JPH07100995A - Corrosion-proof tape - Google Patents

Abstract

PURPOSE:To obtain a corrosion-proof tape which has excellent adhesion force of a polyethylene base material wit a butyl rubber adhesive layer and in which a rewinding malfunction of a wound matter scarcely occurs and which can be efficiently manufactured without problem of manufacturing steps with processing of waste liquid, etc. CONSTITUTION:A corrosion-proof tape comprises a polyethylene single layer base material 1, and a butyl rubber adhesive layer 3 provided on the material 1 through a polyethylene intermediate layer 2 containing 10-60wt.% of styrene thermoplastic elastomer, olefin thermoplastic elastomer or/and butyl rubber. Thus, the tape in which, at the time of rewinding a wound matter even in a low temperature atmosphere, the adhesive layer is not peeled from the base material and which is formed of the polyethylene base material and the butyl rubber adhesive layer with excellent durability, executability, thin layer properties is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyethylene-based anticorrosion tape which has excellent adhesion between a base material and a butyl rubber-based adhesive layer and is resistant to unwinding defects.

[0002]

2. Description of the Related Art For the anticorrosion treatment of metal pipes such as pipelines for oil and gas, which are mainly used for underground burial construction, and pipes for regional air conditioning, a supporting base material is wrapped with an anticorrosion tape to cover it. The method is widely used, paying attention to advantages such as processing efficiency and workability.

Conventionally, as such an anticorrosion tape, a polyethylene-based tape comprising a polyethylene-based substrate and a butyl rubber-based adhesive layer provided thereon has been known. This polyethylene-based anticorrosion tape has advantages such as excellent durability and workability and can be advantageously used for large diameter pipes. From the viewpoint of handleability during coating work, etc. To be used for work.

However, the conventional polyethylene-based anticorrosion tape has a problem that the butyl rubber-based adhesive layer is peeled off from the polyethylene-based base material when the wound product is unwound, which makes it unusable. In particular, the peeling phenomenon frequently occurs in a low temperature atmosphere such as in a cold region.

In order to overcome the above problems, for example, a method of improving the adhesion by using a polyethylene base material which has been oxidized with an oxidizing agent such as chromic acid or ozone, or a flame-treated polyethylene base material. Various methods have been proposed, but in each case, the production efficiency is reduced due to the increase in the number of processes, and problems in the process such as waste liquid treatment of chemicals used and in the manufacturing stage such as safety and environmental hygiene are induced. However, the reality is that it is not a satisfactory solution.

[0006]

DISCLOSURE OF THE INVENTION The present invention has excellent adhesion between a polyethylene-based substrate and a butyl rubber-based pressure-sensitive adhesive layer, is less likely to cause unwinding defects of the wound material, and is a problem in the manufacturing stage such as waste liquid treatment. The challenge is to develop an anticorrosion tape that can be manufactured efficiently without the need for

[0007]

According to the present invention, a styrene type thermoplastic elastomer, an olefin type thermoplastic elastomer or / and a butyl rubber is added to a polyethylene type single layer base material.
The present invention provides an anticorrosion tape having a butyl rubber adhesive layer via a polyethylene intermediate layer containing 60 to 60% by weight.

[0008]

[Function] By interposing the polyethylene intermediate layer having the above structure between the polyethylene single layer base material and the butyl rubber pressure sensitive adhesive layer, good durability due to the combination of the polyethylene single layer base material and the butyl rubber pressure sensitive adhesive layer is achieved. The adhesion between the base material and the butyl rubber adhesive layer can be improved while maintaining the workability and thin layer property, and the butyl rubber adhesive can be used when rewinding the wound body even in a low temperature environment such as in a cold region. The anticorrosion tape can be obtained in which the adhesive layer is prevented from peeling off from the base material.

[0009]

EXAMPLE The anticorrosion tape of the present invention comprises a polyethylene single layer base material and a styrene thermoplastic elastomer, an olefin thermoplastic elastomer or / and a butyl rubber in an amount of 10 to 60.
It has a butyl rubber-based adhesive layer via a polyethylene-based intermediate layer that is contained by weight. An example thereof is shown in FIG. 1 is a polyethylene single layer base material, 2 is a polyethylene intermediate layer, and 3 is a butyl rubber adhesive layer.

As the polyethylene-based monolayer substrate, a film made of, for example, polyethylene, ethylene / vinyl acetate copolymer, ethylene / propylene copolymer, ethylene / ethyl acrylate copolymer, or a mixture thereof is generally used. The thickness of the base material is appropriately determined, but is generally 10 μm to 1 mm. It is not preferable to use a polyethylene-based single-layer base material having a composition conforming to that of a polyethylene-based intermediate layer containing an elastomer or a butyl rubber component, since blocking is likely to occur during unwinding of the wound product and unwinding failure may occur.

From the viewpoint of durability and the like, the polyethylene-based single layer base material is a cross-linked one. In addition, as the above-mentioned polyethylene, a medium- and low-pressure method linear system, a high-pressure method branched system,
Various types such as low density type and high density type can be used, and the type thereof is not particularly limited, and a mixture of two or more types can also be used.

The polyethylene-based intermediate layer is obtained by adding 10 to 60% by weight of a styrene-based thermoplastic elastomer, an olefin-based thermoplastic elastomer or / and a butyl rubber to the polyethylene-based component exemplified as the above-mentioned polyethylene-based single layer base material. Is formed by. When the content of the elastomer component or the butyl rubber component is less than 10% by weight, the effect of improving the adhesive force between the base material and the adhesive layer is poor, and when it exceeds 60% by weight, the physical properties of the base material are deteriorated or the moldability is poor. .

As the styrene thermoplastic elastomer, for example, SBS, SEBS, SIS, hydrogenated products thereof, and the like can be used appropriately. As the olefinic thermoplastic elastomer, an appropriate one such as ethylene / propylene rubber can be used, and Mirastomer (trade name, manufactured by Mitsui Petrochemical Co., Ltd.), Sumitomo TPE (trade name,
Sumitomo Chemical Co., Ltd.) and other commercially available products. The thickness of the polyethylene-based intermediate layer is appropriately determined, but is generally 10 μm.
It is m to 1 mm. The polyethylene-based intermediate layer is also preferably a cross-linked one from the viewpoint of durability and the like.

To form the butyl rubber-based adhesive layer, for example, butyl rubber may be appropriately added with additives such as tackifying resins such as rosin-based, terpene-based, and petroleum-based resins, fillers, softeners, and antiaging agents. It is possible to use an appropriate butyl rubber-based pressure-sensitive adhesive prepared by blending with. From the viewpoint of anticorrosion performance such as adhesion, butyl rubber is contained in an amount of 10 to 60% by weight. The thickness of the butyl rubber adhesive layer is 2 to
500 μm is typical, but not limited to this.

The anticorrosion tape of the present invention is formed by, for example, forming a polyethylene-based single layer base material and a polyethylene-based intermediate layer forming component into a film by a two-layer extrusion molding machine or the like. A base sheet having a two-layer structure in which a base material and a polyethylene-based intermediate layer are fused and integrated is formed, and a butyl rubber-based base sheet is formed on the exposed surface of the polyethylene-based intermediate layer by an adhesive coating method or an adhesive layer transfer method. It can be performed by a method of attaching an adhesive layer.

In the above-mentioned method, the mixture of the polyethylene component and the elastomer component and / or the butyl rubber component required for extrusion molding of the polyethylene intermediate layer is a dry blending method of pellets, mixing of block-shaped material or pearl-shaped material. It can be obtained by a method of pulverizing the kneaded product into pellets using a roll, a biaxial kneader, or the like. The butyl rubber-based pressure-sensitive adhesive layer for transfer can be obtained by a method of applying a pressure-sensitive adhesive by an appropriate method such as a calendar roll or a laminating method.

The obtained anticorrosion tape is processed in a roll form or the like with an appropriate width, for example, a width of about 50 to 300 mm, and is used for coating a metal pipe. The preferred method of use is to wind the tape 1 to 5 in the length direction when winding.
This is a method in which a tensile force is applied by stretching about 10%, and the stress causes the stress to adhere strongly to a metal pipe or the like.

Example 1 50 parts of low-density polyethylene (0.920 g / cm ³ , melt index 0.3) (weight part, hereinafter the same) and high-density polyethylene (0.954 g / cm ³ , melt index 0.45) ) 50 parts of the mixture for the base material and the mixture for the polyethylene-based intermediate layer are extruded in two layers by a two-layer T-die extruder to obtain a polyethylene-based intermediate layer having the same thickness as the polyethylene-based single-layer substrate having a thickness of 150 μm. A base sheet in which two layers are fused and integrated is formed, and a butyl rubber-based pressure-sensitive adhesive is applied onto the polyethylene-based intermediate layer by a calendar roll to have a thickness of 20.
An adhesive layer of 0 μm was provided, which was wound and cut into a width of 150 mm to obtain an anticorrosion tape.

In the above, the mixture for the polyethylene-based intermediate layer is a linear low-density polyethylene (0.920).
g / cm ³ , melt index 1.0) 50 parts and butyl rubber 50 parts were kneaded with an open roll, and the master batch-mixed product was crushed into pellets, and the pellets 20 and the linear low-density polyethylene Obtained by mixing 80 parts (butyl rubber content 10% by weight). The butyl rubber-based pressure-sensitive adhesive is composed of a mixture of 100 parts of butyl rubber, 80 parts of calcium carbonate, 40 parts of terpene-based tackifying resin, 10 parts of carbon black, 20 parts of polybutene, and 10 parts of process oil.

Example 2 An anticorrosion tape was obtained in the same manner as in Example 1 except that a pellet mixture of 90 parts of linear low-density polyethylene and 10 parts of SEBS was used as the mixture for the polyethylene-based intermediate layer.

Example 3 An anticorrosion tape was obtained in the same manner as in Example 1 except that a pellet mixture of 90 parts of linear low-density polyethylene and 10 parts of Mirastomer M4400N was used as the mixture for the polyethylene-based intermediate layer.

Example 4 An anticorrosion tape was obtained in the same manner as in Example 1 except that a pellet mixture of 80 parts of linear low-density polyethylene and 20 parts of SEBS was used as the mixture for the polyethylene-based intermediate layer.

Example 5 An anticorrosion tape was obtained in the same manner as in Example 1 except that a pellet mixture of 60 parts of linear low-density polyethylene and 40 parts of SEBS was used as the mixture for the polyethylene-based intermediate layer.

Example 6 An anticorrosion tape was obtained in the same manner as in Example 1, except that a pellet mixture of 50 parts of linear low-density polyethylene and 50 parts of SEBS was used as the mixture for the polyethylene-based intermediate layer.

Example 7 An anticorrosion tape was obtained in the same manner as in Example 1, except that a pellet mixture of 40 parts of linear low-density polyethylene and 60 parts of SEBS was used as the mixture for the polyethylene-based intermediate layer.

Comparative Example An anticorrosion tape was obtained in the same manner as in Example 1 except that the polyethylene-based intermediate layer was formed of linear low-density polyethylene, and the intermediate layer surface was corona-treated to provide a butyl rubber-based adhesive layer.

Evaluation Test The anticorrosion tapes obtained in Examples and Comparative Examples were subjected to the following tests.

Peeling force The pressure-sensitive adhesive layers of the anticorrosion tape were press-bonded to each other, and the T-shaped layers were peeled off to measure the adhesive force between the substrate and the pressure-sensitive adhesive layer.

Low temperature rewinding property The anticorrosion tape was stabilized at -20 ° C for about 1 day, and then the wound tape was rewound at that temperature and evaluated according to the following criteria. Good: When it can be rewound smoothly without any abnormality. Bad: When the adhesive layer was peeled off from the base material and rewinding was impossible.

The above results are shown in Table 1.

[Table 1]

From Table 1, the anticorrosion tape according to the present invention has excellent adhesion between the polyethylene-based single-layer base material and the butyl rubber-based adhesive layer, and can smoothly rewind the wound material in a normal state even at low temperature. I understand.

[0032]

EFFECTS OF THE INVENTION According to the present invention, the polyethylene-based substrate has excellent adhesion between the substrate and the adhesive layer, and the adhesive layer does not peel off from the substrate when the wound body is unwound even in a low temperature atmosphere. It is possible to obtain an anticorrosion tape which is composed of a butyl rubber-based adhesive layer and is excellent in durability, workability, thinness, etc., and is excellent in production efficiency without problems during production such as waste liquid treatment.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

[Explanation of symbols]

 1: Polyethylene-based single layer base material 2: Polyethylene-based intermediate layer 3: Butyl rubber-based adhesive layer

Claims (2)

[Claims] 1. A polyethylene-based single layer base material having a butyl rubber-based adhesive layer via a polyethylene-based intermediate layer containing 10 to 60% by weight of styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer and / or butyl rubber. Anticorrosion tape characterized by. 2. The anticorrosion tape according to claim 1, wherein the polyethylene single-layer substrate and / or the polyethylene intermediate layer is crosslinked.