JP2000355341A - Lid material - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Even after filling the contents and heat-sealing the opening with a lid material, it is possible to perform metal inspection and the like, and it is possible to completely burn or regenerate after use. Provide a lid material. SOLUTION: The opacity (JIS P-8138) is 8
Gas barrier properties in which a heat-sealable resin adhesive layer (IV) is laminated on one surface of a microporous resin stretched film base layer (0% or more) and an inorganic oxide thin film layer (III) is provided on the other surface. A laminate having a layer structure formed by laminating a resin film layer (II), wherein the laminate has a moisture permeability (JIS-Z
-20208) is 5 g / m ² · 24 hr or less, and the oxygen permeability (JIS-Z-1707) is 5 cc / m ² · 24 hr.
-A lid material characterized by being atm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas barrier lid material useful as a lid material for food containers such as miso, milk pudding, yogurt, cheese, cheesecake, fresh milk and bavarois.

[0002]

2. Description of the Related Art Lids for food containers such as miso, milk pudding, yogurt, cheese, cheesecake, raw milk, bavarois and the like usually have a function of preventing transmission of odor, water vapor, oxygen and visible light. It has been demanded. In order to meet this requirement, generally, (1) a laminate in which each layer of an aluminum vapor-deposited biaxially stretched polyethylene terephthalate film / a polyethylene film adhesive layer / a polyethylene heat sealable film is provided on the back surface of a wax-coated printing paper. (2) Laminated aluminum foil on the back of wax-coated printing paper and a heat-sealing resin layer such as ethylene-acrylic acid copolymer or ethylene-vinyl acetate copolymer on the back. An opaque lid made of a material is used for molding these food containers.

[0003] In general, the food container is filled with contents such as miso, milk pudding, and yogurt, inspected for foreign substances such as metal powder in the contents, and then opened. The lid is heat-sealed on the mouth and shipped or stored. However, inspection during opening provides an opportunity for dust and foreign matter to enter the container.Therefore, it is necessary to provide a lid material capable of inspecting for metal powder contamination after filling and heat sealing the opening. Desired by the market. Also,
The conventional lid material has a drawback that after burning, the aluminum foil is burned and remains as scraps, and the treatment requires time and effort.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve these problems of the prior art. That is, the present invention provides a lid material capable of performing metal inspection or the like even after filling the contents and heat-sealing the opening with the lid material and capable of completely burning or regenerating after use. Is to be solved.

[0005]

As a result of intensive studies to solve these problems, the present inventors have found that the intended purpose can be effectively achieved by using a lid material having a specific structure and physical properties. Having found what can be achieved, the present invention has been provided. That is, in the first invention of the present invention, a heat-sealing resin adhesive layer (IV) is laminated on one surface of a microporous resin stretched film base layer (I) having an opacity (JIS P-8138) of 80% or more. A laminate having a layer structure in which a gas barrier resin film layer (II) having an inorganic oxide thin film layer (III) provided on the other surface is laminated, wherein the laminate has a moisture permeability (JIS Z- 0208) is 5g
/ M ² · 24 hr or less, oxygen permeability (JIS Z-1
707) is 5 cc / m ² · 24 hr · atm or less.

The second invention of the present invention relates to an opacity (JIS
A gas barrier resin film layer (II) provided with an inorganic oxide thin film layer (III) on a microporous resin stretched film base layer (P-8138) of 80% or more, and further thereon A laminate having a layer structure obtained by laminating a heat-sealing resin adhesive layer (IV), wherein the laminate has a moisture permeability (JIS Z-0208) of 5 g / m ² · 24 hr.
Below, the oxygen permeability (JIS Z-1707) is 5cc
/ M ² · 24 hr · atm or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a structure, a material and an embodiment of a cover material of the present invention will be described in detail. <Structure of lid material> The structure of the lid material is a gas barrier resin provided with a printing (P) / microporous resin stretched film base layer (I) having an opacity of 80% or more / an inorganic oxide thin film layer (III). Film layer (II) / Heat-sealable resin adhesive layer (I
V), specifically, a laminate as shown in the enlarged cross-sectional view of the lid member in FIG. The laminate has a moisture permeability (JIS Z-0208) of 5 g / m ² · 24 hr.
Below, and oxygen permeability (JIS Z-1707) is 5c
It shows physical properties of c / m ² · 24 hr · atm or less. In FIG. 1, I is a stretched microporous resin film, II is a gas barrier resin film layer, III is an inorganic oxide thin film layer, IV is a heat sealing resin layer, and P is printing.

<Layer Structure of Laminate> (1) Base Layer of Stretched Microporous Resin Film (I) The stretched microporous resin film (I) imparts rigidity to the cover material and is made opaque by printing. It has the function of facilitating identification and reducing the light transmittance. Opacity (JIS P-8138) is 80
% Or more, and more preferably 85 to 100%. As the microporous resin stretched film, for example, the following three films can be exemplified. Examples of the first stretched microporous resin film include a biaxially stretched thermoplastic resin film having microporosity containing an inorganic fine powder or an organic filler in a ratio of 8 to 65% by weight (Japanese Patent Publication No. JP 54-31032 A,
U.S. Pat. No. 3,775,521, U.S. Pat. No. 4,191,719, U.S. Pat.
616, U.S. Pat. No. 4,560,614).

As the second stretched microporous resin film, a uniaxially or biaxially stretched thermoplastic film containing 0 to 40% by weight of a white inorganic fine powder is used as a core layer. Synthetic paper in which a uniaxially stretched film of a thermoplastic resin containing 10 to 65% by weight of fine powder is provided as a paper-like layer (Japanese Patent Publication No. 46-46)
40794, JP-A-57-149363,
JP-A-57-181829 and the like.

This synthetic paper has a three-layer structure in which a paper-like layer of a uniaxially stretched film exists on the front and back surfaces of a core layer even if it has a two-layer structure (Japanese Patent Publication No. 46-40794, US Pat.
18950), three to seven layers of synthetic paper having another resin film layer between the paper-like layer and the core layer (Japanese Patent Publication No. 50-29738, Japanese Patent Application Laid-Open No. 57-14936).
No. 3, JP-A-56-126155 and JP-A-5-126155.
No. 7-181829, U.S. Pat. No. 4,472,22
No. 7). Also, on the back surface of these synthetic papers, metal salts of propylene / ethylene copolymer and ethylene / (meth) acrylic acid copolymer (Na, Li, Zn,
K), three or more synthetic paper sheets provided with a heat seal layer (IV) made of a resin having a lower melting point than the resin of the base layer (I) such as chlorinated polyethylene, ethylene-vinyl acetate copolymer or the like. (Japanese Patent Publication No. 3-13973).

A particularly preferred microporous resin stretched film base layer (I) is a uniaxially stretched or biaxially stretched thermoplastic resin film containing 0 to 40% by weight of a white inorganic fine powder and / or an organic filler. As a core layer (A), a uniaxially stretched thermoplastic resin film containing 0 to 65% by weight of a white inorganic fine powder and / or an organic filler is provided on both sides of the core layer.
This is a laminated stretched film provided as B ′). As a method for producing such a synthetic paper having a three-layer structure, for example, a thermoplastic resin film containing 0 to 40% by weight, preferably 8 to 25% by weight of an inorganic fine powder and / or an organic filler is used. The film is unidirectionally stretched at a temperature lower than the melting point, and the inorganic fine powder and / or the organic filler is coated on both sides of the obtained uniaxially stretched film in an amount of 0 to 65% by weight, preferably 3 to 65% by weight.
A method of laminating a molten film of a thermoplastic resin containing 10% to 65% by weight, more preferably 10 to 65% by weight, and then stretching the laminated film in a direction perpendicular to the above direction can be mentioned. The synthetic paper produced by this method is a film in which a paper-like layer is uniaxially oriented and has many fine voids, and the core layer is a biaxially oriented laminated structure.

As the third stretched microporous resin film, the second stretched microporous resin film may be further provided on the paper-like layer side of the second stretched microporous resin film with a thickness of 0.1 to 20 containing no inorganic fine powder.
Synthetic paper provided with a transparent thermoplastic resin laminate layer of μm (JP-B-4-60437,
JP-B 1-60411, JP-A-61-3748, U.S. Pat. No. 4,663,216). High gloss printing can be performed on this synthetic paper.

Specifically, a multilayer having a surface layer and a back layer made of a uniaxially stretched film of a thermoplastic resin containing 8 to 65% by weight of an inorganic fine powder is used as a core layer with a biaxially stretched film of a thermoplastic resin as a core layer. Synthetic paper comprising a film as a support, a transparent film layer of a thermoplastic resin containing no inorganic fine powder provided on the surface layer side of the support, and further provided with a primer coating layer having an antistatic function (Japanese Patent Application Laid-Open No. -374
No. 8) or a uniaxially stretched thermoplastic resin film in which a biaxially stretched thermoplastic resin film is used as a core layer and at least one surface of the core layer contains an inorganic fine powder in a ratio of 8 to 65% by weight. Paper comprising a laminate of a paper-like layer made of a thermoplastic resin film and a surface layer made of a uniaxially stretched thermoplastic resin film, wherein the thickness (t) of the surface layer is present in the paper-like layer. Assuming that the average particle size of the inorganic fine powder to be formed is (R), a synthetic paper (Japanese Patent Publication No. 1-60411) made of a multilayer resin film characterized by satisfying the following formula (2) is exemplified. Can be.

[Formula 2] R ≧ t ≧ 0.1 × R (2) Also in the synthetic paper having the multilayer structure, the heat-sealable resin layer (IV) is provided on the back surface similarly to the second microporous resin stretched film. It may be provided.

These stretched microporous resin films are microporous synthetic papers made of a stretched resin film having fine voids inside the film. Its opacity (JIS
P-8138) is preferably 80% or more, more preferably 85% or more, and the thickness is preferably 30 to 300 μm.
m, more preferably 50 to 150 μm. The porosity calculated by the following equation (1) is preferably 10 to 60.
%, More preferably 15 to 45%. Ρ in equation (1)
₀ represents the true density of the support, and ρ ₁ is the density of the support (J
ISP-8118), but the true density is approximately equal to the density before stretching unless the material before stretching contains a large amount of air.

[0015]

(Equation 3)

Examples of the thermoplastic resin used as a synthetic paper material include high-density polyethylene, polypropylene, polyolefin resins such as poly (4-methyl-1-pentene), polyamide, polyethylene terephthalate, polybutylene terephthalate, and mixtures thereof. Can be exemplified. Among them, polypropylene and high-density polyethylene are preferable from the viewpoint of water resistance and chemical resistance.
When polypropylene is used for the core layer, a thermoplastic resin having a melting point lower than that of polypropylene such as polyethylene, polystyrene, or ethylene-vinyl acetate copolymer is blended in an amount of 3 to 25% by weight in order to improve stretchability. preferable.

As the inorganic fine powder, for example, calcium carbonate, calcined clay, silica, diatomaceous earth, talc, titanium oxide, barium sulfate and the like can be used. The particle size is preferably from 0.03 to 7 μm. As the organic filler, it is preferable to select a filler made of a resin different from the thermoplastic resin as the main component. For example, when the thermoplastic resin film is a polyolefin-based resin film, polymers such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6, cyclic olefin, polystyrene, and polymethacrylate are used as organic fillers. A resin having a melting point (for example, 170 to 300 ° C.) or a glass transition temperature (for example, 170 to 280 ° C.) higher than the melting point of the polyolefin resin can be used.

The stretching ratio is preferably 4 to 10 times in both the longitudinal and transverse directions. The stretching temperature is 130 to 162 ° C. when the resin is a propylene homopolymer (melting point: 164 to 167 ° C.).
The temperature is preferably 110 to 120 ° C for high-density polyethylene (melting point 123 to 134 ° C), and 104 to 120 ° C for polyethylene terephthalate (melting point 246 to 252 ° C). The stretching speed is preferably from 50 to 350 m / min. Microporous resin stretched film base layer (I)
Has a thickness of preferably 30 to 300 μm, more preferably 40 to 100 μm.

(2) Heat-Sealable Resin Adhesive Layer (IV) The heat-sealable resin adhesive layer is formed so that the lid material is melt-bonded to the food container by heating. A heat-sensitive adhesive resin is used for the heat-sealing resin adhesive layer. Examples of the heat-sensitive adhesive resin include ethylene / acrylic acid copolymer, ethylene / vinyl acetate copolymer, low-density polyethylene, metal salt of ethylene / (meth) acrylic acid copolymer (so-called Surlyn; trade name), chlorine Polyethylene,
Examples thereof include those having a melting point of 60 to 135 ° C. such as chlorinated polypropylene. These can be formed, for example, by applying and drying a resin solution in which a heat-sensitive adhesive resin is dissolved or dispersed in an organic solvent such as toluene, xylene, or tetralin. The thickness of the heat-sealable resin adhesive layer (IV) is preferably 1 to 50 μm, more preferably 2 to 40 μm.

(3) Gas barrier resin film layer (I)
I) The gas barrier resin film layer is formed to greatly reduce the permeability of water vapor, oxygen, and the like, and uses a gas barrier resin. As the gas barrier resin, polyethylene terephthalate, polyethylene-
Moisture permeability (JIS Z-) of saturated polyesters such as 2,6-naphthalate, polyamides such as nylon 6, nylon 12, and nylon 6,6, aromatic polycarbonates, polyvinylidene chloride, ethylene-vinyl alcohol copolymers, etc.
0208) is 100 g / m ² · 24 hr or less, preferably 50 g / m ² · 24 hr or less, and the oxygen permeability (JIS
Z-1707) is 300cc / m ² · 24hr · atm
Or less, preferably 200 cc / m ² · 24 hr · atm
Use the following: The gas barrier resin film layer may or may not be stretched. Also,
The thickness of the gas barrier resin film layer (II) is preferably 6 to 40 μm, more preferably 8 to 20 μm.

(4) Inorganic Oxide Thin Film (III) In order to further improve the gas barrier properties of the lid material, an inorganic oxide thin film (III) is formed on the surface of the gas barrier resin film layer (II). Inorganic oxide thin films include amorphous Al ₂ O ₃ , SiOx, SnOx, ZnOx, Ir
Ox (x is a number of 1 to 2) or the like can be used. Among these inorganic oxides, amorphous Al ₂ O ₃ , Si
Ox is preferred in terms of transparency and workability, and SiOx is preferred in terms of gas barrier properties. The thickness of these thin films is restricted by transparency, vapor deposition rate, gas barrier properties, film winding properties and the like, and is preferably 5 to 600 nm, more preferably 20 to 500 nm. When the thickness is less than 5 nm, the gas barrier property becomes insufficient, and when the thickness is more than 600 nm, transparency is deteriorated, and the inorganic oxide thin film itself tends to crack or peel. The inorganic oxide thin film preferably has a light transmittance of 75% or more and is transparent.

As a vapor deposition method for forming an inorganic oxide thin film, an inorganic oxide is vapor-deposited under vacuum (1 × 10 ⁻⁶ to 1 × 10 ⁻³ Torr) in a high-frequency induction heating type vapor deposition machine. (See JP-B-53-12953 and JP-A-62-101428), or a gas flow containing an organic silicon compound, oxygen and an inert gas which has been evacuated in advance and evaporated in a vacuum deposition apparatus under vacuum. A method in which plasma is generated by discharge to deposit SiOx on a molded article in the vapor deposition machine (Japanese Patent Application Laid-Open No. 64-87772).
U.S. Pat. No. 4,557,946 and U.S. Pat. No. 4,599,678). Regarding the thin film formation method, see Industrial Materials No. 3 published in November 1990.
Vol. 8, No. 14, pp. 104-105, ion plating, high-frequency plasma CVD, electron beam (EB)
It is classified as a vapor deposition method or a sputtering method, and its principle is introduced.

The determination of the crystallinity or the amorphousness of the aluminum oxide can be easily measured by an ordinary X-ray diffractometer using Cu Kα ray. For example, when crystalline α-Al ₂ O ₃ is contained, the diffraction angle 2θ is 43.39 degrees or 57.5.
A clear diffraction peak appears at a position such as 6 degrees. β-Al ₂
In the case of O ₃ , the diffraction angle 2θ is 66.65 degrees or 33.43.
A position diffraction peak such as a degree appears. The crystal particle size can also be measured from the half width of these diffraction peaks.
In addition, unique diffraction peaks can be similarly measured for other crystalline aluminum such as γ-Al ₂ O ₃ and δ-Al ₂ O ₃ . In the case of amorphous aluminum oxide, a specific diffraction peak is not measured by an X-ray diffractometer. The non-crystalline aluminum oxide referred to here is one in which specific diffraction is not observed by X-ray diffraction.

(5) Adhesive layer Depending on the type of the gas barrier resin film layer (II), the film layer (II) and the inorganic oxide thin film (III)
In some cases, the adhesiveness with the adhesive is insufficient. In such a case, a primer (adhesive) (I) is interposed between the gas barrier resin film layer (II) and the inorganic oxide thin film (III).
a) can be applied to form a primer layer (Ia). Examples of such a primer include polyester polyol / polyisocyanate and polyether polyol / polyisocyanate of a polyurethane-based primer. The coating amount of the primer is generally 0.5 to 5 g / m ² (solid content).

Lamination (adhesion) of microporous resin stretched film base layer (I) and gas barrier resin film (II)
Is used when producing the microporous resin stretched film (I),
The gas barrier resin film may be co-extruded with the filler-containing resin film and stretched to simultaneously produce a laminate of the microporous resin stretched film (I) and the gas barrier resin film (II). Alternatively, the two may be adhered using the primer. The bonding surface may be on the gas barrier resin film (II) side or the inorganic oxide thin film (III) side.

(6) Other Layers The lid material is made of the above-mentioned stretched microporous resin film (I), primer layer (Ia), gas barrier resin film (I).
In addition to I), the inorganic oxide thin film (III) and the heat-sealing resin film (IV), a woven or non-woven fabric is used to contribute to the improvement of the rigidity, tear resistance and light opacity of the lid. , A light shielding layer, a pulp paper, a foamed resin layer and the like may be provided between the microporous resin stretched film base layer (I) and the gas barrier resin film layer (II). Further, a protective layer may be provided on the surface of the printing (P) provided on the surface of the above-mentioned stretched microporous resin film (I), or the inorganic oxide thin film provided on the gas barrier resin film (II) ( When III) is on the surface side, a protective layer may be provided on the surface of the inorganic oxide thin film (III).

The lid material used for food containers of the present invention, the moisture permeability (JIS Z-0208) is 5g / m ² · 24hr or less, preferably 2g / m ² · 24hr or less, more preferably 1 g / m ² · 24 hr or less, and the oxygen permeability (J
IS Z-1707) is 5cc / m ² · 24hr · at
m, preferably ² cc / m ² · 24 hr · atm or less, more preferably 1 cc / m ² · 24 hr · atm or less. By satisfying these conditions, it is possible to prevent deterioration of the contents and deterioration of the contents. Furthermore, in order to use for packaging of contents which dislike light rays such as milk pudding and yogurt, the total light transmittance of the lid material (JIS K-710)
5) needs to be 5% or less.

When the thickness of each layer is thin and the light shielding property is insufficient, the back surface of the stretched microporous resin film (I) is
1-5μ thickness by offset or gravure printing
m black solid printing is performed to form a shielding layer, or a titanium oxide whisker, an oxidized titanium oxide whisker is added to a primer layer for bonding a microporous resin stretched film base layer (I) and a gas barrier resin film layer (II). Include a large amount (5 to 75% by weight) of a white filler such as titanium fine particles, and form a shielding layer by applying the primer adhesive in an amount of ² to 10 g / m ^2. The rate can be 5%. The thickness of the lid is 50-350μ
m, preferably 80 to 150 μm to provide flexibility.

[0029]

[Production Example 1]

Production of Stretched Microporous Resin Film (1) Propylene homopolymer having a melt flow rate (MFR) of 0.8 g / 10 min (ASTM D1238: 230 ° C., 2.16 kg load) (melting point: about 164 to 167)
C.) 81% by weight, a composition (a) in which 3% by weight of high-density polyethylene and 16% by weight of calcium carbonate having an average particle size of 1.5 μm were kneaded by an extruder set at 270 ° C., and then sheet-shaped. And cooled by a cooling roll to obtain a non-stretched sheet. After the sheet was heated again to 150 ° C., it was stretched five times in the machine direction using the difference in peripheral speed of the roll group to obtain a five-fold stretched film.

(2) 54% by weight of a propylene homopolymer (melting point: about 164 to 167 ° C.) having an MFR of 4 g / 10 min.
The composition (b) mixed with 46% by weight of calcium carbonate having an average particle size of 1.5 μm is kneaded at 210 ° C. by a separate extruder, and extruded into a sheet by a die, and is obtained in the step (1). The laminated film having a three-layer structure was obtained by laminating on both sides of the obtained 5-fold longitudinally stretched film. Next, the three-layer laminated film was cooled to 60 ° C., and then cooled again to about 155 ° C.
Then, the film was stretched 7.5 times in the transverse direction using a tenter and annealed at 165 ° C. Then 60 ° C
After a corona discharge treatment on both sides, the ears were slit and the thickness of the three-layer structure (uniaxial stretching / biaxial stretching / uniaxial stretching) 80 μm (B / A / B = 10 μm / 60 μm / 10
μm) with a opacity of 87% and a porosity of 31
%, Density 0.78 g / cm ³ , water vapor permeability (air permeability; temperature 40 ° C., relative humidity 90%) 3.4 g / m ² · 2
4 hr, oxygen permeability 920 cc / m ² · 24 hr · at
m, a stretched resin film having a total light transmittance of 14% was obtained.

Production Example 2 Production of Stretched Microporous Resin Film In Production Example 1, the thickness of each layer (B / A / B) was 15 μm.
The opacity is 82%, the porosity is 33%, and the density is 0.79 g / c, except that the width of the die lip is changed so as to obtain m / 30 μm / 15 μm (total thickness 60 μm).
A stretched resin film having m ³ , a water vapor transmission rate of 6.0 g / m ² · 24 hr, an oxygen transmission rate of 1,360 cc / m ² · 24 hr · atm, and a total light transmittance of 21% was obtained.

Production Example 3 Production of Stretched Microporous Resin Film (1) 55% by weight of propylene homopolymer (melting point: about 164 to 167 ° C.) of 4 g / 10 minutes MFR, 25% by weight of high-density polyethylene and average particle A composition obtained by mixing 20% by weight of calcium carbonate having a diameter of 1.5 μm was kneaded by an extruder set at 270 ° C., extruded into a sheet shape, and further cooled by a cooling roll to obtain a non-stretched sheet.

(2) After the sheet was heated again to 150 ° C., it was stretched 5 times in the machine direction to obtain a 5 times stretched film. Then, the film was heated again to 155 ° C. and stretched 7.5 times in the transverse direction using a tenter.
Annealing treatment was performed at 5 ° C. Thereafter, the mixture was cooled to 60 ° C., and after corona discharge treatment on both sides, the ears were slit and the density was 0.88 g / cm ³ , the opacity was 86%, the wall thickness was 60 μm,
Porosity 37%, water vapor transmission rate 7.2g / m ² · 24h
r, oxygen permeability 1,680 cc / m ² · 24 hr · at
m, a biaxially stretched film having a total light transmittance of 23% was obtained.

Production Example 4 Production of Stretched Microporous Resin Film Propylene homopolymer having an MFR of 4 g / 10 min.
A mixture of 70% by weight, 8% by weight of high-density polyethylene and 22% by weight of calcium carbonate having an average particle size of 1.5 μm is defined as (A), and has an MFR of 20 g / 10
Minute propylene homopolymer (melting point: about 164 to 167 ° C)
A mixture containing 40% by weight and 60% by weight of calcium carbonate having an average particle size of 1.5 μm is referred to as (B), and these are melt-kneaded at 270 ° C. in separate extruders. (B) was laminated and co-extruded on both sides thereof, and cooled by a cooling device to obtain a non-stretched three-layer sheet. After heating this sheet to 135 ° C., a uniaxially stretched film stretched 5 times in the machine direction was obtained.

Further, both surfaces of the film were subjected to corona discharge treatment to obtain a stretched film having a three-layer structure (uniaxial stretching / uniaxial stretching / uniaxial stretching). This film has a thickness of 80 μm
(B / A / B = 10 μm / 60 μm / 10 μm) laminated film having an opacity of 87%, a porosity of 29%, a density of 0.85 g / cm ³ , and a water vapor permeability (air permeability: temperature 40
(° C., relative humidity 90%) 3.0 g / m ² · 24 hr, oxygen permeability 920 cc / m ² · 24 hr · atm, and total light transmittance 16%.

[Production Example 5] Production of SiO ₂ vapor-deposited gas barrier film A biaxially stretched polyethylene terephthalate film having a thickness of 12 μm (stretched 3 times in length and 3 times in width) was coated on one surface with an isocyanate compound (Nihon Polyurethane Industry Co., Ltd.). Co., Ltd .:
A primer comprising a mixture of Coronate L (trade name) and a saturated polyester (manufactured by Toyobo Co., Ltd .: Byron 300; trade name) in a ratio of 50:50 is applied and dried to obtain a resin having a thickness of about 0.1 μm. A layer was formed. 8 on the resin layer
Under vacuum of 10 ^-5 Torr, SiO ₂ having a purity of 99.9% is heated and evaporated by a high-frequency induction heating method to a thickness of 100 n.
m of SiO ₂ film was formed. The resulting film has a water vapor transmission rate of 0.9 g / m ² · 24 hr and an oxygen transmission rate of 0.2 g / m ² · 24 hr.
5 cc / m ² · 24 hr · atm, total light transmittance is 80
%Met.

Production Example 6 Production Example of SiO ₂ Vapor Deposition Gas Barrier Film In the same manner as in Production Example 5, except that the thickness of the silicon oxide thin film was 300 nm, the water vapor transmission rate was 0.7 g / m ^2. 24
hr, oxygen permeability is 0.4 cc / m ² · 24 hr · at
m, a biaxially oriented film of SiO ₂ deposited polyethylene terephthalate having a total light transmittance of 77% was obtained.

[Production Example 7] Production of amorphous aluminum oxide vapor-deposited gas barrier film A biaxially stretched polyethylene terephthalate film having a thickness of 12 μm (three times in the machine direction and three times in the transverse direction) was coated on one surface with an isocyanate compound. A primer prepared by mixing 50% of 50:50 (manufactured by Nippon Polyurethane Industry Co., Ltd .: Coronate L) and saturated polyester (manufactured by Toyobo Co., Ltd .: Byron 300) is applied and dried to a thickness of about 0.
A 1 μm resin layer was formed. Next, 8 on the resin layer
Under a vacuum of × 10 ^-5 Torr, Al ₂ O ₃ having a purity of 99.9% was heated and evaporated by a high frequency induction heating method to a thickness of 100 mm.
An amorphous aluminum oxide film having a thickness of nm was formed. This Al
₂ O ₃ evaporated polyethylene terephthalate biaxially stretched film has a water vapor transmission rate of 3 g / m ² · 24 hr, an oxygen transmission rate of 3 cc / m ² · 24 hr · atm, and a total light transmittance of 86%.
Met.

[Production Example 8] Production of non-crystalline aluminum oxide vapor-deposited gas barrier film In the same manner as in Production Example 7, except that the thickness of the Al ₂ O ₃ thin film was changed to 500 nm, the water vapor transmission rate was 2 g / m ² ···. 24hr,
An amorphous aluminum oxide-deposited polyethylene terephthalate biaxially stretched film having an oxygen transmittance of ² cc / m ² · 24 hr · atm and a total light transmittance of 85% was obtained.

[0040]

Example 1 After the offset printing was performed on the surface of the microporous stretched resin film having a thickness of 80 μm obtained in Production Example 1, a polyurethane primer (BLS manufactured by Toyo Morton Co., Ltd .: -2080A and BLS-2080
A mixture of 15 parts by weight of titanium oxide and 4 g / m ² (solid content) of 85 parts by weight of a mixture of B;
The film side of the SiO ₂ vapor-deposited polyethylene terephthalate biaxially stretched film obtained in Production Example 5 was adhered, and a hot-melt adhesive for coating was used as a heat-sealing resin layer on the SiO ₂ vapor-deposited surface (manufactured by Hirodyne Co., Ltd .: Extruded coating 7560; (Trade name) was applied at 10 g / m ² (solid content) and dried, and a lid material having a wall thickness of about 106 μm was produced. This lid material had an opacity of 98%, a total light transmittance of 2%, a water vapor permeability of 0.2 g / m ² · 24 hr, and an oxygen permeability of 0.3 cc / m ² · 24 hr · atm.

A cylindrical polypropylene miso container was filled with 200 g of miso, and the lid material was placed on the printed surface facing upward so that the heat-seal resin layer was on the miso container side.
A hot plate was heat-sealed at 190 ° C. for 30 seconds in a circumferential direction with a width to seal. It was confirmed by a metal detector from the outside of the obtained miso container that metal powder was not mixed. This miso container
It was left for 3 months in a constant temperature room at a relative humidity of 75% and a temperature of 25 ° C. Next, the lid material was opened, and the presence or absence of discoloration and flavor of the miso were examined, and none of them was inferior to the miso before filling.

[0042]

Example 2 In Example 1, the microporous resin stretched film obtained in Production Example 1 was replaced with the wall thickness 6
Except that a microporous resin stretched film of 0 μm is used, the thickness is about 86 μm, and the water vapor permeability is 0.1 g / m ^2.
・ 24hr, Oxygen permeability 0.3cc / m ²・ 24hr ・
Atm, an opacity of 89% and a lid material with a total light transmittance of 5% were obtained. Next, a cylindrical polystyrene yogurt container was filled with 100 g of yogurt, the lid was heat-sealed and sealed in the same manner as in Example 1, and metal powder was mixed with a metal detector from the outside of the obtained yogurt container. Confirmed that there is no.
This was refrigerated at 5 ° C. for 2 weeks, the lid was opened, and the appearance and flavor of the yogurt were examined, but there was no change in the appearance or flavor of the yogurt.

[0043]

Example 3 In Example 1, instead of the microporous stretched resin film obtained in Production Example 1, the thickness 6
A thickness of about 87 μm and a water vapor transmission rate of 0.2 g / m ^2.
24 hr, oxygen permeability 0.4 cc / m ² · 24 hr · a
tm, an opacity of 89% and a total light transmittance of 4% were obtained. Next, 100 g of cheese was filled in a cylindrical polypropylene cheese container, and the lid material was heat-sealed and sealed in the same manner as in Example 1, and metal powder was mixed in with a metal detector from the outside of the obtained cheese container. Confirmed that there is no. 5 ℃
For 3 weeks, and then the lid was opened. The appearance and flavor of the cheese were examined, but there was no change in the appearance and flavor of the cheese.

[0044]

Example 4 In Example 1, the thickness of the microporous resin stretched film obtained in Production Example 1 was replaced with the wall thickness of 8 obtained in Production Example 4.
A thickness of about 107 μm, an opacity of 99%, a total light transmittance of 1%, a water vapor permeability of 0.2 g / m ² · 24 hr, and an oxygen permeability of 0.4 cc are the same except that a microporous stretched resin film of 0 μm is used. / M ² · 24 hr · atm. In the same manner as in Example 1, 200 g of miso was filled, the opening was heat-sealed, and after checking from the outside of the container that there was no metal powder mixed in with a metal detector, the relative humidity was 75% and the temperature was 25 ° C. It was left in a constant temperature room for 3 months. Next, the lid material was opened and the miso was examined, but no change was found in the quality of the miso.

[0045]

Example 5 In Example 1, the SiO 2 obtained in Production Example 5 was used.
Instead of _second deposition polyethylene terephthalate biaxially stretched film, the thickness in the same manner except for using the a SiO ₂ deposition polyethylene terephthalate biaxially stretched film obtained in Production Example 6 to obtain a lid material of about 108μm. This lid material has an opacity of 99%, a total light transmittance of 1%, and a water vapor permeability of 0.1%.
1 g / m ² · 24 hr, oxygen permeability 0.2 cc / m ²
・ 24 hr · atm. In the same manner as in Example 1,
After filling with 200 g of miso and heat-sealing the opening, after confirming from the outside of the container that no metal powder was mixed with a metal detector, the container was left in a constant temperature room at a relative humidity of 75% and a temperature of 25 ° C. for 3 months. . Next, the lid material was opened and the miso was examined, but no change was found in the quality of the miso.

[0046]

Example 6 In Example 1, the SiO 2 obtained in Production Example 5 was used.
Instead of _second deposition polyethylene terephthalate biaxially stretched film, other similarly other is the use of aluminum oxide vapor deposited polyethylene terephthalate biaxially stretched film obtained in Production Example 7 In the same manner the thickness of about 107Myuemu, opacity 98
%, Total light transmittance 2%, water vapor permeability 3 g / m ² · 24
hr, a cover material having an oxygen permeability of ² cc / m ² · 24 hr · atm was obtained. In the same manner as in Example 1, 200 g of miso was filled, the opening was heat-sealed, and a metal detector was used to confirm that no metal powder was mixed in from outside the container.
% In a constant temperature room at a temperature of 25 ° C. for 3 months. Next, the lid material was opened and the miso was examined, but no change was found in the quality of the miso.

[0047]

Example 7 In Example 1, the SiO 2 obtained in Production Example 5 was used.
_The thickness was about 108 μm, the opacity was 99%, and the total light transmittance was 2%, except that the aluminum oxide-deposited polyethylene terephthalate biaxially-stretched film obtained in Production Example 8 was used instead of the bi-deposited polyethylene terephthalate biaxially-stretched film. A lid material having a water vapor permeability of 2 g / m ² · 24 hr and an oxygen permeability of 1 cc / m ² · 24 hr · atm was obtained. In the same manner as in Example 1, 200 g of miso was filled, the opening was heat-sealed, and after checking from the outside of the container that no metal powder was mixed with a metal detector, the relative humidity was 75% and the temperature was 25 ° C.
In the constant temperature room for 3 months. Next, the lid material was opened and the miso was examined, but no change was found in the quality of the miso.

[0048]

Example 8 After performing offset printing on the film side surface of the biaxially stretched SiO ₂ deposited polyethylene terephthalate film obtained in Production Example 6, a polyurethane primer (BLS-2080A manufactured by Toyo Morton Co., Ltd.) was applied to the printed surface.
A mixture of BLS-2080B and 85 parts by weight) was applied with an adhesive obtained by mixing 15 parts by weight of titanium oxide at 4 g / m ² (solid content), and the microporous stretched resin film having a thickness of 80 μm obtained in Production Example 1 was applied. And applying a hot-melt adhesive for coating (Hirodyne Co., Ltd .: 7560 for extrusion coating) as a heat-sealing resin layer to the opposite side of the microporous stretched resin film at 10 g / m ² (solid content) and drying. A lid material having a thickness of about 107 μm was manufactured.

The opacity of this cover material was 98%, the total light transmittance was 1%, the water vapor permeability was 0.1 g / m ² · 24 hr,
The oxygen permeability was 0.2 cc / m ² · 24 hr · atm. In the same manner as in Example 1, 200 g of miso was filled,
After heat sealing the opening, it was confirmed from the outside of the container that there was no metal powder mixed in with a metal detector, and then left in a constant temperature room at a relative humidity of 75% and a temperature of 25 ° C. for 3 months. Then it was opened. There was no change in the quality of the miso.

[0050]

Example 9 A polyurethane primer (BLS-2080A and BLS-2080A, manufactured by Toyo Morton Co., Ltd.) was applied on both sides of a microporous resin stretched film having a thickness of 60 μm obtained in Production Example 3.
-2080B) was applied in an amount of 0.5 g / m ² (solid content). Next, the SiO ₂ vapor-deposited polyethylene terephthalate biaxially stretched film of SiO ₂ obtained in Production Example 6 was manufactured.
Gravure printing was performed on the vapor deposition side, and the printed surface was bonded to the microporous stretched resin film coated with the above primer. A low-density polyethylene film having a thickness of 40 μm is adhered to the other surface (back surface) of the stretched microporous resin film coated with the primer to a thickness of about 114 μm, a water vapor permeability of 0.2 g / m ² · 24 hr, oxygen 0.4cc / permeability
A cover material having m ² · 24 hr · atm, opacity of 89% and total light transmittance of 3% was obtained. In the same manner as in Example 2, 100 g of yogurt was filled, the opening was heat-sealed, and after checking from the outside of the container that no metal powder was mixed with a metal detector, this was refrigerated at 5 ° C. for 2 weeks. Then, the lid was opened and the appearance and flavor of the yogurt were examined, but no change was observed in the appearance and flavor of the yogurt.

[0051]

Example 10 The SiO obtained in Production Example 6 in Example 9
A thickness of about 114 μm and a water vapor transmission rate of 0.3 g / m ² were similarly obtained except that the aluminum oxide-deposited polyethylene terephthalate biaxially stretched film obtained in Production Example 8 was used instead of the bi-deposited polyethylene terephthalate biaxially stretched film.
・ 24hr, Oxygen permeability 0.6cc / m ²・ 24hr ・
Atm, an opacity of 89% and a total light transmittance of 3% were obtained. In the same manner as in Example 2, 100 g of yogurt was filled, the opening was heat-sealed, and after checking from the outside of the container that no metal powder was mixed with a metal detector, the mixture was heated at 5 ° C. for 2 hours.
After refrigerated for a week, the lid was opened, and the appearance and flavor of the yogurt were examined, but there was no change in the appearance and flavor of the yogurt.

[0052]

The lid material of the present invention is excellent in light blocking properties and gas barrier properties. Miso, yogurt, cheese, etc. containers formed by performing secondary processing using this lid material can be used as containers. Inspection of the content for the presence of metal powder can be performed by a metal detector from the outside of the container.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a lid material according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a miso container using a lid according to an embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a lid member according to an eighth embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a lid member according to a ninth embodiment of the present invention.

[Explanation of symbols]

 I Stretched Microporous Resin Film Ia Primer Layer II Gas Barrier Resin Film Layer III Inorganic Oxide Thin Film Layer IV Heat Sealable Resin Adhesive Layer 1 Lid A Core Layer B Surface Layer B'Back Layer P Printing 2 Container 3 Miso 4 Heat sealing part

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 3E084 AB10 BA05 BA06 BA07 BA09 CC01 CC03 CC07 CC08 FA09 FD13 GB08 4F100 AA00A AA00C AA00H AA19C AA20C AK01A AK01D AK01E AK01H AR00B BA04 BA05 BA07 BA10A BA10A BA10A BA10B HB31E JA12C JA20A JD01D JD01E JD03 JD04 JK06 JL12B JN08A YY00 YY00A YY00B YY00C YY00D

Claims (13)

[Claims] 1. An opacity (JIS P-8138) of 8
Gas barrier properties in which a heat-sealable resin adhesive layer (IV) is laminated on one surface of a microporous resin stretched film base layer (0% or more) and an inorganic oxide thin film layer (III) is provided on the other surface. A laminate having a layer structure obtained by laminating a resin film layer (II), wherein the laminate has a moisture permeability (JIS Z
-0208) is 5 g / m ² · 24 hr or less, and the oxygen permeability (JIS Z-1707) is 5 cc / m ² · 24 hr.
-A lid material characterized by being atm or less. 2. The stretched microporous resin film base layer (I) has a thickness of 30 to 300 μm, the heat-sealable resin layer (IV) has a thickness of 1 to 50 μm, and the gas barrier resin film layer (II). )), And the thickness of the inorganic oxide thin film layer (III) is 5 to 600 nm.
2. The lid according to claim 1, wherein the total thickness of the lid is 50 to 350 [mu] m. 3. An opacity (JIS P-8138) of 8
0% or more of the microporous resin stretched film base layer (I)
A laminate having a layer structure in which a gas barrier resin film layer (II) provided with an inorganic oxide thin film layer (III) is laminated, and a heat seal resin adhesive layer (IV) is further laminated thereon. The moisture permeability of the laminate (JIS Z-
0208) is 5 g / m ² · 24 hr or less, and the oxygen permeability (JIS Z-1707) is 5 cc / m ² · 24 hr ·
atm or less. 4. The gas barrier resin film layer (II) between the microporous resin stretched film base layer (I) and the inorganic oxide thin film layer (III). 4. The lid material according to any one of items 3 to 3. 5. The method according to claim 1, wherein said inorganic oxide thin film layer (III) is provided between said microporous resin stretched film base layer (I) and said gas barrier resin film layer (II). 4. The lid material according to any one of items 3 to 3. 6. The lid material according to claim 1, wherein printing (P) is performed on one surface of the stretched microporous resin film base layer (I). 7. The method according to claim 6, wherein the surface on which the printing (P) is performed is a surface opposite to the surface on which the gas barrier resin film layer (II) is formed. The lid material as described. 8. The gas barrier resin film layer (I)
The cover material according to any one of claims 1 to 5, wherein printing (P) is performed on one surface of I). 9. The cover material according to claim 1, wherein printing (P) is performed on one surface of the inorganic oxide thin film layer (III). 10. The total light transmittance of the cover material (JIS K-7)
105) is 5% or less of the lid material according to any one of claims 1 to 9. 11. The inorganic oxide thin film layer (III),
The lid material according to any one of claims 1 to 10, which is a silicon oxide thin film layer or an amorphous aluminum oxide thin film layer. 12. The uniaxially stretched thermoplastic resin film or the biaxially stretched thermoplastic resin film wherein the microporous resin stretched film base layer (I) contains 0 to 40% by weight of a white inorganic fine powder and / or an organic filler. To the core layer (A)
And white inorganic fine powder and / or
Or a laminated stretched film provided as a front and back layer (B, B ') with a uniaxially stretched thermoplastic resin film containing 0 to 65% by weight of an organic filler. 4. The lid material according to 1. 13. The lid material according to claim 12, wherein the microporous resin stretched film base layer (I) has a porosity represented by the following formula (1) of 10 to 60%. (Equation 1)