JP4859442B2 - Laminated film and packaging material comprising laminated film - Google Patents

Description

The present invention relates to a laminated film comprising an intermediate layer of a pressure-sensitive adhesive composition having an appropriate adhesiveness suitable as a packaging material that has easy opening and can be resealed. In the packaging material which can be sealed, the heat seal layer has a specific composition, whereby the heat sealability and easy-openability are improved, and the laminated film and the packaging material.

Packaging for snacks such as rice crackers and potato chips, food packaging such as jelly, milk, yogurt, pudding, tofu and lactic acid beverages, blister packaging, and other packaging materials for pharmaceuticals, medical devices, daily necessities, miscellaneous goods, etc. A package in which a cup or tray-like plastic container is sealed with a lid made of a plastic laminate film or an aluminum foil laminate film is widely used. The physical properties required for such a packaging material are mechanical strength that can withstand distribution channels, sealing strength that can maintain hygiene, and good openability during use.

However, such conventional packaging materials are excellent in easy-openability, but most of them cannot be resealed (resealed) at all once they are opened to take out the contents.
On the other hand, as a re-sealable packaging material, a lid formed by joining a front base material and a back base material through an adhesive layer is used, and the adhesive layer is exposed at the time of opening so that it can be opened and closed freely. Container (for example,
Patent Document 1) Adhesive agent (such as styrene / butadiene copolymer, ethylene / vinyl acetate copolymer) and terpene resins, petroleum hydrocarbon resins, etc.
Resealable packaging material using a sticky adhesive consisting of a blend with a tackifier)
For example, Patent Document 2 and Patent Document 3), or a multilayer film (for example, Patent Documents 4 and 5) using a pressure-sensitive adhesive using a hydrogenated styrene-butadiene copolymer as an elastomer, such as a pressure-sensitive adhesive layer as an intermediate layer Various methods using the method have been proposed.

Japanese Utility Model Publication No.62-31422 Japanese National Patent Publication No. 4-502588 Japanese Patent Laid-Open No. 2002-301786 JP 2003-175567 A JP 2004-58568 A

However, even if a laminated film having an intermediate layer of a pressure-sensitive adhesive composition composed of a tackifier such as terpene resins and an elastomer such as styrene / butadiene copolymer described in such a patent document is used as an easily openable packaging material, Either the surface resin layer and the adhesive resin layer, or the heat seal resin layer and the adhesive resin layer are peeled off at the time of opening, or the adhesive strength of the adhesive resin layer is still insufficient. It has been found that there is a case where the balance between easy-openability and reseal strength is lacking because the unsealing strength is too strong or the reseal strength is insufficient.

Therefore, the object of the present invention is to enable heat sealing, easy opening and repeated resealing, and
The object is to obtain a packaging material that has excellent reseal strength and has a balance between easy-openability and resealability, and in particular, to further improve the low-temperature heat sealability and easy-openability of the heat seal layer.

The present invention provides an olefin block copolymer elastomer (A), an ethylene / vinyl acetate copolymer (B) having a vinyl acetate content of 25 to 80% by weight on one side of a laminate layer made of a thermoplastic resin (D). And a component selected from a propylene random copolymer (E1), an ethylene resin and a thermoplastic elastomer through an intermediate layer comprising a pressure-sensitive adhesive composition comprising a tackifier (C) ( A laminated film comprising a heat seal layer made of a thermoplastic polymer (E) made of E2), a container lid made of the laminated film, a package using the laminated film, and a container lid made of the laminated film The container which uses is provided.

The pressure-sensitive adhesive composition used in the present invention has an easy opening property and has an excellent characteristic that it has appropriate pressure-sensitive adhesive properties suitable as a packaging material that can be resealed.
In addition, when opening a package sealed by heat sealing (heat fusion), it has an appropriate heat seal strength (peeling strength), so that it is easy to open and the heat seal layer Fracture, the heat seal layer and the pressure-sensitive adhesive composition layer are delaminated between the layers, or the pressure-sensitive adhesive composition layer is cohesive failure or the pressure-sensitive adhesive composition layer is also broken, and the layer between the pressure-sensitive adhesive composition layer and the laminate layer By peeling off at the interface, the pressure-sensitive adhesive composition layer of the intermediate layer is exposed on the opening surface, and since the pressure-sensitive adhesive composition layer is excellent in self-adhesiveness, it has sufficient adhesive force just by pressing with a fingertip, Peeling
The adhesive layer has a feature that the self-adhesiveness of the pressure-sensitive adhesive layer does not decrease even when the adhesion is repeated.
In addition, the laminated film of the present invention is a type or composition ratio of a polymer used in the pressure-sensitive adhesive composition,
By appropriately selecting the thermoplastic resin used for the laminate layer and the thermoplastic resin used for the heat seal layer, when the heat seal part of the laminated film used for the package is peeled off, the heat seal layer breaks and the intermediate layer The pressure-sensitive adhesive composition cohesively breaks off, and the peeled portion becomes cloudy. Even when resealed, the resealed portion maintains a cloudy state. It is possible to discriminate whether it is a packaged body by visual inspection.
And the heat seal layer used for this invention is a propylene random copolymer (E1).
) And a thermoplastic polymer (E) comprising a component (E2) selected from an ethylene-based resin and a thermoplastic elastomer, whereby the low-temperature heat sealability and easy-openability can be further improved.

Hereinafter, the requirements constituting the present invention will be described.
[Olefin block copolymer elastomer (A)]
The olefin block copolymer elastomer (A) according to the present invention is a block copolymer having a so-called amorphous soft segment comprising at least one olefin elastomer polymer portion and at least one so-called hard segment in the molecule. It is a coalescence. The soft segment composed of the olefin elastomer polymer part is usually ethylene, propylene, 1
-Random polymer part of α-olefin such as butene, polymer part of diene compound (diolefin) such as butadiene and isoprene or its hydrogenated product, and hard segment is usually glass transition of polystyrene polymer part Polymer part with point above room temperature, ethylene,
Those having crystallinity in the α-olefin polymer part such as propylene and 1-butene, or those having crystallinity in the hydrogenated product of the butadiene polymer part.
As a preferable example of the olefin block copolymer elastomer (A),
Styrene / diene block copolymer (A1) having a soft segment comprising at least one diene block (diene polymer part; diolefin polymer part) and a hard segment comprising at least one styrene block (styrene polymer part) And a soft segment composed of at least one amorphous olefin block (amorphous olefin polymer part) and a hard segment composed of at least one crystalline olefin block (crystalline olefin polymer part) An olefin block copolymer (A2) can be exemplified, and these block copolymers are generally produced and sold as thermoplastic elastomers.

[Styrene-diene block copolymer (A1)]
The styrene / diene block copolymer (A1) according to the present invention is a block copolymer having a soft segment composed of a diene block (diene polymer portion) and a hard segment composed of a styrene block (styrene polymer portion). A kind of block copolymer produced and sold as a so-called thermoplastic elastomer, specifically, for example, styrene-butadiene block copolymer (SB), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene block copolymer (SI) and styrene-isoprene-styrene block copolymer (SIS) or hydrogenated products of these block copolymers. This hydrogenated product is a block copolymer in which all of the styrene block and diene block are hydrogenated, or a block copolymer in which only the diene block is hydrogenated, or a part of the styrene block and diene block is hydrogenated. It may be a partially hydrogenated product such as a block copolymer.
When using these block copolymers or hydrogenated products thereof as an adhesive composition,
You may use individually or in combination of 2 or more types.
Among these block copolymers, hydrogenated styrene-butadiene block copolymer (SB), hydrogenated styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer ( More preferred is a hydrogenated product of a block copolymer containing a styrene block and a diene block, such as a hydrogenated product of SIS) or a hydrogenated product of styrene-isoprene block copolymer (SI). -Styrene-ethylene-butene block copolymer (SEB), hydrogenated product of butadiene block copolymer (SB), styrene-butadiene-styrene block copolymer (SB)
S) Hydrogenated Styrene-Ethylene-Butene-Styrene Block Copolymer (SE
BS), a styrene-ethylene / propylene-styrene block copolymer (SEPS), which is a hydrogenated product of styrene-isoprene-styrene block copolymer (SIS), has excellent thermal stability during extrusion and stability during processing. In terms of suppressing the generation of odors, degradation products and odors,
Most preferred.
In the styrene / diene block copolymer (A1) according to the present invention, an adhesive composition formed by mixing an ethylene / vinyl acetate copolymer (B) and a tackifier (C) described later has a film forming ability. As long as MFR (melt flow rate; ASTM D-1238 load 5 kg, temperature 200 ° C.) is not particularly limited, it is usually 0.5 to 20 g / 10 minutes, preferably 1 to 1.
It is in the range of 5 g / 10 minutes.

[Olefin / Amorphous Olefin Block Copolymer (A2)]
The olefin / amorphous olefin block copolymer (A2) according to the present invention comprises a soft segment composed of at least one amorphous olefin block (amorphous olefin polymer portion) in the molecule and a crystalline olefin block (crystal Block copolymer having a hard segment composed of a functional olefin polymer part), and is produced as a so-called thermoplastic elastomer.
It is a kind of block copolymer sold.
The structure of the olefin / amorphous olefin block copolymer (A2) is not particularly limited as long as it has at least one amorphous olefin block A and crystalline olefin block B in the molecule, and (B-A) n ₁ , (BA) n ₂ -B, (AB) n ₃ -A (n ₁ ,
n ₂ and n ₃ are integers of 1 or more) and a structure in which these are bound by a coupling agent.
Among these, a triblock copolymer or a copolymer having a larger number of blocks is preferable.
As such a block copolymer (A2), specifically, a polymer block mainly composed of a diene compound or a hydrogenation treatment of these polymer blocks to form an ethylene / butene copolymer or an ethylene / propylene copolymer. Examples thereof include a block copolymer having a soft segment composed of an amorphous olefin block having a similar structure and a hard segment composed mainly of a diene compound and capable of becoming a crystalline polyolefin by hydrogenation treatment. Further, a block copolymer in which a part of a polymer part mainly composed of a diene compound and capable of becoming a crystalline polyolefin by hydrogenation treatment is replaced with a hard segment composed of a polymer part of a vinyl aromatic compound such as styrene can be exemplified. Specific examples of the diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3
-Pentadiene and 2-methyl-1,3-pentadiene are exemplified.
A soft segment comprising an amorphous olefin block having a structure similar to that of an ethylene / butene copolymer or an ethylene / propylene copolymer obtained by hydrogenating a polymer block mainly composed of a diene compound is, for example, vinyl polybutadiene. Bonds (1,2- and 3,4-
By hydrogenating a polymer block having a bond content of about 25-85%,
An amorphous olefin block having a structure similar to that of an amorphous ethylene / butene copolymer is obtained.
The polymer part that is mainly composed of a diene compound and can be converted into a crystalline polyolefin by hydrogenation treatment, for example, vinyl bonds (contents of 1,2- and 3,4-bonds) of polybutadiene,
By hydrogenating a polymer block of 25% or less, a crystalline olefin block having a structure similar to an ethylene polymer can be obtained.
As such a block copolymer (A2), specifically, crystalline olefin (crystalline ethylene polymer part) -ethylene butene (amorphous olefin polymer part) -crystalline olefin (crystalline ethylene polymer) Part) block copolymer (CEBC), styrene-ethylene butene (amorphous olefin polymer part) -crystalline olefin (crystalline ethylene polymer part) block copolymer (SEBC), JSR Corporation Product name: DYNARON, DR6100P, DR6200P (CEBC), DR4600P, DR4630P (S
Various brands of EBC) are commercially available.
Other examples of the block copolymer (A2) include a propylene homopolymer or a crystalline propylene polymer mainly composed of propylene and a small amount of propylene and other α-olefin such as 1-butene. A crystalline olefin polymer part is obtained by living polymerization, and then an amorphous olefin polymer part is obtained by copolymerizing propylene and other α-olefins such as ethylene and 1-butene. Examples include α-olefin-propylene block copolymers.

[Ethylene / vinyl acetate copolymer (B)]
The ethylene / vinyl acetate copolymer (B) according to the present invention is a copolymer with ethylene having a vinyl acetate content in the range of 35 to 70 % by weight. An ethylene / vinyl acetate copolymer having a vinyl acetate content of less than 25% by weight is mixed with the olefin block copolymer elastomer (A) and a tackifier (C) described later to form a laminated film as an adhesive composition. Even if it is used for the intermediate layer, good reseal strength may not be obtained. On the other hand, the ethylene / vinyl acetate copolymer exceeding 80% by weight is the olefin block copolymer elastomer (A) and the adhesive described later. Even if mixed with the imparting agent (C) and used as an adhesive composition in the intermediate layer of the laminated film, there is a possibility that good reseal strength cannot be obtained.
The ethylene / vinyl acetate copolymer (B) according to the present invention is mixed with the olefin-based block copolymer elastomer (A) and a tackifier (C) described later and has a film-forming ability as an adhesive composition. As long as the MFR (melt flow rate; ASTM D-1238 load 2160 g, temperature 190 ° C.) is not particularly limited, it is usually in the range of 0.5 to 20 g / 10 minutes, preferably 1 to 15 g / 10 minutes. From these, it is sufficient to select appropriately in consideration of extrusion lamination and coextrusion moldability.

[Tackifier (C)]
The tackifier (C) according to the present invention is a resinous substance that is generally produced and sold as a tackifier, specifically, coumarone resins such as coumarone and indene resins; phenol-formaldehyde resins and xylene-formaldehyde Phenolic resins such as resins;
Terpene resins such as phenol resin, terpene resin (α, β-pinene resin), aromatic modified terpene resin, hydrogenated terpene resin; synthetic polyterpene resin, aromatic hydrocarbon resin, aliphatic hydrocarbon resin, aliphatic Cyclic hydrocarbon resin, aliphatic / alicyclic petroleum resin, aliphatic
Petroleum hydrocarbon resins such as aromatic petroleum resins, unsaturated hydrocarbon polymers, hydrogenated hydrocarbon resins, and hydrocarbon tackifying resins; rosin pentaerythritol ester, rosin glycerin ester, hydrogenated rosin, Examples thereof include rosin derivatives such as hydrogenated rosin ester, special rosin ester, and rosin tackifier.
Among these, a hydrogenated hydrocarbon resin, a hydrogenated aliphatic cyclic hydrocarbon resin, a hydrogenated aliphatic / alicyclic petroleum resin having a softening point in the range of 70 ° C. or higher, preferably 70 to 130 ° C., Hydrogenated resins such as hydrogenated terpene resin, hydrogenated synthetic polyterpene resin, rosin pentaerythritol ester, rosin glycerin ester, hydrogenated rosin ester are olefin block copolymer elastomer (A) and ethylene / acetic acid This is preferred because of good compatibility with the vinyl copolymer (B). When the softening point is less than 70 ° C., the tack force is good, but the adhesive force and cohesive force are small, and when the softening point exceeds 130 ° C., the adhesive force and cohesive force are good, but the tack force is small. There is a risk of becoming.

[Adhesive composition]
The pressure-sensitive adhesive composition of the present invention is a composition comprising the olefin block copolymer elastomer (A), the ethylene / vinyl acetate copolymer (B), and the tackifier (C), preferably Is 10 to 80% by weight of the olefin block copolymer elastomer (A)
, More preferably in the range of 20 to 70% by weight, ethylene / vinyl acetate copolymer (B) 10 to
80% by weight, more preferably 20 to 70% by weight and tackifier (C) 10 to 40% by weight, more preferably 10 to 30% by weight [provided that (A) + (B) + (C ) = 100
Weight%. 〕It is in.
As the pressure-sensitive adhesive composition, olefin block copolymer elastomer (A), ethylene
The pressure-sensitive adhesive composition lacking any of the vinyl acetate copolymer (B) and the tackifier (C) includes a thermoplastic resin (D), a propylene random copolymer (E1), an ethylene resin, and When a laminated film is used as an intermediate layer with a thermoplastic polymer (E) composed of a component (E2) selected from thermoplastic elastomers, the heat seal strength (initial opening strength) is too strong or the reseal strength is too high. It may be insufficient, and the balance between easy-openability and reseal strength may be lacking.
The pressure-sensitive adhesive composition of the present invention heats more by making the composition amounts of the olefin block copolymer elastomer (A), the ethylene / vinyl acetate copolymer (B) and the tackifier (C) within the above ranges. A laminated film having an easy-opening property and resealability excellent in the balance between the sealing strength (initial opening strength) and the resealing strength is obtained.
Either a pressure-sensitive adhesive composition of the present invention or an olefinic block copolymer elastomer (A) or an ethylene / vinyl acetate copolymer (B) that is a component of the pressure-sensitive adhesive composition, or both, a heat-resistant stabilizer, Various additives used in ordinary thermoplastic resins such as weathering stabilizers, UV absorbers, lubricants, slip agents, nucleating agents, anti-blocking agents, antistatic agents, antifogging agents, pigments, dyes, inorganic or organic fillers, etc. May be added within a range not impairing the object of the present invention.

[Thermoplastic resin (D)]
The thermoplastic resin (D) according to the present invention is various known thermoplastic resins, specifically, for example,
Polyolefin (polyethylene, polypropylene, polybutene, poly-4-methyl / 1-pentene, modified polyolefin graft-modified with unsaturated carboxylic acid or derivatives thereof), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, glycol modified polyethylene) Terephthalate, glycol-modified polybutylene terephthalate, etc.), polyamide (nylon-6, nylon-66, nylon-MXD6, etc.), polyvinyl chloride, polyimide, ethylene / vinyl alcohol copolymer,
Polyvinyl alcohol, polyacrylonitrile, polystyrene, acrylonitrile / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, polycarbonate,
Ethylene / vinyl acetate copolymer (EVA), ethylene / (meth) acrylic acid copolymer or its ionomer, ethylene / (meth) acrylic acid ester copolymer, etc.
An acid (derivative) copolymer or a mixture thereof can be exemplified.
Polyolefins include ethylene high polymers such as high pressure low density polyethylene (HP-LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE) and high density polyethylene (HDPE) or ethylene and other α -Ethylene-based ethylene polymers (polyethylene) such as random copolymers with olefins; polypropylene (PP), propylene / ethylene random copolymers, propylene / ethylene / 1-butene random copolymers, propylene / ethylene copolymers A propylene-based polymer (polypropylene) mainly composed of propylene, such as a homopolymer of propylene such as 1-butene random copolymer, propylene / ethylene block copolymer, or a copolymer of propylene and another α-olefin; Poly 1-butene, 1-butene pro 1-butene mainly composed of 1-butene such as a pyrene random copolymer, a 1-butene homopolymer such as 1-butene / ethylene random copolymer, or a copolymer of 1-butene and another α-olefin. 4-butene polymer (polybutene); poly-4-methyl / 1-pentene, 4-methyl / 1-pentene / α-olefin random copolymer, etc.
4-methyl / 1-pentene heavy polymer mainly composed of 4-methyl / 1-pentene, such as a homopolymer of methyl / 1-pentene or a copolymer of 4-methyl / 1-pentene and other α-olefin Examples thereof include polyunion (poly-4-methyl / 1-pentene).
Such polyolefin may be partly or wholly graft-modified with an unsaturated carboxylic acid such as maleic acid or maleic anhydride or a derivative thereof. Further, although depending on the combination of a propylene random copolymer (E1) described later and a thermoplastic polymer (E) composed of a component (E2) selected from ethylene resins and thermoplastic elastomers, Among plastic resins (D), ethylene polymers such as MDPE and HDPE, propylene polymers, 4-methyl
A 1-pentene polymer, polyester, polyamide, polystyrene and the like are preferable.
The thermoplastic resin (D) according to the present invention includes a heat resistance stabilizer, a weather resistance stabilizer, an ultraviolet absorber, a lubricant, a slip agent, a nucleating agent, an anti-blocking agent, an antistatic agent, an antifogging agent, a pigment, a dye, Various additives used in ordinary thermoplastic resins such as inorganic or organic fillers may be added within a range not impairing the object of the present invention.

[Thermoplastic polymer (E)]
The thermoplastic polymer (E) according to the present invention is composed of a propylene random copolymer (E1) and a component (E2) selected from an ethylene resin and a thermoplastic elastomer. Thereby, low-temperature heat-sealability and easy-openability can be improved.
Examples of the propylene random copolymer (E1) include a propylene / ethylene random copolymer, a propylene / ethylene / 1-butene random copolymer, and a propylene / 1-butene having a melting point (Tm) in the range of 110 to 150 ° C. Propylene such as random copolymers and other α-
Random copolymer with olefin; 1-butene such as 1-butene / propylene random copolymer, 1-butene / ethylene random copolymer having a melting point (Tm) in the range of 75 to 125 ° C., and other α- Examples are random copolymers with olefins.
The ethylene-based resin is a polymer mainly composed of ethylene and has a melting point (Tm) of 90 to 130.
Very low density polyethylene (VLDPE) and high pressure low density polyethylene (HP
-LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE)
), Ethylene homopolymers such as high density polyethylene (HDPE) or ethylene and other α
-Random copolymer with olefin, ethylene / vinyl acetate copolymer (EVA), ethylene / ethyl acrylate copolymer (EEA), ethylene / (meth) acrylic acid copolymer (
There are copolymers of ethylene and monomers having polar groups, such as EMAA).
Examples of the thermoplastic elastomer include low crystalline or amorphous ethylene / α-olefin random copolymer, propylene / α-olefin random copolymer, and the like.
The component (E2) selected from the ethylene resin and the thermoplastic elastomer is one type or two or more types of components selected from the ethylene resin and the thermoplastic elastomer.
The composition ratio of the propylene random copolymer (E1) and the component (E2) selected from an ethylene resin and a thermoplastic elastomer is usually 55 to 95 for the random copolymer (E1).
% By weight, component (E2) of 45 to 5% by weight, preferably a propylene random copolymer (E
1) is 70 to 95% by weight, and component (E2) is 30 to 5% by weight.
If the propylene random copolymer (E1) is less than 55% by weight, a stringing phenomenon may be observed. On the other hand, if it exceeds 95% by weight, the effects of low temperature heat sealability and easy openability may be insufficient.
In addition, resins and elastomers other than those used for the random copolymer (E1) and the component (E2) may be blended with the thermoplastic polymer (E) as necessary as long as it does not contradict its purpose. . Examples thereof include polybutene, poly-4-methyl / 1-pentene, modified polyolefin graft-modified with unsaturated carboxylic acid or derivatives thereof, polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, glycol modification). Polyethylene terephthalate, glycol-modified polybutylene terephthalate, etc.), polyamide (nylon-6, nylon-66, nylon-MXD6, etc.),
Polyvinyl chloride, polyimide, ethylene / vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polystyrene, acrylonitrile / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, polycarbonate, ethylene / vinyl acetate copolymer (EVA) , Ethylene / (meth) acrylic acid copolymers or ionomers thereof, ethylene / acid (derivative) copolymers such as ethylene / (meth) acrylic acid ester copolymers, or mixtures thereof.
Furthermore, the thermoplastic polymer (E) according to the present invention includes a heat resistance stabilizer, a weather resistance stabilizer, an ultraviolet absorber, a lubricant, a slip agent, a nucleating agent, an anti-blocking agent,
Various additives usually used for thermoplastic resins such as antistatic agents, antifogging agents, pigments, dyes, inorganic or organic fillers, etc. may be added within the range not impairing the object of the present invention.

[Laminated film]
In the laminated film of the present invention, the propylene random copolymer (E1), the ethylene resin, and the heat are provided on one side of the laminate layer made of the thermoplastic resin (D) via the intermediate layer made of the pressure-sensitive adhesive composition. It is a laminated film formed by laminating a heat seal layer (heat fusion layer) made of a thermoplastic polymer (E) made of a component (E2) selected from plastic elastomers. Each of the laminate layer and the heat seal layer may be a single layer or a multilayer of two or more layers. The laminated film of the present invention is not limited to a film shape, and may be a tape shape.
The thickness of the laminated film of the present invention can be determined depending on various applications, but the thickness of the laminate layer is usually 1 to 100 μm, more preferably 5 to 60 μm, and the thickness of the intermediate layer made of the pressure-sensitive adhesive composition is 1 to 498 μm. , More preferably 1 to 94 μm, the thickness of the heat seal layer is 1 to 20 μm,
More preferably, it exists in the range of 1-10 micrometers.
In order to improve the printability or adhesion to other films, slipperiness, etc., the laminated film of the present invention can be treated with, for example, corona treatment, flame treatment, plasma treatment, undercoat treatment, etc. An activation process may be performed.
Further, depending on the use, a base material layer described later can be bonded to the laminate layer of the laminated film of the present invention and used for various purposes.

[Base material layer]
The base material layer according to the present invention is a sheet-like or film-like material made of a thermoplastic resin, paper,
Made of aluminum foil or the like. As the thermoplastic resin, the same as the thermoplastic resin (D),
Various known thermoplastic resins, specifically, for example, polyolefin (polyethylene, polypropylene, polybutene, poly-4-methyl / 1-pentene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide ( Nylon-6, nylon-66, nylon-MXD6, etc.), polyvinyl chloride, polyimide, ethylene / vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polycarbonate, polystyrene, ethylene / vinyl acetate copolymer (EVA)
Examples include ethylene / (meth) acrylic acid copolymers or their ionomers, ethylene / (meth) acrylic acid ester copolymers, ethylene / acid (derivative) copolymers such as ionomers, or mixtures thereof. it can.
Of these, thermoplastic resins having good stretchability and transparency, such as polypropylene, polyethylene terephthalate, and polyamide, are preferable. In addition, the base material layer made of such a thermoplastic resin film may be an unstretched film or a stretched film.
It may be a laminate such as a co-extruded product of more than seeds, an extruded laminate product, a dry laminate product or the like.
Among these base material layers, a biaxially stretched film made of polypropylene, polyethylene terephthalate, polyamide or the like is preferable because it is excellent in transparency and rigidity.
In order to impart gas barrier properties to these base material layers, a metal such as aluminum or zinc or an inorganic oxide such as aluminum oxide, zinc oxide, or silicon oxide (silica) may be deposited.
In order to improve the adhesiveness between one side or both sides of the base material layer and the laminate layer of the laminated film of the present invention, for example, corona treatment, flame treatment, plasma treatment, undercoat treatment, primer coat treatment, flame treatment, etc. A surface activation treatment may be performed. The thickness of the base material layer is usually 5 to 1000 μm, preferably 9 to 100 μm.
As a specific configuration example of a laminate comprising the base material layer and the laminate film of the present invention, for example, biaxially stretched polyethylene terephthalate film (PET) / laminate film [laminate layer / adhesive comprising thermoplastic resin (D) Intermediate layer / thermoplastic polymer (E) comprising the agent composition
Heat seal layer], PET / PET / laminated film, PET / aluminum foil /
Laminated film, PET / deposited PET / laminate film, transparent deposited PET / laminate film, biaxially stretched polyamide film (ONY) / laminate film, ONY / ethylene-vinyl alcohol copolymer film / laminate film, transparent vapor deposited PET / ONY / A laminated film can be mentioned. When the base material layer and the laminated film are bonded to each other in such a laminate, as described above, for example, a method of dry laminating using a urethane-based dry laminating adhesive, a high-pressure polyethylene or the like is used as the base material layer and the laminated film. Various known methods such as an extrusion laminating method of extruding and laminating between the two can be adopted. Moreover, the printing layer may be provided between the base material layer and the laminated film.

[Production method of laminated film]
The laminated film of the present invention can be produced by various known methods.
For example, a film to be a laminate layer made of a thermoplastic resin (D) and a film to be a heat seal layer made of a thermoplastic resin (E) are separately obtained in advance, and then the adhesive composition is melt-extruded and laminated. A so-called sand lamination method in which a film to be a layer and a film to be a heat seal layer are laminated and laminated; a film to be a laminate layer previously made of a thermoplastic resin (D) or a propylene random copolymer (E1) and ethylene After obtaining the film used as the heat seal layer which consists of a thermoplastic polymer (E) which consists of a component (E2) chosen from an epoxy resin and a thermoplastic elastomer, a propylene random copolymer (E1) and ethylene on the film A thermoplastic polymer (E) comprising a component (E2) selected from a thermoplastic resin and a thermoplastic elastomer; A so-called co-extrusion laminating method in which an adhesive composition or a thermoplastic resin (D) and a pressure-sensitive adhesive composition are co-extruded and the pressure-sensitive adhesive composition layer and the film are laminated together; A film to be a laminate layer comprising (D), a heat seal layer comprising a thermoplastic polymer (E) comprising a propylene random copolymer (E1) and a component (E2) selected from an ethylene resin and a thermoplastic elastomer; And a laminate layer made of a thermoplastic resin (D) with a film made of the pressure-sensitive adhesive composition as an intermediate layer and with or without an adhesive. There is a so-called dry laminating method in which a film to be used and a film to be a heat seal layer made of a thermoplastic polymer (E) are laminated together and laminated. Is a thermoplastic polymer (E) composed of a thermoplastic resin (D), a propylene random copolymer (E1) and a component (E2) selected from an ethylene resin and a thermoplastic elastomer, and an adhesive composition. Using the above multilayer die, it can be produced by a so-called coextrusion molding method in which the pressure-sensitive adhesive composition is coextruded so as to be an intermediate layer.
Among these production methods, the coextrusion molding method is most preferable because the thickness of each layer can be controlled uniformly and accurately.
The coextrusion molding may be either a casting method using a flat die such as a T-die or an inflation method using a circular die.

[Container lid]
The container lid material of this invention consists of the said laminated | multilayer film. When the laminated film of the present invention is used as a container lid, only the laminated film may be used as a lid, or the base material layer is bonded to the laminated layer of the laminated film to form a heat seal layer of the laminated film. You may use as an inner surface (fusion layer).
As a specific configuration of such a container lid member, a laminate comprising the substrate layer and the laminated film of the present invention can be used.
Various known containers can be used as the container to which the container lid material of the present invention is applied as long as it is a heat-sealable container. Specifically, for example, a sheet made of a thermoplastic resin such as a propylene polymer, an ethylene polymer, a styrene polymer, polyester, polyamide or the like, a tray, a cup, a bottle, or the like, or an ethylene heavy Examples include those having the above-mentioned shape made of paper in which a coalescence is laminated on the inner surface. The container made of thermoplastic resin may be a single layer or a laminate composed of two or more kinds of thermoplastic resins.
As such a container, a container made of a propylene polymer has a good balance between heat resistance and appropriate flexibility, and is excellent in combination with the container lid material of the present invention.

[Packaging]
The package of the present invention is a package comprising at least one of the laminated films. In such a package, at least one is a laminated film, and if necessary, a packaging material (in a three-sided seal bag formed of two laminated films in which a base material layer is bonded to the laminated layer surface of the laminated film)
After filling the contents), fill the packaging material into a four-sided sealed package with the mouth heat-sealed, or a two-side sealed bag with the side film folded and sealed, and then heat-seal the mouth The three-way seal packaging body formed can be mentioned.
The packaging body of the present invention is not limited to the above-mentioned form, and after the packaging material is filled in a container such as a film, sheet, tray, cup, bottle or the like provided with a heat sealable layer, the laminated film And a package body formed by sealing the upper surface (mouth) with a container lid material (sealing material) made of
Moreover, the package of this invention may have a tape-shaped laminated film affixed to at least one of the part used as an opening part.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples without departing from the gist of the invention.

[Method for evaluating physical properties]
Various test methods and evaluation methods in the present invention are as follows.
(1) Heat seal strength;
Before measuring the heat seal strength, a laminated layer of a laminated film subjected to corona treatment and a polyethylene terephthalate biaxially stretched film having a thickness of 12 μm are made of a urethane-based adhesive (Mitsui Takeda Chemicals: trade name “Takelac A616” (50% ) + “Takelac A65” (3
. 13%) + ethyl acetate (46.87%)) and dry laminated to prepare a multilayer film.
The heat seal strength is measured using a heat sealer TP-701-B manufactured by Tester Sangyo Co., Ltd., with a heat seal layer of the laminated film and an unstretched polypropylene sheet having a thickness of 300 μm.
At each temperature, heat sealing was performed under conditions of a seal gauge pressure of 0.2 MPa, a time of 1 second, and a seal width of 5 mm. The heating was performed only on the upper side. Next, the heat-sealed test piece was cut into a width of 15 mm, and 500 m was measured using a Tensilon universal testing machine RTM-100 manufactured by Orientec Corporation.
Peeling was performed at a tensile speed of m / min, and the maximum strength was defined as heat seal strength. The measured value is an average value of 5 times. In addition to the heat seal strength, the peeled state of the heat seal opening was observed.
(2) Reseal strength;
The heat seal peeling surfaces of the test pieces for which the heat seal strength was measured were put together, and using a heat sealer TP-701-B manufactured by Tester Sangyo Co., Ltd., at a set temperature of 30 ° C., a seal gauge pressure of 1.
The heat seal peeled surfaces were resealed (resealed) under the conditions of 5 kg / m ² , time 1 second, and seal width 10 mm. The heating was performed from the upper and lower surfaces. Subsequently, the resealed test piece was peeled off at a tensile speed of 500 mm / min using a Tensilon universal testing machine RTM-100 manufactured by Orientec Co., and its maximum strength was defined as reseal strength. The measured value is the average value of the test pieces that could be resealed.
(3) Melting point (Tm);
In accordance with JIS K 7121, the heating rate was measured at 10 ° C. per minute using DSC.

[Each raw material]
The polymers used in Examples and Comparative Examples are as follows.
(1) Olefin-based block copolymer elastomer (A)
(1-1) Styrene / diene block copolymer (A1)
Hydrogenated product of styrene-butadiene-styrene block copolymer (SBS) (SEBS)
)
Product name: “Clayton G1657”, MFR: 8 g
/ 10 minutes.
(2) Ethylene / vinyl acetate copolymer (B)
Ethylene / vinyl acetate copolymer (40% EVA)
Made by Mitsui DuPont Polychemical, ethylene / vinyl acetate copolymer (40% EVA), vinyl acetate content: 40% by weight, density: 970 kg / m ³ , MFR: 2 g / 10 min.
(3) Tackifier (C)
Terpene resin, manufactured by Yasuhara Chemical Co., Ltd., trade name; “YS Resin PX1150N”, ring and ball method softening point; 11
5 ℃
(4) Thermoplastic resin (D) (laminate layer resin)
Polypropylene homopolymer (H-PP)
Product name: “Mitsui Polypro F107DV”, density: 910 kg / m ³ , melting point: 160 ° C., MFR: 7 g / 10 min.
(5) Thermoplastic polymer (E) (heat seal layer resin)
(I) Thermoplastic resin (E1) “Mitsui Polypro F329D” propylene / ethylene / 1-
Butene random copolymer (R-PP), manufactured by Mitsui Chemicals, density: 910 kg / m ³ , melting point: 13
9 ° C., MFR; 9 g / 10 min.
(Ii) Thermoplastic elastomer (E2)
(a) XM-7070 Toughmer XM propylene / butene copolymer, manufactured by Mitsui Chemicals, melting point (
Tm); 75 ° C., MFR; 7 g / 10 min (230 ° C.)
(b) XR110T Toughmer XR propylene / butene copolymer, manufactured by Mitsui Chemicals, melting point (T
m); 110 ° C. MFR; 7 g / 10 min (230 ° C.)
(c) Tuffmer A A-2085S ethylene / 1-butene random copolymer, manufactured by Mitsui Chemicals, density: 0.885 g / cm ³ , melting point (Tm): 64 ° C., MFR: 2 g / 10 min (1
90 ° C)
(d) 3300F Hi-Zex HDPE, manufactured by Mitsui Chemicals, density; 0.950 g / cm ³ ,
Melting point (Tm): 132 ° C., MFR: 1.1 g / 10 min (190 ° C.)
(e) 12P Mirason LDPE, made by Mitsui DuPont Polychemical, density: 0.927g
/ Cm ³ , melting point (Tm); 114 ° C., MFR; 3 g / 10 min (190 ° C.)

<Example 1>
H-PP is used as the resin for the laminate layer, and SEBS: 30% by weight, 40% EVA: 50% by weight and terpene resin; Using a pressure-sensitive adhesive composition in which 0.1 part by weight of an agent is uniformly mixed with a twin-screw extruder, a blend in which R-PP: 85% by weight, XM-7070: 15% by weight is mixed as a resin for the heat seal layer 3mm 3 layer unstretched film forming machine 40mmφ extruder x 3
Each was put into a table, extruded from a feed block type T die at 210 ° C. at an extrusion temperature of 180 to 230 ° C., quenched with a casting roll at 30 ° C., and then subjected to corona treatment to obtain a laminated film. .
The total thickness of the obtained laminated film was 50 μm, and the thickness of each layer was laminate layer / intermediate layer composed of pressure-sensitive adhesive composition / heat seal layer = 15/30/5 μm.
The evaluation results of the obtained laminated film are shown in Table 1.

<Example 2>
As a resin for the heat seal layer, R-PP; 75 wt%, XM-7070; 25 wt%
A laminated film was obtained in the same manner as in Example 1 except that a blended material was used.
The evaluation results of the obtained laminated film are shown in Table 1.

<Example 3>
A laminated film was obtained in the same manner as in Example 1 except that a blend obtained by mixing R-PP; 75 wt%, XR110T; 25 wt% was used as the resin for the heat seal layer.
The evaluation results of the obtained laminated film are shown in Table 1.

<Example 4>
As a resin for the heat seal layer, R-PP; 75% by weight, A-2085S; 25% by weight
A laminated film was obtained in the same manner as in Example 1 except that a blended material was used.
The evaluation results of the obtained laminated film are shown in Table 1.

<Example 5>
A laminated film was obtained in the same manner as in Example 1 except that a blend obtained by mixing R-PP; 75% by weight, 3300F; 25% by weight was used as the resin for the heat seal layer.
The evaluation results of the obtained laminated film are shown in Table 1.

<Example 6>
A laminated film was obtained in the same manner as in Example 1 except that a blend obtained by mixing R-PP; 75 wt%, 12P; 25 wt% was used as the resin for the heat seal layer.
The obtained laminated film evaluation results are shown in Table 1.

Generally, the heat-sealing strength of the easy-open film is 20 N / 15 mm or less, and the heat-sealing strength of the laminated film of the present invention is also a propylene random copolymer ( By using a heat seal layer comprising a thermoplastic polymer (E) comprising E1), an ethylene resin and a component (E2) selected from thermoplastic elastomers, it is possible to control within this range.

Since the pressure-sensitive adhesive composition of the present invention is excellent in self-adhesiveness and does not deteriorate even if it is repeatedly peeled and adhered, it can be resealed by using it as an intermediate layer of a film made of a thermoplastic resin. Excellent packaging material is obtained.
The laminated film of the present invention comprises a heat seal layer (heat fusion layer) comprising a thermoplastic polymer (E) comprising a propylene random copolymer (E1) and a component (E2) selected from an ethylene resin and a thermoplastic elastomer. ) After heat-sealing (heat-sealing) with each other or with a film or container provided with a heat-sealing layer that can be heat-sealed with the heat-sealing layer, the heat-sealing portion is peeled off (opened). Since the layer is broken and the pressure-sensitive adhesive composition layer excellent in self-adhesiveness of the intermediate layer is exposed on the release surface, preferably the pressure-sensitive adhesive composition layer is cohesively broken and exposed on both release surfaces. It has a feature that it can be resealed by pressing the peeling surface with a finger or the like, and also has the advantage that there is little decrease in the Lee-seal strength even after repeated opening and bonding.
The heat seal layer used in the present invention comprises a propylene random copolymer (E1) and a thermoplastic polymer (E) comprising a component (E2) selected from an ethylene resin and a thermoplastic elastomer. Sealability and easy-openability can be further improved.
Utilizing such characteristics, it is suitable as a packaging material, particularly as a lid material for sheets, trays, cups, bottles, etc. made of propylene-based polymers, packaging for snacks such as rice crackers, potato chips, etc., or jelly, milk It can be suitably used as a packaging material for food packaging such as yogurt, pudding, tofu and lactic acid beverages, packaging for pharmaceuticals and medical instruments, blister packaging, and other daily necessities and miscellaneous goods.

Claims (9)

An olefin block copolymer elastomer (A), an ethylene / vinyl acetate copolymer (B) having a vinyl acetate content of 35 to 70 % by weight, and a tackifier are provided on one side of a laminate layer made of a thermoplastic resin (D). From the propylene-based random copolymer (E1) and the component (E2) selected from an ethylene-based resin and a thermoplastic elastomer through an intermediate layer composed of a pressure-sensitive adhesive composition comprising (C) A laminated film comprising a heat seal layer made of a thermoplastic polymer (E) to be laminated. The pressure-sensitive adhesive composition is composed of 10 to 80% by weight of an olefin block copolymer elastomer (A) and 10 to 80% by weight of an ethylene / vinyl acetate copolymer (B) having a vinyl acetate content of 35 to 70 % by weight. And 10 to 40% by weight of the tackifier (C) [However, (A) + (B) + (C) = 100% by weight. The laminated film according to claim 1.   The laminated film according to claim 1, wherein the thermoplastic resin (D) is a propylene-based polymer.   After the heat seal layer made of the thermoplastic polymer (E) of the laminated film is heat sealed with another heat sealable thermoplastic resin layer, the heat seal layer breaks and adheres when the heat seal portion is peeled off. The laminated film according to any one of claims 1 to 3, wherein the intermediate layer made of the adhesive composition cohesively breaks and the adhesive composition is exposed on both surfaces of the heat seal peeling portion.   A container lid made of the laminated film according to claim 1.   The package formed by heat-sealing the heat-sealing layers of the laminated | multilayer film of any one of Claims 1-5.   The package body formed by heat-sealing the heat-seal layer of the laminated film of any one of Claims 1-6, and the other thermoplastic resin layer which can be heat-sealed.   A package formed by heat-sealing the upper surface of the container with the container lid material according to claim 5.   When the package is opened, the heat seal layer made of the thermoplastic polymer (E) of the laminated film breaks and the intermediate layer made of the pressure sensitive adhesive composition cohesively breaks. The package according to any one of claims 6 to 8, wherein the composition is exposed.