JP2017052918A - Antifogging composition and antifogging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antifogging composition which is excellent in antifogging properties, especially antifogging properties under a low-temperature environment and exhibits excellent scratch resistance.SOLUTION: The antifogging composition contains a hydrophobic binder resin and colloidal silica and is characterized in that: (1) the glass transition temperature (Tg) of the hydrophobic binder resin is 0-30°C; (2) the acid value (AV) of the hydrophobic binder resin is 60-300 mg KOH/g; and (3) the glass transition temperature (Tg) and the acid value (AV) of the hydrophobic binder resin satisfy the following expression (I): |(Tg)/(AV)|×100≤30.SELECTED DRAWING: None

Description

  The present invention relates to an antifogging composition and an antifogging film.

  Conventionally, a technique for imparting antifogging properties to products such as films in various fields has been demanded. For example, in the field of agriculture, when cultivating agricultural crops, in order to increase marketability and productivity, vinyl chloride film, special film mainly composed of polyethylene, ethylene-vinyl acetate copolymer and polyolefin resin, etc. House cultivation and tunnel cultivation, in which useful crops are cultivated by coating with agricultural films, are being actively performed.

  The above-mentioned agricultural film has high transparency in order to transmit sunlight, and so-called anti-fog that water droplets attached to the inner surface of the film flow down along the inner surface of the film without falling on the cultivated crop. Property (droplet property) is required.

  An agricultural drip-proof film in which an aqueous acrylic-modified urethane resin coating layer containing colloidal silica particles is provided on one surface of a synthetic resin film has been proposed as an agricultural film exhibiting anti-fogging properties (Patent Document 1). (See claim 1). The coating layer of the agricultural drip-proof film is a coating obtained by applying and drying an aqueous emulsion composition containing an aqueous acrylic-modified urethane resin, colloidal silica particles, and a polyether-modified silicone surfactant. It is described that it is a film layer (see claim 1 of Patent Document 1).

Japanese Patent No. 3346891

  However, in the above-mentioned agricultural drip-proof film, a water-based acrylic-modified urethane resin is used as a resin for forming a coating layer, and there is a problem that the anti-fogging property in a low temperature environment is lowered. It is conceivable to use a hydrophilic resin in order to improve the flowability. However, when a coating layer is formed using a hydrophilic resin, the coating layer is damaged when rubbed in a moisture-containing state. There is a problem.

  As a resin contained in the antifogging composition for forming the antifogging layer, the present inventor has good antifogging properties even in a low temperature environment by setting the acid value of the hydrophobic binder resin to a specific range. It was found that it can be expressed.

  Accordingly, development of an antifogging composition that is excellent in antifogging property, particularly excellent in antifogging property in a low temperature environment, and capable of forming an antifogging layer in which a decrease in scratch resistance is suppressed is desired. Yes.

  The present invention has been made in view of the above problems, and is excellent in antifogging property, particularly excellent in antifogging property in a low temperature environment, and can form an antifogging layer exhibiting excellent scratch resistance. It aims at providing the antifogging composition which can be performed.

As a result of intensive studies to achieve the above object, the present inventor contains a hydrophobic binder resin and colloidal silica, and has a specific glass transition temperature (Tg) and acid value (AV) of the hydrophobic binder resin. The above (Tg) and (AV) are represented by the following formula (I)
| (Tg) / (AV) | × 100 ≦ 30 (I)
According to the antifogging composition satisfying the requirements, the inventors have found that the above object can be achieved, and have completed the present invention.

That is, the present invention relates to the following antifogging composition and antifogging film.
1. An antifogging composition comprising a hydrophobic binder resin and colloidal silica,
(1) The glass transition temperature (Tg) of the hydrophobic binder resin is 0 to 30 ° C.,
(2) The acid value (AV) of the hydrophobic binder resin is 60 to 300 mgKOH / g,
(3) The glass transition temperature (Tg) and the acid value (AV) of the hydrophobic binder resin satisfy the following formula (I):
An antifogging composition characterized by the above.
| (Tg) / (AV) | × 100 ≦ 30 (I)
2. Item 2. The antifogging composition according to Item 1, wherein the weight ratio (Ma / Mb) of the solid content mass (Ma) of the hydrophobic binder resin to the solid content mass (Mb) of the colloidal silica is 0.5 to 1.0. object.
3. Item 3. The antifogging composition according to Item 1 or 2, further comprising a surfactant.
4). Item 4. The antifogging composition according to any one of Items 1 to 3, further comprising a film-forming aid.
5). Item 5. An antifogging film having an antifogging layer comprising the antifogging composition according to any one of Items 1 to 4 on at least one surface of a synthetic resin film.

  The antifogging composition of the present invention is excellent in antifogging property, particularly excellent in antifogging property under a low temperature environment, and can form an antifogging layer exhibiting excellent scratch resistance.

It is sectional drawing which shows an example of the laminated constitution of the anti-fogging film of this invention. It is sectional drawing which shows an example of the laminated constitution of the anti-fogging film of this invention.

The antifogging composition of this invention contains hydrophobic binder resin and colloidal silica, (1) Glass transition temperature (Tg) of hydrophobic binder resin is 0-30 degreeC, (2) Hydrophobic binder resin Has an acid value (AV) of 60 to 300 mgKOH / g, and (3) the glass transition temperature (Tg) and acid value (AV) of the hydrophobic binder resin satisfy the following formula (I).
| (Tg) / (AV) | × 100 ≦ 30 (I)

Since the antifogging composition of the present invention contains a hydrophobic binder resin, the antifogging layer formed using the antifogging composition exhibits excellent scratch resistance.
Further, the glass transition temperature (Tg) of the hydrophobic binder resin is 0 to 30 ° C., the acid value (AV) is 60 to 300 mgKOH / g, and (Tg) and (AV) are represented by the above formula (I ) Is satisfied, the antifogging layer formed using the antifogging composition is excellent in antifogging property, and can exhibit excellent antifogging property even in a low temperature environment.
For this reason, the antifogging film which has the antifogging layer which consists of the said antifogging composition on the surface of at least one of a synthetic resin film also shows the outstanding scratch resistance, antifogging property and antifogging property in a low-temperature environment Also excellent.

  Hereinafter, the antifogging composition and antifogging film of the present invention will be described in detail.

1. Antifogging composition The antifogging composition of the present invention is an antifogging composition containing a hydrophobic binder resin and colloidal silica,
(1) The glass transition temperature (Tg) of the hydrophobic binder resin is 0 to 30 ° C.,
(2) The acid value (AV) of the hydrophobic binder resin is 60 to 300 mgKOH / g,
(3) The glass transition temperature (Tg) and acid value (AV) of the hydrophobic binder resin satisfy the following formula (I).
| (Tg) / (AV) | × 100 ≦ 30 (I)
In the above formula (I), | (Tg) / (AV) | represents the absolute value of a value obtained by dividing (Tg) by (AV).

  In the above formula (I), when the value calculated by | (Tg) / (AV) | × 100 exceeds 30, the antifogging layer formed using the antifogging composition is inferior in antifogging property, In particular, it is inferior in antifogging property in a low temperature environment. In the above formula (I), the value calculated by | (Tg) / (AV) | × 100 is preferably 3 to 30, more preferably 5 to 25, and still more preferably 10 to 25. By setting the value calculated by | (Tg) / (AV) | × 100 within the above range, the antifogging layer formed using the antifogging composition is more excellent in antifogging properties and in a low temperature environment. Anti-fogging property and better scratch resistance.

(Hydrophobic binder resin)
The hydrophobic binder resin contained in the antifogging composition of the present invention has a glass transition point (Tg) of 0 to 30 ° C. When the glass transition point of the hydrophobic binder resin is less than 0 ° C., the anti-blocking property of the antifogging layer is inferior. Moreover, when a glass transition point exceeds 30 degreeC, the anti-fogging property of an anti-fogging layer and the anti-fogging property in a low temperature environment are inferior, and it is also inferior to bending whitening resistance. The glass transition temperature is preferably 0 to 25 ° C.

  In addition, in this specification, the glass transition point of hydrophobic binder resin is a value measured by the measuring method based on JISK7121, and specifically, a differential scanning calorimeter (DSC; Seiko Electronics Co., Ltd.) ) Manufactured by SSC5200 (model number)), measured according to JIS K7121 (plastic glass transition temperature measurement method) in an inert gas under conditions of a heating rate of 10 ° C./min. In the above measurement method, a predetermined amount of sample is weighed on a sample pan and then dried at 130 ° C. for 3 hours before measurement.

  The hydrophobic binder resin contained in the antifogging composition of the present invention has an acid value (AV) of 60 to 300 mgKOH / g. When the acid value is less than 60 mgKOH / g, the antifogging layer formed using the antifogging composition is inferior in antifogging property, particularly in antifogging property under a low temperature environment. Moreover, when an acid value exceeds 300 mgKOH / g, the water resistance of the anti-fogging layer formed using the anti-fogging composition will fall, and the scratch resistance of an anti-fogging layer will be inferior. The acid value is preferably 100 to 200 mgKOH / g.

  In addition, in this specification, the acid value of hydrophobic binder resin is a value measured by the measuring method based on JISK0007.

  Examples of the hydrophobic binder resin contained in the antifogging composition of the present invention include acrylic resins, urethane resins, epoxy resins, polyester resins and the like, and acrylic resins are particularly preferably used.

  Examples of the acrylic resin include a homopolymer or a copolymer of a (meth) acrylic monomer, and a copolymer of a (meth) acrylic monomer and another copolymerizable monomer. . In the present specification, “(meth) acrylic monomer” means an acrylic monomer or a methacrylic monomer, and the same applies to other portions described as (meth). .

  Specific examples of the (meth) acrylic monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and i-propyl (meth) acrylate. , N-butyl (meth) acrylate, t-butyl (meth) acrylate, i-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl Alkyl (meth) acrylates such as (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate; 2- Hydroxyethyl ( ) Acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, glycidyl (meth) acrylate and other functional group-containing (meth) acrylates; (meth) acrylamide etc. Can be mentioned. These monomers can be used alone or in combination of two or more.

  Specific examples of other monomers copolymerizable with the (meth) acrylic monomer include aromatic vinyl monomers such as styrene and α-methylstyrene; vinyl pyridine, vinyl alcohol, and vinyl imidazole. Vinyl monomers such as vinyl pyrrolidone, vinyl acetate and 1-vinyl imidazole; itaconic acid esters such as monomethyl itaconate and monoethyl itaconate; monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, monobutyl fumarate And maleic acid esters such as monomethylmalate, monoethylmalate, monopropylmalate, monobutylmalate, and the like. These monomers can be used alone or in combination of two or more.

  As the urethane resin, for example, polyether, polyester, and polycarbonate anionic polyurethane resins can be used. These urethane resins may be used in the form of an aqueous composition or an emulsion.

  As the urethane-based resin, an emulsion of a polycarbonate-based anionic polyurethane resin is preferable in terms of excellent adhesion to the synthetic resin film of the anti-fogging layer, water resistance and surface strength (scratch resistance), and the anti-fogging layer has water resistance. In view of further improving the anti-fogging property and scratch resistance, and shortening the time until the anti-fogging property is exhibited, the emulsion of the polycarbonate-based anionic polyurethane resin having a silanol group is more preferable. These urethane resins may be used alone or in combination of two or more.

  In the antifogging composition of the present invention, the content of the solid content of the hydrophobic binder resin is preferably 0.5 to 10% by mass, based on 100% by mass of the antifogging composition, and 0.8 to 8.0 % By mass is more preferable, 1.0 to 5.0% by mass is still more preferable, and 1.5 to 3.5% by mass is particularly preferable. By making the content of the solid content of the hydrophobic binder resin within the above range, the antifogging layer formed using the antifogging composition is more resistant to scratches, antifogging, and antifogging in a low temperature environment. Excellent and also has excellent resistance to whitening.

(Colloidal silica)
The antifogging composition of the present invention contains colloidal silica. Colloidal silica is a state in which silica particles represented by the chemical composition formula of SiO ₂ are dispersed in a liquid to form a colloid. When the silica particles are primary particles, the average particle size of the silica particles contained in the colloidal silica is preferably 100 nm or less, and more preferably 60 nm or less. The average particle diameter of the primary particles of the silica particles is preferably 1 nm or more, and more preferably 3 nm or more. In addition, in this specification, the average particle diameter of the primary particle of the silica particle which forms the said colloidal silica can be measured by the BET method based on JISZ8830.

  As a commercial item of the colloidal silica containing the silica particle which is the said primary particle, the colloidal silica by Nissan Chemical Industries Ltd. brand name: "ST-XS" (average particle diameter of 4-6 nm), "ST-S" (average Particle diameter 8-11 nm), “ST-30” (average particle diameter 10-15 nm), “ST-50” (average particle diameter 20-25 nm), “ST-20L” (average particle diameter 40-50 nm), “ ST-XL "(average particle diameter 40-60 nm) etc. are mentioned.

  The silica particles contained in the colloidal silica may be secondary particles bonded with the primary particles. When the silica particles are secondary particles, examples of colloidal silica include necklace-shaped colloidal silica and chain-shaped colloidal silica.

<Necklace-shaped colloidal silica>
Necklace-shaped colloidal silica is colloidal silica containing secondary particles in which primary particles of silica particles are bonded in a ring shape. That is, the necklace-like colloidal silica is colloidal silica containing secondary particles in which primary particles of several to dozens of silica particles are aggregated in a ring shape like a pearl necklace. The secondary particles contained in the necklace-shaped colloidal silica may have a branched chain branched from the necklace-shaped ring as long as the primary particles are aggregated in a ring shape. The ring formed by the primary particles is not limited to a perfect circle or ellipse, and may be a distorted ring. The shape of the secondary particles contained in the necklace-shaped colloidal silica can be observed with an electron microscope.

  The primary particles of the silica particles forming the necklace-shaped colloidal silica are not particularly limited, and conventionally known particles can be used.

  5-30 nm is preferable and, as for the average particle diameter of the primary particle which forms the secondary particle contained in the said necklace-like colloidal silica, 8-25 nm is more preferable. By using the primary particles having an average particle diameter in the above range, the antifogging layer formed using the antifogging composition can exhibit better antifogging properties and more excellent scratch resistance. .

  The secondary particles contained in the necklace-like colloidal silica are preferably joined with primary particles and are continuous with a length of 70 to 200 nm, and more preferably are continuous with a length of 80 to 150 nm. The length of the secondary particles is the length of one round of the ring of secondary particles formed by the bonding of the primary particles. By setting the length of the secondary particles contained in the necklace-shaped colloidal silica within the above range, the antifogging layer formed using the antifogging composition exhibits better antifogging properties and is more excellent. Scratch resistance can also be shown. The length of the secondary particles contained in the necklace-shaped colloidal silica can be measured by taking a photograph with an electron microscope and measuring the length of one round of the taken secondary particles.

  As a commercial item of the above-mentioned necklace-shaped colloidal silica, a product name: “ST-PS-S”, “ST-PS-M”, “ST-PS-SO”, “ST” -PS-MO "and" ST-PS-S-AK ".

<Chained colloidal silica>
The chain colloidal silica is colloidal silica including secondary particles in which several to ten or more primary particles of silica particles are bonded in a chain, and is a colloidal silica including secondary particles having no cyclic structure. The silica particles contained in the chain colloidal silica may be linear or branched as long as the primary particles are aggregated in a chain. The shape of the chain colloidal silica can be observed with an electron microscope.

  The primary particles of the siliceous particles forming the chain colloidal silica are not particularly limited, and conventionally known ones can be used.

  3-30 nm is preferable and, as for the average particle diameter of the primary particle which forms the secondary particle contained in the said chain | strand-shaped colloidal silica, 10-15 nm is more preferable. By using primary particles of colloidal silica having a particle size in the above range, the antifogging layer formed using the antifogging composition exhibits better antifogging properties and also exhibits better scratch resistance. Can do.

  The secondary particles contained in the chain colloidal silica are preferably joined to primary particles and are continuous with a length of 30 to 150 nm, and more preferably continuous with a length of 40 to 100 nm. The length of the chain colloidal silica is the total length of the main chain length of the chain-like secondary particles formed by bonding of the primary particles and the branch chain length. By setting the length of the chain colloidal silica in the above range, an antifogging composition having excellent transparency can be obtained. The length of the chain colloidal silica can be measured by taking a photograph with an electron microscope, measuring the length of the main chain of the taken chain colloidal silica, and the length of the branched chain and summing them up.

  Examples of commercial products of the above-mentioned chain colloidal silica include “Snowtex-UP” series, which is a chain colloidal silica manufactured by Nissan Chemical Industries, Ltd., and more specifically, “ST-UP”. And “ST-OUP”.

  As the colloidal silica, colloidal silica containing silica particles as primary particles, necklace-shaped colloidal silica, and chain-shaped colloidal silica may be used alone, or two or more of these may be used in combination.

  In the antifogging composition of the present invention, the content of the solid content of the colloidal silica is preferably 0.5 to 10% by mass, based on 100% by mass of the antifogging composition, and 1 to 8% by mass. More preferably.

  In the antifogging composition of the present invention, the weight ratio (Ma / Mb) of the solid content mass (Ma) of the hydrophobic binder resin to the solid content mass (Mb) of the colloidal silica is 0.5 to 1. 0.0 is preferred. When (Ma / Mb) is in the above range, the antifogging layer formed using the antifogging composition is more excellent in antifogging property, particularly in a low temperature environment, and higher transparency. Can be shown. (Ma / Mb) is more preferably 0.6 to 0.9.

(Film forming aid)
The antifogging composition of the present invention preferably contains a film-forming aid. In the antifogging composition of the present invention, the film forming aid is a substance that promotes fusion between the particles of the hydrophobic binder resin particles. In particular, when the antifogging composition of the present invention contains a solvent and the emulsion particles of the hydrophobic binder resin are dispersed in the solvent, the effect of promoting fusion between the particles of the emulsion particles is remarkable. Become. When the antifogging composition of the present invention contains a film-forming auxiliary, the antifogging layer formed by applying the antifogging composition can exhibit excellent folding resistance and whitening resistance.

  The film-forming aid preferably has a boiling point of 190 ° C. or higher. By setting the boiling point of the film-forming aid to 190 ° C. or higher, the anti-fogging layer formed by applying the anti-fogging composition has more sufficient resistance to whitening. The boiling point of the film-forming aid is more preferably 200 ° C. or higher.

  In the present specification, the boiling point of the film-forming aid is a value measured under the condition of 1 atm using FP81HT / FP81C (model number, manufactured by METTLER TOLEDO).

  Examples of the film-forming aid include, for example, phthalic acid ester, adipic acid ester, trimellitic acid ester, phosphoric acid ester, citric acid ester, polyester, epoxidized vegetable oil, sebacic acid ester, azelaic acid ester, maleic acid ester, benzoic acid Acid esters and the like can be used.

  In the antifogging composition of the present invention, the content of the film-forming auxiliary is preferably 0.1 to 10.0% by mass, with the antifogging composition being 100% by mass, and preferably 0.5 to 5%. More preferably, it is 0.0 mass%.

(Surfactant)
The antifogging composition of the present invention preferably contains a surfactant. By containing the surfactant, the antifogging composition can be applied uniformly when applied to the synthetic resin film, and the antifogging layer having high transparency and uniform thickness can be formed. it can.

  As the surfactant, a polyhydric alcohol partial ester system comprising a polyhydric alcohol and higher fatty acids, including various known nonionic surfactants, anionic surfactants, and cationic surfactants. Of these, silicone surfactants and fluorine surfactants are preferred.

  Specific examples of the nonionic surfactant include, for example, sorbitan such as sorbitan monostearate, sorbitan monomyristate, sorbitan monopalmitate, sorbitan monobehenate, sorbitan / alkylene glycol condensate and fatty acid ester. Surfactants: glycerol monopalmitate, glycerol monostearate, glycerol monolaurate, diglycerol monopalmitate, glycerol dipalmitate, glycerol distearate, diglycerol monopalmitate monostearate, triglycerol monostearate Glycerin-based surfactants such as rate, triglycerin distearate or their alkylene oxide adducts; polyethylene glycol monostearate, polyethylene glycol monopalmitate Polyethylene glycol surfactants such as polyethylene glycol alkyl phenyl ether; trimethylolpropane surfactants such as trimethylolpropane monostearate; pentaerythritol surfactants such as pentaerythritol monopalmitate and pentaerythritol monostearate; Alkylene oxide alkylene oxide adduct; sorbitan / glycerin condensate and fatty acid ester; sorbitan / alkylene glycol condensate and fatty acid ester; diglycerin dioleate sodium lauryl sulfate; dodecylbenzenesulfonic acid sodium salt; cetyltrimethylammonium chloride Dodecylamine hydrochloride; lauric acid laurylamide ethyl phosphate; triethylcetylammonium ion Id; it includes those dodecyl pyridinium salts and isomers thereof; oleyl amino diethylamine hydrochloride.

  Specific examples of the silicone surfactant include, for example, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, amino modified silicone oil, alkyl modified silicone oil, phenyl modified silicone oil, carboxyl modified silicone oil, high grade Fatty acid-modified silicone oil, epoxy-modified silicone oil, vinyl group-containing silicone oil, alcohol-modified silicone oil, polyether-modified silicone oil, alkyl / polyether-modified silicone oil, fluorine-modified silicone oil, alkoxysilane, reactive siloxane oligomer, and these Examples include silicone elastomers having the following structure. These may be used alone or in combination of two or more. Among these, high leveling property can be imparted to the antifogging composition, and high antifogging property and antifogging property under a low temperature environment can be imparted to the antifogging layer formed using the antifogging composition. Polyether modified silicone oil is preferred.

  In the antifogging composition of the present invention, the content of the surfactant is 2 to 30 parts by mass with respect to a total of 100 parts by mass of the solid content of the colloidal silica and the solid content of the hydrophobic binder resin. Preferably, 5 to 15 parts by mass is more preferable. By setting the content of the surfactant in the above range, excellent leveling properties can be exhibited.

  The colloidal silica, hydrophobic binder resin, film-forming aid, and surfactant are usually commercially available products themselves, or products dispersed in a dispersion medium such as water, usually commercially available powders, etc. Any of those dispersed in a dispersion medium may be used.

  The antifogging composition of the present invention may contain a dispersion medium. The antifogging composition of the present invention is a composition in which the colloidal silica, the hydrophobic binder resin, the film-forming aid, the surfactant, and other components described later if necessary are dispersed in a dispersion medium. There may be. Examples of the dispersion medium include water-miscible solvents including water. Specifically, water such as tap water, deionized water, and pure water; monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; Polyhydric alcohols such as ethylene glycol, diethylene glycol and glycerin; cyclic alcohols such as benzyl alcohol; cellosolve acetates; ketones and the like. These dispersion media are desirably used by mixing with water.

(Other ingredients)
If the antifogging composition of the present invention contains the colloidal silica and the hydrophobic binder resin, an inorganic filler, an ultraviolet absorber, a light stabilizer, an antioxidant, a lubricant, and a heat stabilizer are further added as necessary. Other components such as an agent and an antistatic agent can be blended in usual amounts.

  Examples of the inorganic filler include various commonly used compounds, and oxides such as calcium, magnesium, and aluminum, hydroxides, carbonates, silicates, and composites thereof are particularly preferable. Specifically, clay (kaolin clay, soft clay, bird clay, calcined clay, wax stone clay), talc (talc, French chalk), asbestos (chrysotile, crocride, ammonite, anthrite, tremolite, actinolite), mica, bentonite , Sericite, zeolite, attapulgite, pumice powder, slate powder, feldspar powder, wollastonite, froth earth, tripolystone, meteorite, hydrous or anhydrous precipitated calcium silicate, magnesium silicate, etc .; hydro Talsite (hydrous or anhydrous aluminum / magnesium basic carbonate, sulfate, nitrate, phosphate, aluminum / zinc basic carbonate, sulfate, nitrate, phosphate); antimony trioxide, magnesium oxide, dioxide Titanium, zinc oxide, aluminum oxide Oxides such as (hydrous or anhydrous); calcium carbonate (heavy coal, light coal, colloidal coal or sedimentary coal cal, pepper, chalk, witching, arareite), magnesium carbonate (sedimentation, moisture and Carbonates such as anhydrous); barium sulfate (barite powder), precipitated barium sulfate, calcium sulfate (stone, soft stone, or precipitated), sulfates such as branfix; lime (aluminum hydroxide), magnesium hydroxide, etc. Consisting of carbon atoms (furnace, channel, lamp, thermal, acetylene), graphite, carbon fiber, carbon sphere, anthracite powder, etc .; copper, aluminum, bronze, lead, zinc, steel, etc. Metal powder, fiber, whisker or wire; glass such as fiber, sphere, foam, fly ash sphere, shirasu balloon Quality; barium ferrite; magnetite; molybdenum disulfide; potassium titanate, and the like. These may be used alone or in combination of two or more.

  Examples of the UV absorber include UV absorbers such as benzotriazole, benzoate, benzophenone, cyanoacrylate, and phenyl salicylate. Among these, benzophenone ultraviolet absorbers and / or benzotriazole ultraviolet absorbers are preferably used.

  As the light stabilizer, various compounds usually blended in the antifogging composition can be used. Specifically, for example, 4-acetoxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidine) adipate, tris (2,2,6, Examples include hindered amine compounds such as 6-tetramethyl-4-piperidyl) benzene-1,3,5-tricarboxylate.

  Examples of the antioxidant include 2,6-di-tert-butyl-4-methylphenol, 2,2′-methylenebis (6-tert-butyl-4-ethylphenol), dilauryl thiodipropionate, and the like. .

  Examples of lubricants or heat stabilizers include polyethylene wax, liquid paraffin, bisamide, stearic acid, zinc stearate, aliphatic alcohol, calcium stearate, barium stearate, barium ricinoleate, dibutyltin dilaurate, dibutyltin dimaleate, and organic phosphoric acid. Examples thereof include metal salts, organic phosphite compounds, phenols, β-diketone compounds and the like.

  Each of the other components can be used alone or in combination of two or more. The amount of each of the other components is preferably in a range that does not deteriorate the performance of the antifogging composition. Usually, the antifogging composition is 100% by mass, and the total amount is 10% by mass or less. You can choose.

  It does not specifically limit as a manufacturing method of the anti-fogging composition of this invention, A conventionally well-known method can be used. Examples thereof include a method of adding colloidal silica, a hydrophobic binder resin, and, if necessary, a film-forming aid, a surfactant, and other components, and stirring and mixing with a stirring device such as a homogenizer.

2. Antifogging layer An antifogging layer can be formed by applying the antifogging composition of the present invention to the surface of a synthetic resin film or the like and drying it. The thickness of the antifogging layer is preferably about 0.1 to 3.0 μm, more preferably about 0.5 to 2.0 μm, as the solid thickness of the antifogging composition after coating.

  The method for applying the antifogging composition to the surface of a synthetic resin film is not particularly limited. For example, doctor blade coating method, roll coating method, dip coating method, spray coating method, rod coating method, bar coating method, Known coating methods such as knife coating and brush coating may be mentioned. The antifogging composition of the present invention exhibits good leveling properties at the time of coating, and by drying the applied antifogging composition, the antifogging property, in particular, the antifogging property under a low temperature environment, and scratch resistance An anti-fogging layer having excellent properties can be formed. Any drying method of natural drying or forced drying may be adopted as the drying method. 30-120 degreeC is preferable and the drying temperature in the case of employ | adopting a forced drying method has more preferable 50-90 degreeC. Moreover, heat drying is mentioned as forced drying, As said heat drying, a hot-air drying method, an infrared drying method, a far-infrared drying method, etc. are mentioned.

  The contact angle of the antifogging layer formed from the antifogging composition of the present invention is preferably 50 ° or less. By setting the contact angle of the antifogging layer to 50 ° or less, the antifogging property of the antifogging film described later is particularly good. In addition, the said contact angle is the value measured on the measurement conditions computed by the measuring method based on JISR3257, and the capacity | capacitance of water droplet 3 microliter and (theta) / 2 method.

3. Antifogging film This invention is also an antifogging film which has the antifogging layer which consists of the said antifogging composition in the surface of at least one of a synthetic resin film. By forming the antifogging layer on the synthetic resin film, an antifogging film having excellent antifogging properties, particularly antifogging properties in a low temperature environment, and excellent scratch resistance can be obtained.

  The resin for forming the synthetic resin film is not particularly limited, but vinyl chloride resin; polyethylene (low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE)), polypropylene, ethylene -Polyolefin resins such as propylene copolymer and ethylene-butene copolymer; ethylene-vinyl acetate copolymer; ethylene-acrylic acid copolymer. In particular, when used as an agricultural film, it is preferable to use a polyolefin resin or an ethylene-vinyl acetate copolymer from the viewpoint of transparency and weather resistance. These may be used alone or in combination of two or more.

  The synthetic resin film may contain an infrared absorber, a light stabilizer, an ultraviolet absorber, an antioxidant, an antiblocking agent, a slip agent, a surfactant, a pigment, and the like.

  An inorganic filler etc. are mentioned as said infrared absorber.

  As the light stabilizer, those similar to the light stabilizer used in the above-described antifogging composition can be used.

  The application method, application conditions, antifogging layer thickness, and the like of the antifogging composition when forming the antifogging layer on the synthetic resin film may be the same as those described for the antifogging layer.

  When the adhesiveness between the synthetic resin film and the anti-fogging layer is not sufficient, pretreatment such as plasma discharge treatment or corona discharge treatment may be performed on the surface of the synthetic resin film in advance.

  The antifogging film is preferably an agricultural film. The anti-fogging film is excellent in anti-fogging property, particularly anti-fogging property in a low-temperature environment, and exhibits excellent scratch resistance. Therefore, it is suitable for use in crop cultivation houses, tunnels and the like as agricultural films. Yes.

  When the antifogging film is used as an agricultural film and is stretched on a house, it is preferably stretched so that the antifogging layer is formed on the inner surface of the house. By forming the anti-fogging layer on the inner surface of the house, it is possible to suppress the water droplets adhering to the inner surface of the anti-fogging film from falling on the cultivated crop.

  In the antifogging film, the antifogging layer may be formed on both surfaces of the synthetic resin film. When an antifogging film having an antifogging layer formed on both sides of a synthetic resin film is used as an agricultural film and spread on a house, the antifogging layer formed on the inner surface of the house as described above causes water droplets to be formed. In addition to being able to suppress falling to the cultivated crop, further, dirt on the outer surface of the house can be suppressed by the antifogging layer formed on the outer surface of the house.

  Examples of the present invention will be described below. The present invention is not limited to the following examples.

(Preparation of synthetic resin film)
Linear low density polyethylene (LLDPE: trade name “Elite 5100” manufactured by Dow Chemical Co., Ltd., density 0.920 g / cm ³ , MFR 0.8 g / 10 min), infrared absorber (inorganic filler: manufactured by Kyowa Chemical Industry Co., Ltd.) “DHT-4A”) and a light stabilizer (HALS: trade name “TINUVIN783” manufactured by BASF Japan) are mixed in the composition shown in Table 1, and a single-layer inflation molding apparatus (manufactured by HAAKE) equipped with a 25 mmφ die is used. A synthetic resin film having a thickness of 150 μm was prepared by extrusion molding under conditions of a molding temperature of 170 ° C. and a blow ratio of 2.0.

Examples 1-11 and Comparative Examples 1-4
According to the formulation shown in Table 1, the binder resin shown in Table 2, the colloidal silica shown in Table 3, mixed with deionized water as a dispersion medium, the surfactant shown in Table 4, and the film-forming auxiliary shown in Table 5 are mixed. The antifogging composition was prepared by adding as needed.

  Hydrophobic binder resins A to I were prepared as follows. That is, a four-necked flask was charged with a mixed liquid of 0.25 part of 2,2′-azobisisobutyronitrile and 2.5 parts of n-dodecyl mercaptan, and further 80 parts by weight of water was charged under a nitrogen gas stream. Heated to 60 ° C. While maintaining the reaction temperature at 60 to 70 ° C., 0.5 parts by mass of ammonium persulfate was added, and 100 parts by mass of a mixture prepared by mixing the monomers according to the formulation shown in Table 2 was added dropwise over 3 hours. did. Even after completion of the dropping, the temperature was kept at 60 to 70 ° C. for 2 hours and then cooled to obtain a dispersion liquid of the hydrophobic binder resin in the dispersion medium. In Table 1, the compounding amounts of the colloidal silica and the hydrophobic binder resin in the antifogging composition indicate the compounding amount in solid content. In Table 2, the composition of the hydrophobic binder resin indicates the composition in a solid content, and the hydrophobic binder resin is used in the state of an emulsion in which the solid content is dispersed in water.

  The antifogging composition prepared as described above was applied onto a synthetic resin film having a surface subjected to corona treatment using a # 5 bar coater.

  The anti-fogging film is obtained by holding the synthetic resin film coated with the anti-fogging composition in an oven at 70 ° C. for 1 minute and volatilizing the liquid dispersion medium of the anti-fogging composition to form an anti-fogging layer. Was prepared. The film thickness of the antifogging layer forming the antifogging film was about 0.8 μm.

  The following evaluation was performed about the antifogging composition and antifogging film of Examples 1-11 and Comparative Examples 1-4.

<Anti-fogging test> (Anti-fogging property (1): low-temperature anti-fogging property)
The test piece was installed at an angle of 30 ° with respect to the water surface so that the antifogging layer of the test piece was on the water tank side at the top of the water tank containing water. The distance between the water surface in the water tank and the lower end of the test piece was 30 cm. In this state, the temperature was maintained under conditions of an outside air temperature of 0 ° C. and a water temperature of 20 ° C., and the time until the water droplets adhering to the surface of the test piece flowed down was measured and evaluated according to the following criteria.
◎: 50 minutes or less ○: Over 50 minutes, 60 minutes or less Δ: Over 60 minutes, 70 minutes or less ×: Over 70 minutes

<Anti-fogging property test> (Anti-fogging property (2): Room temperature anti-fogging property)
The test piece was installed at an angle of 30 ° with respect to the water surface so that the antifogging layer of the test piece was on the water tank side at the top of the water tank containing water. The distance between the water surface in the water tank and the lower end of the test piece was 30 cm. In this state, the temperature was maintained under the conditions of an outside air temperature of 20 ° C. and a water temperature of 40 ° C., and the time until water droplets adhering to the surface of the test piece flowed was measured and evaluated according to the following criteria.
◎: 15 minutes or less ○: 15 minutes or more, 20 minutes or less △: 20 minutes or more, 35 minutes or less ×: 35 minutes or less

<Scratch resistance test> (Colloidal silica remaining rate)
The amount of colloidal silica present in the antifogging layer of the test piece (the amount of colloidal silica before peeling) was measured with a fluorescent X-ray apparatus. 0.2 mg of deionized water was sprayed on the anti-fogging layer. The anti-fogging layer sprayed with deionized water was rubbed 100 times with kraft paper under a load of 100 g, and the amount of colloidal silica remaining (the amount of colloidal silica after peeling) was measured with a fluorescent X-ray apparatus. The colloidal silica residual rate was calculated based on the following formula.
[Colloidal silica remaining rate (%)] = ([Amount of colloidal silica after peeling] / [Amount of colloidal silica before peeling]) × 100
Based on the calculated colloidal silica residual ratio, evaluation was performed according to the following criteria.
◎: Over 90% ○: Over 85%, 90% or less △: Over 50%, 85% or less ×: 50% or less

<Anti-blocking test>
By the method based on JIS P8147, the inclination angle was measured under the following measurement conditions using a tester industry: AB-502 friction angle measuring machine, and evaluated according to the following criteria. The measurement conditions are as follows. That is, both ends of a 13 cm × 20 cm test piece were fixed with tape so that the anti-fogging layer was on the upper side. Further, a 10 cm × 11 cm test piece was attached to a 1000 mg (6.3 cm × 10.2 cm) sliding piece with a tape so that the antifogging layer was located below. The antifogging layers of the two test pieces were set so as to rub against each other, and the inclination angle at which the sliding pieces began to slide was measured.
◎: 25 ° or less ○: Over 25 °, 35 ° or less Δ: Over 35 °, 45 ° or less ×: Over 45 °

<Transparency test> (Haze measurement)
Haze was measured using Nippon Denshoku Industries Co., Ltd .: MDH2000 by a measuring method based on JIS K7105, and evaluated according to the following criteria.
◎: 15% or less ○: Over 15%, 20% or less ×: Over 20%

<Folding whitening resistance test>
Measures the haze using Nippon Denshoku Kogyo Co., Ltd .: MDH2000 (haze value before fold) by the measurement method based on JIS K7105, and measures the haze after attaching two folds in the MD and TD directions. (Haze value after folding) and the folding whitening resistance were calculated based on the following formula.
[Folding resistance to whitening (%)] = [Haze value after folding (%)]-[Haze value before folding (%)]
The calculated folding whitening resistance was evaluated according to the following criteria.
◎: 3% or less ○: Over 3%, 5% or less △: Over 5%, 10% or less ×: Over 10%

  The results are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 ... Anti-fogging film, 2 ... Synthetic resin film, 3 ... Anti-fogging layer

Claims (5)

An antifogging composition comprising a hydrophobic binder resin and colloidal silica,
(1) The glass transition temperature (Tg) of the hydrophobic binder resin is 0 to 30 ° C.,
(2) The acid value (AV) of the hydrophobic binder resin is 60 to 300 mgKOH / g,
(3) The glass transition temperature (Tg) and the acid value (AV) of the hydrophobic binder resin satisfy the following formula (I):
An antifogging composition characterized by the above.
| (Tg) / (AV) | × 100 ≦ 30 (I)   The antifogging property according to claim 1, wherein the weight ratio (Ma / Mb) of the solid content mass (Ma) of the hydrophobic binder resin to the solid content mass (Mb) of the colloidal silica is 0.5 to 1.0. Composition.   Furthermore, the antifogging composition of Claim 1 or 2 containing surfactant.   Furthermore, the antifogging composition in any one of Claims 1-3 containing a film-forming adjuvant.   The anti-fogging film which has an anti-fogging layer which consists of an anti-fogging composition in any one of Claims 1-4 in the surface of at least one of a synthetic resin film.