A three-dimensional structure formed by adhering a fluororesin molded object to a fluororesin, and a method for adhering a fluororesin molded object to a fluororesin.

Abstract

The present invention aims to provide a three-dimensional structure in which sharp-angled, fine, and complex-shaped fluororesin molded objects are laminated with high adhesion on a fluororesin coating layer applied to a substrate, and a method for forming such a three-dimensional structure. [Solution] A three-dimensional structure in which a fluororesin molded object is closely attached to a fluororesin coating layer applied to a substrate, wherein the fluororesin coating layer comprises PFA and / or FEP, and the fluororesin molded object comprises PFA, FEP and / or PTFE, wherein the fluororesin molded object is characterized by having a smooth surface and high-resolution corners.

Description

Technical Field

[0004]

[0001] The present invention relates to a three-dimensional structure made of a fluororesin in which a fluororesin molded product is formed in close contact on a fluororesin, and a method for forming a fluororesin molded product in close contact on a fluororesin. More specifically, it relates to a fluororesin structure in an integrated form in which a fluororesin molded product is formed in close contact on the surface of a fluororesin film formed by baking on a metal base material or the like, and a method for forming a three-dimensional structure made of a fluororesin in which a fluororesin molded product is formed in close contact on a fluororesin.

[0002] As used herein, the "fluororesin molded product" refers to a molded product made of a fluororesin formed by laminating while closely adhering the fluororesin on the surface of a film layer of a fluororesin coated on a base material. As used herein, the "three-dimensional structure" refers to the entire structure in which the base material, the fluororesin film on the base material, and the fluororesin molded product formed on the fluororesin film are each in close contact and integrated.

Background Art

[0003] Conventionally, in order to perform a complex shaping on a coated fluororesin film, a method of removing unnecessary portions using a cutting machine such as a machining center is generally used. However, it is difficult to coat a thick fluororesin, and it is difficult to form a layer with a film thickness exceeding 1 mm, and the thickness and height when shaping a complex shape have been limited. Therefore, a technique of separately producing a fluororesin molded product by molding, machining, or powder bed fusion bonding method, etc., and integrating it with the fluororesin film by welding or adhesion has been used. Patent Document 1 discloses a method for producing a molded product by the powder bed fusion bonding method. Also, Patent Document 2 discloses a fluororesin powder for molding that can be used in the powder bed fusion bonding method.

[0004] However, since fluororesins are inherently non-adhesive, bonding them presents difficulties. Furthermore, welding presents problems with the reliability of adhesion and limitations on welding methods. Mechanical bonding with bolts is also common, but this presents problems such as poor sealing, corrosion of the bolt material, and leaching of metal ions. In addition, when coating with a fluororesin film, high temperatures are required for welding, which results in rounded corners on convex and concave areas, making it difficult to create sharp angles and thus difficult to form fine or complex shapes. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-007221 [Patent Document 2] Japanese Patent Publication No. 2019-126931 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention aims to provide a three-dimensional structure in which sharp-angled, fine, and complex-shaped fluororesin molded objects are laminated with high adhesion on a fluororesin coating, and a method for forming such a three-dimensional structure. [Means for solving the problem]

[0007] The invention according to claim 1 relates to a three-dimensional structure in which a fluororesin molded object is closely formed on a fluororesin coating layer applied to a substrate, wherein the fluororesin coating layer comprises PFA and / or FEP, and the fluororesin molded object comprises PFA, FEP and / or PTFE, wherein the fluororesin molded object is characterized by having a smooth surface and high-resolution corners.

[0008] The invention according to claim 2 relates to the three-dimensional structure described in claim 1, wherein the three-dimensional structure, in which the fluororesin molded object is closely attached to the fluororesin coating layer applied on a substrate, is used for creating complex-shaped parts for precision component manufacturing equipment, complex-shaped parts related to aerospace and space, and complex-shaped parts related to chemical and medical plants, as well as for forming fitting tolerances and sealing structures for shaft seals.

[0009] The invention according to claim 3 is a method for forming a fluororesin molded object in close contact with a fluororesin coating layer applied to a substrate, comprising: (a) a preheating step of preheating the portion of the fluororesin coating layer that will be the bonding surface with the bottom surface of the fluororesin structure to 150°C to 300°C; (b) a first deposition step of depositing fluororesin powder on the fluororesin coating layer; (c) a step of heating the portion of the fluororesin powder deposited in the first deposition step that will become the fluororesin structure with a laser, welding it to the fluororesin coating layer and forming a bottom surface on which the fluororesin structure will be laminated; and (d) the portion deposited in the first deposition step The present invention relates to a method comprising: (a) a second deposition step of depositing additional fluororesin powder on the aforementioned fluororesin powder; (e) a step of heating portions of the fluororesin powder deposited in the second deposition step that will become further fluororesin structures with a laser and welding them to the bottom surface on which the fluororesin structures will be stacked; and (f) a step of repeatedly depositing fluororesin powder on the aforementioned fluororesin powder deposited in the second deposition step, heating portions that will become fluororesin structures with a laser, and welding them to the bottom surface on which the fluororesin structures will be stacked until a desired shape is achieved, thereby stacking fluororesin structures in stages.

[0010] The invention according to claim 4 relates to the method according to claim 3, wherein the surface roughness (Ra) of the fluororesin coating layer is 0.8 to 100.

[0011] The invention according to claim 5 relates to the method according to claim 3, wherein the fluororesin powder deposited in the first deposition step and the second deposition step is PFA and / or FEP.

[0012] The invention according to claim 6 relates to the method according to claim 3, wherein the deposition step is a step of depositing the fluororesin powder by electrostatic powder coating or spray coating. [Effects of the Invention]

[0013] According to the invention of claim 1, a three-dimensional structure is formed by adhering a fluororesin molded object to a fluororesin coating layer applied to a substrate, wherein the fluororesin coating layer comprises PFA and / or FEP, and the fluororesin molded object comprises PFA, FEP and / or PTFE, and the fluororesin molded object is characterized by having a smooth surface and high-resolution corners, thereby providing a fluororesin three-dimensional structure with sharp angles, fine details, and complex shapes.

[0014] In this specification, "high-resolution corners" refers to fine or complex shapes that are precisely formed down to the smallest detail without rounding the corners of a fluororesin molded object.

[0015] According to the invention of claim 2, the three-dimensional structure formed by closely adhering the fluororesin molded object to the fluororesin coating layer applied on a substrate is a three-dimensional structure with sharp angles, fine details, and complex shapes. Therefore, it is possible to provide a fluororesin three-dimensional structure that can be used for creating complex-shaped parts for precision component manufacturing equipment, complex-shaped parts related to aerospace and space, and complex-shaped parts related to chemical and medical plants, as well as for forming fitting tolerances and sealing structures for shaft seals.

[0016] According to the invention of claim 3, a method for forming a fluororesin molded object in close contact with a fluororesin coating layer applied to a substrate, comprising: (a) a preheating step of preheating the portion of the fluororesin coating layer that will be the bonding surface with the bottom surface of the fluororesin structure to 150°C to 300°C; (b) a first deposition step of depositing fluororesin powder on the fluororesin coating layer; (c) a step of heating the portion of the fluororesin powder deposited in the first deposition step that will become the fluororesin structure with a laser, welding it to the fluororesin coating layer and forming a bottom surface on which the fluororesin structure will be laminated; and (d) further depositing additional fluororesin on the fluororesin powder deposited in the first deposition step The method includes (a) a second deposition step of depositing powder, (e) a step of heating the portion of the fluororesin powder deposited in the second deposition step that will become a further fluororesin structure with a laser and welding it to the bottom surface on which the fluororesin structure will be laminated, and (f) a step of further depositing fluororesin powder on the fluororesin powder deposited in the second deposition step, heating the portion that will become a fluororesin structure with a laser and welding it to the bottom surface on which the fluororesin structure will be laminated, and repeating this until a desired shape is achieved, thereby laminating the fluororesin structure in stages. This method makes it possible to achieve a high degree of adhesion between the fluororesin coating layer provided on the substrate and the fluororesin structure.

[0017] According to the invention of claim 4, the surface roughness (Ra) of the fluororesin coating layer is 0.8 to 100, which makes it possible to achieve a high degree of adhesion between the fluororesin coating layer provided on the substrate and the fluororesin structure.

[0018] According to the invention of claim 5, the fluororesin powder deposited in the first deposition step and the second deposition step is PFA and / or FEP, thereby enabling a high degree of adhesion between the fluororesin coating layer provided on the substrate and the fluororesin structure.

[0019] According to the invention according to claim 6, the deposition step is a step of depositing the fluororesin powder by electrostatic powder coating or spray coating, so that an acute-angled, fine, and complex-shaped fluororesin shaped object can be constructed on the fluororesin film layer provided on the substrate.

Brief Description of the Drawings

[0020] [Figure 1A] It is a diagram schematically showing the process of a method for laminating a fluororesin on a fluororesin film according to the present invention. [Figure 1B] It is a diagram schematically showing the process of a method for laminating a fluororesin on a fluororesin film according to the present invention. [Figure 1C] It is a diagram schematically showing the process of a method for laminating a fluororesin on a fluororesin film according to the present invention. [Figure 1D] It is a diagram schematically showing the process of a method for laminating a fluororesin on a fluororesin film according to the present invention. [Figure 1E] It is a diagram schematically showing the process of a method for laminating a fluororesin on a fluororesin film according to the present invention. [Figure 1F] It is a diagram schematically showing the process of a method for laminating a fluororesin on a fluororesin film according to the present invention. [Figure 2] It is a diagram schematically showing a three-dimensional structure in which a fluororesin shaped object is adhered to a substrate coated with a fluororesin film according to the present invention, wherein the plane of the fluororesin shaped object is smooth and the corners are highly detailed.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, a method for laminating a fluororesin structure (5) on a fluororesin film according to the present invention and a three-dimensional structure formed by the laminating method will be described. However, the present invention is not limited to the embodiments shown below. A manufacturing method of a three-dimensional structure formed on a fluororesin film according to the present invention is described below, but this three-dimensional structure is not necessarily manufactured only by the following manufacturing method.

[0022] In the lamination method according to the present invention, as shown in Figure 1A, first, fluororesin powder (2) is deposited on a substrate having a preheated fluororesin coating (1).

[0023] According to the present invention, the resin used for the fluororesin coating (1) on a substrate (not shown) can be PTFE resin (melting point 327°C), PFA resin (melting point 310°C), FEP resin (melting point 260-270°C), ETFE resin (melting point 270°C), EcTFE resin (melting point 245°C), PcTFE resin (melting point 210-215°C), and the like. PTFE resin is a polymer of tetrafluoroethylene, and it exhibits excellent heat resistance and chemical resistance. It also has the characteristic of having a very low coefficient of friction. PFA resin is a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene. This resin has properties comparable to PTFE resin, but with a lower viscosity when melted, resulting in high processability. It is also used as a molding material in the semiconductor field. FEP resin refers to a copolymer of tetrafluoroethylene and hexafluoropropylene. This resin has a low viscosity when melted, and therefore has the characteristic of being able to form a continuous film without pinholes when forming a fluororesin coating (1). ETFE resin refers to a copolymer of tetrafluoroethylene and ethylene, and this resin is characterized by its excellent chemical resistance, insulation properties, low abrasion, and low cost. EcTFE resin refers to a copolymer of ethylene and chlorotrifluoroethylene, and this resin possesses excellent electrical properties and chemical resistance. PcTFE resin refers to a polymer of chlorotrifluoroethylene, and this resin also has excellent optical properties. These fluororesins may be used individually or in combination.

[0024] In the present invention, the surface roughness (arithmetic mean roughness) of the fluororesin film (1) on the substrate is preferably Ra = 0.8 to 100, from the viewpoint of improving the degree of adhesion with the laminated fluororesin structure (5). This is because if Ra is greater than 100 or less than 0.8, adhesion will be poor. The arithmetic mean roughness Ra is a value that represents the average distance from a reference line, where the average value of the surface's irregularities is used as the reference line, within a given interval.

[0025] From the viewpoint of improving adhesion with the laminated fluororesin structure (5), the geometric tolerance (flatness) of the surface of the fluororesin layer according to the present invention is preferably 0.2 mm or less. Flatness refers to the degree of deviation of a planar shape from a geometrically correct plane; simply put, it indicates the distance between two planes separated above and below the surface of an object.

[0026] In the lamination method according to the present invention, the temperature at which the fluororesin film (1) is preheated is preferably close to the melting point of the fluororesin used in the fluororesin film (1), specifically, 150°C to 300°C. The reason for this is that if the preheating is above the melting point, the fluororesin coating (1) may deteriorate due to heat, and if it is below the melting point, it may not be possible to properly weld the fluororesin powder (2) deposited on the fluororesin coating (1). Preheating does not need to be performed on the entire fluororesin coating (1); it only needs to be done on the portion that will be in contact with the bottom surface of the fluororesin structure (5).

[0027] The fluororesin powder (2) deposited on the fluororesin film (1) according to the present invention is not limited, and for example, PTFE resin, PFA resin, FEP resin, ETFE resin, EcTFE resin, PcTFE resin, etc. can be used. The fluororesin powder (2) may be made of the same material as the fluororesin film (1) provided on the substrate, or it may have a different composition, but it is preferable to use a resin with excellent affinity.

[0028] The present invention provides a method for depositing fluororesin powder (2), which includes methods such as depositing the fluororesin powder (2) on a flat surface, using electrostatic powder coating, using spray coating, and converting the fluororesin powder (2) into an aqueous paint and applying it to the fluororesin layer.

[0029] Electrostatic powder coating is a method of coating where the object to be coated and the powder coating are charged, causing the powder coating to be electrically attracted to the surface of the object. This method has the advantage of making it easy to control the thickness of the coating.

[0030] In the lamination method of the present invention, as shown in Figure 1B, the portion of the deposited fluororesin powder (2) that will become the bottom surface (4) on which the fluororesin structure is laminated is heated and welded by a laser (3), thereby forming the bottom surface (4) on which the fluororesin structure is laminated (Figure 1C). The thickness of the layer formed as the bottom surface (4) on which the fluororesin structure is laminated is adjusted to approximately 0.03 to 0.2 mm. The reason is that if the film thickness is too thick, the adhesion will decrease due to poor melting, and if it is too thin, there is a risk of thermal degradation.

[0031] The laser (3) used in the stacking method of the present invention can be, for example, a solid-state laser, a liquid laser, a gas laser, or a semiconductor laser. Solid-state lasers use solid materials such as YAG (yttrium aluminum garnet) ore as the laser medium. They have the advantage of being able to increase laser output while keeping the volume small, meaning that high laser output can be obtained even with a small resonator. Liquid lasers are lasers that use a liquid as the laser medium. Generally, dye lasers, which use organic dyes dissolved in an organic solvent as the medium, are used. Dye lasers have the characteristic that their wavelength can be changed by changing the dye molecules dissolved in the organic solvent. Gas lasers are lasers that use gas as the laser medium. Compared to other lasers, they have the advantage of a homogeneous laser medium, low losses, and a larger resonator structure, allowing for higher laser output. Semiconductor lasers are lasers made from semiconductor materials and have the characteristic of being able to produce high laser output with a small device. When PFA is used as the fluororesin coating (1), the wavelength of a gas laser (CO2 laser) using carbon dioxide as the laser medium is preferable because it is suitable for the absorption characteristics of PFA. However, by improving the filler in the fluororesin powder (2), it is possible to broaden the range of applicable lasers (3).

[0032] In the lamination method of the present invention, the laser output used is preferably around 60W when PFA is used as the fluororesin layer. Even when using fluororesins other than PFA, those skilled in the art can appropriately change the laser output to find the optimal output.

[0033] An example of a laser generator used in the present invention is a 3D printer (model number: RaFaElII300C-HT, manufactured by Aspect Co., Ltd.). The specifications of the 3D printer are as shown in Table 1 below.

[0034] [Table 1]

[0035] The fluororesin molded object (7) formed using the above 3D printer showed high adhesion in the peel strength test.

[0036] In the lamination method of the present invention, after forming a bottom surface (4) on which the fluororesin structure is to be laminated, a new fluororesin powder is deposited on the surface including the bottom surface (4) on which the fluororesin structure is to be laminated, as shown in Figure 1D. Then, the process of welding only the necessary parts with a laser (3) (Figures 1E and 1F) is repeated to form the desired three-dimensional structure. For example, powder bed fusion bonding can be used in this process.

[0037] Figure 2 shows a schematic diagram of a three-dimensional structure in which a fluororesin molded object (7) is in close contact with a substrate (6) coated with a fluororesin film, formed by the lamination method according to the present invention. Because the three-dimensional structure has a smooth plane and highly defined corners, it can also be a three-dimensional structure with a fine and complex shape. [Industrial applicability]

[0038] The present invention relates to a three-dimensional structure formed by closely adhering a fluororesin molded object onto a fluororesin, and a method for forming a three-dimensional structure of fluororesin by closely adhering a fluororesin molded object onto a fluororesin. This invention is suitably used, for example, for creating complex-shaped parts for precision component manufacturing equipment, complex-shaped parts related to aerospace and space, and complex-shaped parts related to chemical and medical plants, as well as for forming fit tolerances and seal structures for shaft seals. [Explanation of symbols]

[0039] 1: Fluororesin coating 2: Fluororesin powder 3: Laser 4: Bottom surface for laminating fluororesin structures 5: Fluororesin structure 6: Base material 7: Fluoropolymer molded objects

Claims

1. A three-dimensional structure in which a fluororesin molded object is closely attached to a fluororesin coating layer applied to a substrate, The fluororesin coating layer comprises PFA and / or FEP. The aforementioned fluororesin molded product includes PFA, FEP and / or PTFE, Herein, the fluororesin molded object is a three-dimensional structure characterized by having a smooth surface and highly detailed corners.

2. The three-dimensional structure, in which a fluororesin molded object is closely attached to the fluororesin coating layer applied on a substrate, is used for creating complex-shaped parts for precision component manufacturing equipment, complex-shaped parts related to aerospace and space, and complex-shaped parts related to chemical and medical plants, as well as for forming fitting tolerances and sealing structures for shaft seals, according to claim 1.

3. A method for forming a fluororesin molded object in close contact with a fluororesin coating layer applied to a substrate, (a) A preheating step in which the portion of the fluororesin coating layer that will be joined to the bottom surface of the fluororesin structure is preheated to 150°C to 300°C, (b) A first deposition step of depositing fluororesin powder onto the fluororesin film layer, (c) A step of heating the portion of the fluororesin powder deposited by the first deposition step with a laser to form the fluororesin structure, welding it to the fluororesin coating layer, and forming a bottom surface on which the fluororesin structure is laminated, (d) A second deposition step in which additional fluororesin powder is deposited on the fluororesin powder deposited in the first deposition step, (e) A step of heating the portion of the fluororesin powder deposited by the second deposition step that will become a further fluororesin structure with a laser and welding it to the bottom surface on which the fluororesin structure is laminated, (f) A method comprising the step of further depositing fluororesin powder on the fluororesin powder deposited in the second deposit step, heating the portion that will become a fluororesin structure with a laser, and welding the portion to the bottom surface on which the fluororesin structure will be stacked, and repeating this until a desired shape is achieved, thereby stacking the fluororesin structure in stages.

4. The method according to claim 3, wherein the surface roughness (Ra) of the fluororesin coating layer is 0.8 to 100.

5. The method according to claim 3, wherein the fluororesin powder deposited in the first deposition step and the second deposition step is PFA and / or FEP.

6. The method according to claim 3, wherein the deposition step is a step of depositing the fluororesin powder by electrostatic powder coating or spray coating.

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