JP2006007546A - Molding transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a molded product having a fine stripe shaped pattern applied to its almost arbitrary curved surface having a large area by molding transfer in a molding transfer method. <P>SOLUTION: The molding transfer method for manufacturing the molded product including at least a curved surface and having a predetermined fine stripe shaped pattern applied to its curved surface by molding transfer includes a surface dividing process S1 for dividing the curved surface into surface elements, a curved surface master molding process S2 for molding a curved surface master having the same shape as a molded product having no pattern but having the curved surface, a divided pattern transfer process S3 for transferring the patterns to the regions corresponding to the respective surface elements of the curved surface master using a split mold having the pattern shapes in the regions corresponding to the surface elements, a mold forming process S4 for forming a mold using an electrocasting method on the basis of the curved surface master to which the patterns are transferred, a pattern transfer molding process S5 for performing the transfer molding of the molded product having the curved surface and the pattern thereon using the mold and a release process S6 for releasing the molded product from the mold, as fundamental processes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding transfer method for manufacturing a molded product having a fine pattern transferred to a surface.

In recent years, light guide plates, diffuser plates, antifouling / water repellent structures mainly composed of small and medium molded products such as optical components and lighting components, and antifouling / water repellent structures composed mainly of resin molded products such as housing parts In order to impart a new optical function and environmental resistance to the body and the like, a technique for forming a fine shape with irregularities on the surface of the molded product has been studied and developed. As such a technique, for example, a nanoimprint method is known in which pattern transfer is performed by press molding using a mold having a nano-order fine shape (see, for example, Patent Document 1). Similarly, a method of manufacturing a lenticular lens sheet in which fine irregularities are integrally formed on the surface by using pattern transfer is known (see, for example, Patent Document 2).
US Pat. No. 5,772,905 JP-A-9-311204

  However, the technology for forming a fine shape as described in Patent Document 1 described above is limited to application to an object having a small area and a flat plate, and targets other than the flat plate as shown in Patent Document 2 Even in the technology for forming a fine shape on an object, it is not possible to form a fine shape on the surface of an object having a substantially arbitrary general curved surface.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a molding transfer method for manufacturing a molded product in which a fine shape pattern is molded and transferred on an almost arbitrary curved surface with a large area.

  In order to achieve the above object, the invention of claim 1 is a molding transfer method for manufacturing a molded product having at least a curved surface, and molding and transferring a predetermined fine shape pattern on the curved surface. A surface dividing step for dividing, a curved surface master forming step for forming a curved surface master having the same shape as the molded product without providing the pattern, and the pattern shape at a portion corresponding to each surface element. A divided pattern transfer step of transferring the pattern to a portion corresponding to each surface element of the curved surface master using the divided mold provided, and using an electroforming method based on the curved surface master to which the pattern is transferred Using a mold creating step for creating a mold and the mold created in the above step, the curved surface and a molded product having the pattern on the curved surface are transferred and molded. A pattern transfer molding process that is intended to include, a releasing step of releasing the molded article is transferred molded by the process.

  According to a second aspect of the present invention, in the molding transfer method according to the first aspect, the surface dividing step divides the molded product into the surface elements using a three-dimensional shape model of the molded product, and the separation in the releasing step. The method includes a step of determining the division so that the shape of the pattern with respect to the mold releasing direction of the mold does not have an undercut relationship.

  A third aspect of the present invention is the molding transfer method according to the first or second aspect, wherein the surface dividing step is performed such that a pattern included in each surface element is included in a surface element adjacent to the surface element. A step of determining the position and direction of each pattern so as to be continuous is included.

  According to a fourth aspect of the present invention, in the molding transfer method according to any one of the first to third aspects, each of the curved surface master molding step and the pattern transfer molding step is performed using at least two molds. One of the molds used in is shared by both processes.

  A fifth aspect of the present invention is the molding transfer method according to any one of the first to third aspects, wherein the curved surface master molding step includes a step of cutting a resin into the shape of the curved surface master.

  A sixth aspect of the present invention is the molding transfer method according to any one of the first to fifth aspects, wherein the divided pattern transfer step uses a thermoplastic resin as a material for forming the curved surface master and the divided mold. A transparent body is used as a material to be formed, and the curved surface master is partially heated by passing through a split mold made of the transparent body and irradiating the curved surface master made of the thermoplastic resin with energy rays. The method includes a step of transferring the pattern by the split mold.

  The invention according to claim 7 is the molding transfer method according to any one of claims 1 to 5, wherein the divided pattern transfer step uses a transparent thermoplastic resin as a material for forming the curved surface master, and the transparent A step of partially heating the surface of the curved surface master by passing through a curved surface master and irradiating energy rays, and transferring the pattern to the heated portion by the split mold.

  The invention according to claim 8 is the molding transfer method according to any one of claims 1 to 5, wherein the division pattern transfer step creates the curved surface master by stereolithography and UV-cures the surface layer of the curved surface master. Coating a functional resin, pressurizing the split mold onto the coating layer of the curved surface master, and curing the coating layer with UV light.

  A ninth aspect of the present invention is the molding transfer method according to any one of the first to seventh aspects, wherein the divided pattern transfer step is performed together with the molding die in the pattern transfer molding step during pattern transfer by the divided mold. This includes a step of using the core-side mold to be used as a lower mold that receives the pressure applied by the split mold.

  A tenth aspect of the present invention is the molding transfer method according to any one of the first to ninth aspects, wherein the divided pattern transfer step is performed when the divided mold is released after pattern transfer by the divided mold. This includes a step of releasing the mold while ultrasonically vibrating.

  The invention of claim 11 is the molding transfer method according to any one of claims 1 to 10, wherein in the mold releasing step, the mold is ultrasonically vibrated when the mold is released from the molded product. It includes a step of releasing the mold.

  The invention according to claim 12 is the molding transfer method according to any one of claims 1 to 11, wherein the pattern transfer molding step uses a material in which the pattern portion of the molded product is different from other portions of the molded product. The process of using and forming is included.

  According to the present invention, a curved surface is divided into minute surface elements, and a pattern is transferred to each surface element portion of a curved surface master having a curved surface without a pattern and formed into the same shape as a molded product using a divided mold. Therefore, it is possible to easily and reliably form a curved surface master having a fine shape pattern of a molded product at an arbitrary position on the curved surface. Furthermore, it is possible to easily create a mold having a curved surface and a pattern of a molded product by using an electroforming method based on the curved surface master with the pattern. A molded product to which the pattern is transferred can be easily produced. According to such a molding transfer method, a molded product in which a fine shape pattern is molded and transferred onto a large area and a substantially arbitrary curved surface can be easily and efficiently manufactured. Since the fine shape pattern can be transferred to an arbitrary position on the curved surface, a new function can be developed, or a function can be added or improved in a structure or resin molded product having a large area size having a fine shape on the surface and a free curved surface.

  Hereinafter, a molding transfer method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a process flow of a molding transfer method. The molding transfer method of the present invention is a molding transfer method for manufacturing a molded product including at least a curved surface and having a predetermined fine shape pattern (hereinafter referred to as a pattern) molded and transferred on the curved surface. The molded article may include a flat surface as long as it includes at least a curved surface. This molding transfer method includes a surface dividing step (S1) for dividing a curved surface into minute surface elements, and a curved surface master forming step (S2) for forming a curved surface master having the same shape as the molded product without providing a pattern. ) And a divided pattern transfer step (S3) for transferring the pattern to a portion corresponding to each surface element of the curved surface master using a divided mold having a pattern shape at a portion corresponding to each surface element, and the pattern is transferred A mold creation step (S4) for creating a mold using an electroforming method based on the curved surface master, and a molded product having a curved surface and a pattern on the curved surface using the created mold A pattern transfer molding step (S5) for transfer molding and a mold release step (S6) for releasing the transfer molded product from the mold are included as basic steps. Hereinafter, the molding transfer method will be described along these steps.

  The molding transfer method will be described along the above-described steps with reference to FIGS. 2 to 4 are the surface dividing step (S1), FIGS. 5 and 6 are the curved surface master forming step (S2), FIGS. 7 to 10 are the divided pattern transfer step (S3), and FIGS. FIG. 14 shows a mold forming step (S4), FIG. 14 shows a pattern transfer molding step (S5) and a mold releasing step (S6), and FIG. 15 shows a manufactured molded product.

(Surface division process S1)
As an example of a molded product formed by the present molding transfer method, a molded product having a dome-shaped curved surface is taken up as a three-dimensional shape model 11 of the molded product shown in FIG. As shown in FIG. 2B, a fine pattern 10 whose cross section is continuous in a triangular shape is regularly formed on the curved surface S adjacent to each other on the upper outer surface formed of the curved surface. For example, when a light source is provided inside the dome of the three-dimensional shape model 11, this structure is used for optically processing the light from the light source to make the light intensity distribution uniform or to have a specific distribution.

  The above-described curved surface S is defined as the surface of a molded product from which the portion of the pattern 10 protruding from the surface is removed, for example. As another definition method of the curved surface S, a curved surface obtained by averaging the unevenness due to the pattern 10 may be used. 3 (a) and 3 (b) show a curved surface body 12 having the same shape as a molded product having a curved surface S (in a global sense) without having a pattern 10. FIG.

  In the molding and transfer method of the present invention, when the curved surface S constituting the curved surface body 12 is a general curved surface (so-called free curved surface) having no symmetry such as rotational symmetry or translational symmetry, for example, a curved surface For example, the optically meaningful regular pattern 10 is reliably and relatively inexpensively formed over the entire area of S. In this method, as shown in FIGS. 4 (a) and 4 (b), the concept of the surface element 13a is introduced, and in the surface dividing step S1, the curved surface S is divided using, for example, a surface element 13a composed of a triangular plane. . Although the size of the surface element 13a depends on the size of the pattern 10, in the case of an optical application, for example, the surface element 13a is composed of minute elements of 20 mm square or less. The following description will be made on the premise of a molded article for optical use having a pattern that exhibits an optical function.

  The curved surface shape body 12 is reconfigured as a set of the above surface elements 13 a, and the result is defined as the curved surface reconstruction body 13. The pattern 10 is divided in association with each surface element 13a, and is divided into patterns on each surface element 13a. The surface division step S1 is performed using, for example, a three-dimensional shape model 11 of a molded product on CAD.

(Curved surface master forming step S2)
The above-described curved surface reconstruction body 13 generated by dividing and reconstructing the curved surface shape body 12 by the surface element 13a on the CAD is actual as the curved surface master 14 in the curved surface master forming step S2, as shown in FIGS. Is given. That is, based on the CAD data of the curved surface reconstructed body 13, as shown in FIG. 5, a curved surface master mold 2 composed of an upper mold 22 and a lower mold 21 is formed. The curved surface master 14 shown in 6 (a) and 6 (b) is resin-molded. A general-purpose thermoplastic resin such as PMMA (methacrylic resin), PC (polycarbonate), PS (polystyrene), PP (polypropylene) or the like is used as the molding resin. For optical applications, in particular, a transparent resin is used.

(Division pattern transfer step S3)
The curved surface master 14 is provided with a pattern in this divided pattern transfer step S3. The application of the pattern is performed by transfer for each of the surface elements 13a described above using the split mold 3 shown in FIGS. As described above, the split mold 3 includes the reversal pattern 10a obtained by reversing the pattern 10 divided as a pattern associated with each surface element 13a. A plurality of split molds 3 are manufactured based on the combination of the shape of each surface element 13a and the arrangement of the inversion pattern 10a associated with the surface element 13a.

  As a processing method for obtaining the split mold 3, machining, MEMS (Micro Electro Mechanical Systems) processing, LIGA (lithography electroforming) processing, or the like is used. The size of the split mold 3 is, for example, 20 mm square or less. The pattern 10 and the inversion pattern 10a have regular concavo-convex shapes having a feature shape dimension of 1 nm to 100 μm. In addition to the continuous linear pattern shown in FIG. 7, these patterns have, for example, a concavo-convex shape such as a lattice shape, a prism shape, a dot shape, and a pyramid shape, and each has a predetermined optical pattern. In order to express the function, it is arranged regularly or conversely at random.

  As shown in FIG. 8, the transfer of the divided pattern is performed using an attitude control device, for example, an arm type robot device 4. The robot apparatus 4 includes a control device 40. The robot apparatus 4 can hold the split mold 3 to control and move the posture and position of the split mold 3, and can press the surface element 13a vertically, for example. The split mold 3 is integrated with a stronger upper mold 32 for mechanical strength and convenience of handling, and is provided at the tip of a pressurizing device 41 provided at the tip of the robot arm. Further, the upper mold 32 includes a heating device and a cooling device (not shown) used for pattern transfer.

  The lower mold 20 that holds the curved surface master 14 has a structure capable of receiving a pressure of 10 kN to 1000 kN during pattern transfer, and is 20 ° C. to 30 ° C. from the glass transition temperature of the resin constituting the curved surface master 14. It has a heating / cooling mechanism that maintains a low temperature.

  The curved surface master 14 is set on the lower mold 20 set to a temperature lower by 20 ° C. to 30 ° C. than the glass transition temperature of the resin constituting the curved surface master 14. In this state, the robot apparatus 4 determines the surface angle and the center position of the surface element 13 a based on the position data of the surface element 13 a of the curved surface master 14 via the control device 40. Subsequently, the robot device 4 controls the posture of the arm and causes the split mold 3 held at the tip of the arm to face the surface element 13a on the curved surface master 14 on which pattern transfer is to be performed, so that the normal line of the surface element 13a is obtained. It is moved along the direction L0 (FIG. 9A).

  Simultaneously with the movement of the split mold 3, the split mold 3 is heated to a temperature 20 ° C. to 30 ° C. higher than the glass transition temperature of the resin of the curved surface master 14 by the heating device of the upper mold 32. After completion of temperature rise and movement, the pressurizing device 41 presses the split mold 3 against the surface element 13a of the curved surface master 14 with a load of 10 kN to 1000 kN. The area of the surface element 13a of the curved surface master 14 is melted by the heat of the split mold 3 that has become high temperature, and the pattern is transferred by pressing. The pressing time varies depending on the viscoelastic characteristics of the resin, but for example, about 1 minute is desirable for PMMA.

  After the pattern transfer is completed, the split mold 3 is cooled to a temperature 20 ° C. to 30 ° C. lower than the glass transition temperature of the resin by the cooling device of the upper mold 32. After completion of cooling, the pressurization is stopped and the split mold 3 is released from the curved surface master 14. FIG. 9B shows the surface element 13a to which the pattern has been transferred.

  By repeating such division pattern transfer by the division mold 3 while changing the target surface element 13a and replacing the corresponding division mold 3 as necessary, patterns are applied to all the surface elements of the curved surface master 14. As shown in FIGS. 10A and 10B, the pattern transfer curved surface master 15 having the pattern 10 on the curved surface is obtained.

(Molding mold making process S4)
In this molding die creation step S4, a molding die is created using the electrocasting method based on the pattern transfer curved surface master 15. First, as shown in FIGS. 11A and 11B, on the surface of the pattern 10 of the pattern transfer curved surface master 15, a nesting 16 having a reversal pattern 16a in which the unevenness of the pattern 10 is reversed is formed as an electroforming layer. . As shown in FIGS. 12A and 12B, the insert 16 released from the pattern transfer curved surface master 15 includes a reverse pattern 16a inside the dome shape.

  Subsequently, as shown in FIG. 13, a forming die 5 including a pattern die 24 provided with the above-described insert 16 inside the cavity and a core die 23 shaped so as to substantially fill the dome-shaped portion of the pattern die 24 is produced. . The core mold 23 includes an ejecting device 25 having an ejecting bar 25a used when releasing a molded product.

(Pattern transfer molding step S5 and mold release step S6)
As shown in FIGS. 14A and 14B, the pattern transfer molding step S5 is performed by filling and molding the resin for forming the molded product 1 in the above-described molding die 5 which is closed, and FIG. As shown, a mold release step S6 is performed by the ejecting device 25 following the mold opening, and the molded product 1 is obtained. The resin that forms the molded product 1 is not limited to a thermoplastic resin, and any resin that can be molded by the molding die 5 can be appropriately selected according to the function of the product.

  As shown in FIGS. 15 (a) and 15 (b), the obtained molded product 1 is provided with the pattern 10 on each curved surface of the molded product 1 by providing the pattern 10 for each surface element 13a. . As described above, according to the present molding transfer method, the fine shape pattern 10 can be easily and efficiently transferred to an arbitrary position on the curved surface in the creation of the curved surface master, and the pattern transfer is repeated for each surface element 13a. Thus, a fine pattern can be easily and efficiently transferred over a large area. Furthermore, a mold capable of forming a desired curved surface and pattern based on the curved surface master is obtained, and the desired molded product 1 can be easily obtained.

  Next, the surface dividing step S1 will be further described with reference to FIGS. First, the determination of division in consideration of the mold release direction will be described. In forming the curved surface reconstructed body 13 shown in FIG. 16A, the angle θ formed by the mold release direction L1 and the normal direction L2 of the surface element 13a shown in FIG. 16B, and FIG. The angle α formed by the mold release direction L1 shown and the direction L3 along the formation surface of the individual pattern forming each pattern 10 is considered. More specifically, the direction L3 is the direction of the line segment obtained by vertically projecting the release direction line segment onto the individual pattern forming surface. Here, for ease of understanding, a representative point P is determined for the surface element 13a, and the position, size, and direction (the direction of the triangle in the three-dimensional space) of the surface element 13a are determined based on the representative point P. The representative point P can be, for example, a triangular geometric center of gravity. Then, as shown in FIG. 16B, at least the directions L1 and L2 are defined so as to pass through the representative point P.

  The division determination considering the mold release direction L1 is, for example, within a range where the angle α is positive (α> 0), that is, within a range where the pattern mold 24 and the pattern 10 of the molded product 1 do not interfere with each other during mold release. Is to determine the division of the surface element 13a. According to such division, the shape of the pattern 10 with respect to the mold release direction of the mold 5 does not have an undercut relationship at the time of mold release in the above-described mold release step S6. Therefore, it is possible to avoid damage to the fine pattern at the time of mold release.

  Next, the determination of division in consideration of pattern continuity will be described. In the surface division step S1, as described above, the curved surface 12 is divided into a set of surface elements 13a and the curved surface S is reconstructed, but the pattern 10 is also reconstructed along with the surface elements 13a. At this time, in order to cause the pattern 10 to exhibit a predetermined optical function, it is necessary to ensure the continuity of the pattern 10 between the surface elements 13a and to accompany the surface elements 13a.

  Therefore, when determining the division of the surface element 13a having the pattern 10 shown in FIG. 17A, as shown in FIG. 17B, the reconstruction is performed by dividing the pattern 10 in the surface element 13a and reconfiguring them. The pattern 10b is determined by optimizing the position. This reconstruction pattern 10b is generated by the rotation R around the normal direction L2 of the surface element 13a and the parallel movement in the two directions x and y in the plane formed by the surface element 13a. The direction and position are adjusted so that the configuration patterns 10b are continuous. During this adjustment, the direction of continuity L4 of the pattern 10 and the direction of the reconstruction pattern 10b shown in FIG. 17C are also optimized to coincide with each other. Since the surface is divided by determining the position and direction of the pattern so as to ensure the continuity (regularity) of the pattern, a desired continuous fine shape pattern can be applied to the surface of the molded product, and a predetermined function is provided. A molded product is obtained.

  Next, the molding die used in the curved surface master molding step S2 and the pattern transfer molding step S5 will be described (see FIGS. 5 and 13). The curved surface master molding step S2 and the pattern transfer molding step S5 are each performed using at least two molds, but one of the molds used in these processes is usually common in both processes. The equipment can be simplified and the molding can be performed with high accuracy. For example, the lower mold 21 of the curved surface master mold 2 shown in FIG. 5 and the core mold 23 of the mold 5 shown in FIG. 13 both depend on the fine shape pattern on the curved surface and curved surface. Therefore, these molds can be used as a common mold in both processes. However, when these molds are shared, it is necessary to make the heating / cooling mechanism and the like have commonality.

  The core mold 23 of the mold 5 described above can also be used as the lower mold 20 that receives the pressure applied by the divided mold 3 in the divided pattern transfer step S3 (see FIGS. 8 and 13). Only the surface side of the curved surface master 14 is to be processed in the divided pattern transfer process and is required in the subsequent processes. Therefore, there is no problem even if the core mold 23 of the molded product is provided with a structure such as a rib groove or the like as a lower mold 20. Since the lower mold 20 receives pressure from the divided mold 3 during heat transfer, the shape of the curved master 14 on which the pattern is transferred by pressurization is maintained, the deformation of the curved master 14 can be suppressed, and the final molded product The accuracy of is not impaired. In addition, when the core mold 23 is used as the lower mold 20 when removing the curved surface master 14 after the division pattern transfer is completed, the mold release device 25 attached to the core mold 23 can be used. The transfer curved surface master 15 can be easily taken out.

  Next, another example of the curved surface master forming step S2 will be described with reference to FIG. As shown in FIGS. 18A and 18B, the curved surface master 14 can be formed by cutting the resin block BL. In this case, since the resin molding is not performed, the molding die can be omitted. Further, the curved surface master 14 can be formed by finishing a resin molded product having a large outer shape not particular to details by cutting. In this case, the mold for molding can be simplified.

  Cutting is performed based on the CAD data of the curved surface reconstructed body 13 shown in FIG. The curved surface master 14 is molded from the resin block BL by cutting, and a solid shape as shown in FIG. 18B, that is, a shape that is not a hollow shape as shown in FIG. By doing so, the lower mold 20 (FIG. 8) in the divided pattern transfer step S3 can be omitted.

  Next, another example of the divided pattern transfer step S3 will be described with reference to FIGS. In the divided pattern transfer process shown in FIGS. 19A and 19B, a thermoplastic resin is used as a material for forming the curved surface master 14 and a transparent body is used as a material for forming the divided mold 3. In addition to the cooling device, the upper mold 32 includes a radiation source 61 that generates energy rays as a heating device. A structure such as a reflecting mirror 63 that guides the energy beam 62 from the radiation source 61 to the curved surface master 14 is formed inside the upper mold 32. As the energy beam 62, for example, a laser beam having a wavelength region corresponding to the absorption wavelength region of the thermoplastic resin material can be used. Quartz, calcium fluoride, silicon or the like can be used as the transparent body forming the split mold 3.

  In the divided pattern transfer, as described above, the divided mold 3 is moved along the normal direction L0 of the surface element 13a, and the energy rays 62 from the radiation source 61 are transmitted through the divided mold 3 made of a transparent material and heated. The area of the surface element 13a is heated by irradiating the curved surface master 14 made of a plastic resin. That is, after the resin temperature of the surface element 13a is 20 to 30 ° C. higher than the glass transition temperature, pressure and transfer are performed. Thereafter, the irradiation of the energy beam 62 is stopped, the area of the surface element 13a is cooled by using the cooling device attached to the upper mold 32, and the temperature of the resin is lowered to 20 to 30 ° C. below the glass transition temperature. Then, the split mold 3 is released. Thereafter, the same operation is repeated for the other surface elements 13a. According to such a method, divided pattern transfer can be performed under local heating / cooling, so that thermal efficiency is good and thermal deformation in a region other than the transfer surface can be minimized.

  In the divided pattern transfer process shown in FIG. 20, a transparent thermoplastic resin is used as a material for forming the curved surface master 14. The upper mold 32 includes a cooling device. The thermoplastic resin is heated by a heating device provided separately below the lower mold 21. The heating apparatus includes a radiation source 64 that generates energy rays, and a reflecting mirror 66 that guides the energy rays 65 from the radiation source 64 to the surface element 13a that is a heating region. The lower mold 21 is made of a material such as quartz, silicon, or calcium fluoride that transmits the energy beam 65. As the transparent resin constituting the curved surface master 14, PMMA, PC, or the like is used. As the energy beam 65, a laser beam in a wavelength region that transmits the resin of the curved surface master 14 can be used.

  In the divided pattern transfer step, first, as described above, the divided mold 3 is moved along the normal direction L0 of the surface element 13a to be brought close to or in contact with the surface element 13a. Next, the angle of the reflecting mirror 66 is adjusted based on the CAD data of the curved surface reconstruction body 13, and the energy beam 65 from the radiation source 64 is reflected by the reflecting mirror 66 and guided to the area of the surface element 13a. The energy rays 65 transmitted through the transparent lower mold 21 and the transparent curved surface master 14 heat the surface layer of the surface element 13a region of the curved surface master 14. The area of the surface element 13a is heated by focusing the energy line 65 in this area and scanning the focal position, or by dividing the divided mold 3 that is in proximity to or in contact with the surface element 13a by the energy line 65. This can be done by utilizing heat conduction from the mold 3 to the surface layer.

  After the resin temperature in the area of the surface element 13a reaches 20 to 30 ° C. higher than the glass transition temperature, pressure and transfer are performed. After that, the irradiation of the energy beam 65 is stopped, the area of the surface element 13a is cooled by using the cooling device attached to the upper mold 32, and the temperature of the resin is lowered to 20 to 30 ° C. below the glass transition temperature. Then, the split mold 3 is released. Thereafter, the same operation is repeated for the other surface elements 13a. According to such a method, according to such a method, the surface element 13a region of the curved surface master 14 is partially (locally) heated from the curved surface master 14 side by the energy rays 65 that pass through the transparent body, and the divided pattern is formed. Since transfer is possible, cooling is easy and thermal efficiency is good, and thermal deformation that should be avoided from occurring on the surface elements other than the surface element portion to be subjected to pattern transfer can be suppressed.

  In the divided pattern transfer process shown in FIG. 21, the curved surface master 14 is created by stereolithography, the surface layer of the curved surface master 14 is coated with a UV curable resin, and pattern transfer is performed on the coating layer 14a. In this transfer process, a UV light (ultraviolet light) generation source 67, a light guide 68 for guiding the UV light from the UV light generation source, and a condensing lens for irradiating the UV light provided at the tip of the light guide 68 are provided. An irradiation head 69 is used. The irradiation head 69 is fixed to the upper mold 32 and moves with the movement of the upper mold 32 and the divided mold 3 integrated with the upper mold 32 to irradiate the transfer area with the UV light 70. Unlike any of the above-described upper molds 32, the upper mold 32 does not include a heating device and a cooling device.

  The curved surface master 14 is formed using CAD data and an optical modeling method. According to stereolithography, since a curved surface master can be created based on CAD data, it is possible to reduce the labor and cost of creating a mold. The coating layer 14 a is formed by spray coating a surface layer of the curved surface master 14 with a UV curable resin. The film thickness of the coating layer 14a is about 2 to 50 times the transfer depth.

  In the divided pattern transfer step, first, as described above, the divided mold 3 is moved along the normal direction L0 of the surface element 13a to be brought into contact with the surface element 13a and pressurized. The applied pressure may be about 0.5 kN to 5 kN. The surface element 13 a is irradiated with UV light 70 from a UV light generation source 67 through an irradiation head 69. After the UV curable resin is cured by the irradiation of the UV light 70 and the pattern transfer is completed, the irradiation of the UV light 70 is stopped and the split mold 3 is released. Thereafter, the same operation is repeated for the other surface elements 13a. According to such a method, the coating layer 14a made of a UV curable resin is the target of divided pattern transfer, so that a large pressing force is not required, and heating or cooling is not required for the transfer. An apparatus for transfer can be simplified.

  In the divided pattern transfer process shown in FIG. 22, when the divided mold 3 is released after the pattern transfer by the divided mold 3, the divided mold 3 is released while being ultrasonically vibrated. An ultrasonic generator US is provided in the upper mold 32 (which may be between the split mold 3 and the pressure device 41 (FIG. 8)). The direction of ultrasonic vibration by the ultrasonic generator US can be arbitrarily set in the mold release direction L6 and the in-plane direction of the surface element 13a, and the amplitude is equal to or smaller than the size of the pattern to be transferred. After the pressure transfer in any of the pattern transfer processes described above and before the start of mold release, the split mold 3 is vibrated by the ultrasonic generator US, and the split mold 3 is removed from the curved surface master 14 in the vibrated state. Release. After the mold release is completed, the vibration of the ultrasonic generator US is stopped. Due to the effect of ultrasonic vibration, the mold release can be performed smoothly, the fine pattern can be prevented from being damaged, and the separation mold release work efficiency is improved.

  Next, another example of the mold release step S6 will be described with reference to FIG. In the mold release process, when the mold 5 and the molded product are released, the pattern mold 24 of the mold 5 is released while being ultrasonically vibrated in order to release the mold smoothly. Therefore, the pattern mold 24 is provided with an ultrasonic generator US. The direction of ultrasonic vibration by the ultrasonic generator US can be arbitrarily set in the mold release direction L7 and the in-plane direction orthogonal to the mold release direction L7, and its amplitude is equal to or smaller than the size of the pattern to be transferred. After the pressure transfer and before the start of mold release, the pattern mold 24 is vibrated by the ultrasonic generator US, and the pattern mold 24 is released from the molded product 1 in the vibrated state. After the mold release is completed, the vibration of the ultrasonic generator US is stopped. Due to the effect of ultrasonic vibration, mold release can be performed smoothly, damage to the fine pattern can be prevented, and mold release work efficiency of the mold 5 can be improved.

  Next, another example of the pattern transfer molding step S5 will be described with reference to FIGS. In this pattern transfer molding process, the pattern portion 1b of the molded product 1 is formed using a material different from that of the other portion (core portion 1a) of the molded product 1. In the main molding step, first, as shown in FIG. 24A, the core portion 1a of the molded product 1 is molded using the lower mold 23 and the upper mold 24a for molding. Here, the upper mold 24a is a mold for molding a shape obtained by subtracting the pattern portion 1b of the surface layer including the shape pattern from the final molded product 1. After the core portion 1a is molded, the upper mold 24a is released.

  Subsequently, as shown in FIG. 24B, the pattern mold 24 is put on the core portion 1a held by the lower mold 23 and the mold is closed. Thereafter, the resin for the pattern portion 1b is filled to form the pattern portion 1b on the surface layer of the core portion 1a. The pattern mold 24 is the same as the above mold (see FIG. 13).

  Subsequently, as shown in FIG. 24 (c), the pattern mold 24 is released, and the molded product 1 is released from the lower mold 23 using an ejector 25 having an ejector bar 25 a provided in the lower mold 23. . As shown in the enlarged view, the molded product 1 includes a core portion 1a and a pattern portion 1b formed on the surface thereof.

  When the molded product 1 has such a double structure, the core portion 1a having a large volume is formed by using a low-cost general material, and the pattern portion 1b having a small surface layer is formed by using a highly functional material. Can do. In general, the cost of a molded product can be reduced by reducing the amount of high-functional materials that are expensive. Further, by using the core portion 1a as a material having good adhesion and the pattern portion 1b as a material having good water repellency, a molded product 1 having a high water repellency function can be obtained.

  Furthermore, in optical applications, in addition to controlling the optical characteristics based on the fine pattern on the surface, molding based on material properties by molding the core portion 1a and the pattern portion 1b using resins having different refractive indexes. The optical characteristics of the product 1 can be controlled. In this way, by making the material of the fine pattern part of the surface different from the material of the other parts, the range of selection of the molding material is widened, so the material that is expensive for the fine pattern part but optimal for pattern transfer It is possible to optimally allocate material costs for selecting materials and to develop new functions due to the synergistic effect of different materials in both parts. The present invention is not limited to the above-described configuration, and various modifications can be made.

The process flow figure of the molding transfer method concerning one embodiment of the present invention. (A) is a perspective view of a three-dimensional shape model of a molded product formed by the above-described molding transfer method, and (b) is a partial sectional view of (a). (A) is a perspective view of a curved surface shaped body showing a pattern-free state of a molded product formed by the above-described molding transfer method, and (b) is a partial sectional view of (a). (A) is a perspective view of a curved surface reconstructed body obtained by dividing and reconstructing a pattern-free curved surface of a molded product formed by the above-described molding and transfer method using surface elements, and (b) is a partial cross-sectional view of (a). Sectional drawing explaining the curved surface master shaping | molding process in a shaping | molding transcription | transfer method same as the above. (A) is a perspective view of the curved surface master in the same molding transfer method, (b) is a cross-sectional view of the curved surface master. (A) is a perspective view of a split mold used in the split pattern transfer step of the above-described molding transfer method, and (b) is a cross-sectional view taken along line AA of (a). The conceptual diagram explaining the division | segmentation pattern transfer process in a shaping | molding transfer method same as the above. (A) is a perspective view explaining in detail the same divided pattern transfer process, (b) is a perspective view of a curved surface master in the middle of the process. The perspective view of the pattern transfer curved surface master formed in the division | segmentation pattern transfer process same as the above, (b) is a partial cross section figure of the pattern transfer curved surface master. (A) is sectional drawing of the nested mold in the middle of electroforming explaining the shaping | molding die preparation process in a shaping | molding transcription | transfer method same as the above, (b) is a partial sectional view of (a). (A) is a sectional view of a nested mold created by the same mold making process, (b) is a partial sectional view of (a). Sectional drawing of the shaping | molding die used in a shaping | molding transcription | transfer method same as the above. (A) (b) (c) is sectional drawing of the shaping | molding die and molded article explaining the pattern transfer shaping | molding process in a shaping | molding transcription | transfer method same as the above. (A) is a perspective view of a molded product formed by the above-described molding transfer method, and (b) is a partial sectional view of (a). (A) is a perspective view of a curved surface reconstructed body in the above-described molding transfer method, (b) is a partial cross-sectional view of the curved surface reconstructed body, and (c) is a partially enlarged cross-sectional view of (b). (A) is a perspective view of a curved surface reconstructed body in the same molding transfer method, (b) is a partially enlarged perspective view of the curved surface reconstructed body, (c) is a further partially enlarged perspective view of (b). (A) is a perspective view which shows the other example of the curved surface master in the same shaping | molding transfer method, (b) is sectional drawing of the curved surface master. (A) is the partial cross section conceptual diagram which shows the other example of the division | segmentation pattern transfer process in the same mold transfer method, (b) is the partial cross section conceptual diagram which shows the detail of the pattern transfer in the same process. The partial cross-section conceptual diagram which shows the further another example of the division | segmentation pattern transfer process in a shaping | molding transfer method same as the above. The partial cross-section conceptual diagram which shows the further another example of the division | segmentation pattern transfer process in a shaping | molding transfer method same as the above. The partial cross-section conceptual diagram which shows the further another example of the division | segmentation pattern transfer process in a shaping | molding transfer method same as the above. Sectional drawing which shows the other example of the mold release process in the same shaping | molding transfer method. (A)-(c) is sectional drawing which shows the other example of the pattern transfer shaping | molding process in a shaping | molding transcription | transfer method same as the above in time series.

Explanation of symbols

1 Molded product 2 Curved surface master mold 3 Divided mold 5 Mold 10 Pattern (fine shape pattern)
11 Three-dimensional shape model 13a Surface element 14 Curved surface master 14a Coating layer 15 Pattern transfer curved surface master 21 Upper mold 22 Lower mold 23 Core mold 24 Pattern mold L0 Mold release direction S Curve

Claims (12)

In a molding transfer method for producing a molded product comprising at least a curved surface and molding and transferring a predetermined fine shape pattern on the curved surface,
A surface dividing step of dividing the curved surface into minute surface elements;
A curved surface master forming step of forming a curved surface master having the same shape as the molded product with the curved surface without the pattern,
A divided pattern transfer step of transferring the pattern to a portion corresponding to each surface element of the curved surface master using a divided mold having the pattern shape in a portion corresponding to each surface element;
A mold creating step for creating a mold using an electroforming method based on the curved surface master to which the pattern is transferred,
A pattern transfer molding step for transferring and molding the curved surface and a molded product having the pattern on the curved surface, using the mold created by the step,
And a mold release step of releasing the molded product transferred and molded in the above process.   In the surface dividing step, the three-dimensional shape model of the molded product is divided into the surface elements, and the shape of the pattern with respect to the releasing direction of the forming die is undercut at the time of releasing in the releasing step. The molding transfer method according to claim 1, further comprising a step of determining the division so as not to be related.   The surface dividing step includes a step of determining a position and a direction of each pattern such that a pattern included in each surface element is continuous with a pattern included in a surface element adjacent to the surface element. The molding transfer method according to claim 1 or 2.   The curved surface master molding step and the pattern transfer molding step are each performed using at least two molds, and one of the molds used in each of the processes is shared by both processes. The molding transfer method according to claim 3.   The molding transfer method according to any one of claims 1 to 3, wherein the curved surface master molding step includes a step of cutting a resin into a shape of the curved surface master.   In the division pattern transfer step, a thermoplastic resin is used as a material for forming the curved surface master, a transparent body is used as a material for forming the division mold, and the division mold made of the transparent body is transmitted through the thermoplastic resin. 6. The method according to claim 1, further comprising: partially heating the curved surface master by irradiating the curved surface master with energy rays, and transferring the pattern to the heated portion by the split mold. The molding transfer method according to any one of the above.   The division pattern transfer step uses a transparent thermoplastic resin as a material for forming the curved surface master, and partially heats the surface of the curved surface master by irradiating energy rays through the transparent curved surface master. The molding transfer method according to claim 1, further comprising a step of transferring the pattern to the heated portion by the split mold.   In the divided pattern transfer step, the curved surface master is created by stereolithography, the surface layer of the curved surface master is coated with a UV curable resin, the divided mold is pressed on the coating layer of the curved surface master, and the coating is applied with UV light. The molding transfer method according to any one of claims 1 to 5, further comprising a step of curing the layer.   The divided pattern transfer step includes a step of using a core-side die used together with the forming die in the pattern transfer forming step as a lower die that receives pressure applied by the divided die, in transferring the pattern by the divided die. The molding transfer method according to any one of claims 1 to 7, wherein   10. The divided pattern transfer process includes a step of releasing the divided mold while ultrasonically vibrating the divided mold when releasing the divided mold after pattern transfer by the divided mold. The molding transfer method according to any one of the above.   The mold release step includes a step of releasing the mold while ultrasonically oscillating the mold when releasing the mold and the molded product. Mold transfer method. The said pattern transfer molding process includes the process of forming the said pattern part of a molded article using the material different from the other part of the said molded article, The Claim 1 thru | or 11 characterized by the above-mentioned. Mold transfer method.

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