JPH0452044Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to an apparatus used in an optical modeling method for manufacturing a cured body of a desired shape by irradiating a photocurable resin with light. Specifically, the present invention relates to an optical modeling device configured to irradiate light from a light-transmitting window provided in a container toward a photocurable resin inside the container. [Prior art] A photocurable resin is irradiated with a light beam to cure the irradiated portion, and this cured portion is continued in the horizontal direction, and a photocurable resin is further supplied above it and cured in the same manner. An optical modeling method in which the cured body is made to continue in the vertical direction by repeating this process to produce a cured body in the desired shape was developed in Japanese Patent Application Laid-open No.
It is publicly known from No. 60-247515, No. 62-35966, No. 62-101408, etc. A method of using a mask instead of scanning the light beam is also known. Such an optical modeling method includes a container having a light-transmitting window on the bottom or side surface, a device for irradiating light into the container through the light-transmitting window, and a device movable within the container in a direction away from the light-transmitting window. Some have a base that is This optical modeling method will be explained with reference to FIG. In FIG. 1, a photocurable resin 12 is housed in a container 11. As shown in FIG. A light transmitting window 13 made of a light transmitting plate such as quartz glass is provided on the bottom surface of the container 11, and a light emitting section 15 having a built-in lens is provided so as to irradiate a light beam 14 toward the light transmitting window 13. , the optical fiber 16 and the light emitting part 15 in the horizontal plane
An optical system (irradiation device) including an X-Y moving device 17 for moving in the Y direction (X, Y are two orthogonal directions), a light source 20, etc. is provided. A base 21 is installed inside the container 11, and the base 21 can be raised and lowered by an elevator 22. These moving device 17 and elevator 22 are controlled by a computer 23. When producing a cured body using the above-mentioned apparatus, first, the base 21 is positioned slightly above the light-transmitting window 13, and the light beam 14 is scanned along the horizontal cross section of the target object. This scanning was performed using a computer controlled X
- carried out by the Y moving device 17; After irradiating the entire horizontal cross section of the target shape (in this case, the portion corresponding to the bottom or top surface), the base 21 is slightly raised, and the cured material (cured layer) 24 and transparent window 21 are exposed. After flowing an uncured photocurable resin during this period, the same light irradiation as above is performed. By repeating this procedure, a cured product having the desired shape can be obtained as a multilayer laminate. In the optical modeling apparatus described above, it is necessary that the cured material 24 separates from the transparent window 13 when the base 21 is pulled up. That is, if the cured product 24 is peeled off from the base 21, the modeling process cannot be continued. For this reason, conventionally, a resin coating film 30 such as fluororesin is formed on the surface of the light-transmitting window 13 on the inner surface of the container. This resin coating film 30 has low adhesion (compatibility) with the cured product 24 made of a photocurable resin, and when the base 21 is pulled up, the cured product 24 is easily peeled off from the light-transmitting window 13. is always attached to and held on the base 21. Conventionally, polytetrafluoroethylene (PTFE) has been mainly used as the fluororesin for the resin coating film 30. [Problems to be Solved by the Invention] The following characteristics are desired for the resin coating film 30 formed on the inner surface of the container of the light-transmitting window of the optical shaping device. The adhesive force or adhesion force with the cured material 24 is small. That is, when the base 21 is pulled up, the cured product 24
Since the resin coating film 30 and the resin coating film 30 need to be easily separated, the adhesive force F ₁ between the resin coating film 30 and the transparent window 13, the adhesive force F ₂ between the resin coating film 30 and the cured product 24, and , the relationship F ₃ >F ₂ F ₁ >F ₂ needs to hold between the adhesive force F ₃ between the cured product 24 and the base 21 . Normally F ₃
is 30 to 50 Kg/cm ² , and in the case of a PTFE coating film, F ₂ is about 1.5 Kg/cm ² . Be transparent. That is, since it is necessary to transmit light such as ultraviolet rays, it must be transparent to ultraviolet rays (UV: used light of 325 nm). Must have light resistance and durability. That is, when the resin coating film 30 deteriorates or minute irregularities are formed on its surface by being exposed to the light beam 14 for a long time, the adhesive force between the cured material 24 and the resin coating film 30 increases, When the base 21 moves upward, the cured material 24 is transferred to the base 21.
There is a risk of it being torn off. Therefore, it is required to be stable against light and have excellent durability. It should be stable with respect to the photocurable resin 12. The resin coating film 30 is always made of photocurable resin 1
Since it is in contact with the photocurable resin 12, it needs to be stable with respect to the photocurable resin 12, as a matter of course. However, in the past, no resin coating film has been provided that can fully satisfy all of the above characteristics, and improvements have been desired. For example, PTFE, which has traditionally been most commonly used, has excellent light resistance and low adhesion to cured products, but it has poor transparency and low UV penetration. Also,
Another fluororesin, 4F]ethylene-purpleoloalkyl vinyl ether copolymer (hereinafter abbreviated as "PFA"), has translucency, but on the other hand,
Strong adhesion to cured products. The present invention was devised in view of the above-mentioned conventional situation, and an object of the present invention is to provide an optical modeling device on which a resin coating film having extremely excellent characteristics is formed. [Means for Solving the Problems] The optical modeling device of the present invention irradiates light from a light-transmitting window toward a photocurable resin in a container, and forms a photocurable resin on a base surface in the container or a cured product thereon. In an optical modeling device configured to form a cured product, a coating film of tetrafluoroethylene-hexafluoropropylene copolymer resin (hereinafter abbreviated as "FEP") is applied to the inner surface of the container of the transparent window. It is characterized by the formation of [Function] FEP has the following excellent properties and is particularly suitable among fluororesins as a coating film resin for transparent windows of optical modeling devices. Its transparency is comparable to or better than that of PFA, and it is transparent to ultraviolet rays. Adhesion to cured products is low. Excellent light resistance and durability. Stable against photocurable resins. The excellent properties of FEP can be explained from its molecular structure and bond dissociation energy as follows. The structural formulas of PTFE, PFA, and FEP are as follows. By the way, the dissociation energy (Kcal/mol (25°C)) of the main interatomic bonds is as follows. C-C: 84 C-F: 129 C-O: 76 On the other hand, light resistance and durability are greatly affected by the dissociation energy of the bonds that make up the molecule, and the higher the dissociation energy, the more light resistance and durability Excellent in Also, the adhesive force is smaller as the dissociation energy is larger. For this reason, FEP, which is composed of C-F bonds and C-C bonds with large dissociation energy,
It is thought that it has the same light resistance, durability, and low adhesion as PTFE, which is composed of C-F and C-C bonds. On the other hand, PFA containing a C--O bond with low dissociation energy has poor light resistance and durability, and also has high adhesive strength. [Examples] Examples of the present invention will be described below. The optical modeling apparatus of the present invention is similar to the optical modeling apparatus shown in FIG. 1 described above, except that a FEP coating film is formed as the resin coating film 30. In the present invention, if the thickness of the FEP resin coating film 30 is too thick, sufficient light transmittance cannot be obtained, and if it is too thin, light resistance and durability are insufficient, and the effect of improving adhesion by the resin coating is I can't get enough. Therefore, the thickness of the FEP resin coating film is preferably about 5 to 100 μm. As the photocurable resin molded by the apparatus of the present invention, various resins that are cured by light irradiation can be used, such as modified polyurethane methacrylate, oligoester acrylate, urethane acrylate, epoxy acrylate, Examples include photosensitive polyimide and amino alkyd. Further, as the light, various types of light such as visible light and ultraviolet light can be used depending on the photocurable resin used. Although the light may be ordinary light, using laser light has the advantages of increasing the energy level, shortening the modeling time, and improving the modeling accuracy by utilizing good light focusing. can. Hereinafter, the effects of the present invention will be explained in more detail with reference to experimental examples. Experimental example 1 The mechanical properties of each coating film of PTFE, PFA, and FEP (all 30 μm thick),
The optical properties and various physical properties were investigated and the results are shown in Table 1.

[Table] From Table 1, it is clear that the FEP resin coating film according to the present invention has high mechanical strength, excellent translucency, and low adhesion, making it ideal as a coating film for transparent windows. It is. [Effects] As detailed above, in the optical modeling device of the present invention, the resin coating film of the transparent window has excellent light transmittance, light resistance, and durability, and has extremely low adhesion to the cured product. Therefore, light can pass through with a high transmittance and efficient modeling can be performed. Moreover, deterioration of the coating film is prevented, and an optical modeling device with extremely excellent durability is provided. Moreover, since the peelability between the cured product and the coating film is improved, optical modeling can be performed smoothly.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an optical modeling apparatus according to an embodiment of the present invention. 12...Photosetting resin, 13...Transparent window, 16
...Optical fiber, 20...Light source, 21...Base, 22...Elevator, 30...Resin coating film.

Claims (1)

[Scope of Claim for Utility Model Registration] An apparatus used in an optical modeling method that includes a step of irradiating a photocurable resin with light, curing the portion irradiated with the light, and stacking the cured material, the bottom or side surface a container for storing a photocurable resin having a light-transmitting window; a light irradiation device that irradiates light into the container through the light-transmitting window; and a light irradiation device capable of moving in a direction away from the light-transmitting window within the container. a base installed in the container, and a coating film of tetrafluoroethylene-hexafluoropropylene copolymer resin is formed on the inner surface of the container of the light-transmitting window. Modeling equipment.