JP2018030278A - Three-dimensional molding apparatus and method for manufacturing three-dimensional molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that in a three-dimensional molding apparatus for forming a three-dimensional molded object by stacking a plurality of layers formed by a photo-curing process, it is difficult to quickly supply a liquid resin material for forming the subsequent layer after one layer is formed, and thereby, much time is required for three-dimensional molding.SOLUTION: A surface of a light-transmitting window to be in contact with a liquid resin material is subjected to a hydrophilic treatment, which reduces flow resistance of a liquid photo-curable resin and allows quick supply of the liquid resin material for forming the subsequent layer. Thus, time required for forming a three-dimensional molded object can be significantly reduced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-dimensional modeling apparatus that manufactures a three-dimensional structure by projecting an exposure image onto a photocurable liquid resin material.

  In recent years, expectations for so-called 3D printers have increased. In particular, the development of a device for producing a three-dimensional structure by projecting an exposure image onto a photocurable liquid resin material is actively performed.

  For example, in Patent Document 1, a liquid photocurable resin is accommodated in a container whose upper surface is opened, and a resin cured layer is formed by irradiating light from above the free liquid surface and photocuring in the vicinity of the free liquid surface. An apparatus is disclosed. In such an apparatus, after the resin cured layer is formed, the moving table that supports the resin cured layer is lowered, and waits until the depth from the liquid surface of the liquid photocurable resin to the resin cured layer reaches a predetermined depth. Then, the resin cured layer is laminated by irradiating light again. Such a process was repeated to form a three-dimensional structure.

  Patent Document 2 discloses an apparatus for forming a resin-cured layer having a desired shape by making a bottom of a container filled with a liquid photocurable resin material light-transmissive and projecting an exposure image onto the resin through the bottom. It is disclosed. In such an apparatus, when one cured resin layer is formed, the modeled object is lifted, and a liquid photocurable resin is poured between the modeled object and the bottom of the container to replenish, and when the replenishment is completed, the next exposure image is displayed. The resin cured layer is laminated by projecting. Such a process was repeated to form a three-dimensional structure.

  In the case of the apparatus of Patent Document 2, since light is irradiated through the bottom of the container, there is an advantage that even if the liquid level of the resin fluctuates, the optical exposure conditions are not affected.

Japanese Patent Laid-Open No. 5-96632 US Patent Application Publication No. 2015/54198

  By the way, there is an increasing demand for a 3D printer to increase the modeling speed from the industry, and a method of using a photocurable liquid resin material as a raw material is no exception.

  Generally, the thickness of a cured layer formed by irradiating light to a photocurable liquid resin material is about 0.02 mm to 0.2 mm per layer. In order to increase the three-dimensional modeling speed, it is important how to complete a preparation process for forming the next cured layer in a short time after forming a single cured layer. In other words, it is important how to supply the next one layer of liquid resin material to the modeling region at high speed. This is because a photocurable liquid resin material generally has a high viscosity and thus takes a long time to flow.

  In particular, when forming a large three-dimensional structure, the area of the modeling region is increased, and therefore the time required for replenishing the photocurable liquid resin material for forming the next layer is increased. Further, as the number of layers to be stacked increases, the number of times of replenishment increases accordingly, and the time required to complete the three-dimensional structure becomes longer.

  In the case of the apparatus of Patent Document 1, in order to increase the speed at which the liquid resin material is replenished to the modeling region, the liquid resin material is devised to increase the fluidity by applying ultrasonic vibration. However, since the apparatus of Patent Document 1 is an apparatus system that irradiates light from above the free liquid surface of the resin, if the liquid level fluctuates, the optical exposure conditions are likely to be affected. If the fluidity of the liquid resin material is increased to shorten the replenishment time, there may be a problem with the shape accuracy of the cured layer.

  In the case of the apparatus of Patent Document 2, since light is irradiated through the bottom of the container as described above, there is an advantage that even if the liquid level of the resin fluctuates, the optical exposure conditions are not affected.

  On the other hand, when lifting the cured layer to prepare for the next layer formation, the gap between the bottom of the container and the cured layer is narrow, so the conductance is small and it takes time to replenish the liquid resin material from the surroundings. was there.

  In order to solve this problem, attempts have been made to use a liquid resin material having a low viscosity, but the shrinkage at the time of solidification is increased, resulting in deformation of the molded article, and sufficient strength without increasing the degree of polymerization at the time of photocuring. Cannot be obtained or the heat resistance is lowered. As a post-processing step of modeling by photocuring, a post-cure method in which the strength is improved by applying light or heat has been attempted, but there has been a problem of deterioration in dimensional accuracy and deformation.

  Also, attempts have been made to increase the temperature of the entire liquid resin material filled in the container to increase the fluidity, but the resin material deteriorates or hardens due to heat, and the molded object is cooled by cooling after solidification. There was a problem of deformation.

  For this reason, when laminating a plurality of layers to form a three-dimensional structure, there has been a demand for a method of quickly replenishing the modeling region without deteriorating the liquid resin material for layer formation.

  The present invention includes a container that holds a liquid photocurable resin, a base that supports a solid shaped article obtained by photocuring the liquid photocurable resin, and a moving unit that moves the base. A light source unit that emits light for photocuring the liquid photocurable resin; and a light transmission window that is provided between the light source unit and the base and is in contact with the liquid photocurable resin. The transmission window is a three-dimensional modeling apparatus characterized by having a hydrophilic surface in a region in contact with the liquid photocurable resin.

  The present invention also includes a container that holds a liquid photocurable resin, a base that supports a solid shaped article obtained by photocuring the liquid photocurable resin, and a moving unit that moves the base. A light source unit that emits light for photocuring the liquid photocurable resin, and a light transmission window that is provided between the light source unit and the base and is in contact with the liquid photocurable resin. A method of manufacturing a three-dimensional structure using a three-dimensional modeling apparatus, wherein after the light source unit emits light and a part of the liquid photocurable resin held in the container is photocured, The liquid photocurable resin is moved between the light transmissive window and the solid shaped article while moving the base and bringing the liquid photocurable resin into contact with the hydrophilic surface provided on the light transmissive window. In a method for manufacturing a three-dimensional structure, That.

  According to the present invention, when a plurality of layers are stacked to form a three-dimensional structure, the liquid resin material for layer formation can be quickly replenished in the modeling region without deteriorating. Therefore, the time required for forming the three-dimensional structure can be significantly shortened.

Sectional drawing of 1st embodiment. The block diagram of 1st embodiment. (A) A photograph of a droplet experiment of Example 1, (b) a photograph of a droplet experiment of Comparative Example 1, and (c) a photograph of a droplet experiment of Comparative Example 2. Sectional drawing of 2nd embodiment.

  Embodiments of the present invention will be described with reference to the drawings.

  In the following description, a liquid photocurable resin that is not solidified is referred to as a liquid photocurable resin. Moreover, the solid modeling thing which photocured liquid photocurable resin is described as a three-dimensional modeling thing. The three-dimensional structure is not limited to a finished product, but also refers to a semi-finished product in which all layers are stacked up to an intermediate layer.

  The hydrophilic surface indicates a surface state that exhibits hydrophilicity if the surface is brought into contact with water. That is, it represents the surface characteristics, and does not mean that the surface comes into contact with water in the usage state of the apparatus.

[First embodiment]
FIG. 1 is a diagram schematically showing a cross section of the apparatus for explaining the structure of the three-dimensional modeling apparatus according to the first embodiment of the present invention.

(Device configuration)
In FIG. 1, 1 is a container, 2 is a liquid photocurable resin, 3 is a resin supply unit, 4 is a light transmission window, 5 is a light shielding unit, 6 is a hydrophilic surface unit, 7 is a light source, 8 is a mirror unit, 9 Is a lens unit, 10 is a light source unit, 11 is a base, 12 is a lifting arm, 13 is a lifting unit, and 14 is a three-dimensional structure.

  The container 1 is a container for holding the liquid photocurable resin 2, and is formed of a material that blocks light in a wavelength region that solidifies the liquid photocurable resin.

  The resin supply unit 3 includes a tank and a pump for storing the liquid photocurable resin, and supplies the liquid photocurable resin so that an appropriate amount of the liquid photocurable resin 2 is held in the container 1.

  The liquid photocurable resin 2 is a liquid resin that is cured (solidified) when irradiated with light in a specific wavelength range. The liquid photocurable resin 2 is filled in the container 1 up to the lower surface of the light transmission window 4 and the light shielding portion 5 and is held so that bubbles do not enter. The light transmission window 4 and the light shielding part 5 function as a lid of the container 1 and can be opened and closed.

  The light transmission window 4 is a window that transmits light in a wavelength region that solidifies the liquid photocurable resin 2 and is, for example, a glass plate. The light-shielding part 5 is a part made of a member that shields light in a wavelength region that solidifies the liquid photocurable resin 2. In the present embodiment, the light transmission window 4 is provided in a portion that functions as a lid and the light path between the light source unit 10 and the base 11 and the light shielding portion 5 is formed in other regions. When unnecessary light does not enter from outside the apparatus, the entire lid may be made of the same material as the light transmission window.

  On the lower surface of the light transmission window 4, a UV light-transmitting hydrophilic surface portion 6 described later is provided.

  The light source 7, the mirror unit 8, and the lens unit 9 constitute a light source unit 10 for irradiating the liquid photocurable resin with light corresponding to the shape of the three-dimensional model to be modeled. The light source 7 is a light source that emits light in a wavelength region that solidifies the liquid photocurable resin. For example, when a material having sensitivity to ultraviolet light is used as the photocurable resin, an ultraviolet light source such as a He—Cd laser or an Ar laser is used. The mirror unit 8 is a part that modulates the light emitted from the light source 7 in correspondence with the shape of the three-dimensional model to be modeled, and a device in which micromirror devices are arranged in an array is used. The lens unit 9 is a lens for condensing the modulated light onto the liquid photocurable resin 2 located at a predetermined position below the light transmission window 4. The liquid photocurable resin 2 in a predetermined position is cured when irradiated with a condensed ultraviolet light having a sufficient intensity.

  In order to ensure the accuracy of the shape of the cured product, it is desirable that the focal position of the condenser lens is in the vicinity of the light transmission window, but if it is too close, the cured resin may adhere to the light transmission window 4. There is. Therefore, it is desirable that the focal position of the lens unit 9 is set 60 μm to 110 μm below the lower surface of the light transmission window 4.

  The light source unit 10 may have any function for modulating the light in the wavelength region for solidifying the liquid photocurable resin in accordance with the shape of the three-dimensional model to be modeled and condensing it at a predetermined position. However, the present invention is not limited to the above example. For example, a combination of an ultraviolet light source and a liquid crystal shutter, a semiconductor laser diode array, a scanning mirror, an imaging mirror, or the like may be used.

  The base 11 is a table that supports the three-dimensional structure 14 placed on the upper surface thereof, and is connected to the lifting unit 13 via the lifting arm 12. The elevating unit 13 is a mechanism that adjusts the height of the base 11 by moving the elevating arm 12 up and down, and is a moving unit that moves the base.

  FIG. 2 is a block diagram of the three-dimensional modeling apparatus. 21 is a control unit, 22 is an external device, 23 is an operation panel, 3 is a resin supply unit, 10 is a light source unit, and 13 is an elevating unit.

  The control unit 21 includes a CPU, a ROM which is a non-volatile memory storing a control program and a numerical value table for control, a RAM which is a volatile memory used for calculation, an I / O port for communicating with each unit of the device, and the like. I have. The ROM stores a program for controlling basic operations of the three-dimensional modeling apparatus.

  From the external device 22, the shape data of the three-dimensional structure is input to the control unit 21 of the three-dimensional structure apparatus via the I / O port.

  The operation panel 23 includes an input unit for an operator of the 3D modeling apparatus to give an instruction to the apparatus and a display unit for displaying information to the operator. The input unit includes a keyboard and operation buttons. The display unit includes a display panel that displays an operation status of the three-dimensional modeling apparatus.

  The control unit 21 controls the resin supply unit 3, the light source unit 10, and the elevating unit 13 to execute a three-dimensional modeling process.

(Three-dimensional modeling process)
Next, a three-dimensional modeling process using the above three-dimensional modeling apparatus will be described.

  First, the control unit 21 confirms whether a predetermined amount of the liquid photocurable resin is accommodated in the container 1 using a sensor (not shown). When the amount is insufficient, the resin supply unit 3 is operated to fill the container 1 with a predetermined amount of the liquid photocurable resin 2.

  Next, the control unit 21 operates the elevating unit 13 to set the position of the base 11 so that the height of the upper surface of the base 11 is slightly below the focal position of the light source unit 10. For example, when the thickness of one layer when forming a three-dimensional structure by layered modeling is 40 μm, the top surface of the base 11 is adjusted to be 10 μm to 30 μm below the focal position.

  The control unit 21 creates shape data (slice data) of each layer used in the additive manufacturing process based on the 3D modeling model shape data input from the external device 22.

  Then, the light source unit 10 is driven to emit light, and the liquid photocurable resin 2 is irradiated with ultraviolet light modulated based on the shape data of the first layer of the three-dimensional structure. The liquid photocurable resin 2 at the irradiated site is cured, and the first layer portion of the three-dimensional structure is formed on the base 11.

  Next, as preparation for forming the second layer, the control unit 21 operates the elevating unit 13 to lower the base 11 on which the first layer portion is formed by 40 μm. The liquid photocurable resin 2 flows from the surroundings into the space between the descending base 11 and the light transmission window 4.

  According to the present invention, the flow resistance of the liquid photocurable resin 2 is reduced because the lower surface of the light transmission window 4, that is, the surface in contact with the liquid photocurable resin 2 is subjected to a hydrophilic surface treatment. . For this reason, the inflow speed of the liquid photocurable resin 2 is fast, and it is possible to shorten the time required for the preparation process for forming the second layer. That is, when manufacturing a three-dimensional structure, after light-curing a part of the liquid photocurable resin held in the container by causing the light source unit to emit light, the liquid photocurable resin is passed through the light transmission window. It is replenished at high speed while making contact with the hydrophilic surface provided on the surface.

  At the timing when the inflow of the liquid photocurable resin 2, that is, the replenishment is completed, the control unit 21 drives the light source unit 10 to generate the ultraviolet light modulated based on the shape data of the second layer of the three-dimensional structure. Irradiate. The liquid photocurable resin 2 at the irradiated portion is cured, and the second layer portion is laminated on the first layer of the three-dimensional structure.

  Hereinafter, by repeating the same process, it is possible to laminate a large number of layers and form a three-dimensional structure having a desired shape.

  According to the present invention, by applying a UV light-transmitting hydrophilic treatment to the lower surface of the light-transmitting window, the injection of the liquid photocurable resin for forming the next layer can be speeded up. Since the time required to form a three-dimensional structure varies depending on the size and shape of the structure, the type of liquid photocurable resin used, the temperature, etc., the time reduction effect according to the present invention is expressed as a universal numerical value. It is difficult. Therefore, a relative comparison was made between the present invention and an apparatus not implementing the present invention.

Example 1
The glass substrate surface was subjected to hydrophilic treatment by depositing a UV light transmissive hydrophilic film made of calcium phosphate ceramic on a UV transmissive glass substrate, and then used as the light transmissive window 4.

  As a hydrophilic treatment, a resin film having a high affinity with a liquid photocurable resin can be applied in advance, but a film made of calcium phosphate ceramics is highly permeable to UV light and excellent in durability. Therefore, it is a suitable material for carrying out the present invention.

First, a pre-cleaned UV transparent glass substrate is set in a vacuum vapor deposition apparatus and heated to 50 ° C. Then, an underlayer having a thickness of 10 nm was deposited at a deposition rate of 2 angstroms / second. Next, while introducing 1.2 × 10 ⁻² Pa of oxygen, the calcium phosphate electron gun was driven at a vacuum level of 2 × 10 ⁻³ Pa or less at a total pressure of 100 nm at a deposition rate of 2 Å / sec. A thick calcium phosphate ceramic layer was deposited.

  This ceramic layer can transmit UV light with little attenuation.

(Comparative Example 1)
The surface of the UV transparent glass substrate was water-repellent coated with a fluorine-type coating material and used as the light transmission window 4.

(Comparative Example 2)
A UV transparent glass substrate whose surface was washed with an organic solvent and pure water was used as the light transmission window 4.

  First, an experiment was conducted in which a liquid photocurable resin was dropped onto the glass substrates of Example 1, Comparative Example 1, and Comparative Example 2 to observe the droplet shape. The glass substrate is dropped upside down from the time when it is set in the apparatus of FIG. 1 as the light transmission window 4, and 100 microliters of urethane acrylate is dropped in an environment of 21.8 degrees C. on the substrate. The shape was observed when the droplet was stabilized.

  FIGS. 3A, 3B, and 3C are photographs of experiments in which the droplet shapes of Example 1, Comparative Example 1, and Comparative Example 2 are observed from the side, respectively. Table 1 shows the droplet shape measurement results.

In Table 1, the droplet height is the height from the glass substrate surface to the top of the droplet. The droplet diameter is the diameter of the droplet when the glass substrate is viewed from above.

  As is clear from FIG. 3 and Table 1, in the glass substrate of Example 1, the liquid photocurable resin droplets are flat compared to the glass substrates of Comparative Example 1 and Comparative Example 2. By coating a hydrophilic film made of calcium phosphate-based ceramics, it can be said that the affinity between the substrate surface and the liquid photocurable resin is increased, and the droplet shape is flattened.

  Next, the glass substrates of Example 1, Comparative Example 1, and Comparative Example 2 were used as the light transmissive window 4 of the three-dimensional modeling apparatus in FIG. 1, and all were under the same conditions except that the light transmissive windows were different. Three-dimensional modeling was performed and the time required for modeling was compared.

  When the light transmission window of Example 1 is used, since the hydrophilic surface treatment is performed, the flow resistance of the liquid photocurable resin 2 is reduced as compared with Comparative Example 1 and Comparative Example 2, and the base is lowered. It was confirmed that the inflow rate of the photocurable resin solution was about 15% to 25% faster. For example, when forming a three-dimensional object having a number of layers of 750, a bottom surface of 5 cm × 5 cm, and a height of about 30 mm, the time required for three-dimensional modeling including the photocuring process is compared with Comparative Example 1 in Example 1. It was about 60% shorter than that of Comparative Example 2 by about 40%.

[Second Embodiment]
FIG. 4 is a diagram schematically showing a cross section of the apparatus for explaining the structure of the three-dimensional modeling apparatus according to the second embodiment of the present invention.

(Device configuration)
In the first embodiment, the light transmission window functions as a lid of the container. However, in the second embodiment, the light transmission window is provided at the bottom of the container. In the first embodiment, a highly confidential material such as a glass plate is used as a material for the light transmission window. However, in the second embodiment, for example, a material having a property of transmitting a gas such as oxygen. In that gas is supplied to the liquid photocurable resin in the vicinity of the light transmission window through the light transmission window. When a radically polymerizable resin material that decreases the photocuring sensitivity when containing a gas such as oxygen, for example, is used as the liquid photocurable resin, a region where curing is inhibited is formed in the vicinity of the light transmitting window. There is an advantage that the cured product does not adhere to.

  In FIG. 4, 1 is a container, 2 is a liquid photocurable resin, 3 is a resin supply part, 44 is a light transmission window, 5 is a light shielding part, 46 is a hydrophilic surface part, 7 is a light source, 8 is a mirror part, 9 Is a lens unit, 10 is a light source unit, 11 is a base, 12 is a lifting arm, 13 is a lifting unit, and 14 is a three-dimensional structure.

  The container 1 is a container for holding the liquid photocurable resin 2, and is formed of a material that blocks light in a wavelength region that solidifies the liquid photocurable resin.

  The resin supply unit 3 includes a tank and a pump for storing the liquid photocurable resin, and supplies the liquid photocurable resin so that an appropriate amount of the liquid photocurable resin 2 is held in the container 1.

  The liquid photocurable resin 2 is a liquid resin that is cured (solidified) when irradiated with light in a specific wavelength range.

  The light transmission window 4 is a window that transmits light in a wavelength range that solidifies the liquid photocurable resin 2 and transmits gas that inhibits the curing of the liquid photocurable resin. For example, a resin such as PFA, PTFE, and PE It consists of a plate made of

  The liquid photocurable resin in the vicinity of the light transmission window 4 is reduced in photocuring sensitivity by the action of the curing inhibiting gas that has passed through the light transmission window 44. Since the gas exhibiting the curing inhibiting action is, for example, oxygen, it is sufficient that normal air exists outside the light transmission window 44. However, in order to make the action of gas more effective, a mechanism for controlling the composition and pressure of the outside air of the light transmission window may be provided.

  On the upper surface of the light transmission window 4, a UV light-transmitting hydrophilic surface portion 46 described later is provided.

  The light-shielding part 5 is a part made of a member that shields light in a wavelength region that solidifies the liquid photocurable resin 2.

  The light source 7, the mirror unit 8, and the lens unit 9 constitute a light source unit 10 that irradiates the liquid photocurable resin with light corresponding to the shape of the three-dimensional model to be modeled. The light source 7 is a light source that emits light in a wavelength region that solidifies the liquid photocurable resin. For example, when a material having sensitivity to ultraviolet light is used as the photocurable resin, an ultraviolet light source such as a He—Cd laser or an Ar laser is used. The mirror unit 8 is a part that modulates the light emitted from the light source 7 in correspondence with the shape of the three-dimensional model to be modeled, and a device in which micromirror devices are arranged in an array is used. The lens unit 9 is a lens for condensing the modulated light onto the liquid photocurable resin 2 located at a predetermined position below the light transmission window 4. The liquid photocurable resin 2 at a predetermined position is cured by being irradiated with sufficiently intense ultraviolet light.

  In order to ensure the accuracy of the shape of the cured product, it is desirable that the focal position of the condensing lens is in the vicinity of the light transmission window, but if it is too close, there is a possibility of overlapping with a region where curing is inhibited by the gas. Therefore, it is desirable that the focal position of the lens unit 9 is set 60 μm to 110 μm above the upper surface of the light transmission window 4.

  The light source unit 10 may be any unit that has a function of modulating light in a wavelength region for solidifying the liquid photocurable resin in accordance with the shape of the three-dimensional model to be modeled and condensing it at a predetermined position. However, the present invention is not limited to the above example. For example, a combination of an ultraviolet light source and a liquid crystal shutter, a semiconductor laser diode array, a scanning mirror, an imaging mirror, or the like may be used.

  The base 11 is a base that supports the three-dimensional structure 14 by suspending it on the lower surface thereof, and is connected to the lift unit 13 via the lift arm 12. The elevating unit 13 is a mechanism that adjusts the height of the base 11 by moving the elevating arm 12 up and down, and is a moving unit that moves the base.

  Since the block diagram of the three-dimensional modeling apparatus of the second embodiment is generally the same as FIG. 2 described in the first embodiment, the description thereof is omitted.

(Three-dimensional modeling process)
Next, a three-dimensional modeling process using the three-dimensional modeling apparatus of the second embodiment will be described.

  First, the control unit 21 confirms whether a predetermined amount of the liquid photocurable resin is accommodated in the container 1 using a sensor (not shown). When the amount is insufficient, the resin supply unit 3 is operated to fill the container 1 with a predetermined amount of the liquid photocurable resin 2.

  Next, the control unit 21 operates the elevating unit 13 to set the position of the base 11 so that the position of the lower surface of the base 11 is slightly above the focal point of the light source unit 10. For example, when the thickness of one layer when forming a three-dimensional structure by layered modeling is 40 μm, the bottom surface of the base 11 is adjusted to be 10 μm to 30 μm above the focal position.

  The control unit 21 creates shape data (slice data) of each layer used in the additive manufacturing process based on the 3D modeling model shape data input from the external device 22.

  The control unit 21 drives the light source unit 10 to emit ultraviolet light modulated based on the shape data of the first layer of the three-dimensional structure. The liquid photocurable resin 2 at the irradiated site is cured, and the first layer portion of the three-dimensional structure is formed on the lower surface of the base 11.

  Next, as preparation for forming the second layer, the control unit 21 operates the elevating unit 13 to raise the base 11 on which the first layer portion is formed by 40 μm. The liquid photocurable resin 2 flows from the surroundings into the space between the rising base 11 and the light transmission window 44.

  According to the present invention, the flow resistance of the liquid photocurable resin 2 is reduced because the upper surface of the light transmission window 4, that is, the surface in contact with the liquid photocurable resin 2 is subjected to a hydrophilic surface treatment. . For this reason, the inflow speed of the liquid photocurable resin 2 is fast, and it is possible to shorten the time required for the preparation process for forming the second layer.

  At the timing when the inflow of the liquid photocurable resin 2 is completed, the control unit 21 drives the light source unit 10 based on the shape data of the second layer of the three-dimensional structure, and is modulated based on the shape data. Irradiate with ultraviolet light. The liquid photocurable resin 2 at the irradiated portion is cured, and a second layer portion is laminated and formed under the first layer of the three-dimensional structure.

  Hereinafter, by repeating the same process, it is possible to laminate a large number of layers and form a three-dimensional structure having a desired shape.

  According to the present invention, by applying a hydrophilic treatment to the lower surface of the light transmission window, the injection of the liquid photocurable resin for forming the next layer can be speeded up. Since the time required to form a three-dimensional structure varies depending on the size and shape of the structure, the type of liquid photocurable resin used, the temperature, etc., the time reduction effect according to the present invention is expressed as a universal numerical value. It is difficult. Therefore, the present invention was compared with a non-implemented apparatus.

(Example 2)
A UV light permeable hydrophilic film made of calcium phosphate ceramics was deposited on a UV permeable and gas permeable PFA substrate, and the surface was subjected to hydrophilic treatment, and then used as a light transmissive window 44.

First, a pre-cleaned PFA substrate is set in a vacuum deposition apparatus and heated to 50 degrees C. Then, an underlayer having a thickness of 10 nm was deposited at a deposition rate of 2 angstroms / second. Next, while introducing 1.2 × 10 ⁻² Pa of oxygen, the calcium phosphate electron gun was driven at a vacuum level of 2 × 10 ⁻³ Pa or less at a total pressure of 100 nm at a deposition rate of 2 Å / sec. A thick calcium phosphate ceramic layer was deposited.

  This ceramic layer can transmit UV light with almost no attenuation, and can transmit gas such as oxygen and ozone.

(Comparative Example 3)
The surface of the PFA substrate having UV transparency and gas permeability was washed with an organic solvent and pure water and used as the light transmission window 44.

  First, an experiment was conducted in which a liquid photocurable resin was dropped onto the PFA substrates of Example 2 and Comparative Example 3 to observe the droplet shape. The PFA substrate is turned upside down from when it is set in the apparatus of FIG. 4 as the light transmission window 44, and 100 microliters of urethane acrylate is dropped in an environment of 21.8 degrees C. on the substrate. The shape was observed when the droplet was stabilized.

  Table 2 shows the measurement results of the droplet shape.

In Table 2, the droplet height is the height from the glass substrate surface to the top of the droplet. The droplet diameter is the diameter of the droplet when the glass substrate is viewed from above.

  As is clear from Table 2, in the PFE substrate of Example 2, the liquid photocurable resin droplets are flat compared to the PFE substrate of Comparative Example 3. By coating a hydrophilic film made of calcium phosphate-based ceramics, it can be said that the affinity between the substrate surface and the liquid photocurable resin is increased, and the droplet shape is flattened.

  Furthermore, in addition to urethane acrylate, the liquid photocurable resin 2 was also tested for acrylic acrylate and polyester acrylate. In both cases, the PFE substrate of Example 2 was more liquid droplets than the PFE substrate of Comparative Example 3. Was found to flatten.

  Table 3 shows the droplet shapes observed on the PFE substrate of Example 2 for the three types of liquid photocurable resins.

Next, the PFE substrate of Example 2 and Comparative Example 3 is used as the light transmission window 44 of the three-dimensional modeling apparatus in FIG. 4, and three-dimensional modeling is performed under the same conditions except that the light transmission window is different. The time required was compared.

  When the light transmission window of Example 2 is used, since the hydrophilic surface treatment is performed, the flow resistance of the liquid photocurable resin 2 is reduced as compared with Comparative Example 3, and the light when the base is raised. It was confirmed that the inflow rate of the curable resin solution was about 20% faster. As a result, for example, when forming a three-dimensional object having a number of layers of 750, a bottom surface of 5 cm × 5 cm, and a height of about 30 mm, the time required for three-dimensional modeling including the photocuring process is shown in Example 2 as a comparative example. It was about 55% shorter than 3.

[Other Embodiments]
In the first embodiment, the light transmission window is disposed on the top of the container, and in the second embodiment, the light transmission window is disposed on the bottom surface of the container. The arrangement of the light transmission window subjected to the hydrophilic surface treatment of the present invention is not limited to these examples. For example, the light transmission window may be arranged on the side surface of the container and light may be incident from the side of the container. In that case, the base may be moved in the horizontal direction instead of the vertical direction to adjust the distance from the light transmission window.

  In any of these arrangements, a highly confidential window material as in the first embodiment or a gas permeable window material as in the second embodiment can be used.

  Further, in the first embodiment and the second embodiment, the light transmission window 4 is provided in a portion that becomes an optical path between the light source unit 10 and the base 11, and the hydrophilic surface treatment is performed only on this portion. A hydrophilic surface treatment may also be performed on the peripheral region of the portion that becomes the optical path.

  DESCRIPTION OF SYMBOLS 1 ... Container / 2 ... Liquid photocurable resin / 3 ... Resin supply part / 4 ... Light transmission window / 6 ... Hydrophilic surface part / 10 ... Light source unit / 11. ..Base / 12 ... Lifting arm / 14 ... Three-dimensional structure / 44 ... Light transmission window / 46 ... Hydrophilic surface part

Claims (6)

A container for holding a liquid photocurable resin;
A base for supporting a solid shaped article obtained by photocuring the liquid photocurable resin;
A moving unit for moving the base;
A light source unit that emits light for photocuring the liquid photocurable resin;
A light transmission window provided between the light source unit and the base, and in contact with the liquid photocurable resin;
The light transmission window has a hydrophilic surface in a region in contact with the liquid photocurable resin.
A three-dimensional modeling apparatus characterized by this. The hydrophilic surface is a surface of a calcium phosphate ceramic.
The three-dimensional modeling apparatus according to claim 1. The light transmission window is a light transmission window provided with a hydrophilic surface on a confidential glass substrate.
The three-dimensional modeling apparatus according to claim 1 or 2, characterized in that The light transmission window is a light transmission window provided with a hydrophilic surface on a gas permeable substrate.
The three-dimensional modeling apparatus according to claim 1 or 2, characterized in that A container for holding a liquid photocurable resin;
A base for supporting a solid shaped article obtained by photocuring the liquid photocurable resin;
A moving unit for moving the base;
A light source unit that emits light for photocuring the liquid photocurable resin;
A method for producing a three-dimensional structure using a three-dimensional structure forming apparatus provided between the light source unit and the base and having a light transmission window in contact with the liquid photocurable resin,
After light-curing a part of the liquid photocurable resin held in the container by emitting light from the light source unit,
The liquid photocurable resin is moved between the light transmissive window and the solid shaped article while moving the base and bringing the liquid photocurable resin into contact with the hydrophilic surface provided on the light transmissive window. Replenish in between,
A method for producing a three-dimensional structure characterized by that. Gas is supplied to the liquid photocurable resin in contact with the light transmissive window through the light transmissive window.
The manufacturing method of the three-dimensional structure according to claim 5.