JPS598753A - Water-absorbing polyurethane resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition which can be swollen with water for a long period and keep high water-stopping capability, by compounding a polyurethane resin or a raw material of polyurethane resin with a highly water-absorbing polymer and a sequestering agent. CONSTITUTION:100pts.wt. of a polyurethane resin or a raw material of polyurethane is mixed with 1-30pts.wt. of a highly water-absorbing polymer having a particle size of 1-100mu, (especially crosslinked sodium polyacrylate, etc. having a water-absorption ratio of >=100) and 0.2-5pts.wt., based on 100pts.wt. of the water-absorbing polymer, of a sequestering agent (e.g. ethylenediaminetetraacetic acid). Generally, the additives are added to the unpolymerized raw materials or to a prepolymer, and the mixture is converted to a urethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-absorbing polyurethane resin composition characterized by comprising a polyurethane resin or a polyurethane resin-forming raw material, a superabsorbent polymer, and a sequestering agent.

Conventionally, polyurethane sealants have been widely used in civil engineering and construction applications due to their excellent elasticity, water resistance, and durability. However, even when a polyurethane sealing material is used, it is difficult to expect that it will completely stop leakage of water such as rainwater due to peeling from the surface to which it is adhered due to shrinkage in cold weather. In order to overcome such disadvantages, a method is proposed in which a highly water-absorbing polymer is contained in a polyurethane resin to reduce shrinkage and prevent water leakage due to water absorption and swelling even after peeling (for example, Japanese Patent Laid-Open No. 55-128618 No. 2) has been proposed. However, in the short term, this method achieves its purpose, but in the long term, it is not able to produce rice that is completely satisfactory.

In view of the above circumstances, the present inventors conducted intensive research and found that a water-absorbing polyurethane resin composition containing a polyurethane resin or a polyurethane resin-forming raw material, a superabsorbent polymer, and a sequestering agent as constituent components has excellent sealing properties. effect,
That is, the present invention was completed by discovering that water leakage prevention performance can be maintained for a long period of time.

That is, the present invention provides a water-absorbing polyurethane resin composition containing a polyurethane resin or a polyurethane resin-forming raw material, a superabsorbent polymer, and a sequestering agent as essential components.

The superabsorbent polymer used as a component of the composition of the present invention is added to impart water swelling properties to the polyurethane sealant material, reduce shrinkage, and prevent peeling.

The superabsorbent polymer used as a component of the composition of the present invention is a polymer electrolyte that is physically or chemically crosslinked, and absorbs water at room temperature or in a heated state to reduce its own weight. It is a substance that swells several hundred times but does not dissolve in water and can maintain its elastic shape even when it absorbs water.

Examples of such superabsorbent polymers include starch/acrylic acid graft copolymers, salts of styrene-maleic anhydride copolymers, crosslinked products of sodium polyacrylate, and crosslinked products of polyvinyl alcohol/maleic anhydride reactants. Known super absorbent polymers such as vinyl ester/ethylenically unsaturated carboxylic acid or saponified derivatives thereof can be used. Among these, it is desirable to use a crosslinked product of sodium polyacrylate or a saponified product of a copolymer of vinyl ester and acrylic ester, as these have a high water absorption capacity and excellent strength after water absorption.

The shape of the superabsorbent polymer is generally 1 to 100/7, since if the particle size exceeds iooμ, the superabsorbent polymer is likely to fall off during water absorption. A superabsorbent polymer having a water absorption capacity of 100 times or more is preferably used.

The sequestering agent used as a component of the composition of the present invention is a highly water-absorbing polymer mixed with a polyurethane resin, which has the ability to absorb water and swell due to salts contained in rainwater, especially polyvalent metal ions of divalent or higher valence. It is added to prevent deterioration and to impart long-term water swelling properties to polyurethane sealants.

The sequestering agents used in the present invention include compounds capable of forming chelates with ethylenediaminetetraacetic acid and its metal salts, polyphosphates such as sodium tripolyphosphate, sodium pyrophosphate, and other sodium polyphosphates, and mixtures thereof. can be mentioned.

The polyurethane resin used in the present invention is a polymer commonly used as a sealing material obtained by a known reaction of polyisocyanate, polyol, polyamine, water, etc., and may be either a one-shot type or a prepolymer type. good. Additionally, commonly used additives for polyurethane, such as tar, asphalt, animal and vegetable oils, plasticizers such as dioctyl phthalate and dibutyl phthalate, fillers such as calcium carbonate, clay, talc, titanium dioxide, etc. It may also contain agents, colorants, foaming agents, etc.

The filler is not particularly limited as long as it is a commonly used filler, but in order to cause the superabsorbent polymer to swell in a short time, it is preferable to use bentonite, which has high hygroscopicity, in combination.

The water-absorbing polyurethane resin composition of the present invention contains a polyurethane resin, 1 to 30 parts by weight of a super absorbent polymer, and a sequestering agent, based on 100 parts by weight of the polyurethane resin.
It is blended at a ratio of 0.2 to 5 parts per super absorbent polymer.

When the amount of the super absorbent polymer is less than 1 layer, the water stopping effect of watercolor moisture (perhaps due to the addition of J) is slight, and when it is greater than 30 layers, the physical performance decreases. Therefore, it is not desirable.

The compounding value of sequestering agent is 0 for super absorbent polymer.
．． If the amount is less than 2 parts by weight, the effect of imparting long-term swelling properties will be reduced, which is not preferable, and if it is more than 5,000 parts by weight, the water resistance will decrease, which is not preferable.

Super absorbent polymers can be mixed into polyurethane resins at the stage of pelletizing the polymer after polymerization, or at the stage of molding pellets. Furthermore, polyurethane resins obtained by bulk polymerization can be mixed with solvent When a solution obtained by dissolving in water or by solution polymerization is used as it is in a solution state, it can also be mixed into the solution.

When the urethane sealant of the present invention is used, it does not matter whether it is used in a square shape or an irregular shape. That is, when the cross-sectional dimensions of the filling area (joint) are approximately constant, the composition of the present invention may be cured and molded into a regular shape, and this may be pressed into the filling area to prevent water leakage. If the cross-sectional dimensions of the filler are not constant, the composition of the present invention may be filled into the filling location and cured and swelled there to prevent water leakage. The water-absorbing polyurethane resin composition of the present invention can also be used as a foam.

The water-absorbing polyurethane composition of the present invention does not reduce water absorption swelling due to salts contained in rainwater etc. of the super-absorbent polymer mixed with the polyurethane resin, especially -1-2 valent metal ions, and can quickly form a high-grade material. suitable for

Even if the sealing material made of the water-absorbing polyurethane resin composition of the present invention peels off from the surface to which it is adhered, it absorbs water and swells in a short time when rainwater etc. enters, blocking the voids created by the peeling. It can prevent the infiltration of water, etc., and maintains water leakage prevention performance for a long time.

Therefore, the sealing material made of the polyurethane resin composition of the present invention can be used, for example, to stop water between segments in tunnel construction, to stop water at humid pipe connections, to stop water in gaps between outer wall panels of buildings, etc.
Useful for backings to prevent water leakage, etc.

In addition, the use of soft polyurethane foam provides excellent water absorbency and does not deteriorate in performance even in hard water, making it suitable for cosmetics and office supplies.
When semi-rigid foam is used, it has good sweat and moisture absorption properties and is therefore suitable for cosmetic products, office supplies, fittings, building materials, synthetic lumber, etc.

The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, the number of copies in the examples is expressed in parts by weight.

Test method Water leakage test: Segments were assembled and the joints of the segments were filled with sealing material. If water leakage was observed, it was determined that the water leaked, and if the water stopped, it was determined that the water had stopped.

Lung swelling rate: The percentage increase in chamber volume after immersing the cured product in tap water for 5 days is not shown.

Example 1 A urethane polymer containing terminal incyanate groups was produced by reacting 1 mol of triol with an average molecular weight of 13,000 obtained by adding propylene oxide (t) to glycerin and 8 mol of triene diisocyanate at 80°C without stirring. .

To 100 parts of the urethane prepolymer, super absorbent polymer (Sumikagel [F] 5-50, average particle size 20μ,
Add 15 parts of Sumima Kagaku Kogyo@, 80 parts of bentonite, 20 parts of calcium carbonate, 10 parts of ethylenediaminetetraacetic acid, and 20 parts of a liquid curing agent containing 40% methylenebisorthochloroaniline and leave it in the atmosphere at 25°C. and completely cured. The swelling ratio of the obtained cured product was measured to be 75%, and a water leakage test was conducted on the obtained cured product, and it was found to be watertight.

Example 2 A super absorbent polymer (Aqua Keep [F] 10 Si (
, average particle size 20 μ, Iron and Chemical Industry Division) 5 parts, Hentona・
(40 parts of calcium carbonate, 60 parts of ethylenediaminetetraacetic acid, 10 parts of ethylenediaminetetraacetic acid, liquid curing agent (propylene oxide added to propylene glycol, average molecular weight 100)
05 parts of dibutyltin dilaurate as a catalyst were added, and the mixture was left to stand in the atmosphere at 25°C to completely cure. /When the swelling ratio of the obtained cured product was measured, it was 62% torn. When a water leakage test was conducted on this product, water stopped.

Comparative Example 1 100 parts of the urethane prepolymer obtained in Example 1, 5 parts of Sumikagel qρS-5O (average particle size 20μ, manufactured by Sumima Kagaku Kogyo), 80 parts of hentonite, 20 parts of calcium carbonate, the same as used in Example 1. Add 20 parts of hardening agent and 25°C
It was left in the atmosphere to completely harden. The swelling ratio a of the obtained cured product was measured and found to be 42%. When we conducted a water leakage test on this item, water leakage was found in some parts.

Comparative Example 2 100 parts of the urethane prepolymer obtained in Example 1, 6 parts of Aqua Keep (R, 10S H (manufactured by Seitetsu Kagaku Kogyo Co., Ltd., with an average particle size of 20 μm), 40 parts of hentonite, and 6 parts of calcium carbonate.
0 parts, Example 2 It was left in the atmosphere at 2° C. to completely cure.

When the swelling ratio of the obtained cured product was measured, it was 32.

When we conducted a water leakage test on this item, water leakage was found in some areas6.

Claims (3)

[Claims] (1) A water-absorbing polyurethane resin composition comprising as essential components a polyurethane resin forming material, a superabsorbent polymer, and a sequestering agent. (2) The water-absorbing polyurethane resin composition according to claim 1, wherein the superabsorbent fraction is a polymer electrolyte containing a carboxylic acid and/or a salt thereof; (3) The water-absorbing polyurethane resin according to claim 1, wherein the sequestering agent is at least one compound selected from ethylenecyaminetetoacetate and its gold if4 tliii, tripolyphosphate sorta, and birophosphate sorta. Composition.