KR101790073B1 - Surface-modified crystalline metal oxide and hybrid material and method for preparing the same - Google Patents

Abstract

The present invention relates to a surface-modified crystalline metal oxide capable of improving the energy efficiency as a heat-dissipating and insulating material by forming an oxynitride or aluminum nitride on the surface by modifying the surface of the crystalline metal oxide by using ammonia gas, And a method for producing a hybrid material.

Description

TECHNICAL FIELD [0001] The present invention relates to a surface-modified crystalline metal oxide, a hybrid material containing the same, and a method for producing a hybrid material. BACKGROUND OF THE INVENTION [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-modified crystalline metal oxide, a hybrid material containing the same, and a method for producing a hybrid material. More particularly, the present invention relates to a surface- A crystalline metal oxide and a hybrid material containing the same, and a method for producing a hybrid material.

In general, silica represented by an amorphous oxide in an inorganic material has a Si-OH functional group on the surface thereof and has a hydrophilic surface property, so that the hydrophilic nature of the water-based or alcohol-based silica is easily dispersed. However, in the polymer matrix for organic-inorganic hybridization, there may be a problem in dispersion due to the hydrophilic property of the inorganic material, and it is used through surface modification to improve miscibility with the organic matrix polymer matrix. However, in the case of the crystalline metal oxide (MeO x), it is known that the Me-OH functional group is hardly modified on the surface.

The surface modification methods of inorganic materials, especially metal oxides, can be broadly classified into chemical surface modification and physical surface modification. Organic alkoxysilane coupling agent is mainly used for chemical surface modification, and it has an advantage of enhancing compatibility with an organic material due to strong covalent bond on the inorganic material surface and terminal functional group depending on the type of silane. Physical surface modification involves the improvement of the physical properties of organic / inorganic hybrid materials after hybridization by physical modification of the polymer matrix with physical interaction with steric acid, physical blending, and electrical interactions by amine surfactants .

In addition to basic properties of each material, organic / inorganic composites hybridize with each other in order to complement the disadvantages and to maximize the advantages and give synergy. One of the important things in hybridization is to control the surface polarity of different materials, and the dispersibility between the components is essential. To this end, research has been actively carried out to chemically or electrochemically treat the surface of the substrate, or to treat the surface with a coating and a coupling agent, followed by hybridization.

The coating material containing an organic-inorganic hybrid material contains alumina or silica as an inorganic material having excellent insulating properties with an organic varnish coating agent for improving insulation characteristics of a copper wire in a motor coil. In order to improve the physical properties such as insulation properties of electric / electronic hybrid coatings, electrical withstanding voltage characteristics, adhesion between copper and varnish coating agent and bending strength of coating film, a technique capable of enhancing compatibility of organic and inorganic materials is required .

Korean Patent No. 10-1104390 Korean Patent No. 10-0947891

An object of the present invention is to provide a surface-modified crystalline metal oxide by treating the surface of the crystalline metal oxide with an ammonia gas.

The present invention also aims to provide a hybrid material comprising a surface-modified crystalline metal oxide and a resin.

It is another object of the present invention to provide a method for producing a hybrid material comprising a surface-modified crystalline metal oxide and a resin.

It is another object of the present invention to provide an organic / inorganic hybrid coating material comprising a hybrid material comprising a surface-modified crystalline metal oxide and a resin.

It is still another object of the present invention to provide an organic / inorganic hybrid film comprising a hybrid material comprising a surface-modified crystalline metal oxide and a resin.

In order to achieve the above object, the surface-modified crystalline metal oxide according to the present invention can be surface-modified by treating the surface of the crystalline metal oxide with ammonia gas.

The crystalline metal oxide may include at least one of alumina, zirconia, titania, ceria, manganese oxide, BaTiO ₃ , zinc oxide, iron oxide, and Y ₂ O ₃ except silica which is an amorphous structure.

The crystalline metal oxide may have a particle size of 10 to 2000 nm and a specific surface area of 1 to 150 m < 2 > / g.

The treatment with the ammonia gas may be performed at a flow rate of ammonia gas of 0.01 to 20 L / min.

The hybrid material according to the present invention may comprise a surface-modified crystalline metal oxide and a resin.

The resin may be at least one resin selected from polyamideimide, polyesterimide and polyamic acid.

The method for producing a hybrid material according to the present invention may comprise the following steps:

Treating the crystalline metal oxide with an ammonia gas to modify the surface;

Dispersing the surface-modified crystalline metal oxide in an aqueous or alcohol-based solvent to prepare a metal oxide dispersed sol; And

Adding an organic solvent to the metal oxide dispersion sol, and then adding a resin to hybridize the metal oxide and the resin.

The step of modifying the surface may comprise treating the crystalline metal oxide with ammonia gas at 400 to 900 占 폚 for 1 to 10 hours.

In the step of modifying the surface, the flow rate of the ammonia gas may be adjusted to 0.01 to 20 L / min.

The step of preparing the surface-modified crystalline metal oxide dispersion sol may include mixing the surface-modified crystalline metal oxide and the water-based or alcohol-based solvent at a weight ratio of 1:10 to 1:30.

In the hybridization step, the organic solvent may be at least one solvent selected from the group consisting of n-methylpyrrolidone, dimethylformamide, dimethylacetamide, cellulosic solvents, glycol solvents and ketone solvents.

In the hybridization step, the resin may be at least one resin selected from a polyamideimide, a polyesterimide, and a polyamic acid.

In the hybridization step, the surface-modified crystalline metal oxide may be included in an amount of 1 to 50 parts by weight based on 100 parts by weight of the resin.

The organic-inorganic hybrid coating agent according to the present invention may include a hybrid material including a surface-modified crystalline metal oxide and a resin.

The organic-inorganic hybrid film according to the present invention may include a hybrid material including a surface-modified crystalline metal oxide and a resin.

The surface-modified crystalline metal oxide according to the present invention improves the wetting with the heat resistant resin by modifying the surface of the crystalline metal oxide particle with the surface modifier and simultaneously reduces the -OH group present on the surface of the metal oxide, And AlON or AlN formed on the surface has an advantage of improving the thermal conductivity.

Further, the hybrid material including the surface-modified crystalline metal oxide and the resin is used as a coating material or a film material to improve the insulation property, electrical withstand voltage characteristic, adhesion property between organic and inorganic materials, and bending strength of the coating film There are advantages to be able to.

1 is an XRD graph of the delta alumina particles of Production Example 1 of the present invention and the surface modified alumina particles of Production Examples 2 to 4.
Fig. 2 is an XPS graph of the delta alumina particles of Production Example 1 of the present invention and the surface modified alumina particles of Production Examples 2 to 4; Fig.
3 is a graph showing the contact angles of powder of alumina particles of Production Example 1 and Production Example 4 of the present invention.
4 is an optical microscope photograph of a hybrid film coated on a copper substrate of Comparative Example 1 and Example 1 of the present invention, after bending the hybrid film.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to achieve them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. It is intended that the scope of the invention be defined by the claims and the equivalents thereof.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, a surface-modified crystalline metal oxide, a hybrid material containing the same, and a method for producing a hybrid material according to the present invention will be described in detail.

The surface-modified crystalline metal oxide according to the present invention can be surface-modified by treating the surface of the crystalline metal oxide with ammonia gas.

The crystalline metal oxide may include at least one of alumina, zirconia, titania, ceria, manganese oxide, BaTiO ₃ , zinc oxide, iron oxide, and Y ₂ O ₃ except silica which is an amorphous structure.

The crystalline metal oxide may have a particle size of 10 to 2000 nm and a specific surface area of 1 to 150 m 2 / g. When the content of the crystalline metal oxide is out of this range, .

The treatment with the ammonia gas can be carried out at a flow rate of ammonia gas of 0.01 to 20 L / min. If the flow rate of the ammonia gas is less than 0.01 L / min, sufficient surface modification is not properly performed and the withstand voltage characteristic and the thermal conductivity And when it exceeds 20 L / min, scattering of particles occurs during surface treatment, powder loss occurs, and the surface modification diffuses into the inside of the particles, so that AlON or AlN is excessively formed to cause agglomeration between particles , Which makes it difficult to disperse the crystalline oxide particles, which may deteriorate the insulating properties of the organic / inorganic hybrid coating or film.

The surface-modified crystalline metal oxide may be subjected to surface modification of the crystalline metal oxide by using a gas including nitrogen and hydrogen (for example, N ₂ -H ₂ mixed gas) in addition to the ammonia gas.

The hybrid material according to the present invention may include a surface-modified crystalline metal oxide and a resin. The surface-modified crystalline metal oxide according to the present invention may be dispersed to prepare a surface-modified crystalline metal oxide dispersion sol, Heat-resistant resin or a mixed resin thereof to prepare an organic-inorganic hybrid material having storage stability and coating property.

The resin may be at least one resin selected from the group consisting of polyamideimide, polyesterimide, and polyamic acid, and the resin may have a broad molecular weight distribution by mixing polyamideimides having an average molecular weight in the range of 19,000 to 92,000 , The flexibility, tensile strength, abrasion resistance and the like of the hybrid material can be further improved by blending the polyamideimide and the polyester imide (or polyamic acid).

A method of producing a hybrid material according to the present invention comprises:

Treating the crystalline metal oxide with an ammonia gas to modify the surface;

Dispersing the surface-modified crystalline metal oxide in an aqueous or alcohol-based solvent to prepare a metal oxide dispersed sol; And

Adding an organic solvent to the metal oxide dispersion sol, and then adding a resin to hybridize the metal oxide and the resin.

The step of modifying the surface may include treating the crystalline metal oxide with ammonia gas at 400 to 900 占 폚 for 1 to 10 hours. If the surface of the crystalline metal oxide is out of the range, sufficient surface modification is not achieved, or AlN formation , It is difficult to form dispersed sol, and the crystalline metal oxide is not uniformly present in the formation of the hybrid film, so that the coating surface is broken at the time of bending, and the withstand voltage and thermal conductivity decrease, which is not preferable.

In the step of modifying the surface, the flow rate of the ammonia gas may be adjusted to 0.01 to 20 L / min. When the surface is modified, the surface can not be adequately reformed at a rate of less than 0.01 L / min to improve the withstand voltage characteristics and thermal conductivity. If it exceeds 20 L / min, scattering of the particles occurs during the surface treatment and powder loss occurs. Also, the surface modification diffuses into the inside of the particles, and AlON or AlN is excessively formed so that aggregation occurs between the particles, As a result, it is difficult to disperse the crystalline oxide particles and the insulating properties of the organic / inorganic hybrid coating or film may be deteriorated.

In the step of modifying the surface, the surface-modified crystalline metal oxide may be crystallized by using a gas containing nitrogen and hydrogen (for example, N ₂ -H ₂ mixed gas) in addition to the ammonia gas, Surface modification may be possible.

The step of preparing the surface-modified crystalline metal oxide dispersion sol is a step of adding an aqueous or alcoholic solvent to the crystalline metal oxide and then milling the crystalline metal oxide to prepare a crystalline metal oxide dispersion sol.

The milling may be performed using a nano mill, a nano-dispersed mill, a bead mill, a ball mill, a kneader, a planetary mixer, and an ultrasonic disperser, but there is no particular limitation.

The crystalline metal oxide and the aqueous or alcoholic solvent may be mixed in a weight ratio of 1:10 to 1:30. When the weight ratio is less than 1:10, the concentration of the crystalline metal oxide to be dispersed is high, which is difficult to disperse. When the weight ratio is more than 1:30, the concentration is low and the economical efficiency is low.

The alcohol solvent is not particularly limited, but preferably includes at least one of methanol, ethanol, propanol, and isopropanol.

In the step of hybridizing the metal oxide with the resin, the organic solvent added to the metal oxide sol may be an organic solvent having compatibility with the resin, such as n-methylpyrrolidone, dimethylformamide, dimethylacetamide, But is not limited to, one or more solvents selected from solvents, glycol solvents, and ketone solvents.

In the hybridization step, the resin is a resin having excellent properties in terms of heat resistance, abrasion resistance and low dielectric constant, and specific examples thereof may be at least one resin selected from polyamideimide, polyesterimide and polyamic acid.

In the hybridization step, the surface-modified crystalline metal oxide is preferably included in an amount of 1 to 50 parts by weight based on 100 parts by weight of the resin. When the amount of the metal oxide is less than 1 part by weight, It is not preferable because it is difficult to realize excellent thermal conductivity characteristics. If it exceeds 50 parts by weight, it is difficult to produce dispersion sol, and insulation characteristics as an organic / inorganic hybrid material are lowered.

The organic-inorganic hybrid coating agent according to the present invention may include a hybrid material comprising the surface-modified metal oxide and the resin of the present invention.

The organic-inorganic hybrid film according to the present invention may comprise a hybrid material comprising the surface-modified metal oxide and the resin of the present invention.

Hereinafter, the present invention will be described in detail with reference to the following examples, which should not be construed as limiting the scope of protection defined by the appended claims.

Manufacturing example  One

Delta alumina (particle size: 40 to 50 nm, manufactured by Alfa Aesar, specific surface area: 32 to 40 m 2 / g) was prepared, and the particles were measured by XRD and XPS. The results are shown in FIGS. 1 and 2.

Manufacturing example  2: Surface modified  Delta alumina

Amorphous alumina (manufactured by Alfa Aesar, particle size 40 to 50 nm, specific surface area 32 to 40 m 2 / g) was injected at 400 ° C. with ammonia gas at a flow rate of 1 L / min for 5 hours, The particles of the surface-modified delta alumina thus obtained were measured by XRD and XPS, and the results are shown in FIGS. 1 and 2. FIG.

Manufacturing example  3: Surface modified  Delta alumina

Delta alumina (manufactured by Alfa Aesar, particle size 40 to 50 nm, specific surface area 32 to 40 m 2 / g) was injected at 600 ° C. with ammonia gas at a flow rate of 1 L / min and heat treated for 5 hours to synthesize the surface modified alumina The particles of the surface-modified delta alumina thus obtained were measured by XRD and XPS, and the results are shown in FIGS. 1 and 2. FIG.

Manufacturing example  4: Surface modified  Delta alumina

Delta alumina (manufactured by Alfa Aesar, particle size 40 to 50 nm, specific surface area 32 to 40 m 2 / g) was injected at 900 ° C. with ammonia gas at a flow rate of 1 L / min and heat treated for 5 hours to synthesize the surface modified alumina The particles of the surface-modified delta alumina thus obtained were measured by XRD and XPS, and the results are shown in FIGS. 1 and 2. FIG.

Comparative Example  One

200 g of anhydrous ethanol was added to 10 g of the delta alumina of Preparation Example 1, and the surface modified alumina dispersion sol was milled after the milling using the nano mill. The alumina dispersed sol was added with 315 ml of n-methyl pyrrolidone as an organic solvent, and the mixture was stirred for 5 minutes, and the organic solvent was replaced with water by distillation under reduced pressure. Then, 30 parts by weight of a surface-modified delta alumina dispersed sol was mixed with 100 parts by weight of polyamideimide and stirred to obtain a sol solution in which a surface-modified delta alumina dispersion sol and a polyamideimide were hybridized. For the evaluation of the characteristics, the hybrid solution was coated on the surface of the copper plate coated with the copper wire to the thickness described in Table 1 below, and cured through three steps of 90 ° C for 1 hour, 150 ° C for 15 minutes and 220 ° C for 5 minutes, The withstand voltage of the film is shown in Table 1, and the thermal conductivity is shown in Table 2.

Example  One

200 g of anhydrous ethanol was added to 10 g of the surface-modified delta alumina obtained in Preparation Example 4, and a surface-modified delta alumina dispersion sol was prepared after milling using a nanomill. The alumina dispersed sol was added with 315 ml of n-methyl pyrrolidone as an organic solvent, and the mixture was stirred for 5 minutes, and the organic solvent was replaced with water by distillation under reduced pressure. Then, 30 parts by weight of a surface-modified delta alumina dispersed sol was mixed with 100 parts by weight of polyamideimide and stirred to obtain a sol solution in which a surface-modified delta alumina dispersion sol and a polyamideimide were hybridized. For the evaluation of the properties, the hybrid solution was coated on the surface of the copper plate coated with copper wire to the thickness shown in Table 1 and cured. The curing conditions were three steps of 90 ° C. for 1 hour, 150 ° C. for 15 minutes and 220 ° C. for 5 minutes. The results of the withstand voltage are shown in Table 1, and the results of thermal conductivity are shown in Table 2.

Coating thickness Withstand voltage ^{1 )} primer Primary Secondary kV kV / 10 μm Comparative Example 1 9 탆 16 탆 25 m 8.45 3.38 Mu m Example 1 8 탆 17 탆 23 탆 9.25 4.02

Density (g / cm3) Specific heat (J / g · k) Thermal diffusivity (mm 2 / s) Thermal conductivity (W / mk) ^{2 )} Comparative Example 1 1.287 1.616 0.152 0.316 Example 1 1.353 1.915 0.227 0.588

Note) 1) It is measured by TOS 5101 (KIKUSUI) withstand voltage measurement method by the step method specified in ASTM D 149, and the withstand voltage increases proportionally with thickness, so it is divided by thickness.

2) Thermal conductivity was measured by laser flash method using LFA427 (Netzsch). Samples for thermal conductivity measurement were prepared in the form of pellets having a diameter of 12.6 mm and a thickness of about 1 mm. According to ASTM E1461, Obtain the thermal conductivity by measuring the vertical thermal diffusivity in the thickness direction of the sample.

As shown in Tables 1 and 2, the withstand voltage and the thermal conductivity of Example 1 are superior to those of Comparative Example 1, and as shown in Figs. 1 and 2, Modified aluminum delta alumina shows an oxynitride or aluminum nitride peak, thereby increasing the wetting with the polyamideimide and reducing the hydroxyl groups present on the alumina surface to improve the withstand voltage characteristics, It can be seen that oxynitride or aluminum nitride having an excellent thermal conductivity is formed and the thermal conductivity property is improved.

Claims (15)

A surface-modified crystalline metal oxide obtained by treating a surface of a crystalline metal oxide having a particle size of 10 to 2000 nm and a specific surface area of 1 to 150 m 2 / g with ammonia gas at 400 to 900 ° C for 1 to 10 hours. The method according to claim 1,
The crystalline metal oxide is non-crystalline structure, except for the silica-alumina, zirconia, titania, ceria, manganese oxide, BaTiO _3, zinc oxide, iron oxide, and Y ₂ O ₃ of the surface-modified crystal comprising at least one metallic oxide. delete The method according to claim 1,
And the flow rate of the ammonia gas is set to 0.01 to 20 L / min. A hybrid material comprising a surface-modified crystalline metal oxide and a resin according to any one of claims 1, 2, 6. The method of claim 5,
Wherein the resin is at least one resin selected from polyamideimide, polyesterimide and polyamic acid. A method of making a hybrid material comprising the steps of:
Treating the crystalline metal oxide having a particle size of 10 to 2000 nm and a specific surface area of 1 to 150 m2 / g with ammonia gas at 400 to 900 占 폚 for 1 to 10 hours to modify the surface;
Dispersing the surface-modified crystalline metal oxide in an aqueous or alcohol-based solvent to prepare a metal oxide dispersed sol; And
Adding an organic solvent to the metal oxide dispersion sol, and then adding a resin to hybridize the metal oxide and the resin. delete 8. The method of claim 7,
Wherein the flow rate of the ammonia gas in the step of modifying the surface is 0.01 to 20 L / min. 8. The method of claim 7,
The step of preparing the surface-modified crystalline metal oxide dispersed sol includes a step of mixing the surface-modified crystalline metal oxide and the aqueous or alcoholic solvent at a weight ratio of 1:10 to 1:30 . 8. The method of claim 7,
In the hybridization step, the organic solvent may be at least one solvent selected from the group consisting of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, cellulosic solvent, glycol solvents and ketone solvents. Gt; 8. The method of claim 7,
Wherein in the hybridization step, the resin is at least one resin selected from a polyamideimide, a polyesterimide, and a polyamic acid. 8. The method of claim 7,
In the hybridization step, the surface-modified crystalline metal oxide is contained in an amount of 1 to 50 parts by weight based on 100 parts by weight of the resin. An organic / inorganic hybrid coating material comprising the hybrid material according to claim 5. An organic / inorganic hybrid film comprising the hybrid material according to claim 5.

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