JP2023020482A - hydrophilic composition - Google Patents

Abstract

To provide a composition capable of forming a coating film which can suppress generation of sagging and can exhibit good hydrophilicity and durability when applied on the whole surface (in particular, a vertical surface) of a water section member having a three-dimensional shape.SOLUTION: There is provided a hydrophilic composition which comprises a hydrophilic component containing a compound A having a sulfonic acid group or a sulfonic acid salt group in one molecule and at least one ethylenically unsaturated group in one molecule, a film-forming component containing a compound B having 3 or more ethylenically unsaturated groups in one molecule and a hydroxyl group, organic particles and an organic solvent, wherein 20 wt.% of the film-forming component is contained in the hydrophilic composition, the total hydroxyl group value is 15 mgKOH/g or more and less than 175 mgKOH/g, the weight average molecular weight is 1000 g/mol or more, the functional group equivalent of the ethylenically unsaturated group is less than 242 g/eq and 1 wt.% or more and less than 50 wt.% of the organic particles is contained in the hydrophilic composition with respect to the film-forming component.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a hydrophilic composition, and more particularly to a hydrophilic composition capable of forming a good film on the surface of a member having a three-dimensional shape.

As one means of imparting desired functions to various members surrounding the living environment, it is known to provide a coating film having a desired function on the surface of these members. are being developed at the same time.

For example, Japanese Patent Application Laid-Open No. 2014-233946 (Patent Document 1) describes sulfopropyl methacrylate potassium salt as a hydrophilic component, dipentaerythritol hexaacrylate, which is a polyfunctional acrylic monomer, as a film-forming component, and a volatile compound. A paint is described which further contains acrylic resin beads having a volume average particle size of 35 μm in addition to hydroxyethyl methacrylate, Irgacure 500 as a photoinitiator, water and methoxyethanol as an organic solvent. Also, this paint is applied to the surface of a base material (acrylic plate), dried by heating, and then irradiated with ultraviolet rays to cure. It is described that it has good hydrophilicity and anti-slip properties, and that it has durability (Examples 1 to 5, Table 1).

On the other hand, Patent Document 1 exemplifies plumbing members such as bathroom floor materials and washbowl materials as base materials (paragraph 0049), but the manifestation of functions such as hydrophilicity has been specifically confirmed. is only the top surface of the surface of the acrylic plate, that is, the surface of the plumbing member having a three-dimensional shape, as described above. Therefore, it has not been confirmed or taken into consideration whether a similar function can be obtained for an upright surface.

JP 2014-233946 A

The inventors of the present invention have found a problem that when a paint having the composition disclosed in Patent Document 1 is applied to the entire surface of a three-dimensional plumbing member, the paint drips particularly on the upright surface. In addition, the coating film obtained by applying the coating material having the composition disclosed in Patent Document 1 to the surface of the plumbing member is rubbed with a strong force after curing, or the coating film is rubbed with an abrasive or an alkaline detergent. When a strong load such as cleaning is applied, the surface of the coating film on which sulfonic acid groups are present may be scraped, and as a result, the hydrophilicity once obtained may not be maintained. Therefore, it is desirable that the resulting coating film has high durability.

The present inventors have found that when the paint disclosed in Patent Document 1 is applied to the entire surface of the plumbing member, the viscosity of the paint is We tried measures to increase Specifically, as a measure for increasing the viscosity of the paint, (i) replacement of the compound used as the film-forming component with a compound having a higher molecular weight was examined. With this measure, it was possible to suppress the sagging of the paint after it was applied and before it was cured. On the other hand, the presence of sulfonic acid groups on the surface of the coating film is affected by the polarity of the compound used as the film-forming component, and hydrophilicity cannot be obtained in the coating film. In some cases, film strength was not obtained.

In addition, as a measure to increase the viscosity of the paint, (ii) increasing the amount of the particle component contained in the paint was examined. Even with this measure, it was possible to suppress the sagging of the paint after it was applied until it was cured. On the other hand, the presence of a large number of particle components in the coating film affects the state of existence of sulfonic acid groups on the surface of the coating film, lowering the hydrophilicity, inducing cohesive failure, and making the coating film brittle. , or a difference in thermal expansion may occur, and the thermal durability of the coating film may decrease.

On the other hand, in order to suppress sagging of the paint applied to the surface of the plumbing member, it was studied to separately apply the paint to the top surface and the vertical surface of the plumbing member. In this method, a boundary surface (seam) was generated between the coating film on the top surface and the coating film on the vertical surface, but if the seam was recoated, it may peel off, and on the other hand, the seam was left as it was (unpainted). ), dirt adhered, and there was a problem in terms of quality.

In this way, in a paint that can form a coating film having hydrophilicity and durability (strength, heat resistance, etc.), at the same time, the occurrence of sagging of the paint is suppressed, especially when it is applied to the vertical surface of a plumbing member. This has been difficult in the past.

The present inventors have recently developed a coating film that can suppress the occurrence of sagging when coated on the entire surface, particularly the vertical surface, of a plumbing member having a three-dimensional shape, and can exhibit hydrophilicity and durability. We have found a coating composition that can be formed. In particular, by specifying the chemical properties of the film-forming component contained in the coating composition, when such a coating composition is applied to the entire surface of a water-related member having a three-dimensional shape, especially the vertical surface, sagging occurs. was suppressed, and a coating film capable of exhibiting good hydrophilicity and durability was obtained. The present invention is based on such findings.

Therefore, the present invention provides a coating that can suppress the occurrence of sagging when applied to the entire surface (particularly, the vertical surface) of a plumbing member having a three-dimensional shape, and can exhibit good hydrophilicity and durability. The object is to provide a composition capable of forming a film.

And the hydrophilic composition according to the present invention is
a hydrophilic component comprising a compound A having a sulfonic acid group or a sulfonic acid group and at least one ethylenically unsaturated group in one molecule;
a film-forming component containing a compound B having three or more ethylenically unsaturated groups and a hydroxyl group in one molecule;
organic particles;
A hydrophilic composition comprising an organic solvent,
The film-forming component is
20% by weight or more in the hydrophilic composition,
The total hydroxyl value is greater than 15 [mgKOH/g] and less than 175 [mgKOH/g],
The weight average molecular weight is 1000 [g/mol] or more, and the functional group equivalent weight of the ethylenically unsaturated group is less than 242 [g/eq],
The organic particles are characterized by being contained in the hydrophilic composition in an amount of 1% by weight or more and less than 50% by weight with respect to the film-forming component.

According to the present invention, when applied to the entire surface (particularly, the vertical surface) of a plumbing member having a three-dimensional shape, it is possible to suppress the occurrence of sagging, and the coating can exhibit good hydrophilicity and durability. A hydrophilic composition is provided that is capable of forming a film. More specifically, the composition according to the present invention contains a specific hydrophilic component, a specific amount of a film-forming component having a specific chemical specificity, a specific amount of organic particles, and an organic solvent that interact in intimately incompatible ways. Therefore, it is considered that the following effects are achieved.
- It is possible to obtain a cured film that can suppress the occurrence of sagging during the period from the application of the composition to the member until the composition is cured, and that can maintain hydrophilicity and durability. More specifically,
- after application of the composition to the surface of the component, no sagging occurs before drying the (wet) coating,
- (Wet) The surface does not sag (flow) during drying of the applied material, and at the same time, the sulfonic acid group contained in the hydrophilic component is applied as the organic solvent evaporates. It is believed that segregation to the surface of the material progresses, and
- Even after volatilization of the solvent and before curing, the surface of the uncured film does not flow and sag, and
・ Even if the cured film obtained by curing the uncured film is rubbed with strong force or cleaned with an abrasive or alkaline detergent, the surface of the cured film will not It can maintain high durability (strength) without being scraped. It is believed that this durability maintains the segregation state of the sulfonic acid groups once obtained on the surface of the member, and as a result, the hydrophilicity is maintained.
In the above description, the meanings of the terms "cured film", "(wet) coating", "uncured film", and "segregation of sulfonic acid groups" are as described later.

1 is a perspective view showing an installation example of a bathroom counter in a bathroom to which the hydrophilic composition according to the present invention can be applied; FIG. 1 is a perspective view showing a bathroom counter to which a hydrophilic composition according to the invention can be applied; FIG.

Hydrophilic Composition The hydrophilic composition according to the present invention is
a hydrophilic component comprising a compound A having a sulfonic acid group or a sulfonic acid group and at least one ethylenically unsaturated group in one molecule;
a film-forming component containing a compound B having three or more ethylenically unsaturated groups and a hydroxyl group in one molecule;
organic particles;
and an organic solvent.

Before describing each component contained in the hydrophilic composition according to the present invention, members to which the hydrophilic composition according to the present invention can be applied will be described below.

Applications The hydrophilic composition according to the present invention can be applied to the surfaces of various members. Preferably, it can be applied to the surface of a member having a three-dimensional shape. More preferably, it can be applied to the surface of a resin member having a three-dimensional shape.

The hydrophilic composition according to the present invention can preferably be applied to the surface of a plumbing member. In the present invention, plumbing members refer to members used in toilets, bathrooms, kitchens, bathroom vanities, and the like. For example, bathroom wall materials, bathroom floor materials, bathroom counters, bathtubs, bathtub rims (rims), bathroom window materials, bathroom door materials, shower booth wall materials, bathroom mirrors, bathroom vanities, washbowls, kitchen counters, kitchen doors, Storage racks, storage plates, toilet bowls, toilet seats, warm-water washing toilet seats and their washing nozzles, drains, faucet fittings, range hood materials, etc., but are not limited to these. According to a preferred aspect of the present invention, the plumbing member to which the hydrophilic composition according to the present invention is applied is a plumbing member having a three-dimensional shape.

As an example of a plumbing member having a three-dimensional shape, a bathroom counter and a bathtub rim will be described with reference to FIG. FIG. 1 is a perspective view schematically showing an example of a bathroom. Bathroom 100 has a plurality of wall surfaces (side walls) including first to third wall surfaces 110 to 130, a floor surface, and a ceiling surface. Each wall surface, floor surface, and ceiling surface form a bathroom space BS. Bathtub 90 is provided in bathroom space BS. The bathtub 90 has a rim (edge), and the user can enter and exit the bathtub by grasping the rim. Moreover, the bathroom 100 is provided with a faucet counter 11 and a washing counter 12 as the counter 10 . The faucet counter 11 discharges water. The washing counter 12 is a relatively large plate-like member on which articles such as shampoo bottles and wash basins can be placed.

FIG. 2 is a perspective view showing one aspect of a plumbing counter 200 such as the bathroom counter 10 shown in FIG. The counter 200 has a top surface (water receiving surface) 201 , a vertical surface 202 , and an end portion 203 connecting the top surface 201 and the vertical surface 202 . The top surface 201 is a surface formed in the horizontal direction, and the upright surface 202 is a surface formed in the vertical direction. The upright surface 202 and the end portion 203 are provided in the drainage direction. The end portion 203 is a surface through which water that has moved from the top surface 201 passes. After passing through the end portion 203, the water moves downward and is drained. The end portion 203 is provided downward from the top surface 201 and includes a curved surface portion having an arcuate cross section with a predetermined radius of curvature.

The hydrophilic composition according to the present invention is preferably applied (for example, applied) to the entire surface of a plumbing member having a three-dimensional shape. In particular, on surfaces having an inclination (relative to the horizontal surface) such as the vertical surface 202 and the edge 203 of the counter shown in FIG. can be formed. This cured film can exhibit good hydrophilicity and durability by being uniform.

Each component contained in the hydrophilic composition according to the present invention is described below. Hereinafter, the "hydrophilic composition according to the present invention" may be referred to as "the composition according to the present invention" or simply "the composition". A film obtained by curing the "composition" may also be referred to as a "cured film of the composition" or simply a "cured film".

Hydrophilic Component In the present invention, the hydrophilic component includes compound A having a sulfonic acid group or sulfonic acid group and at least one ethylenically unsaturated group in one molecule.
Compound A
Compound A contains a sulfonic acid group or sulfonate group. By including a sulfonic acid group or a sulfonate group, the cured film of the composition according to the present invention can exhibit hydrophilicity. By having hydrophilicity, for example, when the composition according to the present invention is applied to the surface of a plumbing member, the drainage and drying properties are improved, and it is possible to suppress the adhesion of stains such as limescale due to residual water. In addition, it is advantageous in that the adhesion of oil can be suppressed. The cured film of the composition according to the present invention preferably contains more sulfonic acid groups or sulfonate groups on the surface than on the inside. That is, the cured film of the composition according to the present invention preferably has sulfonic acid groups segregated on its surface.

As will be described later, a cured film of the composition according to the invention is obtained as follows. First, the composition is applied onto a substrate, and the (wet) application of the composition applied onto the substrate is dried to obtain a (dry) application. After that, the (dry) coated product of the composition is cured to obtain a cured film of the composition. In the present specification, the dried (wet) coating, ie the (dry) coating, is also referred to as an "uncured film" because it is subsequently subjected to curing. As described above, the state in which the sulfonic acid groups are segregated on the surface of the cured film of the composition according to the present invention can be achieved by the following steps, but is not limited thereto. By drying the (wet) application of the composition, i.e. volatilize the solvent and optionally the volatile composition C (the details of which are described below) that were included in the (wet) application together with compound A. As a result, compound A, which was uniformly dispersed in the composition, is transferred to the surface of the uncured film along with the progress of drying (volatilization) by utilizing the polarity difference and compatibility with volatile compound C. Segregate. Then, the uncured film is cured while drying of the (wet) coating is almost completed and the segregation of compound A on the surface of the uncured film is maintained.

In the present invention, compound A may have a sulfonic acid group or sulfonic acid group and at least one ethylenically unsaturated group. In the present invention, the ethylenically unsaturated group of compound A is preferably vinyl group, acryloyl group or methacryloyl group, more preferably acryloyl group or methacryloyl group. Compound A includes, for example, sodium or potassium salts of 2-((meth)acryloyloxy)ethanesulfonic acid, 3-((meth)acryloyloxy)propane-1-sulfonic acid, and acrylamido-tert-butylsulfonic acid. Preferably, 2-((meth)acryloyloxy)ethanesulfonic acid, 3-((meth)acryloyloxy)propane-1-sulfonic acid potassium, which is a linear alkylsulfonic acid having a (meth)acryloyloxy group and its salts (3-Sulfopropylpotassium (meth)acrylate). Also, methacrylsulfonic acid, p-styrenesulfonic acid sodium or potassium salt, alkylsulfosuccinic acid alkenyl ether salt, polyoxyethylene (meth)acrylate sulfate ester salt, alkylsulfosuccinic acid alkenyl ester salt, glycerol-1-allyl-3- Alkylphenyl-2-polyoxyethylene sulfates and the like can also be used. These compounds have sufficient reactivity with the film-forming component containing the compound B having three or more ethylenically unsaturated groups and a hydroxyl group in one molecule described later, and the cured film of the composition according to the present invention high durability (strength, heat durability).

In the present invention, the "hydrophilic component" means a substance that imparts hydrophilicity to the cured film of the composition. Specifically, it means a compound having hydrophilicity.

Film-forming component In the present invention, the film-forming component contains at least one compound B having 3 or more ethylenically unsaturated groups and hydroxyl groups in one molecule, and 20% by weight of the composition according to the present invention. includes more than
The total hydroxyl value is greater than 15 [mgKOH/g] and less than 175 [mgKOH/g],
Its weight average molecular weight is 1000 [g/mol] or more, and its functional group equivalent of the ethylenically unsaturated group is less than 242 [g/eq].

In the present invention, "film-forming component" means a substance that physically constitutes a cured film. Specifically, it means a compound having two or more ethylenically unsaturated groups in one molecule.

The composition according to the present invention is characterized in that the film-forming component contained therein has three chemical properties of total hydroxyl value, weight-average molecular weight and functional group equivalent weight of ethylenically unsaturated groups within specific ranges, and and these four characteristics interact in a non-close manner, so that when applied to the entire surface of a member having a three-dimensional shape, there is no sagging, especially on the vertical surface of the member. It is believed that this greatly contributes to the effect of obtaining a cured film that is suppressed and maintains hydrophilicity and durability. The relationship between each feature of the film-forming component and the effect that it is believed to contribute mainly will be described below.

In the present invention, the content of the film-forming component in the composition is 20% by weight or more, and the weight-average molecular weight of the film-forming component is 1000 [g/mol] or more. This is considered to contribute to The weight average molecular weight of the film-forming component is preferably 1309 [g/mol] or more, more preferably 1493 [g/mol] or more and 8875 [g/mol] or less.
The weight average molecular weight is obtained as follows.
The weight average molecular weight is calculated from the following formula for the compound defined as the film-forming component.

In the present invention, the total hydroxyl value of the film-forming components of more than 15 [mgKOH/g] and less than 175 [mgKOH/g] contributes to at least increasing the hydrophilicity of the cured film of the composition. it is conceivable that. The total hydroxyl value of the film-forming components is preferably 15 [mgKOH/g] or more and 123 [mgKOH/g] or less, more preferably 23 [mgKOH/g] or more and less than 81 [mgKOH/g].
The hydroxyl value is determined as follows.
For compounds defined as film-forming components, the average hydroxyl value is calculated from the following formula.

In the present invention, it is believed that the lower the functional group equivalent of the ethylenically unsaturated group of the film-forming component, the more it contributes to at least the durability of the cured film of the composition. According to one aspect of the present invention, the functional group equivalent weight of the ethylenically unsaturated group of the film-forming component is more than 103 [g/eq] and less than 242 [g/eq]. The functional group equivalent weight of the ethylenically unsaturated group of the film-forming component is preferably 194 [g/eq] or less, more preferably 105 [g/eq] or more and 159 [g/eq] or less. It is considered that this makes it possible to increase the durability of the cured film.
The functional group equivalent weight of the ethylenically unsaturated group is obtained as follows.
For a compound defined as a film-forming component, the functional group equivalent weight of the ethylenically unsaturated group is calculated from the following formula.

In the present invention, the ethylenically unsaturated group of the film-forming component is preferably vinyl group, acryloyl group or methacryloyl group, more preferably acryloyl group or methacryloyl group.

In the present invention, the film-forming component may consist of the compound B only, or may contain a component other than the compound B. When the film-forming component consists only of compound B, compound B preferably has the above characteristics.

In the present invention, a (meth)acrylate monomer (oligomer), a urethane-modified urethane (meth)acrylate monomer (oligomer) thereof, and an epoxy-modified epoxy (meth)acrylate monomer (oligomer) are used as film-forming components. can be used.

Examples of (meth)acrylate monomers (oligomers) include 2-hydroxy-3-acryloyloxypropyl methacrylate, propoxylated ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A diacrylate, 9,9-bis[4-(2 -acryloyloxyethoxy)phenyl]fluorene, propoxylated bisphenol A diacrylate, tricyclodecanedimethanol diacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate , dipropylene glycol diacrylate, tripropylene glycol diacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone-modified tris(2-acryloxyethyl) isocyanurate, pentaerythritol triacrylate, trimethylolpropane triacrylate, ditrimethylolpropane trimethacrylate, ethoxylated glycerin triacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 2, 2bis[4-(methacryloxyethoxy)phenyl]propane, tricyclodecanedimethanol dimethacrylate, 1,10-decanediol dimethacrylate, 1,6-hexanediol methacrylate, 1,9-nonanediol methacrylate, neopentyl glycol Methacrylate, glycerin dimethacrylate, trimethylolpropane trimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, glycerin triacrylate ethoxylate, dipentaerythritol polyacrylate, ethoxylated polypropylene glycol dimethacrylate, polypropylene dimethacrylate, and the like.

Urethane (meth)acrylate oligomers (polymers) having two or more ethylenically unsaturated groups include, for example, phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer, phenyl glycidyl ether acrylate toluene diisocyanate urethane prepolymer, pentaerythritol tri Acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, oligourethane acrylate, carboxylic acid-containing urethane acrylate oligomer etc.

Examples of epoxy (meth)acrylate oligomers (polymers) having two or more ethylenically unsaturated groups include cresol novolak-type epoxy acrylates and carboxylic acid anhydride-modified epoxy acrylates.

Among these, those having no hydrophilic functional group such as a hydroxyl group, a carboxyl group, or an ethylene oxide chain are particularly preferred because they have low compatibility with the compound A and are effective in segregating the compound A on the surface. Such film-forming components include propoxylated ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A diacrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, propoxylated bisphenol A diacrylate, Tricyclodecane dimethanol diacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, ethoxylated isocyanurate acid triacrylate, ε-caprolactone-modified tris(2-acryloxyethyl)isocyanurate, trimethylolpropane triacrylate, ditrimethylolpropane trimethacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 2,2 bis[4-(methacryloxyethoxy)phenyl]propane, tricyclodecanedimethanol dimethacrylate, 1,10-decanediol dimethacrylate, 1, 6-hexanediol methacrylate, 1,9-nonanediol methacrylate, neopentyl glycol methacrylate, glycerin dimethacrylate, trimethylolpropane trimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate , glycerin triacrylate ethoxylate, ethoxylated polypropylene glycol dimethacrylate, polypropylene dimethacrylate, phenyl glycidyl ether acrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, penta Erythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer.

In the present invention, compounds B having three or more ethylenically unsaturated groups and hydroxyl groups in one molecule include pentaerythritol tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, propoxylated pentaerythritol tri( meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol tri(meth)acrylate Acrylate, ethoxylated dipentaerythritol tetra(meth)acrylate, ethoxylated dipentaerythritol penta(meth)acrylate, polyglycerin monoethylene oxide poly(meth)acrylate, (meth)acrylic acid ester copolymer, etc. can be used. can.

上記式中、ｍ１は１～１０００であることが好ましく、１～２００であることがより好ましい。ｍ２は５～１０００であることが好ましく、１０～２００であることがより好ましい。
化合物Ｂ１－１の重量平均分子量は１０００～２０００００、エチレン性不飽和基の官能基当量は２００～６００（ｇ／ｅｑ）、水酸基価は５０～２９０（ｍｇＫＯＨ／ｇ）であることが好ましい。 Compound B1
In the present invention, the film-forming component preferably contains, as compound B, compound B1, which is an oligomer or polymer having an acrylic skeleton and having hydroxyl groups and three or more (meth)acrylate groups in side chains.
Compound B1-1 represented by the following formula can be used as such compound B1.

In the above formula, m1 is preferably 1-1000, more preferably 1-200. m2 is preferably 5-1000, more preferably 10-200.
Compound B1-1 preferably has a weight average molecular weight of 1,000 to 200,000, an ethylenically unsaturated functional group equivalent of 200 to 600 (g/eq), and a hydroxyl value of 50 to 290 (mgKOH/g).

この化合物は、重量平均分子量が１０５００、エチレン性不飽和基の官能基当量が３１４（ｇ／ｅｑ）、水酸基価が１７９（ｍｇＫＯＨ／ｇ）である。 According to a preferred embodiment of the present invention, compound B1-1 is, for example, the following compound.

This compound has a weight average molecular weight of 10,500, a functional group equivalent of ethylenically unsaturated groups of 314 (g/eq), and a hydroxyl value of 179 (mgKOH/g).

上記式中、ｎは５～１０００であることが好ましく、２０～２００であることがより好ましい。
化合物Ｂ１－２の重量平均分子量は１０００～２０００００、エチレン性不飽和基の官能基当量は２００～２５０（ｇ／ｅｑ）、水酸基価は２３０～２９０（ｍｇＫＯＨ／ｇ）であることが好ましい。 Further, as compound B1, compound B1-2 represented by the following formula can be used.

In the above formula, n is preferably 5-1000, more preferably 20-200.
Compound B1-2 preferably has a weight average molecular weight of 1,000 to 200,000, an ethylenically unsaturated functional group equivalent of 200 to 250 (g/eq), and a hydroxyl value of 230 to 290 (mgKOH/g).

この化合物は、重量平均分子量が１３０００、エチレン性不飽和基の官能基当量が２１８（ｇ／ｅｑ）、水酸基価が２５７（ｍｇＫＯＨ／ｇ）である。 According to a preferred embodiment of the invention, compounds B1-2 are for example:

This compound has a weight average molecular weight of 13,000, a functional group equivalent of ethylenically unsaturated groups of 218 (g/eq), and a hydroxyl value of 257 (mgKOH/g).

Compound B2
In the present invention, the film-forming component preferably further contains compound B2, which is a polyfunctional (meth)acrylic monomer or oligomer having three or more functional groups in one molecule and no hydroxyl group. Containing a polyfunctional (meth)acrylic monomer or oligomer having three or more functional groups in one molecule is considered to contribute at least to the suppression of sagging of the composition, and the durability of the cured film of the composition. As a result, the segregation state of the sulfonic acid groups on the surface of the member is maintained, which is thought to contribute to the maintenance of hydrophilicity.

In the present invention, as the compound B2, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, propoxylated pentaerythritol tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, trimethylolpropane tri ( meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, ε-caprolactone-modified tris-(2-acryloxyethyl)isocyanurate, propoxylated dipentaerythritol hexa(meth)acrylate, propoxylated ditrimethylolpropane tetra(meth)acrylate and the like.

In the present invention, the film-forming component may contain both compounds B1 and B2. In this case, the weight ratio of compounds B1 and B2 is preferably B1:B2=1:0.5 or more and 29 or less, more preferably 1:1 or more and 12 or less. In the present invention, the weight ratio of B1 to compound B contained in the film-forming component is preferably 25% by weight or more and 100% by weight or less, more preferably 40% by weight or more and 100% by weight or less.

In the present invention, the composition contains 20% by weight of the film-forming component. This suppresses the composition from dripping. The ratio of the film-forming component contained in the composition may be determined in consideration of the coating method, film thickness, and the like. Specifically, it is preferably contained in an amount of 25% by weight or more, more preferably 30% by weight or more.

Organic Particles In the present invention, the organic particles are contained in the composition according to the present invention in an amount of 1% by weight or more and less than 50% by weight based on the film-forming components. The content is preferably 5% by weight or more and less than 50% by weight, and more preferably 5% by weight or more and 40% by weight or less. By containing the organic particles within this range, the composition according to the present invention is more inhibited from sagging. Examples of organic particles include particles containing at least one selected from acrylic, urethane, and polycarbonate. In the present invention, the organic particles are preferably acrylic particles. Since the acrylic particles have a high affinity with the acrylic main skeleton constituting the cured film of the composition according to the present invention, the occurrence of sagging can be further suppressed. The average particle size of the organic particles is preferably 1 μm or more and 50 μm or less, more preferably 5 μm or more and 35 μm or less. When the size of the organic particles is within the above range, the composition of the present invention is further prevented from sagging.

Organic Solvent The composition according to the invention comprises an organic solvent. By containing an organic solvent, as described later, the (wet) coating of the composition according to the present invention is dried, and the organic solvent is volatilized, thereby reducing the sulfonic acid group of the hydrophilic component to the polarity difference and It is considered that the composition can be segregated on the surface of the uncured film of the composition along with the progress of drying (volatilization) by utilizing the compatibility with the volatile compound C and the like. By curing the uncured film while the drying is almost completed and the segregation of sulfonic acid groups to the surface of the uncured film is maintained to the maximum, the segregation can be achieved more reliably. it is conceivable that.

Examples of such an organic solvent include alcohols such as methanol, ethanol, IPA (isopropanol), n-butanol, methoxyethanol, methoxy Cellosolves such as propanol, acetone, ketones such as MEK (methyl ethyl ketone), ethyl acetate, butyl acetate, THF (tetrahydrofuran), toluene, PEGMEA (propylene glycol monomethyl ether acetate), DMF (N,N'-dimethylformamide) and water, but are not limited to these. A plurality of types of solvents may be mixed and used as necessary. In the present invention, the composition preferably contains an amount of organic solvent that does not cause dripping when the composition is applied to a substrate. In the present invention, the composition preferably contains 10% by weight or more of the organic solvent, more preferably 20% by weight or more. The composition preferably contains 80% by weight or less of the organic solvent, more preferably 70% by weight or less.

Other ingredients
Volatile compound C
The composition according to the invention preferably further comprises a volatile compound C, which has a lower molecular weight than compound A and has one ethylenically unsaturated group and a hydrophilic group in one molecule. Here, a volatile compound means a compound having a boiling point of 280° C. or lower, more preferably 260° C. or lower. Moreover, the hydrophilic group which the volatile compound C has is preferably a hydroxyl group or a carboxyl group. Specific examples of volatile compounds C include hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate and structural isomers thereof, hydroxybutyl (meth) acrylate and structural isomers thereof, tetrahydro Furfuryl (meth)acrylate, (meth)acryloylmorpholine, N-vinylformamide, (meth)acrylic acid and the like. Among them, as the volatile compound C, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, and (meth)acrylic acid are preferable from the viewpoint of compatibility with compound A.

A cured film of the composition according to the present invention is obtained by applying the composition onto a substrate, drying the (wet) coating on the substrate, and curing the uncured film, as described below. At this time, the compound A containing a sulfonic acid group and the volatile compound C are sufficiently compatible with each other, so that when the (wet) applied product is (heated) dried, the compound C is formed on the surface of the uncured film together with the compound A. It is thought that the compound A can be uniformly distributed on the surface of the uncured film by segregation. In addition, since the volatile compound C remaining in the uncured film can be easily polymerized with the compound B when curing the uncured film, it is possible to further increase the strength of the cured film.

The molecular weight of the volatile compound C is not particularly limited as long as it is smaller than the molecular weight of the compound A, but it is preferably 500 or less. When the molecular weight of the volatile compound C is 500 or less, the volatile compound C can be efficiently volatilized when the (wet) applied composition is dried. In addition, when the volatile compound C is volatilized together with the organic solvent, phase separation occurs between the compound A containing a sulfonic acid group and the compound B that are compatibilized by containing the volatile compound C. It is believed that this phase separation promotes the segregation of compound A containing sulfonic acid groups onto the surface of the uncured film.
More preferably, the molecular weight of the volatile compound C is 100-200. Thereby, the compound C can be volatilized without reducing the strength of the cured film when the uncured film of the composition is cured (polymerized).

Polymerization Initiator In the present invention, as described later, when an uncured film of the composition is cured (polymerized) by heat, the composition may contain a known radical polymerization initiator, curing catalyst, polymerization accelerator, and the like. good. In addition, when the uncured film of the composition is cured (polymerized) by radiation, for example, active energy rays such as ultraviolet rays and visible light, the composition may contain a known photopolymerization initiator. Examples of the photopolymerization initiator include Omnirad 500 manufactured by IGM.

Method for producing a cured film of the composition according to the present invention A cured film of the composition according to the present invention can be produced, for example, as follows.

Preparation of Substrate First, a substrate to be coated with the composition is prepared. The substrate to which the hydrophilic composition according to the present invention is applied is not particularly limited. Materials for the substrate include metal, glass, resin, paper, and wood materials. Resin is preferred. Thermosetting resins and thermoplastic resins are included. As the thermosetting resin, it is possible to use one or more selected from urea resin, melamine resin, phenol resin, unsaturated polyester resin, epoxy resin, and silicone resin. Thermoplastic resins include polypropylene resin (PP), polyethylene resin (PE), polyacetal resin (POM), polybutylene terephthalate resin (PBT), polyvinyl chloride resin (PVC), polystyrene resin (PS), acrylonitrile-butadiene-styrene. Copolymer resin (ABS), polyphenylene sulfide resin (PPS), polyethylene terephthalate resin (PET), polymethyl methacrylate resin (PMMA), polyamide resin (PA), polyether ether ketone resin (PEEK), polytrimethylene terephthalate resin (PTT), polycarbonate resin (PC), and polytetrafluoroethylene (PTFE) (tetrafluoroethylene resin) can be used. In the present invention, it is preferable to use a thermoplastic resin as the resin. More preferably, the resin is one or more selected from PP, PE, POM, PBT, PVC, ABS, PPS, PET, PMMA, PA, and PC. Among these, one or more selected from PP, POM, PBT, ABS and PMMA are more preferred. Since the cured film of the composition according to the present invention has an acrylic main skeleton, the substrate of the acrylic resin material has good affinity (for example, adhesion) with the cured film of the composition. Moreover, the shape of the substrate to which the hydrophilic composition according to the present invention is applied is not particularly limited, and examples thereof include a planar shape and a three-dimensional shape. The hydrophilic composition according to the present invention is less prone to sagging when applied to a substrate, and is therefore preferably applied to a substrate having a three-dimensional shape.

In the present invention, the substrate is preferably a plumbing member having a three-dimensional shape. Plumbing parts are often used in an environment where they are regularly exposed to water. It is possible to suppress the adhesion of stains such as water scale and oil due to residual water.

Application Step The composition is then applied onto a substrate to form a (wet) application of the composition.
In the present invention, known methods such as brush coating, spray coating, dip coating, spin coating, and curtain coating can be used as methods for applying the composition to the substrate.

Drying Step Next, the (wet) coating formed on the substrate is dried to obtain an uncured film. In this case, the (wet) applied material may be dried, and if necessary, it may be dried by heating. By drying (heating), the organic solvent and volatile compound C contained in the (wet) applied material are volatilized. In this process, in parallel with volatilization of the organic solvent and volatile compound C from the (wet) applied material (in other words, following the movement of the organic solvent and volatile compound C to the uncured film surface) ), before (heating) drying, the hydrophilic component that was uniformly dispersed in the (wet) coating material is applied to the surface of the uncured film by using the polarity difference and compatibility with the volatile compound C. It is thought that it will be segregated.

As a method of heat drying, a known method of drying with infrared rays, hot air, or the like can be used. The heating temperature is usually room temperature to 200°C, preferably 35°C to 150°C, more preferably 40°C to 100°C. The drying time may be appropriately determined within a range in which the organic solvent and the volatile compound C can be sufficiently volatilized, and may be determined according to the material and size of the member to which the composition is applied. For example, it can be within 30 minutes, preferably within 20 minutes, and more preferably within 15 minutes.

Curing Step Next, the uncured film is cured. That is, compounds A, B and C are copolymerized. Curing of the uncured film is carried out while the organic solvent and volatile compound C are sufficiently volatilized by the (heating) drying process and the segregation of the hydrophilic components on the surface of the uncured film is maintained. It is preferred that It is believed that this makes it possible to determine the state in which the sulfonic acid groups are segregated on the surface of the cured film. As a result, it is considered that the cured film of the composition according to the present invention can exhibit sufficient hydrophilicity.

As a method for curing the uncured film, a known method for polymerizing a compound containing an ethylenically unsaturated group, such as heat curing, active energy ray curing, or a combination thereof, can be used.

When polymerizing and curing by heat curing, a known polymerization initiator can be used. As for the heating method, a known method of heating with infrared rays, hot air, or the like can be used in the same manner as in the step of drying the (wet) coated material described above. In the case of heat curing, the drying step and the curing step of the (wet) coated material can be carried out simultaneously in one step.

When polymerization and curing are performed using active energy rays, the radiation includes visible light of 400 to 800 nm, ultraviolet rays of 400 nm or less, and electron beams. preferable. A known photopolymerization initiator is used when curing is performed with ultraviolet rays. The photopolymerization initiator is added in an amount of 0.01 to 20% by mass, preferably 1 to 10% by mass, based on the mass of film-forming components contained in the composition. Ultraviolet light sources include low-pressure mercury lamps, high-pressure mercury lamps, extra-high pressure mercury lamps, xenon lamps, gallium lamps, metal halide lamps, ultraviolet lasers, and ultraviolet rays such as sunlight. The irradiation atmosphere may be the atmosphere or an inert gas such as nitrogen or argon.

The thickness of the cured film of the composition according to the present invention produced as described above may be appropriately determined according to its use and within the range in which the effects of the present invention can be exhibited. For example, it is preferably in the range of 0.1 μm to 300 μm, more preferably in the range of 1 to 100 μm, even more preferably in the range of 1 to 20 μm.

Water Contact Angle In the present invention, the cured film of the composition according to the present invention preferably has hydrophilicity. This hydrophilicity can be expressed as an index of the static contact angle with water. The static contact angle of the cured film of the composition according to the present invention to water is measured, for example, using a portable contact angle meter PCA-11 (manufactured by Kyowa Interface Science Co., Ltd.), at room temperature, dropping a 1 μL water droplet on the surface of the cured film. . The surface of the cured film is measured at several points, and the average value of the values analyzed by the θ/2 method can be taken as the value of the water contact angle. The water contact angle of the cured film of the composition according to the present invention is preferably 45° or less, more preferably 35° or less. When water adheres to the surface of the cured film having such a water contact angle, a rolling-up effect is obtained, and the surface becomes resistant to stains.

The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

Raw Materials for Composition As raw materials for the composition , the following materials were prepared.

<Hydrophilic component>
・Hydrophilic component 1
3-Sulfopropylpotassium methacrylate (molecular weight: 246) represented by the following formula

・Hydrophilic component 2
3-Sulfopropyl potassium acrylate (molecular weight: 232) represented by the following formula

で表される、１分子内にアクリロイル基を６つ有する６官能アクリルモノマーである、ジペンタエリスリトールヘキサアクリレート（本発明における化合物Ｂ２に該当する）と、
造膜成分１の製造過程において、上記６官能アクリルモノマーとともに、少量製造される、下記式：

で表される、１分子内に５つのアクリロイル基と水酸基とを有する５官能アクリルモノマーである、ジペンタエリスリトールペンタアクリレート（本発明における化合物Ｂに該当する）と
の混合物（分子量：５７８、エチレン性不飽和基の官能基当量：９６（ｇ／ｅｑ）、水酸基価：１０（ｍｇＫＯＨ／ｇ）。 <Film forming component>
・Film forming component 1
The formula below:

Dipentaerythritol hexaacrylate (corresponding to compound B2 in the present invention), which is a hexafunctional acrylic monomer having six acryloyl groups in one molecule, represented by
In the production process of the film-forming component 1, the following formula, which is produced in a small amount together with the hexafunctional acrylic monomer:

A mixture of dipentaerythritol pentaacrylate (corresponding to compound B in the present invention) (molecular weight: 578, ethylenic Functional group equivalent of unsaturated group: 96 (g/eq), hydroxyl value: 10 (mgKOH/g).

・Film forming component 2
Acrylic acid ester copolymer having hydroxyl groups and acryloyl groups in side chains represented by the following formula (corresponding to compound B1-1 in the present invention. Solid content: 40 wt%; weight average molecular weight: 10500, ethylenic Functional group equivalent of unsaturated group: 314 (g/eq), hydroxyl value: 179 (mgKOH/g))

・Film-forming component 3
Acrylic acid ester copolymer having hydroxyl groups and acryloyl groups in side chains represented by the following formula (corresponding to compound B1-2 in the present invention. Solid content: 40 wt%; weight average molecular weight: 13000, ethylenic Functional group equivalent of unsaturated group: 218 (g/eq), hydroxyl value: 257 (mgKOH/g))

<Particle>
・ Organic particles 1: acrylic particles (average particle size 6 μm)
・ Organic particles 2: acrylic particles (average particle size 10 μm)
・ Organic particles 3: acrylic particles (average particle size 19 μm)
・ Organic particles 4: acrylic particles (average particle size 35 μm)
・ Organic particles 5: acrylic particles (average particle size 46 μm)
・ Inorganic particles 1: silica particles (average particle size 20-25 nm)
・ Inorganic particles 2: silica nanoparticles (average particle size 20 nm)
・ Inorganic particles 3: silica glass (average particle size 10 μm)

<Organic solvent>
・2-Methoxyethanol・Methanol・Ethanol・Acetone・MEK (methyl ethyl ketone)
・Ethyl acetate ・Butyl acetate ・THF (tetrahydrofuran)
・Toluene ・PEGMEA (Propylene Glycol Monomethyl Ether Acetate)

<Photoinitiator>
・Omnirad500 (manufactured by IGM)
Omnirad 500 is a mixture containing 50 wt% each of 1-hydroxycyclohexylphenyl ketone (molecular weight: 204) represented by the following formula (left side) and benzophenone (molecular weight: 182) represented by the following formula (right side).

・下記式で表される、アクリル酸（ＡＡ）（分子量：７２）

・下記式で表される、メタクリル酸メチル（ＭＭＡ）（分子量：１００）

<Other ingredients>
- 2-hydroxyethyl methacrylate (2-hydroxyethyl methacrylate, HEMA) (molecular weight: 130) represented by the following formula

・Acrylic acid (AA) (molecular weight: 72) represented by the following formula

- Methyl methacrylate (MMA) (molecular weight: 100) represented by the following formula

Preparation of composition A solution obtained by mixing each material (hydrophilic component, film-forming component, organic solvent, other components, and photopolymerization initiator described above) shown in Tables 1 and 2 in the amount (parts by weight) shown in the table. was stirred with a stirrer for 60 minutes. To this solution, the particles shown in Tables 1 and 2 were added in the amounts shown in the same tables and stirred for 5 minutes to prepare composition samples 1-52.

Evaluation 1: Evaluation of composition sagging (observation of uncured film)
Using a sag tester (Anti-Sag Meter 1-6 mils, manufactured by BYK), a composition sample (some selected from 1 to 52) was sprayed on a mount (Bikochart No. 2833, manufactured by BYK), and the thickness was 38.1 μm. The mount on which the (wet) coating of the composition sample having a thickness of 100.degree. Thereafter, the mount was taken out from the drying oven, the uncured film was observed, and whether or not the composition was sagging after coating and before curing was evaluated according to the following criteria.
◯: Sagging was not confirmed ×: Sagging was confirmed The results were as shown in Table 3.

Production of a three-dimensional member on which a cured film of the composition is formed An A4 size acrylic plate (Acrylite EX manufactured by Mitsubishi Chemical) is processed using an acrylic plate bending machine (HA-400 manufactured by Taiyo Denki Sangyo Co., Ltd.) to form a ceiling. A substrate having a surface size of about 210 x 260 mm, a vertical surface size of 210 x 30 mm, an edge R shape of φ5 mm, and an angle between the top surface and the vertical surface of 90° was prepared. bottom.
With the top surface of the substrate being horizontal, each composition sample was uniformly spray-coated on the top surface, edges and upright surfaces so that the film thickness was 20 μm. The substrate on which the (wet) coating of the composition sample was formed was quickly transferred to a hot air drying oven (DKN402 manufactured by YAMATO Scientific Co., Ltd.) and heated at a temperature of 70 ° C. for 10 minutes while maintaining the state that the top surface was horizontal. and the solvent was evaporated. After that, the base material was taken out from the hot air drying oven, and the uncured films on the top surface, the edge portions and the upright surfaces were irradiated with ultraviolet light (ANUP4154 manufactured by Panasonic Electric Works Co., Ltd.) with an accumulated light amount of 1000 mJ/cm ² to be cured. As described above, member samples 1 to 52 were produced in which a cured film of the composition was formed on the top surface, end portions, and vertical surfaces of the base material.

Evaluation The member samples 1 to 52 produced were evaluated as follows.

Evaluation 2: Evaluation of composition sagging (observation of cured film)
The appearance of the upright surface of each member sample was visually observed, and whether or not the cured film was in a non-uniform state due to sagging of the composition after application and before curing was evaluated according to the following criteria.
○: The cured film on the vertical surface was uniform △: Some gloss unevenness occurred on the surface of the cured film on the vertical surface ×: The film thickness at the bottom of the cured film on the vertical surface was thick The results are shown in Table 3. As indicated.

For the member samples for which the result of evaluation 2 was x, the evaluation of hydrophilicity and durability described later (evaluations 3 to 5) could not be performed.

Evaluation 3: Hydrophilic evaluation The static contact angle to water was measured for the top surface and vertical surface of each member sample. Specifically, using a portable contact angle meter PCA-11 (manufactured by Kyowa Interface Science Co., Ltd.), a water droplet of 1 μL was dropped on the top surface and vertical surface of each member sample at room temperature. Five points were measured on the top surface and the vertical surface of each member, and the average value of the values analyzed by the θ/2 method was taken as the value of the water contact angle, and the hydrophilicity was evaluated according to the following criteria.
Hydrophilicity is ○ when the water contact angle is 35° or less
When the water contact angle is 45° or less, hydrophilicity is △
When the water contact angle is greater than 45°, the hydrophilicity is ×
The results were as shown in Table 3.

Evaluation 4: Durability evaluation (rubbing resistance)
20 g of detergent containing abrasives (Ofuro no Look Polishing, manufactured by Lion) was dropped onto the top and vertical surfaces of each member sample, and a 3 kg load was applied using a resin brush (EKL0034, manufactured by TOTO). Rubbing was repeated 100 times. Then, the hydrophilicity evaluation of evaluation 3 was performed. The obtained water contact angle was evaluated according to the following criteria.
○: Water contact angle is 45° or less, difference in water contact angle before and after rubbing is less than 10° △: Water contact angle is 45° or less, difference in water contact angle before and after rubbing is 10° or more ×: Water contact angle of 45° or more The results were as shown in Table 3.

Evaluation 5: Durability evaluation (heat resistant water)
Each member sample was immersed in hot water at 80° C. for 24 hours. After that, the member sample was taken out from the hot water, and the change in the appearance of the top surface and upright surface of the member sample was confirmed and evaluated according to the following criteria.
◯: No change △: Slight change in appearance was observed by staring ×: Remarkable change in appearance such as cloudiness was observed The results were as shown in Table 3.

Claims (8)

a hydrophilic component comprising a compound A having a sulfonic acid group or a sulfonic acid group and at least one ethylenically unsaturated group in one molecule;
a film-forming component containing a compound B having three or more ethylenically unsaturated groups and a hydroxyl group in one molecule;
organic particles;
A hydrophilic composition comprising an organic solvent,
The film-forming component is
20% by weight or more in the hydrophilic composition,
The total hydroxyl value is greater than 15 [mgKOH/g] and less than 175 [mgKOH/g],
The weight average molecular weight is 1000 [g/mol] or more, and the functional group equivalent weight of the ethylenically unsaturated group is less than 242 [g/eq],
A hydrophilic composition, wherein the organic particles are contained in the hydrophilic composition in an amount of 1% by weight or more and less than 50% by weight with respect to the film-forming component. 2. The hydrophilic composition according to claim 1, wherein the ethylenically unsaturated groups possessed by said compound A and compound B are (meth)acryloyl groups. 3. The hydrophilic composition according to claim 1, wherein said organic particles are acrylic particles. 4. The film-forming component according to any one of claims 1 to 3, wherein the compound B contains a compound B1 which is an oligomer or polymer having an acrylic skeleton and having hydroxyl groups and three or more (meth)acrylate groups in side chains. The hydrophilic composition according to item 1. The hydrophilic composition according to any one of claims 1 to 4, wherein the organic particles have an average particle size of 1 µm or more and 50 µm or less. 6. The film-forming component according to any one of claims 1 to 5, further comprising compound B2, which is a polyfunctional (meth)acrylic monomer or oligomer having three or more functional groups in one molecule and no hydroxyl group. The hydrophilic composition according to the item. The hydrophilicity according to any one of claims 1 to 6, wherein the functional group equivalent of the ethylenically unsaturated group of the film-forming component is more than 103 [g/eq] and less than 242 [g/eq]. sex composition. The hydrophilic according to any one of claims 1 to 7, further comprising a volatile compound C having a smaller molecular weight than the compound A and having one ethylenically unsaturated group and a hydrophilic group in one molecule. sex composition.

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