JPH10195142A - Production of aqueous reactive resin dispersion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing an aqueous reactive resin dispersion which is excellent in storage stability, free from discoloration and excellent in workability and can give cured films excellent in water resistance. SOLUTION: A polymer obtained by polymerizing at 150-310 deg.C at least one (meth)acrylate having at least one carboxyl group and optionally at least one monomer having at least one ethylenic unsaturation and having an acid value of 50-500, a number-average molecular weight of 1,000-15,000 and having (meth) acryloyl groups and carboxyl groups is dissolved or dispersed in an alkaline aqueous medium, and a (meth)acrylate having one epoxy group is reacted with the polymer by an addition reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aqueous dispersion of a reactive resin which can be cured by irradiation with an active energy ray such as an electron beam or an ultraviolet ray, or at room temperature or by heating. The reactive resin aqueous dispersion to be used is useful in various industrial fields as a paint, a printing ink, an adhesive, a filler, a molding material, a resist and the like. In the present specification, acrylate and / or methacrylate are represented by (meth) acrylate, acryloyl group and / or methacryloyl group are represented by (meth) acryloyl group, and acrylic acid and / or methacrylic acid are represented by (meth) acrylic acid. . The unit of the acid value is m
It is shown in gKOH / g in terms of solid content.

[0002]

2. Description of the Related Art In recent years, organic solvents used in various industries, etc.,
Air pollution on a global scale due to the release of detergents and the like into the atmosphere has progressed, and there is a concern about the effects on living organisms. For this reason, attempts have been made to make the resin compositions used for various paints, inks, adhesives and the like solvent-free by making them water-based. As one method of making the reactive resin aqueous,
Addition reaction of a compound having an epoxy group and an unsaturated group to a polymer having a carboxyl group to introduce an unsaturated group, which is a reactive group, into the polymer to produce a reactive resin having a carboxyl group and an unsaturated group There is a method in which the resin is neutralized with an alkali and, if necessary, suspended or emulsified in water or an aqueous solution containing an organic solvent such as an alcohol using an emulsifier (hereinafter referred to as a method A; -17
No. 922 and No. 51-23531). As another method, there is a method of producing a polymer having a carboxyl group in water in the presence of a surfactant, and subjecting the obtained polymer to an addition reaction with a compound having an epoxy group and an unsaturated group ( The method B is hereinafter referred to as JP-A-6-212950).

[0003]

In the above method A, the reaction of adding a compound having an epoxy group and an unsaturated group to a polymer having a carboxyl group is carried out in a solvent such as a hydrophilic alcohol or ketone. Although the reaction is carried out using a catalyst such as an amine, the reaction is not sufficiently reactive,
The reaction required a long time. In order to increase the reactivity, there is a method of increasing the amount of a catalyst such as an organic amine.However, in this case, since the amount of the catalyst increases, the catalyst forms a large amount of salt with a polymer having a carboxyl group. This has the problem that the resulting adduct is difficult to dissolve in the solvent. In addition, when the obtained reactive resin is made aqueous, not only the operation of removing the solvent contained therein by evaporation or the like is necessary, but also it is difficult to completely remove the solvent from the reactive resin. As a result, the product has an odor, and it takes a long time to remove the solvent as much as possible. As a result, the reactive resin is exposed to an anaerobic atmosphere which promotes the curing reaction. Due to exposure for a long time, the storage stability of the final product may be deteriorated, or the product may be colored. In the case of Method B, the resulting aqueous dispersion of the reactive resin contains a surfactant in the liquid, so that the cured film of the reactive resin has poor water resistance. The present inventors have excellent storage stability of the product,
The inventor has conducted intensive studies on an industrially advantageous method for producing an aqueous dispersion of a reactive resin having no coloring, having excellent curability and workability, and having a cured film having excellent water resistance.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have found that a polymer having a specific carboxyl group is used and a reactive resin is produced by a specific method. Was found to be effective, and the present invention was completed. Hereinafter, the present invention will be described in detail.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

(Polymer having (meth) acryloyl group and carboxyl group) In the production method of the present invention, as a polymer serving as a skeleton of the reactive resin, a (meth) acrylate having one or more carboxyl groups [hereinafter referred to as a carboxyl group-containing ( Meth) acrylate] or (meth)
(Meth) acryloyl obtained by polymerizing acrylate and one or more other monomers having one ethylenically unsaturated group (hereinafter referred to as ethylenically unsaturated monomers) under specific conditions A polymer having a group and a carboxyl group (hereinafter simply referred to as a carboxyl group-containing polymer) is used.

Various carboxyl group-containing (meth) acrylates can be used. For example, a Michael addition reaction of an unsaturated carboxylic acid such as (meth) acrylic acid, crotonic acid, cinnamic acid or (meth) acrylic acid can be used. And ω-carboxypolycaprolactone mono (meth) acrylate, monohydroxyethyl phthalate (meth) acrylate and monohydroxyethyl succinate (meth) acrylate.

The carboxyl group-containing polymer may be a homopolymer or a copolymer of a carboxyl group-containing (meth) acrylate, or may be a copolymer of the carboxyl group-containing (meth) acrylate and an ethylenically unsaturated monomer. It may be a polymer. As the ethylenically unsaturated monomer, various ones other than the above-mentioned carboxyl group-containing (meth) acrylate can be used. For example, styrene, α-methylstyrene, (meth) acrylonitrile, vinyl acetate, and (meth) Acrylate and the like. Specific examples of (meth) acrylate include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, and cyclohexyl. Alicyclic alkyl (meth) acrylates such as (meth) acrylate, substituted aryl (meth) acrylates such as benzyl (meth) acrylate, and alkoxy (such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate) Examples include meth) acrylates, isobornyl (meth) acrylates, and hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate.

The copolymerization ratio of the carboxyl group-containing (meth) acrylate and the ethylenically unsaturated monomer is determined on condition that the acid value of the obtained carboxyl group-containing polymer is a value satisfying the following acid value. Is optional.

The carboxyl group-containing polymer used in the present invention must have an acid value of 50 to 500, preferably 100 to 300. If the acid value is less than 50, the dissolution of the carboxyl group-containing polymer in an alkaline aqueous medium during the addition reaction with (meth) acrylate having one epoxy group (hereinafter referred to as epoxy group-containing (meth) acrylate) described below. However, there is a problem that the addition reactivity is reduced or the dissolution or dispersion takes time due to insufficient properties or dispersibility. As a means for improving the solubility or dispersibility of the carboxyl group-containing polymer, there is also a method of lowering the solid concentration of the carboxyl group-containing polymer in the aqueous solution or dispersion, but in this case, the obtained reactive resin aqueous dispersion is obtained. However, since it contains a large amount of aqueous medium, it has poor drying properties. On the other hand, when the acid value is higher than 500, the viscosity of the obtained reactive resin aqueous dispersion becomes high.

The number average molecular weight of the carboxyl group-containing polymer must be 1,000 to 15,000, preferably 2,000 to 10,000. If this value is 1,
If the molecular weight is smaller than 000, the resulting reactive resin will have poor adhesion and adhesion to the substrate, and the coating film will not have sufficient strength. On the other hand, if this value is 15,000
When it exceeds 0, the solubility or dispersibility in an alkaline aqueous medium becomes poor as in the case where the acid value is less than 50. If the solid content of the carboxyl group-containing polymer is lowered, the solubility or dispersibility can be improved, but the resulting reactive resin aqueous dispersion becomes poor in drying property. Further, such a carboxyl group-containing polymer having a high number average molecular weight is inferior in reactivity with an epoxy group-containing (meth) acrylate, so that the ratio of (meth) acryloyl groups introduced into the reactive resin becomes insufficient. The resulting reactive resin is inferior in curability, and the hardness and strength of the coating film decrease. In the present invention, the polydispersity (Mw / Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the copolymer, is used.
However, it is preferable to use one having 3 or less, more preferably 2.5 or less. A carboxyl group-containing polymer having a polydispersity in this range has excellent solubility in an alkaline aqueous medium, and is particularly suitable for producing a low-viscosity reactive resin aqueous dispersion. In the present invention, the number average molecular weight and the weight average molecular weight are values obtained by using tetrahydrofuran as a solvent and converting the molecular weight measured by gel permeation chromatography (hereinafter abbreviated as GPC) based on the molecular weight of polystyrene. is there.

In the present invention, a carboxyl group-containing (meth) acrylate or a polymer obtained by polymerizing the (meth) acrylate with an ethylenically unsaturated monomer at a high temperature of 150 to 310 ° C. is used as the carboxyl group-containing polymer. use,
Preferably, those obtained by continuous high-temperature polymerization are used. According to this high-temperature continuous polymerization method, it is possible to obtain a polymer having a lower polydispersity than that obtained by conventional solution polymerization, and it is not necessary to use a thermal polymerization initiator or use a thermal polymerization initiator. Even in this case, since a carboxyl group-containing polymer having a target molecular weight can be obtained with a small amount of use, a highly pure carboxyl group-containing polymer containing almost no impurities that generate radical species by heat or light can be obtained. The addition reaction between the carboxyl group-containing polymer and the epoxy group-containing (meth) acrylate described in the above can be performed stably, and the finally obtained reactive resin aqueous dispersion has excellent storage stability. It has excellent weather resistance.

Some proposals have already been made for the high-temperature continuous polymerization method, for example, Japanese Patent Application Laid-Open No. 57-502171.
And the known methods disclosed in JP-A-59-6207 and JP-A-60-215007. For example, after filling a pressurizable reactor with a solvent and setting a predetermined temperature under pressure, a carboxyl group-containing (meth) acrylate, the (meth) acrylate and an ethylenically unsaturated monomer, or an Accordingly, there is a method in which a monomer mixture comprising a polymerization solvent is supplied to the reactor at a constant supply rate, and an amount of the reaction solution corresponding to the supply amount of the monomer mixture is withdrawn.
When a polymerization solvent is used, the solvent charged into the reactor at the start of the reaction and the polymerization solvent mixed with the monomer mixture may be the same or different. As the solvent or polymerization solvent, aliphatic hydrocarbons, aromatic hydrocarbons such as toluene, xylene, cumene and ethylbenzene, cellosolves such as butyl cellosolve and glycol ethers such as carbitol, glymes such as ethylene glycol dimethyl ether and diglymes such as diethylene glycol dimethyl ether Such as ethers, ethyl acetate, butyl acetate, cellosolve acetate, methyl propylene glycol acetate, carbitol acetate and ethyl carbitol acetate, etc., ketones such as acetone and methyl ethyl ketone, hexanol, decanol, ethylene glycol, propylene glycol and butylene glycol Such as aliphatic alcohols, aromatic alcohols such as benzyl alcohol and toluene alcohol, and Ethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, can be used polyalkylene glycols such as tetramethylene glycol and polytetramethylene glycol. The usage ratio of the polymerization solvent is preferably 200 parts by weight or less based on 100 parts by weight of the monomer mixture. Also, the monomer mixture, if necessary, can be mixed with a thermal polymerization initiator, the thermal polymerization initiator that can be used in this case is not particularly limited,
Examples include an azonitrile initiator and a peroxide-based initiator. Azonitrile-based initiators include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile) and 2,2′-azobis (2,4-dimethylvaleronitrile) And the like, and peroxide-based dispersing agents include hydrogen peroxide, di-t-butyl peroxide, benzoyl peroxide and the like. When the thermal polymerization initiator is blended with the monomer mixture, the amount is preferably 0.001 to 5 parts by weight based on 100 parts by weight of the monomer mixture. Reaction temperature is 150-310 ° C
Must. If the temperature is lower than 150 ° C., there are problems such as the molecular weight of the obtained polymer being too large and the reaction rate being slow. The liquid is colored, the addition reaction described later becomes unstable, and the obtained reactive resin becomes unstable. The pressure does not affect the reaction and depends on the reaction temperature and the boiling point of the monomer mixture and the solvent to be used. Any pressure may be used as long as the reaction temperature can be maintained. The residence time of the monomer mixture is preferably 2 to 60 minutes. When the residence time is less than 2 minutes, the amount of unreacted monomers increases, and the yield of the carboxyl group-containing polymer may decrease. On the other hand, when the residence time exceeds 60 minutes, the productivity may be reduced. Causes a decline.

A method for producing an aqueous dispersion of a reactive resin In the production method of the present invention, the polymer is dissolved or dispersed in an alkaline aqueous medium, and the epoxy group of the epoxy group-containing (meth) acrylate is converted to the polymer. Is subjected to an addition reaction to the carboxyl group. In the present invention, the addition reaction is performed not in an organic solvent but in an alkaline aqueous medium. Since high concentrations of alkali components that act as catalysts for addition reactions in water can be present, addition reactions in aqueous media are much faster than reactions in organic solvents, and the reactivity obtained in addition reactions Since the resin is obtained as a dispersion, the resin has low viscosity and excellent coatability. Furthermore, compared with a method of producing an aqueous dispersion of a reactive resin by adding an epoxy group-containing (meth) acrylate in an organic solvent and then removing the solvent and then dispersing the same in water, the present invention provides a reactive resin dispersion. Is obtained as a water dispersion in one step, and thus the obtained reactive resin water dispersion has no problems such as odor and coloring.

As the manufacturing method, various methods can be adopted.
For example, a carboxyl group-containing polymer is dissolved or dispersed in an alkaline aqueous medium, and the aqueous solution or dispersion is
A method in which an epoxy group-containing (meth) acrylate is added, followed by heating and stirring. The reaction temperature in this case is preferably from 60C to 100C. By the addition reaction, when the carboxyl group-containing polymer is dissolved in an alkaline aqueous medium, it becomes a reactive resin and becomes dispersed in water, and when the polymer is dispersed in an alkaline aqueous medium, the reaction proceeds. The resin is maintained in a dispersed state in water as it is.

In the production method of the present invention, glycidyl (meth) acrylate is used as the epoxy group-containing (meth) acrylate to be added to the carboxyl group of the carboxyl group-containing polymer, and the reactive resin obtained is present in the molecule. The ratio of the (meth) acryloyl group is high and the reactivity is excellent, which is preferable.

The reaction ratio of the epoxy group-containing (meth) acrylate to the carboxyl group in the carboxyl group-containing polymer is such that the acid value of the reactive resin after the addition reaction is 20 to 20.
A ratio of 200 is preferred. When the acid value of the reactive resin after the addition reaction is less than 20, the dispersibility of the resulting aqueous dispersion of the reactive resin is not sufficient, and the resin component may aggregate or precipitate. On the other hand, when the acid value exceeds 200, the produced reactive resin is dissolved without dispersing in water, so that the viscosity is so high that it is difficult to handle.
When the viscosity of the water dispersion becomes high, the viscosity can be lowered by lowering the solid content of the reactive resin, but the water dispersion becomes insufficient in drying property.

In the alkaline aqueous medium used as the reaction medium, various kinds of alkalis can be used, and examples thereof include ammonia, organic amines and inorganic bases such as sodium hydroxide. Ammonia and low-molecular-weight organic amines are preferred because they can be evaporated and scattered from and maintain the water resistance of the resulting coating film. As the low molecular weight organic amine, trialkylamines such as trimethylamine, triethylamine and tributylamine, and hydroxyalkylamines such as N, N-dimethylethanolamine, N-methyldiethanolamine and triethanolamine can be used.

The concentration of the alkali component in the alkaline aqueous medium is preferably such that the alkali component accounts for 30 to 70 mol% based on the total amount of the carboxyl groups in the carboxyl group-containing polymer. When this proportion is less than 30 mol%, the carboxyl group-containing polymer may be difficult to dissolve or disperse in an aqueous medium, while when it exceeds 70 mol%, the resulting reactive resin aqueous dispersion may be difficult to dissolve or disperse. The odor of ammonia or amine used as an alkali component may remain. The amount of the alkaline aqueous medium used in the addition reaction is preferably such that the solid content concentration of the obtained reactive resin aqueous dispersion is 10 to 60% by weight.

The alkali component in the alkaline aqueous medium functions as a catalyst, and the addition reaction proceeds, but a catalyst can be further added if necessary. Examples of the catalyst include high molecular weight tertiary amines such as N, N-dimethylbenzylamine and N, N-dimethylaniline; and quaternary ammonium salts such as tetradiethylammonium chloride, tetrabutylammonium bromide and benzyltrimethylammonium chloride. Hydrochlorides of secondary amines such as diethylammonium chloride; and phosphorus compounds such as triphenylphosphine. The preferable addition amount of these catalysts is 0.1 to the solid content in the reaction solution.
It is 1 to 10% by weight, more preferably 0.1 to 5% by weight.

In the addition reaction, it is preferable to add a polymerization inhibitor such as hydroquinone and hydroquinone monomethyl ether or to blow molecular oxygen in order to stably perform the reaction. When a polymerization inhibitor is used, the amount is preferably 10 wtppm to 2% by weight based on the reaction solution.

Method for Using Reactive Aqueous Resin Dispersion The reactive resin aqueous dispersion obtained by the production method of the present invention can be cured by irradiation with an active energy ray such as an electron beam or ultraviolet ray, or at room temperature or by heating. It can be used for various purposes such as paints, printing inks, adhesives, fillers, molding materials, resists, etc. as such or in combination with the various components described below.

The reactive resin aqueous dispersion may optionally contain
An active energy ray-curable monomer which is a reactive diluent can be blended. Active energy ray-curable monomers include 2-hydroxyethyl (meth) acrylate,
Hydroxyalkyl (meth) acrylates such as 2-hydroxypropyl (meth) acrylate; mono- or di (meth) acrylates of ethylene glycol, mono (meth) acrylates of methoxyethylene glycol, mono- or di (meth) acrylates of tetraethylene glycol; Mono- or di- (meth) acrylates of glycols, such as mono- or di- (meth) acrylates of tripropylene glycol; and trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate or pentaerythritol tetra (meth) acrylate and di Examples thereof include polyols such as pentaerythritol hexaacrylate and (meth) acrylates of alkylene oxide adducts thereof. The active energy ray-curable monomer has a solid content of 100 of the reactive resin aqueous dispersion.
It is preferable to mix at a ratio of 1 to 150 parts by weight per part by weight.

If necessary, the reactive resin aqueous dispersion may contain a filler such as barium sulfate, silicon oxide, talc, clay and calcium carbonate, and a coloring such as phthalocyanine blue, phthalocyanine green, titanium oxide and carbon black. Various additives such as a pigment for use, an adhesion-imparting agent, and a leveling agent, and a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, phenothiazine, and aluminum salt of N-nitrosophenylhydroxylamine can also be blended. When these are blended, the blending ratio is preferably 100 parts by weight or less based on 100 parts by weight of the solid content of the aqueous dispersion of the reactive resin.
When the polymerization inhibitor is compounded, the compounding ratio is preferably 0.00001 to 2% by weight based on the solid content of the reactive resin aqueous dispersion.

The method of irradiating active energy rays and the method of heating when curing the reactive resin may be a general method known as a method of curing a radical polymerizable compound.

In the case of curing at room temperature or by heating, a polymerization initiator such as an azonitrile-based initiator and a peroxide-based initiator is added to the aqueous dispersion of the reactive resin. Specific examples of the azonitrile-based initiator and the peroxide-based initiator can be the same as those used in the above-described high-temperature continuous polymerization. The preferable ratio of the polymerization initiator is 0.001 to 5 parts by weight based on 100 parts by weight of the solid content of the aqueous dispersion of the reactive resin.

When curing by irradiation with ultraviolet rays as active energy rays, a photopolymerization initiator is added to the aqueous dispersion of the reactive resin. When curing by electron beam, it is not necessary to mix a photopolymerization initiator. Preferable examples of the photopolymerization initiator include Darocure 2959, 1173, and 111 which are water-soluble or hydrophilic photopolymerization initiators.
6, Irgacure 184 (manufactured by Ciba Geigy), Kantacure ABQ, BTC, and QTX (manufactured by Shell Chemical Co., Ltd.). ,
Benzophenone, benzyldimethyl ketal and 2,4
-Dimethylthioxanthone and the like can also be used. If necessary, two or more photopolymerization initiators can be used in combination. The photopolymerization initiator is preferably blended in an amount of 0.1 to 10% by weight based on the solid content of the reactive resin aqueous dispersion. As a method of adding the photopolymerization initiator, when using a photopolymerization initiator having low solubility in water, after previously dissolving in an active energy ray-curable monomer that is a reactive diluent, It is preferably added together with. When a water-soluble or hydrophilic photopolymerization initiator is used, it can be added by heating and mixing as it is.

When the reactive resin obtained in the present invention is cured by irradiation with an active energy ray, a water dispersion of the reactive resin is usually applied to a substrate, and water as a dispersion medium is then used as an alkali component. When ammonia or a low molecular weight organic amine is used, it is preferable that water and ammonia or the low molecular weight organic amine be evaporated and scattered by heating. If moisture remains in the cured coating film, the film strength may be insufficient or the transparency of the film may be impaired.

[0028]

The present invention will be described more specifically with reference to the following Examples and Comparative Examples. In the following, parts and% are based on weight. Example 1 Production of Carboxyl Group-Containing Polymer A 300-ml pressurized stirred tank reactor equipped with an electric heater was filled with diethylene glycol monoethyl ether, the temperature was raised to 250 ° C., and the pressure was adjusted with a pressure controller. Gauge pressure was maintained at 25-27 kg / cm ² . Then, while keeping the pressure of the reactor constant, 30 parts of acrylic acid as a carboxyl group-containing (meth) acrylate, 70 parts of styrene as an ethylenically unsaturated monomer, and di-t-butyl peroxide 0 as a thermal radical initiator. .1
Part of the monomer mixture A-1 was continuously supplied from the raw material tank to the reactor at a constant supply rate (23 g / min, residence time: 14 minutes), and the amount of the monomer mixture A-1 supplied The reactant corresponding to was continuously extracted from the outlet. Immediately after the start of the reaction, after the reaction temperature once decreased, a temperature increase due to the heat of polymerization was observed, but by controlling the heater,
The reaction temperature was maintained at 270-271 ° C. One hour after the start of the supply of the monomer mixture A-1 in which the temperature was stabilized, the starting point of the withdrawal of the reaction solution as a raw material for the next esterification reaction was defined. As a result of continuing the reaction for 3 hours, 4140 g
Was supplied, and 4130 g of a reaction product was recovered. The reaction liquid was introduced into a thin film evaporator, and volatile components such as unreacted monomers were separated to obtain 3800 g of a product (copolymer B-1). From the gas chromatograph,
There was no unreacted monomer in the concentrate. The number average molecular weight (hereinafter abbreviated as Mn) of the copolymer B-1 obtained by using GPC and the molecular weight determined by GPC using tetrahydrofuran as a solvent is 4,100, and the weight average molecular weight (hereinafter abbreviated as Mw) is 8 , 250 and the polydispersity was 2.0. The acid value of the product was 220.

Production of Reactive Resin Aqueous Dispersion In a flask equipped with a stirrer and a cooling tube, 50 g (0.196 eq) of copolymer B-1 and 6% of 25% aqueous ammonia were added.
0 g and 186 g of water were added, heated to 70 ° C., and stirred to dissolve the copolymer B-1. After completely dissolving the copolymer, 13.9 g of glycidyl methacrylate (0.0
98 mol) and hydroquinone monomethyl ether 32
mg, stirred at 75 ° C. for 2 hours, and the viscosity was 10 cps / 25.
256 g of a reactive resin aqueous dispersion C-1 having a solid content of 25% and an acid value of 87 in terms of solid content was obtained.

Examples 2 to 4 The same as Example 1 except that the carboxyl group-containing (meth) acrylate, the type of the ethylenically unsaturated monomer, and the charged parts by weight were changed according to Table 1. The reaction was carried out in the same manner to produce a carboxyl group-containing polymer. Table 1 shows the molecular weight and acid value of the obtained carboxyl group-containing polymer. Using each of the obtained polymers, an addition reaction of glycidyl methacrylate was carried out in exactly the same manner as in Example 1 except that the reaction was carried out under the conditions shown in Table 2, thereby producing an aqueous dispersion of a reactive resin. Table 2 shows the acid value and viscosity of the obtained aqueous dispersion of reactive resin.

Comparative Example 1 In a four-necked flask equipped with a reflux condenser, a thermometer, a dropping funnel, a glass tube for purging nitrogen and a stirrer, 300 g of the same monomer mixture A-1 as in Example 1 was added. 700 g (hereinafter abbreviated as MEK) and 9 g of 2,2′-azobisisobutyronitrile were charged, and a polymerization reaction was carried out at 80 ° C. for 4 hours while blowing nitrogen to obtain a reaction product F-1. 350 g of the reaction product F-1 was introduced into a thin film evaporator, and volatile components such as an unreacted monomer and a solvent were separated to obtain 80 g of a product (copolymer D-1). According to gas chromatography, no unreacted monomer was present in the concentrated liquid. Mn of copolymer D-1 determined by GPC using tetrahydrofuran as a solvent
Was 10,500, Mw was 34,250, and the polydispersity was 3.3. The acid value of the product was 240. In a flask equipped with a stirrer and a condenser, copolymer D-
50 g (0.214 eq) of 1, 6.5 g of 25% aqueous ammonia and 189 g of water were added, heated to 75 ° C., and stirred to dissolve. After complete dissolution, 15.2 g (0.107 mol) of glycidyl methacrylate and 33 mg of hydroquinone monomethyl ether were charged, and the mixture was stirred at 70 ° C for 2 hours. The viscosity was 124 cps / 25 ° C, the solid content was 25%, and the acid value in terms of solid content was 94. 294 g of a reactive resin E-1 was obtained.

Comparative Example 2 166 g of the reaction product F-1 of Comparative Example 1 (copolymer D-1 (0.214e
q) and 116 g of MEK], 15.2 g (0.107 mol) of glycidyl methacrylate, 0.65 g of triethylamine, and 33 mg of hydroquinone monomethyl ether, and stirred at 90 ° C for 6 hours. 11 g of triethylamine was added to the obtained reaction solution,
After stirring for 10 minutes, a dispersion was prepared by adding 225 g of water, and the pressure was reduced to remove the solvent in the dispersion. 280 g of a reactive resin E-2 having a viscosity of 225 cps / 25 ° C., a solid content of 29%, and an acid value in terms of solid content of 99 was obtained.

[0033]

[Table 1]

[0034]

[Table 2]

評 価 Evaluation The aqueous dispersion of the reactive resin obtained in each example was evaluated by the following method. Table 3 shows the results.

Workability evaluation ○: No problem in work. Δ: The viscosity is somewhat high, but it can be handled. . X: It is difficult to handle because of high viscosity.

Heating stability test The aqueous dispersion of the reactive resin obtained in each example was subjected to heating at 40 ° C for 20 hours.
After standing for 0 hours, the appearance was evaluated by visual observation. A: No change at all. ：: Almost no increase in viscosity. Δ: Viscosity increased. ×: Aggregates and precipitates were generated.

Curability test Irgacure 2959 [manufactured by Ciba Geigy Co., Ltd.] with respect to 100 parts of the solid content of the obtained aqueous dispersion of the reactive resin.
Two parts were blended to produce a composition. This composition was treated with a bonderite steel sheet PB-144 [Japan Test Panel Co., Ltd.
Manufactured at a film thickness of 20 microns, dried in an oven at 80 ° C. for 5 minutes, and then irradiated with ultraviolet light at a lamp height of 10 cm using a 80 W / cm, one condensing high-pressure mercury lamp. The irradiation dose required for curing was measured. In the table, ◎, △, Δ and × have the following meanings. ◎: Completely cured at less than 500 mJ / cm2 ○: Cured at 500 to less than 1000 mJ / cm2 △: Cured at 1000 mJ / cm2 or more ×: Not cured at 1000 mJ / cm2 or more

Hardness The cured film obtained by the curability test was evaluated according to JIS “Hand-drawing method K5400”.

Evaluation of coloring The coloring of the cured film obtained by the curability test was visually evaluated. In the table, ○, Δ, and × have the following meanings. ：: no coloring is observed at all Δ: slight coloring is observed ×: coloring is observed

[0041]

[Table 3]

[0042]

According to the production method of the present invention, the addition reactivity of an epoxy group-containing (meth) acrylate to a carboxyl group-containing polymer is industrially advantageously carried out, and the obtained reactive resin aqueous dispersion is With low viscosity, excellent workability, no coloring, excellent storage stability, or a composition comprising the resin, curable, heat stable and excellent transparency, paint, printing ink, It can be used for various applications such as adhesives, fillers, molding materials, and resists, and its industrial value is extremely large.

Claims (2)

[Claims] (1) at least one kind of (meth) acrylate having at least one carboxyl group or at least one kind of monomer having at least one other ethylenically unsaturated group; A polymer having a (meth) acryloyl group and a carboxyl group having an acid value of 50 to 500 and a number average molecular weight of 1,000 to 15,000, which is obtained by polymerization at a polymerization temperature of 150 to 310 ° C., is converted to an alkaline solution. Dissolved or dispersed in an aqueous medium of
A method for producing an aqueous dispersion of a reactive resin, comprising adding (meth) acrylate having two epoxy groups to an addition reaction. 2. The aqueous dispersion of a reactive resin according to claim 1, wherein the polymer having a (meth) acryloyl group and a carboxyl group has an acid value of 100 to 300 and a number average molecular weight of 2,000 to 10,000. How to make the body.