JP3158554B2 - Evaporated polyester film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor-deposited polyester film, and more particularly to a vapor-deposited polyester film having excellent adhesion to a metal or metal oxide vapor-deposited film, particularly excellent water-resistant adhesion.

[0002]

2. Description of the Related Art Polyester films have better adhesion to metal-deposited films than polyolefin films, but have the disadvantage that adhesion under high humidity, especially in water, is significantly reduced. Conventional methods for improving adhesion include a method of applying a corona discharge treatment, a method of mixing a low crystalline polyester and a high crystalline polyester (Japanese Patent Publication No. 64-10188, etc.), or a urethane resin, an acrylic resin, a copolymerized polyester resin, etc. And the like have been proposed.

[0003]

[SUMMARY OF THE INVENTION] However, in the above-described prior art, the deposited film in water using any method is easily peeled off, it was free of practical value. For example, when a vapor-deposited polyester film is used for packaging, various films, such as a heat-sealing film, are laminated on the vapor-deposited surface via an easy-adhesion layer to form a bag. However, there was a disadvantage that the film was easily peeled off at the interface of.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vapor-deposited polyester film having a conventional drawback, that is, a vapor-deposited film having sufficient adhesion for practical use without easily peeling off a vapor-deposited film even in water.

[0005]

According to the present invention, as a result of intensive studies on a coating film layer provided on a polyester film as a sublayer of a vapor-deposited film, a coating film layer having the following structure is provided, whereby the coating film is formed even in water. It has been found that the adhesion of the film is excellent. That is, at least one side of the polyester film has a polyurethane resin and an epoxy
Provide a coating layer formed from a mixture containing a group-containing silane coupling agent hydrolyzate as a main component, and further provide a vapor deposition layer thereon. It is.

[0006] The polyester of the polyester film in the present invention is a generic term for polymers having an ester bond as a main bonding chain of a main chain. Particularly preferred polyesters are polyethylene terephthalate and polyethylene 2,6.
-Naphthalate, polybutylene terephthalate, polyethylene α, β-bis (2-chlorophenoxy) ethane 4,4′-dicarboxylate, etc. Polyethylene terephthalate is most preferred. Therefore, hereinafter, polyethylene terephthalate (hereinafter abbreviated as PET) will be described as a typical example of polyester. PET means that 80 mol% or more, preferably 90 mol% or more, and more preferably 95 mol% or more has ethylene terephthalate as a repeating unit. Within this limit amount range, other dicarboxylic acid components, The diol component may be copolymerized. Known additives such as heat stabilizers, oxidation-resistant stabilizers, weather-resistant stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic additives which do not impair the effects of the present invention during the PET. Fine particles, a filler, a nucleating agent, and the like.

The intrinsic viscosity of the above PET film (25
C. measured in orthochlorophenol).
20 dl / g, preferably 0.50 to 0.80 dl / g
Are suitable for the content of the present invention.

[0008] The PET film using PET is preferably biaxially oriented in a state in which the coating layers are laminated, and the biaxially oriented PET film is a non-stretched PET sheet or film in the longitudinal direction. It is made by stretching about 2.5 to 5 times each in the direction and the width direction,
It indicates a biaxially oriented pattern in wide-angle X-ray diffraction.

The thickness of the PET film is not particularly limited, and may be arbitrarily selected according to the use.

According to the present invention, a polyurethane resin and an epoxy group-containing silane are provided on a polyester film on which a vapor deposition film is provided.
It is characterized by providing a coating layer formed from a mixture containing a coupling agent hydrolyzate as a main component, wherein the main component means that the portion composed of the component in the coating layer is 60%.
% Or more, preferably 80% or more, more preferably 90% or more. The polyurethane resin is not particularly limited as long as it has a urethane bond in a main chain or a side chain, and can be arbitrarily selected from conventionally known urethane resins. In the present invention, the coating film layer may be applied on a biaxially oriented polyester film, but the point of preventing pinholes of the deposited film due to adhesion of dust and the like during the process, or forming a uniform thin coating film layer. In order to achieve the above, it is more preferable that the film is applied on a polyester film before the completion of the crystal orientation, and then dried, stretched and heat-treated to complete the crystal orientation, that is, formed in a biaxially oriented polyester film manufacturing process. When a coating film is formed by this method, it is preferable to use an aqueous resin which is advantageous in terms of the explosion-proof property of the apparatus and environmental pollution, and it is preferable to use an aqueous polyurethane for the urethane resin. The aqueous polyurethane can be arbitrarily used as long as it is produced by a conventionally known method. However, it is preferable that the polyurethane is dispersed in water without using a surfactant (self-emulsifying polyurethane). A particularly preferred example is an aqueous polyurethane resin in which a terminal isocyanate group is masked by a blocking agent. Methyl alcohol as a blocking agent,
ε-caprolactam, phenol, methyl ethyl ketoxime, malonic acid dimethyl ester, ethyl acetoacetate,
And sodium bisulfite. Among these, those stable at normal temperature and having a low dissociation temperature are preferable, and those masked with methyl ethyl ketooxom and sodium bisulfite are preferable.

Next, the epoxy group-containing silane coupling agent, which is the other component of the coating film layer , has one compound per molecule.
Silane coupling agents containing epoxy groups
And when mixed with the above polyurethane to form a coating film
It has sufficient transparency and is used after being hydrolyzed by an acid catalyst and mixed with a polyurethane resin.

Polyurethane resin (A) and containing epoxy group
The silane coupling agent hydrolyzate (B) is mixed and applied at an arbitrary ratio, but preferably (A) / (B) is in a weight ratio of 1000/1 to 1/99, more preferably 100/100.
1/10/90, more preferably 95 / 5-30 / 70
It is desirable that When the urethane resin is not contained, and when the hydrolyzate of the epoxy group-containing silane coupling agent is not contained, the adhesion to the deposited film in water is insufficient.
The thickness of the coating layer is not particularly limited, but is usually 1 μm or less.
005 μm or more, preferably 0.3 μm or less 0.03 μm
m or more, more preferably at is desirably at 0.2μm or less 0.05μm or more. If the coating thickness is too thick, the deposited film may be whitened and the gloss may be reduced. If the coating thickness is too thin, the adhesion in water may be poor. The coating layer is preferably applied during the biaxially oriented polyester film manufacturing process as described above, and when a coating film is laminated by this method, adhesion to a deposited film, It is also excellent in gloss and is particularly preferable. Further, various additives such as inorganic and organic particles, lubricants, antistatic agents, weathering agents, heat-resistant agents, dyes, pigments and the like may be added to the coating film within a range that does not impair the effects of the present invention. good.

A metal film or a metal oxide film is provided on the above-mentioned coating film layer by a known vapor deposition method, and the metal to be deposited is gold, silver, aluminum, palladium, nickel, cobalt, zinc, tin, titanium, or the like. , Indium or the like, or a mixture thereof, and an oxide thereof.

Next, the manufacturing method of the present invention will be described, but the present invention is not necessarily limited thereto.

The PET having an intrinsic viscosity of 0.63 dl / g containing so-called precipitated particles and inorganic particles (for example, silica particles having an average particle diameter of 1 μm) precipitated in the polymerization step is dried by a conventional method, melt-extruded, and extruded. The sheet-like melt is cooled and solidified on a cooling drum to produce a non-oriented PET film. This film is stretched 2.0 to 5.0 times in the longitudinal direction while being heated to 80 ° C. to 120 ° C. to be uniaxially oriented PE.
Obtain a T-film. One surface of the film is subjected to a corona discharge treatment, and a water-based mixture of an aqueous polyurethane resin and a hydrolyzate of an epoxy group-containing silane coupling agent is applied to the treated surface so as to have a predetermined thickness. The method of application is not particularly limited, and any method such as a rod coater, a gravure coater, a reverse coater, and a roll coater can be used. The coated film is guided into a tenter heated to 90 to 140 ° C. while being gripped with a clip, and is dried or dried in the width direction in a range of 2.5 to 5.0.
Stretched twice and continuously heat treated at 160 ° C to 250 ° C.
Heat treatment for 1 to 10 seconds. This may be performed 3 to 12% relaxation treatment as required during the heat treatment. A metal or metal oxide is deposited on the coating layer of the thus obtained laminated polyester film by using a vacuum deposition machine to obtain a deposited polyester film.

Such a vapor-deposited polyester film is used by laminating a film of polyethylene, polypropylene, ionomer, nylon, polyester or the like or an adhesive layer on the vapor-deposited surface.

[0017]

[Method for measuring characteristics and method for evaluating effects] The method for measuring characteristics and the method for evaluating effects in the present invention are as follows.

(1) Adhesion of deposited film Al metal is deposited using an electron beam heating type deposition machine so that the deposition thickness becomes 400 to 500 Å, and then unstretched polypropylene is formed using a polyurethane adhesive. Film (CPP) (Toray Gosei Film Co., Ltd.)
(T3501, 50 μm thick) and bonded at 40 ° C.
After leaving for 8 hours, cut into 15mm width and CPP and T
Character peeling was performed using Tensilon at a peeling rate of 10 cm / min. Peeling was evaluated by dryness (under an atmosphere of 25% and 50% RH) and water resistance (peeling by dropping water on the peeling interface).

(2) Glossiness of vapor deposition surface The glossiness of the vapor deposition surface was measured according to JIS-Z8741 (60 ° -60 °).

(3) Thickness of Coating Film A cross section of the vapor-deposited film was cut out and actually measured from a 100,000 magnification electron microscopic photograph. The thickness was defined as the average thickness in one visual field, and the average thickness at 30 measurement points was defined as the coating film thickness.

[0021]

Next, the present invention will be described with reference to examples, but is not necessarily limited thereto.

Example 1 Precipitated particles having a particle diameter of 0.5 to 1.5 μm (0.15% by weight of particles precipitated during the polymerization step, and a particle diameter of 1.0 μm
A PET pellet (intrinsic viscosity: 0.63 dl / g) containing 0.1% by weight of silica particles is sufficiently vacuum-dried and then supplied to an extruder to be melt-extruded at 280 ° C.
After filtering through a cut metal sintered filter, the mixture was extruded in a sheet form from a T-shaped die and wound around a cooling drum having a surface temperature of 30 ° C. to be cooled and solidified. In order to improve the adhesion between the sheet and the surface of the cooling drum during this time, a wire electrode was arranged on the sheet side and a DC voltage of 6000 V was applied. The unstretched PET film thus obtained was heated to 95 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. One surface of this film was subjected to a corona discharge treatment in air, and the following formulated paint was applied to the discharge treatment surface side with a rod coater. The coating thickness is set to be 0.
The thickness was set to 1 μm.

[0023]

[Formulation coating composition] ・ Aqueous dispersion type polyurethane resin (Elastron H38 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)) having a terminal isocyanate group masked: 90 parts by weight ・ γ-glycidoxypropyl trimethoxysilane Hydrolyzed in an acidic aqueous solution of PH3 to 5 by the method
... 10 parts by weight The coating liquid mixed at the above solid content ratio is diluted with water to 3% by weight.
Was prepared.

The coated uniaxially stretched PET film is gripped with a clip and guided into a tenter heated to 110 ° C. to dry the water. Then, the film is continuously stretched in the width direction at a zone heated to 120 ° C. The film was stretched 3.5 times, and further subjected to a heat treatment at 225 ° C. for 5 seconds to obtain a laminated polyester film having a film thickness of 12 μm and a coating layer thickness of 0.1 μm. Al metal was deposited on the coating layer side of this film using an electron beam heating type vacuum vapor deposition machine to a thickness of 400 to 500 angstroms to obtain a vapor-deposited polyester film.
As shown in Table 1, this vapor-deposited polyester film was extremely excellent in gloss, and had good dry adhesion and water-resistant adhesion.

Examples 2 to 5 and Comparative Examples 1 and 2 The polyurethane resin and the epoxy group-containing silane
A vapor-deposited polyester film was prepared in the same manner except that the mixing ratio of the hydrolyzate of the coupling agent was changed. The deposited films provided on the coating film formed from the composition in which the two components were mixed were all excellent in adhesion, but the deposited film provided on the coating film formed with only one of the two components Had remarkably poor water adhesion.

Comparative Examples 3 and 4 A biaxially oriented PET film and a vapor-deposited polyester film produced by vapor-depositing Al metal on a biaxially oriented PET film subjected to a corona discharge treatment in air have water-resistant adhesion as shown in Table 1. It was easily peeled off from the PET / Al interface without any.

Comparative Examples 5 and 6 [0027] γ- (2-aminoethyl) aminopropyltrimethoxysilane was used instead of the epoxy compound of Example 1 (Comparative Example 5), or water dispersibility was used instead of the urethane resin of Example 1. Except for using acrylic resin (Comparative Example 6), vapor-deposited polyester films were prepared in the same manner, but all of them had remarkably improved water-resistant adhesion.

[0028]

[Table 1]

[0029]

According to the present invention, in providing a metal film and a metal oxide vapor-deposited film on a polyester film, a coating layer formed mainly of a mixture of a polyurethane resin and an epoxy group-containing compound is provided as an undercoat layer. It has been found that the water resistance of the deposited film is dramatically improved.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08L 63/00 C08L 63/00 C23C 14/02 C23C 14/02 A // C08L 63:00 (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 14/00-14/58 B32B 9/00 B32B 15/08 104 B32B 27/36 C08J 7/04 CFD C08L 63/00

Claims (5)

(57) [Claims] 1. A polyurethane film and an epoxy group-containing silane coupling agent on at least one surface of a polyester film.
An evaporated polyester film comprising: a coating layer formed from a mixture containing a hydrolyzate of a coating agent as a main component; and a vapor deposition layer further provided thereon. 2. The vapor-deposited polyester film according to claim 1, wherein the polyurethane resin is an aqueous polyurethane resin. 3. The composition according to claim 1, wherein the polyurethane resin is a composition containing a blocked isocyanate group.
3. The vapor-deposited polyester film according to 1 or 2 . 4. The mixing weight ratio (A) / (B) of the polyurethane resin (A) and the epoxy group-containing compound (B) is 100.
0 / 1-1 / 99 according to claim 1 to 3, characterized in that
The evaporated polyester film according to any one of the above. 5. The coating layer is applied to the polyester film before completing crystalline orientation, applying, stretching after drying at least one direction, more of claims 1-4, characterized in that a layer subjected to heat treatment A vapor-deposited polyester film as described in Crab.