Member for suppressing ice nucleus formation or suppressing ice accretion

Abstract

To provide a member that is capable of suppressing ice nucleus formation and ice accretion.SOLUTION: This member for suppressing ice nucleus formation or for suppressing ice accretion is characterized by comprising a layer which includes a brush-like polymer chain aggregate constituted by a plurality of polymer chains fixed to a base material, wherein the layer including the polymer chain aggregate holds a liquid substance, and ice accretion stress at -18°C is not more than 150 kPa.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ice nucleation or ice accretion suppression component. [Background technology]

[0002] In heat exchangers used in air conditioners and refrigerators, rapid cooling of air can cause water droplets to adhere to the surface of the cooling element in the heat exchanger, or frost to form, reducing the heat exchange efficiency. In particular, frost forms through the formation and growth of ice nuclei and ice adhesion on the surface of the cooling element. As a method for suppressing the formation of frost, a method of forming a resin film on the surface of a member, as described in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-158247 Summary of the Invention [Problem to be solved by the invention]

[0004] The method described in Patent Document 1 can control the shape of water droplets that adhere to the surface of a component and thereby delay the growth of frost, but it cannot sufficiently suppress ice nucleation or icing on the surface of the component, and further improvements were needed.

[0005] Therefore, an object of the present invention is to provide a member that can suppress ice nucleation and icing. [Means for solving the problem]

[0006] That is, the present invention is as follows. [1] a layer including a brush-like polymer chain assembly composed of a plurality of polymer chains fixed to a substrate; the layer containing the polymer chain assembly holds a liquid substance, A material for ice nucleation prevention or ice accretion prevention that has an ice accretion stress of 150 kPa or less at -18°C. [2] The member according to [1], wherein the difference between the icing stress at -18°C and the icing stress at -8°C is 100 kPa or less. [3] The member according to [1] or [2], wherein the polymer chain assembly does not swell in water and the liquid substance is immiscible with water. [4] the substrate is a carrier made of a material different from the polymer chain assembly, The member according to [1] or [2], wherein the surface occupancy of the polymer chains on the surface of the substrate is 0.08 to 0.65. [5] the member has a bottle-brush structure in which the plurality of polymer chains are bonded as side chains to a polymer chain that is the base material, The member according to [1] or [2], wherein the surface occupancy of the side chains is 0.08 to 0.65. [Effects of the Invention]

[0007] The member of the present invention has the above-described configuration, and therefore can suppress ice nucleation and icing. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating a test method for icing stress. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The present invention is not limited to the following description, and various modifications can be made within the scope of the gist of the present invention.

[0010] [Component] The component of this embodiment is a component for inhibiting ice nucleation or icing, having a layer containing brush-like polymer chain assemblies composed of a plurality of polymer chains fixed to a substrate, the layer containing the polymer chain assemblies retaining a liquid substance, and having an icing stress of 150 kPa or less at -18°C. The member may be a member consisting of only a substrate and the layer containing the polymer chain assembly, or may further include other layers or materials. The layer containing the polymer chain assembly may be a layer consisting of only the polymer chain assembly and a liquid substance, or may further contain other substances.

[0011] The member of this embodiment has excellent anti-icing and anti-ice nucleation effects. While the exact reasons for these effects are unclear, it is presumed to be due to the following: In the member of this embodiment, the liquid substance is held by the polymer chain assemblies, forming a stable liquid layer that is less susceptible to irreversible liquid leakage within the layer containing the polymer chain assemblies. Furthermore, it is presumed that the mobility of the liquid substance held by the polymer chain assemblies is appropriately controlled by the polymer chain assemblies, making it more likely to create a supercooled or antifreeze state. Due to the presence of such a stable liquid layer, the member of this embodiment is presumed to have an interface with high mobility against ice, snow, frost, and the like. Furthermore, it is presumed that the presence of such a stable liquid layer allows thermal movement of water without solidification even below the freezing point, further lowering the freezing temperature of water on the member surface. Furthermore, the component of this embodiment is unlikely to freeze water on its surface, and is unlikely to form ice, snow, frost, etc. on its surface. Furthermore, since it has an interface with high mobility against ice, snow, frost, etc., even if ice, snow, frost, etc. forms on the component surface, these have excellent sliding properties, and it is therefore presumed that the component has an excellent anti-icing effect. Furthermore, the component of this embodiment can further lower the freezing temperature of water inside or on the surface of the component, thereby lowering the temperature at which ice nuclei form, and is therefore presumed to have an excellent effect of suppressing ice nucleation.

[0012] The polymer chain aggregate used in this embodiment is an aggregate of multiple polymer chains that has a brush-like shape as a whole, and is completely different from an organic film formed by simply applying a polymer solution. In this specification, the term "brush-like" may refer to a structure in which there are multiple (e.g., two or more) polymer chains, at least one end of which is fixed to the surface of a substrate or a layer on the substrate, and which extend in a direction away from the substrate. When both ends of the polymer chain are fixed to the substrate, the structure may be U-shaped.

[0013] Whether the layer containing the polymer chain aggregate retains the liquid substance can be confirmed by differential scanning calorimetry. If this cannot be confirmed by differential scanning calorimetry, it can be confirmed by an indentation test.

[0014] In the member of this embodiment, the liquid substance is preferably retained in the layer containing the polymer chain assembly and 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). The liquid substance is preferably water. Whether the liquid substance is in a liquid state can be confirmed by differential scanning calorimetry. If confirmation by differential scanning calorimetry is not possible, it can be confirmed by an indentation hardness test. The member of this embodiment can reduce the difference between the icing stress at −8°C and that at −18°C, and from the viewpoint of excellent ice nucleation and icing suppression effects around −18°C, the proportion of the substance confirmed to be in a liquid state by the above-mentioned method is preferably 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, per 100 parts by mass of polymer chains contained in the layer containing the polymer chain assembly at −18°C. This proportion can be adjusted by, for example, combining the polymer chains with the liquid substance. This proportion can also be measured using an atomic force microscope or ellipsometry. The member of this embodiment preferably has a layer containing brush-like polymer chain assemblies composed of a plurality of polymer chains fixed to a substrate at −18°C, and the layer containing the polymer chain assemblies preferably holds a liquid substance.

[0015] In the member of this embodiment, the film thickness of the layer containing the polymer chain assembly is preferably 50 nm or more, more preferably 100 nm or more, even more preferably 350 nm or more, still more preferably 500 nm or more, and particularly preferably 1000 nm or more, because this makes it easier to obtain a better anti-icing effect and anti-ice nucleation effect. There is no particular upper limit, but it can be, for example, 100 μm or less, or 50 μm or less. The thickness of the layer containing the polymer chain assembly can be measured by ellipsometry etc. The thickness may be a value measured at -18°C.

[0016] The components of this embodiment will be described in detail below.

[0017] [Polymer chain assembly] The polymer chain assembly in this embodiment is composed of multiple polymer chains and has a brush-like shape as a whole. In this specification, "polymer chain" refers to a molecule or a portion of a molecule having a structure in which multiple structural units are linked in a chain. The multiple polymer chains that make up the polymer chain assembly may be the same or different from each other. Furthermore, the polymer chain may have a structure in which multiple identical or different structural units are linked in a chain, and may have a side chain or a branched structure, and a crosslinked structure may be formed between the polymer chains or between the polymer chain and the substrate.

[0018] (polymer chain) The polymer chains may be polymer chains that have affinity for the liquid substance to be held in the layer containing the polymer chain aggregate, or may be polymer chains that do not have affinity. For example, when a layer containing a polymer chain assembly is to retain water or a hydrophilic liquid substance, the polymer chains constituting the polymer chain assembly are preferably hydrophilic polymer chains. The hydrophilic polymer chains may be synthesized using a hydrophilic monomer, or may be synthesized by synthesizing a polymer using a hydrophobic monomer and then introducing a hydrophilic group into the polymer. In this specification, a polymer chain that is highly compatible with water may be referred to as a "compatible polymer chain," and a polymer chain that is poorly compatible with water may be referred to as a "non-compatible polymer chain." Note that a polymer chain that is highly compatible with water refers to a polymer chain that has a swelling index of 1.5 or more (preferably 2.0 or more, more preferably 2.5 or more), as measured and calculated by a film thickness measurement method using an atomic force microscope, and a polymer chain that is poorly compatible with water refers to a polymer chain that has a swelling index of less than 1.5 (preferably 1.3 or less, more preferably 1.1 or less, even more preferably 1.08 or less, and particularly preferably 1.05 or less). The swelling degree mentioned above refers to a value measured by the following method. The test specimen for which the film thickness is to be measured is scratched with the tip of tweezers or the like, and the height of the step (i.e., dry film thickness) is estimated at the boundary between the part where the substrate base is exposed and the part where the film is present using the atomic force microscope colloid probe method (contact mode). Next, the same test specimen is immersed overnight in the corresponding liquid substance, and the height of the step (i.e., swollen film thickness) is estimated at the same location in the liquid using the atomic force microscope colloid probe method (contact mode). The swelling degree is then calculated from the swollen film thickness / dry film thickness ratio.

[0019] The polymer chain may be a homopolymer formed by polymerizing one type of monomer, or a copolymer formed by polymerizing two or more types of monomers. Examples of the copolymer include random copolymers, block copolymers, and gradient copolymers.

[0020] The monomer used to generate the polymer chain is preferably one that can be polymerized to form a graft chain and bonded to the substrate. Examples of such a monomer include a monomer having at least one addition-polymerizable double bond, and a monofunctional monomer having one addition-polymerizable double bond is preferred. Examples of the monofunctional monomer having one addition-polymerizable double bond include (meth)acrylic acid-based monomers and styrene-based monomers. The polymer chain may also be a polymer obtained by reacting polymers having reactive groups with each other. Examples of reactive groups include hydroxyl groups and isocyanate groups. Examples of polymers having reactive groups include polymers of polyethylene glycol and dimethylsiloxane, and specific examples include Silaplane FM-0421 (reactive silicone) (manufactured by Shin-Etsu Chemical Co., Ltd.). From the viewpoint of being able to reduce the difference between the icing stress at -8°C and that at -18°C and being particularly effective in suppressing ice nucleation and icing at temperatures around -18°C, methoxypoly(ethylene glycol) methacrylate or a mixture of dodecyl methacrylate and tridecyl methacrylate is preferred, and from the viewpoint of suppressing snow accumulation outdoors, a mixture of dodecyl methacrylate and tridecyl methacrylate is particularly preferred.

[0021] Examples of (meth)acrylic acid monomers include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, and methyl (meth)acrylate. (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate, 3-ethyl-3 -(Meth)acryloyloxymethyloxetane, 2-(meth)acryloyloxyethyl isocyanate, (meth)acrylate-2-aminoethyl, 2-(2-bromopropionyloxy)ethyl (meth)acrylate, 2-(2-bromoisobutyryloxy)ethyl (meth)acrylate, 1-(meth)acryloxy-2-phenyl-2-(2,2,6,6-tetramethyl-1-piperidinyloxy)ethane, 1-(4-((4-(meth)acryloxy)ethoxyethyl)phenylethoxy)piperidine, γ-(methacryloyloxy) Dipropyl)trimethoxysilane, 3-(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptaisobutyl-pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)propyl (meth)acrylate, 3-(3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1. 13,9.15,15.17,13]octasiloxan-1-yl)propyl (meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl]propyl (meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl]propyl (meth)acrylate Heptaisobutylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl]propyl (meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl]propyl yl(meth)acrylate, 3-[(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl]propyl(meth)acrylate, 3-[(3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.13,9.15,15.[17,13]octasiloxane-1-yloxy)dimethylsilyl]propyl (meth)acrylate, ethylene oxide adduct of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, trifluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, and the like.

[0022] Styrenic monomers include styrene, vinyltoluene, α-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, m-chloromethylstyrene, o-aminostyrene, p-styrene chlorosulfonic acid, styrenesulfonic acid and its salts, vinylphenylmethyldithiocarbamate, 2-(2-bromopropionyloxy)styrene, 2-(2-bromoisobutyryloxy)styrene, 1-(2-((4-vinylphenyl)methoxy)-1-phenylethoxy)-2,2,6,6-tetramethylpiperidine, 1-(4-vinylphenyl)- 3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15 -Heptacyclopentylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane, 1-(4-vinylphenyl)-3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane, 3-(3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane-1-yl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.13, 9.15,15.17,13]octasiloxan-1-yl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptaisooctylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)ethylstyrene, 3-(3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yl)ethylstyrene, 3-((3,5,7,9,11,13,15-heptaethylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl)ethylstyrene, 3-((3,5,7,9,11,13,15-heptaisobutylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl)ethylstyrene, 3-((3,5,7,9,11,13,15-heptaisooctylpentacyclo[9 Examples include 3-((3,5,7,9,11,13,15-heptacyclopentylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl)ethylstyrene, 3-((3,5,7,9,11,13,15-heptaphenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxan-1-yloxy)dimethylsilyl)ethylstyrene, and the like.

[0023] In addition, examples of monofunctional monomers having one addition-polymerizable double bond per molecule include fluorine-containing vinyl monomers (perfluoroethylene, perfluoropropylene, vinylidene fluoride, etc.), silicon-containing vinyl monomers (vinyltrimethoxysilane, vinyltriethoxysilane, etc.), maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid, fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid, maleimide monomers (maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide, etc.), and nitrile group-containing monomers. Monomers (acrylonitrile, methacrylonitrile, etc.), amide group-containing monomers (acrylamide, methacrylamide, etc.), vinyl ester monomers (vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, vinyl cinnamate, etc.), olefins (ethylene, propylene, etc.), conjugated diene monomers (butadiene, isoprene, etc.), vinyl halides (vinyl chloride, etc.), vinylidene halides (vinylidene chloride, etc.), allyl halides (allyl chloride, etc.), allyl alcohol, vinylpyrrolidone, vinylpyridine, N-vinylcarbazole, methyl vinyl ketone, vinyl isocyanate, macromonomers whose main chains are derived from styrene, (meth)acrylic acid esters, siloxanes, etc., can also be used.

[0024] It is also preferable to use an ionic liquid type monomer for generating the polymer chain. The ionic liquid type monomer is not particularly limited, but examples thereof include compounds represented by the following formula (1).

[0025] [ka]

[0026] In formula (1), m represents an integer of 1 to 10, and n represents an integer of 1 to 5. 1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R2 , R 3 and R 4 each independently represents an alkyl group having 1 to 5 carbon atoms, provided that R 2 , R 3 and R 4 The alkyl group in the formula (I) may have a carbon atom or a hydrogen atom substituted with one or more heteroatoms selected from oxygen, sulfur, and fluorine atoms, and R 2 , R 3 and R 4 may be linked together to form a cyclic structure.

[0027] Y represents a monovalent anion. Examples of the monovalent anion represented by Y include BF4 - , PF6 - , AsF6 - , SbF6 - , AlCl4 - , NbF6 - , HSO4 - , ClO4 - , CH3SO3 - , CF3SO3 - , CF3CO2 - , (CF3SO2)2N - , Cl - , Br - , I - Considering the stability of the anion, BF4 - , PF6 - , (CF3SO2)2N - , CF3SO3 - , or CF3CO2 - It is preferable that:

[0028] The ionic liquid type monomer is preferably a compound represented by any one of the following formulas (2) to (9) among the compounds represented by formula (1). [ka]

[0029] In formulas (2) to (9), m, n, and R 1 , R 2, Y is m, n, R in Eq. (1) 1 , R 2 , Y. Me represents a methyl group, and Et represents an ethyl group.

[0030] It is preferable to use a hydrophilic monomer for producing the hydrophilic polymer chain, that is, the hydrophilic polymer chain preferably contains a repeating unit derived from the hydrophilic monomer. Preferred hydrophilic monomers include hydroxy-substituted alkyl (meth)acrylates (e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, polyethoxyethyl (meth)acrylate, polyethoxypropyl (meth)acrylate, etc.), poly(alkylene glycol) mono(meth)acrylates (e.g., poly(ethylene glycol) monomethacrylate, etc.), alkoxy poly(alkylene glycol) (meth)acrylates (e.g., methoxy poly(ethylene glycol) methacrylate, etc.), and phenoxy poly(alkylene glycol) (meth)acrylates (e.g., phenoxy poly(ethylene glycol) methacrylate, etc.), with polyalkoxy poly(alkylene glycol) (meth)acrylates being more preferred. Furthermore, hydrophilic monomers that can be used include (meth)acrylamide, N-alkyl(meth)acrylamides (e.g., N-methylacrylamide, N,N-dimethylacrylamide, N-methylmethacrylamide, etc.), 2-glucosyloxyethyl(meth)acrylate, acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid, methacrylamide, N-vinylpyrrolidone, N,N-dimethylaminoethyl(meth)acrylate, and quaternary ammonium salts thereof.

[0031] To generate hydrophilic polymer chains, it is also preferable to use a monomer having a side chain with a group that can be easily converted to a carboxyl group or a salt of a carboxyl group. Hydrophilicity can be imparted by converting the side chain group of the generated polymer chain to a carboxyl group or a salt of a carboxyl group. Examples of monomers having a side chain with a group that can be easily converted to a carboxyl group or a salt of a carboxyl group include tert-butyl (meth)acrylate.

[0032] In the member of this embodiment, when the liquid substance is a hydrophilic substance (e.g., water), the polymer chain is preferably a compatible polymer chain, from the viewpoint of reducing the difference between the ice formation stress at −8°C and that at −18°C and providing excellent ice nucleation and icing suppression effects at around −18°C. The compatible polymer chain preferably contains a structural unit derived from at least one compatible monomer selected from the group consisting of nonionic monomers such as poly(ethylene glycol) monomethacrylate; anionic monomers such as potassium 3-sulfopropyl methacrylate; cationic monomers such as methacryloyloxyethyltrimethylammonium chloride; and betaine monomers such as (3-[(3-acrylamidopropyl)dimethylammonio]propane-1-sulfonic acid). Of these, betaine monomers are preferred from the viewpoint of particularly excellent ice nucleation and icing suppression effects at around −18°C. The compatible monomers may be used alone or in combination. The compatible polymer chain refers to a polymer chain in which the mass ratio of the structural unit derived from the compatible monomer relative to 100 parts by mass of the compatible polymer chain is more than 50 parts by mass (preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and particularly preferably 100 parts by mass). The compatible polymer chain is such that the mass ratio of the structural unit derived from the betaine monomer relative to 100 parts by mass of the compatible polymer chain is preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and particularly preferably 100 parts by mass. The compatible monomer is a monomer whose swelling index when made into a homopolymer is 1.1 or more, and the incompatible monomer is a monomer whose swelling index when made into a homopolymer is less than 1.1.

[0033] In the member of this embodiment, when the liquid substance is a substance immiscible with water (e.g., an ionic liquid such as MEMP-TFSI or a hydrocarbon-based oil such as poly-αolefin), the polymer chain is preferably an immiscible polymer chain, from the viewpoint of reducing the difference between the ice formation stress at −8°C and that at −18°C and providing excellent ice nucleation and ice formation suppression effects around −18°C. Preferably, the polymer chain contains structural units derived from an immiscible monomer, such as an alkyl methacrylate having an alkyl group of 1 to 20 carbon atoms (preferably 1 to 15 carbon atoms), such as methyl methacrylate, dodecyl methacrylate, or tridecyl methacrylate, or a methacrylate-terminated silicone macromonomer. In particular, from the viewpoint of providing particularly excellent ice nucleation and ice formation suppression effects around −18°C, it is preferable for the polymer chain to contain structural units derived from a methacrylate-terminated silicone macromonomer (more preferably, consisting solely of structural units derived from a methacrylate-terminated silicone macromonomer). The immiscible monomers may be used singly or in combination. The incompatible polymer chain refers to a polymer chain in which the mass ratio of the structural unit derived from the incompatible monomer relative to 100 parts by mass of the incompatible polymer chain is more than 50 parts by mass (preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and particularly preferably 100 parts by mass).

[0034] The monomers used to form these polymer chains may be used alone or in combination of two or more.

[0035] The polymer chain assembly may have crosslinked structures formed between the polymer chains or between the polymer chain and the substrate. This allows the elastic modulus of the polymer chain assembly to be controlled. The crosslinked structures formed between the polymer chains may be either physical or chemical. The crosslinked structures may be formed simultaneously with the polymerization reaction to generate the polymer chains or after the polymer chains are generated. The formation of crosslinked structures simultaneously with the polymerization reaction to generate the polymer chains can be achieved by adding an appropriate amount of a bifunctional monomer, such as a divinyl monomer such as ethylene glycol dimethacrylate, to the polymerization reaction solution in addition to the monofunctional monomer used to generate the polymer chains. Furthermore, the formation of crosslinked structures between the generated polymer chains or between the polymer chain and the substrate can be achieved by introducing a crosslinking group into the polymer chain using a monomer having a crosslinking group, and then reacting the crosslinking group with a reactive group on another polymer chain or with a reactive group on the substrate. Examples of crosslinking groups include azide groups, halogen groups (preferably bromo groups), alkoxysilyl groups, isocyanate groups, vinyl groups, and thiol groups. Furthermore, when polymer chains are produced by living radical polymerization, reactive groups remaining at the ends of graft chains can also be used as crosslinking groups.

[0036] It is preferable that the polymer chain assembly does not swell in water. When the polymer chain assembly does not swell in water, it is preferable that the liquid substance is not miscible with water. When the liquid substance is not miscible with water, it is not necessary to suck out the liquid substance when ice forms, and ice formation can be suppressed more efficiently. Among these, from the viewpoint of improving snow accretion suppression outdoors, a member with a polymer brush structure having a layer containing a polymer chain assembly that does not swell in water (preferably an assembly of incompatible polymer chains that do not swell in water, more preferably an assembly of polymer chains that do not swell in water and are composed of structural units derived from alkyl methacrylate having an alkyl group of 1 to 20 carbon atoms (even more preferably 1 to 15 carbon atoms) is preferred. Furthermore, from the viewpoint of further improving snow accretion suppression, it is preferred to use a hydrocarbon oil (preferably poly-α-olefin) as the liquid substance. "Not swelling in water" means that the degree of swelling in water measured and calculated using an atomic force microscope is 1.1 or less (preferably 1.08 or less, more preferably 1.05 or less).

[0037] In the member of this embodiment, the polymer chains that make up the polymer chain assembly are fixed to a substrate. The substrate may be a carrier made of a substance different from that of the polymer chain assembly, or may be a linear or branched polymer chain that is the same as or different from that of the polymer chain assembly. In this specification, the polymer chain that serves as the substrate may be referred to as a "trunk polymer." When the substrate is a carrier, the polymer chain aggregate forms a "polymer brush." ​​The carrier has a large surface area (e.g., 100 mm ) such as a flat, spherical, or porous shape. 2 The substrate may have a surface area of ​​at least 1000 nm. Furthermore, when the substrate is a trunk polymer, the trunk polymer as the main chain and the polymer chains (side chains) bonded to the main chain as a whole constitute a “bottle brush structure.” When the substrate is a trunk polymer, the member of this embodiment includes the bottle brush structure adhered to the above-mentioned carrier. Furthermore, when the polymer chains constituting the polymer chain assembly are immobilized on a support made of a material different from the polymer chain assembly, for example, when the polymer chain assembly constitutes a "polymer brush," only one end of the polymer chain may be immobilized on a substrate (support), or both ends of the polymer chain may be immobilized on a substrate (support). When both ends of the polymer chain are immobilized on a substrate (support), the polymer chain forms a loop structure, and such a polymer chain assembly constitutes a polymer brush with a loop structure. The brush-like polymer forming a loop structure may be a bottle brush. Here, "fixing" refers to direct chemical bonding between a polymer chain and a compound constituting the substrate or an initiator group introduced onto the substrate surface, or chemical bonding between a layer provided on the substrate surface and a polymer, etc. In particular, from the viewpoint of excellent ice nucleation suppression and icing suppression at low temperatures, direct chemical bonding between a polymer chain and a compound constituting the substrate or an initiator group introduced onto the substrate surface is preferred. In this specification, the term "substrate" refers to a material to which polymer chains are fixed. The term "carrier" refers to a material having a layer on its surface containing brush-like polymer chain aggregates composed of multiple polymer chains. For example, in the member having the above-mentioned polymer brush structure, the substrate may be a material to which polymer chains are fixed, and the carrier may also be a material to which polymer chains are fixed. In the member having the above-mentioned bottle-brush structure, the substrate may be a trunk polymer, and the carrier may be a material to which the trunk polymer is adhered.

[0038] In the member of this embodiment, when the polymer chain assembly constitutes the polymer brush, the film thickness of the polymer brush, i.e., the film thickness of the polymer chain assembly, is preferably 10 nm or more, more preferably 50 nm or more, even more preferably 100 nm or more, even more preferably 300 nm or more, even more preferably 500 nm or more, and particularly preferably 1000 nm or more. There is no particular upper limit, but it can be, for example, 100 μm or less, or even 50 μm or less. When the polymer chain assembly is formed by self-assembly, the film thickness is preferably 1 nm or more, more preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 100 nm or more. There is no particular upper limit, but it can be, for example, 1 μm or less, or even 10 μm or less. The term "polymer chain assembly formed by self-assembly" means that individual polymer chains spontaneously form the polymer chain assembly.

[0039] Furthermore, in the member of this embodiment, when the polymer chain assembly has the bottle-brush structure, the film thickness of the layer containing the polymer chain assembly is preferably 2 nm or more, more preferably 50 nm or more, even more preferably 100 nm or more, still more preferably 300 nm or more, even more preferably 500 nm or more, and particularly preferably 1000 nm or more. There is no upper limit, but it can be, for example, 100 μm or less, or 50 μm or less.

[0040] Hereinafter, methods for forming polymer chain assemblies will be described for each of the polymer brush and the member having a bottle-brush structure.

[0041] [A] Polymer brush Polymer brush polymer chain assemblies can be obtained by graft polymerization, in which multiple polymer chains are attached to a substrate (support) as graft chains. This graft polymerization can be performed by either the grafting-from method or the grafting-to method, with the grafting-from method being preferred. Here, the grafting-from method involves introducing polymerization initiator groups into the substrate and growing graft chains from the polymerization initiator groups. The grafting-to method involves attaching pre-synthesized graft chains to reactive sites introduced into the substrate. Polymer chain assemblies can also be obtained by hydrophobically bonding the hydrophobic portion of a polymer (block copolymer) having a hydrophobic block and a hydrophilic block to the surface of a hydrophobic or hydrophobized substrate. Examples of block copolymers include copolymers with a polymethyl methacrylate (PMMA) structure as the hydrophobic block and a poly(sodium sulfonated glycidyl methacrylate) (PSGMA) structure as the hydrophilic block. Another polymer structure may be interposed between the PMMA and PSGMA structures. For details of this method, see Nature, 425, 163-165 (2003), for example.

[0042] (Graft polymerization method) A method for forming a polymer chain assembly by graft polymerization will be specifically described below.

[0043] - Polymer chain generation - The method for generating polymer chains used in graft polymerization is not particularly limited. However, radical polymerization is preferred, living radical polymerization (LRP) is more preferred, and atom transfer radical polymerization (ATRP) is even more preferred. Living radical polymerization has the advantage of easily controlling the molecular weight and molecular weight distribution of the polymer chains and producing various types of copolymers (e.g., random copolymers, block copolymers, compositionally gradient copolymers, etc.) as graft chains. Furthermore, living radical polymerization can produce concentrated polymer brushes (described below) with precise control of their density and thickness by using high-pressure conditions and ionic liquid solvents. Here, when using living radical polymerization, the graft polymerization method may be either the grafting-from method or the grafting-to method, but the grafting-from method is preferred. For details of graft polymerization methods that combine living radical polymerization and the grafting-from method, see, for example, JP-A-11-263819. For details of atom transfer radical polymerization, reference can be made to J. Am. Chem. Soc., 117, 5614 (1995), Macromolecules, 28, 7901 (1995), Science, 272, 866 (1996), and Macromolecules, 31, 5934-5936 (1998). Polymer chains can also be produced by nitroxide-mediated polymerization (NMP), reversible addition-fragmentation chain transfer (RAFT) polymerization, reversible transfer catalyzed polymerization (RTCP), and reversible complexation-mediated polymerization (RCMP).

[0044] The catalyst used in radical polymerization may be any catalyst capable of controlling radical polymerization, preferably a transition metal complex. Preferred examples of transition metal complexes include metal complexes with a central metal selected from Groups 7, 8, 9, 10, or 11 of the periodic table. Among these, copper complexes, ruthenium complexes, iron complexes, and nickel complexes are preferred, with copper complexes being even more preferred. The copper complex is preferably a complex of a monovalent copper compound and an organic ligand. Examples of monovalent copper compounds include cuprous chloride and cuprous bromide. Examples of organic ligands include 2,2'-bipyridyl or its derivatives, 1,10-phenanthroline or its derivatives, polyamines (e.g., tetramethylethylenediamine, pentamethyldiethylenetriamine, hexamethyltris(2-aminoethyl)amine), and polycyclic alkaloids such as L-(-)-sparteine. A divalent ruthenium chloride tristriphenylphosphine complex (RuCl2(PPh3)3) is also suitable as a catalyst. When a ruthenium compound is used as a catalyst, it is preferable to add an aluminum alkoxide as an activator. Other suitable catalysts include a bistriphenylphosphine complex of divalent iron (FeCl2(PPh3)2), a bistriphenylphosphine complex of divalent nickel (NiCl2(PPh3)2), and a bistributylphosphine complex of divalent nickel (NiBr2(PBu3)2).

[0045] The polymerization reaction is preferably carried out in a solvent. Examples of the solvent include hydrocarbon solvents (benzene, toluene, etc.), ether solvents (diethyl ether, tetrahydrofuran, diphenyl ether, anisole, dimethoxybenzene, etc.), halogenated hydrocarbon solvents (methylene chloride, chloroform, chlorobenzene, etc.), ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), alcohol solvents (methanol, ethanol, propanol, isopropanol, butyl alcohol, t-butyl alcohol, etc.), nitrile solvents (acetonitrile, propionitrile, benzonitrile, etc.), ester solvents (ethyl acetate, butyl acetate, etc.), carbonate solvents (ethylene carbonate, propylene carbonate, etc.), and the like. Examples of suitable solvents include fluorocarbons (e.g., carbonates), amide solvents (N,N-dimethylformamide, N,N-dimethylacetamide), hydrochlorofluorocarbon solvents (1,1-dichloro-1-fluoroethane, dichloropentafluoropropane), hydrofluorocarbon solvents (hydrofluorocarbons having 2 to 5 carbon atoms, hydrofluorocarbons having 6 or more carbon atoms), perfluorocarbon solvents (perfluoropentane, perfluorohexane), alicyclic hydrofluorocarbon solvents (fluorocyclopentane, fluorocyclobutane), oxygen-containing fluorine-containing solvents (fluoroethers, fluoropolyethers, fluoroketones, fluoroalcohols), and water. These solvents may be used alone or in combination of two or more.

[0046] -Introduction of polymerization initiating groups- To form polymer chain assemblies using, for example, the grafting-from method, polymerization initiator groups, which serve as the initiation point for the polymerization reaction, are introduced into the substrate, and polymer chains are grafted from these initiator groups using the polymerization methods described above. Examples of initiator groups include halogenated alkyl groups and halogenated sulfonyl groups. It is preferable for the initiator groups to be physically or chemically bonded to the substrate surface, as this allows for precise control of the density of grafted chains (graft density) and the primary structure of the resulting polymer chains (molecular weight, molecular weight distribution, and monomer arrangement). Methods for introducing (bonding) initiator groups to the substrate surface include chemical adsorption and the Langmuir-Blodgett (LB) method. For example, chlorosulfonyl groups (polymerization initiation groups) can be introduced onto the surface of a silicon wafer (substrate) by chemical bonding by reacting 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane or 2-(4-chlorosulfonylphenyl)ethyltrichlorosilane with the oxide layer on the surface of the silicon wafer.

[0047] To introduce polymerization initiator groups using the LB method, a film-forming material containing the polymerization initiator groups is dissolved in an appropriate solvent (e.g., chloroform, benzene, etc.). A small amount of this solution is then spread on a clean liquid surface, preferably pure water, and the solvent is evaporated or diffused into an adjacent aqueous phase to form a low-density film of film-forming molecules on the water surface. A partition plate is then mechanically swept across the water surface to reduce the surface area of ​​the water surface on which the film-forming molecules are spread, thereby compressing the film and increasing its density, resulting in a dense monolayer on the water surface. Next, under appropriate conditions, while maintaining a constant surface density of the molecules constituting the monolayer on the water surface, the substrate on which the monolayer is to be deposited is immersed or raised across the monolayer, transferring the monolayer onto the substrate and depositing the monolayer on the substrate. For details of the LB method, please refer to "New Experimental Chemistry Lectures, Vol. 18 (Interfaces and Colloids), Chapter 6, by Fukuda Kiyonari et al., (1977), Maruzen" or "LB Films and Electronics, edited by Fukuda Kiyonari, Sugi Michio, and Suzumebe Hiroyuki, (1986), CMC" or "Practical Techniques for Making Good LB Films, by Ishii Yoshio, (1989), Kyoritsu Shuppan."

[0048] When introducing a polymerization initiating group onto the surface of a substrate, it is preferable to treat the surface of the substrate with a surface treatment agent having at least one of a group that bonds to the substrate and a group that has affinity for the substrate, and at least one of a group that bonds to the polymerization initiating group and a group that has affinity for the polymerization initiating group. This surface treatment agent may be a low molecular weight compound or a high molecular weight compound. Examples of surface treatment agents include compounds represented by the following formula (10): [ka] In formula (10), n is an integer of 1 to 10, and preferably an integer of 3 to 8. R 11 , R 12 and R 13 R each independently represents a substituent. 11 , R 12 and R 13 At least one of R is preferably an alkoxyl group or a halogen atom, 11 , R 12and R 13 It is particularly preferred that all of R are methoxy groups or ethoxy groups. 14 and R 15 R each independently represents a substituent. 14 and R 15 are preferably each independently an alkyl group having 1 to 3 carbon atoms or an aromatic functional group, and R 14 and R 15 Most preferably, both X are methyl groups. 11 represents a halogen atom, preferably a bromine atom.

[0049] It is preferable to use a silane coupling agent containing a polymerization initiator group (a polymerization initiator group-containing silane coupling agent) as the surface treatment agent. This allows surface treatment and the introduction of the polymerization initiator group to be carried out simultaneously. Examples of the polymerization initiator group-containing silane coupling agent include compounds represented by the above formula (10). For a description of the polymerization initiator group-containing silane coupling agent and its manufacturing method, reference can be made to the description in International Publication No. 2006 / 087839. Specific examples of the polymerization initiator group-containing silane coupling agent include (2-bromo-2-methyl)propionyloxyhexyltrimethoxysilane (BHM) and (2-bromo-2-methyl)propionyloxypropyltrimethoxysilane (BPM).

[0050] From the viewpoint of adjusting the graft density, when a polymerization initiator group-containing silane coupling agent is used as a surface treatment agent, it is preferable to use a silane coupling agent that does not contain a polymerization initiator group, such as a known alkyl silane coupling agent. This allows the graft density to be freely adjusted by adjusting the ratio of the polymerization initiator group-containing silane coupling agent to the silane coupling agent that does not contain a polymerization initiator group. For example, when all silane coupling agents are polymerization initiator group-containing silane coupling agents, graft polymerization using the grafting-from method after surface treatment can grow polymer chains with a surface occupancy ratio of greater than 0.03. When a polymerization initiator group-containing silane coupling agent is used as a surface treatment agent, the polymerization initiator group-containing silane coupling agent may be hydrolyzed in the presence of water to form silanols, which may then be partially condensed into an oligomer before being subjected to surface treatment. Specifically, the oligomer may be adsorbed onto a substrate, such as silica, via hydrogen bonding, followed by drying to cause a dehydration condensation reaction, thereby introducing the polymerization initiator group into the substrate.

[0051] (base material) In a polymer brush-type polymer chain assembly, the material constituting the substrate (carrier) to which the polymer chains are fixed is not particularly limited and can be appropriately selected from organic materials, inorganic materials, metal materials, etc. The substrate is preferably a carrier made of a material different from the polymer chain assembly.

[0052] The organic material is not particularly limited, and various resins and rubbers can be used without limitation. 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-based resins such as polyethylene, polypropylene, polystyrene, and polycycloolefin; vinyl-based resins such as polystyrene, acrylic resins, polyvinyl chloride resins, and polyvinyl alcohol; fluorine-based resins such as polytetrafluoroethylene; polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and polyethylene naphthalate; and silicone resins such as polydimethylsiloxane. Examples of rubber include diene-based rubbers such as butadiene rubber, styrene-butadiene rubber, chloroprene rubber, isoprene rubber, natural rubber, nitrile rubber, and butyl rubber; and rubbers other than diene-based rubbers such as ethylene propylene rubber, acrylic rubber, polyether rubber, polyurethane rubber, fluororubber, and silicone rubber.

[0053] The substrate may be a polymer monolith, which refers to a polymeric porous body having a three-dimensional co-continuous structure formed by three-dimensionally interconnected pores and a polymer skeleton. The polymer backbone of the polymer monolith is preferably a polymer of a polymerizable compound and a crosslinking agent. When using a polymer monolith as the substrate, it is preferable that it be an immiscible system. This improves liquid retention. By using a polymer monolith as the substrate, this becomes possible by combining a fine co-continuous structure with the osmotic pressure effect of the brush. Furthermore, by making the polymer monolith thicker, it can also function as a tank for storing oil and other substances. By modifying the surface of the polymer monolith with a polymer brush, it is possible to absorb these substances onto the surface.

[0054] The polymerizable compound may be any compound capable of forming a polymer skeleton by polymerization with a crosslinking agent, and examples thereof include epoxy compounds, (meth)acrylate compounds, and styrene compounds. Of these, epoxy compounds are preferred because they are highly flexible and can easily form polymer monoliths with a fine porous structure. Examples of the epoxy compounds include bisphenol A epoxy resins, brominated bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AD ​​epoxy resins, stilbene epoxy resins, biphenyl epoxy resins, bisphenol A novolac epoxy resins, cresol novolac epoxy resins, diaminodiphenylmethane epoxy resins, polyphenyl-based epoxy resins such as tetrakis(hydroxyphenyl)ethane-based epoxy resins, fluorene-containing epoxy resins, and 2,2,2-tri-(2,3-epoxypropyl)-isocyanate. Examples of epoxy compounds include epoxy resins containing heteroaromatic rings, such as triglycidyl isocyanurate and triazine ring-containing epoxy resins; aromatic epoxy compounds containing carbon atoms derived from aromatic rings, such as N,N,N',N'-tetraglycidyl-m-xylylenediamine; and aliphatic epoxy compounds not containing carbon atoms derived from aromatic rings, such as aliphatic glycidyl ether epoxy resins, aliphatic glycidyl ester epoxy resins, alicyclic glycidyl ether epoxy resins, alicyclic glycidyl ester epoxy resins, and 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane. Among these, bifunctional or higher functional epoxy compounds are preferred, with compounds containing two or more glycidyl groups in the molecule being more preferred. A preferred example is 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane.

[0055] Examples of the crosslinking agent include amine compounds, acid anhydrides, phenol compounds, and hydrazide compounds. Examples of the amine compound include aromatic amine compounds such as m-phenylenediamine, p-phenylenediamine, o-phenylenediamine, 4,4'-diaminodiphenyl sulfone, 4,4'-methylene-bis(2-chloroaniline), benzyldimethylamine, and dimethylaminomethylbenzene; aromatic amine compounds having a heteroaromatic ring such as a triazine ring; ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, bis(hexamethylene)triamine, 1,3,6-trisaminomethylhexane, and polyamines. Alicyclic amine compounds such as dimethyldiamine, trimethylhexamethylenediamine, polyetherdiamine, isophoronediamine, menthanediamine, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)2,4,8,10-tetraoxaspiro(5,5)undecane adduct, bis(4-aminocyclohexyl)methane, and modified products thereof; aliphatic polyamine hydrazide compounds such as 1,6-hexamethylenebis(N,N-dimethylsemicarbazide); and aliphatic polyamidoamines and polyaminoamides formed from polyamines and dimer acids. Examples of the acid anhydride include aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, and pyromellitic anhydride. The phenol compound may, for example, be a novolac type phenol resin. Examples of the hydrazide compound include aromatic hydrazide compounds such as isophthalic acid dihydrazide; and aliphatic hydrazide compounds such as adipic acid dihydrazide, sebacic acid dihydrazide, and dodecanedioic acid dihydrazide.

[0056] It is preferable to select a crosslinking agent appropriately depending on the type of polymerizable compound. When an epoxy compound is used as the polymerizable compound, the crosslinking agent is preferably an amine compound, more preferably a bifunctional or higher functional amine compound having two or more amino groups in the molecule. The bifunctional or higher functional amine compound is preferably an alicyclic amine compound. A preferred example is bis(4-aminocyclohexyl)methane.

[0057] The polymer backbone of the polymer monolith is preferably a polymer of a difunctional or higher epoxy compound and a difunctional or higher amine compound, and more preferably a polymer of a difunctional or higher aliphatic epoxy compound and a difunctional or higher alicyclic amine compound, in view of the ease of forming the polymer monolith.

[0058] The blending ratio of the polymerizable compound and the crosslinking agent may be determined taking into consideration the crosslinking density, etc. For example, when the polymerizable compound is a bifunctional or higher epoxy compound and the crosslinking agent is a bifunctional or higher amine compound, it is preferable to adjust the amine equivalent of the crosslinking agent to be in the range of 0.6 to 1.5 per equivalent of the epoxy group of the polymerizable compound.

[0059] The polymer monolith can be formed, for example, from a polymer monolith-forming composition containing a polymerizable compound, a crosslinker, and a pore-forming agent. More specifically, the polymer monolith-forming composition is applied to a substrate as a carrier to form a coating film, and the coating film is cured. Polymerization of the polymerizable compound increases the polymer component, causing spinodal decomposition and the development of a co-continuous structure. The pore-forming agent is then removed from the cured film to form the polymer monolith.

[0060] The surface on which the polymer monolith is to be formed may be treated with a known coupling agent such as a silane coupling agent, or may be subjected to plasma treatment, in order to improve affinity with the polymer monolith-forming composition.

[0061] The inorganic material is not particularly limited, and examples thereof include ceramics (e.g., alumina ceramics, bioceramics, composite ceramics such as zirconia-alumina composite ceramics, etc.), metals (e.g., iron, cast iron, steel, stainless steel, carbon steel, iron alloys such as high carbon chromium bearing steel (SUJ2), non-ferrous metals and non-ferrous alloys such as aluminum, zinc, copper, and titanium, etc.), silicon such as polycrystalline silicon, silicon oxide, silicon nitride, various types of glass, quartz, and composite materials thereof.

[0062] The type of substrate is not particularly limited. Examples include tubes, sheets, fibers, strips, films, plates, foils, membranes, pellets, powders, particles, molded products (e.g., extrusion molded products, cast molded products, etc.), etc. Furthermore, the article to which the member of the present embodiment is applied may itself be used as the substrate.

[0063] (Other manufacturing methods) Furthermore, polymer brush polymer chain assemblies can also be produced by the following production method. Specifically, the method includes the steps of: mixing, in a solvent, an organic material constituting a substrate (hereinafter also referred to as substrate polymer) with a plurality of block copolymers each comprising a polymer block A and a polymer block B having a lower affinity for the substrate polymer than the polymer block A, and each having polymer block A at at least two locations, to prepare a mixed solution; and removing the solvent from the mixed solution to cause phase separation. This production method makes it possible to produce polymer chain assemblies of polymer brushes with a loop structure, in which both ends of the polymer chains constituting the polymer chain assembly are fixed to a substrate, which is a carrier.

[0064] The organic material constituting the base material, which is a base polymer, is not particularly limited, and examples thereof include those mentioned above.

[0065] The block copolymer is not particularly limited as long as it comprises a polymer block A and a polymer block B that has a lower affinity for the base polymer than the polymer block A, and has the polymer block A at at least two locations. However, from the viewpoint of favorable formation of a loop structure, it is preferable to use a polymer block B that is incompatible with the base polymer, and a combination in which the polymer block B is incompatible with the base polymer and the polymer block A is compatible with the base polymer is more preferable.

[0066] Here, the miscibility of polymer block A with the base polymer refers to the following state: When a polymer consisting only of polymer block A is mixed with the base polymer by hot melt mixing, co-solution mixing, or the like, and the resulting mixture is solidified by cooling or solvent evaporation, or the like, and the glass transition temperature (Tg) of the resulting sample is measured, it can be determined that the polymer is miscible if a Tg different from that of the polymer consisting only of polymer block A and that of the base polymer is observed in a temperature range between these two. The immiscibility of the polymer block B with the base polymer refers to the following state: When a polymer consisting only of the polymer block B is mixed with the base polymer by hot melt mixing, co-solution mixing, or the like, and the resulting mixture is solidified by cooling or solvent evaporation, or the like, and the glass transition temperature (Tg) of the obtained sample is measured, it can be determined that the polymer block B is immiscible with the base polymer if no other Tg is observed besides the Tg of the polymer consisting only of the polymer block B and the Tg of the base polymer.

[0067] The polymer block A and the polymer block B may be those having the above-mentioned compatibility with the base polymer. From the viewpoint of favorably forming a loop structure, the difference in SP value (solubility parameter) between the polymer block A and the polymer block B is 1.5 (MPa). 0.5 It is preferable that the pressure is 3 (MPa) or more. 0.5 More preferably, it is 5 (MPa) or more. 0.5 It is more preferable that the difference between the SP value of the polymer block A and the SP value of the base polymer is 0.5 (MPa) or more. 0.5 It is preferable that the pressure is 0.3 (MPa) or less. 0.5 More preferably, it is 0.2 (MPa) or less. 0.5 With respect to the SP value of the polymer block B, it is more preferable that the difference between the SP value of the polymer block B and the SP value of the base polymer is 1.5 (MPa) or less. 0.5It is preferable that the pressure is 3 (MPa) or more. 0.5 More preferably, it is 5 (MPa) or more. 0.5 It is more preferable that the SP values ​​of polymer block A and polymer block B are equal to or greater than 1. The SP values ​​of polymer block A and polymer block B may be, for example, values ​​disclosed in Polymer Handbook (4th edition, Wiley-Interscience).

[0068] The polymer block A is not particularly limited as long as it satisfies the above-mentioned properties and may be selected in relation to the base polymer to be used. Specific examples include polymer blocks composed of polymer segments that constitute the resins or rubbers exemplified above as the resins or rubbers that constitute the base polymer.

[0069] The molecular weight (weight average molecular weight (Mw)) of the polymer block A portion of the block copolymer is not particularly limited, but from the viewpoint of exhibiting sufficient interaction with the base polymer and thereby more appropriately supporting the loop structure formed by the polymer block B, thereby further enhancing durability, it is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, even more preferably 1,000 to 20,000, still more preferably 2,000 to 20,000, and particularly preferably 2,000 to 6,000.

[0070] As the polymer block B, of the polymer chains described above, those which satisfy the above-mentioned properties with respect to the base polymer are preferably used.

[0071] The solvent used when mixing the base polymer and the plurality of block copolymer chains in a solvent is not particularly limited, and any solvent that can dissolve or disperse the base polymer and the block copolymer chains may be used. Examples of such hydrocarbons include aliphatic hydrocarbons such as n-pentane, n-hexane, and n-heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, tricyclodecane, hexahydroindene, and cyclooctane; aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; nitrogen-containing hydrocarbons such as nitromethane, nitrobenzene, acetonitrile, propionitrile, and benzonitrile; ethers such as diethyl ether, tetrahydrofuran, and dioxane; ketones such as acetone, ethyl methyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, ethyl propionate, and methyl benzoate; halogenated hydrocarbons such as chloroform, dichloromethane, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, and trichlorobenzene; and alcohols such as methanol and ethanol.

[0072] A mixture can be obtained by mixing a base polymer and multiple block copolymer chains in such a solvent and dissolving or dispersing them. The resulting mixture is then used to form a film by a casting method, spin coating, or the like, and the solvent is then removed from the resulting mixture. By removing the solvent, some of the multiple block copolymer chains dispersed in the base polymer undergo phase separation from the base polymer, with polymer block A remaining in a compatible state with the base polymer, while polymer block B constituting the block copolymer chain undergoes phase separation from the base polymer, resulting in a state in which polymer block A is present in the base polymer and polymer block B is exposed from the base polymer. This allows the formation of a loop structure in which both ends of the polymer chains constituting the polymer chain assembly are fixed to a support.

[0073] The method for removing the solvent is not particularly limited and may be selected depending on the type of solvent used, but a method of heating at 50 to 100°C is preferred, and a method of heating at 70 to 80°C is more preferred.

[0074] Alternatively, polymer brush polymer chain assemblies can be produced by the following production method: That is, they can be produced by a production method comprising the steps of: mixing, under heating, a base polymer with a plurality of block copolymers each comprising a polymer block A and a polymer block B having a lower affinity for the base polymer than the polymer block A, and each having polymer block A at at least two locations, to prepare a molten mixture; and cooling the molten mixture to cause phase separation. This production method also makes it possible to produce polymer chain assemblies of polymer brushes with a loop structure, in which both ends of the polymer chains that make up the polymer chain assembly are fixed to a substrate, which is a carrier.

[0075] The heating temperature when preparing a molten mixture by mixing a base polymer and a plurality of block copolymers under heating is not particularly limited, and may be a temperature at which the base polymer or the block copolymers melt, preferably a temperature at which both the base polymer and the block copolymer chains melt, and is preferably 40 to 300°C, more preferably 80 to 200°C.

[0076] The resulting molten mixture is then formed into a film by casting, spin coating, dip coating, or other methods, and then cooled to solidify, causing phase separation. As part of the melt-mixed block copolymers dispersed in the base polymer changes from a molten state to a solid state, polymer block A remains in a compatible state with the base polymer, while polymer block B, which constitutes the block copolymer, undergoes phase separation from the base polymer, resulting in a state in which polymer block A is contained within the base polymer and polymer block B is exposed from the base polymer, thereby forming a loop structure.

[0077] The method for cooling the molten mixture is not particularly limited, but examples include a method in which the molten mixture formed into a film is allowed to stand at room temperature, or a method in which the molten mixture is heated to a temperature lower than the melting temperature of each component constituting the molten mixture and then allowed to stand.

[0078] (Number average molecular weight and molecular weight distribution index of polymer chains) The number average molecular weight (Mn) of the polymer chains constituting the polymer chain assembly is preferably 500 to 10,000,000, and more preferably 100,000 to 10,000,000. The molecular weight distribution index (PDI=Mw / Mn) of the polymer chain assembly is preferably 1.0 to 2.0, more preferably 1.0 to 1.5. When the molecular weight distribution index is within the above range, it can be expected that the polymer chains constituting the polymer chain assembly can maintain a high density state up to the outermost surface. The number-average molecular weight (Mn) and molecular weight distribution index (Mw / Mn) of the polymer chain aggregate can be measured by cutting out the polymer chains from the substrate by treatment with hydrofluoric acid and then performing molecular weight analysis on the cut polymer chains using size exclusion chromatography such as gel permeation chromatography. Furthermore, when polymer chain assemblies are formed using graft polymerization, it is possible to assume that the free polymer produced during the polymer chain polymerization reaction has the same molecular weight as the polymer chain immobilized on the substrate, measure the number-average molecular weight (Mn) and molecular weight distribution index (Mw / Mn) of the free polymer using size exclusion chromatography, and use these values ​​as the number-average molecular weight (Mn) and molecular weight distribution index (Mw / Mn) of the polymer chain. It has been confirmed that the number-average molecular weight (Mn) and molecular weight distribution index (Mw / Mn) of the polymer chain immobilized on the substrate are nearly equal to those of the free polymer produced during the polymerization reaction.

[0079] We will now explain in detail how to measure molecular weight using free polymers. When polymer chains are synthesized by surface-initiated living radical polymerization, adding a free initiator to the polymerization solution can yield free polymers with molecular weights and molecular weight distributions equivalent to those of the polymer chains that make up the polymer chain aggregate. The free polymers are analyzed by size exclusion chromatography to determine the number average molecular weight (Mn) and molecular weight distribution index (Mw / Mn).

[0080] The analysis by size exclusion chromatography involves calibration using available, homogeneous, monodisperse standard samples with known molecular weights, and absolute molecular weight evaluation using a multi-angle light scattering detector. In the examples herein, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) values ​​are shown as absolute values ​​appropriately calculated using a multi-angle light scattering detector and molecular weight calibration curves of various standard samples. Examples of standard samples include polystyrene standard samples, polymethyl methacrylate standard samples, and polyethylene glycol standard samples.

[0081] The density of polymer chains on the substrate surface is 0.01 chains / nm 2 It is preferable that the number of chains is 0.05 or more. 2 More preferably, it is 0.1 chains / nm or more. 2 More preferably, it is 0.2 chains / nm or more. 2 The upper limit is not particularly limited, but is preferably 1.0 chain / nm. 2 Can be less than 0.9 chains / nm 2 It can also be the following:

[0082] The density of the polymer chains can be calculated by measuring the graft amount (W) per unit area and the number average molecular weight (Mn) of the polymer chain aggregate, and using the following formula: Polymer chain density (chains / nm 2 )=W(g / nm 2 ) / Mn×(Avogadro's number) In the formula, W represents the graft amount per unit area, and Mn represents the number average molecular weight of the polymer chain aggregate. When the substrate is a flat substrate such as a silicon wafer, the graft amount per unit area (W) can be determined by measuring the film thickness in a dry state, i.e., the thickness of the polymer chain assembly layer in a dry state, by ellipsometry, and calculating the graft amount per unit area (W) using the density of the bulk film. The number average molecular weight (Mn) of the polymer chain assembly can be measured by the method described above.

[0083] The surface occupancy of the polymer chains on the substrate surface (cross-sectional area of ​​the polymer × density of the polymer chains) is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.10 or more. The surface occupancy means the proportion of the substrate surface occupied by grafting points (first structural units), and is 1 in the case of closest packing. The density of the polymer chains can be calculated using the method described above. The cross-sectional area of ​​the polymer can be determined using the repeating unit length in the extended form of the polymer and the bulk density of the polymer. The surface occupancy of the polymer chains on the substrate surface is preferably 0.08 to 0.65, more preferably 0.1 to 0.4, and even more preferably 0.15 to 0.25 from the viewpoint of preventing snow from adhering outdoors.

[0084] When the member of this embodiment has a polymer brush structure, from the viewpoint of obtaining an excellent anti-icing effect over a wide temperature range of 0°C to -18°C, it is preferable that the substrate is a carrier made of a material other than the polymer chain assembly, and that the surface occupancy of the polymer chains on the substrate surface is 0.08 to 0.40 (preferably 0.10 to 0.40, more preferably 0.15 to 0.40). In particular, when the member has a polymer brush structure, if the surface occupancy is within the above range, the brush density will be in an appropriate range, improving the retention of liquid substances (especially for liquid substances that are not phase with water, the retention is greatly improved), and further improving the suppression of ice nucleation due to the size exclusion effect.

[0085] [B] Member with bottle brush structure Next, a member having a bottle brush structure will be described. The bottle brush structure refers to a branched polymer structure in which multiple side chains branch off from the main chain, forming a bottle brush-like shape as a whole. In the bottle brush structure, the main chain constitutes the substrate, and the side chains constitute the polymer chain assembly. Furthermore, the bottle brush structure may be adhered to a support to form a member having the bottle brush structure. Examples of the support include those described above. In this case, both the bottle brush and the polymer brush may be fixed or adhered to the support. In this case, the polymer brush is preferably a dense polymer brush. The member of this embodiment is preferably a member having a bottle brush structure in which the plurality of polymer chains are bonded as side chains to the polymer chain that is the base material.

[0086] Components with a bottle-brush structure can also be obtained by graft polymerization. Graft polymerization can be performed using a grafting-to method, in which a pre-synthesized reactive side chain (graft chain) is bonded to a backbone polymer, which serves as the main chain; a grafting-from method, in which a side chain (graft chain) grows from the polymerization initiator group of a macroinitiator (a backbone polymer with a polymerization initiator group introduced); or a grafting-through method, in which a macromonomer (a polymer with a polymerizable functional group at the end of a side chain polymer) is polymerized. Furthermore, these side chains and backbone polymers can be synthesized using living anionic polymerization, ring-opening metathesis polymerization (ROMP), or the versatile living radical polymerization (LRP). A preferred example of a component with a bottle-brush structure is the compound represented by formula (11). [ka] In formula (11), R 1 and R 2 each independently represents a hydrogen atom or a methyl group, and R 3 represents a substituent, and is preferably an alkyl group having 1 to 10 carbon atoms. 4 and R 5represents an end group consisting of an atom or atomic group, and examples thereof include a hydrogen atom, a halogen, and a functional group derived from a polymerization initiator. X represents O or NH, Y represents a divalent organic group, n represents an integer of 10 or more, and Polymer A represents a polymer chain. In the compound represented by formula (11), the repeating structure of the structural units bounded by n corresponds to the main chain of the bottle brush structure, and Polymer A corresponds to the side chain of the bottle brush structure.

[0087] Examples of the organic group represented by Y include an alkylene group having 1 to 10 carbon atoms, an oxyalkylene group (RO) having 1 to 5 carbon atoms (R represents an alkylene group having 1 to 5 carbon atoms), a linked structure in which multiple oxyalkylene groups are linked, and a divalent organic group formed by combining at least two of these organic groups (alkylene groups having 1 to 10 carbon atoms, oxyalkylene groups having 1 to 5 carbon atoms, and linked structures of oxyalkylene groups). Here, the alkylene group and the alkylene group of the oxyalkylene group may be linear or branched, or may have a cyclic structure. Specific examples of the alkylene group include an ethylene group, a propylene group, a butylene group, and a cyclohexylene group. The alkylene group and the alkylene group of the oxyalkylene group may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, and a heteroaryl group having 3 to 40 carbon atoms, and these substituents may be further substituted with a substituent. For an explanation of Polymer A, the preferred range, and specific examples, please refer to the polymer chain described above. In Polymer A, the structural units of the main chain may be the same or different from each other.

[0088] When a component with a bottle-brush structure is considered to have a central axis, with side chains (graft chains) extending linearly from the central axis and a surface (virtual periphery) including the tips of the chains, the outer shape of the component can be considered as a cylinder with the surface including the tips as the side. In a component with such an outer shape, the longer the side chains (graft chains), the lower the density of the side chains (graft chains) on the side, and the greater the structural freedom of the side chains (graft chains). As a result, the side chains (graft chains) can be freely folded.

[0089] In materials with a bottle-brush structure, the surface occupancy of side chains (σ * ) can be calculated using the following formula:

number

[0090] The surface occupancy of the side chains of the member having a bottle-brush structure is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.10 or more. The surface occupancy of the side chains is preferably 0.08 to 0.65, more preferably 0.1 to 0.5, and even more preferably 0.2 to 0.4.

[0091] The density of the side chains of the bottle-brush structure is 0.01 chains / nm 2 It is preferable that the number of chains is 0.05 or more. 2 More preferably, it is 0.1 chains / nm or more. 2 More preferably, it is 0.2 chains / nm or more. 2 The upper limit is not particularly limited, but is preferably 1.0 chain / nm. 2 Can be less than 0.9 chains / nm 2 It can also be the following:

[0092] The number average molecular weight of the member having a bottle-brush structure is preferably 1,000 to 10,000,000, more preferably 1,000 to 1,000,000, and even more preferably 5,000 to 500,000.

[0093] The molecular weight distribution index (PDI=Mw / Mn) of the member having a bottle-brush structure is preferably 1.0 to 2.0, more preferably 1.0 to 1.5. If the molecular weight distribution index is within the above range, it can be expected that the polymer chains constituting the polymer chain assembly can maintain a high density state up to the outermost surface.

[0094] When the member of this embodiment is a member having a bottle brush structure, the member has a bottle brush structure in which the plurality of polymer chains are bonded as side chains to the base polymer chain, and the member having the bottle brush structure preferably has a surface occupancy rate of the side chains of 0.08 to 0.50 (more preferably 0.10 to 0.50, and even more preferably 0.15 to 0.50).

[0095] [Liquid substance] The layer containing the polymer chain assembly of the member of this embodiment holds a liquid substance. Examples of the liquid substance include water, ionic liquid, fluorine-based solvent, and oil (hydrocarbon oil, silicone oil, etc.), and it is preferable that the liquid substance be at least one selected from water and ionic liquid. The liquid substance may be a hydrophilic liquid substance or a hydrophobic liquid substance. Examples of hydrophilic liquid substances include water and hydrophilic ionic liquid. Examples of hydrophobic liquid substances include hydrophobic ionic liquid, fluorine-based solvent, and oil. The liquid substance may be composed of only one type of liquid substance, or may be a mixture of two or more types of liquid substances. The liquid substance may contain an additive.

[0096] Ionic liquids, also known as ionic liquids or room-temperature molten salts, are ionically conductive salts with low melting points. Many ionic liquids have relatively low melting points, which are obtained by combining an organic onium ion as the cation with an organic or inorganic anion as the anion. The melting point of an ionic liquid is usually 100°C or lower, preferably room temperature (25°C) or lower. The melting point of an ionic liquid can be measured using a differential scanning calorimeter (DSC) or the like.

[0097] The ionic liquid may be a compound represented by the following formula (20): The melting point of this ionic liquid is preferably 50°C or lower, more preferably 25°C or lower. [ka] In equation (20), R 21 , R 22 , R 23 and R 24 are each independently an alkyl group having 1 to 5 carbon atoms, or R'-O-(CH2) n -, R' represents a methyl group or an ethyl group, and n is an integer of 1 to 4. 21 , R 22 , R 23 and R 24may be the same or different. 21 , R 22 , R 23 and R 24 Any two of R may be bonded to each other to form a cyclic structure. 21 , R 22 , R 23 and R 24 At least one of X is an alkoxyalkyl group. 21 represents a nitrogen atom or a phosphorus atom, and Y represents a monovalent anion.

[0098] R 21 , R 22 , R 23 and R 24 Examples of the alkyl group having 1 to 5 carbon atoms in the formula include a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, and an n-pentyl group. R 21 , R 22 , R 23 and R 24 In the formula, R'-O-(CH2) n The alkoxyalkyl group represented by - is preferably a methoxymethyl group or an ethoxymethyl group, a 2-methoxyethyl group or a 2-ethoxyethyl group, a 3-methoxypropyl group or a 3-ethoxypropyl group, a 4-methoxybutyl group or a 4-ethoxybutyl group, or the like. R 21 , R 22 , R 23 and R 24 Compounds in which any two of the above are bonded to form a ring structure include X 21 When a nitrogen atom is used for X, a quaternary ammonium salt having an aziridine ring, an azetidine ring, a pyrrolidine ring, a piperidine ring, or the like is preferred. 21 When a phosphorus atom is used, a quaternary phosphonium salt having a pentamethylenephosphine (phosphorinane) ring or the like is preferred. Furthermore, as the quaternary ammonium salt, one having, as a substituent, a methyl group for R' and at least one 2-methoxyethyl group where n is 2 is preferred. The monovalent anion in Y is BF4- , PF6 - , AsF6 - , SbF6 - , AlCl4 - , NbF6 - , HSO4 - , ClO4 - , CH3SO3 - , CF3SO3 - , CF3CO2 - , (CF3SO2)2N - , Cl - , Br - , I - BF4 - , PF6 - , (CF3SO2)2N - , CF3SO3 - , or CF3CO2 - It is preferable that:

[0099] The ionic liquid is R 21 is a methyl group, and R 23 and R 24 is an ethyl group, and R 24 is R'-O-(CH2) n Compounds having a structure in which the alkoxyalkyl group is represented by the formula - are preferably used.

[0100] Among the compounds represented by formula (20), specific examples of the quaternary ammonium salt and quaternary phosphonium salt that can be suitably used include the compounds shown below. [ka]

[0101] Furthermore, as the ionic liquid, an ionic liquid containing an imidazolium ion or an ionic liquid containing an aromatic cation can also be used.

[0102] The liquid substance is preferably immiscible with water. "Immiscible with water" means that when water and a liquid substance are stirred at room temperature overnight, allowed to stand at room temperature for 1 hour, and then the liquid substance alone is taken out and subjected to NMR measurement, the water content is 5% or less.

[0103] In the member of this embodiment, it is preferable that the polymer chain assembly does not swell in water and that the liquid substance is not miscible with water. In the member of this embodiment, the difference between the icing stress at −8° C. and that at −18° C. are small, and from the viewpoint of excellent ice nucleation and icing suppression effects at around −18° C., the liquid substance and the polymer chain are preferably a water-compatible polymer chain (preferably water and poly(alkylene glycol) mono(meth)acrylate); an ionic liquid and an incompatible polymer chain (preferably, X is a nitrogen atom and R 21 and R 22 and bond to each other to form a ring structure R 23 is an alkyl group having 1 to 5 carbon atoms, and R 24 is R'-O-(CH2) n - a monopolymer of an ionic liquid of formula (20), which is an alkoxyalkyl group represented by the formula (21), and an alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms; or a hydrocarbon-based oil and an incompatible polymer chain (preferably a monopolymer of a poly-α-olefin and an alkyl methacrylate having an alkyl group having 10 to 15 carbon atoms).

[0104] The method for retaining a liquid substance in the layer containing polymer chain assemblies is not particularly limited. Examples include a method in which a liquid substance is applied to the surface of the layer containing polymer chain assemblies and then allowed to stand to retain the liquid substance, and a method in which a substrate on which a layer containing polymer chain assemblies has been formed is immersed in a liquid substance. Alternatively, the polymer chain assemblies may absorb moisture from the atmosphere to retain water as a liquid substance in the layer containing polymer chain assemblies.

[0105] [Material characteristics] The member of this embodiment has an icing stress at -18°C of 150 kPa or less, preferably 100 kPa or less, more preferably 80 kPa or less, more preferably 65 kPa or less, even more preferably 50 kPa or less, even more preferably 35 kPa or less, and particularly preferably 20 kPa or less. The icing stress at -18°C can be measured by the method described in the Examples below. The above-mentioned ice adhesion stress at -18°C can be adjusted by the type of polymer chain, the type of liquid substance, and the surface occupancy of the polymer chain.

[0106] The ice adhesion 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 adhesion stress at -8°C is within the above range, an excellent ice adhesion suppression effect can be obtained over a wide temperature range from 0°C to -18°C. The icing stress at -8°C can be measured by the method described in the Examples below. The above-mentioned ice adhesion stress at -8°C can be adjusted by the type of polymer chain, the type of liquid substance, and the surface occupancy of the polymer chain.

[0107] The difference between the ice formation stress of the member of this embodiment at -18°C and that at -8°C 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 ice formation suppression effect can be obtained over a wide temperature range from 0°C to -18°C, and in particular, when a compatible polymer chain is used as the polymer chain, an especially excellent ice formation suppression effect can be obtained at 0°C to -20°C. The member of this embodiment preferably has a higher icing stress at -18°C than at -8°C. In this specification, the difference between the icing stress at -18°C and the icing stress at -8°C refers to the absolute value of the difference.

[0108] In this embodiment, the contact angle of the component surface with water at 25°C 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, better effects of suppressing water droplet adhesion, icing, and ice nucleation can be obtained. In this specification, the value of the contact angle of the component surface with water is determined by dropping 1 μL of water on the component surface and measuring the contact angle of water on the component surface one second after the drop has landed.

[0109] [Part Shape] The shape of the member of this embodiment is not particularly limited, and examples thereof include a tube, sheet, fiber, strip, film, plate, foil, membrane, pellet, powder, and particle shape.

[0110] [Application form of components] The member of this embodiment can be applied to various articles, such as window glass, vehicle glass, mirrors, piping, and containers. The member of this embodiment does not change its icing stress significantly in the temperature range of 0°C to -20°C, and therefore can be suitably used in applications where icing needs to be suppressed over a wide temperature range of 0°C to -20°C. [Example]

[0111] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0112] Example 1 The silicon wafer and DSC pan (made of aluminum) were ultrasonically cleaned in acetone for 30 minutes, chloroform for 30 minutes, and 2-propanol for 30 minutes, respectively. Both surfaces of the silicon wafer and DSC pan were then irradiated with UV ozone for 30 minutes. Next, only the DSC pan was coated with silica. The silicon wafer and silica-coated DSC pan were then ultrasonically cleaned in ethanol for 30 minutes, after which they were immersed in a mixture of (2-bromo-2-methyl)propionyloxypropyltrimethoxysilane (BPM), ethanol, and aqueous ammonia in a ratio of 1:89:10 (by mass). This immersion time was 24 hours, during which polymerization initiator groups were introduced into the silicon wafer and DSC pan. Next, methoxypoly(ethylene glycol) methacrylate (manufactured by Aldrich, code 10 ... 447943, number average molecular weight = 500) (hereinafter referred to as PEGMA), ethyl 2-bromo-2-methylpropionate (hereinafter referred to as EBIB), a mixture of cuprous bromide (hereinafter referred to as CuBr(I)), cupric bromide (hereinafter referred to as CuBr(II)), and 4,4'-dinonyl-2,2'-bipyridine (hereinafter referred to as diNbip) (PEGMA / EBIB / CuBr(I) / CuBr(II) / diNbip = 200,000 / 1 / 648 / 72 / 1440 (molar ratio)), and 50 parts by mass of anisole were added to a fluorine-containing solution. The silicon wafer with the polymerization initiator groups introduced and a DSC pan were placed in a resin container. The container was sealed, covered with an aluminum bag, and placed in a high-pressure reactor where a polymerization reaction was carried out at 400 MPa and 60°C for 4 hours. After the polymerization reaction was completed, the silicon wafer and DSC pan were removed from the container and washed with tetrahydrofuran using a shaker. This was followed by drying, forming a brush-like polymer chain assembly (polymer brush layer) consisting of multiple polymer chains on the silicon wafer surface, yielding the specimen for Example 1. The thickness of the obtained specimen was measured using an atomic force microscope in both a dry and water-immersed state. The results showed that the mass ratio of water was 50 parts by mass when the mass of polymer chains contained in the layer containing polymer chain assemblies was 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 1097 nm, a number-average molecular weight of 6.65 million, a molecular weight distribution index (PDI) of 1.43, a polymer polymerization rate of 3%, and a polymer chain density of 0.12 chains / nm. 2The surface occupancy of the polymer chains was 0.33. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using dimethylformamide containing 10 mM lithium bromide as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 Measurement was performed by H-NMR. 0.03 mg of water was added to the sample with polymer chains fixed to the DSC pan obtained, and differential scanning calorimetry was performed, confirming that water was retained in liquid form within the layer containing the polymer chain aggregates even at -18°C.

[0113] Example 2 A test specimen was obtained in the same manner as in Example 1, except that when immobilizing the initiating group, BPM was changed to BPM / acetoxypropyltrimethoxysilane (APTMS) = 75 / 25 (molar ratio). The thickness of the obtained specimen was measured using an atomic force microscope in both a dry state and when immersed in water. The results showed that the mass ratio of water was 50 parts by mass when the mass of polymer chains contained in the layer containing polymer chain assemblies was 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 737 nm, a number-average molecular weight of 6.65 million, a molecular weight distribution index (PDI) of 1.43, a polymer polymerization rate of 3%, and a polymer chain density of 0.08 chains / nm. 2 The surface occupancy of the polymer chains was 0.22. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using dimethylformamide containing 10 mM lithium bromide as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 Measurement was performed by H-NMR. 0.03 mg of water was added to the sample with polymer chains fixed to the DSC pan obtained, and differential scanning calorimetry was performed, confirming that water was retained in liquid form within the layer containing the polymer chain aggregates even at -18°C.

[0114] Example 3 A test specimen was obtained in the same manner as in Example 1, except that when immobilizing the initiating group, BPM was changed to BPM / APTMS=50 / 50 (molar ratio). The thickness of the obtained specimen was measured using an atomic force microscope in both a dry state and when immersed in water. The results showed that the mass ratio of water was 50 parts by mass when the mass of polymer chains contained in the layer containing polymer chain assemblies was 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 504 nm, a number-average molecular weight of 6.65 million, a molecular weight distribution index (PDI) of 1.43, a polymer polymerization rate of 3%, and a polymer chain density of 0.05 chains / nm. 2 The surface occupancy of the polymer chains was 0.14. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using dimethylformamide containing 10 mM lithium bromide as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 Measurement was performed by H-NMR. 0.03 mg of water was added to the sample with polymer chains fixed to the DSC pan obtained, and differential scanning calorimetry was performed, confirming that water was retained in liquid form within the layer containing the polymer chain aggregates even at -18°C.

[0115] Example 4 A test specimen was obtained in the same manner as in Example 1, except that when immobilizing the initiating group, BPM was changed to BPM / APTMS=25 / 75 (molar ratio). The thickness of the obtained specimen was measured using an atomic force microscope in both a dry and water-immersed state. The results showed that the mass ratio of water was 50 parts by mass, assuming 100 parts by mass of polymer chains contained in the layer containing polymer chain assemblies. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 314 nm, a number-average molecular weight of 6.55 million, a molecular weight distribution index (PDI) of 1.46, a polymer polymerization rate of 4%, and a polymer chain density of 0.03 chains / nm. 2The surface occupancy of the polymer chains was 0.09. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using dimethylformamide containing 10 mM lithium bromide as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 Measurement was performed by H-NMR. 0.03 mg of water was added to the sample with polymer chains fixed to the DSC pan obtained, and differential scanning calorimetry was performed, confirming that water was retained in liquid form within the layer containing the polymer chain aggregates even at -18°C.

[0116] Example 5 A test specimen was obtained in the same manner as in Example 1, except that PEGMA was replaced with SLMA (trade name: S-lauryl methacrylate, manufactured by NOF Corporation). The thickness of the resulting specimen was measured using an atomic force microscope in both a dry state and when immersed in PAO10 (polyalphaolefin, hydrocarbon oil, trade name: Durasyn 170 (PAO10), manufactured by INEOS Oligomers). The results showed that the mass ratio of PAO10 was 50 parts by mass, assuming 100 parts by mass of polymer chains contained in the layer containing polymer chain assemblies. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a thickness of 789 nm, a number-average molecular weight of 4.05 million, a molecular weight distribution index (PDI) of 1.11, a polymer polymerization rate of 7%, and a polymer chain density of 0.11 chains / nm. 2 The surface occupancy of the polymer chains was 0.20. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using tetrahydrofuran as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 The results were measured by H-NMR. After the obtained test specimen was immersed in PAO10 overnight at room temperature, the excess was blown off with an Ar blower, and an ice adhesion stress test was carried out. The swelling index of the prepared polymer chain assembly in water was 1.1 or less, and 1H-NMR analysis showed that PAO10 was immiscible with water. The results are shown in Table 1.

[0117] Example 6 Main chain polymerization This compound was synthesized by RAFT polymerization of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). In an argon-purged glove box, a toluene solution of BIEM (3 M), cumyldithiobenzoate (CTA) (30 mM), and azobisisobutyronitrile (AIBN) (6 mM) was prepared and transferred to a Schlenk flask. This solution was then stirred in a 60 °C oil bath for 21 h, then quenched by cooling to 0 °C and purging with air. The resulting solution was 1 The conversion rate was determined by H-NMR analysis. The number average molecular weight (Mn) and polydispersity index (Mw / Mn) were measured using a polymethyl methacrylate (PMMA)-calibrated GPC system. The degree of polymerization (DP) was calculated based on the conversion rate and feed molar ratio of BIEM and CTA. The resulting poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) (PBIEM) was purified by precipitation with methanol and then vacuum dried for 18 hours to obtain a pale pink powder. The Mn was 56100, the Mw / Mn was 1.3, and the degree of polymerization was 400. Side chain polymerization PEGMA was synthesized from PBIEM by atom transfer radical polymerization. In an argon-purged glove box, an anisole solution (20 g) of PBIEM (24 mM), PEGMA (0.72 M), Cu(I)Br (38 mM), Cu(II)Br (9.5 mM), and diNbip (95 mM) containing EBIB (2.4 mM) was prepared and transferred to a Schlenk flask. The solution was then stirred at 65 °C for a predetermined time. After the polymerization process, the solution was diluted with DMF and analyzed using a PMMA-calibrated GPC system. The conversion of PEGMA was 1 It was determined by H-NMR analysis. The conversion rate of PEGMA was 19%, Mn was 235,000, Mw / Mn was 1.3, and the degree of polymerization was 11. ·Film formation method Bottlebrush films were fabricated using radical coupling. Bottlebrushes were dissolved in an anisole solution containing tetrakis(dimethylamino)ethylene (TDAE). Next, using a spin coater (Mikasa Corporation), the bottlebrush solution was spin-coated onto a silicon wafer with BPE ((2-bromo-2-methyl)propionyloxypropyltriethoxysilane) immobilized at 3000 rpm for 30 seconds. A bottlebrush film was also fabricated on a DSC pan by dropping the bottlebrush solution onto the BPE-immobilized DSC pan. The thin film was then crosslinked by heating at 120°C for 2 hours in a vacuum. The thin film was then immersed in toluene for 18 hours to wash and remove any remaining surface materials. The thickness of the resulting specimen was measured using an atomic force microscope in both a dry and water-immersed state. The results showed that the mass ratio of water was 50 parts by mass, assuming 100 parts by mass of polymer chains contained in the layer containing polymer chain assemblies. Subsequent analysis revealed that the thickness of the bottle-brush layer formed on the main chain surface was 200 nm, and the surface occupancy of the polymer chains was 0.3. The thickness of the bottle-brush layer was measured using ellipsometry. 0.03 mg of water was added to the sample with polymer chains fixed to the DSC pan obtained, and differential scanning calorimetry was performed, confirming that water was retained in liquid form within the layer containing the polymer chain aggregates even at -18°C. The measurement results are shown in Table 1.

[0118] (Comparative Example 1) A test specimen was obtained in the same manner as in Example 1, except that when immobilizing the initiating group, BPM was changed to BPM / APTMS=10 / 90 (molar ratio). The film thickness of the obtained specimen was measured using an atomic force microscope in both a dry state and when immersed in water. The results showed that the mass ratio of water was 50 parts by mass when the mass of polymer chains contained in the layer containing polymer chain assemblies was 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 118 nm, a number-average molecular weight of 6.55 million, a molecular weight distribution index (PDI) of 1.46, a polymer polymerization rate of 4%, and a polymer chain density of 0.01 chains / nm. 2The surface occupancy of the polymer chains was 0.04. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using dimethylformamide containing 10 mM lithium bromide as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 Measurement was performed by H-NMR.

[0119] (Comparative Example 2) A test specimen was obtained in the same manner as in Example 1, except that when immobilizing the initiating group, BPM was changed to BPM / APTMS=5 / 95 (molar ratio). The thickness of the obtained specimen was measured using an atomic force microscope in both a dry and water-immersed state. The results showed that the mass ratio of water was 50 parts by mass, assuming 100 parts by mass of polymer chains contained in the layer containing polymer chain assemblies. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a thickness of 80 nm, a number-average molecular weight of 6.55 million, a molecular weight distribution index (PDI) of 1.46, a polymer polymerization rate of 4%, and a polymer chain density of 0.01 chains / nm. 2 The surface occupancy of the polymer chains was 0.02. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using dimethylformamide containing 10 mM lithium bromide as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 Measurement was performed by H-NMR.

[0120] (Comparative Example 3) A test specimen was obtained in the same manner as in Example 1, except that PEGMA was replaced with methyl methacrylate (MMA). The film thickness of the obtained test specimen was measured using an atomic force microscope in a dry state and when immersed in N-(2-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (MEMP-TFSI) (ionic liquid) (Kanto Chemical Co., Inc.). The results showed that the mass ratio of MEMP-TFSI was 50 parts by mass, assuming that the polymer chains contained in the layer containing the polymer chain aggregates were 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 1,030 nm, a number-average molecular weight of 2.18 million, a molecular weight distribution index (PDI) of 1.26, a polymer polymerization rate of 9%, and a polymer chain density of 0.34 chains / nm 2 The surface occupancy of the polymer chains was 0.19. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using tetrahydrofuran as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 The results were measured by H-NMR. After immersing the obtained specimen in MEMP-TFSI, the excess was blown off with an Ar blower, and an ice adhesion stress test was carried out. The swelling index of the prepared polymer chain assembly in water was 1.1 or less, 1 H-NMR analysis showed that MEMP-TFSI was miscible with water. The measurement results are shown in Table 1.

[0121] Comparative Example 4 A specimen was obtained in the same manner as in Comparative Example 3, except that MMA was replaced with SLMA. The thickness of the obtained specimen was measured using an atomic force microscope in a dry state and in a state immersed in MEMP-TFSI. The results showed that the mass ratio of MEMP-TFSI was 50 parts by mass, assuming that the polymer chains contained in the layer containing polymer chain assemblies were 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a thickness of 789 nm, a number-average molecular weight of 4.05 million, a molecular weight distribution index (PDI) of 1.11, a polymer polymerization rate of 7%, and a polymer chain density of 0.11 chains / nm. 2The surface occupancy of the polymer chains was 0.20. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using tetrahydrofuran as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 The results were measured by H-NMR. After immersing the obtained specimen in MEMP-TFSI, the excess was blown off with an Ar blower, and the ice adhesion stress test was carried out. The swelling index of the prepared polymer chain assembly in water was 1.1 or less, 1 H-NMR analysis showed that MEMP-TFSI was miscible with water. The results are shown in Table 1.

[0122] (Comparative Example 5) A specimen was obtained in the same manner as in Example 1, except that when immobilizing the initiator group, BPM was changed to BPM / APTMS = 5 / 95 (molar ratio) and PEGMA was changed to SLMA. The film thickness of the obtained specimen was measured using an atomic force microscope in a dry state and when immersed in PAO10. The results showed that the mass ratio of PAO10 was 50 parts by mass when the mass of the polymer chains contained in the layer containing the polymer chain aggregates was 100 parts by mass. Subsequent analysis revealed that the polymer brush layer formed on the silicon wafer surface had a film thickness of 21 nm, a number-average molecular weight of 3.8 million, a molecular weight distribution index (PDI) of 1.12, a polymer polymerization rate of 7%, and a polymer chain density of 0.003 chains / nm. 2 The surface occupancy of the polymer chains was 0.01. The film thickness of the polymer brush layer was measured by ellipsometry. The number average molecular weight and molecular weight distribution index of the polymer brush layer were calculated by gel permeation chromatography using tetrahydrofuran as the developing solvent and a multi-angle light scattering detector as the detector. The polymer polymerization rate was 1 The results were measured by H-NMR. After immersing the obtained test specimen in PAO10, the excess was blown off with an Ar blower, and an ice adhesion stress test was carried out. The swelling index of the prepared polymer chain assembly in water was 1.1 or less, and 1 H-NMR analysis showed that PAO10 was immiscible with water. The results are shown in Table 1.

[0123] [evaluation] The members obtained in the above examples were subjected to the following measurements.

[0124] (Surface occupancy) Calculated using the method described above.

[0125] (film thickness of layer containing polymer chain aggregates) Measurements were made at room temperature using a spectroscopic ellipsometer (MASS-105, manufactured by Five Labs). Optical constants were measured using files created using each test specimen according to the manufacturer's procedures.

[0126] (Icing stress) The components obtained in the examples and comparative examples were placed on a microscope-use cooling stage (manufactured by Japan High Tech Co., Ltd.) and ice adhesion stress measurements were performed. Ice pillars were created by pouring 60 μL of pure water into an aluminum cylinder (inner diameter 6 mm) with silicone grease applied to the edges, cooling it to -20°C at a rate of 5°C / min, and holding it there for 30 minutes. The stage temperature was then raised to the measurement temperature at a rate of 5°C / min and held there for 30 minutes before the test. The L-shaped jig attached to the stage was set to push against the aluminum cylinder as the stage moved. The ice adhesion stress was calculated from the load applied to the load cell of the stage when the ice pillar broke off (Figure 1). The stage movement speed was 10 mm / min.

[0127] (Outdoor exposure evaluation) The members obtained in the examples and comparative examples were installed at an inclination angle of 30 degrees in an outdoor exposure field in Watatsu, Kitahiroshima City, Hokkaido, during the winter (November 2021 to March 2022). The amount of snow adhering to the members was visually evaluated at any time, approximately once a month, and evaluated comprehensively as follows: ◎: Almost no adhesion 〇: No adhesion on more than half △: Over half of the surface is attached ×: Fully adhered

[0128] Table 1

Claims

1. a layer including a brush-like polymer chain assembly composed of a plurality of polymer chains fixed to a substrate; the layer containing the polymer chain assembly holds a liquid substance, A member for suppressing ice nucleation or ice accretion, having an ice accretion stress of 150 kPa or less at -18°C.

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

3. 3. The member according to claim 1, wherein the polymer chain assembly does not swell in water, and the liquid substance is immiscible with water.

4. the substrate is a carrier made of a material different from the polymer chain assembly, 3. The member according to claim 1, wherein the surface occupancy of the polymer chains on the surface of the substrate is 0.08 to 0.

65.

5. the member has a bottle-brush structure in which the plurality of polymer chains are bonded as side chains to a polymer chain that is the base material, 3. The member according to claim 1, wherein the surface occupancy of the side chains is 0.08 to 0.65.

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