JPS588752Y2 - Adhesive sheet for heat-resistant labels - Google Patents

Description

[Detailed explanation of the invention] Conventionally, heat-resistant labels that are used by being attached to adherends that have been heated to a high temperature of approximately 150°C or higher are pasted onto a release base coated with a silicone release agent before use. in a state of
When using this, it is peeled off from the release base material surface using an automatic label issuing machine or by hand, and is used by pasting it on the target high-temperature adherend. Vinyl-based adhesives can cause the rubber to deteriorate due to the high heat of the adherend.
The adhesive strength of acrylic or vinyl polymers decreases or completely disappears due to washing away, thermal decomposition, carbonization, etc., resulting in the inconvenience that the adhesive state of the label cannot be maintained and the label peels off.

Therefore, it is thought that if the above adhesive is replaced with a silicone adhesive made of polysiloxane, good adhesiveness can be maintained without thermal deterioration even in the high temperature range of 200°C to 500°C, but for the following reasons. The heat-resistant label adhesive sheet is unsuitable for manufacture and use, and is therefore impractical.

That is, when bonding a heat-resistant label base material coated with a silicone adhesive to a release base coated with the above-mentioned silicone release agent, the silicone adhesive and silicone release agent have good compatibility, so the The silicone release agent surface acts more as a bonding agent than as a release agent, and serves to strongly adhere the label substrate to the release substrate.

Therefore, an appropriate display is printed on the surface of the label base material,
Next, cut only the label base material by half die cutting.
When removing unnecessary portions of the label base material other than the shape of the face-contact label cut into a □□ shape from the surface of the release base material, that is, when so-called "removal of scraps", a good compatibility between the adhesive and the release agent is required. Due to solubility, unnecessary parts of the label base material cannot be peeled off from the release agent, and therefore a heat-resistant label adhesive sheet cannot be obtained.

The present invention is a peelable base material that does not have such inconveniences and can be easily peeled off from the label base material, and can also be used to adhere to high heat adherends to withstand high heat and maintain good label adhesion over a long period of time. The heat-resistant label adhesive sheet 1 has a silicone adhesive layer 2 and a rubber, acrylic or vinyl adhesive layer 3 sequentially formed on one side. The product is bonded to a release base material 5 coated with a release agent 4.

Embodiments of the invention will be described with reference to the accompanying drawings.

1 is heat-resistant plastic film, sorting, metal foil,
A heat-resistant label base material made of noncombustible paper or the like is shown, and a silicone adhesive layer 2 made of adhesive polysiloxane and a rubber-based, acrylic-based or vinyl-based adhesive are formed on one side of the base material 1, that is, on the adhesion side. It is constructed by coating and forming two layers, including layer 3.

The rubber adhesive is an elastomer made of natural rubber or synthetic rubber, mixed with a rosin-based or terpene-based tackifier, and the acrylic adhesive is made of 2-ethylhexyl acrylate or butyl acrylate. It is polymerized mainly from acrylate monomers.

The vinyl adhesive is mainly made of polyvinyl isobutyl ether or the like.

A release base material 5 impregnated with a silicone release agent 4 or coated in a layer on one side is prepared, and the Nolabel base material 1 is attached to the release agent 4 side with its rubber-based acrylic or vinyl adhesive layer 3. Together, they constitute the adhesive sheet (AK) for heat-resistant labels of the present invention.

The release base material 5 is made of glassine paper, bleached kraft paper, polyethylene laminate paper, plastic film, sheet, or the like.

Reference numeral 6 indicates an anchor coating agent layer for printing ink formed by coating on the label base material 1, which improves the adhesion of printing ink when applied to the surface of the label base material 1.

When label-processing the heat-resistant label adhesive sheet A' of the present invention to produce a heat-resistant label adhesive sheet A', print on the front tube of the label base material 1 with a sticker printing machine as usual, and then print on the label base material side. After performing a half-die cutting process in which the peeling base material side is not cut, the so-called "residue lifting" is performed to peel off unnecessary parts 1a other than the label shape from the peelable base material surface 4. Let's do it.

In such a case, since the adhesive surface of the label base material 1 is bonded to the silicone release agent surface 4 with a rubber, acrylic or vinyl adhesive layer 3, it can be easily peeled off and the second As shown in the figure, a heat-resistant label pressure-sensitive adhesive sheet A' is obtained in which an unnecessary part, that is, a waste portion 1a of the label base material can be peeled off, and a large number of labels Ib (printed surfaces not shown) remain on the peelable base material 5.

The label 1b on the surface of this sheet product is then peeled off and pasted onto an adherend to be used for its label display function. For this reason it is easily obtained.

Peeling is performed continuously or at appropriate times using an automatic label printing machine or by hand.

The peeled label 1b is placed on the adherend B to be heated,
At room temperature or when heated to about 150°C to 500°C, the rubber, acrylic, or vinyl adhesive layer 3 is partially removed by lateral force at various places as shown in the third figure. Then, the inner silicone adhesive layer 2 is partially exposed at the removed portion, and the exposed silicone adhesive 2 is attached to the surface of the adherend 8 (5c).

Thus, even if the adherend B is heated to a high temperature of, for example, about 300°C and the adhesive 3 is altered or carbonized by the heat, the silicone adhesive 3, which has excellent heat resistance, will maintain its tackiness even at high temperatures. Since it does not deteriorate, the state of adhesion of the label 1b to the adherend B can be maintained in good condition.

Therefore, for this purpose, the silicone adhesive layer 2
is relatively thick, for example, about 15 to 30μ, and the rubber, acrylic, or vinyl adhesive layer 3 is relatively thin, for example, about 5μ, so that the above-mentioned label can be attached to the adherend B. Can be pasted.

Of course, the heat-resistant label provided by the present invention can also be used for attachment to adherend B at room temperature or at a relatively low temperature where rubber, acrylic, or vinyl adhesives do not deteriorate; Generally, the label is attached to the rubber or acrylic adhesive layer 3, and it is clear that there is no need to expose and attach the label to the silicone adhesive layer 21 inside thereof.

In this way, according to the present invention, a silicone-based adhesive layer 2 and a rubber-based, acrylic-based or vinyl-based adhesive layer 3 are formed on one side of a heat-resistant label base material 1, and a silicone-based release agent 4 is applied thereto. Since the heat-resistant label adhesive sheet was laminated to the 5 sides of the release base material, the adhesive layer 3 was used as the border.
Not only is the label processing label easy to peel off from the 5 sides of the peeling base material, but also the adhesive layer 2 can be easily peeled off when using the label.
By sticking on the surface, it is possible to maintain long-term label adhesion with excellent heat resistance, especially to the object B that is heated to a high temperature of about 200 to 500°C.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a portion of an example of the present invention, FIG. 2 is a perspective view during label processing, and FIG. 3 is a sectional view of the device in use. 1...Heat-resistant label base material, 2...Silicone adhesive layer, 3...Rubber, acrylic or vinyl adhesive layer, 4... - Silicone release agent, 5... Release base material, 1b... Label.

Claims (1)

[Scope of utility model registration request] A heat-resistant label base material 1 on which two layers, a silicone-based adhesive layer 2 and a rubber-based, acrylic-based or vinyl-based adhesive layer 3 are sequentially formed on one side, is placed on the 5th side of a release base coated with a silicone-based release agent 4. Adhesive sheet for heat-resistant labels made by pasting together.