JP6350558B2 - Molding method of resin molded products - Google Patents

Description

The present invention also relates surfaces uneven pattern of the substrate is formed within the molding how the resin molded article formed is covered with a surface layer having a visible light transmittance.

  Various products such as automobile interior materials and exterior materials, household items, and office supplies are molded from synthetic resin. Recently, there is a growing demand for decoration of such resin molded products. Regarding the decorating technique, Patent Document 1 discloses that a transparent texture is formed on the upper surface of a transparent or opaque first synthetic resin film, and a transparent second synthetic resin composed of one or more layers on the texture. Disclosed is a decorative film in which films are laminated.

  Moreover, in patent document 1, when using the synthetic resin which kneaded the flake-like or powdery luster material in the 1st synthetic resin film, when laminating | stacking a 2nd synthetic resin film on a 1st synthetic resin film, The difference in melt flow rate between the synthetic resins forming the two films is set to 0.5 to 50 g / min so that the wrinkles are not crushed by heating, both the synthetic resin films may be colored, Since it has glitter, it reflects light well, the reflection of light differs depending on the viewing direction, and the appearance of shadows is different, so that there is a stereoscopic effect and a high-class feeling is described.

JP 2005-14374 A

  By the way, in obtaining a resin molded product obtained by laminating a surface layer having visible light permeability on the surface of the substrate with the concavo-convex pattern formed, when injection molding is adopted for forming the surface layer, the concavo-convex pattern on the surface of the substrate is obtained. There is a problem that it is broken by the injected resin material. That is, for example, when a resin material for surface layer molding is injected in a state where the base material is inserted into the cavity for surface layer molding, the shearing heat generation of the resin material flowing along the surface of the base material in the cavity and the flow thereof The problem is that the unevenness of the uneven pattern is deformed by the shearing force applied to the uneven pattern. Particularly, in the vicinity of the gate of the cavity, since the heat generation and the shearing force continue to be applied to the concavo-convex pattern of the base material until the injection is finished, the concavo-convex pattern tends to collapse.

  The subject of this invention is solving the problem that the uneven | corrugated pattern on the surface of a base material collapse | crumbles by the resin material for surface layers inject | emitted by the cavity.

  In order to achieve the above object, in the present invention, the shearing force that tends to increase in the vicinity of the gate is suppressed by making the injection process of the secondary resin multistage.

In other words, tree fat moldings, surface irregularities height in the surface layer the surface thickness having a visible light transmittance is less 0.8mm or 8mm uneven pattern is formed substrate is 5μm or more 700μm or less It is a resin molded article to be covered, and the surface layer includes a first surface layer that covers a part of the uneven pattern, the first surface layer, and the other uneven surface that is not covered by the first surface layer. It is good also as a structure provided with the 2nd surface layer which covers a part.

According to this configuration , since both the first surface layer and the second surface layer are visible light transmissive, the uneven pattern under the first surface layer is viewed through the first surface layer and the second surface layer, so that the three-dimensional effect of the uneven pattern is clear. It can contribute to the improvement of design and aesthetics. Moreover, the 1st surface layer becomes a protective layer and the shear force to the base material given during the resin flow of the 2nd surface layer can be suppressed.

In another aspect, the resin material of the first surface layer and the resin material of the second surface layer may be the same resin material. Thereby, the interface between the first surface layer and the second surface layer is not visually noticeable, and the aesthetic appearance of the resin molded product is not impaired.

Another state like may be configured of a different resin material from the first surface of the resin material and the second surface layer of the resin material. The resin material of the first surface layer and the resin material of the second surface layer may have different refractive indexes. Thereby, a difference arises in the visibility of an uneven | corrugated pattern and it can contribute to the improvement of the designability of a resin molded product.

In another embodiment, the substrate may be configured to contain a luminous material and / or inorganic pigments. Thereby, the melt flow rate of a base material becomes lower than the melt flow rate of the matrix resin itself which comprises this base material. Therefore, when the surface layer is injection-molded, it is advantageous in avoiding the concavo-convex pattern of the base material from collapsing due to the flowing resin material. This means that it is not always necessary to employ a resin material having a melting point lower than that of the matrix resin of the base material as the resin material for the surface layer. Therefore, the selection range of the resin material is expanded.

  In addition, the said base material can contain an aluminum flake, for example as said brilliant material, and can contain titanium, carbon, iron oxide etc. as said inorganic pigment.

Disclosed here methods, surface irregularities height in the surface layer the surface thickness having a visible light transmittance is less 0.8mm or 8mm uneven pattern is formed substrate is 5μm or more 700μm or less A method of forming a resin molded article to be covered, the step of forming a cavity for molding the surface layer on the surface side of the base material on which the uneven pattern is formed, and a primary resin in the vicinity of the gate of the cavity a step of injecting the material, so as to cover the primary resin material injected into the gate near the cavity, and a step of molding the surface layer by injecting secondary resin material, the base material is bright materials and The primary resin material and the secondary resin material are the same resin material, and the step of injecting the primary resin material is performed by using the primary resin material to form the rugged pattern in the gate pattern. A step of covering a part of the rugged pattern and protecting a part of the concavo-convex pattern, and the step of forming the surface layer includes the secondary resin material, the primary resin material, and the concavo-convex pattern of the concavo-convex pattern. It is a process of covering other parts not covered with the primary resin material .

Also, equipment, the thickness of the surface height of unevenness is 5μm or more 700μm or less is uneven pattern has been formed substrate to the surface having a visible light transmittance is covered by the following surface 0.8mm or 8mm A resin molding product molding apparatus comprising: a core mold on which the base material is disposed; and a resin material for the surface layer on the surface side on which the concavo-convex pattern of the base material disposed on the core mold is formed. A cavity mold for forming a cavity for receiving the first gas, a first gate connected to the cavity for injecting a primary resin material into the cavity, and the base connected to the cavity and more than the first gate. It is good also as a structure provided with the 2nd gate for injecting the secondary resin material in the said cavity formed in the side away from the surface in which the said uneven | corrugated pattern was formed.

  In the vicinity of the gate, the extrusion pressure of the resin is high and shearing force and shearing heat are easily applied. In particular, when resin is poured into the interior of the cavity, the resin extrusion pressure in the vicinity of the gate increases, and the shearing force and heat generation to the uneven pattern increase.

According to the above configuration , after injecting a small amount of the primary resin material from the first gate into the cavity, the secondary resin material is injected from the second gate so as to cover the primary resin material. In addition, the primary resin material can be protected, and the shearing force and heat generation can be suppressed to prevent the irregular pattern near the gate from being disturbed.

  In a preferred embodiment, the primary resin material and the secondary resin material are the same resin material. Accordingly, for example, a single runner for injecting a resin material into the cavity can be used and a plurality of gates can be switched, and the process can be simplified and the cost can be reduced.

  In a preferred embodiment, the substrate contains a bright material and / or an inorganic pigment. Thereby, the melt flow rate of a base material becomes lower than the melt flow rate of the matrix resin itself which comprises this base material. Therefore, when the surface layer is injection-molded, it is advantageous in avoiding the concavo-convex pattern of the base material from collapsing due to the flowing resin material. This means that it is not always necessary to employ a resin material having a melting point lower than that of the matrix resin of the base material as the resin material for the surface layer. Therefore, the selection range of the resin material is expanded.

  In addition, the said base material can contain an aluminum flake, for example as said brilliant material, and can contain titanium, carbon, iron oxide etc. as said inorganic pigment.

  According to the present invention, since both the first surface layer and the second surface layer are transparent to visible light, the uneven pattern under the first surface layer is viewed through the first surface layer and the second surface layer, so the three-dimensional effect of the uneven pattern is clear. It can contribute to the improvement of design and aesthetics. Moreover, the 1st surface layer becomes a protective layer and the shear force to the base material given during the resin flow of the 2nd surface layer can be suppressed.

The perspective view which shows a resin molded product in a partial cross section. The side view which made the partial cross section which shows typically an example of the shaping | molding apparatus of a resin molded product. The expanded sectional view of the metal mold | die part for shaping | molding of the resin material for surface layers in the apparatus shown in FIG. The figure which shows typically a mode that the 1st resin material for surface layers is inject | poured into a cavity in the metal mold | die of FIG. The figure which shows typically a mode that the 2nd resin material for surface layers is inject | poured into a cavity in the metal mold | die of FIG. The figure which shows typically a mode that injection | pouring of the resin material for surface layers was completed in the metal mold | die of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its use.

<Example of resin molded product>
In the resin molded product 1 shown in FIG. 1, 2 is a base material, and 3 is a surface layer covering the surface of the base material 2. An uneven pattern 4 is formed on the surface of the substrate 2. The substrate 2 is formed of a substrate resin material containing a glittering material and / or an inorganic pigment. The surface layer 3 is formed of a surface layer resin material 23 and includes a first surface layer 31 and a second surface layer 32.

  The uneven height of the uneven pattern 4 of the substrate 2 is 5 μm or more and 700 μm or less. When the uneven height of the uneven pattern is smaller than 5 μm, the visibility of the uneven pattern is deteriorated, and when it exceeds 700 μm, it is disadvantageous for forming a fine pattern. It is preferable that the height of the unevenness is 10 μm or more and 350 μm or less.

  Moreover, the thickness of the surface layer 3 is 0.8 mm or more and 8 mm or less. When the thickness of the surface layer is smaller than 0.8 mm, it becomes difficult to form the surface layer, and when the thickness is larger than 8 mm, it is difficult to ensure the smoothness of the surface.

  As shown in FIG. 1, the first surface layer 31 covers a part of the concavo-convex pattern 4. The second surface layer 32 covers the first surface layer 31 and other portions of the concavo-convex pattern 4 that are not covered by the first surface layer 31.

  The first surface layer 31 and the second surface layer 32 each contain a coloring material or no coloring material, and include a first resin material for surface layer (primary resin material) 23a and a second resin material for surface layer (secondary resin material) 23b. Is formed by. Since the surface layer resin material 23 that forms the surface layer 3 has visible light transmittance, the uneven pattern 4 on the surface of the substrate 2 can be visually recognized through the surface layer 3.

  Various resin materials can be used for the base material 2 and the surface layer 3, and as the resin material 21 for the base material, PC (polycarbonate), ABS resin, PC-ABS (polymer alloy of PC and ABS resin). Etc., and PC, PMMA (polymethyl methacrylate resin), and the like can be preferably used as the surface layer resin material 23. Thereby, the aesthetics and durability of the resin molded product 1 can be made compatible.

  The first resin material for surface layer 23a and the second resin material for surface layer 23b may be the same resin material. Thereby, the interface of the 1st surface layer 31 and the 2nd surface layer 32 is not visually conspicuous, and the aesthetics of the resin molded product 1 are not impaired. Further, the surface layer first resin material 23a and the surface layer second resin material 23b may be different resin materials. Further, the surface layer first resin material 23a and the surface layer second resin material 23b may have the same or different refractive indexes. The higher the refractive index, the lower the visible light transmittance. When the refractive index is too low, the interface reflection with the surface of the substrate 2 increases. When the refractive index is different, a difference in visibility of the concavo-convex pattern 4 occurs, which can contribute to the improvement of the design of the resin molded product 1.

  Examples of the bright material contained in the base material 2 include aluminum flakes. Examples of the inorganic pigment contained in the substrate 2 include titanium, carbon, and iron oxide. When the base material 2 contains a bright material and / or an inorganic pigment, the melt flow rate of the base material 2 becomes lower than the melt flow rate of the matrix resin itself constituting the base material 2. Therefore, when the surface layer 3 is injection-molded, it is advantageous to avoid the concavo-convex pattern 4 of the base material 2 from collapsing due to the flowing resin material. This means that it is not always necessary to employ a resin material having a melting point lower than that of the matrix resin of the substrate 2 as the resin material for the surface layer 3. Therefore, the selection range of the resin material is expanded.

  According to this configuration, since both the first surface layer 31 and the second surface layer 32 are visible light transmissive, the uneven pattern 4 under the first surface layer 31 is viewed through the first surface layer 31 and the second surface layer 32. The three-dimensional effect of the pattern 4 becomes clear and can contribute to the improvement of design and aesthetics. Moreover, the 1st surface layer 31 becomes a protective layer, and the shearing force to the base material given during the resin flow of the 2nd surface layer can be suppressed.

<Molding equipment for resin molded products>
A molding apparatus 5 shown in FIG. 2 molds the resin molded product 1 by a two-color molding method.

  In the molding apparatus 5, 6 is a primary cavity mold having a primary cavity surface 6 a that molds the concave-convex pattern 4 of the substrate 2, 14 is a secondary cavity mold having a secondary cavity surface 7 a that molds the surface of the surface layer 3, Reference numeral 8 denotes a core mold common to both cavity molds 6 and 14. The primary cavity surface 6a of the primary cavity mold 6 is textured to form the concavo-convex pattern 4 on the substrate surface.

  Both cavity molds 6 and 14 are arranged on the base 9 so as to face each other with the core mold 8 interposed therebetween, and are movable in a direction away from each other (mold opening direction). The core mold 8 is supported by a rotary 11 that rotates about a vertical axis, and includes a molding surface 8a that molds the back surface side of the base material 2 on both sides that are opposite to each other.

  A base molding cavity 12 is formed by the primary cavity mold 6 and the core mold 8. Further, the base cavity 2 is accommodated by the secondary cavity mold 14 and the core mold 8, and the surface layer forming cavity 13 for injection molding the surface layer 3 is formed on the surface side of the base material 2 on which the concave and convex pattern 4 is formed. To do. That is, the surface layer forming cavity 13 includes the surface on which the concave / convex pattern 4 of the base material 2 disposed on the core mold 8 is formed, the inner wall surface of the second member 27 of the secondary cavity mold 14, and the secondary cavity mold 14. The surface layer resin material 23 is accommodated in the surface layer forming cavity 13. In FIG. 2, 15 is a runner that communicates with the base material forming cavity 12, and 16 is a gate connected to the cavity 12. Reference numeral 17 denotes a runner communicating with the surface molding cavity 13, and 18 and 19 denote gates connected to the cavity 13.

  A first injection unit 22 for injecting the base material resin material 21 for base material molding is disposed on the back of the primary cavity mold 6. A second injection unit 24 for injecting a surface layer resin material 23 for surface layer molding is disposed on the back of the secondary cavity mold 14. Both the injection units 22 and 24 can be advanced and retracted relative to the cavity molds 6 and 14.

  As shown in FIG. 3, the second member 27 of the secondary cavity mold 14 has a first gate 18 for injecting the surface first resin material 23 a into the surface layer forming cavity 13, and the first gate 18. A second gate for injecting the surface second resin material 23b into the cavity 13 is connected to the surface layer forming cavity 13 on the side of the base material 2 away from the surface on which the concave and convex pattern 4 is formed. It is formed as follows.

  The gates 18 and 19 connected to the surface layer forming cavity 13 may be any shape, but are preferably film gates. When employing a film gate, for example, the width of the gates 18 and 19 may be 10 mm or more, and the thickness of the gates 18 and 19 may be 0.5 mm or more. Further, the first gate 18 may be set at a height away from the surface of the base material 2 in the thickness direction of the base material 2. Thereby, it can suppress that the 1st resin material 23a for surface layers inject | emitted from the 1st gate 18 applies to the uneven | corrugated pattern 4 directly. Even if the surface of the second gate 19 facing away from the base material 2 is flush with the secondary cavity surface 7 a for molding the surface of the surface layer 3 of the surface layer forming cavity 13. Good.

  The distance between the first gate 18 and the surface of the substrate 2 is preferably 0.5 mm or more. For example, when the thickness of the surface layer 3 is 1.5 mm or more, the width of the first gate 18 is 15 mm or more, and the thickness of the first gate 18 is 1.0 mm or more. The distance from the surface is preferably 0.5 mm or more. Further, when the thickness of the surface layer 3 is 2.5 mm or more, the width of the first gate 18 is 20 mm or more, the thickness of the first gate 18 is 1.5 mm or more, and the first gate 18 and the base material 2 are formed. The distance from the surface is preferably 1.0 mm or more.

  The first gate 18 and the second gate 19 may be adjacent or separated. Specifically, for example, when the thickness of the surface layer 3 is 2.0 mm, the thickness of the first gate 18 can be 0.5 mm or more, and the thickness of the second gate 19 can be 0.5 mm or more. That is, when the thickness of the first gate 18 is 1.0 mm and the thickness of the second gate 19 is also 1.0 mm, the distance between the first gate 18 and the surface of the substrate 2 is 0 mm, and the second gate 19 The surface of the surface layer 3 is flush with the secondary cavity surface 7a. When the thickness of the first gate 18 is 0.5 mm and the thickness of the second gate 19 is also 0.5 mm, the distance between the first gate 18 and the surface of the substrate 2 is 0.5 mm, and the second gate 19 When the surface on the surface layer 3 side is flush with the secondary cavity surface 7a, the distance between the surface on the surface layer 3 side of the first gate 18 and the surface on the base material 2 side of the second gate 19 is 0.5 mm. .

<Method of molding resin molded product>
A method for molding the resin molded product 1 using the molding apparatus 5 will be described.

  The cavity molds 6, 14 and the core mold 8 are clamped, the first injection unit 22 is advanced, and the molten substrate resin material 21 is injected into the substrate molding cavity 12. Thereby, the base material 2 which has the uneven | corrugated pattern 4 on the surface is formed.

  After the mold opening, the core mold 8 is inverted 180 degrees by the rotary 11 together with the molded base material 2 and clamped. Thereby, as shown in FIG. 3, a surface layer forming cavity 13 is formed between the surface of the substrate 2 and the secondary cavity mold 14.

  Next, as shown in FIG. 4, the second injection unit 24 is advanced, and the melted first resin material 23 a for the surface layer is injected into the surface molding cavity 13 through the first gate 18.

  At this time, the surface first resin material 23 a is injected onto the concavo-convex pattern 4 in the vicinity of the first gate 18. At this time, the ratio of the injection amount with respect to the total amount of the surface layer resin material 23 of the surface layer first resin material 23a is a volume ratio from the viewpoint of reducing the shear heat generation and the shear force applied to the uneven pattern 4 in the vicinity of the first gate 18. Preferably they are 3% or more and less than 50%, More preferably, they are 5% or more and 45% or less, Especially preferably, they are 7% or more and 40% or less.

  Next, after completion of the injection of the first resin material 23a for the surface layer from the first gate 18, the second resin material 23b for the surface layer from the second gate 19 is put into the cavity 13 for molding the surface layer after a predetermined switching time. Eject.

  The switching time is preferably 5 seconds or less from the viewpoint of maintaining the state in which the surface layer first resin material 23a is not collapsed and is not too hard.

  The second surface layer resin material 23b is injected so as to cover the first surface layer resin material injected in the vicinity of the first gate of the surface layer forming cavity 13, that is, the first surface layer. Then, the surface layer second resin material 23b is injected into the surface layer molding cavity 13 up to an injection amount of 100%. At this time, the ratio of the injection amount with respect to the total amount of the surface layer resin material 23 of the surface layer second resin material 23b alleviates the shear heat generation and the shear force applied to the concavo-convex pattern 4, and prevents the first surface layer 31 from being crushed. From the viewpoint, the volume ratio is preferably more than 50% and 97% or less, more preferably 55% or more and 95% or less, and particularly preferably 60% or more and 93% or less.

  By the above process, the surface layer 3 which covers the surface of the base material 2 is formed, and the resin molded product 1 which has the uneven | corrugated pattern 4 in the interface of the base material 2 and the surface layer 3 is obtained.

  In the vicinity of the gate, the extrusion pressure of the resin is high and shearing force and shearing heat are easily applied. In particular, when the surface layer resin material 23 is poured into the depth of the surface layer forming cavity 13, the extrusion pressure of the resin in the vicinity of the gate increases, and the shearing force and shear heat generation to the uneven pattern 4 increase.

  According to this configuration, after injecting a small amount of the first surface layer resin material 23a from the first gate 18 into the surface layer molding cavity 13, the second gate 19 covers the surface layer first surface so as to cover the surface layer first resin material 23a. By injecting the second resin material 23b, the concavo-convex pattern 4 in the vicinity of the first gate 18 can be protected with the first resin material 23a for the surface layer first, and the ruggedness in the vicinity of the gate can be suppressed by suppressing shear force and shear heat generation. Disturbance of the pattern 4 can be prevented.

  The melting temperature t2 of the surface layer resin material 23 is preferably lower than the melting temperature t1 of the base material resin material 21 (for example, the temperature difference (t1−t2) is 0 ° C. or more and 50 ° C. or less). In the injection molding of the base material 2 and the surface layer 3, for example, when PC is used as each matrix resin, for example, the mold temperature is about 80 ° C. and the cylinder temperatures of the injection units 22 and 24 are about 250 ° C. to 300 ° C. Good.

(Other embodiments)
In the above-described embodiment, the gate has two stages of the first gate 18 and the second gate 19, but the number of gates may be further increased to have three or more stages. As a result, the amount of the surface layer resin material injected from one gate is reduced, and the flow rate of the surface layer resin material flowing along the surface of the base material is reduced. It is possible to effectively reduce the shear heat generation and the shear force applied to the uneven pattern 4.

  The volume of the surface layer forming cavity 13 may be set larger than the volume of the surface layer 3. That is, the secondary cavity mold 14 may be provided in a compressible manner after the surface layer resin material 23 is injected into the surface layer molding cavity 13. In this case, the compression ratio of the volume of the surface layer forming cavity 13 by the secondary cavity mold 14, that is, before compression of the surface layer forming cavity 13 before the surface layer resin material 23 is injected into the surface layer forming cavity 13. Compression of the surface molding cavity 13 after the secondary cavity mold 14 is moved to the substrate 2 side and the surface resin material 23 is compressed after the surface layer resin material 23 is injected into the surface molding cavity 13 with respect to the volume. The ratio of the rear volume (= post-compression volume / pre-compression volume × 100 (%)) is preferably 50% to 95%, more preferably 55% to 90%, and particularly preferably 60% to 85%. is there.

  Specifically, for example, the surface area of the substrate 2 on which the uneven pattern 4 is formed can be constant, and the height of the surface layer forming cavity 13 can be set variably. That is, after the surface layer resin material 23 is injected into the surface layer forming cavity 13, the first member 7 of the secondary cavity mold 14 is moved to the surface side of the base material 2 on which the concavo-convex pattern 4 is formed. The surface layer resin material 23 can be compressed. At this time, the initial height of the surface molding cavity 13 is preferably 1.05 times or more and 2.00 times or less of the final height of the surface layer molding cavity 13, that is, the thickness of the surface layer 3, more preferably 1. It is 10 times or more and 1.80 times or less, and particularly preferably 1.17 times or more and 1.65 times or less.

  Thus, by setting the volume of the surface layer molding cavity 13 to be larger than the volume of the surface layer 3 and forming the surface layer 3 by compression molding after injection of the surface layer resin material 23, the surface layer 3 can be injection molded. Along with this, the heat generation and the shearing force applied to the concavo-convex pattern 4 on the surface of the base material 2 from the surface layer resin material 23 are effectively suppressed, which is advantageous for preventing the concavo-convex pattern 4 from collapsing.

  In the above embodiment, the two-color molding method is employed for molding the resin molded product. However, the present invention may employ an insert molding method in which the base layer is inserted into a mold and the surface layer is injection molded.

<Examples of resin molded products>
As shown in Table 1, the surface layer 3 was formed on the surface of the substrate 2. Both the matrix resin of the base material 2 and the surface layer 3 is PC. The concavo-convex pattern 4 on the surface of the substrate 2 has a concavo-convex height of 55 μm. In the injection molding, the mold temperature was 80 ° C., and the cylinder temperatures of the injection units 22 and 24 were 250 ° C. or 260 ° C. Then, the collapsed state of the uneven pattern 4 of the obtained resin molded product was visually evaluated.

  In the evaluation column of Table 1, “◎” indicates that the concavo-convex pattern has a strong shade and depth (three-dimensional effect) and that the concavo-convex pattern does not collapse (best quality). There is a sense of depth and almost no deformation of the uneven pattern is observed (good quality), “△” indicates that the uneven pattern is slightly washed away and the deformation is recognized (low quality), and “×” indicates a relatively wide range. It means that the collapse of the concavo-convex pattern is observed (defect).

  In Examples 1 to 3 and Comparative Examples 1 and 2, the cylinder temperature is 250 ° C., the surface layer thickness is 2.0 mm, and the first gate and the second gate are adjacent to each other. In Examples 1 to 3, the injection amount from the first gate increased from 10% to 30%, but all had high quality.

  In Comparative Example 1, the resin material for the surface layer was injected only from the second gate, but a slight disturbance was observed in the concavo-convex pattern 4 of the base material 2.

  In Comparative Example 2, the injection amount from the first gate was increased to 40%, but a slight disturbance was observed in the uneven pattern 4 in the vicinity of the first gate. From this, it is considered that if the amount of injection from the first gate is too large, the shear heat generation and the shearing force applied to the concavo-convex pattern 4 in the vicinity of the gate increase, leading to disturbance of the concavo-convex pattern 4.

  In Examples 4 and 5, the cylinder temperature is 260 ° C., the surface layer thickness is 3.0 mm, and the first gate and the second gate are separated by 1.0 mm. In Examples 4 and 5, the injection amounts from the first gate were 10% and 20%, respectively, but both were high quality.

  In Example 6, the cylinder temperature is 260 ° C., the surface layer thickness is 3.0 mm, and the first gate and the second gate are separated by 0.5 mm. Therefore, the surface of the first gate on the substrate 2 side is separated from the surface of the substrate 2 by 0.5 mm. Also in Example 6, a high-quality resin molded product was obtained.

  In the present invention, since both the first surface layer and the second surface layer are visible light transmissive, the uneven pattern under the first surface layer is viewed through the first surface layer and the second surface layer, so that the three-dimensional effect of the uneven pattern becomes clear and the design Can contribute to the improvement of sexuality and aesthetics. Moreover, since the 1st surface layer becomes a protective layer and the shear force to the base material given during the resin flow of the 2nd surface layer can be suppressed, it is very useful.

DESCRIPTION OF SYMBOLS 1 Resin molding 2 Base material 3 Surface layer 4 Uneven | corrugated pattern 5 Molding device 6 Primary cavity type 6a Primary cavity surface 7 First member 7a Secondary cavity surface 8 Core type 8a Molding surface 9 Base 11 Rotary 12 Base material molding cavity 13 Surface layer Molding cavity (cavity)
14 Secondary cavity mold 18 First gate 19 Second gate 21 Base material resin material 22 First injection unit 23 Surface layer resin material 23a Surface layer first resin material (primary resin material)
23b Second resin material for surface layer (secondary resin material)
24 Second injection unit 27 Second member 31 First surface layer 32 Second surface layer

Claims (2)

A resin molded article in which the surface of a substrate having a concavo-convex pattern with a concavo-convex height of 5 μm or more and 700 μm or less is covered with a surface layer having a visible light transmission thickness of 0.8 mm or more and 8 mm or less. A molding method,
Forming a cavity for forming the surface layer on the surface side of the substrate on which the uneven pattern is formed;
Injecting a primary resin material in the vicinity of the gate of the cavity;
Forming the surface layer by injecting a secondary resin material so as to cover the primary resin material injected in the vicinity of the gate of the cavity ,
The base material contains a bright material and / or an inorganic pigment,
The primary resin material and the secondary resin material are the same resin material,
The step of injecting the primary resin material is a step for protecting a part of the concavo-convex pattern by covering the part of the concavo-convex pattern near the gate with the primary resin material,
The step of forming the surface layer is a step of covering the primary resin material and other portions of the concavo-convex pattern that are not covered by the primary resin material with the secondary resin material. A method for molding a resin molded product. In claim 1 ,
The said base material contains aluminum flakes as said brilliant material, The molding method of the resin molded product characterized by the above-mentioned.

Images