JP6676380B2 - Method for producing metal carboxylate coating film using deprotection reaction - Google Patents

Description

The present invention relates to a method for producing a metal carboxylate coating film, preferably a method for producing a metal poly (meth) acrylate coating film.

  Today, functional films or sheets in which various functional layers such as a hard coat property, an antistatic property, and a gas barrier property are formed on a film or sheet-like base material are used. One of the materials forming the functional layer is a metal salt of carboxylic acid, particularly a metal salt of (meth) acrylic acid. The metal (meth) acrylate is a compound having an ionic bond between a carboxylate anion and a metal cation, and a property derived from the metal itself. Because it has a water-based dispersant, a raw material for detergents and water-absorbent resins, and because zinc salts have high hardness, high elasticity, and gas barrier properties, rubber for tires and golf balls, and as a raw material for gas barrier films, It's being used. In addition, (meth) acrylates such as magnesium, calcium, copper, and aluminum are available as industrial products or reagents.

Metal poly (meth) acrylate, which is a polymer of metal (meth) acrylate, particularly poly (meth) acrylic polyvalent metal having a polyvalent metal species is mainly used as a gas barrier film. As a method for producing a coating film containing a metal salt of poly (meth) acrylate, a metal compound is added to poly (meth) acrylic acid in the state of a coating solution to neutralize the solution, and the metal salt of poly (meth) acrylate is prepared in advance. There is a method of preparing a solution. This method is not a problem in the case of a monovalent metal compound, but in the case of a polyvalent metal compound, pseudo-crosslinking between a carboxylate and a polyvalent metal ion proceeds as the degree of neutralization increases. Causes insoluble metal poly (meth) acrylate to precipitate.
In order to avoid the above-described problem, Patent Document 1 devises a process. That is, a first polyacrylic acid film is formed on a base film, and a second polyvalent metal compound film is further laminated thereon, and metal ions are diffused under humidification to form a polyacrylate. The coating film of is manufactured. In this case, two coating liquids are required, and the process seems to be complicated.

WO2003 / 091317 pamphlet

  The present invention has been made in view of such circumstances, and by devising a coating solution side instead of a process, a coating film of a metal salt of poly (meth) acrylate, particularly among metal salts of carboxylic acid, can be formed. It is an object of the present invention to provide a method of manufacturing with a liquid.

The object of the present invention is achieved by the following (1) to (6).
(1) A method for producing a coating film containing a metal salt of a carboxylic acid, wherein (A) a carboxylic acid compound in which an acid site is protected, and (B) a metal compound as a coating film forming material for forming the coating film. , (C) a deprotection catalyst, and (D) a material containing a diluting solvent.

  Preferably, the (C) deprotection catalyst is an acid having a pKa of 9 or less and / or a salt thereof, or a deprotection catalyst capable of generating the acid and / or a salt thereof.

A deprotection catalyst having a structure containing a sulfonic acid moiety, a perfluoroalkyl moiety, a perfluorophosphorous moiety and an antimony moiety in a part of its chemical structure is preferred.
(2) The method for producing a coating film according to (1), wherein, after the coating film forming material is applied to a substrate, the formed coating film is heated to generate a metal salt of a carboxylic acid.
(3) The method for producing a coating film according to (1) or (2), wherein, in the process of producing the coating film, the coating film is exposed to wet heat after heating the coating film.
(4) The method for producing a coating film according to any one of (1) to (3), wherein the metal carboxylate is a poly (meth) acrylate metal salt.
(5) The method for producing a coating film according to any one of (1) to (4), wherein the metal compound (B) is a polyvalent metal compound.
(6) The content of the metal compound (B) is an amount necessary for neutralizing the carboxylic acid generated when the deprotection reaction of the carboxylic acid compound having the protected acid site (A) is completed by 10% or more. The method for producing a coating film according to any one of (1) to (5), wherein

  ADVANTAGE OF THE INVENTION According to the manufacturing method of the coating film of this invention, the outstanding productivity improvement effect that the coating film of a poly (meth) acrylate metal salt can be produced with one liquid without using a plurality of coating liquids is obtained. Express.

As described above, the method for producing a coating film of the present invention comprises, as a coating film-forming material, (A) a carboxylic acid compound having an acid site protected, (B) a metal compound, (C) a deprotection catalyst, and (D) dilution. It is characterized by using a material containing a solvent.
Examples of the (A) carboxylic acid compound in which the acid site is protected include poly-t-butyl (meth) acrylate, polymethyladamantyl (meth) acrylate, and maleic anhydride adduct of isoprene, which are esterified with t-butyl alcohol. The present invention is not limited to only such examples. Each may be used alone, or two or more kinds may be used in combination. Preferably, poly-t-butyl (meth) acrylate is used. The poly (meth) acrylate having a protecting group can be synthesized by polymerizing the corresponding monomer (meth) acrylate. One type of (meth) acrylate monomer may be polymerized alone, two or more types may be used in combination, or a (meth) acrylate monomer having no protecting group may be used in combination. May be polymerized.

  Examples of the metal compound (B) include caustic soda, zinc oxide, magnesium oxide, and aluminum oxide, but the present invention is not limited to these examples. Polyvalent metal compounds such as zinc oxide, magnesium oxide and aluminum oxide are preferable to caustic soda which is a monovalent metal compound, and zinc oxide is particularly preferable. Other metal species include calcium, barium, tin, nickel, cobalt, strontium, and the like. One type of metal oxide may be used alone, or two or more types may be used in combination. The amount of the metal compound to be added is preferably an amount necessary to neutralize the carboxylic acid generated at the completion of the deprotection reaction of the carboxylic acid compound (A) in which the acid site is protected by 10% or more. If it is less than 10%, the performance derived from the metal species may not be exhibited.

  The metal compound is preferably fine particles having a particle diameter of 1 μm or less, and is preferably dispersed uniformly in a coating liquid using an ultrasonic homogenizer or the like and used as a suspension.

The deprotection catalyst (C) is not particularly limited as long as it is a compound capable of catalyzing the deprotection reaction of a carboxylic acid compound in which an acid site is protected, but is preferably an acid having a pKa of 9 or less and / or a salt thereof, or A compound capable of generating the acid and / or a salt thereof. Alternatively, it is a deprotection catalyst having a structure including a sulfonic acid moiety, a perfluoroalkyl moiety, a perfluorophosphine moiety, and an antimony moiety in a part of its chemical structure. An acid having a pKa of 9 or less and / or a salt thereof, or a compound capable of generating the acid and / or a salt thereof, and having a sulfonic acid moiety, a perfluoroalkyl moiety, a perfluorophosphorus moiety, an antimony moiety in a part of its chemical structure. Particularly preferred is a deprotection catalyst having a structure containing a site.
An acid having a pKa of 9 or less and / or a salt thereof, or a compound capable of generating the acid and / or a salt thereof will be described in detail.
Examples of the acid having a pKa of 9 or less and / or a salt thereof include, for example, p-toluenesulfonic acid, pyridinium p-toluenesulfonic acid, trifluoromethanesulfonic acid, zinc trifluoromethanesulfonic acid, and the like. It is not something to be done. Examples of the compound capable of generating an acid having a pKa of 9 or less and / or a salt thereof include, for example, San Aid SI-80L and SI-100L (manufactured by Sanshin Chemical Co., Ltd.) which are thermal cationic polymerization initiators. The invention is not limited only to such examples. These deprotection catalysts may be used alone or in combination of two or more. Among these deprotection catalysts, trifluoromethanesulfonic acid, zinc trifluoromethanesulfonate, and San Aid SI-80L are preferred.
The addition amount of the deprotection catalyst is preferably from 0.1 to 5.0% by mass, and particularly preferably from 0.1 to 3.0% by mass, based on the poly (meth) acrylate having a protective group (A). . When the amount is less than 0.1% by mass, the catalyst for the deprotection reaction is insufficient. On the contrary, when the amount is more than 5% by mass, the performance of the obtained coating film may be deteriorated.

As the diluting solvent (D), any solvent can be used as long as it can dissolve the (A) carboxylic acid compound in which the acid moiety is protected and (C) the deprotection catalyst, and examples thereof include ethyl acetate, toluene, and chloroform. However, the present invention is not limited only to such an example. Further, one kind of diluting solvent may be used alone, or two or more kinds may be used in combination. Ethyl acetate is preferred as the diluting solvent.
The amount of the diluting solvent to be added depends on the solubility of the carboxylic acid compound in which the acid moiety used is protected and the deprotecting catalyst in the diluting solvent, but is preferably 20 to 90% by mass, more preferably 20 to 90% by mass, based on the total amount of the composition. It is 50 to 80% by mass.

  In the present invention, the solid content concentration of the composition is 10 to 80% by mass, preferably 20 to 50% by mass. In the present invention, “solid content concentration” means the mass% of components (total amount) other than a diluting solvent and other volatile solvents.

  The composition thus obtained is usually further mixed with other components to form a coating liquid. Details will be described below.

  The coating liquid used in the present invention may contain other polymers (for example, polyvinyl alcohol, polyethylene glycol, polypropylene glycol, chitosan, etc.), glycerin, Viscous agent, inorganic layer compound, dispersant, surfactant, softener, heat stabilizer, antioxidant, oxygen absorber, coloring agent, antiblocking agent, monofunctional monomer, polyfunctional monomer, reactive polymer, polymerization initiation Agents and other metal salts of carboxylic acids.

Examples of the monofunctional monomer include acrylic acid esters such as isobornyl acrylate and 2-hydroxyethyl methacrylate, but the present invention is not limited to such examples.
The amount of the monofunctional monomer to be added is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less with respect to 100 parts by mass of the metal poly (meth) acrylate. Is preferably 0.001 part by mass with respect to 100 parts by mass of the metal poly (meth) acrylate.

  Examples of the polyfunctional monomer include compounds described in Japanese Patent Application No. 2015-165399, but the present invention is not limited only to such examples.

  The addition amount of the polyfunctional monomer is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, based on 100 parts by mass of the metal poly (meth) acrylate. Is preferably 0.001 part by mass with respect to 100 parts by mass of the metal poly (meth) acrylate.

  Examples of the reactive polymer include urethane acrylate, epoxy acrylate, polyester acrylate, and butadiene acrylate, but the present invention is not limited to such examples.

The amount of the reactive polymer to be added is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, particularly preferably 10 parts by mass or less, based on 100 parts by mass of the metal poly (meth) acrylate. Is preferably 0.001 part by mass with respect to 100 parts by mass of the metal poly (meth) acrylate.
Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator. The thermal polymerization initiator also includes an azo compound and a peroxide activated by irradiation with ionizing radiation.
Examples of the photopolymerization initiator include the compounds described in Japanese Patent Application No. 2015-165399, but the present invention is not limited to these examples.

When these photopolymerization initiators are added to the curable composition, they are usually added to the curable composition at a ratio of 0.001 to 10% by mass, preferably 0.01 to 5% by mass. General-purpose additives such as other sensitizers and light stabilizers may be added together with the photopolymerization initiator.
In the case of performing thermal polymerization, it is preferable to use a thermal polymerization initiator which dissociates thermally and exhibits a function as an initiator. Examples of the thermal polymerization initiator include the compounds described in Japanese Patent Application No. 2015-165399, but the present invention is not limited to such examples.
When a thermal polymerization initiator is used, it is added to the curable composition at a ratio of usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass.
Other metal carboxylate salts include zinc acetate, zinc succinate, zinc (meth) acrylate, and the like, but the present invention is not limited to these examples.

  The coating film of the present invention can be obtained by applying the above-mentioned coating liquid on a sheet-like substrate, heating the coating liquid, and preferably exposing it to moist heat.

The substrate is not particularly limited, but paper and plastic films (including sheets) are preferably used. The substrate is generally used in the form of a film or sheet, but may be a molded article having a three-dimensional shape such as a plastic container, if desired. Other substrates include a glass plate, a metal plate, and aluminum foil. The substrate used to apply the curable composition of the present invention functions as a coating support.
Examples of the type of plastic constituting the base plastic film include plastics described in Japanese Patent Application No. 2015-165399, but the present invention is not limited to such examples.
As the substrate, an unstretched film or stretched film made of these plastics is preferable. The plastic film may be subjected to a pretreatment such as etching, corona discharge, plasma treatment, or electron beam irradiation, or may be pre-coated with an adhesive, if necessary. Inorganic substances such as silicon oxide, aluminum oxide, aluminum and silicon nitride; thin films such as metal compounds formed on the surface of a plastic film by vapor deposition, sputtering, or ion plating can be used as a base material. it can. The surface of the plastic film used as the base material may be printed. The plastic film may be a multilayer film composed of a plurality of plastic films or a laminated film with another material such as paper.

In order to apply the coating liquid of the present invention onto a substrate, an arbitrary coating method such as a spraying method, a dipping method, an application method using a coater, a printing method using a printing machine is used on one or both surfaces of the substrate. can do. When applying using a coater or a printing machine, for example, plastics described in Japanese Patent Application No. 2015-165399 may be mentioned, but the present invention is not limited to such examples.
In the present invention, a metal salt of poly (meth) acrylic acid is generated by applying the coating liquid on a substrate and then heating the formed film. The mechanism is not clear, but heating the formed film volatilizes the diluting solvent, and at the same time, the deprotection reaction of poly (meth) acrylate progresses, and the resulting poly (meth) acrylic acid and metal It is presumed that a metal salt of poly (meth) acrylic acid is generated as the neutralization reaction with the compound proceeds. Further, it is presumed that, by exposing the coating film to heat and humidity after heating, diffusion of metal species in the coating film becomes active and the neutralization reaction is accelerated.
The heating conditions depend on the type of the protecting group and the catalytic ability of the deprotection catalyst, but it is preferable that the heating be performed at a temperature of 100 ° C to 200 ° C and for a time of several seconds to 120 minutes. If the temperature is lower than 100 ° C., much time is required for the deprotection reaction, while if it is higher than 200 ° C., the plastic film as a base material may be damaged. From the viewpoint of mass productivity, the heating time is preferably several seconds to 10 minutes. In addition, ionizing radiation such as UV light or an electron beam may be applied as long as the effects of the present invention are not impaired. Examples of the ionizing radiation include the types described in Japanese Patent Application No. 2015-165399 and the irradiation method, but the present invention is not limited to such examples.

Further, post-heating may be performed at room temperature to 100 ° C. for several minutes to two weeks for curing.
The thickness of the cured film is preferably adjusted so as to be usually in the range of 0.001 μm to 1 mm, preferably 0.01 to 100 μm, and more preferably 0.1 to 10 μm.

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.
1. Preparation of poly-t-butyl methacrylate (Preparation Example 1)
To a 500 mL separable flask equipped with a cooling tube, a temperature sensor, a nitrogen blowing tube, and a stirring blade, 10 g of t-butyl methacrylate (trade name “TBMA” manufactured by Mitsubishi Rayon) and 85 g of ethyl acetate were added, and 100 mL of nitrogen was added. / Min while stirring. The mixture was heated in a water bath, and when the internal temperature reached 55 ° C., 0.1 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), a polymerization initiator, was dissolved in 5 g of ethyl acetate in advance. The prepared solution was added, and the polymerization reaction was started. The reaction was carried out for 120 minutes while adjusting the hot water bath so that the internal temperature became 60 ° C. The molecular weight of the obtained poly-t-butyl methacrylate was Mn6700 and Mw13800.
2. Preparation of Coating Solution To a sample bottle, 2 g of an ethyl acetate solution of poly-t-butyl methacrylate (nonvolatile content: 10%) and 0.057 g of zinc oxide fine particles (CI chemical, particle size: 38 nm) were added. The zinc oxide fine particles were dispersed using an ultrasonic homogenizer to form a suspension. Further, 0.012 g of thermal cationic polymerization initiator SI-80L (Sanshin Chemical) was added and dissolved to obtain a coating liquid.
3. Preparation of Coating Film The coating liquid was applied on a silicon substrate, and then heated on a hot plate at 160 ° C. for 2 minutes. It was further exposed to an environment of 85 ° C. and 85% for 3 hours to obtain a coating film.
4. Confirmation of Deprotection Reaction Progress The deprotection reaction was confirmed by a FT-IR transmission method using a silicon plate. That is, as the deprotection reaction progresses, the peak around 1730 cm ^-1 due to the carboxylic acid ester and the peak around 840 cm ^-1 due to the t-butyl group decrease, and 1690 cm ^-1 due to the carboxylic acid instead. broad peak peaks and 3000~3500cm around ^-1 around ^-1 was identified using increasing.
5. Confirmation of Neutralization Reaction Progress The neutralization reaction was confirmed by an FT-IR transmission method using a silicon plate. That is, as the neutralization reaction proceeds, decreases the peak around 1690 cm ^-1 due to carboxylic acid, peak near 1560 cm ^-1 attributable to a carboxylic acid metal salt was identified using increasing instead .
First, a deprotection catalyst was selected using a coating solution containing no zinc oxide fine particles.
Table 1 shows the results. It is found that phenol having a pKa of 9 or more does not work as a deprotection catalyst (Production Example 1). In addition, since trifluoromethanesulfonic acid is a super strong acid, it is presumed that the deprotection reaction proceeds at room temperature in a solution state and the solution becomes cloudy (Production Example 2).

〇：脱保護反応が５０％以上進行
△：脱保護反応が０〜５０％進行
×：脱保護反応が進行しない
次に、酸化亜鉛微粒子を含有する塗工液にて脱保護反応および中和反応の確認を行った。結果を表２に示す。被膜を加熱することによって脱保護反応および中和反応を進行させることができた。また、加熱後に湿熱下にさらすことで、中和反応が促進した（製造例１０〜製造例１６）。脱保護触媒としてサンエイドＳＩ−８０Ｌを用いて作製した塗膜の中和度は９８％であった（製造例１５）。

〇: Deprotection reaction progresses 50% or more △: Deprotection reaction progresses 0 to 50% X: Deprotection reaction does not progress Next, deprotection reaction and neutralization reaction in a coating solution containing zinc oxide fine particles Was confirmed. Table 2 shows the results. By heating the coating, the deprotection reaction and the neutralization reaction were able to proceed. In addition, the neutralization reaction was accelerated by exposing it to moist heat after heating (Production Examples 10 to 16). The degree of neutralization of the coating film produced using Sun-Aid SI-80L as the deprotection catalyst was 98% (Production Example 15).

＜脱保護反応＞
〇：脱保護反応が５０％以上進行
△：脱保護反応が０〜５０％進行
×：脱保護反応が進行しない
＜中和反応＞
〇：中和反応が２０％以上進行
△：中和反応が０〜２０％進行
×：中和反応が進行しない

表１及び表２の結果から本発明の効果を確認できた。

<Deprotection reaction>
〇: Deprotection reaction progresses 50% or more △: Deprotection reaction progresses 0 to 50% ×: Deprotection reaction does not progress <Neutralization reaction>
〇: Neutralization reaction progresses 20% or more 以上: Neutralization reaction progresses 0 to 20% x: Neutralization reaction does not progress

The effects of the present invention were confirmed from the results in Tables 1 and 2.

  That is, by the production method of the present invention, a polyzinc methacrylate film could be produced with one liquid.

  The production method of the present invention is suitable as a method for producing a coating film of a metal carboxylate, particularly a film of a metal poly (meth) acrylate. Further, the coating film obtained by the production method of the present invention is expected to be used for, for example, a paint, a gas barrier material, a hard coat material and the like.

Claims (6)

A method for producing a coating film containing a metal salt of a carboxylic acid, wherein (A) a carboxylic acid compound having an acid site protected, (B) a metal compound, and (C) a coating film forming material for forming the coating film. A) a deprotection catalyst which is an acid having a pKa of 9 or less and / or a salt thereof, or a compound capable of generating the acid and / or a salt thereof, or a sulfonic acid moiety, a perfluoroalkyl moiety, a perfluorophosphorus moiety in a part of the chemical structure , A deprotection catalyst having a structure including one of an antimony moiety or a sulfonic acid moiety and a perfluoroalkyl moiety, and (D) using a material containing a diluting solvent and not containing an epoxy group-containing resin. Characteristic coating film manufacturing method. The method for producing a coating film according to claim 1, wherein the coating film forming material is applied to a substrate, and then the formed coating film is heated to generate a metal salt of a carboxylic acid. The method for producing a coating film according to claim 1, wherein, in the process of producing the coating film, the coating film is exposed to wet heat after heating the coating film. The method according to claim 1, wherein the metal carboxylate is a metal poly (meth) acrylate. The method for producing a coating film according to any one of claims 1 to 4, wherein the metal compound (B) is a polyvalent metal compound. The content of the metal compound (B) is an amount necessary to neutralize the carboxylic acid generated when the deprotection reaction of the carboxylic acid compound having the protected acid site (A) is completed by 10% or more. The method for producing a coating film according to any one of claims 1 to 5, characterized in that: