JPS6240189B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new laminate tape with a lead layer. Metal-corrosive gases such as hydrogen sulfide and ammonia, as well as moisture, can penetrate the protective outer layer of polyvinyl chloride of various electrical devices, such as coaxial cables, and corrode the electromagnetic shielding layer. It has been proposed to apply a longitudinal layer of metal laminate tape between the shielding layer and the shielding layer for the purpose of gas shielding. In that case, it is desirable that the outside of the vertically laminated metal laminate tape vertically laminated layer be well adhered to the PVC protective outer layer;
It is desirable that the inside of the shielding layer be electrically connected to the electromagnetic shielding layer. The present invention proposes a conventional laminate tape that can satisfy the above requirements, in which a layer of conductive polyvinyl chloride is provided on one side of the lead layer, and a layer of conductive polyvinyl chloride is provided on the other side of the lead layer. , a polyvinyl chloride layer and an adhesive layer containing a vinyl chloride-vinyl acetate copolymer as a main component thereon. FIG. 1 is a cross-sectional view of the laminated tape of the present invention placed vertically on a long object such as a coaxial cable for measurement, and includes an enlarged view of the overlapping portion of the laminated tape placed vertically. In FIG. 1, a laminate tape 3 of the present invention is vertically laid on a long body 2 having a metallic layer, for example, an electromagnetic shielding layer 1 on the outside, and an outer layer 4 of a polyvinyl chloride protective layer is placed on top of the laminate tape 3 of the present invention.
is applied. The laminate tape 3 is made of a conductive polyvinyl chloride layer 31, a lead layer 32, a heat-resistant organic polymer layer 33, a polyvinyl chloride layer 34,
and an adhesive layer 35. The lead layer 32 is in electrical contact with the layer 1 via the conductive polyvinyl chloride layer 31, and the laminate tape 3 is adhered to the polyvinyl chloride protective outer layer 4 by the adhesive layer 35. Further, in the longitudinally overlapping portion of the laminate tape 3, the polyvinyl chloride layer 34 and the conductive polyvinyl chloride layer 31 are well bonded to each other by the adhesive layer 35, so that the airtightness of the overlapping portion is maintained well. ing. Without the conductive polyvinyl chloride 31 on one side of the lead layer 32, direct contact between the lead layer 32 and layer 1 would ensure electrical contact, but the mechanical brittleness and wrinkles of the thin lead layer 32 would result. Because of this tendency to occur, there is a problem in that when a lengthwise length of such a lead laminate tape is bent, the tape easily buckles. On the other hand, if the layer 31 is provided as in the present invention, the lead layer 3
2 is reinforced from both sides, improving buckling resistance. The adhesive layer 35 of the laminate tape of the present invention has good adhesion not only to the elongated polyvinyl chloride protective outer layer 4 which is usually continuously molded by extrusion, but also to the conductive polyvinyl chloride layer 31. It is required to have the following. The constituent material of the conductive polyvinyl chloride layer 31 is generally commercially available polyvinyl chloride mixed with a conductivity imparting agent such as carbon black or metal powder, and has a volume resistivity of 10 ¹ to 10 ⁶ Ω・cm at room temperature. It is of a certain degree. From the viewpoint of extrusion processability and mechanical properties required as a protective outer layer material, it is particularly preferable to use a conductive carbon black such as acetylene black or ketzen black as a conductivity imparting agent, and 100 parts by weight of polyvinyl chloride (parts by weight, the same applies hereinafter). 10-40 per
It is preferable to have the above-mentioned conductivity when mixed to some extent. In that case, a plasticizer known as a plasticizer for polyvinyl chloride, such as dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, etc., and other usual additives may be blended in normal amounts. . In the course of completing the present invention, adhesion of the above-mentioned conductive polyvinyl chloride layer was particularly difficult, but the use of the following adhesive used in the present invention makes such adhesion possible. In the present invention, the constituent material of the adhesive 35 is one whose main component is a vinyl chloride-vinyl acetate copolymer. As the copolymer,
A copolymer of two monomers, vinyl chloride and vinyl acetate, in a wide range of ratios, and a small amount (preferably 10% by weight or less) of an unsaturated carboxylic acid such as maleic acid or acrylic acid as a third monomer. Terpolymer copolymers containing these are used. The degree of polymerization is 100
~1000 is appropriate. Preferred copolymers include a vinyl chloride component of 70 to 95% by weight, a vinyl acetate component of 5 to 30% by weight, and a degree of polymerization of 1.00 to 1.00.
900, especially 300-600 vinyl chloride-vinyl acetate binary copolymer, vinyl chloride component 79-92% by weight, vinyl acetate component 7-20% by weight, maleic acid component 0.1-
It is a vinyl chloride-vinyl acetate-maleic acid terpolymer with a polymerization degree of 100-900 and a weight of 10%. The vinyl chloride-vinyl acetate copolymer may be used alone, or may be mixed with other additives, such as adhesion improvers, antioxidants, pigments, etc., as long as it does not adversely affect the adhesion. I can't help it. In particular, natural or synthetic raw rubbers and adhesive polymers are used as adhesion improvers at 5% per 100 parts of the above copolymer.
It is desirable to use a mixture of ~30 parts. . Preferred examples of raw rubbers that exhibit such an effect include one or more selected from the group consisting of acrylonitrile rubber, styrene oligomer, thermoplastic polyester, and epoxy resin. The lead layer 32 contains pure lead as well as a small amount, especially 10% by weight.
It may be composed of a lead alloy containing the following alloy components. Since the lead layer 32 has corrosion resistance against various gases and moisture, it exhibits a gas shielding effect during long-term use. As the constituent material of the polyvinyl chloride layer 34, commercially available polyvinyl chloride may be used, and if necessary, it may be plasticized with the above-mentioned plasticizer, or it may be blended with other usual compounding agents. Good too. Although the heat-resistant organic polymer layer 32 is not necessarily required in the present invention, it is desirable to provide it in order to further facilitate the use of the tape of the present invention for the following reasons. That is, layer 31, layer 3 of the tape of the present invention
4 are all based on polyvinyl chloride, and layer 35 generally has a lower softening temperature than polyvinyl chloride. Therefore, when the tape of the present invention is used at a high temperature higher than the softening temperature of polyvinyl chloride, all of the tension during vertical stretching is applied only to the lead layer, which generally does not have high mechanical strength, and the tape may break. There's a problem. Alternatively, in order to avoid cutting the tape, it is necessary to lower the tape tension during longitudinal alignment, making it difficult to perform good longitudinal alignment. On the other hand, if there is a layer 33 of a heat-resistant organic polymer that has mechanical strength even when exposed to high temperatures during longitudinal alignment, the tape breaking strength will be increased by that layer, so it will be possible to maintain good longitudinal alignment with even higher tension. It is possible to follow along. The above-mentioned heat-resistant organic polymers include those having a softening point and melting point higher than that of polyvinyl chloride, such as polyethylene terephthalate, polyamide, polyimide,
Polyamideimide, polyesterimide, polysulfone, polyethersulfone, etc. are used. The appropriate thickness of each of layers 31 to 35 is about 20 to 100 μm. Further, the lead layer 32 and the heat-resistant organic polymer layer 33 and the layer 33 and the polyvinyl chloride layer 34 may be bonded together using, for example, an epoxy adhesive, a polyurethane adhesive, a polyester adhesive, or the like. The polyvinyl chloride layer 34 and the adhesive layer 35 can be bonded together by the adhesive force of the adhesive layer 35 itself. The lead layer 32 and the conductive polyvinyl chloride layer 31 are made of a conductive adhesive, such as the above-mentioned epoxy adhesive, polyutane adhesive, or polyester adhesive, mixed with a conductivity imparting agent such as metal powder. , or the adhesive layer 3
The adhesive can be bonded using a material in which conductive carbon black is mixed with the material used as the constituent material of No. 5. In addition to the uses described above, the laminate tape of the present invention can be applied to various electrical devices for the purpose of preventing fluid permeation, and can exhibit remarkable effects. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 A conductive film made of 100 parts of polyvinyl chloride, 50 parts of acetylene black, and 60 parts of a plasticizer (dioctyl phthalate) formed on one side of a 50 μm thick pure lead sheet using a calendar roll to a thickness of 100 μm. A film made of polyvinyl chloride (volume resistivity 2.5×10 ⁴ Ω·cm) was attached. In this case, 75% by weight vinyl chloride component and 25% vinyl acetate are used as adhesives.
Adhesion was performed using a conductive adhesive containing 100 parts by weight of vinyl chloride-vinyl acetate copolymer and 15 parts of Kettien Black. On the other hand, on one side where the lead layer remains,
A 50 μm thick sheet of soft polyvinyl chloride made of 100 parts of polyvinyl chloride and 40 parts of dibutyl phthalate was adhered onto the μm thick polyethylene phthalate sheet using a two-component polyurethane adhesive. Furthermore, vinyl chloride component
A solution of vinyl chloride-vinyl acetate copolymer containing 75% by weight and 25% by weight of vinyl acetate dissolved in a mixed solvent of methyl ethyl ketone/toluene was applied and dried.
A layer of the copolymer having a thickness of 20 μm was formed. Example 2 25 μm thick lead alloy sheet (93% lead, 5% tin,
(composed of 2% antimony), 100 parts by weight of polyvinyl chloride and 50 parts by weight of acetylene black,
A 100 μm thick conductive polyvinyl chloride film consisting of 60 parts of dioctyl phthalate (volume resistivity
2.5×10 ⁴ Ω・cm), vinyl chloride-vinyl acetate-maleic acid copolymer 100 consisting of 81% by weight vinyl chloride, 17% by weight vinyl acetate, and 2% by weight maleic acid.
The parts were bonded together using a conductive adhesive containing 35 parts of KETSUCHEN BLACK. On the other hand, the remaining one side of the lead alloy sheet has a thickness of 100 μm.
A 50 μm thick hard polyvinyl chloride film was adhered onto the polysulfone film using a two-component polyester adhesive. Furthermore, the above vinyl chloride - vinyl acetate -
A solution of a maleic acid copolymer dissolved in a mixed solvent of methyl ethyl ketone/toluene was applied and dried to form a layer of the copolymer with a thickness of 20 μm. Example 3 Instead of the vinyl chloride-vinyl acetate copolymer used in Example 1, a vinyl chloride-vinyl acetate copolymer consisting of 90% vinyl chloride and 10% vinyl acetate had a molecular weight of 380 and an epoxy equivalent of 190 per 100 parts by weight. A laminate tape was prepared in exactly the same manner as in Example 1, except that a compound containing 30 parts by weight of epoxy resin (Epiyute 828) was used. Example 4 In place of the vinyl chloride-vinyl acetate-maleic acid copolymer used in Example 2, vinyl chloride-vinyl acetate-maleic consisting of 86% by weight vinyl chloride, 13% by weight vinyl acetate, and 1% by weight maleic acid was used. A laminate tape was prepared in the same manner as in Example 2, except that a compound containing 20 parts by weight of nitrile rubber with a viscosity of 100,000 centipoise at 30°C and a bonded nitrile content of 40% per 100 parts by weight of the acid copolymer was used. did. Comparative Example 1 A laminate tape was prepared in exactly the same manner as in Example 1 except that a thermoplastic polyester resin (Vylon 300) having a molecular weight of 20,000 was used in place of the vinyl chloride-vinyl acetate copolymer used in Example 1. Comparative Example 2 A laminate tape was prepared in exactly the same manner as in Example 2, except that a polyurethane resin (paraprene p22SRNAT) with a softening temperature of 105°C was used in place of the vinyl chloride-vinyl acetate-maleic acid copolymer used in Example 2. It was created. The laminate tapes (width 100 mm) of Examples 1 to 4 and Comparative Examples 1 to 2 were each placed vertically on an aluminum pipe with an outer diameter of 30 mm, and the overlapping parts of the laminate tapes were bonded at high temperature using hot air and pressure. Then, a soft vinyl chloride sheath was extruded and coated around the outer periphery of the laminate tape. After the soft vinyl chloride sheath was cooled, the internal aluminum pipe was pulled out to obtain a cylindrical integrally molded product of the laminate tape and the soft vinyl chloride sheath. A length of 3 m was sampled from the obtained cylindrical molding, metal pipes with valves were attached to both ends so that the gas inside the cylindrical molding could be collected, and the attached parts were hardened with epoxy resin. The cylindrical molded product obtained in this manner was bent into a U-shape, and the central 2 m portion was immersed in hydrogen sulfide gas-saturated water at 70°C to remove hydrogen sulfide gas and moisture that entered through the overlapped portion of the laminate tape. Measured regularly. In this case, to measure the amount of hydrogen sulfide gas that has entered, a spring balance with copper metal powder suspended is placed in a closed space that is continuous with the inside of the cylindrical molded product, and the reaction with the hydrogen sulfide gas that has entered is measured. The rate at which the weight of the copper powder increased was measured. In addition, moisture content was measured by using phosphorus pentoxide powder instead of copper powder, and measuring the rate at which the weight of phosphorus pentoxide increased due to reaction with invading moisture. Table 1 shows the results of comparing the gas barrier properties of the cylindrical molded products of the laminate tapes prepared in Examples 1 to 4 and Comparative Examples 1 and 2 through the above measurements.

[Table] From the above results, it can be seen that the laminate tape according to the example has stable adhesion at the overlapping portion and adhesion to the polyvinyl chloride sheath, and has extremely excellent gas barrier performance.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of an embodiment of the laminate tape of the present invention and an example of its use.
1, a lead layer 32, a polyvinyl chloride layer 34, and an adhesive layer 35.

Claims (1)

[Claims] 1. A conductive polyvinyl chloride layer is provided on one side of the lead layer, and a polyvinyl chloride layer and a vinyl chloride-vinyl acetate copolymer are provided on the other side of the lead layer. A laminated tape with an adhesive layer mainly composed of. 2. The laminate tape according to claim 1, which has a heat-resistant organic polymer layer between the lead layer and the polyvinyl chloride layer. 3 The vinyl chloride-vinyl acetate copolymer has a vinyl chloride component of 70 to 95% by weight and a vinyl acetate component of 5 to 30% by weight.
The laminate tape according to claim 1 or 2, which is a vinyl chloride-vinyl acetate binary copolymer in a weight percent. 4 The vinyl chloride-vinyl acetate copolymer has a vinyl chloride component of 79 to 92% by weight and a vinyl acetate component of 7 to 20% by weight.
The laminate tape according to claim 1 or 2, which is a vinyl chloride-vinyl acetate-maleic acid terpolymer with a maleic component of 0.1 to 10% by weight. 5. A patent in which the adhesive layer contains 5 to 30 parts by weight of at least one member selected from the group consisting of acrylonitrile rubber, epoxy resin, and thermoplastic polyester per 100 parts by weight of vinyl chloride-vinyl acetate copolymer. A laminate tape according to claims 1 to 4.