JPS6241028A - Printed receptacle made of thermoplastic resin - Google Patents

Abstract

PURPOSE:To achieve the preparation of a printed receptacle made of thermoplastic resin, by injection-molding a developing plate having ruled line parts and notched parts, by printing this developing plate in a printing method using a long stand, and by making a case after drying. CONSTITUTION:On a working stand named a long stand the required number (in an example, ten) of mold punching frames 2 are bonded. At each frames 2 the required number (in an example, six) of punching portions 4 which are punched to approximately the same shape as that of the developing plate are prepared. The developing plate 3 having ruled line parts and notched parts made by injection molding method is set in each punching parts 4, then bonded to an adhesive sheet. Thereafter silk-screen printing original plate 7 with print ing design is set at a definite position on the developing plate 3 by print positioning apparatus 6. Then a specified ink is applied on the silk-screen, and first coloring ink is transferred onto the developing plate with a brush or rotating roller. After the printing of all developing plates is completed and they are dried, a plate is replaced with a silk-screen printing original plate for new design print. Hence secondary color printing is executed as before, thereafter required number of color printing is executed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a unit of a certain volume such as a tape cassette for a video tape recorder, a floppy disk, a video disk, an optical disk, a magnetic disk, a digital audio disk. The present invention relates to a method for manufacturing a thermoplastic resin container suitable for accommodating products such as sheet films of photosensitive materials, photographic paper, printed boards, etc.

[Prior art]

Thermoplastic resin containers with small volumes such as those mentioned above can be three-dimensionally molded by direct injection molding, but cases that store items larger than a certain volume, such as tape cassettes for video tape recorders, can be molded using direct injection molding. in case of,
Since it is impossible to perform three-dimensional molding using direct injection molding, a method is used in which boxes are manufactured from expanded plates.

Conventionally, the development plate of such a thermoplastic resin container is a thermoplastic resin flat plate of a constant thickness that is extruded from a T-die into a long length.
If necessary, after printing, etc., cut the board to a certain size.
It is called. ) was produced by compressed shading or cutting, punching out the notches, and in some cases foil-stamping or embossing the surface.

However, such conventional manufacturing methods require a large number of man-hours and are inefficient, lack uniformity in the strength of the silicon wire, surface shape, thickness of the developed plate, etc., and in terms of quality, the incidence of defective products is low. Due to the high height and the forced shaping and cutting of the wire, cracks in the wire occurred, the surface of the wire groove became rough, and the appearance was poor due to the adhesion of debris to the cut surface, resulting in cutting allowances. Since Kirikuyo was disposed of, there were inconveniences in terms of cost and industrial waste generation. Furthermore, in terms of quality, notches and other punched edges are crushed and cut scraps are generated, which can fall off during use, and when storing video tape cassettes, for example, these can adhere to the tape. It is also impossible to process dropouts (distortion of sound and images), special shapes that partially change the thickness of rounding for differentiation, and molding of fine letters and shapes. Ta.

Recently, a transparent window has been printed so that the video tape cassette card inside the case can be seen (Utility Model 59-121773, Utility Model 6
O-2674) or an uneven surface was formed on the surface of a transparent or translucent plastic sheet to make it opaque, and the window part was left as a smooth surface to form a transparent window (Utility Model Publication No. 59-1941)
78) A videotape cassette case with a window is disclosed.

However, in this method, the manufacturing cost of the expansion plate is very high because a process for attaching a window is added.

In order to eliminate the above-mentioned drawbacks of the prior art, the present inventor first proposed that a developing plate for such a synthetic resin container be manufactured by injection molding (Japanese Patent Application No. 58-260).
No. 07, Japanese Patent Application No. 59-8442). In other words, it has been considered difficult to injection mold a developing plate with a large area beyond a certain level using thermoplastic resin, and although it has never been attempted, there are limited gate structures, gate positions, resin compositions, molds, etc. It was discovered that a developing plate having a crease line or a notch can be made by injection molding depending on the structure, and that by doing so, it is possible to completely eliminate the drawbacks of the prior art as described above.

[Problem that the invention seeks to solve]

However, various printing methods (silk screen printing, silk screen printing,
Offset printing, flexible printing, gravure printing, tampo printing (curved surface printing), electrostatic transfer printing, hot stamping (foil stamping), transfer printing, inkjet printing, rotary roll printing, etc.] can print a printing layer of one or more colors. Make money (
If necessary, the printing surface of the development board may be treated with corona discharge or ultraviolet irradiation to improve printability, coated with brimer, or provided with an insulating layer to protect the printed surface.] After that, air drying, cold air, hot air, etc. It was necessary to fix the printed layer to the developing plate by wind, infrared irradiation, ultraviolet irradiation, electron beam irradiation, etc.

In general, printing devices use large sheets that can print on multiple pages in order to reduce printing costs.

For this reason, the printing of the development plate of the present invention, which is one sheet each having grooved lines and notches, requires only a major modification of the printing machine, and six pages can be printed at one time using a large sheet. If you try to print the product of this invention using a machine made by a conventional manufacturer, the printing efficiency will be greatly reduced because each sheet will be printed one at a time, which will greatly increase the printing cost. A developing plate with a printing plate can be produced at a very low cost, and there is almost no cost advantage as a developing plate with a print.

The development plate used in the present invention having a cross section and a notch has an average thickness of approximately α3 to 3 cm and an area of 100 crn or more, and the cross section is 20% or more thinner than the average thickness of the expansion plate. Since the thickness is average, if the molten thermoplastic resin composition is not uniformly and quickly transferred from the gate into the mold during injection of the thermoplastic resin, the flow and distribution of the molten resin will become uneven, resulting in uneven thickness and other problems. Problems such as kinking, weld lines, uneven printing, poor adhesion of printing ink, insufficient tearing strength at score lines, and insufficient ball drop strength and tearing strength of the developing plate occurred.

Therefore, the present inventor has conducted various studies in order to create an inexpensive printed thermoplastic resin expansion plate that has high physical strength, good suitability for box making, and has little warpage or kinking, and has achieved the present invention. did.

[Purpose of the invention]

Therefore, an object of the present invention is to create a developing plate having a diagonal line part and a notch part at the same time as injection molding, to print on this developing plate by a long printing method, and to produce a printed thermoplastic resin container made of this. The purpose of this invention is to provide a method for manufacturing the same.

Another object of the present invention is physical strength (tear strength, drop strength,
To provide a method for manufacturing a very inexpensive printed thermoplastic resin container which has high impact strength, etc., has small warping and twisting, has good appearance, is hard to generate scratches, etc.

[Means for solving problems]

The above objects of the present invention are achieved by the method of the present invention described below. That is, a developing plate having a crease line and a notch is made by injection molding using an injection mold (including an in-mold vacuum injection molding mold and a multi-layer mold), and a long plate is formed on this developing plate. This is achieved by manufacturing a printed thermoplastic resin container by printing using a printing method using a table, drying, and then forming a box.

The present invention will be explained in detail below.

The thermoplastic resin used in the present invention has a melt index (M, engineering) of 15 g/10 minutes or more and a melt index of 5.000 kg/c.
It has a bending modulus greater than WP.

M, Engineering, used here is J Engineering S K 7210 (AS
TM D 1238-62T), using an extrusion type blast meter, measure the amount of molten resin flowing out of an Olyice with a diameter of 2.1 mm and a length of 8 mm at 250 ° C. under a load of 2.16 mm. This is expressed in units of 1/10 minute.

In addition, the bending elastic modulus in the present invention is JISK-72 (1
3 (ASTM D-790).

As the thermoplastic resin used in the present invention, any known resin can be used, but in particular, it has a melt index of 15 to 8.
It is preferable to use a polypropylene resin having a heating rate of 0 g/10 min, preferably 20 to 60 F/10 min, particularly preferably 30 to 50 y/10 min, or a polypropylene polymer containing such a polypropylene resin in an amount of 50 F/10 min or more. Examples of polypropylene resins include homopolypropylene, propylene-ethylene block copolymer, fluoropylene-ethylene random copolymer, and fluoropylene-〇s~
010α-olefin copolymer, chlorinated polypropylene, crosslinked polypropylene, etc. may be used alone or as a mixed resin of two or more.

In addition, when the thermoplastic resin contains a polyolefin polymer, the M engineering of the polyolefin polymer is 5.
F7 High pressure process low density polyethylene (LDPE) for 10 minutes or more
), or linear low density polyethylene (L-LDPK)
), ethylene-ethyl acrylate copolymer (EEA)
, ethylene-vinyl acetate copolymer (KVA), and the like.

The present invention uses a polypropylene resin made of a copolymer of propylene and ethylene, and polypropylene and L-LDPL from the viewpoint of improving the adhesion between the developing plate and printing ink, improving the tearing strength of the diagonal line part, and improving the falling ball strength and tearing strength of the developing plate.
li or LDPI! Blend resins with f, synthetic rubber, ERA, and KVA are preferred.

In particular, M work is 15~80W 710 minutes polypropylene resin 50~97TL quantity duck and M work is 5~801/10 minutes linear low density polyester 7 (LinearLow D
strength Po1y-fitylene hereafter I,
-LDPK) Resin composition is preferably 3 to 50% by weight of the resin and 47% by weight or less of additional components other than these.

Furthermore, the thermoplastic resin used in the present invention can contain various additives depending on the purpose.

Representative examples are shown below.

(Additive types) (Typical examples) (1) Plasticizers: phthalate esters, glycol esters, uh fatty acid esters, phosphate esters, etc. (2) Stabilizers: lead-based, cadmium-based, zinc-based, alkaline earth metals (3) Antistatic agents; cationic activators, anionic activators.

Nonionic activator 1 Bifacial active agent, etc. (4) Flame retardant; phosphoric acid ester, halogenated phosphoric acid ester, halide, inorganic substance, phosphorus-containing polyol, etc. (5) Filler: alumina, kaolin, clay, calcium carbonate, mica, talc , ff titanium, crystal strength, etc. (6) Reinforcing agents: Glass roving, metal fibers, glass fibers, glass milled fibers, carbon fibers, etc. (71 Coloring agents: Inorganic pigments (AL, Fe20H, Ti
01. ZnO.

aaa etc.], organic pigments, metal powders, carbon black,
Dyes, etc. (8) Blowing agents; Inorganic blowing agents (ammonia carbonate, sodium bicarbonate) Organic blowing agents (nitronic, azo-based), etc. (9) Vulcanizing agents; Vulcanization accelerators, accelerators, etc. 4 Anti-deterioration agents:
Ultraviolet absorbers, antioxidants, metal deactivators, peroxide decomposers, etc. α-coupling agents; Clan-based, titanate-based, chromium-based, aluminum-based, etc. (6) Thermoplastic resins, rubber, etc. (to) Nucleating agents; various organic and inorganic nucleating agents, etc. A4 lubricants; various types of silicone and olein dispersion amides.

Erucic acid amide, stearic acid amide, etc. The present invention prints on a development plate made by injection molding having a crease line part and a cutout part using a long table printing method, and then manufactures a printed thermoplastic resin container by making a box. Manufacture.

Next, typical steps are shown.

1st process: Vacuum injection molding inside the mold is used to fix the marking lines, and 2nd process: A long stand with adhesive (or the union). 3rd process: A plurality of developing plates are fixed to the fixed die punching frame.

4th process: Printing on multiple pages is done using a printing positioning device. 5th process: After one round of printing (for example, 90 m long), 6th process: The printed thermoplastic resin container obtained in the 5th process is attached by ultrasonic welding, etc. A printed thermoplastic resin container is produced by box-making.

In particular, in-mold vacuum injection molding was proposed by the present inventor as a method for efficiently and inexpensively producing a thin spreadable plate with good appearance and no warpage or kinks, which has such a score line and a notch. The method (Special BH39-F3AA'l) is preferable because it allows molding even if a thermoplastic resin with a low MI is used. In addition, the recent trend of developing plates with transparent windows is made by using a thermoplastic resin with a haze of 80% or less, preferably 40% or less, of a sheet with a thickness of 111+1, and making the transparent window part a smooth surface with a thinner υ thickness. Only one side can be marked with a 7-bore to prevent scratches, and the parts other than the transparent window can be formed at the same time as υ injection molding by increasing the haze by applying 7-bore processing such as unevenness or pear finish. . By using the composite printing method of the present invention on such a transparent window-equipped development plate, printed displays, pictures, designs, etc. can be applied, and a transparent window-equipped development plate with nine prints can be obtained at low cost. The application filed by the present inventor regarding a deployable plate with a transparent window made by injection molding is JP-A-60-73.
There is No. 837 and Japanese Patent Application No. 59-82384.

In the method of the present invention, the most preferable resin composition as a thermoplastic resin base material for injection molding used in injection molding (including in-mold vacuum injection molding) will be described in detail.

Examples of single resins include various polypropylene resins that are the main thermoplastic resins in the blend resin composition described later. Especially in terms of physical strength and injection moldability, MI is 15 to 8027.
It is a copolymer resin of 10% ethylene and propylene, especially a propylene/ethylene random copolymer resin containing 3 mol% or more of ethylene.

In order to satisfy the various properties, the following blend resin composition is particularly preferable for K. The most important main thermoplastic resin in the blend resin composition is polypropylene resin, and various known polypropylene resins such as homopolypropylene resin, propylene/ethylene random copolymer resin, propylene/ethylene block copolymer resin, and isopropylene resin are used. Tactical propylene/Resin, etc., especially propylene, ethylene, etc. containing one or more of various nucleating agents at t = 0.01 to 2% by weight.
Random copolymer resins are superior in terms of cost, printability, dimensional stability, surface strength, rigidity, transparency, injection moldability, etc. The sub-thermoplastic resin is L-LDPK resin.

Linear low density polyethylene (L-LDPK) resin is a copolymer of ethylene and α-olefin, and is a copolymer of ethylene and α-olefin having 3 to 13 carbon atoms, preferably 4 to 10 carbon atoms. It is a polyethylene polymer with a structure of short branches in a linear straight chain, with an ethylene content of 1 to 995 moles, and an α-olefin content of α5.
~10 moles or more are suitable for the present invention.

Polymerization processes include gas phase methods, liquid phase methods, and ionic polymerization methods. Linear low-density polyethylene (L-LDPK) resin is generally produced by a low-pressure method, and the density is generally considered to be low to medium density, but the resins that can be used in the present invention are 187 to [1
, 95r/-, preferably 0
．． 91 to α942/mouth 3.

Butene is an α-olefin that copolymerizes with ethylene.
1, octene-1, hexene-1,4 methylpentene-
Among them, 4-methylpentene-1, hexene-1, and octene-1 are preferably used to improve physical strength.

Specific examples of L-LDPK resins that can be used in the present invention are shown below by trade names: Ceja Uniball (Ace), Dowlex (Dow Chemical), Sflare (DuPont Canada), Stamilex (DSM), Marlex ( ) Iritbus Co., Ltd.), Neozex and Ultzex (Mitsui Petrochemicals), 8 Stone Sunilex (8 Stone Resin Chemicals), NUC
Examples include polyethylene-LL and TUFL-N (Nippon Unicar).Among these LDPK resins, particularly preferred are those containing 81.90 to 995 mol% of ethylene;
a-olefin-containing 11icL 5-10 mole whisper, fox work,
α4~15, density IIL91~α9417cm", α-
Mitsui Petrochemical ■'s Urtozex, which uses 4-methylpentene-1 with 6 carbon atoms as the olefin side chain, is sb,
DSM's Stamilex and Dow Chemical's Dowlex, which use octene-1 with 8 carbon atoms as the α-olefin side chain, are L-LDPK resins manufactured by the liquid phase process. .

As a gas-phase process product, Nippon Unicar's T, which uses hexene-1 with 6 carbon atoms as the α-olefin side chain,
There is UFL Engineering N.

In addition to the main polypropylene resin and sub-OL-LDPK resin, various thermoplastic resins can be used as thermoplastic resins that can be added as necessary, but in particular polyolefin resins (including copolymers with ethylene) or polystyrene resins. etc. are used.

As polyolefin resin, various polyethylene (m
DPwSMDPI! ! , hppm) Kizukiji, ethylene copolymer resin (ethylene/ethyl acrylate) cofi
One or more of a combination of mJIL (ethylene vinyl acetate copolymer resin), an ionomer resin, a polyisobutylene resin, a polybutylene resin, a polycarbonate resin, etc. can be used.

However, from the viewpoint of improving physical properties, polyolefin resins are preferred, such as ItDP, MDP, and HDPK.

PP, BKA%]! It is desirable to use thermoplastic resins such as tVA, ionomers, and polyisobutylene alone or in combination of two or more.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of producing a printed development plate according to the present invention will be described with reference to the drawings.

First, the combination printing method used in the present invention will be explained.

Figure 1) is an explanatory diagram (schematic perspective view) showing an example of the combination printing method of the present invention, and Figure 1 (B) is a partially enlarged plan view showing an example of a punching frame used in the method.

As shown in FIG. 1(A), symbol 1 is a workbench called a pitcher on which a printing material is fixed, and generally has a certain slope to improve workability.

Although only one side is shown in the figure, the opposite side can also be used. It is preferable to use a double-sided adhesive sheet affixed to the entire work surface of the work table during printing, so that the punching frame and the printing material can be easily fixed thereon.

A predetermined number of die-cutting frames 2 for setting development plates (printing material) are fixed on a workbench (double-sided adhesive sheet) (10 frames in this example). 6. The frame 2 is provided with a predetermined number of punched parts 4 (six in this example), which are punched out in almost the same shape as the expansion plate, as shown in FIG. A developing plate 5 made by a rolling injection molding method and having a crease line and a notch is fitted and fixed to the adhesive sheet.

Next, the silk screen printing original plate 7 with a printing pattern is set by the printing positioning device 6 so that the pattern can be printed at a predetermined position on the spread plate s fixed in this manner. For example, the original silk screen printing plate 7 is moved along the rail 5 in the direction of the arrow and set on each developing plate by each positioning device. After setting the printing original plate 7 on the specified development plate (in the figure, the rightmost development plate), place the specified ink on the full screen, and transfer the first color ink onto the development plate using a brush or rotating roller. do. In this example, designs can be printed on six expansion plates at the same time. Next, this printing plate is moved to the next printing positioning device and set, and printing is performed on the next development plate. After printing on all development plates is completed in this way, after drying, replace with a new silk screen printing original plate for solid printing, print the second color as before, and then print the required number of sheets. Perform color printing (note that in the case of monochrome printing, it is of course sufficient to print only the first color).

After all printing is completed, each developing plate is dried, and these printed thermoplastic resin developing plates are peeled off from individual die-cutting frames and manufactured into boxes.

By using the combination printing method in this manner, it is possible to efficiently print a large number of development plates in a short period of time.

FIG. 2 is a schematic sectional view showing an example of an apparatus used for injection molding in the present invention.

Although this example illustrates a mold having one cavity for molding the expansion plate, the present invention is not limited to this, and molding cavities are provided on both sides of the fixed mold, and injection molding is performed from one injection tube. Use a double loss mold that allows molten resin to be supplied to both cavities at the same time, or a multi-layer mold that further increases the number of cavities and allows molten resin to be supplied from one or two injection tubes. I can do it. Further, depending on the case, an in-mold vacuum injection molding method may be adopted in which an exhaust device is provided and the cavity is evacuated before supplying the molten resin.

The illustrated mold is composed of a fixed mold 11, a movable mold 12, and an injection cylinder 15, and a cavity 14 for molding a spread plate is formed between the fixed mold 11 and the movable mold 12, and a hot water molded in the fixed mold 11. Molten thermoplastic resin is supplied to the cavity 14 from the injection tube 15 through a passage 15 .

FIG. 5 is a perspective view showing an example of a printed thermoplastic resin container obtained by the present invention, in which the printed thermoplastic resin container has a rectangular parallelepiped window with an open opening on the negative side. 21Fi, is manufactured by forming a box with a window portion and a printing plate 52 shown in a plan view in FIG.

In FIG. 4, the window and printed development plate 52 are located at the front part
4: Rear surface part 55: Left upper surface part 56: Right upper surface part 37: Left placement surface part 58: Right bottom surface part 39: Back surface part 40: Flaps 41, 4
1a: A thermoplastic resin container 21 with a window and a print as shown in Fig. M3 is formed by forming a box from the crease line part 42 and the window part 50. In Figure 5,
The correspondence of each part of the development plate in Fig. 2 is flag 41, 41
It is filled in except for a and the groove line part 42.

Conventionally, a thermoplastic resin container 21ra with a window and a print as shown in FIG. After cutting a thermoplastic resin flat plate to make a rectangular plate with notches and windows marked with diagonal lines in FIG. Then, a hatched cutout 43. 44
．． 45° 46 and the window part 50 are punched and further the window part 5 is formed.
A transparent or semi-transparent sheet was applied to the 0, and in some cases, the front part 34 etc. were embossed to create a development plate, which was then manufactured into a box.

According to the present invention, the window portion and the printed expansion plate 32 as shown in FIG. A thermoplastic resin container 21 with a window and a print as shown in FIG. 3 is produced by injection molding in a shape having irregularities on the parts and the like, and by forming the container into a box as shown in FIG. Depending on the need, it is possible to produce thermoplastic resin containers without windows and with a transparent or printed thermoplastic resin container colored in various colors.

In the method of the present invention, various thermoplastic resins can be used as the thermoplastic resin used in injection molding, as described above, including polypropylene resin, polyolefin thermoplastic resin (including copolymer resin with other thermoplastic resins). ), or a polystyrene thermoplastic resin, a M B8 thermoplastic resin, or a mixed resin of two or more of these thermoplastic resins, especially those with a melt index of 50% by weight or more (M engineering) 1
Thermoplastic resin which is polypropylene resin of 5-80t/10min, and said polypropylene resin 50-97 weight factor and M work 5-80? Mixed resins consisting of /min L-LDPK resin and the rest other components, especially polypropylene resins containing 0.01 to 2 parts by weight of various nucleating agents, are propylene/ethylene random copolymer resins that have low cost, printability, It is suitable in terms of manufacturing accuracy, dimensional stability, crease line strength, surface strength, rigidity, suitability for injection molding, etc.

These thermoplastic resins used in the present invention are blended with aluminum powder. If necessary, these thermoplastic resins may contain various blowing agents and white pigments (as described above).
titanium oxide, Merck, mica, calcium carbonate, clay, etc.), various carbon blacks, various white pigments and colored pigments, various metal powders and metal fibers, various organic or inorganic fibers such as glass fibers, carbon fibers, etc. Various additives such as various coloring dyes, antistatic agents, various silicones, surfactants, lubricants such as sodium stearate, and antioxidants can be added.

Furthermore, when injection molding is performed in the method of the present invention, the injection port (gate) for the molten thermoplastic resin is not limited to one location, but can be provided at multiple locations.
The flow of the thermoplastic resin improves during injection molding, and it is possible to prevent the occurrence of a boundary line where the flow of the thermoplastic resin joins, which is called a weld line. These resin injection ports (gates) are located inside the container as shown in Figure 4 in order to improve the fluidity of the thermoplastic resin in the case of a structure in which the external appearance of the container and the cross section are provided only on the surface of the container. "l
, Yt, Ys (typically pin gate), or notch 4
3.44.45.46 product end (represented by side gate), left and right overlapping portion 37.39 or flap 41.
It is preferable to deposit the thermoplastic resin at one or more locations on the front, back, and end portions of 41a, preferably in the vicinity of left-right or vertically symmetrical positions, where the thermoplastic resin can flow to the four corners in approximately the same amount of time. Particularly preferably, when the injection port (gate) for the thermoplastic resin is to be provided at only one location, it is provided at the position XI yl in FIG. In addition, if it is provided in two places, it is provided at the positions Yl and Ys in Fig. 4.

Another example of creating two locations is xl and x3 in Figure 2.
It is also preferable to place it in the position of

Note that sxl-engine *""X4 and Yt%7 snow""74 is the distance between each gate.

In any case, in the present invention, the number of υ resin injection ports (gates) depends on the shape of the developing plate, the fluidity (melt index) of the thermoplastic resin, the ease of generating gate marks, the ease of generating weld lines, etc. However, the present invention is not limited to the above description, and any number or shape can be adopted at any position on the expansion plate, making it suitable for injection molding and ensuring that the surface of the container (visible It is preferable from the viewpoint of appearance and fluidity of the resin to prevent it from appearing on the surface.

In the present invention, aluminum powder, white or colored pigments, etc. are added to the thermoplastic resin to improve the appearance, and silicon compounds such as siloxane, surfactants such as saponin, or stearic acid, etc. are used. Lubricants such as higher fatty acid metal salts, oleic acid amide, erucic acid amide, alkyl amine, bis fatty acid amide, etc. are added to Cl, 01~
By adding 5 weight, the fluidity and moldability during molding are improved.
It is possible to improve the mold releasability and the slipperiness after molding.

Also, by adding an antistatic agent to the thermoplastic resin, it is possible to make it difficult for dirt and dust to adhere to the container, or by adding a foaming agent to the thermoplastic resin, the appearance of the container can be changed and the texture can be improved. Lightening may also be implemented selectively.

When manufacturing a printed thermoplastic resin container 21 as shown in FIG. 3 by the method of the present invention, it is preferable that the developing plate 32 as shown in FIG. 4 has a cross-sectional shape as shown in FIG. m5. Furthermore, although the crease lines are provided only on one side of the expansion plate in FIG. 6, they may be provided at symmetrical positions on both sides as shown in FIG.

The plate thickness t Fi (L is generally from about 5 m to about 3 m, and the crease line part is thinned by 20% or more, preferably 1j40 or more, most preferably 60% or more with respect to the average plate thickness t of the developed plate. A development plate having a notch and a score line,
The occurrence of warping and twisting is small, making it easy to form boxes. In the present invention, the thickness of the expansion plate 32, which is an injection molded product, is (1L3~3■
The crease line area should be at least 20% of the plate thickness t, preferably 40%, in order to prevent warping and sinking when printing ink sticks, to ensure fluidity of the thermoplastic resin, and at the same time to facilitate box manufacturing.
It is necessary to reduce the thickness by 0% or more, most preferably by 60% or more, and from the viewpoint of strength, it is necessary to ensure a thickness of at least α1- or more.

In the present invention, the front, back, entire surface or front part 3 is
4. The outer or inner surfaces of the rear surface part 55, left upper surface part 56, right upper surface part 37, left placement surface part 38, etc. can be embossed, engraved, grooved, or recessed to improve the appearance and handling properties. It will be held in In conventional manufacturing methods, these were performed by embossing, but in the method of the present invention, these surface treatments can also be performed during injection molding.

In addition, according to the present invention, a developing plate with a transparent window can be created during injection molding, and if necessary, decoration can also be applied during injection molding (in-mold decoration can also be used in the injection molding method of the present invention. ].

In contrast, in conventional manufacturing methods, gates are created using T-dies,
It was an expensive product that required numerous steps: surface treatment, printing, drying, punching into the required shape with notches, manual punching, stamping, and foil stamping. .

In particular, the process of creating a surface with a transparent window was complicated and resulted in a lot of loss, making it extremely expensive.

The present invention has been described above with respect to a method for manufacturing boxes of a specific shape, but the present invention is not limited thereto and can be applied to manufacturing containers of various shapes.

〔Example〕

Next, in order to further clarify the effects of the present invention, examples are listed below.

(1) A double stacked four-cavity mold having two cavities for injection molding on both sides as shown in FIG. 2 was used. As a printing device, a combination printing device shown in FIG. 1 was used. In this case, the gold was designed so that the dimensions of each development plate were as follows. The resin injection port (gate) is located on the inside of the expansion plate in Fig. 4 (inner bottom surface in contact with the items stored in the box) Yt+Y
There were two locations of s.

Vertical and horizontal dimensions of the unfolding plate: The longest part is 247 x 237 wm Thickness of the unfolding plate is 20.8 mm Dimensions of the transparent window part 20 of prototypes 1 to 3 of the present invention: Height 70 w x
Width: 90wm, thickness: α6■ Prototype rods 1 to 3 of the present invention have only the window section on the front/farmer/military smooth surface, other than the window section are the front/farmer/military embossed.Prototype 4.5 of the invention has no window and the front/farmer/military is entirely embossed. Deployment plate (thickness CL8) Dimensions of the line part: Width 1.5 m, thickness α25- Cross-sectional shape of the line part: As shown in Fig. 5 Notch part 45.4
Dimensions of 4: Length approximately 70 gourds, depth 20 gourds Dimensions of notch 45.46: Polygon with longest part 37 m x 28 sm (2) Using this mold, melted thermoplastic resin having the composition shown in Table 1 was molded. In-mold vacuum injection molding was performed: the results are shown in Table 1.

(3) Using a large-sided punching frame as shown in Fig. 1, hand silk screen printing the pattern shown in Fig. 4 using silk screen printing ink of the type shown in Fig. 1, and printing on a printed thermoplastic resin development plate. It was created.

(4) Assemble the printed thermoplastic resin expansion plate 32 printed using the combination printing method described in (3) and weld the overlapping parts using an ultrasonic welder to obtain an approximate size of 192w x 105.
A videotape cassette case having a beautiful uniform appearance and thickness of mX280 was manufactured.

Conventional cutting and punching when the number of boxes manufactured is 300,000 pieces,
Compared to manufacturing methods that include strip stamping, transparent window frame printing, and foil stamping processes, the manufacturing cost is reduced to 40%, and the incidence of defective products is reduced by conventional methods, including edge loss, cutting/cutting loss, and die line area loss. Compared to 11% in the method, it was less than 1% in the method of the present invention.

〔Effect of the invention〕

According to the method of the present invention, as the number of man-hours is reduced as described above, the manufacturing cost is reduced, the wire tearing strength, the tearing strength of the developing plate, the falling impact strength, etc. are improved, and the warpage and twisting of the developing plate are greatly reduced. The board thickness and wire thickness are uniform, and the box manufacturing performance and flatness are also improved.

In addition to stabilizing the manufacturing process, there is no cutting waste,
Appearance, reduced scratches, improved accuracy, improved quality of finished surfaces, improved strength of wires, improved shading, and uniform thickness of the development plate, resulting in significant effects such as automation of work and reduction of industrial waste. Obtainable.

The present invention is not limited to the embodiments, and can be widely applied, for example, as shown below.

(1) The shape of the expansion plate is not symmetrical; for example, the shape of the front part and the shape of the back part may be different.

(2) Even if the thickness of the side part is the same as the remaining thickness of the crease line part, the strength can be maintained by overlapping and joining.

(3) The shape of the notch is rectangular, square, trapezoidal, semicircular,
It can have various shapes such as a semi-ellipse, an equilateral triangle, an isosceles triangle, and an arrow shape.

(4) The remaining thickness of the crease line may be partially increased to improve the flow of resin during vacuum injection molding within the mold.

(5) The surface of the mold has been processed to have a transparent window in one or more places on the development plate, and the inside and outside surfaces of the case are not engraved with the product name, company name, picture, etc., or have silky, sandy, or knotted grains. , vertical stripes, horizontal stripes, lattice patterns, fine grain surfaces, textures, etc. (graining).

More than 210 types of 1 Bearon 7bo published by Tokyo Bearon■ are presented as specific grained samples.

(6) In injection molding, the thermoplastic resin can be a copolymer resin or a mixed resin of two or more types of thermoplastic resins.

(7) Thermoplastic resin contains 1 color pigment or color dye.
A species or multiple species can be added.

(8) After the development plate is vacuum injection molded in a mold, a printing process or a labeling process can be selectively added before or after the box manufacturing process to add marks or letters.

(9) It is possible to make an injection-molded thermoplastic resin developing plate with a transparent window, a print, and a thermoplastic resin molded base material having a haze degree of 80% or less, preferably 40% or less.

The printing method of the present invention on the development plate having the grooved lines and cutouts can be roughly divided into various known printing methods such as letterpress printing, planographic printing, silk screen printing, intaglio printing, and curved surface printing, preferably silk printing. Screen printing, gravure printing, halftone gravure printing, offset printing,
It is effective to use curved surface printing (tampo printing), flexographic printing, hot stamping printing (foil stamping printing), etc.

αυ After setting up a developing plate with grooves and notches, print on it using the above QC) method and apply ink within 50 minutes using air, heat, hot air, infrared rays, vacuum, ultraviolet rays, electron beam, etc. Forced practical reaction fixation or dry fixation can be carried out.

(6) The mold is not only the conventional single-layer (single-layer) single-chamfer mold, but also a multi-layer (multi-layer) metal mold with two or more layers (double-layer), and injection molding is used. By putting multi-chamfer into practical use, productivity can be increased several times and costs can be significantly reduced.

(G) A convex portion can be provided on the inside of the case body to prevent the product from falling.

α◆ As the printing ink used in the present invention, any known ink can be used, but particularly preferred are one-component type silk screen printing ink, two-component type silk screen printing ink, and ultraviolet curing ink. .

(To) As the injection molding method, it is effective to use an in-mold vacuum injection molding method in which injection molding is performed by evacuating the inside of the mold, in addition to the generally widely used injection molding method.

Injection molding (including in-mold vacuum injection) of a developing plate with a diagonal line and a notch can be used not only for a book-shaped container with an opening on the α01 side, but also for all types of containers such as one-piece containers with front lids fitted. This can be applied if it is possible to print by a post-pouring printing method created by molding) and then form a container into a container.

(b) In addition to ultrasonic bonding, methods for assembling and joining the overlapping parts of the expansion plates include adhesive bonding using adhesives, rotational welding, hot plate welding, and vibration welding (using low-frequency vibration). Various methods can be used, such as hot air welding, locking, friction, and screw joining.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a typical example of a combined printing method, Fig. 2 is a schematic diagram showing an example of an injection molding apparatus used in the present invention, and Fig. 3 is a printed thermoplastic resin manufactured by the present invention. An external view of a book kennis type container for a video tape case with a transparent window and a print showing an example of a manufactured container, Figure 4 is a plan view of the unfolding plate of the container shown in Figure 3, and Figure 5 is a diagram showing the same structure as in Figure 4. FIG. 6 is a cross-sectional view of the development plate in the Mu B plane, and is a cross-sectional view showing another aspect. 1... Pitching 2... Die punching frame 3.
...Development plate 4...Punching portion 6...Positioning device 7...Silk screen printing original plate 21...Thermoplastic resin container 52...Development plate with printing 42...Screen line portion 43~
46...Notch part 1! ! I (B) Figure 2 Figure 3 Proceedings Ne...English Book (Rei) March 4, 1986 1st Edition Commissioner of the Office Uga 11 Kuchi 5 Indication of Tono Incident 1985 Patent Application No. 180564 Name of Invention Relationship with the person who amends the packaging method of printed thermoplastic resin containers: Patent applicant

Claims (1)

[Claims] 1) After creating a development plate having a crease line and a notch by injection molding (including in-mold vacuum injection molding), printing is performed on the development plate by a long table printing method, and this is manufactured. A method for manufacturing a printed thermoplastic resin container characterized by being a box. 2) The method for manufacturing a printed thermoplastic resin container according to claim 1, wherein the long table printing method is a hand silk screen printing method using a long table. 3) In the long platform printing method, a punching frame for positioning the development plate is used to enable simultaneous printing of a plurality of development plates. A method for manufacturing the printed thermoplastic resin container described above. 4) The thermal printing method according to any one of claims 1 to 3, wherein the printing ink used in the long platform printing method is a one-liquid type silk screen printing ink. Method for manufacturing a plastic resin container. 5) Any one of claims 1 to 4, characterized in that the die-cutting frame for positioning the development plate in the long platform printing method is thinner than the development plate. A method for producing a printed thermoplastic resin container according to . 6) The printed thermoplastic resin container according to claim 2, wherein the silk screen for silk screen printing has an angle of 30 to 60 degrees with respect to the printing direction. Production method. 7) At least 50% by weight of the resin composition of the developing plate is a polypropylene resin with a melt index of 15 to 80 g/10 minutes, and four or more developing plates are positioned on a long platform so that printing can be performed by hand at once. A developing plate having grooves and notches made by injection molding is placed in a die-cutting frame with a thinner wall than the developing plate to be used, and is printed using silk screen printing ink using a long-table hand-printing silk screen printing method, and then manufactured into a box. A method for manufacturing a printed thermoplastic resin container according to claim 1. 8) The method for manufacturing a printed thermoplastic resin container according to claim 7, wherein the ink used in the long printing method is an ultraviolet curing ink.