JPS5817781B2 - pressure sensitive adhesive tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure-sensitive adhesive tape, and more particularly, it provides a pressure-sensitive adhesive tape with excellent sealing properties and oxygen-blocking effects.

Due to contact with oxygen, for example, food products may suffer from spoilage or deterioration, and fur products may develop mold.

This problem can be solved, for example, by packaging with a multi-layered hermetic film, but such a packaging form is not desirable for food products due to the commercial value. It is often stored or transported in containers.

Although the container body or lid itself has sufficient oxygen blocking ability, since there are minute gaps between the container body and the lid, oxygen may enter through these gaps and cause food to rot or deteriorate. Because of this, I try to seal the gap and block oxygen by pasting cello adhesive tape, semi-hard polyvinyl chloride tape, etc. across the main body and lid, but the tape itself stretches unnecessarily. A combination of various factors can result in uneven thickness, poor oxygen blocking ability of the tape itself, or failure to absorb the difference in level formed by the end of the tape overlapping the beginning of the end. The reality is that the oxygen blocking effect has not been achieved.

As a result of various studies in view of the state of the prior art, the inventors of the present invention have developed a technology that prevents oxygen from entering by skillfully combining a tape support with specific properties and a pressure-sensitive adhesive shaft layer with specific physical properties. We have discovered a pressure-sensitive adhesive tape that can be used, and have led to the present invention.

That is, the present invention provides a pressure-sensitive adhesive tape that is wound on the surface of an application body with its winding start part and winding end part overlapping, and the tape is composed of a tape support and a pressure-sensitive adhesive layer, The tape support has a 5% mozilla support of 9 mm/20 mm or less in width and a width of 10 m to 17 m".24
hrs (20°C x 80 coefficient R, H0) or less, and the pressure sensitive adhesive layer has an oxygen permeability of 0.5 to 4'q/c
characterized by having an elastic modulus of ffl;
The present invention provides a pressure-sensitive adhesive tape with excellent sealing properties.

The tape support used in carrying out the present invention is 5L
:l) Modulus is 9ky/20mm width or less, 10m
l/m” -24hrs (20℃ x 8o%R,H
, ) or less, there is no particular limitation.

However, if the 5-thread modulus is 9 to 9/2Orrrm width or more, the tape will be undesirably elongated and difficult to wind evenly, and the oxygen permeability will be 10ml/
m2・24 hrs (20℃xs o %R,H,)
The above is undesirable because too much oxygen enters into the container from the tape support.

Tape supports that satisfy these conditions include, for example, a composite film of polyester film and aluminum foil, a polyester film coated with polyvinylidene chloride, a film made of cellophane coated with polyvinylidene chloride, and a biaxially oriented polypropylene film. Film coated with polyvinylidene chloride,
Examples include a film made of a partially saponified ethylene-vinyl acetate copolymer, and a film made of polyamide coated with the above partially saponified product.

The pressure-sensitive adhesive layer provided on the surface of such a tape support has an elastic modulus (measured by tangential modulus) of 0.5 to 4 kg/i, and an elastic modulus of 0.5 kg/i.
If the tape is stored wrapped around the surface of the body to which it is applied, the adhesive layer will bulge out due to the tension during winding, and
If it exceeds kg/i, the level difference formed by the winding start part and the winding end part superimposed thereon will not be absorbed and a so-called water channel will be formed, which is not preferable.

The material of the adhesive is not particularly limited, and adhesives mainly made of rubber and/or synthetic resin are used.

The thickness of the adhesive layer is usually 20 to 100 μm, but it is preferable to form the adhesive layer so that it covers about half of the total thickness of the pressure-sensitive adhesive tape. absorption becomes easier, and the effect of eliminating the formation of water channels can be obtained more reliably.

According to the tape of the present invention, it is possible to completely block oxygen from entering the container even when it is applied over the container body and the wrapping body, and even when it is pasted so that the beginning and end of the winding overlap the end of the winding. It has the characteristic of not causing spoilage or deterioration of the food inside.

Examples of the present invention will be shown below.

Example A tape support shown in Table 1 is prepared.

Next, the following pressure-sensitive adhesive layers A, B and C are formed on the tape support shown in Table 1 to obtain the pressure-sensitive adhesive tape of the present invention.
The two pieces were overlapped, and the above tape was wrapped so that the end of the winding overlapped with the beginning of the winding.The state of oxygen permeation was visually judged. (The sensor is sealed with an oxygen scavenger that can adsorb oxygen, and a detection agent that initially contains oxygen and is deoxidized by the oxygen scavenger and has the ability to adsorb oxygen).

The measurement results are shown in Table 2.

A: Acrylic pressure-sensitive adhesive layer (modulus of elasticity 1.1 kg/i) B: Rubber-based pressure-sensitive adhesive layer (modulus of elasticity 0.7 kg/i)
C Niblock copolymer rubber pressure sensitive adhesive layer (elastic modulus 3
．． (Okg/cri'i) In Table 2, permeation was determined based on the number of hours it took for the oxygen detecting agent in the Petri dish to change color due to oxygen.

In this test method, a material that can block oxygen for two days or more can be used.

From Table 2, it can be seen that the tapes of samples A1 to A7 have oxygen blocking ability.

In addition, in Samples 9 and 10, tapes whose adhesive layer was thicker than the tape support had sufficient oxygen blocking ability, but tapes whose adhesive layer was thicker than the tape support had no oxygen blocking effect. I understand.

Claims (1)

[Claims] 1. A pressure-sensitive adhesive tape that is wound on the surface of an application body with its winding start part and winding end part superimposed, and the tape is composed of a tape support and a pressure-sensitive adhesive layer, and the tape support The 5th modulus of the body is 9kg/20m.
m width or less and 10m1/m2-24 hrs
(20℃xs O%R4H0) or less, and the pressure-sensitive adhesive layer has an elastic modulus of 05 to 4 kg/crrt, and the pressure-sensitive adhesive tape has excellent sealing properties. .