Paper Coating Agent

Abstract

To provide a new paper coating agent which can efficiently impart excellent oil resistance and water resistance to paper.SOLUTION: An aqueous composition contains (A) a copolymer containing an α,β-unsaturated carboxylic acid or its ester as a constitutional unit, and (B) a long chain fatty acid ester.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a paper coating agent, and to paper having the paper-tinging agent applied thereto, as well as to products using the paper. [Background technology]

[0002] Conventionally, in order to impart oil resistance and water resistance to paper (especially food packaging paper), for example, aluminum foil, film, etc. have been coated or laminated on one or both sides of the paperboard. However, these conventional methods require the application of multiple layers of coating, and require binders, sealants, etc. for lamination, resulting in poor work efficiency.

[0003] For example, in order to develop oil resistance, fluorine-based oil-resistant agents, particularly perfluorofluorine-based oil-resistant agents, are used. However, perfluorofluorine-based compounds generate perfluorooctanoic acid or perfluorosulfonic acid by heat treatment, and there are concerns about safety. For this reason, fluorine-based resins with improved safety are being developed, but they have insufficient oil resistance and remain unsafe. Furthermore, fluorine-based compounds repel printing ink due to their high oil resistance, and there are problems such as white spots occurring when gravure printing is performed on paper treated with them.

[0004] For example, polyvinyl alcohol resins are widely used as non-fluorine-based oil-resistant agents. Polyvinyl alcohol is a hydrophilic resin that forms a strong film, which is known to provide excellent oil resistance by preventing oil penetration. Acrylic and urethane emulsions are also known to have excellent oil resistance.

[0005] However, polyvinyl alcohol resins tend to foam during coating, which makes them prone to pinholes. In order to prevent pinholes from forming on the coating surface, it is necessary to defoam the coating by devising equipment or adding a defoaming agent. In addition, polyvinyl alcohol resins have the disadvantage that the oil attached to the coating surface spreads and causes poor appearance because the contact angle with oil is small, and that they are difficult to use in high humidity environments due to their poor water resistance. In addition, while acrylic and urethane resins have excellent oil resistance, they have poor water resistance and are concerned about absorbing water or dissolving in water. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 2970493 [Patent Document 2] Japanese Patent Application Publication No. 7-60905 Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have conducted research in order to develop a novel paper coating agent that can efficiently impart excellent oil resistance and water resistance to paper. [Means for solving the problem]

[0008] The present inventors have found that an aqueous composition containing (A) a copolymer having an α,β-unsaturated carboxylic acid or its ester as a constituent unit, and (B) a long-chain fatty acid ester may be useful as a coating agent that imparts excellent oil resistance and water resistance to paper, and have made further improvements.

[0009] The present disclosure includes, for example, the subject matter described in the following sections: Section 1. (A) a copolymer containing an α,β-unsaturated carboxylic acid or an ester thereof as a constituent unit, and (B) Long-chain fatty acid ester 1. An aqueous composition comprising: Section 2. The α,β-unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid; Item 2. The aqueous composition according to item 1, wherein the ester of an α,β-unsaturated carboxylic acid is an alkyl ester of an α,β-unsaturated carboxylic acid having 1 to 10 carbon atoms. Section 3. A copolymer containing an α,β-unsaturated carboxylic acid or an ester thereof as a constituent unit, Furthermore, it is a copolymer containing at least one of ethylene, propylene, butene, isobutene, butadiene, isoprene, and styrene as a constituent unit. Item 3. The aqueous composition according to item 1 or 2. Section 4. Ethylene / α,β-unsaturated carboxylic acid copolymer, and Montan Acid Ester 1. An aqueous composition comprising: Section 5. The ethylene / α,β-unsaturated carboxylic acid copolymer is A copolymer containing 8% by mass or more of α,β-unsaturated carboxylic acid. Item 5. The composition according to item 4. Section 6. Item 6. The composition according to item 4 or 5, comprising 0.1 to 200 parts by mass of a montanic acid ester per 100 parts by mass of the ethylene / α,β-unsaturated carboxylic acid copolymer. Section 7. Item 7. The composition according to any one of Items 4 to 6, wherein the montanic acid ester is an ester of montanic acid and ethylene glycol. Section 8. 8. The composition according to any one of items 1 to 7, wherein the α,β-unsaturated carboxylic acid is (meth)acrylic acid. Section 9. The copolymer and the ester are dispersed in the dispersion. The composition according to any one of items 1 to 8. Section 10. Item 10. The composition according to any one of items 1 to 9, which is a paper coating agent. Effect of the Invention

[0010] Provided is an aqueous composition that can efficiently impart excellent oil resistance and water resistance to paper. The composition is suitable as a paper coating agent. Also provided is paper (preferably food packaging paper) coated with the composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Each embodiment included in the present disclosure will be described in more detail below. The present disclosure preferably includes an aqueous composition capable of efficiently imparting oil resistance and water resistance to paper, the use of the aqueous composition as a paper coating agent, paper coated with the composition (preferably food packaging paper), etc., but is not limited thereto, and the present disclosure includes all that is disclosed in the present specification and that can be recognized by a person skilled in the art.

[0012] The composition included in the present disclosure is an aqueous composition, and contains (A) a copolymer containing an α,β-unsaturated carboxylic acid or its ester as a constituent unit, and (B) a long-chain fatty acid ester. In addition, the term "aqueous" here means that it contains an aqueous dispersion medium, and water or an aqueous solution is particularly preferred as the aqueous dispersion medium. In this specification, the composition may be referred to as the composition of the present disclosure. The composition of the present disclosure is preferably an aqueous dispersion. Note that the copolymer containing an α,β-unsaturated carboxylic acid or its ester as a constituent unit may be referred to as the copolymer (A), and the long-chain fatty acid ester may be referred to as the ester (B).

[0013] The copolymer (A) is a copolymer containing one or more α,β-unsaturated carboxylic acids as constituent units, and may be, for example, (i) a copolymer of one or more α,β-unsaturated carboxylic acids or their esters with one or more monomers other than α,β-unsaturated carboxylic acids or their esters, or (ii) a copolymer of two or more α,β-unsaturated carboxylic acids or their esters. Note that "two or more α,β-unsaturated carboxylic acids or their esters" includes the cases of only two or more α,β-unsaturated carboxylic acids, only two or more α,β-unsaturated carboxylic acid esters, and one or more α,β-unsaturated carboxylic acids and one or more α,β-unsaturated carboxylic acid esters.

[0014] Examples of α,β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid. Among these, (meth)acrylic acid (i.e., methacrylic acid and / or acrylic acid) is more preferred. Examples of α,β-unsaturated carboxylic acid esters include alkyl esters having 1 to 10 carbon atoms (1, 2, 3, 4, 5, 6, 7, 8, 9, or 10). The alkyl portion of the alkyl ester may be linear or branched. More specifically, examples of α,β-unsaturated carboxylic acid esters include methyl esters, ethyl esters, butyl (particularly n-butyl) esters, and 2-ethylhexyl esters. Examples of α,β-unsaturated carboxylic acid esters include 2-methylaminoethyl esters and hydroxyethyl esters (particularly 2-hydroxyethyl esters). Of these, esters of α,β-unsaturated carboxylic acids are more preferably methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and the like.

[0015] Examples of monomers other than the α,β-unsaturated carboxylic acid or its ester include ethylene, propylene, butene, isobutene, butadiene, isoprene, and styrene.

[0016] More specifically, the copolymer (A) preferably includes, for example, ethylene / α,β-unsaturated carboxylic acid or its ester copolymer, styrene / α,β-unsaturated carboxylic acid or its ester copolymer, etc. Among these, ethylene / α,β-unsaturated carboxylic acid copolymer is more preferred. More specifically, for example, ethylene / (meth)acrylic acid copolymer, styrene / (meth)acrylic acid ester copolymer, styrene / (meth)acrylic acid / (meth)acrylic acid ester copolymer, etc. are more preferred.

[0017] The copolymer (A) can be prepared by a known method or a method that can be easily derived from a known method. In addition, a commercially available product can be purchased and used. For example, examples of commercially available ethylene / α,β-unsaturated carboxylic acid copolymers include Primacol 5980, Primacol 5990 (manufactured by Dow Chemical Japan Co., Ltd.), Nucrel AN4221C, Nucrel N5130H, Nucrel N2060, Nucrel N2050H, and Nucrel N1560 (manufactured by Mitsui DuPont Polychemicals Co., Ltd.).

[0018] As the ethylene / α,β-unsaturated carboxylic acid copolymer, an ethylene / (meth)acrylic acid copolymer is particularly preferred.

[0019] The copolymer (A) is not particularly limited, but it is preferable that the carboxyl groups (derived from an α,β-unsaturated carboxylic acid) contained therein are appropriately neutralized.

[0020] Generally, when the carboxyl group of the copolymer (A) is in a free state, the hydrophilicity is relatively low, and when the carboxyl group is in a salt state, the hydrophilicity is relatively high. Therefore, by neutralizing with a base, the neutralized carboxyl group in the copolymer acts as an emulsifier, and an aqueous dispersion can be easily produced.

[0021] As the base for the neutralization, for example, ammonia, an organic amine, an alkali metal hydroxide, or the like is preferably used.

[0022] Examples of organic amines include methylamine, ethylamine, diethylamine, diethanolamine, and triethanolamine. Examples of alkali metal hydroxides include sodium hydroxide, potassium hydroxide, and lithium hydroxide. Ammonia can also be used in the form of ammonia gas or an aqueous ammonia solution. These bases can be used alone or in combination of two or more.

[0023] In the copolymer (A), 20 to 100% of the carboxyl groups contained therein are preferably neutralized, more preferably 35 to 100%, and even more preferably 40 to 70%. That is, the degree of neutralization of the copolymer (A) is preferably 20 to 100%, more preferably 35 to 100%, and even more preferably 40 to 70%. The upper or lower limit of the range (20 to 100%) may be, for example, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95%. For example, it may be 40 to 95%. The % is the mole % of the carboxyl group unit.

[0024] In addition, although not particularly limited, the copolymer (A) preferably has an α,β-unsaturated carboxylic acid content of, for example, 8% by mass or more, more preferably 8 to 50% by mass. The upper or lower limit of the range may be, for example, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, or 49% by mass. For example, it may be 9 to 49% by mass. The α,β-unsaturated carboxylic acid content here refers to the content of units derived from α,β-unsaturated carboxylic acid.

[0025] In particular, when the copolymer (A) is an ethylene / α,β-unsaturated carboxylic acid copolymer, the α,β-unsaturated carboxylic acid content is preferably 8 to 24% by mass in order to achieve a good balance between the non-polar properties derived from the ethylene units and the polar properties derived from the α,β-unsaturated carboxylic acid. The upper or lower limit of the range may be, for example, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, or 23% by mass. The range may be, for example, 18 to 23% by mass. When the α,β-unsaturated carboxylic acid content is 8% by mass or more, the dispersibility in the aqueous dispersion medium is further improved due to the non-polar properties derived from the ethylene units, and an excellent aqueous dispersion composition can be efficiently obtained. In addition, when the α,β-unsaturated carboxylic acid content is less than 24% by mass, the blocking resistance of the film (coating film) prepared when the obtained aqueous dispersion composition is used as a coating agent is further improved.

[0026] The method for preparing the aqueous composition containing the copolymer (A) is not particularly limited. For example, the copolymer (A) is dispersed in an aqueous dispersion medium while stirring at a temperature of 70 to 130°C (in the presence of a predetermined amount of base if necessary when neutralization is performed). By cooling the aqueous dispersion medium to room temperature while continuing stirring, an aqueous composition of the copolymer (A) (neutralized when a base is used) is obtained in the form of an aqueous dispersion.

[0027] Although not particularly limited, the average particle size of the copolymer (A) in the aqueous composition is, for example, preferably about 5 to 2000 nm, and more preferably about 10 nm to 1000 nm.

[0028] The content of the copolymer (A) in the composition of the present disclosure is preferably, for example, 5 to 50 mass%. The upper or lower limit of the range may be, for example, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, or 49 mass%. For example, the range may be 10 to 30 mass%.

[0029] The copolymer (A) can be used either individually or in combination of two or more.

[0030] The ester (B) is preferably an ester of a long-chain fatty acid and an alkyl alcohol.

[0031] Examples of long-chain fatty acids include linear or branched fatty acids having 8 to 30 carbon atoms (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30), and linear fatty acids are more preferred. The long-chain fatty acids may be saturated or unsaturated fatty acids, and saturated fatty acids are more preferred. More specifically, examples of long-chain fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, arachidonic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, or melissic acid, and montanic acid is particularly preferred.

[0032] The alkyl alcohol may be, for example, a linear or branched alkyl alcohol having 1 to 30 carbon atoms (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30), and preferably a linear alkyl alcohol. The alkyl alcohol is preferably a monohydric or dihydric alcohol.

[0033] The ester (B) can be used alone or in combination of two or more. Therefore, for example, a composition containing two or more esters of long-chain fatty acids and alkyl alcohols can also be used as the ester (B). For example, wax esters can be preferably used as the ester (B). Although not particularly limited, for example, jojoba oil can be preferably used as the wax ester.

[0034] As described above, montanic acid ester is one of the particularly preferred esters (B), and the montanic acid ester is particularly preferably a mono- or diester of montanic acid and glycol. More specifically, for example, an ester of montanic acid and ethylene glycol, propylene glycol, or butylene glycol is preferred, among which an ester of montanic acid and ethylene glycol is preferred, and a monoester of montanic acid and ethylene glycol is more preferred.

[0035] The ester (B) can be prepared by synthesis, for example, by a known method or a method that can be easily derived from a known method, or a commercially available product can be purchased and used. Examples of commercially available montanic acid esters include Saibinol A730T and A350T manufactured by Saiden Chemical Industry Co., Ltd., and BYK-498 manufactured by BYK-Chemie Co., Ltd. These can be used alone or in combination. Note that all of the commercially available products listed here are commercially available products in the form of a montanic acid ester (more specifically, a monoester of ethylene glycol and montanic acid) dispersed in water or an aqueous solution.

[0036] The ester (B) may be used as it is, or may be emulsified and dispersed in an aqueous dispersion medium, if necessary, using a small amount of a surfactant or the like, and used as an aqueous dispersion.

[0037] The content ratio of copolymer (A) and ester (B) in the composition of the present disclosure is preferably about 0.1 to 200 parts by mass of ester (B) per 100 parts by mass of copolymer (A). The upper or lower limit of the range is, for example, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112 , 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157 , 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, or 199 parts by mass. For example, the range may be 1 to 150 parts by mass or 5 to 100 parts by mass.

[0038] In the composition of the present disclosure, it is particularly preferable to use an ethylene / α,β-unsaturated carboxylic acid copolymer and a montanic acid ester as the copolymer (A) and the ester (B). When using this combination, it is particularly preferable to use the above content ratio.

[0039] The composition of the present disclosure may contain components other than the copolymer (A) and the ester (B) within a range that does not impair the effect. Examples of such other components include waxes other than the ester (B). Examples of such waxes include polyolefin waxes such as microcrystalline wax, polyethylene wax, carboxyl group-containing polyethylene wax, polypropylene wax, and ethylene-propylene copolymer wax, candelilla wax, rice wax, fatty acids such as stearic acid, fatty acid amides such as stearic acid amide, stearic acid bisamide, oleic acid amide, and palmitic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.

[0040] In addition, as described below, the aqueous composition of the composition of the present disclosure can be prepared, for example, by dispersing the copolymer (A) and the ester (B) in an aqueous dispersion medium, and the components contained in the aqueous dispersion medium may also be included in the composition of the present disclosure.

[0041] Such other components may be used alone or in combination of two or more.

[0042] Other components include, for example, pigments. Specific examples include inorganic pigments such as silica, calcium carbonate, kaolin clay, talc, titanium oxide, satin white, aluminum hydroxide, colloidal silica, and organic pigments such as plastic beads and starch particles. Although not particularly limited, the particle size of the pigment is preferably 1 to 12 μm. In addition to pigments, water-resistant agents, defoamers, dispersants, water-retaining agents, thickeners, lubricants, wetting agents, preservatives, antistatic agents, printability improvers, and the like may be used as appropriate.

[0043] The compositions of the present disclosure can be prepared, for example, by mixing an aqueous dispersion of copolymer (A) (optionally neutralized with a base) with ester (B) or an aqueous dispersion of ester (B).

[0044] The above-mentioned other components can be added after the mixing, or can be added in advance to any of the dispersions (preferably the aqueous dispersion of copolymer (A)) before the mixing.

[0045] In the present invention, the aqueous dispersion medium is generally ordinary tap water or deionized water, but for example, in order to further increase the stability of the aqueous dispersion medium, water whose viscosity has been adjusted by adding water-soluble resins such as polyvinyl alcohol, sodium polyacrylate, carboxymethyl cellulose, hydroxyethyl cellulose, etc. may be used. The aqueous dispersion medium may contain, in addition to the above-mentioned components, a defoamer, a viscosity adjuster, a fungicide, etc., within a range that does not impair the effects of the present invention. If necessary, an antioxidant, a slipping improver such as fatty acid amide or silicone oil, a surfactant, etc. may be blended.

[0046] The composition of the present disclosure can be preferably used as a coating agent for paper (preferably food packaging paper). The film (coating film) obtained by applying the composition of the present disclosure to paper (and drying as necessary) has excellent adhesion and heat seal strength. The composition of the present disclosure also has excellent coatability. For this reason, it can be used as (i) a coating agent for materials other than paper, such as steel plates and aluminum plates, (ii) various ink binders, (iii) a heat seal agent for plastic films such as polypropylene, polyethylene, and polyester, surface-treated paper, or aluminum foil, or (iv) a fiber treatment agent, etc. Furthermore, the film prepared from the composition of the present disclosure can impart water resistance and oil resistance to the surface of each material.

[0047] The method of applying the composition of the present disclosure to each material is not particularly limited, and can be, for example, coating. More specific coating methods of the composition of the present disclosure can be general coating methods, such as blade coater, roll coater, reverse roll coater, air knife coater, bar coater, curtain coater, lip coater, rod coater, die coater, gravure coater, and champ flex coater. For coating, for example, off-machine coater or on-machine coater can also be used.

[0048] In addition, in this specification, the term "comprising" includes "consisting essentially of" and "consisting of." In addition, the present disclosure includes all arbitrary combinations of the constituent features described in this specification.

[0049] In addition, the various characteristics (properties, structures, functions, etc.) described in each embodiment of the present disclosure above may be combined in any way to specify the subject matter included in the present disclosure. In other words, the present disclosure includes all subject matter consisting of all combinations of each combinable characteristic described in this specification. EXAMPLES

[0050] Hereinafter, the embodiments of the present disclosure will be described more specifically with reference to examples, but the embodiments of the present disclosure are not limited to the following examples.

[0051] Evaluation items and methods (1) Oil resistance High-quality paper (commercially available, basis weight 209g / m 2 A resin-containing aqueous dispersion was applied onto the paper using a bar coater so that the thickness of the film after drying would be approximately 12 μm. This was then dried at 80°C for 2 minutes using a hot air dryer, and the oil resistance was determined according to J-TAPPI Paper and Pulp Test Method No. 41:2000 (Paper and Paperboard - Oil Resistance Test Method Kit Method). (2) Water resistance The resin-containing aqueous dispersion was dried in a hot air dryer at 80° C. and molded into a 1 mm-thick sheet using a heat press at 130° C. The molded sheet was cut into a 2 cm square, and the cut test piece was immersed in pure water for 7 days. The weight increase rate (%) was calculated from the film weight before and after immersion using the following formula: Weight increase rate (%) = (weight after immersion - weight before immersion) / (weight before immersion) x 100

[0052] [Preparation Example 1 of Neutralized Ethylene / Acrylic Acid Copolymer] In a 500 ml separable flask equipped with a 50 mm diameter stirring blade, 112 g of ethylene / acrylic acid copolymer (product name: Primacol 5980i, manufactured by SK Global Chemical, acrylic acid content 20 mass%, melt flow rate 300 g / 10 min), 11.3 g of 28% ammonia water (equivalent to 60% neutralization), and 276.7 g of water as an aqueous dispersion medium were charged and heated under stirring. After the contents were heated to 95°C and stirred at that temperature for 4 hours, the contents were cooled to room temperature while continuing to stir, and an aqueous dispersion of ethylene / acrylic acid copolymer with a resin concentration of 28% and a median particle size of 100 nm was obtained.

[0053] Example 1 50 g of the aqueous dispersion of the ethylene / acrylic acid copolymer obtained in Production Example 1 (resin concentration: 28% by mass) was mixed and dispersed with 11.2 g of Saibinol A350T (manufactured by Saiden Chemical Industry Co., Ltd.), which is an aqueous dispersion of montanic acid ester (solid content: 25%), to obtain an aqueous dispersion of an ethylene-based resin. The obtained aqueous dispersion of an ethylene-based resin was evaluated according to the above-mentioned performance evaluation method, and the results are shown in Table 1.

[0054] Example 2 50 g of the aqueous dispersion of the ethylene / acrylic acid copolymer obtained in Production Example 1 (resin concentration: 28% by mass) was mixed and dispersed with 28 g of Saibinol A350T (manufactured by Saiden Chemical Industry Co., Ltd.), which is an aqueous dispersion of montanic acid ester (solid content: 25%), to obtain an aqueous dispersion of an ethylene-based resin. The obtained aqueous dispersion of an ethylene-based resin was evaluated according to the above-mentioned performance evaluation method, and the results are shown in Table 1.

[0055] Example 3 50 g of the aqueous dispersion of the ethylene / acrylic acid copolymer obtained in Production Example 1 (resin concentration: 28% by mass) was mixed and dispersed with 56 g of Saivinol A350T (manufactured by Saiden Chemical Industry Co., Ltd.), which is an aqueous dispersion of montanic acid ester (solid content: 25%), to obtain an aqueous dispersion of an ethylene-based resin. The aqueous dispersion of the ethylene-based resin obtained was evaluated according to the above-mentioned performance evaluation method, and the results are shown in Table 1. Saivinol A350T is a monoester of ethylene glycol and montanic acid.

[0056] Comparative Example 1 The aqueous dispersion of the ethylene / acrylic acid copolymer obtained in Production Example 1 (resin concentration: 28% by mass) was evaluated according to the above-mentioned performance evaluation method. The results are shown in Table 1.

[0057] Comparative Example 2 An acrylic emulsion, Neocryl A-2092 (manufactured by DSM Coating Resins), was evaluated according to the above-mentioned performance evaluation method, and the results are shown in Table 1.

[0058] Comparative Example 3 Neolet's R600 (manufactured by DSM Coating Resins), a urethane emulsion, was evaluated according to the above-mentioned performance evaluation method, and the results are shown in Table 1.

[0059] As shown in Table 1, the aqueous dispersions of the resins of Examples 1 to 3 (copolymers containing α,β-unsaturated carboxylic acid as a constituent unit) showed good oil and water resistance, with an oil resistance value (kit value) of 11 or more measured by the kit method and a water resistance of ±5%. On the other hand, Comparative Example 3, which did not contain a long-chain fatty acid ester (specifically, montanic acid ester), showed good water resistance of +1.8%, but poor oil resistance with an oil resistance value of 6. When an acrylic resin or a urethane resin was used, both had an oil resistance value of 12, which was excellent in oil resistance, but very poor water resistance.

[0060] [Table 1]

Claims

1. An aqueous composition comprising: (A) contains an α,β-unsaturated carboxylic acid or an ester thereof as a structural unit, Further, the copolymer contains at least one selected from the group consisting of ethylene, propylene, butene, isobutene, butadiene, isoprene, and styrene as a structural unit. (B) a long-chain fatty acid ester which is an ester of a linear or branched chain fatty acid having 8 to 30 carbon atoms and a linear or branched chain alkyl alcohol having 1 to 30 carbon atoms. Contains Contains 5 to 50 mass % of (A); and (B) is contained in an amount of 5 to 200 parts by mass per 100 parts by mass of (A); An aqueous composition which is a paper coating.

2. the α,β-unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid; 2. The aqueous composition according to claim 1, wherein the ester of an α,β-unsaturated carboxylic acid is an alkyl ester of an α,β-unsaturated carboxylic acid having 1 to 10 carbon atoms.

3. An aqueous composition comprising: Ethylene / α,β-unsaturated carboxylic acid copolymers, and Montan Acid Ester Contains Contains 5 to 50% by mass of an ethylene / α,β-unsaturated carboxylic acid copolymer; and The montanic acid ester is contained in an amount of 5 to 200 parts by mass per 100 parts by mass of the ethylene / α,β-unsaturated carboxylic acid copolymer. An aqueous composition which is a paper coating.

4. The ethylene / α,β-unsaturated carboxylic acid copolymer is A copolymer containing 8% by mass or more of an α,β-unsaturated carboxylic acid. The composition of claim 3.

5. The composition according to claim 3 or 4, comprising 10 to 200 parts by mass of a montanic acid ester per 100 parts by mass of the ethylene / α,β-unsaturated carboxylic acid copolymer.

6. The composition according to any one of claims 3 to 5, wherein the montanic acid ester is an ester of montanic acid and ethylene glycol.

7. The composition according to any one of claims 1 to 6, wherein the α,β-unsaturated carboxylic acid is (meth)acrylic acid.

8. The copolymer and the ester are dispersed in the dispersion. The composition according to any one of claims 1 to 7.

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