JP5437523B1 - Surface conditioner - Google Patents

Abstract

の片末端（メタ）アクリル変性のシロキシ基含有モノ（メタ）アクリレートモノマー０．０１〜２０．００重量部、並びに、水酸基含有（メタ）アクリレート類、水酸基含有（メタ）アクリルアミド類、ブロックイソシアネート基含有（メタ）アクリレート類である官能基含有モノマーを最大で１０重量部のうち、少なくともアクリルアミドモノマーとシロキシ基含有モノ（メタ）アクリレートモノマーとが共重合され重量平均分子量を１５００〜５００００とする共重合物を含有し、被膜表面に親水性を付与する。
【選択図】なしProvided is a surface conditioner capable of imparting hydrophilicity and antifouling property to a coating surface.
[MEANS FOR SOLVING PROBLEMS] An amount of 80.00 to 99.99 parts by weight of an acrylamide monomer which is dimethyl (meth) acrylamides or diethyl (meth) acrylamides, chemical formula (I)

0.01 to 20.00 parts by weight of a mono- (meth) acrylate-modified mono (meth) acrylate monomer modified with a single terminal (meth) acryl, and a hydroxyl group-containing (meth) acrylate, a hydroxyl group-containing (meth) acrylamide, and a blocked isocyanate group A copolymer having a weight average molecular weight of 1500 to 50000 by copolymerizing at least an acrylamide monomer and a siloxy group-containing mono (meth) acrylate monomer out of a maximum of 10 parts by weight of a functional group-containing monomer that is a (meth) acrylate. And imparts hydrophilicity to the coating surface.
[Selection figure] None

Description

  The present invention relates to a surface conditioner that imparts hydrophilicity or antifouling property to the surface of a film formed with the coating agent by blending in a small amount with the coating agent that forms the film.

  In recent years, with the increase in added value, there is a demand for improving the antifouling property by hydrophilizing the coating surface formed with various coating agents such as aqueous / oil-based paints, baking paints, and inks.

  In general, as a method for imparting hydrophilicity to a film, the surface of the formed film is made hydrophilic by making the resin itself contained in the coating agent that forms the film and the crosslinkable component itself forming the film hydrophilic. (For example, refer to Patent Documents 1 to 5 below). However, in this case, since the entire resin becomes hydrophilic by selecting a hydrophilic resin or functionalizing the resin or crosslinkable component, the resin or crosslinkable component that can be used is limited depending on the application of the coating. The Further, as a result of imparting hydrophilicity to the coating agent, the entire coating becomes hydrophilic, so that moisture can easily enter the coating and there is a concern about the durability of the coating itself. In this way, when existing coating agents are improved and hydrophilicity is imparted to them, it is necessary to improve the resin and crosslinkable components that form the coating film. Necessary.

  As another method for imparting hydrophilicity to the film, there is a case where hydrophilicity is imparted by coating the above-mentioned hydrophilic coating agent on the coating film formed by the existing coating agent to form a film. . However, in this case, since the film is a hydrophilic film separated (laminated) from a coating film formed by an existing coating agent, it is difficult to obtain weather resistance due to film delamination due to delamination. In addition, since the coating is gradually peeled off, the surface shape of the coating changes, resulting in poor appearance such as gloss reduction. In recent years, there are many requests to make the baking paint hydrophilic, and its uses include outdoor installation storage, roof pre-coated metal, and the like. These coatings are required to have long-term weather resistance.

  On the other hand, as a technique for imparting hydrophilicity to the film without changing the resin or the crosslinkable component, there is a case where a hydrophilic surface conditioner is added to an existing coating agent. In this case, by adding a small amount of a hydrophilic surface conditioner, the coating surface can be hydrophilized without changing the physical properties required of the coating, such as the durability and hardness of the formed coating. As the hydrophilic surface conditioner, in many cases, silicates represented by ethyl silicate that exhibits hydrophilicity by hydrolysis are often used. Since silicates require approximately 2-3 months to hydrolyze on the surface of the film, the film becomes a hydrophobic surface due to the unhydrolyzed silicates immediately after the film is formed, so that lipophilic soil adheres to it. It ’s easy to do. Hydrolysis of silicates allows long-term hydrophilic expression after hydrophilic expression, but long-term hydrophilicity may cause moisture to gradually enter the film and reduce the durability of the film itself. is there. Furthermore, as a problem of coating agents containing hydrophilic surface conditioners such as silicates, there are problems from the viewpoint of stability over time such as gelation of hydrophilic surface conditioners themselves and thickening of coating agents by crosslinking with resins. Is likely to occur. The hydrophilic surface conditioner itself may be hydrolyzed by moisture in the air and become highly polar, losing the surface orientation due to the hydrophobicity of the silicates, and reducing the hydrophilization performance.

  As a hydrophilic surface conditioner that develops hydrophilicity from the initial stage of film formation, there is one containing a polyalkylene oxide that is a hydrophilic segment. A coating agent containing such a hydrophilic surface conditioner is relatively suitable for forming a film at room temperature. However, when a film is formed by baking at a high temperature like a baking paint, the heat resistance of polyalkylene oxide is reduced. There is a tendency to lower the hydrophilic expression performance, which is considered to be thermal decomposition or hydrolysis from the low level. In addition, since the hydrophilic surface conditioner can easily stabilize the foam in the coating agent, fine bubbles entrained during the coating of the coating agent may cause bubbles to be removed during baking.

  Patent Document 6 listed below discloses a hydrophilic surface conditioner having a hydrophilic organofunctional silicone polymer obtained by radical polymerization of a silicone macromonomer such as a siloxy group-containing acrylate, an unsaturated polyether component, and acrylamides. Is described. This hydrophilic surface conditioner needs to contain 30% or more of a polyether component in the polymer. The coating agent containing the hydrophilic surface conditioner easily causes thermal decomposition of the polyether component in the high-temperature baking process, and the scattered decomposition product contaminates equipment such as a baking furnace. In addition, the coating formed with this coating agent has a hydrophobic silicone part and a hydrophilic polyether part, so that it becomes a highly polar amphiphile skeleton, which makes it easier to stabilize the bubbles in the coating agent and generate flares. Easy to do.

  Even if these surface conditioners and further antifoaming agents are added to the coating agent, there may be a problem with the film formed by the coating agent. The occurrence of wrinkles not only greatly impairs the appearance of the film, but also damages the film from the defective part and the protective effect of the substrate. Thus, according to the coating agent containing the conventional hydrophilic surface conditioner, even if hydrophilicity can be expressed in the formed film from the beginning, it is very difficult to completely prevent the crack.

JP-A-5-179145 Japanese Patent Laid-Open No. 7-196977 JP-A-9-31401 JP 2002-80789 A JP-A-4-370176 Special table 2008-542462 gazette

  The present invention has been made to solve the above-mentioned problems, and by adding a small amount to a coating agent such as a paint for forming a film, it prevents hydrophilicity and imparts hydrophilicity to the smoothly formed film surface. As a result, a surface conditioner capable of imparting antifouling property, a coating agent, and a film formed by applying and curing the surface preparation agent are provided.

（式（Ｉ）中、Ｒ^１は水素原子又はメチル基、Ｒ^２は炭素数１〜１０のアルキレン基、Ｒ^３は炭素数１〜１２のアルキル基、ｍは２〜１５０の数を示す。）で表わされる片末端（メタ）アクリル変性のシロキシ基含有モノ（メタ）アクリレートモノマー０．０１〜２０．００重量部、並びに、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、２−ヒドロキシブチル（メタ）アクリレート、４−ヒドロキシブチル（メタ）アクリレート、２−ヒドロキシ−３−フェノキシプロピル（メタ）アクリレート、又は水酸基を有する（メタ）アクリレートにε-カプロラクトンを付加したモノマーである水酸基含有（メタ）アクリレート類と、Ｎ−ヒドロキシエチルアクリルアミド、又はＮ−ヒドロキシメチルアクリルアミドである水酸基含有（メタ）アクリルアミド類と、エチルアルコール、イソプロピルアルコール、カプロラクタム、メチルエチルケトン−オキシム、ジメチルピラゾール、及びマロン酸ジエチルから選ばれるブロック剤を反応させたもので前記ブロック剤でブロック化されたイソシアネート基を有する（メタ）アクリレートモノマーであるブロックイソシアネート基含有（メタ）アクリレート類とから選ばれる少なくとも何れかの官能基含有モノマーを最大で１０重量部のうち、
少なくとも前記アクリルアミドモノマーと前記シロキシ基含有モノ（メタ）アクリレートモノマーとが共重合され重量平均分子量を１５００〜５００００とする共重合物を含有しており、被膜表面に親水性を付与することを特徴とする。 The surface conditioning agent according to claim 1, which has been made to achieve the above object, includes dimethyl (meth) acrylamides which are N, N-dimethylacrylamide , and N, N-diethylacrylamide. in a diethyl (meth) at least one acrylamide monomer from 80.00 to 99.99 parts by weight selected from acrylamides, following chemical formula (I)

(In the formula (I), ^{R 1} represents a hydrogen atom or a methyl group, ^{R 2} is an alkylene group having 1 to 10 carbon atoms, ^{R 3} is an alkyl group having 1 to 12 carbon atoms, m is a number of 2 to 150. 0.01 to 20.00 parts by weight of a mono (meth) acrylate-modified mono (meth) acrylate monomer modified with one end (meth) acrylic represented by 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate , 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, or a monomer obtained by adding ε-caprolactone to (meth) acrylate having a hydroxyl group and a hydroxyl group-containing (meth) acrylates, N- hydroxyethyl acrylamide, or N- hydroxy And a hydroxyl group-containing (meth) acrylamides is chill acrylamide, ethyl alcohol, isopropyl alcohol, caprolactam, methyl ethyl ketone - oxime, dimethylpyrazole, and is blocked by the blocking agent blocking agent selected from diethyl malonate in that reacted of most 10 parts by weight of at least one functional group-containing monomer selected from the blocked isocyanate group-containing (meth) acrylates are (meth) acrylate monomer having an isocyanate group was,
At least the acrylamide monomer and the siloxy group-containing mono (meth) acrylate monomer are copolymerized to contain a copolymer having a weight average molecular weight of 1500 to 50000, and impart hydrophilicity to the coating surface. To do.

  The coating agent according to claim 2 contains the surface conditioner according to claim 1 and a film-forming component.

  The film according to claim 3 is the coating agent according to claim 2, and is formed by being applied onto a substrate and cured.

  A film according to a fourth aspect is the film according to the third aspect, and is characterized by having an antifouling property on the surface of the film due to the hydrophilicity.

According to the surface conditioner of the present invention, just by adding a small amount to the coating agent, it is possible to impart hydrophilicity to the surface of the coating immediately after the coating is formed without requiring a reaction such as hydrolysis, thereby reducing the water contact angle and rainwater. It is possible to improve the detergency with water such as antifouling property.
In addition, the coating agent of the present invention containing this surface conditioner is excellent in storage stability without any change in performance of the surface conditioner during storage and / or viscosity change of the coating agent due to the surface conditioner. . Furthermore, defoaming / breaking of bubbles by the antifoaming agent blended in the coating agent is promoted, prevention of cracking is achieved, and a smooth film can be formed.
The coating film formed with this coating agent has hydrophilicity on the surface, is smooth, and has excellent top coating characteristics, and has excellent heat resistance with no occurrence of repellency or unevenness during baking.

  Hereinafter, although the form for implementing this invention is demonstrated in detail, the scope of the present invention is not limited to these forms.

  The surface conditioning agent of the present invention includes dimethyl (meth) acrylamides such as N, N-dimethylacrylamide and N, N-dimethylmethacrylamide, and diethyl such as N, N-diethylacrylamide and N, N-diethylmethacrylamide. It contains a copolymer of 80.00 to 99.99 parts by weight of at least one acrylamide monomer selected from (meth) acrylamides and 0.01 to 20.00 parts by weight of a siloxy group-containing mono (meth) acrylate monomer. Is. The surface conditioner is used to be added to and contained in various coating agents that are film-forming compositions in order to cure and form a film. When the amount of the acrylamide monomer is less than 80 parts by weight, the obtained surface conditioning agent cannot exhibit sufficient hydrophilicity in the film. In addition, the compatibility with other components blended in the coating agent containing the surface conditioner becomes extremely poor, repelling occurs during coating, and dents are formed on the coating film surface. The leveling property of the top coat to the coated film is deteriorated, and sufficient top coat adhesion cannot be obtained. The acrylamide monomer is preferably 90 to 99 parts by weight and the siloxy group-containing mono (meth) acrylate monomer is preferably 1 to 10 parts by weight.

  In the copolymer of the acrylamide monomer and the siloxy group-containing mono (meth) acrylate monomer, selected from hydroxyl group-containing (meth) acrylates, hydroxyl group-containing (meth) acrylamides, and blocked isocyanate group-containing (meth) acrylates At least any functional group-containing monomer may be copolymerized. This functional group-containing monomer is preferably 10 parts by weight or less based on the total weight of the (meth) acrylamide monomer and the siloxy group-containing mono (meth) acrylate monomer. Thereby, since it reacts with the resin in the paint on the surface of the coating film, the surface conditioner is not easily dissolved out by rainwater, which can advantageously work in antifouling properties. If it is 10 parts by weight or more, the original performance may be impaired. These functional group-containing monomers may be used alone or in combination as long as the total weight is not more than the prescribed blending amount.

  The weight average molecular weight of this copolymer is in the range of 1500 to 50000. When the weight average molecular weight is less than 1500, a foam problem is likely to occur when a copolymer-containing coating agent is applied. On the other hand, when the weight average molecular weight exceeds 50000, the orientation to the coating surface is lowered and sufficient hydrophilicity cannot be obtained. It is preferable that the weight average molecular weight of a copolymer is 2500-20000.

（式（Ｉ）中、Ｒ^１は水素原子、又はメチル基、Ｒ^２は炭素数１〜１０のアルキレン基、Ｒ^３は炭素数１〜１２のアルキル基、ｍは２〜１５０の正数を示す。） As the siloxy group-containing mono (meth) acrylate monomer, a one-terminal (meth) acryl-modified siloxy group-containing mono (meth) acrylate monomer represented by the following chemical formula (I) is used.

(In Formula (I), R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 1 to 10 carbon atoms, R ³ is an alkyl group having 1 to 12 carbon atoms, and m is a positive number of 2 to 150. Show.)

  Siloxy group-containing mono (meth) acrylate monomers represented by the chemical formula (I) are, for example, Silaplane FM-0711, Silaplane FM-0721, Silaplane FM-0725 (product name of Chisso Corporation; Silaplane) Are registered trademarks of Chisso Corporation, X-22-174DX, X-22-2426, X-22-2475 (the product name of Shin-Etsu Chemical Co., Ltd.).

  Acrylamide monomers are dimethyl (meth) acrylamides and diethyl (meth) acrylamides, for example, DMAA which is N, N-dimethylacrylamide, DEAA which is N, N-diethylacrylamide (product name of Kojin Film & Chemicals Co., Ltd.) ).

Examples of the hydroxyl group-containing (meth) acrylates include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy- Examples thereof include 3-phenoxypropyl (meth) acrylate and monomers obtained by adding ε-caprolactone to (meth) acrylate having a hydroxyl group (for example, Plaxel FM series).
Examples of the hydroxyl group-containing (meth) acrylamides include N-hydroxyethyl acrylamide and N-hydroxymethyl acrylamide.
Blocked isocyanate group-containing (meth) acrylates are (meth) acrylate monomers having an isocyanate group blocked with a blocking agent. For example, 2-isocyanatoethyl (meth) acrylate is blocked with ethyl alcohol, isopropyl Examples include those obtained by reacting alcohol, caprolactam, MEK-oxime, dimethylpyrazole, diethyl malonate, and the like.

  In the copolymer of the acrylamide monomer and the siloxy group-containing mono (meth) acrylate monomer, at least one unsaturated monomer selected from alkyl (meth) acrylates, (meth) acrylamides and vinyl group-containing compounds is present. It may be copolymerized. However, the copolymerization amount of the unsaturated monomer should be such that the obtained copolymer does not impair the hydrophilicity-imparting performance, and is the total weight of the acrylamide monomer and the siloxy group-containing mono (meth) acrylate monomer. However, it is preferably 30% by weight or less.

  The alkyl (meth) acrylates are, for example, alkyl acrylates or alkyl methacrylates, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n- Butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl ( (Meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 2-acryloyloxyethyl-succinic acid, 2-acryloyloxyethyl-phthalic acid, tet Tetrahydrofurfuryl (meth) acrylate, and the like.

  (Meth) acrylamides are other than dimethyl (meth) acrylamides and diethyl (meth) acrylamides, such as dimethylaminopropyl (meth) acrylamide, isopropyl (meth) acrylamide, (meth) acryloylmorpholine, diacetone acrylamide, (Meth) acrylamide-tert-butylsulfonic acid, (meth) acrylamide-tert-butylsulfonic acid organic salt, (meth) acrylamide-tert-butylsulfonic acid inorganic salt, and the like.

  Examples of vinyl group-containing compounds include linear, branched or cyclic alkyl vinyl ether monomers having 1 to 12 carbon atoms such as n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, cyclohexyl vinyl ether, and lauryl vinyl ether; And vinyl ester monomers such as vinyl, vinyl propionate and vinyl laurate.

  This copolymer can be obtained by a radical polymerization method. In the radical polymerization method, a predetermined amount of at least one acrylamide monomer selected from dimethyl (meth) acrylamide and diethyl (meth) acrylamide, a predetermined siloxy group-containing mono (meth) acrylate monomer, and a predetermined amount as required At least one functional group-containing monomer selected from hydroxyl group-containing (meth) acrylates, hydroxyl group-containing (meth) acrylamides, and blocked isocyanate group-containing (meth) acrylates, and, if necessary, a predetermined amount of alkyl At least one unsaturated monomer selected from (meth) acrylates, (meth) acrylamides and vinyl group-containing compounds is randomly selected in a solvent, optionally in the presence of a radical polymerization initiator, and optionally a chain transfer agent. It can be obtained by copolymerization. As the radical polymerization initiator, for example, tert-butylperoxy-2-ethylhexanoate can be used, and as the chain transfer agent, for example, dodecyl mercaptan can be used. Further, as the solvent, for example, an inert solvent such as cyclohexanone can be used. The copolymer may be obtained by radical polymerization or may be obtained by ionic polymerization such as anionic polymerization. The copolymer may be a random copolymer, a block copolymer, a graft copolymer, or an alternating copolymer.

  The obtained surface conditioning agent containing the copolymer may be composed only of the copolymer, or may be used by dissolving or suspending the copolymer in an inert solvent. An inert solvent is one that can dissolve or suspend the copolymer. Specifically, hydrocarbon solvents such as xylene, toluene and cyclohexane; ketone solvents such as cyclohexanone and methyl isobutyl ketone; methyl cellosolve, cellosolve, butyl cellosolve, methyl carbitol, carbitol, butyl carbitol, diethyl carbitol, propylene Ether solvents such as glycol monomethyl ether; ester solvents such as n-butyl acetate, isobutyl acetate, n-amyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate; n-butyl alcohol, sec-butyl Examples include alcohol solvents such as alcohol, isobutyl alcohol, cyclohexanol, 2-ethylhexanol, and 3-methyl-3-methoxybutanol. These solvents may be used alone or in combination of two or more.

  The coating agent contains a surface conditioner and a film forming component. When preparing a coating agent by blending this surface conditioner, after preparing a known coating agent containing no surface conditioner and containing a film-forming component in advance, blending the surface conditioner and kneading to obtain a desired coating agent A coating agent is obtained. They may be mixed simultaneously or in any order. The coating agent is preferably blended with a surface conditioner so as to be a copolymer of 0.1 to 10% by weight, preferably 0.5 to 5.0% by weight in terms of solid content with respect to the total amount of the coating agent. The coating agent may contain a third component other than the film forming component and the inert solvent. The third component is not particularly limited, and examples thereof include colorants such as pigments and dyes, resins, diluent solvents, catalysts, and surfactants. Moreover, a sensitizer, an antistatic agent, an antifoamer, a dispersing agent, and a viscosity modifier may be blended as necessary.

  Examples of the resin that is a film forming component blended in the coating agent include acrylic resins, polyester resins, urethane resins, alkyd resins, epoxy resins, and polyamine resins. This resin is, for example, in the presence of a catalyst, such as heat curable, ultraviolet curable, electron beam curable, oxidation curable, photocationic curable, peroxide curable, and acid / epoxy curable. It may be one that cures with a chemical reaction in the absence, or it may be a resin having a high glass transition point that does not involve a chemical reaction and forms a film only by volatilization of the solvent.

  The dilution solvent is not particularly limited as long as it is a commonly used water or organic solvent. Examples of the organic solvent include hydrocarbon solvents such as xylene, toluene and cyclohexane; ketones such as cyclohexanone and methyl isobutyl ketone. Solvent; ether solvent such as methyl cellosolve, cellosolve, butyl cellosolve, methyl carbitol, carbitol, butyl carbitol, diethyl carbitol, propylene glycol monomethyl ether; n-butyl acetate, isobutyl acetate, n-amyl acetate, cellosolve acetate, Ester solvents such as propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate; n-butyl alcohol, sec-butyl alcohol, isobutyl alcohol, cyclohexanol, 2- Chill hexanol, alcohol solvents thereof such as 3-methyl-3-methoxybutanol. These solvents may be used alone or in combination.

  The coating agent containing this surface conditioner can be applied to the surface of the substrate, and the resulting coating film can be dried or cured to form a coating having a hydrophilic surface. This coating has an antifouling property that it becomes easy to become familiar with water due to its hydrophilic surface, and even if dust adheres, it is easily washed with water such as rainwater.

  The base material is not particularly limited, but is made of plastic, rubber, paper, wood, glass, metal, stone, cement material, mortar material, ceramic material, home appliances, automobile exterior materials, daily necessities, building materials. Is mentioned.

  Examples of the method for applying the coating agent include spin coating, slit coating, spray coating, dip coating, bar coating, doctor blade, roll coating, and flow coating.

  Thus, the coating formed by applying the coating agent containing the surface conditioner of the present invention to the surface of the substrate and curing is smooth and smooth, and imparts hydrophilicity to the surface immediately after the coating is formed. Accordingly, the detergency with water such as rainwater is improved, and the antifouling property can be expressed. That is, the surface conditioner does not require a reaction such as hydrolysis for imparting hydrophilicity, and can impart a hydrophilic surface immediately after the film formation. Thus, according to the film formed of the coating agent containing the surface conditioner, the formed film surface can be hydrophilized even if a film forming component such as a hydrophobic resin having a low surface tension is used. It is possible to improve wettability at the time of overcoating with a high coating agent, and to improve the smoothness of the topcoat film from the effect. Further, by hydrophilizing the coating surface, as a result, the hydrophilic surface has a low water contact angle with respect to the base material, and the high antifouling property can be expressed by improving the detergency with water such as rainwater. This antifouling property also appears immediately after the coating is formed.

  This surface conditioner is excellent in compatibility with the film-forming component because it is a highly polar amphiphile skeleton at room temperature, as is the case with the hydrophilic organofunctional silicone copolymer described in Patent Document 6 described above. It is difficult to stabilize. The details of the reason are not necessarily clear, but are presumed as follows. This surface conditioner contains a copolymer having acrylamide as a main component. The copolymer has a hydrophobic polysiloxane segment and a segment derived from hydrophilic / hydrophobic acrylamide. Since acrylamide has a hydrophobic part and a hydrophilic part in its structure, a copolymer having a segment derived from dimethyl and / or diethyl (meth) acrylamide becomes a thermosensitive polymer in an aqueous solution. This is also observed when monomers are copolymerized to a certain degree. A polymer containing acrylamide as a main component before and after the temperature-sensitive temperature undergoes a phase change between hydrophilicity and hydrophobicity. Due to this characteristic, the surface conditioner changes from hydrophilic to hydrophobic during the baking process where the cracks occur, and the stabilized bubbles become unstable due to the phase change of the surface conditioner. Defoaming / breaking is promoted and prevention of cracking is achieved. After baking, when the temperature returns to room temperature, the hydrophobicity becomes hydrophilic again, and the formed film has hydrophilicity.

  When a coating agent containing this surface modifier is applied onto a substrate to form a film, the surface modifier also has a high orientation to the interface, and leveling properties are also manifested from the effect of uniform surface tension. There are few defects on the surface of the coating such as uneven coating and skin. In addition, this coating does not cause uneven coating even when it is overcoated, and it adheres firmly without reducing the adhesion between the coating and the topcoat layer, so neither the coating nor the topcoat layer peels off. Good aesthetic appearance. In addition, it has excellent heat resistance even when baked at a high temperature, as in the case of painting a coating agent for pre-coated metal. There is no hindrance to the adhesion of the top coat to the film, and it has excellent durability.

  Examples of preparing the surface conditioner of the present invention are shown in Examples 1 to 9 below, and examples of preparing the surface conditioner not applicable to the present invention are shown in Comparative Examples 1 to 7.

<Example 1>
100 parts by weight of cyclohexanone was added to a 1000 mL reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen gas inlet, and the temperature was raised to 110 ° C. in a nitrogen gas atmosphere. The temperature of cyclohexanone was maintained at 110 ° C., and a dropping solution (a-1) shown in Table 1 below was dropped at a constant rate over 2 hours using a dropping funnel to prepare a monomer solution. After completion of dropping, the monomer solution was heated to 115 ° C. and reacted for 2 hours to synthesize a copolymer to obtain a surface conditioner. Using gel permeation chromatography that can separate molecules with different molecular weights (column is manufactured by Tosoh Corporation, product name TSKGEL SUPERMULTIPORE HZ-M, elution solvent is THF (tetrahydrofuran)), the obtained surface conditioning agent is eluted for each molecular weight. The molecular weight distribution was determined. A calibration curve was previously obtained from a polystyrene standard having a known molecular weight, and the weight average molecular weight of the surface modifier was determined by comparison with the molecular weight distribution of the surface modifier. As a result, the weight average molecular weight of this surface modifier was 3500 in terms of polystyrene.

<Example 2>
Surface adjustment by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-2) in Table 1 below and the dripping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 8000 in terms of polystyrene.

<Example 3>
Surface adjustment was carried out by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-3) in Table 1 below and the dripping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 15000 in terms of polystyrene.

<Example 4>
A surface adjuster was obtained by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-4) in Table 1 below. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 3500 in terms of polystyrene.

<Example 5>
Surface adjustment by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-5) in Table 1 below and the dripping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 8000 in terms of polystyrene.

<Example 6>
A surface adjuster was obtained by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-6) in Table 1 below. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 4500 in terms of polystyrene.

<Example 7>
Surface adjustment by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-7) in Table 1 below and the dripping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 8000 in terms of polystyrene.

<Example 8>
Surface adjustment by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-8) in Table 1 below and the dripping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 2000 in terms of polystyrene.

<Example 9>
Surface adjustment by synthesizing a copolymer in the same manner as in Example 1 except that the dripping solution in Example 1 was changed to (а-9) in Table 1 below and the dripping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Example 1, it was 3500 in terms of polystyrene.

<Comparative Example 1>
100 parts by weight of cyclohexanone was added to a 1000 mL reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen gas inlet, and the temperature was raised to 110 ° C. in a nitrogen gas atmosphere. The temperature of cyclohexanone was maintained at 110 ° C., and a dropping solution (b-1) shown in Table 2 below was added dropwise at a constant rate over 2 hours using a dropping funnel to prepare a monomer solution. After completion of dropping, the monomer solution was heated to 115 ° C. and reacted for 2 hours to synthesize a copolymer to obtain a surface conditioner. Using gel permeation chromatography (column is manufactured by Tosoh Corporation, product name TSKGEL SUPERMULTIPORE HZ-M, elution solvent is THF) that can separate molecules with different molecular weights, the obtained surface conditioning agent is eluted for each molecular weight, and molecular weight The distribution was determined. A calibration curve was previously obtained from a polystyrene standard having a known molecular weight, and the weight average molecular weight of the surface modifier was determined by comparison with the molecular weight distribution of the surface modifier. As a result, the weight average molecular weight of this surface modifier was 3500 in terms of polystyrene. In Comparative Example 1, no acrylamide monomer was added to the monomer solution.

<Comparative example 2>
The dripped solution in Comparative Example 1 was changed to (b-2) in Table 2 below, and a copolymer was synthesized in the same manner as in Comparative Example 1 to obtain a surface conditioner. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Comparative Example 1, it was 10,000 in terms of polystyrene. In Comparative Example 2, the acrylamide monomer in the monomer solution was less than 80 parts by weight, and the siloxy group-containing mono (meth) acrylate monomer was more than 20 parts by weight.

<Comparative Example 3>
Surface adjustment by synthesizing a copolymer in the same manner as in Comparative Example 1 except that the dropping solution in Comparative Example 1 was changed to (b-3) in Table 2 below and the dropping temperature was changed to 90 ° C. An agent was obtained. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Comparative Example 1, it was 70000 in terms of polystyrene. In Comparative Example 3, the weight average molecular weight of the obtained surface conditioning agent exceeded 50000.

<Comparative Example 4>
The dripped solution in Comparative Example 1 was changed to (b-4) in Table 2 below, and a copolymer was synthesized in the same manner as in Comparative Example 1 to obtain a surface conditioner. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Comparative Example 1, it was 4000 in terms of polystyrene. In Comparative Example 4, no acrylamide monomer was added to the monomer solution.

<Comparative Example 5>
The dripped solution in Comparative Example 1 was changed to (b-5) in Table 2 below, and a copolymer was synthesized by the same method as in Comparative Example 1 to obtain a surface conditioner. When the weight average molecular weight of the obtained surface conditioning agent was determined by gel permeation chromatography in the same manner as in Comparative Example 1, it was 4000 in terms of polystyrene. In Comparative Example 4, no siloxy group-containing mono (meth) acrylate monomer was added to the monomer solution.

<Comparative Example 6>
Ethyl silicate 48 (manufactured by Colcoat Co.) was used as a surface conditioner.

<Example 10, Comparative Example 8>
The surface coating agent obtained in Examples 1 to 9 and Comparative Examples 1 to 6 was blended with the prepared coating material prepared in advance to obtain a test coating material as a coating agent. The properties of the cured film obtained by applying the test paint to the substrate and the stability over time of the test paint were evaluated.

(Preparation of preparation paint)
Beckolite M-6154-40 (polyester polyol resin, nonvolatile content: 50%, hydroxyl value 50; manufactured by Dainippon Ink & Chemicals, Inc.) 324 parts by weight and CR-93 (titanium oxide manufactured by Ishihara Sangyo Co., Ltd.) 270 parts by weight Glass beads were added to the mill base and stirred for 6 hours with a paint shaker. Further, 594 parts by weight of this mill base, 135 parts by weight of Beckolite M-6154-40 (Dainippon Ink Chemical Co., Ltd.), Super Becamine L-117-60 (Butylated melamine resin, NV 60%, Dainippon Ink) Chemical Industry Co., Ltd.) 22 parts by weight, Super Becamine L-105-60 (Methylated Melamine Resin NV 60%, Dainippon Ink & Chemicals, Inc.) 45 parts by weight and thinner (Solvesso 150 / Cyclohexanone = 50/50) 204 After compounding red parts consisting of parts by weight, the glass beads were separated by filtration to obtain a preparation paint.

(Adjustment of test paint and creation of coating)
In the obtained preparation paint, 0.5% of antifoaming agent (Floren AC-300, manufactured by Kyoeisha Chemical Co., Ltd.) and the surface conditioner 1 obtained in Examples 1-9 and Comparative Examples 1-6 as solid content 0.5% was added and stirred with a lab disper at 2000 rpm for 2 minutes to obtain a test paint which was a baked-on polyester paint. The obtained test paint was immediately applied onto a substrate with a # 42 bar coater, and immediately baked at 245 ° C. for 60 seconds (PMT: 225 ° C.) and cured to form a cured film.
For comparison, a cured film prepared from a test paint obtained using the surface conditioner of Comparative Example 6 was immersed in a 1% aqueous sulfuric acid solution for 24 hours to promote hydrolysis, and a cured film obtained by accelerating the hydrolysis. 7 was used as a cured coating for hydrophilicity comparison.

(Evaluation of armpits on the cured coating)
Table 3 below shows the results obtained by visually counting the number of arms generated per 10 cm ^{2 of the} cured coating and evaluating it according to the following evaluation criteria.
Evaluation criteria for armpit occurrence No armpit occurrence: ◎
Approximately 3 or less: ○
Approximately 7 or less: ○ ～ △
10 or more places: △
Waki occurred on the entire surface: ×

(Evaluation of leveling property of cured coating surface)
The skin state of the coated surface after curing was observed visually, and the results evaluated according to the following evaluation criteria are shown in Table 3 below.
Leveling evaluation criteria Good; ○
Bar coater paint remains slightly: ○ ～ △
Bar coater's paint streaks remain prominent: △
Repelling occurs: ×

(Measurement of water contact angle of cured coating)
0.02 μL of water droplets were dropped on the cured coating surface immediately after curing, and the initial water contact angle was measured using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). The results are shown in Table 3 below. The water contact angle was measured using the cured film of Comparative Example 7 for hydrophilicity comparison.

(Evaluation of actual exposure of cured film)
A coated plate with a cured coating formed on the surface was bent at 45 ° and placed vertically, exposed to the south surface outdoors for 2 months, and the degree of contamination was visually evaluated according to the following evaluation criteria. The results are also shown in Table 3 below.
Evaluation criteria for contamination Almost no contamination and good: ○
Somewhat contaminated: △
Heavy pollution: ×

  As is clear from Table 3, the cured coatings of Examples 1 to 9 have less cracking and better leveling than the cured coatings of Comparative Examples 1 to 6, and the coating surface is smooth. is there. Further, the water contact angles of the cured coatings of Examples 1 to 9 and the stains in the actual exposure test were also similar to the cured coating of Comparative Example 7 for hydrophilicity comparison, and had good hydrophilicity and antifouling properties. Presents.

(Evaluation of stability of test paint over time)
The viscosity (B-type viscometer) of the prepared test paint at the initial stage, 40 ° C. × 1 month and 2 months after storage was measured, and the results are shown in Table 4 below. In addition, for each of the initial stage and after storage at 40 ° C. for 1 month, a cured film was prepared by the above-described film forming method, and the water contact angle was evaluated by the above-described water contact angle measurement method. This is also shown in 4. In Table 4 below, the water contact angles shown in Table 3 are also shown as initial water contact angles.

  As is clear from Table 4, the cured coatings using the test paints of Examples 1 to 9 have good temporal stability and do not thicken or gel. Further, even in the cured coating of the test paint stored at 40 ° C. for 1 month, the water contact angle is substantially the same as the initial water contact angle and exhibits good hydrophilicity. On the other hand, the cured coatings of Comparative Examples 1 to 7 had a high water contact angle or caused a crack and had insufficient surface characteristics.

  The surface conditioner of the present invention is applied to the surfaces of home appliances, automobile exterior materials, daily necessities, and building materials formed of plastic, rubber, paper, wood, glass, metal, stone, cement, mortar, and ceramic materials. It can mix | blend in coating agents, such as a coating material.

Claims (4)

N, N- dimethyl (meth) acrylamides and dimethyl acrylamide, N, at least one acrylamide monomer from 80.00 to 99.99 parts by weight selected from diethyl (meth) acrylamides are N- diethyl acrylamide, following Chemical formula (I)

(In the formula (I), ^{R 1} represents a hydrogen atom or a methyl group, ^{R 2} is an alkylene group having 1 to 10 carbon atoms, ^{R 3} is an alkyl group having 1 to 12 carbon atoms, m is a number of 2 to 150. 0.01 to 20.00 parts by weight of a mono (meth) acrylate-modified mono (meth) acrylate monomer modified with one end (meth) acrylic represented by 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate , 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, or a monomer obtained by adding ε-caprolactone to (meth) acrylate having a hydroxyl group and a hydroxyl group-containing (meth) acrylates, N- hydroxyethyl acrylamide, or N- hydroxy And a hydroxyl group-containing (meth) acrylamides is chill acrylamide, ethyl alcohol, isopropyl alcohol, caprolactam, methyl ethyl ketone - oxime, dimethylpyrazole, and is blocked by the blocking agent blocking agent selected from diethyl malonate in that reacted of most 10 parts by weight of at least one functional group-containing monomer selected from the blocked isocyanate group-containing (meth) acrylates are (meth) acrylate monomer having an isocyanate group was,
At least the acrylamide monomer and the siloxy group-containing mono (meth) acrylate monomer are copolymerized to contain a copolymer having a weight average molecular weight of 1500 to 50000, and impart hydrophilicity to the coating surface. Surface conditioner.   A coating agent comprising the surface conditioning agent according to claim 1 and a film-forming component.   The coating agent according to claim 2, wherein the coating agent is formed by being applied onto a substrate and cured.   The coating film according to claim 3, wherein the coating film has an antifouling property due to the hydrophilicity.