JP2711857B2 - Anti-fog insulation sheet - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet having an antifogging property and a heat insulating property, and particularly to a window glass and the like for preventing dew condensation and the like caused by a temperature difference between indoor and outdoor. The present invention relates to an anti-fogging heat insulating sheet to be attached to a sheet.

[Problems to be solved by conventional technology and invention]

When a large temperature difference occurs between the inside and outside of a room in winter or the like, a phenomenon in which dew condensation occurs on the inside of a room occurs in a window glass having no heat insulating effect. If the environment in which such dew condensation occurs continues for a long time, the water droplets generated by the dew condensation become drips, and water pools are formed on the crosspieces and rails of the windows. Problems such as hindering opening and closing occur.

In order to prevent dew condensation which causes such a problem, various films and sheets are known which reduce the temperature difference between the indoor temperature and the surface temperature of the window glass on the indoor side due to a heat insulating effect.

By installing these conventional heat-insulating films and sheets on the indoor side, such as window glass, it is possible to prevent condensation for a time, but there are limitations in terms of window opening / closing function, transparency, and visibility. Therefore, the film thickness and the material are limited. Therefore, when the temperature difference between the inside and outside of the room is large, a sufficient heat insulating effect cannot be obtained, and fine water droplets (clouding) are generated on the indoor side surface, which causes a problem that transparency and visibility are remarkably reduced.

In addition, this type of dew condensation preventing film and sheet also has a problem that dust and dirt on the surface are easily attached due to generation of static electricity.

In view of the above problems, an object of the present invention is to solve the above-mentioned problems of the prior art, prevent the generation of fine water droplets (clouding) due to dew condensation, and provide an antifogging heat insulating sheet excellent in antifouling properties. To provide.

[Means for solving the problem]

As a result of intensive studies in view of the above object, the present inventors have discovered that a hydrophilic film may be formed on the surface of a heat insulating film or sheet, and have reached the present invention.

That is, the first anti-fog sheet of the present invention is a hydrophilic heat-crosslinked film formed by electron beam irradiation on the surface of a transparent heat-insulating film or sheet provided with a core material forming an air layer between two flat transparent films. A conductive film is formed.

Further, the second anti-fogging sheet of the present invention is a transparent heat-insulating film obtained by laminating a flat transparent film on a convex portion of a transparent film having irregularities on one side or a hydrophilic cross-linked by electron beam irradiation on the surface of the sheet. A conductive film is formed.

Further, the third antifogging sheet of the present invention is characterized in that a hydrophilic film crosslinked by electron beam irradiation is formed on the surface of the heat ray reflective film or sheet.

 The present invention will be described in detail below.

Examples of the heat insulating film or sheet used in the present invention include (a) a film having a low thermal conductivity layer, and (b) a film having a heat insulating effect by reflecting or blocking heat rays (infrared rays). it can.

As the former low thermal conductivity layer, a gas layer can be mentioned, and an air layer is particularly optimal in terms of cost.

Examples of the heat insulating sheet having the low thermal conductivity layer (a) include those shown in FIGS. 1 to 4. FIG. 1 shows a structure in which a core material 3 is provided in a striped manner between two flat transparent films 1 and 2 and a hydrophilic film 5 is formed on a heat insulating sheet having an air layer 4 formed therebetween. Show. FIG. 2 shows a heat insulating sheet in which a corrugated or accordion-like film 13 is laminated between two flat films 11 and 12, and a hydrophilic film 15 is formed on a heat insulating sheet on which an air layer 14 is formed. FIG. 3 shows a heat insulating material in which a flat transparent film 22 is laminated on a convex portion 23 of a transparent sheet 21 made of a soft plastic and having regular uneven vertical stripes on one side to form an air layer 24. A sheet on which a hydrophilic film 25 is formed is shown. And the fourth
The figure shows a structure in which a mesh sheet 33 is laminated between two flat transparent films 31 and 32 and a hydrophilic film 35 is formed on a heat insulating sheet on which an air layer 34 is formed.

On the other hand, the heat insulating sheet using the sheet for reflecting or blocking the heat rays (b) has a structure shown in FIG. 5, for example. In FIG. 5, 41 is a so-called heat reflection film (sheet).
42 is a hydrophilic film. Examples of the heat reflection film (sheet) include the following.

Thin films (including vapor-deposited thin films) of metals such as titanium, silver, aluminum, gold, platinum, zinc, and copper, as well as transparent materials such as metal alkoxide compounds, organotitanium compounds, and organosilicon compounds are formed on a film or sheet serving as a base material. A laminate in which a refractive index dielectric layer is laminated.

A laminate comprising a transparent thin film layer containing a specific metal or a metal thin film layer coated with a protective film layer of silicon oxide, and a transparent film such as a transparent plastic film such as polyester or polyethylene (Japanese Patent Laid-Open No. 57-14036) Reference).

A light-transmitting sheet made by laminating an organic polymer film on a Fabry-Perot filter that transmits only light of a specific wavelength.

These heat-insulating films or sheets are required to have transparency and visibility because the anti-fogging heat-insulating sheet of the present invention is mainly used for window glass, etc. When applied, transparency and visibility are not necessarily required.

The hydrophilic film in the present invention basically comprises a polymer in which a hydrophilic monomer or the like is cross-linked by irradiation with an electron beam and, where necessary, a surfactant is contained.
Specific combinations include (a) polymer + hydrophilic monomer, (b) polymer + hydrophilic monomer + surfactant, (c) polymer + hydrophilic monomer + crosslinking monomer, (d) polymer + hydrophilic monomer + Crosslinkable monomer + surfactant, (e) polymer + hydrophilic crosslinkable monomer, (f) polymer + hydrophilic crosslinkable monomer + surfactant, (g) polymerer + hydrophilic monomer + hydrophilic crosslinkable monomer, And (h) polymer + hydrophilic monomer + hydrophilic crosslinkable monomer + surfactant. In all of the above combinations, the polymer may be either a functional polymer or a non-functional polymer.

As will be described later, the surfactant does not need to be sufficiently added to the hydrophilic film from the beginning, and it is sufficient that the surfactant becomes a sufficient amount after the solution containing the surfactant is applied. It should be understood that the combination of the above (b), (d), (f), and (h) is as described above.

Non-functional polymers include polyacrylic acid alkyl ester, polymethacrylic acid alkyl ester, polyurethane, polyester, polyamide, polyvinyl acetate, polyvinyl chloride, polystyrene, polyacrylonitrile,
Polyvinylpyrrolidone and the like can be used.

A hydrophilic group may be previously introduced into the non-functional polymer in order to improve the compatibility with the hydrophilic monomer. This is a copolymer with a monomer having a hydrophilic group (hydrophilic monomer) described later. The ratio of the hydrophilic monomer to the non-functional polymer is 50 mol% or less, and when it exceeds this, the water resistance of the obtained film is reduced.

Furthermore, partially saponified polyvinyl alcohol, polyvinyl butyral, polyvinyl alcohol derivatives such as polyvinyl acetal, and cellulose derivatives such as nitrocellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and hydroxypropyl cellulose can also be used. .

On the other hand, the functional polymer is a polymer having a functional group that causes a crosslinking reaction by ionizing radiation, and examples of the functional group include the following.

The ratio of the functional group is desirably one in the molecular weight of 300 to 10,000 of the polymer. When the ratio is less than one per 10,000 molecular weight, there is almost no crosslinking effect by the functional group, and when the ratio exceeds one per 300 molecular weight, the crosslink density is higher. Is too high.

Examples of the functional polymer include urethane acrylate, polyester acrylate, epoxy acrylate and the like, and acrylic acid chloride or 2-hydroxyethyl acrylate and diisocyanate at the hydroxyl group of a copolymer of alkyl acrylate and 2-hydroxyethyl acrylate. A copolymer in which an acryloyl group is introduced by adding a 1: 1 adduct of acrylic acid, a copolymer in which glycidyl methacrylate is added to a carboxyl group of a copolymer of an alkyl acrylate and acrylic acid, and a residual polyvinyl butyral Acrylic acid chloride or acrylic acid-2 in hydroxyl group
A product obtained by adding a 1: 1 adduct of -hydroxyethyl and diisocyanate can be used.

The polymer may be in an oligomer form, but preferably has a molecular weight of 1,000 to 300,000 (weight average) from the viewpoint of film forming properties.

The hydrophilic monomer is a monomer containing a hydrophilic group such as a hydroxyl group, a carboxyl group (metal salt), an amide group, an imide group, a sulfone group, an ammonium base, and a phosphoric acid group. For example, 2-hydroxyethyl acrylate, methacrylic acid 2-hydroxyethyl, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, acrylic acid, methacrylic acid, metal acrylate, metal methacrylate, dimer acrylate, acrylamide, methacrylamide, dimethylaminopropylacrylamide, dimethyl Aminopropyl methacrylamide, N-acryloyl morpholine, N-methacryloyl morpholine, N-methylol acrylamide, N-methylol methacrylamide, t-butyl acrylamide, t-butyl methacrylamide, N- Butoxy methyl acrylamide, N- ethoxymethyl acrylamide, N-n-butoxy acrylamide, N, N- dimethylacrylamide, N, N- dimethylaminopropyl acrylamide, N, N
-Dimethylaminopropyl methacrylamide, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, glycerol monomethacrylate, 2-acrylamide 2-methylpropanesulfonic acid, methacrylamidopropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, mono (2-methacrylate) Chloroxyethyl) acid phosphate.

The crosslinkable monomer is a monomer having two or more groups that easily become a radical by electron beam irradiation, such as an acryloyl group, a methacryloyl group, an allyl group, and an epoxy group, and is crosslinked with any of the skeleton polymer and the hydrophilic monomer. Improve the overall crosslink density, increase the film strength, and keep unreacted hydrophilic monomers from remaining. As such a crosslinkable monomer, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate,
Glycidyl methacrylate, neopentyl glycol dimethacrylate, tetraethylene glycol dimethacrylate, 2,2-bis [4- (acryloxydiethoxy)
Phenyl] propane, 2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 2,2-bis [4-
(Acryloxypolyethoxy) phenyl] propane, 2,
Bifunctional monomers such as 2-bis [4- (methacryloxypolyethoxy) phenyl] propane, trifunctional monomers such as trimethylolpropane trimethacrylate, and other polyfunctional monomers such as tetramethylol methane tetraacrylate and dipentaerythritol hexaacrylate Is mentioned.

Hydrophilic crosslinkable monomers include hydroxyl groups, carboxyl groups (metal salts), amide groups, imide groups, sulfonic acid groups (metal salts), ammonium groups, phosphoric acid groups and other hydrophilic groups and acryloyl groups, methacryloyl groups, allyl groups, A monomer having two or more crosslinkable functional groups that easily become radicals upon irradiation with an electron beam such as an epoxy group.

Examples of such a hydrophilic crosslinkable monomer include, for example,
Those having a hydroxyl group such as glycerol di (meth) acrylate and glycerol methacrylate acrylate, ethylene glycol, diglycidyl ether di (meth) acrylate, polyethylene glycol / diglycidyl ether di (meth) acrylate, and polypropylene glycol / diglycidyl ether di (meth) ) Acrylate,
Diols such as neopentyl glycol diglycidyl ether di (meth) acrylate, glycerin diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and trimethylolpropane triglycidyl ether di (meth) acrylate 1: with glycidyl ether and acrylic acid
2 adducts, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate,
Pentaerythritol tri (meth) acrylate, dipentaerythritol mono (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) ) Pentaerythritol derivatives such as acrylate, methylenebis (meth) acrylamide, acrylamide / glyoxal adduct, acrylamide / methyloethylene urea condensate, 1,3,5-triacryloylhexahydros-triazine, N, N-diallylacrylamide, acrylamide. Methylol melamine condensate, acrylamide / methylol triazone condensate, acrylamide / methylol hydantoin condensate,
There are acrylamide derivatives such as acrylamide / methylol urea and N, N-diallylacrylamide.

The hydrophilic film used in the present invention can also contain a surfactant. The surfactant has an effect of imparting dew condensation preventing properties (anti-fogging properties) by gradually oozing out from the hydrophilic film to the surface. Any of anionic, nonionic and cationic surfactants can be used as long as they have good compatibility with the composition comprising the above components constituting the hydrophilic layer.

Examples of anionic surfactants include fatty acid salts, alkyl sulfate salts, alkyl benzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinate esters, alkyl phosphate esters, naphthalene sulfonic acid-formalin condensates, and polyoxyethylene. Alkyl sulfates, etc., and nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine Glycerin fatty acid esters, oxyethylene-oxypropylene block polymers, etc., and cationic surfactants include alkylamines and quaternary ammonium compounds. And the like.

When forming the hydrophilic film used in the present invention, the polymer 10
The hydrophilic monomer is added in an amount of 5 to 300 parts by weight per 0 parts by weight. If the amount is less than 5 parts by weight, sufficient hydrophilicity will not be imparted, and if it exceeds 300 parts by weight, the water resistance of the film will decrease.
The preferred content of the hydrophilic monomer is 20 to 250 parts by weight.

The crosslinking monomer is used in an amount of 1 to 300 parts by weight per 100 parts by weight of the polymer. When the amount is less than 1 part by weight, the unreacted hydrophilic monomer is insufficiently crosslinked, and when it exceeds 300 parts by weight, the crosslink density of the whole film becomes too high. Particularly when the polymer has no functional group, the content of the crosslinkable monomer is preferably from 5 to 300 parts by weight, more preferably from 5 to 200 parts by weight. When the polymer has a functional group, the content of the crosslinkable monomer is preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight.

The amount of the hydrophilic crosslinkable monomer is 1 per 100 parts by weight of the polymer.
~ 200 parts by weight. If the amount is less than 1 part by weight, sufficient hydrophilicity and crosslinking property cannot be imparted, and if it exceeds 200 parts by weight, the water resistance of the film decreases and the crosslink density becomes too high.
The preferred content of the hydrophilic crosslinkable monomer is 1 to 100 parts by weight.

Surfactants are not always necessary, but if added,
Not more than 200 parts by weight per 100 parts by weight of the polymer. If it exceeds 200 parts by weight, the surfactant will exude too much.
The preferred content is 1 to 100 parts by weight.

In the case of forming a hydrophilic film, a composition comprising an appropriate combination of the above components may appropriately contain a solvent. Solvents not only regulate the fluidity of the composition,
Since it also has the function of lifting the hydrophilic monomer on the surface of the coating film, it is preferable for forming the hydrophilic film of the present invention.
Examples of the solvent that can be used include alcohols such as methanol, ethanol, isopropanol, methyl cellosolve and ethyl cellosolve, ethers such as tetrahydrofuran, ketones such as methyl ethyl ketone, acetone and methyl isobutyl ketone, ethyl acetate and butyl acetate. Esters, toluene, aromatic hydrocarbons such as xylene, etc.,
Alternatively, there is a mixed solvent thereof.

The amount of the solvent to be added depends on the method of forming the film, but when the coating is formed by coating, the solid content in the composition is adjusted to 5 to 50% by weight, preferably 5 to 30% by weight. Generally, the amount of the solvent added is 6000 parts by weight or less per 100 parts by weight of the polymer.

Using the above composition, a hydrophilic film can be formed on a heat insulating film or sheet by the following method.

First, when the composition does not contain a solvent, the composition is adjusted to an appropriate viscosity by a method such as heating, and a gravure reverse method, a three-reverse method, a gravure direct method, and a four-reverse method such as a roll coat method. , Applied on a film. As the film, generally use a transparent plastic film, as a material, polyester, polyethylene, polypropylene, polycarbonate, polyacrylate, polystyrene, polyamide, polyimide,
Polyvinyl chloride or the like can be used.

After applying the composition to the film, the coated surface side is laminated on a heat insulating film or sheet and irradiated with an electron beam.

As an irradiation method, any method such as an electron curtain method and a beam scanning method can be used.
Irradiation with an electron beam enables the polymer to crosslink regardless of the presence or absence of a functional group, and the hydrophilic monomer and the hydrophilic crosslinkable monomer crosslink to the polymer in the form of graft polymerization or block polymerization. This is a remarkable difference from the crosslinking by irradiation with ultraviolet rays. The energy of the irradiated electron beam is 150-200
It is about keV, and the irradiation dose varies depending on the composition of the composition, the desired degree of crosslinking density, and the like. The smaller the amount of irradiation, the higher the functional group in the polymer, and the higher the amount of irradiation as the crosslink density is increased. In particular, when a surfactant is contained, if the crosslinking density is too high, the bleeding becomes insufficient, and the effect of preventing condensation (anti-fogging) is reduced. Therefore, the control of the irradiation amount is important.

From the above, the irradiation dose is generally 0.5 to 20 Mrad,
If it is less than 0.5 Mrad, unreacted monomers may remain. If it exceeds 20 Mrad, the crosslink density becomes too high.

After forming a hydrophilic film by irradiation with an electron beam, the film is peeled off, and the film is transferred to a heat insulating film or sheet. In addition, the film can be used as a protective film without being peeled off until construction.

Next, when the composition contains a solvent, after adjusting to an appropriate viscosity by dilution with a solvent or the like, a gravure reverse method,
It is applied on the surface of the heat insulating film or sheet by a roll coating method such as a three-reverse method, a gravure direct method, or a four-reverse method. The coating film of the composition formed on the heat insulating film or sheet is dried while heating with a dryer or the like in order to remove the solvent by evaporation. If the heating temperature is too high, problems such as evaporation of monomers and deformation of the heat insulating film or sheet occur.

Next, the coating film is irradiated with an electron beam in the same manner as described above to form a hydrophilic film on the heat insulating film or sheet. Depending on the application, a transparent plastic film may be laminated on the hydrophilic film to form a protective film.

When it is difficult to apply the composition on a heat insulating film or sheet, the composition can be applied on a transparent plastic film and then laminated to form an antifogging layer.

Also, if the adhesiveness between the hydrophilic film and the heat insulating film or sheet is not sufficient, perform an easy adhesion treatment on the hydrophilic film,
By laminating, the hydrophilic film can be transferred.

In consideration of the workability of the heat insulating sheet having dew condensation prevention (anti-fog) performance in the present invention, it is convenient to appropriately form an adhesive layer on the side opposite to the dew condensation prevention layer.

〔Example〕

Next, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these.

Example 1 (a) As a heat insulating sheet, a window glass heat insulating sheet manufactured by Nitoms Co., Ltd., in which a striped core material was provided between two transparent polyethylene films and an air layer was formed therebetween, was used.
(B) Transparent heat ray reflective film LEFTEL (trade name) (polyester base, 25 μm thickness) manufactured by Teijin Limited is applied as a heat insulating film, and the following composition is applied to one surface of each with a roll coater and dried with a dryer. Thus, a hydrophilic film having a thickness of 5 μm was formed.

Acrylic polymer solution 300 parts by weight 2-hydroxyethyl methacrylate (hydrophilic monomer) 70 parts by weight Pentaerythritol triacrylate (hydrophilic crosslinkable monomer) 10 parts by weight Methyl ethyl ketone (solvent) 300 parts by weight The acrylic polymer solution was prepared as follows. Performed by the procedure. That is, methyl methacrylate 700 parts by weight,
And 2-hydroxyethyl methacrylate 390 parts by weight, and 1.5 part by weight of azobisisobutyronitrile and methyl ethyl ketone 2210 parts by weight, comprising a reflux condenser and a stirrer, were placed in a separable flask purged with nitrogen, in an N ₂ stream The reaction was performed at 85 ° C. for 5 hours. Thereafter, 1.5 parts by weight of azobisisobutyronitrile was further added and reacted for 3 hours. The resulting acrylic polymer solution had a concentration of 33% by weight and had a weight average molecular weight (w) of 7.5 × 10 ^{4 as} measured by gel permeation chromatography (GPC). No monomer peak was observed.

Next, an electron beam of 175 keV was irradiated at 5 Mrad by an electron curtain type EB device (manufactured by ESI) to cure the coating film.

The anti-condensation properties (anti-fogging properties) of the two types of obtained anti-fogging heat insulating sheets were evaluated by the following method.

(1) Expiration test (check whether or not fogging occurs due to expiration). ：: no fogging occurred, x: fogging occurred.

(2) Temperature difference test An indoor / outdoor temperature difference deterioration tester (BP-FM-1 manufactured by Suga Test Instruments Co., Ltd.) consisting of two rooms separated by a glass plate and capable of freely controlling the temperature and humidity of each room. Was. After attaching the evaluation sample with the adhesive treatment applied to the back side, the temperature and humidity fluctuation cycle of the other room (60% relative humidity, temperature -10 ° C
For 30 minutes, followed by 2 hours at 20 ° C.). The evaluation was performed by observing the clouding state (transparency, clear visibility) for each cycle.

○ It is not cloudy at all.

△ No fogging, but no visibility.

× Fine water droplets adhere to the entire surface and are opaque.

The antifogging heat-insulating sheets of the present invention were both good in (1) breath test and (2) temperature difference test in both cases.

Examples 2 to 10 Using each of the compositions shown in Table 1, a hydrophilic film was formed on a heat insulating sheet in the same manner as in Example 1, and the same evaluation was performed. The results are shown in Table 1.

The urethane acrylate of Example 4 was prepared according to the following procedure. That is, the same apparatus as in Example 1 was used, and butylene adipate ("Nipporan N-45") was used therein.
70 "(manufactured by Nippon Polyurethane Co., Ltd.), 650 g, methyl ethyl ketone 300 g, and isophorone diisocyanate 444 g were added, and a solution prepared by dissolving 1 g of dibutyltin dilaurate in 10 g of methyl ethyl ketone was added dropwise with stirring at 60 ° C. 5
For 2 hours, 232 g of 2-hydroxyethyl acrylate was added dropwise while stirring in a nitrogen stream, and after the addition was completed, stirring was continued at 70 ° C. for 3 hours. -NCO by infrared absorption spectrum
When the disappearance of the group peak was confirmed, the reaction was terminated.
The weight average molecular weight (w) of the obtained polymer was 1700 by GPC.

Comparative Example The same evaluation test as in Example 1 was performed on a window glass heat insulating sheet (manufactured by Nitoms Corporation) and a transparent heat ray reflective film Leftel (manufactured by Teijin Limited) in which a hydrophilic film was not provided on the surface layer. The results are as shown in Table 1. Both the sheet and the film were evaluated as x in the breath test and the temperature difference test.

(Note) (1) 7: 3 (molar ratio) copolymer of methyl methacrylate and 2-hydroxyethyl methacrylate (2) Polymethyl methacrylate (3) 7: 3 of methyl methacrylate and N, N-dimethylacrylamide (Molar ratio) copolymer (4) 2-hydroxyethyl methacrylate (5) glycerol monomethacrylate (6) N-acryloylmorpholine (7) N, N-dimethylacrylamide (8) diethylene glycol dimethacrylate (9) dipenta Erythritol hexaacrylate (10) Tetraethylene glycol diacrylate (11) Pentaerythritol acrylate (12) Dipentaerythritol pentaacrylate (13) Ethylene glycol diglycidyl ether diacrylate (14) Methyl ethyl ether (15) Window Lath heat insulating sheet (manufactured by Nitoms Co., Ltd.) (16) Transparent heat ray reflective film (manufactured by Teijin Limited) Examples 11 to 15 The hydrophilicity of Examples 1 and Examples 3, 4, 6, and 9 shown in Table 1. After newly adding the surfactants shown in Table 2 to the composition of the hydrophilic film, a hydrophilic film containing the surfactant was obtained in the same manner as in Example 1.

These hydrophilic films were evaluated in the same manner as in Examples 1 to 10. The results are shown in Table 2.

[Effect of the Invention] The antifogging heat insulating sheet of the present invention has excellent antifogging properties because the polymer skeleton has a hydrophilic film in which a hydrophilic monomer and / or a hydrophilic crosslinkable monomer is crosslinked. It has sufficient hardness and strength and functions sufficiently as a surface layer of a heat insulating sheet.

Moreover, the water absorption performance of the hydrophilic film provided on the surface layer and / or
Alternatively, due to the combination of the surface activity and the heat insulating performance of the heat insulating film or sheet, even if the temperature difference between the inside and outside becomes large, fine water droplets (cloudiness) do not occur on the indoor side surface, and sufficient transparency and lightness are obtained. Visibility can be obtained.

[Brief description of the drawings]

1 to 4 are cross-sectional views showing examples of the anti-fogging heat insulating sheet of the present invention having a low thermal conductivity layer, and FIG. 5 is an anti-fogging heat insulating sheet of the present invention having a heat ray reflecting / blocking layer. It is sectional drawing which shows the example of a sheet. 1, 2, 11, 12, 31, 32 ... Film 4, 14, 24, 34 ... Air layer 5, 15, 25, 35, 42 ... Hydrophilic film 41 ... Heat ray reflective film

Claims (7)

(57) [Claims] 1. A transparent heat-insulating film or sheet comprising a core material for forming an air layer between two flat transparent films, wherein a hydrophilic film cross-linked by electron beam irradiation is formed on the surface of the sheet. Characteristic anti-fog insulation sheet. 2. A transparent heat-insulating film or sheet in which a flat transparent film is bonded to a convex portion of a transparent film having irregularities on one side, and a hydrophilic film cross-linked by electron beam irradiation is formed on the surface of the sheet. Characteristic anti-fog insulation sheet. 3. An anti-fogging heat-insulating sheet, characterized in that a hydrophilic film cross-linked by electron beam irradiation is formed on the surface of the heat ray reflective film or sheet. 4. The anti-fogging heat-insulating sheet according to claim 1, wherein the hydrophilic film comprises a polymer and a hydrophilic monomer, and is cross-linked by electron beam irradiation. Anti-fog insulation sheet. 5. The antifogging heat-insulating sheet according to claim 1, wherein the hydrophilic film comprises a polymer, a hydrophilic monomer and a crosslinkable monomer, and is crosslinked by electron beam irradiation. An anti-fogging heat insulating sheet, characterized in that: 6. The antifogging heat-insulating sheet according to claim 1, wherein the hydrophilic film comprises a polymer and a hydrophilic crosslinkable monomer, and is crosslinked by electron beam irradiation. Characteristic anti-fog insulation sheet. 7. The anti-fogging heat insulating sheet according to claim 1, wherein the hydrophilic film comprises the polymer 10
An antifogging heat insulating sheet containing 100 parts by weight or less of a surfactant per 0 parts by weight.