WO2006104111A1 - Modified water-based resin composition - Google Patents

Abstract

[PROBLEMS] To provide a polyisocyanate-curable water-based dispersion coating material (such as water-based polyurethane resin composition) which is improved in the dispersibility of the chief material resin in an aqueous medium and prolonged in the pot life by depressing the reaction of water with isocyanate group (which is highly reactive with water) and which can form a coating film exhibiting excellent surface appearance and water resistance equivalent to those of films of conventional solvent-type polyurethane resin coating materials in spite of its being a water-based coating film. [MEANS FOR SOLVING PROBLEMS] A water-based resin composition comprising (A) a water-based acrylic resin or a water-based polyurethane resin obtained by reacting a diisocyanate with a polyol and (B) a polyisocyanate dispersible in the component (A), characterized by containing (C) a low-molecular-weight compound having a carbon-carbon unsaturated bond and a carbonyl group adjacent thereto.

Description

 Specification

 Modified aqueous resin composition

 Technical field

 [0001] The present invention relates to an aqueous resin composition, and more specifically, a modified aqueous resin composition that has been modified with a specific additive compound, the pot life of the composition is extended, and the aqueous medium dispersibility is improved. In particular, the present invention relates to a polyurethane resin composition, a method for producing the same, and use of the composition as a coating agent for paints and the like.

 Background art

 [0002] Due to its excellent physical properties and economics, polyurethane resin compositions are widely used and used as coating agents for paints and the like mainly in many fields mainly for building materials and vehicles. In order to deal with environmental problems, workability, or to reduce costs, avoid using organic solvent-based coatings, especially volatile organic solvent-based coating agents, and make organic solvents water-based or change to aqueous media. In addition, a shift to a coating agent of an aqueous polyurethane resin composition using an aqueous dispersion medium has been requested and is universally performed. In addition, not only the polyurethane resin composition but also other resin compositions such as an acrylic resin cured with polyisocyanate have the same problem, and a shift to an aqueous resin composition has been performed.

 In a water-based (aqueous) resin composition, as a basic problem, the dispersibility or solubility of the resin base in an aqueous medium is improved, and the reactivity with water in an isocyanate group that is highly reactive with water is increased. It is essential to suppress it.

[0003] In order to deal with such problems, a great number of various methods have been developed and disclosed in patent publications.

Among the aqueous resin compositions, the aqueous polyurethane resin composition has previously proposed a composition in which an isocyanate group is blocked with a polyoxyalkylene glycol or the like in order to increase moisture dispersibility. The reactivity with water is not suppressed, the isocyanate group is consumed quickly by water, the usable time of the composition as a paint is short, and the film has poor hardness and water resistance. Met. Later, a method for improving the water dispersibility by modifying the isocyanate group with a hydrophilic surfactant or an aliphatic compound having active hydrogen was disclosed (Patent Document 1), but the stability of the isocyanate group to water was disclosed. However, dispersibility in water is not sufficient, and a composition obtained by mixing a nonionic hydrophilic group-containing compound with a hydrophilic polyisocyanate and an ionic surfactant is also available. Although disclosed (Patent Document 2), the stability of the isocyanate group in water and the dispersibility in water are not sufficient, and mixing of the ionic emulsifier adversely affects the coating film.

[0004] Furthermore, a composition (Patent Document 3) that is obtained by partially urethanizing an isocyanate group with an alcohol to increase the usable time as a paint and also cure at room temperature, and a hydroxyl group-containing polyester containing a carboxylate or a sulfonate group. A composition that provides a long pot life and quick-drying by use (Patent Document 4), and a non-blocked diisocyanate curing agent finely dispersed in the dispersion liquid improves the pot life and improves the processing time. By using a paint that does not generate carbon dioxide (Patent Document 5), a polyisocyanate bound to a phosphine compound neutralized with a polyol with a specified hydroxyl value and a base, it has excellent water dispersibility and is free of isocyanate groups. A composition that improves the dispersibility in water and the pot life by using a composition in which reactivity with water is suppressed (Patent Document 6) and a polyurethane resin having a nonionic group in the side chain. (Patent Document 7) and other proposals to improve the pot life by increasing the dispersibility of polyurethane resins in aqueous media and suppressing the reactivity of isocyanate groups with water by various means. There are many things.

 However, none of these proposals have sufficiently improved both the dispersibility in water and the pot life in the aqueous polyurethane resin composition, and the main problems in the aqueous polyurethane resin composition The water dispersibility and the pot life are both sufficiently improved, and the coating appearance is not deteriorated due to the generation of carbon dioxide during coating. Excellent water-based polyurethane resin composition has not yet been obtained. In the case of aqueous acrylic resin compositions, it can be said that the situation is the same based on conventional patent literature.

 [0006] Patent Document 1: Japanese Patent Laid-Open No. 7-113005 (Abstract)

Patent Document 2: JP-A-9-71720 (Abstract) Patent Document 3: Japanese Patent Application Laid-Open No. 7-109327 (Abstract)

 Patent Document 4: Japanese Patent Laid-Open No. 9157585 (Abstract, Claim 1) Patent Document 5: Japanese Patent Laid-Open No. 10-140084 (Abstract)

 Patent Document 6: Japanese Patent Laid-Open No. 10-306255 (Abstract)

 Patent Document 7: Japanese Unexamined Patent Publication No. 2003-64149 (Abstract)

 Disclosure of the invention

 Problems to be solved by the invention

[0007] As described in paragraphs 0002 to 0005, in an isocyanate curable aqueous resin composition such as an aqueous polyurethane resin composition generally used mainly as an aqueous polyurethane resin coating agent, a resin is used. The ability to extend the pot life by increasing the dispersibility of the main agent in an aqueous medium, extremely high reactivity with water, and suppressing the reactivity of the isocyanate group with water. Therefore, the present invention solves this problem as much as possible, and at the same time, in an aqueous coating film, it is not inferior to conventional organic solvent-based polyurethane resin coating agents, and has excellent film appearance, hardness, water resistance, etc. Also get

The present invention is to solve the problems.

 Means for solving the problem

[0008] The inventors of the present invention aim to solve the above-mentioned problems, and the dispersibility of the resin main agent in an aqueous medium, such as an aqueous polyurethane resin composition or an aqueous acrylic resin composition. In order to increase the sensitivities, from a viewpoint different from the conventional method, the dispersion method of the main agent of the composition and the curing agent or the use of a dispersion aid, etc., and to suppress the reactivity of the isocyanate group with water, The method of modification of the isocyanate group or the use of additives for modification, etc. was investigated in a multifaceted manner seeking new methods, and trial experiments were continued, and in the process, the isocyanate group was exchanged with water. It is possible to find a modifier as an additive that can suppress the reactivity and extend the usable time of the aqueous resin composition, and the action of the modifier improves the aqueous resin composition. Dispersibility of products in aqueous media Also able to recognize that it is possible to improve, it has been in that newly created the present invention based on the duality of features.

[0009] In the present invention, by the chemical action of a specific modifying additive, It is possible to sufficiently extend the pot life of the aqueous resin composition by suppressing the reactivity with water, and at the same time, the dispersibility of the aqueous resin composition in the aqueous medium by the action of the modifier. Can be sufficiently improved, thereby reducing the viscosity of the resin composition and improving the workability as a coating agent. Furthermore, it has an excellent film appearance and hardness comparable to conventional organic solvent-based polyurethane resin coating agents. In addition, a film having water resistance and the like can be obtained.

 [0010] An additive for the modification in an aqueous polyurethane resin composition or the like is a low molecular weight having an intercarbon unsaturated bond and an adjacent carbonyl group used in a specific aqueous resin composition. A compound.

 The specific aqueous polyurethane resin composition is an aqueous polyurethane resin obtained by reacting a diisocyanate compound with a diol compound (polyol compound) as component (A), and (A) as component (A) ) A resin composition containing a polyisocyanate compound dispersible in the component. Specifically, as the component (A), a polyester polyol or an aliphatic diisocyanate compound is used. Aqueous polyurethane prepolymers that have been reacted with polyether polyols IJ, (B) Contains a curing agent that is a trimer or adduct of a diisocyanate compound that can be dispersed in component (A). A low molecular weight compound having a carbon-carbon unsaturated bond and an adjacent force group is a coating composition, such as an unsaturated dicarboxylic acid diester that is added to the coating composition as component (C). is there.

[0011] In addition, the combination of the polyisocyanate of component (B) and the low molecular weight compound having an unsaturated bond between carbons of component (C) and an adjacent carbonyl group in the present invention is an aqueous polyurethane resin composition. Not limited to this, it can also be used as a curing agent for an aqueous resin composition such as an aqueous acrylic resin, and the same working effects as in the aqueous polyurethane resin composition can be obtained.

 In the following, the aqueous polyurethane resin composition in the aqueous resin composition will be mainly described.

[0012] More specifically, as a preferred embodiment, the curing agent of component (B) is an allophanate curing agent of hexamethylene diisocyanate having 4 or more functional groups, and (C) a modifying additive of component (C) Is a maleic acid dialkyl ester, and the coating composition is mainly a paint composition, which is exclusively a two-component paint composition comprising (A) an aqueous polyurethane resin and (B) This is a two-component composite material of polyisocyanate as a curing agent for components. When used as a paint, the two components are mixed, and the additive of component (C) is added in advance as component (A) or (B). It is added to the components or added when mixing the components (A) and (B).

[0013] In addition, as a typical production method of the aqueous resin composition of the present invention, a curing agent (B), a low molecular weight compound (C), and, if necessary, a dispersion aid are dispersed in an aqueous medium. The aqueous dispersion is combined with the resin main component of component (A) to form a composition thereof.

 [0014] By the way, even if the prior art (each patent document) described in paragraphs 0003 to 0005 or the prior art of the isocyanate-based aqueous acrylic resin composition is scrutinized, the present invention summarized in paragraphs 0009 to 001 0 is described. However, the constitution and characteristics of the modifier used in the specific water-based polyurethane resin composition or water-based acrylic resin composition of the present invention, and the aqueous The pot life of the resin composition can be sufficiently extended, the dispersibility in an aqueous medium can be sufficiently improved, and an excellent film that is not inferior to conventional organic solvent-based polyurethane resin coating agents can be obtained. The effect which can be said is novel as a water-based resin composition, and can be said to be remarkable.

 [0015] The present invention, which has been created as described above and has distinctive features, will be clearly described in a bird's-eye view as a whole. The present invention comprises the following invention unit groups, The invention of [1] is used as a basic invention, and the inventions below it embody or implement the basic invention. (The entire invention group is collectively referred to as “the present invention”.)

 [1] A resin composition containing a water-dispersible resin main component as component (A), a polyisocyanate H compound dispersible in component (A) as component (B), and component (C) As a water-based resin composition, a low molecular weight compound having an unsaturated bond between carbons and an adjacent carbonyl group is added.

[2] As the component (A), an aqueous acrylic resin main component or an aqueous polyurethane prepolymer base obtained by reacting a polyol with a diisocyanate compound, and as a component (B), a didispersible component in the component (A). It contains a curing agent that is a trimer or adduct of an isocyanate compound, the component (C) is a low molecular weight compound having a number average molecular weight of less than 500, and the component mass ratio of (B) / (A) is 0.01 to 0.50, and component (C) is 0.01 to 30 with respect to 100 parts by mass of component (B). The aqueous resin composition according to [1], wherein the resin composition is a coating composition added in an amount of parts by mass.

 [3] The (B) component curing agent is an allophanate curing agent of hexamethylene diisocyanate having 4 or more functional groups, and (C) component is an unsaturated dicarboxylic acid diester. The aqueous polyurethane resin composition in 2].

 [4] The aqueous polyurethane resin composition according to [3], wherein the unsaturated dicarboxylic acid diester is a maleic acid dialkyl ester.

 [5] The aqueous polyurethane resin composition according to [2] to [4], wherein the coating composition is a coating composition.

 [6] The aqueous polyurethane resin composition is a two-component coating composition, and is a two-component composition material of (A) an aqueous polyurethane resin and (B) a polyisocyanate as a curing agent. When used as a paint, the two components are mixed, and the additive of component (C) is added in advance to component (A) or (B), or added when mixing component (A) and component (B) The water-based polyurethane resin composition according to [5], wherein

 [7] Composition of (B) component curing agent, (C) component low molecular weight compound and, if necessary, a dispersion aid dispersed in an aqueous medium as an aqueous dispersion, and (A) component water-dispersible resin main component The method for producing an aqueous resin composition according to [1] or [2], wherein

 The invention's effect

 [0017] In the present invention, the pot life of the isocyanate curable aqueous resin composition can be sufficiently extended, and the dispersibility of the aqueous resin composition in an aqueous medium can be sufficiently improved. As a result, the resin composition becomes uniform, the viscosity of the resin composition is reduced, the workability as a coating agent is improved, and an excellent film appearance, which is not inferior to conventional organic solvent-based polyurethane resin coating agents, A film having hardness and water resistance can be obtained.

 BEST MODE FOR CARRYING OUT THE INVENTION

[0018] The present invention has been described in accordance with the basic configuration of the present invention as a means for solving the problem, but in the following, the embodiment of the invention of the present invention group will be mainly described. The aqueous polyurethane resin composition will be specifically described in detail. [0019] 1. Aqueous resin composition

 (1) Basic composition of the composition

 The aqueous resin composition of the present invention basically comprises an aqueous polyurethane resin (prepolymer) obtained by reacting an aqueous acrylic resin or diisocyanate compound with a polyol compound as component (A). ), A resin composition containing a polyisocyanate compound dispersible in component (A) (its aqueous dispersion) as component (B) and using water as a medium, and detailed in paragraphs 0027 to 0030 (C) ) Component is added.

 In this composition, the component mass specific force of (B) Z (A), preferably 0.01-0.50. When the amount is less than this range, there are too few crosslinking points, and good physical properties cannot be obtained. When the amount is too large, the composition is remarkably thickened and the appearance of the coating film is deteriorated. In addition, the pot life is shortened, which is not preferable.

[0020] (2) Diisocyanate compound

 As the diisocyanate component used in the present invention, an organic diisocyanate compound is used, and a usual one as a raw material of a polyurethane resin is used. In order to avoid yellowing of the coating film due to ultraviolet rays, aliphatic or alicyclic diisocyanates are preferred over aromatic diisocyanates. (Hereinafter, specific examples of compounds that are not related to the essence of the invention are only briefly described.)

 Specific examples of the aliphatic diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 2-methyl-pentane 1,5-diisocyanate, and 3-methyl monopentane. Examples include 1,5 diisocyanate, 2,2,4-trimethyl-hexane—, L 6-diisocyanate, and the like. Alicyclic diisocyanates include cyclohexylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane. Examples include diisocyanate and hydrogenated trimethylxylylene diisocyanate.

These diisocyanates are used alone or as a mixture of two or more if necessary. [0021] (3) Polyol compound

 As the polyol component (diol, triol, etc.) used in the present invention, polyester polyol or polyether polyol is mainly used, and polycarbonate polyol, acrylic polyol, and polyolefin polyol can also be used. For these, ordinary materials used as raw materials for polyurethane resins are used, and there are no particular restrictions.

 Representative examples include polypropylene ethylene polyol (PPG), polytetramethylene ether glycol (PTG), polytetramethylene glycol (PTMG), and the like.

[0022] More specifically, examples of the polyester polyol include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, malonic acid, adipic acid, 1,4-cyclohexylenoresicarboxylic acid, maleic acid. , Fumaric acid, other dibasic acids, etc., ethylene glycol, 1,2_propanediol, 1,3_propanediol, 1,2_butanediol, 1,4 butanediol, 5-pentanediol, 1,6-hexanehexane, 1,8-octanediol, 1,9-nonanediol, 3,3-dimethylolheptane, diethylene glycolone, dipropylene glycol, neopentyl glycol, cyclohexane mono 1 , 4-diol, other diols, glycerin, trimethylolpropane, pentaerythritol, etc. Polyester polyol obtained by polycondensation reaction from the triol compound is used.

 In addition, cyclic esters such as ε-force prolatatone, polyester amide polyols in which a part of the diol is changed to amines such as hexamethylene diamine and isophorone diamine can be used.

[0023] Polyether polyols include the above diols and polyols, or amines such as ethylene diamine, propylene diamine, toluene diamine, metaphenylene diamine, diphenylmethane diamine, and ethylene oxide. Polyether polyols obtained by addition polymerization of alkylene oxides such as propylene oxide, alkyls such as methyl daricidyl ether, phenyl daricidyl ether or cyclic ethers such as aryl glycidyl ether and tetrahydrofuran are used. . As the polycarbonate polyol, a polycarbonate polyol obtained by reacting the diols and polyols described in paragraph 0022 with ethylene carbonate, jetinorecarbonate, diphenolate carbonate and the like is used.

 [0025] (4) Aqueous acrylic resin and polyurethane resin

 The aqueous acrylic resin in the present invention has an active hydrogen group capable of reacting with a polyisocyanate curing agent, and the polymer chain is ionized or hydrophilized with a hydrophilic group.

 The polyurethane resin of the present invention is a urethane comprising the various diisocyanate compounds described in paragraph 0020 and the various dioli compounds (or polio Louis compounds) described in paragraphs 002:!-0024. A force produced by a reaction and having a hydrophilic main chain such as polyethylene glycol. The polymer chain is ionized or made hydrophilic with a hydrophilic group. For example, during the urethane reaction, a fatty acid having a divalent hydroxyl group at the end, such as 2, 2_dimethylolpropionic acid, can be incorporated into the main chain of the molecule to enhance water dispersibility.

 Resinization catalysts (urethanization catalysts) as curing catalysts (polymerization catalysts) for urethane reactions are used as needed, and metal catalysts such as dibutyltin dilaurate and zinc naphthenate, or triethylamine, tripropylamine, and tributyl. N-methylmorpholine, N-ethylmorpholine, dimethylbenzylamine, N, N, Ν ', N'-tetramethylhexamethylenediamine, bis (2-dimethylaminoethyl) ether, triethylenediamine , 1,2-dimethylimidazole, dimethylethanolamine, amine-based catalysts such as Ν, Ν-dimethyl- ノ ー ル -hexanolamine, etc., are used to increase the reaction rate and lower the reaction temperature. Can do.

[0026] (5) Polyisocyanate compound

 In the aqueous resin composition of the present invention, a polyisocyanate compound dispersible in the component (Α) is used as the component (Β) and functions as a curing agent component for curing the component (Α) as the main agent.

In the present invention, the curing agent for curing the aqueous resin is used as one component of a two-component system (two-component composition), which is derived from the power of hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI). A trimeric body with 3 or more NC ○ groups in one molecule An adduct body is used. A preferred example is an allophanate curing agent of hexamethylene disocyanate having 4 or more functional groups.

 Various modified products such as urethane modified products, urea modified products, allophanate modified products, biuret modified products, uretdione modified products, and isocyanurate modified products can be used as the trimer form adduct of these diisocyanates.

[0027] 2. Low molecular weight compound having an intercarbon unsaturated bond and an adjacent carbonyl group

 (1) As a component of the composition

 As the component (C) in the aqueous resin composition of the present invention, a low molecular weight compound having a carbon-carbon unsaturated bond and an adjacent carbonyl group is used.

 It is a component as an additive for modification of water-based polyurethane resin compositions, etc., and the chemical action of the modified additive suppresses the reactivity of isocyanate groups with water, and water-based polyurethane resin compositions. In the present invention, the pot life is sufficiently extended and the dispersibility of the aqueous polyurethane resin composition in an aqueous medium is sufficiently improved by the use of the modifier. It is an essential component.

 Component (C) is added in an amount of 0.01 to 30 parts by mass per 100 parts by mass of component (B). If the lower limit is not satisfied, the reforming effect is insufficient, and if the upper limit is exceeded, the gloss and physical properties of the obtained coating film are lowered, and the drying property is also deteriorated.

[0028] (2) About compounds

 Low molecular weight compounds having a carbon-carbon unsaturated bond and an adjacent carbonyl group are preferred to low molecular weight compounds having a number average molecular weight of less than 500 a, mainly unsaturated carbonyl compounds and α, β unsaturated carboxylic acid compounds Examples thereof include unsaturated aldehydes and unsaturated ketones, or unsaturated carboxylic acids, esters and anhydrides or unsaturated amides of unsaturated carboxylic acids, and various substituted derivatives thereof.

Specific examples include maleic acid, maleic acid ester, fumaric acid, fumaric acid ester, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, itaconic acid, itaconic acid ester, acrolein, Various materials such as methacrolein, crotonic acid, benzoquinone, isophorone can be used. The esters here are mainly used as diesters. Of these, unsaturated dicarboxylic acid diester, maleic acid dialkyl ester, is a representative compound, and the most suitable compounds are dimethyl maleate, dibutyl maleate and dioctyl maleate, which are demonstrated by the following examples. is there.

 [0029] (3) Action of compound

 A low molecular weight compound having an intercarbon unsaturated bond and an adjacent carbonyl group suppresses the reactivity of the isocyanate group with water, thereby sufficiently extending the pot life of the aqueous polyurethane resin composition, etc. The reason why the effect of the modifier brings about the effect of sufficiently improving the dispersibility of the aqueous polyurethane resin composition in the aqueous medium is still clearly clarified. It is presumed that the loose Mykenore addition reaction is involved.

 [0030] That is, a base present in the composition resulting from the reaction of an organic diisocyanate and water with respect to an unsaturated bond between carbon atoms of a low molecular weight compound having an unsaturated bond between carbon atoms and an adjacent carbonyl group. Aminoisocyanate, an active compound, reacts with Michael, and the secondary amino group of the addition reaction product reacts with the organic diisocyanate to form a saturated intercarbon bond, adjacent carbonyl group and substitution. It is presumed that the formation of organic diisocyanate having a urea group delays or prevents the reaction between the isocyanate group and water. In addition, when a low molecular weight compound having a carbon-carbon unsaturated bond and an adjacent carbonyl group has a hydrophobic group such as a long alkyl group, the hydrophobic group inhibits the access of the water molecule to the isocyanate group. Therefore, it is presumed that the reactivity of the isocyanate group with water is suppressed.

 [0031] 3. Other auxiliaries

 (1) Chain extender

 In the composition of the present invention, a chain extender in a usual polyaddition reaction may be used as necessary.

 As the chain extender, an ordinary low molecular compound having two or more active hydrogen groups is used. Specifically, ethylene glycol, propylene glycol, 1,4_butanediol, 1,5_pentanediol, Neopentyl glycol, diethanolamine, triethanolamine and the like are used.

[0032] (2) Additive As various additives in the composition, in order to enhance physical properties and add various physical properties, flame retardants, plasticizers, antioxidants, ultraviolet absorbers, dyes, pigments, fillers, internal mold release Agents, reinforcing materials, matting agents, conductivity-imparting agents, charge control agents, antistatic agents, lubricants, and other processing aids can be used.

 [0033] 4. Embodiment as a composition

 The aqueous polyurethane resin composition of the present invention is a two-component system composed of the (A) component as the main agent and the curing agent of the (B) component as described above, and is used as a two-component as a coating agent. This is a two-component composition material such as a paint composition or a two-component adhesive composition. When used as a paint, the two components are mixed and cured three-dimensionally with a polyfunctional NCO compound as a curing agent. Is done.

 In general, since the meaning of the coating composition is not necessarily unambiguous, in the present invention, it is a composition as a two-component assembled material that is not a composition in which all components are mixed beforehand.

 [0034] 5. Method for producing aqueous resin composition

 The aqueous resin composition of the present invention comprises a (B) component curing agent, a (C) component low molecular weight compound, and, if necessary, a dispersion aid dispersed in an aqueous medium as an aqueous dispersion, and the (A) component resin main component. It can manufacture by making it a composition.

 Specifically, a two-component composition comprising (1) a water-dispersed aqueous resin liquid, and (2) a dispersion in which a curing agent of component (B) and a low molecular weight compound of component (C) are dispersed in an aqueous medium. It is said. The two components are mixed when used as a coating agent such as paint.

 The additive for component (C) is preferably added in advance to component (A) or component (B), or added when mixing components (A) and (B).

 Example

 [0035] In the following, while disclosing the examples and contrasting the comparative examples, the present invention will be illustrated in more detail, the configuration of the present invention will be clarified, and each requirement of the configuration of the present invention will be described. Demonstrate the rationality of

 [Synthesis example of aqueous polyurethane resin]

Reactor with capacity of 3, OOOml equipped with stirrer, thermometer, nitrogen seal tube and cooler , Poly-Gene Nore A (Polytetramethylene Glycol Nore: Mn = 2,000 f = 2) 161.7 g, 2, 2 Dimethylolpropionic acid (DMPA) 10.5 g, Dipropylene glycol dimethyl ether (DMDPG ) Was charged with 63.8 g and dissolved by heating at 90 ° C for 10 minutes. After cooling to 60 ° C, 102.9 g of isocyanate A (HDI's isopropanol-modified alophanate compound: NC ○ = 19.1%) was charged and reacted at 80 ° C for 2 hours to obtain a carboxyl group-containing isocyanate group-terminated polymer solution. Obtained. The isocyanate content of this prepolymer solution was 3.40%, and the amount of carboxylic acid introduced into the prepolymer was 0.75 mmol / g.

 Next, 7.9 g of triethylamine (TEA) was added to neutralize the carboxyl group, and then 49.88 g of water and 5.4 g of cetyltriamine (DETA) were added while stirring, followed by emulsification and chain extension reaction between water and amine. For 12 hours at 30 ° C. When the presence of isocyanate groups was no longer confirmed by FT-IR, filling was performed to obtain aqueous polyurethane emulsion PU-1. The solid content of PU-1 is 32.5% and the pH is 9.5 and 25. The viscosity of C was 40 mPa's.

[0037] [Production of aqueous polyurethane resin composition]

 The aqueous polyurethane resin produced in the above synthesis example is blended with polyisocyanate A as a curing agent (methoxy-diethylene glycol modified form of 3-methylpentanediol-modified alophanate compound of HDI: NCO = 16.4%). Then, the modifying additives shown in Tables 1 and 2 were dispersed to obtain an aqueous polyurethane resin composition.

[0038] [Measurement of pot life as aqueous coating agent]

 (1) NCO residual ratio of water dispersion of (B) + (C) component%

 Defines the pot life as a coating agent in the aqueous polyurethane resin composition, the degree of inhibition of the reactivity of the isocyanate group with water, (B) + (C) the residual ratio of NCO groups in the aqueous medium, The appearance of the composition liquid was visually evaluated.

A total of 12g of curing agent polyisocyanate A (9.6g) and additive of Table 1 (2.4g) is mixed with 42g of water and stirred at 25 ° C-2,000rpmZ30sec, then 100ml bottle The container was left in a thermostatic bath at 25 ° C. Sampling was performed at the elapsed time shown in Table 1, and titration of NC units was performed to determine the percentage of 1 ^ 00 units remaining. Titration of NCO groups was carried out by adding a certain amount of dibutylamine to react, and then titrating the remaining amino group content of dibutylamine with hydrochloric acid. In addition, the appearance of the composition liquid was observed during the elapsed time described in Table 1. The results are posted in Table 1. did.

 The longer the remaining time of the coating agent is, the longer the retention rate value close to the theoretical NCO residual rate (100%) can be maintained, and the appearance does not change and foaming and insoluble matter do not occur. Become.

 [0039] (0) NC0 residual rate% of aqueous dispersion of components (A) + (B) + (C)

 An aqueous polyurethane resin composition is prepared by mixing two liquids of an aqueous polyurethane resin liquid as component (A) and a dispersion obtained by dispersing a curing agent of component (B) and a low molecular weight compound of component (C) in an aqueous medium. The degree of inhibition of the reactivity of the isocyanate group with water, which prescribes the pot life as a coating agent in the product, was evaluated by the residual ratio of NC0 group in the two-component mixed composition. After mixing 12g of polyisocyanate A (9.6g) as a curing agent and additive (2.4g) listed in Table 2 with 60g of the main agent, and stirring at 25 ° C-2,000rpm / 30sec The sample was left in a thermostatic bath at 25 ° C in a 100ml bottle container. Sampling was performed at a certain elapsed time, and titration of NCO groups was performed to determine the percentage of remaining NCO groups. Titration of NCO groups was carried out by adding a fixed amount of dibutylamine and reacting, and then titrating the amount of amino groups of the remaining dibutylamine with hydrochloric acid. The water resistance of the coating was also evaluated. The results are shown in Table 2.

 The longer the retention rate value, which is close to the theoretical NCO residual rate (100%), can be retained for a long time, the longer the pot life of the coating agent is.

[0040] [Viscosity of two-component mixed composition]

 The dispersibility of the aqueous dispersion of components (A) + (B) + (C) in the aqueous polyurethane resin composition in the aqueous polyurethane resin composition was evaluated by the viscosity value at 25 ° C. of the two-component mixed composition. Viscosity was measured by sampling over a certain period of time, and the results are shown in Table 2.

 The lower the measured viscosity value, the greater the viscosity reduction effect and the higher the dispersibility, and the better the workability and coating performance as a coating agent.

[0041] [Table 1] Example 1 Example 2 Comparative Example 1 Comparative Example 2 DBM DOM DEDEG DO A

 Immediately after stirring

 Milky white Milky white Translucent Milky white

2 h r later 100 86. 4 92. 2 100

2.5 hours after

 Foam

 0 after 3 hours

 Insoluble matter generation

 After 4 hours 100 80. 7 92. 8

4.5 hours after

 Foam

5 hr later 100 1 9. 3 0

 Insoluble matter generation

5.5 hours later 0

 Insoluble matter generation

 After 6 hours 80.9

6.5 hours after

 Foam

 7.5 After 5 hours 0

 Insoluble matter generation

 N C O = 0% 7 to 7.5 5 h r 5 to 5.5 h r 2.5 to 3 h r 4.5 5 to 5 h r

(Explanation of symbols in Table 1)

 DBM; Dibutyl maleate DOM; Dioctyl maleate DEDEG; Diethylene glycol jetyl ether D0A; Dioctyl adipate

[Table 2] Component c Component B / C = 80/20 Component A, (B + C) =

 1 00 No 20 Dispersion composition Viscosity N C O content Gelation time 4 hours after coating

 (mPa. s, 25% (%) (hr) Water resistance

 None 2 700 1 6. 4 3 X

 DEDEG 200 1 3. 1 3. 5 X Comparison example DMDPG 250 1 3. 1 3. 5 X

 DOA 2 50 1 3. 1 4 ~ 4.5 X

PC 450 1 3. 1 4 ~ 4.5 X

 DEM 500 1 3. 1 5 to 5.5 〇

 DBM 700 1 3. 1 6 o

 Example

 DOM 800 1 3. 1 7 O

[0043] (Water resistance test described in Table 2)

 After painting, a 50 ° C '3 hour immersion test was conducted. After the test, the coating film was observed visually and by finger touch. According to Table 2, “○: Good △: Almost good X: Evaluation that “whitening and stickiness occurs in the coating film and water resistance is low” is described. (Explanation of symbols in Table 2)

 DEM; Jetyl maleate DMDPG; Dipropylene glycol dimethyl ether PC: Propylene carbonate

[0044] [Consideration of results of Examples and Comparative Examples]

 By comparing each of the above Examples and Comparative Examples, in the aqueous polyurethane resin composition of the present invention, the low molecular weight compound having a carbon-carbon unsaturated bond and an adjacent carbonyl group as a modifier. Compared with the comparative example, which is a conventional example using a compound having no carbon-carbon unsaturated bond or adjacent carbonyl group, the pot life is sufficiently extended, and the dispersion in the aqueous medium Good workability and coating performance as a coating agent, and as a coating agent, whitening and stickiness of the coating do not occur in a humid atmosphere, and the coating has excellent water resistance. It has been revealed.

Specifically, in Examples 1 and 2 in Table 1, in the aqueous composition of components B and C, stirring was performed. In the comparative example 1, the NCO group remaining rate is close to the theoretical value (100%) for 4 hours or more immediately after stirring, and the aqueous composition foams and generates insolubles and becomes unusable after 5 hours. Only after 2 hours of stirring, it is close to the theoretical value only for 2 hours, and the residual ratio of NC0 group is not shown. The aqueous composition foams and becomes insoluble and becomes unusable after 2.5 hours. Comparative Example 2 In Comparative Example 1, DOA is more hydrophobic than DEDEG of Comparative Example 1 and the isocyanate is somewhat protected from water, and the residual rate of NCO is higher than Comparative Example 1, but the residual rate is inferior to Examples 1 and 2. In the aqueous composition of the present invention, the superiority of the action time extension effect of Component C is demonstrated.

 Further, in any of the components C in the examples in the aqueous resin composition of Table 2, the gelation time is greatly extended and the water resistance of the coating film is good as compared with the components in the comparative example. It has been revealed. From the viscosity data, the workability and film performance as a coating agent with a large viscosity reducing effect and high dispersibility are improved as compared with the conventional example in which component C is not added.

 From the above data results and discussion, the rationality and significance of the constituent elements of the present invention are demonstrated, and it can be said that the present invention has remarkable excellence compared to the prior art. The

Industrial application fields

 In the present invention, the pot life of the isocyanate curable aqueous resin composition can be sufficiently extended, and the dispersibility of the aqueous resin composition in an aqueous medium can be sufficiently improved, thereby the resin. The composition is uniform, the viscosity of the resin composition is reduced, the workability as a coating agent is improved, and the coating film appearance, hardness and water resistance are not inferior to those of conventional organic solvent polyurethane resin coating agents. In the industry, it is useful as a water-based resin coating agent, and is particularly useful in the field of paints.

Claims

The scope of the claims  [1] A resin composition containing a water-dispersible resin main component as component (A), a polyisocyanate compound that can be dispersed in component (A) as component (B), and carbon-carbon unsaturated as component (C) A water-based resin composition comprising a low molecular weight compound having a bond and an adjacent carbonyl group.  [2] As the component (A), an aqueous acrylic resin main component, or an aqueous polyurethane prepolymer base obtained by reacting a polyol with a diisocyanate compound, and as a component (B), dispersible in the component (A) It contains a curing agent that is a trimer or adduct of diisocyanate compound, and (C) component is a low molecular weight compound with a number average molecular weight of less than 500, and (B) / (A) component mass ratio 0.01 to 0.50, and (C) component strength S (B) component is added in an amount of 0.01 to 30 parts by mass with respect to 100 parts by mass, and the resin composition is a coating composition. The aqueous resin composition according to claim 1.  [3] The curing agent of the component (B) is an allophanate curing agent of hexamethylene diisocyanate having 4 or more functional groups, and the component (C) is an unsaturated dicarboxylic acid diester. The aqueous polyurethane resin composition according to claim 2.  4. The aqueous polyurethane resin composition according to claim 3, wherein the unsaturated dicarboxylic acid diester is a maleic acid dialkyl ester.  [5] The aqueous polyurethane resin composition according to any one of claims 2 to 4, wherein the coating composition is a coating composition.  [6] The aqueous polyurethane resin composition is a two-component coating composition, and is a two-component composition material of (A) an aqueous polyurethane resin as a component and (B) a polyisocyanate as a curing agent. When used as a paint, the two components are mixed, and the additive of component (C) is added in advance to component (A) or component (B), or when (A) and component (B) are mixed 6. The aqueous polyurethane resin composition according to claim 5, which is added.  [7] A curing agent of component (B), a low molecular weight compound of component (C), and, if necessary, a dispersion aid are dispersed in an aqueous medium to form an aqueous dispersion. The method for producing an aqueous resin composition according to claim 1 or 2, wherein the composition is a composition.