Dispersant, dispersion composition, coating composition, and cured product

Abstract

To provide a dispersion composition which contains an acetate-based organic solvent in a dispersion medium, and achieves low viscosity and superior fluidity even when containing inorganic particles at a high concentration.SOLUTION: A dispersion composition comprises inorganic particles (A), a dispersant, and an organic solvent, wherein the inorganic particles (A) are magnetic inorganic particles, the dispersant includes a dispersant (B) represented by general formula (1), and the organic solvent includes an organic solvent (C) represented by general formula (5) (wherein, A1 to A4 are independently a monovalent polymer moiety (P), -C(=O)OH, -CH2C(=O)OH, or the like, and X1 is a tetravalent organic residue). General formula (5) CH3COO(R10)nR11.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a dispersant, a dispersion composition, a coating composition, and a cured product. [Background technology]

[0002] It has long been known that it is difficult to obtain a stable dispersion composition of inorganic particles at a high concentration when producing a dispersion composition. For example, in a dispersion composition containing fine inorganic particles, the higher the concentration of the inorganic particles, the higher the viscosity (thickness) becomes, making it difficult to remove from a dispersing machine or transport. In addition, if the dispersibility is poor, the viscosity increases (thickening) during storage, making it difficult to use in many cases.

[0003] Therefore, dispersants are generally used to maintain a good dispersion state. Dispersants for inorganic particles have a structure with a site that adsorbs to inorganic particles and a site that has high affinity to the dispersion medium (often an organic solvent is used), and the performance of the dispersant is determined by the balance between these two sites. Various dispersants are known depending on the type of inorganic particles to be dispersed and the type of organic solvent that is the dispersion medium, but dispersants that are soluble in organic solvents and have acidic or basic polar functional groups are generally used. In this case, it is believed that the polar functional groups become the adsorption sites of inorganic particles. For example, the dispersant described in Patent Document 1 is known as a dispersant having a carboxylic acid as an acidic functional group. In addition, the dispersant described in Patent Document 2 is known as a dispersant having an amine as a basic functional group.

[0004] On the other hand, when a dispersion composition or a coating composition is applied or printed on a substrate, if an organic solvent with high dissolving power is used as a component of the dispersion composition or coating composition, the substrate or the underlayer provided on the substrate is dissolved or swelled by the organic solvent, which has a negative effect. One method for avoiding this effect is to use a specific acetate-based organic solvent having a polyether structure or an alkyl group as a dispersion medium for the dispersion composition, thereby reducing the dissolving power for the substrate and suppressing the negative effect on the substrate or the underlayer. However, such acetate-based organic solvents have poor wettability and dispersibility for inorganic particles, so that it was difficult to produce a dispersion composition containing inorganic particles at a high concentration using conventional dispersants. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-029901 A [Patent Document 2] Special Publication No. 08-507960 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a dispersion composition which contains an acetate-based organic solvent as a dispersion medium and has low viscosity and excellent fluidity even when it contains a high concentration of inorganic particles. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. That is, the present invention relates to a dispersion composition comprising inorganic particles (A), a dispersant, and an organic solvent, wherein the dispersant comprises a dispersant (B) having a structure represented by the following general formula (1), and the organic solvent comprises an organic solvent (C) having a structure represented by the following general formula (5).

[0008] [ka]

[0009] [In general formula (1), A 1 ~A 4 is a combination selected from the group consisting of the following (A), (B), and (C), (A): A 1 ~A 4 Among these, two moieties are the same or different monovalent polymer moieties (P), and the other two moieties are the same or different -C(=O)OH or -CH2 C(=O)OH. (B): A 1 ~A 4 One of the moieties is a monovalent polymer moiety (P), and the other three moieties are -C(=O)OH or -CHC(=O)OH which may be the same or different. (C):A 1 ~A 4 One of the moieties is a monovalent polymer moiety (P), and the other two moieties are -C(=O)OH or -CH2C(=O)OH, which may be the same or different from each other; Another site is -C(=O)-Xa-Ra (where Xa is -O- or N(Ra 2 )-. Ra is a group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms, Ra 2 is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 2 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms; the monovalent polymer moiety (P) is a cyclic ester polymer moiety having a terminal moiety A, the terminal moiety A having a structure derived from a monoalcohol having a molecular weight of 300 or less and containing an aromatic ring or an alkyleneoxy unit, X 1is a tetravalent group represented by the following general formula (2), general formula (3), or general formula (4): .〕

[0010] [ka]

[0011] [In the general formula (2), k represents an integer of 1 or 2. * represents a bond.] [In general formula (3), R 2 is a direct bond, -CH2-, -O-, -C(=O)-, -C(=O)OCH2CH2OC(=O)-, -C(=O)OCH(OC(=O)CH3)CH2OC(=O)-, -SO2-, -C(CF3)2-, formula:

[0012] [ka]

[0013] The symbol * represents a bond. [The total number of carbon atoms in the group represented by formula (4) is 4 to 20, In general formula (4), R 3 is a direct bond, -O-, or a divalent hydrocarbon group having 1 to 8 carbon atoms It is based on R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are each independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are bonded together to form a ring may be formed. General formula (5) CH3COO(R 10 ) n R 11 In the general formula (5), n represents an integer of 1 to 10. 10 represents an oxyalkylene group, and R 11 represents an alkyl group.

[0014] The present invention also relates to the above dispersion composition, which contains 70 to 100 mass % of the above organic solvent (C) based on 100 mass % of the above organic solvent.

[0015] In addition, the present invention relates to a compound represented by the general formula (5), 10 is an oxyethylene group or an oxy(iso)propylene group.

[0016] In addition, the present invention relates to a compound represented by the general formula (5), 11 is an unsubstituted alkyl group having 2 to 4 carbon atoms.

[0017] The present invention also relates to the above dispersion composition, wherein the terminal moiety A has a structure derived from a monoalcohol having a molecular weight of 300 or less and containing an aromatic ring unit.

[0018] The present invention also provides X 1 is a tetravalent group represented by general formula (3) or general formula (4). The present invention relates to the above-mentioned dispersion composition.

[0019] The present invention also relates to the above dispersion composition, wherein the cyclic ester polymer portion has a structural unit derived from caprolactone or valerolactone.

[0020] The present invention also relates to the dispersion composition, wherein the dispersant (B) has an acid value of 25 to 200 mgKOH / g.

[0021] The present invention also relates to the above dispersion composition, wherein the dispersant (B) has a weight average molecular weight of 1,000 to 50,000.

[0022] In the present invention, the inorganic particles (A) are inorganic particles containing 1 mass % or more of Fe. Concerning the composition.

[0023] The present invention also relates to the above dispersion composition, wherein the inorganic particles (A) have an average primary particle size of 0.5 to 100 μm.

[0024] The present invention also relates to a coating composition comprising the dispersion composition according to any one of claims 1 to 11 and a binder component (D). Regarding.

[0025] The present invention also relates to a cured product of the coating composition according to claim 12. Regarding.

[0026] The present invention also relates to a dispersant for inorganic particles having a structure represented by the following general formula (7):

[0027] [ka]

[0028] [In general formula (7), A 5 ~A 8 is a combination selected from the group consisting of the following (A2), (B2) and (C2), (A2):A 5 ~A 8 Among these, two moieties are monovalent polymer moieties (P2) which may be the same or different from each other, and the other two moieties are -C(=O)OH or CH2C(=O)OH which may be the same or different from each other. (B2):A 5 ~A 8 One of the moieties is a monovalent polymer moiety (P2), and the other three moieties are -C(=O)OH or CH2C(=O)OH which may be the same or different from each other. (C2):A 5 ~A 8 one of the moieties is a monovalent polymer moiety (P2), and the other two moieties are the same or different -C(=O)OH or CH2C(=O)OH; Another site is -C(=O)-Xb-Rb (where Xb is -O- or N(Rb 2 )-. Rb is a group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms, Rb 2 is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 2 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms; the monovalent polymer moiety (P2) is a cyclic ester polymer moiety having a terminal moiety A2, the terminal moiety A2 being a structure derived from a monoalcohol containing an aromatic ring unit and having a molecular weight of 300 or less, the cyclic ester polymer moiety being a polymer having a structure derived from caprolactone or valerolactone, X 3 is a tetravalent group represented by the following general formula (8), general formula (9), or general formula (10): ]

[0029] [ka]

[0030] [In the general formula (8), k' represents an integer of 1 or 2. * represents a bond.] [In general formula (9), R 12 is a direct bond, -CH2-, -O-, -C(=O)-, -C(= O)OCH2CH2OC(=O)-, -C(=O)OCH(OC(=O)CH3)CH2OC(=O)-, -SO2-, -C(CF3)2-, formula:

[0031] [ka]

[0032] The symbol * represents a bond. [The total number of carbon atoms in the group represented by formula (10) is 4 to 20, In general formula (10), R 13 is a direct bond, -O-, or a divalent hydrocarbon group having 1 to 8 carbon atoms, R 14 , R 15 , R 16 , R 17 , R 18 and R 19 are each independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms; R 13 , R 14 , R 15 , R 16 , R 17 , R 18 and R 19 may be bonded to each other to form a ring. Effect of the Invention

[0033] According to the present invention, even when an acetate-based organic solvent is used as a dispersion medium, it is possible to obtain a dispersion composition containing inorganic particles at a high concentration, having a low viscosity and excellent fluidity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The terms used in this specification are defined. Unless otherwise specified, "(meth)acryloyl", "(meth)acryl", "(meth)acrylic acid", "(meth)acrylate", or "(meth)acrylamide" respectively mean "acryloyl and / or methacryl", "acrylic and / or methacrylic", "acrylic acid and / or methacrylic acid", "acrylate and / or methacrylate", or "acrylamide and / or methacrylamide". In addition, in this specification, a numerical range specified by "~" includes the numerical values ​​before and after "~" as the lower and upper limit ranges.

[0035] <Dispersion composition> The dispersion composition of the present invention (hereinafter also referred to as "the composition") comprises inorganic particles (A), a dispersant and an organic solvent, the dispersant comprises a dispersant (B) having a structure represented by general formula (1), and the organic solvent comprises an organic solvent (C) having a structure represented by general formula (5). This composition can be used as a coating composition by further blending a binder component (D). For example, when thermally conductive inorganic particles are selected as the inorganic particles (A), it can be used as a thermally conductive coating, when conductive inorganic particles are selected as the inorganic particles (A), it can be used as a conductive coating, and when magnetic inorganic particles are selected as the inorganic particles (A), it can be used as a magnetic coating. Each of the constituent materials constituting the present composition will now be described in detail.

[0036] <Inorganic particles (A)> First, the inorganic particles (A) contained in the dispersion composition of the present invention will be described. The inorganic particles (A) are particles composed of an inorganic material, and examples of the inorganic particles include metal particles, metal alloy particles, metal oxide particles, carbon material particles, etc. The inorganic particles (A) may further have a coating layer on the surface of the particles.

[0037] The shape of the inorganic particles (A) is not particularly limited, but may be, for example, spherical particles such as spherical particles and ellipsoidal particles, or non-spherical particles such as flake-shaped, scale-shaped, and filament-shaped particles. Among these, spherical particles are preferred. By using spherical particles, it is possible to obtain a cured product with good particle packing properties.

[0038] The sphericity of the inorganic particles (A) is preferably 0.5 to 1.2, more preferably 0.7 to 1.2, and particularly preferably 0.8 to 1.1. The sphericity can be calculated from a magnified image obtained by a scanning electron microscope. An arbitrary particle is selected from the magnified image obtained by a scanning electron microscope, and the projected area (A) and perimeter (M) of the particle are measured. When a true sphere having this perimeter (M) is assumed, the radius (r) = M / 2π is used to calculate the area (B) of the true sphere = π × (M / 2π). 2The sphericity (A / B) is calculated from the areas A and B thus measured and calculated. The sphericity of 20 particles is measured, and the average value is regarded as the sphericity.

[0039] The aspect ratio of the inorganic particles (A) is not particularly limited, but is preferably 0.5 to 5, more preferably 0.5 to 3, and even more preferably 0.7 to 1.5. When the aspect ratio is 5 or less, the particles can be easily packed. Also, when the aspect ratio is 0.5 or more, the particles can be obtained industrially at low cost.

[0040] The coating layer on the particle surface of the inorganic particles (A) is preferably a coating layer containing a compound containing at least one element selected from the group consisting of phosphorus, silicon, aluminum and titanium. Such a coating layer can be prepared by a method such as adsorption treatment of a phosphorus compound, adsorption treatment of a silicone compound, or by reacting an organosilicon compound and / or a coupling agent alone or with each other on the particle surface of the inorganic particles (A).

[0041] Examples of the organosilicon compound include tetraalkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane; Alkoxysilane compounds having a vinyl group, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinylmethyldimethoxysilane, and vinylmethyldiethoxysilane; Examples of the suitable coupling agents include silane coupling agents having a functional group such as an amino group, an epoxy group, a mercapto group, or a carboxyl group.

[0042] Examples of the coupling agent include various coupling agents such as titanate-based coupling agents, aluminum-based coupling agents, and zirconium-based coupling agents.

[0043] As one embodiment (first embodiment) of the inorganic particles (A), it is preferable to use, as the inorganic particles (A1), at least one type of inorganic particles selected from the group consisting of metal particles, metal alloy particles, and metal oxide particles. In one embodiment (second embodiment) of the inorganic particles (A), carbon material particles are preferably used as the inorganic particles (A2).

[0044] The first embodiment will be described in detail below. In the first embodiment, the average primary particle diameter of the inorganic particles (A1) is preferably 0.2 to 100 μm, more preferably 0.5 to 100 μm, even more preferably 0.5 to 50 μm, even more preferably 0.5 to 30 μm, even more preferably 0.5 to 10 μm, and particularly preferably 1 to 10 μm. By setting the average primary particle diameter within this range, it is possible to obtain a dispersion composition that is highly concentrated and has good handleability. In addition, the average primary particle diameter in this specification refers to the median diameter measured by an electron microscope for 50 random particles.

[0045] The specific surface area of ​​the inorganic particles (A1) is 0.01 to 10 m 2 / g, preferably 0. 01~5m 2 / g is more preferable, and 0.05 to 3m 2 / g is more preferable, and 0.1 to 1m 2 The specific surface area is particularly preferably 1 / g. This can be calculated using the BET multipoint method.

[0046] The inorganic particles (A1) are preferably inorganic particles containing 1 mass % or more of Fe. The Fe content in the inorganic particles (A1) is preferably 69 to 100 mass %, more preferably 69 to 98 mass %, and further preferably 80 to 98 mass %.

[0047] The content of the inorganic particles (A1) in the composition is preferably from 60 to 98 mass%, more preferably from 70 to 98 mass%, further preferably from 80 to 98 mass%, and particularly preferably from 85 to 98 mass%.

[0048] The content of the inorganic particles (A1) in the inorganic particles (A) is preferably from 10 to 100 mass%, more preferably from 20 to 100 mass%, further preferably from 50 to 100 mass%, and particularly preferably from 70 to 100 mass%.

[0049] By blending the inorganic particles (A1) in a high concentration in the dispersion composition, the properties derived from the inorganic particles (A1), such as thermal conductivity, electrical conductivity, and magnetism, can be highly exhibited.

[0050] Examples of materials constituting the inorganic particles (A1) include metal particles such as iron powder and carbonyl iron particles; metal alloy particles such as iron-silicon alloy particles, iron-chromium alloy particles, iron-manganese alloy particles, iron-silicon-aluminum alloy particles, and iron-silicon-chromium alloy particles; and metal oxide particles such as iron oxide.

[0051] The second embodiment will be described in detail below. In the second embodiment, the average primary particle size of the inorganic particles (A2) is preferably from 0.01 to 0.10 μm, more preferably from 0.01 to 0.04 μm, and even more preferably from 0.01 to 0.03 μm.

[0052] The specific surface area of ​​the inorganic particles (A2) is 50 to 200 m 2 / g, and preferably 80 to 150m 2 / g is more preferable, and 80 to 120m 2 It is particularly preferred that The specific surface area can be calculated by the nitrogen gas adsorption method using the BET multipoint method.

[0053] Examples of the constituent material of the inorganic particles (A2) include carbon materials such as carbon black, graphite, carbon nanotubes, etc. In addition, it is preferable that the inorganic particles (A2) do not substantially contain transition metal elements such as Fe within the particles.

[0054] The content of the inorganic particles (A2) in the present composition is preferably from 1 to 50 mass %, more preferably from 10 to 40 mass %, and even more preferably from 15 to 40 mass %.

[0055] <Dispersant (B)> Next, the dispersant (B) contained in the dispersion composition of the present invention will be described. The dispersant (B) is a dispersant represented by the general formula (1) and contains a tetravalent group X 1 And those four Group A as a Substituent 1 ~A 4 and a tetravalent group X 1 Formula (2), Formula (3) or a tetravalent group represented by general formula (4).

[0056] Substituent A 1 ~A 4 The combination of A combination selected from the group consisting of (A), (B) and (C) above, 1 ~A 4 A combination in which two of the moieties are the same or different monovalent polymer moieties (P) and the other two moieties are -C(=O)OH or CH2C(=O)OH is preferred. , A 1 ~A 4 A more preferred combination is one in which two of the moieties are the same or different monovalent polymer moieties (P) and the other two moieties are -C(=O)OH.

[0057] <Polymer part (P)> The polymer portion (P) is a cyclic ester polymer portion having a terminal portion A, which is a structure derived from a monoalcohol containing an aromatic ring or an alkyleneoxy unit and having a molecular weight of 300 or less. Since the terminal portion A has an aromatic ring or an alkyleneoxy unit, it is considered that the affinity to the solvent is high and aggregation can be suppressed. As a result, the dispersion composition of the present invention has high stability during storage at low temperatures and can obtain high stability over time when inorganic particles (A) are dispersed at a high concentration.

[0058] The weight average molecular weight of the polymer portion (P) is preferably 400 to 10,000, more preferably 600 to 8,000, and even more preferably 800 to 4,000. When the molecular weight is 400 or more, the aggregation of the inorganic particles (A) can be prevented by the steric repulsion effect of the solvent affinity portion. When the molecular weight is 10,000 or less, the solvent solubility is ensured and a sufficient steric repulsion effect can be maintained. When it is within the above range, the effect of inhibiting the aggregation of the inorganic particles (A) by the steric repulsion effect becomes better.

[0059] Here, the polymer portion (P) is a cyclic ester polymer portion. The molecular weight of these can be easily adjusted to the above range, and the affinity to organic solvents is also good. In order to suppress adverse effects on dispersibility, it is preferable that the polymer portion (P) is substantially free of hydroxyl groups, primary amino groups, secondary amino groups, and thiol groups (also called sulfanyl groups or mercapto groups).

[0060] <Tetravalent group X 1 > Tetravalent group X 1 is a structure represented by the above general formula (2), general formula (3) or general formula (4). From the viewpoint of reducing the viscosity and preservation stability of the dispersion composition or coating composition, 1 is preferably a tetravalent group represented by general formula (3) or general formula (4), It is more preferably a tetravalent group represented by the general formula (4).

[0061] Tetravalent group X 1is a group represented by general formula (2), k is preferably 1. .

[0062] Tetravalent group X 1 is a group represented by general formula (3), R 2 is a direct bond, -C(=O)-, -C(=O)OCH2CH2OC(=O)-, -SO2-, or the formula:

[0063] [ka] It is preferable that the group is represented by the following formula:

[0064] A tetravalent group X represented by the general formula (4) 1 Preferred embodiments of the above include, for example, the following groups: It can be done.

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] In addition, a preferred embodiment of the tetravalent group represented by the general formula (4) is a group having a total of 4 to 20 carbon atoms, 3 is a direct bond, -O - or a divalent or trivalent hydrocarbon group having 1 to 8 carbon atoms, R 4 , R 5 , R 6 ,oh YobiR 9 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, Or, R 4 and R 6 and / or R 5 and R 9 may be directly bonded to form an unsaturated double bond, R 7 and R 8 are each independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, or R 7 and R 8 and a cyclic group X formed by a direct bond or a divalent hydrocarbon group having 1 to 8 carbon atoms. 2 or R 3 and R 7 or R 3 and R 8 and carbon atoms A trivalent hydrocarbon group having a number of 1 to 8 is formed to form a cyclic group X 2 or R 3 and R 7 and R 8 and form a tetravalent hydrocarbon group having 1 to 8 carbon atoms, 2 An example of an embodiment in which the above may be formed is given.

[0072] A preferred embodiment of the dispersant (B) is a dispersant having a structure represented by general formula (7). In general formula (7): A 5 ~A 8 is A in general formula (1). 1 ~A 4 are synonymous with each other. The combinations (A2), (B2) and (C2) have the same meanings as the combinations (A), (B) and (C) in the general formula (1), respectively. Xb, Rb and Rb 2 represents Xa, Ra and Ra in general formula (1). 2 are synonymous with each other. The monovalent polymer moiety (P2) is a cyclic ester polymer moiety having a terminal moiety A2, and the terminal moiety A2 has a structure derived from a monoalcohol having a molecular weight of 300 or less and containing an aromatic ring unit, and the cyclic ester polymer moiety is a polymer having a structure derived from caprolactone or valerolactone. X 3 represents X in general formula (1). 1 The tetravalent groups represented by general formulae (8), (9) and (10) are synonymous with the tetravalent groups represented by general formulae (2), (3) and (4), respectively.

[0073] In the general formula (8), k' has the same meaning as k in the general formula (2). R in general formula (9) 12 is R in general formula (3). 2 is synonymous with. R in general formula (10) 13 , R 14 , R 15 , R 16 , R 17 , R 18 and R 19 is R in general formula (4). 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are synonymous with each other.

[0074] The terminal moiety A2 of the monovalent polymer moiety (P2) is preferably a structure derived from a secondary hydroxyl group-containing monoalcohol or a primary hydroxyl group-containing monoalcohol, more preferably a structure derived from a primary hydroxyl group-containing monoalcohol, even more preferably a structure derived from benzyl alcohol or phenoxyethanol, and particularly preferably a structure derived from benzyl alcohol.

[0075] The cyclic ester polymer moiety of the monovalent polymer moiety (P2) is a polymer having a structure derived from caprolactone or valerolactone as a cyclic compound, and is preferably a polymer having a structure derived from caprolactone as the main component of the cyclic ester polymer moiety. The content in the cyclic compound is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and particularly preferably substantially 100% by mass. The preferred embodiments of the general formula (7) other than the polymer moiety (P2) are the same as the preferred embodiments of the general formula (1) other than the polymer moiety (P).

[0076] The acid value of the dispersant (B) is preferably 25 to 200 mgKOH / g, more preferably 25 to 150 mgKOH / g, further preferably 25 to 120 mgKOH / g, and particularly preferably 30 to 100 mgKOH / g. By having an acid value of 25 to 200 mgKOH / g, the dispersibility of the particles, the dispersion stability over time, and the storage stability of the paste are improved.

[0077] The amine value of the dispersant (B) is preferably from 0 to 40 mgKOH / g, more preferably from 0 to 30 mgKOH / g, further preferably from 0 to 10 mgKOH / g, and particularly preferably substantially 0 mgKOH / g.

[0078] The hydroxyl value of the dispersant (B) is preferably from 0 to 30 mgKOH / g, more preferably from 0 to 10 mgKOH / g, and further preferably substantially 0 mgKOH / g.

[0079] The weight average molecular weight of the dispersant (B) is preferably from 1,000 to 50,000, more preferably from 2,000 to 50,000, further preferably from 2,000 to 20,000, and particularly preferably from 2,000 to 10,000.

[0080] The number average molecular weight of the dispersant (B) is preferably from 1,000 to 50,000, more preferably from 1,500 to 30,000, further preferably from 1,500 to 15,000, and particularly preferably from 1,500 to 7,000.

[0081] The water content of the dispersant (B) is preferably 0 to 1 mass%, more preferably 0 to 0.5 mass%, further preferably 0 to 0.3 mass%, and particularly preferably 0 to 0.1 mass%, based on 100 mass% of the dispersant (B). By controlling the water content to a range of 1 mass% or less, it is possible to suppress deterioration due to insufficient dissolution of the binder component (D) or hydrolysis, etc.

[0082] In the first embodiment using inorganic particles (A1), the amount of the dispersant (B) relative to 100 mass% of the inorganic particles (A) is preferably 0.1 to 3 mass%, more preferably 0.1 to 1.5 mass%, and even more preferably 0.1 to 1 mass%.

[0083] In the second embodiment using inorganic particles (A2), the amount of the dispersant (B) relative to 100 mass% of the inorganic particles (A) is preferably 1 to 20 mass%, more preferably 3 to 20 mass%, and further preferably 5 to 15 mass%.

[0084] <Method of manufacturing dispersant> Next, a method for producing the dispersant (B) will be described. It is needless to say that the method for producing is not limited to the following. The synthesis of the dispersant (B) is preferably carried out, for example, by the following first and second steps. (First step) A process for producing a "cyclic ester polymer moiety (APOH) having a terminal moiety A and a hydroxyl group at the other terminal."

[0085] (Second step) A step of reacting the polymer (APOH) obtained in the first step with a tetracarboxylic dianhydride. Here, the moiety obtained by removing one hydrogen atom of a hydroxyl group from the polymer (APOH) is represented by the general formula (1), 1 ~A 4 The tetracarboxylic dianhydride constitutes a monovalent polymer moiety (P) which is one or two of the X 1 Configure do.

[0086] First, the first step will be described in detail. In the method for producing dispersant (B), in the first step, a "cyclic ester polymer moiety (APOH) having a terminal moiety A and a hydroxyl group at the other terminal" is obtained by ring-opening polymerization of a cyclic compound using a monoalcohol compound containing an aromatic ring or an alkyleneoxy unit as an initiator.

[0087] Examples of monoalcohols containing an aromatic ring and having a molecular weight of 300 or less include primary hydroxyl group-containing monoalcohols such as benzyl alcohol, phenoxyethanol, paracumylphenoxyethyl alcohol, piperonyl alcohol, and 1-naphthalenemethanol; and secondary hydroxyl group-containing monoalcohols such as benzhydrol, 1-hydroxyindan, and 1-phenyl-1-propanol. Among these, primary hydroxyl group-containing monoalcohols are preferred, benzyl alcohol or phenoxyethanol are more preferred, and benzyl alcohol is even more preferred.

[0088] Examples of monoalcohols having a molecular weight of 300 or less containing an alkyleneoxy unit include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monohexyl ether, propylene glycol mono-2-ethylhexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol mono-2-ethylhexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, and dipropylene glycol monobutyl ether. ether, dipropylene glycol monohexyl ether, dipropylene glycol mono-2-ethylhexyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, triethylene glycol monohexyl ether, triethylene glycol mono-2-ethylhexyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, tripropylene glycol monobutyl ether, tripropylene glycol monohexyl ether, tripropylene glycol mono-2-ethylhexyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monopropyl ether, tetraethylene glycol monobutyl ether, tetraethylene glycol monohexyl ether, tetraethylene glycol mono-2-ethylhexyl ether, tetrapropylene glycol monomethyl ether,Examples of the alkylene glycol monoalkyl ether include tetrapropylene glycol monoethyl ether, tetrapropylene glycol monopropyl ether, tetrapropylene glycol monobutyl ether, tetrapropylene glycol monohexyl ether, tetrapropylene glycol mono-2-ethylhexyl ether, and tetradiethylene glycol monomethyl ether. Among these, diethylene glycol monomethyl ether, diethylene glycol monopropyl ether, and diethylene glycol monobutyl ether are preferred. In this specification, the monoalcohol having a molecular weight of 300 or less and containing an alkyleneoxy unit refers to one other than the monoalcohol having a molecular weight of 300 or less and containing an aromatic ring.

[0089] The monoalcohols used in the production of the dispersant (B) can be used either alone or in combination of two or more kinds.

[0090] Examples of cyclic compounds used in the synthesis of the cyclic ester polymer portion (APOH) include alkylene oxides, lactones, lactides, dicarboxylic anhydrides, and epoxides. Among these, from the viewpoint of dispersibility, it is preferable to use lactones or lactides, it is more preferable to use lactones, and it is even more preferable to use lactones alone.

[0091] As the alkylene oxide, ethylene oxide, propylene oxide, 1,2-, 1,4-, 2,3- or 1,3-butylene oxide can be used, and two or more of these can be used in combination. When two or more alkylene oxides are used in combination, the alkylene oxide may form either a random copolymer and / or a block copolymer. The polymerization mole number of the alkylene oxide per mole of the initiator is preferably 0 to 100.

[0092] The polymerization of alkylene oxide can be easily carried out, for example, in the presence of an alkali catalyst at a temperature of 100 to 200° C. under pressure. Polymers (PeOH) obtained by polymerizing alkylene oxide to the hydroxyl group of a monoalcohol are commercially available, such as NOF Corp.'s Uniox series and NOF Corp.'s Blemmer series, and these polymers (PeOH) can be used as the cyclic ester polymer moiety (APOH) in the production of the dispersant (B). Examples of such commercially available products include Uniox M-400, M-550, M-2000, Blenmar PE-90, PE-200, PE-350, AE-90, AE-200, AE-400, PP-1000, PP-500, PP-800, AP-150, AP-400, AP-550, AP-800, 50PEP-300, 70PEP-350B, AEP series, 55PET-400, 30PET-800, 55PET-800, AET series, 30PPT-800, 50PPT-800, 70PPT-800, APT series, 10PPB-500B, 10APB-500B, etc. In the present specification, the first step may be omitted by using these commercially available products.

[0093] Examples of lactones include β-butyrolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, δ-caprolactone, ε-caprolactone, alkyl-substituted ε-caprolactone, etc. Among these, the use of δ-valerolactone, ε-caprolactone, and alkyl-substituted ε-caprolactone is preferred in terms of ring-opening polymerizability, and the use of ε-caprolactone is more preferred in terms of dispersant function.

[0094] In the dispersant (B), the lactones that can be used are not limited to those exemplified above, and they may be used alone or in combination of two or more kinds.

[0095] As the lactide, those represented by the following general formula (6) are preferred (including glycolide): ).

[0096] [ka] [In general formula (6), R 31 and R 32 are each independently a hydrogen atom or a saturated or unsaturated linear or branched alkyl group having 1 to 20 carbon atoms; R 33 and R 34 are each independently a hydrogen atom, a halogen atom, or a saturated or unsaturated, straight-chain or branched lower alkyl group having 1 to 9 carbon atoms. Examples of lactides include lactide (3,6-dimethyl-1,4-dioxane-2,5-dione) and glycolide (1,4-dioxane-2,5-dione).

[0097] The ring-opening polymerization of lactone and / or lactide can be carried out, for example, by charging an initiator, lactone and / or lactide, and a polymerization catalyst into a reactor connected to a dehydration tube and a condenser, and heating under a nitrogen stream. When a monoalcohol having a low boiling point is used as the monoalcohol that forms the terminal moiety A, the reaction can be carried out under pressure using an autoclave. When a monoalcohol having an ethylenically unsaturated double bond is used as the monoalcohol that forms the terminal moiety A, it is preferable to add a polymerization inhibitor and carry out the reaction under a dry air stream.

[0098] The number of moles of lactone and / or lactide polymerized per mole of the initiator is preferably in the range of 1 to 60 moles, more preferably 2 to 20 moles, and even more preferably 3 to 15 moles.

[0099] Examples of the polymerization catalyst include quaternary ammonium salts such as tetramethylammonium chloride, tetrabutylammonium chloride, tetramethylammonium bromide, tetrabutylammonium bromide, tetramethylammonium iodide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium iodide; tetramethylphosphonium chloride, tetrabutylphosphonium chloride, tetramethylphosphonium bromide, tetrabutylphosphonium bromide, and tetramethylphosphonium; Quaternary phosphonium salts such as iodine, tetrabutylphosphonium iodine, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium bromide, benzyltrimethylphosphonium iodine, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, and tetraphenylphosphonium iodine; organic tin compounds such as monomethyltin oxide, monobutyltin oxide, monooctyltin oxide, dibutyltin oxide, and dioctyltin dilaurate; phosphorus compounds such as triphenylphosphine, potassium acetate, sodium acetate, potassium benzoate, and benzoic acid. Examples of the catalyst include organic carboxylates such as sodium carbonate, alkali metal alcoholates such as sodium alcoholate and potassium alcoholate, tertiary amines, organic aluminum compounds, organic titanate compounds, zinc compounds such as zinc chloride, etc. The amount of the catalyst used is 0.1 ppm to 3000 ppm, preferably 1 ppm to 1000 ppm, based on the mass of the lactone and / or lactide. When this mass range is satisfied, a polymer without coloring is easily obtained at a polymerization rate suitable for production.

[0100] The polymerization temperature of lactone and / or lactide is preferably 70 to 240° C., more preferably 100 to 220° C., and even more preferably 110 to 210° C. If this temperature range is satisfied, a polymer with fewer by-products can be easily obtained at a polymerization rate suitable for production.

[0101] Examples of the dicarboxylic acid anhydride include succinic anhydride, maleic anhydride, phthalic anhydride, itaconic anhydride, glutaric anhydride, dodecenylsuccinic anhydride, and chlorendec anhydride.

[0102] Examples of epoxides include methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, phenyl glycidyl ether, p-tertiary butylphenyl glycidyl ether, 2,4-dibromophenyl glycidyl ether, 3-methyl-dibromophenyl glycidyl ether (however, the substitution position of the bromo is optional), allyl glycidyl ether, ethoxyphenyl glycidyl ether, glycidyl (meth)acrylate, glycidyl phthalimide, and styrene oxide.

[0103] Here, the order of reaction of the cyclic compounds is arbitrary. For example, after the alkylene oxide is polymerized with the above initiator in the first stage, lactone is polymerized in the second stage, and dicarboxylic anhydride and epoxide are polymerized alternately in the third stage. In this example, the initiator when lactone is polymerized in the second stage is an alkylene oxide polymer having a hydroxyl group at one end polymerized in the first stage. In addition, the initiator when dicarboxylic anhydride and epoxide are polymerized alternately in the third stage is a block copolymer of an alkylene oxide polymer having a hydroxyl group at one end polymerized up to the second stage and a lactone polymer.

[0104] The reaction order of the cyclic compounds is not limited to the combination of alkylene oxide in the first step, lactone in the second step, and dicarboxylic anhydride and epoxide in the third step, and the combination of alkylene oxide, lactone (and / or lactide), and dicarboxylic anhydride and epoxide can be carried out in any order, one or more times. Alternatively, for the combinations of alkylene oxide, lactone (and / or lactide), and dicarboxylic anhydride and epoxide, ring-opening polymerization can be carried out by selecting any cyclic compound from them without carrying out ring-opening polymerization for all of them.

[0105] When a cyclic ester polymer portion (APOH) is produced using a dicarboxylic anhydride and an epoxide, the dicarboxylic anhydride and the epoxide are used simultaneously with an initiator (monoalcohol forming the terminal portion A) and react alternately. At this time, the acid anhydride group of the dicarboxylic anhydride first reacts with the hydroxyl group of the initiator to generate a carboxyl group, and then the epoxy group of the epoxide reacts with this carboxyl group to generate a hydroxyl group. Furthermore, the acid anhydride group of the dicarboxylic anhydride reacts with this hydroxyl group, and the same reactions as above can be carried out in sequence. The polymerization mole numbers of the dicarboxylic anhydride and the epoxide per mole of the initiator are preferably 0 to 30 moles, respectively. The reaction ratio ([D] / [E]) of the dicarboxylic anhydride and the epoxide is, 0.8≦[D] / [E]≦1.0 (where [D] is the number of moles of dicarboxylic anhydride, and [E] is the number of moles of epoxide). When this range is satisfied, the polymerization reaction can proceed effectively.

[0106] The alternating polymerization of dicarboxylic anhydride and epoxide is preferably carried out in the range of 50° C. to 180° C., more preferably 60° C. to 150° C. If the reaction temperature is less than 50° C. or more than 180° C., the reaction rate is extremely slow.

[0107] In this specification, the monovalent polymer moiety (P) is, as described above, composed of a moiety obtained by removing one hydrogen atom of a hydroxyl group from the polymer (APOH).

[0108] In terms of the simplicity of the production process, ease of molecular weight control, and high reaction rate, the cyclic ester polymer moiety (APOH) is preferably a cyclic compound that uses lactone and / or lactide as the main component, and more preferably uses lactone as the main component. The content in the cyclic compound is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and particularly preferably substantially 100% by mass.

[0109] In the first step of producing the polymer (APOH), a solvent can be used. Examples of the solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, toluene, xylene, acetonitrile, and organic solvent (C). Two or more of these solvents may be mixed and used. After the reaction is completed, the solvent used can be removed by an operation such as distillation, or can be used as it is as a part of the dispersant product.

[0110] Next, the second step of reacting the "cyclic ester polymer moiety (APOH) having a terminal moiety A and a hydroxyl group at the other terminal" with a tetracarboxylic dianhydride will be described.

[0111] In the second step, the hydroxyl group of the "cyclic ester polymer moiety (APOH) having a terminal moiety A and a hydroxyl group at the other terminal" obtained in the first step is reacted with the carboxylic anhydride group of the tetracarboxylic dianhydride. By this second step, a dispersant (B) having a structure represented by general formula (1) can be obtained.

[0112] Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, and polycyclic tetracarboxylic dianhydrides.

[0113] Examples of the aliphatic tetracarboxylic dianhydride include 1,2,3,4-butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 2,3,5,6-tetracarboxycyclohexane dianhydride, 2,3,5,6-tetracarboxynorbornane dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and bicyclo[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride. The aliphatic tetracarboxylic dianhydride is 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, or 2,3,4,5-tetrahydrofurantetracarboxylic acid. Acid dianhydrides are preferred, and 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride are more preferred.

[0114] Examples of aromatic tetracarboxylic acid anhydrides include pyromellitic dianhydride, ethylene glycol ditrimellitic anhydride, propylene glycol ditrimellitic anhydride, butylene glycol ditrimellitic anhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 2,2',3,3'-benzophenone tetracarboxylic acid dianhydride, 3,3',4,4'-biphenylsulfone tetracarboxylic acid dianhydride, 2,2',3,3'-biphenylsulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic acid dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic acid dianhydride, 3,3',4,4'-tetraphenylsilane tetracarboxylic acid dianhydride, 1,2,3,4-furan tetracarboxylic acid dianhydride, 4,4'-Bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride Examples of such anhydride include p-phenylene-bis(triphenylphthalic) dianhydride, M-phenylene-bis(triphenylphthalic) dianhydride, bis(triphenylphthalic)-4,4'-diphenyl ether dianhydride, bis(triphenylphthalic)-4,4'-diphenylmethane dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, and 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene anhydride.

[0115] Examples of the polycyclic tetracarboxylic acid anhydride include 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride and 3,4-dicarboxy-1,2,3,4-tetrahydro-6-methyl-1-naphthalene succinic dianhydride.

[0116] The tetracarboxylic dianhydride used in the second step is not limited to the compounds exemplified above, and may have any structure as long as it has two carboxylic anhydride groups. These may be used alone or in combination. From the viewpoint of solubility in the organic solvent (C) and low viscosity of the dispersion composition, it is preferable that the compound has a tetravalent group represented by general formula (3) or general formula (4), and it is particularly preferable that the compound has a tetravalent group represented by general formula (4).

[0117] The reaction ratio in the second step is the moles of hydroxyl groups in the polymer (APOH). <h>, the number of moles of carboxylic anhydride groups of the tetracarboxylic dianhydride <n>When 0.5< <h> / <n><1.2 is preferable, and 0.7< <h> / <n><1.1, most preferably <h> / <n>=1. <h> / <n>When the reaction is carried out at <1, the remaining carboxylic acid anhydride group may be hydrolyzed with a required amount of water before use.

[0118] A catalyst may be used in the second step. The catalyst may be a tertiary amine compound, such as triethylamine, triethylenediamine, N,N-dimethylbenzylamine, N-methylmorpholine, 1,8-diazabicyclo-[5.4.0]-7-undecene, or 1,5-diazabicyclo-[4.3.0]-5-nonene.

[0119] The second step may be carried out without a solvent or with a suitable dehydrated organic solvent. After the reaction is completed, the solvent used in the reaction may be removed by an operation such as distillation, or may be dispersed as it is. It may also be used as part of a pharmaceutical product.

[0120] The reaction temperature in the second step is preferably in the range of 80°C to 180°C, more preferably 90°C to 160°C.

[0121] <Organic solvent (C)> Next, the organic solvent (C) contained in the dispersion composition of the present invention will be described. The organic solvent (C) is an organic solvent having a structure represented by general formula (5). In the present invention, the organic solvent (C) is preferably a main component of the organic solvent contained in the present composition. Here, the organic solvent is an organic compound that is liquid at 25°C under normal pressure, and is an organic solvent. The content of the organic solvent (C) in the organic solvent contained in the present composition is preferably 70 to 100 mass%, more preferably 80 to 100 mass%, further preferably 90 to 100 mass%, and particularly preferably substantially 100 mass%. In addition, when a liquid monomer having a polymerizable unsaturated group is blended as the binder component (D) described later, or when a liquid defoaming agent, leveling agent, or reaction accelerator is blended as other component (E) described later, these liquid compounds are not included in the organic solvent.

[0122] In the general formula (5), R 10 R is preferably an oxyethylene group or an oxy(iso)propylene group, and more preferably an oxyethylene group. Furthermore, n is preferably an integer of 2 to 5, and more preferably an integer of 2 to 3. 11 The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 5, and further preferably 2 to 4. By selecting such an organic solvent (C), it is possible to achieve a balance between the solubility of the dispersant (B), the boiling point of the organic solvent, and industrial ease of availability.

[0123] The organic solvent (C) preferably has a boiling point of 150°C to 300°C, more preferably 190°C to 250°C, and particularly preferably 210°C to 250°C under normal pressure (1013 hPa).

[0124] Examples of the organic solvent (C) include diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate.

[0125] <Production of Dispersion Composition> The dispersion composition can be produced, for example, by blending an organic solvent (C), a dispersant (B), and, if necessary, an antifoaming agent and / or a stabilizer to form a homogeneous solution or dispersion, adding inorganic particles (A), thoroughly stirring and mixing, and then dispersing the mixture.

[0126] Examples of the device used for stirring and mixing include kneading and mixing devices such as a disper, a planetary mixer, a trimix, a homogenizer mixer, and a kneader, a tumbler mixer, an attritor, a roll mill, etc. In stirring and mixing, it is preferable to make the mixed liquid homogeneous and fluid.

[0127] Examples of the dispersing machine used in the dispersion treatment include kneading and mixing machines such as beads mills, colloid mills, planetary mixers, trimixes, homogenizer mixers, and kneaders, attritors, roll mills, and planetary mixers, etc. The dispersing machine used can be appropriately selected depending on the handling properties of the dispersion composition and the degree of aggregation of the inorganic particles (A).

[0128] The temperature during dispersion determines the dispersibility of inorganic particles (A), the solubility of dispersant (B), and the suppression of equipment wear. From this viewpoint, the temperature is preferably from 10 to 75°C, more preferably from 20 to 70°C, and particularly preferably from 30 to 70°C.

[0129] The dispersion time is appropriately adjusted while sampling the particle size of the inorganic particles. The dispersion time varies depending on the type of device, but is preferably about 0.1 to 10 hours, more preferably 0.5 to 5 hours, and particularly preferably 1 to 5 hours.

[0130] <Paint composition> The coating dispersion composition of the present invention further contains a binder component (D) in addition to the dispersion composition of the present invention.

[0131] <Binder component (D)> As the binder component (D), a binder resin and / or its precursor can be used. The binder resin can be dissolved in the organic solvent (C) or can be mixed as emulsion particles, and a solid (cured product) such as a coating film can be obtained by volatilizing the organic solvent. In addition, when the binder resin has a reactive functional group such as a polymerizable unsaturated group or an epoxy group, the curing reaction can be further promoted to improve the curability. The binder resin precursor is a component that undergoes a curing reaction by heat and / or light to generate a binder resin, and examples of the precursor include monomers and oligomers having multiple reactive functional groups such as polymerizable unsaturated groups and epoxy groups. Examples of the polymerizable unsaturated groups include vinyl groups, (meth)acryloyl groups, and (meth)allyl groups. The oligomer is a compound having a molecular weight of 1000 to 3000.

[0132] Examples of the binder resin include acrylic resin, polyester resin, polyurethane resin, epoxy resin, phenoxy resin, polyamide resin, polyether resin, silicone resin, polyolefin resin, polystyrene resin, polyvinyl alcohol resin, polyvinyl ester resin, polyacrylic acid resin, polyvinylpyrrolidone resin, vinyl chloride resin, carbonate resin, unsaturated carboxylic acid resin, fluorine resin, cellulose, rosin, natural rubber, etc., and copolymers thereof. Among these, acrylic resin, polyester resin, polyurethane resin, epoxy resin, and phenoxy resin are preferred, acrylic resin or epoxy resin is more preferred, and epoxy resin is particularly preferred.

[0133] Examples of the thermosetting binder resin precursor include glycidyl ethers such as glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, ethylene glycol diglycidyl ether, and polyethylene glycol diglycidyl ether; Phenols such as bisphenol A, bisphenol F, hydroquinone, and resorcinol; etc.

[0134] Examples of photocurable binder resin precursors include photopolymerizable compounds having a vinyl group, a (meth)acryloyl group, or a (meth)allyl group as a polymerizable unsaturated group. The photopolymerizable compounds can be used in combination with a photopolymerization initiator to effectively carry out a curing reaction.

[0135] When the binder component (D) is subjected to a curing reaction, the binder resin and / or its precursor is preferably a thermosetting resin. By selecting a thermosetting resin, a coating composition having good curability can be obtained even when the inorganic particles (A) are blended at a high concentration.

[0136] The amount of dispersant (B) relative to 100 parts by mass of the total amount of dispersant (B) and binder component (D) is preferably 1 to 40 parts by mass, more preferably 5 to 30 parts by mass, and particularly preferably 5 to 25 parts by mass. By setting the blending amount of dispersant (B) within this range, it is possible to achieve a high degree of compatibility between the dispersant function of dispersant (B) and the binder function of binder component (D).

[0137] <Method of producing coating composition> The coating composition of the present invention can be produced, for example, by blending the binder component (D) with the dispersion composition of the present invention and thoroughly stirring and mixing to dissolve the binder component (D) homogeneously. Alternatively, the coating composition can be produced by mixing the binder component (D) previously dissolved or dispersed in the organic solvent (C) or other organic solvent with the dispersion composition. It is also possible to produce a coating composition by blending the binder component (D) at any timing when producing the dispersion composition.

[0138] The apparatus used for producing the coating composition may be the same as the apparatus used for stirring and mixing the dispersion composition or the dispersing machine used for the dispersion treatment.

[0139] The coating composition can be used for various purposes, such as to produce thermally conductive cured products, electrically conductive cured products, magnetic cured products, and cured products of sealants for electronic components, depending on the type of inorganic particles (A) to be blended.

[0140] <Other ingredients (E)> The dispersion composition and coating composition of the present invention are compositions that further contain various additives such as dispersants, organic solvents, leveling agents, defoamers, reaction accelerators, rheology modifiers, colorants, stabilizers such as antioxidants, flame retardants, plasticizers, and ion scavengers as necessary. There are no particular limitations on each of these appropriately added materials, and they can be used alone or in combination of two or more types. The present composition can be particularly suitably used for forming thermally conductive cured products, electrically conductive cured products, magnetic cured products, and cured products of sealing materials for electronic components.

[0141] Examples of dispersants other than the dispersant (B) include surfactants, polymeric dispersants, etc. Examples of surfactants include anionic, cationic, amphoteric, or nonionic surfactants.

[0142] Examples of organic solvents other than the organic solvent (C) include organic solvents such as alcohol-based organic solvents, ketone-based organic solvents, glycol-based organic solvents, amide-based organic solvents, and ether-based organic solvents. These organic solvents are compounds different from the organic solvent (C) and preferably have a boiling point of 150° C. or less.

[0143] By using a leveling agent or an antifoaming agent, the appearance and density of the cured product can be improved. Examples of the leveling agent include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl-containing polydimethylsiloxane, polyetherester-modified hydroxyl-containing polydimethylsiloxane, acrylic copolymer, methacrylic copolymer, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, and lecithin. Examples of the antifoaming agent include silicone resin, silicone solution, copolymer of alkyl vinyl ether, acrylic acid alkyl ester, and methacrylic acid alkyl ester, vinyl ether polymer, and olefin polymer.

[0144] The reaction accelerator is not particularly limited, and may be a curing agent that accelerates the curing reaction of the binder component (D). Compounds commonly used as binder components can be used. Examples include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, imidazole compounds, latent hardeners, dibutyltin compounds, etc. When the reaction accelerator reacts with the binder component (D) and is incorporated into the chemical structure of the binder resin, the reaction accelerator is treated as a binder resin precursor and the amount of the binder component (D) is calculated.

[0145] The rheology modifier imparts thixotropy to the dispersion composition or coating composition, suppressing the sedimentation of the inorganic particles (A). It also contributes to the coatability of the composition. As the rheology modifier, various materials sold as thickeners or rheology control agents can be used.

[0146] <Cured product and its manufacturing method> The cured product of the present invention can be obtained, for example, by applying the coating composition of the present invention to a substrate and drying and / or curing it.

[0147] The method for applying the coating composition is not particularly limited, and the coating composition can be applied by various known methods such as die coating, dip coating, roll coating, doctor coating, gravure coating, and screen printing.

[0148] The method for drying the coating composition is not particularly limited, but it can be dried by various known methods such as a blower dryer, a hot air dryer, an infrared heater, or a far-infrared heater.

[0149] When the coating composition is further subjected to a curing reaction, the curing method is not particularly limited, but includes a method of aging at room temperature or under heating. The aging period for the curing reaction is, for example, about 1 to 5 days at 40°C, and about 10 hours at 180°C. If necessary, the curing reaction can be carried out in multiple temperature steps.

[0150] The type of substrate to which the coating composition is applied is not particularly limited, but various known substrates such as resin films, resin sheets, metal plates, and fillings for metal molds and casting dies can be used. EXAMPLES

[0151] The present invention will be described below based on examples, but the present invention is not limited thereto. In the examples, "parts" means "parts by mass" and "%" means "% by mass" unless otherwise specified.

[0152] <Inorganic particles (A)> Mitsubishi Carbon Black #33 (Mitsubishi Chemical Corporation): Carbon black, inorganic particles (A2). Average primary particle diameter 30 nm, BET specific surface area 85 m 2 / g. Hereafter referred to as #33. Bayferrox 4130 (LANXESS): Iron oxide, inorganic particles (A1). Average primary particle size 200 nm, BET specific surface area 8 m 2 / g. Fe content: 70% by mass. Below, #413 It's called 0. ·Ultra-fine Iron Powder YX5 / 5S (manufactured by Jiangsu Tianyi Ultrafine Metal Powder Co., Ltd.): Pure iron powder, inorganic particles (A1). Average primary particle diameter 1.2μm, BET specific surface area 1.0m 2 / g. Fe content: 96% by mass. Hereinafter referred to as iron powder A. Ultra-fine Iron Powder YMIM76g (manufactured by Jiangsu Tianyi Ultrafine Metal Powder Co., Ltd.): Pure iron powder with a silica layer on the surface, inorganic particles (A1). Average primary particle diameter 3.9 μm, BET specific surface area 0.2 m 2 / g. Fe content: 98% by mass. Hereinafter referred to as iron powder B. ·FeSiAl alloy, inorganic particles (A1). Average primary particle diameter 50μm, BET specific surface area 0.1m 2 / g, thickness 1 μm, scale-like. Fe content 85 mass%. Hereinafter referred to as Sendust.

[0153] <Dispersant> Solsperse 32000 (manufactured by Lubrizol), a polymer with polyethyleneimine as the main skeleton. Amine value 31 mg KOH / g, acid value 15 mg KOH / g, water content 0.6%. Hereinafter referred to as dispersant 9. Ajisper PB821 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), a polymer with a polyester structure. A copolymer of main chain polyallylamine and side chain polycaprolactone. Weight average molecular weight 50,000, acid value 17 mgKOH / g, amine value 10 mgKOH / g, water content 0.97%. Hereinafter referred to as Dispersant 10.

[0154] <Organic solvent (C)> Diethylene glycol monoethyl ether acetate (hereinafter referred to as CA). Diethylene glycol monobutyl ether acetate (hereinafter referred to as BCA). Ethylene glycol monobutyl ether acetate (hereinafter referred to as BCeA).

[0155] <Organic solvents other than organic solvent (C)> Ethylene glycol monobutyl ether (hereinafter referred to as BCE)

[0156] <Binder component (D)> Methyl methacrylate polymer (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). Hereinafter referred to as PMMA. jER-806 (Mitsubishi Chemical Corporation), bisphenol F type epoxy resin. Hereinafter referred to as jER-806.

[0157] <Reaction accelerator> Epomin SP-003 (polyethyleneimine). Hereinafter referred to as SP-003. 2-Ethyl-4-methylimidazole, hereafter referred to as 2E4MZ.

[0158] <Evaluation of Dispersant (B)> The dispersants used in the examples were evaluated by measuring the water content, molecular weight distribution, and acid value.

[0159] The water content of the dispersant (B) was measured using a Karl Fischer moisture meter ("CA-200" manufactured by Mitsubishi Chemical Analytech Co., Ltd., coulometric measurement). 1 to 2 g of the sample was heated at 140°C, and the amount of vaporized water was measured.

[0160] The number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution of the dispersant (B) were measured by gel permeation chromatography (GPC) equipped with a refractive index (RI) detector. The instrument used was an HLC-8220GPC (manufactured by Tosoh Corporation), with two separation columns connected in series, and both packings were "TSK-GELSUPERHZM-N" connected in series. The oven temperature was 40°C, tetrahydrofuran was used as the eluent, and the flow rate was 0.35 ml / min. The sample was dissolved in tetrahydrofuran to a concentration of 1 mass%, and 20 microliters were injected. Both Mn and Mw are values ​​converted to standard polystyrene.

[0161] The acid value of the dispersant (B) was measured by the following method: Approximately 1 g of the object to be measured for acid value was weighed out, 30 g of pyridine and 1 g of water were added, and the mixture was stirred for 10 minutes. Then, using a 0.1 N potassium hydroxide ethanol solution as a titrant, the mixture was titrated using a potentiometer (manufactured by Kyoto Electronics Manufacturing Co., Ltd., device name "potentiometric automatic titrator AT-710M") to measure the acid value of the resin and calculate the acid value per non-volatile content.

[0162] <Synthesis of dispersant (B)> [Synthesis Example 1] In a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer, 10.1 parts of benzyl alcohol, 79.7 parts of ε-caprolactone, and 0.05 parts of monobutyltin (IV) oxide as a catalyst were charged, and after replacing with nitrogen gas, the mixture was heated and stirred at 120°C for 4 hours. The non-volatile content was measured to confirm that 98% had reacted, and the first step ("Production Step 1" in each table below) was completed.

[0163] To the above reaction product, 10.2 parts of pyromellitic dianhydride and 0.05 parts of DBU (1,8-diazabicyclo-[5.4.0]-7-undecene) were added, and the mixture was replaced with nitrogen gas. The mixture was then heated and stirred at 130°C for 1 hour, and reacted at 100°C for another 5 hours. The acid value was measured to confirm that 97% or more of the acid anhydride had been half-esterified, and the second step ("Production Step 2" in the following tables) was completed. The resulting dispersant (dispersant 1) had an Mw of 3650 and an acid value of 56 mgKOH / g.

[0164] [Synthesis Examples 2-8] Dispersants 2 to 8 were obtained by synthesis in the same manner as in Example 1, except that the raw materials and the amounts charged were used as shown in Table 1. Of the above synthesis examples, Dispersants 1, 2, and 5 to 7 are examples of the present invention, Dispersants 3 and 4 are reference examples, and Dispersant 8 is a comparative example.

[0165] [Table 1]

[0166] Abbreviations in Table 1: PMA: Pyromellitic dianhydride BPDA 3,3',4,4'-biphenyltetracarboxylic dianhydride BTDA: 3,3,4,4-benzophenonetetracarboxylic dianhydride BTA 1,2,3,4-Butanetetracarboxylic dianhydride

[0167] <Evaluation of Dispersion Composition> Dispersion compositions according to the examples were produced by the production method described below. The viscosity (handling properties) of the dispersion compositions was evaluated according to the following criteria.

[0168] The viscosity of the dispersion compositions produced in Preparation of Dispersion Composition (1) to (2) described below was measured using a B-type viscometer ("BL" manufactured by Toki Sangyo Co., Ltd.; when the viscosity of the sample measured at a rotation speed of 60 rpm was less than 100 mPa·s, rotor No. 1 was used; when the viscosity was 100 mPa·s or more and less than 500 mPa·s, rotor No. 2 was used; when the viscosity was 500 mPa·s or more and less than 2000 mPa·s, rotor No. 3 was used; and when the viscosity was 2000 mPa·s or more and 10000 mPa·s or less, rotor No. 4 was used) at a sample temperature of 25°C, a rotor rotation speed of 6 rpm, and a measurement time of 1 minute, and then at a rotor rotation speed of 60 rpm and a measurement time of 1 minute. The evaluation criteria were as follows: The viscosity was measured at a rotation speed of 60 rpm. ◎: Viscosity is 0 mPa·s or more and 200 mPa·s or less (particularly good). ○: Viscosity is over 200 mPa·s and 500 mPa·s or less (good). △: Viscosity is over 500 mPa·s and 1000 mPa·s or less (acceptable). ×: Viscosity is between 1000 mPa·s and 2000 mPa·s (bad).

[0169] The viscosity of the dispersion composition produced in Preparation of Dispersion Composition (3) described below was measured immediately after stirring and mixing the sample for 30 seconds with a Thinky Mixer (2000 rpm) using a Brookfield viscometer ("BL", rotor No. 3, manufactured by Toki Sangyo Co., Ltd.) at a sample temperature of 25°C, a rotor rotation speed of 6 rpm, and a measurement time of 1 minute. The evaluation criteria were as follows. ◎: Viscosity is 0 mPa·s or more and 200 mPa·s or less (particularly good). 〇: Exceeding 200mPa·s and below 1000mPa·s (good). Good-: Over 1000 mPa·s to 2000 mPa·s (slightly better). △: Exceeding 2000mPa·s and below 20000mPa·s (acceptable). ×: Exceeds 20,000 mPa·s (no fluidity, poor).

[0170] <Preparation of Dispersion Composition (1)> [Example 1-1] A 225 ml glass bottle was charged with 85.3 parts of diethylene glycol monoethyl ether acetate and 0.7 parts of dispersant 1, and thoroughly stirred and mixed to dissolve dispersant 1. Next, 14 parts of Mitsubishi carbon black #33 was added, and the mixture was dispersed for 4 hours using a paint shaker with 150 parts of 1 mmΦ zirconia beads as a medium to obtain a dispersion composition.

[0171] [Examples 1-2 to 1-8, Comparative Examples 1-1 to 1-3] The same procedure as in Example 1-1 was carried out except that the materials and the amounts used in Example 1-1 were changed as shown in Table 2, to prepare dispersion compositions of Examples 1-2 to 1-8 and Comparative Examples 1-1 to 1-3, respectively.

[0172] The dispersion compositions obtained in Examples 1-1 to 1-8 all had a viscosity that was good for handling. In addition, these results show that a good dispersion composition can be obtained when the dispersant (B) is used as the dispersant and the organic solvent (C) is used as the main component of the organic solvent. On the other hand, the dispersion compositions obtained in Comparative Examples 1-1 to 1-3 all had poor fluidity and were poor.

[0173] [Table 2]

[0174] <Preparation of Dispersion Composition (2)> [Example 2-1] A 225 ml glass bottle was charged with 83.5 parts of diethylene glycol monobutyl ether acetate and 1.5 parts of dispersant 1, and thoroughly stirred and mixed to dissolve dispersant 1. Next, 15 parts of Mitsubishi carbon black #33 was added, and the mixture was dispersed for 4 hours using a paint shaker with 150 parts of 1 mmΦ zirconia beads as a medium to obtain a dispersion composition.

[0175] [Examples 2-2 to 2-4, Comparative Example 2-1] The same procedure as in Example 2-1 was carried out except that the materials and the amounts used thereof were changed as shown in Table 3, to prepare dispersion compositions of Examples 2-2 to 2-4 and Comparative Example 2-1.

[0176] The dispersion compositions obtained in Examples 2-1 to 2-4 all had a viscosity with good handleability. On the other hand, the dispersion composition obtained in Comparative Example 2-1 had poor fluidity. From the above results, it can be seen that a good dispersion composition can be obtained by using a dispersant (B) having a structure derived from a monoalcohol with a molecular weight of 300 or less, containing an aromatic ring or an alkyleneoxy unit as the terminal portion A.

[0177] [Table 3]

[0178] <Preparation of Dispersion Composition (3)> [Example 3-1] Ethylene glycol monobutyl ether acetate 36 in a 225 ml glass bottle. 37 parts of ethanol and 0.63 parts of dispersant 1 were charged and thoroughly mixed and stirred to dissolve dispersant 1. Next, 63 parts of Bayferrox 4130 were added, and dispersed for 2 hours using a paint shaker with 150 parts of 1 mmΦ zirconia beads as a medium to obtain a dispersion composition.

[0179] [Examples 3-2 to 3-4, Comparative Example 3-1] The same procedure as in Example 3-1 was carried out except that the materials and the amounts used thereof were changed as shown in Table 4, to prepare dispersion compositions of Examples 3-2 to 3-4 and Comparative Example 3-1.

[0180] The dispersion compositions obtained in Examples 3-1 to 3-4 all had a viscosity that was favorable for handling. On the other hand, the dispersion composition obtained in Comparative Example 3-1 had no fluidity and was poor. From the above results, it can be seen that the tetravalent group X 1 As the dispersant, a dispersant having a structure represented by general formula (2) to general formula (4) ( It can be seen that by using B), a good dispersion composition can be obtained.

[0181] [Table 4]

[0182] <Evaluation of coating composition> Coating compositions according to the examples were produced by the production method described below. The viscosity (handling properties) of the coating compositions was evaluated according to the following criteria.

[0183] The viscosity of the coating composition produced in Preparation of Coating Composition (1) described below was measured by stirring and mixing the sample for 30 seconds with a Thinky Mixer (2000 rpm) and then immediately measuring the viscosity with a Brookfield viscometer ("HB" manufactured by Eiko Seiki Co., Ltd., spindle SC4-14 when the viscosity of the sample was 200 Pa s or less, and spindle SC4-25 when the viscosity exceeded 200 Pa s) at a sample temperature of 25°C, a spindle rotation speed of 50 rpm, and a measurement time of 1 minute. The evaluation criteria were as follows: ◎: Viscosity is between 0 Pa·s and 100 Pa·s (particularly good). 〇: Exceeding 100Pa·s and below 200Pa·s (good).

[0184] <Preparation of coating composition (1)> [Example 4-1] A 225 ml glass bottle was charged with 8.5 parts of diethylene glycol monoethyl ether acetate, 0.60 parts of dispersant 5, and 0.90 parts of methyl methacrylate polymer as binder component (D), and the mixture was thoroughly stirred and mixed while heating to 60° C. to dissolve dispersant 5. After that, the solution was cooled to 25° C., and 90 parts of iron powder A was added, followed by stirring and kneading at room temperature for 4 minutes with a Thinky Mixer (2000 rpm) to obtain a coating composition.

[0185] [Examples 4-2 to 4-6] Except for changing the materials and amounts used in Example 3-1 as shown in Table 5, the same procedure as in Example 3-1 was carried out to produce Examples 3-2 to 3-6, respectively.

[0186] The coating compositions obtained in Examples 4-1 to 4-6 all had a viscosity that provided good handling properties. From the above results, it can be seen that good coating compositions can be obtained by using the dispersant (B).

[0187] [Table 5]

[0188] <Preparation of coating composition (2) and cured product> [Example 5-1] In a 225 ml glass bottle, 61.67 parts of diethylene glycol monobutyl ether acetate and 5 parts of methyl methacrylate polymer as binder component (D) were charged, and the binder component (D) was dissolved by thoroughly stirring and mixing while heating to 60° C. After that, this solution was cooled to 25° C., and then 33.33 parts of the dispersion composition prepared in Example 2-4 was charged and stirred with a Disper (stirring blade Φ2 cm, 500 rpm) for 1 minute to obtain a coating composition. The obtained coating composition was applied using a bar coater onto a corona-discharge-treated polyethylene terephthalate (PET) film so that the thickness after drying would be 5 μm, and then it was dried in an oven at 120° C. for 5 minutes to produce a cured product, the appearance of which was visually evaluated according to the following criteria. The resulting cured product was visually evaluated according to the following criteria. 〇: No defects such as missing parts or bumps (good) ×: There are a lot of lumps (defective)

[0189] [Example 5-2] Example 5-2 was produced in the same manner as Example 5-1, except that the materials and the amounts used thereof were changed as shown in Table 6.

[0190] [Example 5-3] In a 225 ml glass bottle, 86.96 parts of the dispersion composition prepared in Example 2-4 was charged, 11.74 parts of jER-806 as the binder component (D), and 1.3 parts of SP-003 as a curing agent were charged, and the mixture was stirred for 1 minute with a disper (agitating blade Φ2 cm, 500 rpm) to obtain a coating composition. The resulting coating composition was applied to a corona discharge-treated PET film using a bar coater so that the thickness after drying would be 5 μm, and then dried in an oven at 120° C. for 5 minutes. The coating was then further heated in an oven at 70° C. for 3 hours to complete the curing reaction, producing a cured product, whose appearance was visually evaluated according to the following criteria. The resulting cured product was visually evaluated according to the following criteria. 〇: No defects such as missing parts or bumps (good) ×: There are a lot of lumps (defective)

[0191] [Examples 5-4 to 5-6] Except for changing the materials and the amounts used in Example 5-3 as shown in Table 6, the same procedure as in Example 5-3 was carried out to prepare Examples 5-4 to 5-6.

[0192] The coating compositions obtained in Examples 5-1 to 5-6 all had a viscosity that provided good handling properties, and the cured products produced from these coating compositions all had a good gloss when visually inspected.

[0193] [Table 6] < / n> < / h> < / n> < / h> < / n> < / h> < / n> < / h> < / n> < / h>

Claims

1. A dispersion composition comprising inorganic particles (A), a dispersant, and an organic solvent, The inorganic particle (A) is a magnetic inorganic particle, The dispersion composition contains 60 to 98% by mass of the magnetic inorganic particles, The aforementioned dispersant includes a dispersant (B) having a structure represented by the following general formula (1), A dispersion composition comprising an organic solvent (C) having a structure represented by the following general formula (5). 【Chemistry 1】 [In general formula (1), A １ ~A ４ This is a combination selected from the groups (A), (B), and (C) below, (A): A １ ~A ４ Two of the sites are identical or different monovalent polymer sites (P), and the other two sites are identical or different -C(=O)OH or -CH ２ It is C(=O)OH. (B): A １ ~A ４ One of the sites is a monovalent polymer site (P), and the other three sites are either identical or different -C(=O)OH or -CH ２ It is C(=O)OH. (C): A １ ~A ４ One of the sites is a monovalent polymer site (P), and the other two sites are the same or different from each other -C(=O)OH or -CH ２ C(=O)OH, and another one of the sites is -C(=O)-Xa-Ra (where Xa is -O-, or N(Ra ２ )-. Ra is a group selected from the group consisting of alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, cycloalkyl groups having 3 to 18 carbon atoms, and aryl groups having 6 to 18 carbon atoms. Ra ２ (This is a group selected from the group consisting of a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms.) The monovalent polymer moiety (P) is a cyclic ester polymer moiety having terminal moiety A, Terminal A is a structure derived from a monoalcohol with a molecular weight of 300 or less, containing an aromatic ring or alkylene oxy unit. X １ This is a tetravalent group represented by the following general formulas (2), (3), or (4). 【Chemistry 2】 [In general formula (2), k represents an integer of 1 or 2. * represents a combination.] [In general formula (3), R 2 This is a direct bond, -CH 2 -, -O-, -C(=O)-, -C(=O)OCH 2 CH 2 OC(=O)-, -C(=O)OCH(OC(=O)CH 3 )CH 2 OC(=O)-,-SO 2 -, -C(CF 3 ) 2 -,formula: 【Transformation 3】 This is the base represented by . * represents a bond. [The total number of carbon atoms in the group represented by general formula (4) is 4 to 20, In general formula (4), R ３ These are directly bonded, -O-, or divalent hydrocarbon groups having 1 to 8 carbon atoms. R ４ , R ５ , R ６ , R ７ , R ８ and R ９ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, R ３ , R ４ , R ５ , R ６ , R ７ , R ８ and R ９ These may be joined together to form a ring. General formula (5) CH ３ COO(R １０ ) ｎ R １１ [In general formula (5), n represents an integer from 1 to 10. Also, R １０ R indicates an oxyalkylene group, １１ This indicates an alkyl group.

2. The dispersion composition according to claim 1, wherein the organic solvent (C) is contained in 70 to 100% by mass of 100% by mass of the organic solvent.

3. In the above general formula (5), R 10 The dispersion composition according to claim 1, wherein is an oxyethylene group or an oxy(iso)propylene group.

4. In the above general formula (5), R 11 The dispersion composition according to claim 1, wherein is an unsubstituted alkyl group having 2 to 4 carbon atoms.

5. The dispersion composition according to claim 1, wherein the terminal portion A has a structure derived from a monoalcohol with a molecular weight of 300 or less containing an aromatic ring unit.

6. X 1 The dispersion composition according to claim 1, wherein the group is a tetravalent group represented by general formula (3) or general formula (4).

7. The dispersion composition according to claim 1, wherein the cyclic ester polymer moiety has structural units derived from caprolactone or valerolactone.

8. The dispersion composition according to claim 1, wherein the dispersant (B) has an acid value of 25 to 200 mg KOH / g.

9. The dispersion composition according to claim 1, wherein the dispersant (B) has a weight-average molecular weight of 1,000 to 50,000.

10. The dispersion composition according to claim 1, wherein the inorganic particles (A) are inorganic particles containing 1% by mass or more of Fe.

11. The dispersion composition according to claim 1, wherein the inorganic particles (A) have an average primary particle diameter of 0.5 to 100 μm.

12. A paint composition comprising the dispersion composition according to any one of claims 1 to 11 and a binder component (D).

13. A cured product of the paint composition according to claim 12.

14. A dispersant for magnetic inorganic particles having a structure represented by the following general formula (7), for use in the dispersion composition according to any one of claims 1 to 11. 【Chemistry 4】 [In general formula (7), A ５ ~A ８ This is a combination selected from the groups (A2), (B2), and (C2) below, (A2): A ５ ~A ８ Two of these sites are identical or different monovalent polymer sites (P2), and the other two sites are identical or different -C(=O)OH or CH ２ It is C(=O)OH. (B2): A ５ ~A ８ One of the sites is a monovalent polymer site (P2), and the other three sites are either identical or different -C(=O)OH or CH ２ It is C(=O)OH. (C2): A ５ ~A ８ One of the sites is a monovalent polymer site (P2), and the other two sites are either identical or different -C(=O)OH or CH ２ It is C(=O)OH, Another part is -C(=O)-Xb-Rb (where Xb is -O- or N(Rb) ２ ) - is. Rb is a group selected from the group consisting of alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, cycloalkyl groups having 3 to 18 carbon atoms, and aryl groups having 6 to 18 carbon atoms. ２ (This is a group selected from the group consisting of a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms.) The monovalent polymer moiety (P2) is a cyclic ester polymer moiety having terminal moiety A2, wherein terminal moiety A2 is a structure derived from a monoalcohol with a molecular weight of 300 or less and containing an aromatic ring unit, and the cyclic ester polymer moiety is a polymer having a structure derived from caprolactone or valerolactone. X ３ This is a tetravalent group represented by the following general formulas (8), (9), or (10). 【Transformation 5】 [In general formula (8), k' represents an integer of 1 or 2. * represents a combination.] [In general formula (9), R 12 This is a direct bond, -CH 2 -, -O-, -C(=O)-, -C(=O)OCH 2 CH 2 OC(=O)-, -C(=O)OCH(OC(=O)CH 3 )CH 2 OC(=O)-,-SO 2 -, -C(CF 3 ) 2 -,formula: 【Transformation 6】 This is the base represented by . * represents a bond. [The total number of carbon atoms in the group represented by general formula (10) is 4 to 20, In general formula (10), R １３ These are directly bonded, -O-, or divalent hydrocarbon groups having 1 to 8 carbon atoms. R １４ , R １５ , R １６ , R １７ , R １８ and R １９ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, R １３ , R １４ , Rl １５ , R １６ , R １７ , R １８ and R １９ These may be joined together to form a ring.

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