KR20210047428A - Slurry composite containing zirconia with high transmittance and strength, Preparation method thereof, and Ceramic structure using the same - Google Patents

Abstract

The present invention can manufacture a zirconia ceramic structure using 3D printing technology and relates to a slurry composition containing zirconia, a photocurable monomer, a diluent, and a dispersant, a manufacturing method thereof, a ceramic structure using the same, and a manufacturing method of the ceramic structure. The slurry composition exhibits very little light scattering and thus has very excellent shape forming ability so that a zirconia ceramic structure having a very complex shape can be easily manufactured using 3D printing technology, and a wasteful process 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 the ceramic structure has excellent processability.

Description

Slurry composite containing zirconia with high transmittance and strength, Preparation method thereof, and Ceramic structure using the same}

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

Recently, research on the development of 3D printing technology for patient-customized medical materials that can manufacture 3D shapes in consideration of individual patient characteristics is attracting worldwide attention. Unlike the technology of manufacturing patient-specific artificial bones and teeth through a cutting process based on the existing material of a predetermined 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, it is possible to apply even in the case, and it is possible to manufacture a shape at a faster speed while reducing the loss of material than before.

Various 3D printing technologies for manufacturing ceramic structures have been developed so far, and in particular, in the case of the tape-casting method-based photocurable 3D printing technology used in the present invention, starting with the target ceramic powder, a photocurable posting agent has been developed. The liquid slurry mixed with the monomer-diluent-dispersant mixture is selectively cured and stacked one layer at a time to the desired shape and thickness using UV light. There are strengths.

The characteristics necessary for artificial teeth used in living bodies include high physical properties, human-mimicking aesthetics, and good biocompatibility. For this, currently widely used materials include gold, titanium, and zirconia. Gold, titanium, etc., which were used the most in the past, showed excellent results in terms of physical properties and biocompatibility, but their aesthetics are very low, and these days are all satisfied. The demand for zirconia artificial teeth that can be made is increasing.

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

It is an object of the present invention to provide a slurry composition in which zirconia is very uniformly dispersed with a high zirconia content and adequate flowability (viscosity) by optimizing the contents of a photocurable monomer, a diluent, a dispersant and a photocuring initiator, Using a tape-casting method-based photocurable 3D printing technology, a ceramic structure having high transmittance and high strength is provided.

The present invention includes 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;

Including the step of dispersing the zirconia powder subjected to the grinding step in the mixture,

The zirconia powder provides a method for preparing a slurry composition, characterized in that dispersion in 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 to a thickness of 25 to 200 μm with a blade;

Forming a ceramic film by photocuring the applied slurry composition by irradiating light;

Forming a ceramic formed body by repeatedly performing the step of applying with the blade and the step of forming a ceramic film; And

It provides a method for manufacturing a ceramic structure including the step of manufacturing a ceramic structure by heat-treating the ceramic formed body.

The present invention is a slurry composition having fluidity suitable for 3D printing technology, including a high content of zirconia and an optimized content of a photocurable monomer, a diluent and a dispersant. It is very good, and it is possible to simply manufacture a zirconia ceramic structure having a very complex shape by using 3D printing technology, and it is possible to reduce the wasteful process. In addition, the manufactured ceramic structure has high strength so that it is not broken during operation, and it is possible to modify its shape and surface by using a dental grinding machine or the like, so it has excellent processability.

1 is an image photographed with a scanning electron microscope (SEM) of a zirconia powder according to an embodiment: (a) is an image of a commercially obtained zirconia powder, and (b) is a calcination and ball milling process in the Example It is an image of zirconia powder, (c) is an image of a slurry obtained by dispersing a commercially obtained zirconia powder in a monomer, and (d) is a slurry obtained by dispersing a zirconia powder that has undergone calcination and ball milling processes in the monomer in the examples. This is an image taken.
2 is a graph showing an image (a) when a dispersant is added to a slurry composition according to an exemplary embodiment in a certain amount and a viscosity value according to a shear rate of the slurry composition according to an exemplary embodiment.
3 is an image of a three-dimensional ceramic structure prepared by using a 3D printing technology of a slurry composition according to the present invention.
4 is an image schematically illustrating a method of manufacturing a ceramic structure according to the present invention.
5 is an image photographing a blade for manufacturing a ceramic structure according to the present invention and a method of manufacturing the ceramic structure.
6 is an image photographed 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, and (b) is an image of the surface of the ceramic structure after sintering. It is an image.
7 is an image photographed with a scanning electron microscope (SEM) of a fracture surface of a 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 of the slurry composition prepared in Example 5 on a letter, ( b) is a photograph obtained by placing a circular sample formed of the slurry composition prepared in Example 5 on an image, and (c) is a photograph obtained by placing a ceramic structure in the shape of a tooth prepared in Example 13 on the image. It is a picture.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

The present invention includes 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 contain a binder. In general, commercially available zirconia powder contains a binder on its surface, but in this case, it is difficult to use for 3D printing due to light reflection or the like. On the other hand, the zirconia powder is calcined, does not contain a binder, has no problems such as light reflection, and 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% to 60% by volume based on the total composition. More specifically, the zirconia powder is based on the total composition 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 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% to 95% by weight 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 zirconia powder in a high content as described above by including zirconia powder that does not contain 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% to 10% by weight based on the total composition, and the diluent may be included in an amount of 2% to 6% by weight based on the total composition. Specifically, the photocurable monomer is included in 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). At this time, 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 one or more 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) And Anti-Terra-U contains an acidic polyester-based polymer, BYK-111 contains a copolymer containing an acidic group, and BYK-163, BYK-190, BYK-2012 and BYK-2013 are pigment affinity groups. Including a block copolymer containing, 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 name and common name 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 (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 based on 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 Alternatively, it may be included in an amount of 1 to 2% by weight. By including the dispersant as described above, the slurry composition according to the present invention can 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 cured by irradiation with 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% to 3% by weight 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 It may be included in to 2% by weight. By including the photocurable initiator as described above, it is possible to implement a shape by digital optical technology 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;

Including the step of dispersing the zirconia powder subjected to the pulverizing step in the mixture,

The zirconia powder provides a method for preparing a slurry composition, characterized in that dispersion in 1% to 60% by volume relative to the total composition.

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

In addition, the pulverizing step may be performed by mixing the calcined zirconia powder with 8 to 10 mm zirconia balls and performing ball milling using a ball mill for more than 24 hours. Specifically, the pulverizing step may be performed by mixing the calcined zirconia powder with the zirconia balls and proceeding for at least 24 hours or more, up to 1 week, but 24 hours to 50 hours, 24 hours to 40 hours, or 24 hours to 30 hours. Ball milling can be performed using a ball mill for a period of time.

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

As an example, in the step of preparing the mixture, a photocurable monomer and a diluent may be mixed in a weight ratio of 6:4 to 9:1. Specifically, the photocurable monomer and 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% to 10% by weight based on the total composition, and the diluent may be mixed in an amount of 2% to 6% by weight based on the total composition. Specifically, the photocurable monomer is mixed in an amount of 6% to 9%, 7% to 10%, 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 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). At this time, 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 one or more 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 based on 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 of the zirconia powder Can be mixed with. By mixing the dispersant as described above, the slurry composition according to the present invention can have rheology applicable to 3D printing.

As an example, in the step of dispersing the zirconia powder, a photocurable monomer, a diluent, and a dispersant may be mixed with a zirconia powder in an amount of 1% to 60% by volume compared 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% 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 dispersed in the mixture in an amount of 80% to 95% by weight based on the total composition. Specifically, the zirconia powder may be dispersed in the mixture in 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, after the step of dispersing the zirconia powder, it may further include a step of adding a photocuring initiator. The photocurable initiator is not particularly limited as long as it is an initiator cured by irradiation with 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, a photocurable initiator may be added in an amount of 0.5% to 3% by weight 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 It can be added in an amount of 2% by weight. By adding the photocurable initiator as described above, it is possible to implement a shape by digital optical technology 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 the ceramic formed body using the slurry composition according to the present invention, and can implement not only a simple structure but also a complex shape such as a screw or a tooth, and a light scattering phenomenon occurs. I never do that. In addition, since the strength of the ceramic structure is high after photo-curing, it is not broken during operation, and it has excellent processability so that the shape and surface can be modified with a dental grinding machine or the like.

As an example, the 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 30 to 35% transmittance. In general, when a ceramic structure is manufactured by a pressing process, the transmittance is about 45%, but when a ceramic structure is manufactured by 3D printing, the possibility of interfering the transmittance by stacking a ceramic film is high. Although the possibility of negatively affecting the transmittance of is high, the ceramic structure according to the present invention may have the transmittance as described above by setting a photocuring condition and laminating a ceramic film having a high transmittance to prevent interference due to an interface with the structure.

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, so that the strength and transmittance may be excellent.

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

Forming a ceramic film by photocuring the applied slurry composition by irradiating light;

Forming a ceramic formed body by repeatedly performing the step of applying with the blade and the step of forming a ceramic film; And

It provides a method for manufacturing a ceramic structure including the step of manufacturing a ceramic structure by heat-treating the ceramic formed body.

As an example, in the step of applying with the blade, the form applied with the blade may be changed to the form in which the slurry composition is injected based on the length direction of the blade. As shown in Fig. 4, when the width and length of the plane are assumed to be X and Y, when the length of the blade is in the same direction as the Y axis and is injected narrowly in the Y axis as shown in (A), a thin film is formed with a doctor blade. Even so, it is possible to manufacture a ceramic film having a narrow shape in the Y-axis direction. In addition, as shown in (B), since a film with a larger area than in (A) is formed when the film is injected widely in the Y-axis direction, it is possible to manufacture a ceramic film with a relatively large area.

For example, in the step of applying with the blade, the shape of the slurry composition applied with the blade changes according to the shape in which the slurry composition is injected based on the length direction of the blade, but the standard deviation of the thickness of the applied slurry composition is 10% or less. I 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, the method of manufacturing a ceramic structure according to the present invention can uniformly form a thin film of 100 μm or less or 50 μm or less through the blade.

As an example, the step of forming 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 a ceramic film is photocured by irradiating light of 360nm to 450nm 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. You can do it.

In addition, the step of forming the ceramic molded body may be performed by a tape-casting method. In the tape-casting method, a slurry composition having an appropriate viscosity is injected to form a thin film using a doctor blade, and the shape is formed by irradiating a light source on the film. It is a manufacturing technology. By manufacturing the ceramic structure using the taping method, it is possible to elaborately manufacture a ceramic structure having a complex structure such as a tooth, and it is possible to significantly reduce the amount of ceramic to be cut to manufacture an artificial tooth.

The step of manufacturing the ceramic structure may be performed by sintering at a temperature of 1000°C to 2000°C. Specifically, the step of manufacturing the ceramic structure may be sintered 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 above temperature, grain coarsening occurs during sintering, so that it can be highly densified without defects or pores. Accordingly, when the ceramic structure is used as an artificial tooth (for example, an implant), there is an advantage that a separate surface treatment is not required.

It may further include washing the solvent between the step of forming the ceramic molded body and the step of manufacturing 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 according to the present invention, but the scope of the present invention is not limited by the examples presented below.

Manufacturing 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 8-10mm zirconia balls were mixed to produce zirconia powder through a ball mill process for about 1 day.

At this time, the calcination process serves to burn out the binder existing in the powder, and the ball mill process is an operation for breaking the coarse powder.

Examples 1 to 12

As shown in Table 2 below, a photocurable monomer, a diluent, and a dispersant were added to a shear (paste) mixer dispenser, followed by mixing at 1000 rpm for 10 minutes. Dividing the zirconia powder prepared in Preparation Example into the mixed mixture in a total of 3 times to induce the primary slurry complexation for 1 hour each, and the prepared slurry after compounding the slurry through a ball mill process for 3 hours to improve the ceramic homogeneity. Immediately before photocuring, a photocuring initiator was added and shear-mixed for 30 minutes at a speed of 1000 rpm to prepare a slurry composition.

Photocurable monomer and diluent
(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 located in the 3D printer moves in one direction of the xy plane to form a film, the slurry film was formed by placing the slurry in the long direction of the blade blade before the blade moves. At this time, as shown in FIG. 5, the doctor blade connected to the tube was designed to enable 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 in accordance with the previously designed 3D model, and then cured by irradiation with light. After that, after all axes except the Z axis returned to the origin, the same sequence was repeated to form a ceramic structure.

Experimental Example 1

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

Referring to FIG. 1, in FIG. 1(a), it was confirmed that the powders of Tosoh's Zpex series were bonded by a binder to form a lump having a size of 30 to 70 μm, and in FIG. 1(c), the Tosoh's Zpex series powders were It was confirmed that it was not dispersed in the chemical conversion monomer. It was confirmed that the zirconia powder prepared in Preparation Example in FIG. 1(b) was subjected to a calcination process to remove the binder, and the agglomerated powders were finely broken by a ball mill process to form a size of about 0.55 μm in diameter, and in FIG. 1(d) It was confirmed that the zirconia powder of the example was uniformly dispersed in the photocurable monomer through calcining and ball milling.

Through this, while the existing zirconia powder is not dispersed in the monomer including the binder, the zirconia powder used in the present invention is removed by the calcination and ball mill process, so that when mixed with a photocurable monomer, dispersibility and fluidity are improved. Can be seen. In addition, due to the removal of the binder, zirconia powder can be used for 3D printing by reducing light reflection and the like.

Experimental Example 2

In order to find out the possibility of commercialization of the manual extractor in order to find an appropriate dispersant for the slurry composition according to the present invention, the solubility of the dispersant was measured by directly dissolving it with the photocurable monomer and diluent used in the present invention. I got it.

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
△-medium
X-not dissolved

Looking at Table 3, among the dispersants, CC-9, KD-4, BYK-111, BYK-163, BYK-180, BYK-2001, BYK-2013, 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 tape-casting digital light processing (DLP) ( rheology) was shown by 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 exhibits fluidity after adding the dispersant. In addition, Figure 2 (b) shows the viscosity value according to the shear rate of the slurry composition prepared in Examples 5 and 6, showing a shear-thinning behavior in which the viscosity decreases as the shear rate increases. Confirmed. Specifically, the dispersant effectively disperses the compositions in a slurry composition containing 55 vol% as well as a slurry composition containing 50 vol% of zirconia powder, and a viscosity of 300 Pa·s to 2 Pa·s at a shear rate of 0.1 to 100. It was confirmed that it decreased.

Through this, the slurry composition according to the present invention includes a dispersant, and the viscosity decreases when a shear force is applied and the viscosity increases again when the force is removed, thereby forming a thin film through a doctor blade. It can be seen that it is easy to apply. Specifically, in tape casting, a thin layer of the slurry is formed with a doctor blade, and force is applied to the slurry. At this time, the viscosity of the slurry is lowered to form a uniform layer of about 25 to 200 μm. At the time of firing, all the forces are removed and the viscosity increases, so it can be seen that the holding power of the uniform layer increases.

Experimental Example 4

In order to check the curing thickness of the slurry composition when forming the ceramic structure according to the present invention, only the photocuring initiator was used as PPO in the slurry composition prepared in Example 5 and the composition of Example 5 by using a tape-casting method using a 3D printer. The modified 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 curing thickness test according to curing time Type of photoinitiator Layer thickness [㎛] 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 - - -

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

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

Through this, it can be seen that the ceramic structure according to the present invention is capable of high-precision 3D printing for forming artificial teeth by controlling the curing time within 100 μm thickness using the slurry composition to secure interlayer bonding strength. In addition, it can be seen that the curing time can be adjusted according to the intensity of light even under the 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 the test 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 find out the transmittance of the ceramic film prepared by applying the slurry composition according to the present invention when sintered, a circular sample was prepared using the slurry composition in accordance with the standards of 20 mm in diameter and 1 mm in height (based on the sintered body). After being placed on top, a picture was taken, and the results are 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 and after sintering (formed body) and after sintering (sintered body). As a result of observation of the surface of FIG. 6, it was confirmed that the molded body had a particle size of 0.2 to 0.3 μm, whereas after the heat treatment, the molded body had an average particle size of 0.64 μm, and thus grain coarsening occurred.

Referring to FIG. 7, as a scanning electron microscope image of the fracture surface observed at low and high magnification, it was confirmed that defects or pores were not formed at low and high magnification, and high densification was induced.

Referring to FIG. 8, (a) is a photograph of a circular sample formed of the slurry composition prepared in Example 5 by placing it on a letter, and it was confirmed that excellent transmittance was observed. (b) is a photograph observed by placing a circular sample formed of the slurry composition prepared in Example 5 on an image, and it was confirmed that the color and shape of the image color were confirmed, indicating excellent transmittance. In addition, (c) is a photograph obtained by placing the ceramic structure in the shape of a tooth prepared in Example 13 on the image and observed. Despite the 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 light scattering and diffraction are remarkably low and light transmittance is excellent.

Experimental Example 6

In order to check the physical strength of the ceramic structure according to the present invention, 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 3rd 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 exhibited a flexural strength of at least 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 made of the slurry composition according to the present invention has excellent flexural strength and thus not only excellent durability but also excellent workability.

Claims (18)

Including zirconia powder, photocurable monomer, diluent and dispersant,
The zirconia powder is a slurry composition comprising 1% to 60% by volume based on the total composition. 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. Is more than one type,
The content of the dispersant is 0.5 to 4% by weight of the zirconia powder slurry composition. The method of claim 1,
The slurry composition, characterized in that the zirconia powder does not contain a binder. The method of claim 1,
A slurry composition comprising the photocurable monomer and a diluent in a weight ratio of 6:4 to 9:1. 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% to 3% by weight based on the photocurable monomer. Calcining the zirconia powder and pulverizing it using a ball mill;
Preparing a mixture by mixing a photocurable monomer, a diluent, and a dispersant;
Including the step of dispersing the zirconia powder subjected to the pulverizing step in the mixture,
The method for producing a slurry composition, wherein the zirconia powder is mixed in an amount of 1% to 60% by volume relative to the total composition. The method of claim 6,
The pulverizing step is a method of producing a slurry composition, characterized in that calcining for 1 to 5 hours at a temperature of 800 ℃ to 1000 ℃. 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 That’s it,
The method for producing a slurry composition, wherein the dispersant is mixed in an amount of 0.5 to 4% by weight based on the zirconia powder. The method of claim 6,
In the step of preparing the mixture, a photocurable monomer and a diluent are mixed in a weight ratio of 6:4 to 9:1. The method of claim 6,
A method for producing a slurry composition further comprising the step of adding a photocuring initiator after the step of dispersing the zirconia powder. Ceramic structure using the slurry composition according to claim 1. The method of claim 11,
The ceramic structure has a strength of 700 MPa or more. The method of claim 11,
Ceramic structure, characterized in that the transmittance of the ceramic structure is 1 to 45%. Applying the slurry composition according to claim 1 to a thickness of 25 to 200㎛ with a blade;
Forming a ceramic film by photocuring the applied slurry composition by irradiating light;
Forming a ceramic formed body by repeatedly performing the step of applying with the blade and the step of forming a ceramic film; And
A method of manufacturing a ceramic structure comprising the step of heat-treating the ceramic formed body to manufacture a ceramic structure. The method of claim 14,
The step of forming the ceramic film is a method of manufacturing a ceramic structure, characterized in that irradiating light of 360nm to 450nm for 2 to 60 seconds. The method of claim 14,
In the step of applying with the blade, the shape of the slurry composition applied with the blade is changed according to the form in which the slurry composition is injected based on the blade length direction
The method of manufacturing a ceramic structure, characterized in that the standard deviation of the thickness of the applied slurry composition is 10% or less. The method of claim 14,
The step of forming the ceramic molded body is a method of manufacturing a ceramic structure using a tape-casting method. The method of claim 14,
The step of manufacturing the ceramic structure is a method of manufacturing a ceramic structure by sintering at a temperature of 1000°C to 2000°C.

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