KR20110016064A - Sky blue colored zirconia ceramics and method for fabricating the same - Google Patents

Abstract

PURPOSE: A method for preparing sky-blue zirconia ceramics is provided to express stable sky blue color effect without physical/chemical characteristic change. CONSTITUTION: A method for preparing sky-blue zirconia ceramics comprises: a step of mixing synthesized material containing covalt oxide(CoO), zinc oxide(ZnO), and aluminium hydroxide(Al(OH)_3) to zircon oxide(ZrO_2) to obtain a mixture; a step of adding 20-50 weight% of moisture; a step of granulating to obtain a molded powder; and a step of plasticizing the molded powder.

Description

Sky blue colored zirconia ceramics and method for fabricating the same}

The present invention relates to sky blue zirconia ceramics and a method for manufacturing the same, and more particularly, various conditions (eg, zirconium oxide (ZrO ₂ ), cobalt oxide (CoO), zinc oxide () for inducing sky blue color development of zirconia ceramics. ZnO), mixing conditions of aluminum hydroxide (Al (OH) ₃ ), etc., mixing conditions of water, particle size conditions of zirconium oxide (ZrO ₂ ) powder, mixing conditions of dispersant, binder, release agent, etc., firing temperature conditions, etc.) The present invention relates to a sky blue zirconia ceramics and a method of manufacturing the same, which can flexibly exhibit a stable sky blue color development effect without changing physical or chemical properties even if the high temperature firing is performed at 1400 ° C. or higher.

In general, zirconia ceramics have excellent mechanical properties such as strength, hardness, and tensile strength, and have been mainly used as structural materials for mechanical components. Recently, colored zirconia ceramics, which can express various colors, is newly introduced. It has been developed, for example, to expand the range of applications to various jewelry, decorative parts, such as watch cases, watch bands, tie pins and the like.

Of course, in order to extend the scope of zirconia ceramics to various jewelry and decorative parts, the producers have many excellent physical / zirconia ceramics even in the firing process at high temperature (for example, 1400 ° C or higher). Not only the chemical properties but also the color of the pigment imparted to the zirconia ceramics bears the burden of maintaining it evenly.

However, since most of the pigments applied to zirconia ceramics are low-temperature pigments that can achieve stable color development only at low firing temperatures of 1300 ° C. or lower, when applied to zirconia ceramics that must undergo high temperature firing procedures of 1400 ° C. or higher, There is a serious problem that the color changes during the firing procedure.

Of course, in this situation, the producer side cannot acquire zirconia ceramics of a satisfactory color (for example, a satisfactory sky blue color) at all, and, eventually, have a great difficulty in commercializing it as a decorative part or the like.

Accordingly, an object of the present invention is to provide a variety of conditions (eg, zirconium oxide (ZrO ₂ ), cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ) for inducing sky blue color development of zirconia ceramics. Such as mixing conditions, moisture mixing conditions, zirconium oxide (ZrO ₂ ) powder particle size conditions, dispersing agents, binders, release conditions, such as mixing conditions, sintering temperature conditions, etc.), by providing a high temperature baking of 1400 ℃ or more Even in the present invention, there is provided a zirconia ceramics that can flexibly exhibit a stable sky blue color development effect without any physical or chemical property change.

Other objects of the present invention will become more apparent from the following detailed description and the accompanying drawings.

In order to achieve the above object, in the present invention, a mixture of zirconium oxide (ZrO ₂ ) and cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ) are mixed to prepare a mixture. To prepare a molded powder by adding water corresponding to 20% to 50% by weight of the total amount of the mixture, and then granulating the mixture, preparing a molded body from the molded powder, and firing the molded body. Disclosed is a manufacturing method of light blue zirconia ceramics, which comprises:

In this case, preferably, the zirconium oxide (ZrO ₂ ) is a zirconium oxide powder having an average particle size of 0.3 ㎛ to 0.8 ㎛, the cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) The composite consisting of ₃ ) is added in an amount of 1 to 10 parts by weight based on 100 parts by weight of zirconium oxide (ZrO ₂ ).

Here, preferably, in the preparing of the mixture, a dispersant or a binder is further added to the mixture, in which case the dispersant or binder is 0.1 parts by weight to 10 parts by weight, respectively, based on 100 parts by weight of the zirconium oxide (ZrO ₂ ). The weight part is added.

At this time, the step of preparing the molded powder is added to the mixture of the water corresponding to 20% to 50% by weight of the total amount of the mixture, the granules so that the average particle size of the mixture is 40㎛ to 120㎛ It is made of a process for forming a molded powder, in the step of firing the molded body, the firing temperature is maintained at 1400 ℃ to 1600 ℃.

Based on the various production methods described above, another aspect of the present invention discloses light blue zirconia ceramics.

In the present invention, a mixture of various conditions (eg, zirconium oxide (ZrO ₂ ), cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ), or the like for inducing sky blue color development of zirconia ceramics Conditions, mixing conditions of water, particle size conditions of zirconium oxide (ZrO ₂ ) powder, mixing conditions of dispersing agents, binders, release agents and the like, firing temperature conditions, etc.), so that the producer side 1400 under the implementation environment of the present invention. Even if high-temperature firing is performed at or above ℃, zirconia ceramics that can flexibly exhibit stable light blue color development effect can be effectively manufactured and provided to the consumer without any physical or chemical property change.

Sky blue zirconia ceramics manufacturing method according to the present invention is large, zirconium oxide (ZrO ₂ ) to a mixture of cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ) to prepare a mixture Step, adding water corresponding to 20% to 50% by weight of the total amount of the mixture to the mixture, and then granulating to prepare a molded powder, to prepare a molded body from the molded powder, and to fire the molded body Including the steps.

First, in the present invention, a compound composed of cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ) is mixed with zirconium oxide (ZrO ₂ ). Zirconium oxide (ZrO ₂ ), cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ), etc. used in the present invention is not particularly limited, any commercially available can be used. Do.

The zirconium oxide (ZrO ₂ ) is preferably a zirconium oxide powder having an average particle size of 0.3 to 0.8㎛. If the average particle size of the zirconium oxide (ZrO ₂ ) is less than 0.3㎛ may cause a large shrinkage during firing, if it exceeds 0.8㎛ may cause a problem that the sintering is not made well and the plastic color worsens.

The composite consisting of cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ) may be preferably added in an amount of 1 part by weight to 10 parts by weight based on 100 parts by weight of zirconium oxide (ZrO ₂ ). have.

When the compound consisting of the cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ) is added less than 1 part by weight, there may occur a problem that the light blue effect is not fully exhibited, 10 weight In the case where the amount is exceeded, the color may become cloudy and the physical properties of the zirconia may be deteriorated.

The zirconium oxide (ZrO ₂ ) is mixed with a composite made of cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ), in the present invention, the zirconium oxide (ZrO ₂ ) and cobalt oxide At least one of a dispersant or a binder may be further added to a mixture of (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ).

The dispersant thus added serves to evenly distribute the solids (powder) in the ceramic composition. In the present invention, any dispersant known in the art may be used without limitation. Specific examples include soda-based dispersants and acrylic dispersants, but are not necessarily limited thereto.

At this time, the dispersant is preferably included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of zirconium oxide (ZrO ₂ ). If the content of the dispersant is less than 0.1 parts by weight, the effect of dispersant addition may be insignificant, and if it exceeds 10 parts by weight, the remaining ash after firing may affect the properties and the color.

The binder serves to bind each component in the ceramic composition well. In the present invention, any dispersant known in the art may be used without limitation. Specific examples include silica sol, polyvinylalcohol (PVA), kaolin, and the like, but are not necessarily limited thereto.

The binder is preferably included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of zirconium oxide (ZrO ₂ ). When the content of the binder is less than 0.1 parts by weight or more than 10 parts by weight, the physical properties of the molded body may be deteriorated.

In addition, in addition to the dispersing agent and the binder, the release agent may be further added in order to facilitate the press. Specific examples of such release agents include diethylene glycol monostearate, hydrogenated castor oil, stearic acid, oleic acid, isophthalic acid, and adipic acid. adipic acid, zinc stearate, calcium stearate, ethylene bis (stearamide), oleyl palmitamide, microcrystalline wax waxes, paraffin wax, carnauba wax, spermaceti wax, cellophane, cellulose acetate, sodium alginate; Polydimethylsiloxane, polyalkylmethylsiloxane, polytetrafluorolorreethylene, poly (fluoroacrylates), poly (fluoroethers) )), Polyethylene, polypropylene, poly (vinylalcohol), synthetic polymers such as talc, kaolin, mica, silica, etc. Of the inorganic materials of the selected species or more may be selected, of course, it is not necessarily limited thereto. Especially in this invention, HS LUB A350 (brand name) or NOPCO LU 6418 (brand name) of a newly emerging material company (Korea) can be used.

Meanwhile, as described above, in the present invention, a mixture of zirconium oxide (ZrO ₂ ) and cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ), and optionally a dispersant and / or binder Optionally, a procedure of mixing and adding a release agent is performed, followed by adding and granulating water to the mixture to prepare and prepare a molded powder.

The moisture is a mixture of the mixture (ie, zirconium oxide (ZrO ₂ ) and cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ), dispersant and / or binder, and optionally a release agent. May be added in an amount of 20% to 50% by weight of the total amount).

At this time, when the moisture content is less than 20% by weight may cause a problem that the spray is not made well, when the water content exceeds 50% by weight when the granules are made in the shape of a balloon when making granules after water spraying Such problems may occur that granules are not formed properly. The wet mixing mentioned above can be carried out by methods well known in the art.

In the embodiment of the present invention, the water addition and granulation of the mixture was carried out using a spray dryer, which is just one example, and the preparation / preparation of the granulation and molding powder of the present invention is performed only by this method. It is not limited.

In the present invention, during the granulation process, spherical particles having an average particle size of 40 to 120 μm constituting the mixture can be obtained as a molding powder.

At this time, when the average particle size of the molded powder is less than 40㎛ or more than 120㎛, there may be a difficulty in manufacturing the molded body. In addition, if the size of the granules is less than 40㎛, the granules are scattered during molding may cause a problem of difficult density control. If the size of the granules is larger than 120㎛, due to the cavitation phenomena made in the granules there are a lot of bubbles after molding may result in poor physical properties.

In this way, after the production / preparation of the molded powder, a step of manufacturing and firing the molded product from the molded powder proceeds. In the production of such a molded body, it is possible to make a molded body in various shapes, for example, square, rectangular or circular, and a molding method well known in the art may be used. In the embodiment of the present invention, the dry uniaxial molding method was used, but the molding method of the present invention is not necessarily limited thereto.

In this case, the above-described firing temperature may be preferably 1400 ° C to 1600 ° C.

The firing temperature is adjustable according to the size of the molded body, which may be usually 1 hour to 20 hours, but is not necessarily limited thereto. Small component crisis may be used both oxidizing and reducing firing.

As described in the above-described prior art description, in general, when zirconia ceramics are fired at a high temperature of 1400 ° C. or higher, the pigment used for color development burns out, and thus the desired color development effect cannot be exhibited.

However, the sky blue zirconia ceramics according to the present invention has the effect that the sky blue appears well even at a high temperature of more than 1400 ℃. In the present invention, in the manufacture of light blue zirconia ceramics, the conditions for light blue color development (eg, zirconium oxide (ZrO ₂ ), cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ) and the like This is because the mixing conditions, the mixing conditions of water, the particle size conditions of the zirconium oxide (ZrO ₂ ) powder, the mixing conditions of the dispersing agent, the binder, the release agent, and the calcination temperature conditions) are optimized.

At this time, when the above-described firing temperature is less than 1400 ℃ sintering may not be made well, when the firing temperature is 1600 ℃ or more occurs the volume expansion of zirconia, poor physical properties or poor color of the light blue color This can happen.

The sky blue zirconia ceramics produced according to the production method of the present invention stably display the sky blue even at a high temperature of 1400 ° C. or higher and maintain the excellent physical properties of zirconia. Therefore, sky blue zirconia ceramics according to the present invention can be used in various ways, such as jewelry, decorative products or household goods while meeting the demand for the sky blue desired by the consumer.

Hereinafter, the sky blue zirconia ceramics according to the present invention will be described in more detail with reference to the following Examples and Test Examples. However, these Examples and Test Examples are for illustrating the present invention and the scope of the present invention is not limited thereto.

Example

Example 1

As shown in Table 1 below, in the present invention, 100 g of zirconia (Daiji, Japan) having an average particle size of 0.5 μm and cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ) After mixing 5g of the composite consisting of a ball mill together, using a spray dryer (drying capacity 15L / hr) was added water corresponding to 40% by weight of the total amount of the mixture and granulation was carried out.

At this time, the temperature inside the spray drying chamber was 180 ° C., and a molding powder having an average particle size of 60 μm was obtained at a rotational speed of the disk in the sprayer at 10000 rpm. The molded powder was molded by dry compression molding using a rod mold of 40 × 6 × 5 mm, calcined for 1 hour in an electric furnace at 1500 ° C., and then cooled naturally to obtain light blue zirconia ceramics.

Furtherance Granulation condition Molding conditions Firing conditions mixture moisture Spray
Inside the drying room
Temperature Atomizer disc rotation
speed Mold Molding
Way Firing
Temperature Firing
time Zirconia composite 100 g 5 g 105g 40
weight% 180 DEG C 10000
rpm Stick mold compression
Pressure forming method 1500 ℃ 1 hours

Example 2

As shown in Table 2 below, a composite composed of 100 g of zirconia (Daiji, Japan) having an average particle size of 0.5 μm, cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ). A light blue zirconia ceramics was obtained in the same manner as in Example 1 except that 5 g, a soda-based dispersant (44CF, Emerging Materials, Korea) 1g, and 5 g of PVA 215 were obtained.

Furtherance Granulation condition Molding conditions Firing conditions mixture moisture Spray
Inside the drying room
Temperature Atomizer disc rotation
speed Mold Molding
Way Firing
Temperature Firing
time Zirconia composite minute
mountain
My PVA
215 100 g 5 g 1 g 5 g 111g 40
weight% 180 DEG C 10000
rpm Stick mold compression
Pressure forming method 1500 ℃ 1 hours

Example 3

As shown in Table 3 below, a composite composed of 100 g of zirconia (Daiji, Japan) having an average particle size of 0.5 μm, cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ). 5 g, a soda-based dispersant (44CF, Emerging Materials, Korea) 1g, PVA 215 5g, and was carried out in the same manner as in Example 2 except for using a mold for bracelet straps to prepare a bracelet ornament using light blue zirconia ceramics. (See Figure 1).

Furtherance Granulation condition Molding conditions Firing conditions mixture moisture Spray
Inside the drying room
Temperature Atomizer disc rotation
speed Mold Molding
Way Firing
Temperature Firing
time Zirconia composite minute
mountain
My PVA
215 100 g 5 g 1 g 5 g 111g 40
weight% 180 DEG C 10000
rpm Bracelet Mold compression
Pressure forming method 1500 ℃ 1 hours

Test Example

Test Example 1: Color Analysis of Ceramics

The color analysis of the light blue zirconia ceramics obtained in Examples 1 and 2 is an ultraviolet-visible spectrophotometer (UV-2401PC, Shimatsu, Japan), and the value of the CIE (Commissiom Internationalede I'Eclairage) color system ( L *, a *, b *) and the results are shown in Table 4.

Example L * a * b * One 60.84 15.30 -36.01 2 63.15 14.75 -32.78

As shown in Table 4, in the light blue zirconia ceramics obtained in Examples 1 and 2, the brightness was about 60.84 or 63.15, and the saturation was a *: 15.30 or 14.75, b *:- 36.01 or -32.78 indicates that sky blue was expressed.

Test Example 2: Physical property analysis

The light blue zirconia ceramic specimens of Examples 1 and 2 and the comparative examples, the strength, the bending strength and the water absorption of commercially available zirconia (KZ-3YF, Kyoritsu, Japan) were measured by the following method It is shown in Table 5.

-Strength measurement: Universal testing machine (EZ test, Shimatsu, Japan)

-Absorption rate: KS L 3114

burglar Absorption rate Example 1 910 0.00% Example 2 904 0.00% Comparative example 896 0.09%

As can be seen from the results of Table 5, it can be seen that the light blue zirconia ceramics according to the present invention maintain the excellent physical properties of the existing zirconia. Therefore, sky blue zirconia ceramics according to the present invention can be flexibly applied to jewelry or decorative products.

While specific embodiments of the invention have been described and illustrated above, it will be apparent that the invention may be embodied in various modifications by those skilled in the art. Such modified embodiments should not be understood individually from the technical spirit or point of view of the present invention and such modified embodiments should fall within the scope of the appended claims of the present invention.

1 is a photograph showing the bracelet ornaments using sky blue zirconia ceramics according to an embodiment of the present invention.

Claims (8)

Preparing a mixture by mixing a zirconium oxide (ZrO ₂ ) with a composite made of cobalt oxide (CoO), zinc oxide (ZnO), and aluminum hydroxide (Al (OH) ₃ ); Adding water corresponding to 20% to 50% by weight of the total amount of the mixture to the mixture, and then granulating to prepare a molded powder; A method of manufacturing a light blue zirconia ceramics, comprising the steps of preparing a molded body with the molded powder and firing the molded body. The method of claim 1, wherein the zirconium oxide (ZrO ₂ ) is a zirconium oxide powder having an average particle size of 0.3 μm to 0.8 μm. According to claim 1, wherein the composite consisting of cobalt oxide (CoO), zinc oxide (ZnO), aluminum hydroxide (Al (OH) ₃ ) is 1 part by weight to 10 parts by weight based on 100 parts by weight of zirconium oxide (ZrO ₂ ). Method for producing a light blue zirconia ceramics, characterized in that it is added. The method of claim 1, wherein in the preparing of the mixture, a dispersant or a binder is further added to the mixture. The method of claim 4, wherein the dispersing agent or the binder is 0.1 to 10 parts by weight based on 100 parts by weight of the zirconium oxide (ZrO ₂ ), respectively. The method of claim 1, wherein the preparing the powder comprises adding water corresponding to 20 wt% to 50 wt% of the total amount of the mixture to the mixture, and then the average particle size of the mixture is 40 μm to 120 A method for producing a light blue zirconia ceramics, characterized in that it comprises a process for producing a molded powder by granulating to a ㎛. The method of claim 1, wherein in the step of firing the molded body, the firing temperature is 1400 ℃ to 1600 ℃. Light blue zirconia ceramics prepared according to the method of any one of claims 1 to 7.

Images