JP3327036B2 - Method for producing curable emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a curable Emarujo down excellent storage stability and coating film properties having a hydrolyzable alkoxysilyl group.

[0002]

2. Description of the Related Art Conventionally, curable copolymers having a hydrolyzable silyl group represented by an alkoxysilyl group have been widely used for applications such as adhesives, sealing materials, paints and coating agents. However, in these application fields, in order to avoid harm to the human body and environmental pollution due to volatilization of the organic solvent, an aqueous material not using an organic solvent is required, and a curable copolymer having an alkoxysilyl group is required. The need for aqueous emulsification has also increased for coalescence.

[0003] A curable copolymer having an alkoxysilyl group is originally not easily obtained in the form of a stable aqueous emulsion because it has a property of crosslinking while hydrolyzing. For this reason, various attempts have been made to secure an aqueous emulsion having excellent storage stability. For example, Japanese Unexamined Patent Publication (Kokai) No. 3-227212 discloses that the above-mentioned monomer is used for the purpose of stabilizing the obtained curable copolymer when an aqueous emulsion polymerization of a monomer having an alkyl (meth) acrylate and an alkoxysilyl group is carried out. A method has been proposed in which a specific water-soluble monomer such as acrylamide, acrylic acid or styrenesulfonic acid is used in an amount of about 0.1 to 5% by weight in addition to the monomer to copolymerize the monomer. Also, Japanese Unexamined Patent Application Publication No.
No. 54 proposes a method of copolymerizing a monomer having a hydrolyzable silyl group with a monomer having an amine imide group in an alcohol solvent, adding water to emulsify, and further evaporating the alcohol. Have been. In addition, JP-A-59-152972 discloses a silane-based synthetic resin emulsion coating composition having excellent water resistance, obtained by emulsion polymerization of vinylsilane and an acrylic monomer using a polymerizable emulsifier. There is disclosed a composition in which a specific amount of colloidal silica is blended with an aqueous emulsion containing a copolymer having a glass transition point of 70 ° C. or lower.

On the other hand, as an emulsifier, anionic surfactants such as alkyl sulfates, alkylbenzene sulfates, polyoxyethylene alkyl ether sulfates, sodium dodecylbenzenebenzenesulfonate and the like, polyoxyethylene alkyl ethers and polyoxyethylene alkyls have been used. Nonionic surfactants such as phenyl ether, polyoxyethylene fatty acid ester, and allonic surfactant have been used. As an alternative emulsifier for reactive emulsion polymerization, JP-A-62-104802 discloses the following. Wherein A is an alkylene group having 2 to 4 carbon atoms, R1 is a carbon atom or methyl group, R2 is a hydrocarbon group or an acyl group having 8 to 24 carbon atoms, and m is 0 to 0.
The number 50 and X is a hydrogen atom or a nonionic or anionic hydrophilic group) are disclosed.

[0005]

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[0006] Similarly, Japanese Patent Application Laid-Open No. 4-53802 discloses a compound represented by the following general formula (2) (wherein R1 has 6 to 6 carbon atoms).
18 alkyl groups, alkenyl groups or aralkyl groups, R2 is hydrogen or an alkyl group having 6 to 18 carbon atoms, alkenyl groups or aralkyl groups, R3 is hydrogen or a propenyl group, A is an alkylene group having 2 to 4 carbon atoms or substituted alkylene. The group, n is an integer from 1 to 200, M is an alkali metal, ammonium ion or alkanolamine residue).

[0007]

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[0008]

However, the self-curing aqueous emulsion of the alkoxysilyl system according to the prior art has insufficient storage stability and does not provide satisfactory coating film properties when used in paints and the like. There were still issues to be improved.

The present inventors have made intensive studies to obtain a curable emulsion in which a polymer of a monomer having an alkoxysilyl group is dispersed in an aqueous medium and has excellent storage stability. It has been discovered that, when an anionic or cationic radical polymerizable surfactant having an alkylene group is copolymerized with the above monomer in a specific method, excellent storage stability and coating film properties that are unexpectedly superior are imparted. As a result, the present invention was developed.

Accordingly, an object of the present invention is to provide a curable copolymer having a hydrolyzable alkoxysilyl group, yet having excellent storage stability and imparting high-quality coating film properties. and to provide a <br/> industrial production process of the curable Emarujo emissions of aqueous systems.

[0011]

SUMMARY OF THE INVENTION A production method for obtaining a curable emulsion according to the present invention for achieving the above object.
The method is represented by the general formula: Z- (AO) n-Y (where Z is
AO is a structural unit having a cal polymerizable double bond,
A alkylene group, n is an integer of 2 or more, and Y is an ion dissociable group.
The radical polymerizable surfactant (c) represented by
Lac having an alkoxysilyl group in the presence of a pH buffer
Dical polymerizable monomer (a), a copolymer copolymerizable with the monomer (a)
Dical polymerizable monomer (b) and oil-soluble radical polymerization initiation
Step [A] of emulsifying and dispersing the agent in an aqueous medium, and step [A]
Drop the aqueous emulsified dispersion obtained in step 2 into a heated aqueous medium.
The radical polymerizable monomer (a)
Compatible monomer (b) and the radical polymerizable surfactant
(c) is sequentially performed in the step (B) of copolymerizing
Is what you do.

[0012]

Hereinafter, the composition of the curable emulsion according to the present invention and the production method thereof will be described in more detail. To the present invention
The curable copolymer obtained is a radical polymerizable monomer (a) having an alkoxysilyl group, a radical polymerizable monomer (b) copolymerizable with the monomer (a), and a specific hydrophilic polymer. It is a polymer obtained by copolymerizing a radically polymerizable surfactant (c) having a functional group. Among these radical monomers, the alkoxy component of the monomer (a) includes, for example, methoxy group, ethoxy group, propoxy group, butoxy group, pentanoxy group,
Hexanoxy groups and the like are mentioned, and the number of carbon atoms is not particularly limited. However, alkoxy having a higher number of carbon atoms than a pentanoxy group has low reactivity except when a catalyst such as an acid catalyst is added. Therefore, an alkoxysilyl group having a lower number of carbon atoms than a butoxy group is preferable. Considering that the methoxy group has a somewhat insufficient stability and the butoxy group is not highly reactive, an ethoxy group or a propoxy group is more preferable. The number of alkoxy groups bonded to a silicon atom may be any number as long as it is in the range of 1 to 3, but two or three are preferable because one reduces the curability. Specifically, vinyl triethoxy silane, vinyl methyl diethoxy silane, γ-methacryloxy propyl triethoxy silane, γ-methacryloxy propyl methyl diethoxy silane, vinyl tripropoxy silane, vinyl methyl dipropoxy silane, γ-methacryloxy Propyltripropoxysilane, γ-methacryloxypropylmethyldipropoxysilane and the like can be mentioned.

As the monomer (b), methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Alkyl (meth) acrylates such as lauryl (meth) acrylate and stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, perfluoroalkyl (meth) acrylate Glycidyl (meth) acrylate, (meth) acrylic acid N,
(Meth) acrylates such as N-diethylaminoethyl, vinyl acetate, vinyl propionate, styrene,
α-methylstyrene and the like. Among these, preferred monomers from the viewpoints of copolymerizability and coating film properties include alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms, styrene, and alkylene groups having 2 to 3 carbon atoms. Hydroxyalkyl (meth) acrylate, glycidyl methacrylate, and the like. But (meta)
Monomers having reactive or hydrolyzable enhancing the an alkoxy silyl group such as acrylic acid are not preferred.

The surfactant as the component (c) has a chemical formula: Z
-(AO) n-Y (wherein Z is a structural unit having a radical polymerizable double bond, AO is an oxyalkylene group, and n is 2
The above integer, Y represents an ion-dissociable group) is an anionic or cationic radically polymerizable surfactant. Preferred Z in the above-mentioned chemical formula; Z- (AO) n-Y is a radical polymerizable group such as a hydrophobic group such as an aromatic hydrocarbon group, an alkyl-substituted aromatic hydrocarbon group, a higher alkyl group or an alicyclic hydrocarbon group. It has a structure in which a heavy bond is combined. As the radical polymerizable double bond for Z, a (meth) allyl group, a propenyl group, a butenyl group, or the like is preferable.

The preferred ionicity of the surfactant (c) in the present invention is an anion. Therefore, as Y, a salt in which an anion is covalently bonded to the group (AO) n side and a cation is ionically bonded thereto is preferable. Specific examples of the preferred _{Y, -SO 3 Na, -SO 3} NH 4, -COON
_{a, -COONH 4, -PO 3 Na} 2 , and -PO
₃ (NH ₄ ) _{2 and the} like, more preferably —SO ₃
Na or -SO ₃ is NH _4. N in the group (AO) n is preferably 300 or less, more preferably 5 to 50. When n is less than 5, the monomer
The stability of the alkoxysilyl group in (a) tends to be insufficient, while when n exceeds 50, the physical properties of the coating film formed from the curable emulsion obtained tend to decrease. The unit A in the group (AO) n, that is, the alkylene group is preferably an ethylene group or a propylene group.

Specific examples of the component (c) include, for example, compounds represented by the following chemical formulas 3, 4 and 5.
As R in Chemical formula 3 or Chemical formula 4, a linear or branched alkyl group having 6 to 18 carbon atoms is preferable. R2 in Chemical Formula 5 is preferably an alkyl group having 8 to 24 carbon atoms.
Is a hydrogen atom or a methyl group. Also, from Chemical Formula 3 to Chemical Formula 5
Specific examples of Y in the above are as described above.

[0018]

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[0019]

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[0020]

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The pH buffer contained in the curable emulsion obtained in the present invention is adjusted to a pH range of the aqueous medium in the aqueous emulsified dispersion in a neutral to weakly alkaline region, specifically pH6.
Those having a buffer function suitable for holding the pressure at 10 to 10 are preferably used. Examples of this type of pH buffer include sodium bicarbonate, potassium bicarbonate, monosodium phosphate, monopotassium phosphate, disodium phosphate, trisodium phosphate, sodium acetate, ammonium acetate and sodium formate. It is preferable to use sodium hydrogen carbonate whose pH is stabilized by addition of a small amount.
The compounds can be used in combination of two or more kinds. For example, by using sodium hydrogen carbonate and monosodium phosphate in combination, the pH can be maintained at around 7.5. A suitable amount of the pH buffer is 0.01 to 5% by weight based on water.
Range. The use of a pH buffering agent, pH of the aqueous medium in the aqueous emulsion dispersion is controlled in the range of 6-10, the radical polymerization monomer having a an alkoxy silyl group
(a) Alternatively, hydrolysis of an alkoxysilyl group in a polymer containing the monomer as a component is suppressed. Note that p
A weak alkali compound such as ammonia, monoethylamine, triethylamine or ethanolamine may be used as a pH adjuster together with the H buffer if necessary.

The step [A] for producing the curable emulsion having the above-mentioned composition comprises a radically polymerizable surfactant
This is a process in which the radical polymerizable monomers (a) and (b) and the oil-soluble radical polymerization initiator are emulsified and dispersed in an aqueous medium in the presence of (c) and a pH buffer. Specifically, a pH buffer is dissolved in an aqueous medium containing a surfactant (c), and a mixed solution comprising monomers (a), (b) and an oil-soluble radical polymerization initiator is added dropwise to this solution. Or aqueous emulsification by dropping a solution in which a monomer, a polymerization initiator and a surfactant (c) are mixed into an aqueous medium in which a pH buffer is dissolved.

The proportions of the monomers (a) and (b) and the surfactant (c) are determined based on the total amount of (a) component 3
The component (b) is preferably 96.5 to 75% by weight, and the component (c) is preferably 0.5 to 20% by weight. The ratio of the aqueous medium containing the pH buffer to the monomer solution to be emulsified is preferably set to 20 to 150 parts by weight of the aqueous medium per 100 parts by weight of the monomer.

As the oil-soluble radical polymerization initiator, those having a solubility in water at 20 ° C. of 10% by weight or less are preferably used. For example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4 dimethylvaleronitrile, 1-azobis-1-cyclohexanecarbonitrile and dimethyl-2,2'-azobisisobutyrate Azo initiators, organic peroxides such as lauroyl peroxide, benzoyl peroxide, dicumyl peroxide, cyclohexanone peroxide di-n-propylperoxydicarbonate and t-butylperoxypivalate are preferably used. . The amount of these polymerization initiators,
The amount is suitably from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, based on the total amount of the monomers.

The method of emulsification and dispersion in the step [A] is not particularly limited, and can be sufficiently emulsified and dispersed by a usual rotary homomixer. However, radical polymerizable monomers
If the particle size of the emulsified dispersion comprising (a), (b) and the surfactant (c) is large, the particle size of the emulsified dispersion after polymerization is also large, so that the aqueous emulsion having the smallest possible particle size is used. It is preferably a dispersion. The preferred particle size of the aqueous emulsified dispersion is specifically 1 μm or less, more preferably 0.1 μm or less.
2 to 0.05μ. Therefore, the particle diameter is reduced by using a dispersing device having a high shear energy, such as a high-pressure emulsifying disperser (homogenizer) or a turbine type mixer, after processing by a rotary homomixer instead of or after a normal rotary homomixer. It is desirable.

Then, the aqueous emulsified dispersion obtained in the step [A] is dropped into an aqueous medium heated to a temperature not lower than the decomposition temperature of the polymerization initiator, and the monomers (a) and (b) and the surfactant Agent (c)
[B] is copolymerized. The polymerization in the present invention,
Since the oil-soluble radical polymerization initiator is contained in the dispersed particles of the monomer solution, it occurs in each dispersed fine particle. Such a polymerization method is generally called a microsuspension polymerization method, and is distinguished from an emulsion polymerization method in which polymerization is carried out by a water-soluble initiator in micelles formed by an emulsifier.

The polymerization operation is carried out by a method in which an aqueous emulsion dispersion (hereinafter referred to as "monomer emulsion") is continuously or intermittently fed into an aqueous medium heated under stirring. As a method of supplying the monomer emulsion, it is preferable to employ a means of gradually dropping from a dropping funnel. At this time, the preferred amount of the aqueous medium charged into the polymerization vessel is in the range of 10 to 50 parts by weight per 100 parts by weight of the monomer emulsion. The polymerization temperature varies depending on the polymerization initiator used, but is usually about 40 to 100 ° C, preferably 70 to 100 ° C.
９０90 ° C.

By the copolymerization step [B], a curable emulsion in which polymer particles having an average particle size of about 0.1 μm are stably emulsified and dispersed is produced. The curable emulsion was heated at a temperature of 60 as described in the examples.
Even when left at ℃ for one month, it maintains a stable emulsion state and also has good self-curing performance.

The curable emulsion of the present invention obtained by the above aqueous microsuspension polymerization is cured by a condensation reaction mainly caused by silanol groups generated by hydrolysis of alkoxysilylsilyl groups derived from the monomer (a). I do. As a curing catalyst, for example, organic titanate compounds such as isopropyl triisostearoyl titanate and isopropyl tri (dioctyl pyrophosphate) titanate, or tin dioctylate, dibutyltin dilaurate,
An organic tin compound such as dibutyltin malate or an organic acid catalyst such as paratoluenesulfonic acid can be used. In addition, when the emulsion of the present invention is used together with the curing catalyst, an appropriate amount of an inorganic acid is added to adjust the pH of the emulsion to an acidic range of about 3 to 5 to produce a film having further improved crosslinkability. Becomes possible.

The curable emulsion of the present invention is suitable as a coating agent. Specifically, for example, a coating material for building materials, such as glass, slate, metal, wood, or plastic, an acid rain-resistant paint, and an antifouling paint , Water repellent for inorganic building materials,
It can be used as a moisture-proof coating agent for electric / electronic parts, a back coating agent for magnetic tapes, a hardening finish agent for fibers, a water repellent, a sealing agent, an adhesive, a binder, an adhesive, and the like.

[0031]

The curable emulsion obtained according to the present invention comprises:
(a) A radical polymerizable monomer having an alkoxysilyl group and (b) a radical polymerizable monomer copolymerizable with the monomer (a) are represented by a general formula Z- (AO) n-Y (formula Wherein Z is a structural unit having a radical polymerizable double bond, AO is an oxyalkylene group, n is an integer of 2 or more, and Y is an ion dissociable group. It is composed of a composition containing a polymerized curable copolymer as a main component. Copolymerization by a specific method combining a monomer having an alkoxysilyl group and an anionic or cationic radically polymerizable surfactant having an ion-dissociable group with the polyoxyalkylene group. Sometimes a surfactant not only functions as an emulsifier, but also radically polymerizes and comes close to a monomer having an alkoxysilyl group, and the alkoxysilyl group can be effectively protected by a polyoxyalkylene group. Significantly enhances storage stability.

According to the production method of the present invention, a radical polymerizable surfactant having a polyoxyalkylene group and a monomer having an alkoxysilyl group in the presence of a pH buffer are used to initiate oil-soluble radical polymerization. By taking a process of emulsifying and dispersing the agent in an aqueous medium and then copolymerizing, the copolymerization proceeds as microsuspension polymerization occurring in each fine particle dispersed in the aqueous medium. Therefore, an emulsion state in which the dispersion is always stabilized can be obtained.

[0033]

The present invention will be described more specifically below with reference to examples and comparative examples. In addition, all the parts of the component blend in each example are parts by weight. Among the surfactants used in the examples, “AQUALON” (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) is a compound represented by Chemical Formula 6, and “Adekari RIP” [Asahi Denka Kogyo Co., Ltd.] Is a compound represented by Chemical formula 7. Aqualon HS05, HS10, and HS20 correspond to those having a polyoxyethylene group condensation degree n of Chemical Formula 6 of 5, 10, or 20, respectively. It is 10.

[0034]

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[0035]

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Example 1 (1) Step [A]: The radical polymerizable monomers (a) and (b), the surfactant (c), the oil-soluble radical polymerization initiator and the aqueous medium are shown in Table 1. After mixing with a homomixer, the mixture was further emulsified and dispersed with a homogenizer (manufactured by Gorin) to prepare a monomer emulsion having a pH of 8.5.

[0037]

[Table 1]

(2) Step [B]: A flask equipped with a stirrer, a thermometer and a cooler is charged with 40 parts of deionized water as an aqueous medium, the liquid temperature is raised to 85 ° C., and the aqueous medium is The above monomer emulsion was added dropwise over 2 hours while stirring with. After the completion of the dropwise addition, the mixture was kept at a temperature of 85 ° C. for 2 hours for copolymerization, and then cooled to room temperature. During the polymerization, aggregates slightly adhered to the inner wall of the flask, but liquid separation and blocking did not occur, and the polymerization was stably performed. By this polymerization operation, a curable emulsion having a solid content of 40% by weight, an average particle size of the polymer particles of 0.11 μm, and a pH of 8.5 was obtained.

(3) Characteristic evaluation: The cured emulsion after filtration was evaluated by the following method, and the results are shown in Table 2. Amount of grit The amount of non-passed material when the curable emulsion was filtered through a 200 mesh net was defined as the grid content. Emulsion stability Place curable emulsion in sealed container at 60 ° C for 1 month
, The amount of alcohol generated by decomposition of the alkoxysilyl group [hydrolysis ratio (%)] was analyzed by gas chromatography to confirm the degree of stability. Further, it was evaluated whether the elasticity of the physical properties of the coating film formed from the curable emulsion was changed as compared with the initial stage. Elasticity is measured by bending the dried coating film in half and then bending it in the opposite direction.
Judgment was made based on the state after repeated times. Coating physical properties The curable emulsion was applied to a release paper and dried at room temperature for 10 days to prepare a coating having a thickness of about 1 mm.
For the water resistance, the transparency after immersing the dried coating film in water at room temperature for 7 days was evaluated (○: transparency maintained, Δ: slightly whitened, ×: completely whitened). It was immersed in acetone at room temperature for one day, and the weight after that was measured and evaluated as a ratio to the initial weight [gel fraction (%)].

Example 2 A curable emulsion was produced under the same conditions as in Example 1 except that the monomer (a) was replaced by methacryloxypropylmethyldiethoxysilane, and the other conditions of polymerization and polymerization were all the same.
The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 3 The amount of the monomer (a) methacryloxypropyltriethoxysilane in Example 1 was changed to 20 parts, and the amount of n-butyl acrylate in the monomer (b) was changed to 20 parts. A curable emulsion was produced under the same conditions as in Example 1 except for the composition and the polymerization procedure. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 4 The amount of the monomer (a) of Example 1 was changed to 4 parts of methacryloxypropyltriethoxysilane, and the amount of n-butyl acrylate of the monomer (b) was changed to 36 parts. A curable emulsion was produced under the same conditions as in Example 1 except for the composition and the polymerization procedure. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 5 The surfactant (c) was replaced with "Adekaria Soap SE-10N" (manufactured by Asahi Denka Kogyo Co., Ltd.), and all other compositions and polymerization procedures were carried out under the same conditions as in Example 1 under curability. An emulsion was prepared. The resulting curable emulsion was prepared according to Example 1
Table 2 also shows the results of the characteristic evaluation performed in the same manner as described above.

Example 6 A curable emulsion was produced under the same conditions as in Example 1 except that the surfactant (c) was changed to "AQUALON HS10" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). did. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 7 A curable emulsion was prepared according to the same conditions as in Example 1 except that the surfactant (c) was replaced by "AQUALON HS05" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). did. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 8 Example 1 was repeated except that the monomer (a) was replaced with methacryloxypropyltrimethoxysilane, and all other compositions and polymerization operations were performed.
A curable emulsion was produced under the same conditions as described above. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 9 A curable emulsion was produced under the same conditions as in Example 1 except that the monomer (a) was replaced by methacryloxypropyltripropoxysilane, and the other conditions were the same as in Example 1. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 10 The procedure of Example 1 was repeated except that the monomer (a) was replaced with methacryloxypropyltributoxysilane, and all other compositions and polymerization operations were carried out.
A curable emulsion was produced under the same conditions as described above. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Example 11 A curable emulsion was produced under the same conditions as in Example 1 except that the monomer (a) was replaced with methacryloxypropyltripentanoxysilane, and all other compositions and polymerization procedures were the same. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 1 Polymerization initiator 2, a monomer emulsion was prepared without using 2′-azobisisobutyronitrile, and the monomer emulsion was added as a polymerization initiator to the aqueous medium to be dropped. One part of ammonium persulfate was added. Also, adjust the pH buffer amount to 1
Department. When the polymerization operation was performed under the same conditions as in Example 1 for all other compositions, the kettle liquid started to gel and solidify during the dropping of the monomer emulsion, and the polymerization had to be interrupted.

Comparative Example 2 A polyoxyethylene alkyl phenyl ether sulfate ("Levenol WZ", manufactured by Kao Corporation) was used as a surfactant instead of "Aqualon HS-20". A curable emulsion was produced under the same conditions as in Example 1 except for all other compositions and polymerization operations. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2. In this example, the water resistance of the curable emulsion was reduced.

Comparative Example 3 Polymerization was carried out under the same conditions as in Example 1 except that no pH buffer was used. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2. In this case, about 5% of the theoretical amount of ethanol was detected from the end of the polymerization, and it was confirmed that the ethanol was further decomposed during the stability test to increase the amount of ethanol generated. Further, the dried film formed from the emulsion after the stability test was very brittle as compared with the dried film prepared from the emulsion immediately after the synthesis.

Comparative Example 4 Surfactant (c) Instead of "Aqualon HS-20",
5 parts of a monomer of the sodium alkenylsuccinate type represented by the following general formula (“Latemul S180A” manufactured by Kao Corporation) was blended. All other compositions and polymerization procedures were as in Example 1.
A curable emulsion was produced under the same conditions as described above. The properties of the obtained curable emulsion were evaluated in the same manner as in Example 1, and the results are shown in Table 2. In this example, a large amount of grid was generated, and the stability of the obtained curable emulsion was extremely poor. The cause is “Latemul S180A”
Of the surfactant (c) of the present invention has the chemical structure (O
A) An ionic group (Y), which does not have an n moiety
, The alkoxysilyl group is easily hydrolyzed.

[0054]

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[0055]

[Table 2]

[0056]

As described above, according to the present invention, a combination of radical-polymerizable surfactant carrying monomer and a polyoxyalkylene group having an alkoxysilyl group, according to the present invention especially
By performing copolymerization by a constant method, it is possible to provide a self-curing aqueous emulsion that provides excellent storage stability and high-quality coating film properties. Therefore, it is extremely useful for various uses such as paints, adhesives, sealing agents, and coating agents.

Claims (1)

(57) [Claims] 1. A compound represented by the general formula: Z- (AO) n-Y, wherein Z
Is a structural unit having a radical polymerizable double bond, and AO is
A xyalkylene group, n is an integer of 2 or more, and Y is ion dissociation
Radical polymerizable surfactant (c)
And an alkoxysilyl group in the presence of a pH buffer
Radically polymerizable monomers (a), the monomer (a) and copolymerization Yes
[A] for emulsifying and dispersing a functional radical polymerizable monomer (b) and an oil-soluble radical polymerization initiator in an aqueous medium; and heating the aqueous emulsified dispersion obtained in the step [A] in an aqueous medium. the radical polymerizable monomer was dropped into (a), the radio
Method for producing a curable emulsions characterized by comprising local polymerizable monomer (b) and the radical polymerizable surfactant (c) from Step [B] to be copolymerized.