JP2018176605A - Laminate for liquid packaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyethylene resin which is optimal for an intermediate layer raw material of a multilayer packaging film having a wide filling temperature range, excellent liquid high speed filling property, and excellent rigidity and pressure-resistance strength, and a multilayer packaging film for the same.SOLUTION: There is provided a laminate in which an intermediate layer (B) containing the following ethylene-α-olefin copolymer (X) and a sealant layer (C) are brought into at least partial contact with each other: in the laminate, the ethylene-α-olefin copolymer (X) is a copolymer of ethylene having the following (x1) to (x3) characteristics and α-olefin having 3 to 20 carbon atoms; (x1) a melt flow rate (MFR of 2.16) measured at 190°C and a load of 2.16 kg of 1-50 g/10 min, (x2) a density of 900-925 kg/m, and (x3) a quantity of heat of fusion at 120°C or higher of a melting peak determined by DSC measurement of 10 J/g or more.SELECTED DRAWING: None

Description

  The present invention relates to a laminate applied to a multilayer packaging film and a liquid packaging bag using the laminate.

  Conventionally, a multilayer packaging film consisting of a laminate in which a sealant layer is laminated on a substrate via an intermediate layer is used for packaging of a liquid, a viscous material, or a liquid or viscous material containing insolubles. A liquid packaging bag is known which is filled with liquid or the like from the inlet of the bag-like material and closed by heat sealing.

  In many cases, the packaging bag is produced by heat sealing the film in three or four directions, and in the case of high-speed filling of the liquid etc., the liquid may leak from the heat seal portion. Therefore, a laminate for a packaging bag has been proposed in which the high-speed filling property is enhanced.

  Patent documents 1 to 3 show specific materials having high viscosity at low shear rate and low viscosity at high shear rate, when used as a packaging bag for liquids and mucilages in an automatic filling machine, ie, actual Disclosed is a method of using a resin composition in which the ratio of high shear rate to low shear rate measured at a temperature close to the time of filling is in a specific range. In particular, in the intermediate layer between the substrate and the sealant layer, a composition of a copolymer of ethylene and a C6 alpha-olefin and high pressure low density polyethylene is used.

  According to Patent Document 4, in a packaging material having at least one sealant layer on a substrate film, the sealant layer comprises an interlayer comprising an ethylene-α-olefin copolymer and a crystal nucleating agent and an ethylene-α-olefin copolymer A packaging material comprising an innermost layer comprising: an intermediate layer having a melting point of 90 to 120 ° C., a crystallization temperature of 80 to 110 ° C., and a difference between the melting point and the crystallization temperature of 25 ° C. or less is preferred It is done.

  Furthermore, Patent Document 5 is a polyethylene resin composition comprising a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and high-pressure low-density polyethylene (HPLD), and has a specific density, MFR, The use of compositions having specific elution characteristics for o-dichlorobenzene is disclosed.

JP, 2012-139848, A Unexamined-Japanese-Patent No. 2012-139849 JP 2012-139854 A JP 10-315409 A JP 2007-204628 A

  However, conventionally, the possible temperature range for filling has been narrow, and many product defects have occurred due to variations in seal portion temperature at the time of filling.

  The present invention provides a polyethylene-based resin suitable as an intermediate layer material of a multilayer packaging film having a wide fillable temperature range, high-speed filling of excellent liquid, excellent rigidity, and pressure resistance, or the multilayer packaging film thereof The purpose is to provide.

  The above object is achieved by reducing the heat absorption amount of the intermediate layer portion using a polyethylene resin used as the intermediate layer of the multilayer packaging film as a resin having a wide melting point distribution and increasing the amount of heat transfer to the sealant layer. .

That is, the present invention
[1] A laminate characterized in that an intermediate layer (B) containing the following ethylene / α-olefin copolymer (X) is in contact with at least a part of a sealant layer (C):
The ethylene / α-olefin copolymer (X) is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, which has the following properties (x1) to (x3):
(X1) Melt flow rate (MFR 2.16) measured at 190 ° C. under 2.16 kg load is 1 to 50 g / 10 min,
(X2) The density is 900 to 925 kg / m ³ ,
(X3) The heat of fusion at 120 ° C. or higher is 10 J / g or more, of the melting peak determined by DSC measurement.
[2] The substrate layer (A) is in contact with the intermediate layer (B) at least in part,
The sealant layer (C) contains an ethylene / α-olefin copolymer (Y) which is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, which satisfies the following requirements (y1) to (y2) The laminate according to [1], which is characterized by:
(Y1) Melt flow rate (MFR 2.16) measured at 190 ° C. under 2.16 kg load is 1 to 50 g / 10 min,
(Y2) The density is 880 to 920 kg / m ³ .
[3] The base material layer (A) is a polyamide resin, a polyester resin, a polyolefin resin, a polyvinylidene chloride resin, a saponified ethylene-vinyl acetate copolymer, a polycarbonate resin, a polystyrene resin or a stretched product thereof, metal foil The laminate according to [2], which contains, as a substrate, at least one selected from inorganic oxide vapor-deposited films, paper, and non-woven fabrics.
[4] The substrate layer (A) has at least a portion thereof laminated with one or more adhesives selected from polyurethane, isocyanate compound, polyester or a mixture of polyol or isocyanate and isocyanate compound and reaction product The laminate according to [2] or [3], which is characterized by containing
[5] A liquid packaging bag using the above laminate as a packaging material.

  By expanding the fillable temperature range of the multilayer packaging film, filling can be performed in a wider temperature range than conventional products. As a result, the tolerance for variations in the temperature of the sealing portion at the time of filling increases, which leads to a reduction in the percentage of defective products.

The filling form of the multilayer packaging film seals in a very short time and can not be filled unless adhesion of the seal portion occurs before the temperature of the sealant layer reaches the temperature of the seal bar. Therefore, if the heat conductivity of the intermediate layer is good, filling can be performed even if the temperature of the seal bar is low. That is, the temperature range which can be filled becomes wide. In order to improve the heat conductivity of the intermediate layer, it is necessary to reduce the amount of components melted at the melting point of the sealant layer resin of the intermediate layer resin.
However, when the intermediate layer resin is higher than the melting point of the sealant layer resin and a resin having a narrow distribution of the melting point is used, the resin density of the intermediate layer itself becomes high, and the rigidity is too high. Since it leads to the seal failure of the part, the filling failure occurs.
Therefore, by changing the polyethylene resin used as the intermediate layer to a resin having a wide melting point distribution, the heat absorption amount of the intermediate layer portion is decreased without increasing the rigidity of the intermediate layer resin so much, and the heat transfer amount to the sealant layer is increased. It becomes possible.

Hereinafter, embodiments of the present invention will be described.
In the present invention, the laminate includes the intermediate layer (B) and the sealant layer (C) as the minimum essential structural units, and further, the surface opposite to the surface on which the sealant layer (C) is formed. A multilayer packaging film can be constructed by laminating on the middle layer (B) of the above. Hereinafter, although the packaging material which consists of a multilayer packaging film is demonstrated as embodiment example, the laminated body of this invention is not limited only to a multilayer packaging film.

1. Packaging Material The packaging material of the present embodiment is a multilayer packaging film in which at least a laminate of a base material layer (A), an intermediate layer (B) or a sealant layer (C) is laminated. The intermediate layer (B) may be formed entirely between the base material layer (A) and the sealant layer (C), and may be formed in a part near the portion to be heat sealed when forming into a bag shape. .

<Base material layer (A)>
In the present embodiment, the base material constituting the base material layer (A) is a material having relatively high rigidity and strength, which is one outer surface of the packaging material. Specifically, polyamide resins such as nylon 11 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene resin and polypropylene resin, polystyrene resin, polyvinylidene chloride resin, polycarbonate resin, ethylene- Vinyl acetate copolymer saponified products, thermoplastic resins such as acrylic resins or stretched products thereof, inorganic oxide vapor deposited films, metal vapor deposited films ceramic vapor deposited films or metal foils, paper, non-woven fabrics and laminates thereof There is one kind.

  The metal foil is not particularly limited depending on the material, thickness and the like, and aluminum foil, tin foil, lead foil, galvanized thin-layer steel plate, 5 to 50 μm thick, ionized metal thin film by electrolysis, iron foil Etc. are used.

  The metal vapor deposition film is not particularly limited depending on the material, thickness and the like, and examples of the vapor deposition metal include aluminum and zinc, and a thickness of 0.01 to 0.2 μm is preferably used. The deposition method is also not particularly limited, and known methods such as vacuum deposition, ion plating and sputtering may be used. Furthermore, in the ceramic vapor deposition film, as the ceramic to be deposited, for example, metal such as glass, alumina, magnesium oxide, tin oxide, etc. in addition to silicon oxide represented by the general formula SiOx (0.5 ≦ x ≦ 2) And metal fluorides such as oxides, fluorite and selenium fluoride. The metal oxide may contain trace metals, other metal oxides, and metal hydroxides. Deposition can also be performed by applying the various deposition methods described above to at least one side of the film. The thickness of the vapor deposition film is usually about 10 to 50 μm. Moreover, there is no restriction | limiting in particular as a vapor deposition film, Transparent films, such as an oriented polyester film, a polypropylene film, a polyamide film, are mentioned.

  In addition, at the contact surface of the base material layer (A) with the intermediate layer (B), at least one adhesive selected from polyurethane, isocyanate compound, polyester or a mixture of polyol or isocyanate and isocyanate compound and reaction product is used It is preferable to laminate | stack on material and to improve the adhesiveness of a base material layer (A) and an intermediate | middle layer (B).

  Thus, the base material layer (A) of the present embodiment includes a resin layer and / or a metal layer containing an element selected from heteroatoms such as oxygen and nitrogen, and metals.

<Intermediate layer (B)>
The intermediate layer (B) is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin copolymer (X) or copolymer having the following properties (x1) to (x3) (X)) is included.
(X1) Melt flow rate (MFR 2.16) measured at 190 ° C. under 2.16 kg load is 1 to 50 g / 10 min,
(X2) The density is 900 to 925 kg / m ³ ,
(X3) The heat of fusion at 120 ° C. or higher is 10 J / g or more, of the melting peak determined by DSC measurement.

  The melt flow rate (MFR 2.16) in (x1) is measured at 190 ° C. under a load of 2.16 kg in accordance with JIS K 7210-1. The MFR 2.16 is in the range of 1 to 50 (g / 10 min), preferably 3 to 30 (g / 10 min), and more preferably 4 to 20 (g / 10 min). The extrusion processability at the time of intermediate | middle layer formation improves that MFR 2.16 exists in the said range.

The density at (x2) is measured in accordance with JIS K7112. The density is 900 to 925 kg / m ³ , preferably 910 to 925 kg / m ³ .

  The heat of fusion at (x3) indicates the heat of fusion of 120 ° C. or more at the melting peak measured by DSC (differential scanning calorimetry), and the heat of fusion is 10 J / g or more. Generally, the melting peak of low density polyethylene shows an endothermic peak having a plurality of peaks from around 30 ° C. and is broad as compared to high density polyethylene. Usually, the highest peak temperature of the melting peak is the melting point. The DSC measurement was performed under the conditions shown in the following examples.

  The copolymer (X) is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and a copolymer of ethylene and an α-olefin having 4 to 8 carbon atoms is preferable.

  The copolymer (X) is prepared using a catalyst for olefin polymerization such as metallocene, titanium, chromium and phenoxy imine. The copolymer (X) may be linear or branched low density polyethylene. In particular, preparation using a metallocene-based olefin polymerization catalyst results in a polymer having a narrow molecular weight distribution, so that the formation of components having low molecular weight and low density is small, which is effective for use in connection with the present invention.

  The metallocene catalyst generally comprises a metallocene catalyst component (a1) comprising a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton, an organoaluminum oxy compound catalyst component (b) And a particulate carrier (c), and optionally an organoaluminum compound catalyst component (d) and an ionizing ionic compound catalyst component (e).

  Such copolymers (X) are, for example, metallocenes described in JP-A-6-9724, JP-A-6-136195, JP-A-6-136196, JP-A-6-207057, etc. It can be produced by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a so-called metallocene olefin polymerization catalyst containing a catalyst component.

  The copolymer (X) may be used alone or in combination of two or more, and the combination may satisfy the above (x1) to (x3). The copolymer (X) can also select the material which satisfy | fills said (x1)-(x3) from the ethylene-alpha-olefin copolymer marketed.

<Sealant layer (C)>
The sealant layer (C) may be a conventionally known sealant layer, but it is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, which satisfies the following requirements (y1) to (y2): It is preferable to use an α-olefin copolymer (Y).
(Y1) Melt flow rate (MFR 2.16) measured at 190 ° C. under 2.16 kg load is 1 to 50 g / 10 min,
(Y2) The density is 880 to 920 kg / m ³ .
In view of the heat sealability at a lower temperature, the ethylene / α-olefin copolymer (Y) constituting the sealant layer (C) is the ethylene / α-olefin copolymer constituting the intermediate layer (B) It is preferred to have a melting point lower than (X).

  The ethylene / α-olefin copolymer (Y) is prepared using a catalyst for olefin polymerization such as metallocene, titanium, chromium and phenoxy imine. The low density ethylene / α-olefin copolymer may be linear or branched low density polyethylene. In particular, a polymer having a narrow molecular weight distribution is obtained when it is prepared using a metallocene-based olefin polymerization catalyst, so that the formation of components having low molecular weight and low density is small, which is effective for the use according to the present invention.

  The metallocene catalyst generally comprises a metallocene catalyst component (a1) comprising a transition metal compound of Group IVB of the periodic table having at least one ligand having a cyclopentadienyl skeleton, an organoaluminum oxy compound catalyst component (b) And a particulate carrier (c), and optionally an organoaluminum compound catalyst component (d) and an ionizing ionic compound catalyst component (e).

  Such ethylene / α-olefin copolymers (Y) are disclosed, for example, in JP-A-6-9724, JP-A-6-136195, JP-A-6-136196 and JP-A-6-207057. It can be produced by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a so-called metallocene olefin polymerization catalyst containing the metallocene catalyst component described.

  The ethylene / α-olefin copolymer (Y) may be used alone or in combination of two or more, and even if one or more of the ethylene / α-olefin copolymer is combined with one or more of other polyethylenes. Good. A commercial item satisfying the above (y1) and (y2) can also be used.

  The resin (resin composition) constituting the intermediate layer (B) and the laminate layer (C) is, if necessary, a conventionally known antiblocking agent, antifogging agent, antistatic agent, antioxidant, weathering stability Additives, such as an agent, a heat stabilizer, and a lubricant can be blended in the range which does not impair the object of the present invention.

  Such a resin composition is obtained by mixing at normal temperature to 250 ° C. using a mixing apparatus such as a Banbury mixer, a Henschel mixer, a V-type blender and an extruder together with the above-mentioned additive. At this time, by carrying out nitrogen seal or vacuum seal, it is possible to prevent the generation of gel derived from the deterioration of polyethylene.

<Production of laminates>
In the present invention, the intermediate layer (B) is brought into contact with the base layer (A) in a molten state to form a laminate, whereby the base layer (A) and the intermediate layer (B) are A laminate having excellent adhesion can be obtained. Contact of the intermediate layer (B) in the molten state can be carried out by melt-extrusion of the intermediate layer on the substrate. Moreover, when setting it as a multilayer packaging film, it can melt-extrude and shape | mold and manufacture the resin composition used for the said intermediate | middle layer and a sealant layer separately or simultaneously.

  The molding temperature of the intermediate layer and the sealant layer is preferably 150 to 320 ° C., and in this range, the adhesion between the substrate and the intermediate layer, and between the intermediate layer and the sealant layer is improved.

  In addition, when the intermediate layer (B) is melt-extruded on the base material layer (A), the surface on which the intermediate layer (B) of the base material layer (A) is extrusion-formed is subjected to anchor coating treatment, and It is preferable from the viewpoint of adhesiveness that the treatment (hereinafter referred to as the ozone treatment) is performed in an oxidizing atmosphere (for example, a gas containing air such as oxygen (in particular, air)) in a molding temperature range. The anchor coat treatment is performed using polyurethane, an isocyanate compound, a urethane polymer, or a mixture and reaction product thereof, a mixture or reaction product of a polyester or a polyol and an isocyanate compound, or a known anchor coat agent such as a solution thereof, an adhesive, etc. Is applied to the substrate surface.

  In the laminate of the present invention, each of the base layer (A), the intermediate layer (B), and the sealant layer (C) has a total of three layers each consisting of one layer, which is a basic configuration as a multilayer packaging film. Here, each layer of the base material layer (A), the intermediate layer (B) and the sealant layer (C) may be a single layer, but in some cases, each layer can be composed of a plurality of layers. For example, a two-layer film in which a polyester film and a ceramic vapor-deposited polyester film are dry laminated can be used as the substrate layer (A). In the case where one intermediate layer and one sealant layer are laminated on a base material layer (A) composed of a two-layer film, a total of four layers are laminated. In addition, for example, a total three-layer film in which a polyester film and an aluminum foil are dry-laminated and further a polyester film is dry-laminated on the aluminum foil surface is used as a base layer (A). The intermediate layer (B) and the sealant layer (C) are usually used in a single layer (only one layer). In the present invention, as long as the intermediate layer (B) and the sealant layer (C) are at least partially in contact with each other, another layer may be present between the two. In addition, the base material layer (A) may be at least partially in contact with the laminate of the intermediate layer (B) and the sealant layer (C), and in particular, the base material layer (A) / intermediate in the portion to be heat sealed It may be a laminated structure of layer (B) / sealant layer (C). Another layer may be present between the substrate layer (A) and the intermediate layer (B) in the other part, and the substrate layer (A) and the sealant layer (C) do not intervene the intermediate layer (B) There may be a portion in contact with the As other layers, other olefin polymers other than the intermediate layer (B) and the sealant layer (C), an air layer, etc. may be mentioned.

The ozone treatment is carried out by directing a gas (such as air) containing ozone from the nozzle or slit-like outlet in the air gap to the substrate adhesion surface of the intermediate layer or the substrate surface laminated with this, or both It is performed by spraying toward the crimped portion. In addition, when extruding and laminating at a speed of 100 m / min or more, it is preferable to spray toward the above-mentioned pressure-bonding parts of both. The concentration of ozone in the gas containing ozone is preferably 1 g / m ³ or more, more preferably 3 g / m ³ or more. The amount sprayed is preferably 0.03 liter / min / cm or more, more preferably 0.1 liter / min / cm or more, relative to the width of the intermediate layer.

  The laminating speed is generally 100 to 150 m / min in terms of productivity. The air gap of the known extrusion laminator is generally 100 to 150 mm. From the viewpoint of adhesiveness, it is preferable that the laminate in the present invention be subjected to an aging treatment immediately after molding. Aging is performed by standing for 12 to 24 hours in an atmosphere of 0 to 50% humidity at a temperature of 23 to 45 ° C., preferably 35 to 45 ° C., within 12 hours after molding of the laminate.

  The laminate thus obtained has a thickness of 10 to 50 μm for the substrate layer (A), a thickness of 10 to 50 μm for the intermediate layer (B), and a thickness of 5 to 100 μm for the sealant layer (C). It is common to have.

<Liquid packaging bag>
The packaging material of the present invention is particularly useful as a liquid packaging bag filled with a liquid or a viscous material, and a laminate obtained by laminating the above-mentioned base material layer (A) / intermediate layer (B) / sealant layer (C) in order One or two pieces of the multilayer packaging film) are formed into a bag shape by two-way sealing, three-way sealing or four-way sealing with a conventional heat sealing machine. The shape of the bag is generally rectangular, but can be any shape.

  The heat sealing is performed at a temperature equal to or higher than the melting temperature of the sealant layer (C), and the heat sealing width may be appropriately set in accordance with the amount of the liquid to be filled in the liquid packaging bag. Also, in order to facilitate removal of the liquid from the bag, it is possible to heat seal leaving a portion to be the spout.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to only these examples.

(Copolymer for interlayer)
An ethylene-α-olefin copolymer shown in Table 1 was prepared.

Example 1
<Film forming method of liquid packaging bag>
The laminate film was prepared by an extrusion laminating method. Film formation was performed using an extrusion laminating apparatus in which the temperature of the resin extruded from the T-die of an extruder with a bore diameter of 60 mm was set to 295 ° C. Processing was performed with a cooling roll surface temperature of 30 ° C., a die width of 500 mm, and a die lip opening degree of 0.9 mm, and the extrusion amount was adjusted so that the coating thickness was 25 μm when the processing speed was 80 m / min. A polyurethane anchor coating agent (Mitsui Chemical Co., Ltd., polyol component: Takelac (registered trademark) on a biaxially stretched nylon film (Toyobo, "Harden (registered trademark) ONY # 15") having a width of 500 mm and a thickness of 15 μm. A) A-3210 ", Isocyanate component:" Takenate (registered trademark) A-3075 ") is coated with a gravure roll, and while spraying ozone in the laminating section there, PE-1 is used as an intermediate layer material, Extrusion lamination was performed at a take-up speed of 80 m / min and a coating thickness of 25 μm. Furthermore, using the same extrusion laminating apparatus, made by Prime Polymer Co., Ltd., trade name "Evolue P SP 05156C" (MFR: 12 g / 10 min, density: 904 kg / m ³ ), extrusion resin temperature 295 ° C., take-up speed 80 m / min Then, extrusion lamination was performed with a coating thickness of 25 μm to perform lamination. The processed laminated film was aged for 24 hours in an oven at 40 ° C., and then slit into a width of 150 mm to obtain a packaging film for evaluation.
The physical properties of the mid layer resin and the liquid filling aptitude for the obtained packaging film were evaluated. The results are shown in Table 2.

Example 2
The physical properties of the blend resin and the liquid filling aptitude of the obtained packaging film were evaluated in the same manner as in Example 1 except that PE-1 and PE-2 were used at a weight ratio of 50:50 as the interlayer resin. The results are shown in Table 2.

Comparative Examples 1 and 2
The physical properties of the blend resin and the liquid filling aptitude of the obtained packaging film were evaluated in the same manner as in Example 1 except that PE-3 and PE-4 were used as the interlayer resin, respectively. The results are shown in Table 2.

<Melt flow rate (MFR)>
According to JIS K 7210-1, it measured on the conditions of 190 degreeC and 2.16 kg load.

<Density (D)>
In accordance with JIS K7112, the strand obtained at the time of MFR measurement was heat-treated at 100 ° C. for 1 hour, and left at room temperature for 1 hour, and then measured by the density gradient tube method.

<Melting point peak, heat of fusion>
The crystal melting point can be determined by measurement under the following measurement conditions using a differential scanning calorimeter (DSC, manufactured by Perkin Elmer (Diamond DSC)) according to JIS K7121. The apex of the endothermic peak in the third step when measurement was performed under the following measurement conditions was defined as the crystal melting point (Tm). When there are a plurality of endothermic peaks, the endothermic peak apex at which the peak height is maximum is defined as the crystal melting point (Tm).
(Measurement condition)
Measurement environment: Nitrogen gas atmosphere Sample amount: 5 mg
Sample shape: Pressed film (230 ° C molding, thickness 400μm)
Sample pan: Aluminum sample pan with flat bottom: 1st step: Increase temperature from 0 ° C to 200 ° C at 10 ° C / min and hold for 10 min.
Second step: The temperature is lowered to 0 ° C. at 10 ° C./min.
Third step: The temperature is raised to 200 ° C. at 10 ° C./min.
<On the measuring method of heat of fusion>
A baseline is drawn in the region of 135 ° C. to 160 ° C. in each heat of fusion curve, and the value of the baseline is subtracted from the heat of fusion curve to make the remaining area the heat of fusion.
The total heat of fusion of the melting peak was taken as the heat of fusion A, and the heat of fusion at 120 ° C. or higher was taken as the heat of fusion B, and the B / A ratio was determined.

<Method of filling liquid packaging bag and evaluation of liquid filling suitability>
The liquid was filled using a high-speed automatic filling and packaging machine (DANGAN TYPE-III, manufactured by Taisei Ramic Co., Ltd.) under the following conditions to obtain a liquid filled pouch.

[Filling conditions]
Seal temperature: (longitudinal) 190 ° C, (horizontal) 140 ° C to 185 ° C in 5 ° increments Package type: Three-way seal Bag size: Width 75mm × length 85mm pitch Filling: water at 23 ° C Filling amount: about 24cc
Filling speed: 25 m / min The appearance observation and pressure resistance test of the transversely sealed portion of the obtained liquid filled pouch were conducted, and evaluation was made according to the following criteria.

[Appearance of seal part: Evaluation of high temperature filling aptitude (foaming start temperature)]
Evaluation was made at the lowest temperature at which the lateral seal starts to foam. It is desirable that the foaming start temperature be high.
○: No large poly reservoir or foam generation Δ: Leakage in the seal area ×: Large poly reservoir or foam generation [pressure resistance test condition: judgment criteria for low temperature filling aptitude (minimum pressure temperature)]
A load of 100 kg was applied to the bag after filling with a pressure resistance tester (manufactured by Komatsu Seisakusho) for 1 minute, and a pressure resistance test was performed to evaluate the minimum temperature at which no bag breakage or water leakage occurs. It is desirable that the lowest withstand temperature be low.
○: Withstand pressure 100 kg, no problem for 1 minute :: Leakage from half-folded part ×: Receding of horizontal seal

  As apparent from Table 2, since the laminate according to the present invention uses the ethylene / α-olefin copolymer (X) according to the present invention as an intermediate layer material, the fillable temperature range is wide and excellent It showed high speed filling of the liquid. In Comparative Example 1, by not satisfying the condition (x3) as the intermediate layer material, the fillable temperature range was narrowed as compared with Examples 1 and 2. In Comparative Example 2, since the thermal melting peak was not shown at 120 ° C. or higher, the pressure resistance deteriorated, and there was no fillable temperature range at 140 to 185 ° C.

Claims (5)

A laminate characterized in that an intermediate layer (B) containing the following ethylene / α-olefin copolymer (X) and a sealant layer (C) are in contact at least in part:
The ethylene / α-olefin copolymer (X) is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, which has the following properties (x1) to (x3):
(X1) Melt flow rate (MFR 2.16) measured at 190 ° C. under 2.16 kg load is 1 to 50 g / 10 min,
(X2) The density is 900 to 925 kg / m ³ ,
(X3) The heat of fusion at 120 ° C. or higher is 10 J / g or more, of the melting peak determined by DSC measurement. The base layer (A) is further in contact with the intermediate layer (B) at least in part,
The sealant layer (C) contains an ethylene / α-olefin copolymer (Y) which is a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, which satisfies the following requirements (y1) to (y2) The laminate according to claim 1, characterized in that:
(Y1) Melt flow rate (MFR 2.16) measured at 190 ° C. under 2.16 kg load is 1 to 50 g / 10 min,
(Y2) The density is 880 to 920 kg / m ³ .   The base material layer (A) is a polyamide resin, a polyester resin, a polyolefin resin, a polyvinylidene chloride resin, a saponified ethylene-vinyl acetate copolymer, a polycarbonate resin, a polystyrene resin or a stretched product thereof, metal foil, inorganic oxide The laminate according to claim 2, comprising at least one selected from a vapor-deposited film, paper, and a non-woven fabric as a substrate.   The base material layer (A) contains at least a portion thereof at least one adhesive selected from a polyurethane, an isocyanate compound, a mixture of polyester or a polyol and an isocyanate compound, and a reaction product on the base material The laminated body of Claim 2 or 3 characterized by doing.   A liquid packaging bag using the laminate according to any one of claims 1 to 4 as a packaging material.