JP2000334876A - Laminate having heat ray reflecting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film excellent in heat ray reflecting function and scratch resistance when used as a film for an indoor window and capable of keeping this effect over a long period of time. SOLUTION: In a laminate wherein a heat ray reflecting layer (B), a photocatalytic function layer (C) and a surface protective layer (D) are laminated on the single surface of a transparent thermoplastic resin film in this order and a self-adhesive layer (E) and a release film (F) are laminated on the other surface thereof in this order, a ratio (Pa/Pb) of the peel strength (Pa [g/cm]) of the surface protective film (D) to the photocatalytic function layer (C) and the peel strength (Pb [g/cm]) of the self-adhesive layer (E) to glass is 0.9 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate having a heat ray reflecting function, and more particularly, to a laminate having an excellent abrasion resistance and exhibiting a heat ray reflecting function when bonded to an indoor window for a long time. The present invention relates to a laminate having a heat ray reflecting function that can be sustained.

[0002]

2. Description of the Related Art A heat ray reflective film is generally a laminate in which a transparent polyester film is used as a base material, and a metal thin film layer is sandwiched between transparent dielectric layers having a high refractive index as a heat ray reflective layer.
Although it transmits visible light, it has the property of reflecting light from the near-infrared portion to the infrared portion well. Taking advantage of this characteristic, the heat ray reflective film reduces the heat radiation from the monitoring window in high-temperature work, improves the cooling and heating effect by blocking the solar energy that enters from the windows of vehicles such as buildings, cars or trains, and improves the transparency. It is used for improving the heat reflectivity of a food container, or for improving the cooling effect in a freezing and refrigerated showcase.

[0003] In particular, when the heat ray reflective layer is used by attaching it to an indoor window, the heat ray reflective layer is prevented from being damaged when the window is cleaned, so that the heat ray reflective layer can be protected and the number of times of cleaning can be reduced. A photocatalytic functional layer having a layer is laminated on a heat ray reflective layer.

However, when laminating such a laminated film on a window, the laminated film is adhered to the window via a surfactant-containing water, and the film surface is rubbed with a tool such as a squeegee to remove water and air bubbles. There is a problem that the photocatalytic functional layer, which is the outermost surface, is scratched due to adhesion.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat ray reflecting function which is excellent in abrasion resistance and exhibits a heat ray reflecting function when laminated to an indoor window, and which function can be maintained for a long time. The object of the present invention is to provide a laminate having:

[0006]

According to the present invention, a heat ray reflective layer (B), a photocatalytic functional layer (C) and a surface protective film (D) are laminated in this order on one side of a transparent thermoplastic resin film (A). And a laminate in which an adhesive layer (E) and a release film (F) are laminated in this order on the surface of the transparent thermoplastic resin film (A), and a surface protective film for the photocatalytic functional layer (C) ( D) Peel strength (Pa [g / c
m]) and the peel strength (P) of the adhesive layer (E) against glass.
b (g / cm)), which is a laminate having a heat ray reflection function, wherein the ratio (Pa / Pb) is 0.9 or less.

[Transparent thermoplastic resin film (A)] The transparent thermoplastic resin film (A) of the laminate of the present invention is transparent and flexible, and is formed by a sputtering method or a vacuum deposition method. It is a film having heat resistance that can form a vapor deposition layer. Examples of the polymer constituting such a thermoplastic resin film include polyester represented by polyethylene terephthalate and polyethylene naphthalate, aliphatic polyamide, aromatic polyamide, polyethylene, and polypropylene. Of these, polyester is preferred. Further, a biaxially oriented polyester film excellent in heat resistance and mechanical strength, particularly a biaxially oriented polyethylene terephthalate film is preferable.

[0008] Such a thermoplastic resin film can be produced by a conventionally known method. For example, a biaxially oriented polyester film is obtained by drying a polyester, melting it at a temperature of Tm to (Tm + 70) ° C. (where Tm is the melting point of the polyester) with an extruder, and forming a die (for example, T
-Die, I-die, etc.) onto a rotating cooling drum,
It is quenched at 40 to 90 ° C. to produce an unstretched film, and then the unstretched film is (Tg-10) to (Tg + 70)
At a temperature of 2.5 ° C. (Tg: glass transition temperature of polyester) at a magnification of 2.5 to 8.0 times,
Stretch at a magnification of ~ 8.0 times, and if necessary, 180 ~ 25
It can be manufactured by heat setting at a temperature of 0 ° C. for 1 to 60 seconds. The thickness of the thermoplastic resin film is preferably in the range of 5 to 250 μm.

[Heat ray reflection layer (B)] In the present invention, the heat ray reflection layer (B) provided on one side of the transparent thermoplastic resin film (A) is a layer having a heat ray reflection property or a heat ray shielding property, and a metal layer. And dielectric layers are alternately laminated.

The metal material constituting the metal layer in the present invention includes metals such as Au, Ag, Cu, and Al and alloys thereof, SnO ₂ doped with Sb, and In ₂ O ₃ (ITO) doped with Sn. Semiconductor thin films having a wide optical band gap and a high free electron density are exemplified.
Among these, one or more metals selected from Au, Ag, and Cu or alloys thereof are preferable, and Ag, which hardly absorbs visible light, is particularly preferable. In addition, you may use 2 or more types of metal substances together as needed. As a method for forming such a metal layer, a vapor phase growth method is preferable, and a vacuum deposition method, a sputtering method or a plasma CVD method is particularly preferable. The thickness of the metal layer is 40 wavelengths of the laminate of the present invention.
The integrated visible light transmittance at 0 to 750 nm is preferably set to satisfy 55% or more, and the integrated near-infrared light transmittance at 750 to 2100 nm is preferably set to 50% or less, and more preferably 5 to 1000 nm. When the thickness is less than 5 nm, a sufficient heat ray reflection effect is not exhibited, and the infrared transmittance increases. On the other hand, when the thickness exceeds 1000 nm, the visible light transmittance decreases and the transparency deteriorates.

The dielectric layer in the present invention needs to be transparent and have a high refractive index in order to suppress reflection of visible light and enhance transparency. Such dielectrics include Ti
O ₂ , ZrO ₂ , SnO ₂ , In ₂ O _{3 and the} like can be mentioned. TiO ₂ or Zr derived from an organic compound obtained by hydrolysis of alkyl titanate or alkyl zirconium
O ₂ is preferred because of its excellent workability. In addition, indium oxide or tin oxide can be applied as a dielectric layer in a single layer or a multilayer. As a method for forming such a dielectric layer, a vapor phase growth method is preferable, and a vacuum deposition method, a sputtering method, or a plasma CVD method is particularly preferable. In addition, the dielectric layer has a laminated structure in which the above-described metal layer is sandwiched between the layers, whereby the effect of improving transparency is increased. The thickness of the dielectric layer is preferably 750 nm or less.

In the present invention, the thickness of the above-mentioned metal layer and dielectric layer is 400 to 400 nm of the laminated film of the present invention.
It is preferable to set so that the integrated visible light transmittance at 750 nm satisfies the range of 55% or more and the integrated near-infrared light transmittance at the wavelength of 750 to 2100 nm satisfies the range of 50% or less.

[Photocatalyst Functional Layer (C)] In the present invention, a photocatalyst comprising a composition comprising a hydrolysis condensate of a titanium oxide and a hydrolyzable silicon compound is provided on the above-mentioned heat ray reflective layer (B). The functional layer (C) is provided.

The titanium oxide constituting the photocatalytic function layer is one which exhibits a catalytic action on the oxidation-reduction of organic substances by irradiation with light having a specific energy, and includes pure titanium oxide, hydrous titanium oxide, Includes what are called hydrated titanium oxide, metatitanic acid, orthotitanic acid, and titanium hydroxide. Titanium dioxide or those in a lower oxidation state than this are particularly preferably used. The crystal form of titanium dioxide may be any of anatase type, rutile type and flukite type, and may be a mixture thereof, but anatase type is particularly preferable. These titanium oxides are in the form of fine powder, and the particle size is 0.001 to 0.001 in view of the photocatalytic activity.
Those having a thickness of 0.5 μm are preferred. This fine powder may be used as a powder in a dry state, but is desirably prepared in advance as a dispersion so as to be uniformly dispersed with a hydrolyzed condensate of a hydrolyzable silicon compound described later. Whether or not the titanium oxide is well dispersed in the composition of the present invention greatly affects the photocatalytic function when a coating film is formed. Titanium oxide is produced by various known methods. For example, A. A method of hydrolyzing a titanium compound such as titanyl sulfate, titanium chloride, and an organic titanium compound in the presence of a nucleating species, if necessary; Titanyl sulfate, titanium chloride,
A method of adding an alkali to a titanium compound such as an organic titanium compound, if necessary, in the presence of a core forming seed, and neutralizing the same;
C. A method of vapor-phase oxidation of titanium chloride, an organic titanium compound, or the like; A method of firing the titanium oxide obtained by the methods A and B described above, and the like. In particular, titanium oxides obtained by the methods A and B are preferable because of their high photocatalytic function. To further improve the photocatalytic function, the surface of the titanium oxide may be coated with a metal such as platinum, gold, silver, copper, palladium, rhodium, ruthenium, or a metal oxide such as ruthenium oxide or nickel oxide. These titanium oxides are used after being highly dispersed in a solvent such as water. In order to uniformly disperse the ultrafine titanium oxide in a solvent such as water without secondary aggregation, it is preferable to store the titanium oxide as acidic or alkaline. When placed under acidic conditions, the pH is preferably adjusted to 0.5 to 4, particularly preferably 1 to 3.5. As a dispersion medium, a mixture of water and an alcohol may be used in addition to water.

Examples of the hydrolyzable silicon compound used in the present invention include alkyl silicates and silicon halides, and also include partially hydrolyzed products thereof. As the alkyl silicate, methyl silicate, ethyl silicate, isopropyl silicate and the like are used. Among these, a compound represented by the following formula (1) is preferable.

[0016]

Embedded image

(In the formula (1), n is an integer of 0 to 8, X ¹ ,
X ² , X ³ and X ⁴ each represent a halogen atom or an alkoxy group having 1 to 8 carbon atoms. Where X ¹ , X ² , X
³ and X ⁴ may be the same or different from each other. )

[0018] Such hydrolyzable silicon compounds, either used in the form of oligomers produced by monomeric or partially hydrolyzed, as the oligomeric formula Si _n
On _-1 (OR) _{2n + 2} (where n is 2 to 6, R is 1 carbon atom)
To 4 alkyl groups) are particularly preferred. These oligomers can also be used in a mixture. Such a hydrolyzable silicon compound forms a composition with the titanium oxide in a hydrolyzed form. As a catalyst for the hydrolysis, either an acid or an alkali can be used. When the titanium oxide dispersion is acidic, an alkyl silicate hydrolyzed with an acid is preferred. Water or an alcohol having 1 to 4 carbon atoms is used as a dispersion solvent for the hydrolysis solution. Esters such as ethyl acetate are not preferred because they make the composition liquid unstable. The hydrolyzable silicon compound and its partial hydrolyzate used in the present invention are used for the purpose of binding titanium oxide, and are hereinafter referred to as silica binder.

The mixing of the titanium oxide and the silica binder can be carried out appropriately. In one example, a predetermined amount of an aqueous dispersion of titanium dioxide under an acidic condition is maintained at a liquid temperature of 10 to 50 ° C. and weighed. The silica binder thus obtained is added dropwise over a period of time. After completion of the dropwise addition, the mixture is reacted under stirring for 1 to 5 hours to prepare a composition liquid. The hydrolysis catalyst may be added at the same time as the addition of the silica binder, or the hydrolysis may be promoted by utilizing the acid component present in the titanium dioxide dispersion. When an alcohol-based medium is used as a dispersion medium, a water / alcohol mixed medium dispersion of titanium dioxide and a silica binder in an alcohol medium having a silica binder content of 50 to 15 are used.
The composition can also be obtained by mixing the solution hydrolyzed with 00% with stirring. In the present invention, the hydrolysis rate is calculated based on the amount of water used assuming that the hydrolysis rate is 100% when 1 mole of silica binder is used and 2 mole of water is used. When a partial hydrolyzate in the form of the general formula Si _n O _n-1 (OR) _{2n + 2} is used, the hydrolysis rate is 1 when the mole of condensate is used and n + 1 mole of water is used.
Calculate as 00%.

In the composition of the present invention, the ratio between the titanium oxide and the silica binder is determined by the weight ratio (SiO ₂ / (TiO ₂ + Si) in terms of titanium dioxide and silicon dioxide, respectively.
O ₂ ) × 100) is preferably 4 to 70% by weight. When the proportion of silica exceeds 70% by weight, the photocatalytic function of the titanium oxide becomes small, and the practicality becomes poor. This is presumably because the proportion of silica covering the surface of the titanium oxide particles is increased, which hinders contact between the titanium oxide and the substance to be oxidatively decomposed. On the other hand, when the mixing ratio of the silica binder is 4% by weight or less, the adhesive strength between the base material and the titanium oxide is not sufficient, and easily falls off by touch or vibration, which makes it difficult to industrially use as a coating film. Become something. A more desirable ratio of the silica binder is 10 to 50% by weight. A small amount of titanium alkoxide and titanium tetrachloride may be added to the composition of the present invention. Further, titanium or a silane coupling agent may be added. Further, various surfactants may be added to ensure the stability of the composition and improve the wetting characteristics. Also, a small amount of an alkoxysilane or a hydrosilane containing two or more alkoxy groups may be added, but these titanium and silane compounds are to be added in terms of silica when calculating the solid content.

As a method of forming the photocatalytic functional layer (C) from such a composition, a method of applying a coating liquid containing the composition is preferred. Furthermore, a coating liquid containing the composition is applied, dried,
In some cases, a method of baking at a low temperature to form a coating film is preferable. As an application method, spin coating, spray coating, bar coating, dipping, or the like is appropriately used depending on the shape of the substrate to be applied. The thickness of the coating is 0.1 ~
3 μm, particularly preferably 0.3 to 2 μm. The photocatalytic activity of titanium oxide is related to the amount of titanium oxide that can be exposed to the surface and contacted with the compound to be oxidatively decomposed. In addition, the dispersion of particles does not always achieve the ideal uniformity.If the thickness is too small, the amount of titanium oxide on the surface of the coating film is small and the photocatalytic activity is not sufficient. preferable. When the thickness is within the above range, the coating film becomes transparent, and a photoactive coating film can be formed on the surface without impairing the transparency and color of the substrate. The silica binder is hydrolyzed and condensed by applying the coating liquid, drying, and optionally firing at a low temperature to form a coating film.

In general, when a titanium oxide having a photocatalytic function is laminated on a substrate or a film made of an organic substance, the organic substance is decomposed by light energy, the adhesion of the titanium oxide is reduced, and the titanium oxide eventually falls off. . Conventionally, in order to prevent this, it has been necessary to provide one or more inorganic layers inactive to the photocatalytic reaction on the surface of the organic substance. On the other hand, in the configuration of the laminate of the present invention, since the photocatalytic function layer (C) is provided on the heat ray reflective layer (B), there is an effect that the inorganic layer is not required and direct lamination is possible. .

By providing the photocatalytic functional layer (C),
In the laminate of the present invention, the heat ray reflection characteristics are maintained for a long period of time, and the self-cleaning effect due to the photocatalytic activity can eliminate the cleaning work, thereby avoiding abrasion during cleaning.

[Surface protective film (D)] Lamination of the present invention
The body is further provided with a surface protective film on the photocatalytic functional layer (C).
Lam (D) is laminated. Surface protective film (D) is light
A base film to be laminated on the catalyst functional layer (C)
(D₁) Has an adhesive layer (D_Two), The adhesive layer
(D _Two) Through the photocatalytic functional layer (C)
Is preferred. Adhesive layer (D_Two) Of the photocatalytic functional layer (C)
The peel strength is preferably 180 g / cm or less.
No. When the peel strength exceeds 180 g / cm,
The titanium oxide of the photocatalytic function layer (C) is partially dropped.
It is not preferable because it may occur. Adhesive layer (D_TwoMake up)
Adhesive that satisfies the above range of peel strength
It is not particularly limited, for example, synthetic rubber-based, acrylic-based
An adhesive is exemplified. Adhesive layer (D_TwoPressure-sensitive adhesive
Is a pressure-sensitive adhesive constituting a pressure-sensitive adhesive layer (E) described later and a composition system thereof.
May be the same or different. Also, sticky
Coating layer (D_TwoAcrylic adhesive polymer for the adhesive that constitutes)
-, Acrylic monomers and oligomers, and light weight
By using the composition consisting of the initiator, the ultraviolet light
The adhesive layer (D_Two) The peel strength of the surface is lost
It is preferable to take the method of peeling the protective film (D)
No. Base film (D₁) Is flexible
To the extent that the photocatalyst functional layer (C) is not scratched during installation
The film is not particularly limited as long as it has a strength of. example
For example, a polyethylene terephthalate film
Steal film, polyamide film, polyolefin
Films and the like.

[Adhesive Layer (E)] In the laminate of the present invention, an adhesive layer (E) is provided on the surface of the transparent thermoplastic resin film (A) opposite to the surface on which the heat ray reflective layer (B) is provided. The laminate of the present invention is bonded to a window glass via the adhesive layer (E). The peel strength of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (E) from glass is preferably in the range of 200 g / cm or more. If the peel strength is less than 200 g / cm, the laminate may peel off from the window glass. Also, the peel strength (P) of the surface protective film (D) with respect to the photocatalytic functional layer (C)
a) and the peel strength (P) of the adhesive layer (E) to glass
b) ratio (Pa / Pb) is 0.9 or less, preferably 0.1%.
It needs to be in the range of 005 to 0.9. When the ratio exceeds 0.9, the whole laminate is peeled off when the protective film (D) is peeled off after laminating the laminate to the window glass, which is not preferable.

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (E),
Those having durability to ultraviolet rays are preferred, and acrylic adhesives or silicone adhesives are preferred. Further, from the viewpoint of adhesive properties and cost, an acrylic adhesive is preferable. Particularly, among the solvent-based and emulsion-based acrylic pressure-sensitive adhesives, the solvent-based pressure-sensitive adhesive is preferably a solvent-based one because of easy control of peel strength. When a solution-polymerized polymer is used as the acrylic solvent-based pressure-sensitive adhesive, a known monomer can be used as the monomer. For example, as a main monomer as a skeleton, ethyl acrylate, butyl acrylate, 2-acrylate
Ethyl hexyl acrylate, acrylates such as acrylyl acrylate, and the like, and comonomers for improving cohesion include vinyl acetate, acrylonitrile, styrene, methyl methacrylate, and the like.
Further, the functional group-containing monomer for promoting cross-linking and imparting a stable adhesive force and maintaining a certain adhesive force even in the presence of water includes methacrylic acid, acrylic acid,
Examples include itaconic acid, hydroxyethyl methacrylate, and glycidyl methacrylate. The polymerization of the adhesive is
It can be performed by a known method. For example, in the presence of an organic solvent such as ethyl acetate or toluene, a predetermined starting material is charged into a reaction vessel, and a catalyst based on a peroxide system such as benzoyl peroxide or an azobis system such as azobisisobutyronitrile is used. It can be polymerized under heating. In order to increase the molecular weight, for example, it is preferable to use a method in which monomers are charged all at once in the initial stage, and to use an organic solvent species that uses ethyl acetate rather than toluene, which has a large chain transfer coefficient and suppresses polymer growth. The weight average molecular weight (Mw) of the polymer is 4
It is preferably at least 100,000, more preferably at least 500,000. If the molecular weight is less than 400,000, even if cross-linked with an isocyanate curing agent, sufficient cohesive strength cannot be obtained. When peeled off after a lapse of time, the adhesive may remain on the glass plate.

As a curing agent for the pressure-sensitive adhesive, a general isocyanate-based curing agent or an epoxy-based curing agent can be used particularly in the case of an acrylic solvent system. Is required, an isocyanate-based curing agent is preferred.

In the present invention, the peel strength (Pa [g / cm]) of the surface protective film (D) to the photocatalytic functional layer (C)
Strength of the pressure-sensitive adhesive layer (E) against glass and glass (Pb [g
/ cm]) (Pa / Pb) of 0.9 or less can be achieved by adjusting the peel strength of the adhesive of the adhesive layer (E) or the adhesive layer (D ₂ ) of the surface protective film. it can. The peel strength of the pressure-sensitive adhesive, for example, in the case of an acrylic pressure-sensitive adhesive, can be adjusted by the glass transition temperature, molecular weight, or the amount of a hardener added to the acrylic pressure-sensitive polymer. It is preferable because it is simple and convenient. Specifically, the peel strength decreases as the amount of the curing agent added increases.

The pressure-sensitive adhesive may contain additives such as a stabilizer, an ultraviolet absorber, a flame retardant, and an antistatic agent. The thickness of the adhesive layer (E) is preferably from 5 to 50 μm. The pressure-sensitive adhesive layer (E) is provided by applying the pressure-sensitive adhesive to one surface of the transparent thermoplastic resin film (A). As the coating method, any known method can be used, and a die coater method, a gravure coater method, a blade coater method,
Spray coater method, air knife coat method, dip coat method and the like can be mentioned. Further, before lamination of the adhesive layer (E), the surface of the transparent thermoplastic resin film (A) may be subjected to physical treatment such as flame treatment, corona discharge treatment, plasma discharge treatment, etc. for the purpose of improving adhesion and coating properties, if necessary. It is preferable to carry out a chemical surface treatment such as a surface treatment or the application of an easily adhesive organic or inorganic resin.

[Release Film (F)] A release film is laminated on the surface of the adhesive layer (E) of the laminate of the present invention to protect the adhesive layer. The release film (F) is not particularly limited as long as it can be easily peeled immediately before laminating the laminate to glass, and may be a known film.

The release film preferably has a structure in which a release layer is provided on an organic polymer film. As such an organic polymer film, a polyester film is preferable, and a biaxially stretched polyester film having excellent mechanical strength and thermal dimensional stability is more preferable. The polyester constituting such a polyester film is preferably a crystalline linear saturated polyester comprising an aromatic dibasic acid component and a diol component. For example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2, 6-naphthalate and the like are exemplified. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalate are more preferred. The release layer may be any layer made of a known agent having a releasability, but is preferably a layer made of a curable silicone resin. As the curable silicone resin, those generally known as a release agent can be used. For example, selected from known ones described in "Silicone Material Handbook" (edited by Toray Dow Corning, 1993. 8) and the like can be used. can do. For example, KS-847 (H), KS-77 manufactured by Shin-Etsu Silicone Co., Ltd.
6, TPR-6700 manufactured by Toshiba Silicone Co., Ltd., and the like. As these curing methods, heat or radiation curing types are generally used. The form of the curable silicone resin can be appropriately selected from solvent type, emulsion type, and solventless type. The release layer can be provided by applying a coating liquid containing the silicone resin to a base film, drying and curing the coating liquid. As a method of applying the coating liquid, for example, a spin coating method, a spray coating method, a bar coating method, a gravure coating method, a reverse coating method, and a comma coating method can be used. The coating is preferably performed so that the film thickness after drying is 0.05 to 1.0 μm.

[0032]

The present invention will be described in more detail with reference to the following examples. The characteristics of the film were measured and evaluated by the following methods.

(1) Preparation of a measurement sample Water containing a surfactant was sprayed on one surface of a glass plate having a thickness of 3 mm, and the pressure-sensitive adhesive layer of the laminate prepared in Examples and Comparative Examples was bonded to the surface. Then, water and bubbles between the glass plate and the laminate are removed by squeezing the surface with a rubber squeegee. Thereafter, the temperature is maintained for 12 hours, and the protective film of the laminate is peeled off to prepare a measurement sample.

(2) Infrared reflectance Using a spectrophotometer (FT-IR / 700, JASCO Corporation), the amount of infrared reflection of the measurement sample in the wavelength range of 5 to 25 μm is measured. The reflectance is determined by assuming that the reflection of silver is 100%.

(3) Scratch resistance The following criteria are used to evaluate the state of lamination during the preparation of the measurement sample and the visual observation of scratches on the surface of the measurement sample after peeling off the protective film. ○: Good lamination condition, no scratches △: Fine scratches ×: Poor bonding or scratches

(4) Peeling Strength (Pa, Pb) In preparing the measurement sample, the peeling strength (Pa, unit: g / cm) when the protective film was peeled at 180 °, and the laminated film was prepared from the measurement sample. The peel strength (Pb, unit: g / cm) at 180 ° peel was measured.

Example 1 Polyethylene terephthalate (containing 500 ppm of lubricant) having an intrinsic viscosity of 0.65 measured in o-chlorophenol at 35 ° C. was synthesized, and the polyethylene terephthalate was placed on a rotating cooling drum maintained at 20 ° C. It was melt-extruded to obtain an unstretched film having a thickness of 1580 μm, then stretched 3.5 times in the machine axis direction, and subsequently stretched 3.9 times in the transverse direction while heating at 105 ° C.
Further, heat treatment was performed at 210 ° C. to obtain a polyester film having a thickness of 50 μm. 15 nm thick on one side of this film
Of a titanium oxide layer (dielectric layer; first layer), a silver layer (metal layer; second layer) having a thickness of 12 nm is provided thereon, and a titanium oxide layer (dielectric layer) having a thickness of 25 nm is further provided thereon. Layer; third
Layer) to form a heat ray reflective layer. In addition,
All three layers were formed by a sputtering method under vacuum (5 × 10 ⁻⁵ torr). Next, an average particle size of 0.07
As a composition of anatase-type titanium dioxide particles of about 0.1 μm and ethyl silicate, a composition having a ratio of 50 parts / 50 parts in terms of TiO ₂ / SiO ₂ was dissolved in a solvent, and a solution having a solid concentration of 10% was prepared. The coating solution (ST-K03: manufactured by Colcoat Co., Ltd.) was coated at a coating amount of 5 g / m ² and dried at 150 ° C. for 2 minutes to form a photocatalytic functional layer. On the other surface of the polyester film, an acrylic pressure-sensitive adhesive having a peel strength to glass of 500 g / cm was applied so as to have a dry film thickness of 20 μm to obtain a laminated film. Further, as a protective film, a polyethylene terephthalate film having a thickness of 25 μm has a peel strength of 50 g / cm on one side.
A film was prepared by laminating the above acrylic pressure-sensitive adhesive to a dry film thickness of 15 μm, and this was laminated on the photocatalytic functional layer of the above-mentioned laminated film to produce a laminate. Table 1 shows the properties of the laminated film.

Example 2 A laminate was prepared in the same manner as in Example 1, except that an ultraviolet-curable pressure-sensitive adhesive having a peel strength of 10 g / cm after UV irradiation was used as the pressure-sensitive adhesive for the protective film. . Table 1 shows the properties of the laminated film. The measurement sample was irradiated with ultraviolet rays before the protective film was peeled off.

Comparative Example 1 A laminate was prepared in the same manner as in Example 1 except that the protective film was not laminated. Table 1 shows the properties of the laminated film.

Comparative Example 2 The pressure-sensitive adhesive for forming a pressure-sensitive adhesive layer (peeling strength to glass: 5)
(00 g / cm), and a laminate was prepared in the same manner as in Example 1. Table 1 shows the properties of the laminated film.

[0041]

[Table 1] ---------------------------------------------- -------------- Pa / Pb Infrared reflectance (%) Scratch resistance ------------------------ ------------------------------------ Example 1 0.1 90 ○ (good) Example 2 0.1 90 ○ (good) Comparative Example 1-10 △ (fine scratches) Comparative Example 2 1.075 × (poor sticking, surface layer peeling) ---------------- --------------------------------------------

[0042]

According to the present invention, it is possible to provide a heat ray reflective film used for indoor windows, which is excellent in heat ray reflection function and scratch resistance and can maintain such an effect for a long period of time. .

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2E039 AB00 4F100 AA21C AK01A AK52C AR00B AR00C AR00D BA05 BA07 BA10A BA10E BA13 CB05E GB08 JA20C JB16A JD12B JK06 JK06D JK06E JL00D JL13E JN01YAB04 YA00A04B CA11 DA06 EA08 ED03 ED04 EE01 EE06 FB23

Claims (4)

[Claims] 1. A heat-reflective layer (B), a photocatalytic function layer (C) and a surface protective film (D) are laminated in this order on one side of a transparent thermoplastic resin film (A), and the opposite transparent thermoplastic resin A laminate in which an adhesive layer (E) and a release film (F) are laminated in this order on the resin film (A) surface, and the peel strength (Pa) of the surface protective film (D) with respect to the photocatalytic functional layer (C). [g / cm]) and the peel strength (Pb [g / cm]) of the adhesive layer (E) to glass (Pa / P
(b) is 0.9 or less, a laminate having a heat ray reflection function. 2. The photocatalytic functional layer (C) comprises a composition comprising a titanium oxide and a hydrolyzable condensate of a hydrolyzable silicon compound, wherein the titanium oxide has an average particle size of 0.001 to 0.001. The laminate having a heat ray reflection function according to claim 1, which is 0.5 µm, and wherein the hydrolyzable silicon compound is a compound represented by the following formula (1). Embedded image (In the formula (1), n is an integer of 0 to 8, X ¹ , X ² , X ³ , X ⁴
Represents a halogen atom or an alkoxy group having 1 to 8 carbon atoms, respectively. However, X ¹ , X ² , X ³ and X ⁴ may be the same or different from each other. ) 3. The surface protective film (D) is a film in which an adhesive layer (D ₂ ) having a peel strength of 180 g / cm or less with respect to the photocatalytic functional layer (C) is provided on one surface of the base film (D ₁ ). There, the adhesive layer (D ₂₎ through the surface protective film (D) and photocatalytic functional layer (C) is a laminate having a heat ray reflecting function of claim 1, wherein are laminated. 4. The laminate having a heat ray reflection function according to claim 1, wherein a peel strength of the pressure-sensitive adhesive layer (E) to glass is 200 g / cm or more.