JPWO1999030905A1 - Laminated film for preventing glass from shattering - Google Patents

Abstract

(57) [Abstract] A laminated film for preventing shattered glass, comprising: (A) a biaxially oriented polyester film made of a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in at least 80 mol% of all repeating units; (B) an adhesive coating film present on at least one side of the biaxially oriented polyester film; (C) a hard coat layer present on the adhesive coating film; and (D) an anti-reflection layer present on the hard coat layer. This laminated film has excellent adhesion, good surface hardness, and abrasion resistance, and also has sufficient transparency, anti-reflection properties, and glass shatter prevention capabilities.

Description

The present invention relates to a laminated film for preventing glass from shattering. More specifically, the present invention relates to a laminated film for preventing glass from shattering, which has excellent adhesiveness, scratch resistance, and impact resistance and is suitable as a surface protective material for window glass, showcases, microwave oven doors, plasma display panels, and cathode ray tubes of televisions and monitors.

Prior Art Biaxially oriented films of polyethylene-2,6-naphthalenedicarboxylate have superior mechanical properties compared to biaxially oriented films of polyethylene terephthalate.
It is attracting attention for its heat resistance and chemical resistance, making it suitable for a variety of uses.

In particular, recently, attention has been focused on its use as a surface protective material with shatterproof effect for window glass, showcases, microwave oven doors, plasma display panels, and cathode ray tubes of televisions and monitors.
It is required to have excellent abrasion resistance, sufficient transparency, anti-reflection properties, and glass shatter prevention properties.

In order to meet these requirements, polyester film is hard coated (HC
Attempts have been made to laminate a reflective (AR) layer and an anti-reflection (AR) layer on the polyester film, but satisfactory results have not been obtained due to insufficient adhesion to the polyester film.

In Japanese Patent Laid-Open No. 7-156358, a polyester film is coated on the surface thereof with a film substantially made of an aqueous polyester having a second-order transition temperature of 40 to 85° C. and having a thickness of 0.0 mm.
a medium layer of an in-mold transfer film with a coating layer of 5 to 0.3 μm;
For example, an easily adhesive film that exhibits good adhesion to a medium layer made of melamine resin has been disclosed.

Japanese Patent Laid-Open No. 63-194948 discloses a method for coating the surface of a polyester film with polyurethane, acrylic resin, fatty acid amide or bisamide, and a particle size of 0.
A surface roughening material (D) having a surface roughness of 15 μm or less and a center line average surface roughness (Ra) of 0
A flat and slippery polyester film having a thickness of 0.002 to 0.01 μm is disclosed.

Furthermore, Japanese Patent Publication No. 7-80281 discloses a plastic laminate comprising a polyethylene terephthalate layer, a polyester resin layer having a heat of fusion of 0.2 to 5 cal/g, and a radiation-curable layer.
The composition comprises a radiation-cured reaction product of a composition containing a monomer having at least one (meth)acryloyloxy group and an N-vinylpyrrolide.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a laminated film for preventing glass shattering, which has excellent adhesion, good surface hardness, scratch resistance, etc., and also has sufficient transparency, anti-reflection properties, and glass shatter prevention properties.

Another object of the present invention is to provide a precursor laminate film having excellent properties for the laminate film of the present invention, and a base film therefor.

Further objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are achieved, firstly, by a laminated film for preventing glass shattering, comprising: (A) a biaxially oriented polyester film made of a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in an amount of at least 80 mol % of all repeating units; (B) an adhesive coating film present on at least one side of the biaxially oriented polyester film, wherein the adhesive coating film is made of a composition containing a water-soluble or water-dispersible polyester having a second-order transition temperature of 40 to 85°C and at least one amide compound selected from the group consisting of fatty acid amides and fatty acid bisamides; (C) a hard coat layer present on the adhesive coating film, provided that when adhesive coating films are present on both sides of the biaxially oriented polyester film, the hard coat layer is present only on one of the adhesive coating films; and (D) an anti-reflection layer present on the hard coat layer.

The above objects and advantages of the present invention are secondly achieved by a precursor laminate film for preventing glass from shattering, comprising: (A) a biaxially oriented polyester film made of a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in an amount of at least 80 mol % of all repeating units; and (B) an adhesive coating film present on at least one surface of the biaxially oriented polyester film, wherein the adhesive coating film comprises a composition containing a water-soluble or water-dispersible polyester having a second-order transition temperature of 40 to 85°C and at least one amide compound selected from the group consisting of fatty acid amides and fatty acid bisamides.

Furthermore, the above objects and advantages of the present invention are thirdly achieved by a base film for a laminated film for preventing glass from shattering, characterized in that (A) (a) the base film comprises a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in an amount of at least 80 mol % of all repeating units, (b) the base film has a planar orientation coefficient of 0.250 or more, and (c) the base film has an intrinsic viscosity of 0.45 dL/g or more.

DETAILED DESCRIPTION OF THE INVENTION The laminated film and precursor laminated film of the present invention use a biaxially oriented polyester film as a base film.

This biaxially oriented polyester film is made of a copolyester (hereinafter sometimes referred to as PEN) containing ethylene-2,6-naphthalenedicarboxylate repeating units in an amount of at least 80 mol % of all repeating units.

That is, this PEN may be a homopolymer containing ethylene-2,6-naphthalenedicarboxylate as the sole repeating unit, or may contain an acid component other than 2,6-naphthalenedicarboxylic acid and/or a glycol component other than ethylene glycol, with the proportion of ethylene-2,6-naphthalenedicarboxylate repeating units being 80 mol % or less. If the proportion of polymerized units other than ethylene-2,6-naphthalenedicarboxylate repeating units is less than 20 mol %, the inherent properties of the PEN film are not significantly lost and excellent glass shatterproof performance is achieved when used at high temperatures, which is preferred.

If the proportion of polymerized units other than ethylene-2,6-naphthalenedicarboxylate repeating units exceeds 20 mol%, the original properties of the polyethylene-2,6-naphthalenedicarboxylate film will be lost, resulting in insufficient impact resistance and the inability to ensure glass shatter prevention performance.

The content of ethylene-2,6-naphthalenedicarboxylate repeating units is
More preferably, it is at least 85 mol %, and particularly preferably at least 90 mol %.

Examples of the acid component other than 2,6-naphthalenedicarboxylic acid include dicarboxylic acids such as oxalic acid, adipic acid, phthalic acid, sebacic acid, dodecanedicarboxylic acid, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, phenylindanedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and diphenyletherdicarboxylic acid; p-hydroxybenzoic acid;
-oxyethoxybenzoic acid and other hydroxycarboxylic acids.

Examples of glycol components other than ethylene glycol include propylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexanemethylene glycol, neopentyl glycol, ethylene oxide adducts of bisphenol sulfone, ethylene oxide adducts of bisphenol A, diethylene glycol, and polyethylene glycol.
Preferred examples of the alcohols include hydric alcohols.

Furthermore, PEN may be one in which some or all of the terminal hydroxyl and/or carboxyl groups have been blocked with a monofunctional compound such as benzoic acid or methoxypolyalkylene glycol, or it may be one in which a very small amount of a trifunctional or higher functional ester-forming compound such as glycerin or pentaerythritol is copolymerized within a range in which a substantially linear polymer is obtained.

The biaxially oriented polyester film of the present invention may contain additives such as stabilizers, lubricants, or flame retardants.

In order to impart slipperiness to the film, it is preferable to contain a small proportion of inert fine particles. Examples of such inert fine particles include inorganic particles such as spherical silica, porous silica, calcium carbonate, alumina, titanium dioxide, kaolin clay, barium sulfate, and zeolite, and organic particles such as silicone resin particles and cross-linked polystyrene particles. Synthetic inorganic particles are preferred over natural products because of their uniform particle size, and inorganic particles of any crystal form, hardness, specific gravity, and color can be used.

The average particle size of the inert fine particles is preferably in the range of 0.05 to 5.0 μm, and more preferably 0.1 to 3.0 μm.

The content of the inert fine particles is preferably 0.001 to 1.0% by weight, and more preferably 0.03 to 0.5% by weight.

The inert fine particles added to the film may be a single component selected from the above-mentioned examples, or may be a multi-component containing two or more components.

The timing of adding the inert fine particles to PEN is not particularly limited as long as it is added at any stage up to the stage of PEN film formation. For example, they may be added at the polymerization stage or during film formation.

The biaxially oriented polyester film of the present invention can be produced by biaxially stretching an unstretched film obtained by a conventional method, and then heat-setting the film within a specific temperature range.

For example, an unstretched film is biaxially stretched at a temperature of Tg to (Tg+60)°C at a stretching ratio of 2.5 to 5.0 times in both the longitudinal and transverse directions, and stretched to a temperature of (Tg+50) to (Tg+140)°C.
The film is heat-set at a temperature of 0.1°C for 1 to 100 seconds. The stretching can be carried out by a commonly used method, for example, a method using a roll or a method using a stenter. The film may be stretched in the machine direction and the cross direction simultaneously, or may be stretched in the machine direction and the cross direction sequentially.
g represents the glass transition temperature of the polymer.

The ratio of the longitudinal stretching ratio to the transverse stretching ratio (longitudinal stretching ratio/transverse stretching ratio) is 0.85 to 1.1.
It is particularly preferred that the thermal setting temperature is (Tg+60) to (Tg+110)°C.

After biaxial stretching, the film may be stretched again in the machine direction and/or the transverse direction.

The biaxially oriented polyester film preferably has a planar orientation coefficient of 0.250 or more. If the planar orientation coefficient is less than 0.250, the glass shatterproof performance of the laminate is reduced, and the thickness unevenness of the film worsens, resulting in non-uniform light transmission when laminated to a cathode ray tube or the like. The planar orientation coefficient is more preferably in the range of 0.252 to 0.275, and particularly preferably 0.255 to 0.270.

The biaxially oriented polyester film is preferably made of PEN having an intrinsic viscosity of 0.45 dl/g or more.

Furthermore, if the intrinsic viscosity is less than 0.45 dL/g, burrs and cracks will occur on the edge when the film is cut, which is undesirable as it reduces workability in the processing step. The preferred range of intrinsic viscosity is 0.48 to 0.90 dL/g, and the most preferred range is 0.
.50 to 0.80 dl/g.

The biaxially oriented polyester film preferably has a sum of Young's moduli in two perpendicular directions on the film surface, for example, the machine direction and the transverse direction, of 900 kg/mm ² or more and a difference of 100 kg/mm ² or less.

If the sum of the Young's moduli in the two orthogonal directions is less than 900 kg/ ^mm2 , the glass shatter prevention performance of the laminate is likely to be insufficient.
kg/mm ² , and particularly preferably 1000 to 1500 kg/mm ² .

Furthermore, if the absolute value of the difference in Young's modulus exceeds 100 kg/ ^mm² , the strength of the film in only one direction is likely to decrease, the laminate is likely to tear, and the glass shatterproof performance is likely to decrease. A more preferable absolute value of the difference in Young's modulus is 0 to 50 kg/ ^mm² .

The biaxially oriented polyester film preferably has a thickness in the range of 50 to 350 μm. If it is less than 50 μm, the glass shatter prevention ability tends to be insufficient.
If the thickness exceeds 70 to 200 mm, it becomes difficult to bond the film to glass.
The thickness is preferably 50 μm, and particularly preferably 90 to 230 μm.

The biaxially oriented polyester film also preferably has a haze of 5% or less. If the haze exceeds 5%, the film becomes noticeably cloudy and transparency decreases, which is undesirable. A preferred haze is 3% or less.

In addition, the biaxially oriented polyester film has a centerline average surface roughness (Ra) of 10n
If the thickness exceeds 10 nm, the surface reflection due to the surface irregularities becomes visible to the naked eye and the transparency tends to decrease, which is not preferable.
More preferably, a is 8 nm or less, and particularly preferably 7 nm or less.

The laminate film and precursor laminate film of the present invention have an adhesive coating on at least one surface of the biaxially oriented polyester film, which adhesive coating comprises a composition containing a water-soluble or water-dispersible polyester having a second-order transition temperature of 40 to 85°C and at least one amide compound selected from the group consisting of fatty acid amides and fatty acid bisamides.

When the second-order transition temperature Tg of the water-soluble or water-dispersible polyester is less than 40°C,
The resulting film has low heat resistance and poor blocking resistance. On the other hand, if the temperature exceeds 85°C, the adhesiveness becomes poor. The second order transition temperature is preferably 4.
5 to 80°C.

The polyester contains the following polycarboxylic acids and polyhydroxyl compounds as constituents: 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,
Examples of polyhydric hydroxy compounds that can be used include p-hydroxybenzoic acid, monopotassium trimellitic acid salt, and ester-forming derivatives thereof. Examples of polyhydric hydroxy compounds that can be used include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-dimethylbenzyl alcohol, and the like.
Examples of compounds that can be used include 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, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, and potassium dimethylolpropionate. One or more of these compounds can be appropriately selected and used to synthesize a polyester resin by a conventional polycondensation reaction. In addition to the above, composite polymers containing polyester components, such as polyester polyurethanes obtained by chain-extending polyester polyols with isocyanates, can also be used as the polyester.

The water-soluble or water-dispersible polyester is present in the coating composition in an amount of 20 to 97%.
It can be contained in a weight percent.

As the amide compound, fatty acid amides and fatty acid bisamides are used.

The fatty acid amide is represented by the following formula:¹CONH₂ Here, R¹is a saturated or unsaturated aliphatic group having 6 to 22 carbon atoms, and those represented by the following are preferred.

Furthermore, the fatty acid bisamide is preferably ^{one represented by the following formula: R2CONHR3NHCOR4 , wherein R2} and ^R4 are each independently a saturated or unsaturated aliphatic group having 6 to 22 carbon atoms, and ^R3 is a saturated or unsaturated aliphatic group having 1 to 15 carbon atoms.

Of these, fatty acid bisamides are more preferred. Examples of fatty acid amides include linoleic acid amide, caprylic acid amide, and stearic acid amide.

Furthermore, as the fatty acid bisamide, an N,N'-alkylene bisamide having a molecular weight of 200 to 800 is preferred, and specific examples thereof include N,N'-methylenebisstearic acid amide, N,N'-ethylenebispalmitic acid amide, and N,N'-methylenebislauric acid amide.

Among the above amide compounds, R ³ is a methylene group (CH ₂ ) or an ethylene group (C
Particularly preferred are fatty acid bisamides having the formula (H ₂ CH ₂ ).

The above amide compounds can be used alone or in combination of two or more.

The content of these amide compounds in the composition that forms the coating film is preferably 3 to 10% by weight. If the content of the amide compound is too low, sufficient adhesive strength cannot be obtained, and slip properties and blocking resistance tend to decrease, while if the content is too high, adhesion between the film and the coating film decreases, the coating film becomes embrittled, and haze increases.

It is preferable to add 5 to 30% by weight of a lubricant, i.e., inert fine particles having an average particle size of 0.15 .mu.m or less, to the adhesive coating film of the present invention.

Examples of the inert fine particles include inorganic fine particles such as calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, silicon oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, tin oxide, antimony trioxide, carbon black, and molybdenum disulfide; and organic fine particles such as acrylic crosslinked polymers, styrene crosslinked polymers, silicone resins, fluororesins, benzoguanamine resins, phenolic resins, nylon resins, and polyethylene wax.

Such inert fine particles not only roughen the surface of the coating film, but also have the effect of reinforcing the coating film itself, and further have the effect of imparting anti-blocking properties to the coating film, thereby imparting excellent slip properties to the film.

These inert fine particles are preferably contained in the composition for forming the coating film in an amount of 5 to 30% by weight, and in particular, when using fine particles with a relatively large particle size of 0.1 μm or more, the range of 5 to 10% by weight is preferred, and when using fine particles with an average particle size of 0.
When fine particles having a relatively small particle size of 0.1 to 0.1 μm are used, 8 to 30% by weight
The range is preferred.

The coefficient of friction (μs) of the adhesive coating film in the present invention is preferably 0.8 or less.

The composition used in the present invention is used in the form of an aqueous solution, aqueous dispersion, or emulsion to form a coating film. In the case of a water-dispersible polyester, a small amount of organic solvent may be added as a dispersing aid. In order to form a coating film, other resins other than the polyester, surfactants, antistatic agents, antifoaming agents,
Coating improvers, thickeners, organic lubricants, foaming agents, dyes, pigments, ultraviolet absorbers, etc. may be added.

As the surfactant, a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant can be added in a required amount. Such surfactants are preferably those which can reduce the surface tension of the aqueous coating liquid to 40 dyne/cm or less and promote wetting of the polyester film, such as polyoxyethylene alkylphenyl ether, polyoxyethylene-fatty acid ester,
Examples of such surfactants include sorbitan fatty acid esters, glycerin fatty acid esters, fatty acid metal soaps, alkyl sulfates, alkyl sulfonates, alkyl sulfosuccinates, quaternary ammonium chloride salts, alkylamine hydrochlorides, and betaine surfactants.

The antistatic agent can be an anionic antistatic agent, a cationic antistatic agent, a nonionic antistatic agent, an amphoteric antistatic agent, a polymeric antistatic agent, or the like, and can be added in a required amount. Examples of such antistatic agents include glycerin fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamines, polyoxyethylene alkylamine fatty acid esters, N,N'-bis(2-hydroxyethyl)alkylamines, alkyldiethanolamides, alkylsulfonates,
Alkylbenzene sulfonates, alkyl phosphates, tetraalkylammonium salts, trialkylbenzylammonium salts, alkyl betaines, alkyl imidazolium betaines, polyethylene oxides, polyether amide imides,
Ethylene oxide-epihalohydrin copolymer, quaternary ammonium base-containing (meth)acrylate copolymer, quaternary ammonium base-containing maleimide copolymer, 4
Examples of the copolymer include ammonium salt group-containing methacrylimide copolymer, sodium polystyrene sulfonate, and carbobetaine graft copolymer.

In addition, the easy-to-adhere coating film has properties such as adhesion (blocking), water resistance, solvent resistance,
To improve mechanical strength, the coating film may contain a crosslinking agent such as an isocyanate compound, an epoxy compound, an oxazoline compound, an aziridine compound, a melamine compound, a silane coupling agent, a titanium coupling agent, or a zircoaluminate coupling agent. If the resin component of the highly adhesive coating film has crosslinking reaction sites, the coating film may contain a reaction initiator such as a peroxide or an amine, or a sensitizer in the photosensitive resin.

The coating solution can be applied to the biaxially oriented polyester film at any stage, but is preferably applied during the film production process, and more preferably applied to the film before the orientation crystallization is complete.

Here, the film before the crystal orientation is completed includes an unstretched film, a uniaxially oriented film obtained by orienting an unstretched film in either the longitudinal or transverse direction, and a film that has been stretched and oriented at a low ratio in both the longitudinal and transverse directions (a biaxially stretched film before it is finally re-stretched in the longitudinal or transverse direction to complete the orientation crystallization).

Among them, unstretched films or uniaxially stretched films oriented in one direction are
It is preferred that the coating solution of the composition is applied, and then the film is stretched longitudinally and/or transversely and heat-set. The solids concentration of the coating solution is usually 0.1 to 30% by weight, more preferably 1 to 10% by weight.

When applying a coating liquid to a film, it is preferable to subject the film surface to a physical treatment such as corona surface treatment, flame treatment, or plasma treatment as a pretreatment to improve coatability, or to use a coating composition together with a chemically inactive surfactant. Such surfactants promote wetting of the aqueous coating liquid onto the film, and examples thereof include anionic and nonionic surfactants such as polyoxyethylene alkylphenyl ethers, polyoxyethylene-fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, fatty acid metal soaps, alkyl sulfates, alkyl sulfonates, and alkyl sulfosuccinates.

The amount of the coating solution to be applied is preferably 0.5 to 50 g per 1 ^m2 of film, and the thickness of the coating film (as solid content after drying) is preferably 0.02 to 0.3 μm, more preferably 0.0
If the coating thickness is too thin, the adhesive strength will be insufficient, whereas if it is too thick, blocking of the base film may occur or the haze value of the laminate may become high.

Any known coating method can be used as the coating method. For example, roll coating, gravure coating, roll brushing, spray coating, air knife coating, impregnation, curtain coating, etc. can be used alone or in combination. The coating film may be formed on only one side or both sides of the film, as necessary.

In the present invention, a hard coat layer is laminated on the surface of the base film on which the coating film has been applied. In this case, when the coating film is present on both sides of the base film, the hard coat layer is laminated on only one side.

As this hard coat layer, a commonly used hard coat layer such as a radiation curable type, a silane type, etc. is usable, and a radiation curable type hard coat layer is particularly preferred, and an ultraviolet curable type hard coat layer is particularly preferred.

Examples of ultraviolet-curable compositions used to form the hard coat layer include ultraviolet-curable compositions such as urethane-acrylate, epoxy-acrylate, and polyester-acrylate. These ultraviolet-curable compositions are described, for example, in Japanese Patent Publication No. 7-80281 and "New UV/EB Curing Technology and Application Development" (
24-42) (CMC Co., Ltd., published March 25, 1997).

To laminate a hard coat layer onto an adhesive coating film, a composition is applied onto the coating film,
The composition may be cured by heating, irradiating with radiation (for example, ultraviolet light), etc. The thickness of the hard coat layer is not particularly limited, but is usually about 1 to 15 μm.

In the laminated film of the present invention, an anti-reflection layer is further formed on the hard coat layer thus formed.

The anti-reflection layer may be made of a laminate in which oxide layers with a high refractive index and oxide layers with a low refractive index are alternately laminated.
The refractive index is, for example, 1.3 to 2.2.

For example, a low refractive index layer (SiO ₂ , 30 nm) - a high refractive index layer (TiO ₂ , 30 nm)
m) - low refractive index layer ( _SiO2 , 30 nm) - high refractive index layer ( _TiO2 , 100 nm
) - low refractive index layer (SiO ₂ , 100 nm), high refractive index layer (
ITO, 20 nm) - low refractive index layer (AlSiO, 20 nm) - high refractive index layer (IT
a layer structure of a low refractive index layer (AlSiO, 88 nm) and a low refractive index layer (AlSiO, 88 nm);
Examples include a layer structure of high refractive index conductive layer (ITO, 20 nm)-low refractive index layer ( _SiO2 , 20 nm)-high refractive index conductive layer (ITO, 93 nm)-low refractive index layer ( _SiO2 , 93 nm).

In the present invention, an optional anti-reflection layer can be applied, and is usually deposited on the hard coat layer by sputtering.

The laminated film of the present invention, in which a hard coat layer and an anti-reflection layer are provided on the adhesive coating film by the above-mentioned method, preferably has a haze of 5% or less.
If the haze exceeds 5%, the laminate will be very cloudy, which may make it difficult to use in areas where transparency is required, such as cathode ray tubes, window glass, etc. A more preferable range of haze is 3% or less.

The laminated film of the present invention is applied to a glass surface to prevent glass from scattering when the glass is broken, and is applied to the glass surface so that the anti-reflection layer is the outermost layer.

When the biaxially oriented polyester film serving as the base film has an adhesive coating on both sides, the film can be attached to a glass surface by providing a pressure-sensitive adhesive layer on the adhesive coating. When the biaxially oriented polyester film has an adhesive coating on only one side, the film can be attached to a glass surface by providing a pressure-sensitive adhesive layer on the side without the adhesive coating. It is more preferable to provide an adhesive coating on both sides, as this strengthens the adhesion between the laminated film and the pressure-sensitive adhesive layer.

Examples of adhesives include rubber-based adhesives such as latex-based adhesives, butyl rubber-based adhesives, and styrene-based block copolymer-based adhesives, as well as acrylic-based adhesives, polyether-based adhesives, and silicone-based adhesives. There are no particular limitations on the type of adhesive, as long as it can firmly adhere the laminated film to the glass surface and the adhesive itself can ensure transparency.

Furthermore, methods for curing adhesives to firmly adhere laminated films include ultraviolet irradiation, electromagnetic wave irradiation, and heating, and are not particularly limited. However, curing methods using ultraviolet irradiation from the laminated film side are not suitable for the present invention because the biaxially oriented film in the present invention blocks the ultraviolet light, preventing the ultraviolet light from reaching the adhesive, and the adhesive does not cure.

The pressure-sensitive adhesive layer is preferably formed by a coating method. A release film is preferably formed on the pressure-sensitive adhesive layer for the purpose of protecting the layer. The release film is peeled off before use, and the laminate is then attached to glass so that the pressure-sensitive adhesive layer is in contact with the glass.

The glass surface to which the laminated film is applied can be, for example, the glass surface of an image display device such as a cathode ray tube or a plasma display.

Therefore, by using the laminate film of the present invention, for example, an image display device can be provided in which the laminate film of the present invention is attached to the outside of the glass surface of the image display device so that the anti-reflection layer of the laminate film is the outermost layer.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. Physical properties were measured by the following methods.

(1) Purity Measurement of Ethylene-2,6-naphthalenedicarboxylate A film sample is dissolved in a measurement solvent (CDCl ₃ :CF ₃ COD=1:1), and then subjected to ¹ H-NMR measurement, and the purity is calculated from the integral ratio of each signal obtained.

(2) Young's modulus: A film is cut into a sample 10 mm wide and 150 mm long, and pulled using an Instro-type universal tensile testing device with a chuck distance of 100 mm at a pulling rate of 10 mm/min and a chart speed of 500 mm/min. Young's modulus is calculated from the tangent to the rising part of the obtained load-elongation curve.

(3) Planar orientation coefficient (ns) Using an Abbe refractometer (manufactured by Atago Co., Ltd.), the refractive indices ( _nMD , _nTD , _nZ ) in the longitudinal direction (MD), width direction (TD), and thickness direction (Z) of the film are determined using Na-D line at 25°C, and calculated using the following formula: The film sample is measured on both the front and back sides, and the average value of the calculated _nS is taken as the planar orientation coefficient ( _ns ).

n_S= {(n_MD+n_TD)/2}-n_Z (4) Intrinsic viscosity Measured at 25°C using o-chlorophenol as a solvent (unit: dl/
g).

(5) Surface Roughness (Ra) The front and back surfaces of the film are measured with a surface roughness meter (Surfcom 111A manufactured by Tokyo Seimitsu Co., Ltd.) and the measured surface roughness (Ra) is expressed in nm.

(6) Haze: Using a haze measuring instrument (NDH-20) manufactured by Nippon Denshoku Industries Co., Ltd., the haze was measured in accordance with JIS K 6
The haze value is the total haze value of a single film or a laminated film measured in accordance with the method of JIS No. 714.

(7) Coefficient of friction (μs) According to ASTM D1894-63, the coefficient of static friction between the coated surface and the polyethylene-2,6-naphthalenedicarboxylate film (non-coated surface) was measured using a slippery measuring instrument manufactured by Toyo Tester Co., Ltd., and this value was taken as the coefficient of friction (μs).
The sled plate is a glass plate and the load is 1 kg. The slipperiness of the film is evaluated according to the following criteria.

◎: Friction coefficient (μs) ≦ 0.5...Excellent slipperiness ○: 0.5< Friction coefficient (μs) ≦ 0.8...Good slipperiness ×: 0.8< Friction coefficient (μs)...Poor slipperiness (8) Adhesion High-adhesion coating of polyethylene-2,6-naphthalenedicarboxylate film
A hard coat layer of 5 μm in thickness was formed on the film surface, and a grid cross-cut (1 mm²
100 squares) and then 24mm wide cellophane tape (Nichiban
After rapidly peeling it off at a peeling angle of 180 degrees, the peeled surface was observed.
Evaluation is based on the following criteria.

5: Peeled area less than 10%...very good adhesion 4: Peeled area 10% or more but less than 20%...good adhesion 3: Peeled area 20% or more but less than 30%...lower usable adhesion level 2: Peeled area 30% or more but less than 40%...poor adhesion 1: Peeled area more than 40%...very poor adhesion (9) Scratch Resistance Using a pencil hardness tester manufactured by Marubishi Scientific Machinery Manufacturing Co., Ltd., a pencil scratch test is performed on the surface of the laminate film (the hard coat side if a hard coat layer is applied) according to a method in accordance with JIS K 5400. The scratch test is performed by holding the pencil perpendicular to the film surface and pressing it with a load of 500 g. The scratch resistance of the film is evaluated according to the following criteria.

○: 2H or more, good scratch resistance ×: H or less, poor scratch resistance (10) Reflectance The ratio of the reflected light beam to the incident light beam perpendicular to the laminate surface is
The reflectance is measured in the wavelength range of 100 nm and the average value is taken as the reflectance.

(11) Blocking Resistance Two films were stacked together so that the coated surface and the non-coated surface were in contact with each other.
A pressure of 6 kg/ ^cm2 was applied for 17 hours in an atmosphere of 60°C x 80% RH, and then the film was peeled off (peel direction: 180° direction, peel speed: 100 mm/min).
The blocking resistance is evaluated based on the peeling force (g/5 cm width) according to the following criteria.

◎: Peeling force < 10...extremely good blocking resistance ○: 10≦peeling force < 15...good blocking resistance △: 15≦peeling force < 20...slightly poor blocking resistance ×: 20≦peeling force...poor blocking resistance (12) Impact resistance (effect of preventing glass shattering) The impact resistance of the film is measured according to the bell drop impact test method of JIS K 7211 and calculated as impact energy (E50). (However, the diameter of the tip of the weight used was 4 mm.) Evaluation of impact resistance (effect of preventing glass shattering) ○ (Good): Impact energy (E50) ≥ 1.00 (J) △ (Usable): 1.00 > Impact energy (E50) ≥ 0.45 (J) × (Unusable): Impact energy (E50) < 0.45 (J) Example 1 Polyethylene-2,6-naphthalenedicarboxylate having an intrinsic viscosity of 0.60 dl/g was extruded through a die and cooled on a cooling drum in the usual way to form an unstretched film. This was then stretched 3.8 times in the machine direction, and one side of the film was coated with a coating composition having a concentration of 80% of the following.
The properties of the biaxially oriented polyester film are shown in Table 1.

<Coating composition> A coating composition containing terephthalic acid (90 mol%), isophthalic acid (6 mol%) and 5-
The composition of the film was: 80% by weight of a copolymer polyester (Tg=68°C) of potassium sulfoisophthalate (4 mol%), glycol components of ethylene glycol (95 mol%) and neopentyl glycol (5 mol%), N,N'-ethylenebiscaprylic acid amide (5 mol%), 10% by weight of acrylic resin particles (average particle size 0.03 μm), and 5% by weight of polyoxyethylene nonylphenyl ether. The film was then stretched 4.0 times in the transverse direction and heat-set at 210°C to obtain an adhesive film with a thickness of 150 μL/m. The coating thickness was 0.15 μm.

Next, a UV-curable composition having the following composition was uniformly applied onto the coating film using a roll coater so that the film thickness after curing would be 5 μm.

<UV curable composition> Pentaerythritol acrylate 45 wt% N-methylolacrylamide 40 wt% N-vinylpyrrolidone 10 wt% 1-hydroxycyclohexylphenyl ketone 5 wt% Then, the composition was cured by irradiating ultraviolet light from a high-pressure mercury lamp with an intensity of 80 W/cm for 30 seconds to form a hard coat layer. The adhesive strength at this time was evaluated as 4 according to the above-mentioned evaluation.

On this hard coat layer, a low refractive index layer (SiO ₂ , 30 nm), a high refractive index layer (TiO ₂ , 30 nm), a low refractive index layer (SiO ₂ , 30 nm), a high refractive index layer (T
A low refractive index layer (SiO ₂ , 100 nm) and a low refractive index layer (SiO ₂ , 100 nm) were formed in this order by sputtering.

The resulting laminate had a reflectance of 0.7%, which was low in reflection, and also had good scratch resistance and shatterproof effect against glass.

Comparative Example 1 A laminate was prepared under the same conditions as in Example 1, except that a coating composition not containing N,N'-ethylenebiscaprylic acid amide was used. The evaluation results of the laminate are shown in Table 3. This laminate had the same abrasion resistance and reflectance as in Example 1, but the adhesive strength evaluated in the same manner as in Example 1 was 2, indicating poor adhesive strength.

Examples 2 to 9 and Comparative Examples 2 to 4 Laminates were obtained in the same manner as in Example 1, except that the formulation of the coating composition in Example 1 was changed as shown in Table 2. The evaluation results of the laminates are shown in Table 3.

Examples 10 to 13: Laminates were obtained in the same manner as in Example 4, except that the amount of N,N'-methylenebisstearic acid amide in the coating composition was changed as shown in Table 2. The results are shown in Table 3, and all of the laminates had a good effect of preventing glass from shattering. Furthermore, when the amount of fatty acid bisamide was 3 to 10% by weight (Examples 11 and 12), the laminates were also excellent.
Particularly good adhesive strength was obtained for 2).

Examples 14 to 19 In Example 4, the lubricant in the coating composition and its amount added were changed as shown in Table 2. The results are shown in Table 3. The laminates of the present invention (Examples 14 to 19) showed good adhesive strength, glass shatter prevention effect, and easy lubricity.

Example 20: A U film having the following composition was applied to the coating of the adhesive polyester film obtained in Example 5.
The V curable composition was applied uniformly using a roll coater so that the film thickness after curing would be 5 μm.

<UV curing composition> Pentaerythritol triacrylate 20% by weight, N-methylol acrylamide 40% by weight, trimethylolpropane triacrylate 25% by weight, N-vinylpyrrolidone 10% by weight, P-phenoxydichloroacetophenone 5% by weight.Then, use a high-pressure mercury lamp with an intensity of 80 W/cm to irradiate ultraviolet light for 30 seconds to cure, and form a hard coat layer.The lamination strength at this time is 4.
On this hard coat layer, a high refractive index layer (ITO, 20 nm) and a low refractive index layer (A
SiO, 20 nm), high refractive index layer (ITO, 80 nm), low refractive index layer (AlS
The resulting laminate had a reflectance of 0.7%, which was low in reflection, and also had good scratch resistance and shatterproof effect.

Comparative Examples 5 and 6 Laminated films with different coefficients of friction (μs) were obtained in the same manner as in Example 4, except that the type and amount of lubricant in the coating composition was changed as shown in Table 2. The evaluation results of these films are shown in Table 3, and all of them were good in terms of glass shatter prevention. However, because the coefficient of friction (μs) exceeded 0.8, the films had poor lubricity and were insufficient in winding ability, handling ability, and blocking resistance.

Examples 21 to 23 and Comparative Examples 7 and 8 Laminates were prepared in the same manner as in Example 1, except that the film-forming conditions in Example 1 were changed to those shown in Table 1. The properties of these laminates are shown in Table 3.

Example 24 A laminate was prepared in the same manner as in Example 1, except that polyethylene-2,6-naphthalenedicarboxylate with an intrinsic viscosity of 0.55 dL/g was used. The intrinsic viscosity of the film in this example was 0.48 dL/g. The properties of this laminate are shown in Table 3.

Example 25 Copolymer polyester (ethylene-2,6-naphthalenedicarboxylate unit 90 mol %, bis(4-(2-hydroxyethoxy)phenyl)sulfone-2,6-naphthalenedicarboxylate unit 90 mol %; intrinsic viscosity 0.60 dl/g)
A laminate was prepared in the same manner as in Example 1, except that 10 mol% of PS-EO (abbreviated as PS-EO) was used. The intrinsic viscosity of the film in this example was 0.51 dL/g. The properties of this laminate are shown in Table 3.

Example 26 A laminate was prepared in the same manner as in Example 1, except that a copolymer polyester having an intrinsic viscosity of 0.60 dL/g (ethylene-2,6-naphthalenedicarboxylate unit 85 mol%, ethylene isophthalate unit (abbreviated as IA in the table) 15 mol%, ethylene glycol 100 mol%) was used. The intrinsic viscosity of the film in this example was 0.50 dL/g. The properties of this laminate are shown in Table 3.

Comparative Example 9 A laminate was prepared in the same manner as in Example 1, except that polyethylene-2,6-naphthalenedicarboxylate with an intrinsic viscosity of 0.48 dL/g was used. The intrinsic viscosity of the film in this comparative example was 0.42 dL/g. The properties of this laminate are shown in Table 3.

Comparative Example 10 A laminate was prepared in the same manner as in Example 1, except that a copolymer polyester having an intrinsic viscosity of 0.60 dl/g (ethylene-2,6-naphthalenedicarboxylate unit 75 mol%, ethylene isophthalate unit (abbreviated as IA in the table) 25 mol%, ethylene glycol 100 mol%) was used. The intrinsic viscosity of the film of this comparative example was 0.48 dl/g. The properties of this laminate are shown in Table 3.

Example 27 In Example 1, the film thickness was increased by 3.5 times in the longitudinal direction (machine axis direction) and 4.5 times in the transverse direction (width direction).
The results are shown in Table 3.

Comparative Example 11 In Example 1, the film thickness was increased by 2.8 times in the longitudinal direction (machine axis direction) and 4.
The results are shown in Table 3.

Composition of water-soluble or water-dispersible polyester P (Tg = 68°C): Acid component 90 mol% terephthalic acid, 6 mol% isophthalic acid, 4 mol% potassium 5-sulfoisophthalate Glycol component 95 mol% ethylene glycol, 5 mol% neopentyl glycol Composition of Q (Tg = 80°C): Acid component 50 mol% 2,6-naphthalenedicarboxylic acid, 46 mol% terephthalic acid, 4 mol% sodium 5-sulfoisophthalate Glycol component 70 mol% ethylene glycol, 30 mol% ethylene oxide 2-mol adduct of bisphenol A Composition of R (Tg = 47°C): Acid component 85 mol% terephthalic acid, 15 mol% isophthalic acid Glycol component 57 mol% 1,4-butanediol 40 mol% diethylene glycol 2 mol% polyethylene glycol (molecular weight 600) Terephthalic acid 70 mol%, isophthalic acid 28 mol%, 5-sodium sulfoisophthalate 2 mol%, glycol component ethylene glycol 70 mol%, bisphenol A ethylene oxide 4 mol adduct 30 mol%. Composition of T (Tg = 90°C): Acid component 2,6-naphthalenedicarboxylic acid 81 mol%, isophthalic acid 15 mol%, 5-sodium sulfoisophthalate 4 mol%, glycol component ethylene glycol 70 mol%, bisphenol A ethylene oxide 2 mol adduct 30 mol%. Amide compound A: N,N'-ethylenebiscaprylic acid amide B: N,N'-methylenebisstearic acid amide C: N,N'-ethylenebispalmitic acid amide D: caprylic acid amide E: stearic acid amide Lubricant G: acrylic resin fine particles (average particle size 0.03 μm) H: silica (average particle size 0.12 μm) Surfactant Y: Polyoxyethylene nonylphenyl ether Z: Polyoxyethylene-polyoxypropylene copolymer

───────────────────────────────────────────────────── Continued from the front page (81) Designated States: EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), CA, CN, JP, KR, US (72) Inventor: Kenji Suzuki 3-37-19 Oyama, Sagamihara City, Kanagawa Prefecture, Teijin Limited, Sagamihara Research Center (Note) This publication is based on the internationally published gazette by the International Bureau of Patents (WIPO). Please note that the effect of the international publication of the Japanese-language patent application (Japanese-language utility model registration application) related to this publication arises pursuant to Article 184-10, Paragraph 1 of the Patent Act (Article 48-13, Paragraph 2 of the Utility Model Act), and is unrelated to this publication.

Claims (22)

[Claims] [Claim 1] A laminated film for preventing glass from shattering, comprising: (A) a biaxially oriented polyester film made of a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in at least 80 mol% of all repeating units; (B) an adhesive coating film present on at least one side of the biaxially oriented polyester film, wherein the adhesive coating film comprises a composition containing a water-soluble or water-dispersible polyester having a second-order transition temperature of 40 to 85°C and at least one amide compound selected from the group consisting of fatty acid amides and fatty acid bisamides; (C) a hard coat layer present on the adhesive coating film, provided that when adhesive coating films are present on both sides of the biaxially oriented polyester film, the hard coat layer is present only on one of the adhesive coating films; and (D) an anti-reflection layer present on the hard coat layer. 2. The laminated film of claim 1, wherein the biaxially oriented polyester film (A) has a plane orientation coefficient of 0.250 or more. 3. The biaxially oriented polyester film (A) has two orthogonal layers on the film surface.
The sum of Young's moduli in the directions is 900 kg/ ^mm2 or more and the difference is 100 kg/mm
The laminated film according to claim 1, having an area of ² m2 or less. 4. The biaxially oriented polyester film (A) has an intrinsic viscosity of 0.45 dl/
2. The laminated film according to claim 1, which comprises a copolyester having a molecular weight of at least 1000 g. 5. The laminated film of claim 1, wherein the thickness of the biaxially oriented polyester film (A) is in the range of 50 to 350 μm. 6. The laminated film of claim 1, wherein the haze of the biaxially oriented polyester film (A) is 5% or less. Claim 7: The fatty acid amide in the adhesive coating film (B) is represented by the following formula: R¹CONH₂ Here, R¹The laminate film of claim 1, wherein: is a saturated or unsaturated aliphatic group having 6 to 22 carbon atoms. Claim 8: The fatty acid bisamide in the adhesive coating film (B) is represented by the following formula: R²CONHR³NHCOR⁴ Here, R²and R⁴are each independently a saturated or unsaturated alkyl group having 6 to 22 carbon atoms.
is an aliphatic group and R³is a saturated or unsaturated aliphatic group having 1 to 15 carbon atoms;
2. The laminated film of claim 1, wherein the film is represented by the formula: 9. The laminated film of claim 1, wherein the adhesive coating film (B) contains 20 to 97% by weight of a water-soluble or water-dispersible polyester and 3 to 10% by weight of an amide compound based on the composition. 10. The laminated film of claim 1, wherein the hard coat layer is a radiation-cured layer. 11. The laminated film of claim 1, wherein the anti-reflection layer comprises a laminate in which oxide layers having a high refractive index and oxide layers having a low refractive index are alternately laminated. 12. The laminated film of claim 1, which has a haze of 5% or less. 13. A method for preventing glass from scattering when the glass is broken, comprising applying the laminated film of claim 1 to a glass surface. 14. The method according to claim 13, wherein the glass surface to which the laminated film is applied is the glass surface of an image display device. 15. An image display device comprising the laminate film of claim 1 attached to the outer surface of the glass surface of the image display device so that the anti-reflection layer of the laminate film is the outermost layer. 16. The image display device according to claim 15, which is a cathode ray tube or a plasma display. [Claim 17] A precursor laminate film for preventing glass from shattering, comprising: (A) a biaxially oriented polyester film made of a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in at least 80 mol% of all repeating units; and (B) an adhesive coating film present on at least one side of the biaxially oriented polyester film, wherein the adhesive coating film comprises a composition containing a water-soluble or water-dispersible polyester having a second-order transition temperature between 40 and 85°C and at least one amide compound selected from the group consisting of fatty acid amides and fatty acid bisamides. 18. The adhesive coating according to claim 1, wherein the coefficient of friction (μs) of said adhesive coating is 0.8 or less.
7 precursor laminate film. 19. The precursor laminate film of claim 17, wherein said adhesive coating contains a lubricant having an average particle size of 0.15 μm or less in an amount of 5 to 30% by weight based on the adhesive coating. 20. The laminated film of claim 17, wherein the surface of said adhesive coating film that is not in contact with the biaxially oriented polyester film has a centerline average surface roughness (Ra) in the range of 2 to 10 nm. [Claim 21] (A) A base film for a laminated film for preventing glass from shattering, characterized in that (a) it comprises a copolyester containing ethylene-2,6-naphthalenedicarboxylate repeating units in an amount of at least 80 mol% of all repeating units, (b) it has a plane orientation coefficient of 0.250 or more, and (c) it has an intrinsic viscosity of 0.45 dl/g or more. 22. The base film of claim 21, having a center line average surface roughness (Ra) of 10 nm or less.