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JP-2026075204-A - Oil-resistant paper and method for manufacturing the same

JP2026075204AJP 2026075204 AJP2026075204 AJP 2026075204AJP-2026075204-A

Abstract

[Problem] The purpose of this disclosure is to provide an oil-resistant paper and a method for manufacturing the same, which have low air permeability and excellent oil resistance, while keeping the amount of oil-resistant layer adhesion to a small amount without using a fluorine-based oil repellent. [Solution] The oil-resistant paper according to the present disclosure is an oil-resistant paper having an oil-resistant layer on one or both sides of a paper substrate, wherein the oil-resistant layer contains 50% by mass or more of hydrophobic starch, 3 to 47% by mass of at least one metal salt selected from the group consisting of magnesium sulfate, magnesium chloride, and calcium chloride, and 3 to 47% by mass of cationic polyacrylamide, with the amount of the oil-resistant layer adhering to the paper substrate being 1.0 to 5.0 g/ m² in terms of solid content per side when the oil-resistant layer is provided on both sides of the paper substrate, and the amount of the oil-resistant layer adhering to the paper substrate being 0.5 to 2.5 g/ m² in terms of solid content when the oil-resistant layer is provided on only one side of the paper substrate. [Selection Diagram] None

Inventors

  • 松井 くるみ
  • 山本 弘之
  • 藤田 敏宏
  • 坂爪 信之
  • 米山 菜穂子
  • 高橋 淳一

Assignees

  • 北越コーポレーション株式会社

Dates

Publication Date
20260508
Application Date
20241022

Claims (18)

  1. Oil-resistant paper having an oil-resistant layer on one or both sides of a paper base material, The oil-resistant layer contains 50% by mass or more of hydrophobic starch, 3 to 47% by mass of at least one metal salt selected from the group consisting of magnesium sulfate, magnesium chloride, and calcium chloride, and 3 to 47% by mass of cationic polyacrylamide, based on 100% by mass of the solid content of the oil-resistant layer, When the oil-resistant layer is provided on both sides of the paper substrate, the amount of oil-resistant layer adhering to the surface is 1.0 to 5.0 g/ m² in terms of solid content per side. Oil-resistant paper characterized in that, when the oil-resistant layer is provided on only one side of the paper substrate, the amount of oil-resistant layer adhering to it is 0.5 to 2.5 g/ m² in terms of solid content.
  2. The oil-resistant paper according to claim 1, characterized in that the hydrophobized starch is starch hydrophobized with alkenyl succinic acid.
  3. The oil-resistant paper according to claim 1, characterized in that the hydrophobized starch is starch hydrophobized with octenyl succinic acid.
  4. The oil-resistant paper according to claim 1, characterized in that the weight-average molecular weight of the cationic polyacrylamide is 100,000 to 6,000,000.
  5. The oil-resistant paper according to claim 1, characterized in that the degree of cationization of the cationic polyacrylamide is 0.5 to 10 meq/g.
  6. The oil-resistant layer further contains a crosslinking agent other than the metal salt and the cationic polyacrylamide, and The oil-resistant paper according to claim 1, characterized in that it contains 0.1 to 44% by mass of the crosslinking agent with respect to 100% by mass of the solid content of the oil-resistant layer.
  7. The oil-resistant paper according to claim 1, characterized in that the air permeability of the oil-resistant paper, measured by the Wang-Gan test method (JIS P 8117:2009), is 30,000 seconds or less.
  8. JAPAN TAPPI No. 41 Oil-repellent test method: The oil-resistant paper according to claim 1, characterized in that the kit oil resistance of the oil-resistant paper measured by the kit method is 4 or higher.
  9. The oil-resistant paper according to claim 1, characterized in that the water repellency of the oil-resistant paper, as measured by the JAPAN TAPPI No. 68 water repellency test method, is R2 or higher.
  10. The aforementioned paper substrate contains 70% by mass or more of pulp relative to the total mass of the paper substrate. The oil-resistant paper according to claim 1, characterized in that the pulp has a water content of 100 to 500 ml as measured by the Canadian standard water content test method specified in JIS P 8121-2:2012 "Pulp - Water content test method - Part 2: Canadian standard water content method".
  11. The oil-resistant paper according to claim 1, characterized in that the Steckicht sizing degree of the paper substrate, as defined in JIS P8122:2004 "Paper and paperboard - Sizing test method - Steckicht method," is 0 to 10 seconds.
  12. The oil-resistant paper according to claim 1, characterized in that the filler content relative to the entire paper substrate is 0% by mass or more and 1.0% by mass or less.
  13. The oil-resistant paper according to any one of claims 1 to 12, characterized in that the oil-resistant layer consists of two or more layers.
  14. A method for manufacturing oil-resistant paper having an oil-resistant layer on one or both sides of a paper substrate, The aforementioned manufacturing method is A liquid preparation process for manufacturing an oil-resistant layer-forming composition, The process includes a step of applying or impregnating the paper substrate with the oil-resistant layer-forming composition to form the oil-resistant layer, A method for producing oil-resistant paper, characterized in that the liquid preparation step includes a step of mixing the oil-resistant layer-forming composition such that the amount of hydrophobic starch is 50% by mass or more, at least one metal salt selected from the group consisting of magnesium sulfate, magnesium chloride, and calcium chloride is 3 to 47% by mass, and cationic polyacrylamide is 3 to 47% by mass, based on 100% by mass of the solid component of the oil-resistant layer-forming composition.
  15. The process further includes a paper substrate preparation step for preparing the aforementioned paper substrate, The method for manufacturing oil-resistant paper according to claim 14, characterized in that the paper substrate prepared in the paper substrate preparation step has an air permeability of 10,000 seconds or less as measured by the Wang-Ren test method, JIS P 8117:2009 Air permeability and air permeability resistance test method.
  16. The paper substrate prepared in the aforementioned paper substrate preparation step contains 70% by mass or more of pulp relative to the total mass of the paper substrate. The method for producing oil-resistant paper according to claim 14, characterized in that the pulp has a water drainage of 100 to 500 ml as measured by the Canadian Standard Water Drainage Test Method, JIS P 8121-1995.
  17. The method for manufacturing oil-resistant paper according to claim 14, characterized in that the size of the paper substrate prepared in the paper substrate preparation step is 0 to 10 seconds.
  18. The method for producing oil-resistant paper according to claim 14, characterized in that the content of the filler relative to the entire paper substrate prepared in the paper substrate preparation step is 0% by mass or more and 1.0% by mass or less.

Description

This disclosure relates to oil-resistant paper and a method for manufacturing the same. Oil-resistant paper is widely used as packaging paper and containers for cooked foods such as fast food, fried foods, and baked foods that contain a lot of oil and moisture, as well as for paper-based liner materials such as food trays and oxygen absorbers. Oil-resistant paper, especially thin oil-resistant paper, tends to require both oil resistance and breathability. For example, packaging paper for hamburgers and hot snacks requires both oil resistance (preventing oil from passing through) and breathability (allowing water vapor to pass through). Furthermore, it is preferable that the oil-resistant paper has water-repellent properties to prevent it from getting wet when exposed to water vapor. To provide oil resistance while maintaining breathability, oil-resistant agents containing fluororesins have traditionally been used. For example, oil-resistant paper, where a fluororesin-containing oil-resistant agent is coated onto the surface of paper or cardboard, and oil-resistant paper with fluororesin incorporated between (within) the paper layers are known. However, oil-resistant paper using fluororesins may generate organic fluorine compounds during high-temperature processing such as cooking or incineration. Among these organic fluorine compounds, perfluorooctanesulfonic acid and perfluorooctanoic acid are persistent and highly bioaccumulative, leading to widespread presence in environmental water and wildlife, raising concerns about adverse health and environmental impacts. To solve these problems, oil-resistant paper using hydrophobic starch as an oil-resistant agent has been proposed (see, for example, Patent Documents 1 to 7). Japanese Patent Publication No. 2002-69889Japanese Patent Publication No. 2005-29940Japanese Patent Publication No. 2006-307363Japanese Patent Publication No. 2013-237941Japanese Patent Publication No. 2015-190096Japanese Patent Publication No. 2019-99950WO2024/190610 publication Next, the present invention will be described in detail with reference to embodiments, but the present invention is not to be construed as being limited to these descriptions. Various modifications of the embodiments are possible as long as the effects of the present invention are achieved. The oil-resistant paper according to this embodiment is an oil-resistant paper having an oil-resistant layer on one or both sides of a paper substrate, wherein the oil-resistant layer contains 50% by mass or more of hydrophobic starch, 3 to 47% by mass of at least one metal salt selected from the group consisting of magnesium sulfate, magnesium chloride, and calcium chloride, and 3 to 47% by mass of cationic polyacrylamide, with the amount of the oil-resistant layer adhering to the paper substrate being 1.0 to 5.0 g/ m² in terms of solid content per side when the oil-resistant layer is provided on both sides of the paper substrate, and the amount of the oil-resistant layer adhering to the paper substrate being 0.5 to 2.5 g/ m² in terms of solid content when the oil-resistant layer is provided on only one side of the paper substrate. The oil-resistant paper of this embodiment has an oil-resistant layer formed on one or both sides of a paper base material. The paper base material is not particularly limited and can be appropriately selected and used depending on the application. Examples include bleached or unbleached kraft paper (acidic or neutral paper), fine paper, medium-quality paper, liner paper, and glossy paper on one side. The paper substrate is mainly composed of pulp. "Mainly composed of pulp" means that the pulp content relative to the total mass of the paper substrate is 70% by mass or more. Preferably, the pulp content relative to the total mass of the paper substrate is 90% by mass or more. Examples of pulp include wood pulp, non-wood pulp, recycled paper pulp, and synthetic fiber pulp. Examples of wood pulp include chemical or mechanical pulp from coniferous or hardwood trees. Examples of non-wood pulp include kenaf pulp, bagasse pulp, rag pulp, linen pulp, hemp pulp, kozo pulp, mitsumata pulp, ganpi pulp, straw pulp, or bamboo pulp. Examples of recycled paper pulp include magazine waste paper, flyer waste paper, colored recycled paper, newspaper waste paper, Kent waste paper, white recycled paper, coated recycled paper, photocopied paper, or waste paper. Examples of synthetic fiber pulps include rayon, acetate, vinylon fibers, polyolefin fibers, polyester fibers, acrylic fibers, polyamide resin fibers, polyphenylene resin fibers, and polyurethane resin fibers. Among these, it is preferable to include chemical pulp such as bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), bleached hardwood sulfite pulp (LBSP), bleached softwood sulfite pulp (NBSP), unbleached hardwood kraft pulp (LUKP), unbleached softwood kraft pulp (NUKP), unbleached hardwood sulfite pulp (USP), or unbleached softwood sulfit