JPH0216944B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides pressure-sensitive adhesion only between coating layers formed by coating on the surface of a tape-shaped base material such as cellophane, cloth, kraft paper, or rubber sheet, and is non-touchable to other objects. The present invention relates to so-called self-adhesive tapes which have the property of being substantially non-adhesive.

Ordinary adhesive tapes have an adhesive layer formed by applying a rubber-based or acrylate-based adhesive to the surface of a tape-shaped base material, and the adhesive force of the adhesive layer allows the tape to adhere to the surface of an article, etc. It is used to package or bundle the articles, etc.

Therefore, when temporarily binding or sealing a bundle of documents, a rolled calendar, drafting paper, etc. with such adhesive tape, the tape cannot be peeled off from the surface of the item later. When removing the tape, printed characters, designs, etc. on the surface of the article, or in some cases the surface of the article itself, would be peeled off along with the tape. Further, after the tape is peeled off, the adhesive may remain attached to the surface of the article, and dust and the like may adhere to this, resulting in staining of the surface of the article.

Therefore, the present invention does not adhere to the surfaces of the articles to be packaged or bound, but uses pressure-sensitive adhesive bonding only between the tape surfaces, so that the surfaces of the articles to be packaged or bound are not stained or damaged. It is an object of the present invention to provide a self-adhesive tape that can be wrapped or bundled reliably.

In order to achieve this object, the present invention provides a self-adhesive tape that pressure-sensitively adheres only between coating layers coated on the surface of a tape-shaped base material and does not substantially adhere to other objects. A coating layer is formed by coating and drying an ethylene-vinyl acetate copolymer emulsion on one or both sides of the tape-shaped base material.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing an example in which the self-adhesive tape T1 according to the present invention is used to bind a bundle of documents P, and FIG.
The figure is a cross-sectional view taken along the line --.

As shown in FIG. 2, the self-adhesive tape T1 is produced by coating and drying an ethylene-vinyl acetate copolymer emulsion on both sides of a tape-like base material 1 made of cellophane or the like to obtain a desired film thickness (for example, 5μ to 20μ). Coating film layers 2, 2 having the following are formed.

The ethylene-vinyl acetate copolymer emulsion forming this coating layer 2 contains 10 to 30% by weight of ethylene.
is an emulsion copolymerized with vinyl acetate.

This ethylene-vinyl acetate copolymer emulsion (hereinafter referred to as EVA emulsion) is generally used as an adhesive material, and adhesives based on it can bond well with plastic films and other materials that cannot be bonded with ordinary adhesives. It also has the characteristics of extremely fast adhesion speed and good water and alkali resistance.

Such adhesives are applied, for example, to the joint surfaces of the objects to be bonded together, and after bonding, the solvent and moisture in the adhesive evaporate and solidify, thereby firmly bonding the objects together. However, if the solvent or water is evaporated and solidified before bonding, the adhesive no longer exhibits substantial adhesion to the surface of the article.

However, the inventor has discovered that the EVA emulsion coating film applied to an object and dried and solidified is
They discovered that these EVA emulsions exhibit pressure-sensitive adhesive properties, and as mentioned above, they noted that this EVA emulsion adheres well to plastic films, cellophane, etc., and is water resistant, and took advantage of these properties. Through this process, the self-adhesive tape of the present invention was completed.

For example, EVA emulsion in which 20% by weight of ethylene is copolymerized with vinyl acetate (solid content
55%) (Bond SP235, manufactured by Konishi Co., Ltd.) 100 parts by weight, 10 parts by weight of water as a solvent component, and a wetting agent to improve "wetting", that is, application property, to one side of the tape-shaped base material. A mixture of 1 part by weight of Nopko Wettsu (trade name of San Nopco Co., Ltd.) was applied to a 18-inch cloth coated with moisture-proof coating such as polyvinyl chloride on both sides.
mm moisture-proof cellophane tape (MST manufactured by Tohcello Co., Ltd.)
A self-adhesive tape T1 according to the present invention was manufactured by uniformly coating both sides of a tape-shaped substrate 1 made of #400) and drying to form coating layers 2, 2 with a thickness of about 15 μm.

Then, the two samples cut from the tape thus completed were stacked one on top of the other, and the respective coating layers were pressure-sensitive adhesive bonded to each other (overlap margin: 25 mm).
While the free end of one sample was fixed, tension was applied along the tape longitudinal direction from the free end side of the other sample.

The average adhesive strength between the coating layers in this horizontal peel test was approximately 4.60 kg under conditions of temperature 20°C and humidity 45%.

In addition, in place of the bond SP235, ethylene
EVA with 10% by weight copolymerized with vinyl acetate
Emulsion (solid content concentration 55%) (Bond S-
300, manufactured by Konishi Co., Ltd.) to produce self-adhesive tape T1 in the same manner as above, and at a temperature of 15°C.
A similar peel test was conducted under conditions of 42% humidity, and the average adhesive strength between the coating layers was approximately 3.85.
It was Kg.

The adhesive strength between the coating layers 2 of the self-adhesive tape T1 manufactured in this way is sufficient to be applied to binding a bundle of documents P as shown in FIG.
While the document stack P can be firmly tightened, the coating layer 2 exhibits no adhesive property to the document stack P at all.

As described above, according to this embodiment, since the coating layers 2, 2 are formed by coating and drying EVA emulsion on both sides of the tape-shaped base material 1, for example, as shown in FIG. When binding the bundle P, simply wrap the self-adhesive tape T1 around the document bundle P and press the overlapping part G with your finger under tension.
You can do this. In addition, the EVA resin that forms the coating layer 2 does not have adhesive properties to other objects when it is dry and solidified, so it will not adhere to bound documents, etc., and therefore, self-adhesive tape When T1 is peeled off from the document bundle P, the document is not damaged or its surface is not stained.

Next, FIG. 3 is an explanatory view showing an example in which the self-adhesive tape T2 according to the present invention is used directly as a packaging for an article, and FIG. 4 is a sectional view taken along the line --.

As shown in the figure, the self-adhesive tapes T2, T2 according to the present invention are formed by coating and drying an EVA emulsion on one side of a relatively wide tape-like base material 1 made of cellophane to form a coating layer 2. The coating layers 2 and 2 are pressed together by rubber feed rollers R1 and R2, and at the same time, a relatively thin article M such as a stamp, coin, button, or photograph is placed between them. It is used as a so-called combination packaging tape for sandwiching and sealing packaging.

Here, the EVA emulsion applied to the tape-like base material 1 forms an extremely transparent coating layer 2 when it dries and solidifies, and since this EVA resin has a property of good water resistance, stamps, etc. It is particularly suitable for packaging for photographs and the like.

In addition, as shown in FIG. 4, the self-adhesive tape T2 has an EVA resin coating layer 2 formed on one side.
If another vinyl polymer adhesive made by polymerizing vinyl monomers such as vinyl acetate, acrylic ester, or vinyl chloride is applied to the other side and dried to form a coating layer. Since the coating layer 2 adheres to the coating layer with an adhesive strength on the order of kg, it is possible to obtain a self-adhesive tape having the same uses and functions as shown in FIGS. 1 and 2. can.

As described above, according to the present invention, by simply forming a coating layer by coating and drying an EVA emulsion on one or both sides of a tape-shaped base material, pressure-sensitive adhesive bonding can be achieved only between the coating layers. However, it is possible to easily obtain a so-called self-adhesive tape that does not adhere to other objects, and since this tape has good transparency, it can be used directly as a packaging tape to allow the contents to be seen from the outside. It has excellent effects and is suitable for use in

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an example of the self-adhesive tape according to the present invention used for bundling articles, Fig. 2 is a cross-sectional view taken along the line ``-'', and Fig. 3 is an illustration showing another example of the self-adhesive tape according to the present invention. FIG. 4 is an explanatory view showing an example in which it is directly used as a package for articles, and FIG. 4 is a cross-sectional view taken along the line --. Explanation of symbols, T1, T2...Self-adhesive tape,
1... Tape-shaped base material, 2... Paint film layer.

Claims (1)

[Claims] 1. A self-adhesive tape that pressure-sensitively adheres only between coating layers formed on the surface of a tape-shaped base material and does not substantially adhere to other objects,
A self-adhesive tape characterized in that a coating layer is formed by coating and drying an ethylene-vinyl acetate copolymer emulsion on one or both sides of the tape-shaped base material.