JP3853238B2 - Molding method and molding obtained by this method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for imparting a periodic structure to a substrate surface, and more particularly, to a method for imparting a structure having directionality and periodicity to a substrate surface. The present invention relates to a method for imparting a structure having a periodicity of 0.2 to 20 μm to a mold, and to a mold (optical film) for controlling the optical characteristics of the substrate surface obtained by the molding method.
[0002]
[Prior art]
In recent years, with the advancement of society, optoelectronics-related parts and devices have made significant progress. Among them, a display for displaying an image is remarkably spreading as a computer monitor device in addition to a conventional television receiver as a most important man-machine interface in multimedia. Among them, market demands for increasing the size and thickness of displays are increasing. Recently, for example, a liquid crystal display (LCD) has attracted attention as a display aiming at thinning and energy saving. In liquid crystal displays, many optical films or optical sheets (hereinafter referred to as films without distinction between films and sheets) are used. Various films such as a diffusion film, a polarizing film, a prism film, a reflective film, and a retardation film are used as functional films actually used in LCDs. The function of these films is to control the transmission and reflection of light, polarization, and retardation, and functional materials contained in the film, such as pigments, may play an important role in the control. Or, like a prism film, the shape of the surface may play an important role in controlling the properties of light. In other words, shaping on the film surface is an extremely important field that cannot be measured industrially.
[0003]
[Problems to be solved by the invention]
Examples of a method for imparting a fine structure to the surface include a method based on photoetching and a method of pressing a mold on the surface. The former is basically an extremely precise method used for microfabrication of semiconductors, and can be practically processed with extremely high precision on the order of submicrons, but on the other hand, it is suitable for processing a large area. However, the processing itself becomes very expensive. The method of pressing the mold is, for example, a method represented by a compact disc (CD) or digital versatile disc (DVD) stamper, and by pressing a hard material with an uneven relationship on the softened resin. It is a method of forming on the surface. Although this method is expensive, once the mold is manufactured, it is possible to form the mold on the surface, but it is still difficult to process a large area, that is, to a large sheet every leaf or film There was a difficulty that it was difficult to mold continuously.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. The present invention finds that the surface can be imparted with a uniform shape with directionality and periodicity by using the inherent properties of the material to “spontaneously” cause deformation on the surface, It has been completed. That is, the present invention is (1) a substrate in which a resin is coated on the surface of the substrate , wound around a cylindrical molded article, and coated on the surface by one or more of the following methods 1) to 4). giving stress to the cross-sectional shape of the resin coating film have a direction and periodicity, peak with the case where the roughness profile of the Fourier transform to the periodic component of 0.2~20μm the surface of the resin film A molding method characterized by the presence of
1) Method of applying heat 2) Method of irradiating light 3) Method of irradiating electron beam 4) Method of irradiating ion beam (2) The resin is a polyester resin, acrylic resin, silicone resin, urethane type The shaping method according to (1), which is any one of a resin, a phenol resin, an epoxy resin, or a fluorine resin.
(3) The molding method according to (1) or (2), wherein a crosslinking agent is added to the resin.
(4) The shaping method according to any one of (1) to (3), wherein the substrate is any one of polyethylene terephthalate, polymethyl methacrylate, polycarbonate, polyethylene, and polypropylene.
(5) A molded product obtained by the molding method according to any one of (1) to (4) .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The transparent polymer film that can be used for the substrate of the present invention preferably has appropriate mechanical properties, and the strength is preferably in the range of 0.5 kg or more per square millimeter. Below this, deformation of the film may become noticeable at the time of winding the film, etc. On the other hand, there is no particular restriction on the upper limit of strength, but practically 50 kg per square millimeter is practical. It is sufficient, and it is not always meaningful industrially to give the mischief more strength than this.
[0006]
Specific examples of the polymer film include polysulfone (PSF), polyethersulfone (PES), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethylene methacrylate (PMMA), polycarbonate (PC), and polyether. Examples include ether ketone (PEEK), polypropylene (PP), polyethylene (PE), liquid crystal polymer (LCP), and triacetyl cellulose (TAC). Among these, polyethylene terephthalate (PET) is balanced from the viewpoint of cost and heat resistance, and is particularly preferably used.
[0007]
Examples of the resin applied to the main surface of the polymer film include phenol-based, epoxy-based, polyester-based, acrylic-based, silicone-based, urethane-based, and fluorine-based resins. The phenolic resins include pure phenols and modified phenolic resins. Pure phenolic resins are obtained by the reaction of phenol and formaldehyde. The modified phenol resin is a combination of ester gum and pure phenol resin, and exhibits good resistance to water and alkali. More precisely, an epoxy-based resin is called an epichlorohydrin bisphenol resin, and is a chain structure compound having an aromatic group and a glycerol structure bonded by an ether bond. The polyester resin may be one using a polyester polymer in addition to the alkyd resin in which the polyester is modified with oil. Although alkyd resins may be considered part of polyesters, unsaturated polyesters are 1) free of fatty acids, 2) dihydric alcohols such as glycols are used in place of glycerin 3) It differs from alkyd resins in that it contains unsaturated difunctional acids. What is obtained from the condensation polymerization of glycol and a mixture of saturated and unsaturated dibasic acids such as phthalic acid and maleic acid is a linear polymer containing unsaturation in the main chain. The acrylic resin is obtained by polymerization or copolymerization of acrylic acid or methacrylic acid ester, and may be used in combination with melamine, epoxy, alkyd, and the like. A silicone-based resin is a polymerization resin of an organic polysiloxane, and has excellent heat resistance and chemical stability. In general, three types of urethane-based resins are known: amine catalyst two-component system, moisture-cured urethane, urethane oil and alkyd, and any of them can be used. The first two contain unreacted isocyanate groups and can be used for the final curing reaction in the coating. Fluorine-based resins have high molecular weight and are crystalline polymers, so they are difficult to dissolve in solvents. Therefore, they are used as water-dispersed or organic solvent-dispersed or powder paints, and they are baked at high temperatures to form a resin film. be able to.
[0008]
A crosslinking agent may be added to the resin, and isocyanate, melamine, or the like can be used. For the purpose of improving the solvent resistance of the coating film resin, it is preferable to add a crosslinking agent, but it is further preferable that the crosslinking reaction is not completely completed at the time of molding in order to easily give a periodic structure. . A preferred addition amount of the crosslinking agent is 5 to 35% by weight in the total resin, and a more preferred range is 10 to 20% by weight. Whether the cross-linking reaction has completely progressed can be determined, for example, by wiping the coated surface with a solvent such as MEK or toluene, and if it does not peel at all, it can be judged that the cross-linking has completely progressed. Can be confirmed as not progressing completely. More precisely, information on the degree of crosslinking can be obtained by immersing the shaped product in a solvent and analyzing the eluted part by GPC or the like. For example, if an uncrosslinked resin is detected, it can be seen that curing has not progressed completely. If the amount of the uncrosslinked resin is too large, the solvent resistance is inferior, and if it is too small, complete shaping becomes difficult, so 0.0001 to 5% by weight in the total resin is preferable, and further 0.001 to 2 % By weight is preferred, and more preferably 0.01 to 1% by weight. As a coating method, a bar coater method is suitable in the laboratory, and industrially, there are a gravure coater, a micro gravure coater, a reverse coater, a die coater, a lip coater and the like.
[0009]
The method of applying a curvature or stress to the substrate is not particularly limited, but it may be bent in a space, and in order to reproduce the curvature with good reproducibility, a method of winding around a cylindrical molded product is preferable. For example, a metal drum or the like can be suitably used. Regarding the curvature, 0.1 to 10 m is an appropriate range in terms of the circular radius portion of the cylindrical molded product, more preferably 0.3 to 5 m, and further 0.5 to 2 m. Even more suitable. If the curvature is too large, the directionality cannot be obtained, and if the curvature is too small, not only the area that can be processed at one time is reduced but also the period becomes too large, which is not preferable. Thus, the periodic structure appears along the direction in which the curvature is given. As a method of applying stress without applying curvature, there is a method of pulling or compressing a film, but in the case of a film, it is relatively easy to pull.
[0010]
As a method for causing deformation, 1) a method of applying heat, 2) a method of irradiating light, 3) a method of irradiating an electron beam, 4) a method of irradiating an ion beam, or a combination of 1) to 4) Can be mentioned. The method of deforming is generally a method of shrinking or expanding the resin. A method of shrinking is preferable. In the method of applying heat, after applying the resin, the entire substrate may be put into a high temperature furnace. It is possible to process the sheet with a sheet, and if a film roll is used, the film may be continuously placed in a high temperature furnace. Although the treatment temperature can not be said sweepingly because more different resins, it is preferable to proceed rapidly raising than the glass transition temperature. If it is raised too much, decomposition of the resin occurs and must be avoided. Moreover, in order to perform shrinkage | contraction effectively, it is good to put a crosslinking agent like isocyanate and a melamine into resin beforehand. Visible light, infrared rays, and ultraviolet rays can be used as a method of irradiating light, but ultraviolet rays have the highest energy and can be suitably used. Can be also be irradiated with an electron beam or an ion beam obtain the same effect, electron beam irradiation apparatus and an ion beam irradiation apparatus is so Gakari large, for example, depositing a metal or the like by a vapor deposition apparatus using an electron beam Irradiation of the electron beam onto the resin surface also serving as can be suitably performed. In the sputtering apparatus, since the ion beam and the electron beam are simultaneously irradiated, the formation and shaping of the metal layer can be performed at the same time, which is also convenient. The energy of the electron beam or ion beam is preferably about 0.3 keV to 30 keV. If it is too low, the effect of irradiation does not appear, and if it is too high, the resin deteriorates, which is not preferable.
[0011]
For observation of the surface shape, a phase contrast microscope or an atomic force microscope can be used in addition to a normal optical microscope, and the shape period can be determined by using a so-called stylus roughness meter to quantify the shape. Sex can also be measured. In addition, the surface shape can be evaluated using a three-dimensional measuring machine. Further, a reflective metal layer or the like may be formed on the surface in order to make the surface shape easy to see optically. As a method for forming the metal layer, vacuum deposition, sputtering, plating, or the like can be applied, but these methods are not particularly essential. If a rainbow-like reflected light can be observed when a metal layer is formed and viewed under white light, for example, it is easy to have a periodic structure on the surface in the order of μm. Can be determined. Further, by changing the viewing direction, if that rainbow-like reflected light or observed, to Any failure observed, that is, to say that there is directionality to the periodic structure. The periodic structure referred to in the present invention means that when the surface roughness profile is H (x), there is a peak in the frequency component that appears when Fourier transforming H (x). Ki De be read as periodic component by taking the inverse of the frequency components, the periodic component can confirm the periodicity Knowing that a 0.2 to 20.
[0012]
【Example】
Next, the present invention will be specifically described with reference to examples. The present invention is not limited by the following examples.
Example 1
Dissolve 100 parts by weight of a polyester-based resin (Toyobo Byron 500) in MEK, add 20 parts by weight of melamine resin (manufactured by Dainippon Ink, Company Name), and add 0.25 parts of catalyst (paratoluenesulfonic acid). A part by weight was added, and the resultant was coated on a polyethylene terephthalate film (thickness: 100 μm) so as to have a dry thickness of 5 μm with a bar coater. The film was dried at 100 ° C. for 5 minutes. Next, this film was wound around a cylinder having a diameter of 0.3 m and placed in an oven at 180 ° C. for 1 minute. It was taken out, and silver was deposited to about 100 nm with a resistance heating type vacuum deposition apparatus, and reflected light was confirmed under white light. When confirmed from the winding direction, it looked like a rainbow, but when confirmed from the direction perpendicular to the winding direction, no reflected light was seen in the rainbow, so a directional periodic structure was formed on the surface. It was confirmed.
[0013]
(Example 2)
A coating film was formed on a PET film in the same manner as in Example 1. The film was further dried under the same conditions as in Example 1, wound around a cylinder, and then irradiated with light centered on ultraviolet rays for 5 minutes with a QUV panel (QUV). Silver was deposited on this film with a resistance heating type vacuum deposition apparatus to a thickness of about 100 nm, and reflected light was confirmed under white light. When confirmed from the winding direction, it looked like a rainbow, but when confirmed from the direction perpendicular to the winding direction, no reflected light was seen in the rainbow, so a directional periodic structure was formed on the surface. It was confirmed.
[0014]
Example 3
A coating film was formed on a PET film in the same manner as in Example 1. This film was further dried under the same conditions as in Example 1 and wound around a cylinder. Then, the film was placed in an electron beam deposition apparatus, and silver was deposited to a thickness of 100 nm while irradiating the electron beam with an acceleration voltage of 10 KV. After taking out the film from the electron beam evaporation system, it looked like a rainbow when confirmed from the winding direction, but when seen from a direction perpendicular to the winding direction, no reflected light was seen as a rainbow. It was confirmed that a certain periodic structure was formed on the surface.
[0015]
Example 4
A coating film was formed on a PET film in the same manner as in Example 1. This film was further dried under the same conditions as in Example 1, wound around a cylinder with a radius of 0.5 m, and then placed in a sputtering apparatus, and a voltage of 400 V was applied to sputter silver to 100 nm. Surface and electron beam were irradiated. After taking out the film from the sputter device, it looked like a rainbow when confirmed from the winding direction, but when seen from the direction perpendicular to the winding direction, the reflected light was not visible, so there was a direction. It was confirmed that the periodic structure was formed on the surface. When the surface was observed with an optical microscope, it was observed that periodic structures of about 10 μm were arranged vertically as shown in FIG.
[0016]
(Example 5)
Add 20 parts by weight of melamine resin to 100 parts by weight of urethane-based resin paint (ADEKA polyether), add 0.25 parts by weight of catalyst (paratoluenesulfonic acid), and dry with a bar coater. It was applied on a polyethylene terephthalate film (thickness: 100 μm) so as to have a thickness of 5 μm. The film was dried at 100 ° C. for 5 minutes. Next, this film was wound around a cylinder having a diameter of 0.3 m and placed in an oven at 180 ° C. for 1 minute. It was taken out, and silver was deposited to about 100 nm with a resistance heating type vacuum deposition apparatus, and reflected light was confirmed under white light. When confirmed from the winding direction, it looked like a rainbow, but when confirmed from the direction perpendicular to the winding direction, no reflected light was seen in the rainbow, so a directional periodic structure was formed on the surface. It was confirmed.
[0017]
(Example 6)
Add 15% by weight of aliphatic polyisocyanate curing agent (Dainippon Ink) to saturated polyester resin paint (manufactured by Takamatsu Yushi), add solvent with 1: 1 mixing ratio of toluene and MEK, and have a viscosity of 40 cpois. It was adjusted to become. This coating agent was applied to a 188 μm polyester film to a thickness of 5 μm and dried at 140 ° C. for 10 minutes. The thickness after drying was 4 μm. The film was set in a magnetron sputtering apparatus in a state of being wound around a cylinder having a diameter of 1 m. In order to irradiate the surface of the film with ion beams, a high frequency power of 1 W / square centimeter was applied in the reverse sputtering mode to generate an argon discharge, which was held for 3 minutes. Thereafter, a silver film having a thickness of 120 nm was taken out using the same sputtering apparatus. When the surface is observed under white light, a rainbow-colored reflection is seen. Further, when an optical micrograph of the surface was taken, it was found that a structure with a wavy period was obtained as shown in FIG.
[0018]
【The invention's effect】
A surface shape of a periodic structure having a micron-order directionality can be easily obtained.
[Brief description of the drawings]
Fig. 1 Photo of periodic structure with directionality Fig. 2 Photo of periodic structure with directionality

Claims (5)

A resin is coated on the surface of the substrate , wound around a cylindrical molded product, and stress is applied to the substrate coated with the resin by one or more of the following methods 1) to 4). vehicles that cross-sectional shape have a direction and periodicity, characterized in that the peak with a time of Fourier transform of the roughness profile of the periodic component of 0.2~20μm the surface of the resin film is present Mold method.
1) Method of applying heat 2) Method of irradiating light 3) Method of irradiating electron beam 4) Method of irradiating ion beam The molding method according to claim 1, wherein the resin is any one of a polyester resin, an acrylic resin, a silicone resin, a urethane resin, a phenol resin, an epoxy resin, or a fluorine resin. The shaping method according to claim 1, wherein a crosslinking agent is added to the resin. The shaping method according to any one of claims 1 to 3, wherein the substrate is any one of polyethylene terephthalate, polymethyl methacrylate, polycarbonate, polyethylene, and polypropylene. A shaped product obtained by the shaping method according to claim 1.

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