Resin molding mold

Abstract

A resin molding mold (10) for use in molding a resin-molded glossy embossed product, comprising: a molding die (12) having an embossing-forming convex portion (14a) and an embossing-forming concave portion (14b) on a molding surface (12a) thereof, and a mirror surface coating layer (16) formed on a surface of the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b) formed on the molding surface (12a) of the molding die (12), wherein the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b) each have a flat surface, wherein an inclined surface is arranged between the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b), wherein the height (T) between the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b) is set to 10 µm or more, wherein the thickness of the mirror surface coating layer (16) is smaller than the height (T) between the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b), wherein the mirror surface coating layer (16) is cured at a temperature in a range of 100°C or more to 150°C or less and is formed by a thermosetting resin having a thermal conductivity in a range of 0.10 W / (mK) or more to 0.99 W / (mK) or less, the mirror surface coating layer (16) has a thickness in a range of 1.0 µm or more to 20 µm or less to prevent a disturbance due to waviness on the surface of the mirror surface coating layer (16), and the mirror surface coating layer (16) has a flat surface such that a gloss surface of the mirror surface coating layer (16) measured by a 60° gloss meter has a gloss value of 15.4 or more to 59.4 or less.

Description

Field of the invention

[0001] This invention relates to a resin molding mold, and more particularly, to a resin molding mold for molding a resin molded product, which has a high luster on the product surface of the resin molded product and also enables a high-quality impression. Background of the invention

[0002] For example, conventionally, resin-molded products used as interior parts for vehicles, particularly instrument panels, ornaments, etc., arranged around windows, require a high-quality impression. Such a resin-molded product is formed by preparing a molding die, performing a surface treatment called an embossing process, and using the molding die. Thus, a very small pattern of concave-convex portions, called embossing, is formed on the surface of the resin-molded product.

[0003] The purpose of forming such embossing is to impart a high-quality impression from a design perspective by adding subtle shadows or appropriate luster and tactile impression to the surface of a resin-molded product. On the other hand, embossing also has practical purposes, such as making imperfect external appearances, such as weld lines, irregularities, and the like, which typically appear on the product surface in the case of injection molding using plastic materials, less noticeable, and also preventing scratches from occurring on the product surface or making them less noticeable.

[0004] In this case, for example, as described in Patent Document 1, an embossed product molding die was disclosed. In the case where an embossment is formed on an injection mold for an embossed product having a complicated concave-convex pattern, that is, a so-called satin embossed pattern, on a metal mold surface, the concave-convex portions formed by performing an etching process on a flat metal mold surface without concave-convex portions are formed to have concave-convex pitches in a range of 0.3 to 0.5 mm, to which a beam projection material is readily deposited in a blasting process described later to adjust the ten-point average roughness (Rz) of the concave-convex portions in a range of 20 to 40 μm.and thereafter, by performing a shot blasting treatment on the concave-convex surface using a spherical-state beam projection material under conditions of a particle size of 100 to 200 meshes and a pneumatic compression pressure of 0.2 to 0.4 MPa at the time of blasting, corrosion irregularities due to etching and undercuts due to corrosion remaining on the surface of embossed concave-convex portions are uniformly adjusted, and as a finishing treatment, by applying a spherical-state beam projection treatment with a particle size of 100 to 200 meshes, which is selected to sufficiently penetrate into the embossed concave-convex spaces and enable the beam traces of the beam projection material to be neither too fine nor too rough, under a pneumatic compression pressure lower than that of the above-mentioned blasting treatment by the spherical-state beam projection material,and higher than 0.2 MPa, fine residues of the concave-convex portions remaining in the inner depths of the concave portions of the embossed concave-convex portions are eliminated, and burrs caused by the beam traces of the beam projection material in the spherical state itself are flattened, so that the smooth surface of embossed concave-convex portions is formed, which has only the traces of the beam projection material in the spherical state. Thus, the above-mentioned patent document has disclosed an embossed product molding mold that can produce an embossed product with a high luster and a high-quality impression, which makes defective external appearances, such as weld lines, irregularities, and the like, less conspicuous, and also has excellent scratch-resistant properties. Prior art documentsPatent document

[0005] Patent Document 1: JPH 11-320627 A

[0006] DE 692 23 763 T2 discloses a mold for molding synthetic resin, which mold comprises a molded body made of a metal, wherein the mold is provided with a polyimide layer on the wall of its cavity,

[0007] JP 2001-62 843 A discloses a mold having a resin layer on a heat-insulating layer and a polymer layer on the resin layer.

[0008] JP 2003-39440 A discloses a mold having a surface with an uneven pattern. This surface is coated with a synthetic resin. Brief description of the inventionProblems to be solved by the invention

[0009] However, since adjustments between the concave-convex pitches are required for an embossing process on the surface of the molding die, and since a plurality of blasting processes are required after the embossing process on the surface of the molding die, as described in the case of Patent Document 1 above, numerous processes are required. Furthermore, it is considered difficult to uniformly perform these numerous processes on the entire embossing process surface.

[0010] Therefore, it is an object of the present invention to provide a resin molding mold that can produce a gloss on a resin-molded product surface comparatively easily even in the case where it is applied to a resin molding mold having concave-convex portions by an embossing process, and can obtain a resin-molded product with an improved texture by creating a high luster.

[0011] The present invention provides a resin molding mold for use in molding a resin-molded glossy embossed product, comprising: a molding mold having an embossing-forming convex portion and an embossing-forming concave portion on a molding surface thereof; and a mirror-surface coating layer formed on a surface of the embossing-forming convex portion and the embossing-forming concave portion formed on the molding surface of the molding mold. The embossing-forming convex portion and the embossing-forming concave portion each have a flat surface, and an inclined surface is disposed between the embossing-forming convex portion and the embossing concave portion. The height between the embossing-forming convex portion and the embossing concave portion is set to 10 µm or more.The thickness of the mirror surface coating layer is smaller than the height between the embossing-forming convex portion and the embossing-forming concave portion. The mirror surface coating layer is cured at a temperature in a range of 100°C or more to 150°C or less and is formed by a thermosetting resin having a thermal conductivity in a range of 0.10 W / (mK) or more to 0.99 W / (mK) or less. The mirror surface coating layer has a thickness in a range of 1.0 μm or more to 20 μm or less to prevent distortion due to waviness on the surface of the mirror surface coating layer, and the mirror surface coating layer has a flat surface such that a gloss surface of the mirror surface coating layer has a gloss value of 15.4 or more to 59.4 or less as measured by a 60° glossmeter.

[0012] According to the resin molding die of the invention, since the surface of the mirror surface coating layer has the flat surface maintaining part formed as a substantially flat surface, and since the thickness of the mirror surface coating layer is set in a range of 1.0 μm or more to 20 μm or less, it is possible to prevent scratches (fretting wear) due to protrusions on the inner surface of the molding die relative to the drawing direction and scratches caused by stress or friction applied to the resin molded product with an embossing due to resin contraction thereof at the time of a curing process from occurring on the resin molded product at the time of drawing the resin molded product from the resin molding die.

[0013] In addition, since the thickness of the mirror surface coating layer is set in a range of 1.0 μm or more to 20 μm or less, it is possible to avoid trouble due to wave formation on the surface of the mirror surface coating layer that occurs at the time of evaporation of a solvent component contained in a mixed solution used in forming the mirror surface coating layer.

[0014] Further, since the thickness of the mirror surface coating layer is set in a range of 1.0 µm or more to 20 µm or less, it is possible to prevent liquid dripping at the time when a mixed solution is applied to the molding surface 12a of the molding die 12 having concave-convex portions formed thereon by an embossing process to form the mirror surface coating layer 16.

[0015] Since the thickness of the mirror surface coating layer is set in a range of 1.0 µm or more to 20 µm or less, the layer becomes resistant to a number of injection molding processes for resin-molded products.

[0016] As described above, since the flat surface maintaining part of the mirror surface coating layer of the resin molding mold can ensure a stable flat surface state, it becomes possible to prevent a defective external appearance from occurring on the product surface of a resin molded product when an injection molding process is carried out using this resin molding mold, thereby making it possible to obtain a resin molded product with an improved texture by providing a high gloss.

[0017] In addition, since the thickness of the mirror surface coating layer is set to 20 μm or less, it becomes possible to more effectively avoid a disturbance due to wave formation on the surface of the flat surface maintaining part of the mirror surface coating layer, which occurs at the time of evaporation of a solvent component contained in a mixed solution used in forming the mirror surface coating layer. Effects of the invention

[0018] According to the present invention, it is possible to provide a resin molding mold that can comparatively easily produce a gloss on the product surface of a resin-molded product even in the case where the resin molding mold having concavo-convex portions formed by embossing is used, and to obtain a resin-molded product having an improved texture by providing a high luster.

[0019] These and other objects, features and advantages of the present invention will become apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings. Short description of the drawings Fig. 1 is a cross-sectional view showing an example of a resin molding die according to the present invention. Fig. 2 is an enlarged cross-sectional view in which a portion corresponding to a mirror surface coating layer of the Fig. 1 shown resin molding mold. Fig. 3 is a cross-sectional view showing a state in which a resin molded product injection-molded using the resin molding mold according to the invention is drawn therefrom. Fig. 4 is a 4(a) and Fig.4(b) shows an external appearance of a test plate of a resin molded product used in an experiment; Fig. 4(a) is a front view, and Fig. 4(b) is a side view. Detailed Description of the Invention 1. Resin molding mold

[0020] Fig. 1 is a cross-sectional view showing an example of a resin molding mold according to the present invention, and Fig. 2 is an enlarged cross-sectional view in which a portion corresponding to a mirror surface coating layer of the Fig. 1 shown resin molding mold. Fig. 3 is a cross-sectional view showing a state in which a resin molded product injection-molded using the resin molding mold according to the invention is drawn therefrom.

[0021] A resin molding mold 10 includes a molding mold 12.

[0022] The molding die 12 may be made of a material that can be heated to at least 150°C, and is formed, for example, using a metal material such as iron steel, aluminum, ZAS, or the like, or a synthetic resin material. The molding surface 12a of the molding die 12 is subjected to an embossing process, for example, by etching, resulting in the formation of an embossing convex portion 14a and an embossing concave portion 14b. The maximum height T between the embossing convex portion 14a and the embossing concave portion 14b obtained by the embossing process is preferably set to 10 µm or more. If it is less than 10 µm, a portion of the embossing concave portion 14b is undesirably buried by a mirror surface coating layer 16, which will be described later.

[0023] Furthermore, a drawing gradient for use in injection molding is formed in the molding die 12. This drawing gradient is specified with respect to the maximum height T between the embossing-forming convex portion 14a and the embossing-forming concave portion 14b formed by the embossing process, and is set to approximately 1 degree, for example, when the maximum height T between the embossing-forming convex portion 14a and the embossing-forming concave portion 14b is 10 μm.

[0024] The embossing method is a method for forming a concave-convex pattern, such as leather embossing, geometric embossing, satin embossing, or the like. The embossing pattern includes a leather embossing pattern, a skin texture pattern, a wood grain pattern, a satin pattern, a leaf vein pattern, a scale pattern, a marble pattern, a hairline pattern, a geometric pattern, a polishing pattern, a coating pattern, or the like.

[0025] In addition, the embossing process may form a concave-convex shaped pattern using a method other than etching, and the pattern may be formed by, for example, carving, a machining process, or polishing lines.

[0026] Furthermore, in the embossing process, a concave-convex shaped pattern may be partially formed by the molding surface 12a of the molding die 12. In this case, the molding surface 12a of the molding die 12 is formed as a mirror surface without an embossment formed thereon.

[0027] Furthermore, the embossing process is not necessarily performed on the entire surface of the molding surface 12a of the molding die 12. In this case, the entire surface of the molding surface 12a of the molding die 12 is formed as a mirror surface without embossing formed thereon.

[0028] The resin molding mold 10 includes the mirror surface coating layer 16 formed on the entire surface of the molding surface 12a of the molding mold 12. In addition, the mirror surface coating layer 16 may be formed only on a portion of the molding surface 12a of the molding mold 12. Moreover, the surface of the mirror surface coating layer 16 includes a flat surface maintaining part 18 formed as a substantially flat surface.

[0029] The mirror surface coating layer 16 includes at least one thermosetting resin. The mirror surface coating layer 16 is formed to have a thickness in a range of 1.0 μm or more to 20 μm or less. When the thickness of the mirror surface coating layer 16 exceeds 20 μm, rippling occurs on the surface of the mirror surface coating layer 16, and when it exceeds 30 μm, the rippling appears more prominently on the surface of the mirror surface coating layer 16, making it difficult to produce a gloss with a high texture on the product surface of the resin-molded product. Further, the thickness of the mirror surface coating layer 16 is smaller than at least the maximum height T between the embossing-forming convex portion 14a and the embossing-forming concave portion 14b formed by the embossing process.In the case where the thickness of the mirror surface coating layer 16 is greater than the maximum thickness T between the embossing-forming convex portion 14a and the embossing-forming concave portion 14b formed by the embossing process, the embossing process is no longer performed on the resin-molded product because the concave-convex portions formed by the embossing are buried. This mirror surface coating layer 16 may be formed on both the core mold and the cavity mold, or the mirror surface coating layer 16 may be formed only on the cavity mold.

[0030] In addition, the thickness of the mirror surface coating layer 16 can be measured, for example, by an electromagnetic eddy current film thickness gauge (manufactured by Sanko Electronic Laboratory Co., Ltd., Model No.: SWT-9100).

[0031] Regarding the thermosetting resin to be used for the mirror surface coating layer 16, heat resistance, mold release property, adhesiveness to the molding surface 12a of the molding die 12, wear resistance, etc. are necessary. Regarding heat resistance, those that do not melt at a temperature lower than 100°C are preferably used, and the curing temperature of the thermosetting resin is adjusted according to the heat resistance temperature of the molding die 12. In the case where the mirror surface coating layer 16 is formed on a molding die 12 made of a material with a low melting point such as aluminum, ZAS, or the like, for example, a thermosetting resin that is cured at a temperature range of 100°C or more to 150°C or less is used according to the heat resistance temperature of the molding material.In terms of wear resistance, those that have sufficient wear resistance with respect to the flow of molten substances of the resin at the time of injection molding are preferably used. For example, in the case of a molding process using a synthetic resin, for example, at the time of injection molding, those materials that are durable with respect to molding processes of 1,000 injections or more are preferably used. This is because, in the molding of resin-molded products, a large number of resin-molded products are molded using the same molding die 12.Since the thickness of the mirror surface coating layer 16 is set in a range of 1.0 µm or more to 20 µm or less as described above, the resulting mold can be durable with respect to a larger number of molding processes of resin-molded products.

[0032] In addition, to meet the above-mentioned requirements for the mirror surface coating layer 16, materials having high thermal insulation properties are used as the thermosetting resin to be used for the mirror surface coating layer 16. For example, a thermosetting resin with a thermal conductivity in a range of 0.10 W / (mK) or more to 0.99 W / (mK) or less is used as the thermosetting resin to be used for the mirror surface coating layer 16.

[0033] As the thermosetting resin to be used for the mirror surface coating layer 16, a phenol resin, an alkyd resin, a melamine urea resin, an epoxy resin, a polyurethane resin, a silicone resin, a chloride rubber-based resin, a vinyl acetate resin, an acrylic resin, a vinyl chloride resin, a fluororesin, cellulose, a polystyrene resin, or the like can be used, and either a single substance or a copolymer can be used. 2. Manufacturing process of a resin mold

[0034] The following description discusses a manufacturing method of a resin molding mold according to the present invention.

[0035] First, a molding die 12 subjected to an embossing process is prepared. Through this embossing process, an embossing-forming convex portion 14a and an embossing-forming concave portion 14b are formed on a molding surface 12a of the molding die 12.

[0036] As a base material of the molding die 12, a material that can be heated to at least 150°C can be used, and for example, a metal material such as iron steel material, aluminum, ZAS or the like, and a synthetic resin material can be used.

[0037] Furthermore, an embossing process for forming a concave-convex pattern, such as leather embossing, geometric embossing, satin embossing, or the like, is optionally performed on the molding surface 12a of the molding mold 12. The embossing pattern is selected from the group consisting of a leather embossing pattern, a skin texture pattern, a wood grain pattern, a satin pattern, a leaf vein pattern, a scale pattern, a marble pattern, a hairline pattern, a geometric pattern, a polishing pattern, a coating pattern, or the like. On the other hand, sometimes no embossing process is performed on the molding surface 12a of the molding mold 12.

[0038] Further, the molding surface 12a of the molding mold 12 is degreased and washed to form a mirror surface coating layer 16 in a process to be carried out later.

[0039] Next, the mirror surface coating layer 16 is formed on the molding surface 12a of the molding die 12. To form the mirror surface coating layer 16, a thermosetting resin is first prepared. Then, a mixed solution formed by dispersing the thus prepared thermosetting resin in a solvent is prepared.

[0040] With respect to the thermosetting resin to be used for forming the mirror surface coating layer 16, a phenol resin, an alkyd resin, a melamine urea resin, an epoxy resin, a polyurethane resin, a silicone resin, a chloride rubber-based resin, a vinyl acetate resin, an acrylic resin, a vinyl chloride resin, a fluororesin, cellulose, a polystyrene resin, or the like can be used, and either a single substance or a copolymer can be used.

[0041] As a solvent to be used for forming the mirror surface coating layer 16, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, n-butyl acetate, n-butyl alcohol, methyl alcohol, and ethylene glycol monomethyl ether acetate can be used. In the mixed solution used to form the mirror surface coating layer 16, the dilution rate of the solvent is further adjusted from 5% or more to 20% or less.

[0042] Thereafter, in order to form the mirror surface coating layer 16, the thus prepared mixture is applied to the molding surface 12a of the molding die 12 using, for example, a spraying method to have a thickness in a range of 1.0 µm or more to 20 µm or less.

[0043] The spraying conditions of the mixed solution for forming the mirror surface coating layer 16 are set such that, for example, a coating pressure (pneumatic pressure) is 0.25 MPa, the diameter of a spray gun is 0.8 mm, and a coating distance is in a range of 15 cm or more to 40 cm or less. Furthermore, the spraying process is performed in a direction as vertical as possible relative to the mold surface 12a of the molding die 12 to be coated. This arrangement is selected to enable the mirror surface coating layer 16 to be uniformly applied to the mold surface 12a of the molding die 12. The location where the coating is performed is, for example, a coating room.

[0044] In addition, the mirror surface coating layer 16 may be formed not on the entire surface of the molding surface 12a of the molding mold 12, but also on a partial portion thereof.

[0045] Thereafter, the molding mold 12 coated with the mixed solution is baked at a baking temperature of 100°C or more to 150°C or less for 2 hours or more to 5 hours or less, so that the mirror surface coating layer 16 is formed on the molding surface 12a of the molding mold 12; thus, a resin molding mold 10 is obtained. 3. Resin molded product

[0046] Using the resin molding mold 10, an injection molding process is performed using a heated and melted thermosetting resin. The materials of the thermoplastic resin to be molded using the present resin molding mold 10 include, for example, polypropylene (PP), an ABS resin that is a synthetic copolymer resin of acrylonitrile, butadiene, and styrene, polyvinyl chloride (PVC), and so on. Furthermore, with respect to the thickness of the resin-molded product, which is not specifically limited, molded products with a desired thickness can be manufactured.

[0047] A product surface 110 of the resin molded product 100 of Fig. 3, which is molded using the resin molding mold 10, has sufficient gloss with a high luster.

[0048] Since the thickness of the mirror surface coating layer 16 is set in a range of 1.0 µm or more to 20 µm or less, according to the resin molding mold 10 of Fig. 1, it is possible to prevent scratches (fretting wear) due to protrusions on the inner surface of the molding die relative to the drawing direction and scratches caused by stress or friction applied to the resin molded product 100 having an embossing due to resin contraction thereof at the time of a curing process from occurring on the resin molded product 100 at the time of drawing the resin molded product 100 from the resin molding die 10.

[0049] Moreover, since the thickness of the mirror surface coating layer 16 is set in a range of 1.0 µm or more to 20 µm or less, it is possible to avoid trouble due to waviness on the flat surface maintaining member 18 that occurs at the time of evaporation of a solvent component when the mirror surface coating layer 16 is formed.

[0050] Further, since the thickness of the mirror surface coating layer 16 is set in a range of 1.0 µm or more to 20 µm or less, it is possible to prevent liquid dripping at the time when a mixed solution is applied to the molding surface 12a of the molding die 12 having concave-convex portions formed thereon by an embossing process to form the mirror surface coating layer 16.

[0051] Since the thickness of the mirror surface coating layer 16 is set in a range of 1.0 µm or more to 20 µm or less, the layer becomes resistant to a number of injection molding processes for resin-molded products.

[0052] Therefore, since the flat surface maintaining part 18 of the mirror surface coating layer 16 of the resin molding mold 10 can ensure a stable flat surface state, it becomes possible to prevent a defective external appearance from occurring on the product surface of a resin molded product 100 when an injection molding process is carried out using the resin molding mold 10, thereby making it possible to obtain a resin molded product with an improved texture by providing a high luster.

[0053] Moreover, when the thickness of the mirror surface coating layer 16 is set to 20 μm or less, it becomes possible to effectively avoid trouble due to waviness on the surface of the flat surface maintaining member 18, which occurs at the time of evaporation of a solvent component contained in a mixed solution used in forming the mirror surface coating layer 16. (Experimental example)

[0054] Experiments were conducted in which a test plate of a resin molding die in which a mirror surface coating layer 16 was formed on a molding die 12, serving as an example, and a test plate of a resin molding die in which no mirror surface coating layer was formed on the molding die, serving as a comparative example, were prepared, and the respective test plates of the resin molding dies were evaluated. The evaluation was conducted by measuring the gloss value of the molding surface of each of the test plates of the resin molding dies. 1. Resin molding mold (practical example)

[0055] All raw materials of the mold test plates from Practical Example 1 to Practical Example 3 were made of carbon steel for mechanical engineering (S50C). Furthermore, the size of the resin mold test plates from Practical Example 1 to Practical Example 3 was set to 100 mm longitudinally, 150 mm transversely, and 10 mm thick.

[0056] Furthermore, in Practical Example 1 to Practical Example 3, embossing processes were performed using the conventional method. In addition, in Practical Example 1 to Practical Example 3, the maximum height T between embossing-forming convex portions and embossing-forming concave portions was adjusted to approximately 10 μm by the embossing process. A mirror-surface coating layer was formed on the molding surface of the test plate of each of the molding dies of Practical Example 1 to Practical Example 3. An acrylic resin was used as a resin contained in these mirror-surface layers. In Practical Example 1 to Practical Example 3, the thicknesses of the mirror-surface coating layers were changed.

[0057] In Practical Example 1 to Practical Example 3, spraying conditions of the mixed solution for forming the mirror surface coating layer were set as follows: • Coating pressure (pneumatic pressure): 0.25 MPa • Diameter of a spray gun: 0.8 mm • Coating distance: 30 mm or more to 40 mm or less • Coating direction: as vertical as possible to a mold surface of a mold • Coating location: coating room • Thickness of a coating: see Table 1 (Comparison example)

[0058] A test plate of a molding die according to Comparative Example 1 was subjected to a series of embossing processes including surface treatment by sandblasting and glass beads in the same manner as the embossing processes performed on the molding die of Practical Example 1, and the test plate had no mirror surface coating layer formed thereon. Furthermore, the raw material of all the molding dies of Comparative Example 1 was made of carbon steel for machine construction (S50C). The size of the test plate of Comparative Example 1 was also set to the same size as the test plates of Practical Example 1 to Practical Example 3. (measurement method)

[0059] The gloss value (gloss level of Gs (60°)) of the mold surface 12a of the test plate of the molding mold 12 was measured using a gloss meter manufactured by KONIKA MINOLTA, Inc. (trade name: UNI GLOSS GM-60). Gs (60°) refers to a mirror surface gloss level (level) at a measurement angle of 60 degrees.

[0060] The mirror surface luster degree was measured by the following method according to a measurement method specified by JIS Z8741-1997 "Mirror Surface Luster Degree-Measuring Method." That is, using a mirror surface luster degree measuring instrument in accordance with the above-mentioned standard, the surface reflectance was measured under a condition of an incident angle of 60°. Next, the measured value was converted into a percentage when the luster degree on the reference surface is defined as 100 and represented as the mirror surface luster degree.Regarding the reference surface, a black glass reference surface was used in which a refractive index is set to a constant value of 1.567 over the entire visible wavelength range as specified by the above-mentioned standard, and when the incident angle = 60°, a mirror surface reflectance of 10% was defined as a shimmer degree of 100.

[0061] Using a gloss meter manufactured by Konika Minolta Inc. (trade name: UNI GLOSS GM-60), which is a mirror surface gloss meter that automatically performs the above-mentioned conversion and outputs a mirror surface gloss level when measurements are taken, the respective sections of the test plate surface were measured at N = 5 under the condition of an incident angle of 60°, and the average value was defined as the mirror surface gloss level of each of the test surfaces. In addition, as the gloss value (gloss level) becomes higher, the corresponding state represents a gloss-generated state.

[0062] Table 1 shows evaluation results from practical example 1 to practical example 3 and comparative example 1. [Table 1] Thickness of a mirror surface coating layer (µm) Form surface with an embossing of a forming mold Average value (N = 5) of gloss values Practical example 1 5,2 15,4 Practical example 2 10,3 41,0 Practical example 3 20,0 59,4 Comparison example 1 - 2,1

[0063] When considering the average gloss values on the embossed mold surface of the molding die, it ranged from 15.4 to 59.4 in Practical Example 1 to Practical Example 3, and was 2.1 in Comparative Example 1. Therefore, it is confirmed that the gloss is greatly improved by forming a mirror surface coating layer on the mold surface of the molding die. When the flat surface retention part of the mirror surface coating layer on each of the molding dies from Practical Example 1 to Practical Example 3 was confirmed, no disturbance due to waviness was confirmed. List of reference symbols 10 Resin molding mold 12 Forming mold 12a mold surface 14a Embossing formation convex section 14b Imprint formation concave section 16 Mirror surface coating layer 18 Flat surface retention part 100 resin molded product 110 Product surface T Maximum height between embossing convex section and embossing concave section

Claims

[1] A resin molding mold (10) for use in molding a resin-molded glossy embossed product, comprising: a molding die (12) having an embossing-forming convex portion (14a) and an embossing-forming concave portion (14b) on a molding surface (12a) thereof, and a mirror surface coating layer (16) formed on a surface of the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b) formed on the molding surface (12a) of the molding die (12), wherein the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b) each have a flat surface, wherein an inclined surface is arranged between the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b), wherein the height (T) between the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b) is set to 10 µm or more, wherein the thickness of the mirror surface coating layer (16) is smaller than the height (T) between the embossing-forming convex portion (14a) and the embossing-forming concave portion (14b), wherein the mirror surface coating layer (16) is cured at a temperature in a range of 100°C or more to 150°C or less and is formed by a thermosetting resin having a thermal conductivity in a range of 0.10 W / (mK) or more to 0.99 W / (mK) or less, the mirror surface coating layer (16) has a thickness in a range of 1.0 µm or more to 20 µm or less to prevent a disturbance due to waviness on the surface of the mirror surface coating layer (16), and the mirror surface coating layer (16) has a flat surface such that a gloss surface of the mirror surface coating layer (16) measured by a 60° gloss meter has a gloss value of 15.4 or more to 59.4 or less.

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