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
  • 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 has water resistance, oil resistance, and heat seal suitability, which are suitably used for packaging materials such as water- and oil-resistant heat-sealed papers, especially food packaging materials, bags, containers, boxes, cups, and lid materials. Regarding water-resistant and oil-resistant heat-sealed paper that can be stored for a long time.
• 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.).
• coated paper is rolled up and stored at room temperature until the paper packaging material is molded into food packaging materials, bags, containers, boxes, cups, lid materials, etc.
• blocking occurs during long-term storage. Therefore, it is necessary to provide a wrapping paper having both good blocking resistance and heat seal suitability.
• pinholes may occur during coating, and especially for wrapping paper that requires water resistance and oil resistance, sufficient water resistance and oil resistance may not be obtained due to these pinholes. It is desirable that the wrapping paper has good pinhole resistance.
• the present invention has water resistance, oil resistance, heat seal suitability, and water resistance and oil resistance that can be stored for a long period of time, which are particularly suitable for packaging materials such as food packaging materials, bags, containers, boxes, cups, and lid materials. It is intended to provide heat-sealed paper.
• a water- and oil-resistant heat-sealed paper comprising a coating layer containing a thermoplastic resin, a wax, and a pigment on at least one surface of a paper substrate.
• the coating layer contains 3 parts by mass or more of wax and 15 parts by mass or less of pigment with respect to 100 parts by mass of the thermoplastic resin.
• 3. The wax contained in the coating layer is carnauba wax. Or 2.
• the coating layer contains a thermoplastic resin having a glass transition temperature of 100 ° C. or lower. ⁇ 3.
• the water and oil resistant heat seal paper according to any one of the above. 5. 1.
• thermoplastic resin contained in the coating layer is an ethylene acrylic acid copolymer resin.
• the pigment contained in the coating layer is an inorganic flat pigment.
• the present invention it is possible to provide a water-resistant and oil-resistant heat-sealed paper having heat-sealing suitability and capable of long-term storage.
• the water- and oil-resistant heat-sealed paper of the present invention has excellent pinhole resistance, and is also excellent in water resistance and oil resistance.
• the water- and oil-resistant heat-sealed paper of the present invention can be suitably used for packaging materials such as foods, bags, containers, boxes, cups, and lid materials.
• the present invention relates to a water- and oil-resistant heat-sealed paper (hereinafter, also referred to as heat-sealed paper), which comprises a coating layer containing a thermoplastic resin, a wax, and a pigment on at least one surface of a paper base material. ..
• 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 ground pulp
• SGP Stone ground pulp
• CGP Chemigrand pulp
• SCP Semi-chemical pulp
• TMP Chemithermomechanical 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.
• 20 g / m 2 or more and 600 g / m 2 or less are preferable.
• 25 g / m 2 or more and 600 g / m 2 or less are more preferable, especially bags and lids.
• 30 g / m 2 or more and 150 g / m 2 or less is used, and in the case of heat-sealed paper used for containers, boxes, and cups, 150 g.
• 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 heat-sealed paper of the present invention has a coating layer containing a thermoplastic resin, a wax, and a pigment on at least one surface of a paper base material.
• the coating layer is a layer that imparts heat-sealing suitability, and specifically, is a layer that 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 sealing, 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 wax used in the present invention 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, and a silicone-containing wax containing silicone or a silicone compound.
• a fluorine-containing wax containing a fluorine compound or the like 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 not particularly limited, but it is preferable that the wax is contained in an amount of 3 parts by mass or more, and more preferably 4 parts by mass or more, based on 100 parts by mass of the thermoplastic resin by dry weight. preferable. If the blending amount of the wax is less than 3 parts by mass, sufficient blocking resistance may not be obtained. Further, it is preferable that the wax is contained in an amount of 15 parts by mass or less, and more preferably 12 parts by mass or less, based on 100 parts by mass of the thermoplastic resin by dry weight. Even if the blending amount of the wax exceeds 15 parts by mass, the blocking resistance is saturated and hardly improved, and the cost increases.
• the pigments used in the present invention are not particularly limited, and are limited to kaolin, clay, engineered kaolin, delaminated clay, heavy calcium carbonate, light calcium carbonate, mica, talc, titanium dioxide, barium sulfate, calcium sulfate, etc.
• Inorganic pigments such as zinc oxide, silicic acid, silicate, colloidal silica, and satin white, and organic pigments such as solid type, hollow type, and core-shell type can be used. Further, the pigment may be used alone or in combination of two or more. Among these, inorganic flat pigments are preferable from the viewpoint of improving water resistance.
• the flat pigment means a pigment having an aspect ratio of 10 or more.
• the blending amount of the pigment is not particularly limited, but it is preferable that the pigment is contained in an amount of 15 parts by mass or less, more preferably 12 parts by mass or less, based on 100 parts by mass of the thermoplastic resin by dry weight. preferable. If the blending amount of the pigment exceeds 15 parts by mass, sufficient water resistance may not be obtained. Further, it is preferable to contain 0.1 part by mass or more of the pigment with respect to 100 parts by mass of the thermoplastic resin by dry weight, and more preferably 3 parts by mass or more. If the blending amount of the pigment is less than 0.1 parts by mass, the pinhole resistance may decrease.
• the coating layer of the present invention contains a thermoplastic resin, a wax and a pigment.
• Wax prevents the occurrence of blocking, but may cause the occurrence of pinholes.
• the blending ratio of the wax and the pigment is not particularly limited as long as it can achieve both blocking resistance and pinhole resistance, but the mass ratio of the wax: pigment is preferably 10:90 to 80:20. , 20:80 to 70:30, more preferably.
• the heat-sealed paper of the present invention may have a coating layer and a paper base material, and may have other layers such as a sealing layer, a printing layer, a light-shielding layer, a water vapor barrier layer, and a gas barrier layer. It is preferable to have a sealing layer between the coating layer and the paper substrate. (Sealing layer)
• the sealing layer prevents the performance of the coating layer from deteriorating by suppressing the sinking of the coating liquid for the coating layer into 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 sealing layer is not particularly limited as long as it can suppress the sinking of the coating liquid for the coating layer into the paper substrate, but it is preferably contained, for example, a thermoplastic resin and a pigment. Further, the sealing layer may contain a sizing agent, a water resistant agent, a water repellent agent, a dye, a surfactant and the like, if necessary. As the thermoplastic resin and the pigment, known ones used for the sealing layer can be used. The blending amount of the pigment in the sealing layer is not particularly limited as long as it is within the range in which the sealing effect can be exhibited, but for example, the pigment is contained in an amount of 50 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. Is preferable.
• the coating method of the coating layer and the sealing layer is not particularly limited, and coating can be performed by a known coating apparatus 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 1 g / m 2 or more and 20 g / m 2 or less per side. If the coating amount is less than 1 g / m 2 per side, the water resistance, oil resistance, and heat seal suitability deteriorate. Further, even if the coating amount exceeds 20 g / m 2 per side, the water resistance, oil resistance, and heat seal suitability are 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. When the sealing layer is provided, the coating amount (dry weight) is preferably 3 g / m 2 or more and 20 g / m 2 or less.
• the heat-sealed paper of the present invention has the highest water absorption (cobb value) measured at a contact time of 1800 seconds in accordance with "Paper and Paperboard-Water Absorption Test Method-Cobb Method" specified in JIS P8140: 1998. Is preferably 15 g / m 2 or less, and more preferably 5 g / m 2 or less.
• the heat-sealed paper of the present invention is J.I. TAPPI No.
• the minimum value of the kit number measured at any 5 points on the surface of the oil resistant layer shall be 6 or more in accordance with "Paper and Paperboard-Fatility Test Method-Kit Method" specified in 41: 2000. Is preferable, 10 or more is more preferable, and 12 is most preferable.
• the water- and oil-resistant heat-sealed paper of the present invention can be a water- and oil-resistant heat-sealed paper used for packaging materials such as foods, bags, containers, boxes, cups, and lid materials. Among these, it can be suitably used particularly for containers, boxes, cups, and more preferably for beverage cups.
• 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
• Pinhole-resistant dyeing solution containing a surfactant (surfactant) Agent: Tipol Eight 0.2%, Dye: Brilliant Blue 0.05%, Surface tension 28.4 mN / m) was dropped onto any two points on the surface of the coating layer in an amount of 10 ml, and the dyeing solution was wiped off after 10 seconds. After that, it was confirmed whether or not the dropped portion was stained. If the evaluation is A, there is no practical problem. [Evaluation criteria] A: Less than 10 pinhole stains in a 5 cm square B: 10 or more pinhole stains in a 5 cm square
• Example 1 (Preparation of coating liquid for coating layer) Thermoplastic resin (Michelman: MICHEM PRIME 498345NS), carnauba wax (Michelman: MICHEM LUBE 160RPH.S), Kaolin (Imelis: Varisurf HX, aspect ratio 95), respectively, by solid content mass ratio.
• the composition was adjusted to 100.0 / 6.0 / 10.0 parts, and a coating liquid for a coating layer was obtained.
• Thermoplastic resin Michelman: MICHEM PRIME 498345NS
• kaolin Imeris: Varisurf HX
• (Making water and oil resistant heat seal paper) Apply the coating liquid for the sealing layer to one side of the paper base material (cup base paper with a basis weight of 200 g / m 2 ) by the bar blade method so that the coating amount is 8.0 g / m 2 by dry weight and dry. Then, a coating liquid for a coating layer was applied onto the coating layer by a bar blade method so as to have a coating amount of 3.5 g / m 2 by a dry weight, and dried to obtain a water-resistant oil-resistant heat-sealed paper.
• Example 2 Water-resistant and oil-resistant heat-resistant heat in the same manner as in Example 1 except that the solid content mass ratio of the thermoplastic resin, wax, and pigment in the coating liquid for the coating layer was 100.0 / 10.0 / 5.0 parts. I got a sticker paper.
• Example 3 Water-resistant and oil-resistant heat-resistant heat in the same manner as in Example 1 except that the solid content mass ratio of the thermoplastic resin, wax, and pigment in the coating liquid for the coating layer was 100.0 / 10.0 / 10.0 parts. I got a sticker paper.
• a thermoplastic resin (Michelman: MICHEM PRIME 498345NS) is applied to a bar so that the coating amount is 10.0 g / m 2 by dry weight. It was coated and dried by the blade method to obtain a water- and oil-resistant heat-sealed paper.
• Example 1 and Example 1 except that only a thermoplastic resin (Michelman: MICHEM PRIME 489345NS) was applied as a coating liquid for the coating layer so that the coating amount was 5.0 g / m 2 by dry weight.
• the heat-sealed papers obtained in Examples 1 to 3 of the present invention were excellent in blocking resistance. In addition, it was excellent in pinhole resistance, water resistance, and oil resistance.
• the heat-sealed papers obtained in Comparative Examples 3 and 4 in which the coating layer did not contain wax had blocking and were inferior in long-term storage stability. Moreover, it was inferior in water resistance.

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

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• 2020
  • 2020-07-28 JP JP2020127382A patent/JP7247147B2/ja active Active
• 2021
  • 2021-07-19 WO PCT/JP2021/026996 patent/WO2022024845A1/ja not_active Ceased

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