JPH0476065A - Water-absorbent composition - Google Patents

Abstract

PURPOSE:To prepare the title compsn. improved in workability, water absorption rate, and water absorption capacity and capable of exhibiting its abilities even in sea water just like in water by compounding a thermoplastic elastomer, a highly water-absorbing resin, and a specific hydrophilic compd. CONSTITUTION:100 pts.wt. thermoplastic elastomer (e.g. an ethylene-propylene rubber), 10-3000 pts.wt. highly water-absorbing resin (e.g. a crosslinked polysodium acrylate), and 1-50 pts.wt. at least one hydrophilic compd. selected from the group consisting of a metal carboxylate, a polyhydric alcohol, an amino alcohol, a linear polyether, a saccharide, and a alcohol (e.g. sodium propionate) are mixed to give the title compsn., which is dissolved or dispersed in a solvent and applied to a substrate, etc., to give an article such as a water- absorbing tape wound under a rider roll.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water-absorbing material composition used in water-absorbing tapes for optical fiber cables and the like.

[Conventional technology]

Conventional waterproof optical fiber cables are classified into two types based on their waterproof type: (1) sherry-filled type and (2) water-absorbing material-filled type. The Sherry-filled type (■) above has multiple optical fiber cores arranged around the outer periphery of the central tension member, which is covered with a cable jacket via a non-woven fabric, and between the non-woven fabric and the optical fiber core. It is constructed by filling the gaps with a sherry-like compound. This type of fiber optic cable has excellent waterproof properties. However, the above-mentioned sherry-like compound is sticky and has poor wiping properties in that it cannot be wiped off without using an organic solvent, resulting in problems in manufacturing and workability.

As shown in FIG.
A plurality of optical fiber cores 13 are arranged along the circumference on the outer peripheral surface of the optical fiber core 13, and a water-absorbing spun yarn 14 is further arranged along the longitudinal direction between the two optical fiber cores 13. It is covered with a pressure-wound water-absorbing tape 15 made of water-absorbing fibers, and its outer peripheral surface is further covered with a cable sheath 16 (Japanese Patent Laid-Open No. 62-1.88109).

[Problem to be solved by the invention]

However, when using the press-wound water-absorbing tape 15 made of acrylic water-absorbing fibers, the acrylic water-absorbing fibers have a low water absorption capacity and a slow water absorption speed, so they are When applied to a waterproof optical fiber cable with grooves 3, it becomes necessary to arrange a narrow water absorbing tape 5 in the slot groove 3, as shown in FIG. In FIGS. 6 and 7, 1 is a tension member, 2 is a slot I, 4 is an optical fiber tape core, 6 is a water-absorbing tape layer, and 7 is a cable jacket. In other words, the pressure-wrapped water-absorbing tape made of acrylic water-absorbing fiber described in -1- has a low water absorption rate and a slow water absorption rate, so it is effective for waterproofing between the cable jacket 7 and the slot 2. In order to waterproof the inside of the provided slot groove 3, the swelling ratio is low and the inside of the groove 3 cannot be sufficiently waterproofed. Therefore, a narrow water-absorbing tape (1.5 to 3.0 mm width) 5 is arranged in the groove 3, and the narrow water-absorbing tape 5 itself absorbs water and swells to waterproof the inside of the groove 3. It has become. However, manufacturing an optical fiber cable by inserting the narrow water-absorbing tape 5 into each groove 3 in this manner is extremely time-consuming. Furthermore, recently, waterproof optical fiber cables have been used in a wide range of fields, and are now being used as submarine cables and the like. However, the optical fiber cable with the above structure uses a water-absorbing tape 6 made of acrylic water-absorbing fibers, and the acrylic fiber itself has a low water absorption rate and water absorption capacity for seawater (containing metal salts), so the cable Outer cover 7
The problem is that if there is a crack in the pipe, water can enter through the crack and run several tens of meters away.

As described above, the current situation is that there is no water absorbing material that is easy to work with, has a high water absorption rate and water absorption capacity, and can exhibit such water absorption performance in seawater as well as in fresh water.

This invention was created under these circumstances! The purpose of the present invention is to provide a water-absorbing material composition which has good workability, high water-absorbing speed and water-absorbing capacity, and exhibits the same performance in seawater as in fresh water.

[Means to solve the problem]

Jr. In order to achieve the object described above, the water absorbent material composition of the present invention has a configuration in which the following (A) to (C) are essential components.

(A) Thermoplastic elastomer (13) Super absorbent resin.

(C) Carboxylic acid metal salt 2 At least one hydrophilic compound selected from the group consisting of polyhydric alcohols, amino alcohols, linear polyethers, sugars, and sugar alcohols.

[Function] The water absorbing material composition of the present invention itself has an extremely high water absorption rate and water absorption capacity. Therefore, when this is applied in a layered manner to a base material such as a film, non-woven fabric, or sheet, and used as a water-absorbing tape for the above-mentioned optical fiber cable, etc., the 1-groove 3-inch groove as shown in FIG. Waterproof optical fiber half 1゛-
In the case of pulling, waterproofing can be achieved simply by winding the tape around the outer periphery of the slot 2 without disposing the narrow water-absorbing tape 5 in the groove 3. In addition, the water-absorbing material composition of the present invention exhibits the above-mentioned excellent performance not only in fresh water but also in seawater, etc., so for example, when it is used in water-absorbing tape for optical fiber cables, it can This makes it possible to limit the intrusion of seawater to an extremely short distance.

Next, this invention will be explained in detail.

In this invention, a special water-absorbing material composition is used as described in Section 2.

The above-mentioned special water-absorbing material composition is a thermoplastic elastomer (A
component), super absorbent resin (component B), and carboxylic acid metal salt,
It is constructed by blending at least one hydrophilic compound (component C) selected from the group consisting of polyhydric alcohols, amino alcohols, linear polyethers, sugars, and sugar alcohols. The ratio of the above components A to C is based on 100 parts by weight of component A (hereinafter referred to as "parts").
The ratio of the component is set to 10 to 3000 parts, and the C component is set to 1 to 50 parts. That is, if the usage ratio of each of the components described in Section 2 deviates from the above-mentioned range, it becomes difficult to obtain the desired effect, and therefore the usage ratio of each of the above-mentioned components is set within the above-mentioned range.

Specific examples of the thermoplastic elastomer (component A) include ethylene-propylene rubber (EPDM), black 1-prene rubber (CR), and styrene-butadiene rubber (SB
R), butyl rubber (IIR).

Examples include natural rubber (NR), styrene-butadiene block copolymer (SBS), styrene-isoprene block copolymer (SRS), ethylene vinyl acetate copolymer (EVA), and the like. These may be used alone or in combination.

Super absorbent resin used together with the above A component (B component)
Specific examples include crosslinked storium poly(meth)acrylate, crosslinked polyethylene oxide, crosslinked carboxymethylcellulose sodium salt starch-polyacrylate thulium grafted product starch-polyacrylonitrile graph I-
compound, cellulose-sodium polyacrylate11. Examples include vinyl alcohol-sodium (meth)acrylate-(meth)acrylic acid copolymer, alkali neutralized product of crosslinked isobutylene-maleic anhydride copolymer, polyoxyethylene chain-containing urethane, and the like. These may be used alone or in combination without any problem.

The hydrophilic compound (component C) used together with the above A component and B component has a low water absorption capacity and water absorption rate in the water absorbing material composition of the above A component and B component, and it is difficult to absorb water containing inorganic ions such as seawater. This is used to increase the hydrophilic compound (component C), since the hydrophilic compound (component C) is used to increase the hydrophilic compound. By adding component C, a high-speed, high-magnification water-absorbing material composition as described in section 2 can be obtained because the use of component C makes it possible to make component A, which is originally hydrophobic, hydrophilic. This is thought to be because the water absorption properties of component B can be fully utilized. Specific examples of such hydrophilic compounds (component C) include carboxylic acid metal salts, polyhydric alcohols, amino alcohols, linear polyethers, saccharides, and sugar alcohols. Representative examples of the above carboxylic acid metal salts and U7 include 1-lium acetate,
Sodium propionate J1. Examples include sodium stearate. In addition, typical examples of polyhydric alcohols include:
Diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, polyglycerin,
Examples include propylene glycol, jetanolamine, triethanolamine, and pentanostriol.

Typical examples of amino alcohols include jetanolamine and triethanolamine. In addition, typical examples of linear polyethers include boroxypropylene,
Examples include oxyethylene-oxypropylene block copolymers. Representative examples of sugars include glucose, course, and sucrose. Further, typical examples of sugar alcohols include tsuruhito, sorbitan mannitol, and mannitan. These hydrophilic compounds may be used alone or in combination.

The water absorbent composition of the present invention is produced as follows. That is, it is produced by blending the raw materials for components A to C in a predetermined ratio 7, and thoroughly cross-dispersing the mixture using a mixer such as a roll, kneader, or hammer milligizer. The water-absorbent composition of the present invention thus produced is dissolved and dispersed in a solvent such as toluene to form a solution, coated on a base material, etc., and finished as a pressure-wound water-absorbing tape or the like. In this case, the solution concentration is usually set at 10 to 50% (by weight, the same applies hereinafter). Note that specific examples of the above-mentioned base material include films, nonwoven fabrics, sheets, yarns, paper, and the like. Alternatively, the above solution may be applied to threads such as polyester, and several threads thereof may be twisted to form a water-absorbing yarn.

Next, FIG. 1 shows an optical fiber cable using the water-absorbing tape obtained as described above.

In this optical fiber cable, between the cable sheath 7 and the slot 2, the above-mentioned pressure-wrapping water-absorbing tape 6a is disposed. Note that this press-wound water-absorbing tape pro a has a two-layer structure of a water-absorbing material composition layer 21 and a base material layer 22.

Furthermore, as shown in FIG. 2, only the optical fiber tape cores 4 are accommodated in the slot groove 3 in a stacked state.

Other than that, it is the same as FIG. 6. In the optical fiber cable having such a structure, there is no need to arrange narrow water-absorbing tapes in each slot groove 3 as in the conventional case, so the structure is simple and manufacturing is easy. And cable jacket 7
When cracks occur in the cable and seawater infiltrates, the water-absorbing tape 6a absorbs water and swells, causing the slot 2 and the cable sheath 7 to swell.
At the same time, it absorbs water and swells into the slot groove 3, thereby waterproofing the inside of the groove 3. Therefore, the intrusion of water can be suppressed to a small extent. Further, the water-absorbing yarn obtained as described above was used as the water-absorbing spun yarn 14 in FIG.
You may use it instead. This makes it possible to adequately deal with seawater intrusion.

Next, examples will be described together with comparative examples.

[Example, comparative example]

Manufacture of Water Absorbing Material Composition> The above components A to C were blended in the proportions shown in Table 1 below, and cross-dispersed using a roll to prepare a water absorbing material composition.

<Manufacture of water-absorbing tape and water-absorbing yarn> The water-absorbing material composition obtained as above was dissolved in toluene to a concentration of 30
% solution was prepared, and this solution was laminated and coated on a nonwoven fabric to produce a pressure-wound water absorbent tape 6a as shown in FIG. 3(A). In FIG. 3(A), 21 is a water absorbing material composition layer (0.05 to 0.3 mm) of the tape 6a;
22 is a base material made of nonwoven fabric (0.1 to 0.3 mm)
It is.

In addition, using the Kitagi solution, it was attached (adhesion rate 100%) to polyester yarn (1000 denier) 1, and four of these were twisted together to form a water-absorbing yarn 5 as shown in Figure 3 (I3).
I made 0. In FIG. 3 (L-()), 51 is a polyester yarn, and 52 is a water absorbent composition layer.

The water absorption properties of the water absorbent tape and yarn thus obtained were measured and are also shown in Table 1 below.

In addition, since the water absorption characteristics of the water absorption tape and the water absorption yarn are almost the same, the characteristics of both are shown as the same value. The swelling ratio was determined by measuring the weight ratio before and after water absorption. In addition, water absorption was evaluated based on the above swelling ratio, and visual evaluation was also performed.

× indicates poor, △ indicates slightly poor, ◯ indicates good, and ◎ indicates extremely good.

(The following is a blank space) E4 <Measurement of water absorption performance of water absorption tape and water absorption yarn> Next, the water running properties of the water absorption tape 6a obtained as described above were measured using fresh water and seawater, as shown in Figure 4 (A). Measurements were made using a grooved rail as shown. In Figure 4 (A), 3
0 is the groove, 31 is the rail, 32 is the groove 30 of this rail 31
The pipe 6a for supplying water inside the rail 31 is a water-absorbing tape that is pressed down and is attached to the rail 31 with the water-absorbing material composition layer 21 facing the groove 30. In this measurement, the pipe 32
When the tank is filled with water to a height of 1 m and water is poured into the groove 30 by opening a cock (not shown) in that state, it depends on how long the water runs inside the groove 30 and is dammed up. We investigated water running properties. The shorter the length of water run, the better the results. Further, the water running properties of the water-absorbing yarn 50 were also measured using fresh water and seawater using a glass tube 60 as shown in FIG. 4(B). In Figure 4(B), 61
62 is a cock, and 62 is a vertical glass tube that is formed integrally with the glass tube 60 and extends vertically. This measurement is performed by filling the vertical glass tube 62 with water to a height of 1 m, then opening the container 1 and pouring water into the glass tube 60.How long does the water travel inside the glass tube 60? We are investigating water running ability based on whether it can be dammed. In this case too,
In this case, the shorter the length of the water run, the better the result. The results of these measurements are shown in Table 2.

(Hereinafter, blank spaces) As is clear from the table above, it can be seen that the Example products have extremely good water running properties.

〔Effect of the invention〕

As described above, the water-absorbing material composition of the present invention has high-speed water absorption,
Because it has high-magnification swelling properties, it can be used to make water-absorbing tape or yarn to waterproof optical fiber cables, making it possible to eliminate the need for conventional narrow tapes. Furthermore, since the above-mentioned high-speed water absorption and high-magnification swelling performance is achieved regardless of seawater or fresh water, the water-absorbing material composition of the present invention is suitable for applications such as water-absorbing materials for optical fiber cables for submarine cables.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the configuration of one application example of the present invention;
The figure is a partially enlarged cross-sectional view of the water-absorbing tape, Fig. 3 (A) is a cross-sectional view of the water-absorbing tape, Fig. 3 (B) is a partially enlarged perspective view of the water-absorbing yarn, and Fig. 4 (A) is the water run of the water-absorbing tape. Gender measurement explanatory diagram,
Figure 4 (B) is an explanatory diagram of water running properties measurement of water absorbing yarn, Figure 5
The figure is a sectional view of a conventional example, FIG. 6 is a sectional view of another conventional example, and FIG. 7 is a partially enlarged sectional view thereof. 6a... Pressure-wrapped water-absorbing tape 21... Water-absorbing material composition layer 22... Base material 50... Water-absorbing yarn 51.
... Polyester yarn 52 ... Water-absorbing material composition layer Patent applicant: Tokai Rubber Industries, Ltd. Sumitomo Electric Industries, Ltd.

Claims (1)

[Claims] (1) A water-absorbing material composition comprising the following (A) to (C) as essential components. (A) Thermoplastic elastomer. (B) Super absorbent resin. (C) At least one hydrophilic compound selected from the group consisting of carboxylic acid metal salts, polyhydric alcohols, amino alcohols, linear polyethers, sugars, and sugar alcohols.