Members for suppressing ice nucleus formation, frost formation, or snow and ice accumulation.

Abstract

Provided is a member that is for suppressing formation of ice nucleus, suppressing formation of frost, and suppressing accretion of snow and ice, and that has a coating film obtained through application of a coating composition containing a solvent and a polymer. The polymer contains: a graft polymer compound (A) that includes a structural unit represented by general formula (1) and that has a crosslinkable functional group (a); and a crosslinkable polymer compound (B) that has two or more reactive functional groups (b) that undergo a cross-linking reaction with the crosslinkable functional group (a). The content proportion of the crosslinkable polymer compound (B) in a total of 100 mass% of the graft polymer compound (A) and the crosslinkable polymer compound (B) is not less than 0.1 mass% but less than 50 mass%. The ice accretion stress of the member at -18°C is 150 kPa or less.

Description

[Technical Field]

[0001] The present invention relates to a member for suppressing ice nucleus formation, frost formation, or snow accumulation and ice formation. [Background technology]

[0002] In heat exchangers used in air conditioners and refrigerators, rapid cooling of the air can cause water droplets to adhere to the surface of the cooling components within the heat exchanger, or frost to form, which can reduce heat exchange efficiency. In particular, frost is formed through ice accumulation and the formation and growth of ice nuclei on the surface of the cooling components. As a method to suppress frost formation, a method of forming a resin film on the surface of the components is known, as described in Patent Document 1. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-158247 [Overview of the project] [Problems that the invention aims to solve]

[0004] This invention has been made in view of the above circumstances and aims to provide a component that can effectively suppress ice nucleation, frost formation, and snow accumulation. [Means for solving the problem]

[0005] In other words, the present invention provides a member for suppressing ice nucleus formation, frost formation, or snow and ice accumulation. [1] A component for suppressing ice nucleation, frost formation, or snow and ice accumulation, having a coating film obtained by applying a coating composition containing a solvent and a polymer, The polymer comprises a graft-type polymer compound (A) having a structural unit represented by the following general formula (1) and a crosslinkable functional group (a), and a crosslinkable polymer compound (B) having two or more reactive functional groups (b) that crosslink with the crosslinkable functional group (a). The content of the crosslinkable polymer compound (B) in the total 100% by mass of the graft-type polymer compound (A) and the crosslinkable polymer compound (B) is 0.1% by mass or more and less than 50% by mass. A component whose ice formation stress at -18°C is 150kPa or less. [ka] (In the above general formula (1), R1 represents a hydrogen atom or a methyl group, X represents O or NH, R2 represents any organic group, R3 and R4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group, and the carbon atoms to which R3 and R4 are bonded are tertiary or quaternary carbon atoms, n represents any number of repeats, and Polymer represents a graft chain containing constituent units derived from at least one graft monomer selected from the group consisting of (meth)acrylic acid monomers, (meth)acrylamide monomers, aromatic vinyl monomers, and (meth)acrylonitrile.) [2] The member according to [1], wherein the difference between the ice formation stress at -18°C and the ice formation stress at -8°C is 100 kPa or less. [3] The member according to [1] or [2], wherein the crosslinkable functional group (a) and the reactive functional group (b) are different groups from each other. [4] The member according to any one of [1] to [3], wherein the surface occupancy of the graft chains of the graft-type polymer compound (A) is 0.05 or more and less than 0.75. [5] The member according to any one of [1] to [4], wherein the number average molecular weight (Mn) of the crosslinkable polymer compound (B) is 5,000 to 3,000,000. [6] The member according to any one of [1] to [5], wherein the crosslinkable functional group (a) and the reactive functional group (b) are, each, at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a blocked isocyanate group, and an alkoxysilyl group. [7] The member according to any one of [1] to [6], wherein the number average molecular weight (Mn) of the graft-type polymer compound (A) is 10,000 to 1,000,000. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a member that can effectively suppress ice nucleation, frost formation, and snow accumulation. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram illustrating the test method for ice formation stress. [Modes for carrying out the invention]

[0008] The following describes in detail embodiments for carrying out the present invention (hereinafter referred to as "this embodiment"). The present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0009] The member of this embodiment is a member for suppressing ice nucleation, suppressing frost formation, or suppressing snow accumulation and ice, having a coating film obtained by applying a coating composition containing a solvent and a polymer. The polymer comprises a graft-type polymer compound (A) having a structural unit represented by the following general formula (1) and a crosslinkable functional group (a), and a crosslinkable polymer compound (B) having two or more reactive functional groups (b) that crosslink with the crosslinkable functional group (a). The content of the crosslinkable polymer compound (B) in the total 100% by mass of the graft-type polymer compound (A) and the crosslinkable polymer compound (B) is 0.1% by mass or more and less than 50% by mass. It is a member whose icing stress at -18°C is 150 kPa or less.

Chemical formula

[0010] The member of this embodiment has excellent snow and ice adhesion suppression effects, frost formation suppression effects, and ice nucleation suppression effects. The detailed reasons for obtaining such effects are not necessarily clear, but it is presumed to be as follows. In the member of this embodiment, there is a coating film obtained by applying a coating composition containing a solvent and a polymer. The graft-type polymer compound (A) as the polymer contained in the coating composition and the crosslinkable polymer compound (B) are capable of crosslinking reaction with each other. And by the crosslinking reaction of the graft-type polymer compound (A) and the crosslinkable polymer compound (B), the mobility of the graft chains contained in the graft-type polymer compound (A) can be increased, and thereby, it is presumed that it is easy to create a supercooled state or a non-freezing state. The member of this embodiment is presumed to have a highly mobile interface with respect to ice, frost, snow, etc. due to the presence of a coating film formed from such a coating composition. Also, due to the presence of a coating film formed from such a coating composition, water can be thermally moved without freezing even below the freezing point, so it is presumed that the freezing temperature of water on the member surface can be further lowered.

[0011] Furthermore, the member of this embodiment is presumed to have an excellent snow and ice accumulation suppression effect because water is less likely to freeze on the member surface, ice, frost, snow, etc. are less likely to form on the member surface, and it has a highly mobile interface with respect to ice, frost, snow, etc. Even if ice, frost, snow, etc. do form on the member surface, they slide off easily and are easily peeled off by external force. Furthermore, since the component of this embodiment can further lower the freezing temperature of water inside or on the surface of the component, it is presumed that it can lower the temperature at which ice nuclei form and thus has an excellent effect in suppressing ice nucleus formation.

[0012] <Coating composition> In the following, we will first describe the coating composition for forming the coating film that constitutes the component. The coating composition used in this embodiment contains a solvent and a polymer, As a polymer, A graft-type polymer compound (A) comprising a constituent unit represented by the above general formula (1) and having a crosslinkable functional group (a), A crosslinkable polymer compound (B) having two or more reactive functional groups (b) that crosslink with the crosslinkable functional group (a) of a graft-type polymer compound (A), Includes.

[0013] (Graft-type polymer compound (A)) Graft-type polymer compound (A) has a structural unit represented by general formula (1). Graft-type polymer compound (A) preferably contains the structural unit represented by general formula (1) as its main component, and the content of the structural unit represented by general formula (1) is preferably 80 to 95 mol% from the viewpoint of the mechanical strength of the coating film and the suppression of snow accumulation and ice. Graft-type polymer compound (A) is called, for example, a bottlebrush-type polymer or a cylinder-type polymer, and because the graft chain represented by Polymer in general formula (1) is densely bonded to the main chain, it has sufficient mobility and can also hold liquid substances well.

[0014] In general formula (1), R1 is a hydrogen atom or a methyl group, and X is O or NH, so the main chain of the graft polymer is formed by the polymerization of unsaturated groups such as (meth)acryloyloxy groups and (meth)acryloylamino groups. That is, the graft polymer compound (A) has a structure in which graft chains (side chains) represented by Polymer are grafted onto the main chain via linking groups. In general formula (1), X is preferably O, and the main chain of the graft polymer is preferably formed by the polymerization of (meth)acryloyloxy groups.

[0015] The graft polymer compound (A) may contain any constituent unit represented by general formula (1), and may also contain constituent units other than those represented by general formula (1) (other constituent units). As monomers constituting the other constituent units, conventionally known monomers that have unsaturated bonds and can be radically polymerized, such as vinyl groups, vinylidene groups, and vinylene groups, can be used.

[0016] In general formula (1), n ​​(number of repeats) is preferably 2 or more, and preferably 10 or more. By setting n to 2 or more, the main chain becomes more functional as a polymer. There is no particular upper limit to n (number of repeats), but it is preferably 10,000 or less. The constituent units represented by general formula (1) may be homopolymers or random polymers containing other constituent units. Furthermore, they may take the form of block structures, gradient structures, graft structures, multi-branched structures, etc.

[0017] In general formula (1), Polymer is a grafted chain attached to the main chain and contains constituent units derived from at least one graft monomer selected from the group consisting of (meth)acrylic acid monomers, (meth)acrylamide monomers, aromatic vinyl monomers, and (meth)acrylonitrile.

[0018] (meth)acrylic acid monomers include, Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, 2-methylpropane (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tetradecyl (meth)acrylate, octadecyl (meth)acrylate, behemopropyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, tetradecyl (meth)acrylate, octadecyl (meth)acrylate, behemopropyl (meth)acrylate, methyl (meth)acrylate, methyl (meth)acrylate, tetradecyl (meth)acrylate, octadecyl (meth)acrylate, behemopropyl (meth)acrylate Aliphatic, alicyclic, and aromatic alkyl (meth)acrylates such as nyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butylcyclohexylmethyl (meth)acrylate, isoboronyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, cyclodecyl (meth)acrylate, cyclodecylmethyl (meth)acrylate, benzyl (meth)acrylate, t-butylbenzotriazolephenylethyl (meth)acrylate, phenyl (meth)acrylate, naphthyl (meth)acrylate, and allyl (meth)acrylate;

[0019] Hydroxylated (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, and cyclohexanediol mono(meth)acrylate;

[0020] Mono(meth)acrylates of polyalkylene glycols such as poly(n=2 or more)ethylene glycol mono(meth)acrylate, poly(n=2 or more)propylene glycol mono(meth)acrylate, poly(n=2 or more) tetramethylene glycol mono(meth)acrylate, mono(meth)acrylate of mono or poly(n=2 or more) ethylene glycol mono or poly(n=2 or more) propylene glycol random copolymer, mono or poly(n=2 or more) ethylene glycol mono or poly(n=2 or more) propylene glycol block copolymer;

[0021] Mono(meth)acrylates of (polyalkylene) glycol monoalkyl, alkylene, alkyne ether or ester such as (poly)ethylene glycol monomethyl ether (meth)acrylate, (poly)ethylene glycol monooctyl ether (meth)acrylate, (poly)ethylene glycol monolauryl ether (meth)acrylate, (poly)ethylene glycol monostearyl ether (meth)acrylate, (poly)ethylene glycol monooleyl ether (meth)acrylate, (poly)ethylene glycol monostearate ester (meth)acrylate, (poly)ethylene glycol monononylphenyl ether (meth)acrylate, (poly)propylene glycol monomethyl ether (meth)acrylate, (poly)propylene glycol monoethyl ether (meth)acrylate, (poly)propylene glycol monooctyl ether (meth)acrylate, (poly)propylene glycol monolauryl ether (meth)acrylate, (poly)ethylene glycol (poly)propylene glycol monomethyl ether (meth)acrylate, etc.;

[0022] (Meth)acrylic acid monomers having a carboxyl group, such as monomers obtained by reacting acrylic acid, methacrylic acid, or hydroxyalkyl (meth)acrylate with acid anhydrides such as maleic anhydride, succinic anhydride, or phthalic anhydride; (Meth)acrylic acid monomers having a sulfonic acid group, such as ethyl (meth)acrylate sulfonate; (meth)acrylic acid monomers having a phosphate group, such as (di, tri)(meth)acryloyloxyethyl phosphate ester;

[0023] Oxygen atom-containing (meth)acrylates such as glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, oxetanylmethyl (meth)acrylate, morpholino (meth)acrylate, methylmorpholino (meth)acrylate, and methylmorpholinoethyl (meth)acrylate;

[0024] (Meth)acrylates having an amino group, such as 2-aminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, pentamethylpiperidyl (meth)acrylate, N-ethylmorpholino (meth)acrylate, trimethylaminoethyl (meth)acrylate chloride, diethylmethylaminoethyl (meth)acrylate chloride, benzyldimethylaminoethyl (meth)acrylate chloride, and trimethylaminoethyl (meth)acrylate methyl sulfate;

[0025] (meth)acrylates containing isocyanate groups, such as (meth)acryloyloxyethyl isocyanate and (meth)acryloyloxyethoxyethyl isocyanate; Blocked isocyanate-containing (meth)acrylates obtained by blocking the isocyanate groups with caprolactone, pyrazole compounds, MEK oxime, etc.

[0026] Alkoxysilyl group-containing (meth)acrylates such as 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane; These are some examples.

[0027] Examples of (meth)acrylamide monomers include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, and (meth)acryloylmorpholine.

[0028] Aromatic vinyl monomers include styrene, vinyltoluene, vinylhydroxybenzene, chloromethylstyrene, vinylnaphthalene, vinylbiphenyl, vinylethylbenzene, vinyldimethylbenzene, and α-methylstyrene.

[0029] In general formula (1), R2 represents any organic group. Examples of any organic group include alkylene groups such as ethylene and propylene; cycloalkylene groups such as cyclohexylene; poly(n=2 or more)alkylene glycol groups; polyester groups obtained by reacting or polymerizing a hydroxyl carboxylic acid with the terminal hydroxyl group of a poly(n=2 or more)alkylene glycol group; organic groups in which a hydroxyl group or acyl group is bonded to any position on these groups; and groups in which these groups are bonded by urethane bonds, urea bonds, etc. Among these, alkylene groups such as ethylene, propylene, butylene, and methylpropylene; polyethylene glycol and propylene glycol are preferred for reasons such as their versatility and ease of availability.

[0030] In general formula (1), R3 and R4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group. The carbon atoms to which R3 and R4 are bonded are tertiary or quaternary carbon atoms. Specific examples of ester groups bonded to R2 include the groups represented by the following formulas (1-1) to (1-6). The asterisk (*) in formulas (1-1) to (1-6) indicates the bond position with R2 in general formula (1). [ka]

[0031] The number-average molecular weight (Mn) of the graft-type polymer compound (A) is preferably 10,000 to 1,000,000, more preferably 20,000 to 800,000, and even more preferably 30,000 to 500,000 or less. Furthermore, the molecular weight distribution (dispersion degree PDI = Mw / Mn) of the graft-type polymer compound (A) is preferably 1.0 to 3.0, more preferably 1.3 to 3.0, and even more preferably 1.6 to 2.5. By having the number-average molecular weight of the graft-type polymer compound (A) within the above range, it is possible to effectively suppress the viscosity of the coating composition from becoming too high, which would make application to substrates difficult, while fully exhibiting the performance derived from the specific structure of the graft-type polymer compound (A). The number-average molecular weight (Mn) and molecular weight distribution (dispersion degree PDI) of the graft-type polymer compound (A) can be determined, for example, by gel permeation chromatography (GPC) measurement, in terms of polymethyl methacrylate.

[0032] The grafted polymer compound (A) may be either a case where the molecular weight of the polymer in the general formula (1) that forms the graft chain is small and the number of graft chains is large, or a case where the molecular weight of the polymer in the general formula (1) that forms the graft chain is large and the number of graft chains is small. However, the case where the molecular weight of the polymer in the general formula (1) that forms the graft chain is small and the number of graft chains is large is preferred because it is easier to control the surface occupancy within a suitable range, and it is desirable that the graft chain length is 10 to 40 monomers.

[0033] Furthermore, the graft-type polymer compound (A) has a crosslinkable functional group (a). The crosslinkable functional group (a) can be any functional group that exhibits crosslinking properties and is not particularly limited, but examples include carboxyl groups, phosphate groups, phosphate ester groups, hydroxyl groups, glycidyl groups, isocyanate groups, blocked isocyanate groups, alkoxysilyl groups, (meth)acryloyl groups, and halongen atoms. Among these, from the viewpoint of making the effects of the present invention even more pronounced, hydroxyl groups, isocyanate groups, blocked isocyanate groups, and alkoxysilyl groups are preferred, hydroxyl groups, isocyanate groups, and blocked isocyanate groups are more preferred, and hydroxyl groups and blocked isocyanates are even more preferred. Examples of alkoxysilyl groups include trimethoxysilyl groups, triethoxysilyl groups, and tripropoxysilyl groups.

[0034] The crosslinkable functional group (a) is introduced to crosslink with the reactive functional group (b) contained in the crosslinkable polymer compound (B) described later. By using a graft-type polymer compound (A) that has a crosslinkable functional group (a) and a crosslinkable polymer compound (B) that has two or more reactive functional groups (b) that crosslink with such a crosslinkable functional group (a), the coating film formed using the coating composition of the present invention can have enhanced mobility of the graft chains contained in the graft-type polymer compound (A). As a result, the formation of ice nuclei, frost formation, and snow and ice accumulation can be effectively suppressed in a component having such a coating film.

[0035] The crosslinkable functional group (a) may be contained in either the polymer backbone or the graft chain in the graft-type polymer compound (A), but from the viewpoint of reactivity, it is preferable that it be contained in the graft chain, and more preferably in the polymer chain represented by Polymer in general formula (1). There are no particular limitations on the method of introducing the crosslinkable functional group (a) into the graft-type polymer compound (A), but for example, one method is to use a monomer having the crosslinkable functional group (a) as the monomer for introducing the graft chain. For example, when the crosslinkable functional group (a) is a hydroxyl group, one method is to use a (meth)acrylate having a hydroxyl group or a mono(meth)acrylate of polyalkylene glycol. Furthermore, if the crosslinkable functional group (a) is an isocyanate group or a blocked isocyanate group, a method using an isocyanate group-containing (meth)acrylate or a blocked isocyanate group-containing (meth)acrylate can be used, and if the crosslinkable functional group (a) is an alkoxysilyl group, a method using an alkoxysilyl group-containing (meth)acrylate can be used. As a method for introducing the crosslinkable functional group (a) into the graft-type polymer compound (A), the functional group may be introduced by modification after the graft-type polymer has been prepared.

[0036] The amount of structural units derived from monomers having a crosslinkable functional group (a) in the graft chain is not particularly limited, but is preferably 1 to 20 mol%, more preferably 5 to 10 mol%.

[0037] Furthermore, in grafted polymer compound (A), if we consider the main chain as the central axis and extend the graft chains linearly from that central axis, and assume a plane (virtual outer periphery) containing the tips of the graft chains, the external shape of grafted polymer compound (A) can be considered as a cylinder with the plane containing the tips as its side surface. In grafted polymer compound (A) having such an external shape, as the length of the graft chains increases, the density of the graft chains on the side surface decreases, and the structural degree of freedom of the graft chains increases. As a result, the graft chains can be folded freely.

[0038] In a grafted polymer compound (A), the surface occupancy of the grafted chain (σ * ) can be calculated using the following formula.

number

[0039] In the above formula, DP n,graft x is the number-average degree of polymerization of the graft chains, x is the number of graft chains per unit length of the stem polymer (chains / nm), r is the radius of the backbone polymer (nm) (for example, 0.8 nm for poly-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PBIEM), a 2 The monomer cross-sectional area (nm) 2 (For example, methoxypoly(ethylene glycol) methacrylate (PEGMA) is 3.3 nm 2 ), l is the total length (nm) of the repeating unit of the polymer chain (for example, 0.25 in the case of polymethacrylate), and 2π (DP n,graft l+r) is the circumference (nm) of the cross-section of the grafted polymer compound (A), and l / x is the distance (nm) between adjacent graft chains. The above method can be found in Biomacromolecules, 2021, 22, 2505-14.

[0040] The surface occupancy rate of a graft chain is a value between 0 and 1. The larger the value, the greater the proportion of the polymer side surface occupied by the graft chain tip, and the more restricted the degree of freedom of the graft chain becomes. In other words, the surface occupancy rate of a graft chain is a value that reflects the degree of freedom of the graft chain, and the surface occupancy rate of a graft chain (σ) * The higher the ) value, the more the structural degrees of freedom of the graft chain are restricted. As a result, it is presumed that the graft chain can maintain a state where it extends approximately perpendicular to the main chain, and exhibits properties unique to that structure.

[0041] The surface occupancy of the graft chains of the graft polymer compound (A) is preferably 0.05 or more and less than 0.75, more preferably 0.10 or more and 0.65 or less, and even more preferably 0.20 or more and 0.50 or less. When the surface occupancy is within the above range, the density of the graft chains is within an appropriate range, so that the retention of the liquid substance is improved (especially for a liquid substance immiscible with water, the retention is greatly improved), and the suppression of ice nucleation by the size exclusion effect can be further improved.

[0042] The density of the graft chains of the graft polymer compound (A) is preferably 0.01 chain / nm 2 or more, more preferably 0.05 chain / nm 2 or more, even more preferably 0.1 chain / nm 2 or more, particularly preferably 0.2 chain / nm 2 or more. The upper limit is not particularly limited, but can be 1.0 chain / nm 2 or less, and can also be 0.9 chain / nm 2 or less.

[0043] The graft polymer compound (A) can be produced, for example, by polymerizing a polymer containing a structural unit derived from a monomer represented by the following general formula (2) in the presence of a copper catalyst or in the presence of at least one of a quaternary ammonium salt and a quaternary phosphonium salt that generates chlorine ions, bromine ions, or iodine ions, with at least one graft monomer selected from the group consisting of (meth)acrylic acid-based monomers, (meth)acrylamide-based monomers, aromatic vinyl-based monomers, and (meth)acrylonitrile.

Chemical formula

[0044] In general formula (2), the group represented by Y (halogen atom) is eliminated as a radical, and the carbon atom to which the halogen atom was bonded also becomes a radical. Then, the radical of the generated carbon atom reacts with the graft monomer to generate a radical. The eliminated halogen radical immediately bonds to the generated radical, stabilizing it. This stabilization of the generated radical makes termination reactions, such as coupling between radicals, less likely to occur. As a result, the graft monomer polymerizes sequentially, forming a graft chain represented by Polymer in general formula (1), and the desired graft polymer can be obtained. Here, by using a graft monomer containing a crosslinkable functional group (a), the crosslinkable functional group (a) can be introduced into the polymer chain represented by Polymer in general formula (1).

[0045] Alternatively, the desired graft-type polymer compound (A) can also be produced by polymerizing the macromonomer represented by the general formula (4) below. On the other hand, since the reaction sites of the macromonomer represented by the general formula (4) below are located at the ends of the polymer, unpolymerized macromonomers tend to remain, and the molecular weight of the resulting polymer does not increase easily. [ka] (In the above general formula (4), R1 to R4, X, and Polymer are equivalent to R1 to R4, X, and Polymer in the above general formula (1).)

[0046] In contrast, the aforementioned method, which uses a polymer containing constituent units derived from the monomer represented by the general formula (2) above (hereinafter also referred to as the "initiator polymer"), allows for the efficient production of the desired graft-type polymer compound (A).

[0047] Specific examples of monomers represented by the above general formula (2) include monomers represented by the following general formula (3). [ka] (In the above general formula (3), R1 and R2 are the same as R1 and R2 in the above general formula (1).)

[0048] The monomer represented by the general formula (3) above may be commercially available or synthesized. For example, the monomer represented by the general formula (3) can be synthesized by reacting a (meth)acrylate having a hydroxyl group or a glycidyl group with 2-bromo-2-methylpropionic acid (2-bromoisobutyric acid).

[0049] Furthermore, a polymer containing constituent units derived from the monomer represented by the general formula (2) above (initiator polymer) can also be obtained by polymerizing a (meth)acrylate having a hydroxyl group or a glycidyl group, and then reacting it with a carboxylic acid or derivative thereof having Y (chlorine atom, bromine atom, or iodine atom).

[0050] As the copper catalyst, a copper complex is preferred, more preferably a complex of a monovalent copper compound and an organic ligand is preferred, and even more preferably a combination of a complex of a monovalent copper compound and an organic ligand and a complex of a divalent copper compound and an organic ligand is preferred. Examples of monovalent copper compounds include cuprous chloride and cuprous bromide, and examples of divalent copper compounds include cupric chloride and cupric bromide. Examples of organic ligands include 2,2'-bipyridyl or its derivatives, 1,10-phenanthroline or its derivatives, polyamines (tetramethylethylenediamine, pentamethyldiethylenetriamine, hexamethyltris(2-aminoethyl)amine, etc.), and polycyclic alkaloids such as L-(-)-spartein. These copper compounds and organic ligands may be used individually or in combination of two or more. When using both monovalent and divalent copper compounds, the molar ratio of the monovalent copper compound to the divalent copper compound, based on copper content, is preferably 1:1 or more, more preferably 2:1 or more, and may be 100:1 or less, or 50:1 or less. When incorporating a copper complex in radical polymerization, the copper complex may be formed in advance before being used in radical polymerization, or the copper compound and organic ligand may be blended in a ratio that forms a copper complex before performing radical polymerization. In radical polymerization, the ratio of the copper compound to the organic ligand to be blended is preferably such that the number of moles of the organic ligand is 1:1 to 3:1, and more preferably 1.5:1 to 2.5:1, relative to the number of moles of the copper compound, in order to ensure that the organic ligand coordinates well with the copper compound and that the copper complex dissolves well.

[0051] Conventionally known compounds can be used as quaternary ammonium salts or quaternary phosphonium salts. These quaternary salts are preferably soluble in the polymerization solvent. These quaternary salts can be appropriately selected depending on the type of monomer and polymerization solvent used.

[0052] Examples of quaternary ammonium salts include tetramethylammonium salt, tetraethylammonium salt, tetrabutylammonium salt, methylimidazolium salt, and methylpyridinium salt. Examples of quaternary phosphonium salts include tetrabutylphosphonium salt, tributylmethylphosphonium salt, and triphenylmethylphosphonium salt.

[0053] When a graft monomer is reacted with an initiator polymer in the presence of an equimolar or greater copper catalyst (equoleom or greater number of copper atoms) or an equimolar or greater quaternary salt, all initiator groups undergo halogen exchange to form graft chains, and the desired graft-type polymer compound (A) can be obtained.

[0054] Graft polymers are preferably produced by solution polymerization in the presence of a polymerization solvent such as an organic solvent. Suitable polymerization solvents include anisole, hydrocarbon solvents, ketone solvents, alcohol solvents, glycol solvents, amide solvents, ester solvents, urea solvents, and ionic liquids. In particular, it is preferable to use at least a portion of a highly polar solvent capable of dissolving copper complexes or quaternary salts and performing halogen exchange. Examples of such polymerization solvents include anisole; alcohol solvents such as methanol, ethanol, and isopropanol; glycol solvents such as ethylene glycol, propylene glycol, glycerin, diethylene glycol, and propylene glycol monomethyl ether; amide solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide; sulfoxide solvents such as dimethyl sulfoxide; and ionic liquids such as imidazolium salts and quaternary ammonium salts.

[0055] The amount of polymerization solvent used during polymerization is preferably 30 to 80% by mass, and more preferably 40 to 70% by mass, based on the entire polymerization reaction system. If the amount of polymerization solvent is less than 30% by mass, the amount of solids may be too high, resulting in excessively high viscosity. On the other hand, if the amount of polymerization solvent exceeds 80% by mass, the monomer concentration may become too low, potentially reducing the polymerization rate. The graft-type polymer compound (A) may be used as is (dissolved in the polymerization solvent), or it may be precipitated in a poor solvent, removed, and then dissolved in another solvent before use.

[0056] Furthermore, the graft polymer compound (A) can also be produced by forming a graft polymer as an intermediate using the same method as described above, and then modifying its graft chain. For example, after forming a graft polymer as an intermediate (where the graft chain is a precursor of the polymer chain represented by Polymer in general formula (1)) using the same method as described above, the graft chain can be modified using a compound containing a crosslinkable functional group (a) to form a graft chain containing a crosslinkable functional group (a) (a polymer chain represented by Polymer in general formula (1)). In this method, the graft polymer as an intermediate (and the graft monomer for forming it) does not need to contain a crosslinkable functional group (a).

[0057] The method for modifying the graft chain is not limited. For example, if a graft monomer for forming a graft-type polymer as an intermediate is referred to as the first graft monomer, the graft chain may be extended by further carrying out a graft polymerization reaction using a second graft monomer different from the first graft monomer after obtaining the graft-type polymer as an intermediate. It is preferable to use at least one graft monomer selected from the group consisting of (meth)acrylic acid monomers, (meth)acrylamide monomers, aromatic vinyl monomers, and (meth)acrylonitrile as the second graft monomer. It is also preferable to use a second graft monomer that contains a crosslinkable functional group (a).

[0058] (Crosslinkable polymer compound (B)) Next, we will explain the crosslinkable polymer compound (B). The crosslinkable polymer compound (B) is a polymer having two or more reactive functional groups (b) that crosslink with the crosslinkable functional group (a) contained in the graft-type polymer compound (A) described above.

[0059] The reactive functional group (b) can be any group capable of crosslinking with the crosslinkable functional group (a), and is not particularly limited, but examples include carboxyl groups, phosphate groups, phosphate ester groups, hydroxyl groups, glycidyl groups, isocyanate groups, blocked isocyanate groups, alkoxysilyl groups, (meth)acryloyl groups, and halongen atoms. Among these, from the viewpoint of making the effects of this embodiment even more pronounced, hydroxyl groups, isocyanate groups, blocked isocyanate groups, and alkoxysilyl groups are preferred, hydroxyl groups, isocyanate groups, and blocked isocyanate groups are more preferred, and hydroxyl groups and blocked isocyanate groups are even more preferred. Examples of alkoxysilyl groups include trimethoxysilyl groups, triethoxysilyl groups, and tripropoxysilyl groups. For example, if the crosslinkable functional group (a) is a hydroxyl group, the reactive functional group (b) can be an isocyanate group or a blocked isocyanate group. Furthermore, if the crosslinkable functional group (a) is an isocyanate group or a blocked isocyanate group, the reactive functional group (b) can be a hydroxyl group, and if the crosslinkable functional group (a) is an alkoxysilyl group, the reactive functional group (b) can be an alkoxysilyl group.

[0060] In this embodiment, the crosslinkable polymer compound (B) contains two or more crosslinkable functional groups (a) and reactive functional groups (b) capable of crosslinking, thereby allowing multiple graft-type polymer compounds (A) to be suitably crosslinked by the crosslinkable polymer compound (B). This enhances the mobility of the graft chains contained in the graft-type polymer compound (A), and as a result, a component having a coating film formed using the coating composition of this embodiment can effectively suppress ice nucleation, frost formation, and snow and ice accumulation.

[0061] The crosslinkable polymer compound (B) may contain two or more reactive functional groups (b). Examples of crosslinkable polymer compounds (B) include copolymers of monomers having reactive functional groups (b) and monomers copolymerizable with such monomers; and bio-derived polymers such as cellulose nanofibers, chitosan, and polylactic acid. When the crosslinkable polymer compound (B) is the above copolymer, from the viewpoint of crosslinkability, it is preferable that it contains 1 to 20 mol% of structural units derived from monomers having reactive functional groups (b), and more preferably 5 to 10 mol% of structural units derived from monomers having reactive functional groups (b). The bio-derived polymer such as cellulose nanofibers used as the crosslinkable polymer compound (B) is preferably subjected to oxidation treatment or other methods to improve its dispersion stability in the solvent as needed.

[0062] Furthermore, the reactive functional group (b) can be any group that can crosslink with the crosslinkable functional group (a) contained in the graft-type polymer compound (A). The reactive functional group (b) may be the same group as the crosslinkable functional group (a) or a different group. However, from the viewpoint of further enhancing the effect of suppressing ice nucleation, frost formation, and snow accumulation, it is preferable that the crosslinkable functional group (a) and the reactive functional group (b) are different groups. More specifically, it is preferable that the crosslinkable functional group (a) and the reactive functional group (b) are different groups, and that crosslinking is possible between the crosslinkable functional group (a) and the reactive functional group (b), but not between the crosslinkable functional groups (a) themselves, or between the reactive functional groups (b) themselves. As for the combination of the crosslinkable functional group (a) and the reactive functional group (b), it is preferable that the crosslinkable functional group (a) is a hydroxyl group and the reactive functional group (b) is an isocyanate group or a blocked isocyanate.

[0063] The number-average molecular weight (Mn) of the crosslinkable polymer compound (B) is not particularly limited, but from the viewpoint of further enhancing the effect of suppressing ice nucleation, frost formation, and snow accumulation, it is preferably 5,000 to 3,000,000, more preferably 10,000 to 1,000,000, and even more preferably 15,000 to 500,000. By having the molecular weight of the crosslinkable polymer compound (B) within the above range, the resulting coating film can have appropriate strength. Furthermore, the molecular weight distribution (dispersion degree PDI = Mw / Mn) of the crosslinkable polymer compound (B) is preferably 1.0 to 4.0, more preferably 1.2 to 3.0. The number-average molecular weight (Mn) and molecular weight distribution (dispersion degree PDI) of the crosslinkable polymer compound (B) can be determined, for example, by gel permeation chromatography (GPC) measurement in terms of polymethyl methacrylate. Furthermore, the crosslinkable polymer compound (B) can be a linear polymer without graft chains (for example, a linear polymer with an average molecular weight of 600 or less in its side chains). The mass-average molecular weight (Mw) can also be determined by multiplying the number-average molecular weight (Mn), which is calculated in terms of polymethyl methacrylate by gel permeation chromatography (GPC), by the molecular weight distribution (dispersion degree PDI = Mw / Mn).

[0064] The method for producing the crosslinkable polymer compound (B) is not particularly limited, but for example, if the crosslinkable polymer compound (B) has structural units derived from a monomer having a reactive functional group (b), it can be produced by copolymerizing a monomer having a reactive functional group (b) with a monomer copolymerizable with such a monomer.

[0065] As monomers having a reactive functional group (b) and copolymerizable monomers, the monomers exemplified above as monomers for forming the graft chain of the graft polymer compound (A) can be used. That is, (meth)acrylic acid monomers, (meth)acrylamide monomers, aromatic vinyl monomers, and (meth)acrylonitrile, which were exemplified above as monomers for forming the graft chain of the graft polymer compound (A), can be used. For example, as (meth)acrylic acid monomers, the following can be used: aliphatic, alicyclic, or aromatic alkyl (meth)acrylates; (meth)acrylates having hydroxyl groups; mono(meth)acrylates of polyalkylene glycols; mono(meth)acrylates of (polyalkylene) glycol monoalkyl, alkylene, alkyne ether, or ester; (meth)acrylic acid monomers; (meth)acrylic acid monomers having sulfonic acid groups; (meth)acrylic acid monomers having phosphate groups; oxygen atom-containing (meth)acrylates; amino group-containing (meth)acrylates; isocyanate-containing (meth)acrylates; blocked isocyanate-containing (meth)acrylates; alkoxysilyl-containing (meth)acrylates; and the like.

[0066] For example, if the reactive functional group (b) is an isocyanate group or a blocked isocyanate group, a crosslinkable polymer compound (B) can be produced by copolymerizing an isocyanate group-containing (meth)acrylate or a blocked isocyanate-containing (meth)acrylate as the monomer having the reactive functional group (b), and a monomer that does not have the reactive functional group (b) (for example, aliphatic, alicyclic, aromatic alkyl (meth)acrylate, or mono(meth)acrylate of (polyalkylene) glycol monoalkyl, alkylene, alkyne ether, or ester) as the copolymerizable monomer. Furthermore, if the reactive functional group (b) is a hydroxyl group, a crosslinkable polymer compound (B) can be produced by using a (meth)acrylate or mono(meth)acrylate of polyalkylene glycol having a hydroxyl group as the monomer possessing the reactive functional group (b), and copolymerizing it with a monomer that does not have the reactive functional group (b) as the copolymerizable monomer. Moreover, if the reactive functional group (b) is an alkoxysilyl group, a crosslinkable polymer compound (B) can be produced by using an alkoxysilyl group-containing (meth)acrylate as the monomer possessing the reactive functional group (b), and copolymerizing it with a monomer that does not have the reactive functional group (b) as the copolymerizable monomer.

[0067] In this case, it is preferable to use monomers that have the same or similar skeleton as the graft chains constituting the graft polymer compound (A) as copolymerizable monomers, from the viewpoint of affinity with the graft polymer compound (A). For example, if the graft chains constituting the graft polymer compound (A) are obtained by polymerizing mono(meth)acrylate having a polyalkylene glycol skeleton, it is preferable to use mono(meth)acrylate having a polyalkylene glycol skeleton as the copolymerizable monomer for forming the crosslinkable polymer compound (B). The reactive functional group (b) of the crosslinkable polymer compound (B) may be a functional group derived from the monomer used in the above method, or it may be a functional group introduced by modification using the functional group of the monomer used in the above method.

[0068] The ratio of structural units derived from monomers having a reactive functional group (b) to structural units derived from copolymerizable monomers in the crosslinkable polymer compound (B) is not particularly limited and can be appropriately selected depending on the number-average molecular weight of the crosslinkable polymer compound (B) and the amount of reactive functional group (b) to be introduced. However, the molar ratio of "structural units derived from monomers having a reactive functional group (b): structural units derived from copolymerizable monomers" is preferably 1:100 to 20:100, more preferably 3:100 to 10:100, and even more preferably 5:100 to 10:100.

[0069] When producing the crosslinkable polymer compound (B), it is preferable to produce it by solution polymerization in the presence of a polymerization solvent such as an organic solvent. Suitable polymerization solvents include anisole, hydrocarbon solvents, ketone solvents, alcohol solvents, glycol solvents, amide solvents, ester solvents, urea solvents, and ionic liquids. Among these, it is preferable to use at least a portion of a highly polar solvent capable of dissolving quaternary salts and performing halogen exchange. Examples of such polymerization solvents include alcohol solvents such as anisole, methanol, ethanol, and isopropanol; glycol solvents such as ethylene glycol, propylene glycol, glycerin, diethylene glycol, and propylene glycol monomethyl ether; amide solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide; sulfoxide solvents such as dimethyl sulfoxide; and ionic liquids such as imidazolium salts and quaternary ammonium salts.

[0070] The amount of polymerization solvent used during polymerization is preferably 30 to 80% by mass, and more preferably 40 to 70% by mass, based on the entire polymerization reaction system. If the amount of polymerization solvent is less than 30% by mass, the amount of solids may be too high, resulting in excessively high viscosity. On the other hand, if the amount of polymerization solvent exceeds 80% by mass, the monomer concentration may become too low, potentially reducing the polymerization rate. The crosslinkable polymer compound (B) may be used as is (dissolved in the polymerization solvent), or it may be precipitated in a poor solvent, extracted, and then dissolved in another solvent before use. Furthermore, known polymerization initiators can be used as appropriate.

[0071] (solvent) The coating composition used in this embodiment contains a solvent. As the solvent, for example, in addition to organic solvents that can be used in the solution polymerization described above, water may also be used. Specific examples of solvents include anisole; alcohol-based solvents such as methanol, ethanol, and isopropanol; glycol-based solvents such as ethylene glycol, propylene glycol, glycerin, diethylene glycol, and propylene glycol monomethyl ether; amide-based solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide; ionic liquids such as imidazolium salts and quaternary ammonium salts; hydrocarbon-based solvents such as toluene, xylene, hexane, isoparaffin, and anisole; ketone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester-based solvents such as ethyl acetate, propyl acetate, butyl acetate, ethylene glycol dilauric acid, and trimethylolpropane triacetate; and esterified glycol-based solvents such as propylene glycol monomethyl ether acetate and 3-methoxy-3-methyl-1-butyl acetate.

[0072] (Method for preparing a coating composition) The coating composition of this embodiment can be prepared by mixing a polymer containing the above-described graft-type polymer compound (A) and crosslinkable polymer compound (B) with a solvent.

[0073] In the coating composition of this embodiment, the content of the crosslinkable polymer compound (B) is 0.1% by mass or more and less than 50% by mass, preferably 0.5 to 40% by mass, and more preferably 1 to 30% by mass, based on 100% by mass of the total of the graft-type polymer compound (A) and the crosslinkable polymer compound (B). When the crosslinkable polymer compound (B) is cellulose nanofiber, the above content is even more preferably 20% by mass or less, particularly preferably 15% by mass or less, and most preferably 12% by mass or less. If the amount of crosslinkable polymer compound (B) is too little or too much, the effect of suppressing ice nucleation, frost formation, and snow accumulation of ice in the resulting material will be insufficient.

[0074] The content ratio of the polymers containing the graft-type polymer compound (A) and the crosslinkable polymer compound (B) in the coating composition of this embodiment is not particularly limited, but from the viewpoint of coating film formation, it is preferably 1 to 20% by mass, more preferably 2 to 10% by mass.

[0075] Furthermore, the coating composition of this embodiment may contain a catalyst for crosslinking the crosslinkable functional group (a) of the graft-type polymer compound (A) with the reactive functional group (b) of the crosslinkable polymer compound (B). The catalyst can be appropriately selected depending on the types of crosslinkable functional group (a) and reactive functional group (b). If either the crosslinkable functional group (a) or the reactive functional group (b) is a hydroxyl group and the other is an isocyanate group or a blocked isocyanate group, then organotin compounds such as dibutyltin dilaurate and dioctyltin dilaurate; metal catalysts such as bismuth compounds; base catalysts such as organic amines; urethane reaction catalysts such as DMC catalysts; etc. can be used. Also, if both the crosslinkable functional group (a) and the reactive functional group (b) are trialkoxysilyl groups, then a base catalyst or an acid catalyst can be used.

[0076] The coating composition of this embodiment may also be a composition for forming a substantially transparent (clear) coating film, and may contain various additives as needed. For example, it may contain colorants such as dyes and pigments, pigment dispersants, defoamers, leveling agents, preservatives, ultraviolet absorbers, light stabilizers, thickeners, photoinitiators, photoacid generators, photobase generators, photosensitizers, antibacterial agents, antifungal agents, antifogging agents, water repellents, antistatic agents, conductive agents, reinforcing materials, fibrous materials, and other polymer components.

[0077] <Components> The component of this embodiment is a component for suppressing ice nucleation, frost formation, or snow accumulation and ice, and has a coating film obtained by applying the above-mentioned coating composition, and has an ice accumulation stress of 150 kPa or less at -18°C.

[0078] The component of this embodiment is formed, for example, by applying the above-described coating composition onto a substrate (carrier). The substrate (carrier) is not particularly limited, but can be appropriately selected from organic materials, inorganic materials, metallic materials, etc.

[0079] The organic material is not particularly limited, and various resins and rubbers can be used without restriction. The resin may be either a thermosetting resin or a thermoplastic resin. Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, polyurethane resins, urea resins, melamine resins, thermosetting polyimide resins, and diallyl phthalate resins. Examples of thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polycycloolefin; vinyl resins such as polystyrene, acrylic resins, polyvinyl chloride resins, and polyvinyl alcohol; fluororesins such as polytetrafluoroethylene; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and polyethylene naphthalate; and silicone resins such as polydimethylsiloxane. Examples of rubbers include diene-based rubbers such as butadiene rubber, styrene-butadiene rubber, chloroprene rubber, isoprene rubber, natural rubber, nitrile rubber, and butyl rubber; and other rubbers besides diene-based rubbers such as ethylene propylene rubber, acrylic rubber, polyether rubber, polyurethane rubber, fluororubber, and silicone rubber.

[0080] Furthermore, the types of substrates are not particularly limited and include tubes, sheets, fibers, strips, films, plates, foils, membranes, pellets, powders, particles, and molded products (e.g., extruded products, cast products, etc.).

[0081] Furthermore, the substrate may be one that has affinity for the graft-type polymer compound (A) and / or the crosslinkable polymer compound (B), or the substrate may be one that has been surface-treated to increase its affinity for the graft-type polymer compound (A) and / or the crosslinkable polymer compound (B). For example, the substrate may be surface-treated with a silane coupling agent such as 3-(2-aminoethylaminopropyl)trimethoxysilane. In addition, a primer layer may be formed on the substrate to increase its affinity for the graft-type polymer compound (A) and / or the crosslinkable polymer compound (B), and the primer layer may be, for example, a layer made of the crosslinkable polymer compound (B).

[0082] Furthermore, when forming a coating film on a substrate, a composition may be prepared by mixing the above-mentioned graft-type polymer compound (A) and a solvent, containing a polymerization initiator and a monomer for forming a crosslinkable polymer compound (B) in a solution; applying such a composition to the substrate to form a coating film layer; and within the coating film layer on the substrate, polymerizing the monomer for forming the crosslinkable polymer compound (B) in the solution of the graft-type polymer compound (A) and the solvent to form the crosslinkable polymer compound (B), thereby forming a layer consisting of the coating composition of the present invention (i.e., the crosslinkable polymer compound (B) may be formed in situ).

[0083] Furthermore, the coating film formed on the substrate may contain a liquid substance. Examples of liquid substances include water, ionic liquids, fluorinated solvents, and oils (hydrocarbon oils, silicone oils, etc.), and it is preferable that it be at least one selected from water and ionic liquids. The liquid substance may be hydrophilic or hydrophobic. Examples of hydrophilic liquid substances include water and hydrophilic ionic liquids. Examples of hydrophobic liquid substances include hydrophobic ionic liquids, fluorinated solvents, and oils. The liquid substance may consist of only one type of liquid substance, or it may be a mixture of two or more types of liquid substances. The liquid substance may contain additives. In this embodiment, all or part of the solvent contained in the coating composition may be left as part of the liquid substance contained in the coating film.

[0084] Ionic liquids, also called ionic liquids or room-temperature molten salts, are low-melting-point salts with ionic conductivity. Most ionic liquids are obtained by combining organic onium ions as cations with organic or inorganic anions, resulting in relatively low melting points. The melting point of ionic liquids is usually 100°C or below, preferably room temperature (25°C) or below. The melting point of ionic liquids can be measured using a differential scanning calorimeter (DSC) or similar device. Any known ionic liquid can be used without limitation.

[0085] In the component of this embodiment, it is preferable that the liquid substance contained within the coating film remains in a liquid state even at temperatures below the freezing point (preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -30°C or lower). Whether the liquid substance is in a liquid state can be confirmed by differential scanning calorimetry. If it cannot be confirmed by differential scanning calorimetry, it can be confirmed by an indentation test.

[0086] The component of this embodiment can reduce the difference between the ice formation stress at -8°C and the ice formation stress at -18°C, and from the viewpoint of having an excellent effect in suppressing ice nucleation, frost formation, and snow and ice formation around -18°C, it is preferable that at -18°C, the ratio of liquid substance to 100 parts by mass of the total of the graft-type polymer compound (A) and crosslinkable polymer compound (B) contained in the coating film is 50 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and particularly preferably 90 parts by mass or more. The above ratio can be adjusted by the combination of graft chains constituting the graft-type polymer compound (A) and liquid substance. Furthermore, the above ratio can be measured by atomic force microscopy or ellipsometry.

[0087] Furthermore, in the member of this embodiment, the thickness of the dry coating film formed by the coating composition is preferably 10 nm or more, more preferably 50 nm or more, even more preferably 100 nm or more, and particularly preferably 1000 nm or more, from the viewpoint of being superior in suppressing ice nucleation, frost formation, and snow accumulation and ice formation. There is no particular upper limit, but it can be 10 μm or less, or 100 μm or less. The thickness of the coating film formed by the coating composition can be measured by ellipsometry or the like. The thickness of the coating film may also be the value measured at -18°C.

[0088] The member of this embodiment has an ice formation stress of 150 kPa or less at -18°C, preferably 120 kPa or less, more preferably 100 kPa or less, even more preferably 80 kPa or less, even more preferably 65 kPa or less, especially preferably 50 kPa or less, particularly preferably 35 kPa or less, and most preferably 20 kPa or less. The ice formation stress at -18°C can be measured by the method described in the examples below.

[0089] The ice formation stress at -18°C mentioned above can be adjusted by the type of graft polymer compound (A), the type of crosslinkable polymer compound (B), the presence and type of liquid substance, and the surface occupancy rate of the polymer chains of the graft polymer compound (A).

[0090] The ice-forming stress of the member of this embodiment at -8°C is preferably 10 to 50 kPa, more preferably 10 to 30 kPa, and even more preferably 0 to 20 kPa. When the ice-forming stress at -8°C is within the above range, an excellent snow and ice formation suppression effect can be obtained over a wide range from 0°C to -18°C. The ice-forming stress at -8°C can be measured by the method described in the examples below. The ice-forming stress at -8°C can be adjusted by the type of graft-type polymer compound (A), the type of crosslinkable polymer compound (B), the presence and type of liquid substance, the surface occupancy rate of the polymer chains of the graft-type polymer compound (A), and so on.

[0091] The difference between the ice formation stress at -18°C and the ice formation stress at -8°C for the member of this embodiment is preferably 100 kPa or less, more preferably 90 kPa or less, even more preferably 80 kPa or less, even more preferably 50 kPa or less, even more preferably 30 kPa or less, and particularly preferably 10 kPa or less. When the difference is within the above range, an excellent snow and ice formation suppression effect can be obtained over a wide range from 0°C to -18°C. For the member of this embodiment, it is preferable that the ice formation stress at -18°C is higher than the ice formation stress at -8°C. Note that the difference between the ice formation stress at -18°C and the ice formation stress at -8°C refers to the absolute value of the difference.

[0092] In this embodiment, the contact angle of the member surface with 25°C water is preferably 10° or more, more preferably 20° or more, even more preferably 45° or more, even more preferably 48° or more, and particularly preferably 48 to 80°. If the contact angle is within the above range, a better ice nucleus formation suppression effect, frost formation suppression effect, and snow accumulation ice suppression effect can be obtained. The value of the contact angle of the member surface with water is obtained by dropping 2 μL of water onto the member surface and measuring the contact angle of the water on the member surface 20 seconds after the drop has been deposited. [Examples]

[0093] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0094] <Example 1> (Preparation of graft-type polymer compound (A-1)) A main chain polymer (PolyBIEM) with an atom transfer radical polymerization (ATRP) initiation site was obtained by reversible addition-cleavage chain transfer polymerization of a 2.62 M 2-bromoisobutyryloxyethyl methacrylate (BIEM) solution in toluene under conditions of 60°C for 18 hours in the presence of 30 mM cumyl dithiobenzoate (CTA) and 6 mM azobisisobutyronitrile (AIBN). Characterization of the obtained main chain polymer (PolyBIEM) by GPC revealed a number-average molecular weight (Mn) of 1.6 × 10¹⁶ polymethyl methacrylate. 4 The molecular weight distribution (dispersion density PDI) was 1.12. GPC measurements were performed using a Shodex GPC101 (Resonac Corporation) as the GPC analyzer, with Shodex LF-804 (Resonac Corporation) and Shodex KF-06L (Resonac Corporation) as the columns, and THF as the developing solvent flowing at a flow rate of 0.8 mL / min. The oven temperature was set to 40°C.

[0095] Next, the main chain polymer (PolyBIEM) obtained above was subjected to atomic transfer radical polymerization (ATRP) using poly(ethylene glycol) methacrylate (PEGMA-OH, number average molecular weight (Mn): 500) and a copper catalyst to obtain graft-type polymer compound (A-1). In this case, the ratio of ethyl 2-bromoisobutyrate (EBIB, initiator):main chain polymer (PolyBIEM):poly(ethylene glycol) methacrylate (PEGMA-OH):CuBr:CuBr2:4,4'-dinonyl-2,2'-bipyridine (diN-bip) was 0.1:1:100:0.8:0.2:2 (molar ratio), anisole was used as the solvent in an amount four times the mass of poly(ethylene glycol) methacrylate (PEGMA-OH), and the reaction conditions were 65°C for 0.5 hours. The obtained graft-type polymer compound (A-1) was characterized by GPC, and the number-average molecular weight (Mn) in terms of polymethyl methacrylate was 9.2 × 10⁻⁶. 4 The molecular weight distribution (dispersion density PDI) was 2.0. GPC measurement was performed using a Shodex GPC101 (Resonac Corporation) as the GPC analyzer, with Shodex LF-804 (Resonac Corporation) and Shodex KF-06L (Resonac Corporation) as the columns, and by flowing DMF / LiCl as the developing solvent at a flow rate of 0.8 mL / min. The oven temperature was set to 40°C. Furthermore, the surface occupancy of the graft chains of the obtained graft polymer compound (A-1) using the above method was measured, and the surface occupancy was 0.15. The obtained graft polymer compound (A-1) was purified by dialysis in methanol solvent as a poor solvent, dried overnight under room temperature vacuum, and then stored.

[0096] (Preparation of crosslinkable polymer compound (B-1)) A crosslinkable polymer compound (B-1) was obtained by atom transfer radical polymerization (ATRP) at 65°C for 48 hours using a methacrylate containing a blocked isocyanate group having a reactive double bond (2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, trade name "Karenz MOI-BP", manufactured by Resonaq Corporation) and poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe, number average molecular weight (Mn): 500) in a ratio of blocked isocyanate compound having a reactive double bond:poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe) = 5.25:99.75 (=5:95) (molar ratio), and in addition to these, a copper catalyst. In this study, the following mixture was used: ethyl 2-bromoisobutyrate (EBIB, initiator): poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe): blocked isocyanate group-containing methacrylate (MOI-BP): CuBr:CuBr2:4,4'-dinonyl-2,2'-bipyridine (diN-bip) = 1.1:99.75:5.25:0.8:0.2:2 (molar ratio), and anisole was used as the solvent in an amount twice the mass of poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe). The resulting crosslinkable polymer compound (B-1) was characterized by GPC, and the number-average molecular weight (Mn) in terms of polymethyl methacrylate was 3.2 × 10⁻⁶. 4 The molecular weight distribution (dispersion density PDI) was 1.3. GPC measurements were performed using a Shodex GPC101 (Resonac Corporation) as the GPC analyzer, with Shodex LF-804 (Resonac Corporation) and Shodex KF-06L (Resonac Corporation) as the columns, and DMF / LiCl as the developing solvent flowing at a rate of 0.8 mL / min. The oven temperature was set to 40°C. The polymerization conversion rate of each monomer was also measured. 1¹H-NMR measurements revealed that the compound was 88.4% poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe) and 91.2% blocked isocyanate group-containing methacrylate (MOI-BP). The resulting crosslinkable polymer compound (B-1) was reprecipitated and purified using acetone / hexane = 3 / 10 (vol / vol), dried overnight under vacuum at room temperature, and then stored.

[0097] (Preparation of coating composition) A coating composition was prepared using the graft-type polymer compound (A-1) and the crosslinkable polymer compound (B-1) obtained above, in a ratio of graft-type polymer compound (A-1):crosslinkable polymer compound (B-1) = 99.9:0.1 (mass ratio). The coating composition used propylene glycol monomethyl ether acetate (PGMAc) as the solvent, and dibutyltin dilaurate as the catalyst at a ratio of 1 part by mass per 100 parts by mass of the total graft-type polymer compound (A-1) and crosslinkable polymer compound (B-1). Furthermore, the total content of graft-type polymer compound (A-1) and crosslinkable polymer compound (B-1) in the coating composition was adjusted to 2% by mass.

[0098] (Preparation of components with a coating) A silicon substrate (Si-wafer) was prepared, and 3-(2-aminoethylaminopropyl)trimethoxysilane was reacted onto the silicon substrate under basic conditions to introduce residues derived from 3-(2-aminoethylaminopropyl)trimethoxysilane into the silicon substrate. Then, the coating composition obtained above was spin-coated onto the silicon substrate containing the residues derived from 3-(2-aminoethylaminopropyl)trimethoxysilane using a spin coater. Subsequently, the crosslinking reaction between the graft-type polymer compound (A-1) and the crosslinkable polymer compound (B-1) was carried out by heating at 120°C for 1 hour, forming a coating film on the silicon substrate, and a component with the coating film was prepared. The thickness of the formed coating film was measured at room temperature using a spectroscopic elliptosomery method (MASS-105, FI-Lab, Inc.) and was found to be 105 nm. For optical constants, etc., files prepared using each test specimen prepared according to the manufacturer's specified method were used.

[0099] (Measurement of ice formation stress) Then, the component with the coating obtained above was set on a stretching stage with a cooling function for microscopes (manufactured by Japan High-Tech Co., Ltd.), and ice formation stress was measured. 60 μL of pure water was poured into the inside of an aluminum cylindrical object (inner diameter 6 mm) with silicone grease applied to its edge to wet the coating. This was then cooled to -20°C at a rate of 5°C / min and held for 30 minutes to create an ice column using the excess water that did not contribute to wetting the coating. After that, the stage's set temperature was raised at a rate of 5°C / min to the measurement temperature (-18°C or -8°C) and held for 30 minutes before the test was conducted. An L-shaped jig attached to the stretching stage was set to push the aluminum cylinder as the stretching stage moved, and the ice formation stress was calculated from the load applied to the load cell of the stretching stage when the ice column peeled off (Figure 1). The stage movement speed was set to 10 mm / min. The ice formation stress was evaluated according to the following criteria. The results are shown in Table 1. Excellent: Ice formation stress at -18°C is 100kPa or less. Good: Ice formation stress at -18°C is greater than 100kPa and less than or equal to 150kPa. Defect: Ice formation stress exceeds 150 kPa at -18°C

[0100] <Examples 2-5> In preparing the coating compositions, the ratio of graft-type polymer compound (A-1) to crosslinkable polymer compound (B-1) was changed to 99:1 (Example 2), 90:10 (Example 3), 75:25 (Example 4), and 60:40 (Example 5) respectively, except that the coating compositions were prepared in the same manner as in Example 1. Next, using the obtained coating compositions, a component with a coating film was formed in the same manner as in Example 1, and the ice formation stress was measured in the same manner as in Example 1. The measurement results are shown in Table 1. The thickness of the coating film in Examples 2 to 5 was 100 nm (Example 2), 120 nm (Example 3), 105 nm (Example 4), and 107 nm (Example 5), respectively.

[0101] <Example 6> (Preparation of graft-type polymer compound (A-2)) Atomic transfer radical polymerization (ATRP) was performed on the main chain polymer (PolyBIEM) obtained in the same manner as in Example 1, using poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe, number average molecular weight (Mn): 500) and a copper catalyst. In this process, the ratio was ethyl 2-bromoisobutyrate (EBIB, initiator):main chain polymer (PolyBIEM):poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe):CuBr:CuBr2:4,4'-dinonyl-2,2'-bipyridine (diN-bip) = 0.1:1:105:0.8:0.2:2 (molar ratio), and anisole was used as the solvent in an amount twice the mass of poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe). After stirring at 65°C for 1 hour and 30 minutes, 1¹H-NMR measurements were performed to identify the amount of remaining poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe). To this amount, 10 mol% of 3-(trimethoxysilyl)propyl methacrylate (MOPS) was added, and the mixture was stirred at 65°C for 30 minutes to obtain graft-type polymer compound (A-2). Characterization of the obtained graft-type polymer compound (A-2) by GPC revealed that the number-average molecular weight (Mn) in terms of polymethyl methacrylate was 1.4 × 10⁶. 5 The molecular weight distribution (dispersion density PDI) was 1.1. GPC measurement was performed using a Shodex GPC101 (Resonac Corporation) as the GPC analyzer, with Shodex LF-804 (Resonac Corporation) and Shodex KF-06L (Resonac Corporation) as the columns, and by flowing DMF / LiCl as the developing solvent at a flow rate of 0.8 mL / min. The oven temperature was set to 40°C. Furthermore, the surface occupancy of the graft chains of the obtained graft polymer compound (A-2) using the above method was measured, and the surface occupancy was 0.30. The obtained graft polymer compound (A-2) was reprecipitated and purified using hexane / acetone = 10 / 3 (Vol / Vol), dried overnight under room temperature vacuum, and then stored.

[0102] (Preparation of crosslinkable polymer compound (B-2)) A crosslinkable polymer compound (B-2) was obtained by free radical polymerization using poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe, number average molecular weight (Mn): 500), 3-(trimethoxysilyl)propyl methacrylate (MOPS), and 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator in the ratio poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe):3-(trimethoxysilyl)propyl methacrylate (MOPS):2,2'-azobisisobutyronitrile (AIBN) = 125:1.25:1 (molar ratio). In this process, anisole was used as the solvent in the same mass as poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe), and polymerization was carried out at 60°C for 3 hours. The obtained crosslinkable polymer compound (B-2) was characterized by GPC, and the number-average molecular weight (Mn) in terms of polymethyl methacrylate was 2,300,000, and the molecular weight distribution (dispersion degree PDI) was 3.0. GPC measurements were performed using a Shodex GPC101 (Resonac Corporation) as the GPC analyzer, with Shodex LF-804 (Resonac Corporation) and Shodex KF-06L (Resonac Corporation) as the columns, and DMF / LiCl as the developing solvent flowing at a flow rate of 0.8 mL / min. The oven temperature was set to 40°C. The obtained crosslinkable polymer compound (B-2) was reprecipitated and purified using hexane / acetone = 10 / 3 (vol / vol), dried overnight under room temperature vacuum, and then stored. 1 1H-NMR measurement revealed that the amount of MOPS introduced was approximately 1 mol%.

[0103] (Preparation of coating composition, preparation of components with a coating film) A coating composition was prepared using the graft-type polymer compound (A-2) and the crosslinkable polymer compound (B-2) obtained above, in a ratio of graft-type polymer compound (A-2) to crosslinkable polymer compound (B-2) = 92:8 (mass ratio). The coating composition used propylene glycol monomethyl ether acetate (PGMAc) as the solvent, and 0.1N dilute hydrochloric acid as a catalyst at a ratio of 1 part by mass per 100 parts by mass of the total graft-type polymer compound (A-2) and crosslinkable polymer compound (B-2). The total content ratio of graft-type polymer compound (A-2) and crosslinkable polymer compound (B-2) in the coating composition was adjusted to 2% by mass. Next, a component with a coating film was formed using the obtained coating composition in the same manner as in Example 1, and the ice formation stress was measured in the same manner as in Example 1. The measurement results are shown in Table 1. The thickness of the coating film in Example 6 was 98 nm.

[0104] <Comparative Example 1> A coating composition was prepared using the graft-type polymer compound (A-2) obtained in Example 6. The coating composition used propylene glycol monomethyl ether acetate (PGMAc) as the solvent, and 0.1N dilute hydrochloric acid as a catalyst at a ratio of 1 part by mass per 100 parts by mass of the graft-type polymer compound (A-2). The content of the graft-type polymer compound (A-2) in the coating composition was adjusted to 2% by mass. Next, a component with a coating film was formed using the obtained coating composition in the same manner as in Example 1, and the ice formation stress at -18°C was measured in the same manner as in Example 1. Since the ice formation stress measurement result at -18°C was greater than 150 kPa, the ice formation stress measurement at -8°C was not performed. The measurement results are shown in Table 1. The thickness of the coating film in Comparative Example 1 was 100 nm.

[0105] <Comparative Example 2> A coating composition was prepared in the same manner as in Example 6, except that tetraethoxysilane was used instead of the crosslinkable polymer compound (B-2). Next, a member with a coating film was formed using the obtained coating composition in the same manner as in Example 1, and the ice formation stress was measured in the same manner as in Comparative Example 1. The measurement results are shown in Table 1. The thickness of the coating film in Comparative Example 2 was 100 nm.

[0106] <Comparative Example 3> (Preparation of graft-type polymer compound (A-3)) Graft-type polymer compound (A-3) was obtained by atom transfer radical polymerization (ATRP) using poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe, number average molecular weight (Mn): 500) and a copper catalyst on the main chain polymer (PolyBIEM) obtained in the same manner as in Example 1. In this case, the ratio of ethyl 2-bromoisobutyrate (EBIB, initiator):main chain polymer (PolyBIEM):poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe):CuBr:CuBr2:4,4'-dinonyl-2,2'-bipyridine (diN-bip) was 0.1:1:105:0.8:0.2:2 (molar ratio), anisole was used as the solvent in twice the mass of poly(ethylene glycol) methyl ether methacrylate (PEGMA-OMe), and the reaction conditions were 65°C for 2 hours. The obtained graft-type polymer compound (A-3) was characterized by GPC, and the number-average molecular weight (Mn) in terms of polymethyl methacrylate was 1.3 × 10⁻⁶. 5The molecular weight distribution (dispersion density PDI) was 1.1. GPC measurement was performed using a Shodex GPC101 (Resonac Corporation) as the GPC analyzer, with Shodex LF-804 (Resonac Corporation) and Shodex KF-06L (Resonac Corporation) as the columns, and by flowing DMF / LiCl as the developing solvent at a flow rate of 0.8 mL / min. The oven temperature was set to 40°C. Furthermore, the surface occupancy of the graft chains of the obtained graft polymer compound (A-3) using the above method was measured, and the surface occupancy was 0.30. The obtained graft polymer compound (A-3) was reprecipitated and purified using hexane / acetone = 10 / 3 (Vol / Vol), dried overnight under room temperature vacuum, and then stored.

[0107] (Preparation of coating composition, preparation of components with a coating film) A coating composition was prepared using the graft-type polymer compound (A-3) obtained above. The coating composition used anisole as the solvent and tetrakis(dimethylamino)ethylene (a catalyst for crosslinking bromine atoms derived from 2-bromoisobutyryloxyethyl methacrylate (BIEM) contained in the graft-type polymer compound (A-3)) as a catalyst, at a ratio of 1 part by mass per 100 parts by mass of the graft-type polymer compound (A-3). The content of the graft-type polymer compound (A-3) in the coating composition was prepared to be 2% by mass. A silicon substrate (Si-wafer) was prepared, and 3-(trimethoxysilyl)propyl-2-bromo-2-methylpropanoate was reacted on the silicon substrate under basic conditions, thereby introducing residues derived from 3-(trimethoxysilyl)propyl-2-bromo-2-methylpropanoate into the silicon substrate. Then, the coating composition obtained above was spin-coated onto a silicon substrate into which residues derived from 3-(trimethoxysilyl)propyl-2-bromo-2-methylpropanoate were introduced, using a spin coater. Subsequently, the mixture was heated at 120°C for 1 hour to promote the crosslinking reaction between graft-type polymer compound (A-3) molecules, forming a coating film on the silicon substrate and preparing a component with the coating film. Next, using the obtained coating composition, a component with the coating film was formed in the same manner as in Example 1, and the ice formation stress was measured in the same manner as in Comparative Example 1. The measurement results are shown in Table 1. The thickness of the coating film in Comparative Example 3 was 105 nm.

[0108] <Comparative Example 4> The coating composition was prepared in the same manner as in Example 1, except that the ratio of graft-type polymer compound (A-1) to crosslinkable polymer compound (B-1) was changed to 50:50 in terms of the mass ratio of "graft-type polymer compound (A-1): crosslinkable polymer compound (B-1)". Next, a component with a coating film was formed using the obtained coating composition in the same manner as in Example 1, and the ice formation stress was measured in the same manner as in Comparative Example 1. The measurement results are shown in Table 1. The thickness of the coating film in Comparative Example 4 was 93 nm.

[0109] <Comparative Example 5> A coating composition was prepared in the same manner as in Example 1, except that Trixene(R) Aqua BI 7982 (manufactured by Lanxess AG, low molecular weight isocyanate compound, molecular weight: 764) was used instead of the crosslinkable polymer compound (B-1), and the ratio of use was set to 90:10 in mass ratio of "graft-type polymer compound (A-1):Trixene(R) Aqua BI 7982 (low molecular weight isocyanate compound)". Next, a component with a coating film was formed using the obtained coating composition in the same manner as in Example 1, and the ice formation stress was measured in the same manner as in Comparative Example 1. The measurement results are shown in Table 1. The thickness of the coating film in Comparative Example 5 was 93 nm.

[0110] <Examples 7-11> (Preparation of graft-type polymer compound (A-4)) Graft polymer compound (A-4) was obtained by atom transfer radical polymerization (ATRP) of graft polymer compound (A-3), which was obtained in the same manner as in Comparative Example 3, using a methacrylate containing a blocked isocyanate group having a reactive double bond (2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, trade name "Karenz MOI-BP", manufactured by Resonaq Corporation) and a copper catalyst. In this case, the reaction starting site of graft polymer compound (A-3) was set to: blocked isocyanate group-containing methacrylate:CuBr:CuBr2:4,4'-dinonyl-2,2'-bipyridine (diN-bip) = 1:500:0.8:0.2:2 (molar ratio), anisole was used as the solvent in the same mass as the blocked isocyanate group-containing methacrylate, and the reaction conditions were 60°C for 15 minutes. Characterization of the obtained grafted polymer compound (A-4) by 1H-NMR confirmed that an average of 1.3-mer blocked isocyanate group-containing methacrylate was introduced at each graft end. Furthermore, based on the calculation method, the surface occupancy of the graft chains of the obtained grafted polymer compound (A-4) can be considered equivalent to that of grafted polymer compound (A-3). The obtained grafted polymer compound (A-4) was washed with a 2 wt% EDTA (ethylenediaminetetraacetic acid) aqueous solution to remove the copper catalyst. Subsequently, it was reprecipitated and purified using hexane / acetone = 10 / 3 (Vol / Vol), dried overnight under room temperature vacuum, and then stored.

[0111] (Preparation of coating composition, preparation of components with a coating film) The coating compositions of Examples 7 to 11 were prepared by mixing the graft-type polymer compound (A-4) obtained above with cellulose nanofiber (manufactured by Nippon Paper Industries, trade name "Selenvia TC-01A", Mn=17,600, Mw=163,600) as the crosslinkable polymer compound (B-3), so as shown in Table 2. Pure water was used as the solvent for the coating composition, and DABCO (1,4-Diazabicyclo[2.2.2]octane) was used as a catalyst at a ratio of 1 part by mass per 100 parts by mass of the total graft-type polymer compound (A-4) and crosslinkable polymer compound (B-3) (Selenvia TC-01A). Furthermore, the total content ratio of the graft-type polymer compound (A-4) and the crosslinkable polymer compound (B-3) (Selenvia TC-01A) in the coating composition was prepared to be 1.5% by mass.

[0112] (Preparation of components with a coating) A silicon substrate (Si-wafer) was prepared, and 3-(2-aminoethylaminopropyl)trimethoxysilane was reacted onto the silicon substrate under basic conditions to introduce residues derived from 3-(2-aminoethylaminopropyl)trimethoxysilane into the silicon substrate. Then, the coating compositions of Examples 7 to 11 were spin-coated onto the silicon substrate containing the residues derived from 3-(2-aminoethylaminopropyl)trimethoxysilane using a spin coater. Subsequently, the mixture was heated at 70°C for 18 hours under reduced pressure to allow the crosslinking reaction between the graft-type polymer compound (A-4) and the crosslinkable polymer compound (Selenvia TC-01A) to proceed, forming a coating film on the silicon substrate and preparing a component with the coating film. The thickness of the formed coating film was measured at room temperature using a spectroscopic elliptosomery method (MASS-105, FI-Lab), and was found to be 220 nm. For optical constants, etc., files prepared using each test specimen prepared according to the manufacturer's specified method were used.

[0113] [Table 1]

[0114] [Table 2]

[0115] As shown in Table 1, a component having a coating film formed using a coating composition that includes a graft-type polymer compound (A) containing a structural unit represented by general formula (1) and having a crosslinkable functional group (a), and a crosslinkable polymer compound (B) having two or more reactive functional groups (b) different from the crosslinkable functional group (a), wherein the content of the crosslinkable polymer compound (B) in the total 100% by mass of the graft-type polymer compound (A) and the crosslinkable polymer compound (B) is 0.1% by mass or more and less than 50% by mass, exhibits low ice formation stress at -18°C and can effectively suppress ice nucleation, frost formation, and snow and ice accumulation (Examples 1-11). When the crosslinkable polymer compound (B) is a copolymer of a monomer having a reactive functional group (b) and a monomer copolymerizable with such monomer, and the crosslinkable functional group (a) and the reactive functional group (b) are different groups from each other, the ice formation stress at -18°C was extremely low, and ice nucleation, frost formation, and snow accumulation were very effectively suppressed (Examples 1-5). Furthermore, when the crosslinkable polymer compound (B) is a copolymer of a monomer having a reactive functional group (b) and a monomer copolymerizable with such monomer, and when a graft-type polymer compound (A) and the crosslinkable polymer compound (B) with the same crosslinkable functional group are used, the ice formation stress at -18°C was low, and ice nucleation, frost formation, and snow accumulation were effectively suppressed (Example 6). Moreover, when the crosslinkable polymer compound (B) is cellulose nanofiber, the ice formation stress at -18°C was low, and ice nucleation, frost formation, and snow accumulation were effectively suppressed (Examples 7-11).

[0116] On the other hand, in cases where the crosslinkable polymer compound (B) was not present (Comparative Examples 1 and 3), when a substance having a reactive functional group (b) but not being a polymer compound was used (Comparative Examples 2 and 5), and when the proportion of the crosslinkable polymer compound (B) was too high (Comparative Example 4), the ice formation stress at -18°C was high in all cases, and the expected effect of suppressing ice nucleation, frost formation, and snow and ice accumulation could not be observed.

Claims

1. A component for suppressing ice nucleation, frost formation, or snow and ice accumulation, having a coating film obtained by applying a coating composition containing a solvent and a polymer, The polymer comprises a graft-type polymer compound (A) having a structural unit represented by the following general formula (1) and a crosslinkable functional group (a), and a crosslinkable polymer compound (B) having two or more reactive functional groups (b) that crosslink with the crosslinkable functional group (a). The content of the crosslinkable polymer compound (B) in the total of 100% by mass of the graft-type polymer compound (A) and the crosslinkable polymer compound (B) is 0.1% by mass or more and less than 50% by mass. A component whose ice formation stress at -18°C is 150 kPa or less. 【Transformation 7】 (In the above general formula (1), R １ represents a hydrogen atom or a methyl group, X represents O or NH, and R represents a hydrogen atom or a methyl group. ２ R represents any organic group. ３ and R ４ Each of these independently represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group, and R ３ and R ４ The carbon atoms to which the molecule is bonded are tertiary or quaternary carbon atoms, n represents an arbitrary number of repeats, and Polymer represents a graft chain containing constituent units derived from at least one graft monomer selected from the group consisting of (meth)acrylic acid monomers, (meth)acrylamide monomers, aromatic vinyl monomers, and (meth)acrylonitrile.

2. The member according to claim 1, wherein the difference between the ice formation stress at -18°C and the ice formation stress at -8°C is 100 kPa or less.

3. The member according to claim 1 or 2, wherein the crosslinkable functional group (a) and the reactive functional group (b) are different groups from each other.

4. The member according to claim 1 or 2, wherein the surface occupancy rate of the graft chains of the graft-type polymer compound (A) is 0.05 or more and less than 0.

75.

5. The member according to claim 1 or 2, wherein the number average molecular weight (Mn) of the crosslinkable polymer compound (B) is 5,000 to 3,000,000.

6. The member according to claim 1 or 2, wherein the crosslinkable functional group (a) and the reactive functional group (b) are, each, at least one functional group selected from the group consisting of a hydroxyl group, an isocyanate group, a blocked isocyanate group, and an alkoxysilyl group.

7. The member according to claim 1 or 2, wherein the number average molecular weight (Mn) of the graft-type polymer compound (A) is 10,000 to 1,000,000.

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