JPS59197484A - Moistureproof mixture - Google Patents

Abstract

PURPOSE:To provide a moistureproof mixture suitable for sealing and moistureproofing of branching parts and joints of a communication cable, etc., prepared by adding a thickener and an antioxidant to polybutene and/or polybutadiene. CONSTITUTION:The mixture is prepared by blending 100pts.wt. polybutene with a molecular weight of 250-2,500 and/or polybutadiene with a molecular weight of 240-2,400, 2-50pts.wt. thickener (e.g., silica powder with a particle size of about 200 mesh), 0.01-2pts.wt. antioxidant (e.g. phenyl-alpha-naphthylamine) and, when necessary, 30pts.wt. or lower viscosity modifier (e.g. microcrystalline wax). The resultant mixture has a good moistureproofing effect against high-temperature water, causes no deterioration of insulating materials in contact with it and can be poured at normal temperature into areas to be moistureproofed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a moisture-proofing mixture used for sealing and moisture-proofing branch parts and connecting parts of cables such as communication cables.

Normally, at connection points such as communication cables, a moisture-proofing compound is injected into the connector-connected part for the purpose of moisture-proofing, and the exposed part is covered with a heat-shrinkable sheet to protect it. Conventional mixtures provided for such uses have been made into a jelly-like compound by using liquid paraffin as a base compound and adding a thickener to this compound.

However, the above-mentioned conventional mixtures have had the following problems.

■ If high-temperature water enters, the waterproofing effect will be significantly reduced and insulation failure may occur.

- It may lead to deterioration of the insulator in contact with the moisture-proofing mixture.

■ Other filling compounds used at connection points may be bath melted.

The problem shown in the above section is that conventional mixtures have poor adhesiveness and tend to separate between the mixture and the cable surface, etc.
This is thought to be due to easy immersion in warm water. Furthermore, the problems shown in items (1) and (2) are thought to be caused by the low molecular weight components in the liquid paraffin, which is the base compound, swelling the resin forming the insulator and the like.

The present invention has been made in view of the above circumstances, and is capable of exhibiting moisture-proof properties even in high-temperature water, without causing deterioration of other materials such as insulators in contact with it, and moreover, The purpose is to provide a moisture-proofing mixture that can be injected at room temperature.

The present invention will be explained in detail below.

The moisture-proof mixture according to the invention contains 2 to 5 thickeners per 100 parts of polybutene or/and polybutashev.
The mixture of 0 ki part and 0.01 to 2 parts of an antioxidant is referred to as 4'ji[.

The polybutene used here has a molecular weight of 250
Preferably, it is within the range of about 2,500 to 2,500. Polybutene with such a molecular weight has appropriate viscosity. In addition, polybutadiene has a molecular weight of 240 to 2
Anything within the range of 400 can be used. These polybutene and polybutadiene are used alone or as a mixture of both as a base compound.

The above-mentioned base compound has a suitable viscosity, and therefore, the mixture obtained using it also has adhesiveness, so that it can adhere to and cover connection points such as connectors. In addition, compared to the liquid paraffin used conventionally,
Since it has a large molecular weight, mixtures made using it do not cause deterioration of insulators or melting of other filling materials such as pads and powders.

In addition, the most suitable thickener is silica powder, but is not limited to inorganic thickeners such as clay, talc, zinc oxide, calcium bicarbonate, titanium white, zinc borate, and anti-hetamine trioxide. can be used. The particle size of this thickener is preferably about 200 mesh pass. The mixing ratio of the thickener to 100 parts by weight of the base compound is:
2 to 50 parts by weight is preferred; if it is less than 2 parts by weight, the resulting mixture will be too soft to be useful, while if it exceeds 501 parts by weight, it will be difficult to mix, and the mixture will have viscosity. I can't get things.

In addition, as antioxidants, general antioxidants for rubber,
Phenol-based materials such as BHT, and amine-based materials such as phenyl-α-su7thi and luamine are appropriately selected and used. The amount of antioxidant added is based on the base compound 1.
The amount is preferably 0.01 to 2 parts by weight per 0.00 parts by weight, and if it is less than 0.01 parts by weight, the desired antioxidant effect cannot be obtained sufficiently, and if it exceeds 2 parts by weight, If the amount added exceeds a sufficient amount, it becomes economically disadvantageous.

Refreshingly, the inventive mixture is usually coarse, but wax may be added if necessary to adjust the consistency.

The wax used is preferably microcrystalline wax, and the amount added is preferably 30 parts or less per 100 parts of the paste compound. If the amount exceeds 30 parts by weight, the fluidity of the resulting mixture deteriorates, making it difficult to inject it into the cable connection point at room temperature.

Therefore, the moisture-proofing mixture obtained by blending the above-mentioned pace combiner, thickener, and antioxidant with wax, which is made of polybutene and/or polybutadiene, is difficult to plasticize at room temperature due to the physical properties of the base compound. At the same time, it has adhesiveness and is sticky. Therefore, the cable connection portion can be filled at room temperature, and after filling, its tackiness provides excellent adhesion to the materials it comes into contact with. Furthermore, since the base compound does not contain resinous swelling components such as liquid paraffin, it does not deteriorate the insulators or other filling compounds that come into contact with it after filling, which improves the workability of filling. Moreover, high weather resistance and long life can be imparted to the connected portion after filling.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

〔Example〕

Using polybutene and polybutadiene as a base compound, 4g0A of the mixture of the example was prepared by mixing a thickener, an antioxidant, and a wax in the proportions shown in the table below.
I did PjH. Further, a comparative mixture was prepared by using liquid paraffin as a base compound and mixing a thickener, an antioxidant, and a wax with the proportions shown in the table below.

The polybutene has a molecular weight of 250 to 2500, and the polybutadiene has a molecular weight of 240 to 24.
00 was used. The particle size of silica is 200 mesh, and the particle size of magnesium carbonate is 200 mesh.

Phenol thread was used as the antioxidant, and microcrystalline wax was used as the wax.

The physical properties and performance tests shown in the table were performed on each of the above-mentioned mixtures. The results obtained are shown in the table.

(Notes on the table) ◆I JTS K 2561 2 JTS K 2524, 25℃-3J
c 2201 Medium 4 Shape into a conical shape with a bottom diameter of 15 cm and a height of 15 dragons, and process at a temperature of 70°C for 2 hours without causing any flow.

Medium 5: Measured after two weeks of treatment with warm water at 80°C.

116 Insulator (made of PG) was buried in the mixture and heated for 60 minutes.
I kept it at ℃ for 1 month and added it to the rear.

Example 7 An insulator (made of PE) was wrapped around its own diameter and embedded in the mixture, and the temperature was maintained at 80° C. After 4 months, the presence or absence of cracks was examined.

As shown in the table, does the mixture of the present invention swell the insulator? It was confirmed that the insulator was striped, and the results of the self-post-rolling heat test of the insulator confirmed that the insulator did not deteriorate. Unfortunately, the volume resistivity of the mixed material of the present invention is two to three orders of magnitude higher than that of conventional products using liquid paraffin, and it has physical properties suitable for moisture proofing cable connections and branching sections. I understand.

Applicant Fujikura Electric Wire Co., Ltd.

Claims (1)

[Claims] 2 to 50 parts by weight of thickener and 0.01 part by weight of antioxidant per 100 parts by weight of polybutene or/and polybutadiene.
- 2 parts by weight of a moisture-proof mixture.