1025results about "Packing paper" patented technology

The invention discloses a double-PHA barrier system for a paper-based container and a paperboard as well as a preparation method and application of the double-PHA barrier system, and belongs to the technical field of paper-based material surface engineering and green packaging. The system sequentially comprises a paper base material, a water-based PHA dispersion hole sealing layer and a PHA extrusion compact layer from inside to outside. According to the invention, the micron-sized PHA dispersoid without cell debris is utilized, so that an efficient hole sealing effect which is difficult to achieve by a high coating amount in a traditional process can be achieved by only needing an extremely low coating amount, and the pinhole defect of an extrusion layer is eliminated from the source. And in cooperation with the modified PHA extrusion layer with the specific crystallinity, the problem of micro-cracking of a single coating during edge rolling forming is cooperatively solved. According to the system, excellent barrier performance is achieved through a thinner bio-based structure, and meanwhile the system has a wide heat sealing window and excellent repulp recycling performance. Compared with the prior art, on the premise that high performance is guaranteed, the consumption amount of packaging materials and the environmental burden are remarkably reduced.

The invention discloses a large-size green packaging carton and a preparation process thereof, and relates to the field of packaging box preparation. The environment-friendly composite material comprises the following raw materials in parts by weight: 50-80 parts of plant fiber slurry, 10-25 parts of a modified starch-based adhesive, 5-15 parts of a nanoscale inorganic reinforcing filler, 1-5 parts of a degradable water repellent agent, 0.5-3 parts of a cross-linking agent and 2-8 parts of starch and plant fiber composite buffer microspheres. According to the preparation method, full-environment-friendly raw materials such as plant fiber slurry and a modified starch-based adhesive are selected and matched with starch and plant fiber composite buffer microspheres, and optimized processes such as segmented temperature control pressurization molding, adhesive gelatinization treatment, stirring speed reduction and microsphere structure protection are combined; and through coating of the degradable polymer coating and micron-sized hydrophobic texture imprinting, synergistic improvement of high compressive strength, excellent buffering performance, excellent hydrophobic and damp-proof effects and high degradation rate of the carton is achieved.

The invention discloses a PHA-acrylic acid structural unit water-based dispersion based on interface engineering regulation and control, a preparation method thereof and application of a paper-based barrier coating, and belongs to the technical field of high polymer materials, interface engineering and water-based coatings. The stable interface layer is constructed in situ between the crystalline PHA and the acrylic resin through the amphiphilic polymer, so that the problems of poor compatibility and film forming defects of a bio-based material are effectively solved. The dispersion can realize excellent waterproof, oil-proof and gas barrier effects by only needing a relatively low coating weight, and the material consumption is remarkably reduced. The unique gradient structure of the coating has excellent mechanical adhesive force and efficient re-pulping and recycling characteristics, and the technical defect that a traditional barrier coating is difficult to recycle is overcome. And an ideal solution with high performance and high safety is provided for green packaging.

The invention relates to the field of packaging materials, and discloses low-temperature heat-sealing water-based coated paper and a preparation method and application thereof.The water-based coated paper comprises a base paper layer and a water-based coating, and the water-based coating comprises water-based ethylene-acrylic acid copolymer emulsion, modified nano-silica, a coalescing agent and water; a cardanol derivative is introduced into the water-based ethylene-acrylic acid copolymer emulsion as a functional component; the cardanol derivative is prepared by reacting epoxidized cardanol with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and then grafting with acryloyl chloride. The preparation method comprises the following steps: reacting epoxidized cardanol with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; the modified nano silicon dioxide is prepared by mixing aminated nano silicon dioxide and chitosan and adding a cross-linking agent prepared by grafting phytic acid and ethylene glycol diglycidyl ether. The water-based coating paper prepared by the invention overcomes the defects that the existing BOPP film is not environment-friendly, and the conventional coating paper is high in heat sealing temperature and easy to stick; meanwhile, good mechanical properties, water resistance and flame retardance are achieved.

The invention discloses a compostable and reslurrable mineral-based dual-scale barrier coating as well as preparation and application thereof, and belongs to the technical field of water-based and reslurrable barrier materials. In order to overcome the defects of high coating weight, large color difference or difficulty in recovery in the prior art, a compact barrier is constructed through double-scale collaborative design of interlayer intercalation of layered double hydroxides and interparticle metal micro-networks. The method has the prominent advantage that high-efficiency water-oxygen barrier better than that of a conventional scheme can be realized only by using an extremely low coating amount. Meanwhile, the coating strictly controls color difference to maintain high whiteness of the paper, has pH responsiveness, can be quickly unlapped and dispersed under an acidic condition, and is easy to re-pulp. The coating does not contain PFAS and PVDC, and unification of high barrier, high whiteness and recoverability is achieved.

The invention discloses a water-based PHA (Polyhydroxyalkanoate) coating and PHA extrusion layer compounded paper-based high-barrier material as well as a preparation method and application thereof, and belongs to the technical field of biodegradable high polymer materials and environment-friendly packaging. According to the scheme, a double-component system with a specific melting point difference is innovatively introduced to construct the water-based pre-coating layer, and efficient sealing and strong anchoring of a rough base material can be achieved under the extremely low coating weight by means of the double mechanisms of'microcosmic leveling and interface thermal fusion '. Compared with a traditional thick-layer lamination process, the material achieves more excellent barrier integrity and oil-resistant and moisture-resistant performance through a thinner extrusion surface layer, the moisture-resistant and oxygen-resistant performance is remarkably improved, and meanwhile the requirement for puncture resistance of dry and hard food packaging materials is thoroughly met through the unique double-layer system stress balance design. The material does not contain fluorine additives, is completely biodegradable, and meets the high-standard requirements of food safety and compliance.

The invention discloses a bacteriostatic and antiviral bamboo pulp paper-based sanitary isolation bag as well as a preparation method and application thereof, and belongs to the field of functional paper-based packaging materials. The isolation bag takes bamboo pulp fiber paper as a base material, and the surface of the isolation bag is coated with a water-based polyhydroxyalkanoate functional coating. According to the preparation method, a special polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor is introduced, and the problem of agglomeration of nano particles is effectively solved by utilizing the special bridging effect of polyphenol, so that high-density cation capture and oxidation inactivation sites are constructed on the surface of the coating. Compared with the prior art, the method has the advantages that the method does not need to depend on organic fluorine compounds, and the excellent waterproof and oil-proof barrier effect and the efficient inactivation of viruses can be achieved only through the extremely low coating amount. In addition, the isolation bag has unique environmental chemical responsiveness, can be efficiently dissociated under the alkaline condition to facilitate repulping recovery, can be completely biodegraded in the natural environment, and perfectly considers the requirements of biological safety protection and green environmental protection.

The invention belongs to the technical field of corrugated paperboards, and is characterized in that wood fibers and modified bamboo fibers prepared by reaction of allyl bamboo fibers, 1, 4-butanediol di (mercaptoacetate) and magnolol are pulped, a biodegradable water-resistant auxiliary agent is added for hydrophobic modification, papermaking and shaping are carried out to prepare water-resistant base paper, and the water-resistant base paper is prepared by the following steps: pulping the modified bamboo fibers and the biodegradable water-resistant auxiliary agent. And finally, preparing a surface paper layer, a corrugated medium paper layer and an inner paper layer from the water-resistant raw paper, and bonding and pressing to obtain the corrugated board. Magnolol groups grafted on the surfaces of the modified bamboo fibers can improve the water absorption performance of the fibers, and the hydrophobicity of the corrugated board is improved through the synergistic effect of the magnolol groups and the biodegradable water-resistant auxiliaries; the surface of the biodegradable water-resistant auxiliary agent is embedded with a carboxylated nano-cellulose structure, so that the biodegradable water-resistant auxiliary agent has deformation resistance; the epoxidized soybean oil is used as a core part and has excellent hydrophobicity; through combination of a polyphenol structure of tannic acid and hydrogen bonds of water-resistant base paper fibers, the mechanical properties of the corrugated board are improved, and the corrugated board has excellent biodegradability, hydrophobicity and mechanical strength.

The invention discloses a silica powder modified paperboard material of embossed frame paper for cigarettes and a preparation method of the silica powder modified paperboard material, and belongs to the field of advanced inorganic non-metallic materials. The material comprises bleached chemical wood pulp, core-shell structure in-situ modified nano silicon micropowder, an auxiliary agent and a latent temperature-sensitive cross-linking agent, a modification system contains a compound silane coupling agent and amino modified organosilane, and a dual network of static triple cross-linking and dynamic secondary cross-linking is formed; the nanometer silicon micro powder is of a core-micro-nano protrusion-shell multilevel structure, a shell layer is thermoplastic resin containing latent epoxy groups, and a double-peak particle size distribution design is adopted. The preparation process is realized through in-situ generation modification, high-speed shearing fusion and an embossing-shaping integrated closed-loop control process, and is adaptive to an existing fourdrinier papermaking production line. The product quantification is 210-220 g / m < 2 >, the transverse stiffness is larger than or equal to 210 mN.m, the embossing retention rate is larger than or equal to 99.5%, after 50 cycles at the temperature of-5 DEG C-40 DEG C and the humidity of 30%-80%, the stiffness is reduced by smaller than or equal to 3%, the barrier property is reduced by smaller than or equal to 6%, the printing adsorption uniformity error is smaller than or equal to 3%, and the barrier property and the environmental protection property are excellent. The method solves the problems of agglomeration, embossing resilience, multi-performance contradiction, poor environmental stability and other pain points of conventional modified filler, realizes the cooperation of low quantification and high performance, conforms to the high-end and green requirements of the tobacco industry, can pass the application of strategic emerging industry priority review channels, and has a wide application prospect.

The present invention relates to a method for manufacturing a barrier-coated substrate web, coated with a layer of reduced graphene oxide. The invention further relates to laminated packaging materials comprising the barrier-coated substrate web, in particular intended for liquid carton food packaging, and to liquid carton packaging containers comprising the laminated packaging material.

The invention relates to the technical field of papermaking, in particular to a preparation method of high-definition electronic screen protection paper. According to the method, regenerated cellulose fibers serve as main raw materials, functional composite fibers of a core-shell structure are constructed, a core layer is the regenerated cellulose fibers, a shell layer is a polypyrrole / graphene composite conductive layer, and the lasting antistatic performance is achieved; meanwhile, the surface-modified nano silicon dioxide aerogel particles are introduced, so that the optical performance and the mechanical strength are improved; then compounding with polyimide fibers modified by a silane coupling agent, adding a bio-based wet strength agent and a fluorocarbon defoaming agent, and carrying out the steps of plasma pretreatment, pulping, on-net papermaking, controllable drying, magnetron sputtering surface treatment and the like to prepare the protective paper. The obtained protective paper has the characteristics of being ultrathin, high in strength, high in light transmittance, lasting in antistatic property and the like, and is suitable for protection of high-end liquid crystal display screens and OLED screens.

A repulpable insulation material includes a batt formed of a mixture of thermoplastic binder fibers and cellulose fibers bound together by the thermoplastic binder fibers, the thermoplastic binder fibers making up about 0.5% to 25% by weight of the batt, the repulpable insulation material having a weight within a range from 1000 GSM to 1600 GSM, wherein subjecting the repulpable insulation material to a repulpability test produces greater than 85% fiber yield.

The invention discloses environment-friendly degradable forming paper with self-cleaning and oil-proof functions for cigarettes and a preparation method of the environment-friendly degradable forming paper. The forming paper is composed of bamboo pulp base paper, a composite oil adsorption resisting layer and a biological source super-hydrophobic coating. In the middle layer, polylactic acid emulsion is matched with diatomite and activated carbon to form a microporous network, and the pore diameter peak value is 50-150 nm to inhibit oil seepage; the outer layer is formed by compounding vegetable wax, AKD, chitosan and double-particle-size SiO (10-20 nm and 120-280 nm), and surface layer particle enrichment and a thickness-direction asymmetric structure are achieved through wet stacking and wet continuous coating and double-section flash evaporation drying. The structure has the advantages of low surface energy, high hydrocarbon contact angle and good wear-resistant adhesion while keeping degradability and air permeability, and is suitable for the antifouling and cleaning requirements of cigarette appearances.

The present invention relates to a solid cellulose foam object comprising a first solid cellulose foam portion attached to a second solid cellulose foam portion. optionally at least one additional solid cellulose foam portion may be attached to the first and / or the second solid cellulose foam portion. The invention also relates to a method for producing said solid cellulose foam object.

The invention relates to the technical field of paper preparation, in particular to environment-friendly water-resistant paper as well as a preparation method and application thereof. The water-resistant paper is prepared by physically embossing a hydrophobic paper semi-finished product and then coating the hydrophobic paper semi-finished product with a hydrophobic coating. The hydrophobic paper semi-finished product is prepared from the following components in parts by weight: 65 to 80 parts of hydrophobic modified lignin fiber, 10 to 20 parts of an adhesive, 2 to 5 parts of a waterproof agent, 5 to 15 parts of filler, 0.05 to 0.1 part of a filter aid and 0.5 to 1 part of an antioxidant. The water-resistant paper not only has the characteristics of excellent water resistance, instant water resistance, pollution resistance, self-cleaning, no toxicity, easiness in degradation, recoverability and environmental protection, but also has firm wet mechanical strength and long service life, meets the urgent demand of the market on environment-friendly paper, conforms to the European Union laws and regulations, can also improve the additional value and profit margin of common paper, and has wide application prospects. Industrial upgrading and product differentiation competition are brought to the papermaking industry, and wide application prospects are achieved.

Methods of making films with feedstock comprising biomass. The methods include treating a feedstock comprising biomass with an acidic aqueous solution to yield a solid phase and a liquor, generating a forming fluid with the liquor, and generating a film from the forming fluid. Some versions include comminuting the solid phase to generate a comminuted solid phase and including the comminuted solid phase in the forming fluid. The biomass preferably contains relatively high amounts of pectin and protein. The films can be in the form of standalone films or coatings on substrates such as paper. The films provide oil and grease resistance and air impermeability, among other advantages.

The invention relates to the technical field of papermaking and food packaging materials, in particular to a preparation method of full-degradable plastic-substituted high-strength food packaging paper. Preparing a fiber layer by taking plant fiber as a base material; the preparation method comprises the following steps: grafting a methyl methacrylate-butyl acrylate block copolymer on nano-cellulose through an atom transfer radical polymerization technology to prepare enhanced nano-cellulose; dialdehyde starch rich in aldehyde groups and chitosan are subjected to a Schiff base reaction to form a dynamic cross-linked network, polylactic acid microspheres modified by beta-cyclodextrin are introduced to serve as supramolecular enhancement units, and functional coating liquid is prepared; and finally, coating the functional coating liquid on the fiber layer, and drying, cross-linking and curing to obtain a finished product. Through cooperation of chemical grafting, dynamic covalent bonds and supramolecular action, the packaging paper is endowed with extremely high strength and toughness and excellent oil and moisture resistance and heat sealability, meanwhile, it is ensured that the packaging paper can be completely biodegraded in the natural environment, and functional replacement of traditional plastic packaging is successfully achieved.

The invention discloses moisture-proof and moisture-retaining frame paper and a preparation method thereof, and relates to the technical field of frame paper.The moisture-proof and moisture-retaining frame paper comprises a body paper layer, the body paper layer is provided with a water-based moisture-retaining coating, the water-based moisture-retaining coating is formed by drying coated water-based moisture-retaining coating liquid, and the water-based moisture-retaining coating liquid is coated on the body paper layer. A composite aluminum foil layer or a transfer aluminum plating layer is also arranged on the water-based moisture-retaining coating; the water-based moisture-retaining coating liquid comprises starch, acrylic acid, organic bentonite, alkali, an initiator, a cross-linking agent and distilled water; wherein the mass ratio of the starch to the acrylic acid to the organic bentonite is (7-8): (15-20): (1-1.5); the mass of the distilled water is 10-12 times of the total mass of the starch, the acrylic acid and the organic bentonite; the mass of the initiator is 0.5-0.8% of that of the acrylic acid; the mass of the cross-linking agent is 0.1-0.2% of that of the acrylic acid; in terms of-OH, the mole number of the alkali is 70-80% of that of the acrylic acid. The frame paper is provided with the water-based moisture-retaining coating and is excellent in moisture-proof and moisture-retaining performance.

The preparation method of the environment-friendly anti-aging packaging base paper comprises the following steps: taking softwood pulp and dissolving pulp, pulping for the first time, adding microcrystalline cellulose, and stirring to form first pulp; adjusting the pH value of the first slurry to be neutral, adding a water-soluble chitosan-polyphenol compound, and pulping for the second time to form second slurry; adding oxidized sodium alginate into the second pulp, and pulping for the third time to form third pulp; forming raw paper according to a papermaking process; the invention further provides packaging base paper which has the characteristic of good anti-aging performance. Softwood pulp and dissolving pulp are used as papermaking raw materials, microcrystalline cellulose, a water-soluble chitosan-polyphenol compound and oxidized sodium alginate are used, a pulping process which is sequentially added according to a sequence is formed, a stable fiber network is constructed layer by layer, and a mechanism of skeleton supporting, covalent crosslinking and antioxidant end capping is formed. The anti-aging performance of the raw paper is improved.

The invention belongs to the field of biomass-based functional materials, relates to a difunctional coating based on enzymolysis modified cassava starch as well as a preparation method and application of the difunctional coating, and innovatively solves the technical problem that a single coating gives consideration to oil prevention and water absorption through a synergistic technical path of pretreatment and composite enzymolysis. The core mechanism is as follows: the starch particle structure is destroyed through pretreatment, and the degradation degree of starch is accurately controlled through the synergistic effect of alpha-amylase and saccharifying enzyme, so that an unexpected technical effect is achieved, and an enzymolysis product with a film-forming skeleton (medium molecular weight dextrin) and a hydrophilic unit (small molecular saccharide) is formed; meanwhile, a compact and continuous network structure can be formed by a film-forming framework, and grease permeation is blocked; and the hydrophilic unit endows the coating with a rapid capillary water absorption effect.

The invention discloses a high-toughness carton and a preparation method thereof, and relates to the technical field of papermaking and environment-friendly packaging materials. The carton is made of a high-toughness composite corrugated board, and raw materials of the carton comprise main material pulp fibers, cross-linked modified nanocellulose, a modified starch adhesive, a wet strength agent and a rheology modifier. The cross-linked modified nano-crystalline cellulose is nano-crystalline cellulose of which the surface is grafted with a hyperbranched supramolecular cross-linking agent. According to the method, by preparing the nanocellulose with the surface grafted with the hyperbranched cross-linking agent, a mechanism capable of dissipating energy is constructed in a fiber network, and compared with the prior art, the defect that regenerated fibers are large in brittleness can be effectively overcome, and the dynamic impact toughness of the carton is remarkably improved. By using the modified starch adhesive disclosed by the invention, an adhesive layer has better ductility and interlayer binding force, and when a paperboard is stressed and deformed, the adhesive layer can be deformed along with the deformation and is not easy to break, so that the stability of interlayer binding is favorably kept.

The invention belongs to the technical field of novel environment-friendly printing and water-based packaging protection materials, and discloses high-wear-resistance degradable water-based plastic-replacing oil, a preparation method and application of the high-wear-resistance degradable water-based plastic-replacing oil. Water-based matte polyurethane, a water-based acrylic polymer and water-based bright polyurethane serve as core film-forming substances, and water-based matte polyurethane, water-based acrylic polymer and water-based bright polyurethane serve as core film-forming substances; degradable reinforcing agents such as nano-crystalline cellulose and functional auxiliaries are compounded, and a step-by-step dispersion technology is adopted for preparation. Through cooperation of the formula and the technology, the comprehensive performance that the A4 paper is resistant to abrasion for more than 3000 times, the natural biodegradation rate is more than 3000 times, the folding and explosion resistance is 30 times and the like can be achieved, complex chemical modification is not needed in the technology, the production period is remarkably shortened, a traditional BOPP film covering technology can be replaced, and the method is suitable for a high-speed printing and packaging production line and is suitable for protection of various paper packages such as digital electronics, cosmetics and tobacco and wine. The problems that a traditional BOPP covering film is difficult to degrade, wear resistance and degradation of existing water-based plastic replacing oil are difficult to consider, and quick drying conflicts with film forming are solved.

The invention discloses an environment-friendly fluoride-free bio-based paper protective coating easy to recycle as well as preparation and application thereof, and belongs to the technical field of paper-based packaging materials. The composition is mainly prepared by compounding a polyhydroxyalkanoate emulsion and a water-based acrylic polymer with a specific acid value and glass transition temperature. According to the scheme, a unique pH response switch is constructed, and the contradiction that an existing bio-based coating is high in brittleness and water resistance and alkaline repulping are difficult to consider at the same time is effectively solved on the premise of not depending on wax and additionally adding a cross-linking agent or a high-content surfactant. Compared with a traditional multi-component or high-energy-consumption recovery scheme on the market, the method has the advantages that excellent oil-proof and barrier properties and efficient fiber recovery under mild conditions can be realized only by a simple binary system, the formula complexity and the recovery cost are remarkably reduced, and the method has excellent environmental protection benefits and industrial application values.

The application discloses a multi-carboxyl copolymer aqueous composition for pulp adding in packaging paperboard, synergism in short-stay pulp of packaging paper and fiber synergism in wet end of bamboo pulp paper, and a preparation and application method thereof, and belongs to the technical field of pulp and paper chemicals and wet end chemical control. The composition contains carboxyl-rich copolymer, and can be selected as high filtration rate homogeneous aqueous solution type, flexible type acid or bamboo pulp low cation density copolymer according to paper types, and is prepared through water phase free radical polymerization. In application, the composition is diluted and then added in a divided mode after a fan pump outlet to a pressure screen inlet or after a cationic polyacrylamide retention agent or in a bamboo pulp system. The method is beneficial to improving fiber combination, drainage stability, first-pass retention rate, white water stability and paper strength, and improving the adaptability of wet end dosing windows of different paper types.

To provide a paper blister pack with excellent opening properties. [Solution] It has a base part and a container part formed from a paper blank, The fused pieces of the base portion and the container portion are both provided with a heat seal layer, and are fused together via the heat seal layer. The aforementioned paper blanks have a basis weight of 150 g / m². 2 More than 300g / m 2 The following base paper is provided, with crease lines and perforations formed on it: A paper blister pack in which at least a portion of the perforations is formed on the fused side of the side panel.

A wrapping sheet includes paper. A surface of the wrapping sheet is subjected to printing while the wrapping sheet is conveyed in a fiber direction of the wrapping sheet, and the wrapping sheet individually wraps an absorbent article. A tensile strength of the wrapping sheet in the fiber direction is 16 N or greater and 25 N or less. The wrapping sheet satisfies 8.45 ≤ X × (1 - Y / 100), where X (N) is the tensile strength of the wrapping sheet in the fiber direction before the printing, and Y (%) is a ratio of an area of the wrapping sheet, to which an ink for the printing, a heat seal agent for adhering portions of the wrapping sheets, or both are applied, to an entire area of the wrapping sheet.

A low basis weight, low opacity paper is disclosed. The low opacity paper is made from a fiber web containing highly refined cellulose fibers. The fiber web is coated with a bio-based wax such as coconut-based wax, palm-based wax, or soy-based wax. The resulting product may have a relatively low basis weight and relatively low opacity. Therefore, the product may have excellent transparency or translucency characteristics.

A food-packaging material is provided which comprises a paper substrate having a surface and a coating comprising exfoliated graphene oxide on the surface of the substrate, wherein the exfoliated graphene oxide is present at an amount of less than 1 wt %. Methods of making the food-packaging material and methods of using the food-packing material are also provided.

The present disclosure provides a heat-sealable paper product for use in overwrapping, wherein the heat-sealable paper product: —comprises a paper substrate being a machine-glazed (MG) kraft paper having a glazed side and a non-glazed side, wherein the glazed side of the MG kraft paper is coated with a heat-sealable coating; —has thickness of equal to or below 85 μm according to ISO 534:2011; —has a tensile energy absorption (TEA) in cross direction (CD) of at least 60 J / m2 according to ISO 1924-3:2011; and—has a burst strength of at least 170 kPa according to ISO 2758:2014. The present disclosure also provides a method of producing a heat-sealable paper product for use in overwrapping as well as a method of overwrapping an item in a heat-sealable paper product.

The present invention provides a barrier paper that can suppress the decrease in barrier properties when folded, and also has good heat seal strength, suitability for bag making, and blocking suppression properties. [Solution] A barrier paper according to one aspect of the present invention comprises a base material, a gas barrier layer laminated on one or both sides of the base material, and a water vapor barrier layer laminated on the surface of the gas barrier layer, wherein the gas barrier layer mainly consists of polyvinyl alcohol, the water vapor barrier layer contains a wax resin and a styrene-acrylic copolymer as its main component, the amount of wax resin in the water vapor barrier layer is 3 parts by mass or more and 11 parts by mass or less per 100 parts by mass of styrene-acrylic copolymer, the gas barrier layer contains an inorganic compound in an amount of 15 parts by mass or less per 100 parts by mass of polyvinyl alcohol, or does not contain an inorganic compound, and the water vapor barrier layer does not contain an inorganic compound.