JP2878089B2 - Water expansion rubber waterproof material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a seal material for underground tunnels in civil engineering works, as a waterproof material for concrete casting in building works, a waterproof material for steel sheet piles, and a fume pipe packing. The present invention relates to a water-swellable rubber composition.

[0002]

2. Description of the Related Art In recent years, a water-swelling rubber, which expands when it comes into contact with water and exhibits a water-stopping effect, has been widely used as a water-stopping material used for concrete casting and the like.

[0003] Conventionally, a water-swelling rubber used as a water-stopping material is
There is known a rubber component of natural rubber and / or synthetic rubber mixed with a superabsorbent resin.

However, since the compatibility between the rubber component and the superabsorbent resin is not so good, the superabsorbent resin tends to elute from the water-expandable rubber during use and the volume expansion rate tends to decrease.

Therefore, when the conventional water-swelling rubber is used as a segment seal material, a water-stopping material for concrete casting or a water-stopping material for steel sheet piles, it may cause water leakage, which causes a problem in the water-stopping function. there were.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-swellable rubber composition having a small decrease in volume expansion coefficient and excellent in long-term stability.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to prevent the above-mentioned water leakage accident, and as a result, by using a specific polyurethane and a polyalkylene oxide derivative in combination, a conventional waterproof material has been obtained. It has been found that a water-swellable rubber composition having excellent long-term stability can be obtained without impairing the initial water-swelling function immediately after immersion in water, and the present invention has been completed.

That is, the present invention relates to (A) a superabsorbent resin: 5 to 100 parts by weight, (B) a polyalkylene oxide derivative: 1 to 30 parts by weight, based on 100 parts by weight of natural rubber and / or synthetic rubber. (C) Thermosetting polyurethane: 1 to 20 parts by weight of a water-swelling rubber waterproofing material obtained by vulcanizing and molding the following components:
Water-swelling rubber stopper characterized by enclosing a cloth during sulfur molding
It relates to water material.

The rubber in the water-swelled rubber composition of the present invention is a natural rubber and / or a synthetic rubber. Examples of the synthetic rubber include styrene butadiene rubber (SBR),
Isoprene (IR), polybutadiene (BR), acrylonitrile rubber (NBR), acrylic rubber (ACM),
Examples include ethylene propylene rubber (EPDM), chloroprene rubber (CR), fluorine rubber, urethane rubber, acryl-butadiene rubber (ABR), acrylonitrile-isoprene rubber (NIR), and acrylonitrile-chloroprene rubber (NCR). One or more of these general natural rubbers and synthetic rubbers can be appropriately selected and used.

The superabsorbent resin which is the component (A) of the water-swellable rubber composition of the present invention is not particularly limited as long as it is a resin which takes in water in the molecule and gels and swells, for example, isobutylene-maleic anhydride. Highly water-absorbing resins such as copolymers, polyvinyl alcohol-acrylic acid copolymers, starch derivatives, and carboxymethyl cellulose derivatives are exemplified.

In the present invention, the amount of the superabsorbent resin (A) is from 5 to 100 per 100 parts by weight of the rubber component.
Parts by weight, preferably 5 to 60 parts by weight. When the amount of the component (A) is less than 5 parts by weight, a predetermined expansion effect cannot be obtained, and
If the amount is more than 00 parts by weight, roll workability is remarkably reduced, which is not preferable.

The polyalkylene oxide derivative, which is the component (B) of the water-swellable rubber composition of the present invention, is compounded as a water channel agent for facilitating water penetration into the rubber composition. The polyalkylene oxide derivative in the present invention is a compound obtained by polymerizing or addition-polymerizing ethylene oxide and / or propylene oxide, for example, alkylene such as polyethylene glycol, polypropylene glycol, and ethylene oxide-propylene oxide copolymer. Oxide polymer or copolymer, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene alkyl ether such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether and polyoxyethylene And polyoxyethylene allyl ethers such as nonylphenyl ether.

In the present invention, the blending amount of the polyalkylene oxide derivative (B) is 1 to 30 parts by weight, preferably 5 to 10 parts by weight, per 100 parts by weight of the rubber component. If the amount of the component (B) is less than 1 part by weight, the permeation of water becomes non-uniform, and if the amount exceeds 30 parts by weight, the adhesive force of the rubber composition deteriorates.

The thermosetting polyurethane, which is a component (C) of the water-swellable rubber composition of the present invention, is compounded to prevent a decrease in the volume expansion coefficient of the water-swellable rubber and to enhance long-term stability. A prepolymer (molecular weight: 1,000 to 4,000) composed of ether glycol isocyanate
A curing agent (molecular weight: 100 to 400) comprising a polyether glycol derivative having a functional or higher terminal hydroxyl group is blended. The compounding amount of the curing agent depends on the N of the prepolymer.
Based on the CO content%, the OH equivalent of the curing agent and the OH / NCO ratio, the amount of the curing agent to be added to 100 parts by weight of the prepolymer is determined by the formula (1). The prepolymer and the curing agent are compounded in the raw rubber composition and cured by heat during vulcanization molding.

[0015]

(Equation 1)

In the present invention, the compounding amount of the thermosetting polyurethane (C) is 100 parts by weight of the rubber component.
It is 1 to 20 parts by weight, preferably 5 to 10 parts by weight. If the blending amount of the thermosetting polyurethane is less than 1 part by weight, the water swelling effect cannot be obtained, and if the blending amount exceeds 20 parts by weight, the roll workability decreases, which is not preferable.

The water-swelling rubber composition according to the present invention is usually compounded with a vulcanizing agent, and the vulcanizing agent may be a compound commonly used. Typical vulcanizing agents include, for example, sulfur, magnesium oxide, quinoid vulcanizing agents, peroxide vulcanizing agents, amine vulcanizing agents, resin vulcanizing agents, organic sulfur vulcanizing agents and the like. Can be

A vulcanization aid such as zinc white and a vulcanization accelerator such as a thiouram-based compound, a guanidine-based compound, a sulfenamide-based compound, a dithiocarbamate-based, a thiourea-based compound, and a xanthate-based compound are appropriately compounded. You may.

The water-swellable rubber composition of the present invention may contain an antioxidant, a plasticizer, a reinforcing agent, a bulking agent, a filler and the like as long as the object of the present invention is not impaired.

In order to form a water-stopping material from the water-swellable rubber composition of the present invention, a rubber component, (A) a highly water-absorbent resin, and (B)
Compounding a polyalkylene oxide derivative, (C) a thermosetting polyurethane (a mixture of a prepolymer and a curing agent),
Mix using a general rubber kneading machine such as an open roll, kneader, Banbury mixer, etc., and mold with a general rubber molding machine such as a calender, casting machine, extruder, etc., and general vulcanization such as heating press, injection, vulcanizer etc. Vulcanize with a machine. When water-swelling rubber is used as a water-stopping material for concrete casting, if it is submerged after being bonded to the concrete surface, it expands in the length direction and the bonded surface rises, impairing the water-stopping effect. As shown in FIG. 2, when the water-swellable rubber composition of the present invention is vulcanized and molded, the cloth is sealed, whereby expansion in the length direction is suppressed.

The cloth to be enclosed is not particularly limited, and examples thereof include woven cloths made of natural fibers such as cotton and silk or synthetic fibers such as nylon and polyester.

[0022]

EXAMPLES Reference Example 1 The rubber composition shown in Table 1 was kneaded with a test roll at about 50 ° C. and vulcanized with a vulcanizing press at 150 ° C. for 20 minutes to obtain 2 m
m was formed into a sheet. Roll blending properties, physical properties, and volume expansion rates upon immersion in water for a short time were measured. The volume expansion rate was calculated by the following equation (2), and the roll workability was evaluated according to the following criteria. Table 1 also shows the results.

[0023]

(Equation 2)

(Roll workability) The workability when kneading the rubber composition with a test roll was determined according to the following criteria.

…: Good workability 〃: 普通 Normal ×: 悪 い Bad The following 1) to 8) of the compounding agents in the table were used.

1) magnesium oxide 2) zinc white 3) HAF and crown clay 4) thiuram-based compound and sulfenamide-based compound 5) sulfur 6) polyvinyl alcohol-acrylic acid copolymer (trade name "Sumikagel SP520": Sumitomo) 7) Ethylene oxide-propylene oxide copolymer (trade name “Emulgen PP290”: manufactured by Kao Corporation) 8) Polyether glycol-based isocyanate and its curing agent (trade name “AQ74”: Sakai Chemical) (Made by Corporation)

[0027]

[Table 1]

As is clear from the results shown in Table 1, the composition No. of the present invention in which the thermosetting polyurethane and the ethylene glycol-propylene glycol copolymer were compounded. 4-6
The water-expandable rubber of the present invention has a large initial volume expansion coefficient and a high expansion rate, whereas the conventional compound No. No. As in 3, the superabsorbent resin must be incorporated in a large amount, and the roll workability is reduced, resulting in a decrease in physical properties.

Reference Example 2 To examine the long-term stability of the water-swelled rubber, the formulation No. 2
No. and conventional No. The rubber sheet of the present invention No. 5 was immersed in water, and the change in the volume expansion coefficient was examined. The result is shown in FIG.

As is apparent from the results shown in FIG. 1, the water-swelling rubber of the present invention containing a thermosetting polyurethane shows a decrease in the volume expansion coefficient even after 15 months, whereas the water-swelling rubber of the present invention contains a thermosetting polyurethane. From the first month, the stability of the volume expansion coefficient was recognized, indicating that the long-term stability was excellent.

Reference Example 3 In order to examine the elution of the superabsorbent resin and the like from the water-swelling rubber, the weight loss rate was measured. The test method was as follows. The weight of three samples each of the present invention (formulation No. 5) and a conventional example (formulation No. 2) vulcanized and molded to a size of 7 mm × 20 mm × 50 mm. The sample was immersed in water for 180 days. After immersion, the sample is dried and weighed,
The weight loss rate was determined by the equation (3). Table 2 shows the results.

[0032]

(Equation 3)

[0033]

[Table 2]

As is apparent from the results in Table 2, the weight of the conventional water-swellable rubber is reduced by 5% or more due to elution of the superabsorbent resin and the surfactant, whereas the water-swellable rubber of the present invention is reduced by the elution. It can be seen that the weight reduction rate is as small as 1.5%.

Example 1 Formulation No. 15 in which the superabsorbent resin was adjusted to 15 parts. The composition of No. 5 was mixed with a 75-liter kneader kneader, and an unvulcanized sheet having a thickness of 5 mm × 1 m × 10 m was prepared by calendering using a calender roll. Then, a cloth (sheet # 75) was inserted into the center of the thickness. A sheet having a thickness of 10 mm x 1 m x 5 m was used as a final dough adjustment, the dough was vulcanized with a 6 m press, and a slitting process was used to prepare a 10 mm thick x 20 mm wide x 5 m water-swelling water-stopping material with a concrete casting cloth. The obtained waterproof material with cloth was immersed in water for 2 months, and the shape change was examined. The change rate of the shape was calculated by the equation (4). Table 3 shows the results.

[0036]

(Equation 4)

[0037]

[Table 3]

As is evident from the results in Table 3, the water-swelling rubber waterproofing material with cloth of the present invention has a reduced elongation in the length direction. Therefore, when used as a waterproofing material for concrete casting, it does not float after bonding to the concrete surface, even if it is submerged, because it has little elongation in the length direction even if it is flooded.

[0039]

The water-swelling rubber water-stopping material of the present invention has a high initial volume expansion rate, a stable volume expansion rate over a long period of time, and little elution of compounding components. It is suitable as a waterproof material for installation and a waterproof material for steel sheet piles.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the volume expansion rate and the number of days of immersion in the present invention and the conventional example.

FIGS. 2A and 2B are views showing an example of a waterproof material enclosing the cloth of the present invention, wherein FIG. 2A is a perspective view and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water stop material with cloth 2 Water expansion rubber 3 Cloth

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification symbol FI // (C08L 21/00 71:02 75:04) (58) Investigated field (Int.Cl. ⁶ , DB name) C08L 21 / 00 C08L 71/02-71/03 C08L 75/04-75/16 C09K 3/10 E02D 31/02

Claims (1)

(57) [Claims] 1. A natural rubber and / or synthetic rubber 100
The weight part, (A) the superabsorbent resin: 5 to 100 parts by weight, (B) a polyalkylene oxide derivatives: 1-30 wt
Parts of (C) thermosetting polyurethane: 1 to 20 parts by weight of each component.
Water-swelling rubber stopper characterized by enclosing a cloth during sulfur molding
Water material.