JP2002234955A - Resin film for in-mold molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin film for in-mold molding having the excellent moldability and excellent printing characteristics. SOLUTION: The resin film for in-mold molding comprises a composition of a polycarbonate resin and a polyethylene terephthalate resin, wherein the composition ratio of the polycarbonate resin and the polyethylene terephthalate resin is in the range of 90-50/10-50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin film comprising a composition of a polycarbonate resin and a polyethylene terephthalate resin, and more particularly to a resin film used for in-mold molding.

[0002]

2. Description of the Related Art Touch keys and the like of mobile phones mainly print numbers on an extruded plastic film.
The film is manufactured by setting the film in a mold of an injection molding machine and then injecting a resin.

Here, as a plastic film,
Polycarbonate resins and polyethylene terephthalate resins are generally used.

[0004]

However, when the polycarbonate film is used, there is a problem that a portion which does not follow the mold is generated at the corner of the mold or the sheet thickness is reduced. In order to solve this problem, it is conceivable to devise a method of heating the film in advance. However, another problem occurs in that the time required for production is increased and the productivity is reduced.

[0005] Further, when a polyethylene terephthalate film is used, there is no problem that occurs in the above-mentioned polycarbonate film. However, when a numeral or the like is printed on this film, the film is damaged by the printing ink, the film is deteriorated, and the film becomes cloudy or cracked. Or the phenomenon that the printing ink does not sufficiently adhere to the film occurs.

An object of the present invention is to provide a resin film for in-mold molding which has solved the above-mentioned problems of moldability or printability.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the above problem has been solved by setting the composition ratio of these resins to a specific range in a resin film composed of a polycarbonate resin and a polyethylene terephthalate resin. Is found to be solved. That is, the present invention relates to a resin film for in-mold molding comprising a composition of a polycarbonate resin and a polyethylene terephthalate resin, wherein the composition ratio of the polycarbonate resin and the polyethylene terephthalate resin is 90 to 50/10.
~ 50.

The polycarbonate resin of the present invention is a well-known polycarbonate resin produced by, for example, a phosgene method based on a reaction between dihydric phenol and phosgene or a transesterification method based on a reaction between divalent phenol and diester carbonate.
As the dihydric phenol, bisphenols, particularly 2,2
It is preferred to use 2-bis (4-hydroxyphenyl) propane (bisphenol A). As the carbonic acid diester, it is preferable to use diphenylphenyl carbonate.

Here, it is desirable to use a polycarbonate resin having a molecular weight in the range of 25,000 to 30,000. This is because even if it is less than 20,000 or exceeds 30,000, a good film cannot be obtained in extrusion molding.

As the polycarbonate resin used in the present invention, two or more resins having different molecular weights may be used. Further, a branched polycarbonate resin may be used.

As the polyethylene terephthalate resin of the present invention, for example, a well-known one produced from dimethyl terephthalate and ethylene glycol is used.

The composition ratio of the polycarbonate resin and the polyethylene terephthalate resin used in the present invention is 90
５０50 / 10１０〜50. If the composition ratio of the polycarbonate resin is smaller than this, a printing problem, that is, a problem such as deterioration of the film due to the printing ink or poor adhesion of the printing ink occurs. Conversely, if the composition ratio of the polycarbonate resin is larger than this, there is a problem in molding, that is, a problem that the film does not sufficiently follow the mold or the sheet thickness is reduced.

[0013]

Next, specific embodiments of the present invention will be described.

First, the following raw materials were used in Examples and Comparative Examples. (Polycarbonate resin) "Iupilon" manufactured by Mitsubishi Engineering-Plastics Corporation
E2000F ”(molecular weight: 27000) (polyethylene terephthalate resin)“ 3212 ”manufactured by Sehan Corporation

<Examples 1 and 2 and Comparative Examples 1 to 3> Each resin was mixed at a composition ratio shown in Table 1 using a tumbler mixer, and the mixture was mixed with a 50 mm diameter single screw extruder (L / D = 30).
Was used to obtain a film having a thickness of 500 μm. The printability and moldability of the obtained film were evaluated as follows, and the evaluation results are shown in Table 1.

<Printability> The obtained film was subjected to screen printing using a printing ink (SG240 manufactured by Seiko Advance Co., Ltd.). Thereafter, the film was allowed to stand under the following conditions A to C, and the film was observed for cloudiness, cracks, and the like. Further, the film was subjected to a cross-cut cross hatch tape peeling test (based on JIS K5400), and peeling of the printing ink was observed. 1 in any of the conditions A to C
も の indicates no peeling of the film and no defect such as cloudiness or cracks of the film, and x indicates no peeling. A. Room temperature (1 day, 3 days and 1 week) 60 ° C (1 week) 60 ° C x 2 hours ~ -20 ° C x 2 hours as 1 cycle, 10 cycles

<Moldability> Using the above film and a mold for a touch key of a mobile phone, a touch key of a mobile phone was manufactured by continuous in-mold molding. The appearance of the obtained touch keys was visually observed for defects in the appearance.な い indicates no defect, and X indicates no defect.

Comparative Example 4 A film having a thickness of 500 μm was obtained by the same extrusion molding as in the above example. Next, the printability and moldability of the obtained film were evaluated as follows, and the evaluation results are shown in Table 1.

<Printability> The obtained film was printed using a printing ink (SSNSA manufactured by Toyo Ink Mfg. Co., Ltd.) in the same manner as in the above-mentioned example, and evaluated.

<Moldability> Molding is performed in the same manner as in the above example, and the same evaluation is performed. Table 1 shows the results.

[0021]

[Table 1]

[0022]

As described above, the resin film for in-mold molding according to the present invention is a resin film comprising a polycarbonate resin and a polyethylene terephthalate resin, and by setting the composition ratio of these resins to a specific range,
Both in-mold molding characteristics and printing characteristics can be provided.

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Claims (1)

[Claims] 1. An in-mold resin film comprising a composition of a polycarbonate resin and a polyethylene terephthalate resin, wherein the composition ratio of the polycarbonate resin and the polyethylene terephthalate resin is 90 to 50/10 to 10.
50. A resin film for in-mold molding, wherein the thickness is in the range of 50.