WO2018207824A1

WO2018207824A1 - Film

Info

Publication number: WO2018207824A1
Application number: PCT/JP2018/017947
Authority: WO
Inventors: チン劉; 貴明矢野; 直人桑▲崎▼
Original assignee: 住友化学株式会社
Priority date: 2017-05-11
Filing date: 2018-05-09
Publication date: 2018-11-15
Also published as: JPWO2018207824A1; CN110603290A; TW201903008A

Abstract

A film comprising a base layer and a sealing layer and having a thickness of 20-150 μm, the base layer being one surface layer of the film and the sealing layer being the other surface layer. The sealing layer comprises a resin composition and has a thickness of 5-100 μm. The surface of the sealing layer which is a film surface has a crystallization index of 0.680-0.900. When the film-surface sealing layer is kept in contact with an adherend (X) and the film is heat-sealed to the adherend (X) under the conditions of a temperature of 160°C, a time of 1 second, a sealing-bar width of 10 mm, and a pressure of 450 kPa, then some of the resin composition of the sealing layer oozes from the heat-seal part to the non-heat-seal part and solidifies to form a solidified part, the ratio of the thickness of the solidified part to the thickness of the sealing layer in the non-heat-seal part being 1.80-2.20. Adherend (X): an adherend having a thickness of 350-550 μm and comprising an impact-resistant polystyrene that has a melt flow rate of 3.0-4.0 g/10 min and a Vicat softening temperature of 95-100°C.

Description

the film

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

Patent Document 1 includes an ethylene copolymer obtained by copolymerizing ethylene and vinyl alkyl ester formed by inflation film molding, and two types of ethylene-α-olefin copolymers having different crystallinity. A laminated resin film having a sealing layer is described.

JP-A-6-212036

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

The present invention provides the following [1] to [8].
[1] A film including a base material 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 material layer and another one of the surface layers is a seal layer. The seal layer contains a resin composition and has a thickness of 5 μm or more and 100 μm or less, and the crystallization index [D730 / D720] of the surface of the seal layer measured by the multiple reflection ATR-IR method is 0. 680 to 0.900, with the film surface sealing layer in contact with the following adherend (X), the film was attached to the following adherend (X) at a temperature of 160 ° C. for 1 second, When heat-sealing under conditions of a bar width of 10 mm and a pressure of 450 kPa, the thickness of the part formed by elution and solidification of the resin composition of the sealing layer from the heat-seal part to the non-heat-seal part and the non-heat-seal part A film having a ratio to the thickness of the sealing layer of 1.80 to 2.20.
Substrate (X): Thickness of 350 μm or more consisting of impact-resistant polystyrene having a melt flow rate of 3.0 g / 10 min to 4.0 g / 10 min and a Vicat softening temperature of 95 ° C. to 100 ° C. The film according to [1], wherein the adherend [2] [D730 / D720] having a size of 550 μm or less is 0.680 or more and 0.750 or less.
[3] When the film is heat-sealed 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, the resin composition of the sealing layer is non-heat sealed from the heat seal portion. The film according to [1] or [2], wherein the ratio of the thickness of the portion eluted and solidified to the portion and the thickness of the seal layer of the non-heat seal portion 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 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 to 10% by weight, and 2% by weight. The resin composition which is 10 weight% or less above.
Component (A): Ethylene polymer having a density of 850 kg / m ³ or more and 940 kg / m ³ or less Component (B): Ethylene-unsaturation containing monomer units based on ethylene and monomer units based on unsaturated esters Ester copolymer component (C): alicyclic saturated hydrocarbon resin [5] The melt flow rate of component (A) measured under conditions of a temperature of 190 ° C. and a load of 21.18 N in accordance with JIS K7210 is 3 g / The resin composition according to [4], which is 10 minutes or shorter.
[6] The resin composition according to [4] or [5], further comprising an antiblocking agent.
[7] A film comprising a layer comprising the resin composition according to any one of [4] to [6].
[8] A film comprising a layer containing the resin composition according to any one of [4] to [6], and a layer containing an ethylene polymer,
A film in which at least one of the two surface layers of the film is a layer comprising the resin composition according to [4] to [6].
[9] A film comprising a layer containing the resin composition according to any one of [4] to [6] and a layer not containing an ethylene 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 comprising the film according to any one of [1] to [3] and [7] to [9].

According to the present invention, the blocking of the films laminated so that the sealing layers on the film surfaces are in contact with each other is suppressed, and the sealing property when the sealing layer on the film surface is heat sealed to the polypropylene adherend and the polystyrene adherend and An easy-open film having an easy-open property and a lid can be provided.

In this specification, the density is a value measured by the method A according to the method defined in JIS K7112-1980 after 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 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 material layer and a seal layer. The film of the present invention is an easy-open film.

The crystallization index of the surface of the sealing layer on the film surface (hereinafter sometimes referred to as [D730 / D720]) 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 range of 725 cm ⁻¹ or more and 735 cm ⁻¹ or less of the measured infrared absorption spectrum, the height of the peak having the maximum height from the baseline is defined as D730. 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.
The peak having the maximum height in the region of 715 cm ⁻¹ or more and less than 725 cm ⁻¹ is a peak derived from the crystalline component and the amorphous component of the resin composition contained in the seal layer. Peak 725 cm ^-1 or more 735cm ^-1 height in the following areas is maximum is a peak derived from the crystalline component of the resin composition contained in the sealing layer.
The smaller the value of D730 / D720, the more the resin composition contained in the sealing layer on the film surface, the more amorphous components, so the sealing layer on the surface of the film becomes sticky. At this time, blocking between the sealing layers on the film surface tends to occur.

The value of D730 / D720 is preferably 0.690 or more, and more preferably 0.700 or more. When the value of D730 / D720 is less than 0.680, blocking between the seal layers tends to occur.
The value of D730 / D720 is preferably 0.850 or less, and more preferably 0.800 or less. When the value of D730 / D720 exceeds 0.900, the hermeticity of the heat-sealed film may be lowered.
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”, when heat-sealing the film and adherend, the resin composition of the sealing layer elutes from the heat-sealed part to the non-heat-sealed part and solidifies near the heat-sealed part. It is a site | part formed by doing, Comprising: The site | part thicker than the sealing layer of a non-heat-sealed part is said. The thicker the “poly pool”, the higher the heat seal strength.

With the seal layer on the film surface in contact with the adherend (X) 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. The obtained sample is cut in the thickness direction of the film in parallel with the heat seal width using a cryomicrotome to obtain a test piece. Let the cut surface of the obtained test piece be an 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 To do.
Substrate (X): Thickness of 350 μm or more consisting of impact-resistant polystyrene having a melt flow rate of 3.0 g / 10 min to 4.0 g / 10 min and a Vicat softening temperature of 95 ° C. to 100 ° C. An adherend having a size of 550 μm or less.
The “impact resistant polystyrene” in the present specification is an impact resistant polystyrene having a Charpy impact strength of 9 to 13 kJ / m ² . Charpy impact strength is measured according to JIS K7111.

The non-heat seal portion refers to a portion where the seal layer on the film surface and the adherend (X) are not bonded. T ₀ is the thickness of the seal layer on the film surface of the non-heat seal portion.
T ₁ is obtained 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 between the thickness of the poly pool and the thickness of the seal layer of the non-heat seal 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.
If T ₁ / _{T 0} is less than 1.80, the sealing of the film at the time of heat-sealing is reduced.

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

(Seal layer)
The sealing layer of a film contains the resin composition containing a component (A), (B) and (C), for example.
Component (A): Ethylene polymer having a density of 850 kg / m ³ or more and 940 kg / m ³ or less Component (B): Ethylene-unsaturation containing monomer units based on ethylene and monomer units based on unsaturated esters Ester copolymer component (C): alicyclic saturated hydrocarbon resin For 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 70% by weight or more, more preferably 80% by weight or more, and still more preferably 90% by weight or more. 95% by weight or more is particularly preferable.

<Component (A)>
The density of the component (A) is preferably 880 ~ 930kg / ^{m 3,} more preferably 910 ~ 928kg / ^{m 3.}
Component (A) is substantially free of monomeric 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, and 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 preferably less than 2% by weight.

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

As the component (A), a high-pressure method low-density polyethylene having a density of 850 kg / m ³ or more and 940 kg / m ³ or less (hereinafter sometimes referred to as “component (A-1)”), and a density of 850 kg. / ^{m 3} or more 940 kg / ^{m 3} or less is ethylene -α- olefin copolymer (hereinafter, may be referred to as "component (a-2)".) it can be mentioned.
The resin composition may contain only one type of component (A) or two or more types. The resin composition may contain only one type of component (A-2) or two or more types. 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).

High-pressure method low-density polyethylene is an ethylene polymer produced by a high-pressure radical polymerization method. As a method of producing a high-density low-density polyethylene, ethylene is continuously added in a pressure-resistant polymerization reactor using oxygen or an organic peroxide as a polymerization initiator under a pressure of 1000 to 2500 atm and a temperature of 150 to 300 ° C. The method of superposing | polymerizing is mentioned.

The MFR of component (A-1) is preferably 0.1 to 30 g / 10 minutes, more preferably 0.2 to 15 g / 10 minutes, and further preferably 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 comprising 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 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene are more preferable from the viewpoint of availability.
Component (A-2) may contain only one type of monomer unit based on α-olefin, or may contain two or more types.

Component (A-2) may contain monomer units based on monomers of ethylene and α-olefin. 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 relative to 100% by weight of the total weight of the component (A-2). The content of the monomer unit based on α-olefin is preferably 3 to 20% by weight with respect to 100% by weight of the total weight of component (A-2).

As component (A-2), 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 copolymers are mentioned, and ethylene-1-hexene copolymers and ethylene-1-butene-1-hexene copolymers are preferred.

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

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

Component (A-2) polymerization methods include bulk polymerization, solution polymerization, slurry polymerization, gas phase polymerization, and high-pressure ion polymerization. Bulk polymerization refers to a method of performing polymerization using a liquid olefin as a medium at a polymerization temperature. Solution polymerization or slurry polymerization refers to a method in which polymerization is performed in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, and octane. The 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 either batch type or continuous type, and any of single stage type performed in a single polymerization tank and multistage type performed in a polymerization apparatus in which a plurality of polymerization reaction tanks are connected in series. But you can. The polymerization conditions such as polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc. in the polymerization step may be appropriately determined.

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

Examples of the production method of component (A-2) include the production 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, Excellen (registered trademark) GMH, Excellen (registered trademark) FX (all manufactured by Sumitomo Chemical Co., Ltd.), Evolue (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 (manufactured by Chemical), ELITE (registered trademark), and AFFINITY (registered trademark) (manufactured by The DOW Chemical Company).

<Component (B)>
Examples of monomer units based on unsaturated esters include monomer units based on α, β-unsaturated carboxylic acid alkyl esters and monomer units based on carboxylic acid vinyl esters.
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, and more preferably 3% by weight or less.
The resin composition may contain only one type of component (B) or two or more types.

Examples of α, β-unsaturated carboxylic acid alkyl esters include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate.
Carboxylic acid vinyl esters include vinyl acetate, vinyl propionate, vinyl butanoate, and vinyl benzoate.
The monomer unit based on unsaturated ester is preferably a monomer unit based on methyl acrylate, a monomer unit based on ethyl acrylate, a monomer unit based on butyl acrylate, a monomer unit based on methyl methacrylate, And monomer units based on vinyl acetate.

Component (B) includes: ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-acetic acid Examples thereof include vinyl copolymers, ethylene-vinyl propionate copolymers, ethylene-vinyl butanoate copolymers, and ethylene-vinyl benzoate copolymers, preferably ethylene-methyl acrylate copolymers, ethylene-ethyl copolymers. 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 modified ethylene-unsaturated ester copolymers include saponified ethylene-vinyl acetate copolymers.

The MFR of component (B) is preferably 0.01 to 50 g / 10 min, more preferably 0.1 to 20 g / min, and further preferably 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% of the total weight of the monomer unit based on ethylene and the monomer unit based on the unsaturated ester contained in the component (B). Content of monomer units based on unsaturated ester contained in component (B), which is preferably 50% by weight, more preferably 40% by weight, and still more preferably 30% by weight (% by weight) The lower limit of (% 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 preferably 10% by weight or more and 40% by weight or less. More preferably, it is 15 wt% or more and 30 wt% or less.

As a method for producing 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 mentioned. 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 Evertate (registered trademark), Smitate (registered trademark), Aklift (registered trademark) (all manufactured by Sumitomo Chemical Co., Ltd.), Evaflex (registered trademark), Nucrel (registered trademark), Elvalloy (Registered trademark) AC (Mitsui / DuPont Polychemical Co., Ltd.), Novatec (registered trademark) EVA (manufactured by Nippon Polyethylene Co., Ltd.), Ultrasen (registered trademark), Mersen (registered trademark) H (manufactured by Tosoh Corporation), Examples include UBE polyethylene (EVA) (Ube Maruzen Polyethylene Co., Ltd.), Elvax (registered trademark), APPEEL (registered trademark) (manufactured by DU PONT DE NEMOURS AND COMPANY).

<Ingredient (C)>
Component (C) may include a monomer unit based on a monomer other than the alicyclic saturated hydrocarbon. Examples of monomers other than alicyclic saturated hydrocarbons include aromatic hydrocarbons and alicyclic unsaturated hydrocarbons. The number of monomer units based on the alicyclic saturated hydrocarbon is preferably 70% or more, more preferably 0% or more, with respect to 100% of the total number of monomer units contained in the component (C).
Component (C) includes a resin obtained by polymerizing a petroleum fraction containing hydrocarbons 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. Examples thereof include an additive, a resin obtained by hydrogenating an aromatic hydrocarbon resin or an aliphatic hydrocarbon / aromatic hydrocarbon copolymer resin in the nucleus. Component (C) can be obtained by partial or complete hydrogenation of a hydrocarbon polymer having 4 to 10 carbon atoms in a cracked oil fraction by-produced when ethylene, propylene or the like is produced. The resin composition may contain only one type of component (C) or two or more types.

The weight average molecular weight of the component (C) is preferably 800 to 1900, and more preferably 1000 to 1800.

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

The content of the component (C) is 2% by weight or more and 10% by weight or less with respect to 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 2.5% by weight or more and 9% by weight or less, more preferably 3% by weight or more and 8% by weight or less.

For a total amount of 100% by weight of component (A), component (B) and component (C),
The content of monomer units based on unsaturated esters contained in all polymers 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 4 wt% or more and 8 wt% or less. By adjusting the content of components (A), (B) and (C), or the content of monomer units based on unsaturated esters contained in component (B), the total polymer in the resin composition The content of the monomer unit based on the unsaturated ester contained in can be controlled.
The content of monomer units based on unsaturated esters contained in all polymers in the resin composition is 3 wt% to 10 wt%, and the total amount of components (A), (B) and (C) is 100 D730 / D720 is set to 0.680 or more and 0.900 or less, and T1 / T0 is set to 1.80 or more and 2 by setting the content of component (C) to 2 wt% or more and 10 wt% or less with respect to wt%. .20 or less.

The content of the component (A) is preferably 50% by weight or more and 90% by weight or less with respect to 100% by weight of the total amount of the components (A), (B) and the component (C) contained in the resin composition. More preferably, it is 65 wt% or more and 85 wt% or less.
The content of the component (B) is preferably 10% by weight or more and 50% by weight or less with respect to 100% by weight of the total amount of the components (A), (B) and (C) contained in the resin composition, More preferably, it is 15 to 30 weight%.
The total amount of components (A), (B) and (C) is preferably 90% by weight or more, more preferably 0.00% by weight or more with respect to 100% by weight of the total amount of the resin composition. .
The total amount of components (A), (B) and (C) is preferably 95% by weight or more, more preferably 98% by weight or more, with respect to 100% by weight of the total amount of all polymers in the resin composition. More preferred is 100% by weight.

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

Examples of 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 with respect to 100 parts by weight of the total amount of the component (A) and the component (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 the volume-based particle size distribution is 6 μm or more and 15 μm or less, and the following formula (1) Fine particles having a weight change rate E determined by (1) of less than 5% by weight (hereinafter sometimes referred to as component (D)) are preferred.
E = 100 (GF) / F (1)
(In the formula (1), E is the rate of weight change (% by weight). F is a fine particle dried under reduced pressure at a temperature of 110 ° C. until the rate of weight loss per hour is 0.1% by weight or less. G is the weight (g) of the fine particles after having been held for 24 hours under normal pressure at a relative humidity of 75% and a temperature of 40 ° C. ).)
The resin composition may contain only one type of component (D) or two or more types.

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 to 9 μm, still more preferably 6 μm to 8 μm. The volume-based particle size distribution of 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 resulting film.
D90 of the component (D) is preferably 18 μm or less, more preferably 16 μm or less, further preferably 15 μm or less, and particularly preferably 14 μm from the viewpoint of sufficiently reducing blocking between the obtained seal layers. It is as follows.

Component (D) is at least one fine particle 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. More preferably, it is at least one fine particle selected from the group consisting of methyl methacrylate polymer fine particles, sodium calcium aluminosilicate fine particles, and sodium aluminosilicate fine particles, and more preferably from the viewpoint of enhancing the transparency of the film. 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. Preferably it is 20,000 ppm or less, Most preferably, it is 17,000 ppm or less. Further, from the viewpoint of preventing blocking between the seal layers, it is preferably 3,000 ppm or more, more preferably 5,000 ppm or more, still more preferably 10,000 ppm or more, and particularly preferably 15,000 ppm or more. 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, further preferably 10,000 ppm or more and 20,000 ppm or less, and particularly preferably 15,000 ppm or more. 17,000 ppm or less.

Antioxidants include 2,6-di-t-butyl-p-cresol (BHT), tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Ciba・ Specialty Chemicals, trade name: IRGANOXｎ1010) and n-octadecyl-3- (4′-hydroxy-3,5′-di-t-butylphenyl) propionate (Ciba Specialty Chemicals, trade name) : Phenolic 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 And 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy -2,4,8,10-tetra-t-butyldibenzo [d, f] [1,3,2] dioxaphosphepine (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GP) A phytobifunctional stabilizer is mentioned. The addition amount of the antioxidant is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.1 part by weight with respect to 100 parts by weight of the total amount of the component (A) and the component (B). Part.

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

The additive may be added after pre-blending the component (A), the component (B) and the component (C) contained in the resin composition, and either the component (A) or the component (B), Or you may add to each and may use it as a masterbatch blended with either the component (A) or the component (B).

As a method for producing the resin composition, a known blending method may be mentioned. 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 methods 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 material layer and a seal layer, and one surface of the film is a base material layer, and the other surface is a seal layer. The film may have layers other than the base material layer and the seal layer.
The film can be produced by a lamination method in which a single-layer film consisting only of a seal layer or a multilayer film having a seal layer, a base material layer and a layer other than the seal layer is laminated on 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 only of a seal layer and a multilayer film having a seal layer and a layer other than the base layer and the seal layer can be produced by inflation film molding.
Examples of the layer other than the base material layer and the seal layer include a layer containing an ethylene polymer. Examples of the ethylene-based polymer include high-pressure low-density polyethylene and ethylene-α-olefin copolymer.
A multilayer film having a seal layer, a base material layer, and a layer other than the 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 (α ). The multilayer film (α) can be produced by coextrusion of a resin composition serving as a seal layer and an ethylene polymer, followed by inflation film molding.

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

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

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

Examples of the propylene homopolymer used as the container material include Sumitomo Nobrene (registered trademark) homo-grade (manufactured by Sumitomo Chemical Co., Ltd.) and Prime Polypro homo-grade (manufactured by Prime Polymer Co., Ltd.). Examples of the propylene random copolymer used as the material for the container include random grades (manufactured by Sumitomo Chemical Co., Ltd.) of Sumitomo Nobrene (registered trademark) and random grades (manufactured by Prime Polymer Co., Ltd.) of Prime Polypro. Examples of the high-density polyethylene used as the container material include Novatec (registered trademark) HD (manufactured by Nippon Polyethylene Co., Ltd.), Hi-Zex (registered trademark), and Evolue (registered trademark) H (all manufactured by Prime Polymer Co., Ltd.). . As a polystyrene used as a material of a container, PS plate (made by HIPS) made by Sekisui Molding Co., Ltd. is mentioned.

It is possible to produce a sealed container by overlapping the lid and the flange portion of the container body so that the sealing layer of the lid including the film and the flange portion of the container body are in contact with each other, and heat-sealing by applying heat and pressure. 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 performance and easy opening performance.

(1) Raw material resin and additive
Ingredient (A)
PE1: Metallocene-catalyzed 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-catalyzed linear low-density polyethylene Sumikacene E FV201 (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 wt%, MFR 7.0 g / 10 min)
OE2: ACLIFT WK307 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-methyl methacrylate copolymer, content of monomer units based on methyl methacrylate 25% by weight, MFR 7.0 g / 10 min)
Ingredient (C)
TA1: Archon P-140 (Arakawa Chemical Industries, ring ball method softening point = 140 ° C.)
TA2: Kraton G1657 (manufactured by Kraton Polymer Japan Co., Ltd., styrene-ethylene / butylene-styrene block copolymer SEBS, MFR (230 ° C.) 8 g / 10 min, content of styrene alone 13 wt%)
Others AO: Antioxidant Sumilizer GP (Sumitomo Chemical Co., Ltd.)
SA: Lubricant Erucamide AM: Antiblocking agent Minblock SC6 (Sibelco, silica, refractive index 1.51)

(2) Heat-sealing strength Stacked so that the sealing layer of the produced laminate film and the following adherends are in contact with each other, heat sealing is performed using a heat sealer (manufactured by Tester Sangyo Co., Ltd.) under the following sealing conditions to obtain a sample. It 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 180 ° at a speed of 300 mm / min with a tensile tester, and the heat seal strength per 15 mm width was measured. The maximum value of the heat seal strength obtained was adopted. If 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 Sealing bar width: 10mm
Sealing pressure: 450kPa
Substrate <br/> Adherent 1: Polypropylene sheet (PP)
(Noblen (registered trademark) H501 sheet 0.44 mm thickness)
Substrate 2: Impact-resistant polystyrene sheet (HIPS)
(Nippon Plastic Industry Co., Ltd., MFR 3.4 g / 10 min, Vicat softening point 96 ° C., PS sheet 0.5 mm thickness, Charpy impact strength 11 kJ / m ² )

(3) Haze According to ASTM1003, the haze (unit:%) of the inflation film (thickness 60 micrometers) shape | molded by the below-mentioned method was measured. The smaller the haze, the better the transparency.

(4) Internal haze Inflation film (thickness 60 μm) formed by the method described later is immersed in a transparent cell containing dimethyl phthalate, and the internal haze (unit:%) of the film in the immersed state 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 )
Inflation film (thickness 60 μm) formed by the method described later is cut into 10 cm × 10 cm, stacked so that the insides of the tubes at the time of forming the inflation film are in close contact with each other, and 400 g / cm in an oven adjusted to 40 ° C. ^The mixture was allowed to stand for 7 days under a load of ² . After standing, a Mackenzie blocking tester (manufactured by Shimadzu Corporation) was used to measure the amount of load necessary for peeling in the vertical direction at a peeling load rate of 20 g / min. The smaller this value, the better the anti-blocking property.

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

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

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

(9) Manufacture of master batch Component (A) and additive were melt kneaded at 160 ° C with a Banbury kneader at the ratio shown in Table 1, and then pelletized with a granulator to produce an additive master batch. .

(10) Surface Crystallization Index Infrared spectroscopic spectrum measurement was performed by the attenuated total reflection method [Attenuated Total Reflection (ATR) method] using the apparatus and measurement procedure described below.
・ Devices: Fourier exchange infrared spectrophotometer FT / IR-480, multiple reflection measurement device ATR-500M (all manufactured by JASCO), prism KRS-5 / 45 ° (manufactured by Sanyo Kagaku)
・ Measurement mode: Abs
・ Resolution: 4cm-1,
・ Number of integration: 32 times
ATR-IR measurement procedure: An infrared absorption spectrum was obtained by bringing the sealing layer on the film surface into contact with the upper and lower surfaces of the KRS-5 prism.
The absorbance Abs of the obtained infrared absorption spectrum was taken as the vertical axis, and 760-674 cm ⁻¹ was taken as the baseline. In the range of 725 cm ⁻¹ or more and 735 cm ⁻¹ or less of the obtained infrared absorption spectrum, the peak having the maximum height from the baseline was defined as D730. 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 formula.
Surface crystallization index = D730 / D720

(11) Phase contrast microscope observation With the seal layer on the film surface in contact with the adherend 2, the film is placed on 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. The obtained sample was cut in the thickness direction of the film in parallel with the heat seal width using a cryomicrotome (manufactured by LEICA) 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 the slide glass, and the test piece obtained was placed on the slide glass so that the cross section was on top. An image was obtained by measuring the observation surface with a phase contrast microscope of NIKON MICROPHOT FXA (Nikon Corp.). Using the images obtained, T ₀ and T ₁ were measured.
The thickness of the sealing layer on the film surface of the non-heat sealed part 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) it 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 in the thickness direction of the film 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 by a method defined in JIS K7206 under the condition of a load of 50N.

Example 1
[Co-extrusion blown film forming]
The inflation film was manufactured by the coextrusion inflation molding method so that the outer layer, the intermediate layer, and the inner layer were laminated in this order. As an outer layer resin composition and an intermediate layer resin composition, an ethylene polymer Sumikacene (registered trademark) E FV202 (manufactured by Sumitomo Chemical Co., Ltd., ethylene-1-hexene copolymer, MFR 2.0 g / 10 min, density) 925 kg / m ³ ) 80% by weight, ethylene polymer Sumikasen (registered trademark) F200 (manufactured by Sumitomo Chemical Co., Ltd., high pressure method low density polyethylene, MFR 2.0 g / 10 min, density 924 kg / m ³ ) 20% by weight A resin composition was used. As the resin composition for the inner layer, a resin composition containing PE1, OE1, TA1, and MB1 in the blending amounts shown in Table 2 was used.
The coextrusion inflation molding is performed by using a three-layer inflation film processing machine manufactured by Plako Co., Ltd., by processing at a die temperature of 170 ° C., a total extrusion amount of 30 kg / hour, a blow ratio of 2.0, and a take-up speed of 9.5 m / min. A coextruded 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 inflation film tube was subjected to corona discharge treatment so that the wetting tension was 45 dyn / cm. Table 3 shows the physical properties of the obtained inflation film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation film was 5% by weight.
[Laminate film forming]
Using a coater manufactured by Yasui Seiki Co., Ltd., “Takelac A-310” and “Takenate A-3” (both made by Mitsui Takeda Chemical Co., Ltd.), which are aliphatic ester coating agents, were mixed at the following blending 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 obtained polyester film was pressure-bonded to the corona-treated surface of the film obtained in the above example, and then heated in an oven at 40 ° C. for 48 hours to obtain a laminate film.
Takelac / Takenate / Ethyl acetate = 12/1/32 (weight ratio)
The heat seal strength was measured using a laminate film. The results are shown in Table 3. Table 4 shows D730 / D720 and T1 / T0 of the laminate 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 changed to the amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on methyl methacrylate contained in the inner layer of the inflation 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 amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of the monomer unit based on the unsaturated ester contained in the inner layer of the inflation 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 PE1, OE1 and MB1 were used in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 changed to the amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 changed to the amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. Table 4 shows D730 / D720 and T1 / T0 of the laminate film. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 blended in amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The sealing layer surface crystallization index of the laminate film is shown in Table 4. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation 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 changed to the amounts shown in Table 2. Table 3 shows the physical properties of the inflation film and the laminate film. The sealing layer surface crystallization index of the laminate film is shown in Table 4. The content of monomer units based on vinyl acetate contained in the inner layer of the inflation film was 4.8% by weight.

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

This patent application claims priority from Japanese Patent Application No. 2017-094501 (filing date: May 11, 2007), which is hereby incorporated by reference in its entirety. Shall be incorporated.

Claims

A film including a base material layer and a seal layer, and having a thickness of 20 μm to 150 μm,
One surface layer of the film is a base material layer, and another one surface layer is a seal layer,
The sealing layer includes a resin composition, and has a thickness of 5 μm or more and 100 μm or less,
The crystallization index [D730 / D720] of the surface of the sealing 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 seal layer on the film surface in contact with the following adherend (X), the film was heated to 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 sealed, the ratio of the thickness of the portion formed by elution and solidification of the resin composition of the seal layer from the heat seal portion to the non-heat seal portion and the thickness of the seal layer of the non-heat seal portion is 1.80 or more 2. A film that is 20 or less.
Substrate (X): Thickness of 350 μm or more consisting of impact-resistant polystyrene having a melt flow rate of 3.0 g / 10 min to 4.0 g / 10 min and a Vicat softening temperature of 95 ° C. to 100 ° C. Substrate to be 550 μm or less
[D730 / D720] is 0.680 or more and 0.750 or less, The film according to claim 1.
When heat sealing is performed 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, the resin composition of the sealing layer is eluted from the heat seal portion to the non-heat seal portion. The film according to claim 1 or 2, wherein the ratio between the thickness of the solidified portion and the thickness of the seal layer of the non-heat seal portion is 1.85 or more and 2.20 or less.
A lid comprising the film according to any one of claims 1 to 3.