Aqueous coating agent, article, and method for producing polyester resin component

Abstract

This aqueous coating agent contains an aqueous medium and a polyester resin component. The polyester resin component contains a rosin-modified polyester resin, which is the reaction product of raw material components including (A) a rosin, (B) an α,β-unsaturated dicarboxylic acid, and (C) polyols. The acid value of the polyester resin component is 60-180 mgKOH / g. The hydroxyl value of the polyester resin component is 20-180 mgKOH / g.

Description

[Technical Field]

[0001] The present invention relates to an aqueous coating agent, an article, and a method for producing a rosin-modified polyester resin. [Background technology]

[0002] Aqueous coating agents have been known in the art. The aqueous coating agents are applied to a substrate to form a coating film, for example.

[0003] The aqueous coating agent contains a resin obtained, for example, by the following method. First, 185.2 g of fatty acid dimer, 1453.3 g of pine oil rosin, 6 g of phenolsulfonic acid, and 185.2 g of polyglycerol are mixed. The mixture is then heated to 250-270°C and reacted until the acid value reaches 6 mgKOH / g. This results in a resin coating film with excellent water resistance (see, for example, Patent Document 1 (Example 1)). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2013 / 0197152 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, depending on the field of application of the water-based coating agent, there are cases where a coating film having excellent oil resistance rather than water resistance is required.

[0006] The present invention relates to an aqueous coating agent capable of forming a coating film having excellent oil resistance, an article including a coating film obtained using the aqueous coating agent, and a method for producing a rosin-modified polyester resin contained in the aqueous coating agent. [Means for solving the problem]

[0007] The present invention [1] includes an aqueous coating agent comprising an aqueous medium and a polyester resin component, the polyester resin component comprising a rosin-modified polyester resin which is a reaction product of raw material components including (A) rosins, (B) an α,β-unsaturated dicarboxylic acid, and (C) a polyol, the acid value of the polyester resin component being 60 mgKOH / g or more and 180 mgKOH / g or less, and the hydroxyl value of the polyester resin component being 20 mgKOH / g or more and 180 mgKOH / g or less.

[0008] The present invention [2] comprises the aqueous coating agent according to the above [1], wherein the content of the (B) α,β-unsaturated dicarboxylic acid in the raw material components is 70 mol or more and 150 mol or less per 100 mol of the (A) rosin.

[0009] The present invention [3] includes the aqueous coating agent according to the above [1] or [2], in which the (B) α,β-unsaturated dicarboxylic acid includes fumaric acid and / or maleic anhydride.

[0010] The present invention [4] includes the aqueous coating agent according to any one of the above [1] to [3], wherein the raw material components further include (D) fats and / or oils and / or fatty acids.

[0011] The present invention [5] includes the aqueous coating agent according to the above [4], in which the content of the (D) oils and / or fatty acids is 10% by mass or more and 30% by mass or less relative to the total amount of the raw material components.

[0012] The present invention [6] further comprises the aqueous coating agent according to any one of the above [1] to [5], which further contains a styrene-(meth)acrylic copolymer.

[0013] The present invention [7] further comprises the aqueous coating agent according to any one of the above [1] to [6], which further contains a wax.

[0014] The present invention [8] includes an article comprising a coating film of the aqueous coating agent according to any one of the above [1] to [7].

[0015] The present invention [9] includes a method for producing a rosin-modified polyester resin, which comprises a first step of reacting (A) a rosin with (B) an α,β-unsaturated dicarboxylic acid to obtain a first product, and a second step of reacting, after the first step, the first product with (C) a polyol to obtain a second product, wherein the reaction temperature in the second step is 230°C or less.

[0016] The present invention

[10] includes the method for producing a rosin-modified polyester resin according to the above [9], which further comprises a modification step of modifying the (C) polyol with (D) oils and / or fatty acids before the second step, and the reaction temperature in the modification step is 230°C or higher and 300°C or lower. [Effects of the Invention]

[0017] The aqueous coating agent of the present invention has a polyester resin component containing a rosin-modified polyester resin having an acid value within a predetermined range and a hydroxyl value within a predetermined range, thereby enabling the formation of a coating film having excellent oil resistance.

[0018] The article of the present invention has excellent oil resistance because it contains a coating film of the above-mentioned aqueous coating agent.

[0019] According to the method for producing a rosin-modified polyester resin of the present invention, a rosin-modified polyester resin having excellent oil resistance can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0020] The aqueous coating agent of the present invention contains an aqueous medium and a polyester resin component. More specifically, the aqueous coating agent contains an aqueous medium and a polyester resin component dissolved and / or dispersed in the aqueous medium.

[0021] Examples of aqueous media include water and hydrophilic solvents. Examples of hydrophilic solvents include alcohols, ketones, esters, ethers, ether alcohols, ether alcohol acetates, and nitriles. Examples of alcohols include methanol and ethanol. Examples of ketones include acetone. Examples of esters include ethyl acetate and butyl acetate. Examples of ethers include dioxane and tetrahydrofuran. Examples of ether alcohols include cellosolve and carbitol. Examples of ether alcohol acetates include cellosolve acetate and carbitol acetate. Examples of nitriles include acetonitrile. These can be used alone or in combination of two or more. A preferred aqueous medium is water.

[0022] The polyester resin component contains a rosin-modified polyester resin as a main component. The main component is a component contained in a proportion of 75% by mass or more, preferably 80% by mass or more, based on the total amount. The polyester resin component may also contain unreacted raw material components as secondary components, as will be described in detail below.

[0023] The rosin-modified polyester resin is a polyester resin modified with rosins. The rosin-modified polyester resin is a reaction product of raw material components. The raw material components essentially contain (A) rosins, (B) an α,β-unsaturated dicarboxylic acid, and (C) a polyol.

[0024] More specifically, the raw material components may include, for example, (A) rosins, (B) α,β-unsaturated dicarboxylic acid, and (C) polyol, where the total amount of (A) rosins, (B) α,β-unsaturated dicarboxylic acid, and (C) polyol is 100% by mass of the raw material components.

[0025] (A) Rosins are plant-derived components. Therefore, rosin-modified polyester resins can contribute to carbon neutrality. More specifically, (A) Rosins are compounds derived from pine. There are no particular limitations on the type of pine, and examples include Merkus pine, slash pine, and Masson pine. These can be used alone or in combination of two or more types.

[0026] (A) Rosins are not particularly limited and include known unmodified rosins and / or derivatives thereof. Examples of unmodified rosins include crude rosin and refined rosin. Examples of crude rosins include gum rosin, tall rosin, and wood rosin. Examples of refined rosins include refined products of crude rosin. Examples of rosin derivatives include hydrogenated rosin, disproportionated rosin, and polymerized rosin. These can be used alone or in combination of two or more. The origin of rosin is not particularly limited and includes, for example, China, Vietnam, Indonesia, and Brazil. These can be used alone or in combination of two or more.

[0027] As the (A) rosin, from the viewpoint of film-forming ability and water resistance, preferably, unmodified rosin is used, and more preferably, gum rosin is used.

[0028] The content of the (A) rosins relative to the total amount of raw materials is, from the viewpoints of film-forming ability, water resistance, and tack resistance, for example, 20% by mass or more, preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more. Also, from the viewpoints of film-forming ability, water resistance, and tack resistance, the content of the (A) rosins relative to the total amount of raw materials is, from the viewpoints of film-forming ability, water resistance, and tack resistance, for example, 80% by mass or less, preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less, and particularly preferably 40% by mass or less.

[0029] (B) α,β-unsaturated dicarboxylic acid is a component that improves the oil resistance of the coating film. Examples of (B) α,β-unsaturated dicarboxylic acid include fumaric acid, maleic acid, itaconic acid, citraconic acid, and their anhydrides. Examples of anhydrides include maleic anhydride, itaconic anhydride, and citraconic anhydride. These can be used alone or in combination of two or more.

[0030] The (B) α,β-unsaturated dicarboxylic acid is preferably fumaric acid and maleic anhydride, more preferably fumaric acid, i.e., the (B) α,β-unsaturated dicarboxylic acid preferably contains fumaric acid and / or maleic anhydride, more preferably contains fumaric acid.

[0031] The content of the (B) α,β-unsaturated dicarboxylic acid relative to the total amount of the raw material components is, from the viewpoint of oil resistance, for example, 3 mass% or more, preferably 5 mass% or more, more preferably 10 mass% or more, and even more preferably 12 mass% or more. Also, from the viewpoint of oil resistance, the content of the (B) α,β-unsaturated dicarboxylic acid relative to the total amount of the raw material components is, from the viewpoint of oil resistance, for example, 40 mass% or less, preferably 30 mass% or less, more preferably 25 mass% or less, and even more preferably 20 mass% or less.

[0032] The content of the (B) α,β-unsaturated dicarboxylic acid is, from the viewpoint of oil resistance, for example, 50 moles or more, preferably 70 moles or more, more preferably 80 moles or more, and even more preferably 90 moles or more, per 100 moles of the (A) rosin. The content of the (B) α,β-unsaturated dicarboxylic acid is, from the viewpoint of oil resistance, for example, 200 moles or less, preferably 150 moles or less, and more preferably 120 moles or less, per 100 moles of the (A) rosin.

[0033] If the amount of (B) α,β-unsaturated dicarboxylic acid is below the above range, the amount of unreacted (A) rosins will be relatively large, which may result in reduced oil resistance.If the amount of (B) α,β-unsaturated dicarboxylic acid is above the above range, the amount of unreacted (B) α,β-unsaturated dicarboxylic acid will be relatively large, which may result in reduced film-forming ability, which may result in reduced oil resistance.

[0034] (C) Polyols include, for example, dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Dihydric alcohols include linear alkyl diols, branched alkyl diols, and ether diols. Linear alkyl diols include, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Branched alkyl diols include, for example, propylene glycol, 1,3-butanediol, 1,2-butanediol, 3-methyl-1,5-pentanediol, and 2,6-dimethyl-1-octene-3,8-diol. Ether diols include, for example, diethylene glycol, triethylene glycol, and dipropylene glycol.

[0035] Examples of dihydric alcohols include 1,4-dihydroxy-2-butene, isosorbide, cyclohexanedimethanol, cyclohexanediol, tricyclodecanedimethylol, bisphenol A, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone, and dicyclopentadiene diallyl alcohol copolymer. Examples of trihydric alcohols include glycerin, trimethylolethane, trimethylolpropane, trimethylolhexane, and trimethyloloctane. Examples of tetrahydric or higher alcohols include tetrahydric to octahydric alcohols. Examples of tetrahydric to octahydric alcohols include pentaerythritol, diglycerin, ditrimethylolpropane, sorbitan, sorbitol, dipentaerythritol, inositol, and tripentaerythritol. These can be used alone or in combination of two or more.

[0036] As the (C) polyol, from the viewpoint of oil resistance, preferably, trihydric alcohols and tetrahydric or higher alcohols are used, more preferably, trihydric alcohols are used, even more preferably, trimethylolpropane, glycerin, and pentaerythritol are used, and particularly preferably, glycerin is used.

[0037] The number of carbon atoms in the (C) polyol is, for example, 2 or more, preferably 3 or more. The number of carbon atoms in the (C) polyol is, for example, 30 or less, preferably 20 or less, more preferably 10 or less, and still more preferably 8 or less.

[0038] The content of the polyol (C) relative to the total amount of the raw material components is, from the viewpoint of oil resistance, for example, 5% by mass or more, preferably 8% by mass or more, more preferably 12% by mass or more, even more preferably 13% by mass or more, and particularly preferably 15% by mass or more. Also, from the viewpoint of oil resistance, the content of the polyol (C) relative to the total amount of the raw material components is, from the viewpoint of oil resistance, for example, 40% by mass or less, preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less.

[0039] The raw material components may optionally contain (D) fats and / or fatty acids. If the raw material components contain (D) fats and / or fatty acids, the oil resistance of the coating film can be improved.

[0040] More specifically, the raw material components may comprise, for example, (A) rosins, (B) α,β-unsaturated dicarboxylic acid, (C) polyol, and (D) fats and / or oils and / or fatty acids, where the total amount of (A) rosins, (B) α,β-unsaturated dicarboxylic acid, (C) polyol, and (D) fats and / or oils and / or fatty acids is 100% by mass of the raw material components.

[0041] Examples of fats and oils include linseed oil, yuzu oil, pistachio oil, rice oil, safflower oil, apricot oil, cottonseed oil, sesame oil, corn oil, watermelon oil, soybean oil, poppy seed oil, apple oil, sunflower oil, cactus oil, tall oil, walnut oil, tung oil, and castor oil. Fatty acids include fatty acids derived from the above fats and oils. More specifically, fatty acids include linseed oil fatty acids, yuzu oil fatty acids, pistachio oil fatty acids, rice oil fatty acids, safflower oil fatty acids, apricot oil fatty acids, cottonseed oil fatty acids, sesame oil fatty acids, corn oil fatty acids, watermelon oil fatty acids, soybean oil fatty acids, poppy seed oil fatty acids, apple oil fatty acids, sunflower oil fatty acids, cactus oil fatty acids, tall oil fatty acids, walnut oil fatty acids, tung oil fatty acids, and castor oil fatty acids. These can be used alone or in combination of two or more.

[0042] The content of (D) fats and / or fatty acids (when used in combination, their total amount) relative to the total amount of raw material ingredients is, from the viewpoints of flexibility, water resistance, and oil resistance, for example, 0% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, even more preferably 15% by mass or more, and particularly preferably 17% by mass or more. Also, the content of (D) fats and / or fatty acids (when used in combination, their total amount) relative to the total amount of raw material ingredients is, from the viewpoints of flexibility, water resistance, and oil resistance, for example, 40% by mass or less, preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less.

[0043] From the viewpoint of oil resistance, the (D) fats and / or fatty acids are preferably fats and / or fatty acids having a predetermined iodine value. More specifically, from the viewpoint of oil resistance, the (D) fats and / or fatty acids have an iodine value of, for example, 50 mg / 100 mg or more, preferably 70 mg / 100 mg or more, more preferably 100 mg / 100 mg or more.

[0044] More preferably, the (D) oil and / or fatty acid has an iodine value of 100 mg / 100 from the viewpoint of oil resistance. m The (D) oils and / or fatty acids contain, as the main component, an iodine value of 100 or more of fats and / or fatty acids in an amount of 80% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. That is, the content of fats and / or fatty acids having an iodine value of 100 or more relative to the total amount of fats and / or fatty acids is, for example, 80% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. Particularly preferably, the (D) oils and / or fatty acids have an iodine value of 100 mg / 100 m g or more of fats and / or fatty acids.

[0045] Iodine value 100mg / 100 mExamples of fats and / or oils with a saturation of 1000 g or more and / or fatty acids include linseed oil, yuzu oil, pistachio oil, rice oil, safflower oil, apricot oil, cottonseed oil, sesame oil, corn oil, watermelon oil, soybean oil, poppy seed oil, apple oil, sunflower oil, cactus oil, tall oil, walnut oil, tung oil, castor oil, and fatty acids derived from these fats and oils.

[0046] The iodine value is measured according to "2.3.4.1-1996 (Wijs-Cyclohexane Method)" of the Standard Methods for the Analysis of Fats, Oils, and Related Materials (Japan Oil Chemists' Society). Specifically, to measure the iodine value, 0.15 g of the target vegetable oil is first dissolved in 10 ml of cyclohexane. Next, 25 ml of Wijs solution is added to the solution, and the mixture is left in the dark for approximately 1 hour. The solution is then titrated with a 0.1 mol / L sodium thiosulfate standard solution.

[0047] The iodine value is then calculated based on the amount of sodium thiosulfate standard solution added dropwise until the end point is reached.

[0048] The raw material components may also contain (E) other carboxylic acids as optional components. (E) other carboxylic acids are carboxylic acids other than (A) rosins, (B) α,β-unsaturated dicarboxylic acids, and (D) fats and / or oils and / or fatty acids.

[0049] More specifically, the raw material components may include, for example, (A) rosins, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, (D) fats and / or oils and / or fatty acids, and (E) other carboxylic acids. In this case, the total amount of (A) rosins, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, (D) fats and / or oils and / or fatty acids, and (E) other carboxylic acids is 100% by mass of the raw material components.

[0050] The raw material components may include, for example, (A) rosins, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, and (E) other carboxylic acids, where the total amount of (A) rosins, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, and (E) other carboxylic acids is 100% by mass of the raw material components.

[0051] (E) Other carboxylic acids include, for example, α,β-unsaturated monocarboxylic acids and carboxylic acids that do not have an unsaturated bond between the α-carbon and the β-carbon.

[0052] Examples of the α,β-unsaturated monocarboxylic acid include acrylic acid and methacrylic acid, which can be used alone or in combination of two or more.

[0053] From the viewpoint of oil resistance, the content of the α,β-unsaturated monocarboxylic acid relative to the total amount of the raw material components is, for example, 0% by mass or more, preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more. Also, from the viewpoint of oil resistance, the content of the α,β-unsaturated monocarboxylic acid relative to the total amount of the raw material components is, for example, 40% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0054] Examples of carboxylic acids that do not have an unsaturated bond between the α- and β-carbons include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, oxaloacetic acid, methylmalonic acid, dimethylmalonic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, methylglutaric acid, dimethylglutaric acid, diglycolic acid, 1, Examples of suitable carboxylic acids include 3-acetonedicarboxylic acid, ketoglutaric acid, cyclopropane-1,1-dicarboxylic acid, cyclobutane-1,1-dicarboxylic acid, cyclohexane-1,1-dicarboxylic acid, 2-oxoadipic acid, 4-oxoheptanedioic acid, 5-oxoazelaic acid, phenylenedioxydiacetic acid, indan-2,2-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexanedicarboxylic acid, trimellitic acid, and pyromellitic acid. These may be used alone or in combination of two or more.

[0055] Preferred examples of the carboxylic acid having no unsaturated bond between the α- and β-carbons include succinic acid and adipic acid. The carboxylic acid having no unsaturated bond between the α- and β-carbons can improve oil resistance.

[0056] From the viewpoint of oil resistance, the content of the carboxylic acid having no unsaturated bond between the α- and β-carbons relative to the total amount of the raw material components is, for example, 0% by mass or more, preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 10% by mass or more. Also, from the viewpoint of oil resistance, the content of the carboxylic acid having no unsaturated bond between the α- and β-carbons relative to the total amount of the raw material components is, for example, 30% by mass or less, preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0057] Furthermore, as the (E) other carboxylic acid, the above-mentioned α,β-unsaturated monocarboxylic acid may be used in combination with a carboxylic acid having no unsaturated bond between the α- and β-carbons. In such a case, the total amount of the α,β-unsaturated monocarboxylic acid and the carboxylic acid having no unsaturated bond between the α- and β-carbons is, for example, 0% by mass or more, preferably 5% by mass or more, based on the total amount of the raw material components. Furthermore, the total amount of the α,β-unsaturated monocarboxylic acid and the carboxylic acid having no unsaturated bond between the α- and β-carbons is, for example, 60% by mass or less, preferably 40% by mass or less, based on the total amount of the raw material components.

[0058] The rosin-modified polyester resin can be obtained as a reaction product by reacting the above-mentioned raw material components. In this reaction, for example, the above-mentioned raw material components may be reacted all at once, or the raw material components may be reacted in multiple stages. Preferably, the above-mentioned raw material components are reacted in multiple stages.

[0059] In the multi-stage reaction, the order of the reactions is not particularly limited. Preferably, first, (A) a rosin and (B) an α,β-unsaturated dicarboxylic acid are reacted to obtain a first product. Then, (C) the first product is reacted with a polyol to obtain a second product containing a rosin-modified polyester resin.

[0060] More specifically, in this method, (A) rosin and (B) α,β-unsaturated dicarboxylic acid are first mixed in the above-mentioned ratio, and then (A) rosin and (B) α,β-unsaturated dicarboxylic acid are reacted with each other to obtain a first product (first step).

[0061] More specifically, in the first step, (A) the conjugated double bonds in the rosin undergo a Diels-Alder reaction with (B) the double bonds in the α,β-unsaturated dicarboxylic acid.

[0062] The reaction temperature in the first step is, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, for example, 150° C. or higher, preferably 170° C. or higher, and more preferably 180° C. or higher. Also, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction temperature in the first step is, for example, 230° C. or lower, preferably 220° C. or lower, and more preferably 200° C. or lower.

[0063] The reaction time in the first step is, for example, 0.1 hours or more, preferably 0.5 hours or more, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, and is, for example, 5 hours or less, preferably 3 hours or less, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin.

[0064] In the first step, a known reaction catalyst can be added in an appropriate ratio as needed. In the first step, the raw material components may be reacted in the absence of a solvent, or in the presence of a known solvent.

[0065] This results in a first product containing (A) a tertiary carboxy group derived from the rosin (the tertiary carboxy group of the abietic acid monomer) and (B) a secondary carboxy group derived from the α,β-unsaturated dicarboxylic acid.

[0066] Next, in this method, the polyol (C) is blended with the first product in the above ratio, and the first product and the polyol (C) are reacted to obtain a second product (second step).

[0067] More specifically, in the second step, the carboxyl group contained in the first product and the hydroxyl group contained in the (C) polyol are subjected to an esterification reaction.

[0068] The reaction temperature in the second step is, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, for example, 150° C. or higher, preferably 160° C. or higher, more preferably 170° C. or higher, and even more preferably 180° C. or higher. Also, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction temperature in the second step is, for example, 230° C. or lower, preferably 220° C. or lower, more preferably 210° C. or lower, and even more preferably 200° C. or lower.

[0069] If the reaction temperature is within the above range, the reaction of the tertiary carboxyl groups derived from (A) rosins can be suppressed, and the secondary carboxyl groups derived from (B) α,β-unsaturated dicarboxylic acids can be reacted, thereby improving film-forming properties and oil resistance.

[0070] More specifically, if the reaction temperature exceeds the upper limit, the tertiary carboxyl groups derived from the rosin (A) react with the hydroxyl groups contained in the polyol (C), making it easier for the polyester resin component to form a network structure. Therefore, when the rosin-modified polyester resin is used in an aqueous coating agent, the oil resistance may be reduced. Furthermore, if the reaction temperature is below the lower limit, the reaction may not proceed sufficiently, resulting in reduced oil resistance.

[0071] The reaction time in the second step is, for example, 1 hour or more, preferably 3 hours or more, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin. The reaction time in the second step is, for example, 48 hours or less, preferably 24 hours or less, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin. In this reaction, condensation water generated by the esterification reaction can be removed by distillation, if necessary, using a known method.

[0072] In the second step, if necessary, the first product and the polyol (C) may be added with the fats and / or oils (D) and / or fatty acids in the above-mentioned ratio, and the mixture may be reacted. More specifically, the carboxyl groups contained in the fats and / or oils (D) and / or fatty acids may be esterified with the hydroxyl groups contained in the polyol (C).

[0073] In the second step, if necessary, the other carboxylic acid (E) can be added to the first product and the polyol (C) in the above-mentioned ratio and reacted. More specifically, the carboxyl group contained in the other carboxylic acid (E) can be esterified with the hydroxyl group contained in the polyol (C).

[0074] In the second step, a known reaction catalyst can be added in an appropriate ratio, if necessary. In the second step, the raw material components may be reacted in the absence of a solvent, or in the presence of a known solvent.

[0075] This results in a second product. The second product is a resin composition containing the rosin-modified polyester resin. The second product (resin composition) can be used as a polyester resin component of an aqueous coating agent.

[0076] Furthermore, when the raw material components contain (D) fats and / or fatty acids, (C) polyol can be modified with (D) fats and / or fatty acids (modification step) before the second step.

[0077] The blending ratio in the modification step is set appropriately, but for example, the amount of hydroxyl groups in the (C) polyol per 1 mole of the (D) fats and / or oils and / or fatty acids is, for example, 3 moles or more, preferably 10 moles or more, and for example, 50 moles or less, preferably 40 moles or less.

[0078] From the viewpoint of oil resistance and film-forming ability, the reaction temperature in the modification step is, for example, 230°C or higher, preferably 240°C or higher, and more preferably 250°C or higher. From the viewpoint of oil resistance and film-forming ability, the reaction temperature in the modification step is, for example, 300°C or lower, preferably 280°C or lower, and more preferably 270°C or lower. If the reaction temperature is too low, the reaction in the modification step may not proceed, and (D) oils and / or fatty acids may not be incorporated into the resin. This may result in a decrease in oil resistance and film-forming ability. If the reaction temperature is too high, a decomposition reaction may occur, causing an increase in low-molecular-weight components. This may result in a decrease in oil resistance and film-forming ability.

[0079] The reaction time in the modification step is, from the viewpoints of oil resistance and film-forming ability, for example, 0.5 hours or more, preferably 1 hour or more, and from the viewpoints of oil resistance and film-forming ability, for example, 20 hours or less, preferably 10 hours or less.

[0080] In the modification step, a known reaction catalyst can be added in an appropriate ratio, if necessary. In the modification step, the raw material components may be reacted in the absence of a solvent, or in the presence of a known solvent.

[0081] According to the above method, a (C) polyol modified with a (D) fat or oil and / or a fatty acid is obtained. The (C) polyol modified with a (D) fat or oil and / or a fatty acid is then used in the second step. That is, the first product and the (C) polyol modified with a (D) fat or oil and / or a fatty acid are subjected to an esterification reaction.

[0082] This results in a second product. The second product is a resin composition containing the rosin-modified polyester resin. The second product (resin composition) can be used as a polyester resin component of an aqueous coating agent.

[0083] The weight-average molecular weight (standard polystyrene equivalent) of the rosin-modified polyester resin is, for example, 1,000 or more, preferably 3,000 or more, more preferably 5,000 or more, and the weight-average molecular weight (standard polystyrene equivalent) of the rosin-modified polyester resin is, for example, 100,000 or less, preferably 70,000 or less, more preferably 50,000 or less.

[0084] The softening point of the rosin-modified polyester resin (measured by the Mettler method) is, from the viewpoints of film-forming ability and tack resistance, for example, 70° C. or higher, preferably 75° C. or higher, and more preferably 80° C. or higher. The softening point of the rosin-modified polyester resin (measured by the Mettler method) is, from the viewpoints of film-forming ability and tack resistance, for example, 150° C. or lower, preferably 130° C. or lower, and more preferably 120° C. or lower.

[0085] The content of the rosin-modified polyester resin relative to the total amount of the polyester resin components is, for example, 75% by mass or more, or preferably 80% by mass or more, and for example, 100% by mass or less, or preferably 90% by mass or less, relative to the total amount of the polyester resin components.

[0086] The polyester resin component may contain unreacted raw material components in addition to the rosin-modified polyester resin. Examples of the unreacted raw material components include (A) unreacted rosins, (B) unreacted α,β-unsaturated dicarboxylic acids, (C) unreacted polyols, (D) unreacted fats and / or oils and / or fatty acids, and (E) unreacted other carboxylic acids. The unreacted raw material components are removed from the resin composition as necessary.

[0087] The molecular weight of the unreacted raw material components is usually 500 or less. Hereinafter, the unreacted raw material components will be referred to as components having a molecular weight of 500 or less. The content ratio of the components having a molecular weight of 500 or less relative to the total amount of the resin composition (polyester resin component) is, for example, 25% by mass or less, or preferably 20% by mass or less. The content ratio of the components having a molecular weight of 500 or less relative to the total amount of the resin composition (polyester resin component) is, for example, 0% by mass or more, or preferably 10% by mass or more.

[0088] If the component having a molecular weight of 500 or less is contained in an excessive amount relative to the polyester resin component, film-forming ability and oil resistance may be reduced. The content ratio of the component having a molecular weight of 500 or less is measured by gel permeation chromatography in accordance with the examples described later.

[0089] From the viewpoint of oil resistance, the acid value of the polyester resin component is 60 mgKOH / g or more, preferably 80 mgKOH / g or more, more preferably 100 mgKOH / g or more, and even more preferably 120 mgKOH / g or more. From the viewpoint of oil resistance, the acid value of the polyester resin component is 180 mgKOH / g or less, preferably 170 mgKOH / g or less, more preferably 160 mgKOH / g or less, even more preferably 150 mgKOH / g or less, and particularly preferably 130 mgKOH / g or less. The acid value of the polyester resin component is measured in accordance with JIS K 5601-2-1 (1999).

[0090] From the viewpoint of oil resistance, the hydroxyl value of the polyester resin component is 20 mgKOH / g or more, preferably 40 mgKOH / g or more, more preferably 60 mgKOH / g or more, even more preferably 80 mgKOH / g or more, even more preferably 120 mgKOH / g or more, and particularly preferably 130 mgKOH / g or more. From the viewpoint of oil resistance, the hydroxyl value of the polyester resin component is 180 mgKOH / g or less, preferably 170 mgKOH / g or less, more preferably 160 mgKOH / g or less, even more preferably 150 mgKOH / g or less, and particularly preferably 140 mgKOH / g or less. The hydroxyl value is measured in accordance with JIS K 0070 (1992).

[0091] In order to adjust the acid value and hydroxyl value of the polyester resin component to fall within the above ranges, for example, the blending amounts of the raw material components are adjusted to the above ratios, and the reaction temperature and reaction time are adjusted to the above conditions.

[0092] The polyester resin component is then dissolved and / or dispersed in an aqueous medium to obtain an aqueous coating agent.

[0093] The ratio of the aqueous medium to the polyester resin component is appropriately set depending on the purpose and application. For example, the aqueous medium is, for example, 5% by mass or more, preferably 10% by mass or more, based on the total amount of the aqueous medium and the polyester resin component. Furthermore, the aqueous medium is, for example, 80% by mass or less, preferably 70% by mass or less, based on the total amount of the aqueous medium and the polyester resin component. Furthermore, the polyester resin component is, for example, 20% by mass or more, preferably 30% by mass or more, based on the total amount of the aqueous medium and the polyester resin component. Furthermore, the polyester resin component is, for example, 95% by mass or less, preferably 90% by mass or less, based on the total amount of the aqueous medium and the polyester resin component. When the ratio of the aqueous medium to the polyester resin component is within the above range, a sudden increase in viscosity can be suppressed, and the productivity, coatability, and drying properties of the aqueous coating agent can be improved.

[0094] The aqueous coating agent may contain other resins in addition to the aqueous medium and the polyester resin component. The other resins are resins other than the polyester resin component.

[0095] Examples of other resins include acrylic resins, styrene-modified acrylic resins, silicone acrylic resins, modified silicone acrylic resins, rosin phenolic resins, rosin ester resins, terpene phenolic resins, coumarone-indene resins, petroleum resins, epoxy resins, modified epoxy resins, polyester resins, vinyl acetate resins, ethylene-vinyl acetate resins, urethane resins, urea resins, melamine resins, and cellulose resins. These can be used alone or in combination of two or more.

[0096] As the other resin, a styrene-modified acrylic resin is preferably used. When the aqueous coating agent contains a styrene-modified acrylic resin, better oil resistance can be obtained.

[0097] More specifically, the styrene-modified acrylic resin may be a styrene-(meth)acrylic copolymer. From the viewpoint of oil resistance, the aqueous coating agent preferably contains a styrene-(meth)acrylic copolymer. Here, (meth)acrylic refers to acrylic and / or methacrylic.

[0098] The styrene-(meth)acrylic copolymer can be obtained, for example, by copolymerizing a monomer component containing a styrene and a (meth)acrylic monomer copolymerizable with the styrene.

[0099] Examples of styrenes include styrene, α-methylstyrene, vinyltoluene, ethylvinyltoluene, and chloromethylstyrene. These can be used alone or in combination of two or more. A preferred example of the styrenes is styrene.

[0100] The content of styrenes relative to the total amount of the monomer components is, for example, 10% by mass or more, preferably 20% by mass or more. The content of styrenes relative to the total amount of the monomer components is, for example, 80% by mass or less, preferably 70% by mass or less. When the content of styrenes is within the above range, particularly excellent oil resistance can be obtained.

[0101] Examples of the (meth)acrylic monomer include (meth)acrylic acid esters and hydrophilic group-containing (meth)acrylic monomers.

[0102] Examples of (meth)acrylic acid esters include (meth)acrylic acid esters having an alkyl group having 1 to 24 carbon atoms. The alkyl group may be linear or branched, and may have a carbon ring (alicyclic and / or aromatic ring). Specific examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, i-decyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, cyclohexyl (meth)acrylate, and benzyl (meth)acrylate. These may be used alone or in combination of two or more.

[0103] As the (meth)acrylic acid ester, preferred examples include methyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and more preferred examples include methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate. Furthermore, as the (meth)acrylic acid ester, a more preferred example is a combination of methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate. Furthermore, as the (meth)acrylic acid ester, a more preferred example is a combination of methyl methacrylate and butyl acrylate.

[0104] Examples of hydrophilic group-containing (meth)acrylic monomers include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, and heterocycle-containing monomers.

[0105] Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, N-hydroxyethyl acrylamide, methylol (meth)acrylamide, polyalkylene glycol (meth)acrylate, and glycerol mono(meth)acrylate. These can be used alone or in combination of two or more. A preferred hydroxyl group-containing monomer is 2-hydroxyethyl methacrylate.

[0106] Examples of carboxyl-containing monomers include monocarboxylic acid-containing monomers, dicarboxylic acid-containing monomers, and acid anhydrides. Examples of monocarboxylic acid-containing monomers include (meth)acrylic acid and crotonic acid. Examples of dicarboxylic acid-containing monomers include maleic acid, fumaric acid, itaconic acid, and citraconic acid. Examples of acid anhydrides include acid anhydrides of monocarboxylic acid-containing monomers and dicarboxylic acid-containing monomers. These can be used alone or in combination of two or more. Preferably, the carboxyl-containing monomer is a monocarboxylic acid-containing monomer, and more preferably, methacrylic acid.

[0107] Examples of amino group-containing monomers include 2-(dimethylamino)ethyl (meth)acrylate and dimethylaminopropyl (meth)acrylamide, which can be used alone or in combination of two or more.

[0108] Examples of amide group-containing monomers include acrylamide, methacrylamide, N-isopropylacrylamide, N-vinylformamide, N-vinylacetamide, and N,N'-dimethylacrylamide. These can be used alone or in combination of two or more.

[0109] Examples of heterocycle-containing monomers include N-vinylpyrrolidone, which can be used alone or in combination of two or more.

[0110] The hydrophilic group-containing (meth)acrylic monomers can be used alone or in combination of two or more. Preferred examples of the hydrophilic group-containing (meth)acrylic monomers include hydroxyl group-containing monomers and carboxyl group-containing monomers.

[0111] The (meth)acrylic monomers can be used alone or in combination of two or more. As the (meth)acrylic monomers, preferred are (meth)acrylic acid esters and hydrophilic group-containing (meth)acrylic monomers, and more preferred are the combined use of (meth)acrylic acid esters and hydrophilic group-containing (meth)acrylic monomers.

[0112] That is, the monomer component preferably contains a styrene, a (meth)acrylic acid alkyl ester, and a hydrophilic group-containing (meth)acrylic monomer.

[0113] The monomer component more preferably contains a styrene, a (meth)acrylic acid alkyl ester, a hydroxyl group-containing monomer and / or a carboxyl group-containing monomer.

[0114] The monomer component more preferably comprises a styrene, a (meth)acrylic acid alkyl ester, a hydroxyl group-containing monomer and / or a carboxyl group-containing monomer.

[0115] The content of the (meth)acrylic monomer is appropriately set depending on the purpose and application.

[0116] For example, when the (meth)acrylic monomer contains a (meth)acrylic acid alkyl ester, the content (total amount) of the (meth)acrylic acid alkyl ester is, for example, 10% by mass or more, preferably 20% by mass or more, based on the total amount of the monomer components. Also, the content (total amount) of the (meth)acrylic acid alkyl ester is, for example, 90% by mass or less, preferably 80% by mass or less, based on the total amount of the monomer components.

[0117] When the (meth)acrylic monomer contains a hydroxyl group-containing monomer, the content (total amount) of the hydroxyl group-containing monomer is, for example, 5% by mass or more, preferably 10% by mass or more, based on the total amount of the monomer components, and the content (total amount) of the hydroxyl group-containing monomer is, for example, 60% by mass or less, preferably 50% by mass or less, based on the total amount of the monomer components.

[0118] When the (meth)acrylic monomer contains a carboxyl group-containing monomer, the content (total amount) of the hydroxyl group-containing monomer is, for example, 1% by mass or more, preferably 3% by mass or more, based on the total amount of the monomer components. The content (total amount) of the carboxyl group-containing monomer is, for example, 20% by mass or less, preferably 10% by mass or less, based on the total amount of the monomer components.

[0119] The content (total amount) of the (meth)acrylic monomers is, for example, 20% by mass or more, preferably 30% by mass or more, relative to the total amount of the monomer components, and the content (total amount) of the (meth)acrylic monomers is, for example, 90% by mass or less, preferably 90% by mass or less, more preferably 80% by mass or less, relative to the total amount of the monomer components.

[0120] The styrene-(meth)acrylic copolymer can be obtained, for example, by polymerizing the above-mentioned monomer components by a known method. More specifically, for example, the above-mentioned monomer components are first mixed to prepare a monomer composition. Then, the monomer composition is emulsion-polymerized in the presence of a known aqueous solvent. Examples of the aqueous solvent include the above-mentioned aqueous medium. In the polymerization, the method of adding the monomer composition is not particularly limited, and examples include batch charging, divided charging, total dropwise addition, and partial dropwise addition.

[0121] In addition, a chain transfer agent can be blended in the above polymerization, if necessary. The weight-average molecular weight of the styrene-(meth)acrylic copolymer can be adjusted by the chain transfer agent. Examples of chain transfer agents include oil-soluble chain transfer agents and water-soluble chain transfer agents. Examples of oil-soluble chain transfer agents include t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, mercaptopropionic acid dodecyl ester, cumene, carbon tetrachloride, α-methylstyrene dimer, and terpinolene. Examples of water-soluble chain transfer agents include mercaptoethanol, thioglycolic acid, (meth)allylsulfonic acid, and salts thereof. These can be used alone or in combination of two or more. The type and amount of chain transfer agent are appropriately determined depending on the purpose and application.

[0122] In addition, a polymerization initiator can be blended in the above polymerization, if necessary. Examples of polymerization initiators include azo-based initiators and peroxide-based polymerization initiators. Examples of azo-based initiators include azobismethylbutyronitrile, dimethylazobisisobutyrate, azobisdimethylvaleronitrile, azobisisobutyronitrile, and azobis-2-amidinopropane hydrochloride. Examples of peroxide-based polymerization initiators include persulfates, hydrogen peroxide, benzoyl peroxide, t-butyl peroxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexanoate, and cumene hydroperoxide. Redox initiators can also be used as polymerization initiators. These can be used alone or in combination of two or more types. The type and amount of polymerization initiator are appropriately determined depending on the purpose and application.

[0123] In the polymerization, an emulsifier may be added as needed. Examples of the emulsifier include low-molecular-weight emulsifiers and high-molecular-weight emulsifiers.

[0124] Examples of low-molecular-weight emulsifiers include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, ammonium polyoxyethylene alkylphenyl ether sulfate, sodium polyoxyethylene alkylsulfosuccinate, polyoxyalkylene polycyclic phenyl ether sulfates (e.g., sodium polyoxyethylene polycyclic phenyl ether sulfate, ammonium polyoxyethylene polycyclic phenyl ether sulfate, sodium polyoxypropylene polycyclic phenyl ether sulfate, ammonium polyoxypropylene polycyclic phenyl ether sulfate, etc.), polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and polyoxyethylene fatty acid esters. Examples of polymeric emulsifiers include polyvinyl alcohol and polyethylene oxide. These can be used alone or in combination.

[0125] Further examples of emulsifiers include reactive emulsifiers. Examples of reactive emulsifiers include sulfate salts of polyoxyalkylene phenyl ethers having one or more functional groups containing an ethylenically unsaturated bond, sulfosuccinate salts of polyoxyethylene alkyl ethers having one or more functional groups containing an ethylenically unsaturated bond, sulfate salts of polyoxyethylene alkyl ethers having one or more functional groups containing an ethylenically unsaturated bond, sulfosuccinate salts of polyoxyethylene alkyl phenyl ethers having one or more functional groups containing an ethylenically unsaturated bond, sulfate salts of polyoxyalkylene ethers having one or more functional groups containing an ethylenically unsaturated bond, sulfate salts of polyoxyalkylene alkyl phenyl ethers having one or more functional groups containing an ethylenically unsaturated bond, and acidic phosphate (meth)acrylic acid ester salts having one or more functional groups containing an ethylenically unsaturated bond. Examples of ester salts include sodium ester salts and ammonium ester salts. These can be used alone or in combination.

[0126] The type, amount and timing of addition of the emulsifier are appropriately determined depending on the purpose and application.

[0127] The polymerization conditions are not particularly limited and are appropriately set depending on the type of monomer component, the type of polymerization initiator, and their amounts. For example, the polymerization temperature is, for example, 80°C or higher, preferably 85°C or higher. The polymerization temperature is, for example, 120°C or lower, preferably 115°C or lower. The polymerization time is, for example, 2 hours or longer, preferably 3 hours or longer. The polymerization time is, for example, 6 hours or shorter, preferably 5 hours or shorter.

[0128] By the above polymerization, a solution and / or dispersion of a styrene-(meth)acrylic copolymer is obtained.

[0129] In the solution and / or dispersion of the styrene-(meth)acrylic copolymer, the solid content concentration of the styrene-(meth)acrylic copolymer is, for example, 5% by mass or more, preferably 10% by mass or more, and, for example, 50% by mass or less, preferably 40% by mass or less.

[0130] The viscosity (25°C) of the solution and / or dispersion of the styrene-(meth)acrylic copolymer is, for example, 1 mPa·s or more, preferably 5 mPa·s or more. The viscosity (25°C) of the solution and / or dispersion of the styrene-(meth)acrylic copolymer is, for example, 500 mPa·s or less, preferably 200 mPa·s or less, more preferably 100 mPa·s or less. The viscosity is measured using a B-type viscometer in accordance with JIS K 7117-1 (1999).

[0131] Furthermore, a neutralizing agent is added to the solution and / or dispersion of the styrene-(meth)acrylic copolymer, if necessary. This results in an alkali salt solution of the styrene-(meth)acrylic copolymer. Examples of the neutralizing agent include ammonia.

[0132] The pH of the solution and / or dispersion of the styrene-(meth)acrylic copolymer is, for example, 3 or more, preferably 4 or more. The pH of the solution and / or dispersion of the styrene-(meth)acrylic copolymer is, for example, 10 or less, preferably 9 or less.

[0133] The glass transition temperature of the styrene-(meth)acrylic copolymer is, for example, −30° C. or higher, preferably −10° C. or higher. The glass transition temperature of the styrene-(meth)acrylic copolymer is, for example, 120° C. or lower, preferably 100° C. or lower. The glass transition temperature is calculated by the FOX formula.

[0134] The weight-average molecular weight of the styrene-(meth)acrylic copolymer is, for example, 5,000 or more, preferably 10,000 or more. The weight-average molecular weight of the styrene-(meth)acrylic copolymer is, for example, 300,000 or less, preferably 200,000 or less. The weight-average molecular weight is measured by gel permeation chromatography as a molecular weight converted into standard polystyrene.

[0135] In the aqueous coating agent, the content ratio of the other resin is appropriately set depending on the purpose and application. For example, the content of the other resin (preferably, styrene-(meth)acrylic copolymer) relative to 100 parts by mass of the polyester resin component is, for example, 0 parts by mass or more, preferably 30 parts by mass or more, more preferably 50 parts by mass or more. Furthermore, the content of the other resin (preferably, styrene-(meth)acrylic copolymer) relative to 100 parts by mass of the polyester resin component is, for example, 1000 parts by mass or less, preferably 500 parts by mass or less.

[0136] The aqueous coating agent may contain a wax, and preferably contains a wax.

[0137] Examples of waxes include fatty acid amide wax, carnauba wax, rice wax, polyolefin wax, paraffin wax, Fischer-Tropsch wax, beeswax, microcrystalline wax, oxidized polyethylene wax, and amide wax. These may be used alone or in combination of two or more types.

[0138] As the wax, preferably, fatty acid amide wax, carnauba wax, polyolefin wax, paraffin wax and microcrystalline wax are used, and more preferably, carnauba wax, polyolefin wax and paraffin wax are used.

[0139] More specifically, examples of fatty acid amide waxes include pelargonic acid amide, capric acid amide, undecylic acid amide, lauric acid amide, tridecylic acid amide, myristic acid amide, pentadecylic acid amide, palmitic acid amide, heptadecylic acid amide, stearic acid amide, nonadecanoic acid amide, arachidic acid amide, behenic acid amide, lignoceric acid amide, oleic acid amide, cetoleic acid amide, linoleic acid amide, linolenic acid amide, and mixtures thereof.Further examples of fatty acid amide waxes include animal and vegetable oil fatty acid amides.These can be used alone or in combination of two or more.

[0140] More specific examples of carnauba wax include MICROKLEAR 418 (manufactured by Micro Powders, Inc.) and refined carnauba wax No. 1 powder (manufactured by Nippon Wax Co., Ltd.), which can be used alone or in combination of two or more types.

[0141] More specifically, examples of olefin waxes include polyethylene wax, polypropylene wax, MPP-635VF (Micro Powders, Inc.), and MP-620VF XF (Micro Powders, Inc.), which can be used alone or in combination of two or more.

[0142] More specific examples of paraffin wax include MP-28C, MP-22XF, and MP-28C (all manufactured by Micro Powders, Inc.). These may be used alone or in combination of two or more types.

[0143] The melting point of the wax is, for example, 60°C or higher and, for example, 130°C or lower, from the viewpoint of oil resistance and heat resistance.

[0144] In the aqueous coating agent, the wax content is appropriately set depending on the purpose and use.For example, with respect to 100 parts by mass of the polyester resin component, the wax content is, for example, 0 parts by mass or more, preferably 1 part by mass or more, more preferably 3 parts by mass or more.Furthermore, with respect to 100 parts by mass of the polyester resin component, the wax content is, for example, 50 parts by mass or less, preferably 30 parts by mass or less.

[0145] From the viewpoint of oil resistance, the aqueous coating agent preferably contains a polyester resin component, other resin (preferably a styrene-(meth)acrylic copolymer), and / or wax.

[0146] From the viewpoint of oil resistance, the aqueous coating agent more preferably contains a polyester resin component, another resin (preferably a styrene-(meth)acrylic copolymer), and a wax.

[0147] For example, when the aqueous coating agent contains a polyester resin component and a styrene-(meth)acrylic copolymer but does not contain wax, the polyester resin component is, for example, 10% by mass or more, preferably 20% by mass or more, based on the total amount of the polyester resin component and the styrene-(meth)acrylic copolymer. Furthermore, the polyester resin component is, for example, 80% by mass or less, preferably 50% by mass or less, based on the total amount of the polyester resin component and the styrene-(meth)acrylic copolymer. Furthermore, the styrene-(meth)acrylic copolymer is, for example, 20% by mass or more, preferably 50% by mass or more, based on the total amount of the polyester resin component and the styrene-(meth)acrylic copolymer. Furthermore, the styrene-(meth)acrylic copolymer is, for example, 90% by mass or less, preferably 80% by mass or less, based on the total amount of the polyester resin component and the styrene-(meth)acrylic copolymer.

[0148] Furthermore, when the aqueous coating agent contains a polyester resin component and a wax but does not contain a styrene-(meth)acrylic copolymer, the polyester resin component accounts for, for example, 10% by mass or more, preferably 20% by mass or more, based on the total amount of the polyester resin component and the wax. Furthermore, the polyester resin component accounts for, for example, 80% by mass or less, preferably 50% by mass or less, based on the total amount of the polyester resin component and the wax. Furthermore, the wax accounts for, for example, 20% by mass or more, preferably 50% by mass or more, based on the total amount of the polyester resin component and the wax. Furthermore, the wax accounts for, for example, 90% by mass or less, preferably 80% by mass or less, based on the total amount of the polyester resin component and the wax.

[0149] Furthermore, when the aqueous coating agent contains a polyester resin component, a styrene-(meth)acrylic copolymer, and a wax, the polyester resin component accounts for, for example, 10% by mass or more, preferably 20% by mass or more, relative to the total amount of the polyester resin component, the styrene-(meth)acrylic copolymer, and the wax. Furthermore, the polyester resin component accounts for, for example, 90% by mass or less, preferably 80% by mass or less, relative to the total amount of the polyester resin component, the styrene-(meth)acrylic copolymer, and the wax. Furthermore, the styrene-(meth)acrylic copolymer accounts for, for example, 10% by mass or more, preferably 20% by mass or more, relative to the total amount of the polyester resin component, the styrene-(meth)acrylic copolymer, and the wax. Furthermore, the styrene-(meth)acrylic copolymer accounts for, for example, 90% by mass or less, preferably 80% by mass or less, relative to the total amount of the polyester resin component, the styrene-(meth)acrylic copolymer, and the wax. Furthermore, the wax accounts for, for example, 1% by mass or more, preferably 5% by mass or more, relative to the total amount of the polyester resin component, the styrene-(meth)acrylic copolymer, and the wax. The amount of the wax relative to the total amount of the polyester resin component, the styrene-(meth)acrylic copolymer, and the wax is, for example, 20 mass % or less, or preferably 10 mass % or less.

[0150] The aqueous coating agent may also contain a dispersant. The dispersant is an additive for stably dispersing the rosin-modified polyester resin in the aqueous medium. Examples of dispersants include anionic surfactants, nonionic surfactants, cationic surfactants, polycarboxylic acid dispersants, naphthalene condensation dispersants, aliphatic alcohol sulfate dispersants, polyester dispersants, polyether dispersants, vinyl polymer dispersants, acetylene diol dispersants, and polyaminoamide dispersants. These may be used alone or in combination of two or more. The amount of dispersant to be added is not particularly limited and may be appropriately determined depending on the purpose and application.

[0151] The aqueous coating agent may also contain a neutralizing agent. That is, the carboxyl groups of the polyester resin component may be neutralized with the neutralizing agent. Neutralization can improve the stability of the rosin-modified polyester resin in an aqueous medium.

[0152] Examples of the neutralizing agent include basic compounds. Examples of basic compounds include ammonia, triethylamine, N,N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, pyrrole, and pyridine. These can be used alone or in combination of two or more.

[0153] The amount of neutralizing agent to be added is not particularly limited and is appropriately determined depending on the purpose and application. More specifically, from the viewpoint of the stability of the aqueous coating agent, the amount of neutralizing agent to be added is, for example, 0.5 equivalents or more, preferably 0.8 equivalents or more, relative to the carboxyl groups in the rosin-modified polyester resin. Furthermore, from the viewpoint of the stability of the aqueous coating agent, the amount of neutralizing agent to be added is, for example, 30 equivalents or less, preferably 10 equivalents or less, relative to the carboxyl groups in the rosin-modified polyester resin.

[0154] The aqueous coating agent may further contain additives in an appropriate proportion. Examples of additives include fillers, thickeners, foaming agents, antioxidants, light stabilizers, heat stabilizers, and flame retardants. These may be used alone or in combination of two or more.

[0155] The aqueous coating agent has a polyester resin component containing a rosin-modified polyester resin having an acid value within a predetermined range and a hydroxyl value within a predetermined range, so that the aqueous coating agent can form a coating film having excellent oil resistance.

[0156] More specifically, in order to improve oil resistance, the polyester resin component has a relatively high acid value. However, if a relatively large amount of α,β-unsaturated dicarboxylic acid is simply used to obtain the polyester resin component through a general esterification reaction in order to increase the acid value, gelation is likely to occur during the esterification reaction.

[0157] In contrast, in the above-mentioned method, the temperature conditions in the esterification reaction are adjusted to be relatively low. Therefore, gelation in the esterification reaction is suppressed. In particular, by adjusting the reaction temperature in the esterification reaction to the above-mentioned upper limit or less, the reaction of the tertiary carboxy groups derived from (A) rosins is suppressed, and the carboxy groups derived from (B) α,β-unsaturated dicarboxylic acids can be reacted. Therefore, according to the above-mentioned method, a polyester resin component with a relatively high acid value can be obtained while suppressing gelation. Therefore, an aqueous coating agent containing the above-mentioned polyester resin component can form a coating film with excellent oil resistance.

[0158] The present invention includes an article including a coating of an aqueous coating agent. More specifically, the article includes a substrate and a dried coating of the aqueous coating agent formed on the substrate.

[0159] Examples of the substrate include plastic films, vapor-deposited films, metal foils, paper, woven fabrics, and nonwoven fabrics, and preferably plastic films and paper.

[0160] The aqueous coating agent is applied to a substrate by a known method, such as spraying, curtain coating, flow coating, roll coating, brush coating, dipping, and flexographic printing.

[0161] The aqueous coating agent is then dried by a known method. The drying conditions may be natural drying at room temperature or heated drying. Heat drying is preferred. The drying temperature in heated drying is, for example, 40°C or higher, preferably 50°C or higher. The drying temperature is, for example, 250°C or lower, preferably 230°C or lower. The drying time is, for example, 1 second or longer, preferably 5 seconds or longer. The drying time is, for example, 600 seconds or shorter, preferably 500 seconds or shorter.

[0162] This results in a dried coating film of the aqueous coating agent, and as a result, an article comprising the substrate and the dried coating film is obtained. Such an article has excellent oil resistance because it comprises a coating film of the above-mentioned aqueous coating agent. [Example]

[0163] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Form for Carrying Out the Invention."

[0164] <Measurement method> (1) Acid value The acid value of the polyester resin component was measured in accordance with JIS K 5601-2-1 (1999).

[0165] (2) Hydroxyl value The hydroxyl value of the polyester resin component was measured in accordance with JIS K 0070 (1992).

[0166] (3) Content of components with a molecular weight of 500 or less The content of components with a molecular weight of 500 or less was measured by the following method. Specifically, the polyester resin component was dissolved in tetrahydrofuran to obtain a 1.0 g / L sample. The molecular weight distribution of the sample was then obtained using a gel permeation chromatograph (GPC) equipped with a refractive index detector (RID).

[0167] Thereafter, the content of components having a molecular weight of 500 or less was calculated from the obtained chromatogram (chart) using standard polystyrene as a calibration curve. The measuring device and measuring conditions are shown below.

[0168] Data processing device: Agilent 1260 Infinity II (Agilent) Refractive index detector: RI detector (G7162A) built into Agilent 1260 Infinity II Column: PL gelmixed-B 7.5 x 300 mm (Agilent), 3 bottles Mobile phase: tetrahydrofuran Column flow rate: 1.0 ml / min Sample concentration: 2.0 g / L Injection volume: 10μL Measurement temperature: 30℃ Molecular weight marker: Standard polystyrene (Agilent EasiCal Polystyrene Standards PS-1)

[0169] Synthesis Example 1 (Resin 1) 39.6 parts of gum rosin was placed in a four-neck flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer while nitrogen gas was blown into the flask, and the temperature was raised to 210°C. Next, 12.9 parts of fumaric acid was added to the flask, and the mixture was stirred at 210°C for approximately 30 minutes. This caused the gum rosin and fumaric acid to undergo a Diels-Alder reaction, yielding a first product (first step).

[0170] Next, 24.3 parts of adipic acid and 23.2 parts of glycerin were added to the flask, and the contents were subjected to an esterification reaction at 190° C. for about 8 hours, thereby obtaining a second product (second step).

[0171] The second product was designated as a polyester resin component containing a rosin-modified polyester resin (hereinafter referred to as resin 1). The acid value of resin 1 was 125 mg KOH / g. The hydroxyl value of resin 1 was 134 mg KOH / g. Furthermore, the content of components having a molecular weight of 500 or less in resin 1 was 18 mass%.

[0172] Synthesis Examples 9 to 10, 14, 17 and 19 (Resins 9 to 10, 14, 17 and 19) Resins 9 to 10, 14, 17 and 19 were obtained in the same manner as in Synthesis Example 1, except that the formulations were changed as shown in Tables 1 to 4. The reaction conditions were set as shown in Tables 1 to 4.

[0173] Synthesis Example 2 (Resin 2) In a four-neck flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, linseed oil (iodine value 180 mg / 100 m 17.8 parts of linseed oil (g), 18.1 parts of glycerin, and 0.1 parts of lithium acetate (catalyst) were added, and the temperature was raised to 255°C. The mixture was then stirred at 255°C for 3 hours. As a result, the glycerin was modified with linseed oil, and linseed oil-modified glycerin was obtained (modification step).

[0174] Meanwhile, 37.5 parts of gum rosin was placed in a four-neck flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer, and the temperature was raised to 210°C. Next, 13.5 parts of fumaric acid was added to the flask, and the mixture was stirred at 210°C for approximately 30 minutes. This caused the gum rosin and fumaric acid to undergo a Diels-Alder reaction, yielding a first product (first step).

[0175] Next, linseed oil-modified glycerin (35.9 parts in total) and 13.1 parts of adipic acid were added to the flask, and the contents were subjected to an esterification reaction at 190° C. for about 8 hours, thereby obtaining a second product (second step).

[0176] The second product was designated as a polyester resin component containing a rosin-modified polyester resin (hereinafter referred to as resin 2). The acid value of resin 2 was 122 mg KOH / g. The hydroxyl value of resin 2 was 130 mg KOH / g. In resin 2, the content of components having a molecular weight of 500 or less was 15 mass%.

[0177] Synthesis Examples 3 to 8 and 15 to 16 (Resins 3 to 8 and 15 to 16) Resins 3 to 8 and 15 to 16 were obtained in the same manner as in Synthesis Example 2, except that the formulations were changed as shown in Tables 1 to 4. The reaction conditions were set as shown in Tables 1 to 4.

[0178] Synthesis Example 11 (Resin 11) 37.5 parts of gum rosin was placed in a four-neck flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer while nitrogen gas was blown in, and the temperature was raised to 210°C. Next, 12.2 parts of fumaric acid was added to the flask, and the mixture was stirred at 210°C for approximately 30 minutes. This caused the gum rosin and fumaric acid to undergo a Diels-Alder reaction, yielding a first product (first step).

[0179] Next, 12.1 parts of adipic acid, 19.7 parts of glycerin, and tall oil fatty acid (iodine value 140 mg / 100 m g) was added, and the contents were subjected to an esterification reaction at 190° C. for about 8 hours, thereby obtaining a second product (second step).

[0180] The second product was designated as a polyester resin component containing a rosin-modified polyester resin (hereinafter referred to as resin 11). The acid value of resin 11 was 120 mg KOH / g. The hydroxyl value of resin 11 was 140 mg KOH / g. In resin 11, the content of components having a molecular weight of 500 or less was 21 mass%.

[0181] Synthesis Examples 12-13 and 18 (Resins 12-13 and 18) Resins 12 to 13 and 18 were obtained in the same manner as in Synthesis Example 11, except that the formulations were changed to those shown in Tables 1 to 4. The reaction conditions were set to those shown in Tables 1 to 4.

[0182] Reference Examples 1, 9, 10, 12, and 14, Examples 2 to 8, 11, 13, and 15 to 16 and Comparative Examples 1 to 3 Aqueous coating agents 1 to 16 were obtained according to the formulations shown in Tables 1 to 4. That is, 30 parts of resin, 10 parts of 25% aqueous ammonia solution, and 60 parts of distilled water were placed in an Erlenmeyer flask equipped with a reflux condenser, and stirred for approximately 2 hours at 70°C. This neutralized and dissolved the resin, yielding an aqueous solution.

[0183] Each aqueous coating agent was applied to a 250 g / m paperboard using a 6 μm bar coater. The aqueous coating agent was then dried to obtain a coating film of the aqueous coating agent. An article (coated paper) having a coating film of the aqueous coating agent was also obtained.

[0184] <Oil resistance evaluation> The oil resistance of the surface of the article was evaluated using a standard "kit" type test according to the Technical Association of the Pulp and Paper Industry (TAPPI) test method TAPPI T559cm-02 test. Ratings were given on a 10-point scale from 1 to 10. A rating of 3 or higher was considered excellent oil resistance.

[0185] <Styrene-(meth)acrylic copolymer> Manufacturing Example 1 A monomer composition was obtained by mixing 104 parts of styrene, 17 parts of methacrylic acid, 34 parts of n-butyl methacrylate, 138 parts of 2-ethylhexyl acrylate, 52 parts of methyl methacrylate, and 2 parts of n-dodecyl mercaptan as a chain transfer agent. Separately from the above, 4 parts of potassium persulfate was dissolved in 256 parts of water to prepare an aqueous polymerization initiator solution.

[0186] Then, 360 parts of water and 12 parts of sodium dodecylbenzenesulfonate (Neopelex G-25, manufactured by Kao Corporation) as an emulsifier were placed in a four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, a water divider, and a nitrogen gas inlet tube, and the mixture was heated to 88°C with stirring.

[0187] The monomer composition and the aqueous polymerization initiator solution were each continuously injected into the flask over a period of 6 hours while maintaining the temperature at 90°C or less to polymerize, followed by aging for 30 minutes. The mixture was then heated to 95°C to complete the polymerization, and then cooled to 40°C.

[0188] Thereafter, 1 part of 28% aqueous ammonia was added to the flask to neutralize the solution, yielding an aqueous solution of an alkali salt of a styrene-(meth)acrylic copolymer with a solids concentration of 35.5% by mass and a viscosity of 21 mPa·s (25° C.).

[0189] Manufacturing Example 2 A monomer composition was obtained by mixing 104 parts of styrene, 17 parts of methacrylic acid, 34 parts of n-butyl methacrylate, 138 parts of 2-hydroxyethyl methacrylate, and 52 parts of methyl methacrylate with 2 parts of n-dodecyl mercaptan as a chain transfer agent.

[0190] Except for the above, the same method as in Production Example 1 was used to obtain an aqueous solution of an alkali salt of a styrene-(meth)acrylic copolymer having a solids concentration of 35.2% by mass and a viscosity of 25 mPa·s (25° C.).

[0191] <Wax> Preparation example 1 A commercially available wax emulsion (trade name: Dijet H, manufactured by Goo Chemical Industry Co., Ltd.) was prepared.

[0192] Reference Examples 17-18, 21-22, and Examples 19-20 Aqueous coating agents 17 to 22 were obtained according to the formulations shown in Table 5. That is, a polyester resin component and a styrene-(meth)acrylic copolymer and / or wax were mixed together to obtain the solid content parts by mass shown in Table 5, thereby obtaining a resin mixture.

[0193] Next, 30 parts of the resin mixture, 10 parts of 25% aqueous ammonia solution, and 60 parts of distilled water were placed in a conical flask equipped with a reflux condenser and stirred at 70°C for approximately 2 hours. This neutralized the resin mixture and dissolved it to obtain an aqueous solution. The solids concentration, pH, and viscosity are shown in Table 5. As a result, aqueous coating agents 17 to 22 were obtained.

[0194] Each aqueous coating agent was adjusted to a temperature of 25°C and coated onto a 250 g / m2 paperboard using a bar coater No. 22. The aqueous coating agent was then dried to obtain a coating film of the aqueous coating agent. An article (coated paper) provided with a coating film of the aqueous coating agent was also obtained. The amount of solid content (resin component) attached was 7 to 8 g / m2. 2 It was.

[0195] The coated paper was conditioned in a constant temperature and humidity environment (22°C, relative humidity 50%) for 12 hours, after which the coated paper was subjected to an evaluation of oil resistance.

[0196] <Oil resistance evaluation> The oil resistance of the surface of the article was evaluated using a standard "kit" type test according to the Technical Association of the Pulp and Paper Industry (TAPPI) test method TAPPI T559cm-02 test. The rating is on a 12-point scale from 1 to 12. A rating of 3 or higher was considered to be excellent in oil resistance.

[0197] [Table 1]

[0198] [Table 2]

[0199] [Table 3]

[0200] [Table 4]

[0201] [Table 5]

[0202] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are intended to be included in the scope of the following claims. [Industrial Applicability]

[0203] The aqueous coating agent, article, and method for producing a rosin-modified polyester resin of the present invention are suitable for use in the field of coating various substrates.

Claims

1. Contains an aqueous medium and a polyester resin component, the polyester resin component includes a rosin-modified polyester resin that is a reaction product of raw material components including (A) rosins, (B) an α,β-unsaturated dicarboxylic acid, (C) a polyol, and (D) fats and / or oils and / or fatty acids; The acid value of the polyester resin component is 60 mgKOH / g or more and 180 mgKOH / g or less, the hydroxyl value of the polyester resin component is 20 mgKOH / g or more and 180 mgKOH / g or less; The aqueous coating agent has a content of the (D) oils and / or fatty acids of 10% by mass or more and 30% by mass or less relative to the total amount of the raw material components.

2. In the raw material components, 2. The aqueous coating agent according to claim 1, wherein the content of the α,β-unsaturated dicarboxylic acid (B) is 70 moles or more and 150 moles or less per 100 moles of the rosin (A).

3. 2. The aqueous coating agent according to claim 1, wherein the α,β-unsaturated dicarboxylic acid (B) comprises fumaric acid and / or maleic anhydride.

4. 2. The aqueous coating agent according to claim 1, further comprising a styrene-(meth)acrylic copolymer.

5. The aqueous coating agent according to claim 1 , further comprising a wax.

6. An article comprising a coating film of the aqueous coating agent according to claim 1.

7. A method for producing a polyester resin component containing a rosin-modified polyester resin, comprising: The acid value of the polyester resin component is 60 mgKOH / g or more and 180 mgKOH / g or less, the hydroxyl value of the polyester resin component is 20 mgKOH / g or more and 180 mgKOH / g or less; the rosin-modified polyester resin is a reaction product of raw material components including (A) rosins, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, and (D) fats and / or oils and fatty acids; The content of the (D) oils and / or fatty acids is 10% by mass or more and 30% by mass or less with respect to the total amount of the raw material components, A first step of reacting (A) a rosin with (B) an α,β-unsaturated dicarboxylic acid to obtain a first product; After the first step, a second step is carried out in which the first product is reacted with a polyol (C) to obtain a second product. Equipped with The (D) oils and / or fatty acids are In the second step, the first product and the polyol (C) are reacted together, and / or Before the second step, the polyol (C) is modified, The method for producing a polyester resin component, wherein the reaction temperature in the second step is 230°C or lower.

8. A modification step of modifying the (C) polyol with (D) an oil or fat and / or a fatty acid is provided before the second step, The method for producing a polyester resin component according to claim 7 , wherein the reaction temperature in the modification step is 230° C. or higher and 300° C. or lower.

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