JPH0596620A - Manufacture of label consisting of laminated film - Google Patents

Abstract

PURPOSE:To improve the impact resistance and heat shrinkability of a label by a method wherein polystyrene-based film, which has specified thickness and coefficient of thermal shrinkage at the predetermined temperature, is laminated onto both the sides of polyolefin film, which has the predetermined coefficient of thermal shrinkage at the same temperature as mentioned above and the difference between the coefficient of thermal shrinkage of which and that of polystyrene at the above-mentioned temperature is specified, in the manufacturing method of the label, which is wound round a container. CONSTITUTION:The label concerned is produced by laminating polystyrene-based film, which is made of general-purpose polystyrene or the like having the thickness of 0.015-0.05mm, onto both the sides of polyolefin film or the 1ike, which has the coefficient of unidirectional thermal shrinkage at 130 deg.C of the polystyrene-based film is set to be 25-80%. At the same time, the difference between the coefficients of unidirectional thermal shrinkage of the polystyrene- based film and of the polyolefin film at 130 deg.C is set to be within 40%. Thus, the resultant label can be wound round a one-way glass bottle or the 1ike with solvent and brought into close contact with the bottle of the like by being thermally shrunk through the application of heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a label which is used by being wrapped around a container.

[0002]

2. Description of the Related Art Conventionally, one-way glass bottles and PE
Polyvinyl chloride resins and polystyrene resins are predominantly used in heat-shrinkable plastic films or sheets used as labels wrapped around T bottles. However, polyvinyl chloride resin has a problem of harmful gas generated during incineration. Further, a foamed sheet or a non-foamed film processed from a polystyrene resin has low impact resistance and its use range is restricted. On the other hand, polypropylene resin labels have also been developed, but they have excellent impact resistance, but their heat shrinkability is weaker than the above resins, their production speed is low, and they do not adhere to glass bottles or PET bottles. There is also a problem that rinsing water or a liquid containing a filling material may enter between the container and the label. Further, a label made of polypropylene resin is difficult to be stuck by a solvent, and is not suitable for a labeler in which the end faces of the label are superposed with a solvent and wound.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a solvent having excellent impact resistance and heat shrinkability, which is a solvent. It is to provide a label that can be wrapped and wound.

[0004]

Means for Solving the Problems Under the circumstances described above, the present inventors have earnestly studied the label to be wound around a glass bottle or a PET bottle, and as a result, a label in which a polystyrene film is laminated on both sides of a polyolefin film is effective. It was found that there is something, and the present invention has been completed. That is, the above object of the present invention is achieved by using a polyolefin film and a polystyrene film having a specific heat shrinkage. More specifically, a label in which a polystyrene film is laminated on both sides of a printed polyolefin film using an adhesive, or a polystyrene film on one side is printed and then laminated so that the polyolefin film is in the middle. It is a method of manufacturing a label.

The present invention will be described in detail below. The polyolefin film in the present invention is selected from resins such as polyethylene, polypropylene, ethylene-vinyl acetate resin, ethylene-propylene copolymer resin, and preferably polyethylene resin. Furthermore, this film has a heat shrinkage ratio of 2 in one direction at 130 ° C.
It is 5% or more, preferably 30% or more. The difference from the heat shrinkage of the polystyrene film is 40% or less in the same bonding direction. If the heat shrinkage rate in one direction at 130 ° C. is less than 25%, the shrinkage label is restricted or the label winding speed is reduced. Also, when the difference between the heat shrinkage ratio of the polystyrene film in one direction exceeds 40% at a temperature of 130 ° C., when the laminated film is heated, small wrinkles occur, or the polyolefin film and the polystyrene film are separated from each other. Or The thickness of the film used is 0.01 to 0.1
0 mm is preferable. If the thickness is less than 0.01 mm, the impact resistance becomes insufficient and the loss also increases in the printing process. On the other hand, when the thickness exceeds 0.10 mm, wrinkles are formed when laminating the polystyrene films and winding them into a roll. Further, it is preferable that both front and back surfaces of this film are subjected to corona treatment.

The polystyrene film used in the present invention is composed of general-purpose polystyrene (GPPS), high-impact polystyrene (HIPS), styrene-butadiene, maleic anhydride, methacrylic acid, and a copolymer resin of styrene. Also, rubber for the purpose of adjusting flexibility and heat shrinkage performance,
There is no problem even if an elastomer or a plasticizer is added or an antistatic lubricant or the like is added.

The thickness of the polystyrene film is 0.01
The heat shrinkage rate in one direction at 130 ° C. is 5 to 0.05 mm and 25 to 80%. Thickness is 0.015mm
When the amount is less than the above, loss is large even in the printing step, and the strength of winding the laminated label on a glass bottle or a PET bottle and adhering the end face is insufficient. If it exceeds 0.05 mm, it is difficult to stack and roll it up. If the heat shrinkage in one direction is less than 25%, the label is restricted or the label winding speed is reduced. Heat shrinkage rate is 80
If it exceeds%, it will be torn in the printing process and the loss will increase. Further, it is preferable that the laminated surface of this film is subjected to corona treatment. Printing is performed on the boundary surface between the polyolefin film and the polystyrene film, but it does not matter whether the printing is performed on the polyolefin film or the styrene film. A polyolefin film is preferable. The adhesive applied on the boundary surface between the polyolefin film and the polystyrene film is preferably a polyurethane adhesive. The polyurethane-based adhesive is an adhesive obtained by reacting a normal polyisocyanate having two or more isocyanate groups per molecule with a polyether or polyester having hydroxyl groups at both ends. Specifically, hexamethylene diisocyanate, lysine diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylenecyclohexane 2,4
(2,6) diisocyanate, 1,3- (isocyanatomethyl) cyclohexan, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, metal xylene diisocyanate An adhesive obtained by reacting a compound containing two or more isocyanate groups per molecule with a polyester, polyether, glycol or the like having a hydroxyl group at the terminal. Preferred is a two-pack type adhesive obtained by reacting a water-adducted polyisocyanate of hexamethylene diisocyanate with a polyester having hydroxyl groups at both ends, for example, Trademark Adcode AD (manufactured by Toyo Morton Co., Ltd.), Trademark Orestar. Some are commercially available under the names such as NP-1100 / NL-2448 (manufactured by Mitsui Toatsu Chemicals, Inc.). To apply the polyurethane adhesive to the boundary surface between the polyolefin film and the polystyrene film, a normal dry lamination device can be used. Even if the polystyrene film is laminated on both sides of the polyolefin film at one time, one side can be used. There is no difference even if they are stacked one by one. The coating amount of the polyurethane adhesive is preferably in the range of 0.5 to 5 g / m ² . A laminated film of a wide polyolefin film and a polystyrene film thus printed is cut into a desired width for one row and then wound up. The printing film, which is continuously repeated in one line, is cut into individual labels at a predetermined position by a machine for winding the labels on the container to form the labels, and at the same time, the print films are wound on the glass bottles or PET bottles. Further, depending on the shape of the container, the label is heated and brought into close contact with the glass bottle or PET bottle.

[0008]

EXAMPLES The present invention will be described below with reference to typical examples. Example 1 [Polyolefin film] High-density polyethylene (Hi-Zex, manufactured by Mitsui Petrochemical Co., Ltd.) was used as a raw material, melted by an extruder, extruded from a T-die, and stretched in the flow direction. The thickness is 0.025 mm, and it is 3 in a 130 ° C oil bath.
Shrinkage rate when immersed for 27 minutes in flow direction (MD)
%, And 2% in the transverse direction (TD).
This film was subjected to double-sided corona treatment, and then a pattern was printed on one side. [Polystyrene film] 20 parts by weight of a styrene-butadiene block polymer (K resin; manufactured by Philips), GPPS (Topolex; manufactured by Mitsui Toatsu Chemical) 75
Parts by weight and HIPS (Topolex; manufactured by Mitsui Toatsu Chemical)
B. 5 parts by weight with a 40 mmΦ extruder. U. The film was formed by the inflation method with R of 2.3, and when heated at 130 ° C., the flow direction (MD) was 65% and the perpendicular direction (T
A film having a thickness of 0.025 mm, which is 11% in D).
The polyethylene film and the polystyrene film were attached to each other with a two-component polyurethane adhesive (Ad Code; manufactured by Toyo Morton) to obtain a laminated film having a three-layer structure. The thermal shrinkage of this film (immersion in an oil bath at 130 ° C. for 3 minutes) was 45% in MD and 5% in TD. This laminated film was slit into a ring shape having a width of 100 mm and then cut into a length of 220 mm to obtain a label.
Wrap the label along a glass bottle with a body diameter of 67 mmΦ and a shoulder of 40 mmΦ, and wrap the mating part with tetrahydrofuran (T
HF) was adhered to form a cylindrical body. After that, the label was heated together with the glass bottle so as to be closely attached to the bottle. The label did not delaminate even when heated, and the appearance after shrinkage was beautiful. Vibration test in which bottles with this label are repeatedly collided with each other (9 test samples are placed in a cardboard box, 120 cycles / minute of vibration is performed for 10 minutes,
The appearance of the label was not broken and the joint was not peeled off.

Examples 2 to 4 Laminated films were prepared in the same manner as in Example 1 except that the polyolefin film or polystyrene film shown in Table 1 was used. The evaluation of the produced film was also performed in the same manner as in Example 1, and the results are shown in Table 1. The appearance after shrinkage was also good, and the label was not broken and the mating part was not peeled off even when the labeled glass bottle was subjected to a vibration test.

[0010]

[Table 1]

Comparative Examples 1 to 4 Laminated films were prepared in the same manner as in Example 1 except that the polyolefin film or polystyrene film shown in Table 1 was used. Also, the evaluation of the produced film was performed in the same manner as in Example 1, and the results are also shown in Table 2. When the polyethylene film has a small heat shrinkage rate at 130 ° C., the product value was lost because the polyethylene film did not shrink uniformly even after being wrapped around a glass bottle and heated to further adhere. When the difference in shrinkage between polyethylene and polystyrene film was large, heating the laminated film caused many small wrinkles on the shoulder and bottom of the bottle. On the other hand, the shrinkage rate of polystyrene film is
If it is less than 25% at 130 ° C., even if the laminated film is heated, it does not shrink uniformly and the commercial value is lost. In addition, when the thickness of the polystyrene film is small, a poor appearance occurs in the vibration test.

[0012]

[Table 2]

Comparative Example 5 A label was prepared and evaluated in the same manner as in Example 1 except that the urethane adhesive was changed to an ethylene / vinyl acetate copolymer. When the shrinkage occurred, the laminated sheet had many wrinkles and the appearance was poor.

[0014]

EFFECTS OF THE INVENTION According to the present invention, a label having excellent heat shrinkability, impact strength and transparency can be obtained. That is, the heat shrinkability was improved by laminating the polystyrene film, and it became possible to adhere the label to a glass bottle or a PET bottle. Also, this label is
Since the polystyrene film is laminated on both sides of the polyolefin film, not only the overlapping part can be heat-bonded but also solvent-bonded, and the selection range of machines that can use this label has expanded.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location G09F 3/04 C 7028-5G 3/10 C 7028-5G (72) Inventor Nishiba Shizo Tokyo Nihonbashi Hakozaki-cho 6-9 Sun Lily Co., Ltd.

Claims (3)

[Claims] 1. A method for producing a label, which comprises a laminated sheet in which a polystyrene film is laminated on both sides of a polyolefin film, wherein the polystyrene film has a thickness of 0.015 to 0.05 mm and a heat shrinkage in one direction at 130 ° C. 25-80%, and the heat shrinkage ratio of the polyolefin film in one direction at 130 ° C. is 25.
%, And a method of manufacturing a label, which uses a film having a difference of 40% or less from a heat shrinkage ratio in one direction of the polystyrene film. 2. A method for producing a label comprising a laminated film according to claim 1, wherein printing is performed on a boundary surface between the polyolefin film and the polystyrene film. 3. The method for producing a label comprising a laminated film according to claim 1, wherein the polyolefin film is a polyethylene film.