WO2019107350A1

WO2019107350A1 - Coating material composition and hydrophilic member

Info

Publication number: WO2019107350A1
Application number: PCT/JP2018/043563
Authority: WO
Inventors: 大貴加藤; 真利子植村; 小林　信幸; 三木　慎一郎
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-12-01
Filing date: 2018-11-27
Publication date: 2019-06-06
Also published as: CN111433293A; SG11202004982XA; MY193437A; CN111433293B; JP6388185B1; JP2019099669A

Abstract

The coating material composition according to the present invention includes a first monomer having a bifunctional (meth)acryloyl group and repeating units of an ethylene oxide group in each molecule thereof, and a second monomer having a monofunctional or higher hydroxyl group and a trifunctional or higher (meth)acryloyl group in each molecule thereof. The number of repeating units of the ethylene oxide group in the first monomer is 18-40. When the total of the content of the first monomer and the second monomer is defined as 100% by mass, the content of the first monomer is 40%-95% by mass, and the content of the second monomer is 5%-60% by mass. The content of the first monomer with respect to total solid content is 40%-85% by mass, and the content of the second monomer with respect to total solid content is 10%-55% by mass.

Description

Coating composition and hydrophilic member

The present invention relates to a paint composition and a hydrophilic member. In particular, the present invention relates to a coating composition and a hydrophilic member capable of forming a coating having antifogging properties.

For example, when the surface temperature of the mirror becomes low in winter in a mirror of a wash basin or the like, water vapor in the air may cause condensation on the surface of the mirror, which may cause fogging of the mirror. Various methods have been proposed to eliminate such fogging.

For example, Patent Document 1 describes that a hard coat or a cured coating film excellent in electrostatic property and antifogging property is formed by applying the composition to the surface of a synthetic resin molded product and curing the composition. .

The composition of Patent Document 1 is described to contain a polyfunctional monomer (A) having three or more (meth) acryloyl groups and a monofunctional or difunctional monomer (B). Examples of the monomer (B) include polyethylene glycol mono (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, polyethylene glycol (meth) acrylate, and polypropylene glycol di (meth) acrylate.

Further, the composition of the example in Patent Document 1 contains 25 parts by mass of PE-4A and 30 parts by mass of PE-3A as monomer (A), and 15 parts by mass of predetermined polyethylene as monomer (B). It is stated that glycol diacrylate is included. PE-4A is pentaerythritol tetraacrylate, and PE-3A is pentaerythritol triacrylate.

JP-A-5-214044

According to Patent Document 1, a cured coating film obtained by the above composition is considered to be excellent in all of abrasion resistance, abrasion resistance, electrostatic property and antifogging property. However, since a coating film having a higher antifogging property is required in the market these days, even with the above composition, the antifogging property is not sufficient and a coating having an excellent antifogging property There is a need for coating compositions that can form films.

The present invention has been made in view of the problems of the prior art. And the object of the present invention is to provide a paint constituent and a hydrophilic member which can form a coating film excellent in antifogging property.

In order to solve the above problems, the coating composition according to the first aspect of the present invention comprises a first monomer having a repeating unit of ethylene oxide group and a bifunctional (meth) acryloyl group in one molecule; And a second monomer having a trifunctional or more functional (meth) acryloyl group and a monofunctional or more functional hydroxyl group in the molecule. Further, the number of repeating units of ethylene oxide group in the first monomer is 18 to 40. And when the sum total of content of a 1st monomer and a 2nd monomer is made into 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. It is up to 60% by mass. The content of the first monomer with respect to the total solid content is 40% by mass to 85% by mass, and the content of the second monomer with respect to the total solid content is 10% by mass to 55% by mass.

A hydrophilic member according to a second aspect of the present invention includes a base, and a hydrophilic film provided on the base and formed of the above-described coating composition.

[Coating composition]
In Example 3 of Patent Document 1 described above, 25 parts by weight of PE-4A, 30 parts by weight of PE-3A, 25 parts by weight of NVP, 15 parts by weight of 45 EO-DA, 20 parts by weight of EC and HCHPK A composition consisting of 5 parts by weight is described. Here, PE-4A is pentaerythritol tetraacrylate, PE-3A is pentaerythritol triacrylate, and NVP is N-vinyl-2-pyrrolidone. As 45EO-DA, polyethylene glycol diacrylate in which the number of repeating units of ethylene oxide group is 45 is used. EC is ethyl cellosolve and is used as a non-polymerizable solvent, and HCHPK is 1-hydroxycyclohexyl phenyl ketone and used as a photopolymerization initiator.

According to Patent Document 1, a cured coating film obtained by the above composition is considered to be excellent in all of abrasion resistance, abrasion resistance, electrostatic property and antifogging property.

However, since a coating film having a higher antifogging property is required in the market these days, even with the above composition, the antifogging property is not sufficient and a coating having an excellent antifogging property There is a need for coating compositions that can form films.

Here, it is conceivable to increase the number of repeating units of the ethylene oxide group, which is a hydrophilic group, as one of the means for improving the antifogging property of the coating film. However, as described in Patent Document 1, when the number of repeating units of ethylene oxide group is increased too much, not only the antifogging property of the coating film is lowered but electrostatic property, scratch resistance and The abrasion resistance may also be reduced.

Also, in order to improve the antifogging properties of the coating, it is conceivable to increase the content of polyethylene glycol diacrylate such as 45 EO-DA. Here, in Patent Document 1, the content of the monomer (B) in the composition is excellent for the cured coating film to be set in the range of 5 to 30 parts by weight with respect to 100 parts by weight of the composition It is described that it is preferable from the point which can provide antifogging etc., etc.

However, even if the content of polyethylene glycol diacrylate such as 45EO-DA is increased to about 30 parts by mass, sufficient antifogging properties may not be obtained. When the content of polyethylene glycol diacrylate such as 45EO-DA exceeds 30 parts by mass, the hardness and water resistance of the coating may be reduced. In Example 3 of Patent Document 1, PE-4A and PE-3A are considered to correspond to the monomer (A). Further, in Example 3 of Patent Document 1, 45EO-DA is considered to correspond to the monomer (B). Therefore, in Example 3 described above, the content of the monomer (B) is considered to be about 21 mass% when the total of the content of the monomer (A) and the monomer (B) is 100 mass%. Moreover, in the case where the content of the monomer (B) in Example 3 is simply 30 parts by mass, the monomer (B) when the total content of the monomer (A) and the monomer (B) is 100% by mass. The content of is considered to be about 35% by mass.

Accordingly, the coating composition according to the present embodiment includes the first monomer having a repeating unit of ethylene oxide group and a bifunctional or higher functional (meth) acryloyl group in one molecule. Further, the coating composition according to the present embodiment includes a second monomer having a trifunctional or higher functional (meth) acryloyl group and a monofunctional or higher functional hydroxyl group in one molecule. Further, the number of repeating units of ethylene oxide group in the first monomer is 18 to 40. And when the sum total of content of a 1st monomer and a 2nd monomer is made into 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. It is up to 60% by mass.

The coating composition as described above comprises a first monomer that mainly imparts anti-fogging properties to the coating and a second monomer that mainly imparts hardness and water resistance to the coating. And, the number of repeating units of ethylene oxide group in the first monomer is within a predetermined range, and the contents of the first monomer and the second monomer are within the predetermined range. Therefore, the coating composition which concerns on this embodiment can form the coating film excellent in anti-fogging property, hardness, and water resistance by apply | coating and hardening it to a base material. Each component will be described in detail below.

(First monomer)
The paint composition which concerns on this embodiment has a 1st monomer which has a repeating unit of ethylene oxide group, and a bifunctional or more (meth) acryloyl group in 1 molecule. That is, the first monomer has a repeating unit of ethylene oxide group which contributes to the antifogging property, and a bifunctional or more (meth) acryloyl group which contributes to the hardness and water resistance of the coating film by the polymerization reaction. .

The first monomer can impart antifogging properties to the coating film by having a repeating unit of a hydrophilic ethylene oxide group. In addition, since the first monomer of the present embodiment has a repeating unit of ethylene oxide group in one molecule, compared with the case where an antifogging agent is added to the film by adding an additive such as an antistatic agent, It is possible to reduce the effects of bleed out and functional deterioration due to aging.

The ethylene oxide group is represented by a constituent unit of-(CH ₂ CH ₂ O)-. The first monomer has repeating units of ethylene oxide groups _(CH 2 _CH 2 O) in the molecule. Specifically, the number of ethylene oxide group repeating units in the first monomer is 18 to 40. By setting the number of repeating units of the ethylene oxide group to 18 or more, since the chemical structure having hydrophilicity in the coating film is increased, it is possible to absorb water vapor that causes condensation. Therefore, since the irregular reflection due to condensation can be suppressed, the antifogging property of the coating film can be improved. Moreover, the hardness and water resistance of a coating film can be improved by the number of repeating units being 40 or less. From the viewpoint of antifogging property, the number of repeating units of ethylene oxide group is preferably 20 or more, more preferably 22 or more, and still more preferably 23 or more. Further, from the viewpoint of hardness and water resistance, the number of repeating units of the ethylene oxide group is preferably 38 or less, more preferably 36 or less, and still more preferably 35 or less. In addition, the repeating unit of ethylene oxide group may be repeated continuously within 1 molecule, and may be repeated discontinuously and intermittently. The first monomer may be used singly or in combination of two or more. In the present specification, the number of repeating units of ethylene oxide group is calculated by subtracting the molecular weight of chemical structure other than ethylene oxide group from the number average molecular weight M _{n of} the first monomer and dividing the value by the molecular weight of ethylene oxide group Is an integer.

In the first monomer, since the weight average molecular weight M _w tends to be the number average molecular weight M _n or more, the ratio (M _w / M _n ) of the weight average molecular weight M _w to the number average molecular weight M _n is generally Is one or more. The value of M _w / M _n in the first monomer is preferably 1.4 or less, more preferably 1.1 or less. In the present specification, the weight average molecular weight M _w and the number average molecular weight M _n can be measured using gel permeation chromatography (GPC) to calculate polyethylene glycol as a standard sample. Further, when the molecular weight distribution of the first monomer has a plurality of peaks, the weight average molecular weight M _w and the number average molecular weight M _n at each peak can be calculated.

The first monomer has a bifunctional or more (meth) acryloyl group in one molecule. The (meth) acryloyl group is represented by —OCOCH = CH ₂ or —OCOC (CH ₃ ) = CH ₂ and can form a polymer by a polymerization reaction. By setting the (meth) acryloyl group in one molecule to be bifunctional or more, the crosslink density of the polymer forming the coating film can be improved as compared to the case where it is monofunctional. Therefore, the water resistance of the coating film can be improved.

The (meth) acryloyl group possessed by the first monomer is also included if it is a bifunctional, trifunctional and tetrafunctional or higher polyfunctional. However, from the viewpoint of antifogging properties, the (meth) acryloyl group possessed by the first monomer is preferably at least one of bifunctional and trifunctional, and more preferably bifunctional. That is, the first monomer is more preferably di (meth) acrylate. Although the (meth) acryloyl group in the first monomer includes a methacryloyl group and an acryloyl group, it is preferably an acryloyl group from the viewpoint of curing speed.

The first monomer is preferably a monomer having a (meth) acryloyl group at each end of the main chain containing a repeating unit of ethylene oxide group. The ethylene oxide group having 18 to 40 repeating units is preferably contained in the main chain of the first monomer. By using such a first monomer in a paint composition, a coating film excellent in water resistance can be formed. The first monomer is represented by polyethylene glycol di (meth) acrylate represented by the following chemical formula (1), ethylene oxide modified bisphenol A di (meth) acrylate represented by the following chemical formula (2), and the following chemical formula (3) Ethylene oxide modified bisphenol F di (meth) acrylate, ethylene oxide modified hexanediol di (meth) acrylate represented by the following chemical formula (4), and ethylene oxide modified neopentyl glycol di (meta) represented by the following chemical formula (5) ) At least one monomer selected from the group consisting of acrylates can be used.

In the above chemical formulas (1) to (5), R ₁ and R ₂ are each H or CH ₃ , l is an integer of 18 to 40, and m + n is an integer of 18 to 40.

The monomers of the chemical formulas (1) to (5) may be used alone or in combination of two or more. Further, from the viewpoint of antifogging property, the first monomer preferably contains polyethylene glycol di (meth) acrylate represented by the above chemical formula (1).

Moreover, in order to improve the rigidity of a coating film, it is preferable that a 1st monomer contains the (meth) acrylate which has a bisphenol skeleton as shown to said Chemical formula (2) and Chemical formula (3). In addition, it is preferable that a 1st monomer contains the (meth) acrylate which has polyethyleneglycol di (meth) acrylate represented by said Chemical formula (1), and a bisphenol skeleton from an antifogging viewpoint and rigidity viewpoint. Specifically, the first monomer is polyethylene glycol di (meth) acrylate represented by the chemical formula (1), ethylene oxide modified bisphenol A di (meth) acrylate represented by the chemical formula (2), and the above chemical formula It is also preferable to contain at least one of the ethylene oxide-modified bisphenol F di (meth) acrylates represented by (3). Moreover, it is also preferable that the first monomer contains polyethylene glycol di (meth) acrylate represented by the above chemical formula (1) and ethylene oxide modified bisphenol A di (meth) acrylate represented by the above chemical formula (2) .

As a specific example of the first monomer, NK-ester A-1000 (polyethylene glycol # 1000 diacrylate of Shin-Nakamura Chemical Co., Ltd .: in the above chemical formula (1), R ₁ = H, R ₂ = H and l = 23) NK-ester A-BPE-20 (EO (ethylene oxide))-modified bisphenol A diacrylate of Shin-Nakamura Chemical Co., Ltd .: in the above chemical formula (2), R ₁ = H, R ₂ = H and m + n = 20) etc. can be used.

The weight average molecular weight of the first monomer is preferably 800 g / mol to 3000 g / mol, and more preferably 850 g / mol to 2300 g / mol. By setting the weight average molecular weight of the first monomer to such a range, the coating properties of the coating composition can be improved.

The content of the first monomer with respect to the total solid content of the coating composition is preferably 35% by mass to 95% by mass, and more preferably 40% by mass to 85% by mass. By making content of a 1st monomer into said range, the coating composition which can improve the anti-fogging property of a coating film, water resistance, and hardness can be provided.

(Second monomer)
The second monomer has a trifunctional or higher functional (meth) acryloyl group and a monofunctional or higher functionality hydroxyl group in one molecule. That is, the second monomer has a trifunctional or higher functional (meth) acryloyl group which contributes to the hardness and water resistance of the coating film by the polymerization reaction. In addition, the second monomer contributes to the antifogging property of the coating film, and as a hydrogen donor, has a monofunctional or more functional hydroxyl group which contributes to the improvement of the hardness of the coating film by suppressing the reaction inhibition.

The second monomer has a trifunctional or higher (meth) acryloyl group in one molecule. Therefore, since the polymer formed by the polymerization reaction forms a three-dimensional network structure, the hardness and the water resistance of the coating film can be improved as compared with the case where the (meth) acryloyl group having two or less functions is included. it can. The (meth) acryloyl group in the second monomer includes a methacryloyl group and an acryloyl group, but is preferably an acryloyl group from the viewpoint of the curing rate.

The (meth) acryloyl group in the second monomer may be trifunctional or may be tetrafunctional or higher polyfunctional. However, from the viewpoint of suppressing the cure shrinkage, the second monomer preferably has a trifunctional (meth) acryloyl group in one molecule.

The hydroxyl group in the second monomer is not particularly limited as long as it has a monofunctional or more functional hydroxyl group. However, the hydroxyl group in the second monomer is preferably monofunctional.

Specifically, the second monomer more preferably has a trifunctional (meth) acryloyl group and a monofunctional hydroxyl group in one molecule. By using such a 2nd monomer, the coating composition which can form the coating film excellent in anti-fogging property, hardness, and water resistance can be obtained.

As the second monomer, for example, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri (meth) An acrylate etc. are mentioned. These monomers may be used alone or in combination of two or more. Among these, pentaerythritol tri (meth) acrylate is preferably used from the viewpoint of coating properties. As the second monomer, New Frontier (registered trademark) PET-3 (pentaerythritol triacrylate) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. can be used.

The weight average molecular weight of the second monomer is not particularly limited, but is preferably 230 g / mol to 800 g / mol, more preferably 260 g / mol to 600 g / mol, and 200 g / mol to 400 g / mol. Is more preferred. By setting the weight average molecular weight of the second monomer to such a range, the coating properties of the coating composition can be improved.

The content of the second monomer relative to the total solid content of the coating composition is preferably 4% by mass to 60% by mass, and more preferably 10% by mass to 55% by mass. By making content of a 2nd monomer into said range, the coating composition which can improve the anti-fogging property of a coating film, water resistance, and hardness can be provided.

In the present embodiment, when the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 40% by mass to 95% by mass, and the content of the second monomer is It is 5% by mass to 60% by mass. By making content of a 1st monomer and a 2nd monomer into the above ranges, the coating composition which can improve the anti-fogging property of a coating film, water resistance, and hardness can be provided. In addition, when the sum total of content of a 1st monomer and a 2nd monomer is made into 100 mass%, content of a 1st monomer is 45 mass%-85 mass%, and content of a 2nd monomer is 15 mass%. It is more preferable that the content be 55% by mass. When the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 50% by mass to 80% by mass, and the content of the second monomer is 20% by mass It is more preferable that the content is ~ 50% by mass. Moreover, 70 mass% or more is preferable, 80 mass% or more is more preferable, 90 mass% or more is further more preferable, and 95 mass% or more of the total content of the 1st monomer and 2nd monomer with respect to the solid content whole of a coating composition is preferable. Is particularly preferred. In addition, it is preferable that the sum total content of the 1st monomer and 2nd monomer with respect to the whole solid content of a coating composition is less than 100 mass%.

The paint composition according to the present embodiment may further include a third monomer other than the first monomer and the second monomer, in addition to the first monomer and the second monomer, as long as the effects of the present embodiment are not impaired. . Examples of the third monomer include styrene monomers, olefin monomers, vinyl monomers, and acrylic monomers. As a styrene-type monomer, styrene etc. are mentioned, for example. Examples of olefin monomers include ethylene and propylene. Examples of vinyl monomers include vinyl chloride and vinylidene chloride. As an acryl-type monomer, a (meth) acrylate etc. are mentioned, for example. In addition, (meth) acrylate includes acrylate and methacrylate. The above monomer components may be used alone or in combination of two or more. The content of the third monomer in the coating composition is not particularly limited, but is preferably 0.001% by mass to 25% by mass, and more preferably 0.005% by mass to 15% by mass with respect to the total solid content of the coating composition. More preferably, it is mass%.

The third monomer preferably contains (meth) acrylate having at least one of fluorine and polysiloxane in one molecule. These (meth) acrylates tend to localize to the surface after application of the coating composition. Moreover, since these (meth) acrylates can reduce the surface tension of the coating film itself, the surface of the coating film has water repellency and oil repellency. As described above, the paint composition according to the present embodiment has water absorbency because it has the first monomer having hydrophilicity. On the other hand, in the coating composition containing (meth) acrylate having at least one of fluorine and polysiloxane in one molecule, the surface of the coating film has water repellency and oil repellency due to curing. Therefore, even when there is a water content exceeding the water absorption due to the first monomer etc., it is possible to repel water droplets on the surface of the coating film by the water repellent effect of the above-mentioned monomer, so the antifogging of the coating film It is possible to improve the quality. Moreover, the coating film which hardened the coating composition containing the (meth) acrylate which has at least any one of a fluorine and a polysiloxane also has oil repellency. Therefore, by adding (meth) acrylate having at least one of fluorine and polysiloxane to the coating composition, not only the antifogging property but also the antifouling property can be imparted to the coating film.

The addition amount of (meth) acrylate having at least one of fluorine and polysiloxane in one molecule is not particularly limited as long as the effect of the present embodiment is not impaired. In addition, (meth) acrylate which has at least any one of fluorine and polysiloxane in 1 molecule can express the said water repellency and oil repellency with a small amount. Therefore, the content of (meth) acrylate having at least one of fluorine and polysiloxane in one molecule is preferably 0.001% by mass to 5% by mass with respect to the total solid content of the coating composition. And more preferably 0.005% by mass to 1% by mass.

As (meth) acrylate having fluorine in one molecule, trifluoromethyl (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorodecylethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, perfluoro Hexylethyl (meth) acrylate, perfluorobutylethyl (meth) acrylate, perfluoropolyether (meth) acrylate and the like can be mentioned.

In addition, when using (meth) acrylate which has polysiloxane as a 3rd monomer, the surface characteristics of a coating film, such as a slip property and a rough feeling, can also be modify | reformed on the surface of a coating film. Therefore, it is preferable that the coating composition according to the present embodiment further include (meth) acrylate having a polysiloxane. For example, by imparting slip property to the surface of the coating film, the slipperiness of the coating film surface can be improved, and therefore, an index such as pencil hardness can be improved. Moreover, the touch feeling on the surface of a coating film can be improved by giving a smooth feeling to the surface of a coating film.

As (meth) acrylate having polysiloxane in one molecule, a structure having as main skeleton polysiloxane such as polydimethylsiloxane, polydiethylsiloxane, polydiphenylsiloxane, polymethylphenylsiloxane etc. is modified with (meth) acrylate And (meth) acrylates and the like. In addition, as a specific example of (meth) acrylate having polysiloxane in one molecule, for example, Shin-Etsu Silicone (registered trademark) X-22-174 ASX of Shin-Etsu Chemical Co., Ltd. (methacrylate having polydimethylsiloxane (methacrylic modified silicone oil) ) Can be used.

The coating composition of the present embodiment preferably contains a polymerization initiator for promoting the polymerization reaction of the first monomer having a carbon-carbon unsaturated bond and the second monomer. Although the content of the polymerization initiator is not particularly limited, it is preferably 1% by mass to 10% by mass with respect to the total solid content of the coating composition. As the polymerization initiator, although at least one of a photopolymerization initiator and a thermal polymerization initiator can be used, it is preferable to use a photopolymerization initiator. By using the photopolymerization initiator, the first monomer and the second monomer are instantaneously cured by irradiating the active energy ray, so that the manufacturing process can be shortened.

The photopolymerization initiator is a compound having a function of initiating the polymerization reaction of the first monomer and the second monomer, and is a substance that absorbs light of a specific wavelength from active energy rays to be in an excited state to generate radicals or ions. . As such a photopolymerization initiator, for example, at least one selected from the group consisting of benzoin ether type, ketal type, acetophenone type, benzophenone type, and thioxanthone type can be used. As a specific example of the photopolymerization initiator, for example, Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenyl ketone (acetophenone type)) manufactured by BASF, etc. can be used.

The thermal polymerization initiator is a compound having a function of initiating the polymerization reaction of the first monomer and the second monomer, and is a substance which generates active species such as radicals and ions by heating. As the thermal polymerization initiator, at least one selected from the group consisting of azo compounds such as 2,2'-azobis (isobutyronitrile), peroxides such as benzoyl peroxide, benzenesulfonic acid ester and alkyl sulfonium salt It can be used.

The paint composition which concerns on this embodiment may contain the additive which has a various function in the range which does not prevent the effect of this embodiment. As the additives, surfactants, surface property modifiers, durability improvers, colorants, UV absorbers, light stabilizers and the like can be used. These additives may be used alone or in combination of two or more.

The surfactant can be added for the purpose of improving the leveling property and the defoaming property of the coating composition and hydrophilizing the surface of the coating film. The surfactant is not particularly limited, such as nonionic, cationic or anionic, and can be selected according to the application. The surfactant may be chemically bonded to the first monomer or the second monomer to exert the above effect, and the above effect can be obtained by interposing in the polymer without chemically bonding to the first monomer or the second monomer. May be expressed.

The surface property modifier can be added to the coating composition for the purpose of improving the surface property such as touch. As a surface property modifier, a silicone monomer, a fluorine-type monomer, etc. can be added, for example. The surface property modifier can be chemically bonded to, for example, the first monomer or the second monomer to exhibit the above-mentioned effect in the coating film.

Durability improvers can be added to the coating composition to improve the resistance to chemicals, heat and sliding. As the durability improver, for example, a material having a rigid chemical structure such as a benzene ring or a bisphenol structure, or a flexible chemical structure such as an alkane can be used.

Next, the manufacturing method of the paint composition of this embodiment is explained. The coating composition can be prepared by mixing the first monomer and the second monomer and, if necessary, additives. The mixing conditions are not particularly limited, and the mixing can be performed in the air at normal temperature. Also, the order of mixing the first monomer, the second monomer and the additive is not particularly limited.

When mixing the first monomer and the second monomer, it is preferable to add a dispersion solvent to the coating composition and adjust the viscosity so as to facilitate application. As the dispersion solvent for viscosity adjustment, at least one of water and an organic solvent can be used. The organic solvent is not particularly limited, but it is preferable to appropriately select one that is easily volatilized at the time of coating film formation and does not cause curing inhibition or the like at the time of forming a coating film. Examples of the organic solvent include aromatic hydrocarbons (such as toluene and xylene), alcohols (such as methanol, ethanol and isopropyl alcohol), and ketones (such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone). Furthermore, aliphatic hydrocarbons (such as hexane and heptane), ethers (such as tetrahydrofuran), amide solvents (such as N, N-dimethylformamide (DMF) and dimethylacetamide (DMAc), methyl acetate and butyl acetate are mentioned. Be These organic solvents may be used alone or in combination of two or more. Although the addition amount of the dispersion solvent is not particularly limited, it can be, for example, 0.1 part by mass to 500 parts by mass with respect to 100 parts by mass of the coating composition.

As described above, the coating composition according to the present embodiment contains the first monomer having a repeating unit of ethylene oxide group and a bifunctional or more (meth) acryloyl group in one molecule. Further, the coating composition according to the present embodiment includes a second monomer having a trifunctional or higher functional (meth) acryloyl group and a monofunctional or higher functional hydroxyl group in one molecule. Further, the number of repeating units of ethylene oxide group in the first monomer is 18 to 40. And when the sum total of content of a 1st monomer and a 2nd monomer is made into 100 mass%, content of a 1st monomer is 40 mass%-95 mass%, and content of a 2nd monomer is 5 mass%. It is up to 60% by mass.

As described above, the coating composition according to the present embodiment contains the first monomer that mainly imparts antifogging properties to the coating and the second monomer that mainly imparts hardness and water resistance to the coating. . And in this embodiment, the number of the repeating units of the ethylene oxide group in a 1st monomer, and content of a 1st monomer and a 2nd monomer are made into the predetermined | prescribed range. Therefore, according to the coating composition according to the present embodiment, not only the antifogging property of the coating film formed by the coating composition can be improved, but also a coating film excellent in hardness and water resistance can be formed. Therefore, according to the coating composition which concerns on this embodiment, the coating film excellent in anti-fogging property, hardness, and water resistance can be formed.

In addition, since the coating film obtained from the above coating compositions has high hydrophilicity, oil stains can be floated using a large amount of water, and oil stains can be easily removed. Therefore, according to the paint composition concerning this embodiment, it becomes possible to raise antifouling property to oil content.

The coating composition according to the present embodiment has antifogging properties, and thus can be applied to members such as a housing member, a vehicle member, and a crime prevention member. As a member used for these, a mirror, a window glass, a lens, a display etc. are mentioned, for example. Moreover, since the coating film formed using the coating composition which concerns on this embodiment has hydrophilicity, it has the antifouling property with respect to an oil component. Therefore, it can apply also to a member for housings like a kitchen member. Moreover, it can apply also to the sirocco fan and propeller fan which were installed in the range hood of a kitchen.

[Hydrophilic member]
Next, the hydrophilic member according to the present embodiment will be described. The hydrophilic member which concerns on this embodiment is provided with a base material and the hydrophilic film provided on a base material and formed from the said coating material composition. That is, in the hydrophilic member according to the present embodiment, a hydrophilic film (coated film) having hydrophilicity is formed by applying the coating composition to a substrate and curing it.

The substrate is not particularly limited, but at least one of an inorganic substrate made of an inorganic material and an organic substrate made of an organic material can be used. As an inorganic base material, ceramics, such as aluminum, iron, stainless steel, a galvanized steel plate, glass, a enamel, pottery, a slate, an alumina, can be mentioned. Examples of the organic base include plastic materials and sheets such as polycarbonate, acrylic resin, ABS resin (acrylonitrile-butadiene-styrene resin), vinyl chloride resin, epoxy resin, polyester resin, fiber reinforced plastic and the like. Examples of fiber reinforced plastics include carbon fiber reinforced plastics, glass fiber reinforced plastics, SMC (sheet molding compound) and the like.

Moreover, you may use those by which the organic film was coat | covered by these mineral base materials or organic base materials as a base material. As an organic film, the film of an acryl type, polyester type, urethane type, an epoxy type, a melamine type, silicone type, a fluorine type etc. can be mentioned, for example. In order to improve the adhesion between these films and the substrate, the substrate may be subjected to surface treatment such as solvent degreasing, alkaline degreasing, and polishing, and acrylic, epoxy, and silicone primers are used. You may make it apply | coat to a base material as a base layer.

The hydrophilic film is formed by curing the above-mentioned coating composition. The hydrophilic film is formed of a polymer of the first monomer and the second monomer.

In the hydrophilic member, the thickness of the hydrophilic film is not particularly limited, but is preferably, for example, 1 μm to 100 μm, and more preferably 10 μm to 80 μm. When the thickness of the hydrophilic film is in this range, the hardness and the water resistance can be enhanced. In addition, when the thickness of the hydrophilic film is 100 μm or less, it becomes possible to firmly bond to the substrate to suppress peeling.

In the hydrophilic member, the contact angle of water on the surface of the hydrophilic film is preferably 20 ° or less, more preferably 10 ° or less. When the contact angle of water on the surface of the hydrophilic film is 20 ° or less, the hydrophilic film has high hydrophilicity. Therefore, it becomes possible to improve antifogging properties or to easily remove the oil adhering to the surface of the hydrophilic film. The contact angle of water can be measured by the sessile drop method.

Next, the manufacturing method of the hydrophilic member of this embodiment is explained. First, the surface of the substrate is cleaned to remove surface dirt. The cleaning method is not particularly limited, and known methods can be used.

Next, the coating composition described above is applied to the surface of the cleaned substrate. At this time, the method of applying the coating composition is not particularly limited. A coating method and a printing method can be used as a method of apply | coating a coating composition to the main surface of a base material. In the coating method, the coating composition can be applied using an air spray, a brush, a bar coater, a mayer bar, an air knife or the like. The coating composition can also be applied by spin coating. In the printing method, methods such as gravure printing, reverse gravure printing, offset printing, flexographic printing, screen printing and the like can be used.

In addition, after apply | coating a coating composition to the surface of a base material, you may dry-process as needed and may remove the dispersion solvent in a coating composition. The drying conditions are not particularly limited as long as the dispersion solvent is removed, and heat treatment may be performed as necessary.

And when a photoinitiator is used as a polymerization initiator, after apply | coating a coating composition to the surface of a base material, an active energy ray is irradiated and a coating composition is hardened. As an active energy ray irradiated at the time of curing the coating composition, at least one of an ultraviolet ray, an electron beam, an X-ray, an infrared ray, and a visible ray can be used. Among these active energy rays, it is preferable to use an ultraviolet ray or an electron beam from the viewpoint of curability and prevention of resin deterioration.

When curing the coating composition by ultraviolet irradiation, various ultraviolet irradiation devices can be used. As an ultraviolet irradiation device, a xenon lamp, a high pressure mercury lamp, a metal halide lamp, or the like can be used. The irradiation dose of the ultraviolet light is usually 10 to 10000 mJ / cm ² . However, from the viewpoint of enhancing the curability of the composition, the irradiation dose of ultraviolet light is preferably 100 mJ / cm ² or more. In addition, it is preferable to irradiate ultraviolet light under a nitrogen atmosphere so as not to cause curing inhibition by oxygen in the air or the like.

When a thermal polymerization initiator is used as the polymerization initiator, after the coating composition is applied to the surface of the substrate, the coating composition is cured by heating the coating composition. In addition, a heating condition is not specifically limited, It can be set as the temperature which the thermal-polymerization initiator to be used decomposes | disassembles and generate | occur | produces an active species.

As described above, the hydrophilic member of the present embodiment can be produced by applying the coating composition to a substrate and then curing it. Therefore, a hydrophilic member having high hydrophilicity can be obtained by a simple method.

As described above, the hydrophilic member according to the present embodiment includes the base and the hydrophilic film provided on the base and formed of the paint composition. The hydrophilic film has high antifogging properties, hardness and water resistance. Further, since the hydrophilic film has high hydrophilicity, even when oil such as oil stains adheres to the hydrophilic film, water is made to enter between the surface of the hydrophilic film and the oil by contacting the hydrophilic member with water. It can be done. And, since the oil component floats up from the hydrophilic film by the entry of water, the oil component can be easily removed.

As a hydrophilic member, members, such as a member for housings, a member for vehicles, and a crime prevention member, can be mentioned. Specifically, a mirror, a window glass, a lens, a display, etc. are illustrated. Moreover, the hydrophilic member which concerns on this embodiment can also be used for the sheet | seat for greenhouses with which anti-fogging property is required other than the above members, food packaging, etc.

Moreover, the hydrophilic member which concerns on this embodiment is not limited to the use aiming at anti-fogging property, For example, it can be used suitably for the site | part which needs to provide hydrophilicity, such as removal of an oil component. When used for oil removal, examples of hydrophilic members include kitchen members such as range hoods, kitchen storage doors, kitchen counters, sinks, stove tops, kitchen boards, flooring around kitchens, refrigerators, and the like. Thus, oil stains such as lipid peroxides are likely to adhere to the surface of the kitchen member and the like. However, by providing the hydrophilic film of the present embodiment, it is possible to easily remove the initial oil stain that has just been attached and the viscous oil using water. In addition, although the edible oil used in a kitchen is mentioned as a representative as an oil stain, it is not restricted to this, The fats and oils resulting from hand wrinkles, a fingerprint, sebum, sweat etc. can also be removed.

Hereinafter, the present embodiment will be described in more detail by way of examples and comparative examples, but the present embodiment is not limited to these examples.

The paint compositions of Examples and Comparative Examples were prepared as follows. Specifically, Monomer A, Monomer B, Monomer C, a photopolymerization initiator and a dispersion solvent shown below were mixed in the amounts shown in Tables 1, 4 and 6. At this time, using the rotation / revolution mixer Awatori Neritaro (registered trademark) (made by Shinky Co., Ltd.) as a stirrer, these materials are sufficiently mixed by stirring at a predetermined rotation speed, and the paint of each example The composition was obtained. The content of monomer A in Tables 1, 4 and 6 means the ratio of the mass of the content of monomer A to the total content of monomer A and monomer B.

(Monomer A)
Monomer A1: polyethylene glycol diacrylate in which the number of repeating units of ethylene oxide group is 9 (see the following chemical formula (6))

Monomer A2: Polyethylene glycol diacrylate in which the number of repeating units of ethylene oxide group is 14 (see the following chemical formula (7))

Monomer A3: polyethylene glycol diacrylate in which the number of repeating units of ethylene oxide group is 23 (see the following chemical formula (8))

Monomer A4: Polyethylene glycol diacrylate in which the number of repeating units of ethylene oxide group is 35 (see the following chemical formula (9))

Monomer A5: polyethylene glycol diacrylate in which the number of repeating units of ethylene oxide group is 46 (see the following chemical formula (10))

Monomer A6: EO (ethylene oxide) -modified bisphenol A diacrylate in which the number of repeating units of ethylene oxide group is 20 (see the following chemical formula (11))

(Monomer B)
Monomer B1: pentaerythritol triacrylate (see the following chemical formula (12))

(Monomer C)
Monomer C1: EO (ethylene oxide) modified bisphenol A diacrylate in which the number of repeating units of ethylene oxide group is 4 (refer to the following chemical formula (13))

Monomer C2: Methacrylate having polydimethylsiloxane (methacrylic modified silicone oil) (refer to the following chemical formula (14))

(Photopolymerization initiator)
1-hydroxycyclohexyl phenyl ketone

(Dispersion solvent)
2-butanone (methyl ethyl ketone (MEK))

Next, a 100 mm × 100 mm mirror whose outermost surface was formed of an acrylic resin was prepared as a substrate, and the surface of the substrate was washed. Then, the coating composition of each example was applied to the surface of the substrate by a bar coater, and then dried at 80 ° C. for 5 minutes to remove the dispersion solvent. Thereafter, the applied coating composition was irradiated with ultraviolet light at 600 mJ / m ² in a nitrogen atmosphere to cure the coating composition. Thereby, the test sample of each example which formed the coating film (hydrophilic film) in the surface of the base material was prepared. The ultraviolet irradiation was performed using a spot UV irradiation apparatus Spot Cure (registered trademark) SP-9 manufactured by Ushio Electric Co., Ltd. Moreover, the thickness of the coating film in the test sample of each case was about 50 micrometers.

[Evaluation]
For each test sample, pencil hardness, antifogging and water resistance were evaluated as follows. The evaluation results of the respective test samples are shown in Tables 2, 5 and 7. In addition, Table 3 shows the results of Table 2, which are arranged in the relationship of “content of monomer A” and “number of repeating units of ethylene oxide group in monomer A”. In each table, “content of monomer A” means the ratio of the mass of the content of monomer A to the total content of monomer A and monomer B.

(Pencil hardness)
The pencil hardness is the Japanese Industrial Standard JIS K 5600-5-4: 1999 (ISO / DIS 15184: 1996) (General test method for paints-Part 5: Mechanical properties of coating film-Section 4: Scratch hardness (pencil method) It measured according to). And pencil hardness was evaluated based on the following standards.
:: pencil hardness F or more ○: pencil hardness HB and B
X: Pencil hardness 2 B or less

(Anti-fogging property)
The antifogging property was measured under the atmosphere of 25 ° C. and 75% RH, at which the temperature of the test sample was 10 ° C., and the time from when the substrate began to become cloudy was visually measured. And the antifogging property was evaluated based on the following criteria.
○: The haze of the test sample was not visually observed for 60 seconds or more. ×: The haze of the test sample was visually observed less than 60 seconds.

(water resistant)
With regard to water resistance, the test sample immersed in ion-exchanged water at 25 ° C. was taken out every day and the appearance was visually observed. And water resistance was evaluated based on the following criteria.
○: No change in appearance over 7 days ×: Peeling of coating was observed within 6 days

As shown in Tables 1 to 3, when the number of repeating units of the ethylene oxide group in the monomer A is 23 or 35 and the content of the monomer A is 50% by mass to 90% by mass, the pencil hardness is , And both the antifogging and water resistance were evaluated as ◎ or ○. Furthermore, when the content of the monomer A was 80% by mass or less, all the determinations of the pencil hardness were いずれ.

On the other hand, when the number of repeating units of the ethylene oxide group in the monomer A was 14 or less, all of the determinations of the antifogging properties were x. In addition, even when the number of ethylene oxide group repeating units in the monomer A was 23 or more, when the content of the monomer A was 33% by mass or less, the determination of the antifogging property was x.

Moreover, when the number of repeating units of the ethylene oxide group in the monomer A is 46, when the content of the monomer A is 50 mass% or more, the judgment of water resistance is x. Furthermore, when the number of repeating units of ethylene oxide group in monomer A is 46, when the content of monomer A is 80% by mass, the judgment of pencil hardness is ○, and when the content of monomer A is 90% by mass, pencil hardness The judgment of has become x.

From Table 4 and Table 5, it was found that the pencil hardness, the antifogging property and the water resistance become good also when the coating film is formed using the coating composition as in Example 9 and Example 10. That is, it was found that even if a portion of polyethylene glycol diacrylate was replaced with EO-modified bisphenol A diacrylate, a coating film excellent in antifogging property, hardness and water resistance could be formed under predetermined conditions. . Specifically, it was found that when the number of repeating units of ethylene oxide group and the content of monomer A fall within the predetermined range, a coating film excellent in antifogging property, hardness and water resistance can be formed.

From Table 6 and Table 7, when a coating film was formed using the coating composition like Example 12, it turned out that pencil hardness becomes better. That is, in addition to the monomer A and the monomer B, when a methacryl modified silicone oil was added as the monomer C, it turned out that pencil hardness becomes better.

As mentioned above, when the number of the repeating units of the ethylene oxide group in the monomer A is a predetermined | prescribed range, and the content rate of the monomer A and the monomer B is a predetermined | prescribed range, the coating which was excellent in anti-fogging property, hardness, and water resistance. It has been found that a film can be formed.

The entire contents of Japanese Patent Application No. 2017-231598 (filing date: December 1, 2017) are incorporated herein by reference.

As mentioned above, although this embodiment was described, this embodiment is not limited to these, A various deformation | transformation is possible within the range of the summary of this embodiment.

ADVANTAGE OF THE INVENTION According to this invention, the coating composition and hydrophilic member which can form the coating film excellent in anti-fogging property can be provided.

Claims

A first monomer having an ethylene oxide group repeating unit and a bifunctional (meth) acryloyl group in one molecule,
A second monomer having a trifunctional or higher functional (meth) acryloyl group and a monofunctional or higher function hydroxyl group in one molecule;
Including
The number of repeating units of the ethylene oxide group in the first monomer is 18 to 40,
When the total content of the first monomer and the second monomer is 100% by mass, the content of the first monomer is 40% by mass to 95% by mass, and the content of the second monomer is 5 % By mass to 60% by mass,
The content of the first monomer is 40% by mass to 85% by mass with respect to the total solid content,
A paint composition, wherein the content of the second monomer is 10% by mass to 55% by mass with respect to the total solid content.
2. The coating composition according to claim 1, wherein the first monomer is a di (meth) acrylate monomer having the (meth) acryloyl group at both ends of the main chain including the repeating unit of the ethylene oxide group.
The coating composition according to claim 1, further comprising (meth) acrylate having a polysiloxane.
A substrate,
A hydrophilic film provided on the substrate and formed of the paint composition according to any one of claims 1 to 3;
, A hydrophilic member.