WO2023181852A1 - Stratifié d'emballage et sac d'emballage - Google Patents

Stratifié d'emballage et sac d'emballage Download PDF

Info

Publication number
WO2023181852A1
WO2023181852A1 PCT/JP2023/008077 JP2023008077W WO2023181852A1 WO 2023181852 A1 WO2023181852 A1 WO 2023181852A1 JP 2023008077 W JP2023008077 W JP 2023008077W WO 2023181852 A1 WO2023181852 A1 WO 2023181852A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
shrinkage rate
less
laminate
heat shrinkage
Prior art date
Application number
PCT/JP2023/008077
Other languages
English (en)
Japanese (ja)
Inventor
悠 荻原
Original Assignee
凸版印刷株式会社
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 凸版印刷株式会社 filed Critical 凸版印刷株式会社
Publication of WO2023181852A1 publication Critical patent/WO2023181852A1/fr

Links

Images

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
    • 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
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • 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 disclosure relates to a packaging laminate and a packaging bag.
  • a laminate includes a biaxially oriented PET (polyethylene terephthalate) film with excellent heat resistance and toughness as a base film, and a polyolefin film such as polyethylene or polypropylene as a sealant layer (for example, see Patent Document 1) .
  • the outermost layer is the part that receives the most heat during the heat-sealing process during bag making, so a film that is difficult to heat-seal is used, but high temperatures are applied during the heat-sealing process to fuse the innermost layer, the sealant. Then, the outermost layer is deformed due to thermal contraction, causing problems such as distortion of the bag, deterioration of transportability, and deterioration of workability when sealing the contents.
  • the present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a packaging laminate that can reduce deformation during bag making even when the main component is polypropylene.
  • the present disclosure also aims to provide a packaging bag using the packaging laminate.
  • the present disclosure provides the following packaging laminate and packaging bag.
  • a laminate comprising at least a base layer, an intermediate layer, and a sealant layer, wherein the base layer, the intermediate layer, and the sealant layer all contain polypropylene, and the total amount of the laminate is 90% of the total amount of the laminate. At least % by mass is polypropylene, and the heat shrinkage rate of the laminate in the MD direction and TD direction as determined by the following formulas (1) and (2) after heating in an oven at 150°C for 15 minutes is 12. .0% or less, a packaging laminate.
  • MD direction heat shrinkage rate (%) (MD direction length before heating - MD direction length after heating) / MD direction length before heating ⁇ 100 ...
  • TD direction heat shrinkage rate (%) (TD direction length before heating - TD direction length after heating) / TD direction length before heating ⁇ 100 ...
  • the heat shrinkage rate of the base material layer in the MD direction and the TD direction determined by the above formulas (1) and (2) after heating in an oven at 150°C for 15 minutes is 10.0% or less.
  • the heat shrinkage rate of the base layer in the MD direction determined by the above formula (1) after heating in an oven at 160° C. for 15 minutes is 20.0% or less, and the above formula (2)
  • the heat shrinkage rate of the base layer in the MD direction determined by the above formula (1) after heating in an oven at 160° C. for 15 minutes is 10.0% or less, and the above formula (2)
  • the heat shrinkage rate of the laminate in the MD direction determined by the above formula (1) after heating in an oven at 160°C for 15 minutes is 15.0% or less, and the heat shrinkage rate is 15.0% or less as determined by the above formula (2).
  • the heat shrinkage rate of the laminate in the MD direction determined by the above formula (1) after heating in an oven at 160°C for 15 minutes is 10.0% or less, and the heat shrinkage rate is 10.0% or less according to the above formula (2).
  • Forming a gas barrier coating layer further comprising: the gas barrier coating layer containing at least one selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, and a hydrolyzate thereof.
  • a packaging laminate that can reduce deformation during bag manufacturing even when the main component is polypropylene. Moreover, according to the present disclosure, a packaging bag using the packaging laminate can be provided.
  • FIG. 1 is a schematic cross-sectional view showing a packaging laminate according to one embodiment.
  • FIG. 2 is a schematic diagram showing a method for measuring the thermal shrinkage rate during oven heating.
  • FIG. 1 is a schematic cross-sectional view showing a packaging laminate (hereinafter also simply referred to as a "laminate") according to an embodiment.
  • the laminate 100 shown in FIG. 1 includes a base layer 11, an intermediate layer 12, and a sealant layer 13 in this order.
  • the base material layer 11 and the intermediate layer 12, as well as the intermediate layer 12 and the sealant layer 13, may be bonded together with an adhesive layer S, respectively.
  • the base layer, intermediate layer, and sealant layer all contain polypropylene.
  • the base layer, intermediate layer and sealant layer may include polypropylene film.
  • the laminate may include an inorganic oxide layer, for example, from the viewpoint of improving gas barrier properties against water vapor and oxygen.
  • the inorganic oxide layer may be provided on at least one surface of the base layer or on at least one surface of the intermediate layer.
  • the laminate may include a gas barrier coating layer provided on the inorganic oxide layer.
  • the base material layer is a layer that serves as one of the supports and contains polypropylene.
  • the base layer may contain or consist of a polypropylene film.
  • the polypropylene film may be an acid-modified polypropylene film obtained by graft-modifying polypropylene using an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, or the like.
  • polypropylene resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene- ⁇ -olefin copolymer, etc. can be used.
  • additives such as flame retardants, slip agents, anti-blocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be added to the polypropylene film constituting the base layer.
  • the polypropylene film constituting the base layer may be a stretched film or a non-stretched film.
  • the polypropylene film is preferably a stretched film.
  • the stretching method is not particularly limited, and any method may be used as long as it can provide a dimensionally stable film, such as inflation stretching, uniaxial stretching, or biaxial stretching.
  • the thickness of the base layer is not particularly limited. Depending on the application, the thickness can be set to 6 to 200 ⁇ m, but from the viewpoint of reducing material to reduce environmental impact, and from the viewpoint of obtaining excellent heat resistance, impact resistance, and excellent gas barrier properties, It may be 9-50 ⁇ m, it may be 12-38 ⁇ m, it may be 18-30 ⁇ m.
  • the laminated surface of the base material layer may be subjected to various pretreatments such as corona treatment, plasma treatment, flame treatment, etc., as long as the barrier performance is not impaired, or a coating layer such as an easy-to-adhesion layer may be provided.
  • an adhesion layer may be provided on the surface of the base layer on which the inorganic oxide layer is laminated.
  • the adhesion layer is provided on the base material layer, and can obtain two effects: improving the adhesion performance between the base material layer and the inorganic oxide layer and improving the smoothness of the surface of the base material layer. In addition, by improving the smoothness, it becomes easier to form an inorganic oxide layer uniformly without defects, and it becomes easier to exhibit high barrier properties.
  • the adhesive layer can be formed using an anchor coating agent.
  • urethane resin is preferred.
  • the urethane resin include polyester polyurethane resin, polyether polyurethane resin, and acrylic polyurethane resin.
  • polyester polyurethane resin or acrylic polyurethane resin is preferable from the viewpoint of heat resistance and interlayer adhesive strength.
  • acrylic polyurethane resins are more preferable for packaging materials subjected to boil/retort treatment.
  • the thickness of the adhesive layer is not particularly limited, but is preferably in the range of 0.01 to 5 ⁇ m, more preferably in the range of 0.03 to 3 ⁇ m, and particularly in the range of 0.05 to 2 ⁇ m. preferable.
  • the thickness of the adhesion layer is at least the above lower limit, more sufficient interlayer adhesion strength is likely to be obtained, while when it is at most the above upper limit, desired gas barrier properties tend to be easily exhibited.
  • known coating methods can be used without particular restrictions, and examples include dipping methods; methods using sprays, coaters, printing machines, brushes, etc. It will be done.
  • the types of coaters and printing machines used in these methods and their coating methods include gravure coaters such as direct gravure method, reverse gravure method, kiss reverse gravure method, and offset gravure method, reverse roll coater, and microgravure. Examples include a coater, a chamber doctor coater, an air knife coater, a dip coater, a bar coater, a comma coater, and a die coater.
  • the coating amount of the adhesion layer is preferably 0.01 to 5 g/m 2 , and preferably 0.03 to 3 g/m 2 in mass per 1 m 2 after coating and drying the anchor coating agent. It is more preferable.
  • mass per 1 m 2 after coating and drying the anchor coating agent is above the above lower limit, film formation tends to be sufficient.On the other hand, when it is below the above upper limit, it is sufficiently easy to dry and the solvent is removed. It tends to be difficult to remain.
  • Methods for drying the adhesive layer are not particularly limited, but include natural drying, drying in an oven set at a predetermined temperature, a dryer attached to the coater, such as an arch dryer, a floating dryer, a drum dryer, A method using an infrared dryer or the like can be mentioned. Further, the drying conditions can be appropriately selected depending on the drying method. For example, in the case of drying in an oven, it is preferable to dry at a temperature of 60 to 100° C. for about 1 second to 2 minutes.
  • a polyvinyl alcohol resin can be used instead of the polyurethane resin described above.
  • the polyvinyl alcohol resin may be any resin having a vinyl alcohol unit formed by saponifying a vinyl ester unit, and examples thereof include polyvinyl alcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH).
  • vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, and vinyl versatate can be polymerized alone. , followed by saponified resins.
  • the PVA may be a copolymerized or post-modified modified PVA. Modified PVA can be obtained, for example, by copolymerizing a vinyl ester and an unsaturated monomer copolymerizable with the vinyl ester, followed by saponification.
  • Examples of unsaturated monomers copolymerizable with vinyl ester include olefins such as ethylene, propylene, isobutylene, ⁇ -octene, ⁇ -dodecene, and ⁇ -octadecene; 3-buten-1-ol, 4-pentyn-1-ol , 5-hexen-1-ol, etc.; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, undecylenic acid; acrylonitrile, methacrylonitrile, etc.
  • olefins such as ethylene, propylene, isobutylene, ⁇ -octene, ⁇ -dodecene, and ⁇ -octadecene
  • unsaturated acids such as acrylic acid
  • Nitriles such as diacetone acrylamide, acrylamide, and methacrylamide; olefin sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid; alkyl vinyl ethers, dimethylallyl vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinyl ethylene Vinyl compounds such as carbonate, 2,2-dialkyl-4-vinyl-1,3-dioquinrane, glycerin monoallyl ether, 3,4-diacetoxy-1-butene; vinylidene chloride, 1,4-diacetoxy-2-butene, Examples include vinylene carbonate.
  • the degree of polymerization of PVA is preferably 300 to 3,000. If the degree of polymerization is less than 300, the barrier properties tend to deteriorate, and if it exceeds 3000, the viscosity is too high and the coating suitability tends to deteriorate.
  • the degree of saponification of PVA is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. Moreover, the degree of saponification of PVA may be 100 mol% or less, or 99.9 mol% or less. The degree of polymerization and saponification of PVA can be measured according to the method described in JIS K 6726 (1994).
  • EVOH is generally a copolymer of ethylene and acid vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl pivalate, and vinyl versatate. Obtained by saponifying the union.
  • the degree of polymerization of EVOH is preferably 300 to 3,000. If the degree of polymerization is less than 300, the barrier properties tend to deteriorate, and if it exceeds 3000, the viscosity is too high and the coating suitability tends to deteriorate.
  • the degree of saponification of the vinyl ester component of EVOH is preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 99 mol% or more. Further, the degree of saponification of EVOH may be 100 mol% or less, or 99.9 mol% or less.
  • the degree of saponification of EVOH is determined by nuclear magnetic resonance (1H-NMR) measurement from the peak area of hydrogen atoms contained in the vinyl ester structure and the peak area of hydrogen atoms contained in the vinyl alcohol structure.
  • the ethylene unit content of EVOH is 10 mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more, and particularly preferably 25 mol% or more. Further, the ethylene unit content of EVOH is preferably 65 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less. When the ethylene unit content is 10 mol % or more, gas barrier properties or dimensional stability under high humidity can be maintained favorably. On the other hand, when the ethylene unit content is 65 mol% or less, gas barrier properties can be improved.
  • the ethylene unit content of EVOH can be determined by NMR method.
  • methods for forming the adhesive layer include coating using a polyvinyl alcohol resin solution, multilayer extrusion, and the like.
  • the laminate includes an inorganic oxide layer
  • examples of the inorganic oxide contained in the inorganic oxide layer include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide.
  • the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide.
  • the inorganic oxide layer is a layer using silicon oxide.
  • the O/Si ratio of the inorganic oxide layer is 1.7 or more.
  • the metal Si content is suppressed and good transparency is easily obtained.
  • the O/Si ratio is preferably 2.0 or less.
  • the crystallinity of SiO becomes high and the inorganic oxide layer can be prevented from becoming too hard, and good tensile resistance can be obtained. Thereby, it is possible to suppress the occurrence of cracks in the inorganic oxide layer when laminating the gas barrier coating layer.
  • the base layer or intermediate layer may shrink due to heat during boiling or retort processing, but if the O/Si ratio is 2.0 or less, the inorganic oxide layer will shrink. It is possible to easily follow this and suppress the deterioration of barrier properties. From the viewpoint of obtaining these effects more fully, the O/Si ratio of the inorganic oxide layer is preferably 1.75 or more and 1.9 or less, and more preferably 1.8 or more and 1.85 or less.
  • the O/Si ratio of the inorganic oxide layer can be determined by X-ray photoelectron spectroscopy (XPS).
  • XPS X-ray photoelectron spectroscopy
  • the measurement device is an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., product name: JPS-90MXV), the X-ray source is non-monochromatic MgK ⁇ (1253.6eV), and the X-ray source is 100W (10kV-10mA). ) can be measured using the X-ray output.
  • Relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p can be used for quantitative analysis to determine the O/Si ratio, respectively.
  • the thickness of the inorganic oxide layer is preferably 10 nm or more and 50 nm or less.
  • the film thickness is 10 nm or more, sufficient water vapor barrier properties can be obtained.
  • the film thickness is 50 nm or less, it is possible to suppress the occurrence of cracks due to deformation due to internal stress of the thin film, and to suppress a decrease in water vapor barrier properties. It should be noted that if the film thickness exceeds 50 nm, the cost tends to increase due to an increase in the amount of materials used, a longer film formation time, etc., which is not preferable from an economic point of view. From the same viewpoint as above, the thickness of the inorganic oxide layer is more preferably 20 nm or more and 40 nm or less.
  • the inorganic oxide layer can be formed, for example, by vacuum film formation.
  • a physical vapor deposition method or a chemical vapor deposition method can be used.
  • the physical vapor deposition method include, but are not limited to, a vacuum evaporation method, a sputtering method, an ion plating method, and the like.
  • the chemical vapor deposition method include, but are not limited to, a thermal CVD method, a plasma CVD method, a photo CVD method, and the like.
  • the above vacuum film formation methods include resistance heating vacuum evaporation method, EB (Electron Beam) heating vacuum evaporation method, induction heating vacuum evaporation method, sputtering method, reactive sputtering method, dual magnetron sputtering method, and plasma chemical vapor deposition method. (PECVD method) etc. are particularly preferably used. However, in terms of productivity, the vacuum deposition method is currently the best.
  • a heating means for the vacuum evaporation method it is preferable to use one of an electron beam heating method, a resistance heating method, and an induction heating method.
  • the laminate may include a gas barrier coating layer on the inorganic oxide layer.
  • the gas barrier coating layer is formed using a composition for forming a gas barrier coating layer containing at least one member selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, and a hydrolyzate thereof.
  • the layer may be formed by
  • the gas barrier coating layer is a coating layer having gas barrier properties, and is an aqueous solution containing at least one member selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, and a hydrolyzate thereof.
  • a composition for forming a gas barrier coating layer hereinafter also referred to as a coating agent
  • main ingredient is a water/alcohol mixed solution.
  • the coating agent preferably contains at least a silane coupling agent or a hydrolyzate thereof, and preferably contains a hydroxyl group-containing polymer compound, a metal alkoxide and It is more preferable to contain at least one selected from the group consisting of hydrolysates thereof, a silane coupling agent or a hydrolyzate thereof, and a hydroxyl group-containing polymer compound or a hydrolyzate thereof, a metal alkoxide or It is more preferable to contain a hydrolyzate thereof and a silane coupling agent or a hydrolyzate thereof.
  • the coating agent can be prepared by directly or pre-hydrolyzing a metal alkoxide and a silane coupling agent in a solution in which a water-soluble polymer containing a hydroxyl group is dissolved in an aqueous (water or water/alcohol mixed) solvent. It can be prepared by mixing those that have been subjected to a treatment such as oxidation.
  • hydroxyl group-containing polymer compound used in the coating agent examples include polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate.
  • PVA polyvinyl alcohol
  • the gas barrier coating layer is formed from a composition containing at least one member selected from the group consisting of metal alkoxides represented by the following general formula (I) and hydrolysates thereof. is preferred.
  • R 1 and R 2 are each independently a monovalent organic group having 1 to 8 carbon atoms, and are preferably an alkyl group such as a methyl group or an ethyl group.
  • M represents an n-valent metal atom such as Si, Ti, Al, and Zr.
  • m is an integer from 1 to n.
  • R 1 or R 2 may be the same or different.
  • metal alkoxide examples include tetraethoxysilane [Si(OC 2 H 5 ) 4 ], triisopropoxyaluminum [Al(O-2′-C 3 H 7 ) 3 ], and the like. Tetraethoxysilane and triisopropoxyaluminum are preferred because they are relatively stable in aqueous solvents after hydrolysis.
  • Examples of the silane coupling agent include compounds represented by the following general formula (II). Si(OR 11 ) p (R 12 ) 3-p R 13 ...(II)
  • R 11 represents an alkyl group such as a methyl group or an ethyl group
  • R 12 represents an alkyl group, an aralkyl group, an aryl group, an alkenyl group, an alkyl group substituted with an acryloxy group, or a methacryloxy group.
  • R 13 represents a monovalent organic functional group
  • p represents an integer of 1 to 3.
  • R 11 or R 12 may be the same or different.
  • the monovalent organic functional group represented by R13 is a monovalent organic functional group containing a glycidyloxy group, an epoxy group, a mercapto group, a hydroxyl group, an amino group, an alkyl group substituted with a halogen atom, or an isocyanate group. Examples include groups.
  • silane coupling agent examples include vinyltrimethoxysilane, ⁇ -chloropropylmethyldimethoxysilane, ⁇ -chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, ⁇ -methacryloxypropyltrimethoxysilane, ⁇ - Examples include silane coupling agents such as methacryloxypropylmethyldimethoxysilane.
  • the silane coupling agent may be a polymer obtained by polymerizing the compound represented by the above general formula (II).
  • the multimer is preferably a trimer, more preferably 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate.
  • This is a condensation polymer of 3-isocyanatealkylalkoxysilane. It is known that in this 1,3,5-tris(3-trialkoxysilylalkyl) isocyanurate, the isocyan moiety has no chemical reactivity, but the reactivity is ensured by the polarity of the nurate moiety.
  • 3-isocyanate alkyl alkoxylane like 3-isocyanate alkyl alkoxylane, it is added to adhesives, etc., and is known as an adhesion improver. Therefore, by adding 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate to a hydroxyl group-containing polymer compound, the water resistance of the gas barrier coating layer can be improved due to hydrogen bonding.
  • 3-Isocyanate alkyl alkoxyrane has high reactivity and low liquid stability, whereas 1,3,5-tris(3-trialkoxysilylalkyl) isocyanurate is not water-soluble due to the polarity of the nurate moiety. However, it is easily dispersed in aqueous solutions and can maintain stable liquid viscosity. Furthermore, the water resistance properties of 3-isocyanatealkylalkoxyrane and 1,3,5-tris(3-trialkoxysilylalkyl)isocyanurate are equivalent.
  • 1,3,5-Tris(3-trialkoxysilylalkyl)isocyanurate is sometimes produced by thermal condensation of 3-isocyanatepropylalkoxysilane, and may also contain the raw material 3-isocyanatepropylalkoxysilane. However, there is no particular problem. More preferred is 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate, and more preferred is 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate. 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate is practically advantageous because the methoxy group has a high hydrolysis rate and those containing a propyl group are available at relatively low cost.
  • additives such as isocyanate compounds, dispersants, stabilizers, viscosity modifiers, colorants, etc. can be added to the coating agent as necessary, within a range that does not impair gas barrier properties. .
  • the thickness of the gas barrier coating layer is preferably 50 to 1000 nm, more preferably 100 to 500 nm. When the thickness of the gas barrier coating layer is 50 nm or more, it tends to be able to obtain more sufficient gas barrier properties, and when it is 1000 nm or less, it tends to be able to maintain sufficient flexibility.
  • the coating liquid for forming the gas barrier coating layer is, for example, a dipping method, a roll coating method, a gravure coating method, a reverse gravure coating method, an air knife coating method, a comma coating method, a die coating method, a screen printing method, a spray coating method, It can be applied by a gravure offset method or the like.
  • a coating formed by applying this coating liquid can be dried by, for example, a hot air drying method, a hot roll drying method, a high frequency irradiation method, an infrared irradiation method, a UV irradiation method, or a combination thereof.
  • the temperature at which the coating film is dried can be, for example, 50 to 150°C, preferably 70 to 100°C.
  • the gas barrier coating layer may be formed using a coating agent containing a polyvinyl alcohol resin and a silane compound.
  • An acid catalyst, an alkali catalyst, a photoheavy initiator, etc. may be added to the coating agent as necessary.
  • the polyvinyl alcohol resin is as described above.
  • examples of the silane compound include silane coupling agents, polysilazane, siloxane, etc. Specifically, tetramethoxysilane, tetraethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, hexamethyl Examples include disilazane.
  • the intermediate layer 12 For the configuration of the intermediate layer, the above description regarding the configuration of the base layer can be appropriately referred to. Further, the above-described adhesive layer, inorganic oxide layer, and gas barrier coating layer may be provided on at least one surface of the intermediate layer. By including the intermediate layer in the laminate, deformation of the laminate during bag making can be further reduced compared to a case where the intermediate layer is not provided.
  • the thickness of the intermediate layer is not particularly limited, but may be the same as the thickness of the base layer, and the ratio of the thicknesses of these layers (base layer thickness/intermediate layer thickness) is 1. 00 or more, may be more than 1.00, may be more than 1.25, and may be more than 1.50.
  • the base material layer is a portion that comes into direct contact with or is close to the heat seal bar during heat sealing, and is a portion that is particularly exposed to heat among the layers of the laminate, and is therefore susceptible to thermal contraction during heat sealing. Therefore, by making the base layer thicker than the intermediate layer, thermal shrinkage of the base layer can be suppressed.
  • the laminate may include a printed layer.
  • the printing layer can be provided on at least one surface of the base layer or on at least one surface of the intermediate layer.
  • the printing layer is provided at a position visible from the outside of the laminate for the purpose of displaying information about the contents, identifying the contents, improving concealability, or improving the design of the packaging bag.
  • the printing method and printing ink are not particularly limited, and are appropriately selected from among known printing methods and printing inks, taking into consideration suitability for printing onto a film, design characteristics such as color tone, adhesion, safety as a food container, etc. Ru.
  • As the printing method for example, a gravure printing method, an offset printing method, a gravure offset printing method, a flexo printing method, an inkjet printing method, etc. can be used. Among them, the gravure printing method can be preferably used from the viewpoint of productivity and high definition of the image.
  • the surface of the layer on which the printed layer is provided may be subjected to various pre-treatments such as corona treatment, plasma treatment, flame treatment, etc., or a coat layer such as an easy-to-adhesion layer may be provided.
  • pre-treatments such as corona treatment, plasma treatment, flame treatment, etc.
  • a coat layer such as an easy-to-adhesion layer may be provided.
  • the surface of the layer on which the printing layer is provided include the surface of the base layer or intermediate layer, and the surface of the gas barrier coating layer.
  • Adhesive layer S A base material layer and an intermediate layer can be laminated via an adhesive layer.
  • the material for the adhesive for example, polyester-isocyanate resin, urethane resin, polyether resin, etc. can be used.
  • a two-component curing type urethane adhesive having retort resistance can be preferably used. Note that from the viewpoint of environmental considerations, the adhesive does not need to contain 3-glycidyloxypropyltrimethoxysilane (GPTMS).
  • the sealant layer is a layer that provides sealing properties by heat sealing in the laminate, and contains polypropylene.
  • the sealant layer may include or consist of a polypropylene film.
  • the polypropylene film may be an acid-modified polypropylene film obtained by graft-modifying polypropylene using an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, or the like.
  • polypropylene resins such as homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene- ⁇ -olefin copolymer, etc. can be used.
  • the polypropylene film constituting the sealant layer is preferably a non-stretched film from the viewpoint of improving sealing performance by heat sealing.
  • additives such as flame retardants, slip agents, anti-blocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be added to the polypropylene film constituting the sealant layer.
  • the thickness of the sealant layer is determined by the mass of the contents, the shape of the packaging bag, etc., but may be approximately 30 to 150 ⁇ m thick, or 50 to 80 ⁇ m thick.
  • Methods for forming the sealant layer include the dry lamination method, in which the film-like sealant layer made of polypropylene mentioned above is bonded together with an adhesive such as a one-component curing type or two-component curing type urethane adhesive, and a dry lamination method in which the film-like sealant layer made of polypropylene is bonded together using an adhesive such as a one-component curing type or two-component curing type urethane adhesive.
  • It can be formed by any known lamination method, such as a non-solvent dry lamination method in which the sheets are laminated using a solvent adhesive, or an extrusion lamination method in which the above-mentioned polypropylene is heated and melted, extruded into a curtain shape, and laminated together.
  • a non-solvent dry lamination method in which the sheets are laminated using a solvent adhesive
  • an extrusion lamination method in which the above-mentioned polypropylene is heated and melted, extruded into a curtain shape, and laminated together.
  • the dry lamination method is preferred because it has high resistance to retort treatment, especially high-temperature hydrothermal treatment at 120° C. or higher.
  • the lamination method is not particularly limited.
  • the laminate 90% by mass or more of the total amount of the laminate is polypropylene.
  • the laminate can be called a packaging material made of a single material (monomaterial), and has excellent recyclability.
  • the content of polypropylene in the laminate may be 90% by mass or more, or 95% by mass or more, based on the total amount of the laminate.
  • the above-mentioned laminate has a heat shrinkage rate of 12.0% or less in both the MD direction and the TD direction as determined by the following formulas (1) and (2) after being heated in an oven at 150° C. for 15 minutes.
  • MD direction heat shrinkage rate (%) (MD direction length before heating - MD direction length after heating) / MD direction length before heating ⁇ 100 ...
  • TD direction heat shrinkage rate (%) (TD direction length before heating - TD direction length after heating) / TD direction length before heating ⁇ 100 ...
  • the laminate is a monomaterial laminate mainly composed of polypropylene (the content of polypropylene in the laminate is 90% by mass or more), Deformation during bag making can be reduced.
  • the laminate has a heat shrinkage rate in the MD direction and TD direction determined by the above formulas (1) and (2) after heating in an oven at 150°C for 15 minutes. may be 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, or 7.0% or less.
  • the laminate has a heat shrinkage rate in the MD direction of 16.0% or less as determined by the above formula (1) after being heated in an oven at 160°C for 15 minutes.
  • the thermal shrinkage rate in the TD direction determined by the above formula (2) may be 32.0% or less.
  • the laminate has a heat shrinkage rate in the MD direction of 15.0% or less as determined by the above formula (1) after being heated in an oven at 160°C for 15 minutes. , 14.0% or less, 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, or 9.0% or less.
  • the laminate has a heat shrinkage rate of 30.0 in the TD direction calculated by the above formula (2) after being heated in an oven at 160°C for 15 minutes. % or less, 27.0% or less, 25.0% or less, 23.0% or less, or 20.0% or less.
  • the base material layer has a heat shrinkage rate of 12.0% in both the MD direction and the TD direction as determined by the above formulas (1) and (2) after heating in an oven at 150°C for 15 minutes. It may be the following.
  • the base material layer is a portion that directly contacts or is close to the heat seal bar during heat sealing, and is a portion that is particularly exposed to heat among the layers of the laminate. Therefore, the thermal shrinkage rate of the base material layer greatly influences the thermal deformation of the laminate.
  • the laminate is a monomaterial laminate mainly composed of polypropylene (the content of polypropylene in the laminate is 90% by mass or more). However, deformation during bag making can be further reduced.
  • the base material layer has heat shrinkage in the MD direction and TD direction determined by the above formulas (1) and (2) after heating in an oven at 150°C for 15 minutes.
  • the percentage is 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, 5.0% or less, or 4.0% or less. good.
  • the base material layer has a heat shrinkage rate of 20.0% in the MD direction determined by the above formula (1) after being heated in an oven at 160°C for 15 minutes. and the thermal shrinkage rate in the TD direction determined by the above formula (2) may be 30.0% or less.
  • the laminate has a heat shrinkage rate of 17.0% in the MD direction determined by the above formula (1) after being heated in an oven at 160°C for 15 minutes. Below, it may be 15.0% or less, 12.0% or less, 10.0% or less, or 8.0% or less.
  • the laminate has a heat shrinkage rate of 28.0% in the TD direction calculated by the above formula (2) after being heated in an oven at 160°C for 15 minutes. It may be 0% or less, 25.0% or less, 23.0% or less, 20.0% or less, 18.0% or less, or 15.0% or less.
  • the heat shrinkage rate of the intermediate layer may satisfy the same conditions as the heat shrinkage rate of the base layer described above. Since the heat shrinkage rate of the intermediate layer also affects the thermal deformation of the laminate, if the heat shrinkage rate of the intermediate layer satisfies the above conditions, the laminate can be made mainly of polypropylene (the content of polypropylene in the laminate is 90% % by mass or more), deformation during bag making can be further reduced even in the case of a monomaterial laminate.
  • the heat shrinkage rate of the intermediate layer may be greater than or equal to that of the base material layer and greater than or equal to that of the sealant layer.
  • the heat shrinkage rate of the laminate can be reduced by sandwiching and laminating the intermediate layer between a base material layer and a sealant layer having a heat shrinkage rate lower than that of the intermediate layer. Thereby, deformation of the laminate during bag making can be further reduced.
  • the heat shrinkage rate of each layer to be compared is the heat shrinkage rate at the same heating temperature (150°C or 160°C) and in the same direction (MD direction or TD direction), and at least under any of the conditions (temperature, direction).
  • the thermal shrinkage rates of the above-mentioned laminate, base material layer, and intermediate layer are determined by heating the measurement sample in an oven at a predetermined temperature for 15 minutes, and determining the change in the length in the MD direction and the length in the TD direction before and after heating. be able to. Specifically, the heat shrinkage rate can be measured, for example, by the method shown in Examples.
  • the above-mentioned laminate is mainly composed of polypropylene and can be subjected to high-temperature retort treatment, so it can be suitably used for retort pouches.
  • the packaging bag is made by bag-making the above-mentioned laminate, and there are no particular limitations on the shape, but for example, one laminate is folded in half so that the sealant layers face each other, and then the three sides are folded. It may be made into a bag shape by heat sealing, or it may be made into a bag shape by stacking two laminates so that the sealant layers face each other and then heat sealing on four sides. Often, it may be a self-supporting standing pouch in which two laminates are stacked so that the sealant layers face each other, and the bottom material is also sandwiched and sealed.
  • the packaging bag accommodates contents such as foods and medicines, and can be subjected to heat sterilization treatment such as retort treatment and boiling treatment.
  • Retort processing is a method that sterilizes microorganisms such as mold, yeast, and bacteria under pressure in order to generally preserve foods, medicines, etc.
  • packaging bags containing foods, etc. are subjected to pressure sterilization treatment at 105 to 140°C and 0.15 to 0.30 MPa for 10 to 120 minutes.
  • pressure sterilization treatment There are two types of retort devices: a steam type that uses heated steam and a hot water type that uses pressurized heated water.
  • Boiling is a method of sterilizing foods, medicines, etc. with moist heat to preserve them.
  • a packaging bag containing foods, etc. is subjected to moist heat sterilization treatment at 60 to 100°C and under atmospheric pressure for 10 to 120 minutes, depending on the contents.
  • the boiling process is usually performed at 100°C or lower using a hot water bath.
  • a hot water bath There are two methods: a batch method, in which the material is immersed in a hot water tank at a constant temperature and treated for a certain period of time, and then taken out, and a continuous method, in which the material is passed through the hot water tank in a tunnel.
  • the above packaging bag can be particularly suitably used in applications where retort treatment is performed at a temperature of 120° C. or higher.
  • the above-mentioned packaging bag has excellent transportability and workability when sealing the contents because there is little deformation during bag making.
  • Acrylic polyol and tolylene diisocyanate are mixed so that the number of NCO groups in tolylene diisocyanate is equal to the number of OH groups in acrylic polyol, and the total solid content (total amount of acrylic polyol and tolylene diisocyanate) is ) was diluted with ethyl acetate to 5% by mass. Further, ⁇ -(3,4 epoxycyclohexyl)trimethoxysilane was added to the diluted mixed solution in an amount of 5 parts by mass based on 100 parts by mass of the total amount of acrylic polyol and tolylene diisocyanate, and these were mixed. In this way, a composition for forming an adhesive layer (anchor coating agent) was prepared.
  • composition for forming a gas barrier coating layer was prepared by mixing the following liquids A, B, and C at a mass ratio of 65/25/10, respectively.
  • Solution A 72.1 g of 0.1N hydrochloric acid was added to 17.9 g of tetraethoxysilane (Si(OC 2 H 5 ) 4 ) and 10 g of methanol, and the mixture was stirred for 30 minutes to be hydrolyzed, resulting in a solid content of 5% by mass (SiO 2 (conversion) hydrolysis solution.
  • Solution B 5% by mass water/methanol solution of polyvinyl alcohol (mass ratio of water:methanol is 95:5).
  • Solution C 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate was diluted to a solid content of 5% by mass with a mixed solution of water/isopropyl alcohol (mass ratio of water:isopropyl alcohol was 1:1). Hydrolysis solution.
  • Example 1 The above adhesion layer forming composition was applied to the corona-treated surface of the intermediate layer OPP-11 using a gravure roll coating method, dried and cured at 60°C, and the coating amount was 0.1 g/ m2 .
  • An adhesive layer made of polyurethane resin was formed.
  • a transparent inorganic oxide layer (silica vapor deposition layer) made of silicon oxide and having a thickness of 30 nm was formed using a vacuum evaporation apparatus using an electron beam heating method.
  • the silica vapor deposition layer the vapor deposition material type was adjusted to form a vapor deposition layer having an O/Si ratio of 1.8.
  • the O/Si ratio was determined using an X-ray photoelectron spectrometer (manufactured by JEOL Ltd., product name: JPS-90MXV), using non-monochromatic MgK ⁇ (1253.6 eV) as the X-ray source, and 100 W (10 kV- The measurement was performed with an X-ray output of 10 mA). Quantitative analysis to determine the O/Si ratio was performed using relative sensitivity factors of 2.28 for O1s and 0.9 for Si2p, respectively.
  • the above composition for forming a gas barrier coating layer was applied onto the inorganic oxide layer by a gravure roll coating method, and dried by heating in an oven at a tension of 20 N/m and a drying temperature of 120°C.
  • a gas barrier coating layer with a thickness of 0.3 ⁇ m was formed. Thereby, a gas barrier film having a laminated structure of intermediate layer/adhesive layer/inorganic oxide layer/gas barrier coating layer was obtained.
  • the base material layer OPP-1 is dry laminated onto the gas barrier coating layer of the gas barrier film using a two-component adhesive (manufactured by Mitsui Chemicals, Inc., product name: base material A525/curing agent A52).
  • the non-corona treated surface of the intermediate layer was corona treated and the sealant layer was laminated in the same manner.
  • a laminate having a laminate structure of base material layer/adhesive layer/gas barrier coating layer/inorganic oxide layer/adhesion layer/intermediate layer/adhesive layer/sealant layer was manufactured.
  • the content of polypropylene in the obtained laminate was 90% by mass or more.
  • Examples 2 to 7 Laminated bodies of Examples 2 to 7 were produced in the same manner as in Example 1 except that base layers OPP-2 to 7 were used in place of base layer OPP-1.
  • Example 8 The base material layer OPP-7 is laminated on the corona-treated surface of the intermediate layer OPP-11 using a two-component adhesive (manufactured by Mitsui Chemicals, Inc., product name: base material A525/curing agent A52) using a dry lamination method.
  • a two-component adhesive manufactured by Mitsui Chemicals, Inc., product name: base material A525/curing agent A52
  • corona treatment was applied to the non-corona treated surface of the intermediate layer, and a sealant layer was laminated in the same manner.
  • a laminate having a laminate structure of base layer/adhesive layer/intermediate layer/adhesive layer/sealant layer was manufactured.
  • Comparative Examples 1-2 Laminates of Comparative Examples 1 and 2 were produced in the same manner as in Example 1, except that base layers OPP-8 and OPP-9 were used in place of base layer OPP-1.
  • HS contraction rate (%) (Length of straight line before HS - Length of straight line after HS) / Length of straight line before HS x 100...(3) (e)
  • the above HS shrinkage rate was measured when the straight line was drawn parallel to the MD direction and when the straight line was drawn parallel to the TD direction, and the heat sealing of the laminate was performed based on the following evaluation criteria. The amount of deformation was evaluated. The results are shown in Table 2. If the evaluation result is A to D, it is considered a pass.
  • C The HS shrinkage rate is more than 2.5% and not more than 3.5% in the MD direction, and more than 2.0% and not more than 3.0% in the TD direction.
  • D The HS shrinkage rate is more than 2.5% and not more than 3.5% in the MD direction, and more than 3.0% and not more than 3.5% in the TD direction.
  • E HS shrinkage rate is more than 3.5% in at least one of the MD direction and the TD direction.
  • the packaging laminate according to the present disclosure can reduce deformation during bag making, and substantially all of its constituent films can be polypropylene films.
  • Such a packaging laminate can be said to be a packaging material made of a single material (monomaterial), and is expected to have excellent recyclability.

Landscapes

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

Abstract

L'invention concerne un stratifié, qui comprend au moins une couche de matériau de base, une couche intermédiaire et une couche de scellement. La couche de matériau de base, la couche intermédiaire et la couche de scellement contiennent toutes du polypropylène. 90 % en masse ou plus de l'ensemble du stratifié est constitué de polypropylène. Un retrait thermique du stratifié calculé par les équations (1) et (2) suivantes après chauffage dans un four pendant 15 minutes à 150 °C est de 12,0 % ou moins à la fois dans une direction MD et une direction TD.　(1) retrait thermique dans la direction MD (%) = (une longueur dans la direction MD avant chauffage – une longueur dans la direction MD après chauffage)/une longueur dans la direction MD avant chauffage × 100 (2) retrait thermique dans la direction TD (%) = (une longueur dans la direction TD avant chauffage – une longueur dans la direction TD après chauffage)/une longueur dans la direction TD avant chauffage × 100
PCT/JP2023/008077 2022-03-25 2023-03-03 Stratifié d'emballage et sac d'emballage WO2023181852A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-049410 2022-03-25
JP2022049410 2022-03-25

Publications (1)

Publication Number Publication Date
WO2023181852A1 true WO2023181852A1 (fr) 2023-09-28

Family

ID=88100646

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/008077 WO2023181852A1 (fr) 2022-03-25 2023-03-03 Stratifié d'emballage et sac d'emballage

Country Status (1)

Country Link
WO (1) WO2023181852A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09290477A (ja) * 1996-03-01 1997-11-11 Toppan Printing Co Ltd バリア性フィルムおよびそれを用いた包装材料
JP2018089567A (ja) * 2016-12-01 2018-06-14 凸版印刷株式会社 ガスバリア積層体及びその製造方法
WO2019065306A1 (fr) * 2017-09-26 2019-04-04 東洋紡株式会社 Film stratifié à base de polypropylène
JP2021020391A (ja) * 2019-07-29 2021-02-18 凸版印刷株式会社 積層体及び包装袋
JP2021178974A (ja) * 2018-12-28 2021-11-18 東洋紡株式会社 二軸配向ポリプロピレンフィルム

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09290477A (ja) * 1996-03-01 1997-11-11 Toppan Printing Co Ltd バリア性フィルムおよびそれを用いた包装材料
JP2018089567A (ja) * 2016-12-01 2018-06-14 凸版印刷株式会社 ガスバリア積層体及びその製造方法
WO2019065306A1 (fr) * 2017-09-26 2019-04-04 東洋紡株式会社 Film stratifié à base de polypropylène
JP2021178974A (ja) * 2018-12-28 2021-11-18 東洋紡株式会社 二軸配向ポリプロピレンフィルム
JP2021020391A (ja) * 2019-07-29 2021-02-18 凸版印刷株式会社 積層体及び包装袋

Similar Documents

Publication Publication Date Title
WO2021020400A1 (fr) Corps stratifié et sac d'emballage
WO2017170574A1 (fr) Film barrière aux gaz
JP7332070B1 (ja) ガスバリア積層体及び包装袋
WO2022131264A1 (fr) Stratifié, sac d'emballage et sachet à fond plat
WO2017209107A1 (fr) Feuille en couches, matériau d'emballage et article moulé
JP7231095B2 (ja) 積層体及び包装袋
JP2022034746A (ja) ガスバリア積層体
WO2022071248A1 (fr) Matériau d'emballage, sac d'emballage et emballage
WO2023181852A1 (fr) Stratifié d'emballage et sac d'emballage
JP7040038B2 (ja) ガスバリア積層体の製造方法
WO2024019049A1 (fr) Stratifié pour emballage, procédé de sélection associé, procédé d'évaluation associé, sac d'emballage et procédé de production associé
JP7473036B2 (ja) 積層体及び包装袋
WO2023219141A1 (fr) Film barrière contre les gaz, film d'emballage et sac d'emballage
JP2023178816A (ja) 包装用積層体及び包装袋
WO2023238825A1 (fr) Stratifié d'emballage et sac d'emballage
JP7036266B1 (ja) ガスバリアフィルム、積層体、および包装材料
JP7036265B1 (ja) ガスバリアフィルム、積層体、および包装材料
WO2024096024A1 (fr) Film multicouche coextrudé, stratifié et sac d'emballage
JP7279363B2 (ja) ガスバリアフィルムおよび包装用フィルム
WO2022270490A1 (fr) Film étanche aux gaz, stratifié et matériau d'emballage
JP2023049299A (ja) 積層体、包装材料、包装体及び包装物品
JP2024066888A (ja) 共押出多層フィルム、積層体及び包装袋
JP2023179896A (ja) 積層体、包装材料及び包装袋
JP2024066891A (ja) 共押出多層フィルム、積層体及び包装袋
JP2023183633A (ja) 積層体及びその製造方法、並びに、包装袋

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: 23774451

Country of ref document: EP

Kind code of ref document: A1