JP2005336436A - High durability emulsion and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of aggregates in the production of a highly durable emulsion having excellent weather resistance, stain resistance, water resistance and crack resistance and excellent polymerization stability, and industrial To provide a manufacturing method with a small equipment load and a small number of processing steps.
SOLUTION: A hydrolyzable silane [C] is mixed with a pre-emulsion liquid comprising a radical polymerizable monomer [A], a silicone oligomer [B], a polymerization initiator [E] and an emulsifier [D], and then an aqueous solution. A method for producing a highly durable emulsion, comprising polymerizing in a medium.
[Selection figure] None

Description

  The present invention is highly durable capable of forming a coating film excellent in stain resistance, flexibility, water resistance, weather resistance, durability, pigment dispersibility, gloss retention, adhesion, rust resistance, and water resistance. It relates to an acrylic emulsion. Specifically, it is useful as a finishing material for paints, building materials, surface treatments or finishing materials, adhesives, paper processing agents, woven fabrics, and non-woven fabrics, and in particular, concrete, cement mortar, slate plates, calcium plates, plaster. Main materials and tops for multi-layer finishing coating materials as paints or building finishing materials for various substrates such as boards, extruded plates, inorganic building materials such as expandable concrete, building materials based on woven or non-woven fabric, and metal building materials The present invention relates to a highly durable emulsion useful as a metal paint, a wood paint, and a tile paint as a synthetic resin emulsion paint such as a coat, a thin finish paint, a thick finish paint, a stone finish finish, and a gloss paint.

Water-based emulsions obtained by emulsion polymerization are often used as resins for water-based paints because the film formed by drying at room temperature or under heating exhibits relatively good durability. In such a case, there is a problem of deterioration such as loss of gloss, discoloration, and swelling. Therefore, when long-term durability is required, solvent-based paints such as solvent-based acrylic silicone resins have been used (for example, Patent Document 1). However, with the recent emphasis on environmental hygiene, work safety, and low odor, the advent of highly durable water-based paints that can replace these solvent-based paints has become eager.
The inventors of the present application previously used an ethylenically unsaturated monomer having a sulfonic acid group, a sulfonate group, or a sulfate ester group as an emulsifier, as disclosed in Patent Document 2, Patent Document 3, and Patent Document 4. A highly durable acrylic emulsion has been proposed which is modified with a silicone using a modifier having a specific silicone structure that imparts improved water resistance. And this new emulsion has the durability improved significantly compared with the conventional acrylic emulsion.

However, in order to further improve the durability performance, there is a technique for increasing the amount of silicone modification by alkoxylane, polyalkoxysiloxane, alkoxysilyl group-containing monomer, etc., but polyalkoxysiloxane is generally used for emulsification. In polymerization, stability in an aqueous medium is insufficient, and it was difficult to introduce into emulsion particles by emulsion polymerization. For example, Patent Document 5 discloses a method in which an aqueous solution containing polydimethylsiloxane is emulsified with a high-pressure homogenizer, and Patent Document 6 discloses a method in which an aqueous solution containing polyalkoxypolysiloxane is emulsified with a high-pressure homogenizer. A method is disclosed.
In order to improve the standing stability of the emulsion, the weather resistance of the coating film, etc., in Patent Document 7, polyalkoxypolysiloxane is reacted with a compound having a functional group capable of reacting with the polyalkoxypolysiloxane. A method is disclosed in which a compound is obtained and then reacted with a silicone oligomer and a radical polymerizable monomer to obtain a composition.

Patent Document 8 discloses a production method in which a mixture containing an organosilane (hydrolyzable silane) and a radical polymerizable monomer is hydrolyzed / condensed and radically polymerized in an emulsified state. After mixing silane (hydrolyzable silane), radical polymerizable monomer and hydrolysis catalyst, proceeding with hydrolysis in the emulsified state, the emulsion particle size is reduced to 0.5μm or less, and radical polymerization is started. A manufacturing method for radical polymerization by adding an agent is disclosed.
However, polycondensation in a system in which a large amount of a hydrolyzable silane compound, polyalkoxypolysiloxane, etc. is added to the radical polymerizable monomer is a large amount of alcohol from the alkoxy group of the hydrolyzable silane compound and polyalkoxypolysiloxane. Is produced as a by-product, and the emulsion is broken or easily broken. In the method in which the mixed liquid in such a state is introduced into an aqueous medium and emulsion polymerization is performed, many aggregates are easily generated in the emulsion, and countermeasures are required. For this reason, after performing polycondensation of the hydrolyzable silane compound once, a distillation treatment for removing the alcohol is performed, and further, a plurality of treatment steps are obtained by polymerizing with the radical polymerizable monomer to obtain the target emulsion resin. It was not easy.

In addition to the radically polymerizable monomer and the hydrolyzable silane compound, the method of emulsifying the hydrolyzable catalyst all at once, the hydrolysis proceeds rapidly, and the heat of hydrolysis generated in the emulsion causes There is a risk that the polymerization initiator dissociates and the reaction proceeds in the emulsion, so that a step of adding the polymerization initiator after cooling the emulsion is necessary. Therefore, industrially, a cooling facility against the heat of hydrolysis is essential, and in addition to the treatment of the by-product alcohol, the load on the industrial facility is increased, and an additional step of adding a polymerization initiator is also required.
In addition, the polyalkoxypolysiloxane that can reduce the amount of by-product alcohol and heat of hydrolysis and the method of reacting a silicate oligomer with the compound can increase the silicone component, but the silicone component becomes a block polymer and is not microscopically uniform. It becomes.
In addition to countermeasures for by-product alcohol, polycondensation in a system in which a large amount of a hydrolyzable silane compound, polyalkoxypolysiloxane, etc. is added, the silanol groups generated by hydrolysis of the alkoxy groups are not completely condensed. Some of them remain in the latex particles and in the aqueous phase, resulting in a problem that storage stability and mechanical stability are lowered.

Japanese Patent Application Laid-Open No. 07-026155 Japanese Patent Laid-Open No. 08-003409 International Publication No. WO95-29196 Pamphlet JP-A-10-120724 Japanese Patent Laid-Open No. 05-194911 JP 2000-053919 A JP 2001-172340 A JP 2001-302920 A JP 2002-226507 A

  The present invention can form a coating film excellent in weather resistance, stain resistance, water resistance and crack resistance, and can suppress the generation of aggregates in the production of a highly durable emulsion excellent in polymerization stability. It is an object of the present invention to provide a production method with a small equipment load and a small number of processing steps.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the first of the present invention is that a hydrolyzable silane [C] is added to a pre-emulsion liquid comprising a radical polymerizable monomer [A], a silicone oligomer [B], a polymerization initiator [E] and an emulsifier [D]. And then polymerizing in an aqueous medium.
In the second aspect of the invention, the pre-emulsion comprises a solution obtained by mixing and dissolving the radical polymerizable monomer [A] and the silicone oligomer [B], an aqueous medium, a polymerization initiator [E], and an emulsifier [D]. A method for producing a highly durable emulsion according to the first aspect of the invention.
A third aspect of the invention is the first aspect of the invention or the second aspect of the invention, wherein the hydrolyzable silane [C] is polymerized in an aqueous medium while continuously or intermittently mixed with the pre-emulsion. This is a method for producing a highly durable emulsion.
A fourth aspect of the present invention is the method for producing a highly durable emulsion according to any one of the first to third aspects, wherein the pH of the pre-emulsion is 4.0 or less.

A fifth aspect of the invention is the method for producing a highly durable emulsion according to any one of the first to fourth aspects, wherein the oil droplet diameter of the pre-emulsion liquid is 1.0 μm or less.
A sixth aspect of the invention is a condensate of a hydrolyzable silane compound in which the silicone oligomer [B] is represented by the following formula (a), and the amount of alkoxy groups per molecule of the silicone oligomer [B] is 0.1-50. %. The method for producing a highly durable emulsion according to any one of the first to fifth aspects of the invention.
(R ¹ ) _n —Si— (R ² ) _4-n (a)
(In the formula, n is an integer of 0 to 3, and each R ¹ is independently hydrogen, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, or 5 to 5 carbon atoms. 6 cycloalkyl groups, a vinyl group, a phenyl group, an alkyl acrylate group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently selected from 1 to 1 carbon atoms. 8 is selected from an alkoxy group, an acetoxy group, a hydroxyl group, an epoxy group, an ethylene oxide group, or a halogen atom, and at least one is an alkoxy group.)

A seventh aspect of the invention is that the silicone oligomer [B] is represented by the following formulas (1), (2) and (3), and the amount of alkoxy groups per molecule of the silicone oligomer [B] is 0.1 to 50%. It is a manufacturing method of the highly durable emulsion as described in any one of 1st-6th of the invention characterized by the above-mentioned.

（式中、各Ｒ¹ はそれぞれ、独立して水素、炭素数１〜１６の脂肪族炭化水素基、炭素数５〜１０のアリール基、炭素数５〜６のシクロアルキル基、ビニル基、炭素数１〜１０のアクリル酸アルキル基又は炭素数１〜１０のメタクリル酸アルキル基から選ばれ、各Ｒ² はそれぞれ、独立して炭素数１〜８のアルコキシ基、アセトキシ基、水酸基、エポキシ基又はエチレンオキサイド基から選ばれ、少なくとも１つはアルコキシ基である。ｍは１〜９９９の正の整数を表す。）

(In the formula, each R ¹ is independently hydrogen, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, a vinyl group, or carbon. Selected from an alkyl acrylate group having 1 to 10 carbon atoms or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, a hydroxyl group, an epoxy group, or (Selected from ethylene oxide group, at least one is an alkoxy group. M represents a positive integer of 1 to 999.)

According to an eighth aspect of the invention, the mass ratio of the silicone oligomer [B] to the total mass of the silicone oligomer [B] and the hydrolyzable silane compound [C] is 5% to 95%. It is a manufacturing method of the highly durable emulsion as described in any one of -7.
A ninth aspect of the invention is that the radically polymerizable monomer [A] is 5% by mass or more selected from the group consisting of (meth) acrylate monomers having a cycloalkyl group. It is a manufacturing method of the highly durable emulsion as described in any one of 1st-8th of the invention characterized by consisting of a body.
A tenth aspect of the present invention is a highly durable emulsion obtained by the production method according to any one of the first to ninth aspects of the present invention.

  The emulsion production method of the present invention is a simple and industrial facility that suppresses the generation of aggregates and is less likely to produce a stable product than the production method in which the polymerization stability decreases when the conventional silicone component is increased. A manufacturing method with a small load can be provided. The emulsion production method of the present invention can provide an aqueous silicone-modified acrylate polymer emulsion capable of forming a coating film excellent in weather resistance, stain resistance, water resistance and crack resistance.

Hereinafter, the present invention will be described in detail.
Radical polymerizable monomer [A]
The radical polymerizable monomer [A] in the present invention is represented by (meth) acrylic acid ester (in this application, acrylic acid and methacrylic acid are collectively referred to as (meth) acrylic acid). It is necessary to include an acrylate monomer. Specific examples of (meth) acrylic acid esters include (meth) acrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl moiety, and (poly) oxyethylene mono (meth) having 1 to 100 ethylene oxide groups. Acrylate, (poly) oxypropylene mono (meth) acrylate, (meth) acrylic acid hydroxyalkyl ester having 1 to 18 carbon atoms in the alkyl portion, and (poly) oxyethylene di (1) having 1 to 100 ethylene oxide groups And (meth) acrylate. Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic acid t-. Examples include butyl, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, and (meth) acrylic acid cycloalkyl ester. Specific examples of (poly) oxyethylene mono (meth) acrylate include ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, diethylene glycol methoxy (meth) acrylate, (meta ) Tetraethylene glycol acrylate, tetraethylene glycol methoxy (meth) acrylate, and the like. Specific examples of (poly) oxypropylene mono (meth) acrylate include propylene glycol (meth) acrylate, propylene glycol methoxy (meth) acrylate, dipropylene glycol (meth) acrylate, dipropylene methoxy (meth) acrylate Examples include glycol, tetrapropylene glycol (meth) acrylate, and tetrapropylene glycol methoxy (meth) acrylate. Specific examples of the (meth) acrylic acid hydroxyalkyl ester include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. Specific examples of (poly) oxyethylene di (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and di (meth) acryl. Examples include acid tetraethylene glycol. Specific examples other than the above include glycidyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, and the like. The (meth) acrylate monomer is preferably used in an amount of 80 to 100 mass%, more preferably 90 to 100 mass%, based on the mass of the radical polymerizable monomer [A]. Furthermore, in the present invention, the monomer that can be used as a radical polymerizable monomer [A] mixed with a (meth) acrylate monomer includes a radical polymerizable carboxylic acid monomer, an acrylamide monomer, and methacrylamide. Examples thereof include at least one comonomer that can be copolymerized with a (meth) acrylate monomer selected from monomers and vinyl monomers. Preferably, it is a radically polymerizable carboxylic acid monomer and is at least one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid and monoesters thereof, fumaric acid and monoesters thereof, and maleic acid and monoesters thereof. It is particularly preferred that This is because these radical polymerizable carboxylic acid monomers also act as a catalyst for promoting the hydrolysis reaction and condensation reaction of the hydrolyzable silane. Examples of acrylamide monomers or methacrylamide monomers include (meth) acrylamide, diacetone (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and vinyl monomers. Examples thereof include vinyl acetate, vinyl propionate, vinyl versatate, vinyl pyrrolidone, methyl vinyl ketone, and examples of vinyl cyanide monomers include acrylonitrile and methacrylonitrile. Furthermore, as a monomer that can be used as a radical polymerizable monomer [A] by mixing with a (meth) acrylate monomer, aromatic monomers such as vinyltoluene, styrene, α-methylstyrene, vinyl chloride, Examples thereof include vinyl halides such as vinylidene chloride, butadiene, and ethylene.

  In the present invention, it is preferable to include a (meth) acrylate monomer having a cycloalkyl group as the radical polymerizable monomer [A] because it is particularly excellent in durability. A part of hydrogen atoms of the cycloalkyl group may be substituted with an alkyl group having 1 to 6 carbon atoms, a hydroxyl group or an epoxy group. 5% by mass or more, more preferably 5% by mass or more and 99% by mass or less, more preferably 5% by mass or more and 80% by mass or less of the radical polymerizable monomer [A] has a cycloalkyl group. It is preferably a monomer or a mixture thereof. A (meth) acrylate monomer having a cycloalkyl group or a mixture thereof is excellent in durability when it is 5% by mass or more of the radical polymerizable monomer [A], and has good film formability when it is 80% by mass or less. Examples of the (meth) acrylate monomer having a cycloalkyl group include (meth) acrylic acid cycloalkyl ester. As the (meth) acrylic acid cycloalkyl ester, an ester of a cycloalkyl group having 5 to 12 carbon atoms is preferable, and the cycloalkyl ester is an alkyl group in which a part of hydrogen atoms of the cycloalkyl group has 1 to 6 carbon atoms, It may be substituted with a hydroxyl group or an epoxy group. Examples of the (meth) acrylate monomer having a cycloalkyl group include a compound represented by the following formula (4).

（式中、Ｒ¹ は水素原子またはメチル基であり、Ｒ² はシクロペンチル基、シクロヘキシル基又はシクロドデシル基であり、これらシクロアルキル基は、炭素数１〜６のアルキル基、水酸基またはエポキシ基を置換基として有してもよい。）
その具体例としては、（メタ）アクリル酸シクロヘキシル、（メタ）アクリル酸２−ヒドロキシシクロヘキシル、（メタ）アクリル酸メチルシクロヘキシル、（メタ）アクリル酸２，３シクロヘキセンオキサイドなどを挙げることができる。

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a cyclopentyl group, a cyclohexyl group or a cyclododecyl group, and these cycloalkyl groups are alkyl groups, hydroxyl groups or epoxy groups having 1 to 6 carbon atoms. (You may have it as a substituent.)
Specific examples thereof include cyclohexyl (meth) acrylate, 2-hydroxycyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, 2,3 cyclohexene oxide (meth) acrylate, and the like.

Silicone oligomer [B]
The silicone oligomer [B] used in the present invention is not particularly limited as long as it is a hydrolyzable silane condensate represented by the following formula (a).
(R ¹ ) _n —Si— (R ² ) _4-n (a)
(In the formula, each R ¹ is independently hydrogen, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, a vinyl group, or phenyl. Group, an alkyl acrylate group having 1 to 10 carbon atoms or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, a hydroxyl group, (It is selected from an epoxy group, an ethylene oxide group or a halogen atom, and at least one is an alkoxy group.)

More preferable silicone oligomer [B] used in the present invention is represented by the following formulas (1), (2) and (3).

（式中Ｒ¹ は水素、炭素数１〜１６の脂肪族炭化水素基、炭素数５〜１０のアリール基、炭素数５〜６のシクロアルキル基、ビニル基、炭素数１〜１０のアクリル酸アルキル基又は炭素数１〜１０のメタクリル酸アルキル基から選ばれ、各Ｒ² はそれぞれ、独立して炭素数１〜８のアルコキシ基、アセトキシ基、水酸基、エポキシ基又はエチレンオキサイド基から選ばれ、少なくとも１つはアルコキシ基である。ｍは１〜９９９の正の整数を表す。）

(In the formula, R ¹ is hydrogen, an aliphatic hydrocarbon group having ^{1 to} 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, a vinyl group, and an acrylic acid having 1 to 10 carbon atoms. Each selected from an alkyl group or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, a hydroxyl group, an epoxy group, or an ethylene oxide group, (At least one is an alkoxy group. M represents a positive integer of 1 to 999.)

Further, the silicone oligomer may be linear or have a branched structure, and preferable m is 2 to 50, more preferably 2 to 20 which increases dispersibility in the aqueous phase. The amount of alkoxy groups in the silicone oligomer is preferably 2 to 50%, more preferably 2 to 30%. When the amount is 50% or more, a large amount of alcohol is generated as a by-product, and the polymerization stability is impaired. The degree of crosslinking of the components decreases, and the contribution to improving weather resistance decreases. Commercially available silicone oligomers may be used, or compounds obtained by hydrolytic condensation of hydrolyzable silane compounds may be used. In this case, alcohol removal treatment that inhibits polymerization stability is used. Is required.
Specific examples of commercially available silicone oligomers include methyl methoxy groups such as KC-89, KR-500, X-40-9225, X-40-9246, and X-40-9250, and phenyl such as KR-217. Methyl group such as methoxy group, KR-9218, KR213, KR510, X-40-9227, X-40-9247, etc. (named product name manufactured by Shin-Etsu Chemical Co., Ltd.) and methylmethoxy type such as MSE-100 (above silicone) The product name) manufactured by Wacker Co., etc. can be used, and these silicone oligomers can be used alone or in combination.

In the production method of the present invention, a hydrolyzable silane [C] was mixed with a pre-emulsion liquid comprising a radical polymerizable monomer [A], a silicone oligomer [B], a polymerization initiator [E] and an emulsifier [D]. Thereafter, a highly durable emulsion can be obtained by polymerization in an aqueous medium.
Examples of the polymerization method include emulsion polymerization, suspension polymerization, bulk polymerization, and miniemulsion polymerization. As a method for stably producing an emulsion having an average particle size of about 10 nm to 1 μm and excellent dispersion stability, emulsification is possible. Polymerization is preferred.
Furthermore, in the production method of the present invention, it is important to prepare a solution obtained by mixing and dissolving the radical polymerizable monomer [A] and the silicone oligomer [B] before emulsification.

  When radically polymerizable monomer [A] and silicone oligomer [B], emulsifier [D], polymerization initiator [E], and aqueous medium are mixed and emulsified with a homomixer or the like, the radical polymerizable monomer Monomer oil droplets with a high body concentration and silicone oligomer concentrations are high, and oil droplets with a particle diameter of 20 μm or more are generated. As a result, emulsion particles having a micro-uniform composition are formed, and further, formed into a film. The resulting coating also has a microscopically non-uniform structure. In addition, when the molecular weight of the silicone oligomer is large or when the addition amount is large, the composition becomes more non-uniform and a large amount of aggregates are generated during the polymerization. In order to suppress microscopic heterogeneity between the radically polymerizable monomer [A] and the silicone oligomer [B] and to obtain a uniform structure, in the production method of the present invention, the radically polymerizable monomer [A] It is important to obtain a solution in which the solution is mixed and dissolved before emulsifying the silicone oligomer [B]. In this solution, the silicone oligomer [B] is uniformly compatible with the radical polymerizable monomer [A], and hydrolysis does not proceed. The solution, aqueous medium, radical polymerizable carboxylic acid monomer [A], polymerization initiator [E] and emulsifier [D] are added and emulsified with a homomixer or the like to obtain a pre-emulsion. In this pre-emulsion, since the radical polymerizable carboxylic acid monomer [A] acts as a hydrolysis catalyst, hydrolysis of the silicone oligomer [B] proceeds. However, as the silicone oligomer [B] used in the present invention, the amount of alkoxy groups of the silicone oligomer is preferably 2 to 50%, more preferably 2 to 30% in terms of suppressing the heat of hydrolysis, and hydrolysis of 50% or more. The amount of heat cannot be suppressed, and a large amount of by-produced alcohol is generated, so that the polymerization stability is impaired. Moreover, as a silicone oligomer [B], the methyl alkoxy oligomer and methyl phenyl alkoxy oligomer which melt | dissolve in a radically polymerizable monomer [A] are preferable, and a methyl phenyl alkoxy oligomer with high compatibility is more preferable. Further, it is more preferable to promote uniform microscopic concentration by emulsifying into fine oil droplets having a particle diameter of 1 μm or less using a high-pressure homogenizer having a high shearing force.

Hydrolyzable silane compound [C]
In the present invention, it is preferable to use a hydrolyzable silane compound in order to impart a crosslinking density and flexibility of the silicone structure. The hydrolyzable silane compound [C] preferably contains at least one silane (I) having a silicone structure represented by the following formula (a).
_{^{(R 1) n -Si- (R}} 2) 4-n (a)
(In the formula, n is an integer of 0 to 3, and each R ¹ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, or a cycloalkyl having 5 to 6 carbon atoms. Selected from a group, a vinyl group, a phenyl group, an alkyl acrylate group having 1 to 10 carbon atoms, or an alkyl methacrylate group having 1 to 10 carbon atoms, and n R ^{1 s} may be the same or different. Each R ² is selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group or a hydroxyl group, and 4-n R ² may be the same or different.

In particular, the hydrolyzable silane compound [C] preferably contains at least one silane (II) having n = 1 in the formula (a). As R ¹ of silane (II), a methyl group, a phenyl group, a vinyl group, and a γ- (meth) acryloxypropyl group are preferable, and R ² each independently represents a methoxy group, an ethoxy group, a propoxy group, a butoxy group, A methoxyethoxy group and a hydroxyl group are preferred. Preferable specific examples of silane (II) include methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, isobutyltrimethoxysilane, vinylethoxysilane, γ-acryloxypropyltrimethoxysilane, There are γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, and the like, and two or more of these may be included.

  In the present invention, the hydrolyzable silane compound [C] preferably contains at least one selected from the group consisting of cyclic silane and silane (III) obtained by setting n = 2 in the formula (a). This is because the use of the silane (III) and / or cyclic silane lowers the crosslink density of the silicone polymer formed by the silane compound [C] and prevents the polymer structure from becoming complicated. This is because flexibility can be imparted to the coating film provided from the highly durable emulsion. Specific examples of silane (III) include dimethyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, methylphenylsilane, and γ-methacryloxypropylmethyldimethoxysilane. As the cyclic silane, octamethylcyclotetrasiloxane, octaphenylcyclosiloxane, hexamethylcyclotrisiloxane, decamethylcyclopentasiloxane, tetramethyltetravinylcyclotetrasiloxane, and the like can also be used.

In the hydrolyzable silane compound [C], when silane (II) alone has a problem in film flexibility, at least one selected from the group consisting of the above cyclic silanes and silane (III) is used in combination. It is preferable. The amount is preferably such that the molar ratio of silane (II) to at least one selected from the group consisting of the above cyclic silanes and silane (III) is from 100/1 to 10/100, and from 100/1 to 35. / 100 is more preferable. When the silane (II) is 10/100 or more, there is no problem in the polymerizability of the silane, and there is substantially no problem in the residual low molecular weight silane.
Further, the hydrolyzable silane compound [C] may contain at least one selected from the group consisting of silane (IV) obtained by setting n = 0 or 3 in the formula (a). In the hydrolyzable silane compound [C], when silane (II) alone has a problem in coating film flexibility, it is preferable to use at least one selected from the group consisting of silane (IV) in combination. The amount is preferably such that the molar ratio of silane (II) to at least one selected from the group consisting of silane (IV) is 100/1 to 10/100, and is 100/1 to 35/100. It is more preferable. When the silane (II) is 10/100 or more, there is no problem in the polymerizability of the silane, and there is substantially no problem in the residual low molecular weight silane.

Specific examples of silane (IV) include phenyltriethoxysilane, trimethylmethoxysilane, and tetraethoxysilane. In silane (III) or silane (IV), R ¹ is particularly preferably a methyl group or a phenyl group, and R ² is particularly preferably a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group or a hydroxyl group.
The hydrolyzable silane compound [C] is a chlorosilane such as methylchlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyl in addition to at least one compound selected from silane (III) or silane (IV). Trichlorosilane, diphenylchlorosilane, vinylchlorosilane, γ- (meth) acryloxypropyltrichlorosilane, and γ- (meth) acryloxypropyldichloromethylsilane can be included.

In the present invention, by using a hydrolyzable silane compound [C], it is possible to improve the gloss retention in a long-term exposure of a film obtained from a highly durable emulsion, for example, outdoors, and to obtain a film exhibiting high weather resistance for the first time. Can do. The presence of the above-mentioned silane condensate can be known by ²⁹ SiNMR ( ²⁹ Si nuclear magnetic resonance spectrum) or ¹ HNMR (proton nuclear magnetic resonance spectrum). For example, a condensate of silane (II) can be identified by 29SiNMR chemical shift showing a peak at -40 to -80PPM. Silane (IV) or condensate of cyclic silane can be identified by 29Si NMR chemical shift showing a peak at -16 to -26 PPM.

In the present invention, the radically polymerizable monomer [A], the silicone oligomer [B] and the hydrolyzable silane compound compound [C] are preferably used in a total amount of 100 parts by mass of the radically polymerizable monomer [A] component. On the other hand, the silicone oligomer [B] is 5 to 200 parts by mass, the weather resistance is improved at 5 parts by mass or more, the polymerization stability is good at 200 parts by mass or less, and the obtained coating film has sufficient elongation and cracks. It is hard to produce, More preferably, it is 5-100 mass parts. The hydrolyzable silane compound [C] is preferably 1 to 200 parts by mass, the weather resistance is improved at 1 part by mass or more, the polymerization stability is good at 200 parts by mass or less, more preferably 1 to 100 parts by mass, More preferably, it is 5-50 mass parts. When the amount is 50 parts by mass or less, a decrease in polymerization stability due to generation of by-product methanol is small.
Furthermore, in order to ensure the polymerization stability and to give the minimum film-forming temperature, crosslinking degree and flexibility of the resin obtained from the emulsion, it is excellent in weather resistance and hardly causes cracking, the silicone oligomer [B], and When the hydrolyzable silane compound [C] is used in combination, the mass ratio of the silicone oligomer [B] to the total mass of the silicone oligomer [B] and the hydrolyzable silane compound [C] is 5% to 95%. Preferably, if it is 5% or more, it is easy to impart the degree of crosslinking and flexibility with the hydrolyzable silane compound [C], and if it is 95% or less, the polymerization stability is excellent, and more preferably 5 to 80%.

Emulsifier [D]
In the present invention, the emulsifier [D] used for emulsion polymerization is at least one of an ethylenically unsaturated monomer having a sulfonic acid group or a sulfonate group and an ethylenically unsaturated monomer having a sulfate group. In order to achieve a high level of water resistance, it is preferable. The ethylenically unsaturated monomer having a sulfonic acid group or a sulfonate group mentioned here has a radically polymerizable double bond and is a free sulfonic acid group, or an ammonium salt or an alkali metal salt thereof. A compound having (ammonium sulfonate group or alkali metal sulfonate group) is preferable. For example, an alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 2 to 4 carbon atoms, a polycarbon having 2 to 4 carbon atoms, which is partially substituted with a group that is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group. It is a compound having a substituent selected from the group consisting of an alkyl ether group, an aryl group having 6 or 10 carbon atoms and a succinic acid group, or bonded to a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group. Preferred are vinyl sulfonate compounds having a vinyl group.

Specific examples of the succinic acid compound partially substituted with a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group in the present invention include allylsulfosuccinate, for example, the following formulas (5), (6), (7), the compound represented by (8) is mentioned.

Wherein R ¹ is hydrogen or a methyl group, R ² is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, or an aralkyl having 6 to 19 carbon atoms. A hydrocarbon group such as a group, or a group in which a part thereof is substituted with a hydroxyl group, a carboxylic acid group, or the like, or a polyoxyethylene alkyl ether group (wherein the alkyl moiety has 0 to 20 carbon atoms and the alkylene moiety has 2 to 2 carbon atoms) 4), an organic group containing an alkylene oxide compound such as a polyoxyalkylene alkylphenyl ether group (wherein the alkyl moiety has 0 to 20 carbon atoms and the alkylene moiety has 2 to 4 carbon atoms), and A is 2 to 2 carbon atoms. 4 alkylene groups or a partially substituted alkylene group, n is an integer from 0 to 200, and M is ammonium, sodium or potassium.)
Examples of those containing the above formulas (5) and (6) include Eleminol JS-2 and JS-5 (product names, manufactured by Sanyo Chemical Co., Ltd.), and those containing the above formulas (7) and (8). As, for example, there are Latemuru S-120, S-180A, S-180 (product name, manufactured by Kao Corporation).

（式中、Ｒ¹ は炭素数６〜１８のアルキル基、アルケニル基またはアラルキル基であり、Ｒ² は炭素数６〜１８のアルキル基、アルケニル基またはアラルキル基、Ｒ³ は水素またはプロペニル基、Ａは炭素数２〜４のアルキレン基、ｎは１〜２００の整数、Ｍはアンモニウム、ナトリウム、カリウムもしくはアルカノールアミン残基である。） In addition, as an example of a compound having a C2-C4 alkyl ether group or a C2-C4 polyalkyl ether group partially substituted with a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group And compounds represented by the following formulas (9) to (11).

Wherein R ¹ is an alkyl group, alkenyl group or aralkyl group having 6 to 18 carbon atoms, R ² is an alkyl group, alkenyl group or aralkyl group having 6 to 18 carbon atoms, R ³ is hydrogen or propenyl group, A is an alkylene group having 2 to 4 carbon atoms, n is an integer of 1 to 200, and M is an ammonium, sodium, potassium, or alkanolamine residue.)

（式中、Ｒ¹ は水素またはメチル基、Ｒ² は炭素数８〜２４のアルキル基またアシル基、Ａは炭素数２〜４のアルキレン基、ｎは０〜５０の整数、ｍは０〜２０の整数、Ｍはアンモニウム、ナトリウム、カリウムもしくはアルカノールアミン残基である。）

(Wherein R ¹ is hydrogen or a methyl group, R ² is an alkyl group or acyl group having 8 to 24 carbon atoms, A is an alkylene group having 2 to 4 carbon atoms, n is an integer of 0 to 50, and m is 0 to 0) An integer of 20, M is an ammonium, sodium, potassium or alkanolamine residue.)

（式中、Ｒ¹ は炭素数８〜３０のアルキル基、Ｒ² は水素またはメチル基、Ａは炭素数２〜４のアルキレン基、もしくは置換アルキレン基、ｎは０または、１〜２００の整数であり、Ｍはアンモニウム、ナトリウム、カリウムもしくはアルカノールアミン残基である。）

Wherein R ¹ is an alkyl group having 8 to 30 carbon atoms, R ² is hydrogen or a methyl group, A is an alkylene group having 2 to 4 carbon atoms, or a substituted alkylene group, n is 0 or an integer having 1 to 200 And M is an ammonium, sodium, potassium or alkanolamine residue.)

Examples of the alkylphenol ether compound represented by the above formula (9) include Aqualon HS-10 (product name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Examples of the compound represented by the above formula (10) include Examples of compounds represented by ADEKA rear soap SE-1025A, SR-10N, SR-20N (product names, manufactured by Asahi Denka Kogyo Co., Ltd.) and the above formula (11) include Aqualon KH-10 and KH-05. .
Other specific examples of the compound having an aryl group partially substituted with a sulfonate group include p-styrenesulfonic acid ammonium salt, sodium salt and potassium salt. Specific examples of the compound having an alkyl group partially substituted with a sulfonate group include ammonium salt, sodium salt and potassium salt of methylpropanesulfonic acid acrylamide, ammonium salt of acrylic acid sulfoalkyl ester, sodium salt and potassium salt, Ammonium salts, sodium salts and potassium salts of acrylic acid sulfoalkylesters can be mentioned.

Specific examples of the compound having a sulfonate group other than the above include vinyl sulfonate compounds having a vinyl group to which a group which is an ammonium salt, sodium salt or potassium salt of a sulfonic acid group is bonded.
The ethylenically unsaturated monomer having a sulfate ester group refers to a compound having a radical polymerizable double bond and a sulfate ester group or a group that is an ammonium salt or an alkali metal salt thereof. Among these, a C1-C20 alkyl group, a C2-C4 alkyl ether group, a C2-C2 partly substituted by the group which is an ammonium salt of a sulfate ester group, sodium salt, or potassium salt. A compound having a group selected from the group consisting of 4 polyalkyl ether groups and aryl groups having 6 or 10 carbon atoms is preferred. Examples of the compound having a C2-C4 alkyl ether group or a C2-C4 polyalkyl ether group partially substituted with an ammonium salt, sodium salt or potassium salt of a sulfate ester group include, for example, There are compounds represented by formulas (9) and (10) having an alkyl ether group partially substituted with a sulfonate group.

These ethylenically unsaturated monomers used as the emulsifier [D] exist in the emulsion as a copolymer obtained by radical polymerization on the emulsion particles, or adsorb to the emulsion particles as unreacted materials, or in the emulsion aqueous phase. Or adsorbed to emulsion particles as a copolymer with water-soluble monomers or as a copolymer of ethylenically unsaturated monomers used as an emulsifier, or present in the emulsion aqueous phase . In particular, the water resistance of the film obtained from the emulsion can be enhanced by increasing the ratio of the emulsion particles in the state of radically polymerized copolymer.
The ethylenically unsaturated monomer used as the emulsifier can identify each substance by pyrolysis gas chromatogram mass spectrometry (Py-GC-MS) of a film obtained from the emulsion. As another method, the aqueous phase component of the emulsion can be separated and then identified by fast atom bombardment mass spectrometry (FAB mass spectrum).
In the present invention, the emulsifier [D] is used in an amount of 0.05 to 10% by mass, preferably 0.1 to 5% by mass, based on the mass of the radical polymerizable monomer [A].

In the present invention, in addition to the emulsifier [D] containing an ethylenically unsaturated monomer having a sulfonic acid group, a sulfonate group, or a sulfate ester group, a normal surfactant may be used in combination. For example, anionic surfactants such as fatty acid soaps, alkyl sulfonates, alkyl sulfosuccinates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyl aryl sulfates, polyoxyethylene alkyl aryl ethers, polyoxyethylene sorbitan fatty acid esters , Non-reactive nonionic surfactants such as oxyethyleneoxypropylene block copolymers, α- [1] such as ADEKA rear soap NE-20, NE-30, NE-40 (product name, manufactured by Asahi Denka Kogyo Co., Ltd.) -[(Allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene, or Aqualon RN-10, RN-20, RN-30, RN-50 (product name, Daiichi Kogyo Seiyaku ( Polyoxyethylene alkyl propeny etc.) A nonionic surfactant that can be copolymerized with an ethylenically unsaturated monomer, which is called a reactive nonionic surfactant such as ruphenyl ether, can be used in combination.
The amount of the surfactant used is preferably 0.5% by mass or less, more preferably 0.25% by mass or less for the anionic surfactant with respect to the mass of the radical polymerizable monomer [A]. The non-reactive nonionic surfactant and the reactive nonionic surfactant are 2.0% by mass or less, preferably 1.0% by mass or less. When used in this range, a film with good water resistance is formed.

Polymerization initiator [E]
The emulsion polymerization in the present invention is a radical polymerization initiator that can be radically decomposed by heat or a reducing substance to cause addition polymerization of an ethylenically unsaturated monomer, and is a water-soluble or oil-soluble persulfate. Peroxides, azobis compounds and the like can be advantageously used. Examples include potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile, 2,2-azobis. (2-diaminopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile) can be mentioned, but it is also effective as a catalyst for promoting the hydrolysis reaction and condensation reaction of hydrolyzable silane. It is preferable to use potassium persulfate, sodium persulfate or ammonium persulfate. As a quantity of a radical polymerization initiator, 0.05 mass%-1 mass% can be normally used with respect to the mass of a radically polymerizable monomer [A].

In the present invention, the following two methods can be exemplified as an emulsification method for suppressing the amount of aggregates during the production of the emulsion, but is not limited thereto.
As the first emulsification method, a radically polymerizable monomer [A] and a silicone oligomer [B] are mixed and dissolved, and the solution, aqueous medium, polymerization initiator [E] and emulsifier [D] It is preferable that the mixed liquid consisting of is pre-emulsified liquid (a) using a homomixer or the like.
Compared with the first emulsification method, radically polymerizable monomer [A], silicone oligomer [B], aqueous medium, polymerization initiator [E] and emulsifier [D] are added simultaneously or sequentially and mixed. In the case of emulsification after this, emulsification with a homomixer or the like has a particularly low dispersibility of the silicone oligomer [B], and a large amount of aggregates are produced during the production of the emulsion.
After preparing a solution obtained by mixing and dissolving the radically polymerizable monomer [A] and the silicone oligomer [B], which are the characteristics of the technology of the present invention, the solution, an aqueous medium, a polymerization initiator [E] and an emulsifier [ By emulsifying the mixed solution consisting of D], the dispersibility of the silicone oligomer [B] can be dramatically improved, and aggregates during the production of the emulsion can be suppressed to a small amount.

  As a second emulsification method, a radically polymerizable monomer [A] and a silicone oligomer [B] are mixed and dissolved, and the solution, aqueous medium, polymerization initiator [E] and emulsifier [D] It is preferable that the mixed liquid consisting of the above is used as the pre-emulsion liquid (a) by a stirrer with high shearing force such as a high-pressure homogenizer. In addition to this first method, emulsification by a stirrer with higher shearing force results in an emulsion droplet diameter of 1 μm or less, and the radical polymerizable monomer [A] and the silicone oligomer [B] are more uniformly distributed. It can disperse | distribute and can suppress the aggregate in the emulsion manufacture small. Moreover, in this invention, it is important to suppress the temperature rise of the pre-emulsion liquid (a) by an emulsification process. Since the pre-emulsified liquid (a) contains the polymerization initiator [E], when the liquid temperature exceeds 50 ° C., the polymerization initiator [E] is decomposed to initiate the polymerization reaction, and the pre-emulsification is caused by the reaction heat. There is a possibility that the liquid temperature of the liquid (a) further rises and the reaction may run out of control. Therefore, a high-pressure homogenizer with a small amount of heat generation in the dispersion emulsification process is preferable as the stirrer of the pre-emulsion liquid to which high shear force is applied.

When batch-processing pre-emulsified liquid with an ultrasonic homogenizer, etc., there is a risk of reaching the decomposition temperature of the polymerization initiator [E] due to the amount of heat generated in the dispersion emulsification process. It is difficult to demonstrate effectiveness. Therefore, when using a stirrer that generates a large amount of heat during emulsification dispersion, such as an ultrasonic homogenizer, it is necessary to suppress the temperature rise of the pre-emulsified liquid (a) by performing a multi-stage continuous treatment.
Examples of high-pressure homogenizers include EmulsiFlex (product name, manufactured by AVESTIN), H3 series, HC3 series, HC5 series (product name, manufactured by Sanmaru Kikai Kogyo Co., Ltd.), and so on. Name, manufactured by BRANSON), US series, RUS series (product name, manufactured by Nippon Seiki Seisakusho Co., Ltd.).
In the first and second emulsification methods, a solution obtained by mixing and dissolving the radical polymerizable monomer [A] and the silicone oligomer [B] is used as the solution, the aqueous medium, the polymerization initiator [E], and the emulsifier. The pre-emulsion liquid (a) obtained by emulsifying the mixed liquid consisting of [D] with a homomixer or a high-pressure homogenizer is only hydrolysis of the alkoxy group derived from the silicone oligomer [B], and there is little by-product of alcohol. The stability of the pre-emulsion liquid (a) is not impaired, and since the amount of heat of hydrolysis generated is small, it is not necessary to take measures for increasing the temperature of the pre-emulsion liquid (a).

In the present invention, in the aqueous medium after mixing the pre-emulsified liquid (a) and the hydrolyzable silane [C] for obtaining an emulsion that suppresses agglomerates during the production of the emulsion and is excellent in polymerization stability. The following two methods can be given as addition methods to the polymerization reaction system, but are not limited thereto.
As a first addition method, the hydrolyzable silane [C] is separated from the pre-emulsified liquid (a) obtained by the first and second emulsification methods. D] and a pre-emulsified liquid (b) emulsified with a stirrer such as a homomixer. Since the pre-emulsion liquid (b) is neutral, the hydrolyzable silane compound [C] hardly undergoes hydrolysis, and almost no by-product alcohol is produced, but the hydrolyzable silane compound itself destroys the emulsified state. It is difficult to maintain this emulsion state for about 1 hour.
Therefore, the pre-emulsified liquid (b) may be introduced into the reaction system while emulsifying immediately before introduction into the reaction system.
When the pre-emulsified liquids (a) and (b) are mixed, hydrolysis proceeds to produce by-product alcohol, which destroys the emulsified state, and it is difficult to maintain this emulsified liquid state for about 1 hour.
Therefore, the method for introducing the pre-emulsified liquids (a) and (b) into the reaction system is not particularly limited, but it is preferable to emulsify and mix immediately before adding to the reaction system polymerized in the aqueous medium. It is more preferable to add continuously or intermittently to the reaction system polymerized in step (b).

As a second addition method, the pre-emulsified liquid (a) obtained by the first and second emulsification methods and the hydrolyzable silane compound [C] are mixed to the reaction system polymerized in the aqueous medium. The addition method is not particularly limited, but it is preferable to add continuously or intermittently in an aqueous medium continuously or intermittently.
When the hydrolyzable silane compound [C] is introduced into the reaction system polymerized in an aqueous medium without mixing from another position, the hydrolyzable silane compound [C] is polymerized during polymerization. Directly acting on the emulsion, a part of the emulsion is aggregated, and a large amount of aggregate is generated.
When the pre-emulsion (a) and the hydrolyzable silane compound [C] are mixed immediately before being introduced into the reaction system polymerized in an aqueous medium, and then introduced into the reaction system, the hydrolyzable silane compound [C] ] Diffuses into the reaction system together with the pre-emulsified liquid (a), hydrolysis starts after mixing, and the generation of by-product alcohol also occurs in parallel, so there is no sudden increase in alcohol in the aqueous medium. Therefore, it is considered that no aggregate is generated in the emulsion.

In the present invention, as a mixing method of the pre-emulsified liquid (a) and the hydrolyzable silane [C] for obtaining an emulsion that suppresses agglomerates during the production of the emulsion and is excellent in polymerization stability, the following method is exemplified. However, it is not limited to these.
When the pre-emulsified liquid (a) obtained by the first and second emulsification methods and the hydrolyzable silane [C] are vigorously mixed, the hydrolyzable silane [C] and the pre-emulsified liquid (a) are formed into the same droplet particles. Further, by forming droplet particles having a uniform composition, the hydrolyzable silane [C] is rapidly hydrolyzed, and the emulsified state of the pre-emulsion liquid (a) is destroyed due to generation of alcohol or the like. Hydrolyzable silane [C] also lowers the surface tension of the emulsion and destroys the emulsified state.
Therefore, at the time of mixing, the mixing method of the pre-emulsion liquid (a) and the hydrolyzable silane [C] is preferably gentle stirring. Specifically, the hydrolyzable silane [C] has an average particle size of 10 μm. The above emulsified state is preferable, and more preferably, the average particle size of the hydrolyzable silane [C] is more preferably 100 μm or more.

  In the present invention, a specific mixing method of the pre-emulsified liquid (a) and the hydrolyzable silane [C] includes a static mixer, a continuous hermetic dispersing / emulsifying machine, and the like. You may mix through a net | network. For example, static mixers include static mixers N10 series, N16 series, N60 series (product names, manufactured by Noritake Co., Ltd.) and the like, and 125 L and 275 L (product names, Silverson Machines) as continuous hermetic dispersers / emulsifiers. , Inc.), T.M. K. Pipeline homomixer (product name, manufactured by Tokushu Kika Kogyo Co., Ltd.) K. A homomic line mixer (product name, manufactured by Tokushu Kika Kogyo Co., Ltd.) and the like can be mentioned, and when these are used, it is possible to suppress the number of rotations of stirring as much as possible. Other mixing methods include a method of filling the outlet end of another Y-shaped tube with a metal net, Raschig ring or zeolite. As the mixing method, a continuous hermetic disperser / emulsifier, a method of filling a metal net, Raschig ring, zeolite, or the like at the outlet end of the Y-shaped tube is preferable. The mixing temperature is 60 ° C. or lower, preferably 50 ° C. or lower, more preferably 40 ° C. or lower. When the above conditions are not satisfied, many hydrolyzable silane compounds are hydrolyzed due to the acidity or basicity of the radical polymerizable monomer emulsion, and the emulsion is destroyed. And separation in the water layer. As a result, many aggregates are generated in the reaction system during the polymerization.

The emulsion of the present invention can be obtained, for example, by performing emulsion polymerization, that is, emulsion polymerization by radical polymerization of a radical polymerizable monomer and emulsion polymerization by hydrolysis / condensation reaction of a hydrolyzable silane compound simultaneously in an aqueous medium. It is done. The aqueous medium referred to here is one that is introduced into the reaction system, and water is mainly used, but a water-soluble solvent such as a lower alcohol having 1 to 3 carbon atoms or acetone is added to water. Including things. The amount of the solvent other than water added at this time is preferably 20% by mass or less in the emulsion. Here, the amount of the solvent soluble in water is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably water alone. When this amount is exceeded, the emulsified state of the pre-emulsified liquid (a) is destroyed and the polymerization stability becomes poor.
In the present invention, the pH of the reaction system after mixing the pre-emulsified liquid (a) obtained by the first and second emulsification methods with the hydrolyzable silane [C] or the pre-emulsified liquid (b) is limited. However, by carrying out the polymerization at a pH of 4.0 or less, the condensation reaction of the hydrolyzable silane occurs rapidly, and the condensation reaction can be prevented from proceeding after the emulsion polymerization, so the storage stability as a product is good and the reaction system The pH is preferably 4.0 or less, more preferably from 1.5 to 3.0.

  In the present invention, it is preferable to include an ultraviolet absorber and / or a light stabilizer in the emulsion in order to impart high weather resistance. As a method for adding the ultraviolet absorber and / or the light stabilizer to the emulsion, It is preferable to make it exist at the time of emulsion polymerization. When UV absorbers and / or light stabilizers are added after being mixed with film-forming aids, etc., they are inferior in dispersibility and are concentrated at the particle interface of the resulting coating film. Long-term durability is not improved. It is preferable to use 0.1 mass%-5 mass% of ultraviolet absorbers and / or light stabilizers with respect to the mass of the radical polymerizable monomer [A]. Also, use a radical polymerizable compound having a radical polymerizable double bond in the molecule as an ultraviolet absorber, and a radical polymerizable compound having a radical polymerizable double bond in the molecule as a light stabilizer. You can also. Further, it is preferable to use an ultraviolet absorber and a light stabilizer in combination because the film is particularly excellent in weather resistance when the film is formed using the highly durable emulsion.

  In the present invention, it is preferable to use at least one selected from benzophenone, benzotriazole, and triazine as the ultraviolet absorber, and at least one selected from hindered amines as the light stabilizer. Combined with a silicone-modified acrylic emulsion with excellent durability and a high benzophenone-based, benzotriazole-based, triazine-based UV absorber, and a hindered amine light stabilizer with high UV-absorbing ability, it exhibits excellent durability due to a synergistic effect. Specific examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and 2-hydroxy-4- n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2,2′- Dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4 -Methoxy-2'-cal Carboxymethyl benzophenone, and the like 2-hydroxy-4-stearyloxy benzophenone. Specific examples of radical polymerizable benzophenone-based UV absorbers include 2-hydroxy-4-acryloxybenzophenone, 2-hydroxy-4-methacryloxybenzophenone, 2-hydroxy-5-acryloxybenzophenone, and 2-hydroxy-5. -Methacryloxybenzophenone, 2-hydroxy-4- (acryloxy-ethoxy) benzophenone, 2-hydroxy-4- (methacryloxy-ethoxy) benzophenone, 2-hydroxy-4- (methacryloxy-diethoxy) benzophenone, 2-hydroxy-4- (Acryloxy-triethoxy) benzophenone. Specific examples of benzotriazole-based UV absorbers that can be used in the present invention include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (2′-hydroxy-5′-tert-butylphenyl). ) Benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2- Hydroxy-3,5-di-tert-octylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenyl] benzotriazole), methyl-3- [3-tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] Condensation product of lopionate and polyethylene glycol (molecular weight 300) (product name: TINUVIN 1130, manufactured by Ciba-Geigy Corp.), isooctyl-3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl- 4-hydroxyphenyl] propionate (manufactured by Ciba Geigy Japan, product name: TINUVIN 384), 2- (3-dodecyl-5-methyl-2-hydroxyphenyl) benzotriazole (manufactured by Ciba Geigy Japan, product name: TINUVIN 571) ), 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) ) Benzotriazole, 2- (2′-hydroxy-4′-oct) Ciphenyl) benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl] benzotriazole, 2,2 -Methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2H-benzotriazol-2-yl) -4,6 -Bis (1-methyl-1-phenylethyl) phenol (Nippon Ciba-Geigy Co., Ltd., product name: TINUVIN900). Specific examples of radically polymerizable benzotriazole-based UV absorbers include 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd., product name: RUVA- 93), 2- (2′-hydroxy-5′-methacryloxyethyl-3-tert-butylphenyl) -2H-benzotriazole, 2- (2′-hydroxy-5′-methacrylyloxypropyl-3-tert) -Butylphenyl) -5-chloro-2H-benzotriazole, 3-methacryloyl-2-hydroxypropyl-3- [3 '-(2 "-benzotriazolyl) -4-hydroxy-5-tert-butyl] Phenyl propionate (manufactured by Nippon Ciba-Geigy Co., Ltd., product name: CGL-104).

  Specific examples of triazine-based ultraviolet absorbers that can be used in the present invention include TINUVIN400 (product name, manufactured by Nippon Ciba-Geigy Co., Ltd.). As the hindered amine light stabilizer that can be used in the present invention, those having a low basicity are preferable, and specifically, those having a base constant (pKb) of 8 or more are preferable. Specifically, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (2,2,6,6-tetramethylpiperidyl) sebacate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-butylmalonate, 1- [2- [3- (3,5-di-tert- Butyl-4-hydroxyphenyl) propynyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propynyloxy] -2,2,6,6-tetramethylpiperidine, A mixture of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl-sebacate (Nippon Ciba Geigy ( ), Product name: TINUVIN292), bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, TINUVIN123 (product name, manufactured by Nihon Ciba-Geigy Corporation), and the like. Specific examples of the radical polymerizable hindered amine light stabilizer include 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl acrylate, 2, 2,6,6-tetramethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl acrylate, 1,2,2,6,6-pentamethyl-4-iminopiperidyl methacrylate, 2, 2,6,6, -tetramethyl-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4-cyano-1,2,2,6,6- Examples include pentamethyl-4-piperidyl methacrylate.

  Usually, the polymerization reaction is preferably carried out at a polymerization temperature of 65 to 90 ° C. under normal pressure, but can also be carried out under high pressure in accordance with the characteristics such as vapor pressure at the polymerization temperature of the monomer. The polymerization time includes introduction time and aging time after introduction. The introduction time is usually several minutes when various raw materials are simultaneously introduced into the reaction system, and when sequentially introducing various raw materials into the reaction system, the heat is gradually introduced into the reaction system in a range where heat generated by polymerization can be removed. Although it depends on the polymer concentration in the finally obtained emulsion, it is usually 10 minutes or longer. The aging time after the introduction is preferably at least 10 minutes or more. Below this polymerization time, the raw materials may remain as they are, or the hydrolyzable silane may not be condensed and may remain as a hydrolyzate. When acceleration of the polymerization rate and polymerization at a low temperature of 70 ° C. or lower are desired, for example, a reducing agent such as sodium bisulfite, ferrous chloride, ascorbate, or longalite may be used in combination with the radical polymerization catalyst. It is advantageous. Furthermore, a chain transfer agent such as dodecyl mercaptan can be optionally added to adjust the molecular weight.

In the silicone modification in the present invention, after completion of emulsion polymerization, as a curing catalyst during film formation, for example, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, tin octylate, tin laurate, iron octylate, lead octylate, An amine compound such as a metal salt of an organic acid such as tetrabutyl titanate, n-hexylamine, or 1,8-diazabicyclo [5,4,0] -7-undecene may be added to the highly durable emulsion of the present invention. it can.
When these curing catalysts are not water-soluble, they are preferably emulsified with a surfactant and water when used. In order to maintain long-term dispersion stability of the emulsion, the highly durable emulsion of the present invention can be adjusted to a pH range of 5 to 10 using amines such as ammonia, sodium hydroxide, potassium hydroxide, and dimethylaminoethanol. preferable.
The acrylic emulsion produced according to the present invention preferably has an average particle size of the dispersoid of 10 to 1000 nm. The mass ratio of the dispersoid (solid content) in the obtained emulsion to the aqueous medium as the dispersion medium is 70/30 or less, preferably 30/70 or more and 65/35 or less.

The highly durable emulsion of the present invention is useful as a finishing material for paints, building materials, or as finishing agents for adhesives, paper processing agents, woven fabrics, and non-woven fabrics. Specifically, it can be applied to various foundations such as concrete, cement mortar, slate plate, calcium plate, gypsum board, extruded plate, foamed concrete, building materials based on woven or non-woven fabric, metal building materials, etc. Architectural finishing materials: Main materials and top coats for multi-layer finish coating materials, thin finish coating materials, thick finish coating materials, stone-like finish materials, gloss paint, synthetic resin emulsion paints, metal paints, wood parts It is useful as a paint and roofing paint.
In the highly durable emulsion of the present invention, components that are usually added to and blended with water-based paints, such as film forming aids, thickeners, antifoaming agents, pigments, dispersants, dyes, preservatives, etc., are optionally blended. be able to.

  In one preferred embodiment of the present invention, the radically polymerizable monomer [A] comprises an acrylate monomer and consists of [A1] and [A2] which are the same or different from each other, and comprises a silicone oligomer [B] Having an alkoxy group content of 2 to 30% and consisting of [B1] and [B2] different from each other, and the emulsifier [D] is an ethylenically unsaturated monomer having a sulfonic acid group or a sulfonate group Body, an ethylenically unsaturated monomer having a sulfate ester group, and a mixture thereof and consisting of emulsifiers [D1] and [D2] which are the same or different from each other, and the emulsion polymerization is performed in step [1], Step [2] is performed in this order. In step [1], the radical polymerizable monomer [A1], the silicone oligomer [B1], the emulsifier [D1], and the polymerization initiator [ 1] and, if necessary, an emulsion containing an aqueous medium, emulsion polymerization is carried out in the aqueous medium to obtain step [1] emulsion. In step [2], radical polymerization is performed in the aqueous medium. Mixing an emulsion comprising a monomer [A2], a silicone oligomer [B2], an emulsifier [D2], a polymerization initiator [E2], and, if necessary, an aqueous medium, and a hydrolyzable silane compound [C] However, by adding the emulsion to step [1] emulsion, the final desired emulsion can be obtained, and it is also possible to have an ultraviolet absorber and / or a light stabilizer present during the emulsion polymerization.

  According to another preferred embodiment of the present invention, the radical polymerizable monomer [A] contains an acrylate monomer and is the same or different from each other [A1], [A2] and [A3 The silicone oligomer [B] has an alkoxy group content of 2 to 30% and is the same or different from each other [B1] and [B2], and the emulsifier [D] is a sulfonic acid group or sulfonate. Emulsifier [D1], [D2] and [D3] selected from the group consisting of an ethylenically unsaturated monomer having a group, an ethylenically unsaturated monomer having a sulfate ester group, and a mixture thereof. The emulsion polymerization is carried out in the order of step [1], step [2] and step [3]. In step [1], the radical polymerizable monomer [A1] and silicone A step [1] emulsion is obtained by subjecting a pre-emulsion comprising a gormer [B1], an emulsifier [D1], a polymerization initiator [E1], and an aqueous medium to emulsion polymerization in an aqueous medium, thereby obtaining a step [2]. In step [1], by adding a pre-emulsion comprising a radical polymerizable monomer [A2], an emulsifier [D2], a polymerization initiator [E2] and an aqueous medium to the step [1] emulsion. In step [3], emulsion polymerization is carried out to obtain an emulsion. In step [3], a radically polymerizable monomer [A3], a silicone oligomer [B2], an emulsifier [D3] and a polymerization initiator [E3] are obtained. If necessary, an emulsion composed of an aqueous medium is added to the step [2] emulsion to carry out emulsion polymerization to obtain a final desired emulsion. In addition, the emulsion is modified with silicone during emulsion polymerization while mixing the emulsion and the hydrolyzable silane compound [C], and a high durability obtained by allowing an ultraviolet absorber and / or a light stabilizer to be present during emulsion polymerization. An emulsion is provided. Silicone modification can be performed during emulsion polymerization while mixing the emulsion in step [1], step [2] and / or step [3] with the hydrolyzable silane compound [C].

The present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the part and% in an Example and a comparative example represent a mass part and the mass%, respectively. The evaluation of the polymerization stability and the physical property test of the obtained aqueous silicone-modified acrylate polymer emulsion were carried out using the emulsion according to the following evaluation and test methods.
<Measurement of pre-emulsion temperature>
In Examples and Comparative Examples, the liquid temperature of each emulsified pre-emulsified liquid was measured with a digital thermometer.
<Evaluation of polymerization stability>
The aqueous silicone-modified acrylate polymer emulsion obtained after the emulsion polymerization was filtered through a 100-mesh filter cloth, and the mass of the filtration residue was divided by the mass of the aqueous silicone-modified acrylate polymer emulsion to obtain the residue rate.
(Judgment criteria) A: Residue rate is less than 20 ppm
○: Residue rate is 20 ppm or more and less than 100 ppm
Δ: Residue rate is 100 ppm or more
×: A large amount of aggregate is generated

<Evaluation of filterability>
The aqueous silicone-modified acrylate polymer emulsion obtained after the emulsion polymerization was filtered through a 100 mesh filter cloth, and the time required for completing the filtration was evaluated.
(Judgment criteria) ○: Filtration time is less than 30 seconds
Δ: Filtration time of 30 seconds or more and less than 60 seconds
X: Filtration time of 60 seconds or more <Measurement of particle diameter>
The average particle size of the obtained aqueous silicone-modified acrylate polymer emulsion was measured with a Microtrac particle size distribution meter manufactured by Leeds & Northrup.

<Evaluation of weather resistance>
An enamel paint is prepared with the following composition for the aqueous silicone-modified acrylate polymer emulsion obtained after emulsion polymerization, an irradiation test is conducted for 2500 hours with a sunshine weather meter, and the appearance of the coating film (cracks, peeling, etc.) Was visually observed. At the same time, the gloss retention rate was also evaluated.
(Judgment criteria) ○: No change in appearance
×: Cracking and peeling off Adjustment of enamel coating composition Emulsion of each example (solid content 40% conversion) 250 parts Ethylene glycol monobutyl ether 20 parts Ethylene glycol mono 2-ethylhexyl ether 40 parts Titanium oxide 130 parts Thickener 0. 1 copy

[Example 1]
Sulfosuccinic acid diester ammonium salt having a double bond copolymerizable with 340 parts of water and ethylenically unsaturated monomer in a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer (product) Name: Ramtel S-180A, manufactured by Kao Corporation), 5 parts of 20% aqueous solution was added, the temperature was raised to 80 ° C., and 5 minutes after adding 10 parts of 2% aqueous solution of ammonium persulfate, methyl methacrylate 88 was added. Parts, 50 parts of cyclohexyl methacrylate and 110 parts of butyl acrylate, and 135 parts of methylphenylmethoxysilicone oligomer (product name: KR510, manufactured by Shin-Etsu Chemical Co., Ltd.), and then a 20% aqueous solution of LATEMUL S-180A 30 parts, 15 parts of a 2% aqueous solution of ammonium persulfate and 313 parts of water are mixed, and the mixture is emulsified with a homomixer and pre-emulsified. 1 was obtained. The temperature of this pre-emulsion remained at a rise from 24 ° C to 27 ° C.

The pre-emulsion 1 obtained, 3.3 parts of γ-methacryloxypropyltrimethoxysilane, 67 parts of dimethyldimethoxysilane, 17 parts of methyltrimethoxysilane and 30 parts of a 10% aqueous solution of methacrylic acid Tube [Molecular sieve 3A (product name: manufactured by Wako Pure Chemical Industries, Ltd.)] is filled to the point where the outlet of the Y-shaped tube is filled with 100 mesh wire mesh and the liquid in the three dripping tanks is mixed. The pre-emulsion 1 containing the monomer and the silicone oligomer and the hydrolyzable silane compound were adjusted so as to be gently mixed. ] Was allowed to flow into the reaction vessel from the dropping tank over 1 hour. At this time, heat generation due to hydrolysis of the hydrolyzable silane compound in the mixing portion of the Y-shaped tube was not observed. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 30 minutes.
Next, 70 parts of water, 65 parts of methyl methacrylate, 20 parts of cyclohexyl methacrylate and 15 parts of butyl acrylate, 2 parts of methacrylic acid, 6 parts of 20% aqueous solution of Latemul S-180A, and 5 parts of 2% aqueous solution of ammonium persulfate The liquid was emulsified with a homomixer, and the resulting pre-emulsion liquid 2 was allowed to flow into the reaction vessel from the dropping tank over 1 hour. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 30 minutes.

Next, 65 parts of methyl methacrylate, 30 parts of cyclohexyl methacrylate and 53 parts of butyl acrylate, 5 parts of benzotriazole ultraviolet absorber (product name TINUVIN 384, manufactured by Ciba Geigy Japan), hindered amine light stabilizer (product name TINUVIN 123) , Nippon Ciba-Geigy Co., Ltd.) 2.5 parts, KR510: 67 parts, and then mixed with 10 parts of 20% aqueous solution of Latemul S-180A, 8 parts of 2% aqueous solution of ammonium persulfate, and 173 parts of water And the mixture was emulsified with a homomixer. The temperature of the pre-emulsified liquid 3 remained at an increase from 24 ° C. to 26 ° C.
The pre-emulsion 3 obtained, 1.7 parts of γ-methacryloxypropyltrimethoxysilane, 33 parts of dimethyldimethoxysilane, 8 parts of methyltrimethoxysilane and 30 parts of a 10% aqueous solution of methacrylic acid While mixing with a metal mesh in the tube, it was allowed to flow into the reaction vessel from the dropping tank over 1 hour. At this time, heat generation due to hydrolysis of the hydrolyzable silane compound in the mixing portion of the Y-shaped tube was not observed. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 120 minutes.
After cooling to room temperature, the hydrogen ion concentration was measured and found to be 2.9. A 25% aqueous ammonia solution was added to the above mixture to adjust the pH to 8, and then filtered through a 100 mesh wire mesh.
The dry mass of the filtered agglomerate was as small as 18 ppm with respect to the obtained solid content mass, and there was also a small amount of deposits on the inner wall of the reaction vessel and the stirring blade.
The obtained emulsion had a solid content of 40.3% and an average particle size of 109 nm.
The results of the properties of this emulsion and the calculated values of byproduct methanol are shown in Table 1.

[Example 2]
The pre-emulsified liquid 1 and the pre-emulsified liquid 3 of Example 1 were further subjected to a one-pass emulsification treatment at 5000 bar with a high-pressure homogenizer (product name: EmulsiFlex, manufactured by AVESTIN) to obtain the pre-emulsified liquid 1 and the pre-emulsified liquid 3. Except for the above, the same processing as in Example 1 was performed. At this time, the temperature of the pre-emulsion liquid 1 remained at a rise from 24 ° C. to 37 ° C., and the temperature of the pre-emulsion liquid 3 remained at a rise from 24 ° C. to 35 ° C.
Further, no heat was generated at the Y-tube mixing part in the mixing of the pre-emulsified liquid 1 and 3 and the hydrolyzable silane compound.
The dry mass of the filtered agglomerate was very small, less than 9 ppm with respect to the obtained solid content mass, and the deposits on the inner wall of the reaction vessel and the stirring blade were also slight.
The obtained emulsion had a solid content of 40.4% and an average particle size of 102 nm.
The results of the properties of this emulsion and the calculated values of byproduct methanol are shown in Table 1.

[Comparative Example 1]
Sulfosuccinic acid diester ammonium salt having a double bond copolymerizable with 340 parts of water and ethylenically unsaturated monomer in a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer (product) 5 parts of 20% aqueous solution of name: Ramtel S-180A, manufactured by Kao Corporation) was added, the temperature was raised to 80 ° C., and then 10 parts of 2% aqueous solution of ammonium persulfate was added.
5 minutes later, 88 parts of methyl methacrylate, 50 parts of cyclohexyl methacrylate and 110 parts of butyl acrylate, 3 parts of methacrylic acid, 30 parts of 20% aqueous solution of Latemul S-180A, 15 parts of 2% aqueous solution of ammonium persulfate, water 340 Part, 3.3 parts of γ-methacryloxypropyltrimethoxysilane, 100 parts of dimethyldimethoxysilane, and 200 parts of methyltrimethoxysilane were prepared, and the mixture was emulsified with a homomixer to obtain pre-emulsion liquid 1. It was. Since the temperature of the pre-emulsion liquid 1 rose from 24 ° C. to 55 ° C., the container containing the pre-emulsion liquid 1 was cooled to 20 ° C. with ice water.
The obtained pre-emulsion liquid 1 was allowed to flow into the reaction vessel from the dropping tank over 1 hour. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 30 minutes.
Next, 70 parts of water, 65 parts of methyl methacrylate, 20 parts of cyclohexyl methacrylate and 15 parts of butyl acrylate, 2 parts of methacrylic acid, 6 parts of 20% aqueous solution of Latemul S-180A, 5 parts of 2% aqueous solution of ammonium persulfate The mixed solution was emulsified with a homomixer to obtain a pre-emulsion solution 2.
The obtained pre-emulsion 2 was allowed to flow into the reaction vessel from the dropping tank over 1 hour. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 30 minutes.

Next, 65 parts of methyl methacrylate, 30 parts of cyclohexyl methacrylate and 53 parts of butyl acrylate, 2 parts of methacrylic acid, 5 parts of benzotriazole ultraviolet absorber (product name TINUVIN 384, manufactured by Ciba-Geigy Japan), hindered amine light Stabilizer (product name TINUVIN123, manufactured by Nippon Ciba-Geigy Co., Ltd.) 2.5 parts is mixed and dissolved, then 10 parts of 20% aqueous solution of Latemul S-180A, 8 parts of 2% aqueous solution of ammonium persulfate, 190 parts of water, 1.7 parts of γ-methacryloxypropyltrimethoxysilane, 50 parts of dimethyldimethoxysilane, and 100 parts of methyltrimethoxysilane were mixed, and the mixture was emulsified with a homomixer to obtain pre-emulsion 3. Since the temperature of this pre-emulsion liquid 3 rose from 24 ° C. to 53 ° C., the container containing the pre-emulsion liquid 3 was cooled to 20 ° C. with ice water.
The obtained pre-emulsified liquid 3 was allowed to flow into the reaction vessel from the dropping tank over 1 hour. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 120 minutes.
A 25% aqueous ammonia solution was added to the mixed solution to adjust the pH to 8, followed by filtration through a 100 mesh wire net.
A large amount of agglomerates having a dry mass of the filtered aggregate of 50% or more with respect to the obtained solid content mass was generated.
There were also many deposits on the inner wall of the reaction vessel and the stirring blades.
The results of the properties of this emulsion and the calculated values of byproduct methanol are shown in Table 1.

[Comparative Example 2]
Sulfosuccinic acid diester ammonium salt having a double bond copolymerizable with 340 parts of water and ethylenically unsaturated monomer in a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer (product) 5 parts of 20% aqueous solution of name: Ramtel S-180A, manufactured by Kao Corporation) was added, the temperature was raised to 80 ° C., and then 10 parts of 2% aqueous solution of ammonium persulfate was added.
Five minutes later, 88 parts of methyl methacrylate, 50 parts of cyclohexyl methacrylate and 110 parts of butyl acrylate, and 135 parts of methylphenylmethoxysilicone oligomer (product name: KR510, manufactured by Shin-Etsu Chemical Co., Ltd.) were dissolved. Was prepared by mixing 30 parts of 20% aqueous solution of Latemul S-180A, 15 parts of 2% aqueous solution of ammonium persulfate and 313 parts of water, emulsifying the mixture with a homomixer, and further using an ultrasonic homogenizer (product name: SONIFEIR450 (manufactured by BRANSON) was used to obtain a pre-emulsion solution 1 that was emulsified in a batch system for 10 minutes. Since the liquid temperature of the pre-emulsion liquid 1 rose from 24 ° C. to 65 ° C., the container containing the pre-emulsion liquid 1 was cooled to 20 ° C. with ice water.

The pre-emulsion 1 obtained, 3.3 parts of γ-methacryloxypropyltrimethoxysilane, 67 parts of dimethyldimethoxysilane, 17 parts of methyltrimethoxysilane and 30 parts of a 10% aqueous solution of methacrylic acid Tube [Molecular Sieves 3A (product name: manufactured by Wako Pure Chemical Industries, Ltd.)] is filled up to the point where the outlet of the Y-shaped tube is filled with a 100-mesh wire mesh and the liquid in the dripping tank is mixed. And a pre-emulsion 1 containing a silicone oligomer and a hydrolyzable silane compound were adjusted so as to be gently mixed. ] Was allowed to flow into the reaction vessel from the dropping tank over 1 hour. At this time, heat generation due to hydrolysis of the hydrolyzable silane compound in the mixing portion of the Y-shaped tube was not observed. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 30 minutes.
Next, 70 parts of water, 65 parts of methyl methacrylate, 20 parts of cyclohexyl methacrylate and 15 parts of butyl acrylate, 2 parts of methacrylic acid, 6 parts of 20% aqueous solution of Latemule S-180A, 5 parts of 2% aqueous solution of ammonium persulfate The mixed solution was emulsified with a homomixer, and the obtained pre-emulsion solution 2 was allowed to flow into the reaction vessel from the dropping tank over 1 hour. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 30 minutes.

Next, 65 parts of methyl methacrylate, 30 parts of cyclohexyl methacrylate and 53 parts of butyl acrylate, 5 parts of benzotriazole ultraviolet absorber (product name TINUVIN 384, manufactured by Ciba Geigy Japan), hindered amine light stabilizer (product name TINUVIN 123) , Manufactured by Nippon Ciba-Geigy Co., Ltd.) 2.5 parts, KR510: 67 parts, then 10 parts of 20% aqueous solution of Latemul S-180A, 8 parts of 2% aqueous solution of ammonium persulfate, and 173 parts of water After mixing and emulsifying the mixed solution with a homomixer, a pre-emulsion solution 3 was further obtained which was subjected to an emulsification treatment with an ultrasonic homogenizer (product name: SONIFEIR450, manufactured by BRANSON) for 10 minutes. Since the liquid temperature of this pre-emulsion liquid 3 rose from 24 ° C. to 67 ° C., the container containing the pre-emulsion liquid 3 was cooled to 20 ° C. with ice water.
The pre-emulsion 3 obtained, 1.7 parts of γ-methacryloxypropyltrimethoxysilane, 33 parts of dimethyldimethoxysilane, 8 parts of methyltrimethoxysilane and 30 parts of a 10% aqueous solution of methacrylic acid While mixing with a metal mesh in the tube, it was allowed to flow into the reaction vessel from the dropping tank over 1 hour. At this time, heat generation due to hydrolysis of the hydrolyzable silane compound in the mixing portion of the Y-shaped tube was not observed. During the inflow, the temperature in the reaction vessel was kept at 80 ° C. After the inflow was completed, the temperature in the reaction vessel was raised to 80 ° C. and kept for 120 minutes.
After cooling to room temperature, the hydrogen ion concentration was measured and found to be 2.9. After adjusting the pH to 8 by adding 25% aqueous ammonia solution to the above mixture, 1
Filtration through a 00 mesh wire mesh.
The dry mass of the filtered agglomerate was as small as 15 ppm with respect to the obtained solid content mass, and there was also a small amount of deposits on the inner wall of the reaction vessel and the stirring blade.
The obtained emulsion had a solid content of 40.2% and an average particle size of 106 nm.
The results of the properties of this emulsion and the calculated values of byproduct methanol are shown in Table 1.

As is clear from Table 1, in Comparative Example 1 in which alkoxysilane was used without using a silicone oligomer, the amount of heat of hydrolysis was large, the temperature of the emulsion increased, and a cooling step for the emulsion was required. It became. Also, the amount of by-product alcohol was large, resulting in a large amount of polymerization residue.
Moreover, in Comparative Example 2, although the silicone oligomer [B] was used, since the batch type ultrasonic homogenizer was used for the emulsification process, the temperature of the emulsified liquid increased, and the emulsion liquid cooling step was required.
Compared to Comparative Example 1 and Comparative Example 2, both the Examples showed a smaller increase in the temperature of the emulsion, and the cooling step was unnecessary. Moreover, since the amount of by-product alcohol was small, the polymerization stability was good and the polymerization residue was small.
This is because the silicone oligomer [B] was used, so that the amount of hydrolysis reaction heat could be suppressed, the concentration of by-product alcohol could be reduced, and the temperature increase during the emulsification treatment by the high-pressure homogenizer was small.
In addition, in the results of the weather resistance test of Examples 1 and 2 and Comparative Example 2, both maintain a high gloss retention and no cracks are generated.
Therefore, according to the present invention, a highly durable emulsion having extremely excellent polymerization stability can be provided by a production method with a small equipment load and few processing steps.

The present invention is highly durable capable of forming a coating film excellent in stain resistance, flexibility, water resistance, weather resistance, durability, pigment dispersibility, gloss retention, adhesion, rust resistance, and water resistance. An acrylic emulsion can be provided.
Specifically, it is useful as a finishing material for paints, building materials, surface treatments or finishing materials, adhesives, paper processing agents, woven fabrics, and non-woven fabrics, and in particular, concrete, cement mortar, slate plates, calcium plates, plaster. Main materials and tops for multi-layer finishing coating materials as paints or building finishing materials for various substrates such as boards, extruded plates, inorganic building materials such as expandable concrete, building materials based on woven or non-woven fabric, and metal building materials As a synthetic resin emulsion paint for coatings, thin finish coating materials, thick finish coating materials, stone-like finish materials, gloss paints, etc., it provides highly durable emulsions useful as metal paints, wood paints, and tile paints. be able to.

Claims (10)

  A hydrolyzable silane [C] is mixed with a pre-emulsion liquid composed of a radical polymerizable monomer [A], a silicone oligomer [B], a polymerization initiator [E] and an emulsifier [D], and then in an aqueous medium. A method for producing a highly durable emulsion, characterized by polymerization.   The pre-emulsion liquid comprises a solution obtained by mixing and dissolving the radical polymerizable monomer [A] and the silicone oligomer [B], an aqueous medium, a polymerization initiator [E], and an emulsifier [D]. Item 2. A process for producing a highly durable emulsion according to Item 1.   The method for producing a highly durable emulsion according to claim 1 or 2, wherein the pre-emulsion is polymerized in an aqueous medium while continuously or intermittently mixing the hydrolyzable silane [C]. .   The method for producing a highly durable emulsion according to any one of claims 1 to 3, wherein the pH of the pre-emulsion liquid is 4.0 or less.   The method for producing a highly durable emulsion according to any one of claims 1 to 4, wherein the oil droplet diameter of the pre-emulsion is 1.0 µm or less. The silicone oligomer [B] is a condensate of a hydrolyzable silane compound represented by the following formula (a), and the silicone oligomer [B] has an alkoxy group content of 0.1 to 50% per molecule. The method for producing a highly durable emulsion according to any one of claims 1 to 5.
(R ¹ ) _n —Si— (R ² ) _4-n (a)
(In the formula, n is an integer of 0 to 3, and each R ¹ is independently hydrogen, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, or 5 to 5 carbon atoms. 6 cycloalkyl groups, a vinyl group, a phenyl group, an alkyl acrylate group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently selected from 1 to 1 carbon atoms. 8 is selected from an alkoxy group, an acetoxy group, a hydroxyl group, an epoxy group, an ethylene oxide group, or a halogen atom, and at least one is an alkoxy group.) The silicone oligomer [B] is represented by the following formulas (1), (2) and (3), and the amount of alkoxy groups per molecule of the silicone oligomer [B] is 0.1 to 50%. Item 7. A method for producing a highly durable emulsion according to any one of Items 1 to 6.

(In the formula, each R ¹ is independently hydrogen, an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, a vinyl group, or carbon. Selected from an alkyl acrylate group having 1 to 10 carbon atoms or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, a hydroxyl group, an epoxy group, or (Selected from ethylene oxide group, at least one is an alkoxy group. M represents a positive integer of 1 to 999.)   8. The mass ratio of the silicone oligomer [B] to the total mass of the silicone oligomer [B] and the hydrolyzable silane compound [C] is 5% to 95%. A method for producing a highly durable emulsion according to Item.   5% by mass or more of the radical polymerizable monomer [A] is composed of one or more monomers selected from the group consisting of (meth) acrylate monomers having a cycloalkyl group. The method for producing a highly durable emulsion according to any one of claims 1 to 8.   A highly durable emulsion obtained by the production method according to claim 1.