JP2021075588A - Inorganic particle dispersion slurry and dispersant for inorganic particle dispersion slurry - Google Patents

Abstract

To provide an inorganic particle dispersion slurry having excellent flowability even with a pH of 1-6 and a dispersant for the slurry.SOLUTION: An inorganic particle dispersion slurry contains inorganic particles, an acid, a dispersant and water and has a pH of 1-6, the dispersant containing a polyamine compound represented by formula (1), where R1-R5 each denote at least one selected from the group consisting of a hydrogen atom, a hydrocarbon group and H-(AO)s- (AO is oxyalkylene, s is 1-80) and at least one of R1-R5 is H-(AO)s-, n is 1-6, and m is 0-2.SELECTED DRAWING: None

Description

The present invention relates to an inorganic particle-dispersed slurry and a dispersant for an inorganic particle-dispersed slurry.

"A water-soluble salt of a copolymer containing (I) (a) 40 to 60 mol% of acrylic acid and (b) 60 to 40 mol% of (maleic anhydride) maleic acid, and (II) (a) acrylic acid 80 to 80 to The copolymer (II) contains a water-soluble salt of a copolymer containing 95 mol% and (b) (maleic anhydride) 20 to 5 mol%, and the copolymer (II) is 100 parts by weight of the copolymer (I). Dispersant for coated paper, characterized by containing 30 to 300 parts by weight ", inorganic particles (heavy / light calcium carbonate, kaolin, clay, aluminum hydroxide, satin white, titanium oxide, talc or a mixture thereof) And an inorganic particle dispersion slurry composed of water is known (Patent Document 1).

Japanese Unexamined Patent Publication No. 8-188896

The above-mentioned inorganic particle-dispersed slurry has a problem that sufficient fluidity cannot be obtained when the pH (25 ° C.) is adjusted to 1 to 6. An object of the present invention is an inorganic particle-dispersed slurry having excellent fluidity even when the pH (25 ° C.) is 1 to 6 (preferably 1 to 5, more preferably 1.7 to 4.7) and this slurry. Is to provide a dispersant for.

The characteristic of the inorganic particle dispersion slurry of the present invention is that it contains inorganic particles (A), acid (B), dispersant (C) and water (D).
The pH (25 ° C) is 1-6,
The gist is that the dispersant (C) contains the polyamine compound (Y) represented by the formula (1).

R ^{1 to} R ⁵ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms and _{groups represented by H- (AO) s-} (AO is an oxyalkylene group having 2 to 3 carbon atoms, and s is an oxyalkylene group having 1 to 80 carbon atoms. It is at least one selected from the group consisting of (integer), and at least one of ^{R 1 to} R ⁵ is a group represented by _{H- (AO) s-.} n is an integer of 1 to 6, m is an integer of 0 to 2, N is a nitrogen atom, C is a carbon atom, and H is a hydrogen atom.

The inorganic particle-dispersed slurry of the present invention has excellent fluidity even when the pH (25 ° C.) is 1 to 6 (preferably 1 to 5, more preferably 1.7 to 4.7).

The dispersant of the present invention has excellent fluidity even when applied to an inorganic particle dispersion slurry having a pH (25 ° C.) of 1 to 6 (preferably 1 to 5, more preferably 1.7 to 4.7). Demonstrate.

The inorganic particles (A) are not particularly limited as long as they can be stably dispersed in water having a pH of 1 to 6, and include metal oxides and carbon.

Examples of the metal oxide include aluminum oxide, silicon oxide and titanium oxide.

Examples of carbon include graphite and carbon black.

In addition to metal oxides and carbon, the inorganic particles (A) include metal sulfates (calcium sulfate, barium sulfate, cerium sulfate, etc.) and metal silicates (aluminum silicate, potassium silicate, calcium silicate and magnesium silicate). Etc.), metals (gold, rhodium, palladium and platinum, etc.), nitrides (aluminum nitride, boron nitride, silicon nitride, etc.) and composites containing them (sepiolite, zeolite, cordierite, boehmite, imogolite, sericite, alloys, etc.) , Silicate, hydrotalite, clay, talc, mica, glass, etc.) can also be used.

The content (% by weight) of the inorganic particles (A) is preferably 1 to 80, more preferably 1 to 80, based on the weights of the inorganic particles (A), the acid (B), the dispersant (C) and the water (D). It is 10 to 70, particularly preferably 28 to 60. Within this range, the fluidity becomes even better.

The acid (B) is not particularly limited as long as the pH (25 ° C.) of the inorganic particle dispersion slurry can be adjusted to 1 to 6, and either an inorganic acid or an organic acid may be used, and these may be used alone. It may be a mixture.

Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, chromic acid, boric acid and the like.

Organic acids include carboxylic acids (acetic acid, trifluoroacetic acid, malic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, fumaric acid, tartrate acid, etc.) and sulfonic acid. Acids (methane sulfonic acid, ethane sulfonic acid, benzene sulfonic acid and p-toluene sulfonic acid) and the like can be mentioned.

Among these acids, nitric acid, boric acid and organic acids are preferable, and nitric acid and carboxylic acids are more preferable, and nitric acid and acetic acid are particularly preferable.

The content (% by weight) of the acid (B) is not limited as long as the pH (25 ° C.) of the inorganic particle dispersion slurry can be set to 1 to 6, but the inorganic particles (A), the acid (B), and the dispersant Based on the weights of (C) and water (D), 0.1 to 5 is preferable, 0.5 to 4 is more preferable, and 1.5 to 3 is particularly preferable.

The dispersant (C) contains the polyamine compound (Y) represented by the formula (1), and may be one kind or a mixture of a plurality of kinds.

Hydrocarbon groups having 1 to 10 carbon atoms include aliphatic hydrocarbon groups having 1 to 10 carbon atoms (methyl, ethyl, butyl, decyl, 2-ethylhexyl, cyclohexyl, octenyl, etc.) and aromatic groups having 6 to 10 carbon atoms. Hydrocarbon groups (phenyl, benzyl, naphthyl, etc.) and the like can be mentioned. Of these, an aliphatic hydrocarbon group having 1 to 10 carbon atoms is preferable, and methyl, ethyl, butyl, decyl, and 2-ethylhexyl are more preferable.

Among the groups represented by H- (AO) _s- , the AO is an oxyethylene group and an oxypropylene group, which may contain one type or two types, but it is preferably composed of any one type.

When (AO) _s contains two kinds of AO, it may be random, block, or a mixture thereof.

s is an integer of 1 to 80, preferably an integer of 1 to 60, and more preferably an integer of 1 to 40.

The polyamine compound (Y) is a known method (for example, an alkylene oxide addition reaction between polyamine and ethylene oxide and / or propylene oxide, an alkylene oxide addition reaction and a hydrolysis reaction between a ketiminated product of polyamine and ethylene oxide and / or propylene oxide). ) To be easily obtained. In the method using a ketiminated product of polyamine, the primary amino group is protected with a ketone (ketimization, that is, iminization), the secondary amino group is selectively subjected to an alkylene oxide addition reaction, and then a hydrolysis reaction is carried out. This is a method of removing a protecting group (imino group) to restore a primary amino group (Japanese Patent Laid-Open No. 1-249748, etc.).

Examples of polyamines include diamine {alkylenediamine (methylenediamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, etc.) and N-substituted diamines (N-methyl-ethylenediamine, N-ethyl-ethylenediamine, N). -Decilethylenediamine, N, N'-dimethylethylenediamine, N- (2-hydroxyethyl) ethylenediamine and N-ethyl-1,3-propylenediamine, etc.)}; Triamine {dialkylenetriamine (diethylenetriamine, bis (hexamethylene)) Triamine and 3,3'-diamino-dipropylamine, etc.) and N-substituted triamine (N, N-bis (3-aminopropyl) methylamine, N, N', N "-trimethyldiethylenetriamine, N, N, N'', N''-tetraisopropyldiethylenetriamine and N, N, N'', N''-tetrabutyldiethylenetriamine, etc.}; and tetramine {trialkylenetetramine (triethylenetetramine, N, N'-bis (triethylenetetramine, N, N'-bis) 3-Aminopropyl) ethylenediamine and N, N'-bis (3-aminopropyl) -1,3-propanediamine, etc.) and N-substituted tetramine (N, N'''-diisopropyltriethylenetetramine, etc.)} included. Of these, from the viewpoint of fluidity, alkylenediamine, N-substituted diamine, dialkylenetriamine and trialkylenetetramine are preferable, and ethylenediamine, hexamethylenediamine, N-decyl-ethylenediamine, diethylenetriamine and triethylenetetramine are more preferable. ..

A ketiminated product of a polyamine is an imine that is more easily obtained in the reaction of a polyamine with a ketone.

Ketones include ketones having 3 to 9 carbon atoms, such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl pentyl ketone, methyl hexyl ketone, diethyl ketone, ethyl propyl ketone, ethyl butyl ketone, ethyl pentyl ketone, ethyl hexyl ketone, and di. Examples thereof include propyl ketone, propyl butyl ketone, propyl pentyl ketone and propyl hexyl ketone. Of these, acetone, methyl ethyl ketone and methyl butyl ketone are preferable from the viewpoint of ease of removing the ketone after hydrolysis.

The dispersant (C) may contain an aqueous solvent. Examples of the aqueous solvent include water, alcohols having 1 to 6 carbon atoms (ethyl alcohol, methyl alcohol, ethylene glycol, diethylene glycol, etc.), ketones having 1 to 6 carbon atoms (methylisobutylketone, acetone, etc.), and the like. It may be used alone or in combination.

The dispersant (C) preferably does not contain an aqueous solvent, but when the dispersant (C) contains an aqueous solvent, the content (% by weight) of the aqueous solvent is based on the weight of the polyoxyalkylene compound (Y) and the aqueous solvent. , 1 to 90 is preferable. In this case, the content (% by weight) of the polyamine compound (Y) is preferably about 10 to 99 based on the weight of the polyamine compound (Y) and the aqueous solvent.

The content (% by weight) of the dispersant (C) is preferably 0.05 to 30 based on the weights of the inorganic particles (A), the acid (B), the dispersant (C) and the water (D). It is preferably 0.1 to 10, particularly preferably 0.5 to 5. Within this range, the fluidity becomes even better.

The water (D) is not particularly limited, but ion-exchanged water, ultrapure water and the like are preferable.

The content (% by weight) of water (D) is preferably 1 to 90, more preferably 20 based on the weights of the inorganic particles (A), acid (B), dispersant (C) and water (D). -80, particularly preferably 38-65. Within this range, the fluidity becomes even better.

In addition to the inorganic particles (A), acid (B), dispersant (C) and water (D), the inorganic particle dispersion slurry of the present invention contains other constituents (water-soluble organic compounds, water-soluble metal compounds, etc.). And other additives (thickeners, rust inhibitors, defoamers, etc.) may be contained.

Examples of the water-soluble organic compound include an organic compound that is easily dissolved in water (0 to 100 ° C., preferably 5 to 60 ° C.), and examples thereof include alcohols having 1 to 4 carbon atoms and ketones having 3 to 6 carbon atoms. Be done.

The water-soluble metal compound includes a metal compound that is easily dissolved in water (0 to 100 ° C, preferably 5 to 60 ° C), and includes an organic acid metal salt, a metal nitrate, a metal oxynitrite, a metal hydroxide and a metal. Examples include nitrite.

When containing other constituents, the content (% by weight) of the other constituents is 0 based on the weight of the inorganic particles (A), acid (B), dispersant (C) and water (D). .1 to 70 is preferable, more preferably 0.3 to 60, and particularly preferably 7 to 54.

Thickeners include known natural or synthetic thickeners (inorganic compounds, cellulose compounds, proteins, acrylic polymers, vinyl polymers, etc.).

The rust preventive includes at least one selected from the group consisting of nitrogen-containing organic rust preventives, polyhydric alcohol partial ester rust preventives, and the like.

Examples of the defoaming agent include known water-based defoaming agents (silicone-based defoaming agents, mineral oil-based defoaming agents, polyether-based defoaming agents, wax-based defoaming agents, and the like).

When other additives are contained, the content (% by weight) of the other additives is preferably based on the weight of the inorganic particles (A), acid (B), dispersant (C) and water (D). Is 0.1 to 5, more preferably 0.5 to 3, and particularly preferably 0.5 to 1.

The inorganic particle dispersion slurry of the present invention is a uniform mixture of inorganic particles (A), acid (B), dispersant (C) and water (D), and if necessary, other constituents and / or other additives. If it can be dispersed, there is no limitation on the production method, and it can be obtained by using a known mixing and dispersing machine. It is preferable to uniformly mix the components other than the inorganic particles (A) and then disperse the inorganic particles (A). Inorganic particles may be crushed or crushed during uniform mixing and dispersion.

The number average particle diameter (μm) of the inorganic particles (A) in the inorganic particle dispersion slurry of the present invention is preferably 0.01 to 100, more preferably 0.02 to 50, and particularly preferably 0.08 to 40. is there.

The number average particle size is determined using a laser diffraction analysis type particle size distribution meter (for example, LA-950V2, HORIBA, Ltd.) based on JIS X 8825: 2013 (particle size analysis-laser diffraction / scattering method).

The inorganic particle-dispersed slurry of the present invention may be applied to various base materials (plastic, wood, leather, metal, ceramics, etc.) or may be dry-molded. Further, it may be mixed with a binder or the like and applied to various substrates, or may be dried and molded. Further, it may be sintered after being coated or molded.

Hereinafter, unless otherwise specified, parts mean parts by weight and% means% by weight.
The following polyamine compounds (Y1) to (Y8) {<> are values corresponding to the formula (1)} were synthesized by a known method, and the dispersants (c1) to (c8) of the present invention were synthesized in this order. And said. Further, according to Production Example 1 of Patent Document 1, a dispersant for comparison (c9; sodium acrylate-sodium maleate copolymer <sodium acrylate: sodium maleate = 50:50 (mol%). ), Mn = 5000> 35% aqueous solution) was prepared.

(Y1) Ethylenediamine / ethylene oxide 4 mol / propylene oxide 4 mol block adduct <n = 2, m = 0, s = 2>
(Y2) Ethylenediamine / ethylene oxide 4 mol adduct <n = 2, m = 0, s = 1>
(Y3) Ethylenediamine / Propylene Oxide 4 Mol Addition <n = 2, m = 0, s = 1>
(Y4) Ethylenediamine / ethylene oxide 3 mol adduct <n = 2, m = 0, s = 1> (R ¹ is a hydrogen atom, and R ² , R ⁴ and R ⁵ contain ethylene oxide).
(Y5) Hexamethylenediamine / ethylene oxide 8 mol adduct <n = 6, m = 0, s = 2>
(Y6) diethylenetriamine-propylene oxide 10-mol adduct <n = 2, m = 1 , s = 10> example using the ketimine of a polyamine ^{(R 1, R 2, R} 4 and ^{R 5} is a hydrogen atom, R ³ contains a polyoxypropylene chain.)
(Y7) Triethylenetetramine, ethylene oxide 60 mol, propylene oxide 20 mol Random adduct <n = 2, m = 2, s = 40> Examples using polyamine ketiminated products (R ¹ , R ² , R ⁴ and R) ⁵ is a hydrogen atom, and R ³ contains a polyoxyethylene / polyoxypropylene chain.)
(Y8) N-decyl-ethylenediamine / ethylene oxide 30 mol adduct <n = 2, m = 0, s = 10> (R ¹ is a decyl group, and R ² , R ⁴ and R ⁵ are polyoxyethylene chains. including.)

<Example 1>
2 parts of dispersant (c1), 55 parts of water (d1; ion-exchanged water) and 3 parts of acid (b1; acetic acid, EP standard, Nacalai Tesque Co., Ltd.) are uniformly mixed, and a homomixer (HIGH-FLEX DISPERSER, Co., Ltd.) While stirring at 1,000 rpm using SMT), 40 parts of inorganic particles (alumina, A-11, Sumitomo Chemical Co., Ltd.) were gradually added, and after the addition was completed, stirring was performed at 1,500 rpm for 5 minutes. The inorganic particle dispersion slurry (1) of the present invention was obtained. The number average particle diameter of the inorganic particles (a11) in the inorganic particle dispersion slurry (1) was 33 μm.

The number average particle size is measured using a laser diffraction type particle size analyzer (LA-950V2, HORIBA, Ltd.) in water with an electrical conductivity of 0.1 mS / m or less so that the measurement sample concentration is 0.1%. A sample was added and the measurement was performed at a measurement temperature of 25 ± 10 ° C. The refractive index of the circulating fluid (water) is 1.33, the refractive index of alumina is 1.66, the refractive index of carbon black is 1.92, the refractive index of titanium oxide is 2.50, and the refractive index of hydrophilic silica is 1.45. Using. The same applies hereinafter.

<Examples 2 to 8>
The inorganic particle dispersion slurry (2-8) of the present invention was obtained in the same manner as in Example 1 except that the dispersant (c1) was changed to any of the dispersants (c2 to c8). The number average particle diameter of the inorganic particles (a12) in the inorganic particle dispersion slurry (2) was 32 μm. The number average particle diameter of the inorganic particles (a13) in the inorganic particle dispersion slurry (3) was 32 μm. The number average particle diameter of the inorganic particles (a14) in the inorganic particle dispersion slurry (4) was 33 μm. The number average particle diameter of the inorganic particles (a15) in the inorganic particle dispersion slurry (5) was 36 μm. The number average particle diameter of the inorganic particles (a16) in the inorganic particle dispersion slurry (6) was 33 μm. The number average particle diameter of the inorganic particles (a17) in the inorganic particle dispersion slurry (7) was 36 μm. The number average particle diameter of the inorganic particles (a18) in the inorganic particle dispersion slurry (8) was 36 μm.

<Example 9>
5 parts of dispersant (c1), 65 parts of water (d1; ion-exchanged water), 2 parts of acid (b2; nitric acid, JIS reagent special grade, Nacalai Tesque Co., Ltd.) and inorganic particles (carbon black, MA100, Mitsubishi Chemical Co., Ltd.) 28 parts are uniformly mixed, stirred using a stirring / defoaming device (Mazelstar KK-VT300, Kurashiki Spinning Co., Ltd.), and dispersed at an output of 240 W for 30 seconds with an ultrasonic disperser (UP400S, Heelsher Co., Ltd.). Inorganic particle dispersion slurry (9) was obtained. The number average particle diameter of the inorganic particles (a21) in the inorganic particle dispersion slurry (9) was 0.08 μm.

<Example 10>
The inorganic particle dispersion slurry (10) of the present invention was obtained in the same manner as in Example 9 except that the dispersant (c1) was changed to the dispersant (c2). The number average particle diameter of the inorganic particles (a22) in the inorganic particle dispersion slurry (10) was 0.08 μm.

<Example 11>
After uniformly mixing 60 parts of inorganic particles (titanium oxide, R-820, Ishihara Sangyo Co., Ltd.), 1.5 parts of acid (b1), 0.5 part of dispersant (c1) and 38 parts of water (d1), homo The inorganic particle dispersion slurry (11) of the present invention was obtained by stirring at 1,500 rpm for 5 minutes using a mixer (HIGH-FLEX DISPERSER, SMT Co., Ltd.). The number average particle diameter of the inorganic particles (a31) in the inorganic particle dispersion slurry (11) was 0.49 μm.

<Example 12>
After uniformly mixing 35 parts of inorganic particles (hydrophilic silica, nip seal NA, Toso Silica Co., Ltd.), 2 parts of acid (b1), 3 parts of dispersant (c1) and 60 parts of water (d1), a homomixer (HIGH) The inorganic particle-dispersed slurry (12) of the present invention was obtained by stirring at 1,500 rpm for 5 minutes using −FLEX DISPERSER, SMT Co., Ltd.). The number average particle diameter of the inorganic particles (a41) in the inorganic particle dispersion slurry (12) was 10 μm.

<Example 13>
The inorganic particle-dispersed slurry (13) of the present invention was obtained in the same manner as in Example 12 except that the acid (b1) was changed to the acid (b2). The number average particle diameter of the inorganic particles (a42) in the inorganic particle dispersion slurry (13) was 10 μm.

<Comparative example 1>
An attempt was made to prepare a comparative inorganic particle dispersion slurry (14) in the same manner as in Example 1 except that the dispersant (c1) was changed to water (d1), but the inorganic particles settled and the inorganic particles A dispersed slurry could not be obtained.

<Comparative example 2>
An inorganic particle-dispersed slurry (15) for comparison was obtained in the same manner as in Example 1 except that the dispersant (c1) was not used. The number average particle diameter of the inorganic particles (a19) in the inorganic particle dispersion slurry (15) was 37 μm.

<Comparative example 3>
An inorganic particle dispersion slurry (16) for comparison was obtained in the same manner as in Example 1 except that the dispersant (c1) was changed to the dispersant (c9) for comparison. The number average particle diameter of the inorganic particles (a20) in the inorganic particle dispersion slurry (16) was 36 μm.

<Comparative example 4>
An attempt was made to prepare a comparative inorganic particle dispersion slurry (17) in the same manner as in Example 9 except that the dispersant (c1) was changed to water (d1), but the inorganic particles aggregated and solidified as a whole. Inorganic particle dispersion slurry could not be obtained.

<Comparative example 5>
An inorganic particle-dispersed slurry (18) for comparison was obtained in the same manner as in Example 9 except that the dispersant (c1) was changed to the dispersant (c9). The number average particle diameter of the inorganic particles (a23) in the inorganic particle dispersion slurry (18) was 0.18 μm.

<Comparative Example 6>
An inorganic particle-dispersed slurry (19) for comparison was obtained in the same manner as in Example 11 except that the dispersant (c1) was changed to water (d1). The number average particle diameter of the inorganic particles (a32) in the inorganic particle dispersion slurry (19) was 1.1 μm.

<Comparative Example 7>
An inorganic particle dispersion slurry (20) for comparison was obtained in the same manner as in Example 11 except that the dispersant (c1) was changed to the dispersant (c9). The number average particle diameter of the inorganic particles (a33) in the inorganic particle dispersion slurry (20) was 0.72 μm.

<Comparative Example 8>
An inorganic particle-dispersed slurry (21) for comparison was obtained in the same manner as in Example 12 except that the dispersant (c1) was changed to water (d1). The number average particle diameter of the inorganic particles (a43) in the inorganic particle dispersion slurry (21) was 12 μm.

<Comparative Example 9>
An inorganic particle-dispersed slurry (22) for comparison was obtained in the same manner as in Example 12 except that the dispersant (c1) was changed to the dispersant (c9). The number average particle diameter of the inorganic particles (a44) in the inorganic particle dispersion slurry (22) was 11 μm.

<Comparative Example 10>
An inorganic particle-dispersed slurry (23) for comparison was obtained in the same manner as in Example 13 except that the dispersant (c1) was changed to water (d1). The number average particle diameter of the inorganic particles (a45) in the inorganic particle dispersion slurry (23) was 12 μm.

<Comparative Example 11>
An inorganic particle-dispersed slurry (24) for comparison was obtained in the same manner as in Example 13 except that the dispersant (c1) was changed to the dispersant (c9). The number average particle diameter of the inorganic particles (a46) in the inorganic particle dispersion slurry (24) was 11 μm.

<Liquidity evaluation 1>
Inorganic particle dispersion slurries prepared in Examples 1 to 8 and 11 to 13 (1) to (8), (11) to (13), and inorganic particle slurries prepared in Comparative Examples 2, 3 and 6 to 11 (15). ), (16) and (19) to (24), the viscosities (mPa · s) were measured using a BM type viscometer (VISCOMETER TV-20, Toki Sangyo Co., Ltd., 25 ° C., 60 rpm). Further, the pH of the slurry was measured using a multi-water quality meter (MM-43M, DKK-TOA CORPORATION, 25 ° C.). These results are shown in the table below.

「−」は無機粒子分散スラリーが得られなかったことを意味し、「∞」は測定範囲（ｍＰａ・ｓ）を越えたことを意味する。

"-" Means that the inorganic particle dispersion slurry was not obtained, and "∞" means that the measurement range (mPa · s) was exceeded.

「−」は無機粒子分散スラリーが得られなかったことを意味する。 <Liquidity evaluation 2>
For the inorganic particle-dispersed slurries (9) and (10) prepared in Examples 9 and 10, and the inorganic particle-dispersed slurry (18) prepared in Comparative Example 5, an E-type viscometer (RE80 type, Toki Sangyo Co., Ltd.) The viscosity (mPa · s) was measured using (25 ° C., 10 rpm). Further, the pH of the slurry was measured using a multi-water quality meter (MM-43M, DKK-TOA CORPORATION, 25 ° C.). These results are shown in the table below.

"-" Means that the inorganic particle dispersion slurry was not obtained.

The inorganic particle-dispersed slurry prepared in the examples had excellent fluidity even at a pH (25 ° C.) of 1 to 6 as compared with the inorganic particle-dispersed slurry prepared in the comparative example. The dispersant of the present invention exhibited excellent fluidity even when applied to an inorganic particle dispersion slurry having a pH (25 ° C.) of 1 to 6.

Claims (3)

It contains inorganic particles (A), acid (B), dispersant (C) and water (D).
The pH (25 ° C) is 1-6,
An inorganic particle dispersion slurry, wherein the dispersant (C) contains a polyamine compound (Y) represented by the formula (1).

R ^{1 to} R ⁵ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms and _{groups represented by H- (AO) s-} (AO is an oxyalkylene group having 2 to 3 carbon atoms, and s is an oxyalkylene group having 1 to 80 carbon atoms. It is at least one selected from the group consisting of (integer), and at least one of ^{R 1 to} R ⁵ is a group represented by _{H- (AO) s-.} n is an integer of 1 to 6, m is an integer of 0 to 2, N is a nitrogen atom, C is a carbon atom, and H is a hydrogen atom. The inorganic particle dispersion slurry according to claim 1, wherein the inorganic particles (A) are metal oxides and / or carbon. A dispersant for an inorganic particle dispersion slurry containing inorganic particles (A), acid (B), dispersant (C) and water (D) and having a pH (25 ° C.) of 1 to 6.
A dispersant containing the polyamine compound (Y) represented by the formula (1).

R ^{1 to} R ⁵ are hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms and _{groups represented by H- (AO) s-} (AO is an oxyalkylene group having 2 to 3 carbon atoms, and s is an oxyalkylene group having 1 to 80 carbon atoms. It is at least one selected from the group consisting of (integer), and at least one of ^{R 1 to} R ⁵ is a group represented by _{H- (AO) s-.} n is an integer of 1 to 6, m is an integer of 0 to 2, N is a nitrogen atom, C is a carbon atom, and H is a hydrogen atom.