JP2016199614A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating technique that can reduce ice deposition force onto a surface.SOLUTION: A coating composition comprises antifreeze polysaccharides.SELECTED DRAWING: None

Description

  The present invention relates to a coating composition, a coating method, a coated specimen, and the like. The coating of the present invention can reduce ice adhesion to the coating surface.

  Objects that can be used at relatively low temperatures, such as airplanes, antennas, electric wires, and trains, may be coated to prevent ice adhesion to the surface. Conventionally, it is usually coated with a water-repellent material and the coating surface is made uneven to create a certain surface roughness, thereby reducing the contact area between ice or water and the coating surface, thereby reducing ice adhesion (Non-Patent Documents 1 to 5).

  However, when pressure is applied in the direction perpendicular to the surface of the uneven structure, water enters the uneven structure. When ice is formed in this state, the ice strongly adheres to the surface by the anchor effect. In addition, the uneven structure has a problem that the coating surface becomes brittle and the sustainability of the coating effect is lowered. For this reason, development of a new coating technology that can reduce ice adhesion to the surface is required.

  On the other hand, antifreeze polysaccharides are natural polysaccharides having a function of inhibiting the growth of ice crystals, and were found from polysaccharides constituting the cell walls of fungi such as enokitake (Patent Document 1). Based on this function, antifreeze polysaccharides are used to prevent quality degradation due to freezing storage of foods. In addition, since antifreeze polysaccharides are excellent in heat resistance and acid resistance, they can also be used as quality improvers such as frozen fried foods and frozen fried foods.

International Publication No. 2012/026339 Special table 2008-529484 JP-T 2009-511689

“A New Surface Coating for Prevention of Icing on Airfoils”, S. Kimura, A. Sakabe, SAE International Technical Paper 2007-01-3315, 2007. “Hydrophobic Coating Study for Anti-icing Aircraft”, Morita, K., Okamoto, K., SAE International Technical Paper 2011-38-0010, 2011. "Study on snow accretion prevention technology (1st report)", Mitsunori Yoshida, Hokkaido Industrial Research Institute Report No.292, 1993. “Capillarity and Wetting Phenomena”, Pierre-Gilles de Gennes, Francoise Brochard-Wyart, David Quere, Springer “Characterizations of Functions of Biological Materials Having Controlling-Ability Against Ice Crystal”, H, Kawahara, Advanced Topics on Crystal Growth, Chapter 5, INTECH open science, 2013.

  This invention makes it a subject to provide the coating technique which can reduce the ice adhesion force to the surface. Furthermore, another object of the present invention is to provide a coating technique that can reduce ice adhesion to the surface without depending on the uneven structure.

  As a result of intensive studies in view of the above problems, the present inventors have found that the adhesion of ice to the surface can be reduced by coating with antifreeze polysaccharide. It has also been found that this effect is exhibited regardless of the uneven structure on the coating surface. As a result of further research based on these findings, the present invention was completed.

  That is, the present invention includes the following aspects.

Item 1. A coating composition containing an antifreeze polysaccharide.
Item 2. Item 4. The composition according to Item 1, further comprising hydrophobin.
Item 3. Item 3. The composition according to Item 1 or 2, wherein the antifreeze polysaccharide is a fungus-derived purified antifreeze polysaccharide.
Item 4. Item 4. The composition according to any one of Items 1 to 3, wherein the solvent is a liquid composition, and the Snyder polarity parameter of the solvent is 2.5 to 5.5.
Item 5. Item 5. The composition according to Item 4, wherein the solvent is at least one selected from the group consisting of chloromethane, dichloromethane, 2-propanol, tetrahydrofuran, n-propanol, chloroform, ethanol, and ethyl acetate.
Item 6. Item 6. The composition according to any one of Items 1 to 5, further comprising a binder.
Item 7. Item 7. The composition according to Item 6, wherein the binder is a moisture curable binder.
Item 8. Item 8. A coating method comprising contacting the composition according to any one of Items 1 to 7 with a part or all of the surface of a test object.
Item 9. A test object, wherein a part or all of the surface is coated with the composition according to any one of Items 1 to 7.

  According to the coating technique of the present invention, it is possible to reduce ice adhesion to the surface. As a result, even if the water adhering to the surface freezes or ice adheres due to snowfall or the like, it becomes easier to peel off due to wind or the like, and the work of removing the adhering ice becomes easier.

According to the coating technique of the present invention, without forming an uneven structure on the coating surface,
Ice adhesion can be reduced. For this reason, it is possible to solve the problem when the coating surface has an uneven structure, that is, the problem that ice can strongly adhere to the surface due to the anchor effect and the problem that the coating surface becomes brittle.

  Further, since the antifreeze polysaccharide is a natural polysaccharide, even if the coating film peels off and diffuses into the natural environment, it is considered that the adverse effect on the natural environment is low.

The schematic diagram of the load apparatus used for the measurement test (Example 3) of an ice adhesion force, and the coating board set to this in the state to which the ice adhered was shown. The measurement test result of ice adhesion force is shown. The upper row shows the results when the freezing temperature is −4 ° C., and the reduction shows the results when the freezing temperature is −8 ° C. A vertical axis | shaft shows the load pressure (= ice adhesion force) at the time of ice peeling.

1. Coating composition TECHNICAL FIELD This invention relates to the coating composition (it may show as "the coating composition of this invention" in this specification) containing antifreeze polysaccharide. This will be described below.

  Antifreeze polysaccharides are natural polysaccharides having a function of inhibiting the growth of ice crystals, and are components found from polysaccharides constituting the cell walls of fungi such as enokitake (Patent Document 1). In the present specification, the term “polysaccharide” generally refers to a polymer in which 10 or more monosaccharides are polymerized linearly or branched by glycosidic bonds.

  The antifreeze polysaccharide is not particularly limited, but for example, a polysaccharide containing at least one monosaccharide selected from the group consisting of galactose, mannose, xylose, glucose, and rhamnose, preferably two or more A polysaccharide containing a monosaccharide, more preferably a polysaccharide containing xylose and mannose, and more preferably a xylomannan.

  Xylomannan is a general term for heteropolysaccharides in which one molecule of xylose is bonded as a side chain to a mannan main chain composed of α-1,3-mannose via a 1,4-bond. However, xylomannan is not limited to those composed only of mannose and xylose, but may have other sugars as side chains in addition to xylose.

  The composition ratio of mannose and xylose constituting xylomannan is not particularly limited. For example, mannose is 1.5 to 2.5 mol, preferably 1.7 mol to 2.3 mol, more preferably 1 mol of xylose. It can be from 1.9 mol to 2.1 mol, more preferably about 2 mol.

  The molecular weight of the antifreeze polysaccharide is not particularly limited, but may be, for example, 100,000 to 1,000,000 as an average molecular weight measured by gel filtration chromatography. The lower limit of the average molecular weight is preferably 150,000, more preferably 200,000, still more preferably 240,000, and still more preferably 280,000. The upper limit of the average molecular weight is preferably 500,000, more preferably 400,000, still more preferably 370,000, and still more preferably 340,000.

  As the antifreeze polysaccharide, for example, one chemically synthesized according to a known method may be used, but preferably a purified product obtained by purifying the antifreeze polysaccharide from a fungus according to a known method (antifreeze derived from a fungus). Polysaccharide purified product) can be used.

  Among fungi, basidiomycetes are preferable. Examples of basidiomycetes include those belonging to the order Agaric. Examples of basidiomycetes belonging to the order Agaricaceae include, for example, Numerigidae (goattake, etc.), Kishimeji (Kishimeji, Murasakimeji, Oshiroi-shimeji, Kakumino-shimeji, Shakashimeji, Harushimeji, Hatake-shimeji, Buna-shimeji, Hon-shimeji, Ohoriraitake, Hagihiratake, Sugihiratake , Fox, bamboo shoots, mushrooms, mushrooms, white mushrooms, shiitake mushrooms, enokitake, etc. Etc.), Fusentaceae (such as Astragalus), Iguchi (Yamatake, etc.), Agaricaceae (such as Aitake), Sarnochoke (such as Maitake), and Oyster (such as Eringi). Among these, preferred are those belonging to the family Asteraceae, oyster mushrooms, Moegiaceae and the like, more preferably those belonging to the family Asteraceae, and more preferably enokitake.

  When basidiomycetes are used as the organism containing the antifreeze polysaccharide, the culture is preferably performed at a low temperature. By using basidiomycetes obtained by culturing basidiomycetes at a relatively low temperature (cold acclimation) as an extraction source, it is possible to obtain antifreeze polysaccharides more efficiently. As culture | cultivation temperature, 25 degrees C or less is preferable and 20 degrees C or less is more preferable, for example. On the other hand, if the temperature is lower than the freezing point, the liquid medium may freeze.

  The culture period is not particularly limited, but it is preferably 3 days or more, more preferably 1 week or more, further preferably 2 weeks or more, particularly preferably 1 month or more. The upper limit of the culture period is not particularly limited, but may be until the basidiomycete becomes confluent or the concentration of the ice crystallization inhibitor in the medium does not increase any more. For example, preferably 6 Months or less, more preferably 5 months or less, even more preferably 4 months or less, and particularly preferably 3 months or less.

  Purification of antifreeze polysaccharides from fungi can be performed according to known methods. For example, it is known that antifreeze polysaccharides can hardly be extracted with hot water, but can be extracted by heat treatment in an alkaline aqueous solution (Patent Document 1). Based on this finding, as the above-mentioned “purified product of antifreeze polysaccharide derived from fungi”, for example, a fungal hot water extraction residue, a fungal hot alkali extract and the like can be used. Among these, a fungal hot water extraction residue is preferable. In addition, it is known that the hydrophobin described later is also present in the cell wall of the fungus and cannot be extracted with hot water (Patent Documents 2 to 3). It is preferable because it can include a phobin.

  The fungal hot water extraction residue can be obtained, for example, by collecting the residue after the hot water extraction treatment of the fungus.

  The fungus is preferably degreased before the hot water extraction treatment. Degreasing can be performed by leaving fungi (preferably fungal fruit bodies) in an organic solvent such as hexane. The degreasing time can be appropriately adjusted depending on the temperature, and can be, for example, about 6 to 24 hours at room temperature. After the degreasing treatment, it is preferable to remove the supernatant by centrifugation, filtration, etc., and then subject to the next treatment.

  The fungus is preferably acid-treated before the hot water extraction treatment. The purpose of the acid treatment is to remove acid-soluble components in the fungus, and so long as the acid treatment conditions are not particularly limited, it can be performed according to a known method. The acid treatment can be performed, for example, by suspending a fungus (preferably a residue obtained after the degreasing treatment of the fungus) in an acid aqueous solution (preferably a weak acid aqueous solution) such as acetic acid and citric acid. Although pH of acid aqueous solution is not specifically limited, For example, pH 1.0-3.0, Preferably it can be about 1.0-2.0. After the acid treatment, the supernatant is preferably removed by centrifugation, filtration or the like, and then subjected to the next treatment.

  The fungus may be subjected to alcohol treatment before hot water extraction treatment (preferably after degreasing and acid treatment and before hot water extraction treatment). Although it does not specifically limit as alcohol, For example, ethanol, methanol, 1-propanol etc., Preferably ethanol is mentioned. The temperature of the alcohol treatment is preferably a low temperature, and can be, for example, about −80 to −10 ° C. After the alcohol treatment, it is preferable to remove the supernatant by centrifugation, filtration, etc., and then subject to the next treatment.

  The hot water extraction treatment can be performed by immersing the fungus in high-temperature water and stirring as necessary. The temperature of water can be 80 degreeC or more, for example, Preferably it is 90 degreeC or more, More preferably, it is 95 degreeC or more, More preferably, it can be 99 degreeC or more. Although processing time is not specifically limited, For example, it is 10 to 120 minutes, Preferably it can be about 30 to 90 minutes. After the hot water extraction treatment, the fungal hot water extraction residue can be obtained by removing the supernatant by centrifugation, filtration or the like.

  When the particle size of the fungal hot water extraction residue is too large, it is difficult to uniformly coat the surface, so that it is desirable to grind as necessary. The particle size of the hot water extraction residue can be, for example, 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less.

  The fungal hot alkali extract can be obtained, for example, by subjecting a fungus to heat extraction treatment in an alkaline aqueous solution.

  The fungus may be subjected to the hot water extraction treatment before the heat extraction treatment in the alkaline aqueous solution. By doing in this way, hot water soluble components other than an antifreeze polysaccharide can be removed.

  The alkaline substance used for the preparation of the alkaline aqueous solution is not particularly limited, but for example, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium polyphosphate, trisodium citrate, sodium bicarbonate, sodium acetate, Sodium pyrophosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, trisodium phosphate, tripotassium phosphate, calcined calcium, etc. can be used, and when used, they can be used alone or as a mixture of two or more. it can.

  What is necessary is just to adjust the density | concentration of aqueous alkali solution suitably. The lower limit is, for example, 0.1 w / v%, preferably 1.0 w / v%, more preferably 2.0 w / v%, still more preferably 5.0 w from the viewpoint that the antifreeze polysaccharide can be extracted more efficiently. / V%, more preferably 10.0 w / v%, even more preferably 15.0 w / v%, particularly preferably 20.0 w / v%. Further, the upper limit can be, for example, 50 w / v%, preferably 30 w / v%, more preferably 25 w / v% from the viewpoint of cost and safety.

  The temperature of the heat extraction treatment is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, further preferably 90 ° C. or higher, and most preferably about 100 ° C. As a method of the heat extraction treatment, for example, after adding an alkaline aqueous solution, it may be extracted while being heated to a predetermined temperature, or an alkaline aqueous solution heated in advance to a predetermined temperature is added and kept warm. You may extract by.

  What is necessary is just to adjust the time of heat extraction process suitably according to temperature, the density | concentration of an alkaline substance, etc. The time for the heat extraction treatment can be, for example, about 0.5 to 8 hours, preferably 1 to 5 hours, and more preferably about 2 to 3 hours.

  The extraction may be performed once, but from the viewpoint of obtaining more antifreeze polysaccharides, the same extraction process may be repeated once or a plurality of times for the residue obtained after extraction once. .

  The extract obtained as described above may be used as it is, or may be used after removing an alkaline substance by a known method such as neutralization or dialysis. Moreover, you may refine | purify further as needed. For example, contaminant components may be removed by suitably combining decantation, filtration, centrifugation, and the like. In addition, for example, salt precipitation, precipitation with an organic solvent, affinity chromatography, ion exchange column chromatography, gel filtration, purification by binding to ice using a low-speed cooling device, and concentration by dialysis or ultrafiltration are suitable. You may carry out in combination.

  The content of the antifreeze polysaccharide is not particularly limited as long as the ice adhesion to the surface can be reduced. For example, 0.001 to 20% by mass, preferably 100% by mass with respect to 100% by mass of the coating composition of the present invention. May be from 0.01 to 10% by weight, more preferably from 0.1 to 10% by weight.

  An antifreeze polysaccharide may be used individually by 1 type, and may be used in combination of 2 or more type.

  The coating composition of the present invention preferably contains hydrophobin. By containing hydrophobin, it is considered that the antifreeze polysaccharide can be more firmly retained in the coating film.

  Hydrophobin is a protein rich in hydrophobic amino acids that is secreted by fungi such as filamentous fungi, and has a very characteristic pattern of eight conserved cysteine residues. These residues form four intramolecular disulfide bridges.

  Examples of organisms derived from hydrophobin include basidiomycetes. Examples of basidiomycetes include those belonging to the order Agaric. Examples of basidiomycetes belonging to the order Agaricaceae include, for example, Numerigidae (goattake, etc.), Kishimeji (Kishimeji, Murasakimeji, Oshiroi-shimeji, Kakumino-shimeji, Shakashimeji, Harushimeji, Hatake-shimeji, Buna-shimeji, Hon-shimeji, Ohoriraitake, Hagihiratake, Sugihiratake , Fox, bamboo shoots, mushrooms, mushrooms, white mushrooms, shiitake mushrooms, enokitake, etc. Etc.), Fusentaceae (such as Astragalus), Iguchi (Yamatake, etc.), Agaricaceae (such as Aitake), Sarnochoke (such as Maitake), and Oyster (such as Eringi). Among these, preferred are those belonging to the family Asteraceae, oyster mushrooms, Moegiaceae and the like, more preferably those belonging to the family Asteraceae, and more preferably enokitake.

Specific examples of the hydrophobin include the following. Here, the name of the organism and the Accession No. of NCBI (National Center for Biotechnology Information) protein database (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Protein) are shown respectively. . Many hydrophobins are known besides these, and the hydrophobin used in the present invention is not limited to the above.
Trichoderma reesei P52754, P79073
Gibberella moniliformis AAO16867-16870
Agaricus bisporus CAA61530
Pleurotus ostreatus CAD12829-12834
Schizophyllum commune CAA07545
Hipocrea jecorina CAA92208
Cladosporium fulvum CAA67187, CAB39309-39312
Aspergillus fumigatus AAC13524
Flammulina velutipes BAD08615
Lentinula edodes AAG00900-00901
Pisolithus tinctorius AAC49307-49308
Hypocrea lixii CAA72539
Neosartorya aureola AAC13528
Aspergillus duricaulis AAC13522
Dictyonema glabratum CAC86002, 86005, 86006
Among these, enokitake mushroom-derived hydrophobin (BAD08615, the amino acid sequence is represented by SEQ ID NO: 1) is preferable.

  Hydrophobin has 8 cysteines (amino acids 34, 44, 45, 81, 94, 100, 101, and 114 in SEQ ID NO: 1) conserved, and the proportion of hydrophobic amino acids (hydrophobic) The number of amino acids / total number of amino acids) is relatively high (about 62.8% in SEQ ID NO: 1), and hydrophobins derived from any organism may be used as long as this is the case.

  Hydrophobins are natural hydrophobins as long as the above characteristics (characteristics that eight cysteine residues are conserved and characteristics that a relatively high proportion of hydrophobic amino acids are retained) are retained. One or a plurality (for example, 2 to 50, preferably 2 to 30, more preferably 2 to 10, more preferably 2 to 5) of amino acids may be deleted, substituted, added, inserted, or the like. The proportion of hydrophobic amino acids can be preferably 50% or more, more preferably 55% or more, and even more preferably 60% or more.

  As hydrophobins, those chemically synthesized according to known methods may be used, those obtained as recombinant proteins according to known methods may be used, and hydrophobins may be purified from fungi according to known methods. The purified product obtained in this way may be used.

  Purification of hydrophobin from fungi can be performed according to a known method. For example, as described above, it is known that hydrophobin is present in fungal cell walls and cannot be extracted with hot water (Patent Documents 2 to 3). Based on this knowledge, for example, hydrophobin can be obtained by recovering a residue (fungal hot water extraction residue) after hot water extraction treatment of the fungus. Various conditions for the hot water extraction treatment are the same as the hot water extraction treatment in the purification of the antifreeze polysaccharide. As described above, it is known that antifreeze polysaccharides are also present in fungal cell walls and cannot be extracted with hot water (Patent Document 1). Frozen polysaccharides can also be included, which is preferable.

  Although content of hydrophobin is not specifically limited, For example, 0.001-10 mass% with respect to 100 mass% of coating compositions of this invention, Preferably it is 0.01-5 mass%, More preferably, it is 0. .1-5% by mass.

  A hydrophobin may be used individually by 1 type, and may be used in combination of 2 or more type.

  The coating composition of the present invention may be a solid composition such as a powder, but is preferably a liquid composition from the viewpoint of ease of coating treatment.

  The solvent in this case is not particularly limited as long as it is usually used in a coating composition. The solvent is preferably a Snyder polarity parameter of 2.5 to 5.5, more preferably 2.8 to 5 from the viewpoint that the antifreeze polysaccharide (particularly fungal hot water extraction residue) can be more uniformly dispersed. A solvent that is 0.0, more preferably 2.9 to 4.5, and still more preferably 3.0 to 4.3. Note that “more uniformly dispersed” means that there is less precipitate when the antifreeze polysaccharide and the solvent are stirred and allowed to stand for a certain period of time and then visually observed. Specific examples of the solvent (the values in parentheses on the right side of the solvent are Snyder polar parameters) include chloromethane (3.1), dichloromethane (3.5), 2-propanol (3.9), tetrahydrofuran (4.0) , N-propanol (4.0), chloroform (4.1), ethanol (4.3), ethyl acetate (4.4), methyl ethyl ketone (4.7), dioxane (4.8), acetone (5. 1), methanol (5.1) and the like.

  Although content of a solvent is not specifically limited, For example, it is 50-99 mass% with respect to 100 mass% of coating compositions of this invention, Preferably it is 70-95 mass%, More preferably, it is 80-90 mass%. be able to.

  A solvent may be used individually by 1 type and may be used in combination of 2 or more type.

  The coating composition of the present invention preferably contains a binder. By including the binder, the coating film can be more firmly attached to the surface. Moreover, when a binder is included, a curing catalyst can also be included as necessary.

  As the binder, known binders can be widely used for surface coating, preferably used for surface coating of objects used outdoors. Specific examples include a fluororesin, a silica-based special binder, and a moisture curable silicone oligomer. Among these, a moisture curable silicone oligomer is preferable. By using the moisture curable silicone oligomer, it is possible to improve water resistance, moisture resistance, weather resistance and the like.

The moisture curable silicone oligomer is, for example, a low molecular weight silicone alkoxy oligomer having an alkoxysilyl group at the molecular end, and cured at room temperature by crosslinking of the alkoxysilyl group in the presence of a curing catalyst described later. It is done. Such a moisture-curable silicone oligomer is represented by the following general formula (1), for example.
R ¹ _n Si (OR ² ) _4-n (1)
(In General Formula (1), R ¹ represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R ² represents an alkyl group, and n represents an integer of 0 to 3. ¹ and R ² may be the same or different from each other.
Examples of R ¹ include a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group.

In R ¹ , examples of the unsubstituted monovalent hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group.

  Examples of the alkyl group include methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, iso-pentyl, sec-pentyl, hexyl, heptyl, n-octyl, isooctyl. Alkyl groups having 1 to 18 carbon atoms such as 2-ethylhexyl, nonyl, decyl, isodecyl, dodecyl, tetradecyl, hexadecyl, and octadecyl.

  Examples of the cycloalkyl group include cycloalkyl groups having 3 to 8 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

  Examples of the aryl group include aryl groups having 6 to 14 carbon atoms such as phenyl, tolyl, xylyl, biphenyl, naphthyl, anthryl, and phenanthryl.

  Examples of the aralkyl group include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, diphenylmethyl, o, m or p-methylbenzyl, o, m or Examples include aralkyl groups having 7 to 13 carbon atoms such as p-ethylbenzyl.

In R ¹ , examples of the substituted monovalent hydrocarbon group include those obtained by substituting the above-described unsubstituted monovalent hydrocarbon group with a substituent. Examples of such a substituent include a halogen atom. (For example, chlorine, fluorine, bromine and iodine), hydroxyl, cyano, amino, carboxyl and the like. These substituents may be the same or different from each other. For example, 1 to 3 substituents may be substituted.

R ¹ preferably includes at least a monovalent hydrocarbon group having 4 or more carbon atoms, and more specifically, R ¹ is an unsubstituted monovalent hydrocarbon group having ¹ to 3 carbon atoms. A combination of a hydrocarbon group and an unsubstituted monovalent hydrocarbon group having 4 or more carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms and an aryl group having 6 to 14 carbon atoms. It is a combination.

R ² includes an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl and the like. .

R ¹ and R ² are independent of each other and may be the same or different from each other.

  n shows the integer of 0-3, for example, Preferably, 1 or 2 is shown.

  Specific examples of such alkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, and dimethyldimethoxysilane. , Phenyltrimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, or a mixture thereof.

  A partially hydrolyzed condensate of an alkoxysilane compound means that water is added to the above alkoxysilane compound and heated while stirring in the presence of a catalyst to cause partial hydrolysis and condensation. Is obtained.

  The moisture curable silicone oligomer may be used alone or in combination of two or more.

  The curing catalyst is not particularly limited as long as it is a catalyst capable of curing a moisture curable silicone oligomer. For example, organotin compounds such as dibutyltin diacetate, dibutyltin dioctylate and dibutyltin dilaurate, for example, aluminum tris (acetylacetone) Organic aluminum compounds such as aluminum tris (acetoacetate ethyl) and aluminum diisopropoxy (acetoacetate ethyl), such as zirconium (acetylacetone), zirconium tris (acetylacetone), zirconium tetrakis (ethylene glycol monomethyl ether), zirconium tetrakis (ethylene) Glycol monoethyl ether), zirconium tetrakis (ethylene glycol monobutyl ether) and other organic zirconium compounds For example, organometallic compounds such as organic titanium compounds such as titanium tetrakis (ethylene glycol monomethyl ether), titanium tetrakis (ethylene glycol monoethyl ether), titanium tetrakis (ethylene glycol monobutyl ether), such as hydrochloric acid, nitric acid, sulfuric acid, phosphorus Mineral acids such as acids, organic acids such as formic acid, acetic acid, oxalic acid and trifluoroacetic acid, for example, inorganic bases such as ammonia, sodium hydroxide and potassium hydroxide, and organic bases such as ethylenediamine and alkanolamine Examples of the alkali include amino compounds such as amino-modified silicone, aminosilane, silazane, and amines.

  These curing catalysts may be used alone or in combination of two or more.

  As the moisture curable silicone oligomer, it is preferable to use a commercially available product that contains a curing catalyst in advance. Examples of such commercially available products include X-40-175 (curing catalyst DX-175; containing 5 wt%), X-40-2327 (curing catalyst X-40-2309A; containing 30 wt%), KR- 400 (curing catalyst DX-9740; containing 10% by weight) (above, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

  The content of the binder (when the curing catalyst is included, the combined content of the binder and the curing catalyst) is not particularly limited, but is, for example, 1 to 20% by mass with respect to 100% by mass of the coating composition of the present invention. Preferably it can be 4-15 mass%.

  The coating composition of the present invention may contain other components other than those described above as long as the ice adhesion to the surface can be reduced. Examples of other components include wax-based water repellents.

2. Coating method and coated specimen The present invention comprises contacting the coating composition of the present invention with a part or all of the surface of the specimen (in this specification, “coating treatment”). The present invention relates to a coating method (which may be referred to herein as “the coating method of the present invention”). Furthermore, the present invention also relates to a test object in which a part or all of the surface is coated with the coating composition of the present invention. Hereinafter, these will be described.

  The test object is an object to be coated with the coating composition of the present invention, and is not particularly limited as long as it is an object that can be coated. Preferably, the test object is an object used in an environment where ice can adhere. Specific examples of such objects include vehicles such as airplanes, ships, trains, automobiles, roofs and outer walls of buildings, antennas, electric wires, cold protection equipment, traffic lights, heat exchangers, and the like.

  The contact is not particularly limited as long as the coating composition of the present invention and a part or all of the surface of the test object can be contacted. For example, spraying, application | coating, etc. are mentioned, From a viewpoint that it can contact more simply, Preferably a spray is mentioned.

  The coating composition of the present invention may be brought into contact with the specimen as it is, but may be mixed with another coating composition and then brought into contact with the specimen, and coated with another coating composition. You may make it contact with the processed test object.

  The amount of the coating composition of the present invention to be brought into contact with the test object is not particularly limited as long as it is an amount that can cover part or all of the surface of the test object. For example, it can be about 0.5 to 10 mL, preferably about 1.5 to 5 mL with respect to the surface of 5 cm × 5 cm.

  After the coating treatment, a coating film can be formed on the surface of the test object by performing drying, binder curing treatment or the like as necessary.

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

Example 1: Preparation of antifreeze polysaccharide and hydrophobin-containing basidiomycetous extract It is known that antifreeze polysaccharide and hydrophobin exist in the cell wall of basidiomycete (Patent Documents 1 to 3). Antifreeze polysaccharides can hardly be extracted with hot water, but can be extracted by heat treatment in an alkaline aqueous solution (Patent Document 1). Hydrophobin cannot be extracted with hot water, but can be extracted with trifluoroacetic acid or a surfactant (Patent Documents 2 to 3). Based on these findings, enokitake, a kind of basidiomycete, is extracted with a solvent (hot water) in which antifreeze polysaccharides and hydrophobins are difficult to dissolve, thereby removing residues (basidiomycetes). The hot water extraction residue was used as an antifreeze polysaccharide and hydrophobin-containing extract. Specifically, it was performed as follows.

Enokitake fruit body powder (5 g) was suspended in hexane (200 mL) and allowed to stand at room temperature for 16 hours (degreasing treatment). Centrifugation (7500 × g, 4 ° C., 15 minutes) (HITACHI High Technologies) gave a residue. 1.5 g of the residue was suspended in a mixed solution of 2 mL of 10% acetic acid solution and 20 mL of washing buffer (0.1 MTris-HCl pH 8.0, 10 mM MgSO ₄ , 1 mM PMSF), and then centrifuged (10000 g, 4 ° C. For 15 minutes) to obtain a precipitate. The precipitate was suspended in 20 mL of 10% acetic acid and 10 mM MgSO ₄ solution, and then centrifuged (10000 g, 4 ° C., 15 minutes) to obtain a precipitate. 1.4 g of the precipitate was put in 20 mL of ethanol (−20 ° C.), and centrifuged (10000 g, 4 ° C., 15 minutes) to collect the precipitate (washing treatment). This washing was performed twice in total. The collected precipitate was dried in a draft chamber, and the obtained dried product was immersed in water at 100 ° C. for 60 minutes (hot water treatment). Then, it cooled to normal temperature and centrifuged (10000g, 4 degreeC, 15 minutes), and obtained the deposit. The resulting precipitate is crushed (2700 rpm, 4 minutes) with a pulverizer (multi-bead shocker (product name), Yasui machine (manufacturer)), passed through a sieve having openings of 212 μm, 106 μm, and 53 μm, and a powder having a diameter of about 50 μm or less. Got the body. This powder was used in the following examples as an antifreeze polysaccharide and hydrophobin-containing extract.

Comparative Example 1: Preparation of hydrophobin-containing basidiomycete extract The powder (antifreeze polysaccharide and hydrophobin-containing extract) obtained in Example 1 was prepared using a strongly alkaline aqueous solution (prepared with pH 12 NaOH) or strongly alkaline ionized water. In (Alpha water, Fuji High-Tech Co., Ltd.), extraction was performed at 100 ° C. for 3 hours. The precipitate was collected by centrifugation (7500 g, 4 ° C., 15 minutes). The precipitate was freeze-dried and used in the following examples as a powder (hydrophobin-containing extract) containing no antifreeze polysaccharide.
Example 2: Mixing with a solvent and dispersibility test Glass vials containing 0.01 g of antifreeze polysaccharide and hydrophobin-containing extract (Example 1) and 1 ml of various solvents (Table 1) in equal amounts (volumes) The mixture was stirred for 5 minutes with an ultrasonic cleaner (US-1, manufactured by SND Corporation). After stirring, the glass vial was allowed to stand for 1 hour, and the dispersion state of the antifreeze polysaccharide and the hydrophobin-containing extract (powder) was visually observed and evaluated. The evaluation results are shown in Table 1. Both dichloromethane and 2-propanol were able to disperse the powder almost uniformly, but the powder was more evenly dispersed when 2-propanol was used. Based on this result, 2-propanol was used as a solvent in the following examples.

Example 3: Coating treatment <3-1. Preparation of coating solution>
Antifreeze polysaccharide and hydrophobin-containing extract (Example 1) 0.1 g, moisture curable silicone oligomer (X-40-2327, manufactured by Shin-Etsu Chemical Co., Ltd.) 200 μL, 2-propanol 2.5 mL were mixed, A coating solution was prepared (Coating Solution 1). Furthermore, 0.1 g of a hydrophobin-containing extract (Comparative Example 1), a moisture curable silicone oligomer (X-40-2327, manufactured by Shin-Etsu Chemical Co., Ltd.) 200 μL, and 2-propanol 2.5 mL were mixed to form a coating solution. Was prepared (coating solution 2).

<3-2. Coating processing>
An aluminum plate (50 cm × 50 cm) was coated with acrylic urethane, and the surface was filed (# 800, 1200). Here, the coating solution 1 or 2 was sprayed uniformly. After spraying, the coating film was cured by leaving it in the air for 60 minutes to obtain a coated plate.

<3-3. Surface roughness measurement test>
When the surface roughness of the coating surface of the coating plate obtained in 3-2 above was measured with a non-contact surface roughness meter (: LASER Focus Displacement Meter LT-8105, LT-V201, manufactured by KEYENCE Corporation), RMS It was about 1 to 1.5 (μm).

<3-4. Pencil hardness measurement test>
When the pencil hardness test was performed on the coating surface of the coating plate obtained in 3-2 according to JIS K5600-5-4, the pencil hardness was 4B.

<3-5. Dissolution test in water>
The coating plate obtained in 3-2 above was immersed in distilled water and allowed to stand at room temperature for 2 days. The coating surface was visually observed, and no coating was dissolved.

<3-6. Ice adhesion test>
As test objects, the coated plate obtained in 3-2 above and the aluminum plate adjusted to have the same surface roughness (RMS of about 1 to 1.5 μm) were prepared. A stainless steel ring (inner diameter: 1 inch, height: 1.5 cm) was placed on the coating surface of the coating plate obtained in 3-2 or on an aluminum plate, and the ring was filled with water. This was left at -4 ° C or -8 ° C for 1 hour to freeze the water in the ring. This was set in an ice adhesion tester as shown in FIG. 1, a load was applied to the side surface of the stainless steel ring with a pusher, and the pressure when the ice peeled was measured. This measured value is defined as ice adhesion. This test was performed 10 times, and the average value of the measured pressure values was obtained and graphed (FIG. 2).

  As shown in FIG. 2, the ice adhesion force on the surface coated with the coating solution containing no antifreeze polysaccharide (Coating Solution 2) was the same as or slightly higher than the ice adhesion force on the aluminum plate surface. . On the other hand, the ice adhesion force to the surface coated with the coating solution containing antifreeze polysaccharide (coating solution 1) is coated with the ice adhesion force to the aluminum plate surface and the coating solution not containing antifreeze polysaccharide (coating solution 2). The ice adhesion to the surface was significantly lower. From this result, it was shown that the ice adhesion force on the coating surface can be reduced by coating the antifreeze polysaccharide. Moreover, since the said result is a result in case surface roughness is comparable, it was shown that the antifreeze polysaccharide exists on the surface itself has reduced the ice adhesion force. From this, it is considered that the effect of reducing the ice adhesion force due to the antifreeze polysaccharide is an effect that can be exhibited without creating an uneven structure on the coating surface.

Claims (9)

A coating composition containing an antifreeze polysaccharide. Furthermore, the composition of Claim 1 containing a hydrophobin. The composition according to claim 1 or 2, wherein the antifreeze polysaccharide is a purified antifreeze polysaccharide derived from a fungus. The liquid composition containing a solvent, wherein the Snyder polarity parameter of the solvent is 2.5 to 5.5. The composition according to claim 4, wherein the solvent is at least one selected from the group consisting of chloromethane, dichloromethane, 2-propanol, tetrahydrofuran, n-propanol, chloroform, ethanol, and ethyl acetate. Furthermore, the composition in any one of Claims 1-5 containing a binder. The composition of claim 6, wherein the binder is a moisture curable binder. A coating method comprising bringing the composition according to claim 1 into contact with a part or all of the surface of a test object. A test object in which a part or all of the surface is coated with the composition according to claim 1.