JP2007284493A - Water-dispersible polyisocyanate composition, water-based curable composition, water-based coating and water-based adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-dispersible polyisocyanate composition which is excellent in dispersibility and stability in water and is excellent in compatibility with water-based resins, to provide a water-based curable composition, to provide a water-based coating, and to provide a water-based adhesive. <P>SOLUTION: This water-dispersible polyisocyanate composition comprising a hydrophobic polyisocyanate and a vinylic polymer containing hydrophilic groups and isocyanate groups is characterized in that the hydrophobic polyisocyanate comprises a bifunctional polyisocyanate having a uretedione structure and/or an allophanate structure and a tri- or more-functional polyisocyanate, and the content of the bifunctional polyisocyanate is 10 to 70 wt.% based on the weight of the hydrophobic polyisocyanate. The water-based curable composition is characterized by comprising the water-dispersible polyisocyanate composition, and water and/or a water-based resin having active hydrogen-containing groups reacting with the isocyanate groups. The water-based coating is characterized by containing the water-based curable composition, and the water-based adhesive is characterized by containing the water-based curable composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a water-dispersible polyisocyanate composition useful in industrial fields such as paints, adhesives and fiber processing agents, an aqueous curable composition containing the polyisocyanate composition, and applications thereof. More specifically, a water-dispersible polyisocyanate composition containing a specific polyisocyanate useful for various applications such as water-based paints, adhesives, binders, and impregnating agents and a specific vinyl polymer, and an aqueous curing composition Articles, water-based paints and water-based adhesives.

In recent years, there has been a strong demand for reduction in the amount of volatile organic solvents used due to environmental problems. In order to meet this demand, in many fields, attempts have been made to make aqueous organic solvent-based compositions containing polyisocyanates. For example, a water-dispersible polyisocyanate composition obtained from a vinyl polymer having a hydrophilic group and a hydrophobic polyisocyanate has been disclosed. Specifically,
A water-dispersible polyisocyanate composition containing a vinyl polymer having a polyoxyalkylene group as a hydrophilic group and a polyisocyanate containing hexamethylene diisocyanate or tolylene diisocyanate is disclosed (for example, see Patent Document 1). .) However, the water-dispersible polyisocyanate composition disclosed in Patent Document 1 has a high viscosity. In actual use, it is necessary to add an organic solvent to lower the viscosity. Furthermore, the water resistance of a cured product (cured coating film) obtained by using the curable composition obtained from the water-dispersible polyisocyanate composition disclosed in Patent Document 1 and an aqueous resin having an active hydrogen-containing group, Abrasion resistance and appearance are greatly affected by the molecular weight of the aqueous resin used. Especially when a high molecular weight aqueous resin is used, the water resistance and abrasion resistance are excellent, but the appearance (gloss) is inferior. On the other hand, if the molecular weight of the aqueous resin is lowered, the appearance (gloss) of the cured coating film is excellent, but the coating film properties such as water resistance and abrasion resistance are inferior.

JP 2002-194045 A

  An object of the present invention is to provide a water-dispersible polyisocyanate composition in which a polyisocyanate can be easily dispersed in water without being diluted with an organic solvent. Provided is a water-dispersible polyisocyanate capable of providing a high-gloss curable composition comprising an aqueous resin having a group, and provides an aqueous curable composition excellent in dispersibility in water comprising the polyisocyanate composition and water. And providing an aqueous curable composition comprising the polyisocyanate composition and an aqueous resin having an active hydrogen-containing group, providing a cured product with excellent workability and excellent appearance, including the above-described aqueous cured composition It is to provide a water-based paint and a water-based adhesive.

  As a result of intensive studies, the inventors of the present invention include a bifunctional polyisocyanate having a uretdione structure and / or an allohanate structure as a hydrophobic polyisocyanate and a polyisocyanate having a trifunctional or higher functional isocyanate group as the hydrophobic polyisocyanate. Further, by using a polyisocyanate containing 10 to 70% by weight of the bifunctional polyisocyanate having the uretdione structure and / or the allophanate structure based on the total amount of the polyisocyanate, the organic solvent is not substantially contained. Excellent water dispersibility and stability, aqueous resin comprising the polyisocyanate composition and water is excellent in water stability and curability, from the polyisocyanate composition and an aqueous resin having an active hydrogen-containing group. Aqueous curable composition that can be used Long, excellent in curability, appearance, water resistance and found that such a cured product excellent in hardness, and have completed the present invention.

  That is, the present invention is a water-dispersible polyisocyanate composition comprising a hydrophobic polyisocyanate (A) and a vinyl polymer (B) containing a hydrophilic group and an isocyanate group. The isocyanate (A) contains a bifunctional polyisocyanate (A1) containing a uretdione structure and / or an allophanate structure and a polyisocyanate (A2) having a trifunctional or higher isocyanate group, and the bifunctional polyisocyanate. The present invention provides a water-dispersible polyisocyanate composition, which is a polyisocyanate having an isocyanate (A1) content of 10 to 70% by weight based on the weight of the hydrophobic polyisocyanate (A).

  Furthermore, the present invention provides an aqueous curable composition comprising the water-dispersible polyisocyanate composition and an aqueous resin (C) having an active hydrogen-containing group that reacts with an isocyanate group. is there.

  The present invention also provides an aqueous curable composition comprising the water-dispersible polyisocyanate composition and water.

  Moreover, this invention provides the water-based coating material and water-based adhesive characterized by containing the said water-based curable composition.

  According to the present invention, a water-dispersible polyisocyanate that is excellent in water dispersibility and stability without being diluted with an organic solvent, and that is excellent in compatibility with an aqueous resin having an active hydrogen-containing group. A composition can be provided. The aqueous curable composition comprising the polyisocyanate composition of the present invention and water is excellent in stability and curability to water, and the aqueous composition comprising the polyisocyanate composition of the present invention and an aqueous resin having an active hydrogen-containing group. The curable composition provides a cured product having a long pot life, excellent curability, and excellent appearance, water resistance and hardness. Furthermore, the water-based paint and the water-based adhesive containing the water-based curable composition of the present invention are excellent in water resistance and adhesiveness to an object to be coated.

  In the present invention, the hydrophobic polyisocyanate (A) is a polyisocyanate other than water-dispersible polyisocyanate modified with a hydrophilic group such as an ionic group or a nonionic group as mentioned in the above-mentioned reference. Is. In addition, as for polyisocyanate modified with polyoxyethylene glycol described in the above-mentioned references, there are cases in which there are approximately 5 or more ethylene oxides in the polyoxyethylene chain in polyoxyethylene glycol. The polyisocyanate is considered to be a hydrophilic polyisocyanate, and other than 5 polyisocyanates can be used as the hydrophobic polyisocyanate (A).

  The water-dispersible polyisocyanate composition of the present invention can be added with the above-described polyisocyanate modified with a water-dispersible hydrophilic group within a range not impairing the effects of the present invention. Water resistance, pot life, hardness, and weather resistance may deteriorate, and it is preferable not to add them.

  The hydrophobic polyisocyanate (A) of the present invention comprises a bifunctional hydrophobic polyisocyanate (A1) containing a uretdione structure and / or an allophanate structure and a hydrophobic polyisocyanate (A2) having a trifunctional or higher functional isocyanate group. It contains.

  The bifunctional hydrophobic polyisocyanate containing the uretdione structure used as the bifunctional hydrophobic polyisocyanate (A1) used in the present invention is an uretdione structure having the characteristic formula C2O2N2 (weight 84 per mole). It contains. As the bifunctional hydrophobic polyisocyanate having a uretdione structure, those containing 10 to 40% by weight of the uretdione structure on average in one molecule are preferable, and a water-dispersible polyisocyanate composition having good water dispersibility is preferable. What contains 25 to 35 weight% is more preferable at the point obtained.

  When a bifunctional hydrophobic polyisocyanate containing a uretdione structure is used as the bifunctional hydrophobic polyisocyanate (A1) used in the present invention, the formula C2O2N2 (per mole) in the hydrophobic polyisocyanate (A) The content of the uretdione structure consisting of the weight 84) is such that a water-dispersible polyisocyanate composition having good water dispersibility is obtained, and the curability with an aqueous resin containing an active hydrogen-containing group and the appearance of the cured coating film are improved. 1 to 28% by weight is preferable from the viewpoint of superiority, and 2.5 to 25% by weight is more preferable from the viewpoint of good water dispersibility.

  The bifunctional hydrophobic polyisocyanate containing an allophanate structure used as the bifunctional hydrophobic polyisocyanate (A1) used in the present invention is an allophanate structure consisting of the formula C2HO3N2 (weight 101 per mole). It contains. The bifunctional hydrophobic polyisocyanate containing an allophanate structure is preferably a water-dispersible polyisocyanate composition having an average of 5 to 35% by weight of the allohanate structure in one molecule and having good water dispersibility. The content of 15 to 30% by weight is more preferable in that it is obtained.

  When a bifunctional hydrophobic polyisocyanate containing an allophanate structure is used as the bifunctional hydrophobic polyisocyanate (A1) of the present invention, the formula C2HO3N2 (per mole) in the hydrophobic polyisocyanate (A) is used. The content of the allohanate structure consisting of weight 101) gives a water-dispersible polyisocyanate composition with good water dispersibility, and is excellent in curability with an aqueous resin containing an active hydrogen-containing group and in the appearance of the cured coating film. In this respect, 0.5 to 25% by weight is preferable, and 2 to 19% by weight is more preferable from the viewpoint of good water dispersibility.

  As the polyisocyanate used in the bifunctional hydrophobic polyisocyanate (A1) of the present invention, those having the above uretdione structure and those having the above allophanate structure can be used in combination.

  The content of the polyisocyanate (A1) in the hydrophobic polyisocyanate (A) needs to be 10 to 70% by weight based on the weight of the hydrophobic polyisocyanate (A). When the content of the polyisocyanate (A1) in the hydrophobic polyisocyanate (A) is less than 10% by weight, the dispersibility is poor and the workability is deteriorated, and a stirrer having a strong shear force to disperse in water is used for a long time. It is not preferable because it must be used. In addition, it is not preferable because it often has an adverse effect on the performance of a cured coating film with a composition containing an aqueous resin containing an active hydrogen-containing group due to poor stirring (dispersion). When the content of the polyisocyanate (A1) in the hydrophobic polyisocyanate (A) is more than 70% by weight, the hardness and weather resistance of the cured coating film with a curable composition containing an aqueous resin having an active hydrogen-containing group This is not preferable because the properties and water resistance deteriorate. The content of the polyisocyanate (A1) in the hydrophobic polyisocyanate (A) is more preferably 20 to 60% by weight based on the weight of the hydrophobic polyisocyanate (A).

  The content of the polyisocyanate (A2) in the hydrophobic polyisocyanate (A) is 40 to 80% by weight based on the weight of the hydrophobic polyisocyanate (A), and the active hydrogen-containing group. It is preferable from the reason that the balance of performance such as water resistance, appearance, weather resistance, hardness and the like of the curable composition obtained from the water-based resin having the above is excellent, and more preferably 50 to 75% by weight.

  The bifunctional polyisocyanate having an allophanate structure used as the polyisocyanate (A1) can be obtained, for example, by reacting 2 mol of diisocyanate with 1 mol of monoalcohol.

  Examples of the diisocyanate include 1,4-tetramethylene diisocyanate, ethyl (2,6-diisocyanate) hexanoate, 1,6-hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, and 2,2,4-trimethyl. Aliphatic diisocyanates such as hexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate;

1,3-bis (isocyanatomethylcyclohexane), 1,4-bis (isocyanatomethylcyclohexane), 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl ( Alicyclic diisocyanates such as 3-isocyanatomethyl) cyclohexyl isocyanate, dicyclohexylmethane-4,4′-diisocyanate, 2,5-diisocyanatomethylnorbornane, 2,6-diisocyanatomethylnorbornane;

m-phenylene diisocyanate, p-phenylene diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, diphenylmethane-4,4′-diisocyanate, naphthalene-1,5-diisocyanate, diphenyl-4,4′- Aromatic diisocyanates such as diisocyanate, 4,4′-diisocyanate-3,3′-dimethyldiphenyl, 3-methyl-diphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate and the like.

  Among the polyisocyanates having an allophanate structure obtained by using the above-mentioned diisocyanate, it is excellent in light resistance of a curable composition with an aqueous resin containing an active hydrogen-containing group and stability of an isocyanate group in water. A polyisocyanate having a uretdione structure obtained by using an aliphatic diisocyanate or an alicyclic diisocyanate is preferred because of its long time.

  The bifunctional polyisocyanate containing a uretdione structure used as the polyisocyanate (A1) can be obtained, for example, by reacting 2 mol of diisocyanate.

  As said diisocyanate, the diisocyanate which can be used for preparation of the polyisocyanate which has the said allohanate structure can be used, for example.

  Among polyisocyanates having an allophanate structure and / or uretdione structure obtained by using the above-mentioned diisocyanate, the stability of the isocyanate group in water and the light resistance of the curable composition with an aqueous resin containing an active hydrogen-containing group From the viewpoint of pot life, a polyisocyanate having an allophanate structure and / or a uretdione structure obtained using an aliphatic diisocyanate or an alicyclic diisocyanate is preferable.

  Examples of the monoalcohol include methanol, ethanol, n-propanol, n-butanol, isobutanol, n-pentanol, n-hexanol, n-octanol, n-nonanol, n-decanol, isopentanol, 2- Primary alcohols such as ethyl-hexanol;

Secondary alcohols such as isopropanol, sec-butanol, 1-methyl-pentanol, 1-methylhexanol, cyclopentanol, cyclohexanol;

tertiary alcohols such as t-butanol, t-pentanol, 1,1-dimethylbutanol;

Examples thereof include monoalkoxy (di) alkylene glycols such as methoxyethanol, ethoxyethanol, butoxyethanol, methoxypropanol, ethoxypropanol, propoxypropanol, methoxybutanol, methoxydiethylene glycol, butoxydiethylene glycol, and methoxydipropylene glycol.

  Among the monoalcohols, a water-dispersible polyisocyanate composition obtained has good water dispersibility, so that a monoalcohol having a molecular weight of 200 or less is preferable, and a monoalcohol having a molecular weight of 32-150 is more preferable.

  As the polyisocyanate (A1) used in the present invention, a polyisocyanate having an allophanate structure is preferable because a water-dispersed isocyanate composition having excellent temporal stability and thermal stability can be obtained.

  Examples of the tri- or higher functional polyisocyanate (A2) used in the present invention include 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 2-isocyanatoethyl ( Aliphatic triisocyanates such as 2,6-diisocyanato) hexanoate;

Aromatic triisocyanates such as triphenylmethane triisocyanate, tris (isocyanatophenyl) thiophosphate;

Isocyanate prepolymer obtained by reacting the triisocyanate or, for example, one or more isocyanates selected from diisocyanates used for the preparation of the polyisocyanate (A1) with bifunctional or higher alcohols, or allophanate type Polyisocyanate;

A polyisocyanate having an isocyanurate structure obtained by cyclizing and trimerizing one or more isocyanates selected from the triisocyanate or the diisocyanate used for the preparation of the polyisocyanate (A1);

  A polyisocyanate having a burette structure obtained by reacting one or more kinds of isocyanate selected from the triisocyanate or the diisocyanate used for the preparation of the polyisocyanate (A1) with water; Examples thereof include a mixture of the above isocyanates.

  As the polyisocyanate (A2) used in the present invention, when the curable composition containing the water-dispersible polyisocyanate composition obtained in the present invention is used as a paint, the stability of the isocyanate group in water is good. From the viewpoint of good weather resistance of the coating film, an aliphatic trifunctional or higher polyisocyanate or an alicyclic trifunctional or higher polyisocyanate is preferable, and can be obtained using an aliphatic diisocyanate or triisocyanate. An isocyanurate type polyisocyanate obtained by using an isocyanurate type polyisocyanate and an alicyclic diisocyanate or triisocyanate is more preferable.

  The hydrophobic polyisocyanate (A) used in the present invention may contain the polyisocyanate (A1) and the polyisocyanate (A2), but the uretdione structure derived from the polyisocyanate (A2) in the hydrophobic polyisocyanate (A). The content of the allophanate structure is preferably 2 to 25% by weight because the water dispersibility of the polyisocyanate composition of the present invention is good and the curability and appearance of the aqueous curable composition of the present invention are excellent. .

  The hydrophobic polyisocyanate (A) used in the present invention may contain the polyisocyanate (A1) and the polyisocyanate (A2), but the water dispersibility of the polyisocyanate composition of the present invention and the aqueous curable composition of the present invention. A monofunctional isocyanate, a polyisocyanate other than the polyisocyanate (A1) and the polyisocyanate (A3), or the like may be added as long as the performance of the product is not deteriorated.

  Examples of the vinyl polymer (B) containing a hydrophilic group and an isocyanate group [hereinafter referred to as NCO group-containing vinyl polymer (B)] used in the present invention include an acrylic containing a hydrophilic group and an isocyanate group. Polymer, fluoroolefin polymer containing hydrophilic group and isocyanate group, vinyl ester polymer containing hydrophilic group and isocyanate group, aromatic vinyl polymer containing hydrophilic group and isocyanate group, Examples thereof include a polyolefin-based polymer containing a hydrophilic group and an isocyanate group. The NCO group-containing vinyl polymer (B) used in the present invention has good compatibility when the water-dispersible polyisocyanate composition of the present invention is used as a curing agent and an acrylic polymer is used as a base resin. In particular, an acrylic polymer containing a hydrophilic group and an isocyanate group and a fluoroolefin polymer containing a hydrophilic group and an isocyanate group are preferred.

  Examples of the hydrophilic group possessed by the NCO group-containing vinyl polymer (B) include an anionic group, a cationic group, and a nonionic group. Among these, a nonionic group is preferable from the viewpoint of water resistance and weather resistance of a cured coating film with an aqueous resin having an active hydrogen-containing group described later. More preferable are polyoxyalkylene groups whose ends are blocked with alkoxy groups, polyoxyalkylene groups blocked with substituted alkoxy groups, polyoxyalkylene groups blocked with ester groups, and the like. It is an oxyalkylene group. Typical examples thereof include polyoxyethylene groups and poly (oxyethylene-oxypropylene) groups such as those obtained by random copolymerization of the aforementioned oxyalkylene moieties, and polyoxyethylene-polyoxypropylene groups. And the like, in which different polyoxyalkylene groups are bonded in a block form. Among these polyoxyalkylene groups, 5 to 20 consecutive oxy groups are preferred because the water dispersibility of the polyisocyanate composition of the present invention is good and the isocyanate group is excellent in stability in water. It contains ethylene units.

  Among the groups used for the above-mentioned end-capping, the water dispersibility of the polyisocyanate composition of the present invention is good, so that an alkoxy group or a substituted alkoxy group is preferable, and an alkoxy group is particularly preferable. It is. Representative examples of alkoxy groups include lower alkoxy groups such as methoxy, ethoxy, and butoxy groups.

  A suitable amount of the hydrophilic group introduced into the NCO group-containing vinyl polymer (B) allows the hydrophobic polyisocyanate (A) to be easily dispersed in water, and the water-dispersible polyisocyanate composition of the present invention. The amount may be in a range that does not impair the stability of the isocyanate group contained in the dispersion obtained by dispersing in water. The preferred amount is 10 to 80% by weight of the NCO group-containing vinyl polymer (B), the more preferred amount is 20 to 70% by weight, and the most preferred amount is 30 to 60% by weight. %.

  Examples of the isocyanate group introduced into the NCO group-containing vinyl polymer (B) include an isocyanate group bonded to an alkyl group, an isocyanate group bonded to a cycloalkyl group, an isocyanate group bonded to an aryl group, and a cycloalkyl group. Examples thereof include an isocyanate group bonded to a substituted alkyl group and an isocyanate group bonded to an alkyl group substituted with an aryl group.

  A suitable amount of isocyanate group introduced into the NCO group-containing vinyl polymer (B) is that the NCO group-containing vinyl polymer (B) is an active hydrogen of an aqueous resin (C) having an active hydrogen-containing group described later or It may be an amount that can react with water and participate in crosslinking, and that does not impair the stability of the water-dispersible polyisocyanate composition of the present invention. The preferred amount is 0.05 to 6 mol, preferably 0.1 to 5.0 mol, more preferably 0.2 to 4 mol per 1000 g of the NCO group-containing vinyl polymer (B). 0.0 mole.

In order to prepare the NCO group-containing vinyl polymer (B) used in the present invention, for example, (1) a vinyl-based polymer containing a hydrophobic polyisocyanate, an active hydrogen-containing group that reacts with an isocyanate group, and a hydrophilic group. A method of reacting a polymer [hereinafter referred to as method (1)], (2) a method of copolymerizing a vinyl monomer containing an isocyanate group and a vinyl monomer containing a hydrophilic group [hereinafter referred to as method (2) )] And the like can be applied.

Hereinafter, the method (1) will be described.
In the method (1), a polyisocyanate is reacted with a vinyl polymer (b) having an active hydrogen-containing group that reacts with an isocyanate group and a hydrophilic group [hereinafter referred to as an active hydrogen group-containing vinyl polymer (b)]. It is characterized by that. When the polyisocyanate and the vinyl polymer (b) are reacted with each other, the NCO group is reacted with a molar ratio in which the isocyanate group is excessive with respect to the active hydrogen group-containing group of the vinyl polymer (b). It is preferable because the water-dispersible polyisocyanate composition of the present invention can be easily prepared simultaneously with the preparation of the vinyl-containing polymer (B).

  Examples of the polyisocyanate used in the method (1) include hydrophobic polyisocyanates (A) such as polyisocyanates other than the polyisocyanates (A1), polyisocyanates (A2), (A1) and (A2) described above. Etc. The polyisocyanate to be used may be the same as that used as the hydrophobic polyisocyanate (A) or may be different. Moreover, you may use together the polyisocyanate which has a hydrophilic group in the range which does not impair the effect of this invention.

  In the method (1), the active hydrogen group-containing vinyl polymer (b) is reacted with the isocyanate group of the hydrophobic polyisocyanate by reacting the active hydrogen group-containing group with an excess of isocyanate groups. Reacts to produce a vinyl polymer (B) containing a hydrophilic group and an isocyanate group. Further, the unreacted product of this reaction, that is, the hydrophobic polyisocyanate remains in the reaction system. Therefore, the hydrophobic polyisocyanate used is selected so that the content of the polyisocyanate (A1) in the reaction system is 10 to 70% by weight based on the weight of the hydrophobic polyisocyanate (A) as the hydrophobic polyisocyanate. Thus, the water-dispersible polyisocyanate composition of the present invention can be obtained.

  In the method (1), the proportion of the hydrophobic polyisocyanate and the active hydrogen group-containing vinyl polymer (b) used in the reaction so that the isocyanate group is excessive with respect to the active hydrogen group-containing group is as follows: It is preferably used such that the ratio of isocyanate group / active hydrogen-containing group is 10 to 350 in terms of molar ratio, more preferably 15 to 300, and even more preferably 20 to 250. .

  In order to react the hydrophobic polyisocyanate with the active hydrogen group-containing vinyl polymer (b), for example: 1. Charge both components together and react. 2. reacting a hydrophobic polyisocyanate while adding a solution of an active hydrogen group-containing vinyl polymer (b); Various methods such as reacting while adding a hydrophobic polyisocyanate to the solution of the active hydrogen group-containing vinyl polymer (b) can be applied.

  And from the point which can suppress the production | generation of a gel thing among these, 1. Or 2. This method is preferred. And in performing such reaction of both components, it is preferable to heat and stir the mixture of both components at 50-130 degreeC for 0.5 to 20 hours by inert gas atmosphere. Moreover, in performing this reaction, you may add the various catalysts which accelerate reaction of an isocyanate group and an active hydrogen containing group.

  In preparing the active hydrogen group-containing vinyl polymer (b), a hydrophobic polyisocyanate is used in place of a part of the solvent or the total amount of the solvent, and the active hydrogen group-containing vinyl polymer (b) is used. The water-dispersible polyisocyanate composition of the present invention can also be prepared by proceeding in parallel with the reaction of the active hydrogen group-containing vinyl polymer (b) and the hydrophobic polyisocyanate.

  A mixture obtained by further adding the hydrophobic polyisocyanate (A) to the water-dispersible polyisocyanate composition prepared as described above can also be used as the water-dispersible polyisocyanate composition of the present invention. Can

  Examples of the active hydrogen-containing group possessed by the active hydrogen group-containing vinyl polymer (b) include a hydroxyl group, a carboxyl group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, a sulfinic acid group, a mercapto group, a silanol group, and an active group. Examples include a methylene group, a carbamate group, a ureido group, a carboxylic acid amide group, and a sulfonic acid amide group. Of these, a hydroxyl group, an amino group, a carboxyl group and an active methylene group are preferred from the viewpoint of ease of introduction, and particularly preferred are a hydroxyl group and a carboxyl group. And these various active hydrogen containing groups may each be introduce | transduced independently, and 2 or more types may be introduce | transduced.

  Examples of the hydrophilic property of the active hydrogen group-containing vinyl polymer (b) include an anionic group, a cationic group, and a nonionic group. Among these, nonionic groups are preferable from the viewpoint of water resistance and weather resistance of a cured coating film with an aqueous resin containing an active hydrogen-containing group. More preferred are polyoxyalkylene groups whose ends are blocked with various groups such as alkoxy groups, substituted alkoxy groups, ester groups and the like.

The active hydrogen group-containing vinyl polymer (b) can be prepared, for example, by the following method.
1. A method in which an active hydrogen group-containing vinyl monomer and a hydrophilic group-containing vinyl monomer are essential components and copolymerized with other vinyl monomers as necessary.
2. A method of reacting a vinyl polymer containing a functional group prepared in advance with a compound having a functional group that reacts with the functional group and a hydrophilic group.

  Because of the simplicity among the above methods, 1. This method is preferred. Hereinafter, 1. Will be described in detail.

  Examples of the active hydrogen group-containing polymerizable monomer include a hydroxyl group-containing polymerizable monomer, a carboxyl group-containing polymerizable monomer, an amino group-containing polymerizable monomer, and an active methylene group-containing polymerizable monomer. Etc.

  Examples of the hydroxyl group-containing polymerizable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, methyl (2-hydroxymethyl) acrylate, ethyl (2-hydroxymethyl) acrylate, butyl (2-hydroxymethyl) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, glycerin (Meth) acrylic acid esters such as mono (meth) acrylate, phthalic acid mono (2-hydroxypropyl) -mono [2- (meth) acryloyloxy] ethyl ester, 2-hydroxy-3-phenoxypropyl (meth) acrylate, etc. Ethers;

Mono (meth) acrylates of polyoxyalkylene glycols such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate;

Allyl compounds such as allyl alcohol and 2-hydroxyethyl allyl ether; vinyl ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether and 6-hydroxyhexyl vinyl ether; N-methylol (meth) acrylamide, N-methylolcrotonamide Unsaturated carboxylic acid amide compounds such as: Unsaturated fatty acids such as ricinoleic acid; Unsaturated fatty acid esters such as alkyl ricinoleate; Single amount obtained by addition reaction of various hydroxyl group-containing monomers with ε-caprolactone Examples include the body.

  Examples of the carboxyl group-containing polymerizable monomer include (meth) acrylic acid, 2-carboxyethyl acrylate, crotonic acid, vinyl acetic acid, monovinyl adipate, monovinyl sebacate, monomethyl itaconate, monomethyl maleate, and fumaric acid. Monomethyl, succinic acid mono [2- (meth) acryloyloxyethyl], phthalic acid mono [2- (meth) acryloyloxyethyl], hexahydrophthalic acid mono [2- (meth) acryloyloxyethyl], sorbic acid, etc. Unsaturated monocarboxylic acids; unsaturated dicarboxylic acids such as itaconic acid, maleic acid and fumaric acid.

  Examples of the amino group-containing polymerizable monomer include 2- (N-methylamino) ethyl (meth) acrylate, 2- (N-ethylamino) ethyl (meth) acrylate, and 2- (Nn-butyl). Amino) ethyl (meth) acrylate, 2- (N-tert-butylamino) ethyl methacrylate, 2- (N-methylamino) ethyl crotonate, 2- (N-ethylamino) ethyl crotonate, 2- (N- Secondary amino group-containing vinyl monomers such as butylamino) ethyl crotonate.

  Examples of the active methylene group-containing polymerizable monomer include vinyl acetoacetate, 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 3-acetoacetoxypropyl (meth) acrylate, 3 -Acetoacetoxybutyl (meth) acrylate, 4-acetoacetoxybutyl (meth) acrylate, allyl acetoacetate, 2,3-di (acetoacetoxy) propyl methacrylate. These may be used alone or in combination of two or more.

  The active hydrogen group-containing polymerizable monomer described above may be used alone or in combination of two or more.

  Examples of the hydrophilic group-containing polymerizable monomer include groups in which oxyalkylene moieties such as polyoxyethylene groups and poly (oxyethylene-oxypropylene) groups are randomly copolymerized, and polyoxyethylene-polyoxypropylene. (Meth) acrylic acid esters having a polyoxyalkylene group such as a group in which different polyoxyalkylene groups such as groups are bonded in a block form; oxyalkylene such as a polyoxyethylene group or a poly (oxyethylene-oxypropylene) group Crotonic acid esters having a polyoxyalkylene group such as a group in which different parts are randomly copolymerized or a group in which different polyoxyalkylene groups such as polyoxyethylene-polyoxypropylene groups are bonded in a block form; , Poly (oxyethylene-oxypropylene) groups, etc. Itaconic acid esters having a polyoxyalkylene group such as a group in which xyalkylene moieties are randomly copolymerized or a group in which different polyoxyalkylene groups such as polyoxyethylene-polyoxypropylene groups are bonded in a block form; Groups in which oxyalkylene moieties such as ethylene groups and poly (oxyethylene-oxypropylene) groups are randomly copolymerized, groups in which different polyoxyalkylene groups such as polyoxyethylene-polyoxypropylene groups are bonded in block form, etc. Fumaric acid esters having a polyoxyalkylene group; groups in which oxyalkylene moieties such as polyoxyethylene groups and poly (oxyethylene-oxypropylene) groups are randomly copolymerized, polyoxyethylene-polyoxypropylene groups, etc. Different polyoxyalkylene groups Vinyl ethers having a polyoxyalkylene group such as a group attached to the block-shaped and the like.

  When a monomer containing polyoxyalkylene is used as the hydrophilic group-containing polymerizable monomer, a monomer containing polyoxyalkylene whose end is blocked is preferred. Examples of the polyoxyalkylene group whose end is blocked include, for example, a monomer containing a polyoxyalkylene group whose end is blocked with an alkoxy group, and a monomer containing a polyoxyalkylene group blocked with a substituted alkoxy group And monomers containing a polyoxyalkylene group blocked with an ester group. Among the polyoxyalkylene groups, preferred are 5 to 20 consecutive oxyethylene units because the water dispersibility of the polyisocyanate composition of the present invention is good and the isocyanate group is excellent in stability in water. It contains.

  Among the groups used for end-capping the polyoxyalkylene group described above, an alkoxy group or a substituted alkoxy group is preferable, and an alkoxy group is particularly preferable. Representative examples of alkoxy groups include lower alkoxy groups such as methoxy, ethoxy, and butoxy groups.

  The (meth) acrylic acid esters include various monoalkoxy compounds such as monomethoxylated polyethylene glycol, monoalkoxylated polypropylene glycol, and monoalkoxylated products of polyether diols having both oxyethylene units and oxypropylene units. An ester of a modified polyether diol and (meth) acrylic acid can also be exemplified.

  The amount of active hydrogen groups introduced into the active hydrogen group-containing vinyl polymer (b) is determined by the water dispersibility of the water-dispersible polyisocyanate composition of the present invention and the isocyanate contained in the aqueous dispersion of the composition. From the point that stability of the group is good, 0.05 to 5 mol is preferable, more preferably 0.1 to 2 mol, and further 0.2 to 1 mol is more preferable per 1000 g of the active hydrogen group-containing vinyl polymer (b). preferable.

  The amount of the hydrophilic group introduced into the active hydrogen group-containing vinyl polymer (b) is determined by reacting the active hydrogen group-containing vinyl polymer (b) with the hydrophobic polyisocyanate. The amount may be within a range that does not impair the stability of the isocyanate group contained in the dispersion obtained by easily dispersing the isocyanate composition in water and dispersing the composition in water. The preferred amount is 20 to 80% by weight of the weight of the active hydrogen group-containing vinyl polymer (b), the more preferred amount is 30 to 70% by weight, and the most preferred amount is 40 to 70% by weight. %.

  In the water-dispersible polyisocyanate composition of the present invention, the NCO group-containing vinyl polymer (B) has the ability to disperse the hydrophobic polyisocyanate (A) in water. Accordingly, the NCO group-containing vinyl polymer (B) has a function of imparting excellent water dispersibility to the water-dispersible polyisocyanate composition of the present invention. Further, the NCO group-containing vinyl polymer (B) imparts stability to water of isocyanate groups contained in the aqueous dispersion of the composition. Furthermore, since the NCO group-containing vinyl polymer (B) also has an isocyanate group, the aqueous curable composition of the present invention comprising the aqueous resin (C) having an active hydrogen-containing group described later or water and a polyisocyanate composition. The composition has excellent curability. And the said aqueous curable composition gives the hardened | cured material which has the outstanding performance.

  Further, when a hydrophobic group having 4 or more total carbon atoms is introduced into the NCO group-containing vinyl polymer (B), the water-dispersible polyisocyanate composition of the present invention is further improved in water dispersibility. In addition, it is preferable in that the stability of the isocyanate group contained in the aqueous dispersion of the composition to water can be further improved.

  The hydrophobic group having 4 or more total carbon atoms introduced into the NCO group-containing vinyl polymer (B) is other than a hydrophilic group such as an ionic group or a polyoxyalkylene group, Moreover, it has an exclusive structure that prevents attacks on the NCO group from water by having four or more total carbon atoms. Typical examples of the hydrophobic group having 4 or more total carbon atoms include an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, 2- An alkyl group having 4 or more carbon atoms such as ethylhexyl group, n-octyl group, n-dodecyl group, n-octadecyl group; cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, dicyclopentanyl group, bornyl group A cycloalkyl group having 4 or more carbon atoms, such as an isobornyl group;

An alkyl group substituted by a cycloalkyl group such as a cyclopentylmethyl group, a cyclohexylmethyl group, a 2-cyclopentylethyl group, a 2-cyclohexylethyl group; a total number of carbon atoms such as a phenyl group, a 4-methylphenyl group, a 1-naphthyl group; Examples thereof include 6 or more aryl groups or substituted aryl groups; aralkyl groups such as benzyl group and 2-phenylethyl group.

  Among the various hydrophobic groups having 4 or more total carbon atoms as listed above, preferred are those having 4 to 22 total carbon atoms, and particularly preferred are those having 5 to 5 total carbon atoms. 18 things. Of these hydrophobic groups, an alkyl group, a cycloalkyl group or an alkyl group substituted with a cycloalkyl group is particularly preferred.

  In order to obtain an NCO group-containing vinyl polymer into which a hydrophobic group having 4 or more total carbon atoms has been introduced as the NCO group-containing vinyl polymer (B), for example, the active hydrogen group-containing vinyl polymer ( In preparing b), a vinyl monomer having a hydrophobic group having 4 or more total carbon atoms may be used for copolymerization.

  Typical examples of the vinyl monomer having a hydrophobic group having 4 or more total carbon atoms include n-butyl (meth) acrylate, iso-butyl (meth) acrylate, and tert-butyl. (Meth) acrylic acid esters having an alkyl group having 4 to 22 carbon atoms in total such as (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, octadecyl (meth) acrylate;

Various cycloalkyl (meth) acrylates such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate; cyclopentylmethyl (meth) acrylate Cycloalkylalkyl (meth) acrylates such as cyclohexylmethyl (meth) acrylate and 2-cyclohexylethyl (meth) acrylate; various aralkyl (meth) acrylates such as benzyl (meth) acrylate and 2-phenylethyl (meth) acrylate ) Acrylates;

Various aromatic vinyl monomers such as styrene, p-tert-butylstyrene, α-methylstyrene, vinyltoluene, etc .; the total number of carbon atoms such as vinyl pivalate, vinyl versatate or vinyl benzoate 5 or more carboxylic acid vinyl esters; various crotonic acid esters having an alkyl group having 4 to 22 carbon atoms such as crotonic acid-n-butyl and crotonic acid-2-ethylhexyl;

Various unsaturated dibasic acid diesters having at least one alkyl group having 4 to 22 carbon atoms, such as di-n-butyl maleate, di-n-butyl fumarate, di-n-butyl itaconate; n -Various alkyl vinyl ethers having an alkyl group having 4 to 22 carbon atoms such as butyl vinyl ether and n-hexyl vinyl ether; various cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether, 4-methylcyclohexyl vinyl ether, etc. Is mentioned.

  When a hydrophobic group having 4 or more carbon atoms in total is introduced into the active hydrogen group-containing vinyl polymer (b), the preferred amount of introduction is the water dispersion of the water-dispersible polyisocyanate composition of the present invention. From the viewpoint of improving the stability of the isocyanate group contained in the aqueous dispersion of the composition and the composition, the weight ratio of the hydrophobic group contained in the vinyl polymer (b) is preferably 5 to 60% by weight. 10 to 60% by weight is more preferable, 10 to 50 is still more preferable, and 20 to 50% by weight is particularly preferable.

  The above-mentioned NCO group-containing vinyl polymer (B) has an isocyanate group in the molecule, but further has an NCO into which a reactive functional group such as a blocked active hydrogen-containing group, an epoxy group, or a hydrolyzable silyl group has been introduced. A group-containing vinyl polymer is preferred. Since these reactive functional groups are involved in the crosslinking reaction together with the isocyanate group, the curability of the aqueous curable composition of the present invention can be improved to give a cured product having better performance.

  Representative examples of the blocked active hydrogen-containing group include a blocked hydroxyl group, a blocked carboxyl group, and a blocked amino group. Among such blocked active hydrogen-containing groups, representative examples of the blocked hydroxyl group include, for example, a trimethylsilyl ether group, a triethylsilyl ether group, a dimethylcyclohexylsilyl ether group, and a dimethyl-tert-butylsilyl ether group. Hydroxyl groups blocked with triorganosilyl groups such as acetals or ketals obtained by adding α, β-unsaturated ether compounds such as methyl vinyl ether, ethyl vinyl ether, 2-methoxypropene, dihydrofuran, dihydropyran to the hydroxyl groups Examples include blocked hydroxyl groups.

  Representative examples of the blocked carboxyl group include a carboxyl group blocked as a triorganosilyl ester such as a trimethylsilyl ester group, a triethylsilyl ester group, a dimethylcyclohexylsilyl ester group, or a dimethyl-tert-butylsilyl ester group. A carboxyl group blocked as a hemiacetal ester or hemiketal ester obtained by adding an α, β-unsaturated ether compound such as methyl vinyl ether, ethyl vinyl ether, 2-methoxypropene, dihydrofuran, dihydropyran to the carboxyl group; Is mentioned.

  Representative examples of the blocked amino group include bis (triorganosilyl) amino groups such as bis (trimethylsilyl) amino group, bis (triethylsilyl) amino group, and bis (dimethyl-tert-butylsilyl) amino group. An amino group blocked as an aldimine by reacting the amino group with an aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde;

An amino group blocked as a ketimine obtained by reacting an amino group with a ketone compound such as acetone, methyl ethyl ketone, or methyl isobutyl ketone; an aldehyde compound as listed above for use in converting the amino group to aldimine or ketimine Or the amino group etc. which blocked the ketone compound as oxazolidine obtained by making 2-amino alcohol react.

  Of the various blocked active hydrogen-containing groups listed above, hydroxyl groups blocked with triorganosilyl groups are particularly preferred. And since the hydroxyl group blocked with such a triorganosilyl group has hydrophobicity, the water-dispersible polyisocyanate composition of the present invention is introduced by introducing this group into the NCO group-containing vinyl polymer (B). In addition, it is possible to impart further excellent water dispersibility, and it is possible to further improve the stability of the isocyanate group contained in the aqueous dispersion of the water-dispersible polyisocyanate composition.

  Typical examples of the epoxy group include a glycidyl group, a methyl glycidyl group, and an epoxycyclohexyl group.

  Among the functional groups described above, the hydrolyzable silyl group is an alkoxy group, a substituted alkoxy group, a phenoxy group, an iminooxy group, an alkenyloxy group, which is a group that generates a hydroxyl group that is eliminated by hydrolysis and bonded to a silicon atom. This refers to a silyl group to which a hydrolyzable group such as a halogen atom is bonded. Among such silyl groups, an alkoxysilyl group having an alkoxy group or a substituted alkoxy group bonded as a hydrolyzable group is particularly preferable. Representative examples of the alkoxysilyl group include trimethoxysilyl group, triethoxysilyl group, tri-n-propoxysilyl group, tri-n-butoxysilyl group, methyldimethoxysilyl group, ethyldimethoxysilyl group, dimethylmethoxysilyl. Group, tris (2-methoxyethoxy) silyl group and the like.

  Of the above-described reactive functional groups introduced into the NCO group-containing vinyl polymer (B), particularly preferred are blocked active hydrogen-containing groups and epoxy groups.

  When functional groups such as the above-mentioned blocked active hydrogen-containing groups, epoxy groups, hydrolyzable silyl groups are introduced into the NCO group-containing vinyl polymer (B), the amount of these functional groups introduced is the present invention. 0.05 to 2 per 1000 g of the NCO group-containing vinyl polymer (B) from the viewpoint that the water dispersibility of the water dispersible polyisocyanate composition and the curability of the aqueous curable composition of the present invention are improved. Mole is preferable, and 0.1 to 1 mol is more preferable.

  In order to prepare an NCO group-containing vinyl polymer into which a reactive functional group such as a blocked active hydrogen-containing group, an epoxy group or a hydrolyzable silyl group is introduced as the NCO group-containing vinyl polymer (B), for example, In preparing the active hydrogen group-containing vinyl polymer (b), it is easy to introduce it by copolymerizing a vinyl monomer containing a functional group as described above.

  Typical examples of vinyl monomers having a hydroxyl group blocked with a triorganosilyl group include 2-trimethylsiloxyethyl (meth) acrylate, 2-trimethylsiloxypropyl (meth) acrylate, and 4-trimethylsiloxy. Butyl (meth) acrylate, 2-triethylsiloxyethyl (meth) acrylate, 2-tributylsiloxypropyl (meth) acrylate or 3-triphenylsiloxypropyl (meth) acrylate, 2-trimethylsiloxyethyl vinyl ether, 4-trimethylsiloxybutyl vinyl ether Etc.

  Typical vinyl monomers containing a silyl ester group include, for example, trimethylsilyl (meth) acrylate, dimethyl-tert-butylsilyl (meth) acrylate, dimethylcyclohexylsilyl (meth) acrylate, trimethylsilyl crotonate, adipine And monovinyl-monotrimethylsilyl ester of acid.

  Typical examples of vinyl monomers containing a hemiacetal ester group or a hemiketal ester group include 1-methoxyethyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate, and 2-methoxy-2. Examples include-(meth) acryloyloxypropane and 2- (meth) acryloyloxytetrahydrofuran.

  Typical vinyl monomers containing an epoxy group include, for example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, glycidyl vinyl ether, allyl glycidyl ether. Etc.

  Representative vinyl monomers having a hydrolyzable silyl group include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinyltris (2-methoxyethoxy) silane, and allyltrimethoxysilane. 2-trimethoxysilylethyl vinyl ether, 3-trimethoxysilylpropyl vinyl ether,

3- (methyldimethoxysilyl) propyl vinyl ether, 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth ) Acryloyloxypropyltri n-propoxysilane, 3- (meth) acryloyloxypropyltriiso-propoxysilane, 3- (meth) acryloyloxypropylmethyldichlorosilane and the like.

  When a blocked active hydrogen-containing group, an epoxy group, or a hydrolyzable silyl group is introduced into the active hydrogen group-containing vinyl polymer (b), the amount of these functional groups introduced is the water dispersion of the present invention. 0.05 to 2 mol per 1000 g of the active hydrogen group-containing vinyl polymer (b) from the viewpoint that the water dispersibility of the water-soluble polyisocyanate composition and the curability of the aqueous curable composition of the present invention are good. Preferably, 0.1-1 mol is more preferable.

  Further, in preparing the active hydrogen group-containing vinyl polymer (b), in addition to the various monomers as listed above, other known and conventional monomers copolymerizable with these can be used in combination. . Typical examples thereof include (meth) acrylic acid esters having an alkyl group having 3 or less carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl (meth) acrylate. Various ω-alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate or 4-methoxybutyl (meth) acrylate; a total carbon atom number of 4 or less, such as vinyl acetate and vinyl propionate Carboxylic acid vinyl esters; various crotonic acid esters having an alkyl group having 3 or less carbon atoms, such as methyl crotonate or ethyl crotonate;

Various unsaturated dibasic acid diesters having an alkyl group having 3 or less carbon atoms such as dimethyl malate, dimethyl fumarate and dimethyl itaconate; various cyano groups such as (meth) acrylonitrile and crotononitrile Containing vinyl monomers; various fluoroolefins such as vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene;

Various chlorinated olefins such as vinyl chloride or vinylidene chloride; various α-olefins such as ethylene or propylene; various alkyl groups having 3 or less carbon atoms such as ethyl vinyl ether and n-propyl vinyl ether Alkyl vinyl ethers: tertiary amide group-containing vinyl monomers such as N, N-dimethyl (meth) acrylamide, N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidine or N-vinylpyrrolidone, etc. Is mentioned.

  There is no restriction | limiting in the polymerization method in the case of preparing the above-mentioned active hydrogen group containing vinyl polymer (b), Various well-known and usual polymerization methods are applicable. Among them, the solution radical polymerization method in an organic solvent is particularly convenient and preferable. Then, after preparing the vinyl polymer (b) by the solution radical polymerization method, the solvent is removed, and the reaction with the polyisocyanate (A) is performed to prepare the water-dispersible polyisocyanate of the present invention containing no solvent. I can do things.

  As the polymerization initiator when the solution radical polymerization method is applied, various known and conventional compounds can be used. Typical examples include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylbutyronitrile) or 2,2′-azobis (2-methylbutyronitrile). ) Various azo compounds such as tert-butyl peroxypivalate, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide Alternatively, various peroxides such as diisopropyl peroxycarbonate can be used.

  Moreover, as a solvent for performing solution radical polymerization, various known and commonly used solvents can be used. Representative compounds used as such solvents include aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, n-octane, cyclohexane and cyclopentane; toluene, xylene Aromatic hydrocarbons such as ethylbenzene; various esters such as ethyl acetate, n-butyl acetate, n-amyl acetate, ethylene glycol monomethyl ether acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, Various ketones such as cyclohexanone;

  Polyalkylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether and diethylene glycol dibutyl ether; ethers such as 1,2-dimethoxyethane, tetrahydrofuran and dioxane; ethanol, n-propanol, n-butanol, isobutanol, n -Pentanol, n-hexanol, n-octanol, n-nonanol, isopropanol, sec-butanol, 1-methyl-pentanol, 1-methylhexanol, cyclopentanol, cyclohexanol, t-butanol, t-pentanol, Alkyl alcohols such as 1,1-dimethylbutanol; methoxyethanol, ethoxyethanol, butoxyethanol, methoxypropano , Ethoxy propanol, propoxy propanol, methoxy butanol, methoxy diethylene glycol, butoxy diethylene glycol, Monoarukoshiki (di) alkylene glycol such as methoxy dipropylene glycol; N- methylpyrrolidone, dimethylformamide, dimethylacetamide or ethylene carbonate. Such compounds may be used alone or in combination of two or more.

  The weight average molecular weight of the vinyl polymer (b) prepared as described above is determined by the dispersibility of the polyisocyanate composition of the present invention in water and the isocyanate group water contained in the aqueous dispersion of the composition. From the viewpoints of stability to water and curability of the aqueous curable composition of the present invention, the range is preferably 2,000 to 50,000, more preferably 3,000 to 30,000.

  The weight average molecular weight of the NCO group-containing vinyl polymer (B) is determined by the dispersibility of the water-dispersible polyisocyanate composition of the present invention in water and the stability of the isocyanate groups contained in the aqueous dispersion of the composition with respect to water. From the viewpoint of improving the curability of the aqueous curable composition of the present invention, 2,000 to 50,000 are preferable, and 3,000 to 30,000 are more preferable.

  Next, the method (2), that is, a method of preparing an NCO group-containing vinyl polymer (B) by copolymerizing an isocyanate group-containing vinyl monomer will be described.

  To prepare the NCO group-containing vinyl polymer (B) by the method (2), 1. Polymerize an isocyanate group-containing vinyl monomer and a vinyl monomer containing a hydrophilic monomer-containing vinyl monomer as an essential component. A vinyl polymer containing an isocyanate group obtained by polymerizing a vinyl monomer containing an isocyanate group-containing vinyl monomer as an essential component and a polyoxyalkylene having one end blocked with a group such as an alkoxy group A method of reacting glycol at a molar ratio in which an isocyanate group becomes excessive with respect to a hydroxyl group can be applied. Of these, 1. This method is simple and more preferable.

  Typical examples of the vinyl monomer containing an isocyanate group used in the method (2) include 2-isocyanate propene, 2-isocyanate ethyl vinyl ether, 2-isocyanate ethyl methacrylate, m -Reaction product of isopropenyl-α, α-dimethylbenzyl isocyanate, polyisocyanate and vinyl monomer having a hydroxyl group, and the like.

  In the method (2), as the vinyl monomer containing a hydrophilic group, for example, those used in the method (1) can be used.

  In preparing the NCO group-containing vinyl polymer (B) by the method (2), in addition to the vinyl monomer containing an isocyanate group and the vinyl monomer containing a hydrophilic group, Other monomers copolymerizable with the body can be used in combination. Representative examples of such other copolymerizable monomers include various monomers listed as vinyl monomers copolymerizable in the above method (1). .

In preparing the NCO group-containing vinyl polymer (B), a part or all of the organic solvent is replaced with the hydrophobic polyisocyanate (A), and the mixture of the organic solvent and the hydrophobic polyisocyanate (A) or hydrophobic Polyisocyanate (A) can be used as a solvent.

  The water-dispersible polyisocyanate composition of the present invention is a water-dispersible polyisocyanate composition comprising a hydrophobic polyisocyanate (A) and an NCO group-containing vinyl polymer (B). The isocyanate (A) contains a bifunctional polyisocyanate (A1) containing a uretdione structure and / or an allophanate structure and a trifunctional or higher polyisocyanate (A2), and the bifunctional polyisocyanate (A1) Is 10 to 70% by weight based on the weight of the hydrophobic polyisocyanate (A). The NCO group-containing vinyl polymer (B) contains a bifunctional polyisocyanate (A1) containing a uretdione structure and / or an allohanate structure and a polyisocyanate (A2) having a trifunctional or higher functionality, and the bifunctional The polyisocyanate compound is added so that the content of the polyisocyanate (A1) is 10 to 70% by weight based on the weight of the hydrophobic polyisocyanate (A). A bifunctional polyisocyanate (A1) containing a uretdione structure and / or an allophanate structure as a hydrophobic polyisocyanate (A) and a trifunctional or higher polyisocyanate (A2), and the bifunctional polyisocyanate The content of (A1) is based on the weight of the hydrophobic polyisocyanate (A). The water-dispersible polyisocyanate composition of the present invention can be prepared by using a poly Issy cyanate compound is 10 to 70 wt% Te.

  The ratio of the hydrophobic polyisocyanate (A) and the NCO group-containing vinyl polymer (B) in the water-dispersible polyisocyanate composition of the present invention is not particularly limited, but the ratio of the water-dispersible polyisocyanate composition of the present invention is not particularly limited. Since the dispersibility in water, the stability of the isocyanate group contained in the aqueous dispersion of the composition to water, and the curability of the aqueous curable composition of the present invention are good, (A) / (B) = 30/70 to 90/10 is preferable, 50/50 to 85/15 is more preferable, and 60/40 to 80/20 is most preferable.

  As mentioned above, 1. a method of mixing a previously prepared NCO group-containing vinyl polymer (B) and a hydrophobic polyisocyanate (A); The aqueous dispersion of the present invention is prepared by reacting the active hydrogen group-containing vinyl polymer (b) and the hydrophobic polyisocyanate, preferably in a range where the molar ratio of isocyanate group / active hydrogen-containing group is 10 to 350. A functional polyisocyanate composition is prepared. Among these methods, when the obtained water-dispersible polyisocyanate composition is dispersed in water, the latter method 2. Is preferred.

  Next, the aqueous curable composition containing the water-dispersible polyisocyanate composition of the present invention and the aqueous resin (C) having an active hydrogen-containing group will be described.

  The aqueous resin (C) having an active hydrogen-containing group used in the present invention is not limited as long as it has an active hydrogen-containing group that can react with an isocyanate group. Typical examples of the active hydrogen-containing group contained in the aqueous resin (C) include groups containing an active methylene group such as a hydroxyl group, a carboxyl group, an amino group, an amide group, and an acetoacetyl group. Of these, particularly preferred are a hydroxyl group and a carboxyl group. Examples of the form of the aqueous resin (C) include known and commonly used forms such as an aqueous solution type, an aqueous dispersion type such as a colloidal dispersion and an emulsion.

  Representative examples of the aqueous resin (C) include vinyl acetate resin, styrene-butadiene resin, styrene-acrylonitrile resin, acrylic resin, fluoroolefin resin, silicon-modified vinyl polymer, polyvinyl Vinyl polymers such as alcohol; other than vinyl polymers such as polyester resins, polyurethane resins, phenol resins, melamine resins, epoxy resins, alkyd resins, polyamide resins, polyether resins, silicon resins, etc. Synthetic resins of: natural polymers such as animal protein, starch, cellulose derivatives, dextrin, gum arabic and the like. Of these, preferred are vinyl polymers and various synthetic resins other than vinyl polymers.

  The amount of the active hydrogen-containing group contained in the aqueous resin (C) as described above is based on the solid content of the aqueous resin from the viewpoint of curability of the aqueous curable composition of the present invention and water resistance of the resulting cured product. 0.1 to 6 mol, preferably 0.2 to 4 mol, and most preferably 0.4 to 3 mol. These aqueous resins (C) may be used alone or in combination of two or more.

  A suitable mixing ratio of the water-dispersible polyisocyanate composition of the present invention and the aqueous resin (C) is (1) from the viewpoint of the curability of the curable composition and the performance of the cured product obtained from the composition. The number of moles of isocyanate groups in the polyisocyanate composition, and (2) the active hydrogen-containing group contained in the aqueous resin (C) and the blocked active hydrogen contained in the NCO group-containing vinyl polymer (B) The ratio (1) / (2) to the total number of moles of groups is preferably 0.1 to 5, particularly preferably 0.3 to 3, and most preferably 0.5 to 2.

  The above-described aqueous curable composition of the present invention can be used as a clear composition containing no pigment, or can be used as a colored composition by blending various known organic or inorganic pigments. You can also.

  The aqueous curable composition thus prepared includes paints, adhesives, inks, waterproofing materials, sealants, natural fibers, synthetic fibers, impregnating agents for paper such as glass fibers, natural fibers, synthetic fibers, glass It can be used for various applications such as various fibers such as fibers and surface treatment agents for paper. It is particularly preferable to use it as a water-based paint or a water-based adhesive.

  When used as a water-based paint, such a water-based paint has a long pot life, and further, from the water-based paint of the present invention, a cured coating film having excellent transparency, gloss and other appearance, water resistance, solvent resistance and the like can be obtained. .

  Furthermore, when used as a water-based adhesive, the water-based adhesive has excellent performance such as a long pot life and high adhesive strength.

  In addition, such a composition includes additives suitable for various applications, for example, a filler, a leveling agent, a thickener, an antifoaming agent, an organic solvent, an ultraviolet absorber, an antioxidant, or a pigment dispersion. Various commonly known additives such as an agent can also be blended.

  Next, an aqueous curable composition containing the water-dispersible polyisocyanate composition of the present invention and water will be described.

  The aqueous curable composition of the present invention can be obtained by mixing a water-dispersible polyisocyanate composition and water. In order to obtain such an aqueous curable composition, from the viewpoint of the stability of the isocyanate group of the composition, curability, and the performance of the cured product obtained from the composition, it is based on 100 parts by weight of the polyisocyanate composition. 10 to 1000 parts by weight of water, preferably 50 to 500 parts by weight of water may be added to mix them.

  The aqueous curable composition obtained by mixing the water-dispersible polyisocyanate composition and water can be used as a clear composition containing no pigment, and various known and commonly used organic or inorganic pigments. Can also be used as a coloring composition. Moreover, as needed, various additives etc. which were illustrated as what can be added to the aqueous curable composition obtained from a polyisocyanate composition and aqueous resin (C) can also be mix | blended and used.

  The aqueous curable composition thus prepared can be used for the same applications as the above-mentioned aqueous curable composition, but is particularly preferably used as an aqueous paint or an aqueous adhesive.

  The paint containing this aqueous curable composition has a long pot life and penetrates into a high-density inorganic base material that is difficult to penetrate with a normal aqueous paint to form a cured coating film. Since this coating film has a function of effectively protecting the substrate and also has good adhesion to the top coating film, this coating material can be used as a high-performance undercoating material. Further, the water-based paint is not limited to the undercoat paint, but can be used as an overcoat paint for various substrates.

  When used as a water-based adhesive, it can be used as a water-based adhesive for various applications because it has a long pot life and gives high adhesive strength.

  As the base material to which the aqueous paint of the present invention is applied as described above and the base material to which the aqueous adhesive of the present invention as described above is applied to become an adherend, various known and conventional ones are used. Among them, representative examples include various metal substrates, inorganic substrates, plastic substrates, paper, synthetic fibers, natural fibers, inorganic fibers such as glass fibers, cloth, synthetic leather, natural leather, and wood. Examples thereof include system base materials.

  Among such various substrates, representative examples of metal substrates include metals such as iron, nickel, aluminum, chromium, zinc, tin, copper, and lead; various metals listed above such as stainless steel and brass. Alloys: Various metals or alloys as described above, and various surface-treated metals that have been plated or chemically treated.

  In addition, the inorganic base material is a cured product produced from a calcium compound such as calcium silicate, calcium aluminate, calcium sulfate, or calcium oxide; a ceramic obtained by sintering a metal oxide such as alumina, silica, or zirconia; Tiles obtained by firing various clay minerals; various glasses and the like. Typical examples of hardened bodies produced from calcium compounds include hardened cement compositions such as concrete and mortar, asbestos slate, lightweight cellular concrete (ALC) hardened bodies, dolomite plaster hardened bodies, and gypsum plaster hardened bodies. Body, calcium silicate plate and the like.

  Typical plastic substrates include polystyrene, polycarbonate, polymethylmethacrylate, ABS resin, polyphenylene oxide, polyurethane, polyethylene, polyvinyl chloride, polypropylene, polybutylene terephthalate or polyethylene terephthalate moldings. A molded product of various thermosetting resins such as unsaturated polyester resin, phenol resin, cross-linked polyurethane, cross-linked acrylic resin or cross-linked saturated polyester resin;

In addition, various kinds of base materials as described above, which are pre-coated base materials, or base materials on which the coating is applied, and the deterioration of the coated portion seems to have progressed. A simple substrate can also be used.
These various base materials are used in various shapes such as a plate shape, a spherical shape, a film shape, a sheet shape, a large structure, a complex shape assembly, and the like, depending on applications. There is no.

  Then, the water-based paint of the present invention as described above is applied to the base material as described above by a known and conventional coating method such as brush coating, roller coating, spray coating, dip coating, flow coater coating, roll coater coating. Then, it is allowed to stand at room temperature for about 1 to 10 days, or is heated for about 30 seconds to about 2 hours in a temperature range of about 40 to about 250 ° C., so that it has excellent appearance and water resistance. A coating film can be obtained.

  In addition, the aqueous adhesive of the present invention as described above is applied to at least one of the same types of substrates as described above or different types of substrates by a known and conventional method such as a spatula, a brush, a spray, or a roll. Then, it is allowed to stand at room temperature for about 1 to 10 days, heated at a temperature range of about 40 to about 150 ° C. for about 5 seconds to about 2 hours, or pressurized as necessary. Excellent adhesive strength can be obtained.

  Next, the present invention will be described in detail with reference examples, examples and comparative examples. Unless otherwise indicated, all parts and% in the examples are based on weight. The polyisocyanates used in the examples are as follows.

  The following polyisocyanate (X-1) and polyisocyanate (X-2) were used as the bifunctional hydrophobic polyisocyanate (A1) containing a uretdione structure and / or an allophanate structure.

Difunctional polyisocyanate (X-1)
Allophanate type polyisocyanate obtained from hexamethylene diisocyanate (HDI) and alcohol [Takenate D-178N, manufactured by Mitsui Takeda Chemical Co., Ltd.] As a result of analysis by C13-NMR, the content of allophanate structure is 26% by weight. (Rate 19%, average NCO functional group number 2, nonvolatile content 100%)

Bifunctional polyisocyanate (X-2)
Urethion type polyisocyanate obtained from HDI [Sumitor N3400] manufactured by Sumitomo Bayer Urethane Co., Ltd. As a result of analysis by C13-NMR, the content of uretdione structure is 31% by weight, the content of NCO groups is 22%, and the average number of NCO functional groups is 2, 100% non-volatile content]

  The following polyisocyanate (Y-1) was used as a trifunctional or higher polyisocyanate (A2).

Polyisocyanate (Y-1)
HDI-based isocyanurate type polyisocyanate [Dainippon Ink Chemical Co., Ltd. "Burnock DN-980S" NCO group content 21%, average NCO functional group number 3.6, nonvolatile content 100%]

Reference Example 1 [Preparation of vinyl polymer (b) having active hydrogen group-containing group and hydrophilic group]
A four-necked flask equipped with a stirrer, thermometer, cooling pipe, and nitrogen introduction pipe was charged with 300 parts of n-butanol (hereinafter abbreviated as BUOH) and heated to 110 ° C. under a nitrogen stream. 550 parts of methoxypolyethylene glycol methacrylate (containing 9 average oxyethylene units per molecule, hereinafter abbreviated as “MPEGMA”), 100 parts of methyl methacrylate (hereinafter abbreviated as MMA), 2-hydroxyethyl methacrylate (hereinafter referred to as 2 -A mixture of 60 parts, butyl acrylate (hereinafter abbreviated as BA) 290 parts, 45 parts of t-butylperoxy-2-ethylhexanoate, and 5 parts of t-butylperoxybenzoate. It was dripped over 5 hours. After dropping, the mixture was reacted at 110 ° C. for 5 hours and further distilled under reduced pressure at the same temperature to distill off the decomposition product of BUOH and initiator to obtain an acrylic polymer solution having a nonvolatile content of 98%. Hereinafter, this is abbreviated as a vinyl polymer (b-1).

Reference examples 2 and 3 [same as above]
Polymerization and distillation under reduced pressure were carried out in the same manner as in Reference Example 1 except that the monomers shown in Table 1 (1) were used to obtain an acrylic polymer having a nonvolatile content of 98%. Hereinafter, they are abbreviated as vinyl polymers (b-2) to (b-3).

<< Footnotes in Table 1 >>
Each numerical value indicating the use ratio of the raw materials is part by weight.
"MPEGA-1": [Methoxypolyethylene glycol acrylate (containing 13 average oxyethylene units per molecule)]
“CHMA”: cyclohexyl methacrylate “GMA”: glycidyl methacrylate “SiHEMA”: 2-trimethylsiloxyethyl methacrylate

Example 1 [Preparation of water-dispersible polyisocyanate composition]
A four-necked flask equipped with a stirrer, a thermometer, a cooling tube, and a nitrogen introduction tube was charged with 30 parts of polyisocyanate (X-1), 270 parts of polyisocyanate (Y-1) and vinyl polymer (b-1) 100. The mixture was heated to 90 ° C. under a nitrogen stream and reacted at the same temperature for 6 hours with stirring, and the isocyanate group and vinyl weight in polyisocyanate (X-1) and polyisocyanate (Y-1) were reacted. A water-dispersible polyisocyanate composition (P-1) comprising a hydrophobic polyisocyanate and a vinyl polymer containing a hydrophilic group and an isocyanate group by reacting with a hydroxyl group in the polymer (b-1) Was prepared. In addition, the content rate of polyisocyanate (X-1) in water dispersible polyisocyanate composition (P-1) is 10 weight% on the basis of the weight of hydrophobic polyisocyanate. The non-volatile content in the water-dispersible polyisocyanate composition (P-1) is 100%, and the NCO group content is 16%.

  The water dispersibility of the obtained water dispersible polyisocyanate composition (P-1) and the stability of isocyanate groups contained in the obtained water dispersion were evaluated as follows. The evaluation results are shown in Table 2.

[Evaluation of dispersibility in water]
20 g of a water-dispersible polyisocyanate composition (P-1) was added to a 200 ml beaker containing 80 g of deionized water to obtain a mixture. The mixture was kept at 25 ° C., stirred with a magnetic stirrer and a rotor (full length 30 mm, diameter 8 mm) at a stirring speed of 200 rpm, and the dispersion behavior was visually evaluated according to the following criteria. The shorter the time required for uniform dispersion, the better the water dispersibility.

A: Uniformly dispersed after 3 minutes from the start of stirring. O: Not uniformly dispersed after 3 minutes from the start of stirring, but uniformly dispersed after 5 minutes.
(Triangle | delta): It cannot disperse | distribute uniformly in 5 minutes from the start of stirring, but disperse | distributes uniformly after 10 minutes.
X: Although it cannot disperse | distribute uniformly in 10 minutes from the start of stirring, it disperse | distributes uniformly after 30 minutes.
XX: Even after 30 minutes from the start of stirring, it is not uniformly dispersed.

[Evaluation of residual ratio of isocyanate group]
20 g of a water-dispersible polyisocyanate composition (P-1) was added to a 200 ml beaker containing 80 g of deionized water to obtain a mixture. The mixture was kept at 25 ° C. and stirred for 5 minutes at 2000 rpm using a homodisper to prepare an aqueous dispersion of the water-dispersible polyisocyanate composition (P-1). Immediately after the preparation of the aqueous dispersion, excess dibutylamine was added, and then the isocyanate group content in the aqueous dispersion was determined by a back titration method in which dibutylamine remaining with an aqueous hydrochloric acid solution was titrated. Further, after 6 hours from the preparation of the aqueous dispersion, the isocyanate group content was measured by a back titration method, and the isocyanate group residual rate was determined from the two isocyanate group contents according to the following formula. It shows that stability of an isocyanate group is so favorable that this value is large.

  Isocyanate group residual ratio [%] = (Isocyanate group content after 6 hours / Isocyanate group content immediately after dispersion) × 100

Examples 2 to 7 (same as above)
Water-dispersible polyisocyanate compositions (P-2) to (P-7) were prepared in the same manner as in Example 1 except that the blending amounts shown in Table 2 (1) and Table 2 (2) were used. did. In the same manner as in Example 1, water dispersibility and isocyanate group residual ratio were evaluated, and the results are shown in Table 2 (1) and Table 2 (2).

Comparative Example 1 [Preparation of Polyisocyanate Composition (RP-1) for Comparative Example]
In a reactor similar to that of Reference Example 1, 250 parts of methoxypolyethylene glycol (containing 9 average oxyethylene units per molecule, hereinafter abbreviated as “MPEG-1”) and 1000 parts of hydrophobic polyisocyanate (Y-1) were added. The resulting mixture was heated to 90 ° C. over 30 minutes and then reacted at 90 ° C. for 6 hours to obtain a polyisocyanate modified with methoxypolyethylene glycol having a nonvolatile content of 100% and an NCO group content of 16%. Hereinafter, this is abbreviated as a polyisocyanate composition (RP-1). In the same manner as in Example 1, the evaluation of the dispersibility in water and the evaluation of the residual ratio of isocyanate groups were carried out, and the results are shown in Table 2 (3).

Comparative Example 2 (same as above)
In the same reactor as in Reference Example 1, 100 parts of methyl ricinoleate, 1000 parts of hydrophobic polyisocyanate (Y-1) and 150 parts of MPEG-1 were charged, heated to 80 ° C., and stirred for 3 hours under a nitrogen stream. After mixing, 11 parts of poly (oxyethylene) nonylphenyl ether acrylate ester (molecular weight of about 1000) and 2.2 parts of 2,2′-azobis-2-isobutyronitrile were further charged at 90 ° C. A polyisocyanate composition for comparison and control comprising a polyisocyanate modified with methoxypolyethylene glycol having a nonvolatile content of 100% and an NCO group content of 13% and an isocyanate group-containing vinyl polymer was obtained by reacting for 6 hours. Hereinafter, this is abbreviated as a polyisocyanate composition (RP-2). In the same manner as in Example 1, the evaluation of the dispersibility in water and the evaluation of the residual ratio of isocyanate groups were carried out, and the results are shown in Table 2 (3).

Comparative Example 3 (same as above)
In the same reactor as in Reference Example 1, 35 parts of hydrophobic polyisocyanate (Y-1), 15 parts of methoxypolyethylene glycol (containing 22 average oxyethylene units per molecule) and 67 parts of propylene glycol monomethyl ether acetate were charged. The temperature was raised to 110 ° C., and the mixture was stirred and mixed for 3 hours under a nitrogen stream. After adding 0.5 parts of p-toluenesulfonyl isocyanate, the temperature was raised to 130 ° C., 5 parts of styrene, 5 parts of MMA, 10 parts of BA, 15 parts of 3-isopropenyl-α, α-dimethylbenzyl isocyanate, methoxypolyethylene glycol methacrylate ( A mixture comprising 15 parts of an average of 22 oxyethylene units per molecule), 0.25 part of α-methylstyrene dimer and 1.5 parts of t-butylperoxyisopropyl carbonate was added dropwise over 3 hours.

  After completion of dropping, the reaction was carried out at 130 ° C. for 3 hours to obtain a comparative polyisocyanate composition having an NCO group content of 6.0%. Hereinafter, this is abbreviated as a polyisocyanate composition (RP-3). In the same manner as in Example 1, the evaluation of the dispersibility in water and the evaluation of the residual ratio of isocyanate groups were carried out, and the results are shown in Table 2 (3).

Comparative Examples 4 and 5 (same as above)
Comparative water-dispersible polyisocyanate compositions for comparison (RP-4) and (RP-5) were prepared in the same manner as in Example 1 except that the blending amounts shown in Table 2 (3) and (4) were used. did. In addition, the content rate of each bifunctional polyisocyanate (X-1) in water dispersible polyisocyanate composition (RP-4) and (RP-5) is 7 respectively on the basis of the weight of hydrophobic polyisocyanate. %, 75%. In the same manner as in Example 1, water dispersibility and isocyanate group residual ratio were evaluated, and the results are shown in Tables (2) and (4).

Active hydrogen group-containing aqueous resin (C-1)
A hydroxyl group-containing acrylic resin emulsion “WE-303” (Dainippon Ink Co., Ltd.) having a nonvolatile content of 45% and a solid content hydroxyl value of 84 mgKOH / g is abbreviated as an aqueous resin (C-1).

Example 8
109 parts of the polyisocyanate composition (P-1) obtained in Example 1 and an aqueous resin (C) so that the molar ratio of isocyanate group / hydroxyl group in the aqueous resin (C-1) is 1.2 / 1. 500 parts of -1) and 55 parts of ion-exchanged water were added and sufficiently stirred and mixed to prepare an aqueous curable composition. Hereinafter, this is abbreviated as an aqueous curable composition (D-1). The obtained aqueous curable composition (D-1) was applied onto a glass plate and a polypropylene plate (hereinafter abbreviated as PP plate) using an applicator so that the dry coating film was 60 μm immediately after preparation, The film was dried for 2 weeks under conditions of a temperature of 25 ° C. and a humidity of 50% RH to prepare a cured coating film. About the obtained cured coating film, compatibility, gel fraction, and water resistance were evaluated according to the following evaluation methods. The evaluation results are shown in Table 3 (1).

[Compatibility evaluation]
The transparency of the coating film prepared on the glass plate was evaluated according to the following criteria.
A: No turbidity at all.
○: Slightly cloudy.
Δ: There is considerable turbidity.
X: Remarkably turbid.

[Evaluation of gel fraction]
The coating film prepared on the PP plate was cut from the PP plate, immersed in acetone at 25 ° C. for 24 hours, and then dried at 100 ° C. for 90 minutes. Thereafter, the gel fraction was calculated by the following formula. The gel fraction is an evaluation of the curability of the aqueous curable composition, and the higher the value, the better the curability.

  Gel fraction [%] = (weight of coating film after immersion in acetone / weight of coating film before immersion in acetone) × 100

[Evaluation of water resistance]
The coating film prepared on the glass plate was immersed in ion-exchanged water at 25 ° C. for 24 hours, and the appearance of the coating film was evaluated for whitening and swelling of the coating film. The evaluation criteria at that time are as follows.

Evaluation standard for coating whitening.
A: No change at all.
○: Very slight whitening.
Δ: Fairly whitened.
X: Remarkably whitened.

Criteria for coating swelling: A: No change at all.
○: Slightly swollen.
Δ: Swelling occurs considerably.
X: Remarkably swollen.

Examples 9-15
Aqueous curable compositions (D-2) to (D-8) were prepared in the same manner as in Example 8 except that the formulation shown in Table 3 was used. Further, as water-based resin (C-2), “Watersol ACD-2000” [Dai Nippon Ink Chemical Co., Ltd. acrylic resin-containing acrylic resin-containing aqueous dispersion, nonvolatile content 35%, solid content hydroxyl value 50 mgKOH / g] was used. Evaluation was performed in the same manner as in Example 8, and the results are shown in Table 3 (1) and Table 3 (2).

Examples 16 and 17
D-1 and D-2 prepared above are allowed to stand for 6 hours under the conditions of a temperature of 25 ° C. and a humidity of 50% RH (abbreviated as D-1 ′ and D-2 ′, respectively), and the dry coating film becomes 60 μm. Thus, it apply | coated on the glass plate using the applicator and dried for 2 weeks on the conditions of temperature 25 degreeC and humidity 50% RH, and the cured coating film was created. About these, evaluation similar to Example 8 was performed. The evaluation results are shown in Table 3 (3).

Comparative Examples 6-10
500 parts of (C-1) or (C-2) are used as the aqueous resin (C), and the molar ratio of isocyanate group / hydroxyl group in the aqueous resin (C-1) or (C-2) is 1.2. The curable compositions (RD-1) to (RD-5) for comparative evaluation were prepared by mixing the polyisocyanate compositions and ion-exchanged water in the amounts shown in Table 3 so as to be 1/1. . In the same manner as in Example 8, a cured coating film was prepared by coating and drying on a glass plate and a PP plate immediately after preparation. About these, evaluation similar to Example 8 was performed. The evaluation results are shown in Table 3 (4) and Table 3 (5).

Comparative Example 11
RD-1 ′ was prepared in the same manner as in Example 16 except that RD-1 was used. Using this, it apply | coated on the glass plate using the applicator so that a dry coating film might be set to 60 micrometers, and it dried for 2 weeks on the conditions of temperature 25 degreeC and humidity 50% RH, and created the cured coating film. About these, evaluation similar to Example 8 was performed. The evaluation results are shown in Table 3 (5).

Reference Example 4 (Preparation of main component of paint)
88 parts of deionized water, “Disperbyk-190” (pigment dispersant manufactured by BYK Co., Ltd.) 23.3 parts, BYK-011 [antifoaming agent manufactured by BYK Co., Ltd.] 1.8 parts, “Ti -Pure R-960 "[Titanium oxide manufactured by Du-Pont Co., Ltd.] and a mixture of 1.4 parts of a 10 wt% aqueous solution of diethanolamine were dispersed with a disper for 1 hour. The aqueous resin (C-1) 570. Part, BYK-346 [leveling agent manufactured by BYK Co., Ltd.] 3.9 parts, dynol 604 [leveling agent manufactured by Air Products Co., Ltd.] 3.9 parts, Primal RM-8W [Rohm & Haas Co., Ltd. 4.8 parts by weight of a 10% by weight aqueous solution) and 19.3 parts of a 10% by weight aqueous solution of SN deformer 373 [an antifoaming agent by San Nopco Co., Ltd.] Titanium) A white paint main ingredient component having a weight concentration of 50% and a nonvolatile content of 55% was obtained. This is abbreviated as paint main component (E-1).

Example 18 (Preparation of water-based paint)
In the ratio described in Table 4, the polyisocyanate composition, the paint main component and water were mixed to prepare a white aqueous paint having a nonvolatile content of 52%. This is abbreviated as water-based paint (F-1). In addition, it mix | blended so that the molar ratio of the isocyanate group in water-based paint (F-1) / hydroxyl group in water-based resin (C-1) might be set to 1.5 / 1.

  Immediately after preparation of the water-based paint (F-1), a coating film was formed on the glass plate by an air spray method so that the dry film thickness was 70 μm. Subsequently, it dried for 2 weeks in the atmosphere of temperature 25 degreeC and humidity 50% RH, and the cured coating film was obtained. The obtained cured coating film was evaluated for gloss and water resistance according to the following methods. The evaluation results are shown in Table 4 (1).

[Evaluation of gloss]
The 60 degree specular reflectance [%] of the cured coating film was measured, and this value was used as the gloss evaluation value. The higher the value of the 60-degree specular reflectance, the higher the gloss and the better the appearance.

[Evaluation of water resistance]
The glass plate on which the cured coating film was formed was immersed in ion-exchanged water at 25 ° C. for 24 hours, and the gloss retention of the coating film and the state of swelling of the coating film were observed and evaluated according to the following criteria.

Gloss retention [%] = (Gloss value after immersion in ion-exchange water / Gloss value before immersion in ion-exchange water) × 100
* The gloss value is the value of the 60-degree specular reflectance [%] of the coating film.

Criteria for coating swelling: A: No change at all.
○: Slightly swollen.
Δ: Swelling occurs considerably.
X: Remarkably swollen.

Examples 19-21 and Comparative Examples 12-16
Aqueous paints F-2 to F-4 and comparative aqueous paints RF-1 to RF- in the same manner as in Example 18 except that the formulations shown in Table 4 (1) and Table 4 (2) were used. 5 was prepared. In the same manner as in Example 18, the gloss retention of the coating film and the state of swelling of the coating film were evaluated. In all Examples and Comparative Examples, the mixing was performed so that the molar ratio of isocyanate group / hydroxyl group in the aqueous resin (C-1) was 1.5 / 1. The evaluation results are shown in Table 4 (1) to Table 4 (3).

Example 22
A water-based paint was prepared by mixing 350 parts of a water-dispersible polyisocyanate composition (P-1), 750 parts of ion-exchanged water, and 0.2 part of BYK-028 [defoamer manufactured by BYK Co., Ltd.]. Hereinafter, this is abbreviated as water-based paint (G-1). A coating film was formed on a calcium plate by an air spray method so that the obtained water-based paint (G-1) had a dry film thickness of 30 μm immediately after preparation. Subsequently, it was dried for 2 weeks under the conditions of a temperature of 25 ° C. and a humidity of 50% RH. About the obtained cured coating film, adhesiveness was evaluated in accordance with the following evaluation criteria. The results are shown as adhesiveness (1) in Table 5 (1).

[Evaluation method for adhesion (1)]
Using a cutter knife, cuts at intervals of 2 mm were made vertically and horizontally so that 25 2 mm square grids could be formed on the coating film prepared on the calcium plate. Subsequently, the adhesive tape was peeled off after being brought into close contact with the grid, and evaluated by the residual ratio, which is the ratio of the coating film remaining on the calcium plate. The residual rate was calculated by the following formula.

Residual rate of coating film [%] = (Area of coating film remaining after peeling / Area of coating film on grid before peeling) × 100
It shows that it is a water-based paint which is excellent in adhesiveness with a calcium plate, so that the residual rate [%] of a coating film is high.

  Also, immediately after preparation of the water-based paint (G-1), a coating film is formed on the slate plate by an air spray method so that the dry film thickness becomes 30 μm, and is dried for 24 hours under conditions of a temperature of 25 ° C. and a humidity of 50% RH. An undercoat coating film was obtained. Thereafter, the water-based paint (F-2) obtained in Example 19 was applied as an overcoating by an air spray method so that the dry film thickness was 60 μm immediately after preparation. Then, it was dried for 1 week under conditions of a temperature of 25 ° C. and a humidity of 50% RH. The adhesiveness of the multilayer cured coating film thus obtained was evaluated. The results are shown as adhesiveness (2) in Table 5 (1).

  The same operation as that for the adhesive property (1) was performed, and the evaluation was made with the residual ratio, which is the ratio of the coating film remaining on the slate plate. For this multi-layer coating film, there are both cases where only the coating film of the top coat peels off and cases where the coating film peels off from the undercoat coating film. The residual rate was calculated in the same manner as in the case of “Adhesion (1)”. The higher the remaining rate [%] of the coating film, the better the adhesion with the calcium plate and the adhesion with the top coating, indicating that the aqueous coating strongly bonds the calcium plate and the top coating.

Examples 23 to 25 and Comparative Examples 17 to 19
Example 22 except that 350 parts of various polyisocyanate compositions shown in Table 5 (1) and Table 5 (2) were used instead of 350 parts of the polyisocyanate composition (P-1). In the same manner, aqueous paints G-2 to G-4 and comparative aqueous paints RG-1 to RG-3 were prepared. A cured coating film was prepared in the same manner as in Example 22, and the adhesion of this cured coating film was evaluated. The evaluation results are shown in Table 5 (1) and Table 5 (2).

Aqueous resin (C-3)
"HYDRAN HW-311" [Dai Nippon Ink Chemical Co., Ltd. polyester-based urethane resin aqueous dispersion, non-volatile content 45%]

Example 26 (Preparation of aqueous adhesive)
95 parts of an aqueous resin (C-3) and 5 parts of a water-dispersible polyisocyanate composition (P-1) were mixed and stirred to obtain an aqueous adhesive (H-1). The aqueous adhesive (H-1) immediately after blending was applied to a 2 mm thick plywood (JAS type II) by spraying at a rate of 80 g / m 2 and dried at 50 ° C. for 5 minutes. To this, a vinyl chloride sheet having a thickness of 2 mm was laminated and hot-pressed for 1 minute at 50 ° C. and 0.01 MPa. Subsequently, it was dried for 1 week under the conditions of a temperature of 20 ° C. and a humidity of 60% RH. Thus, the adhesive evaluation in 60 degreeC was performed about the joining board of the obtained plywood and the vinyl chloride sheet. The evaluation results are shown in the columns of “Adhesive evaluation (I)” and “Adhesive evaluation (II)” in Table 6 (1). The evaluation method is shown below.

<Adhesion evaluation (I)>
A test piece was prepared by cutting a joining plate of a plywood and a vinyl chloride sheet into a width of 25 mm. The plywood was fixed in a constant temperature bath at 60 ° C., a load of 500 g was applied to the vinyl chloride sheet, and after standing for 15 minutes, the peel length (mm) of 180 degrees was measured. It shows that adhesiveness is so good that this value is small.

Examples 27-29, Comparative Examples 20-22
Instead of 5 parts of polyisocyanate composition (P-1), aqueous adhesive (H-2) was used in the same manner as in Example 26 except that 5 parts of various polyisocyanate compositions shown in Table 7 were used. To (H-4) and (K-5) to (K-7) were obtained. A joined plate of a plywood and a vinyl chloride sheet was prepared in the same manner as in Example 26 except that each aqueous adhesive thus obtained was used in place of the aqueous adhesive (H-1). About these, the adhesive evaluation in 60 degreeC was performed. The evaluation results are shown in the column of “Adhesion Evaluation (I)” in Table 6 (1) and Table 6 (2).

<Change with time of adhesiveness after preparation of adhesive>
The aqueous adhesives obtained in Examples 26 to 29 and Comparative Examples 20 to 22 were allowed to stand for 3 hours under the conditions of a temperature of 20 ° C. and a humidity of 60% RH. Similarly, a joint plate was prepared, and the evaluation of adhesion at 60 ° C. was performed in accordance with the above “Adhesion Evaluation (I)”, and the evaluation results are shown in “Adhesion Evaluation (II)” in Table 6. Shown in the column. It was found that even when the adhesives prepared in Examples 26 to 29 were used after 3 hours had elapsed after preparation, the decrease in adhesive strength was extremely small, and the aqueous adhesive of the present invention had a long pot life.

Claims (11)

A water-dispersible polyisocyanate composition comprising a hydrophobic polyisocyanate (A) and a vinyl polymer (B) containing a hydrophilic group and an isocyanate group, wherein the hydrophobic polyisocyanate (A) is: It contains a bifunctional polyisocyanate (A1) containing a uretdione structure and / or an allohanate structure and a trifunctional or higher polyisocyanate (A2), and the content of the bifunctional polyisocyanate (A1) is hydrophobic. A water-dispersible polyisocyanate composition which is a polyisocyanate which is 10 to 70% by weight based on the weight of the polyisocyanate (A). The water-dispersible polyisocyanate composition according to claim 1, wherein the bifunctional polyisocyanate (A1) is an aliphatic bifunctional isocyanate containing an allophanate structure. The water-dispersible polyisocyanate composition according to claim 1, wherein the content of the bifunctional polyisocyanate (A1) is 20 to 60% by weight based on the weight of the hydrophobic isocyanate (A). The water-dispersible polyisocyanate composition according to claim 1, wherein the hydrophilic group in the vinyl polymer (B) is a polyoxyalkylene group whose end is blocked with an alkoxy group. The water-dispersible polyisocyanate composition according to claim 1, wherein the vinyl polymer (B) is a vinyl polymer further containing a hydrophobic group having 4 or more total carbon atoms. The water-dispersible polyisocyanate composition according to claim 1, wherein the vinyl polymer (B) is a vinyl polymer further containing a blocked active hydrogen-containing group and / or an epoxy group. The water dispersion according to claim 1, wherein the mixing ratio [(A) / (B)] of the hydrophobic polyisocyanate (A) and the vinyl polymer (B) is 30/70 to 85/15 by weight. Polyisocyanate composition. An aqueous curable composition comprising the water-dispersible polyisocyanate composition according to claim 1 and an aqueous resin (C) having an active hydrogen-containing group that reacts with an isocyanate group. . An aqueous curable composition comprising the water-dispersible polyisocyanate composition according to any one of claims 1 to 7 and water. A water-based paint comprising the water-based curable composition according to claim 8 or 9. An aqueous adhesive comprising the aqueous curable composition according to claim 8 or 9.