JP2005088315A - Injection mold for in-mold decoration and manufacturing method of in-mold injection-molded decorative product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that slackening is easy to occur in a decorative film to generate small wrinkles in the decorative film accompanied by the flow of a molten resin when the molding space parts of a mold are filled with the molten resin in an in-mold decorating injection molding method using the mold having a plurality of the molding space parts. <P>SOLUTION: The mold is constituted of an A-mold 1 and a B-mold 2 both of which comprise a plurality of molding space parts communicating with each other and the auxilary molding space parts for surrounding the respective molding space parts and is constituted so as to fill the molding space parts with a molten molding resin through the auxiliary molding space parts and a gate 14 is provided to the central part of the inner surface of the A-mold while partitioning protruded parts 23 for surrounding the molding space parts of the auxiliary molding space parts are provided to the surface of the recessed part of the B-mold. This mold is used to perform in-mold decoration by injection molding. Since the molding space parts are filled with the molten resin while pressing the decorative film 5 by the partitioning protruded parts and stretching the decorative film, this manufacturing method has an effect for making small wrinkles hard to occur in the decorative film surrounded by the partitioning protruded parts. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  Conventionally, a method of producing a resin molded product by injection molding in which a molten resin is injected from an injection hole into a space portion between a male mold and a female mold disposed to face each other, The male mold and the female mold are provided in parallel with a plurality of molding space portions that determine the shape of a molded product formed between the two molds when the two molds are combined. An auxiliary space part that communicates with the molding space part and the injection hole and surrounds the entire circumference of the plurality of molding space parts is provided, and both molds are combined to form a molding space part and an auxiliary space part between the two molds. And a first step of arranging a foil body to be transferred on the mold side opposite to the mold in which the injection port is formed in the molding space, and the molten resin in the auxiliary space A second step of injecting from the injection hole, and the resin in each of the plurality of molding spaces. There was the invention of Patent Document 1 that the third step and the foil transfer method of a resin molded article by injection molding, characterized in that it comprises injecting through between portions.

  According to the present invention, the resin can flow into the molding space from any direction of the molding space, and even if the molding space is thin, the resin can easily flow uniformly into the molding space. Therefore, injection molding of a thin molded product is possible, and transfer of the metal foil to the molded product can be performed by a single process. Further, since the resin can be introduced from all directions, the injection pressure (stress) applied to the resin is uniform throughout, and the resin density and the like can be uniform.

JP 2003-181870 A

  However, the simultaneous injection molding decoration method is subject to dragging load caused by the flow of the molded resin melted on the decorative film, and is liable to be loosened. Since the resin flows from the direction into the molding space, there is a problem that the slack is concentrated in the molding space and a small wrinkle is generated in the molding space.

  Therefore, the present inventor has adopted the following configuration in order to solve the above problems. The first aspect of the present invention comprises a plurality of molding space portions communicating with each other and auxiliary molding space portions surrounding each molding space portion, and the molten molding resin fills the molding space portions via the auxiliary molding space portions. An injection molding simultaneous mold comprising a mold body composed of an A mold and a B mold, and a gate provided at the center of the inner surface of the A mold, and auxiliary molding of the concave surface of the B mold A mold for simultaneous decoration for injection molding, characterized in that a partition convex portion surrounding the molding space portion is provided in the space portion.

  The second aspect of the present invention is an injection molding simultaneous decorating mold in which a suction pin is provided on the partition convex portion.

In the third aspect of the present invention, the average cross-sectional area of the molding space portion is S ₁ (mm ² ), the average thickness of the molding space portion is T ₁ (mm), and the average cross-sectional area of the auxiliary molding space portion is S ₂ (mm ² ) When the average thickness of the auxiliary molding space portion is T ₂ (mm), there is a relationship of S ₁ ≦ 2 × S ₂ and 2 × T ₁ ≦ T ₂ . It is a mold.

  The fourth aspect of the present invention is an injection molding simultaneous decorating mold in which a transverse groove is provided on a reference surface on the outer periphery of the auxiliary molding space.

  In a fifth aspect of the present invention, a decorative film is set between the A mold and the B mold, the mold is clamped, and molding is performed in a molding space formed by the decorative film and the A mold. This is a method for manufacturing an injection-molded and simultaneously decorated product in which a resin is injected from a gate provided at the center of the inner surface of the A mold and then the molded resin is solidified to obtain an injection-molded and decorated product.

  The mold for simultaneous injection molding decoration of the present invention is characterized in that a partition convex portion surrounding the molding space portion is provided in the auxiliary molding space portion of the concave surface of the B die. Therefore, the molten molding resin is filled in the molding space while holding the decorative film with the partition convex part and stretching the decorative film, so the decorative film surrounded by the partition convex part is small. There is an effect that is difficult to occur.

  Moreover, the manufacturing method of the injection-molding simultaneous decorating product of this invention sets the decorating film to the said injection molding simultaneous decorating metal mold | die, clamps, and the molding space formed by a decorating film and A metal mold | die After the molding resin melted in the part is injected from the gate provided at the center of the inner surface of the A mold, the molding resin is solidified to obtain an injection molded simultaneous decorating product. Therefore, there is an effect that it is possible to take a large number of injection-molded and simultaneously decorated items without a small flaw.

  Hereinafter, the present invention will be described in detail with reference to the drawings. 1 to 4 are longitudinal sectional views conceptually showing the injection molding simultaneous decorating mold and the injection molding simultaneous decorating method of the present invention, and show the AA line in FIGS. 5 and 7. FIG. 5: shows the top view of A metal mold | die 1 of the injection molding simultaneous decorating metal mold | die which concerns on this invention. FIG. 6 is a cross-sectional view taken along line BB to DD in FIG. FIG. 7 shows a plan view of the B mold 2 of the simultaneous injection molding decorative mold according to the present invention. FIG. 8 shows a cross-sectional view of the FF line and the GG line of FIG. FIG. 9 shows a plan view of the simultaneous injection-molded decorative article of the present invention. FIG. 10 is a plan view showing a state after the simultaneous injection-molded decorative product of FIG. 9 is cut into a product molded product and an auxiliary molded product.

  The injection molding simultaneous decorating mold of the present invention is a pair of opposing injection molding simultaneous decorating molds, and a decorative film 5 is set on the side of the B mold 2 (see FIG. 1) and the mold is clamped. The molding resin 4 is injected through the gate 14, and the molding space 3 formed between the decorative film 5 and the B mold 2 after clamping is a plurality of molding spaces 31 that communicate with each other. And auxiliary molding space portions 33 surrounding each molding space portion 31, the auxiliary molding space portion 33 is filled with molten molding resin 4 (see FIG. 2), and then the molding space portion 31 is filled with the molding resin 4. After the mold is cooled and solidified (see FIG. 3), the A mold 1 and the B mold 2 are opened, and the injection molding simultaneous decorative article 10 is released from the A mold 1 by the ejector pin 24. Yes (see FIG. 4). And the obtained injection-molding simultaneous decoration 10 (refer FIG. 9) is cut | disconnected later into the product molded product 30 and the auxiliary molded product 40 (refer FIG. 10).

  As shown in FIGS. 5 and 6, the A mold 1 is formed in a rectangular shape as in the prior art, and includes a reference surface 11 that directly contacts the B mold 2 at the four peripheral ends thereof. In the inner part surrounded by the reference surface 11, a recess 12 having a shape suitable for the outer shape of the molded product and a laterally extending groove 15 are formed. An injection port for the gate 14 is formed in the vicinity of the upper, lower, left, and right centers of the A mold 1, and the molding resin 4 is injected through the gate 14.

  On the other hand, as shown in FIGS. 7 and 8, the B mold 2 is formed in a square shape having a width and height corresponding to the A mold 1, and is a flat reference surface that is in direct contact with the A mold 1. 21 is provided. In the inner part surrounded by the reference surface 21, a recess 22 having a shape suitable for the outer shape of the molded product and a laterally extending groove 15 are formed.

  Moreover, the partition convex part 23 is formed in the auxiliary | assistant shaping | molding space part 33 surrounding the shaping | molding space part 31 added to the A metal mold | die 1 side in the recessed part 22, and the product molded product 30 is decorated without a small basket.

  After the molten molding resin 4 is filled in the auxiliary molding space portion 33, the molten molding resin 4 enters the molding space portion 31 beyond the partition convex portion 23 provided between the auxiliary molding space portion 31 and the molding space portion 31. In this case, the molten molding resin 4 is filled in the molding space 31 while the decorative film 5 is pressed by the partition projections 23 and stretched. Therefore, a small wrinkle is unlikely to occur in the decorative film 5 surrounded by the partition convex portions 23.

  The formation position of the partition convex part 23 may be provided at a position in contact with the molding space part 31 or may be provided at a distant position. That is, the molding space portion 3 surrounded by the partitioning convex portion 23 may be only the molding space portion 31 or may include the molding space portion 31 and the auxiliary molding space portion 33. Moreover, the partition convex part 23 may be provided continuously like a ring | wheel, and may be provided discontinuously.

  Moreover, in this invention, it is good also as a structure by which the suction pin 25 is provided in the partition convex part 23 in the said metal mold | die for simultaneous injection molding. The suction pin 25 has a function of sucking and fixing the decorative film 5 to the B mold, and air and dust remaining between the decorative film 5 and the B mold 2 and the base sheet 51 of the decorative film 5. There is a function to remove the generated gas. The shape of the suction pin 25 may be a square shape such as a block in addition to a cylindrical shape. The suction pin 25 may also be provided in the molding space portion 31 surrounded by the partition convex portion 23.

Further, the present invention consists of an auxiliary molding space portion 33 surrounding a plurality of molding spaces 31 and each of the molding space 31 communicating with each other, the average cross-sectional area of the molding space 31 S _{1 (mm} ^2), When the average thickness of the molding space 31 is T ₁ (mm), the average cross-sectional area of the auxiliary molding space 33 is S ₂ (mm ² ), and the average thickness of the auxiliary molding space 33 is T ₂ (mm), 2 It is preferable to use an injection molding simultaneous decorating mold having a relationship of × S ₁ ≦ S ₂ and 2 × T ₁ ≦ T ₂ .

  The average cross-sectional area of the auxiliary molding space 33 is set to be twice or more the average cross-sectional area of the molding space 31 and the average thickness of the auxiliary molding space 33 is set to be twice or more the average thickness of the molding space 31. Thus, in order to obtain a mold for simultaneous injection molding that can be filled with the molding resin 4 reliably melted first into the auxiliary molding space 33 and then filled into the molding space 31 via the auxiliary molding space 33. It is. These numerical values were set from the test results shown in Table 1.

※所望の成形樹脂の流れの可否は、溶融した成形樹脂が、補助成形空間部を介して成形空間部に充填した場合に○、そうでない場合に×とする。

* Whether or not the flow of the desired molding resin can be determined is ◯ when the molten molding resin is filled into the molding space through the auxiliary molding space, and x when it is not.

  Moreover, in this invention, it is good also as a structure by which the horizontal groove | channel 15 is provided in the reference surface of the outer periphery of the auxiliary | assistant shaping | molding space part 33 in the said injection molding simultaneous decorating metal mold | die.

  Even if the molding space portion 31 surrounded by the partition convex portion 23 is formed without a small wrinkle, the outer side of the partition convex portion 23, in particular, the auxiliary molding space portion 33 is still in a state where a small wrinkle is easily generated. If the position of the decoration of the simultaneous injection-molded decorative product 10 may be slightly shifted and the laterally extending groove 15 is provided there, the slackness of the decorative film 5 generated in the auxiliary molding space 33 is alleviated by the laterally extending groove 15. This is because the tension of the entire decorative film 5 in the molding space 31 is also kept moderate. Therefore, it is possible to prevent the position of the decoration of the injection-molded simultaneous decoration product 10 from being shifted by the lateral groove 15.

  The laterally extending groove 15 may be provided continuously like a ring or may be provided discontinuously. However, it is preferable that the laterally stretched groove is provided on the entire outer periphery of the auxiliary molding space 33 like a ring because the effect becomes uniform in any direction.

  Moreover, it is preferable to provide the laterally extending groove 15 in a range of a depth of 0.5 to 5 mm and a width of 0.5 to 7 mm. This is because if the depth or width is too small, the effect of alleviating the slack of the decorative film 5 is weak, and if the depth or width is too large, the strength of the mold is reduced.

  Further, the lateral groove 15 may be provided in both the A mold 1 and the B mold 2 or may be provided in only one of them. Moreover, when providing in both, you may make depth and width differ.

  After the molding resin 4 is filled and solidified, the B mold 2 is separated from the A mold 1 and the simultaneous injection molded decorative article 10 is released from the A mold 1 (see FIG. 4). Release of the simultaneous injection molded decorative article 10 is performed by a plurality of ejector pins 24.

  The obtained injection molding simultaneous decorative article 10 is cut into a predetermined size and divided into a product molded article 30 and an auxiliary molded article 40 (see FIG. 10). Cutting methods include cutting, laser processing, Thomson processing, die press processing, engraving blade processing (including thermal processing), and high-frequency processing.

  Next, the decorative film 5 and the molding resin 4 used in the present invention will be described. The decorative film 5 used in the present invention is formed of a base sheet 51 and a decorative layer 50, and the decorative layer 50 includes a pattern layer 52, an adhesive layer 53, and the like (see FIG. 11).

  As the base sheet 51, a single layer film selected from polycarbonate resin, polyamide resin, polyimide resin, polyester resin, acrylic resin, olefin resin, urethane resin, acrylonitrile butadiene styrene resin, etc., or 2 selected from the above There are laminated films or copolymer films made of more than one kind of resin.

  As thickness of the base material sheet 51, 5-500 micrometers is preferable. If the sheet is less than 5 μm, handling at the time of mold setting is poor and the molding process becomes unstable. If the sheet exceeds 500 μm, the sheet is too rigid.

  An easy-adhesion layer may be formed on the base sheet 51 so that the decorative layer 50 is firmly attached. Examples of the material for the easy adhesion layer include polyester resins, acrylic resins, olefin resins, and urethane resins. As a method of providing the easy-adhesion layer, any of various coating methods may be used in addition to general-purpose printing methods such as gravure printing, screen printing, and offset printing.

  On the base sheet 51, a pattern layer 52 such as a character, a geometric pattern, or a solid is formed. Examples of the material of the pattern layer 52 include acrylic resin, nitrified cotton resin, polyurethane resin, chlorinated rubber resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, polyester resin, and epoxy resin. Although it can mention, it does not specifically limit.

  The pattern layer 52 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 film thickness of the pattern layer 52 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.

  As a method of providing the pattern layer 52 in the whole surface or in a pattern, metal film formation such as gravure printing, screen printing, offset printing method, etc., tampo printing, painting, various coating methods, vapor deposition, ion plating, sputtering method, etc. There are laws.

  The adhesive layer 53 has an action of joining the decorative film 5 and the molding resin 4. The material of the adhesive layer 54 is acrylic resin, nitrified cotton resin, polyurethane resin, chlorinated rubber resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, polyester resin, epoxy resin, polycarbonate resin. It is preferable to use a resin, an olefin resin, an acrylonitrile butadiene styrene resin, or the like.

  The thickness of the adhesive layer 53 is preferably 0.5 to 50 μm. If the film thickness is less than 0.5 μm, there is a problem that sufficient adhesion cannot be obtained, and if it is more than 50 μm, there is a problem that it is difficult to dry after printing. The method for forming the adhesive layer 54 may be a general-purpose printing method such as gravure printing, offset printing, or screen printing, or any method such as painting, dipping, or reverse coater.

  When only the decorative layer 50 is bonded to the molding resin 4, a release layer 54 may be provided between the base sheet 51 and the pattern layer 52 (see FIG. 12). Alternatively, a base sheet having a release property 55 may be provided by providing a release layer on the base sheet 51.

  The release layer 54 is made of acrylic resin, nitrified cotton resin, polyurethane resin, chlorinated rubber resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, polyester resin, epoxy resin, polycarbonate resin. It is preferable to use a resin, an olefin resin, an acrylonitrile butadiene styrene resin, or the like.

  The thickness of the release layer 54 is preferably 0.5 to 50 μm. If the film thickness is less than 0.5 μm, there is a problem that sufficient adhesion cannot be obtained, and if it is more than 50 μm, there is a problem that it is difficult to dry after printing. The release layer 55 may be formed by a general-purpose printing method such as gravure printing, offset printing, or screen printing, or any method such as painting, dipping, or reverse coater.

  The release layer 55 is made of acrylic resin, nitrified cotton resin, polyurethane resin, chlorinated rubber resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, polyester resin, epoxy resin, polycarbonate. It is preferable to use a resin, an olefin resin, an acrylonitrile butadiene styrene resin, or the like.

  The thickness of the release layer 55 is preferably 0.5 to 50 μm. If the film thickness is less than 0.5 μm, there is a problem that sufficient adhesion cannot be obtained, and if it is more than 50 μm, there is a problem that it is difficult to dry after printing. The method for forming the release layer 55 may be a general-purpose printing method such as gravure printing, offset printing, or screen printing, or any method such as painting, dipping, or reverse coater.

  As the molding resin 4, a thermoplastic resin such as acrylic resin, polycarbonate resin, styrene resin, polyamide resin, noryl resin, polyester resin, olefin resin, urethane resin, acrylonitrile butadiene styrene resin is used. Can do.

  The present invention relates to a mold for simultaneous injection molding decoration and a method for manufacturing an injection molded simultaneous decoration product. The mold for simultaneous injection-molding decoration and the method for producing a simultaneous decoration for injection-molding according to the present invention are particularly suitable for taking a large number of simultaneously-decorated products for injection molding.

All drawings are examples of injection molding simultaneous decorating molds and injection molding simultaneous decorating methods according to the present invention, injection molding simultaneous decorating products obtained by using these, and decorating films used for these. Show.
It is sectional drawing of the metal mold | die for simultaneous injection molding decoration which shows the state which inserted the decorating film between A metal mold | die and B metal mold | die. It is sectional drawing of the metal mold | die for simultaneous injection molding decorating which shows a mold clamping state. It is sectional drawing of the metal mold | die for simultaneous injection molding decoration which shows the state which inject | poured the molding resin. It is sectional drawing of the metal mold | die for simultaneous injection molding decorating which shows a mold open state. It is a top view of A mold of an injection molding simultaneous decoration mold. FIG. 6 is a cross-sectional view taken along a line BB, a cross-sectional view taken along a line CC, and a cross-sectional view taken along a line DD in FIG. 5. It is a top view of B metal mold | die of an injection molding simultaneous decorating metal mold | die. FIG. 8 is a cross-sectional view taken along line FF and a cross-sectional view taken along line GG in FIG. 7. It is a top view of the injection-molding simultaneous decorating article obtained using the injection molding simultaneous decorating mold and the injection-molding simultaneous decorating method. It is a top view of the state which isolate | separated the injection molding simultaneous decorating goods shown in FIG. 9 into the product molded product and the auxiliary molded product. It is sectional drawing of a decorating film. It is sectional drawing of a decorating film.

Explanation of symbols

1 A mold
2 B mold
4 Molding resin
DESCRIPTION OF SYMBOLS 5 Decorating film 10 Injection molding simultaneous decorating product 14 Gate 15 Horizontally stretched groove 16 Partition groove 21 Reference surface 23 Partition convex part 24 Ejector pin 25 Suction pin 26 Suction hole or Suction convex part 30 Product molded product 31 Molding space part 33 Auxiliary molding space Part 40 Auxiliary molded product 50 Decorating layer 51 Base sheet 52 Picture layer 53 Adhesive layer 54 Peeling layer 55 Mold release layer

Claims (5)

A mold and B mold, each of which includes a plurality of molding spaces communicating with each other and auxiliary molding spaces surrounding each molding space, and in which molten molding resin can be filled into the molding space via the auxiliary molding spaces An injection molding simultaneous mold comprising a mold body composed of a mold and a gate provided at the center of the inner surface of the A mold, wherein the molding space is surrounded by the auxiliary molding space on the concave surface of the B mold A mold for simultaneous decorating of injection molding, characterized in that a partition convex portion is provided. The mold for simultaneous injection molding decoration according to claim 1, wherein a suction pin is provided on the partition convex portion. The average cross-sectional area of the molding space is S ₁ (mm ² ), the average thickness of the molding space is T ₁ (mm), the average cross-sectional area of the auxiliary molding space is S ₂ (mm ² ), and the auxiliary molding space is _3. The simultaneous injection molding process according to claim 1, wherein when the average thickness is T ₂ (mm), there is a relationship of 2 × S ₁ ≦ S ₂ and 2 × T ₁ ≦ T _2. Decoration mold. The mold for simultaneous injection molding decoration according to any one of claims 1 to 3, wherein a transverse groove is provided on a reference surface on an outer periphery of the auxiliary molding space. A molding space formed by setting the decorative film between the A mold and the B mold according to any one of claims 1 to 4 and clamping the mold, and the decorative film and the A mold. A method of manufacturing an injection-molded decorative product in which a molding resin melted in a part is injected from a gate provided in the center of the inner surface of the mold A, and then the molding resin is solidified to obtain an injection-molded decorative product.

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