Composition

Abstract

To provide a composition that can form a coating film having excellent hydrophilic property, antifogging property and antistatic property.SOLUTION: Provided is a composition that contains a particle containing polymer, and a liquid medium, and in which the polymer has a first repeating unit derived from an unsaturated carboxylic acid alkyl ester and a second repeating unit derived from a monomer represented by the following formula (1), and the inclusion ratio of the second repeating unit in the polymer is 7 mass% or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a composition. [Background technology]

[0002] There is a composition containing particles including a fluorine-containing polymer and a (meth)acrylic acid-based polymer as a coating material, and it has been reported that a coating film formed from this composition has excellent properties such as adhesion to a substrate and weather resistance (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-081884 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the above coating film contains a fluorine-containing polymer, it is highly hydrophobic and may not be able to exhibit sufficient performance as a coating material that requires anti-fogging and anti-static properties, and therefore there is a demand for a coating film that is excellent in hydrophilicity, anti-fogging properties and anti-static properties.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition capable of forming a coating film having excellent hydrophilicity, antifogging properties and antistatic properties. [Means for solving the problem]

[0006] The invention made to solve the above problem is a composition comprising particles containing a polymer and a liquid medium, the polymer having a first repeating unit derived from an unsaturated carboxylic acid alkyl ester and a second repeating unit derived from a monomer represented by the following formula (1), and the content of the second repeating unit in the polymer is 7 mass% or more. [ka] (In formula (1), R 1 is a hydrogen atom or a methyl group. + R is a group represented by the following formula (2-1) or (2-2). 2 is a divalent hydrocarbon group having 1 to 10 carbon atoms. n is an integer of 0 to 50. When n is 2 or more, multiple R 2 are the same or different. R 3 is a monovalent hydrocarbon group having 1 to 30 carbon atoms. [ka] (In formula (2-1), R 4 R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. 5 R is a monovalent hydrocarbon group having 1 to 10 carbon atoms. 6 is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms. In formula (2-2), R 7 R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. 8 , R 9 , R 10 and R 11 are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms. In formula (2-1) and formula (2-2), * indicates the bonding site with the oxygen atom in formula (1). Effect of the Invention

[0007] The composition of the present invention can form a coating film that is excellent in hydrophilicity, antifogging properties, and antistatic properties. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The composition of the present invention will be described in detail below.

[0009] The composition contains particles containing a polymer (hereinafter also referred to as "polymer particles [A]") and a liquid medium (hereinafter also referred to as "liquid medium [B]"). The composition may contain a crosslinking agent (hereinafter also referred to as "crosslinking agent [C]"). In addition, the composition may contain other components (hereinafter also referred to as "other components") other than the polymer particles [A], the liquid medium [B], and the crosslinking agent [C], within the scope of not impairing the effects of the present invention.

[0010] The composition can be suitably used to form a coating film. In other words, the composition can be suitably used as a coating film-forming composition. The term "coating film" refers to a film formed by applying the composition to the surface of a substrate and then curing the composition by drying or the like.

[0011] The substrate is not particularly limited, and examples thereof include resin substrates such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene, polycarbonate, and acrylic plate; glass substrates; and metal substrates such as SUS, steel plate, aluminum, and copper.

[0012] The method for applying the composition to a substrate is not particularly limited, and examples thereof include appropriate methods such as a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, an immersion method, a brush coating method, a spray coating, a roller coating, a bar coater, a knife coater, screen printing, a spin coater, an applicator, a flow coater, a centrifugal coater, an ultrasonic coater, and flexographic printing.

[0013] The composition can be suitably used as a paint, a coating agent, etc. In other words, the composition can be suitably used as a paint composition or a coating composition. "Paint, coating agent" refers to a fluid that is applied to the surface of a substrate to provide protection, beautification, or a unique function. A coating film formed by the composition has excellent hydrophilicity, antifogging properties, and antistatic properties.

[0014] When the composition does not contain a colorant such as a pigment, it can be used as a paint or coating agent for clear coating. In other words, the composition can be suitably used as a paint composition or coating composition for clear coating. In addition, the composition can also be used as an enamel paint, a colored coating agent, etc. by adding a colorant such as an inorganic or organic compound such as an inorganic pigment, an organic pigment, or a filler, as necessary, in order to impart additional functions to the coating film by coloring, etc.

[0015] Each component contained in the composition will be described below.

[0016] <[A] Polymer particles> The polymer particles [A] have a first repeating unit (hereinafter also referred to as "repeating unit (I)") derived from an unsaturated carboxylic acid alkyl ester and a second repeating unit (hereinafter also referred to as "repeating unit (II)") derived from a monomer represented by the following formula (1) described below. The polymer particles [A] preferably further have a third repeating unit (hereinafter also referred to as "repeating unit (III)") derived from a monomer forming an intra-particle crosslinked structure. The polymer particles [A] preferably further have a fourth repeating unit (hereinafter also referred to as "repeating unit (IV)") derived from a monomer forming an inter-particle crosslinked structure. The polymer particles [A] may have other repeating units (hereinafter simply referred to as "other repeating units") other than the repeating units (I) to (IV). The composition may contain one or more types of polymer particles [A].

[0017] The polymer particles [A] are usually latex-like particles dispersed in the liquid medium [B] using the liquid medium [B] as a dispersion medium.

[0018] Repeating unit (I) The repeating unit (I) is a repeating unit derived from an unsaturated carboxylic acid alkyl ester. The "unsaturated carboxylic acid alkyl ester" refers to an unsaturated carboxylic acid ester having a linear, branched or cyclic alkyl group. The polymer particles (A) may have one or more types of repeating units (I).

[0019] The unsaturated carboxylic acid constituting the unsaturated carboxylic acid alkyl ester is preferably an ethylenically unsaturated carboxylic acid. Examples of the ethylenically unsaturated carboxylic acid include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and ethylenically unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid. Among these, ethylenically unsaturated monocarboxylic acids are preferred, and acrylic acid or methacrylic acid is more preferred.

[0020] Examples of unsaturated carboxylate alkyl esters that provide the repeating unit (I) include unsaturated carboxylate esters having a straight-chain alkyl group such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, lauryl (meth)acrylate, etc.; unsaturated carboxylate esters having a branched-chain alkyl group such as 2-ethylhexyl (meth)acrylate; unsaturated carboxylate esters having a cyclic alkyl group such as cyclohexyl (meth)acrylate, etc. The term "(meth)acrylic acid" encompasses both "acrylic acid" and "methacrylic acid".

[0021] The lower limit of the content of the repeating unit (I) in the polymer particles [A] is preferably 60% by mass, more preferably 70% by mass, and even more preferably 80% by mass, based on the total repeating units constituting the polymer particles [A].The upper limit of the content is preferably 93% by mass, and more preferably 90% by mass.

[0022] [Repeating unit (II)] The repeating unit (II) is a repeating unit derived from a monomer represented by the following formula (1) (hereinafter also referred to as "monomer (1)") described later. Although it is not entirely clear, it is presumed that by the polymer particles [A] having the repeating unit (II), when a coating film is formed, the hydrophilic group possessed by the repeating unit (II) is exposed on the coating film surface, resulting in a coating film having excellent hydrophilicity, antifogging properties, and antistatic properties. The polymer particles [A] can have one or more types of repeating units (II).

[0023] (Monomer (1)) The monomer (1) is a compound represented by the following formula (1).

[0024] [ka]

[0025] In the above formula (1), R 1 is a hydrogen atom or a methyl group. + R is a group represented by the following formula (2-1) or (2-2) (hereinafter, also referred to as "group (X)"). 2 is a divalent hydrocarbon group having 1 to 10 carbon atoms. n is an integer of 0 to 50. When n is 2 or more, multiple R 2 are the same or different. R 3 is a monovalent hydrocarbon group having 1 to 30 carbon atoms.

[0026] The term "carbon number" refers to the number of carbon atoms constituting a group.

[0027] The term "hydrocarbon group" includes linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. This "hydrocarbon group" may be a saturated or unsaturated hydrocarbon group. The term "linear hydrocarbon group" refers to a hydrocarbon group that does not include a cyclic structure and is composed only of a linear structure, and includes both linear and branched hydrocarbon groups. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group that includes only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes both monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups. However, it is not necessary for the group to be composed only of an alicyclic structure, and it may include a linear structure as a part of the ring structure. The term "aromatic hydrocarbon group" refers to a hydrocarbon group that includes an aromatic ring structure as a ring structure. However, it is not necessary for the group to be composed only of an aromatic ring structure, and it may include a linear structure or an alicyclic structure as a part of the ring structure.

[0028] R 1 As the alkyl group, a methyl group is preferable.

[0029] R 2 Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms represented by the formula (I) include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group.

[0030] Examples of the divalent chain hydrocarbon group include alkanediyl groups such as methanediyl group, ethanediyl group, propanediyl group, and butanediyl group; alkenediyl groups such as ethenediyl group, propenediyl group, and butenediyl group; and alkynediyl groups such as ethynediyl group, propynediyl group, and butynediyl group.

[0031] Examples of the divalent alicyclic hydrocarbon group include monocyclic alicyclic saturated hydrocarbon groups such as a cyclopropanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, and a cyclohexanediyl group; monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopropenediyl group and a cyclobutenediyl group; polycyclic alicyclic saturated hydrocarbon groups such as a norbornanediyl group, an adamantanediyl group, and a tricyclodecanediyl group; and polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenediyl group and a tricyclodecenediyl group.

[0032] Examples of the divalent aromatic hydrocarbon group include arenediyl groups such as a benzenediyl group, a toluenediyl group, a xylylenediyl group, and a naphthalenediyl group; and arenediylalkanediyl groups such as a benzenediylmethanediyl group.

[0033] R 2 is preferably a divalent chain hydrocarbon group having 1 to 10 carbon atoms, more preferably an alkanediyl group having 1 to 10 carbon atoms, further preferably an alkanediyl group having 2 to 4 carbon atoms, and particularly preferably an ethanediyl group.

[0034] n is preferably 1 to 50, more preferably 1 to 30, and further preferably 5 to 20. When n is 2 or more, a plurality of R 2 are preferably the same.

[0035] R 3 Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms represented by the formula (I) include a monovalent chain hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.

[0036] Examples of the monovalent chain hydrocarbon group having 1 to 30 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, and tridecyl; alkenyl groups such as ethenyl, propenyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.

[0037] Examples of the monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms include monocyclic alicyclic saturated hydrocarbon groups such as a cyclopentyl group, a cyclohexyl group, etc.; polycyclic alicyclic saturated hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group, etc.; monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group, a cyclohexenyl group, etc.; and polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group, a tricyclodecenyl group, a tetracyclododecenyl group, etc.

[0038] Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group; and aralkyl groups such as a benzyl group, a phenethyl group, a naphthylmethyl group, and an anthrylmethyl group.

[0039] R 3 As the alkyl group, a monovalent chain hydrocarbon group having 1 to 30 carbon atoms is preferable, an alkyl group having 1 to 30 carbon atoms is more preferable, and a tridecyl group is further preferable.

[0040] (Group(X)) The group (X) is a group represented by the following formula (2-1) (hereinafter also referred to as "group (X-1)") or a group represented by the following formula (2-2) (hereinafter also referred to as "group (X-2)").

[0041] [ka]

[0042] In the above formula (2-1), R 4 R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. 5 R is a monovalent hydrocarbon group having 1 to 10 carbon atoms. 6 is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

[0043] In the above formula (2-2), R 7 R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. 8 , R 9 , R 10 and R 11 are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0044] In the above formulas (2-1) and (2-2), * indicates the bonding site with the oxygen atom in the above formula (1).

[0045] R 4 , R 5 , R 7 , R 8 , R 9, R 10 and R 11 Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by the formula (1) include R 3 Among the groups exemplified as the monovalent hydrocarbon group having 1 to 30 carbon atoms represented by the following formula, the same groups having 1 to 10 carbon atoms can be mentioned.

[0046] R 6 Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms represented by the formula (1) include R 2 Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms and represented by the following formula include the same groups as those exemplified above.

[0047] R 4 and R 5 is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, further preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably a methyl group.

[0048] R 6 is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms, more preferably an alkanediyl group having 1 to 10 carbon atoms, and further preferably an ethanediyl group.

[0049] R 7 , R 8 , R 9 , R 10 and R 11 is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, further preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably a methyl group.

[0050] The group (X) is preferably the group (X-1), in which case the antifogging and antistatic properties of the coating film formed from the composition can be further improved.

[0051] Examples of the monomer (1) include a compound represented by the following formula (A) (hereinafter also referred to as "monomer (1-1)") and a compound represented by the following formula (B) (hereinafter also referred to as "monomer (1-2)"):

[0052] [ka]

[0053] The monomer (1) is preferably the monomer (1-1), in which case the antifogging and antistatic properties of the coating film formed from the composition can be further improved.

[0054] The lower limit of the content of the repeating unit (II) in the [A] polymer particles is 7% by mass relative to the total repeating units constituting the [A] polymer particles. Although it is not necessarily clear, it is presumed that the [A] polymer particles have the repeating unit (II) and the content is 7% by mass or more, so that the proportion of hydrophilic groups exposed on the coating film surface when the coating film is formed increases, resulting in a coating film with excellent hydrophilicity, antifogging properties, and antistatic properties. The upper limit of the content is preferably 30% by mass, more preferably 20% by mass, and even more preferably 15% by mass relative to the total repeating units constituting the [A] polymer particles.

[0055] [Repeating unit (III)] The repeating unit (III) is a repeating unit derived from a monomer that forms an intraparticle crosslinked structure. The "intraparticle crosslinked structure" means a crosslinked structure formed inside the polymer particle [A]. The intraparticle crosslinked structure is formed, for example, during the synthesis of the polymer particle [A]. The polymer particle [A] can have one or more kinds of repeating units (III). When the polymer particle [A] has the repeating unit (III), the water resistance of the coating film formed by the composition can be improved.

[0056] Examples of monomers that form intra-particle crosslinked structures include monomers having two or more polymerizable unsaturated double bond-containing groups, such as divinylbenzene, allyl (meth)acrylate, and ethylene glycol di(meth)acrylate; monomers having a hydrolyzable silyl group that undergoes a hydrolysis condensation reaction, such as (meth)acryloxypropyltrimethoxysilane; (meth)acrylic acid esters containing an epoxy group, such as glycidyl (meth)acrylate; and acrylamide compounds, such as N-methoxymethyl (meth)acrylamide and N-hydroxymethyl (meth)acrylamide.

[0057] When the polymer particles [A] have the repeating unit (III), the lower limit of the content of the repeating unit (III) in the polymer particles [A] is preferably 0.1% by mass, more preferably 0.5% by mass, based on the total repeating units constituting the polymer particles [A].The upper limit of the content is preferably 20% by mass, more preferably 10% by mass, based on the total repeating units constituting the polymer particles [A].

[0058] [Repeating unit (IV)] The repeating unit (IV) is a repeating unit derived from a monomer that forms an interparticle crosslinked structure, and is preferably a repeating unit derived from a (meth)acrylic acid monomer that forms an interparticle crosslinked structure. The "interparticle crosslinked structure" refers to a crosslinked structure formed between a plurality of polymer particles [A]. The interparticle crosslinked structure is formed, for example, when a coating film is formed from the composition. The polymer particles [A] can have one or more types of repeating units (IV). When the polymer particles [A] have the repeating unit (IV), the water resistance of the coating film formed from the composition can be improved.

[0059] When the polymer particles [A] have a repeating unit (IV), the composition preferably contains a crosslinking agent [C]. The type of the crosslinking agent [C] can be appropriately selected depending on the crosslinkable group possessed by the repeating unit (IV).

[0060] Examples of monomers that form an interparticle crosslinked structure include monomers containing a hydroxyalkyl group, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; monomers containing a carboxy group, such as (meth)acrylic acid and 2-methacryloyloxyethyl succinic acid; monomers containing a carbonyl group, such as diacetone acrylamide and acetoacetoxyethyl methacrylate; and monomers containing an amino group, such as aminoethyl methacrylate.

[0061] When the polymer particles [A] have a repeating unit (IV), the lower limit of the content of the repeating unit (IV) in the polymer particles [A] is preferably 0.5% by mass, more preferably 1% by mass, based on the total repeating units constituting the polymer particles [A].The upper limit of the content is preferably 30% by mass, more preferably 10% by mass, based on the total repeating units constituting the polymer particles [A].

[0062] (Other repeating units) The other repeating units are repeating units other than the repeating units (I) to (IV), and examples thereof include polyalkylene glycol esters of unsaturated carboxylic acids, amino group-containing esters of unsaturated carboxylic acids, and repeating units derived from monomers described in WO 2014 / 112252, etc. The polymer particles [A] can have one or more types of other repeating units.

[0063] Examples of polyalkylene glycol esters of unsaturated carboxylic acids include polyalkylene glycol (meth)acrylate esters such as polyethylene glycol (meth)acrylate.

[0064] Examples of the amino group-containing ester of an unsaturated carboxylic acid include amino group-containing esters of (meth)acrylic acid such as 1,2,2,6,6-pentamethyl-4-piperidyl (meth)acrylate and dimethylaminoethyl (meth)acrylate.

[0065] When the polymer particles [A] have other repeating units, the lower limit of the content of the other repeating units in the polymer particles [A] is preferably 0.1% by mass, more preferably 0.5% by mass, and even more preferably 1% by mass, based on the total repeating units constituting the polymer particles [A].The upper limit of the content is preferably 20% by mass, more preferably 15% by mass, and even more preferably 10% by mass, based on the total repeating units constituting the polymer particles [A].

[0066] The lower limit of the content of the polymer particles [A] in the composition is preferably 70% by mass, more preferably 85% by mass, based on the total solid content of the composition. The upper limit of the content is, for example, 100% by mass, preferably 98% by mass. The "total solid content" of the composition refers to the sum of the components other than the liquid medium [B] of the composition.

[0067] The polymer particles (A) can be produced, for example, by emulsion polymerization of a predetermined monomer according to a known method, for example, by the method described in WO 2014 / 112252.

[0068] [[A] Physical properties of polymer particles] (Average particle size) The lower limit of the average particle size of the polymer particles [A] is preferably 30 nm, more preferably 50 nm, and even more preferably 80 nm. The upper limit of the average particle size is preferably 200 nm, and more preferably 100 nm. By having the average particle size of the polymer particles [A] within the above range, a coating film having excellent hydrophilicity, antifogging properties, and antistatic properties can be formed when the film is formed.

[0069] In this specification, the average particle size of the polymer particles [A] is the particle size (D50) value at which the cumulative frequency of the number of particles when accumulating particles starting from the smallest particle is 50% when the particle size distribution is measured using a particle size distribution measuring device that uses a light scattering method as the measurement principle. An example of such a particle size distribution measuring device is the "FPAR-1000" manufactured by Otsuka Electronics Co., Ltd. The particle size distribution measuring device can evaluate not only the primary particles of the polymer particles [A], but also the secondary particles formed by aggregation of the primary particles. Therefore, the particle size distribution measured by these particle size distribution measuring devices can be used as an index of the dispersion state of the polymer particles [A] contained in the composition.

[0070] (Tetrahydrofuran (THF) insolubles) The THF insoluble content of the polymer particles (A) is preferably 10% by mass or more, and more preferably 15% by mass or more.

[0071] (Endothermic peak temperature) The polymer particles [A] preferably have at least one endothermic peak in a temperature range of -50°C to +80°C when measured by differential scanning calorimetry (DSC) in accordance with JIS-K-7121: 2012. The temperature of one of the endothermic peaks possessed by the polymer particles [A] is more preferably in the range of -30°C to +70°C, and even more preferably in the range of -20°C to +60°C.

[0072] <[B] Liquid medium> [B] The liquid medium is preferably an aqueous medium containing water. This aqueous medium may contain a non-aqueous medium other than water. In order to improve the coating property of the composition, a non-aqueous medium having a normal boiling point of 60°C or more and 350°C or less may be contained. Specific examples of such non-aqueous media include amides such as N-methylpyrrolidone, dimethylformamide, and N,N-dimethylacetamide; hydrocarbons such as toluene, xylene, n-dodecane, and tetralin; alcohols such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, ethylene glycol, glycerin, propylene glycol, 2-ethyl-1-hexanol, 1-nonanol, and lauryl alcohol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, phorone, acetophenone, and isophorone; esters such as ethyl acetate, butyl acetate, benzyl acetate, isopentyl butyrate, methyl lactate, ethyl lactate, and butyl lactate; amines such as o-toluidine, m-toluidine, and p-toluidine; lactones such as γ-butyrolactone and δ-valerolactone; sulfoxides such as dimethyl sulfoxide, and sulfone compounds such as sulfolane.

[0073] When the liquid medium [B] contains water and a non-aqueous medium other than water, the lower limit of the water content in the liquid medium [B] is preferably 80% by mass, more preferably 90% by mass. By using an aqueous medium as the liquid medium [B], the composition has a lower adverse effect on the environment and is safer for workers who handle it.

[0074] <[C] Crosslinking agent> The composition may contain a crosslinking agent [C]. By containing the crosslinking agent [C] in the composition, the coating film can be densified by crosslinking, and water resistance can be imparted. It is preferable that the crosslinking agent [C] is dissolved in the liquid medium [B].

[0075] Examples of the crosslinking agent [C] include hydrazine derivatives, carbodiimide compounds, isocyanate compounds, amino compounds, epoxy compounds, alkoxysilyl group-containing compounds, metal crosslinking agents, oxazoline compounds, acid anhydrides, and aziridine compounds.

[0076] The hydrazine derivative may be, for example, a compound having at least two hydrazino groups. The lower limit of the content of the hydrazine derivative is preferably 0.02 mol, more preferably 0.2 mol, per mol of carbonyl group contained in the polymer particles [A]. The upper limit of the content is preferably 1.1 mol, more preferably 1.0 mol. If the content of the hydrazine derivative is less than 0.02 mol, or more than 1.1 mol, per mol of carbonyl group contained in the polymer particles [A], the water resistance and solvent resistance of the coating film formed may be insufficient.

[0077] Examples of the hydrazine derivative having at least two hydrazino groups include dihydrazide dicarboxylic acid having 2 to 10 carbon atoms, preferably 4 to 6 carbon atoms, such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, isophthalic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, and itaconic acid dihydrazide, and water-soluble aliphatic dihydrazine having 2 to 4 carbon atoms, such as ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, and butylene-1,4-dihydrazine. Among these, adipic acid dihydrazide is preferred. The hydrazine derivative has the effect of forming a coating having a network structure by reacting the carbonyl group of the polymer with the hydrazino group in the hydrazine derivative when the water in the composition is dispersed by drying. This crosslinking reaction usually does not require a catalyst, but if necessary, a water-soluble metal salt such as zinc sulfate, manganese sulfate, cobalt sulfate, or the like can be used as a catalyst.

[0078] Examples of commercially available carbodiimide compounds include "Carbodilite E-02", "Carbodilite E-03A", "Carbodilite E-04", "Carbodilite E-05", "Carbodilite V-02", "Carbodilite SV-02", "Carbodilite V-02-L2", "Carbodilite V-04", and "Carbodilite V-10" manufactured by Nisshinbo Chemical Co., Ltd. Among these, "Carbodilite V-02-L2", "Carbodilite V-02" and "Carbodilite E-05" are preferred.

[0079] Specific examples of isocyanate compounds include 2,4-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine methyl ester diisocyanate, methylcyclohexyl diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, n-pentane-1,4-diisocyanate, trimers thereof, adducts or biurets thereof, polymers thereof having two or more isocyanate groups, lysine triisocyanate, blocked isocyanates, etc. Commercially available isocyanate compounds include, for example, "Duranate WT30-100" by Asahi Kasei Corporation.

[0080] Specific examples of the epoxy compound include epoxy resins, epoxy-modified silane coupling agents, and the like.

[0081] Specific examples of alkoxysilyl group-containing compounds include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, 3-trimethoxysilylpropyl succinic anhydride, 3-isocyanatepropyltriethoxysilane, and tris-(trimethoxysilylpropyl)isocyanurate.

[0082] Specific examples of the metal-based crosslinking agent include organotitanium compounds such as titanium lactate, and zirconium compounds such as ammonium zirconium carbonate.

[0083] When the composition contains the crosslinking agent [C], the lower limit of the content of the crosslinking agent [C] is preferably 0.1 parts by mass, more preferably 1 part by mass, relative to 100 parts by mass of the polymer particles [A], and the upper limit of the content is preferably 20 parts by mass, more preferably 10 parts by mass.

[0084] Examples of the method for adding the crosslinking agent [C] include a method in which the crosslinking agent [C] is dissolved or dispersed in water and then added to the composition, a method in which the crosslinking agent [C] is dissolved in a small amount of a water-soluble organic solvent and then added to the composition, and a method in which the crosslinking agent [C] is directly added to the composition.

[0085] <Other optional ingredients> The composition may contain other optional components other than the polymer particles [A], the liquid medium [B], and the crosslinking agent [C], as necessary. Examples of the other optional components include matting agents, aqueous urethane resins, fillers, surface preparation agents, weather resistance improvers, thickeners, defoamers, film-forming assistants, antifreeze agents, pH adjusters, wettability improvers, pigments, etc. Commercially available products may also be used. The composition may contain one or more other optional components.

[0086] Examples of methods for adding other optional components include a method in which the other optional components are dissolved or dispersed in water and then added to the composition, a method in which the other optional components are dissolved in a small amount of a water-soluble organic solvent and then added to the composition, a method in which the other optional components are directly added to the composition, and a method in which the other optional components are added to the polymerization system when the polymer particles [A] are synthesized. EXAMPLES

[0087] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples in any way.

[0088] <[A] Synthesis of polymer particles> The abbreviations for the components used in the synthesis of the polymer particles (A) are shown below. MMA: Methyl methacrylate EHA: 2-Ethylhexyl acrylate CHMA: Cyclohexyl methacrylate Compound (A): A compound represented by the following formula (A): Compound (B): A compound represented by the following formula (B): MAPS: 3-(trimethoxysilyl)propyl methacrylate AMA: Allyl methacrylate DAAM: Diacetone acrylamide HEMA: 2-hydroxyethyl methacrylate AA: Acrylic acid PEGMA: polyethylene glycol methacrylate (NOF Corp.'s "PE-200", average oxyethylene addition mole number: 4.5) PMPMA: 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (ADEKA Corporation's "LA-82")

[0089] [ka]

[0090] In the following synthesis examples, unless otherwise specified, parts by mass refer to a value when the total mass of the monomers used is taken as 100 parts by mass.

[0091] [Synthesis Example 1] Synthesis of particles (S1) In a reaction vessel, 36.3 parts by mass of methyl methacrylate (MMA), 49.4 parts by mass of 2-ethylhexyl acrylate (EHA), 7 parts by mass of compound (A), 5 parts by mass of diacetone acrylamide (DAAM), 1.8 parts by mass of acrylic acid (AA), 0.5 parts by mass of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (PMPMA), 1.8 parts by mass of emulsifier (ADEKA Corporation's "ADEKA Reasoap SR1025") and 100 parts by mass of water were charged and thoroughly stirred to prepare a monomer emulsion. After charging 50 parts by mass of water into a separable flask, the temperature was raised in a water bath, and 0.3 parts by mass of ammonium persulfate as a polymerization initiator was added when the internal temperature of the separable flask reached 50°C. When the internal temperature of the separable flask reached 75° C., the addition of the monomer emulsion was started, and the monomer emulsion was slowly added over 2 hours while maintaining the internal temperature of the separable flask at 75° C. Thereafter, the internal temperature of the separable flask was raised to 85° C., and this temperature was maintained for 1 hour to carry out a polymerization reaction to polymerize a polymer. Thereafter, the separable flask was cooled to stop the reaction, ammonia water was added to adjust the pH to 7.6, and water was added to adjust the solid content concentration, and an aqueous dispersion containing 35% by mass of particles (S1) was obtained.

[0092] [Synthesis Examples 2-8] Synthesis of particles (S2)-(S8) Polymers were synthesized in the same manner as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 1 below were used, and aqueous dispersions containing 35 mass % of particles (S2) to (S8) were obtained.

[0093] <[A] Physical Properties of Polymer Particles> The average particle size, THF insoluble matter, and endothermic peak temperature of the polymer particles [A] synthesized above were measured by the following methods. The results are shown in Table 1 below.

[0094] [Average particle size] The particle size distribution of the obtained aqueous dispersion was measured using a particle size distribution measuring device (Otsuka Electronics Co., Ltd.'s "FPAR-1000") that uses dynamic light scattering as its measurement principle, and the average particle diameter (D50) was calculated from the particle size distribution.

[0095] [THF insolubles] About 10 g of the obtained aqueous dispersion was weighed into a petri dish made of Teflon (registered trademark) with a diameter of 8 cm, and dried at 120° C. for 1 hour to form a membrane. 1 g of the obtained membrane was immersed in 400 mL of tetrahydrofuran (THF) and shaken at 50° C. for 3 hours. Next, the THF phase was filtered through a 300-mesh wire screen to separate the insoluble matter, and the THF insoluble matter (mass %) was calculated from the measured value of the mass (Y(g)) of the residue obtained by evaporating and removing the THF solvent from the THF phase, using the following formula. THF insoluble content (mass%)=((1-Y) / 1)×100

[0096] [Endothermic peak temperature] The resulting aqueous dispersion was measured by a differential scanning calorimeter (DSC) and an endothermic peak was observed.

[0097] In Table 1 below, "-" indicates that the corresponding component was not used.

[0098] [Table 1]

[0099] <Preparation of Composition and Formation of Coating Film> The components other than the polymer particles (A) used in the preparation of the composition are shown below.

[0100] [[C] Crosslinking agent] (C-1): Adipic acid dihydrazide from Otsuka Chemical Co., Ltd. (C-2): "Carbodilite E-05" by Nisshinbo Chemical Co., Ltd. (C-3): "Duranate WT30-100" by Asahi Kasei Corporation

[0101] [Example 1] Preparation of coating composition (T1) and formation of coating film [A] 143 parts by mass of the aqueous dispersion containing particles (S1) as polymer particles (containing 50 parts by mass of particles (S1)) was added with 1.1 parts by mass of (C-1) as a crosslinking agent [C] and stirred at 300 rpm to prepare composition (T1). Composition (T1) was applied onto a PET film having a thickness of 50 μm using a bar coater and dried in a dryer at 80° C. for 10 minutes to form a coating film.

[0102] [Examples 2 to 8 and Comparative Examples 1 to 2] Coating compositions (T2) to (T8) and (CT1) to (CT2) were prepared and coating films were formed in the same manner as in Example 1, except that the types and amounts of each component shown in Table 2 below were used.

[0103] <Evaluation> The coating film formed above was evaluated for hydrophilicity, antifogging property, antistatic property and water resistance according to the following methods. The results are shown in Table 2. In Table 2, "-" indicates that the corresponding component was not used.

[0104] [Hydrophilicity] The contact angle with pure water of the coating film formed above was measured using "DropMaster DMo-502" by Kyowa Interface Science Co., Ltd. The contact angle with pure water is a value measured by the static method of JIS-R-3257 (1999). With regard to hydrophilicity, a contact angle with pure water of less than 30° was rated as "A" (good), a contact angle of 30° or more and less than 60° was rated as "B" (slightly poor), and a contact angle of 60° or more was rated as "C" (poor).

[0105] [Anti-fogging] 400mL of boiling water was poured into a 500mL beaker, and the PET film with the coating was placed on top of the beaker with the coating side facing down. After leaving it to stand for 10 seconds, the degree of clouding of the coating was visually observed. Anti-fogging properties were rated as "A" (very good) when no clouding was observed on the coating, "B" (good) when the coating was slightly cloudy but the bottom of the beaker was visible, and "C" (poor) when the coating was cloudy enough that the bottom of the beaker could not be seen.

[0106] [Antistatic properties] The surface resistivity (unit: Ω / □) of the coating film formed above was measured using a resistivity meter ("Hiresta UP MCP-HT450" manufactured by Nitto Seiko Analytech Co., Ltd.). 10 Those with a value of less than Ω / □ are rated "A" (very good) and those with a value of 10 10 Ω / □ or more 10 12 Those with a value of less than Ω / □ are rated "B" (good) and those with a value of 10 12 Those with Ω / □ or more were rated as "C" (poor).

[0107] [water resistance] After the anti-fog evaluation, the PET film was left at room temperature for 1 hour to thoroughly dry the surface, and the degree of whitening of the coating was then visually observed. No whitening was rated as "A" (very good), slight whitening was rated as "B" (good), and whitening over the entire surface was rated as "C" (poor).

[0108] [Table 2]

[0109] The results in Table 2 reveal that the coating films formed using the compositions of the Examples have superior hydrophilicity, antifogging properties, and antistatic properties compared to the coating films formed using the compositions of the Comparative Examples.

[0110] Furthermore, it has been clarified that when an intraparticle crosslinked structure and / or an interparticle crosslinked structure is formed in the polymer particles [A], the coating film has excellent water resistance.

Claims

1. Particles containing a polymer (excluding those containing a fluorine-containing polymer), A liquid medium; Crosslinking agent Contains The polymer has a first repeating unit derived from an unsaturated carboxylic acid alkyl ester, a second repeating unit derived from a monomer represented by the following formula (1), and a fourth repeating unit derived from a monomer that forms an inter-particle crosslinked structure: A composition in which the content of the second repeating unit in the polymer is 7% by mass or more. 【Chemistry 1】 (In formula (1), R １ is a hydrogen atom or a methyl group. ＋ R is a group represented by the following formula (2-1) or (2-2). ２ is a divalent hydrocarbon group having 1 to 10 carbon atoms. n is an integer from 0 to 50. When n is 2 or more, multiple R ２ are the same or different. ３ is a monovalent hydrocarbon group having 1 to 30 carbon atoms. 【Chemistry 2】 (In formula (2-1), R ４ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. ５ R is a monovalent hydrocarbon group having 1 to 10 carbon atoms. ６ is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms. In formula (2-2), R ７ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. ８ , R ９ , R １０ and R １１ are each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms. In formula (2-1) and formula (2-2), * indicates the bonding site with the oxygen atom in formula (1).

2. X in the above formula (1) ＋ The composition according to claim 1, wherein is a group represented by the above formula (2-1).

3. 3. The composition according to claim 1 or 2, wherein the polymer further comprises a third repeating unit derived from a monomer that forms an intraparticle crosslinked structure.

4. A composition described in claim 1, claim 2 or claim 3, wherein the average particle diameter of the particles is 30 nm or more and 100 nm or less.

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