JPH0417129B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for transferring a desired pattern to the inner surface of a convex resin molded product, and more specifically, the present invention relates to a method for transferring a desired pattern to the inner surface of a convex resin molded product, and more specifically, when the resin molded product has a convex curved shape and The present invention also relates to a method by which a pattern can be accurately transferred to the inner surface of the object in a very simple manner.

(Prior Art) Japanese Patent Publication No. 51-33456 discloses a method for painting resin molded products as a method for transferring an arbitrary pattern onto the curved surface of a resin molded product. This involves heat-molding a transfer sheet with an arbitrary pattern formed on a base sheet that can be thermoformed, with the pattern surface as the inner surface, to form a transfer molded body that matches the inner surface of a molding mold, and then The transfer molded body is mounted on the inner surface of a molding receiving mold, and then a molding resin is supplied to the inner surface of the transfer molded body and molded,
Next, the above-mentioned mold receiving die is removed, and the base sheet of the above-mentioned transfer sheet is then peeled off (hereinafter referred to as Conventional Example 1).

Furthermore, while the conventional example described above involves transferring a pattern to the outer surface of a resin molded product, a method of transferring a pattern to the inner surface of a resin molded product is disclosed in Japanese Patent Application Laid-open No. 118835/1983, particularly in FIG. 9A. (hereinafter referred to as conventional example 2).

Since the method of Conventional Example 1 transfers a pattern onto the outer surface of a transparent resin molded product, the transferred pattern appears planar. At this time, a configuration has been disclosed in which the surface of the transferred pattern is coated with a transparent resin to prevent scratches, etc. However, since the coating layer is extremely thin, the transferred pattern cannot be seen three-dimensionally. On the other hand, since the method of Conventional Example 2 transfers the pattern to the inner surface of the transparent resin molded product,
The transferred pattern can be seen from the outside and exhibits an optical three-dimensional effect, resulting in an excellent design, and there is no risk of scratches.

(Problems to be Solved by the Invention) In both Conventional Examples 1 and 2, a transfer molded body having the same shape as the injection mold molded to mold the transfer sheet is pre-molded, and the molded transfer The molded body is accurately mounted in an injection mold, and molten resin is injected onto the pattern side of the molded body to obtain a resin molded product. The work is complicated as it has to be attached, and since there is no means to prevent the transfer molding from moving during injection molding, the position of the pattern appearing on the resin molded product may vary due to the movement of the transfer molding. There is a problem with sticking.

An object of the present invention is to make it possible to easily attach a transfer molded body to a mold in a product in which a pattern is transferred to the inner surface of a resin molded product as in Conventional Example 2, and also to enable the transfer molded body to be easily attached to a mold. The object of the present invention is to provide a uniform pattern transfer method that prevents the movement of the transfer molded body during injection molding by fixing the resin molded product to the position of the resin molded product, thereby preventing variation in the position of the pattern exposed on the resin molded product.

Another object of the present invention is to provide a pattern transfer method that allows a pattern to be transferred to the open end face of a convex resin molded product.

(Means for Solving the Problems) The present invention employs the following means to achieve the above object. That is, a transfer sheet with an arbitrary pattern formed on a heat-moldable release sheet is heat-molded to obtain a transfer molded body, and the transfer molded body is mounted in a resin molding mold to form a transfer molded body. After molding by supplying molten resin to the pattern side of the mold, the convex resin molded product is taken out from the mold, and the release sheet is removed from the transfer molded body integrally formed on the surface of the resin molded product. In the method of transferring a pattern to the surface of a resin molded product, a transfer sheet 4 is heated and formed into a convex shape with a flange portion 10 with the pattern surface as the outer surface to obtain a transfer molded body 9, and then the transfer molded body is 9 is loosely installed in the cavity 13 of an injection mold 12 for resin molding, and the flange portion 10 of the transfer molded body 9 is inserted into the mold 12.
The transfer molded body 9 is clamped and fixed between the female mold 15 and the male mold 16, and then the transfer molded body 9 is molded by the injection pressure of transparent or translucent molten resin 17 supplied to the outer surface of the transfer molded body 9.
The shell wall is molded in contact with the outer surface of the male mold 16, and after the molding is completed, the resin molded product is taken out from the mold 12 and the release sheet 5 is peeled off to form a desired pattern transferred onto the inner surface of the resin molded product. It is characterized by

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

6 and 7 show a convex resin molded product 1 with a pattern 2 transferred thereon by the method of the present invention.
This molded product 1 is used, for example, as a cap for a cosmetic container, a container lid, or the like.

Next, a pattern 2 is applied to the resin molded product 1 by the method of the present invention.
We will explain in detail the case of transcribing.

First, the transfer sheet applied to the present invention is one in which an arbitrary pattern 2 (however, letters or the like may be formed) is formed on a heat-formable release sheet. can be mentioned. The transfer sheet 4 shown in FIG. 2 has a pattern 2 formed on a release sheet 5, and an adhesive layer 7 formed on the entire surface of the release sheet 5 including the pattern 2. In the transfer sheet 4 shown in FIG. 3, a resin layer 8 is formed on the entire surface of a release sheet 5 to prevent the pattern from being worn out after transfer, a pattern 2 is formed on the resin layer 8, and a pattern 2 is further formed on the resin layer 8. An adhesive layer 7 is formed on the entire surface of a resin layer 8 containing . In addition, Figures 2 and 3
Although not shown in the figures, a release agent layer is formed directly above the release sheet 5.

The release sheet 5 is made of polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, or the like.

Further, the pattern 2 is formed by printing, drawing, painting, etc. using ordinary plastic printing ink and paint. The pattern of the transfer sheet is determined by taking into consideration deformation when the transfer sheet is heated and bulged by molten resin, which will be described later. However, it is preferable to use a pattern in which the outline may flow somewhat, for example, a wood grain or stone pattern, since there is no need to consider the deformation of the pattern so much.

Examples of the material for the adhesive layer 7 include acrylic resin, vinyl resin, polyamide resin, phenol resin, etc., and are determined in consideration of weldability with the resin forming the resin molded product.

Furthermore, examples of the material of the resin layer 8 include alkyd resin, phenolic resin, vinyl resin, epoxy resin, and acrylic resin.

The above-mentioned transfer sheet 4 is heated and formed into a transfer molded body 9 having a flange portion 10, as shown in FIG. 4, with the patterned surface as the outer surface. Examples of the heating molding method include vacuum molding, blow molding, press molding, etc. using a heating means. The substantially hemispherical main body 11 of the transfer molded body 9 only needs to have a shape that is substantially the same as the outer surface shape of the male die 16 described later, and does not require a tight fit. It is sufficient if it can be freely installed in the cavity 13 in the injection mold 12 for resin molding. Next, as shown in FIG.
1 is lightly placed on the male mold 16 and the flange portion 10 is placed, and then the female mold 15 and the male mold 16 form a cavity 13, and the flange portion 10 of the transfer molded body 9 is clamped and fixed. Although the injection mold 12 is composed of two members, a female mold 15 and a male mold 16, it goes without saying that the number, shape, etc. of the mold members are not limited.

Next, as shown in FIG. 5, the injection mold 12
A transparent or translucent molten resin 17 is injected from the female mold 15 onto the outer surfaces of the main body 11 and the inner circumferential portion 10a of the flange portion 10 of the transfer molded body 9 mounted in the cavity 13 of the transfer molding body 9. At this time, the molten resin 17 is appropriately selected from synthetic resins such as vinyl resins, polyethylene, polypropylene, styrene resins, polyamides, and phenolic resins, depending on the required characteristics of the molded product.

As the molten resin 17 is injected onto the outer surface of the transfer molded body 9, the injection pressure of the molten resin 17 causes the shell wall of the transfer molded body 9 to form the male mold 16 as shown in FIG.
abuts the outer surface of the In this way, the transfer molded body 9 is integrally formed on the inner surface of the resin molded product 1 molded by the mold 12, and a part of the resin molding and the transfer process are simultaneously achieved.

After completing the molding of the resin molded product 1, the molding injection mold 1
The female mold 15 and male mold 16 of 2 are separated and the molded product 1 is taken out, and the release sheet 5 arranged on the outermost surface of the transfer molded body 9 is peeled off and a desired pattern 2 is formed on the inner surface.
A transparent or semi-transparent resin molded product 1 having been transferred is obtained.

In the above embodiment, for example, the pattern 2 in the transfer molded body 9 shown in FIG. For example, if you use something with 2a such as a colored ring pattern,
As shown in FIG. 7, the open end surface 1a of the resin molded product 1
The pattern 2a can be transferred up to the point where the resin molded product 1 is observed from the outside, and the three-dimensional effect can be further enhanced and the design effect can be enhanced.

This cannot be achieved even if a transfer molded body having a flange portion is used when transferring a pattern to the outer surface of the resin molded article of Conventional Example 1.

(Effects of the Invention) The present invention allows the transfer molded body 9 provided with the flange portion 10 to be loosely installed in the cavity 13 of the injection mold 12, and the flange portion 10 of the transfer molded body 9 to be inserted into the female mold 15 of the injection mold 12. and a male mold 16, and then the shell wall of the molded body 9 is molded in contact with the male mold by the injection pressure of the transparent or translucent molten resin supplied to the outer surface of the molded body 9. The transfer molded body 9 can be fixed in position by simply placing it lightly on the male mold 16, so it is easy to install and has excellent workability, and since the transfer molded body 9 is prevented from moving during injection molding, the resin There is no variation in the position of the pattern appearing on the molded product. Therefore, the mold for forming the transfer molded body 9 does not require high precision and can be inexpensive.

Furthermore, the present invention can provide a resin molded product that enhances the three-dimensional effect of the pattern or enhances the sense of design by making it possible to transfer a pattern to the open end surface of the resin molded product if necessary.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an injection mold for resin molding with a transfer molded body attached, Figures 2 and 3 are cross-sectional views showing the structure of the transfer sheet, and Figure 4 is a partial cutaway of the transfer molded body. A front view, FIG. 5 is a cross-sectional view of the resin molding mold upon completion of injection injection of molten resin, FIG. 6 is a partially cutaway front view showing an example of a resin molded product, and FIG. 7 is a bottom view of the same. . 1... Resin molded product, 2... Pattern, 4... Transfer sheet, 5... Release sheet, 9... Transfer molded body, 1
2...Mold for resin molding, 15...Female mold, 16...
Male type, 17... Molten resin.

Claims (1)

[Claims] 1. A transfer sheet with an arbitrary pattern formed on a heat-formable release sheet is heat-molded to obtain a transfer-molded body, and the transfer-molded body is placed in a resin molding mold. After supplying and molding the molten resin to the pattern side of the transfer molded product, the convex resin molded product is taken out from the mold and peeled off from the transfer molded product integrally formed on the surface of the resin molded product. In the method of removing the sheet and transferring a pattern to the surface of a resin molded product, the transfer sheet 4 is heat-formed into a convex shape with a flange portion 10 with the pattern surface as the outer surface to obtain a transfer molded body 9, and then the transfer molded body 9 is obtained. The transfer molded body 9 is loosely placed in the cavity 13 of an injection mold 12 for resin molding, and the flange portion 10 of the transfer molded body 9 is inserted into the mold 12.
The transfer molded body 9 is clamped and fixed between the female mold 15 and the male mold 16, and then the transfer molded body 9 is molded by the injection pressure of transparent or translucent molten resin 17 supplied to the outer surface of the transfer molded body 9.
The shell wall is molded in contact with the outer surface of the male mold 16, and after the molding is completed, the resin molded product is taken out from the mold 12 and the release sheet 5 is peeled off to form a desired pattern transferred onto the inner surface of the resin molded product. A method for transferring patterns on resin molded products.