particularly dense fine powder, a highly viscous substance such as a water-soluble polymer is used in conjunction with a general dispersant, but conventional dispersants do not provide sufficient dispersion. No results have been obtained, and the development of superior dispersants is considered an extremely important issue.

[Means for Solving the Problems] The present invention was completed as a result of intensive studies on dispersants having excellent effects in view of the above-mentioned conventional circumstances. The dispersant of the present invention is.

It is a surfactant produced by bacteria that succumb to Acinetobacterium, and hydroxy fatty acids having 10 to 18 carbon atoms are bonded to a skeleton consisting of galactosamine and amide/uronic acid to form esters and amides, or It is characterized by containing telosatucharide, and further containing a synthetic surfactant and/or a synthetic polymer dispersant, if necessary.

The present invention will be explained in detail below.

The dispersant of the present invention has a structure in which a hydroxy fatty acid having 10 to 18 carbon atoms is bonded to a skeleton composed of galactosamine and aminouronic acid produced by a bacterium belonging to the Acinetobacter species to form an ester and an amide. (hereinafter simply referred to as "lipopolyheterosaccharide").

The dispersant of the present invention shows a sufficiently excellent dispersion effect even when the lipopolyheterosaccharide is used alone, but depending on the purpose, it can be used in combination with other synthetic polymer dispersants and/or synthetic surfactants. By taking advantage of the excellent features of each and compensating for each other's shortcomings, it is possible to exhibit a significantly superior dispersion effect.

In this case, the synthetic molecular dispersant 1 is not particularly limited, but dispersants such as low molecular weight polycarboxylate salts, lignin sulfonate salts, formalin condensates of naphthalene sulfonate salts, etc. are generally used. Other dispersants include homo- or copolymers of acrylic acid, methacrylic acid, maleic acid, and itaconic acid, specifically polyacrylic acid,
Acrylic acid-allyl alcohol, maleic acid-isobutylene, acrylic acid-hydroxyethyl methacrylate, etc. can also be used.

In addition, anionic surfactants are used as synthetic surfactants.

Alternatively, a nonionic surfactant can be used. Examples of anionic surfactants include sodium laurate,
Examples include carboxylic acid salts such as sodium oleate; sulfuric acid ester salts such as higher alcohol sulfuric ester salts and higher alkyl ether sulfuric ester salts; sulfonic acid salts such as ABS and alkylnaphthalene sulfonates; and phosphoric acid ester salts. In addition, nonionic surfactants include polyethylene glyco-II/Jj such as higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, and polyhydric alcohol fatty acid ester ethylene oxide adducts.
In the present invention, examples include polyhydric alcohol type alcohols such as fatty ILh acid ester of glycerol, fatty acid ester of pentaerythritol, and fatty acid ester of sucrose.

It is particularly suitable to use nonionic surfactants.

When such synthetic polymer dispersants and/or synthetic surfactants are used together, the ratio is the weight ratio of lipopolyheterosaccharide to the total amount of synthetic polymer dispersants and/or synthetic surfactants. , l:0.5 to l:5 or so.

The lipopolyheterosaccharide according to the present invention is usually in the form of a powder, but when used, 2rfLQ
% or less is preferable.

Also, when mixing with other dispersants and surfactants.

If the other dispersant is in powder form, it is sufficient to simply mix it with lipopolyheterosaccharide powder in an appropriate ratio, but if it is in paste or liquid form, such as a nonionic surfactant, add water. In addition, the mixture with lipopolyheterosaccharide powder was tested using a B-type viscometer (3 Or pm, 20°C).
It is desirable to adjust it so that it is 150CP or less.

The lipopolyheterosaccharide according to the present invention includes emultins disclosed in JP-A-55-112201.

The lipopolyheterosaccharide used in the present invention has a molecular weight of several hundred thousand or more, usually about one million.

In the lipopolyheterosaccharide used in the present invention, the skeleton consisting of galactosamine and aminouronic acid (
The proportion of the hydroxy fatty acid having 10 to 18 carbon atoms bonded to the (hereinafter sometimes referred to as "main skeleton") is preferably 5% by weight or more, particularly about 5 to 19% by weight of the lipopolyheterosaccharide.

As the hydroxy fatty acid that binds to the main skeleton, 2-hydroxydodecanoic acid and 3-hydroxydodecanoic acid are preferable, and especially among the hydroxy fatty acids that bind to the main skeleton, 5
It is preferable that 0% by weight or more, especially 50 to 70% by weight, be 2-hydroxydodecanoic acid and 3-hydroxydodecanoic acid, and the content ratio of 2-hydroxydodecanoic acid and 3-hydroxydodecanoic acid is 1:4 to 1: 1. Especially 1:
It is preferable that it is 4-1:2. Also.

Such hydroxy fatty acids have an average equivalent weight of about 200
It is preferable that it is about 230 to 230.

In addition, the ratio of galactosamine and aminouronic acid forming the main skeleton of lipopolyheterosaccharide to the hydroxy fatty acid ester and amide bonded to the main skeleton is 20 to 35% by weight of galactosamine and 30 to 3% by weight of aminouronic acid.
Preferably, the content is 5% by weight, and 7 to 19% by weight of fatty acid esters and fatty acid amides.

This is what Bobori Heterosaccharide looks like.

For example, it is produced by bacteria belonging to Acinetobacter species ATCC31012 and its mutants by the method disclosed in JP-A-55-112201.

During the exponential growth phase of this Acinetobacter species and its mutants, the cells are primarily 0.9-1.2 x 1.5-3. OI
Appearing as irregular short rods of Lm, the cells form V-shaped pairs showing snapping divisions. The rod may be slightly curved or swollen. In stationary phase culture.

Coccoid cells with a diameter of approximately 1.27 Lm
cell), the cocci are Duram positive and the rods are Duram negative.

It is an agar colony, round with a diameter of 5.0 mm or less, glossy and smooth. Gelatin is liquefied, starch is not hydrolyzed, indole and hydrogen peroxide are not generated, and nitrite is produced from nitrate only when cells are grown in citrate medium containing potassium nitrate. It does not produce urease, is positive for catalase, and is aerobic. With the hemolysis phenomenon of rabbit thrombi, citrate acts as the sole carbon and energy source. There is no acid production from glucose, cellulose, maltose, lactose, rhamnose, sucrose or mannitol, and the optimum temperature is 30
~35°C.

The lipopolyheterosaccharide according to the present invention is
l: @Acinetobacter Contact the inU delivered to Acinetobacter with a growth-maintaining amount of ethanol or an aqueous fermentation medium containing one or more fat 11/i acid salts, and add an additional amount of ethanol or one kind to maintain growth. After growing the cells aerobically in the fermentation medium for a sufficient period of time to produce lipopolyheterosaccharides with the addition of fatty acid salts, substantially all of the bacterial cell mass is removed from the culture. It is easily produced by separating it from the culture medium.

The fermentation medium and suitable conditions for fermentation treatment will be explained below.

■ Carbon source The carbon source is ethanol or one or more fatty acid salts,
In this case, the fatty acid salt is decane salt (capric acid)
, anabolic saturated fatty acids such as dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid) and octadecanoic acid (stearic acid),
Examples include unsaturated fatty acids having a carbon number lθ to 18, including monoethanoid and dietanoid fatty acids, and hydroxy6-substituted fatty acids such as 2-hydroxydodecanoic acid, 3-hydroxydodecanoic acid, and 12-hydroxyoleic acid (lysyllic acid). Additionally, mixed fatty acids of saponified derivatives of lard, soybean oil, peanut oil, cottonseed oil, safflower oil, coconut oil, castor oil, coconut oil and various fish or marine mammal oils can be used.

In particular, it is optimal that one fermentation medium contains about 1 to 5% by weight of one or more fatty acid salts.

(■ Additional nutrient source In addition to the above carbon source, the fermentation medium contains additional nutrient sources such as
Contains a growth-sustaining amount of at least one assimilable nitrogen-containing compound and a growth-sustaining amount of one or more assimilable phosphorus-containing compounds.

Suitable sources of available nitrogen include ammonium salts such as ammonium sulfate or ammonium chloride, nitrates such as ammonium nitrate or sodium nitrate, and other organic sources such as urea or soy flour. Further, suitable sources of phosphorus include dibasic potassium phosphate, -basic potassium phosphate, and the like.

■ Divalent cations In the present invention, when pure water or distilled water is used as water for preparing an aqueous fermentation medium, it is preferable to add one or more divalent cations to the fermentation medium.
Examples of divalent cations include magnesium ions, calcium ions, manganese ions, etc., and their concentration in the medium is about 1 to 100 mmol, preferably 5 to 100 mmol.
Preferably it is 40 mmol.

■ Fermentation processing conditions The conditions for maximum growth by fermentation are as follows.

(2) Aeration When using a 601 stirred fermenter filled with fermentation medium, it is preferable to pass air through the fermentation medium from about 10 to 601/min.

(Depending on the type of fermenter used, the medium needs to be stirred or circulated within the fermenter to maximize the diffusion of oxygen to the agitated cell population.) When using a stirred fermentation device, generally 1
It is preferable to stir the medium at a rotation speed of 00 to 40 rpm.

@Defoaming Fermentation can cause foaming problems.

For this reason, when using a 60-liter stirring device filled with one fermentation medium, it is preferable to intermittently add a silicone antifoaming agent diluted to 1:8.

The lipopolyheterosaccharide thus obtained is extracted from the culture medium with a water-immiscible organic solvent after the bacterial cell mass is separated from the culture medium by filtration, centrifugal filtration or decantation.

In this case, hebutane is used as the organic solvent, and it is preferable that the extracted or boboliheterosaccharide is further subjected to dialysis to remove impurities.

A method may also be adopted in which an ammonium salt such as ammonium sulfate is added to the medium to precipitate lipopolyheterosaccharide, the precipitate is extracted and recovered with ether, and further purified by dialysis.

Note that the dispersant of the present invention may contain other commonly used builders, etc., depending on the purpose.

[Function] The lipopolyheterosaccharide used in the present invention mainly has 12 carbon atoms, and has a hydrophobic part due to a long chain fatty acid moiety, and a woody part due to a carboxyl group, water m, and 2Jli coexist. , itself has surface activity.

In addition, since the molecular weight is usually about 1 million, which is much larger than that of conventional dispersants, it has an extremely high viscosity, as shown in Figure 1. This is a graph showing the relationship between lipopolyheterosaccharide concentration and viscosity when measured with a B-type viscometer (20 ° C., 30 rpm).) Based on this,
This lipopolyheterosaccharide is.

(2) Because of its high molecular weight, when adsorbed on the surface of fine powder particles, it occupies approximately 1000 times the area per molecule compared to ordinary surfactants, creating a huge barrier.

(Model) Direct the negatively charged carboxyl group toward the liquid side and apply static repulsion between each particle to disperse each particle in the liquid.

■ Even if the negative charges of other particles approach, due to their high molecular weight, they do not repel the negative charges of neighboring particles and move on the particle surface.

Because it has the following characteristics, it can exhibit excellent dispersion effects.

In addition, due to its high viscosity, when used in combination with other synthetic surfactants or dispersants, the synergistic effects enable more stable dispersion of particles.

[Examples] The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Example 1 Add the dispersant aqueous solution shown in Table 1 to 0.05 g of reagent grade calcium carbonate powder to make a total volume of 50 mJ1, shake vigorously 30 times in a 50 mM colorimetric tube, and then let it settle. Depth of calcium carbonate-water interface (depth of aqueous phase)
The changes were observed and measured. The results are shown in Table 1. (Note that the pressure between the scales of the colorimeter tube gl131mm corresponds to 50mM.) Example 2 Reagent special grade red iron oxide (α
A dispersion test was conducted in the same manner as in Example 1 using 0.05 g of Fe203) and an aqueous dispersant solution shown in Table 2. The results are shown in Table 2.

Example 3 The dispersant aqueous solution shown in Table 3 was added to 0.5 g of carbon black to make a total volume of 100 mJl each, which was vigorously shaken 30 times in a 100 m colorimeter tube and then left to stand. Observe changes in water phase (depth);
It was measured. The results are shown in Table 3. In Table 3, only in the case of blank No. 15, the depth of the interface was measured after 2 minutes, 4 minutes, and 6 minutes.

From Tables 1 to 3, it is clear that the dispersant of the present invention provides excellent dispersion effects, and that the dispersion effects are maintained stably for a long period of time, preventing particles once dispersed from agglomerating again. It is clear that

1st table tree 1: ni = lipopolyheterosaccharide book 2: A = sodium polyacrylate (molecular weight approximately 5,000) 2nd table tree 1: ni = lipopolyheterosaccharide book 2: A = polyacrylic acid Soda (molecular weight approximately 5,000) Table 3 Tree 1: To = Lipopolyheterosaccharide Tree 22 B = Sodium dioctyl sulfosuccinate Tree 3: B: To = l: l (weight ratio) [Effects of the invention] Above As described in detail, the dispersant of the present invention contains lipopolyheterosaccharide, or a synthetic surfactant and/or a synthetic polymer dispersant, and the dispersant of the present invention contains lipopolyheterosaccharide or a synthetic surfactant and/or a synthetic polymer dispersant. Due to the excellent dispersion effect or dispersion assisting effect of polyheterosaccharide, it is possible to obtain a stable dispersion by effectively dispersing various fine particles.

Therefore, the dispersant of the present invention is extremely useful in the field of water treatment for various aqueous systems.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the viscosity and the concentration of lipopolyheterosaccharide in an aqueous lipopolyheterosaccharide solution. Agent Patent Attorney Go Shigeno Concentration Aspirations'/, ) Procedural amendment January 24, 1985 l Indication of the case 1985 Patent Application No. 291738 2 Name of the invention Dispersant 3 Person making the amendment Related Patent applicant name (106) Kurita Industries Co., Ltd. 4 Agent address 4-8-19 Akasaka, Minato-ku, Tokyo 107
Akasaka Omotemachi Building No. 502 Voluntary Issue 6 Column for detailed explanation of the invention in the specification subject to amendment. 7. Contents of the amendment (1) In the 6th line of page 7 of the specification, the phrase ``r or more than several hundred thousand yen'' is corrected to 1. that's all

Claims (2)

[Claims] (1) A surfactant produced by a bacterium belonging to the Acinetobacter species, which is a lipopolyheterosaccharide in which hydroxy fatty acids having 10 to 18 carbon atoms are bonded to a skeleton consisting of galactosamine and aminouronic acid to form esters and amides. A dispersant characterized by containing lard. (2) The dispersant according to claim 1, which contains lipopolyheterosaccharide and a synthetic surfactant and/or a synthetic polymer dispersant.