JP6593942B2 - Fine particle composite metal hydroxide, fired product thereof, production method thereof and resin composition thereof - Google Patents

Description

  The present invention relates to a composite metal hydroxide having a small average lateral width of primary particles, in which primary particles are dispersed and having high acid resistance, a fired product thereof, a production method thereof, and a resin composition thereof.

  In recent years, a technique of using magnesium hydroxide for a separator of a lithium ion battery has become widespread. In a non-aqueous electrolyte battery, particularly a non-aqueous electrolyte secondary battery, heat generation accompanying the decomposition of the positive electrode is considered to be the most dangerous, and this decomposition occurs in the vicinity of 300 ° C. For this reason, if magnesium hydroxide having an endothermic reaction generation temperature in the range of 300 ° C. to 400 ° C. is blended in the separator, it is effective in preventing heat generation of the battery. In Patent Document 1, as an inorganic filler, an aspect using a metal hydroxide is preferable from the viewpoints of flame retardant improvement effect, handling property, static elimination effect, battery durability improvement effect, and the like, among which aluminum hydroxide or water It is disclosed that magnesium oxide is preferable and that the average particle diameter of the inorganic filler is preferably in the range of 0.1 to 2 μm from the viewpoint of short circuit resistance at high temperature, moldability, and the like.

  Patent Document 1 further discloses a method for forming a heat-resistant porous layer on at least one surface of a polyolefin porous substrate as a method for producing a separator of a lithium ion battery. More specifically, an inorganic filler is dispersed in an organic solvent to prepare a coating slurry, which is applied to a polyolefin porous substrate. Since a uniform coating film cannot be obtained unless the inorganic filler is dispersed in the coating slurry, the inorganic filler is required to have high dispersibility. When the dispersibility of the inorganic filler is not preferred, a technique is disclosed in which the inorganic filler is surface-treated with a silane coupling agent or the like to improve the dispersibility.

  With the miniaturization of lithium ion batteries, it is necessary to reduce the thickness of the separator, and the inorganic filler to be blended is also required to be fine. In Patent Document 2, when magnesium hydroxide is used as an ultra-thin battery separator, the average particle size is 0.8 μm or less because the average particle size is reflected in the thickness of the separator. It is preferable that the average particle size is 0.7 μm or less, and a magnesium compound having an average particle size of 0.1 μm or less can be synthesized. It is disclosed that it is not preferable because it affects the coating process in forming the layer.

  Various attempts have been made to synthesize fine particle magnesium hydroxide having an average primary particle width of 1 μm or less. For example, in Patent Document 3, magnesium hydroxide having an average primary particle width of 20 to 50 nm and an average secondary particle width of 1 to 100 nm is synthesized using a microreactor.

  In Patent Document 4, magnesium hydroxide having an average secondary particle diameter of 25.4 nm is synthesized by reacting a magnesium salt and a hydroxide salt using a microreactor.

  It is acid resistance that becomes a problem when magnesium hydroxide is used in a separator of a lithium ion battery. In Patent Document 5, hydrogen fluoride (HF) present in a minute amount in a battery reacts with an inorganic filler, and the surface of the inorganic filler is fluorinated, and water is generated at that time, and this water is used as an electrolyte or an electrode. If the SEI (Solid Electrolyte Interface) film formed on the surface is decomposed, or if the electrolytic solution or SEI film is decomposed, the internal resistance of the battery will increase, and the lithium necessary for charge / discharge will be deactivated. It has been disclosed that there is a possibility that the durability of the resin may deteriorate.

  In Patent Document 6, as in the present invention, more specifically, by combining a hydroxide of at least one transition metal selected from Mn, Fe, Co, Ni, Cu and Zn with magnesium hydroxide, more specifically, Discloses that the acid resistance of the particles is improved by forming a solid solution of both. However, the secondary particle diameter of the disclosed composite metal hydroxide is 0.2 to 4 μm, and it was necessary to make the particle diameter less than 0.2 μm in order to use it for a thin film separator. However, magnesium hydroxide having fine particles, high dispersibility, high purity and excellent acid resistance has not been provided so far.

WO2012-081556 A1 JP, 2006-62689, A WO2013-122239 A1 JP2011-195384 JP 2010-278018 JP-A-6-41441

  An object of the present invention is to overcome weakness in acid resistance and aggregation of primary particles, which are problems of the prior art that occur when the average width of primary particles of magnesium hydroxide is reduced. Solving these problems, more specifically, (1) By improving acid resistance, the reaction with hydrogen fluoride, which occurs when magnesium hydroxide is used for separators of lithium ion batteries, is suppressed. It is possible to maintain the durability of the battery, and (2) to improve the dispersibility to form a heat-resistant porous layer having no irregularities when it is thinned.

The present invention provides a composite metal hydroxide represented by the following formula (1) satisfying the following (A) and (B), which has overcome the above problems.
(Mg) _1-X (M ²⁺ ) _X (OH) ₂ (1)
(Wherein, M ²⁺ is at least one divalent metal selected from Cr, Mn, Fe, Co, Ni, Cu and Zn, and the range of X is 0 <X <0.5.)
(A) The average lateral width of primary particles by SEM method is 10 nm or more and less than 200 nm;
(B) The monodispersity represented by the following formula is 50% or more;
Monodispersity (%) = (Average width of primary particles by SEM method / Average width of secondary particles by dynamic light scattering method) × 100

The method for producing a composite metal hydroxide of the present invention includes the following steps (1) to (4).
(1) Raw material preparation for obtaining a water-soluble composite metal salt aqueous solution by mixing a water-soluble magnesium salt aqueous solution and at least one water-soluble metal salt aqueous solution selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn Process.
(2) A reaction step in which a water-soluble composite metal salt aqueous solution obtained in (1) is reacted with an alkali metal hydroxide aqueous solution to obtain a slurry containing a product.
(3) A maturing step of stirring and holding the slurry containing the product obtained in (2) at 0 to 100 ° C. for 1 to 24 hours.
(4) A wet pulverization step of wet pulverizing the slurry containing the product after aging obtained in (3).

  From the group consisting of anionic surfactant, cationic surfactant, phosphate ester treatment agent, silane coupling agent, titanate coupling agent, aluminum coupling agent, silicone treatment agent, sodium silicate after wet grinding By performing the surface treatment with one or more selected ones, the acid resistance can be further increased, and aggregation of the primary particles during drying can be prevented.

The composite metal hydroxide of the present invention can overcome weakness in acid resistance and aggregation of primary particles, which are problems of the prior art that occur when the average width of primary particles of magnesium hydroxide is reduced. .
For this reason, by mix | blending with the separator of a lithium ion battery, reaction with hydrogen fluoride can be suppressed and the safety | security of a battery can be improved, suppressing the film thickness of a separator. Further, the composite metal hydroxide of the present invention can be suitably used as a flame retardant. Since the fine particles are highly dispersed, the amount of the resin can be reduced, and the acid resistance of the resin can be improved.

  The composite metal hydroxide of the present invention can be suitably used for various applications such as an antibacterial agent, an oral bactericide, a heat conductive filler, a fine ceramic raw material, and an adsorbent. Further, by firing the composite metal hydroxide of the present invention, a composite metal oxide having fine particles, high dispersion and high acid resistance can be produced. The oxides are fine particles and highly dispersed, so they are used for pharmaceutical gastrointestinal drugs, acid acceptors for synthetic rubbers and adhesives, thickeners for FRP production, additives for producing electrical steel sheets, heat conductive fillers, magnesia grinding stone materials It can be suitably used for various applications such as fine ceramic raw materials, brake materials and adsorbents.

It is a schematic diagram of how to measure the lateral width of primary particles when using the SEM method. It is a schematic diagram of how to measure the lateral width of the secondary particles when the dynamic light scattering method is used. 2 is an SEM photograph of 100000 times the composite metal hydroxide of Sample 1 of Example 1. FIG. 4 is a SEM photograph at 100000 times the composite metal oxide of Sample 23 in Example 33. FIG.

  Hereinafter, the present invention will be specifically described.

<Composite metal hydroxide>
The metal type, the range of X, the average width of primary particles, and the monodispersity of the composite metal hydroxide of the present invention are as follows.

(Metal type)
In the composite metal hydroxide represented by the formula (1), M ²⁺ is at least one divalent metal selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn. Preferred M ²⁺ is Ni and / or Zn because of excellent acid resistance and easy availability. As a flame retardant use, the formation of a carbonized layer on the plastic surface can be promoted and the flame retardancy can be improved by the dehydrogenation catalytic effect of the M ²⁺ metal element.

(Range of X)
In the composite metal hydroxide represented by the formula (1), the range of X is 0 <X <0.5, the preferable range is 0.005 ≦ X ≦ 0.4, and the more preferable range is 0.01 ≦ X ≦ 0.2. When the value of X is 0.5 or more, molding defects due to foaming occur, which is not preferable. This is because the dehydration temperature of M ²⁺ metal hydroxide is lower than that of magnesium hydroxide.

(Average width of primary particles)
In the composite metal hydroxide represented by the formula (1), (A) the average lateral width of the primary particles by the SEM method is 10 nm or more and less than 200 nm, preferably 10 nm or more and less than 100 nm, more preferably 10 nm or more and 50 nm. Is less than. The average lateral width of the primary particles is determined from the arithmetic average of the measured values of the lateral width of any 100 crystals in the SEM photograph by SEM (scanning electron microscope). FIG. 1 is a schematic view of how to measure the width of primary particles when the SEM method is used. As shown by the arrows in FIG. 1, the lateral width of the primary particles is measured by measuring the diameter of the particles when the primary particles have a hexagonal plate shape. The lateral width of primary particles cannot be measured by the dynamic light scattering method in principle. Therefore, an accurate value can be calculated by visually confirming with the SEM method.

(Monodispersity)
In the composite metal hydroxide represented by the formula (1), the monodispersity represented by the following formula (B) is 50% or more, preferably 80% or more. The monodispersity is obtained by the following formula.
Monodispersity (%) = (Average width of primary particles by SEM method / Average width of secondary particles by dynamic light scattering method) × 100
By increasing the monodispersity, a heat-resistant porous layer having no irregularities can be formed when used for a separator of a lithium ion battery. The average lateral width of the secondary particles is measured by a dynamic light scattering method. Secondary particles are formed by aggregation of a plurality of primary particles. FIG. 2 is a schematic diagram of how to measure the width of secondary particles when the dynamic light scattering method is used. The longest diameter of the secondary particles is the width. That is, as shown by the arrows and dotted lines in FIG. 2, the diameter of the sphere when the secondary particles are considered to be wrapped by the sphere is measured. In the SEM method, it is difficult to accurately measure the lateral width of the secondary particles.

(surface treatment)
In the composite metal hydroxide represented by the formula (1), in order to improve acid resistance and dispersibility, it is desirable to perform a surface treatment on the particle surface. Examples of surface treatment agents include anionic surfactants, cationic surfactants, phosphate ester treatment agents, silane coupling agents, titanate coupling agents, aluminum coupling agents, silicone treatment agents, sodium silicate, etc. However, this is not a limitation. A preferable surface treatment agent from the viewpoint of improving acid resistance includes the combined use of sodium silicate and a cationic surfactant. Since the crystal surface of magnesium hydroxide has a positive charge, high acid resistance can be imparted by first treating the surface with sodium silicate and then treating the surface with a cationic surfactant. The total amount of the surface treatment agent is 0.01 to 20% by weight, preferably 0.5 to 10% by weight, based on the weight of the composite metal hydroxide represented by the formula (1).

<Composite metal oxide>
The composite metal oxide of the present invention is represented by the following formula (2), and the metal type, the range of X, the average lateral width of the primary particles, and the monodispersity are as follows.
(Mg) _1-X (M ²⁺ ) _X O (2)

(Metal type)
In the composite metal oxide represented by the formula (2), M ²⁺ is at least one divalent metal selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn. Preferred M ²⁺ is Ni and / or Zn because of excellent acid resistance and easy availability.

(Range of X)
In the composite metal oxide represented by the formula (1), the range of X is 0 <X <0.5, the preferable range is 0.005 ≦ X ≦ 0.4, and the more preferable range is 0.01 ≦ X. ≦ 0.2.

(Average width of primary particles)
In the composite metal oxide represented by the formula (2), (A) the average lateral width of primary particles by SEM method is 10 nm or more and less than 200 nm, preferably 10 nm or more and less than 100 nm, more preferably 10 nm or more and less than 50 nm. It is. The average lateral width of the primary particles is obtained from the arithmetic average of the measured lateral widths of any 100 crystals in the SEM photograph by the SEM method.

(Monodispersity)
In the composite metal oxide represented by the formula (2), the monodispersity represented by the following formula (B) is 50% or more, preferably 80% or more. The average lateral width of the secondary particles is measured by a dynamic light scattering method. This is because it is difficult for the SEM method to accurately measure the lateral width of the secondary particles.
Monodispersity (%) = (Average width of primary particles by SEM method / Average width of secondary particles by dynamic light scattering method) × 100

(surface treatment)
In the composite metal oxide represented by the formula (2), in order to improve acid resistance and dispersibility, it is desirable to perform surface treatment on the particle surface. Examples of surface treatment agents include anionic surfactants, cationic surfactants, phosphate ester treatment agents, silane coupling agents, titanate coupling agents, aluminum coupling agents, silicone treatment agents, sodium silicate, etc. However, this is not a limitation. The total amount of the surface treatment agent is 0.01 to 20% by weight, preferably 0.5 to 10% by weight, based on the weight of the composite metal oxide represented by the formula (2) .

<Resin composition>
The resin composition of the present invention contains 0.1 to 250 parts by weight of the composite metal hydroxide of the present invention with respect to 100 parts by weight of the resin. The compounding amount of the composite metal hydroxide is preferably 1 to 200 parts by weight.

  There is no particular restriction on the mixing and kneading method of the resin and the composite metal hydroxide of the present invention, and any method can be used as long as both can be mixed uniformly. For example, they are mixed and kneaded by a single or twin screw extruder, a roll, a Banbury mixer or the like. There is no special restriction | limiting also in a shaping | molding method, According to the kind of resin and rubber, the kind of desired molded article, etc., a well-known shaping | molding means can be employ | adopted arbitrarily. For example, injection molding, extrusion molding, blow molding, press molding, rotational molding calendar molding, sheet forming molding, transfer molding, laminate molding, vacuum molding, and the like.

  The resin used in the present invention means a resin and / or rubber, for example, polyethylene, a copolymer of ethylene and another α-olefin, a copolymer of ethylene and vinyl acetate, ethylene and an acrylic acid ether, Copolymer of ethylene and methyl acrylate, polypropylene, copolymer of propylene and other α-olefin, polybutene-1, poly-4-methylpentene-1, polystyrene, styrene and acrylonitrile Copolymer, Copolymer of ethylene and propylene diene rubber, Copolymer of ethylene and butadiene, Polyvinyl acetate, Polylactic acid, Polyvinyl alcohol, Polyacrylate, Polymethacrylate, Polyurethane, Polyester, Polyether, Polyamide, ABS , Polycarbonate, polyphenylene sulfide, etc. A plastic resin is mentioned. Moreover, thermosetting resins, such as a phenol resin, a melamine resin, an epoxy resin, an unsaturated polyester resin, an alkyd resin, are mentioned. Further, EPDM, SBR, NBR, butyl rubber, chloroprene rubber, isoprene rubber, chlorosulfonated polyethylene rubber, silicon rubber, fluorine rubber, chlorinated butyl rubber, brominated butyl rubber, epichlorohydrin rubber, chlorinated polyethylene and the like can be mentioned.

  In addition to the composite metal hydroxide, the resin composition of the present invention includes other additives such as antioxidants, reinforcing agents such as talc, ultraviolet absorbers, lubricants, matting agents such as fine silica, carbon black and the like. Flame retardants such as pigments, bromine-based flame retardants and phosphate ester-based flame retardants can be appropriately selected and blended. In addition, flame retardant aids such as zinc stannate, alkali metal stannate, carbon powder, and fillers such as calcium carbonate can be appropriately selected and blended. The preferred blending amount of these additives is 0.01 to 5 parts by weight of antioxidant, 0.1 to 50 parts by weight of reinforcing agent, and 0.01 to 5 parts by weight of UV absorber with respect to 100 parts by weight of the resin. 0.1-5 parts by weight lubricant, 0.01-5 parts by weight matting agent, 0.01-5 parts by weight pigment, 0.1-50 parts by weight flame retardant, 0.01-10 parts by weight Part of flame retardant aid, 1 to 50 parts by weight of filler.

<Method for producing composite metal hydroxide>
The method for producing a composite metal hydroxide of the present invention includes the following steps (1) to (4).
(1) Raw material preparation for obtaining a water-soluble composite metal salt aqueous solution by mixing a water-soluble magnesium salt aqueous solution and at least one water-soluble metal salt aqueous solution selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn Process.
(2) A reaction step in which a water-soluble composite metal salt aqueous solution obtained in (1) is reacted with an alkali metal hydroxide aqueous solution to obtain a slurry containing a product.
(3) A maturing step of stirring and holding the slurry containing the product obtained in (2) at 0 to 100 ° C. for 1 to 24 hours.
(4) A wet pulverization step of wet pulverizing the slurry containing the product after aging obtained in (3).

(Raw material adjustment process)
A water-soluble magnesium salt aqueous solution and at least one water-soluble metal salt aqueous solution selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn are mixed to prepare a water-soluble composite metal salt aqueous solution. Examples of the water-soluble magnesium salt include, but are not limited to, magnesium chloride, magnesium nitrate, magnesium acetate, magnesium sulfate and the like. In order to prevent aggregation of primary particles, it is preferable to use magnesium chloride, magnesium nitrate, or magnesium acetate. Examples of the aqueous solution of at least one water-soluble composite metal salt selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, and Zn include chloride salts, nitrates, acetates, sulfates, etc. is not. From the viewpoint of increasing acid resistance and preventing agglomeration of primary particles, hydrochloride, nitrate, and acetate are preferred. The density | concentration of composite metal salt aqueous solution is 0.1-5.0 mol / L as (Mg + M < ²⁺ >), Preferably it is 0.4-4.0 mol / L. The ratio of Mg to M ²⁺ is 0 <M ²⁺ / Mg <1, preferably 0.005 ≦ M ²⁺ /Mg≦0.667, more preferably 0.010 ≦ M ²⁺ /Mg≦0.250. is there.

(Reaction process)
A slurry containing a composite metal hydroxide can be produced by reacting an aqueous solution of a composite metal salt with an aqueous alkali metal hydroxide solution. Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide, but are not limited thereto. Examples of the reaction method include batch reaction and continuous reaction, but are not limited thereto. In consideration of productivity and reaction uniformity, a continuous reaction is preferably used. The pH during the reaction is adjusted to 9.0 to 12.0, preferably 9.5 to 11.5, and more preferably 10.0 to 11.0. When the reaction pH is lower than 9.0, the primary particles grow when the slurry is aged, which is not preferable. When the reaction pH is higher than 12.0, it is not preferable because impurities derived from the raw material are likely to precipitate and for economic reasons. The density | concentration of an alkali metal hydroxide is 0.1-20.0 mol / L, Preferably it is 0.4-15.0 mol / L. The density | concentration at the time of reaction is 0.1-5.0 mol / L in conversion of a composite metal hydroxide, Preferably it is 0.4-4.0 mol / L. When the concentration during the reaction is lower than 0.1 mol / L, the productivity is low, and when it is higher than 5.0 mol / L, the primary particles are aggregated, which is not preferable. Reaction temperature is 0-100 degreeC, Preferably it is 10-60 degreeC, More preferably, it is 20-40 degreeC. When the reaction temperature is higher than 100 ° C., the primary particles grow to 200 nm or more, which is not preferable. When the reaction temperature is less than 0 ° C., the slurry freezes, which is not preferable.

(Aging process)
The post-reaction slurry is stirred and held at 0-100 ° C. for 1-24 hours. By passing through this step, it is possible to relax the aggregation of primary particles that are strong immediately after the reaction. If the aging time is less than 1 hour, it is not sufficient as a time for loosening the aggregation of the primary particles. Aging for longer than 24 hours does not make sense because there is no change in the aggregated state. The preferred aging time is 2 to 18 hours, more preferably 4 to 15 hours. If the aging temperature is higher than 100 ° C., the primary particles grow to 200 nm or more, which is not preferable. An aging temperature of less than 0 ° C. is not preferable because the slurry freezes. A more preferable aging temperature is 10 to 60 ° C, and most preferably 20 to 40 ° C. The concentration at the time of aging is 0.1 to 5.0 mol / L, preferably 0.4 to 4.0 mol / L, in terms of composite metal hydroxide. When the aging concentration is lower than 0.1 mol / L, the productivity is low, and when it is higher than 5.0 mol / L, the primary particles are aggregated, which is not preferable.

(Wet grinding process)
The slurry after the aging treatment is dehydrated, washed with deionized water having a weight 20 times the solid content, and then re-emulsified with deionized water. The slurry after re-emulsification is wet pulverized. For wet pulverization, for example, a bead mill or a high-pressure homogenizer is preferably used. The temperature during wet pulverization is 0 to 100 ° C, more preferably 10 to 60 ° C, and most preferably 20 to 40 ° C. If the temperature during wet pulverization is 100 ° C. or higher, the primary particles grow to 200 nm or more, which is not preferable. If the temperature during wet pulverization is less than 0 ° C., the slurry will freeze, which is not preferable. The density | concentration at the time of wet grinding is 0.1-5.0 mol / L in conversion of a composite metal hydroxide, Preferably it is 0.4-4.0 mol / L. When the concentration at the time of wet pulverization is lower than 0.1 mol / L, productivity is low, and when it is higher than 5.0 mol / L, aggregation of primary particles cannot be solved, which is not preferable. In the case of a bead mill, a preferable bead diameter is 0.001 mm to 0.1 mm, more preferably 0.01 mm to 0.05 mm. In the case of a high-pressure homogenizer, the preferred pressure is from 100 bar to 1000 bar, more preferably from 400 bar to 700 bar.

(Surface treatment process)
By performing surface treatment on the composite metal hydroxide after wet pulverization, the dispersibility in the resin when added, kneaded, and dispersed in the resin can be improved. For the surface treatment, a wet method or a dry method can be used. In consideration of processing uniformity, a wet method is preferably used. The slurry after the wet pulverization is dehydrated, washed with deionized water having a weight 20 times the solid content, and then suspended in deionized water. The temperature of the slurry after suspension is controlled, and a surface treatment agent dissolved under stirring is added. The temperature during the surface treatment is appropriately adjusted to a temperature at which the surface treatment agent is dissolved.

  Examples of the surface treatment agent include an anionic surfactant, a cationic surfactant, a phosphate ester treatment agent, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a silicone treatment agent, and sodium silicate. At least one selected from can be used. From the viewpoint of improving acid resistance, a preferred surface treatment agent is a combination of sodium silicate and a cationic surfactant. The total amount of the surface treatment agent is preferably 0.01 to 20% by weight, more preferably 0.5 to 10% by weight, based on the weight of the composite metal hydroxide.

(Drying process)
The slurry after the surface treatment is dehydrated, washed with deionized water having a weight 20 times the solid content, and then dried to obtain the composite metal hydroxide of the present invention. The drying method can be hot air drying, vacuum drying, or the like, but is not particularly limited.

<Method for producing composite metal oxide>
The composite metal oxide of the present invention can be obtained by firing the composite metal hydroxide of the present invention. After firing, a surface treatment is performed by a dry method or a wet method, whereby aggregation of primary particles can be prevented and a composite metal oxide having a high monodispersity can be obtained.

(Baking process)
The composite metal oxide of the present invention can be obtained by firing the composite metal hydroxide of the present invention at 400 to 1000 ° C. for 1 to 10 hours. A more preferable firing temperature is 450 to 900 ° C, more preferably 500 to 800 ° C. When the firing temperature is 400 ° C. or lower, magnesium oxide is not generated, and when the firing temperature is 1000 ° C. or higher, the primary particles are coarsened by sintering. A more preferable firing time is 1 to 8 hours, and further preferably 1 to 6 hours. If the firing time is less than 1 hour, it is not sufficient to produce magnesium oxide, and if it is 10 hours or more, the primary particles are coarsened by sintering, which is not preferable.

(Surface treatment process)
By performing surface treatment on the composite metal oxide after firing, the dispersibility in the resin when added, kneaded, and dispersed in the resin can be improved. For the surface treatment, a wet method or a dry method can be used. In consideration of processing uniformity, a wet method is preferably used. The surface treatment agent in which the powder after firing is dispersed in an alcohol solvent and dissolved under stirring is added. The temperature during the surface treatment is appropriately adjusted to a temperature at which the surface treatment agent is dissolved.

  Examples of the surface treatment agent include an anionic surfactant, a cationic surfactant, a phosphate ester treatment agent, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a silicone treatment agent, and sodium silicate. At least one selected from can be used. The addition amount of the surface treatment agent is preferably 0.01 to 20% by weight, more preferably 0.5 to 10% by weight, based on the weight of the composite metal hydroxide.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited only to these examples. In the examples, each physical property was measured by the following method.

(A) Average width of primary particles After adding a sample to ethanol and performing ultrasonic treatment for 5 minutes, an arbitrary 100 crystals using a scanning electron microscope (SEM) (manufactured by JEOL, JSM-7600F) The horizontal width of the primary particles was measured, and the arithmetic average was taken as the average primary particle width. The horizontal width of the primary particles is measured by measuring the diameter of the particles when the primary particles are hexagonal plate-like plate surfaces as indicated by arrows in FIG.

(B) Average width of secondary particles After adding the sample to ethanol and sonicating for 5 minutes, the particle size distribution was measured using a dynamic scattering particle size analyzer (ELSZ-2000S, manufactured by Otsuka Electronics), The number average diameter was defined as the average width of the secondary particles. That is, the diameter of the sphere when the secondary particles were considered to be encapsulated in the sphere was measured as the lateral width of the secondary particles, and the number average was taken as the average lateral width of the secondary particles.

(C) Monodispersion degree It calculated from the value of (a) and (b) based on the following formula | equation. Monodispersity (%) = (Average width of primary particles / Average width of secondary particles) × 100

(D) Determination of chemical composition After heating and dissolving the sample in nitric acid, Mg, Mn, Ni and Zn were quantified by chelate titration.

(E) Quantification of surface treatment amount (silicic acid) After heating and dissolving a sample using sulfuric acid and nitric acid,
The coating amount of silicic acid (as SiO ₂ ) relative to the weight of the sample was calculated.
(Stearic acid) The coating amount of stearic acid relative to the weight of the sample was calculated by the ether extraction method.
(Cationic surfactant) After extracting the nitrogen content of the sample by the Kjeldahl method, the nitrogen content was measured from the absorbance using a spectrophotometer. From the nitrogen content in the sample, the coating amount of the cationic surfactant relative to the weight of the sample was calculated.

(F) Acid resistance test method for powder 2 mL of ethanol at 32 ° C. and a rotor are placed in a beaker kept at 32 ° C., and the beaker is immersed in a thermostatic bath (32 ° C.) to start stirring. After 1 minute, 0.1 g of the sample is charged. One minute after the sample is added, 40 mL of water at 32 ° C. is added, and the set of pH meter electrode and burette is immersed in the beaker. One minute after the addition of water, an automatic titrator (manufactured by Toa DKK Corporation) is used, and 0.1N hydrochloric acid is added so that the pH of the test slurry is always 4.0 and the temperature is 32 ° C. The titration is completed when 5.15 mL of 0.1N hydrochloric acid is added. Acid resistance was evaluated by the time from the start to the end of 5.15 mL of 0.1N hydrochloric acid. The longer the time, the better the acid resistance.

(G) Flame retardancy test method for resin composition (UL94 vertical test (1/8 inch))
110 parts by weight of each sample was added to 100 parts by weight of polyethylene to prepare a resin composition. Polyethylene and each sample are melt-kneaded at 150 ° C. using a plast mill (BRABENDER), and the resulting resin composition is press-molded (Shindo Metal SF hydraulic press). Created. The flame retardancy of the resin composition was measured according to the UL94 vertical test method (1/8 inch). V-0, V-1, and V-2 standards are assigned in order of increasing flame retardancy. Those that do not meet the flame retardant standards are considered non-standard.

(H) Acid resistance test method of resin composition (carbon dioxide gas blowing test)
The test piece prepared in (g) was impregnated with 500 mL of deionized water, the temperature was maintained at 20 ° C., and carbon dioxide gas was blown in at a rate of 500 mL / min, and maintained for 24 hours. The acid resistance was evaluated by the Mg concentration in the solution after holding. The lower the Mg concentration in the solution, the better the acid resistance.

(Raw material adjustment process)
Reagent grade magnesium chloride and reagent grade nickel chloride were dissolved in deionized water to prepare a composite metal salt aqueous solution with Mg = 0.9 mol / L and Ni = 0.1 mol / L. On the other hand, reagent grade sodium hydroxide was dissolved in deionized water to prepare an aqueous alkali metal hydroxide solution with Na = 2 mol / L.

(Reaction process)
Each solution was continuously supplied to the reaction vessel at 20 mL / min using a metering pump to cause a coprecipitation reaction. The reaction tank is made of stainless steel and overflows with a capacity of 500 mL, and 300 mL of deionized water is previously added to this reaction tank, the temperature is adjusted to 30 ° C., and the mixture is stirred at 500 rpm using a stirrer. Similarly, the raw material whose temperature was adjusted to 30 ° C. was supplied to the reaction vessel, and the flow rate was adjusted so that the reaction pH was 10.3.

(Aging process)
The obtained slurry was temperature-controlled at 30 ° C. and aged for 10 hours while stirring at 300 rpm. The reaction product was filtered and washed with deionized water, and then the cake was dispersed in deionized water to obtain a slurry.

(Wet grinding process)
The slurry was wet pulverized using a bead mill (Hiroshima Metal & Machinery, Ultra Apex Mill). 400 mL of a slurry with a concentration of 0.5 mol / L was circulated at 200 mL / min, and pulverized for 20 minutes at a diameter of 0.03 mm beads and a rotation speed of 400 Hz. The ground slurry was filtered with suction and washed with deionized water . The cake was put into a hot air dryer, dried at 110 ° C. for 12 hours, and then pulverized to obtain a composite metal hydroxide sample 1 of the present invention. The experimental conditions of Sample 1 are shown in Table 1, and the chemical composition, average lateral width of primary particles, average lateral width of secondary particles, monodispersity, and acid resistance test results are shown in Table 2. FIG. 3 shows an SEM photograph of Sample 1 at a magnification of 100,000.

  In the raw material preparation step of Example 1, a sample was prepared in the same manner except that reagent grade zinc chloride was used instead of reagent grade nickel chloride to obtain the composite metal hydroxide sample 2 of the present invention. It was.

  The composite metal hydroxide sample of the present invention was prepared in the same manner as in the raw material preparation step of Example 1, except that reagent grade manganese chloride (2) was used instead of reagent grade nickel chloride. 3 was obtained.

  In the raw material preparation step of Example 1, a sample was prepared in the same manner except that the concentration of the composite metal salt aqueous solution was Mg = 0.7 mol / L, Ni = 0.3 mol / L, and the composite metal water of the present invention was used. An oxide sample 4 was obtained.

  In the reaction step of Example 1, a sample was prepared in the same manner except that the pH during the reaction was set to 9.3 to obtain a composite metal hydroxide sample 5 of the present invention.

  In the reaction step of Example 1, a sample was prepared in the same manner except that the pH during the reaction was set to 11.6 to obtain a composite metal hydroxide sample 6 of the present invention.

  In the aging step of Example 1, a sample was prepared in the same manner except that the aging temperature was set to 60 ° C. to obtain a composite metal hydroxide sample 7 of the present invention.

  In the aging step of Example 1, a sample was prepared in the same manner except that the aging temperature was set to 10 ° C. to obtain a composite metal hydroxide sample 8 of the present invention.

  In the aging step of Example 1, a sample was prepared in the same manner except that the aging time was 3 hours, and a composite metal hydroxide sample 9 of the present invention was obtained.

  In the aging step of Example 1, a sample was prepared in the same manner except that the aging time was set to 20 hours to obtain a composite metal hydroxide sample 10 of the present invention.

  In Example 1, instead of the bead mill, a sample was prepared in the same manner except that wet pulverization was performed using a high-pressure homogenizer (manufactured by SMT, LAB1000) to obtain the composite metal hydroxide sample 11 of the present invention. It was. 400 mL of slurry having a concentration of 0.5 mol / L was circulated at 200 mL / min, and wet pulverization was performed at 500 bar for 20 minutes.

(Surface treatment process)
Using 4% by weight of reagent grade 1 sodium silicate solution of 4% by weight relative to the composite metal hydroxide, make up to 50 mL with deionized water, that is, add deionized water to 50 mL (hereinafter, Similarly, a sodium silicate-containing treatment solution was obtained. A 1% by weight reagent grade 1 dioleyldimethylammonium chloride solution with respect to the composite metal hydroxide was diluted to 50 mL with deionized water to obtain a dioleyldimethylammonium chloride treatment solution.

In Example 1, the sodium silicate-containing treatment liquid heated to 80 ° C. was added to the slurry after wet pulverization, and the mixture was stirred and held at 80 ° C. for 20 minutes. Subsequently, a dioleyldimethylammonium chloride treatment solution heated to 80 ° C. was added, and the mixture was stirred and held at 80 ° C. for 20 minutes. After cooling the surface-treated slurry to 30 ° C., suction filtration and deionized water washing were performed. Thereafter, the cake was put into a hot air dryer, dried at 110 ° C. for 12 hours, and then pulverized to obtain a composite metal hydroxide sample 12 of the present invention.

  A sample was prepared in the same manner except that No. 3 sodium silicate was used alone in the surface treatment step of Example 12 to obtain a composite metal hydroxide sample 13 of the present invention.

  In the surface treatment process of Example 12, a sample was prepared in the same manner except that dioleyldimethylammonium chloride was used alone to obtain a composite metal hydroxide sample 14 of the present invention.

  In the surface treatment step of Example 12, a sample was prepared in the same manner except that 1% by weight of sodium stearate was used instead of sodium silicate, and the composite metal water of the present invention was used. An oxide sample 15 was obtained.

  In the surface treatment step of Example 12, a sample was prepared in the same manner except that 1% by weight of sodium stearate was used alone with respect to the composite metal hydroxide, and the composite metal hydroxide sample of the present invention was used. 16 was obtained.

(Comparative Example 1)
In the raw material preparation step of Example 1, a sample was prepared in the same manner except that reagent grade magnesium chloride was used alone, and Sample 17 was obtained.

(Comparative Example 2)
A sample was prepared in the same manner as in Example 1 except that the pH during the reaction was set to 8.5.

(Comparative Example 3)
In the aging step of Example 1, a sample was prepared in the same manner except that the aging time was 30 minutes, and Sample 19 was obtained.

(Comparative Example 4)
In the aging step of Example 1, a sample was prepared in the same manner except that the aging temperature was 120 ° C., and Sample 20 was obtained.

(Comparative Example 5)
A sample was prepared in the same manner as in Example 1 except that the aging step was omitted, and a sample 21 was obtained.

(Comparative Example 6)
A sample was prepared in the same manner as in Example 1 except that the wet pulverization step was omitted, and a sample 22 was obtained.

  From Tables 1 and 2, it can be seen that the composite metal hydroxide of the present application has an average primary particle width of 200 nm or less and a monodispersity of 50% or more. Compared with the magnesium hydroxide of Comparative Example 1, the composite metal hydroxide of Example 1 has a significantly improved powder acid resistance while maintaining a high degree of monodispersity. The samples of Examples 12 to 16 subjected to surface treatment show higher monodispersity and powder acid resistance than the samples without surface treatment. In particular, Example 12 using sodium silicate and dioleyldimethylammonium chloride shows a significant improvement in monodispersity and acid resistance.

  110 parts by weight of the powder sample 1 prepared in Example 1 was added to 100 parts by weight of polyethylene to produce a resin composition. Polyethylene (manufactured by Nippon Polyethylene, Novatec LL UF-240) and a powder sample are melt-kneaded at 150 ° C. using a plast mill (manufactured by BRABENDER), and the resulting resin composition is press-molded (Shindo Metal Co., Ltd. A test piece was prepared by performing a formula SF type hydraulic press. Table 3 shows the results of the flame retardancy test and the acid resistance test.

  A test piece was prepared in the same manner as in Example 17 using the powder sample 2 prepared in Example 2.

  Using the powder sample 3 prepared in Example 3, a test piece was prepared in the same manner as in Example 17.

  Using the powder sample 4 prepared in Example 4, a test piece was prepared in the same manner as in Example 17.

  A test piece was prepared in the same manner as in Example 17 using the powder sample 5 prepared in Example 5.

  Using the powder sample 6 produced in Example 6, a test piece was produced in the same manner as in Example 17.

  A test piece was prepared in the same manner as in Example 17 using the powder sample 7 prepared in Example 7.

  A test piece was prepared in the same manner as in Example 17 using the powder sample 8 prepared in Example 8.

  A test piece was prepared in the same manner as in Example 17 using the powder sample 9 prepared in Example 9.

  Using the powder sample 10 produced in Example 10, a test piece was produced in the same manner as in Example 17.

  Using the powder sample 11 produced in Example 11, a test piece was produced in the same manner as in Example 17.

  Using the powder sample 12 produced in Example 12, a test piece was produced in the same manner as in Example 17.

  Using the powder sample 13 produced in Example 13, a test piece was produced in the same manner as in Example 17.

  Using the powder sample 14 produced in Example 14, a test piece was produced in the same manner as in Example 17.

  Using the powder sample 15 produced in Example 15, a test piece was produced in the same manner as in Example 17.

  A test piece was prepared in the same manner as in Example 17 using the powder sample 16 prepared in Example 16.

(Comparative Example 7)
Using the powder sample 17 produced in Comparative Example 1, a test piece was produced in the same manner as in Example 17.

(Comparative Example 8)
Using the powder sample 18 produced in Comparative Example 2, a test piece was produced in the same manner as in Example 17.

(Comparative Example 9)
A test piece was prepared in the same manner as in Example 17 using the powder sample 19 prepared in Comparative Example 3.

(Comparative Example 10)
Using the powder sample 20 produced in Comparative Example 4, a test piece was produced in the same manner as in Example 17.

(Comparative Example 11)
A test piece was prepared in the same manner as in Example 17 using the powder sample 21 prepared in Comparative Example 5.

(Comparative Example 12)
A test piece was prepared in the same manner as in Example 17 using the powder sample 22 prepared in Comparative Example 6.

  From Table 3, the resin composition containing the composite metal hydroxide of the present invention satisfies the V-0 or V-1 standard in the UL94 vertical test (1/8 inch), and in the carbon dioxide blowing test, Mg resin It can be seen that there is little elution of.

(Baking process)
The powder sample 1 produced in Example 1 was fired at 500 ° C. for 1 hour in a siliconite electric furnace in an air atmosphere. After cooling, the mixture was pulverized using a mortar to obtain a composite metal oxide sample 23 of the present invention. The experimental conditions of Sample 23 are shown in Table 4, and the chemical composition, average primary particle width, secondary particle average width, monodispersity, and acid resistance test results are shown in Table 5. FIG. 4 shows an SEM photograph of sample 23 at a magnification of 100,000.

  A composite metal oxide sample 24 of the present invention was obtained in the same manner as in Example 33 except that the firing temperature was 800 ° C.

  A composite metal oxide sample 25 of the present invention was obtained in the same manner as in Example 33 except that the firing time was 8 hours.

(Surface treatment process)
1% by weight of reagent primary stearic acid with respect to the composite metal oxide was dissolved in 50 mL of ethanol to obtain a stearic acid-containing treatment solution.

  In Example 33, the fired composite metal oxide was dispersed in an ethanol solvent under stirring, and the temperature was adjusted to 60 ° C. Similarly, a stearic acid-containing treatment liquid heated to 60 ° C was added, and the mixture was stirred and held at 60 ° C for 20 minutes. After the surface-treated slurry was cooled to 30 ° C., suction filtration was performed. The cake was naturally dried and then pulverized to obtain a composite metal oxide sample 26 of the present invention.

(Comparative Example 13)
A sample 27 was obtained in the same manner as in Example 33 except that the firing temperature was 1200 ° C.

(Comparative Example 14)
A sample 28 was obtained in the same manner as in Example 33 except that the firing time was 12 hours.

(Comparative Example 15)
In Example 33, in place of the powder sample 1 produced in Example 1, Sample 29 produced in Comparative Example 1 was prepared in the same manner except that it was baked at 500 ° C. for 1 hour in an air atmosphere in a siliconite electric furnace. Got.

  From Table 4 and Table 5, it can be seen that the composite metal oxide of the present application has a primary particle size of less than 200 nm, a monodispersity of 50% or more, and high acid resistance. In particular, sample 26 (Example 36) surface-treated with stearic acid exhibits high acid resistance. It can be seen that Sample 27 (Comparative Example 13) and Sample 28 (Comparative Example 14) have large primary particles grown by sintering, and Sample 29 (Comparative Example 15) has poor acid resistance of the powder.

  By compounding the composite metal hydroxide of the present invention into a separator of a lithium ion battery, the reaction with hydrogen fluoride can be suppressed while suppressing the film thickness of the separator, and the safety of the battery can be improved. Further, the composite metal hydroxide of the present invention can be suitably used as a flame retardant. Since the fine particles are highly dispersed, the amount of the resin can be reduced, and the acid resistance of the resin can be improved.

  The composite metal hydroxide of the present invention can be suitably used for various applications such as an antibacterial agent, an oral bactericide, a heat conductive filler, a fine ceramic raw material, and an adsorbent. Further, by firing the composite metal hydroxide of the present invention, a composite metal oxide having fine particles, high dispersion and high acid resistance can be produced. The oxides are fine particles and highly dispersed, so they are used for pharmaceutical gastrointestinal drugs, acid acceptors for synthetic rubbers and adhesives, thickeners for FRP production, additives for producing electrical steel sheets, heat conductive fillers, magnesia grinding stone materials It can be suitably used for various applications such as fine ceramic raw materials, brake materials and adsorbents.

Claims (13)

A composite metal hydroxide represented by the following formula (1) that satisfies the following (A) and (B).
(Mg) 1-X (M2 +) X (OH) 2 (1)
(Wherein, M2 + is at least one divalent metal selected from Cr, Mn, Fe, Co, Ni, Cu and Zn, and the range of X is 0 <X <0.5.)
(A) The average lateral width of primary particles by SEM method is 10 nm or more and less than 200 nm;
(B) The monodispersity represented by the following formula is 50% or more;
Monodispersity (%) = (Average width of primary particles by SEM method / Average width of secondary particles by dynamic light scattering method) × 100 2. The composite metal hydroxide according to claim 1, wherein (A) an average lateral width of primary particles by SEM method is 10 nm or more and less than 100 nm. 2. The composite metal hydroxide according to claim 1, wherein (A) an average lateral width of primary particles by SEM method is 10 nm or more and less than 50 nm. The composite metal hydroxide according to claim 1, wherein (B) the monodispersity is 80% or more. The composite metal hydroxide according to claim 1, wherein the range of X in the formula (1) is 0.005 ≦ X ≦ 0.4. The composite metal hydroxide according to claim 1, wherein the range of X in the formula (1) is 0.01 ≦ X ≦ 0.2. The composite metal hydroxide according to claim 1, wherein M2 + in the formula (1) is Ni and / or Zn. One or more selected from the group consisting of anionic surfactants, cationic surfactants, phosphate ester treatment agents, silane coupling agents, titanate coupling agents, aluminum coupling agents, silicone treatment agents, and silicic acid. The composite metal hydroxide according to claim 1, which has been surface-treated. The composite metal hydroxide according to claim 1, which is surface-treated with silicic acid and a cationic surfactant. A composite metal oxide represented by the following formula (2) that satisfies the following (A) and (B).
(Mg) 1-X (M2 +) XO (2)
(Wherein, M2 + is at least one divalent metal selected from Cr, Mn, Fe, Co, Ni, Cu and Zn, and the range of X is 0 <X <0.5.)
(A) The average lateral width of primary particles by SEM method is 10 nm or more and less than 200 nm;
(B) The monodispersity represented by the following formula is 50% or more;
Monodispersity (%) = (Average width of primary particles by SEM method / Average width of secondary particles by dynamic light scattering method) × 100 The resin composition containing the composite metal hydroxide according to claim 1, based on 100 parts by weight of the resin. The following steps:
(1) Raw material preparation for obtaining a water-soluble composite metal salt aqueous solution by mixing a water-soluble magnesium salt aqueous solution and at least one water-soluble metal salt aqueous solution selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn Process,
(2) Reaction in which the water-soluble composite metal salt aqueous solution obtained in (1) and the alkali metal hydroxide aqueous solution are reacted in a pH 9.0 to pH 12.0 range to obtain a slurry containing the product. Process,
(3) A ripening step of stirring and holding the slurry containing the product obtained in (2) at 0 to 100 ° C. for 1 to 24 hours,
(4) A wet pulverization step for wet pulverizing the slurry containing the product after aging obtained in (3),
The manufacturing method of the composite metal hydroxide of Claim 1 containing this. The following steps:
(1) Raw material preparation for obtaining a water-soluble composite metal salt aqueous solution by mixing a water-soluble magnesium salt aqueous solution and at least one water-soluble metal salt aqueous solution selected from Cr, Mn, Fe, Co, Ni, Cu, and Zn Process,
(2) Reaction in which the water-soluble composite metal salt aqueous solution obtained in (1) and the alkali metal hydroxide aqueous solution are reacted in a pH 9.0 to pH 12.0 range to obtain a slurry containing the product. Process,
(3) A ripening step of stirring and holding the slurry containing the product obtained in (2) at 0 to 100 ° C. for 1 to 24 hours,
(4) A wet pulverization step for wet pulverizing the slurry containing the product after aging obtained in (3),
(5) A drying step of dehydrating the slurry after wet pulverization obtained in (4) and drying the resulting cake to obtain a composite metal hydroxide,
(6) A firing step of firing the composite metal hydroxide obtained in (5) at 400 to 1000 ° C. for 1 to 10 hours,
The manufacturing method of the composite metal oxide of Claim 10 containing this.

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