JP2736746B2 - Dispersant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispersant, and more particularly, to a dispersant containing a water-soluble modified polyvinyl alcohol.

[0002] The dispersant of the present invention has excellent dispersing performance, is useful as a general dispersant, and is one of the dispersants.
It is useful as a seed mud conditioner for drilling. In addition, it can be used for various uses such as additives for paper, chemicals for fibers, and chemicals for civil engineering.

[0003]

2. Description of the Related Art Conventionally, as a mud regulator for drilling used as an additive for mud used in petroleum drilling or civil engineering, for example, carboxymethyl cellulose (CMC), starch or the same is used. Derivatives, sodium polyacrylate, polyacrylamide partial hydrolyzate, or maleic anhydride copolymer (eg, maleic anhydride and styrene copolymer)
And the like.

[0004] These drugs have pendant carboxyl groups which are anionic in water and are adsorbed on clay particles used as a thickener for muddy water to charge the surface of the clay particles anionic. Let it. Then, the clay particles are dispersed by the electric repulsion.

However, such a conventional muddy water modifier has poor salt and heat resistance, so that the excavation depth is increased, the formation temperature is increased, and a high concentration of salt (particularly divalent metal ions) is contained. When contaminated by the formation water, the viscosity is easily lost due to the reaction between the divalent metal ion and the carboxyl group together with the chemical deterioration, and the dehydration reduction performance, which is an important function as a muddy water regulator, is reduced.

[0006] That is, in the case of a conventionally used mud regulator, for example, starch, about 100 to 12
Degradation accelerates at 0 ° C, and CMC and synthetic polymers
At 0 ° C., the deterioration becomes significant. Further, since the divalent metal ion binds to the carboxyl group of the polymer and the polymer loses viscosity, the deterioration becomes more remarkable in the salt water system containing the divalent metal ion.

It is an object of the present invention to provide a dispersant containing a novel water-soluble polymer compound which is excellent in dispersing performance, resistant to divalent metal ions and excellent in reducing dehydration of muddy water (particularly, Dispersant for inorganic substance or powdered biocide) and a drilling mud conditioner which is a kind of dispersant.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have determined that sulfonic acid-modified polyvinyl alcohol functions as a dispersant or a muddy water conditioner for drilling, which is a kind of dispersant. Found and led to the present invention.

The dispersant of the present invention comprises the following structural units (I) and (II), wherein the content of (I) is 0.3 to 2.7 milligram equivalent / g in colloid equivalent value, It comprises a modified polyvinyl alcohol having a molecular weight of 3,000 to 400,000.

Embedded image (In the formula, M represents H, an alkali metal, ammonium, alkyl ammonium, or alkanol ammonium.)

Embedded image

This dispersant can be used as a muddy water conditioner for drilling.

The ratio (content) of the structural unit (I) in the modified polyvinyl alcohol according to the present invention is 0.3 to 2.7 milligram equivalent in 1 g of the polymer in colloid equivalent value. When the ratio of the structural unit (I) is less than 0.3 milligram equivalent / g, the anionicity of the polymer is insufficient, the dispersing performance is insufficient, and aggregation tends to occur. If it exceeds 2.7 milligram equivalent / g, production is difficult. The ratio of the structural unit (I) is preferably from 0.9 to 2.7 milligram equivalent / g. Here, the colloid equivalent value of 0.3 to 2.
7 milligram equivalents / g correspond to 1.4-31.1 mol%, and 0.9-2.7 milligram equivalents / g correspond to 5.0-3.
1.1 mol%.

The structural unit (II) basically occupies all or most of the remainder except for the structural unit (I).

In addition to the structural units (I) and (II), the following structural unit (III) may be contained for convenience of production, but does not particularly affect the performance.

Embedded image

If the weight average molecular weight is less than 3,000 or more than 400,000, it is difficult to produce them.

In the modified polyvinyl alcohol according to the present invention, the viscosity of a 4% aqueous solution of NaCl having a polymer concentration of 4% by weight is measured using a Brookfield viscometer by a rotor N.
o. 1 at 60 rpm at 25 ° C., 3 to 50 mPa
-It is s.

The modified polyvinyl alcohol according to the present invention is obtained by adding saponified polyvinyl acetate to 2-acrylamido-2-methylpropane-3-sulfone in the presence of an alkali, for example, as shown in the following formula. It is obtained by a Michael addition reaction of sodium acid (AMPS-Na).

Embedded image

Incidentally, potassium 2-acrylamido-2-methylpropane-3-sulfonate (AMPS-K) may be used instead of AMPS-Na. Also, AMPS
After the addition of -Na, the pH is adjusted to neutral or acidic with a mineral acid, and ammonia, alkylamines, and alkanolamines are added. In the structural unit (I), M is ammonium, alkylammonium, or alkanolammonium. Is converted to

The amount of AMPS added to the modified polyvinyl alcohol according to the present invention can be determined from a colloid equivalent value measured by a colloid titration method. Colloid titration is a method commonly used to measure the anion equivalent value of a polymer. 2-methylglycol chitosan is added to an aqueous solution of a polymer, and after addition, titration is performed with an aqueous solution of potassium potassium sulfate of polyvinyl alcohol. Is the way. Also,
Regarding the identification of the modified polyvinyl alcohol according to the present invention, IR (infrared absorption analysis), NMR (nuclear magnetic resonance analysis)
The AMPS addition amount can also be quantified by determining the nitrogen content by the Kjeldahl method.

The degree of polymerization of the base polyvinyl alcohol used for the modification is from 50 to 10,000, preferably from 200 to 3,500. Regarding the degree of saponification, since hydrolysis is performed by an alkali, even if an acetate group remains, most of the saponification is ultimately saponified, and is not particularly limited. It is preferable to use a completely saponified product.

As the alkali for the Michael addition reaction catalyst, triethylamine and the like can be suitably used in addition to KOH and NaOH.

In the Michael reaction, usually 0.5 to 20 mol% of an alkali with respect to the hydroxyl group of polyvinyl alcohol, a lower alcohol such as methanol and isopropyl alcohol, a solvent such as water, dimethyl sulfoxide and dimethylformamide are used. A polyvinyl alcohol solution of 1 to 50% by weight is prepared, and 10 to 200 mol% of 2-acrylamide-
2-methylpropane-3-sulfonate monomer and, if necessary, a small amount of a polymerization inhibitor such as hydroquinone or hydroquinone monomethyl ether are added, and
React at a temperature of 0 ° C. for 10 minutes to 20 hours.

The reaction amount of 2-acrylamido-2-methylpropane-3-sulfonate in the Michael reaction is as follows:
It can be arbitrarily adjusted by selecting appropriate reaction conditions, but the colloid equivalent value in 1 g of the product polymer may be adjusted to 0.3 to 2.7 milligram equivalent (meq / g).

In order to obtain various forms of final products, the concentration of the reaction solution in the Michael reaction may be changed,
For example, when the target is a powder form, it is desirable to carry out the reaction at a concentration as high as possible to facilitate drying.

After the reaction, excess acetone, methanol, n
-It can be taken out by precipitating the reaction product using a solvent such as propanol or isopropyl alcohol.

The dispersant of the present invention is particularly useful as a dispersant for inorganic substances and powdered biocides. Moreover, the mud conditioner for drilling is useful as a mud conditioner for civil engineering drilling and oil drilling.

The muddy water modifier for drilling of the present invention is used in an amount of 0.01 to 5% by weight, preferably 0.1 to 4% by weight, based on the muddy water. In order to obtain the muddy water for excavation using the modifier of the present invention, the muddy water may be adjusted in accordance with a conventional method. Or after dispersing in salt water, using a dispersion stirrer such as homodisper,
Add a regulator to make a uniform dispersion.

When it is necessary to adjust the pH of the muddy water, the pH is adjusted by adding an aqueous solution of an alkali such as sodium hydroxide to the muddy water obtained as described above.

It is also possible to use the muddy water modifier for drilling of the present invention together with sodium hexametaphosphate, sodium tripolyphosphate, sodium ligninsulfonate, carboxymethylcellulose, sodium alginate and other known modifiers.

The muddy water modifier for drilling of the present invention exhibits salt and heat resistance, and exhibits excellent dispersion performance and dehydration reduction performance.
The mechanism of action is considered as follows.

Regarding the function of dispersing the drilling mud,
A low molecular weight high anionic polymer having a carboxyl group such as sodium polyacrylate is effective. The carboxyl groups of these polymers are anionically charged in water, adsorb on the surface of the cationically charged clay particles and convert the charge to anionic, and the anion charge and the anion charge of the polymer repel. It is said to disperse clay particles. In the muddy water preparation for drilling of the present invention, a sulfonic acid group works in place of a carboxyl group to disperse clay particles.

When divalent metal ions are mixed into muddy water in which clay particles are dispersed using a conventional polymer having a carboxyl group, the divalent metal ion is bonded to the carboxyl group of the polymer, and the water solubility is reduced. The performance and dehydration reduction performance decrease. On the other hand, the modified polyvinyl alcohol according to the present invention has, in addition to the sulfonic acid group, a hydroxyl group which does not react with a divalent metal ion, and can maintain water solubility, and can also maintain dispersing performance and dehydration reducing performance. And
This performance can be exhibited even at high temperatures.

[0032]

Next, the present invention will be described specifically with reference to examples.

Example 1 In a 4-liter horizontal blender, 300 g of powdered polyvinyl alcohol (PVA-117 manufactured by Kuraray Co., Ltd.) having a saponification degree of 95% or more and a polymerization degree of 1,700, and 30% N
180 g of an aOH aqueous solution was added, and the mixture was stirred at 25 ° C. for 2 hours to homogenize. Next, 940 g of a 50% AMPS-Na aqueous solution was added, the temperature was raised to 70 ° C., and a stirring reaction was performed for 6 hours. Next, a 5-fold amount of isopropyl alcohol was added, and the mixture was purified, dehydrated, and dried at 105 ° C.

When the colloid equivalent value of the obtained polymer was measured, it was 1.4 milligram equivalent / g.

FIG. 1 shows the IR spectrum of this polymer. The sulfonic acid absorption in the AMPS unit is 1217.
Located cm ^-1 and 1043 ^-1, the absorption of an amide group is in the 1657cm ^-1. FIG. 2 shows the NMR spectrum. From this spectrum, the amount of AMPS added was about 8.8 mol%, which almost coincided with the result obtained by the colloid titration method.

The weight average molecular weight of the polymer was determined by gel permeation chromatography (GPC) to be 130,
000. Using a 0.1 N NaCl aqueous solution as an eluent at 40 ° C., four columns manufactured by Tosoh Corporation (TS
Kgel G2500PW, G3000PW, G400
0PW, G5000PW) were connected in series.
Detection was performed by RI. PEG as standard for molecular weight
-A calibration curve was prepared using PEOs.

The viscosity of a 4% aqueous solution of NaCl having a polymer concentration of 4% by weight was 14.0 mPa · s. Viscosity was measured using a Brookfield viscometer using a rotor N
o. 1 at 60 rpm and 25 ° C.

Example 2 In a 4 liter horizontal blender, 300 g of powdered polyvinyl alcohol (PVA-117 manufactured by Kuraray Co., Ltd.) having a saponification degree of 95% or more and a polymerization degree of 1,700, and 30% N
180 g of an aOH aqueous solution was added, and the mixture was stirred at 25 ° C. for 2 hours to homogenize. Next, after adding 630 g of a 50% AMPS-Na aqueous solution, the temperature was raised to 70 ° C., and stirring was continued for 6 hours. After completion of the reaction, the mixture was cooled, and a polymer was precipitated with isopropyl alcohol, separated and dried.

When the colloid equivalent value of the obtained polymer was measured, it was 0.7 milligram equivalent / g. GP
The weight average molecular weight by C was 120,000. The viscosity of a 4% aqueous solution of NaCl having a polymer concentration of 4% by weight was 13.0 mPa · s.

Example 3 In a 4 liter horizontal blender, 300 g of powdered polyvinyl alcohol (PVA-117 manufactured by Kuraray Co., Ltd.) having a saponification degree of 95% or more and a polymerization degree of 1,700 and 30% N
180 g of an aOH aqueous solution was added, and the mixture was stirred at 25 ° C. for 2 hours to homogenize. Then, after adding 1,100 g of 50% AMPS-Na aqueous solution, the temperature was raised to 70 ° C.
Stirring was continued for hours. After completion of the reaction, the mixture was cooled, and a polymer was precipitated with isopropyl alcohol, separated and dried.

When the colloid equivalent value of the obtained polymer was measured, it was 2.3 milligram equivalent / g. GP
The weight average molecular weight by C was 110,000. The viscosity of a 4% aqueous solution of NaCl having a polymer concentration of 4% by weight was 12.0 mPa · s.

Example 4 In a 4-liter horizontal blender, 300 g of powdered polyvinyl alcohol (PVA-105 manufactured by Kuraray Co., Ltd.) having a degree of saponification of 95% or more and a degree of polymerization of 500, and 30% NaOH
180 g of the aqueous solution was added, and the mixture was stirred at 25 ° C. for 2 hours to homogenize. Next, a 50% AMPS-Na aqueous solution 9
40 g was added, the temperature was raised to 70 ° C., and a stirring reaction was performed for 6 hours. Then, add 5 times the amount of isopropyl alcohol,
Purification, dehydration and drying at 105 ° C.

When the colloid equivalent value of the obtained polymer was measured, it was 1.5 milligram equivalent / g. GP
The weight average molecular weight by C was 40,000. The viscosity of a 4% aqueous solution of NaCl having a polymer concentration of 4% by weight was 5.0 mPa · s.

Example 5 In a 4 liter horizontal blender, 300 g of powdered polyvinyl alcohol (PVA-124 manufactured by Kuraray Co., Ltd.) having a saponification degree of 95% or more and a polymerization degree of 2,400 and 30% N
180 g of an aOH aqueous solution was added, and the mixture was stirred at 25 ° C. for 2 hours to homogenize. Next, 940 g of a 50% AMPS-Na aqueous solution was added, the temperature was raised to 70 ° C., and a stirring reaction was performed for 6 hours. Next, a 5-fold amount of isopropyl alcohol was added, and the mixture was purified, dehydrated, and dried at 105 ° C.

When the colloid equivalent value of the obtained polymer was measured, it was 1.3 milligram equivalent / g. GP
The weight average molecular weight by C was 230,000. The viscosity of a 4% aqueous NaCl solution having a polymer concentration of 4% by weight was 30.0 mPa · s.

Comparative Example 1 Powdered polyvinyl alcohol 3 having a saponification degree of 95% or more and a polymerization degree of 1,700 was placed in a 4-liter horizontal blender.
00 g and 180 g of a 30% NaOH aqueous solution were added, and the mixture was stirred at room temperature for 2 hours to homogenize. Then 50
310 g of a% AMPS-Na aqueous solution was added, the temperature was raised to 70 ° C, and the mixture was stirred and reacted for 6 hours. Next, a 5-fold amount of isopropyl alcohol was added, and the mixture was purified, dehydrated, and dried at 105 ° C.

When the colloid equivalent value of the obtained polymer was measured, it was 0.1 milligram equivalent / g. GP
The weight average molecular weight by C was 110,000. The viscosity of a 4% aqueous solution of NaCl having a polymer concentration of 4% by weight was 7.0 mPa · s.

Examples 6 to 10 and Comparative Examples 2 to 4 After adding and dispersing 42 g of bentonite to 700 ml of water, 20 g of each of the polymers of Examples 1 to 5, the polymer of Comparative Example 1, and the low viscosity CMC were added. The mixture was stirred to dissolve uniformly. Further, 180 g of NaCl and 21 g of CaCl ₂ were added.
g was added and uniformly dissolved. After allowing to stand overnight, the mixture was stirred again to dissolve the sample uniformly, and the pH was adjusted to 9.5 to 11.0 with sodium hydroxide. Next, the muddy water was divided into two parts, and for one muddy water, the viscosity was measured and then a dehydration test was performed to measure the amount of dewatering. The other mud was placed in a heat-resistant container, heated and stirred at 180 ° C. for 16 hours, then cooled to room temperature, and the viscosity and dehydration amount were measured. The results are shown in Table 1.

The measurement of the viscosity was carried out by using a fan VG meter.

The dehydration test was carried out using a dehydration test apparatus.
350 ml of muddy water was filtered and dehydrated under a pressure of kg / cm ² , and the amount of dehydration after 30 minutes was measured. The smaller the amount of dehydration, the better the mud.

[0051]

[Table 1]

Examples 11 to 15 and Comparative Example 5 A dispersion test of aluminum hydroxide, one of the inorganic pigments used for papermaking, was carried out.

In a 1 liter beaker, 100 g of water containing 0.4% by weight of the polymer of Examples 1 to 5 based on aluminum hydroxide was added, and aluminum hydroxide fine powder (average particle size: 0.8 μm) was stirred. 300 g were added and dispersed. Then, high-speed stirring is performed for 3 minutes (4,000 rpm).
It was dispersed to obtain an aqueous dispersion having a solid concentration of 75%. The viscosity of the aqueous dispersion immediately after production and the viscosity after standing at 25 ° C. for one week were measured by a BM type viscometer, and compared with sodium polyacrylate (molecular weight 10,000) to obtain a dispersion performance. Was evaluated. Table 2 shows the results.

[0054]

[Table 2]

Examples 16 to 20, Comparative Example 6 A predetermined amount of a dispersant (the polymer of Examples 1 to 5, sodium polyacrylate) and water were added and uniformly stirred and dissolved, and then light calcium carbonate (Maruo Calcium Co., Ltd.) Was added so as to have a content of 60% by weight. Then, after stirring with a homomixer for 10 minutes, the mixture was stirred at 25 ° C. with a BM type viscometer.
The viscosity was measured with. Table 3 shows the results.

[0056]

[Table 3]

Examples 21 to 25 and Comparative Example 7 Performance evaluation tests were carried out using the polymers of Examples 1 to 5 as dispersants for powdered biocides.

70 g of o, o-dimethyl-s- (N-methylcarbamoylmethyl) dithiophosphate (dimethoate) used as an insecticide, clay 1 as a carrier
After mixing 3 g, 7 g of white carbon, and 10 g of the polymer of Examples 1 to 5 as a dispersant, the mixture was finely pulverized with a ball mill to 300 mesh or less to obtain a biocidal wettable powder composition. The hydratability, self-dispersibility and suspension stability of these compositions were measured and evaluated in comparison with an alkylnaphthalenesulfonic acid Na-formalin condensate (molecular weight 13,000). Table 4 shows the results.

For hydration and self-dispersibility, 100 m
1 ml of cylinder was charged with 100 ml of 10-degree hard water, and 1 g of the composition was gently added thereto for evaluation. The hydratability is evaluated by the time until the composition sinks, and the shorter the time, the better. The self-dispersibility is an evaluation of the dispersibility after the composition is put into water, and is evaluated in the following three stages. A: Disperse uniformly at the same time as charging. B: Not dispersed immediately after charging, 1 /
Start dispersing after two or more sinks. C: flocs or agglomerates on the water surface. Of these, A has the best self-dispersibility.

The suspension stability was evaluated by determining the ratio of the amount of suspension in the following manner. First, 1.0 g of the sample composition
Into a 200 ml stoppered cylinder,
200 ml of 10 ° C. hard water was added and sufficiently mixed and dispersed. Next, after inverting and stirring 20 times for 30 seconds, 5
After standing for 20 minutes, 20 ml was sampled from the center of the cylinder with a whole pipette, filtered through a glass filter, and dried. The obtained solid content was measured, and a suspension amount ratio was calculated from the solid content and the collected amount of the sample composition according to the following equation. The larger the suspension amount ratio, the better the suspension stability. Suspension amount ratio (%) = ｛solid content / (sample collection amount × (20 /
200))｝ × 100

[0061]

[Table 4]

[0062]

The dispersant of the present invention has excellent dispersion performance.
Further, the muddy water conditioning agent for excavation of the present invention has resistance to divalent metal ions and is excellent in mud water dewatering reduction performance.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of the modified polyvinyl alcohol obtained in Example 1.

FIG. 2 is an NMR spectrum of the modified polyvinyl alcohol obtained in Example 1.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-228528 (JP, A) JP-A-63-243190 (JP, A) JP-A-7-70230 (JP, A) JP-A-60-1985 106875 (JP, A) US Patent 5,100,493 (US, A)

Claims (2)

(57) [Claims] 1. It comprises the following structural units (I) and (II), wherein the content of (I) is 0.3 to 2.
7 milligram equivalent / g and a weight average molecular weight of 3.0
A dispersant comprising a modified polyvinyl alcohol having a molecular weight of from 00 to 400,000. Embedded image (In the formula, M represents H, an alkali metal, ammonium, an alkyl ammonium, or an alkanol ammonium.) 2. The dispersant according to claim 1, wherein the dispersant is a muddy water conditioner for drilling.