Oil-resistant composition and oil-resistant substrate

Abstract

The purpose of this disclosure is to provide an oil-resistant composition that can impart high oil resistance without requiring a fluororesin, and an oil-resistant substrate using the same. [Solution] The oil-resistant composition of the present disclosure comprises water and emulsion particles dispersed in the water, having an average particle size of 0.60 μm or less, and is characterized in that the content of (meth)acrylic acid units in the ethylene-vinyl acetate polymer compound is 0 to 5% by mass. The oil-resistant substrate of the present disclosure comprises a substrate and an oil-resistant layer formed by drying the oil-resistant composition, which is disposed on the substrate.

Description

Technical Field

[0001] The present disclosure relates to an oil-resistant agent composition for forming an oil-resistant layer, and an oil-resistant substrate including the oil-resistant layer formed from the oil-resistant agent composition.

Background Art

[0002] An oil-resistant agent composition is used to impart a function of preventing oil penetration to a substrate by coating or filling it on a substrate such as paper. Oil-resistant paper having an oil-resistant layer obtained by coating an oil-resistant agent composition is widely used for packaging paper and paper plates for foods, particularly foods containing a large amount of oil such as fried chicken and fried potatoes.

[0003] Conventionally, as an oil-resistant agent constituting an oil-resistant agent composition, a fluororesin having excellent oil resistance has been widely used. However, there is concern that organic fluorine compounds (PFAS) generated when the fluororesin is heated may affect health and the environment (PFAS problem).

[0004] Therefore, in recent years, various non-fluorine-based oil-resistant agents and oil-resistant substrates using them have been developed as oil-resistant agents considering the environment and safety, replacing fluororesins.

[0005] For example, Patent Document 1 discloses an oil-resistant paper provided with at least one oil-resistant layer on at least one side of a paper support, wherein a polyethylene glycol dioleate having a polymerization degree of 6 to 10 is contained in the oil-resistant layer containing an oil-resistant agent selected from non-fluorine resins such as acrylic resins at 0.01 to 1.0% by mass based on the total solid content of the oil-resistant layer.

[0006] Patent Document 2 discloses an oil-resistant film containing a polyvinyl alcohol-based polymer (A) and polymer particles (B) containing a polymer having a glass transition temperature of 40 degrees or lower, wherein the content of the polymer particles (B) is 1 part by mass or more and less than 150 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol-based polymer (A).

[0007] Patent Document 3 discloses an oil-resistant paper characterized in that an oil-resistant layer is formed on at least one side of the base paper, the oil-resistant layer mainly consists of a polyvinyl alcohol-based resin and a styrene-acrylic copolymer resin, and the content of the polyvinyl alcohol-based resin is 15 to 50 parts by mass per 100 parts by mass of the styrene-acrylic copolymer resin. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2011-26745 [Patent Document 2] WO2020 / 130131 [Patent Document 3] Japanese Patent Publication No. 2021-80591 [Overview of the project] [Problems that the invention aims to solve]

[0009] The oil resistance of currently developed non-fluorinated oil-resistant compositions is not necessarily satisfactory compared to that of oil-resistant compositions containing fluorinated resins.

[0010] The purpose of this disclosure is to provide an oil-resistant composition that can impart high oil resistance without requiring a fluororesin, and an oil-resistant substrate using the same. [Means for solving the problem]

[0011] This disclosure is primarily based on the following: Water and, Emulsion particles containing an ethylene-vinyl acetate polymer compound, with an average particle size of 0.60 μm or less, dispersed in the aforementioned water, Includes, The ethylene-vinyl acetate polymer compound has a (meth)acrylic acid unit content of 0 to 5% by mass. This relates to oil-resistant compositions.

[0012] The oil-resistant composition of the present disclosure can form an oil-resistant base material provided with an oil-resistant film having high oil resistance by applying it to a base material such as paper and drying it.

[0013] In one or more preferred embodiments of the oil-resistant composition of the present disclosure, the total content of ethylene units and vinyl acetate units in the ethylene-vinyl acetate polymer compound is 95% by mass or more.

[0014] In one or more preferred embodiments of the oil-resistant composition of the present disclosure, the average particle diameter of the emulsion particles is 0.10 to 0.60 μm.

[0015] One or more preferred embodiments of the oil-resistant composition of the present disclosure further include a vinyl alcohol polymer compound.

[0016] One or more preferred embodiments of the oil-resistant composition of the present disclosure further include a vinyl alcohol polymer compound and paraffin wax.

[0017] Second, the present disclosure a base material, an oil-resistant layer formed by drying the oil-resistant composition of the present disclosure disposed on the base material, relates to an oil-resistant base material including

[0018] The oil-resistant base material of the present disclosure has high oil resistance.

[0019] In one or more preferred embodiments of the oil-resistant base material of the present disclosure, the base material is paper, fiber, woven fabric or non-woven fabric.

Advantages of the Invention

[0020] The oil-resistant composition of the present disclosure can form an oil-resistant layer having high oil resistance without requiring a fluororesin.

[0021] The oil-resistant base material of the present disclosure has high oil resistance.

Modes for Carrying Out the Invention

[0022] 1. Oil-resistant composition The oil-resistant composition of this disclosure comprises water and emulsion particles containing an ethylene-vinyl acetate polymer compound dispersed in the water.

[0023] The oil-resistant composition of this disclosure is characterized in that the average particle size of the emulsion particles is 0.60 μm or less, and the content of (meth)acrylic acid units in the ethylene-vinyl acetate polymer compound is 0 to 5% by mass. The oil-resistant layer formed by drying the oil-resistant composition of this disclosure having these characteristics can exhibit high oil resistance equivalent to that of an oil-resistant layer formed from an oil-resistant composition containing a fluororesin. When a composition is used in which emulsion particles containing an ethylene-vinyl acetate polymer compound with an average particle size larger than 0.60 μm, or with a (meth)acrylic acid unit content exceeding 5% by mass, is dispersed in water, it is difficult to form an oil-resistant layer with high oil resistance. Furthermore, the oil-resistant layer formed by drying the oil-resistant composition of this disclosure can have high water repellency.

[0024] The average particle size of the emulsion particles is 0.60 μm or less, and the lower limit is not particularly limited, but it is typically 0.10 to 0.60 μm, preferably 0.10 to 0.55 μm. The reason why a particularly oil-resistant layer can be obtained when the emulsion particles have an average particle size in this range is not entirely clear, but it is presumed that one reason is that the oil-resistant layer has a dense structure. In this disclosure, the average particle size of the emulsion particles refers to the 50% particle size in the volume-based particle size distribution obtained by measuring the oil-resistant composition using a laser diffraction particle size distribution analyzer. Specific examples of the laser diffraction particle size distribution analyzer include the apparatus described in the examples. Measurement of the emulsion particles can be performed at 20°C.

[0025] The ethylene-vinyl acetate polymer compound constituting the emulsion particles is a copolymer compound containing ethylene units and vinyl acetate units as constituent units, wherein the content of (meth)acrylic acid units may be 0 to 5% by mass relative to the total amount of the compound, preferably 0 to 3% by mass, more preferably 0 to 2% by mass, even more preferably 0 to 0.5% by mass, and most preferably 0% by mass. When the content of (meth)acrylic acid units in the ethylene-vinyl acetate polymer compound is within these ranges, the oil resistance of the oil-resistant layer obtained by drying the oil-resistant composition of this disclosure is particularly high. In this disclosure, "0% by mass" for the content of constituent units such as (meth)acrylic acid units in the polymer compound means that such constituent units are not included.

[0026] In this disclosure, (meth)acrylic acid units refer to constituent units derived from monomers selected from acrylic acid and methacrylic acid and their derivatives, such as acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, acrylamide, and methacrylamide. Examples of acrylic acid esters or methacrylic acid esters include methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, glycidyl acrylate, or glycidyl methacrylate. Examples of acrylamide or methacrylamide include N-methylolacrylamide, N-methylolmethacrylamide, N-butoxymethylacrylamide, or N-butoxymethylmethacrylamide. The content of (meth)acrylic acid units in the ethylene-vinyl acetate polymer compound refers to the total content of (meth)acrylic acid units relative to the ethylene-vinyl acetate polymer compound.

[0027] The ethylene-vinyl acetate polymer compound contains at least ethylene units and vinyl acetate units, may contain (meth)acrylic acid units within the above range, and may further contain other constituent units. The other constituent units may be derived from monomers polymerizable with ethylene and vinyl acetate. Examples of monomers polymerizable with ethylene and vinyl acetate include one or more selected from the following: alkyl vinyl esters other than vinyl acetate, such as vinyl butyrate, vinyl propionate, vinyl pivalate, vinyl laurate, vinyl isononanoate, and vinyl versatate; vinyl halides, such as vinyl chloride and vinyl bromide; vinylides, such as vinylidene chloride; vinyl compounds, such as vinylphosphonic acid, vinyl sulfonic acid, and their salts; aromatic vinyl compounds, such as styrene, α-methylstyrene, and chlorostyrene; α,β-unsaturated dicarboxylic acid compounds, such as maleic acid, maleic anhydride, and itaconic acid; nitrile compounds, such as (meth)acrylonitrile; conjugated diene compounds, such as butadiene and isoprene; and allyl compounds, such as allyl sulfonate, diallyl phthalate, triallyl cyanurate, and triallyl isocyanurate.

[0028] The ethylene-vinyl acetate polymer compound preferably consists mainly of ethylene units and vinyl acetate units. From the viewpoint of oil resistance, the total content of ethylene units and vinyl acetate units in the ethylene-vinyl acetate polymer compound can preferably be 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 97% by mass or more, more preferably 98% by mass or more, more preferably 99.5% by mass or more, and can also be 100% by mass.

[0029] In the ethylene-vinyl acetate polymer compound, the ratio of ethylene units to vinyl acetate units may preferably include 3% to 40% by mass of ethylene units and the remaining amount of vinyl acetate units, relative to the total amount of ethylene units and vinyl acetate units. The ratio of ethylene units to vinyl acetate units in the ethylene-vinyl acetate polymer compound can be adjusted as appropriate depending on the purpose.

[0030] The emulsion particles can be formed by emulsion polymerization of the ethylene-vinyl acetate polymer compound in water containing an emulsifier. Therefore, the emulsion particles may further contain an emulsifier. The emulsifier can be one or more selected from surfactants and protective colloids. Nonionic surfactants or anionic surfactants are preferred. Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene phenyl ethers, polyoxyethylene polyoxypropylene condensates, polyoxyalkylene fatty acid esters, and polyoxyalkylene sorbitan fatty acid esters. Examples of anionic surfactants include alkyl sulfate salts, alkylbenzene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, polyoxyalkylene alkyl sulfates, and polyoxyalkylene alkyl phosphate esters. Examples of protective colloids include polyvinyl alcohol, partially saponified polyvinyl alcohol, methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose fibrous derivatives. The emulsifier content in the solids of the emulsion particles can typically be 10% by mass or less.

[0031] Specific methods for producing the emulsion particles include mixing vinyl acetate and an emulsifier, along with other monomers and pH adjusters as needed, in water, then heating the resulting mixture to approximately 30-80°C under a nitrogen atmosphere, replacing the atmosphere with ethylene, and pressurizing it to approximately 0.1-10 MPa, preferably 1-7 MPa, while polymerizing it with a radical initiator and, as needed, additional vinyl acetate, other monomers, chain transfer agents, etc. Examples of radical initiators include oxidizing agents such as hydrogen peroxide, potassium persulfate, sodium persulfate, ammonium persulfate, and tert-butyl hydroperoxide, either alone or in redox systems combining reducing agents such as L- and D-ascorbic acid, sulfites, longalite, and ferrous sulfate with oxidizing agents. Examples of pH adjusting agents include acids and their salts such as hydrochloric acid, phosphoric acid, acetic acid, succinic acid, and carbonic acid; and bases such as alkali metal hydroxides, aqueous ammonia, and amines. Examples of chain transfer agents include mercaptans.

[0032] The oil-resistant composition of this disclosure more preferably further comprises a vinyl alcohol-based polymer compound. Vinyl alcohol-based polymer compounds such as polyvinyl alcohol are known to provide beneficial functions such as improving the surface strength, abrasion resistance, smoothness, paper gloss, and printability of a substrate when applied to it, but a film formed by this alone may not have sufficient oil resistance (see Comparative Example 16). According to the oil-resistant composition of this disclosure comprising emulsion particles and a vinyl alcohol-based polymer compound in combination, it is possible to form an oil-resistant layer that contains a vinyl alcohol-based polymer compound and has high oil resistance. Furthermore, according to one embodiment of the oil-resistant composition of this disclosure comprising emulsion particles and a vinyl alcohol-based polymer compound in combination, it is possible to form an oil-resistant layer that is not sticky (see Examples 1 to 4).

[0033] As the vinyl alcohol polymer compound, polyvinyl alcohol, particularly fully saponified polyvinyl alcohol with a degree of saponification of 95 mol% or more, is preferred. Vinyl alcohol polymer compounds, especially polyvinyl alcohol, with an average degree of polymerization of, for example, 300 to 3000, preferably 1500 to 2500, can be suitably used.

[0034] The content of the vinyl alcohol-based polymer compound in the oil-resistant composition of this disclosure, relative to 100 parts by mass (on a solid content basis) of the emulsion particles, is preferably 3 parts by mass or more and 35 parts by mass or less, more preferably 5 parts by mass or more and 30 parts by mass or less, and particularly preferably 8 parts by mass or more and 27 parts by mass or less.

[0035] The oil-resistant composition of this disclosure may contain a vinyl alcohol-based polymer compound dissolved in water. The oil-resistant composition of this disclosure, which contains emulsion particles dispersed in water and a vinyl alcohol-based polymer compound dissolved in water, can be prepared by mixing an aqueous solution prepared by dissolving the vinyl alcohol-based polymer compound in heated water and then allowing it to cool to 40°C or below, preferably to room temperature, with an aqueous suspension of the emulsion particles.

[0036] The oil-resistant composition of this disclosure more preferably further comprises paraffin wax in addition to the vinyl alcohol polymer compound. As described above, an oil-resistant layer formed using the oil-resistant composition of this disclosure, which contains a combination of emulsion particles and a vinyl alcohol polymer compound, has high oil resistance and functions due to the vinyl alcohol polymer compound, such as suppression of stickiness. By further combining it with paraffin wax, the water repellency of the oil-resistant layer can be further enhanced.

[0037] Paraffin wax is mainly composed of linear hydrocarbons (normal paraffins), but in this disclosure, modified paraffin waxes such as carboxylated paraffin wax and acrylonitrile-modified paraffin wax can also be used. The paraffin wax that can be used in this disclosure preferably has a melting point of 40°C or higher and 70°C or lower.

[0038] The oil-resistant composition of the present disclosure, comprising a vinyl alcohol polymer compound and paraffin wax, preferably contains 3 to 35 parts by mass of the vinyl alcohol polymer compound and 0.1 to 3 parts by mass of paraffin wax per 100 parts by mass of the emulsion particles (on a solid content basis), more preferably contains 8 to 27 parts by mass of the vinyl alcohol polymer compound and 0.1 to 3 parts by mass of paraffin wax, and more preferably contains 8 to 27 parts by mass of the vinyl alcohol polymer compound and 0.4 to 2 parts by mass of paraffin wax.

[0039] The oil-resistant compositions of this disclosure may contain paraffin wax as fine particles dispersed in water. The paraffin wax fine particles may be emulsified and dispersed in water with an emulsifier.

[0040] The oil-resistant composition of this disclosure may be provided as a suspension adjusted to a suitable amount, for example, 10% by mass or more and 60% by mass or less of solids content.

[0041] The oil-resistant compositions of this disclosure may further contain compounding agents such as defoamers, foaming agents, thickeners, viscosity modifiers, fillers, flame retardants, and pigments.

[0042] 2.Oil-resistant base material The oil-resistant substrates disclosed herein are Substrate and An oil-resistant layer formed by drying the oil-resistant composition of the present disclosure, disposed on the substrate, Includes.

[0043] The oil-resistant substrate of this disclosure has high oil resistance due to the oil-resistant layer. The oil-resistant substrate of this disclosure can be used in applications where oil resistance is required depending on the type of substrate.

[0044] Examples of the aforementioned base material include paper, fibers, woven fabrics, or nonwoven fabrics.

[0045] The oil-resistant substrate of this disclosure, which is made of paper, can be used as packaging material that requires oil resistance, such as packaging paper for oily products like food, and paper plates.

[0046] The oil-resistant substrate of this disclosure, wherein the substrate is a fiber, woven fabric, or nonwoven fabric, can be used as a material for textile products that require oil resistance, such as work clothes, tents, umbrellas, and rainwear.

[0047] The method for forming an oil-resistant layer from the oil-resistant composition of this disclosure is not particularly limited. For example, an oil-resistant layer can be formed on a substrate by applying the oil-resistant composition of this disclosure onto a substrate using a coating machine or the like and drying it. Alternatively, an oil-resistant substrate having an oil-resistant layer can be formed by applying the oil-resistant composition of this disclosure onto a support and drying it, and then laminating the oil-resistant layer on the support onto a substrate.

[0048] The oil-resistant layer only needs to be placed on the necessary parts of the substrate; it is not required to be placed on all surfaces of the substrate.

[0049] The method for drying the oil-resistant composition of this disclosure to form an oil-resistant layer is not particularly limited. For example, the oil-resistant composition of this disclosure can be heated and dried at a temperature of 60°C to 160°C for a period of 1 minute to 10 minutes under conditions that allow water to volatilize. Heat drying can be carried out using, for example, hot air, infrared rays, a heating cylinder, or a combination thereof.

[0050] Oil-resistant substrates with an oil-resistant layer can be further improved in terms of oil and water resistance by, if necessary, conditioning and / or calendering treatment.

[0051] The amount of oil-resistant layer on the substrate after drying is not particularly limited, but for example, 0.5 g / m² is the solid content of the oil-resistant layer per unit area of ​​the region on the substrate surface where the oil-resistant layer is located. 2 More than 50g / m 2 Preferably 1 g / m 2 More than 30g / m 2 It can be the following: [Examples]

[0052] In the experiments below, "parts" and "%" refer to "parts by mass" and "% by mass," respectively, unless otherwise specified.

[0053] Examples of aqueous emulsion production Water-based emulsion (1) A solution containing 80 parts water, 10 parts vinyl acetate, 0.3 parts sodium vinyl sulfonate, 7 parts of the surfactant "Latemul® 1135S-70" and 3 parts of "Latemul® 1108" (both manufactured by Kao Corporation), 0.003 parts ferrous sulfate heptahydrate, and 0.1 parts acetic acid was added to a pressure vessel. Next, the pressure vessel was purged with nitrogen gas, the temperature inside the vessel was raised to 50°C, and then pressurized to 4.0 MPa with ethylene. Then, 0.6 parts sodium persulfate and 0.2 parts sodium erythorbate were added to the pressure vessel to initiate polymerization. Subsequently, after confirming that the liquid temperature inside the pressure vessel had risen, an aqueous solution containing 0.3 parts sodium vinyl sulfonate and 110 parts vinyl acetate were added over 4 hours, and ethylene was added over 3 hours to maintain a constant pressure of 4.0 MPa while keeping the liquid temperature inside the vessel at 50°C. When the residual vinyl acetate monomer content was less than 1%, the pressure vessel was cooled, unreacted ethylene gas was removed, and the product was extracted. An aqueous emulsion (1) of ethylene-vinyl acetate-vinyl sulfonic acid copolymer was obtained, with 78 parts vinyl acetate units, 22 parts ethylene units, 0.1 parts vinyl sulfonic acid units, a non-volatile content of 53%, a viscosity of 350 mPa·s, and a glass transition temperature of -6°C.

[0054] Water-based emulsion (2) A solution containing 100 parts water, 40 parts vinyl acetate, 2 parts polyvinyl alcohol "Poval 22-88" (manufactured by Kuraray Co., Ltd., saponification degree 88 mol%, average degree of polymerization 1700), 3 parts of the surfactant "Latemul® 1135S-70" and "Latemul® 1108" (both manufactured by Kao Corporation), which mainly consist of polyoxyethylene alkyl ether, 2 parts of the surfactant "Pluronic® L-64" and "Pluronic® F-68" (both manufactured by ADEKA Corporation), which mainly consist of polyoxyethylene polyoxypropylene condensate, and 0.003 parts ferrous sulfate heptahydrate was added to a pressure vessel. Next, the pressure vessel was purged with nitrogen gas, the temperature inside the vessel was raised to 50°C, and then pressurized with ethylene to 1.5 MPa. Next, 0.4 parts of ammonium persulfate and 0.1 parts of a Longalit aqueous solution were added to the pressure vessel to initiate polymerization. Subsequently, after confirming that the liquid temperature in the pressure vessel had risen, an aqueous solution containing 90 parts of vinyl acetate and 2.7 parts of N-methylolacrylamide was added over 4 hours, and ethylene was added over 2 hours while maintaining the liquid temperature in the vessel at 50°C, so that the pressure remained constant at 1.4 MPa. When the residual vinyl acetate monomer was less than 1%, the pressure vessel was cooled, unreacted ethylene gas was removed, and the product was extracted. An aqueous emulsion (2) of ethylene-vinyl acetate-N-methylolacrylamide copolymer was obtained with 94 parts of vinyl acetate units, 4 parts of ethylene units, 2 parts of N-methylolacrylamide units, a non-volatile content of 50%, a viscosity of 900 mPa·s, and a glass transition temperature of 15°C.

[0055] Water-based emulsion (3) A solution containing 125 parts vinyl acetate, 1.5 parts polyvinyl alcohol "Poval 22-88" (manufactured by Kuraray Co., Ltd., saponification degree 88 mol%, average degree of polymerization 1700), 4.5 parts polyvinyl alcohol "Poval 05-88" (manufactured by Kuraray Co., Ltd., saponification degree 88 mol%, average degree of polymerization 500), and 0.003 parts ferrous sulfate heptahydrate was added to a pressure vessel. Next, the pressure vessel was purged with nitrogen gas, the temperature inside the vessel was raised to 60°C, and then pressurized to 4.6 MPa with ethylene. Then, 0.2 parts hydrogen peroxide and 0.3 parts sodium tartrate dihydrate were added to the pressure vessel to start polymerization. During polymerization, the liquid temperature inside the vessel was maintained at 60°C, and ethylene was added for 2 hours to maintain a constant pressure of 4.6 MPa. When the residual vinyl acetate monomer content was less than 1%, the pressure vessel was cooled, unreacted ethylene gas was removed, and the product was extracted. An aqueous emulsion (3) of ethylene-vinyl acetate copolymer was obtained, with a ratio of 20 parts ethylene units to 80 parts vinyl acetate units, a non-volatile content of 55%, a viscosity of 1400 mPa·s, and a glass transition temperature of 0°C.

[0056] Water-based emulsion (4) A solution containing 80 parts water, 30 parts vinyl acetate, 1.5 parts hydroxyethylcellulose, 0.7 parts of the surfactant "Latemul® 1135S-70" and "Latemul® 1108" (both manufactured by Kao Corporation), 0.003 parts ferrous sulfate heptahydrate, 0.06 parts sodium acetate, and 0.1 parts acetic acid was added to a pressure vessel. Next, the pressure vessel was purged with nitrogen gas, the temperature inside the vessel was raised to 50°C, and then pressurized to 5.0 MPa with ethylene. Then, 0.2 parts sodium persulfate and 0.2 parts sodium erythorbate were added to the pressure vessel to initiate polymerization. Subsequently, after confirming that the liquid temperature inside the pressure vessel had risen, 70 parts vinyl acetate was added over 3 hours, and ethylene was added over 3 hours while maintaining the liquid temperature inside the vessel at 50°C, so that the pressure remained constant at 5.4 MPa. When the residual vinyl acetate monomer content was less than 1%, the pressure vessel was cooled, and after removing the unreacted ethylene gas, the product was extracted. An aqueous emulsion (4) of ethylene-vinyl acetate copolymer was obtained, with a ratio of 77 parts vinyl acetate units to 23 parts ethylene units, a non-volatile content of 55%, a viscosity of 170 mPa·s, and a glass transition temperature of -5°C.

[0057] Water-based emulsion (5) A solution containing 85 parts water, 33 parts vinyl acetate, 0.5 parts hydroxyethylcellulose, 1 part of the surfactant "Latemul® 1135S-70" and 1 part of "Latemul® 1108" (both manufactured by Kao Corporation), 1 part sodium lauryl sulfate, 0.003 parts ferrous sulfate heptahydrate, 0.08 parts sodium acetate, and 0.06 parts acetic acid was added to a pressure vessel. Next, the pressure vessel was purged with nitrogen gas, the temperature inside the vessel was raised to 50°C, and then pressurized to 6.5 MPa with ethylene. Then, 0.2 parts sodium persulfate and 0.3 parts sodium erythorbate were added to the pressure vessel to initiate polymerization. Next, after confirming that the liquid temperature in the pressure vessel had risen, an aqueous solution containing 67 parts vinyl acetate, 9 parts 2-ethylhexyl acrylate, and 1.3 parts N-methylolacrylamide was added over 5 hours. Ethylene was added over 4 hours while maintaining the liquid temperature in the vessel at 50°C, so that the pressure remained constant at 6.5 MPa. When the residual vinyl acetate monomer was less than 1%, the pressure vessel was cooled, unreacted ethylene gas was removed, and the product was extracted. An aqueous emulsion (5) of ethylene-vinyl acetate-2-ethylhexyl acrylate copolymer was obtained, with 69 parts vinyl acetate units, 24 parts ethylene units, 6 parts 2-ethylhexyl acrylate units, 1 part N-methylolacrylamide units, a non-volatile content of 51%, a viscosity of 100 mPa·s, and a glass transition temperature of -22°C.

[0058] <Average particle size of aqueous emulsion> The 50% particle size in the volume-based particle size distribution obtained by measuring the aqueous emulsion using a laser diffraction particle size distribution analyzer (SALD-2300: manufactured by Shimadzu Corporation) was defined as the average particle size of the aqueous emulsion. The results are shown in Table 1.

[0059] [Table 1]

[0060] (Example 1) <Preparation of oil-resistant composition> In a separable flask equipped with a heating device, a stirring device, and a thermometer, 150 parts of water and 10 parts of fully saponified polyvinyl alcohol "Poval 28-98" (manufactured by Kuraray Co., Ltd., saponification degree 98 mol%, average degree of polymerization 1700) were charged. The mixture was heated to 90°C under stirring and stirred for 60 minutes while maintaining the temperature to dissolve the polyvinyl alcohol. After cooling to below 40°C, 170 parts of the aqueous emulsion (1) described in the production example were added, and 0.5 parts of paraffinic wax "Pertol RP-907N" (manufactured by Toho Chemical Industry Co., Ltd.) were mixed under stirring to obtain an oil-resistant composition with a solid content of 30%.

[0061] <Preparation of oil-resistant paper using oil-resistant agent compositions, and evaluation of oil resistance> Each oil-resistant composition contains approximately 10 g / m² of solids. 2 To achieve this, the base paper was coated using a bar coater and dried in a hot air dryer at 150°C for 2 minutes. After curing at room temperature for 24 hours, the oil resistance (Kit value) and practical oil resistance were measured according to the following method to evaluate oil resistance. The evaluation results are shown in Table 2.

[0062] • Oil resistance (Kit value) The oil-resistant layer side of the oil-resistant paper was measured according to the kit method (TAPPI-UM-557). A higher Kit value indicates higher oil resistance. The measured Kit values ​​are shown in Table 2, and the composition of the oil used to evaluate the Kit values ​​is shown in Table 3.

[0063] • Practical oil resistance Approximately 0.02 ml of canola oil was dropped onto the oil-resistant side of oil-resistant paper, and it was dried in a hot air dryer at 120°C for 15 minutes. The absorption into the paper after drying was visually inspected and evaluated according to the following criteria. The evaluation results are shown in Table 2. ○: No oil stains △: No oil seepage through the back, but oil stains present. ×: Oil seeped through to the back.

[0064] (Examples 2-6, Comparative Examples 1-12) Using the aqueous emulsions (2) to (5) described in the production example, fully saponified polyvinyl alcohol "Poval 28-98" (manufactured by Kuraray Co., Ltd., saponification degree 98 mol%), and paraffin wax "Pertol RP-907N" (manufactured by Toho Chemical Industry Co., Ltd.) in the mass ratios shown in Table 2, oil-resistant compositions were prepared in the same procedure as in Example 1, yielding the oil-resistant compositions of Examples 2 to 6 and Comparative Examples 1 to 12. Using these oil-resistant compositions, oil-resistant paper was prepared by coating and drying at the coating amounts shown in Table 1, as in Example 1, and the oil resistance was evaluated. The evaluation results are shown in Table 2.

[0065] (Comparative Examples 13-15) Oil-resistant paper was prepared using a commercially available oil-resistant composition and the same method as in Example 1, and its oil resistance was evaluated. The evaluation results are shown in Table 2. • Other company's product (1): SEIKOAT (registered trademark) T-EF 201, manufactured by Seikoh PMC Co., Ltd. • Other company's product (2): Unidyne (registered trademark) XP-8001, manufactured by Daikin Industries, Ltd. • Other company's product (3): Unidyne (registered trademark) TG-8111 (fluorine-based oil resistant agent) manufactured by Daikin Industries, Ltd.

[0066] (Comparative Example 16) Oil-resistant paper was prepared using fully saponified polyvinyl alcohol "POVAL 28-98" (manufactured by Kuraray Co., Ltd., saponification degree 98 mol%) in the same manner as in Example 1, and its oil resistance was evaluated. The evaluation results are shown in Table 2.

[0067] [Table 2]

[0068] [Table 3]

[0069] <Evaluation of water contact angle and stickiness of oil-resistant paper in Examples 1-6> In the following experiments, the water contact angle, an indicator of water repellency, and the stickiness of the oil-resistant layer surface were evaluated for the oil-resistant papers of Examples 1 to 6, which demonstrated high oil resistance as described above.

[0070] • Contact angle of the child Water was dropped onto the surface of the oil-resistant layer of oil-resistant paper, which was obtained by coating each oil-resistant composition with a contact angle meter (B100: manufactured by Asumi Giken Co., Ltd.) according to the droplet method, and the angle of the water droplet was measured after 5 seconds. A larger water contact angle indicates higher water repellency. The evaluation results are shown in Table 4.

[0071] Stickiness After curing the oil-resistant paper for 24 hours under conditions of 23°C and 50% humidity, the presence or absence of stickiness when touching the oil-resistant layer side of the paper with a finger was evaluated using a two-stage sensory evaluation. The evaluation results are shown in Table 4. 1: No stickiness 2: Slightly sticky

[0072] [Table 4] [Industrial applicability]

[0073] The oil-resistant composition and oil-resistant substrate of this disclosure can be used in applications where oil resistance is required, such as packaging materials and textile products.

Claims

1. Water and, Emulsion particles containing an ethylene-vinyl acetate polymer compound, with an average particle size of 0.60 μm or less, dispersed in the aforementioned water, Includes, The ethylene-vinyl acetate polymer compound contains 0 to 5% by mass of (meth)acrylic acid units. Oil-resistant composition.

2. The oil-resistant composition according to claim 1, wherein the total content of ethylene units and vinyl acetate units in the ethylene-vinyl acetate polymer compound is 95% by mass or more.

3. The oil-resistant composition according to claim 1, wherein the average particle size of the emulsion particles is 0.10 to 0.60 μm.

4. The oil-resistant composition according to claim 1, further comprising a vinyl alcohol-based polymer compound.

5. The oil-resistant composition according to claim 4, further comprising paraffin wax.

6. Substrate and An oil-resistant layer formed by drying the oil-resistant composition according to any one of claims 1 to 5, disposed on the substrate, Oil-resistant substrate containing [unspecified].

7. The oil-resistant substrate according to claim 6, wherein the substrate is paper, fiber, woven fabric or nonwoven fabric.

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