JP2605816B2 - Evaporated polyester film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a vapor-deposited polyester film used for packaging materials, decorative materials, various protective coatings, etc. The invention relates to a vapor-deposited polyester film which is extremely excellent even in the presence of.

(Prior art) Polyester films on which metals and metal oxides are deposited, especially metal-deposited polyethylene terephthalate films, are excellent in gas barrier properties, water impermeability, visible / ultraviolet light shielding properties, heat ray reflection properties, etc. It is used for applications. For example, it is used as a packaging material for food and industrial parts, a decoration material, a window glass shielding material, a gold / silver thread material, and various protective coating materials. However, the adhesiveness (adhesion) between the substrate layer and the vapor-deposited layer of the above-mentioned vapor-deposited film, particularly when water is present, is not always sufficient. For example, when food is packaged with a heat-sealable film in which a heat-sealable layer made of a polyolefin-based resin is laminated on the surface of a metal-deposited polyester-based base film, if boiling treatment is performed for sterilization, Has the disadvantage that it is easily peeled off.

As a method for improving the adhesion between the polyester base film and the metal deposition layer, for example, Japanese Patent Publication No. 55-232 and Japanese Patent Application Laid-Open No. 56-16549 disclose other copolymer compositions besides polyester. For preparing a base film by mixing the same. JP-A-57-87357 discloses a method of physically changing the surface state of a base film, and JP-B-59-51424 discloses a method of forming a specific resin composition on the surface of a base film. A method of forming a layer of the resin composition by applying a solution is disclosed. However, even if these methods are adopted, the adhesion between the base film or the laminated film and the metallized layer is still not sufficient, especially in the presence of water (particularly hot water). Is insufficient. Further, of the above methods, in the method of applying a resin composition solution described in JP-B-59-51424, flammability and toxicity are concerned because an organic solvent is used, and there is a risk of work. . It is not preferable in terms of pollution generation and energy saving.

As a method for improving the adhesion between the base film and the coating layer formed on the surface thereof in the presence of water, for example,
JP-B-55-45835 and JP-B-55-12870 disclose methods for improving the adhesion between a substrate film and a printed layer. According to this method, a polyester having a specific composition is blended into the base film. However, this method has a relatively good effect when the layer laminated on the base film is a printed layer, but when the layer laminated is a metal-deposited layer, it can be used in the presence of water. In particular, the adhesiveness in the presence of hot water is still not sufficient.

JP-A-48-37480 discloses specific polyester-based resin and polyether-based resin compositions, for example, as an undercoating agent for improving the adhesion between a polyester substrate and a layer laminated thereon. These resin compositions have good adhesiveness to polyester as a base material, but often have insufficient adhesiveness to a metal deposition layer to be laminated. Further, when the above resin composition is applied to a substrate, an organic solvent is used.
As in the case of JP 59-51424, there is a work hazard due to flammability and toxicity.

As a method of forming an undercoat layer on a base film without using an organic solvent, Japanese Patent Publication No. 54-16557 discloses a method of applying an aqueous solution containing a composition in which components are changed to water-soluble. Have been. However, for example, the resulting vapor-deposited film has the disadvantage of poor water resistance because the composition used is essentially water-soluble. Also in the production process, the aqueous solvent has a disadvantage that the wettability of the hydrophobic substrate film is poor, and it is difficult to obtain a uniform coating film.

Thus, the adhesiveness between the inorganic vapor-deposited layer of a metal or the like and the polyester-based substrate film, particularly in the presence of water, is good, and for example, the obtained product can be boiled. At present, a vapor-deposited polyester film has not been obtained.

(Problems to be Solved by the Invention) The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to achieve excellent interlayer adhesion with a metal deposition layer, particularly excellent adhesion in the presence of water. It is to provide a vapor-deposited polyester film.

(Means and Actions for Solving the Problems) The vapor-deposited polyester film of the present invention comprises a base film made of a polyester-based resin and a coating layer formed on at least one surface of the base film. Wherein the coating layer is formed of a substantially water-insoluble and water-dispersible composition comprising a polyester (a) and a polyurethane (b) as main components; Water-insoluble and water-dispersible polyester (a) containing dicarboxylic acids having a sulfonic acid metal base in a proportion of 0.5 to 5 mol% and aromatic dicarboxylic acids in a proportion of 50 mol% or more. , And glycols; the glass transition temperature of the polyester is 100 ° C. or less; the substantially water-insoluble and water-dispersible Polyurethane (b) is obtained from a polyester polyol and a diisocyanate component; and, the polyester (a) and polyurethane (b) 95 is in the composition: 5 to 10: are contained in a weight ratio of 90.

As the base film used for the vapor-deposited polyester film of the present invention, a film of a thermoplastic polyester resin, for example, a film of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or the like is suitable. In particular, a copolymerized polyester film in which at least 80% of the components correspond to polyethylene terephthalate (that is, the terephthalic acid component and the ethylene glycol component are at least 80% of all components), or a polyester containing polyethylene terephthalate at a ratio of at least 80% Blend films are preferably used. The polyester component other than the polyethylene terephthalate component in such a copolymerized polyester film or polyester blend film may be any polyester component. As the dicarboxylic acid component constituting such a polyester, any of aromatic, aliphatic and alicyclic dicarboxylic acids can be used. Examples of aromatic dicarboxylic acids include isophthalic acid, orthophthalic acid, and 2,6-naphthalenedicarboxylic acid, and examples of aliphatic dicarboxylic acids include succinic acid, adipic acid, sebacic acid, and oxalic acid, and alicyclic dicarboxylic acids. Examples of the acid include 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. As the aromatic dicarboxylic acid, a part of an oxyacid such as p-hydroxybenzoic acid is preferably used. Examples of the glycol component constituting the polyester include aliphatic glycols having 2 to 8 carbon atoms or 6 glycols.
~ 12 alicyclic glycols are preferred. Such glycols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol,
1,2-cyclohexane dimethanol, 1,3-cyclohexane dimethanol, 1,4-cyclohexane dimethanol, p-
Examples include xylene glycol, diethylene glycol, and triethylene glycol. In addition, it is also possible to use polyether glycol as the aliphatic glycol, and examples thereof include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

These acid components and dicarboxylic acid components are polymerized (or copolymerized) by an ordinary method to prepare a polyester. This polyester is appropriately mixed as required, and usually a film (base film) is obtained by melting and extrusion or by dissolving in a solvent and casting. The base film used is uniaxially or biaxially stretched as required.

Among the resins contained in the composition used for the coating layer formed on the base film surface, the polyester (a) is substantially water-insoluble and water-dispersible, and the dicarboxylic acid constituting the polyester The components are
As described above, 0.5 to 5 mol% is a dicarboxylic acid having a sulfonic acid metal salt (having a metal sulfonate) group, and 50 mol% or more is an aromatic dicarboxylic acid.
Here, "substantially water-insoluble" means that the polymer to be tested does not dissipate in the hot water even when immersed and stirred in hot water at 80 ° C. More specifically, when the polymer to be tested is made into a chip and placed in a large excess of hot water (80 ° C.) and stirred for 24 hours, the weight of the polymer decreases by 5% by weight. It means the following. Examples of the dicarboxylic acid containing a sulfonic acid metal base contained in such a polyester include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5 [4-sulfophthalic acid. Phenoxy] metal salts such as isophthalic acid. Particularly, 5-sodium sulfoisophthalic acid and sodium sulfoterephthalic acid are preferred. If the amount of the dicarboxylic acid is less than 0.5 mol%, the dispersibility of the resulting polyester-containing composition in water is impaired, and as a result, it becomes difficult to form a uniform coating film, and the resulting coating film Adhesion between the metal and the metal deposition layer is reduced. Conversely, if it exceeds 5 mol%, the adhesive performance with the metal deposition layer in the presence of water will be reduced. In general, the amount of the sulfonic acid metal base-containing dicarboxylic acid is preferably small in a range that does not impair the dispersibility in water of the composition containing the obtained polyester (which varies depending on the components, the dispersion method, and the like).

As the dicarboxylic acid other than the above-mentioned dicarboxylic acid having a sulfonic acid metal base, any of aromatic, aliphatic and alicyclic dicarboxylic acids can be used, but the aromatic dicarboxylic acid contains 50 mol% or more, preferably 70 mol% or more. It is contained in a proportion of at least mol%. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, and 2,6-naphthalenedicarboxylic acid. If the amount of the aromatic dicarboxylic acid is too small, the film formed by the composition containing the obtained polyester has poor mechanical strength and poor adhesion in the presence of water (particularly in the presence of hot water).

Examples of aliphatic dicarboxylic acids include succinic acid, adipic acid, and sebacic acid, and examples of alicyclic dicarboxylic acids include:
1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4
-Cyclohexanedicarboxylic acid and the like. Among these non-aromatic dicarboxylic acid components, aliphatic dicarboxylic acids are effective for improving the water dispersibility of the composition containing the obtained polyester and the adhesion of the coated film obtained by applying the polyester. However, if the amount is excessive, the mechanical strength and the adhesiveness in the presence of hot water of the coating formed by the composition containing the polyester are reduced. The alicyclic dicarboxylic acid may enhance the adhesive performance of the obtained coated film in the presence of water, but if it is excessive, it reduces the water dispersibility of the obtained polyester.

As the glycol component contained in the polyester used for the coating layer, an aliphatic glycol having 2 to 8 carbon atoms or an alicyclic glycol having 6 to 12 carbon atoms is used. Such glycols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4
-Butanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-
Cyclohexane dimethanol, 1,4-cyclohexane dimethanol, p-xylylene glycol, diethylene glycol, triethylene glycol, and the like. Bisphenol-based compounds having more than 12 carbon atoms can also be suitably used.

A polyester is prepared by a melt polycondensation method using the above dicarboxylic acid component and polyhydric alcohol component. For example, a direct esterification method in which each of the above components is directly reacted to distill off water to esterify and perform polycondensation; or a dialkyl ester of the above dicarboxylic acid component is reacted with a glycol component to distill an alcohol to form an ester. It is prepared by a transesterification method in which a polycondensation is carried out while exchanging. In addition to the melt polymerization method, a solution polycondensation method, an interfacial polycondensation method, or the like may be employed.

The water-insoluble and water-dispersible polyester thus obtained must have a glass transition temperature (Tg) of 100 ° C or less. The glass transition temperature is preferably
The temperature is 80 ° C or lower, more preferably 20 to 80 ° C. If the glass transition temperature exceeds 100 ° C, the film forming property when applying the composition containing the polyester to the base film is poor.
The adhesion between the obtained coating layer and the substrate film becomes insufficient, and as a result, the adhesion between the obtained coating film and the deposited layer laminated thereon is also poor. The lower limit of the glass transition temperature is not particularly limited, but is preferably 20 ° C. or more in consideration of the blocking property and the hot water resistance of the obtained coated film.

Among the resins contained in the composition used for the coating layer, the polyurethane (b) is also substantially water-insoluble and water-dispersible. The term "substantially water-insoluble" has the same meaning as in the case of the polyester (a). Examples of the polyurethane (b) include a polyurethane obtained from a polyester polyol and a diisocyanate; or a low-molecular compound having two or more active hydrogens such as a diol or a diamine acting on the polyurethane as a prepolymer. The polyurethane obtained by this is used.

The polyester polyol is obtained by reacting a dicarboxylic acid with a glycol. These dicarboxylic acids and glycols include the above-mentioned polyester (a)
The same compounds as the dicarboxylic acids and glycols that can constitute the above can be used. Of the dicarboxylic acid components, terephthalic acid and isophthalic acid are preferably used as aromatic dicarboxylic acids, and adipic acid and sebacic acid are preferably used as aliphatic dicarboxylic acids. As the glycol component, alkylene glycols having 4 or more carbon atoms (for example,
Butanediol, hexanediol) and an alicyclic glycol (for example, cyclohexanedimethanol) or a bisphenol compound are preferably used in combination.
The polyester polyol can be prepared by polycondensing the above dicarboxylic acid and glycol by the same method as the polyester of (a).

As the diisocyanates to be reacted with the polyester polyol thus obtained, any of aromatic, aliphatic and alicyclic diisocyanates can be used. For example, aromatic diisocyanates such as toluene diisocyanate are preferred. A coating film formed by a composition containing a polyurethane obtained using such an aromatic diisocyanate has high strength and excellent adhesion to a deposited layer of the obtained coating film in the presence of water.

The polyurethane (b) is obtained by reacting the above-mentioned polyester polyol with the above-mentioned diisocyanate in a usual manner. Furthermore, it is also possible to react with a low molecular compound having two or more active hydrogens such as diols and diamines to extend the chain. As the diol, 1,6-hexanediol and the like can be used, and as the diamine, hexamethylene diamine and the like can be used.

The above polyester (a) and polyurethane (b)
Is contained in the composition forming the coating layer in a weight ratio of 95: 5 to 10:90, preferably 90:10 to 50:50. If the amount of the polyester (a) is excessive, the adhesion between the obtained coating film and the vapor-deposited layer in the presence of water is poor. If the amount of the polyurethane (b) is excessive, the adhesion of the coating layer to the substrate and the formation of the film are formed. Poor sex.

To the composition for forming the coating layer, a resin component having a crosslinking property may be added in addition to the water-insoluble polyester (a) and the polyurethane (b). Examples thereof include melamine-based, epoxy-based, azirine-based, and urethane-based resins. By containing these, the effect of preventing blocking of the coating layer obtained and improving the solvent resistance can be obtained. However, there are drawbacks in that the stability of the aqueous dispersion of the composition containing these is reduced, and it is difficult to melt and reuse the resulting coated film.
Therefore, the addition of the crosslinking component is appropriately performed according to the purpose.

The composition may further contain other additives. Examples thereof include inorganic inert particles such as silica, calcium carbonate, kaolinite, alumina, talc, and barium sulfate; and organic inert particles such as benzoguanamine-based resin and polystyrene-based resin (all having a particle size of about 0.01 to 10 μm). By adding these, the slipperiness and the blocking resistance can be improved. Further, if necessary, a pigment; an organic or inorganic antistatic agent; a preservative; an antifoaming agent: an ultraviolet absorber may be used. The type and amount of additives
There is no particular limitation as long as the resulting film does not significantly impair the interlayer adhesion to the deposited layer in the presence of water.

The composition to be coated on the base film is made into an aqueous dispersion by various methods. For example, for the water-insoluble polyester (a), a method in which the polyester fine particles are added to hot water and dispersed under strong stirring; a method in which the water-insoluble polyester is dispersed in water together with a water-soluble organic compound can be adopted. . Among these, a method using a water-soluble organic compound (usually, an organic solvent) is particularly preferable. The organic compounds used usually have a boiling point of 6
A compound having a temperature of 0 to 200 ° C. and a solubility of 20 g or more per water at 20 ° C. is used. These include aliphatic and cycloaliphatic alcohols, ethers, esters, and ketones. Alcohols include methanol, ethanol,
There are monohydric alcohols such as isopropanol and n-butanol; glycols such as ethylene glycol and propylene glycol; and glycol derivatives such as methyl cellosolve, ethyl cellosolve and n-butyl cellosolve. Examples of ethers include dioxane and tetrahydrofuran; and examples of esters include ethyl acetate;
Ketones include methyl ethyl ketone. Two or more of these water-soluble organic compounds can be used in combination. Of the above compounds, butyl cellosolve and ethyl cellosolve can be suitably used from the viewpoint of dispersibility in water and coating performance on a film.

To prepare an aqueous dispersion of polyester (a) using such a water-soluble organic compound, the above-mentioned polyester chip and the above-mentioned water-soluble organic compound are mixed at 50 to 200 ° C., water is added thereto, and the mixture is stirred. Method for dispersing;
A method in which a mixture obtained by mixing at ~ 200 ° C is added to water and stirred and dispersed; or a method of stirring and dispersing the above polyester, water-soluble organic compound and water at 40 to 120 ° C is adopted. You. It is possible to use an emulsifier for dispersion, but in this case the water resistance of the resulting coating film is slightly reduced.

For the polyurethane (b), a method in which the polyurethane fine particles and an emulsifier are added to water and dispersed under vigorous stirring; when synthesizing the polyurethane, a polyurethane having an isocyanate group at a terminal (prepolymer), a chain extender A method in which emulsifiers and emulsifiers are reacted with strong stirring in water to simultaneously disperse and polymerize by mechanical shearing force; introducing ionic groups such as hydroxyl groups, amino groups, and carboxy groups into the side chains or terminals of polyurethane. Thus, a method of imparting self-emulsifiability and dispersing is used. Considering the water resistance of the resulting film, a method using no emulsifier is preferred.

The above-mentioned dispersions of the polyester (a) and the polyurethane (b) are mixed, and if necessary, various additives are added. In the above-mentioned dispersion step, these additives are appropriately added to form a uniform aqueous dispersion. Prepared.

The aqueous dispersion is applied on the base film by a known method. For example, the above-mentioned dispersion is applied on an unstretched base film obtained by melting and extrusion, or on a base film obtained by uniaxially or biaxially stretching the unstretched film. Heat treatment is performed. A biaxially oriented film obtained by applying a dispersion onto an unstretched or uniaxially stretched base film, further stretching the film uniaxially or biaxially, and heat-treating the film to improve the adhesiveness of the coating layer, economic efficiency, etc. It is preferable from the point. In particular, from the viewpoint of workability, apply the dispersion onto a uniaxially stretched base film,
Next, a method of obtaining a biaxially stretched film by stretching in an orthogonal direction is preferable. Any of known methods such as a roll coating method (gravure method, reverse method, etc.), a knife coating method, a rod coating method, a nozzle coating method, and an air knife coating method can be used for applying the aqueous dispersion. The amount of coating is determined according to the purpose. Usually, the amount of the composition present on a unit area (m ² ) of the finally obtained coated film obtained by performing biaxial stretching is 0.005 to 5 g, preferably 0.01 to 5 g. ~ 1g. Coating amount is 0.0
05G / m ² without initial effect is obtained when falls below, blocking is likely to occur coated film obtained exceeds a 5 g / m ^2. When applying the aqueous dispersion of the composition, if necessary,
The surface of the base film may be subjected to a corona treatment, or a physical or chemical surface treatment.

An inorganic substance is deposited on the surface of the coated polyester film thus obtained. As the inorganic substance to be deposited, metals, metal oxides, inorganic oxides other than metals, and the like are used. The above metals include gold, silver, aluminum,
Zinc, tin, copper, nickel, iron, cobalt, chromium, manganese, palladium, titanium, indium and the like are used. Particularly, aluminum is widely used. A silicon oxide compound or the like is used as the inorganic oxide. These are used alone or in combination of two or more. These inorganic substances are deposited on the surface of the coating film of the above-mentioned coating film by a usual method. A vacuum deposition method or the like is preferably used. The thus obtained evaporated polyester film is used for various purposes. In particular, a sheet or film made of various resin materials is laminated on a vapor-deposited layer obtained by vapor-depositing a metal or a metal oxide on a coating layer, and can be suitably used as a food packaging material. Such a laminate does not peel even when immersed in hot water. As the resin material constituting the sheet or film to be laminated, polyethylene, polypropylene, various ionomers, ethylene-vinyl acetate copolymer, polyvinylidene chloride copolymer, polyester, polyamide and the like are used. As described above, in the vapor-deposited polyester film of the present invention, a resin composition having a specific composition is laminated on a base film, and a vapor-deposited layer is formed on the coating layer. Therefore, the interlayer adhesion between the base material and the coating and the interlayer adhesion between the coating layer and the deposition layer are excellent. Particularly, the adhesiveness in the presence of water is extremely excellent. Therefore, the evaporated polyester film of the present invention
It is particularly suitably used as a food packaging film to be subjected to hot water sterilization and the like.

(Examples) Hereinafter, the present invention will be described with reference to examples.

Example 1 (A) Preparation of polymer and aqueous dispersion: First, polyester (a) was prepared by the following method. 49 mol% of dimethyl terephthalate (total dicarboxylic acid component), 49 mol% of dimethyl isophthalate and 2 mol% of sodium 5-sulfoisophthalate as dicarboxylic acid component; and 50 mol% of ethylene glycol as glycol component
(Of the total glycol component) and neopentyl glycol (50 mol%), a transesterification reaction and a polycondensation reaction were carried out in a conventional manner. This results in a glass transition point of 69 ° C
Was obtained. Polyester 300 obtained
By weight, 150 parts by weight of n-butyl cellosolve was heated and stirred to obtain a viscous liquid. 550 parts by weight of water was gradually added thereto with stirring to obtain a uniform pale white aqueous dispersion having a solid content of 30%.

Next, polyurethane (b) was prepared by the following method. Polyester (polyester polyol) using adipic acid as a dicarboxylic acid component; and 80 mol% of 1,4-butanediol (of a glycol component) as a glycol component and 20 mol% of a propylene oxide (1 mol) adduct of bisphenol A. I got A urethane polymer was obtained by allowing toluene diisocyanate to act on this polyester. Using this as a prepolymer, the chain was extended by the action of 1,6-hexanediol, and the aminocarboxylate was reacted at the end to obtain a water-insoluble and water-dispersible polyurethane (b). This was dispersed in hot water with stirring to obtain a 25% aqueous dispersion.

The aqueous dispersion of the polyester (a) and the aqueous dispersion of the polyurethane (b) are added to a mixture of equivalent amounts of ion-exchanged water and isopropyl alcohol so that the solid content of each is 4% and 1%, A uniform dispersion having a total resin solid content of 5% was obtained.

(B) Preparation of vapor-deposited film: Polyethylene terephthalate was melt-extruded at 280 to 300 ° C and cooled with a cooling roll at 15 ° C to obtain an unstretched film having a thickness of about 150 µm. This unstretched film was stretched 3.5 times in the longitudinal direction between a pair of rolls at 85 ° C. with different peripheral speeds. Next, the aqueous dispersion containing the polyester (a) and the polyurethane (b) obtained in the section (A) is applied by a roll coater method, dried with hot air at 70 ° C., and then tentered at 98 ° C. in a transverse direction at 3.5 ° C. The film was double-stretched and heat-set at 200 to 210 ° C. to obtain a biaxially stretched coated polyester film having a thickness of 12 μm. The final coating amount of the coating agent (coating composition) was about 0.04 g / m ² . Table 1 shows properties, blending ratios, and the like of the resin forming the coating layer of the obtained coating film. Aluminum was deposited to a thickness of 600 mm on the surface of the coating layer of the coating film.

(C) Performance evaluation of the vapor-deposited film: An unstretched polypropylene (PP) sheet having a thickness of 60 μm is laminated on the vapor-deposited layer surface of the vapor-deposited film obtained in the section (B) by a usual dry lamination method, and then subjected to an aging treatment. Was. The obtained laminate was cut into a strip having a width of 15 mm and immersed in boiling water of 95 ° C. or higher for 30 minutes (boil treatment). 120 with another sample
An experiment (retort treatment) of immersing in high-pressure water at 30 ° C. for 30 minutes was also performed.

Partially peel off the PP film and the base film at the end of the untreated, boiled and retorted laminates,
The exfoliated ends were fixed to Tensilon chucks manufactured by Toyo Baldwin Co., Ltd., and pulled in the longitudinal direction at a speed of 200 mm / min to perform T-shaped exfoliation. Separately, a peeling experiment was performed under the same conditions while a water droplet was applied to the peeling interface. Table 2 shows the interlayer adhesion (g / 15 mm).

Example 2 Example 1 was the same as Example 1, except that cyclohexane dimethanol was used instead of neopentyl glycol to obtain a polyester (a) having a glass transition temperature of 82 ° C. Table 1 shows properties, mixing ratios, and the like of the resin forming the base material coating layer of the obtained deposited film. Table 2 shows the performance evaluation of the deposited film. Examples 3 to 5 and Comparative Examples 1 to be described later.
Table 1 and Table 2 also show the results of No. 8.

Example 3 The same as Example 1 except that isophorone diisocyanate was used instead of toluene diisocyanate.

Example 4 Polyester polyol was obtained using terephthalic acid (50 mol%) and isophthalic acid (50 mol%) as dicarboxylic acid components and ethylene glycol (60 mol%) and diethylene glycol (40 mol%) as glycol components. This example is the same as Example 1 except that hexamethylene diisocyanate was allowed to act as a diisocyanate component to prepare a urethane polymer (prepolymer).

Example 5 The same as Example 1 except that the mixing ratio of the polyester (a) and the polyurethane (b) was 20:80 (weight ratio).

Comparative Example 1 As a dicarboxylic acid component constituting the polyester (a), 23 mol% of dimethyl terephthalate, 22 mol% of dimethyl isophthalate, 53 mol% of adipic acid, and 2 mol% of sodium 5-sulfoisophthalate were used. The same as Example 1 except that a polyester having a temperature of 5 ° C. was obtained.

Comparative Example 2 The same as Example 1 except that 45 mol% of dimethyl terephthalate, 45 mol% of dimethyl isophthalate, and 10 mol% of sodium 5-sulfoisophthalate were used as the dicarboxylic acid components constituting the polyester (a). is there.

Comparative Example 3 50 mol% of dimethyl terephthalate, 40 mol% of dimethyl isophthalate and 10 mol% of sodium 5-sulfoisophthalate as dicarboxylic acid components constituting polyester (a); and 50 mol% of ethylene glycol as a glycol component Example 1 except that and 50 mol% of polyethylene glycol (molecular weight 4000) were used.
Is the same as

Comparative Example 4 70 mol% of dimethyl terephthalate, 25 mol% of dimethyl isophthalate and 5 mol% of sodium 5-sulfoisophthalate as dicarboxylic acid components constituting polyester (a); and 30 mol% of ethylene glycol as a glycol component Glass transition temperature using bisphenol A and ethylene oxide adduct of bisphenol A 70 mol%
The same as Example 1 except that a polyester of 103 ° C. was obtained.

Comparative Example 5 The same as Example 1 except that the mixing ratio of the polyester (a) and the polyurethane (b) was 96: 4 (weight ratio).

Comparative Example 6 The procedure of Example 1 was repeated except that poly (oxytetramethylene) glycol was used in place of the polyester polyol, and toluene diisocyanate was allowed to act on the poly (oxytetramethylene) glycol to prepare a polyether-type polyurethane.

Comparative Example 7 The same as Example 4 except that an aqueous dispersion containing only polyurethane (b) at a solid content of 5% was used.

Comparative Example 8 The same as Example 1 except that the aqueous dispersion containing the polyester (a) and the polyurethane (b) was not applied.

From Tables 1 and 2, it can be seen that the vapor-deposited polyester film of the present invention shows excellent adhesion between the base film and the vapor-deposited layer even in the presence of hot water. On the other hand, the film of Comparative Example 8 in which the coating layer made of the composition containing the polyester (a) and the polyurethane (b) is not formed cannot obtain such an effect. When the composition contains only polyurethane (b), a uniform coating layer cannot be obtained,
Therefore, the adhesiveness with the vapor deposition layer is not sufficient, and the vapor deposition surface is not uniform. If the composition of the polyester (a) or the polyurethane (b) in the composition forming the coating layer is outside the scope of the claims, a sufficient adhesive effect between the substrate and the vapor-deposited layer, especially in the presence of hot water, No good adhesive effect is obtained (Comparative Examples 1-3 and 5). Even when the Tg of the polyester (a) is high as in Comparative Example 4 and when the polyurethane (b) is prepared using polyether polyol instead of polyester polyol as in Comparative Example 6, sufficient adhesion of the vapor-deposited layer is obtained. No effect.

(Effect of the Invention) According to the present invention, as described above, there is provided the
A vapor-deposited polyester film having excellent adhesion between the layer and the base film is obtained. The adhesion between the deposited layer and the substrate film is sufficient even in the presence of water, especially hot water. Such a vapor-deposited film is used for applications such as food packaging films, decorative materials, and various protective films, and is particularly suitably used for food packaging films that are subjected to heat treatment with hot water.

Claims (2)

(57) [Claims] 1. A vapor-deposited polyester film having an inorganic vapor-deposited layer provided on the surface of a coated polyester film having a coated layer formed on at least one surface of a base film made of a polyester-based resin. Is formed by a composition comprising a substantially water-insoluble and water-dispersible polyester (a) and a polyurethane (b) as a main component, and the substantially water-insoluble and water-dispersible polyester (a) is A dicarboxylic acid containing 0.5 to 5 mol% of a dicarboxylic acid having a sulfonic acid metal base and an aromatic dicarboxylic acid in a proportion of 50 mol% or more; and glycols. 100 ° C. or lower, and the substantially water-insoluble and water-dispersible polyurethane (b) is a polyester polyol and a diisocyanate. Obtained from sulfonate component, and the polyester (a) and polyurethane (b) 95 is in the composition: 5 to 10: are contained in a weight ratio of 90, deposited polyester film. 2. The film of claim 1, wherein said coated polyester film is oriented in at least one direction.