JPH03243344A - Rustproofing sheet - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cracks in a bridged polyethylene layer by employing, as a support base material, synthetic resin nonwoven fabric and a laminate of plastic film, and applying and infiltrating a benzotriazole rust preventive agent and an adhesive agent onto the synthetic resin non-woven fabric side, and providing a coated layer of resin on the plastic film side. CONSTITUTION:As a nonwoven fabric, materials consisting of synthetic resin fiber such as polyester, nylon, polypropylene, polyethylene, or the like can be employed. For a support base material, a substance of being adhered to a plastic film such as polyethyleneterephthalate, polybutyleneterephthalate, and the like is used. The synthetic resin nonwoven fabric is applied and infiltrated, simultaneously or subsequently, with a benzotriazole rust preventing agent and an adhesive agent. Furthermore, the plastic surface is provided with a coated layer of resin. As the resin used herein, polyethyleneimine, isocyanate, and the like are given, and they can be employed in single or combined use. Among them, polyethyleneimine is preferable because of its excellent adhesiveness to crosslinkable polyethylene.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a rust-preventing sheet used as a protective material for copper and copper alloys, and more specifically to a rust-preventing sheet used as a protective material for copper and copper alloys. This invention relates to a rust-proof sheet useful for rust-proofing tapes and bare copper wires.

"Prior Art" Conventionally, rust-proof paper impregnated with a benzotriazole-based rust preventive agent has been widely used for rust prevention of copper and copper alloys. However, in the case of anticorrosion paper, since yam is used as the supporting base material, tear strength, tensile strength, etc. are not necessarily sufficient. For this reason, it may be unsuitable for some applications due to insufficient strength. For example, to use this as a rust preventive for grounding copper tape wrapped around the outside of electric wires and cables,
It is not strong enough to withstand use. For this reason, a rust preventive sheet has been proposed in which a synthetic resin nonwoven fabric with excellent tear strength and tensile strength or a nonwoven fabric laminated with a plastic film is used as a support base material, and this is impregnated with a benzotriazole rust preventive agent. ing.

Such anti-corrosion sheets are usually wrapped around copper wire, then melted and extruded with cross-linked polyethylene to provide protection and finish on electric wires and cables. This may cause damage, and accidents such as wire breakage may occur due to rusting or stress.

"Problems to be Solved by the Invention" In order to solve these problems, the present inventors have conducted extensive research and found that if the adhesion between the anti-rust sheet and the cross-linked polyethylene is poor, rainwater etc. may infiltrate into that area. It was discovered that cracks occur in the crosslinked polyethylene layer, which causes rust on the copper wire.

The inventors attempted to improve the adhesion by applying corona treatment or sandblasting to the plastic film surface, but corona treatment has the disadvantage that the treatment effect on the plastic surface deteriorates over time after treatment. However, the adhesion was weak during sandblasting, and a satisfactory result could not be obtained.

The present inventors have discovered that cracks in the crosslinked polyethylene layer can be prevented by providing a coating layer of a resin that improves adhesion to the crosslinked polyethylene on the plastic surface of the anticorrosion sheet.

"Means for Solving the Problems" The present invention uses a laminate of synthetic resin nonwoven fabric and plastic film as a support base material, and coats and impregnates the base resin nonwoven fabric side with a hensitriazole rust preventive agent and adhesive. , and a rust-preventing sheet characterized in that a resin coating layer is provided on the plastic film side.

"action" The anticorrosion sheet of the present invention has the structure as described above.

As the nonwoven fabric, one made of fibers of synthetic resins such as polyester, nylon, polypropylene, polyethylene, etc. can be used. Among them, polyester nonwoven fabrics have strength,
It is a preferable material because it has comprehensive properties such as heat resistance and insulation properties.

The supporting base material of the anticorrosive sheet of the present invention is made by laminating a plastic film of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyarylate, polyethylene, polypropylene, etc. on one side of the above-mentioned nonwoven fabric.

A rust-preventing sheet using a support base material having such a structure has excellent tear strength, tensile strength, etc., and is therefore suitable for use frequently in electric wires and cables, for example.

Examples of benzotriazole-based rust preventives used in the present invention include benzotriazole, methylhensitriazole, ethylbenzotriazole, aminobenzotriazole,
Examples include hydroxybenzotriazole. These benzotriazole-based rust preventives exhibit excellent rust preventive effects, particularly on copper and copper alloys.

Then, the above synthetic resin nonwoven fabric is coated and impregnated with a benzotriazole rust preventive agent and an adhesive simultaneously or sequentially. The appropriate amount of benzotriazole-based rust preventive is in the range of 0.01 to 1.0 g/m by dry weight when applying the adhesive at the same time, and when applying the adhesive afterwards. 0.02 to 5 g/r dry weight
A range of rr is preferred.

Incidentally, if the application amount is less than this range, the rust prevention effect will be poor, and if it is used in excess, the vaporized concentration of the rust preventive agent will become too high, creating a strong atmosphere of the rust preventive agent. This is because the copper alloy will be eroded, which will have a negative effect on the rust prevention effect.

Adhesives used in the present invention include natural adhesives such as starch and casein, cellulose adhesives such as carboxymethyl cellulose and hydroxyethyl cellulose, polyvinyl alcohol, ethylene/vinyl acetate copolymers,
Examples include thermoplastic synthetic resin adhesives such as ethylene/acrylic copolymers and butadiene/styrene copolymers.

Of course, these adhesives may be used in combination.

The present invention further provides a resin coating layer on the plastic film surface. Examples of the resin to be used include polyethyleneimine, isocyanate, urethane resin, polybutadiene resin, etc., and these can be used alone or in combination.

Among these, polyethyleneimine is preferably used because it has excellent adhesiveness with crosslinkable polyethylene.

The amount of resin applied is preferably in the range of 0.02 to 3.0 g/rd. If the coating amount is less than 0.02 g/m', the effect of improving adhesion cannot be obtained;
Even if it is set beyond the
On the contrary, there will be no economic advantage.

The coating method is not particularly limited, and the coating may be formed using a coating device such as an air knife coater, a blade coater, a bar coater curtain coater, a gravure coater, or a curtain coater.

Furthermore, it is preferable to subject the surface of the plastic film to corona treatment before applying the resin, since even better adhesion can be obtained.

"Example" The present invention will be described in more detail with reference to Examples below, but the present invention is of course not limited to these. In addition, "parts" and "%" in the examples indicate "parts by weight" and "% by weight", respectively, unless otherwise specified.

Example 1 Laminated sheet (Kijin ■, Purely 402
Corona discharge treatment (50W-min /n
0) at a dry weight of 1 g/(dry weight), then apply a paint containing hensitriazole and polyvinyl alcohol (PVA-117) in a ratio of 1:5 to the nonwoven fabric side at a rate of 0.5 g/dry weight of benzotriazole. /g to obtain a rust preventive sheet.

Example 2 Corona discharge treatment (50W-min/rr?) was applied to the polyester film side of the same laminated sheet as in Example 1, and 1 g/m of polyurethane emulsion (Hytran AP-20, manufactured by Dainippon Ink and Chemicals) was applied. ', and then apply a paint containing benzotriazole and polyvinyl alcohol (PVA117) in a ratio of 1:5 to the nonwoven fabric side at a dry weight of 0.5 g/benzotriazole/polyvinyl alcohol (PVA117).
A rust-preventing sheet was obtained by applying the anti-corrosion sheet.

Example 3 The polyester film side of the same laminated sheet as in Example 1 was subjected to corona discharge treatment (50 W min/m) and treated with butadiene emulsion (manufactured by Nippon Soda ■).

Titapond-180) was applied at a concentration of 1 g/%, and then 2 hensitriazole (dry weight) was applied to the nonwoven fabric side.
g/m', and then applied an adhesive containing styrene-butadiene copolymer and ethylene-acrylic copolymer sodium salt solution in a ratio of 1:1 (solid weight) to a dry weight of 15 g/m'. A rust-preventing sheet was obtained by applying the anti-corrosion sheet.

Comparative Example 1 Same as Example 1, but benzotriazole and polyvinyl alcohol (PVA117) were added at l:5 on the nonwoven fabric side of the laminated sheet.
The proportion of paint with hensitriazole is 0.5 by dry weight.
A rust-preventive sheet was obtained by applying the anti-corrosion sheet at a rate of 1.5 g/m.

Comparative Example 2 Same as Example 1, but hensitriazole and polyvinyl alcohol (PVA117) were added at 1:5 on the nonwoven fabric side of the laminated sheet.
The proportion of benzotriazole in the paint is 0.5 by dry weight.
g/m, and then corona discharge treatment (70W-min/m) on the polyester film side.
A rust-proof sheet was obtained.

Comparative Example 3 Benzotriazole and polyvinyl alcohol (PVA-117) were added to the nonwoven fabric side of the same laminated sheet as in Example 1;
The benzotriazole is 0.5% by dry weight of the paint.
It was coated at a weight of 5 g/rl, and then the polyester film side was subjected to sandblasting to obtain a rust-preventive sheet.

A rust prevention test and an adhesion test were conducted on the six types of rust prevention sheets thus obtained as described below.

"Rust prevention test" A copper plate (J I 51 (310
0,C00IP) and closed the three sides around it. When this was left for 7 days at 50°C and 97% RH and the state of rust and discoloration of the copper plate was observed, no rust or discoloration was observed. Met.

"Adhesion test" Polyethylene resin was extrusion laminated (30μ, 320°C) on the film side of the anti-rust sheet, and the peel strength (g/15m width) of the film and laminate layer was measured after being left for 1 day and after 30 days. Measurements were taken after standing, and the results are shown in Table 1.

Table 1 "Effects" As described above, the anti-rust sheet of the present invention has a large anti-rust effect, and also has extremely good adhesion to polyethylene resin over time, so even when used as electric wires and cables, It is durable enough.

Claims (1)

[Claims] A laminate of synthetic resin nonwoven fabric and plastic film was used as a supporting base material, and the synthetic resin nonwoven fabric side was coated and impregnated with a benzotriazole rust preventive agent and adhesive, and a resin coating layer was provided on the plastic film side. A rust-proof sheet characterized by: