Hydrotalcite and resin compositions for electronic materials

Abstract

The present invention provides hydrotalcite that does not cause thickening of the resin or a decrease in its mechanical properties, and that exhibits excellent anion scavenging performance in the resin. [Solution] Hydrotalcite containing magnesium and aluminum, wherein the hydrotalcite is particulate and the primary particles have a plate-like shape. The primary particles have an average plate diameter with a major axis of 400-700 nm and an aspect ratio (average plate diameter major axis / average plate diameter minor axis) of 1.4-2.0. Hydrotalcite for electronic materials characterized by the following features.

Description

[Technical Field]

[0001] This invention relates to hydrotalcite for electronic materials and resin compositions for electronic materials. [Background technology]

[0002] Against the backdrop of growing concern for environmental issues in recent years, a shift in energy sources from fossil fuels to electricity is progressing in various fields. The automotive sector is one such example, with a global shift from conventional vehicles with internal combustion engines to electric vehicles. Inverters for electric vehicles are being designed to operate at higher voltages (800-1000V) to improve acceleration performance, extend driving range, and enable faster charging. Achieving this requires power modules with excellent dielectric strength, which in turn necessitates reducing the anion concentration in the epoxy resin used as a semiconductor encapsulant. A hydrotalcite calcined product represented by a specific formula and / or an inorganic ion exchanger obtained by coating hydrotalcite with a metal oxide has been disclosed as a material for reducing the anion concentration in epoxy resin (see Patent Document 1). Furthermore, it has been disclosed that hydrotalcite represented by a specific formula, having a predetermined BET specific surface area and exhibiting a predetermined peak in powder X-ray diffraction, may be used as an inorganic ion scavenger for resin (see Patent Document 2), or that hydrotalcite represented by a specific formula, having a predetermined BET specific surface area and median diameter of secondary particles, and exhibiting a hydrotalcite peak in powder X-ray diffraction, may be used as an anion scavenger for resin (see Patent Document 3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2005-1902 [Patent Document 2] International Publication No. 2008 / 136272 [Patent Document 3] International Publication No. 2011 / 099378 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] As described above, hydrotalcite is used as an anion scavenger in resins, but with the increasing voltage of electric vehicles, there is a need for further improvement in anion scavenging capacity. Hydrotalcite can reduce the anion concentration in resins by exchanging interlayer anions (carbonate ions) with anions in the resin. Fine hydrotalcite is sometimes used to enhance anion scavenging capacity, but when fine hydrotalcite is added to resins, the resin becomes thicker and its mechanical properties deteriorate, limiting the amount of hydrotalcite that can be added. As a result, it becomes necessary to reconsider the resin formulation and processing methods, making it impractical. There are also methods to improve anion scavenging capacity by using calcined hydrotalcite or semi-calcined hydrotalcite from which crystal water has been removed, but these hydrotalcites are highly hygroscopic, which leads to a decrease in the dimensional stability of the encapsulant and a reduction in reliability. Because such finely milled hydrotalcite, calcined hydrotalcite, and semi-calcined hydrotalcite products cannot sufficiently improve the anion-capturing ability of resins, and also affect the properties of resin compositions to which hydrotalcite is added, there is a need to develop hydrotalcite that does not cause increased viscosity or a decrease in mechanical properties of the resin, and that has excellent anion-capturing performance in resins.

[0005] In view of the above situation, the present invention aims to provide hydrotalcite that does not cause thickening of the resin or deterioration of its mechanical properties, and that has excellent anion scavenging performance in the resin. [Means for solving the problem]

[0006] The inventors investigated hydrotalcite that does not cause thickening or deterioration of mechanical properties in resins and has excellent anion capture performance in resins. They found that hydrotalcite containing magnesium and aluminum elements, in which the primary particles are plate-like particles of a predetermined shape, does not cause thickening or deterioration of mechanical properties when added to resins and has particularly excellent anion capture performance in resins. Furthermore, they found that by using this hydrotalcite as an anion capture agent in resins, the anion concentration is sufficiently reduced, resulting in a resin composition for electronic materials suitable as a encapsulant for semiconductors intended for use at high voltages, thus completing the present invention.

[0007] In other words, the present invention is as follows. [1] Hydrotalcite containing the element magnesium and the element aluminum, The hydrotalcite is particulate, and the primary particles have a plate-like shape. The primary particles have an average plate diameter with a major axis of 400-700 nm and an aspect ratio (average plate diameter major axis / average plate diameter minor axis) of 1.4-2.0. Hydrotalcite for electronic materials characterized by the following features.

[0008] [2] The hydrotalcite is given by the following formula (1): Mg 1-x Al x (OH)2(CO3) x / 2 nH2O (1) Hydrotalcite for electronic materials as described in [1], characterized by being expressed as follows: (wherein x is a number between 0.26 and 0.40, and n is a number greater than or equal to 0.10).

[0009] [3] Hydrotalcite for electronic materials according to [1] or [2], characterized in that at least a portion of the surface is coated with a compound having silicon atoms and / or fatty acid groups.

[0010] A resin composition for electronic materials, comprising a hydrotalcite according to any one of [4][1] to [3] and a resin component.

Effects of the Invention

[0011] The hydrotalcite for electronic materials of the present invention does not cause thickening of the resin or deterioration of mechanical properties, and is particularly excellent in the ability to capture anions in the resin. Therefore, the resin composition containing this hydrotalcite for electronic materials and the resin can be suitably used as a sealing agent for semiconductors assumed to be used at high voltages.

Brief Description of the Drawings

[0012] [Figure 1] It is a figure of the electron microscope observation result of the hydrotalcite obtained in Example 1. [Figure 2] It is a figure of the electron microscope observation result of the hydrotalcite obtained in Example 2. [Figure 3] It is a figure of the electron microscope observation result of the hydrotalcite obtained in Comparative Example 1.

Modes for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be specifically described. However, the present invention is not limited to the following description, and can be appropriately modified and applied without changing the gist of the present invention.

[0014] 1. Hydrotalcite for Electronic Materials The hydrotalcite for electronic materials of the present invention is a hydrotalcite containing a magnesium element and an aluminum element, which is in a particulate form and the primary particles have a plate-like shape. The primary particles have a major axis of the average plate surface diameter of 400 to 700 nm and an aspect ratio (major axis of the average plate surface diameter / minor axis of the average plate surface diameter) of 1.4 to 2.0. Hydrotalcite is composed of a cation layer consisting of divalent and trivalent metal ions and an anion layer consisting of anions that exist between the cation layers and compensate for the charges of the metal ions. By exchanging the anions present in the anion layer with the anions contained in the resin, the concentration of resin-derived anions such as chloride ions can be reduced. The anions inside the hydrotalcite particles are less likely to be exchanged compared to the anions on the particle surface. When the particles are spherical, it is difficult for the anions to be exchanged up to the inside of the hydrotalcite particles. On the other hand, when the hydrotalcite particles are plate-shaped, the anions inside the particles are also more easily exchanged, and the concentration of resin-derived anions in the resin can be efficiently reduced. Also, it is considered that the growth of the anion layer in the plate-shaped hydrotalcite contributes to the improvement of the ion exchange ability compared to spherical particles. Although the fired hydrotalcite with all anions between the cation layers removed to enhance the ability to capture resin-derived anions has an increased viscosity and is difficult to handle, the hydrotalcite for electronic materials of the present invention does not have such an increase in viscosity and is also excellent in terms of handleability. The hydrotalcite for electronic materials of the present invention is characterized in that the major axis of the average plate surface diameter of the primary primary particles having a plate shape is 400 to 700 nm, and the aspect ratio (major axis of the average plate surface diameter / minor axis of the average plate surface diameter) is 1.4 to 2.0. The reason why the hydrotalcite having primary particles with a plate shape having a major axis of the average plate surface diameter of 400 to 700 nm and a large difference between the major axis and the minor axis of the average plate surface diameter has a high anion exchange ability is that the plate surface shape with a high aspect ratio has a longer outer peripheral distance compared to a circular shape with the same area, so the contact frequency between the anions and the hydrotalcite increases. In addition, the shortest distance from the outer peripheral part to the center of the particle is shorter compared to a circular shape with the same area, so it is considered that ion exchange is likely to occur up to the center of the particle. The major axis of the average plate surface diameter of the primary particles of the hydrotalcite for electronic materials of the present invention may be 400 to 700 nm, but it is preferably 400 to 650 nm. More preferably, it is 405 to 600 nm, and still more preferably, it is 410 to 560 nm. In the present invention, the major axis of the average plate surface diameter of the primary particles means the maximum value of the distance between two points when two points are taken on the outer peripheral portion of the plate surface of the primary particles. The major axis of the average plate surface diameter of the primary particles of hydrotalcite can be measured by the method described in the examples below.

[0015] The aspect ratio (major axis of the average plate surface diameter / minor axis of the average plate surface diameter) of the primary particles of the hydrotalcite for the above electronic material is preferably 1.4 to 2.0, more preferably 1.4 to 1.9, still more preferably 1.4 to 1.8, and even more preferably 1.4 to 1.7. In the present invention, the minor axis of the average plate surface diameter of the primary particles means the distance between two points where a line perpendicular to the major axis passing through the central point of the major axis on the plate surface of the primary particles intersects the outer peripheral portion of the plate surface of the primary particles. The aspect ratio of the primary particles of hydrotalcite can be measured by the method described in the examples below.

[0016] The hydrotalcite for the above electronic material preferably has a BET specific surface area of 1 to 30 m 2 / g. When the BET specific surface area is within this range, it is difficult to thicken when the hydrotalcite is dispersed in the resin, so the fluidity can be maintained even at a high filling rate and the moldability can be maintained. The BET specific surface area is more preferably 3 to 20 m 2 [[ID= +18]] / g, still more preferably 5 to 15 m 2 / g. The BET specific surface area of hydrotalcite can be measured by the method described in the examples below.

[0017] The hydrotalcite for the electronic material of the present invention has the following formula (1): Mg 1-x Al x (OH)2(CO3) x / 2 ·nH2O (1) (In the formula, x is a number of 0.XX or more and 0.40 or less. n is a number of 0.10 or more.) It preferably has a composition represented by this. When it is such a composition, anion exchange is possible without impairing the resin properties In equation (1), x can be any number between 0.26 and 0.40, but it is preferably a number between 0.28 and 0.38. More preferably, it is a number between 0.30 and 0.35. In equation (1), n ​​can be any number greater than or equal to 0.10, but it is preferably a number greater than or equal to 0.20. More preferably, it is a number greater than or equal to 0.30. Also, n is usually a number less than or equal to 1.0.

[0018] The hydrotalcite for electronic materials of the present invention may be coated with a surface treatment agent. When coated with a surface treatment agent, its compatibility with the resin is improved, and it becomes possible to disperse the hydrotalcite more uniformly in the resin. By uniformly dispersing the hydrotalcite in the resin, the dielectric breakdown path is lengthened, which effectively suppresses short circuits when used under high voltage conditions. Both inorganic and organic compounds can be suitably used as surface treatment agents. Inorganic compounds are not particularly limited, but examples include oxides, hydroxides, sulfates, and carbonates of silicon, calcium, barium, strontium, aluminum, zirconium, cerium, and zinc. Organic compounds are not particularly limited, but examples include silicone oil, fatty acids and their metal salts, hydrogen dimethicone, alkylsilanes, alkoxysilanes, silane coupling agents, titanium coupling agents, aluminum coupling agents, amino acids, nylon, carbomers and their metal salts, polyacrylic acid, trimethylpropanol, triethylamine, and higher alcohols.

[0019] Among the surface treatment agents mentioned above, compounds having silicon atoms, fatty acids, and their metal salts are preferred as surface treatment agents for use in the present invention. In other words, it is preferable that the hydrotalcite for electronic materials of the present invention has at least a portion of its surface coated with a compound having silicon atoms and / or fatty acid groups. When it is coated with a compound having silicon atoms and / or fatty acid groups, it can be mixed more uniformly with the resin, and short circuits when used under high voltage conditions can be suppressed more effectively. Specific examples of compounds having silicon atoms and / or fatty acid groups will be described later in the method for producing hydrotalcite for electronic materials of the present invention.

[0020] In the case of the hydrotalcite for electronic materials of the present invention, where at least a portion of the surface is coated with a compound having silicon atoms and / or fatty acid groups, the amount of surface coating is not particularly limited, but for example, it is preferable that the proportion of the surface coating agent is 0.1 to 15% by mass, relative to 100% by mass of the total amount of hydrotalcite-type particles. More preferably, it is 0.5 to 5% by mass.

[0021] The hydrotalcite for electronic materials of the present invention exhibits excellent anion trapping performance in resins, making it suitable for use in semiconductor encapsulants where reducing anions that cause short circuits is required. In particular, it is especially suitable as a semiconductor encapsulant material for power semiconductors, where high voltages are used and the reduction of anions in the encapsulant is particularly important.

[0022] 2. Method for manufacturing hydrotalcite for electronic materials The method for producing hydrotalcite for electronic materials according to the present invention is not particularly limited, but it includes a first step of preparing a slurry containing all or part of the raw materials, a magnesium compound and an aluminum compound, and a carboxylic acid group-containing compound; a second step of wet grinding the slurry obtained in the first step; and after adding the remaining raw materials to the slurry obtained in the second step, hydrothermal treatment to obtain a BET specific surface area of ​​1 m². 2 / g~30m 2 It is preferable to manufacture it by a manufacturing method that includes a third step of synthesizing hydrotalcite in a quantity of / g. By manufacturing using this method, unlike fine hydrotalcite, fired hydrotalcite, or semi-fired hydrotalcite from which crystal water has been removed, hydrotalcite for electronic materials can be produced without altering the primary particle size, specific surface area, etc., compared to hydrotalcite for general resin compositions. Therefore, using this manufacturing method makes it easy to adjust the primary particle size, specific surface area, etc., of the produced hydrotalcite. Thus, the ease of adjusting the primary particle size, specific surface area, etc., is another advantage of the hydrotalcite for electronic materials of the present invention.

[0023] In the first step described above, the magnesium compound and aluminum compound used as raw materials can be any of magnesium, aluminum hydroxide, oxide, or carbonate. Just as both magnesium compounds and aluminum compounds are hydroxides or oxides, magnesium compounds and aluminum compounds may be of the same type or different types.

[0024] In the first step described above, it is preferable to use the magnesium compound and the aluminum compound such that the ratio of aluminum elements to the total number of moles of magnesium elements in the magnesium compound and aluminum elements in the aluminum compound is 26 to 40 mol%. Using them in such proportions makes it easier to produce hydrotalcite that satisfies the requirements of the present invention for hydrotalcite for electronic materials. The ratio of aluminum elements to the total number of moles of magnesium elements in the magnesium compound and aluminum elements in the aluminum compound is more preferably 28 to 38 mol%, and even more preferably 30 to 35 mol%.

[0025] The carboxylic acid group-containing compounds used in the first step above include saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid; hydroxycarboxylic acids such as lactic acid, malic acid, citric acid, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, and salicylic acid; benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, melitic acid, and silica. Examples include aromatic carboxylic acids such as periacids; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid; and oxocarboxylic acids such as pyruvic acid, phthalaldehyde acid, isophthalaldehyde acid, terephthalaldehyde acid, 6-formyl-2,3-dimethoxybenzoic acid, o-acetylbenzoic acid, m-acetylbenzoic acid, p-acetylbenzoic acid, o-benzoylbenzoic acid, m-benzoylbenzoic acid, p-benzoylbenzoic acid, and benzophenone-4,4'-dicarboxylic acid.

[0026] Water is preferred as the suspension medium for the slurry prepared in the first step described above. Other liquid media besides water may also be included in the suspension medium, as long as they do not adversely affect it.

[0027] The solid content of the slurry prepared in the first step described above is preferably 25% by mass or more. Grinding with a high-concentration slurry is advantageous in terms of production efficiency and wear of the grinding media. The solid content is preferably 30% by mass or more. There is no particular upper limit to the solid content as long as the concentration allows for sufficient wet grinding, but it is generally preferable that the solid content is 70% by mass or less. It is more preferable that the solid content is 60% by mass or less.

[0028] The concentration (or mass) of the above carboxylic acid group-containing compound is preferably 5 g or less per 100 g of solids, more preferably 3 g or less, and even more preferably 1 g or less.

[0029] The apparatus used for wet grinding in the second step described above is not particularly limited, but examples include bead mills, ball mills, tower mills, vibratory mills, planetary mills, supermicron mills, and colloidal mills. Wet grinding is performed by supplying the slurry to these grinders. Among these, bead mills are preferred because they can efficiently finely grind the particles. A bead mill is an apparatus that finely grinds and disperses particles in a slurry by colliding beads (grinding media) in a grinding chamber. Examples of beads include silicon nitride beads, titania beads, glass beads, alumina beads, steel balls, and stainless steel beads. Among these, titania beads, silicon nitride beads, and alumina beads are preferred.

[0030] The grinding time in the second step described above is not particularly limited, but can usually be selected as appropriate between a few minutes and several hours. If multiple poorly soluble raw materials are present in the suspension medium, they may all be mixed together and then wet-ground simultaneously in a single step, or one raw material may be wet-ground first, and then another raw material may be ground in stages. Alternatively, they may be wet-ground individually and then mixed together. Furthermore, it is not necessary to wet-ground all poorly soluble raw materials in the suspension medium; only a portion of them may be wet-ground.

[0031] The intercalation anions contained in hydrotalcite are not particularly limited, but carbonate ions are preferred. Carbonate ions can be supplied into the slurry as carbon dioxide or as salts such as bicarbonate or carbonate. The timing of adding carbon dioxide, bicarbonate, or carbonate to the mixture is not particularly limited; it may be added before the wet grinding in the second step described above, or it may be added after the wet grinding. In particular, it is preferred to add carbon dioxide, bicarbonate, or carbonate to the mixture obtained after wet grinding and mix it.

[0032] The hydrothermal treatment in the third step described above is not particularly limited, but is usually carried out in a heat-resistant container such as an autoclave. The processing temperature is not particularly limited, but is preferably 120 to 250°C, more preferably 130 to 230°C, and even more preferably 140 to 230°C. Furthermore, the internal pressure of the container during processing is not particularly limited, but is preferably 0.1 to 10 MPa, and more preferably 0.2 to 4 MPa. The processing time is not particularly limited, but is, for example, 1 to 6 hours, preferably 1 to 4 hours.

[0033] When producing hydrotalcite for electronic materials according to the present invention, in which at least a portion of the surface is coated with a compound having silicon atoms and / or fatty acid groups, the third step described above is followed by a surface treatment step in which the hydrotalcite is coated with a surface treatment agent having silicon atoms and / or fatty acid groups.

[0034] Examples of surface treatment agents having silicon atoms and / or fatty acid groups include higher fatty acids such as stearic acid, oleic acid, erucic acid, palmitic acid, and lauric acid; metal salts of these higher fatty acids such as lithium salts, sodium salts, and potassium salts; and silane coupling agents such as vinylethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, and γ-aminopropyltrimethoxysilane.

[0035] When performing surface treatment, it is preferable to surface-treat the hydrotalcite by adding the above-mentioned surface treatment agent in an amount of 0.1 to 15% by mass, preferably 0.5 to 5% by mass, relative to the hydrotalcite.

[0036] The surface treatment method is not particularly limited and can be any method that is appropriate, such as conventionally known wet or dry methods. When using the wet method, the surface treatment agent can be added as a solution or emulsion to a slurry containing hydrotalcite, and after thoroughly mixing while stirring and heating to a temperature up to 100°C as needed, the hydrotalcite can be filtered, washed with water, and dried.

[0037] After hydrothermal treatment, if necessary, processes such as filtering hydrotalcite from the slurry, washing, and drying can be carried out. For example, the slurry after hydrothermal treatment is preferably filtered to separate the solid (cake) containing hydrotalcite from the filtrate, and the recovered solid is washed with water as needed. There is no particular limit to the number of times it is washed with water. After that, the filtered solid is recovered and dried in an oven or the like, and the dried solid is dry-ground as needed to obtain the desired hydrotalcite.

[0038] The above manufacturing method may further include a step of contacting the filtrate with carbon dioxide. In the above manufacturing method, a carbonate is produced as a byproduct after the reaction. This carbonate can be reacted with carbon dioxide (CO2) to produce a bicarbonate (e.g., Na2CO3 → NaHCO3). This bicarbonate is recyclable and can be used directly as a raw material for new hydrotalcite. This is advantageous from both an environmental and economic standpoint.

[0039] 3.Resin composition for electronic materials The hydrotalcite for electronic materials of the present invention exhibits particularly excellent anion-capturing performance in resins. Therefore, a resin composition containing this hydrotalcite for electronic materials and a resin can be suitably used as a encapsulant for semiconductors intended for use at high voltages. A resin composition for electronic materials characterized by containing such hydrotalcite and a resin component is also one of the present inventions.

[0040] The proportion of hydrotalcite for electronic materials in the above-mentioned resin composition for electronic materials is not particularly limited, but it is preferably 0.01 to 20% by mass, based on 100% by mass of the resin composition for electronic materials. More preferably, it is 0.05 to 15% by mass, and even more preferably, 0.1 to 10% by mass.

[0041] Examples of resins included in the above-mentioned resin composition for electronic materials include epoxy resins, silicone resins, urethane resins, and phenolic resins.

[0042] The proportion of resin in the above-mentioned resin composition for electronic materials is not particularly limited, but it is preferably 80 to 99.99% by mass based on 100% by mass of the resin composition for electronic materials. More preferably, it is 85 to 99.95% by mass, and even more preferably, it is 90 to 99.9% by mass.

[0043] The above-mentioned resin composition for electronic materials may further contain a curing agent. Examples of curing agents include phenol curing agents, amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents.

[0044] The proportion of the curing agent is not particularly limited, but it is preferable that the ratio of the number of functional groups in the curing agent to the number of functional groups in the resin contained in the resin composition for electronic materials (number of functional groups in the curing agent / number of functional groups in the resin) is 0.5 to 2.0. More preferably, it is 0.6 to 1.3, and even more preferably, 0.8 to 1.2.

[0045] The above-mentioned resin composition for electronic materials may contain other components besides the resin, hydrotalcite for electronic materials, and curing agent. Examples of other components include inorganic fillers other than hydrotalcite for electronic materials, curing accelerators, flame retardants, colorants, etc.

[0046] The content of components other than the above-mentioned resin, hydrotalcite for electronic materials, and curing agent is preferably 40% by mass or less, based on 100% by mass of the resin composition for electronic materials. More preferably, it is 30% by mass or less, and even more preferably, 20% by mass or less. [Examples]

[0047] Specific examples are given below to illustrate the present invention in detail, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "wt%" mean "weight % (mass %)". The measurement methods for each physical property are as follows.

[0048] <Electron Microscope Observation> The shape of the particles was observed using a field emission scanning electron microscope (JEOL Ltd., JSM-7000F).

[0049] <Elemental analysis> The Mg, Zn, and Al content in each powder was measured using inductively coupled plasma (ICP) emission spectroscopy by the following method. The measurement was performed using a spectrometer (SII Corporation, ICP SPS3100) and the internal standard method with scandium (Sc) as the internal standard element. First, approximately 0.2 g of the sample was accurately weighed into a beaker, dissolved in approximately 5 mL of hydrochloric acid, and then packed into a 100 mL volumetric flask. The solution was then diluted to the correct volume with deionized water. This solution was then diluted 20 times for Mg content measurement and 10 times for Al content measurement, and a Sc standard solution was added to achieve a Sc concentration of 10 ppm. These solutions were used as test solutions, and measurements were taken under the following conditions. The obtained raw data was then used to calculate the Mg, Zn, and Al content under the following calculation conditions. -Measurement conditions- Using a spectrometer (SII Corporation, ICP SPS3100), calibration curves were created at wavelengths of 279.55 nm (Mg), 213.86 nm (Zn), 396.15 nm (Al), and 361.49 nm (Sc), after which the samples were measured. The concentrations of the samples used for the calibration curve are as follows: Mg(ppm)=50,40,30,20,10 Zn(ppm)=20,16,12,8,4 Al(ppm) = 50, 40, 30, 20, 10 Use 5 points of each. For all calibration curve samples, an Sc standard solution should be added to achieve a Sc concentration of 10 ppm. The calculation conditions are as follows: Each content (%) = Raw data × 100 / Sample weight (g) × Dilution ratio / 10000 Furthermore, using the Mg and Al content (weight %) obtained above, the following calculation formula is used: x=(Al content / 26.982)÷{(Mg content / 24.305)+(Zn content / 65.38)+(Al content / 26.982)} Therefore, the value corresponding to x in equation (1) above was determined.

[0050] <Average board diameter, aspect ratio> For the powders (samples) obtained in the examples and comparative examples, electron microscope images were taken using a field emission scanning electron microscope (JEOL Ltd., JSM-7000F) so that approximately 50 to 10,000 particles were visible. The average of the major axis of the plate surface diameter of 20 particles located on a randomly drawn straight line on these electron microscope images was taken as the average major axis of the plate surface diameter of each powder. The minor axis of the average plate surface diameter (average value of the minor axis of the plate surface diameter of 20 particles) was calculated in the same manner, and the aspect ratio was determined by (major axis of average plate surface diameter / minor axis of average plate surface diameter). If it was difficult to measure the plate surface diameter, the image was taken with an appropriate magnification and used for measurement. This operation was repeated 10 times, changing the powder to be photographed for each example and comparative example, and the average of the obtained aspect ratios was calculated. <Specific surface area (SSA)> The specific surface area (SSA) was measured under the following conditions. Equipment used: Mountech Macsorb Model HM-1220 Atmosphere: Nitrogen gas (N2) Degassing conditions for the external degasser: 105°C - 15 minutes Degassing conditions for the specific surface area measuring device: 105℃-5min

[0051] <Chloride ion scavenging capacity> In this invention, chloride ion scavenging capacity is measured using hydrochloric acid. Method for measuring the chloride ion scavenging capacity of hydrotalcite: Place 2 g of hydrotalcite and 50 ml of 0.1 mol / L hydrochloric acid aqueous solution in a polyethylene bottle, seal it tightly, and stir at 40°C for 4 hours. Then, filter the solution and measure the chloride ion concentration in the filtrate using ion chromatography (Thermo Fisher Scientific Co., Ltd., ICS-2000). The chloride ion scavenging capacity of hydrotalcite is determined by comparing the chloride ion concentration measured using the same procedure without hydrotalcite with the previously measured value, using the following formula (1). (Q1-Q2) / Q1×100 (1) Q1: Chloride ion concentration without hydrotalcite Q2: Chloride ion concentration when hydrotalcite is added

[0052] Example 1 1006 g of magnesium hydroxide and 598.3 g of aluminum hydroxide were placed in a 5 L container, and then water was added until the total volume was 3 L. After adding 9.0 g of acetic acid (reagent), the mixture was stirred for 10 minutes to prepare a slurry. This slurry was supplied to a wet grinding apparatus (DinoMill MULTILAB, manufactured by Shinmaru Enterprises, Ltd., filled with titania beads) and wet-ground for 28 minutes (residence time). The slurry was then removed from the wet grinding apparatus. 1 L of the ground slurry was mixed with sodium carbonate in an amount equivalent to 1 / 2 mole per mole of magnesium hydroxide, and the total volume was adjusted with water to 8 L. The mixture was then stirred for 10 minutes. 3 L of the slurry was transferred to an autoclave and subjected to hydrothermal treatment at 170°C for 2 hours. The solid was then filtered off. The resulting filter cake was washed with 9 L of deionized water at 35°C. The washed cake was dried at 100°C for 24 hours and then ground to obtain a plate-shaped solid product. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1. Figure 1 shows the results of electron microscope observation of the obtained product.

[0053] Example 2 894.7g of magnesium hydroxide and 598.3g of aluminum hydroxide were placed in a 5L container, and then water was added until the total volume was 3L. After adding 9.0g of acetic acid (reagent), the mixture was stirred for 10 minutes to prepare a slurry. This slurry was supplied to a wet grinding apparatus (DinoMill MULTILAB, manufactured by Shinmaru Enterprises, Ltd., filled with titania beads) and wet-ground for 28 minutes (residence time). The slurry was then removed from the wet grinding apparatus. 1L of the ground slurry was mixed with sodium carbonate in an amount equivalent to 1 / 2 mole per mole of magnesium hydroxide, and the total volume was adjusted with water to 8L. The mixture was then stirred for 10 minutes. 3L of the slurry was transferred to an autoclave and subjected to hydrothermal treatment at 170°C for 2 hours. The solid was then filtered off. The resulting filter cake was washed with 9L of deionized water at 35°C. The washed cake was dried at 100°C for 24 hours and then ground to obtain a plate-shaped solid product. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1. Figure 2 shows the results of electron microscopy observation of the obtained product.

[0054] Comparative Example 1 A metal solution was prepared by mixing 862 ml of a magnesium sulfate aqueous solution with a Mg concentration of 2.6 mol / L and 475 ml of an industrial aluminum sulfate aqueous solution with an Al concentration of 2.1 mol / L, and adding water to make a total volume of 1.5 L. Separately, an alkaline solution was prepared by mixing 277.5 ml of 18N NaOH solution and 158.66 g of industrial sodium carbonate, and adding water to make a total volume of 1.5 L. The metal solution and the alkaline solution were added simultaneously under stirring and stirred for approximately 30 minutes. Next, the resulting coprecipitation suspension was subjected to hydrothermal treatment at 170°C for 2 hours. The solid was then separated by filtration. The obtained filtration cake was washed with 9 L of deionized water at 35°C. The washed cake was dried at 100°C for 24 hours and then pulverized to obtain a plate-like solid product. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1. The electron microscope observation results of the obtained product are shown in Figure 3.

[0055] Comparative Example 2 1006 g of magnesium hydroxide and 448.7 g of aluminum hydroxide were placed in a 5 L container, and then water was added until the total volume was 3 L. After adding 9.0 g of acetic acid (reagent), the mixture was stirred for 10 minutes to prepare a slurry. This slurry was supplied to a wet grinding apparatus (DinoMill MULTILAB, manufactured by Shinmaru Enterprises, Ltd., filled with titania beads) and wet-ground for 28 minutes (residence time). The slurry was then removed from the wet grinding apparatus. 1 L of the ground slurry was mixed with sodium carbonate in an amount equivalent to 1 / 2 mole per mole of magnesium hydroxide, and the total volume was adjusted with water to 8 L. The mixture was then stirred for 10 minutes. 3 L of the slurry was transferred to an autoclave and hydrothermally treated at 170°C for 2 hours. The solid was then filtered off. The resulting filter cake was washed with 9 L of deionized water at 35°C. The washed cake was dried at 100°C for 24 hours and then ground to obtain a granular solid product. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1.

[0056] Comparative Example 3 1074g of magnesium hydroxide and 359.0g of aluminum hydroxide were placed in a 5L container, and then water was added until the total volume was 3L. After adding 9.0g of acetic acid (reagent), the mixture was stirred for 10 minutes to prepare a slurry. This slurry was supplied to a wet grinding apparatus (DinoMill MULTILAB, manufactured by Shinmaru Enterprises, Ltd., filled with titania beads) and wet-ground for 28 minutes (residence time). The slurry was then removed from the wet grinding apparatus. 1L of the ground slurry was mixed with sodium carbonate in an amount equivalent to 1 / 2 mole per mole of magnesium hydroxide, and the total volume was adjusted with water to 8L. The mixture was then stirred for 10 minutes. 3L of the slurry was transferred to an autoclave and hydrothermally treated at 170°C for 2 hours. The solid was then filtered off. The resulting filter cake was washed with 9L of deionized water at 35°C. The washed cake was dried at 100°C for 24 hours and then ground to obtain a granular solid product. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1.

[0057] Comparative Example 4 A mixed aqueous solution of metal salts was prepared by mixing 96.6 g of zinc sulfate heptahydrate with 81.2 mL of 354 g / L aluminum sulfate aqueous solution (28.7 g as Al2(SO4)3) and adding deionized water to a total volume of 350 mL. Separately, an alkaline mixed aqueous solution was prepared by mixing 46.7 mL of 720 g / L sodium hydroxide aqueous solution with 26.7 g of sodium carbonate and adding deionized water to a total volume of 350 mL. 50 mL of deionized water was placed in a 1 L round-bottom flask, and these aqueous solutions were added under stirring. The pH of the slurry at this time was 9. The slurry was then prepared by stirring at 50°C for 10 minutes. The obtained slurry was filtered and washed with water until the electrical conductivity of the washings was 100 μS / cm or less. Water was added to the obtained cake and stirred to produce a slurry of 110 g / L as a dry powder. This slurry was then dried using a spray dryer (atomizer type, manufactured by Okawara Chemical Machinery Co., Ltd., BDP-22 model) at a disk rotation speed of 16,000 rpm and an outlet drying temperature of 105°C to obtain a plate-like solid product. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1.

[0058] Comparative Example 5 One g of the powder obtained in Comparative Example 4 was placed in a glass petri dish with an inner diameter of 27 mm and a height of 15 mm, and placed in a constant temperature and humidity chamber (ESPEC Corporation, LH-113). The chamber was adjusted from room temperature to 85°C and relative humidity of 85% RH over 15 minutes, and then maintained at 85°C and 85% RH for 166 hours. After that, the power to the heater was turned off and the mixture was cooled to room temperature. This process was carried out in the atmosphere. In this way, a plate-like solid product was obtained. Various measurements were performed on the obtained product as described in Table 1. The results are shown in Table 1.

[0059] [Table 1]

[0060] As shown in Table 1, the hydrotalcite of Examples 1 and 2, which contains magnesium and aluminum elements, has an average major axis of the primary particle surface diameter of 400-700 nm, and an aspect ratio (average major axis of the primary particle surface diameter / average minor axis of the primary particle surface diameter) of 1.4-2.0, showed superior chloride ion scavenging ability compared to the hydrotalcite of Comparative Examples 1-3, which did not meet the requirements for the average major axis of the primary particle surface diameter or aspect ratio, and the hydrotalcite of Comparative Examples 4 and 5, which did not contain magnesium. These results confirm that the hydrotalcite of the present invention is suitable for electronic material applications where a reduction in the anion concentration in the resin is required.

Claims

1. Hydrotalcite containing magnesium and aluminum, The hydrotalcite is particulate, and the primary particles have a plate-like shape. The primary particles have an average plate diameter with a major axis of 400 to 700 nm and an aspect ratio (average plate diameter major axis / average plate diameter minor axis) of 1.4 to 2.

0. Hydrotalcite for electronic materials characterized by the following features.

2. The hydrotalcite is given by the following formula (1): MM １－ｘ Al ｘ (OH) ２ (CO ３ ) ｘ／２ ・.H ２ O (1) The hydrotalcite for electronic materials according to claim 1, characterized in that it is expressed as follows: (wherein x is a number between 0.26 and 0.40, and n is a number between 0.10 and 0.10).

3. Hydrotalcite for electronic materials according to claim 1, characterized in that at least a portion of its surface is coated with a compound having silicon atoms and / or fatty acid groups.

4. A resin composition for electronic materials characterized by comprising hydrotalcite and a resin component as described in any one of claims 1 to 3.

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