Classifications

• • 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
  • B65D65/42—Applications of coated or impregnated materials
• • 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
  • D21H19/36—Coatings with pigments
• • 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
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/46—Non-macromolecular organic compounds
• • 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
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/56—Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • 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 heat-sealing paper, particularly heat-sealing paper having heat-sealing suitability, which is suitably used for packaging applications such as packaging materials, bags, containers, boxes, cups, and lid materials.
• plastic waste has been taken up as a major problem because there is a concern that plastic that has flowed out into the environment will not be decomposed semi-permanently and will have an adverse effect on the ecosystem.
• plastic which is a biomass-derived material and a biodegradable material.
• a paper packaging material is molded into a packaging material such as food, a bag, a container, a box, a cup, a lid material, etc.
• heat typified by a polyolefin resin such as polyethylene, polypropylene, polymethylpentene, etc. It is generally practiced to laminate a plastic resin on a packaging material by an extrusion laminating method or the like to impart heat seal suitability.
• thermoplastic resin of about 10 to 30 g / m 2
• the reduction in the amount of plastic is not sufficient.
• a wrapping paper in which the laminated coating layer is thinned and reduced in weight is provided by applying water or a solvent dispersion liquid containing a thermoplastic resin dispersion on a paper substrate (patented). Document 1 etc.).
• heat is applied when the paint is dried when laminating the coating layer by coating, and when the paper packaging material is molded into packaging materials such as food, bags, containers, boxes, cups, lid materials, etc. There is a need.
• the thermoplastic resin remains softened
• the coated paper is wound into a roll and stored until it is molded, but there is a problem that blocking occurs during long-term storage at room temperature. Therefore, it is necessary to provide a wrapping paper having both good blocking resistance and heat seal suitability.
• An object of the present invention is to provide a heat-sealing paper having heat-sealing suitability and good blocking resistance, which is suitably used for packaging applications such as packaging materials, bags, containers, boxes, cups, and lid materials.
• the means for solving the problem of the present invention is as follows. 1.
• a coating layer containing a thermoplastic resin is provided on at least one surface of the paper substrate.
• the coating layer contains at least a pigment as an anti-blocking agent and A heat-sealed paper characterized in that the blending amount of the pigment in the coating layer is less than 200 parts by mass with respect to 100 parts by mass of the thermoplastic resin.
• a coating layer containing a thermoplastic resin is provided on at least one surface of the paper substrate.
• the coating layer contains at least wax as an anti-blocking agent and A heat-sealed paper characterized in that the amount of wax blended in the coating layer is 1.2 parts by mass or more with respect to 100 parts by mass of the thermoplastic resin. 3.
• the coating layer contains a thermoplastic resin having a glass transition temperature of 100 ° C. or lower. ⁇ 3. The heat seal paper according to any one of the above. 5. The coating layer is characterized by containing carnauba wax. ⁇ 4. The heat seal paper according to any one of the above. 6. 1. The thermoplastic resin contained in the coating layer is an ethylene acrylic acid copolymer resin. ⁇ 5. The heat seal paper according to any one of the above.
• a heat-sealed paper having heat-sealing suitability and good blocking resistance, which is suitably used for packaging applications.
• a pigment and a wax in combination as an anti-blocking agent, it is possible to impart the necessary blocking resistance depending on the situation.
• the present invention is a heat-sealed paper having a coating layer containing a thermoplastic resin on at least one surface of a paper substrate, wherein the coating layer is one or more anti-blocking agents selected from wax or pigment.
• the present invention relates to a heat-sealing paper comprising the above and characterized in that the coating layer has heat-sealing suitability.
• the paper base material is obtained by papermaking a paper material containing pulp, a filler, various auxiliaries and the like.
• the heat-sealed paper of the present invention is used for applications in contact with food, it is suitable for food safety, such as being approved as a food additive or having FDA certification as each material of the paper base material. It is preferable to use.
• NNKP bleached kraft pulp
• NUKP bleached kraft pulp
• LLKP bleached kraft pulp of broadleaf tree
• LLKP unbleached kraft pulp
• SP sulphite pulp
• GP Grand Pulp
• RGP Refiner Grand Pulp
• SGP Stone Grand Pulp
• CGP Chemi Grand Pulp
• SCP Semi-Chemical Pulp
• TMP Chemi Thermomechanical Pulp
• Known pulp such as mechanical pulp of wood such as, non-wood pulp obtained from Kenaf, Bagus, bamboo, hemp, straw, etc., waste paper pulp from which ink contained in waste paper is removed in the deinking process using waste paper as a raw material. Can be appropriately blended and used.
• chemical pulps such as LBKP and NBKP, which are less likely to be mixed with foreign substances, are preferable, and the amount of used paper pulp is preferably small.
• the blending amount of the chemical pulp is preferably 80% or more, and the blending amount of the chemical pulp is particularly preferably 100%. Further, the blending amount of the recycled paper pulp is preferably 10% or less, more preferably 1% or less, and most preferably not contained.
• Fillers include talc, kaolin, calcined kaolin, clay, heavy calcium carbonate, light calcium carbonate, white carbon, zeolite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide. , Calcium hydroxide, magnesium hydroxide, zinc hydroxide, barium sulfate, calcium sulfate and other inorganic fillers, urea-formalin resin, polystyrene resin, phenolic resin, organic fillers such as fine hollow particles, etc. Can be done.
• the filler is not an essential material and may not be used.
• auxiliaries examples include rosin, alkyl keten dimer (AKD), alkenyl succinic acid anhydride (ASA) and other sizing agents, polyacrylamide-based polymers, polyvinyl alcohol-based polymers, cationized starch, various modified starches, urea and other agents.
• Dry paper strength enhancer such as formalin resin, melamine / formalin resin, wet paper strength enhancer, retention agent, drainage improver, coagulant, sulfuric acid band, bulking agent, dye, fluorescent whitening agent, pH adjuster, Examples thereof include a defoaming agent, an ultraviolet inhibitor, a fading inhibitor, a pitch control agent, a slime control agent, and the like, and they can be appropriately selected and used as necessary.
• the method for manufacturing (paper making) the paper base material is not particularly limited, and is a long net paper machine, a circular net paper machine, a short net paper machine, a gap former type, a hybrid former type (on-top former type), etc.
• a known manufacturing (paper making) method such as a twin wire paper machine, or a paper machine can be selected.
• the pH at the time of papermaking may be any of an acidic region (acidic papermaking), a pseudo-neutral region (pseudo-neutral papermaking), a neutral region (neutral papermaking), and an alkaline region (alkaline papermaking). Later, an alkaline agent may be applied to the surface of the paper layer.
• the paper base material may be one layer or may be composed of two or more layers.
• the surface of the paper substrate with various chemicals.
• the chemicals used include oxidized starch, hydroxyethyl etherified starch, enzyme-modified starch, polyacrylamide, polyvinyl alcohol, surface sizing agents, water resistant agents, water retaining agents, thickeners, lubricants, and the like. These can be used alone or in combination of two or more.
• these various agents and pigments may be used in combination.
• Pigments include kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide, silicic acid, silicate, colloidal silica, and satin.
• Inorganic pigments such as white and organic pigments such as solid type, hollow type, and core-shell type can be used alone or in combination of two or more.
• the method of surface treatment of the paper substrate is not particularly limited, but a known coating device such as a rod metering size press, a pound type size press, a gate roll coater, a spray coater, a blade coater, and a curtain coater should be used. Can be done.
• the paper base material thus obtained includes high-quality paper, medium-quality paper, coated paper, single-gloss paper, kraft paper, single-gloss kraft paper, bleached kraft paper, glassin paper, paperboard, white paperboard, liner, and the like.
• Various known ones can be exemplified.
• the basis weight of the paper substrate can be appropriately selected depending on the desired quality, handleability, etc., but usually 20 g / m 2 or more and 600 g / m 2 or less are preferable. In the case of heat-sealed paper used for packaging materials such as food packaging materials, bags, containers, boxes, cups, lid materials, etc., 25 g / m 2 or more and 600 g / m 2 or less are more preferable, especially bags and lids.
• the flexible packaging material is a packaging material composed of a highly flexible material, and generally, a thin and flexible material such as paper, film, or aluminum foil is used alone or bonded.
• packaging material refers to packaging material.
• the shape refers to a packaging material that maintains a three-dimensional shape by putting contents such as a bag.
• the density of the paper substrate can be appropriately selected depending on the desired quality, handleability, etc., but is usually preferably 0.5 g / cm 3 or more and 1.0 g / cm 3 or less.
• the coating layer contains a thermoplastic resin and one or more antiblocking agents selected from waxes or pigments.
• the coating layer can be provided on both sides of the heat-sealed paper, but has at least one side.
• the coating layer has heat seal suitability. Having heat seal suitability means that it can be adhered to an object to be bonded by heating and pressurizing. Having heat-sealing suitability makes it easy to mold into a packaging form, maintain its shape, and ensure hermeticity, especially in packaging applications such as food packaging materials, bags, containers, boxes, cups, and lid materials. ..
• thermoplastic resin used in the present invention can be used without particular limitation in the field of papermaking, which is used for forming a heat seal layer.
• the glass transition temperature of the thermoplastic resin is preferably ⁇ 20 ° C. or higher and 85 ° C. or lower.
• the melting point of the thermoplastic resin is preferably 80 ° C. or higher and 120 ° C. or lower.
• the thermoplastic resin include low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), vinyl acetate (PVAc), polyester resin (PEs), and the like.
• Ethylene methacrylate copolymer resin (EMAA), ethylene methyl acrylate copolymer resin (EMA), ethylene acrylic acid copolymer resin (EAA), ethylene vinyl acetate copolymer resin (EVA), styrene acrylic acid ester copolymer resin, polylactic acid Resin or the like can be used.
• the thermoplastic resin can be used alone or in combination of two or more. Among these, an ethylene acrylic acid copolymer resin having high heat seal suitability is preferable.
• the heat-sealed paper of the present invention contains a pigment or wax as an anti-blocking agent. Both pigments and waxes can also be included as anti-blocking agents.
• the pigment used in the present invention is not particularly limited, and is not particularly limited. Kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, zinc oxide. , Inorganic pigments such as calcium sulphate, silicate, colloidal silica, satin white and organic pigments such as solid type, hollow type, or core-shell type can be used. Further, the pigment may be used alone or in combination of two or more. Among these, heavy calcium carbonate is preferable because it has excellent blocking resistance without impairing the heat seal suitability.
• the blending amount of the pigment is more preferably less than 200 parts by mass and 150 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin by dry weight. If the blending amount of the pigment is 200 parts by mass or more, the heat sealing temperature may become too high, or the heat sealing may take a long time. Further, it is preferable to contain 50 parts by mass or more of the pigment, and more preferably 80 parts by mass or more, based on 100 parts by mass of the thermoplastic resin by dry weight. If the blending amount of the pigment is less than 50 parts by mass, the blocking resistance may be insufficient.
• the wax used in the present invention is not particularly limited, and is not particularly limited, and is a paraffin wax mainly composed of an alkane compound, a natural oil-based wax derived from animals and plants such as carnauba and lanolin, a silicone-containing wax containing a silicone or a silicone compound, and a fluorine compound.
• a fluorine-containing wax containing the above can be used.
• the wax may be used alone or in admixture of two or more. Of these, carnauba wax is preferred.
• the blending amount of the wax is 1.2 parts by mass or more, preferably 1.5 parts by mass or more, and 2.5 parts by mass or more with respect to 100 parts by mass of the thermoplastic resin by dry weight. Is more preferable. If the blending amount of the wax is less than 1.2 parts by mass, sufficient blocking resistance may not be obtained. Further, it is preferable to contain 15 parts by mass or less of wax with respect to 100 parts by mass of the thermoplastic resin by dry weight, and more preferably 10 parts by mass or less. Even if the blending amount of the wax exceeds 15 parts by mass, the blocking resistance is hardly improved and the cost increases.
• Pigments and waxes are both anti-blocking agents, but while pigments contribute mainly to blocking resistance in hot conditions such as during processing, wax mainly contributes to blocking resistance during long-term storage. Contribute.
• a pigment and a wax in combination as an anti-blocking agent, it is possible to impart the necessary blocking resistance depending on the situation.
• the blending ratio of the pigment and the wax can be adjusted according to the situation where blocking resistance is required.
• the dry weight of the pigment is 1 part by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the pigment. be able to.
• the coating method of the coating layer is not particularly limited, and coating can be performed by a known coating device and coating system.
• the coating device include a blade coater, a bar coater, an air knife coater, a curtain coater, a spray coater, a roll coater, a reverse roll coater, a size press coater, a gate roll coater, and the like.
• examples of the coating system include water-based coating using a solvent such as water, solvent-based coating using a solvent such as an organic solvent, and the like. Since the heat-sealed paper of the present invention may be used for applications in contact with foods and the like, water-based coating is preferable from the viewpoint of food safety.
• the viscosity, solid content concentration, etc. of the coating liquid can be appropriately adjusted according to the coating apparatus, coating system, and the like to be used.
• the coating amount (dry weight) of the coating layer is preferably 3 g / m 2 or more and 20 g / m 2 or less per side. If the coating amount is less than 3 g / m 2 per side, the heat seal suitability is lowered. Further, even if the coating amount exceeds 20 g / m 2 per side, the heat seal suitability is hardly improved and the cost increases.
• the coating layer may be one layer or may be composed of two or more layers. When the coating layer is composed of two or more layers, it is preferable that the total coating amount of all the coating layers is within the above range.
• the heat-sealed paper of the present invention may have a coating layer and a paper base material, and may be other than a sealing layer, a printing layer, a light-shielding layer, a water-resistant layer, an oil-resistant layer, a water vapor barrier layer, a gas barrier layer, and the like. It is possible to have a layer, and it is preferable to have a sealing layer between the coating layer and the paper substrate. By having the sealing layer, it is possible to reduce the occurrence of coating defects such as pinholes and streaks in the coating layer, and it is possible to improve water resistance and oil resistance.
• the heat-sealed paper of the present invention can be a heat-sealed paper used for packaging materials such as foods, bags, containers, boxes, cups, and lid materials.
• Heat seal suitability (heat seal conditions) Two square test pieces having a side of 100 mm are cut out from the obtained heat - sealed paper, and the coating layers are brought into contact with each other. Heat-sealed with. When the heat-sealed test piece was peeled off by hand, the peeled part was visually observed, and the heat-sealing suitability was evaluated according to the following criteria. A: Peeling in the paper base material (paper base material is destroyed) B: Peeling between coating layers
• Blocking property A This evaluation assumes storage of products in warehouses, etc. The degree of blocking was evaluated by contacting the coating layers with each other by ASTM D918-81, Standard Test Method for Blocking Response of Paper and Paperboard, and storing at 60 ° C. and RH 75% for 24 hours. If the evaluation is A or B, there is no practical problem. [Evaluation criteria] A: No blocking B: There is mild blocking and can be easily peeled off. C: Strongly blocked and cannot be easily peeled off.
• Blocking property B This evaluation assumes sticking when a heated coating layer comes into contact with each equipment during manufacturing or processing of a product.
• a humidity-controlled sample (23 ° C., RH 50%) is passed through a thermal roll press (roll pressure 0.5 MPa, processing speed 2 m / min, arbitrary roll temperature) so that the coated surface and the metal roll come into contact with each other. The degree of sticking of the coated surface to the metal roll was evaluated. If the evaluation is A or B, there is no practical problem. [Evaluation criteria] A: No sticking is seen and no damage is seen on the coated surface when the roll temperature is 70 ° C. B: No sticking is seen and no damage is seen on the coated surface when the roll temperature is 60 ° C. C: When the roll temperature is 60 ° C., the coating layer adheres to the metal roll, and the coating layer is removed from the metal roll, resulting in damage to the coated surface.
• Example 1 Preparation of coating liquid for coating layer
• Thermoplastic resin Michelman: MICHEM PRIME 498345NS
• kaolin Imeris: Varisurf HX, aspect ratio 95
• Example 2 A heat-sealed paper was obtained in the same manner as in Example 1 except that the pigment was heavy calcium carbonate (FMT-100, manufactured by Fimatec Limited).
• Example 3 A heat-sealed paper was obtained in the same manner as in Example 1 except that the pigment was light calcium carbonate (TunexE, manufactured by New Lime Co., Ltd.).
• the coating liquid for the coating layer is 100.0 / 2 in terms of solid content mass ratio of thermoplastic resin (Michelman: MICHEM PRIME 498345NS) and carnauba wax (Michelman: MICHEM LUBE 160RPH.S).
• a heat-sealed paper was obtained in the same manner as in Example 1 except that it was prepared to have 9 parts.
• Example 5 A heat-sealed paper was obtained in the same manner as in Example 4 except that the solid content mass ratio of the thermoplastic resin and the wax was 100.0 / 6.1 parts.
• the coating liquid for the coating layer is a solid content of thermoplastic resin (Michelman: MICHEM PRIME 498345NS), kaolin (Imelis: Varisurf HX), and carnauba wax (Michelman: MICHEM LUBE 160RPH.S).
• Heat-sealed paper was obtained in the same manner as in Example 1 except that the mass ratio was adjusted to be 100.0 / 100.0 / 2.9 parts, respectively.
• Example 1 A heat-sealed paper was obtained in the same manner as in Example 1 except that a coating liquid for a coating layer containing only a thermoplastic resin (Michelman: MICHEM PRIME 489345NS) was used.
• a coating liquid for a coating layer containing only a thermoplastic resin Michelman: MICHEM PRIME 489345NS
• the heat-sealed papers obtained in Examples 1 to 6 of the present invention were excellent in blocking resistance.
• the heat-sealed papers obtained in Examples 1 to 3 containing a pigment as an anti-blocking agent are excellent in operational suitability, and the heat-sealed papers obtained in Examples 4 and 5 containing wax as an anti-blocking agent are particularly long-term storage. It was excellent in sex. Further, the heat-sealed paper obtained in Example 6 containing both a pigment and a wax as an anti-blocking agent was excellent in both long-term storage and operational suitability.
• the heat-sealed paper obtained in Comparative Example 1 containing no anti-blocking agent and the heat-sealed paper obtained in Comparative Example 3 in which the amount of wax as an anti-blocking agent was small were inferior in blocking resistance.
• the heat-sealed paper obtained in Comparative Example 2 in which the amount of the pigment as an anti-blocking agent was large was excellent in blocking resistance, but was inferior in heat-sealing suitability in the first place.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Paper (AREA)
• Wrappers (AREA)
• Laminated Bodies (AREA)
• Dispersion Chemistry (AREA)

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• 2020
  • 2020-07-28 JP JP2020127383A patent/JP7185666B2/ja active Active
• 2021
  • 2021-07-19 WO PCT/JP2021/026997 patent/WO2022024846A1/ja not_active Ceased
  • 2021-07-19 KR KR1020237002952A patent/KR20230043850A/ko active Pending
• 2022
  • 2022-11-24 JP JP2022187274A patent/JP7584157B2/ja active Active

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