JPH11106668A - Water stop resin mixture for cable joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a water stop resin mixture used for a joint part of a cable. SOLUTION: This water stop resin mixture is used for a joint part of a cable and is obtained by adding 10-100 pts.wt. highly water absorbing polymer to 100 pts.wt. base resin. The highly water absorbing resin is preferably an isobutylene-maleic anhydride. Extremely improved water stop functions are obtained by adding the highly water absorbing polymer according to the absorption of penetrated water itself and volume expansion of the resin itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a water-blocking resin mixture used for a joint portion of a cable.

[0002]

2. Description of the Related Art In the case of a cable laid on the sea floor or in a river, for example, as shown in FIG. Is covered with a tubular protection member 3, and a space between the protection member 3 and the outer periphery of the cable is filled with a water-stopping resin mixture 4,4. As the water-stopping resin mixture 4, polyurethane, epoxy resin or the like is usually used.

[0003]

However, water-blocking resin admixtures such as polyurethane and epoxy resins as described above 4
In this case, there is a problem that a gap is easily formed between the protective member 3 and the resin due to shrinkage at the time of curing the resin, and the water stopping function is impaired. For this reason, it is necessary to cure the resin at a low curing temperature so as not to cause resin shrinkage as much as possible, and there is also a problem that a reduction in workability cannot be avoided. Further, if a strong filling state cannot be obtained due to the shrinkage effect at the time of curing, the water-blocking resin admixture 4 is likely to be distorted by the action of external stress, and water may possibly enter. .

The present invention has been made in view of such a conventional problem, and an object of the present invention is to add a superabsorbent polymer to a base resin to solve the above conventional problem.

[0005]

The present invention according to claim 1 is a water-blocking resin admixture used for a joint portion of a cable, wherein 100 parts by weight of a base resin contains 10 to 100 parts by weight of a highly water-absorbing polymer. A water-sealing resin mixture for cable joints characterized by being added.

According to a second aspect of the present invention, there is provided the water-blocking resin admixture for a cable joint according to the first aspect, wherein the superabsorbent polymer is isobutylene-maleic anhydride.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the base resin used in the present invention include engineering plastics such as polyurethane such as isocyanurate and epoxy resin such as bisphenol A type liquid resin. On the other hand, examples of the superabsorbent polymer used in the present invention include an isobutylene-maleic anhydride copolymer, a saponified vinyl acetate / acrylate copolymer, and a polyethylene oxide polymer.

The amount of the superabsorbent polymer to be added is 10 to 100 parts by weight based on 100 parts by weight of the base resin. The reason is that if less than 10 parts by weight,
If a sufficient water stopping function cannot be obtained, and if it exceeds 100 parts by weight, the mechanical properties and workability of the admixture will be reduced, and inconvenience will occur. is there.

[0009] The addition of the superabsorbent polymer improves the water stopping function because even if there is a slight gap, the infiltrated water is taken into the polymer, so that it is difficult to reach the inner part of the cable joint. Because there is little. In addition, the volume of the resin itself expands due to the infiltration of the infiltration water, so that a stronger resin filling state can be obtained. This means, in other words,
If the joints are exposed to water due to laying on the sea floor or in the river, if there is some gap due to shrinkage during resin curing, etc. This means that the gaps are closed or the filling state becomes strong (hard) due to the action, and that a good water stopping function is obtained. Of course, due to this strong filling state, a large resistance to external stress is obtained, distortion is unlikely to occur, and a good water stopping function is obtained.

The resin admixture of the present invention is added with polyol, polyamine, etc. as a curing agent for the base resin, and if necessary, fillers such as tar, calcium carbonate, carbon black, silica, etc.
Other materials such as a curing accelerator such as an amine catalyst, a plasticizer, an emulsifier, and a hydrolysis inhibitor can also be added.

[0011]

EXAMPLES Next, a water-blocking resin admixture for cable joints of the present invention having the composition shown in Table 1 (Examples 1 to 5),
A cable joint portion was manufactured using a water-blocking resin admixture lacking the conditions of the present invention (Comparative Examples 1 to 4), and the water-blocking function (characteristic) was examined. Table 1 shows the water stopping characteristics.
It was also described in. In this case, the water stop performance is determined by applying a water pressure of 5 kgf / cm ² to one end (one end) of the cable joint.
It took 4 hours to measure the infiltration length of the intruded water.

[0012]

[Table 1]

From Table 1 above, the water-stopping resin admixture for cable joints of the present invention (Examples 1 to 5) showed good water-stopping properties. On the other hand, in the case of the water-blocking resin admixture (Comparative Examples 1 to 4) in which the superabsorbent polymer is not added or the amount of addition of the superabsorbent polymer is inadequate, the conditions of the present invention are insufficient. It can be seen that the water-stopping properties are insufficient due to the long water leakage, and that the processability is deteriorated if the amount of the superabsorbent polymer is too large.

[0014]

As described above, according to the present invention, since a predetermined amount of the superabsorbent polymer is added to the water-blocking resin admixture used for the joint portion of the cable, if the resin is hardened due to shrinkage during curing, etc. Even if a gap is formed or the resin filling state is loose, the water that has entered is effectively absorbed by the superabsorbent polymer. In addition, the absorption of the infiltration water causes volume expansion of the resin itself, and the gap easily disappears, so that the infiltration water hardly reaches the inside of the joint. As a result, an extremely effective water stopping function is obtained. Furthermore, if the resin itself expands in volume, a strong (hard) filling state is obtained, and the resistance to external stress is strong, and the joint portion is less likely to be distorted. An extremely effective water stopping function can be obtained. In addition, due to the action of the superabsorbent polymer, it is not necessary to deal with shrinkage during curing of the resin as strictly as before, so that the curing temperature can be set higher and the workability is improved. Can also be expected.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a cable joint portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cable 2 Joint part 3 Protective member 4 Waterproof resin mixture

Claims (2)

[Claims] 1. A water-blocking resin mixture for a cable, wherein the water-blocking resin admixture is obtained by adding 10 to 100 parts by weight of a superabsorbent polymer to 100 parts by weight of a base resin. Mixture. 2. The high water-absorbing polymer is isobutylene-
2. The water-blocking resin mixture for a cable joint according to claim 1, wherein the mixture is maleic anhydride.