JP3089041B2 - Water absorbent resin material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-absorbent resin material useful in the fields of sanitary materials, agriculture, civil engineering, construction, industrial materials and medical materials.

[0002]

2. Description of the Related Art In recent years, the development of superabsorbent resins has been remarkable, and their types are starch-acrylate graft polymers, acrylic acid polymers, acrylic acid-acrylic acid ester copolymers, acrylic acid-vinyl alcohol copolymers. Coalescing,
Acrylic acid-acrylamide copolymer, isobutylene-
Various products such as a maleic anhydride copolymer are commercially available. Most of these have a crosslinked structure,
Since it is insoluble in organic solvents and water and is not thermoplastic, the main forms of the product are granules, fine powders, spheres, fibers and the like. Recently, some polyurethane-based water-absorbent resins are of the organic solvent solution type. In this case, however, there is a danger of toxicity, flammability, explosion, etc. due to the solvent, which adversely affects the working environment and the natural environment. Effect. Furthermore, it is very difficult to control the reaction during the production thereof, and there is a high risk of thickening or gelling even during long-term storage.
As described above, conventional water-absorbent resins are not liquid and can be used with good workability. Therefore, the use of these resins for imparting hydrophilicity to various substrates, waterproofing, antifogging, and the like is substantially impossible. Was impossible.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional product and provides a water-absorbent resin material which can be used stably and durably as a liquid as an organic solvent solution, aqueous solution or aqueous dispersion. The task is to provide.

[0004]

The water absorbing resin material of the present invention is a reaction product of an active hydrogen compound having two or more groups having active hydrogen and a polyisocyanate compound having two or more isocyanate groups. A resin material obtained by reacting a blocking agent with a prepolymer having an active isocyanate group at a terminal to mask the terminal isocyanate group, and becomes a water-insoluble and water-absorbing resin by heating. . The active hydrogen compound may be a single compound or a combination of two or more compounds, of which 50% by weight or more has an average molecular weight of 2000 to 100000 having two or more hydroxyl groups. And the water-soluble polyalkylene oxide-based polyol is characterized in that ethylene oxide units are contained in an amount of 50% by weight or more in the total amount of the active hydrogen compounds.

[0005] Such a water-absorbent resin material of the present invention becomes a stable solution and dispersion with an organic solvent or water, and after treating the workpiece, evaporating the organic solvent or water, By heating, the blocking agent is dissociated and the isocyanate group is released, whereby the prepolymer is reticulated by the reaction of the active isocyanate group with moisture in the air and the crosslinking reaction by self-polymerization, and a large amount of water is removed. It absorbs and swells, but can become a water-absorbing resin that does not dissolve in water.

That is, since the water-absorbent resin material of the present invention is a block in which a prepolymer having an active isocyanate group is stabilized, there is no danger of thickening or gelling of the solution, and the reaction is easily carried out. Therefore, various reaction products having different water absorption capacities can be easily synthesized, and can be stored in a stable solution state for a long period of time. In addition, the water-absorbent resin material of the present invention can be used as an organic solvent solution, aqueous solution or aqueous dispersion with very good operability, and from such an organic solvent solution or aqueous solution, at a low temperature, if necessary, under reduced pressure. Organic solvent and water can be removed to obtain a resin solid having a melting point.

Accordingly, the resin material of the present invention can be used for wood products,
Rubber or plastic, ceramics, metal products, glass, textiles, paper, film, etc. can be coated or impregnated with a solution or a uniform dispersion to form a water-absorbing coating or structure on their surface. It can also be used by mixing with paints and various liquid polymers. Further, it can be used in the form of a film, or taken out as a powder from a solution, and can be used as it is or mixed and dispersed in various media.

In the present invention, A) a water-soluble polyalkylene oxide-based polyol having an average molecular weight of 2,000 to 100,000 having two or more hydroxyl groups is used as a main component of the active hydrogen compound.
B) Molecular weight 100 having two or more groups having active hydrogen
0 or less, and C) a hydrophobic oligomer having a molecular weight of 1,000 to 5,000 having two or more hydroxyl groups may be used in combination.
It is preferable that the amount of the component (B) is not more than 10 parts by weight and the amount of the component (C) is not more than 90 parts by weight, based on 100 parts by weight of the component (A). It is important that it be contained in more than%.

The component (A) has an average molecular weight of 2,000 to 100.
000, a water-soluble resin (polyalkylene oxide-based polyol) having two or more hydroxyl groups per molecule may be used, but it is particularly preferable to use one having an average molecular weight of 4,000 or more. Ethylene oxide homopolymer, ethylene oxide And a propylene oxide copolymer or a copolymer of ethylene oxide and butylene oxide can be used, and other copolymer components may be contained as long as water solubility is not lost. Moreover, even if these are used alone,
One or more kinds may be used in combination, and it is possible to adjust the properties of the resulting resin, for example, the magnification of water absorption, by selecting an appropriate polymer.

When the molecular weight of the polyalkylene oxide-based polyol is smaller than 2,000, the crosslinked structure becomes fine and the ratio of hydrophilic groups decreases, so that the water absorption of the resin often decreases. And the flexibility of the resin becomes poor, and the resin tends to become brittle.

Next, as the low molecular weight compound of the component B),
Compounds having two or more active hydrogens reactive with isocyanate groups, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol,
Glycols such as 1,6-hexanediol, neopentyl glycol, diethylene glycol and triethylene glycol; polyalkylene polyamines such as polyethylene polyamine, polypropylene polyamine and polybutylene polyamine; and trimethylolpropane, glycerin, pentaerythritol and sorbitol Polyhydric alcohols; amino alcohols such as monoethanolamine, diethanolamine and triethanolamine; ethylene oxide or propylene oxide adducts of the above compounds having a molecular weight of 1000 or less, or N-methyl-N, N-diethanolamine, N- Ethyl-N, N-
Diethanolamine and salts thereof with acids, or quaternary products thereof; dimethylolpropionic acid, dihydroxyethyl terephthalate sulphonate, taurine and basic substances such as sodium hydroxide, potassium hydroxide, ammonia and lower amines Any of neutralized products and the like can be used, and these may be used alone or as a mixture of two or more. The component B) is used as a chain extender for the crosslinking reaction of the resin and the adjustment of the molecular weight, and is used mainly for the purpose of controlling the solution viscosity in addition to the water absorbing performance. The amount of the component (B) to be used is not more than 10 parts by weight based on 100 parts by weight of the component (A).

As the hydrophobic oligomer of the component C), polyether polyol, polyester polyol, acrylic polyol and the like are preferably used, and these may be used alone or in combination of two or more.

Polyether polyols include homopolymers and copolymers containing propylene oxide, tetrahydrofuran and the like as monomers. Polyester polyols include ethylene glycol, diethylene glycol, 1,4-
Polyhydric alcohols such as butanediol, neopentyl glycol, 1,6-hexanediol, trimethylolpropane, and glycerin, and polyhydric carboxylic acids such as adipic acid, succinic acid, phthalic acid, maleic acid, and pyromellitic acid or the like And a linear or branched condensation product obtained by dehydration condensation from an anhydride, a ring-opened polymer of a cyclic ester compound, a condensate of a hydroxy acid, and the like.

The component (C) has the function of increasing the film strength and the use of components similar to the workpiece, thereby increasing the affinity for the workpiece and increasing the adhesion and adhesion. However, as the proportion of the amount used increases, the solubility of the resulting resin material of the present invention in water decreases, and sometimes the aqueous solution does not become an aqueous solution, or the water absorption capacity of the water-absorbent resin obtained by heating, A case where desired properties cannot be obtained due to a low water absorption rate is likely to occur. Therefore, the use amount of the component (C) is preferably 90 parts by weight or less, particularly preferably 40 parts by weight or less based on 100 parts by weight of the component (A). A) The proportion of the hydrophobic group in the polyalkylene oxide of the component is large,
When a sufficient crosslinked structure is generated by the component (B), the component (C) may not be contained.

Next, the polyisocyanate compound used in the present invention contains an isocyanate group (-NCO) in the same molecule.
Compounds having two or more groups, for example, 1,3-propane diisocyanate, 1,4-butane diisocyanate, 1,6-hexane diisocyanate, decane diisocyanate, trimethylhexamethylene diisocyanate Isocyanate,
Dicyclohexylmethane diisocyanate, isophorone diisocyanate, 2,4- or 2,6-tolylene diisocyanate or an isomer mixture thereof, 4,4'-diphenylmethane diisocyanate, naphthalene-1,4-diisocyanate , 1-methyl-2,4,6-triisocyanate, naphthalene
-1,3,7-triisocyanate, triphenylmethane-4,
4 ', 4 "-triisocyanate or trimer of tolylene diisocyanate (Dismodur L), polymethylene polyphenyl isocyanate (manufactured by Upjohn Co., Ltd.) and the like. Two or more kinds may be used in combination.

The amount of the polyisocyanate compound used in this reaction varies depending on the type of each reaction composition, but usually contains active hydrogen contained in the active hydrogen compounds {A), B) and C). Preferably, the ratio of the total molar equivalents of the groups to the molar equivalents of the isocyanate groups of the polyisocyanate compound is in the range of 1: 1.1 to 1: 3.

The reaction between the active hydrogen compound and the polyisocyanate compound is preferably carried out in an anhydrous state, if necessary, in an inert gas atmosphere. The reaction temperature is 50 ° C. to 150 ° C. and the NCO% is Perform until the theoretical value is reached.

The order of the reaction between the active hydrogen compound and the polyisocyanate compound is not particularly limited. Even if all the active hydrogen compounds are mixed and then reacted with the polyisocyanate compound, the active hydrogen compound such as A) B ) C)
Each of the components may be reacted with the polyisocyanate compound in a stepwise manner, and other appropriate methods can be used.

These reactions may be carried out without a solvent. However, depending on the viscosity of the resulting prepolymer, an anhydrous solvent may be used in the reaction system during resin production or used for dilution after the reaction. You may. The solvent may be used alone or in combination depending on the solubility of the resin, and any solvent which is inert to the isocyanate group and dissolves the prepolymer can be used. Examples of such a solvent include N, N
-Dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, hexamethylenephosphoramide, tetrahydrofuran, acetonitrile, dioxane, methylene chloride, ethanedichloride, chloroform, trichloroethylene, perchlorethylene, Examples include 1,1,1-trichloroethane, benzene, toluene, xylene, a chlorofluorocarbon-based solvent, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, ethyl acetate, propyl acetate, butyl acetate, and butyl propionate. In addition, triethylamine,
Catalysts for tertiary amines such as pentamethyldiethylenetriamine, dimethylbenzylamine, tetraethyldiamine, triethylenediamine, morpholine derivatives, piperazine derivatives, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diacetate, triphenyltin acetate, stannasoctoate, etc. The reaction can also be promoted by adding a small amount as

Since the prepolymer thus synthesized has an active isocyanate group, it reacts with moisture in the air or an active hydrogen compound, or undergoes self-polymerization by
Since the thickening and gelation are apt to occur, it is stabilized in the state of an aqueous solution or an organic solvent solution by reacting with an E) blocking agent to protect the isocyanate group.

Examples of the isocyanate group blocking agent include phenols, cresols, trimethylphenols, alcohols, active methylene compounds such as ethyl acetoacetate, acetylacetone, diethylmalonate, succinimide, Lactams such as ε-caprolactam, oximes such as butanone oxime and cyclohexanone oxime, bisulfites, aliphatic mercaptans such as methyl mercaptan, ethyl mercaptan and t-butyl mercaptan, imidazoles such as 2-methylimidazole and benzimidazole And the like, and these may be used alone or in combination of two or more.

When the isocyanate group is reacted with the blocking agent, any solvent that may be used when synthesizing the above-mentioned prepolymer can be used. In the case of the reaction, a hydrophilic solvent such as methanol, ethanol, isopropanol and water may be used. The amount of the blocking agent used is preferably a molar ratio of 1: 1 to 1: 2 with respect to the molar equivalent of the isocyanate group of the prepolymer.

The resin material of the present invention obtained by the above reaction is obtained as a solid or viscous substance, various organic solvent solutions, a solution in a mixed system of water and an organic solvent, or a uniform dispersion. Further, the solvent is removed from the solvent solution at a temperature at which the blocking agent does not dissociate (for example, 70 ° C. or lower), if necessary, under reduced pressure, and the obtained dry solid is converted into a block, film, or powder. It can be processed into various applied substrates.

The resin material of the present invention is usually used at 80 ° C. to 180 ° C.
The active isocyanate group is regenerated by heating to ℃ to dissociate the blocking agent, which causes cross-linking reaction and bonding due to the reaction with the moisture in the air and the substrate and self-polymerization, and the polymer is reticulated. Thus, a water-absorbing resin that absorbs water and swells but does not dissolve in water can be obtained. Furthermore, the durability of the resin can be significantly improved by adding, for example, a hindered phenol-based, sulfur-based, phosphorus-based antioxidant, a light-resistant stabilizer, or the like, according to the purpose. . Further, in order to accelerate the dissociation of the blocking agent and the crosslinking reaction of the isocyanate, a catalyst such as sodium methylate, tertiary amines, and organotin compounds can be used in combination.

The water absorption of the resin obtained by dissociating the blocking agent of the resin material of the present invention is about 3 to 50 times in fresh water, and sodium chloride, potassium chloride, magnesium chloride, calcium chloride , Aluminum chloride,
In addition to aqueous solutions of salts such as ammonium chloride, urea aqueous solutions can effectively absorb and swell. Types of salt,
Depending on the concentration, there is a case where the water absorption rate is slightly reduced as compared with the case of fresh water, but the desired effect can be obtained almost unchanged.

Furthermore, as a remarkable performance, the water-absorbing resin obtained from the resin material of the present invention can be used at a room temperature at a certain high concentration of an aqueous solution of a mineral acid, such as sulfuric acid or phosphoric acid, at a high water absorption capacity. It was found to be stably absorbed and retained. In contrast, most of the water-absorbent resins currently on the market have electrolyte ionic groups in the molecule, so that the water absorbency of salts for aqueous solutions is significantly lower than that of fresh water, such as sulfuric acid and phosphoric acid. It shows almost no water absorption for highly concentrated aqueous solutions of mineral acids.

As described above, the water-absorbent resin material of the present invention
It has solubility or uniform dispersibility in organic solvents and water, and after being applied to a substrate or the like, it can be turned into a water-absorbent resin that is insoluble in water and rich in water by heating after application. It is excellent in film-forming properties and exhibits high water absorption to high-concentration aqueous salt solutions and aqueous solutions of sulfuric acid, phosphoric acid and the like, in addition to fresh water, so that it can be effectively used for a very wide range of applications.

[0028]

Embodiments of the present invention will be described below in detail, but the present invention is not limited to these embodiments. In addition,
In Examples, unless otherwise specified, parts and% indicate parts by weight and% by weight, respectively. Further, the water absorption ratio in the examples shows the following values. [Water absorption] The film whose absolute dry weight (Wo) was measured
After being immersed in tap water at 5 ° C. for 24 hours, the weight (Ws) of the swollen film is weighed to obtain a water absorption capacity (M).
Is calculated according to the formula {M (%) = (Ws / Wo) × 100}. [Method of preparing water-absorbent resin film] The solution or dispersion of the water-absorbent resin material obtained in the example was poured on a Teflon plate, formed into a uniform layer with a bar coater, and weighed in a blower oven at 70 ° C to a constant weight. Drying until reaching (about 3 hours) to make a 0.3 mm thick dried film, and further reheating this film for about 10 minutes at 100-180 ° C. depending on the type of blocking agent. The film was tested for water absorption.

Example 1 An average molecular weight of 800, which was sufficiently dehydrated by drying under reduced pressure, respectively.
100 parts of a polyethylene oxide-polypropylene oxide copolymer having a polyethylene oxide content of 85% and a polypropylene oxide having an average molecular weight of 3000.
8 parts and 0.58 parts of glycerin were added to acetonitrile 735
The mixture was completely dissolved in a nitrogen atmosphere at 30 ° C to 40 ° C. In this solution, triethylenediamine 0.
After adding 2 parts, and then adding 6.85 parts of tolylene diisocyanate and reacting at 50 ° C. to 70 ° C. for 3 hours, the isocyanate value (NCO%) of the reaction system was measured, and the value was calculated as the theoretical value. After confirming that the value had reached the value or less, 3.6 parts of diethyl malonate was added and reacted at about 70 ° C. for 2 hours.
In an infrared absorption spectrum method (hereinafter referred to as an IR spectrum), a reaction system based on an isocyanate group was used.
It was confirmed that the absorption at 50 cm ^-1 had disappeared, and the solid content was 15%.
Was obtained. This resin solution was formed into a film by the method described above, and a physical property test was performed. Table 1 shows the results.

Example 2 An average molecular weight of 200, which was sufficiently dehydrated by drying under reduced pressure, respectively.
50 polyethylene oxide and an average molecular weight of 150
Polyethylene oxide-polypropylene oxide copolymer 50 having a polyethylene oxide content of 80%
Parts, polybutylene oxide having an average molecular weight of 2000, 5.83
Parts and 1.17 parts of a propylene oxide adduct of trimethylolpropane having an average molecular weight of 400 were added to ethylene dichloride 6
37 parts were completely dissolved in a nitrogen atmosphere at 30 ° C to 40 ° C. To this solution, 0.05 parts of dibutyltin dioctoate was added as a catalyst, and 4.08 parts of isophorone diisocyanate was added. The mixture was reacted at 50 ° C. to 65 ° C. for 2 hours, and then the isocyanate value of the reaction system ( NCO%), and after confirming that the value has reached the theoretical value or less,
Add 1.48 parts of ε-caprolactam and add another 2 at the same temperature.
Allowed to react for hours. From the IR spectrum, it was confirmed that the absorption at 2250 cm ^-1 based on the isocyanate group had disappeared from the reaction system, and a uniform water-absorbent resin solution having a solid content of 15% was obtained. This resin solution was formed into a film in the same manner as in Example 1,
The physical property test was performed. Table 1 shows the results.

Example 3 An average molecular weight of 200, which was sufficiently dehydrated by drying under reduced pressure, respectively.
100 parts of polyethylene oxide, and 10 parts of a polyester diol having an average molecular weight of 4000 comprising ethylene glycol, diethylene glycol and adipic acid,
1.5 parts of a propylene oxide adduct of glycerin having an average molecular weight of 600 was completely dissolved in 657 parts of dimethyl sulfoxide at 30 ° C. to 40 ° C. in a nitrogen atmosphere. To this solution was added 0.2 parts of triethylenediamine as a catalyst, and then 3.0 parts of xylylene diisocyanate. The mixture was reacted at 50 ° C. to 70 ° C. for 3 hours, and then the isocyanate value of the reaction system (NCO %), And after confirming that the value has reached the theoretical value or less, ethyl acetoacetate 1.
5 parts were added, and the mixture was further reacted at 60 to 70 ° C. for 2 hours. From the IR spectrum, it was confirmed that the absorption at 2250 cm ^-1 based on the isocyanate group had disappeared from the reaction system, and a uniform water-absorbent resin solution having a solid content of 15% was obtained. This resin solution was formed into a film in the same manner as in Example 1, and its physical properties were tested. Table 1 shows the results.

Example 4 An average molecular weight of 500, which was sufficiently dehydrated by drying under reduced pressure, respectively.
30 polyethylene oxide and an average molecular weight of 15
Polyethylene oxide-polypropylene oxide copolymer 70 having a polyethylene oxide content of 80%
Parts and polypropylene oxide 1 having an average molecular weight of 4000
0.5 part was added to 650 parts of toluene at 50 ° C. in a nitrogen atmosphere.
At ６０60 ° C., it was completely dissolved. To this solution, at the same temperature, 0.2 part of triethylenediamine was added as a catalyst, and then 1.4 parts of hexamethylene diisocyanate and 2.6 parts of polyisocyanate (Coronate HL) were added and reacted for 3 hours. After that, the isocyanate value of the reaction system (NCO%)
Was measured, and after confirming that the value had reached the theoretical value or less, 1.03 parts of methyl ethyl ketoxime was added, and about 70
The reaction was further performed at 2 ° C. for 2 hours. In the IR spectrum,
It was confirmed from the reaction system that the absorption at 2250 cm ^-1 based on the isocyanate group had disappeared, and a uniform water-absorbent resin solution having a solid content of 15% was obtained. From this reaction system, 70 ° C to 80 ° C
After the toluene was distilled off under reduced pressure, 650 g of water was added to the obtained reaction product and dissolved under heating to obtain a uniform resin aqueous solution having a solid content of 15%. This was formed into a film in the same manner as in Example 1, and a physical property test was performed. Table 1 shows the results.

Example 5 An average molecular weight of 500, which was sufficiently dehydrated by drying under reduced pressure, respectively.
50 parts of polyethylene oxide, average molecular weight 200
50 parts of polyethylene oxide, average molecular weight 200
3.5 parts of polylactone and 0.7 parts of a propylene oxide adduct of trimethylolpropane having an average molecular weight of 400 were added to 606 parts of acetone in a nitrogen atmosphere at 40 ° C to 50 ° C.
Was completely dissolved. To this solution was added 0.3 part of dimethylbenzylamine as a catalyst, then 2.07 parts of xylylene diisocyanate, and the mixture was reacted at 40 ° C. to 50 ° C. for 3 hours. (NCO%) was measured, and after confirming that this value had reached the theoretical value or less, 0.79 parts of acetylacetone was added, and 5
The reaction was further performed at 0 ° C to 60 ° C for 2 hours. In the IR spectrum, 22 based on the isocyanate group was obtained from the reaction system.
It was confirmed that the absorption at 50 cm ^-1 had disappeared, and the solid content was 15%.
Was obtained. This was formed into a film in the same manner as in Example 1, and a physical property test was performed. Table 1 shows the results.

Example 6 Each of them was sufficiently dehydrated by drying under reduced pressure.
000 polyethylene oxide 30 parts, average molecular weight 10
70 parts of polyethylene oxide, 7.3 parts of a polyester diol having an average molecular weight of 2000 consisting of neopentyl glycol and adipic acid, and 0.3 parts of triethanolamine.
54 parts to 1039 parts N, N-dimethylacetamide
It was completely dissolved at 50 ° C. to 70 ° C. in a nitrogen atmosphere.
To this solution was added 0.05 g of dibutyltin dilaurate as a catalyst.
Parts, then diphenylmethane diisocyanate 5.
After adding 75 parts and reacting at 50 ° C to 70 ° C for 2 hours, the isocyanate value (NCO%) of the reaction system was measured, and after confirming that this value reached the theoretical value or less, ε
1.85 parts of caprolactam was added, and the mixture was further reacted at about 70 ° C. for 2 hours. In the IR spectrum, from the reaction system,
It was confirmed that the absorption at 2250 cm ^-1 based on the isocyanate group had disappeared, and a uniform water-absorbent resin solution having a solid content of 10% was obtained. This was formed into a film in the same manner as in Example 1, and a physical property test was performed. Table 1 shows the results.

Example 7 The average molecular weight was 100, which was sufficiently dehydrated by drying under reduced pressure.
000 polyethylene oxide, 20 parts, average molecular weight 20
80 parts of polyethylene oxide having an average molecular weight of 40
8.4 parts of polybutylene oxide with an average molecular weight of 6
1.26 parts of the propylene oxide adduct of trimethylolpropane No. 00 were completely dissolved in 639 parts of acetonitrile at 50 ° C to 60 ° C in a nitrogen atmosphere. To this solution, 0.05 parts of dibutyltin diacetate was added as a catalyst, 2.22 parts of 1,6-hexanediisocyanate was further added, and the mixture was reacted at 50 to 60 ° C. for 3 hours. The isocyanate value (NCO%) of the system was measured, and after confirming that this value had reached the theoretical value or less, the internal temperature was lowered to 20 ° C. The acidic sodium sulfite 0.9g was dissolved in water 20g, was added to the reaction system at 20 ° C. to 30 ° C., after reacting for 3 hours, by IR spectrum, from the reaction system, 2250 cm-based isocyanate group ^- It was confirmed that the absorption of ¹ had disappeared, and a uniform water-absorbent resin solution having a solid content of 10% was obtained. This was formed into a film in the same manner as in Example 1, and a physical property test was performed. Table 1 shows the results.

Comparative Example 1 An average molecular weight of 800, which was sufficiently dehydrated by drying under reduced pressure, respectively.
100 minutes of a polyethylene oxide-polypropylene oxide copolymer having a polyethylene oxide content of 85% and a polypropylene oxide 75 having an average molecular weight of 3000.
Parts and 1.15 parts of glycerin were added to acetonitrile 1117
The mixture was completely dissolved in a nitrogen atmosphere at 30 ° C to 40 ° C. In this solution, triethylenediamine 0.
After adding 3 parts, then adding 13.7 parts of tolylene diisocyanate and reacting at 50 ° C to 70 ° C for 3 hours,
The isocyanate value (NCO%) of the reaction system was measured, and after confirming that this value had reached the theoretical value or less, 7.2 parts of diethyl malonate was added and reacted at about 70 ° C. for 2 hours. The IR spectrum confirmed that the absorption at 2250 cm ^-1 based on the isocyanate group had disappeared from the reaction system, and a uniform water-absorbent resin solution having a solid content of 15% was obtained. This was formed into a film in the same manner as in Example 1, and a physical property test was performed. Table 1 shows the results.

[0037]

[Table 1]

Note 1) Appearance of Examples 1 to 7
The properties before forming the film by heating are shown, and the properties of the product are shown for the comparative examples. Note 2) The solubility was tested for Examples 1 to 7 by the method described in “Method of Making Water Absorbent Resin Film” on a film that was only dried in an oven at 70 ° C. on the way. ◎: Dissolved or uniformly dispersed in all three solvents, water, dimethylformamide and ethane dichloride. ：: Dissolved or uniformly dispersed in any of the above three solvents. ×: Dissolved or not uniformly dispersed in any solvent. Note 3) In Examples 1 to 7, the water absorption ratio was measured for a resin film obtained by the method described in "Method of Making Water Absorbent Resin Film". Note 4) The resins used in Comparative Examples 2 to 5 are as follows. Comparative Example 2: Commercial product consisting of butadiene-maleic anhydride copolymer Comparative Example 3: Commercial product consisting of starch-acrylic acid graft polymer Comparative Example 4: Commercial product consisting of crosslinked acrylic resin Comparative Example 5: Crosslinked acrylic Commercial product consisting of copolymer resin

[0039]

The water-absorbent resin material of the present invention is soluble or evenly dispersible in organic solvents and water, and is insoluble in water and rich in water absorbability by heating after application to a substrate or the like. It can be turned into a water-absorbent resin, and the resulting water-absorbent resin has excellent film-forming properties and, in addition to fresh water, exhibits excellent water absorbency against high-concentration aqueous salt solutions and aqueous solutions of sulfuric acid, phosphoric acid, etc. , Very wide fields, for example, sanitary materials such as disposable diapers, sanitary products, anti-condensation agents, antistatic properties to resins, water-absorbing and water-retaining processing agents, aqueous gel base materials, water-retaining agents for seedling transplantation, agriculture It can be effectively used as any of a horticultural soil water retention agent, a water-absorbing sealing agent, a humidity regulator and the like.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-28419 (JP, A) JP-A-56-59832 (JP, A) JP-A-57-174354 (JP, A) JP-A-56-1984 110717 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 18/10 C08G 18/48-18/50 C08G 18/66 C08G 18/80

Claims (1)

(57) [Claims] 1. A resin material which can be used in a liquid state and which is insoluble in water when heated and which can become a water-absorbing resin having a water absorption ratio of 3 to 50 times in fresh water, and having two or more groups having active hydrogen. A reaction product of a hydrogen compound and a polyisocyanate compound having two or more isocyanate groups, which is obtained by reacting a blocking agent with a prepolymer having an active isocyanate group at a terminal to mask the terminal isocyanate group. The active hydrogen compound is A) 100 parts by weight of a water-soluble polyalkylene oxide-based polyol having an average molecular weight of 2,000 to 100,000 having two or more hydroxyl groups, B)
A low-molecular weight compound having a molecular weight of 1000 or less having not more than 10 parts by weight having at least two groups having active hydrogen, and C) not more than 90 parts by weight of a hydrophobic oligomer having a molecular weight of 1000 to 5000 having at least 2 hydroxyl groups. A water-absorbent resin material, wherein the active hydrogen compound contains 50% by weight or more of ethylene oxide units in the total amount.