KR102433155B1 - Slurry composite containing zirconia with high transmittance and strength, Preparation method thereof, and Ceramic structure using the same - Google Patents

Abstract

The present invention is capable of manufacturing a zirconia ceramic structure using 3D printing technology, and relates to a slurry composition comprising zirconia, a photocurable monomer, a diluent and a dispersant, a manufacturing method thereof, a ceramic structure using the same, and a method of manufacturing a ceramic structure. , The slurry composition exhibits very little light scattering and has very excellent shape realization ability, so that a zirconia ceramic structure with a very complex shape can be simply manufactured using 3D printing technology, and wasteful waste processes can be reduced. In addition, the manufactured ceramic structure is not broken during operation due to its high strength, and it is possible to modify the shape and surface with a dental grinding machine, etc., so that it has excellent processability.

Description

Slurry composition containing zirconia of high light transmittance and high strength, a manufacturing method thereof, and a ceramic structure using the same

The present invention relates to a slurry composition capable of manufacturing a zirconia ceramic structure using 3D printing technology, and comprising zirconia, a photocurable monomer, a diluent and a dispersant, a method for preparing the same, a ceramic structure using the same, and a method for manufacturing the ceramic structure .

Recently, research on the development of 3D printing technology for patient-tailored medical materials that can manufacture a three-dimensional shape that considers individual characteristics of each patient is attracting attention worldwide. Unlike the existing technology of manufacturing artificial bones and teeth customized for the patient through a cutting process based on a material of a fixed shape, it can have a three-dimensional shape that accurately reproduces the part that the patient needs treatment, so it has a complex shape. In addition to being applicable to the case, it is possible to manufacture a shape at a faster speed while reducing material loss than before.

Various 3D printing technologies that can manufacture ceramic structures have been developed so far. In particular, in the case of the tape-casting method-based photocurable 3D printing technology used in the present invention, starting with the targeted ceramic powder, a photocuring agent is included. The liquid slurry mixed with the monomer-diluent-dispersant mixture is selectively cured one layer at a time to the desired shape and thickness using light such as UV light and stacked to form very complex structures at a faster rate. There are strengths.

The properties required for artificial teeth used in living organisms include high physical properties, human-imitation esthetics, and good biocompatibility. For this purpose, gold, titanium, and zirconia are widely used materials. Gold, titanium, etc., which have been widely used in the past, showed excellent performance in terms of physical properties and biocompatibility. The demand for zirconia artificial teeth that can be replaced is increasing.

Republic of Korea Patent Publication No. 10-2017-0122100 Republic of Korea Patent Publication No. 10-2018-0116776

An object of the present invention is to optimize the content of a photocurable monomer, diluent, dispersant, and photocuring initiator to provide a slurry composition in which zirconia is very uniformly dispersed with a high zirconia content and adequate flowability (viscosity), the slurry composition To provide a ceramic structure having high light transmittance and high strength through a tape-casting method-based photocurable 3D printing technology using

The present invention comprises a zirconia powder, a photocurable monomer, a diluent and a dispersant,

The zirconia powder provides a slurry composition comprising 1% to 60% by volume based on the total composition.

In addition, the present invention comprises the steps of calcining the zirconia powder and pulverizing it using a ball mill;

preparing a mixture by mixing a photocurable monomer, a diluent and a dispersant;

Dispersing the zirconia powder that has undergone the grinding step in the mixture,

The zirconia powder provides a method for preparing a slurry composition, characterized in that it is dispersed in an amount of 1% to 60% by volume relative to the total composition.

In addition, the present invention provides a ceramic structure using the above-described slurry composition.

In addition, the present invention comprises the steps of applying the above-described slurry composition with a blade so that the thickness is 25 to 200㎛;

photo-curing the applied slurry composition by irradiating light to form a ceramic film;

forming a ceramic molded body by repeatedly performing the steps of applying with the blade and forming a ceramic film; and

It provides a method of manufacturing a ceramic structure comprising the step of manufacturing a ceramic structure by heat-treating the ceramic compact.

The present invention is a slurry composition having a fluidity suitable for 3D printing technology, including a high content of zirconia and an optimized content of photocurable monomers, diluents and dispersants. It is very good, and using 3D printing technology, it is possible to simply manufacture a zirconia ceramic structure with a very complex shape, and it is possible to reduce the wasteful process. In addition, the manufactured ceramic structure has high strength and is not broken during operation, and has excellent processability because the shape and surface can be modified with a dental grinding machine or the like.

1 is an image taken with a scanning electron microscope (SEM) of a zirconia powder according to an embodiment: (a) is an image of a commercially obtained zirconia powder, (b) is a calcination and ball mill process in the embodiment It is an image of zirconia powder, (c) is an image of a slurry obtained by dispersing commercially obtained zirconia powder in a monomer, and (d) is a slurry obtained by dispersing a zirconia powder that has been calcined and ball milled in the example in a monomer. It is a photographed image.
2 is an image (a) when a certain amount of a dispersant is added to a slurry composition according to an embodiment and a graph showing a viscosity value according to a shear rate of the slurry composition according to an embodiment.
3 is a photograph of a three-dimensional ceramic structure prepared by using a 3D printing technology of a slurry composition according to the present invention.
4 is a schematic image of a method for manufacturing a ceramic structure according to the present invention.
5 is an image taken of a blade for manufacturing a ceramic structure according to the present invention and a method of manufacturing the ceramic structure.
6 is an image taken with a scanning electron microscope (SEM) of the ceramic structure according to the present invention: (a) is an image of the surface of the ceramic structure before sintering, (b) is the surface of the ceramic structure after sintering is one image.
7 is an image taken with a scanning electron microscope (SEM) of the fracture surface of the ceramic structure according to the present invention.
8 is a result of measuring the light transmittance of the slurry composition and the ceramic structure according to the present invention: (a) is a photograph observed by placing a circular sample formed from the slurry composition prepared in Example 5 on a letter, ( b) is a photograph observed by placing a circular sample formed from the slurry composition prepared in Example 5 on the image, and (c) is a photograph observed by placing the tooth-shaped ceramic structure prepared in Example 13 on the image. It's a photo.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and it should be understood that all modifications, equivalents and substitutes included in the spirit and scope of the present invention are included.

The present invention comprises a zirconia powder, a photocurable monomer, a diluent and a dispersant,

The zirconia powder provides a slurry composition comprising 1% to 60% by volume based on the total composition.

As an example, the zirconia powder may not include a binder. In general, commercially available zirconia powder contains a binder on the surface, but in this case, it is difficult to use for 3D printing due to light reflection. On the other hand, the zirconia powder has been calcined and does not contain a binder, so there is no problem such as light reflection, and it has excellent dispersibility with a photocurable monomer, so that it can be used for 3D printing.

Specifically, the zirconia powder may be included in an amount of 1% by volume to 60% by volume based on the total composition. More specifically, the zirconia powder is 10% by volume to 60% by volume, 10% by volume to 55% by volume, 30% by volume to 60% by volume, 30% by volume to 55% by volume, 40% by volume to 60% by volume based on the total composition Volume %, 40% to 55% by volume, 45% to 60% by volume, 45% to 55% by volume, 50% to 60% by volume or 50% to 55% by volume.

In addition, the zirconia powder may be included in an amount of 80 wt% to 95 wt% based on the total composition. Specifically, the zirconia powder may include 80% to 95% by weight, 80% to 90% by weight, 85% to 95% by weight, or 85% to 90% by weight based on the total composition.

The slurry composition according to the present invention may contain the zirconia powder in a high content as described above by including the zirconia powder without a binder.

As an example, the photocurable monomer and the diluent may be included in a weight ratio of 6:4 to 9:1. Specifically, the photocurable monomer and diluent may be 6:4 to 9:1, 6.5:3.5 to 9:1, 6:4 to 8:2, or 6.5:3.5 to 7.5:2.5.

For example, the photocurable monomer may be included in an amount of 6 wt% to 10 wt% based on the total composition, and the diluent may be included in an amount of 2 wt% to 6 wt% based on the total composition. Specifically, the photocurable monomer includes 6% to 9% by weight, 7% to 10% by weight, or 7% to 9% by weight based on the total composition, and the diluent is 2% to 5% by weight based on the total composition , 3% to 6% by weight or 3% to 5% by weight may be included.

The photocurable monomer may be at least one selected from the group consisting of 1,6 Hexanediol diacrylate (HDDA), Triethylene glycol dimethacrylate (TEGDMA), Trimethylolpropane triacrylate (TMPTA), Isodecyl acrylate (IDA), and Isobornyl acrylate (IBA). Specifically, the photocurable monomer may be 1,6 Hexanediol diacrylate (HDDA), Triethylene glycol dimethacrylate (TEGDMA), Trimethylolpropane triacrylate (TMPTA), Isodecyl acrylate (IDA), or Isobornyl acrylate (IBA). In this case, isodecyl acrylate (IDA) or isobornyl acrylate (IBA) may serve as a diluent.

In addition, the diluent may be at least one selected from the group consisting of Decahydronaphthalene (DECALIN) and 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one (Camphor). Specifically, the diluent may be Decahydronaphthalene (DECALIN) or 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one (Camphor).

As an example, the dispersant is CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-190, BYK-2001, BYK-2012, BYK-2013 and Anti-Terra-U. It may be at least one selected from the group consisting of. Specifically, the dispersant may be CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-190, BYK-2001, BYK-2012, BYK-2013 or Anti-Terra-U. .

More specifically, in the dispersant, CC-9 is VARIQUAT's polypropylene oxide quaternary ammonium chloride, and KD-4 is Croda's 12-Hydroxy octadecanoic acid homopolymer octadecanoate (CAS:58128-22-6) Anti-Terra-U contains acidic polyester polymers, BYK-111 contains copolymers containing acidic groups, and BYK-163, BYK-190, BYK-2012 and BYK-2013 contain pigment affinity groups. BYK-180 includes an alkylol ammonium salt of a copolymer containing an acidic group, BYK-2001 includes an acrylate block copolymer.

For example, the type of the dispersant may have a composition as shown in Table 1 below.

Chemical Names and Common Names CAS number content(%) Anti-Terra-U
(BYK-Chemie) Salt of long chain polyamino amides and lower molecular weight acidic polyesters trade secret 50.5 Ethylbenzene 100-41-4 11.5 Proplyene glycol 57-55-6 4.8 Xylene 1330-20-7 28.2 Toluene 108-88-3 0.1 2-mthylpropan-1-ol;isobutanol 78-83-1 4.9 BYK-111 (BYK-Chemie) Copolymer with acidic groups trade secret 97.0 phosphoric acid 7664-38-2 3.0 BYK-163 (BYK-Chemie) High molecular weight block copolymer with pigment affinic groups trade secret 45.0 Xylene 1330-20-7 21.5 2-methoxy-1-methylethyl acetate 108-65-6 12.7 n-butyl acetate 123-86-4 11.8 Ethylbenzene 100-41-4 8.9 Toluene 108-88-3 0.1 BYK-180 (BYK-Chemie) Alkylolammonium salt of a copolymer with acidic groups trade secret 100.0 BYK-190 (BYK-Chemie) High molecular weight block copolymer with pigment affinic groups trade secret 40.0 Water 7732-18-5 60.0 BYK-2001 (BYK-Chemie) Modified acrylate block copolymer trade secret 46.0 2-methoxy-1-methylethyl acetate 108-65-6 21.0 2-butoxyethanol 111-76-2 21.0 1-methyoxy-2-propanol 107-98-2 12.0 BYK-2012 (by BYK-Chemie) 2,5-Furandione, telomere with 1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bis(benzene) and ethenylbenzene, 3-(dimethylamino)propylimide, imide with polyethylene-polypropylene glycol 2-aminopropyl Me ether, 2-[(C10-16-alkyloxy)methyl]oxirane-quaternized, benzoates(salt) - >=30-<50 BYK-2013 (BYK-Chemie) 2,5-Furandione, telomere with 1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bis(benzene) and ethenylbenzene, 3-(dimethylamino)propylimide, imide with polyethylene-polypropylene glycol 2-aminopropyl Me ether, 2-[(C10-16-alkyloxy)methyl]oxirane-quaternized, benzoates(salt) - >=50 -<=100

The dispersant may be included in an amount of 0.5 to 4% by weight relative to the zirconia powder. Specifically, the dispersant is 0.5 to 4% by weight, 0.5 to 3% by weight, 0.5 to 2.5% by weight, 0.5 to 2% by weight, 1 to 4% by weight, 1 to 3% by weight, 1 to 2.5% by weight relative to the zirconia powder Or 1 to 2% by weight may be included. By including the dispersing agent as described above, the slurry composition according to the present invention may have rheology applicable to 3D printing.

As an example, the slurry composition may further include a photocurable initiator. The photocurable initiator is not particularly limited as long as it is an initiator that is cured by irradiating light. For example, the photocurable initiator may be Phenylbis(2,4,6-trimethyl benzoylphosphine oxide) (PPO) or 2,4,6-Trimethylbenzoyldiphenylphosphine oxide (TPO).

Specifically, the photocurable initiator may be included in an amount of 0.5 wt% to 3 wt% based on the photocurable monomer. More specifically, the photocurable initiator is 0.5 wt% to 2.5 wt%, 0.5 wt% to 2 wt%, 1 wt% to 3 wt%, 1 wt% to 2.5 wt% or 1 wt% based on the photocurable monomer to 2% by weight. By including the photocurable initiator as described above, a shape by digital optical technology can be implemented using the slurry composition according to the present invention.

In addition, the present invention comprises the steps of calcining the zirconia powder and pulverizing it using a ball mill;

preparing a mixture by mixing a photocurable monomer, a diluent and a dispersant;

Dispersing the zirconia powder that has undergone the grinding step in the mixture,

The zirconia powder provides a method for preparing a slurry composition, characterized in that it is dispersed in an amount of 1% to 60% by volume relative to the total composition.

As an example, the pulverizing may be performed by calcining at a temperature of 800° C. to 1000° C. for 1 to 5 hours. Specifically, the pulverizing step is performed at a temperature of 800°C to 950°C, 800°C to 900°C, 850°C to 1000°C or 850°C to 950°C for 1 to 4 hours, 1 to 3 hours, 2 to 5 hours or 2 It can be carried out by calcining for 4 hours.

In addition, in the pulverizing step, the calcined zirconia powder may be mixed with 8 to 10 mm zirconia balls and ball milled using a ball mill for 24 hours or more. Specifically, the pulverizing step may be performed by mixing the calcined zirconia powder with the zirconia balls for at least 24 hours or at most 1 week, but from 24 hours to 50 hours, 24 hours to 40 hours, or 24 hours to 30 hours. It can be ball milled using a ball mill for a period of time.

The zirconia powder that has undergone the pulverization step as described above can be used for 3D printing because the binder is removed from the surface, there is no problem such as light reflection, and has excellent dispersibility with the photocurable monomer.

As an example, in preparing the mixture, the photocurable monomer and the diluent may be mixed in a weight ratio of 6:4 to 9:1. Specifically, the photocurable monomer and the diluent may be mixed in a weight ratio of 6:4 to 9:1, 6.5:3.5 to 9:1, 6:4 to 8:2, or 6.5:3.5 to 7.5:2.5.

For example, the photocurable monomer may be mixed in an amount of 6 wt% to 10 wt% based on the total composition, and the diluent may be mixed in an amount of 2 wt% to 6 wt% based on the total composition. Specifically, the photocurable monomer is mixed in an amount of 6% to 9% by weight, 7% to 10% by weight, or 7% to 9% by weight based on the total composition, and the diluent is 2% to 5% by weight based on the total composition , 3 wt% to 6 wt% or 3 wt% to 5 wt% may be mixed.

The photocurable monomer may be at least one selected from the group consisting of 1,6 Hexanediol diacrylate (HDDA), Triethylene glycol dimethacrylate (TEGDMA), Trimethylolpropane triacrylate (TMPTA), Isodecyl acrylate (IDA), and Isobornyl acrylate (IBA). Specifically, the photocurable monomer may be 1,6 Hexanediol diacrylate (HDDA), Triethylene glycol dimethacrylate (TEGDMA), Trimethylolpropane triacrylate (TMPTA), Isodecyl acrylate (IDA), or Isobornyl acrylate (IBA). In this case, isodecyl acrylate (IDA) or isobornyl acrylate (IBA) may serve as a diluent.

In addition, the diluent may be at least one selected from the group consisting of Decahydronaphthalene (DECALIN) and 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one (Camphor). Specifically, the diluent may be Decahydronaphthalene (DECALIN) or 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one (Camphor).

In the step of preparing the mixture, the dispersant is CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-190, BYK-2001, BYK-2012, BYK-2013 and Anti-Terra-U It may be at least one selected from the group consisting of. Specifically, the dispersant may be CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-190, BYK-2001, BYK-2012, BYK-2013 or Anti-Terra-U. .

In addition, the dispersant may be mixed in an amount of 0.5 to 4% by weight relative to the zirconia powder. Specifically, the dispersant is 0.5 to 3% by weight, 0.5 to 2.5% by weight, 0.5 to 2% by weight, 1 to 4% by weight, 1 to 3% by weight, 1 to 2.5% by weight or 1 to 2% by weight relative to the zirconia powder can be mixed with By mixing the dispersant as described above, the slurry composition according to the present invention may have rheology applicable to 3D printing.

As an example, in the dispersing of the zirconia powder, the zirconia powder may be mixed in a mixture of a photocurable monomer, a diluent and a dispersant in an amount of 1% to 60% by volume relative to the total composition. Specifically, the zirconia powder is 10% to 60% by volume, 10% to 55% by volume, 30% to 60% by volume, 30% to 55% by volume, 40% to 60% by volume, based on the total composition. %, 40% to 55%, 45% to 60%, 45% to 55%, 50% to 60% or 50% to 55% by volume.

In addition, the zirconia powder may be dispersed in the mixture in an amount of 80 wt% to 95 wt% based on the total composition. Specifically, the zirconia powder may be dispersed in the mixture in an amount of 80% to 95% by weight, 80% to 90% by weight, 85% to 95% by weight, or 85% to 90% by weight based on the total composition. .

As another example, the method may further include adding a photocuring initiator after dispersing the zirconia powder. The photocurable initiator is not particularly limited as long as it is an initiator that is cured by irradiating light. For example, the photocurable initiator may be Phenylbis(2,4,6-trimethyl benzoylphosphine oxide) (PPO) or 2,4,6-Trimethylbenzoyldiphenylphosphine oxide (TPO).

Specifically, in the step of adding the photocurable initiator, 0.5 wt% to 3 wt% of the photocurable initiator may be added based on the photocurable monomer. More specifically, the photocurable initiator is 0.5 wt% to 2.5 wt%, 0.5 wt% to 2 wt%, 1 wt% to 3 wt%, 1 wt% to 2.5 wt% or 1 wt% based on the photocurable monomer to 2% by weight. By adding the photocurable initiator as described above, a shape by digital optical technology can be implemented using the slurry composition according to the present invention.

In addition, the present invention provides a ceramic structure using the above-described slurry composition.

As shown in FIG. 3 , the ceramic structure according to the present invention is a printing result of a ceramic molded body using the slurry composition according to the present invention, and not only a simple structure but also a complex shape such as a screw or a tooth can be implemented, and light scattering occurs. I never do that. In addition, since the strength of the ceramic structure is high after light curing, it does not break during operation, and has excellent workability to the extent that the shape and surface can be modified with a dental grinding machine or the like.

As an example, a ceramic structure according to the present invention may exhibit a strength of 700 MPa or more. Specifically, the ceramic structure may exhibit a strength of 750 MPa or more, 800 MPa or more, 700 MPa to 1200 MPa, 700 MPa to 1100 MPa, 750 MPa to 1000 MPa, or 800 MPa to 950 MPa.

In addition, the ceramic structure may have a light transmittance of 1 to 45%. Specifically, the ceramic structure is 1 to 40%, 1 to 35%, 10 to 45%, 10 to 40%, 10 to 35%, 20 to 45%, 20 to 40%, 20 to 35%, 30 to 40 % or may have a transmittance of 30 to 35%. In general, when the ceramic structure is manufactured by the pressing process, the transmittance is about 45%, but when the ceramic structure is manufactured by 3D printing, the ceramic structure is highly likely to interfere with the transmittance by the interface by laminating the ceramic film. Although it is highly likely to negatively affect the light transmittance of the ceramic structure according to the present invention, a ceramic film having a high light transmittance is laminated by setting photo-curing conditions to prevent interference due to an interface to the structure to have the above light transmittance.

As an example, the ceramic structure may have an average particle size of 0.2 to 1.0 μm. Specifically, the ceramic structure may have an average particle size of 0.2 to 0.9 μm, 0.2 to 0.7 μm, 0.5 to 1.0 μm, 0.5 to 0.8 μm, or 0.6 to 0.8 μm. By having the particle size as described above, there are no defects or pores in the structure, and thus strength and light transmittance may be excellent.

In addition, the present invention comprises the steps of applying the above-described slurry composition with a blade so that the thickness is 25 to 200㎛;

photo-curing the applied slurry composition by irradiating light to form a ceramic film;

forming a ceramic molded body by repeatedly performing the steps of applying with the blade and forming a ceramic film; and

It provides a method of manufacturing a ceramic structure comprising the step of manufacturing a ceramic structure by heat-treating the ceramic compact.

As an example, in the step of applying with a blade, the form in which the slurry composition is injected may be changed from the form in which the slurry composition is injected based on the blade length direction. As shown in FIG. 4, assuming that the horizontal and vertical planes are X and Y, if the blade longitudinal direction is in the same direction as the Y axis and narrowly injected in the Y axis direction as shown in (A), a thin film is formed with a doctor blade. Even so, a ceramic film having a narrow shape in the Y-axis direction can be manufactured. In addition, since a film having a larger area is formed than in the case of (A) when the film is injected widely in the Y-axis direction as shown in (B), a ceramic film having a relatively large area can be manufactured.

For example, in the step of applying with the blade, the shape of the slurry composition applied with the blade changes depending on the shape in which the slurry composition is injected based on the blade length direction, but the standard deviation of the thickness of the applied slurry composition is 10% or less. can Specifically, the standard deviation of the thickness of the applied slurry composition may be 9% or less or 8% or less. As described above, in the method for manufacturing a ceramic structure according to the present invention, a thin film of 100 μm or less or 50 μm or less can be uniformly formed through a blade.

As an example, the forming of the ceramic film may be performed by irradiating light of 360 nm to 450 nm for 2 seconds to 60 seconds. Specifically, the step of forming the ceramic film is photocured by irradiating light of 360 nm to 450 nm for 2 seconds to 50 seconds, 2 seconds to 40 seconds, 5 seconds to 60 seconds, 5 seconds to 50 seconds, or 5 seconds to 40 seconds. can be performed.

In addition, the forming of the ceramic compact may be performed by a tape-casting method. The tape-casting method injects a slurry composition having an appropriate viscosity, forms a thin film using a doctor blade, and forms a shape by irradiating a light source on the film. manufacturing technology. By manufacturing a ceramic structure using the taping method, a ceramic structure having a complex structure such as a tooth can be precisely manufactured, and the amount of ceramic cut to manufacture an artificial tooth can be significantly reduced.

The manufacturing of the ceramic structure may be performed by sintering at a temperature of 1000°C to 2000°C. Specifically, the manufacturing of the ceramic structure may include sintering at a temperature of 1000°C to 1800°C, 1000°C to 1600°C, 1300°C to 2000°C, 1300°C to 1800°C, or 1300°C to 1600°C. When the ceramic structure is heat-treated at the same temperature as described above, grain coarsening occurs during sintering, so that the ceramic structure can be highly densified without defects or pores. Accordingly, when using the ceramic structure as an artificial tooth (eg, implant), there is an advantage that does not require a separate surface treatment.

The method may further include washing the solvent between the step of forming the ceramic compact and the step of preparing the ceramic structure. The solvent may be ethanol, methanol, isopropanol, acetone or water.

Hereinafter, the present invention will be described in more detail through Examples and the like according to the present invention, but the scope of the present invention is not limited by the Examples presented below.

production example

Tosoh's Zpex series powder was calcined at 900°C for 3 hours, 50% of the calcined powder was filled in a PE bottle, and 8-10 mm zirconia balls were mixed, followed by a ball milling process for about 1 day to prepare zirconia powder.

At this time, the calcination process serves to burn the binder present in the powder, and the ball mill process is an operation to break the coarse powder.

Examples 1 to 12

As shown in Table 2 below, the photocurable monomer, diluent and dispersant were added to a shear (paste) mixer dispenser and mixed at 1000 rpm for 10 minutes. The zirconia powder prepared in Preparation Example was divided into the mixed mixture three times to induce primary slurry complexing for 1 hour each, and the prepared slurry was compounded through a ball mill process for 3 hours to improve ceramic homogeneity. A slurry composition was prepared by adding a photo-curing initiator just before photo-curing and shear-mixing at a speed of 1000 rpm for 30 minutes.

Photocurable monomers and diluents
(Photocurable Monomer
& Diluent) Zirconia Powder
(Zirconia Powder) dispersant
(Dispersant) photocuring initiator
(Photo initiator) composition 1 TEGDMA IBA ZR BYK-180
(2wt%) PPO
(2wt% based on monomer) Density [g/cm ³ ] 1.076 0.986 6.07 1.075 1.17 Example 1 [g] 50
vol% 21 9 200 4 0.6 Example 2 [g] 55
vol% 21 9 252 5.04 0.6 composition 2 TEGDMA Camphor ZR BYK-180
(2wt%) TPO
(2wt% based on monomer) Density [g/cm ³ ] 1.076 0.992 6.07 1.075 1.136 Example 3 [g] 50
vol% 21 9 199 3.98 0.42 Example 4 [g] 55
vol% 21 9 250 5 0.42 composition 3 HDDA DECALIN ZR BYK-180
(3wt%) TPO
(2wt% based on monomer) Density [g/cm ³ ] 1.02 0.896 6.07 1.075 1.136 Example 5 [g] 50
vol% 21 9 227 6.81 0.42 Example 6 [g] 55
vol% 21 9 291 8.73 0.42 composition 4 HDDA Camphor ZR BYK-180
(2wt%) PPO
(2wt% based on monomer) Density [g/cm ³ ] 1.02 0.992 6.07 1.075 1.17 Example 7 [g] 50
vol% 21 9 207 4.14 0.42 Example 8 [g] 55
vol% 21 9 260 5.2 0.42 composition 5 TMPTA IDA ZR BYK-180
(2wt%) TPO
(2wt% based on monomer) Density [g/cm ³ ] 1.11 0.875 6.07 1.075 1.136 Example 9 [g] 50
vol% 21 9 219 6.57 0.42 Example 10 [g] 55
vol% 21 9 279 8.37 0.42 composition 6 TMPTA IBA ZR BYK-180
(2wt%) TPO
(2wt% based on monomer) Density [g/cm ³ ] 1.11 0.986 6.07 1.075 1.136 Example 11 [g] 50
vol% 21 9 210 6.3 0.42 Example 12 [g] 55
vol% 21 9 268 8.04 0.42

Example 13

The slurry composition prepared in Example 5 was injected into a 3D printer to prepare a ceramic structure through a tape-casting method. Specifically, since the doctor blade (Dr. At this time, as shown in FIG. 5, the doctor blade connected to the tube was designed to allow feeding wider than the diameter of the tube, and the slurry composition was injected quantitatively using a syringe pump. Then, the slurry composition was applied to a thickness of about 100 μm according to the previously designed 3D model, and then cured by irradiating light. Afterwards, all axes except the Z axis returned to the origin, and the same sequence was repeated to form a ceramic structure.

Experimental Example 1

In order to confirm the properties of the zirconia powder used in the present invention, the zirconia powder prepared in Preparation Example and Tosoh's Zpex series powder were photographed with a scanning electron microscope (SEM), and a slurry prepared by dispersing the zirconia powder in a monomer was prepared. It was photographed with a scanning electron microscope, and the results are shown in FIG. 1 .

Referring to FIG. 1 , it was confirmed that the Tosoh Zpex series powder in FIG. 1 (a) was formed into a mass of 30 to 70 μm by binding the powder by a binder, and the Tosoh Zpex series powder in FIG. 1 (c) is a spectacle It was confirmed that it was not dispersed in the chemical conversion monomer. 1(b), it was confirmed that the zirconia powder prepared in Preparation Example was calcined, the binder was removed, and the agglomerated powder was crushed to a size of about 0.55 μm in diameter by the ball mill process, and in FIG. 1(d) It was confirmed that the zirconia powder of Example was uniformly dispersed in the photocurable monomer through calcination and ball milling processes.

Through this, while the conventional zirconia powder is not dispersed in the monomer including the binder, the zirconia powder used in the present invention has the binder removed through calcination and ball milling process, so that when mixed with a photocurable monomer, dispersibility and fluidity are improved. it can be seen that In addition, due to the removal of the binder, the zirconia powder can be used for 3D printing because light reflection is reduced.

Experimental Example 2

In order to confirm the commercialization potential of the manual picker to find a suitable dispersant for the slurry composition according to the present invention, the solubility of the dispersant was measured by dissolving it directly with the photocurable monomer and diluent used in the present invention, and the results are shown in Table 3 It was.

dispersant CC-9 KD-1 KD-4 Topo BYK
-111 BYK
-163 BYK
-180 BYK
-190 BYK
-2001 BYK
-2012 BYK
-2013 Ainti-
Terra-U density
[g/cm ³ ] 1.08 0.9 0.9 0.88 1.16 0.9925 1.075 1.06 1.027 1.056 1.096 0.94 shape Liquid Solid Liquid Solid Liquid Liquid Liquid Liquid Liquid Liquid Liquid Liquid IBA △ X O O O O O △ O X O O TEGDMA △ X △ X O O O △ O X O - HDDA △ - O - O O O X O X O O DECALIN △ - O - O X X X X X X O HDDA + DECALIN O - O - O O O X O X O O O - dissolved
△ - middle
X - insoluble

Referring to Table 3, among the dispersants, CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-2001, BYK-2013, and Anti-Terra-U are photocurable monomers used in the present invention. And it was confirmed that the solubility with the diluent was excellent. Among them, although not shown in the table above, as a result of preparing a slurry using zirconia powder and a photocurable monomer using the eight dispersants, the rheology most suitable for digital optical technology (Digital Light Processing, DLP) of the tape-casting method ( rheology) was shown to be BYK-180.

Experimental Example 3

In order to confirm the rheological properties of the slurry composition according to the present invention, the viscosity according to the shear rate was measured for the slurry compositions prepared in Examples 1 and 2, and the results are shown in FIG. 2 .

Referring to FIG. 2, FIG. 2(a) is a photograph of the composition before and after adding the BYK-180 dispersant to the slurry composition according to the present invention, and it was confirmed that the slurry composition exhibited fluidity after the dispersant was added. In addition, FIG. 2(b) shows the viscosity values of the slurry compositions prepared in Examples 5 and 6 according to the shear rate, showing a shear-thinning behavior in which the viscosity decreases as the shear rate increases. confirmed that. Specifically, the dispersant effectively disperses the compositions in the slurry composition containing 55 vol% of the zirconia powder as well as the slurry composition containing 50 vol% of the zirconia powder, and the viscosity is changed from 300 Pa·s to 2 Pa·s at a shear rate of 0.1 to 100. was confirmed to decrease.

Through this, the slurry composition according to the present invention contains a dispersing agent and the viscosity decreases when a shear force is applied, and the viscosity increases again when the force is removed to form a thin film through a doctor blade-caching method. It can be seen that it is easy to apply. Specifically, in tape casting, the slurry is formed into a thin film with a doctor blade, and force is applied to the slurry. At this time, the viscosity of the slurry is lowered, so that a uniform layer of about 25 to 200 μm can be formed. It can be seen that the holding power of the uniform layer is increased because all the forces are removed and the viscosity is increased during heating.

Experimental Example 4

In order to confirm the curing thickness of the appropriate slurry composition when forming the ceramic structure according to the present invention, in the slurry composition prepared in Example 5 and the composition of Example 5 by a tape-casting method using a 3D printer, only the photocuring initiator was used as PPO. The changed composition was applied and light was irradiated at a wavelength of 405 nm to measure the curing thickness according to the light irradiation time for each type of photoinitiator, and the results are shown in Table 4.

Zirconia Slurry Cure Thickness Test according to Curing Time Photoinitiator types layer thickness [μm] 4s 5s 8s 10s 15s 20s 25s 30s 40s 50s 1m 2m 3m 5m PPO - - - - 60 70 80 90 100 110 120 140 190 220 TPO 50 60 70 80 - 120 - 140 150 170 180 - - -

Referring to Table 4, it was confirmed that the cured thickness increased as time increased, but after an appropriate time, the cured thickness did not increase any more even as time increased. Specifically, it was confirmed that when light was irradiated for about 30 seconds, it had a thickness of about 100 μm. In particular, when PPO (Phenylbis(2, 4, 6-trimethyl benzoylphosphine oxide) is added (Example 1), the cured thickness increases up to 5 minutes, but in terms of efficiency, when irradiated with light for 30 seconds, a thickness of 90 μm is formed. It can be seen that it is more efficient to repeatedly cure within 1 minute. In addition, when TPO (2,4,6-Trimethylbenzoyldiphenylphosphine oxide) was added (Example 3), a thickness of 140 μm was obtained when irradiated with light for 30 seconds. formation was confirmed.

In addition, it was confirmed that it takes 10 to 15 seconds to cure a thickness of 100 μm when irradiating light with a wavelength of 405 nm with a higher intensity.

Through this, it can be seen that the ceramic structure according to the present invention uses the slurry composition to control the curing time within a thickness of 100 μm to secure interlayer bonding strength and high-precision 3D printing for artificial tooth formation is possible. In addition, it can be seen that the curing time can be adjusted according to the intensity of light even under light conditions of the same wavelength.

Experimental Example 5

In order to analyze the microstructure of the ceramic structure according to the present invention, the ceramic structure and its cut surface were observed by an experimental method based on ISO 13356-4.3.3 and ASTM E112 wire cutting method for the ceramic structure prepared in Example 13. , the results are shown in FIGS. 6 to 7 .

In addition, in order to examine the transmittance when the ceramic film prepared by applying the slurry composition according to the present invention is sintered, a circular sample was prepared using the slurry composition to meet the specifications (sintered body standard) with a diameter of 20 mm and a height of 1 mm. After positioning on the top, a photograph was taken, and the result is shown in FIG. 8 .

Referring to FIG. 6, images before and after sintering in which the ceramic structure prepared in Example 13 was heat treated at a temperature of 1100° C. and held at a final temperature of 1500° C. for 3 hours were shown before sintering (formed body) and after sintering (sintered body). As a result of observing the surface of FIG. 6 , it was confirmed that the molded article had a particle size of 0.2 to 0.3 μm, but had an average particle size of 0.64 μm after heat treatment, thereby confirming that grain coarsening occurred.

Referring to FIG. 7 , as a scanning electron microscope image of the fracture surface observed at low and high magnifications, it was confirmed that high densification was induced without defects or pores formed at low and high magnifications.

Referring to FIG. 8 , (a) is a photograph observed by placing a circular sample formed from the slurry composition prepared in Example 5 on a letter, and it was confirmed that excellent light transmittance was exhibited. (b) is a photograph observed by placing the circular sample formed from the slurry composition prepared in Example 5 on the image, and the color and shape of the image color were confirmed, and it was confirmed that excellent light transmittance was exhibited. In addition, (c) is a photograph observed by placing the tooth-shaped ceramic structure prepared in Example 13 on the image, and although it is a ceramic structure produced by the 3D printing method, it is difficult to confirm the exact shape of the image. It was confirmed that the transmittance was shown.

Through this, it can be seen that the ceramic structure according to the present invention is highly densified without pores and defects, so that scattering and diffraction of light is significantly lowered, and thus the transmittance is excellent.

Experimental Example 6

In order to confirm the physical strength of the ceramic structure according to the present invention, the flexural strength of the ceramic structure of Example 13 was measured several times through a three-point bending strength test according to ISO 6872 and the results are shown in Table 5.

flexural strength
(MPa) Primary Secondary tertiary 4th 5th 6th 7th 8th 962.14 1015.19 1000.55 1086.52 887.14 918.24 819.47 921.9 flexural strength
(MPa) 9th 10th 11th 12th 13th 14th 15th 916.41 823.6 776.8 713.4 770.8 720.7 873.3

Referring to Table 5, the ceramic structure prepared in Example 13 showed a minimum flexural strength of 713.4 MPa and a maximum of 1086.52 MPa as a result of measuring the flexural strength. Specifically, the flexural strength of the ceramic structure of Example 13 was found to be 830 MPa on average.

Through this, it can be seen that the ceramic structure prepared with the slurry composition according to the present invention has excellent flexural strength and thus has excellent durability as well as excellent workability.

Claims (18)

Based on the total composition, 80 to 90% by weight of zirconia powder, 6 to 10% by weight of a photocurable monomer, 2 to 6% by weight of a diluent and a dispersing agent,
The zirconia powder does not contain a binder,
The dispersant is a slurry composition comprising 0.5 to 4% by weight relative to the zirconia powder. The method of claim 1,
The dispersant is selected from the group consisting of CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-190, BYK-2001, BYK-2012, BYK-2013 and Anti-Terra-U One or more slurry compositions. delete The method of claim 1,
The slurry composition comprising the photocurable monomer and the diluent in a weight ratio of 6:4 to 8:2. The method of claim 1,
The slurry composition further comprises a photocurable initiator,
A slurry composition comprising the photocurable initiator in an amount of 0.5 wt% to 3 wt% based on the photocurable monomer. calcining 80 to 90% by weight of the zirconia powder based on the total composition and pulverizing the zirconia powder using a ball mill;
preparing a mixture by mixing 6 to 10% by weight of a photocurable monomer, 2 to 6% by weight of a diluent, and a dispersing agent based on the total composition;
Dispersing the zirconia powder that has undergone the grinding step in the mixture,
The zirconia powder does not contain a binder,
The method for producing a slurry composition, characterized in that the dispersant is contained in an amount of 0.5 to 4% by weight relative to the zirconia powder. 7. The method of claim 6,
The grinding step is a method for producing a slurry composition, characterized in that the calcination for 1 to 5 hours at a temperature of 800 ℃ to 1000 ℃. 7. The method of claim 6,
In the step of preparing the mixture, the dispersant is one selected from the group consisting of CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-2001, BYK-2013 and Anti-Terra-U Method for producing a slurry composition, characterized in that the above. 7. The method of claim 6,
In the preparing of the mixture, the photocurable monomer and the diluent are mixed in a weight ratio of 6:4 to 8:2. 7. The method of claim 6,
Method for producing a slurry composition further comprising the step of adding a photocuring initiator after the step of dispersing the zirconia powder. A ceramic structure using the slurry composition according to claim 1 . 12. The method of claim 11,
The ceramic structure has a strength of 700 MPa or more. 12. The method of claim 11,
The ceramic structure, characterized in that the transmittance of the ceramic structure is 1 to 45%. applying the slurry composition according to claim 1 with a blade to a thickness of 25 to 200 μm;
photo-curing the applied slurry composition by irradiating light to form a ceramic film;
forming a ceramic molded body by repeatedly performing the steps of applying with the blade and forming a ceramic film; and
Method of manufacturing a ceramic structure comprising the step of manufacturing a ceramic structure by heat-treating the ceramic compact. 15. The method of claim 14,
The forming of the ceramic film is a method of manufacturing a ceramic structure, characterized in that irradiated with light of 360 nm to 450 nm for 2 seconds to 60 seconds. 15. The method of claim 14,
In the step of applying the blade, the shape of the slurry composition applied with the blade is changed according to the shape in which the slurry composition is injected based on the blade length direction,
A method of manufacturing a ceramic structure, characterized in that the standard deviation of the thickness of the applied slurry composition is 10% or less. 15. The method of claim 14,
The step of forming the ceramic compact is a method of manufacturing a ceramic structure using a tape-casting method. 15. The method of claim 14,
The manufacturing of the ceramic structure is a method of manufacturing a ceramic structure by sintering at a temperature of 1000 ℃ to 2000 ℃.

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