Aqueous coating agent, article, and method for producing rosin-modified polyester resin

Abstract

An aqueous coating agent contains an aqueous medium and a polyester resin component. The polyester resin component contains a rosin-modified polyester resin that is a reaction product of raw material components containing (A) a rosin, (B) an α,β-unsaturated dicarboxylic acid, and (C) a polyhydric alcohol. The acid value of the polyester resin component is 60 mg KOH / g or more and 180 mg KOH / g or less. The hydroxyl value of the polyester resin component is 20 mg KOH / g or more and 180 mg KOH / g or less.

Description

Technical Field

[0001] This invention relates to water-based coating agents, articles, and methods for manufacturing rosin-modified polyester resins. Background Technology

[0002] Water-based coating agents are known in the past. Water-based coating agents are applied to a substrate to form a coating film.

[0003] Aqueous coating agents, for example, contain a resin obtained by the following method: First, 185.2 g of fatty acid dimer, 1453.3 g of pine rosin, 6 g of phenol sulfonic acid, and 185.2 g of polyglycerol are mixed. Next, the mixture is heated to 250–270°C to allow it to react until the acid value reaches 6 mg KOH / g. This yields a resin coating film with excellent water resistance (see, for example, Patent Document 1 (Example 1)).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: U.S. Patent Application Publication No. 2013 / 0197152 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] On the other hand, depending on the field in which water-based coating agents are used, there are sometimes cases where excellent oil resistance is required instead of water resistance.

[0009] The present invention relates to an aqueous coating agent capable of forming a coating film with excellent oil resistance, an article comprising a coating film obtained using the aqueous coating agent, and a method for manufacturing a rosin-modified polyester resin contained in the aqueous coating agent.

[0010] Methods for solving problems

[0011] The present invention [1] includes an aqueous coating agent containing an aqueous medium and a polyester resin component, wherein the aforementioned polyester resin component contains a rosin-modified polyester resin, which is a reaction product containing (A) rosin, (B) α,β-unsaturated dicarboxylic acid and (C) polyol, wherein the acid value of the aforementioned polyester resin component is 60 mg KOH / g or more and 180 mg KOH / g or less, and the hydroxyl value of the aforementioned polyester resin component is 20 mg KOH / g or more and 180 mg KOH / g or less.

[0012] The present invention [2] includes the aqueous coating agent described above [1], wherein, relative to 100 moles of the aforementioned (A) rosin, the content of the aforementioned (B) α,β-unsaturated dicarboxylic acid is more than 70 moles and less than 150 moles.

[0013] The present invention [3] includes the aqueous coating agent described in [1] or [2] above, wherein the aforementioned (B) α,β-unsaturated dicarboxylic acid contains fumaric acid and / or maleic anhydride.

[0014] The present invention [4] includes any one of the above [1] to [3] water-based coating agents, wherein the aforementioned raw material components further contain (D) oils and / or fatty acids.

[0015] The present invention [5] includes the aqueous coating agent described above [4], wherein the content of the aforementioned (D) oil and / or fatty acid is 10% by mass or more and 30% by mass or less relative to the total amount of the aforementioned raw material components.

[0016] The present invention [6] includes any one of the above [1] to [5] aqueous coating agents, which further contain styrene-(meth)acrylic acid copolymer.

[0017] The present invention [7] includes any one of the above [1] to [6] aqueous coating agents, which further contain wax.

[0018] The present invention [8] includes an article comprising a coating film of any of the aqueous coating agents described in any one of [1] to [7] above.

[0019] The present invention [9] includes a method for manufacturing a rosin-modified polyester resin, comprising a first step of reacting (A) rosin with (B) α,β-unsaturated dicarboxylic acid to obtain a first product, and a second step of reacting the first product with (C) a polyol after the first step to obtain a second product, wherein the reaction temperature of the second step is 230°C or below.

[0020] The present invention

[10] includes a method for manufacturing rosin-modified polyester resin as described above [9], comprising a modification step prior to the aforementioned second step, wherein the aforementioned (C) polyol is modified with (D) oil and / or fatty acid, and the reaction temperature of the aforementioned modification step is 230°C or higher and 300°C or lower.

[0021] Invention Effects

[0022] In the aqueous coating agent of the present invention, the acid value of the polyester resin component containing rosin-modified polyester resin is within a predetermined range, and the hydroxyl value of the polyester resin component containing rosin-modified polyester resin is within a predetermined range. Therefore, the aqueous coating agent of the present invention can form a coating film with excellent oil resistance.

[0023] The articles of the present invention comprise a coating film of the above-mentioned water-based coating agent, and therefore have excellent oil resistance.

[0024] According to the method for manufacturing rosin-modified polyester resin of the present invention, a rosin-modified polyester resin with excellent oil resistance can be obtained. Detailed Implementation

[0025] 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.

[0026] 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. Water is preferred as an aqueous medium.

[0027] The polyester resin composition contains rosin-modified polyester resin as the main component. It should be noted that the main component is a component contained in a proportion of 75% by mass or more, preferably 80% by mass or more, relative to the total amount. Furthermore, as detailed below, the polyester resin composition may contain unreacted raw material components as secondary components.

[0028] Rosin-modified polyester resin is a polyester resin modified with rosin. Rosin-modified polyester resin is a reaction product of the raw material components. The raw material components contain (A) rosin, (B) α,β-unsaturated dicarboxylic acids, and (C) polyols as essential components.

[0029] More specifically, the raw material components consist, for example, of (A) rosin, (B) α,β-unsaturated dicarboxylic acid, and (C) polyol. In this case, the total amount of (A) rosin, (B) α,β-unsaturated dicarboxylic acid, and (C) polyol is 100% by mass relative to the raw material components.

[0030] (A) Rosin is a plant-derived component. Therefore, rosin-modified polyester resins can contribute to carbon neutrality. More specifically, (A) rosin is a compound derived from pine trees. There are no particular restrictions on the type of pine tree; examples include Norfolk pine, slash pine, and Masson pine. They can be used alone or in combination of two or more.

[0031] As for (A) rosin, there are no particular limitations, and well-known unmodified rosin and / or its derivatives can be listed. Examples of unmodified rosin include, for example, crude rosin and refined rosin. Examples of crude rosin include, for example, resin rosin, tall oil rosin, and wood rosin. Examples of refined rosin include, for example, refined products of crude rosin. Examples of rosin derivatives include, for example, hydrogenated rosin, disproportionated rosin, and polymerized rosin. They can be used alone or in combination of two or more. It should be noted that there are no particular limitations on the origin of rosin; for example, China, Vietnam, Indonesia, and Brazil can be listed. They can be used alone or in combination of two or more.

[0032] From the viewpoint of film-forming properties and water resistance, unmodified rosin is preferred as (A) rosin, and resin rosin is more preferred.

[0033] From the viewpoints of film-forming properties, water resistance, and anti-sticking properties, the content of rosin (A) relative to the total amount of raw material components is, 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. Furthermore, from the viewpoints of film-forming properties, water resistance, and anti-sticking properties, the content of rosin (A) relative to the total amount of raw material components is, 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.

[0034] (B)α,β-unsaturated dicarboxylic acids are components that improve the oil resistance of coatings. Examples of (B)α,β-unsaturated dicarboxylic acids include fumaric acid, maleic acid, itaconic acid, citraconic acid, and their anhydrides. Examples of acid anhydrides include maleic anhydride, itaconic anhydride, and citraconic anhydride. They can be used alone or in combination of two or more.

[0035] As (B) α,β-unsaturated dicarboxylic acids, fumaric acid and maleic anhydride are preferred examples, and fumaric acid is more preferred. That is, (B) α,β-unsaturated dicarboxylic acids preferably contain fumaric acid and / or maleic anhydride, and more preferably contain fumaric acid.

[0036] From the viewpoint of oil resistance, the content of (B) α,β-unsaturated dicarboxylic acid relative to the total amount of raw material components is, for example, 3% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more. Furthermore, from the viewpoint of oil resistance, the content of (B) α,β-unsaturated dicarboxylic acid relative to the total amount of raw material components is, 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.

[0037] Furthermore, from the viewpoint of oil resistance, the content of (B) α,β-unsaturated dicarboxylic acid relative to 100 moles of (A) rosin is, 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. Furthermore, from the viewpoint of oil resistance, the content of (B) α,β-unsaturated dicarboxylic acid relative to 100 moles of (A) rosin is, for example, 200 moles or less, preferably 150 moles or less, and more preferably 120 moles or less.

[0038] When the concentration of (B) α,β-unsaturated dicarboxylic acids is below the above range, there is a higher concentration of unreacted (A) rosin compounds, resulting in decreased oil resistance. Furthermore, when the concentration of (B) α,β-unsaturated dicarboxylic acids exceeds the above range, there is a higher concentration of unreacted (B) α,β-unsaturated dicarboxylic acids, resulting in decreased film-forming properties, and consequently, decreased oil resistance.

[0039] Examples of (C) polyols include diols, triols, and alcohols with four or more nucleotides. Examples of diols include straight-chain alkyl glycols, branched-chain alkyl glycols, and ether glycols. Examples of straight-chain alkyl glycols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Examples of branched-chain alkyl glycols include propylene glycol, 1,3-butanediol, 1,2-butanediol, 3-methyl-1,5-pentanediol, and 2,6-dimethyl-1-octene-3,8-diol. Examples of ether glycols include diethylene glycol, triethylene glycol, and dipropylene glycol.

[0040] Furthermore, examples of diols include 1,4-dihydroxy-2-butene, isosorbide, cyclohexanediol, cyclohexanediol, dimethyloltricyclodecane, bisphenol A, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol S, hydrogenated catechol, hydrogenated resorcinol, hydrogenated hydroquinone, and dicyclopentadiene diallyl copolymer. Examples of triols include glycerol, trimethylolethane, trimethylolpropane, trimethylolhexane, and trimethyloloctane. Examples of alcohols with four or more octyl groups include 4- to 8-ols. Examples of 4- to 8-ols include pentaerythritol, diglycerol, dimethylolpropane, sorbitan, sorbitol, dipentaerythritol, inositol, and tripentaerythritol. They can be used alone or in combination of two or more.

[0041] From the viewpoint of oil resistance, as (C) polyols, trihydric alcohols and alcohols with four or more nucleotides are preferred, trihydric alcohols are more preferred, trimethylolpropane, glycerol and pentaerythritol are even more preferred, and glycerol is particularly preferred.

[0042] Furthermore, the number of carbon atoms in (C) polyol is, for example, 2 or more, preferably 3 or more. Furthermore, the number of carbon atoms in (C) polyol is, for example, 30 or less, preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less.

[0043] From the viewpoint of oil resistance, the content of (C) polyol relative to the total amount of raw material components is, for example, 5% by mass or more, preferably 8% by mass or more, more preferably 12% by mass or more, further preferably 13% by mass or more, and particularly preferably 15% by mass or more. Furthermore, from the viewpoint of oil resistance, the content of (C) polyol relative to the total amount of raw material components is, for example, 40% by mass or less, preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less.

[0044] The raw material composition may contain (D) oils and / or fatty acids as an optional component. If the raw material composition contains (D) oils and / or fatty acids, the oil resistance of the coating film can be improved.

[0045] More specifically, the raw material components are, for example, composed of (A) rosin, (B) α,β-unsaturated dicarboxylic acid, (C) polyol, and (D) oils and / or fatty acids. In this case, the total amount of (A) rosin, (B) α,β-unsaturated dicarboxylic acid, (C) polyol, and (D) oils and / or fatty acids is 100% by mass relative to the raw material components.

[0046] Examples of oils and fats include flaxseed oil, grapefruit oil, pistachio oil, rice bran oil, safflower oil, almond oil, cottonseed oil, sesame oil, corn oil, watermelon seed oil, soybean oil, apple oil, sunflower oil, cactus oil, tall oil, walnut oil, tung oil, and castor oil. Furthermore, examples of fatty acids include those derived from the aforementioned oils and fats. More specifically, examples of fatty acids include flaxseed oil fatty acids, grapefruit oil fatty acids, pistachio oil fatty acids, rice bran oil fatty acids, safflower oil fatty acids, almond oil fatty acids, cottonseed oil fatty acids, sesame oil fatty acids, corn oil fatty acids, watermelon seed oil fatty acids, soybean 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.

[0047] From the viewpoint of softness, water resistance, and oil resistance, the content of (D) oils and / or fatty acids (the total amount of which are used together) relative to the total amount of raw material components is, for example, 0% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, further preferably 15% by mass or more, and particularly preferably 17% by mass or more. Furthermore, from the viewpoint of softness, water resistance, and oil resistance, the content of (D) oils and / or fatty acids (the total amount of which are used together) relative to the total amount of raw material components is, for example, 40% by mass or less, preferably 35% by mass or less, more preferably 30% by mass or less, and further preferably 25% by mass or less.

[0048] From the viewpoint of oil resistance, oils and / or fatty acids having a specified iodine value are preferably listed as (D) fats and / or fatty acids. More specifically, from the viewpoint of oil resistance, the iodine value of (D) fats and / or fatty acids is, for example, 50 mg / 100 mg or more, preferably 70 mg / 100 mg or more, and more preferably 100 mg / 100 mg or more.

[0049] From the viewpoint of oil resistance, it is further preferred that the (D) oils and / or fatty acids contain oils and / or fatty acids with an iodine value of 100 mg / 100 mg or more as the main components. It should be noted that "main component" refers to 80% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. That is, relative to the total amount of (D) oils and / or fatty acids, the proportion of oils and / or fatty acids with an iodine value of 100 or more is, for example, 80% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. It is particularly preferred that the (D) oils and / or fatty acids consist of oils and / or fatty acids with an iodine value of 100 mg / 100 mg or more.

[0050] Oils and / or fatty acids with an iodine value of 100mg / 100mg or higher include, for example, flaxseed oil, grapefruit oil, pistachio oil, rice oil, safflower oil, almond oil, cottonseed oil, sesame oil, corn oil, watermelon seed oil, soybean oil, apple oil, sunflower oil, cactus oil, tall oil, walnut oil, tung oil, castor oil, and fatty acids derived from these oils.

[0051] It should be noted that the iodine value is determined using the standard oil and fat analysis test method (Japan Oil Chemistry Society) "2.3.4.1-1996 (Widmanstätten-cyclohexane method)". Specifically, in the determination of the iodine value, firstly, 0.15 g of the target vegetable oil is dissolved in 10 ml of cyclohexane. Next, 25 mL of Widmanstätten solution is added to this solution, and the mixture is left in the dark for approximately 1 hour. Then, the solution is titrated with 0.1 mol / L sodium thiosulfate standard solution.

[0052] Then, the iodine value is calculated based on the amount of sodium thiosulfate standard solution added at the endpoint.

[0053] In addition, the raw material may contain (E) other carboxylic acids as an optional component. (E) Other carboxylic acids are carboxylic acids other than (A) rosin compounds, (B) α,β-unsaturated dicarboxylic acids, and (D) oils and / or fatty acids.

[0054] More specifically, the raw material components consist, for example, (A) rosin, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, (D) oils and / or fatty acids, and (E) other carboxylic acids. In this case, the total amount of (A) rosin, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, (D) oils and / or fatty acids, and (E) other carboxylic acids is 100% by mass relative to the raw material components.

[0055] Furthermore, the raw material components, for example, consist of (A) rosin, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, and (E) other carboxylic acids. In this case, the total amount of (A) rosin, (B) α,β-unsaturated dicarboxylic acids, (C) polyols, and (E) other carboxylic acids is 100% by mass relative to the raw material components.

[0056] Other carboxylic acids (E) 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.

[0057] Examples of α,β-unsaturated monocarboxylic acids include acrylic acid and methacrylic acid. They can be used alone or in combination of two or more.

[0058] The proportion of α,β-unsaturated monocarboxylic acid relative to the total amount of 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. Furthermore, from the viewpoint of oil resistance, the proportion of α,β-unsaturated monocarboxylic acid relative to the total amount of 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.

[0059] Examples of carboxylic acids without an unsaturated bond between the α- and β-carbons include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, oxaloacetic acid, methylmalonic acid, dimethylmalonic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, methylglutaric acid, and dimethylmalonic acid. Glutaric acid, diethylene glycol, 1,3-propanone dicarboxylic acid, ketoglutaric acid, cyclopropane-1,1-dicarboxylic acid, cyclobutane-1,1-dicarboxylic acid, cyclohexane-1,1-dicarboxylic acid, 2-oxoadipic acid, 4-oxohepanilic acid, 5-oxonanediic acid, phenylene dioxoacetic acid, dihydroindene-2,2-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexanedicarboxylic acid, trimellitic acid, and benzopyrene. They can be used alone or in combination of two or more.

[0060] Succinic acid and adipic acid are preferred examples of carboxylic acids that do not have an unsaturated bond between the α- and β-carbons. Utilizing carboxylic acids without an unsaturated bond between the α- and β-carbons can improve oil resistance.

[0061] From the viewpoint of oil resistance, the proportion of carboxylic acids without unsaturated bonds between the α-carbon and β-carbon positions relative to the total amount of 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. Furthermore, from the viewpoint of oil resistance, the proportion of carboxylic acids without unsaturated bonds between the α-carbon and β-carbon positions relative to the total amount of 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.

[0062] Furthermore, as other carboxylic acids (E), the aforementioned α,β-unsaturated monocarboxylic acids and carboxylic acids without unsaturated bonds between the α-carbon and β-carbon can be used together. In this case, relative to the total amount of the raw material components, the total amount of α,β-unsaturated monocarboxylic acids and carboxylic acids without unsaturated bonds between the α-carbon and β-carbon is, for example, 0% by mass or more, preferably 5% by mass or more. Furthermore, relative to the total amount of the raw material components, the total amount of α,β-unsaturated monocarboxylic acids and carboxylic acids without unsaturated bonds between the α-carbon and β-carbon is, for example, 60% by mass or less, preferably 40% by mass or less.

[0063] Furthermore, rosin-modified polyester resin can be obtained as a reaction product of the above-mentioned raw material components. In this reaction, for example, the above-mentioned raw material components can react simultaneously; alternatively, the raw material components can undergo a multi-stage reaction. It is preferable that the above-mentioned raw material components undergo a multi-stage reaction.

[0064] In a multi-stage reaction, the reaction order is not particularly restricted. Preferably, (A) rosin and (B) α,β-unsaturated dicarboxylic acid are reacted first to obtain the first product. Next, the first product is reacted with (C) polyol to obtain the second product containing rosin-modified polyester resin.

[0065] More specifically, in this method, (A) rosin and (B) α,β-unsaturated dicarboxylic acid are first combined in the above proportion. Then, (A) rosin and (B) α,β-unsaturated dicarboxylic acid are reacted. This yields the first product (first step).

[0066] More specifically, in step 1, the double bond in (B) α,β-unsaturated dicarboxylic acid is subjected to a Diels-Alder reaction with the conjugated double bond in (A) rosin.

[0067] From the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction temperature of the first step is, for example, 150°C or higher, preferably 170°C or higher, and more preferably 180°C or higher. Furthermore, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction temperature of the first step is, for example, 230°C or lower, preferably 220°C or lower, and more preferably 200°C or lower.

[0068] From the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction time of the first step is, for example, 0.1 hours or more, preferably 0.5 hours or more. Furthermore, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction time of the first step is, for example, 5 hours or less, preferably 3 hours or less.

[0069] It should be noted that in the first step, a known reaction catalyst may be added in an appropriate proportion as needed. Furthermore, in the first step, the raw material components may react in a solvent-free environment, or in the presence of a known solvent.

[0070] This yields the first product. The first product contains a tertiary carboxyl group from (A) rosin (the tertiary carboxyl group of the rosin acid monomer) and a secondary carboxyl group from (B) α,β-unsaturated dicarboxylic acid.

[0071] Next, in this method, the first product is combined with the (C) polyol in the above proportions. Then, the first product is reacted with the (C) polyol. This yields the second product (step 2).

[0072] More specifically, in the second step, the carboxyl group contained in the first product is subjected to an esterification reaction with the hydroxyl group contained in the (C) polyol.

[0073] From the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction temperature of the second step is, 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. Furthermore, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction temperature of 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.

[0074] If the reaction temperature is within the above range, the reaction of the tertiary carboxyl group from (A) rosin can be suppressed, while the reaction of the secondary carboxyl group from (B) α,β-unsaturated dicarboxylic acid can proceed. Therefore, film-forming properties and oil resistance are improved.

[0075] More specifically, when the reaction temperature exceeds the upper limit mentioned above, the tertiary carboxyl groups from (A) rosin and the hydroxyl groups from (C) polyols readily form a mesh structure in the polyester resin component. Therefore, if rosin-modified polyester resin is used in water-based coatings, oil resistance decreases. Furthermore, when the reaction temperature is below the lower limit mentioned above, the reaction cannot proceed fully, resulting in a decrease in oil resistance.

[0076] From the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction time of the second step is, for example, 1 hour or more, preferably 3 hours or more. Furthermore, from the viewpoint of adjusting the acid value and hydroxyl value of the rosin-modified polyester resin, the reaction time of the second step is, for example, 48 hours or less, preferably 24 hours or less. In addition, in this reaction, the condensation water generated by the esterification reaction can be distilled off using known methods as needed.

[0077] Furthermore, in the second step, (D) fats and / or fatty acids can be added together with the first product and (C) polyol in the above proportions as needed to allow them to react. More specifically, the carboxyl groups contained in (D) fats and / or fatty acids can be esterified with the hydroxyl groups contained in (C) polyol.

[0078] Furthermore, in the second step, other carboxylic acids (E) can be added as needed, along with the first product and the (C) polyol, in the proportions described above, to react with it. More specifically, the carboxyl groups of the other carboxylic acids (E) can undergo an esterification reaction with the hydroxyl groups of the (C) polyol.

[0079] It should be noted that in the second step, a known reaction catalyst can be added in an appropriate proportion as needed. Furthermore, in the second step, the raw material components can react in a solvent-free environment, or in the presence of a known solvent.

[0080] This yields a second product. The second product is a resin composition containing rosin-modified polyester resin. The second product (resin composition) can be used as a polyester resin component in an aqueous coating agent.

[0081] In addition, when the raw material contains (D) oils and / or fatty acids, the (C) polyol can be modified with (D) oils and / or fatty acids (modification step) before the second step mentioned above.

[0082] The proportions in the modification process are set appropriately. For example, relative to 1 mole of (D) oil and / or fatty acid, the hydroxyl groups of (C) polyol are, for example, 3 moles or more, preferably 10 moles or more, for example, 50 moles or less, preferably 40 moles or less.

[0083] From the viewpoint of oil resistance and film-forming properties, the reaction temperature of the modification process is, for example, 230°C or higher, preferably 240°C or higher, and more preferably 250°C or higher. Furthermore, from the viewpoint of oil resistance and film-forming properties, the reaction temperature of the modification process 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 process may not proceed, and (D) oils and / or fatty acids may not be incorporated into the resin. Therefore, oil resistance and film-forming properties may decrease. Furthermore, if the reaction temperature is too high, a decomposition reaction may occur, leading to an increase in low molecular weight components. Therefore, oil resistance and film-forming properties may decrease.

[0084] From the viewpoint of oil resistance and film-forming properties, the reaction time of the modification process is, for example, 0.5 hours or more, preferably 1 hour or more. Furthermore, from the viewpoint of oil resistance and film-forming properties, the reaction time of the modification process is, for example, 20 hours or less, preferably 10 hours or less.

[0085] It should be noted that, during the modification process, known reaction catalysts can be added in appropriate proportions as needed. Furthermore, during the modification process, the raw material components can react in a solvent-free environment, or in the presence of known solvents.

[0086] Furthermore, according to the above method, (C) polyols modified with (D) oils and / or fatty acids are obtained. The (C) polyols modified with (D) oils and / or fatty acids are then used in the second step described above. That is, the first product undergoes an esterification reaction with the (C) polyols modified with (D) oils and / or fatty acids.

[0087] This yields a second product. The second product is a resin composition containing rosin-modified polyester resin. The second product (resin composition) can be used as a polyester resin component in an aqueous coating agent.

[0088] The weight-average molecular weight (converted from standard polystyrene) of the rosin-modified polyester resin is, for example, 1,000 or more, preferably 3,000 or more, and more preferably 5,000 or more. Furthermore, the weight-average molecular weight (converted from standard polystyrene) of the rosin-modified polyester resin is, for example, 100,000 or less, preferably 70,000 or less, and more preferably 50,000 or less.

[0089] Furthermore, from the viewpoint of film-forming properties and anti-sticking properties, the softening point (measured by the Mettler method) of the rosin-modified polyester resin is, for example, 70°C or higher, preferably 75°C or higher, and more preferably 80°C or higher. Furthermore, from the viewpoint of film-forming properties and anti-sticking properties, the softening point (measured by the Mettler method) of the rosin-modified polyester resin is, for example, 150°C or lower, preferably 130°C or lower, and more preferably 120°C or lower.

[0090] Furthermore, relative to the total amount of polyester resin, the content of rosin-modified polyester resin is, for example, 75% by mass or more, preferably 80% by mass or more. Furthermore, relative to the total amount of polyester resin, the content of rosin-modified polyester resin is, for example, 100% by mass or less, preferably 90% by mass or less.

[0091] It should be noted that the polyester resin composition may contain unreacted raw material components in addition to rosin-modified polyester resin. Examples of unreacted raw material components include (A) unreacted rosin derivatives, (B) unreacted α,β-unsaturated dicarboxylic acids, (C) unreacted polyols, (D) unreacted oils and / or fatty acids, and (E) other unreacted carboxylic acids. Unreacted raw material components may be removed from the resin composition as needed.

[0092] The molecular weight of the unreacted raw material component is typically 500 or less. Hereinafter, the unreacted raw material component will be referred to as a component with a molecular weight of 500 or less. The content of the component with 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, preferably 20% by mass or less. Furthermore, the content of the component with 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, preferably 10% by mass or more.

[0093] When the polyester resin composition contains an excessive amount of components with a molecular weight of less than 500, film-forming properties and oil resistance decrease. It should be noted that the proportion of components with a molecular weight of less than 500 was determined by gel permeation chromatography according to the examples described later.

[0094] From the viewpoint of oil resistance, the acid value of the polyester resin component is 60 mg KOH / g or higher, preferably 80 mg KOH / g or higher, more preferably 100 mg KOH / g or higher, and even more preferably 120 mg KOH / g or higher. Furthermore, from the viewpoint of oil resistance, the acid value of the polyester resin component is 180 mg KOH / g or lower, preferably 170 mg KOH / g or lower, more preferably 160 mg KOH / g or lower, even more preferably 150 mg KOH / g or lower, and particularly preferably 130 mg KOH / g or lower. It should be noted that the acid value of the polyester resin component is determined according to JIS K 5601-2-1 (1999).

[0095] From the viewpoint of oil resistance, the hydroxyl value of the polyester resin component is 20 mg KOH / g or more, preferably 40 mg KOH / g or more, more preferably 60 mg KOH / g or more, even more preferably 80 mg KOH / g or more, even more preferably 120 mg KOH / g or more, and particularly preferably 130 mg KOH / g or more. Furthermore, from the viewpoint of oil resistance, the hydroxyl value of the polyester resin component is 180 mg KOH / g or less, preferably 170 mg KOH / g or less, more preferably 160 mg KOH / g or less, even more preferably 150 mg KOH / g or less, and particularly preferably 140 mg KOH / g or less. It should be noted that the hydroxyl value is determined according to JIS K0070 (1992).

[0096] In addition, in order to adjust the acid value and hydroxyl value of the polyester resin components to the above range, for example, the proportion of raw material components is adjusted to the above ratio and the reaction temperature and reaction time are adjusted to the above conditions.

[0097] Furthermore, by dissolving and / or dispersing the aforementioned polyester resin components in an aqueous medium, an aqueous coating agent is obtained.

[0098] The ratio of the aqueous medium to the polyester resin component is appropriately set according to the purpose and application. For example, relative to the total amount of the aqueous medium and polyester resin component, the aqueous medium is, for example, 5% by mass or more, preferably 10% by mass or more. Furthermore, relative to the total amount of the aqueous medium and polyester resin component, the aqueous medium is, for example, 80% by mass or less, preferably 70% by mass or less. Furthermore, relative to the total amount of the aqueous medium and polyester resin component, the polyester resin component is, for example, 20% by mass or more, preferably 30% by mass or more. Furthermore, relative to the total amount of the aqueous medium and polyester resin component, the polyester resin component is, for example, 95% by mass or less, preferably 90% by mass or less. If the ratio of the aqueous medium to the polyester resin component is within the above range, a sharp increase in viscosity can be suppressed, and the productivity, coatability, and drying properties of the water-based coating agent can be improved.

[0099] In addition to the water-based medium and polyester resin components, water-based coating agents also contain other resins. These other resins are those other than the polyester resin components mentioned above.

[0100] Other resins include, for example, 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, polyurethane resins, urea resins, melamine resins, and cellulose resins. These can be used alone or in combination of two or more.

[0101] Among other resins, styrene-modified acrylic resins are preferred. When water-based coatings contain styrene-modified acrylic resins, superior oil resistance can be obtained.

[0102] As a styrene-modified acrylic resin, more specifically, styrene-(meth)acrylic acid copolymers can be cited. From the viewpoint of oil resistance, water-based coatings preferably contain styrene-(meth)acrylic acid copolymers. It should be noted that (meth)acrylic acid refers to acrylic acid and / or methacrylic acid.

[0103] Styrene-(meth)acrylic acid copolymers are obtained, for example, by copolymerization of monomer components containing styrene and (meth)acrylic acid monomers capable of copolymerizing with styrene.

[0104] Examples of styrene-based substances include styrene, α-methylstyrene, vinyltoluene, ethylvinyltoluene, and chloromethylstyrene. These can be used alone or in combination of two or more. Styrene is a preferred example of a styrene-based substance.

[0105] The proportion of styrene relative to the total amount of monomer components is, for example, 10% by mass or more, preferably 20% by mass or more. Furthermore, the proportion of styrene relative to the total amount of monomer components is, for example, 80% by mass or less, preferably 70% by mass or less. If the proportion of styrene is within the above range, particularly excellent oil resistance can be obtained.

[0106] Examples of (meth)acrylic monomers include (meth)acrylates and (meth)acrylic monomers containing hydrophilic groups.

[0107] Examples of (meth)acrylates include alkyl groups having 1 to 24 carbon atoms. It should be noted that the alkyl group can be straight-chain or branched, and can also have a carbocyclic ring (aliphatic and / or aromatic ring). More specifically, examples of (meth)acrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, isodecanyl methacrylate, lauryl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate. They can be used alone or in combination of two or more.

[0108] As (meth)acrylates, methyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred examples, and methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate are more preferred examples. Furthermore, as (meth)acrylates, a combination of methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate is even more preferred. Furthermore, as (meth)acrylates, a combination of methyl methacrylate and butyl acrylate is even more preferred.

[0109] Examples of (meth)acrylic acid monomers containing hydrophilic groups include monomers containing hydroxyl groups, monomers containing carboxyl groups, monomers containing amino groups, monomers containing amide groups, and monomers containing heterocycles.

[0110] Examples of hydroxyl-containing monomers include 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxyethyl acrylamide, hydroxymethyl (meth)acrylamide, polyalkylene glycol (meth)acrylate, and glyceryl mono(meth)acrylate. They can be used alone or in combination of two or more. 2-hydroxyethyl methacrylate is a preferred example of a hydroxyl-containing monomer.

[0111] Examples of carboxyl-containing monomers include monomers containing monocarboxylic acids, monomers containing dicarboxylic acids, and acid anhydrides. Examples of monomers containing monocarboxylic acids include (meth)acrylic acid and crotonic acid. Examples of monomers containing dicarboxylic acids include maleic acid, fumaric acid, itaconic acid, and citraconic acid. Examples of acid anhydrides include anhydrides of monomers containing monocarboxylic acids and anhydrides of monomers containing dicarboxylic acids. They can be used alone or in combination of two or more. Among the carboxyl-containing monomers, monomers containing monocarboxylic acids are preferred, and methacrylic acid is more preferred.

[0112] Examples of amino-containing monomers include 2-(dimethylamino)ethyl (meth)acrylate and dimethylaminopropyl (meth)acrylamide. They can be used alone or in combination of two or more.

[0113] Examples of monomers containing amide groups include acrylamide, methacrylamide, N-isopropylacrylamide, N-vinylformamide, N-vinylacetamide, and N,N'-dimethylacrylamide. They can be used alone or in combination of two or more.

[0114] As heterocyclic monomers, N-vinylpyrrolidones can be listed as an example. They can be used alone or in combination of two or more.

[0115] (Meth)acrylic monomers containing hydrophilic groups can be used alone or in combination of two or more. Hydroxyl-containing monomers and carboxyl-containing monomers are preferred examples of (meth)acrylic monomers containing hydrophilic groups.

[0116] (Meth)acrylate monomers can be used alone or in combination of two or more. As (meth)acrylate monomers, (meth)acrylates and (meth)acrylate monomers containing hydrophilic groups are preferred examples, and combinations of (meth)acrylates and (meth)acrylate monomers containing hydrophilic groups are more preferred examples.

[0117] That is, the monomer components preferably contain styrene-based monomers, alkyl (meth)acrylates, and (meth)acrylate monomers containing hydrophilic groups.

[0118] Furthermore, the monomer components are more preferably styrene-based, alkyl (meth)acrylates, and monomers containing hydroxyl groups and / or monomers containing carboxyl groups.

[0119] Furthermore, the monomer components are preferably composed of styrene-based monomers, alkyl (meth)acrylates, and monomers containing hydroxyl groups and / or monomers containing carboxyl groups.

[0120] The proportion of (meth)acrylic acid monomers is set appropriately according to the purpose and use.

[0121] For example, when the (meth)acrylic monomer contains alkyl (meth)acrylate, the proportion (total) of alkyl (meth)acrylate relative to the total amount of the monomer component is, for example, 10% by mass or more, preferably 20% by mass or more. Furthermore, the proportion (total) of alkyl (meth)acrylate relative to the total amount of the monomer component is, for example, 90% by mass or less, preferably 80% by mass or less.

[0122] Furthermore, when the (meth)acrylic acid monomer contains a hydroxyl-containing monomer, the proportion (total amount) of the hydroxyl-containing monomer relative to the total amount of the monomer component is, for example, 5% by mass or more, preferably 10% by mass or more. Additionally, the proportion (total amount) of the hydroxyl-containing monomer relative to the total amount of the monomer component is, for example, 60% by mass or less, preferably 50% by mass or less.

[0123] Furthermore, when the (meth)acrylic acid monomer contains a carboxyl-containing monomer, the proportion (total amount) of the hydroxyl-containing monomer is, for example, 1% by mass or more, preferably 3% by mass or more, relative to the total amount of the monomer component. Additionally, the proportion (total amount) of the carboxyl-containing monomer is, for example, 20% by mass or less, preferably 10% by mass or less, relative to the total amount of the monomer component.

[0124] Furthermore, the content (total amount) of (meth)acrylic acid monomers is, for example, 20% by mass or more, preferably 30% by mass or more, relative to the total amount of monomer components. Furthermore, the content (total amount) of (meth)acrylic acid 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 monomer components.

[0125] Styrene-(meth)acrylic acid copolymers can be obtained, for example, by polymerizing the aforementioned monomer components using a known method. More specifically, for example, the aforementioned 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 aqueous solvents include the aforementioned aqueous media. During polymerization, the method of adding the monomer composition is not particularly limited; examples include simultaneous addition, partial addition, full addition, and partial addition.

[0126] Furthermore, chain transfer agents can be incorporated into the above polymerization process as needed. The weight-average molecular weight of the styrene-(meth)acrylic acid copolymer can be adjusted using chain transfer agents. Examples of chain transfer agents include lipophilic and water-soluble agents. Examples of lipophilic chain transfer agents include tert-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, dodecyl mercaptopropionate, cumene, carbon tetrachloride, α-methylstyrene dimer, and isoprene. Examples of water-soluble chain transfer agents include mercaptoethanol, mercaptoacetic acid, (meth)allyl sulfonic acid, and their salts. They can be used alone or in combination of two or more. It should be noted that the type and amount of chain transfer agent are appropriately determined according to the purpose and application.

[0127] Furthermore, polymerization initiators can be incorporated into the above polymerization process as needed. Examples of polymerization initiators include azo-based and peroxide-based initiators. Examples of azo-based initiators include azodimethylbutyronitrile, dimethylazodiisobutyrate, azobis(dimethyl)pentadionitrile, azodiisobutyronitrile, and azobis(2-amidinyl)propane hydrochloride. Examples of peroxide-based polymerization initiators include persulfate, hydrogen peroxide, benzoyl peroxide, tert-butyl peroxide, tert-butyl isopropyl peroxide monocarbonate, tert-butyl peroxide-2-ethylhexanoate, and cumene hydroperoxide. Additionally, redox initiators can also be used. They can be used alone or in combination of two or more. It should be noted that the type and amount of polymerization initiator are appropriately determined according to the purpose and application.

[0128] Furthermore, emulsifiers can be incorporated into the above polymerization process as needed. Examples of emulsifiers include low-molecular-weight emulsifiers and high-molecular-weight emulsifiers.

[0129] Examples of low-molecular-weight emulsifiers include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, ammonium polyoxyethylene alkylphenyl ether sulfate, sodium polyoxyethylene alkylsulfosuccinate, polyoxyethylene alkylene polycyclic phenyl ether sulfate salts (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 high-molecular-weight emulsifiers include polyvinyl alcohol and polyethylene oxide. They can be used alone or in combination of two or more.

[0130] Furthermore, reactive emulsifiers can also be listed as emulsifiers. Examples of reactive emulsifiers include, for example, sulfate salts of polyoxyethylene alkylphenyl ethers having one or more functional groups containing vinyl unsaturated bonds; sulfosuccinate salts of polyoxyethylene alkyl ethers having one or more functional groups containing vinyl unsaturated bonds; sulfate salts of polyoxyethylene alkyl ethers having one or more functional groups containing vinyl unsaturated bonds; sulfosuccinate salts of polyoxyethylene alkylphenyl ethers having one or more functional groups containing vinyl unsaturated bonds; sulfate salts of polyoxyethylene alkylphenyl ethers having one or more functional groups containing vinyl unsaturated bonds; and acidic phosphate (meth)acrylate salts having one or more functional groups containing vinyl unsaturated bonds. Examples of ester salts include sodium ester salts and ammonium ester salts. They can be used alone or in combination of two or more.

[0131] It should be noted that the type, amount, and timing of emulsifier formulation should be appropriately determined according to the purpose and application.

[0132] The polymerization conditions are not particularly limited and are appropriately set according to the type of monomer component, the type of polymerization initiator, and its amount. For example, the polymerization temperature is, for example, 80°C or higher, preferably 85°C or higher. Furthermore, the polymerization temperature is, for example, 120°C or lower, preferably 115°C or lower. Furthermore, the polymerization time is, for example, 2 hours or more, preferably 3 hours or more. Furthermore, the polymerization time is, for example, 6 hours or less, preferably 5 hours or less.

[0133] The above polymerization process yields solutions and / or dispersions of styrene-(meth)acrylic acid copolymers.

[0134] In solutions and / or dispersions of styrene-(meth)acrylic acid copolymers, the solid content concentration of the styrene-(meth)acrylic acid copolymer is, for example, 5% by mass or more, preferably 10% by mass or more. Furthermore, the solid content concentration of the styrene-(meth)acrylic acid copolymer is, for example, 50% by mass or less, preferably 40% by mass or less.

[0135] Furthermore, the viscosity (at 25°C) of the styrene-(meth)acrylic acid copolymer solution and / or dispersion is, for example, 1 mPa·s or more, preferably 5 mPa·s or more. Additionally, the viscosity (at 25°C) of the styrene-(meth)acrylic acid copolymer solution and / or dispersion is, for example, 500 mPa·s or less, preferably 200 mPa·s or less, more preferably 100 mPa·s or less. It should be noted that the viscosity was measured using a Type B viscometer based on JIS K 7117-1 (1999).

[0136] Furthermore, a neutralizing agent may be added as needed to the solution and / or dispersion of the styrene-(meth)acrylic acid copolymer. This yields an alkali metal salt solution of the styrene-(meth)acrylic acid copolymer. Ammonia may be cited as an example of a neutralizing agent.

[0137] The pH of the solution and / or dispersion of the styrene-(meth)acrylic acid copolymer is, for example, 3 or higher, preferably 4 or higher. Furthermore, the pH of the solution and / or dispersion of the styrene-(meth)acrylic acid copolymer is, for example, 10 or lower, preferably 9 or lower.

[0138] The glass transition temperature of the styrene-(meth)acrylic acid copolymer is, for example, -30°C or higher, preferably -10°C or higher. Furthermore, the glass transition temperature of the styrene-(meth)acrylic acid copolymer is, for example, 120°C or lower, preferably 100°C or lower. It should be noted that the glass transition temperature is calculated using the FOX formula.

[0139] The weight-average molecular weight of the styrene-(meth)acrylic acid copolymer is, for example, 5000 or more, preferably 10000 or more. Furthermore, the weight-average molecular weight of the styrene-(meth)acrylic acid copolymer is, for example, 300000 or less, preferably 200000 or less. It should be noted that the weight-average molecular weight is determined using gel permeation chromatography as a standard polystyrene molecular weight conversion.

[0140] In water-based coating agents, the proportion of other resins is appropriately set according to the purpose and application. For example, relative to 100 parts by weight of polyester resin, the content of other resins (preferably styrene-(meth)acrylic acid copolymer) is, for example, 0 parts by weight or more, preferably 30 parts by weight or more, and more preferably 50 parts by weight or more. Furthermore, relative to 100 parts by weight of polyester resin, the content of other resins (preferably styrene-(meth)acrylic acid copolymer) is, for example, 1000 parts by weight or less, preferably 500 parts by weight or less.

[0141] In addition, water-based coating agents may contain wax. Water-based coating agents preferably contain wax.

[0142] Examples of waxes include fatty acid amide waxes, carnauba wax, rice wax, polyolefin waxes, paraffin wax, Fischer-Tropsch wax, beeswax, microcrystalline wax, oxidized polyethylene wax, and amide waxes. They can be used alone or in combination of two or more.

[0143] As waxes, preferred examples include fatty acid amide waxes, carnauba waxes, polyolefin waxes, paraffin waxes, and microcrystalline waxes, with more preferred examples including carnauba waxes, polyolefin waxes, and paraffin waxes.

[0144] More specifically, examples of fatty acid amide waxes include nonanoic acid amide, decanoic acid amide, undecanoic acid amide, lauryl acid amide, tridecanoic acid amide, tetradecanoic acid amide, pentadecanoic acid amide, hexadecanoic acid amide, heptadecanoic acid amide, stearic acid amide, nonadecanoic acid amide, eicosanoic acid amide, benzyl acid amide, tetracosanoic acid amide, oleic acid amide, cetyl acid amide, linoleic acid amide, linolenic acid amide, and mixtures thereof. Furthermore, examples of fatty acid amide waxes include fatty acid amides from animal and vegetable oils. They can be used alone or in combination of two or more.

[0145] As for carnauba wax, more specifically, examples include MICROKLEAR 418 (manufactured by Micro Powders, Inc.) and Refined Carnauba Wax No. 1 Powder (Nippon Wax Co., Ltd.). They can be used alone or in combination of two or more.

[0146] As olefin waxes, more specifically, examples include polyethylene wax, polypropylene wax, MPP-635VF (Micro Powders, Inc.), and MP-620VF XF (Micro Powders, Inc.). They can be used alone or in combination of two or more.

[0147] As paraffin waxes, more specifically, examples include MP-28C, MP-22XF, and MP-28C (all from MicroPowders, Inc.). They can be used alone or in combination of two or more.

[0148] From the perspective of oil resistance and heat resistance, the melting point of wax is, for example, above 60°C or below 130°C.

[0149] In water-based coating agents, the proportion of wax is appropriately set according to the purpose and application. For example, relative to 100 parts by weight of polyester resin, the wax content is, for example, 0 parts by weight or more, preferably 1 part by weight or more, and more preferably 3 parts by weight or more. Furthermore, relative to 100 parts by weight of polyester resin, the wax content is, for example, 50 parts by weight or less, preferably 30 parts by weight or less.

[0150] From the viewpoint of oil resistance, water-based coatings preferably contain polyester resin components and other resins (preferably styrene-(meth)acrylic acid copolymer) and / or waxes.

[0151] From the viewpoint of oil resistance, water-based coatings are more preferably composed of polyester resin components, other resins (preferably styrene-(meth)acrylic acid copolymer), and waxes.

[0152] For example, when the water-based coating agent contains a polyester resin component and a styrene-(meth)acrylic acid copolymer but is wax-free, the polyester resin component is, for example, 10% by mass or more, preferably 20% by mass or more, relative to the total amount of the polyester resin component and the styrene-(meth)acrylic acid copolymer. Furthermore, the polyester resin component is, for example, 80% by mass or less, preferably 50% by mass or less, relative to the total amount of the polyester resin component and the styrene-(meth)acrylic acid copolymer. Furthermore, the styrene-(meth)acrylic acid copolymer is, for example, 20% by mass or more, preferably 50% by mass or more, relative to the total amount of the polyester resin component and the styrene-(meth)acrylic acid copolymer. Furthermore, the styrene-(meth)acrylic acid copolymer is, for example, 90% by mass or less, preferably 80% by mass or less, relative to the total amount of the polyester resin component and the styrene-(meth)acrylic acid copolymer.

[0153] Furthermore, when the water-based coating agent contains polyester resin and wax but does not contain styrene-(meth)acrylic acid copolymer, the polyester resin content is, for example, 10% by mass or more, preferably 20% by mass or more, relative to the total amount of polyester resin and wax. Furthermore, the polyester resin content is, for example, 80% by mass or less, preferably 50% by mass or less, relative to the total amount of polyester resin and wax. Furthermore, the wax content is, for example, 20% by mass or more, preferably 50% by mass or more, relative to the total amount of polyester resin and wax. Furthermore, the wax content is, for example, 90% by mass or less, preferably 80% by mass or less, relative to the total amount of polyester resin and wax.

[0154] Furthermore, when the water-based coating agent contains polyester resin, styrene-(meth)acrylic acid copolymer, and wax, the polyester resin content, relative to the total amount of the polyester resin, styrene-(meth)acrylic acid copolymer, and wax, is, for example, 10% by mass or more, preferably 20% by mass or more. Furthermore, relative to the total amount of the polyester resin, styrene-(meth)acrylic acid copolymer, and wax, the polyester resin content is, for example, 90% by mass or less, preferably 80% by mass or less. Furthermore, relative to the total amount of the polyester resin, styrene-(meth)acrylic acid copolymer, and wax, the styrene-(meth)acrylic acid copolymer is, for example, 10% by mass or more, preferably 20% by mass or more. Furthermore, relative to the total amount of the polyester resin, styrene-(meth)acrylic acid copolymer, and wax, the styrene-(meth)acrylic acid copolymer is, for example, 90% by mass or less, preferably 80% by mass or less. Furthermore, relative to the total amount of the polyester resin, styrene-(meth)acrylic acid copolymer, and wax, the wax content is, for example, 1% by mass or more, preferably 5% by mass or more. Furthermore, relative to the total amount of the polyester resin, styrene-(meth)acrylic acid copolymer, and wax, the wax content is, for example, 20% by mass or less, preferably 10% by mass or less.

[0155] In addition, water-based coating agents may contain dispersants. Dispersants are additives used to stably disperse rosin-modified polyester resins in aqueous media. 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 glycol dispersants, and polyaminoamide dispersants. They can be used alone or in combination of two or more. There are no particular limitations on the amount of dispersant used; it should be appropriately determined according to the purpose and application.

[0156] Furthermore, the water-based coating agent may contain a neutralizing agent. That is, the neutralizing agent can be used to neutralize the carboxyl groups of the aforementioned polyester resin components. Neutralization improves the stability of the rosin-modified polyester resin in the water-based medium.

[0157] Examples of neutralizing agents include, for example, basic compounds. Examples of basic compounds include, for example, ammonia, triethylamine, N,N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine, isobutylamine, dipropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, tert-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, pyrrole, and pyridine. They can be used alone or in combination of two or more.

[0158] There are no particular limitations on the amount of neutralizing agent used, and it can be appropriately set according to the purpose and application. More specifically, from the viewpoint of the stability of the waterborne coating agent, the amount of neutralizing agent used 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 waterborne coating agent, the amount of neutralizing agent used is, for example, 30 equivalents or less, preferably 10 equivalents or less, relative to the carboxyl groups in the rosin-modified polyester resin.

[0159] Furthermore, water-based coatings may contain additives in appropriate proportions. Examples of additives include, for instance, fillers, thickeners, foaming agents, antioxidants, light stabilizers, heat stabilizers, and flame retardants. They may be used alone or in combination of two or more.

[0160] Furthermore, in the aforementioned water-based coating agent, the acid value of the polyester resin component containing rosin-modified polyester resin is within a predetermined range, and the hydroxyl value of the polyester resin component containing rosin-modified polyester resin is within a predetermined range. Therefore, the aforementioned water-based coating agent can form a coating film with excellent oil resistance.

[0161] More specifically, the aforementioned polyester resin components have a high acid value to improve oil resistance. However, when the polyester resin components are obtained through a general esterification reaction using only a large amount of α,β-unsaturated dicarboxylic acid to increase the acid value, gelation is prone to occur during the esterification reaction.

[0162] In the above method, the esterification reaction is adjusted to a lower temperature. Therefore, gelation during the esterification reaction is suppressed. Specifically, by adjusting the reaction temperature of the esterification reaction to below the aforementioned upper limit, the reaction of tertiary carboxyl groups from (A) rosin and the reaction of carboxyl groups from (B) α,β-unsaturated dicarboxylic acids can be suppressed. Therefore, according to the above method, gelation can be suppressed and a polyester resin component with a high acid value can be obtained. Therefore, an aqueous coating agent containing the above-mentioned polyester resin component can form a coating film with excellent oil resistance.

[0163] This invention includes articles comprising a coating film containing an aqueous coating agent. More specifically, the articles comprise a substrate and a dried coating film of an aqueous coating agent formed on the substrate.

[0164] Examples of substrates include plastic films, vapor-deposited films, metal foils, paper, fabrics, and non-woven fabrics. Plastic films and paper are preferred substrates.

[0165] The aforementioned water-based coating agent is applied to a substrate using known methods. Examples of such coating methods include spraying, curtain coating, flow coating, roller coating, brush coating, dip coating, and flexographic printing.

[0166] The water-based coating agent is then dried using a known method. The drying conditions can be natural drying at room temperature or heating drying. Heating drying is preferred. The heating drying temperature is, for example, 40°C or higher, preferably 50°C or higher. Furthermore, the drying temperature is, for example, 250°C or lower, preferably 230°C or lower. Furthermore, the drying time is, for example, 1 second or higher, preferably 5 seconds or higher. Furthermore, the drying time is, for example, 600 seconds or lower, preferably 500 seconds or lower.

[0167] This yields a dried coating film of the water-based coating agent, resulting in an article comprising a substrate and the dried coating film. Such an article exhibits excellent oil resistance because it contains the coating film of the aforementioned water-based coating agent.

[0168] Example

[0169] Next, the present invention will be described based on embodiments and comparative examples, but the present invention is not limited to the embodiments described below. It should be noted that, unless otherwise specified, "parts" and "%" are both mass bases. In addition, the specific values ​​of the proportions (including proportions), physical property values, parameters, etc. used in the following description can be replaced with the corresponding upper limit values ​​(values ​​defined in the form of "less than" or "less than") or lower limit values ​​(values ​​defined in the form of "more than" or "exceeding") of the proportions (including proportions), physical property values, parameters, etc., described in the "Specific Embodiments" above.

[0170] <Determination Method>

[0171] (1) Acid value

[0172] The acid value of polyester resin components was determined based on JIS K 5601-2-1 (1999).

[0173] (2) Hydroxyl value

[0174] The hydroxyl value of polyester resin components was determined based on JIS K 0070 (1992).

[0175] (3) The proportion of components with a molecular weight of less than 500

[0176] The proportion of components with a molecular weight below 500 was determined by the following method: The polyester resin component was dissolved in tetrahydrofuran to obtain a sample of 1.0 g / L. Next, the molecular weight distribution of the sample was obtained using gel permeation chromatography (GPC) equipped with a refractive index detector (RID).

[0177] Then, based on the obtained chromatogram (curve), using standard polystyrene as the standard curve, the content ratio of components with a molecular weight below 500 is calculated. The measuring apparatus and measuring conditions are shown below.

[0178] Data processing device: Product number Agilent 1260 Infinity II (manufactured by Agilent Technologies)

[0179] Differential refractive index detector: The RI detector (G7162A) built into the Agilent 1260 Infinity II product.

[0180] Column: Product No. PL gelmixed-B7.5×300mm (manufactured by Agilent Technologies)

[0181] 3

[0182] Mobile phase: Tetrahydrofuran

[0183] Column flow rate: 1.0 ml / min

[0184] Sample concentration: 2.0 g / L

[0185] Injection volume: 10μL

[0186] Measurement temperature: 30℃

[0187] Molecular weight designation: Standard polystyrene (using Agilent's EasiCal Polystyrene Standards PS-1)

[0188] Synthesis Example 1 (Resin 1)

[0189] Nitrogen gas was purged into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer. Simultaneously, 39.6 parts of rosin were added, and the temperature was raised to 210°C. Next, 12.9 parts of fumaric acid were added to the flask, and the mixture was stirred at 210°C for approximately 30 minutes. This caused the rosin to undergo a Diels-Alder reaction with the fumaric acid, yielding the first product (Step 1).

[0190] Next, 24.3 parts of adipic acid and 23.2 parts of glycerol were added to the flask, and the contents were subjected to esterification at 190°C for approximately 8 hours. This yielded the second product (step 2).

[0191] The second product was used as a component of the polyester resin containing rosin-modified polyester resin (hereinafter, 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 proportion of components with a molecular weight of 500 or less in Resin 1 was 18% by mass.

[0192] Synthetic Examples 9–10, 14, 17 and 19 (Resins 9–10, 14, 17 and 19)

[0193] The formulations were changed to those listed in Tables 1 to 4, and resins 9-10, 14, 17, and 19 were obtained by the same method as in Synthesis Example 1. It should be noted that the reaction conditions were set as described in Tables 1 to 4.

[0194] Synthesis Example 2 (Resin 2)

[0195] Nitrogen gas was blown into a four-necked flask equipped with a stirrer, a reflux cooler with a water separator, and a thermometer. Simultaneously, 17.8 parts of linseed oil (iodine value 180 mg / 100 mg), 18.1 parts of glycerol, 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. This process modifies glycerol with linseed oil, yielding linseed oil-modified glycerol (modification step).

[0196] On the other hand, 37.5 parts of rosin were added to a four-necked 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 were added to the flask, and the mixture was stirred at 210°C for about 30 minutes. This caused the rosin to undergo a Diels-Alder reaction with the fumaric acid, yielding the first product (step 1).

[0197] Next, 35.9 parts of flaxseed oil-modified glycerol and 13.1 parts of adipic acid were added to the flask, and the contents were subjected to esterification at 190°C for approximately 8 hours. This yielded the second product (step 2).

[0198] The second product is used as a component of the polyester resin containing rosin-modified polyester resin (hereinafter, Resin 2). The acid value of Resin 2 is 122 mg KOH / g. The hydroxyl value of Resin 2 is 130 mg KOH / g. The proportion of components with a molecular weight of 500 or less in Resin 2 is 15% by mass.

[0199] Synthetic Examples 3-8 and 15-16 (Resins 3-8 and 15-16)

[0200] The formulations were changed to those listed in Tables 1 to 4, and resins 3 to 8 and 15 to 16 were obtained using the same method as in Synthesis Example 2. It should be noted that the reaction conditions were set to those listed in Tables 1 to 4.

[0201] Synthesis Example 11 (Resin 11)

[0202] Nitrogen gas was purged into a four-necked flask equipped with a stirrer, a reflux condenser with a water separator, and a thermometer. Simultaneously, 37.5 parts of rosin were added, and the temperature was raised to 210°C. Next, 12.2 parts of fumaric acid were added to the flask, and the mixture was stirred at 210°C for approximately 30 minutes. This caused the rosin to undergo a Diels-Alder reaction with the fumaric acid, yielding the first product (Step 1).

[0203] Next, 12.1 parts of adipic acid, 19.7 parts of glycerol, and 18.5 parts of tall oil fatty acid (iodine value 140 mg / 100 mg) were added to the flask, and the contents were subjected to esterification at 190°C for approximately 8 hours. This yielded the second product (step 2).

[0204] The second product is used as a component of the polyester resin containing rosin-modified polyester resin (hereinafter, resin 11). The acid value of resin 11 is 120 mg KOH / g. The hydroxyl value of resin 11 is 140 mg KOH / g. The proportion of components with a molecular weight of 500 or less in resin 11 is 21% by mass.

[0205] Synthetic Examples 12-13 and 18 (Resins 12-13 and 18)

[0206] Resins 12-13 and 18 were obtained by changing the formulations to those listed in Tables 1-4, except that the same method was used as in Synthesis Example 11. It should be noted that the reaction conditions were set to those listed in Tables 1-4.

[0207] Examples 1-16 and Comparative Examples 1-3

[0208] Aqueous coating agents 1-16 were obtained according to the formulations recorded in Tables 1-4. Specifically, 30 parts resin, 10 parts 25% ammonia solution, and 60 parts distilled water were added to an Erlenmeyer flask equipped with a reflux flask, and the mixture was stirred at 70°C for approximately 2 hours. This neutralized and dissolved the resin, yielding an aqueous solution.

[0209] Furthermore, using a 6μm rod coater, 250g / m² of board paper was coated with various water-based coating agents. Then, the water-based coating agents were dried to obtain a coating film. Furthermore, an article (coated paper) having the coating film of the water-based coating agent was obtained.

[0210] <Oil Resistance Evaluation>

[0211] The oil resistance of a surface material is evaluated using the TAPPI T559cm-02 test, a standard kit-type test, according to the Technical Association of Pulp and Paper Industries (TAPPI). The evaluation is graded on a scale of 1 to 10. A grade of 3 or higher indicates excellent oil resistance.

[0212] <Styrene-(meth)acrylic acid copolymer>

[0213] Manufacturing Example 1

[0214] A monomer composition was obtained by mixing 104 parts styrene, 17 parts methacrylic acid, 34 parts n-butyl methacrylate, 138 parts 2-ethylhexyl acrylate, 52 parts methyl methacrylate, and 2 parts n-dodecyl mercaptan as a chain transfer agent. In addition, 4 parts potassium persulfate were dissolved in 256 parts water to prepare an aqueous polymerization initiator solution.

[0215] Then, 360 parts of water and 12 parts of sodium dodecylbenzenesulfonate (NEOPELEX G-25: manufactured by Kao Corporation) as an emulsifier were added to a four-necked flask equipped with a stirrer, thermometer, reflux cooler, water separator and nitrogen inlet tube, and heated and stirred to 88°C.

[0216] In the aforementioned flask, the monomer composition and the polymerization initiator aqueous solution were continuously injected over 6 hours, while the temperature was maintained below 90°C to allow polymerization to proceed for 30 minutes to mature. Next, the temperature was raised to 95°C to complete the polymerization, and then cooled to 40°C.

[0217] Then, 1 part of 28% ammonia was added to the above flask for neutralization, resulting in an aqueous solution of alkali metal salt of styrene-(meth)acrylic acid copolymer with a solid content of 35.5% by mass and a viscosity of 21 mPa·s (25°C).

[0218] Manufacturing Example 2

[0219] 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, 52 parts of methyl methacrylate, and 2 parts of n-dodecyl mercaptan as a chain transfer agent.

[0220] In addition to the above, an aqueous solution of alkali metal salt of styrene-(meth)acrylic acid copolymer with a solid content of 35.2% by mass and a viscosity of 25 mPa·s (25°C) was obtained by the same method as in manufacturing example 1.

[0221] <Wax>

[0222] Preparation Example 1

[0223] Prepared for commercial sale: a wax emulsion (product name Dijet H, manufactured by Koyo Chemical Industry Co., Ltd.).

[0224] Examples 17-22

[0225] According to the formulations described in Table 5, water-based coating agents 17 to 22 were obtained. That is, the polyester resin component was mixed with styrene-(meth)acrylic acid copolymer and / or wax in such a manner that the solid components were formed in the parts by mass of the solid components described in Table 5, to obtain a resin mixture.

[0226] Next, in an Erlenmeyer flask equipped with a reflux duct, 30 parts of the resin mixture, 10 parts of a 25% ammonia solution, and 60 parts of distilled water were added, and the mixture was stirred at 70°C for approximately 2 hours. This neutralizes and dissolves the resin mixture, yielding an aqueous solution. It should be noted that the concentration of solid components, pH, and viscosity are shown in Table 5. This yields aqueous coating agents 17–22.

[0227] Furthermore, each water-based coating agent was adjusted to a temperature of 25°C and coated onto 250 g / m² sheet paper using a bar coater (number 22). The water-based coating agent was then dried to obtain a coating film. An article (coated paper) with the water-based coating film was obtained. It should be noted that the amount of solid component (resin component) adhered was 7–8 g / m². 2 .

[0228] The coated paper was conditioned for 12 hours in a constant temperature and humidity environment (22℃, 50% relative humidity). Then, the coated paper was used for oil resistance evaluation.

[0229] <Oil Resistance Evaluation>

[0230] The oil resistance of a surface material is evaluated using the TAPPI T559cm-02 test, a standard kit-type test, according to the Technical Association of Pulp and Paper Industries (TAPPI). The evaluation is graded on a scale of 1 to 12. A grade of 3 or higher indicates excellent oil resistance.

[0231] [Table 1]

[0232]

[0233] [Table 2]

[0234]

[0235] [Table 3]

[0236]

[0237] [Table 4]

[0238]

[0239] [Table 5]

[0240]

[0241] It should be noted that the above-described inventions are provided as illustrative embodiments of the present invention, and are merely examples and should not be construed as limiting. Modifications of the invention that are obvious to those skilled in the art are included in the claims.

[0242] Industry availability

[0243] The water-based coating agent, articles, and method for manufacturing rosin-modified polyester resin of the present invention are suitable for use in the field of coating various substrates.

Claims

1. A water-based coating agent comprising a water-based medium and a polyester resin component, The polyester resin component contains rosin-modified polyester resin, which is a reaction product containing (A) rosin, (B) α,β-unsaturated dicarboxylic acid, (C) polyol and (D) oils and / or fatty acids. The acid value of the polyester resin component is above 86 mg KOH / g and below 170 mg KOH / g. The hydroxyl value of the polyester resin component is above 110 mg KOH / g and below 170 mg KOH / g. Of the raw material components, relative to 100 moles of (A) rosin, the content of (B) α,β-unsaturated dicarboxylic acid is more than 70 moles and less than 150 moles. The proportion of (D) oil and / or fatty acids is more than 10% by mass and less than 30% by mass relative to the total amount of the raw material components.

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

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

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

5. An article comprising a coating film of the aqueous coating agent of claim 1.

6. A method for manufacturing a rosin-modified polyester resin, wherein the rosin-modified polyester resin is a reaction product containing (A) rosin, (B) α,β-unsaturated dicarboxylic acid, (C) polyol, and (D) oil and / or fatty acid, wherein, relative to 100 moles of the (A) rosin, the content of (B) α,β-unsaturated dicarboxylic acid is 70 moles to 150 moles, and, The content of (D) oils and / or fatty acids is between 10% and 30% by mass relative to the total amount of the raw material components. The method for manufacturing the rosin-modified polyester resin comprises a first step of reacting (A) rosin with (B) α,β-unsaturated dicarboxylic acid to obtain a first product, and a second step after the first step of reacting the first product with (C) a polyol to obtain a second product, wherein the acid value of the second product is 86 mg KOH / g or more and 170 mg KOH / g or less, and the hydroxyl value of the second product is 110 mg KOH / g or more and 170 mg KOH / g or less. In the second step, the (D) oil and / or fatty acid react with the first product and the (C) polyol, and / or the (D) oil and / or fatty acid modify the (C) polyol before the second step. The reaction temperature of the second process is below 230°C.

7. The method for manufacturing rosin-modified polyester resin according to claim 6, comprising a modification step prior to the second step of modifying the (C) polyol with (D) oil and / or fatty acids. The reaction temperature of the modification process is above 230℃ and below 300℃.

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