JPH1036615A - Liquid-absorbing resin composition and material made from the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid-absorbing resin composition which can give a liquid-absorbing sheet, a liquid-absorbing film and a liquid-absorbing yarn which, when an aqueous solution penetrates into a communication cable such as an optical fiber cable or a power cable, are capable of effectively preventing the solution from intruding in the longer or inward direction of the cable. SOLUTION: This invention provides a liquid-absorbing resin composition prepared by mixing 100 pts.wt. powder of a liquid-absorbing N-vinylcarbonamide resin obtained from a monomer based on an N-vinylcarbonamide represented by the formula (R1 and R2 , which are independent of each other, are hydrogen atoms or methyl groups or may be combined with each other to form a 3 or 4C alkalene) with 10-100 pts.wt. adhesive resin comprising a synthetic resin or a synthetic rubber, an organic solvent and optionally 0.1-5 pts.wt. anionic or nonionic surfactant and a liquid-absorbing sheet prepared by coating or impregnating at least either surface of a woven or nonwoven fabric made of a synthetic fiber with this composition in a dry coverage of 10-200g/m<2> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-absorbent resin composition, a tape, a film, and a yarn using the same, and a longitudinal direction of a cable when an aqueous solution enters a communication cable such as an optical fiber cable or a power cable. And a cable mounted with such a material in order to prevent the aqueous solution from running inward.

[0002]

2. Description of the Related Art Conventionally, in order to prevent water running in a communication cable such as an optical fiber cable or a power cable which is exposed to wind and rain or seawater in an external environment, water stops for various cables. Water material is used. Among them, waterproof cable made of water-absorbing material has been low in cost and maintenance-free in recent years.
Attention has been paid to its good connection workability, and it is becoming widespread.

As the water-stopping material used for the waterproof cable, various materials such as a water-absorbing press tape, a water-absorbing tape, and a water-absorbing yarn are used. ing. For example, as a water-absorbing press-wrap tape, 1) a sandwich type tape in which a water-absorbing resin powder is interposed between two polyester long-fiber non-woven fabric sheets (Japanese Utility Model Application Laid-Open No. 59-479)
No. 14, JP-A No. 14-129228), 2) A coating type tape in which a coating material obtained by mixing a powdery or granular water-absorbent resin and a resin binder is applied to one or both surfaces of a polyester long-fiber nonwoven fabric sheet (Japanese Utility Model Application Laid-Open No. 61-129228). Etc. are devised,
Has been put to practical use. As the water-absorbing tape, for example, a tape in which a paint composed of a water-absorbing resin and a resin binder is applied to both surfaces of a polyester tape having a thickness of 20 to 50 μm has been put to practical use. Furthermore, as a water-absorbing yarn,
1) a spun yarn made of a water-absorbent acrylic short fiber; 2) a yarn in which a water-absorbent resin powder and a resin binder are applied to a plastic string or the like (JP-A-60-150506);
A yarn in which a water-absorbing resin powder and a resin binder are adhered around a slit or split plastic yarn (JP-A-62-259305) has been devised and put into practical use.

Conventionally, water-absorbing resins which can be used for these water-stopping materials include polyacrylic acid (salt) -based water-absorbing agents,
Starch / Acrylate-grafted water-absorbing agent, Starch /
Acrylonitrile graft saponified water absorbent, polysaccharide /
There are a variety of water-absorbing agents such as acrylate-grafted water-absorbing agents, carboxymethylcellulose-based water-absorbing agents, and acrylamide / acrylate copolymer-based water-absorbing agents. These water-absorbing agents absorb tap water with a low salt concentration relatively well. Therefore, although a sufficient water-stopping effect is exhibited, since seawater having a high salt concentration can hardly absorb water, there is a problem that water cannot be stopped substantially when seawater or the like enters the cable. As a method for solving this problem, Japanese Patent Application Laid-Open No. 1-240547 has proposed the use of an isobutylene / maleic anhydride copolymer-based water-absorbing agent or a sulfoalkyl (meth) acrylate / (meth) acrylic acid-based water-absorbing agent. . These water-absorbing agents have relatively high salt resistance as compared with conventional water-absorbing agents.
It is said that water can be absorbed 30 to 30 times. However, it is difficult to say that these water absorbing agents have sufficient water absorbing ability. Further, a modified polyalkylene oxide-based water absorbing agent,
Water absorbing agents mainly composed of nonionic monomer units such as vinyl alcohol-based water absorbing agents have relatively high salt resistance, but these water absorbing agents also have insufficient water absorbing ability. Further, it has been considered to use an existing sewage ditch in attaching an optical fiber cable. In such a case, not only the salt water,
It is also required to have a liquid absorbing property for sewage containing surfactants such as detergents and oils. However, a water-absorbing material that can effectively absorb such sewage has not been developed at present.

[0005] In addition, the water-absorbing agent used for the water-stopping material for cables is required to have heat resistance, light stability, and microbial resistance.
All of the conventional water-absorbing agents exemplified above have low heat resistance and light stability, and particularly when heated or exposed to light while absorbing water, the water-absorbing agent is easily decomposed, and the water-absorbing ability (water-stopping effect) is large. However, there is a disadvantage that it is lowered. Communication cables and power cables are installed in places with various environments around the world.However, if the heat resistance is low as described above, the installation place is naturally limited to areas with mild temperatures, such as in deserts. There is a problem that it cannot be installed in areas with high temperatures. Also, when used as a waterproof material for optical fiber cables,
High light stability is an essential condition because light always hits the waterproof material at the joint. Furthermore, among the conventional water-absorbing agents, starch, cellulose, polysaccharides, and vinyl alcohols are decomposed by microorganisms to generate hydrogen gas, and this hydrogen gas diffuses into the optical fiber core wire, resulting in loss of hydrogen absorption. In addition, absorption loss occurs due to the OH group formed by combining the hydrogen with the dopant in the optical fiber, and the transmission characteristics are significantly deteriorated. As described above, the conventional water-absorbing agent that has been used as a raw material of a water-stopping material for a cable has various disadvantages, and has a problem that the performance is insufficient for a water-stopping material for a cable.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to exhibit high water absorption and swelling even when an aqueous solution having a high salt concentration, such as seawater, enters a cable, exhibiting a water stopping effect, and has heat resistance and light resistance stability. The purpose of the present invention is to develop a liquid-absorbent resin composition having excellent properties and microbial resistance, and to develop a sheet, film, or yarn using the same.

[0007]

Means for Solving the Problems The result of intensive studies to achieve the above object. The present inventors have found that a liquid-absorbent resin composition having a specific composition and a liquid-absorbent material using the same are suitable, and have reached the present invention. That is, the general formula [1]

Embedded image [Wherein R ₁ and R ₂ independently represent hydrogen or a methyl group, or R ₁ and R ₂ are bonded to each other to represent an alkylene group having 3 to 4 carbon atoms. And an adhesive resin comprising a synthetic resin or a synthetic rubber, and 100 parts by weight of an N-vinylcarboxylic acid amide-based liquid-absorbent resin powder obtained from a monomer having N-vinylcarboxylic acid amide as a main component represented by the formula: A liquid-absorbent resin composition comprising 10 to 100 parts by weight, an organic solvent, and, if necessary, 0.1 to 5 parts by weight of an anionic or nonionic surfactant; Is coated or impregnated on at least one surface of a woven or non-woven fabric made of synthetic fibers so as to have a dry adhesion amount in the range of 10 to ²⁰⁰ g / m ² , or the composition is used as a synthetic resin film. At least one side has a dry adhesion amount of 10 to 2
The above-mentioned liquid-absorbing resin composition is dried and adhered to a liquid-absorbing film which is coated or impregnated so as to be in the range of 00 g / m ² , or a yarn made of synthetic film or synthetic fiber long fiber. It is a liquid-absorbent yarn which is coated or impregnated so as to have an amount of 0.1 to 10 g / m ² , and a cable on which at least one of them is mounted.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The liquid-absorbent resin composition of the present invention uses an N-vinylcarboxylic acid amide-based liquid-absorbent resin powder. This liquid-absorbent resin powder can absorb a wide range of aqueous solutions such as high-concentration salt solutions such as seawater, acidic water, alkaline water, and alcohol aqueous solutions, and is also a material that is excellent in heat resistance and light resistance. It also has the excellent feature that it is not decomposed by microorganisms. N-
The vinyl carboxylic acid amide-based liquid-absorbing resin powder comprises the N-vinyl carboxylic acid amide represented by the above general formula (1) and, if necessary, another monomer copolymerizable with the N-vinyl carboxylic acid amide. It can be produced by radical polymerization in the presence of a crosslinkable monomer.

The N-vinylcarboxylic amide used in the present invention includes N-vinylacetamide, N-methyl-N-vinylacetamide, N-vinylformamide,
N-methyl-N-vinylformamide, N-vinylpyrrolidone and the like can be mentioned, among which N-vinylacetamide is particularly preferred.

The monomers copolymerizable with these N-vinylcarboxylic acid amides include (meth) acrylic acid and its salts such as sodium, potassium, lithium and ammonium, its methyl ester, ethyl ester, propyl ester and butyl. Alkyl esters such as esters, hydroxyethyl esters, hydroxyalkyl esters such as hydroxypropyl esters, their dimethylaminomethyl esters, alkyl esters substituted with lower alkylamino groups such as dimethylaminoethyl esters, their trimethylammonioethyl ester halides, Lower alkyl esters substituted with a quaternary ammonium group such as trimethylammoniopropyl ester halide, its sulfomethyl ester, sulfoethyl ester, linear or branched sulfonyl ester Esters substituted with alkylsulfonic acids or salts thereof, such as propyl esters, sulfobutyl esters and salts thereof such as sodium, potassium, lithium, ammonium, etc., (meth) acrylamide, its methylamide, ethylamide, linear or branched Alkylamides substituted with alkyl groups such as propylamide and butylamide; amides substituted with alkylamino groups such as dimethylaminomethylamide, dimethylethylamide and dimethylpropylamide; trimethylammonioethylamide halides and trimethylammonium Alkylamides substituted with a quaternary ammonium group such as propylamide halide, sulfomethylamide, sulfoethylamide, linear or branched sulfopropylamide, sulfob Ruamido and their sodium, potassium, alkyl sulfonic acid or amide substituted with a salt, such as salts such as lithium, ammonium, (meth) acrylonitrile, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether,
Methyl vinyl ketone, vinyl ketone such as ethyl vinyl ketone, vinyl acetate, lower vinyl carboxylate such as vinyl propionate, allyl sulfonic acid and its sodium,
Potassium, lithium, ammonium salts and the like, maleic acid, fumaric acid, itaconic acid and their sodium, potassium, lithium, ammonium and the like salts, vinylsulfonic acid and sodium, potassium, lithium, ammonium and the like various things. However, it is of course possible to copolymerize monomers other than those exemplified. Among these, N- is a monomer which is relatively inexpensive and easily available, and is highly absorbable even in an aqueous solution having a high salt concentration.
In order to obtain a vinyl carboxylic acid amide-based liquid absorbing agent, hydroxyalkyl (meth) acrylate, (meth) acrylic acid
Acrylic acid (salt), 2-acrylamido-2-methylpropanesulfonic acid (salt), vinylsulfonic acid (salt), maleic acid (salt), itaconic acid (salt) and the like are particularly preferred.
Needless to say, two or more of these monomers can be used simultaneously.

The ratio of N-vinyl carboxylic acid amide to the monomer copolymerizable with the N-vinyl carboxylic acid amide is preferably from 100: 0 to 50:50 by weight. If the ratio of the body is high, the liquid absorbing ability (magnification) of the aqueous solution having a high salt concentration is reduced, and the heat resistance, the light resistance and the like are undesirably reduced.

The N-vinylcarboxylic acid amide-based liquid absorbing resin powder used in the present invention must be crosslinked (insolubilized) by any method in order to exhibit a sufficient water-stopping effect. As a cross-linking method, a compound having two or more polymerizable unsaturated groups in one molecule and / or another monomer copolymerizable with N-vinylcarboxylic acid amide may be used as a mixture of the monomer (mixture). A method is used in which a compound capable of forming a chemical bond by reacting with a functional group therein (these compounds are referred to as a cross-linking agent) is added, followed by cross-linking together with polymerization of the monomer.

Examples of the crosslinking agent having two or more polymerizable unsaturated groups in one molecule used in the crosslinking include tetraallyloxyethane, pentaerythritol tetraallyl ether, pentaerythritol triallyl ether,
Pentaerythritol diallyl ether, trimethylolpropane diallyl ether, trimethylolpropane diallyl ether, ethylene glycol diallyl ether, diethylene glycol diallyl ether, triethylene glycol diallyl ether, diallyl ether, monosaccharides, disaccharides, polysaccharides, hydroxyl groups such as cellulose Polyallyl ether derived from a compound having two or more in one molecule, tetraallyl pyromellitate, triallyl trimellitate, triallyl citrate, diallyl oxalate, diallyl succinate, diallyl adipate, diallyl maleate, diallyl fumarate , Diallyl terephthalate, diallyl isophthalate, diallyl phthalate, polyallyl ester derived from compounds having two or more carboxyl groups in one molecule Ether, diallylamine, triallyl isocyanurate, such as triallyl cyanurate 1
Compounds having two or more allyl groups in the molecule, divinyl oxalate, divinyl malonate, divinyl succinate, divinyl glutarate, divinyl adipate, divinyl pimerate, divinyl maleate, divinyl fumarate, trivinyl citrate, trimellit Compounds having two or more vinyl ester structures in one molecule, such as trivinyl acid and tetravinyl pyromellitic acid, N, N'-butylenebis (N-
Vinylacetamide), N, N'-diacetyl-N, N '
Bis (N-vinylcarboxylic acid amide) compounds such as -divinyl-1,3-bisaminomethylcyclohexane,
N, N'-methylenebisacrylamide, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Pentaerythritol tri (meta)
Any known compounds such as compounds having a plurality of acrylamide structures or (meth) acrylic groups, such as acrylates, and compounds having two or more unsaturated groups in one molecule, such as divinylbenzene, divinyl ether, and allyl (meth) acrylate. Can be used. In addition, one or more of these crosslinking agents can be used.

[0014] Other crosslinking methods include a method in which an uncrosslinked crosslinked precursor polymer is prepared in advance, and this is reacted with a functional group in the polymer to form a chemical bond, radiation, peroxide, or the like. Various methods, such as a crosslinking method, may be mentioned.

Crosslinking agents capable of forming a chemical bond by reacting with a functional group (eg, a hydroxyl group, a carboxyl group, etc.) in a monomer or a polymer include polyglycidyl ether, polyglycidyl ether, and the like according to the functional group. Isocyanates, polyamines, polyols, polycarboxylic acids and the like can be mentioned. The amount of these crosslinking agents used is usually based on all monomers,
The ratio of monomer: crosslinking agent is 90:10 to 99.99 by weight.
9: 0.001.

By pulverizing the liquid absorbing resin obtained by the above method, a liquid absorbing resin powder can be obtained. Liquid-absorbing resin powder is generally 10 to 1000 μm
Having a particle size of Further, the adhesive resin used in the liquid-absorbent resin composition of the present invention functions to prevent the liquid-absorbent resin powder from falling off and adhere the water-absorbent resin powder to various substrates. Specific examples of the adhesive resin include an acrylic adhesive resin, a urethane adhesive resin, an ethylene adhesive resin such as an ethylene-acrylic acid copolymer and an ethylene-vinyl acetate copolymer, and a polyamide adhesive resin. Resins, polyisoprene rubber, butyl rubber, ethylene-propylene rubber, acrylic rubber, and the like are included. The adhesive resin used here is desirably a non-halogen resin. Two or more of these adhesives can be used simultaneously. The compounding amount of the adhesive resin is in the range of 10 to 100 parts by weight based on 100 parts by weight of the N-vinylcarboxylic acid amide-based liquid absorbing resin powder. If it exceeds 100 parts by weight, the liquid absorbing property of the liquid absorbing resin powder is impaired, which is not preferable. Conversely, if the amount is less than 10 parts by weight, the adhesion between the liquid-absorbent resin powder and the substrate becomes insufficient, which is not preferable.

The resin composition of the present invention may further contain an anionic or nonionic surfactant, if necessary. The use of a surfactant can be expected to further promote the liquid absorption of the obtained resin composition. Examples of the anionic surfactant used here include fatty acid soap, sodium linear alkylbenzene sulfonate, α-olefin sulfonate,
Examples thereof include alcohol sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, alkyl methyl tauride, and dialkyl sulfosuccinate. Nonionic surfactants include, for example, polyether surfactants, alkylphenol surfactants, polyester surfactants, sorbitan ester ether surfactants, alkylamine surfactants, polyoxyethylene polyoxy Propylene block copolymer surfactants and the like. Two or more of these surfactants can be used simultaneously. The amount of the surfactant used is N-vinylcarboxylic acid amide-based liquid absorbing resin powder 10
The range of 0.1 to 5 parts by weight relative to 0 parts by weight is appropriate. If it is less than 0.1 part by weight, the effect of addition cannot be expected, and
Exceeding the parts by weight can no longer be expected to improve the effect of promoting liquid absorption.

The organic solvent used in the liquid-absorbent resin composition of the present invention can dissolve the above-mentioned adhesive resin and is not absorbed by the N-vinylcarboxylic acid amide-based liquid-absorbent resin powder. Any organic solvent may be used. Particularly preferred examples of such organic solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, ethyl acetate, dioxane, tetrahydrofuran, hexane, cyclohexane and the like. These can be used alone or in combination.

The above-described liquid-absorbing resin composition may be used by adding an inorganic filler as necessary for the purpose of enhancing the liquid-absorbing property. Examples of such inorganic fillers include calcium carbonate, aluminum hydroxide, magnesium hydroxide, zinc white, clay, talc, silica, hydrous calcium silicate, and hydrous aluminum silicate. The amount used when mixing these inorganic fillers is generally in the range of 5 to 200 parts by weight based on 100 parts by weight of the N-vinylcarboxylic acid amide-based liquid-absorbing resin powder.

The liquid-absorbent resin composition of the present invention may further contain, if necessary, conductive fibers such as short fibers such as synthetic fibers and ceramic fibers, carbon, graphite, and metal powders.
-Corrosion inhibitors such as benzotriazole, flame retardants such as aluminum hydroxide and ammonium polyphosphate, crosslinking (vulcanizing) agents and crosslinking (vulcanizing) auxiliaries for crosslinking (vulcanizing) binders, various types of aging Various additives such as an inhibitor and a wetting agent for improving the water wettability of the binder can also be used. The liquid-absorbent resin composition of the present invention produced as described above can be used in various forms of materials such as a liquid-absorbent sheet, a liquid-absorbent film, or a liquid-absorbent yarn, especially a water-blocking material (water-blocking material). Can be processed.

The liquid-absorbent sheet of the present invention is obtained by applying and impregnating one or both surfaces of a woven or nonwoven fabric (hereinafter abbreviated as a base cloth) made of synthetic fibers with the above-mentioned liquid-absorbent resin composition. be able to. The base fabric used here has a strength enough to withstand the tension at the time of winding in the cable manufacturing process and is not subjected to decomposition by microorganisms. Specifically, for example, a woven or nonwoven fabric manufactured from a polyolefin-based fiber such as a polyester fiber, a nylon fiber, an acrylic fiber, and a polypropylene fiber may be used. The thickness of the nonwoven is generally 2
Those having a size of 0 to 500 μm are used.

The liquid-absorbent film of the present invention can be obtained by impregnating or coating the liquid-absorbent resin composition on one or both sides of a synthetic resin film. The synthetic resin film used here has a strength enough to withstand the tension at the time of inserting the rod groove in the cable manufacturing process, and does not undergo decomposition by microorganisms. Specific examples include a polyolefin-based film such as a polypropylene film and a polyethylene film, a polyester film, a nylon film, a polycarbonate film, and a polybutene film. The thickness of these synthetic resin films is generally 20
２００200 μm is used. The above-described liquid-absorbent sheet and liquid-absorbent film may be further laminated on one or both surfaces directly or via an adhesive layer with another material in order to increase an opportunity strength such as a tensile strength. It can be. Examples of such other materials include films, nonwoven fabrics, and polyolefin resins such as polyester, polyamide, polypropylene, and polyethylene.
Cloth and the like.

The liquid-absorbent yarn of the present invention is obtained by applying and impregnating the above-mentioned liquid-absorbent resin composition on the entire surface of a synthetic fiber long fiber or a plastic yarn (hereinafter abbreviated as base yarn). Can be. The base yarn used here has a strength enough to withstand the tension at the time of inserting the rod groove in the cable manufacturing process, and does not undergo decomposition by microorganisms. Specifically, for example, a synthetic resin long fiber such as polyolefin long fiber such as polypropylene, polyester long fiber, or nylon long fiber, or a plastic obtained by cutting a polyolefin film such as polypropylene or polyethylene, a polyester film, or a nylon film is used. Yarn and the like. The thickness of the base yarn is generally 1000 to 5000
A denier of 0 is used.

In the above-described liquid-absorbent sheet, liquid-absorbent film and liquid-absorbent yarn, the dry adhesion amount of the liquid-absorbent resin composition is 10 to 200 g / m ^{2 for} the liquid-absorbent sheet.
Absorbent film 10 to 200 g / m ^2, a range absorbent yarn of 0.1 to 10 g / m ^2. If the amount is less than this, an effective water stopping effect cannot be obtained. If the amount is more than this, each material is too hard to be used in the cable manufacturing process and is not economical.

The various liquid-absorbing materials of the present invention are not only excellent in heat resistance and light resistance, but also do not contain halogen compounds and are not decomposed by microorganisms. Reliability can be maintained. In addition, various liquid absorbing materials according to the present invention absorb not only distilled water and tap water, but also alkaline water, acidic water, seawater, etc., as well as sewage containing surfactants and oils, and swell by absorbing liquid. When used as a water-stopping material, excellent water-stopping ability can be exhibited.

FIG. 1 shows an example of a cross-sectional structure of a waterproof optical fiber cable using the liquid absorbing material of the present invention. Structurally, the liquid-absorbent sheet 6 is wound around the peripheral surface of the polyethylene grooved rod 2 having the FRP tensile member 3 at the center and a plurality of grooves 4 formed in the periphery in the longitudinal direction. A polyethylene jacket 1 is sequentially provided thereon, and an optical fiber ribbon 5 and a liquid-absorbent film 7 are housed in the groove 4 of the grooved rod 2. Further, the liquid absorbing yarn 8 is stored in the empty groove in which the optical fiber ribbon is not stored. In the cable having the above-described structure, when the jacket 1 is deteriorated or damaged due to some accident, and water enters the cable from the damaged portion, the liquid-absorbent sheet disposed at a specific portion of the cable. 6. The liquid-absorbent film 7 and the liquid-absorbent yarn 8 expand by absorbing water, stop water only in the vicinity of the entry point, and prevent water from running in the cable, particularly in the longitudinal direction. Accidents caused by water can be prevented. The various liquid-absorbing materials of the present invention can be used not only for optical fiber cables, but also for communication cables or power cables of any structure.

[0027]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, Reference Examples and Comparative Examples, but the technical scope of the present invention is as follows.
It is not limited by the following description.

Reference Example (Production Example A of N-vinylcarboxylic acid amide-based liquid-absorbent resin powder) In a bath maintained at 30 ° C., a three-necked tube provided with a nitrogen inlet tube, a thermometer, and an exhaust tube. N- in a 1 L separable flask
Dissolve 250 g of vinylacetamide and 600 mg of tetraallyloxyethane in 745 g of deionized water, and add 0.5 L
Per minute, nitrogen was introduced into the system for about 1 hour to degas. Then, 2,2'-azobis (2-
Amidinopropane) dihydrochloride (75 mg) was added, and the mixture was allowed to stand for 12 hours in an adiabatic system. The obtained gel was cut with a mincer, dried in vacuo at 50 ° C. for 12 hours, and sieved to obtain a particle size of 50 to 10.
0 μm of the liquid absorbent resin powder A was obtained.

(Production Example N of N-vinylcarboxylic acid amide-based liquid-absorbent resin powder) In a bath maintained at 30 ° C, a three-necked 1-L separable flask equipped with a nitrogen inlet tube, a thermometer, and an exhaust tube. N-vinylacetamide in 175 g, 28.5%
263 g of an aqueous solution of sodium acrylate, 300 mg of tetraallyloxyethane and 200 mg of N, N-methylenebisacrylamide were dissolved in 560 g of deionized water.
Nitrogen was introduced into the system at 0.5 L / min for about 1 hour to degas. Thereafter, 75 mg of 2,2′-azobis (2-amidinopropane) dihydrochloride dissolved in 5 mL of degassed water was added,
It was left standing for 12 hours in an adiabatic system. The obtained gel was cut with a mincer, dried under vacuum at 50 ° C. for 12 hours, and sieved.
A liquid absorbing resin powder B having a thickness of 00 to 200 μm was obtained.

(Production Example N of N-vinylcarboxylic acid amide-based liquid-absorbent resin powder) A three-necked 1-L separable flask equipped with a nitrogen inlet tube, a thermometer, and an exhaust tube in a bath maintained at 30 ° C. In the solution, 250 g of N-vinylacetamide and 600 mg of tetraallyloxyethane were dissolved in 745 g of deionized water, and nitrogen was introduced into the system at 0.5 L / min for about 1 hour to degas. Thereafter, 75 mg of 2,2′-azobis (2-amidinopropane) dihydrochloride dissolved in 5 mL of degassed water was added, and the mixture was allowed to stand in an adiabatic system for 12 hours. The obtained gel was cut with a mincer, vacuum dried at 50 ° C. for 12 hours, and sieved to obtain a liquid-absorbent resin powder C having a particle size of 50 to 400 μm.

(Example A-1) 100 parts by weight of butyl rubber was charged into 200 parts by weight of toluene, and dissolved by stirring overnight with a stirrer to obtain a rubber solution. 200 parts by weight of the liquid-absorbent resin powder A and 400 parts by weight of toluene were added to this rubber solution, stirred and mixed to obtain a liquid-absorbent resin composition (1).

Example A-2 In the same manner as in Example A-1, 100 parts by weight of an ethylene-vinyl acetate copolymer (25% by weight of vinyl acetate), 500 parts by weight of liquid-absorbent resin powder B, interface An absorbent resin composition (2) comprising 5 parts by weight of sodium dodecylbenzenesulfonate and 1000 parts by weight of toluene as an activator was obtained.

(Example A-3) In the same manner as in Example A-1, 100 parts by weight of polyisobutylene rubber, 150 parts by weight of liquid-absorbent resin powder C, 0.3 parts by weight of diethylene glycol monodecyl ether as a surfactant A liquid-absorbent resin composition (3) comprising 20 parts by weight of silica and 800 parts by weight of toluene as an inorganic filler was obtained.

(Comparative Example A-1) In the same manner as in Example A-1, an absorbent made up of 100 parts by weight of butyl rubber, 200 parts by weight of Aquaric CA (sodium polyacrylate-based water absorbing agent) and 600 parts by weight of toluene. Liquid resin composition (A)
I got

(Comparative Example A-2) In the same manner as in Example A-1, 100 parts by weight of butyl rubber, Aqualic CS-8
A liquid-absorbent resin composition (B) comprising 200 parts by weight of S (sodium acrylsulfonate-based water-absorbing agent) and 600 parts by weight of toluene was obtained.

(Comparative Example A-3) Polyisobutylene rubber 1
Except that 00 parts by weight, 50 parts by weight of the liquid-absorbent resin powder A and 600 parts by weight of toluene were used, a liquid-absorbent resin composition (C) was obtained under the same conditions and method as in Example A-1.

(Example B-1) The resin adsorbent resin composition (1) of Example A-1 was applied to both surfaces of a polyester long-fiber nonwoven fabric (having a basis weight of 40 g / m ² ) with a dry adhesion amount of 50 g / m ^2. After removing the solvent by drying, the resultant was cut into a tape having a width of 25 mm to obtain a liquid-absorbent sheet (1). The thickness of the sheet was about 0.2 mm. The liquid-absorbent sheet obtained for a length of 1.95 m was wound around a glass rod having a diameter of 10 mm and a length of 2.0 with 1/2 wrap. The glass rod around which the sheet was wound was inserted into a glass tube having an inner diameter of 12 mm and a length of 2 m. Next, the composite glass tube is kept horizontal, one side of the glass tube is subjected to water leakage prevention, and a vinyl chloride tube is connected. From a distance of 1.2 m in height, tap water and artificial sea water (Yasu Chemicals: Aqua) (Marine), alkaline water (Wako Pure Chemical: N / 10 NaOH aqueous solution), and acidic water (Wako Pure Chemical: N / 10 H ₂ SO ₄ aqueous solution) were respectively introduced into a glass tube, and after 24 hours, each water running distance was measured. did. The results are summarized in Table 1. All of the aqueous solutions are water-stopped within 1 m, which indicates that they exhibit good water-stopping properties. Separately, a similar composite glass tube was prepared, and four 100-w high-pressure mercury lamps were installed in parallel at a distance of 50 cm from the glass tube at equal intervals, and the entire high-pressure mercury lamp and the composite glass tube were covered with aluminum foil. While irradiating light, prevent water leakage on one of the glass tubes and connect the PVC tube,
Tap water, artificial seawater (Yasu Pharmaceutical: Aquamarine), alkaline water (Wako Pure Chemical: N /
10NaOH aqueous solution), acidic water (manufactured by Wako Pure Chemical Industries, Ltd .: N / 10)
H ₂ SO ₄ aqueous solution) were each introduced into a glass tube. After irradiating with light for 200 hours as it was, the running distance of each was measured. The results are also summarized in Table 1. In this case as well, the water was stopped within 1 m, and it can be seen that the water stopped was good.

(Examples B-2 and 3 and Comparative Examples B-1 to B-1)
3) Similarly to Example B-1, a liquid-absorbent sheet was produced using the liquid-absorbent resin compositions of Examples A-2 and A-3 and Comparative Examples A-1 to A-3, and evaluated. Table 1 summarizes the results.

[0039]

[Table 1]

Example C-1 The resin composition of Example A-1 was coated on both sides of a polyethylene film (thickness: 60 μm) so as to have a dry adhesion amount of 60 g / m ^2.
Dried. This film was slit into a tape having a width of 1.3 mm to obtain a liquid absorbing film. The obtained liquid-absorbent film was placed in a hollow tube (pore cross section: 0.6 mm × 1.6).
mm), the water absorption and the ultraviolet resistance were evaluated in the same manner as in Example B-1, and the water running distance was measured. Table 2 summarizes the results.

(Examples C-2 and C-3 and Comparative Examples C-1 to C-1)
3) In the same manner as in Example C-1, liquid-absorbent films were produced using the water-absorbent resin compositions of Examples A-2 and A-3 and Comparative Examples A-1 to A-3, and evaluated. Table 2 summarizes the results.

[0042]

[Table 2]

(Example D-1) Polypropylene yarn (2000 denier) was impregnated with the resin composition of Example A-1 to a dry weight of 0.5 g / m, dried, and then twisted. Thus, a liquid absorbing yarn was obtained. The obtained liquid-absorbent yarn was inserted into the hollow tube used in Example C-1, and the water absorption and ultraviolet resistance were evaluated in the same manner as in Example B-1 to measure the water running distance. Table 3 summarizes the results.

(Examples D-2, 3 and Comparative Examples D-1 to D-1)
3) In the same manner as in Example D-1, liquid-absorbent yarns were produced using the water-absorbent resin compositions of Examples A-2 and 3 and Comparative Examples A-1 to A-3, and evaluated. Table 3 summarizes the results.

[0045]

[Table 3]

[0046]

The liquid-absorbent resin composition of the present invention is capable of absorbing a wide range of aqueous solutions such as high-concentration salt solutions such as seawater, acidic water and alkaline water, and has heat resistance and light resistance. Also excellent in nature. Therefore, the liquid-absorbent sheet, liquid-absorbent film or liquid-absorbent yarn using the present resin composition may move in the longitudinal direction and inward direction of the cable when an aqueous solution enters a communication cable such as an optical fiber cable or a power cable. It is possible to effectively prevent the aqueous solution from running.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a waterproof optical fiber cable using a liquid-absorbent material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cable covering material 2 Slotted grooved rod 3 Strength member 4 Groove 5 Optical fiber tape core wire 6 Liquid absorbing sheet 7 Liquid absorbing film 8 Liquid absorbing yarn

Claims (6)

[Claims] [Claim 1] The following general formula [1] [Wherein R ₁ and R ₂ independently represent hydrogen or a methyl group, or R ₁ and R ₂ are bonded to each other to represent an alkylene group having 3 to 4 carbon atoms. And an adhesive resin comprising a synthetic resin or a synthetic rubber, and 100 parts by weight of an N-vinylcarboxylic acid amide-based liquid-absorbent resin powder obtained from a monomer having N-vinylcarboxylic acid amide as a main component represented by the formula: A liquid-absorbent resin composition comprising 10 to 100 parts by weight and an organic solvent. 2. The following general formula [1]: [Wherein R ₁ and R ₂ independently represent hydrogen or a methyl group, or R ₁ and R ₂ are bonded to each other to represent an alkylene group having 3 to 4 carbon atoms. And an adhesive resin comprising a synthetic resin or a synthetic rubber, and 100 parts by weight of an N-vinylcarboxylic acid amide-based liquid-absorbent resin powder obtained from a monomer having N-vinylcarboxylic acid amide as a main component represented by the formula: An absorbent resin composition comprising 10 to 100 parts by weight, an organic solvent, and 0.1 to 5 parts by weight of an anionic or nonionic surfactant. 3. The liquid-absorbent resin composition according to claim 1 or 2 is coated on one or both sides of a woven or non-woven fabric made of a synthetic fiber so as to have a dry adhesion amount of 10 to 200 g / m ^2. Or a liquid absorbing sheet impregnated. 4. One or both sides of a synthetic resin film,
A liquid-absorbent film obtained by coating or impregnating the liquid-absorbent resin composition according to claim 1 or 2 so as to have a dry adhesion amount of 10 to 200 g / m ² . 5. The dry absorbent amount of the liquid-absorbent resin composition according to claim 1 or 2 to a yarn made of a synthetic film or a synthetic fiber long fiber is in a range of 0.1 to 10 g / m ^2. Absorbent yarn which is painted or impregnated as described above. 6. The liquid-absorbent resin composition according to claim 1 or 2, the liquid-absorbent sheet according to claim 3, the liquid-absorbent film according to claim 4, and the liquid-absorbent yarn according to claim 5. , A cable having at least one mounted thereon.