JP2001226504A - Method for manufacturing antifogging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing an antifogging film having an antifogging layer on a substrate film comprising a thermoplastic resin. SOLUTION: This method for manufacturing an antifogging film comprises applying a substrate film continuously being fed from a substrate film forming device with a liquid containing an antifogging agent and forming a layer containing the antifogging agent therein by continuously removing a medium liquid contained in the applied antifogging agent containing liquid. Rolling of the substrate film should not be done before the application of the antifogging agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a so-called anti-fogging film having a layer of an anti-fogging agent on a substrate film made of a thermoplastic resin.

[0002]

2. Description of the Related Art Conventionally, an antifogging film in which a layer of an antifogging agent is formed on a substrate film made of a thermoplastic resin is first manufactured by an inflation method or a calender method, and then rolled. It is manufactured by a method in which the base film roll is loaded into an anti-fogging agent application device, and then unwound and the anti-fogging agent is applied.
As a method of applying the anti-fog agent, a gravure method, a spray method, a dipping method and the like are known.

[0003]

However, in the above-mentioned conventional method, in order to load the wound roll-shaped base film into the anti-fogging agent coating device, the base film is formed using a machine such as a forklift or a crane. The roll of material film must be transported, and the roll must be loaded in the correct location and orientation in the anti-fog application. Further, in such a method, a portion where the anti-fogging agent is not applied is always generated in the lead portion of the base film roll, and this leads to a decrease in the yield of the anti-fogging agent applied product to the base film. . Further, a space for storing rolls of the base film is also required. The object of the present invention is
An object of the present invention is to provide a method capable of producing an antifogging film as described above with high productivity.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, after discharging the plasticized thermoplastic resin from the die of the molding machine, Until finally obtaining the anti-fogging film provided with the layer of the above, at least the formation of the base film and the formation of the anti-fogging layer should be continuously performed without winding the film in the middle As a result, it has been found that the above object can be achieved, and the present invention has been completed.

That is, the present invention relates to a method for producing an anti-fogging film comprising a layer of a base film made of a thermoplastic resin and a layer containing an anti-fogging agent, wherein (1) A step of continuously discharging a plastic resin from a die of a molding machine to form a base film, and (2) a step of applying a liquid containing an anti-fogging agent to at least one surface of the base film sent from the die. And (3) forming a layer containing the antifogging agent by removing the medium liquid from the antifogging agent-containing liquid applied to the base film. According to this method, an antifogging film in which a layer containing an antifogging agent is formed on a thermoplastic resin base film can be efficiently produced with excellent productivity.

In the above method, the base film can be subjected to a corona treatment prior to the application of the antifogging agent-containing liquid, so that the surface tension of the base film is 36 dyne / cm or more. According to this method, repelling of the antifogging agent-containing liquid can be prevented, and the antifogging agent-containing liquid can be uniformly applied without unevenness,
An anti-fogging film of excellent quality can be efficiently obtained.

Further, in the above method, in the step of forming the base film, a tubular base film is formed by an inflation molding method, and in the step of applying the antifogging agent-containing liquid, the tubular base film is subjected to antifogging. It can be immersed in the agent-containing liquid. According to this method, a wide antifogging film can be efficiently produced.

Further, the above-mentioned method comprises a step of further applying a liquid containing an antifogging agent to the surface of a layer containing an antifogging agent formed by removing the liquid medium, and The method may further include a step of removing the liquid to form a layer containing an antifogging agent. According to this method, an anti-fogging film having excellent anti-fogging property can be efficiently produced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the method of the present invention, first, a plasticized thermoplastic resin is discharged from a die of a molding machine to form a base film.

As the thermoplastic resin for the base film,
Polyolefin resin, polyvinyl chloride, vinyl chloride / methyl methacrylate copolymer, chlorine-containing resin such as polyvinylidene chloride, polyester resin such as polyethylene terephthalate and polyethylene naphthalate, acrylic resin such as polymethyl methacrylate, fluorine-containing resin, Polycarbonate resins and the like are exemplified, and polyolefin resins suitable for inflation molding are particularly preferable.

Examples of the polyolefin resin include α-olefin homopolymers or copolymers, and copolymers of α-olefins containing α-olefins as main components and heterogeneous monomers. , Polypropylene, ethylene / propylene copolymer, ethylene / butene-1 copolymer, ethylene / 4-methyl-1-pentene copolymer, ethylene / hexene-1 copolymer, ethylene / octene-1 copolymer, etc. Ethylene / α-olefin copolymer, and ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methyl methacrylate copolymer, ethylene / acetic acid wherein the different monomer is a polar vinyl monomer Examples thereof include a vinyl / methyl methacrylate copolymer and an ionomer resin. These thermoplastic resins may be used alone or in combination of two or more.

In particular, the polyolefin resin used for the base film for the antifogging flexible film has a density of 0.93.
5 g / cm ³ or less of low density polyethylene or ethylene /
α-olefin copolymers and ethylene / vinyl acetate copolymers having a vinyl acetate content of 30% by weight or less are preferred in terms of transparency, flexibility and cost of the base film.

Various additives can be added to the thermoplastic resin for the base film depending on the performance required for the product. Such additives include, for example, infrared absorbers exemplified below. Infrared absorbers: lithium aluminum composite hydroxide, composite hydroxides such as hydrotalcite compounds, magnesium oxide, calcium oxide, aluminum oxide, silicon oxide,
Oxides of metals such as titanium oxide, hydroxides such as lithium hydroxide, magnesium hydroxide, calcium hydroxide and aluminum hydroxide, magnesium carbonate, calcium carbonate, and basic aluminum carbonate (for example, JP-A-9-279)
Carbonates such as basic aluminum carbonate double salt described in JP-A-131, sulfates such as potassium sulfate, magnesium sulfate, calcium sulfate, zinc sulfate and aluminum sulfate, lithium phosphate, sodium phosphate, potassium phosphate, calcium phosphate, and phosphoric acid Zirconium (for example, see JP-A-8-6)
Phosphates such as H-type zirconium phosphate described in JP-A-7774, silicates such as magnesium silicate, calcium silicate, aluminum silicate and titanium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, and aluminosilicate Aluminosilicates such as sodium, potassium aluminosilicate and calcium aluminosilicate; clay minerals such as kaolin, clay and talc; inorganic infrared absorbers such as composite oxides; polyacetals, polyvinyl alcohol and its derivatives, ethylene / vinyl alcohol copolymer Organic infrared absorbers such as coalescence. In order to improve the dispersibility in the thermoplastic resin, the inorganic infrared absorber may be subjected to a surface treatment with, for example, a higher fatty acid or an alkali metal salt of a higher fatty acid.

[0014] Additives other than the above infrared absorbers include
Examples include surfactants, light stabilizers, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, colorants, flame retardants, and the like. These additives may be used alone or in combination of two or more. In order to enhance the initial antifogging property of the antifogging film, it is particularly preferable to add a surfactant. The additives can be blended into the thermoplastic resin for the base film by a conventional method using a mixer such as a Banbury mixer, a super mixer, a kneader, a single-screw extruder, or a twin-screw extruder.

The base film to be formed may have a single-layer structure or a multilayer structure including two or more layers. In the case of a base film having a multilayer structure, the layer structure is not particularly limited, and examples thereof include three types, three layers, three types, five layers, four types, five layers, and five types, five layers. Base film is 3
When it consists of more than one layer, the total thickness of both surface layers of the substrate film is usually 10 to 90% of the total thickness of the substrate film, preferably 20 to 80%, more preferably 30 to 70%. When a large amount of the above-mentioned infrared absorbent is blended in a layer other than the surface layer of the base film, the total thickness of both surface layers of the base film is usually 10% of the total thickness of the base film.
-40% is preferable, and 15-30% is more preferable. Note that the thicknesses of these two surface layers may be the same or different.

The method for forming such a base film is not particularly limited as long as it is a method generally used for processing a thermoplastic resin into a film. For example, a thermoplastic resin plasticized in a plasticizing device such as a single-screw extruder or a twin-screw extruder is discharged into a tubular shape from an annular slit at the tip of a die of a molding machine connected to the plasticizing device. Is blown into the tube while pulling up in the vertical direction, the film is stretched at a predetermined magnification, and then cooled and solidified. When a wide base film is obtained, such an inflation molding method can be preferably used. Further, a calender method can be used for forming the base film. The calendering method is a method of cooling and solidifying a plate-like film or sheet discharged from a linear slit at the tip of a die by contacting the roll with several rolls, thereby providing a substrate film having excellent surface smoothness. Can be obtained. When a base film having a multilayer structure is formed, for example, a multilayer blown film forming machine or a multilayer calender forming machine may be used in the method exemplified above.

According to the present invention, an antifogging agent-containing liquid is continuously applied to a substrate film continuously fed from a substrate film forming apparatus, and further included in the applied antifogging agent-containing liquid. It is characterized in that the medium liquid to be removed is continuously removed to form an antifogging agent-containing layer on the substrate. That is, the present invention is characterized in that the winding step of the base film is not performed before the application of the antifogging agent-containing liquid. Such a method of the invention comprises:
Compared to a method of once winding the base film before applying the anti-fogging agent-containing liquid, the yield is reduced due to occurrence of lead loss of the base film in the applying step of the anti-fogging agent-containing liquid, and the base film Storage space can be eliminated.

The application of the antifogging agent-containing liquid to the base film is performed by:
It can be performed by various methods capable of applying the antifogging agent-containing liquid on at least one surface of the base film, for example,
A gravure method, a spray method, a dipping method, or the like can be applied. In particular, as the double-side coating, as described in “Convertec” issued by the Processing Technology Research Institute, April 1999, a sequential double-side coating method of coating and drying one side at a time and a simultaneous double-side coating method can be mentioned. The simultaneous double-side coating method is economically advantageous and preferred. Simultaneous double-side coating methods include gravure reverse method, Meyer bar method, kiss reverse method, slit die method corresponding to horizontal dryer, and dipping plus Meyer bar method, dipping plus squeeze method corresponding to vertical dryer, reverse Roll method, slit die method, or JP-A-7-195028
There is a brush roll method disclosed in Japanese Patent Application Laid-Open Publication No. H10-15095, and in the production of a wide-width anti-fog film, a dipping plus Meyer bar method which can simultaneously apply both sides of a folded tubular film is preferable. With the dipping plus Meyer bar method, the film is pulled up vertically through the antifogging agent-containing liquid stored in the tank, and is placed horizontally on two Meyer bars before entering the dryer from both sides of the film. This is a method of applying a liquid to a predetermined thickness by removing excess liquid in a stiff manner. The coating thickness of the antifogging agent-containing liquid can be adjusted by the wire diameter of the Meyer bar.

In the method of the present invention, a step of removing the medium liquid from the antifogging agent-containing liquid applied to the base film is performed. This step can be performed, for example, by guiding the base film coated with the antifogging agent-containing liquid into a dryer and evaporating the medium liquid with warm air. By removing the medium, a layer containing an antifogging agent, that is, a so-called antifogging layer can be formed on the base film. When the antifogging agent-containing liquid is applied to only one surface of the substrate film, the dryer is preferably of a horizontal type in which warm air is blown only from the upper surface of the substrate film. When the antifogging agent-containing liquid is applied to both sides of the substrate film, a vertical type in which warm air is blown from both sides across the substrate film is preferable. The length of the dryer is appropriately determined according to the amount of the medium liquid to be removed, the transpiration, the line speed and the residence time. The temperature inside the dryer is preferably lower than the melting point of the thermoplastic resin constituting the base film. The melting point at this time refers to the melting peak temperature of the thermoplastic resin measured by the DSC method, and when a plurality of types of thermoplastic resins constituting the base film are used, the lowest temperature among them is used. The melting point is called the melting point in this case. When the temperature of the dryer is higher than the melting point, the base film is significantly softened,
Due to the deformation, the tension of the base film may fluctuate, which may cause uneven coating or contact trouble in the dryer. Furthermore, it is not preferable because the base film may be melted and adhered to the roll or cut. In addition, the wind speed of the dryer is such that if the wind is too strong, the anti-fogging agent-containing liquid may be scattered, the base film may flap and wrinkles may occur, or the base film may come into contact with the wall surface at the entrance of the dryer. Therefore, the wind speed is desirably 30 m / sec or less, particularly preferably 25 m / sec or less.

In order to improve the applicability of the antifogging agent-containing liquid to the substrate film, it is preferable to subject the surface of the substrate film to corona treatment before applying the antifogging agent-containing liquid. The strength of the corona treatment can be controlled by adjusting the output energy of the corona discharge according to the traveling speed of the base film, and the treatment is performed so that the surface tension of the base film becomes 36 dyne / cm or more. It is preferable that the surface tension of the substrate film is 46 dyne / cm, particularly when the antifogging agent-containing liquid having a high surface tension is applied.
Preferably, the treatment is performed as described above.

In the method of the present invention, an antifogging agent-containing liquid is further applied on the antifogging layer formed on the base film, and the medium liquid is removed to form a new antifogging layer. Can be. This step of additionally forming an anti-fogging layer can be repeated a plurality of times as necessary. By repeatedly forming the anti-fogging layer in this manner, an anti-fogging film having excellent durability of the anti-fogging property can be produced.

The antifogging agent-containing liquid used in the method of the present invention is a liquid containing an antifogging agent in a medium liquid (solvent or dispersion medium). By removing, an antifogging layer containing an antifogging agent can be formed. Examples of antifogging agents include, for example,
No. 9-32668, JP-B-50-11348 and the like, an antifogging agent containing an inorganic oxide colloid (for example, colloidal silica or colloidal alumina) as a main component, and JP-A-63-150369. , Tokubo Sho 63-
No. 45717, JP-B 64-2158, JP-A-3-207643 and JP-B-8-319476 and inorganic oxide colloids and organic compounds (for example, surfactants, hydrophilic resins, hydrophobic resins). An antifogging agent composed of a mixture with a hydrophilic resin, an antifogging agent containing a surfactant as a main component, an antifogging agent containing a hydrophilic resin as a main component, and the like are preferably used. Preferred hydrophilic resins include polyvinyl alcohol, polysaccharides, polyacrylic acid and the like. In order to maintain a stable antifogging property for a long period of time outdoors, an antifogging agent containing an inorganic oxide colloid as a main component is preferable. Further, water is preferable as the medium liquid from the viewpoint of the environment.

In the method of the present invention, the thickness of the antifogging layer formed by removing the medium liquid from the antifogging agent-containing liquid is determined based on the unit area (1 m) of the base film from the viewpoint of antifogging property and scratch resistance.
² ) The weight per unit is preferably 0.01 g / m ² or more,
0.02 g / m ² or more is more preferable, and 0.05 g / m ²
The above is particularly preferred. From the viewpoint of transparency of the antifogging layer is preferably 10 g / m ² or less, more preferably 2 g / m ² or less, 0.5 g / m ² or less is particularly preferred.

In the method of the present invention, the thickness of the antifogging film to be produced can be appropriately selected according to the properties such as mechanical strength, transparency and flexibility required for the film. When used as a coating film for a pipe house or steel frame house, usually 10 to 4
The thickness is set to 00 μm, preferably 30 to 300 μm.

As described above, according to the method of the present invention, the antifogging agent-containing liquid is continuously applied to the base film continuously fed from the base film forming apparatus, and the applied antifogging agent is further applied. It is characterized in that the medium liquid contained in the fogging agent-containing liquid is continuously removed to form an antifogging agent-containing layer on the substrate. For this reason, the method of the present invention is usually carried out using an apparatus in which a coating apparatus for the antifogging agent-containing liquid is arranged after the film forming machine, and a winding machine is arranged on the downstream side.

Further, according to the method of the present invention, in many cases, excellent coating properties of the antifogging agent-containing liquid can be achieved as compared with the conventional method, and the adhesive strength of the antifogging layer can be further improved. A high antifogging film can be obtained. In the conventional method of once winding the base film before applying the anti-fogging agent-containing liquid, the application of the anti-fogging agent-containing liquid often causes repelling or uneven application of the liquid. As a result, the state of the formed anti-fog layer was uneven. Even if the liquid could be applied, the adhesive strength between the formed anti-fogging layer and the base film was low, and the anti-fogging layer was easily peeled off. Furthermore, the effect of the corona treatment for improving the coating property of the antifogging agent-containing liquid may be impaired. Such a phenomenon is remarkably exhibited when a migrating additive such as a surfactant is blended in the base film, and the oligomer generated during the production of the thermoplastic resin constituting the base film. Also caused by such. According to the method of the present invention, since the formed base film is subjected to the application step of the antifogging agent-containing liquid without being wound, even if the base film contains migrating additives or oligomers. Also, excellent coating properties of the anti-fogging agent-containing liquid can be achieved without causing the above-mentioned inferior phenomenon, and an anti-fogging film having a high adhesive strength of the anti-fogging layer can be obtained.

The antifogging film produced in this manner is usually wound into a roll after being subjected to a cutting step as required.

The method of discharging the thermoplastic resin from the die of the molding machine and forming the antifogging layer on the base film obtained by stretching as required has been described above. Discharging the thermoplastic resin from the die of the molding machine, forming a base layer by forming a new layer by an appropriate method such as lamination or coating on the film obtained by stretching if necessary, An embodiment in which an antifogging layer is formed thereon is also included in the present invention. In the case where a plurality of antifogging layers are formed, an embodiment in which a layer other than the antifogging layer is formed between the antifogging layers by an appropriate method is also included in the present invention.

[0029]

According to the method of the present invention, the antifogging layer is formed without performing an intermediate film winding step between the formation of the base film and the winding of the completed antifogging film. Therefore, it is possible to omit the storage and transportation of the base film roll and the loading into the anti-fogging agent application device, which are required in the conventional method, and it is possible to produce an anti-fogging film with extremely high productivity. In addition, even when the base film contains an additive having a high migration property such as a surfactant or an oligomer generated during the production of a thermoplastic resin as a raw material thereof, the antifogging layer is formed without unevenness. Can be
An antifogging film having a high adhesion strength of the antifogging layer can be obtained.

[0030]

The present invention will now be described by way of examples, which should not be construed as limiting the invention. Example 1 [1] Preparation of Antifogging Agent-Containing Liquid (A) Aqueous dispersion of colloidal alumina (trade name: alumina sol 520; solid content = 20% by weight; particle diameter = 20) with respect to water
9.000 parts by weight, aqueous colloidal silica dispersion (trade name: Snowtex 20; solid content = 20% by weight; particle diameter = 20 nm; manufactured by Nissan Chemical Industries)
2.400 parts by weight, 0.090 parts by weight of synthetic smectite (trade name: Smecton SA; manufactured by Kunimine Industries), 0.014 parts by weight of sodium caprylate (anionic surfactant), 0.002 parts of sodium p-toluenesulfonate By weight, 100.000 parts by weight of the antifogging agent-containing liquid was obtained. This is referred to as antifogging agent-containing liquid (A).

[2] Preparation of Antifogging Agent-Containing Liquid (B) Polyvinyl alcohol (degree of polymerization = 300; degree of saponification = 8)
94% by weight of a 1% by weight aqueous solution of 0 mol%;
6 parts by weight of an aqueous dispersion of colloidal silica (density = 2.2 g / cm ³ ) (trade name: Snowtex ZL; solid content = 40% by weight; particle diameter = 100 nm; manufactured by Nissan Chemical Industries) are mixed and prevented. 100 parts by weight of a clouding agent-containing liquid were obtained. This is referred to as antifogging agent-containing liquid (B).

[3] Preparation of resin composition for base film 87.0 parts by weight of ethylene / vinyl acetate copolymer (trade name: Evatate H2031; vinyl acetate content = 19% by weight; MFR = 1.5 g / 10) Min; melting point = 85 ° C .; manufactured by Sumitomo Chemical Co., Ltd.), 12.0 parts by weight of lithium aluminum composite hydroxide (trade name: Mizukarac; manufactured by Mizusawa Chemical Industry), 0.6 parts by weight of Tinuvin 622-LD (trade name) ;
0.2 parts by weight of Chimassorb 944-LD (trade name; hindered amine compound manufactured by Ciba Specialty Chemicals) and 0.2 parts by weight of antioxidant (trade name: Irganox 1010; Ciba) Specialty Chemicals) at 130 ° C for 5 minutes using a Banbury mixer.
After kneading for a minute, the mixture was granulated by a granulator to obtain pellets of the resin composition. This resin composition is referred to as resin composition (1). Next, 99.34 parts by weight of an ethylene / vinyl acetate copolymer (trade name: Evatate D2011; vinyl acetate unit content = 5% by weight; MFR = 0.5 g / 10 minutes; melting point = 101 ° C .; Sumitomo Chemical Co., Ltd.) ), 0.60 part by weight of Tinuvin 622-LD and 0.06 part by weight of Irganox 1010 were kneaded at 130 ° C for 5 minutes using a Banbury mixer, and then granulated by a granulator to obtain a resin composition. A pellet was obtained. This resin composition is referred to as resin composition (2). Furthermore, 99.01 parts by weight of low-density polyethylene (trade name: Sumikacene F208; density = 0.923 g /
cm ³ ; MFR = 1.5 g / 10 min; melting point = 114 ° C .;
Sumitomo Chemical Co., Ltd.), 0.60 parts by weight of Tinuvin 622
LD, 0.06 parts by weight of Irganox 1010,
0.28 parts by weight of an ultraviolet absorber (trade name: Sumisorb 1)
30; manufactured by Sumitomo Chemical Co., Ltd.) and 0.05 parts by weight of oleic amide (lubricant) at 130 ° C. using a Banbury mixer.
After kneading for 5 minutes, the mixture was granulated by a granulator to obtain pellets of the resin composition. This resin composition was used as a resin composition (3)
Called.

Production of Antifogging Film The following steps were continuously performed. (1) Formation of a base film Using a three-layer blown film molding machine, a temperature of 1
From the resin compositions (1) to (3) plasticized at 50 ° C., a tube-shaped base film laminated in the order of the first layer, the second layer, and the third layer from the outside is formed, and The sheet was picked up at a picking speed of 8.9 m / min and folded in two through a nip roll. The first layer was the resin composition (2), the second layer was the resin composition (1), and the third layer was the resin composition (3). The thickness ratio of each layer (first layer: second layer: third layer) is 1
7.5: 65.0: 17.5, and the total thickness of the three layers was about 150 μm. The width of the two-fold base film was about 427 cm.

(2) Corona Treatment Next, the outer surface (the surface of the first layer) of the two-folded base film was subjected to corona treatment at a watt density of 25 W · min / m ² . Thereby, the surface tension of the first layer surface is 4
It was 8 dyne / cm.

(3) Application of Antifogging Agent-Containing Liquid (A) Next, the corona-treated two-fold base film was immersed in the antifogging agent-containing liquid (A) filled in the tank. Thereafter, this is lifted up, passed through between two Meyer bars having a wire diameter of 1.5 mmφ to remove excess liquid, and has a thickness of 10 g / m ^{2 in} weight per unit surface area (1 m ² ) of the base film. An agent-containing liquid layer was formed.

(4) Removal of Medium Fluid from Antifogging Agent-Containing Liquid (A) The antifogging agent-containing liquid (A) of (3) is applied in a dryer in which warm air at 60 ° C. is blown at a wind speed of 18 m / sec. The medium liquid was removed while passing the substrate film through the dryer upward, and an antifogging layer having a thickness of about 0.2 μm was formed on the two-folded base film. This anti-fog layer is referred to as anti-fog layer (A).

(5) Application of antifogging agent-containing liquid (B) In the antifogging agent-containing liquid (B) filled in the tank, the antifogging layer (A)
After passing through the two-fold film having the above, the film is pulled up, further passed between two Meyer bars having a wire diameter of 1.5 mm to remove excess liquid, and the unit surface area of the film (1
A layer of the antifogging agent-containing liquid (B) having a thickness of 10 g / m ^{2 by} weight per m ² ) was formed.

(6) Removal of Medium Fluid from Antifogging Agent-Containing Liquid (B) The above-mentioned two-layer coating composition in which the antifogging agent-containing liquid (B) was applied in a dryer in which hot air at 60 ° C. was blown at a wind speed of 18 m / sec. The medium liquid was removed while passing the inside of the dryer upward through the folded film to form an antifogging layer on the antifogging layer (A). This new anti-fog layer is referred to as anti-fog layer (B).

(7) Winding One end of the two-folded film having the anti-fog layer (A) and the anti-fog layer (B) is slit by about 7 cm and the folding width is 420
cm and a length of 300 m wound around a 3-inch diameter paper roll to obtain a product. The opening width of this product was 840 cm. Table 1 shows the evaluation results of the obtained antifogging film.

(Embodiment 2) Instead of resin composition (1)
Of ethylene / vinyl acetate copolymer (H2031)
1.0 part by weight of 1.0 part by weight of liquid surfactant (commodity
Name: Denone STO277; Marubishi Yuka, diglycerinse
Resin composition (1) except that
Resin composition (1 ') having the same composition as
Instead of (2), an ethylene / vinyl acetate copolymer (D
2011) by 1.0 part by weight of the liquid surfactant
Agent (trade name: Denon STO277; Marubishi Yuka, jig
Resin group except that it was replaced with lysine sesquioleate)
After using the resin composition (2 ') having the same composition as the composition (2),
Other than that, an antifogging film was prepared in the same manner as in Example 1, and
This was evaluated.

(Comparative Example 1) An antifogging film was produced by the following procedure using the same resin composition as used in Example 2. A two-fold base film formed from a plasticized thermoplastic resin was wound up to a length of 300 m. One month later, the base film roll was loaded into a feeding device, and then subjected to corona treatment, application of the antifogging agent-containing liquid (A), and removal of the medium liquid from the antifogging agent-containing liquid (A). I took it.
At this time, in the wound film, the portion where the antifogging layer (A) was formed was 280 m excluding the loss at the beginning and end.
Minutes. Further, a film roll having only the antifogging layer (A) stored for one week is loaded into a feeding device, and the application of the antifogging agent-containing liquid (B) and the removal of the medium liquid from the antifogging agent-containing liquid (B) are performed. Then, slit one end about 7cm and set the folding width to 42
After being set to 0 cm, it was rolled up to obtain a product. The effective part of the product as an antifogging film was 250 m excluding the loss at the beginning and end. The yield with respect to the base film formed in the first step was 83%. Table 1 shows the evaluation results of the obtained antifogging film. In this example, at the time of coating the antifogging agent-containing liquid, repelling and unevenness occur,
Since the adhesion strength of the anti-fogging layer after storage was reduced and the state of formation of the anti-fogging layer was uneven, the anti-fogging property of the product was insufficient.

[0042]

[Table 1]

The method for evaluating the antifogging film is as follows. [1] Coatability of antifogging agent-containing liquid ○: The antifogging agent-containing liquid was not repelled, and the liquid was fixed without unevenness. ×: The antifogging agent-containing liquid was repelled, and there was a portion where the liquid did not fix.

[2] Adhesion between base film and antifogging layer (A) A cellophane tape is attached to the surface of antifogging layer (B) of the antifogging film with a hand roller, and The cellophane tape was peeled off at a speed of 200 mm / min in the direction of 90 °. The peeling state of the antifogging layer immediately after the production and after storage for one month in an atmosphere of 60 ° C. and 90% RH was confirmed, and was judged according to the following criteria. ：: The anti-fog layer (A) did not peel off from the base film. ×: The antifogging layer (A) was peeled off from the substrate film.

[3] Antifogging property An antifogging film was stuck on an acrylic frame measuring 34 cm in length and 5 cm in width with a double-sided tape, and a test surface was placed on a constant temperature water tank placed in a test room having a constant temperature. 1 against the horizontal plane
It was installed with an inclination of 5 degrees. The temperatures of the test room and the thermostatic bath were 23 ° C. and 40 ° C., respectively. The state of the test surface at the beginning of the test and one month after the continuation of the test was observed, and judged based on the following criteria. A: The test surface was almost uniformly wet. ：: Water droplets were partially adhered to the test surface. Δ: Water droplets adhered to the entire test surface and were white and cloudy.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D075 BB48X CA39 DA04 DB31 4F006 AA12 AA13 AA55 AB20 AB66 AB69 AB74 AB76 BA10 DA00 DA04 EA03

Claims (4)

[Claims] 1. A method for producing an antifogging film comprising a layer of a base film made of a thermoplastic resin and a layer containing an antifogging agent, wherein (1) molding a plasticized thermoplastic resin. (2) a step of applying a liquid containing an anti-fogging agent to at least one side of the substrate film sent from the die; A method comprising the step of removing a medium liquid from a liquid containing an antifogging agent applied to a base film to form a layer containing an antifogging agent. 2. Prior to the application of the antifogging agent-containing liquid, the substrate film is subjected to a corona treatment to reduce the surface tension of the substrate film to 36.
The method according to claim 1, wherein dyne / cm or more is used. 3. A step of forming a base film, the step of forming a tube-shaped base film by an inflation molding method, and the step of applying a liquid containing an anti-fogging agent, the step of coating the base film in an anti-fogging agent-containing liquid The method according to claim 1, wherein the immersion is performed. 4. A step of further applying a liquid containing an antifogging agent to the surface of the layer containing an antifogging agent formed by removing the medium liquid, and removing the medium liquid from the applied liquid containing the antifogging agent. The method of claim 1 further comprising the step of forming a layer comprising the antifogging agent.