JPS63258913A - Hardening water-based resin dispersion - Google Patents

Abstract

PURPOSE:To obtain the title dispersion that is obtained by emulsion polymerization of polymerizable monomers reactive with carboxyl groups using a polymer or its salt bearing specific water-soluble or water-dispersible alkyl groups as an emulsifier, thus showing excellent storage stability and giving coating films of high resistance to water. CONSTITUTION:The subject dispersion is obtained by emulsion polymerization of polymerizable monomers (A) of (i) 0.5-40wt.% of a monomer bearing a group reactive with carboxyl group and (ii) 60-99.5wt.% of other polymerizable monomers using, as an emulsifier, (B) a polymer or its salt having 200 or more acid value and bearing water-soluble or -dispersible terminal alkyl groups, formed by polymerization of (iii) polymerizable monomers containing unsaturated carboxylic acid in the presence of (iv) an alkyl mercaptan of 6-18C atoms, in (C) an aqueous medium.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a curable aqueous resin dispersion, and more specifically, it exhibits good storage stability, and when water is splashed to form a film, the emulsifier and the emulsion polymerized resin undergo a crosslinking reaction. In particular, it relates to a curable aqueous resin dispersion that can form a transparent cured film with excellent water resistance. (Prior art) Aqueous resin dispersions have conventionally been produced by emulsion polymerization using various emulsifiers. It has a wide range of applications, including adhesives, paper processing agents, fiber processing agents, and mortar modifiers. However, the hydrophilic emulsifier used in emulsion polymerization remains in the film even after water is dispersed to form a film, and moreover, it tends to be localized at particle interfaces, which has a negative impact on various physical properties such as water resistance of the film. This is the cause of In order to improve the essential drawbacks of such aqueous resin dispersions, we have developed methods such as the Sor F7 emulsion polymerization method using a large amount of potassium persulfate, the emulsion polymerization method using a polymeric emulsifier, and polymerizable unsaturated groups and molecules. Emulsion polymerization methods using reactive emulsifiers have been proposed, but they are still insufficient in terms of water resistance. On the other hand, attempts have been made to improve the solvent resistance and strength of coatings by various crosslinking reactions. The most widely used method is to use a functional monomer such as N-methylol (meth)acrylamide or N-butoxymethyl (meth)acrylamide as a copolymerization component; The aqueous resin dispersions generally have poor stability and also have the problem of generating formalin during the process of forming a crosslinked film. (Problems to be Solved by the Invention) The present invention solves the above-mentioned problems that conventional aqueous resin dispersions have, and therefore, its purpose is to provide an aqueous dispersion that is extremely stable and yet The object of the present invention is to provide a curable aqueous resin dispersion that hardens without emitting harmful substances such as formalin when forming a film, and provides a film with excellent water resistance, solvent resistance, and strength. (Means and effects for solving the problem) As a result of intensive research, the present inventors have discovered that a polymer having a terminal alkyl group obtained by a specific method is used as an emulsifier to improve the polymerizability of specific components. The present inventors have discovered that a curable aqueous resin dispersion obtained by emulsion polymerization of monomers can achieve the above object, and have completed the present invention. That is, the present invention provides a monomer component (4) containing an unsaturated carboxylic acid as an essential component, which is obtained by polymerizing the polymerizable monomer component (4) in the presence of an alkyl mercaptan (B) having 6 to 18 carbon atoms, and which has an acid value of 200 or more. Polymer [I] having a water-soluble or water-dispersible terminal alkyl group and/or a salt thereof is used as an emulsifier to form a polymerizable monomer (a) containing a group reactive with a carboxyl group (a) 0 .5 to 40% by weight and other polymerizable monomers (b) 60 to 99.5% by weight (however, the total of polymerizable monomers (a) and (b) is 100% by weight!
It is Ik. The present invention relates to a curable aqueous resin dispersion obtained by emulsion polymerizing a polymerizable monomer component (II) consisting of the following in an aqueous medium. The polymer CD used as the emulsifier in the present invention is obtained by the above-mentioned procedure, but in terms of stability during emulsion polymerization and physical properties of the resulting resin film such as water resistance, solvent resistance, and strength, The acid value must be 200 or higher. The molecular weight is preferably in the range of 300 to 7,000, particularly 400 to 4,000. If a polymer having a molecular weight outside this range is used, sufficient emulsion stability may not be obtained, or a resin film having excellent water resistance, solvent resistance, and strength may not be obtained. The unsaturated carboxylic acid used in the synthesis of polymer [■] is polymer [! ] is used to impart hydrophilicity by introducing a carboxyl group into the curable resin, and to use it as a functional group when curing the resulting curable resin. It is not particularly limited as long as it has a polymerizable unsaturated group, such as (meth)acrylic acid,
Examples include crotonic acid, maleic acid, fumaric acid, itaconic acid, half esters thereof, or salts thereof,
It can be used alone or in combination with two or more of these. The polymerizable monomer component (4) when synthesizing the polymer (1) may be composed only of an unsaturated carboxylic acid, but if necessary, a polymerizable monomer other than the saturated carboxylic acid may be used in combination. You may. The polymerizable monomer that can be used is not particularly limited as long as it is copolymerizable with unsaturated carboxylic acid.
For example, styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, chloromethylstyrene, styrenesulfonic acid and its salts; (meth)acrylamide,
N-monomethyl (meth)acrylamide, N-monoether (meth)acrylamide, N,N-dimethyl (meth)
(Meth)acrylamide 9 derivatives such as acrylamide; by esterification of (meth)acrylic acid such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate with C1-C,8O alcohol. Synthesized (meth)acrylic esters; 2-hydroxyethyl (meth)acrylate, 2-(meth)acrylate
Hydroxyl group-containing (meth)acrylic esters such as hydroxypropyl, monoester of (meth)acrylic acid and polypropylene glycol or polyethylene glycol; ethyl (meth)acrylate 2-sulfonate and its salts, vinylsulfonic acid and its salt, vinyl acetate, (meth)acrylonitrile, etc.
One or a mixture of two or more of these can be used. Polymerizable monomers other than unsaturated carboxylic acids are used in the resulting polymer [
(2)] is used in an amount that does not result in an acid value of less than 200. Further, it is preferable to select the plugs and the amount thereof in consideration of compatibility with the polymer component generated when emulsion polymerization is performed using the obtained polymer (1). Examples of these include n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, cetyl mercaptan, stearyl mercaptan, etc.
Mixtures of more than one species can be used. (among alkyl mercaptans) is used to introduce an alkyl group to the end of the polymer [■] to impart surfactant ability, and alkyl mercaptans with less than 6 carbon atoms are used for stability during emulsion polymerization and for storage. Unable to use due to stability. The amount of alkyl mercaptan 0) to be used is determined depending on the molecular weight of the desired polymer [1), but usually the amount of the polymerizable monomer component (
A) It is used in an amount of 2 to 300 parts by weight per 100 parts by weight. The polymerization initiator used for polymerizing the polymerizable monomer component (A) is
Well-known oil-soluble and water-soluble polymerization initiators can be used, but in order to efficiently produce the polymer (1) having a terminal alkyl group, the amount used is alkyl mercaptan (B) 1
The ratio is preferably 1 mol or less, more preferably 0.1 mol or less, based on -E-. Depending on its properties, the polymer (1) can undergo bulk polymerization, solution polymerization,
It can be produced by any method of suspension polymerization. The polymerization temperature is preferably 50 to 150°C, and the polymerization time is preferably 1 to 8 hours. As a solvent for solution polymerization, the polymerizable monomer component (A
), alkyl mercaptan (B), and any radical polymerization initiator can be used as long as it dissolves and does not inhibit radical polymerization. Polymer [I] itself has sufficient surface-active ability, but in order to obtain a curable aqueous resin dispersion with good stability during polymerization and storage stability when used in emulsion polymerization, it is necessary to add carboxyl. Neutralize some or all of the groups to form a polymer [!
] It is preferable to use it as a salt. Is it a normal neutralizing agent? Can be used, for example, alkali metal compounds such as sodium hydroxide, potassium hydroxide; alkaline earth metal compounds such as calcium hydroxide, calcium carbonate; ammonia; monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine , monopropylamine, dimethylpropylamine, monoethanolamine, jetanolamine, triethanolamine, ethylenediamine, diethylenetriamine, etc., and one type or a mixture of two or more types selected from these groups. can be used. If it is desired to further improve the water resistance of the cured film, it is preferable to use low-boiling amines such as ammonia, monomethylamine, dimethylamine, trimethylamine, etc., which scatter at room temperature or upon heating. Polymerizable monomers having an I-oxy group such as glycidyl chloride, 2-methylglycidyl (meth)acrylate, and allylglycidyl ether used in the production of the curable aqueous resin dispersion of the present invention: (meth)acryloyl aziridine , aziridinyl group-containing polymerizable monomers such as 2-aziridinylethyl (meth)acrylate; oxazoline group-containing polymerizable monomers such as 2-ingropenyl-2-oxazoline, 2-vinyl-2-oxazoline, etc. You can list these 1 or 2 f! ! Mixtures of the above can be used. The amount of the polymerizable monomer (a) used is 0.5 to 40% by weight, preferably 3 to 15% by weight in the polymerizable monomer component (II) used for emulsion polymerization. If the amount of the polymerizable monomer (,) used is less than 0.5 weight, a large amount of xyl groups of the polymer [I] used as an emulsifier remain unreacted, and crosslinking becomes insufficient. No improvement was observed in water resistance, solvent resistance, or strength. On the other hand, if it exceeds 400 weight, the stability during emulsion polymerization and storage stability will deteriorate, which is not preferable. The polymerizable monomer (b) other than the polymerizable monomer (-) used in the emulsion polymerization of the present invention is not particularly limited as long as it is polymerizable, but one of them may be used depending on the purpose and use. One species or a combination of two or more species can be used. Examples of these polymerizable monomers include the polymerizable monomer component -W used in the synthesis of polymer [I] as is, dimethylamine ethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, etc. ) acrylamide, dimethylamine propyl (meth)acrylamide, vinylpyridine,
Basic unsaturated monomers such as vinyl imidazole and vinyl pyrrolidone; (meth)acrylic acid and ethylene glycol, 1,3-butylene glycol, diethylene glycol, 1,6-hexane glycol, neopentyl glycol, polyethylene glycol, polypropylene Polyfunctional (meth)acrylic acid esters having two or more polymerizable unsaturated groups in the molecule, such as esters with polyhydric alcohols such as glycol, trimethylolpropane, pentaerythritol, and dipentaerythritol; (Meth)acrylamides such as meth)acrylamide and N-butoxymethyl(meth)acrylamide; vinyltrimethoxysilane, γ-(meth)acryloxyglobiltrimethoxysilane, allyltriethoxysilane, trimethoxysilylglopyru unsaturated monomers containing a silicon group such as polyamine; and vinyl fluoride, vinylidene fluoride, vinyl chloride, vinylidene chloride, divinylbenzene, sialyl phthalate, and the like. The present invention provides a method for preparing a polymerizable monomer component (If) consisting of a polymerizable monomer (-) and other polymerizable premature body color in an aqueous medium using the polymer CII and/or its salt as an emulsifier. This invention relates to a curable resin dispersion obtained by emulsion polymerization, and any conventionally known emulsion polymerization method can be applied to the polymerization method. For example, a method in which a polymerization catalyst, water, the polymer [I] and/or its salt, a polymerizable monomer component [■] containing a polymerizable monomer (,) is mixed all at once, or a so-called monomer dropwise addition method is used. The curable aqueous resin dispersion of the present invention can be prepared by a method such as a pre-emulsion method or a pre-emulsion method. Can be synthesized. The polymerization temperature is 0 to 100°C, preferably 50 to 80°C, and the polymerization time is 1 to 10 hours. During emulsion polymerization, it is possible to add a hydrophilic solvent and other known emulsifiers and additives as long as the physical properties of the mixture are not adversely affected. The amount of polymer [I] and/or its salt used is 0.5 to 20 parts by weight per 100 parts by weight of the polymerizable monomer component (if).
The range of 0 double J accent is preferable, more preferably 1 to 15
Parts by weight. If the amount used is less than 0.5 parts by weight, emulsion polymerization stability will be poor, and if more than 200 parts by weight is used, gluing will occur during polymerization, resulting in poor burn stability. As the polymerization catalyst, any conventionally known catalyst can be used. However, in order to obtain a curable resin dispersion that provides a film with even better water resistance, hydrogen peroxide, di-t-butyl oxide, peracetic acid, 2,2'-azobis(2-amidinopronopronobase), etc. dihydrochloric acid [,4,4'
-A mixture of one or more polymerization catalysts that do not leave sulfate groups, such as azobis(4-cyanopencunic acid)? It is preferable to use More preferably, the polymerizable monomer (a)
2,2'-azobis(2-ami dinopropane) dihydrochloride, 4,4'-azobis(4- Cyanopentanoic acid) etc. ・The amount of polymerization catalyst used is usually 10% of the polymerizable monomer component (II).
The amount is in the range of 0.01 to 5 parts by weight relative to 0 parts by weight. During emulsion polymerization, the polymerizable monomer component [II] is converted into a polymerizable monomer component (II) containing one or more types of polymerizable monomers (,).
-a) and the polymerizable monomer component CII-b: which does not contain one or more of the polymerizable monomers (IL), and carry out multi-stage polymerization of all of them. The curable aqueous resin dispersion is preferred because the water resistance, solvent resistance, and strength of the coating film are particularly markedly improved. At that time, the polymerizable monomer component (I
The emulsion polymerization of I-a:) and the polymerizable monomer component [II-b''l may be carried out in several stages, and the order of polymerization does not matter. However, if the polymerizable monomer component cm-b:+ is used as the component to be polymerized in the last stage, it is difficult to improve the above physical properties of the cured film. It is preferable because it dramatically improves the storage stability.The curable aqueous resin dispersion produced as described above is
It self-crosslinks at room temperature or when heated, making it water resistant.
It forms a high-strength cured film with good solvent resistance, but if necessary, aminoplast resin, polyfunctional block isocyanate, epoxy resin, pigment, antifoaming agent, film-forming aid, etc. may be added. be able to. (Effects of the Invention) The curable aqueous resin dispersion of the present invention is obtained by radical polymerizing a polymerizable monomer component containing an unsaturated carboxylic acid) in the presence of an alkyl mercaptan (B) having 6 to 18 carbon atoms. Using the obtained polymer [I] as an emulsifier, a polymerizable monomer consisting of a polymerizable monomer (a) containing a group having reactivity with a carboxyl group and another polymerizable monomer ('b) Ingredients [I
I) is emulsion polymerized in an aqueous medium and t i! It has good storage stability, and when water is splashed, the emulsifier diffuses into the emulsion polymerized resin and reacts with the hydrophilic carboxyl group, forming a crosslinked structure without generating formalin. Because of its formation, it provides a coating with extremely excellent physical properties such as water resistance, solvent resistance, and strength. Therefore, this curable aqueous resin dispersion is useful in a wide range of applications such as paints, adhesives, paper processing agents, fiber processing agents, and mortar modifiers, especially in fields where water resistance and solvent resistance are required. It is. (One Example) The present invention will be described in detail below with reference to Examples, but the scope of the present invention is not limited only to these Examples. In addition, unless otherwise specified in the examples, Q is weight% gold,
Each part indicates a part by weight. Reference Example 1 180 parts of isopropyl alcohol was placed in a flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, and while blowing nitrogen, the internal temperature was raised to 81°C, and the isopropyl alcohol was refluxed for 10 minutes. I let it happen. Next, a previously prepared polymerizable monomer mixture consisting of 174 parts of acrylic acid, 36 parts of n-dodecylmercaptan, and 0.42 parts of 2,2'-azobisisobutyronitrile was added over 1 hour. It was added dropwise and polymerized. After the dropwise addition was completed, it was aged for 1 hour under reflux to obtain a polymer with a solid content of 53.9% (1
) was obtained. The polymer (1) has a structure represented by the following general formula? has an acid value of 645 and a number average molecular weight of 12.
00 white powder. Reference Example 2 A flask similar to Reference Example 1 was charged with 180 parts of isopropyl alcohol, and the internal temperature was raised to 81° C. while blowing nitrogen, and the isopropyl alcohol was refluxed for 10 minutes. Next, from 86 parts of acrylic acid, 139 parts of 2-hydroxyethyl acrylate, 36 parts of n-dodecylmercaptan, 30 parts of isopropyl alcohol, and 0.30 parts of 2,2'-azobisinbutyronitrile prepared in advance. The polymerizable monomer mixture vlJ was added dropwise over 1 hour and polymerized. After completion of the dropwise addition, the solution was aged under reflux for 1 hour to obtain a solution of polymer (2) with a solid content of 55.4%. The polymer (
2) has a structure represented by the following general formula, and has an acid value of 2
It was a white viscous substance with a number average molecular weight of 1,500. Comparative Reference Example 1 A flask similar to Reference Example 1 was charged with 180 parts of isopropyl alcohol, and the internal temperature was raised to 81° C. while blowing nitrogen, and the isopropyl alcohol was refluxed for 10 minutes. Next, 10 parts of acrylic acid, 20 parts of 2-hydroxyethyl methacrylate, 40 parts of methyl methacrylate, 20 parts of n-butyl acrylate, 10 parts of styrene, and 2,2'-azobisisobutyro which had been prepared in advance were added. A polymerizable monomer mixture consisting of 4 parts of nitrile was added dropwise over 3 hours.
Polymerized. After the addition was completed, the mixture was aged for 1 hour under reflux.
A solution of comparative polymer (1') with a solid content of 52.9% was obtained. The polymer (1') has an acid value of °38 and a number average molecular weight of i7.
500 white resinous material. Comparative Reference Example 2 In a flask similar to Reference Example 1, 180 parts of inpropyl alcohol was charged, and while blowing nitrogen, the internal temperature was raised to 81° C., and the isopropyl alcohol was refluxed for 10 minutes. Subsequently, 86 parts of acrylic acid, 139 parts of 2-hydroxyethyl acrylate, 14 parts of thioglycol, and 0 of 2,2'-azobisisobutyronitrile, which had been prepared in advance, were added.
．． Polymerizable monomer mixture #4 consisting of 30 parts! = was added dropwise over 1 hour to polymerize. After completion of the dropwise addition, aging was carried out for 1 hour under reflux to obtain a comparative polymer (two solutions) with a solid content of 56.9%. The polymer (2') had a structure represented by the following general formula. It was a white viscous substance with an acid value of 280 and a number average molecular weight of 11,400. Example 1 A flask equipped with a dropping funnel, a stirrer, a nitrogen inlet tube, a thermometer, and a reflux condenser was charged with 150 parts of pure water and a boiling water bottle. was heated to 65°C while blowing nitrogen gas into the solution.A polymerizable monomer mixture consisting of 55 parts of butyl acinate, 35 parts of methyl methacrylate, and 10 parts of glycidyl methacrylate was prepared in a dropping funnel, and 10 parts of the mixture was added to the dropping funnel. Then, 4 parts of a 5% aqueous solution of 2,2'-azobis(2-amidinogulonone) dihydrochloride was injected into the flask.After 10 minutes, the remaining polymerizable monomer mixture was added dropwise. The dropwise addition was completed in 1.5 hours.During the dropwise addition, the temperature was maintained at 65-70°C, and after the dropwise addition was completed, the polymerization was completed by stirring at the same temperature for 1 hour. A curable aqueous resin dispersion [1] with pH = 8.3 was obtained.The amount and type of neutralizing agent and the type of polymerizable monomer mixture were adjusted to
Is the operation the same as in Example 1 except for the procedures shown in the table? il
-Repeatedly to obtain curable aqueous resin dispersions [2] to [5]. The results are summarized in Table 1. Example 6 The same procedure as in Example 1 was carried out, except that the same amount of a 5% aqueous solution of potassium persulfate was used instead of the 5% aqueous solution of 2,2'-azobis(2-amisononoro/4'-en) dihydrochloride. Example 1
The same operation as above was repeated to obtain a curable aqueous resin dispersion [6]. The results are shown in Table 1. Comparative Example 1 In Example I, Cal? 55 parts of butyl acrylate, 4 parts of methyl methacrylate, which does not contain the polymerizable monomer (a) [glycityl methacrylate] that has reactivity with xyl groups.
A comparative aqueous resin dispersion was prepared by repeating the same operation as in Example 1, except that 5 parts of the polymerizable monomer mixture was used.
1′] was obtained. The results are shown in Table 1. Comparative Examples 2 to 3 Comparative aqueous resin dispersions were prepared by repeating the same operations as in Example 1, except that a commercially available emulsifier was used instead of the ammonia-neutralized product of polymer (1) as the emulsifier. liquid〔
2'] to [3'] were obtained. The results are summarized in Table 1. Comparative Example 4 In Example I, the same amount of the solution of the comparative polymer (1') was used instead of the solution of the polymer (1), and 0.18 part of dimethylethanolamine was used instead of the 28 thiammonia water. Emulsion polymerization was carried out by repeating the same procedure except for the following steps. However, in the latter half of the dropping process, a large amount of aggregates formed, making it impossible to continue the polymerization. Comparative Example 5 In Example 1, 35 parts of a solution of comparative polymer (1') was used instead of the solution of polymer (1), and 1.12 parts of dimethylethanolamine was used instead of 28% ammonia water. The same procedure was repeated except that the amount of polymerizable monomer used was the same as shown in Table 1 to prepare a comparative aqueous resin dispersion [5].
′] was obtained. The results are shown in Table 1. Comparative Example 6 The same operation as in Example 1 was carried out except that the same amount of comparative green polymer (2') solution and 1.6 parts of 28 thiammonia water were used instead of the polymer (1) solution. Emulsion polymerization was carried out repeatedly. However, in the latter half of the dropping process, a large amount of aggregates formed, making it impossible to continue the polymerization. Comparative Example 7 Emulsion polymerization was carried out by repeating the same procedure as in Example 1 except that a mixture of 55 parts of butyl acrylate and 45 parts of glycidyl methacrylate was used as the polymerizable monomer mixture. However, in the latter half of the dropping process, a large amount of aggregates formed, making it impossible to continue the polymerization. Example 7 In a flask similar to Example 1, 150 parts of pure water and 5.6 parts of the solution of polymer (2) obtained in Reference Example 1 were charged to give a 28%
2.1 parts of aqueous ammonia was added to neutralize the mixture. The mixture was heated to 65° C. while being gently bubbled with nitrogen gas. Add 20 parts of butyl acrylate and 1 part of glycidyl methacrylate to the dropping funnel.
A polymerizable monomer mixture (a) consisting of 0 parts of polymerizable monomers (polymerizable monomer mixture containing IL-1) was prepared, and 10 parts of it was added dropwise to the flask. Then 2.2'
- 4 parts of an aqueous solution of azobis(2-amidinoglopane) dihydrochloride was injected. After 10 minutes, dropwise addition of the remaining polymerizable monomer mixture [A] was started, and the dropwise addition was completely completed in 20 minutes. After continuing stirring for 30 minutes, as the second stage polymerization, a polymerizable monomer mixture containing no polymerizable monomers* consisting of 35 parts of butyl acrylate and 35 parts of methyl methacrylate was prepared in the dropping funnel. The mixture was added dropwise over 1 hour. During the polymerization, the temperature was maintained at 65 to 70°C, and after the completion of the second stage addition, stirring was continued at the same temperature for 1 hour to complete the polymerization. A curable aqueous resin dispersion [7] was obtained. Examples 8 to 9) In the same manner as in Example 7, a polymerizable monomer mixture [A] containing a polymerizable monomer substance was polymerized, and then polymerization was carried out as the second stage (A) polymerization. A curable aqueous resin dispersion [8] ~

[9] was obtained. The results are summarized in Table 2. Comparative Examples 8 to 9 In the same manner as in Example 7, polymerizable monomer mixtures [A], [
A comparative aqueous resin dispersion was prepared by repeating the same operation as in Example 7, except that the type and amount of the resin were as shown in Table 2.
8'] to [9'] were obtained. The results are summarized in Table 2. Example 10 Curable aqueous resin dispersion [1] obtained in Examples 1 to 9 and Comparative Examples 1 to 9

[9], Comparative aqueous resin dispersion i (1
'E~C9']e Film thickness when drying on Teflon plate is 0, 2
Cast to ~0.3 fins and heat at 20°C.
A film was formed by drying in the sun, and then heated at 120° C. for 3 minutes to prepare a test film. The following performance tests were conducted on the obtained films to evaluate the performance of each aqueous resin dispersion. As a result <CL> Significant improvements in water resistance, solvent resistance, and strength (a) were observed that were not observed in systems in which the polymer (1) or the polymerizable monomer moiety was used alone. Further, after emulsion polymerization of a polymerizable monomer mixture containing a polymerizable monomer part, (A) emulsification of a polymerizable monomer mixture not containing a polymerizable monomer part as a second stage polymerization. The polymerized system had a rating of 1, and the water resistance test film had a rating of 20. I cut it into a corner and weighed it (We)
. The film was immersed in deionized water for 3 days, pulled out, and the moisture on the film surface was gently wiped off before being weighed (W!)
. The film was further dried at 100° C. for 1 hour, left to cool, and then pressed (W,). Calculate the water absorption rate and dissolution rate using the formula below and check the water resistance of the test film. evaluated. Film appearance: The transparency of the film immersed in deionized water for 3 days was evaluated. ○: No change as it remains transparent Δ: Becomes pale ×: Whitening 2. Solvent resistance test The film was cut into 20-square pieces and immersed in 50° C. methyl cellosolve for 15 minutes. Thereafter, the film was taken out and the area swelling rate was measured. Furthermore, after the test, the film was dried and the dissolution rate was calculated. 3. Film strength The tensile strength of the film was measured based on the test method described in JIS K-6732. 4. Storage-stable curable aqueous resin dispersion (1-50°C, change in minimum film-forming temperature before and after standing for 30 days゛○...No change at all. △...0°C to 5°C Changed within the range of ×... Changed by 5°C or more.

Claims (1)

[Claims] 1. An acid value obtained by polymerizing a polymerizable monomer component (A) containing an unsaturated carboxylic acid as an essential component in the presence of an alkyl mercaptan having 6 to 18 carbon atoms (B) Using a polymer [I] having a water-soluble or water-dispersible terminal alkyl group of 200 or more and/or a salt thereof as an emulsifier,
0.5 to 40% by weight of a polymerizable monomer (a) containing a group having reactivity with a carboxyl group and 60 to 99.5% by weight of another polymerizable monomer (b) (however, polymerizable Monomer (
The sum of a) and (b) is 100% by weight. ) A curable aqueous resin dispersion obtained by emulsion polymerization of a polymerizable monomer component [II] consisting of ) in an aqueous medium. 2. Polymerizable monomer component [II] is a polymerizable monomer containing a group having reactivity with one or more carboxyl groups (a
) and a polymerizable monomer component [II-b] that does not contain one or more of the polymerizable monomers (a).
Claim 1, in which the invention is divided into two parts, and these are polymerized in multiple stages.
The curable aqueous resin dispersion described in . 3. The curable aqueous resin dispersion according to claim 2, wherein the component polymerized at least in the last stage is a polymerizable monomer component [II-b].