JP2955089B2 - Surface protective adhesive tape or sheet with low static electricity generation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape or sheet suitable for protecting the surface of a metal product or the like from scratches or the like which are likely to occur when storing, transporting and processing the product. More specifically, the present invention relates to a surface protective pressure-sensitive adhesive tape or sheet in which electric shock caused by static electricity generated during laminating and peeling operations in winter is extremely reduced.

[0002]

2. Description of the Related Art Surface protective adhesive tapes or sheets (hereinafter collectively referred to simply as "adhesive tapes") are used for processing, transporting or storing metal products, plastic products, and the like. In order to prevent scratches, contamination and corrosion, the surface is temporarily coated, and after achieving the above-mentioned purpose, it can be easily and integrally peeled off.

[0003] As a substrate of such a surface protective adhesive tape, polyvinyl chloride, polyethylene, polypropylene,
Plastic materials such as polyester are used. In particular, a metal product such as a metal plate is heavy and difficult to handle, and is easily damaged due to a large load when it comes into contact and a load when processing. For this reason, a thick tape is often used, and an adhesive tape based on polyvinyl chloride is generally used. Also, in the case of metal products mainly made of stainless steel products such as wall materials and roof materials, they are often left outdoors for about 2 months, and in many cases about 6 months,
During that time, it is necessary to maintain the function as a protective film, and an adhesive tape based on polyvinyl chloride having excellent weather resistance is used.

Heretofore, since a metal plate manufacturer performed bonding of a surface protection tape and a metal plate using a bonding machine, the bonding machine was previously provided with a static eliminator. However, in recent years, with the upsizing, diversification, miniaturization, and short delivery time of metal plates, lamination has often been performed at small factories close to the consuming area. In such small factories, electric shock due to static electricity is regarded as a very problematic problem because lamination may be performed by a simple laminating machine without a static eliminator or an unskilled worker may operate the lamination.

Conventionally, as a measure against static electricity, a method in which a commercially available antistatic agent is blended with a base material or a pressure-sensitive adhesive, or a plasticizer such as dioctyl phthalate (DOP) is blended to increase the flexibility of the base material or the pressure-sensitive adhesive. For this reason, even if static electricity is generated as a result, a method has been adopted in which the static electricity is immediately released or the amount of generated static electricity is reduced.

[0006] However, commercially available antistatic agents are generally surfactants, and when an adhesive tape prepared by mixing this with a substrate or an adhesive is adhered to an adherend, the antistatic agent is exposed to the surface of the adherend. And the adhesive remains on the surface of the adherend after peeling. Also,
When a large amount of an antistatic agent is mixed, a large amount of the adhesive remains on the surface of the adherend, and it becomes necessary to wipe off contaminants from the metal plate.
In order to prevent such surface contamination, depending on the thickness of the tape, generally, the amount of the antistatic agent is 0.5% by weight.
It is desirable to make the following. However, with such an amount, the effect of the antistatic agent is small, and it is not possible to prevent electric shock due to generation of static electricity.

[0007] When a large amount of a plasticizer such as DOP is added, the amount of static electricity generated is reduced due to a decrease in surface resistance, and the mechanical force applied at the time of laminating and peeling is reduced due to an increase in flexibility. As a result, the amount of generated static electricity is reduced. However, on the other hand, the characteristics as an adhesive tape changed,
That is, the base film is soft and easily stretched, and has a drawback such as a decrease in the tape width at the time of lamination, which is not a true improvement. An object of the present invention is to provide a surface-protecting pressure-sensitive adhesive tape or sheet which is less likely to generate electric shock due to static electricity while maintaining the characteristics of a conventional pressure-sensitive adhesive tape.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that by blending ethylene oxide-modified dioctyl phthalate with a base material and / or an adhesive, the surface of the substrate at the time of peeling is reduced. The present inventors have found that an adhesive tape or sheet for surface protection with less contamination and less electric shock can be obtained, and the present invention has been completed.

That is, the present invention relates to an adhesive tape or sheet comprising a plastic film as a substrate and an adhesive applied to the substrate, wherein the substrate and / or the adhesive contain ethylene oxide-modified dioctyl phthalate (hereinafter, referred to as “dioctyl”). Surface-protected pressure-sensitive adhesive tape or sheet containing ethylene oxide-modified DOP).

[0010] In the pressure-sensitive adhesive tape or sheet of the present invention, the ethylene oxide-modified DOP is blended in the substrate and / or the pressure-sensitive adhesive. In the method, the ethylene oxide-modified DOP is transferred from the adhesive layer to the base material, and a pressure-sensitive adhesive tape of the same embodiment is obtained.

As a base material of the pressure-sensitive adhesive tape or sheet, a plastic film such as polyvinyl chloride, polyethylene, polypropylene and polyester is used. Polyvinyl chloride is preferred in terms of mechanical strength and weather resistance.

The modified ethylene oxide DOP used in the present invention is obtained by modifying DOP with ethylene oxide. Suitable commercial products of such ethylene oxide modified DOP include Sansosizer C-1100 (manufactured by Shin Nippon Rika Co., Ltd.), Diasizer D-931 (manufactured by Mitsubishi Kasei Co., Ltd.), Plasizer M-100 [Kyowa Hakko Co., Ltd. )
And the like, but the same antistatic effect can be obtained by using any of them.

The amount of the ethylene oxide-modified DOP in the pressure-sensitive adhesive and / or the substrate is 3 to 25% by weight, preferably 6 to 13%, based on the total weight of the pressure-sensitive adhesive and the substrate. 3
%, There is no sufficient antistatic effect. If it exceeds 25%, not only the cost is increased but also the base material becomes soft and easily shrinks. In addition, there is a tendency for surface contamination due to the passage of time to occur. When the amount is 3 to 6%, a quaternary ammonium salt is preferably used in combination with 0.05 to 0.1% by weight as a surfactant. If the quaternary ammonium salt is further added, the heat resistance of the polyvinyl chloride film is inferior, the production of the film becomes difficult, and surface contamination is liable to occur.

The adhesive may be acrylic or rubber.
The same effect is obtained. In particular, in the case of an acrylic pressure-sensitive adhesive, an antistatic effect is obtained irrespective of the type of the base film, and the effect can be seen even when a transparent film is used. In the case of a rubber-based pressure-sensitive adhesive, if a polyvinyl chloride film containing 5 to 10% by weight of a black pigment or a film in which a white film and a black film are combined is used, surface contamination is reduced.

In the present invention, a plasticizer such as DOP, a filler, a stabilizer, an antioxidant, and the like may be added to the substrate and the pressure-sensitive adhesive, if necessary. When a plasticizer such as DOP is added, if added in a large amount, the deformation at the time of laminating or peeling becomes remarkable, so that the total weight% of the ethylene oxide-modified DOP and DOP is 40% by weight in the total weight of the base material and the adhesive. %, Preferably in the range of 25 to 33% by weight.

The production of the pressure-sensitive adhesive tape or sheet of the present invention comprises:
This can be done by means known per se. Normal,
It is manufactured by applying a pressure-sensitive adhesive composition on a formed plastic film and forming a pressure-sensitive adhesive layer.
The thickness of the substrate is usually 70 to 180 μm, preferably 100
And the thickness of the pressure-sensitive adhesive layer after drying is usually 5
-20 µm, preferably 8-13 µm.

[0017]

The present invention will be described more specifically with reference to the following examples. In addition, "parts" means parts by weight. Example 1 100 parts of polyvinyl chloride resin, dioctyl phthalate (D
OP) 23 parts, a composition comprising ethylene oxide-modified DOP (Sansoizer C-1100, manufactured by Shin Nihon Rika Co., Ltd.), 2 parts of a polyvinyl chloride stabilizer, and 5 parts of titanium dioxide was formed to a thickness of 100 μm. The film was obtained to obtain a polyvinyl chloride film. On the film, an acrylic copolymer [butyl acrylate: acrylonitrile: acrylic acid = 8
0: 20: 2 (weight ratio) copolymer), 100 parts
An adhesive composition comprising 23 parts of DOP, 5 parts of polyisocyanate resin, and 7 parts of ethylene oxide-modified DOP (described above) was applied to a thickness of 10 μm after drying to prepare an adhesive tape.

Example 2 An adhesive tape was produced in the same manner as in Example 1 except that the DOP in the polyvinyl chloride film was changed to 8 parts and the ethylene oxide-modified DOP was changed to 21 parts.

EXAMPLE 3 A composition comprising 100 parts of polyvinyl chloride resin, 30 parts of DOP, 7 parts of ethylene oxide-modified DOP (described above), 2 parts of polyvinyl chloride stabilizer, and 5 parts of carbon was coated to a thickness of 10 parts.
A film was formed to a thickness of 0 μm to obtain a polyvinyl chloride film. 75 parts of a methyl methacrylate modified natural rubber on the film,
A pressure-sensitive adhesive composition comprising 25 parts of a terpene resin (YS resin, manufactured by Yasuhara), 2 parts of a thiuram-based vulcanizing agent, and 5 parts of ethylene oxide-modified DOP (described above) is applied after drying so as to have a thickness of 10 μm. Was prepared.

Comparative Example 1 A composition comprising 100 parts of polyvinyl chloride resin, 30 parts of DOP, 2 parts of polyvinyl chloride stabilizer, and 5 parts of titanium dioxide was formed into a film having a thickness of 100 μm to obtain a polyvinyl chloride film. . An acrylic polymer (Example 1) was formed on the film.
100 parts of DOP, 30 parts of DOP, and 5 parts of polyisocyanate resin.
It was applied so as to have a thickness of 0 μm to prepare an adhesive tape.

Comparative Example 2 A composition comprising 100 parts of polyvinyl chloride resin, 23 parts of DOP, 2 parts of polyvinyl chloride stabilizer, 5 parts of titanium dioxide and 5 parts of carbon was formed into a film having a thickness of 100 μm to form polyvinyl chloride. A film was obtained. Methyl methacrylate modified natural rubber (described above) 75 parts, terpene resin 25 parts, thiuram-based vulcanizing agent 2 parts, ethylene oxide modified DOP (described above) 5
After drying, the pressure-sensitive adhesive composition was applied to a thickness of 10 μm to prepare a pressure-sensitive adhesive tape.

COMPARATIVE EXAMPLE 3 A quaternary ammonium salt was added as an antistatic agent to a base material and an adhesive having the same composition as in Comparative Example 1 in an amount of 0.5 part in the base material and 10 parts in the adhesive to form an adhesive. A tape was made.

Comparative Example 4 A quaternary ammonium salt was added as an antistatic agent to a substrate and an adhesive of the same composition as in Comparative Example 1 in an amount of 0.5 part in the substrate and 0.5 part in the adhesive. Thus, an adhesive tape was produced.

Test Examples The pressure-sensitive adhesive tapes obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were evaluated. Evaluation method (1) Initial adhesive strength A tape having a predetermined width (20 mm) was placed at 23 ° C. × 60% RH.
Adhesion is made to a SUS430BA plate (washed with toluene) with a rubber roller, left for 30 minutes, and then peeled off in a 180 ° direction with a universal tensile tester (Tensilon) as adhesive strength. The pulling speed is 300 mm / min. (2) Adhesion over time The one adhered to the SUS430BA plate by the method of (1) is stored for one month in a room temperature of 40 ° C.
After leaving in a 3 ° C. × 60% RH room, the adhesive strength is measured by the method of (1). (3) Surface contamination A tape is stuck on a mirror-finished stainless steel plate (# 800 polishing)
Leave it indoors or outdoors (in the direction of 30 ° southward) for one month, three months, or six months, and visually observe the surface for contamination. A: No change is observed. (Even if the direction of light reflection is changed, it cannot be seen at any angle.) 〇: Slight contamination is seen when viewed at some angles of light. Δ: contamination is observed at any angle even when the angle of light is changed. X: The pressure-sensitive adhesive becomes a layer and adheres to the adherend. (4) Presence or absence of electric shock When a 1000 mm wide tape is rewound at a speed of 30 m / min, the presence or absence of impact perceived by a human under the conditions of a temperature of 10 ° C. and a humidity of 50% RH is evaluated. There is a shock that makes the human body feel uncomfortable. None ... No or no static electricity is felt on the human body. (5) Generated amount of static electricity As the static electricity measuring device, KS-471 manufactured by Kasuga Electric was used. When the tape is rewound at a speed of 30 m / min, the value at a distance of 10 cm from the sheet surface and 5 seconds after the start of the measurement is defined as the amount of generated static electricity. Table 1 shows the base material composition and the pressure-sensitive adhesive composition of Examples and Comparative Examples. Table 2 shows the results of the evaluation test.
Shown in

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

The pressure-sensitive adhesive tape or sheet of the present invention, in which ethylene oxide-modified DOP is blended in the base material and / or the pressure-sensitive adhesive, generates a very small amount of static electricity at the time of lamination and peeling, and has very little electric shock. In addition, adhesion is good,
Since there is no surface contamination, it is useful as an adhesive tape or sheet for surface protection of various products, especially metal products.

Claims (2)

(57) [Claims] An adhesive tape or sheet comprising a plastic film as a base material and an adhesive applied to the base material,
A surface-protecting pressure-sensitive adhesive tape or sheet comprising ethylene oxide-modified dioctyl phthalate in a base material and / or a pressure-sensitive adhesive. 2. An adhesive tape or sheet comprising a plastic film as a base material and an adhesive applied to the base material,
A surface-protective pressure-sensitive adhesive tape or sheet, comprising 3 to 25% by weight of ethylene oxide-modified dioctyl phthalate in a base material and / or a pressure-sensitive adhesive.