JP2018183879A - Laminated film and method for producing laminated film, and molded article on which laminated film is transferred - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film which reproduces a metal design without using metal, and can impart a design of a half mirror to a resin molding enabling use both infrared transmission and a touch panel.SOLUTION: Low refractive index layers 107 and high refractive index layers 108 having different refractive indexes are alternately laminated on base layers 105 and 106 having unevenness thereon, a refractive index of the alternately laminated low refractive index layers 107 and high refractive index layers 108 is 0.15 or more, at least unevenness is provided on any interface between the low refractive index layers and the high refractive index layers, as for light reflected on the interfaces of each layer of the low refractive index layers and the high refractive index layers, external light approached from a surface of a molding product irregularily scatters therein the molded product by density unevenness of a fine uneven part of submicron formed between the respective layers and an aggregate of the low refractive index and high refractive index fine particles.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated film of a metal design among laminated films.

  A metal design is a metal part coated with a metal material by metal vapor deposition, metal sputtering, metal plating, etc., or a part with a unique texture that has changed over time due to oxidative degradation of the metal itself. Defined as a design. Specifically, it is defined as a design with high reflectivity of the incident light on the component surface and high brightness.

  As a method of reproducing the metal design on the surface of the resin part, use a method in which metal deposition, metal sputtering, metal plating, etc. are directly coated on the resin surface, or metal deposition, metal sputtering, metal plating are coated on the film surface. In general, the film itself is transferred to the resin, or a metal design is made by transferring a part of the metal layer coated on the film to the resin surface.

  In recent years, decorating needs for resin parts have become more diversified and complicated, and there is a tendency to give a plurality of performances to resin parts by adding functionality together with metal design. Among them, needs that cannot be realized by a metal design using a conventional metal material for resin parts include the combined use of a metal design and an infrared transmission function and the combined use of a touch panel function.

  In order to realize this need, there is a metal-type laminated film that controls the wavelength and reflectance of light by controlling the refractive index, film thickness, and number of laminated layers of a resin material, and reproduces a metal design without using a metal. However, this laminated film is insufficient to include all metal designs.

  A conventional laminated film that reproduces a metal design without using a metal can reproduce the metal design by controlling the light reflectivity by alternately laminating two different resin materials with different refractive indexes. doing. By using this metalless laminated film, a metal design can be imparted together with an infrared transmission function and a touch panel function.

  Patent Document 1 discloses a metal-like laminated film shown in FIG.

  This laminated film 200 includes a structure in which 200 or more resin layers A201 and resin layers B202 are alternately laminated, and gradually increases from 120 nm to 320 nm as the relative thickness of the layers goes from one surface to the opposite side. It is a metal film of a half mirror including a layer structure in which the thickness is increased. Further, the resin layer A is polyethylene terephthalate or polyethylene naphthalate, and the resin layer B is a polyester containing spiroglycol and cyclohexanedicarboxylic acid. The resin layer A and the resin layer B are alternately laminated and manufactured by biaxial stretching. A continuous film.

  When giving a metallic design to the surface of the resin molded product using the laminated film, the adhesive layer is printed on one side of the laminated film 200, and then insert molding or an adhesive layer is provided on one side of the laminated film 200. Later, there is a method of transferring the laminated film 200 by vacuum / pressure forming. In the case of a resin molded product using the laminated film 200, the outermost surface of the resin molded product has a configuration in which the laminated film 200 is disposed.

Japanese Patent No. 5176319

  FIG. 6 (a) shows an insert molded product created using the laminated film 200.

  203 is an adhesive layer made of an adhesive for injection molding resin, and 204 is a resin layer formed by injection molding. A partially enlarged view in FIG. 6 is shown in FIG. 205 is external light incident from the surface of the laminated film 200, and 206 is specularly reflected light reflected from the surface of the laminated film 200 and the interfaces between the resin layers A201 and B202. Reference numeral 207 denotes interference light in which the specular reflection light 206 reflected from the surface of the laminated film 200 and the interfaces of the resin layers A and B is interfered and strengthened.

  The surface of the laminated film 200 has high smoothness, and the resin layer A201 and the resin layer B202 are also made of a homogeneous resin. The external light 205 incident on the laminated film 200 is not scattered, and the surface of the laminated film 200 is not scattered. In addition, the ratio of the specular reflection light 206 is high at the interface between the resin layers A201 and B202, and the specular reflection light 206 at the interface between the layers interferes and strengthens, thereby forming a metal design with high specularity. Further, the laminated film 200 is formed in a state where 200 layers or more of the resin layer A201 and the resin layer B202 are laminated, and the film thickness is changed in the thickness direction. It is configured to be reflected, and a silver half mirror metal design is formed. Therefore, it is possible to reproduce designs such as metal vapor deposition, metal sputtering, metal plating, etc. with a single color and high brightness and specularity.

  However, the color difference occurred due to the state that the specularity deteriorated due to roughening of the metal surface deteriorated by oxidation over time or part of the metal surface, or the color changed within the metal surface depending on the degree of surface oxidation. It is difficult to reproduce the design of an oxidatively deteriorated metal over time when the color becomes uneven. For example, oxidized brass and copper oxide are examples.

  The present invention solves the above-described conventional problems, and reproduces a metal design that has been oxidized and deteriorated over time without using a metal, and in addition to the metal design, a resin molded product that can be used in combination with infrared transmission and a touch panel. It aims at providing the laminated film which provides a metal design.

  In order to achieve the above object, the laminated film of the present invention has a plurality of resin layers having different refractive indexes alternately laminated on a base layer having irregularities on the surface, and the resin layers are alternately laminated. The refractive index difference is 0.15 or more, and the alternately laminated resin layers are a low refractive index layer containing low refractive index nanoparticles and a high refractive index layer containing high refractive index nanoparticles, respectively. The total number of layers of the low refractive index layer and the high refractive index layer is 10 or more, and has at least unevenness at any interface between the low refractive index layer and the high refractive index layer.

  Further, the plurality of resin layers are formed by alternately laminating two or more types of resin layers having different refractive indexes with an average film thickness between 50 nm and 150 nm, and the number of resin layers is 10 or more and The resin layer formed on the concavo-convex part is formed so that the film thickness is thicker than the average film thickness of the resin layer at the concave part and the film thickness is thinner than the average film thickness of the resin layer at the convex part. It is comprised in the form which has an uneven film thickness unevenness inside.

  Further, the plurality of resin layers are a low refractive index layer and a high refractive index layer, and the composition of the low refractive index layer contains a certain amount of low refractive index nanoparticles in the resin layer, and a protective layer or a hard coat layer The material structure has a lower refractive index than the anchor layer. Since the low refractive index layer is formed by wet coating, the low refractive index layer is formed using a low refractive index coating liquid composed of low refractive index nanoparticles, a resin, a solvent, an auxiliary agent and the like. The high refractive index layer contains a certain amount of high refractive index nanoparticles in the resin layer, and has a material composition having a refractive index higher than that of the protective layer, the hard coat layer, or the anchor layer. Since the high refractive index layer is also formed by wet coating, the high refractive index layer uses a high refractive index coating liquid composed of high refractive index fine particles, a resin, a solvent, and an auxiliary agent.

  The difference in refractive index between the low refractive index layer and the high refractive index layer is preferably at least 0.15 or more, more preferably 0.2 or more and 0.6 or less, in terms of nd (550 nm). If the refractive index difference is smaller than 0.15, the reflectivity between the low refractive index layer and the high refractive index layer becomes weak, and the number of layers for obtaining the brightness necessary for the metallic tone increases and the film cost increases. . On the other hand, if the refractive index difference is larger than 0.6, it is difficult to obtain a commercially available material, making it difficult to procure the material during mass production.

  The molded product created using the laminated film of the present invention is a laminate of 10 or more low refractive index layers and high refractive index layers, and the light reflected at each interface between the low refractive index layer and the high refractive index layer is: External light entering from the surface of the molded product is not caused by unevenness formed between the layers and uneven refractive index formed by the agglomeration of low refractive index nanoparticles and high refractive index nanoparticles in each resin layer. The structure is reflected by the rules.

  As a result, the amount and direction in which the external light entering from the surface of the molded product is reflected is uneven in the surface, and the amount of reflected light and the reflected color are uneven in the appearance of the molded product. For controlling the wavelength of light to be reflected, that is, the color of the light, the low refractive index layer and the high refractive index layer are calculated in advance by thin film interference optical simulation software, and the low refractive index layer and the high refractive index layer are smooth surfaces. When forming the film, the required refractive index and film thickness are calculated and adjusted with the coating conditions assuming the film thickness when forming on a smooth surface, and the peak of the reflection wavelength is adjusted to the target reflection wavelength such as yellow or red Include.

  By coating the low refractive index layer and the high refractive index layer under the conditions to achieve the desired film thickness, the appearance of yellow or red reflected color appears, while the unevenness of each layer and the low refractive index in the low refractive index layer The light reflection state changes due to uneven refractive index in each layer due to the influence of the aggregates of nanoparticles and high refractive index nanoparticles in the high refractive index layer. It becomes possible to make a metal-like molded product that has non-uniform reflection inside.

  According to this configuration, a plurality of resin layers having different refractive indexes are alternately laminated on the base layer, and the refractive index difference between the alternately laminated resin layers is 0.15 or more, and the resin layers are alternately laminated. The resin layer is a low refractive index layer containing low refractive index nanoparticles and a high refractive index layer containing high refractive index nanoparticles, respectively, and the total number of layers of the low refractive index layer and the high refractive index layer is 10 A metal surface that is formed of more than one layer and has at least unevenness at some interface between the low refractive index layer and the high refractive index layer, so that it is oxidatively deteriorated over time, which is difficult to reproduce with conventional metal-like decorative films. It is possible to reproduce the design of the metal design, and a molded product of the metal design that is oxidized and deteriorated without metal on the surface of the resin part. By using the laminated film of the present invention, it is possible to provide a molded product of a metal design that is stably oxidized and deteriorated at a low cost on the surface of a resin component.

Sectional drawing and (b) partial enlarged view of the insert film which has (a) metallic tone laminated film in Embodiment 1 of this invention (A)-(h) Explanatory drawing of an in-mold molding process (A) Cross-sectional view and (b) partial enlarged view of a molded product to which the laminated film in Embodiment 1 of the present invention is transferred (A) Cross-sectional view and (b) Partial enlarged view of a molded product to which a transfer layer of a metallic laminate film according to Embodiment 2 of the present invention is transferred Cross section of conventional laminated film (A) Cross-sectional view of insert molded product and (b) Partial enlarged view created using conventional laminated film

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
Fig.1 (a) shows the insert film 100 which has the transfer layer 102 as a laminated | multilayer film of the metal design in Embodiment 1 of this invention.

  The insert film 100 in FIG. 1 is a strip-like continuous film. The insert film 100 includes a carrier layer 101 that is not transferred to the molded product, and a transfer layer 102 that is formed on the carrier layer 101 and transferred to the surface of the molded product.

  The carrier layer 101 includes a base film 103 and a release layer 104 between the base film 103 and the transfer layer 102.

  The base film 103 is made of PET, an acrylic film or the like that plays a role of continuously supplying the transfer layer 102 into the mold. The thickness of the base film 103 is desirably used between 20 μm and 100 μm. When it is thinner than 20 μm, the film itself is easily wrinkled and easily broken. On the other hand, when the thickness is greater than 100 μm, the roll film having the same number of windings is thicker and heavier than a thin film, resulting in poor handling and a high base film cost. In this example, the base film 103 has a surface in which filler is dispersed and the surface is uneven. A transfer layer 102 is formed on one side of the base film 103 with a release layer 104 interposed therebetween.

  The transfer layer 102 includes a protective layer or hard coat (HC) layer 105, a low refractive index layer 107, a high refractive index layer 108, a concealing layer 109, and an adhesive layer 203, which are stacked in multiple layers. An anchor layer 106 is formed on the protective layer or hard coat (HC) layer 105 as necessary. If necessary, the peeling layer 104, the protective layer or the HC layer 105, and the anchor layer 106 may contain fine particles for adjusting irregularities.

  The protective layer or HC layer 105 protects the surface of the molded product to which the transfer layer 102 has been transferred and imparts hardness to the surface. The low refractive index layer 107 is a reflective layer related to the reflection wavelength and reflectance of the transfer layer 102. The high refractive index layer 108 is a reflective layer related to the reflection wavelength and reflectance of the transfer layer 102, as with the low refractive index layer 107. The low-refractive index layers 107 and the high-refractive index layers 108 are alternately stacked in the transfer layer 102, and are formed with a film thickness and the number of layers determined for each reflection wavelength and reflectivity. Either the low refractive index layer 107 or the high refractive index layer 108 may be laminated first. At least one of the resins constituting the low refractive index layer 107 and the high refractive index layer 108 contains a thermosetting resin. Further, the peak wavelength of regular reflectance on the surface of the transfer layer 102 is in the visible light region of 400 nm or more and 780 nm or less.

  The anchor layer 106 serves to connect the protective layer or the HC layer 105 and the low refractive index layer 107. Note that the anchor layer 106 may be omitted when the protective layer or the HC layer 105 also serves as the anchor layer 106. In other words, the base layer serving as a base on which the low refractive index layer 107 and the high refractive index layer 108, which are resin layers, are alternately stacked is configured by the protective layer or HC layer 105, or the protective layer or HC layer 105 and the anchor layer 106. Is done.

  The concealing layer 109 is a black concealing layer for absorbing light in the lowermost layer of either the low refractive index layer 107 or the high refractive index layer 108. The adhesive layer 203 serves to bond the transfer layer 102 and the molded product to which the transfer layer 102 has been transferred. When the adhesive layer 203 is black and has a concealing property, or when a black resin is used as the injection molding resin, or when the concealing layer 109 is configured so that light from the surroundings does not enter after the injection molding resin layer, the concealing layer 109 is used. Even if there is not, there is no problem because the light after the molded resin layer becomes dark and the light entering from the surface of the molded product is absorbed after the injection molded resin. In that case, the adhesive layer 203 may be provided directly after the final layer of the low refractive index layer 107 or the high refractive index layer 108.

  As described above, the insert film 100 of the present invention is composed of a plurality of layers. Further, in FIG. 1A, the layer thickness between the peeling layer 104 and the adhesive layer 203 is preferably formed between 5 μm and 30 μm, but particularly if the same effect can be obtained outside the above range. It is not limited to the said range.

  The roughness of the surface of the protective layer, the HC layer 105, or the anchor layer 106 forming either the low refractive index layer 107 or the high refractive index layer 108 is preferably an arithmetic average roughness Ra of 0.05 or more and 0.5 or less. When Ra is smaller than 0.05, the surfaces of the low refractive index layer 107 and the high refractive index layer 108 become too smooth, and uneven irregularities are formed in the plane of the low refractive index layer 107 and the high refractive index layer. hard. Further, when Ra is larger than 0.5, the unevenness in the plane of the low refractive index layer 107 and the high refractive index layer 108 becomes large, light scattering is strong, and regular reflection light is weakened, so that the brightness necessary for the metallic tone is sufficient. I can't get it.

  Regarding the formation method of the other layers except the low refractive index layer 107 and the high refractive index layer 108, it can be formed by gravure coater, comma coater, roll coat, gravure printing, screen printing, ink jet printing, or the like. The low refractive index layer 107 and the high refractive index layer 108 need to be formed by precision coating with a gravure coater because each layer needs to be formed with a precise film thickness on the order of submicrons.

  In the manufacture of the insert film 100, first, a protective layer having uneven unevenness on the surface of the base film 103, or a low refractive index coating solution with a wet coating on the HC layer 105 or the anchor layer 106 is targeted. Coat and heat dry. Thereafter, the high refractive index coating liquid for forming the high refractive index layer 108 is coated on the dried low refractive index coating liquid so as to have a target film thickness and is thermally dried. Thereafter, the low refractive index coating solution is again applied onto the dried high refractive index layer so as to have a target film thickness and dried. In this manner, the low refractive index layer 107 and the high refractive index layer 108 are alternately stacked to form 10 layers or more. Since the low refractive index layer 107 and the high refractive index layer 108 are formed by wet coating, the low refractive index layer 107 and the high refractive index layer 108 are coated on the uneven surface of the protective layer or the HC layer 105 or the anchor layer 106. When the refractive index layer 108 is coated and thermally dried, the film thickness after drying changes due to uneven unevenness, and the film thickness is thicker than the average film thickness at the concave part, and the film thickness is larger than the average film thickness at the convex part. Are laminated in a thin state.

  FIG. 1B shows a partial enlargement in which a part of the transfer layer 102 is enlarged in the alternately laminated portion of the low refractive index layer 107 and the high refractive index layer 108.

  An anchor layer 106 is formed on the protective layer of the uneven surface or the HC layer 105, the surface of the anchor layer 106 is an uneven surface, and the low refractive index layer 107 or the high refractive index layer 108 is formed thereon. Laminated. In FIG. 1B, the case where the low refractive index layer 107 is first laminated on the anchor layer 106 will be described.

  Since the low refractive index layer 107 is formed by wet coating with a gravure coater on the anchor layer 106 on which the uneven uneven surface is formed, the coating liquid for forming the low refractive index layer 107 has a viscosity in an appropriate state containing a solvent. Use the adjusted liquid. The low refractive index layer 107 is applied with a gravure plate along the uneven portion of the anchor layer 106. Thereafter, after the solvent is removed through a drying process, only the solid component of the low refractive index layer 107 remains, and the film of the low refractive index layer 107 is formed along the surface irregularities of the final anchor layer 106. In the concave portion of the anchor layer 106, the film thickness is easily formed with respect to the surroundings, and on the contrary, the convex portion of the anchor layer 106 is easily formed with a thin film with respect to the surroundings. As a result, the low refractive index layer 107 is also formed with a submicron order film having unevenness in the surface.

  Next, the high refractive index layer 108 is also formed by a gravure coater, and through the same process, the film of the high refractive index layer 108 also has subsurface irregularities in the plane along the irregularities on the low refractive index layer 107. A micron order film is formed. The low refractive index layer 107 and the high refractive index layer 108 are alternately laminated using a gravure coater with a target average film thickness according to the specific reflection wavelength and the required reflectance. The average film thickness per layer of each of the low refractive index layer 107 and the high refractive index layer 108 is 50 nm or more and 150 nm or less.

  Eventually, as the distance from the anchor layer 106 increases, the minute irregularities in the surface of the low refractive index layer 107 and the high refractive index layer 108 gradually approach a smooth surface as the distance from the anchor layer 106 increases.

  The details of the transfer type insert film 100 produced in the present invention will be described.

  As the base film 103, an industrial grade PET film was used, and a base film having an average thickness of 50 μm and containing a filler therein was used. The release layer 104 was formed of a melamine resin material with an average film thickness of 1 μm after drying. The HC layer 105 was formed of an after-curing type ultraviolet curable acrylic resin material so that the average film thickness after drying was 5 μm. The anchor layer 106 was formed using a two-component curable acrylic urethane resin material so that the average film thickness after drying was 2 μm.

  The low refractive index layer 107 is formed using a coating solution for forming a low refractive index layer in which a silicone resin and hollow silica having an average particle diameter of 50 nm are dispersed, and the refractive index nd is 1.33 and the average film thickness is 130 nm. It was formed as follows. As the low refractive index nanoparticles, magnesium fluoride, cryolite or the like may be used in addition to the hollow silica, and there is no need to be limited as long as the same effect can be obtained.

  The high refractive index layer 108 is formed by using a coating liquid for forming a high refractive index layer in which zirconia having an average particle diameter of 50 nm is dispersed in an after-curing type ultraviolet curable acrylic resin, and the refractive index nd is 1.63. The average film thickness was 85 nm. In addition to zirconia, titanium oxide, zinc oxide, or the like may be used as the high refractive index nanoparticles, and there is no need to be limited as long as the same effect can be obtained.

  The low refractive index layer 107 and the high refractive index layer 108 were alternately laminated by a gravure coater, and the low refractive index layer 107 and the high refractive index layer 108 were formed in a total of 10 layers. The difference in refractive index between the low refractive index layer 107 and the high refractive index layer 108 is at least 0.15 or more, more preferably 0.2 or more and 0.6 or less, in terms of nd (550 nm). If the refractive index difference is smaller than 0.15, the reflectivity between the low refractive index layer 107 and the high refractive index layer 108 becomes weak, and the number of layers for obtaining the brightness necessary for the metallic tone increases, and the film cost increases. Get higher. On the other hand, if the refractive index difference is larger than 0.6, it is difficult to obtain a commercially available material, making it difficult to procure the material during mass production.

  The number of laminated layers varies depending on the wavelength to be reflected and the required reflectance, but the total number of alternately laminated low refractive index layers and high refractive index layers is preferably in the range of 10 to 60 layers. More preferably, it is 10 layers or more and 40 layers or less. When the number of layers is less than 10 layers, it is difficult to obtain sufficient reflectivity and brightness necessary for metallic tone, and when the number of layers exceeds 60 layers, the reflectivity of the film and the molded product surface where the reflected light reflected between each layer changes. This is because there is no need for further lamination.

  When the difference in the refractive index between the low refractive index material and the high refractive index material to be used is small, the number of stacks for obtaining the reflectance necessary for the metallic tone increases, and conversely the refractive index difference As the number increases, the number of stacked layers can be reduced. Therefore, if the same effect can be obtained outside the above range, there is no problem outside the above range.

  Thereafter, the concealing layer 109 was printed by screen printing using a black ink of a two-component curable urethane resin so that the average film thickness after drying was 4 μm. Finally, the adhesive layer 203 is printed by screen printing with a urethane vinyl thermoplastic adhesive containing a copolymer of vinyl chloride resin and vinyl acetate resin so that the average film thickness after drying is 4 μm by screen printing. did. The peak wavelength of the reflectance of the decorative film 100 obtained by calculation with analysis software for optical simulation is a gold color that reflects a yellow wavelength near 600 nm when a regular reflectance of 5 ° is measured from the base film 103 side. An insert film 100 having a near brightness was obtained.

  In another prototype, the low refractive index layer 107 has a refractive index nd of 1.33, an average film thickness of 130 nm, and the high refractive index layer 108 has a refractive index, as calculated by the analysis software for optical simulation as described above. In the decorative film 100 in which the nd is 1.63 and the average film thickness is alternately formed with a gravure coater so that the average film thickness becomes 115 nm, and the low refractive index layer 107 and the high refractive index layer 108 are formed to be a total of 10 layers. The peak wavelength of the reflectance was obtained by measuring a specular reflectance of 5 ° from the base film 103 side to obtain a decorative film 100 having a copper-like brightness reflecting an orange-red wavelength near 725 nm.

  Next, an in-mold molding manufacturing process for transferring the transfer layer 102 of the insert film 100 to the surface of the molded product will be described.

  First, in the process of FIG. 2A, the transfer type insert film 100 is sent to a predetermined position between the fixed mold 1 and the movable mold 2 by using the foil feeding device 3. At this time, the transfer type insert film 100 is arranged so that the base film 103 faces the movable mold 2. Further, the insert film 100 may be preheated with a heater (not shown) and then fed into the mold so that the film can be easily molded into the mold.

  Next, after the feeding of the insert film 100 to a predetermined position is completed, in the step of FIG. 2B, the transfer type insert film 100 is sucked through the suction hole 4 formed in the cavity surface of the movable mold 2 and is movable. The insert film 100 is shaped on the cavity surface of the mold 2. At that time, the outer periphery of the insert film 100 is fixed and positioned by a film pressing mechanism (not shown).

  Thereafter, in the step of FIG. 2C, the movable mold 2 is moved and clamped.

  Next, in the step of FIG. 2D, the molten resin 6 is injected from the gate 5 of the fixed mold 1 toward the adhesive layer 203 of the insert film 100, and the molten resin 6 is filled in the cavity in the mold. .

  In the step of FIG. 2E, when the filling of the molten resin 6 is completed, the molten resin 6 is cooled to a predetermined temperature.

  In the step of FIG. 2F, when the movable mold 2 is moved and the mold is opened and the in-mold molded product 7 is taken out, the carrier layer 101 of the transfer-type metallic film is peeled off from the in-mold molded product 7 and the transfer layer 102 is removed. As a result, the protective layer or the HC layer is transferred to the outermost surface of the in-mold molded product 7.

  Thereafter, in the step of FIG. 2G, the protruding pin 8 on the fixed mold 1 side is pushed out to take out the molded product 7 from the mold.

  In the step of FIG. 2 (h), the base film 103 as the carrier layer 101 of the insert film 100 and the peeling layer 104 are adsorbed in the cavity of the movable mold 2 in the suction hole 4 of the movable mold 2 in preparation for the next molding. The insert film 100 used for the next molding is fed to a predetermined position by the foil feeding device 3, and this operation is repeated to enable continuous molding. In the case of the in-mold molding method, the base film 103 serves as a carrier for feeding the transfer layer 102 into the mold and is not transferred to the molded product. Therefore, the surface of the molded product can be obtained simply by taking out the in-mold molded product 7 from the mold. Since the transfer layer 102 is transferred to the film, a film preform and a trimming step after molding are not required. Therefore, productivity is high, and a molded product can be produced stably and efficiently at low cost.

  FIG. 3A shows a cross-sectional view of a molded product 110 created by transferring the transfer layer 102 of the insert film 100.

  The molded product 110 was obtained by forming the resin 6 by injection molding using ABS resin with the insert film 100 having the laminated film of the present invention using a general in-mold molding die. The injection molding resin may be appropriately selected according to the use, such as PC, PMMA, PP, etc. instead of ABS, and the adhesive layer 203 may be appropriately selected according to the injection molding resin.

  FIG. 3B is a detailed cross-sectional view showing a partially enlarged transfer layer 102 transferred to the surface of the molded product 110 shown in FIG.

  205 is external light incident from the surface of the molded product, and 206 is regular reflection light that the external light 205 reflects on the surface of the molded product and inside the molded product. Reference numeral 207 denotes interference light in which the reflected light interferes inside the molded product, and 208 denotes diffuse reflected light in which the external light 205 is diffused on the surface of the molded product or inside the molded product.

  By using the insert film 100 of the present invention, the external light 205 incident from the outermost surface of the molded product 110 is reflected by the unevenness on the surface of the protective layer or the HC layer 105, and the ratio of the regular reflection light 206 of the external light 205 is reduced. Part of it becomes diffusely reflected light 208. Thereby, the glare on the surface of the molded product 110 is reduced. In the molded product 110, uneven portions are unevenly present, and the external light 205 incident on the molded product 110 is specularly reflected in the same manner as the external light 205 generated on the surface of the molded product 110 even in the internal uneven portions. 206 and diffused reflected light 208 are separated.

  For this reason, reflection due to a difference in refractive index that repeatedly occurs between the low-refractive index layer 107 and the high-refractive index layer 108 inside the molded product 110 causes the incident external light 205 to form stable regular reflection light 205 within the surface. It is difficult to produce regular reflected light 205 that is uneven within the surface due to the difference in the amount of unevenness depending on the location. As a result, in the reflection of the external light 205 that repeatedly occurs between the low refractive index layer 107 and the high refractive index layer, the regular reflection light 206 becomes non-uniform in the plane, and therefore the interference light 207 that appears on the surface of the molded product 110. Is uneven in the plane, and the intensity of the specular reflection light 206 is increased at each location, and the reflection wavelength is reflected in the plane due to a slight shift in the reflection wavelength due to a shift from the average film thickness to a thin thickness at the uneven portion. Light and shade are formed at the strong and weak portions of the interference light 207, and the color appears to be in-plane.

  As a result of this phenomenon, for example, when the reflected peak wavelength is yellow near 600 nm, a metal-like molded product close to brass that is partially oxidized due to the appearance of vivid gold and dark gold. It becomes. Similarly, when the reflected peak wavelength is around 725 nm, a part that looks bright orange-red and a part that looks dark orange-red are formed, resulting in a metal-like molded product that is close to partially oxidized copper.

  By changing the peak wavelength to be reflected other than the above, a unique metallic film with shades in the surface with a favorite color such as blue, green, red, silver, etc. in addition to yellow and orange red, and molding using it Goods can be obtained.

  It should be noted that the surface of at least one of the base film 103, the release layer 104, the protective layer, or the HC layer 105 may be formed with unevenness.

(Embodiment 2)
FIG. 4A shows an in-mold molding using the insert film 100 having the transfer layer 102 as the laminated film according to the second embodiment of the present invention, and the transfer layer 102 is transferred to the molded resin layer 6 and formed. Item 110 is shown. FIG. 4B shows a partial enlargement in FIG.

  In addition, about the component as FIG. 3 (a) (b), it demonstrates with the same code | symbol.

  The second embodiment is effective when it is desired to emphasize the darkness of the metallic tone that is further deteriorated by oxidation compared to the first embodiment.

  The low refractive index layer 107 in FIG. 4B includes low refractive index nanoparticles 111 and aggregates 112 of low refractive index nanoparticles. The high refractive index layer 108 includes high refractive index nanoparticles 113 and aggregates 114 of high refractive index nanoparticles.

  The low-refractive index layer 107 and the high-refractive index layer 108 according to the second embodiment are formed of the low-refractive index nanoparticle aggregate 112 and the high-refractive index nanoparticle in the low-refractive index layer 107 and the high-refractive index layer 108, respectively. Except for containing the agglomerate 114, the configuration is the same as in the first embodiment. Hollow silica was used for the low refractive index nanoparticles, and zirconia was used for the high refractive index nanoparticles.

  In the low-refractive index layer 107 and the high-refractive index layer 108, the content of nanoparticles contained in each resin layer is preferably higher in the low-refractive index layer. The reason is that the refractive index difference between the refractive index of the resin and the hollow silica of the low refractive index nanoparticles 111 is larger than the refractive index difference between the resin and the high refractive index nanoparticles 113 of zirconia. The difference in refractive index between the low refractive index layer 107 and the high refractive index layer 108 can be effectively increased by adding more hollow silica of the low refractive index nanoparticles 111 to the low refractive index layer 107. Moreover, when the high refractive index layer 108 contains nanoparticles of titanium oxide or zinc oxide having a higher refractive index than that of the zirconia of the high refractive index nanoparticles 113, titanium oxide and zinc oxide have photocatalytic activity that is not found in zirconia. When the amount added to the high refractive index layer 108 is increased, the resin component of the high refractive index layer 108 is subject to photocatalytic activity, and part of the resin layer is oxidized and deteriorated, so that yellowing or the like is likely to occur. Therefore, when the difference in refractive index between the low refractive index layer 107 and the high refractive index layer 108 is increased, it is better to increase the amount of the low refractive index nanoparticles 111 added to the low refractive index layer 107.

  In the second embodiment, when the external light 205 incident from the surface of the molded product 110 reaches the low-refractive index layer 107 and the high-refractive index layer 108, the regular reflection light 206 is reduced at the irregularities at the interface of each layer, and diffuse reflection is performed. In addition to the factors that increase the amount of light 208, the specularly reflected light 206 decreases in the same manner at the locations where the aggregates of nanoparticles in each layer are present, and the diffusely reflected light 208 increases, so that the low refractive index layer 107 and the high refractive index layer 108 are increased. The difference in color density caused by the intensity difference of the reflected light due to the intensity of the interference light due to repetitive reflection at the interface becomes more prominent. The low-refractive index layer 107 and the high-refractive index layer 108 have uneven refractive index in the layer where each layer includes an aggregate of low-refractive index nanoparticles and high-refractive index nanoparticles.

  Since the size of the aggregate is larger than the size of the normal nanoparticle, it is easy to form a convex shape on the film where the aggregate is present, and the in-plane unevenness of the low refractive index layer 107 and the high refractive index layer 108 Will increase. Since irregularities due to aggregates are newly formed in the layers of the low refractive index layer 107 and the high refractive index layer 108, unlike the first embodiment, the amount of irregularities and the depth of the irregularities in the surface even when they are away from the anchor layer 106. And the like, in which the concave and convex portions are formed in the plane up to the end of the low refractive index layer 107 and the high refractive index layer 108. As a result, the regular reflection 206 at the interface of each layer of the low refractive index layer 107 and the high refractive index layer 108 is reduced and the diffuse reflection 208 is increased as compared with the first embodiment, so that the amount and direction of reflected light are more prominent. It becomes non-uniform, and it becomes possible to obtain a metal-like molded product in which the contrast difference of the interference light 207 appearing on the surface of the molded product is further large.

  According to the present invention, for example, it can be widely used to apply a metallic design to resin parts such as exterior casings for home appliances, mobile devices, and interior parts for automobiles by in-mold molding, thermal transfer, and roll transfer.

DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 3 Foil feeder 4 Suction hole 5 Gate 6 Molten resin 7 In-mold molded product 8 Extrusion pin 100 Insert film 101 Carrier layer 102 Transfer layer 103 Base film 104 Release layer 105 Protective layer or hard coat layer 106 Anchor layer 107 Low-refractive index layer 108 High-refractive index layer 109 Concealing layer 110 Metal-molded article 111 of the present invention Low-refractive index nanoparticles 112 Aggregates 113 of low-refractive index nanoparticles High-refractive index nanoparticles 114 High-refractive index nanoparticles Aggregates of

Claims (14)

A plurality of resin layers having different refractive indexes are alternately laminated on a base layer having irregularities on the surface,
The refractive index difference between the alternately laminated resin layers is 0.15 or more,
The resin layers stacked alternately are a low refractive index layer containing low refractive index nanoparticles and a high refractive index layer containing high refractive index nanoparticles, respectively.
The total number of layers of the low refractive index layer and the high refractive index layer is 10 or more, and has at least irregularities at any interface between the low refractive index layer and the high refractive index layer,
Laminated film. A part of the nanoparticles contained in the resin layer constituting the low refractive index layer and the high refractive index layer is an aggregate,
The laminated film according to claim 1. The low refractive index layer and the high refractive index layer each contain nanoparticles having different refractive indexes, and the refractive index difference between the low refractive index layer and the high refractive index layer is 0.15 or more and 0.6 or less. It is characterized by being,
The laminated film according to claim 1 or 2. The average film thickness per layer of each of the low refractive index layer and the high refractive index layer is 50 nm or more and 150 nm or less,
The laminated film according to any one of claims 1 to 3. The thermosetting resin is contained in at least one of the resins constituting the low refractive index layer and the high refractive index layer,
The laminated film according to any one of claims 1 to 4. The peak wavelength of the regular reflectance of the surface is in the visible light region of 400 nm or more and 780 nm or less,
The laminated film according to any one of claims 1 to 5. The unevenness of each layer of the low refractive index layer and the high refractive index layer becomes smaller as the distance from the base layer becomes smaller,
The laminated film according to any one of claims 1 to 6. The content of nanoparticles contained in the low refractive index layer is greater than the content of nanoparticles contained in the high refractive index layer,
The laminated film according to any one of claims 1 to 7. The uneven roughness of the coating surface of the low refractive index layer and the high refractive index layer is Ra, 0.05 or more and 0.5 or less,
The laminated film according to any one of claims 1 to 8. The laminated film according to claim 1 is formed as a transfer layer on a base film through a release layer, and the at least one of the base film, the release layer, the protective layer of the transfer layer, or the hard coat layer has irregularities. Characterized by having,
In-mold film. Filler is contained inside the base film, the base film surface is uneven,
The in-mold film according to claim 10. It has a black masking layer on the surface opposite to the base layer,
The laminated film according to claim 1.   The molded product which transcribe | transferred the laminated | multilayer film of the said Claim 1 on the surface. A plurality of resin layers having different refractive indexes that are alternately laminated in the laminated film according to claim 1 are formed by wet coating.
A method for producing a laminated film.

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