Inorganic particle dispersion slurry and dispersant for inorganic particle dispersion slurry

Abstract

To provide an inorganic particle dispersion slurry having excellent flowability even with a pH (25°C) of 1-6, and a dispersant for the slurry.SOLUTION: An inorganic particle dispersion slurry contains an inorganic particle (A), an acid (B), a dispersant (C) and water (D), and has a pH (25°C) of 1-6, with the dispersant (C) containing a polyoxyalkylene compound (Y) represented by formula (1): HO-(EO) p / (PO) q-H (1), where EO is an oxyethylene group, PO is an oxypropylene group, p is an integer of 0-226, q is an integer of 0-172, and the sum of p and q, (p+q), is at least 2.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an inorganic particle dispersion slurry and a dispersant for the inorganic particle dispersion slurry. [Background technology]

[0002] Patent Document 1 discloses an inorganic particle dispersion slurry comprising inorganic particles (heavy or light calcium carbonate, kaolin, clay, aluminum hydroxide, satin white, titanium oxide, talc, or a mixture thereof) and water, which dispersion agent for coated paper comprises (I) a water-soluble salt of a copolymer comprising (a) 40 to 60 mol % of acrylic acid and (b) 60 to 40 mol % of maleic anhydride, and (II) a water-soluble salt of a copolymer comprising (a) 80 to 95 mol % of acrylic acid and (b) 20 to 5 mol % of maleic anhydride, and is characterized in that it contains 30 to 300 parts by weight of copolymer (II) per 100 parts by weight of copolymer (I). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-188986 Summary of the Invention [Problem to be solved by the invention]

[0004] The above inorganic particle-dispersed slurry has a problem in that it does not have sufficient fluidity when the pH (25°C) is adjusted to 1 to 6. An object of the present invention is to provide an inorganic particle-dispersed slurry that has excellent fluidity even when the pH (25°C) is 1 to 6 (preferably 1 to 5, more preferably 1.6 to 4.5), and a dispersant for this slurry. [Means for solving the problem]

[0005] The inorganic particle dispersion slurry of the present invention is characterized in that it contains inorganic particles (A), an acid (B), a dispersant (C), and water (D), pH (25°C) is 1 to 4.5, The dispersant (C) contains a polyoxyalkylene compound (Y) represented by formula (1). become The gist of this is that the polymeric material is made of at least one water-dissipating polymer having a carbonyloxy bonding group in its linear molecular structure, and the polymeric material does not contain water-soluble nylon.

[0006] HO-(EO)p / (PO)qH (1)

[0007] EO is an oxyethylene group, PO is an oxypropylene group, p is an integer of 0 to 226, q is an integer of 0 to 172, and the sum of p and q (p+q) is An integer between 30 and 250 Represents.

[0008] The dispersant of the present invention is characterized in that it is a dispersant for an inorganic particle dispersion slurry (excluding those containing a polymeric material of at least one water-dispersible polymer having a carbonyloxy-bonding group in a linear molecular structure or a water-soluble nylon) containing inorganic particles (A), an acid (B), a dispersant (C), and water (D) and having a pH (25°C) of 1 to 4.5, A polyoxyalkylene compound represented by formula (1) {HO-〔(CH 2 CH 2 O) x -(CH(CH 3 )CH 2 O) y 〕 n -H (wherein x is 1 to 50, y is 1 to 50, and n is 2 to 25); and polyoxyethylene-polyoxypropylene condensates HO(C 2 H 4 O) a -(C 3 H 6 O) b -(C 2 H 4 O) c Excluding H.} Contains become The main points are as follows.

[0009] HO-(EO)p / (PO)qH (1)

[0010] EO is an oxyethylene group, PO is an oxypropylene group, p is an integer of 0 to 226, q is an integer of 1 to 172, and the sum of p and q (p+q) is An integer between 30 and 250 Represents. [Effects of the Invention]

[0011] 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, and more preferably 1.6 to 4.5).

[0012] The dispersant of the present invention exhibits 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 1.6 to 4.5). DETAILED DESCRIPTION OF THE INVENTION

[0013] The inorganic particles (A) are not particularly limited as long as they can be stably dispersed in water of pH 1 to 6, and include metal oxides and carbon.

[0014] Examples of metal oxides include aluminum oxide, silicon oxide, and titanium oxide.

[0015] Examples of carbon include graphite and carbon black.

[0016] In addition to metal oxides and carbon, the inorganic particles (A) may also include metal sulfates (calcium sulfate, barium sulfate, cerium sulfate, etc.), metal silicates (aluminum silicate, potassium silicate, calcium silicate, magnesium silicate, etc.), metals (gold, rhodium, palladium, platinum, etc.), nitrides (aluminum nitride, boron nitride, silicon nitride, etc.), and composites containing these (sepiolite, zeolite, cordierite, boehmite, imogolite, sericite, alloys, diatomaceous earth, hydrotalcite, clay, talc, mica, glass, etc.).

[0017] The content (wt %) of the inorganic particles (A) based on the weight of the inorganic particles (A), acid (B), dispersant (C) and water (D) is preferably 1 to 80, more preferably 10 to 70, and particularly preferably 28 to 60. Within this range, the fluidity becomes even better.

[0018] The acid (B) is not particularly limited as long as it can adjust the pH (25°C) of the inorganic particle dispersion slurry to 1 to 6, and may be either an inorganic acid or an organic acid, which may be used alone or in the form of a mixture.

[0019] Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, chromic acid, and boric acid.

[0020] Examples of 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, and tartaric acid) and sulfonic acids (methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfone).

[0021] Of these acids, nitric acid, boric acid and organic acids are preferred, nitric acid and carboxylic acids are more preferred, and nitric acid and acetic acid are particularly preferred.

[0022] The content (wt %) of the acid (B) is not limited as long as it can adjust the pH (25°C) of the inorganic particle dispersion slurry to 1 to 6, but is preferably 0.1 to 5, more preferably 0.5 to 4, and particularly preferably 1.5 to 3, based on the weight of the inorganic particles (A), acid (B), dispersant (C), and water (D).

[0023] The dispersant (C) contains a polyoxyalkylene compound (Y) represented by formula (1), and may be one type or a mixture of multiple types.

[0024] The "(EO)p / (PO)q" may be in a random or block form, or a mixture of these, but preferably has at least a block form.

[0025] The polyoxyalkylene compound (Y) is preferably a Pluronic block polymer, a reverse Pluronic block polymer, polyethylene oxide, or polypropylene oxide, and more preferably a reverse Pluronic block polymer.

[0026] The method for producing the polyoxyalkylene compound (Y) is not particularly limited, and it can be obtained by a known alkylene oxide addition reaction.

[0027] The dispersant (C) may contain an aqueous solvent, such as water, alcohols having 1 to 6 carbon atoms (e.g., ethyl alcohol, methyl alcohol, ethylene glycol, and diethylene glycol), and ketones having 1 to 6 carbon atoms (e.g., methyl isobutyl ketone and acetone), which may be used alone or in combination.

[0028] It is preferable that the dispersant (C) does not contain an aqueous solvent, but when it contains an aqueous solvent, the content (wt%) of the aqueous solvent is preferably about 1 to 90 based on the weight of the polyoxyalkylene compound (Y) and the aqueous solvent. In this case, the content (wt%) of the polyoxyalkylene compound (Y) is preferably about 10 to 99 based on the weight of the polyoxyalkylene compound (Y) and the aqueous solvent.

[0029] The content (wt %) of the dispersant (C) based on the weight of the inorganic particles (A), the acid (B), the dispersant (C) and the water (D) is preferably 0.05 to 30, more preferably 0.1 to 10, and particularly preferably 0.5 to 5. Within this range, the fluidity becomes even better.

[0030] The water (D) is not particularly limited, but ion-exchanged water, ultrapure water, and the like are preferred.

[0031] The content (wt %) of water (D) based on the weight of the inorganic particles (A), acid (B), dispersant (C) and water (D) is preferably 1 to 90, more preferably 20 to 80, and particularly preferably 38 to 65. Within this range, the fluidity becomes even better.

[0032] The inorganic particle dispersion slurry of the present invention may contain, in addition to the inorganic particles (A), the acid (B), the dispersant (C), and the water (D), other constituent components (such as a water-soluble organic compound and a water-soluble metal compound) and other additives (such as a thickener, a rust inhibitor, and an antifoaming agent).

[0033] The water-soluble organic compounds include organic compounds that are easily soluble in water (0 to 100°C, preferably 5 to 60°C), such as alcohols having 1 to 4 carbon atoms and ketones having 3 to 6 carbon atoms.

[0034] Water-soluble metal compounds include metal compounds that are easily soluble in water (0 to 100°C, preferably 5 to 60°C), such as organic acid metal salts, metal nitrates, metal oxynitrates, metal hydroxides, and metal nitrites.

[0035] When other components are contained, the content (wt %) of the other components is preferably 0.1 to 70, more preferably 0.3 to 60, and particularly preferably 7 to 54, based on the weight of the inorganic particles (A), acid (B), dispersant (C), and water (D).

[0036] The thickeners include known natural or synthetic thickeners (inorganic compounds, cellulose compounds, proteins, acrylic polymers, vinyl polymers, etc.).

[0037] The rust inhibitor includes at least one selected from the group consisting of nitrogen-containing organic rust inhibitors and polyhydric alcohol partial ester rust inhibitors.

[0038] The defoaming agent includes known defoaming agents for aqueous systems (such as silicone-based defoaming agents, mineral oil-based defoaming agents, polyether-based defoaming agents, and wax-based defoaming agents).

[0039] When other additives are contained, the content (wt %) of the other additives is preferably 0.1 to 5, more preferably 0.5 to 3, and particularly preferably 0.5 to 1, based on the weight of the inorganic particles (A), acid (B), dispersant (C), and water (D).

[0040] The inorganic particle dispersion slurry of the present invention can be produced by any known mixer / disperser as long as it can uniformly mix and disperse the inorganic particles (A), acid (B), dispersant (C), and water (D), as well as other components and / or other additives as necessary. It is preferable to uniformly mix the components other than the inorganic particles (A) before dispersing the inorganic particles (A). During the uniform mixing and dispersion, the inorganic particles may be pulverized or crushed.

[0041] The number average particle size (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 36.

[0042] The number average particle size can be determined using a laser diffraction analysis particle size distribution analyzer (for example, LA-950V2, Horiba, Ltd.) in accordance with JIS X8825:2013 (particle size analysis - laser diffraction and scattering method).

[0043] The inorganic particle dispersion slurry of the present invention may be applied to various substrates (plastics, wood, leather, metals, ceramics, etc.) or may be dried and molded. Alternatively, it may be mixed with a binder or the like and then applied to various substrates or may be dried and molded. Furthermore, it may be sintered after application or molding. [Example]

[0044] Unless otherwise specified, "parts" below means "parts by weight" and "%" means "% by weight." The following polyoxyalkylene compounds (Y1) to (Y7) {values ​​in < > correspond to those in formula (1)} were synthesized by known methods and designated dispersants (c1) to (c7) of the present invention, respectively. Furthermore, a comparative dispersant (c8; a 35% aqueous solution of sodium acrylate-sodium maleate copolymer (sodium acrylate:sodium maleate = 50:50 (mol %), Mn = 5000) was prepared in accordance with Production Example 1 of Patent Document 1.

[0045] (Y1) Ethylene oxide-propylene oxide block copolymer<p=20、q=10> ;Reverse Pluronic block polymer (Y2) Ethylene oxide-propylene oxide block copolymer<p=5、q=31> Pluronic block polymer (Y3) Ethylene oxide-propylene oxide block copolymer<p=9、q=28> ;Reverse Pluronic block polymer (Y4) Polyethylene oxide<p=144、q=0> (Y5) Polypropylene oxide<p=0、q=72> (Y6) Polyethylene oxide<p=200、q=0> (Y7) Ethylene oxide-propylene oxide block copolymer<p=100、q=150> Pluronic block polymer

[0046] Example 1 Two parts of dispersant (c1), 55 parts of water (d1; ion-exchanged water), and 3 parts of acid (b1; acetic acid, EP standard, Nacalai Tesque, Inc.) were mixed uniformly, and while stirring at 1,000 rpm using a homomixer (HIGH-FLEX DISPERSER, SMT Co., Ltd.), 40 parts of inorganic particles (alumina, A-11, Sumitomo Chemical Co., Ltd.) were gradually added. After the addition was completed, stirring was continued at 1,500 rpm for 5 minutes to obtain inorganic particle dispersion slurry (1) of the present invention. The number average particle diameter of the inorganic particles (a11) in inorganic particle dispersion slurry (1) was 33 μm.

[0047] The number-average particle size was measured using a laser diffraction particle size analyzer (LA-950V2, Horiba, Ltd.) by adding a measurement sample to water with an electrical conductivity of 0.1 mS / m or less to give a measurement sample concentration of 0.1%, at a measurement temperature of 25±10°C. The refractive indexes used were 1.33 for the circulating fluid (water), 1.66 for alumina, 1.92 for carbon black, 2.50 for titanium oxide, and 1.45 for hydrophilic silica. The same applies below.

[0048] <Examples 2 to 7> Inorganic particle dispersion slurries (2 to 7) of the present invention were obtained in the same manner as in Example 1, except that the dispersant (c1) was changed to one of the dispersants (c2 to c7). The number average particle diameter of inorganic particles (a12) in inorganic particle dispersion slurry (2) was 34 μm. The number average particle diameter of inorganic particles (a13) in inorganic particle dispersion slurry (3) was 33 μm. The number average particle diameter of inorganic particles (a14) in inorganic particle dispersion slurry (4) was 35 μm. The number average particle diameter of inorganic particles (a15) in inorganic particle dispersion slurry (5) was 36 μm. The number average particle diameter of inorganic particles (a16) in inorganic particle dispersion slurry (6) was 36 μm. The number average particle diameter of inorganic particles (a17) in inorganic particle dispersion slurry (7) was 36 μm.

[0049] Example 8 Five parts of dispersant (c1), 65 parts of water (d1; ion-exchanged water), 2 parts of acid (b2; nitric acid, JIS special grade reagent, Nacalai Tesque, Inc.), and 28 parts of inorganic particles (carbon black, MA100, Mitsubishi Chemical Corporation) were uniformly mixed, stirred using a mixer / defoamer (Mazerustar KK-VT300, Kurabo Industries, Ltd.), and dispersed for 30 seconds at 240 W using an ultrasonic disperser (UP400S, Hielscher) to obtain inorganic particle dispersion slurry (8) of the present invention. The number average particle diameter of inorganic particles (a21) in inorganic particle dispersion slurry (8) was 0.08 μm.

[0050] Example 9 Except for changing the dispersant (c1) to the dispersant (c2), an inorganic particle dispersion slurry (9) of the present invention was obtained in the same manner as in Example 8. The number average particle diameter of the inorganic particles (a22) in the inorganic particle dispersion slurry (9) was 0.08 μm.

[0051] Example 10 60 parts of inorganic particles (titanium oxide, R-820, Ishihara Sangyo Kaisha), 1.5 parts of acid (b1), 0.5 parts of dispersant (c1), and 38 parts of water (d1) were uniformly mixed and then stirred at 1,500 rpm for 5 minutes using a homomixer (HIGH-FLEX DISPERSER, SMT Corporation) to obtain inorganic particle dispersion slurry (10) of the present invention. The number average particle diameter of inorganic particles (a31) in inorganic particle dispersion slurry (10) was 0.51 μm.

[0052] Example 11 40 parts of inorganic particles (hydrophilic silica, Nipsil NA, Tosoh Silica Corporation), 2 parts of acid (b1), 2 parts of dispersant (c1), and 56 parts of water (d1) were uniformly mixed and then stirred at 1,500 rpm for 5 minutes using a homomixer (HIGH-FLEX DISPERSER, SMT Corporation) to obtain inorganic particle dispersion slurry (11) of the present invention. The number average particle diameter of inorganic particles (a41) in inorganic particle dispersion slurry (11) was 20 μm.

[0053] Example 12 Except for changing 3 parts of the acid (b1) to 1.5 parts of the acid (b2), an inorganic particle dispersion slurry (12) of the present invention was obtained in the same manner as in Example 11. The number average particle diameter of the inorganic particles (a42) in the inorganic particle dispersion slurry (12) was 20 μm.

[0054] <Comparative Example 1> An attempt was made to prepare a comparative inorganic particle dispersion slurry (13) in the same manner as in Example 1, except that the dispersant (c1) was changed to water (d1). However, the inorganic particles settled, and an inorganic particle dispersion slurry could not be obtained.

[0055] <Comparative Example 2> Except for not using the dispersant (c1), a comparative inorganic particle dispersion slurry (14) was obtained in the same manner as in Example 1. The number average particle diameter of the inorganic particles (a18) in the inorganic particle dispersion slurry (14) was 37 μm.

[0056] <Comparative Example 3> A comparative inorganic particle dispersion slurry (15) was obtained in the same manner as in Example 1, except that the dispersant (c1) was changed to a comparative dispersant (c8). The number average particle diameter of the inorganic particles (a19) in the inorganic particle dispersion slurry (15) was 36 μm.

[0057] <Comparative Example 4> An attempt was made to prepare a comparative inorganic particle dispersion slurry (16) in the same manner as in Example 8, except that the dispersant (c1) was changed to water (d1). However, the inorganic particles aggregated and solidified as a whole, and therefore, an inorganic particle dispersion slurry could not be obtained.

[0058] <Comparative Example 5> A comparative inorganic particle dispersion slurry (17) was obtained in the same manner as in Example 8, except that the dispersant (c1) was changed to the dispersant (c8). The number average particle diameter of the inorganic particles (a23) in the inorganic particle dispersion slurry (17) was 0.18 μm.

[0059] <Comparative Example 6> A comparative inorganic particle dispersion slurry (18) was obtained in the same manner as in Example 10, 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 (18) was 1.1 μm.

[0060] <Comparative Example 7> A comparative inorganic particle dispersion slurry (19) was obtained in the same manner as in Example 10, except that the dispersant (c1) was changed to the dispersant (c8). The number average particle diameter of the inorganic particles (a33) in the inorganic particle dispersion slurry (19) was 0.72 μm.

[0061] <Comparative Example 8> A comparative inorganic particle dispersion slurry (20) 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 (a43) in the inorganic particle dispersion slurry (20) was 35 μm.

[0062] <Comparative Example 9> A comparative inorganic particle dispersion slurry (21) was obtained in the same manner as in Example 11, except that the dispersant (c1) was changed to the dispersant (c8). The number average particle diameter of the inorganic particles (a44) in the inorganic particle dispersion slurry (21) was 31 μm.

[0063] <Comparative Example 10> A comparative inorganic particle dispersion slurry (22) 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 (a45) in the inorganic particle dispersion slurry (22) was 34 μm.

[0064] <Comparative Example 11> A comparative inorganic particle dispersion slurry (23) was obtained in the same manner as in Example 12, except that the dispersant (c1) was changed to the dispersant (c8). The number average particle diameter of the inorganic particles (a46) in the inorganic particle dispersion slurry (23) was 31 μm.

[0065] <Liquidity Evaluation 1> The viscosity (mPa·s) of the inorganic particle dispersion slurries (1) to (7) and (10) to (12) prepared in Examples 1 to 7 and 10 to 12, and the inorganic particle slurries (14), (15), and (18) to (23) prepared in Comparative Examples 2, 3, and 6 to 11, was measured using a BM-type viscometer (VISCOMETER TV-20, Toki Sangyo Co., Ltd., 25°C, 60 rpm). Furthermore, the pH of the slurries was measured using a multi-purpose water quality meter (MM-43M, DKK-TOA Corporation, 25°C). The results are shown in the table below.

[0066] [Table 1] "-" means that no inorganic particle dispersed slurry was obtained, and "∞" means that the measurement range (mPa·s) was exceeded.

[0067] <Liquidity Evaluation 2> The viscosity (mPa s) of inorganic particle dispersion slurries (8) and (9) prepared in Examples 8 and 9, and inorganic particle dispersion slurry (17) prepared in Comparative Example 5, was measured using an E-type viscometer (RE80 model, Toki Sangyo Co., Ltd., 25°C, 10 rpm). Furthermore, the pH of the slurries was measured using a multi-purpose water quality meter (MM-43M, DKK-TOA Corporation, 25°C). The results are shown in the table below.

[0068] [Table 2] "-" means that no inorganic particle dispersed slurry was obtained.

[0069] The inorganic particle dispersion slurries prepared in the Examples had superior fluidity compared to the inorganic particle dispersion slurries prepared in the Comparative Examples, even when the pH (25°C) was 1 to 6. The dispersant of the present invention also exhibited superior fluidity when applied to inorganic particle dispersion slurries having a pH (25°C) of 1 to 6.

Claims

1. The composition comprises inorganic particles (A), an acid (B), a dispersant (C), and water (D), pH (25°C) is 1 to 4.5, An inorganic particle dispersion slurry (excluding those containing at least one water-dispersing polymer material or water-soluble nylon having a carbonyloxy bonding group in a linear molecular structure) characterized in that the dispersant (C) contains a polyoxyalkylene compound (Y) represented by formula (1): HO-(EO)p / (PO)q-H (1) EO is an oxyethylene group, PO is an oxypropylene group, p is an integer of 0 to 226, q is an integer of 0 to 172, and the sum of p and q (p+q) is an integer of 30 to 250.

2. 2. The inorganic particle dispersion slurry according to claim 1, wherein the inorganic particles (A) are metal oxides and / or carbon.

3. A dispersant for an inorganic particle dispersion slurry (excluding those containing a polymeric material of at least one water-dispersible polymer having a carbonyloxy-bonding group in a linear molecular structure or a water-soluble nylon) containing inorganic particles (A), an acid (B), a dispersant (C), and water (D), and having a pH (25°C) of 1 to 4.5, A polyoxyalkylene compound represented by formula (1) {HO-[(CH ２ CH ２ O) ｘ -(CH(CH ３ ) CH ２ O) ｙ 〕 ｎ -H (wherein x is 1 to 50, y is 1 to 50, and n is 2 to 25); and polyoxyethylene-polyoxypropylene condensates HO(C) in the form of white flakes and having a cloud point above 100°C. ２ H ４ O) ａ -(C ３ H ６ O) ｂ -(C ２ H ４ O) ｃ Except H. A dispersant characterized by containing HO-(EO)p / (PO)q-H (1) EO is an oxyethylene group, PO is an oxypropylene group, p is an integer of 0 to 226, q is an integer of 1 to 172, and the sum of p and q (p+q) is an integer of 30 to 250.

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