Water-repellent and oil-repellent agent

Abstract

Provided is a water-repellent oil-repellent agent containing a polysaccharide and a sizing agent, wherein the polysaccharide exhibits a viscosity of 60 cps or less at 50 DEG C in a 20 mass% aqueous solution.

Description

Technical Field

[0001] The present invention relates to a water- and oil-repellent agent. Background Art

[0002] Food packaging materials and food containers made of paper are required to prevent moisture and oil from penetrating into food. Therefore, in order to impart oil repellency to paper, an oil-proofing agent is applied to the paper (Patent Documents 1 to 4).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-307363

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2002-69889

[0007] Patent Document 3: International Publication No. 2022 / 080464

[0008] Patent Document 4: Japanese Patent Application Publication No. 2022-103182 Summary of the invention

[0009] Technical problem to be solved by the invention

[0010] An object of the present invention is to provide a water-repellent and oil-repellent agent capable of imparting excellent water-repellency and oil-repellency to paper.

[0011] Technical solutions for solving technical problems

[0012] The present invention includes the following aspects.

[0013] <1> A water-repellent and oil-repellent agent comprising a polysaccharide and a sizing agent, wherein the polysaccharide has a viscosity of 60 cps or less at 50°C in a 20% by mass aqueous solution.

[0014] <2> The water-repellent and oil-repellent agent according to <1> above, wherein the polysaccharide is starch.

[0015] <3> The water-repellent and oil-repellent agent according to <2> above, wherein the starch is a hydrophobized modified starch.

[0016] <4> The water-repellent and oil-repellent agent according to <3> above, wherein the hydrophobized modified starch is alkenyl succinate-esterified starch.

[0017] <5> The water- and oil-repellent agent according to any one of <1> to <4> above, wherein the sizing agent is an alkyl ketene dimer.

[0018] <6> The water-repellent and oil-repellent agent according to any one of <1> to <5> above, wherein the viscosity at 50°C is 300 cps or less.

[0019] <7> The water-repellent and oil-repellent agent according to any one of <1> to <6>, wherein the content of the polysaccharide in the water-repellent and oil-repellent agent is 40% by mass or less.

[0020] <8> The water-repellent and oil-repellent agent according to any one of <1> to <7>, wherein the content of the sizing agent in the water-repellent and oil-repellent agent is 5% by mass or less.

[0021] <9> The water-repellent and oil-repellent agent according to any one of <1> to <8>, wherein the content of the sizing agent in the water-repellent and oil-repellent agent is 10% by mass or less based on the total of the polysaccharide and the sizing agent.

[0022] <10> The water- and oil-repellent agent according to any one of <1> to <9> above, further comprising an additive.

[0023] <11> The water-repellent and oil-repellent agent according to any one of <1> to <10>, which is used for treating the surface of paper.

[0024] <12> A water-repellent and oil-repellent paper having a water-repellent and oil-repellent layer formed of the water-repellent and oil-repellent agent according to any one of <1> to <11> above on a surface of the paper.

[0025] <13> The water-repellent and oil-repellent paper according to <12>, wherein the solid content of the water-repellent and oil-repellent agent in the water-repellent and oil-repellent layer is 6.0 g / m 2 the following.

[0026] <14> A method for treating paper, comprising the step of treating the paper by externally adding the water-repellent and oil-repellent agent described in any one of <1> to <11>.

[0027] Effects of the Invention

[0028] According to the present invention, it is possible to provide a water-repellent and oil-repellent agent capable of imparting excellent water-repellency and oil-repellency to paper. DETAILED DESCRIPTION

[0029] <Water and oil repellent>

[0030] The water-repellent and oil-repellent agent of the present invention contains a polysaccharide and a sizing agent, and the polysaccharide has a viscosity of 60 cps or less at 50° C. in a 20% by mass aqueous solution.

[0031] At present, when the oil-proofing agent contains polysaccharides at a high concentration, the viscosity of the oil-proofing agent increases, making it difficult to stably apply the oil-proofing agent to paper. On the other hand, when the oil-proofing agent contains polysaccharides at a low concentration, the oil resistance of the paper decreases.

[0032] The water-repellent and oil-repellent agent of the present invention can impart excellent water-repellency and oil-repellency to paper by having the above characteristics, and can treat paper well and impart excellent water-repellency and oil-repellency to paper even when the polysaccharide concentration is high.

[0033] The water- and oil-repellent agent of the present invention may contain a medium (eg, a liquid medium such as water and an organic solvent). The water- and oil-repellent agent of the present invention is preferably an aqueous dispersion.

[0034] The water-repellent and oil-repellent agent of the present invention contains polysaccharides. The polysaccharides may contain one type of polysaccharides, or may contain two or more types of polysaccharides. The polysaccharides contained in the water-repellent and oil-repellent agent can provide water-repellency and oil-repellency to paper.

[0035] The polysaccharide contained in the water-repellent and oil-repellent agent of the present invention may be a water-soluble polysaccharide or a hydrophobic polysaccharide. The polysaccharide may be dissolved in water, or partially dissolved in water, to form an aqueous solution of the polysaccharide or a dispersion containing the polysaccharide. The aqueous solution or dispersion of the polysaccharide has a predetermined viscosity depending on the amount of the polysaccharide contained in the aqueous solution or dispersion.

[0036] Hereinafter, in this specification, "aqueous solution" is not limited to a form in which the polysaccharide is completely dissolved in a liquid, and can be used to include a form in which the polysaccharide is partially dissolved in a liquid. For example, the "aqueous solution" in this specification also includes a dispersion in which the polysaccharide is dispersed in a liquid, or a suspension in which the polysaccharide is suspended in a liquid.

[0037] The polysaccharide contained in the water-repellent and oil-repellent agent of the present invention exhibits a viscosity of 60 cps or less at 50° C. in a 20% by mass aqueous solution. By exhibiting such a viscosity, the viscosity of the water-repellent and oil-repellent agent is unlikely to increase even when the water-repellent and oil-repellent agent contains the polysaccharide at a high concentration. Therefore, it is easy to apply the water-repellent and oil-repellent agent containing the polysaccharide at a high concentration to paper, and the water-repellency and oil-repellency of the paper can be improved.

[0038] From the viewpoint of facilitating application of the water- and oil-repellent agent of the present invention on paper, the polysaccharide may preferably exhibit a viscosity of 55 cps or less in a 20 mass % aqueous solution at 50° C., and may also exhibit a viscosity of 50 cps or less, further preferably a viscosity of 45 cps or less, particularly preferably a viscosity of 40 cps, and particularly preferably a viscosity of 30 cps.

[0039] From the viewpoint of improving water repellency and oil repellency, the polysaccharide may have a viscosity of 1 cps or more, preferably 5 cps or more, and more preferably 10 cps or more at 50°C in a 20 mass % aqueous solution.

[0040] From the viewpoint of facilitating the application of the water-repellent and oil-repellent agent of the present invention on paper, the polysaccharide may exhibit a viscosity of 200 cps or less in a 20% by mass aqueous solution at 30° C. From the viewpoint of further improving the water-repellency and oil-repellency, the polysaccharide may exhibit a viscosity of preferably 150 cps or less in a 20% by mass aqueous solution at 30° C., and may more preferably exhibit a viscosity of 130 cps or less, and further preferably exhibit a viscosity of 120 cps or less.

[0041] From the viewpoint of improving water repellency and oil repellency, the polysaccharide may have a viscosity of 1 cps or more, preferably 10 cps or more, and more preferably 30 cps or more at 30°C in a 20 mass % aqueous solution.

[0042] The viscosity of the aqueous solution of the polysaccharide is measured using a B-type rotational viscometer. For example, in the measurement using the B-type rotational viscometer, a No. 2 rotor may be used. The rotation speed of the rotor may be 60 rpm.

[0043] The viscosity in a 50°C, 20% by mass aqueous solution can be adjusted, for example, according to the molecular weight of the polysaccharide. Specifically, the viscosity in a 50°C, 20% by mass aqueous solution can be adjusted by cutting the glycosidic bonds of the polysaccharide. The cutting of the glycosidic bonds of the polysaccharide can be carried out, for example, using wet acid treatment, dry acid treatment, heat treatment, amylolytic enzymes or oxidants. By cutting the glycosidic bonds of the polysaccharide, the molecular weight of the polysaccharide becomes smaller, and the viscosity in a 50°C, 20% by mass aqueous solution can be reduced. In other words, a polysaccharide with low viscosity can be obtained. The low viscosity of the polysaccharide can be carried out after the processing (or modification) of the polysaccharide, or before the processing (or modification).

[0044] Polysaccharides may be compounds formed by bonding multiple (3 or more, for example, 3 or more and 2000 or less) monosaccharides such as glucose, galactose, and fructose. Polysaccharides may also be oligosaccharides formed by bonding 3 or more and 10 or less monosaccharides.

[0045] Polysaccharides may be acidic polysaccharides, neutral polysaccharides or alkaline polysaccharides. Acidic polysaccharides are generally polysaccharides having a carboxyl group (-COOH) or the like. Specific examples of acidic polysaccharides are carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar, and tragacanth gum. Neutral polysaccharides are electrically neutral polysaccharides. Specific examples of neutral polysaccharides are tamarind gum, guar gum, locust bean gum, starch, and pullulan. Alkaline polysaccharides are polysaccharides having an amino group (-NH2) or the like. A specific example of alkaline polysaccharides is chitosan.

[0046] Specific examples of polysaccharides include xanthan gum, karaya gum, Brunei gum, guar gum, pectin, tamarind gum, carrageenan, chitosan, gum arabic, locust bean gum, cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose derivatives such as hydroxypropyl methyl cellulose, alginic acid, starch (in other words, starch), agar, dextran, and pullulan. The polysaccharide may also be a substituted polysaccharide, particularly a polysaccharide with a hydroxyl group substituted.

[0047] From the viewpoint of improving water repellency and oil repellency, the polysaccharide may be starch. The starch may be plant starch. For example, the starch may include rice starch, wheat starch, corn starch, potato starch, tapioca starch, sweet potato starch, red bean starch, mung bean starch, kudzu starch or chestnut starch.

[0048] The starch may be unprocessed starch or processed starch. In other words, the starch may be unmodified starch or modified starch. The starch may be a modified starch subjected to at least one modification such as esterification modification, etherification modification, oxidation modification, alkali modification, enzyme modification, and bleaching modification.

[0049] Examples of modified starch include acetylated adipic acid cross-linked starch, acetylated oxidized starch, acetylated phosphate cross-linked starch, alkenyl succinate-esterified starch, acetic acid starch, oxidized starch, hydroxyalkylated starch, hydroxyalkylated phosphate cross-linked starch (e.g., the number of carbon atoms in the alkyl group is 2 to 40 or 2 to 10, especially 2 or 3), phosphate cross-linked starch, phosphated starch, phosphate monoesterified phosphate cross-linked starch, acid-modified starch, alkali-treated starch, enzyme-treated starch, bleached starch, cationized starch (e.g., quaternized starch), and alpha-starch. Examples include dextrins obtained by chemically or enzymatically reducing the molecular weight of starch.

[0050] From the viewpoint of improving water repellency and oil repellency, starch can be a hydrophobized modified starch. Hydrophobized modified starch is a starch that has been modified (hydrophobized) to have a hydrophobic group (e.g., a hydrocarbon group having 1 to 40, 2 to 40, 3 to 30 or 4 to 20 carbon atoms). Examples of hydrophobized modified starch are alkenyl succinate-esterified starch, acetic acid-esterified starch, polyacrylonitrile grafted starch, (meth)acrylic acid or (meth)acrylate grafted starch, and cross-linked starch. Examples of (meth)acrylates are methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate. In cross-linked starch, a multifunctional (2 to 5-valent) agent is used, and examples of multifunctional agents are phosphorus oxychloride, epichlorohydrin, and the like.

[0051] Examples of hydrophobic modification methods include: a method of esterifying raw starch with an alkenyl (e.g., alkenyl having 3 to 40 carbon atoms, such as 5 to 30 or 6 to 24 carbon atoms) derivative of succinic acid (e.g., alkenyl succinic anhydrides such as octenyl succinic anhydride or dodecenyl succinic anhydride) to obtain alkenyl succinate-modified starch (or alkenyl succinate-modified starch); a method of grafting a hydrophobic monomer (e.g., unsaturated nitriles such as acrylonitrile, acrylic monomers such as (meth) alkyl acrylates (e.g., alkyl having 1 to 30 carbon atoms)) with raw starch; a method of reacting raw starch with an organosilane; and a method of imparting a hydrophobic group containing a hydrocarbon group (e.g., having 1 to 30 carbon atoms) to starch by etherification or esterification. When esterifying raw starch to obtain alkenyl succinate-modified starch, the raw starch can be reacted with an alkenyl derivative of succinic acid in a weakly alkaline environment (e.g., pH 7.5 to 8.0). Examples of the raw material starch include natural starches such as corn starch, rice starch, wheat starch, maize starch, potato starch, tapioca starch, and sweet potato starch.

[0052] From the viewpoint of improving water repellency and oil repellency, the polysaccharide may be alkenyl succinate starch (e.g., octenyl succinate starch or octenyl succinate modified starch). In alkenyl succinate starch, the number of carbon atoms of the alkenyl group may be 3 to 40, for example, 5 to 30 or 6 to 24. Specific examples of alkenyl succinate starch include octenyl succinate starch, decenyl succinate starch, dodecenyl succinate starch, tetradecenyl succinate starch, hexadecenyl succinate starch, octadecenyl succinate starch, etc. From the viewpoint of further improving water repellency and oil repellency, alkenyl succinate starch is preferably octenyl succinate starch or octenyl succinate modified starch. For example, sodium octenyl succinate starch is preferred. The degree of esterification of the esterified starch is represented by the degree of substitution (DS mole of substituent per 1 mole of anhydroglucose residue), and the DS may be 0.005 to 0.3 or 0.01 to 0.2.

[0053] The hydrophobic modified starch has a hydrophobic group (e.g., a hydrocarbon group having 1 to 40, 2 to 40, or 3 to 30 carbon atoms), and preferably also has hydrophilicity (e.g., a hydroxyl group, an amino group, a carboxyl group, an oxyalkylene group (the alkylene group has 1 to 3 carbon atoms, particularly 1 or 2)). The presence of the hydrophobic group and the hydrophilic group can improve water repellency and oil repellency.

[0054] The content of the polysaccharide in the water- and oil-repellent agent of the present invention may be 40% by mass or less, preferably 35% by mass or less, more preferably 30% by mass or less, further preferably 25% by mass, and further more preferably 20% by mass or less.

[0055] The content of the polysaccharide in the water- and oil-repellent agent of the present invention may be 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, further preferably 7% by mass or more, further preferably 10% by mass or more, and particularly preferably 15% by mass or more.

[0056] The water-repellent and oil-repellent agent of the present invention contains a sizing agent. When the water-repellent and oil-repellent agent contains a sizing agent, the water-repellent and oil-repellent properties of the water-repellent and oil-repellent agent can be improved. The sizing agent used in the water-repellent and oil-repellent agent of the present invention can be a sizing agent available as a commercial product.

[0057] Examples of the sizing agent include olefin sizing agents, rosin sizing agents, acrylic sizing agents, polyacrylamide sizing agents, styrene-maleic acid sizing agents, acrylic copolymer sizing agents, acrylic emulsion sizing agents, olefin-maleic acid resin sizing agents, polyurethane sizing agents, AKD (alkyl ketene dimer) sizing agents, ASA (alkenyl succinic anhydride) sizing agents, and petroleum resin sizing agents. The ionicity of the sizing agent may be cationic, anionic, or nonionic. From the perspective of further improving water repellency and oil repellency, the sizing agent may be an alkyl ketene dimer.

[0058] The alkyl ketene dimer may be, for example, a compound represented by the following formula.

[0059]

[0060] [Where: R 1 is an alkyl or alkenyl group, R 2 is an alkyl or alkenyl group.]

[0061] From the perspective of further improving water repellency and oil repellency, R 1 and R 2 Each of them independently may be an alkyl group or alkenyl group having 4 to 32 carbon atoms, preferably an alkyl group or alkenyl group having 8 to 28 carbon atoms, more preferably an alkyl group or alkenyl group having 12 to 24 carbon atoms, and further preferably an alkyl group or alkenyl group having 14 to 24 carbon atoms.

[0062] The content of the sizing agent in the water- and oil-repellent agent of the present invention may be 5% by mass or less, preferably 0.1% by mass to 5% by mass, more preferably 0.3% by mass to 3% by mass, and further preferably 0.5% by mass to 1% by mass.

[0063] The sizing agent in the water-repellent and oil-repellent agent of the present invention may contain 10% by mass or less, preferably 1% to 10% by mass, more preferably 1% to 8% by mass, and further preferably 2% to 5% by mass, based on the total content of the polysaccharide and the sizing agent contained in the water-repellent and oil-repellent agent of the present invention.

[0064] The viscosity of the water-repellent and oil-repellent agent at 50°C may be 300 cps or less. When the water-repellent and oil-repellent agent of the present invention has such a viscosity, it is easy to apply the water-repellent and oil-repellent agent of the present invention to paper. From the viewpoint of making it easier to apply the water-repellent and oil-repellent agent of the present invention to paper, the viscosity of the water-repellent and oil-repellent agent of the present invention at 50°C is preferably 1 to 300 cps, more preferably 30 cps to 250 cps, and even more preferably 50 cps to 200 cps.

[0065] The water-repellent and oil-repellent agent of the present invention may further contain additives, such as pH adjusters, paper strength enhancers, retention aids, colorants (dyes / pigments), fluorescent colorants, slime controllers, anti-slip agents, defoamers, and the like.

[0066] <Application>

[0067] The water-repellent and oil-repellent agent of the present invention can be used as an external treatment agent (surface treatment agent) or an internal treatment agent. The product treated with the water-repellent and oil-repellent agent has high water repellency and / or oil repellency. Therefore, the water-repellent and oil-repellent agent is used as a water-repellent and / or oil-repellent agent. The water-repellent and oil-repellent agent can also be used as an antifouling agent, an oil-resistant agent, a detergent, a stripping agent or a release agent or a component thereof.

[0068] <Water and oil repellent paper>

[0069] The water-repellent and oil-repellent agent of the present invention can be used to treat paper (e.g., surface treatment). That is, the water-repellent and oil-repellent agent of the present invention can be used to treat the surface of paper. By using the water-repellent and oil-repellent agent of the present invention to treat paper, water-repellent and oil-repellent paper can be obtained.

[0070] The water-repellent and oil-repellent agent can be applied to paper by a conventionally known method, for example, an internal addition method of adding the water-repellent and oil-repellent agent of the present invention to pulp slurry before papermaking, or an external addition method of applying the water-repellent and oil-repellent agent of the present invention to paper after papermaking.

[0071] The treatment method of the water-repellent and oil-repellent agent of the present invention is preferably an external addition treatment method. As the external addition treatment method, a size press, coating (such as a gate roller coater, a Bill blade coater, a rod coater, etc.), a spray device, etc. can be used. The following method can also be used: the water-repellent and oil-repellent agent is dispersed in an organic solvent or water and diluted, and is attached to the surface of the treated object by a known method such as immersion coating, spraying, foam coating, etc. and then dried.

[0072] The size press of the external addition treatment method can also be divided according to the coating method as follows. One of the coating methods is the so-called glue pool type double roller size press, in which a coating liquid (i.e., a sizing liquid) is supplied to the nip formed when the paper passes between two rubber rollers to form a coating liquid accumulation part called a glue pool (pond), and the paper is passed through the coating liquid accumulation part, thereby coating the sizing liquid on both sides of the paper. Other coating methods include gate roller type and rod type metering size presses that use a surface transfer mold to apply the sizing liquid. In the glue pool type double roller size press, the sizing liquid easily penetrates into the interior of the paper, and the sizing liquid components in the surface transfer mold easily stay on the surface of the paper. Compared with the glue pool type double roller size press, the coating layer of the surface transfer mold is more likely to stay on the surface of the paper, and the water-repellent and oil-repellent layer formed on the surface is more than that of the glue pool type double roller size press. In the present invention, even in the case of using the former glue pool type double roller size press, water-repellent and oil-repellent properties can be imparted to the paper. The paper treated in this way is simply dried at room temperature or high temperature and then, depending on the properties of the paper, optionally accompanied by heat treatment at a temperature of up to 300°C, for example up to 200°C, especially in the range of 80°C to 180°C, thereby showing excellent water-repellency and oil-repellency.

[0073] As a method for treating paper of the present invention, a method of adding the water-repellent and oil-repellent agent of the present invention to paper by on-machine sizing can be adopted. That is, it can be a method of treating paper in which the manufacturing process and the coating process of paper are integrated (in other words, continuous). For example, as a method for treating paper of the present invention, it can be the following method: supplying the paper raw material slurry to the wire part of the papermaking machine for dehydration, and then using the press part to squeeze the water, and then passing it through the drying part (dryer part) for drying, thereby obtaining a base paper for coating, and then passing the base paper for coating through a coating head (coater head), after coating the water-repellent and oil-repellent agent, passing it through the drying part to dry it.

[0074] The water-repellent and oil-repellent agent of the present invention can be used in gypsum board base paper, coated base paper, medium-quality paper, general lining paper and core, neutral pure white roll paper, neutral lining paper, rust-proof lining paper and metal-clad paper, kraft paper, etc. It can also be used in neutral printing and writing paper, neutral coated base paper, neutral PPC paper, neutral thermal paper, neutral pressure-sensitive base paper, neutral inkjet paper and neutral information paper.

[0075] The paper treated with the water-repellent and oil-repellent agent of the present invention can be a container made of paper, a molded body formed of paper (such as a pulp molded product), etc. For example, food packaging materials and food containers are preferred. Paper can be manufactured using currently known papermaking methods.

[0076] As the pulp raw material, any of bleached or unbleached chemical pulps such as kraft pulp and sulfite pulp, bleached or unbleached high-yield pulps such as wood pulp, mechanical pulp or thermomechanical pulp, and waste paper pulps such as waste newspapers, waste magazines, waste corrugated paper, and waste deinked paper can be used. A mixture of the above pulp raw materials and synthetic fibers such as asbestos, polyamide, polyimide, polyester, polyolefin, and polyvinyl alcohol can also be used.

[0077] The water resistance of paper can also be improved by adding a sizing agent. The sizing agent is, for example, a cationic sizing agent, an anionic sizing agent, or a rosin-based sizing agent (e.g., an acidic rosin-based sizing agent or a neutral rosin-based sizing agent). The amount of the sizing agent can be 0.01% by mass to 5% by mass relative to the pulp.

[0078] In paper, as required, as a papermaking agent of the usual degree of use, paper strength enhancers such as carboxymethyl cellulose, polyamide polyamine-epichlorohydrin resin, coagulants, fixatives, retention aids, dyes, fluorescent dyes, sizing agents, defoamers, etc., used in the manufacture of paper, can be used. As required, polyvinyl alcohol, glucose, dyes, coating colorants, anti-slip agents, etc. can be used to apply water-repellent and oil-repellent agents on paper by size press, gate roll coater, Bill blade coater, calender, etc. As an additive, polyvinyl alcohol or glucose is preferably used. By using polyvinyl alcohol or glucose together with polysaccharides, high water-repellent and oil-repellent properties can be obtained. The amount of polyvinyl alcohol as a papermaking agent can be 1 mass part or more and 1000 mass parts or less, 2 mass parts or more and 200 mass parts or less, 3 mass parts or more and 100 mass parts or less, or 5 mass parts or more and 50 mass parts or less, and in particular, 10 mass parts or more and 40 mass parts or less, relative to 100 mass parts of polysaccharides.

[0079] The water-repellent and oil-repellent paper of the present invention has a water-repellent and oil-repellent layer formed by the water-repellent and oil-repellent agent of the present invention on the surface of the paper. The content of polysaccharide in the water-repellent and oil-repellent layer can be 6.0 g / m 2 Below, preferably 0.02g / m 2 Above 6.0g / m2 Below, more preferably 0.2g / m 2 Above 5.0g / m 2 Below, more preferably 0.5 g / m 2 Above 4.0g / m 2 Below, particularly preferably 1.0 g / m 2 Above 3.0g / m 2 The content of the water-repellent and oil-repellent agent in the water-repellent and oil-repellent layer may be the solid content of the water-repellent and oil-repellent agent (for example, the total of the contents of the polysaccharide and the sizing agent).

[0080] In the external addition, the sizing agent contained in the water-repellent and oil-repellent layer can be 0.01 g / m 2 Above 2.0g / m 2 Below, preferably 0.01g / m 2 Above 1.5g / m 2 Below, more preferably 0.03g / m 2 Above 1.3g / m 2 Below, particularly preferably 0.05 g / m 2 Above 1.0g / m 2 the following.

[0081] The water-repellent and oil-repellent paper of the present invention may have an air permeability of, for example, 1000 seconds or more, 2000 seconds or more, and particularly 3000 seconds or more. The air permeability is measured based on JISP8117 (2009). The greater the air permeability, the higher the gas barrier property, and it is difficult for not only gases such as oxygen but also water (including water vapor) to pass through.

[0082] Example

[0083] Hereinafter, the water-repellent and oil-repellent agent of the present invention will be described with reference to Examples, but the present invention is not limited to the following Examples.

[0084] The test methods used below are as follows.

[0085] Viscosity measurement

[0086] The viscosity was measured using a B-type viscometer. The viscosity was measured at a rotation speed of 60 rpm and a temperature of 50° C., using a No. 2 rotor. The B-type viscometer used was a digital viscometer manufactured by Blookfield.

[0087] Oil resistance test (practical oil test)

[0088] Water- and oil-repellent paper to which about 0.1 g of commercially available olive oil was dropped was placed in an oven at 70° C., taken out after 7 minutes, and the penetration state was observed.

[0089] According to the degree of penetration of the back surface, the evaluation value is set as follows.

[0090] 5: 0-5%

[0091] 4: 6-20%

[0092] 3:21-50%

[0093] 2: 51-75%

[0094] 1:76-100%

[0095] Water absorption (Cobb value) evaluation

[0096] The water absorption (Cobb value) is measured based on JIS P 8140:1998.

[0097] Place a paper substrate on the surface of a hard platen with one side smoothed, and fix a metal cylinder with an inner diameter of 112.8 mm on the surface using a clamp. Then, pour water into the cylinder to a depth of 10 mm. After the water and paper substrate come into contact, calculate the weight of the water absorbed within 1 minute. Convert the obtained value into weight per square meter (gsm) to calculate the water absorption (Cobb value).

[0098] Breathability

[0099] The air permeability (air resistance) of the container bottom of paper formed into a container shape was measured based on JISP8117 (2009) using an automatic Gurley air permeometer (product No. 323-AUTO, air pore diameter 28.6±0.1 mm) manufactured by Yasuda Seiki Co., Ltd.

[0100] Viscosity measurement of 20 mass % aqueous solution of polysaccharides

[0101] A predetermined amount of octenyl succinic acid modified starch-1 was dissolved in water to prepare an aqueous solution having a concentration of 20% by mass of octenyl succinic acid modified starch. The viscosity of the aqueous solution was measured. For octenyl succinic acid modified starch-2 and octenyl succinic acid modified starch-3, 20% by mass aqueous solutions were also prepared and the viscosity was measured. The results of these viscosity measurements are shown in Table 1.

[0102] [Table 1]

[0103] Polysaccharides 50℃, 20 mass% aqueous solution viscosity (cps) Octenyl succinic acid modified starch-1 47 Octenyl succinate modified starch-2 25 Octenyl succinate modified starch-3 390

[0104] [Example 1]

[0105] (Production of base paper)

[0106] As wood pulp, a pulp slurry was prepared in which the mass ratio of LBKP (bleached kraft pulp of broadleaf trees) to NBKP (bleached kraft pulp of coniferous trees) was 60 mass% and 40 mass%, and the pulp freeness was 400 ml (Canadian Standard Freeness). To this pulp slurry, a wet paper strength agent was added in an amount of 0.5 wt% relative to the dry pulp in terms of solid content concentration, and the paper was made into a paper having a density of 0.58 g / cm by a Fourdrinier papermaking machine. 3 Weight per unit area: 48g / m 2 The paper was used as the base paper for external addition treatment (size press treatment). The oil resistance (practical oil test) of the base paper was 1. The water absorption (Cobb value) of the base paper was 65. The air permeability of the base paper was 250 seconds.

[0107] (Manufacture of Octenylsuccinic Acid Modified Starch)

[0108] To a flask containing 400 parts of water, 20 parts of corn starch were added in small amounts at 25° C. while vigorously stirring, and then dilute hydrochloric acid was added and stirred until the pH became 4 or less.

[0109] The aqueous solution is dried at about 70 to 90° C. until the moisture content is 7% or less, and then calcined at 160° C. until a predetermined viscosity is reached, thereby obtaining low-viscosity corn starch.

[0110] 100 parts of the obtained low-viscosity corn starch was added in a flask containing 120 parts of water in small amounts while stirring, and then the pH was neutralized with a 2% sodium hydroxide aqueous solution.

[0111] Next, while maintaining the pH at 7.5 to 8.0, 4 parts of octenylsuccinic anhydride was added, and the mixture was reacted at about 30 to 40° C. for 5 hours.

[0112] After the reaction, the mixture was neutralized with dilute sulfuric acid and then washed several times with 300 parts of water.

[0113] The obtained solid was dried and then finely pulverized to obtain sodium starch octenyl succinate as octenyl succinate-modified starch. By adjusting the roasting time at 160° C., sodium starch octenyl succinates 1 to 3 having different desired viscosities were obtained.

[0114] (Production of water-repellent and oil-repellent paper)

[0115] The water-repellent and oil-repellent agent was adjusted so that the octenyl succinic acid-modified starch-1 was 20% by mass and the alkyl ketene dimer was 0.5% by mass, and the paper was treated with a size press and then dried with a drum dryer to obtain water-repellent and oil-repellent paper (processed paper). The viscosity of the water-repellent and oil-repellent agent was 60 cps. The coating amount of the solid content of the octenyl succinic acid-modified starch-1 and the alkyl ketene dimer in the obtained water-repellent and oil-repellent paper was 3.2 g / m 2 . The obtained water-repellent and oil-repellent paper was used as test paper to carry out an oil resistance test (practical oil test), a water absorption (Cobb value) evaluation and an air permeability evaluation. The evaluation results are shown in Table 2. The size press process described herein (using a size press manufactured by Mathis) is a so-called glue pool type double-roll size press process, in which the water-repellent and oil-repellent agent is accumulated between the rolls, and the base paper is passed through the water-repellent and oil-repellent agent between the rolls at an arbitrary roll speed and clamping pressure.

[0116] [Example 2]

[0117] The same treatment as in Example 1 was performed except that the alkyl ketene dimer was adjusted to 1.0 mass %. The coating amount of the total solid content of the octenyl succinic acid-modified starch-1 and the alkyl ketene dimer in the obtained water-repellent and oil-repellent paper was 3.5 g / m 2 The viscosity of the water-repellent and oil-repellent agent was 108 cps. The evaluation results are shown in Table 2.

[0118] [Example 3]

[0119] The same treatment as in Example 1 was performed except that octenyl succinic acid-modified starch-2 was used. The coating amount of the solid content of octenyl succinic acid-modified starch-2 in the obtained water-repellent and oil-repellent paper was 3.2 g / m 2 The viscosity of the water-repellent and oil-repellent agent was 58 cps. The evaluation results are shown in Table 2.

[0120] [Example 4]

[0121] The same treatment as in Example 1 was performed except that the octenyl succinic acid-modified starch-2 was adjusted to 20 mass % and the alkyl ketene dimer was adjusted to 1.0 mass %. The coating amount of the total solid content of the octenyl succinic acid-modified starch-2 and the alkyl ketene dimer in the obtained water-repellent and oil-repellent paper was 3.4 g / m 2 The viscosity of the water-repellent and oil-repellent agent was 91 cps. The evaluation results are shown in Table 2.

[0122] [Comparative Example 1]

[0123] The same treatment as in Example 1 was performed except that octenyl succinic acid-modified starch-3 was used. The viscosity of the water-repellent and oil-repellent agent was 390 cps. Since the viscosity of the water-repellent and oil-repellent agent was high, the paper could not be treated with the water-repellent and oil-repellent agent. The evaluation results are shown in Table 2.

[0124] [Comparative Example 2]

[0125] The same treatment as in Example 1 was performed except that the alkyl ketene dimer was not used. The viscosity of the water-repellent and oil-repellent agent was 45 cps. The coating amount of the solid content of the octenyl succinic acid-modified starch-1 in the obtained water-repellent and oil-repellent paper was 3.2 g / m 2 The evaluation results are shown in Table 2.

[0126] [Table 2]

[0127]

[0128] The above results show that the water-repellent and oil-repellent agent of the present invention can impart excellent water-repellency and oil-repellency to paper.

[0129] Industrial Applicability

[0130] The water-repellent and oil-repellent agent of the present invention can be suitably used for paper used for food containers and food packaging materials.

Claims

1. A water-repellent and oil-repellent agent, characterized in that: Contains polysaccharides and sizing agents, The polysaccharide has a viscosity of 60 cps or less at 50° C. in a 20% by mass aqueous solution.

2. The water-repellent and oil-repellent agent according to claim 1, characterized in that: The polysaccharide is starch.

3. The water-repellent and oil-repellent agent according to claim 2, characterized in that: The starch is hydrophobically modified starch.

4. The water-repellent and oil-repellent agent according to claim 3, characterized in that: The hydrophobic modified starch is alkenyl succinate-modified starch.

5. The water-repellent and oil-repellent agent according to any one of claims 1 to 4, characterized in that: The sizing agent is an alkyl ketene dimer.

6. The water-repellent and oil-repellent agent according to any one of claims 1 to 5, characterized in that: The water-repellent and oil-repellent agent has a viscosity of less than 300 cps at 50°C.

7. The water-repellent and oil-repellent agent according to any one of claims 1 to 6, characterized in that: The content of the polysaccharide in the water- and oil-repellent agent is 40% by mass or less.

8. The water-repellent and oil-repellent agent according to any one of claims 1 to 7, characterized in that: The content of the sizing agent in the water- and oil-repellent agent is 5 mass % or less.

9. The water-repellent and oil-repellent agent according to any one of claims 1 to 8, characterized in that: The content of the sizing agent in the water- and oil-repellent agent is 10% by mass or less based on the total of the polysaccharide and the sizing agent.

10. The water-repellent and oil-repellent agent according to any one of claims 1 to 9, characterized in that: Also contains additives.

11. The water-repellent and oil-repellent agent according to any one of claims 1 to 10, characterized in that: It is used to treat the surface of paper.

12. A water-repellent and oil-repellent paper, characterized in that: A water-repellent and oil-repellent layer formed of the water-repellent and oil-repellent agent according to any one of claims 1 to 11 is provided on the surface of the paper.

13. The water-repellent and oil-repellent paper according to claim 12, characterized in that: The solid content of the water-repellent and oil-repellent agent in the water-repellent and oil-repellent layer is 6.0 g / m 2 the following.

14. A method for processing paper, characterized in that: The method comprises the step of treating the paper by externally adding the water-repellent and oil-repellent agent according to any one of claims 1 to 11.

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