JP3068708B2 - Heat shrinkable multilayer film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in heat stretchability, in particular, can be stretched without any pinholes, cracks, local thickness deviations, etc. during the heat stretching operation, and has heat shrinkage and gas barrier properties. The present invention relates to a heat-shrinkable multilayer film using an ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) composition having excellent heat resistance.

[0002]

2. Description of the Related Art Many fatty foods such as raw meat and processed meat have irregular shapes and irregular sizes. As the packaging method of foods having various forms as described above, shrink packaging using a heat-shrinkable film, and skin-pack packaging in which stretching, shrinking and heat sealing are simultaneously performed using a skin-pack packaging machine are industrially used. Has been adopted.

[0003] In shrink packaging, the contents are put into a bag-shaped stretched film, the air in the bag is removed under reduced pressure, the opening of the bag is sealed, and the film is heat-shrinked by heat treatment. Generally, an operation procedure of bringing the contents into close contact with the contents is adopted, and a clean package can be obtained by this procedure. In this operation procedure, the heat treatment may be performed also as sterilization of the contents, usually,
A temperature of 70-120 ° C is employed.

[0004] In the case of skin pack packaging, an unstretched film is passed through a skin pack packaging machine, the film is heated and stretched at a temperature of 60 to 200 ° C in a heated portion, and in some cases, is thermoformed in a mold and then immediately subjected to vacuum. Operation procedure to cover the contents (raw meat, processed meat, etc.) on the base film, sheet, tray, seal the surroundings, return to atmospheric pressure, shrink, and adhere the contents to the surrounding film Is generally adopted, and a clean package can be obtained by this operation procedure.

[0005] Films used in such packaging have excellent gas barrier properties and adhesion, and have a
It is necessary to be able to be easily stretched at 0 ° C. and to have a property of being sufficiently thermally shrunk by heating.

In order to provide these packaging films with high gas barrier properties, it is conceivable to use EVOH having high gas barrier properties. However, EVOH resin films having excellent gas barrier properties require uniform heat shrinkage. It has the disadvantage of being inferior.

Various methods have been proposed to solve this drawback. For example, an EVOH resin film and a polyamide resin (hereinafter, referred to as a PA resin) film are laminated and adhered and stretched and then stretched to form a composite film (JP-A-52-115880).
A laminated film composed of a polyolefin layer, a PA resin layer and an EVOH resin layer (JP-A-56-136365) has been proposed.

[0008]

However, the above E
A film obtained by laminating a VOH resin alone is not always satisfactory in stretchability, and it cannot be said that a film having uniform heat shrinkability can be obtained. Therefore, it is desired to provide a film having a high gas barrier property and exhibiting more excellent stretchability, heat shrinkage, and dimensional stability.

An object of the present invention is to provide a multilayer film having uniform heat shrinkage while maintaining high gas barrier properties of an EVOH resin.

[0010]

The above object is achieved by the following constitution. (1) Compound (B) which satisfies the conditions represented by the following formulas (1) to (3) with respect to 100 parts by weight of EVOH (A) having an ethylene content of at least 20 to 60 mol% and a saponification degree of 90% or more. 0.
A composition layer (C) containing 1 to 30 parts by weight, and at least one resin layer (D) directly in contact with the composition layer (C)
And a heat shrinkable multilayer film having an area shrinkage of 10% or more when immersed in hot water at 90 ° C. for one minute.

5.5 ≧ 19−CH (A) × 0.1−SP (B) ≧ 1.5 (1) 2.5 ≧ SP (B) −SP (D) ≧ −1 (2) BP (B) -MP (A) ≧ −20 (° C.) (3) [In the above formulas (1) to (3), CH (A) is EVO
The ethylene content (mol%) of H (A), the solubility parameter (Fedors equation) of compound (B)
SP (D) indicates the solubility parameter (Fedors equation) of the resin (D) constituting the resin layer (D), BP (B) indicates the boiling point (° C.) of the compound (B), and MP (A) indicates EVOH The melting point (C) of (A) is shown. (2) The heat-shrinkable multilayer film according to the above (1), wherein at least one layer is crosslinked by radiation, electron beam or a chemical method.

In the present invention, EVOH (A) is a saponified ethylene-vinyl ester copolymer having an ethylene content of 20 to 60 mol%, preferably 25 to 58 mol%, and a saponification degree of 90% or more. It is. If the ethylene content is less than 20 mol%, the melt moldability is poor, while if it is 60 mol% or more, the gas barrier properties are insufficient. If the saponification degree is less than 90%,
Gas barrier properties and thermal stability deteriorate.

When the compound (B) satisfies the conditions represented by the formulas (1) to (3), the stretchability of the raw multilayer film before stretching is improved, and the composition after stretching is further improved. When the compound (B) in the layer (C) migrates into the resin layer (D), a gas barrier property is recovered and a multilayer film excellent in heat shrinkage is obtained. It is preferable that the compound satisfies the conditions represented by the following formulas (1) ′ to (3) ′.

5.2 ≧ 19−CH (A) × 0.1−SP (B) ≧ 2 (1) ′ 2.3 ≦ SP (B) −SP (D) ≧ −1 (2) ′ BP (B) -MP (A) ≧ −10 (° C.) (3) ′ When EVOH (A) contains 0.0002 to 0.2 mol% of a vinylsilane compound as a copolymer, EVOH
The melt viscosity of (A) is improved, and not only is it possible to produce a homogeneous coextruded multilayer film, but also the stretchability is improved,
Also, shrinkage is improved.

As the above-mentioned vinylsilane-based compound, compounds represented by the following (I), (II) and (III) are preferable.

[0016]

Embedded image [Where n is 0 to 1, m is 0 to 2, R ¹ is a lower alkyl group, an aryl group, or a lower alkyl group having an aryl group, R ² is an alkoxyl group having 1 to 40 carbon atoms, The alkoxyl group may have a substituent containing oxygen. R ³ is hydrogen or a methyl group, R ⁴ is a hydrogen atom or a lower alkyl group, R ⁵ is a divalent organic residue in which an alkyl group or a chain carbon atom is mutually bonded by oxygen or nitrogen, R ⁶ is hydrogen, halogen , A lower alkyl group, an aryl group, or a lower alkyl group having an aryl group, R ⁷ is an alkoxyl group or an acyloxyl group (where the alkoxyl group or the acyloxyl group may have a substituent containing oxygen or nitrogen. ),
R ⁸ is hydrogen, halogen, a lower alkyl group, an aryl group,
Or, a lower alkyl group having an aryl group, R ⁹ is a lower alkyl group. The lower alkyl group represented by R ¹ is a lower alkyl group having 1 to 5 carbon atoms, the aryl group is an aryl group having 6 to 18 carbon atoms, and the lower alkyl group having an aryl group is 6 to 5 carbon atoms. A lower alkyl group having 1 to 5 carbon atoms having an aryl group of 18; a lower alkyl group represented by R ^{4 includes} a lower alkyl group having 1 to 5 carbon atoms;
The alkyl group represented by ⁵ alkyl groups having 1 to 5 carbon atoms, the lower alkyl group represented by R ⁶ C1-5
The lower alkyl group and the aryl group have 6 to 18 carbon atoms as an aryl group, and the lower alkyl group having an aryl group has 1 to 5 carbon atoms having an aryl group having 6 to 18 carbon atoms.
As a lower alkyl group represented by R ⁸ , a lower alkyl group represented by R ⁸ is a lower alkyl group having 1 to 5 carbon atoms, an aryl group is an aryl group having 6 to 18 carbon atoms, and a lower alkyl group having an aryl group is Examples of the lower alkyl group having 1 to 5 carbon atoms having an aryl group having 6 to 18 carbon atoms and the lower alkyl group represented by R ⁹ include lower alkyl groups having 1 to 5 carbon atoms.

The above vinylsilane compounds (I), (II),
Specific compound names of (III) include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltri (β-methoxy-ethoxy) silane. Among them, vinyltrimethoxysilane and vinyltriethoxysilane are preferably used.

EVOH (A) may be used in the form of other comonomer such as propylene, butylene, unsaturated carboxylic acid or its ester (meth) acrylic acid, (meth) as long as the object of the present invention is not hindered. Acrylic acid esters (methyl, ethyl), etc., vinylpyrrolidone (N-bi
Nylpyrrolidone).
Ku, further, the composition layer (C), plasticizers, heat stabilizers, ultraviolet absorbers, antioxidants, colorants, fillers, other resins (polyamides, partially saponified ethylene - vinyl acetate copolymer, etc.) You may blend. In addition, the melt index (MI) (190) of the EVOH (A) used in the present invention.
° C, 2160g load) is 0.1-50g / 10mi
n. Are preferred, and 0.5 to 20 g / 10 mi
n. Are more preferred.

Examples of the compound (B) include aromatic esters, aliphatic esters, phosphate esters, and epoxidized compounds thereof.
As aromatic esters, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, dicyclohexyl phthalate,
Butyl lauryl phthalate, diisooctyl phthalate, butyl coconut alkyl phthalate, ditridecyl phthalate, dilauryl phthalate, diisodecyl phthalate, butyl benzyl phthalate, octyl decanoyl phthalate, dimethyl glycol phthalate, ethyl phthalyl ethylene glycolate, methyl phthalyl ethylene glycol Rate, butyl phthalyl butylene glycolate, dinonyl phthalate, diheptyl phthalate, octyl decyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, dicapryl phthalate, di-
Examples include 3,5,5-trimethylhexyl phthalate, isooctyl isodecyl phthalate, dimethoxyethyl phthalate, dibutoxydiethyl phthalate, and bis (diethylene glycol monomethyl ether) phthalate. Examples of the aliphatic ester include polypropylene adipate, diisodecyl adipate, di-2-methylhexyl adipate, dicapryl adipate, diisooctyl adipate, octyl decyl adipate, isooctyl isodecyl adipate, dibutyl fumarate, dioctyl fumarate, triethyl citrate, Acetyl triethyl citrate, tributyl citrate, acetyl tributyl citrate, acetyl tri-2-ethylhexyl citrate, etc.
Tricresyl phosphate, phenyl dicresyl phosphate, xylenyl cresyl phosphate, cresyl dixylenyl phosphate, triphenyl phosphate, tributyl phosphate, trichloroethyl phosphate, trioctyl phosphate, triethyl phosphate , Arylalkyl phosphates, diphenyl monoorthoxenyl phosphates and the like, and epoxidized compounds include epoxy monoesters, butyl epoxy stearate, octyl epoxystearate, epoxy butyl oleate, epoxy butyl oleate, epoxidized soybean Oil, epoxidized linseed oil, epoxidized alkyl oil, epoxidized alkyl oil alcohol ester and the like. Among them, epoxidized soybean oil, epoxidized linseed oil, dimethylhexyl adipate, diisooctyl adipate, dibutyl phthalate, diethyl phthalate, di-2-ethylhexyl phthalate, methyl phthalyl ethylene glycolate and the like are preferably used. The compounding amount of the compound (B) is 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight, based on 100 parts by weight of the EVOH (A).

On the other hand, in order to improve the compatibility and thermal stability between the compound (B) and the EVOH (A) separately from the compound (B), for example, it is described in JP-A-60-199040. Such compatibility and thermal stability improvers can be added and used together. Additives used in combination with these compounds (B) include aromatic carboxylic acids, aliphatic carboxylic acids,
Phosphoric acid, a metal salt thereof, a metal complex, a metal oxide, and the like can be given. At least one of these compounds is used. The additive is preferably used in an amount of 0.001 to 1 part by weight, more preferably 0.01 to 1 part by weight, based on 100 parts by weight of the EVOH (A). As the metal to be used, alkali metal, alkaline earth metal, and amphoteric metal are preferable. Examples of these additives include calcium acetate, sodium acetate, magnesium acetate, potassium acetate, zinc acetate, lithium acetate, calcium phosphate, potassium phosphate, magnesium phosphate, lithium phosphate, sodium phosphate, sodium stearate, calcium stearate, Examples include potassium stearate, magnesium stearate, zinc stearate, lithium stearate, sodium salt of ethylenediaminetetraacetic acid, calcium oxide, magnesium oxide, and hydrotalcite-based compounds. Among them, sodium stearate, calcium stearate, potassium stearate, magnesium stearate, calcium acetate, sodium acetate, magnesium acetate, hydrotalcite compound _{{Example: Mg 6 Al 2 (OH)} 16 CO 3 · 4H 2 O}
And the like are preferred.

The multilayer film of the present invention comprises at least the composition layer (C) and the resin layer (D).
The resin layer (D) may have two or more layers. When each of the composition layer (C) and the resin layer (D) has two or more layers, the resin composition constituting each layer may be the same or different. However, at least one resin layer (D) needs to be in direct contact with the composition layer (C).

The multilayer film of the present invention requires at least two layers of the composition layer (C) and the resin layer (D), and further laminates another thermoplastic resin layer to add various functions. be able to.

It is important that the resin layer (D) satisfies the formula (2). By using the resin layer (D) that satisfies the formula (2), the compound in the composition layer (C) in contact with the resin layer (D) is used. (B) moves to the resin layer (D) after stretching, and the gas barrier property is restored.

The resin of the resin layer (D) is preferably an olefin resin. As the olefin resin, a copolymer of ethylene and a vinyl ester monomer, for example, an ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) ), A copolymer of ethylene and a monomer selected from aliphatic unsaturated carboxylic acids and aliphatic unsaturated carboxylic acid esters (for example, selected from acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester and the like). Copolymer of the obtained monomer and ethylene), an ionomer resin, a linear low-density polyethylene (hereinafter referred to as LLDPE), and LLDPE and EVA.
Resin mixed with Vicat softening point (AST
Ultra low density polyethylene (hereinafter abbreviated as VLDPE) of 95 ° C or less, preferably 85 ° C or less, a mixed resin of VLDPE and a small amount of LLDPE, crystalline propylene-ethylene copolymer and polypropylene A mixed resin of an elastomer is preferable.

EVA having a vinyl acetate content of 3 to 19% by weight is preferred. It is preferable from the viewpoint of stretchability that the ratio of EVA in the mixed resin of LLDPE and EVA contains at least 55% by weight. As LLDPE, ethylene and a small amount of butene-1, pentene-1,4-
Copolymers with α-olefins having 4 to 18 carbon atoms, such as methyl-pentene-1, hexene-1, and octene-1, having a crystal melting point of 118 to 125 ° C. are preferred. Examples of the ionomer resin include copolymers of α-olefins such as ethylene and propylene and unsaturated carboxylic acids such as acrylic acid, methacrylic acid and maleic acid, and copolymers of these α-olefins and unsaturated carboxylic acid esters. A partially saponified copolymer in which an anion portion is partially neutralized with a metal ion such as Na, K, Mg, Ca, or Zn is used. Usually, Na and Zn are used. An ionomer resin partially neutralized with a divalent metal ion may contain a polyamide oligomer.

As the resin layer (D), for example, an unsaturated carboxylic acid or its anhydride (such as maleic anhydride), which is used as an adhesive resin layer, is an olefin polymer or copolymer [polyethylene @ low density Polyethylene (LDPE), linear low density polyethylene (LLDP)
E), ultra-low density polyethylene (SLDPE)}, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate (methyl ester or ethyl ester) copolymer] are also preferably used.

The resin layer (D) is laminated on one side or both sides of the composition layer (C).

Further, in the present invention, other constituent layers can be appropriately provided. Here, as another constituent layer, for example, polyamide resin (PA), specifically, nylon 6,
Nylon 9, Nylon 11, Nylon 12, Nylon 6
6, a copolymer of two or more monomers of nylon 69, nylon 611, and nylon 612; and nylon 6, nylon 9, nylon 11, nylon 12, nylon 66,
Nylon 69, nylon 611, and nylon 612 can be used. Also, aromatic nylons having better gas barrier properties than the above nylons, for example, a polymer of adipic acid and meta-xylylenediamine, a polymer of hexamethylene diamine and m, p-phthalic acid, or a polymer thereof Also preferred are those comprising a copolymer of the above and the PA resin, or a melt blend.

The above-mentioned olefin-based resin layer may be provided as these other constituent layers at positions not directly in contact with the composition layer (C). One or more layers may be provided.

The composition layer (C), the resin layer (D), and other constituent layers may contain inorganic additives such as inorganic fillers and pigments and / or organic additives as long as they do not impair stretchability and gas barrier properties. Additives and recovered and reused products such as trim and debris generated during film production can be added.

The thickness of the resin layer (D) in the multilayer film of the present invention is preferably 3 μm or more from the viewpoint of heat resistance and 1000 μm or less from the viewpoint of stretchability and dimensional stability. Further, the thickness of the composition layer (C) is determined from the balance between gas barrier properties and stretchability.
It is preferably from 3 to 20 μm, more preferably from 3 to 15 μm. The thickness of the resin layer (D) is preferably larger than the thickness of the composition layer (C). When the composition layer (C) and the resin layer (D) each have two or more layers, the resin layer (D) )
Is preferably larger than the total thickness of the composition layer (C).

The composition of the multilayer film is as follows: (1) composition layer (C) / resin layer (D) / polyolefin resin layer;
Polyolefin resin layer / resin layer (D) / composition layer (C)
/ Resin layer (D) / polyolefin resin layer, (3) polyolefin resin layer / resin layer (D) / composition layer (C) / PA resin layer / adhesive resin layer / polyolefin resin layer, (4) PA
Resin layer / composition layer (C) / resin layer (D) / polyolefin resin layer, (5) polyolefin resin layer / resin layer (D) /
A typical example is a composition layer (C) / resin layer (D) / PA resin layer / adhesive resin layer / polyolefin resin layer. When a polyolefin resin layer is provided as another constituent layer on both outer layers, the resins may be different or may be the same.

The method for producing the heat-shrinkable multilayer film of the present invention will be described below.

The composition layer (C), the resin layer (D) and other necessary constituent layers are formed by extrusion lamination, dry lamination,
A laminate is obtained by laminating by a coextrusion laminating method, a coextrusion sheet molding method, a coextrusion inflation molding method, a solution coating method, or the like. At this time, it is preferable that the extruded laminate is immediately quenched and made substantially amorphous as much as possible. Then
The laminate is reheated within the range of the melting point of EVOH (A) or less, and is uniaxially or biaxially stretched by a roll stretching method, a pantograph stretching method, an inflation stretching method, or the like. Prior to stretching, the laminate is irradiated with radiation, electron beam, ultraviolet ray, or the like to crosslink the composition layer (C), the resin layer (D), the multilayer film constituent layer, especially the polyolefin resin layer, or at the time of extrusion molding. The addition of a chemical cross-linking agent for chemical cross-linking, or the use of a multilayer structure in which a composition layer (C) and a resin layer (D) are laminated on a cross-linked polyolefin resin layer is more advantageous because stretch moldability is further improved. It is suitable.
The stretching ratio is 1.3-9 for each of vertical and / or horizontal
Times, preferably 1.5 to 4 times, and as the heating temperature,
The temperature is 50 to 140 ° C, preferably 60 to 100 ° C. Heating temperature is 50
If the temperature is lower than ℃, the stretchability is deteriorated and the dimensional change is increased.
If the heating temperature exceeds 140 ° C., a desired heat shrinkage cannot be obtained. The area shrinkage when the heat shrinkable multilayer film of the present invention is immersed in hot water at 90 ° C. for 1 minute is 10% or more,
It is more preferably at least 15%. If the area shrinkage rate is less than 10%, the surface of the packaged product may be wrinkled,
The adhesion between the contents and the packaging film is impaired, resulting in a poor appearance of the product.

In the present invention, the water content of the composition layer (C) is not particularly limited, but may be 0.001.
It is preferred that it is within 10% by weight.

[0036]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto. Example 1 Ethylene content: 44 mol%, degree of saponification: 99.6%, melt index (MI) (190 ° C., load of 2160 g) 5.5 g / 10 min.
100 parts by weight of EVOH (A), 8 parts by weight of diethyl phthalate (B) and 0.1 part by weight of sodium stearate are dry blended, and a 30 mmφ twin screw extruder is used at 220 ° C.
And pelletized.

The above pellets were mixed with the EVOH of the composition layer (C).
It is used as a resin composition, and is applied to a co-extrusion device of four types and five layers,
The outermost layers are EVA resin (Mitsui DuPont Chemical: Evaflex EV-340) layers each having a thickness of 300 μm, the center of the innermost layer is the above EVOH composition layer having a thickness of 50 μm, and 50 μm between the EVA resin layer and the EVOH composition layer. (Mitsui Petrochemical Admer VF-600, maleic anhydride modified product of EVA resin) layer (D). The obtained sheet was applied to a pantograph-type biaxial stretching machine and simultaneously biaxially stretched at 70 ° C. at a stretching ratio of 3 × 3 to obtain a multilayer heat-shrinkable film. The sheet showed good stretchability.

The obtained multilayer heat shrinkable film has cracks,
There was little unevenness and uneven wall thickness, and the appearance (transparency, gel spots) was relatively good. This film was conditioned at 20 ° C.-100% RH, and the gas barrier property was measured (10/100 by Mocon).
50 type), 30cc. 20 μm / m ² . 24 hr. Atm and good gas barrier properties were shown. Also, the heat shrinkage at 90 ° C was measured.
It showed an area shrinkage of 50%. Furthermore, after leaving the stretched film for one month (dry state), the gas barrier property (20 ° C
-100% RH), and heat shrinkage was measured. Two
0 μm / m ² . 24 hr. atm and better gas barrier properties,
A good area shrinkage (54%) was shown.

The thickness of the above-mentioned five-layer sheet is set to 30 μm for each of the outermost EVA resin layers and to 30 μm for the adhesive resin layer.
A multilayer heat-shrinkable film was produced in the same manner except that the thickness of the EVOH resin composition layer at the center of the innermost layer was changed to 10 μm. The obtained sheet was applied to a skin-pack wrapping machine (manufactured by Mulchback) to perform skin-pack wrapping. As a result, the appearance of the packaging film was relatively good, with few wrinkles and crushing of the contents. Example 2-6, Comparative Example 1-4 As shown in Table 1 and Table 2, except that the composition layer (C) and the resin layer (D) were changed, the multilayer heat treatment was carried out under the same conditions as those described in the preceding paragraph of Example 1. A shrinkable film was obtained. However, in Comparative Example 3, the layer configuration was a two-layered three-layer configuration of resin layer (D) / composition layer (C) / resin layer (D). The stretchability of each film was examined, and gas barrier properties, heat shrinkage properties, and skin pack properties were determined in the same manner as in Example 1. Example 7 A multilayer heat-shrinkable film was prepared in the same manner as described in the preceding paragraph of Example 1, except that the raw multilayer film before stretching was irradiated with 5 Mrad of electron beam. The stretchability of each film was examined.

The results of Examples 1 to 7 and Comparative Examples 1 to 4 are summarized in Tables 2 and 3.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3] In Tables 1 to 3, the values are shown in parts by weight per 100 parts by weight of * EVOH (A).

Compound (B) a: DEP = diethyl phthalate b: DOA = dioctyl adipate c: Gly = glycerin d: TPP = triphenyl phosphate additive i: sodium stearate ii: zinc stearate resin PA: 6 .66 nylon

[0045]

The original multilayer film before stretching used in the present invention has excellent stretchability, and the heat-shrinkable multilayer film obtained by stretching this film has high gas barrier properties and excellent uniformity. It has heat shrinkability, and also has excellent adhesion to the contents during the heat shrink operation.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI B29L 7:00 9:00 (58) Field surveyed (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 B29C 61/00-61/10

Claims (2)

(57) [Claims] 1. An ethylene-vinyl alcohol copolymer (A) having an ethylene content of at least 20 to 60 mol% and a degree of saponification of 90% or more (hereinafter referred to as EVOH (A)) per 100 parts by weight of the following formula: A composition layer (C) containing 0.1 to 30 parts by weight of the compound (B) satisfying the conditions represented by (1) to (3), and at least one layer in direct contact with the composition layer (C)
A heat-shrinkable multilayer film having a resin layer (D), and having an area shrinkage of 10% or more when immersed in hot water at 90 ° C. for 1 minute. 5.5 ≧ 19−CH (A) × 0.1−SP (B) ≧ 1.5 (1) 2.5 ≧ SP (B) −SP (D) ≧ −1 (2) BP (B) -MP (A) ≧ −20 (° C.) (3) [In the above formulas (1) to (3), CH (A) is EVO
The ethylene content (mol%) of H (A), the solubility parameter (Fedors equation) of compound (B)
SP (D) indicates the solubility parameter (Fedors equation) of the resin (D) constituting the resin layer (D), BP (B) indicates the boiling point (° C.) of the compound (B), and MP (A) indicates EVOH The melting point (C) of (A) is shown. ] 2. The heat-shrinkable multilayer film according to claim 1, wherein at least one layer is crosslinked by radiation, electron beam, or a chemical method.