JP7209758B2 - Light-shielding film and light-shielding member - Google Patents

Description

The present disclosure relates to a light shielding film and a light shielding member.

2. Description of the Related Art A light shielding member as disclosed in Patent Document 1, for example, is used as a shutter of an optical component provided in a smartphone, a digital video camera, or the like, an aperture member, or a gap adjusting member arranged between a plurality of lenses. The light-shielding member is manufactured using, for example, a light-shielding film including a sheet-like base material and a light-shielding layer overlaid on the surface of the base material. Fine irregularities are formed on the surface of the light shielding layer. The light-shielding layer scatters incident light incident on the optical component from the outside to prevent reflection and shields the incident light.

Japanese Patent Publication No. 2010-534342

Along with the miniaturization of optical components, the light shielding member is required to have excellent light shielding properties even if the thickness is thin, for example. Also, the light-shielding film is formed by, for example, preparing a plurality of materials, stacking the materials, and curing the surfaces. Therefore, it is desired to efficiently manufacture a light shielding member having excellent light shielding properties.

Accordingly, an object of the present disclosure is to enable efficient production of a light shielding member having excellent light shielding properties.

In order to solve the above problems, a light-shielding film according to an aspect of the present disclosure includes a light-shielding sheet-like base material and a light-shielding sheet-like base material, which is disposed over the base material, and has unevenness on the surface opposite to the base material. and an anti-gloss layer that is more transparent than the substrate. The anti-gloss layer includes a binder resin, filler particles dispersed in the binder resin, and a coloring component dispersed in the binder resin. In this light-shielding film, the blackness (L ^* ), which is the lightness defined in JIS Z 8518, is set to a value in the range of 15 or less.

According to the above configuration, it is possible to impart anti-glare properties to the light-shielding film in which incident light from the outside is scattered by the unevenness of the surface of the anti-gloss layer. In addition, the coloring component can prevent incident light entering the anti-gloss layer from being reflected on the surface of the filler particles and emitted from the surface of the anti-gloss layer. In addition, the blackness (L ^* ), which is the lightness defined in JIS Z 8518, of the light-shielding film is set to a value in the range of 15 or less. Also, the anti-gloss layer is configured to be more transparent than the substrate. Therefore, the light-shielding property of the base material can be exhibited to the outside through the anti-gloss layer. As a result, a light-shielding film having low lightness and excellent light-shielding properties can be realized.

The anti-gloss layer can be formed, for example, by applying a coating liquid containing a binder resin precursor, filler particles, and a coloring component to the surface of the base material and curing the coating liquid. Further, by setting the content of the coloring component in the anti-gloss layer within the above range, it is possible to prevent the light-shielding property of the anti-gloss layer from becoming excessive due to the coloring component. Therefore, even if a photocurable resin such as an ultraviolet curable resin is used as the binder resin precursor, the binder resin can be cured by irradiating the binder resin precursor with light from the outside. Thereby, an anti-gloss layer can be efficiently formed. Therefore, the light shielding member can be efficiently manufactured using the light shielding film.

A content of the filler particles in the anti-gloss layer may range from 10 wt % to 25 wt %. This makes it easier to form irregularities on the surface of the anti-gloss layer. Also, the content of the coloring component in the anti-gloss layer may be in the range of more than 0 wt % and 5 wt % or less. Thereby, the reflected light reflected by the surface of the filler particles can be easily suppressed by the coloring component.

The coloring component may contain pigment fine particles having a smaller particle size than the filler particles. Thus, by arranging a plurality of pigment fine particles around the filler particles in the anti-gloss layer, the incident light entering the anti-gloss layer is reflected on the surface of the filler particles and emitted from the surface of the anti-gloss layer. can be more easily suppressed by the fine pigment particles.

The OD value in the wavelength range of 380 nm or more and 780 nm or less may be 5 or more. As a result, even better light shielding properties of the light shielding film can be obtained.

The total thickness may be in the range of 40 μm or less. By using a light-shielding film with a reduced total thickness, for example, a light-shielding member having excellent light-shielding properties can be compactly arranged in an optical component while suppressing an increase in the size of the optical component.

The base material includes a film member and a light-shielding layer having a light-shielding property higher than that of the film member and disposed over the film member. may be arranged so as to be on the anti-gloss layer side. Further, the substrate may contain a film member having a light shielding property. Thereby, the degree of freedom in designing the light shielding film can be improved.

A light-shielding member according to an aspect of the present disclosure includes a light-shielding sheet-like base material and a light-shielding sheet-like base material, which is disposed over the base material, and has unevenness formed on the surface opposite to the base material. a highly transparent anti-gloss layer, the anti-gloss layer comprising a binder resin, filler particles dispersed in the binder resin, and a coloring component dispersed in the binder resin; Blackness (L ^* ), which is lightness measured by measurement, is set to a value in the range of 3.1 or less.

According to the above configuration, it is possible to provide the light shielding member with an anti-glare property in which incident light from the outside is scattered by the unevenness of the surface of the anti-gloss layer. In addition, the coloring component can prevent incident light entering the anti-gloss layer from being reflected on the surface of the filler particles and emitted from the surface of the anti-gloss layer. This can satisfactorily reduce the brightness of the surface of the anti-gloss layer. Blackness (L ^* ), which is lightness measured by microscopic spectrometry, is set to a value in the range of 3.1 or less. Also, the anti-gloss layer is configured to be more transparent than the substrate. Therefore, the light-shielding property of the base material can be exhibited to the outside through the anti-gloss layer. As a result, a light shielding member having low lightness and excellent light shielding properties can be realized.

According to each aspect of the present disclosure, a light-shielding film having excellent light-shielding properties can be efficiently produced.

1 is a cross-sectional view of a light shielding film according to a first embodiment; FIG. FIG. 2 is a partially enlarged view of the light shielding film of FIG. 1; FIG. 5 is a cross-sectional view of a light shielding film according to a second embodiment; It is a figure which shows the cross section image|photographed with TEM (transmission electron microscope) of the light shielding film which concerns on 2nd Embodiment. FIG. 11 is an exploded view of an optical component according to a third embodiment;

Hereinafter, each embodiment and the like will be described with reference to the drawings. wt% in this disclosure is mass percent. Mass percent can also be expressed as weight percent, abbreviated wt%, or weight-weight percent. Mass percent is mass [g]/mass [g] concentration percentage notation and is different from mass concentration (kg/m ³ ).
(First embodiment)
[Light-shielding film]
FIG. 1 is a cross-sectional view of a light shielding film 1 according to the first embodiment. FIG. 2 is a partially enlarged view of the light shielding film 1 of FIG. The light-shielding film 1 shown in FIGS. 1 and 2 is used, as an example, for manufacturing light-shielding members for optical components. The light-shielding film 1 includes a light-shielding sheet-like base material 2 and at least one (here, a pair) anti-gloss layer 3 superimposed on the base material 2 . The substrate 2 has a higher light shielding property than the pair of anti-gloss layers 3 . In other words, anti-gloss layer 3 is more transparent than substrate 2 . That is, the anti-gloss layer 3 has a higher total light transmittance than the substrate 2 .

The term "total light transmittance" as used herein refers to transmittance measured by a method conforming to JIS K 7375:2008. In the light-shielding film 1 , the light-shielding properties of the substrate 2 are exhibited through the anti-gloss layer 3 . The total thickness of the light shielding film 1 is, for example, a value in the range of 40 μm or less. In another example, the total thickness of the light shielding film 1 is a value in the range of 50 μm or less. In another example, the total thickness of the light shielding film 1 is a value in the range of 25 μm or less.

The substrate 2 supports the anti-gloss layer 3 and provides the light-shielding film 1 with light-shielding properties. The base material 2 of this embodiment includes a film member having a light shielding property. As an example, the substrate 2 is a resin film containing a coloring component (here, a black component) and a resin component. Carbon black can be exemplified as the black component, but is not limited to this. As the resin component, polyethylene terephthalate (PET), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polycarbonate (PC), ethylene-methacrylic acid copolymer (EMAA) can be exemplified, but not limited thereto. The thickness of the base material 2 can be appropriately set in consideration of the total thickness of the light shielding film 1 . As an example, the thickness of the base material 2 is a value in the range of 4.5 μm or more and less than 25 μm. In yet another example, the thickness of the substrate 2 is in the range of 50 μm or less. The OD (optical density) value of the substrate 2 in the wavelength range of 380 nm or more and 780 nm or less is, for example, a value of 4 or more.

The anti-gloss layer 3 is placed over the substrate 2 . The anti-gloss layer 3 has irregularities formed on the surface opposite to the substrate 2 . The unevenness scatters incident light entering the anti-gloss layer 3 from the outside. Since the light-shielding film 1 includes the anti-gloss layer 3, the light-shielding film 1 has anti-glare properties.

The anti-gloss layer 3 includes a binder resin 30 having a total light transmittance in the range of 70% or more and less than 100%, filler particles 31 dispersed in the binder resin 30, and coloring dispersed in the binder resin 30. and component 32. The unevenness of the surface of the anti-gloss layer 3 is such that a plurality of filler particles 31 are dispersed and arranged in the binder resin 30, and the filler particles 31 protrude from the anti-gloss layer 3 on the opposite side of the base material 2 to form the binder resin. It is formed by raising the surface of 30 . The filler particles 31 are inorganic particles as an example. In this case, silica particles can be exemplified as the filler particles 31 . The filler particles 31 are not limited to a structure containing an inorganic material, and may be a structure containing an organic material.

The average particle size of the filler particles 31 can be set as appropriate. The average particle size of the filler particles 31 of the present embodiment is a value in the range of 2.0 μm or more and 5.0 μm or less. More preferably, the average particle diameter of the filler particles 31 is in the range of 2.5 μm or more and 4.5 μm or less. Further, it is more desirable that the average particle diameter of the filler particles 31 is in the range of 2.7 μm or more and 3.5 μm or less.

The coloring component 32 of this embodiment has a higher light absorption than the filler particles 31 . As shown in FIG. 2, the coloring component 32 contains pigment fine particles as an example. The fine pigment particles have a particle size smaller than that of the filler particles 31 . In the anti-gloss layer 3 , a plurality of fine pigment particles are dispersed around the filler particles 31 . As a result, in the anti-gloss layer 3, even when light enters the anti-gloss layer 3 from the outside, the reflected light reflected by the surface of the filler particles 31 is prevented from being emitted to the outside from the surface of the anti-gloss layer 3 again. Suppressed by pigment fine particles. The plurality of pigment fine particles may be arranged in the form of primary particles that are separated from each other, or may be arranged in the form of secondary particles that are agglomerated in a certain number.

Examples of the coloring component 32 include, but are not limited to, pigments and dyes. Examples of the coloring component 32 include carbon black, lamp black, vine black, peach black, bone char, carbon nanotubes, silver oxide, zinc oxide, magnetite-type triiron tetraoxide, a composite oxide of copper and chromium, copper, and chromium. , zinc complex oxide, black glass, and the like. The coloring component 32 of the present embodiment contains carbon black (carbon fine particles) as fine pigment particles.

The content of the filler particles 31 in the anti-gloss layer 3 is a value in the range of 10 wt % or more and 25 wt % or less. By setting the lower limit of the content of the filler particles 31 in the gloss-preventing layer 3 to 10 wt %, the glossiness of the surface of the gloss-preventing layer 3 can be suppressed and the gloss-preventing layer 3 can be easily imparted with a black tint. By setting the upper limit of the content of the filler particles 31 in the gloss-preventing layer 3 to 25 wt %, it is possible to prevent the brightness (L ^* ) of the gloss-preventing layer 3 from increasing due to the filler particles 31 .

The content of the coloring component 32 in the anti-gloss layer 3 is a value in the range of more than 0 wt % and 5 wt % or less. The lower limit of the content of the coloring component 32 in the anti-gloss layer 3 may be either 1 wt% or 2 wt%. By setting the lower limit of the content of the coloring component 32 in the gloss-preventing layer 3 to 1 wt %, it is possible to easily impart an appropriate blackness to the gloss-preventing layer 3 . In addition, by setting the upper limit of the content of the coloring component 32 in the anti-gloss layer 3 to 5 wt%, the surface roughness (Ra) of the anti-gloss layer 3 is appropriately maintained, and the coloring component 32 makes the anti-gloss layer 3 black. It is possible to easily prevent the taste from deteriorating.

Considering the application to the anti-gloss layer 3, the binder resin 30 of the present embodiment has a total light transmittance in the range of 70% or more and 100% or less, as an example. As another example, the binder resin 30 includes at least one of thermoplastic resin, thermosetting resin, and photo-curable resin. Therefore, a wide range of resins can be selected as the binder resin 30 . Thereby, in the light shielding film 1, each function of the resin used for the binder resin 30 can be exhibited.

Examples of thermoplastic resins include polyolefins, styrene resins, acrylic resins, vinyl chloride resins, polyvinyl alcohol resins, polyacetals, polyesters, polycarbonates, polyamides, polyimides, polysulfone resins, polyphenylene ether resins, and polyphenylene sulfide resins. One or more of resins, fluororesins, cellulose derivatives, polyurethane resins and the like can be exemplified. Among these, cyclic polyolefins, polyalkylene arylates (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polymethyl methacrylate resins, bisphenol A type polycarbonate, and cellulose esters are suitable, for example, from the viewpoint of strength.

As the thermosetting resin, one or more of phenol resin, melamine resin, urea resin, benzoguanamine resin, silicone resin, epoxy resin, unsaturated polyester, vinyl ester resin, polyurethane and the like can be exemplified. Among these, epoxy resin, unsaturated polyester, silicone resin, and polyurethane are suitable from the viewpoint of strength.

As the photocurable resin, for example, one or more of photocurable polyester, photocurable acrylic resin, photocurable epoxy (meth)acrylate, and photocurable urethane (meth)acrylate can be exemplified. Of these, photocurable acrylic resins and photocurable urethane (meth)acrylates are preferable from the viewpoint of strength. The term "photocurability" as used herein refers to the property of being polymerized and cured by light of a specific wavelength.

The anti-gloss layer 3 has an OD value of 2 or less in the wavelength range of 380 nm or more and 780 nm or less. As a result, the light shielding property of the substrate 2 can be easily exhibited to the outside through the anti-gloss layer 3 while imparting an appropriate blackness to the anti-gloss layer 3 .

The light-shielding film 1 has a lightness (L ^* ) defined in JIS Z 8518: 1998 in the range of 15 or less (14 or less as an example, 13.7 or less or 13.2 or less in another example). value. In the light-shielding film 1, the surface of the anti-gloss layer 3 opposite to the substrate 2 has an arithmetic average roughness (Ra) of 0.2 to 0.8 μm. The arithmetic mean roughness (Ra) of this surface is more preferably in the range of 0.4 to 0.6 μm. In the light-shielding film 1, the glossiness of the surface of the anti-gloss layer 3 opposite to the substrate 2 at an incident angle of 60 degrees is a value in the range of 0.5 or less.

Here, when measuring the blackness (L ^* ), which is the lightness defined in JIS Z 8518, for example, a sample is irradiated with light and reflected light from the sample is used for reflection measurement. According to the integrating sphere method, the light reflected from the surface of the sample brightens the interior of the integrating sphere, and the amount of light can be measured by the detector. In this case, the measured value is the reflectance (relative reflectance) when the reflectance of the reflection reference (standard white board) is 100%. It is necessary to use different measurement methods according to the type and shape of the sample to be measured, and the purpose and application of the measurement. In the integrating sphere method, the SCI (including specular reflection) method, which measures both regular reflection light and diffuse reflection light, is suitable for quantifying the blackness (L ^* ) of the sample surface. In this document, a spectrophotometer ("U-3900H" manufactured by Hitachi High-Tech Science Co., Ltd.) is used, and the blackness (L ^* ) is calculated based on the reflectance in the wavelength range of 380 nm or more and 780 nm or less based on the SCI method. bottom.

The OD value was obtained by irradiating the sample with a vertical transmitted light beam using an optical densitometer (manufactured by Videojet X-Rite Co., Ltd., "X-Rite 341C") and comparing the ratio to the state without the sample by log (logarithm). It can be measured by expressing with The beam width in this case can be measured as a circle with a diameter of 2 mm. Further, the OD value of the anti-gloss layer 3 can be calculated, for example, by dividing the value obtained by subtracting the OD value of the substrate 2 from the OD value of the entire light-shielding film 1 by the number of the anti-gloss layers 3. be.

For the average particle diameter, for example, a field emission scanning electron microscope ("JSM-6700F" manufactured by JEOL Ltd.) is used to take a photograph of the particle surface magnified 100,000 times. The magnified photograph is further magnified as necessary, and the particle size of 50 or more particles is calculated by dividing by the magnifying power using a ruler, vernier caliper, or the like. The average particle size can be calculated as the average value of the calculated values.

The glossiness at an incident angle of 60 degrees (specular glossiness based on the measurement method conforming to JIS Z 8741:1997) can be measured using a gloss meter. Arithmetic mean roughness (Ra) is center line mean surface roughness and is calculated according to the definition of JIS B 0601:1994. The total light transmittance can be measured based on a measuring method conforming to JIS K 7361:1997.

Next, a method for manufacturing the light shielding film 1 will be exemplified. The manufacturing method of the light-shielding film 1 of this embodiment has a forming step of forming the anti-gloss layer 3 to be superimposed on the substrate 2 . In this forming step, a coating liquid containing a binder resin precursor, filler particles 31, and a coloring component 32 is applied to the surface of the sheet-shaped base material 2 and adhered thereto. 30 is generated. As a result, the filler particles 31 and the coloring component 32 are dispersed in the binder resin 30 to form the anti-gloss layer 3 overlaid on the substrate 2 .

In the forming step, a binder resin precursor having a total light transmittance of the binder resin 30 in the range of 70% or more and less than 100% is used, and the content of the filler particles 31 in the antigloss layer 3 is , is a value in the range of 10 wt% or more and 25 wt% or less, and the content of the coloring component 32 in the gloss prevention layer 3 is diluted with a solvent so that the value is in the range of more than 0 wt% and 5 wt% or less. The above coating liquid is used.

As a specific example, the operator prepares the coating liquid as a material for the anti-gloss layer 3 . Next, the operator applies this coating liquid to the surface of the substrate 2 . The operator may then react the binder resin precursor in the coating liquid to form the binder resin 30 . Here, when the binder resin 30 contains a photocurable resin, the operator generates the binder resin 30 by irradiating the coating liquid with light. When the binder resin 30 contains a thermosetting resin, the operator heats the residual resin precursor after removing the solvent from the coating liquid to produce the binder resin 30 .

Thus, in the manufacturing method of this embodiment, the binder resin 30 is generated by light irradiation or heating. The surface shape of the anti-gloss layer 3 is formed by filler particles 31 . Thus, the light shielding film 1 is manufactured. According to this method, the anti-gloss layer 3 is formed with the coating liquid applied to the surface of the substrate 2 . Therefore, the number of manufacturing steps of the light shielding film 1 can be reduced. Further, for example, a transfer member for transferring the uneven shape to the surface of the anti-gloss layer 3 is not required. Therefore, the light shielding film 1 can be manufactured continuously and efficiently.

As described above, according to the light-shielding film 1 , it is possible to provide the light-shielding film 1 with an anti-glare property in which incident light from the outside is scattered by the irregularities on the surface of the anti-gloss layer 3 . In addition, the coloring component 32 can prevent incident light entering the anti-gloss layer 3 from being reflected by the surface of the filler particles 31 and emitted from the surface of the anti-gloss layer 3 . In addition, the light-shielding film 1 has a blackness (L ^* ), which is lightness defined in JIS Z 8518, set to a value in the range of 15 or less. Also, the anti-gloss layer 3 is configured to be more transparent than the substrate 2 . Therefore, the light shielding property of the substrate 2 can be exhibited to the outside through the anti-gloss layer 3 . As a result, the light-shielding film 1 having low lightness and excellent light-shielding properties can be realized.

Further, such an anti-gloss layer 3 can be formed, for example, by applying a coating liquid containing a precursor of the binder resin 30, filler particles 31, and a coloring component 32 to the surface of the base material 2 and curing the coating liquid. . Further, by setting the content of the coloring component 32 in the anti-gloss layer 3 within the above range, it is possible to prevent the light-shielding property of the anti-gloss layer 3 from becoming excessive due to the coloring component 32 . Therefore, even if a photocurable resin such as an ultraviolet curable resin is used as the binder resin precursor, the binder resin 30 can be cured by irradiating the binder resin precursor with light from the outside. Thereby, the anti-gloss layer 3 can be efficiently formed. Therefore, the light shielding member can be manufactured efficiently using the light shielding film 1 .

In addition, the content of the filler particles 31 in the anti-gloss layer 3 of the present embodiment is in the range of 10 wt % or more and 25 wt % or less. This makes it easier to form irregularities on the surface of the anti-gloss layer 3 . Moreover, the content of the coloring component 32 in the gloss preventing layer 3 is a value in the range of more than 0 wt % and 5 wt % or less. Thereby, the reflected light reflected by the surface of the filler particles 31 can be easily suppressed by the coloring component 32 .

Further, the total light transmittance of the gloss preventing layer 3 is a value in the range of 10% or more and 40% or less. As a result, the light shielding property of the substrate 2 can be easily exhibited to the outside through the anti-gloss layer 3 while imparting an appropriate blackness to the anti-gloss layer 3 . Also, the anti-gloss layer 3 can be formed more efficiently by using a photocurable resin such as an ultraviolet curable resin as the binder resin precursor.

In the light-shielding film 1, for example, the average particle size of the filler particles 31 is a value in the range of 2.0 μm or more and 5.0 μm or less. As a result, unevenness on the surface of the anti-gloss layer 3 can be appropriately formed, and better light dispersion can be obtained.

Further, the coloring component 32 of the present embodiment contains pigment fine particles having a smaller particle size than the filler particles 31 . Accordingly, by arranging a plurality of pigment fine particles around the filler particles 31 in the anti-gloss layer 3 , the incident light entering the anti-gloss layer 3 is reflected on the surface of the filler particles 31 and the anti-gloss layer 3 is Emission from the surface can be suppressed more easily than the fine pigment particles.

In the light-shielding film 1, for example, the OD value of the anti-gloss layer 3 in the wavelength range of 380 nm or more and 780 nm or less is 2 or less. Thereby, the light shielding property of the base material 2 can be easily exhibited to the outside through the anti-gloss layer 3 .

As an example, the light-shielding film 1 has an OD value of 4 or more in the wavelength range of 380 nm or more and 780 nm or less of the substrate 2 . Thereby, the light shielding property of the substrate 2 can be further improved.

As an example, the light-shielding film 1 has an OD value of 5 or more in the wavelength range of 380 nm or more and 780 nm or less. As a result, the light-shielding film 1 can have even better light-shielding properties.

Further, the total thickness of the light shielding film 1 of the present embodiment is, for example, within a range of 40 μm or less. By using the light-shielding film 1 having a reduced total thickness in this way, for example, it is possible to compactly arrange a light-shielding member having excellent light-shielding properties inside the optical component while suppressing an increase in the size of the optical component.

In the light shielding film 1, the filler particles 31 are inorganic particles. Further, the binder resin 30 contains at least one of a photocurable resin and a thermosetting resin. Moreover, the base material 2 contains the film member which has a light-shielding property. Thereby, the degree of freedom in designing the light shielding film 1 can be improved. Other embodiments will be described below, focusing on differences from the first embodiment.

(Second embodiment)
FIG. 3 is a cross-sectional view of the light shielding film 101 according to the second embodiment. As shown in FIG. 3 , the base material 20 of the light shielding film 101 includes a film member 21 and light shielding layers 22 and 23 placed over the film member 21 . The film member 21 has, for example, a total light transmittance in the range of 80% or more and less than 100%. The film member 21 is, for example, a resin film containing a resin component such as PET or PI. The light shielding layers 22 and 23 contain a binder resin and a coloring component. This coloring component includes, for example, fine pigment particles as in the first embodiment. The light shielding layers 22 and 23 have a light shielding property higher than that of the film member 21 . The film member 21 may be thinner or thicker than the light shielding layers 22 and 23 .

In the light-shielding film 101 , the light-shielding layers 22 and 23 of the film member 21 and the light-shielding layers 22 and 23 are arranged on the anti-gloss layer 3 side. The base material 20 of the light shielding film 101 should have at least one light shielding layer. As a specific example, the light-shielding film 101 of this embodiment includes a pair of light-shielding layers 22 and 23 and a pair of anti-gloss layers 3 . The light-shielding film 101 has the surface of the film member 21 covered with the light-shielding layers 22 and 23 on both sides of the film member 21, and the surface of the light-shielding layer 23 opposite to the film member 21 is covered with the anti-gloss layer 3. there is The overall light shielding property of the base material 20 is set to be the same as that of the base material 2 .

Even with the light-shielding film 101 having the above configuration, the same effects as those of the light-shielding film 1 can be obtained. Also, the film member 21 and the light shielding layers 22 and 23 can be functionally separated. Thereby, the degree of freedom in designing the light shielding film 101 can be improved.

FIG. 4 is a diagram showing a cross section of the light shielding film 101 according to the second embodiment taken with a TEM (transmission electron microscope). As shown in FIG. 4, by using a TEM, the film member 21 and the light shielding layer 23 in the base material 20 of the light shielding film 101 can be clearly distinguished and confirmed. The film member 21 and the light shielding layer 23 can be clearly identified by, for example, relatively dark coloring due to pigment fine particles such as carbon black contained in the light shielding layer 23 . Further, the light shielding layer 23 and the anti-gloss layer 3 can be clearly identified due to the difference in color density due to pigment fine particles such as carbon black contained in each layer. Although not shown, the base material 2 and the anti-gloss layer 3 of the first embodiment can also be clearly confirmed due to the difference in color density due to pigment fine particles such as carbon black contained in each.

(Third Embodiment)
FIG. 5 is an exploded view of the optical component 40 according to the third embodiment. As shown in FIG. 5, the optical component 40 includes a plurality of light shielding members F1 to F6, a plurality of optical members (here, lenses L1 to L6), and a housing (mirror) housing the light shielding members F1 to F6 and the optical members. cylinder) 41 is provided. As an example, the light shielding members F1 to F6 are arranged between adjacent optical members so as to surround the optical axis R of the optical members. The number of light shielding members provided in the optical component 40 and the number of optical members are not limited.

The light shielding members F1 to F6 have the same cross-sectional structure as the light shielding film 1 of the first embodiment. That is, each of the light shielding members F1 to F6 includes a light shielding sheet-like base material 2 (or base material 20) and an anti-gloss layer 3. FIG. The anti-gloss layer 3 includes a binder resin 30 , filler particles 31 dispersed in the binder resin 30 , and a coloring component 32 dispersed in the binder resin 30 . The light shielding members F1 to F6 have blackness (L ^* ), which is lightness measured by microscopic spectrometry, set to a value in the range of 3.1 or less.

According to the third embodiment, the light shielding members F1 to F6 can be provided with an antiglare property in which the incident light from the outside is scattered by the irregularities on the surface of the antigloss layer 3 . In addition, the coloring component can prevent incident light entering the anti-gloss layer 3 from being reflected by the surface of the filler particles 31 and emitted from the surface of the anti-gloss layer 3 . As a result, the brightness of the surface of the anti-gloss layer 3 can be favorably reduced. Blackness (L ^* ), which is lightness measured by microscopic spectrometry, is set to a value in the range of 3.1 or less. Also, the anti-gloss layer 3 is configured to be more transparent than the substrate 2 (or substrate 20). Therefore, the light shielding property of the substrate 2 (or the substrate 20) can be exhibited to the outside through the anti-gloss layer 3. As a result, the light shielding members F1 to F6 having low lightness and excellent light shielding properties can be realized.

As a method for measuring this blackness (L ^* ), for example, a near-infrared spectrophotometer "USPM-RU-W" manufactured by Olympus Co., Ltd. is used as a microspectrophotometer, an objective lens magnification of 40 times, and a light source of D65. , a measurement NA of 0.24, a measurement range of 17.5 μm, and a measurement wavelength of 380 nm or more and 1050 nm or less.

Further, the content of the coloring component 32 in the anti-gloss layer 3 included in the light-shielding film 1 and the light-shielding members F1 to F6 can be confirmed by, for example, the following method. First, a captured image of a cross section of the light shielding film 1 and the light shielding members F1 to F6 of interest is obtained using a TEM (transmission electron microscope). Next, the area of each colored component 32 in this photographed image is measured. Based on this area value, the total volume of the coloring components 32 in the anti-gloss layer 3 when the coloring components 32 are regarded as spherical particles is calculated. Based on this volume value and the known density of the coloring component 32, the content is calculated.

(confirmation test)
Next, confirmation tests will be described, but the present disclosure is not limited to the examples shown below. A light-shielding film 101 was produced as Example 1. A PET film (manufactured by Toray Industries, Inc.) having a thickness of 4.5 μm and a total light transmittance of 87.6% was used as the film member 21 . A material containing urethane-based binder resin ("Byron 40SS" manufactured by Toyobo Co., Ltd.) and carbon black ("MHI Black #273" manufactured by Mikuni Shiso Co., Ltd.) having a weight ratio of 12 wt% with respect to the light shielding layer 23 is used for the film member 21. A pair of light shielding layers 23 having a thickness of 1.5 μm after drying was formed by coating both surfaces and thermally curing. As a result, the substrate 20 having an OD value of 5.3 in the wavelength range of 380 nm or more and 780 nm or less was formed.

Also, the anti-gloss layer 3 was formed by the following procedure. Thermosetting binder resin (“KDC-03” manufactured by Koshin Chemical Co., Ltd.) as binder resin 30, inorganic (silica) particles as filler particles 31 (“Silysia 420” manufactured by Fuji Silysia Co., Ltd. Average particle size 2 .9 μm), and carbon black (“MHI Black #273” manufactured by Mikuni Shiso Co., Ltd., average particle size 0.15 μm), which is the coloring component 32 with a weight of 9 wt % with respect to the anti-gloss layer 3. was coated on both sides of the film, dried and cured. A pair of anti-gloss layers 3 each having a thickness of 4.0 μm after drying were formed. As described above, the light-shielding film 101 of Example 1 having a total thickness in the range of 25 μm or less (specifically, 15 μm or more and 16 μm or less) was produced.

In addition, in the production of the anti-gloss layer 3, instead of using a thermosetting binder resin ("KDC-03" manufactured by Koshin Chemical Co., Ltd.), an ultraviolet curable resin ("HR-370- 192") was prepared in the same manner as in Example 1 except that the light-shielding film 101 of Example 2 was prepared. Further, a light-shielding film 1 of Example 3 was prepared in the same manner as in Example 1 except that a 12 μm-thick black PET film (black light-shielding PET manufactured by Nanya Co., Ltd.) was used as the base material 2 . Further, the light-shielding film 1 of Example 4, which was the same as Example 1 except that a 12 μm thick light-shielding and heat-resistant kneaded black PI film (PI film manufactured by Timeid Technology Co., Ltd.) was used as the base material 2, was used. made.

Further, a comparative example similar to Example 3 except that a transparent substrate of a PET film (PET film manufactured by Toray Industries, Inc.) having a thickness of 4.5 μm and a total light transmittance of 87.6% was used as the substrate. A light-shielding film No. 1 was produced. In addition, in the preparation of the surface layer corresponding to the gloss prevention layer 3, a thermosetting binder resin (“KDC-03” manufactured by Koshin Chemical Co., Ltd.) and carbon black (“MHI Black #273” manufactured by Mikuni Color Co., Ltd.) ) was prepared in the same manner as in Comparative Example 1, except that the ratio of .

Here, in the preparation of the surface layer, instead of using a thermosetting binder resin (“KDC-03” manufactured by Koshin Chemical Co., Ltd.), an ultraviolet curable resin (“HR-370-192” manufactured by Yokohama Rubber Co., Ltd. ) was used to produce a light-shielding film of Comparative Example 3, which was the same as Comparative Example 2, it was confirmed that a surface layer could not be formed.

In addition, the same base material as in Example 1 was used as the base material. ”) and carbon black (“MHI Black #273” manufactured by Mikuni Color Co., Ltd.).

In addition, the same base material as in Example 3 was used as the base material, and in the preparation of the surface layer, "Silysia 420" manufactured by Fuji Silysia Co., Ltd., a thermosetting binder resin ("KDC-03" manufactured by Koshin Chemical Co., Ltd. ”) and carbon black (“MHI Black #273” manufactured by Mikuni Color Co., Ltd.) at a predetermined ratio.

Further, a light-shielding film of Comparative Example 6 was prepared in the same manner as in Comparative Example 5 except that the same base material as in Example 1 was used as the base material. In addition, in the preparation of the surface layer, "Silysia 420" manufactured by Fuji Silysia Co., Ltd., a thermosetting binder resin ("KDC-03" manufactured by Koshin Chemical Co., Ltd.), and carbon black (manufactured by Mikuni Color Co., Ltd. " Light-shielding films of Comparative Examples 7 and 8 were prepared in the same manner as in Comparative Example 6, except that the ratio of MHI Black #273") was changed from that in Comparative Example 6.

For the surfaces of the anti-gloss layers 3 of Examples 1 to 4 and the surface layers of Comparative Examples 1, 2 and 4 to 8, the glossiness at an incident angle of 60 degrees was measured using a gloss meter. Further, for Examples 1 to 4 and Comparative Examples 1, 2, 4 to 8, the lightness (L ^* ) of the light-shielding film was measured by a measurement method based on JIS Z 8518 and a measurement method based on microscopic spectrometry. For Examples 1 to 4 and Comparative Examples 1, 2, and 4 to 8, the OD value was measured in the wavelength range of 380 nm or more and 780 nm or less of the light-shielding film using an optical densitometer. The surface roughness (Ra) of the surfaces of the anti-gloss layers 3 of Examples 1 to 4 and the surface layers of Comparative Examples 1, 2 and 4 to 8 were measured using a surface roughness meter. The surface of the anti-gloss layer 3 of Examples 1-4 and the surface layers of Comparative Examples 1, 2 and 4-8 were measured for pencil hardness according to JIS K 5600:1999. However, the load was a 500g load. The compositions of Examples 1-4 and Comparative Examples 1-8 and the measurement results are shown in Tables 1-3.

As shown in Tables 1 to 3, for Examples 1 to 4, it was confirmed that light-shielding films 1 and 101 having good light-shielding properties and OD values were obtained. In addition, since the anti-gloss layer 3 is configured to allow light to pass therethrough, even when an ultraviolet curable resin is used as the material of the anti-gloss layer 3 as in Example 2, a sufficient amount of light from the outside enters the material. of ultraviolet rays can be irradiated, and it was confirmed that an anti-gloss layer 3 having excellent hardness can be formed. Further, in Examples 1 to 4, the surface of the anti-gloss layer 3 has a pencil hardness (higher pencil hardness than HB) that is equal to or higher than that of the surfaces of the surface layers of Comparative Examples 1 to 2 and 4 to 8. confirmed. As a result, it was confirmed that in Examples 1 to 4, the anti-gloss layer 3 had sufficient hardness.

On the other hand, in Comparative Example 1, as a result of using the above-mentioned transparent base material as the base material, both the lightness (L ^* ) and the OD value were inferior to those of Examples 1 to 4, and sufficient light shielding properties were obtained. It was confirmed that Further, as in Comparative Example 2, when the addition amount of the black component (carbon black) in the surface layer corresponding to the anti-gloss layer of the example is increased more than in Comparative Example 1, the light shielding property is improved, but the surface of the surface layer It was confirmed that the lightness (L ^* ) was increased by reducing the roughness and increasing the glossiness of the surface of the surface layer.

In addition, as in Comparative Example 3, when the amount of the black component (carbon black) added to the surface layer is large, when an ultraviolet curable resin is used as the material of the surface layer, a sufficient amount of UV light is irradiated into the material from the outside. It was also found that the ultraviolet curable resin could not be cured and the surface layer could not be formed because it was not possible. Accordingly, in Comparative Example 3, it was confirmed that it was difficult to make the ultraviolet curable resin function as, for example, a binder resin.

Further, from the results of Comparative Example 4, it was confirmed that even when the same material as in Example 1 was used as the base material, the lightness (L ^* ) of the light-shielding film increased when the amount of the black component added to the surface layer was small. was done. Further, from the results of Comparative Examples 5 and 6, even if either the base material 2 (kneaded PET) or the base material 20 (light-shielding layer/film member/light-shielding layer three-layer structure) is used as the base material of the light-shielding film, It was confirmed that when the amount of the black component added to the surface layer is too large, the surface roughness of the surface layer decreases and the glossiness of the surface of the surface layer increases, resulting in a lightness (L ^* ) higher than 18. was done.

Further, from the results of Comparative Example 7, if the amount of filler particles ("Sylysia 420" manufactured by Fuji Silysia Co., Ltd.) added to the surface layer is too small, the matte surface of the surface layer cannot be obtained, and the surface is glossy. It was confirmed that the blackness of the light-shielding film decreased as the degree increased. Further, from the results of Comparative Example 8, when the amount of filler particles ("Sylysia 420" manufactured by Fuji Silysia Co., Ltd.) added to the surface layer is too large, the surface glossiness of the surface layer decreases, but the whiteness of the particles increases. It was confirmed that the blackness of the light-shielding film was reduced by adding From the above, the superiority of Examples 1 to 4 was confirmed.

Each configuration and combination thereof in each embodiment is an example, and addition, omission, replacement, and other changes of configuration are possible as appropriate without departing from the gist of the present disclosure. This disclosure is not limited by the embodiments, but only by the claims. Also, each aspect disclosed in this specification may be combined with any other feature disclosed in this specification.

F1-F6 light-shielding member L1-L6 lens 1, 101 light-shielding film 2, 20 base material 3 anti-gloss layer 21 film member 22, 23 light-shielding layer 30 binder resin 31 filler particles 32 coloring component 40 optical component 41 housing

Claims (9)

a sheet-shaped base material having a light-shielding property;
An anti-gloss layer disposed over the base material, unevenness is formed on the surface opposite to the base material, and is more transparent than the base material,
The anti-gloss layer is
a binder resin;
Filler particles dispersed in the binder resin and having an average particle diameter in the range of 2.0 μm or more and 5.0 μm or less;
and a coloring component dispersed in the binder resin,
The content of the coloring component in the anti-gloss layer is a value in the range of more than 0 wt% and 5 wt% or less,
An optical shutter, aperture member, or a gap adjustment member arranged between a plurality of lenses, in which the blackness (L ^* ), which is the lightness defined in JIS Z 8518, is set to a value in the range of 15 or less. A light-shielding film. 2. The light-shielding film according to claim 1, wherein the content of said filler particles in said anti-gloss layer is in the range of 10 wt % or more and 25 wt % or less. 3. The light-shielding film according to claim 1, wherein the content of the coloring component in the anti-gloss layer is in the range of 1 wt % or more and 5 wt % or less . The light-shielding film according to any one of claims 1 to 3, wherein the coloring component contains pigment fine particles having a smaller particle size than the filler particles. 5. The light-shielding film according to claim 1, which has an OD value of 5 or more in a wavelength range of 380 nm or more and 780 nm or less. The light-shielding film according to any one of claims 1 to 5, wherein the total thickness is in the range of 40 µm or less. The base material includes a film member and a light-shielding layer having a higher light-shielding property than the film member and disposed over the film member,
7. The light-shielding film according to claim 1, wherein between the film member and the light-shielding layer, the light-shielding layer is arranged on the anti-gloss layer side. The light-shielding film according to any one of claims 1 to 7, wherein the base material includes a film member having light-shielding properties. a sheet-shaped base material having a light-shielding property;
An anti-gloss layer disposed over the base material, unevenness is formed on the surface opposite to the base material, and is more transparent than the base material,
The anti-gloss layer is
a binder resin;
Filler particles dispersed in the binder resin and having an average particle diameter in the range of 2.0 μm or more and 5.0 μm or less;
and a coloring component dispersed in the binder resin,
The content of the coloring component in the anti-gloss layer is a value in the range of more than 0 wt% and 5 wt% or less,
Blackness (L ^* ), which is the lightness measured by microscopic spectrometry, is set to a value in the range of 3.1 or less. An optical shutter, an aperture member, or a gap adjustment arranged between a plurality of lenses. A light shielding member that is a member.

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