JPH0661770B2 - Method for integrally molding surface-printed thermoplastic resin molding - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for integrally molding a surface-printed thermoplastic resin molded article, the purpose of which is to provide a surface without a printing step after molding the thermoplastic resin. A surface-printed thermoplastic resin molded product that can be integrally molded with a printed thermoplastic resin (so-called decorative molded product), is particularly easy to manufacture, and can obtain a sturdy product, and has good corner fitting. It is to provide an integral molding method of.

(Background of the Invention) Conventionally, plywood is often used for decorative plates such as table plates and kotatsu plates.

In this plywood, for example, a front plate is attached to both surfaces of a core material with an adhesive, and the surface of the front plate is further overlaid depending on the application.

In addition, plastic housings for air conditioners and refrigerators were injection molded with synthetic resin, and then a decorative housing or transfer paper whose surface was made up with heat transfer, painting, etc. was continuously inserted into the injection mold. There is a makeup housing.

However, since the plywood used for the above-mentioned conventional decorative board has the core material, the surface board, and the decorative base material bonded to each other with an adhesive, this bonding work is necessary. There was a problem that the work was difficult.

Further, since the decorative base material and the surface material are attached to each other by the adhesive material, the decorative base material may be peeled from the material or may be misaligned.

On the other hand, in order to apply makeup after molding the housing of an air conditioner or a refrigerator with a synthetic resin, the makeup is cooled and then the makeup is applied by a painting method.

These were methods such as hot stamping, painting, and thermal transfer.

However, since the housing is usually three-dimensionally molded and has few flat parts and curved edges, these methods are not suitable for front surface printing with curved surfaces or corners, and are not applied to large-sized members. It was

In particular, when a pattern paper or the like is laminated, wrinkles and sagging occur on the curved surface portion and the corner portion, and the desired makeup cannot be obtained.

Furthermore, the painting by rolling could not be applied to the corners.

(Prior Art) Further, as a technique for manufacturing a decorative plate, there is a technique disclosed in JP-A-57-20315.

The disclosed technique is capable of intimately adhering the acrylic resin on the printing surface to a part or all of the inner surface of the mold when injecting a polymerizable liquid of the acrylic resin into the mold to polymerize and cure the acrylic resin. A transfer printing sheet having a print protection layer of the material is attached with the printing surface inside, and a polymerizable liquid of resin is injected.

This transfer printing sheet is formed by applying a release coat to a base film, printing the coated film, and then coating a printing surface protective layer thereon.

Then, it is sealed and put under an appropriate temperature condition, for example, 80
Soak in hot water bath at ~ 100 ° C for 1-5 hours, then 100 ~
After being placed in an oven at 150 ° C. for 2 to 5 hours for polymerization and curing, the base film was peeled off.

(Problems to be Solved by the Invention) However, according to the disclosed technique, a transfer printing sheet is attached to the inner surface, and a mold in which a polymerizable liquid of a resin is injected is hermetically sealed, and the bath is heated under a suitable temperature condition, for example, at a temperature of 80 to 100 ° C. Since it is immersed in the solution for 1 to 5 hours and then placed in an oven at 100 to 150 ° C. for 2 to 5 hours to polymerize and cure, the productivity of the molded product is poor.

Moreover, it is not preferable for housings of air conditioners and refrigerators because it must be formed after printing on the release coat in advance.

In other words, the housing is usually molded in three dimensions, and the edges are curved with few flat portions. Therefore, in order to manufacture a molded product formed in such a three-dimensional manner, the inner surface was formed in three dimensions. A transfer printing sheet must be attached to the formwork.

Therefore, wrinkles and slack are formed on the curved surface portion and the corner portion, which is not preferable.

Therefore, in view of the above conventional circumstances, the present inventors can integrally mold a thermoplastic resin without applying an adhesive work or a printing process, and at the same time, can make up the product, which is good in productivity and has a good corner fit. The research on the integral molding method of the surface-printed thermoplastic resin molding was continued.

(Means for Solving the Problems) That is, according to the present invention, a printing sheet comprising two layers of a printing layer and a peeling layer is disposed on the lower mold of a mold device having an upper mold and a lower mold, and then the upper mold is provided. After supporting the sheet by clamping the lower mold and the lower mold, the upper mold and the lower mold are further clamped, and a required molten resin path is provided between the sheet and one of the upper mold and the lower mold. A molten resin composed of a thermoplastic resin is supplied from the above to integrally mold the sheet and the molten resin,
After that, it is a method of integrally molding a surface-printed thermoplastic resin molding characterized by removing the release material of the printed circuit board material. There is an effect that it can be used as an integrated molding method of the plastic resin molded body.

(Embodiment) An integral molding method according to an embodiment of the present invention and an integral molding obtained by the present invention will be described below with reference to FIGS. 1 to 6.

1 to 3, (1) is a mold device, and the mold device (1) includes a lower mold (2) and a cavity (3a) which are male molds.
And an upper mold (3) composed of a female mold.

The upper die (3) is supported so as to be lifted and lowered by a well-known lifting device (not shown).

(4) is a fixed frame provided on the outer surface side of the lower die (2) so that the sliding surface (4a) slides on the outer surface (2a) of the lower die (2).

A telescopic device (5) is provided below the fixed frame (4), and the fixed frame (4) is supported by the telescopic device (5) so as to be vertically movable.

The expansion / contraction device (5) may be any of known hydraulic cylinders, pneumatic cylinders, pneumatic springs, urethane springs, steel springs, etc., depending on the stroke required.
In this embodiment, a spring mechanism that expands and contracts according to the mold clamping force of both molds (2) and (3) can be preferably used.

In order to operate the integrally molded product of the surface-printed thermoplastic resin molded body shown in FIGS. 4 and 5 with the mold device (1) having the above-described structure, the lower mold (2) is operated as shown in FIG. A sheet (6) composed of a printing layer (6b) and a peeling layer (6a) shown in FIG. 6 is supported on the fixed frame (4) so as to cover the sheet.

The printed sheet (6) is, for example, a release layer (6a) made of a synthetic resin having a release property. A print layer printed on the release layer (6a).
It consists of (6b).

With the print sheet (6) supported on the fixed frame (4), the second
As shown in the figure, when the upper mold (3) is moved downward and the mold is clamped, the printed sheet (6) will have a cavity (3a) in the upper mold (3).
Transforms within.

At this time, between the upper surface of the lower mold (2) and the printing sheet (6), for example, a polypropylene resin, a polyethylene resin, an acrylic resin is provided from a required molten resin path (not shown) provided in the lower mold (2). A molten resin (7) of a thermoplastic resin made of resin, acrylic-butadiene-styrene resin or the like is supplied.

In particular, styrene resin such as styrene resin is preferable.

Next, as shown in FIG. 3, when the upper mold (3) is further moved downward to perform mold clamping, the molten resin (7) spreads over the entire lower surface of the sheet (6) and the printing sheet ( 6) is shaped in the same way as a molded body with curved surfaces and corners.

At this time, as shown in FIG. 4, the printed sheet (6) is separated from the outer surface of the molded body (7a) of the molten resin (7) by the release layer (6a).
And the print layer (6b) is printed on the surface of the molded body (7a) and integrally molded to produce an integrally molded product (8).

In the above embodiment, the lower mold (2) is a male mold and the upper mold is
Although the mold apparatus having the configuration of (3) as the female type has been described, the present invention is not limited to this, and the lower type may be a female type and the upper type may be a male type.

In this case, the fixed frame (4) is provided on the outer surface side of the female lower mold, or the substrate material (6) is directly supported by the upper edge surface of the female lower mold without providing the fixed frame. May be.

Further, in this embodiment, the case where the upper mold is moved downward to clamp the mold has been described, but the present invention is not limited to this, and the lower mold may be moved upward to clamp the mold.

On the other hand, the integrally molded product is not limited to that of the above-described embodiment, and any member such as a building material such as a panel or a housing of an electric product can be adopted.

(Effects of the Invention) As described in detail above, according to the present invention, a printing sheet having two layers of a printing layer and a peeling layer is disposed on the lower mold of a mold apparatus having an upper mold and a lower mold, and then the upper mold is provided. After supporting the sheet by clamping the lower mold and the lower mold, the upper mold and the lower mold are further clamped, and a required molten resin path is provided between the sheet and one of the upper mold and the lower mold. A molten resin composed of a thermoplastic resin is supplied from the above to integrally mold the sheet and the molten resin, and then the release layer of the printed circuit board material is removed. Since it is a molding method, it has the following effects.

That is, the surface-printed thermoplastic resin (so-called decorative molding) can be integrally molded without a printing step after molding the thermoplastic resin, and the productivity is good.

It is possible to obtain a strong and easy-to-manufacture product, and there is an effect that it becomes an integral molding method of a surface-printed thermoplastic resin molded product in which curved surfaces and corners are particularly well fitted.

[Brief description of drawings]

1 to 3 are front cross-sectional explanatory views showing a process of manufacturing an integrally molded product by a mold device used for manufacturing a surface-printed thermoplastic resin molded product according to the present invention. 1 is a front cross-sectional explanatory view before mold clamping, FIG. 2 is a front cross-sectional explanatory view in the middle of mold clamping, FIG. 3 is a front cross-sectional explanatory view at the end of mold clamping, FIG. 4 and FIG. FIG. 6 is a perspective view of an embodiment of the integrally molded product, and FIG. 6 is a perspective view of a print sheet. (1) …… Molding device, (2) …… Lower mold (3) …… Upper mold, (3a) …… Cavity (6) …… Printing sheet, (7) …… Melting resin

Claims (1)

[Claims] 1. A printing sheet comprising two layers, a printing layer and a peeling layer, is provided on the lower mold of a mold device having an upper mold and a lower mold,
Next, after supporting the sheet by clamping the upper mold and the lower mold, the upper mold and the lower mold are further clamped, and a required space is provided between the sheet and one of the upper mold and the lower mold. A surface-printed thermoplastic resin molding characterized in that a molten resin made of a thermoplastic resin is supplied from a molten resin path to integrally mold the sheet and the molten resin, and then the release layer of the printed board material is removed. Body integral molding method.