JP2001342339A - Water curable urethane resin composition, coating, coating material, sealing medium, adhesive, and method of producing cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water curable urethane resin composition which has a low viscosity in production, transfer and blending, but and does not sag when applied to an unhorizonal plane, and to provide a coating, a coating material, a sealing medium, and an adhesive made of the composition, and a method of producing their cured products. SOLUTION: The water curable urethane resin composition comprises an isocyanate group terminated prepolymer and a hydrophilic particulate silica added thereto. A carbon dioxide gas absorber is preferably added thereto, and the carbon dioxide gas absorber is preferably magnesium dioxide having a specific surface area by the BET method of >=30 m2/g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a water-reaction-curable urethane resin composition, a paint, a coating material, a sealing material, an adhesive, and a cured product. The present invention relates to a water-reaction-curable urethane resin composition which cures as a uniform elastomer without dripping, a paint, a coating material, a sealing material, an adhesive using the composition, and a method for producing a cured product thereof.

[0002]

2. Description of the Related Art Generally, urethane resin compositions used as paints, coating materials, sealing materials, adhesives and the like include a two-component reaction type and a one-component moisture curing type. In such a urethane resin composition, a filler such as a surface-treated calcium carbonate is usually incorporated into the composition in order to prevent the sagging even when the urethane resin composition is applied to an uneven surface. .

[0003]

Incidentally, among the urethane resin compositions described above, the two-component reaction type does not cure if the compounding ratio is slightly deviated from an appropriate compounding,
Even if cured, there is an inconvenience that the cured product does not exhibit predetermined physical properties.

On the other hand, the one-component moisture-curing type is cured by reacting with moisture in the air, and naturally the reaction proceeds from the surface, so that when the thickness is increased, the internal curing is delayed. . Also, the reaction between isocyanate groups in the urethane resin composition and moisture (water) generates carbon dioxide gas. This carbon dioxide gas becomes bubbles and causes blistering between the coating film and the coated surface, It may remain inside and lower the function of the coating film. In order to prevent the inconvenience caused by the bubbles caused by the generation of carbon dioxide gas, there were extremely large restrictions.

Furthermore, in order to prevent the one-part moisture-curing type from dripping even when applied to an uneven surface, a filler such as surface-treated calcium carbonate is blended as described above. Although the viscosity is increased, when a one-part moisture-curing type filler is blended to increase the viscosity, the paint, coating material, sealing material or adhesive made of this urethane resin composition is manufactured, transported, Furthermore, a great deal of restrictions are imposed on operations such as mixing and the like, resulting in poor practicability and handleability.

[0006] The present invention has been made in view of the above-mentioned circumstances, and is intended to allow a deviation of the composition, prevent the internal curing of a thick material from being delayed, and prevent a carbon dioxide gas generated during the reaction from forming bubbles. Along with providing the curable urethane resin composition, manufacturing, transporting, low viscosity until mixing,
To provide a paint, a coating material, a sealing material, and an adhesive that will not sag when applied to a non-horizontal surface, and to provide a method for producing a cured product of the water-reaction-curable urethane resin composition. is there.

[0007]

Means for Solving the Problems The present inventors have obtained a cured product which does not foam when an isocyanate group is reacted with an excessive amount of water in the presence of a carbon dioxide gas absorbent. It has been found that, when the silica is mixed with water, the viscosity increases immediately after mixing with water and thixotropic properties are developed, and the present invention has been achieved.

That is, in the water-reaction-curable urethane resin composition according to the first aspect of the present invention, hydrophilic fine-particle silica is added to the water-reaction-curable urethane resin composition containing an isocyanate group-terminated prepolymer. This is the means for solving the above problem. Further, in the paint according to claim 7, the coating material according to claim 8, the sealing material according to claim 9, and the adhesive according to claim 10, the water-reaction-curable urethane resin composition is used. Is a means for solving the above problem. Furthermore, in the method for producing a cured product according to claim 11 of the present invention, the isocyanate group-terminated prepolymer in the water-reaction-curable urethane resin composition is added in an amount of 5 to 1 equivalent of isocyanate group in the isocyanate group-terminated prepolymer. Means for solving the above-mentioned problem is that a reaction is carried out using a large excess of water as an equivalent or more as a curing agent to cure the water reaction-curable urethane resin composition.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The water-reaction-curable urethane resin composition of the present invention is obtained by adding hydrophilic fine-particle silica to a water-reaction-curable urethane resin composition containing an isocyanate group-terminated prepolymer.

As the isocyanate group-terminated prepolymer, a water-reaction-curable urethane resin composition which is easy to handle and has excellent coatability, safety, curability, etc. can be easily obtained, and the cured product has excellent physical properties. Urethane prepolymer is preferably used for such reasons. Urethane prepolymer is a polyisocyanate compound having two or more isocyanate groups in one molecule and a compound having two or more active hydrogens in one molecule that reacts with the isocyanate group. It is a compound (prepolymer) having a group at least at the molecular end. In addition, as such a urethane prepolymer, those having a molecular weight of about 500 or more, particularly 700 or more are suitably used.

In the present invention, a prepolymer prepared by reacting a polyisocyanate compound with a polyol compound having two or more alcoholic hydroxyl groups in one molecule is used as such a urethane prepolymer. That is, a preferable urethane prepolymer in the present invention is obtained by reacting a polyether polyol or a polyester polyol with an excessive amount of a polyisocyanate compound, and has at least two isocyanate groups at a molecular terminal. Examples of the polyether polyol include a polyether glycol such as polypropylene glycol, and examples of the polyester polyol include a polyester glycol such as polyethylene adipate glycol.

The urethane prepolymer preferably contains about 1 to 15% by weight, especially 1 to 7% by weight of isocyanate groups in the total amount. Further, the content of the urethane prepolymer is 40% by weight or more, particularly preferably 50% by weight, based on the total amount of the water reaction-curable urethane resin composition of the present invention.
When the content is at least% by weight, a cured product having excellent physical properties can be easily obtained, which is preferable. As the polyol compound, various polyols generally used for producing a urethane compound are used, and for example, a polyether polyol, a polyester polyol, and other polyols can be used.

Specific examples of the polyether polyol include homopolymers or copolymers of propylene glycol, ethylene glycol and tetramethylene glycol; one or two kinds of low-molecular-weight active hydrogen compounds having two or more active hydrogens. A random copolymer or block copolymer obtained by ring-opening polymerization of propylene oxide and ethylene oxide in the presence of the above; polyoxytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, and the like.

The low molecular weight active hydrogen compound includes:
Diols such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol; triols such as glycerin, trimethylolpropane, 1,2,6-hexanetriol; ammonia, methylamine, ethylamine, propyl Amines such as amine and butylamine are used.

Specific examples of the polyester polyol include a polymer obtained by dehydrating and condensing a polybasic acid and a polyhydric alcohol; a condensate of a hydroxycarboxylic acid and a polyhydric alcohol; and a ring-opening polymer of lactone. No.

The polybasic acids include, for example, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, succinic acid, dimerized linoleic acid, maleic acid,
And di-lower alkyl esters thereof.
One or more of them are used.

Examples of the polyhydric alcohol include diols such as bisphenol A, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol and neopentyl glycol. Glycerin, 1,1,1-trimethylolpropane, 1,
Triols such as 2,6-hexanetriol, triethylene glycol and tripropylene glycol are used.

As other polyols, specifically,
Acrylic polyols, hydrogenated polybutadiene polyols, castor oil derivatives, tall oil derivatives, polymer polyols, polycarbonate polyols, etc.,
Examples include low molecular polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, and hexanediol, and these can also be used.

The polyol compound has a number average molecular weight of 100 to 10,000, preferably 300.
5,000 to 5,000, depending on the desired properties for each application, alone or as a mixture of two or more. When using a polymer polyol having a number average molecular weight of 5,000 or more,
When a relatively hydrophilic compound containing an ethylene oxide skeleton is used as the polyol compound, the urethane resin composition using the compound is easily mixed with water.

As the polyisocyanate compound,
Aliphatic polyisocyanates such as hexamethylene diisocyanate and lysine methyl ester diisocyanate;
Alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, norbornane diisocyanate (NBDI); tolylene diisocyanate (TD
I), diphenylmethane diisocyanate (MDI),
Aromatic polyisocyanates such as p-phenylene diisocyanate; carbodiimide-modified or isocyanurate-modified ones of the above polyisocyanates; these may be used alone or in combination of two or more. Preferably, TDI, MDI
And aromatic polyisocyanates.

The urethane prepolymer has one isocyanate group contained in the polyisocyanate compound per one mol of the hydroxyl group contained in the polyol compound.
Molar, ie, the chemical equivalent ratio (NCO /
(OH) exceeds 1 by heating and reacting a polyol compound and a polyisocyanate compound as necessary. Such a urethane prepolymer usually has isocyanate groups at both molecular terminals. Further, as the urethane prepolymer, a hydroxyl group (O
H) One mole of the isocyanate group (NCO) contained in the polyisocyanate compound is reacted with the polyol compound and the polyisocyanate compound at a ratio of 1.6 to 3.0 moles per mole of the polyisocyanate compound. It is more preferable in terms of the influence on the human body, the physical properties of the cured product, and the like. Further, it is preferable to use a liquid prepolymer having a fluidity at 23 ° C. as a urethane prepolymer, because a solvent-free paint, a coating material, a sealing agent, an adhesive and the like can be easily produced.

The hydrophilic fine silica added to the urethane prepolymer as the isocyanate group-terminated prepolymer of the present invention has a particle size of 6 nm or more.
Those having a range of 30 nm or less and a specific surface area of 100 m ² / g or more by a BET method are suitably used. 6n
If the diameter is less than m, the production cost is high due to the difficulty in production, and if it exceeds 30 nm, the effect of increasing the viscosity when water is added will not be sufficiently obtained as described later. On the other hand, if the specific surface area by the BET method is less than 100 m ² / g, it is difficult to obtain sufficient viscosity and thixotropic manifestation when mixed with water. Here, the BET method is a method of measuring the specific surface area of the powder by an adsorption method, and the specific surface area of the hydrophilic fine silica by the BET method can be obtained from the amount of nitrogen gas adsorbed per 1 g of the hydrophilic fine silica. it can.

[0023] Such hydrophilic finely divided silica is preferably at least 0.3 part by weight and 14.0 parts by weight based on the urethane prepolymer (isocyanate group-terminated prepolymer).
It is blended in a range of not more than part by weight. If the amount is less than 0.3 part by weight, the effect of addition is hardly obtained, while if it exceeds 14.0 parts by weight, the effect is hardly expected to increase.

The water-reaction-curable urethane resin composition of the present invention to which such hydrophilic fine-particle silica has been added, when water is added thereto, the hydrophilic fine-particle silica is immediately mixed with water. Thickening occurs, thereby expressing thixotropic. Therefore, even when applied on a place other than a horizontal plane, for example, on a vertical plane, dripping is sufficiently prevented.

Further, in the water-reaction-curable urethane resin composition of the present invention, various kinds of compounds can be blended in addition to the hydrophilic fine-particle silica, and a carbon dioxide gas absorbent is particularly preferably blended. The carbon dioxide gas absorbent particularly has a specific surface area by the BET method (hereinafter, referred to as a BET specific surface area) of 30.
Magnesium oxide of m ² / g or more (hereinafter sometimes referred to as active magnesium oxide) is preferably used. Magnesium oxide having such a specific surface area has an activity of preventing foaming or the like due to a reaction between water and an isocyanate group. The active magnesium oxide preferably has a BET specific surface area of 60 m ² / g or more, and particularly has a BET specific surface area of 60 to 150 m ^{2 in} terms of ease of handling, reactivity, workability, storage stability and the like. / G is desirable.

The active magnesium oxide preferably has a BET specific surface area of 30 m ² / g or more and an iodine adsorption amount of 30 iodine mg / g or more. In addition, this active magnesium oxide
It is preferable that 95% by weight or more of the particles have a particle size passing through a sieve having an opening of 149 μm, and more preferably 99% by weight or more.

The active magnesium oxide may be magnesite (MgCO ₃ ) or magnesium hydroxide [Mg (O
H) ₂ ] at 1200 ° C. or lower and finely pulverized. Gnesium oxide calcined at such a calcining temperature has high activity, and thus is suitably used as active magnesium oxide in the present invention. On the other hand, magnesium obtained by firing at a temperature exceeding 1200 ° C., particularly 1500 ° C., is inferior in activity to magnesium obtained by firing at a temperature of 1200 ° C. or lower and is not preferred.

It is not clear why the use of active magnesium oxide gives a cured product of a polyurethane resin which is difficult to foam with water (hereinafter, sometimes simply referred to as a cured product). It is considered to exhibit an activity of preventing foaming by gas absorption, moderate water absorption, moderate catalysis and the like. It is said that magnesium oxide takes in and absorbs carbon dioxide in its crystals by a reaction represented by the following formula.
In this case, as shown in the following formula, magnesium hydroxycarbonate is produced as a product. 4MgO + 3CO ₂ + 4H ₂ O → 3MgCO ₃ · Mg
(OH) ₂ · 3H ₂ O

The amount of active magnesium oxide is as follows:
It depends on the concentration of isocyanate groups contained in the urethane prepolymer, and is 0.1 to 1 mol of the isocyanate groups.
It is preferable to mix them in a proportion of 5 mol or more.
If the molar ratio between the active magnesium oxide and the isocyanate group (MgO / NCO) is less than 0.5, it is difficult to obtain a curable urethane resin composition which is hardly affected by water.

From the viewpoints of workability, finish of the surface of the cured product, physical properties of the cured product, and the like, the amount of the active magnesium oxide is about 0.1 to 1 mol of the isocyanate group contained in the urethane prepolymer. The proportion is preferably 5 to 3 mol, more preferably about 0.7 to 2 mol. If the molar ratio (MgO / NCO) between the active magnesium oxide and the isocyanate group exceeds 3, the viscosity of the resulting composition increases, and the coating properties are likely to deteriorate. The amount of the active magnesium oxide compounded by weight is about 0.1 part by weight based on 100 parts by weight of the isocyanate compound of the urethane prepolymer.
It is preferably from 5 to 15 parts by weight, especially from about 1 to 7 parts by weight.

The active magnesium oxide is kneaded in advance with a liquid component or a plasticizer described below, dispersed in the mixture, and then mixed with a urethane prepolymer or the like in the form of a paste. Is easily dispersed in a urethane prepolymer or the like, and the handleability is improved.

The liquid component is used for uniformly and efficiently dispersing the active magnesium oxide in the urethane prepolymer or the like, and is generally a liquid reaction component such as various plasticizers and polyol compounds which can be blended in the urethane resin. And various other liquid components are used, and those subjected to a dehydration treatment are preferably used.

Specific examples of the plasticizer include carboxylic acid esters such as phthalic acid ester, adipic acid ester, sebacic acid ester, azelaic acid ester and trimellitic acid ester, as well as phosphoric acid ester, normal paraffin, and chlorinated paraffin. , Alkylbenzene, and other various liquid components, which may be used alone or as a mixture of two or more. Among them, price, compatibility with urethane prepolymer, etc., plasticizing effect, viscosity reducing effect,
In view of the physical properties of the cured product, diisononyl adipate (D
INA), di-2-ethylhexyl phthalate (DOP)
It is preferable to use a carboxylic acid ester such as The use amount of these plasticizers is preferably about 5 to 40 parts by weight based on 100 parts by weight of the urethane prepolymer or the like.

In the present invention, not only active magnesium oxide but also various magnesium oxides having different particle diameters and different active values may be added as the carbon dioxide gas absorbent.

As described above, the water-reaction-curable urethane resin composition of the present invention is preferably prepared by adding hydrophilic finely divided silica to a urethane prepolymer, and further comprising active magnesium oxide, a plasticizer dispersing the active magnesium oxide, and a liquid component. It is blended, further, if necessary, other various additives, for example, a solvent,
Surfactants, pigments, dyes, fillers, curing accelerating catalysts, antioxidants and the like are added within a range that does not impair the physical properties. These additives are usually added before the curing agent is added, and form the water reaction-curable urethane resin composition of the present invention.

The solvent used in the urethane resin composition of the present invention is for diluting a urethane prepolymer or the like, and specifically, aromatic hydrocarbons such as toluene, xylene and styrene and chlorines thereof. Chloride aliphatic hydrocarbons such as carbon tetrachloride, 1,1,1, -trichloroethane and 1,2-dichloroethylene; esters such as ethyl acetate and butyl acetate; ethers such as ethyl ether and tetrahydrofuran Ketones such as acetone and methyl ethyl ketone; hydrocarbon mixtures such as mineral spirits; and other liquid organic compounds. However, from the viewpoint of the influence on the environment and the like, it is preferable not to mix as much as possible.

The surfactant is appropriately selected according to the properties of an antifoaming agent, a wetting and dispersing agent for a pigment or a filler, an emulsifier, a viscosity improver, etc., which are added together, alone or in combination of two or more. Used as a mixture. However, when magnesium oxide is uniformly dispersed in a urethane prepolymer or the like and cured by mixing water as a curing agent,
It is preferable to add a highly hydrophilic wetting and dispersing agent (for example, a phosphoric acid ester-based wetting and dispersing agent) because mixing workability with water, coating workability, storage stability and the like can be improved.

In order to color the cured product, various azo pigments, organic pigments such as copper phthalocyanine pigment, and the like,
Carbon black, titanium oxide, zinc oxide, zinc sulfide,
Various inorganic pigments such as chromium oxide and red iron oxide are used, and as the dye, anthraquinone-based, fatty acid salts of basic dyes, metal complex salts and the like are used.

The filler is added for the purpose of reducing polymerization shrinkage, increasing the amount of the polymerization, improving the hardness and the like.
Calcium carbonate, clay, talc, silica, diatomaceous earth,
And finely divided inorganic fillers such as those obtained by surface-treating these with fatty acids or fatty acid esters.

As a curing promoting catalyst for promoting the reaction between the isocyanate group contained in the urethane prepolymer and the like and the curing agent, N-alkylbenzylamine, N-alkylaliphatic polyamine, triethylenediamine,
Examples thereof include alkyl piperazine, N-alkyl morpholine, dimorpholino diethyl ether, and organometallic compounds such as tin octenoate and dibutyl tin dilaurate, and these may be used alone or as a mixture of two or more. The amount of the curing accelerator used is preferably about 0.05 to 5 parts by weight based on 100 parts by weight of the urethane prepolymer.

The antioxidant is used to protect the cured product from light, oxygen, heat and the like, and generally includes a light stabilizer and an antioxidant. Examples of the light stabilizer include benzotriazole, benzophenone, benzoate, cyanoacrylate, hindered amine, nickel and the like. Examples of the antioxidant include hindered phenol-based, amine-based, sulfur-based, and phosphorus-based agents.

The water-curable urethane resin composition of the present invention obtained by appropriately mixing such various additives as necessary and having no curability by itself can be stored for a long period of time. Become. Further, the composition is polymerized by adding water and cured as a uniform elastomer. Therefore, in the present invention, water that is easily available, has no effect on the environment and human body, and is extremely easy to handle and the like is used as the curing agent.

The type of water to be added is not particularly limited as long as it does not contain impurities that deteriorate the physical properties and performance of the cured product. However, water of relatively high purity such as pure water, distilled water, or tap water is used. It is preferable to use Here, the amount of water to be added is 5 equivalents (mol) or more with respect to 1 equivalent (mol) of the isocyanate group in the isocyanate group-terminated prepolymer (urethane prepolymer). When water is added in such an amount, the isocyanate group-terminated prepolymer (urethane prepolymer) is cured at 23 ° C. in about 5 to 200 minutes by reaction with water. Further, when the hydrophilic finely divided silica is mixed with water, the viscosity increases immediately, and thixotropic properties are developed.

When the viscosity of the urethane resin composition is adjusted to be about 5 to 200 poise at 23 ° C., it becomes easy to mix water, and the curable urethane resin obtained by adding water is used. The composition can be applied by hand kneading and mechanical coating, and has a sufficient pot life. Here, the curable urethane resin composition is coated,
When used as a coating, sealant, or adhesive, the preferred cure time is about 10-60 minutes.

The curable urethane resin composition obtained by mixing water cures at room temperature in a short time as described above. Further, this curable urethane resin composition,
It has excellent adhesion to the adherend, and naturally does not cause bubbles, swelling, etc., even by air, moisture supplied from the paint, the adherend, or the like. In addition, since the hydrophilic fine-grained silica exhibits thixotropic properties by being mixed with water, even when applied to a non-horizontal surface, it is prevented from dripping, and therefore, the workability is extremely low. Are better. In addition, the curable urethane resin composition gives a thick cured product, and can further make the cured product translucent, so that coloring becomes easy.

As described above, the water-reaction-curable urethane resin composition of the present invention is particularly suitable as a paint, a sealing material, a coating material and an adhesive for hygroscopic materials such as wood, stone and concrete. By using, wood, stone, concrete, etc., or these and other things (for example, wood and concrete,
Concrete and a metal plate).
In this case, even if the wood, concrete, or the like contains some water, no bubbles are generated in the adhesive layer, and even if it is generated, the amount is small. Therefore, an adhesive product using the curable urethane resin composition of the present invention has excellent adhesive strength.

The urethane resin composition is also used as a sealing material for filling gaps formed in the structure and preventing intrusion of rainwater. In this case, since the sagging is prevented, the urethane resin composition is used in a horizontal direction. This is particularly useful as a material for filling joints such as roofs and walls of buildings that are not.

The urethane resin composition is also useful as a paint for coating stones, wood, concrete, asphalt and the like which are easily affected by rainwater. In particular, it is suitable as a paint for construction made of wood or concrete (particularly waterproof paint for walls and roofs). As a structure,
Examples include buildings, bridges, roads, athletic stadiums, pools, and the like.
In addition, when the water-reaction-curable urethane resin composition of the present invention is used as a paint or a sealing material for a concrete construction, a coating material, or an adhesive, in order to prevent a cured product from being deteriorated by alkali oozing out of concrete, As the urethane prepolymer, those using a polyether polyol are preferable.

[0049]

Next, the present invention will be described more specifically with reference to examples. In the following examples and comparative examples,
Parts and% mean parts by weight and% by weight, respectively. (Example) Production of urethane prepolymer solution Modified polypropylene glycol having a number average molecular weight of 3000 [MN-3050 (product number) manufactured by Mitsui Chemicals, polyether polyol having three hydroxyl groups in one molecule],
A mixture was prepared by mixing tolylene diisocyanate (TDI) as a polyisocyanate compound so that the molar equivalent ratio (NCO / OH) became 2.0.
With respect to 0 parts, 14 parts of di-2-ethylhexyl phthalate (DOP) as a plasticizer and 0.1 part of an antifoaming agent were added. The liquid mixture obtained by this addition was heated with stirring under low humidity, and reacted at 90 ° C. for 3 hours to obtain a urethane prepolymer liquid having fluidity at 23 ° C. The obtained urethane prepolymer solution contained 87.6% of a urethane prepolymer obtained by adding TDI to modified polypropylene glycol, and the urethane prepolymer contained 3.58% of isocyanate groups.

Production of urethane resin composition The urethane prepolymer solution has an average particle size of about 12 n.
m, hydrophilic fine silica having a BET specific surface area of about 200 m ² / g [Aerosil 200 (product number) manufactured by Nippon Aerosil Co., Ltd.]
Was added to 100 parts of the mixture of the polyether polyol and the polyisocyanate compound used as the material for producing the urethane prepolymer liquid, to obtain a urethane resin composition as an example in the present invention.

Comparative Example 1 The urethane polymer liquid before the addition of the hydrophilic finely divided silica in the above example was used as Comparative Example 1 as it was.

(Comparative Examples 2 and 3) In the above Examples, the urethane polymer liquid before the addition of the hydrophilic fine silica was added to
14 parts of surface-treated calcium carbonate [Shiraishi Calcium CCR.B (product number) manufactured by Shiraishi Calcium Co., Ltd.] was added to 100 parts of the mixture of the above polyether polyol and polyisocyanate compound, and a urethane resin as Comparative Example 2 A composition was obtained. Similarly, 30 parts of surface-treated calcium carbonate was added to obtain a urethane resin composition as Comparative Example 3.

Each of the thus obtained Example product, Comparative Example 1, Comparative Example 2 and Comparative Example 3 products was 23
C. and the thixotropy index (T.
I. ) And examined. Note that a BH type viscometer was used for the measurement. Table 1 shows the obtained results. "Table 1" Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Viscosity (2 rpm) 8000 5400 15900 46200 (20 rpm) 7000 5000 10400 28000 T.V. I. 1.14 1.08 1.53 1.65 However, 2 rpm and 20 rpm in the viscosity indicate the rotation speed of the rotor, respectively. The unit of viscosity is mPa ·
s and T.S. I. Is unitless.

Examples, Comparative Example 1, Comparative Example 2
5 equivalents of water with respect to 1 equivalent of isocyanate groups in the urethane prepolymer (isocyanate group-terminated prepolymer) for each of the product and Comparative Example 3, and further added 40
The mixture was stirred and mixed at 0 rpm for about 1 minute, and the viscosity and the thixotropy index (TI) 10 minutes after the start of mixing were examined. Table 2 shows the obtained results. "Table 2" Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Viscosity (2 rpm) 154000 7500 46080 355000 (20 rpm) 28000 6700 18000 65000 T.V. I. 5.50 1.12 2.56 5.46

From the results shown in Table 1, it was confirmed that the product of the example had a relatively low viscosity before adding water (before curing), and did not interfere with operations such as production, transfer, and mixing. Also, from the results shown in Table 2, the product of the example immediately thickened when water was added. I. As can be seen from the above, it was confirmed that high thixotropy was developed. On the other hand, Comparative Example 1 without the addition of hydrophilic fine silica had a lower viscosity than that of the Example before the addition of water. I. Is slightly lower, but after addition of water, especially T.V. I. Was scarcely increased, and thus almost no thixotropy was expressed. Further, in Comparative Examples 2 and 3 containing the surface-treated calcium carbonate, as in Comparative Example 2, if the viscosity before adding water was to be lowered, the T.V. I. Is low, and T.V. after adding water as in Comparative Example 3. I. It was found that increasing the viscosity increased the viscosity before adding water.

Therefore, the products of the examples of the present invention have a low viscosity in a state before use before curing, so that operations such as production, transfer and mixing can be performed well, and after addition of water, Since it immediately thickens and develops thixotropy, it has excellent workability such that it does not sag even when applied to a non-horizontal surface.

[0057]

As described above, the water-reaction-curable urethane resin composition of the present invention is a water-curable urethane resin composition containing an isocyanate group-terminated prepolymer and adding hydrophilic finely divided silica. Therefore, when water is added, the viscosity immediately increases due to the presence of the hydrophilic fine-grained silica, and thixotropicity is developed, whereby non-horizontal surfaces, such as vertical surfaces, hardly sag when applied. Becomes Therefore, especially when this is used as a paint, a coating material, a sealing material, or an adhesive, it is easy to use and excellent in workability.

In particular, if a carbon dioxide gas absorbent is added, a cured product free from foaming can be obtained even when the isocyanate group reacts with water due to the presence of the carbon dioxide gas absorbent. Even when cured on a wet substrate, a high-quality cured product free of bubbles, blisters, surface tack, and the like can be obtained.

Therefore, according to the water reaction-curable urethane resin composition of the present invention to which the hydrophilic finely divided silica is added,
Even when applied on a non-horizontal surface, it does not sag and cures as a uniform elastomer even in environments where conventional one-part moisture-curable or two-part reaction-curable urethane resins are difficult to apply. , Coating, sealing, bonding, etc., can be performed satisfactorily, which makes them useful as paints, coating materials, sealing materials, adhesives and the like.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 175/04 C09J 175/04 C09K 3/10 C09K 3/10 DQF term (Reference) 4H017 AA04 AA24 AA27 AA39 AB05 AC05 AC11 AC16 4J002 CK021 DE077 DJ016 FD016 FD030 FD090 FD207 FD310 GH01 GJ01 GJ02 4J034 CA04 CB03 CB07 DA01 DB03 DF01 DF02 DF16 DF17 DF20 DF22 DG03 DG04 DG06 HC13 HC12 HC13 HC12 HC12 HC13 HC12 HC13 HC12 HC12 HC13 HC12 HC12 HC12 HC71 HC73 JA42 KA01 KB02 KC17 KD02 KD12 MA03 MA04 RA07 RA08 4J038 DG121 DG131 GA03 GA11 HA196 HA446 KA03 KA08 KA20 LA06 MA14 NA08 NA23 NA24 NA26 PB02 PB05 4J040 EF111 EF131 GA05 GA11 GA20 HA156 HA03 LA05 NA03 LA05

Claims (11)

[Claims] 1. A water-reaction-curable urethane resin composition comprising a water-reaction-curable urethane resin composition containing an isocyanate group-terminated prepolymer, wherein hydrophilic fine-particle silica is added. 2. The method according to claim 2, wherein the hydrophilic fine silica is present in an amount of 0.3 parts by weight based on 100 parts by weight of the isocyanate group-terminated prepolymer.
The water-reaction-curable urethane resin composition according to claim 1, wherein the water-reaction-curable urethane resin composition is blended in a range of not less than 1 part by weight and not more than 14.0 parts by weight. 3. The hydrophilic fine-particle silica has a particle size of 6
The water-reaction-curable urethane resin composition according to claim 1, wherein the composition is in a range of not less than nm and not more than 30 nm. 4. The water-reaction-curable urethane resin composition according to claim 1, wherein the hydrophilic fine-particle silica has a specific surface area of 100 m ² / g or more as measured by a BET method. 5. The water reaction-curable urethane resin composition according to claim 1, wherein a carbon dioxide gas absorbent is added. 6. The water-reaction-curable urethane resin composition according to claim 5, wherein the carbon dioxide gas absorbent is a magnesium oxide having a specific surface area of 30 m ² / g or more by a BET method. 7. A paint using the water-reaction-curable urethane resin composition according to claim 1. 8. A coating material using the water-reaction-curable urethane resin composition according to claim 1. 9. A sealing material using the water-reaction-curable urethane resin composition according to claim 1. 10. An adhesive using the water-reaction-curable urethane resin composition according to claim 1. 11. A method for producing a cured product obtained by curing the water reaction-curable urethane resin composition according to claim 5 or 6,
Reacting the isocyanate group-terminated prepolymer with 5 equivalents or more of water as a curing agent relative to 1 equivalent of the isocyanate group in the isocyanate group-terminated prepolymer to cure the water-reaction-curable urethane resin composition. Characteristic cured product manufacturing method.