JP5837438B2 - Multilayer film - Google Patents

Description

  The present invention relates to a multilayer film excellent in moisture resistance, transparency, and heat sealability.

  As a food packaging film or a pharmaceutical packaging film, a film made of a polyolefin resin or a polyamide resin is widely used as a single film or as a laminated film with another film. In particular, in applications such as liquid-filled packaging, polyamide resin films are widely used because of their excellent oxygen gas barrier properties, flex resistance, transparency, heat resistance, toughness, and the like.

  When such a polyamide-based resin film is used for seasonings such as miso and soy sauce, water-containing foods such as soups and retort foods, or medicine packaging bags, a polyamide-based film laminate provided with a sealant layer In general, a bag was produced from this laminate, and the contents were filled through the opening of the bag, and then the opening was heat-sealed and packaged. At this time, as the sealant layer having heat sealability, linear low-density polyethylene (hereinafter abbreviated as “LLDPE”), polypropylene, or the like is generally used.

Among them, from the viewpoint of transparency and heat sealability, a sealant layer mainly composed of an ethylene-based resin such as LLDPE is widely used. Particularly, those obtained by inflation molding are generally used from the viewpoint of productivity and cost. Have been used.
However, the LLDPE sealant layer obtained by inflation molding has been difficult to use for applications requiring high moisture resistance.
Therefore, a technique using a medium-density polyethylene or a high-density polyethylene obtained by inflation molding has been proposed. For example, Patent Document 1 discloses a multilayer film obtained by laminating a polyamide-based resin film using a medium-density polyethylene or high-density polyethylene blow-molded as a sealant layer.

JP 2001-278355 A

  The packaging bag using the laminated film described in Patent Document 1 has a coarse spherulite size due to slow cooling of the film, often impairs transparency and heat sealability, and lacks practicality. Met. Thus, in the prior art, there was no practical multilayer film having a sufficient moisture-proof property, transparency, and heat-sealability, which was a multilayer film of a sealant layer obtained by inflation molding and other layers. .

  Accordingly, an object of the present invention is to provide a new multilayer film having sufficient moisture resistance, transparency, and heat sealability in view of the problems of the prior art.

The present invention is an ethylene polymer (A), a nucleating agent (B), and one or more selected from the group consisting of petroleum resins, terpene resins, coumarone-indene resins, rosin resins, and hydrogenated derivatives thereof. A multilayer film comprising a resin layer (I) containing an olefin-compatible resin (C) composed of two or more combinations, and a layer other than the resin layer (I), wherein the resin layer (I ) Proposes a multilayer film characterized by satisfying the following conditions (i) to (iii).
Condition (i): Density is 0.940 g / cm ^{3 to} 0.960 g / cm ³
Condition (ii): heat of crystal fusion (ΔHm) is 120 J / g to 160 J / g
Condition (iii): Storage shear modulus (G ′) at 200 ° C. is 2,000 Pa to 50,000 Pa

  Since the multilayer film proposed by the present invention has sufficient moisture resistance, transparency, and heat sealability, moisture resistance, transparency, and heat sealability are required, for example, for packaging materials such as foods and pharmaceuticals. It can be suitably used as a packaging material.

  Hereinafter, a multilayer film (referred to as “the present multilayer film”) as an example of an embodiment of the present invention will be described. However, the scope of the present invention is not limited to the embodiments described below.

<Multilayer film>
This multilayer film comprises an ethylene polymer (A), a nucleating agent (B), a resin layer (I) containing an olefin-compatible resin (C), and other layers other than the resin layer (I). Or it is a multilayer film provided with two or more layers.

  In the present multilayer film, the resin layer (I) is preferably used as a sealant layer, that is, it constitutes at least one outermost layer of the multilayer film.

<Resin layer (I)>
The resin layer (I) is a layer containing an ethylene polymer (A), a nucleating agent (B), and an olefin compatible resin (C).
By providing the resin layer (I), not only can it provide heat sealability when used in various packaging materials, it also provides excellent moisture resistance and suppresses deterioration of contents when used as various packaging materials. can do.

(Ethylene polymer (A))
The ethylene polymer (A) used in the multilayer film may be an ethylene homopolymer, or may be a copolymer of ethylene and a monomer component other than ethylene, particularly an α-olefin. Good. A mixture of these can also be used.

Here, examples of the α-olefin copolymerized with ethylene include propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, and 3-methyl. -Butene-1,4-methyl-pentene-1 etc. can be illustrated. Among these, propylene, butene-1, hexene-1, and octene-1 are preferable from the viewpoints of industrial availability, various characteristics, and economical efficiency.
The α-olefin copolymerized with ethylene may be used alone or in combination of two or more.

  Among these, an ethylene homopolymer or a copolymer of ethylene and an α-olefin comprising one or a combination of two or more selected from the group consisting of butene-1, hexene-1 and octene-1 Is preferably used.

  When a copolymer of ethylene and an α-olefin composed of one or a combination of two or more selected from the group consisting of butene-1, hexene-1 and octene-1 is used, it occupies the copolymer The total of the ratios of butene-1, hexene-1 and octene-1 is preferably 0.1 to 10.0% by mass, more preferably 0.3% by mass or more and 5.0% by mass or less. More preferably, it is 5 mass% or more or 3.0 mass% or less. If the proportion of the α-olefin is within such a range, the multilayer film can be further improved in moisture resistance and transparency.

  The molecular weight distribution index (Mw / Mn) of the ethylene polymer (A) is 2.5 to 6 in order to form fine crystals when a nucleating agent is added and to improve transparency and moisture resistance. 0.0, preferably 2.6 or more and 5.5 or less, more preferably 3.0 or more and 5.0 or less.

Further, in order to achieve both transparency and moisture resistance, the density of the ethylene polymer (A) is preferably in the range of 0.936~0.955g / cm ^3, among them 0.938 g / cm ³ or more, or It is more preferably 0.953 g / cm ³ or less, and more preferably 0.940 g / cm ³ or more or 0.951 g / cm ³ or less. If the density of the ethylene polymer (A) is within such a range, the transparency and moisture resistance of the multilayer film can be further enhanced.

The ethylene-based polymer (A) has a crystal melting peak temperature (Tm) measured at a heating rate of 10 ° C./min in differential scanning calorimetry of 100 to 145 ° C. and a crystal melting heat amount (ΔHm) of 120. It is preferable that ˜190 J / g is satisfied. By using the ethylene polymer (A) having a crystal melting peak temperature (Tm) and a crystal melting heat quantity (ΔHm) within such a range, both transparency and moisture resistance can be achieved.
Among them, the crystal melting peak temperature (Tm) is more preferably 115 ° C. or higher or 140 ° C. or lower, and further preferably 130 ° C. or higher.
The crystal melting heat (ΔHm) is more preferably in the range of 135 to 185 J / g, and more preferably 150 J / g or more or 180 J / g or less.
The crystal melting peak temperature (Tm) can be measured at a heating rate of 10 ° C./min according to JIS K7121 using a differential scanning calorimeter, and the crystal melting calorie (ΔHm) is the differential scanning calorific value. Using a meter, it can be measured at a heating rate of 10 ° C./min according to JIS K7122.

(Nuclear agent (B))
The type of the nucleating agent (B) used in the multilayer film is not particularly limited as long as the effect of improving the transparency and moisture resistance of the ethylene polymer (A) is recognized.
Examples of this type of nucleating agent include, for example, aliphatic, alicyclic, and aromatic carboxylic acids, dicarboxylic acids or polybasic polycarboxylic acids, metal salts of organic acids such as the corresponding anhydrides and metal salts, Cyclic bis-phenol phosphates, bicyclic dicarboxylic acids such as disodium bicyclo [2.2.1] heptene dicarboxylic acid, and metal salts thereof, such as bicyclo [2.2.1] heptane-dicarboxylate Bicyclic dicarboxylates and their metal salts, 1,3: 2,4-O-dibenzylidene-D-sorbitol, 1,3: 2,4-bis-O- (m-methylbenzylidene) -D -Sorbitol, 1,3: 2,4-bis-O- (m-ethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (m-isopropylbenzylidene) -D-sol Tol, 1,3: 2,4-bis-O- (mn-propylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (mn-butylbenzylidene) -D- Sorbitol, 1,3: 2,4-bis-O- (p-methylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethylbenzylidene) -D-sorbitol, 1, 3: 2,4-bis-O- (p-isopropylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pn-propylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (pn-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,3-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,4-dimethylben Redene) -D-sorbitol, 1,3: 2,4-bis-O- (2,5-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,4-dimethyl) Benzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,5-dimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,3-diethyl) Benzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,4-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (2,5-diethyl) Benzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,4-diethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,5-diethyl Benzylidene) -D-sorbitol, 1,3: 2,4 -Bis-O- (2,4,5-trimethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,4,5-trimethylbenzylidene) -D-sorbitol, 1,3 : 2,4-bis-O- (2,4,5-triethylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (3,4,5-triethylbenzylidene) -D-sorbitol 1,3: 2,4-bis-O- (p-methyloxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (p-ethyloxycarbonylbenzylidene) -D-sorbitol 1,3: 2,4-bis-O- (p-isopropyloxycarbonylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (on-propyloxycarbonylbenzylidene) D-sorbitol, 1,3: 2,4-bis-O- (on-butylbenzylidene) -D-sorbitol, 1,3: 2,4-bis-O- (o-chlorobenzylidene) -D- Sorbitol, 1,3: 2,4-bis-O- (p-chlorobenzylidene) -D-sorbitol, 1,3: 2,4-bis-O-[(5,6,7,8, -tetrahydro- 1-naphthalene) -1-methylene] -D-sorbitol, 1,3: 2,4-bis-O-[(5,6,7,8, -tetrahydro-2-naphthalene) -1-methylene] -D Sorbitol, 1,3-O-benzylidene-2,4-Op-methylbenzylidene-D-sorbitol, 1,3-Op-methylbenzylidene-2,4-O-benzylidene-D-sorbitol, , 3-O-benzylidene-2,4-Op- Ethylbenzylidene-D-sorbitol, 1,3-Op-ethylbenzylidene-2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-Op-chlorobenzylidene-D -Sorbitol, 1,3-O-p-chlorobenzylidene-2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-O- (2,4-dimethylbenzylidene) -D -Sorbitol, 1,3-O- (2,4-dimethylbenzylidene) -2,4-O-benzylidene-D-sorbitol, 1,3-O-benzylidene-2,4-O- (3,4-dimethyl) Benzylidene) -D-sorbitol, 1,3-O- (3,4-dimethylbenzylidene) -2,4-O-benzylidene-D-sorbitol, 1,3-Op-methyl-ben Riden-2,4-Op-ethylbenzylidenesorbitol, 1,3-p-ethyl-benzylidene-2,4-p-methylbenzylidene-D-sorbitol, 1,3-Op-methyl-benzylidene-2 , 4-Op-chlorobenzylidene-D-sorbitol, diacetal compounds such as 1,3-Op-chloro-benzylidene-2,4-Op-methylbenzylidene-D-sorbitol, sodium 2,2 ′ -Methylene-bis- (4,6-di-tert-butylphenyl) phosphate, aluminum bis [2,2'-methylene-bis- (4-6-di-tert-butylphenyl) phosphate], 2,2- Phosphate ester compounds such as methylene bis (4,6-di-tert-butylphenyl) sodium phosphate, caproic acid, enan Fatty acids such as toic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, montanic acid , Fatty acid amides such as oleic acid amide, erucic acid amide, stearic acid amide, hebenic acid amide, fatty acid metal salts such as magnesium stearate, zinc stearate, calcium stearate, inorganic particles such as silica, talc, kaolin, calcium carbide, And higher fatty acid esters such as glycerol and glycerol monoester.
Among these, fatty acid amides such as oleic acid amide, erucic acid amide, stearic acid amide, and hebeninic acid amide, and fatty acid metal salts such as magnesium stearate, zinc stearate, and calcium stearate are particularly preferable.
One of these crystal nucleating agents can be used alone, or two or more of these can be used in combination.

  Specific examples of the nucleating agent (B) include “Gelall D” series, “Gelall MD” series manufactured by Shin Nippon Rika Co., Ltd., “Adeka Stub” series manufactured by Asahi Denka Kogyo Co., Ltd., “Millad” series manufactured by Milliken Chemical, “Hyperform”. Series, “IRGACLEAR” series manufactured by BASF, and the like, and as a master batch of the crystal nucleating agent, “Rike Master CN” series manufactured by Riken Vitamin Co., “HL3-4” manufactured by Milliken Chemical, etc. Among these, those having a particularly high effect of improving transparency include “HYPERFORM HPN-20E” and “HL3-4” manufactured by Milliken Chemical Co., Ltd., “Rike Master CN-001” and “Rike Master CN-002” manufactured by Riken Vitamin Co., Ltd. Can be mentioned.

(Olefin compatible resin (C))
By adding the olefin compatible resin (C) to the ethylene polymer (A), not only the moisture resistance can be improved, but also excellent heat sealability can be imparted.

  In the present invention, “compatible” or “compatible resin” means a state of good affinity at the molecular level, and the ethylene polymer (A) and the olefin compatible resin (C) are compatible. Then, it means a state in which the glass transition temperature of the mixture of the ethylene polymer (A) and the olefin compatible resin (C) is single.

  The olefin compatible resin (C) is preferably a resin that is compatible with an olefin resin, particularly an ethylene polymer (A), and has a glass transition temperature higher than that of the ethylene polymer (A). Examples of such resins include petroleum resins, terpene resins, coumarone-indene resins, rosin resins, and mixed resins composed of one or more combinations selected from the group consisting of these hydrogenated products. Can be mentioned.

  Examples of the petroleum resin include alicyclic petroleum resin from cyclopentadiene or its dimer, aromatic petroleum resin from C9 component, and the like. Examples of the terpene resin include terpene-phenol resins from β-pinene. Moreover, as a coumarone-indene resin, a coumarone-indene copolymer, a coumarone-indene-styrene copolymer, etc. can be mentioned, for example. Furthermore, examples of the rosin resin include rosin resins such as gum rosin and wood rosin, and esterified rosin resins modified with glycerin, pentaerythritol, and the like.

  The olefin-compatible resin (C) exhibits relatively good compatibility when mixed with the ethylene polymer (A), and from the viewpoint of further improving the color tone, thermal stability, compatibility, moisture permeability resistance, and the like. Hydrogenated product, especially hydrogenation rate (hereinafter referred to as “hydrogenation rate”) is 95% or more, and does not substantially contain polar groups such as hydroxyl groups, carboxyl groups, halogens, or unsaturated bonds such as double bonds. It is preferable to use petroleum resin or terpene resin.

The olefin compatible resin (C) can be obtained in various softening temperatures by changing the molecular weight.
The softening temperature Ts (C) measured based on JIS K2207 of the olefin compatible resin (C) is the crystallization peak temperature measured at a cooling rate of 10 ° C./min in the differential scanning calorimetry of the ethylene polymer (A). Tc (A) + 15 ° C. or lower, that is, it is preferable not to reach a high temperature exceeding the crystallization peak temperature Tc (A) + 15 ° C., more preferably Tc (A) + 10 ° C. or lower, Tc (A) + 5 ° C. or lower More preferably. In addition, it is preferable that the minimum of Ts (C) is 80 degreeC.
When the upper limit of the softening temperature Ts (C) of the olefin compatible resin (C) satisfies the above condition, the degree of freedom of the olefin compatible resin (C) molecule is high in the crystallization process of the ethylene polymer (A). In this state, crystallization of the ethylene polymer (A) is not inhibited, fine crystals are formed, and a polyethylene sheet having excellent transparency can be obtained. In addition, when Ts (C) is 80 ° C. or higher, blocking of pellets during molding and bleeding out to the surface of the molded product during secondary processing, transportation, or use will not occur.

  Specific examples of the olefin compatible resin (C) include, for example, “Highlets” series, “Petrogin” series, “Arcon” series by Arakawa Chemical Industries, “Clearon” series by Yashara Chemical, Idemitsu Petrochemical Co., Ltd. “Imabe” series made by the company, “Escollet” series made by Tonex, etc.

(Content ratio)
In the resin layer (I), the content of the ethylene polymer (A) is preferably 40 to 90% by mass of the entire resin layer (I), and more preferably 45% by mass or more or 85% by mass or less. Of these, more preferably 50% by mass or more or 80% by mass or less. By blending the ethylene polymer (A) within such a range, a multilayer film having excellent heat resistance and impact resistance can be provided.

  The content of the nucleating agent (B) is preferably 0.01 to 3.0% by mass of the entire resin layer (I), and more preferably 0.03% by mass or more or 2.0% by mass or less. More preferably, it is more preferably 0.05% by mass or more or 1.0% by mass or less. By blending the nucleating agent (B) within such a range, the transparency and moisture resistance of the multilayer film can be further improved effectively without causing a decrease in transparency due to excessive addition of the crystal nucleating agent. it can.

  The content of the olefin compatible resin (C) is preferably 5 to 30% by mass of the entire resin layer (I), more preferably 10% by mass or more and 25% by mass or less. In particular, the content is more preferably 15% by mass or more and 20% by mass or less. By blending the olefin-compatible resin (C) within such a range, the olefin-compatible resin does not bleed to the sheet surface, and effectively does not cause molding defects due to a decrease in melt viscosity. The moisture resistance of the multilayer film can be improved.

(Other ingredients)
The resin layer (I) may contain a resin other than the ethylene polymer (A), the nucleating agent (B), and the olefin-compatible resin (C) as long as the effects of the present invention are not impaired. For example, a polyolefin-based resin, a polystyrene-based resin, a polyester-based resin, a polyolefin-based, or a polystyrene-based thermoplastic elastomer can be blended. For example, if a cyclic olefin resin is contained, the transparency can be further improved.
At this time, the content of the cyclic olefin resin is 10 to 50% by mass with respect to the total content of the ethylene polymer (A), the nucleating agent (B) and the olefin compatible resin (C). Among them, 20% by mass or more or 45% by mass or less is preferable, and more preferably 25% by mass or more or 35% by mass or less.

(Physical properties of resin layer (I))
It is important that the resin layer (I) satisfies the following conditions (i) to (iii).
Condition (i): Density is 0.940 g / cm ^{3 to} 0.960 g / cm ³
Condition (ii): heat of crystal fusion (ΔHm) is 120 J / g to 160 J / g
Condition (iii): Storage shear modulus (G ′) at 200 ° C. is 2,000 Pa to 50,000 Pa

A more preferable range of the density in the condition (i) is 0.942 g / cm ³ or more or 0.958 g / cm ³ or less, and a more preferable range is 0.944 g / cm ³ or more or 0.954 g / cm ³ or less. is there.
Further, the lower limit of the more preferable range of the heat of crystal fusion (ΔHm) in the condition (ii) is 125 J / g or more, and the more preferable range is 130 J / g or more. Moreover, it is preferable that an upper limit is 160 J / g or less.
If the density and heat of crystal fusion (ΔHm) of the resin layer (I) are within such ranges, the present multilayer film excellent in all of excellent transparency, moisture resistance and heat sealability can be provided.

Moreover, the more preferable range of the storage shear modulus (G ′) at 200 ° C. in the above condition (iii) is 3,000 Pa or more or 40,000 Pa or less, and the more preferable range is 4,000 Pa or more or 30,000 Pa or less. is there.
If the storage shear modulus (G ′) at 200 ° C. of the resin layer (I) is within such a range, it has excellent moldability (bubble stability) particularly in inflation molding, and has excellent transparency and appearance. A film can be obtained.

  Whether or not the resin layer (I) satisfies the above conditions (i) to (iii) is determined by using the resin composition (X) constituting the resin layer (I) as a sample as in the examples described later. Each value of the conditions (i) to (iii) may be measured, or a part of the resin layer (I) in the multilayer film is collected and used as a sample for the conditions (i) to (iii) ) May be measured.

  In order to obtain a resin composition that satisfies the above conditions (i) to (iii), in addition to blending the nucleating agent (B) and the olefin-compatible resin (C) in the range described above, the ethylene-based resin The melt viscosity of the polymer (A) is preferably in the following range. Specifically, the MFR measured at a temperature of 190 ° C. and a load of 2.16 kg of the ethylene polymer (A) is preferably from 0.1 g / 10 min to 5.0 g / 10 min, and 0.2 g / It is more preferably 10 minutes to 2.0 g / 10 minutes, and still more preferably 0.3 g / 10 minutes to 1.0 g / 10 minutes. By using the ethylene polymer (A) within such a range, a film having excellent bubble stability in inflation molding and a good appearance can be obtained.

Therefore, it is preferable that the resin layer (I) further satisfies the following condition (iv).
Condition (iv): MFR measured at a temperature of 190 ° C. and a load of 2.16 kg is 0.1 g / 10 min to 5.0 g / 10 min. A more preferable range of MFR in the above condition (iv) is 0.2 g / 10 min to It is 4.0 g / 10 minutes, and a more preferable range is 0.5 g to 3.0 g / 10 minutes. When the MFR of the resin layer (I) is within such a range, a film having excellent bubble stability and good appearance can be collected in inflation molding.

<Laminated structure>
Examples of the layers other than the resin layer (I) included in the multilayer film include polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyamide resins, polystyrene resins, polyethylene, polypropylene, and ethylene- A layer containing a polyolefin resin such as a saponified vinyl acetate copolymer can be exemplified.
Among these, from the viewpoints of oxygen gas barrier properties, flex resistance, toughness, etc., among polyamide resins described later, a layer containing polyamide MXD6 (polymetaxylene adipamide), or a higher oxygen gas barrier property. In view of the above, it is preferable to contain a saponified ethylene-vinyl acetate copolymer described later.

  In the present multilayer film, the resin layer (I) is preferably used as a sealant layer, that is, it constitutes at least one outermost layer of the multilayer film.

In addition, the thickness ratio of the resin layer (I) in the multilayer film is preferably 50 to 90%, more preferably 55% or more and 85% or less, and more preferably 60% or more or 80. More preferably, it is% or less.
If the thickness ratio of the resin layer (I) in the multilayer film is within such a range, the multilayer film can be provided with excellent moisture resistance and heat sealability.

(Polyamide resin)
Although it does not specifically limit as said polyamide-type resin, It is preferable to use what has a 3-membered or more lactam, the polymerizable omega-amino acid, diamine, and dicarboxylic acid as a main component.

When the polyamide resin is a copolymer, the polyamide component is preferably contained in an amount of 80 mol% or more, more preferably 85 mol% or more, and still more preferably 90 mol% or more.
When the polyamide-based resin is a composition containing other resins, additives, etc., the proportion of the polyamide component in the composition part is preferably 70% by mass or more, and 75% by mass or more. Is more preferable, and it is further more preferable that it is 80 mass% or more.

As said 3 or more membered lactam, (epsilon) -caprolactam, (gamma) -undecane lactam, (omega) -lauryl lactam etc. can be mentioned, for example.
Examples of the polymerizable ω-amino acid include ω-aminocaproic acid, ω-aminoheptanoic acid, ω-aminononanoic acid, ω-aminoundecanoic acid, and ω-aminododecanoic acid.

Examples of the diamine include tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and 2,2,4-tomethyl. Aliphatic amines such as hexamethylene diamine and 2,4,4-tochimethyl hexamethylene diamine, 1,3 / 1,4-bis (aminomethyl) cyclohexane, isophorone diamine, piperazine, bis (4-aminocyclohexyl) methane, Mention may be made of alicyclic diamines such as 2,2-bis- (4′-aminocyclohexyl) propane, and aromatic diamines such as metaxylylenediamine and paraxylylenediamine.
Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedioic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, and hexahydroterephthalic acid. , Alicyclic carboxylic acids such as hexahydroisophthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid (1,2-isomer, 1,3-isomer, 1,4-isomer, 1,5-isomer, 1,6 -Aromatic 1, carboxylic acid such as 1,7-isomer, 1,8-isomer, 2,3-isomer, 2,6-isomer, 2,7-isomer), and metal salts of sulfoisophthalic acid. .

  Specific examples of the polyamide-based resin derived from a lactam having three or more members as described above, a polymerizable ω-amino acid, a diamine and a dicarboxylic acid include, for example, polyamide 4, polyamide 6, polyamide 7, polyamide 11, Polyamide 12, Polyamide 4,6, Polyamide 6,6, Polyamide 6,9, Polyamide 6,10, Polyamide 6,11, Polyamide 6T, Polyamide 6I, Polyamide MXD6 (Polymetaxylylene adipamide), Polyamide 6-6 6, polyamide 6-6,10, polyamide 6-6,11, polyamide 6,12, polyamide 6-6,12, polyamide 6-6T, polyamide 6-6I, polyamide 6-6,6-6,10, polyamide 6-6, 6-12, polyamide 6-6, 6-6, 12, polyamide 6,6-6T, poly Bromide 6,6-6I, polyamide 6T-6I, polyamide 6,6-6T-6I and the like. These polyamide resins may be homopolymers, copolymers or mixtures thereof.

(EVOH)
As described above, for example, for the purpose of improving moisture resistance, a layer containing a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as “EVOH”) can be provided.

  At this time, the EVOH is not particularly limited. EVOH produced by a known method can be used. Among them, in particular, the lower limit of the ethylene content is 25 mol% or more, more preferably 29 mol% or more, the upper limit is 38 mol% or less, more preferably 35 mol% or less, and the lower limit of the saponification degree is 95 mol%. As described above, EVOH having 98 mol% or more and an upper limit of 100 mol% or less is particularly suitable as the EVOH used for the multilayer film. When the ethylene content is in the range of 25 mol% or more and 38 mol% or less, the melt extrudability at the time of melt extrusion becomes good, and the molded product appearance, mechanical strength, and oxygen gas barrier properties become good. Moreover, if the saponification degree of EVOH is in the range of 95 mol% or more and 100 mol% or less, the oxygen gas barrier property and moisture resistance are good.

  In addition to the saponified product of ethylene and vinyl acetate binary copolymer, the EVOH includes a small amount of α-olefin such as propylene, butene-1, hexene-1, octene-1, etc. It may contain carboxylic acid or a salt thereof.

  In addition, resins such as polyolefins, polyamide elastomers, and polyester elastomers can be added for the purpose of imparting flexibility, impact resistance and the like to the polyamide resin or EVOH.

  The above polyolefins are mainly composed of polyethylene units and polypropylene units in the main chain, and may be graft-modified with maleic anhydride or the like. As structural units other than the polyethylene unit and the polypropylene unit, vinyl acetate or a partially saponified product thereof, (meth) acrylic acid, or a partial metal ion neutralized product thereof, (meth) acrylic acid esters, butene, etc. -Alkenes, alkadienes, styrenes and the like can be mentioned. A plurality of these structural units may be included.

  The above polyamide elastomers belong to polyamide block copolymers such as polyether amide and polyether ester amide, and examples of amide components include polyamide 6, polyamide 6, 6, polyamide 12 and the like, and ether components Examples thereof include polyoxytetramethylene glycol, polyoxyethylene glycol, polyoxy-1,2-propylene glycol and the like, but preferably a copolymer containing polytetramethylene glycol and polylauryl lactam (polyamide 12) as main components. It is. Moreover, what used a small amount of dicarboxylic acids, such as dodecane dicarboxylic acid, adipic acid, a terephthalic acid, as an arbitrary component may be used.

  Examples of the polyester elastomers include polyether ester elastomers combining polybutylene terephthalate and polytetramethylene glycol, and polyester ester elastomers combining polybutylene terephthalate and polycaprolactone.

  Resins such as the polyolefins, polyamide elastomers, and polyester elastomers may be used singly or in combination of two or more. At this time, the amount of the resin added is preferably 0.1 to 20% by mass in the polyamide-based resin composition, and more preferably 0.5% by mass or more or 15% by mass or less. More preferably, the ratio is more preferably 1% by mass or more or 10% by mass or less. In such a range, by adding a resin such as polyolefins, polyamide elastomers, and polyester elastomers, flexibility and impact resistance can be imparted without reducing transparency and heat resistance.

(Other ingredients)
As long as the effects of the present invention are not impaired, the resin composition constituting each layer of the multilayer film includes a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, an antibacterial / antifungal agent, an antistatic agent, and a lubricant. Additives such as pigments and dyes can be blended.

<Manufacturing method of this multilayer film>
The multilayer film can be produced by various methods. For example, it can be produced by the following method.

In this multilayer film, all layers may be formed at once by coextrusion, or each layer may be formed individually and then bonded by a general laminating method.
In consideration of the film forming property and the film forming method of each layer, it is preferable that the respective layers are individually formed and then bonded by a general laminating method.

Although it does not specifically limit as a manufacturing method of a film, It can form into a film by general T die-casting method, roll extending | stretching method, tenter extending | stretching method, tubular method, inflation method, etc. Among these, as the molding method for the resin layer (I), it is preferable to select an inflation method from the viewpoint of productivity. Moreover, when a polyamide resin is used as a main component of layers other than the resin layer (I), it is preferable to select a tenter stretching method from the viewpoint of productivity and film forming property.
Thus, the resin layer (I) used for this multilayer film can be obtained by inflation molding, which is advantageous in terms of productivity and cost.

When forming all the layers at once by coextrusion, the coextruded laminated film may be uniaxially or biaxially stretched as necessary. When each layer is formed individually, the monolayer film constituting each layer may be uniaxially or biaxially stretched as necessary.
Under the present circumstances, it is preferable that the draw ratio of a stretched film exists in the range of 1.1-16 times by area magnification. The lower limit of the area magnification is more preferably 1.5 times or more, and further preferably 2 times or more. On the other hand, the upper limit of the area magnification is more preferably 15 times or less, and further preferably 14 times or less. By stretching the film in such a range, the properties such as strength, heat resistance, moisture resistance, and transparency of the multilayer film can be improved.

  In addition, when each layer is formed into a film individually and bonded by a general laminating method, for example, a dry laminating method, a wet laminating method, a sand laminating method using a urethane-based adhesive, an acrylic adhesive, or a polyester-based adhesive. It can be bonded by a laminating method, an extrusion laminating method or the like.

<Physical properties>
The multilayer film preferably has the following physical properties.

(Water vapor transmission rate)
Based on JIS K7129B method, the water vapor transmission rate of this multilayer film at a thickness of 0.07 mm measured at a temperature of 40 ° C. and a relative humidity of 90% is preferably 2.0 g / (m ² · 24 hours) or less, In particular, it is 1.7 g / (m ² · 24 hours) or less, more preferably 1.5 g / (m ² · 24 hours) or less.

(Haze value)
The haze value of the present multilayer film having a thickness of 0.07 mm measured according to JIS K7105 is preferably 20% or less, more preferably 15% or less, and most preferably 13% or less.

<Application>
Various packaging materials can be formed using this multilayer film. In particular, since the multilayer film is excellent in all of moisture resistance, transparency and heat sealability, it can be widely used for packaging materials such as pharmaceuticals and foods.

<Explanation of terms>
In general, “film” refers to a thin flat product whose thickness is extremely small compared to the length and width and whose maximum thickness is arbitrarily limited, and is usually supplied in the form of a roll (Japan). Industrial standard JISK6900). On the other hand, a “sheet” generally refers to a product that is thin by definition in JIS and generally has a flat thickness that is small for the length and width. However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.

  In addition, when expressed as “main component”, unless otherwise specified, when there is one main component, it means a component that occupies 50% (mol%, mass%, volume%) or more of the total component. Yes, when there is no component occupying 50% (mol%, mass%, volume%) or more of the total component, it means the component having the highest content among the total components.

In the present invention, when expressed as “X to Y” (X and Y are arbitrary numbers), “X is preferably greater than X” and “preferably Y”, with the meaning of “X to Y” unless otherwise specified. It means “smaller”.
Further, in the present invention, when expressed as “X or more” (X is an arbitrary number), it means “preferably larger than X” unless otherwise specified, and “Y or less” (Y is an arbitrary number). ) Includes the meaning of “preferably smaller than Y” unless otherwise specified.

  Examples are shown below, but the present invention is not limited by these.

<Evaluation method>
Various measured values and evaluations for the raw materials and test pieces displayed in the following Examples and Comparative Examples were performed as follows. Here, the flow direction from the extruder of the film is called the vertical direction, and the orthogonal direction is called the horizontal direction.

(1) Crystal melting peak temperature (Tm)
Using a differential scanning calorimeter manufactured by Perkin Elmer (trade name “Pyris1 DSC”), according to JIS K7121, about 10 mg of the sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min. The temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min after holding at 1 ° C. for 1 minute, and again from the thermogram measured when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min (Tm ) (° C).

(2) Heat of crystal melting (ΔHm)
Using a differential scanning calorimeter manufactured by Perkin Elmer (trade name “Pyris1 DSC”), according to JIS K7122, about 10 mg of the sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min. After holding at 1 ° C. for 1 minute, the temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min, and again from the thermogram measured when the temperature was raised to 200 ° C. at a heating rate of 10 ° C./min (ΔHm) (J / g) was determined.

(3) Crystallization peak temperature (Tc)
Using a differential scanning calorimeter manufactured by Perkin Elmer (trade name “Pyris1 DSC”), according to JIS K7121, about 10 mg of the sample was heated from −40 ° C. to 200 ° C. at a heating rate of 10 ° C./min. The crystallization peak temperature Tc (° C.) was obtained from the thermogram measured when the temperature was lowered to −40 ° C. at a cooling rate of 10 ° C./min after holding at 1 ° C. for 1 minute.

(4) Softening temperature (Ts)
The softening temperature of the olefin compatible resin (C) was determined according to JIS K2207.

(5) Density According to JIS K7112, the density (g / cm ³ ) of the resin composition (X) described later was determined by a density gradient tube method.

(6) MFR
In accordance with JIS K7210, MFR (g / 10 min) of the resin composition (X) described later was determined under the conditions of a temperature of 190 ° C. and a load of 2.16 kg.

(7) Storage shear modulus (G ')
A resin composition (described later) under the conditions of a temperature of 140 to 220 ° C., a frequency of 1 Hz, a heating rate of 3 ° C./min, and a strain amount of 0.5%, using RDAII (Viscoelasticity Measuring Device Dynamic Analyzer) manufactured by Rheometrics. The storage shear modulus (G ′) of X) was measured. From the obtained results, the value of the storage shear modulus (G ′) at 200 ° C. was read.

(8) Oxygen permeability Based on JIS K7126B, oxygen permeability was measured for a sample having a thickness of 0.07 mm in an atmosphere of 23 ° C and 50% RH using OX-TRAN 2/21 manufactured by MOCON. A sample having an oxygen permeability of 300 ml / (m ² · 24 hours) or less was regarded as acceptable.

(9) Water vapor transmission rate Based on JIS K7129B, the water vapor transmission rate was measured for a sample having a thickness of 0.07 mm in an atmosphere of 40 ° C. and 90% RH using PERMATRAN W 3/31 manufactured by MOCON. A water vapor transmission rate of 2.0 g / (m ² · 24 hours · MPa) or less was regarded as acceptable.

(10) Haze (transparency)
Based on JIS K7105, total light transmittance and diffuse transmittance were measured, and haze was calculated by the following formula. A film having a haze of 15% or less at a thickness of 0.07 mm was regarded as acceptable.
[Haze] = [diffuse transmittance] / [total light transmittance] × 100

(11) Heat seal strength After the layers (II) of the multilayer film sample cut out in the vertical direction of 150 mm and the horizontal direction of 100 mm are combined, the width is 10 mm under the conditions of a pressure of 1 kgf / cm ² , a temperature of 130 ° C., and a sealing time of 1 second. The central part in the vertical direction was heat-sealed in parallel with the horizontal direction of the sample with the heating bar.
Next, the heat-sealed sample was cut out to 150 mm in the vertical direction and 15 mm in the horizontal direction, and then using a tensile tester (material tester 201X with a constant temperature bath manufactured by Intesco), the ambient temperature was 23 ° C., and the peeling rate was 50 mm / min. A 180 ° C. peel test was performed. A film having a peel strength of 10 N / 15 mm or more was accepted.

<Materials used>
[Ethylene polymer (A)]
(A) -1: ethylene copolymer (ethylene / hexene-1 / octene-1 = 95.2 / 3.5 / 1.3 mass%, density = 0.940 g / cm ³ , crystal melting peak temperature = 128 ° C., heat of crystal fusion = 145 J / g, crystallization peak temperature Tc (A) = 113 ° C., MFR = 0.45 g / 10 min, Mw / Mn = 3.56)
(A) -2: Ethylene copolymer (ethylene / butene-1 / octene-1 = 98.3 / 0.4 / 1.3 mass%, density = 0.946 g / cm ³ , crystal melting peak temperature = 129 ° C., heat of crystal fusion = 176 J / g, crystallization peak temperature Tc (A) = 110 ° C., MFR = 1.3 g / 10 min, Mw / Mn = 3.14)
(A) -3: ethylene homopolymer (ethylene = 100% by mass, density = 0.958 g / cm ³ , crystal melting peak temperature = 134 ° C., heat of crystal melting = 207 J / g, crystallization peak temperature Tc (A) = 115 ° C, MFR = 1 g / 10 min, Mw / Mn = 4.72)
(A) -4: Ethylene copolymer (ethylene / hexene-1 = 87.9 / 12.1% by mass, density = 0.918 g / cm ³ , crystal melting peak temperature = 121 ° C., heat of crystal melting = 134 J / G, crystallization peak temperature Tc (B) = 105 ° C., MFR = 4 g / 10 min, Mw / Mn = 2.80)
(A) -5: Ethylene copolymer (ethylene / butene-1 / octene-1 = 97.7 / 1.1 / 1.2 mass%, density = 0.941 g / cm ³ , crystal melting peak temperature = 127 ° C., heat of crystal fusion = 162 J / g, crystallization peak temperature Tc (A) = 114 ° C., MFR = 2.5 g / 10 min, Mw / Mn = 3.12)

[Nucleating agent (B)]
(B) -1: fatty acid metal salt (zinc stearate / 1,2-cyclohexanedicarboxylic acid calcium salt = 34/66 mass%)

[Olefin compatible resin (C)]
(C) -1: Hydrogenated petroleum resin (trade name “Arcon P115” manufactured by Arakawa Chemical Industries, Ltd., softening temperature Ts (C) = 115 ° C.)

[Polyamide resin (D)]
(D) -1: Product name Novamid 1022C6 (polyamide 6) manufactured by Mitsubishi Chemical Engineering Plastics Co., Ltd.
(D) -2: Mitsubishi Chemical Engineering Plastics Co., Ltd. trade name MX nylon S6007 (polyamide MXD6, polymetaxylylene adipamide (metaxylenediamine / adipic acid = 50.5 / 49.5 mol%))

[EVOH (E)]
(E) -1: Nippon Synthetic Chemical Industry Co., Ltd. product name Soarnol DC3203FB (EVOH, ethylene content: 32 mol%, saponification degree: 99.5 mol%)

Example 1
(A) -1, (B) -1, and (C) -1 were dry blended at a mixing mass ratio of 79.9: 0.1: 20 and then charged into a Φ25 mm co-directional twin screw extruder. The mixture was melt-kneaded at a set temperature of 220 ° C. and then extruded from a strand-shaped die. Subsequently, after cooling in a water tank, it was cut into pellets to obtain a resin composition (X).
The pellets of the resin composition (X) thus obtained were measured for density, heat of crystal fusion (ΔHm), MFR, and storage shear modulus (G ′).

  The pellets of the resin composition (X) obtained as described above were put into a Φ30 mm single screw extruder, melted and kneaded at a set temperature of 200 ° C., and then set at a set temperature of 200 ° C. and a blow ratio of 3.5 from an annular die. Inflation molding was performed under the conditions to obtain a film (Y) having a thickness of 0.05 mm.

On the other hand, the resin composition comprising (D) -1 was melt-kneaded at 270 ° C. using a Φ65 mm single screw extruder, then extruded from a T-die die, and then rapidly cooled with a cast roll at 30 ° C., so that the thickness was 0 An unstretched monolayer film of 133 mm was obtained.
Next, the obtained unstretched monolayer film was stretched 3 times in the longitudinal direction by a roll-type stretching machine heated to 60 ° C., and then this longitudinally stretched film was stretched in the transverse direction by a tenter-type lateral stretching machine heated at 100 ° C. The film was stretched 3.5 times. Next, the film (Z) having a thickness of 0.015 mm is obtained by heat-fixing at 215 ° C., performing 20% relaxation in the transverse direction, cooling to 180 ° C., and performing 5% re-lateral stretching. Obtained.

Next, the one side of the film (Y) is subjected to corona treatment to a wetness index of 50 dyne / cm or more, the following adhesive is applied to the one side with a gravure coat, dried at 70 ° C. to remove ethyl acetate, An adhesive coating layer having a thickness of 0.005 mm was formed.
The adhesive applied at this time uses the trade name TM-329 manufactured by Toyo Morton Co., Ltd. as the main agent, the trade name CAT-8B manufactured by Toyo Morton Co., Ltd. as the curing agent, and ethyl acetate as the diluting solvent. , TM-329, CAT-8B and ethyl acetate are mixed at a mixing mass ratio of 13.8 / 13.8 / 72.4.

Next, the film (Z) is overlaid on the film (Y) coated with an adhesive, and after being dry laminated at 90 ° C. and bonded together, the film is aged at 40 ° C. for 24 hours, so that the thickness is 0.07 mm. A multilayer film was prepared.
About the obtained multilayer film, oxygen permeability, water vapor permeability, haze, and heat seal strength were evaluated. The results are shown in Table 1.

(Example 2)
In Example 1, a multilayer film was prepared and evaluated in the same manner as in Example 1 except that (A) -2 was used instead of (A) -1. The results are shown in Table 1.

(Example 3)
Example 1 is the same as Example 1 except that the mixing mass ratio of (A) -1, (B) -1 and (C) -1 is changed to 89.9: 0.1: 10. The multilayer film was prepared and evaluated by the method described above. The results are shown in Table 1.

Example 4
Using (D) -1 and (D) -2, co-extruded with a multi-layer film consisting of three layers (D) -1 / (D) -2 / (D) -1, and then casted at 30 ° C. Quench rapidly to obtain an unstretched multilayer film having a thickness of (D) -1 / (D) -2 / (D) -1 = 0.053 / 0.027 / 0.053 mm (total thickness = 0.133 mm). It was.
Next, the obtained unstretched multilayer film was stretched and heat-set under the same conditions as in Example 1, and the thickness was (D) -1 / (D) -2 / (D) -1 = 0.006 /. A film (Z) having a thickness of 0.003 / 0.006 mm (total thickness = 0.015 mm) was obtained.

Next, the film (Y) produced in the same manner as in Example 1 was bonded in the same manner as in Example 1 to obtain a multilayer film having a thickness of 0.07 mm.
Evaluation similar to Example 1 was performed about the obtained multilayer film. The results are shown in Table 1.

(Example 5)
In Example 4, when producing a film (Y), the mixing mass ratio of (A) -1, (B) -1, and (C) -1 is changed to 79.9: 0.2: 20. At the same time, a multilayer film was produced in the same manner as in Example 4 except that (D) -2 was replaced with (E) -1 when producing the film (Z).
The obtained multilayer film was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In Example 1, a multilayer film was produced and evaluated in the same manner as in Example 1 except that the film (Y) was produced only from (A) -1. The results are shown in Table 1.

(Comparative Example 2)
In Example 1, when producing the film (Y), Example 1 except that (A) -1 and (B) -1 were dry blended at a mixing mass ratio of 99.9: 0.1. A multilayer film was prepared and evaluated in the same manner as described above. The results are shown in Table 1.

(Comparative Example 3)
In Example 1, when producing a film (Y), the same method as Example 1 except that (A) -1 and (C) -1 were dry blended at a mixing mass ratio of 80:20. A multilayer film was prepared and evaluated. The results are shown in Table 1.

(Comparative Example 4)
In Example 1, when producing a film (Y), (A) -3 was used instead of (A) -1, and (A) -3, (B) -1 and (C) -1 were A multilayer film was prepared and evaluated in the same manner as in Example 1 except that dry blending was performed at a mixing mass ratio of 79.9: 0.1: 20. The results are shown in Table 1.

(Comparative Example 5)
In Example 1, when producing a film (Y), (A) -4 was used instead of (A) -1, and (A) -4, (B) -1, and (C) -1 were mixed. A multilayer film was prepared and evaluated in the same manner as in Example 1 except that dry blending was performed at a mass ratio of 79.9: 0.1: 20. The results are shown in Table 1.

(Comparative Example 6)
In Example 1, when producing a film (Y), (A) -5 was used instead of (A) -1, and (A) -5, (B) -1, and (C) -1 were mixed. After dry blending at a mass ratio of 79.9: 0.1: 20, inflation molding was performed in the same manner as in Example 1. However, the stability of the bubbles was poor, and a film could not be produced.

  In Examples 1 to 5, both oxygen and water vapor barrier properties were excellent, the haze was small, the transparency was excellent, and the heat sealability was excellent. Particularly, as the film (Z), Example 4 provided with a layer made of polyamide MXD6 and Example 5 provided with a layer made of EVOH showed extremely excellent oxygen permeability.

On the other hand, Comparative Example 3 not containing the nucleating agent (B) had insufficient water vapor permeability and insufficient transparency. Moreover, the comparative example 2 which does not contain an olefin compatible resin (C) was inadequate in moisture-proof property and heat seal intensity | strength. Furthermore, Comparative Example 1 lacking both the crystal nucleating agent (B) and the olefin-compatible resin (C) had insufficient moisture resistance, transparency, and heat sealability.
In addition, Comparative Example 4 and Comparative Example 5 in which the condition (i) and the condition (ii) in the resin composition (X) are out of the scope of the present invention are any one of moisture resistance, transparency, and heat sealability. More than one was insufficient.

Claims (8)

One or more selected from the group consisting of ethylene polymer (A), nucleating agent (B), petroleum resin, terpene resin, coumarone-indene resin, rosin resin, and hydrogenated derivatives thereof. A multilayer film comprising a resin layer (I) containing an olefin-compatible resin (C) comprising a combination, and a layer other than the resin layer (I),
The ethylene-based polymer (A) is a copolymer of ethylene, 1-hexene and 1-octene, or a copolymer of ethylene, 1-butene and 1-octene,
The “ other layers other than the resin layer (I)” is a layer comprising at least one layer containing a polyamide-based resin and / or a saponified ethylene-vinyl acetate copolymer,
The multilayer film, wherein the resin layer (I) satisfies the following conditions (i) to (iii):
Condition (i): Density is 0.940 g / cm ^{3 to} 0.960 g / cm ³
Condition (ii): heat of crystal fusion (ΔHm) is 120 J / g to 160 J / g
Condition (iii): Storage shear modulus (G ′) at 200 ° C. is 2,000 Pa to 50,000 Pa   The multilayer film according to claim 1, comprising the resin layer (I) as an outermost layer. The multilayer film according to claim 1 or 2, wherein the resin layer (I) further satisfies the following condition (iv).
Condition (iv): MFR measured at a temperature of 190 ° C. and a load of 2.16 kg is 0.1 g / 10 min to 5.0 g / 10 min.   The content of the nucleating agent (B) in the resin layer (I) is 0.01 to 3.0% by mass, and the content of the olefin-compatible resin (C) is 5 to 30% by mass. Item 4. The multilayer film according to any one of Items 1 to 3.   Crystallization peak at which the softening temperature Ts (C) of the olefin compatible resin (C) measured based on JIS K2207 is measured at a cooling rate of 10 ° C./min in the differential scanning calorimetry of the ethylene polymer (A). It is temperature Tc (A) +15 degrees C or less, The multilayer film in any one of Claims 1-4. Based on JIS K7129B method, the water vapor permeability of the multilayer film at a thickness of 0.07 mm measured at a temperature of 40 ° C. and a relative humidity of 90% is 2.0 g / (m ² · 24 hours) or less. The multilayer film in any one of Claims 1-5.   The multilayer film according to any one of claims 1 to 6, wherein a haze value of the multilayer film at a thickness of 0.07 mm measured based on JIS K7105 is 10% or less. The packaging material formed using the multilayer film in any one of Claims 1-7 .