Method for manufacturing resin molded body, resin molded body, and light shielding component

Abstract

In this manufacturing of a resin molded body for a light shielding component, the resin molded body having a plurality of protrusions on the surface thereof, an exposure step for exposing, in a layer made of a photosensitive resin, a portion in which the protrusions are to be formed and a development step for developing the exposed layer to form the protrusions on the surface of the layer are performed.

Description

Method for manufacturing a resin molded body, resin molded body, and light-shielding component

[0001] The present invention relates to a method for manufacturing a resin molded body, a resin molded body, and a light-shielding component.

[0002] Conventionally, a light-shielding member for an optical device having a light-shielding film containing a binder resin, black fine particles, and a matting agent is known (for example, see Patent Document 1 below).

[0003] International Publication No. 2012 / 132727

[0004] In the light-shielding member for an optical device as described in Patent Document 1 above, the matting agent imparts an uneven shape to the surface of the light-shielding film. Therefore, the state of the surface of the light-shielding film varies depending on the dispersion state of the matting agent, and there is a possibility that the dulling effect varies for each product.

[0005] The present invention provides a method for manufacturing a resin molded body, a resin molded body, and a light-shielding component that can impart a stable dulling effect to a light-shielding component using the obtained resin molded body.

[0006] The present invention [1] is a method for manufacturing a resin molded body, wherein the resin molded body is for a light-shielding component and has a plurality of protrusions on its surface, and the method for manufacturing the resin molded body includes an exposure step of exposing a portion of a layer made of a photosensitive resin where the protrusions are to be formed, and a development step of developing the exposed layer to form the protrusions on the surface of the layer.

[0007] According to such a method, protrusions having a desired shape can be arranged at desired positions by photolithography.

[0008] Therefore, it is possible to suppress variations in the position and shape of the protrusions for each product.

[0009] As a result, a stable dulling effect can be imparted to a light-shielding component using the obtained resin molded body.

[0010] The present invention [2] includes the method for manufacturing a resin molded body according to [1] above, wherein in the exposure step, the layer is subjected to harmonic exposure through a photomask including a dot pattern composed of a plurality of dots.

[0011] This method allows for the placement of protrusions of a desired shape at a desired position through a simple process of gradual exposure via a photomask.

[0012] The present invention [3] includes a method for manufacturing the resin molded article according to [2] above, wherein the diameter of the dots is 3 μm or more.

[0013] This method ensures that the diameter of the protrusions on the surface of the resulting resin molded body is maintained.

[0014] Therefore, light reflection on the surface of the resulting resin molded body can be suppressed.

[0015] As a result, the matte finish of the light-shielding component using the resulting resin molded body can be improved.

[0016] The present invention [4] includes a method for manufacturing the resin molded article according to [2] or [3] above, wherein the spacing between each of the plurality of dots is 0.5 μm or more.

[0017] This method ensures that the height of the protrusions on the surface of the resulting resin molded body can be secured.

[0018] Therefore, light reflection on the surface of the resulting resin molded body can be suppressed.

[0019] As a result, the matte finish of the light-shielding component using the resulting resin molded body can be improved.

[0020] The present invention [5] includes a resin molded body for light-shielding components, having a plurality of protrusions on its surface, wherein the diameter of the protrusions is 3 μm or more.

[0021] This configuration makes it possible to suppress light reflection on the surface of the resin molded body.

[0022] As a result, the matte finish of light-shielding parts made from resin molded materials can be improved.

[0023] The present invention [6] includes the resin molded article of [5] above, wherein the height of the protrusion is 0.5 μm or more.

[0024] This configuration allows for greater suppression of light reflection on the surface of the resin molded body.

[0025] As a result, the matte finish of light-shielding parts made from resin molded materials can be improved.

[0026] The present invention [7] includes any one of the resin molded articles described in [5] to [6] above, wherein the spacing between each of the plurality of protrusions is 0.5 μm or more.

[0027] The present invention [8] includes any one of the above [5] to [7] resin molded articles containing a black pigment.

[0028] The present invention [9] includes any one of the above [5] to [8] resin molded articles, wherein the specular reflectance of the surface is 7.0% or less.

[0029] This configuration ensures that light reflection on the surface of the resin molded body is reliably suppressed.

[0030] As a result, it is possible to reliably improve the matte finish of light-shielding parts using resin molded materials.

[0031] The present invention

[10] includes a light-shielding component comprising any one of the resin molded bodies described in [5] to [9] above.

[0032] With this configuration, since the resin molded body described above is included, light reflection can be stably suppressed.

[0033] The present invention

[11] includes the light-shielding component of

[10] , further comprising a support layer for supporting the resin molded body.

[0034] With this configuration, the support layer ensures the rigidity of the light-shielding component.

[0035] The present invention

[12] includes the light-shielding component of

[10] or

[11] , further comprising a coating layer that covers the surface of the resin molded body.

[0036] The present invention

[13] includes the light-shielding component of

[12] above, wherein the coating layer is made of a metal oxide.

[0037] According to the method for manufacturing a resin molded article of the present invention, a stable matte finish can be imparted to a light-shielding component using the obtained resin molded article.

[0038] Furthermore, the resin molded article of the present invention can provide a stable matte finish to light-shielding components.

[0039] Furthermore, since the light-shielding member of the present invention comprises the resin molded body described above, it can stably suppress light reflection.

[0040] Figure 1 is a perspective view of a resin molded body as one embodiment of the present invention. Figure 2 is a plan view of the resin molded body shown in Figure 1. Figure 3 is a cross-sectional view taken along line A-A of the resin molded body shown in Figure 2. Figure 4 is a cross-sectional view of a light-shielding member as one embodiment of the present invention. Figures 5A to 5C are process diagrams showing a method for manufacturing the resin molded body shown in Figure 1, where Figure 5A shows the coating process, Figure 5B shows the exposure process, and Figure 5C shows the development process. Figure 6 is a plan view of the photomask shown in Figure 5.

[0041] 1. Resin Molded Body First, a resin molded body 1, which is one embodiment of the resin molded body of the present invention, will be described. The resin molded body 1 is for use in a light-shielding component 10 (see Figure 4), which will be described later.

[0042] As shown in Figure 1, the resin molded body 1 is, for example, a sheet. The resin molded body 1 may also be a plate or a film. The resin molded body 1 is a cured product of a photosensitive resin. Examples of photosensitive resins include photosensitive polyimide. The resin molded body 1 may contain a black dye.

[0043] Examples of black pigments include black pigments and black dyes. Examples of black pigments include carbon black and titanium-based pigments. Examples of black dyes include mixtures of dyes such as phthalocyanine blue, phthalocyanine green, monoazo yellow, disazo yellow, benzimidazolon yellow, quinacridone red, monoazo red, boriazo red, and beryllene red. More preferably, black pigments are used as black pigments, and even more preferably, carbon black is used.

[0044] The resin molded body 1 has a surface S1 and a surface S2 in the thickness direction of the resin molded body 1. The surface S1 is one side surface of the resin molded body 1 in the thickness direction. The surface S2 is the other side surface of the resin molded body 1 in the thickness direction. The resin molded body 1 has a base 2 and a plurality of protrusions 3.

[0045] The base 2 supports the plurality of protrusions 3. The base 2 extends in a direction orthogonal to the thickness direction. The base 2 has, for example, a sheet shape. The thickness of the base 2 is not limited.

[0046] The plurality of protrusions 3 are arranged on the surface S1. In other words, the resin molded body 1 has the plurality of protrusions 3 on the surface S1. The plurality of protrusions 3 are arranged on one side of the base 2 in the thickness direction. The plurality of protrusions 3 are arranged at intervals from each other. The plurality of protrusions 3 may be arranged periodically or randomly. Each of the plurality of protrusions 3 protrudes from the base 2 to one side in the thickness direction. Each of the plurality of protrusions 3 has a tip 3A and a base end 3B in the thickness direction. The tip 3A is one end portion of the protrusion 3 in the thickness direction. The tip 3A is arranged away from the base 2 in the thickness direction. The base end 3B is the other end portion of the protrusion 3 in the thickness direction. The base end 3B is continuous with the base 2.

[0047] As shown in FIG. 2, the protrusion 3 has a circular shape when viewed from the thickness direction. The diameter R1 of the protrusion 3 is 3 μm or more, preferably 5 μm or more, more preferably 7 μm or more. When the diameter R1 of the protrusion 3 is equal to or greater than the above lower limit value, the reflection of light on the surface S1 can be suppressed. The reflection of light on the surface S1 can be evaluated by the specular reflectance described later. The diameter R1 of the protrusion 3 is, for example, 100 μm or less, preferably 70 μm or less, more preferably 50 μm or less. The diameter R1 of the protrusion 3 may be 3 μm to 100 μm, 5 μm to 70 μm, or 7 μm to 50 μm. The diameter R1 of the protrusion 3 is the diameter of the thickest part of the protrusion 3. In the present embodiment, the diameter R1 of the protrusion 3 is the diameter of the base end 3B of the protrusion 3.

[0048] The interval D1 between each of the plurality of protrusions 3 is, for example, 0.5 μm or more, preferably 5 μm or more, more preferably 10 μm or more, still more preferably 20 μm or more. When the interval D1 is not less than the above lower limit value, it is possible to suppress the overlapping of the protrusions 3. As a result, the height difference of the surface S1 becomes large, and the specular reflectance can be lowered. The interval D1 is, for example, 50 μm or less, preferably 30 μm or less. The interval D1 may be 0.5 μm to 50 μm, 5 μm to 50 μm, 10 μm to 50 μm, 20 μm to 50 μm, or 20 μm to 30 μm. Here, the interval D1 between the protrusions means the distance between the bases of adjacent protrusions (see FIG. 2 for details).

[0049] As shown in FIG. 3, the protrusion 3 has a tapered shape that becomes thinner from the base end 3B toward the tip end 3A. The height H of the protrusion 3 is, for example, 0.5 μm or more, preferably 1.0 μm or more. The height H of the protrusion 3 is, for example, 30 μm or less, preferably 25 μm or less. The height H of the protrusion 3 is 0.5 μm to 30 μm, or 1.0 μm to 25 μm.

[0050] The specular reflectance of the surface S1 is, for example, 7.0% or less, preferably 5.0% or less, more preferably 3.0% or less, still more preferably 2.0%, still more preferably 1.5% or less, still more preferably 1.0% or less, still more preferably 0.5% or less, still more preferably 0.1% or less, still more preferably 0.07% or less. The specular reflectance of the surface S1 may be 0%. The specular reflectance of the surface S1 is, for example, 0.01% or more. The specular reflectance of the surface S1 may be 0% to 7.0%, 0.01% to 7.0%, 0.01% to 5.0%, 0.01% to 3.0%, 0.01% to 2.0%, 0.01% to 1.5%, 0.01% to 1.0%, 0.01% to 0.5%, 0.01% to 0.1%, or 0.01% to 0.07%.

[0051] The specular reflectance of the surface S1 is measured by the method described in the examples described below.

[0052] 2. Light-shielding component Next, the light-shielding component 10 as an embodiment of the light-shielding component of the present invention will be described.

[0053] As shown in Figure 4, the light-shielding component 10 comprises, for example, a support layer 11, the resin molded body 1 described above, and a covering layer 12.

[0054] (1) Support layer The support layer 11 is positioned on the other side of the resin molded body 1 in the thickness direction. The support layer 11 is positioned on the opposite side of the projection 3 from the base 2 in the thickness direction. The support layer 11 supports the resin molded body 1. The support layer 11 improves the rigidity of the light-shielding component 10. The support layer 11 has, for example, a flat plate shape. The support layer 11 is made of metal. Examples of materials for the support layer 11 include copper, copper alloy, stainless steel, aluminum, titanium, nickel, tantalum, and magnesium. Preferably, the materials for the support layer 11 include copper and stainless steel.

[0055] (2) Resin molded body The resin molded body 1 is positioned on one side of the support layer 11 in the thickness direction. The resin molded body 1 is positioned on one side surface of the support layer 11 in the thickness direction. The resin molded body 1 covers one side surface of the support layer 11 in the thickness direction. The resin molded body 1 covers the entire one side surface of the support layer 11 in the thickness direction.

[0056] (3) Coating layer The coating layer 12 covers the surface S1 of the resin molded body 1. Specifically, the coating layer 12 covers one side surface of the base 2 in the thickness direction and each surface of the plurality of protrusions 3. The color of the coating layer 12 is black. The coating layer 12 is made of, for example, a metal oxide. The coating layer 12 may have a plurality of layers. The coating layer 12 may have a plurality of layers made of metal oxide. If the coating layer 12 has a plurality of layers, the color of the coating layer 12 may be achieved by superimposing the colors of each layer constituting the coating layer 12.

[0057] Examples of metal oxides include chromium oxide, silicon dioxide, titanium oxide, niobium oxide, and aluminum oxide.

[0058] The thickness T of the coating layer 12 is thinner than the height H of the protrusion 3. The thickness T of the coating layer 12 is, for example, 1000 nm or less, preferably 750 nm or less. The thickness T of the coating layer 12 is, for example, 30 nm or more, preferably 50 nm or more.

[0059] 3. Method for Manufacturing a Resin Molded Article Next, an embodiment of the method for manufacturing a resin molded article according to the present invention will be described.

[0060] As shown in Figures 5A to 5C, the method for manufacturing a resin molded article includes, for example, a coating step (see Figure 5A), an exposure step (see Figure 5B), and a development step (see Figure 5C).

[0061] (1) Coating process As shown in Figure 5A, in the coating process, a photosensitive resin solution (varnish) is applied to one side surface of the substrate S in the thickness direction and dried to form a layer F made of photosensitive resin on the substrate S. The substrate S may be the support layer 11 described above.

[0062] (2) Exposure process As shown in Figure 5B, in the exposure process, the portion of layer F made of photosensitive resin in which the "protrusions 3 are formed" is exposed. For example, in the exposure process, layer F is exposed in gradation through a photomask M. Alternatively, layer F may be exposed using direct imaging exposure without using a photomask M.

[0063] As shown in Figure 6, the photomask M has a transparent portion M1 and a semi-transparent portion M2.

[0064] The transparent portion M1 transmits light. The transparent portion M1 includes a dot pattern DP. In other words, the photomask M includes a dot pattern DP. The dot pattern DP consists of a plurality of dots D. The plurality of dots D are spaced apart from each other. The plurality of dots D may be arranged periodically or randomly. In the exposure process, the portion of the photosensitive resin layer F in which the protrusions 3 are formed is exposed by light transmitted through the dot pattern DP.

[0065] The dot D has a circular shape when viewed from the thickness direction. The diameter R2 of the dot D is set so that the desired protrusion 3 is obtained. The diameter R2 of the dot D is, for example, 3 μm or more, preferably 5 μm or more, more preferably 7 μm or more. The diameter R2 of the dot D is, for example, 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. The diameter R2 of the dot D may be 3 μm to 50 μm, 5 μm to 40 μm, 7 μm to 30 μm, or 7 μm to 20 μm.

[0066] The spacing D2 between each of the multiple dots D is, for example, 0.5 μm or more, preferably 2 μm or more. If the spacing D2 is greater than or equal to the lower limit value above, the height H of the protrusions 3 can be secured, and the reflection of light on the surface S1 of the obtained resin molded body 1 can be further suppressed. The spacing D2 is, for example, 50 μm or less, preferably 30 μm or less, more preferably 20 μm or less, more preferably 10 μm or less, more preferably less than 5 μm, and more preferably 3 μm or less. The spacing D2 may be 0.5 μm to 50 μm, 0.5 μm to 30 μm, 0.5 μm to 20 μm, 0.5 μm to 10 μm, 0.5 μm to 5 μm, 0.5 μm to 3 μm, or 2 μm to 3 μm.

[0067] The semi-transparent portion M2 transmits less light than the transparent portion M1. The light transmitted through the semi-transparent portion M2 exposes the portion of the photosensitive resin layer F where the base 2 is formed.

[0068] (3) Development process In the development process, the exposed layer F is developed to form a plurality of protrusions 3 on the surface of layer F. For example, a developer is sprayed onto the exposed layer F. As a result, a portion of the exposed layer F in which the "base 2 is formed" is removed, and a plurality of protrusions 3 are formed on the surface of layer F. Here, the lower limit of the development time can be, for example, 3 minutes or more, 6 minutes or more, and 8 minutes or more. The upper limit of the development time can be, for example, 20 minutes or less, 15 minutes or less, and 11 minutes or less. The development time may be 3 to 20 minutes, 6 to 15 minutes, or 8 to 11 minutes.

[0069] As a result, the above-described resin molded body 1 is obtained.

[0070] 4. Effects (1) According to the method for manufacturing a resin molded body, as shown in Figures 5A to 5C, a resin molded body 1 for light-shielding parts having a plurality of protrusions 3 on its surface is manufactured by photolithography including an exposure step (see Figure 5B) and a development step (see Figure 5C).

[0071] Therefore, the protrusion 3 can be positioned at the desired location and with the desired shape, and variations in the position and shape of the protrusion 3 from product to product can be suppressed.

[0072] As a result, a stable matte finish can be imparted to the light-shielding component 10 (see Figure 4) using the obtained resin molded body 1.

[0073] Furthermore, the outer shape of the resin molded body 1 can be patterned along with the formation of the protrusions 3 in a single exposure and development process.

[0074] Therefore, it is possible to suppress the increase in man-hours.

[0075] Furthermore, since external processing of the resin molded body 1 is not required, the occurrence of dimensional errors in the external processing of the resin molded body 1 can be suppressed.

[0076] As a result, the dimensional accuracy of the light-shielding component 10 can be improved.

[0077] (2) According to the method for manufacturing a resin molded article, as shown in Figure 5B, in the exposure step, a layer F made of photosensitive resin is subjected to gradation exposure through a photomask M that includes a dot pattern DP consisting of a plurality of dots D.

[0078] Therefore, a simple process of performing gradation exposure via a photomask M allows for the placement of protrusions 3 of the desired shape at the desired position.

[0079] (3) According to the method for manufacturing a resin molded article, the diameter R2 of the dot D of the photomask M (see Figure 6) is 3 μm or more.

[0080] Therefore, the diameter R1 (see Figure 2) of the protrusion 3 on the surface S1 of the obtained resin molded body 1 can be secured.

[0081] This makes it possible to suppress the reflection of light on the surface S1 of the resulting resin molded body 1.

[0082] As a result, the matte finish of the light-shielding component 10 using the obtained resin molded body 1 can be improved.

[0083] (4) According to the method for manufacturing a resin molded article, the spacing D2 (see Figure 6) between each of the multiple dots D is 0.5 μm or more.

[0084] Therefore, the height H (see Figure 3) of the protrusion 3 on the surface S1 of the obtained resin molded body 1 can be ensured.

[0085] This makes it possible to suppress the reflection of light on the surface S1 of the resulting resin molded body 1.

[0086] As a result, the matte finish of the light-shielding component 10 using the obtained resin molded body 1 can be improved.

[0087] (5) The resin molded body 1 is for light-shielding parts and has a plurality of protrusions 3 on its surface S1 as shown in Figure 1. The diameter R1 of the protrusions 3 (see Figure 2) is 3 μm or more.

[0088] Therefore, the reflection of light on the surface S1 of the resin molded body 1 can be suppressed.

[0089] As a result, the matte finish of the light-shielding component 10 using the resin molded body 1 can be improved.

[0090] (6) In the resin molded body 1, the height H of the protrusion 3 (see Figure 3) is 0.5 μm or more.

[0091] Therefore, the reflection of light on the surface S1 of the resin molded body 1 can be further suppressed.

[0092] As a result, the matte finish of the light-shielding component 10 using the resin molded body 1 can be improved.

[0093] (7) According to the resin molded body 1, the specular reflectance of the surface S1 is 7% or less.

[0094] Therefore, the reflection of light on the surface S1 of the resin molded body 1 can be reliably suppressed.

[0095] As a result, it is possible to reliably improve the matte finish of the light-shielding component 10 using the resin molded body 1.

[0096] (8) The light-shielding component 10 comprises the resin molded body 1 described above, as shown in Figure 4.

[0097] Therefore, it can reliably suppress light reflection.

[0098] (9) The light-shielding component 10 further comprises a support layer 11 that supports the resin molded body 1, as shown in Figure 4.

[0099] Therefore, the support layer 11 ensures the rigidity of the light-shielding component 10.

[0100] 5. Modified Examples Next, modified examples will be described. In the modified examples, the same reference numerals are used for components similar to those in the embodiments described above, and their descriptions are omitted.

[0101] (1) The light-shielding component 10 does not need to have a support layer 11. The light-shielding component 10 may consist only of a resin molded body 1 and a coating layer 12.

[0102] (2) If the resin molded body 1 contains a black pigment, the light-shielding component 10 does not need to have a coating layer 12. The light-shielding component 10 may consist only of the resin molded body 1 containing the black pigment and the support layer 11, or it may consist only of the resin molded body 1 containing the black pigment.

[0103] (3) In the method for manufacturing a resin molded article, instead of the coating step, a lamination step may be performed in which a photosensitive resin film is laminated onto the substrate S.

[0104] (4) The same effects and advantages as those of the embodiments described above can be obtained in the above modifications (1) to (3).

[0105] The present invention will be further described below with reference to examples and comparative examples. However, the present invention is not limited in any way to the examples and comparative examples. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical properties, and parameters used in the following description may be replaced with the upper limits (numbers defined as "less than or equal to" or "less than") or lower limits (numbers defined as "greater than or equal to" or "greater than") of the corresponding blending ratios (content ratios), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0106] 1. Manufacturing of resin molded products: A photosensitive polyimide solution (varnish) was applied to one surface of a stainless steel substrate and dried to form a layer made of photosensitive polyimide on the substrate.

[0107] Next, a layer made of photosensitive polyimide was subjected to gradation exposure (exposure step) through a photomask having a dot pattern, and then developed (development step) to obtain a resin molded body having multiple protrusions. For Examples 1 to 6, the development time was set to 4 minutes. For Examples 7 to 14, the development time was adjusted between 5 and 15 minutes to achieve the lowest specular reflectance.

[0108] Tables 1 and 2 show the dot diameters and dot spacings of the photomasks used in each embodiment.

[0109] 2. Measurement of Specular Reflectance The specular reflectance of the surface (surface with protrusions) of the resin molded articles obtained in each example was measured using a spectrophotometer (product name "U-4100", manufactured by Hitachi, Ltd.) under conditions of a wavelength of 550 nm and an incident angle of 5°. The results are shown in Tables 1 and 2.

[0110]

[0111] 1. Resin molded body S1. Surface of the resin molded body 3. Protrusion D1. Spacing between protrusions R1. Diameter of the protrusion 10. Light-shielding component 11. Support layer 12. Coating layer F. Layer made of photosensitive resin M. Photomask DP. Dot pattern D. Dot D2. Spacing between dots R2. Diameter of the dots

Claims

1. A method for manufacturing a resin molded article, wherein the resin molded article is for use as a light-shielding component and has a plurality of protrusions on its surface, and the method for manufacturing the resin molded article comprises: an exposure step of exposing a portion of a layer made of photosensitive resin on which the protrusions are formed, and a developing step of developing the exposed layer to form the protrusions on the surface of the layer.

2. The method for manufacturing a resin molded article according to claim 1, wherein in the exposure step, the layer is subjected to gradation exposure through a photomask that includes a dot pattern consisting of a plurality of dots.

3. The method for manufacturing a resin molded article according to claim 2, wherein the diameter of the dots is 3 μm or more.

4. The method for manufacturing a resin molded article according to claim 2, wherein the spacing between each of the multiple dots is 0.5 μm or more.

5. A resin molded body for use as a light-shielding component, having multiple protrusions on its surface, wherein the diameter of the protrusions is 3 μm or more.

6. The resin molded article according to claim 5, wherein the height of the protrusion is 0.5 μm or more.

7. The resin molded article according to claim 5, wherein the spacing between each of the multiple protrusions is 0.5 μm or more.

8. The resin molded article according to claim 5, which contains a black pigment.

9. The resin molded article according to claim 5, wherein the specular reflectance of the surface is 7.0% or less.

10. A light-shielding component comprising a resin molded body according to any one of claims 5 to 9.

11. The light-shielding component according to claim 10, further comprising a support layer for supporting the resin molded body.

12. The light-shielding component according to claim 10, further comprising a coating layer that covers the surface of the resin molded body.

13. The light-shielding component according to claim 12, wherein the coating layer is made of a metal oxide.

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