JP3217769B2 - Water stopping material and water stopping method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water stopping material and a water stopping method. More specifically, a waterproof material which is suitable as a waterproof material in civil engineering, construction and other various fields, is easier to crush than conventional materials, and maintains a good airtight waterproofing effect over a long period of time, and a waterproof material is used. It relates to the method of stopping water.

[0002]

2. Description of the Related Art In a shield construction method for constructing a tunnel by combining segments, which are constituent units of a tunnel, a sealing material for a tenoned segment having unevenness on a combination surface of the segment requires a lower compressive stress during the construction of the segment. Is required. this is,
While ordinary segments fix the segments by bolt fastening, the tenoned segments fix the segments by a combination of irregularities, so the method of fastening the segments is simplified, the fastening force is low, This is because a force for strongly crushing the sealing material cannot be expected. It is difficult for a non-foaming type water-swellable rubber to meet such a demand for low compressive stress. Conventionally, a water-stopping material made by foaming a water-swellable rubber has been known to meet such a demand for a low compressive stress (for example, see JP-A-57-9203).
No. 2, Japanese Patent Application Laid-Open No. 08-121600,
8-157805, JP-A-09-111899). These water-swellable foamed water-stopping materials are obtained by kneading a highly water-absorbent resin and a foaming agent into an unvulcanized rubber and vulcanizing and molding.

[0003]

However, since these foamed water-stopping materials have a large specific surface area, the kneaded superabsorbent resin easily falls off from the base rubber, and it is difficult to maintain the water-absorbing performance for a long period of time. There was a problem.

[0004]

Means for Solving the Problems The present inventors have improved the above-mentioned problems of the conventional water-swellable foamed water-stopping material, have a small mass reduction rate, can maintain the swelling performance due to water absorption for a long time, As a result of intensive studies on the waterproof material with compressive stress,
The present invention has been reached.

That is, the present invention relates to a water-stopping material comprising a polyurethane foam, wherein the polyurethane foam comprises:
It has a density of 0.3 to 0.9 g / cm ³ and a volume expansion ratio of 1.2 to 8 times, and is immersed in water at 70 ° C. for 7 days and in water at 23 ° C. for 180 days. A waterproof material that is an oxyethylene group-containing polyurethane foam having a reduction rate of 3% or less and that is a molded product or a molded product; and a combined surface of segments in a shield method in which a tunnel is constructed by combining segments. A water stopping method using the water stopping material described above.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The water-stopping material of the present invention is a water-stopping material comprising a molded article or a molded article of an oxyethylene group-containing polyurethane foam. The polyurethane resin itself swells upon absorbing water. It does not contain any swelling component that elutes into the water, and therefore has a small mass reduction rate and exhibits stable swelling performance over a long period of time.

The oxyethylene group-containing polyurethane foam used for the water-stopping material of the present invention usually has a density of 0.3 to 0.3.
9 g / cm ³ , preferably 0.45 to 0.75 g / cm
³ If the density is less than 0.3 g / cm ³ , the partition walls of the bubbles become thin, so that the bubbles are destroyed by the initial compressive stress at the time of segment construction, and good stress relaxation characteristics cannot be obtained. When it exceeds 0.9 g / cm ³ , the effect of reducing the compressive stress at the time of segment construction is reduced.

[0008] The polyurethane foam used for the water-stopping material of the present invention has a volumetric water expansion ratio of usually 1.2 to 8 times, preferably 2 to 6 times in purified water at 23 ° C. The volumetric water expansion ratio in this case is a ratio at which the volume increases due to water absorption, and is obtained by the following method. If the volumetric water expansion ratio is less than 1.2 times, the water stopping effect after water expansion cannot be sufficiently obtained, and if it exceeds 8 times, the resin strength after water absorption and expansion decreases, so that the water stopping performance is poor. It cannot be maintained.
In order to obtain the above volumetric water expansion ratio, the content of the oxyethylene group in the polyurethane foam is preferably from 5 to 80% by mass, particularly preferably from 10 to 60% by mass. (Volume water expansion ratio) 2 from polyurethane foam band
A test piece of 0 × 20 × 2 mm was collected, and this test piece was
The volume when immersed in purified water at ℃ is measured at regular intervals, the volumetric water expansion ratio is calculated by the following formula, and the ratio when the volume increase per day becomes 0.01 times or less is calculated. , The volume expansion ratio of the test piece. Volume expansion ratio (times) = volume after expansion / volume before expansion

In the water-stopping material made of the polyurethane foam of the present invention, since the resin itself forming the partition walls for cells expands, a sufficient expansion effect can be obtained by diffusion of water into the resin, and the water-stopping material is stable for a long period of time. The expanded expansion performance is shown. When the polyurethane foam is immersed in purified water at 70 ° C. for 7 days and when immersed in purified water at 23 ° C. for 180 days, the mass reduction rate is usually 3% by mass or less, and preferably 1% by mass or less. The mass reduction rate is a measurement of the change in mass before and after expansion when immersed in purified water, as is usually performed as a method for evaluating the performance of a water-swellable sealing material. Is considered to fall out of the system, and the smaller the decrease in mass, the better the durability of the expansion performance.

In the conventional water-swellable foam waterproofing material, it is necessary to partially open the air bubbles so that water spreads to a water-swelling component (for example, a water-absorbing resin) kneaded in the foam.
It is the water-stopping material of the present invention that improves the rate of mass reduction and causes deterioration of the water-stopping material. Since the water-stopping material made of the polyurethane foam of the present invention does not need to be communicated, the closed cell content by the air pycnometer (air comparison specific gravity meter) method is usually 60% or more,
It is preferably at least 80%. In general, the water-swellable water-stopping material has an effect of providing an airtight and waterproof effect by compressive stress generated by compression of the water-stopping material in the initial stage of construction, but in particular, the water-stopping material of the present invention generates bubbles as described above. Since there is no need for partial communication, there is an advantage that the relaxation of the compressive stress is smaller than that of the conventional water-expandable water-stopping material due to the elasticity of the closed cells, and the airtight waterproof effect can be maintained for a longer time.

The polyurethane foam used for the water-stopping material of the present invention has a compressive stress at a compressibility of 50% of preferably 1 to 25 kgf / cm ² , particularly preferably 5 to 20 kgf.
f / cm ² . Compressive stress at compressibility 50% is 1
airtight waterproof in construction initial stage is kgf / cm ² or more is good, when used as a tenon with the segment sealing material When it is 25 kgf / cm ² or less, the segments for performing crushing in water stopping material Since the pressing force does not increase, there is no possibility that the accuracy of assembling the segments is adversely affected, and there is no possibility that cracks are generated in the uneven portions of the segments. In addition, as the expansion proceeds, the conventional water-swellable foam waterproofing material expands, the absorbed water acts like a plasticizer for the rubber, so that the rubber softens and the gap between the segments (gap between the segments) increases. When is large, a sufficient inflation pressure cannot be obtained. In the water-stopping material of the present invention, the polyurethane foam itself expands, the plasticizing effect by the absorbed water is small, and the expansion stress is effectively exhibited. Therefore, a better water stopping effect can be obtained.

The polyurethane foam can be produced by using a foaming agent foaming method, a mechanical floss method and / or a syntactic foam method as a molding method. In any of the molding methods, for example, a polyoxyalkylene polyol (a1) containing oxyethylene units, or a polyoxyalkylene polyol (a2) containing no (a1) and oxyethylene units, and an aliphatic, alicyclic or Using the araliphatic polyisocyanate (b), a polyurethane foam can be produced by either a prepolymer method or a one-shot method. The prepolymer method containing a terminal isocyanate group is preferred because the reactivity during foam production can be easily controlled.

Examples of the polyoxyalkylene polyol (a1) containing oxyethylene units include polyoxyalkylenes of low molecular weight active hydrogen-containing compounds having a number average molecular weight of 400 or less as exemplified in the following (1) to (3). Ethers (at least a part of the polyoxyalkylene group is a polyoxyethylene group), for example, an ethylene oxide (hereinafter abbreviated as EO) adduct of this low-molecular-weight active hydrogen-containing compound and / or EO and another alkylene oxide [carbon Alkylene oxide of formula 3 or 4, for example, one or more of propylene oxide (hereinafter abbreviated as PO), butylene oxide, tetrahydrofuran and the like]
(Random co-adduct or block co-adduct), and two or more of these may be used in combination. The content of EO in the alkylene oxide used for the adduct is preferably 20 to 100% by mass, and more preferably 30 to 90% by mass.

Examples of the low molecular active hydrogen-containing compound include:
Examples include the following: (1) Low-molecular polyols: dihydric alcohols such as ethylene glycol, propylene glycol, 1,4- or 1,3-butanediol, diethylene glycol, cyclohexylene glycol; glycerin, trimethylolpropane, pentaerythritol, sorbitol, and shoe rose And 3 to 8 or more polyhydric alcohols. (2) Polyhydric phenols: polyhydric phenols having 2 to 8 or more valences, for example, monocyclic phenols such as hydroquinone, resorcinol, and catechol; bisphenols such as bisphenol A, bisphenol B, bisphenol F, and bisphenol S Such. (3) Low molecular amines: alkanolamines (monoethanolamine, monobutanolamine, triethanolamine, isopropanolamine, N-methyldiethanolamine, etc.), alkylamines [carbon number: 2 to 1
5] (ethylamine, n-butylamine, octylamine, etc.), alkylene [carbon number of alkylene group: 2 to 2]
6] polyamine (ethylenediamine, hexamethylenediamine, diethylenetriamine, etc.), alicyclic diamine [carbon number: 4 to 15] (isophoronediamine, cyclohexylenediamine, etc.), aromatic diamine [carbon number: 6]
To 20] (phenylenediamine, diaminotoluene, diethyltoluenediamine, dimethylthiotoluenediamine, xylylenediamine, etc.), heterocyclic polyamine [carbon number: 4 to 15] (aminoethylpiperazine, etc.)
Such.

Preferred as (a1) are polyoxyethylene-polyoxypropylene ethers of low molecular polyols or polyhydric phenols (especially bisphenols) [co-added (random or block) with EO and PO]. . And a combination thereof, and more preferred are polyoxyethylene-polyoxypropylene ethers of polyhydric phenols. this is,
Polyoxyethylene-polyoxypropylene ethers of low molecular polyols is because the reactivity is easily adjusted, polyurethane foam derived from polyoxyethylene-polyoxypropylene ether of polyhydric phenols having an aromatic ring is This is because physical properties after water expansion are good. The number average molecular weight of (a1) is preferably 600
6000, more preferably 1000-5000. Also, the average number of functional groups of (a1) (average number of —OH groups)
Is preferably 2 to 4, and more preferably 2 to 3.

In the water-stopping material of the present invention, a polyoxyalkylene polyol (a2) containing no oxyethylene unit is preferably used as the polyol so that the content of oxyethylene groups in the polyurethane foam is 5 to 80%. You may use it in the range. Examples of (a2) include polyoxyalkylene ethers (the alkylene group has 3 and / or 4 carbon atoms) of low-molecular-weight active hydrogen-containing compounds such as (1) to (3) above, and alkylene oxides other than EO [ Or one or more of alkylene oxides having 3 or 4 carbon atoms, for example, PO, butylene oxide, tetrahydrofuran, etc.] (co-addition may be random addition or block addition). . Of these, preferred are low molecular polyols or polyhydric phenols (particularly bisphenols) for the same reasons as in (a1).
Is a polyoxypropylene ether. The number average molecular weight of (a2) is preferably from 600 to 6000, more preferably from 1,000 to 5,000. The average number of functional groups (average number of -OH groups) in (a2) is preferably 2 to
4, more preferably 2-3.

The aliphatic, alicyclic or araliphatic polyisocyanates (b) include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, lysine Diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, etc. (excluding carbon in NCO group, the same applies hereinafter) Aliphatic polyisocyanate of No. 18; isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated T I), bis (2-isocyanatoethyl) 4-cyclohexene-1,2-dicarboxylate of the carboxylate carbon atoms such as 4 to 15 alicyclic polyisocyanates;
C8 to C15 araliphatic polyisocyanates such as xylylene diisocyanate (XDI) and tetramethyl xylylene diisocyanate (TMXDI); Group,
Modified products containing a buret group, an isocyanurate group, etc.). In consideration of chemical resistance, weather resistance, etc., preferred among these are aliphatic or alicyclic diisocyanates, and particularly preferred are HDI and IPDI.
And hydrogenated MDI.

As an example of a method for producing a prepolymer having an isocyanate group at the terminal, which is an intermediate when the polyurethane foam used as the water-stopping material of the present invention is produced by a prepolymer method, an excess of the above-mentioned (a1) and (a1) is given. Equivalent [the equivalent of the isocyanate group in (b) to 1 equivalent of the active hydrogen-containing group in (a1) is preferably 1.2 to 1
0] (b), preferably by a conventional method at 60 to 150 ° C. The isocyanate group content in the obtained prepolymer is preferably 2 to 25% by mass, more preferably 4 to 20% by mass. For the purpose of adjusting the content of oxyethylene groups in the polyurethane foam to a preferable range of 5 to 80% by mass, if necessary, (a2) may be used during the production of the prepolymer.

In both the one-shot method and the prepolymer method, a curing agent (such as a chain extender or a cross-linking agent) is used as required when producing the above polyurethane foam. Examples of the curing agent include those exemplified as the low-molecular-weight active hydrogen-containing compound used as the raw material of the above (a1).
Low molecular polyols and polyamines (including diamines) among low molecular amines can be used. Further, a high molecular compound such as the compounds exemplified as the above (a1) and (a2) can be used as a curing agent.
Two or more curing agents may be used in combination.

In the production of the polyurethane foam, a urethanization reaction catalyst (a metal catalyst such as dibutyltin dilaurate, lead octylate, and stannas octoate; an amine catalyst such as triethylamine and triethylenediamine, etc.), a filler (talc) , Bentonite, calcium carbonate, lithopone, silica, mica, etc.), coloring agents (titanium white, red iron, carbon black, chrome green, etc.), ultraviolet absorbers (triazole type, benzophenone type, etc.), antioxidants (hindered phenol type) , A hindered amine or the like), a plasticizer (a phthalic acid ester, an adipic acid ester, or the like) and the like, and the urethanization reaction can be performed.

With respect to the use amount of these components, the amount of the catalyst is preferably 5% or less, more preferably 0.001 to 3.5%, based on the total mass of all components for obtaining a polyurethane foam. The filler is preferably at most 50%, more preferably at most 30%. The colorant is preferably 1% or less. The ultraviolet absorber is preferably 1% or less, and more preferably 0.01 to 0.5%.
%. The content of the antioxidant is preferably 1% or less, more preferably 0.01 to 0.5%. The plasticizer is preferably at most 10%, more preferably at most 5%.

As the blowing agent in the blowing agent foaming method, water,
Usable foaming agents for polyurethane foam, such as methylene chloride, halogenated hydrocarbons containing hydrogen atoms (alternative fluorocarbons), low-boiling hydrocarbons, and liquefied carbon dioxide, can be used. Two or more foaming agents may be used in combination. Specific examples of the hydrogen atom-containing halogenated hydrocarbon include HCFC (hydrochlorofluorocarbon) type (for example, HCFC-123, H
CFC-141b, HCFC-22 and HCFC-1
42b) HFC (hydrofluorocarbon) type (for example, HFC-134a, HFC-152a,
HFC-356mff, HFC-236ea, HFC-
245ca, HFC-245fa and HFC-365
mcf) and the like. The low-boiling hydrocarbon is a hydrocarbon having a boiling point of usually -5 to 70C, and specific examples thereof include butane, pentane, cyclopentane and a mixture thereof. Among these, foaming with water is preferred.

When water is used, the amount used is based on the total mass of the polyol used for forming the polyurethane foam.
Usually, it is 0.1 to 30%, preferably 1 to 20%. When methylene chloride is used, the amount used is usually 50% or less, preferably 5 to 45%, based on the total mass of the polyol.
It is. When a hydrogen atom-containing halogenated hydrocarbon is used, the amount used is usually 50 to the total mass of the polyol.
% Or less, preferably 5 to 45%. When a low-boiling hydrocarbon is used, the amount used is usually 45% or less, preferably 5 to 40%, based on the total mass of the polyol. When liquefied carbon dioxide is used, the amount used is usually 30% or less, preferably 5 to 25%, based on the total mass of the polyol.
It is.

The mechanical floss method is a foaming method in which an inert gas such as air or nitrogen is mixed with a raw material mixture for urethanization reaction as described above using a mixing head to mix bubbles. Foaming by mixing nitrogen is preferred.
The syntactic foam method is a method of forming a foam using hollow microspheres. As the hollow microspheres, hollow microspheres made of an inorganic substance (glass balloon, silica balloon, etc.), hollow microspheres made of a thermosetting resin (phenol resin balloon, epoxy resin balloon, etc.), hollow microspheres made of a thermoplastic resin [ Acrylic resin (polyacrylonitrile) balloon, polyvinylidene chloride balloon, etc.)
Etc. can be used. Preferably, it is an acrylic resin balloon. In the foaming agent foaming method and mechanical floss method,
A small amount of hollow microspheres may be added as a bubble retaining material.
The amount of the hollow microspheres used is preferably 60% or less, more preferably 0.2 to 40%, based on the total mass of all components for obtaining the polyurethane foam.

In the foaming agent foaming method and the mechanical floss method, it is preferable to use a foam stabilizer, particularly a foam stabilizer which forms closed cells, for stabilizing bubbles. As a foam stabilizer,
An ordinary foam stabilizer for polyurethane foam can be used, and examples thereof include a silicone-based surfactant such as a polyoxyalkylene-polysiloxane copolymer. Specific examples of the foam stabilizer that forms closed cells include SZ-193.
1, SZ-1323, SZ-1340 (manufactured by Nippon Unicar Co., Ltd.), SF-2962, SF-2965, SH-
190, SH-192 [manufactured by Toray Dow Corning Silicone Co., Ltd.] and the like. The amount of the foam stabilizer used is preferably 3% or less, more preferably 0.1 to 2%, based on the total mass of all components for obtaining the polyurethane foam.
%. In the mechanical froth foaming method and the syntactic foam method, a dehydrating agent (calcium oxide, calcium sulfide, calcium chloride,
Molecular sieve). The amount of the dehydrating agent used is preferably 8% or less, more preferably 0.5 to 6%, based on the total mass of all components for obtaining the polyurethane foam.

An example of a method for producing a polyurethane foam used for the water-stopping material of the present invention by a foaming agent foaming method is as follows.
A prepolymer from (a1) and (b) as a main component,
A mixture of (a2) in which an additive such as a catalyst, an antioxidant and the like and a foaming agent (for example, water) are preliminarily mixed is used as a curing agent component. The above polyurethane foam is obtained. In the mechanical floss method, for example, the above prepolymer is used as a main component, and (a)
2) As a curing agent component, a mixture of a catalyst and an antioxidant in advance is used, and the above-mentioned polyurethane foam is cast into a mold by a mechanical floss foaming machine while blowing nitrogen into the curing agent component. can get. In the syntactic foam method, for example, the above-mentioned prepolymer is used as a main component, and a premix of (a2) with a catalyst, an antioxidant, a dehydrating agent and hollow microspheres is used as a curing agent component. The above-mentioned polyurethane foam is obtained by casting in a mold with a mold machine. Among these molding methods, a mechanical floss method and / or a syntactic foam method are preferable because they can be easily adjusted to a target density.

In any of the above molding methods, the equivalent ratio of the active hydrogen-containing group of the curing agent component to the isocyanate group of the main component is preferably 0.7 to 1.5, more preferably 0.9 to 1.3. It is. In any molding method, the urethane and / or urea group content in the obtained polyurethane foam is preferably 0.5 to 1.8 in order to improve the mechanical properties before and after expansion.
mol / 1000 g, more preferably 0.6 to 1.5
mol / 1000 g. Further, the content of the aromatic ring in the polyurethane foam is preferably 0.1 to 1.5 mol / 1000 g, more preferably 0.15 to 1.0 mol / 1000 g, in order to improve the physical properties after water expansion. The aromatic ring content derived from the polyol in the polyurethane foam is preferably 0.1 to 1.5 mol.
/ 1000g, more preferably 0.15 to 1.0mo
1/1000 g.

The water-stopping material of the present invention comprises a molded or molded product of the above polyurethane foam. To exemplify the molding or forming method of the polyurethane foam, a mold in which a cylindrical metal core is set at the center of a cylindrical mold is provided with a main component and a curing agent according to any of the foaming methods described above. Mix and cast the ingredients, preferably 60
Heat curing at ~ 150 ° C for 2-30 hours to obtain a cylindrical molded product having a metal core in the center. This molded product is attached to a band knife type peeling machine which is usually used for manufacturing a long sheet of a soft foam,
A sheet having a predetermined thickness is obtained. After winding this into a predetermined length, the foamed sheet wound into a roll is cut into a predetermined width by a round knife cutter to obtain a strip-shaped molded product of a polyurethane foam having a rectangular cross section. In addition, according to the above-mentioned method, a polyurethane foam obtained by slab foaming can be cut without using a mold to obtain a molded product. Alternatively, a rod-shaped molded product can be manufactured by similarly injecting the mixed solution into a prismatic closed mold and heat-curing the mixture.

The molded article or molded article of the polyurethane foam and a non-water-swellable porous or non-porous elastic body are laminated to form a laminate as shown in FIG. 1, for example. It can also be used as a waterproof material. FIG.
In (1), (1) is an oxyethylene group-containing polyurethane foam used in the present invention, and (2) is a non-water-swellable, porous or non-porous elastic body. As the elastic body, an elastic body or a porous body made of ordinary natural rubber or synthetic rubber (styrene butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, butyl rubber, etc.) is used. An elastic body can be used, and preferably 1 to 25 as in the above polyurethane foam.
It is a non-water-swellable porous elastic body having a 50% compressive stress of kgf / cm ² .

The water-stopping material of the present invention can be used as an ordinary segment sealing material or box-culvert water-stopping material when the opening (gap) between the segments is small during the segment construction. In particular, there are irregularities in the combination surface of the segments that construct the tunnel, and when fitting the segments for fitting, it can be suitably used as a waterproof material for sealing a tenoned segment that requires a lower compressive stress. .

FIG. 2 shows a perspective view of one embodiment of a segment with a tenon used for a shield construction method when constructing a tunnel. Fig. 3 shows the tenon (projection) of the tenoned segment
FIG. 10 is a partial cross-sectional view showing a state in which sealing is performed by combining a mortise and a tenon (recess). 2 and 3, 21 is a tenon (convex), 22 is a tenon (concave), 23 and 24 are seal grooves, 25 and 26 are seal grooves, 27 is a fastening portion between rings, and 28 is a piece. The fastening portion 30 is the waterproof material of the present invention. Also, in the figure, the direction of arrow A indicates the outside direction of the tunnel, the direction of arrow B indicates the inside of the tunnel, and the surface indicated by arrow C is the surface of the tenon (recess side) of the tenoned segment. The surface on the side indicated by the arrow D indicates the surface of the tenon (convex portion) of the tenoned segment. Then, as shown in FIG. 3, a plurality of tenoned segments are prepared, and the tenon (concave side) surface on the side indicated by arrow C and the tenon (convex) on the side indicated by arrow D are prepared. The mortise portion (convex portion) 21 and the tenon portion (concave portion) 2
2 are fitted so that the seal grooves 23 and 2
Between 4 and 25 and 26, a waterproof material 30 formed into a strip shape according to the present invention is inserted and sealed. In addition,
Some segments do not have the seal grooves 25 and 26 depending on the shape of the segment.
Only between 3 and 24, the water-stopping material formed into a belt shape according to the present invention is inserted.

[0032]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

Example 1 The main ingredient was the following prepolymer. Bisphenol A
A mixture of EO and PO (mass ratio 80/20) was added to 10000 g of polyether glycol having a number average molecular weight of 4000 and 3570 g of dicyclohexylmethane diisocyanate were reacted at 120 ° C. for 90 minutes to obtain an isocyanate group content of 90%. 7.5% by weight of prepolymer 13
570 g were obtained. The curing agent components were 1820 g of diethyltoluenediamine, 27.1 g of water (foaming agent), and a foam stabilizer S
A mixture of 157 g of Z-1931 (manufactured by Nippon Unicar Co., Ltd.) and 15.7 g of dibutyltin dilaurate (catalyst) was mixed,
019.8 g were produced. In a 200 mm diameter, 150 mm height cylindrical mold with a metal core set in the center,
The main agent and the curing agent component are mixed and cast at the above-mentioned ratio (the ratio at which the equivalent ratio of amino groups to isocyanate groups of the prepolymer is 1.05) by a two-liquid mixing casting machine.
Heat cured at 0 ° C for 90 minutes, post-cured at 80 ° C for 24 hours,
A cylindrical molded product having a metal core in the center was obtained (aromatic ring content: 0.98 mol / 1000 g, of which aromatic ring content from polyol: 0.32 mol / 1000).
g, urethane and / or urea group content: 1.4 mo
1/1000 g, 83% closed cell content by air pycnometer method). This molded product was cut into a sheet having a thickness of 10 mm using a peeling machine, wound up in a roll shape, and then cut with a round knife cutter to a width of 20 mm.
And a strip-shaped molded product having a thickness of 10 mm and a width of 20 mm was obtained. Table 1 shows the characteristic values of the strip-shaped molded product.

Example 2 The main ingredient was the following prepolymer. 10,000 g of a polyether glycol having a number average molecular weight of 4000 obtained by adding a mixture of EO and PO (mass ratio 50/50) to propylene glycol, and isophorone diisocyanate 2
360 g are reacted to give an isocyanate group content of 5.5.
12360 g of a prepolymer by weight were obtained. The curing agent component is an EO adduct of bisphenol A (number average molecular weight 67
0) To 5380 g, 157 g of a foam stabilizer SZ-1931 (manufactured by Nippon Unicar Co., Ltd.) and 53.7 g of lead octylate (catalyst).
g and Molecular Sieve 3AB [manufactured by Union Carbide Co., Ltd., dehydrating agent] 269 g, and 5859.7 g.
Created. The main agent and the hardener component are mixed in the above liquid ratio (equivalent ratio of hydroxyl group to isocyanate group of the prepolymer is 1.03.
Ratio. ), At a total speed of 3 kg / min, 0.8
Mixing and casting with a mechanical floss foaming machine (MF350 type, manufactured by Toho Machinery Co.)
Heat curing at 110 ° C. for 4 hours and post-curing at 80 ° C. for 24 hours to obtain a cylindrical molded product having a metal core at the center. Peeling to a thickness of 10 mm and cutting to a width of 20 mm resulted in a strip-shaped molded product having a thickness of 10 mm and a width of 20 mm (aromatic ring content: 0.88 mol / 1000 g, of which aromatic ring content from polyol: 0.88 mol / 1000).
g, urethane and / or urea group content: 0.88 m
ol / 1000 g, closed cell content 90%). Table 1 shows the characteristic values of the strip-shaped molded product.

Example 3 The main ingredient was Duranate D-101 [Asahi Kasei Corporation]
MDI-based bifunctional prepolymer, isocyanate group content: 19.0% by mass] 1653 g. The curing agent components were: 4000 g of polyether glycol having a number average molecular weight of 4000 obtained by adding a mixture of EO and PO (mass ratio 80/20) to bisphenol A;
Polyether triol 60 having a number average molecular weight of 3000 obtained by adding a mixture of O and PO (mass ratio 20/80).
To a mixture of 00 g, 173 g of a foam stabilizer SZ-1931 (manufactured by Nippon Unicar Co., Ltd.) and 61.1 of lead octylate (catalyst).
g, acrylic balloon MFL-80ED [Matsumoto Yushi Seiyaku Co., Ltd., acrylic resin hollow microspheres, density 0.023]
23.0 g and 173 g of Molecular Sieve 3AB (manufactured by Union Carbide Co., Ltd., dehydrating agent) were mixed, and 104
30.1 g was prepared. A total of 3 kg of the main agent and the curing agent component in the above-mentioned liquid ratio (a ratio at which the equivalent ratio of hydroxyl groups to isocyanate groups of duranate D-101 is 1.10).
Per minute at a rate of 0.3 l / min dry nitrogen with a mechanical floss foaming machine (MF350, Toho Kikai)
), Heat-set at 110 ° C for 6 hours, 8
Post-cured at 0 ° C for 24 hours, peeled to a thickness of 10mm, sliced to a width of 20mm, thickness 10mm, width 20mm
(Aromatic ring content: 0.17 mol)
/ 1000 g, of which the aromatic ring content from the polyol: 0.1.
17 mol / 1000 g, urethane and / or urea group content: 0.66 mol / 1000 g, closed cell content 98%). Table 1 shows the characteristic values of the strip-shaped molded product.

Example 4 A cylindrical molded product having a metal core at the center obtained in Example 1 was peeled off to a thickness of 7 using a peeling machine.
When cut into a sheet having a thickness of 3 mm and wound into a roll, a chloroprene foam having a thickness of 3 mm (containing closed cells, a density of 0.85 g / cm ³ , and a compressive stress at a compressibility of 50%: 20)
kgf / cm ² ) is wound up in a roll shape while being adhered with a chloroprene-based adhesive [Quick Dry Bond G-17: manufactured by Konishi Co., Ltd.], and is sliced into a width of 20 mm and a thickness of 10 m.
m, and a strip-shaped molded product having a width of 20 mm was obtained. Table 1 shows the characteristic values of the strip-shaped molded product.

Comparative Example 1 Ethylene propylene rubber (EPDM) was mixed with a polyacrylate water-absorbing resin, Sunfresh ST-500M
PS [manufactured by Sanyo Chemical Industries, Ltd.] and isobutylene-maleic anhydride alternating copolymer-based water-absorbing resin, KI gel 201K
-F2 (Kuraray Co., Ltd.) as a water-absorbent resin, kneaded with the following composition (parts by mass), and then vulcanized at 150 ° C. for 30 minutes.
After foaming and cooling, a part of the air bubbles was broken by pressurization to obtain a water-swellable rubber foam of half-semi-solo (closed cell content: 50%). This was cut into a strip having a thickness of 10 mm and a width of 20 mm to obtain a specimen. Compounding ratio (parts by mass) EPDM 100 parts Zinc oxide 5 parts Stearic acid 3 parts Carbon black 5 parts Clay 75 parts Process oil 40 parts Sulfur 1.5 parts Butylthiourea 2.0 parts Blowing agent (azodicarbonamide) 5 parts Foaming aid Agent [Cell paste K-5, manufactured by Eiwa Chemical Co., Ltd.] 2 parts Sunfresh ST-500MPS 30 parts KI gel 201K-F2 30 parts

Comparative Example 2 The main ingredient was TDI-65, 30.8 parts by mass. The curing agent component is EP-550H [manufactured by Mitsui Nisso Co., Ltd., a polyether polyol containing no oxyethylene group] 100
30 parts by mass of Sumikagel A-40 (manufactured by Sumitomo Chemical Co., Ltd., water-absorbent resin), 2 parts by mass of foam stabilizer F-258 (manufactured by Shin-Etsu Chemical Co., Ltd.), stanna octoate (catalyst)
0.15 parts by mass and 0.5 parts by mass of water (foaming agent) were mixed. In the same manner as in Example 1, the main agent and the curing agent component were mixed and cast at the above-mentioned liquid ratio (a ratio at which the equivalent ratio of hydroxyl groups to isocyanate groups of TDI-65 was 1.20). For 3 hours, post-curing at 80 ° C. for 24 hours, peeling to a thickness of 10 mm, and cutting to a width of 20 mm to obtain a strip-shaped molded product having a thickness of 10 mm and a width of 20 mm. This was pressurized to break some of the air bubbles to obtain a water-swellable rubber foam of half-semi-solo (closed cell content: 50%). Table 1 shows the characteristic values of the strip-shaped molded product.

[Performance Test Examples] Table 2 shows the tensile properties of the specimens of Examples 1 to 4 and Comparative Examples 1 and 2, and Table 3 shows the results of the long-term expansion test and the mass reduction rate test. Are shown in Table 4 and the results of the water stop performance test are shown in Table 5. The test method is as follows. (Density) Measured according to ASTM D2406. (Compression stress) A test piece of 10 cm of the water-stop material of each of Examples 1 to 4 and Comparative Examples 1 and 2 was sandwiched between a pair of steel flat plates, and the compression tester was used to reduce the compression ratio to 50%. It was compressed and the compressive stress per unit area was calculated. (Tensile physical properties) Measured with a No. 3 dumbbell test piece according to "Vulcanized Rubber Physical Test Method" described in JIS K6301.

(Volume water expansion ratio)
A test piece of × 20 × 2 mm was collected, and the test piece was heated at 23 ° C.
The volume when immersed in purified water was measured every day, and the volumetric water expansion ratio was calculated by the following formula. Volume expansion ratio. Volumetric water expansion ratio (times) = Volume after expansion / Volume before expansion (Volume expansion ratio) A 20 × 20 × 2 mm test piece is collected from a sample strip and immersed in purified water at 23 ° C. The volume at that time was measured every predetermined period, and calculated by the following equation. Volume expansion rate (%) = 100 × (volume after expansion−volume before expansion) / volume before expansion (mass reduction rate [70 ° C.]) 20 × 20 from the sample band
A test piece of × 2 mm was collected, and this test piece was immersed in purified water at 70 ° C. for 7 days, and then dried in a 60 ° C. oven. Is the mass after drying, and was calculated by the following equation. Mass reduction rate (%) = 100 × (mass before expansion−mass after drying) / mass before expansion (mass reduction rate [23 ° C.]) The test piece after measuring the volume expansion rate for 180 days is placed in an oven at 60 ° C. And the mass when the decrease in mass is 0.1 g or less is regarded as the mass after drying,
It was calculated by the following equation. Mass reduction rate (%) = 100 × (mass before expansion−mass after drying) / mass before expansion

(Stress relaxation test) 10 cm of the waterproof material of Examples 1 to 4 and Comparative Examples 1 and 2 was used as a test piece, which was sandwiched between a pair of two steel flat plates, and compressed by a compression tester. Rate 50
%, The change with time of the compressive stress was measured, and after a predetermined period of time, the holding ratio to the compressive stress immediately after the compression was reduced to 50%. (Water stop performance test) As shown in FIG. 4 (plan view), test pieces (5) of the water stop materials of Examples 1 to 4 and Comparative Examples 1 and 2 were used.
After affixed to the lower plate surface (4) of the pair of steel flanges (3 and 4) with an adhesive in a circular band shape as shown in FIG.
As shown in (cross-sectional view), the test device is tightened to a predetermined compression amount with a bolt and a nut (9) using a spacer (8). Then, after filling the inside of the test apparatus with water, water pressure is applied by a hydraulic pump (12) and the pressure is measured by a pressure gauge (11). In FIG. 4, (6) is a bolt hole,
(7) shows a pipe mounting hole, and in FIG. 5, (10) shows an air vent valve. With this apparatus, when the compression ratio was 0% and when the compression ratio was minus 20%, the time required until water leakage disappeared was measured by continuously applying a predetermined water pressure.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[0045]

[Table 4]

[0046]

[Table 5]

[0047]

The water-stopping material of the present invention is a water-stopping material comprising a molded article or a molded article of an oxyethylene group-containing polyurethane foam. Since the polyurethane foam itself expands, the water-stopping material contains an expanding component which elutes into water. It does not contain, has a small mass reduction rate, and shows stable expansion performance over a long period of time. Because of the above effects, the water-stopping material of the present invention can be used as a normal segment sealing material or box-culvert water-stopping material when the opening (gap) between segments is small during segment construction. In particular, it is useful as a tenon-attached segment sealing material used at the time of segment construction, which has unevenness on the combination surface of the segments forming the tunnel and requires lower compressive stress for fitting.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a water-stopping material having a two-layer structure obtained by laminating an oxyethylene group-containing polyurethane foam of the present invention and a porous elastic body.

FIG. 2 is a perspective view showing one embodiment of a tenoned segment.

FIG. 3 is a partial cross-sectional view showing a state in which a tenon (convex) and a tenon (concave) of a tenoned segment are combined to perform sealing.

FIG. 4 is a conceptual plan view showing a state in which a steel flange and a test piece used for measuring the water stopping performance are attached.

FIG. 5 is a conceptual cross-sectional view showing a measurement state of water stopping performance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyurethane foam containing an oxyethylene group 2 Porous elastic body 3 Upper steel flange 4 Lower steel flange joint surface 5 Test piece 6 Bolt hole 7 Piping mounting hole 8 Spacer 9 Bolt, nut 10 Air release valve 11 Pressure gauge 12 Water pressure pump 21 Mortise (convex) 22 Mortise (concave) 23,24,25,26 Seal groove 27 Fastening between rings 28 Fastening between pieces 30 Waterproof material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-183963 (JP, A) JP-A-9-296022 (JP, A) JP-A-10-3807 (JP, A) JP-A-8- 333432 (JP, A) JP-A-8-231668 (JP, A) JP-A-6-206966 (JP, A) JP-A-63-22819 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18/48

Claims (11)

(57) [Claims] 1. A waterproof material comprising a polyurethane foam, wherein the polyurethane foam weighs 0.3 to 0.9 g.
/ Cm ³ and a volume expansion ratio of 1.2 to 8 times, when immersed in water at 70 ° C. for 7 days and in water at 23 ° C.
A water-stopping material which is an oxyethylene group-containing polyurethane foam having a mass reduction rate of 3% or less when immersed for 80 days, and which is a molded article or a molded article. 2. The polyurethane foam according to claim 1, wherein said polyurethane foam is 1 to 25 k.
^2. The water stopping material according to claim 1, which has a compressive stress at a compression ratio of 50% of gf / cm ² . 3. The waterproof material according to claim 1, wherein said polyurethane foam contains 5 to 80% by mass of oxyethylene groups. 4. The waterproof material according to claim 1, wherein the polyurethane foam is a foaming agent foamed foam, a mechanical froth foam or a syntactic foam. 5. The waterproof material according to claim 1, wherein the polyurethane foam has a closed cell content of 60% or more. 6. The polyurethane foam according to claim 5, wherein
It has a urethane and / or urea group content of 1.8 mol / 1000 g, and 0.1 to 1.5 mol / 1000 g
The water-stopping material according to any one of claims 1 to 5, having an aromatic ring content of: 7. The polyurethane foam, comprising: a polyoxyalkylene polyol (a1) containing oxyethylene units, or (a1) and a polyoxyalkylene polyol (a2) containing no oxyethylene units.
The water-stopping material according to any one of claims 1 to 6, which is a polyurethane foam derived from an aliphatic, alicyclic or araliphatic polyisocyanate (b). 8. The waterproof material according to claim 1, wherein the molded product is a rectangular molded product having a rectangular cross section obtained by cutting a cylindrical molded product or a slab foam molded product. . 9. The waterproof material according to claim 1, further comprising a non-water-swellable, porous or non-porous elastic material laminated thereon. 10. The water-stopping material according to claim 1, wherein the water-stopping material is a tenon-sealed segment sealing material. 11. A water stopping method using the water stopping material according to any one of claims 1 to 10 in a shield construction method for constructing a tunnel by combining segments.