KR101163620B1 - Hollow composites with improved light diffusion, process of the composite, light diffusion agent containing the composite and application thereof - Google Patents

Abstract

PURPOSE: A hollow composite, a method for manufacturing the same, a photo diffusing agent containing the same, and the application of the same are provided to improve hydrophobic surface modifying effect and to eliminate interference fringe phenomenon. CONSTITUTION: A hollow composite includes silica and magnesium fluorine doped to the silica. The hollow composite is represented by chemical formula, (MgF_2)_a(SiO_2)_1-a. In chemical formula, a is the weight ratio of the magnesium fluoride doped to the silica and is between 0.005 and 0.25. The average diameter of the hollow composite is between 100nm and 10.0um. The average thickness of the hollow composite is between 30nm and 1000nm. The average aspect ratio of the hollow composite is between 1.2 and 10.

Description

Hollow Composites with Improved Light Diffusion, Process of the Composite, Light Diffusion Agent Containing the Composite and Application Thereof}

The present invention relates to a composite particle of a hollow structure, and more particularly to a composite particle having a hollow plate-like form with good light diffusion efficiency, a method of manufacturing and application thereof.

With the rapid development of display technology, the development of various types of lighting devices instead of the existing lighting devices is also rapidly progressing. For example, various light-diffusion materials are used for the purpose of uniformly diffusing light projected from a point light source such as a light emitting device (LED) for advertisement or lighting, or a line light source such as a cold cathode tube or a fluorescent tube to obtain a good surface light source with good luminance. Is being developed. Typically in such lighting devices, light diffusion comprising an appropriate amount of organic or inorganic particles in a binder resin on top of the substrate, so that illumination by a point light source can be converted into linear or planar, uniform line- or plane-lights. It is common for a light-diffusion structure in the form of a light-diffusion film or a light-diffusion sheet adopting a material to be laminated.

For example, a light diffusing film or sheet of a light guide plate or a light diffusion plate of a display of a mobile phone, a digital camera or the like employing a liquid crystal display device (LCD) or a backlight unit of an LCD monitor or an LCD TV; Liquid crystal projector screen; Light diffusion plates of LEDs for home or facility lighting or advertising; The light-diffusion structure of the form of a light-diffusion film and a light-diffusion sheet etc. can be mentioned in the back panel of a plasma display panel (PDP). However, basically, the light diffusing material used in various lighting devices should have high light diffusivity to enable uniform surface light emission, and should not only maintain high brightness by concentrating the light emitted from the light source, but also high in terms of power consumption reduction. Permeability is required at the same time.

In this case, as a method for satisfying the light-diffusion and light-transmittance required in the light-diffusion structure, a matrix resin (binder) of a transparent thermoplastic material having good light transmittance, such as polycarbonate or polyester, is molded into a sheet form By embossing such as stamping, etching or sand blasting on the surface of the sheet of the binder resin to form fine unevenness on the surface of the sheet, the refraction and scattering of light due to fine unevenness are achieved. It is common to impart light-diffusion to a method of obtaining a uniform surface light source through and including organic or inorganic particles having light diffusing properties such as silica, acrylic or polystyrene as a light diffusing agent, for example, in the binder resin. As a method of uniformly dispersing the light diffusing agent in the binder resin, the above-described light diffusing agent is molded into beads and physically dispersed using a disperser such as a bead mill or roll milling machine or by adding a monomolecular or low molecular weight dispersant. A method of chemically dispersing the light diffusing agent in the binder resin is used.

Many attempts have been made with respect to light diffusing members or light diffusing bodies employing such light diffusing materials. For example, Korean Patent Publication No. 10-2008-0042882 proposes a light-diffusion film having a light-diffusion material therein and having a surface irregularities in which the maximum / minimum value (anisotropy) of the average aspect ratio of the base film is 1.1 or more. In Korea Patent No. 10-1051029, the organic light diffusing agent such as silicone resin, polyacrylate, polyurethane, polyethylene, etc. containing a thermoplastic transparent matrix resin of 95% or more and having a constant particle size distribution or silica, alumina, etc. The light-diffusion member of the sheet | seat or film form which consists of a base material containing the inorganic type light diffusing agent of which fine unevenness | corrugation is formed in the surface is demonstrated. However, since it is difficult to form fine unevenness required by these patents and must use three kinds of light diffusing agents having different particle diameters, it is not a preferable choice from an economic point of view.

On the other hand, Korean Patent Publication No. 10-2010-0063668 is a conventional light diffusing material in the form of silicon particles of the spherical shape is a method for solving problems such as low light diffusion, insufficient light condensing ability, brightness unevenness, aluminum salt hydroxide As a light diffusion structure having a light diffusion layer having excellent acid resistance and organic solvent resistance, which is composed of an inorganic particle and a resin having a goggle shape, a cylindrical plate shape, or a hexagonal plate shape, are proposed. However, there is a problem that controlling the specific shape of the inorganic particles is not easy.

In addition, Korean Patent Laid-Open Publication No. 10-2010-0130811 proposes a light diffusion film having a light diffusion layer modified with a polymer in an aerogel of a metal oxide containing silica in all or part of at least one surface of the base film. However, aerogels are relatively expensive, and if the polymer penetrates into pores formed in the aerogel, the desired light diffusion effect cannot be achieved. Therefore, the molecular weight or polymer content of the polymer should be adjusted. Korean Patent Publication No. 10-2011-0108146 discloses a porous or hollow light diffusing agent filled with air or nitrogen, and a polymer having a material similar to that of a base resin such as polymethyl methacrylate or polysilicon as a light diffusing agent. By using the light diffusing plate to prevent the Egg Mura phenomenon in which the difference in brightness appears in the center part of the display which adopts the liquid crystal display element excellent in heat insulation characteristic, it is proposed. In addition, Korean Patent Laid-Open Publication No. 10-2008-0063786 discloses a constant irregularities on the surface of a hollow multilayer body or a light guide body composed of a binder resin, or uses a well-known light diffusing agent in a hollow cell of a hollow multilayer body as a light deflection means. A surface light emitting device and a surface light emitting method using the same are proposed.

By the way, the light diffusion particles in the form of resin particles, which are organic materials, have a problem in that the surface of the light diffusion layer is charged and foreign matters are easily adsorbed, and thus the luminance is reduced in the process of removing the foreign matters using an organic solvent. In addition, some organic light-diffusing particles are not sufficiently dispersed in the binder even if a dispersant is used, and their durability decreases with time. On the other hand, silica fine particles as inorganic particles cause problems such as scratches on the diffusion surface during processing fixation. In addition, in general, the light-diffusion sheet in the form of a hollow bead is not only poor workability, but also increases the light diffusion as the content increases, but there is a problem inferior in light transmittance. In particular, in order to obtain a uniform high-luminance, the size of these light diffusing agents must be controlled to a certain range, which was not easy. Therefore, it is urgent to develop a light diffusing agent which can solve both the above problems and satisfy both good light-diffusion, light-transmittance and high-brightness at the same time, and can satisfy all of the stability in the processing process. .

An object of the present invention is to provide hollow composite particles having a plate-like structure not only excellent in scratch resistance, but also having increased light diffusion efficiency.

Another object of the present invention is to provide a hollow composite particle having excellent light diffusion efficiency without interference fringe phenomenon called Moire phenomenon.

Another object of the present invention is to provide a hollow composite particle having a high total light transmittance and light diffusivity (Haze) while alleviating the problem of glare and brightness unevenness.

It is another object of the present invention to provide hollow composite particles in a light diffusion plate requiring a heat insulating property of a substrate and a backlight unit assembly and an illumination field using the same.

Other objects and advantages of the present invention will become more apparent from the following description and drawings describing preferred embodiments.

In the present invention, it was found that when the hollow composite particles are used, a light diffusing agent having high total light transmittance and excellent light diffusing property can be produced. In particular, the present invention is to form a composite hollow shell of magnesium fluoride and silica having a low refractive index and to produce hollow composite particles having a spherical and plate-like shape, and thus, preferably a total light transmittance and a light diffusing property as a light diffusing agent (Haze It relates to a method for producing a plate-shaped hollow composite hollow particles excellent.

In particular, doping hollow silica using magnesium fluoride having a low refractive index on its surface and preparing hollow composite particles having a plate-like, oval or convex lens shape, thereby providing a plate-like type having excellent total light transmittance as a light diffusing agent and haze. It relates to a method for producing hollow composite hollow particles.

That is, the present invention provides a hollow composite represented by the following general formula (1) as a hollow composite in which amorphous silica (SiO ₂ ) and magnesium fluoride are blended, preferably a magnesium-fluoride doped silica.

Formula 1

(MgF ₂ ) _(a) (SiO ₂ ) _(1-a)

(In Formula 1, a is a weight ratio of magnesium fluoride doped to silica and ranges from a = 0.005 to 0.25)

In this case, the hollow composite is not completely spherical, it is preferable to have a plate-like, elliptical or convex lens shape to enhance the light diffusion effect. In particular, the hollow composite prepared according to the present invention

In this case, the hollow composite according to the present invention has an average particle diameter of 100 nm to 10 μm, preferably an average particle diameter of 150 nm to 1.0 μm, and the average thickness of the hollow composite is 30 to 1000 nm, average The aspect ratio (long diameter / thickness) may range from 1.2 to 10. Moreover, it is especially preferable that the thickness of the shell which comprises a hollow composite_body | complex is 5-100 nm.

On the other hand, according to another aspect of the present invention, a method for producing a hollow composite as described above, comprising the steps of preparing a composite sol of silica doped with magnesium fluoride; Reacting the composite sol of silica-doped silica with inorganic particles to form a core-shell structured particle composed of a shell of magnesium-fluoride-doped silica and an inorganic core; It provides a method for producing a hollow composite comprising the step of removing the inorganic core from the particles of the core-shell structure obtained to form a hollow composite of magnesium fluoride-doped silica.

Preferably, the method may further include surface treatment using a fatty acid, a fluorine-based organic compound, or various silane coupling agents on the surface of the hollow silica-magnesium fluoride formed.

At this time, the inorganic particles used as the core is characterized in that the hydrotalcite represented by the formula (2).

Formula 2

M ²⁺ _1-x M ³⁺ _x (OH) ₂ (A ^n- ) _{x / n} ? MH ₂ O

In Formula 2, M ²⁺ and M ³⁺ are mixed metal components forming the center of the positive charge layer, respectively, M ²⁺ is Mg ²⁺ , Ca ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Mn ^Is a metal component which may have an oxidation number of +2 selected from the group consisting of ²⁺ and Zn ²⁺ , and M ³⁺ is selected from the group consisting of Al ³⁺ , Fe ³⁺ , Ga ³⁺ and Y ³⁺ (OH) is a component constituting the upper and lower sides of the mixed metal component, and A ^n- is an interlayer anion having a valence of n and can be exchanged with other anions. as the _{^{anions, CO 3 2-, NO 3-,}} SO 4 2-, OH -, F -, Cl -, Br - and silicon (Si) - anion-containing oxyacids, the (P) - containing anionic oxygen acids, boron ( B) -containing oxygen acid anions, where x is a fraction of the M ²⁺ component and the M ³⁺ component, in the range of 0.20 ≦ x ≦ 0.50 and in the range of 0 ≦ m <1)

In this case, the inorganic particles used as the core may be a partially dehydroxylated hydrotalcite of Formula 3 or hydrotalcite from which the crystal water of Formula 4 is removed.

Formula 3

M ²⁺ _1-x M ³⁺ _x (OH) _2-y O _y (A ^n- ) _{x / n} ? MH ₂ O

(In Formula 3, M ²⁺ , M ³⁺ , (OH), x and m are the same as defined in Formula 2, and 0 ≦ m <1.)

Formula 4

M ²⁺ _1-x M ³⁺ _x (OH) ₂ (A ^n- ) _{x / n}

(In Formula 4, M ²⁺ , M ³⁺ , (OH), x and A ^n- are the same as defined in Formula 2).

In particular, if necessary, the hydrotalcite used as the core may be heat-treated at a temperature in the range of 500 to 700 ° C., so that hydrotalcite in a form in which an interlayer anion is removed may be used.

Meanwhile, as an example, the hydrotalcite may have a first metal precursor selected from an oxide, a hydroxide, a chloride, or a salt of a metal which may have an oxidation number of +2 in Formula 2, and an oxidation number of +3 in Formula 3 It is obtained by reacting a second metal precursor selected from oxides, hydroxides, chlorides or salts of metals that can be used, and the inorganic or organic acids can be used to remove the inorganic cores. The inorganic core may be removed by treatment with an inorganic or organic acid under conditions.

In particular, the inorganic particles used as the inorganic core may be soluble in the range of pH 0.5 to 3.0 and may be an inorganic material in the form of a plate, a sphere and an ellipse. Inorganic particles usable in connection with the present invention include, in addition to the hydrotalcites described above, metal hydroxides, metal oxides or metal carbonates. Examples of the metal hydroxide include aluminum hydroxide, apatite hydroxide, magnesium hydroxide and calcium hydroxide, and the metal oxide may be etched by a strong acid, and may be selected from the group consisting of zinc oxide (ZnO), iron oxide and zeolite. Moreover, calcium carbonate, magnesium carbonate, hydromagnesite etc. are mentioned as a metal carbonate.

In addition, the present invention provides a light diffusing agent in which the silica hollow composite doped with the above-described magnesium fluoride is dispersed in, for example, a binder resin. In this case, the hollow composite according to the present invention may be blended and dispersed in an amount of 0.001 to 200 parts by weight, preferably 0.1 to 200 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the resin. The light diffusing agent in which the hollow composite according to the present invention is dispersed in the resin may be in a liquid form, for example, in the form of a solid masterbatch or compound pellet form through an extrusion process after mixing the hollow composite with a binder. It may be solid.

The present invention also provides a light diffusing structure in which the above-described light diffusing agent is mixed with the substrate, or laminated or coated on the substrate. In this case, the light diffusing agent may have the form of a light diffusing composition liquid. In this case, for example, the substrate to which the light diffusing agent may be applied in the form of a composition liquid may be in the form of a sheet or a film, and may be applied to the light diffusing sheet or the light diffusing film.

At this time, the light diffusing structure using the light diffusing agent prepared in the present invention is manufactured by an extrusion or injection process, may have the form of LED (LED) lampshade, bulb or tube, LED (LED) chip or LED (LED) can be used for packaging. For example, the substrate on which the light diffusing agent is laminated may be a substrate which is a light diffusing film or sheet for an organic light emitting diode (OLED).

In addition, the present invention provides a surface light emitting device including the light diffusing agent or light diffusing structure described above. As such a surface light-emitting device, CCFL or LED backlight unit assembly of a liquid crystal display element (LCD), OLED, LED package, or PDP panel is mentioned, for example.

In the prior art, since the spherical silicon particles were used as the light diffusing agent, the total light transmittance was high, but the haze was small, so that the light diffusivity could not be secured.

In the present invention, a hollow composite particle, preferably a plate-shaped, elliptical, convex lens-like hollow composite is introduced to converge the diverging light of point light sources such as light bulbs and LEDs or line tubes such as fluorescent tubes to maintain high brightness To do. At this time, since the refractive index (1.25 to 1.35) of the unique particles having the air layer inside the hollow composite particles is low, when the incident light enters the hollow interior, diffusion occurs again in the hollow interior, Light diffusion occurs several times. This results in high total light transmittance and light diffusivity. In addition, the light source entered into the hollow becomes weakly retroreflective and interference fringes can be eliminated.

By doping magnesium fluoride to silica, which is the main component of the hollow body, it is possible to secure a higher total light transmittance by securing a refractive index lower than that of the silica, and additionally, scratch resistance and hydrophobic surface modification effects can be seen.

1 is a flow chart schematically showing a process for producing a hollow composite according to the present invention.
Figure 2 is an enlarged 30,000 times FE-SEM picture of the hydrotalcite prepared in Example 1 of the present invention used as a core.
3 is a TEM photograph of zinc oxide (ZnO) particles prepared in Example 15 of the present invention and used as a core.
FIG. 4 is a 30,000-fold magnification of a field emission scanning electron microscope (FE-SEM) photograph of a hollow composite shell prepared according to Example 3 of the present invention.
5 is a TEM photograph of a hollow composite shell prepared according to Example 3 of the present invention.
Figure 6 is an enlarged 30,000 times FE-SEM picture of the hollow composite shell prepared according to Example 5 of the present invention.
Figure 7 is a 30,000 times magnification of the FE-SEM picture of the hollow composite shell prepared according to Example 6 of the present invention.
8 is a TEM photograph of a hollow composite shell prepared according to Example 16 of the present invention.
9 is a TEM photograph of a hollow composite shell prepared according to Comparative Example 1 of the present invention.
Figure 10 is a FE-SEM picture of the hollow composite shell prepared according to Comparative Example 3 of the present invention, a magnified 30,000 times.
11 is a TEM photograph of a hollow composite shell prepared according to Comparative Example 3 of the present invention.
12 is a TEM photograph of particles prepared according to Comparative Example 4 of the present invention.
13 is a TEM photograph of particles prepared according to Comparative Example 6 of the present invention.

The inventors have found that the hollow particles have an excellent light diffusing effect, and in particular, metal hydrates, which may be hydrotalcites, to form hollow shapes in the form of plate, oval or lens using a plate-shaped core, By using a metal oxide such as tin oxide as a core, it was possible to form hollow particles in the form of a plate. EMBODIMENT OF THE INVENTION Below, this invention is demonstrated.

1. Hollow composite

The spherical silica, which was mainly used as a light diffusing agent according to the prior art, has a good total light transmittance but has a low haze, and thus can not secure light diffusivity. By scattering or reflecting light strongly, problems such as glare and luminance unevenness have emerged.

Therefore, the hollow composite of the present invention is preferably in the form of a plate, and has a composite form doped with magnesium fluoride on the surface of silica, so that the lack of condensing ability and light scattering and reflection, which were problems of the spherical light diffusing agent, are caused by glare or luminance. The advantage is that there is no nonuniformity. In particular, when the light diffusing agent containing the plate-shaped hollow particles according to the present invention is laminated or coated on the surface of the substrate, the light diffusivity is very good because the difference in refractive index is large compared with other components. In addition, according to the present invention, the interference fringe, called Moire phenomenon, may also solve the problem due to the excellent light collecting ability and the light diffusing performance of the hollow plate-shaped composite silica particles.

In addition, in the present invention, the hollow silica particles, preferably the hollow silica particles are doped with magnesium fluoride, thereby lowering the original low refractive index of the silica and lowering the moisture absorption rate of the moisture, thereby highlighting the function as a light diffusing agent. In particular, a hollow plate-like composite of hollow silica and magnesium fluoride is formed by using magnesium fluoride having low refractive index, corrosion resistance, thermal stability, and high hardness, as well as moisture penetration, and penetration of organic solvent and resin during the manufacturing process. At the same time, the hydrophobic properties of magnesium fluoride are used to modify the surface of the hydrophilic silica particles to be hydrophobic, and composite hollow plate-shaped particles which do not impair the original low refractive properties are prepared and used for the light diffusing agent. The surface of the hollow composite particles may be additionally provided with a silane coupling agent in which fluorine is bonded to a functional group, a fluorine alcohol, or a resin containing fluorine, thereby additionally providing fouling resistance.

That is, the hollow composite according to an aspect of the present invention is a hollow microparticle having a hollow structure, and forms a shell portion in which silica and magnesium fluoride are blended. As used herein, the term "hollow" is understood to mean the interior void space surrounded by the shell-forming inorganic composite (shell portion of the silica and metal fluoride composite), the term "cavity" can be used simultaneously. have. In this sense, the term "composite hollow shell" or "composite hollow body" can be used interchangeably for the hollow composite composed of silica-magnesium fluoride. On the other hand, when using the terms "plate-like composite hollow shell", "plate-like composite hollow body", "plate-like composite hollow body" with respect to the composite hollow body according to the present invention, "plate-like" or "plate-like form", It means a form in which at least one surface, preferably two or more surfaces of the shell portion surrounding the hollow portion of the hollow particles produced has a flat form. Here, the term “flat” may include a shape in which the surface of the shell portion surrounding the hollow portion is completely flat as well as a shape curved inward or outward with a predetermined curvature. Therefore, in the form of a plate, the cross-sectional shape of the particles viewed from the hollow end of the hollow particles manufactured according to the present invention has a square or hexagonal shape while the entire hollow particles are a square column shape, a hexagonal column shape, and a cube shape. And, the cross-sectional appearance of the particles viewed from the end of the hollow portion may include a case having a long oval or convex lens shape. However, it should be noted that in some cases, the plate shape and the oval or convex lens shape may be used separately. Regarding the surface shape of the plate-shaped hollow composite including elliptical and convex lens shapes, the ratio of the length / short axis of the long axis or the length of the length or the length / short side of the long side ( Iii) or the term "aspect ratio (aspect ratio)" is used for the ratio of the length of the thickness.

Hollow composite according to the present invention is a hollow composite particles having a structure of the formula (1) preferably having a plate-like form.

Formula 1

(MgF ₂ ) _(a) (SiO ₂ ) _(1-a)

(In Formula 1, a is a weight ratio of magnesium fluoride doped to silica and ranges from a = 0.005 to 0.25)

That is, in the present invention, better light diffusibility is realized through hollow composite particles having a shell portion in which magnesium fluoride and silica are blended in an appropriate ratio. At this time, if the amount of magnesium fluoride to silica to more than 0.005 molar ratio, it prevents the adsorption or penetration of moisture to the desired degree. In addition, when the amount of the magnesium fluoride doped with respect to silica exceeds 0.25 molar ratio, the shell forming the outer shell of the hollow composite is not formed or the shell is broken. In addition, a shell is not formed in the core, and independent solid particles are generated, which causes the light diffusion property to be inhibited. In particular, the light transmission property is lowered or the haze is lowered to decrease the light diffusion property. In particular, when the molar ratio of magnesium fluoride is 0.8 molar or more, magnesium fluoride is not formed in the shell portion, but rather, magnesium fluoride in the form of 20 to 50 nm is formed, and thus, light diffusion properties of the composite or solid particles without hollow parts are reduced. . In particular, when the molar ratio of magnesium fluoride is greater than 1, the hollow shell is not formed, and as a result, a transparent diffusion film that transmits light without any light diffusing characteristics is obtained, which is not preferable.

Silica and magnesium fluoride constituting the plate-shaped hollow composite according to the present invention can be synthesized from a sol in which each precursor is dispersed in a suitable solvent as described below. Although alkoxy silane is mentioned as a precursor for forming a silica, this invention is not limited to this.

At this time, the hollow composite prepared according to the present invention is a hollow plate-like composite having an average particle diameter (average particle diameter) of 100 nm to 10 μm, preferably a hollow plate-like composite having an average particle diameter of 150 nm to 1.0 μm, and an average aspect ratio. (The aspect ratio is a hollow plate-shaped composite in the range of 1.2 to 10. In this case, when the hollow particles of the present invention are not spherical but have a plate-like shape, for example, the particle diameter is obtained as a 'spherical particle diameter', This means the diameter of a sphere having a volume equal to the volume of the particles.

By adjusting the average particle diameter in the above-mentioned range, it is possible to diffuse light efficiently and improve the luminance uniformity. If the average particle diameter of the hollow plate-shaped hollow composite is smaller than the above-mentioned range or the aspect ratio is lower than the above-mentioned range, the hollow inside the particles is not sufficient, so that the light diffusion performance and the total light transmittance are lowered and it is difficult to exhibit high brightness diffusion performance. . If the average particle diameter exceeds the above-mentioned range, it is difficult to obtain a stable dispersion, the shell is weak due to the characteristics of the plate structure, it is difficult to maintain the particle shape, and the thinly formed shell is likely to generate a large number of broken hollow composite particles, mechanical properties This is because it may be degraded.

The average thickness of the shell portion of the hollow composite according to the invention is preferably in the range of 5 to 100 nm, more preferably in the range of 10 to 50 nm. If the thickness of the shell portion is smaller than this, it is difficult to manufacture because it is difficult to maintain the shape of the particles. If the thickness of the shell portion is larger than this, the ratio of the cavities decreases, so that it is difficult to secure sufficient total light transmittance and light diffusivity. In this case, the hollow plate-like composite according to the present invention may have an average thickness in the range of 30 to 1000 nm.

2. Manufacturing Method

With reference to the accompanying Figure 1 will be described a method for producing a hollow composite according to the present invention.

First, as a precursor of the components constituting the shell portion of the hollow composite of the present invention, a silica (Si) precursor solution, a magnesium (Mg) precursor solution and a fluorine (F) precursor solution are prepared (s110, s120, s130), and the hollow A composite sol of silica and metal fluoride constituting the shell portion of the composite is prepared (s140). The silica sol can be, for example, silica whose surface is preserved in sol form with siloxane groups or silanol groups. Silica sol comprising siloxane groups can be dispersed in water to form colloidal silica. Suitable precursors for forming silica sol include silanes to which functional groups such as alkoxy silanes are attached, tetra-alkyl-ortho-silicate (TAOS), and glass water.

As tetraalkyl orthosilicate (TAOS) which can be used as a silica precursor, tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl ortho And silicates. Among these, TMOS, TEOS or a mixture thereof can be mentioned.

As the alkoxy silane which is a silica precursor that can be used in connection with the present invention, dialkoxysilanes such as dimethyldimethoxysilane, diethyldimethoxysilane, methylethyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, Methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, phenyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-methacryloylpropyltrimethoxysilane, gamma- ( Trialkoxysilanes such as 2-aminoethyl) aminopropyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra (n-propoxy) silane, tetra ( And tetraalkoxy silanes such as isopropoxy) silane. As an alkoxysilane which has a functional group, chlorosilanes, such as tetrachlorosilane and methyl trichlorosilane, are mentioned as silanes which have halogen, for example.

At this time, a hydrogen type strong acid cation exchange resin and an organic solvent are added to the aqueous silica sol, followed by stirring to allow the metal ions contained in the aqueous silica sol to be adsorbed onto the exchange resin, and then the reaction mixture is filtered to remove the exchange resin. A sol in which silica is dispersed in a mixed solvent of water and an organic solvent is obtained.

The metal ion is sodium, aluminum, iron, etc., attached to the surface of the silica and present in the form of Si-O-M +, causing the silica to aggregate when the organic solvent is added. Thus, treatment of the aqueous silica sol with a hydrogen type strongly acidic cation exchange resin not only increases the dispersion stability of the silica sol, but also converts the silica surface to Si-OH, which reacts favorably with the silane coupling agent in a subsequent process. The aqueous silica sol has an average particle diameter of 5 to 150 nm, preferably 8 to 100 nm in consideration of the physical properties and storage stability of the sol. At this time, when the particle diameter is less than 5 nm, the durability of the finally obtained organic-inorganic hybrid nanocomposite is lowered, and on the contrary, when the particle size exceeds 150 nm, dispersibility and storage stability of the sol are lowered.

In addition, in consideration of economical efficiency and stability, the aqueous silica sol has a concentration of 5 to 50%, preferably 20 to 30%. At this time, if the concentration is less than 5%, the amount of the organic solvent substituted with water of the silica aqueous sol in the subsequent process is not economically increased by that amount, and if the concentration exceeds 50%, the viscosity of the aqueous silica sol increases to recover and By increasing the pressure of the filtration membrane, not only the life of the membrane is shortened, but also the stability is lowered.

The aqueous silica sol is a colloidal silica aqueous sol in which silica sol is dispersed in water, and is directly purchased or commercially available. The aqueous silica sol provides a very economical advantage by making sodium ions removed from the water glass. The commercially available aqueous silica sol generally exhibits a basic pH of 9 to 11, in which an additional ion exchange, for example, an ion exchange using a hydrogen type strongly acidic cation exchange resin, is carried out in the step of removing water described below. In this case, it is preferable to use an aqueous silica sol stabilized in an acidic region.

Stirring is performed while an organic solvent is added to the aqueous silica sol, and the content of the organic solvent added is determined according to the concentration of the aqueous silica sol. Preferably, the organic solvent is used in an amount of 0.5 to 200 parts by weight based on 100 parts by weight of water contained in the aqueous silica sol. Thereby, the miscibility in the water of the organic base or silane coupling agent which may be added in the process mentioned later can be increased.

At this time, the hydrogen-type strong acid cation exchange resin, as described above, for removing the metal ions contained in the aqueous silica sol, not limited in the present invention can be used a known one. Typically, the hydrogen-type strong acid cation exchange resin is a sulfonic acid exchanger, the support is used polystyrene and / or divinylbenzene, Diaion SKTM, Zeorex SATM, Dowex 50TM, Amberlite IR-120TM and IR-112TM series Used.

Meanwhile, as the magnesium precursor constituting the metal fluoride used as the structural shell of the hollow composite according to the present invention, a metal compound in the form of a water-soluble organic salt or an inorganic salt may be used. For example, if magnesium is used, one or more magnesium compounds selected from the group consisting of magnesium acetate, magnesium chloride, magnesium bromide, magnesium citrate, magnesium oxalate, magnesium nitrate, magnesium sulfate and their hydrates can be used. Can be.

In addition, as the fluorine precursor, a fluorine compound in the form of a water-soluble fluoride may be used, for example, hydrofluoric acid (HF), sodium fluoride (NaF), potassium fluoride (KF), cesium fluoride (CsF), and ammonium fluoride (NH _4). F), at least one fluorine compound selected from the group consisting of acidic ammonium fluoride (HF-NH ₄ F) and tetra-ammonium fluoride can be used. At this time, in the case of using a magnesium precursor solution as a metal precursor, for example, the magnesium precursor solution and the fluorine precursor solution may each contain an amount such that the molar ratio of magnesium (Mg) to fluorine (F) does not exceed 1: 3. The reaction may be carried out in an amount such that the molar ratio of magnesium (Mg) to fluorine (F) is 1: 1.5 to 1: 2, more preferably 1: 1.9 to 1: 2. Although the thickness of the desired shell portion can be controlled by adjusting the amount of the alkoxy silane, the metal precursor and the fluorine precursor, a person skilled in the art can select appropriately.

In addition, water and / or an organic solvent are used as a dispersion medium with respect to the precursor which exists in a sol state. Preferred dispersion medium is distilled pure water. As organic solvents, polar, nonpolar and aprotic solvents are preferred. Examples include aliphatic alcohols having 1 to 6 carbon atoms, in particular methanol, ethanol and lower alcohols such as n- and I-propanol and butanol; Polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol and triethylene glycol; Ketones such as acetone, methyl ethyl ketone, butanone, and esters such as ethyl acetate; Ethers such as diethyl ether, detrahydrofuran and tetrahydropyran; Amides such as dimethylacetamide and dimethylformamide; Sulfoxides and sulfones such as sulfolane and dimethyl sulfoxide; Aliphatic (optionally halogenated) hydrocarbons such as pentane, hexane and cyclohexane; And mixtures thereof. Preferably it has a boiling point which can be easily removed by distillation, for example, it is preferable that boiling point is 200 degrees C or less, especially 150 degrees C or less.

The silica precursor / metal fluoride precursor which will form a shell part is mixed with a suitable solvent, and binding and hydrolysis reaction of a precursor are performed. The kind of solvent is not particularly limited, and various aqueous and organic solvents known in the art can be used. Preferably a mixed solvent of water and alcohol is used. In such a mixed solvent, water plays a role of conducting a hydrolysis reaction of the added silica precursor. In this step, a hydroxyl group capable of carrying out the condensation and gelation reaction described below is introduced into the silicon atom in the silica precursor.

Silica precursors are usually used in admixture with a suitable organic solvent, such as alcohol, because they do not dissolve well in water. The alcohol may dissolve both water and the silica precursor, and accordingly, the hydrolysis reaction may proceed by homogeneously mixing the water and the silica precursor. At this time, the blending ratio of water and alcohol is not particularly limited, and a person skilled in the art can easily select a suitable blending ratio. The hydrolysis reaction of the silica precursor may be carried out by a general method of stirring under reflux conditions, for example, or by an acidic catalyst (HCl, CH ₃ COOH, etc.) or a basic catalyst (NaOH, KOH, NH _4). A suitable catalyst such as OH) may be used to promote the hydrolysis reaction. For example, caustic soda, ammonium chloride or the like can be used to promote hydrolysis of the silane compound as a silica precursor. At this time, for example, if a mixed solvent of water and alcohol is used as a solvent used for hydrolysis and adjusted in the range of pH 9 to 10, the mixed solvent / silane is used in the range of 2 to 6, preferably in the range of 3.5 to 5 to be.

Subsequently, as a method for forming the hollow composite from the aforementioned precursor complex sol solution, the present invention utilizes inorganic particles in a sol form or a non-sol form as a core (s150). Inorganic particles usable as cores in the context of the present invention include metal hydroxides, metal oxides, and metal carbonates, in addition to hydrotalcite, which will be described later in the form of sol or simple particles. Other materials may also be included.

First, in order to utilize hydrotalcite as a core, hydrotalcite in a sol state dispersed in an appropriate solvent, for example, the above-mentioned solvent, as in the complex sol state of silica and metal fluoride in s110 steps s120 and s130 to s140 steps. Can be formed.

Hydrotalcite (Hydrotalcite) are anionic clays, layered double hydroxides (layered double hydroxide, LDH), the layer as the layer complex hydroxide, also known as mixed metal hydroxide, mixed-metal component and a hydroxyl group (OH ^-) anion between the layer and the layer made of the It means a material having a fixed structure. Specifically, the hydrotalcite has a tetrahedral or trivalent metal cation centered on it, and typically has six octahedron structures in which six hydroxide ions (OH-) surround these metal cations, and the octahedral unit repeats. As a result, it has a double layer structure that forms two layers, and an anion and water molecules are positioned between the double layers to maintain an equilibrium of charge amount, and can be generally represented by the following general formula. Such hydrotalcite may be represented by the following formula (2).

Formula 2

M ²⁺ _1-x M ³⁺ _x (OH) ₂ (A ^n- ) _{x / n} ? MH ₂ O

(In Formula 2, M ²⁺ and M ³⁺ are each a mixed metal component constituting the center of the positive charge layer. For example, M ²⁺ is Mg ²⁺ , Ca ²⁺ , Fe ²⁺ , Co ²⁺ , Ni. A metal component which may have an oxidation number of +2 selected from the group consisting of ²⁺ , Mn ²⁺ and Zn ²⁺ , and M ³⁺ is composed of Al ³⁺ , Fe ³⁺ , Ga ^3+, and Y ³⁺ . (OH) is a component constituting the upper and lower sides of the mixed metal component, and A ^n- is an interlayer anion having a valence of n and the other anion. n is also as anion is exchangeable, for _{^{example, CO 3 2-, NO 3-,}} SO 4 2-, OH -, F -, Cl -, Br -, silicon containing SiO ₃ ^2- (Si ))-Containing oxygen acid anion, phosphorus (P) -containing oxygen acid anion including PO ₄ ^3- , boron (B) -containing oxygen acid anion containing BO ₃ ^2- , consisting of CrO ₄ ^2- , CrO ₇ ^2- Can be selected from the group x is M ²⁺ surname As the fraction of the fraction and the M ³⁺ component, the total charge of the hydrotalcite of this structure is determined according to the fraction value of the M ³⁺ component, which is usually in the range of 0.20 ≦ x ≦ 0.50, preferably 0.20 ≦ x ≦ 0.36, while 0 ≤ m <1)

The addition or mixing of the metal raw material component, the anion source and the alkali component used as the core according to the present invention is not particularly limited, and according to the present invention by adjusting the input amount of the raw material of the aforementioned metal component, hydroxide ion and interlayer anion The content of each metal component can be adjusted, and the mole fraction adjustment of magnesium (Mg), which is a main component of the divalent metal component, and aluminum (Al), which is a trivalent metal component, is well known. That is, the value of x, which is a mole fraction of Al, which is a trivalent metal component in the layered composite metal hydrate in the form of hydrotalcite particles represented by Formula 2, is usually 0.20 or more and 0.50 or less, preferably 0.20 or more and 0.40 or less, More preferably, they are 0.20 or more and 0.36 or less. If this value is less than 0.20 or more than 0.50, there may be a problem that it is difficult to obtain hydrotalcite particles in the form of a single phase.

Co-precipitation method using water-soluble divalent metal salt and water-soluble trivalent metal salt as metal raw materials and hydrothermal synthesis method using poorly soluble metal hydrate in the preparation of hydrotalcite-type layered metal hydrate used as a core according to the present invention. Is well known. Hydrotalcite particles according to the present invention may be prepared according to any one of a coprecipitation method and a hydrothermal synthesis method. Although the hydrothermal synthesis method was used in the embodiment of the present invention, the present invention is not limited to the hydrotalcite particles obtained according to this specific production method.

At this time, as a raw material of the divalent metal constituting the hydrotalcite particles usable as the core according to the present invention, there may be mentioned oxides, hydroxides, chlorides and salts of these metals. For example, magnesium sources include magnesium oxide (MgO), magnesium hydroxide (Mg (OH) ₂ ), magnesium chloride (MgCl ₂ ), magnesium nitrate (Mg (NO ₃ ) ₂ ), magnesium sulfate (MgSO ₄ ), and carbonic acid. It may be selected from magnesium (MgCO ₃ ), magnesium bicarbonate (Mg (HCO ₃ ) ₂ ), preferably magnesium chloride, magnesium oxide or magnesium hydroxide.

In addition, as a source of calcium (Ca), salts, hydroxides, oxides, and chlorides of calcium may be used. For example, calcium chloride (CaCl ₂ ), calcium nitrate (Ca (NO ₃ ) ₂ ), calcium sulfate (CaSO ₄ ), Materials selected from calcium hydroxide (Ca (OH) ₂ ), calcium sulfate (CaSO ₄ ), calcium oxide (CaO) and the like can be used. In addition, zinc oxides, hydroxides, chlorides, and salts of zinc (Zn) may be used as the source, and specifically, zinc oxide (ZnO), zinc hydroxide (Zn (OH) ₂ ), zinc chloride (ZnCl ₂ ), and zinc sulfate (ZnSO ₄ ), zinc nitrate (Zn (NO ₃ ) ₂ ), and the like.

Meanwhile, as a source of aluminum (Al), which is a trivalent metal component, oxides, hydroxides, salts, chlorides, and the like of aluminum may be used. For example, aluminum oxide (Al ₂ O ₃ ), aluminum hydroxide (Al (OH) ₃ ). ), Aluminum carbonate (Al ₂ (CO ₃ ) ₃ ), aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), aluminum nitrate (Al (NO ₃ ) ₃ ), aluminum phosphate (AlPO ₄ ), aluminum chloride (AlCl ₃ ) And the like.

Meanwhile, an alkali metal hydroxide may be used as a source for providing the hydroxyl group (OH ⁻ ) between the above-described metal layers. For example, ammonia, urea solution, as well as caustic soda (sodium hydroxide, NaOH) or potassium hydroxide (KOH) Etc. can be used. In addition, with respect to the interlayer anion (A ^n- ), it is already known to form the interlayer anion of hydrotalcite particles using various raw materials for each anion, and thus any known material can be used.

Specifically, the interlayer anions in a layered composite metal hydrate of hydrotalcite type carbonate ion (CO ₃ ^2-), nitrate ion (NO ₃ ^-), sulfate ion (SO ₄ ^2-), phosphate ion (PO ₄ ^{3 -)} and phosphorus (P), oxygen acids containing anions, such as hydroxide ion (OH ^-), fluoride ion (F ^-), chloride ion (Cl ^-), bromide ion (Br ^-), silicon (Si), such as SiO ₃ ^2- Containing oxygen acid anion, boron (B) -containing oxygen acid anion such as BO ₃ ^2- or CrO ₄ ^2- , Cr ₂ O ₇ ^2- . Specifically, as a source containing an interlayer anion, sodium carbonate (Na ₂ CO ₃ ), carbonic acid (H ₂ CO ₃ ), sodium bicarbonate (NaHCO ₃ ), potassium carbonate (K ₂ CO ₃ ), potassium hydrogencarbonate (KHCO ₃ ), phosphoric acid Inorganic materials such as sodium (Na ₃ PO ₄ ), sodium silicate (Na ₂ O-nSiO ₂ -xH ₂ O), sodium sulfate (Na ₂ SO ₄ ), as well as organic carbonates, organic sulfates, and organic phosphates Can be used.

The addition or mixing component of a metal raw material component, an anion source and an alkali component as a component for producing hydrotalcite particles used as a core material for forming the hollow composite of the present invention is not particularly limited, and according to the present invention The content of each metal component can be adjusted by adjusting the input amounts of the raw materials of metal components, hydroxide ions and interlayer anions, and adjusting the mole fraction of magnesium (Mg), which is the main component of the divalent metal component, and aluminum (Al), which is the trivalent metal component. Is well known. That is, the value of x, which is a mole fraction of Al, which is a trivalent metal component in the layered composite metal hydrate in the form of hydrotalcite particles represented by Formula 2, is usually 0.20 or more and 0.50 or less, preferably 0.20 or more and 0.40 or less, More preferably, they are 0.20 or more and 0.36 or less. If the value of this mole fraction is less than or above the above-mentioned range, there may be a problem that it is difficult to obtain hydrotalcite particles in the form of a single phase.

In particular, the hydrotalcite according to the present invention may be hydrotalcite in which all or part of water molecules are removed by heat treatment, in addition to the above-described formula (2). As is well known, heat treatment of hydrotalcite to approximately 140 to 180 ° C. leads to a dehydration reaction in which water molecules, ie, crystal water, are removed between the layers of hydrotalcite, resulting in a dehydration intermediate (metahydrotalcite-D, HT-D) is produced, and a heat treatment at 240 to 260 ° C. results in a dehydroxylation reaction in which some of the hydroxide ions surrounding the metal cations are removed, thereby removing some hydroxide ions (metahydrotalcite B, HT-B ), And the heat treatment at a temperature above 500 ℃ removes the remaining hydroxide ions and at the same time, a decarbonation reaction occurs in which the interlayer anion is removed (TS. Stanimorova et al., Thermal decomposition products of hydrotalcite-). like compounds: low-temperature metaphases, Journal of Materials Science 34, pp. 4153-4161, 1999).

Here, partially dehydrated hydrotalcite is hydrotalcite containing crystallized water at high temperature to remove the crystallized water contained in hydrotalcite, and some hydroxide ions contained in hydrotalcite are converted into water and oxide ions. Dehydration reaction (2OH- → H ₂ O + O ^2- ) is decomposed hydrotalcite, which is partially dehydrated hydrotalcite is octahedral with six hydroxide ions surrounding the metal cation due to dehydration Part of the structure disappears, converting four hydroxide ions into a tetrahedron structure surrounding the metal cation, resulting in a mixture of octahedral and tetrahedral structures in the double layer (see above; Ts. Stanimirova et al., Theraml evolution of Mg- Al-CO ₃ hydrotalcites, Clay Minerals 39 , pp. 177-191, 2004). Therefore, the hydrotalcite used in the present invention should be understood to include not only the compound of Formula 2 described above, but also partially dehydrated hydrotalcite, or hydrotalcite from which the crystal water is completely removed. do. The partially dehydrated hydrotalcite may be obtained by heat-treating the hydrotalcite represented by Formula 2 at a temperature of 200 to 260 ° C., preferably 220 to 250 ° C., and may be represented by the following Formula 3.

Formula 3

M ²⁺ _1-x M ³⁺ _x (OH) _2-y O _y (A ^n- ) _{x / n} ? MH ₂ O

(In Formula 3, M ²⁺ , M ³⁺ , (OH), x and m are as defined in Formula 2, and 0 <y ≦ 1.)

Meanwhile, the partially dehydrated hydrotalcite in a form in which the crystal water is completely removed may be represented by the following formula (4).

Formula 4

[M ²⁺ _1-x M ³⁺ _x (OH) ₂ ] ^{x +} (A ^n- ) _{x / n}

(In Formula 4, M ²⁺ , M ³⁺ , (OH), x and A ^n- are the same as defined in Formula 2).

In addition, the hydrotalcite used as the core according to the present invention may be a form in which the interlayer anion (A ⁿ⁻ ) of the hydrotalcite of Formula 2 described above is removed. For example, the interlayer anion may be a carbonate or nitrate ion. When an anion derived from an inorganic acid is synthesized, such an interlayer anion may be removed by heat treatment (firing) at a temperature in the range of 500 ° C. or higher, for example, 500 to 700 ° C.

At this time, in order to form a plate-shaped hollow composite according to the present invention, it is necessary to adjust the form of the hydrotalcite used as a core to a plate-like form, the type of water-soluble compound added to the reaction for producing hydrotalcite, metal hydroxide By properly selecting the addition ratio of the water-soluble metal compound, the type of the interlayer anion component, the reaction temperature, and the reaction time, the particle shape as well as the particle size of the hydrotalcite used as the core can be changed into a regular plate shape, for example, hexagonal plate shape. Hydrotalcite in the form of an elliptical form having a constant curvature or a cross-sectional shape of a convex lens can be easily manufactured as well as an irregularly shaped plate.

On the other hand, as the inorganic particles constituting the inorganic core, metal hydroxides may be mentioned in addition to the hydrotalcite described above. Among the metal hydroxides, they are soluble in the range of pH 0.5 to 3.0 and can be etched by strong acids (hydrochloric acid, sulfuric acid, etc.), and metal hydroxides having plate, spherical and elliptic shapes can also be used. In the present invention, the metal hydroxide constituting the inorganic core may be a material selected from the group consisting of aluminum hydroxide, apatite hydroxide, magnesium hydroxide, and calcium hydroxide.

On the other hand, the metal oxide as another example of the inorganic particles capable of forming the inorganic core can also be used in the form of a plate, sphere or oval, preferably in the form of a plate, the usable inorganic material is zinc oxide which can be etched by a strong acid And metal oxides selected from the group consisting of (ZnO), iron oxide and zeolite. At this time, the metal oxide that can be used as the core may be used in the form of a plate, it can be synthesized according to the size and shape of the hollow composite finally prepared according to the present invention. Methods for synthesizing metal oxides of nano powder size include physical methods such as gas evaporation; Chemical liquid phase methods such as sol-gel method or hydrothermal synthesis method; The well-known methods, such as an aerosol method, gaseous-gas decomposition method, chemical vapor deposition method, or chemical vapor deposition method, such as a chemical vapor deposition method, are mentioned. Nano-sized metal oxides having a plate-like shape may be synthesized according to temperature conditions and surrounding atmosphere in the synthesis process.

In addition, metal carbonates soluble in a strong acid atmosphere in the range of pH 0.5 to 3.0 may be used as another core in the present invention, for example, metal carbonates such as calcium carbonate, magnesium carbonate, hydromagnesite, strontium carbonate and the like.

Subsequently, the magnesium fluoride-doped silica composite sol prepared in step s140 is reacted with the inorganic core particles prepared in step s150, so that the shell of magnesium fluoride-doped silica and the core-consisting of the above-described inorganic core- To form particles of the shell structure (step S160). In this step, a gelation reaction is carried out through condensation of the hydrolyzed silica precursor and magnesium fluoride to form a shell portion, through which the hydrolyzed precursor forms a siloxane bond (-Si-O-Si-), condensation and gelation. do. Such condensation reactions can be classified into dehydration condensation and alcohol condensation reactions. In the dehydration condensation reaction, water is removed while forming a siloxane bond through the hydroxy bond introduced into the precursor during the hydrolysis reaction. In the alcohol condensation reaction, alcohol is removed while forming a siloxane bond through the bonding of a hydroxy group and an alkoxy group. The method of advancing such condensation and gelation reaction is not specifically limited, For example, it can carry out by stirring a mixture under suitable temperature conditions. On the other hand, the metal fluoride forms a composite structure in the form doped with silica.

The composite that formed the core-shell exhibits strong alkalinity in the synthesis step (s160). In this case, when the core is immediately removed, the pH change range is large, and since the pH of the neutral region is excessive, there is a fear that abrupt aggregation and impact of the composite particles occur. Therefore, it is preferable to use a method of removing the core more stably through the primary filter and the washing step for the core.

Then, the step of removing the core is performed (step s170). The hydrotalcite or metal oxide used as the core according to the present invention can be removed in a strong acidic condition such as hydrochloric acid or sulfuric acid, for example, at an pH of about 0.5 to 3.0. In particular, in the case of removing the metal oxide to obtain a hollow structure after growing the silica particles using the metal oxide as a template, it may be difficult to exhibit the light diffusion property as the metal oxide used as the template remains. Therefore, it was confirmed that preferably hydrotalcite can be easily and completely removed under strong acid conditions.

In particular, in the present invention, the hydrotalcite, which can easily control its shape and size, is used as the core, and the magnesium fluoride-silica composite forms the shell portion on the surface of the hydrotalcite used as the core. Therefore, the shell portion may also be manufactured in a plate shape in response to the hydrotalcite core manufactured in the plate shape.

After removing the core to prepare the desired hollow composite, as an additional process, a primary filtering step of removing the reaction by-products and impurities using a filtration device (s180), for example, a hollow composite powder from which the reaction by-products and impurities have been removed For example, the high pressure reaction step (s190) to put into a high pressure reactor in the range of 100 ~ 300 ℃ for 1 to 48 hours, moisture hygroscopicity in the pores of the hollow composite structure, organic solvents, resin penetration characteristics of organic solvents and dispersibility to resins In order to improve the surface treatment using an appropriate coupling agent and the like, a filtering step of adjusting the content of Na ions to 100 ppm or less by removing impurities using a cation and an anionic resin and the mature hollow composite powder is performed ( s200 steps). Finally, the hollow composite may be subjected to a drying step (drying / heating process) for 1 to 48 hours at 100 to 200 ° C. and / or to firing for 1 to 48 hours at a range of 200 to 500 ° C. (baking treatment process) ( step s210).

Note that the surface treatment step is possible even after the high pressure aging step, but it is also possible to proceed immediately after the core is removed, or may be performed immediately after the first filtering step s180 or the high pressure aging step s190.

Silane coupling agents for surface treatment can be used, for example, silane-based, aluminum-based, titanium-based, zirconium-based coupling agents, and as silane-based coupling agents, 3-methacryloxypropyltrimethoxysilane, 3-methacryl Oxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxy-ethoxy) -silane, 2- (acryloxyethoxy) trimethylsilane, N- (3-acrylic Oxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, (3-acryloxypropyl) methyl bis- (trimethylsiloxy) silane, (3- Acryloxypropyl) methyldimethoxysilane, 3- (N-arylamino) propyltrimethoxysilane, aryldimethoxysilane, aryltriethoxysilane, butenyltriethoxysilane, 2- (chloromethyl) aryltrimeth Methoxysilane, [2- (3-cyclohexenyl) ethyl] trimethoxysilane, 5- (bicycloheptenyl) t Liethoxysilane, (3-cyclopentadienylpropyl) triethoxysilane, 1,1-diethoxy-1-silyl acrylopen-3ene, (perfuryloxymethyl) triethoxysilane, O- ( Ethaacryloxyethyl) -N- (triethoxysilylpropyl) urethane, N- (3-methacryloyl-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (methacryloxymethyl) bis (Trimethylsiloxy) methylsilane, (methacryloxymethyl) dimethylethoxysilane, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, 3-methacryloxypropyl bis (trimethylsiloxy) methyl Silane, methacryloxypropyldimethylmethoxysilane, methacryloxypropyldimethylmethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, (3-acryloxypropyl) trimethoxysilane, Methacryloxypropyl tris (methoxyethoxy) sil , Methacryloxypropyl tris (vinyldimethoxysiloxy) silane, 3- (N-styrylmethyl-2-aminoethylamino) -propyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyl Triethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl)- 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl ) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3 -Glycidyloxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysil Column, 3-mercaptopropylmethyldimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxy silane, dimethyldimethoxysilane, Dimethyldiethoxysilane, 3-aminopropylmethyldiethoxysilane and 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane.

As a titanium coupling agent, isopropyl triisostearo titanate, isopropyl tridioctyl phosphate titanate, tetraisopropyl di lauryl phosphito titanate, titanium didioctyl phosphate oxyacetate, or diiso Stearoylethylene titanate and the like can be used.

As a zirconium coupling agent, zirconium tetraene propoxide, zirconium isopropoxide, zirconium butoxide, or zirconium tetrachloride, etc. can be used, and aluminum coupling agent, aluminum ethoxide, aluminum isopropoxide, aluminum Enbutoxide, tributoxyaluminum, etc. can be used.

As a fluorine-type organic substance, the substance which has hydrophobic characteristic is preferable, For example, compounds, such as 1H, 1H, 2H, 2H- perfluorooctyl trichlorosilane (1,1,2,2-perfluorooctyl trichlorosilane), are mentioned.

For example, fluorine-based organic compounds or silanes for the purpose of further improving the hygroscopicity, the penetration of organic solvents and resins, and the dispersibility of the silica composite hollow powder doped with magnesium fluoride, which is a hollow silica structure having improved hygroscopicity and scratch resistance. A mixture of the coupling agent and the silane coupling agent having a phenyl group may be used in the range of 0.5 to 50% by weight, preferably 0.1 to 20% by weight, based on the composite hollow body.

Meanwhile, in relation to step s190, a process (drying process) of hydrothermally treating the manufactured hollow composite at 100 to 300 ° C. for 1 to 48 hours may be performed first. Subsequently, a process of firing for 1 to 48 hours at 200 to 500 ° C., which is higher than the heating process, may be performed. This reduces the pore size present on the shell surface of the magnesium fluoride-doped silica composite hollow body forming the shell portion of the hollow composite according to the present invention and improves the film density of the shell structure. This makes it possible to prevent the penetration of the resin and the solvent.

3. Application

The hollow composite according to the present invention can be utilized for various applications. In one example, the substrate to which the hollow composite of the present invention may be attached may be formed on the surface of the substrate alone or in combination with other coatings, including the hollow composite of the present invention and the film-forming matrix. Such substrates include glass, polycarbonate, acrylic resins, polyethylene glycol (PET), plastic sheets such as triacetyl cellulose (TAC), plastic films, plastic lenses, substrates such as plastic panels, CRTs, and liquid crystal display devices. And a film formed on the display surface. Depending on the application, it may be a protective film, a hard coat film, a planarization film, an insulating film, a low dielectric constant film, a thermal barrier film, a conductive metal fine particle film, etc., on the desired substrate. It can apply | coat to a base material by methods, such as a dip method and a spray method, and it can dry and harden | cure by heating or ultraviolet irradiation etc. as needed.

In particular, the light diffusing agent dispersed in a predetermined amount in a predetermined matrix resin (binder) by using the properties of the hollow composite prepared according to the present invention can be applied as a light diffusion structure is laminated or applied. The resin constituting the light diffusing agent according to one aspect of the present invention may be any resin currently used in the light diffusing agent as a transparent thermoplastic, thermosetting or photocurable resin. Especially preferably, the transparent plastic resin with good light transmittance is preferable.

The resin is not particularly limited as long as it is commonly used in a light diffusion composition, preferably polyvinyl alcohol, ethylene vinyl copolymer, acrylic resin, polycarbonate resin, polyester resin, styrene resin, alkyd resin , Thermosetting or ultraviolet curing resins such as amino resins, polyurethane resins, epoxy resins, and the like can be used. For example, transparent thermoplastic resins or thermosetting resins include polyolefin resins including olefin copolymers such as polyvinyl alcohol and ethylene vinyl alcohol, polycarbonate (PC) resins, polyacrylic acid and esters thereof, for example , Polymethacrylic acid such as polyalkyl methacrylate resin which is polymethyl methacrylate, acrylic resin such as ester thereof, polyether amide resin, polyether sulfone (polyether sulfone) resins, polyester resins including aromatic polyesters, polyarylate resins, styrene resins such as polystyrene (PS) resins, alkyd resins, amino resins, polyurethane resins, Glycidyl ester epoxy resins such as poly- (meth) acrylic acid glycidyl esters and derivatives thereof, bis A play system may be mentioned epoxy (epoxy) resin and the like, such as an epoxy resin, a hydrogenated bisphenol A epoxy resins, bisphenol F-type epoxy resin, novolak type epoxy resin. Among them, aromatic polyester resins having good dimensional stability and mechanical properties are particularly preferred. For example, polyethylene terephthalate (PET), polypropylene terephthalate (PPT), and polyethylene-2,6-nat. Thylene carboxylate, poly-1,4-cyclohexylene dimethylene terephthalate, and the like.

In particular, the hollow composite prepared according to the preferred embodiment of the present invention has a much lower refractive index than the refractive index of the above-mentioned substrate when used as a light diffusing agent, so that the light diffusion efficiency and the front brightness are particularly increased.

Generally, the binder resin in the light diffusing agent is preferably 10 to 90% by weight. This is because when the content of the binder resin is less than this, the adhesion to the base film described later is insufficient, and when it exceeds this, it is difficult to obtain sufficient light diffusion efficiency. At this time, the plate-shaped hollow particles according to the present invention can be blended and dispersed in a proportion of 0.1 to 200 parts by weight, preferably 10 to 20 parts by weight, more preferably 100 to 200 parts by weight with respect to 100 parts by weight of the binder resin described above. have. It is because acid resistance and hiding power may fall that the compounding ratio of the plate-shaped hollow particle which concerns on this invention is less than the above-mentioned range, and when it exceeds the said range, there exists a possibility that light transmittance may fall.

In particular, when the light diffusing agent is to be used in liquid form, it may further include an organic solvent used for light diffusion. The organic solvent may be blended in a uniformly dispersed state in the light diffusing agent such that the concentration of the binder resin and the hollow composite described above is about 5 to 60%. Possible solvents include alcohols such as diacetone alcohol and propylene glycol; Glycol ethers such as ethylene glycol monomer ethyl ether; Ethylene glycol alkyl ether acetates such as methyl / ethyl cellosorb acetate; Diethylene glycol alkyl ethers such as diethylene glycol monomethyl ether; Propylene glycol alkyl ether acetates such as propylene glycol motor methyl ether acetate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; Ester, such as alkyl 2-hydroxypropionate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and 3-methoxy propionate, etc. can be used individually or in mixture. Preferably, toluene, dichloromethane, methyl ethyl ketone, cyclohexanone, xylene, cyclohexane and the like can be used as the solvent having a low volume resistivity to improve the luminance characteristics and the luminance uniformity.

 In addition to the above-mentioned binder resin and the hollow particles according to the present invention, among the light diffusing agents, functional additives such as fluorescent brighteners, crosslinking agents, heat stabilizers, oxidation stabilizers, ultraviolet absorbers, lubricants, fillers, antistatic agents, dispersants, coupling agents, etc. Can be added.

It may include a variety of additives such as dispersing agents, curing agents, antistatic agents, leveling agents commonly used in the light diffusion composition, preferably using an additive of 0.1 to 10% by weight based on 100% by weight of the polymer resin. It is suitable because the additive does not significantly inhibit the luminance characteristics of the.

For example, when applied to a lighting device such as an LED by using the light diffusing agent according to the present invention, the light diffusing agent may include a color conversion phosphor in the light diffusing agent, 0.1 to 100 parts by weight of the total light diffusing agent ˜5.0 parts by weight is preferred. As such color conversion phosphors, known phosphors such as YAG-based yellow phosphors, iridium-based / lithium-manganese-based red phosphors, and iridium-based / zinc-based cesium-calcium-magnesium-based phosphors can be used.

 The light diffusing agent containing the composite hollow particle according to the present invention may have a form of a light diffusing composition liquid through blending with a resin. Alternatively, the composite hollow particle according to the present invention may be prepared in a solid form in the form of a masterbatch or compound pellet prepared through an extrusion process after mixing with a binder.

In addition, the light diffusing agent containing the hollow composite according to the present invention may be applied as a light diffusing structure that is mixed with a suitable substrate or laminated or applied to the surface of the substrate. In this case, the above-described light diffusing agent may be applied or laminated on the surface opposite to the light source of the substrate, and may also be applied or laminated on the light source side surface of the substrate to increase the haze. At this time, in the case of using a thermosetting or photocurable resin as the binder resin included in the light diffusing agent, the binder may be cured by light or opening after applying or laminating the light diffusing agent on the surface of the substrate. In the case of laminating the light diffusing agent on the surface of the substrate in the form of a light diffusion layer, a known coating method such as brush coating, roller coating, blowing coating, electrodeposition coating, electrostatic coating, ultraviolet curing coating, airless spray, roll coat, dip coating, and the like Inner coats such as gravure coat, air knife coat, spray coat, wheeler cotto, gravure printing, gravure offset printing, flatbed offset printing, dilithography printing, convex printing, intaglio printing, silk screen printing, electrostatic printing, inkjet printing, etc. Or by a printing method. The coating thickness of the light diffusing agent is generally in the range of 1 to 50 µm. It is because there exists a possibility that a haze may fall when it is less than 1 micrometer, and light transmittance may fall when it exceeds 50 micrometers. In addition, if necessary, a separate layer having a function such as an antistatic function, a scratch prevention function, an antireflection function, or the like may be laminated on one or both surfaces of the substrate.

The light diffusing structure may be laminated or applied to a suitable substrate and extrusion, or through mixing and surface, for example, in the form of fillers, beads, pellets. Suitable substrates to which the light diffusing agent may be laminated or applied include substrates having a total light transmittance of 80 to 100%, preferably 90 to 100%, and a haze of 0 to 5%, preferably 0 to 1%. . For example, glass, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polypropylene, polyethylene, acetyl cellulose, vinyl chloride resin, etc. are mentioned. In this case, the substrate on which the light diffusing agent is laminated or applied may be in the form of a sheet, a film, or a panel, thereby applying the light diffusion sheet, the light diffusion film, or the light diffusion panel containing the plate-shaped hollow particles according to the present invention. Can be. At this time, for example, when used as a light diffusion film, the thickness applied or laminated on the substrate is not particularly limited, but is, for example, in the range of 10 to 2000 µm, preferably 30 to 1000 µm.

The light diffusing agent containing the hollow particles according to the present invention may be utilized as a light diffusing structure laminated or coated on a suitable substrate. As an example of the light diffusion structure, a light diffusion film / light diffusion sheet constituting a light guide plate or a diffusion plate of a backlight unit of an LCD, as well as a light diffusion member applied by wrapping an LED chip or LED packaging mounted on a substrate, Or the base material which is a light-diffusion film or sheet for organic electroluminescent elements (OLED), the light-diffusion panel of a PDP panel, etc. are mentioned, but this invention is not limited to this. For example, the masterbatch or compound pellets prepared through the extrusion operation using the light diffusing agent according to the present invention can be manufactured in the form of LED (LED) lampshade, bulb or tube by extrusion or injection process. . In addition, the light diffusing agent containing the hollow particles of the present invention can be used as a surface light emitting device having a light diffusing structure laminated or coated on a suitable substrate.

For example, the light-diffusion structure containing a predetermined amount of hollow composite particles according to the present invention in a binder has good heat insulating properties. Therefore, when used as a diffusion plate of a liquid crystal display (LCD), since the diffusion plate does not bend to the front part of the backlight unit due to heat from a light source such as a cold polar fluorescent lamp (CCFL) or an LED, According to the deformation of the liquid crystal module, it is possible to prevent the egmura phenomenon due to the difference in the thickness of the liquid crystal. Therefore, one example of the application of the hollow composite particles of the present invention is a backlight unit assembly used as a diffusion plate of an LCD as a light diffusion structure. In addition, as an applicable surface light emitting device, a display such as an LED package manufactured by mixing a filler containing the hollow particles of the present invention with an epoxy resin or a silicone resin used as a coating or encapsulating agent in a form of surrounding an LED chip formed on a substrate. , LED assembly for lighting or advertisement, PDP panel, etc. are mentioned. In addition, it is possible to apply to the light diffusion substrate used for LED lighting.

Hereinafter, the present invention will be described in detail with reference to exemplary embodiments, but the present invention is by no means limited to these examples.

Example 1 Preparation of Composite Hollow Shells

_{Mg 0 .67 Al 0 .33 (OH} ) 2 (CO 3) 0.167? 0.5H 2 for the production of the hydrotalcite particles used in the core of the structure O, aluminum hydroxide as a raw material component of aluminum (Al (OH) ₃ , 99.9%) 13.21 kg and 49.32 kg of caustic soda (NaOH, 50%) as a raw material of hydroxide ions and 1000 kg of water were added to a 1 m ³ reactor, heated at 100 ° C. for 2 hours, and dissolved in sodium aluminate. ) Solution (A) was prepared. As a raw material of the magnesium component, 167 kg of aqueous magnesium chloride solution (MgCl ₂ , 30%) was completely dissolved in 1000 kg of water to prepare a solution (B). Solution (C) was prepared by dissolving 10.25 kg of sodium bicarbonate (NaHCO ₃ , 99.99%) in 1500 kg of water. The prepared A, B, C solution was added dropwise to the 20 m ³ reactor capable of stirring more than 3000 rpm at a temperature of 40 ~ 95 ℃ for 1 to 24 hours to prepare a hydrotalcite (D) of 8% of the solid content. The prepared hydrotalcite (D) was placed in a hydrothermal synthesis reactor and reacted at 100 to 200 ° C. for 1 to 24 hours to crystallize by adjusting the particle size to an average size of 80 nm to 10 μm. Crystallized hydrotalcite (E) was prepared. An SEM photograph of the hydrotalcite particles prepared according to this example is shown in FIG. 2. It was confirmed that a hydrotalcite core having a plate shape was produced.

Subsequently, in order to manufacture the shell portion, a value of 0.005 is composed of (MgF ₂ ) _(a) SiO _{2 (1-a)} , which is a silica composite structure doped with a magnesium fluoride molar concentration of 0.005. As a raw material of magnesium fluoride, a solution (F) in which 5.366 kg of magnesium chloride (MgCl ₂ , 30%) was dissolved in 1000 kg of water was prepared. Solution (G) was prepared by dissolving 1.252 kg of ammonium fluoride (NH ₄ F _, 98%) completely in 2000 kg of water. A solution (H) was prepared by completely dissolving 663.15 kg of water glass (SiO ₂ solid content 30%) constituting silica in 1000 kg of water. The prepared solutions F, G, and H were added to a 20 m ³ reactor, respectively, and dropped in a range of 60 to 90 ° C. for 1 to 24 hours using a metering pump to prepare a sol (I) constituting the composite hollow body.

The crystallized hydrotalcite (E) prepared above was dispersed after adding 500 kg to 20 m ³ . Then, the sol (I) constituting the manufactured composite hollow body was dropped in a 20 m ³ reactor in which crystallized hydrotalcite (E) was dispersed in a range of 60 to 95 ° C. for 1 to 24 hours using a metering pump. Shell-formed composite particles (J) were prepared. In order to remove the core of the core-shell composite particles, hydrochloric acid was added thereto until the pH was 3 or less, followed by stirring at room temperature for 24 hours to prepare a hollow composite having the core removed. Reaction byproducts and impurities were removed using a filtration device. In order to increase the purity and purity of the crystal structure of the hollow composite shell from which the reaction product and impurities were removed, the mixture was placed in a high pressure reactor and aged for 1 to 48 hours in the range of 100 to 300 ° C.

83.07 kg of 3-methacryloxypropyltrimethoxysilane (Shin-Etsu, Japan, trade name; KBM 503) and 0.85 kg of catalyst (0.1 N hydrochloric acid) were added dropwise to the aged reaction product to adjust the reaction pH to 3, and then at room temperature 24 The reaction was carried out for a time and surface treated with a silane coupling agent. The surface of the composite hollow structure was modified to remove impurities using cation and anionic resin to adjust the Na content to 10ppm or less. The prepared composite hollow particles were filtered through a filtration apparatus, dried at 100 to 200 ° C. for 10 hours, and calcined to dry powder at 200 to 600 ° C. for 1 to 48 hours to prepare a powder.

Examples 2 to 14 Preparation of Composite Hollow Body

Magnesium chloride (MgCl) was prepared to synthesize a composite hollow body having a weight ratio of magnesium fluoride (MgF ₂ ) doped to silica by synthesizing the average particle size of hydrotalcite used as the core to approximately 200 nm. ₂ , 30%), ammonium fluoride (NH ₄ F _, 98%), water glass (SiO ₂ solid content 30%) was added to the amount shown in Table 1, except that the shell portion of the hollow composite structure was formed, The procedure was performed in the same manner as in Example 1 to prepare a composite hollow shell.

Example 15 Preparation of Composite Hollow Body

MgF ₂ doped with silica, except for the use of hydrotalcite used as a core instead of ZnO (average particle size of 1 μm) mixed with hexagonal columns or cubic phases of SBC (Korea). In order to produce a composite hollow body having a weight ratio of as shown in Table 1 below, raw materials of magnesium chloride (MgCl ₂ , 30%), ammonium fluoride (NH ₄ F _, 98%), and water glass (SiO ₂ solids 30%) were prepared. A composite hollow shell was prepared in the same manner as in Example 1, except that the same amount as shown in Table 1 was added to form the shell portion of the hollow composite structure. TEM picture of the metal oxide used as the core is shown in Figure 3, it was confirmed that the plate-like form.

Example 16: Preparation of Composite Hollow Body

In order to produce a composite hollow body in which the weight ratio of magnesium fluoride (MgF ₂ ) doped to silica is shown in Table 1, except that the average particle size of hydrotalcite used as the core is synthesized at approximately 500 nm. The raw material of magnesium chloride (MgCl ₂ , 30%), ammonium fluoride (NH ₄ F _, 98%), and water glass (30% of SiO ₂ solids) was added in the amounts shown in Table 1 to form the shell portion of the hollow composite structure. The procedure was performed in the same manner as in Example 1 except that a composite hollow shell was prepared.

Example 17 Preparation of Composite Hollow Body

In order to produce a composite hollow body in which the weight ratio of magnesium fluoride (MgF ₂ ) doped to silica is shown in Table 1, except that the average particle size of the hydrotalcite used as the core is synthesized to approximately 2 μm. The raw material of magnesium chloride (MgCl ₂ , 30%), ammonium fluoride (NH ₄ F _, 98%), and water glass (30% of SiO ₂ solids) was added in the amounts shown in Table 1 to form the shell portion of the hollow composite structure. The procedure was performed in the same manner as in Example 1 except that a composite hollow shell was prepared.

Comparative Examples 1 to 8: Preparation of Composite Hollow Shells

Magnesium chloride (MgCl ₂ , 30%), ammonium fluoride (NH ₄ F _, 98%), to prepare a composite hollow body having a molar concentration of magnesium fluoride (MgF ₂ ) doped in silica as shown in Table 1 below A composite hollow shell was prepared in the same manner as in Example 1, except that the raw material of the water glass (30% of SiO ₂ solids) was added in the amount shown in Table 1 to form the shell portion of the hollow composite structure.

Comparative Examples 9-13: Commercial Products

Comparative Example 9 Silicon beads, Comparative Example 10 PMMA beads, Comparative Examples 11 and 12, the size of the mar calcium calcium particles of 1000 nm and 8000 nm, respectively, and Comparative Example 12 used GRANDEX (manufactured by Nisan) product name: Nanoballoon. Table 1 below shows the molar ratio of magnesium fluoride to silica, as well as the dosage of the main components in the above-described examples and comparative examples.

Raw material input to form shell of composite hollow structure Doped with SiO ₂
Molarity of MgF ₂ MgCl ₂ (30%)
Unit kg NH ₄ F (98%)
Unit kg Water glass (30%)
Unit kg Example 1 0.005 5.366 1.252 663.15 Example 2 0.006 6.439 1.502 662.45 Example 3 0.008 8.857 2.003 661.05 Example 4 0.01 10.732 2.504 656.89 Example 5 0.02 21.446 5.008 652.63 Example 6 0.04 42.928 10.016 638.63 Example 7 0.05 53.66 12.520 631.64 Example 8 0.06 64.39 15.02 624.66 Example 9 0.07 75.124 17.528 617.68 Example 10 0.08 88.57 20.03 610.713 Example 11 0.1 107.32 25.04 596.80 Example 12 0.15 160.98 37.56 562.14 Example 13 0.2 214.46 50.08 527.68 Example 14 0.25 268.30 62.60 493.386 Example 15 0.05 53.66 12.494 631.64 Example 16 0.05 53.66 12.494 631.64 Example 17 0.05 53.66 12.494 631.64 Comparative Example 1 0.3 320.322 75.12 459.278 Comparative Example 2 0.5 536.60 125.20 324.63 Comparative Example 3 0.6 643.90 150.20 258.32 Comparative Example 4 0.8 885.70 200.30 127.85 Comparative Example 5 0.9 965.88 225.34 63.60 Comparative Example 6 One 1018.728 237.772 0 Comparative Example 7 0.05 53.66 12.520 631.64 Comparative Example 8 0.002 2.145 0.501 662.01 Comparative Example 9 ^* Silicon beads - - - Comparative Example 10 ^* PMMA Bead - - - Comparative Example 11 ^* Calcium Carbonate Bead - - - Comparative Example 12 ^* Calcium Carbonate Bead - - - Comparative Example 13 ^* Grandex - - -

^* : Particles sold commercially

Experimental Example 1: Evaluation of physical properties of the prepared composite hollow shell

In the present experimental example, the average particle size and the hollow shell thickness of the magnesium fluoride-doped silica composite hollow bodies prepared in Examples 1 to 17 and Comparative Examples 1 to 13, respectively, were measured. In addition, the average particle size of the hollow body was measured by particle size distribution measurement by laser diffraction scattering method, and the average particle diameter was MV value obtained after the particle size distribution measurement as the average secondary particle diameter. In addition, it was taken by TEM to observe the synthesized hollow shell particles. The analysis results of the composite hollow bodies prepared in the present example and the comparative example are shown in Table 2 below.

In addition, in relation to shell formation, the shape of the shell of the composite hollow body prepared through TEM analysis was analyzed. The meanings of the results shown in Table 2 are as follows.

Top: ◎ (the shell is not broken)

Medium: ◆ (some shells are broken)

Lower: ■ (Shell is severely broken)

4 is a FE-SEM photograph (30,000 times magnification) of the hollow composite cell of Example 3, FIG. 5 is a TEM photograph of the composite hollow shell, and FIG. 6 is a FE-SEM of the hollow composite shell of Example 5. Photo (30,000 times magnification), FIG. 7 is a FE-SEM photo (30,000 times magnification) of the hollow composite shell of Example 6, and FIG. 8 is a TEM photograph of the hollow composite shell of Example 16. FIG. On the other hand, Figure 9 is a TEM picture of the hollow composite shell of Comparative Example 1, Figure 10 is a FE-SEM picture (30,000 times magnification) of the hollow composite shell of Comparative Example 3, Figure 11 is a hollow composite shell of Comparative Example 3 Figure 12 is a TEM picture, Figure 12 is a TEM picture of the hollow composite shell of Comparative Example 4, Figure 13 is a TEM picture of the hollow composite shell of Comparative Example 6. It can be seen that the hollow composite shell prepared according to the embodiment of the present invention has a good hollow structure.

Measurement of physical properties of hollow composite shell doped with MgF ₂ Doped
MgF ₂ amount (%) Average particle
Size ^** (nm) Longitudinal direction
Length (nm) Shell thickness
(Nm) Aspect ratio Shell formation Particle shape Example 1 0.005 287 230 18 1.3 ◎ Plate Example 2 0.006 298 220 18 1.4 ◎ Plate Example 3 0.008 260 210 18 1.2 ◎ Plate Example 4 0.01 280 210 18 1.3 ◎ Oval Example 5 0.02 290 200 17 1.5 ◎ Oval Example 6 0.04 275 210 18 1.3 ◎ Oval Example 7 0.05 320 198 18 1.6 ◎ Oval Example 8 0.06 278 200 15 1.4 ◎ Oval Example 9 0.07 278 210 18 1.3 ◎ Oval Example 10 0.08 256 220 20 1.2 ◎ Plate Example 11 0.1 286 160 20 1.8 ◎ Plate Example 12 0.15 260 115 22 2.3 ◎ Plate Example 13 0.2 255 120 21 2.1 ◎ Plate Example 14 0.25 243 100 21 2.4 ◎ Plate Example 15 0.05 1000 - 18 - ◎ Hexagonal Column, Cubic Example 16 0.05 510 210 21 2.43 ◎ Plate Example 17 0.05 2100 220 20 9.5 ◎ Plate Comparative Example 1 0.3 20 to 270 150 21 1.9 Or solid Plate-shaped Comparative Example 2 0.5 20 to 270 100 20 2.7 Or solid Plate-shaped Comparative Example 3 0.6 20 to 270 150 25 1.7 Or solid Plate-shaped Comparative Example 4 0.8 20 to 60 - - - Solid particles rectangle Comparative Example 5 0.9 20 - - - Solid particles rectangle Comparative Example 6 One 18 - - - Solid particles rectangle Comparative Example 7 0.05 285 280 21 1.02 ◎ rectangle Comparative Example 8 0.002 255 210 50 1.21 ◎ Plate Comparative Example 9 ^* - 2500 - - - Solid particles rectangle Comparative Example 10 ^* - 6500 - - - Solid particles rectangle Comparative Example 11 ^* - 1800 - - - Solid particles Cubic Comparative Example 12 ^* - 8000 180 - - ◎ Cubic Comparative Example 13 ^* - 170 180 - 0.94 ◎ Cubic

^* : Particles sold commercially

^** : transverse length

   Comparative Example 9: Inorganic spherical silicon beads (2.5 μm)

   Comparative Example 10 Domestic S company spherical 6.5 ㎛ PMMA beads

   Comparative Example 11: Marcalcium (Japan) 1.8 μm Light Diffusion Bead

   Comparative Example 12: Marcalcium (Japan) 8 μm Light Diffusion Bead

Comparative Example 13: Granddex (Japan) 150-300 nm hollow silica

Experimental Example 1: Evaluation of Physical Properties

1.0 parts by weight of the final silica bead light diffusing agent obtained in Comparative Examples 1 to 13 and 100 parts by weight of a polycarbonate resin (CALIBER200-3 manufactured by LG-DOW) were mixed by mixing the powder prepared through Examples 1 to 17 described above and After extruding at 210 ° C to make a light diffusion compound pellet (pellet), it was melt-extruded in an extruder of 250 to 270 ° C to prepare a light diffusion plate having a thickness of 2.0 mm.

[Property evaluation method]

The physical properties of the light diffusing agent obtained in this example were evaluated by the following method.

(1) moisture absorption rate

Using the powders of Examples 1 to 17 and Comparative Examples 1 to 13, the light diffusing plate prepared in Experimental Example 1 was cut into 5 cm x 15 cm specimens and dried in an oven at 80 ° C. for 24 hours. After measuring the weight (Wo) of the dried specimen and immersing the dried specimen in distilled water at room temperature for 10 days, the weight (W) of the specimen was measured to determine the water absorption rate (Wab = (W-Wo) / Wo × 100;%) Was calculated.

(2) yellowing test

10 g of the powder prepared in Examples and Comparative Examples was quantified in an aluminum bowl, and the degree of yellowing was observed visually for 5 minutes, 10 minutes, and 20 minutes in an electric furnace heated to 300 ° C.

Phase: ▣ (no change in color)

Medium: ◁ (slightly changes color)

Bottom: ■ (color changes to dark brown)

(3) Light diffusion characteristic evaluation

The light diffusing plate prepared in Experiment 1 using the powders of Examples 1 to 17 and Comparative Examples 1 to 13 was used as a haze transmittance meter (HR-100, according to JIS K 7105). It was measured using Murakami Color Research Laboratory.

(5) moire phenomenon

Using the powders of Examples 1 to 17 and Comparative Examples 1 to 13 to irradiate LED to the light diffusing plate prepared in Experimental Example 1 by separating the distance between the light source and the film about 5 cm, the surface of the diffusion film with the naked eye The moiré phenomenon was observed by observing.

None: Not visible to the naked eye.

Occurrence: Observed visually.

(6) glare

Using the powders of Examples 1 to 17 and Comparative Examples 1 to 13, the degree of glare generated when the LED light source was irradiated from the front at a distance of 5 cm on the surface of the light diffusion plate prepared in Experimental Example 1 was visually observed.

None: No visual glare

Occurrence: Glare

Severe: Severe glare

The measurement results of the physical properties obtained according to the present experimental example for each hollow powder are shown in Table 3 below.

Evaluation of Properties of Hollow Composite Shells and Solid Particles Yellowing
Test Light rays
Transmittance (Tt) Light diffusivity
(Haze) Moire
phenomenon Glare moisture
Absorption rate (%) Example 1 ▣ 90 89 none none 0.27 Example 2 ▣ 90 92 none none 0.24 Example 3 ▣ 90 91 none none 0.24 Example 4 ▣ 90 94 none none 0.24 Example 5 ▣ 91 92 none none 0.24 Example 6 ▣ 92 93 none none 0.24 Example 7 ▣ 91 94 none none 0.177 Example 8 ▣ 91 93 none none 0.165 Example 9 ▣ 92 92 none none 0.19 Example 10 ▣ 91 92 none none 0.17 Example 11 ▣ 92 92 none none 0.185 Example 12 ▣ 92 90 none none 0.183 Example 13 ▣ 90 92 none none 0.181 Example 14 ▣ 92 89 none none 0.185 Example 15 ▣ 91 90 none none 0.25 Example 16 ▣ 92 88 none none 0.18 Example 17 ▣ 91 90 none none 0.25 Comparative Example 1 ▣ 89 85 none Occur 0.54 Comparative Example 2 ▣ 85 56 none Occur 0.95 Comparative Example 3 ▣ 85 20 Occur Occur 1.05 Comparative Example 4 ▣ 85 25 Occur Occur 1.12 Comparative Example 5 ▣ 84 20 Occur Occur 1.10 Comparative Example 6 ▣ 92 15 Occur Occur 1.12 Comparative Example 7 ▣ 89 85 none none 0.17 Comparative Example 8 ▣ 93 90 none none 0.50 Comparative Example 9 ▣ 86 67 Occur Occur 0.25 Comparative Example 10 ■ 85 65 Occur Occur 0.50 Comparative Example 11 ◁ 89 15 Occur Severe 1.27 Comparative Example 12 ◁ 87 67 none Occur 1.25 Comparative Example 13 ◁ 82 70 none Occur 1.20

In the above, the present invention has been described in detail based on the preferred embodiments of the present invention, but the present invention is by no means limited to these examples. Those skilled in the art will be able to easily devise various modifications and changes based on the embodiments described above. However, it will be apparent from the appended claims that such variations and modifications fall within the scope of the present invention.

Claims (23)

Magnesium fluoride is a hollow composite doped with silica, represented by the following formula (1), the hollow composite having an average particle diameter of 100 nm ~ 10.0 ㎛.
Formula 1
(MgF ₂ ) _(a) (SiO ₂ ) _(1-a))
(In Formula 1, a is a weight ratio of magnesium fluoride doped to silica and ranges from a = 0.005 to 0.25) The hollow composite of claim 1, wherein the hollow composite has a plate shape, an elliptical shape, or a convex lens shape. delete The hollow composite of claim 1, wherein the hollow composite has an average thickness of 30 to 1000 nm. The hollow composite of claim 1, wherein the hollow composite has an average aspect ratio (long diameter / thickness) in a range of 1.2 to 10. The hollow composite of claim 1, wherein the shell thickness of the hollow composite is 5 to 100 nm. As a manufacturing method of the hollow composite of Claim 1,
Preparing a composite sol of magnesium fluoride doped silica;
Reacting the composite sol of silica-doped silica with inorganic particles to form a core-shell structured particle composed of a shell of magnesium-fluoride-doped silica and an inorganic core;
Removing the inorganic core from the formed core-shell structured particles to form a hollow composite of magnesium fluoride-doped silica. The method of claim 7, further comprising surface-treating the surface of the hollow composite using a fluorine-based organic material or a silane coupling agent. 8. The method of claim 7, wherein the inorganic particles are hydrotalcites represented by the following Chemical Formula 2.
(2)
M ²⁺ _1-x M ³⁺ _x (OH) ₂ (A ^n- ) _{x / n} ? MH ₂ O
In Formula 2, M ²⁺ and M ³⁺ are mixed metal components forming the center of the positive charge layer, respectively, M ²⁺ is Mg ²⁺ , Ca ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Mn ^Is a metal component which may have an oxidation number of +2 selected from the group consisting of ²⁺ and Zn ²⁺ , and M ³⁺ is selected from the group consisting of Al ³⁺ , Fe ³⁺ , Ga ³⁺ and Y ³⁺ (OH) is a component constituting the upper and lower sides of the mixed metal component, and A ^n- is an interlayer anion having a valence of n and can be exchanged with other anions. as the ^{_{anions, CO 3 2-, NO 3-,}} SO 4 2-, OH -, F -, Cl -, Br - and silicon (Si) - anion-containing oxyacids, the (P) - containing anionic oxygen acids, boron ( B) -containing oxygen acid anions, where x is a fraction of the M ²⁺ component and the M ³⁺ component, in the range of 0.20 ≦ x ≦ 0.50 and in the range of 0 ≦ m <1) 8. The method of claim 7, wherein the inorganic particles are hydrotalcites represented by the following general formula (3).
(3)
M ²⁺ _1-x M ³⁺ _x (OH) _2-y O _y (A ^n- ) _{x / n} ? MH ₂ O
In Formula 3, M ²⁺ and M ³⁺ are mixed metal components forming the center of the positively charged layer, respectively, and M ²⁺ represents Mg ²⁺ , Ca ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , and Mn. ^Is a metal component which may have an oxidation number of +2 selected from the group consisting of ²⁺ and Zn ²⁺ , and M ³⁺ is selected from the group consisting of Al ³⁺ , Fe ³⁺ , Ga ³⁺ and Y ³⁺ (OH) is a component constituting the upper and lower sides of the mixed metal component, and A ^n- is an interlayer anion having a valence of n and can be exchanged with other anions. as the ^{_{anions, CO 3 2-, NO 3-,}} SO 4 2-, OH -, F -, Cl -, Br -, silicon (Si) containing SiO ₃ ^2- - oxyacids contain an anion, PO ₄ ^3- phosphorus (P) containing-containing oxygen acids anions, BO ₃ ^2-, boron (B) comprising a - is selected from the group consisting of oxygen acids containing ^{_{anions, CrO 4 2-, CrO 7 2-}} x is M ^{2+ Fraction of the} component and M ³⁺ component, 0.20 ≦ x ≦ 0 In the range .36, in the range 0 <y ≤ 1, and in the range 0 ≤ m <1) 8. The method of claim 7, wherein the inorganic particles are hydrotalcites represented by the following general formula (4).
Formula 4
M ²⁺ _1-x M ³⁺ _x (OH) ₂ (A ^n- ) _{x / n}
In Formula 4, M ²⁺ and M ³⁺ are mixed metal components forming the center of the positively charged layer, respectively, M ²⁺ is Mg ²⁺ , Ca ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , and Mn ^{2. Is} a metal component which may have an oxidation number of +2 selected from the group consisting of ⁺ and Zn ²⁺ , and M ³⁺ is selected from the group consisting of Al ³⁺ , Fe ³⁺ , Ga ³⁺ and Y ³⁺ (OH) is a component constituting the upper and lower sides of the mixed metal component, and A ^n- is an interlayer anion having a valence of n, and ⁿ is interchangeable with other anions. As an anion, a silicon (Si) -containing oxygen acid anion, PO ₄ ^3- , comprising CO ₃ ^2- , NO ^3- , SO ₄ ^2- , OH ⁻ , F ⁻ , Cl ⁻ , Br ⁻ , SiO ₃ ^2- Phosphorus (P) -containing oxyacid anion, including boron (B) -containing oxyacid anion, including BO ₃ ^2- , CrO ₄ ^2- , CrO ₇ ^2- , x is an M ²⁺ component And the fraction of M ³⁺ component, 0.20 ≦ x ≦ 0. Range of 36) 10. The method of claim 9, wherein the hydrotalcite used as the core is heat-treated at a temperature in the range of 500 to 700 ° C., and a hydrotalcite having a form in which an interlayer anion is removed is used. The method of claim 7, wherein the inorganic particles are soluble in the range of pH 0.5 to 3.0, and the method of producing a hollow composite, characterized in that the inorganic substance in the form of a plate, sphere or ellipse. The light-diffusion agent in which the hollow composite_body | complex in any one of Claims 1, 2, and 4-6 is disperse | distributed in resin. The light diffusing agent according to claim 14, wherein the hollow composite is dispersed in a range of 0.001 to 200 parts by weight based on 100 parts by weight of the resin. 15. The light diffusing agent according to claim 14, wherein the light diffusing agent is a liquid or a solid in a pellet form. The light diffusing structure according to claim 14, wherein the light diffusing agent is mixed with the substrate, or the light diffusing agent is laminated or coated on the substrate. 18. The light diffusing structure of claim 17 wherein the substrate is in the form of a film or sheet. The light diffusing structure of claim 17, wherein the light diffusing structure is in the form of an LED lampshade, a bulb, or a tube. 18. The light diffusing structure of claim 17 wherein the light diffusing structure is used for LED chip or LED packaging. The light diffusing structure according to claim 17, wherein the substrate is a substrate which is a light diffusing film or sheet for an organic light emitting diode (OLED). The light diffusing agent described in claim 14 or the light diffusing agent is mixed with the substrate or the light diffusing agent is laminated or applied on the surface of the substrate, the linear light source or point light source is implemented as a surface light source Cotton light emitting device. 23. The surface light emitting device of claim 22, wherein the surface light emitting device comprises a backlight unit assembly or an LED package of a liquid crystal display device (LCD).

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