JPWO2018207824A1 - the film - Google Patents

Abstract

A film including a base material layer and a seal layer, the film having a thickness of 20 to 150 μm, wherein one surface layer of the film is a base material layer, and another one surface layer is a film having a seal layer, The sealing layer contains a resin composition, has a thickness of 5 to 100 μm, has a crystallization index of 0.680 to 0.900 on the surface of the sealing layer on the film surface, and has the sealing layer on the film surface adhered to the adherend (X ), When the film is heat-sealed to the adherend (X) under the conditions of a temperature of 160 ° C., a time of 1 second, a seal bar width of 10 mm and a pressure of 450 kPa, the resin composition of the seal layer is heat-sealed. A film wherein the ratio of the thickness of the portion formed by elution from the portion to the non-heat-sealed portion and solidification and the thickness of the sealing layer of the non-heat-sealed portion is 1.80 to 2.20. Adherend (X): an adherend having a melt flow rate of 3.0 to 4.0 g / 10 minutes and a thickness of 350 to 550 μm made of impact-resistant polystyrene having a Vicat softening temperature of 95 to 100 ° C.

Description

  The present invention relates to a film and a lid including the film.

  Patent Document 1 discloses an ethylene-based copolymer obtained by copolymerizing ethylene and a vinyl alkyl ester formed by blown film molding and two kinds of ethylene-α-olefin copolymers having different crystallinities. A laminated resin film having a sealing layer is described.

JP-A-6-212036

  The present invention suppresses blocking of a film that is stacked so that the seal layers on the film surface are in contact with each other, and sealability and easy-openability when the seal layer on the film surface is heat-sealed to a polypropylene adherend and a polystyrene adherend. And a lid provided with the film.

The present invention provides the following [1] to [8].
[1] A film including a base layer and a seal layer, and having a thickness of 20 μm or more and 150 μm or less, wherein one surface layer of the film is a base layer and another surface layer is a seal layer. A seal layer containing a resin composition, having a thickness of 5 μm or more and 100 μm or less, and having a crystallization index [D730 / D720] of 0 on the surface of the seal layer on the film surface measured by the multiple reflection ATR-IR method. In the state where the sealing layer on the film surface is in contact with the following adherend (X), the film is sealed on the following adherend (X) at a temperature of 160 ° C. for 1 second at a temperature of 160 ° to 0.900. When heat-sealing under the conditions of a bar width of 10 mm and a pressure of 450 kPa, the resin composition of the sealing layer elutes from the heat-sealed portion to the non-heat-sealed portion and is solidified. The film whose ratio to the thickness of the sealing layer is 1.80 or more and 2.20 or less.
Adherend (X): Thickness made of impact-resistant polystyrene having a melt flow rate of 3.0 g / 10 min or more and 4.0 g / 10 min or less and a Vicat softening temperature of 95 ° C. or more and 100 ° C. or less, 350 μm or more The film according to [1], wherein the adherend [2] [D730 / D720] having a thickness of 550 μm or less is 0.680 or more and 0.750 or less.
[3] When the film is heat-sealed to the adherend (X) under the conditions of a temperature of 160 ° C., a time of 1 second, a seal bar width of 10 mm and a pressure of 450 kPa, the resin composition of the seal layer is not heat-sealed from the heat-sealed portion. The film according to [1] or [2], wherein the ratio of the thickness of the part formed by elution and solidification to the part and the thickness of the sealing layer of the non-heat-sealed part is 1.85 or more and 2.20 or less.
[4] A resin composition containing the following components (A), (B), and (C), wherein the total amount of the components (A), (B), and (C) is 100% by weight.
The content of the monomer unit based on the unsaturated ester contained in the whole polymer in the resin composition and the content of the component (C) are each 3% by weight or more and 10% by weight or less, and 2% by weight Not less than 10% by weight.
Component (A): an ethylene polymer having a density of 850 kg / m ³ or more and 940 kg / m ³ or less Component (B): ethylene-unsaturated containing a monomer unit based on ethylene and a monomer unit based on an unsaturated ester Ester copolymer component (C): alicyclic saturated hydrocarbon resin [5] The melt flow rate of component (A) measured at 190 ° C. under a load of 21.18 N according to JIS K7210 is 3 g / The resin composition according to [4], which is 10 minutes or less.
[6] The resin composition according to [4] or [5], further comprising an antiblocking agent.
[7] A film including a layer containing the resin composition according to any one of [4] to [6].
[8] A film including a layer containing the resin composition according to any one of [4] to [6] and a layer containing an ethylene-based polymer,
A film in which at least one surface layer of the two surface layers of the film is a layer composed of the resin composition according to [4] to [6].
[9] A film including a layer containing the resin composition according to any one of [4] to [6] and a layer not containing an ethylene-based polymer,
A film in which at least one of the two surface layers of the film is a layer containing the resin composition according to [4] to [6].
[10] A lid including the film according to any one of [1] to [3] and [7] to [9].

  According to the present invention, it is possible to suppress the blocking between the films stacked so that the seal layers on the film surface are in contact with each other, the sealing property when the seal layer on the film surface is heat-sealed to the polypropylene adherend and the polystyrene adherend, and An easy-opening film having easy-opening properties and a lid can be provided.

In this specification, the density is a value measured by the method A according to the method specified in JIS K7112-1980 after performing the annealing described in JIS K6760-1995. In the present specification, the melt flow rate (hereinafter sometimes referred to as MFR) is a value measured under the conditions of a temperature of 190 ° C. and a load of 21.18 N in accordance with JIS K7210.

  The film of the present invention is a film including a base layer and a seal layer. The film of the present invention is an easy-open film.

The crystallization index (hereinafter sometimes referred to as [D730 / D720]) of the surface of the seal layer on the film surface is measured by the following method.
The infrared absorption spectrum of the seal layer on the film surface is measured by the multiple reflection ATR-IR method. In the measured 725 cm ^-1 or more 735cm ^-1 or less in the range of infrared absorption spectrum, the height from the baseline to the D730 peak height is the maximum. In the measured range below 715 cm ^-1 or more 725 cm ^-1 in the infrared absorption spectrum, the height from the baseline to the D720 peak height is the maximum. By dividing D730 by D720, the crystallization index of the seal layer surface on the film surface is obtained.
A peak having a maximum height in a region of 715 cm ^-1 or more and less than 725 cm ^-1 is a peak derived from a crystalline component and an amorphous component of the resin composition contained in the seal layer. A peak having a maximum height in a region of 725 cm ^{-1 to} 735 cm ^-1 is a peak derived from a crystal component of the resin composition contained in the seal layer.
As the value of D730 / D720 is smaller, the resin composition contained in the seal layer on the film surface has more amorphous components, and thus the seal layer on the film surface is more sticky. In this case, blocking between the seal layers on the film surface is likely to occur.

The value of D730 / D720 is preferably 0.690 or more, more preferably 0.700 or more. When the value of D730 / D720 is less than 0.680, blocking between the seal layers is likely to occur.
The value of D730 / D720 is preferably 0.850 or less, more preferably 0.800 or less. When the value of D730 / D720 exceeds 0.900, there is a possibility that the hermeticity of the heat-sealed film is reduced.
The value of D730 / D720 is preferably 0.690 or more and 0.850 or less, and more preferably 0.700 or more and 0.800 or less.

  "Poly-ball" means that when a film and an adherend are heat-sealed, the resin composition of the sealing layer elutes from the heat-sealed portion to the non-heat-sealed portion and solidifies near the heat-sealed portion. This is a portion formed by performing the process, and is a portion having a larger thickness than the sealing layer of the non-heat-sealed portion. The greater the thickness of the “poly pool”, the higher the heat sealing strength.

With the sealing layer on the film surface in contact with the adherend (X) shown below, the film was heated on the adherend (X) under the conditions of a temperature of 160 ° C., a time of 1 second, a seal bar width of 10 mm, and a pressure of 450 kPa. Seal and obtain a sample. Using a cryomicrotome, the obtained sample is cut in the thickness direction of the film in parallel with the heat seal width to obtain a test piece. The cut surface of the obtained test piece is used as the observation surface. An image is obtained by measuring the observation surface with a phase contrast microscope. Using the obtained image, poly reservoir thickness (hereinafter sometimes referred to as T _1.), And the thickness of the sealing layer of the non-heat-sealed portion (hereinafter sometimes referred to as T _0.) Measured I do.
Adherend (X): Thickness made of impact-resistant polystyrene having a melt flow rate of 3.0 g / 10 min or more and 4.0 g / 10 min or less and a Vicat softening temperature of 95 ° C. or more and 100 ° C. or less, 350 μm or more An adherend having a thickness of 550 μm or less.
The “impact polystyrene” in the present specification is an impact polystyrene having a Charpy impact strength of 9 to 13 kJ / m ² . The Charpy impact strength is measured according to JIS K7111.

The non-heat-sealed portion refers to a portion where the sealing layer on the film surface and the adherend (X) are not bonded. T ₀ is the thickness of the sealing layer on the film surface of the non-heat-sealed portion.
T ₁ is determined by the following method.
(1) The end point of the adhesive portion of the sealing layer and the adherend and P _1.
(2) determining the shortest distance between the tangent line L and P ₁ of the sealing layer and the boundary between the layer of non-adherent.
(3) Among the distances determined in (2), whose distance is short, and the larger than the thickness of the sealing layer of the non-heat-sealed portion and T _1.

The ratio of the thickness of the poly pool to the thickness of the sealing layer in the non-heat-sealed portion (hereinafter sometimes referred to as T ₁ / T ₀ ) is preferably 1.83 or more and 2.20 or less, It is more preferable that it is from .85 to 2.18.
When T ₁ / T ₀ is less than 1.80, the sealing property of the film at the time of heat sealing decreases.

  The thickness of the film is preferably 25 μm or more and 120 μm or less, more preferably 30 μm or more and 100 μm or less. The thickness of the film is measured by slicing the film in the thickness direction using a cryomicrotome and observing the cross section of the obtained test piece with an optical microscope.

(Seal layer)
The seal layer of the film contains, for example, a resin composition containing the components (A), (B) and (C).
Component (A): an ethylene polymer having a density of 850 kg / m ³ or more and 940 kg / m ³ or less Component (B): ethylene-unsaturated containing a monomer unit based on ethylene and a monomer unit based on an unsaturated ester Ester copolymer component (C): alicyclic saturated hydrocarbon resin Based on 100% by weight of the total weight of the resin components contained in the resin composition,
The total content of components (A), (B) and (C) is preferably at least 70% by weight, more preferably at least 80% by weight, even more preferably at least 90% by weight. , 95% by weight or more.

<Component (A)>
The density of the component (A) is preferably from 880 to 930 kg / m ³ , more preferably from 910 to 928 kg / m ³ .
Component (A) is substantially free of monomer units based on unsaturated esters. The content of the monomer unit based on the unsaturated ester in the component (A) is preferably less than 5% by weight, more preferably less than 2% by weight. Component (A) is substantially free of monomer units based on alicyclic saturated hydrocarbons. The content of the monomer unit based on the alicyclic saturated hydrocarbon in the component (A) is preferably 5% by weight or less, and more preferably 2% by weight or less.

  The MFR of the component (A) is preferably from 0.1 to 30 g / 10 minutes, more preferably from 0.2 to 15 g / 10 minutes, and even more preferably from 0.3 to 3 g / 10 minutes.

The component (A) includes a high-pressure low-density polyethylene having a density of 850 kg / m ³ or more and 940 kg / m ³ or less (hereinafter, may be referred to as “component (A-1)”), and a density of 850 kg. / M ³ or more and 940 kg / m ³ or less (hereinafter sometimes referred to as “component (A-2)”).
The resin composition may include only one type of the component (A), or may include two or more types of the component (A). The resin composition may include only one type of the component (A-2), or may include two or more types of the component (A-2). The resin composition may include only the component (A-1), may include only the component (A-2), or may include both the component (A-1) and the component (A-2).

  The high-pressure low-density polyethylene is an ethylene polymer produced by a high-pressure radical polymerization method. As a method for producing high-pressure low-density polyethylene, in a pressure-resistant polymerization reactor, ethylene or an organic peroxide is used as a polymerization initiator, and ethylene is continuously produced under a pressure of 1000 to 2500 atm and a temperature of 150 to 300 ° C. A method of polymerizing is exemplified.

  The MFR of the component (A-1) is preferably from 0.1 to 30 g / 10 minutes, more preferably from 0.2 to 15 g / 10 minutes, and still more preferably from 0.3 to 3 g / 10 minutes. .

The density of the component (A-1) is preferably 910 to 930 kg / m ³ , more preferably 915 to 928 kg / m ³ , and still more preferably 920 to 925 kg / m ³ .

  Component (A-2) is a copolymer containing a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 or more carbon atoms. Component (A-2) is a copolymer containing a monomer unit based on ethylene and a monomer unit based on at least one monomer selected from α-olefins having 4 to 20 carbon atoms. preferable.

Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, and 1-octene. . The α-olefin is preferably an α-olefin having 4 to 8 carbon atoms, and more preferably 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene from the viewpoint of availability.
Component (A-2) may contain only one type of monomer unit based on an α-olefin, or may contain two or more types of monomer units.

  Component (A-2) may include monomer units based on ethylene and α-olefin monomers. Examples of monomers other than ethylene and α-olefin include conjugated dienes such as butadiene and isoprene, non-conjugated dienes such as 1,4-pentadiene, acrylic acid, and methacrylic acid.

  The content of the monomer unit based on ethylene in the component (A-2) is preferably 80 to 97% by weight based on 100% by weight of the total weight of the component (A-2). The content of the monomer unit based on the α-olefin is preferably 3 to 20% by weight based on 100% by weight of the total weight of the component (A-2).

  Component (A-2) includes ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-octene copolymer, ethylene -1-butene-1-hexene copolymer, ethylene-1-butene-4-methyl-1-pentene copolymer, ethylene-1-butene-1-octene copolymer, and ethylene-1-hexene-1 -Octene copolymer, preferably ethylene-1-hexene copolymer and ethylene-1-butene-1-hexene copolymer.

  The MFR of the component (A-2) is preferably from 0.1 to 30 g / 10 minutes, more preferably from 0.2 to 15 g / 10 minutes, and still more preferably from 0.3 to 3 g / 10 minutes. .

The density of the component (A-2) is preferably 880 to 930 kg / m ³ , and more preferably 910 to 925 kg / m ³ .

  Examples of the polymerization method of the component (A-2) include bulk polymerization, solution polymerization, slurry polymerization, gas-phase polymerization, and high-pressure ionic polymerization. Bulk polymerization refers to a method of performing polymerization using a liquid olefin at a polymerization temperature as a medium. Solution polymerization or slurry polymerization refers to a method in which polymerization is carried out in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, and octane. Gas phase polymerization refers to a method in which a gaseous monomer is used as a medium and the gaseous monomer is polymerized in the medium. These polymerization methods may be any of a batch type and a continuous type, and may be any of a single-stage type performed in a single polymerization tank and a multi-stage type performed in a polymerization apparatus in which a plurality of polymerization reaction tanks are connected in series. May be. The polymerization conditions such as the polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, and polymerization time in the polymerization step may be appropriately determined.

  Examples of the catalyst used for producing the component (A-2) include a Ziegler-Natta catalyst and a single-site catalyst.

  Examples of the method for producing the component (A-2) include the methods described in JP-A-4-11604, JP-A-2006-233207, JP-A-2007-269997, JP-A-2009-161779, and JP-A-2009-256661.

As the component (A-2), Sumikasen (registered trademark) EP, Sumikasen (registered trademark) E, Exelen (registered trademark) GMH, Exelen (registered trademark) FX (all manufactured by Sumitomo Chemical Co., Ltd.), Evolu (registered trademark) ), Tuffmer (registered trademark) (manufactured by Prime Polymer Co., Ltd.), Harmolex (registered trademark), Kernel (registered trademark) (manufactured by Nippon Polyethylene Co., Ltd.), Enable (registered trademark), Exceed (registered trademark) (all ExxonMobil) Chemical), ELITE (registered trademark) and AFFINITY (registered trademark) (manufactured by The DOW Chemical Company).

<Component (B)>
Examples of the monomer unit based on an unsaturated ester include a monomer unit based on an α, β-unsaturated carboxylic acid alkyl ester and a monomer unit based on a vinyl carboxylate.
Component (B) is substantially free of monomer units based on alicyclic saturated hydrocarbons. The content of the monomer unit based on the alicyclic saturated hydrocarbon in the component (B) is preferably 5% by weight or less, more preferably 3% by weight or less.
The resin composition may include only one type of the component (B), or may include two or more types of the component (B).

α, β-unsaturated carboxylic acid alkyl esters include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate.
Vinyl carboxylate includes vinyl acetate, vinyl propionate, vinyl butanoate, and vinyl benzoate.
Monomer units based on unsaturated esters are preferably monomer units based on methyl acrylate, monomer units based on ethyl acrylate, monomer units based on butyl acrylate, monomer units based on methyl methacrylate, And a monomer unit based on vinyl acetate.

  As the component (B), ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-acetic acid Vinyl copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butanoate copolymer, and ethylene-vinyl benzoate copolymer, preferably, ethylene-methyl acrylate copolymer, ethylene-ethyl An acrylate copolymer, an ethylene-butyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, and an ethylene-vinyl acetate copolymer are preferable, and an ethylene-vinyl acetate copolymer is more preferable.

  In the component (B), a part of the monomer unit may be modified by hydrolysis or the like. Examples of the modified ethylene-unsaturated ester copolymer include a saponified ethylene-vinyl acetate copolymer.

  The MFR of the component (B) is preferably from 0.01 to 50 g / 10 min, more preferably from 0.1 to 20 g / min, even more preferably from 1.5 to 10 g / 10 min.

  The upper limit of the content of the monomer unit based on the unsaturated ester contained in the component (B) is 100% by the total weight of the monomer unit based on ethylene and the monomer unit based on the unsaturated ester contained in the component (B). The content of the monomer unit based on the unsaturated ester contained in the component (B) is preferably 50% by weight, more preferably 40% by weight, and still more preferably 30% by weight, (% By weight) is preferably 5% by weight, more preferably 10% by weight, and still more preferably 15% by weight. The content (% by weight) of the monomer unit based on the unsaturated ester contained in the component (B) is preferably 5% by weight or more and less than 50% by weight, and more preferably 10% by weight or more and 40% by weight or less. More preferably, the content is 15% by weight or more and 30% by weight or less.

  As a method for producing the component (B), ethylene and an unsaturated ester are copolymerized in the presence of a radical generator at 50 to 400 MPa at 100 to 300 ° C. in the presence or absence of a suitable solvent or chain transfer agent. A high pressure radical polymerization method may be used. By adjusting the polymerization conditions of the high-pressure radical polymerization, the average molecular weight of the component (B), the content of the unsaturated ester in the component (B), and the like can be controlled.

  Examples of the component (B) include Evatate (registered trademark), Smitate (registered trademark), ACRIFT (registered trademark) (all manufactured by Sumitomo Chemical Co., Ltd.), Evaflex (registered trademark), Nucrel (registered trademark), and Elvaloy. (Registered trademark) AC (manufactured by DuPont Mitsui Polychemicals), Novatec (registered trademark) EVA (manufactured by Nippon Polyethylene Corporation), Ultracene (registered trademark), Mersen (registered trademark) H (manufactured by Tosoh Corporation), UBE polyethylene (EVA) (Ube Maruzen Polyethylene Co., Ltd.), Elvax (registered trademark), APPEEL (registered trademark) (manufactured by DU PONT DE NEMOURS AND COMPANY).

<Component (C)>
Component (C) may include a monomer unit based on a monomer other than the alicyclic saturated hydrocarbon. Examples of the monomer other than the alicyclic saturated hydrocarbon include an aromatic hydrocarbon and an alicyclic unsaturated hydrocarbon. With respect to 100% of the total number of monomer units contained in the component (C), the number of monomer units based on alicyclic saturated hydrocarbon is preferably 70% or more, and more preferably Δ% or more.
As the component (C), a resin obtained by polymerizing a petroleum fraction containing a hydrocarbon having 4 to 10 carbon atoms after cyclization and dimerization, and a hydrogen of a resin obtained by polymerizing a cyclic diene compound such as cyclopentadiene. Additives, aromatic hydrocarbon resins and resins obtained by intranuclear hydrogenation of aliphatic hydrocarbon / aromatic hydrocarbon copolymer resins are exemplified. The component (C) can be obtained by partially or completely hydrogenating a hydrocarbon polymer having 4 to 10 carbon atoms in a cracked oil fraction by-produced in producing ethylene, propylene, or the like. The resin composition may include only one type of the component (C), or may include two or more types of the component (C).

  The weight average molecular weight of the component (C) is preferably from 800 to 1900, more preferably from 1,000 to 1800.

  The Vicat softening point of the component (C) is preferably 110 ° C. or higher, more preferably 130 ° C. or higher. The Vicat softening point of the component (C) is determined by a ring and ball method.

  The content of the component (C) is 2% by weight or more and 10% by weight or less based on 100% by weight of the total amount of the components (A), (B) and (C). The content of the component (C) contained in the entire polymer in the resin composition is preferably from 2.5% by weight to 9% by weight, and more preferably from 3% by weight to 8% by weight.

With respect to 100% by weight of the total amount of the components (A), (B) and (C),
The content of the monomer unit based on the unsaturated ester contained in the whole polymer in the resin composition is 3% by weight or more and 10% by weight or less, preferably 4% by weight or more, more preferably 8% by weight. Or less, and may be 4% by weight or more and 8% by weight or less. By adjusting the content of the components (A), (B) and (C) or the content of the monomer unit based on the unsaturated ester contained in the component (B), the total polymer in the resin composition is adjusted. Can control the content of the monomer unit based on the unsaturated ester contained in.
The content of the monomer unit based on the unsaturated ester contained in the entire polymer in the resin composition is set to 3% by weight or more and 10% by weight or less, and By setting the content of the component (C) to 2% by weight or more and 10% by weight or less with respect to% by weight, D730 / D720 becomes 0.680 or more and 0.900 or less, and T1 / T0 becomes 1.80 or more and 2 or more. .20 or less.

The content of the component (A) is preferably 50% by weight or more and 90% by weight or less based on 100% by weight of the total amount of the components (A), (B) and the component (C) contained in the resin composition. And more preferably 65% by weight or more and 85% by weight or less.
The content of the component (B) is preferably 10% by weight or more and 50% by weight or less based on 100% by weight of the total amount of the components (A), (B) and (C) contained in the resin composition; More preferably, the content is 15% by weight or more and 30% by weight or less.
The total amount of the components (A), (B) and (C) is preferably at least 90% by weight, more preferably at least 〇〇% by weight, based on 100% by weight of the total amount of the resin composition. .
The total amount of components (A), (B) and (C) is preferably at least 95% by weight, more preferably at least 98% by weight, based on 100% by weight of the total amount of all polymers in the resin composition. 100% by weight is more preferred.

  Additives may be added to the resin composition as needed. Additives include antiblocking agents, antioxidants, lubricants, antistatic agents, and processability improvers.

  Antiblocking agents include silica, diatomaceous earth, calcium carbonate, talc, methyl methacrylate polymer, and aluminosilicate. The addition amount of the antiblocking agent is preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). is there.

The anti-blocking agent has a refractive index of 1.48 or more and 1.55 or less, a particle diameter (D50) at an integrated fraction of 50% of a volume-based particle size distribution of 6 μm or more and 15 μm or less, and the following formula (1) Fine particles having a weight change rate E of less than 5% by weight (hereinafter sometimes referred to as component (D)) are preferred.
E = 100 (G−F) / F (1)
(In the formula (1), E is a weight change rate (% by weight). F is a fine particle dried under reduced pressure at a temperature of 110 ° C. until the weight loss rate per hour becomes 0.1% by weight or less. G represents the weight (g) of the fine particles after the measurement, and G represents the weight (g) of the fine particles after holding the fine particles subjected to the measurement of F under normal pressure at a relative humidity of 75% and a temperature of 40 ° C. for 24 hours. ).)
The resin composition may include only one type of component (D), or may include two or more types of component (D).

  The refractive index of the component (D) is more preferably 1.49 or more and 1.52 or less. The refractive index is measured by the critical angle method.

  The particle diameter (D50) at an integrated fraction of 50% of the volume-based particle size distribution of the component (D) is more preferably 6 μm or more and 9 μm or less, and still more preferably 6 μm or more and 8 μm or less. The volume-based particle size distribution of the component (D) is measured by a laser diffraction / scattering method.

The particle diameter (D90) at an integrated fraction of 90% of the volume-based particle size distribution of the component (D) is preferably 9 μm or more from the viewpoint of increasing the transparency of the obtained film.
D90 of the component (D) is preferably 18 μm or less, more preferably 16 μm or less, still more preferably 15 μm or less, and particularly preferably 14 μm, from the viewpoint of reducing blocking between the obtained seal layers. It is as follows.

  Component (D) is at least one kind of fine particles selected from the group consisting of methyl methacrylate polymer fine particles, sodium calcium aluminosilicate fine particles, sodium aluminosilicate fine particles, calcined kaolin fine particles, calcined diatomaceous earth fine particles, and calcined silica fine particles. Preferably, more preferably, methyl methacrylate polymer fine particles, sodium calcium aluminosilicate fine particles, at least one type of fine particles selected from the group consisting of sodium aluminosilicate fine particles, from the viewpoint of enhancing the transparency of the film, still more preferably Sodium calcium aluminosilicate fine particles.

  The content of the component (D) in the resin composition is preferably 30,000 ppm or less, more preferably 27,000 ppm or less, from the viewpoint of transparency and appearance of the film containing the resin composition. It is preferably at most 20,000 ppm, particularly preferably at most 17,000 ppm. In addition, from the viewpoint of preventing blocking between the seal layers, preferably at least 3,000 ppm, more preferably at least 5,000 ppm, further preferably at least 10,000 ppm, particularly preferably at least 15,000 ppm. Yes, preferably 3,000 ppm or more and 30,000 ppm or less, more preferably 5,000 ppm or more and 27,000 ppm or less, still more preferably 10,000 ppm or more and 20,000 ppm or less, and particularly preferably 15,000 ppm or more. It is not more than 17,000 ppm.

  As antioxidants, 2,6-di-t-butyl-p-cresol (BHT), tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (chiba) -Specialty Chemicals, trade name: IRGANOX 1010) and n-octadecyl-3- (4'-hydroxy-3,5'-di-t-butylphenyl) propionate (trade name, manufactured by Ciba Specialty Chemicals) : Phenol-based stabilizers such as IRGANOX 1076); phosphite-based stabilizers such as bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite and tris (2,4-di-t-butylphenyl) phosphite. Agent; and 6- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propoxy] -2 Phenol-phosphites such as 4,4,8,10-tetra-t-butyldibenzo [d, f] [1,3,2] dioxaphosphepin (trade name: Sumilizer GP, manufactured by Sumitomo Chemical Co., Ltd.) Functional stabilizers may be mentioned. The amount of the antioxidant to be added is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.1 part by weight, based on 100 parts by weight of the total of the components (A) and (B). Department.

Examples of the lubricant include erucamide, higher fatty acid amide, and higher fatty acid ester. The amount of the lubricant to be added is preferably 0.01 to 1 part by weight, more preferably 0.03 to 0.5 part by weight, based on 100 parts by weight of the total of the components (A) and (B). is there.
Examples of the antistatic agent include glycerin esters of fatty acids having 8 to 22 carbon atoms, sorbitan esters, and polyethylene glycol esters. The amount of the antistatic agent to be added is preferably 0.01 to 1 part by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the total of the components (A) and (B) in the composition. 0.5 parts by weight.
Examples of the processability improver include fatty acid metal salts such as calcium stearate. The amount of the processability improver to be added is preferably 0.01 to 1 part by weight, more preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of the total of the components (A) and (B). Parts by weight.

  The additive may be added after previously blending the component (A), the component (B), and the component (C) contained in the resin composition, and any of the component (A) or the component (B) may be added. Alternatively, they may be added to each of them, and may be used as a masterbatch blended with either component (A) or component (B).

  As a method for producing the resin composition, a known blending method can be used. Known blending methods include a method of dry blending each polymer and a method of melt blending. Examples of the dry blending method include a method using various blenders such as a Henschel mixer and a tumbler mixer. Examples of the melt blending method include a method using various mixers such as a single screw extruder, a twin screw extruder, a Banbury mixer, and a hot roll.

The film includes a base layer and a seal layer, and one surface of the film is a base layer, and another surface is a seal layer. The film may have a layer other than the substrate layer and the seal layer.
The film can be manufactured by a lamination method of laminating a single-layer film consisting of only a seal layer or a multilayer film having a seal layer, a base material layer and layers other than the seal layer to a base material. Examples of the lamination method include a dry lamination method, a wet lamination method, and a sand lamination method.

A single-layer film consisting of only a sealing layer and a multilayer film having a sealing layer and a layer other than a base material layer and a sealing layer can be produced by blown film molding.
The layer other than the base material layer and the seal layer includes a layer containing an ethylene-based polymer. Examples of the ethylene-based polymer include a high-pressure method low-density polyethylene and an ethylene-α-olefin copolymer.
A multilayer film having a seal layer, a base material layer, and a layer other than a seal layer has a seal layer and a layer containing an ethylene polymer, and at least one of the surfaces of the multilayer film is a seal layer. ). The multilayer film (α) can be manufactured by co-extrusion of a resin composition to be a seal layer and an ethylene-based polymer, followed by inflation film molding.

  The thickness of the sealing layer of the film is 5 μm or more and 100 μm or less, preferably 10 μm or more and 80 μm or less, and more preferably 15 μm or more and 50 μm or less. The thickness of the seal layer of the film is measured by slicing the film in the thickness direction using a cryomicrotome and observing the cross section of the obtained test piece with an optical microscope.

  Examples of the substrate include a layer containing cellophane, paper, paperboard, woven fabric, aluminum foil, polyamide resin such as nylon 6 or nylon 66, polyester resin such as polyethylene terephthalate or polybutylene terephthalate, or stretched polypropylene.

  The film can be used as a lid for various containers. Examples of the container material include propylene homopolymer, propylene random copolymer, high-density polyethylene, ethylene-α-olefin copolymer, high-pressure low-density polyethylene, and polystyrene. The film is used for lids of various foods such as jelly, pudding, yogurt, tofu, instant noodles, noodles, pharmaceuticals, cosmetics, and packaging containers for industrial products.

  Examples of the propylene homopolymer used as the material for the container include Sumitomo Noblen (registered trademark) homograde (manufactured by Sumitomo Chemical Co., Ltd.) and Prime Polypro homograde (manufactured by Prime Polymer Co., Ltd.). Examples of the propylene random copolymer used as a material for the container include a random grade of Sumitomo Noblen (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd.) and a random grade of Prime Polypro (manufactured by Prime Polymer Co., Ltd.). Examples of the high-density polyethylene used as a material for the container include Novatec (registered trademark) HD (manufactured by Nippon Polyethylene Corporation), Hyzex (registered trademark), and Evolu (registered trademark) H (all manufactured by Prime Polymer Co., Ltd.). . Examples of the polystyrene used as a material for the container include a PS plate (manufactured by HIPS) manufactured by Sekisui Molding Industry Co., Ltd.

It is possible to produce a sealed container by stacking the lid and the flange portion of the container body so that the seal layer of the lid including the film and the flange portion of the container body are in contact with each other, and applying heat and pressure and heat sealing the container. it can.
The lid including the film preferably has a heat seal strength of 10 to 25 N / mm, from the viewpoint of achieving both sealing properties and easy opening properties.

(1) Raw resin and additives
Ingredient (A)
PE1: metallocene catalyst linear low-density polyethylene Sumikacene EP GT140 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-1-butene-1-hexene copolymer, MFR 0.9 g / 10 min, density 918 kg / m ³ , Mw / Mn = 8.6, Ea = 69.3 kJ / mol)
PE2: Metallocene catalyst linear low-density polyethylene Sumikacene EFV201 (manufactured by Sumitomo Chemical Co., Ltd., ethylene / 1-hexene copolymer, MFR 2.3 g / 10 min, density 916 kg / m ³ , Mw / Mn = 5.8) , Ea = 35.8 kJ / mol)
Ingredient (B)
OE1: Sumitate KA-30 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-vinyl acetate copolymer, content of monomer unit based on vinyl acetate 28% by weight, MFR 7.0 g / 10 min)
OE2: ACLIFT WK307 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-methyl methacrylate copolymer, content of monomer unit based on methyl methacrylate 25% by weight, MFR 7.0 g / 10 minutes)
Ingredient (C)
TA1: Archon P-140 (manufactured by Arakawa Chemical Co., Ltd., Ring and ball method softening point = 140 ° C)
TA2: Clayton G1657 (manufactured by Clayton Polymer Japan Co., Ltd., styrene-ethylene / butylene-styrene block copolymer SEBS, MFR (230 ° C.) 8 g / 10 minutes, content of styrene alone 13 wt%)
Other AO: Antioxidant Sumilizer GP (Sumitomo Chemical Co., Ltd.)
SA: Lubricant Erucamide AB: Antiblocking agent Minblock SC6 (manufactured by Sibelco, silica, refractive index 1.51)

(2) Heat seal strength The seal layer of the produced laminated film was overlapped so that the following adherends were in contact with each other, and heat sealed using a heat sealer (manufactured by Tester Sangyo Co., Ltd.) under the following sealing conditions to obtain a sample. Was. After conditioning the obtained sample at 23 ° C. for 24 hours or more, a test piece having a seal portion with a seal width of 10 mm and a seal length of 15 mm was cut out in a direction perpendicular to the seal width direction. Next, the seal portion of the obtained test piece was peeled at 180 ° by a tensile tester at a speed of 300 mm / min, and the heat seal strength per 15 mm width was measured. The maximum value of the obtained heat seal strength was adopted. When the heat seal strength is 10 to 25 N / 15 mm, the film has a sealing property and an easy opening property.
Heat sealing conditions Sealing temperature: 160 ° C
Sealing time: 1 second Seal bar width: 10 mm
Seal pressure: 450 kPa
Adherend Adherend 1: Polypropylene sheet (PP)
(Noblen (registered trademark) H501 sheet 0.44 mm thick)
Substrate 2: Impact-resistant polystyrene sheet (HIPS)
(MFR 3.4 g / 10 min, Vicat softening point 96 ° C, PS sheet 0.5 mm thickness, Charpy impact strength 11 kJ / m ² , manufactured by Nippon Plastic Industry Co., Ltd.)

(3) Haze According to ASTM1003, the haze (unit:%) of the blown film (thickness: 60 μm) formed by the method described below was measured. The smaller the haze, the better the transparency.

(4) Internal haze The film is immersed in a transparent cell containing dimethyl phthalate, and the internal haze (unit:%) of the blown film (thickness: 60 μm) formed by the method described below is measured. did. The smaller the internal haze, the better the transparency.

(5) Upper and lower blocking (upper and lower BL, unit: N / m ² )
An inflation film (thickness: 60 μm) formed by a method described below is cut into 10 cm × 10 cm, and the tubes are superimposed so that the insides of the tubes at the time of forming the inflation film are in close contact with each other. ^The sample was allowed to stand for 7 days under a load of ² . After standing, a load required for peeling in the vertical direction at a peeling load speed of 20 g / min was measured using a Mackenzie blocking tester (manufactured by Shimadzu Corporation). The smaller the value, the more excellent the anti-blocking property.

(6) Melt flow rate (MFR, unit: g / 10 minutes)
The MFR was measured by the method A specified in JIS K7210-1995 under the conditions of a temperature of 190 ° C and a load of 21.18N.

(7) Charpy impact strength Charpy impact strength was measured according to JIS K7111.

(8) Content of monomer units based on vinyl acetate
The content of the monomer unit based on vinyl acetate was measured according to JIS K7192.

(9) Production of Masterbatch The components (A) and additives were melt-kneaded in a Banbury kneader at a ratio shown in Table 1 at 160 ° C., and then pelletized by a granulator to produce an additive masterbatch. .

(10) Surface Crystallization Index An infrared spectroscopic spectrum was measured by an attenuated total reflection method [Attenuated Total Reflection (ATR) method] using the apparatus and measurement procedure described below.
・ Apparatus: Fourier exchange infrared spectrophotometer FT / IR-480, multiple reflection measuring device ATR-500M (all manufactured by JASCO), prism KRS-5 / 45 ° (manufactured by Sanyo Science)
・ Measurement mode: Abs
・ Resolution: 4cm-1,
・ Number of accumulation: 32 times,
ATR-IR measurement procedure: The sealing layer on the surface of the film was brought into contact with the upper and lower surfaces of the KRS-5 prism to obtain an infrared absorption spectrum.
The absorbance Abs of the obtained infrared absorption spectrum was set as the vertical axis, and 760 to 674 cm ^-1 was set as the baseline. In 725 cm ^-1 or more 735cm ^-1 or less in the range of the obtained infrared absorption spectrum, the height from the baseline was D730 the maximum peak. In the obtained range of less than 715 cm ^-1 or more 725 cm ^-1 in the infrared absorption spectrum, the height from the baseline was D730 the maximum peak. The surface crystallization index was determined by the following equation.
Surface crystallization index = D730 / D720

(11) Observation with phase contrast microscope With the sealing layer on the film surface in contact with the adherend 2, the film was applied to the adherend 2 at a temperature of 160 ° C., a time of 1 second, a seal bar width of 10 mm, and a pressure of 450 kPa. Then, heat sealing was performed to obtain a sample. Using a cryomicrotome (manufactured by LEICA), the obtained sample was cut in the thickness direction of the film in parallel with the heat seal width to obtain a test piece having a thickness of 6 μm. The cut surface of the obtained test piece was used as the observation surface. Dimethyl phthalate was adhered to a slide glass, and the test piece obtained was placed on the slide glass such that the cross section of the test piece was upward. An image was obtained by measuring the observation surface with a phase contrast microscope of NIKON MICROPHOT FXA (manufactured by Nikon Corporation). Using the obtained images, T ₀ and T ₁ were measured.
The thickness of the seal layer on the film surface in the non-heat-sealed portion was measured.
T ₁ was determined by the following method.
(1) The end point of the adhesive portion of the sealing layer and the adherend 2 was P _1.
(2) was determined shortest distance between the tangent line L and P ₁ of the boundary line between the sealing layer and the adherend 2 other layers.
Among the distances determined in (3) (2), whose distance is short, and the larger than the thickness of the sealing layer of the non-heat-sealed portion was T _1.
T ₀ was measured by slicing the film in the thickness direction using a cryomicrotome and observing the cross section of the obtained test piece with an optical microscope.

(12) Vicat softening point The Vicat softening point was measured under the condition of a load of 50 N by the method specified in JIS K7206.

(Example 1)
[Co-extrusion blown film molding]
An inflation film was manufactured by a co-extrusion inflation molding method such that an outer layer, an intermediate layer, and an inner layer were laminated in this order. As the resin composition for the outer layer and the resin composition for the intermediate layer, ethylene polymer Sumikasen (registered trademark) EFV202 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-1-hexene copolymer, MFR 2.0 g / 10 min, density 925 kg / m ³ ) 80% by weight, 20% by weight of ethylene polymer Sumikasen (registered trademark) F200 (manufactured by Sumitomo Chemical Co., Ltd., high-pressure low-density polyethylene, MFR 2.0 g / 10 minutes, density 924 kg / m ³ ) A resin composition was used. As the resin composition for the inner layer, a resin composition containing PE1, OE1, TA1, and MB1 in the amounts shown in Table 2 was used.
The co-extrusion inflation molding is performed by using a three-layer inflation film processing machine manufactured by Placo with a die temperature of 170 ° C., a total extrusion rate of 30 kg / hour, a blow ratio of 2.0, and a take-up speed of 9.5 m / min. A co-extruded blown film having a thickness composition ratio of 20 μm / 20 μm / 20 μm in the order of outer layer / intermediate layer / inner layer and a total thickness of 60 μm was produced. The outer layer surface of the obtained blown film tube was subjected to corona discharge treatment so as to have a wetting tension of 45 dyn / cm. Table 3 shows the physical properties of the obtained blown film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 5% by weight.
[Laminate film molding]
Using a coater manufactured by Yasui Seiki Co., Ltd., an aliphatic ester-based coating agent “Takelac A-310” and “Takenate A-3” (both manufactured by Mitsui Takeda Chemical Co., Ltd.) were mixed in the following mixing ratio. The liquid was applied to a polyester film having a thickness of 12 μm and a width of 500 mm (trade name “E5102” manufactured by Toyobo Co., Ltd.). The resulting polyester film was pressed against the corona-treated surface of the film obtained in the above example, and then heated in a 40 ° C. oven for 48 hours to obtain a laminated film.
Takerac / takenate / ethyl acetate = 12/1/32 (weight ratio)
The heat seal strength was measured using the laminated film. Table 3 shows the results. Table 4 shows D730 / D720 and T1 / T0 of the laminated film.

(Example 2)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 9.5% by weight.

(Example 3)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 9% by weight.

(Example 4)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 3.4% by weight.

(Example 5)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 8.4% by weight.

(Example 6)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE2, OE1, TA1 and MB2 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 9.5% by weight.

(Example 7)
An inflation film and a multilayer film were obtained in the same manner as in Example 1 except that PE1, OE2, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on methyl methacrylate contained in the inner layer of the blown film was 3.8% by weight.

(Comparative Example 1)
An inflation film and a multilayer film were obtained in the same manner as in Example 1 except that PE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on the unsaturated ester contained in the inner layer of the blown film was 0% by weight.

(Comparative Example 2)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that the amounts of PE1, OE1, and MB1 were as shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 10% by weight.

(Comparative Example 3)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 13% by weight.

(Comparative Example 4)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 12% by weight.

(Comparative Example 5)
An inflation film and a multilayer film were obtained in the same manner as in Example 1 except that PE1, OE1, TA2 and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 11% by weight.

(Comparative Example 6)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 2.8% by weight.

(Comparative Example 7)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 2.8% by weight.

(Comparative Example 8)
An inflation film and a multilayer film were obtained in the same manner as in Example 1 except that PE1, OE1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 3.4% by weight.

(Comparative Example 9)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows D730 / D720 and T1 / T0 of the laminated film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 9.8% by weight.

(Comparative Example 10)
An inflation film and a multilayer film were obtained in the same manner as in Example 1, except that PE1, OE1, TA1, and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows the crystallization index of the seal layer surface of the laminate film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 11.8% by weight.

(Comparative Example 11)
An inflation film and a multilayer film were obtained in the same manner as in Example 1 except that PE1, OE1, TA2 and MB1 were used in the amounts shown in Table 2. Table 3 shows the physical properties of the blown film and the laminated film. Table 4 shows the crystallization index of the seal layer surface of the laminate film. The content of the monomer unit based on vinyl acetate contained in the inner layer of the blown film was 4.8% by weight.

（表２に記載の各成分の配合量の単位は重量％である。）

(The unit of the amount of each component described in Table 2 is% by weight.)

  This patent application claims the priority of Japanese Patent Application No. 2017-094501 (filing date: May 11, 2017), which is hereby incorporated by reference in its entirety. Shall be incorporated.

Claims (4)

A film that includes a base layer and a seal layer, and has a thickness of 20 μm or more and 150 μm or less,
One surface layer of the film is a substrate layer, another one of the film is a seal layer,
The seal layer contains a resin composition, has a thickness of 5 μm or more and 100 μm or less,
The crystallization index [D730 / D720] of the surface of the seal layer on the film surface measured by the multiple reflection ATR-IR method is 0.680 or more and 0.900 or less;
With the sealing layer on the surface of the film in contact with the following adherend (X), the film is heated on the following adherend (X) under the conditions of a temperature of 160 ° C., a time of 1 second, a seal bar width of 10 mm, and a pressure of 450 kPa. When sealing, the ratio of the thickness of the portion formed by the resin composition of the seal layer eluted from the heat-sealed portion to the non-heat-sealed portion and solidified and the thickness of the seal layer in the non-heat-sealed portion is 1.80 or more. 2.20 or less film.
Adherend (X): Thickness made of impact-resistant polystyrene having a melt flow rate of 3.0 g / 10 min or more and 4.0 g / 10 min or less and a Vicat softening temperature of 95 ° C. or more and 100 ° C. or less, 350 μm or more An adherend having a size of 550 μm or less   The film according to claim 1, wherein [D730 / D720] is 0.680 or more and 0.750 or less.   When the adherend (X) is heat-sealed under the conditions of a temperature of 160 ° C., a time of 1 second, a seal bar width of 10 mm and a pressure of 450 kPa, the resin composition of the seal layer elutes from the heat-sealed portion to the non-heat-sealed portion. 3. The film according to claim 1, wherein the ratio of the thickness of the solidified portion to the thickness of the sealing layer in the non-heat-sealed portion is from 1.85 to 2.20. 4.   A lid comprising the film according to claim 1.