JPS6319712A - Loading material for cable - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a cable filling material that is a component of communication cables, and more specifically, it is extremely useful as a cable filling material used in water running prevention type cables. Concerning new materials with superior performance.

(Prior Art) The F1a structure of a conventional communication cable is as follows in -C. As shown in the cross-sectional view of the communication cable in Fig. 1, there is a tension member as the core l in the middle tone part, and a plurality of communication conductors 2 are arranged around it at equal intervals. A filling material 3 is present in the gap between the conductive wires and enveloping the whole, the outer periphery of the filling material 3 is covered with a tape 4 to form a circular cross section, and the whole is further wrapped with an outer skin layer 5. Conventionally, as the filling material for No. 3,
Threads or split yarns made of hemp or polypropylene, crepe paper or polyvinyl chloride integrated with a sheath, etc., have been used. Now, in recent years, communication cables are increasingly being used by being buried underground, but if a crack occurs for some reason in the cable sheath (the outermost layer of the cable) while it is being buried underground and being used, it can cause damage. There is a problem in that water from the crank enters the inside of the cable along with the soil, adversely affecting communication.

Therefore, there is a need to prevent water from entering the inside of cables, that is, to prevent water running, and in recent years, cables that prevent water running have been developed for communication cables such as underground cables and submarine cables. Ta. Conventionally, petrolactam-based or polybutene-based jelly has been used as the internal filling material for these water-travel prevention cables.
It has many problems. In other words, workability is poor when connecting cables together, there is a limit to the jelly filling speed during cable manufacturing, resulting in poor cable productivity, and in the case of optical fiber cables, microbending at extremely low temperatures can cause damage. There are problems such as: In order to solve these problems, attempts have recently been made to fill the inside of cables with water-absorbing polymers or water-absorbing fibers such as polyacrylic acid-based or carboxymethyl cellulose-based cables to prevent water running. Among these, in the case of using a water-absorbing powder polymer, there are disadvantages as described in Japanese Patent Application No. 60-234632 filed by the applicant of the present invention.
In other words, the polymer powder tends to fall off when connecting the cable, resulting in poor connection workability, and the polymer powder may move inside the cable due to tilting or vibration of the cable. The disadvantage is that it is difficult to make it exist. Therefore, the use of water-absorbing fibers has recently attracted attention. Under such circumstances, the present inventors invented a cable filling material disclosed in the above-mentioned Japanese Patent Application No. 60-234632 as an extremely excellent filling material.

Subsequently, the present inventors conducted further studies and found that carboxymethylcellulose-based water-absorbing fibers (hereinafter abbreviated as CMC fibers) have extremely excellent water running prevention properties; We have discovered that when soil water is in contact with soil water for a long period of time, the anti-hydrotropic effect is gradually absorbed.

This means that if a crack occurs in the sheath of a cable buried in the ground for some reason, soil water around the cable will gradually permeate into the inside of the cable and have an adverse effect. This is thought to be due to the fact that the CMC fibers are corroded and destroyed by soil bacteria and the like present in the soil water.

Therefore, we extensively investigated chemicals known as fiber preservatives and CMC paste preservatives in order to aim for antiseptic effects on soil water. Examples include aromatic halogen compounds, organometallic compounds, salicylic acid, sorbic acid, triazine compounds, and organic arsenic compounds and thiazoline compounds known as antibacterial agents for plastics. As a result, we found organometallic compounds containing tin, copper, zinc, etc., such as tributyltin oxide, naphthenic acid, zinc octylate, etc., as having antiseptic effects on soil water, and these were attached to CMC fibers. A new problem arose: the water absorption performance of the fibers was impaired.

The present inventors further investigated a preservative that not only has a preservative effect on soil water but also does not impair the extremely excellent water absorption performance inherent to CMC fibers, and finally arrived at the present invention.

(Objective of the Invention) The object of the present invention is to fully demonstrate the water absorption performance of CMC fibers, and to have excellent antiseptic properties against soil water;
For a long time. Run 28. □Providing an excellent filler material for 7 and 7 containers.

(Means for Solving the Problems) The gist of the present invention for achieving the above object of the present invention is as follows:
The present invention provides a filling material for cables made of CMC fibers containing at least 0.1% by weight of at least one compound selected from the group of quaternary ammonium salt compounds, acetamide compounds, and guanidine compounds.

The filling material used in the communication cable of the present invention consists of the following two points.

The first point is to use CMC fibers.

That is, when the water-absorbing fiber is used as a filling material for communication cables, there are the following two characteristics. The first feature is that it is entirely fibrous, and since the entire fibrous material has water absorption properties, it can solve the drawbacks of conventional water-absorbing polymer powders. That is, it is possible to eliminate the drawbacks such as the polymer powder falling off when connecting the cable and the polymer powder moving inside the cable. The second feature is that it can exhibit extremely excellent water running prevention properties. Polyacrylic acid-based and carboxymethylcellulose-based fibers are known as water-absorbing fibers. Polyacrylic acid-based water-absorbing fibers exhibit anti-water running properties against water that does not contain seawater, but they do not tolerate seawater. On the other hand, the saturated water absorption capacity decreases extremely and the water running prevention property disappears. On the other hand, CMC fibers exhibit extremely excellent anti-water running properties even against seawater, and exhibit excellent anti-water running properties even when buried underground anywhere, including along the coast.

The second point of the present invention is that the CMC fiber contains at least 0.1% by weight, preferably 1% or more of at least one compound selected from the group of quaternary ammonium salt compounds, acetamide compounds, and guanidine compounds. It's because I was forced to do so. This allows the following two features to be exhibited. The first feature is that even if the fibers come into contact with soil water for a long period of time, the fibers do not corrode and maintain excellent water running prevention properties for a long period of time. The effect is exhibited when the content of the above composition is about 0.1%. Especially when safety is desired from the viewpoint of long-term antiseptic effect, 1% or more is preferable. The second feature is that even if the above-mentioned compound is contained, the CMC fiber exhibits extremely excellent anti-water running properties without impairing the excellent water absorption performance that it has traditionally possessed.

A dialkyldimethylammonium compound to be converted into a quaternary ammonium salt used in the present invention, Rt, Rt
are the same or different alkyl groups or alkenyl groups having 8 to 18 carbon atoms, and X is a halogen atom.

For example, dioctyldimethylammonium chloride, didecyldimethylammonium chloride, didodecyldimethylammonium chloride, dioctadecyldimethylammonium chloride, dioctadecyldimethylammonium chloride, dioctadecyldimethylammonium chloride, octyldecyldimethylammonium chloride, dioleyldimethylammonium chloride and the above. These include compounds that use bromide instead of chloride.

Preferred quaternary ammonium salt compounds include RIR2
are the same and X is chloride.

The acetamide compound used in the present invention is a compound represented by the general formula X-CHz C-NHz,
X is a halogen atom. For example, 2-chloroacetamide, 2-bromoacetamide, etc., preferably 2-
Chloracetamide.

The guanidine-based compound used in the present invention is a linear biguanide polymer whose repeating unit is represented by the following formula, where R1 and R4 are the same or different, and the total number of carbon atoms taken together is represents a bridging group in which 10 to 16.

Examples include polypentamethylene biguanide hydrochloride, polyhexamethylene biguanide hydrochloride, polyhebutamethylene biguanide hydrochloride, polyoctamethylene biguanide hydrochloride, and the like.

Preferably, the biguanide is polyoctamethylene biguanide hydrochloride having a number average molecular weight of 1,300 to 2,200.

In the CMC fibers used in the present invention, cellulose as a starting material is cuproammonium rayon, viscose rayon, cotton, pulp, etc. It is carboxymethylated according to Sho 60-2707, etc.).

The CMC fibers are preferably acarrimetal salts or ammonium salts, particularly sodium salts.

Next, the cable filling material of the present invention is used as a string-like product or a tape-like product obtained by processing filament, spun yarn, knitted woven fabric, or non-woven fabric. A plurality of filaments and spun yarns are collected and used in the form of strings, and knitted or nonwoven fabrics are formed into tapes, and the tapes are preferably coated 10 to 200 times/year.
It is used as a string by giving it a twist of m. In addition, the tape-like material may be used as is after being incorporated into the cough tape-like material, or may be used by combining the cough tape-like material with a reinforcing material selected from natural fibers and artificial fibers.

Hydrotactic spinnability in the present invention is evaluated by the initial water constant length (L) shown in Examples and the value obtained by subtracting the initial water running length from the water running length after 4 months (ΔL). , it can be said that the smaller both values are, the better the water running prevention property is.

(Effects of the Invention) - According to the present invention, a filling material for cables with excellent long-term water running prevention properties is provided, making a great contribution to the development of this industry.

(Evaluation method) l) Saturated water absorption capacity Measured by the tea bag method. That is, prepare a bag made of nylon nonwoven fabric with a length of 5 cm and a width of 6 cm, insert 0.3 g of sample into the bag, prepare multiple bags, and simultaneously immerse them in distilled water at 20 ° C. Take out one bag each time, hang it in the air for 7 minutes at room temperature, and drain the water.
The weight of the sample was measured, and the water absorption capacity was measured. The saturated water absorption capacity was defined as the water absorption capacity when the water absorption capacity reached equilibrium.

Water absorption capacity - (ffi of the sample after water absorption! - Weight of the sample before water absorption ff1) / (Weight of the sample before water absorption) 2) Water running length L with inner diameter 5 mm, height 1.2 m, horizontal length 1.2 m The water running length was measured using a molded glass tube with a cock attached at a position Im from the open end of the horizontal part.

First, a sample is filled into the horizontal tube 1000 mm after the cock. The filling rate is calculated using the following formula, and the sample is filled to a filling rate of 7%.

Filling rate = (weight of sample! (g)/glass tube 100
Volume of 0 mm (cm))*100 (%) Next, fill the 1000 mm vertical tube with water, open the cock, and let the water come into contact with the sample. For the sample in the horizontal pipe one day after opening the cock, the length of water submerged measured from the outlet of the cock (i.e., water running length) is the initial water running length (L), and the water running length after 4 months. The value obtained by subtracting the initial water running length from the water running length is displayed as the water running length increase value (ΔL).

Soil extracted water was used as water in the vertical pipe.

As soil extraction water, 500g of soil was added to distilled water of 21 and stirred for 6 hours. The subsequent supernatant was used. The number of viable bacteria in this supernatant was 101 cells/ml. In addition,
The soil is 1-15 Nakajima-cho, Nobeoka City, Miyazaki Prefecture. About 50am underground
Collected from.

The method for impregnating the water absorbent fibers with the preservative is to immerse the water absorbent fibers in a methanol solution in which the preservative is dissolved in methanol, and then dehydrate and dry the fibers.

In the present invention, an increase in water running length (ΔL) as a preservative effect on soil bacteria of 50 mm or less was determined to have a preservative effect.

Furthermore, the initial water running length as an evaluation measure of the water absorption performance of CMC fibers was judged to be good if it was close to or below the value without preservatives.

In addition, the saturated water absorption capacity was judged to be good if it was around the same value or higher than that without preservatives.

〔Example〕

The present invention will be further explained below with reference to Examples.

Example 1 CMC-IJa Cup obtained by the method described in Japanese Unexamined Patent Application Publication No. 15458/1985 filed by the applicant of the present invention
A water absorbent nonwoven fabric made of rafil was prepared. This nonwoven fabric was impregnated with various preservatives and subjected to evaluation.

The evaluation results are shown in Table 1.

Table 1: The amount of preservative deposited is 5% by weight based on the weight of the fibers.
Chloroacetamide 3, didecyldimethylammonium chloride 4, tributyltin oxide 5, naphthenic acid 6, zinc octylate 7, 2,4.4'-)lichloro 2'-hydroxydiphenyl ether 8, salicylic acid 9, sorbic acid 10, 1,3.5-)liethanoltriazine 11,
10.10”-oxybisphenoxyarsine 12.1
．． As is clear from Table 1, 2-benzisothiazolone-3-one 13, methylene biscyanate 14, and sodium dimethyldithiocarbamate salt, preservatives No. 1 to No. 6 are effective against soil bacteria.

In addition, preservatives No. 1 to 3.8 to No. 12 and No. 14 do not impair the excellent water absorption performance originally possessed by CMC fibers. It can be seen that there are three preservatives, 1 and 2.3, that satisfy both of these performances.

Example 2 Cuproammonium rayon filament 120'/75 was prepared according to the method described in JP-A-56-15458.
fil & viscose rayon filament 3001
50 fils were each converted into CMC-Na. Then, the results of measuring the saturated water absorption capacity, initial water running depth, and water running length increase value ΔL (m/m) of the sample obtained by impregnating the stiff water absorbent fiber with a preservative by the method of Example 1 are shown in the second table. Shown in the table.

Margin below Table 2 The amount of preservative applied was 5% based on the weight of the fibers.

The preservatives are the same numbers as in Example 1.

As can be seen from Table 2, preservatives No. 1, 2, and 3 are CMC-
It can be seen that it is also effective for Na-containing Cupra-fil and CMC-Na-containing viscose-fil.

Example 3 Same CMC-Na Cupra-f as used in Example 1
A nonwoven fabric made of il was prepared. The preservatives 1, 2.3 were applied to the nonwoven fabric, and the amounts of each of the preservatives 1 and 2.3 were applied in different amounts for evaluation. The results are shown in Table 3.

The preservatives used are the same numbers as in Example 1.

As can be seen from Table 3, the adhesion amount is 0.1% of the fiber weight.
% or more is effective, and preferably 1% or more, the preservative effect is more pronounced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a communication cable. ■・・・Tension member, 2...'X-ray, 3
...Filling material 1.4...Tape, 5...Outer skin layer Fig. 1 1...Tension member 2...Conducting wire 3°゛°Filling material 4...Tape 5...・Outer skin layer

Claims (1)

[Claims] A filling material for cables comprising a carboxymethylcellulose-based water-absorbing fiber containing at least 0.1% by weight of at least one compound selected from the group of quaternary ammonium salt compounds, acetamide-based compounds, and guanidine-based compounds.