KR20220047539A - Light-shielding film and manufacturing method of light-shielding film - Google Patents

Abstract

In the light-shielding film, the glossiness of at least one surface at an incident angle of 60 degrees is set to a value in the range of 0 or more and 10 or less, the optical density is set to a value in the range of 4 or more, and the total thickness is 6 µm or more and 26 It is set to a value in the range of micrometers or less.

Description

Light-shielding film and manufacturing method of light-shielding film

The present invention relates to a light-shielding film and a method for manufacturing the light-shielding film. Specifically, it is related with the light-shielding film used for uses, such as an optical use, an opto-device use, a display device use, a mechanical component, or an electric/electronic component, and the manufacturing method of a light-shielding film.

The light-shielding film is used, for example, in a camera module, which is an optical component included in an electronic device such as a digital camera or a mobile phone, for the purpose of suppressing the generation and expansion of optical noise in a lens unit. Moreover, in a camera module, a light-shielding film is used also as a gap adjustment member arrange|positioned between optical elements, such as a shutter, a diaphragm member, or a lens.

As the light-shielding film, for example, a black film colored black by adding carbon black to polyethylene terephthalate (PET) and provided with light-shielding properties by forming irregularities on the surface is used. In Patent Document 1, for example, as shown in FIGS. 5 and 6 , light-shielding films 20 and 21 having a structure in which a light-shielding layer 202 is stacked on at least one surface of the film substrate 201 and arranged. This is disclosed. The light-shielding layer 202 consists of a resin which is a curable resin or a thermosetting resin, and black microparticles|fine-particles.

Such light-shielding films 20 and 21 are used as light-shielding films F7 and F8 in the conventional lens unit 30 shown in FIG. 7 . The lens unit 30 shown in this figure is equipped with the sensor lens 33 accommodated in the barrel 32, the infrared cut filter 31, and several lenses L7, L8. The light-shielding films 20 and 21 in Figs. 5 and 6 are formed as light-shielding films F7 and F8 respectively corresponding to the respective lenses L7 and L8 in Fig. 7 . In the lens unit 30, the light-shielding films F7, F8, one or two or more lenses L7, L8, and a CMOS sensor are arranged in this order along the traveling direction of the incident light. By separately forming the light-shielding films F7 and F8 corresponding to each of the lenses L7 and L8, unnecessary light can be sufficiently blocked.

Japanese Patent Publication No. 2010-534342

In recent years, the size reduction, thickness reduction, and weight reduction of a camera module are further calculated|required according to the apparatus to be mounted. Moreover, high functionalization, such as a more extensive zoom function and a high-precision imaging function by fine pixels, is calculated|required of a camera module. It is difficult to achieve such high functionality by digital processing, and it is necessary to improve, for example, the optical zoom function of the lens unit included in the camera module.

However, in order to make the lens unit highly functional, it is necessary to increase the number of lenses, for example. When disposing the light-shielding film corresponding to each lens, the total thickness of the light-shielding film also increases with an increase in the number of lenses. Accordingly, the optical axis direction of the lens unit increases, making it difficult to reduce the size of the lens unit. When the device on which the camera module is mounted is a smart phone, for example, the lens unit protrudes from the casing, which may cause a problem in the design of the device. Such a problem becomes remarkable with the number of sheets of a light-shielding film.

As a countermeasure for such a problem, reducing the thickness of a light-shielding film is considered, for example. However, if the thickness of the light-shielding film is simply reduced, the light-shielding property of the light-shielding film is reduced. Thus, in order to make the miniaturization of a camera module, etc. high functionalization compatible, it is necessary to adjust thickness, maintaining the performance of a light-shielding film.

Then, this invention aims at making thickness reduction possible, maintaining favorable light-shielding property in a light-shielding film.

In order to solve the above problems, in the light-shielding film according to an aspect of the present invention, the glossiness at an incident angle of 60 degrees on at least one surface is set to a value in the range of 0 or more and 10 or less, and a wavelength of 380 nm or more and 780 The optical density in the range of nm or less is set to a value in the range of 4 or more, and the total thickness is set to a value in the range of 6 µm or more and 26 µm or less.

According to the above configuration, since the glossiness of at least one surface of the light-shielding film is set to a value in the range of 0 or more and 10 or less, high light scattering properties (anti-projection properties) for good scattering of incident light to the surface can be imparted. can In addition, since the optical density of the light-shielding film is set to a value in the range of 4 or more and the total thickness is set to a value in the range of 6 µm or more and 26 µm or less, good light-shielding property can be maintained even if the thickness of the light-shielding film is reduced there is.

A film substrate having light-shielding properties, and a scattering layer disposed on top of the film substrate to scatter incident light, the one surface may be a surface of the scattering layer on the opposite side to the film substrate.

Accordingly, for example, even when the thickness of the scattering layer is reduced, the light-shielding effect of the light-shielding film can be satisfactorily maintained by the light-shielding film substrate. Accordingly, it is possible to easily reduce the total thickness of the light-shielding film. Moreover, in the surface on the opposite side to the film base material which has light-shielding property among a scattering layer, favorable light-scattering property can be obtained. In addition, by using a scattering layer separate from the film substrate having light-shielding properties, the degree of freedom in designing the scattering layer can be improved.

The content of the black component in the scattering layer may be set to a value in a range greater than 0% by weight and not more than 4% by weight. In the said light-shielding film, since the film base material has light-shielding property, content of the black component of a scattering layer may be a trace amount. Even with such a structure, the light-shielding property of a light-shielding film can be ensured.

In addition, in the above configuration, the amount of the black component in the scattering layer is suppressed. For this reason, for example, even when the scattering layer is formed using a resin material having ultraviolet curability, the scattering layer can be favorably formed by curing the resin material by irradiating ultraviolet rays. According to this method, compared to the method of forming a scattering layer using a resin material having thermosetting properties, heat does not easily reach the film substrate having light-shielding properties. Therefore, since there is little possibility that the film base material which has light-shielding property will heat-shrink, the thickness of the film base material which has light-shielding property can be reduced. As a result, the total thickness of the light-shielding film can be reduced.

The scattering layer may further include a resin member disposed along the surface of the film substrate, and particles dispersed inside the resin member. According to this structure, the surface of the scattering layer can be provided with a concave-convex shape by the particles. Moreover, the light scattering property inside the scattering layer can be improved. Thereby, light-scattering property can be provided favorably to a scattering layer.

The thickness of the said film base material may be set to the value of the range of 2 micrometers or more and 12 micrometers or less. According to such a structure, the thickness of the film base material which has light-shielding property can be reduced favorably, maintaining the light-shielding property of a light-shielding film by using the film base material which has light-shielding property.

The thickness of the scattering layer may be set to a value in the range of 3 µm or more and 7 µm or less. In the light-shielding film, since the film base material has light-shielding property and the scattering layer does not need to have light-shielding property, the thickness of the scattering layer can be reduced. Therefore, the total thickness of the light-shielding film can be reduced.

The total light transmittance of the scattering layer may be set to a value in the range of 70% or more and 100% or less. By forming the scattering layer in this way, the blackness of the light-shielding film can be favorably obtained by the film substrate having the light-shielding property.

The refractive index of the resin member may be set to a value in the range of 1.3 or more and 1.9 or less. By configuring the scattering layer in this way, it is possible to easily scatter the incident light incident into the scattering layer.

The manufacturing method of the light-shielding film in one aspect|mode of this invention prepares the coating liquid containing the resin material which has ultraviolet curability and electron beam curability, and the film base material which has light-shielding property, A preparation step, and the said film base material a first step of forming a coating film on the surface by applying the coating solution to the surface of the and drying, and irradiating the coating film with ultraviolet rays; By passing through the first step and the second step, from the coating film, a scattering layer whose glossiness at an incident angle of 60 degrees on the surface opposite to the film substrate is set to a value in the range of 0 or more and 10 or less is formed. together with the film substrate and the scattering layer, wherein the optical density in a value in the range of wavelength 380 nm to 780 nm is set to a value in the range 4 or more, and the total thickness is 6 µm or more and 26 µm or less A light-shielding film set to a value in the range is formed.

According to the manufacturing method, when glossiness is set to a value in the range of 0 or more and 10 or less, high light scattering property can be exhibited, and the optical density is set to a value in the range of 4 or more, and the total thickness is 6 µm or more A light-shielding film set to a value in the range of 26 µm or less can be manufactured. Accordingly, it is possible to obtain a light-shielding film capable of maintaining good light-shielding properties despite a relatively small total thickness.

Moreover, by implementing a 2nd step in addition to a 1st step, even when a coating film contains a black component to some extent, for example, a coating film can be hardened favorably. Moreover, heat treatment for hardening the scattering layer is unnecessary. For this reason, there is no thermal contraction of the film base material which has light-shielding property in manufacture of a light-shielding film. Therefore, even if the thickness of the film base material which has light-shielding property is made thin to some extent, shrinkage of a film base material can be prevented. Thereby, the total thickness of a light-shielding film can be reduced.

In the second step, a transfer member having an uneven transfer surface is disposed in the coating film such that the transfer surface is deposited on the surface opposite to the film substrate, and the coating film is irradiated with an electron beam to reduce the unevenness of the coating film. You may form the said scattering layer to which the shape was transcribe|transferred. Accordingly, the shape of the unevenness formed on the transfer surface of the transfer member can be efficiently transferred to the surface of the scattering layer.

In the first step, the coating film is formed on both surfaces of the film substrate, and in the second step, from one side of the film substrate, electron beam is irradiated to the film substrate so as to penetrate the film substrate. You may irradiate an electron beam to a coating film. Thereby, the scattering layer can be simultaneously and efficiently arrange|positioned on both surfaces of the film base material which has light-shielding property.

In the said preparation step, you may prepare the said coating liquid set so that content of the black component of the said scattering layer may become a range larger than 0 weight% and 4 weight% or less. Thereby, the transmittance|permeability of an ultraviolet-ray and an electron beam of a coating film can be maintained. For this reason, a scattering layer can be favorably formed using the said resin material.

In the said preparation step, you may prepare the said coating liquid containing particle|grains further. According to this method, the surface of the scattering layer can be formed in a concave-convex shape with the particles. Moreover, the light scattering property inside the scattering layer can be improved. Accordingly, it is possible to easily impart light scattering properties to the scattering layer.

In the second step, the scattering layer including the resin member whose refractive index is set to a value in the range of 1.3 or more and 1.9 or less may be formed. Accordingly, it is possible to form a scattering layer that easily scatters the incident light.

In the said preparation step, you may prepare the said film base material whose thickness was set to the value of the range of 2 micrometers or more and 12 micrometers or less. According to the said manufacturing method, the thickness of the film base material which has light-shielding property can be reduced favorably, maintaining the light-shielding property of a light-shielding film. Moreover, since a scattering layer is formed by passing through a 1st step and a 2nd step, a heat|fever does not reach a film member easily. For this reason, even when such a thin film substrate having light-shielding properties is used, the film member shrinks due to heating accompanying the formation of the scattering layer, and wrinkles, ripples, curls, etc. occur, making it difficult to process such as punching normally. It can prevent problems from occurring.

In the second step, the scattering layer having a thickness in the range of 3 µm or more and 7 µm or less may be formed from the coating film. In the light-shielding film, since the film base material has light-shielding property and the scattering layer does not need to have light-shielding property, the thickness of the scattering layer can be reduced. Accordingly, it is possible to easily reduce the total thickness of the light-shielding film.

In the second step, a scattering layer having a total light transmittance of 70% or more and 100% or less may be formed from the coating film. By forming the scattering layer in this way, the resin material can be efficiently cured easily by transmitting electron beams through the resin material in the coating solution from the outside.

According to each aspect of this invention, in a light-shielding film, thickness can be reduced, maintaining favorable light-shielding property.

BRIEF DESCRIPTION OF THE DRAWINGS It is an exploded view of the optical component which concerns on 1st Embodiment.
2 is a cross-sectional view of the light-shielding film according to the first embodiment.
Fig. 3(a) is a diagram showing a coating film formation step. (b) is a figure which shows a 1st step. (c) is a cross-sectional view showing the second step.
4 is an enlarged cross-sectional view of a scattering layer of the light-shielding film according to the second embodiment.
5 : is sectional drawing of the conventional light-shielding film.
6 is a cross-sectional view of a conventional light-shielding film.
7 is a partial cross-section of a conventional lens unit.

Hereinafter, each embodiment is demonstrated with reference to drawings.

(First embodiment)

[Light-shielding film]

1 is an exploded view of an optical component 10 according to a first embodiment. As shown in FIG. 1 , the optical component 10 includes a plurality of light-shielding films F1-F6, a plurality of optical members (here, lenses L1-L6), and light-shielding films F1-F6 and an optical member. A casing (barrel) 11 for housing is provided. The light-shielding film 1 is arrange|positioned so that the optical axis R may be enclosed between adjacent optical members as an example. The number of sheets of the light-shielding film with which the optical component 10 is equipped, and the number of objects of an optical member are not limited.

Next, the specific structural example of the light-shielding film 1 is demonstrated. 2 : is sectional drawing of the light-shielding film 1 which concerns on 1st Embodiment. The light-shielding film 1 is the same as that of the light-shielding films F1-F6 of FIG. As shown in FIG. 2 , the light-shielding film 1 of the present embodiment includes a film substrate 2 having light-shielding properties and at least one scattering layer 3 .

The film base material 2 blocks the incident light incident on the light-shielding film 1 . As for the film base material 2, the optical density (OD value) is set to the value of the range of 4 or more. Here, the total light transmittance of the film base material 2 is set to the value of the range of 1 % or less. In order to have light-shielding property, the film base material 2 is opaque as an example, and is black here. The film base material 2 contains a black component and resin as an example. In this embodiment, this black component is a black pigment, and resin is PET. The film base material 2 is formed by extruding and biaxially stretching PET resin containing a black pigment. Moreover, things other than a pigment (for example, dye or a coloring agent) may be sufficient as a black component. The film base material 2 may be colored with colors other than black.

As a material of the film base material 2, various polymeric materials are mentioned, for example. As the said material, a thermosetting resin, a thermoplastic resin, and a photocurable resin are mentioned, for example. Among these, examples of the thermoplastic resin include polyolefin, acrylic resin, polyester, polycarbonate, and polyamide. These materials can be used individually or in combination of 2 or more types. Among them, from the viewpoint of securing strength, for example, cyclic polyolefin, polyalkylene arylate (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polymethyl methacrylate-based resin, bisphenol A-type poly A carbonate, a cellulose ester, etc. are preferable. Moreover, from a viewpoint of dimensional stability and rigidity, the film material by which biaxial stretching was carried out is preferable. As such a film material, a film (eg, PET film, PEN film) made of biaxially stretched polyalkylene arylate is still more preferable. Among these, a PET film is preferable at the point which can make thickness thin and is easy to obtain.

The manufacturing method in particular of the film base material 2 is not restrict|limited. For example, the manufacturing method in which the material which melt-kneaded the black component (as an example, a pigment, dye, or a coloring agent) and the resin component is formed into a film, and is extended|stretched is mentioned. According to the manufacturing method of this aspect, since the film base material 2 which has light-shielding property can be comprised in a single structure without overlapping some material, it is preferable.

Moreover, as a manufacturing method of the film base material 2, the manufacturing method of forming a colored layer in the single side|surface or both surfaces of a resin film (for example, biaxially stretched polyester film) is mentioned. In the case of the manufacturing method of forming this colored layer, you may form a colored layer by apply|coating, transferring, or printing a coloring agent to a resin film. In this case, the coloring agent can be used, for example in a mixed state with the resin material which has fluidity|liquidity.

As a coating method of a coloring agent, well-known methods, such as a gravure coater, a dip coater, a reverse roll coater, and an extrusion coater, can be illustrated. Moreover, as a printing method of a coloring agent, well-known methods, such as an inkjet method and a screen method, can be illustrated. As the colorant to be applied, transferred, or printed to the resin film, it is preferable to use, for example, a sublimable dye from the viewpoint of easiness of penetration into the resin film. Moreover, the pigment|dye which is widely used for a textile use, a resin use, an inkjet use, etc. can also be used.

Moreover, the manufacturing method of immersing a resin film in the solution containing dye in addition to that and dyeing a resin film is mentioned. As a method of dyeing a resin film, a well-known method can be used. In this embodiment, the resin film dyed in this way can also be used as the film base material 2 . A film made of polyester, nylon, acetate, polycarbonate, acrylic, or the like can be easily dyed by immersion in a dye dispersed in water.

Although the thickness of the film base material 2 can be set suitably, it is set to the value of the range of 2 micrometers or more and 12 micrometers or less as an example. As for the film base material 2, the optical density in the range of wavelength 380nm or more and 780 nm or less is set to the value of the range of 4 or more, and it becomes difficult for incident light to permeate|transmit to the inside from the side surface.

The scattering layer 3 is arrange|positioned overlappingly on at least one surface (here both surfaces) of the film base material 2, and scatters incident light. The scattering layer 3 has light transmittance. The scattering layer 3 scatters the incident light which entered the optical member from the side, when it is arrange|positioned overlapping with an optical member, for example. The scattering layer 3 of this embodiment has the resin member 4 arrange|positioned along the surface of the film base material 2, and the black microparticles|fine-particles 5 which are black components disperse|distributed inside the resin member 4 .

The black component of the scattering layer 3 absorbs the incident light incident on the scattering layer 3 . The content of the black component in the scattering layer 3 is set to a value in the range of greater than 0% by weight and not more than 4% by weight here. That is, in the scattering layer 3, the content of the black component is set to a very small amount. Accordingly, the scattering layer 3 has transparency. In the scattering layer 3 of the present embodiment, the total light transmittance is set to a value in the range of 70% or more and 100% or less. In addition, the scattering layer 3 does not need to contain a black component.

Here, the total light transmittance of the scattering layer 3 can be obtained from the difference between the total light transmittance of the light-shielding film 1 and the total light transmittance of the film base material 2 . When the scattering layers 3 are formed on both sides of the film substrate 2, the difference between the total light transmittance of the light-shielding film 1 and the total light transmittance of the film substrate 2 is the difference between the scattering layers 3 on both sides. It corresponds to the sum of all light transmittances. The total light transmittance of the film base material 2 is equal to or higher than the total light transmittance of the light-shielding film 1 and is sufficiently smaller than the total light transmittance of the scattering layer 3 . As an example, the total light transmittance of the light-shielding film 1 is 0, and the total light transmittance of the film base material 2 is equal to or slightly higher than the total light transmittance of the light-shielding film 1 . On the other hand, the total light transmittance of the scattering layer 3 is a value in the range of 70 or more and 100 or less.

Although the thickness of the scattering layer 3 can be set suitably, it is set as a value in the range of 3 micrometers or more and 7 micrometers or less as an example. The thickness of the scattering layer 3 may be smaller than the thickness of the film base material 2 . In the light-shielding film 1, since light-shielding property is ensured by the film base material 2, the thickness of the scattering layer 3 can be reduced. Moreover, the refractive index of the resin member 4 is set to the value of the range of 1.3 or more and 1.9 or less.

The refractive index of the resin member 4 is unique to the material of the resin member 4, and can be confirmed by analyzing the resin member 4 using analyzers, such as NMR and IR, for example. In other words, the resin member 4 of the scattering layer 3 can be specified by measuring the scattering layer 3 with an analyzer such as NMR or IR. The value of the refractive index of the resin member 4 may be either a literature value or an actual value. Moreover, when the total light transmittance of the scattering layer 3 is sufficiently high, an Abbe refractometer conforming to JIS K 7142: 2008 or an elliptically polarization measuring device (for example, "KOBRA-WPR" manufactured by Oji Instruments Co., Ltd.) By directly measuring the Abbe's number of the scattering layer 3 by the measurement using

Here, in the light-shielding film 1, the glossiness of at least one surface (here, both surfaces) of the scattering layer 3 at an incident angle of 60 degrees is set to a value in the range of 0 or more and 10 or less, and the wavelength is 380 nm or more and 780 The optical density in the range of nm or less is set to a value in the range of 4 or more, and the total thickness is set to a value in the range of 6 µm or more and 26 µm or less.

In this way, when the surface 3a of the scattering layer 3 is set, the surface 3a has light scattering properties. The shape of the surface 3a of the scattering layer 3 is formed by transferring the unevenness of the transfer surface 8a of the transfer member 8, as an example, in the production of the light-shielding film 1, as will be described later. has been In addition, the shape of the surface 3a of the scattering layer 3 may be formed by other methods. Moreover, the adhesive layer for improving the adhesiveness of the film base material 2 and the scattering layer 3 may be formed on the surface of the film base material 2 opposing to the scattering layer 3 .

The resin member 4 contains the binder resin 6 and the polymerization initiator of the precursor of the binder resin 6 . The precursor of the binder resin 6 has ultraviolet (UV) curability and electron beam (EB) curability. As the binder resin 6, photocurable resin is mentioned, for example.

Examples of the black component contained in the film substrate 2 and the scattering layer 3 include carbon black, lamp black, vine black, pitch black, bone charcoal, carbon nanotubes, silver oxide, zinc oxide, magnetite-type triiron tetraoxide. , a complex oxide of copper and chromium, a complex oxide of copper, chromium, and zinc, and black glass.

The black microparticles|fine-particles 5 of this embodiment are spherical, and the primary particle diameter is set to the value of the range of 10 nm or more and 500 nm or less. In addition, the surface resistance value of the scattering layer 3 is set to a value of 1×10 ¹² Ω/□ or more as an example. By performing such setting, the light-shielding film 1 can be suitably used as an insulating member.

In addition, the glossiness in 60 degree|times can be measured by the measuring method based on JISZ8741. For the primary particle size, a photograph of the particle surface magnified by 100,000 times with a field emission scanning electron microscope ("JSM-6700F" manufactured by Nippon Electronics Co., Ltd.) is taken, and the enlarged photograph is further enlarged as necessary, 50 For more than one particle, it can measure as the average particle diameter of the number using a ruler, a nonius, etc.

In addition, as for the optical density, using an optical densitometer ("X-Rite 341C" manufactured by Videojet X-Rite Co., Ltd.), the sample is irradiated with a beam of perpendicularly transmitted light, and the ratio with the state without the sample is log (logarithmic). It can be shown as The beam width in this case can be measured as a circular shape with a diameter of 2 mm.

As described above, in the present embodiment, since the glossiness of at least one surface of the light-shielding film 1 is set to a value in the range of 0 or more and 10 or less, high light scattering property to favorably scatter incident light on the surface. (Projection prevention property) can be provided. In addition, since the optical density of the light-shielding film 1 is set to a value in the range of 4 or more, and the total thickness is set to a value in the range of 6 µm or more and 26 µm or less, even if the thickness of the light-shielding film 1 is reduced Good light-shielding properties can be maintained.

Moreover, since the total thickness of the sum total of the some light-shielding film 1 can be reduced by this, the casing 11 is a some optical member (lens L1-L6) and some light-shielding film (F1-L6). Even in the case of accommodating F6), the dimension of the casing 11 in the optical axis R direction can be reduced. Thereby, the dimension of the optical axis R direction of the optical component 10 provided with the casing 11 can be reduced. Accordingly, it is possible to easily achieve a reduction in thickness and size of the optical component 10 . In addition, by reducing the size of the casing 11 , it is suppressed that, among the surfaces of the optical component 10 , the area overlapping the casing 11 protrudes to the outside compared to the peripheral area of the area, and the surface of the optical component 10 . It can also be made easy to achieve the flattening of.

Moreover, the light-shielding film 1 of this embodiment is provided with the film base material 2, and the scattering layer 3 which is arrange|positioned superimposed on the film base material 2, and scatters incident light, and the glossiness is set to the said value. The one surface is the surface 3a of the scattering layer 3 on the opposite side to the film substrate 2 .

Accordingly, for example, even if the thickness of the scattering layer 3 is reduced, the light-shielding effect of the light-shielding film 1 can be maintained by the film substrate 2 . Accordingly, the total thickness of the light-shielding film 1 can be easily reduced. Moreover, in the surface 3a of the scattering layer 3 on the opposite side to the film base material 2, favorable light-scattering property can be acquired. Moreover, by using the scattering layer 3 separate from the film base material 2, the degree of freedom in designing the scattering layer 3 can be improved.

Moreover, the scattering layer 3 of this embodiment has light transmittance. Accordingly, when the scattering layer 3 is constituted by using, for example, a resin material having ultraviolet curability or electron beam curability, it is possible to suppress blocking of ultraviolet rays and electron beams by components present in the resin material. Accordingly, the scattering layer 3 can be favorably configured. Further, since it is not necessary to use a resin material having thermosetting properties as the material for the scattering layer 3, for example, even on a thin film, the scattering layer 3 can be obtained by irradiating the resin material with ultraviolet rays or electron beams.

In addition, in the scattering layer 3 of the present embodiment, the content of the black component is set to a value in the range of greater than 0% by weight and not more than 4% by weight. In the light-shielding film 1, since the film base material 2 has light-shielding property, content of the black component of the scattering layer 3 may be trace amount. Even with such a structure, the light-shielding property of the light-shielding film 1 can be ensured.

Moreover, the thickness of the film base material 2 is set to the value of the range of 2 micrometers or more and 12 micrometers or less. According to such a structure, the thickness of the film base material 2 can be reduced favorably, maintaining the light-shielding property of the light-shielding film 1 by using the film base material 2 according to such a structure. Moreover, in the light-shielding film 1, since it is not necessary to form the scattering layer 3 by thermal curing, even if the thickness of the film base material 2 is made thin in this way, the heat shrinkage of the film base material 2 is not necessary. It is possible to prevent the occurrence of the resulting problems.

Further, the scattering layer 3 is not required to have light-shielding properties. For this reason, the thickness of the scattering layer 3 of this embodiment is set to a value in the range of 3 micrometers or more and 7 micrometers or less. In the light-shielding film 1, since the film base material 2 has light-shielding property and the scattering layer 3 does not need to have light-shielding property, the thickness of the scattering layer 3 can be reduced. Therefore, the total thickness of the light-shielding film 1 can be reduced.

Further, the scattering layer 3 has a total light transmittance of 70% or more and 100% or less. By forming the scattering layer 3 in this way, the blackness of the light-shielding film 1 can be favorably obtained with the film base material 2 . Such a scattering layer 3 can be constituted, for example, by UV curing or electron beam curing of a resin material. Moreover, the refractive index of the scattering layer 3 is set to a value in the range of 1.3 or more and 1.9 or less. Accordingly, it is possible to easily scatter the incident light incident on the scattering layer 3 .

[Method for producing light-shielding film]

Next, the manufacturing method of the light-shielding film 1 is illustrated. 3 : is a manufacturing flowchart of the light-shielding film 1 of FIG. Fig. 3(a) is a diagram showing the first step S2. Fig. 3(b) is a diagram showing the first step S2. Fig. 3(c) is a diagram showing the second step S3.

The light-shielding film (1) manufacturing method of this embodiment has preparation step S1, 1st step S2, 2nd step S3, and peeling step S4. The light-shielding film 1 is manufactured by performing steps S1-S4 in order. Hereinafter, steps S1 to S4 will be specifically described.

In preparation step S1, an operator prepares the coating liquid used as the base of the scattering layer 3, and the film base material 2. Specifically, the operator dissolves a resin material having ultraviolet curability and electron beam curability in a solvent. Then, the operator adds a black component (black microparticles|fine-particles 5 in this embodiment) to this solvent as an example. Thereby, a coating liquid is obtained.

Here, the operator adjusts the coating liquid so that the solid content concentration is greater than 5% by weight and is 50% by weight or less (here, 30% by weight as an example). In this embodiment, since it is necessary to harden the resin material which has ultraviolet curability and electron beam curability, the polymerization initiator of the said resin material is further added to a coating liquid. In addition, when not using the resin material which has ultraviolet curability, of course, the said polymerization initiator is unnecessary.

Moreover, an operator prepares the film base material 2 which has light-shielding property manufactured by the manufacturing method mentioned above. The operator sets the film base material 2 to a predetermined coater. With the above, preparation step S1 is completed.

Next, the operator performs 1st step S2 in the following procedure. 1st step S2 is a step of forming the coating film 15 on the said surface by apply|coating the said adjusted coating liquid to the surface of the film base material 2, and drying it, and then irradiating an ultraviolet-ray to the coating film 15. . As an example, 1st step S2 contains a coating-film formation step, a transfer step, and an ultraviolet irradiation step as a substep.

Specifically, an operator applies a coating liquid to the at least one surface of the film base material 2 . In this embodiment, in order to form the coating film 15 on both surfaces of the film base material 2 as an example, a coating liquid is apply|coated to each surface of the film base material 2 . You may apply a coating liquid to each surface of the film base material 2 one by one.

Then, the operator forms the coating film 15 on both surfaces of the film base material 2 by drying the coating liquid applied to each surface of the film base material 2 with wind (hot air here) (FIG. 3 ( a)). As described above, the coating film forming step is completed. In addition, the surface is smooth and the coating film 15 of this embodiment is not hardened|cured completely at the time point immediately after formation.

Next, the operator, using the transfer member 8 having the predetermined transfer surface 8a, applies the surface shape of the transfer surface 8a of the transfer member 8 to the surface of the coating film 15 in the following procedure. A transfer step for transferring is performed. The transfer surface 8a of the transfer member 8 has a negative shape corresponding to this positive shape when the surface shape formed in the coating film 15 is made into a positive shape. In the present embodiment, as the transfer member 8, a film member having ultraviolet transmittance and electron beam transmittance is used.

The operator bonds the transfer member 8 to the coating film 15 formed on the at least one surface of the film base material 2 . Thereby, a composite (hereinafter, referred to as an intermediate body 16) in which the transfer member 8 is bonded to each coating film 15 of the film substrate 2 is formed. In the intermediate body 16 , the surface shape of the transfer surface 8a of the transfer member 8 acts as a negative type, and the positive type surface shape is transferred to the coating film 15 . With the above, the transfer step is completed.

Next, the operator performs 1st step S2 which irradiates an ultraviolet-ray to the intermediate body 16 in the following procedure. (Fig. 3(b)). Thereby, in the state which the transfer member 8 was bonded together, the surface which contact|connects the transfer surface 8a of the coating film 15 is hardened to some extent.

The transfer surface 8a of the transfer member 8 having a negative shape is formed with fine irregularities. The scattering layer 3 is imparted with light scattering properties by transferring the fine irregularities. In the present embodiment, since a film member having ultraviolet transmittance and electron beam transmittance is used as the transfer member 8 , a part of the resin material in the coating film 15 is cured by ultraviolet light through the transfer member 8 . . As described above, the first step S2 is completed. After 1st step S2, the obtained intermediate body 16 is wound up in roll shape.

Here, the transfer member 8 of this embodiment is demonstrated. The transfer member 8 contains a plurality of resin components. The transfer surface 8a has a fine concavo-convex shape in the shape of a sea island having a phase-separated structure. The light scattering property imparted to the surface 3a of the scattering layer 3 to the surface 3a of the scattering layer 3 depends on the shape of the transfer surface 8a of the transfer member 8 . Incidentally, the phase-separated structure is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase of the adjustment liquid serving as the base of the transfer member 8 . For details of the phase separation structure, for example, Japanese Patent Publication No. 6190581 may be referred to.

In addition, in this embodiment, as for the intermediate body 16 after 1st step S2 and before 2nd step S3, the coating film 15 is not completely hardened|cured. The coating film 15 has the non-hardened part unevenly distributed on the film base material 2 side, for example. In order to obtain the light-shielding film 1, it is necessary to completely harden this coating film 15. Moreover, in another embodiment, the coating film 15 may harden|cure completely only by the ultraviolet irradiation step of 1st step S2. In this case, the following second step S3 can be omitted.

Next, the operator unwinds the wound intermediate body 16 again, and performs 2nd step S3 which irradiates an electron beam to the coating film 15 which irradiated the ultraviolet-ray in 1st step S2. Thereby, the resin material in the coating film 15 is completely hardened, and the surface shape of the scattering layer 3 is formed.

According to 2nd step S3, the adhesive strength of the film base material 2 and the scattering layer 3 can be improved. For this reason, 2nd step S3 is suitable when manufacturing the light-shielding film 1 provided with the film base material 2 and the scattering layer 3 like this embodiment. In 2nd step S3, an electron beam may be irradiated with respect to the intermediate body 16 only from a single side|surface side, and an electron beam may be irradiated from both sides.

In addition, for example, in the case where the adhesive strength of the film base material 2 and the scattering layer 3 is sufficient, the irradiation intensity of an electron beam may be weakened, or 2nd step S3 may be abbreviate|omitted. That is, 2nd step S3 can be suitably set or abbreviate|omitted according to the adhesive strength of each member calculated|required in the light-shielding film 1, etc.

Moreover, in 2nd step S3, it is not necessary to use an electron beam. For example, when performing 2nd step S3 in the state in which the transfer member 8 is not arrange|positioned on the coating film 15, it is also possible to use an ultraviolet-ray in 2nd step S3. In the state where the transfer member 8 is arrange|positioned on the coating film 15, it is preferable to use an electron beam in 2nd step S3.

Moreover, it is not necessary to wind up the intermediate body 16 between 1st step S2 and 2nd step S3. For example, according to the embodiment, without winding up the intermediate body 16, you may implement 1st step S2 and 2nd step S3 continuously.

Next, the operator performs peeling step S4 of peeling the transfer member 8 from the intermediate body 16 . When the transfer member 8 is arrange|positioned on both surfaces of the film base material 2 like this embodiment, each transfer member 8 may be peeled simultaneously, and you may peel in order from either one. As mentioned above, the light-shielding film 1 is obtained by passing through peeling step S4.

According to the manufacturing method, high light scattering property can be exhibited by setting the glossiness in the surface incident angle of 60 degrees to a value in the range of 0 or more and 10 or less, and the optical density is set to a value in the range of 4 or more and a total thickness of 6 µm or more and 26 µm or less, the light-shielding film 1 can be manufactured. Therefore, the light-shielding film 1 which can maintain high light-shielding property even if the total thickness is thin can be obtained.

Moreover, by implementing 2nd step S3 in addition to 1st step S2, even when the coating film 15 contains a black component to some extent, the coating film 15 can be hardened favorably. Moreover, the heat treatment for hardening the scattering layer 3 is unnecessary. For this reason, there is no thermal contraction of the film base material 2 in manufacture of the light-shielding film 1 . Therefore, even if it makes the thickness of the film base material 2 thin to some extent, shrinkage of the film base material 2 can be prevented. Thereby, the total thickness of the light-shielding film 1 can be reduced.

Moreover, in 2nd step S3 of this embodiment, the transfer surface 8a is adhered to the surface on the opposite side to the film base material 2 among the coating film 15 of the transfer member 8 which has the transfer surface 8a in which the unevenness|corrugation was formed. By irradiating the coating film 15 with an electron beam in the state arrange|positioned so that it may be so, the scattering layer 3 in which the shape of the unevenness|corrugation was transcribed is formed. Accordingly, the shape of the unevenness formed on the transfer surface 8a of the transfer member 8 can be efficiently transferred to the surface 3a of the scattering layer 3 . Moreover, even if the coating film 15 does not contain particle|grains, such as silica microparticles|fine-particles, light-scattering property can be provided to the scattering layer 3 .

Moreover, in 1st step S2 of this embodiment, the coating film 15 is formed on both surfaces of the film base material 2, In 2nd step S3, from the single side|surface side of the film base material 2, the film base material 2 An electron beam is irradiated to each coating film 15 by irradiating an electron beam so that it may pass. Thereby, the scattering layer 3 can be simultaneously and efficiently arrange|positioned on both surfaces of the film base material 2.

Moreover, in preparation step S1 of this embodiment, the coating liquid set so that content of the black component of the scattering layer 3 may become larger than 0 weight% and the range of 4 weight% or less is prepared. Thereby, it can prevent favorably that the transmittance|permeability of the ultraviolet-ray and electron beam with respect to a coating liquid falls by a black component, and can form the scattering layer 3 efficiently from a coating liquid.

Moreover, in preparation step S1, as an example, thickness prepares the film base material 2 set to the value of the range of 2 micrometers or more and 12 micrometers or less. Thereby, maintaining the light-shielding property of the light-shielding film 1, the thickness of the film base material 2 can be reduced favorably. Moreover, since the scattering layer 3 is formed by going through 1st step S2 and 2nd step S3, a heat|fever does not apply to the film base material 2 easily. For this reason, even when the thin film base material 2 is used in this way, the film base material 2 shrinks by heating accompanying the formation of the scattering layer 3, and wrinkles, ripples, curls, etc. are generated, resulting in normal punching, etc. It is possible to prevent the occurrence of a problem that makes processing difficult.

Moreover, in 2nd step S3, the scattering layer 3 set to the value in the range of 3 micrometers or more and 7 micrometers or less in thickness is formed from the coating film 15 as an example. In the light-shielding film 1, since the film base material 2 has light-shielding property and the scattering layer 3 does not need to have light-shielding property, the thickness of the scattering layer 3 can be reduced. Accordingly, the total thickness of the light-shielding film 1 can be easily reduced.

Moreover, in 2nd step S3, the scattering layer 3 set to the value of the range of 70 % or more and 100 % or less is formed from the coating film 15 as an example. By forming the scattering layer 3 in this way, the resin material can be efficiently cured easily by transmitting an electron beam through the resin material in the coating solution from the outside.

In the second step S3, as an example, the scattering layer 3 whose refractive index is set to a value in the range of 1.3 or more and 1.9 or less is formed. Thereby, the scattering layer 3 which easily scatters the incident light can be formed. Hereinafter, other embodiment is demonstrated centering on the difference from 1st Embodiment.

(Second embodiment)

4 is an enlarged cross-sectional view of the scattering layer 103 of the light-shielding film 101 according to the second embodiment. The scattering layer 103 is arrange|positioned overlappingly on at least one surface (here both surfaces) of the film base material 2, and scatters incident light. The scattering layer 103 has a resin member 4 disposed along the surface of the film substrate 2 , and particles 7 dispersed inside the resin member 4 .

The content of the black component in the scattering layer 103 is set to a value in the range of greater than 0% by weight and greater than or equal to 4% by weight. The scattering layer 103 of this embodiment contains a black component (black fine particles 5 as an example) here. This black component is disperse|distributed inside the resin member 4 . The particle|grains 7 may be either inorganic particles, such as a silica particle, or organic particles, such as an acryl particle. When the particle 7 is an inorganic particle, as the particle 7, a silica particle is preferable, for example, and a hollow silica particle is especially preferable.

As for the scattering layer 103, the unevenness|corrugation is formed in the surface 103a of the particle|grains 7. As shown in FIG. Accordingly, the surface 103a of the scattering layer 103 has the same shape as the surface 3a of the scattering layer 3 . In addition, as long as the scattering layer 103 contains the particle|grains 7 to the extent that unevenness|corrugation is formed on the surface 103a, it is not necessary to contain a black component.

As described above, according to the scattering layer 103 , the surface of the scattering layer 103 can be provided with an uneven shape by the particles 7 . Accordingly, the light scattering property can be favorably provided to the scattering layer 103 . Moreover, when the black component is contained in the said weight range in the resin member 4, by dispersing the black component in the resin member 4, the resin member 4 can be appropriately colored black.

At the time of manufacture of the light-shielding film 101 of 2nd Embodiment, the coating liquid similar to 1st Embodiment is prepared except containing the particle|grains 7 of a predetermined amount. After forming the coating film 15 on the surface of the film base material 2 using this coating liquid, 1st step S2 and 2nd step S3 are sequentially performed with respect to the coating film 15.

Here, in the second embodiment, the transfer step is unnecessary in the first step S2. In 2nd Embodiment, the surface of the coating film 15 turns into an uneven|corrugated shape immediately after a coating-film formation step. For this reason, the surface of the scattering layer 3 can be formed in the uneven|corrugated shape with the particle|grains 7 without going through a transfer step (without using the transfer member 8). Thereby, light-scattering property can be provided to the surface of the coating film 15.

In the second embodiment, the scattering layer 103 is formed by sequentially performing the ultraviolet irradiation step and the second step S3. In addition, in 2nd Embodiment also, you may provide unevenness|corrugation to the surface of the coating film 15 by the transfer surface 8a of the transfer member 8 by implementing a transcription|transfer step further.

The light-shielding film 101 has a total thickness, an optical density in a range of a wavelength of 380 nm to 780 nm, a lightness specified in JIS Z 8518, blackness (L ^* ), and a scattering layer 103 . The glossiness of the surface 103a of is set to be the same as that of the light-shielding film 1 of the first embodiment.

Here, L ^※ is one of the coordinate axes of the CIE1976 (L ^※ , a ^※ , b ^※ ) color space. The value of L ^* represents the brightness (brightness) of a color, and is expressed in 100 steps from 0 to 100. In this 100 step, 0 is black and 100 is white. The larger the value of L ^* , the brighter the color.

The light-shielding film 101, as an example, has a total thickness of 16 µm, an optical density of 6.3 in a range of wavelengths of 380 nm to 780 nm, a blackness (L ^* ) of 17.5, and a scattering layer (103). ), the glossiness of the surface 103a at an incident angle of 60 degrees is set to 0.2.

Also in the light-shielding film 101 provided with the above-mentioned scattering layer 103, the effect similar to the light-shielding film 1 is exhibited. Moreover, the scattering layer 103 of the light-shielding film 101 has the resin member 4 and the particle|grains 7 . For this reason, the uneven|corrugated shape can be provided to the surface 103a of the scattering layer 103 by the particle|grains 7. As shown in FIG. Moreover, the light scattering property inside the scattering layer 103 can be improved. Thereby, light scattering property can be provided favorably to the scattering layer 103. Moreover, when the black microparticles|fine-particles 5 are disperse|distributed in the resin member 4 in the said weight range, the resin member 4 can be colored black suitably.

Moreover, in the light-shielding film 101, the amount of the black component of the scattering layer 103 is suppressed. For this reason, when comprising the resin member 4 using the resin material which has ultraviolet curability and electron beam curability, for example, it can suppress that an ultraviolet-ray and an electron beam are shielded by a black component. Therefore, the said resin material can be hardened|cured favorably. Accordingly, at least the amount of the resin material used can cure the resin material, and the thickness of the scattering layer 103 can be easily reduced.

(confirmation test)

Next, although the confirmation test is demonstrated, this invention is not limited to each Example shown below.

[Test 1]

In the following procedure, as shown in Table 1, Examples 1 and 2 which are the light-shielding film 1 which concern on 1st Embodiment, and Example 3 which is the light-shielding film 101 which concerns on 2nd Embodiment are manufactured did Moreover, Comparative Examples 1-3 were manufactured as comparative examples with respect to Examples 1-3.

(Preparation of the film base material)

The film base material (2) of Examples 1-3 was manufactured in the following procedure. A CB masterbatch was prepared by melt-kneading 95% by weight of polyethylene terephthalate and 5% by weight of carbon black (CB-1) produced by a furnace method having an average primary particle size of 18 nm in a vented 280°C extruder. . Moreover, the SiO2 masterbatch was manufactured by melt _- kneading 98.0 weight% of polyethylene terephthalate and 2.0 weight% of silica particles with an average primary particle diameter of 2.6 micrometers within the vented 280 degreeC extruder.

Next, the film raw material was obtained by mixing 13 weight% of CB masterbatch manufactured as mentioned above, 1.5 weight% _of SiO2 masterbatch, and PET 85.5 weight%. This film raw material was extruded into a sheet form from a T-shaped nozzle, and was wound around a mirror cooling drum having a surface temperature of 20°C based on an electrostatic application casting method to obtain a film intermediate having a thickness of 55 µm.

The film intermediate body obtained as mentioned above was sequentially biaxially stretched as follows using the biaxial stretching test apparatus ("FILM STRETCHING TESTER" manufactured by Toyo Seiki Seisakusho Co., Ltd.). First, the film intermediate body was heated at 90 degreeC, and it extended|stretched 2.8 times in the length (extrusion) direction. Next, after cooling a film intermediate body, it heated at 130 degreeC and extended|stretched 3.3 times in the transverse direction (film width direction). Then, the 6-micrometer-thick film base material (2) of Examples 1-3 was obtained by heat-processing a film intermediate body at 180 degreeC.

Moreover, the film base material of Comparative Examples 1-3 was prepared as follows. Comparative Examples 1 and 3 of 6 µm-thick transparent PET films in the same manner as in Examples 1 to 3 except that the SiO ₂ masterbatch was set to 1.7 wt% and PET was set to 98.3 wt% to obtain a film raw material. was prepared as a film substrate of Moreover, the Toyobo Co., Ltd. product "Toyobo ester film E5100#12" which is a commercially available 12-micrometer-thick transparent PET film was used as the film base material of the comparative example 2.

(Preparation for the absence of transcription)

As the transfer members 8 of Examples 1 and 2, transfer members A and B having the following specifications were prepared. As a transfer member A, a transfer surface having a thickness of 50 µm, an arithmetic mean height Sa of surface roughness of 0.666 µm, a maximum height of surface roughness Sz of 6.177 µm, a total haze of 77.44, and a glossiness at an incident angle of 60 degrees set to 3.3 ( 8a) was prepared. This transfer member A was used for manufacture of Example 1.

As the transfer member B, a transfer surface having a thickness of 50 µm, an arithmetic mean height Sa of surface roughness of 1.156 µm, a maximum height of surface roughness Sz of 12.483 µm, a total haze of 91.85, and a glossiness at an incident angle of 60 degrees set to 1.3 ( 8a) was prepared. This transfer member B was used for manufacture of Example 2. Both of the transfer members A and B consist of a film member containing a plurality of resin components and having a phase-separation structure of the plurality of resin components.

(Adjustment of the scattering layer)

The coating liquid used for Examples 1 and 2 was prepared as follows. 15% by weight of a black pigment (“MHI Black #273” manufactured by Mikuni Dyes Co., Ltd., which is a 9% by weight MEK dispersion of carbon black (black fine particles) having an average primary particle size of 150 nm), and Resin A (Yokohama Rubber, a composition containing an acrylate) Co., Ltd. product "HR370") 77 weight%, resin B (Nippon Synthetic Chemical Co., Ltd. product "purple light UV1700B") 8 weight% of resin B which is a polyfunctional methacrylate compound, respectively, the coating liquid containing 8 weight% of solid content ratio was prepared . Carbon black which is a black pigment is contained in this coating liquid at a solid content concentration of 1.08 weight%. By using this coating solution, in the scattering layers 3 of Examples 1 and 2, the solid content concentration of carbon black, which is a black pigment, is set to 4 wt%, and the maximum thickness is set to 4.5 µm.

Moreover, the coating liquid used for Example 3 was prepared as follows. Mikuni Color Co., Ltd. "MHI Black #273" 10% by weight, Resin A 33% by weight, Resin B 4% by weight, and Fuji Silicia Chemical Co., Ltd. particle "Silysia 448" 53% by weight each in a solid content ratio The coating liquid containing was prepared. By using this coating solution, in the scattering layer 103 of Example 3, the solid content concentration of carbon black, which is a black pigment, is set to 4 wt%, and each thickness is set to 3.0 µm.

Moreover, the coating liquid used for Comparative Examples 1 and 2 was prepared as follows. The coating liquid which contains 64 weight% of Mikuni Dyes Co., Ltd. product "MHI black #273", 27 weight% of resin A, and 9 weight% of resin B at a solid content ratio, respectively was prepared. Moreover, the coating liquid used for the comparative example 3 was prepared as follows. 37 wt% of “MHI Black #273” manufactured by Mikuni Color Co., Ltd., 16% by weight of Resin A, 5% by weight of Resin B, and 42% by weight of filler particles “Silysia 448” manufactured by Fuji Silicia Chemical Co., Ltd. A coating solution containing By using these coating solutions, in the scattering layers of Comparative Examples 1-3, the solid content concentration of carbon black which is a black pigment is set to 20 weight%.

Next, about Examples 1 and 2, 1st step S2 and 1st step S2 were implemented in the following order. Using each coating solution, a coating film 15 is formed on one surface of the film base material 2, and in a state in which the transfer member 8 is superposed on the coating film 15, the transfer member 8 is The coating film 15 was interposed and irradiated with ultraviolet rays having an accumulated light amount of 100 mJ/cm 2 . Thereafter, in the same manner as above, the coating film 15 is formed on the other surface of the film substrate 2, and in a state in which the transfer member 8 is superposed on the coating film 15, the transfer member 8 is In the intervening manner, the coating film 15 was irradiated with ultraviolet rays. Then, the intermediate body (16) was wound up.

Next, the wound intermediate 16 was unwound again, and in the second step S3, each coating film 15 was irradiated with an electron beam having an accumulated electron dose (absorbed dose) of 250 kGy at a time. Then, in peeling step S4, the transfer member 8 was peeled from each coating film 15, and the light-shielding film 1 of Examples 1 and 2 was obtained. Moreover, the light-shielding film of Example 3 was used by the manufacturing method of Examples 1 and 2 and the manufacturing method of the same method except having abbreviate|omitted the transfer step in a 1st step using the coating liquid of Example 3 (101) was obtained.

In addition, using the film substrate (transparent film substrate) and the coating solution of Comparative Examples 1 to 3, the transparent film substrate and the scattering layer overlapped on both surfaces of the transparent film substrate (as shown in Table 2, 20 wt% of Comparative Examples 1 to 3 were prepared. The maximum thickness of each scattering layer in Comparative Examples 1 and 2 was set to 9.5 µm, and the maximum thickness of each scattering layer in Comparative Example 3 was set to 10.0 µm.

The scattering layer provided in the light-shielding film of Comparative Examples 1 to 3 corresponds to the scattering layer 3 provided in Examples 1 to 3, but since the content of black fine particles is large and has light-shielding properties, any It is different from the scattering layer 3 which has a degree of light transmittance. As for the scattering layers of Comparative Examples 1 and 2, the shape of the surface is formed by containing filler particles. Moreover, the scattering layer of Comparative Example 3 has a surface shape formed by the transfer surface of the transfer member.

For each light-shielding film of Examples 1-3 and Comparative Examples 1-3, the total thickness of the light-shielding film, the total light transmittance of the film substrate, the thickness of the film substrate, optical density (OD value), blackness (L ^* ) , and glossiness at an incident angle of 60 degrees were measured.

Based on JISK7136, the total light transmittance (%) of a film base material was measured using the hazemeter (Nippon Denshoku Co., Ltd. product, NDH-5000W). The optical density (OD value) was measured using a transmission densitometer (type 341C manufactured by Xrite Co., Ltd.) in accordance with JIS-K7361.

The glossiness at an incident angle of 60 degrees was measured using the glossmeter (KT-GL0030 type|mold by the TQC Serminport Quality Control company) based on JIS K7105. Black rice (L ^* ) was measured using a UV spectrophotometer (U3900H type manufactured by Hitachi Corporation).

In addition, the total haze of the transcription|transfer members A and B was measured using HAZEMETER (Nippon Denshoku Co., Ltd. product NDH5000W type|mold). The arithmetic mean height Sa and maximum height Sz of surface roughness were measured using the scanning white interference microscope (For example, Ryoka Systems Co., Ltd. product, VertScan R3300G type). The measurement results are shown in Tables 1 and 2.

As shown in Tables 1 and 2, both Examples 1-3 obtained favorable results compared with Comparative Examples 1-3. It was confirmed that Examples 1-3 had the optical density (OD value) and blackness substantially the same as Comparative Examples 1-3, and that the total thickness was small compared with Comparative Examples 1-3.

Here, in Comparative Examples 1 to 3, it is necessary to ensure light-shielding property by the scattering layer, and while containing a relatively large amount of black component, in order to maintain the hardness of the surface of the scattering layer at a certain level or higher, the content of the binder resin is also need to increase For this reason, it is considered that the maximum thickness of the scattering layer is increased and the total thickness of the light-shielding film is also increased.

On the other hand, in Examples 1-3, by using the film base material 2, there is no problem regarding the content of such a black component and binder resin, and the maximum thickness of the scattering layer 3 can be reduced. Thereby, the total thickness of the light-shielding film 1 of Examples 1-3 is reduced favorably. As a result, in Examples 1-3, it is thought that the total thickness of the light-shielding film 1 was able to be reduced, ensuring favorable light-shielding property.

Moreover, it was confirmed that Examples 1-3 had the low glossiness (60 degree|times) compared with Comparative Examples 1-3 (particularly Comparative Example 1), and had the outstanding light-scattering property. Moreover, it was confirmed that the glossiness of Example 2 was significantly lower also compared with Example 1.

One of the reasons for obtaining such a result is that the shape of the surface 3a of the scattering layer 3 is formed by the transfer surface 8a of the transfer member 8, and the glossiness of the surface 3a ( 60 degrees) is considered to have been able to be sufficiently reduced. The superiority with respect to Comparative Examples 1-3 of Examples 1-3 was confirmed by the above.

[Test 2]

Next, the light-shielding films of Comparative Examples 4-9 shown to the following Tables 3 and 4 were prepared, and the measurement result was compared with the measurement result of Examples 1-3. Comparative Examples 4 to 9 were prepared under the same conditions as in Example 1 except for the differences shown below.

Comparative Example 4 having the same configuration as in Example 1 was prepared except that a transparent (ie, not having light-shielding property) film substrate was used. In addition, Comparative Example 5 having the same configuration as Comparative Example 4 was prepared except that the content of the black component in the scattering layer was set to 20% by weight and the resin curing method of the scattering layer was only UV curing.

In addition, the content of the black component of the scattering layer is set to 20% by weight, the total light transmittance is set to a value in the range of 70% or more and 100% or less, and when the light-shielding film is manufactured, each coating film serving as the base of the light-shielding layer is irradiated. Comparative Example 6 having the same configuration as Comparative Example 4 was prepared except that the accumulated electron dose of the electron beam was set to 250 kGy.

In addition, Comparative Example 7 having the same configuration as Comparative Example 4 was prepared except that the content of the black component in the scattering layer was set to 20 wt% and the maximum thickness of each scattering layer was set to 10.0 µm. Comparative Example 8 having the same configuration as Comparative Example 4 except that the maximum thickness of each scattering layer was set to 8.0 µm, a thermosetting resin was used as the material of the scattering layer, and the resin curing method of the scattering layer was thermosetting. was prepared. In addition, the content of the black component of the scattering layer is set to 20% by weight, the maximum thickness of each scattering layer is set to 8.0 µm, a thermosetting resin is used for the material of the scattering layer, and the method for curing the resin of the scattering layer is thermosetting. Comparative Example 9 having the same configuration as Comparative Example 4 was prepared except that the film substrate was "Toyobo Ester Film E5007" manufactured by Toyobo Co., Ltd. which is a commercially available transparent PET film.

Here, the scattering layers of Comparative Examples 8 and 9 were manufactured using the following varnishes (coating liquid) containing a thermosetting resin. Specifically, 13.0 wt% of an epoxy resin as a thermosetting resin (“YDCN-703” manufactured by Toto Chemical Co., Ltd.), 11.0% by weight of a phenol resin (“XLC-LL” manufactured by Mitsui Chemicals Co., Ltd.), and Mikuni dye ( 34 wt% of “MHI Black #273” manufactured by Co., Ltd., 0.025 wt% of 1-cyanoethyl-2-phenylimidazole as a curing accelerator (“2PZ-CN” manufactured by Shikoku Chemical Co., Ltd.), and Fuji as particles 38 weight% of Silicia Chemical Co., Ltd. product "Silysia 448" was melt|dissolved in 4 weight% of cyclohexanone which is an organic solvent. Next, the varnish in which the nonvolatile matter was set to 15% was manufactured by mixing this with a bead mill. About Comparative Examples 4-9, the same measurement as Comparative Examples 1-3 was performed. The results are shown in Tables 3 and 4.

As shown in Tables 1, 3, and 4, Comparative Examples 4-9 has a clear difference from Examples 1-3 at the point that a film base material does not have light-shielding property. Compared with Examples 1-3, Comparative Example 4 had low light-shielding property, and it turned out that an appropriate optical density is not easily obtained. In Comparative Example 5, compared to Comparative Example 4, it was found that although the light-shielding property slightly improved due to the slightly increased content of the black component in the scattering layer, an appropriate optical density was still not easily obtained. In addition, in the scattering layer of Comparative Example 5, curing of the resin was insufficient, and poor transfer of the surface shape of the transfer member A was confirmed.

Moreover, in Comparative Example 6, since the resin of the scattering layer could not be sufficiently cured by the electron beam, poor molding of the scattering layer was confirmed. Moreover, with this molding defect, since the transfer member A could not be peeled from a scattering layer, it became a result that OD value, blackness (L ^* ), and glossiness could not be measured. Such uncured resin or poor molding of the resin of the scattering layer is considered to be due to the fact that ultraviolet rays and electron beams could not sufficiently penetrate into the coating film from the outside because the black component contained in the scattering layer was relatively large.

In addition, such non-curing of the resin of the scattering layer was also confirmed in Comparative Example 7, in which the maximum thickness of the scattering layer was relatively large. It was also found that in Comparative Example 8, since the resin of the scattering layer was cured by thermal curing, the light-shielding film thermally contracted during thermal curing of the resin of the scattering layer, and wrinkles were generated. In Comparative Example 9, since the thickness of the film substrate was significantly larger than that of Comparative Example 8, the generation of wrinkles confirmed in Comparative Example 8 was not observed, but it was found that the total thickness of the light-shielding film was also significantly increased. From the above test result, the superiority with respect to Comparative Examples 4-9 of Examples 1-3 was confirmed.

This invention is not limited to each embodiment, The structure and method can be changed, added, or deleted in the range which does not deviate from the meaning of this invention. The black component of the scattering layer may contain at least either a pigment or a dye.

Moreover, the unevenness|corrugation may be formed in the transfer surface 8a of the transfer member 8 by sandblasting process. Moreover, when the thermal contraction of the film base material 2 at the time of manufacture of the light-shielding film 1 does not become a very big problem, you may use a thermosetting resin as a precursor of the binder resin 6 . Moreover, the particle|grains 7 may be disperse|distributed inside the resin member 4 of 1st Embodiment.

In addition, when the resin member 4 is made of a resin material having ultraviolet curability and electron beam curability, the black component of the scattering layers 3 and 103 is within an allowable range that does not significantly affect the curing of the resin material. Content may be set to the value larger than 4 weight%.

Industrial Applicability

As mentioned above, this invention is a light-shielding film WHEREIN: It has the outstanding effect which can reduce thickness, maintaining favorable light-shielding property. Therefore, it is advantageous when this invention is widely applied to the manufacturing method of the light-shielding film and light-shielding film which can exhibit the significance of this effect.

1, 101: light-shielding film
2: film substrate
3, 103: scattering layer
3a, 103a: the surface of the scattering layer
4: no resin
5: black fine particles
7: Particles
8: no transfer
8a: transfer surface of transfer member

Claims (17)

The glossiness of at least one surface at an incident angle of 60 degrees is set to a value in the range of 0 or more and 10 or less,
The optical density in a value in the range of wavelength 380 nm or more and 780 nm or less is set to a value in the range of 4 or more,
A light-shielding film, wherein the total thickness is set to a value in the range of 6 µm or more and 26 µm or less. The method of claim 1,
A film substrate having light-shielding properties;
and a scattering layer disposed to overlap the film substrate and scattering incident light,
The light-shielding film, wherein the one surface is a surface of the scattering layer on the opposite side to the film substrate. 3. The method of claim 2,
The light-shielding film, wherein the content of the black component in the scattering layer is set to a value in a range greater than 0% by weight and not more than 4% by weight. 4. The method of claim 2 or 3,
wherein the scattering layer further includes a resin member disposed along the surface of the film substrate, and particles dispersed in the resin member. 5. The method of claim 4,
The light-shielding film in which the refractive index of the said resin member is set to the value in the range of 1.3 or more and 1.9 or less. 6. The method according to any one of claims 2 to 5,
The light-shielding film in which the thickness of the said film base material is set to the value of the range of 2 micrometers or more and 12 micrometers or less. 7. The method according to any one of claims 2 to 6,
The light-shielding film, wherein the thickness of the scattering layer is set to a value in the range of 3 µm or more and 7 µm or less. 8. The method according to any one of claims 2 to 7,
The light-shielding film, wherein the total light transmittance of the scattering layer is set to a value in the range of 70% or more and 100% or less. A preparation step of preparing a coating solution containing a resin material having ultraviolet curability and electron beam curability, and a film substrate having light-shielding properties;
A first step of forming a coating film on the surface by applying the coating solution to the surface of the film substrate and drying, and irradiating the coating film with ultraviolet rays;
a second step of irradiating an electron beam to the coating film irradiated with the ultraviolet rays;
By passing through the first step and the second step, from the coating film, a scattering layer whose glossiness at an incident angle of 60 degrees on the surface opposite to the film substrate is set to a value in the range of 0 or more and 10 or less is formed. together with the film substrate and the scattering layer, wherein the optical density in a value in the range of wavelength 380 nm to 780 nm is set to a value in the range 4 or more, and the total thickness is 6 µm or more and 26 µm or less The manufacturing method of the light-shielding film which forms the light-shielding film set to the value of the range. 10. The method of claim 9,
In the second step, a transfer member having an uneven transfer surface is disposed in the coating film so that the transfer surface is deposited on the surface opposite to the film substrate, and the coating film is irradiated with an electron beam to reduce the unevenness of the coating film. A method for producing a light-shielding film, wherein the scattering layer to which the shape is transferred is formed. 11. The method according to claim 9 or 10,
In the first step, the coating film is formed on both surfaces of the film substrate,
In said 2nd step, the manufacturing method of the light-shielding film which irradiates an electron beam to each said coating film by irradiating an electron beam to the said film base material so that it may permeate|transmit the said film base material from the single side side of the said film base material. 12. The method according to any one of claims 9 to 11,
In the said preparation step, the said coating liquid set so that content of the black component of the said scattering layer may become a range larger than 0 weight% and 4 weight% or less is prepared, The manufacturing method of a light-shielding film. 13. The method according to any one of claims 9 to 12,
In the said preparation step, the manufacturing method of the light-shielding film which further prepares the said coating liquid containing particle|grains. 14. The method according to any one of claims 9 to 13,
In the second step, the scattering layer including the resin member having a refractive index set to a value in the range of 1.3 or more and 1.9 or less is formed. 15. The method according to any one of claims 9 to 14,
In the said preparation step, the manufacturing method of the light-shielding film which prepares the said film base material whose thickness was set to the value of the range of 2 micrometers or more and 12 micrometers or less. 16. The method according to any one of claims 9 to 15,
In the second step, the scattering layer having a thickness in the range of 3 µm or more and 7 µm or less is formed from the coating film. 17. The method according to any one of claims 9 to 16,
In the second step, the scattering layer having a total light transmittance set to a value in the range of 70% or more and 100% or less is formed from the coating film, the method for producing a light-shielding film.

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