JP4230474B2 - Thin plate injection molding simultaneous decorating product that eliminates residual stress, individual molded product, thin plate injection molding simultaneous decorating mold, and manufacturing method of thin plate injection molding simultaneous decorating product - Google Patents

Description

  The present invention relates to a sheet-like injection-molded simultaneous decorated product, an individual molded product, a sheet-shaped injection-molded simultaneous mold for manufacturing the same, and a sheet-shaped injection-molded simultaneously decorated product. This relates to the manufacturing method.

  Conventionally, as a surface member including a display window portion of an optical product such as a mobile phone, a thin plate-like injection-molded simultaneous decorating product has been used. Optical display properties and the like are required for optical product display windows.

  As a manufacturing method of thin plate-like injection molding simultaneous decoration products, conventionally, in order to prevent the occurrence of welds, etc. in the central part of the molded product, the product molding space and the resin discharge molding adjacent to the mold A space is provided to inject molten resin into the product formation space, and melt into the product molding space while discharging a part of the injected molten resin from the product molding space to the resin discharge molding space. There is known a method of manufacturing a thin plate-like injection-molded simultaneously decorated article filled with a molding resin in a state. (For example, refer to Patent Document 1).

  In addition, in order to reduce molding distortion of injection molded products, there is also a compression molding method that obtains a molded product by injecting molten molding resin into the mold cavity and then compressing the molten resin in the mold cavity. Are known. (For example, refer to Patent Document 2).

JP 2004-314611 A Japanese Patent Laid-Open No. 11-179769

  When manufacturing a thin plate-like injection-molded decorative product, the molten resin injected into the mold cavity is first solidified from a portion away from the gate, so that residual stress tends to remain in the vicinity of the gate. In addition, in order to manufacture thin plate-like injection-molded decorative products, in order to prevent ink flow, molding is often performed at a temperature lower than the mold temperature recommended by the resin manufacturer, and the injection speed of the molten resin is also high. Since a restriction is added from the viewpoint of using the decorative sheet, it must be performed at a constant speed or less. For this reason, residual stress tends to remain more easily in the thin plate-like injection-molded simultaneous decorative article.

  The residual stress of the sheet-like injection molded simultaneous decorating product thus produced appears as optical distortion. This is a serious problem for thin-plate injection-molded and simultaneously decorated articles used for applications such as display windows for mobile phones.

  Compression molding is known as a method for reducing such residual stress. However, although compression molding is effective for resin filling and degassing, when applied to the sheet-like injection molding simultaneous decorating method, as described above, because the mold temperature and the injection speed of the molten resin are limited, It is difficult to reduce the residual stress in the vicinity of the gate, and there is a problem that it becomes a thin plate-like injection-molded simultaneous decorating product in which optical distortion remains in the vicinity of the gate trace.

  Then, this invention makes it a subject to obtain the thin plate-like injection molding simultaneous decorating product which eliminated the residual stress. Moreover, this invention makes it a subject to obtain the metal mold | die for thin-plate injection molding simultaneous decorating for manufacturing the thin-plate injection molding simultaneous decorating product without a residual stress. Furthermore, this invention makes it a subject to provide the manufacturing method of the thin-plate injection molding simultaneous decorating product for manufacturing the thin-plate injection molding simultaneous decorating product without a residual stress.

  Other problems of the present invention will become apparent from the following description of the present invention.

The thin plate-like injection-molded simultaneous decorative article according to one aspect of the present invention includes a single or a plurality of individual molded product parts, a stress buffer part residue and a gate trace, and at least one of the individual molded product part and the gate trace. There is a stress buffer part residue in between, and the individual molded product part has a thin plate shape and an average thickness of 0.6 mm to 1.5 mm, and is decorated using a first decorative sheet on one surface. The stress buffer portion residue is formed by flowing the molding resin substantially radially , with the thickness of at least a portion being thicker than the average thickness of the individual molded product portion.

  According to the present invention, when the molten resin injected into the mold cavity is cooled at the time of thin plate-like injection molding simultaneous decoration, the resin in the individual molded part separated from the gate is solidified first, Pressure remains on the resin that is still molten in the stress buffer portion, and residual stress concentrates on the residue of the stress buffer portion when solidified thereafter. Therefore, the individual molded product portion is free from optical distortion.

  Although the stress buffer portion residue has a stress buffering effect by having a constant volume, in the present invention, at least a part of the thickness is made thicker than the average thickness of the individual molded product portion. For this reason, the area of the stress buffer part space which occupies in the inner surface of the mold can be reduced, and accordingly, the distance between the individual molded product parts can be reduced. Therefore, the area of the decorative sheet placed in the mold can be reduced. There is an effect that can be reduced. In particular, this effect is remarkable in the case of so-called multiple picking, in which a plurality of individual molded product parts are arranged in one mold.

  The individual molded product portion and the stress buffer portion residue may be continuous, or a margin portion may be interposed between them. The margin portion is usually thicker or substantially equal in thickness to the individual molded product portion. Here, “substantially equal” means a range that is the same as the thickness of the individual molded product part and is 0.3 mm thinner at the maximum than the thickness of the individual molded product part.

The shape of the stress buffer portion residue formed by the molding resin flowing substantially radially in the surface flow path is a circular planar shape, a triangular planar shape, a sectoral planar shape, and a planar shape. Including polygonal objects.

  In the present invention, the individual molded product part has a thin plate shape and an average thickness of 0.6 to 1.5 mm. If the average thickness is less than 0.6 mm, there is a problem in terms of strength, and there is a problem that the shape cannot be correct due to poor filling of the molding resin during molding. This is because if the average thickness is greater than 1.5 mm, residual stress does not occur in the individual molded product portion even if the present invention is not carried out.

  The shape of the individual molded part includes a shape having a substantially constant thickness over substantially the entire individual molded part, a part having one or a plurality of holes in a part of the individual molded part, the surface of the individual molded part and / or Or what has unevenness | corrugations, such as a nail | claw shape and a boss | hub shape, is included in a back surface. Furthermore, the shape in which the individual molded product part has one or a plurality of stepped parts is also included.

  The first decorative sheet may be a transfer sheet or an insert sheet. The transfer sheet is prepared by, for example, sequentially forming a release layer, a release layer, a decorative layer, and an adhesive layer on one surface of the base sheet. For example, the insert sheet is formed by sequentially forming a decorative layer and an adhesive layer on one surface of the base sheet.

  The shape of the decoration layer is a character, a geometric pattern, a solid, or the like. Examples of the material for the decorative layer include acrylic resins, nitrified cotton resins, polyurethane resins, chlorinated rubber resins, vinyl chloride-vinyl acetate copolymer resins, polyamide resins, polyester resins, and epoxy resins. However, it is not particularly limited. Further, the decorative layer may be provided with a metal film layer such as aluminum, chromium, copper, nickel, indium, tin, or silicon oxide by a method such as vacuum deposition or plating. In this case, the metal film layer may be entirely or patterned.

  The thickness of the decorative layer is preferably 0.5 μm to 50 μm. When the film thickness is less than 0.5 μm, there is a problem that sufficient designability cannot be obtained, and when it is more than 50 μm, there is a problem that it is difficult to dry after printing. However, in the case of a metal film layer, 50 to 1200 mm is preferable. This is because if the thickness of the metal film layer is less than 50 mm, there is a problem that sufficient metallic luster cannot be obtained, and if it is more than 1200 mm, there is a problem that cracks are likely to occur.

  General decoration methods such as gravure printing, screen printing, offset printing method, tampo printing, painting, various coating methods, vapor deposition, ion plating, sputtering method, etc. are used for the method of providing the decorative layer with the entire surface or pattern. There are laws.

  The thin plate-like injection-molded simultaneous decorative article according to the present invention can be manufactured under the injection conditions suitable for the thin-plate injection-molded simultaneous decoration using the decorative sheet, and the thin plate-like injection molded simultaneous decorative article with reduced ink flow and the like It is.

  In the sheet-like injection-molded simultaneous decorating product according to a preferred embodiment of the present invention, the first decorating surface of the individual molded product part and the surface or back surface of the stress buffering part residue may be substantially coplanar.

  According to this preferred embodiment, on the inner surface of the mold used at the time of thin-plate injection molding simultaneous decoration, the surface that forms the first decoration surface of the individual molded product portion and the stress buffer portion residue are formed. The plane is substantially the same plane. For this reason, it becomes easy to align the decorative sheet at the time of thin-plate injection molding simultaneous decoration, and the frequency of occurrence of twisting of the decorative sheet is reduced, and the decorative position of the thin-plate injection molding simultaneous decoration product is uniform. In addition, it becomes a beautiful thin-plate shaped simultaneous decorating product.

  In the thin plate-like injection-molded simultaneous decorative article according to another preferred embodiment of the present invention, a second decorative sheet is used for decoration on the other surface of the first decorative surface of the individual molded product portion. You may have made the 2nd decorating surface.

  According to this preferred embodiment, it is a thin plate-like injection-molded simultaneous decorative product including individual molded product parts for simultaneous double-sided decoration, and is a thin-plate injection molded simultaneous decorated product that eliminates residual stress in the individual molded product parts. .

  The second decorative sheet may be a transfer sheet or an insert sheet. Here, both the first decorative sheet and the second decorative sheet may be a transfer sheet, both may be an insert sheet, the first decorative sheet may be a transfer sheet, and the second decorative sheet may be a combination of an insert sheet. The first decorative sheet may be a combination of an insert sheet and the second decorative sheet may be a combination of a transfer sheet.

  In the sheet-like injection-molded simultaneous decorative article according to another preferred embodiment of the present invention, the sheet-like injection-molded simultaneous decorated article is formed by injecting a molten resin into the molding space of the mold, and then the molding space. It may be manufactured through a process of reducing the volume of the molten resin and compressing the injected molten resin.

  According to this preferred embodiment, it is possible to eliminate residual stress due to the stress buffer space residue and to reduce residual stress by the compression molding method at the same time. The residual stress is eliminated.

  The individual molded product according to another aspect of the present invention is an individual molded product separated from the sheet-like injection molded simultaneous decorative product according to the present invention.

  In this preferred embodiment, the separation includes cutting by router processing or punching by Thomson processing.

  The thin plate-like injection molding simultaneous decorating mold according to another aspect of the present invention includes a single or a plurality of individual molded product part space portions and stress between the injection molding simultaneous decorating molds arranged to face each other. It has a molding space part including a buffering space part, and is used to obtain a thin plate-like injection-molded simultaneous decorative article according to the present invention.

  A method for producing a sheet-like injection-molded simultaneous decorative article according to another aspect of the present invention includes a decorative sheet disposed on the inner surface of the individual molded article space of the mold according to the present invention, and the molding of the mold. This is a method for producing a sheet-like injection-molded and simultaneously decorated product, in which a molten resin is injected into a space portion, cooled and solidified, and then opened to take out the sheet-like injection-molded and simultaneously decorated product according to the present invention.

  The method for producing a sheet-like injection-molded simultaneous decorative article according to another aspect of the present invention includes arranging a decorative sheet on the inner surface of the individual molded article space portion of the mold according to the present invention, and After injecting molten resin into the molding space, the volume of the molding space is reduced, and after the injected molten resin is compressed and solidified by cooling, the mold is opened and the present invention is applied. It is a manufacturing method of a thin-plate injection molding simultaneous decorating product which takes out a thin-plate injection molding simultaneous decorating product.

  The present invention, preferred embodiments of the present invention, and constituent elements of the present invention described above can be implemented in combination as much as possible.

  The thin plate-like injection-molded simultaneous decorative article according to the present invention has a stress buffer part residue, so that residual stress is concentrated on the stress buffer part residue, and the average thickness is 0.6 to 1.5 mm. However, there is an effect that no residual stress remains in the individual molded product part. Therefore, it is possible to obtain a sheet-like injection-molded and simultaneously decorated product including an individual molded product portion having no residual stress and improved optical characteristics.

  The thin plate-like injection molding simultaneous decorating mold according to the present invention is suitable for manufacturing a thin plate-like injection molding simultaneous decorating product having no residual stress in the individual molded product portion.

  According to the method of manufacturing a thin plate-like injection-molded simultaneous decorative product according to the present invention, a thin plate-shaped injection-molded simultaneous decorative product having no residual stress in the individual molded product portion can be manufactured.

  Below, with reference to drawings, the thin-plate injection molding simultaneous decorating article concerning this invention is further demonstrated. The dimensions, materials, shapes, relative positions, etc. of the members and parts described in the embodiments of the present invention are not intended to limit the scope of the present invention to those unless otherwise specified. It is merely an illustrative example.

  FIG. 1 is an explanatory view of a sheet-like injection-molded simultaneous decorating article 11 according to the present invention. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ.

  The thin plate-like injection-molded simultaneous decorating article 11 includes a single individual molded part 51, a stress buffer part residue 41 and a gate mark 71, and the individual molded part 51 and the stress buffer part residue 41 are continuous. The thin plate-like injection-molded simultaneous decorating article 11 is manufactured by a thin-plate injection-molded simultaneous decorating die that employs a hot runner valve gate.

  The substantially semi-triangular pyramid-shaped stress buffer portion residue 41 is located between the individual molded product portion 51 and the gate mark 71. The individual molded product portion 51 has a thin plate shape and an average thickness of 0.6 mm to 1.5 mm. A part of the first decorating surface 61 of the individual molded product part 51 has a decorating part 81 that is simultaneously decorated by injection molding with a first decorating sheet that is a transfer sheet.

The stress buffer portion residue 41 has a thickness at least partially greater than the average thickness of the individual molded product portion. Thereby, it is possible to provide a volume sufficient to absorb the residual stress during solidification of the molten resin while suppressing an increase in the planar area. Since the plane shape of the stress buffer portion residue 41 is triangular, the molding resin is injected from the gate trace 71 near the corner thereof, and the stress buffer portion residue 41 is formed to flow substantially radially in the surface flow path.

  With reference to FIG.1 (b), the 1st decorating surface 61 of the individual molded product part 51 and the one surface 76 of the stress buffer part residue 41 form the same plane. In this way, when one surface of the thin plate-like injection-molded simultaneous decorative article is made the same plane, the positioning of the first decorative sheet at the time of injection-molding simultaneous decoration becomes easy, and the first decorative sheet is easily handled. Become.

  An individual molded product is obtained by cutting the individual molded product portion 51 from the thin plate-like injection-molded simultaneous decorated product 11 at a position indicated by an arrow 95 by router processing or the like.

  FIG. 2 is an explanatory diagram of a thin plate-like injection-molded simultaneous decorating article 11 according to another embodiment. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ.

  The thin plate-like injection-molded simultaneous decorative article 11 is a four-plate thin-plate injection-molded simultaneous decorative article including four individual molded product parts 51.

  The sheet-like injection-molded simultaneous decorative article 11 includes four individual molded product parts 51, a stress buffer part residue 41 and a gate mark 71, and a margin part 52a is interposed between the stress buffer part residue 41 and the individual molded product part 51. In addition, there are margin portions 52 in the other periphery of the individual molded product portion 51. The margin portion 52 a is a passage of molding resin that connects the stress buffer portion residue 41 and the individual molded product portion 51. The margin portion 52 is a portion of the molded resin passage that connects the individual molded product portion 51 and the individual molded product portion 51 and the portion surrounding the individual molded product portion 51. The margin portion 52a and the margin portion 52 are portions that are not included in the individual molded product portion. The four individual molded product parts 51 are arranged around the gate mark 71. A part of the stress buffer part residue 41 exists between each individual molded part 51 and the gate mark 71.

Since the stress buffer portion residue 41 has a circular planar shape, a molding resin is injected from the gate mark 71 at the center point thereof, and the stress buffer portion residue 41 flows substantially radially in the surface flow path. The thin plate-like injection-molded simultaneous decorating article 11 is manufactured by a thin-plate injection-molded simultaneous decorating die using a hot runner valve gate. The stress buffer portion residue 41 has a substantially conical shape, and the thickness thereof is larger than the thickness of the individual molded product portion. In addition, the thickness of the margin part 52a and the margin part 52 is equal to the thickness of the individual molded product part 51 or 0.3 mm smaller than the individual molded product part at the maximum.

  A part of the first decorative surface 61 and included in the individual molded product part 51 includes a decorative part 81, which is simultaneously decorated by injection molding with a first decorative sheet which is a transfer sheet. It is. The 1st decorating sheet used what has four decorating parts in one sheet.

  By separating the individual molded product portion 51 from the thin plate-like injection-molded simultaneous decorated product 11 by router processing or the like, four individual molded products are obtained.

  FIG. 3 is an explanatory view of a thin plate-like injection-molded simultaneous decorating article 11 according to still another embodiment. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ.

  The thin plate-like injection-molded simultaneous decorative article 11 is a four-sheet thin-plate injection-molded simultaneous decorative article including four individual molded product parts 51.

  The sheet-like injection-molded simultaneous decorative article 11 includes four individual molded product parts 51, a stress buffer part residue 41 and a gate mark 71. Between the two individual molded product parts 51 and the gate mark 71 on the gate side, a stress buffer part residue 41 exists. Further, a margin portion 52 a is interposed between the two individual molded product portions 51 and the stress buffer portion residue 41. Margin portions 52 also exist in the other periphery of the individual molded product portion 51. The thin plate-like injection-molded simultaneous decorating article 11 is manufactured by a thin-plate injection-molded simultaneous decorating die that employs a hot nozzle and a side gate method. In the figure, 78 is a sprue residue.

Since the planar shape of the stress buffering portion residue 41 is substantially triangular, the molding resin is injected from the flow channel portion in the vicinity of the corner of the stress buffer portion residue 41 and flows substantially radially in the surface flow channel. Most of the thickness of the stress buffer portion residue 41 is thicker than the thickness of the individual molded product portion 51, but in the vicinity of the margin portion 52a, the thickness is 0.2 mm thinner than the thickness of the individual molded product portion 51. . In addition, the thickness of a part of the margin portion 52a is 0.2 mm thinner than the thickness of the individual molded product portion 51.

  A part of the first decorative surface 61 and included in the individual molded product part 51 has a decorative part 81, which is simultaneously decorated by injection molding with a first decorative sheet. The 1st decorating sheet used what has four decorating parts in one sheet.

  By separating the individual molded product portion 51 from the thin plate-like injection-molded simultaneous decorated product 11 by router processing or the like, four individual molded products are obtained.

  FIG. 4 is an explanatory view of a sheet-like injection molded simultaneous decorating article 11 according to another embodiment. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ.

  The thin plate-like injection-molded simultaneous decorative article 11 is a four-sheet thin-plate injection-molded simultaneous decorative article including four individual molded articles 51.

The sheet-like injection-molded simultaneous decorative article 11 includes four individual molded product parts 51, a stress buffer part residue 41 and a gate mark 71, and a margin part 52a is interposed between the stress buffer part residue 41 and the individual molded product part 51. In addition, there are margin portions 52 in the other periphery of the individual molded product portion 51. The four individual molded product parts 51 are arranged around the gate mark 71. A portion of the stress buffer portion residue 41 exists between each individual molded product 51 and the gate mark 71. Since the stress buffer portion residue 41 has a substantially circular planar shape, the molding resin is injected from the gate trace 71 on one surface of the substantially center thereof and is formed by flowing substantially radially in the surface flow path. The thin plate-like injection molding simultaneous decorating article 11 is manufactured by a thin plate-like injection molding simultaneous decorating die using a hot nozzle and a direct gate system. In the figure, 78 is a sprue residue.

  Most of the thickness of the stress buffer portion residue 41 is thicker than the thickness of the individual molded product portion 51, but in the vicinity of the margin portion 52 a, the thickness is 0.2 mm thinner than the thickness of the individual molded product portion 51. Further, the thickness of the margin part 52 a is 0.2 mm thinner than the thickness of the individual molded product part 51. Furthermore, the thickness of the other margin part 52 is 0.2 mm thinner than the thickness of the individual molded product part 51.

  A part of the first decorative surface 61 and included in the individual molded product part 51 has a decorative part 81, which is simultaneously decorated by injection molding with a first decorative sheet. The 1st decorating sheet used what has four decorating parts in one sheet.

  By separating the individual molded product portion 51 from the thin plate-like injection-molded simultaneous decorated product 11 by router processing or the like, four individual molded products are obtained.

  The thin plate-like injection-molded simultaneous decorative article described above arranges the second decorative sheet in addition to the first decorative sheet in the molding space, and melted resin between the first decorative sheet and the second decorative sheet. It may be a thin plate-like injection-molded and simultaneously decorated product that is injected and decorated at the same time as molding.

  FIG. 5 is a cross-sectional explanatory diagram of a thin plate-like injection-molded simultaneous decorating product 11 that is decorated on both sides.

  The thin plate-like injection-molded simultaneous decorating article 11 includes a single individual molded part 51, a stress buffer part residue 41 and a gate mark 71, and the individual molded part 51 and the stress buffer part residue 41 are continuous. The thin plate-like injection-molded simultaneous decorating article 11 is manufactured by a thin-plate injection-molded simultaneous decorating die that employs a hot runner valve gate. The substantially triangular pyramid-shaped stress buffer portion residue 41 is located between the individual molded product portion 51 and the gate mark 71.

  A part of the first decorative surface 61 and included in the individual molded product part 51 has a decorative part 81, which is simultaneously decorated by injection molding with a first decorative sheet. Moreover, the 2nd decorating part 91 exists in the substantially whole surface of the 2nd decorating surface 8 of the separate molded article part 51, and this is the one decorated by injection molding simultaneously with the 2nd decorating sheet. The first decorative sheet and the second decorative sheet may both be transfer sheets, both may be insert sheets, the first decorative sheet may be a transfer sheet, and the second decorative sheet may be a combination of insert sheets. The 1 decorative sheet may be an insert sheet, and the second decorative sheet may be a combination of transfer sheets. Most of the stress buffer part residue 41 is thicker than the thickness of the individual molded product part, and the stress buffer part residue 41 is a part and the thickness is equal to the thickness of the individual molded part part.

  An individual molded product is obtained by cutting the individual molded product portion 51 from the sheet-like injection molded simultaneous decorating product 11 by router processing or the like.

  FIG. 6 is an explanatory view of a thin plate-like injection-molded simultaneous decorating article 11 according to another embodiment. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects RS.

  The thin plate-like injection-molded simultaneous decorative article 11 is a four-sheet thin-plate injection-molded simultaneous decorative article including four individual molded products 51a. The thin plate-like injection-molded simultaneous decorative article 11 is different from the thin-plate injection-molded simultaneous decorated article 11 shown in FIG. 2 only in the shape and size of the individual molded product portion 51a. Here, the difference will be mainly described.

  The individual molded product portion 51 a has a hole 66. The thickness of the peripheral portion of the hole 66 (indicated by the arrow 67) is 0.15 mm. The thickness (indicated by the arrow 68) of the individual molded product portion is 0.7 mm except for the hole 66 and the vicinity thereof.

  The thin plate-like injection-molded simultaneous decorative article 11 includes the thin-plate injection-molded simultaneous decorative article 11 shown in FIG. 2 in that it includes four individual molded product parts 51a, a stress buffer part residue 41, and a gate mark 71. It is the same. In FIG. 6, the same reference numerals are given to the same portions of the thin plate-like injection-molded simultaneous decorative article 11 in FIG. 2 as those of the thin-plate injection-molded simultaneous decorated article 11 in FIG. 2.

  The thin plate-like injection-molded simultaneous decorative article described above may be a thin-plate injection-molded simultaneous decorated article formed by compression molding. In compression molding, after injecting molten resin into the molding space part consisting of the individual molded product part space part and the stress buffering space part of the mold, the volume of the molding space part is reduced by performing a mold closing operation, etc. This is a production method for solidifying a resin.

  Then, the manufacturing method of a thin-plate injection molding simultaneous decorating article is demonstrated.

  FIG. 7 is an explanatory view of an example of an apparatus used in the method for manufacturing a thin plate-like injection-molded simultaneous decorative article. (A) is a plane explanatory view of the inner surface side of the A mold 21 (side facing the B mold 31), and (b) is a cross-sectional explanatory view of the apparatus.

  An individual molded product part space 2 and a stress buffering space 4 are formed between the A mold 21 and the B mold 31. The molding space portion 1 includes an individual molded product portion space portion 2 and a stress buffering space portion 4. The individual molded part space part 2 is a part where a thin plate-shaped individual molded part is molded, and its thickness is designed to be 0.6 mm or more and 1.5 mm or less when taken out as an individual molded part. Is done.

  A first decorative sheet 3 is disposed in the individual molded product part space 2. Moreover, in addition to the 1st decorating sheet 3, the 2nd decorating sheet may be arrange | positioned in the separate molded article part space part 2. FIG.

  The individual molded product part space 2 is formed between the first inner surface 22 that is the inner surface of the A mold 21 and the second inner surface 32 that is the inner surface of the B mold 31. The A mold 21 and the B mold 31 are clamped, and the molten resin is injected from the injection device 93 into the stress buffer space 4 through the gate 7. The molten resin is also introduced into the individual molded product part space 2 connected to the stress buffer space 4 through the stress buffer space 4. At this time, the molten resin is introduced between the first decorative sheet 3 and the first inner surface 22 arranged in the individual molded product part space 2, and the individual molded product part is molded and decorated.

  If the stress buffer space 4 is thickened, the area of the stress buffer space 4 occupying the inner surface of the mold can be reduced when the volume is the same, and therefore the area of the decorative sheet placed in the mold Therefore, the area of the 1st decorating sheet 3 can be made small, and the 1st decorating sheet 3 becomes economical. Even in multi-drawing, since the distance between the molded products can be reduced, the area of the first decorative sheet 3 can be reduced.

  The stress buffering space 4 may be provided in the A mold 21 by forming the inner surface of the A mold 21 in the recess, or may be provided in the B mold 31 by forming the inner surface of the B mold 31 in the recess. The inner surfaces of both the A mold 21 and the B mold 31 may be provided in the A mold 21 and the B mold 31 by forming recesses therein. If the second inner surface 32 of the B mold 31, the fourth inner surface 33 of the B mold 31, and the remaining inner surface 34 of the B mold 31 are made substantially flat, that is, the inner surface of the A mold 21 is formed into a recess. Forming and providing the stress buffering space 4 in the A mold 21 facilitates alignment of the first decorative sheet 3 and reduces the frequency of occurrence of twisting of the first decorative sheet 3. preferable.

  In addition to the individual molded product part space part 2 and the stress buffering space part 4, the molding space part 1 may include a space that forms a margin part in some cases.

  A step of further compressing the filled molten resin by reducing the volume of the molding space by further performing a mold closing operation after the resin injection may be added. After cooling, the A mold and the B mold are opened, and the simultaneously molded decorative molded product is taken out. When the first decorative sheet is a transfer sheet, the base sheet may be removed at the same time.

  One of the A mold 21 and the B mold 31 may be a fixed mold and the other a movable mold.

  Examples of the resin used for molding include general-purpose resins such as polystyrene resin, polyolefin resin, ABS resin, AS resin, and AN resin. Also, general-purpose engineering resins such as polyphenylene oxide / polystyrene resin, polycarbonate resin, polyacetal resin, acrylic resin, polycarbonate-modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, ultrahigh molecular weight polyethylene resin, polysulfone resin, Super engineering resins such as polyphenylene sulfide resin, polyphenylene oxide resin, polyarylate resin, polyetherimide resin, polyimide resin, liquid crystal polyester resin, and polyallyl heat-resistant resin can also be used.

  In the thin plate-like injection-molded simultaneous decorative article described above, the stress buffer part residue is more preferably thicker than the thickness of the individual molded part in all or most of the stress buffer part residue. The area of the stress buffer space occupied on the inner surface of the mold can be made smaller, the distance between the molded products can be made smaller, and therefore the area of the decorative sheet arranged in the mold can be made smaller. Because.

  A thin plate-like injection-molded simultaneous decorative article described below was produced. The sheet-like injection-molded decorative product has an outer size of 135 × 110 mm, and four individual molded product parts for a mobile phone window having an average thickness of 0.6 mm and a finished size of 42.4 × 51.79 mm are arranged. The outer peripheral portion of one surface of the individual molded product portion has a first decorative surface decorated with a first decorative sheet that is a transfer sheet. The thin plate-like injection-molded simultaneous decorative article has a cylindrical stress buffer portion residue having a radius of 15 mm from the center of the gate.

  The gate method used for manufacturing the thin plate-like injection-molded simultaneous decorating product is a direct gate method using a hot nozzle manufactured by Simventive. The conditions for the simultaneous injection molding decoration are those in which a molten resin of acrylic resin is injected at an injection speed of 200 mm / second and a mold temperature of 60 ° C. After injecting the molten resin into the molding space and the stress buffering space of the mold, a mold closing operation was further performed, and a thin plate-like injection-molded decorative product was obtained through a compression molding process for reducing the volume of the molding space.

  The obtained sheet-like injection-molded and simultaneously decorated product was cut out by router processing to obtain a cellular phone window part as an individual molded product. The obtained individual molded article had no distortion due to residual stress in the window portion and no ink flow in the decorative portion.

  The individual molded product separated from the thin plate-like injection-molded simultaneous decorative product according to the present invention can be used for a member including a display window portion of an optical product such as a mobile phone.

It is explanatory drawing of the thin plate-shaped injection molding simultaneous decorating article 11. FIG. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ. It is explanatory drawing of the thin plate-shaped injection molding simultaneous decorating article 11. FIG. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ. It is explanatory drawing of the thin plate-shaped injection molding simultaneous decorating article 11. FIG. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ. It is explanatory drawing of the thin plate-shaped injection molding simultaneous decorating article 11. FIG. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects PQ. It is cross-sectional explanatory drawing of the thin-plate injection molding simultaneous decorating article 11 by which the both sides decoration was carried out. It is explanatory drawing of the thin plate-shaped injection molding simultaneous decorating article 11. FIG. (A) is plane explanatory drawing, (b) is sectional drawing in the surface which connects RS. It is explanatory drawing of an example of the apparatus used for the manufacturing method of a thin-plate injection molding simultaneous decorating article. (A) is plane explanatory drawing by the side of the inner surface of A metal mold | die 21, (b) is sectional explanatory drawing of an apparatus.

Explanation of symbols

1 Molding space
2 Individual molding part space part 3 1st decorating sheet 4 Stress buffering space part 7 Gate 8 2nd decorating surface 11 Sheet-like injection molding simultaneous decorating product 21 A mold 22 1st inner surface 23 3rd inner surface 31 B Mold 32 Second inner surface 33 Fourth inner surface 41 Stress buffer portion residue 51 Individual molded product portion 51a Individual molded product portion 52 Margin portion 52a Margin portion 61 First decorative surface 66 Hole 71 Gate trace 81 Decorating portion 91 First 2 decoration department

Claims (8)

Including single or multiple individual molded parts, stress buffer residues and gate marks,
There is a stress buffer part residue between at least one of the individual molded part and the gate mark,
The individual molded product part has a first decorative surface that is thin and has a thickness of 0.6 mm to 1.5 mm and is decorated on one surface using the first decorative sheet. ,
The stress buffer residue is at least the thickness of the portion is thicker than the thickness of the individual formed molded article unit,
The planar shape of the stress buffer portion residue is formed by molding resin flowing radially from the gate trace toward the individual molded product portion in a plan view, and the molding resin solidifies.
Thin-plate injection-molded decorative item.
2. The sheet-like injection-molded simultaneous decorating product according to claim 1, wherein the first decorative surface of the individual molded product portion and the front surface or the back surface of the stress buffer portion residue are the same plane.
  The sheet-like injection-molded simultaneous decorating product according to any one of claims 1 to 2, wherein the other decorating product part has a second decorating surface decorated using a second decorating sheet.   The sheet-like injection molded simultaneous decorative article is manufactured through a step of compressing the injected molten resin by reducing the volume of the molded space after injecting the molten resin into the molding space of the mold. The thin-plate injection molding simultaneous decorating product according to any one of claims 1 to 3.   An individual molded article separated from the thin plate-like injection-molded simultaneous decorated article according to any one of claims 1 to 4.   5. A molding space portion including a single or a plurality of individual molded product portion space portions and a stress buffering space portion between injection molding simultaneous decorating molds arranged to face each other, A mold for simultaneous decoration of thin plate injection molding used for obtaining the decorative product of thin sheet injection molding described in 1.   A decorative sheet is disposed on the inner surface of the space part of the individual molded product part of the mold according to claim 6, molten resin is injected into the molding space part of the mold, cooled and solidified, and then the mold is opened. And the manufacturing method of the thin-plate injection molding simultaneous decorating product which takes out the thin-plate injection molding simultaneous decorating product in any one of Claims 1 thru | or 3. After disposing a decorative sheet on the inner surface of the individual molded product part space part of the mold according to claim 6 and injecting molten resin into the molding space part in the mold, the volume of the molding space part is increased. The sheet-shaped injection molding simultaneous decoration which takes out the thin-plate injection-molding simultaneous decorating article of Claim 4 after reducing and shrinking through the process of compressing the injected molten resin, cooling and solidifying, and opening the mold A method for manufacturing decorative products.

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