JP3042948B2 - Water-absorbing polyurethane gel fine particles and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to paints, coatings, resins, rubbers, elastomers, etc.
The present invention relates to water-absorbent polyurethane gel fine particles useful as a modifier that gives water wetting performance and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a cross-linked polyurethane resin excellent in water absorbency by three-dimensionally reacting polyisocyanate and polyethylene glycol has been known. Methods for applying such water absorption performance include paints, coatings,
There is a method in which a polyurethane raw material before crosslinking is blended with a resin molded product, rubber, an elastomer or the like to complete a crosslinking after forming a coating film or a molded product. However, in such a method, it is difficult to control the crosslink density, and depending on the degree of crosslinking, the compatibility of the crosslinked product with a coating film or a molded article is reduced,
Conversely, the physical properties of the coating film and the molded product may be reduced, and the range of application is limited.

As a method of solving such a problem, there is a method of producing water-absorbing polyurethane gel particles and blending them with a coating material or a molding resin. However, the conventional method of producing water-absorbing polyurethane gel particles is solid. Method of mechanically pulverizing water-absorbent polyurethane at low temperature, method of precipitating and drying water-absorbent polyurethane gel particles from aqueous emulsion, method of spray drying, and addition of poor solvent to solution-polymerized polyurethane to precipitate polyurethane in granular form And a method of filtering and drying to remove the solvent.

[0004] In these conventional methods, there is a problem that the shape of the obtained powder is irregular, and at the same time, fine water-absorbing polyurethane gel fine particles cannot be obtained, and the production cost is extremely high. There's a problem. On the other hand, a method using an inert solvent is disclosed in U.S. Pat.
525, JP-A-53-129295 and JP-A-2-38453 are known.

[0005]

The above-mentioned method is inferior in productivity and cannot be said to be a practical method. In the latter method, all special organic surfactants must be used, and some of these surfactants must be dissolved in an inert solvent which is a polymerization solvent. The problem is that the inert solvent that can be used is limited.

In addition, there is a problem that a surfactant is unavoidably mixed into the resulting water-absorbing polyurethane gel particles, which adversely affects the physical properties of the polyurethane gel particles. Further, strong stirring is necessary for stabilizing the emulsification (suspension) of the reactants, and if the stirring is insufficient, the low softening point or low hardness water-absorbent polyurethane gel particles are polymerized in the dispersion. There is a disadvantage that the water-absorbing polyurethane gel particles are fused together in the step of agglomerating the polyurethane dispersions and powdering from the dispersion and the particles are coarsened, so that the production cannot be performed. Accordingly, an object of the present invention is to solve the above-mentioned conventional drawbacks and to easily provide water-absorbent polyurethane gel fine particles applicable to a wide range of applications.

[0007]

The above object is achieved by the present invention described below. That is, the present invention includes at least Izu
Re or it is one of the compounds 3 or more functional groups, a three-dimensionally crosslinked water-absorbing polyurethane gel particles consisting of a compound having at least polyethylene oxide group and an active hydrogen and polyisocyanate compounds, surface polyurea colloid non of the fine particles Water-absorbent polyurethane gel fine particles coated with polyurea colloid particles precipitated from an aqueous solvent solution (hereinafter simply referred to as polyurea colloid solution), and a method for producing the same.

[0008]

The present inventors have found that a polyurea colloid solution can easily emulsify a polyisocyanate compound and a compound having a polyethylene oxide group and active hydrogen, which are raw materials for producing a polyurethane gel, in an inert solvent and into fine particles, and In this state, the polyisocyanate compound and the compound having a polyethylene oxide group and active hydrogen undergo a polymerization reaction to produce three-dimensionally crosslinked water-absorbent polyurethane fine particles, and the polyurea colloid deposited from the polyurea colloid solution around the generated fine particles. The present invention was completed by finding that the fine particles were uniformly coated with the above-mentioned colloid particles in a state where the particles were uniformly attached and the fine particles were separated from the dispersion solvent.

Furthermore, in the present invention, a significant increase in viscosity usually occurs during the process of synthesizing the water-absorbing polyurethane gel fine particles. However, when the fine particles are synthesized in the presence of a polyurea colloid solution, a significant increase in the viscosity occurs during the synthesis process. In addition, the resulting water-absorbent polyurethane gel fine particles do not aggregate, and maintain excellent dispersion stability. This action is a fundamentally different action from conventionally known organic emulsifiers and dispersion stabilizers.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. The water-absorbent polyurethane gel fine particles of the present invention have at least one compound of 3
Is functional or more, the polyisocyanate compound and a compound having at least polyethylene oxide group and an active hydrogen, in the presence of polyurea colloid solution as an emulsifier, obtained by emulsion polymerization in an inert solvent. The water-absorbent polyurethane gel fine particles thus obtained are three-dimensionally crosslinked water-absorbent polyurethane gel fine particles, wherein the surface of the fine particles is coated with polyurea colloid particles precipitated from a polyurea colloid solution. .

[0011] water-absorbing polyurethane gel particles of the present invention has obtained by the above methods, the preferred method is charged polyurea colloid solution jacketed synthesis reactor equipped with stirrer and emulsifier, at least one of the reduction in the
Compound is trifunctional or higher, in an inert solvent solution of a polyisocyanate compound and a compound having at least a polyethylene oxide group with an active hydrogen is added and emulsified, reacted with these synthetic raw material for synthesizing a water soluble polyurethane gel microparticles A method and a polyisocyanate compound, at least one of which is trifunctional or more, and a compound having at least a polyethylene oxide group and active hydrogen, respectively,
A method of emulsifying in an inert solvent in the presence of a polyurea colloid solution and reacting them is exemplified.

The synthesis temperature is not particularly limited, but the preferred temperature is 40 ° C to 120 ° C. The amount of the polyurea colloid solution used during the synthesis as a solid content is 100 parts each of a polyisocyanate compound and a compound having at least a polyethylene oxide group and active hydrogen.
0.5 parts by weight or more can be used per part by weight,
Preferably it is 1.0 to 20 parts by weight. If the amount is less than 0.5 part by weight, the emulsifiability of the raw material is insufficient, large aggregates of the water-absorbing polyurethane fine particles are generated in the synthesis process, and it is difficult to obtain a desired fine polymer dispersion. On the other hand, when the amount exceeds 20 parts by weight, there is no problem in the emulsifiability of the raw material of polyurethane, and a dispersion of the water-absorbing polyurethane fine particles can be produced. As the concentration of the polyisocyanate compound and the compound having at least the polyethylene oxide group and active hydrogen in the inert solvent becomes smaller, the smaller the particle size, the easier it is to obtain a smaller particle size. The preferred concentration is 20 to 70 parts by weight from the viewpoint of productivity.

Examples of the polyisocyanate compound used for synthesizing the water-absorbent polyurethane gel fine particles of the present invention include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate,
Meta-xylene diisocyanate, 1,6-hexamethylene diisocyanate, lysine diisocyanate, 4,4
'-Methylenebis (cyclohexyl isocyanate),
Methylcyclohexane-2,4- (or -2,6-)-
Those having two isocyanate groups such as diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, trimethylhexamethylene diisocyanate, and dimer acid diisocyanate are exemplified.

Further, those compounds having polyfunctional isocyanate groups such as isocyanurate form, buret form, adduct form and polymeric form, for example,
4,4 ′, 4 ″ -triphenylmethane triisocyanate, cyclic trimer of 2,4-tolylene diisocyanate,
Cyclic trimer of 2,6-tolylene diisocyanate, mixed 3 moles of cyclic trimer of 2,4- and 2,6-tolylene diisocyanate, diphenylmethane-4,4'-
Reaction product of trimer of diisocyanate, 3 moles of diphenylmethane-4,4'-diisocyanate and 1 mole of trimethylolpropane, 3 moles of 2,4-tolylenediisocyanate and 1 mole of trimethylolpropane Reaction product of 3 mol of 2,6-tolylene diisocyanate with 1 mol of trimethylolpropane Reaction product of 3 mol of 2,4-tolylene diisocyanate with 1 mol of trimethylolethane Reaction product of 3 moles of 2,6-tolylene diisocyanate with 1 mole of trimethylolethane, 3 moles of 2,4
And the reaction products of 2,6-tolylene diisocyanate with 1 mol of trimethylolpropane, and the like, and these polyisocyanates are converted into methanol, ethanol, phenol, cresol, ε-caprolactam, methyl ethyl ketone oxime, acetone oxime, N, A compound obtained by reacting a compound having one active hydrogen in the molecule, such as N-dimethylhydroxyamine, diethyl malonate, and acetylacetone, with a part or all of the isocyanate groups of the polyisocyanate compound can be used.

The most preferred examples of the compound having at least a polyethylene oxide group and active hydrogen to be reacted with the polyisocyanate are polyethylene glycol and a copolymer of polyethylene oxide and another active hydrogen-containing compound. Having an average molecular weight of 500 to
It is about 4,000. In addition, for the purpose of adjusting the water absorption ratio of the resulting water-absorbent gel fine particles, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, octanediol, neopentyl Glycol, glycerin, trimethylolpropane, hexanetriol, triethanolamine, pentaerythritol, ethylenediamine, propylenediamine, butylenediamine, 1,4-benzenethiol, sorbitol, polypropylene glycol, polyethylene adipate, polybutylene adipate, polytetramethylene glycol, Polyhexamethylene adipate, poly-ε-caprolactone, polyhexamethylene carbonate, hydrogenated dimer polyol, castor polyol, poly Refin-based polyols, polyethylene glycol, copolymers of ethylene oxide and propylene oxide, copolymers of ethylene oxide and bisphenol A, homopolymers, mixtures and copolymers of ethylene oxide and / or propylene oxide with tetrahydrofuran and glycerin adducts A product that reacts with the polyisocyanate compound, such as a product, can also be used in combination.

The type, amount and ratio of the polyisocyanate compound and the compound having at least a polyethylene oxide group and active hydrogen are determined by the water absorption capacity required for the resulting water-absorbent polyurethane gel fine particles. Is required to be trifunctional or more. For example, when the polyisocyanate is bifunctional, the compound having at least a polyethylene oxide group and active hydrogen is trifunctional or more, and when the compound having at least a polyethylene oxide group and active hydrogen is bifunctional, , Polyisocyanate is 3
Functionality or more is required, and both components may be trifunctional or more. The NCO / OH ratio is determined depending on the compound used and the performance required for the product, and is preferably in the range of 0.5 to 1.2.

The inert solvent used in the reaction between the above two compounds and forming the continuous phase of the resulting water-absorbent polyurethane gel fine particle dispersion is substantially a non-solvent for the polyurethane to be produced and contains active hydrogen. It does not. Examples include pentane, hexane, heptane, octane,
Decane, petroleum ether, petroleum benzine, ligroin, petroleum spirit, cyclohexane, methylcyclohexane, toluene, hydrocarbons such as xylene, alone or a mixture of dimethylpolysiloxane, etc., and these inert solvents, the inert solvent and From the viewpoint of productivity in the separation step of the synthesized polyurethane, those having a boiling point of 150 ° C. or less are preferred. When synthesizing the water-absorbing polyurethane gel fine particles of the present invention, the temperature may be low if a known catalyst is used, but a reaction temperature of 40 ° C. or higher is preferred from the viewpoint of work.

The polyurea colloid particles in the polyurea colloid solution used as an emulsifier at the time of synthesizing the water-absorbing polyurethane gel fine particles are composed of a part solvated with a solvent and a non-solvated part, The particle size of the sum portion is preferably 0.01 μm to 1.0 μm
The polyurea colloid solution is obtained by, for example, reacting a fat-modified polyol, a polyisocyanate (or a terminal NCO prepolymer comprising these compounds) and a polyamine compound in a non-aqueous solvent. In this reaction, as the reaction proceeds, insoluble urea domains are formed in the solvent due to hydrogen bonds between the urea bonds, and at the same time, the oil-modified polyol chains are solvated in the solvent, so that the insoluble urea domain is formed. Enlargement of polyurea colloid particles due to aggregation of domains is prevented, and a stable polyurea colloid solution can be easily obtained.

Further, the oil-modified polyol used has low crystallinity in a non-aqueous solvent, and the polymer chains mainly composed of the oil-modified polyol in the solvent are free to some extent even in the process of polymerizing which occurs as the reaction proceeds. To be able to move
Separation of the non-soluble crystalline part and the soluble non-crystalline part was easily performed, forming a urea domain centered on the particle with the non-soluble crystalline part due to hydrogen bonding between urea bonds, and solvated around it. The polymer chains are regularly oriented outward. This is a fundamentally different action from a surfactant in a known method for producing colloidal particles obtained by polymerizing under a micelle.

The method for producing the above polyurea colloid solution will be described more specifically. First, a fat-modified polyol and a polyisocyanate compound are reacted in a non-aqueous solvent or without a solvent to synthesize a prepolymer having an NCO group. Next, this prepolymer is charged into a jacket type synthesis kettle equipped with a stirrer, and the concentration is adjusted by adding a non-aqueous solvent so that the concentration becomes 5 to 70% by weight. While stirring this solution, a solution of a polyamine compound adjusted to a concentration of 2 to 20% by weight in advance is gradually added to carry out a reaction, and a polyurea colloid solution is produced in the polyureaization reaction.

The method of adding the polyamine may be a method of adding the prepolymer or a solution thereof to a polyamine solution, in addition to the above method. The temperature for synthesizing the polymer is not particularly limited, but a preferred temperature is 30 ° C to 120 ° C. The reaction concentration, temperature, form of the stirrer, stirring power, addition rate of the polyamine solution and the prepolymer or its solution for polymer synthesis are not particularly limited, but the reaction between the polyamine compound and the isocyanate group of the prepolymer is fast. It is preferable to control the reaction so that no rapid reaction is performed.

The fat-modified polyol used for producing the polyurea colloid solution is a polyol having a functional group of 2 or less, and has a preferable molecular weight of 1,000 ± 300, but is not limited thereto. Specific examples of fats and oils modified polyols include, for example, a method of alcoholicizing various fats and oils with lower alcohols and glycols, a method of partially saponifying fats and oils, a method of esterifying a hydroxyl group-containing fatty acid with glycol, and the like. Those containing two or less hydroxyl groups, or P by JHSAUNDERS, KCFRISCH
OLYURETHANES, CHEMISTRY AND TECHNOLOGY PART 1, Chemi
Fat-modified polyols described in stry (p48-53) (issued in 1962) and the like. Examples of the hydroxyl group-containing fatty acid include ricinoleic acid, 12-hydroxystearic acid, castor oil fatty acid, and hydrogenated castor oil fatty acid.

The reaction between the oil-modified polyol and the polyisocyanate compound is performed under the condition of 1 <NCO / OH ≦ 2, and the molecular weight of the prepolymer chain to be solvated is controlled. The molecular weight of the prepolymer synthesized in this way is
Although not particularly limited, a preferable range is about 500 to 15,
000. The polyisocyanate compound used in the present invention includes all known polyisocyanate compounds. Particularly preferred are aliphatic or alicyclic diisocyanate compounds such as hexamethylene diisocyanate, hydrogenated TDI, hydrogenated MDI, and isophorone diisocyanate.

As the non-aqueous solvent used for the production of the polyurea colloid solution, any non-aqueous solvent which does not have active hydrogen and which dissolves the oil / fat-modified polyol, diisocyanate compound and polyamine compound used as the raw materials can be used. I can do it. Particularly preferred are hexane,
It is a hydrocarbon system such as heptane, octane, decane, cyclohexane, toluene and xylene. In the present invention, "dissolution" includes both dissolution at normal temperature and high temperature.

As the polyamine compound used for producing the polyurea colloid solution, for example, ethylenediamine,
Diaminopropane, diaminobutane, hexamethylenediamine, trimethylhexamethylenediamine, N-aminoethylpiperazine, bis-aminopropylpiperazine, polyoxypropylenediamine, 4,4-diaminodicyclohexylmethane, isophoronediamine, thiourea, methyliminobispropyl A single or a mixture of diamines such as amines can be preferably used.

The types, amounts and ratios of the oil- and fat-modified polyols, diisocyanate compounds, polyamine compounds and the obtained prepolymers used in the production of the polyurea colloid solution are determined by the size and stability of the polyurea colloid particles in the solvent used. Etc. are determined for the purpose of controlling.
That is, the polyurea colloid particles in the polyurea colloid solution of the present invention are formed by urea domains of crystal parts that are not solvated in the solvent and polymer chains extending from the urea domains and solvated in the solvent.

The size of the urea domain and the size and morphology of the solvated polymer chains of the polyurea colloid particles in the polyurea colloid solution determine the properties of the polyurea colloid solution. As described above, the polyurea colloid solution formed by the urea domain and the solvated polymer chain is a stable polyurea colloid solution, and the particle size of the urea domain of the polyurea colloid particles in the solution is usually 0.01 to The molecular weight of one of the solvated polymer chains is about 500 to 15,000, and the weight ratio of both is 0.5 to urea domain (urea bond or polyamine compound) / polymer chain. A range of 30 is preferred. When the ratio of the urea bond is less than the above range,
Non-solvable urea domains in the obtained polyurea colloid particles are hardly formed, and the polyurea colloid particles are easily dissolved in a non-aqueous solvent, and a good polyurea colloid solution is not produced. On the other hand, when the ratio of the urea bond exceeds the above range, the size of the nonsolvable urea domain becomes large, the stability of the obtained polyurea colloid solution is reduced, and the aggregation of the polyurea colloid particles is likely to occur.

The polyurea colloid solution as described above looks like a blue milky light to a yellowish milky light due to light scattering. The dried and solidified polyurea colloid solution can be easily redispersed in a relatively low-solvent hydrocarbon solvent to give a polyurea colloid solution of any concentration,
It is almost soluble in polar solvents such as dimethylformamide, formamide, dimethylsulfoxide, methylethylketone, and butylacetate, and urea bonds in the polymer are precipitated by adding an appropriate amount of a solvent having a low solubility as described above. Crystallization forms an unsolvated urea domain to form a polyurea colloid solution.

Since the polyurea colloid particles in the polyurea colloid solution are heterogeneous particles formed from the solvated polymer chains and the urea domain of the unsolvated crystal part, their properties are solvated. Has the performance of both non-urea domains and solvated polymer chains. As an example, a polyurea colloid solution synthesized by reacting a prepolymer having an NCO group with a polyamine compound at a molar ratio of NCO / NH ₂ = 1.0 is formed on a glass plate as a solution having a solid content of 10% by weight. ,
When the dried film was applied so as to have a thickness of 10 μm and dried to form a film, the dried film was excellent in transparency and tack-free, and surprisingly, the melting temperature was 200 ° C. or higher. .

The form of the polyurea colloid particles used in the present invention in a solvent is assumed to be as shown in FIG. Regarding the control of the particle size of the polyurea colloid particles, it is possible to control the size of the entire particle including the solvated polymer portion and the urea domain, and the respective sizes of the solvated polymer portion and the urea domain. is there. The particle size of the polyurea colloid particles described above represents a urea domain portion.

In order to produce a stable and controlled polyurea colloid solution, it is desirable that the solvated polymer portion and the urea domain portion are clearly phase-separated as shown in FIG. It is necessary to manufacture the polymer chain so that the polymer chain to be added and the urea domain of the crystal part do not coexist. For this purpose, synthesis conditions are required in which the solvated polymer portion and the urea domain portion are easily separated in the synthesis process.

The synthesis of the polyurea colloid solution is performed using NCO
The lower the concentration of both the solution of the prepolymer having groups and the solution of the polyamine compound, the slower the addition rate of adding the other solution to one solution, the better the results are obtained, and stirring with a propeller mixer is sufficient. . When the concentration of the raw material solution is high or when the solution is added at a high rate, the synthesis is preferably performed while mixing with a high shear force by using a homogenizer or the like. The reaction temperature is determined by the type of the solvent used and the solubility of the urea domain in the solvent.
Although it is 0 ° C., it is not particularly limited to this temperature range. The urea domain may be formed in a synthesis process, or may be formed in a cooling process of a product synthesized at a high temperature.

The important factors of the polyurea colloid particles in the polyurea colloid solution are the type and concentration of the surface groups, and the dispersibility in an inert solvent and the dispersed particle size. That is, the action of the polyurea colloid solution as an emulsifier is a W / O or O / O type emulsifier, and the polyisocyanate compound and the compound having at least a polyethylene oxide group and active hydrogen have high hydrophilicity and hydrophobicity and are inactive. It works in correlation with the solvent. As a result of considering these conditions, the particle size of the water-absorbent polyurethane gel fine particles is controlled by adjusting the amount of the polyurea colloid solution added to the polyisocyanate compound and the compound having at least polyethylene oxide group and active hydrogen. In the above range, the larger the amount of addition, the smaller the particle size, and the smaller the amount, the larger the particle size.

The water-absorbent polyurethane gel fine particles of the present invention can be obtained by separating the inert solvent from the polyurethane dispersion obtained from the above raw materials under normal pressure or reduced pressure. Any known apparatus such as a spray drier, a vacuum drier with a filtration device, a vacuum drier with a stirrer, and a shelf type drier can be used as a device used for particle formation, and preferable drying temperatures are a vapor pressure of an inert solvent, water absorption. Although it is affected by the softening temperature, particle size and the like of the polyurethane gel fine particles, it is preferably 40 ° C to 80 ° C under reduced pressure.

The water-absorbing polyurethane gel fine particles thus produced have a true spherical shape with a particle size of 0.5 μm to 100 μm. The control of the particle size depends on the emulsification type (propeller type, anchor type, homogenizer, spiral band type, etc.) of the synthesis pot and the magnitude of the stirring power when the composition of the polyurethane is the same. It is affected by the concentration of the polyisocyanate compound and the compound having at least the polyethylene oxide group and active hydrogen, the type and the amount of the polyurea colloid solution. The mechanical stirring and shearing force for emulsifying the polyisocyanate compound and the compound having at least polyethylene oxide groups and active hydrogen are determined in the initial stage of emulsification, and the stronger this is, the smaller the particle size of the dispersion becomes. Subsequent stirring and shearing forces have no significant effect. On the contrary, if the force is too strong, it promotes the aggregation of the dispersions, which is not preferable.

In the present invention, in producing the above-mentioned water-absorbing polyurethane gel fine particles, at least a part or all of the raw materials include a coloring agent such as a dye or a pigment, a plasticizer, a stabilizer, an antioxidant, an ultraviolet absorber, It is also possible to mix various additives such as an antistatic agent, an abrasive, an extender and the like to synthesize polyurethane and obtain water-absorbent polyurethane gel fine particles suitable for various uses.

These fine particles are almost perfectly spherical fine particles as shown in the electron micrograph (5,000 times magnification) of FIG. 2, and as shown in the imaginary diagram of FIG. Polyurea colloid particles precipitated from the polyurea colloid solution are adhered or coated on the surface of the fine particles, and since the polyurea colloid particles are excellent in non-adhesiveness and heat resistance, the fine particles are simply removed from the dispersion solvent. Fine particles having extremely high fluidity have various advantages such as no need for complicated and costly pulverizing steps and classification operations as in the prior art.

[0038]

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are based on weight unless otherwise specified.

(Preparation of Polyurea Colloid Solution) Example 1 Bifunctional oil- and fat-modified polyol having a hydroxyl value of 119.5 (Italy)
URIC Y-202 manufactured by Fuji Oil Co., Ltd.) 100 parts and n-
100 parts of octane was charged into a synthesis kettle equipped with a stirrer to dissolve the polyol. The temperature was controlled to 50 ° C. while stirring, and 47.3 parts of isophorone diisocyanate prepared in advance so that NCO / OH = 2 was gradually added over 1 hour. The reaction was continued for 3 hours under these conditions, and the reaction was continued for 80 hours. The reaction was performed at 3 ° C. for 3 hours to complete the synthesis. Next, the concentration was adjusted to 50% with n-octane to obtain a prepolymer solution (PP-1) containing 2.9% of NCO groups. The molecular weight of this product is 1,3
83.

40 parts of the above PP-1 were charged and dissolved in 60 parts of n-octane in a synthesis kettle equipped with a stirrer. While stirring and controlling the temperature to 70 ° C., the previously prepared n-octane of isophorone diamine was prepared. 23.4 parts of a 10% solution was gradually added over 5 hours to complete the reaction, and (polyamine (urea bond) / prepolymer chain) × 100 = 1
1.7% polyurea colloid solution (solid content 18.1
%) (C-1). This solution was a blue opalescent stable solution.

Example 2 A bifunctional oil / fat-modified polyol having a hydroxyl value of 119.5 (Italy)
URIC Y-202 manufactured by Fuji Oil Co., Ltd.) 100 parts and n-
100 parts of octane was charged into a synthesis kettle equipped with a stirrer to dissolve the polyol. The temperature was controlled to 50 ° C. while stirring, and 26.6 parts of isophorone diisocyanate prepared in advance so that NCO / OH was 1.1 was gradually added over 1 hour, and the reaction was continued under these conditions for 3 hours. 80 ° C 4
The reaction was completed for a period of time to complete the synthesis. Next, the concentration was adjusted to 50% with n-octane to obtain a prepolymer solution (PP-2) containing 1.64% of NCO groups. The molecular weight of this product is 2,543.

20 parts of the above PP-2 and n-octane 8
0 parts were charged into a synthesis kettle equipped with a stirrer to dissolve the above prepolymer. While stirring and controlling the temperature to 70 ° C., 17.0 parts of a 1% solution of n-octane of isophoronediamine prepared in advance was gradually added over 8 hours to complete the reaction, thereby completing the reaction (polyamine / prepolymer chain). ) × 100 = 1.7
% Polyurea colloid solution (solid content: 8.7%) (C-
2) was obtained. This solution was a blue opalescent stable solution.

Example 3 Monofunctional oil / fat-modified polyol having a hydroxyl value of 157.8 (Italy)
100 parts of URIC H-31 manufactured by Fuji Oil Co., Ltd. were charged into a synthesis kettle equipped with a stirrer, and the temperature was controlled at 60 ° C. while stirring, and a pre-prepared bird was prepared so that NCO / OH = 2.0. 49.0 parts of range isocyanate was gradually added over 1 hour, and the reaction was carried out for 5 hours under these conditions to complete the synthesis. Next, the concentration was adjusted to 60% with n-heptane, and NCO was added.
Solution containing 4.71% of a group (PP-3)
I got The molecular weight of this product is 528.

100 parts of the above PP-3 was charged into a synthesis kettle equipped with a stirrer, the temperature was controlled at 50 ° C. while stirring, and 88.5 parts of a 10% solution of n-heptane of trimethylhexamethylenediamine prepared in advance was prepared. Over 5 hours to complete the reaction, (polyamine / prepolymer chain)
× 100 = 14.75% polyurea colloid solution (solid content 36.5%) (C-3) was obtained. This solution was a yellowish opalescent stable solution.

Example 4 A bifunctional oil- and fat-modified polyol having a hydroxyl value of 165.5 (Italy
URIC Y-403 manufactured by Fuji Oil Co., Ltd.) 100 parts and n-
100 parts of decane was charged into a synthesis kettle equipped with a stirrer to dissolve the polyol. The temperature was controlled at 50 ° C. while stirring, and 49.6 parts of hexamethylene diisocyanate prepared in advance were gradually added over 1 hour so that NCO / OH = 2.0, and the reaction was carried out under these conditions for 3 hours. Continue, 8 more
The reaction was carried out at 0 ° C. for 3 hours to complete the synthesis. Next, the concentration was adjusted to 50% with n-decane to obtain a prepolymer solution (PP-4) containing 4.05% of NCO groups. The molecular weight of this product is 1,012.

Forty parts of the above PP-4 and n-decane 60
And the above prepolymer was dissolved in a synthesis kettle equipped with a stirrer. The temperature was controlled at 70 ° C. while stirring, and a 5% solution of n-decane of hexamethylenediamine prepared in advance 4
9.8 parts were gradually added over 8 hours to complete the reaction,
(Polyamine / prepolymer chain) × 100 = 12.45
% Polyurea colloid solution (solid content 15%) (C-
4) was obtained. This solution was a clear blue opalescent stable solution.

(Production of Water Absorbent Polyurethane Gel Fine Particles) Example 5 20 parts of polyethylene glycol having an average molecular weight of 1,000 was dissolved at 60 ° C., and hexamethylene diisocyanate represented by the following structural formula was dissolved therein. Isocyanurate polyisocyanate (Duranate T manufactured by Asahi Kasei Corporation)
(PA-100) 8.12 parts were added and mixed uniformly. 3 parts of a polyurea colloid solution (C-1) previously prepared in a 1-liter stainless steel container and n-heptane 50
Of the mixture and emulsified with a homogenizer for 15 minutes. This emulsion has an average dispersoid particle size of 5
It was a stable emulsion having a particle size of μm without separation of particles.

Next, this was charged into a reactor with an anchor-type stirrer, and the temperature was raised to 80 ° C. while rotating at 500 rpm, and the reaction was completed for 6 hours to obtain a dispersion of fine particles of water-absorbent polyurethane gel. This dispersion was vacuum-dried at 100 Toor to separate n-heptane, thereby obtaining water-absorbent polyurethane gel fine particles (1) of the present invention. This was a true spherical white powder having an average particle diameter of 5 μm.

Example 6 100 parts of polyethylene glycol having an average molecular weight of 2,000 was charged into a reactor equipped with an anchor-type stirrer, heated to 70 ° C., stirred and dissolved in diphenylmethane diisocyanate (M
DI) 25 parts were gradually added, and the reaction was carried out for 5 hours.
A prepolymer of O / OH = 2 was obtained. To this, 4.5 parts of trimethylolpropane was added and mixed.

25 parts of this product were gradually added to a mixture of 12 parts of the polyurea colloid solution (C-2) of Example 2 and 50 parts of n-heptane, which had been prepared in a 1-liter stainless steel container in advance. The mixture was emulsified with a homogenizer for 25 minutes.
This emulsion was a stable emulsion having an average dispersoid particle size of 8 μm and no separation of particles. Next, this was charged into a reaction vessel equipped with an anchor-type stirrer, the temperature was increased to 100 ° C. while rotating at 500 rpm, and the reaction was completed for 5 hours to obtain a dispersion of water-absorbent polyurethane gel fine particles. In the same manner as in Example 5, water-absorbent polyurethane gel fine particles (2) of the present invention were obtained from this dispersion. This was a true spherical white powder having an average particle diameter of 8 μm.

Example 7 In 20 parts of an ethylene oxide-tetrahydrofuran random copolymer having an average molecular weight of 1,800 (molar ratio: 70/30)
Polymeric isocyanate represented by the following structural formula (NCO = 31.5% : manufactured by Kasei Upjohn Co., Ltd.)
API 135) 2.36 parts were added and NCO / OH =
Adjusted to 0.8 and mixed at low speed. This product was added to 3 parts of the polyurea colloid solution (C-3) of Example 3 and 97 parts of isooctane, which were previously prepared in a 1-liter stainless container, and dispersed by ultrasonic waves. This dispersion was a stable emulsion having an average dispersed particle size of the dispersoid of 3 μm and no separation of particles.

Next, this was charged into a reaction vessel equipped with an anchor-type stirrer, the temperature was raised to 80 ° C. while rotating at 500 rpm, and the reaction was completed for 2 hours to obtain a dispersion of water-absorbent polyurethane gel fine particles. This dispersion was treated in the same manner as in Example 5 to obtain the water-absorbent polyurethane gel fine particles (3) of the present invention.
I got This was a true spherical white powder having an average particle diameter of 3 μm.

Example 8 A method similar to that of Example 5 was repeated, except that the polyurea colloid solution (C-1) of Example 5 was replaced with 4 parts of the polyurea colloid solution (C-4) of Example 4. . The obtained water-absorbent polyurethane gel particles (4) have an average particle diameter of 4
It was a true spherical white powder of μm.

The water absorption capacity and solvent resistance of the polyurethane gel particles obtained above were as shown in Table 1 below.

[Table 1]

* 1: Changes in the size (diameter) of the particles before and after water absorption at 25 ° C. (when the value before water absorption was set to 1) were observed with a microscope. * 2: The state of the dispersion was visually observed when 20 parts of the fine particles were added to 80 parts of the solvent and lightly stirred by hand. ○: dispersion
Δ; paste ×; gel Solvent 1: ethyl acetate Solvent 2: methyl ethyl ketone Solvent 3: dimethylformamide Solvent 4: toluene Solvent 5: mineral spirit Solvent 6: isopropyl alcohol

[0056]

The present invention has the following effects. 1. It is possible to produce water-absorbent polyurethane gel fine particles having a controlled particle size. 2. The obtained water-absorbent polyurethane gel fine particles are truly spherical, and the surface of the water-absorbent polyurethane gel fine particles is uniformly adhered or coated with polyurea colloid particles precipitated from the polyurea colloid solution used as an emulsifier. Fine particles have extremely excellent fluidity and are easy to handle, and have various advantages such as extremely easy transport, measurement, and re-dispersion in a solvent or resin. 3. From the above effects, the water-absorbent polyurethane gel fine particles of the present invention are modified to give paints, coatings, resins, rubbers, elastomers, etc. excellent performances such as water absorbency, water swellability, water wettability, and antistatic properties. It is useful as an agent.

[Brief description of the drawings]

FIG. 1 is an imaginary view of a cross section of polyurea colloid particles in a polyurea colloid solution used in the present invention.

FIG. 2 is a view showing one example of a state of water-absorbent polyurethane gel fine particles of the present invention.

FIG. 3 is an imaginary view of a cross section of the water-absorbent polyurethane gel fine particles of the present invention.

[Explanation of Signs] 1: Solvated polymer chain 2: Urea domain of unsolvated part 3: Water-absorbing polyurethane gel fine particle 4: Polyurea colloid particle

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takao Endo 1-7-6, Bakurocho, Nihonbashi, Chuo-ku, Tokyo Inside Dainichi Seika Kogyo Co., Ltd. (56) References JP-A-5-239341 (JP, A) JP-A-5-239340 (JP, A) JP-A-5-70539 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18/08-18/81

Claims (6)

(57) [Claims] (1) at least one of the compounds has three
At least a polyisocyanate compound and
A compound having a polyethylene oxide group and active hydrogen
A three-dimensionally crosslinked water-absorbing polyurethane gel particles made of, surface polyurea colloid nonaqueous of the fine particles
Water-absorbent polyurethane gel fine particles coated with polyurea colloid particles precipitated from a medium solution . 2. The polyurea colloid particles in the polyurea colloid non-aqueous solvent solution are composed of a part solvated with a solvent and a non-solvated part, and a non-solvated part. The water-absorbent polyurethane gel fine particles according to claim 1, wherein the particles have a particle size of 0.01 µm to 1.0 µm. 3. The polyurea colloid particles in the polyurea colloid non-aqueous solvent solution are polyurea colloid particles obtained by reacting an oil- and fat-modified polyol, a polyisocyanate and a polyamine compound, wherein the unsolvated part is a polyurea colloid particle. 2. The water-absorbent polyurethane gel fine particles according to claim 1, wherein the particles comprise hydrogen bonds of urea bonds. 4. The water-absorbent polyurethane gel fine particles according to claim 1, wherein the particle size is in the range of 0.5 to 100 μm. 5. The at least one compound trifunctional or more, per a compound having at least polyethylene oxide group and an active hydrogen and polyisocyanate compound to be a three-dimensional reaction by emulsion polymerization in an inert solvent,
A method for producing water-absorbent polyurethane gel fine particles, comprising using a polyurea colloid non-aqueous solvent solution as an emulsifier. 6. The method according to claim 5 , wherein the emulsion polymer is taken out of the inert solvent as a powder.