JPH01129086A - Water-proofing tape - Google Patents

Abstract

PURPOSE:To provide a water-proofing tape having such a high swelling speed upon contact with an aqueous liquid as to be able to instantaneously stop the aqueous liquid entering into a gap, by fixing water-absorbent resin particles on a film or sheet by using a specific urethane-modified polymer. CONSTITUTION:A water-soluble polyalkylene oxide (a) having an average MW of at least 50000 (e.g., polyethylene oxide having an average MW of 50000-2000000) is reacted with an isocyanate compd. (b) (e.g., 2,4-tolylene diisocyanate) at 40-160 deg.C to prepare a urethane-modified polymer (B). 100 pts.wt. water-absorbent resin particles (A) having an average size of at most 200mu (e.g., crosslinked polyacrylic acid salt particles) are mixed with 5-1000 pts.wt. component B as an org. polymer binder to prepare a mixture, which is then applied on the surface of a film or sheet such as a plastic sheet, a metallic foil, a (non)-woven fabric made of fibers, or paper to form a coating film having a thickness of 30-300mu.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water-stop tape that is used by filling gaps in order to prevent aqueous liquid from entering through the gaps. More specifically, by increasing the rate of swelling of the water-stopping tape when it comes into contact with an aqueous liquid, the aqueous liquid can quickly be prevented from penetrating through the gap and can penetrate deep into the gap or pass through the gap. The present invention relates to a water-stop tape that can completely prevent the infiltration of water.

(Prior Art) A method has been proposed in which a water-swellable water stop tape is filled into a gap in order to prevent aqueous liquid from entering the gap. As such a water stop tape, one in which a film or sheet is coated with a water-absorbing resin using an organic polymer binder such as polyester, polyamide, polyurethane, or polyacrylic acid ester has been proposed.

However, in the water-stop tape obtained by this method, the binder used itself inhibits the water-swelling property of the water-absorbing resin, so the swelling rate becomes low when it comes into contact with an aqueous liquid, and therefore, the water-stopping tape that is obtained by this method has a low swelling rate when it comes in contact with an aqueous liquid. There is a problem in that it takes a long time to completely stop the aqueous liquid, and the aqueous liquid infiltrates from the infiltration part over a long distance, for example, deep into the gap or through the gap.

(Problem that the invention attempts to solve) The present invention solves the above problems.

Therefore, an object of the present invention is to provide a water-stopping tape that quickly stops water even if an aqueous liquid enters the gap and prevents the water from penetrating into the deep part of the gap R or through the gap.

(Means and effects for solving the problems) The present invention has the following features:
In a water-stop tape formed by fixing a water-absorbing resin onto the surface of a film or sheet using an organic polymer binder, a water-soluble polyalkylene oxide with an average molecular weight of 50,000 or more is reacted with an isocyanate compound as the organic polymer binder. The present invention relates to a water-stop tape characterized by using a urethane compound obtained by

The average molecular weight of the water-soluble polyalkylene oxide used in the present invention is 50,000 or more. If it is less than 50,000, the swelling rate of the obtained water stop tape when it comes into contact with an aqueous liquid will be low, and a sufficient water stop effect will not be exhibited. In addition, as the polyalkylene oxide in the present invention, water-soluble polyethylene oxide or a copolymer of fullylene oxide such as bu-O-pyrene oxide can be used within a range that does not impair its water solubility.
Polyethylene oxide having a molecular weight of 10,000 to 2,000,000 is preferred.

The isocyanate compound used in the present invention includes -
A compound containing one or two or more isocyanate groups in the molecule, such as 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, 1-methylbenzene-2,4°6-triisocyanate. , naphthalene-1,3゜7-triisocyanate, biphenyl-2,4゜4'-triisocyanate, 1,3-dimethylbenzene-2,4-diisocyanate, phenylene diisocyanate, n-propylisocyanate, n-butyl isocyanate, n-hexyl isocyanate, octadecyl incyanate, cyclohexyl isocyanate, benzyl isocyanate, phenyl isocyanate, propane diisocyanate, hexyl isocyanate, decane diisocyanate, Coronate 0L, Coronate 08L (manufactured by Nippon Polyurethane Kogyo@), Sumidur ON, Sumidur @L, etc. Sumidur [phase] H
These isocyanate compounds can be used even if they are masked with a suitable masking agent. can.

In order to obtain a urethane compound by reacting a polyalkylene oxide and an isocyanate compound, these raw material compounds may be maintained at a temperature of 40 to 160°C using water or various organic solvents as a reaction solvent if necessary. This reaction is carried out according to a conventionally known urethanization reaction, but
The reaction can also be carried out in the presence of an amino compound such as triethylamine, tetraethyldiamine, triethylenediamine, etc.; a morpholine derivative: a piperazine derivative; a tin compound such as nidibutyltin dichloride, dilaurintin dichloride, etc. as a promoter.

The urethane compound thus obtained is used as an organic polymer binder for fixing the water-absorbing resin onto the surface of a film or sheet.

When using a urethane compound as a binder, various methods can be adopted. For example, a water-absorbing resin and other additives are mixed with the urethane compound obtained by the above reaction, and the resulting mixture is applied to the surface of a film or sheet. The coating method involves mixing polyalkylene oxide and isocyanate compounds, which are raw materials for urethane compounds, with water-absorbing resin and other additives, coating the resulting mixture on the surface of a film or sheet, and then applying the mixture at a temperature of 40 to 160°C. There is a method in which a urethane compound is produced on the surface of a sheet or film by holding the urethane on the surface of the sheet or film.

The urethane compound used as a binder in the present invention is preferably used in an amount of 5 to 1000 parts by weight based on 100 parts by weight of the water absorbent resin.

If it is less than the 5-stone part, the immobilization of the water-absorbing resin will be insufficient,
If it exceeds 1,000 parts by weight, the water swelling ratio of the resulting water stop tape may decrease, and a sufficient water stop effect may not be obtained.

The water-absorbing resin used in the present invention is not particularly limited, and includes, for example, a hydrolyzate of starch-acrylonitrile graft polymer, a neutralized product of starch-acrylic acid graft polymer, and an acrylic ester-vinyl acetate copolymer. Examples include saponified products, crosslinked polyvinyl alcohol modified products, crosslinked polyacrylates, crosslinked inbutylene-maleic anhydride copolymers, and crosslinked polymers of sulfone l [containing monomers]. Among these, crosslinked polyacrylates are particularly preferred because they have excellent gel strength, and crosslinked polymers of sulfonic acid group-containing monomers are particularly preferred because they have excellent salt resistance.

In addition, the average particle diameter of the water absorbent resin used in the present invention is
There are no particular restrictions, but 2
It is preferable that it is 00μ or less.

In the present invention, it is possible to add an inorganic powder in order to significantly improve the water swelling rate. Examples of inorganic powders include silica, alumina, synthetic silicates, magnesium carbonate, magnesium silicate, calcium carbonate, bentonite, kaolinite, carbon black, zeolite, calcium carbonate, activated clay, titanium oxide, and mixtures thereof. Can be mentioned. Among these, ultrafine silica particles such as Aerosil (manufactured by Nippon Aerosil Co., Ltd.) are particularly preferred because they have a small particle size and are excellent in adsorption to water-absorbing resins.

In the present invention, in order to fix the water-absorbing resin onto the surface of a film or sheet using a Ti polymer binder, it is necessary to apply and spread a composition containing the water-absorbing resin onto the surface of the film or sheet. In order to improve the workability, various additives such as a solvent for adjusting the viscosity of the composition, a thickener, a dispersant, etc. can be added.

The solvent for viscosity adjustment is used as a reaction solvent between the polyalkylene oxide and the isocyanate compound, and may be blended in advance into the composition (or may be added at the time of application.Such solvents include nitromethane, , acetonitrile, benzene, toluene, xylene, dimethylformamide, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, dioxane, diethyl ether, ethylene dichloride, carbon tetrachloride, chloroform, ethyl acetate, methyl isobutyl ketone, acetone, water, etc. Mention may be made of mixtures of.

The film or sheet used in the present invention is not particularly limited, but includes, for example, plastic sheets such as polyester, polyvinyl chloride, polyethylene, polypropylene, polycarbonate, and cellophane.

In the present invention, there are no particular limitations on the thickness of the composition applied onto the surface of the film or sheet.

30-300 in terms of handling and water-stopping properties of water-stop tape
It is preferably in the range of μ. Further, the surface to be coated may be one or both sides of the film or sheet.

(Effects of the Invention) Since the water stop tape of the present invention has a very high swelling rate when it comes into contact with an aqueous liquid, it can instantly stop the aqueous liquid that has entered through the gap.

Therefore, by filling the gap with the water stop tape of the present invention, it is possible to completely prevent aqueous liquid from penetrating into the deep part of the gap or through the gap. You can get a water effect.

Therefore, the water stop tape of the present invention can be effectively used as a seal material or water stop material for civil engineering and industrial use, and a water stop material for optical and electrical cables.

(Examples) Hereinafter, the present invention will be explained in detail with reference to Examples, but the scope of the present invention is not limited only to these Examples. All parts in the examples represent parts by weight.

Reference Example 1 21.6 g of sodium salt of 2-sulfoethyl methacrylate (0,
10 mol), methacrylic acid 21.5 g (0.25 mol), sodium methacrylate 70.2 g (0.65 mol), N,N-methylenebisacrylamide 0.92 g
(0,006 mol) and 170 g of water were charged and stirred to uniformly dissolve the mixture.

After purging with nitrogen, the mixture was heated to 40° C. in a hot water bath, 1.0 g of a 10% aqueous ammonium persulfate solution and 0.5 g of a 1% aqueous L-ascorbic acid solution were added, and stirring was stopped to allow polymerization. After the start of polymerization, heat was generated, and the temperature rose to 95°C after 30 minutes. After confirming that the temperature of the combination system had started to drop, the water bath was raised to 90°C and heated for an additional hour. The obtained hydrogel of the crosslinked polymer was divided into small pieces, dried in a hot air dryer at 150° C. for 3 hours, and then ground in a hammer-type grinder.

The obtained powder of the crosslinked polymer was classified to obtain a material that passed through a 150 mesh standard sieve (hereinafter referred to as water absorbent resin (1)).

Reference example 2 Sodium acrylate 74.95 mol%, acrylic acid 2
40 of an acrylate monomer consisting of 5 mol% and 0.05 mol% of trimethylolpropane triacrylate.
% aqueous solution was polymerized by standing at 50 to 80° C. in a nitrogen atmosphere using 0.05 g of ammonium persulfate and sodium bisulfite o, oig to obtain a gel-like hydropolymer. This gel-like hydropolymer was dried in a hot air dryer at 180° C., and then pulverized using a hammer-type pulverizer and a jet pulverizer.

The obtained polymer powder was classified to obtain a material that passed through a 400 mesh standard sieve (hereinafter referred to as water absorbent resin (2)).

Example 1 After adding and dissolving 30 parts of polyethylene oxide with an average molecular weight of 100,000 and 0.01 part of dibutyltin dichloride in 370 parts of nitromethane, 100 parts of the water absorbent resin (1) obtained in Reference Example 1 was added thereto. , Sumidur 0N-7
A coating composition was prepared by adding 0.5 parts of Aerosil 0R972 (manufactured by Nippon Aerosil ■, hydrophobic ultrafine particulate silica).

This composition was coated on both sides of a 25μ thick polyester film with a bar coater so that each side had a thickness of 120μ, and then heated at 80°C for 10 minutes to obtain the water stop tape (1) of the present invention. Ta.

Example 2 30 parts of polyethylene oxide with an average molecular weight of 800,000 and 0.05 part of triethylenediamine were mixed with 4 parts of acetonitrile.
70 parts and dissolved therein, 0.1 part of 2,4-tolylene diisocyanate was added thereto, and the mixture was heated at 70°C in a nitrogen stream for 50 minutes.
The reaction was carried out for a period of time to obtain an acetonitrile solution of the urethane compound. Water absorbent resin (2) 1 obtained in Reference Example 2 was added to this solution.
00 parts was added to prepare a coating composition.

This composition was applied to the surface of a polyester film in the same manner as in Example 1, and then dried.
) was obtained.

Comparative Example 1 A comparative water-stop tape (1) was obtained in the same manner as in Example 2 except that 30 parts of polyethylene glycol having an average molecular weight of 10,000 was used instead of the polyethylene oxide having an average molecular chain of 800,000 in Example 2. .

Examples 3 to 4 and Comparative Example 2 Water stop tapes (1) to (1) of the present invention obtained in Examples 1 to 2
2) and the comparative water stop tape (1) obtained in Comparative Example 1 were each wrapped in a single layer around a glass rod having a diameter of 13.51 M and a length of 2000 m. Next, a glass rod wrapped with water-stopping tape was inserted into a glass tube with an inner diameter of 15#ll11 and a length of 2000#III so that the gap was uniform to create a mock cable for evaluating the waterstopping effect.

This simulated cable was held horizontally, and a container filled with 141 tap water was connected to one end of the simulated cable using a rubber tube, and the liquid level in the container was maintained at a height of 1000# above the simulated cable. Next, open the cock at the bottom of the container and guide the tap water into the simulated cable. The evaluation was made by measuring 1 hour after the introduction. The results are shown in Table 1.

Table 1 (Note) Tap water was leaking from the other end of the simulated cable where the rubber tube was not connected.

Claims (1)

[Claims] 1. In a water-stop tape formed by fixing a water-absorbing resin onto the surface of a film or sheet using an organic polymer binder, a water-soluble polyalkylene oxide with an average molecular weight of 50,000 or more and an isocyanate compound are used as the organic polymer binder. A water-stop tape characterized by using a urethane compound obtained by reacting.