JPS6049232B2 - self-fusing tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-bonding tape mainly used for connection and terminal treatment of high-voltage cables, and more specifically relates to heat resistance, electrical properties, crack resistance, and self-bonding properties. The present invention also provides a self-fusing tape with excellent tape winding workability.

Various types of self-bonding tapes containing ethylene-propylene copolymers or ethylene-propylene terpolymers as main components have been known so far, but at present no satisfactory one has yet been developed. For example, a composition tape made by mixing the above main ingredients with a high molecular weight rubber and a large amount of organic peroxide is heat-treated to thermally decompose the high molecular weight rubber and develop self-fusion properties. Tape is suggested.

However, this lever tape has the disadvantage that when it is exposed to high temperature conditions such as in the summer after being wrapped around an object, it easily peels off because its self-fusing strength at high temperatures decreases. We also proposed a self-fusing tape consisting of a tape supported by a molded cross-linked tape made of the above main ingredients mixed with a softening substance and a large amount of organic peroxide, and a self-fusing layer made of a polyolefin elastomer and a softening substance. has been done.

However, this tape support has a high crosslinking density and the binding force is too strong, so when it is wrapped around an end with a high elongation rate, it deforms the cable, and stress cracks occur9 and the insulation function is lost. This self-adhesive layer also has the disadvantage that sufficient self-adhesiveness is difficult to obtain because the self-adhesive layer lacks adhesiveness. The present invention relates to a novel self-fusing tape that solves the drawbacks of the prior art, and its gist is that ethylene-propylene copolymer (EPM) and/or ethylene-propylene terpolymer ( EPDM)70~9
A mixture containing as essential components a heel volume, 10 to 3 volume parts of a non-crosslinking softening substance, and 0.1 to 0 organic peroxide, and a heel volume,
O, l5 with elongation of 900%5 or more and modulus of 300%
It consists of a tape support that has been molded and crosslinked to have physical properties of 9/TfUfL or less, and a self-fusing layer that is closely attached to the surface of the support. According to the present invention, even if the self-bonding tape is stretched by more than 500% (six times its original length) and wrapped around a cable, not only will the cable not be deformed, stress cracks will not occur, and the temperature will be relatively low. It is characterized by the fact that the tapes are sufficiently fused to each other even when wrapped, and the layers do not peel off even if exposed to a high temperature atmosphere after wrapping, so there is no need for high temperature skill to wrap the tape. It can be used for winding work.

The EPM used in the present invention is a copolymer of ethylene nipropylene, 60:40 to 40:60 (mole ratio), and EPDM is, for example, a copolymer of ethylene nipropylene, nonconjugated diene, 50 to 90:10 to 50:10. Below (molar ratio)
It is a copolymer consisting of EPM and/or E
A commercially available PDM can be used.

As the non-crosslinkable softening substance used in the present invention, rubbers that are not crosslinked with organic peroxides, such as pulti rubber, polyisobutylene, and polybutene, are used. Further, as the organic peroxide, dicumyl peroxide, ditertiary butyl peroxide, etc. having a purity of 90% or more are used.

Therefore, the blending ratio of EPM and/or EPDM, non-crosslinkable softening substance, and organic peroxide is
Non-crosslinkable softening substance 1 to 90 parts by weight of PDM7O
0 to 30 parts by weight and 0.1 to 0.0 parts by weight of organic peroxide. It is important to use the non-crosslinking softening substance within the heel area.
If it is less than 3 parts by weight (therefore, 90 parts by weight or more of EPM and/or EPDM), the tape support will have poor flexibility, and if it is more than 30 parts by weight (therefore, 7 parts by weight or less of EPM and/or EPDM), it will not have the desired heat resistance. This is undesirable because it does not provide good properties and mechanical strength.

Furthermore, if the organic peroxide substance is less than 0.1 part by weight, crosslinking will be insufficient and the desired heat resistance and mechanical strength will not be obtained.
．． Above the weight capacity, the crosslinking density becomes too high even if crosslinked under normal manufacturing conditions, resulting in an elongation of over 900% and a modulus of 300% of 0.15k9/Tr! 1t or less (a). 06k
g/d or higher) cannot be obtained, the cable is deformed after winding, and a stress rack 41 is inserted, which is undesirable. By adjusting the blending ratio in this way, we achieved an elongation of over 900% and a modulus of 300% of 0.1.
One or both sides of the support for self-fusing tape, which has physical properties of 5 kg/TrOi or less, has a self-fusing property having a composition that does not substantially impede the physical properties of the support regardless of the thickness of the coating film formed. By limiting the thickness of the formed coating, the material or substantially unhindered self-fusing material is formed to a thickness of approximately 0.001 to 0.1 m:Fn. As the self-fusing substance, a substance mainly composed of butyl rubber or the like can be used, but a substance containing a polyolefin elastomer, a softening substance, and a tackifying agent having a melting point of 80 to 130°C in a specific ratio, θ is the above-mentioned one. It is preferable because it has excellent adhesion to the tape support and exhibits behavior similar to that of the support, so even if there is variation in the thickness of the formed film, the physical properties of the tape support will not be adversely affected.
This preferred self-fusing material is EPM, 7EPDM1
For 100 parts by weight of a polyolefin elastomer such as an isobutylene-isoprene copolymer, 10 to 3 parts by weight of a softening substance such as oil, polybutene, or polyisobutylene, a phenolic resin having a melting point of 80 to 130°C, or a coumaron-indene type. This is a composition in which 10 to 10 parts of one or more tackifiers selected from resins such as resins and terpene resins are added and mixed.

It should be noted that appropriate amounts of known compounding agents such as fillers, pigments, reinforcing agents, anti-aging agents, etc. can be added to the self-fusible tape support and self-fusible substance, if necessary.

The self-fusing tape of the present invention is made of EPM and/or EPDM.
, a non-crosslinkable softening substance, and a compounding agent added as necessary using a known mixer such as a mixing roll or Panbury mixer, and then cooling the mixture to near room temperature and adding a predetermined amount of organic filtrate. Oxide is added and mixed, molded to a predetermined thickness, and cross-linked by heating at a predetermined temperature (approx. A support for a fusible tape is obtained.

Then, a self-fusing substance liquid (solid content 1 to 30%) dissolved in, for example, a naphthenic hydrocarbon or aromatic hydrocarbon solvent is applied to one or both sides of the support surface, dried, and rolled up together with a release material. A self-fusing tape can be obtained by cutting the tape into a predetermined width.

Examples of the present invention will be shown below. The middle part of the table shows the parts by weight.
Example 1 A support for a self-fusing tape is obtained by molding and crosslinking the compositions in Table 1 by the means detailed in the text.

For comparison, self-bonding tapes were similarly prepared using the compositions of Comparative Examples in Table 1. The physical properties in Table 1 are measured using a No. 2 dumbbell piece at 20°C in accordance with JIS K63Ol.

To test the crack resistance, sample bodies were prepared by stretching the tape to 2 times, 4 times, and 6 times the original length and wrapping it half-wrap around a 20 mm round bar. 130
The sample was stored at °C for 3 hours, and the occurrence of stress cracks was visually determined. Example 2 Sample No. of Example 1. l
A self-fusing substance shown in Table 2 is coated on one side of the tape support to obtain a self-fusing tape.

How to determine end peeling under high temperature: Stretch the tape to three times its original length and wrap it half-wrap around the round rod of 2 (G) [Phase] and store it in an atmosphere of 100°C for 1 hour. and visually determine the state of peeling of the terminal.

As is clear from Example 1, the self-fusing tape of the present invention uses a self-fusing tape support having a specific composition and specific physical properties.
It is notable that no stress cracks occur even when the product is wrapped at twice as high a degree of elongation, and stress cracks do not occur due to variations in the degree of elongation, so a high degree of skill is not required for the wrapping work. .

Claims (1)

[Scope of Claims] 1. 70 to 90 parts by weight of ethylene-propylene copolymer and/or ethylene-propylene terpolymer, 10 to 30 parts by weight of non-crosslinkable softening substance, and 0 parts by weight of organic peroxide substance.
．． 90% of the mixture containing 1 to 0.8 parts by weight as an essential component.
0.15kg/with over 0% elongation and 300% modulus
A self-fusing tape comprising a tape support molded and crosslinked to have physical properties of mm^2 or less, and a self-fusing layer closely attached to the surface of the support. 2. The self-bonding layer contains 10 to 30 parts by weight of a softening substance based on 100 parts by weight of the polyolefin elastomer, 10 to 100 parts by weight.
2. The self-fusing tape according to claim 1, which is a self-fusing material comprising a tackifying agent having a melting point of 80 to 130[deg.] C. in parts by weight.