JPH0830174B2 - Adhesive tape for encapsulation of cardboard boxes - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure-sensitive adhesive tape for sealing corrugated cardboard boxes, which uses a supporting base material made of a plastic film that has been subjected to a release treatment with a silicone-based release agent and which can be overlaid.

2. Description of the Related Art Conventional techniques and problems In the field of adhesive tapes for sealing cardboard boxes, since silicone-based release agents are too good for their release ability and cannot be laminated on the back side, use thereof is, for example, kraft paper laminated with polyethylene film. It was limited to kraft paper-based support substrates such as. That is, in the kraft paper-based support substrate, the adhesive force between the laminate film and the kraft paper is weak and easy to cause delamination, and in order to prevent this, a peelable treatment layer having a weak adhesive force with the pressure-sensitive adhesive layer is desired. Silicone release agents have been used to satisfy the requirements. Therefore, in this case, there is a problem due to the weak adhesive force to the back surface, for example, the above-mentioned overlapping cannot be performed, the wound material is easily collapsed into a bamboo shoot, and due to the rotational inertia of the tape roll. Problems such as rewinding more than necessary have been accepted from the light and heavy selection of the required performance in use.

When priority is given to what cannot be achieved with conventional silicone-based release agents such as layering, a plastic film made of polypropylene, polyester, etc. is used as a supporting substrate, and these are backed with a long-chain alkyl-based release agent. The processed one has been used.

However, in the case of the back-treated with a long-chain alkyl-based release agent, contrary to the one using the above-mentioned conventional silicone-based release agent, although it can be laminated,
The adhesive force between the self-back and the adhesive layer is too strong, and the force required to rewind the tape winding is large, which is inefficient in the corrugated cardboard box sealing work, and a loud noise called a squeaking phenomenon is generated during rewinding. It occurred and had a problem that was not desirable from the viewpoint of working environment.

Means for Solving the Problems The present inventors have overcome the above-mentioned problems, can perform over-pasting on the back surface of the self, and can smoothly rewind a wound material with a sound that does not cause a problem. As a result of intensive studies to develop a viable pressure-sensitive adhesive tape, it was found that the object can be surprisingly achieved by using a combination of a silicone release agent and a plastic film, and the present invention has been completed. .

That is, the present invention relates to an adhesive tape for sealing a cardboard box in which a pressure-sensitive adhesive layer is provided on the other surface of a support base material having one surface subjected to a release treatment, wherein the support base material is a release-treated plastic film with a silicone release agent. And a peeling force of the pressure-sensitive adhesive layer to the back of itself is 5 to 25 g / 25 mm, and a shear adhesive force is 1 to 2.5 kg / 10 mm. It is a thing.

Action By combining the silicone release agent with the plastic film, the low release force of the silicone release agent is utilized and the flexibility of the plastic film is utilized, and the satisfactory shear adhesive strength is achieved under these synergistic effects. Occurs, and the intended purpose is achieved.

Examples of constituent elements of the invention The pressure-sensitive adhesive tape of the present invention is for sealing a cardboard box, and as a supporting base material thereof, a plastic film such as a polypropylene film, an ethylene / propylene copolymer film or a polyester film is used. .

The thickness of the supporting substrate, that is, the thickness of the plastic film is 10 to 100 μm, preferably 30 to 70 μm. If the thickness is less than 10 μm, the strength is insufficient.
When it exceeds m, flexibility is insufficient and satisfactory shear adhesive strength is not exhibited.

The surface of the supporting base material subjected to the peeling treatment is preferably subjected to surface oxidation treatment by a corona discharge method or the like from the viewpoint of preventing separation of the treated layer. It is suitable that the surface tension be about 38 dynes / cm.

The pressure-sensitive adhesive tape of the present invention is obtained by treating one surface of the above-mentioned supporting substrate with a silicone-based release agent.

The silicone-based releasing agent is not particularly limited, and known ones such as solution-based or oligomer-based condensation-curing type or addition-reaction-curing type can be used.

Treatment with silicone release agent has a solid content of 0.05-5g
/ m ² , preferably 0.2 to ² g / m ² is appropriately diluted with a solvent according to the viscosity of the silicone-based release agent is applied to a predetermined surface of the support substrate and dried by heat treatment or the like. It is performed by forming a solidified film.

The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer on the other surface of the supporting substrate, one surface of which is treated with a silicone-based release agent.

As the adhesive constituting the adhesive layer, JIS Z 0237
Based on the above, the peeling force (180 degree peeling) of the adhesive layer from the back surface of the adhesive tape is 5-25g / 25mm, and the shear adhesive force is 1
The one with a weight of ~ 2.5kg / 10mm is used. Its peeling force is 25
If it exceeds g / 25 mm and the shear adhesive strength exceeds 2.5 kg / 10 mm, the force required for rewinding the wound product will be too large and the workability will be poor. Sound will be generated. On the other hand, if the peeling strength is less than 5 g / 25 mm and the adhesive strength for shearing is less than 1 kg / 10 mm, the adhesive strength against the back surface is insufficient and it will peel off naturally when stacking with H (cross) or the like. Become.

A typical acrylic adhesive, a rubber adhesive, as a typical example of the adhesive having the adhesive property to the back surface,
Examples thereof include styrene-isoprene-styrene block copolymer adhesives.

The pressure-sensitive adhesive can be applied by a conventional method such as a method of applying a solution dissolved in a solvent or a method of applying as an aqueous or non-aqueous emulsion, depending on its characteristics.
The coating amount is appropriately ²⁰ to 50 g / m ² based on the solid content.

The support substrate coated with the pressure-sensitive adhesive is heated and dried, and then wound into a roll on a ball core or the like, cut into a predetermined width if necessary to be a wound product of the pressure-sensitive adhesive tape, and placed in a distribution process. .

EFFECTS OF THE INVENTION According to the present invention, a plastic film is used as a supporting substrate, and the adhesive tape is treated with a silicone-based release agent. Therefore, based on the synergistic effect of the combination, a wound product that does not collapse is obtained. In addition, the rewinding can be smoothly performed with an appropriate force with a noise that does not cause noise, and the re-bonding can be performed on the back surface of itself. Therefore, it is possible to seal the cardboard box with excellent reliability.

Example Example Biaxially oriented polypropylene film with a surface tension of 38 dynes / cm after surface oxidation treatment by corona discharge method (thickness 40
(μm) surface, a commercially available silicone-based release agent (KS-705F, catalyst PS-1, manufactured by Shin-Etsu Chemical Co., Ltd.) consisting of a condensation-curing silicone resin, diluted with toluene (solid content 5% by weight) is solidified with a kiss coater. After coating so that the coating amount was 0.5 g / m ² , this was heated in an oven at 100 ° C. for 5 minutes to dry the solvent and cure the silicone release agent.

Next, on the other side of the biaxially oriented polypropylene film provided with a treated layer of a silicone-based release agent, a natural rubber-based pressure-sensitive adhesive having a usual composition (100 parts by weight of natural rubber, petroleum-based resin (manufactured by Nippon Zeon Co., Quinton D- 100) 100 parts by weight, anti-aging agent 2
Parts by weight, 2 parts by weight of isocyanate-based crosslinking agent, the same applies hereinafter)
Was coated so that the solid content coating amount was 30 g / m ^2, and then this was subjected to heat drying treatment.

The obtained product was wound around a ball core having a diameter of 75 mm for a length of 50 m in a roll shape and then cut into a width of 25 mm to obtain a wound adhesive tape.

Comparative Example 1 Treated with a long-chain alkyl-based release agent (solid content: 0.5 g
/ m ² ), a biaxially oriented polypropylene film (thickness 40 μm) with a natural rubber adhesive layer (solid coating amount 30 g / m ² ).
A commercially available adhesive tape consisting of was used.

Comparative Example 2 Treated with a silicone release agent (solids coating amount 0.5 g / m
² ), a commercially available adhesive tape made of a kraft paper base material (thickness 120 μm) having a natural rubber adhesive layer (solid content of 30 g / m ² ) was used.

Evaluation test The following measurements were performed on the pressure-sensitive adhesive tapes obtained in Examples and Comparative Examples.

[Peeling Force] The pressure-sensitive adhesive layer was attached to the release-treated surface of the pressure-sensitive adhesive tape, and the force required for peeling the pressure-sensitive adhesive tape was measured according to JIS Z 0237 (180-degree peeling method).

[Rewinding force] The force required to rewind the pressure-sensitive adhesive tape was measured according to JIS Z 0237 (rewinding speed 30 m / min).

[Generated Volume] The sound volume was measured at a position 30 cm away from the tape during the rewinding force measurement.

[Shear Adhesion] Measured according to the superposition method of JIS Z 0237.

[Sealing] The workability when sealing the cardboard box was judged.

[Overlaying property] Put 20kgf of contents into the A type cardboard box and seal through the overlaying of the adhesive tape and repeat the test of letting it fall naturally by the height of 1m to check the state of the overlaying part. It evaluated by the standard of.

5: If peeling does not occur at all even after repeating the drop test 10 times 4:10 If part of the end of the overlapped part peels off and part of the tape floats in the 10th drop test 3: 5th time If part of the end of the overlapped part is peeled off and part of the tape floats in the drop test in step 2: Part of the end of the overlapped part peels off and part of the tape floats in the third drop test. In the case where 1: 1 drop test peeled off the end of the overlapped portion and the tape floated, the above results are shown in the table.

In addition, the numerical value of the generated sound volume in the table means a value exceeding the numerical value of the normal atmosphere of the 60 horn, and the actual generated sound volume is a value obtained by adding 60 to the numerical value in the table. Therefore, for example, the actual generated sound volume when the numerical value in the table is 3 is 63 horns.

As is apparent from the examples in the table, the pressure-sensitive adhesive tape of the present invention has an appropriate rewinding force, a small sound volume at the time of rewinding, and can be rewound without a squeaking phenomenon. Moreover, it has sufficient adhesive force for stacking.

Continuation of the front page (56) Reference JP-A-61-136571 (JP, A) JP-A-52-6384 (JP, A) JP-A-62-22881 (JP, A) JP-A-52-6385 (JP , A) JP-A-51-139835 (JP, A) JP-A-62-292867 (JP, A)

Claims (2)

[Claims] 1. A pressure-sensitive adhesive tape for sealing a cardboard box, comprising an adhesive layer provided on the other surface of a supporting base material having one surface subjected to a release treatment, wherein the supporting base material is a plastic film release-treated with a silicone release agent. The peeling force of the pressure-sensitive adhesive layer to the back surface is 5-25g / 25mm, and the shear adhesive force is 1-
Adhesive tape for enclosing corrugated cardboard boxes, which is 2.5 kg / 10 mm and can be stacked. 2. The plastic film has a thickness of 10 to 100 μm.
2. The adhesive tape according to claim 1, which is a polypropylene film, an ethylene / propylene copolymer film or a polyester film.