Water-repellent oil-repellent agent

Abstract

The present invention relates to a water-repellent and oil-repellent agent containing a modified starch, in which the modified starch contains a hydrophobically modified starch that exhibits a viscosity of 60 cps or less at a temperature of 50 DEG C in a 20 mass% aqueous solution, and the proportion of the hydrophobically modified starch in the modified starch contained in the water-repellent and oil-repellent agent is 60 mass% or more.

Description

Technical Field

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

[0002] There is a need for food packaging materials and food containers made of paper to prevent moisture and oil from penetrating into food. Therefore, in order to impart oil repellency to paper, an oil-proofing agent has been applied to paper (Patent Documents 1 to 4).

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2006-307363 Patent Document 2: Japanese Patent Application Publication No. 2002-69889 Patent Document 3: International Publication No. 2022 / 080464 Patent Document 4: Japanese Patent Application Publication No. 2022-103182 Summary of the invention

[0004] Problems to be solved by the invention An object of the present invention is to provide a water- and oil-repellent agent capable of imparting excellent water- and oil-repellency to paper.

[0005] Technical solutions to solve problems The present invention includes the following embodiments.

[0006] <1> A water- and oil-repellent containing modified starch, wherein the modified starch comprises a hydrophobic modified starch having a viscosity of 60 cps or less at a temperature of 50° C. in a 20% by mass aqueous solution, and the proportion of the hydrophobic modified starch in the modified starch contained in the water- and oil-repellent is 60% by mass or more.

[0007] <2> According to the above <1> The water- and oil-repellent agent, wherein the hydrophobically modified starch is alkenyl succinate-esterified starch.

[0008] <3> According to the above <1> or <2> The water- and oil-repellent agent comprises the hydrophobically modified starch in an amount of 75% by mass or more.

[0009] <4> According to the above <1> ~ <3> The water- and oil-repellent agent described in any one of the preceding claims, wherein the modified starch consists of the hydrophobically modified starch.

[0010] <5> According to the above <1> ~ <4> The water- and oil-repellent agent described in any one of the preceding claims, wherein the modified starch further comprises a modified starch having a hydrophilic group.

[0011] <6> According to the above <1> ~ <5> The water- and oil-repellent according to any one of the preceding claims, wherein the viscosity of the water- and oil-repellent at a temperature of 50° C. is 300 cps or less.

[0012] <7> According to the above <1> ~ <6> The water- and oil-repellent agent described in any one of the preceding claims, wherein the content of the modified starch in the water- and oil-repellent agent is 40% by mass or less.

[0013] <8> According to the above <1> ~ <7> The water- and oil-repellent agent described above may further include an additive.

[0014] <9> According to the above <1> ~ <8> The water- and oil-repellent agent described above is used for treating the surface of paper.

[0015] <10> A water-repellent and oil-repellent paper, wherein on the surface of the paper, there is the above <1> ~ <9> A water- and oil-repellent layer formed by any one of the water- and oil-repellent agents.

[0016] <11> According to the above <10> The water-repellent and oil-repellent paper, 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.

[0017] <12> A method for processing paper, comprising: <1> ~ <10> The step of adding the water- and oil-repellent agent described in any one of the above to paper.

[0018] Effects of the Invention According to the present invention, it is possible to provide a water- and oil-repellent agent capable of imparting excellent water- and oil-repellency to paper. DETAILED DESCRIPTION

[0019] <Water and oil repellent> The water- and oil-repellent of the present invention is a water- and oil-repellent containing modified starch, wherein the modified starch is a hydrophobic modified starch that exhibits a viscosity of 60 cps or less at a temperature of 50° C. in a 20% by mass aqueous solution, and the proportion of the hydrophobic modified starch in the modified starch contained in the water- and oil-repellent is 60% by mass or more.

[0020] In the past, when the oil-proofing agent contained a high concentration of polysaccharides such as modified starch, the viscosity of the oil-proofing agent would increase, and it would be difficult to stably apply the oil-proofing agent to paper. On the other hand, when the oil-proofing agent contained a low concentration of polysaccharides such as modified starch, it would be difficult to impart sufficient oil resistance to paper.

[0021] The water- and oil-repellent agent of the present invention has the above characteristics, and therefore can impart excellent water and oil repellency to paper. In particular, even when the concentration of modified starch is increased, the paper can be well treated and excellent water and oil repellency can be imparted to the paper.

[0022] The water- and oil-repellent agent of the present invention may also contain a medium (eg, a liquid medium such as water and an organic solvent). The water- and oil-repellent agent of the present invention may preferably be an aqueous dispersion.

[0023] The water- and oil-repellent of the present invention comprises modified starch. The modified starch may be composed of one modified starch, or may be composed of two or more modified starches. In a certain embodiment, the water- and oil-repellent of the present invention may also comprise polysaccharides other than modified starch. The modified starch contained in the water- and oil-repellent may bring water repellency and oil repellency to paper.

[0024] The modified starch contained in the water- and oil-repellent agent of the present invention includes hydrophobically modified starch. In other words, the water- and oil-repellent agent of the present invention includes hydrophobically modified starch as modified starch. The hydrophobically modified starch can be dissolved in water or partially dissolved in water to form an aqueous solution of hydrophobically modified starch or a dispersion of hydrophobically modified starch. The aqueous solution or dispersion of hydrophobically modified starch has a set viscosity according to the content of hydrophobically modified starch in the aqueous solution or dispersion.

[0025] Hereinafter, in this specification, "aqueous solution" is not limited to the form in which the modified starch is completely dissolved in a liquid, and the form in which the modified starch is partially dissolved in a liquid can also be used as a form included in this concept. For example, the "aqueous solution" in this specification also includes forms such as a dispersion in which the modified starch is dispersed in a liquid and a suspension in which the modified starch is suspended in a liquid.

[0026] Modified starch refers to chemically modified or processed starch, specifically refers to starch that has been modified by at least one selected from oxidation modification, alkali modification, enzyme modification, bleaching modification, etc. Modified starch can also be called processed starch.

[0027] Hydrophobically modified starch is starch that has been modified (hydrophobic treatment) to have a hydrophobic group (e.g., a hydrocarbon group with 1 to 40, 2 to 40, 3 to 30, or 4 to 20 carbon atoms). Examples of hydrophobically modified starch include alkenyl succinate starch, acetic acid esterified starch, polyacrylonitrile grafted starch, (meth)acrylate starch, (meth)acrylate grafted starch, or cross-linked starch. Examples of (meth)acrylate esters of (meth)acrylate starch include methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate. In cross-linked starch, a multifunctional (2- to 5-membered) reagent is used, and examples of the multifunctional reagent include phosphorus oxychloride, epichlorohydrin, and the like.

[0028] Examples of hydrophobic modification methods include a method of esterifying raw starch with alkenyl (e.g., alkenyl having 3 to 40 carbon atoms, such as 5 to 30 or 6 to 24) derivatives of succinic acid (e.g., alkenyl succinic anhydrides such as octenyl succinic anhydride and dodecenyl succinic anhydride) to obtain alkenyl succinic acid esterified starch, a method of grafting a hydrophobic monomer (e.g., unsaturated nitriles such as acrylonitrile, acryloyl monomers such as alkyl (meth) acrylates (e.g., alkyl having 1 to 30 carbon atoms)) to raw starch, a method of reacting raw starch with silicone, 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. Examples of raw starch include natural starches such as rice starch, wheat starch, corn starch, potato starch, tapioca starch, and sweet potato starch.

[0029] The hydrophobically modified starch contained in the water- and oil-repellent of the present invention shows a viscosity of less than 60cps at a temperature of 50°C in an aqueous solution of 20 mass %. Due to showing such viscosity, even when the water- and oil-repellent contains a high concentration of hydrophobically modified starch, the water- and oil-repellent viscosity is not easy to increase. Therefore, it is easy to apply the water- and oil-repellent containing a high concentration of hydrophobically modified starch on paper, and the water repellency and oil repellency of the paper can be improved.

[0030] From the perspective of facilitating application of the water- and oil-repellent agent of the present invention on paper, the hydrophobically modified starch preferably exhibits a viscosity of preferably 55 cps or less, more preferably 50 cps or less, further preferably 45 cps or less, particularly preferably 40 cps, and more particularly preferably 30 cps in a 20% by mass aqueous solution at a temperature of 50°C.

[0031] From the viewpoint of improving water and oil repellency, the hydrophobically modified starch preferably exhibits a viscosity of 1 cps or more, preferably 5 cps or more, and more preferably 10 cps or more in a 20 mass % aqueous solution at 50° C.

[0032] From the perspective of facilitating the application of the water- and oil-repellent agent of the present invention on paper, the hydrophobically modified starch exhibits a viscosity of 200 cps or less in a 20% by mass aqueous solution at a temperature of 30° C. From the perspective of further improving water repellency and oil repellency, the hydrophobically modified starch exhibits a viscosity of preferably 150 cps or less, more preferably 130 cps or less, and further preferably 120 cps or less in a 20% by mass aqueous solution at a temperature of 30° C.

[0033] From the viewpoint of improving water repellency and oil repellency, the hydrophobically modified starch may exhibit a viscosity of 1 cps or more, preferably 10 cps or more, and more preferably 30 cps or more in a 20 mass % aqueous solution at 30°C.

[0034] The viscosity of the aqueous solution is measured using a B-type rotational viscometer. For example, when the B-type rotational viscometer is used for measurement, a No. 2 rotor is used. The rotation speed of the rotor is set to 60 rpm.

[0035] The viscosity of a 50°C, 20% by mass aqueous solution can be adjusted by, for example, adjusting the molecular weight of the modified starch. Specifically, the viscosity of a 50°C, 20% by mass aqueous solution can be adjusted by cutting the glycosidic bonds of the modified starch. Cutting of the glycosidic bonds of the modified starch can also be carried out, for example, by using wet acid treatment, dry acid treatment, heat treatment, starch degrading enzymes or oxidants. By cutting the glycosidic bonds of the modified starch, the molecular weight of the modified starch can be reduced and the viscosity of the 50°C, 20% by mass aqueous solution can be reduced. That is, a hydrophobic modified starch with a lower viscosity can be obtained. The low viscosity of the modified starch can be carried out after the modified starch is processed, or it can be carried out before processing.

[0036] In the modified starch contained in the water- and oil-repellent agent of the present invention, the ratio of hydrophobically modified starch is more than 60 mass %. Due to the hydrophobically modified starch containing such a ratio, the viscosity of the water- and oil-repellent agent is difficult to increase. Therefore, even when containing high concentration hydrophobically modified starch, it is also easy to apply the water- and oil-repellent agent on paper, it is possible to improve the water repellency and oil repellency of paper.

[0037] From the viewpoint of improving water repellency and oil repellency, the proportion of the hydrophobic modified starch in the modified starch contained in the water- and oil-repellent of the present invention is preferably 65% ​​by mass or more, more preferably 70% by mass or more, further preferably 75% by mass or more, further preferably 85% by mass or more, and particularly preferably 100% by mass.

[0038] From the viewpoint of improving water repellency and oil repellency, the hydrophobically modified starch may be alkenyl succinate-modified starch, preferably octenyl succinate-modified starch or octenyl succinic acid-modified starch.

[0039] The number of carbon atoms of the alkenyl group of the alkenyl succinate starch may be 3 to 40, for example, 5 to 30 or 6 to 24. Specific examples of alkenyl succinate starch include octenyl succinate starch (or octenyl succinate modified starch), decenyl succinate starch, dodecenyl succinate starch, tetradecenyl succinate starch, hexadecenyl succinate starch, octadecenyl succinate starch, etc. From the perspective of improving water repellency and oil repellency, the alkenyl succinate starch is preferably octenyl succinate starch or octenyl succinate modified starch. For example, sodium octenyl succinate starch is preferred. Alkenyl succinate starch is also called alkenyl succinate modified starch. The degree of esterification of the esterified starch is expressed as the degree of substitution (the number of moles of substituents DS per mole of anhydrous glucose residue), and DS may be 0.005 to 0.3 or 0.01 to 0.2.

[0040] As a method for producing alkenyl succinate starch, a raw material starch may be esterified with an alkenyl (e.g., alkenyl carbon number 3 to 40, e.g., 5 to 30 or 6 to 24) derivative of succinic acid (e.g., alkenyl succinic anhydride such as octenyl succinic anhydride and dodecenyl succinic anhydride) to obtain alkenyl succinate starch. When the raw material starch is esterified to obtain alkenyl succinate starch, the raw material starch and the alkenyl derivative of succinic acid may be reacted in a weakly alkaline environment (e.g., pH 7.5 to 8.0). Examples of raw material starch include natural starches such as corn starch (Tomorokoshi starch), rice starch, wheat starch, corn starch (cornstarch), potato starch, tapioca starch, and sweet potato starch.

[0041] From the perspective of improving water repellency and oil repellency, the modified starch contained in the water and oil repellent of the present invention may also be composed of hydrophobic modified starch. In other words, the water and oil repellent of the present invention may contain only hydrophobic modified starch as the modified starch.

[0042] From the viewpoint of further improving water repellency and oil repellency, the modified starch contained in the water and oil repellent of the present invention may be made of alkenyl succinate starch. In other words, the water and oil repellent of the present invention may contain only alkenyl succinate starch as the modified starch.

[0043] The content of the modified starch in the water- and oil-repellent 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 or less, and still further preferably 20% by mass or less.

[0044] The content of the modified starch in the water- and oil-repellent 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, particularly preferably 15% by mass or more.

[0045] The content of the hydrophobically modified starch in the water- and oil-repellent agent of the present invention can be below 40 mass %. When the contained water- and oil-repellent agent is at this content, it is not only easy to improve the water repellency and oil repellency of paper, but also easier to apply the water- and oil-repellent agent on paper. From the angle of improving water repellency and oil repellency and the coatability on paper, the content of the hydrophobically modified starch in the water- and oil-repellent agent of the present invention is preferably below 35 mass %, more preferably below 30 mass %, further preferably below 25 mass %, particularly preferably below 20 mass %.

[0046] The content of the hydrophobically modified starch in the water- and oil-repellent of the present invention is preferably 1% by mass or more. From the perspective of improving water repellency and oil repellency, the content of the hydrophobically modified starch in the water- and oil-repellent of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.

[0047] The water- and oil-repellent agent of the present invention contains a hydrophobically modified starch having a viscosity of 60 cps or less in a 20% by mass aqueous solution at a temperature of 50° C., and may also contain a hydrophobically modified starch having a viscosity of more than 60 cps in a 20% by mass aqueous solution at a temperature of 50° C. From the perspective of improving water repellency and oil repellency, the water- and oil-repellent agent of the present invention preferably does not contain a hydrophobically modified starch having a viscosity of more than 60 cps in a 20% by mass aqueous solution at a temperature of 50° C.

[0048] The viscosity of the water-repellent and oil-repellent at a temperature of 50°C may be below 300cps. When the water-repellent and oil-repellent of the present invention has this viscosity, the water-repellent and oil-repellent of the present invention will become easy to apply on paper. From the perspective of making the water-repellent and oil-repellent of the present invention easier to apply on paper, the viscosity of the water-repellent and oil-repellent of the present invention at a temperature of 50°C is preferably 1 to 300cps, more preferably 30cps to 250cps, and further preferably 50cps to 200cps.

[0049] The water- and oil-repellent of the present invention can also contain additives. As additives, sizing agents, paper strength enhancers, yield improvers, colorants (dyes, pigments), fluorescent colorants, mucous membrane control agents, anti-slip agents, penetrants and defoamers can be included. These additives can be low viscosity, for example, in an aqueous solution of 20% by mass, at a temperature of 50° C., a viscosity of more than 1cps and less than 60cps is shown, preferably a viscosity of more than 5cps and less than 55cps, more preferably a viscosity of more than 10cps and less than 50cps is shown, and more preferably a viscosity of more than 10cps and less than 45cps is shown.

[0050] The water- and oil-repellent agent of the present invention can also adopt the following embodiments.

[0051] (Embodiment containing polysaccharides other than modified starch) The water- and oil-repellent of the present invention may further contain polysaccharides other than modified starch (hereinafter also referred to simply as polysaccharides). The polysaccharides other than modified starch may be, for example, unmodified starch or unprocessed starch.

[0052] The polysaccharide preferably has a low viscosity, and specifically preferably exhibits a viscosity of 100 cps or less in a 20% by mass aqueous solution at a temperature of 50° C. From the viewpoint of improving water repellency and oil repellency, the polysaccharide preferably exhibits a viscosity of 80 cps or less in a 20% by mass aqueous solution at a temperature of 50° C., more preferably exhibits a viscosity of 60 cps or less, and particularly preferably exhibits a viscosity of 40 cps or less.

[0053] From the perspective of making the water- and oil-repellent agent of the present invention easier to apply on paper, the polysaccharide may have a viscosity of 1 cps or more, preferably 5 cps or more, and more preferably 10 cps or more in a 20 mass % aqueous solution at 50°C.

[0054] 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 be oligosaccharides formed by bonding more than 3 and less than 10 monosaccharides.

[0055] Polysaccharides may be acidic polysaccharides, neutral polysaccharides or alkaline polysaccharides. Acidic polysaccharides are generally polysaccharides having carboxyl groups (-COOH) and 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 amino groups (-NH2) and the like. A specific example of alkaline polysaccharides is chitosan.

[0056] Specific examples of polysaccharides include xanthan gum, caraway gum, guar gum, pectin, tamarind gum, carrageenan, chitosan, gum arabic, locust bean gum, cellulose, cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose, alginic acid, starch (also known as starch), agar, dextrin, and pullulan. The polysaccharide may be a substituted polysaccharide, and in particular, a polysaccharide in which the hydroxyl group is substituted.

[0057] From the perspective of improving water repellency and oil repellency, the polysaccharide can be starch. The starch can be plant starch. For example, starch includes rice starch, wheat starch, corn starch, potato starch, tapioca starch, sweet potato starch, red bean starch, mung bean starch, kudzu starch and chestnut starch.

[0058] (Embodiments including modified starches other than hydrophobically modified starches) The water- and oil-repellent of the present invention may further contain a modified starch other than the hydrophobically modified starch as the modified starch. That is, the water- and oil-repellent of the present invention may further contain a modified starch other than the hydrophobically modified starch in addition to the hydrophobically modified starch.

[0059] Modified starches other than hydrophobic modified starches may have, for example, hydrophilic groups (e.g., hydroxyl, amino and / or carboxyl groups) as substituents. That is, the water- and oil-repellent agent of the present invention may also include modified starches having hydrophilic groups as modified starches. In one embodiment, modified starches other than hydrophobic modified starches may have not only hydrophilic groups but also hydrophobic groups (e.g., hydrocarbon groups having carbon numbers of 1 to 40, 2 to 40, or 3 to 30). Due to the presence of hydrophilic groups and hydrophobic groups, both water repellency and oil repellency can become very high.

[0060] As modified starches other than hydrophobically modified starch, for example, acetylated adipic acid cross-linked starch, acetylated oxidized starch, acetylated phosphate cross-linked starch, acetic acid starch, oxidized starch, hydroxyalkylated starch, hydroxyalkylated phosphate cross-linked starch (for example, the number of carbon atoms in the alkyl group is 2 or more and 40 or 2 or more and 10 or less, especially 2 or 3), phosphate cross-linked starch, phosphorylated starch, phosphoric acid monoesterified phosphate cross-linked starch, acid-modified starch, alkali-treated starch, enzyme-treated starch, bleached starch, cationized starch (for example, quaternized starch), and pregelatinized starch can be cited. Starch converted into low molecular weight dextrin by chemical or enzymatic methods can also be cited.

[0061] The modified starch other than the hydrophobically modified starch preferably has a low viscosity, and specifically preferably exhibits a viscosity of 70 cps or less in a 20% by mass aqueous solution at a temperature of 50° C. From the viewpoint of improving water repellency and oil repellency, the modified starch other than the hydrophobically modified starch exhibits a viscosity of 65 cps or less in a 20% by mass aqueous solution at a temperature of 50° C., more preferably exhibits a viscosity of 60 cps or less, and particularly preferably exhibits a viscosity of 55 cps or less.

[0062] From the perspective of making the water- and oil-repellent agent of the present invention easier to apply on paper, the modified starch other than the hydrophobic modified starch can exhibit a viscosity of 1 cps or more, preferably 5 cps or more, and more preferably 10 cps or more in a 20 mass % aqueous solution at a temperature of 50°C.

[0063] From the perspective of improving water repellency and oil repellency, the modified starch other than the hydrophobic modified starch can be a hydroxyalkylated starch. The carbon number of the alkyl group of the hydroxyalkylated starch can be preferably more than 2 and less than 40, more preferably more than 2 and less than 10, and particularly preferably 2 or 3. Specifically, the modified starch other than the hydrophobic modified starch can be a hydroxyethylated modified starch. That is, the water and oil repellent of the present invention can further contain a hydroxyethylated modified starch.

[0064] In a certain embodiment, the ratio of modified starch other than the hydrophobic modified starch in the modified starch contained in the water- and oil-repellent agent of the present invention may be less than 40% by mass, preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and further preferably 3% by mass or less, and it is particularly preferred that the modified starch contained in the water- and oil-repellent agent of the present invention may not contain modified starch other than the hydrophobic modified starch.

[0065] <Purpose> Water- and oil-repellent agent of the present invention can be used as external treatment agent (surface treatment agent) or internal treatment agent.Handle the goods gained with water- and oil-repellent agent and have high water repellency and / or high oil repellency.Therefore, water- and oil-repellent agent can be used as water- and / or oil-repellent agent.In addition, water- and oil-repellent agent also can be used as the component of antifouling agent, oil-resistant agent, stain remover, stripping agent or releasing agent or these preparations.

[0066] <Water and oil repellent paper> The water- and oil-repellent agent of the present invention can be used for treating paper (e.g., surface treatment). That is, the water- and oil-repellent agent of the present invention can be a water- and oil-repellent agent for treating the surface of paper. By treating paper with the water- and oil-repellent agent of the present invention, water- and oil-repellent paper can be obtained.

[0067] The water- and oil-repellent agent can be applied to paper by conventional known methods. For example, an internal addition treatment method can be adopted in which the water- and oil-repellent agent of the present invention is added to the paper pulp before papermaking, or an external addition treatment method can be adopted in which the water- and oil-repellent agent of the present invention is applied to the paper after papermaking.

[0068] The treatment method of water- and oil-repellent agent of the present invention is preferably an external addition treatment method. As an external addition treatment method, a sizing machine, coating (such as a gate roller coater, Bill blade coater (bill blade coater), rod coater, etc.), spraying device, etc. can also be adopted. The water- and oil-repellent agent can be dispersed in an organic solvent or water for dilution, and the method of being attached to the surface of the treated object and drying by known methods such as dip coating, spraying, foam coating, etc. can be adopted.

[0069] The sizing machine of the external addition treatment method is classified as follows according to the coating method. The coating method of one embodiment is to supply a coating liquid (i.e., sizing liquid) to the paper through the kneading portion formed between two rubber rollers, forming a coating liquid accumulation portion called an accumulation portion, so that the paper passes through the coating liquid accumulation portion, and the so-called accumulation type double roller sizing machine is coated with sizing liquid on both sides of the paper. Other coating methods include a gate roller type and a rod-type metallized sizing machine that applies sizing liquid through a surface transfer mold. In the accumulation type double roller sizing machine, the sizing liquid is easy to penetrate into the inside of the paper, and in the surface transfer mode, the sizing liquid component is easy to accumulate on the surface of the paper. Compared with the accumulation type double roller sizing machine, the coating layer of the surface transfer mode is more likely to accumulate on the surface of the paper, and the water-repellent and oil-repellent layer formed on the surface is more than the accumulation type double roller sizing machine. In the present invention, even in the case of using the former accumulation type double roller sizing machine, water-repellent and oil-repellent properties can be brought to the paper. The paper treated in this way exhibits excellent water and oil repellency after simple drying at room temperature or elevated temperature and subsequent heat treatment at a temperature up to 300°C, for example 200°C, and particularly at a temperature range of above 80°C and below 180°C, depending on the properties of the paper.

[0070] As the processing method of paper of the present invention, a method can be adopted in which the water-repellent and oil-repellent of the present invention is externally added to paper in an online manner. That is, it can be a processing method that the manufacturing process of paper and the coating process are integrated into one (in other words, continuously). For example, as the processing method of paper of the present invention, it can be that the paper stock slurry is supplied to the papermaking machine net portion for dehydration, and then the pulp water is squeezed out in the pressing section, and then the product after squeezing the water is passed through the drying section for drying, and a base paper for coating is obtained, and then the base paper for coating is coated with the water-repellent and oil-repellent through the coating machine head, and the base paper after coating is passed through the drying section for drying after completion of coating.

[0071] The water- and oil-repellent agent of the present invention can be used for gypsum board base paper, coated base paper, medium-quality paper, general base paper and core, neutral pure white roll paper, neutral base paper, anti-rust base paper and metal laminated paper, kraft paper, etc. In addition, it can also be used for 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.

[0072] The paper treated by the water- and oil-repellent agent of the present invention can be a container that can be made of paper, a molded body (such as a pulp mold) that can be made of paper, etc. For example, preferably a food packaging material and a food container. Paper can be manufactured by a known papermaking method in the past.

[0073] As the pulp raw material for paper, any of bleached or unbleached chemical pulp such as kraft pulp or sulfite pulp, bleached or unbleached high-yield pulp such as ground wood pulp, mechanical pulp or thermomechanical pulp, and waste paper pulp such as waste newspaper, waste magazine paper, waste corrugated paper or waste deinked paper can be used. In addition, a mixture of the above pulp raw materials and synthetic fibers such as asbestos, polyamide, polyimide, polyester, polyolefin, polyvinyl alcohol, etc. can also be used.

[0074] Sizing agents may be added to improve the water resistance of paper. Examples of sizing agents include cationic sizing agents, anionic sizing agents, and rosin-based sizing agents (e.g., acidic rosin-based sizing agents and neutral rosin-based sizing agents). The amount of sizing agent may be greater than 0.01% by mass and less than 5% by mass relative to the pulp.

[0075] As required, as a conventional papermaking preparation, carboxymethyl cellulose, polyamide polyamine-epichlorohydrin resin and other paper strength enhancers, flocculants, fixing agents, yield rate improvers, dyes, fluorescent dyes, mucous membrane control agents, defoamers and other additives used in papermaking can also be used in paper. As required, polyvinyl alcohol, glucose, dyes, coating pigments, anti-slip agents, etc. can be used, and water and oil repellents are applied on paper using a sizing machine, a gate roller coater, a Bill blade coater, a calender, etc. As an additive, polyvinyl alcohol or glucose is preferably used. By using polyvinyl alcohol or glucose together with polysaccharides, high water and oil repellency can be achieved. As the polyvinyl alcohol of papermaking preparation, relative to 100 mass parts of polysaccharides, its consumption can be more than 1 mass part, less than 1000 mass parts, more than 2 mass parts, less than 200 mass parts, more than 3 mass parts, less than 100 mass parts and more than 5 mass parts, less than 50 mass parts, particularly can be more than 10 mass parts, less than 40 mass parts.

[0076] 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 modified starch in the water-repellent and oil-repellent layer can be 6.0 g / m 2 Below, preferably 0.02g / m 2 Above, 6.0g / m 2 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, 4.0g / m 2 The content of the water- and oil-repellent agent in the water- and oil-repellent layer may be the solid component content (eg, the content of modified starch) contained in the water- and oil-repellent agent.

[0077] In the case of external addition, the hydrophobically modified starch contained in the water- and oil-repellent layer may be 0.01 g / m 2 Above, 6.0g / m 2 Below, preferably 0.1g / m 2 Above, 4.5g / m 2 Below, more preferably 0.2g / m 2 Above, 4.0g / m 2 Below, particularly preferably 0.3 g / m 2 Above, 3.5g / m 2 the following.

[0078] In the case of external addition, the modified starch other than the hydrophobic modified starch contained in the water-repellent and oil-repellent layer may be 0.01 g / m 2 Above, 2.0g / m 2 Below, preferably 0.1g / m 2 Above, 1.5g / m 2 Below, more preferably 0.1g / m 2 Above, 1.0g / m 2 the following.

[0079] The water- 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 in accordance with JISP8117 (2009). The higher the air permeability, the higher the gas barrier property, and it is difficult for not only gases such as oxygen but also moisture (including water vapor) to penetrate.

[0080] Example Hereinafter, the water- and oil-repellent agent of the present invention will be described in examples, but the present invention is not limited to the following examples.

[0081] The test methods used below are described below.

[0082] Viscosity measurement The viscosity was measured using a B-type viscometer. The viscosity measurement was carried out under the conditions of a rotation speed of 60 rpm and a temperature of 50° C., and a No. 2 rotor was used. The B-type viscometer used was a digital viscometer manufactured by Blookfield.

[0083] Oil resistance test (practical oil test) Water- and oil-repellent paper on 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 degree of smudging was observed.

[0084] According to the degree of fading on the back side, the rating values ​​are set as follows.

[0085] 5: 0~5% 4: 6-20% 3: 21-50% 2: 51~75% 1: 76~100% Water absorption (Cobb value) evaluation The water absorption (Cobb value) was measured in accordance with JIS P 8140:1998.

[0086] Place the paper substrate on a hard platen surface that has been processed into a smooth surface on one side, and fix a metal cylinder with an inner diameter of 112.8mm on the surface of the substrate with a clamp. Then, pour water into the cylinder until the water depth in the cylinder reaches 10mm. Calculate the weight of water absorbed within 1 minute from the beginning of contact between the water and the paper substrate. Convert the obtained value to weight per square meter (gsm) to calculate the water absorption (Cobb value).

[0087] Breathability The air permeability (air resistance) of the bottom of a paper container molded into a container shape was measured using an automatic Gurley tester (product No. 323-AUTO, ventilation hole diameter 28.6±0.1 mm) manufactured by Yasuda Seiki Co., Ltd. in accordance with JISP8117 (2009).

[0088] Viscosity measurement of 20 mass % aqueous solution of octenylsuccinic acid-modified starch A predetermined amount of octenyl succinic acid modified starch-1 was dissolved in water to prepare an aqueous solution having a concentration of 20 mass % of octenyl succinic acid modified starch. The viscosity of the aqueous solution was measured. Octenyl succinic acid modified starch-2, octenyl succinic acid modified starch-3 and ortho-hydroxyethylated modified starch were also prepared into 20 mass % aqueous solutions and the viscosity was measured. The viscosity measurement results are shown in Table 1.

[0089] [Table 1] [Example 1] (Preparation of base paper) As wood pulp, a pulp having a mass ratio of LBKP (bleached kraft pulp of broadleaf trees) to NBKP (bleached kraft pulp of coniferous trees) of 60% by mass and 40% by mass, and a pulp freeness of 400 ml (Canadian Freeness) was prepared, to which a wet paper strength agent was added so that the solid content concentration was 0.5% by mass relative to the dry pulp, and the paper density was 0.58 g / cm using a Fourdrinier papermaking machine. 3 Basis weight 48g / m 2The paper was used as the base paper for external addition treatment (size press treatment). The base paper's oil resistance (practical oil test) rating was 1. The base paper's water absorption (Cobb value) was 65. The base paper's air permeability was 250 seconds. (Manufacture of octenylsuccinic acid modified starch) In a flask containing 400 parts of water, 20 parts of corn starch were gradually added in small amounts at a time under vigorous stirring at a temperature of 25°C, and then dilute hydrochloric acid was added and stirred until the pH value reached below 4.

[0090] The aqueous solution is dried at a temperature of about 70 to 90° C. until the moisture content reaches below 7%, and then baked at a temperature of 160° C. until a predetermined viscosity is reached, thereby obtaining low-viscosity corn starch.

[0091] 100 parts of the obtained low-viscosity corn starch were gradually added in small amounts to a flask containing 120 parts of water under stirring, and then the pH value was neutralized with a 2% sodium hydroxide aqueous solution.

[0092] Next, while maintaining the pH at 7.5 to 8.0, 4 parts of octenylsuccinic anhydride were added, and the mixture was reacted at a temperature of about 30 to 40° C. for 5 hours.

[0093] After the reaction, the mixture was neutralized with dilute sulfuric acid and then washed several times with 300 parts of water.

[0094] After the obtained solid component is dried, it is ground into fine powder to obtain sodium octenyl succinate starch as octenyl succinic acid modified starch. By adjusting the baking time at 160° C., sodium octenyl succinate starch 1 to 3 with different desired viscosities are obtained.

[0095] (Preparation of water- and oil-repellent paper) The water- and oil-repellent agent was adjusted to 20% by mass of octenyl succinic acid modified starch-1, and after being treated with a size press, it was dried with a drum dryer to obtain a water- and oil-repellent paper (processed paper). The viscosity of the water- and oil-repellent agent was 45 cps. The coating amount of the obtained water- and oil-repellent paper was 3.2 g / m 2 The obtained water- and oil-repellent paper was used as test paper, and oil resistance test (practical oil test), water absorption (Cobb value) evaluation and air permeability evaluation were carried out. The evaluation results are shown in Table 2. The size press treatment described in this example (using a size press made by Mathis Company) refers to a so-called liquid accumulation type double-roll size press treatment in which a water- and oil-repellent agent is accumulated between the rolls and the base paper is passed through the water- and oil-repellent agent between the rolls at an optional roll speed and kneading pressure.

[0096] [Example 2] The same treatment as in Example 1 was performed except that octenyl succinic acid-modified starch-2 was used. The solid content coating amount of octenyl succinic acid-modified starch-2 on the obtained water- and oil-repellent paper was 3.0 g / m 2 The viscosity of the water- and oil-repellent agent was 25 cps. The evaluation results are shown in Table 2.

[0097] [Example 3] The same treatment as in Example 1 was performed except that the octenyl succinic acid modified starch-1 was replaced with 17% by mass of octenyl succinic acid modified starch-2 and 3% by mass of hydroxyethylated modified starch. The total coating amount of the solid content of the octenyl succinic acid modified starch-2 and hydroxyethylated modified starch of the obtained water- and oil-repellent paper was 3.8 g / m 2 The viscosity of the water- and oil-repellent agent was 45 cps. The evaluation results are shown in Table 2.

[0098] [Example 4] The same treatment as in Example 1 was performed except that the octenyl succinic acid modified starch-1 was replaced with 15% by mass of octenyl succinic acid modified starch-2 and 5% by mass of hydroxyethylated modified starch. The total coating amount of the solid content of the octenyl succinic acid modified starch-2 and hydroxyethylated modified starch of the obtained water- and oil-repellent paper was 3.8 g / m 2 The viscosity of the water- and oil-repellent agent was 65 cps. The evaluation results are shown in Table 2.

[0099] [Comparative Example 1] The same treatment as in Example 1 was performed except that the content of octenyl succinate-modified starch-3 was adjusted to 15% by mass instead of octenyl succinate-modified starch-1. The coating amount of the solid content of octenyl succinate-modified starch-3 on the obtained water- and oil-repellent paper was 2.4 g / m 2 The viscosity of the water- and oil-repellent agent was 80 cps. The evaluation results are shown in Table 2.

[0100] [Comparative Example 2] The same treatment as in Example 1 was performed except that octenyl succinic acid modified starch-1 was replaced with octenyl succinic acid modified starch C at 20 mass %. The viscosity of the water- and oil-repellent agent was 390 cps. Since the viscosity of the water- and oil-repellent agent was large, the paper could not be treated with the water- and oil-repellent agent. The evaluation results are shown in Table 2.

[0101] [Comparative Example 3] The same treatment as in Example 1 was performed except that octenyl succinic acid modified starch-1 was replaced with hydroxyethyl modified starch. The coating amount of the solid content of the hydroxyethyl modified starch of the obtained water- and oil-repellent paper was 3.4 g / m 2 The viscosity of the water- and oil-repellent agent was 65 cps. The evaluation results are shown in Table 2.

[0102] [Comparative Example 4] The same treatment as in Example 1 was performed except that octenyl succinic acid modified starch-1 was replaced with octenyl succinic acid modified starch-2 at 10% by mass and hydroxyethyl modified starch at 10% by mass. The total coating amount of the solid content of octenyl succinic acid modified starch-2 and hydroxyethyl modified starch in the obtained water- and oil-repellent paper was 3.6 g / m 2 The viscosity of the water- and oil-repellent agent was 131 cps. The evaluation results are shown in Table 2.

[0103] [Table 2] Based on the above results, it can be seen that the water- and oil-repellent agent of the present invention can provide excellent water- and oil-repellency to paper.

[0104] Industrial Applicability The water- and oil-repellent of the present invention can be suitably used for paper used for food containers and food packaging materials.

Claims

1. A water- and oil-repellent agent containing modified starch, characterized in that: The modified starch comprises a hydrophobic modified starch which exhibits a viscosity of 60 cps or less at a temperature of 50° C. in a 20% by mass aqueous solution, In the modified starch contained in the water- and oil-repellent agent, the ratio of the hydrophobic modified starch is 60% by mass or more.

2. The water- and oil-repellent agent according to claim 1, wherein The hydrophobically modified starch is alkenyl succinate-esterified starch.

3. The water- and oil-repellent agent according to claim 1 or 2, characterized in that The ratio of the hydrophobically modified starch is 75% by mass or more.

4. The water- and oil-repellent agent according to any one of claims 1 to 3, characterized in that The modified starch consists of the hydrophobically modified starch.

5. The water- and oil-repellent agent according to any one of claims 1 to 4, characterized in that The modified starch also includes modified starch having a hydrophilic group.

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

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

8. The water- and oil-repellent agent according to any one of claims 1 to 7, characterized in that The water- and oil-repellent agent further comprises an additive.

9. The water- and oil-repellent agent according to any one of claims 1 to 8, characterized in that The water- and oil-repellent agent is used for treating the surface of paper.

10. A water- and oil-repellent paper, characterized in that: The paper has a water- and oil-repellent layer formed of the water- and oil-repellent agent according to any one of claims 1 to 9 on its surface.

11. The water- and oil-repellent paper according to claim 10, characterized in that: The solid content of the water- and oil-repellent agent in the water- and oil-repellent layer is 6.0 g / m 2 the following.

12. A method for processing paper, characterized in that: The method comprises the step of treating paper with the water- and oil-repellent agent according to any one of claims 1 to 9 by external addition treatment.

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