JP2019026823A - Antifogging composition and antifogging film - Google Patents

Abstract

To provide an antifogging composition and an antifogging film each of which has excellent antifogging property, is excellent in transparency and allows for suppression of blocking between coated films before spread during storage in a warehouse.SOLUTION: The antifogging composition is provided that contains a synthetic resin (A) and an inorganic compound as main components, the inorganic compound including at least inorganic particles (B) and inorganic particles (C), the inorganic compound has multi-peaked particle size distribution having at least two peaks in particle size distribution, the peak of the particle size distribution of the inorganic particles (B) is within a range of less than 150 nm of the particles size, the peak of the particle size distribution of the inorganic particles (C) is within a range of 150 nm or more of the particle size, and a content of the inorganic particles with a particle size of 150 nm or more is 0.01 mass% or more and 25 mass% or less based on the total mass of a solid component of the antifogging composition.SELECTED DRAWING: None

Description

  The present invention relates to an antifogging composition having excellent transparency and antiblocking properties and having an antifogging property even in an environment used for a long period of time, and an antifogging film comprising a layer comprising the antifogging composition. .

  In recent years, various thermoplastic resins have been used in various fields. Many of the molded products produced from these thermoplastic resins have a problem that the surface of the molded product is fogged depending on the use conditions such as the use temperature of the molded product because the surface is hydrophobic. Specifically, in a food packaging film, when fogging occurs, the contents become difficult to see. In addition, in agricultural films used in greenhouses, when cloudy weather occurs, the transmission of sunlight rays deteriorates, so that the growth of plants deteriorates, or large water droplets generated by cloudy fine water droplets gather in the greenhouse. Falling into a plant that causes damage to the young buds or causes disease.

  As a method for solving such problems, a method for imparting antifogging properties to the surface of a thermoplastic resin molded product is known. As a method for imparting this antifogging property, a thermoplastic material is kneaded with a hydrophilic substance such as a surfactant to form a molded product, or the surface of the thermoplastic resin molded product is, for example, silica or alumina. Various methods for applying a mixture with a surfactant have been proposed.

  However, the former method can coordinate with the hydrophilic substance kneaded in the thermoplastic resin being ejected on the surface of the molded product, and can impart antifogging properties to the molded product, but the kneaded surface activity A hydrophilic substance such as an agent easily flows out by water, and the antifogging property disappears in a short period of time. On the other hand, the latter method has a problem in that the coating film provided by coating has poor adhesion to the thermoplastic resin, and thus the coating film may fall off over time.

  In recent years, for example, a method for applying a mixture of silica or alumina and a surfactant to the surface of a thermoplastic resin molded article has been improved, and a technique for improving the adhesion with a thermoplastic resin has been invented ( For example, Patent Documents 1 and 2).

  However, for agricultural films with anti-fogging paint coat type, etc., after the production, the film is wound up, transported, stored in a processing place or warehouse, or the processed film is used before spreading. There is a problem that the coating films block in the presence of moisture such as dew condensation water and rain water when the person is storing it, and the improvement thereof has been demanded. This phenomenon is caused by the fact that the anti-fogging coatings imparted with hydrophilicity come into contact with each other through moisture, and are difficult to peel off due to effects such as pressure and heat due to the film's own weight.

  Although various companies have been actively researching these anti-fogging properties and anti-blocking properties between coatings, anti-fogging properties are improved by improving the hydrophilicity of coatings, but blocking via water occurs. However, if the hydrophobicity is increased in order to suppress blocking, there is a problem that the antifogging property is lowered.

  In addition, there is also known a method in which unevenness is generated in the coated film by imparting unevenness to the base film to prevent blocking, but there is a problem that transparency is impaired due to scattering of the surface.

  As described above, a technology having a good balance of anti-fogging performance, transparency and anti-blocking performance has not been established yet, and an agricultural film having a good balance of these properties is demanded.

  In order to solve this problem, for example, in Patent Document 3 (Japanese Patent Application Laid-Open No. 2007-282625), a lower layer coating film containing a synthetic resin binder is formed on the surface of the base film that becomes the inside of the house at the time of expansion. A technique for improving anti-fogging properties and forming excellent anti-blocking properties by forming an upper layer coating film containing fine particles as a main component is disclosed.

  However, such a multi-layer coating requires a plurality of coating and drying steps in the production process, so that the process is complicated and the cost tends to be disadvantageous. Further, the blocking performance was not sufficient.

JP-A-9-87615 JP 2001-89751 A JP 2007-282625 A

  The present invention has been made to solve the above technical problem, and can be produced by a single coating process, has excellent anti-fogging properties, has excellent transparency, and is stored in a warehouse. An object of the present invention is to provide an antifogging composition and an antifogging film that make it possible to suppress blocking between coating films that occur in the above.

  As a result of intensive studies, the inventors of the present invention contain a synthetic resin (A) and an inorganic compound as main components, and the inorganic compound contains at least inorganic particles (B) and inorganic particles (C), and , Having a multimodal particle size distribution having at least two peaks in the particle size distribution, and the particle size distribution peak of the inorganic particles (B) is in the range of less than 150 nm, and the particle size of the inorganic particles (C) The peak of the distribution is on the surface of the base film that has a particle size in the range of 150 nm or more and contains a specific amount of inorganic particles having a particle size of 150 nm or more, and the base film that is inside the house at the time of stretching. By providing the layer which consists of the said anti-fogging composition, it discovered that the said objective was achieved and came to complete this invention.

That is, the present invention
[1] A synthetic resin (A) and an inorganic compound as main components, and the inorganic compound is an antifogging composition containing at least inorganic particles (B) and inorganic particles (C),
The inorganic compound has a multimodal particle size distribution having at least two peaks in the particle size distribution;
The peak of the particle size distribution of the inorganic particles (B) is in the range where the particle size is less than 150 nm,
The peak of the particle size distribution of the inorganic particles (C) is in the range where the particle size is 150 nm or more,
Content of the inorganic particle whose particle diameter is 150 nm or more is 0.01 mass% or more and 25 mass% or less with respect to the total mass of the solid component of the said antifogging composition. Composition.
[2] The antifogging composition as described in [1], wherein the particle size distribution peak of the inorganic particles (C) is in the range of 150 nm or more and 1000 nm or less.
[3] The value X (nm) of the particle size distribution peak of the inorganic particles (C) and the content Y (mass%) of inorganic particles having a particle diameter of 150 nm or more with respect to the total mass of the solid components of the antifogging composition. The antifogging composition according to [1] or [2], wherein a value K which is a product of is from 10 to 8000.
[4] A substrate film is provided, and the layer made of the antifogging composition according to any one of [1] to [3] is provided on at least one side of the substrate film. Anti-fogging film.
[5] The antifogging film as described in [4], wherein the base film contains a polyolefin resin.
[6] The antifogging film as described in [4] or [5], which is used for agriculture.
Is provided.

  The anti-fogging composition and anti-fogging film of the present invention have excellent anti-fogging properties even for long-term use, and suppress poor visibility and water drop due to condensation, and further impair transparency. And blocking between coating films can be suppressed.

  Below, the antifogging composition and antifogging film of this invention are demonstrated in detail.

  The antifogging composition of the present invention contains a synthetic resin (A) and an inorganic compound as main components, and the inorganic compound contains at least inorganic particles (B) and inorganic particles (C), and has a particle size distribution. The particle size distribution has a multimodal particle size distribution having at least two peaks, the particle size distribution peak of the inorganic particles (B) is in the range of less than 150 nm, and the particle size distribution peak of the inorganic particles (C) is The content of inorganic particles having a particle diameter in the range of 150 nm or more and a particle diameter of 150 nm or more is 0.01% by mass or more and 25% by mass or less with respect to the total mass of the solid component of the antifogging composition. Is important.

<Inorganic compounds>
The inorganic compound contained in the antifogging agent of the present invention includes at least inorganic particles (B) and inorganic particles (C), and has a multimodal particle size distribution having at least two peaks in the particle size distribution.

<Inorganic particles (B)>
The peak of the particle size distribution of the inorganic particles (B) used in the present invention is not particularly limited as long as the particle diameter is in the range of less than 150 nm, but is preferably in the range of 10 nm or more and less than 150 nm, More preferably, it is within the range of 15 nm or more and less than 150 nm, and further preferably within the range of 20 nm or more and less than 130 nm. When the peak of the particle size distribution of the inorganic particles (B) is within the above range, it is excellent in dispersibility, and when applied to a film, it can be suppressed that the transparency of the coating film is inferior.
In addition, the inorganic particles (B) may have two or more particle size distribution peaks in a range where the particle size is less than 150 nm.
Incidentally, the measurement of the peak of the particle size distribution of the inorganic particles (B) of the present invention is to determine the position of the peak by measuring the volume-based particle size distribution measured by a dynamic light scattering particle size distribution measuring device, or The photograph which expanded the particle | grains with the scanning electron microscope (Nippon FEI company: NovaNanoSEM) was image | photographed, and the analysis of a photographic image was then based on this photograph using image analysis software (Nippon Roper company: Image-Pro Premier). By removing noise in the image and using a plurality of photographic images, arbitrarily select 2000 particles, and using the obtained particle size data, the horizontal axis represents the particle size and the vertical axis represents the volume. The peak position can be obtained by creating a histogram based on the above and obtaining a volume-based particle size distribution.

  As the inorganic particles (B) used in the antifogging composition of the present invention, those in which one or a combination of two or more inorganic particles having a particle size distribution peak within a range of particle diameter of less than 150 nm can be used. .

  Examples of the inorganic particles (B) used in the present invention include silica, alumina, water-insoluble lithium silicate, zinc oxide, zirconium oxide, iron hydroxide, tin hydroxide, titanium oxide, antimony oxide, barium sulfate, and zinc antimonate. Particles. Among them, silica and alumina particles are preferably used, and these may be used alone or in combination.

Further, the mass ratio of the synthetic resin (A) and the inorganic particles having a particle diameter of less than 150 nm in the antifogging composition is preferably 5:95 to 75:25, and 5:95 to 70:30. Is more preferable, and it is still more preferable that it is 5: 95-65: 35. By setting the mass ratio of the synthetic resin (A) and the inorganic particles having a particle diameter of less than 150 nm to the above, sufficient antifogging properties can be obtained.
Here, the mass of the inorganic particles having a particle diameter of less than 150 nm refers to the total mass of the inorganic particle group having a particle diameter of less than 150 nm among the inorganic particles (B) and the inorganic particles (C).

<Inorganic particles (C)>
The peak of the particle size distribution of the inorganic particles (C) of the present invention is not particularly limited as long as the particle diameter is in the range of 150 nm or more, but is preferably in the range of 150 nm to 1000 nm, preferably 170 nm to 700 nm. More preferably, it is in the range of 180 nm to 600 nm. When the peak of the particle size distribution of the inorganic particles (C) is within the above range, it is possible to prevent the coating film from being inferior when coated on a film with excellent antiblocking properties.
In addition, the inorganic particles (C) may have two or more particle size distribution peaks within a particle diameter range of 150 nm or more.
In addition, the measurement of the peak of the particle size distribution of the inorganic particles (C) of the present invention is to determine the position of the peak by measuring the volume-based particle size distribution measured by a dynamic light scattering particle size distribution measuring device, or The photograph which expanded the particle | grains with the scanning electron microscope (Nippon FEI Co., Ltd .: Nova Nano SEM) was image | photographed, and the analysis of a photographic image using image analysis software (Nippon Roper: Image-Pro Premier) based on this photograph was carried out. By removing noise in the image and using a plurality of photographic images, arbitrarily select 2000 particles, and using the obtained particle size data, the horizontal axis represents the particle size and the vertical axis represents the volume. The peak position can be obtained by creating a histogram based on the above and obtaining a volume-based particle size distribution.

  As the inorganic particles (C) used in the antifogging agent composition of the present invention, it is possible to use one or a combination of two or more inorganic particles having a particle size distribution peak within a particle diameter range of 150 nm or more. I can do it.

  Examples of the inorganic particles (C) used in the present invention include silica, alumina, water-insoluble lithium silicate, zinc oxide, zirconium oxide, iron hydroxide, tin hydroxide, titanium oxide, antimony oxide, barium sulfate, and zinc antimonate. Particles. Among them, silica and alumina particles are preferably used, and these may be used alone or in combination.

Further, it is important that the inorganic particles having a particle diameter of 150 nm or more have a content of 0.01% by mass to 25% by mass with respect to the total mass of the solid components of the antifogging composition. Moreover, the lower limit of the content of inorganic particles having a particle diameter of 150 nm or more is preferably 0.05% by mass or more, and more preferably 0.1% by mass or more. Further, the upper limit of the content of inorganic particles having a particle diameter of 150 nm or more is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 11% by mass or less, It is particularly preferably 8% by mass or less. By making content of the inorganic particle whose particle diameter is 150 nm or more into said range, it is excellent in antiblocking property, and when apply | coating to a film, it can suppress more that the transparency of a coating film falls.
Here, the mass of the inorganic particles having a particle diameter of 150 nm or more refers to the total mass of the inorganic particles having a particle diameter of 150 nm or more among the inorganic particles (B) and the inorganic particles (C).

  In addition, the inorganic particles (C) of the present invention are inorganic particles having a peak value X (nm) in the particle size distribution of the inorganic particles (C) and a particle size of 150 nm or more with respect to the total mass of the solid components of the antifogging composition. The value K (peak value in particle size distribution X (nm) × content Y (mass%)) is preferably 10 or more and 8000 or less, and preferably 20 or more and 7000 or less. More preferably, it is 25 or more and 3000 or less. By setting the value of K in the above range, blocking can be further suppressed and transparency can be further improved.

  In addition, the inorganic particles (B) and inorganic particles (C) used in the present invention impart hydrophilicity to the surface of the base film in order to improve the adhesion between the inorganic particles during drying or between the inorganic particles and the synthetic resin. Surface treatment can be performed within a range that does not impede. As a surface treatment method for the surface of silica or alumina, known methods can be used, and among them, a silane compound such as a silane coupling agent can be preferably used.

  The inorganic compound can provide good antifogging properties when the antifogging composition of the present invention is used as an antifogging layer, and further functions to prevent blocking by a synthetic resin or the like on the surface of the coating film. Is.

  In addition to the inorganic particles (B) and the inorganic particles (C), the inorganic compound used in the present invention is not limited to the effects of the present invention, and other inorganic compounds such as silica, alumina, water-insoluble lithium silicate, Zinc oxide, zirconium oxide, iron hydroxide, tin hydroxide, titanium oxide, antimony oxide, barium sulfate, zinc antimonate and the like can be included.

  The inorganic particles (B) and the inorganic particles (C) of the present invention may be particles made of the same kind of compound or particles made of different kinds of compounds.

<Synthetic resin (A)>
Examples of the synthetic resin (A) used in the present invention include acrylic resins, epoxy resins, urethane resins, polyester resins, and the like. It is preferable to use a resin and / or a urethane-based resin, and more preferably (i) one made of a hydrophilic acrylic polymer, (ii) one made of a hydrophobic acrylic resin, and (iii) a hydrophobic acrylic. A resin composed of a polyurethane resin and a polyurethane emulsion are preferred because of their respective characteristics. Also, (iv) a copolymer resin of a monomer used for the resin can be preferably used. Examples of (iv) include urethane-modified polyester urethane.

  Examples of the acrylic resin include (a) those made of a hydrophilic acrylic polymer, (b) those made of a hydrophobic acrylic resin, or those made of a copolymer containing (a) and (b). However, (a) is particularly preferable in terms of early initial antifogging wetness, but it tends to be washed away, so that it is necessary to impart some water resistance to the coating film by a crosslinking reaction or the like. On the other hand, (b) is excellent in water resistance and preferable in terms of antifogging durability, but the ratio of the synthetic resin (A) to the inorganic particles (B) in order to suppress surface hydrophobicity by hydrophobic acrylic. Need to be adjusted.

  As the hydrophilic acrylic polymer of (a), a hydroxyl group-containing vinyl monomer component is a main component (preferably 60 mass% to 99.9 mass%, more preferably 65 mass% to 95 mass%), acid Examples thereof include a copolymer containing 0.1 to 30% by mass of a group-containing vinyl monomer component, a partially neutralized product or a completely neutralized product thereof. Examples of the hydroxyl group-containing vinyl monomer component include hydroxyalkyl (meth) acrylates, such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) An acrylate etc. are mention | raise | lifted. These may be homopolymers, or may be copolymers of these hydroxyalkyl (meth) acrylates as main components and other monomers that can be copolymerized therewith.

  Examples of the acid group-containing monomer copolymerizable with these hydroxyalkyl (meth) acrylates include carboxylic acids, sulfonic acids and phosphonic acids, and (meth) acrylic acid belonging to carboxylic acids is particularly preferred.

  Examples of other copolymer components include styrene, vinyl toluene, vinyl chloride, vinylidene chloride, vinyl oxide, (meth) acrylic acid esters, N, N-dimethylaminoethyl (meth) acrylamide, vinyl pyridine, and the like. . In addition to these, a monomer containing a crosslinking site is copolymerized and an appropriate crosslinking agent is reacted at an appropriate crosslinking temperature, whereby the crosslinking density can be improved and the water resistance can be improved.

  As the hydrophobic acrylic resin (b), at least a total of 60% by weight of a monomer comprising an alkyl ester of acrylic acid or methacrylic acid, or a single unit of an alkyl ester of acrylic acid or methacrylic acid and an alkenylbenzene. A monomer mixture and 0 to 40% by mass of a copolymerizable α, β-ethylenically unsaturated monomer are obtained by emulsion polymerization in an aqueous medium in the presence of an emulsifier, for example, according to normal polymerization conditions. And water dispersible polymers or copolymers.

  Examples of alkyl esters of acrylic acid or methacrylic acid used in the production of hydrophobic acrylic resins include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid-n-propyl ester, acrylic acid isopropyl ester, acrylic acid-n- Butyl ester, acrylic acid-2-ethylhexyl ester, acrylic acid decyl ester, methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid-n-propyl ester, methacrylic acid isopropyl ester, methacrylic acid-n-butyl ester, methacrylic acid- 2-ethylhexyl ester, methacrylic acid decyl ester, and the like. Generally, an alkyl alkyl group having 1 to 20 carbon atoms and / or a methyl group having 1 to 20 carbon atoms is used. Acrylic acid alkyl esters are used. Examples of alkenylbenzenes include styrene, α-methylstyrene, vinyltoluene and the like.

  Examples of α, β-ethylenically unsaturated monomers used to obtain hydrophobic acrylic resins include α, β such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and itaconic acid. -Ethylenically unsaturated carboxylic acids; α, β-ethylenically unsaturated sulfonic acids such as ethylene sulfonic acid; 2-acrylamido-2-methylpropanoic acid; α, β-ethylenically unsaturated phosphonic acids; acrylic acid or methacrylic acid Hydroxyl group-containing vinyl monomers such as hydroxyethyl; acrylonitriles; acrylic amides; glycidyl esters of acrylic acid or methacrylic acid, and the like. These monomers may be used alone or in combination of two or more, and are preferably used in the range of 0 to 40% by mass. It can suppress that anti-fogging performance falls by making the usage-amount into said range.

  The acrylic resin is a known emulsifier, for example, an anionic surfactant, a cationic surfactant, or a nonionic surfactant, in the presence of one or more kinds in an aqueous medium. It can be obtained by a method of emulsion polymerization, a method of polymerization using a reactive emulsifier, a method of polymerizing based on an oligo soap theory without containing an emulsifier. In the case of the polymerization method in the presence of an emulsifier, these emulsifiers are used in the range of 0.1 to 10% by mass with respect to the total amount of charged monomers, to adjust the polymerization rate and to disperse the resin to be synthesized. It is preferable from the viewpoint of stability.

  Examples of the polymerization initiator preferably used for the production of the acrylic resin include persulfates such as ammonium persulfate and potassium persulfate; organic peroxides such as acetyl peroxide and benzoyl peroxide. These can be used in the range of 0.1 to 10% by mass relative to the total amount of monomers charged.

  The hydrophobic acrylic resin preferably has a low glass transition temperature and is not limited. For example, a hydrophobic acrylic resin preferably has a temperature of −50 to 110 ° C., and preferably has a temperature of −30 to 80 ° C. By setting the glass transition temperature within the above range, the inorganic particles (B) can be prevented from agglomerating and becoming a non-uniform dispersion state, and a transparent uniform coating film can be easily obtained.

  The hydrophobic acrylic resin is preferably used as an aqueous emulsion. An aqueous emulsion obtained by polymerization of each monomer in an aqueous medium may be used as it is, or may be diluted by adding a liquid dispersion medium to this, and also produced by the polymerization as described above. A polymer may be collected separately and re-dispersed in a liquid dispersion medium to form an aqueous emulsion.

  On the other hand, examples of urethane resins that can be used in the present invention include polyether-based, polyester-based, and polycarbonate-based anionic polyurethane aqueous compositions and emulsions. A polycarbonate-based anionic polyurethane emulsion is preferred in terms of adhesion, water resistance and scratch resistance. In addition, a polycarbonate-based anionic polyurethane emulsion containing a silanol group is more preferable from the viewpoints of further improving the water resistance and scratch resistance of the antifogging coating, the time until the antifogging property is developed, and the antifogging durability. These may be used alone or in combination of two or more.

  A polycarbonate-based anionic polyurethane emulsion containing a silanol group comprises a polyurethane resin containing at least one silanol group in the molecule and a strongly basic tertiary amine as a curing catalyst. Refers to a colloidal dispersion system (emulsion) in which the silanol group-containing polyurethane resin and the strongly basic tertiary amine are dissolved in the aqueous phase, or a colloidal dispersion system in which fine particles are dispersed.

  It is preferable that the amount of the polyurethane aqueous composition is 0.01 or more and 2 or less, more preferably 0.01 or more and 1 or less, with respect to the hydrophobic acrylic resin in terms of solid mass ratio. By setting it to 0.01 or more, the scratch resistance can be improved, and it is possible to suppress an increase in the time until the antifogging property is exhibited. Moreover, by setting it as 2 or less, it becomes easy to improve damage resistance in proportion to a compounding quantity, and it can suppress that the coating film formed after application | coating becomes white turbidity and a light transmittance falls.

  For anti-fogging compositions, conventional additives such as solvents, antifoaming agents, plasticizers, film-forming aids, thickeners, pigments, pigment dispersants, weather resistance improvers, heat stabilizers, etc. Can be contained.

The method for preparing the antifogging composition of the present invention is not particularly limited. For example, the synthetic resin (A), inorganic particles (B), inorganic particles (C), and optional additives as necessary Can be prepared by mixing.
In the case of a film composed of an antifogging composition layer and a base film layer, the antifogging composition is composed of water, an organic solvent (including a mixed solvent composed of two or more organic solvents) or water and one or more kinds. A dispersion or solution containing an antifogging composition (hereinafter also referred to as “antifogging agent composition”) is prepared by dispersing or dissolving in a mixed solvent with an organic solvent, and the antifogging agent composition is used as a base material. It is preferable to form a layer of the antifogging composition by coating on the surface of the film. Further, when preparing the antifogging agent composition, the synthetic resin (A), the inorganic particles (B), the inorganic particles (C), and optional additives (hereinafter referred to as “constituent components of the antifogging composition”). )) In advance, and then dispersed or dissolved in water, an organic solvent (including a mixed solvent composed of two or more organic solvents), or a mixed solvent of water and one or more organic solvents. In addition, any one or more of the synthetic resin (A), the inorganic particles (B), the inorganic particles (C), and any optional additives may be added with water, an organic solvent (two or more organic solvents). (Including a mixed solvent) or dispersed or dissolved in a mixed solvent of water and one or more organic solvents, and then the remaining components of the antifogging composition may be added to the prepared dispersion or solution.
The antifogging agent composition contains a synthetic resin (A), inorganic particles (B), and inorganic particles (C). The dispersibility of the synthetic resin (A) in the antifogging agent composition is as follows. In order to make it better, it is preferable to use a dissolved product or an emulsion in the dispersion. In order to make the dispersibility of the inorganic compound better, the inorganic compound is preferably an inorganic colloidal substance.

  In the present invention, the method for forming the antifogging composition layer on the surface of the substrate is not particularly limited, and a generally used method can be used. For example, a solution or dispersion of an antifogging composition is known per se, such as doctor blade coating, roll coating, dip coating, spray coating, rod coating, bar coating, knife coating, brush coating, etc. What is necessary is just to apply | coat to the surface of a base material using an application | coating method, and to dry after application | coating.

As a drying method after coating, either a natural drying method or a forced drying method may be employed. When the forced drying method is employed, the drying method is usually 50 to 200 ° C, preferably 70 to 180 ° C. Can do. In a film using a synthetic resin as a base material, the occurrence of deformation such as melting and heat shrinkage can be suppressed by setting the drying temperature to 200 ° C. or lower.
In addition, for drying by heating, an appropriate method such as a hot air drying method, an infrared drying method, a far infrared drying method, and an ultraviolet curing method may be employed, and the hot air drying method is employed in consideration of drying speed and stability. Is preferred.

  Another aspect of the present invention is an antifogging film in which a layer comprising the antifogging composition of the present invention is provided on the surface of at least one side of the base film.

The resin constituting the base film that can be used in the present invention is not particularly limited as long as it is a thermoplastic resin. For example, polyvinyl chloride, polyethylene terephthalate, polyamide, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, Ethylene / vinyl acetate copolymer, ionomer, acrylic ester, methacrylic ester and the like can be used.
These resins may be used alone or in combination of two or more.

  The base film may be a single layer or a multilayer having two or more layers, for example, a three-layer having an inner layer, an intermediate layer and an outer layer, or a multilayer having three or more layers.

  The base film can be mixed with conventional additives such as plasticizers, film-forming aids, thickeners, pigments, pigment dispersants, weather resistance improvers, heat stabilizers, etc., as necessary. .

<Examples 1-7, Comparative Examples 1-2>
EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example and a comparative example, this invention is not limited to the following examples, unless the summary is exceeded.

(1) Production of base film As a three-layer inflation molding device, 100 mmφ (made by Pla Koken Co., Ltd.) was used for a three-layer die, and the extruder had an inner tube outer layer of 30 mmφ (made by Pla Giken Co., Ltd.), intermediate The layer is 40 mmφ (manufactured by Pla Giken Co., Ltd.), outer and inner layer extruder temperature 180 ° C., intermediate layer extruder temperature 170 ° C., die temperature 180 to 190 ° C., blow ratio 2.0 to 3.0, take-off speed 3 A three-layer laminated film having a thickness of 0.15 mm was produced under the processing conditions of ˜7 m / min, where the outer layer / intermediate layer / inner layer had a thickness ratio of 30/90/30. Since these films are used with the end of the tube cut open when the house is stretched, the tube outer layer during film formation becomes the inner layer (inner surface) of the house when stretched when unfolded.

<Material used for base film>
Low density polyethylene (LDPE): “F022NH” manufactured by Ube Maruzen Polyethylene Co., Ltd. (MFR: 0.8 g / 10 min, density 0.922)
-Metallocene PE (Me-PE): Kernel “KF270” manufactured by Nippon Polyethylene Co., Ltd. (MFR: 2 g / 10 min, density 0.907)
・ Ethylene / vinyl acetate copolymer (EVA1): (vinyl acetate content 5 mass%, MFR 2 g / 10 min)
・ Ethylene / vinyl acetate copolymer (EVA2): (vinyl acetate content 15% by mass, MFR 2 g / 10 min)
・ Ultraviolet absorber A: “Triaryltriazine UV absorber UV1164” manufactured by Cytec Corporation
・ Synthetic hydrotalcite A: “DHT4A” manufactured by Kyowa Chemical Co., Ltd.
-Light stabilizer A: Light stabilizer "chimassorb944" manufactured by Ciba Specialty Chemicals
-Ethylene / Cyclic aminovinyl copolymer: “Novatech LD / XJ100H” manufactured by Nippon Polyethylene Co., Ltd. (MFR = 3 g / 10 min, density = 0.931 g / cm ³ , melting point = 111 ° C.)

<Composition of each layer of base film>
Inner layer: LDPE (10 parts by mass), Me-PE (90 parts by mass), ethylene / cyclic aminovinyl copolymer (6 parts by mass)
Intermediate layer: LDPE (2 parts by mass), EVA1 (98 parts by mass), synthetic hydrotalcite A (6 parts by mass), ultraviolet absorber A (0.06 parts by mass), light stabilizer A (0.4 parts by mass) )
Outer layer: LDPE (10 parts by mass), EVA2 (90 parts by mass), ethylene / cyclic aminovinyl copolymer (6 parts by mass)

(2) Surface Treatment of Film The surface (outer layer) corresponding to the house inner layer side of the obtained base film was subjected to corona discharge treatment at a discharge voltage of 120 V, a discharge current of 4.7 A, and a line speed of 10 m / min. The wetting index was 46 dyn / cm (JIS-K6768).

(3) Preparation of antifogging composition dispersion (antifogging agent composition) Using water and isopropyl alcohol as a dispersion medium, synthetic resin (A), inorganic particles (B), and inorganic particles (C) are shown in Table 1. The dispersion was prepared by adjusting the solid content concentration to 10% by mass and water: isopropyl alcohol = 60: 40 (mass ratio).

<Materials used for antifogging composition>
<Synthetic resin (A)>
Synthetic resin (A): “A-612” (hydrophobic acrylic resin) manufactured by NSC Japan
<Inorganic particles (B)>
Inorganic colloidal sol (B-1): “Snowtex 20L” manufactured by Nissan Chemical Industries, Ltd. (colloidal silica, peak value of particle size distribution: 65 nm)
Inorganic colloidal sol (B-2): “Snowtex ZL” manufactured by Nissan Chemical Industries, Ltd. (colloidal silica, peak value of particle size distribution: 125 nm)
<Inorganic particles (C)>
Inorganic colloidal sol (C-1): “Snowtex MP-2040” manufactured by Nissan Chemical Industries, Ltd. (colloidal silica, peak value of particle size distribution: 200 nm)
Inorganic colloidal sol (C-2): “Chihoster KE-W30” manufactured by Nippon Shokubai Co., Ltd. (colloidal silica, peak value of particle size distribution: 270 nm)
Inorganic colloidal sol (C-3): “Chihoster KE-W50” manufactured by Nippon Shokubai Co., Ltd. (colloidal silica, peak value of particle size distribution: 540 nm)

(4) Formation of coating film The base film of “(1)” is surface-treated by the method of “(2)”, and the dispersion of the antifogging composition of “(3)” is used with a # 8 bar coater. And applied. The coated film was kept in an oven at 80 ° C. for 1 minute to volatilize the liquid dispersion medium to form a layer of the antifogging composition.

  Each sample of the anti-fogging film which apply | coated the anti-fogging composition produced with the mixing | blending shown in Table 1 was used, and the following evaluation was performed.

<Evaluation method>
<Transparency>
The straight light transmittance at a wavelength of 555 nm of the antifogging film after coating was measured with a spectrophotometer (manufactured by Hitachi, U3500 type), and the results are shown in Table 1.
<Haze>
The haze value of the antifogging film after coating was measured with a haze meter (manufactured by Tokyo Denshoku Co., Ltd .: TC-H3DP), and the results are shown in Table 1.
<Anti-fogging property>
An anti-fogging film was placed on the top of the water tank containing the anti-fogging composition facing the inside of the water tank, and the outside temperature was set to 23 ° C and the water temperature in the water tank was set to 50 ° C. Then, on the upper part of the water tank containing water, the surface side coated with the antifogging composition is directed to the inside of the water tank, and the antifogging film is arranged at an angle of 10 degrees with respect to the surface horizontal plane, the outside air temperature is 12 ° C The temperature in the water tank was kept at 22 ° C., and the time until the water droplets started to flow was measured.
Moreover, the obtained results were evaluated according to the following criteria, and the results are shown in Table 1.
○: Time until water droplets start to flow is 240 minutes or less.
X: The time until the water droplet starts flowing is longer than 240 minutes.
<Blocking prevention>
A sample obtained by collecting a 10 cm square sample from the obtained antifogging film was used, and the sample was placed in a temperature-controlled room maintained at 50 ° C. so that the surfaces of the coatings were in contact with each other. 1 cc of water was included so that the water spread evenly between them. In this state, a load of 150 kg per 100 cm ² is applied and the film after being left for one month in a constant temperature room at 50 ° C. is cut into 2.5 cm × 10 cm in a state where the films are stacked, and the two films are cut in the longitudinal direction. Using a tensile tester described in JIS-K6732, the T-peel strength was measured at a test speed of 500 mm / min and a temperature of 23 ° C. The results are shown in Table 1.
<Measurement method of peak value of particle size distribution>
The photograph which expanded the particle | grains with the scanning electron microscope (Nippon FEI company: NovaNanoSEM) was image | photographed, and the analysis of a photographic image was then based on this photograph using image analysis software (Nippon Roper company: Image-Pro Premier). By removing noise in the image and using a plurality of photographic images, arbitrarily select 2000 particles, and using the obtained particle size data, the horizontal axis represents the particle size and the vertical axis represents the volume. A histogram based on the above was created, a volume-based particle size distribution was determined, and a peak position was determined.
<Content of inorganic particles of 150 nm or more>
From the histogram of the inorganic particles obtained by the method for measuring the peak value of the particle size distribution, the ratio of the volume value having a particle size of 150 nm or more was determined from the total content of the inorganic particles and calculated from the total content of the inorganic particles.

  From the results of Examples 1 to 7, the antifogging film coated with the composition containing the blended amount of the inorganic particles defined in the present invention is excellent in performance to suppress blocking, and is excellent in transparency and antifogging properties. It became. On the other hand, since Comparative Example 1 does not contain inorganic particles (C), it can be seen that the strength at the time of peeling is large and the blocking property is poor. Moreover, since the comparative example 2 has much content of the inorganic particle whose particle diameter is 150 nm or more, it turns out that it is inferior to transparency.

  As is clear from the above results, the antifogging composition defined in the present invention was excellent in antiblocking properties without impairing transparency and antifogging properties.

Claims (6)

It contains a synthetic resin (A) and an inorganic compound as main components, and the inorganic compound is an antifogging composition containing at least inorganic particles (B) and inorganic particles (C),
The inorganic compound has a multimodal particle size distribution having at least two peaks in the particle size distribution;
The peak of the particle size distribution of the inorganic particles (B) is in the range where the particle size is less than 150 nm,
The peak of the particle size distribution of the inorganic particles (C) is in the range where the particle size is 150 nm or more,
Content of the inorganic particle whose particle diameter is 150 nm or more is 0.01 mass% or more and 25 mass% or less with respect to the total mass of the solid component of the said antifogging composition. Composition.   2. The antifogging composition according to claim 1, wherein the peak of the particle size distribution of the inorganic particles (C) has a particle size in a range of 150 nm or more and 1000 nm or less.   The product of the peak value X (nm) of the particle size distribution of the inorganic particles (C) and the content Y (mass%) of the inorganic particles having a particle diameter of 150 nm or more with respect to the total mass of the solid components of the antifogging composition. The antifogging composition according to claim 1 or 2, wherein the certain value K is 10 or more and 8000 or less.   An anti-fogging film comprising a base film, wherein the layer made of the anti-fogging composition according to any one of claims 1 to 3 is provided on at least one side of the base film. .   The antifogging film according to claim 4, wherein the base film contains a polyolefin-based resin.   The antifogging film according to claim 4 or 5, wherein the film is used for agriculture.