WO2024018903A1 - Multilayer film, cover material, and packaging material - Google Patents

Multilayer film, cover material, and packaging material Download PDF

Info

Publication number
WO2024018903A1
WO2024018903A1 PCT/JP2023/025058 JP2023025058W WO2024018903A1 WO 2024018903 A1 WO2024018903 A1 WO 2024018903A1 JP 2023025058 W JP2023025058 W JP 2023025058W WO 2024018903 A1 WO2024018903 A1 WO 2024018903A1
Authority
WO
WIPO (PCT)
Prior art keywords
multilayer film
layer
resin
mass
acid
Prior art date
Application number
PCT/JP2023/025058
Other languages
French (fr)
Japanese (ja)
Inventor
桂輔 浜崎
カタンユー クンタラウト
貴史 森谷
Original Assignee
Dic株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dic株式会社 filed Critical Dic株式会社
Priority to JP2023563852A priority Critical patent/JP7460036B1/en
Publication of WO2024018903A1 publication Critical patent/WO2024018903A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
    • B65D65/38—Packaging materials of special type or form
    • B65D65/40—Applications of laminates for particular packaging purposes

Definitions

  • the present invention relates to a multilayer film, a lid material, and a packaging material used for packaging materials such as foods and medical products.
  • containers have been used in which the openings of various resin containers for foods, medical products, etc. are sealed with a lid material using a multilayer film.
  • the lids of these containers are generally required to be easily opened so that the contents can be easily taken out, and to have suitable sealing properties so that the contents do not easily leak.
  • high temperature sterilization treatment is performed from the viewpoint of long-term preservation and hygiene of contents, and in addition to these sealing properties and easy opening, high heat resistance that can maintain seal strength even after high temperature treatment is required. It has been demanded.
  • the applicant As a film used for the lid material of such containers, the applicant has developed an easily peelable film that uses crystalline polyester (a1) and propylene block copolymer for the surface layer and crystalline polyester (a1) for the sealing layer. invented a film (see Patent Document 1).
  • This easily peelable film was a multilayer film that had suitable heat-sealability, easy-openability, and film processability, was resistant to blocking, and had high sealing strength.
  • the above-mentioned easily peelable film has a very high sealing strength against crystallized polyethylene terephthalate (C-PET), which is used as a highly heat-resistant container, and is difficult to peel and may leave film residue after peeling. there were.
  • C-PET crystallized polyethylene terephthalate
  • the transparency was somewhat low, and the visibility of the contents was sometimes poor.
  • the problem to be solved by the present invention is to achieve both excellent transparency and film processability, as well as good sealing strength and opening strength when used in crystallized polyethylene terephthalate (C-PET) containers, and to avoid film residue.
  • the first object of the present invention is to provide a multilayer film that has a good appearance after peeling.
  • the present invention provides a multilayer film having a sealing layer (D) and a surface layer (A), wherein the mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more, and the The mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more, and the mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more,
  • the above problem is solved by a multilayer film characterized in that the mass ratio of polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more.
  • the multilayer film of the present invention has suitable sealing properties and easy opening properties, it can be suitably applied as a lid material for sealing and sealing the openings of various resin containers.
  • the present invention is particularly suitable for use in foods, medical products, etc. that are subject to high-temperature sterilization.
  • the multilayer film of the present invention is a multilayer film having a sealing layer (D) and a surface layer (A), wherein the mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more.
  • the mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more
  • the mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more.
  • the multilayer film is characterized in that the mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more.
  • the sealing layer (D) of the multilayer film of the present invention preferably contains any two or more of crystalline polyester (d1), amorphous polyester (d2), and polyolefin resin (d3). (d1), an amorphous polyester (d2), and a polyolefin resin (d3) are more preferably contained.
  • the sealing layer (D) it is possible to realize a multilayer film that has anti-blocking properties, excellent unsealability, and a good peeling appearance without leaving any film residue.
  • the crystalline polyester (d1) is a polyester resin produced by polycondensing a polyhydric carboxylic acid and a polyhydric alcohol, and has crystallinity. Specifically, a part of the resin skeleton has a crystal structure such as a lamellar crystal type or a spherulite type derived from a regularly arranged structure. Such a crystalline polyester is characterized by having an endothermic peak derived from the heat of fusion of one or more crystals generated when the crystal structure is melted by heat in differential scanning calorimetry (DSC).
  • DSC differential scanning calorimetry
  • the melting point (Tm) of polyester resins such as crystalline polyester and amorphous polyester is a value determined by a method according to Japanese Industrial Standards (JIS K7121), that is, a differential scanning calorimetry (DSC) method, Specifically, it is a value measured using a differential scanning calorimeter under the following conditions.
  • Measuring device DSC-7020 manufactured by Hitachi High-Tech Corporation Sample: Put about 5 mg of sample into an aluminum container and cover with a lid. Measurement condition ; 1. Temperature increase from -50°C to 280°C (10°C/min) 2. Hold at 280°C for 5 minutes 3. Lower temperature from 280°C to 25°C (10°C/min) 4. Hold at 25°C for 5 minutes 5. Increase temperature from 25°C to 280°C (10°C/min) Analysis; In the measurement results of step 5, the temperature at which the endothermic peak is maximum is defined as the melting point (Tm).
  • polycarboxylic acids mentioned above include aromatic polycarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, and trimellitic acid, as well as succinic acid, adipic acid, and azelaic acid.
  • aromatic polycarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, and trimellitic acid, as well as succinic acid, adipic acid, and azelaic acid.
  • sebacic acid decanoic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, heptadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid.
  • Examples include polycarboxylic acids. These may be used alone or in combination of two or more.
  • the raw material components may include methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid.
  • heptadecanoic acid, octadecanoic acid, and other monocarboxylic acids may also be used.
  • polyhydric alcohol examples include ethylene glycol, diethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyltrimethylene glycol, 1,4-butanediol, 1,5-pentanediol, -Methylpentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,16 - hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol, pentaethylene glycol, and tri
  • the above polyhydric carboxylic acid and polyhydric alcohol may be used in any combination. Specifically, terephthalic acid/ethylene glycol copolymer, terephthalic acid/1,4-butanediol copolymer, terephthalic acid/1,4-butanediol/adipic acid copolymer, terephthalic acid/polytetramethylene ether glycol /1,4-butanediol copolymer, terephthalic acid/isophthalic acid/1,4-butanediol/polytetramethylene ether glycol copolymer, terephthalic acid/isophthalic acid/1,4-butanediol copolymer, etc. .
  • the melting point of the crystalline polyester (d1) is preferably 100 to 200°C, more preferably 110 to 180°C. By using a crystalline polyester having the above melting point, extrusion moldability becomes good. Further, the glass transition temperature of the crystalline polyester (d1) is preferably 40°C or lower, more preferably 0°C or lower, and even more preferably -20°C or lower. By using the crystalline polyester (d1) having the glass transition temperature, heat sealing properties and easy opening properties are improved. Examples of such crystalline polyester (d1) include resins commercially available under the trade name "Vylon" (Toyobo Co., Ltd.).
  • the glass transition temperature (Tg) of the polyester resin is a value determined by a method according to Japanese Industrial Standards (JIS K7121), that is, a differential scanning calorimetry (DSC) method.
  • the amorphous polyester (d2) is a polyester resin produced by polycondensing a polyhydric carboxylic acid and a polyhydric alcohol, and is a polyester that does not substantially exhibit crystallinity.
  • crystalline polyester (d1) is a polyester that does not have a clear melting peak temperature in the temperature range of 50°C to 280°C when measured using a differential scanning calorimeter as explained above. In the temperature range, it means that the heat of crystal fusion ( ⁇ H) is 1 J/g or less.
  • polyvalent carboxylic acids examples include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, maleic acid, and maleic anhydride.
  • Acid citraconic acid, dimethylmaleic acid, cyclopentene-1,2-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, fumaric acid, mesaconic acid, Itaconic acid, glutaconic acid, phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, 1,2,5-hexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, trimellitic acid, trimellitic anhydride , 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, pyromellitic anhydride and the like.
  • the raw material components may include methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid. , heptadecanoic acid, octadecanoic acid, and other monocarboxylic acids may also be used.
  • polyhydric alcohol examples include ethylene glycol, diethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyltrimethylene glycol, 1,4-butanediol, 1,5-pentanediol, -Methylpentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,16 - Hexadecanediol, 1,18-octadecanediol, 1,20-icosandiol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol, pentaethylene glycol, isosorbide,
  • the above polyhydric carboxylic acid and polyhydric alcohol may be used in any combination.
  • acid/ethylene glycol/1,4-cyclohexanedimethanol copolymer terephthalic acid/1,4-cyclohexanedimethanol/2,2,4,4-tetramethyl-1,3-cyclobutanediol copolymer, etc. It will be done.
  • the glass transition temperature of the amorphous polyester (d2) is preferably 45 to 130°C, more preferably 60 to 120°C.
  • amorphous polyester (d2) having the glass transition temperature suitable film processability and heat resistance can be ensured.
  • amorphous polyester (d2) include resins commercially available under the trade name "ECOZEN” (SK Chemical Co., Ltd.).
  • the total content of the crystalline polyester (d1) and amorphous polyester (d2) in the sealing layer (D) used in the present invention is 70% by mass or more, suitable heat sealability and heat resistance can be obtained. It is preferable in that it can be obtained. Further, from the viewpoint of obtaining a suitable film appearance, the content is more preferably 75% by mass or more, and more preferably 80% by mass or more. The upper limit of the content is not particularly limited, but is preferably 99% by mass or less, more preferably 95% by mass or less. Further, the content ratio of the crystalline polyester (d1) and the amorphous polyester (d2) is preferably 1:9 to 9:1.
  • the crystalline polyester (d1) and amorphous polyester (d2) in the seal layer (D) used in the present invention may be biodegradable polyesters.
  • biodegradable polyesters include polylactic acid resin, poly(butylene succinate) (PBS), poly(butylene succinate/adipate) copolymer (PBSA), poly(3-hydroxybutyric acid), and 3-hydroxy Polyhydroxyalkanoates such as copolymers of butyric acid and 3-hydroxyvaleric acid, copolymers of 3-hydroxybutyric acid and 4-hydroxybutyric acid, polyglycolic acid, polycaprolactone, ⁇ -propiolactone, and ⁇ -valero.
  • PBS poly(butylene succinate)
  • PBSA poly(butylene succinate/adipate) copolymer
  • 3-hydroxy Polyhydroxyalkanoates such as copolymers of butyric acid and 3-hydroxyvaleric acid, copolymers of 3-hydroxybutyric acid and 4-hydroxybutyric acid, polyglycoli
  • Aliphatic polyester compounds such as ring-opening polymers such as lactones, copolyesters of adipic acid, 1,4-butanediol, and terephthalic acid (polybutylene adipate terephthalate), polyesters made of succinic acid and ethylene glycol (polyethylene succinate)
  • biodegradable polyesters are also classified as crystalline polyesters by differential scanning calorimetry (DSC). It is a polyester that does not have a clear melting peak temperature in the temperature range of 50°C to 280°C when measured by a scanning calorimeter, and specifically, the heat of crystal fusion ( ⁇ H) is 1 J/g in this temperature range.
  • DSC differential scanning calorimetry
  • the seal layer (D) of the present invention contains a polyolefin resin (d3).
  • the polyolefin resin (d3) has the function of uniformly dispersing the crystalline polyester (d1) and the amorphous polyester (d2), which are difficult to miscible with each other, thereby improving blocking resistance and peeling appearance. The inventor assumes that this is the case.
  • As the polyolefin resin (d3) ethylene resin, propylene resin, etc. can be preferably used.
  • Ethylene resins include very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), linear medium density polyethylene (LMDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). ) and other polyethylene resins can be used.
  • propylene-based resins include propylene homopolymers, propylene- ⁇ -olefin random copolymers such as propylene-ethylene butene-1 copolymer, and propylene block copolymers such as propylene- ⁇ -olefin block copolymers. Examples include merging. Among these, propylene block copolymers are preferred.
  • a resin containing propylene and other ⁇ -olefins can be used.
  • the ⁇ -olefin include ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, etc.
  • ethylene is preferred because it has excellent heat resistance and impact resistance.
  • the propylene-ethylene block copolymer is not particularly limited, but can be obtained, for example, by polymerizing a polymer block mainly composed of propylene in the first step and polymerizing a copolymer block of ethylene and propylene in the second step. It will be done.
  • the propylene block copolymer preferably has a haze of 30% or more, preferably 40% when molded to a thickness of 60 ⁇ m using a cooling roll at 40° C. in the T-die film forming method. It is more preferable that it is above. By using a resin with such haze, suitable blocking resistance and film processability can be obtained.
  • the melt flow rate (MFR) of the above propylene block copolymer is 0.5 to 10 g/10 minutes (230°C, 21.18N) because it is easy to mold and easy to obtain suitable easy opening properties.
  • the amount is preferably 2 to 5 g/10 minutes, and more preferably 2 to 5 g/10 minutes.
  • the melting point of the propylene block copolymer is preferably 150°C or higher, more preferably 160°C or higher, because it is easy to mold and easy to ensure excellent heat resistance.
  • the seal layer (D) of the present invention contains the polyolefin resin (d3)
  • the content is 1 to 18% by mass of the resin component contained in the seal layer (D).
  • the content thereof should be 0.5 to 30% by mass in the resin component contained in the sealing layer (D). It is preferably 1 to 20% by weight, more preferably 1 to 18% by weight. This content is preferable in that it is possible to obtain suitable blocking resistance and film processability, and also to obtain transparency and no resin or film residue on the adherend after peeling, and to obtain a suitable peeled appearance. .
  • the resin used for the sealing layer (D) used in the present invention two or more of the above crystalline polyester (d1), the above amorphous polyester (d2), and polyolefin resin (d3) may be used. is preferred, and it is also preferred to use only these resins, but various resins used for packaging films other than these resins may also be used.
  • the other resins include thermoplastic elastomers such as polyethylene elastomers, polypropylene elastomers, and butene elastomers; ethylene-vinyl acetate copolymers (EVA), ethylene-methyl methacrylate copolymers (EMMA), and ethylene.
  • EAA Ethyl acrylate copolymer
  • EMA ethylene-methyl acrylate copolymer
  • E-EA-MAH ethylene-ethyl acrylate-maleic anhydride copolymer
  • EAA ethylene-acrylic acid copolymer
  • EAA ethylene-based copolymers
  • EAA ethylene-methacrylic acid copolymer
  • EAA ethylene-methacrylic acid copolymer
  • further examples include ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers.
  • the content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less in the resin component contained in the seal layer (D).
  • additives and the like may be appropriately used in the seal layer (D) used in the present invention.
  • additives for example, lubricants, antiblocking agents, ultraviolet absorbers, light stabilizers, antistatic agents, antifogging agents, colorants, etc. can be used as appropriate.
  • these additives are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the sealing layer (D).
  • the filler content is preferably 300 ppm or less, and preferably 200 ppm or less, since it is easy to ensure suitable heat sealability. It is more preferable that the amount is 100 ppm or less, and it is especially preferable that it is substantially not contained.
  • the thickness ratio of the sealing layer (D) to the total thickness of the multilayer film used in the present invention is as follows: , preferably in the range of 5 to 30%, more preferably in the range of 10 to 25%.
  • the surface layer (A) of the multilayer film of the present invention preferably contains any two or more of crystalline polyester (a1), amorphous polyester (a2), and polyolefin resin (a3); It is more preferable to contain (a1), amorphous polyester (a2) and polyolefin resin (a3).
  • crystalline polyester (a1) used in the surface layer (A) those similar to the crystalline polyester (d1) of the seal layer (D) can be used, and preferred ones are also the same.
  • the same amorphous polyester (d2) as in the seal layer (D) can be used, and preferred ones are also the same.
  • the same ones as the polyolefin resin (d3) in the seal layer (D) can be used, and preferred ones are also the same.
  • the content of the polyolefin resin (a3) in the resin component contained in the surface layer (A) used in the present invention is preferably 1 to 30% by mass, and 1 to 30% by mass, since film processability and transparency can be easily obtained. It is more preferably 25% by weight, and even more preferably 3-20% by weight.
  • the surface layer (A) used in the present invention two or more of the above crystalline polyester (a1), the above amorphous polyester (a2), and the above polyolefin resin (a3) are used as the resin. It is preferable to use these resins, and it is also preferable to use only these resins, but various resins used for packaging films other than these resins may also be used. As the other resin, the various resins exemplified in the seal layer (D) above can be similarly used. When using these other resins, the content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, and 5% by mass or less in the resin component contained in the surface layer (A). % or less is more preferable.
  • various additives similar to those in the seal layer (D) may be used in combination as appropriate.
  • these additives are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the surface layer (A).
  • the filler content is also preferably 300 ppm or less, more preferably 200 ppm or less, even more preferably 100 ppm or less, similar to the seal layer (D), and substantially It is particularly preferable not to contain it.
  • the thickness ratio of the surface layer (A) to the total thickness of the multilayer film is preferably in the range of 10 to 95%, more preferably in the range of 20 to 90%, since it is easy to obtain suitable film processability. preferable.
  • the intermediate layer (C) In the multilayer film of the present invention, it is also preferable to have an intermediate layer (C) directly laminated with the seal layer (D) between the surface layer (A) and the seal layer (D).
  • the intermediate layer contains a crystalline polyester (c1) and/or an amorphous polyester (c2), and the crystals in the resin component contained in the sealing layer (D)
  • the difference between the mass ratio of the amorphous polyester (d2) and the total mass ratio of the amorphous polyester (c2) in the resin component contained in the intermediate layer (C) is within 60 mass%.
  • the crystalline polyester (c1) and the amorphous polyester (c2) in the intermediate layer (C) is preferably adjusted.
  • crystalline polyester (c1) and the amorphous polyester (c2) those similar to the crystalline polyester (d1) and the amorphous polyester (d2) disclosed in the seal layer (D) can be used, and are preferable. The same goes for things.
  • the total content of the crystalline polyester (c1) and/or amorphous polyester (c2) in the resin component contained in the intermediate layer (C) is preferably 70 to 100% by mass, and 80 to 100% by mass. It is more preferable to express it in mass %.
  • the intermediate layer (C) may further contain a polyolefin resin (c3).
  • a polyolefin resin (c3) the same ones as those for the seal layer (D) can be used, and preferred ones are also the same.
  • the content of the polyolefin resin (c3) is preferably less than 30% by mass, more preferably less than 20% by mass, in the resin component contained in the intermediate layer (C).
  • the intermediate layer (C) it is preferable to use only the crystalline polyester (c1) and the amorphous polyester (c2) as resin components, but a polyolefin resin (c3) may also be used.
  • Various resins used for packaging films other than these resins may also be used.
  • the other resin the various resins exemplified in the seal layer (D) above can be similarly used.
  • the content thereof is preferably less than 20% by mass, more preferably less than 10% by mass, and 5% by mass in the resin component contained in the intermediate layer (C). More preferably, it is less than %.
  • additives similar to those in the seal layer (D) may be used in combination as appropriate.
  • these additives are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the intermediate layer (C).
  • the thickness ratio of the intermediate layer (C) to the total thickness of the multilayer film is preferably in the range of 5 to 80%, and preferably in the range of 10 to 70%. is more preferable.
  • the multilayer film of the present invention may include an intermediate layer (B) in addition to the surface layer (A), intermediate layer (C), and sealing layer (D).
  • the intermediate layer (B) is located between the surface layer (A) and the intermediate layer (C).
  • the intermediate layer (B) may be composed of two or more layers.
  • the intermediate layer (B) preferably contains crystalline polyester (b1) and/or amorphous polyester (b2) as a resin component. Further, the total mass ratio of the crystalline polyester (b1) and the amorphous polyester (b2) in the resin component contained in the intermediate layer (B) is preferably 80% by mass or more, and 90% by mass or more. It is more preferable that Furthermore, from the viewpoint of cost, it is preferable that the mass ratio of the crystalline polyester (b1) in the resin component contained in the intermediate layer (B) is smaller than that of the amorphous polyester (b2).
  • each layer contains crystalline polyester (b1) and amorphous polyester (b2), and the resin component contained in the intermediate layer (B) contains
  • the effects of the present invention can be suitably achieved by forming a layer in which the content of the crystalline polyester (b1) is 0 to 50% by mass and the content of the amorphous polyester (b2) is 50 to 100% by mass.
  • each layer may have the same composition or a different composition as long as it is the said composition range.
  • the thickness ratio of the intermediate layer (B) is preferably 20 to 90%, more preferably 40 to 70%.
  • the total thickness of the intermediate layer (B) is preferably 20 to 90% of the total thickness of the multilayer film, and more preferably 40 to 70%. preferable.
  • the multilayer film of the present invention is a film having the seal layer (D) and the surface layer (A). Further, the mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more, the mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more, and the The mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more.
  • crystalline polyester resin includes crystalline polyester (a1), crystalline polyester (b1), crystalline polyester (c1), crystalline polyester (d1), and other crystalline polyester resins, and includes amorphous polyester resins.
  • Polyester resin includes amorphous polyester (a2), amorphous polyester (b2), amorphous polyester (c2), amorphous polyester (d2) and other amorphous polyester resins
  • the polyolefin resin includes polyolefin resin (a3), polyolefin resin (b3), polyolefin resin (c3), polyolefin resin (d3), and other polyolefin resins.
  • the mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film of the present invention is 10% by mass or more, more preferably 20% by mass or more, and preferably 20 to 50% by mass or more.
  • the content is more preferably 20 to 40% by mass.
  • the mass ratio of the crystalline polyester resin to the entire multilayer film is 20% by mass or more, more preferably 50% by mass or more, and even more preferably 60 to 80% by mass.
  • the mass ratio of the amorphous polyester resin is within this range, the rigidity will be good and the physical properties of the multilayer film can be easily adjusted.
  • the mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass.
  • the mass ratio of the polyolefin resin is within this range, it is possible to obtain a multilayer film that has excellent blocking resistance and has a good peel appearance.
  • the multilayer film of the present invention preferably contains the polyolefin resin in either the seal layer (D) or the surface layer (A). It is more preferable that both of the above-mentioned polyolefin resins are included.
  • the minimum layer structure of the multilayer film of the present invention is a layer structure of surface layer (A)/sealing layer (D), and when the above-mentioned intermediate layer (C) is provided, surface layer (A)/intermediate layer (C). It is a multilayer film with a layer structure of / sealing layer (D), and when the above intermediate layer (B) is provided, the layers of surface layer (A) / intermediate layer (B) / intermediate layer (C) / sealing layer (D). It is a multilayer film with a structure.
  • the intermediate layer (B) has a multilayer structure
  • layers such as the surface layer (A)/intermediate layer (B1)/intermediate layer (B2)/intermediate layer (C)/sealing layer (D), etc. It may be a configuration. Moreover, other layers may be included. Due to the configuration, the multilayer film of the present invention has suitable heat sealability and easy peelability, is less prone to blocking during film formation, and has suitable heat resistance that ensures high sealing strength even after high temperature treatment.
  • the multilayer film of the present invention more preferably includes the intermediate layer (C) and/or the intermediate layer (B).
  • the intermediate layer (C) and/or the intermediate layer (B) it becomes easy to adjust the amount of polyolefin resin added in the multilayer film of the present invention, and it becomes possible to improve transparency.
  • the mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more.
  • the polyester resin includes the crystalline polyester resin described above, the amorphous polyester resin described above, and other polyesters. Moreover, it is more preferable that the said mass ratio is 80 mass % or more, and it is still more preferable that it is 90 mass % or more.
  • the multilayer film of the present invention preferably has a film thickness of 5 to 100 ⁇ m, more preferably 10 to 80 ⁇ m, and even more preferably 20 to 60 ⁇ m. If the thickness of the film is within this range, it will be easier to obtain suitable heat sealability, heat resistance, film processability, etc.
  • the thickness of each layer is not particularly limited, but for example, the thickness of the surface layer (A) is preferably 1 to 40 ⁇ m, more preferably 1 to 30 ⁇ m, and 3 to 30 ⁇ m. More preferably, the thickness is 30 ⁇ m.
  • the thickness of the sealing layer (D) is preferably 1 to 30 ⁇ m, more preferably 2 to 20 ⁇ m, and even more preferably 2.5 to 10 ⁇ m.
  • the intermediate layer (C) When the intermediate layer (C) is provided, its thickness is preferably 1 to 30 ⁇ m, more preferably 2 to 20 ⁇ m, and even more preferably 3 to 10 ⁇ m.
  • the thickness is preferably 1 to 60 ⁇ m, more preferably 2 to 50 ⁇ m, and even more preferably 3 to 40 ⁇ m.
  • the intermediate layer (B) is made of multiple layers, for example, when it has a structure of surface layer (A)/intermediate layer (B1)/intermediate layer (B2)/intermediate layer (C)/seal layer (D), etc.
  • the total thickness of the intermediate layer (B1) and the intermediate layer (B2) is preferably within the preferable thickness range of the intermediate layer (B).
  • the multilayer film of the present invention has a structure in which a 12 ⁇ m thick biaxially stretched polyester film is laminated with the sealant film of the present invention on a 100 ⁇ m thick biaxially stretched polyester film with a sealing width of 1 cm.
  • the maximum seal strength is 5 to 20 N/15 mm.
  • it is 6 to 15 N/15 mm.
  • the sealing method is not particularly limited, and methods such as ultrasonic sealing may be used, but heat sealing is particularly preferred.
  • each resin or resin mixture used for the surface layer (A) and the sealing layer (D) may be further added when providing the intermediate layer (C).
  • the resin or resin mixture used for the intermediate layer (C) is further heated and melted in separate extruders to coextrude the resin or resin mixture used for the intermediate layer (B).
  • the order of (A)/(D), the order of (A)/(C)/(D), or the order of (A)/(B)/(C) in a molten state by methods such as the multilayer die method or the feed block method.
  • This coextrusion method is preferable because it allows the ratio of the thickness of each layer to be adjusted relatively freely, and a multilayer film with excellent hygiene and cost performance can be obtained.
  • the multilayer film of the present invention is obtained as a substantially unstretched multilayer film by the above-described manufacturing method, secondary forming such as deep drawing by vacuum forming is also possible.
  • the surface layer (A) in order to improve adhesion with printing ink and suitability for lamination when used as a sealant film for lamination, it is preferable to subject the surface layer (A) to a surface treatment.
  • a surface treatment include surface oxidation treatments such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, ozone/ultraviolet treatment, and surface roughening treatments such as sandblasting. Corona treatment is preferred.
  • the multilayer film of the present invention can also be used by laminating other substrates.
  • the other base material is preferably laminated on the surface layer (A) side.
  • the other base material is not particularly limited, and may be a paper base material such as plain paper or coated paper, a plastic film such as unstretched film or stretched film, or a nonwoven fabric, but recyclability is improved by making it a monomaterial. In order to improve this, a polyester resin film is preferable.
  • the laminating method known methods can be used, including dry lamination using an adhesive, extrusion lamination, and the like.
  • the adhesive used for the laminate any known adhesive can be used, but a two-component curing adhesive of a polyol composition and a polyisocyanate composition is preferred.
  • the two-component curing adhesive may be in either a solvent type or a solvent-free type.
  • the mass of the adhesive after drying is preferably 0.1 to 10 g/m 2 , more preferably 1 to 6 g/m 2 , and even more preferably 2 to 5 g/m 2 Although it is preferable, since it is a monomaterial, it is more preferable to use less adhesive.
  • the multilayer film of the present invention may be used as a lid material as it is, but it is also preferable to use a lid material made of a laminate in which a base film is laminated on the surface layer (A).
  • the base film is not particularly limited as long as it does not impair sealing properties or dead-hold properties, but examples include biaxially oriented polyester (PET), easily tearable biaxially oriented polyester (PET), and biaxially oriented polypropylene.
  • OPP coextruded biaxially oriented polypropylene with ethylene vinyl alcohol copolymer (EVOH) as the center layer
  • EVOH ethylene vinyl alcohol copolymer
  • PVDC polyvinylidene chloride
  • Examples include axially oriented polypropylene and biaxially oriented nylon.
  • One type or two or more of these base films may be used in combination, but from the viewpoint of monomaterialization, the laminated film should be biaxially oriented polyester (PET) or easily tearable biaxially oriented polyester (PET). ) is preferably a polyester resin.
  • the bonding method include methods such as dry lamination, wet lamination, non-solvent lamination, and extrusion lamination.
  • Examples of the adhesive used in the dry lamination include polyether-polyurethane adhesives, polyester-polyurethane adhesives, and the like.
  • the lid material of the present invention is used as a lid material for tightly sealing a container having an opening with a seal. It can be preferably applied to containers in which the heat-sealed portion) is made of polyester resin. In particular, since the heat-sealing part can achieve suitable sealing performance and heat resistance even for containers whose main component is crystallized polyethylene terephthalate (C-PET), lids for crystallized polyethylene terephthalate (C-PET) containers can be used. It can also be preferably used as a material. It can also be preferably used as a lid material for a paper PET container consisting of a paper layer and a polyethylene terephthalate (PET) resin layer.
  • C-PET crystallized polyethylene terephthalate
  • Examples of the packaging material made of the multilayer film of the present invention include packaging bags and packaging containers used for foods, medicines, industrial parts, miscellaneous goods, magazines, and the like.
  • the packaging bag is preferably a packaging bag formed by stacking and sealing the sealing layers of the multilayer film of the present invention, or by stacking and sealing the outermost layer and the sealing layer.
  • the packaging bag can also be made from a laminate film using the multilayer film of the present invention.
  • two sheets of the multilayer film are cut to the desired size, stacked on top of each other and sealed on three sides to form a bag, and then the contents are inserted from the unsealed side. It can be used as a packaging bag by filling it with something and sealing it.
  • the multilayer film of the present invention can also be used to form a packaging bag/container by overlapping and sealing the seal layer (D) of the multilayer film with another sealable film.
  • a film such as LDPE or EVA, which has relatively low mechanical strength, can be used.
  • the other film is a polyester film.
  • arbitrary tear initiation parts such as V notches, I notches, perforations, micropores, etc. are formed in the sealing part in order to weaken the initial tear strength and improve the ease of opening. It is preferable to do so.
  • Example 1 The following resins were used as resin components for forming each layer of the surface layer (A) and the seal layer (D), and resins and resin mixtures for forming each layer were prepared. These resins and resin mixtures are supplied to an extruder and melted, and the molten resin is supplied to a coextrusion multilayer film manufacturing apparatus using a T-die chill roll method having a feed block, and the layer structure of the film is changed by co-melt extrusion. A multilayer film with a two-layer structure of surface layer (A)/sealing layer (D), a thickness ratio of each layer of 80%/20%, and a total thickness of 30 ⁇ m was obtained.
  • Example 2 A multilayer film was obtained in the same manner as in Example 1, except that the resins used for the surface layer (A) and the seal layer (D) were as follows.
  • Example 3 A multilayer film was obtained in the same manner as in Example 2 except that the resin used for the surface layer was as follows.
  • Example 4 The following resins were used as resin components to form each layer of the surface layer (A), middle layer (B), middle layer (C), and sealing layer (D), and the resins and resin mixtures forming each layer were It was adjusted. These resins and resin mixtures are supplied to an extruder and melted, and the molten resin is supplied to a coextrusion multilayer film manufacturing apparatus using a T-die chill roll method having a feed block, and the layer structure of the film is changed by co-melt extrusion.
  • Example 5 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
  • Example 6 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows. Seal layer (D): 95 parts of crystalline polyester (3) (d1), 5 parts of propylene block copolymer (1) (d3)
  • Example 7 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows. Seal layer (D): 90 parts of crystalline polyester (3) (d1), 10 parts of propylene block copolymer (1) (d3)
  • Example 8 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows. Seal layer (D): 80 parts of crystalline polyester (3) (d1), 20 parts of propylene block copolymer (1) (d3)
  • Example 9 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
  • Example 10 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows. Seal layer (D): 75 parts of crystalline polyester (3) (d1), 15 parts of amorphous polyester (2) (d2), 10 parts of propylene block copolymer (1) (d3)
  • Example 11 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A) and the seal layer (D) were as follows.
  • Example 12 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the intermediate layer (C) and the seal layer (D) were as follows.
  • Example 13 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the intermediate layer (C) and the seal layer (D) were as follows.
  • Example 14 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A) and the seal layer (D) were as follows.
  • Example 15 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
  • Intermediate layer (C) 10 parts of crystalline polyester (3) (c1), Crystalline polyester (1) (c2) 90 parts
  • Example 16 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
  • Example 17 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
  • Example 1 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
  • Intermediate layer (B) 10 parts of crystalline polyester (3) (b1), amorphous Polyester (2) (b2) 90 parts
  • Example 2 A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and seal layer (D) were as follows.
  • Seal strength is the maximum strength when the inner film part of the heat-sealed flange part of the obtained sample is cut out to a width of 15 mm, grasped with the tip of the push-pull gauge, and the lid material is peeled off at an angle of 90 degrees from the horizontal plane of the flange. And so. Evaluation was made based on the following criteria. ⁇ : 10N/15mm or more ⁇ : 7-9N/15mm ⁇ : Less than 7N/15mm
  • the multilayer films of the present invention of Examples 1 to 17 can exhibit suitable film processability and blocking resistance, have excellent transparency, and have good crystallized polyethylene terephthalate (C- It achieved both opening strength and sealing strength against PET). Moreover, the appearance after peeling was good with no film remaining.
  • the multilayer films of Examples 4 to 17 having an intermediate layer it was easy to adjust the content of the polyolefin resin, so it was easy to maintain transparency and other properties suitably.
  • the multilayer films of Nos. 14 and 15 were easy to achieve both easy peelability, seal strength, and peel appearance.
  • the multilayer films of Comparative Examples 1 and 2 were unable to have suitable film processability, easy opening, and high seal strength.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)

Abstract

The present invention provides a multilayer film comprising a sealing layer (D) and a surface layer (A). The multilayer film is characterized in that: the mass ratio of a polyester resin with respect to the entire resin constituting the multilayer film is 70 mass% or more; the mass ratio of a crystallizable polyester resin with respect to the entire resin constituting the multilayer film is 10 mass% or more; the mass ratio of a non-crystallizable polyester resin with respect to the entire resin constituting the multiplayer film is 20 mass% or more; and the mass ratio of a polyolefin resin with respect to the entire resin constituting the multilayer film is 1 mass% or more.

Description

多層フィルム、蓋材及び包装材Multilayer films, lids and packaging materials
　本発明は、食品や医療品等の包装材に使用する多層フィルム、蓋材及び包装材に関する。 The present invention relates to a multilayer film, a lid material, and a packaging material used for packaging materials such as foods and medical products.
　従来、食品や医療品等の各種樹脂容器の開口部を、多層フィルムを使用した蓋材により密封、封止した容器が用いられている。これら容器の蓋材としては、通常、内容物を容易に取り出せるよう簡易に開封可能であると共に、内容物が容易に漏洩しない好適なシール性が求められている。また、近年では内容物の長期保存や衛生面の観点から高温殺菌処理がなされる用途も多く、これらシール性や易開封性に加え、高温処理後にも好適にシール強度を保持できる高い耐熱性が求められている。 BACKGROUND ART Conventionally, containers have been used in which the openings of various resin containers for foods, medical products, etc. are sealed with a lid material using a multilayer film. The lids of these containers are generally required to be easily opened so that the contents can be easily taken out, and to have suitable sealing properties so that the contents do not easily leak. In addition, in recent years, there are many applications where high temperature sterilization treatment is performed from the viewpoint of long-term preservation and hygiene of contents, and in addition to these sealing properties and easy opening, high heat resistance that can maintain seal strength even after high temperature treatment is required. It has been demanded.
　このような容器の蓋材に使用されるフィルムとして、出願人は、表面層に結晶性ポリエステル（ａ１）とプロピレンブロック共重合体を、シール層に結晶性ポリエステル（ａ１）を使用した易剥離性フィルムを発明した（特許文献１参照）。この易剥離性フィルムは、好適なヒートシール性、易開封性、フィルム加工性を有し、ブロッキングが生じにくく、高いシール強度を有する多層フィルムであった。 As a film used for the lid material of such containers, the applicant has developed an easily peelable film that uses crystalline polyester (a1) and propylene block copolymer for the surface layer and crystalline polyester (a1) for the sealing layer. invented a film (see Patent Document 1). This easily peelable film was a multilayer film that had suitable heat-sealability, easy-openability, and film processability, was resistant to blocking, and had high sealing strength.
特開２０２１－１０２３０１号公報Japanese Patent Application Publication No. 2021-102301
　一方、上記易剥離性フィルムは、高耐熱性の容器として使用されている結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）に対するシール強度が非常に高く、易剥離しづらく、剥離後に膜残りを生じる可能性があった。また、透明性がやや低く、内容物視認性に劣る場合があった。 On the other hand, the above-mentioned easily peelable film has a very high sealing strength against crystallized polyethylene terephthalate (C-PET), which is used as a highly heat-resistant container, and is difficult to peel and may leave film residue after peeling. there were. In addition, the transparency was somewhat low, and the visibility of the contents was sometimes poor.
　本発明が解決しようとする課題は、透明性やフィルム加工性に優れるとともに、結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）容器に使用した際にも良好なシール強度と開封強度を両立し、膜残りせず剥離後の外観が良好な多層フィルムを提供することにある。 The problem to be solved by the present invention is to achieve both excellent transparency and film processability, as well as good sealing strength and opening strength when used in crystallized polyethylene terephthalate (C-PET) containers, and to avoid film residue. The first object of the present invention is to provide a multilayer film that has a good appearance after peeling.
　本発明は、シール層（Ｄ） と、表面層（Ａ）とを有する多層フィルムであって、前記多層フィルムを構成する樹脂全体  に対するポリエステル系樹脂の質量比率が、７０質量％以上であり、前記多層フィルムを構成する樹脂全体に対する結晶性ポリエステル系樹脂の質量比率が１０質量％以上であり、前記多層フィルムを構成する樹脂全体に対する非晶性ポリエステル系樹脂の質量比率が２０質量％以上であり、前記多層フィルムを構成する樹脂全体に対するポリオレフィン系樹脂の質量比率が１質量％以上であることを特徴とする多層フィルムにより、上記課題を解決するものである。 The present invention provides a multilayer film having a sealing layer (D) and a surface layer (A), wherein the mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more, and the The mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more, and the mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more, The above problem is solved by a multilayer film characterized in that the mass ratio of polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more.
　本発明の多層フィルムは、好適なシール性と易開封性とを有することから、各種樹脂容器の開口部を密封、封止する蓋材として好適に適用できる。特に、高温処理可能な結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）容器においても易開封性を確保できることから、高温殺菌処理がなされる食品や医療品等の用途に特に好適に適用できる。 Since the multilayer film of the present invention has suitable sealing properties and easy opening properties, it can be suitably applied as a lid material for sealing and sealing the openings of various resin containers. In particular, since easy-opening can be ensured even in high-temperature processable crystallized polyethylene terephthalate (C-PET) containers, the present invention is particularly suitable for use in foods, medical products, etc. that are subject to high-temperature sterilization.
　本発明の多層フィルムは、シール層（Ｄ） と、表面層（Ａ）とを有する多層フィルムであって、前記多層フィルムを構成する樹脂全体  に対するポリエステル系樹脂の質量比率が、７０質量％以上であり、前記多層フィルムを構成する樹脂全体に対する結晶性ポリエステル系樹脂の質量比率が１０質量％以上であり、前記多層フィルムを構成する樹脂全体に対する非晶性ポリエステル系樹脂の質量比率が２０質量％以上であり、前記多層フィルムを構成する樹脂全体に対するポリオレフィン系樹脂の質量比率が１質量％以上であることを特徴とする多層フィルムである。 The multilayer film of the present invention is a multilayer film having a sealing layer (D) and a surface layer (A), wherein the mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more. Yes, the mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more, and the mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more. The multilayer film is characterized in that the mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more.
　［シール層（Ｄ）］
　本発明の多層フィルムのシール層（Ｄ）は、結晶性ポリエステル（ｄ１）、非晶性ポリエステル（ｄ２）及びポリオレフィン系樹脂（ｄ３）のいずれか２種以上を含有することが好ましく、結晶性ポリエステル（ｄ１）、非晶性ポリエステル（ｄ２）及びポリオレフィン系樹脂（ｄ３）を含有することがさらに好ましい。当該シール層（Ｄ）を使用することで、耐ブロッキング性を有し、また、開封性に優れ、膜残りせず良好な剥離外観を有する多層フィルムを実現できる。 [Seal layer (D)]
The sealing layer (D) of the multilayer film of the present invention preferably contains any two or more of crystalline polyester (d1), amorphous polyester (d2), and polyolefin resin (d3). (d1), an amorphous polyester (d2), and a polyolefin resin (d3) are more preferably contained. By using the sealing layer (D), it is possible to realize a multilayer film that has anti-blocking properties, excellent unsealability, and a good peeling appearance without leaving any film residue.
　（結晶性ポリエステル（ｄ１））
　上記結晶性ポリエステル（ｄ１）は、多価カルボン酸と多価アルコールとを重縮合して製造されるポリエステル樹脂であり、結晶性を有するものである。具体的には、樹脂骨格中の一部に規則的配列構造に由来するラメラ結晶型や球晶型等の結晶構造を有するものである。このような結晶性ポリエステルは、示差走査熱量分析（ＤＳＣ）において、結晶構造が熱により融解する際に発生する単独又は複数の結晶融解熱に由来する吸熱ピークを有することを特徴とする。 (Crystalline polyester (d1))
The crystalline polyester (d1) is a polyester resin produced by polycondensing a polyhydric carboxylic acid and a polyhydric alcohol, and has crystallinity. Specifically, a part of the resin skeleton has a crystal structure such as a lamellar crystal type or a spherulite type derived from a regularly arranged structure. Such a crystalline polyester is characterized by having an endothermic peak derived from the heat of fusion of one or more crystals generated when the crystal structure is melted by heat in differential scanning calorimetry (DSC).
　本発明において、結晶性ポリエステルや非晶性ポリエステル等のポリエステル樹脂の融点（Ｔｍ）は、日本工業規格（ＪＩＳ　Ｋ７１２１）に準ずる方法、すなわち示差走査熱量分析（ＤＳＣ）法により求められる値であり、具体的には、下記条件の示差走査熱量分析機を用いて測定される値である。
　測定装置　；株式会社日立ハイテク製　ＤＳＣ－７０２０
　試料：アルミ容器に試料を５ｍｇ程度入れ、蓋をする。
　測定条件　；
　１．－５０℃から２８０℃まで昇温（１０℃／分）
　２．２８０にて５分間保持
　３．２８０℃から２５℃まで降温（１０℃／分）
　４．２５℃で５分間保持
　５．２５℃から２８０℃まで昇温（１０℃／分）
　解析　；５の測定結果において、吸熱ピークが最大となる温度を融点（Ｔｍ）とする。 In the present invention, the melting point (Tm) of polyester resins such as crystalline polyester and amorphous polyester is a value determined by a method according to Japanese Industrial Standards (JIS K7121), that is, a differential scanning calorimetry (DSC) method, Specifically, it is a value measured using a differential scanning calorimeter under the following conditions.
Measuring device: DSC-7020 manufactured by Hitachi High-Tech Corporation
Sample: Put about 5 mg of sample into an aluminum container and cover with a lid.
Measurement condition ;
1. Temperature increase from -50℃ to 280℃ (10℃/min)
2. Hold at 280℃ for 5 minutes 3. Lower temperature from 280℃ to 25℃ (10℃/min)
4. Hold at 25℃ for 5 minutes 5. Increase temperature from 25℃ to 280℃ (10℃/min)
Analysis; In the measurement results of step 5, the temperature at which the endothermic peak is maximum is defined as the melting point (Tm).
　上記多価カルボン酸としては、フタル酸、無水フタル酸、テレフタル酸、イソフタル酸、オルソフタル酸、ナフタレンジカルボン酸、及びトリメリット酸等の芳香族多価カルボン酸、並びにコハク酸、アジピン酸、アゼライン酸、セバシン酸、デカン酸、ウンデカン二酸、ドデカン二酸、トリデカン二酸、テトラデカン二酸、ヘプタデカン二酸、ヘキサデカン二酸、ヘプタデカン二酸、オクタデカン二酸、ダイマー酸、及びシクロヘキサンジカルボン酸等の脂肪族多価カルボン酸が挙げられる。
　これらはそれぞれ単独で使用しても良いし、二種類以上を併用しても良い。
　また、必要に応じて、その原料成分に、メタン酸、エタン酸、プロパン酸、ブタン酸、ペンタン酸、ヘキサン酸、ヘプタン酸、オクタン酸、ノナン酸、デカン酸、ドデカン酸、テトラデカン酸、ヘキサデカン酸、ヘプタデカン酸、オクタデカン酸等のモノカルボン酸を用いても良い。 The polycarboxylic acids mentioned above include aromatic polycarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, and trimellitic acid, as well as succinic acid, adipic acid, and azelaic acid. , sebacic acid, decanoic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, heptadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid. Examples include polycarboxylic acids.
These may be used alone or in combination of two or more.
In addition, as necessary, the raw material components may include methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid. , heptadecanoic acid, octadecanoic acid, and other monocarboxylic acids may also be used.
　上記多価アルコールとしては、エチレングリコール、ジエチレングリコール、プロピレングリコール、２－メチル－１，３－プロパンジオール、２，２－ジメチルトリメチレングリコール、１，４－ブタンジオール、１，５－ペンタンジオール、３－メチルペンタンジオール、１，６－ヘキサンジオール、１，７－ヘプタンジオール、１，８－オクタンジオール、１，９－ノナンジオール、１，１０－デカンジオール、１，１２－ドデカンジオール、１，１６－ヘキサデカンジオール、１，１８－オクタデカンジオール、１，２０－イコサンジオール、１，４－シクロヘキサンジメタノール、ポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコール、ネオペンチルグリコール、ペンタエチレングリコール、及びトリメチロールプロパン等の多価アルコールが挙げられる。 Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyltrimethylene glycol, 1,4-butanediol, 1,5-pentanediol, -Methylpentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,16 - hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol, pentaethylene glycol, and trimethylolpropane Polyhydric alcohols such as
　上記の多価カルボン酸と多価アルコールとは、任意の組み合わせにより用いられる。具体的には、テレフタル酸／エチレングリコール共重合体、テレフタル酸／１，４ブタンジオール共重合体、テレフタル酸／１，４－ブタンジオール／アジピン酸共重合体、テレフタル酸／ポリテトラメチレンエーテルグリコール／１，４ブタンジオール共重合体、テレフタル酸／イソフタル酸／１，４ブタンジオール／ポリテトラメチレンエーテルグリコール共重合体、テレフタル酸／イソフタル酸／１，４ブタンジオール共重合体、等が挙げられる。 The above polyhydric carboxylic acid and polyhydric alcohol may be used in any combination. Specifically, terephthalic acid/ethylene glycol copolymer, terephthalic acid/1,4-butanediol copolymer, terephthalic acid/1,4-butanediol/adipic acid copolymer, terephthalic acid/polytetramethylene ether glycol /1,4-butanediol copolymer, terephthalic acid/isophthalic acid/1,4-butanediol/polytetramethylene ether glycol copolymer, terephthalic acid/isophthalic acid/1,4-butanediol copolymer, etc. .
　上記結晶性ポリエステル（ｄ１）の融点は１００～２００℃であることが好ましく、１１０～１８０℃であることがより好ましい。当該融点の結晶性ポリエステルを使用することで、押出成形性が良好となる。また、当該結晶性ポリエステル（ｄ１）のガラス転移温度は、４０℃以下であることが好ましく、０℃以下であることがより好ましく、－２０℃以下であることがより好ましい。当該ガラス転移温度の結晶性ポリエステル（ｄ１）を使用することで、ヒートシール性や易開封性が良好となる。このような結晶性ポリエステル（ｄ１）としては、例えば、商品名「バイロン」（東洋紡株式会社）で市販されている樹脂が挙げられる。 The melting point of the crystalline polyester (d1) is preferably 100 to 200°C, more preferably 110 to 180°C. By using a crystalline polyester having the above melting point, extrusion moldability becomes good. Further, the glass transition temperature of the crystalline polyester (d1) is preferably 40°C or lower, more preferably 0°C or lower, and even more preferably -20°C or lower. By using the crystalline polyester (d1) having the glass transition temperature, heat sealing properties and easy opening properties are improved. Examples of such crystalline polyester (d1) include resins commercially available under the trade name "Vylon" (Toyobo Co., Ltd.).
　なお、ポリエステル樹脂のガラス転移温度（Ｔｇ）は、日本工業規格（ＪＩＳ　Ｋ７１２１）に準ずる方法、すなわち示差走査熱量分析（ＤＳＣ）法により求められる値である。 Note that the glass transition temperature (Tg) of the polyester resin is a value determined by a method according to Japanese Industrial Standards (JIS K7121), that is, a differential scanning calorimetry (DSC) method.
　（非晶性ポリエステル（ｄ２））
　上記非晶性ポリエステル（ｄ２）は、多価カルボン酸と多価アルコールとを重縮合して製造されるポリエステル樹脂であり、実質的に結晶性を示さないポリエステルである。特に、結晶性ポリエステル（ｄ１）において先に説明した示差走査熱量計による融点測定において、５０℃～２８０℃の温度範囲にて明確な融解ピーク温度を有さないポリエステルであり、具体的にはこの温度範囲において、結晶融解熱量（ΔＨ）が１Ｊ／ｇ以下であるものを意味する。 (Amorphous polyester (d2))
The amorphous polyester (d2) is a polyester resin produced by polycondensing a polyhydric carboxylic acid and a polyhydric alcohol, and is a polyester that does not substantially exhibit crystallinity. In particular, crystalline polyester (d1) is a polyester that does not have a clear melting peak temperature in the temperature range of 50°C to 280°C when measured using a differential scanning calorimeter as explained above. In the temperature range, it means that the heat of crystal fusion (ΔH) is 1 J/g or less.
　上記多価カルボン酸としては、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ヘキサヒドロフタル酸、１，４－シクロヘキサンジカルボン酸、マレイン酸、無水マレイン酸、シトラコン酸、ジメチルマレイン酸、シクロペンテン－１，２－ジカルボン酸、１－シクロへキセン－１，２－ジカルボン酸、４－シクロへキセン－１，２－ジカルボン酸、フマル酸、メサコン酸、イタコン酸、グルタコン酸、フタル酸、無水フタル酸、テレフタル酸、イソフタル酸、オルソフタル酸、１，２，５－ヘキサントリカルボン酸、１，２，４－シクロヘキサントリカルボン酸、トリメリット酸、無水トリメリット酸、１，２，５－ベンゼントリカルボン酸、２，５，７－ナフタレントリカルボン酸、ピロメリット酸、無水ピロメリット酸等が挙げられる。これらはそれぞれ単独で使用しても良いし、二種類以上を併用しても良い。
　また、必要に応じて、その原料成分に、メタン酸、エタン酸、プロパン酸、ブタン酸、ペンタン酸、ヘキサン酸、ヘプタン酸、オクタン酸、ノナン酸、デカン酸、ドデカン酸、テトラデカン酸、ヘキサデカン酸、ヘプタデカン酸、オクタデカン酸等のモノカルボン酸を用いても良い。 Examples of the polyvalent carboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, hexahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, maleic acid, and maleic anhydride. Acid, citraconic acid, dimethylmaleic acid, cyclopentene-1,2-dicarboxylic acid, 1-cyclohexene-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, fumaric acid, mesaconic acid, Itaconic acid, glutaconic acid, phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, 1,2,5-hexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, trimellitic acid, trimellitic anhydride , 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, pyromellitic anhydride and the like. These may be used alone or in combination of two or more.
In addition, as necessary, the raw material components may include methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid. , heptadecanoic acid, octadecanoic acid, and other monocarboxylic acids may also be used.
　上記多価アルコールとしては、エチレングリコール、ジエチレングリコール、プロピレングリコール、２－メチル－１，３－プロパンジオール、２，２－ジメチルトリメチレングリコール、１，４－ブタンジオール、１，５－ペンタンジオール、３－メチルペンタンジオール、１，６－ヘキサンジオール、１，７－ヘプタンジオール、１，８－オクタンジオール、１，９－ノナンジオール、１，１０－デカンジオール、１，１２－ドデカンジオール、１，１６－ヘキサデカンジオール、１，１８－オクタデカンジオール、１，２０－イコサンジオール、１，４－シクロヘキサンジメタノール、ポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコール、ネオペンチルグリコール、ペンタエチレングリコール、イソソルビド、２，２，４，４－テトラメチル－１，３－シクロブタンジオール及びトリメチロールプロパン等の多価アルコールが挙げられる。これらはそれぞれ単独で使用しても良いし、二種類以上を併用しても良い。 Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyltrimethylene glycol, 1,4-butanediol, 1,5-pentanediol, -Methylpentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,16 - Hexadecanediol, 1,18-octadecanediol, 1,20-icosandiol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol, pentaethylene glycol, isosorbide, 2, Examples include polyhydric alcohols such as 2,4,4-tetramethyl-1,3-cyclobutanediol and trimethylolpropane. These may be used alone or in combination of two or more.
　上記の多価カルボン酸と多価アルコールとは、任意の組み合わせにより用いられる。具体的には、テレフタル酸／エチレングリコール／ネオペンチルグリコール共重合体、テレフタル酸／エチレングリコール／１，４－シクロヘキサンジメタノール／イソソルビド共重合体、テレフタル酸／イソフタル酸／エチレングリコール共重合体、テレフタル酸／エチレングリコール／１，４－シクロヘキサンジメタノール共重合体、テレフタル酸／１，４－シクロヘキサンジメタノール／２，２，４，４－テトラメチル－１，３－シクロブタンジオール共重合体等が挙げられる。 The above polyhydric carboxylic acid and polyhydric alcohol may be used in any combination. Specifically, terephthalic acid/ethylene glycol/neopentyl glycol copolymer, terephthalic acid/ethylene glycol/1,4-cyclohexanedimethanol/isosorbide copolymer, terephthalic acid/isophthalic acid/ethylene glycol copolymer, terephthalate Examples include acid/ethylene glycol/1,4-cyclohexanedimethanol copolymer, terephthalic acid/1,4-cyclohexanedimethanol/2,2,4,4-tetramethyl-1,3-cyclobutanediol copolymer, etc. It will be done.
　上記非晶性ポリエステル（ｄ２）のガラス転移温度は、４５～１３０℃であることが好ましく、６０～１２０℃であることがより好ましい。当該ガラス転移温度の非晶性ポリエステル（ｄ２）を使用することで、好適なフィルム加工性、耐熱性を確保できる。このような非晶性ポリエステル（ｄ２）としては、例えば、商品名「ＥＣＯＺＥＮ」（ＳＫケミカル社）で市販されている樹脂が挙げられる。 The glass transition temperature of the amorphous polyester (d2) is preferably 45 to 130°C, more preferably 60 to 120°C. By using the amorphous polyester (d2) having the glass transition temperature, suitable film processability and heat resistance can be ensured. Examples of such amorphous polyester (d2) include resins commercially available under the trade name "ECOZEN" (SK Chemical Co., Ltd.).
　本発明に使用するシール層（Ｄ）中の上記結晶性ポリエステル（ｄ１）及び非晶性ポリエステル（ｄ２）の合計含有量は、７０質量％以上であると、好適なヒートシール性や耐熱性を得られる点で好ましい。また、好適なフィルム外観が得られる点で、７５質量％以上であることがより好ましく、８０質量％以上であることがより好ましい。当該含有量の上限は特に制限されるものではないが、９９質量％以下であることが好ましく、９５質量％以下であることがより好ましい。また、当該結晶性ポリエステル（ｄ１）と当該非晶性ポリエステル（ｄ２）の含有比率としては、１：９～９：１であることが好ましい。 When the total content of the crystalline polyester (d1) and amorphous polyester (d2) in the sealing layer (D) used in the present invention is 70% by mass or more, suitable heat sealability and heat resistance can be obtained. It is preferable in that it can be obtained. Further, from the viewpoint of obtaining a suitable film appearance, the content is more preferably 75% by mass or more, and more preferably 80% by mass or more. The upper limit of the content is not particularly limited, but is preferably 99% by mass or less, more preferably 95% by mass or less. Further, the content ratio of the crystalline polyester (d1) and the amorphous polyester (d2) is preferably 1:9 to 9:1.
　本発明に使用するシール層（Ｄ）中の上記結晶性ポリエステル（ｄ１）及び非晶性ポリエステル（ｄ２）は、生分解性ポリエステルであってもよい。生分解性ポリエステルとしては、例えば、ポリ乳酸系樹脂、ポリ（ブチレンサクシネート）（ＰＢＳ）、ポリ（ブチレンサクシネート／アジペート）共重合体（ＰＢＳＡ）、ポリ（３－ヒドロキシ酪酸）、３－ヒドロキシ酪酸と３－ヒドロキシ吉草酸の共重合体、３－ヒドロキシ酪酸と４－ヒドロキシ酪酸の共重合体、等のポリヒドロキシアルカノエート類、ポリグリコール酸、ポリカプロラクトン、β－プロピオラクトンやγ－バレロラクトン等の開環重合体等の脂肪族ポリエステル化合物、アジピン酸と１．４－ブタンジオ－ルとテレフタル酸のコポリエステル（ポリブチレンアジペートテレフタレート）、琥珀酸とエチレングリコールよりなるポリエステル（ポリエチレンサクシネート）等の脂肪族２塩基酸と脂肪族ジオ－ルよりなるポリエステル等、芳香族ポリエステルと脂肪族ポリエステルの共重合物、脂肪族ポリエステルとポリアミドの共重合物、ポリビニルアルコール、プルラン、、キトサン、カードラン、澱粉系グリーンプラ、エステル化澱粉、セルロース、酢酸セルロース等の天然系生分解性樹脂が挙げられる。これらの生分解性ポリエステルも、示差走査熱量分析（ＤＳＣ）において、結晶構造が熱により融解する際に発生する単独又は複数の結晶融解熱に由来する吸熱ピークを有するものを結晶性ポリエステルとして、示差走査熱量計による融点測定において、５０℃～２８０℃の温度範囲にて明確な融解ピーク温度を有さないポリエステルであり、具体的にはこの温度範囲において、結晶融解熱量（ΔＨ）が１Ｊ／ｇ以下であるものを非晶性ポリエステルとして扱う。 The crystalline polyester (d1) and amorphous polyester (d2) in the seal layer (D) used in the present invention may be biodegradable polyesters. Examples of biodegradable polyesters include polylactic acid resin, poly(butylene succinate) (PBS), poly(butylene succinate/adipate) copolymer (PBSA), poly(3-hydroxybutyric acid), and 3-hydroxy Polyhydroxyalkanoates such as copolymers of butyric acid and 3-hydroxyvaleric acid, copolymers of 3-hydroxybutyric acid and 4-hydroxybutyric acid, polyglycolic acid, polycaprolactone, β-propiolactone, and γ-valero. Aliphatic polyester compounds such as ring-opening polymers such as lactones, copolyesters of adipic acid, 1,4-butanediol, and terephthalic acid (polybutylene adipate terephthalate), polyesters made of succinic acid and ethylene glycol (polyethylene succinate) Polyesters made of aliphatic dibasic acids and aliphatic diols, copolymers of aromatic polyesters and aliphatic polyesters, copolymers of aliphatic polyesters and polyamides, polyvinyl alcohol, pullulan, chitosan, curdlan , starch-based green plastic, esterified starch, cellulose, cellulose acetate, and other natural biodegradable resins. These biodegradable polyesters are also classified as crystalline polyesters by differential scanning calorimetry (DSC). It is a polyester that does not have a clear melting peak temperature in the temperature range of 50°C to 280°C when measured by a scanning calorimeter, and specifically, the heat of crystal fusion (ΔH) is 1 J/g in this temperature range. The following are treated as amorphous polyesters:
　（ポリオレフィン系樹脂（ｄ３））
　本発明のシール層（Ｄ）には、ポリオレフィン系樹脂（ｄ３）を含有することが好ましい。当該ポリオレフィン系樹脂（ｄ３）は、相溶しにくい結晶性ポリエステル（ｄ１）と非晶性ポリエステル（ｄ２）中に均一に分散させて、その結果耐ブロッキング性及び剥離外観を良好にする機能を有していると発明者は推測している。
　上記ポリオレフィン系樹脂（ｄ３）としては、エチレン系樹脂やプロピレン系樹脂等を好ましく使用できる。エチレン系樹脂としては超低密度ポリエチレン（ＶＬＤＰＥ）、線状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、線状中密度ポリエチレン（ＬＭＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂等を使用できる。また、プロピレン系樹脂としては、プロピレン単独重合体や、プロピレン－エチレンブテン－１共重合体等のプロピレン－α－オレフィンランダム共重合体、プロピレン－α－オレフィンブロック共重合体等のプロピレンブロック共重合体等が挙げられる。中でも、プロピレンブロック共重合体が好ましい。 (Polyolefin resin (d3))
It is preferable that the seal layer (D) of the present invention contains a polyolefin resin (d3). The polyolefin resin (d3) has the function of uniformly dispersing the crystalline polyester (d1) and the amorphous polyester (d2), which are difficult to miscible with each other, thereby improving blocking resistance and peeling appearance. The inventor assumes that this is the case.
As the polyolefin resin (d3), ethylene resin, propylene resin, etc. can be preferably used. Ethylene resins include very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), linear medium density polyethylene (LMDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). ) and other polyethylene resins can be used. In addition, propylene-based resins include propylene homopolymers, propylene-α-olefin random copolymers such as propylene-ethylene butene-1 copolymer, and propylene block copolymers such as propylene-α-olefin block copolymers. Examples include merging. Among these, propylene block copolymers are preferred.
　上記プロピレンブロック共重合体としては、プロピレンと他のα－オレフィンとを含有する樹脂を使用できる。α－オレフィンとしては、エチレン、１－ブテン、１－ヘキセン、４－メチル・１－ペンテン、１－オクテン等が例示でき、なかでもエチレンが耐熱性や耐衝撃性に優れているため好ましい。プロピレン－エチレンブロック共重合体は、特に限定されないが、例えば第一工程において、プロピレンを主体とした重合体ブロックを重合し、第二工程において、エチレンとプロピレンの共重合体ブロックを重合して得られる。 As the propylene block copolymer, a resin containing propylene and other α-olefins can be used. Examples of the α-olefin include ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, etc. Among them, ethylene is preferred because it has excellent heat resistance and impact resistance. The propylene-ethylene block copolymer is not particularly limited, but can be obtained, for example, by polymerizing a polymer block mainly composed of propylene in the first step and polymerizing a copolymer block of ethylene and propylene in the second step. It will be done.
　上記プロピレンブロック共重合体は、Ｔダイ成膜法において冷却ロール４０℃で、厚み６０μｍとなるように成形した時のプロピレンブロック共重合体の曇り度が３０％以上であることが好ましく、４０％以上であることがより好ましい。当該曇り度の樹脂を使用することで好適な耐ブロッキング性やフィルム加工性が得られる。 The propylene block copolymer preferably has a haze of 30% or more, preferably 40% when molded to a thickness of 60 μm using a cooling roll at 40° C. in the T-die film forming method. It is more preferable that it is above. By using a resin with such haze, suitable blocking resistance and film processability can be obtained.
　上記プロピレンブロック共重合体のメルトフローレート（ＭＦＲ）は、成形が容易であり、また好適な易開封性を得やすいことから、０．５～１０ｇ／１０分（２３０℃、２１．１８Ｎ）であることが好ましく、２～５ｇ／１０分であることがより好ましい。 The melt flow rate (MFR) of the above propylene block copolymer is 0.5 to 10 g/10 minutes (230°C, 21.18N) because it is easy to mold and easy to obtain suitable easy opening properties. The amount is preferably 2 to 5 g/10 minutes, and more preferably 2 to 5 g/10 minutes.
　上記プロピレンブロック共重合体の融点は、成形が容易であり、また優れた耐熱性を確保しやすいことから、１５０℃以上であることが好ましく、１６０℃以上であることがより好ましい。 The melting point of the propylene block copolymer is preferably 150°C or higher, more preferably 160°C or higher, because it is easy to mold and easy to ensure excellent heat resistance.
　本発明のシール層（Ｄ）に上記ポリオレフィン系樹脂（ｄ３）を含有させる場合は、その含有量が、シール層（Ｄ）に含まれる樹脂成分中の１～１８質量％であることが特に好ましい。特に、当該ポリオレフィン系樹脂（ｄ３）として上記プロピレンブロック共重合体を含有させる場合は、その含有量が、シール層（Ｄ）に含まれる樹脂成分中の０．５～３０質量％であることが好ましく、１～２０質量％であることがより好ましく、１～１８質量％であることがさらに好ましい。当該含有量とすることで、好適な耐ブロッキング性やフィルム加工性が得られ、また、透明性及び剥離後に被着体に樹脂残りや膜残りがなく、好適な剥離外観が得られる点でも好ましい。 When the seal layer (D) of the present invention contains the polyolefin resin (d3), it is particularly preferable that the content is 1 to 18% by mass of the resin component contained in the seal layer (D). . In particular, when the propylene block copolymer is contained as the polyolefin resin (d3), the content thereof should be 0.5 to 30% by mass in the resin component contained in the sealing layer (D). It is preferably 1 to 20% by weight, more preferably 1 to 18% by weight. This content is preferable in that it is possible to obtain suitable blocking resistance and film processability, and also to obtain transparency and no resin or film residue on the adherend after peeling, and to obtain a suitable peeled appearance. .
　本発明に使用するシール層（Ｄ）に使用する樹脂としては、上記結晶性ポリエステル（ｄ１）と上記非晶性ポリエステル（ｄ２）とポリオレフィン系樹脂（ｄ３）のいずれか２種以上を使用することが好ましく、これら樹脂のみを使用することも好ましいが、これら樹脂以外の包装用フィルムに使用される各種樹脂を使用してもよい。当該他の樹脂としては、例えば、ポリエチレン系エラストマー、ポリプロピレン系エラストマー、ブテン系エラストマー等の熱可塑性エラストマー；エチレン－酢酸ビニル共重合体（ＥＶＡ）、エチレン－メチルメタアクリレート共重合体（ＥＭＭＡ）、エチレン－エチルアクリレート共重合体（ＥＥＡ）、エチレン－メチルアクリレート（ＥＭＡ）共重合体、エチレン－エチルアクリレート－無水マレイン酸共重合体（Ｅ－ＥＡ－ＭＡＨ）、エチレン－アクリル酸共重合体（ＥＡＡ）、エチレン－メタクリル酸共重合体（ＥＭＡＡ）等のエチレン系共重合体；更にはエチレン－アクリル酸共重合体のアイオノマー、エチレン－メタクリル酸共重合体のアイオノマー等を例示できる。 As the resin used for the sealing layer (D) used in the present invention, two or more of the above crystalline polyester (d1), the above amorphous polyester (d2), and polyolefin resin (d3) may be used. is preferred, and it is also preferred to use only these resins, but various resins used for packaging films other than these resins may also be used. Examples of the other resins include thermoplastic elastomers such as polyethylene elastomers, polypropylene elastomers, and butene elastomers; ethylene-vinyl acetate copolymers (EVA), ethylene-methyl methacrylate copolymers (EMMA), and ethylene. - Ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA) , ethylene-based copolymers such as ethylene-methacrylic acid copolymer (EMAA); further examples include ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers.
　本発明に使用するシール層（Ｄ）に使用する樹脂成分として、上記結晶性ポリエステル（ｄ１）と上記非晶性ポリエステル（ｄ２）と上記ポリオレフィン系樹脂（ｄ３）以外の樹脂を使用する場合には、その含有量が当該シール層（Ｄ）に含まれる樹脂成分中の２０質量％以下であることが好ましく、１０質量％以下であることがより好ましく、５質量％以下であることがさらに好ましい。 When using a resin other than the crystalline polyester (d1), the amorphous polyester (d2), and the polyolefin resin (d3) as the resin component for the seal layer (D) used in the present invention, The content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less in the resin component contained in the seal layer (D).
　本発明に使用するシール層（Ｄ）中には、上記樹脂成分以外に各種添加剤等を適宜併用してもよい。添加剤としては、例えば、滑剤、ブロッキング防止剤、紫外線吸収剤、光安定剤、耐電防止剤、防曇剤等、着色剤等を適宜使用できる。これら添加剤を使用する場合には、当該シール層（Ｄ）に使用する樹脂成分１００質量部に対して、好ましくは２質量部以下、より好ましくは０．０１～１質量部程度で使用する。 In addition to the above-mentioned resin components, various additives and the like may be appropriately used in the seal layer (D) used in the present invention. As additives, for example, lubricants, antiblocking agents, ultraviolet absorbers, light stabilizers, antistatic agents, antifogging agents, colorants, etc. can be used as appropriate. When these additives are used, they are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the sealing layer (D).
　なお、上記添加剤を使用する場合には、好適なヒートシール性を確保しやすいことから、フィラーの含有量、特に無機フィラーの含有量を３００ｐｐｍ以下とすることが好ましく、２００ｐｐｍ以下とすることがより好ましく、１００ｐｐｍ以下とすることがさらに好ましく、実質的に含有しないことが特に好ましい。 In addition, when using the above additives, the filler content, especially the inorganic filler content, is preferably 300 ppm or less, and preferably 200 ppm or less, since it is easy to ensure suitable heat sealability. It is more preferable that the amount is 100 ppm or less, and it is especially preferable that it is substantially not contained.
　本発明に使用するシール層（Ｄ）の多層フィルムの総厚に対する厚み比率は、易開封性やフィルム加工性を得やすいことから、多層フィルムの総厚みに対するシール層（Ｄ）の厚み比率としては、５～３０％の範囲であることが好ましく、１０～２５％の範囲であることがより好ましい。 The thickness ratio of the sealing layer (D) to the total thickness of the multilayer film used in the present invention is as follows: , preferably in the range of 5 to 30%, more preferably in the range of 10 to 25%.
　［表面層（Ａ）］
　本発明の多層フィルムの表面層（Ａ）は、結晶性ポリエステル（ａ１）、非晶性ポリエステル（ａ２）及びポリオレフィン系樹脂（ａ３）のいずれか２種以上を含有することが好ましく、結晶性ポリエステル（ａ１）、非晶性ポリエステル（ａ２）及びポリオレフィン系樹脂（ａ３）を含有することがより好ましい。当該表面層（Ａ）を使用することで、耐ブロッキング性やフィルム加工性が良好となる。 [Surface layer (A)]
The surface layer (A) of the multilayer film of the present invention preferably contains any two or more of crystalline polyester (a1), amorphous polyester (a2), and polyolefin resin (a3); It is more preferable to contain (a1), amorphous polyester (a2) and polyolefin resin (a3). By using the surface layer (A), blocking resistance and film processability are improved.
　上記表面層（Ａ）に使用する結晶性ポリエステル（ａ１）としては、上記シール層（Ｄ）の結晶性ポリエステル（ｄ１）と同様のものを使用でき、好ましいものも同様である。 As the crystalline polyester (a1) used in the surface layer (A), those similar to the crystalline polyester (d1) of the seal layer (D) can be used, and preferred ones are also the same.
　上記表面層（Ａ）に使用する非晶性ポリエステル（ａ２）としては、上記シール層（Ｄ）の非晶性ポリエステル（ｄ２）と同様のものを使用でき、好ましいものも同様である。 As the amorphous polyester (a2) used in the surface layer (A), the same amorphous polyester (d2) as in the seal layer (D) can be used, and preferred ones are also the same.
　上記表面層（Ａ）に使用するポリオレフィン系樹脂（ａ３）としては、上記シール層（Ｄ）のポリオレフィン系樹脂（ｄ３）と同様のものを使用でき、好ましいものも同様である。特に、ポリオレフィン系樹脂（ａ３）として、プロピレンブロック共重合体を使用することが好ましい。当該ポリオレフィン系樹脂（ａ３）を使用することで、フィルムの表面平滑性が低下することによって、耐ブロッキング性が向上し、巻取りロールへのフィルム表面の付着を防ぐことも可能となる。 As the polyolefin resin (a3) used in the surface layer (A), the same ones as the polyolefin resin (d3) in the seal layer (D) can be used, and preferred ones are also the same. In particular, it is preferable to use a propylene block copolymer as the polyolefin resin (a3). By using the polyolefin resin (a3), the surface smoothness of the film is reduced, thereby improving the blocking resistance and making it possible to prevent the film surface from adhering to the take-up roll.
　本発明に使用する表面層（Ａ）に含まれる樹脂成分中の上記ポリオレフィン系樹脂（ａ３）の含有量は、フィルム加工性や透明性を得やすいことから、１～３０質量％が好ましく、１～２５質量％がより好ましく、３～２０質量％がさらに好ましい。 The content of the polyolefin resin (a3) in the resin component contained in the surface layer (A) used in the present invention is preferably 1 to 30% by mass, and 1 to 30% by mass, since film processability and transparency can be easily obtained. It is more preferably 25% by weight, and even more preferably 3-20% by weight.
　本発明に使用する表面層（Ａ）においても、使用する樹脂としては、上記結晶性ポリエステル（ａ１）と上記非晶性ポリエステル（ａ２）と上記ポリオレフィン系樹脂（ａ３）のいずれか２種以上を使用することが好ましく、またこれら樹脂のみを使用することも好ましいが、これら樹脂以外の包装用フィルムに使用される各種樹脂を使用してもよい。当該他の樹脂としては、上記シール層（Ｄ）にて例示した各種樹脂を同様に使用できる。これら他の樹脂を使用する場合には、その含有量が表面層（Ａ）に含まれる樹脂成分中の２０質量％以下であることが好ましく、１０質量％以下であることがより好ましく、５質量％以下であることがさらに好ましい。 Also in the surface layer (A) used in the present invention, two or more of the above crystalline polyester (a1), the above amorphous polyester (a2), and the above polyolefin resin (a3) are used as the resin. It is preferable to use these resins, and it is also preferable to use only these resins, but various resins used for packaging films other than these resins may also be used. As the other resin, the various resins exemplified in the seal layer (D) above can be similarly used. When using these other resins, the content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, and 5% by mass or less in the resin component contained in the surface layer (A). % or less is more preferable.
　上記表面層（Ａ）においても上記シール層（Ｄ）と同様の各種添加剤等を適宜併用してもよい。これら添加剤を使用する場合には、当該表面層（Ａ）に使用する樹脂成分１００質量部に対して、好ましくは２質量部以下、より好ましくは０．０１～１質量部程度で使用する。 In the surface layer (A), various additives similar to those in the seal layer (D) may be used in combination as appropriate. When these additives are used, they are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the surface layer (A).
　フィラーの含有量、特に無機フィラーの含有量についても、シール層（Ｄ）と同様に３００ｐｐｍ以下とすることが好ましく、２００ｐｐｍ以下とすることがより好ましく、１００ｐｐｍ以下とすることがさらに好ましく、実質的に含有しないことが特に好ましい。 The filler content, especially the inorganic filler content, is also preferably 300 ppm or less, more preferably 200 ppm or less, even more preferably 100 ppm or less, similar to the seal layer (D), and substantially It is particularly preferable not to contain it.
　表面層（Ａ）の多層フィルムの総厚に対する厚み比率は、好適なフィルム加工性を得やすいことから、１０～９５％の範囲であることが好ましく、２０～９０％の範囲であることがより好ましい。 The thickness ratio of the surface layer (A) to the total thickness of the multilayer film is preferably in the range of 10 to 95%, more preferably in the range of 20 to 90%, since it is easy to obtain suitable film processability. preferable.
　（中間層（Ｃ））
　本発明の多層フィルムにおいては、上記表面層（Ａ）とシール層（Ｄ）の間に、当該シール層（Ｄ）と直接積層される中間層（Ｃ）を有することも好ましい。
　当該中間層（Ｃ）を設ける場合は、当該中間層が結晶性ポリエステル（ｃ１）及び／又は非晶性ポリエステル（ｃ２）を含有し、前記シール層（Ｄ）に含まれる樹脂成分中の前記結晶性ポリエステル（ｄ１）の質量比率と前記中間層（Ｃ）に含まれる樹脂成分中の結晶性ポリエステル（ｃ１）の質量比率との合計と、前記シール層（Ｄ）に含まれる樹脂成分中の前記非晶性ポリエステル（ｄ２）の質量比率と前記中間層（Ｃ）に含まれる樹脂成分中の非晶性ポリエステル（ｃ２）の質量比率との合計との差が、６０質量％以内であることが好ましく、３０質量％以内であることがより好ましく、２５質量％以内であることがさらに好ましい。
　すなわち、当該シール層（Ｄ）の結晶性ポリエステル（ｄ１）と非晶性ポリエステル（ｄ２）の構成比率に応じて、当該中間層（Ｃ）の結晶性ポリエステル（ｃ１）と非晶性ポリエステル（ｃ２）の構成比率を調整することが好ましい。このような中間層（Ｃ）を設けることで、特に安定した易剥離性を確保しやすくなる。 (Middle layer (C))
In the multilayer film of the present invention, it is also preferable to have an intermediate layer (C) directly laminated with the seal layer (D) between the surface layer (A) and the seal layer (D).
When the intermediate layer (C) is provided, the intermediate layer contains a crystalline polyester (c1) and/or an amorphous polyester (c2), and the crystals in the resin component contained in the sealing layer (D) The sum of the mass ratio of the crystalline polyester (d1) and the mass ratio of the crystalline polyester (c1) in the resin component contained in the intermediate layer (C), and the mass ratio of the crystalline polyester (c1) in the resin component contained in the sealing layer (D) The difference between the mass ratio of the amorphous polyester (d2) and the total mass ratio of the amorphous polyester (c2) in the resin component contained in the intermediate layer (C) is within 60 mass%. It is preferably within 30% by mass, more preferably within 25% by mass.
That is, depending on the composition ratio of the crystalline polyester (d1) and the amorphous polyester (d2) in the seal layer (D), the crystalline polyester (c1) and the amorphous polyester (c2) in the intermediate layer (C) ) is preferably adjusted. By providing such an intermediate layer (C), particularly stable and easy peelability can be easily ensured.
　上記結晶性ポリエステル（ｃ１）及び非晶性ポリエステル（ｃ２）としては、上記シール層（Ｄ）で開示した結晶性ポリエステル（ｄ１）及び非晶性ポリエステル（ｄ２）と同様のものを使用でき、好ましいものも同様である。 As the crystalline polyester (c1) and the amorphous polyester (c2), those similar to the crystalline polyester (d1) and the amorphous polyester (d2) disclosed in the seal layer (D) can be used, and are preferable. The same goes for things.
　上記中間層（Ｃ）に含まれる樹脂成分中の上記結晶性ポリエステル（ｃ１）及び／又は非晶性ポリエステル（ｃ２）の合計含有量は、７０～１００質量％とすることが好ましく、８０～１００質量％とすることがより好ましい。当該結晶性ポリエステル（ｃ１）及び／又は非晶性ポリエステル（ｃ２）の合計含有量を当該範囲とすることで、安定した易開封性を確保しやすく、また、透明性も良好となる。 The total content of the crystalline polyester (c1) and/or amorphous polyester (c2) in the resin component contained in the intermediate layer (C) is preferably 70 to 100% by mass, and 80 to 100% by mass. It is more preferable to express it in mass %. By setting the total content of the crystalline polyester (c1) and/or amorphous polyester (c2) within the range, stable easy-openability can be easily ensured, and transparency can also be improved.
　上記中間層（Ｃ）には、さらにポリオレフィン系樹脂（ｃ３）を含有してもよい。当該ポリオレフィン系樹脂（ｃ３）としては、上記シール層（Ｄ）と同様のものを使用でき、好ましいものも同様である。特に、ポリオレフィン系樹脂（ｃ３）としてプロピレンブロック共重合体を使用することが好ましい。当該ポリオレフィン系樹脂（ｃ３）の含有量は、当該中間層（Ｃ）に含まれる樹脂成分中の３０質量％未満とすることが好ましく、２０質量％未満とすることがより好ましい。 The intermediate layer (C) may further contain a polyolefin resin (c3). As the polyolefin resin (c3), the same ones as those for the seal layer (D) can be used, and preferred ones are also the same. In particular, it is preferable to use a propylene block copolymer as the polyolefin resin (c3). The content of the polyolefin resin (c3) is preferably less than 30% by mass, more preferably less than 20% by mass, in the resin component contained in the intermediate layer (C).
　上記中間層（Ｃ）において、樹脂成分として上記結晶性ポリエステル（ｃ１）と上記非晶性ポリエステル（ｃ２）のみを使用することも好ましいが、さらにポリオレフィン系樹脂（ｃ３）を使用してもよいし、これら樹脂以外の包装用フィルムに使用される各種樹脂を使用してもよい。当該他の樹脂としては、上記シール層（Ｄ）にて例示した各種樹脂を同様に使用できる。これら他の樹脂を使用する場合には、その含有量が中間層（Ｃ）に含まれる樹脂成分中の２０質量％未満であることが好ましく、１０質量％未満であることがより好ましく、５質量％未満であることがさらに好ましい。 In the intermediate layer (C), it is preferable to use only the crystalline polyester (c1) and the amorphous polyester (c2) as resin components, but a polyolefin resin (c3) may also be used. Various resins used for packaging films other than these resins may also be used. As the other resin, the various resins exemplified in the seal layer (D) above can be similarly used. When using these other resins, the content thereof is preferably less than 20% by mass, more preferably less than 10% by mass, and 5% by mass in the resin component contained in the intermediate layer (C). More preferably, it is less than %.
　上記中間層（Ｃ）においても上記シール層（Ｄ）と同様の各種添加剤等を適宜併用してもよい。これら添加剤を使用する場合には、当該中間層（Ｃ）に使用する樹脂成分１００質量部に対して、好ましくは２質量部以下、より好ましくは０．０１～１質量部程度で使用する。 Also in the intermediate layer (C), various additives similar to those in the seal layer (D) may be used in combination as appropriate. When these additives are used, they are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the intermediate layer (C).
　上記中間層（Ｃ）を設ける場合には、多層フィルムの総厚みに対する当該中間層（Ｃ）の厚み比率が、５～８０％の範囲であることが好ましく、１０～７０％の範囲であることがより好ましい。 When the intermediate layer (C) is provided, the thickness ratio of the intermediate layer (C) to the total thickness of the multilayer film is preferably in the range of 5 to 80%, and preferably in the range of 10 to 70%. is more preferable.
　（中間層（Ｂ））
　本発明の多層フィルムは、上記表面層（Ａ）と中間層（Ｃ）とシール層（Ｄ）の他に、中間層（Ｂ）を設けても良い。当該中間層（Ｂ）は、当該表面層（Ａ）と中間層（Ｃ）の間に位置する。中間層（Ｂ）は二層以上の複数層で構成してもよい。 (Middle layer (B))
The multilayer film of the present invention may include an intermediate layer (B) in addition to the surface layer (A), intermediate layer (C), and sealing layer (D). The intermediate layer (B) is located between the surface layer (A) and the intermediate layer (C). The intermediate layer (B) may be composed of two or more layers.
　上記中間層（Ｂ）は、樹脂成分として結晶性ポリエステル（ｂ１）及び／又は非晶性ポリエステル（ｂ２）を含有することが好ましい。また、当該中間層（Ｂ）に含まれる樹脂成分中の当該結晶性ポリエステル（ｂ１）と非晶性ポリエステル（ｂ２）の合計質量比率は、８０質量％以上であることが好ましく、９０質量％以上であることがより好ましい。さらに、当該中間層（Ｂ）に含まれる樹脂成分中の結晶性ポリエステル（ｂ１）の質量比率が非晶性ポリエステル（ｂ２）より少ない方が、コストの面から好ましい。
　また、当該中間層（Ｂ）を複数層構成とする場合には、各層が結晶性ポリエステル（ｂ１）と非晶性ポリエステル（ｂ２）とを含有し、中間層（Ｂ）に含まれる樹脂成分中の結晶性ポリエステル（ｂ１）の含有量が０～５０質量％、非晶性ポリエステル（ｂ２）の含有量が５０～１００質量％の層とすることで、本発明の効果を好適に実現できる。なお、当該中間層（Ｂ）を複数層とする場合には、当該配合範囲であれば、各層が同一の配合であっても、異なる配合であってもよい。 The intermediate layer (B) preferably contains crystalline polyester (b1) and/or amorphous polyester (b2) as a resin component. Further, the total mass ratio of the crystalline polyester (b1) and the amorphous polyester (b2) in the resin component contained in the intermediate layer (B) is preferably 80% by mass or more, and 90% by mass or more. It is more preferable that Furthermore, from the viewpoint of cost, it is preferable that the mass ratio of the crystalline polyester (b1) in the resin component contained in the intermediate layer (B) is smaller than that of the amorphous polyester (b2).
In addition, when the intermediate layer (B) has a multi-layer structure, each layer contains crystalline polyester (b1) and amorphous polyester (b2), and the resin component contained in the intermediate layer (B) contains The effects of the present invention can be suitably achieved by forming a layer in which the content of the crystalline polyester (b1) is 0 to 50% by mass and the content of the amorphous polyester (b2) is 50 to 100% by mass. In addition, when the said intermediate|middle layer (B) is made into multiple layers, each layer may have the same composition or a different composition as long as it is the said composition range.
　上記中間層（Ｂ）の厚み比率は、２０～９０％であることが好ましく、４０～７０％であることがより好ましい。
　中間層（Ｂ）を複数層とする場合には、中間層（Ｂ）の総厚が多層フィルムの総厚みに対して２０～９０％であることが好ましく、４０～７０％であることがより好ましい。 The thickness ratio of the intermediate layer (B) is preferably 20 to 90%, more preferably 40 to 70%.
When the intermediate layer (B) is a plurality of layers, the total thickness of the intermediate layer (B) is preferably 20 to 90% of the total thickness of the multilayer film, and more preferably 40 to 70%. preferable.
　［多層フィルム］
　本発明の多層フィルムは、上記シール層（Ｄ）及び表面層（Ａ）を有するフィルムである。また、前記多層フィルムを構成する樹脂全体に対する結晶性ポリエステル系樹脂の質量比率が１０質量％以上、前記多層フィルムを構成する樹脂全体に対する非晶性ポリエステル系樹脂の質量比率が２０質量％以上、前記多層フィルムを構成する樹脂全体に対するポリオレフィン系樹脂の質量比率が１質量％以上である。なお、結晶性ポリエステル系樹脂とは、結晶性ポリエステル（ａ１）、結晶性ポリエステル（ｂ１）、結晶性ポリエステル（ｃ１）、結晶性ポリエステル（ｄ１）及びその他の結晶性ポリエステル系樹脂を含み、非晶性ポリエステル系樹脂とは、非晶性ポリエステル（ａ２）、非晶性ポリエステル（ｂ２）、非晶性ポリエステル（ｃ２）、非晶性ポリエステル（ｄ２）及びその他の非晶性ポリエステル系樹脂を含み、ポリオレフィン系樹脂とは、ポリオレフィン系樹脂（ａ３）、ポリオレフィン系樹脂（ｂ３）、ポリオレフィン系樹脂（ｃ３）、ポリオレフィン系樹脂（ｄ３）及びその他のポリオレフィン系樹脂を含む。 [Multilayer film]
The multilayer film of the present invention is a film having the seal layer (D) and the surface layer (A). Further, the mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more, the mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more, and the The mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more. Note that crystalline polyester resin includes crystalline polyester (a1), crystalline polyester (b1), crystalline polyester (c1), crystalline polyester (d1), and other crystalline polyester resins, and includes amorphous polyester resins. Polyester resin includes amorphous polyester (a2), amorphous polyester (b2), amorphous polyester (c2), amorphous polyester (d2) and other amorphous polyester resins, The polyolefin resin includes polyolefin resin (a3), polyolefin resin (b3), polyolefin resin (c3), polyolefin resin (d3), and other polyolefin resins.
　本発明の多層フィルムを構成する樹脂全体に対する上記結晶性ポリエステル系樹脂の質量比率は、１０質量％以上であり、２０質量％以上であることがより好ましく、２０～５０質量％以上であることがより好ましく、２０～４０質量％であることがさらに好ましい。当該結晶性ポリエステル系樹脂の質量比率がこの範囲であると、高い透明性と良好な剥離外観を両立しやすくなる。
　また、当該多層フィルム全体に対する上記非晶性ポリエステル系樹脂の質量比率は、２０質量％以上であり、５０質量％以上であることがより好ましく、６０～８０質量％であることがさらに好ましい。当該非晶性ポリエステル系樹脂の質量比率がこの範囲であると、剛性が良好となり、多層フィルムの物性調整が容易になる。
　さらに、当該多層フィルムを構成する樹脂全体に対するポリオレフィン系樹脂の質量比率は、１～２０質量％であることがより好ましく、２～１０質量％であることがさらに好ましい。当該ポリオレフィン系樹脂の質量比率がこの範囲であると、耐ブロッキング性に優れ、剥離外観の良好な多層フィルムを得ることができる。 The mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film of the present invention is 10% by mass or more, more preferably 20% by mass or more, and preferably 20 to 50% by mass or more. The content is more preferably 20 to 40% by mass. When the mass ratio of the crystalline polyester resin is within this range, it becomes easy to achieve both high transparency and good peeling appearance.
Furthermore, the mass ratio of the amorphous polyester resin to the entire multilayer film is 20% by mass or more, more preferably 50% by mass or more, and even more preferably 60 to 80% by mass. When the mass ratio of the amorphous polyester resin is within this range, the rigidity will be good and the physical properties of the multilayer film can be easily adjusted.
Furthermore, the mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass. When the mass ratio of the polyolefin resin is within this range, it is possible to obtain a multilayer film that has excellent blocking resistance and has a good peel appearance.
　本発明の多層フィルムは、ブロッキング防止のため、上記シール層（Ｄ）及び表面層（Ａ）のいずれかに、上記ポリオレフィン系樹脂を含むことが好ましく、上記シール層（Ｄ）及び表面層（Ａ）の両方に上記ポリオレフィン系樹脂を含むことがより好ましい。 In order to prevent blocking, the multilayer film of the present invention preferably contains the polyolefin resin in either the seal layer (D) or the surface layer (A). ) It is more preferable that both of the above-mentioned polyolefin resins are included.
　本発明の多層フィルムの最小の層構成は表面層（Ａ）／シール層（Ｄ）の層構成であり、上記中間層（Ｃ）を設ける場合には表面層（Ａ）／中間層（Ｃ）／シール層（Ｄ）の層構成の多層フィルムであり、上記中間層（Ｂ）を設ける場合は表面層（Ａ）／中間層（Ｂ）／中間層（Ｃ）／シール層（Ｄ）の層構成の多層フィルムである。また、中間層（Ｂ）を複数層構成とする場合には、例えば表面層（Ａ）／中間層（Ｂ１）／中間層（Ｂ２）／中間層（Ｃ）／シール層（Ｄ）等の層構成であってもよい。また、その他の層を含んでいてもよい。
　本発明の多層フィルムは、当該構成により、好適なヒートシール性や易剥離性を有し、成膜時のブロッキングが生じにくく、高温処理後にも高いシール強度を確保した好適な耐熱性を有する。 The minimum layer structure of the multilayer film of the present invention is a layer structure of surface layer (A)/sealing layer (D), and when the above-mentioned intermediate layer (C) is provided, surface layer (A)/intermediate layer (C). It is a multilayer film with a layer structure of / sealing layer (D), and when the above intermediate layer (B) is provided, the layers of surface layer (A) / intermediate layer (B) / intermediate layer (C) / sealing layer (D). It is a multilayer film with a structure. In addition, when the intermediate layer (B) has a multilayer structure, for example, layers such as the surface layer (A)/intermediate layer (B1)/intermediate layer (B2)/intermediate layer (C)/sealing layer (D), etc. It may be a configuration. Moreover, other layers may be included.
Due to the configuration, the multilayer film of the present invention has suitable heat sealability and easy peelability, is less prone to blocking during film formation, and has suitable heat resistance that ensures high sealing strength even after high temperature treatment.
　本発明の多層フィルムは、上記中間層（Ｃ）及び／又は中間層（Ｂ）を含むことがより好ましい。当該中間層（Ｃ）及び／又は中間層（Ｂ）を含むことにより、本発明の多層フィルム中のポリオレフィン系樹脂の添加量を調整しやすくなり、透明性を向上させることが可能となる。 The multilayer film of the present invention more preferably includes the intermediate layer (C) and/or the intermediate layer (B). By including the intermediate layer (C) and/or the intermediate layer (B), it becomes easy to adjust the amount of polyolefin resin added in the multilayer film of the present invention, and it becomes possible to improve transparency.
　本発明の多層フィルムは、当該多層フィルムを構成する樹脂全体に対するポリエステル系樹脂の質量比率が、７０質量％以上である。当該ポリエステル系樹脂とは、上記結晶性ポリエステル系樹脂、上記非晶性ポリエステル系樹脂、その他のポリエステルを含む。また、当該質量比率は８０質量％以上であることがより好ましく、９０質量％以上であることが更に好ましい。当該質量比率を７０質量％以上とすることで、フィルムのリサイクル性が向上する。また、９０質量％以上である場合、包材のモノマテリアル化を達成しやすくなり、リサイクル性がさらに向上する。 In the multilayer film of the present invention, the mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more. The polyester resin includes the crystalline polyester resin described above, the amorphous polyester resin described above, and other polyesters. Moreover, it is more preferable that the said mass ratio is 80 mass % or more, and it is still more preferable that it is 90 mass % or more. By setting the mass ratio to 70% by mass or more, the recyclability of the film is improved. Further, when the content is 90% by mass or more, it becomes easier to make the packaging material into a monomaterial, and the recyclability is further improved.
　本発明の多層フィルムは、フィルムの厚さが５～１００μｍのものが好ましく、より好ましくは１０～８０μｍ、さらに好ましくは２０～６０μｍである。フィルムの厚さがこの範囲であれば、好適なヒートシール性や耐熱性、フィルム加工性等を得やすくなる。 The multilayer film of the present invention preferably has a film thickness of 5 to 100 μm, more preferably 10 to 80 μm, and even more preferably 20 to 60 μm. If the thickness of the film is within this range, it will be easier to obtain suitable heat sealability, heat resistance, film processability, etc.
　また、各層の厚みは、特に制限されるものではないが、例えば、上記表面層（Ａ）の厚みとしては、１～４０μｍであることが好ましく、１～３０μｍであることがより好ましく、３～３０μｍであることがさらに好ましい。上記シール層（Ｄ）の厚みは１～３０μｍであることが好ましく、２～２０μｍであることがより好ましく、２．５～１０μｍであることがさらに好ましい。上記中間層（Ｃ）を設ける場合には、その厚みは１～３０μｍであることが好ましく、２～２０μｍであることがより好ましく、３～１０μｍであることがさらに好ましい。上記中間層（Ｂ）を設ける場合には、１～６０μｍであることが好ましく、２～５０μｍであることがより好ましく、３～４０μｍであることがさらに好ましい。 Further, the thickness of each layer is not particularly limited, but for example, the thickness of the surface layer (A) is preferably 1 to 40 μm, more preferably 1 to 30 μm, and 3 to 30 μm. More preferably, the thickness is 30 μm. The thickness of the sealing layer (D) is preferably 1 to 30 μm, more preferably 2 to 20 μm, and even more preferably 2.5 to 10 μm. When the intermediate layer (C) is provided, its thickness is preferably 1 to 30 μm, more preferably 2 to 20 μm, and even more preferably 3 to 10 μm. When the intermediate layer (B) is provided, the thickness is preferably 1 to 60 μm, more preferably 2 to 50 μm, and even more preferably 3 to 40 μm.
　なお、中間層（Ｂ）を複数層とする場合、例えば表面層（Ａ）／中間層（Ｂ１）／中間層（Ｂ２）／中間層（Ｃ）／シール層（Ｄ）等の構成とする場合には、中間層（Ｂ１）と中間層（Ｂ２）の総厚みが上記中間層（Ｂ）の好ましい厚み範囲であることが好ましい。 In addition, when the intermediate layer (B) is made of multiple layers, for example, when it has a structure of surface layer (A)/intermediate layer (B1)/intermediate layer (B2)/intermediate layer (C)/seal layer (D), etc. In this case, the total thickness of the intermediate layer (B1) and the intermediate layer (B2) is preferably within the preferable thickness range of the intermediate layer (B).
　本発明の多層フィルムは、内容物保護の観点から、厚さ１２μｍの二軸延伸ポリエステルフィルムとラミネートした構成で、本発明のシーラントフィルムを厚さ１００μｍの二軸延伸ポリエステルフィルムに、シール幅１ｃｍで、２００℃、０．２ＭＰａ、１秒の条件でヒートシールした試験片を、１８０°方向に３００ｍｍ／分の速度で剥離したときのシール強度の最大値が、５～２０Ｎ／１５ｍｍであることが好ましく、６～１５Ｎ／１５ｍｍであることが好ましい。
　なお、シール方法については特に限定されず、超音波シール等の方法を用いてもよいが、ヒートシールが特に好ましい。 In order to protect the contents, the multilayer film of the present invention has a structure in which a 12 μm thick biaxially stretched polyester film is laminated with the sealant film of the present invention on a 100 μm thick biaxially stretched polyester film with a sealing width of 1 cm. When a test piece heat-sealed under the conditions of , 200°C, 0.2 MPa, and 1 second is peeled at a speed of 300 mm/min in a 180° direction, the maximum seal strength is 5 to 20 N/15 mm. Preferably, it is 6 to 15 N/15 mm.
Note that the sealing method is not particularly limited, and methods such as ultrasonic sealing may be used, but heat sealing is particularly preferred.
　本発明の多層フィルムの製造方法としては、特に限定されないが、例えば、表面層（Ａ）、シール層（Ｄ）に用いる各樹脂又は樹脂混合物を、中間層（Ｃ）を設ける場合には、さらに中間層（Ｃ）に用いる樹脂又は樹脂混合物を、中間層（Ｂ）を設ける場合には、さらに中間層（Ｂ）に用いる樹脂又は樹脂混合物を、それぞれ別々の押出機で加熱溶融させ、共押出多層ダイス法やフィードブロック法等の方法により溶融状態で（Ａ）／（Ｄ）の順や、（Ａ）／（Ｃ）／（Ｄ）の順や、（Ａ）／（Ｂ）／（Ｃ）／（Ｄ）の順等で積層した後、インフレーションやＴダイ・チルロール法等によりフィルム状に成形する共押出法が挙げられる。この共押出法は、各層の厚さの比率を比較的自由に調整することが可能で、衛生性に優れ、コストパフォーマンスにも優れた多層フィルムが得られるので好ましい。 Although the method for producing the multilayer film of the present invention is not particularly limited, for example, each resin or resin mixture used for the surface layer (A) and the sealing layer (D) may be further added when providing the intermediate layer (C). When forming an intermediate layer (B), the resin or resin mixture used for the intermediate layer (C) is further heated and melted in separate extruders to coextrude the resin or resin mixture used for the intermediate layer (B). The order of (A)/(D), the order of (A)/(C)/(D), or the order of (A)/(B)/(C) in a molten state by methods such as the multilayer die method or the feed block method. )/(D), etc., and then formed into a film by inflation, T-die chill roll method, etc. A coextrusion method may be mentioned. This coextrusion method is preferable because it allows the ratio of the thickness of each layer to be adjusted relatively freely, and a multilayer film with excellent hygiene and cost performance can be obtained.
　本発明の多層フィルムは、上記の製造方法によって、実質的に無延伸の多層フィルムとして得られるため、真空成形による深絞り成形等の二次成形も可能となる。 Since the multilayer film of the present invention is obtained as a substantially unstretched multilayer film by the above-described manufacturing method, secondary forming such as deep drawing by vacuum forming is also possible.
　さらに、印刷インキとの接着性や、ラミネート用シーラントフィルムとして使用する場合のラミネート適性を向上させるため、前記表面層（Ａ）に表面処理を施すことが好ましい。このような表面処理としては、例えば、コロナ処理、プラズマ処理、クロム酸処理、火炎処理、熱風処理、オゾン・紫外線処理等の表面酸化処理、あるいはサンドブラスト等の表面凹凸処理を挙げることができるが、好ましくはコロナ処理である。 Further, in order to improve adhesion with printing ink and suitability for lamination when used as a sealant film for lamination, it is preferable to subject the surface layer (A) to a surface treatment. Examples of such surface treatments include surface oxidation treatments such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, ozone/ultraviolet treatment, and surface roughening treatments such as sandblasting. Corona treatment is preferred.
　（ラミネートフィルム）
　本発明の多層フィルムは、その他の基材をラミネ－トして使用することもできる。当該その他の基材は、表面層（Ａ）側にラミネートすることが好ましい。当該その他の基材は特に限定されず、普通紙、コート紙といった紙基材や、未延伸フィルム及び延伸フィルムといったプラスチックフィルムでもよいし、不織布等であってもよいが、モノマテリアル化によりリサイクル性を向上させるため、ポリエステル系樹脂フィルムであることが好ましい。 (Laminate film)
The multilayer film of the present invention can also be used by laminating other substrates. The other base material is preferably laminated on the surface layer (A) side. The other base material is not particularly limited, and may be a paper base material such as plain paper or coated paper, a plastic film such as unstretched film or stretched film, or a nonwoven fabric, but recyclability is improved by making it a monomaterial. In order to improve this, a polyester resin film is preferable.
　ラミネート方法としては公知の方法を実施でき、接着剤を用いたドライラミネートや、押出ラミネート等が挙げられる。当該ラミネートに用いる接着剤としては、公知の接着剤を使用することができるが、ポリオール組成物とポリイソシアネート組成物との２液硬化型接着剤であることが好ましい。２液硬化型接着剤は、溶剤型又は無溶剤型のいずれの形態であってもよい。
　また、当該接着剤の乾燥後の質量は、０．１～１０ｇ／ｍ２であることが好ましく、１～６ｇ／ｍ２であることがより好ましく、２～５ｇ／ｍ２であることがさらに好ましいが、モノマテリアル化のため、接着剤は少ない方がより好ましい。 As the laminating method, known methods can be used, including dry lamination using an adhesive, extrusion lamination, and the like. As the adhesive used for the laminate, any known adhesive can be used, but a two-component curing adhesive of a polyol composition and a polyisocyanate composition is preferred. The two-component curing adhesive may be in either a solvent type or a solvent-free type.
Further, the mass of the adhesive after drying is preferably 0.1 to 10 g/m 2 , more preferably 1 to 6 g/m 2 , and even more preferably 2 to 5 g/m 2 Although it is preferable, since it is a monomaterial, it is more preferable to use less adhesive.
　［蓋材］
　本発明の多層フィルムは、そのまま蓋材として使用してもよいが、表面層（Ａ）上に基材フィルムをラミネートした積層体からなる蓋材とすることも好ましい。基材フィルムとしては、シール性やデッドホールド性を損なわないものであれば特に制限はないが、例えば、二軸延伸ポリエステル（ＰＥＴ）、易裂け性二軸延伸ポリエステル（ＰＥＴ）、二軸延伸ポリプロピレン（ＯＰＰ）、エチレンビニルアルコール共重合体（ＥＶＯＨ）を中心層とした共押出二軸延伸ポリプロピレン、二軸延伸エチレンビニルアルコール共重合体（ＥＶＯＨ）、ポリ塩化ビニリデン（ＰＶＤＣ）をコートした共押出二軸延伸ポリプロピレン、二軸延伸ナイロン等が挙げられる。これら基材フィルムの中の１種類又は２種類以上を併用しても構わないが、モノマテリアル化の観点から、ラミネートするフィルムは二軸延伸ポリエステル（ＰＥＴ）及び易裂け性二軸延伸ポリエステル（ＰＥＴ）等のポリエステル系樹脂であることが好ましい。接着方法としては、ドライラミネーション、ウェットラミネーション、ノンソルベントラミネーション、押出ラミネーション等の方法が挙げられる。 [Lid material]
The multilayer film of the present invention may be used as a lid material as it is, but it is also preferable to use a lid material made of a laminate in which a base film is laminated on the surface layer (A). The base film is not particularly limited as long as it does not impair sealing properties or dead-hold properties, but examples include biaxially oriented polyester (PET), easily tearable biaxially oriented polyester (PET), and biaxially oriented polypropylene. (OPP), coextruded biaxially oriented polypropylene with ethylene vinyl alcohol copolymer (EVOH) as the center layer, coextruded biaxially oriented polypropylene coated with biaxially oriented ethylene vinyl alcohol copolymer (EVOH), and polyvinylidene chloride (PVDC). Examples include axially oriented polypropylene and biaxially oriented nylon. One type or two or more of these base films may be used in combination, but from the viewpoint of monomaterialization, the laminated film should be biaxially oriented polyester (PET) or easily tearable biaxially oriented polyester (PET). ) is preferably a polyester resin. Examples of the bonding method include methods such as dry lamination, wet lamination, non-solvent lamination, and extrusion lamination.
　前記ドライラミネーションで用いる接着剤としては、例えば、ポリエーテル－ポリウレ
　タン系接着剤、ポリエステル－ポリウレタン系接着剤等が挙げられる。 Examples of the adhesive used in the dry lamination include polyether-polyurethane adhesives, polyester-polyurethane adhesives, and the like.
　本発明の蓋材は、開口部を有する容器を、シールにより密着させて密閉するための蓋材として使用するものであるが、この開口部を有する容器として、その最表面層の素材（蓋材をヒートシールする部分）がポリエステル樹脂である容器に好ましく適用できる。特に、ヒートシール部が結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）を主成分とする容器に対しても好適なシール性や耐熱性を実現できることから、結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）容器用の蓋材としても好ましく使用できる。また、紙層とポリエチレンテレフタレート（ＰＥＴ）樹脂層とからなる紙ＰＥＴ容器用の蓋材としても好ましく使用できる。 The lid material of the present invention is used as a lid material for tightly sealing a container having an opening with a seal. It can be preferably applied to containers in which the heat-sealed portion) is made of polyester resin. In particular, since the heat-sealing part can achieve suitable sealing performance and heat resistance even for containers whose main component is crystallized polyethylene terephthalate (C-PET), lids for crystallized polyethylene terephthalate (C-PET) containers can be used. It can also be preferably used as a material. It can also be preferably used as a lid material for a paper PET container consisting of a paper layer and a polyethylene terephthalate (PET) resin layer.
　[包装材]
　本発明の多層フィルムからなる包装材としては、食品、薬品、工業部品、雑貨、雑誌等の用途に用いる包装袋、包装容器等が挙げられる。
　当該包装袋は、本発明の多層フィルムのシール層同士を重ねてシール、あるいは最外層とシール層とを重ね合わせてシールすることにより形成した包装袋であることが好ましい。また、当該包装袋は、本発明の多層フィルムを用いたラミネートフィルムにより作成することも可能である。
　当該包装袋としては、例えば当該多層フィルム２枚を所望とする包装袋の大きさに切り出して、それらを重ねて３辺をシールして袋状にした後、シールをしていない１辺から内容物を充填しシールして密封することで包装袋として用いることができる。さらには自動包装機によりロール状のフィルムを円筒形に端部をシールした後、上下をシールすることにより包装袋を形成することも可能である。 [Packaging material]
Examples of the packaging material made of the multilayer film of the present invention include packaging bags and packaging containers used for foods, medicines, industrial parts, miscellaneous goods, magazines, and the like.
The packaging bag is preferably a packaging bag formed by stacking and sealing the sealing layers of the multilayer film of the present invention, or by stacking and sealing the outermost layer and the sealing layer. Further, the packaging bag can also be made from a laminate film using the multilayer film of the present invention.
For the packaging bag, for example, two sheets of the multilayer film are cut to the desired size, stacked on top of each other and sealed on three sides to form a bag, and then the contents are inserted from the unsealed side. It can be used as a packaging bag by filling it with something and sealing it. Furthermore, it is also possible to form a packaging bag by sealing the ends of a roll of film into a cylindrical shape using an automatic packaging machine and then sealing the top and bottom.
　また、本発明の多層フィルムは、当該多層フィルムのシール層（Ｄ）とシール可能な別のフィルムを重ねてシールすることにより包装袋・容器を形成することも可能である。その際、当該別のフィルムとしては、比較的機械強度の弱いＬＤＰＥ、ＥＶＡ等のフィルムを用いることができる。また、ＬＤＰＥ、ＥＶＡ等のフィルムと、比較的引き裂き性の良い延伸フィルム、例えば、二軸延伸ポリエチレンテレフタレートフィルム（ＯＰＥＴ）、二軸延伸ポリプロピレンフィルム（ＯＰＰ）等とを貼り合わせたラミネートフィルムも用いることができる。中でも、モノマテリアル化の観点から、当該別のフィルムがポリエステル系フィルムからなるフィルムであることが好ましい。 Furthermore, the multilayer film of the present invention can also be used to form a packaging bag/container by overlapping and sealing the seal layer (D) of the multilayer film with another sealable film. In this case, as the other film, a film such as LDPE or EVA, which has relatively low mechanical strength, can be used. In addition, a laminate film made by laminating a film such as LDPE or EVA with a stretched film with relatively good tearability, such as biaxially stretched polyethylene terephthalate film (OPET), biaxially stretched polypropylene film (OPP), etc., may also be used. Can be done. Among these, from the viewpoint of monomaterialization, it is preferable that the other film is a polyester film.
　本発明の多層フィルムを用いた包装材には、初期の引き裂き強度を弱め、開封性を向上するため、シール部にＶノッチ、Ｉノッチ、ミシン目、微多孔等の任意の引き裂き開始部を形成することが好ましい。 In the packaging material using the multilayer film of the present invention, arbitrary tear initiation parts such as V notches, I notches, perforations, micropores, etc. are formed in the sealing part in order to weaken the initial tear strength and improve the ease of opening. It is preferable to do so.
　次に、実施例及び比較例を挙げて本発明をより詳しく説明する。以下、特に断りのない限り、「部」及び「％」は質量基準である。 Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Hereinafter, unless otherwise specified, "parts" and "%" are based on mass.
　（実施例１）
　表面層（Ａ）及びシール層（Ｄ）の各層を形成する樹脂成分として、各々下記の樹脂を使用して、各層を形成する樹脂、樹脂混合物を調整した。これら樹脂、樹脂混合物を押出機に供給して溶融し、溶融した樹脂を、フィードブロックを有するＴダイ・チルロール法の共押出多層フィルム製造装置に供給し、共溶融押出により、フィルムの層構成が、表面層（Ａ）／シール層（Ｄ）の２層構成で、各層の厚み比率が８０％／２０％、総厚みが３０μｍの多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）（融点１６５℃、ガラス転移温度－３２℃）１０部、非晶性ポリエステル（２）（ａ２）（ガラス転移温度７２℃）８０部、プロピレンブロック共重合体（２）（ａ３）（メルトフローレート（以下、ＭＦＲ）（２３０℃、２１．１８Ｎ）２．３ｇ／１０分、密度０．９ｇ／ｃｍ３、融点１６７℃、フィルム成膜時の曇り度７０％）１０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）８０部、非晶性ポリエステル（２）（ｄ２）１０部、プロピレンブロック共重合体（２）（ｄ３）１０部 (Example 1)
The following resins were used as resin components for forming each layer of the surface layer (A) and the seal layer (D), and resins and resin mixtures for forming each layer were prepared. These resins and resin mixtures are supplied to an extruder and melted, and the molten resin is supplied to a coextrusion multilayer film manufacturing apparatus using a T-die chill roll method having a feed block, and the layer structure of the film is changed by co-melt extrusion. A multilayer film with a two-layer structure of surface layer (A)/sealing layer (D), a thickness ratio of each layer of 80%/20%, and a total thickness of 30 μm was obtained.
Surface layer (A): 10 parts of crystalline polyester (3) (a1) (melting point 165°C, glass transition temperature -32°C), 80 parts of amorphous polyester (2) (a2) (glass transition temperature 72°C), Propylene block copolymer (2) (a3) (melt flow rate (hereinafter referred to as MFR) (230°C, 21.18N) 2.3g/10 minutes, density 0.9g/cm 3 , melting point 167°C, film formation Sealing layer (D): 80 parts of crystalline polyester (3) (d1), 10 parts of amorphous polyester (2) (d2), propylene block copolymer (2) (d3) ) 10 copies
　（実施例２）
　表面層（Ａ）とシール層（Ｄ）に使用する樹脂を下記とした以外は実施例１と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）２０部、非晶性ポリエステル（２）（ａ２）８０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）９０部、プロピレンブロック共重合体（１）（ｄ３）（ＭＦＲ（２３０℃、２１．１８Ｎ）２．０ｇ／１０分、密度０．９ｇ／ｃｍ３、融点１６５℃、フィルム成膜時の曇り度５２％）１０部 (Example 2)
A multilayer film was obtained in the same manner as in Example 1, except that the resins used for the surface layer (A) and the seal layer (D) were as follows.
Surface layer (A): 20 parts of crystalline polyester (3) (a1), 80 parts of amorphous polyester (2) (a2) Seal layer (D): 90 parts of crystalline polyester (3) (d1), propylene block Copolymer (1) (d3) (MFR (230°C, 21.18N) 2.0g/10 min, density 0.9g/cm 3 , melting point 165°C, haze during film formation 52%) 10 parts
　（実施例３）
　表面層に使用する樹脂を下記とした以外は実施例２と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）４０部、非晶性ポリエステル（２）（ａ２）６０部 (Example 3)
A multilayer film was obtained in the same manner as in Example 2 except that the resin used for the surface layer was as follows.
Surface layer (A): 40 parts of crystalline polyester (3) (a1), 60 parts of amorphous polyester (2) (a2)
　（実施例４）
　表面層（Ａ）、中間層（Ｂ）、中間層（Ｃ）及びシール層（Ｄ）の各層を形成する樹脂成分として、各々下記の樹脂を使用して、各層を形成する樹脂、樹脂混合物を調整した。これら樹脂、樹脂混合物を押出機に供給して溶融し、溶融した樹脂を、フィードブロックを有するＴダイ・チルロール法の共押出多層フィルム製造装置に供給し、共溶融押出により、フィルムの層構成が、表面層（Ａ）／中間層（Ｂ）／中間層（Ｃ）／シール層（Ｄ）の４層構成で、各層の厚み比率が２０％／５０％／１０％／２０％、総厚みが３０μｍの多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）１０部、非晶性ポリエステル（２）（ａ２）８０部、プロピレンブロック共重合体（１）（ａ３）１０部
　中間層（Ｂ）：結晶性ポリエステル（３）（ｂ１）１０部、非晶性ポリエステル（２）（ｂ２）９０部
　中間層（Ｃ）：結晶性ポリエステル（３）（ｃ１）１０部、非晶性ポリエステル（２）（ｃ２）９０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）９０部、非晶性ポリエステル（２）（ｄ２）１０部 (Example 4)
The following resins were used as resin components to form each layer of the surface layer (A), middle layer (B), middle layer (C), and sealing layer (D), and the resins and resin mixtures forming each layer were It was adjusted. These resins and resin mixtures are supplied to an extruder and melted, and the molten resin is supplied to a coextrusion multilayer film manufacturing apparatus using a T-die chill roll method having a feed block, and the layer structure of the film is changed by co-melt extrusion. , has a four-layer configuration of surface layer (A)/intermediate layer (B)/intermediate layer (C)/seal layer (D), the thickness ratio of each layer is 20%/50%/10%/20%, and the total thickness is A 30 μm multilayer film was obtained.
Surface layer (A): 10 parts of crystalline polyester (3) (a1), 80 parts of amorphous polyester (2) (a2), 10 parts of propylene block copolymer (1) (a3) Intermediate layer (B): Crystalline polyester (3) (b1) 10 parts, amorphous polyester (2) (b2) 90 parts Intermediate layer (C): crystalline polyester (3) (c1) 10 parts, amorphous polyester (2) ( c2) 90 parts Seal layer (D): 90 parts of crystalline polyester (3) (d1), 10 parts of amorphous polyester (2) (d2)
　（実施例５）　　　　
　シール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）８０部、非晶性ポリエステル（２）（ｄ２）１０部、プロピレンブロック共重合体（１）（ｄ３）１０部 (Example 5)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
Seal layer (D): 80 parts of crystalline polyester (3) (d1), 10 parts of amorphous polyester (2) (d2), 10 parts of propylene block copolymer (1) (d3)
　（実施例６）
　シール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）９５部、プロピレンブロック共重合体（１）（ｄ３）５部 (Example 6)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
Seal layer (D): 95 parts of crystalline polyester (3) (d1), 5 parts of propylene block copolymer (1) (d3)
　（実施例７）
　シール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）９０部、プロピレンブロック共重合体（１）（ｄ３）１０部 (Example 7)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
Seal layer (D): 90 parts of crystalline polyester (3) (d1), 10 parts of propylene block copolymer (1) (d3)
　（実施例８）
　シール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）８０部、プロピレンブロック共重合体（１）（ｄ３）２０部 (Example 8)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
Seal layer (D): 80 parts of crystalline polyester (3) (d1), 20 parts of propylene block copolymer (1) (d3)
　（実施例９）
　シール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）７０部、非晶性ポリエステル（２）（ｄ２）１０部、プロピレンブロック共重合体（１）（ｄ３）２０部 (Example 9)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
Seal layer (D): 70 parts of crystalline polyester (3) (d1), 10 parts of amorphous polyester (2) (d2), 20 parts of propylene block copolymer (1) (d3)
　（実施例１０）
　シール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）７５部、非晶性ポリエステル（２）（ｄ２）１５部、プロピレンブロック共重合体（１）（ｄ３）１０部 (Example 10)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the sealing layer (D) were as follows.
Seal layer (D): 75 parts of crystalline polyester (3) (d1), 15 parts of amorphous polyester (2) (d2), 10 parts of propylene block copolymer (1) (d3)
　（実施例１１）
　表面層（Ａ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）１０部、非晶性ポリエステル（２）（ａ２）８０部、プロピレンブロック共重合体（２）（ａ３）１０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）７５部、非晶性ポリエステル（２）（ｄ２）１５部、プロピレンブロック共重合体（２）（ｄ３）１０部 (Example 11)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A) and the seal layer (D) were as follows.
Surface layer (A): 10 parts of crystalline polyester (3) (a1), 80 parts of amorphous polyester (2) (a2), 10 parts of propylene block copolymer (2) (a3) Sealing layer (D): 75 parts of crystalline polyester (3) (d1), 15 parts of amorphous polyester (2) (d2), 10 parts of propylene block copolymer (2) (d3)
　（実施例１２）
　中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　中間層（Ｃ）：結晶性ポリエステル（３）（ｃ１）１００部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）１０部、非晶性ポリエステル（２）（ｄ２）９０部 (Example 12)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the intermediate layer (C) and the seal layer (D) were as follows.
Intermediate layer (C): 100 parts of crystalline polyester (3) (c1) Seal layer (D): 10 parts of crystalline polyester (3) (d1), 90 parts of amorphous polyester (2) (d2)
　（実施例１３）
　中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　中間層（Ｃ）：結晶性ポリエステル（３）（ｃ１）１００部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）５０部、非晶性ポリエステル（２）（ｄ２）５０部 (Example 13)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the intermediate layer (C) and the seal layer (D) were as follows.
Intermediate layer (C): 100 parts of crystalline polyester (3) (c1) Seal layer (D): 50 parts of crystalline polyester (3) (d1), 50 parts of amorphous polyester (2) (d2)
　（実施例１４）
　表面層（Ａ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）１０部、非晶性ポリエステル（２）（ａ２）８０部、プロピレンブロック共重合体（２）（ａ３）１０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｃ１）８０部、非晶性ポリエステル（２）（ｄ２）１０部、プロピレンブロック共重合体（２）（ｄ３）１０部 (Example 14)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A) and the seal layer (D) were as follows.
Surface layer (A): 10 parts of crystalline polyester (3) (a1), 80 parts of amorphous polyester (2) (a2), 10 parts of propylene block copolymer (2) (a3) Sealing layer (D): 80 parts of crystalline polyester (3) (c1), 10 parts of amorphous polyester (2) (d2), 10 parts of propylene block copolymer (2) (d3)
　（実施例１５）
　表面層（Ａ）、中間層（Ｂ）、中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）１０部、非晶性ポリエステル（１）（ａ２）（ガラス転移温度９０℃）８０部、プロピレンブロック共重合体（２）（ａ３）１０部
　中間層（Ｂ）：結晶性ポリエステル（３）（ｂ１）１０部、非晶性ポリエステル（１）（ｂ２）９０部
　中間層（Ｃ）：結晶性ポリエステル（３）（ｃ１）１０部、非晶性ポリエステル（１）（ｃ２）９０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）８０部、非晶性ポリエステル（１）（ｄ２）１０部、プロピレンブロック共重合体（２）（ｄ３）１０部 (Example 15)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
Surface layer (A): 10 parts of crystalline polyester (3) (a1), 80 parts of amorphous polyester (1) (a2) (glass transition temperature 90°C), 10 parts of propylene block copolymer (2) (a3) Parts Intermediate layer (B): 10 parts of crystalline polyester (3) (b1), 90 parts of amorphous polyester (1) (b2) Intermediate layer (C): 10 parts of crystalline polyester (3) (c1), Crystalline polyester (1) (c2) 90 parts Seal layer (D): Crystalline polyester (3) (d1) 80 parts, amorphous polyester (1) (d2) 10 parts, propylene block copolymer (2) (d3) 10 copies
　（実施例１６）
　表面層（Ａ）、中間層（Ｂ）、中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（１）（ａ１）（融点１２６℃、ガラス転移温度－７０℃）１０部、非晶性ポリエステル（２）（ａ２）８０部、プロピレンブロック共重合体（２）（ａ３）１０部
　中間層（Ｂ）：結晶性ポリエステル（１）（ｂ１）１０部、非晶性ポリエステル（２）（ｂ２）９０部
　中間層（Ｃ）：結晶性ポリエステル（１）（ｃ１）１０部、非晶性ポリエステル（２）（ｃ２）９０部
　シール層（Ｄ）：結晶性ポリエステル（１）（ｄ１）８０部、非晶性ポリエステル（２）（ｄ２）１０部、プロピレンブロック共重合体（２）（ｄ３）１０部 (Example 16)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
Surface layer (A): 10 parts of crystalline polyester (1) (a1) (melting point 126°C, glass transition temperature -70°C), 80 parts of amorphous polyester (2) (a2), propylene block copolymer (2) ) (a3) 10 parts Intermediate layer (B): 10 parts of crystalline polyester (1) (b1), 90 parts of amorphous polyester (2) (b2) Intermediate layer (C): Crystalline polyester (1) (c1 ) 10 parts, amorphous polyester (2) (c2) 90 parts Seal layer (D): crystalline polyester (1) (d1) 80 parts, amorphous polyester (2) (d2) 10 parts, propylene block 10 parts of polymer (2) (d3)
　（実施例１７）
　表面層（Ａ）、中間層（Ｂ）、中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（２）（ａ１）（融点１２０℃、ガラス転移温度－３５℃）、非晶性ポリエステル（２）（ａ２）８０部、プロピレンブロック共重合体（２）（ａ３）１０部
　中間層（Ｂ）：結晶性ポリエステル（２）（ｂ１）１０部、非晶性ポリエステル（２）（ｂ２）９０部
　中間層（Ｃ）：結晶性ポリエステル（２）（ｃ１）１０部、非晶性ポリエステル（２）（ｃ２）９０部
　シール層（Ｄ）：結晶性ポリエステル（２）（ｄ１）８０部、非晶性ポリエステル（２）（ｄ２）１０部、プロピレンブロック共重合体（２）（ｄ３）１０部 (Example 17)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
Surface layer (A): Crystalline polyester (2) (a1) (melting point 120°C, glass transition temperature -35°C), 80 parts of amorphous polyester (2) (a2), propylene block copolymer (2) ( a3) 10 parts Intermediate layer (B): 10 parts of crystalline polyester (2) (b1), 90 parts of amorphous polyester (2) (b2) Intermediate layer (C): 10 parts of crystalline polyester (2) (c1) parts, amorphous polyester (2) (c2) 90 parts Seal layer (D): crystalline polyester (2) (d1) 80 parts, amorphous polyester (2) (d2) 10 parts, propylene block copolymer (2) (d3) 10 copies
　（比較例１）
　表面層（Ａ）、中間層（Ｂ）、中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（３）（ａ１）１０部、非晶性ポリエステル（２）（ａ２）９０部
　中間層（Ｂ）：結晶性ポリエステル（３）（ｂ１）１０部、非晶性ポリエステル（２）（ｂ２）９０部
　中間層（Ｃ）：結晶性ポリエステル（３）（ｃ１）１０部、非晶性ポリエステル（２）（ｃ２）９０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）９０部、非晶性ポリエステル（２）（ｄ２）１０部 (Comparative example 1)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and sealing layer (D) were as follows.
Surface layer (A): 10 parts of crystalline polyester (3) (a1), 90 parts of amorphous polyester (2) (a2) Intermediate layer (B): 10 parts of crystalline polyester (3) (b1), amorphous Polyester (2) (b2) 90 parts Intermediate layer (C): Crystalline polyester (3) (c1) 10 parts, amorphous polyester (2) (c2) 90 parts Seal layer (D): Crystalline polyester ( 3) (d1) 90 parts, amorphous polyester (2) (d2) 10 parts
　（比較例２）
　表面層（Ａ）、中間層（Ｂ）、中間層（Ｃ）及びシール層（Ｄ）に使用する樹脂成分を下記とした以外は実施例４と同様にして多層フィルムを得た。
　表面層（Ａ）：結晶性ポリエステル（１）（ａ１）６０部、プロピレンブロック共重合体（１）（ａ３）４０部
　中間層（Ｂ）結晶性ポリエステル（１）（ｂ１）６０部、プロピレンブロック共重合体（１）（ｂ３）４０部
　中間層（Ｃ）：結晶性ポリエステル（１）（ｃ１）６０部、プロピレンブロック共重合体（１）（ｃ３）４０部
　シール層（Ｄ）：結晶性ポリエステル（３）（ｄ１）８０部、プロピレンブロック共重合体（１）（ｄ３）２０部 (Comparative example 2)
A multilayer film was obtained in the same manner as in Example 4, except that the resin components used for the surface layer (A), intermediate layer (B), intermediate layer (C), and seal layer (D) were as follows.
Surface layer (A): 60 parts of crystalline polyester (1) (a1), 40 parts of propylene block copolymer (1) (a3) Intermediate layer (B) 60 parts of crystalline polyester (1) (b1), propylene block Copolymer (1) (b3) 40 parts Intermediate layer (C): Crystalline polyester (1) (c1) 60 parts, Propylene block copolymer (1) (c3) 40 parts Seal layer (D): Crystalline 80 parts of polyester (3) (d1), 20 parts of propylene block copolymer (1) (d3)
　［フィルム加工性の評価］
　実施例及び比較例の多層フィルムについて、成膜時におけるフィルム加工性を以下の基準で評価した。
　〇：多層フィルムがニップロールを通過する際に当該ロールに貼り付くことなく成膜でき、巻き上がったフィルムにしわの発生もない。
　△：ニップロールを通過する際に若干当該ロールへの貼り付きが生じ、巻き上がったフィルムにしわが発生する。
　×：多層フィルムがニップロールを通過する際に当該ロールに貼り付いて、フィルムの巻き上げが困難。 [Evaluation of film processability]
Regarding the multilayer films of Examples and Comparative Examples, film processability during film formation was evaluated using the following criteria.
○: The multilayer film can be formed without sticking to the nip roll when it passes through the nip roll, and the rolled-up film does not have wrinkles.
Δ: When passing through the nip rolls, the film slightly sticks to the rolls and wrinkles occur in the rolled up film.
×: When the multilayer film passes through the nip roll, it sticks to the roll, making it difficult to wind up the film.
　［耐ブロッキング性の評価］
　巻き取ったフィルムの表面層（Ａ）とシール層（Ｄ）との貼り付き（ブロッキング）について、以下の基準で評価した。
　◎：貼り付かない
　〇：若干の貼り付きが生じるが、手で容易に剥がせる
　×：貼り付いて剥がせない） [Evaluation of blocking resistance]
The adhesion (blocking) between the surface layer (A) and the seal layer (D) of the wound film was evaluated based on the following criteria.
◎: Does not stick 〇: Slight sticking occurs, but can be easily removed by hand ×: Sticks and cannot be removed)
　［ヘイズの評価］
　実施例及び比較例の多層フィルムのヘイズについて、ＪＩＳ Ｋ ７１０５：１９８１に基づき、ヘーズメーター（日本電飾工業株式会社製）を用いて測定した。
　◎：２０％以下
　〇：２１～３０％
　△：３１～４９％
　×：５０％以上 [Haze evaluation]
The haze of the multilayer films of Examples and Comparative Examples was measured using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd.) based on JIS K 7105:1981.
◎: 20% or less ○: 21-30%
△: 31-49%
×: 50% or more
　［開封強度の評価］
　実施例及び比較例の多層フィルムと、厚みが１２μｍの二軸延伸ポリエステルフィルムとを、ドライラミネート接着剤を用いてそれぞれ貼り合わせ、４０℃で２４時間エージングした後、縦と横が１０ｃｍ×１０ｃｍになるよう切り出してラミネートフィルムを得た。前記で得られたラミネートフィルムと８８φの結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）丸型成形容器とを、前記ラミネートフィルムのシール層（Ｄ）側の面がカップフランジ側に来るように重ね合わせたのち、カップシーラー（株式会社シンワ機械製カップシーラー）を用いて、２２０℃に調節された上部ヒートシール金型で、約１００ｋｇ、１秒の条件でヒートシールした。得られたサンプルをヒートシールされたフランジ部分の外側フィルム部分をプッシュプルゲージ先端で掴み、フランジ水平面から４５度の角度で蓋材を引き剥がしたときの最大強度を開封強度とした。
　◎：１５Ｎ以下
　○：１５～２０Ｎ
　×：２０Ｎ超 [Evaluation of opening strength]
The multilayer films of Examples and Comparative Examples and a biaxially stretched polyester film with a thickness of 12 μm were laminated together using a dry laminating adhesive, and after aging at 40° C. for 24 hours, the length and width were 10 cm x 10 cm. A laminated film was obtained by cutting out the film. The laminate film obtained above and an 88φ crystallized polyethylene terephthalate (C-PET) round molded container were stacked together so that the sealing layer (D) side of the laminate film was on the cup flange side. Using a cup sealer (Cup Sealer manufactured by Shinwa Kikai Co., Ltd.), heat sealing was performed using an upper heat sealing mold adjusted to 220° C. under conditions of approximately 100 kg and 1 second. The outer film portion of the heat-sealed flange portion of the obtained sample was grasped with the tip of the push-pull gauge, and the maximum strength when the lid material was peeled off at an angle of 45 degrees from the horizontal surface of the flange was defined as the unsealing strength.
◎: 15N or less ○: 15-20N
×: More than 20N
　［シール強度の評価］
　実施例及び比較例の多層フィルムと、厚みが１２μｍの二軸延伸ポリエステルフィルムとを、ドライラミネート接着剤を用いてそれぞれ貼り合わせ、４０℃で２４時間エージングした後、縦と横が１０ｃｍ×１０ｃｍになるよう切り出してラミネートフィルムを得た。前記で得られたラミネートフィルムと８８φの結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）丸型成形容器とを、前記ラミネートフィルムのシール層（Ｄ）側の面がカップフランジ側に来るように重ね合わせたのち、カップシーラー（シンワ機械製カップシーラー）を用いて、２２０℃に調節された上部ヒートシール金型で、約１００ｋｇ、１秒の条件でヒートシールした。得られたサンプルをヒートシールされたフランジ部分の内側フィルム部分を１５ｍｍ幅で切り出して、プッシュプルゲージ先端で掴み、フランジ水平面から９０度の角度で蓋材を引き剥がしたときの最大強度をシール強度とした。以下の基準で評価した。
　◎：１０Ｎ／１５ｍｍ以上
　○：７～９Ｎ／１５ｍｍ
　×：７Ｎ／１５ｍｍ未満 [Evaluation of seal strength]
The multilayer films of Examples and Comparative Examples and a biaxially stretched polyester film with a thickness of 12 μm were laminated together using a dry laminating adhesive, and after aging at 40° C. for 24 hours, the length and width were 10 cm x 10 cm. A laminated film was obtained by cutting out the film. The laminate film obtained above and an 88φ crystallized polyethylene terephthalate (C-PET) round molded container were stacked together so that the sealing layer (D) side of the laminate film was on the cup flange side. Using a cup sealer (cup sealer manufactured by Shinwa Kikai Co., Ltd.), heat sealing was performed using an upper heat sealing mold adjusted to 220° C. under conditions of approximately 100 kg and 1 second. Seal strength is the maximum strength when the inner film part of the heat-sealed flange part of the obtained sample is cut out to a width of 15 mm, grasped with the tip of the push-pull gauge, and the lid material is peeled off at an angle of 90 degrees from the horizontal plane of the flange. And so. Evaluation was made based on the following criteria.
◎: 10N/15mm or more ○: 7-9N/15mm
×: Less than 7N/15mm
　［剥離外観の評価］
　上記開封強度測定に使用した試験片において、剥離後の被着体外観を目視で観察し、以下の基準で評価した。
　○：結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）被着体の剥離部に樹脂残りや膜残りがなかった
　△：結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）被着体の剥離部の一部に多層フィルムの凝集破壊による樹脂残りや膜残りが確認された。
　×：結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）被着体の剥離部の全箇所において多層フィルムの凝集破壊による樹脂残りや膜残りが確認された [Evaluation of peeling appearance]
In the test piece used for the above-mentioned opening strength measurement, the appearance of the adherend after peeling was visually observed and evaluated according to the following criteria.
○: There was no resin or film residue on the peeled part of the crystallized polyethylene terephthalate (C-PET) adherend. △: There was no multilayer film residue on the peeled part of the crystallized polyethylene terephthalate (C-PET) adherend. Resin and film residues due to cohesive failure were confirmed.
×: Resin residue and film residue due to cohesive failure of the multilayer film were confirmed at all locations of the peeled part of the crystallized polyethylene terephthalate (C-PET) adherend.
Figure JPOXMLDOC01-appb-T000001
　
Figure JPOXMLDOC01-appb-T000001
　
Figure JPOXMLDOC01-appb-T000002
　
Figure JPOXMLDOC01-appb-T000002
　
　上記表から明らかなとおり、実施例１～１７の本発明の多層フィルムは、好適なフィルム加工性、耐ブロッキング性を発揮することができ、透明性に優れ、良好な結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）に対する開封強度とシール強度を両立したものであった。また、膜残りせずに剥離後の外観が良好であった。
　特に、中間層を有する実施例４～１７の多層フィルムは、ポリオレフィン系樹脂の含有量を調節しやすいため、透明性とその他の特性を好適に維持しやすかった。さらに、結晶性ポリエステル（ｃ１）と結晶性ポリエステル（ｄ１）の合計質量比率と、非晶性ポリエステル（ｃ２）と非晶性ポリエステルｄ２の合計質量比率の差が小さい実施例４～１２及び実施例１４～１５の多層フィルムは、易剥離性とシール強度と剥離外観を両立しやすかった。
　一方、比較例１～２の多層フィルムは、好適なフィルム加工性や易開封性、高いシール強度を兼備できないものであった。
　
　 As is clear from the above table, the multilayer films of the present invention of Examples 1 to 17 can exhibit suitable film processability and blocking resistance, have excellent transparency, and have good crystallized polyethylene terephthalate (C- It achieved both opening strength and sealing strength against PET). Moreover, the appearance after peeling was good with no film remaining.
In particular, in the multilayer films of Examples 4 to 17 having an intermediate layer, it was easy to adjust the content of the polyolefin resin, so it was easy to maintain transparency and other properties suitably. Further, Examples 4 to 12 and Examples in which the difference between the total mass ratio of crystalline polyester (c1) and crystalline polyester (d1) and the total mass ratio of amorphous polyester (c2) and amorphous polyester d2 are small The multilayer films of Nos. 14 and 15 were easy to achieve both easy peelability, seal strength, and peel appearance.
On the other hand, the multilayer films of Comparative Examples 1 and 2 were unable to have suitable film processability, easy opening, and high seal strength.

Claims (7)

  1. 　シール層（Ｄ）と、表面層（Ａ）とを有する多層フィルムであって、
    　前記多層フィルムを構成する樹脂全体に対するポリエステル系樹脂の質量比率が、７０質量％以上であり、
    　前記多層フィルムを構成する樹脂全体に対する結晶性ポリエステル系樹脂の質量比率が１０質量％以上であり、
    　前記多層フィルムを構成する樹脂全体に対する非晶性ポリエステル系樹脂の質量比率が２０質量％以上であり、
    　前記多層フィルムを構成する樹脂全体に対するポリオレフィン系樹脂の質量比率が１質量％以上である
    　ことを特徴とする多層フィルム。     A multilayer film having a sealing layer (D) and a surface layer (A),
    The mass ratio of the polyester resin to the entire resin constituting the multilayer film is 70% by mass or more,
    The mass ratio of the crystalline polyester resin to the entire resin constituting the multilayer film is 10% by mass or more,
    The mass ratio of the amorphous polyester resin to the entire resin constituting the multilayer film is 20% by mass or more,
    A multilayer film characterized in that the mass ratio of the polyolefin resin to the entire resin constituting the multilayer film is 1% by mass or more.
  2. 　前記表面層（Ａ）が、結晶性ポリエステル（ａ１）、非晶性ポリエステル（ａ２）及びポリオレフィン系樹脂（ａ３）を含有する、請求項１に記載の多層フィルム。 The multilayer film according to claim 1, wherein the surface layer (A) contains a crystalline polyester (a1), an amorphous polyester (a2), and a polyolefin resin (a3).
  3. 　前記多層フィルムが、さらに中間層（Ｃ）を有する、請求項２に記載の多層フィルム。 The multilayer film according to claim 2, wherein the multilayer film further has an intermediate layer (C).
  4. 　前記中間層（Ｃ）が、前記シール層（Ｄ）と直接積層され、
    　前記中間層（Ｃ）が、結晶性ポリエステル（ｃ１）及び／又は非晶性ポリエステル（ｃ２）を含有し、
    　前記シール層（Ｄ）が、結晶性ポリエステル（ｄ１）及び／又は非晶性ポリエステル（ｄ２）を含有し、
    　前記シール層（Ｄ）に含まれる樹脂成分中の前記結晶性ポリエステル（ｄ１）の質量比率と前記中間層（Ｃ）に含まれる樹脂成分中の結晶性ポリエステル（ｃ１）の質量比率の合計と、
    　前記シール層（Ｄ）に含まれる樹脂成分中の前記非晶性ポリエステル（ｄ２）の質量比率と前記中間層（Ｃ）に含まれる樹脂成分中の非晶性ポリエステル（ｃ２）の質量比率の合計との差が６０質量％以内である、
    請求項３に記載の多層フィルム。     The intermediate layer (C) is directly laminated with the seal layer (D),
    The intermediate layer (C) contains a crystalline polyester (c1) and/or an amorphous polyester (c2),
    The sealing layer (D) contains a crystalline polyester (d1) and/or an amorphous polyester (d2),
    The sum of the mass ratio of the crystalline polyester (d1) in the resin component contained in the seal layer (D) and the mass ratio of the crystalline polyester (c1) in the resin component contained in the intermediate layer (C),
    The sum of the mass ratio of the amorphous polyester (d2) in the resin component contained in the sealing layer (D) and the mass ratio of the amorphous polyester (c2) in the resin component contained in the intermediate layer (C). The difference is within 60% by mass,
    The multilayer film according to claim 3.
  5. 　前記シール層（Ｄ）が、ポリオレフィン系樹脂（ｄ３）を含み、
    　前記シール層（Ｄ）に含まれる樹脂成分中の前記ポリオレフィン系樹脂（ｄ３）の質量比率が１～１８質量％である、請求項１に記載の多層フィルム。     The sealing layer (D) contains a polyolefin resin (d3),
    The multilayer film according to claim 1, wherein the mass ratio of the polyolefin resin (d3) in the resin component contained in the sealing layer (D) is 1 to 18% by mass.
  6. 　請求項１～５に記載の多層フィルムからなる蓋材。 A lid material comprising the multilayer film according to claims 1 to 5.
  7. 　前記多層フィルムの前記シール層（Ｄ）とシールする被着体が結晶化ポリエチレンテレフタレート（Ｃ－ＰＥＴ）樹脂を含む開口部を有する容器である、包装材。 A packaging material, wherein the adherend to be sealed with the sealing layer (D) of the multilayer film is a container having an opening containing crystallized polyethylene terephthalate (C-PET) resin.
PCT/JP2023/025058 2022-07-19 2023-07-06 Multilayer film, cover material, and packaging material WO2024018903A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2023563852A JP7460036B1 (en) 2022-07-19 2023-07-06 Multilayer films, lids and packaging materials

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022114682 2022-07-19
JP2022-114682 2022-07-19

Publications (1)

Publication Number Publication Date
WO2024018903A1 true WO2024018903A1 (en) 2024-01-25

Family

ID=89617768

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/025058 WO2024018903A1 (en) 2022-07-19 2023-07-06 Multilayer film, cover material, and packaging material

Country Status (2)

Country Link
JP (1) JP7460036B1 (en)
WO (1) WO2024018903A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006257134A (en) * 2005-03-15 2006-09-28 Sumitomo Chemical Co Ltd Easily releasable film and lid material
JP2018167547A (en) * 2017-03-30 2018-11-01 住化プラステック株式会社 Easily-peelable film, lid material, and container
JP2021102301A (en) * 2019-12-25 2021-07-15 Dic株式会社 Laminate film and packaging material

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006257134A (en) * 2005-03-15 2006-09-28 Sumitomo Chemical Co Ltd Easily releasable film and lid material
JP2018167547A (en) * 2017-03-30 2018-11-01 住化プラステック株式会社 Easily-peelable film, lid material, and container
JP2021102301A (en) * 2019-12-25 2021-07-15 Dic株式会社 Laminate film and packaging material

Also Published As

Publication number Publication date
JP7460036B1 (en) 2024-04-02

Similar Documents

Publication Publication Date Title
TWI410448B (en) Polyester film
JP7280826B2 (en) Extrudable anti-fog copolyester heat seal resin
JP5833534B2 (en) Heat-sealable composite polyester film
JP5804339B2 (en) Anti-fogging multilayer film, laminate using the same, and packaging material
JP6993923B2 (en) Sealant film and packaging material
JP5182183B2 (en) Easy-open film, lid material and packaging bag using the film
JP6973687B2 (en) Laminated film and lid material
JP4655703B2 (en) Easy peelable film and lid
JP2000263727A (en) Laminated material and packaging container using the same
JP4839642B2 (en) Easy peelable film and lid
JP7460036B1 (en) Multilayer films, lids and packaging materials
JP7419802B2 (en) Laminated films and packaging materials
JP6973686B2 (en) Laminated film and lid material
JP2019151351A (en) Package
JP3914440B2 (en) Overwrap package
JP2008087181A (en) Easily openable laminated film, laminated film and lid material
TW202408807A (en) Multilayer films, covering materials and packaging materials
JP5380866B2 (en) LAMINATE, CLOSED CLOSED CONTAINING THE SAME, AND CLOSED CONTAINER
JP2003200969A (en) Pillow packing bag
JP2714866B2 (en) Polyester laminate
JP2667281B2 (en) Easy open materials
JP2008087180A (en) Easily openable laminated film, laminated film and lid material
JPH08318606A (en) Multilayer packaging material and vessel
WO2023248809A1 (en) Biodegradable security seal film, lid member, and packaging member
JPH06126916A (en) Polyester laminate

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23842828

Country of ref document: EP

Kind code of ref document: A1