JP2023142142A - Multilayer film, multilayer film for deep drawing, and deep-draw molded product - Google Patents

Abstract

To provide a multilayer film having tensile properties, impact resistance and pinhole resistance.SOLUTION: A multilayer film having at least two layers of a polyester-based resin layer (I) including polyester-based resin (Y) and a seal layer (II) satisfies conditions a) to c). a) the content of cobalt element by ICP emission spectrometry of polyester-based resin (Y) is 5 ppm or more, b) the content of phosphorus element by ICP emission spectrometry of polyester-based resin (Y) is 30 ppm or more, and c) the content of antimony element by ICP emission spectrometry of polyester-based resin (Y) is 220 ppm or less.SELECTED DRAWING: None

Description

The present invention provides a multilayer film that can be used to produce deep-drawn products, etc. and that can also contribute to reducing environmental impact, a deep-drawing film using this multilayer film, and furthermore, a film using the multilayer film. It relates to a deep drawn product.

A multilayer film with resin layers having various functions is deep-drawn to create a bottom material with a housing recess, and the stored items such as processed meat products such as hams and sausages, or medicines can be stored in the housing recess. Deep-drawn packaging is widely used, which is made by filling a film with a lid and heat-sealing it to a bottom material.

Conventionally, the bottom material of such deep-drawn packaging includes a sealing layer that provides heat-sealability with the lid material, an ethylene vinyl alcohol resin layer that provides gas barrier properties, and impact resistance and deep-drawability. Multilayer films are used that are formed by laminating resin layers having various functions, such as polyester resin layers and polyamide resin layers.

For example, Patent Document 1 discloses a multilayer film that includes a polyester layer that provides deep drawability.
Further, Patent Document 2 discloses a multilayer film including a laminate in which a first resin layer containing a thermoplastic resin and a second resin layer containing an adhesive resin are alternately laminated in eight or more layers, and a recovery layer. A multilayer film is disclosed in which the recovery layer is a resin layer containing film pieces discharged during multilayer film production as at least part of the resin raw material.

Japanese Patent Application Publication No. 2006-224470 Japanese Patent Application Publication No. 2016-087892

Towards the realization of the Sustainable Development Goals (SDGs), promoting the reuse of plastics is an essential issue in order to reduce the environmental burden. However, in order to use recycled plastics to produce new industrial products, especially to make multilayer films for deep-drawn packaging as mentioned above, it is necessary to improve the tensile properties, impact resistance and pinhole resistance. It was necessary to have characteristics for use in deep-drawn packaging.

Therefore, the present invention aims to provide a multilayer film having tensile properties, impact resistance, and pinhole resistance, a multilayer film for deep drawing, and a deep drawing product using the same.

In order to solve the above problems, the present invention proposes a multilayer film having the following configuration.

[1] The first aspect of the present invention is a multilayer film having at least two layers: a polyester resin layer (I) containing a polyester resin (Y) and a sealing layer (II), comprising the following a) It is a multilayer film that satisfies the conditions of ~c).
a) The content of cobalt element as determined by ICP emission analysis of the polyester resin (Y) is 5 ppm or more.
b) The content of elemental phosphorus as determined by ICP emission analysis of the polyester resin (Y) is 30 ppm or more.
c) The content of antimony element as determined by ICP emission analysis of the polyester resin (Y) is 220 ppm or less.

[2] A second aspect of the present invention is a multilayer film in which the polyester resin (Y) in the first aspect is a chemically recycled polyester resin.

[3] A third aspect of the present invention is that in the first or second aspect, the polyester resin (Y) is mainly a polyester condensation polymer containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a glycol component. This is a multilayer film that is a polyester resin obtained by depolymerizing the polyester resin composition (X) contained as a component resin, decomposing it into a dicarboxylic acid component and a glycol component, and condensing it again.
[4] A fourth aspect of the present invention is a multilayer film in which the polyester resin composition (X) in the third aspect is a packaging material.

[5] A fifth aspect of the present invention is a multilayer film according to any one of the first to fourth aspects, wherein the sealing layer (II) contains a polyolefin resin as a main component resin.

[6] In a sixth aspect of the present invention, in any one of the first to fifth aspects, an intermediate layer is provided as a barrier layer between the polyester resin layer (I) and the sealing layer (II). (III) is a multilayer film.
[7] A seventh aspect of the present invention is a multilayer film according to the sixth aspect, wherein the intermediate layer (III) contains a polyamide resin and/or a polyvinyl alcohol resin as a main resin.

[8] An eighth aspect of the present invention is the multilayer film according to any one of the first to seventh aspects, having a thickness of 100 to 500 μm.

[9] A ninth aspect of the present invention is a multilayer film according to any one of the first to eighth aspects, wherein the layer thickness of the polyester resin layer (I) accounts for 50% or more of the total thickness of the multilayer film. It is.

[10] A tenth aspect of the present invention is a multilayer film for deep drawing using the multilayer film of any one of the first to ninth aspects.
[11] An eleventh aspect of the present invention is a deep-drawn product using the multilayer film for deep-drawing according to the tenth aspect.

The multilayer film proposed by the present invention can have better tensile properties, impact resistance, and pinhole resistance than conventional multilayer films using polyester resins, and can be suitably used for deep drawing. can.

Embodiments of the present invention will be described in detail below. However, the content of the present invention is not limited to the embodiments described below.

<<Multilayer film>>
A multilayer film according to an example of an embodiment of the present invention (referred to as "this multilayer film") is a multilayer film having at least two layers: a polyester resin layer (I) and a sealing layer (II).

<Polyester resin layer (I)>
The polyester resin layer (I) preferably contains a polyester resin (Y), and more preferably contains a polyester resin (Y) as a main component resin.
Here, the main component resin of each layer means the resin with the highest mass percentage among the resin components constituting each layer. For example, out of 100 mass% of the resin components constituting each layer, 50% by mass or more, especially 60% by mass It is possible to envisage resins accounting for at least 70% by weight, especially at least 80% by weight, especially at least 90% by weight, especially at least 100% by weight. The same applies to the main component resins of other layers.

(Polyester resin (Y))
It is preferable that the polyester resin (Y) is a chemically recycled polyester resin.
The chemically recycled polyester resin means a polyester resin obtained by chemically recycling a polyester resin composition (X) containing a polyester resin. That is, it is a polyester resin obtained by depolymerizing the polyester resin composition (X) to decompose it into a dicarboxylic acid component and a glycol component, and then polycondensing it again.

[Polyester resin composition (X)]
The polyester resin composition (X) may be a composition containing as a main resin a polyester condensation polymer a containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a glycol component.
Here, the main component resin of each composition means the resin with the highest mass percentage among the resin components constituting each composition, for example, 50% of the 100% by mass of the resin components constituting each composition. It is possible to envisage resins accounting for at least 60% by weight, especially at least 70% by weight, especially at least 80% by weight, especially at least 90% by weight, especially at least 100% by weight. The same applies to the main component resins of other compositions.

The polyester condensation polymer a may further contain a dicarboxylic acid component other than terephthalic acid.
Examples of dicarboxylic acid components other than terephthalic acid components include isophthalic acid, orthophthalic acid, 1,5-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and biphenyl-2,2'-dicarboxylic acid. acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, benzophenone dicarboxylic acid, anthracene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid Aromatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4'-dicyclohexyldicarboxylic acid, alicyclic dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, azelaic acid, dimer acid, etc. Examples include aliphatic dicarboxylic acids such as hexahydroterephthalic acid, 1,3-adamantanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 2,6-naphthalene dicarboxylic acid.

The polyester condensation polymer a may further contain a glycol component other than ethylene glycol.
Examples of glycol components other than ethylene glycol include chlorohydroquinone, methylhydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxybenzophenone, Aromatic diols such as p-xylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, etc. Examples include aliphatic and alicyclic diols such as , 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol.

It is preferable that the polyester resin composition (X) is already commercialized. Examples include various molded articles such as clothing, films, and containers that contain the polyester condensation polymer a as a main resin. Among these, packaging materials such as packaging containers, packaging bags, and packaging films are preferred.
Examples of packaging materials include film-like materials, molded products, containers, and crushed and cut products thereof. The history of the packaging material is not particularly limited. For example, the packaging material may have any history as long as it is a product distributed on the market, an unused product, an intermediately processed product, a leftover product, a defective product, a prototype product, a discarded product, or the like. A typical example is a waste plastic bottle.
The packaging material may be a mixture of packaging materials that differ in printing ink, color, design, and constituent resin composition, or may be packaging materials of the same type.

[Chemical recycling]
In order to chemically recycle the polyester resin composition (X) to obtain the polyester resin (Y), for example, the polyester resin composition (X) is depolymerized using an alkali or the like to decompose it to the molecular level. Then, it may be decomposed into a dicarboxylic acid component and a glycol component, and then polycondensed again.

As a specific example of a method for chemically recycling the polyester resin composition (X), the following method can be mentioned, for example. However, the method is not limited to this method.
The polyester resin composition (X) is depolymerized to obtain a depolymerization liquid (liquid depolymerization product) containing bis-(2-hydroxyethyl) terephthalate (BHET), and impurities are removed from the depolymerization liquid. , a method of concentrating to recover bis-(2-hydroxyethyl) terephthalate (BHET), and using this BHET to perform polycondensation to produce recycled PET.

As a method for depolymerizing the polyester resin composition (X), for example, the polyester resin composition (X), monoethylene glycol (MEG), and a depolymerization catalyst are mixed, and the mixture is heated under a predetermined temperature and pressure. By causing the reaction to occur, the polyester resin composition (X) can be depolymerized.
Examples of depolymerization catalysts include alkali metal hydroxides, alkali metal carbonates, alkali metal fatty acid salts, alkali metal alkoxides, alkaline earth metal hydroxides, alkaline earth metal carbonates, and alkali metals. Examples include earth metal fatty acid salts, alkaline earth metal alkoxides, alkaline earth metal oxides, transition metal hydroxides, transition metal carbonates, transition metal fatty acid salts, transition metal alkoxides, etc. can.
The temperature during depolymerization is preferably about 180 to 210°C, the time during depolymerization is preferably about 1 to 10 hours, and the atmospheric pressure during depolymerization is 60 kPa to 160 kPa. It is preferable that the amount is within a certain range.

Since the depolymerization liquid obtained by depolymerization contains unnecessary substances, it is preferable to remove them by filtration with a filter or the like.
Further, it is preferable to decompose and remove dyes and the like using a dye decomposing agent. Specifically, the dye can be oxidatively decomposed by adding a dye decomposing agent containing at least one of ozone, hydrogen peroxide, concentrated sulfuric acid, an oxygen-based oxidizing agent, and a chlorine-based oxidizing agent. Then, the depolymerization liquid is cooled to 20 to 25°C to precipitate fine crystals of BHET and polyester oligomer as a solid content, and then, using a centrifugal sedimentation centrifuge, the precipitated solid content and the depolymerization liquid are separated. Solid-liquid separation can be performed between the MEG contained therein and the dye decomposition product dissolved in the MEG.

Next, the above solid substance is melted by heating to obtain a liquid depolymerized product (depolymerized liquid) in a molten state, and low-boiling components having a boiling point lower than that of BHET are removed from this depolymerized liquid to obtain BHET. And crude BHET containing polyester oligomer as the main resin can be obtained. Examples of low boiling point components include mainly MEG and diethylene glycol (DEG).
At this time, the removal (evaporation/distillation) of the low-boiling components can be performed using, for example, various evaporators. In particular, in order to prevent polymerization of BHET and polyester oligomer during the evaporation operation, it is preferable to carry out the evaporation operation by setting the temperature of the crude BHET concentrate to 130° C. or lower under reduced pressure. Further, it is preferable to select an evaporator having a structure (model) such that the residence time of the crude BHET concentrate in the evaporator is 10 minutes or less. Specific examples of the evaporator include a falling film evaporator and a thin film evaporator.

The BHET is then recovered from the crude BHET concentrate by distillation, preferably under vacuum.

BHET obtained in a molten state may be directly polycondensed (melt polycondensation) to produce recycled polyethylene terephthalate (recycled PET), or BHET obtained in a molten state may be once granulated and then subjected to polycondensation (melt polycondensation). (polycondensation) to produce recycled PET.

When producing recycled PET by polycondensation, recycled PET can be easily produced by mixing BHET and terephthalic acid in an arbitrary ratio. In this case, in order to contribute to the construction of a sustainable closed loop recycling, it is preferable that the recycled PET contains a structure derived from BHET in an amount of 50% by mass or more, preferably 65% by mass or more, and 80% by mass or more. It is even more preferable to contain it.

As mentioned above, by producing bis-(2-hydroxyethyl) terephthalate (BHET) and polycondensing it using this BHET to produce chemically recycled PET, impurities can be reduced and purity can be improved. Highly chemically recycled PET can be obtained. For example, it is possible to reduce by-products (diethylene glycol-derived products, etc.) generated during polycondensation of polyester, and it is possible to improve the mechanical properties of the film.

[Composition of polyester resin (Y)]
The polyester resin (Y) is preferably a polyester condensation polymer containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a glycol component.

The polyester resin (Y) may further contain dicarboxylic acid components other than terephthalic acid.
Examples of dicarboxylic acid components other than terephthalic acid components include isophthalic acid, orthophthalic acid, 1,5-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and biphenyl-2,2'-dicarboxylic acid. acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'-carboxyphenyl)methane, benzophenone dicarboxylic acid, anthracene dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid Aromatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 4,4'-dicyclohexyldicarboxylic acid, alicyclic dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, azelaic acid, dimer acid, etc. Examples include aliphatic dicarboxylic acids such as hexahydroterephthalic acid, 1,3-adamantanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 2,6-naphthalene dicarboxylic acid.

The polyester resin (Y) preferably contains terephthalic acid in a proportion of 75 mol% or more and 100 mol% or less in 100 mol% of the total dicarboxylic acid components, with the lower limit being 80 mol% or more, among which 85 mol%. It is preferable to include it in the above proportion.
On the other hand, the polyester resin (Y) preferably contains isophthalic acid in a proportion of 0 mol% or more and 1.3 mol% or less in 100 mol% of the total dicarboxylic acid components, and the upper limit is 1.1 mol% or less. Among them, it is preferably contained in a proportion of 1.0 mol% or less.

The polyester resin (Y) may further contain a glycol component other than ethylene glycol.
Examples of glycol components other than ethylene glycol include chlorohydroquinone, methylhydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxybenzophenone, Aromatic diols such as p-xylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, etc. Examples include aliphatic and alicyclic diols such as , 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol.

The polyester resin (Y) preferably contains ethylene glycol in a proportion of 75 mol% or more and 100 mol% or less in 100 mol% of the total glycol components, with the lower limit being 80 mol% or more, among which 85 mol% or more. It is preferable to include it in a proportion of .
On the other hand, the polyester resin (Y) preferably contains diethylene glycol in a proportion of 0 mol% or more and 1.5 mol% or less, with the upper limit being 1.4 mol% or less, based on 100 mol% of the total dicarboxylic acid components. Among these, it is preferably contained in a proportion of 1.2 mol% or less, particularly 1 mol% or less, and particularly 0.8 mol% or less.

[Physical properties of polyester resin (Y)])
The polyester resin (Y) preferably has a cobalt element content of 5 ppm or more according to ICP emission analysis, from the viewpoint of preventing yellowing due to thermal deterioration and maintaining the color tone during production of the present multilayer film, and preferably 10 ppm or more. It is more preferably at least 20 ppm, even more preferably at least 30 ppm, and particularly preferably at least 30 ppm. On the other hand, from the viewpoint of maintaining physical properties, the content is preferably 200 ppm or less, more preferably 150 ppm or less, and even more preferably 100 ppm or less.

In order to prevent quality deterioration due to thermal deterioration during production of the multilayer film, the polyester resin (Y) preferably has a phosphorus element content of 30 ppm or more, more preferably 35 ppm or more, as measured by ICP emission analysis. The content is preferably 40 ppm or more, and more preferably 40 ppm or more. On the other hand, from the viewpoint of maintaining physical properties, the content is preferably 200 ppm or less, more preferably 150 ppm or less, and even more preferably 100 ppm or less.

The content of antimony element in the polyester resin (Y) according to ICP emission analysis is preferably 220 ppm or less, more preferably 200 ppm or less, in order to prevent quality deterioration due to thermal deterioration during production of the multilayer film. It is preferably 190 ppm or less, even more preferably 180 ppm or less. The lower limit is not particularly limited, but is usually 75 ppm or more.
Note that the contents of cobalt, phosphorus, and antimony may be measured under the conditions described in the examples.

The intrinsic viscosity (IV) of the polyester resin (Y) is preferably 0.5 dl/g or more and 1.1 dl/g or less, from the viewpoint of improving the tensile properties, impact resistance, and pinhole resistance of the present multilayer film. It is more preferably 0.6 dl/g or more or 1.0 dl/g or less, and even more preferably 0.65 dl/g or more and 0.9 dl/g or less.
If the intrinsic viscosity (IV) of the polyester resin (Y) is within the above range, stable melt extrusion and multilayer film formation can be performed. Note that the intrinsic viscosity may be measured under the conditions described in the examples.

The storage modulus E' (5°C) of the polyester resin (Y) measured by the tensile method at a vibration frequency of 10Hz and 5°C is from the point of improving the tensile properties, impact resistance, and pinhole resistance of this multilayer film. , is preferably 1,850 MPa or more and 2,300 MPa or less, more preferably 1,900 MPa or more or 2,200 MPa or less, even more preferably 1,950 MPa or more and 2,180 MPa or less, particularly preferably 1,980 MPa or more and 2,140 MPa or less.
By setting the storage modulus E' (5°C) of the polyester resin (Y) within the above range, pinholes tend to be less likely to occur even when the contents are packaged and stored at low temperatures, such as refrigerated storage. .

The storage modulus E' (23°C) of the polyester resin (Y) measured by the tensile method at a vibration frequency of 10Hz and 23°C is from the point of view of improving the tensile properties, impact resistance and pinhole resistance of this multilayer film. , is preferably 1,700 MPa or more and 2,120 MPa or less, more preferably 1,750 MPa or more or 2,080 MPa or less, even more preferably 1,800 MPa or more and 2,040 MPa or less, particularly preferably 1,850 MPa or more and 2,000 MPa or less.
By setting the storage modulus E' (23°C) of the polyester resin (Y) within the above range, the contents tend to be less prone to breakage and pinholes, even when the contents are packaged and are subjected to impact, for example, during transportation. .

The storage modulus E' (100°C) of the polyester resin (Y) measured by the tensile method at a vibration frequency of 10Hz and 100°C is determined from the viewpoint of improving the tensile properties, impact resistance, and pinhole resistance of this multilayer film. , is preferably 5 MPa or more and 20 MPa or less, more preferably 6 MPa or more or 17 MPa or less, particularly preferably 8 MPa or more and 15 MPa or less.
By setting the storage elastic modulus E' (100°C) of the polyester resin (Y) within the above range, it is possible to impart appropriate formability and rigidity during deep drawing, and to prevent localized unevenness due to forming irregularities. This can prevent thinning of the film.
Note that the storage modulus E' may be measured under the conditions described in the examples.

The crystallization energy (ΔHc) of the polyester resin (Y) is preferably 18 J/g or more and 40 J/g or less, from the viewpoint of improving the tensile properties, impact resistance, and pinhole resistance of the present multilayer film. It is more preferably 20 J/g or more and 36 J/g or less, and particularly preferably 22 J/g or more and 32 J/g or less.
By setting the crystallization energy (ΔHc) of the polyester resin (Y) within the above range, the crystallinity becomes appropriate when formed into a film, and it tends to be easier to achieve both mechanical strength and transparency.
Note that the crystallization energy (ΔHc) may be measured under the conditions described in the examples.

(Component composition of polyester resin layer (I))
The content ratio of the polyester resin (Y) in the polyester resin layer (I) is preferably 50% by mass to 100% by mass, with the lower limit being 60% by mass or more, particularly 70% by mass or more, The higher the content ratio, the more preferable.

The polyester resin layer (I) may contain resin other than the polyester resin (Y). The other resins are preferably thermoplastic resins, and include polyester resins, polyolefin resins, polystyrene resins, polycarbonate resins, and the like. From the viewpoint of compatibility and the like, polyester resin is more preferable. Examples include aliphatic polyester resins such as polylactic acid resins and polybutylene succinate resins, aromatic polyester resins, and the like. However, it is not limited to these.

Further, the polyester resin layer (I) may contain other components other than the resin component within a range that does not impair the effects of the present invention. Examples of other components include antistatic agents, antifogging agents, antiblocking agents, slip agents, colorants, and pigments. However, it is not limited to these.

(Laminated structure of polyester resin layer (I))
The polyester resin layer (I) may be composed of a single layer or a plurality of layers of two or more types.

(Thickness of polyester resin layer (I))
The thickness of the polyester resin layer (I) is preferably 10 μm or more and 600 μm or less, and more preferably 100 μm or more or 500 μm or less.
By setting the thickness of the polyester resin layer (I) within the above range, film forming stability, impact resistance, pinhole resistance, and deep drawing formability can be imparted to the present multilayer film.

The layer thickness of the polyester resin layer (I) (total thickness if it consists of two or more layers) is determined from the viewpoint of increasing the recycling rate of the multilayer film and contributing to reducing the environmental load, as well as from the viewpoint of the tensile properties and durability of the multilayer film. From the viewpoint of impact resistance, pinhole resistance, etc., it is preferable that it accounts for 50% or more of the total thickness of the present multilayer film, especially 55% or more, and even more preferably 60% or more. On the other hand, from the viewpoint of flexibility, barrier properties, sealing properties, etc. due to other functional layers, the thickness of the multilayer film is preferably 90% or less, especially 85% or less, and 80% or less of the total thickness of the multilayer film. More preferred.

<Seal layer (II)>
The sealing layer (II) of the present multilayer film is a layer that constitutes the outermost layer on both the front and back sides. When a molded container is formed from this multilayer film, this layer becomes the innermost layer of the container and comes into contact with the contents. Moreover, it is a layer that has sealing properties and can also function as a heat-sealing layer. Therefore, for example, when a bottom material having a housing recess is produced by deep drawing the present multilayer film, the sealing layer (II) of the bottom material can be brought into contact with the lid material and heat-sealed.

(Polyolefin resin)
From the viewpoint of heat-sealability, the sealing layer (II) preferably contains a polyolefin resin as a main component resin.

Examples of the polyolefin resin used for the sealing layer include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ethylene-acrylic acid copolymer (EAA), and ethylene-methyl acrylate copolymer (EMA). ), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ionomer resin, vinyl acetate content of 8 mol% or more 40 Examples include ethylene-vinyl acetate copolymer (EVA) of mol % or less, hot melt resin (HM), and resins obtained by modifying these polyolefin resins. These may be used alone or in combination of two or more.
These polyolefin resins are preferably selected appropriately depending on the shape of the molded article, the shape and type of the contents. Further, the polyolefin resin may be blended in a known formulation in order to impart easy peelability. An example of a known formulation for imparting the easy-peel properties is a mixture of low-density polyethylene and polybutene resin.

The melting point of the polyolefin resin is preferably 100°C or higher and 175°C or lower, more preferably 110°C or higher or 170°C or lower, and even more preferably 115°C or higher or 168°C or lower.
When the melting point of the polyolefin resin is within the above range, more excellent heat sealability can be imparted.
Note that the melting point may be measured under the conditions described in the examples.

The thickness of the sealing layer (II) is preferably 1 μm or more and 100 μm or less, more preferably 2 μm or more or 80 μm or less, and even more preferably 5 μm or more and 60 μm or less.
By setting the thickness of the sealing layer (II) within the above range, film formation stability and sufficient sealing properties can be imparted.

<Intermediate layer (III)>
The present multilayer film may include an intermediate layer (III) between the polyester resin layer (I) and the seal layer (II).

The intermediate layer (III) is preferably a layer that functions as a barrier layer capable of exhibiting gas barrier properties such as oxygen barrier properties and water vapor barrier properties.

From the viewpoint of having barrier properties as described above, the intermediate layer (III) is preferably a layer containing a polyamide resin, a polyvinyl alcohol resin, or a mixed resin thereof as a main resin.
By containing the polyamide resin, the intermediate layer (III) can improve the barrier properties and pinhole resistance of the present multilayer film. Further, by including the polyvinyl alcohol resin in the intermediate layer (III), the gas barrier properties, for example, the oxygen barrier properties, of the present multilayer film can be improved.

The intermediate layer (III) may contain other resins than polyamide resin and polyvinyl alcohol resin.

The intermediate layer may be composed of a single layer or may be composed of two or more layers. For example, even if it consists of a single layer containing polyamide resin and/or polyvinyl alcohol resin as the main resin, it may consist of multiple layers containing polyamide resin and/or polyvinyl alcohol resin as the main resin. It may be. For example, it may be composed of a plurality of layers including a layer containing polyamide resin as the main component resin and a layer containing polyvinyl alcohol resin as the main component resin.

[Polyamide resin]
Examples of the polyamide resin used in the intermediate layer include polyamide 4, polyamide 6, polyamide 7, polyamide 11, polyamide 12, polyamide 46, polyamide 66, polyamide 69, polyamide 610, polyamide 611, polyamide 6T, polyamide 6I, and polyamide. MXD6, polyamide 6-66, polyamide 6-610, polyamide 6-611, polyamide 6-12, polyamide 6-612, polyamide 6-6T, polyamide 6-6I, polyamide 6-66-610, polyamide 6-66-12 , polyamide 6-66-612, polyamide 66-6T, polyamide 66-6I, polyamide 6T-6I, polyamide 66-6T-6I, and the like.
Among these, polyamide 6 and polyamide 6-66 are preferably used from the viewpoint of pinhole resistance. Further, two or more intermediate layers may be provided, and in that case, each layer may be formed of a different type of polyamide resin.

When the intermediate layer contains a polyamide resin, the total thickness of the intermediate layers disposed in the multilayer film, including the case where two or more layers are disposed, is preferably 1% or more with respect to the total thickness of the film, and the lower limit is 1% or more. .5% or more is more preferable. Further, the upper limit is preferably 70% or less, more preferably 60% or less.
By setting the thickness ratio of the intermediate layer to 1% or more, sufficient pinhole resistance can be imparted to the film, and by setting the upper limit to 70% or less, flexibility can be maintained.

[Polyvinyl alcohol resin]
The polyvinyl alcohol resin (hereinafter sometimes referred to as "EVOH") used in the intermediate layer is preferably a polyvinyl alcohol resin having a primary hydroxyl group in a side chain.
A polyvinyl alcohol resin having a primary hydroxyl group in the side chain is a resin mainly composed of vinyl alcohol structural units, and includes a vinyl alcohol structural unit equivalent to the degree of saponification, a vinyl acetate structural unit in the unsaponified portion, and a primary hydroxyl group in the side chain. It has at least a structural unit having a hydroxyl group.

The saponification degree (measured according to JIS K6726:1994) of the polyvinyl alcohol resin having a primary hydroxyl group in the side chain is preferably 60 to 100 mol%.
The degree of saponification of the polyvinyl alcohol resin is preferably 90 mol% or more from the viewpoint of thermal stability, more preferably 95 mol% or more from the viewpoint of gas barrier properties, and even more preferably 99 mol% or more.
By keeping the ethylene content and degree of saponification in the polyvinyl alcohol resin within the above ranges, good gas barrier properties can be maintained. Note that EVOH is not limited to those produced by saponification, as long as they have the same chemical structure.

The melting point of the polyvinyl alcohol resin is not particularly limited. For example, from the point of view of deep drawability, the temperature is preferably 150°C or higher and 210°C or lower, more preferably 152°C or higher or 205°C or lower, and among these, 155°C or higher or 200°C or lower. More preferred.

<Adhesive layer (IV)>
In addition to the above-mentioned polyester resin layer (I), sealing layer (II), and intermediate layer (III), this multilayer film is provided with an adhesive layer (IV) for the purpose of improving the adhesion between each layer. Good too. For example, an adhesive layer (IV) is provided between the polyester resin layer (I) and the intermediate layer (III), between the intermediate layer (III) and the sealing layer (II), or between both. It's okay.

The adhesive layer (IV) is preferably formed from a resin composition containing an adhesive resin as a main component resin.
Here, examples of the adhesive resin include polyethylene resins such as low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene, polypropylene resins, ethylene-vinyl acetate copolymers, and ethylene-acrylic acid copolymers. Polymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer, ethylene Examples include ethylene copolymer resins such as ionomers; other modified polyolefin resins, such as ethylene-vinyl acetate copolymers or ethylene elastomers, monobasic unsaturated fatty acids such as acrylic acid or methacrylic acid; Alternatively, examples include chemically bonded anhydrides of dibasic fatty acids such as maleic acid, fumaric acid, or itaconic acid. Among these, when providing between the seal layer and the intermediate layer, it is preferable to use a polyethylene-based adhesive resin from the viewpoint of adhesion to the seal layer. However, the adhesive resin may be used alone or in combination of two or more.

The thickness of the adhesive layer (IV) (total thickness in the case of multiple layers) is preferably 3 μm or more and 30 μm or less, more preferably 4 μm or more or 25 μm or less, and particularly preferably 5 μm or more or 20 μm or less. By setting the thickness of the adhesive layer (IV) within the above range, film formation stability and sufficient adhesiveness can be imparted.

<Other layers>
This multilayer film may be provided with layers other than those described above, if necessary.
For example, a resin composition layer containing a polyolefin resin as a main component resin may be provided in order to improve the film strength and heat resistance or adjust the thickness. The resin composition layer may be provided, for example, between the intermediate layer (III) and the seal layer (II).

When containing polyolefin resin as the main component resin of other layers, polyolefin resins such as those exemplified for sealing layer (II) can be used, and the polyolefin resins can be used alone or in combination of two or more types. You can. Further, it may be the same as or different from the polyolefin resin used in the sealing layer (II).

The thicknesses of the other layers are not particularly limited, and may be appropriately set depending on the purpose and the like. It is usually 3 μm or more and 30 μm or less, preferably 4 μm or more or 25 μm or less, and particularly preferably 5 μm or more and 20 μm or less.
By setting the thickness of the other layers within the above range, the film forming stability of the present multilayer film can be improved.

<Example of layer structure of multilayer film>
The following examples can be given as examples of the layer structure of the present multilayer film. However, it is not limited to these examples.

(1) Polyester resin layer (I)/seal layer (II)
(2) Polyester resin layer (I)/intermediate layer (III)/seal layer (II)
(3) Polyester resin layer (I)/adhesive layer (IV)/intermediate layer (III)/seal layer (II)
(4) Polyester resin layer (I)/intermediate layer (III)/adhesive layer (IV)/seal layer (II)
(5) Polyester resin layer (I) / adhesive layer (IV) / intermediate layer (III) / adhesive layer (IV) / sealing layer (II)
(6) Polyester resin layer (I) / adhesive layer (IV) / intermediate layer (III) / adhesive layer (IV) / other layers / sealing layer (II)
(7) Polyester resin layer (I)/other layers/adhesive layer (IV)/intermediate layer (III)/adhesive layer (IV)/sealing layer (II)

In each of the above configurations, it is also possible to provide an outermost layer on the outside of the polyester resin layer (I). For example, in order to improve the feel and appearance, it is also possible to provide a surface layer containing copolymerized polyester (for example, PETG) as the main resin.

<Other additives>
Each layer constituting this multilayer film contains pigments, antioxidants, and electrostatic charges for the purpose of improving and adjusting various properties such as moldability, productivity, design, etc., within a range that does not significantly impair the effects of the present invention. Additives such as inhibitors, melt viscosity modifiers, crosslinking agents, lubricants, nucleating agents, plasticizers, etc. can be appropriately added to the required layers.

<Method for manufacturing multilayer film>
This multilayer film can be manufactured by using a resin composition forming each layer by a known method, such as an extrusion lamination method, a coextrusion inflation method, a coextrusion T-die method, or the like. In particular, it is preferable to use the coextrusion T-die method because the film forming process remains the same even when the number of film layers is large and the thickness can be controlled relatively easily.

This multilayer film may be an unstretched film or a stretched film. When used for deep drawing, it is usually not stretched.

As a more specific example, first, a polyester resin composition (X) containing as a main resin a polyester condensation polymer containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a glycol component is chemically recycled. A polyester resin (Y) is obtained.
Next, a resin composition containing a polyester resin (Y) as a main component resin and a resin composition containing a polyolefin resin as a main component resin are coextruded, for example, by a coextrusion T-die method, and the polyester resin is A multilayer film comprising layer (I) and sealing layer (II) can be obtained.

<Physical properties of multilayer film>
The tensile strength of the present multilayer film at a temperature of 23° C., measured in accordance with JIS K7127 (1999), is preferably 80.0 MPa or more in both MD and TD. Further, the tensile elongation in both MD and TD is preferably 1000% or more, more preferably 1020% or more, and even more preferably 1030% or more.
By setting the tensile strength and tensile elongation at 23° C. within the above ranges, the contents tend to be less prone to breakage and pinholes even when the contents are packaged and are subjected to impact during transportation, for example.

The tensile strength of the present multilayer film at a temperature of 5° C., measured in accordance with JIS K7127 (1999), is preferably 60.0 MPa or more in both MD and TD. Further, the tensile elongation in both MD and TD is preferably 500% or more, more preferably 530% or more.
By setting the tensile strength and tensile elongation at 5° C. within the above ranges, the contents tend to be less prone to breakage and pinholes even when the contents are packaged and, for example, are subjected to impact during transportation.

The puncture energy of the present multilayer film measured by a hydroshot high-speed tester at 23° C. based on JIS K7124-2 (1999) is preferably 2.0 J or more, more preferably 2.5 J or more. Further, the amount of puncture displacement (elongation) is preferably 11 mm or more, more preferably 15 mm or more.
By setting the puncture energy and the amount of puncture displacement at 23° C. within the above ranges, the contents tend to be less likely to break or pinhole, even when the contents are packaged and are subjected to impact, for example, during transportation.

The puncture energy of the multilayer film measured by a hydroshot high-speed tester at 5° C. according to JIS K7124-2 (1999) is preferably 1.50 J or more, more preferably 1.80 J or more. Further, the amount of puncture displacement (elongation) is preferably 10 mm or more, more preferably 11 mm or more.
By setting the puncture energy and puncture displacement at 5° C. within the above ranges, pinholes tend to be less likely to occur even when the contents are packaged and stored at low temperatures, such as refrigerated storage.

The puncture strength of the present multilayer film at 23° C. measured based on JIS Z1707 (2019) is preferably 20.0 J or more, more preferably 24.0 J or more.
By setting the puncture strength at 23° C. within the above range, there is a tendency that breakage and pinholes are less likely to occur even when the contents are packaged and are subjected to impact, for example, during transportation.

The puncture strength of the present multilayer film at 5° C. measured based on JIS Z1707 (2019) is preferably 30.0 J or more, more preferably 31.5 J or more.
By setting the puncture strength at 5°C within the above range, pinholes tend to be less likely to occur even when the contents are packaged and stored at low temperatures, such as refrigerated storage.

<Applications of this multilayer film>
The present multilayer film is suitable for making deep drawn packaging as described above. In addition, it is also suitable for producing various packages such as pouch packages, pillow packages, and vacuum packages. Among these, deep-drawn packaging is preferred, and particularly preferred is a deep-drawn packaging using the above-mentioned deep-drawn packaging film as a bottom material.

When producing a deep-drawn package from the multilayer film, the multilayer film is preferably produced without stretching in order to improve formability during drawing. For pouch packaging, pillow packaging, and vacuum packaging, after manufacturing without stretching, for example, stretched films such as biaxially stretched polypropylene films are laminated using a dry lamination method from the viewpoint of imparting strength and gas barrier properties. It is preferable to do so.

<Explanation of terms>
In the present invention, the term "film" includes everything from thick sheets to thin films.
In the present invention, when "X to Y" (X and Y are arbitrary numbers) means "more than or equal to X and less than or equal to Y," unless otherwise specified, "preferably greater than X" and "preferably Y It includes the meaning of "less than".
Furthermore, when it is written as "more than or equal to X" (X is any number), it includes the meaning of "preferably larger than X" unless otherwise specified, and when it is written as "less than or equal to Y" (where Y is any number) In this case, unless otherwise specified, it also includes the meaning of "preferably smaller than Y".

Even if the upper and lower limits of the numerical range specified by the present invention slightly deviate from the numerical range specified by the present invention, the present invention will still apply as long as it has the same effect as within the numerical range. shall be included in the equivalent range.

In the present invention, the term "main component resin" means a resin component that accounts for the largest percentage by mass of the resin components contained in the object. Regarding the content of the main component resin, when the content of the resin component contained in the object is 100% by mass, if the mass occupied by that component is 50% by mass or more, if it is 60% by mass or more, 70% by mass % or more, 80% by mass or more, 90% by mass or more, and 100% by mass.

Hereinafter, the present invention will be described in more detail based on Examples carried out in order to clarify the effects of the present invention. Note that the present invention is not limited in any way by the following Examples and Comparative Examples.

The raw materials used for the polyester resin layer, seal layer, intermediate layer, and other layers (adhesive layer, etc.) are shown below.

PETG: SKYGREEN S2008 (manufactured by SK Chemical, polyester resin copolymerized with 32 mol% of 1,4-cyclohexanedimethanol as a glycol component)

PET1: Using waste PET bottles as a starting material, depolymerize to obtain a depolymerization solution containing bis-(2-hydroxyethyl) terephthalate (BHET), remove impurities from the depolymerization solution, and concentrate to obtain bis-( Chemical recycled PET obtained by recovering 2-hydroxyethyl) terephthalate (BHET) and polycondensing it using this BHET.
PET2: RAMAPET N1 (manufactured by INDORAMA, polyester resin)

PE1: Novatec LD LF580 (manufactured by Japan Polyethylene Co., Ltd., low density polyethylene resin), melting point 116°C
PE2: Admer NF567 (manufactured by Mitsui Chemicals, PE adhesive resin)
PE3: Admer SF719 (manufactured by Mitsui Chemicals, PE adhesive resin)
PE4: Neozex 2512F (manufactured by Japan Polyethylene Co., Ltd., PE adhesive resin)

MB: Low density polyethylene resin (anti-fog masterbatch, containing 5% by mass of higher fatty acid glycenol)
PA: UBE1022B (manufactured by Ube Industries, polyamide 6)
EVOH: Soarnol SG929B (manufactured by Mitsubishi Chemical Corporation, polyvinyl alcohol resin, ethylene content 32 mol%), melting point 183°C

The glass transition temperature, crystallization temperature, crystallization energy, melting point, storage modulus E', composition, intrinsic viscosity IV, and content of PET1 and PET2 were measured by the following methods. The physical properties of PET1 and PET2 are shown in Table 1 below.

(melting point and glass transition temperature)
In accordance with JIS K7121 (2012), each raw material was heated at a rate of 10°C/min using a differential scanning calorimeter (manufactured by PerkinElmer, "DSC8000") to determine glass transition temperature (Tg), melting point ( Tm) was lowered at a rate of 10° C./min, and the crystallization temperature (Tc) and crystallization energy (ΔHc) were measured.

(Storage modulus E')
In accordance with JIS K7244-10 (2005), rheometer (TA
The storage modulus E' was measured at 5° C., 23° C., and 100° C. using a tensile method at a vibration frequency of 10 Hz using “Discovery HR2” (manufactured by Instruments Inc.).

(composition)
Fourier transform infrared absorption (FT-IR) was measured using an infrared absorption spectrometry (IR) device (Nicolet is5, manufactured by Thermo Scientific) using the total reflection measurement (ATR) method, 8 integrations, and a resolution of 4 cm. ) spectrum was obtained. In addition, ¹ H-NMR was obtained using a nuclear magnetic resonance (NMR) device (Avance 400M manufactured by Bruker) at a measurement temperature of 30°C. From the above FT-IR spectrum and ¹ H = NMR spectrum, the polyester raw material We analyzed the composition of

(Intrinsic viscosity IV)
In accordance with JIS K7367-5 (2000), 0.3 g of PET raw material was dissolved in 30 mL of phenol/1,1,2,2-tetrachloroethane = 50/50 solvent, and a fully automatic viscosity measuring device (manufactured by Rigosha, Intrinsic viscosity IV was measured at a temperature of 30° C. using “VMS-022UPC・F10”.

(density)
Density (g/cm ³ ) was measured using a density gradient tube (MODEL A manufactured by Shibayama Chemical Co., Ltd.) in accordance with JIS K7112-D method (1999).

(Contains)
In accordance with JIS K0116 (2014), add 10.0 mL of nitric acid to 0.10 g of sample, dissolve it using ultrasound, dilute to 50.0 mL using a 50 mL graduated cylinder, and perform high-frequency inductively coupled plasma emission. The type and amount of substances contained in the sample were measured using a spectroscopic analysis method (ICP emission spectrometry).

<Example 1 and Comparative Example 1>
A resin composition for forming each layer was prepared with the composition shown in Table 2 below, each resin composition was put into a separate twin screw extruder, and each resin composition was melt-kneaded at 220 ° C. The amount of molten resin discharged was adjusted so that each layer had a predetermined thickness, and each layer was extruded from a lamination die at 230° C. to produce a multilayer film with a thickness of 200 μm.
In Table 2, PE2/PE4=70/30 means that PE2 was mixed in a ratio of 70 parts by mass and PE4 parts in a ratio of 30 parts by mass. Others similarly indicate mass proportions.
Moreover, PA/EVOH/PA of the intermediate layer (III) indicates that the intermediate layer (III) is composed of three layers.

〔evaluation〕
The multilayer films of Example 1 and Comparative Example 1 were evaluated for tensile properties, impact resistance, and puncture strength. The results are shown in Table 2 below.

(Tensile properties)
The tensile strength and tensile elongation of the multilayer film were measured in MD (extruder flow direction) using a method according to JIS K7127 (1999) at a tensile speed of 200 mm/min, sample shape: dumbbell, and test atmosphere temperature of 23°C and 5°C. and TD (direction perpendicular to MD) and evaluated based on the following criteria.

[Evaluation criteria for test atmosphere temperature 23°C]
○: MD tensile strength and TD tensile strength are both 80 MPa or more, and MD tensile elongation and TD tensile elongation are both 1000% or more △: Both MD tensile strength and TD tensile strength are 80 MPa or more, and, Either MD tensile elongation or TD tensile elongation is 1000% or more ×: Either MD tensile strength or TD tensile strength is less than 80 MPa, or either MD tensile elongation or TD tensile elongation is 1000% less than

[Evaluation criteria at test atmosphere temperature of 5°C]
○: MD tensile strength and TD tensile strength are both 60 MPa or more, and MD tensile elongation and TD tensile elongation are both 530% or more △: Both MD tensile strength and TD tensile strength are 60 MPa or more, and Either MD tensile elongation or TD tensile elongation is 500% or more and less than 530% ×: Either MD tensile strength or TD tensile strength is less than 60 MPa, or either MD tensile elongation or TD tensile elongation is less than 500%

(Impact resistance)
Puncture energy and puncture displacement of the multilayer film were measured in accordance with JIS K7124-2 (1999) at a speed of 3 m/sec, height of 200 mm, striker diameter of 12.7 mm, and test atmosphere temperatures of 23°C and 5°C. It was measured and evaluated based on the following criteria.

[Evaluation criteria for test atmosphere temperature 23°C]
○: Puncture energy is 2.50 J or more and puncture displacement is 15 mm or more △: Puncture energy is 2.00 J or more and less than 2.50 J and puncture displacement is 15 mm or more ×: Puncture energy is less than 2.00J or puncture displacement is less than 15mm

[Evaluation criteria at test atmosphere temperature of 5°C]
○: Puncture energy is 1.80 J or more and puncture displacement is 11 mm or more △: Puncture energy is 1.50 J or more and less than 1.80 J and puncture displacement is 10 mm or more and less than 11 mm ×: Puncture energy is less than 1.50J or puncture displacement is less than 10mm

(Piercing strength)
The puncture strength of the multilayer film was measured in accordance with JIS Z1707 (2019) at a speed of 200 m/sec, a needle diameter of 1.0 mm, and a test atmosphere temperature of 23° C. and 5° C., and evaluated according to the following criteria.

[Evaluation criteria for test atmosphere temperature 23°C]
○: Piercing strength is 24.0N or more △: Piercing strength is 20.0N or more and less than 24.0N ×: Piercing strength is less than 20.0N

[Evaluation criteria at test atmosphere temperature of 5°C]
○: Piercing strength is 31.5N or more △: Piercing strength is 30.0N or more and less than 31.5N ×: Piercing strength is less than 30.0N

It was found that the multilayer film of Example 1 had better tensile properties, impact resistance, and puncture strength than the multilayer film of Comparative Example 1, and could be suitably used for deep drawing.

From the above examples and the test results conducted by the present inventors, it was found that the polyester resin layer (I) was formed using a polyester resin (Y) with limited physical properties as the main component resin, and the sealing layer (II) etc. It has been found that by laminating and producing a multilayer film, it can be suitably used for deep drawing.

According to the multilayer film of the present invention, the multilayer film has excellent deep drawability while maintaining excellent impact resistance, pinhole resistance, and tensile properties, and can be heat-sealed at low temperatures; A deep-drawn product formed by forming a film can be provided.

Claims (11)

A multilayer film having at least two layers: a polyester resin layer (I) containing a polyester resin (Y) and a sealing layer (II), which satisfies the following conditions a) to c).
a) The content of cobalt element as determined by ICP emission analysis of the polyester resin (Y) is 5 ppm or more.
b) The content of elemental phosphorus as determined by ICP emission analysis of the polyester resin (Y) is 30 ppm or more.
c) The content of antimony element as determined by ICP emission analysis of the polyester resin (Y) is 220 ppm or less. The multilayer film according to claim 1, wherein the polyester resin (Y) is a chemically recycled polyester resin. The polyester resin (Y) is obtained by depolymerizing a polyester resin composition (X) containing as a main resin a polyester condensation polymer containing terephthalic acid as a dicarboxylic acid component and ethylene glycol as a glycol component. The multilayer film according to claim 1 or 2, which is a polyester resin that is decomposed into a glycol component and a glycol component, and polycondensed again. The multilayer film according to claim 3, wherein the polyester resin composition (X) is a packaging material. The multilayer film according to any one of claims 1 to 4, wherein the sealing layer (II) contains a polyolefin resin as a main component resin. The multilayer film according to any one of claims 1 to 5, comprising an intermediate layer (III) as a barrier layer between the polyester resin layer (I) and the sealing layer (II). The multilayer film according to claim 6, wherein the intermediate layer (III) contains a polyamide resin and/or a polyvinyl alcohol resin as a main resin. The multilayer film according to any one of claims 1 to 7, having a thickness of 100 to 500 μm. The multilayer film according to any one of claims 1 to 8, wherein the layer thickness of the polyester resin layer (I) accounts for 50% or more of the total thickness of the multilayer film. A multilayer film for deep drawing, comprising the multilayer film according to any one of claims 1 to 9. A deep-drawn product using the multilayer film for deep-drawing according to claim 10.