JP4419463B2 - Dispersant for powder - Google Patents

Description

  The present invention relates to a dispersant in a powder slurry. More specifically, the present invention relates to a dispersing agent that disperses a high-concentration powder in a dispersion medium in a short time and has a good fluidity and a stable dispersion.

In industry, powders are used in various applications regardless of organic or inorganic. From the viewpoint of workability, the powder is often used as a dispersion. However, since the powder easily aggregates in the dispersion, there is a problem that the dispersion becomes unstable and cannot be used for a long time. .
As a method for solving such a problem, various dispersants are used in the dispersion. Examples include lignin sulfonate, formaldehyde condensate of naphthalene sulfonate, formaldehyde condensate of melamine sulfonate, aromatic sulfonic acid dispersants such as polystyrene sulfonate, polyacrylate, maleic anhydride and α- Polycarboxylic acid-based dispersants such as salts of copolymers with olefins and polyacrylic acid partial alkyl esters have been proposed.

However, opportunities for using polycarboxylic acid-based dispersants are increasing due to dispersion power and dispersion stability (see, for example, Patent Document 1).
In general, polycarboxylic acid-based dispersants have a higher molecular weight than other dispersants and may take time to act on the powder. It takes time to obtain such a dispersion (see, for example, Patent Document 2). If the dispersibility cannot be exhibited immediately after the addition, the working efficiency of adjusting the dispersion is poor. In some cases, the dispersant is excessively added, and the dispersion is separated when the dispersion force is exerted. There's a problem. In particular, the finer the particle size of the powder, the less easily the dispersibility (initial dispersibility) immediately after adjusting the dispersant.
JP 2000-185226 A (pages 1 to 6) JP 2001-019514 A (pages 1 to 4)

  An object of the present invention is to provide a dispersant that can act on various powders in a short time, can adjust a stable dispersion in a short time, and can maintain a stable dispersion for a long time.

That is, the present invention
(1) A dispersant for powder comprising the following (A) and (B), wherein the weight ratio is (A) :( B) = 1: 0.1-1;
(A) Structural unit based on polyoxyalkylene alkenyl ether represented by formula [2] (a) 35 to 65 mol%, structural unit based on maleic anhydride, maleic acid, maleate (b) 35 to 65 mol% And a polycarboxylic acid compound (B) which is a copolymer composed of 0 to 30 mol% of a structural unit (c) based on another monomer capable of copolymerization and a compound represented by the formula [1]

(In the formula, R ¹ is a hydrocarbon group having 3 to 20 carbon atoms, and M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or organic ammonium.)

(However, R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and AO is one or more oxyalkylene groups having 2 to 4 carbon atoms. R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, q represents an integer of 0 to 2, and p is an average addition mole number of oxyalkylene, and p = 1 to 150. .)

  By using the dispersant of the present invention, it is possible to disperse the powder in the dispersion medium in a short time with a low concentration of the dispersant used.

Examples of (A) polycarboxylic acid compounds used in the present invention include maleic acid-styrene sulfonate copolymers or salts thereof, maleic anhydride-olefin copolymers, hydrolysates or salts thereof, polyoxyalkylenes Monoalkyl ether (meth) acrylate- (meth) acrylic acid copolymer or salt thereof, polyoxyalkylene monoalkenyl ether-maleic acid copolymer or salt thereof, polyoxyalkylene monoalkyl monoalkenyl ether-maleic anhydride copolymer Product, its hydrolyzate or its salt.
Among these, Preferably, the structural unit (a) 35-65 mol% based on the polyoxyalkylene alkenyl ether represented by the formula [2] and the structural unit (b) 35 based on maleic anhydride, maleic acid, maleate It is a copolymer having 0 to 30 mol% of structural units (c) based on ~ 65 mol% and other monomers copolymerizable. More preferably, the structural unit (a) based on the polyoxyalkylene glycol ether represented by the formula [2] is 45 to 65 mol%, and the structural unit (b) 45 to 65 based on maleic anhydride, maleic acid, and maleate. It is a copolymer having 0 to 10 mol% of the structural unit (c) based on mol% and another copolymerizable monomer.
A constitutional unit based on another copolymerizable monomer may be added as necessary. When added, the type is selected according to various applications.

In the formula [2], R ² , R ³ and R ⁴ are a hydrogen atom or a methyl group.
q is the number of repeating methylene groups, is an integer of 0 to 2, preferably 1, more preferably q is 1, and R ² and R ⁴ are simultaneously hydrogen atoms.
In the formula [2], AO is an oxyalkylene group having 2 to 4 carbon atoms, such as an oxyethylene group, an oxypropylene group, a 2-methyloxypropylene group, a 1,2-oxybutylene group, and a 2,3-oxybutylene. The addition form may be any of a single form, a block form or a random form. An oxyethylene group and an oxypropylene group are preferred.
In the formula [2], p is the average number of moles of alkylene oxide having 2 to 4 carbon atoms, and is 1 to 150, preferably 5 to 100, more preferably 10 to 70. If the value of p exceeds 150, the resulting compound has a high viscosity, which makes it difficult to produce.
When the dispersion medium is water or a highly hydrophilic organic solvent, preferably 50 mol% or more of the oxyalkylene groups are oxyethylene groups. In the case of an organic solvent having high lipophilicity, preferably 50 mol% or more of the oxyalkylene groups are oxypropylene groups or 1,2-oxybutylene groups.

R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms. Examples of the hydrocarbon group having 1 to 22 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, Butyl, amino, isoamino, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, isotridecyl, tetradecyl, hexadecyl, octadecyl, oleyl, Examples include docosyl group, phenyl group, benzyl group, cresyl group, butylphenyl group, octylphenyl group, nonylphenyl group, and naphthyl group. Preferably it is a C1-C4 hydrocarbon group.

  In (b), examples of the maleic acid compound include maleic anhydride, maleic acid, maleate and maleate, and maleic anhydride is preferable. Examples of maleates include alkali metal salts such as lithium, sodium, and potassium, ammonium salts, and organic ammonium salts derived from organic amines. Examples of the organic amine include alkylamines such as methylamine, dimethylamine, and ethylamine, and alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, and methylethanolamine. The salt may be a mono form or a di form. As the maleate, ammonium salt, monoethanolammonium salt, diethanolammonium salt, and triethanolammonium salt are more preferable.

  Examples of the other copolymerizable monomer (c) include styrene, vinyl acetate, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, and acrylonitrile. , Methacrylonitrile, acrylamide, methacrylamide and olefins such as isobutylene, diisobutylene and vinylcyclohexane, and preferably styrene, vinyl acetate, isobutylene and diisobutylene.

(B) is a dialkylsulfosuccinic acid represented by the formula [1] or a salt thereof.
R ¹ is a hydrocarbon group having 3 to 20 carbon atoms, and examples of the hydrocarbon group having 3 to 20 carbon atoms include propyl group, isopropyl group, butyl group, isobutyl group, tertiary butyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, isotridecyl group, tetradecyl group, hexadecyl group, octadecyl group, oleyl group, docosyl group, phenyl group, benzyl group, cresyl group, butylphenyl group Octylphenyl group, nonylphenyl group, naphthyl group and the like. Preferably it is a C5-C18 hydrocarbon group.

M is a hydrogen atom, an alkali metal such as lithium, sodium or potassium, an alkaline earth metal such as calcium or magnesium, ammonium, or an organic ammonium derived from an organic amine. Examples of the organic amine include alkylamines such as methylamine, dimethylamine, and ethylamine, and alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, and methylethanolamine. The salt may be a mono form or a di form. The maleate is more preferably an ammonium salt, a monoethanolammonium salt, or a diethanolammonium salt.
R ¹ may be used alone or in combination of two or more, and R ¹ may be the same or different.

The powder to be dispersed in the present invention is not particularly limited, and organic or inorganic powder that is usually used can be used.
Examples of organic powders include phospho yellow, disazo yellow, disazo orange, naphthol red, copper phthalocyanine pigment, phosphomolybdate tungstate, tannate, katanol, tamol lake, isoindolinone erogreen, isoindolinone etho. Organic pigments such as redish, quinacridone, dioxazine violet, perinone orange, perylene vermillion, perylene scarlet, perylene red, and perylene maroon; polyamide synthetic resin, polyester synthetic resin, polyolefin synthetic resin, polycarbonate, polyvinyl chloride , Synthetic resin powders such as polymethyl methacrylate and fluororesin; aluminum stearate, zinc stearate, calcium stearate, magnesium stearate , Zinc stearate / calcium stearate composite, magnesium stearate, lead stearate, cadmium stearate, barium stearate, zinc stearate / calcium stearate composite, calcium laurate, zinc laurate, etc. . The average particle size of these organic powders varies greatly depending on the type, but is generally 100 μm or less.

  Examples of the inorganic powder include carbonates such as silicates such as kaolin, aluminum silicate, clay, talc, mica, calcium silicate, sericite, and bentonite, calcium carbonate, magnesium carbonate, barium carbonate, and basic lead carbonate. Salts, sulfates such as calcium sulfate and barium sulfate, chromates such as strontium chromate and pigment yellow, magnesium molybdate such as zinc molybdate and calcium zinc molybdate, alumina, antimony oxide, titanium oxide, cobalt oxide, tetraoxide Metal oxides such as triiron, ferric trioxide, trilead tetraoxide, lead monoxide, chromium oxide green, tungsten trioxide, yttrium oxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, iron hydroxide, metatitanium Metal hydroxides such as acids Metal carbide such as silicon carbide, tungsten carbide, boron carbide, titanium carbide, aluminum nitride, silicon nitride, boron nitride, zirconia, barium titanate, satin white, carbon black, graphite, chrome yellow, mercury sulfide, ultramarine, Paris blue Inorganic powders such as titanium yellow, chrome vermilion, lithopone, copper acetoarsenite, nickel, silver, palladium, and lead zirconate titanate. The average particle size of these inorganic powders varies greatly depending on the type, but is generally 100 μm or less, preferably 0.1 to 50 μm.

  In the present invention, the dispersion medium for dispersing the inorganic powder or the organic powder is not limited to water. For example, fuel oil such as kerosene, light oil, and kerosene; fat such as hexane, isohexane, cyclohexane, methylcyclohexane, and isooctane. Aromatic hydrocarbon oils such as benzene, toluene, xylene and cresol; alcohols such as ethanol, methanol, isopropyl alcohol, butyl alcohol and pentyl alcohol; esters such as ethyl acetate, dioctyl phthalate, soybean oil and linseed oil Oil: ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, ethylene glycol monobutyl ether, potassium Ethers such as bitol, monoglyme, diglyme, tetraglyme, methylcellosolve, butylcellosolve; diols such as butanediol, pentanediol, hexanediol; 1,1,1-trichloroethane, trichloroethylene, dichloroethylene, chlorodifluoromethane, etc. Halogenated hydrocarbon oils; ketones such as methyl isoamyl ketone, methyl isobutyl ketone, acetone, methyl ethyl ketone, and ethyl acetate; terpineol, liquid paraffin, mineral spirit, N- (2-hydroxyethyl) pyrrolidone, glycerin, and the like. Either water or a solvent other than water can be used, but water is more preferable for the effect of initial dispersion.

In the dispersant of the present invention, (A) and (B) are in a weight ratio of (A) :( B) = 1: 0.1 to 1, preferably (A) :( B) = 1: 0. 2 to 0.8. When the ratio to (A) is lower than 1: 0.1 (B), the effect of initial dispersion is poor, and when it is higher than 1: 1, the effect of initial dispersion is not improved. Usually, only the components (A) and (B) are used, but other known additives may be added as long as the effects of the present invention are not hindered. Moreover, you may mix and use it with a dispersion medium.
When using a dispersing agent, it may be used by mixing with a dispersion medium, or may be added separately.
The amount of the dispersant of the present invention used is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the inorganic powder or organic powder.
The dispersion medium is usually used in an amount of 20 to 800 parts by weight with respect to 100 parts by weight of the powder.

  Hereinafter, the present invention will be described by way of specific examples. As the dispersant, the compounds shown in Table 1 were used.

Example 1
As an inorganic powder to be dispersed in water, alumina having an average particle size of 0.5 μm was used. For Inventive Examples 1 to 6, 360 g of alumina was placed in a 1 L beaker, to which 1.8 g of dispersants A to D (0.5 parts by weight based on the powder) and 0.9 g of additives H and I were added. 140 g of water in which (0.25 parts by weight with respect to the powder) was dissolved was added, and the mixture was stirred at 120 rpm for 2 to 10 minutes using a four-blade impeller to prepare a slurry. For Comparative Examples 1 to 6, 360 g of alumina was taken in a 1 L beaker, and 140 g of water in which dispersants A to D, H and I 1.8 g (0.5 parts by weight with respect to the powder) were dissolved was added. Stir for 2-10 minutes. The dispersion state after 2 minutes and 10 minutes was evaluated according to the following criteria at each stage. The results are shown in Table 2.
A: All powders are uniformly dispersed in the dispersion medium.
○: Most of the powder is uniformly dispersed in the dispersion medium, but remains slightly at the bottom.
Δ: About half of the powder is dispersed in the dispersion medium, but aggregation is also observed.
X: The powder is not dispersed at all in the dispersion medium.

Next, the inventive examples 1 to 3 and the comparative examples 1 to 4 were measured with a dynamic viscoelasticity measuring device (Paar Physica MCR300: manufactured by Siebel Hegner, Japan) using the slurry adjusted in the above test. A corn plate (CP-25-2 (Diameter: 24.94 mm)) is attached, and at a temperature of 25 ° C., an appropriate amount of slurry immersed in the bottom of the corn plate is placed on a table, and a shear rate of 10 ^{−1 to} 100 ( The slurry viscosity was measured by changing the rotational speed to 1 / s). The result of slurry viscosity at a shear rate of 10 ^-1 (1 / s) is shown in FIG. In Comparative Example 4, the value is not shown because the slurry viscosity cannot be measured in 2 minutes of stirring.
Example 2
As an inorganic powder to be dispersed in a highly lipophilic solvent, alumina having an average particle diameter of 0.5 μm was used. For Inventive Examples 7-12, 360 g of alumina is taken in a 1 L beaker, and dispersants E-G 1.8 g (0.5 parts by weight with respect to the powder) are added thereto, and additives H and I are 0.9 g. 140 g of toluene in which (0.25 part by weight with respect to the powder) was dissolved was added, and the slurry was prepared by stirring at 120 rpm for 2 to 10 minutes using a four-blade impeller. For Comparative Examples 7 to 11, 360 g of alumina was taken in a 1 L beaker, and 140 g of toluene in which 1.8 g of dispersants E to I (0.5 parts by weight with respect to the powder) were dissolved was added thereto. The mixture was stirred for 2 to 10 minutes at 120 rpm using an impeller. The dispersion state after 2 minutes and 10 minutes was evaluated according to the following criteria at each stage. The results are shown in Table 3.
A: All powders are uniformly dispersed in the dispersion medium.
○: Most of the powder is uniformly dispersed in the dispersion medium, but remains slightly at the bottom.
Δ: About half of the powder is dispersed in the dispersion medium, but aggregation is also observed.
X: The powder is not dispersed at all in the dispersion medium.

Next, it measured on the conditions similar to Example 1 about Example 7-8 of this invention and Comparative Examples 7, 8, and 10 using the dynamic viscoelasticity measuring apparatus. The test results are shown in FIG. However, the value of Comparative Example 10 is not shown because the slurry viscosity cannot be measured in 2 minutes of stirring.
Example 3
As an inorganic powder to be dispersed in water or a highly lipophilic solvent, silicon nitride having an average particle size of 0.6 μm was used. For Invention Examples 13 to 15, 240 g of silicon nitride is placed in a 1 L beaker, and 1.2 g of dispersant (0.5 part by weight with respect to the powder) and 0.6 g of additive (0% with respect to the powder). .25 parts by weight) was dissolved in 160 g of a dispersion medium, and a slurry was prepared by stirring at 120 rpm for 2 to 10 minutes using a four-blade impeller. For Comparative Examples 12 to 15, 240 g of silicon nitride was placed in a 1 L beaker, and 1.2 g of dispersant (0.5 part by weight with respect to the powder) was added to 160 g of dispersion medium, and four blades were added. The slurry was prepared by stirring at 120 rpm for 2 to 10 minutes using an impeller. Invention Example 13 and Comparative Example 12 are water, and Examples 14 to 15 and Comparative Examples 13 to 15 are toluene. The dispersion state after 2 minutes and 10 minutes was evaluated according to the following criteria at each stage. The results are shown in Table 4.
A: All powders are uniformly dispersed in the dispersion medium.
○: Most of the powder is uniformly dispersed in the dispersion medium, but remains slightly at the bottom.
Δ: About half of the powder is dispersed in the dispersion medium, but aggregation is also observed.
X: The powder is not dispersed at all in the dispersion medium.

Next, the inventive examples 13 and 15 and the comparative examples 12, 14, and 15 were measured under the same conditions as in Example 1 using a dynamic viscoelasticity measuring apparatus. The test results are shown in FIG. However, the value of additive H is not shown because the slurry viscosity cannot be measured in 2 minutes of stirring.
Example 4
Quinacridone was used as an organic powder to be dispersed in water. For Inventive Example 16, 120 g of quinacridone was placed in a 1 L beaker, 0.6 g of dispersant A (0.5 parts by weight based on the powder), and 0.3 g of additive H (based on the powder). 360 g of water in which 0.25 parts by weight were dissolved was added, and the slurry was prepared by stirring at 120 rpm for 2 to 10 minutes using a four-blade impeller. For Comparative Examples 16 and 17, 120 g of quinacridone was placed in a 1 L beaker, and 360 g of water in which 0.6 g of dispersant (0.5 parts by weight with respect to the powder) was dissolved was added thereto, and a four-blade impeller was added. The slurry was prepared by stirring at 120 rpm for 2 to 10 minutes. The dispersion state after 2 minutes and 10 minutes was evaluated according to the following criteria at each stage. The results are shown in Table 5.
A: All powders are uniformly dispersed in the dispersion medium.
○: Most of the powder is uniformly dispersed in the dispersion medium, but remains slightly at the bottom.
Δ: About half of the powder is dispersed in the dispersion medium, but aggregation is also observed.
X: The powder is not dispersed at all in the dispersion medium.

Next, the inventive example 16 and the comparative example 16 were measured under the same conditions as in Example 1 using a viscoelastic device. The test results are shown in FIG.
As is apparent from Tables 2 to 5 and FIGS. 1 to 4, when the dispersant of the present invention was used, it was well dispersed after 2 minutes of stirring and excellent in initial dispersibility. Moreover, the thing with a low viscosity was obtained. When water was used as the dispersion medium, the slurry viscosity after 2 minutes was lower and the initial dispersibility was better.
When the dispersant of the comparative example was used, the initial dispersibility was poor and there were some which did not disperse well after 10 minutes.

Viscosity measurement results after dispersion of alumina in water Viscosity measurement results after dispersion of alumina in toluene Viscosity measurement results after dispersion of silicon nitride in water and toluene Viscosity measurement results after dispersion of quinacridone in water

Claims (1)

A dispersant for powder comprising the following (A) and (B), wherein the weight ratio is (A) :( B) = 1: 0.1-1.
(A) Structural unit based on polyoxyalkylene alkenyl ether represented by formula [2] (a) 35 to 65 mol%, structural unit based on maleic anhydride, maleic acid, maleate (b) 35 to 65 mol% And a polycarboxylic acid compound (B) which is a copolymer composed of 0 to 30 mol% of a structural unit (c) based on another monomer capable of copolymerization and a compound represented by the formula [1]

(In the formula, R ¹ is a hydrocarbon group having 3 to 20 carbon atoms, and M is a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or organic ammonium.)

(However, R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and AO is one or more oxyalkylene groups having 2 to 4 carbon atoms. ^May be block or random, R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, q represents an integer of 0 to 2, and p is an average addition mole number of an oxyalkylene group, and p = 1 to 1. 150.)

Images