JP2628422B2 - Water stopping material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water stopping material.
More specifically, the present invention relates to a water-stopping material useful for preventing water from flowing into an optical fiber cable or an electric cable.

[0002]

2. Description of the Related Art In recent years, the number of cases where optical fiber cables and electric cables are buried underground is increasing, and high water running prevention performance is required. Conventionally, as a method of preventing water running in these cables, a method of filling a cable with a jelly-like material, a method of filling a space between cables with a water-absorbing resin powder such as a partially crosslinked polyacrylate, a method of absorbing water, A method in which a resin held on a substrate with a water-soluble solvent-type adhesive is used as a water-stopping agent [Japanese Patent Application Laid-Open No. 2-3]
No. 3116], and a method of using a water-absorbing resin fixed to a base material with a rubber binder as a water-stopping agent [JP-A-3-31390].

[0003]

However, in the method of filling the jelly-like material or the method of filling the powder of the water-absorbing resin, the filling material easily falls off at the time of connecting the cable.
There is a disadvantage that workability is poor. In the method using a water-absorbent resin held on a substrate using a water-soluble solvent-type adhesive or a rubber-based binder, a film of the water-soluble resin or the rubber-based binder is formed on the surface of the water-absorbent resin. However, this inhibits the water absorption of the water-absorbing resin, so that there is a problem that sufficient water stopping performance cannot be obtained.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to obtain a water-stopping material in which the above-mentioned problems have been improved, and have reached the present invention. That is, the present invention is the following water-stopping material and optical fiber cable.

Water-stopping material In a water-stopping material having a water-absorbing film formed on a supporting substrate, the water-absorbing film is formed of the following vinyl resin (A), water-absorbing resin (B), and other A water-stopping material, characterized in that the coating is formed by applying a coating comprising the film-forming resin (C) on the supporting substrate. Vinyl resin (A): a vinyl monomer having an alkoxysilyl group (a) and a vinyl monomer having an anionic and / or nonionic hydrophilic group (b) as copolymerization components, Based on the weight, (a) is 0.01 to 60
%, (B) a vinyl resin containing 40 to 99.99% as a constituent unit. An optical fiber cable comprising the water-stopping material according to the above item interposed between the cable jacket and the optical fiber.

In the present invention, the vinyl resin (A)
Is a copolymerizable component comprising a vinyl thread monomer (a) having an alkoxysilyl group, which is a hydrolyzable group, and a vinyl monomer (b) containing an anionic and / or nonionic hydrophilic group. .

Examples of the vinyl monomer having an alkoxysilyl group (a) include vinylsilane having an alkoxysilyl group [vinylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane And a (meth) acryloxyalkylsilane having an alkoxysilyl group [γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyl Methyldiethoxysilane, γ-acryloxypropyltriethoxysilane, etc.].

The anionic and / or nonionic hydrophilic group-containing vinyl monomer (b) includes, for example, the following (1) to
(4). (1) unsaturated mono- or polycarboxylic acids: (meth) acrylic acid, crotonic acid, sorbic acid, maleic acid, itaconic acid, cinnamic acid, etc. (2) aliphatic or aromatic vinyl sulfonic acids: vinyl sulfonic acid, allyl Sulfonic acid, vinyltoluenesulfonic acid, styrenesulfonic acid, etc. (3) (meth) acrylsulfonic acid: (meth) sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, etc. (4) Polyoxyethylene group-containing vinyl monomer : (Where R = H or CH ₃ , m = 1-200, EO
Is an oxyethylene group, PO is an oxypropylene group, EO
/ PO> 2 (molar ratio), R ′ = C _{1 to} C ₁₀ alkyl group (1) to (4) are preferably (4). Two or more monomers (b) may be used in combination. If necessary, the vinyl resin (A) may be one obtained by using another vinyl monomer (c) together with (a) and (b) as a copolymer component. Examples of the monomer (c) include the following (5)
To (14). (5) alkyl (meth) acrylate (alkyl group having 1 to 20 carbon atoms) methyl (meth) acrylate,
Ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, etc. (6) Aromatic vinyl monomer styrene, α-methyl (7) Vinyl halide monomer: vinyl chloride, etc. (8) Alkyl or cycloalkyl vinyl ether: methyl vinyl ether, cyclohexyl vinyl ether, etc. (9) Vinyl ester: vinyl acetate, etc. (10) nitrile group Containing vinyl monomer: acrylonitrile, etc. (11) Amide group-containing vinyl monomer (meth) acrylamide, crotonamide, N-methylolacrylamide, fumaric diamide, etc. (12) Epoxy group-containing vinyl monomer: ( Glycidyl methacrylate) (13) Perfluoroalkyl group-containing (meth) acrylic acid esters such as vinyl-based monomer perfluorooctylethyl group having iodine-substituted alkyl group Tsu, C ₈ F ₁₇
(CH) ₁₁ OCOCH ＝ CHCOOCH ₃ or other perfluoroalkyl group-containing maleate, C ₇ F
₁₅ Vinyl ether containing perfluoroalkyl group such as CH ₂ OCH ＯCH ₂ etc. (14) Vinyl monomer containing polydimethylsiloxane group

The weight ratio of (A) and (B) constituting the vinyl resin (A) is such that (A) is usually 0.01 to 60%,
Preferably, it is 0.5 to 30%, and (b) is usually 40 to 99.
99%, preferably 70 to 99.5%. If (a) is less than 0.01%, the coatability of the resin composition will be poor, and the water absorption rate of the coating will be low. If it exceeds 60%, the water absorption rate of the coating will be low and will not withstand practical use. . Further, in addition to (b) and (b) used in this ratio, as necessary, other vinyl monomers (c) as described above
May be used as a copolymerization component.

As an example of the method for producing the vinyl resin (A), (A) can be obtained by radical polymerization of (A), (B) and, if necessary, (C) in the presence of a radical initiator in an organic solvent. Can be As the organic solvent, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, n-butyl acetate, cellosolve acetate, ethylene dichloride, or a mixture of two or more of these may be used. Organic solvent, (a), (b) and if necessary (c)
Is usually 0.2: 2 to 2: 1, preferably 0.5: 1 to 5: 1.

As the radical initiator, azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.) are preferably used. The amount of the radical initiator used is usually 0.001 to 20 with respect to the total weight of (a) and (b).
%, Preferably 0.1 to 10%. In some cases, a chain transfer agent (such as n-laurylmercaptan, n-dodecylmercaptan, mercaptopropionic acid, t-dodecylmercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane) may be used together with a radical initiator. In addition, the molecular weight can be adjusted. The reaction temperature of the radical polymerization reaction is usually 50 to 150 ° C, preferably 70 to 130 ° C.
The reaction time is generally 1 to 10 hours, preferably 2 to 7 hours.
Time. The end point of the polymerization can be confirmed by disappearance of the double bond absorption (1648 cm ^-1 ) in the infrared absorption spectrum or by reduction of unreacted monomers by gas chromatography. The resin produced by the polymerization reaction is obtained in a state of being dissolved or precipitated in an organic solvent. This resin can be isolated by a method such as removal of the solvent by evaporation, filtration, washing and drying, if necessary.

Although the molecular weight of the vinyl resin (A) is not particularly limited, it is generally 1,000 to 100,000, preferably 3,000 to 60,000. (A) forms a network at room temperature when exposed to the atmosphere and hardens.

The water-absorbing resin (B) is, for example, one selected from starch or cellulose (a) and a water-soluble monomer having a carboxyl group or a sulfonic acid group or a monomer which becomes water-soluble by hydrolysis. The above monomer (b)
And a cross-linking agent (c) as an essential component, and a water-absorbent resin obtained by hydrolysis as required. Used in the production of the water absorbent resin exemplified above
(a), details of (b) and (c), proportions of (a), (b) and (c),
Specific examples of the production method and the water-absorbing resin are JP-A-52-25886,
JP-B-53-46199, JP-B-53-46200 and JP-B-55-2
No. 1041.

Examples of the water-absorbing resin other than those exemplified above include those obtained by polymerizing (a) and (b) and hydrolyzing them (hydrolyzate of starch-acrylonitrile graft polymer, cellulose-acrylonitrile graft polymer). Crosslinked product of (a) (crosslinked product of carboxymethylcellulose); a copolymer of (b) and (c) hydrolyzed as necessary (partially hydrolyzed product of crosslinked polyacrylamide) Crosslinked acrylic acid-acrylamide copolymer, crosslinked sulfonated polystyrene, saponified vinyl ester-unsaturated carboxylic acid copolymer described in JP-A-52-14689 and JP-A-52-27455, Crosslinked polyacrylates, crosslinked acrylic acid-acrylate copolymers, crosslinked isobutylene-maleic anhydride copolymers, and crosslinked Carboxylic acid-modified polyvinyl alcohol); and polymers (b) of those having self-crosslinking properties (such as self-crosslinked polyacrylates). Further, two or more of the above-described water-absorbing resins may be used in combination.

Among the water-absorbing resins exemplified as (B), preferred are, and among those exemplified above, partially hydrolyzed crosslinked polyacrylamide;
Cross-linked acrylic acid-acrylamide copolymer, cross-linked polyacrylic acid (salt), cross-linked acrylic acid-acrylate copolymer, cross-linked isobutylene-
A maleic anhydride copolymer and a crosslinked carboxylic acid-modified polyvinyl alcohol.

The water absorption performance of (B) with respect to pure water is usually 50
ml / g or more, preferably 100 to 1,000 ml / g.

In the present invention, the weight ratio of the resin (A) having a silyl group to the water-absorbent resin (B) in the coating is usually (0.1 to 30) :( 5 to 99.0), preferably (0.5-20): (10-80). When (A) is less than 0.1, the film-forming property at the time of application becomes insufficient, and when it exceeds 30, the water absorption of the film becomes low.

If necessary, the coating may further contain other film-forming resin (C) and various additives (a surfactant, a penetrant, a catalyst for hydrolyzing silyl groups, etc.). Examples of other film-forming resins (C) include various resins commonly used as paints and coating materials. For example, lacquer-based, acrylic lacquer-based, thermosetting acrylic-based, alkyd yarn, melamine-based, epoxy-based, urethane-based, ester-based, silicone-based, and fluorine-based resins can be used. When these other film-forming resins (C) are used, preferred are urethane resins and acrylic resins.

In the present invention, examples of the support substrate include paper, nonwoven fabric, plastic sheet, thread, string, and yarn. Among these, preferred are nonwoven fabrics made of polyester-based synthetic fibers, polypropylene-based synthetic fibers, acrylic-based synthetic fibers, and the like.

The proportion of each component in the paint is usually as follows on a weight basis.

An example of the method for producing the water-stopping material of the present invention is as follows.
The water-stopping material of the present invention can be obtained by applying a coating containing each of the above components on a substrate, drying and curing. As a method for producing the coating, a suitable solvent is added to each of the above-mentioned components, and an ordinary stirring and mixing or mixing apparatus (ball mill, kneader,
It is obtained by dispersing and mixing using a sand grinder, a roll mill, a flatstone mill and the like, and further, if necessary, cross-linking the hydrolyzable silyl groups of the silyl group-containing resin (A) with each other. This crosslinking is preferred because the water absorption rate and the temporal stability of the paint and the applied film are improved. Alternatively, the crosslinking may be performed after the coating material is applied on the substrate. Examples of the method of crosslinking the hydrolyzable silyl group include heating of a paint or a coating film and addition of a catalyst to the paint. The heating conditions are usually 40 ° C to 120 ° C, preferably 60 ° C to 80 ° C. Examples of the catalyst include acids such as hydrochloric acid, sulfuric acid, acetic acid, and phosphoric acid, alkalis such as sodium hydroxide and potassium hydroxide, and dibutyltin dialkylates such as dibutyltin dibutylate and dibutyltin dilaurate. As a method of applying the paint on the substrate, the paint is diluted with an appropriate solvent as needed to adjust the viscosity, for example, a blade coater, an air knife coater, a roll coater, a curtain coater, a bar coater, a gravure coater, or any other method. The coating is applied to at least one surface of the base material at a rate of about 5 to 200 g / m ² (solid content). Then, the coating is obtained by drying at room temperature or by heating. When heating, the temperature is usually 40-180
° C, preferably 60 to 150 ° C. Examples of the solvent used for the components of the paint or for dilution include heptane, hexane, cyclohexane, toluene, xylene, methanol, propanol, acetone, butanone, dimethylformamide, and methyl cellosolve.

The optical fiber cable of the present invention comprises the water-stopping material of the present invention interposed between the cable jacket and the optical fiber, and will be described below with reference to the drawings showing an example thereof. I do. FIG. 1 is a cross-sectional view of a slot type optical fiber cable for preventing water running according to the present invention. This cable has a tension member 4 as a core in the center.
A slot-type spacer 5 having a slot provided therearound; an optical fiber 2 laid in the slot; a water-stopping material 1 of the present invention provided around the slot-type spacer 5; Consists of three. The water-stopping material 1 is in the form of a tape and is wound around the slot-type spacer 5 so that the coating surface faces downward (inside). In the case of a large-sized optical fiber cable, the cable as illustrated in FIG. 1 is further bundled into a plurality of bundles, the outside of which is further wrapped around with a tape-shaped water-stopping material of the present invention, and a cable. What is necessary is just to make the double structure wrapped in the jacket. Further, in this case, a PP yarn may be used as a base material between a plurality of bundles, and the water-stopping material of the present invention having the water-absorbing coating formed on the base material may be interposed.

[0023]

According to the optical fiber cable of the present invention having a structure as exemplified in FIG. 1, when water enters due to the occurrence of cracks in the jacket, the water-absorbing resin in the coating film on the surface of the water-stopping material of the present invention is reduced. It can quickly absorb water and swell and fall out of the coating film, and can quickly fill gaps in the slots to prevent water running.

[0024]

The present invention will be further described with reference to the following examples.
The present invention is not limited to this. Hereinafter,% represents% by weight. Production Example 1 100 g of isopropanol was charged into a 300 ml four-necked kolben, and heated to 83 ° C. with stirring. 80 g of an ethylene oxide 8 mol adduct of 2-hydroxyethyl methacrylate, 1 g of γ-methacryloxypropyltrimethoxysilane, 2-hydroxyethyl methacrylate 19
A mixed solution of 2 g of g, n-laurylmercaptan and 2 g of azobisisovaleronitrile (hereinafter referred to as AIVN) was added dropwise over 3 hours. After reacting at the same temperature for 2 hours,
0.2 g of AIVN was added, and the mixture was further reacted for 2 hours. Thus, a copolymer A of a 50% solution of isopropanol was obtained.

Production Example 2 73 g of methacrylic acid ester of 9 mol of ethylene oxide adduct of methanol, 5 g of γ-methacryloxypropyltrimethoxysilane, 22 g of 2-hydroxyethyl acrylate, 1 g of n-laurylmercaptan, AIV
Polymerization was carried out in the same manner as in Production Example 1 using N2 g to obtain a copolymer B of a 50% solution of methyl ethyl ketone (hereinafter referred to as MEK).

Production Example 3 Ethylene oxide 12 of 2-hydroxyethyl methacrylate
50 g of molar adduct, 10 g of acrylic acid, 30 g of methyl methacrylate, 10 g of γ-methacryloxypropyltrimethoxysilane, 1 g of n-lauryl mercaptan, A
Polymerization was carried out in the same manner as in Production Example 1 using 2 g of IVN to obtain a copolymer C of a 50% solution of n-butyl acetate.

Production Example 4 80 g of n-butyl acetate was charged into a 300 ml four-necked kolben and heated to 110 ° C., and 20 g of xylene, 53.7 g of methyl methacrylate, and 31 g of n-butyl acrylate were used.
g, 15 g of 2-hydroxyethyl methacrylate, 0.3 g of methacrylic acid, 1.7 g of azobisisobutyronitrile
Was added dropwise over 3 hours, and then reacted for 7 hours. An acrylic film-forming polymer D having a molecular weight of 10,000 was obtained.

Examples 1 to 5 and Comparative Examples 1 and 2 Each component was blended as shown in Table 1 and mixed by heating at 70 ° C. for 3 hours to obtain each paint. This was applied to a polyester-based nonwoven fabric (basis weight 90 g / m ² ) with a bar coater and dried at 105 ° C. for 3 minutes to obtain a test sample having a coating with a solid content of 100 g / m ² . Table 2 shows the physical property test examples.

[0029]

[Table 1]

Note) Sunwet IM-5000MPS: Water-absorbent resin manufactured by Sanyo Chemical Industries, Ltd. Na acrylate partially crosslinked water-absorbent resin (powder) Samprene IB-1700D: Resin for urethane-based paint manufactured by Sanyo Chemical Industries, Ltd. Polyester urethane resin 30% solids, solvent MEK

[0031]

[Table 2]

Note) Measurement method 1) Water absorption rate (sec) A test sample cut into a size of 10 cm × 10 cm was placed on a horizontal table with the coated surface facing upward, and 1 ml of the sample was placed almost at the center of the sample from above. The artificial seawater [Aquamarine; manufactured by Yasu Yakuhin Co., Ltd.] was dropped with a pipette, and the time until the entire amount of the artificial seawater was absorbed was measured. 2) Water absorption 10cm in nylon net bag (250 mesh)
A sample piece cut into a size of 10 cm was put therein, and this bag was immersed together with the bag in artificial seawater. One hour later, the bag was lifted up into the air, allowed to stand, drained for 15 minutes by gravity, and then weighed to determine the amount of water absorption. (The same operation as above was performed using only the net bag, and the weight was subtracted as a blank.) 3) Coating property: The adhesion between the nonwoven fabric and the coating film was good and the coating surface was smooth. . ×: The adhesiveness between the nonwoven fabric and the coating film is poor, and the coating surface has many irregularities.

[0033]

(1) The water-stopping material of the present invention has a very high water absorption rate and water absorption when it comes into contact with water. (2) Since the water-stopping material of the present invention has good adhesiveness between the base material and the coating film, when used for an optical fiber cable or an electric cable, the coating film does not peel off at the time of work and is excellent in workability. (3) An optical fiber cable or an electric cable using the water-stopping material of the present invention is excellent in water running prevention. Due to the above effects, the water stopping material of the present invention is useful as a water stopping material for cables such as optical fiber cables.

[Brief description of the drawings]

FIG. 1 is a sectional view of a slot-type water-running-preventive optical fiber cable showing an example of use of a water-stopping material of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Water-stop material of this invention 2 Optical fiber 3 Jacket 4 Tension member 5 Slot type spacer

 ──────────────────────────────────────────────────続 き Continuation of the front page Judge of the collaborative body Kyoko Yoshimi Judge Judge Taniguchi Judge Shunichi Yokoo (56) References JP-A-64-6042 (JP, A) JP-A 64-85210 (JP, A) JP JP-A-3-115479 (JP, A) JP-A-52-65529 (JP, A) JP-A-1-207375 (JP, A)

Claims (5)

(57) [Claims] 1. A water-stopping material having a water-absorbing film formed on a supporting substrate, wherein the water-absorbing film is the following vinyl resin (A), water-absorbing resin (B), and optionally another film. A water-stopping material, which is a coating formed by applying a coating material comprising a forming resin (C) on a supporting substrate. Vinyl resin (A): a vinyl monomer having an alkoxysilyl group (a) and a vinyl monomer having an anionic and / or nonionic hydrophilic group (b) as copolymerization components, Based on the weight, (a) is 0.01 to 60
%, (B) a vinyl resin containing 40 to 99.99% as a structural unit 2. The water-stopping material according to claim 1, wherein (b) is a polyoxyethylene group-containing vinyl monomer. 3. The (A) :( B):
The weight ratio of (C) is (0.5-20) :( 10-8
0): The water stopping material according to claim 1 or 2, wherein (0 to 20). 4. The water stopping material according to claim 1, wherein the alkoxysilyl group in (A) constituting the water-absorbing coating forms a network structure and is hardened. 5. An optical fiber cable in which the water stopping material according to claim 1 is interposed between a cable jacket and an optical fiber.