TW202134330A - Resin composition, resin composition for three-dimensional models, and dental resin composition - Google Patents

Abstract

The present invention provides a resin composition, a resin composition for three-dimensional models, and a dental resin composition, each of which has excellent transparency, while exhibiting excellent curability. A resin composition which contains a curable resin and inorganic particles, while being characterized in that: the difference between the refractive indexes ND of the inorganic particles and the curable resin after curing is ±0.1 or less; and the light transmittance of the inorganic particles at the wavelength of 405 nm is 10% or more.

Description

Resin composition, resin composition for three-dimensional objects, and resin composition for dentistry

The present invention relates to a resin composition, a resin composition for three-dimensional objects, and a resin composition for dentistry.

Previously, there has been known a method of obtaining a three-dimensional molded object of a cured product containing a curable resin by layering a curable resin or the like. For example, methods such as a photo-forming method, a powder sintering method, and a fused deposition modeling (FDM) method have been proposed, and they have been put into practical use.

For example, in the optical shaping method, a three-dimensional shaped object is manufactured in the following manner. First, a molding table is set in a tank filled with uncured curable resin, and the molding surface of the molding table is irradiated with light (for example, ultraviolet rays) to harden the curable resin. Thereby, a hardened layer of the required pattern is formed on the forming surface. Next, by moving the molding table one level, the uncured curable resin is reintroduced onto the cured layer. Secondly, irradiate the shaping surface with light again to form a new hardened layer on the hardened layer. By repeating this operation, the desired three-dimensional shape is obtained. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 7-26060

[The problem to be solved by the invention]

The photo-forming method is easy to manufacture precise three-dimensional shaped objects, but on the other hand, there is a problem that the mechanical strength of the hardened object is likely to be lowered. In order to improve this problem, Patent Document 1 proposes to use a resin composition obtained by adding inorganic particles to a curable resin.

However, with regard to this resin composition, light scatters at the interface between the curable resin and the inorganic particles, which tends to reduce the transparency of the cured product. In addition, it is easy to reduce the curability of the resin composition. For example, in the stage of manufacturing a three-dimensional object, if the curability of the resin composition is low, the production efficiency of the three-dimensional object is likely to decrease.

Also, for example, when a resin composition is used as a dental resin composition, if the resin composition has low transparency or curability, it is difficult to use for dental use.

Based on the above circumstances, the object of the present invention is to provide a resin composition, a resin composition for three-dimensional objects, and a resin composition for dentistry that are excellent in transparency and excellent curability. [Technical means to solve the problem]

The resin composition of the present invention is characterized in that it contains a curable resin and inorganic particles, and the difference between the refractive index nd of the inorganic particles and the curable resin after curing is within ±0.1, and the inorganic particles have a wavelength of 405 nm. The light transmittance is more than 10%.

In the resin composition of the present invention, the light transmittance of the inorganic particles at a wavelength of 405 nm is preferably 50% or more.

The resin composition of the present invention preferably has a light transmittance of 5% or more of the inorganic particles at a wavelength of 365 nm.

In the resin composition of the present invention, the inorganic particles are preferably glass.

The resin composition of the present invention preferably contains 30 to 75% of SiO ₂ , 1 to 20% of Al ₂ O ₃ , 0 to 30% of B ₂ O ₃ , and 0 to 20% of Li _{2 in the glass.} O＋Na ₂ O＋K ₂ O, 0.1～20% MgO＋CaO＋SrO＋BaO＋ZnO.

It is preferable that the resin composition of the present invention contains 40% or more of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ in terms of mass %.

The resin composition of the present invention preferably has an average particle diameter of the inorganic particles of 0.2-50 μm.

The resin composition of the present invention preferably contains 1 to 90% of inorganic particles by volume %.

The resin composition of the present invention preferably has a Young's modulus of the inorganic particles of 50 GPa or more.

In the resin composition of the present invention, the thermal expansion coefficient of the inorganic particles is preferably 60×10 ^-7 /°C or less at 30 to 100°C.

The resin composition of the present invention preferably has inorganic particles having a light reflectance of 10% or less at a wavelength of 250 to 440 nm.

The resin composition of the present invention preferably has a buffer layer on the surface of the inorganic particles.

In the resin composition of the present invention, the refractive index nd of the buffer layer is preferably lower than the refractive index nd of the inorganic particles.

The resin composition for a three-dimensional object of the present invention is characterized by using the above-mentioned resin composition.

The dental resin composition of the present invention is characterized by using the above-mentioned resin composition.

The manufacturing method of the three-dimensional object of the present invention is characterized in that it selectively irradiates an uncured layer containing an uncured resin composition with light to form a hardened layer with a specific pattern, and forms a new layer on the hardened layer. After the unhardened layer of, irradiate light to form a new hardened layer with a specific pattern that is continuous with the hardened layer, and repeat the layering of hardened layers until a specific three-dimensional shape is obtained; and use the above-mentioned resin composition As a resin composition. [Effects of Invention]

According to the present invention, it is possible to provide a resin composition, a resin composition for three-dimensional objects, and a resin composition for dentistry that are excellent in transparency and excellent curability.

The resin composition of the present invention is characterized in that it contains a curable resin and inorganic particles, the difference in refractive index nd between the inorganic particles and the cured resin is within ±0.1, and the light transmittance of the inorganic particles at a wavelength of 405 nm It is more than 10%. Furthermore, the light transmittance in the present invention means the value of the total light transmittance measured at a thickness of 1 mm, unless otherwise stated. In addition, the ultraviolet light in the present invention means light with a wavelength of 250 to 440 nm.

(Curable resin) As the curable resin, for example, an ultraviolet curable resin is preferably used. As the ultraviolet curable resin, it is preferable to use a resin polymerized by radical species or cationic species, for example, acrylic resin, epoxy resin, etc. can be used. Examples of acrylic resins include ester acrylate resins and acrylic urethane resins.

The acrylic resin may also contain the following compounds. For example, as a monofunctional compound, for example, isopropyl acrylate, isopropyl methacrylate, dicyclopentenyl acrylate, acrylate acrylate, methacrylate acrylate, 2-hydroxyethyl acrylate, acrylic acid 2 -Hydroxypropyl ester, propylene glycol acrylate, vinyl pyrrolidone, acrylamide, vinyl acetate, styrene, etc. Examples of multifunctional compounds include trimethylolpropane triacrylate, EO modified trimethylolpropane triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol Diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, dicyclopentenyl diacrylate, polyester diacrylate, ortho Diallyl phthalate, etc. These monofunctional compounds and polyfunctional compounds can be used 1 type or in combination of 2 or more types. In addition, these compounds are not limited to those mentioned above.

Acrylic resin can use a photopolymerization initiator as a polymerization initiator. Examples include: 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, acetophenone, benzophenone, ketone, ketone, benzaldehyde, and chlorophyll , Anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, Michele ketone, etc. These polymerization initiators can be used singly or in combination of two or more kinds. Moreover, it is preferable to contain 0.1-10% of these polymerization initiators in mass% with respect to a monofunctional compound and a polyfunctional compound, respectively. Furthermore, a sensitizer such as an amine compound may be used in combination as needed.

The epoxy resin may also contain the following compounds. For example, hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexyl carboxylic acid 3,4-epoxycyclohexyl methyl ester, 2-(3,4-epoxycyclohexyl-5,5 -Spiro-3,4-epoxy)cyclohexane m-dioxane, bis(3,4-epoxycyclohexylmethyl) adipate, etc. In the case of using these compounds, energy-active cationic initiators such as triphenylsulfonium hexafluoroantimonate can be used.

Furthermore, if necessary, a leveling agent, a surfactant, an organic polymer compound, an organic plasticizer, an antistatic agent, etc. may be added to the curable resin.

_{The refractive index nd (nd re} ) of the curable resin after curing is preferably 1.40 or more, 1.45 or more, and particularly preferably 1.5 or more. In addition, the Abbe number νd (νd _re ) of the curable resin after curing is preferably 20-65, 30-65, and particularly preferably 40-60.

_{The refractive index nd (nd rs} ) of the curable resin before curing (ie, the uncured curable resin) is, for example, preferably 1.35 or more, 1.4 or more, and particularly preferably 1.45 or more. In addition, the Abbe number νd (νd _rs ) of the uncured curable resin is, for example, preferably 20-65, 30-65, and particularly preferably 40-60.

The curing shrinkage rate of the curable resin is preferably 10% or less, 9% or less, 8% or less, and particularly preferably 6% or less. In this way, it is easy to reduce the dimensional difference of the resin composition (ie, the cured product) after curing. The lower limit is not particularly limited, and is, for example, 0.5% or more. Furthermore, regarding the curing shrinkage rate, the specific gravity A1 of the uncured curable resin and the specific gravity A2 of the cured resin can be measured and calculated based on the following formula.

Curing shrinkage rate (%) = 100×(A2－A1)/A2

(Inorganic particles) The difference between the refractive index nd (nd _g ) of the inorganic particles and the refractive index nd (nd _re ) of the cured resin is within ±0.1, preferably within ±0.08, ±0.05, or ±0.03 , Particularly preferably within ±0.02. In this way, the scattering of light caused by the difference in refractive index between the curable resin and the inorganic particles can be suppressed, and it is easy to obtain a cured product with excellent transparency.

The difference between the refractive index nd (nd _g ) of the inorganic particles and the refractive index nd (nd _rs ) of the uncured curable resin is preferably within ±0.1, ±0.09, ±0.08, ±0.07, and more preferably ± Within 0.05. In addition, the difference between the Abbe number νd(νd _rs ) of the uncured curable resin and the Abbe number νd(νd _g ) of the inorganic particles is preferably within ±10 (including 10) and within ±9, especially Preferably, it is within ±8. In this way, in the step of curing the resin composition, the scattering of light caused by the difference in refractive index between the curable resin and the inorganic particles can be suppressed. Thereby, it is easy to irradiate light sufficiently to the depth direction of the uncured resin composition, and therefore, the curability of the resin composition can be improved.

The refractive index nd of the inorganic particles is, for example, preferably 1.40 to 1.90, 1.40 to 1.65, and particularly preferably 1.45 to 1.6. In addition, the Abbe number νd is, for example, preferably 20-65, 30-65, and particularly preferably 40-60. In this way, it is easy to match the optical constants with most curable resins such as acrylic resins and epoxy resins. In addition, the scattering of light caused by the difference in refractive index between the curable resin and the inorganic particles is suppressed, and it is easy to obtain a cured product with excellent transparency.

The light transmittance of the inorganic particles at a wavelength of 405 nm is 10% or more, ideally 20% or more, 30% or more, 50% or more, and particularly preferably 70% or more. In addition, the light transmittance of the inorganic particles at a wavelength of 365 nm is desirably 5% or more, 10% or more, 20% or more, 30% or more, and particularly desirably 50% or more. In this way, it is easy to sufficiently irradiate light to the depth direction of the uncured resin composition, and therefore the curability of the resin composition can be improved. Furthermore, by this, it is easy to increase the thickness of the hardened object layer hardened by one-time irradiation of light, and therefore it is easy to improve the manufacturing efficiency of the three-dimensional shaped object.

The light transmittance of the inorganic particles at a wavelength of 600 nm is preferably 60% or more, 70% or more, and more preferably 80% or more. In this way, it is easy to obtain a cured product with excellent transparency.

The inorganic particles are preferably glass. By using glass, it is easy to strictly control the refractive index difference between the inorganic particles and the curable resin. For example, SiO ₂ -B ₂ O ₃ -R' ₂ O (R' is an alkali metal element) glass, SiO ₂ -Al ₂ O ₃ -RO (R is an alkaline earth metal element) glass, SiO ₂ -Al ₂ O ₃ -R' ₂ O-RO series glass, SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ -R' ₂ O series glass, SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ -R' ₂ O -RO-based glass, SiO ₂ -R' ₂ O-based glass, SiO ₂ -R' ₂ O-RO-based glass.

As a specific glass composition, for example, it is preferable to contain 30 to 75% of SiO ₂ , 1 to 20% of Al ₂ O ₃ , 0 to 30% of B ₂ O ₃ , and 0 to 20% of Li _{2 in mass %.} O＋Na ₂ O＋K ₂ O, 0.1～20% MgO＋CaO＋SrO＋BaO＋ZnO. The glass containing this composition has excellent weather resistance and light transmittance in the ultraviolet region to the visible light region. Therefore, it is easy to improve the curability of the resin composition when irradiated with ultraviolet light. In addition, since the light transmittance in the visible light region is also excellent, it is easy to obtain a cured product having excellent transparency.

Hereinafter, the reason why the glass composition range is limited as described above will be explained. In addition, in the following description about the content of each component, unless otherwise specified, "%" means "mass%". In addition, in this manual, "○＋○＋・・・" means the total amount of the corresponding components.

SiO ₂ is a component that forms a glass network and significantly increases the light transmittance in the ultraviolet region to the visible light region. It is also a component that improves weather resistance. The content of SiO ₂ is preferably 30 to 75%, 35 to 73%, 40 to 70%, 50 to 70%, 51 to 65%, and particularly preferably 51 to 62%. If _{the content of SiO 2} is too small, it is difficult to obtain the above-mentioned effects. On the other hand, if _{the content of SiO 2} is too large, the viscosity of the glass increases, which tends to decrease the meltability.

Al ₂ O ₃ is a component that forms a glass network and increases the light transmittance in the ultraviolet region to the visible light region. Especially in high refractive index glass, it has the effect of easily increasing the light transmittance. The content of Al ₂ O ₃ is preferably 1-20%, 2-20%, 3-20%, 5-20%, 10-20%, 11-18%, and more preferably more than 15%-17%. If _{the content of Al 2} O ₃ is too small, it is difficult to obtain the above-mentioned effects. On the other hand, if _{the content of Al 2} O ₃ is too large, the viscosity of the glass increases, which tends to decrease the meltability.

B ₂ O ₃ is a component that forms a glass network and increases the light transmittance in the ultraviolet region to the visible light region. The content of B ₂ O ₃ is preferably 0-30%, 1-27.5%, 2-25%, 3-25%, 5-25%, 10-25%, and particularly preferably 11-20%. If _{the content of B 2} O ₃ is too large, the meltability is likely to decrease.

The content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ is preferably 40% or more, 50% or more, 55% or more, and more preferably 60% or more. In this way, it is easy to increase the light transmittance in the ultraviolet region to the visible light region and improve the weather resistance. The upper limit is not particularly limited, and if it is too large, the meltability is likely to decrease, so for example, it can be set to 99% or less, especially 98% or less.

Li ₂ O, Na ₂ O, and K ₂ O are components that lower the softening point. The content of Li ₂ O+Na ₂ O+K ₂ O is preferably 0-20%, 0-18%, 0-16%, 0-10%, 0-6%, 0-4%, and particularly preferably 0.1-4%. If the content of Li ₂ O+Na ₂ O+K ₂ O is too large, weather resistance or refractive index is likely to decrease. In addition, in the stage of producing inorganic particles, the components are likely to evaporate from the surface of the particles, and the refractive index of the inorganic particles is likely to be different. Furthermore, the resin composition is easily deteriorated. Furthermore, the content of each component of _{Li 2} O, Na ₂ O, and K _{2 O is preferably as follows.}

The content of Li ₂ O is preferably 0-20%, 0-18%, 0-16%, 0-10%, 0-6%, 0-4%, and particularly preferably 0.1-4%.

The content of Na ₂ O is preferably 0-20%, 0-18%, 0-16%, 0-10%, 0-6%, 0-4%, and particularly preferably 0.1-4%.

The content of K ₂ O is preferably 0-20%, 0-18%, 0-16%, 0-10%, 0-6%, 0-4%, and particularly preferably 0.1-4%.

The ratio of Li ₂ O＋Na ₂ O＋K ₂ O to SiO ₂ ＋Al ₂ O ₃ ＋B ₂ O ₃ , namely (Li ₂ O＋Na ₂ O＋K ₂ O)/(SiO ₂ ＋Al ₂ O ₃ ＋B ₂ O ₃ ) is preferably 0.2 or less, 0.1 Below, 0.08 or less, particularly preferably 0.05 or less. In this way, it is easy to further suppress the decrease in weather resistance. The lower limit is not particularly limited, and it can be set to 0.001 or more, for example.

MgO, CaO, SrO, BaO and ZnO are components that act as fluxes. In addition, it also has the effect of suppressing devitrification and improving weather resistance or chemical durability. The content of MgO+CaO+SrO+BaO+ZnO is preferably 0.1 to 20%, 0.2 to 15%, 0.5 to 10%, 1 to 9%, 1 to 5%, and particularly preferably 1 to 4%. If the content of MgO+CaO+SrO+BaO+ZnO is too small, the devitrification resistance tends to decrease. On the other hand, if the content of MgO+CaO+SrO+BaO+ZnO is too large, it is difficult to obtain a highly dispersed glass. In addition, it is easy to lower the light transmittance. Furthermore, the content of each component of MgO, CaO, SrO, BaO, and ZnO is preferably as follows.

The content of MgO is preferably 0 to 20%, 0.1 to 15%, 0.5 to 10%, 1 to 9%, 1 to 5%, and particularly preferably 1 to 4%.

The content of CaO is preferably 0 to 20%, 0.1 to 15%, 0.5 to 10%, 1 to 9%, 1 to 5%, and particularly preferably 1 to 4%.

The content of SrO is preferably 0 to 20%, 0.1 to 15%, 0.5 to 10%, 1 to 9%, 1 to 5%, and particularly preferably 1 to 4%.

The content of BaO is preferably 0 to 20%, 0.1 to 15%, 0.5 to 10%, 1 to 9%, 1 to 5%, and particularly preferably 1 to 4%.

The content of ZnO is preferably 0 to 20%, 0.1 to 15%, 0.5 to 10%, 1 to 9%, 1 to 5%, and particularly preferably 1 to 4%.

MgO + CaO + SrO + BaO + ZnO and _{SiO 2 + Al 2 O 3 +} B ₂ O ₃ ratio of i.e. (MgO + CaO + SrO + BaO + ZnO) / (SiO 2 + Al 2 O 3 + B 2 O 3) is preferably 0.4 or less, 0.2 or less, 0.1 or less, and particularly preferably 0.05 or less. In this way, it is easy to further suppress the decrease in weather resistance. The lower limit is not particularly limited, and it can be set to 0.001 or more, for example.

The content of Li ₂ O+Na ₂ O+K ₂ O+MgO+CaO+SrO+BaO+ZnO is preferably 30% or less, 20% or less, 10% or less, and particularly preferably 8% or less. In this way, it is easy to reduce the Abbe number, suppress the decrease in the refractive index, and suppress the difference in the refractive index. The lower limit is not particularly limited, and it can be set to, for example, 0.1% or more and 1% or more.

In addition, the above-mentioned glass may contain the following components in addition to the above-mentioned components.

TiO ₂ is a component that easily increases the refractive index and lowers the Abbe number. The content of TiO ₂ is preferably 0-15%, 0.1-10%, 0.2-5%, 0.5-3.5%, and particularly preferably 0.5-2%. If _{the content of TiO 2} is too large, the softening point is likely to rise. In addition, it is easy to lower the light transmittance.

Nb ₂ O ₅ is a component that easily improves weather resistance. It is also a component that easily increases the refractive index and lowers the Abbe number. The content of Nb ₂ O ₅ is preferably 0 to 20%, 0.1 to 15%, 1 to 10%, 1 to 5%, and particularly preferably 1 to 4%. If _{the content of Nb 2} O ₅ is too large, the softening point tends to rise. In addition, it is easy to lower the light transmittance.

WO ₃ is a component that easily increases the refractive index and lowers the Abbe number. The content of WO ₃ is preferably 0-20%, 0.1-15%, and particularly preferably 1-5%. If _{the content of WO 3} is too large, the softening point is likely to rise. In addition, it is easy to lower the light transmittance.

The content of TiO ₂ +Nb ₂ O ₅ +WO ₃ is preferably 0-30%, 0.1-20%, and particularly preferably 1-15%. In this way, it is easy to obtain glass with a higher refractive index and a lower Abbe number.

The content of TiO ₂ +Nb ₂ O ₅ +WO ₃ +SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ is preferably 50% or more, 60% or more, 70% or more, and more preferably 80% or more. In this way, it is easy to reduce the Abbe number and increase the light transmittance in the ultraviolet region to the visible light region. The upper limit is not particularly limited. For example, it can be set to 99% or less and 98% or less.

P ₂ O ₅ is a component that forms a glass network and easily increases the light transmittance or devitrification resistance of glass. Also, it is a component that tends to lower the softening point of glass. The content of P ₂ O ₅ is preferably 0-5%, 0-4.5%, and particularly preferably 0-4%. If _{the content of P 2} O ₅ is too large, the refractive index is likely to decrease. In addition, streaks are easily generated.

ZrO ₂ is a component that easily improves the weather resistance and the refractive index. The content of ZrO ₂ is preferably 0-10%, 0-7.5%, and particularly preferably 0-5%. If _{the content of ZrO 2} is too large, the softening point is likely to rise. In addition, it is easy to reduce the devitrification resistance.

F ₂ is a component that tends to lower the softening point. In addition, it is also a component that is easy to significantly increase the light transmittance in the ultraviolet region. The content of F ₂ is preferably 0-10%, 0-5%, 0-4%, and particularly preferably 0-3%. If _{the content of F 2} is too large, weather resistance and devitrification resistance are likely to deteriorate.

La ₂ O ₃ is a component that easily increases the refractive index and increases the Abbe number. The content of La ₂ O ₃ is preferably 0-20%, 0-15%, 0-10%, and particularly preferably 0-5%. If _{the content of La 2} O ₃ is too large, the softening point tends to rise. In addition, it is easy to deteriorate the devitrification resistance and lower the viscosity of the liquid phase.

Fe ₂ O ₃ , NiO, Cr ₂ O ₃ and CuO are components that easily color the glass and reduce the light transmittance in the ultraviolet range to the visible light range. Therefore, the content thereof is preferably 1% or less, 0.75% or less, and particularly preferably 0.5% or less.

Sb ₂ O ₃ and CeO ₂ are components that easily suppress the decrease in light transmittance. The content of Sb ₂ O ₃ and CeO ₂ is preferably 0 to 1%, 0 to 0.8%, 0 to 0.5%, 0 to 0.2%, and particularly preferably 0 to 0.1%. If the content thereof is too large, devitrification is likely to occur.

For environmental reasons, it is preferable that the lead component (PbO, etc.) and arsenic component (As ₂ O _3, etc.) are not substantially contained. Furthermore, in the above description, "substantially not contained" means that it is not deliberately contained as a raw material, and specifically means that the content of each is less than 0.1%.

The inorganic particles can be used in the form of beads, powder, fibers, and the like. These can be used alone or in combination. It is particularly preferable to use bead-shaped inorganic particles. The bead-shaped inorganic particles have excellent fluidity and easily suppress the increase in the viscosity of the resin composition. Bead-shaped inorganic particles, for example, are particularly suitable for resin compositions with a large amount of inorganic particles added. Furthermore, the "bead shape" in the present invention means particles shaped into a spherical shape, but it may not necessarily be a true spherical shape.

The average particle diameter of the inorganic particles is preferably 0.2-50 μm, 0.2-40 μm, 0.2-30 μm, 0.2-20 μm, 0.2-10 μm, 0.2-9 μm, 0.3-8 μm, and particularly preferably 0.5-6 μm. In this way, it is easy to improve the surface smoothness of the hardened product. If the average particle diameter of the inorganic particles is too small, the fluidity of the resin composition is likely to decrease. On the other hand, if the average particle diameter of the inorganic particles is too large, the light scattering caused by the difference in refractive index will increase, and it will be difficult to obtain a cured product with excellent transparency. In addition, it is difficult to sufficiently irradiate light to the depth direction of the uncured resin composition, and therefore it is easy to reduce the curability of the resin composition. Furthermore, by this, the thickness of the hardened object layer hardened by one-time light irradiation is reduced, and the manufacturing efficiency of the three-dimensional shaped object is easily reduced. Furthermore, it is difficult to mirror-finish the surface of the hardened object.

Preferably, it contains 1 to 90%, 5 to 85%, 10 to 80%, 15 to 80%, 15 to 70%, 15 to 65%, especially 15 to 55% by volume% relative to the curable resin Of inorganic particles. By adding inorganic particles, it is easy to improve the mechanical strength of the resin composition. Moreover, even if it is irradiated with light for a short time, it is easy to harden the curable resin. Furthermore, it is easy to reduce the dimensional difference caused by the shrinkage of the curable resin. In particular, when it is used as a resin composition for dentistry, etc., when mechanical strength is required for the resin composition, it is preferable to contain 25 to 90% and 30 to 85% by volume relative to the curable resin. , 40-85%, 50-80%, especially 51-80% inorganic particles. If there are too few inorganic particles, it is difficult to obtain the above-mentioned effects. In addition, it is difficult to reflect the strength or hardness possessed by the inorganic particles to the hardened product. On the other hand, if there are too many inorganic particles, light scattering increases, and it is difficult to obtain a cured product with excellent transparency. In addition, it is difficult to sufficiently irradiate light to the depth direction of the uncured resin composition, and therefore it is easy to reduce the curability of the resin composition. Moreover, by this, the thickness of the hardened object layer hardened by one light irradiation becomes small, so that the manufacturing efficiency of the three-dimensional shaped object is easily reduced. Furthermore, the viscosity of the curable resin becomes too high, which easily makes handling difficult.

The Young's modulus of the inorganic particles is preferably 50 GPa or more, 55 GPa or more, and particularly preferably 60 GPa or more. If the Young's modulus of the inorganic particles is too low, the mechanical strength of the obtained hardened product is likely to be low.

The thermal expansion coefficient of the inorganic particles at 30-100°C is preferably 60×10 ^-7 /°C or less, 55×10 ^-7 /°C or less, and particularly ^{preferably 50×10 -7} /°C or less. In this way, it is easy to improve the dimensional stability of the obtained hardened product.

The light reflectivity of the inorganic particles at a wavelength of 250-440 nm is preferably 10% or less, 8% or less, and particularly preferably 5% or less. If the reflectance of the inorganic particles becomes large, it is difficult to irradiate the ultraviolet rays to the depth direction of the uncured resin composition sufficiently, and therefore the curability of the resin composition is likely to decrease.

Preferably, a buffer layer is provided on the surface of the inorganic particles. Thereby, it is easy to further suppress the light scattering generated at the interface between the inorganic particles and the curable resin, and further improve the light transmittance of the cured product. For example, the buffer layer is preferably a heterogeneous glass layer in which a part of inorganic particles is deteriorated and/or deformed. For example, the refractive index nd of the heterogeneous glass layer is preferably lower than the refractive index nd of the inorganic particles. In addition, the heterogeneous glass layer may be porous or moth-eye structured.

The buffer layer is preferably produced by acid treatment of inorganic particles. As a method of acid treatment, for example, it is preferable to adopt a method of immersing inorganic particles in an acid solution. Thereby, it is easy to uniformly form a buffer layer on the surface of the inorganic particles. In addition, an acid solution may be sprayed on the inorganic particles in a mist form. As the acid, for example, hydrochloric acid, dilute hydrochloric acid, nitric acid, sulfuric acid, etc. can be used.

The acid treatment time is preferably 10 minutes or more, 30 minutes or more, and particularly preferably 1 hour or more. Furthermore, it is preferably 30 hours or less, 25 hours or less, and particularly preferably 20 hours or less. If the acid treatment time is too short, the formation of the buffer layer is likely to become insufficient. If the acid treatment time is too long, the thickness of the buffer layer will easily become too large, which will reduce the light transmittance on the contrary.

The curing shrinkage rate of the resin composition is preferably 10% or less, 9% or less, 8% or less, 5% or less, 4% or less, and particularly preferably 3% or less. In this way, it is easy to reduce the difference in the size of the hardened product. The lower limit is not particularly limited, and is, for example, 0.5% or more.

Incidentally, when obtaining a cured product, it is necessary to take into account the shrinkage of the curable resin constituting the resin composition and design, but sometimes it does not shrink as designed to cause a dimensional difference. In the resin composition of the present invention, the amount of the curable resin is relatively reduced due to the addition of the above-mentioned inorganic particles, so it is easy to reduce the influence of the shrinkage of the resin composition. Therefore, the dimensional difference of the cured product obtained by curing the resin composition of the present invention is easily reduced.

Next, an example of the manufacturing method of the three-dimensional object of the present invention will be described. In addition, the resin composition is as described above, and the description is omitted here.

First, prepare an uncured layer containing an uncured resin composition. In more detail, a shaping table is installed in the tank filled with the uncured resin composition. At this time, position the shaping surface of the shaping table so that the distance from the surface of the uncured resin composition is the desired depth. The uncured layer is, for example, liquid or paste.

Secondly, light is selectively irradiated to the unhardened layer to form a hardened layer with a specific pattern. The hardened layer is formed on the molding surface.

Secondly, a new unhardened layer is formed on the hardened layer. That is, the uncured resin composition is introduced to the cured product layer again. For example, by moving the molding table by one layer, the uncured resin composition can be introduced onto the cured layer.

Secondly, irradiate light to form a new hardened layer with a specific pattern that is continuous with the hardened layer.

Repeat the above operations until a specific three-dimensional shape is obtained. In this way, the hardened layer is laminated to obtain the desired three-dimensional shape.

As such, regarding the resin composition of the present invention, the light transmittance of the inorganic particles contained in the resin composition at a wavelength of 405 nm is more than 10%, and the light transmittance to ultraviolet light is particularly excellent. Therefore, it is easy to fully irradiate ultraviolet rays to the depth direction of the uncured resin composition, and the curability is excellent when irradiated with ultraviolet rays. In addition, regarding the obtained cured product, since the difference in refractive index nd between the inorganic particles and the cured resin after curing is within ±0.1, the inorganic particles dispersed in the curable resin are not conspicuous, and the transparency is excellent. For example, the light transmittance T600 of the cured product at a wavelength of 600 nm can be set to 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, especially 75% or more. In addition, the light transmittance T500 of the cured product at a wavelength of 500 nm can be set to 20% or more, 30% or more, especially 40% or more.

The resin composition of the present invention can be preferably used as, for example, a resin composition for a three-dimensional object used in the production of a three-dimensional object, or a resin composition for a dentistry. As a dental resin composition, for example, it can be used for dental composite resin, dental bonding material, abutment building material, resin cement, glass ionomer cement, resin reinforced glass ionomer cement, CAD( Computer-aided design, computer-aided design)/CAM (Computer-aided manufacturing, computer-aided manufacturing) resin block, etc. Moreover, the resin composition of this invention can also be suitably used as a resin composition for optical members, etc., for example. [Example]

Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples.

Tables 1 and 3 show examples (No. 1 to 4, 7 to 9) and comparative examples (No. 5, 6) of the present invention. In addition, Table 2 shows the composition of glass used as inorganic particles.

[Table 1] Sample No. No.1 No.2 No.3 No.4 No.5 No.6 Inorganic particles type Glass A Glass A Glass A Glass A Glass B Glass C volume% 15 30 40 30 30 30 nd _g 1.51 1.51 1.51 1.51 1.63 1.57 νd _g 55 55 55 55 58 57 T405 84 84 84 84 88 8 T365 68 68 68 68 60 3 Hardening resin type Resin D Resin D Resin D Resin E Resin D Resin D volume% 85 70 60 70 70 70 Before hardening nd _rs 1.49 1.49 1.49 Not determined 1.49 1.49 After hardening nd _re 1.52 1.52 1.52 1.51 1.52 1.52 Before hardening νd _rs 47 47 47 51 47 47 |nd _g －nd _re | 0.01 0.01 0.01 0.01 0.11 0.05 |nd _g －nd _rs | 0.02 0.02 0.02 Not determined 0.14 0.08 |νd _g －νd _rs | 8 8 8 4 11 10 Hardening thickness (mm) 0.24 0.36 0.38 Not determined 0.17 0.12 Total light transmittance T600 (sample thickness: 1 mm) 85 80 76 67 55 17

[Table 2] (quality%) Glass A Glass B Glass C SiO ₂ 54.0 29.0 51.7 Al ₂ O ₃ 15.2 3.0 14.0 B ₂ O ₃ 16.2 24.0 7.0 MgO 0.5 CaO 2.0 25.0 SrO 6.0 BaO 4.5 ZnO 1.0 Li ₂ O 7.0 Na ₂ O 0.6 0.6 K ₂ O 3.0 0.1 TiO ₂ 1.0 0.6 Nb ₂ O ₅ 3.5 ZrO ₂ 3.2 La ₂ O ₃ 13.2 Gd ₂ O ₃ 10 F ₂ 0.3 WO ₃ 3.5 Fe ₂ O ₃ 0.15 NiO 0.01 Cr ₂ O ₃ 0.03 Sb ₂ O ₅ 0.1 Si＋Al＋B 85.4 56.0 72.7 Li＋Na＋K 3.6 7.0 0.7 Mg＋Ca＋Sr＋Ba＋Zn 3.0 6.0 25.5 Ti＋Nb＋W 8.0 0.0 0.6 Ti＋Nb＋W＋Si＋Al＋B 93.4 56.0 73.3 Li＋Na＋K＋Mg＋Ca＋Sr＋Ba＋Zn 6.6 13.0 26.2 (Li＋Na＋K)/(Si＋Al＋B) 0.042 0.125 0.010 (Mg＋Ca＋Sr＋Ba＋Zn)/(Si＋Al＋B) 0.035 0.107 0.351 nd 1.51 1.63 1.57 νd 55 58 57 T405 84 88 8 T365 68 60 3

[table 3] Sample No. No.7 No. 8 No.9 Inorganic particles type Glass A Glass A Glass A volume% 35 35 35 nd _g 1.51 1.51 1.51 νd _g 55 55 55 T405 84 84 84 T365 68 68 68 Hardening resin type Resin E Resin E Resin E volume% 65 65 65 Before hardening nd _rs - - - After hardening nd _re 1.51 1.51 1.51 Before hardening νd _rs 51 51 51 |nd _g －nd _re | 0.01 0.01 0.01 |nd _g －nd _rs | - - - |νd _g －νd _rs | 4 4 4 Acid treatment time (h) 1.5 18 0 Total light transmittance T600 (sample thickness: 2.5 mm) 42.1 41.4 40.9 Total light transmittance T500 (sample thickness: 2.5 mm) 40.7 40.1 39.4

(First embodiment) Examples (No. 1 to 4) and comparative examples (No. 5, 6) were produced as follows. First, raw materials were prepared so as to have the composition shown in Table 2, and glasses A, B, and C were produced. Glass A, B, and C were used to produce glass beads A, B, and C with an average particle diameter of 5 μm, and these were used as inorganic particles. Acrylic resins D and E are used as the curable resin. Next, inorganic particles were added to the curable resin at the ratio shown in Table 1, and kneaded with a three-roll mill to obtain an uncured resin composition in which inorganic particles were uniformly dispersed. The resin composition was poured into a 30 mm mold frame made of Teflon (registered trademark) to form a layer containing the uncured resin composition.

5 mm之區域5秒，於造形面上形成板狀之硬化物(即，板狀之立體造形物)。此時，測定所形成之立體造形物之硬化厚度。又，製作厚度1 mm之板狀之立體造形物，對表面進行鏡面研磨後，使用分光光度計(島津製作所製造之UV-3100)，測定厚度1 mm時於波長600 nm下之全光線透過率。For the obtained uncured layer, a point light source (LC8, manufactured by Hamamatsu Photonics) was ^{used to irradiate 4,500 mW/cm 2} of ultraviolet light to

For 5 seconds in a 5 mm area, a plate-shaped hardened object (ie, a plate-shaped three-dimensional object) is formed on the molding surface. At this time, the hardened thickness of the formed three-dimensional shape is measured. In addition, a plate-shaped three-dimensional object with a thickness of 1 mm is produced, and the surface is mirror-polished. Then, a spectrophotometer (UV-3100 manufactured by Shimadzu Corporation) is used to measure the total light transmittance at a wavelength of 600 nm at a thickness of 1 mm. .

The refractive index of the curable resin (nd _rs , nd _re ), the refractive index of glass (nd _g ), and the Abbe number (νd _g , ν _rs ) are measured by a precision refractometer (KPR-2000, Shimadzu Device) Determination.

The light transmittance of inorganic particles at wavelengths of 405 nm and 365 nm is based on the production of a plate-shaped sample with the same composition as the inorganic particles with a thickness of 1 mm±0.01 mm and mirror polishing on the surface, using a spectrophotometer (Shimadzu UV-3100 manufactured by the factory) was measured.

It can be seen from Table 1 that the total light transmittance T600 of the three-dimensional shapes of the examples (No. 1 to 4) at a wavelength of 600 nm is 67% or more. On the other hand, the T600 of the three-dimensional objects of the comparative examples (No. 5 and 6) is 55% or less, and the hardening thickness is as low as 0.17 mm or less. Especially the glass of No.6 sample is colored, the hardening thickness is small, 0.12 mm, and the value of T600 also becomes low.

(Second embodiment) Examples 7-9 were produced as follows. First, raw materials were prepared so as to have the composition shown in Table 2, and glass A was produced. Use glass A to make glass beads A with an average particle size of 5 μm. The glass beads A were immersed in 10% dilute hydrochloric acid, and the acid treatment time is shown in Table 3. The glass beads A'after the acid treatment are set as inorganic particles. Acrylic resin E is used as the curable resin. Next, the inorganic particles were added to the curable resin at the ratio shown in Table 3, and the mixture was kneaded with a three-roll mill to obtain an uncured resin composition in which the inorganic particles were uniformly dispersed.

5 mm之區域，獲得厚度2.5 mm之硬化物。對所獲得之硬化物之表面進行鏡面研磨後，使用分光光度計(V-670、日本分光公司製造之分光光度計)，測定厚度2.5 mm時於波長600 nm下之全光線透過率T600、及波長500 nm下之全光線透過率T500。將結果示於表3及圖1。For the obtained uncured resin composition, a point light source (LC8, manufactured by Hamamatsu Photonics) was ^{used to irradiate 4,500 mW/cm 2} of ultraviolet light to

In the area of 5 mm, a hardened product with a thickness of 2.5 mm is obtained. After mirror-polishing the surface of the obtained hardened object, use a spectrophotometer (V-670, a spectrophotometer manufactured by Japan Branch Co., Ltd.) to measure the total light transmittance T600 at a wavelength of 600 nm at a thickness of 2.5 mm, and The total light transmittance at a wavelength of 500 nm is T500. The results are shown in Table 3 and Fig. 1.

In Example 9, the glass beads A were not subjected to acid treatment, and a sample was prepared in the same manner as in Examples 7 and 8, except that the glass beads A were not treated with acid.

As shown in Table 3 and Figure 1, compared with the cured product of the example (No. 9) that was not acid-treated, the cured product of the example (No. 7, 8) that was acid-treated was at a wavelength of 600 nm The total light transmittance of T600, and the total light transmittance of T500 at a wavelength of 500 nm is higher.

Fig. 1 is a graph showing the light transmittance of the cured products of Example Nos. 7-9.

Claims (16)

A resin composition comprising a curable resin and inorganic particles, and The difference between the refractive index nd of the inorganic particles and the curable resin after curing is within ±0.1, The light transmittance of the above-mentioned inorganic particles at a wavelength of 405 nm is above 10%. The resin composition of claim 1, wherein the light transmittance of the above-mentioned inorganic particles at a wavelength of 405 nm is more than 50%. The resin composition of claim 1 or 2, wherein the above-mentioned inorganic particles have a light transmittance of 5% or more at a wavelength of 365 nm. The resin composition according to any one of claims 1 to 3, wherein the above-mentioned inorganic particles are glass. The resin composition of claim 4, wherein the glass contains 30 to 75% of SiO ₂ , 1 to 20% of Al ₂ O ₃ , 0 to 30% of B ₂ O ₃ , and 0 to 20% of Li ₂ O + Na ₂ O + K ₂ O, 0.1-20% of MgO + CaO + SrO + BaO + ZnO. The resin composition of claim 4 or 5, wherein the above-mentioned glass contains 40% or more of SiO ₂ + Al ₂ O ₃ + B ₂ O ₃ in terms of mass %. The resin composition according to any one of claims 1 to 6, wherein the average particle diameter of the above-mentioned inorganic particles is 0.2-50 μm. The resin composition according to any one of claims 1 to 7, which contains 1 to 90% of the above-mentioned inorganic particles by volume %. The resin composition according to any one of claims 1 to 8, wherein the Young's modulus of the above-mentioned inorganic particles is 50 GPa or more. The resin composition according to any one of claims 1 to 9, wherein the thermal expansion coefficient of the above-mentioned inorganic particles is 60×10 ^-7 /°C or less at 30 to 100°C. The resin composition according to any one of claims 1 to 10, wherein the light reflectance of the above-mentioned inorganic particles at a wavelength of 250 to 440 nm is 10% or less. The resin composition according to any one of claims 1 to 11, wherein the surface of the above-mentioned inorganic particles has a buffer layer. The resin composition of claim 12, wherein the refractive index nd of the buffer layer is lower than the refractive index nd of the inorganic particles. A resin composition for three-dimensional shaped objects, which uses the resin composition according to any one of claims 1 to 13. A resin composition for dentistry using the resin composition according to any one of claims 1 to 13. A method for manufacturing a three-dimensional shaped object, which selectively irradiates an unhardened layer containing an unhardened resin composition with light to form a hardened layer with a specific pattern, and forms a new unhardened layer on the hardened layer After layering, irradiate the light to form a new hardened layer with a specific pattern that is continuous with the hardened layer, and repeat the layering of the hardened layer until a specific three-dimensional shape is obtained; and The resin composition according to any one of claims 1 to 13 is used as the resin composition.

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