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
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
  • B32B37/24—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate
• • 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
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/10—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of paper or cardboard
• • 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
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B29/00—Layered products comprising a layer of paper or cardboard
  • B32B29/06—Layered products comprising a layer of paper or cardboard specially treated, e.g. surfaced, parchmentised
• • 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
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
• • 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
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/023—Optical properties
• • 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
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D167/00—Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain; Coating compositions based on derivatives of such polymers
  • C09D167/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/10—Coatings without pigments
  • D21H19/14—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12
  • D21H19/20—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/80—Paper comprising more than one coating
  • D21H19/82—Paper comprising more than one coating superposed
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/30—Multi-ply
• • 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
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
  • B32B37/24—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate
  • B32B2037/243—Coating
• • 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
  • B32B2250/00—Layers arrangement
  • B32B2250/02—2 layers
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/12—Coating on the layer surface on paper layer
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/26—Polymeric coating
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/40—Properties of the layers or laminate having particular optical properties
  • B32B2307/406—Bright, glossy, shiny surface
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/726—Permeability to liquids, absorption
  • B32B2307/7265—Non-permeable
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/732—Dimensional properties
  • B32B2307/737—Dimensions, e.g. volume or area
  • B32B2307/7375—Linear, e.g. length, distance or width
  • B32B2307/7376—Thickness
• • 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
  • B32B2439/00—Containers; Receptacles
• • 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
  • B32B2553/00—Packaging equipment or accessories not otherwise provided for
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W90/00—Enabling technologies or technologies with a potential or indirect contribution to greenhouse gas [GHG] emissions mitigation
  • Y02W90/10—Bio-packaging, e.g. packing containers made from renewable resources or bio-plastics

Definitions

• the present invention relates to a laminate having a resin layer containing a poly(3-hydroxybutyrate) resin, and a molded article containing the laminate.
• biodegradable plastics are known, among which poly(3-hydroxybutyrate) resin is produced and accumulated as an energy storage substance within the cells of many microbial species. It is a thermoplastic polyester that can biodegrade not only in the soil but also in seawater, so it is attracting attention as a material that can solve the above problems.
• a laminate made by laminating a layer containing a poly(3-hydroxybutyrate) resin on a biodegradable paper base material is because both the resin and the base material are materials with excellent biodegradability. , which is extremely promising from an environmental protection perspective.
• Patent Document 1 discloses that poly(3-hydroxybutyrate), a type of resin, is coated on a paper base material for the purpose of reducing coating defects.
• a coated paper having a coating layer containing a specific ratio of hydroxybutyrate-co-3-hydroxyhexanoate) and an adhesive such as polyvinyl alcohol is described.
• the coated paper described in Patent Document 1 has a certain degree of water resistance and heat sealability, but the binding between the coating layer and the paper base material is insufficient, and the coating layer does not adhere to the paper base material. Therefore, depending on the heating conditions during heat sealing, for example, it may not be possible to achieve good heat sealability. Furthermore, when the coated paper is used by forming paper containers such as paper tableware, a high level of water resistance (e.g., long-term water resistance against hot water) may be required, but Patent Documents 1, such high level of water resistance was not considered.
• a high level of water resistance e.g., long-term water resistance against hot water
• the present invention provides a laminate having a resin layer containing a poly(3-hydroxybutyrate) resin on a paper base material, which has both good binding properties and water resistance.
• the purpose is to provide
• the present invention provides a laminate including a paper base layer and a first resin layer provided on at least one surface of the paper base layer, wherein the first resin layer is made of poly(3- hydroxybutyrate)-based resin and polyvinyl alcohol with a saponification degree of less than 90 mol%, the solid content weight ratio of the poly(3-hydroxybutyrate)-based resin/the polyvinyl alcohol is 99.8/ It relates to a laminate having a ratio of 0.2 to 95.0/5.0.
• the present invention also provides a method for producing a laminate, comprising the steps of: applying a water-based coating liquid to at least one surface of a paper base material and drying it to form a first resin layer on the paper base material.
• the aqueous coating liquid contains a poly(3-hydroxybutyrate) resin and a polyvinyl alcohol having a saponification degree of less than 90 mol%, and the poly(3-hydroxybutyrate) resin/the
• the present invention also relates to a method for producing a laminate in which the solid content weight ratio of polyvinyl alcohol is from 99.8/0.2 to 95.0/5.0.
• a laminate having a resin layer containing a poly(3-hydroxybutyrate) resin on a paper base material, which has both good binding properties and water resistance. be able to.
• the laminate according to a preferred embodiment exhibits long-term water resistance against hot water, and can be used by being formed into a paper container such as paper tableware.
• the laminate according to the preferred embodiment can exhibit good heat sealability even when heat sealing is performed at a relatively low heating temperature.
• the laminate according to another embodiment further includes a second resin layer, and has good adhesiveness (laminability) between the paper base layer and the second base layer.
• a laminate according to an embodiment of the present disclosure includes at least a paper base layer and a first resin layer laminated on one or both sides of the paper base layer.
• the laminate can exhibit biodegradability as a whole.
• the first resin layer may be directly laminated on the paper base layer or may be laminated via another layer, but it is preferable that it is directly laminated.
• the first resin layer may be the outermost layer in the laminate.
• the first resin layer can function as a heat-sealing layer, a water-resistant layer, an oil-resistant layer, and the like.
• another layer may be laminated on the first resin layer.
• the first resin layer can function as an anchor coat layer between the paper base layer and the other layer.
• the another layer is not particularly limited and may be a resin layer or an inorganic layer, and an example is a second resin layer described below.
• the paper base layer is mainly composed of a sheet made of pulp.
• the paper base material can be obtained by paper-making a paper stock containing pulp, filler, various auxiliary agents, and the like.
• the types of paper that can be used as the paper base material are not particularly limited, and include cup base paper, kraft paper, high-quality paper, coated paper, thin paper, glassine paper, paperboard, and the like.
• the pulp is not particularly limited, and examples thereof include chemical pulps such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), softwood unbleached pulp (NUKP), and sulfite pulp.
• chemical pulps such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), softwood unbleached pulp (NUKP), and sulfite pulp.
• Mechanical pulps such as stone grind pulp and thermomechanical pulp
• Wood fibers such as deinked pulp and waste paper pulp
• the filler is not particularly limited and includes, for example, talc, kaolin, calcined kaolin, clay, heavy calcium carbonate, light calcium carbonate, white carbon, zeolite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, and amorphous.
• Inorganic fillers such as silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, barium sulfate, calcium sulfate; organic fillers such as urea-formalin resin, polystyrene resin, phenolic resin, micro hollow particles, etc. Can be mentioned. Note that the filler is not an essential material and may not be used.
• auxiliary agents are not particularly limited, and include, for example, sizing agents such as rosin, alkyl ketene dimer (AKD), and alkenyl succinic anhydride (ASA), polyacrylamide-based polymers, polyvinyl alcohol-based polymers, cationized starch, Various modified starches, dry paper strength enhancers such as urea/formalin resin, melamine/formalin resin, wet paper strength enhancers, retention agents, freeness improvers, coagulants, sulfuric acid, bulking agents, dyes, fluorescent whitening agent, pH adjuster, antifoaming agent, ultraviolet inhibitor, antifading agent, pitch control agent, slime control agent, etc. These may be appropriately selected and used as required.
• sizing agents such as rosin, alkyl ketene dimer (AKD), and alkenyl succinic anhydride (ASA), polyacrylamide-based polymers, polyvinyl alcohol-based polymers, cationized starch, Various modified starches,
• the surface of the paper base material may be treated with various chemicals.
• the drug is not particularly limited, and includes, for example, oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch, polyacrylamide, polyvinyl alcohol, surface sizing agent, water resistance agent, water retention agent, thickener, lubricant, and the like. Only one type of drug may be used, or two or more types may be used in combination. Further, these drugs and pigments may be used in combination.
• Pigments are not particularly limited, and include, for example, kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid,
• examples include inorganic pigments such as silicates, colloidal silica, and satin white; and organic pigments such as solid type, hollow type, and core-shell type. As the pigment, only one type may be used, or two or more types may be used in combination.
• the surface treatment method is not particularly limited, and known coating methods such as rod metering size press, pound type size press, gate roll coater, spray coater, blade coater, curtain coater, etc.
• a device can be used.
• the first resin layer provided on at least one surface of the paper base layer contains at least a poly(3-hydroxybutyrate)-based resin and polyvinyl alcohol exhibiting a specific degree of saponification.
• the resin component contained in the first resin layer may be only the poly(3-hydroxybutyrate) resin and the polyvinyl alcohol, or may further contain another resin.
• a biodegradable resin described below can be used as the other resin.
• P3HB refers to a homopolymer having 3-hydroxybutyrate units and/or a copolymer containing 3-hydroxybutyrate units and other hydroxyalkanoate units. From the viewpoint of seawater degradability, it is preferable to include a copolymer containing a 3-hydroxybutyrate unit and another hydroxyalkanoate unit.
• the hydroxyalkanoic acid constituting the copolymer is not particularly limited, and in addition to 3-hydroxybutanoic acid, for example, 4-hydroxybutanoic acid, 3-hydroxypropionic acid, 3-hydroxypentanoic acid, 3-hydroxyhexane
• 3-hydroxybutanoic acid for example, 4-hydroxybutanoic acid, 3-hydroxypropionic acid, 3-hydroxypentanoic acid, 3-hydroxyhexane
• acids include acids, 3-hydroxyheptanoic acid, 3-hydroxyoctanoic acid, and the like.
• the first resin layer preferably contains PHBH in an amount of 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, and even more preferably 90% by weight or more.
• the resin component contained in the first resin layer may be only PHBH and the polyvinyl alcohol, or may further contain another resin.
• Examples of the resin other than PHBH and the polyvinyl alcohol include P3HB other than PHBH.
• aliphatic polyester resins such as polycaprolactone, polybutylene succinate adipate, polybutylene succinate, and polylactic acid
• aliphatic aromatic polyester resins such as polybutylene adipate terephthalate and polybutylene azelate terephthalate, etc.
• biodegradable resins are also mentioned.
• PHBH A specific method for producing PHBH is described, for example, in International Publication No. 2010/013483.
• commercially available PHBHs include Kaneka Biodegradable Polymer Green Planet (registered trademark) by Kaneka Corporation.
• the average content ratio of 3HH in PHBH is 3 mol % or more, good adhesiveness can be obtained by heat sealing.
• PHBH having an average content ratio of 3HH of 25 mol % or less has a crystallization rate that is not too slow and is relatively easy to manufacture.
• the average content ratio of each constituent monomer in PHBH can be determined by a method known to those skilled in the art, for example, the method described in paragraph [0047] of International Publication No. 2013/147139, or by NMR measurement.
• the average content ratio means the molar ratio of 3HB and 3HH in the entire PHBH contained in the first resin layer, and when the PHBH is a mixture containing at least two types of PHBH, or when the PHBH is a mixture containing at least one type of PHBH, , PHB, it means the molar ratio of each monomer contained in the entire mixture.
• the weight average molecular weight (hereinafter sometimes referred to as Mw) of P3HB contained in the first resin layer can be selected as appropriate, but from the viewpoint of achieving both mechanical properties and processability, it is 50,000 to 700,000. It is preferably from 100,000 to 600,000, and even more preferably from 150,000 to 550,000.
• Mw weight average molecular weight
• PVA is usually a saponified product of a vinyl ester polymer (a polymer containing at least a vinyl ester monomer as a constituent monomer).
• a vinyl ester polymer a polymer containing at least a vinyl ester monomer as a constituent monomer.
• PVA having a saponification degree of less than 90 mol% is used.
• PVA which has a relatively low degree of saponification, has slightly suppressed hydrophilicity, and improves compatibility with P3HB, which further improves the binding between the paper base layer and the first resin layer.
• PVA with a saponification degree of 90 mol% or more has extremely high hydrophilicity and tends to have low compatibility with P3HB, resulting in insufficient binding between the paper base layer and the resin layer. .
• the degree of saponification of the PVA may be 89 mol% or less. Moreover, it may be 85 mol% or less, 80 mol% or less, or 75 mol% or less.
• the lower limit is not particularly limited, but is preferably 60 mol% or more, more preferably 65 mol% or more, and even more preferably 70 mol% or more.
• PVA exhibiting such a degree of saponification commercially available products can be used.
• the degree of saponification of PVA can be measured, for example, by the method specified in JIS K6726.
• 28-98 manufactured by Kuraray Co., Ltd. which is a completely saponified PVA used in Example 1 of Patent Document 1, has a degree of saponification of about 98 to 99 mol%, and is used in Example 9 of the same document.
• RS1713 manufactured by Kuraray Co., Ltd. which is a partially saponified ethylene-vinyl acetate copolymer (ethylene-modified PVA), has a saponification degree of 92 to 94 mol%, and both have a saponification degree of 92 to 94 mol%. It is outside the numerical range.
• PVA may have units derived from monomers other than vinyl alcohol and vinyl ester monomers (that is, it may be modified with other monomers).
• olefin-modified (e.g., ethylene-modified) PVA has higher lipophilicity, which lowers its affinity with the paper base material and reduces the binding property between the paper base layer and the resin layer. Therefore, it is preferable to use PVA that has not been subjected to olefin modification.
• the content ratio of P3HB and PVA in the first resin layer is set so that the solid content weight ratio of P3HB/PVA is within the range of 99.8/0.2 to 95.0/5.0.
• the content ratio of P3HB and PVA in the first resin layer is set so that the solid content weight ratio of P3HB/PVA is within the range of 99.8/0.2 to 95.0/5.0.
• the solid content weight ratio of P3HB/PVA is preferably 99.5/0.5 to 95.0/5.0, more preferably 99.0/1.0 to 96.0/4.0, More preferably 98.5/1.5 to 96.5/3.5, particularly preferably 98.0/2.0 to 97.0/3.0.
• the thickness of the first resin layer is not particularly limited and can be determined as appropriate considering the performance and productivity required for the first resin layer, but specifically, it is preferably 0.5 to 30 ⁇ m.
• the thickness is preferably 1 to 20 ⁇ m, more preferably 2 to 15 ⁇ m. By having such a thickness, the performance of the first resin layer can be fully exhibited. Moreover, production costs can be suppressed, and handling and molding of the laminate can be made relatively easy.
• extrusion lamination or thermal lamination may be used, but a water-based coating liquid in which a resin component containing at least P3HB and PVA is dissolved or dispersed in liquid such as water, It is preferable to use a method (hereinafter sometimes referred to as a "coating method") of coating the surface of a paper base material, heating and drying it.
• a coating method a method of coating the surface of a paper base material, heating and drying it.
• a portion of the coating liquid soaks into the paper base layer, so that the paper base layer and the first resin layer are It is preferable to use a coating method because it is easier to improve the binding property.
• the water-based coating liquid can be prepared, for example, with reference to International Publication No. 2021/075412.
• the method for applying the water-based coating liquid to the paper base material is not particularly limited, and any known method that can form a resin layer on the base material can be used as appropriate. Specifically, a spraying method, a scattering method, a slit coater method, an air knife coater method, a roll coater method, a bar coater method, a comma coater method, a blade coater method, a screen printing method, a gravure printing method, etc. can be used. . Before applying the aqueous coating liquid, the paper base material may be subjected to a surface treatment such as corona treatment.
• a surface treatment such as corona treatment.
• the drying treatment after coating it is preferable to form a film by heating at a temperature at which the resin components contained in the first resin layer, particularly P3HB, which is the main resin component, can be melted.
• P3HB the resin components contained in the first resin layer
• the P3HB in the first resin layer is once melted and then cooled and solidified, thereby smoothing the first resin layer surface (the surface not facing the paper base layer) and making the paper
• the binding properties between the base material layer and the first resin layer can be further improved, and the heat sealability or lamination properties can be further improved.
• heating time in the drying treatment after coating is not particularly limited and can be set as appropriate, but may be, for example, 10 seconds to 10 minutes, preferably about 30 seconds to 5 minutes.
• the surface of the first resin layer (the surface not facing the paper base layer) whose smoothness has been increased by the drying treatment after coating can exhibit high gloss.
• the surface of the first resin layer has a glossiness of 5% or more when measured at an incident angle of 60° in accordance with the "Specular Glossiness - Measuring Method" specified in JIS Z 8741:1997. It is preferable that In a laminate including the first resin layer exhibiting such glossiness, the binding properties between the paper base layer and the first resin layer are further improved, and the heat sealability or lamination properties can be further improved. .
• the numerical value of the glossiness is preferably 7% or more, more preferably 8% or more, even more preferably 9% or more, and particularly preferably 10% or more.
• the upper limit is not particularly limited, but may be, for example, 20% or less, or 15% or less. Note that if the heating temperature in the drying treatment after coating is not high enough, the gloss value of the surface of the first resin layer is usually less than 5%.
• the coating amount of the first resin layer is not particularly limited and can be determined as appropriate considering the performance and productivity required for the first resin layer, but specifically, it was measured according to JIS P 8124.
• the basis weight of the first resin layer is preferably 1 to 30 g/m 2 , more preferably 2 to 20 g/m 2 , even more preferably 3 to 15 g/m 2 . When the basis weight is within such a range, the performance of the first resin layer can be fully exhibited. Moreover, production costs can be suppressed, and handling and molding of the laminate can be made relatively easy.
• the first resin layer may constitute the outermost layer.
• the first resin layer can function as a heat-sealing layer, a water-resistant layer, and/or an oil-resistant layer, etc.
• the thickness of the first resin layer may be 0.5 to 30 ⁇ m as described above, preferably 3 to 25 ⁇ m, and more preferably 5 to 20 ⁇ m.
• the heat-sealing layer is a layer having heat-sealability, and specifically, a layer that can be bonded to an object to be bonded by heat-pressure bonding.
• the object to be bonded may be the same heat seal layer, a paper base layer, or an article made of another material.
• good heat sealability can be achieved even when the heating temperature during heat sealing is relatively low.
• Such heating temperature is not limited, but may be, for example, about 110 to 160°C, preferably 120 to 150°C, and more preferably 125 to 140°C.
• the water-resistant layer is contacted using 90°C hot water in accordance with "Paper and Board - Water Absorption Test Method - Cobb Method” specified in JIS P 8140:1998. It refers to a layer whose water absorption (Cobb value) measured at a time of 1800 seconds is 20 g/m 2 or less. Since the first resin layer exhibits long-term water resistance against hot water in this way, it becomes possible to use the laminate according to the present disclosure by forming it into a paper container such as paper tableware.
• the water absorption is preferably 10 g/m 2 or less, more preferably 5 g/m 2 or less.
• the oil-resistant layer is JAPAN TAPPI No. Refers to a layer where the average value of the kit number measured at any five points on the surface of the layer is 10 or more in accordance with the "Paper and Paperboard - Oil Repellency Test Method - Kit Method" specified in 41:2000. .
• the average value of this kit number is preferably 11 or more, and more preferably 12.
• the first resin layer functions as an anchor coat layer between the paper base material layer and the second resin layer, and since the binding property between the paper base material layer and the first resin layer is good, the first resin layer The lamination properties (laminate strength) between the layer and the second resin layer can also be improved. Further, by providing the second resin layer, it is possible to impart high levels of water resistance and oil resistance to the laminate. In this embodiment, the first resin layer only needs to have adhesive performance between the paper base layer and the second resin layer.
• the thickness of the first resin layer may be 0.5 to 30 ⁇ m as described above, preferably 0.7 to 15 ⁇ m, and more preferably 1 to 10 ⁇ m.
• the second resin layer may be the outermost layer in the laminate, or another layer may be laminated on the second resin layer.
• the second resin layer preferably contains a biodegradable resin and exhibits biodegradability. Thereby, the biodegradability of the entire laminate can be improved.
• Usable biodegradable resins include the resins mentioned above for the first resin layer, specifically P3HB, as well as aliphatic polyester resins, aliphatic aromatic polyester resins, and the like.
• the second resin layer preferably contains at least P3HB from the viewpoint of affinity with the first resin layer. This can further improve the adhesiveness between the first resin layer and the second resin layer.
• the second resin layer does not need to contain the above-mentioned PVA.
• the second resin layer preferably contains P3HB in an amount of 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, and even more preferably 90% by weight or more. It may be 95% by weight or more.
• the resin component contained in the second resin layer may be only P3HB, or may further contain another resin. As the other resin, the above-mentioned biodegradable resin can be used.
• P3HB that can be used in the second resin layer are the same as the P3HB that can be used in the first resin layer, so detailed description will be omitted.
• P3HB that can be used in the second resin layer preferably includes a copolymer containing 3-hydroxybutyrate units and other hydroxyalkanoate units, and PHBH is particularly preferred.
• the second resin layer preferably contains PHBH in an amount of 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, and even more preferably 90% by weight or more. It may be 95% by weight or more.
• the resin component contained in the second resin layer may be only PHBH, or may further contain another resin.
• the amount of the lubricant in the second resin layer is preferably 0.1 to 2 parts by weight, and 0.2 to 1 part by weight based on 100 parts by weight of the total amount of resin components contained in the second resin layer. More preferred.
• the blending amount is 0.1 parts by weight or more, it is possible to obtain an effect of improving peelability due to the blending of the lubricant.
• the blending amount is 2 parts by weight or less, the problem of the lubricant bleeding during pressure bonding and adhering to the pressure bonding surface of the cooling roll or the like is suppressed, and continuous processing can be performed for a long time.
• examples of the inorganic filler include talc, calcium carbonate, mica, silica, clay, kaolin, titanium oxide, alumina, and zeolite.
• the average particle diameter of these inorganic fillers is preferably 0.5 ⁇ m or more.
• the thickness of the second resin layer is not particularly limited, and can be determined appropriately taking into consideration the performance and productivity required for the second resin layer.
• the thickness is preferably 20 to 60 ⁇ m, more preferably 20 to 60 ⁇ m. It is preferable that the second resin layer is thicker than the first resin layer.
• the coating method described above may be used as a method for forming the second resin layer on the first resin layer.
• productivity productivity, or suppression of thermal deterioration, it is not possible to form the second resin layer on the surface of the first resin layer by extrusion lamination or thermal lamination. preferable.
• a general thermal lamination method can be used. Specifically, first, a molten resin material is extruded from, for example, a T-shaped die, and a molded film containing the resin material is obtained while being cooled using a cooling roll. Next, a three-layer laminate can be manufactured by pressing the obtained formed film onto the surface of the laminate on the first resin layer side using a hot roll or the like.
• the molded body containing it can be used as various packaging container materials such as shopping bags, various bag making materials, food/confectionery packaging materials, cups, trays, cartons, etc. (in other words, , food, cosmetics, electronics, medical care, pharmaceuticals, etc.). Because this laminate contains a resin that has high adhesion to substrates and good heat resistance, it is suitable for use in containers containing liquids, especially instant noodles, instant soups, coffee and other food/beverage cups, side dishes, bento boxes, and electronic containers. It is more preferable as a container for storing warm contents, such as a tray used for microwave foods.
• the heat-sealing temperature of this laminate differs depending on the adhesion method, but for example, when using a heated heat-sealing tester with a seal bar, the heat-sealing temperature of this laminate is usually determined by the first resin layer or the second resin layer.
• the surface temperature of the resin layer can be set to be 180°C or less, preferably 170°C or less, more preferably 160°C or less. Within the above range, melting of the resin near the sealing portion can be avoided, and an appropriate thickness of the resin layer and sealing strength can be ensured. Since this laminate can achieve good adhesion even when heat-sealed at a low temperature, the surface temperature may be 150°C or lower or 140°C or lower.
• the present molded body is made of a material different from the present molded body (e.g., fiber, thread, rope, woven fabric, knitted fabric, nonwoven fabric, paper, film, sheet, tube, etc.). , plates, rods, containers, bags, parts, foams, etc.). Preferably, these materials are also biodegradable.
• [Item 6] further comprising a second resin layer provided on the first resin layer, The laminate according to any one of items 1 to 5, wherein the second resin layer contains a poly(3-hydroxybutyrate) resin.
• [Item 7] The laminate according to any one of items 1 to 6, which is used as a packaging material.
• [Item 8] The laminate according to any one of items 1 to 6, which is for paper containers.
• [Item 9] A molded article comprising the laminate according to any one of items 1 to 8.
• [Item 12] The manufacturing method according to item 10 or 11, wherein the drying is performed by heating to a temperature of 130 to 180°C.
• [Item 13] Further comprising the step of forming a second resin layer on the first resin layer, The manufacturing method according to any one of items 10 to 12, wherein the second resin layer contains a poly(3-hydroxybutyrate)-based resin.
• the second resin layer is formed by an extrusion lamination method or a thermal lamination method.
• ⁇ The average value of water absorption (Cobb value) exceeds 5 g/m 2 and is 10 g/m 2 or less.
• ⁇ Average value of water absorption (Cobb value) exceeds 10 g/m 2 and is below 20 g/m 2 .
• ⁇ Average value of water absorption (Cobb value) exceeds 20 g/m 2 .
• the kit number was measured at five arbitrary points on the surface of the coating layer or laminate layer in accordance with the "Paper and paperboard - Oil repellency test method - Kit method" specified in 41:2000. The average value of the five measured kit numbers was adopted as the oil resistance value, and the oil resistance was evaluated based on the following criteria. If the evaluation is ⁇ , ⁇ , or ⁇ , it can be determined that there is no problem in practical use. [Evaluation criteria] ⁇ : The average value of the kit number is 12. ⁇ : The average value of the kit number is 11 or more and less than 12. ⁇ : The average value of the kit numbers is 10 or more and less than 11. ⁇ : The average value of kit numbers is less than 10.
• Cellophane tape (width 25 mm) was pasted on the surface of the coating layer, and a rubber roller with a width of 130 mm and a weight of 1.8 kg was made to reciprocate 5 times using its own weight on the cellophane tape to adhere the cellophane tape to the surface of the coating layer. .
• paste-like bacterial cells were separated from the culture solution by centrifugation (5000 rpm, 10 min). Water was added to the bacterial cells to make a suspension of 75 g dry bacterial cells/L, and aqueous sodium hydroxide solution was added as an alkali to maintain the pH at 11.7 while stirring and physically crushing the cells to eliminate bacteria other than PHBH. Body constituent substances were solubilized and centrifuged (3000 rpm, 10 min) to obtain a precipitate. Further, the precipitate was washed with water, and PHBH having a weight average molecular weight of about 260,000, a 3HH mole fraction of 11%, and a purity of 91% was separated to obtain a suspension containing 75 g/L of PHBH.
• the suspension was placed in a stirring tank equipped with a pH electrode and kept at 70°C.
• the pH electrode is connected to a lab controller MDL-6C model manufactured by Marubishi Bioengine, and when the pH drops below the set value, the peristaltic pump is activated and the sodium hydroxide aqueous solution enters the suspension until the set value is reached.
• the pH of the lab controller was set to 10, and 30% hydrogen peroxide was added to the suspension so that the hydrogen peroxide concentration was 5% by weight based on the weight of the polymer (0.375% by weight based on the weight of the suspension). The mixture was added and stirred for 1 hour. Next, this suspension was washed twice with water by centrifugation, and further washed twice with methanol.
• Example 1 (Preparation of coating liquid 1 for coating layer) An adhesive (polyvinyl alcohol, manufactured by Kuraray Co., Ltd.: L-10, degree of saponification 71.5-73.5 mol%) was added to the PHBH aqueous suspension (A) at a solid content weight ratio of 98.0/2.0. Then, water was added and stirred to prepare a coating liquid 1 for coating layer having a solid content concentration of 40% by weight, which is a combination of PHBH and adhesive.
• An adhesive polyvinyl alcohol, manufactured by Kuraray Co., Ltd.: L-10, degree of saponification 71.5-73.5 mol% was added to the PHBH aqueous suspension (A) at a solid content weight ratio of 98.0/2.0. Then, water was added and stirred to prepare a coating liquid 1 for coating layer having a solid content concentration of 40% by weight, which is a combination of PHBH and adhesive.
• Coating liquid 1 for coating layer was coated on one side of a paper base material (single-glazed paper with a basis weight of 50 g/m 2 ) using a bar coater method so that the dry weight was 10.0 g/m 2 (thickness: 8 ⁇ m). Coated paper was obtained by drying at a drying temperature of 160° C. for 2 minutes.
• Example 2 A coated paper was obtained in the same manner as in Example 1, except that the solid content weight ratio of the PHBH aqueous dispersion and the adhesive in Coating Liquid 1 for Coating Layer was changed to 95.0/5.0.
• Example 3 A coated paper was obtained in the same manner as in Example 1, except that the solid content weight ratio of the PHBH aqueous dispersion and the adhesive in Coating Liquid 1 for Coating Layer was changed to 99.5/0.5.
• Example 4 (Preparation of coating liquid 2 for coating layer) An adhesive (polyvinyl alcohol, manufactured by Kuraray Co., Ltd.: 5-74, degree of saponification 72.5-74.5 mol%) was added to the PHBH aqueous suspension (A) at a solid content weight ratio of 98.0/2.0. Then, water was added and stirred to prepare a coating liquid 2 for coating layer having a solid content concentration of 40% by weight, which is a combination of PHBH and adhesive. (Preparation of coated paper) A coated paper was obtained in the same manner as in Example 1, except that Coating Liquid 1 for Coating Layer was changed to Coating Liquid 2 for Coating Layer.
• Example 5 A coated paper was obtained in the same manner as in Example 4, except that the solid content weight ratio of the PHBH aqueous dispersion and the adhesive in the coating liquid 2 for coating layer was changed to 95.0/5.0.
• Example 7 A coated paper was obtained in the same manner as in Example 6, except that the solid content weight ratio of the PHBH aqueous dispersion and the adhesive in Coating Solution 3 for Coating Layer was changed to 95.0/5.0.
• the coated papers of Examples 1 to 7 have a coating layer containing P3HB and PVA that satisfies a specific degree of saponification in a specific ratio, and have good water resistance. It can be seen that the adhesiveness between the paper base material and the paper base material is high, and the heat sealability is good. On the other hand, in the coated paper of Comparative Example 1, the coating layer did not contain PVA, the binding between the coating layer and the paper base material was low, and the heat sealability was also insufficient. In the coated paper of Comparative Example 2, although the coating layer contained PVA that satisfied a specific degree of saponification, the content ratio was high, and the water resistance was insufficient. Moreover, the biodegradability of the coating layer was also reduced due to the high content ratio of PVA. In the coated paper of Comparative Example 3, the PVA contained in the coating layer did not satisfy a specific degree of saponification, the binding between the coating layer and the paper base material was somewhat low, and the heat sealability was poor. That was enough.
• Example 8 (Preparation of laminate by extrusion lamination method) The paper base material was changed to kraft paper with a basis weight of 200 g/ m2 , the solid content concentration of coating liquid 1 for the coating layer was changed to 25% by weight, and the coating amount of coating liquid 1 for the coating layer was changed to dry weight. A coated paper with a first resin layer was obtained in the same manner as in Example 1 except that the basis weight was changed to 3.0 g/m 2 (thickness 2.5 ⁇ m).
• PHBH powder PHBH powder with a weight average molecular weight of 650,000 and a composition ratio of 3-hydroxybutyrate units/3-hydroxyhexanoate units of 85/15 (mol/mol)) (100 parts by weight), behenic acid amide (0.2 parts by weight), and pentaerythritol (1.0 parts by weight) were dry-blended using a twin-screw extruder at a set temperature of 150°C and a screw rotation speed of 100 rpm. The mixture was melt-kneaded and extruded into strands, solidified by passing through hot water at 40°C, and cut into pellets.
• Example 9 A laminated paper was obtained in the same manner as in Example 8, except that the solid content weight ratio of the PHBH aqueous dispersion and the adhesive in Coating Solution 1 for Coating Layer was changed to 95.0/5.0.
• Example 11 A laminated paper was obtained in the same manner as in Example 8, except that Coating Liquid 3 for coating layer was used in place of Coating Liquid 1 for Coating Layer.
• Example 13 Manufacture of laminate by thermal lamination method
• a coated paper with a first resin layer was obtained in the same manner as in Example 8.
• behenic acid amide 0.2 parts by weight
• pentaerythritol 1.0 parts by weight
• the mixture was blended, melt-kneaded using a twin-screw extruder at a set temperature of 150°C and a screw rotation speed of 100 rpm, extruded into a strand, passed through hot water at 40°C to solidify, and cut into pellets.
• the obtained pellets were taken by a cooling roll set at 60° C.
• Example 5 A laminated paper was obtained in the same manner as in Example 8, except that Coating Liquid 5 for coating layer was used in place of Coating Liquid 1 for Coating Layer.
• the first resin layer contains a specific ratio of PVA that satisfies a specific degree of saponification. , it can be seen that the lamination properties are good.
• the first resin layer did not contain PVA, and the lamination properties were insufficient.
• the PVA contained in the first resin layer did not satisfy a specific degree of saponification, and the lamination properties were insufficient.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)
• Wrappers (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=89191118

Family Applications (1)

Country Status (5)

Cited By (5)

Citations (7)

Family Cites Families (1)

• 2023
  • 2023-05-19 CN CN202380043693.XA patent/CN119278129A/zh active Pending
  • 2023-05-19 JP JP2024528410A patent/JPWO2023243309A1/ja active Pending
  • 2023-05-19 EP EP23823610.3A patent/EP4541585A1/en active Pending
  • 2023-05-19 WO PCT/JP2023/018832 patent/WO2023243309A1/ja not_active Ceased
• 2024
  • 2024-12-11 US US18/976,445 patent/US20250100256A1/en active Pending

Patent Citations (7)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events