JP2000037808A - Laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated film excellent in the adhesion of a photocatalyst functional layer comprising titanium oxide and a polyester film becoming a base material and developing photocatalytic function (e.g.; surface antifouling effect, antibacterial effect, hydrophilifying effect). SOLUTION: A laminated film is constituted by applying a compsn. based on an aq. soln. or dispersion of at least one resin selected from a polyester resin, an acrylic resin and an acrylic resin and a vinyl type resin modified polyester resin to at least the single surface of a polyester film before the completion of orientation crystallization and applying drying, stretching and thermal fixation to the coated film to provide a primer layer and providing a photocatalyst functional layer comprising a compsn. constituted of titanium oxide with an average particle size of 0.001-0.5 μm and a hydrolyzate of a hydrolyzable silicon compd. represented by formula (wherein (n) is an integer of 0-8 and X1, X2, X3 and X4 are respectively a halogen atom or a 1-8C alkoxy group and may be mutually same or different) on the primer layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film provided with a titanium oxide-containing layer used as a photo-oxidation catalyst, and more particularly to a laminated film having excellent adhesion between the titanium oxide-containing layer and a polyester film. About.

[0002]

2. Description of the Related Art Titanium oxide is itself an optical semiconductor, and has light having an energy greater than its band gap.
For example, when irradiated with ultraviolet rays, electrons are excited in the conduction band, and holes are generated in the valence band. Photocatalytic activity is known in which organic substances in the atmosphere are decomposed by an oxidation-reduction action based on electron transfer generated by these excited electrons and holes, and a bactericidal effect is exhibited. Various attempts have been made to industrially utilize this bactericidal effect. Have been done.

However, it is difficult to form a titanium oxide layer having a high photoactive catalyst on the surface of a substrate such as a polyester film.

[0004] In the conventional method, one method is to form a titanium oxide film by air oxidation or anodization of the surface of a pure titanium plate. However, this method is difficult to oxidize. Has a disadvantage that it is difficult to obtain a good function.

As another method, a method of depositing titanium oxide on a substrate surface by a CVD method or performing plasma irradiation (Japanese Patent Application Laid-Open No. Hei 6-210170) is known, but all of these methods are expensive. There is also a disadvantage that it cannot be applied depending on the type of the substrate.

Further, a method of adhering titanium oxide powder to a base material via a binder has been attempted, but the binder itself is oxidatively decomposed by the photocatalytic action of titanium oxide, and falls off from the base material after several months. There is a problem that it cannot be used for industrial use.

In recent years, a method of forming a titanium oxide thin film on a glass tube surface from a titanium alkoxide by a sol-gel method has been disclosed. In this method, a solution obtained by adding a certain organic polymer to an alcohol solution of an alkoxide is applied to a substrate, the organic polymer is thermally decomposed and removed by heat treatment, and crystallization of titanium oxide is performed. However, the problem remains that the starting material is expensive and that heat treatment at a high temperature is essential.

[0008] To solve these problems, a method using a composition comprising a hydrolyzate of a titanium oxide powder and a hydrolyzable silicon compound as a binder (JP-A-8-164334).
Is known as an effective method. However, the binder used in this method is inorganic (glassy), and although there is no problem of oxidative decomposition of the binder itself as in the above-mentioned organic binder, there is a problem that adhesion to a plastic substrate, particularly a polyester film is poor. is there.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem, to provide excellent adhesion between a photocatalytic functional layer made of titanium oxide and a polyester film as a base material, and to have a photocatalytic action (for example, surface To provide a laminated film having an antifouling effect, an antibacterial effect, and a hydrophilizing effect.

[0010]

SUMMARY OF THE INVENTION The present invention comprises, as a main component, an aqueous solution or a water dispersion of a polyester resin, an acrylic resin, and at least one resin selected from an acrylic resin and a vinyl resin-modified polyester resin. Is applied to at least one surface of the polyester film before completion of the orientation crystallization, followed by drying, stretching, and heat setting to provide a primer layer, and an average particle size of 0.001 on the primer layer. It is a laminated film provided with a photocatalytic functional layer comprising a composition composed of a hydrolyzate of a titanium oxide of about 0.5 μm and a hydrolyzable silicon compound represented by the formula (1).

[0011]

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. Hereinafter, the present invention will be described in detail.

[Polyester Film] The polyester in the present invention is a crystalline linear saturated polyester produced from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Preferable examples include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, and poly (1,4-cyclohexylene dimethylene terephthalate), and polyethylene terephthalate and polyethylene-2,6-naphthalate are particularly preferred. It is preferably exemplified.

Further, a copolymer in which some of these are substituted with other components, or a mixture with polyalkylene glycol or another resin may be used.

Further, various additives can be blended with the polyester. For example, sodium dodecylbenzenesulfonate or the like can be contained as an antistatic agent.

The polyester film in the present invention comprises:
For applications requiring transparency, it is preferable to use a polyester film having good transparency, and a transparent biaxially oriented polyester film is particularly preferred. For applications requiring light-shielding properties, it is preferable to use a polyester film containing a pigment, and a white biaxially oriented polyester film containing a pigment such as TiO ₂ or SiO ₂ is particularly preferable.

The polyester film in the present invention comprises:
It can be manufactured by a conventionally known method. For example, in the case of a biaxially oriented polyester film, the polyester is dried and then melted, extruded from a die (eg, a T-die, an I-die, etc.) onto a cooling drum and cooled to form an unstretched film. It can be manufactured by stretching and further heat setting. The thickness of the film is not particularly limited, but is preferably 5 to 250 μm. As the polyester film, a film containing no lubricant is preferred in terms of surface flatness, but contains a lubricant for controlling surface roughness, for example, inorganic fine particles such as calcium carbonate, kaolin, silica and / or precipitated fine particles of catalyst residue. It may be a film that has been let. In addition, additives such as a stabilizer, a dye, an ultraviolet absorber, and a flame retardant can be contained in the polyester film of the present invention, if desired.

[Primer Layer] The laminated film of the present invention mainly comprises an aqueous solution or an aqueous dispersion of a polyester resin, an acrylic resin, and at least one resin selected from an acrylic resin and a vinyl resin-modified polyester resin. After applying the composition as a component to at least one surface of the polyester film before completion of the orientation crystallization,
It is characterized by providing a primer layer by performing drying, stretching and heat setting.

When a photocatalytically active layer described later is directly applied on a polyester film without the presence of this primer layer, the adhesion of the obtained coating film to the polyester film is extremely low, and the subsequent processing and Considering that it is used as a product, there is a high possibility that the photocatalytic activity function is impaired due to falling off of the coating.

As the polyester resin used as the primer layer, the following polyvalent carboxylic acids and polyvalent hydroxy compounds can be exemplified as the constituent components thereof. That is, as the polycarboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid,
2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid,
5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic Acid monopotassium salts, and their ester-forming derivatives, and the like. Examples of the polyvalent hydroxy compound include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,
1,4-butanediol, 1,6-hexanediol,
2-methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, p
-Xylylene glycol, bisphenol A-ethylene glycol adduct, bisphenol A-1,2-propylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylol Propionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate and the like can be used. One or more of these compounds are appropriately selected, and a polyester resin is synthesized by a conventional polycondensation reaction.
In addition to the above, a composite polymer having a polyester component such as a polyester polyurethane obtained by chain-extending a polyester polyol with an isocyanate is also included in the polyester resin referred to in the present invention.

As the acrylic resin used as the primer layer, those containing alkyl acrylate or alkyl methacrylate as a main component are preferable. The component is 30 to 90 mol%, and is a copolymerizable vinyl monomer having a functional group. It is a water-soluble or water-dispersible resin containing 70 to 10 mol% of body components. Vinyl monomers having a functional group copolymerizable with an alkyl acrylate or an alkyl methacrylate have a carboxyl group or a salt thereof, an acid anhydride group, a sulfonic acid group or a salt thereof, an amide group or an alkylol group as a functional group. It is a vinyl monomer having an amide group, an amino group (including a substituted amino group) or an alkylolated amino group or a salt thereof, a hydroxyl group, an epoxy group and the like. Of these, particularly preferred are vinyl monomers having a carboxyl group or a salt thereof, an acid anhydride group, and an epoxy group. Two or more kinds of the above functional groups may be contained in the resin.
Examples of the alkyl group of the alkyl acrylate and the alkyl methacrylate include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, and a stearyl group. And a cyclohexyl group.

As the vinyl monomer having a functional group copolymerizable with an alkyl acrylate or an alkyl methacrylate, the following compounds having a functional group such as a reactive functional group, a self-crosslinkable functional group, and a hydrophilic group can be used. . Examples of the compound having a carboxyl group or a salt thereof, and an acid anhydride group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, metal salts of these carboxylic acids with sodium, ammonium salts, maleic anhydride, and the like. . Examples of the compound having a sulfonic acid group or a salt thereof include vinyl sulfonic acid, styrene sulfonic acid, metal salts of these sulfonic acids with sodium and the like, and ammonium salts. Examples of the compound having an amide group or an alkylolated amide group include acrylamide, methacrylamide, N-methylmethacrylamide, methylolated acrylamide, methylolated methacrylamide, ureido vinyl ether, β-ureido isobutyl vinyl ether, ureido ethyl acrylate, and the like. No. Examples of the compound having an amino group or an alkylolated amino group or a salt thereof include diethylaminoethyl vinyl ether, 2-aminoethyl vinyl ether, 3-aminopropyl vinyl ether, 2-aminobutyl vinyl ether, dimethylaminoethyl methacrylate, and dimethylaminoethyl. Vinyl ethers, those whose amino groups are methylolated,
Examples thereof include those quaternized with an alkyl halide, dimethyl sulfate, sultone, or the like. As the compound having a hydroxyl group, β-hydroxyethyl acrylate, β
-Hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, β-hydroxyethyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, Examples of the compound having an epoxy group, such as polypropylene glycol monomethacrylate, include glycidyl acrylate and glycidyl methacrylate. Other compounds having a functional group include vinyl isocyanate and allyl isocyanate.
Further, olefins such as ethylene, propylene, methylpentene, butadiene, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, vinyl trialkoxysilane, acrylonitrile,
Methacrylonitrile, vinylidene chloride, vinyl chloride, vinylidene fluoride, ethylene tetrafluoride, vinyl acetate, and the like are also examples of the vinyl monomer compound.

The acrylic resin and the vinyl resin-modified polyester resin used as the primer layer are water-soluble or water-dispersible resins, and the acrylic resin and the vinyl resin are polymerized in the water-soluble or water-dispersible polyester resin. Can be synthesized by Examples of the components constituting the polyester include the same polyvalent carboxylic acids and polyvalent hydroxy compounds as the polyester resins described above, and ester-forming derivatives of these compounds.
One or more of these compounds are appropriately selected to obtain a polyester resin by a conventional polycondensation reaction.
As the components constituting the acrylic resin and the vinyl resin, two or more kinds of the same alkyl acrylates or alkyl methacrylates as the above-mentioned acrylic resins and vinyl monomer compounds can be appropriately used. Examples of the water-soluble or water-dispersible resin of the acrylic resin and the vinyl resin-modified polyester resin in the present invention include those having a molecular structure such as a so-called acrylic graft polyester described in JP-A-1-165633. It is.

A necessary amount of a surfactant such as an anionic surfactant, a cationic surfactant, a nonionic surfactant or the like can be added to such a primer coating liquid, particularly an aqueous liquid.

As such a surfactant, the surface tension of the coating solution is 50 dyne / cm or less, preferably 40 dyne / cm.
/ Cm or less, and promotes wetting to the polyester film. For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene-fatty acid ester sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap , Alkyl sulfates, alkyl sulfonates, alkyl sulfosuccinates, quaternary ammonium chloride salts, alkylamine hydrochlorides and the like. Further, other additives such as an antistatic agent, an ultraviolet absorber, a pigment, an organic or inorganic filler, a lubricant, and an anti-blocking agent can be mixed as long as the effects of the present invention are not lost.

A primer layer can be provided by applying such a primer coating solution to at least one surface of a polyester film, followed by drying and, if necessary, by thermal crosslinking. The application of the primer layer is performed in a polyester film manufacturing process which is known to be characterized by a clean atmosphere. In particular, it is preferable to apply an aqueous coating solution to one or both surfaces of the polyester film before the crystal orientation is completed in this step. When performed in the process of separating and applying the film manufacturing process,
Unless the process has a particularly clean atmosphere,
It is not preferable because garbage, dust and the like are easily entangled, and the performance of the product may be impaired.

Here, the polyester film before the completion of the crystal orientation means an unstretched film obtained by heat-melting the polyester and solidifying it by rapid cooling to form a film. Uniaxially stretched film oriented in one of two directions (width direction), and further stretched and oriented at a low magnification in two directions, longitudinal and transverse (finally oriented in the longitudinal or transverse direction by re-stretching) Biaxially stretched film before crystallization is completed).

The solid content of the coating solution is not particularly limited, but is usually 30% by weight or less, and more preferably 10% by weight or less. The coating amount is 0.5 to ²⁰ g, preferably 1 to 10 g, per m ² of the running film.

As a coating method, any known coating method can be applied. For example, kiss coat method, berth coat method,
A die coating method, a reverse coating method, an offset gravure coating method, a myrbar coating method, a gravure coating method, a roll brushing method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method, or the like may be used alone or in combination.

In order to improve the wettability of the coating liquid to the polyester film before the completion of the crystal orientation, the surface of the polyester film may be activated by a known method such as corona discharge treatment.

The polyester film to which the coating liquid has been applied and before the completion of the crystal orientation is dried and led to steps such as stretching and heat setting. For example, a vertically uniaxially stretched polyester film to which an aqueous liquid has been applied is guided to a stenter and is horizontally stretched and thermally fixed. During this time, the coating liquid is dried and, if necessary, thermally crosslinked.

Conditions for oriented crystallization of the polyester film,
For example, stretching, heat setting, and the like can be performed under conditions conventionally accumulated in the art.

The primer layer according to the present invention exhibits excellent adhesion to a polyester film, and comprises a composition comprising titanium oxide and the hydrolyzate represented by the above formula (1) or the above formula (1). It has excellent adhesion to a layer composed of the hydrolyzate represented by 1).

[Photocatalytic Function Layer] The titanium oxide used in the present invention has a catalytic action on the oxidation-reduction of organic substances by irradiation with light having a specific energy. Hydrous titanium oxide, hydrated titanium oxide,
Includes those called 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,
The particle size is 0.001 to 0.
It needs to be 5 μm. This fine powder may be used as a dry powder, but it is desirable to prepare a dispersion in advance for uniform dispersion with a silica binder derived from a hydrolyzable silicon compound described later. Whether or not titanium oxide is well dispersed in the composition of the present invention greatly affects the photocatalytic function when a coating film is formed.

[0035] Titanium oxide is produced by various known methods. For example, 1. 1. a method of hydrolyzing a titanium compound such as titanyl sulfate, titanium chloride, or an organic titanium compound in the presence of a nucleating species, if necessary; 2. a method of adding an alkali to a titanium compound such as titanyl sulfate, titanium chloride, or an organic titanium compound, if necessary, in the presence of a nucleation seed to neutralize the compound; 3. a method of vapor-phase oxidation of titanium chloride, an organic titanium compound or the like; Examples of the method include firing the titanium oxide obtained by the above method 1 or 2. In particular,
Titanium oxide obtained by the method 2 is preferable because of its high photocatalytic function. In order 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 by 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. PH 0.5 when placed under acidic conditions
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.

The hydrolyzable silicon compound represented by the above formula (1) used in the present invention is an alkyl silicate, a silicon halide or a partially hydrolyzed product thereof. Methyl silicate as alkyl silicate,
Ethyl silicate, isopropyl silicate and the like are used. Each of these silicates is used in the form of a monomer or an oligomer formed by partial hydrolysis, and the oligomer is represented by the general formula Si _n O _n-1 (OR) _{2n + 2}
(Where n is 2 to 6, R is an alkyl group having 1 to 4 carbon atoms)
The alkyl silicate condensate represented by the formula is particularly preferred. These oligomers can also be used in a mixture.

As a catalyst for the partial hydrolysis, an acid,
Any of the alkalis can be used. When the titanium oxide dispersion is acidic, an alkyl silicate hydrolyzed with an acid is preferred. The dispersion solvent of the hydrolysis solution is water or one having 1 carbon atom.
~ 4 alcohols are used. Esters such as ethyl acetate are not preferred because they make the composition liquid unstable.
Since the silicon compound and its partial hydrolyzate used in the present invention are used for the purpose of binding titanium oxide, they are hereinafter referred to as silica binder.

The mixing of the titanium oxide and the silica binder can be carried out as appropriate. For example, a predetermined amount of an aqueous dispersion of titanium dioxide under acidic conditions is maintained at a liquid temperature of 10 to 50 ° C., and weighed. The alkyl silicate or partial hydrolyzate thus obtained is added dropwise over a period of time. After dropping,
The composition is reacted for 1 to 5 hours under stirring to prepare a composition liquid. When the alkyl silicate or the partial hydrolyzate is added, the hydrolysis catalyst may be added at the same time, 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 the dispersion medium, a water / alcohol mixed medium dispersion of titanium dioxide and a liquid obtained by hydrolyzing 50 to 1500% of an alkyl silicate or a partial hydrolyzate in an alcohol medium are mixed with stirring. To obtain the present composition.

In the present invention, the hydrolysis rate is calculated based on the amount of water used, where the hydrolysis rate is 100% when 1 mole of alkyl silicate 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, a hydrolysis rate of 100% is obtained when 1 mol of this condensate is used and n + 1 mol of water is used.
Calculate as%.

The ratio of titanium and silica in the composition of the present invention is preferably 96/4 to 30/70 in terms of weight ratio (TiO ₂ / SiO ₂ ) in terms of titanium dioxide and silicon dioxide, respectively. If the proportion of silica exceeds 70%, the photocatalytic function of the titanium oxide becomes small, and the practicality becomes poor. It is presumed that this is because the proportion of silica covering the surface of the titanium oxide particles increases, which hinders contact between the titanium oxide and the substance to be oxidatively decomposed. On the other hand, if the mixing ratio of silica is 4% or less, the adhesive strength between the substrate and the titanium oxide is not sufficient, and the silica and the titanium oxide easily fall off by touch or vibration, making it difficult to use industrially as a coating film. Become. A more preferable ratio of silica is 10 to
50%.

The solid content in the composition of the present invention is 3% by weight.
0% or less. Here, the solid content refers to the total amount of titanium oxide and silica in the entire composition, where titanium oxide is titanium dioxide, and silica is silicon (Si) in the alkyl silicate or oligomer thereof in the composition.
Use the value converted to O ₂ . Other components are water and / or
Alternatively, the composition is mainly composed of an organic solvent, and should be substantially removed by drying after applying the composition on the surface of the substrate. The preferred solid content concentration is 5 to 20%, and when it is 5% or less, the adhesion to the substrate becomes strong, but the thickness of the coating film, that is, the amount of titanium dioxide is insufficient, and the coating film can sufficiently exhibit the photocatalytic function. Cannot be formed. It is possible to increase the thickness of the coating film by two-layer coating or three-layer coating, but there is little industrial advantage in that two-layer coating is troublesome by lowering the solid content concentration. However, it can be used for special applications such as when a strong thin coating film is required even if the photocatalytic function is sacrificed.

On the other hand, if the solids content exceeds 30%, the dispersibility of the solids in the composition becomes poor, the storage stability of the composition is remarkably reduced, and gelation easily occurs in a few days.
Further, when the concentration is high, the film forming property is poor, and the adhesion of the formed film to the substrate is greatly reduced, and the film is peeled off when rubbed with a finger, which is not preferable.

A small amount of titanium alkoxide or 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 alkoxysilane or 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.

Such a composition is provided on the surface of the polyester film on which the primer layer is provided, and a preferred method is to apply a coating solution containing the composition.

That is, the method of applying the composition of the present invention to the surface of the base film on which the primer layer is provided, drying it, and optionally baking it 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 0.1-3μ
m, especially 0.3 to 2 μm, is suitable. 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. With such a thickness, the coating film can be made transparent, and a photoactive coating film can be formed on the surface without impairing the transparency and color of the substrate.

The coating film provided by the above method is 100 to 1
By drying at 80 ° C., a strong film that does not easily peel off even when rubbed with a nail can be formed.

Further, in the present invention, by providing a layer comprising a hydrolyzate of the hydrolyzable silicon compound represented by the above formula (1) between the primer layer and the photofunctional catalyst layer, the primer by photocatalysis can be obtained. This is preferable because oxidative decomposition of the layer can be completely prevented and the long-term durability of the laminated film is improved.

The hydrolyzable silicon compound is the same as or the same as the hydrolyzable silicon compound constituting the photocatalytic functional layer, and the layer can be formed by the same method.

By providing a layer composed of a hydrolyzate of such a hydrolyzable silicon compound, the adhesion between the primer layer and the photocatalytic functional layer is further improved.

The laminated film of the present invention can be used for a wide variety of applications due to its photocatalytic activity, adhesion between layers, and durability. For example, it can be used as a film for protecting glass or metal surfaces for the purpose of decomposing and removing organic substances and microorganisms attached to the surface. In addition, when pasted to a wall material or the like, the wall surface can be automatically purified, so that a sterilizing effect on the wall surface of a hospital or the like can be expected. Furthermore, it can be applied to prevention of fogging due to water droplets only by sticking to a mirror or a window glass.

For these applications, lamination and bonding with various objects such as glass, metal, plastic, etc.
Known adhesives and adhesives can be used, and they are particularly useful as a protective film having a photocatalytic activity function when applied to a structure already installed.

[0053]

The present invention will be described in more detail with reference to the following examples. In the examples, “parts” means “parts by weight”. The properties of the laminated film were measured and evaluated by the following methods.

(1) Adhesiveness A cellophane tape is attached to the photocatalytic function layer surface of the film.
After pressure bonding with a rubber roll, the cell surface was peeled off the cell surface vertically and quickly. Repeat this operation 5 times,
Evaluation was made according to the following criteria. ：: The coating film did not fall off five times. △-△: The coating film dropped off once. Δ: The coating film dropped off twice. × to Δ: The coating film has fallen off three times. ×: The coating film was dropped four times. XX: The coating film has fallen off five times.

The same evaluation was performed on the film after irradiating it with 1 mW / cm ² of ultraviolet light for one month.
◎ is attached.

(2) Decomposability of Aldehyde A sample was placed in a 0.8-liter glass container, and a quantity of acetaldehyde, which is a malodorous component, having a concentration of 100 ppm was introduced into the glass container and sealed. Next, after maintaining for 30 minutes without irradiating ultraviolet rays for 30 minutes, the sample was irradiated with black light light so that the ultraviolet intensity on the sample surface became 1 mW / cm ² . After irradiation for 60 minutes, the concentration of acetaldehyde in the glass container was measured and evaluated according to the following criteria. ：: less than 50 ppm Δ: 50 ppm or more and less than 75 ppm ×: 75 ppm or more

(3) Anti-fogging property 100 ml of water was put into a 500 ml beaker, and 30 ° C.
The sample film was covered with a beaker so that the photocatalytic function layer was on the inside, and the room temperature was kept at 8 ° C. or lower, observed for 7 days, and evaluated according to the following criteria. ：: There was no fogging on the film surface. X: Fogging occurred on the film surface.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.65 (containing 500 ppm of a lubricant) measured in o-chlorophenol at 35 ° C. was melt-extruded on a rotary cooling drum maintained at 20 ° C. and had a thickness of 480 μm. After obtaining a stretched film and then stretching it 3.5 times in the machine axis direction, an acrylic resin aqueous dispersion (methyl methacrylate component (65 mol%), ethyl acrylate component (28 mol%) , A copolymer of 2-hydroxyethyl methacrylate component (2 mol%) and N-methylol acrylamide component (5 mol%), Tg
= 45 ° C) as a solid content, and an aqueous dispersion of polyester resin (manufactured by Takamatsu Yushi Co., Ltd., Pesresin 200).
0, Tg = 68 ° C.) as a solid content, and 10 parts by weight as a solid content of an aqueous dispersion of crosslinked acrylic resin fine particles having an average particle size of 0.03 μm as a solid content, diluted with ion-exchanged water. The aqueous coating solution having a solid content concentration of 2.7% by weight was applied by a kiss coating method at an average application amount of about 3 g as a coating solution weight per 1 m ^{2 of the} film. Then stretch 3.9 times in the transverse direction while drying at 105 ° C,
Further, heat treatment was performed at 210 ° C. to obtain a primer-coated polyester film having a thickness of 38 μm.

A coating solution obtained by partially hydrolyzing ethyl silicate as a hydrolyzate of a hydrolyzable silicon compound (Colcoat 103X, manufactured by Colcoat Co., Ltd.) was applied onto the primer layer of the film to give a coating solution of 5 g / m ² . Coated with the coating amount and dried at 150 ° C. for 1 minute. Further, a composition of anatase-type titanium dioxide having an average particle size of 0.07 to 0.1 μm and ethyl silicate was further added to the composition.
A coating solution (ST-K03, manufactured by Colcoat Co., Ltd.) was prepared by dissolving a composition in a ratio of 50 parts / 50 parts in terms of iO ₂ / SiO ₂ into a solution having a solid content of 10%. And coated at an application amount of 5 g / m ² ,
C. for 2 minutes to obtain a laminated film. Table 1 shows the properties of the laminated film.

Example 2 The composition of the aqueous coating solution applied to one surface of the uniaxially stretched film was determined using a polyester resin aqueous dispersion (Z-465, manufactured by Ryogo Chemical Co., Ltd., Tg = 70 ° C.) as a solid content. 90 parts by weight and an average particle size of 0.05
A laminated film was obtained in the same manner as in Example 1, except that the aqueous dispersion of the crosslinked acrylic resin fine particles having a particle size of 10 μm was used as a solid content. Table 1 shows the properties of the laminated film.

Comparative Example 1 A laminated film was obtained in the same manner as in Example 1 except that no primer layer was provided on the uniaxially stretched film. Table 1 shows the properties of the laminated film. Poor adhesion due to no primer layer.

[0062]

[Table 1]

[0063]

According to the present invention, excellent adhesion between the photocatalytic functional layer made of titanium oxide and the polyester film as the base material is obtained, and the photocatalytic action (for example, antifouling effect of surface, antibacterial effect, hydrophilicity Layer effect) can be provided.

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 4D075 BB05Z BB24Z CA34 CA37 CA45 DB48 EA06 EA10 EA13 EB22 EB35 EB42 4F100 AA21C AA21H AH06C AH06D AK25A AK25J AK41A AK41B AK42 BA03 BA03 BA06 BA06 DE01H EJ05 EJ37 EJ38 EJ65A JA11B JB05 JC00 JK06 JL06 JL08C JL08H JM01A YY00C YY00H

Claims (3)

[Claims] 1. A composition comprising, as a main component, an aqueous solution or a water dispersion of a polyester resin, an acrylic resin, and at least one resin selected from an acrylic resin and a vinyl resin-modified polyester resin. After coating on at least one surface of the polyester film before the completion of the formation, a primer layer is provided by performing drying, stretching, and heat setting, and the average particle size is 0.00
A laminated film provided with a photocatalytic functional layer comprising a composition comprising 1 to 0.5 μm of titanium oxide and a hydrolyzate of a hydrolyzable silicon compound represented by the 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. ) 2. The laminated film according to claim 1, wherein a layer made of a hydrolyzable silicon compound represented by the formula (1) is provided between the primer layer and the photocatalytic functional layer. 3. The laminated film according to claim 1, wherein the polyester film is a polyethylene terephthalate film or a polyethylene-2,6-naphthalate film.