JPH0449110Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a storage case for a plastic tape cartridge, and is particularly aimed at preventing thermal deformation under high temperatures.

[Conventional technology]

For example, as a prior art plastic storage case for video tape cartridges, a book case type as shown in Fig. 3 was developed in the 1980s.
It is publicly known from Publication No. 38277 and the like. This is generally done by printing on the outer surface of a transparent or translucent polypropylene sheet, leaving a transparent window W for viewing the contents for purposes such as packaging design, and then die-cutting it into a predetermined shape as shown in Figure 4. It is assembled by folding a flat semi-finished product A, which has been molded and subjected to fold line processing, into a book case shape.

That is, as shown in FIG. 4, the semi-finished product A has left and right side plates 2 and 3 having transparent windows W on the left and right sides of a central back plate 1, which are connected to each other via a fold line L, and the left side plate 2 and the right side Flaps 6 and 7 are connected to the top and bottom of the face plate 3 via fold lines L, respectively. In this way, the left side plate 2 and the right side plate 3 are bent so as to face each other in parallel, and the upper flap 6,
7 and the lower flaps 6 and 7 are overlapped inside and out, respectively, and integrally joined with a hot melt adhesive 8, thereby assembling the book case into a book case whose front side can be opened as an inlet/outlet 9 for a tape cartridge T. In Figure 5,
10 indicates a printing ink layer applied to the outer surface side.

[Problem that the invention attempts to solve]

However, as a result of a heat deformation test in which the storage case constructed in this way was left for approximately 100 hours at a high temperature of 50 to 60 degrees Celsius, the free end side of the outer flap 7 that was not bonded was as shown in Fig. 6. It has been found that it warps outward as shown by the broken line F and easily peels off from the inner flap 6. Although the cause of this is not certain, it is thought that the warpage is caused by thermal stress caused by the hot melt of the outer flap 7 and thermal contraction of the printing ink layer 10. That is, in the hot-melt bonding process, the free end side of the non-bonded part of the outer flap 7 is first heated (170 to 180 degrees Celsius) by the adhesive 8 as shown in FIG. 7a.
As shown in the figure, when the flap 7 is deformed into an outwardly convex shape and then flattened by applying pressure P in the process of overlapping the flaps 6 and 7, its outer surface An internal stress is generated that compresses the side in the direction of arrow X and remains. Therefore, especially when left under high temperature, the internal stress of the flap 7 is released by the heat, causing it to warp outward as shown by the symbol F in FIG. It is thought that the thermal contraction of the plastic resin, which is a solid binder, promotes the warpage.

The purpose of this invention is to improve adhesion by eliminating such outward warping of the flap.

[Means for solving problems]

In order to achieve the above object, the present invention is based on a plastic tape cartridge storage case in which the flaps 6 and 7 are overlapped on the inside and outside and the overlapping surfaces are bonded together by hot melt bonding.
The shape of the storage case is not limited to the bookcase type,
Also includes other shapes.

Then, a printing ink layer 10 containing a plastic resin is formed on both the front and back surfaces of the outer flap 7 or on the hot melt adhesive surface side of the back surface thereof. Since the flaps 6 and 7 are constructed to be integrally connected to the storage case, polypropylene and vinyl chloride resin are preferably used as materials because of their excellent transparency. In addition, polyethylene may be used. Among these, polypropylene is particularly preferred since it has good hinge characteristics when folded along the fold line L. As the plastic resin, for example, urethane resin is used.

[Effect of idea]

According to the present invention as described above, since the hot-melted outer flap 7 has the printing ink layer 10 containing a plastic resin on the hot-melt adhesive side, the flap 7 is deformed due to the release of residual stress generated during hot-melting. However, this occurs in the opposite direction to the broken line F in FIG. 6, that is, inward, making it possible to eliminate the peeling phenomenon seen in the conventional example.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

Since the overall structure of the storage case is almost the same as that cited as the conventional example, only the differences will be explained.

FIG. 1 shows a first embodiment of the present invention, in which an ink layer 10 of the same type as the printing ink layer 10 on the outer surface side is formed on the back side of the outer flap 7 made of a polypropylene sheet, and then hot melt It is joined and integrated with the inner flap 6 via an adhesive 8 in a polymeric manner. As the solid binder of the printing ink layer 10, a urethane resin was used. Further, as the hot melt adhesive 8, a modified olefin type adhesive was used.

FIG. 2 shows a second embodiment of the present invention, in which the same printing ink layer 10 as in the first embodiment is formed only on the back side of the outer flap 7, and the rest of the structure is the same as in the first embodiment. The same procedure as in Example 1 was carried out.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts showing a first embodiment of a storage case according to the present invention, and FIG. 2 is a sectional view of essential parts showing a second embodiment of the present invention. 3 is a perspective view showing a conventional storage case and a tape cartridge stored therein, FIG. 4 is a developed view of the storage case, and FIG. 5 is a sectional view taken along line V-V in FIG. FIG. 6 is a sectional view of the main part, and FIGS. 7a and 7b are sectional views showing the process of occurrence of defective warping deformation of the flap. 6...Inner flap, 7...Outer flap, 8...Hot melt adhesive, 10...Printing ink layer.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a storage case for a tape cartridge made of plastic, which is formed by overlapping flaps 6 and 7 on the inside and outside and integrating the overlapped surfaces with hot melt adhesive 8, A storage case for a tape cartridge, characterized in that a printing ink layer 10 is formed on at least the hot melt adhesive side of the flap 7. (2) The tape cartridge storage case according to claim 1, wherein the flaps 6 and 7 are made of polypropylene. (3) The tape cartridge storage case according to claim 1, wherein the flaps 6 and 7 are made of vinyl chloride resin. (4) The tape cartridge storage case according to claim 1, wherein the flaps 6 and 7 are made of polyethylene. (5) The storage case for a tape cartridge according to claim 1, wherein the printing ink layer 10 contains a plastic resin. (6) The tape cartridge storage case according to claim 5, wherein the plastic resin is a urethane resin.