JP2012040799A - Apparatus and method for molding resin and multilayered molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a multilayered molded product in a state of preventing the ink flow of an interposed decorative layer while maintaining heat resistance of a product surface layer.SOLUTION: The resin molding apparatus for forming the multilayered molded product 2 having a surface side resin layer 2A of which front and back sides are fastened by the decorative layer 1, and a back side resin layer 2B integrated with the back surface side of the surface side resin layer 2A includes a first fixed mold T1 molding the back side part of the surface side resin layer 2A, a movable mold U integrally molding the decorative layer 1 on the front and back sides and the surface side resin layer 2A between the first fixed mold T1 and it, a holding part 5 which can hold the surface side resin layer 2A to the movable mold U while molding it, a second fixed mold T2 integrally molding the back side resin layer 2B on the back surface side of the surface side resin layer 2A held to the movable mold U by the holding part 5, and a movement mechanism H freely moving the movable mold U from a position in correspondence with the first fixed mold T1 to a position in correspondence with the second fixed mold T2.

Description

  The present invention relates to a resin molding apparatus for forming a multilayer molded article, comprising: a front side resin layer sandwiched between front and back sides by a decorative layer; and a back side resin layer integrated on the back side of the front side resin layer; and a resin The present invention relates to a molding method and a multilayer molded article.

Conventionally, as this type of resin molding technology, the mold is clamped with the fixed mold in a state where the decorative layer is positioned along the molding surface of the first movable mold, and between the decorative layer and the fixed mold. A step of discharging a resin to form a back side resin layer integrated with the decorative layer is performed.
Next, a step of arranging the second movable mold in a state of facing the fixed mold in place of the first movable mold while the back side resin layer is supported on the fixed mold is performed.
Next, the decorative layer is positioned along the molding surface of the second movable mold, and the mold is clamped with the fixed mold, and the resin is placed between the decorative layer and the back side resin layer supported by the fixed mold. Is carried out to form a front side resin layer integrated with the decorative layer and the back side resin layer, and the front side resin layer sandwiched between the front and back sides and the back side of the front side resin layer A multilayer molded article provided with a backside resin layer to be integrated has been formed (for example, see Patent Document 1).

Japanese Patent No. 3472403 (FIGS. 1 to 3)

According to the conventional resin molding technique described above, a decorative layer (intervening decorative layer) sandwiched between the front-side resin layer is provided on the front-side surface of the previously formed back-side resin layer. Since the pattern layer is exposed, there is a risk that the ink of the pattern layer melts and ink flows due to the temperature of the molten resin for forming the front side resin layer discharged on the pattern layer. . This is a particular problem when the front resin layer is transparent because the intervening decorative layer can be seen through from the surface side.
In order to prevent this, it is conceivable to use a resin having a low melting temperature as the resin for forming the front side resin layer, but in that case, the heat resistance as the product surface layer is lowered, It is preferable to employ a resin having a high melting temperature.

  Accordingly, an object of the present invention is to provide a resin molding technique capable of forming a multilayer molded product in a state in which the ink flow of the intervening decorative layer is difficult to occur while eliminating the above-mentioned problems and maintaining the heat resistance of the product surface layer. By the way.

  1st characteristic structure of this invention is resin which forms the multilayer molded article provided with the front side resin layer by which the front and back were pinched | interposed by the decoration layer, and the back side resin layer integrated in the back surface side of the said front side resin layer A molding device, a first fixed mold for molding the back side portion of the front resin layer, and a movable mold for integrally molding the front and back decorative layers and the front resin layer between the first fixed mold, A holding part that can be held by the movable mold while the front side resin layer is molded, and a second fixing that integrally molds the back side resin layer on the back side of the front side resin layer held by the moving part by the holding part. A mold and a moving mechanism that can move the movable mold from a position corresponding to the first fixed mold to a position corresponding to the second fixed mold are provided.

According to the first characteristic configuration of the present invention, the first resin mold and the movable mold can be integrally formed with the front resin layer having the decorative layer on the front and back surfaces, and the front resin layer is formed by the holding portion. Can be held mobile. Further, the moving mechanism can move the front side resin layer held by the holding portion to a position corresponding to the second fixed type for each moving type, and subsequently, the back side resin layer is placed on the back side of the front side resin layer. It can be molded integrally to form a multilayer molded product.
Moreover, the transfer sheet for integrating the decorative layer with the resin layer is laminated on the base sheet in the order of the release layer, the pattern layer, and the adhesive layer, and when molding the front side resin layer, Integral molding is achieved with the adhesive layer positioned on the side that contacts the molten resin. Therefore, since the pattern layer is protected by the adhesive layer, even if a resin having a high glass transition point is used for the front side resin layer, the ink flow of the decorative layer hardly occurs. Therefore, a resin having a high glass transition point can be used for the front side resin layer, and a multilayer molded product having a high heat resistance of the product surface layer can be formed.
Furthermore, since the base sheet is made of, for example, a PET film having a thickness of about 25 to 50 μm, the molten resin (for example, ABS, PC, etc.) is obtained by the cooling effect (10 to 80 ° C.) of the mold in contact with the transfer sheet. / ABS) is 230-260 ° C., it is rapidly cooled at the time of contact, and the ink flow of the decorative layer hardly occurs.
Moreover, although the pattern layer is exposed to the back side resin layer side of the intervening decorative layer to which the back side resin layer to be molded later comes into contact, ink flow hardly occurs at the low glass transition point for the back side resin layer. Even if resin is used, the heat resistance of the surface of the multilayer molded product is hardly affected. Therefore, a resin having a low glass transition point can be used for the back side resin layer, and the ink flow of the intervening decorative layer can be made difficult to occur.
As a result of the above, a multilayer molded product can be molded in a state in which the ink flow of the intervening decorative layer is difficult to occur while maintaining the heat resistance of the surface resin layer.
In addition, since the decorative layer can be formed on the front and back of the front side resin layer first, the range of the decorative layer can be set regardless of the range of the back side resin layer that is integrally molded later, and the back side resin layer is not necessarily on the front side. There is no need to form the entire surface of the resin layer. As a result, although it is a multilayer molded product, the back side resin layer can be reduced to a minimum, for example, a rib or an engaging claw portion, and can be a thin product mostly composed of only the front side resin layer. As an example, it is possible to provide a molded article composed of a front side resin layer having a thickness of 1 mm or less, such as a liquid crystal panel or a battery cover of a cellular phone that requires a small thickness.

  The second characteristic configuration of the present invention is that the glass transition point of the second resin forming the back resin layer is set lower than that of the first resin forming the front resin layer.

  According to the second characteristic configuration of the present invention, while using a resin having a high glass transition point as the first resin, it is possible to form a multilayer molded product having a high heat resistance of the product surface layer. Since a resin having a glass transition point lower than that of the first resin is used, the second resin can be melted at a low temperature and discharged into the mold, and the ink flow of the intervening decorative layer that comes into contact can be hardly generated.

  According to a third characteristic configuration of the present invention, the holding portion is configured as a slide mold that is movable along a direction perpendicular to the movable mold clamping direction.

  According to the third characteristic configuration of the present invention, since the holding portion is constituted by a slide type that moves along a direction perpendicular to the moving mold clamping direction, the holding portion itself is not bulky and adopts a simple structure. Therefore, it is easy to reduce the apparatus cost.

  According to a fourth characteristic configuration of the present invention, the second fixed mold is provided with a compression molding means for pressurizing the molten resin after discharging the molten resin into the corresponding cavity space.

  According to the fourth characteristic configuration of the present invention, it is possible to ensure a long initial distance from the gate to the interposed decorative layer, and to reduce the influence of temperature and pressure on the interposed decorative layer to prevent ink flow. be able to.

  A fifth characteristic configuration of the present invention is a resin molding that forms a multilayer molded article including a front side resin layer sandwiched between front and back layers and a back side resin layer integrated on the back side of the front side resin layer. In this method, the mold is clamped in a state where the decorative layers are positioned separately along the molding surfaces of the first fixed mold and the movable mold, and the first resin is discharged between the decorative layers. The front side resin layer integrated with the decorative layer is molded, separated from the first fixed mold while the front side resin layer is held by the movable mold, and the second fixed mold is located on the back side of the front side resin layer. The mold is moved and clamped, and a second resin having a glass transition point lower than that of the first resin is discharged to the back side of the front resin layer so that the back resin layer is integrated with the front resin layer. There is a place to mold.

According to the fifth characteristic configuration of the present invention, in the transfer sheet that is aligned with each of the first fixed mold and the movable mold, the adhesive layer is positioned in a state of protecting the pattern layer on the surface on the contact side with the molten resin. Therefore, even if a resin having a high glass transition point is used as the first resin, ink flow in the decorative layer can be prevented. Moreover, since the front side resin layer shape | molded with the 1st resin with a high glass transition point is excellent in heat resistance, the improvement of the surface heat resistance as a multilayer molded article can be aimed at.
Furthermore, since the first resin having a high glass transition point is basically accompanied by polymerization of the resin, it leads to an improvement in mechanical strength.
On the other hand, since the front side resin layer molded by the first fixed mold and the movable mold can be moved from the first fixed mold to the second fixed mold while being held by the movable mold, the back side resin layer can be continuously molded. The loss time can be reduced and a multilayer molded product can be formed efficiently.
In addition, since the front side decorative layer is also moved while being held in a movable manner, the front side decorative layer is prevented from entering dust from the outside environment and can prevent the occurrence of defective biting of dust.
Since the back side resin layer in contact with the intervening decorative layer on the back side of the front side resin layer is molded using the second resin having a glass transition point lower than that of the first resin, the thermal effect on the pattern layer of the intervening decorative layer is affected. The ink flow can be prevented and the ink flow can be prevented.
As a result of the above, a multilayer molded product can be molded in a state in which the ink flow of the intervening decorative layer is difficult to occur while maintaining the heat resistance of the surface resin layer.
In addition, since the decorative layer is formed on the front and back of the front side resin layer first, the range of the decorative layer can be set regardless of the range of the back side resin layer that is molded integrally later. There is no need to form the entire surface of the resin layer. As a result, although it is a multilayer molded product, the back side resin layer can be reduced to a minimum, for example, a rib or an engaging claw portion, and can be a thin product mostly composed of only the front side resin layer. As an example, it is possible to provide a molded article composed of a front side resin layer having a thickness of 1 mm or less, such as a liquid crystal panel or a battery cover of a cellular phone that requires a small thickness.

  According to a sixth characteristic configuration of the present invention, after the second resin is discharged into the cavity space between the second fixed mold and the movable mold, the molten resin is pressurized from the second fixed mold side to perform compression molding. There is a place to do.

According to the sixth characteristic configuration of the present invention, in molding the back side resin layer, a long initial distance from the gate to the intervening decorative layer can be secured, and the temperature and pressure of the molten resin on the intervening decorative layer can be secured. The influence of the ink can be reduced to prevent ink flow.
Furthermore, since the resin strength can be improved by compression molding, the product can be made thinner. For example, even a product having a thickness of 0.5 to 0.7 mm can be provided with strength.

  The seventh characteristic configuration of the present invention is a multilayer molded article comprising a front side resin layer sandwiched between front and back layers and a back side resin layer integrated on the back side of the front side resin layer, The first resin constituting the surface resin layer has a higher glass transition point than the second resin constituting the back resin layer.

According to the seventh characteristic configuration of the present invention, in addition to being able to easily mold a multilayer molded product by the resin molding apparatus having the first to sixth characteristic configurations of the present invention and the resin molding method. Thus, the multilayer molded product can be molded in a state where the ink flow of the intervening decorative layer is hardly generated while maintaining the heat resistance of the surface resin layer.
Moreover, since the design, color, etc. of both decoration layers can be comprised beautifully, it can be set as the multilayer molded article with rich aesthetics which decorated with those decoration layers through a transparent surface layer resin layer, for example. .

  The eighth characteristic configuration of the present invention is a multilayer molded article comprising a front side resin layer sandwiched between front and back decoration layers, and a back side resin layer integrated on the back side of the front side resin layer, The said front side resin layer and the said back side resin layer are comprised with transparent resin, and it exists in the place which provided the decorating layer in the back surface of the said back side resin layer.

  According to the eighth characteristic configuration of the present invention, the pattern and color of the three decorative layers can be configured beautifully, and a multilayer molded product rich in aesthetics with a depth and a three-dimensional appearance can be obtained.

Schematic cross section showing resin molding equipment Schematic cross section showing resin molding equipment Schematic cross section showing resin molding equipment Schematic cross section showing resin molding equipment Sectional view showing the holding part Explanatory drawing showing multilayer molded product Sectional drawing which shows the principal part of the resin molding apparatus of another embodiment

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show an embodiment of a resin molding apparatus of the present invention. The resin molding apparatus M includes a front resin layer 2A sandwiched between front and back decoration layers 1 (1A, 1B) (see FIG. 6), and a multilayer molded product 2 (see FIG. 4) provided with a back side resin layer 2B integrated on the back side of the front side resin layer 2A.

  As a mold for forming the multilayer molded product 2, a fixed mold T having a resin discharge gate G and a movable mold U configured to be clamped with respect to the fixed mold T are provided.

The fixed mold T is formed between the movable mold U and the first fixed mold T1 that molds the back side portion of the front resin layer 2A, and the movable mold U between the back surface side of the front resin layer 2A. And a second fixed mold T2 for integrally molding the back side resin layer 2B.
As shown in FIG. 1, the two fixed molds T1 and T2 are installed in a state where both are adjacent to the fixed mold base T0.
The first fixed mold T1 is provided with a first gate G1 for feeding the first resin P1 for forming the front resin layer 2A. On the other hand, the second fixed mold T2 is provided with a second gate G2 for feeding the second resin P2 (see FIG. 4) for forming the back side resin layer 2B.
Furthermore, the second transfer sheet arrangement means 7 for arranging the transfer sheet 6 for forming the decorative layer 1B on the back surface side of the front side resin layer 2A along the molding surface of the first fixed mold T1, It is provided corresponding to the first fixed mold T1.

The movable mold U is installed in a state in which a pair of the same shape so as to correspond to the first fixed mold T1 and the second fixed mold T2 is adjacent to the movable substrate U0. Yes.
The movable base U0 is supported by the rotating shaft 4, and is configured to be able to reverse the corresponding position with respect to both the fixed molds T1 and T2 by rotating 180 degrees around the axis J.
Accordingly, the movable base U0 is rotated 180 degrees around the axis J while one movable mold U corresponds to the first fixed mold T1 and the other movable mold U corresponds to the second fixed mold T2. As a result, one moving type is changed to the second fixed type T2, and the other moving type is changed to a state facing the first fixed type T1. The rotating shaft 4 constitutes a moving mechanism H.
Further, the transfer sheet 8 for forming the transfer layer 8 for forming the decorative layer 1A on the surface side of the front resin layer 2A is arranged along the molding surface of the movable mold U. U is provided corresponding to U.

Further, the movable die U is provided with a holding portion 5 that can be held in a state where the front side resin layer 2A is molded (see FIG. 2).
Therefore, the front side resin layer 2A molded with the first fixed mold T1 can be held as it is by the holding part 5, and the front side resin layer 2A is held on the movable mold U side when the mold is opened. Thus, it can be detached from the first fixed mold T1 (see FIG. 3). Therefore, since the decorative layer integrated on both surfaces of the front side resin layer 2A is protected by the movable mold U through the molding process, it is difficult to be damaged.

As an example of the holding part 5, as shown in FIG. 5, there is a slide mold Ua that is movable along a slide direction Y perpendicular to the mold clamping direction X of the movable mold U.
In this example, portions that can be sandwiched between the movable mold U and the slide mold Ua are formed in advance at several locations on the outer edge portion to be cut off of the front side resin layer 2A. By sandwiching with U, the front-side resin layer 2A can be held in the movable mold U.
Further, by opening the slide mold Ua along the slide direction Y, the holding of the front resin layer 2A can be released.

Incidentally, as shown in FIG. 6, the multilayer molded product 2 described in the present embodiment is provided in a tray-shaped front resin layer 2A with the product surface down, and along the peripheral edge on the back surface side of the front resin layer 2A. The back side resin layer 2B is formed.
2 A of said front side resin layers are comprised by transparent 1st resin P1, and the decoration layer 1 is provided in the front and back. Therefore, from the surface side of the product, not only the front surface side decorative layer 1A but also the back side decorative layer 1B can be seen through.
Moreover, the 1st resin P1 which comprises 2A of front side resin layers uses the glass transition point of 120-100 degreeC, and the 2nd resin P2 which comprises the back side resin layer 2B has a glass transition point of 100- 100. The one at 80 ° C is used.
In particular, with respect to the second resin P2 discharged on the back side of the front side resin layer 2A in contact with the decorative layer 1B on the back side, the glass transition point is low enough not to cause ink flow in the decorative layer 1B. Is set. On the other hand, the first resin P1 has a higher glass transition point than the second resin P2 because no ink flow occurs. As a result, the heat resistance of the product surface can be improved.

Next, a specific product forming method will be described.
[1] As shown in FIG. 1, the transfer sheet 6 is arranged along the molding surface of the first fixed mold T1 by the second transfer sheet arranging means 7, and the moving type U is arranged by the first transfer sheet arranging means 9. The transfer sheet 8 is arranged along the molding surface.
[2] Move the movable mold U close to the first fixed mold T1, perform mold clamping, and discharge the first resin P1 from the first gate G1 (see FIG. 2). At this time, the holding unit 5 is kept closed.
[3] When the molding of the front side resin layer 2A is completed, the movable die U is opened while the front side resin layer 2A is held by the holding portion 5, and the movable die U is rotationally driven by the moving mechanism H, whereby the second fixed die Move to a position corresponding to T2 (see FIG. 3).
[4] The movable mold U is clamped with respect to the second fixed mold T2, and the second resin P2 is discharged from the second gate G2 (see FIG. 4). When the integration of the front resin layer 2A and the back resin layer 2B is completed, the holding part 5 is opened and the molded product is removed from both molds.
Each of the above steps can be performed in parallel while being shifted by the pair of movable dies U.

  According to the resin molding technique of the present embodiment, since a resin having a high glass transition point is used for the front-side resin layer 2A, a multilayer molded product 2 having a high heat resistance of the product surface layer can be formed. In addition, since a resin having a low glass transition point is used for the back side resin layer 2B, it is possible to make the ink flow of the intervening decorative layer 1B less likely to occur, and it is possible to form the multilayer molded product 2 having high aesthetics.

[Another embodiment]
Other embodiments will be described below.

<1> The multilayer molded product 2 is not limited to the shape and configuration described in the previous embodiment, and can be appropriately changed. For example, not only a two-color molded product but also a multi-color molded product of three or more colors may be used.
<2> The decorative layer is not limited to the one transferred by the transfer sheet 6 described in the previous embodiment, and may be formed using, for example, an insert sheet.
<3> Regarding the molding of the back side resin layer 2B, for example, as shown in FIG. 7, after the molten resin is discharged into the corresponding cavity space to the second fixed mold T2, the compression molding is performed by further pressing the molten resin. Means Q may be provided, and a method may be adopted in which a distance from the gate to the decorative layer is ensured at the time of discharging the resin so that the ink flow of the decorative layer is less likely to occur.
<4> The arrangement of the fixed mold, the movable movement mechanism, and the like are not limited to those described in the previous embodiment. For example, a pair of fixed molds are arranged opposite to each other with the movable mold interposed therebetween, and the movable mold Can be configured to be rotatable around an axis that is orthogonal to the opposing direction of the fixed mold, and the movable mold can be configured to be mold-clampable with respect to both fixed molds.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Decorating layer 2 Multilayer molded product 2A Front side resin layer 2B Back side resin layer 5 Holding part H Moving mechanism P1 1st resin P2 2nd resin T1 1st fixed type T2 2nd fixed type U Moving type Ua Slide type

Claims (8)

A front side resin layer sandwiched between front and back decoration layers,
A resin molding apparatus for forming a multilayer molded article comprising a back side resin layer integrated on the back side of the front side resin layer,
A first fixed mold for molding the back side portion of the front resin layer;
A movable mold that integrally molds the front and back decorative layers and the front resin layer with the first fixed mold;
A holding part that can be held in the movable mold while the front resin layer is molded;
A second fixed mold that integrally molds the back-side resin layer on the back side of the front-side resin layer held in the movable mold by the holding portion;
A resin molding apparatus provided with a moving mechanism capable of moving the movable mold from a position corresponding to the first fixed mold to a position corresponding to the second fixed mold.   2. The resin molding apparatus according to claim 1, wherein the second resin forming the back resin layer has a glass transition point set lower than that of the first resin forming the front resin layer.   The resin molding apparatus according to claim 1, wherein the holding portion is configured by a slide mold that is movable along a direction perpendicular to the movable mold clamping direction.   The resin molding apparatus according to any one of claims 1 to 3, wherein the second fixed mold is provided with a compression molding unit that pressurizes the molten resin after discharging the molten resin into a corresponding cavity space. . A resin molding method for forming a multilayer molded article comprising a front side resin layer sandwiched between front and back decorative layers and a back side resin layer integrated on the back side of the front side resin layer,
The mold is clamped in a state where the decorative layers are positioned separately along the molding surfaces of the first fixed mold and the movable mold, and the first resin is discharged between the decorative layers to Molding the integrated front resin layer,
The front-side resin layer is separated from the first fixed mold while being held by the movable mold, and the movable mold is moved and clamped so that the second fixed mold is located on the back side of the front-side resin layer, and the front-side resin A resin molding method in which a second resin having a glass transition point lower than that of the first resin is discharged to the back side of the layer to mold the back resin layer integrally with the front resin layer.   The resin molding according to claim 5, wherein after the second resin is discharged into a cavity space between the second fixed mold and the movable mold, the molten resin is pressurized from the second fixed mold side to perform compression molding. Method. A multilayer molded article comprising a front side resin layer sandwiched between front and back decorative layers, and a back side resin layer integrated on the back side of the front side resin layer,
The first resin constituting the surface resin layer is a multilayer molded article having a glass transition point higher than that of the second resin constituting the back resin layer. A multilayer molded article comprising a front side resin layer sandwiched between front and back decorative layers, and a back side resin layer integrated on the back side of the front side resin layer,
The multilayer molded product which comprises the said front side resin layer and the said back side resin layer with transparent resin, and provided the decorating layer in the back surface of the said back side resin layer.

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