JP-7855806-B2 - Members for suppressing ice nucleus formation, frost formation, or snow and ice accumulation.

Inventors

• 玉本 健
• 松井 徳純
• 三浦 裕佑
• 宇都宮 朗
• 杉田 翼
• 辻井 敬亘
• 松川 公洋
• 黄瀬 雄司
• 大野 工司

Assignees

• 日本ペイント・サーフケミカルズ株式会社
• 日本ペイントコーポレートソリューションズ株式会社
• 国立大学法人京都大学
• 公立大学法人大阪

Dates

Publication Date

20260508

Application Date

20240925

Priority Date

20230925

Claims (7)

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

Description

The present invention relates to a member for suppressing ice nucleus formation, frost formation, or snow accumulation and ice formation. In heat exchangers used in air conditioners and refrigerators, rapid cooling of the air can cause water droplets to adhere to the surface of the cooling components within the heat exchanger, or frost to form, which can reduce heat exchange efficiency. In particular, frost is formed through ice accumulation and the formation and growth of ice nuclei on the surface of the cooling components. As a method to suppress frost formation, a method of forming a resin film on the surface of the components is known, as described in Patent Document 1. Japanese Patent Publication No. 2019-158247 Figure 1 is a schematic diagram illustrating the test method for ice formation stress. The following describes in detail embodiments for carrying out the present invention (hereinafter referred to as "this embodiment"). The present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist. The member of this embodiment is a member for suppressing ice nucleation, suppressing frost formation, or suppressing snow accumulation and ice, having a coating film obtained by applying a coating composition containing a solvent and a polymer. The polymer comprises a graft-type polymer compound (A) having a structural unit represented by the following general formula (1) and a crosslinkable functional group (a), and a crosslinkable polymer compound (B) having two or more reactive functional groups (b) that crosslink with the crosslinkable functional group (a). The content of the crosslinkable polymer compound (B) in the total of 100% by mass of the graft-type polymer compound (A) and the crosslinkable polymer compound (B) is 0.1% by mass or more and less than 50% by mass. This material has an ice formation stress of 150 kPa or less at -18°C. (In the general formula (1) above, R1 represents a hydrogen atom or a methyl group, X represents O or NH, R2 represents any organic group, R3 and R4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an acyl group, and the carbon atoms to which R3 and R4 are bonded are tertiary or quaternary carbon atoms, n represents any number of repeats, and Polymer represents a graft chain containing constituent units derived from at least one graft monomer selected from the group consisting of (meth)acrylic acid monomers, (meth)acrylamide monomers, aromatic vinyl monomers, and (meth)acrylonitrile.) The component of this embodiment has excellent snow accumulation and ice suppression effects, frost formation suppression effects, and ice nucleation suppression effects. Although the detailed reasons for obtaining such effects are not entirely clear, it is presumed that they are due to the following: The component of this embodiment has a coating film obtained by applying a coating composition containing a solvent and a polymer, and the graft-type polymer compound (A) and the crosslinkable polymer compound (B) contained in the coating composition are capable of crosslinking each other. It is presumed that the crosslinking reaction between the graft-type polymer compound (A) and the crosslinkable polymer compound (B) increases the mobility of the graft chains contained in the graft-type polymer compound (A), thereby making it easier to create a supercooled or nonfreezing state. It is presumed that the component of this embodiment has a highly mobile interface with respect to ice, frost, snow, etc., due to the presence of the coating film formed from such a coating composition. Furthermore, it is presumed that the presence of the coating film formed from such a coating composition allows water to undergo thermal motion without freezing even below the freezing point, thus further lowering the freezing temperature of water on the surface of the component. Furthermore, the member of this embodiment is presumed to have an excellent snow and ice accumulation suppression effect because water is less likely to freeze on the member surface, ice, frost, snow, etc. are less likely to form on the member surface, and it has a highly mobile interface with respect to ice, frost, snow, etc. Even if ice, frost, snow, etc. do form on the member surface, they slide off easily and are easily peeled off by external force. Furthermore, since the component of this embodiment can further lower the freezing temperature of water inside or on the surface of the component, it is presumed that it can lower the temperature at which ice nuclei form and thus has an excellent effect in suppressing ice nucleus formation. <Coating composition> In the following, we will first describe the coating composition for forming the coating film that constitutes the component. The coating composition used in this embodiment contains a solvent and a polymer, As a polymer, A graft-type polymer compound (A) comprising a constituent u