JPH07188643A - Water-stopping material - Google Patents

Abstract

PURPOSE:To obtain a water-stopping material excellent in moldability, processibility, water-stopping capability, etc., by using a polyalkylene oxide modification obtd. by reacting a polyalkylene oxide and a polyol with a polyisocyanate. CONSTITUTION:A polyalkylene oxide modification is obtd. by reacting a polyalkylene oxide (e.g. polyethylene or polypropylene oxide) and a polyol (e.g. ethylene or propylene glycol) with a polyisocyanate (e.g. 2,4-tolylene diisocyanate) pref. in an equivalent ratio of NCO group to OH group of 0.3-3. The modification is molded into a water-stopping material (e.g. a water-stopping tape for a telecommunication cable) having a high water-absorbing capacity even in sea water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof material. The water blocking material obtained by the present invention is processed into a water blocking tape for communication cables, a water blocking sheet for civil engineering and construction, a sheet for preventing dew condensation, a water blocking mat, etc., and is useful as a water blocking material.

[0002]

2. Description of the Related Art A conventional water-stopping material using a water-absorbing resin having a water-absorbing ability of several hundred times obtained by cross-linking a so-called acrylic acid salt is a water-absorbing resin that does not have thermoplasticity. It was not possible to process the resin itself into a film or sheet by melting it with heat.
Therefore, the water-absorbent resin is mixed with a resin having thermoplasticity, sandwiched in a paper or a water-permeable film, or the water-absorbent resin is dispersed in a binder such as an acrylic resin and then coated on the film. Was manufactured. Further, a water-absorbent resin obtained by crosslinking an acrylate shows a high water-absorbent property, but has a poor water-absorbent property with respect to ionic water such as seawater, and is sufficiently satisfactory as a water-stopping material. It wasn't something.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water blocking material having excellent properties such as easy molding and processing and having a large water absorbency against seawater.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, have obtained polyalkylene oxide-modified products obtained by reacting polyalkylene oxide and polyol with polyisocyanate. It has been found that the product has good thermoplasticity, can be easily formed into a film, a sheet, etc., has a large water absorption amount for ionized water such as seawater, and has excellent properties as a water-stopping material. Has been completed.

That is, according to the present invention, (1) a water blocking material comprising a modified polyalkylene oxide obtained by reacting a polyalkylene oxide and a polyol with a polyisocyanate, and (2) a polyalkylene oxide containing polyethylene oxide or polypropylene oxide. And at least one water-stopping material of the above (1) selected from the group consisting of ethylene oxide-propylene oxide copolymers, and (3) at least the polyol selected from the group consisting of ethylene glycol, propylene glycol and butanediol. In the case of reacting one kind of the water blocking material of the above (1) and (4) reacting the polyalkylene oxide and the polyol with the polyisocyanate, the polyisocyanate has a total of the terminal -OH groups of the polyalkylene oxide and the polyol. -NC In which the ratio of the number of groups (-NCO / -OH) to provide a water stopping material of the above (1) is in the range of 0.3 to 3.0. Hereinafter, the present invention will be described in detail.

The modified polyalkylene oxide used in the present invention can be usually obtained by dissolving polyalkylene oxide and polyol in an organic solvent and then reacting them with polyisocyanate. The water absorption capacity of the resin for pure water is usually 10 to 50 g per 1 g of the resin. This water absorption capacity does not decrease significantly even when the object of absorption is seawater.

Examples of the polyalkylene oxide used for producing the modified polyalkylene oxide include polyethylene oxide, polypropylene oxide, ethylene oxide-propylene oxide copolymer, and polybutylene oxide. These polyalkylene oxides can be used alone or in combination of two or more. Preferably, polyethylene oxide, polypropylene oxide, ethylene oxide-propylene oxide copolymer, or a mixture thereof is used.

The weight average molecular weight of the polyalkylene oxide is preferably in the range of 1,000 to 100,000. If the weight average molecular weight of the polyalkylene oxide is less than 1,000, the water absorption ability of the polyalkylene oxide modified product obtained by reacting with the polyisocyanate is lowered or the melt viscosity is extremely increased, and the processing temperature at the time of molding May have to be increased, which is not preferable. On the other hand, when the weight average molecular weight exceeds 100,000, the cross-linking density of the polyalkylene oxide-modified product becomes low and the thermoplasticity becomes poor. Therefore, even if the modified product is used for molding, a molded product having sufficient strength cannot be obtained.

During the crosslinking reaction, 1 is added to the polyalkylene oxide.
By adding a polyol containing two or more hydroxyl groups (-OH groups) per molecule, particularly a diol, and reacting it with a polyisocyanate, a polyalkylene oxide-modified product having a low melt viscosity can be obtained. By using this, moldability is improved. improves. Examples of the polyol that can be added include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3-butanediol, 2,3-butanediol,
1,4-butanediol, 1,5-pentanediol, hexylene glycol, octylene glycol, glyceryl monoacetate, glyceryl monobutyrate, 1,6
-Hexanediol, 1,9-nonanediol, bisphenol A and the like. Ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol and the like are preferably used, and particularly preferably ethylene glycol, propylene glycol and butanediol, or these A mixture is used. In some cases, it may be preferable to use a polyol containing 3 or more hydroxyl groups per molecule.

The polyisocyanate used for producing the modified polyalkylene oxide may be an organic compound having two or more isocyanate groups (--NCO groups) in the same molecule. Specific examples thereof include 4,4'-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate, 1,8-dimethylbenzol-2,4-diisocyanate and 2,4-tolylene diisocyanate (T
DI), a trimer of TDI, polymethylene polyphenyl isocyanate, a urethane isocyanate compound obtained by reacting a polyol such as trimethylolpropane with a molar number of diisocyanate corresponding to the number of active hydrogens, polyisocyanate adduct, and the like. To be Preferably 4,4'-diphenylmethane diisocyanate
(MDI), hexamethylene diisocyanate, 2,4-
Tolylene diisocyanate (TDI) or the like is used.

The ratio of the polyalkylene oxide and the polyol used in the present invention is preferably in the range of 0.1 to 100 mol of the polyol with respect to 1 mol of the polyalkylene oxide. If it is less than 0.1 mol, it may not exhibit preferable physical properties in terms of thermoplasticity, and if it is used in excess of 100 mol, the water-absorbing ability of the obtained polyalkylene oxide-modified product becomes small, so that the water-stopping material of the present invention is obtained. It will be unsuitable.

The proportion of polyisocyanate used is
Terminal hydroxyl groups of polyalkylene oxides and polyols
Isocyanate groups (--NCO) based on the total amount of (--OH groups)
The ratio of -NCO / -OH (hereinafter referred to as R value) is 0.3.
Used in the reaction in the range of ~ 3.0, preferably 0.4-2.0. If the R value is less than 0.3, the cross-linking density of the polyalkylene oxide-modified product will be low, a polyalkylene oxide-modified product having sufficient strength cannot be obtained as a water blocking material used in the present invention, and the R value of If it exceeds 3.0, on the contrary, the cross-linking density of the polyalkylene oxide-modified product becomes high, and only a poor thermoplasticity may be obtained,
Not preferable.

As a method for obtaining a polyalkylene oxide modified product by reacting polyalkylene oxide and polyol with polyisocyanate, as mentioned above, polyalkylene oxide and polyol are dissolved in a suitable solvent,
A method of reacting with polyisocyanate is generally used, but there is also a method of dispersing polyalkylene oxide or polyol in a solvent, or a method of reacting in powder or solid form. A suitable reaction temperature is usually 50 to 150 ° C. The reaction can be promoted by adding a small amount of triethylamine, triethanolamine, dibutyltin laurate, dibutyltin acetate, triethylenediamine or the like to this reaction system.

Using a polyalkylene oxide-modified product obtained by these methods to prepare a waterproof material, T-die,
It is formed into a film by a method such as inflation or casting, or formed into a sheet or other molded product. In this case, it is also possible to mix it with a thermoplastic resin or elastomer other than the modified polyalkylene oxide and mold it into a film or sheet to give a waterproof material. The thermoplastic resin used here includes polyolefin resin, polyamide resin, polyester resin and the like.

Specific examples of the polyolefin resin include polyethylene and polypropylene.
Examples of the polyamide resin include 6-nylon, 6,6-nylon, 6,10-nylon, 11-nylon and 12-nylon. Examples of the polyester resin include polyethylene terephthalate and polybutylene terephthalate. Other vinyl group-containing homopolymers such as polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl acetal, polystyrene, polyacrylic acid ester and polymethacrylic acid ester, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer Polymer, acrylonitrile, styrene-butadiene copolymer, acrylic rubber-acrylonitrile-styrene terpolymer, acrylonitrile-styrene-butadiene copolymer, chlorinated polyethylene-acrylonitrile-styrene graft polymer, chlorosulfonated polyethylene,
It is also possible to use a thermoplastic resin such as acrylonitrile-ethylene-ethylene propylene rubber terpolymer.

As the elastomer, natural rubber is used.
(NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), nitrile rubber
(NBR), ethylene propylene rubber (EPDM), fluororubber (FKM), chloroprene rubber (CR) and styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS), styrene / ethylene-butylene / styrene (SEBS) ), Thermoplastic elastomers such as styrene / ethylene-propylene / styrene (SEPS), and the like.

The mixing ratio of the above-mentioned thermoplastic resin or elastomer to the polyalkylene oxide-modified product varies depending on the kind of the water blocking material to be used, but the thermoplastic resin or elastomer is 0 to 100 parts by weight of the polyalkylene oxide-modified product. ~ 2000 parts by weight is typical. When it is used in an amount of more than 2000 parts by weight, the water-blocking ability of the molded product becomes insufficient, and it is not preferable as a water-blocking material.

When molding the water blocking material, it is possible to mix the thermoplastic resin and the elastomer with an inorganic or organic filler, a plasticizer, a lubricant, a colorant and the like.

It is also possible to mix an appropriate amount of a water-absorbent resin having a so-called water absorption capacity of several hundred times, such as an acrylic acid-based cross-linked product and a starch graft product.

Specific examples of the polyalkylene oxide-modified product obtained by reacting the polyalkylene oxide and the polyol of the present invention with polyisocyanate as a water blocking material will be described below. FIG. 1 shows a cable cross-sectional view when the modified polyalkylene oxide of the present invention is used in a communication cable, wherein 1 is a cable core made of a copper wire or an optical fiber and 2 is an intermediate protection for protecting the cable core. A layer, 3 is a water-absorbent resin layer formed by winding the polyalkylene oxide-modified product of the present invention in a tape shape and wound, and 4 is an outermost layer sheath. Even when a layer made of a water-absorbent resin is provided in the intermediate layer between the cable core and the outermost coating, the water-absorbent resin at the damaged portion of the cable swells due to sufficient absorption of water even when the cable is laid on the seabed. It becomes a form filled with, and it is possible to prevent subsequent intrusion of seawater.

FIG. 2 is a conceptual diagram when the modified polyalkylene oxide of the present invention is molded and used as a water blocking material between concrete walls. Since the water infiltration from the voids due to the fine irregularities on the surface of the concrete 5 is compensated for by the expansion of the polyalkylene oxide-modified product due to water absorption, it is possible to obtain an excellent water-stopping effect and sealing effect.

FIG. 3 is a conceptual diagram of a water-blocking sheet formed by sandwiching a sheet 8 obtained by molding the polyalkylene oxide-modified product of the present invention between resin sheets 7. Even if the resin sheet on the surface is damaged, the polyalkylene oxide-modified product sheet layer inside swells and the subsequent leakage of water can be prevented.

[0023]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Production Example 1 Polyethylene oxide was placed in a 2 liter separable flask equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer.
(Weight average molecular weight 20000) 200 g, toluene 110
After charging 0 ml, 4 times by distillation under normal pressure to remove water
00 ml of toluene was distilled off. Next, 6.2 g of 4,4'-diphenylmethane diisocyanate, 1.44 g of 1,4-butanediol and 0.046 g of triethylenediamine
Was added and reacted at 110 ° C. for 3 hours. afterwards,
350 ml of hexane was added and cooled to room temperature to obtain a resin precipitate. This precipitate was filtered under reduced pressure and dried under reduced pressure to give polyethylene oxide-modified powder 203 g
Got The polyethylene oxide-modified product thus obtained had a water absorption capacity for pure water of 32 g H ₂ O / g resin.

Production Example 2 Instead of polyethylene oxide, an ethylene oxide-propylene oxide copolymer (80% by weight of ethylene oxide, 20% by weight of propylene oxide: weight average molecular weight 1)
Modified product 20 of ethylene oxide-propylene oxide copolymer was prepared in the same manner as in Production Example 1 except that
1 g was obtained. The water absorption capacity of the obtained resin for pure water is 26 g.
It was H ₂ O / g resin.

Production Example 3 1,4-polypropylene oxide copolymer (weight average molecular weight 6000) was used in place of polyethylene oxide.
198 g of a polypropylene oxide-modified product was obtained in the same manner as in Production Example 1 except that propylene glycol was used instead of butanediol. The water absorption capacity of the obtained resin for pure water was 23 g H ₂ O / g resin.

Example 1 Using the polyethylene oxide-modified product obtained in Production Example 1, a film having a thickness of 70 μm was obtained by inflation. The water absorption capacity of this film was 30 g / g. The film thus obtained was cut into a width of 35 mm to prepare the waterproof cable shown in FIG.

Example 2 Using the modified ethylene oxide-propylene oxide copolymer obtained in Production Example 2, a film having a thickness of 80 μm was obtained by inflation. The water absorption capacity of this film was 25 g / g. The film thus obtained was cut into a width of 35 mm to prepare the waterproof cable shown in FIG.

Example 3 Using the polypropylene oxide modified product obtained in Production Example 3,
A sheet having a thickness of 10 mm was obtained by hot pressing. The water absorption capacity of this sheet was 23 g / g. The sheet thus obtained was used as the water-swellable waterproof material shown in FIG.

Example 4 Using the polyethylene oxide-modified product obtained in Production Example 1, a sheet having a thickness of 12 mm was obtained by hot pressing. The water absorption capacity of this sheet was 31 g / g. The sheet thus obtained was used as the water-blocking sheet material shown in FIG.

Example 5 100 parts by weight of chloroprene rubber, 0.5 part by weight of stearic acid, 2 parts by weight of an antioxidant (2,2'-methylenebis (4-methyl-6-tert-butylphenol), 5 parts by weight of zinc white) , 29 parts by weight of carbon black, 4 parts by weight of magnesium oxide, and 30 parts by weight of the polyethylene oxide modified product obtained in Production Example 1 were mixed with a Banbury mixer, and then a hot press was applied to obtain a water absorbing sheet having a thickness of 10 mm. The water absorption capacity was 3 g / g, and this sheet was used as a water absorbing sheet for water shielding.

Test Example 1 The water blocking sheet obtained in Example 3 was sandwiched between two concrete test blocks (thickness 3 cm), and water was sprayed from the upper part of the test blocks. Although the entire upper block was wet, the lower block was prevented from permeating water due to the effect of the water blocking sheet.

[0032]

According to the present invention, it is possible to obtain a water-stopping material that is easy to mold and process and has a large water-absorbing ability even in seawater. The water blocking material obtained by the present invention is used as a water blocking material for communication cables, a water blocking sheet for civil engineering and construction, a sheet for preventing dew condensation, a water blocking mat, and the like.

[Brief description of drawings]

FIG. 1 is a cable cross-sectional view when a polyalkylene oxide-modified product of the present invention is used in a communication cable.

FIG. 2 is a conceptual diagram when the modified polyalkylene oxide of the present invention is molded and used as a water blocking material between concrete walls.

FIG. 3 is a conceptual diagram of a water-impermeable sheet formed by sandwiching sheets obtained by molding the polyalkylene oxide-modified product of the present invention between resin sheets.

[Explanation of symbols]

1: Cable core made of copper wire or optical fiber,
2: intermediate protective layer for protecting the cable core, 3: a layer formed by winding a polyalkylene oxide-modified product in a tape shape and wound, 4: outermost layer sheath, 5: concrete, 6: polyalkylene oxide-modified product molded product, 7: Resin sheet, 8:
Polyalkylene oxide modified product sheet,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoyuki Hashimoto, No. 1 Irifune Town, Shirima-ku, Himeji City, Hyogo Prefecture Sumitomo Seika Chemical Co., Ltd.

Claims (4)

[Claims] 1. A water blocking material comprising a polyalkylene oxide modified product obtained by reacting a polyalkylene oxide and a polyol with a polyisocyanate. 2. The water blocking material according to claim 1, wherein the polyalkylene oxide is at least one selected from the group consisting of polyethylene oxide, polypropylene oxide, and ethylene oxide-propylene oxide copolymer. 3. The water blocking material according to claim 1, wherein the polyol is at least one selected from the group consisting of ethylene glycol, propylene glycol and butanediol. 4. When reacting a polyalkylene oxide and a polyol with a polyisocyanate, a ratio of the number of —NCO groups contained in the polyisocyanate to the total number of terminal —OH groups contained in the polyalkylene oxide and the polyol.
The water-blocking material according to claim 1, wherein (-NCO / -OH) is in the range of 0.3 to 3.0.