Metal coating composition with improved oil resistance and adhesion, method for producing same, and metal article coated with said composition

Abstract

The present invention relates to a metal coating composition having improved oil resistance and adhesion, a method for producing the same, and a metal article coated with the composition. More specifically, the present invention relates to a composition which contains a (meth)acrylic-modified polyurethane containing polymerization units derived from an anhydrosugar alcohol-alkylene oxide adduct, a (meth)acrylic monomer, and an epoxy resin, and which can provide a coating which has excellent adhesion to metal and at the same time has improved oil resistance, a method for producing the same, and a metal article coated with the composition.

Description

[Technical field]

[0001] The present invention relates to a metal coating composition having improved oil resistance and adhesion, a method for producing the same, and a metal article coated with the composition. More specifically, the present invention relates to a composition which contains a (meth)acrylic-modified polyurethane containing polymerization units derived from an anhydrosugar alcohol-alkylene oxide adduct, a (meth)acrylic monomer, and an epoxy resin, and which can provide a coating which has excellent adhesion to metal and at the same time has improved oil resistance, a method for producing the same, and a metal article coated with the composition. [Background technology]

[0002] Polyols and isocyanates, which are essential components of polyurethane, are usually produced from petroleum-derived raw materials. However, due to various reasons such as the accelerating depletion of petroleum resources, the demand for reducing greenhouse gases due to climate change, rising raw material prices, and the growing need for recyclable raw materials, there is a demand for a method to replace part or all of the polyols and isocyanates produced from petroleum-based raw materials with environmentally friendly components.

[0003] Polyols can be produced from recyclable biomass such as natural vegetable oils, cellulose, and lignin, and bio-polyols derived from natural vegetable oils have already been produced on a commercial scale. The physical properties of the produced bio-polyols vary depending on the type of biomass used in their production. In general, castor oil, palm oil, etc. are used to produce polyols for flexible and rigid polyurethanes and synthesis, and soybean oil is used to produce polyols for flexible polyurethanes. However, the bio-polyols derived from biomass currently produced have the disadvantage of being highly viscous.

[0004] Natural vegetable oil-based isocyanates are essentially aliphatic and have the disadvantage of being less reactive than petroleum-based aromatic diisocyanates, so there has been little research into the use of biomass to produce diisocyanates.

[0005] Hydrogenated sugars (also called "sugar alcohols") are compounds obtained by adding hydrogen to the reducing end group of sugars, generally HOCH2 (CHOH). n It has the formula CH2OH (where n is an integer of 2 to 5). Depending on the number of carbon atoms, they are classified into tetritols, pentitols, hexitols, and heptitols (having 4, 5, 6, and 7 carbon atoms, respectively). Among them, hexitols having 6 carbon atoms include sorbitol, mannitol, iditol, and galactitol, and in particular, sorbitol and mannitol are very useful substances.

[0006] Anhydrous sugar alcohols are substances formed by removing one or more water molecules from the inside of hydrogenated sugar. When one water molecule is removed, a tetraol form having four hydroxyl groups in the molecule is obtained, and when two water molecules are removed, a diol form having two hydroxyl groups in the molecule is obtained, and can be produced using hexitol derived from starch (e.g., Patent Documents 1 and 2). Anhydrous sugar alcohols are environmentally friendly substances derived from renewable natural resources, and have long been attracting attention, and research into their production methods has been ongoing. Among such anhydrous sugar alcohols, isosorbide produced from sorbitol currently has the widest range of industrial applications.

[0007] Anhydrous sugar alcohols can be used in various fields, such as medicines for the treatment of heart and vascular diseases, patch adhesives, oral cleansers, solvents for compositions in the cosmetic industry, and emulsifiers in the food industry. They can also increase the glass transition temperature of polymeric substances such as polyester, PET, polycarbonate, polyurethane, and epoxy resins, and improve the strength of such substances. Furthermore, anhydrous sugar alcohols are environmentally friendly materials derived from natural products, and are therefore very useful in the plastics industry, such as bioplastics. In addition, anhydrous sugar alcohols are known to be usable as adhesives, environmentally friendly plasticizers, biodegradable polymers, and environmentally friendly solvents for water-soluble lacquers.

[0008] Thus, anhydrosugar alcohols have attracted much attention due to their wide range of applications, and the level of industrial practical application has also progressed.

[0009] Meanwhile, Patent Document 3 discloses the preparation of a conductive adhesive between metals in the presence of acrylic-modified polyurethane, other acrylic monomers, and a thermal polymerization initiator. However, the adhesive composition prepared in this manner has insufficient oil resistance, and the adhesiveness needs to be further improved. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent No. 10-1079518 [Patent Document 2] Korea Patent No. 10-2012-0066904 [Patent Document 3] Korea Patent No. 10-2017-0125328 Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to provide a metal coating composition that utilizes a (meth)acrylic-modified polyurethane containing polymerization units derived from an anhydrosugar alcohol derivative, thereby providing a coating that has excellent adhesion to metals and improved oil resistance while also having good environmental friendliness (environmentally friendly), a method for producing the same, and a metal article coated with the composition. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the present invention provides a metal coating composition comprising, relative to 100 parts by weight of a total amount of the composition, 5.1 to 64.9 parts by weight of (meth)acrylic-modified polyurethane; 7.1 to 74.9 parts by weight of (meth)acrylic monomer; 2.1 to 44.9 parts by weight of epoxy resin; 0.051 to 2.49 parts by weight of epoxy curing accelerator; and 0.00051 to 2.49 parts by weight of thermal polymerization initiator, wherein the (meth)acrylic-modified polyurethane comprises i) polymerization units derived from anhydrosugar alcohol-alkylene oxide adduct; ii) polymerization units derived from polyisocyanate; and iii) polymerization units derived from hydroxyalkyl (meth)acrylate.

[0013] According to another aspect of the present invention, there is provided a method for producing a metal coating composition, comprising a step of mixing, relative to 100 parts by weight of a total mixture, 5.1 to 64.9 parts by weight of (meth)acrylic-modified polyurethane; 7.1 to 74.9 parts by weight of (meth)acrylic monomer; 2.1 to 44.9 parts by weight of epoxy resin; 0.051 to 2.49 parts by weight of epoxy curing accelerator; and 0.00051 to 2.49 parts by weight of thermal polymerization initiator, wherein the (meth)acrylic-modified polyurethane comprises i) polymerization units derived from anhydrosugar alcohol-alkylene oxide adduct; ii) polymerization units derived from polyisocyanate; and iii) polymerization units derived from hydroxyalkyl (meth)acrylate.

[0014] According to yet another aspect of the present invention, there is provided a coated metal article comprising: a metal article; and a coating layer of the metal coating composition of the present invention on a surface of the metal article. Effect of the Invention

[0015] The metal coating composition according to the present invention has excellent adhesion to metals and also has excellent oil resistance after coating. Since the curing speed is fast, it can quickly provide a coating having excellent oil resistance and adhesion on the metal surface. In addition, since anhydrous sugar alcohol derived from natural resources is used, it is also environmentally friendly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will be described in detail below.

[0017] The metal coating composition of the present invention comprises: a (meth)acrylic modified polyurethane; a (meth)acrylic monomer; an epoxy resin; an epoxy curing accelerator; and a thermal polymerization initiator.

[0018] [(Meth)acrylic modified polyurethane] The (meth)acrylic-modified polyurethane contained in the metal coating composition of the present invention contains i) polymerized units derived from an anhydrosugar alcohol-alkylene oxide adduct; ii) polymerized units derived from a polyisocyanate; and iii) polymerized units derived from a hydroxyalkyl (meth)acrylate.

[0019] The anhydrosugar alcohol-alkylene oxide adduct (or "anhydrosugar alcohol-alkylene glycol") is an adduct obtained by reacting the hydroxyl groups at both ends or one end (preferably both ends) of an anhydrosugar alcohol with an alkylene oxide, and refers to a compound in which the hydrogen atoms of the hydroxyl groups at both ends or one end (preferably both ends) of the anhydrosugar alcohol are replaced with ring-opened hydroxyalkyl groups of the alkylene oxide. In one embodiment, the alkylene oxide may be a linear alkylene oxide having 2 to 8 carbon atoms or a branched alkylene oxide having 3 to 8 carbon atoms, and more specifically, may be ethylene oxide, propylene oxide, or a combination thereof.

[0020] The anhydrous sugar alcohol can be produced by the dehydration reaction of hydrogenated sugar derived from natural products. Hydrogenated sugar (also called "sugar alcohol") means a compound obtained by adding hydrogen to the reducing end group of sugar, and is generally represented by HOCH2 (CHOH). nThey have the formula CH2OH (where n is an integer of 2 to 5) and are classified into tetritols, pentitols, hexitols and heptitols (having 4, 5, 6 and 7 carbon atoms, respectively) according to the number of carbon atoms. Among them, hexitols with 6 carbon atoms include sorbitol, mannitol, iditol and galactitol, and sorbitol and mannitol are very useful substances.

[0021] The anhydrous sugar alcohol may be a monoanhydrous sugar alcohol, a dianhydrous sugar alcohol, or a mixture thereof, and is not particularly limited, but a dianhydrous sugar alcohol can be used.

[0022] The monoanhydrosugar alcohol is an anhydrosugar alcohol formed by removing one water molecule from the inside of a hydrogenated sugar, and is in the form of a tetraol having four hydroxyl groups in the molecule. In the present invention, the type of the monoanhydrosugar alcohol is not particularly limited, but may be preferably a monoanhydrosugar hexitol, more specifically, 1,4-anhydrohexitol, 3,6-anhydrohexitol, 2,5-anhydrohexitol, 1,5-anhydrohexitol, 2,6-anhydrohexitol, or a mixture of two or more thereof.

[0023] Dianhydrosugar alcohols are anhydrous sugar alcohols formed by removing two water molecules from inside a hydrogenated sugar, and are in the form of a diol with two hydroxyl groups in the molecule, and can be produced using hexitol derived from starch. Dianhydrosugar alcohols are environmentally friendly substances obtained from renewable natural resources, and have long attracted much attention, and research into their production methods has been ongoing. Among these dianhydrosugar alcohols, isosorbide produced from sorbitol currently has the widest range of industrial applications.

[0024] In the present invention, the type of the dianhydrosugar alcohol is not particularly limited, but may be preferably a dianhydrosugar hexitol, more specifically, 1,4:3,6-dianhydrohexitol. The 1,4:3,6-dianhydrohexitol may be isosorbide, isomannide, isoidide, or a mixture of two or more thereof.

[0025] In one embodiment, the anhydrosugar alcohol-alkylene oxide adduct has the following formula (1): [ka] (In the formula, R 1 and R 2 each independently represents a linear alkylene group having 2 to 8 carbon atoms or a branched alkylene group having 3 to 8 carbon atoms, m and n each independently represent an integer of 0 to 15, and m+n represents an integer of 1 to 30.) or a mixture of two or more of these.

[0026] More preferably, in the formula (1), R 1 and R 2 each independently represents an ethylene group, a propylene group, or an isopropylene group, preferably R 1 and R 2 are the same, m and n each independently represent an integer of 0 to 14; Here, m+n is an integer of 1 or more, 2 or more, or 3 or more, or an integer of 25 or less, 20 or less, 15 or less, or 12 or less, for example, an integer of 1 to 25, preferably an integer of 2 to 20, and more preferably an integer of 3 to 15.

[0027] In one embodiment, the anhydrosugar alcohol-alkylene oxide adduct is represented by the following formula (1-1): [ka] (wherein a and b each independently represent an integer of 0 to 15, and a+b represents an integer of 1 to 30), [ka] (wherein c and d each independently represent an integer of 0 to 15, and c+d represents an integer of 1 to 30), or a mixture thereof.

[0028] More preferably, in the formula (1-1), a and b each independently represent an integer of 0 to 14; Here, a+b is an integer of 1 or more, 2 or more, or 3 or more, or an integer of 25 or less, 20 or less, 15 or less, or 12 or less, for example, an integer of 1 to 25, preferably an integer of 2 to 20, and more preferably an integer of 3 to 15.

[0029] More preferably, in the formula (1-2), c and d each independently represent an integer of 0 to 14; Here, c+d is an integer of 1 or more, 2 or more, or 3 or more, or an integer of 25 or less, 20 or less, 15 or less, or 12 or less, for example, an integer of 1 to 25, preferably an integer of 2 to 20, and more preferably an integer of 3 to 15.

[0030] In one embodiment, the anhydrosugar alcohol-alkylene oxide adduct may be produced by a production method including: (1) a step of treating an anhydrosugar alcohol with an acid component; and (2) a step of subjecting the acid component anhydrosugar alcohol obtained in step (1) to an addition reaction with an alkylene oxide.

[0031] More specifically, the anhydrosugar alcohol-alkylene oxide adduct may be produced by a production method including: (1) a step of treating an anhydrosugar alcohol with an acid component; (2) a step of subjecting the acid component anhydrosugar alcohol obtained in the step (1) to an addition reaction with an alkylene oxide; and (3) a step of subjecting the product obtained in the step (2) to an addition reaction with an alkylene oxide in the presence of a base catalyst.

[0032] The acid component is not particularly limited and may be selected from the group consisting of phosphoric acid, sulfuric acid, acetic acid, formic acid, heteropolyacid, or a mixture thereof. In one embodiment, the heteropolyacid may be phosphotungstic acid, phosphomolybdic acid, silicotungstic acid, silicomolybdic acid, or the like, and another useful acid component may be a commercially available acid component such as Amberlyst 15 (manufactured by Dow Chemical).

[0033] In one embodiment, the acid treatment can be carried out using 0.1 to 10 mol, preferably 0.1 to 8 mol, and more preferably 0.1 to 5 mol of an acid component per 1 mol of anhydrosugar alcohol, at elevated temperature (e.g., 80°C to 200°C or 90°C to 180°C) in a nitrogen atmosphere, and pressure reduction can be performed under vacuum to remove moisture from within the reactor, but is not limited thereto.

[0034] In the acid treatment, the acid component is used to promote ring-opening of alkylene oxide in the addition reaction of alkylene oxide described below.

[0035] Generally, the reaction of adding alkylene oxide to alcohol proceeds under a base catalyst, but in the case of anhydrosugar alcohol, due to the structural characteristics, the rate of addition of alkylene oxide competes with the rate of ring opening and decomposition of the ring structure of anhydrosugar alcohol by base catalyst. Therefore, not only anhydrosugar alcohol but also decomposition products of anhydrosugar alcohol react with alkylene oxide, and the reaction product of the decomposition product of anhydrosugar alcohol decomposed by base catalyst and alkylene oxide may act as a factor of reducing the quality and storage stability of the product. In contrast, if anhydrosugar alcohol is first treated with an acid component and then subjected to an addition reaction with alkylene oxide, the acid component promotes ring opening of alkylene oxide without generating decomposition products of anhydrosugar alcohol by base catalyst, and anhydrosugar alcohol-alkylene oxide adduct can be easily produced by the addition reaction of anhydrosugar alcohol and alkylene oxide. Therefore, the addition reaction of an acid-treated anhydrosugar alcohol with alkylene oxide can solve the conventional problems.

[0036] In one embodiment, the addition reaction of the anhydrosugar alcohol treated with the acid component and the alkylene oxide is carried out at a temperature (e.g., 100°C to 180°C, or 120°C to 160°C) obtained by slowly adding the alkylene oxide to the anhydrosugar alcohol treated with the acid component, for example, 1 hour to 8 hours or 2 hours to 4 hours, but is not limited thereto. The reaction molar ratio of the alkylene oxide to 1 mole of the anhydrosugar alcohol is, for example, 1 mole or more or 2 moles or more of the alkylene oxide, and is 30 moles or less, 20 moles or less, 15 moles or less, or 12 moles or less, for example, 1 to 30 moles, preferably 2 to 20 moles, but is not limited thereto.

[0037] In one embodiment, the further addition reaction between the product obtained by the alkylene oxide addition reaction and additional alkylene oxide is carried out, for example, in a high-pressure reactor capable of being pressurized (for example, pressurized to 3 MPa or more) in the presence of a base catalyst (for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, or an alkaline earth metal hydroxide such as calcium hydroxide) at a high temperature (for example, 100°C to 180°C or 120°C to 160°C, for example, 1 hour to 8 hours or 2 hours to 4 hours, but is not limited thereto. The reaction molar ratio of alkylene oxide to 1 mole of anhydrous sugar alcohol is, for example, 1 mole or more, 2 moles or more, or 3 moles or more, and may be, for example, 1 to 30 moles, preferably 2 to 20 moles, and more preferably 3 to 15 moles, but is not limited thereto. Before the base catalyst is added, the acid component used in the treatment can be removed by filtration.

[0038] The product obtained by the addition reaction of the acid-treated anhydrosugar alcohol and the alkylene oxide (i.e., a compound in which an alkylene oxide is added to an anhydrosugar alcohol) has a very stable structure, so that the ring structure of the anhydrosugar alcohol does not easily open or decompose at high temperatures even in the presence of a base catalyst. Therefore, it is very advantageous for further addition reaction of the alkylene oxide. If an acid catalyst is continued to be used in the further addition reaction of the alkylene oxide, the acid catalyst helps to promote the ring opening of the alkylene oxide, but the reaction rate decreases as the mole number of the alkylene oxide added increases. In other words, the addition rate of the alkylene oxide competes with the ring opening rate of the alkylene oxide itself, and the addition rate of the alkylene oxide at this time slows down, and the self-condensation reaction between the ring-opened alkylene oxides and the production of by-products progress, causing quality deterioration. Therefore, the further addition reaction of the alkylene oxide is carried out under a base catalyst.

[0039] Thereafter, a step of removing metal ions leaching from the used base catalyst may be further carried out, and for this purpose, a metal ion adsorbent such as Ambosol MP20 (magnesium silicate component) may be used.

[0040] In one embodiment, examples of the polyisocyanate include aromatic polyisocyanates such as methylene diphenyl diisocyanate (MDI) (e.g., 2,4- or 4,4'-methylene diphenyl diisocyanate), xylene diisocyanate (XDI), m- or p-tetramethyl xylene diisocyanate (TMXDI), toluene diisocyanate (TDI), di- or tetra-alkyl diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate (TODI), phenylene diisocyanate (e.g., 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate), naphthalene diisocyanate (NDI), or 4,4'-dibenzyl diisocyanate; hydrogenated MDI (H12MDI), 1-methyl diisocyanate (MDI), ... aliphatic polyisocyanates such as 1,12-diisocyanatocyclohexane, 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane, isophorone diisocyanate (IPDI), tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate (HDI) (e.g., 1,6-hexamethylene diisocyanate), dimeric fatty acid diisocyanates, dicyclohexylmethane diisocyanate, cyclohexane diisocyanate (e.g., cyclohexane-1,4-diisocyanate) or ethylene diisocyanate; or combinations thereof.

[0041] In another embodiment, examples of the polyisocyanate include methylene diphenyl diisocyanate (MDI), ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1-12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate ( Examples of the isocyanate include, but are not limited to, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (2,4- / 2,6-isomer ratio=80 / 20), diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, polydiphenylmethane diisocyanate (PMDI), naphthalene-1,5-diisocyanate, or combinations thereof.

[0042] More specifically, the polyisocyanate may be methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), or a combination thereof.

[0043] In one embodiment, examples of the hydroxyalkyl (meth)acrylate may be linear or branched alkyl acrylate having a hydroxy group, linear or branched alkyl methacrylate having a hydroxy group, or a combination thereof, more specifically, linear or branched C1-C8 alkyl acrylate having a hydroxy group, linear or branched C1-C8 alkyl methacrylate having a hydroxy group, or a combination thereof, and more specifically, methyl hydroxyacrylate, hydroxymethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxypropyl methacrylate, hydroxypropyl ... The hydroxypropyl acrylate may be, but is not limited to, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxybutyl methacrylate, hydroxypentyl acrylate, hydroxypentyl methacrylate, 2-hydroxyethylhexyl acrylate, 2-hydroxyethylhexyl methacrylate, 2-hydroxyethyl butyl acrylate, 2-hydroxyethyl butyl methacrylate, hydroxyoctyl acrylate, hydroxyoctyl methacrylate, or a combination thereof, and more specifically, may be, but is not limited to, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, or a combination thereof.

[0044] In one embodiment, the (meth)acrylic modified polyurethane is represented by the following formula (2): [ka] (In the formula, each R1 is independently an alkylene group, specifically, a C2-C8 linear or C3-C8 branched alkylene group, more specifically, a C2-C6 linear or C3-C6 branched alkylene group, R2 is each independently an alkylene group, a cycloalkylene group, or an arylene group, specifically, a C2-C20 linear or C3-C20 branched alkylene group, a C3-C20 cycloalkylene group, or a C6-C20 arylene group; R3 is each independently an alkylene group, specifically a C1-C8 linear or C3-C8 branched alkylene group, more specifically a C2-C6 linear or C3-C6 branched alkylene group; R4 is each independently a hydrogen atom or an alkyl group, specifically, a hydrogen atom or a C1-C4 linear or C3-C4 branched alkyl group; M is a divalent organic group derived from an anhydrosugar alcohol, specifically a divalent organic group derived from isosorbide, isomannide or isoidide, more specifically a divalent organic group represented by the following formula: [ka] is selected from m and n each independently represent an integer of 0 to 15; m+n represents an integer of 1 to 30, more specifically an integer of 1 to 25, even more specifically an integer of 1 to 20, still more specifically an integer of 3 to 15, and even more specifically an integer of 5 to 15.

[0045] More specifically, the (meth)acrylic modified polyurethane is represented by the following formula: [ka] (wherein m, n and m+n are each independently defined as in formula (2) above), but are not limited thereto.

[0046] The (meth)acrylic modified polyurethane can be obtained by reacting an anhydrous sugar alcohol-alkylene oxide adduct with a polyisocyanate, and then reacting the resulting mixture with a hydroxyalkyl (meth)acrylate.

[0047] In one embodiment, the (meth)acrylic-modified polyurethane can be produced by a method including: (1) reacting an anhydrosugar alcohol-alkylene oxide adduct with a polyisocyanate to produce an intermediate having a terminal isocyanate group; and (2) reacting the intermediate obtained from the step (1) with a hydroxyalkyl (meth)acrylate.

[0048] According to one embodiment, the (meth)acrylic modified polyurethane can be prepared by reacting two equivalents of a diisocyanate with one equivalent of an anhydrous sugar alcohol (e.g., isosorbide (ISB))-alkylene oxide adduct to produce an intermediate having a terminal isocyanate group, and then reacting the terminal isocyanate group of the intermediate with two equivalents of a hydroxyalkyl (meth)acrylate (e.g., 2-hydroxyethyl methacrylate).

[0049] In the case of an acrylic-modified polyurethane prepared using a general alkylene oxide (e.g., ethylene oxide or polypropylene oxide) rather than an anhydrous sugar alcohol-alkylene oxide adduct, problems occur in that the oil resistance of a coating formed from a composition containing it is reduced (when polypropylene oxide is used) and the adhesive strength of a coating formed from a composition containing it is reduced (when ethylene oxide is used).

[0050] According to one embodiment, the reaction of the anhydrosugar alcohol-alkylene oxide adduct with the polyisocyanate can be carried out in the presence of a catalyst (e.g., a tin-based catalyst such as dibutyltin dilaurate (DBTDL)) at room temperature or at an elevated temperature (e.g., 50 to 100°C, preferably 50 to 70°C) for an appropriate time (e.g., 0.1 to 5 hours, preferably 0.5 to 2 hours).

[0051] According to one embodiment, the reaction between the reaction product of the anhydrosugar alcohol-alkylene oxide adduct and the polyisocyanate (i.e., the intermediate obtained in the step (1)) and the hydroxyalkyl (meth)acrylate can be carried out in the presence of a catalyst (e.g., a tin-based catalyst such as dibutyltin dilaurate (DBTDL)) at an elevated temperature (e.g., 50 to 100°C, preferably 50 to 70°C) for an appropriate time (e.g., 0.1 to 5 hours, preferably 0.5 to 2 hours).

[0052] The metal coating composition of the present invention contains 5.1 to 64.9 parts by weight of the (meth)acrylic modified polyurethane relative to 100 parts by weight of the total amount of the composition. If the content of the (meth)acrylic modified polyurethane in 100 parts by weight of the total amount of the composition is less than 5.1 parts by weight, the adhesion of the coating formed from the composition containing it will decrease and the oil resistance will decrease significantly, and conversely, if the amount exceeds 64.9 parts by weight, the adhesion of the coating formed from the composition containing it will decrease.

[0053] More specifically, the content of the (meth)acrylic modified polyurethane in 100 parts by weight of the metal coating composition of the present invention may be, for example, 5.1 parts by weight or more, 5.5 parts by weight or more, 6 parts by weight or more, 6.5 parts by weight or more, 7 parts by weight or more, 7.5 parts by weight or more, 8 parts by weight or more, 8.5 parts by weight or more, 9 parts by weight or more, 9.5 parts by weight or more, or 10 parts by weight or more, and may be 64.9 parts by weight or less, 64.5 parts by weight or less, 64 parts by weight or less, 63.5 parts by weight or less, 63 parts by weight or less, 62.5 parts by weight or less, 62 parts by weight or less, 61.5 parts by weight or less, 61 parts by weight or less, 60.5 parts by weight or less, or 60 parts by weight or less, but is not limited thereto.

[0054] [(Meth)acrylic monomer] The (meth)acrylic monomer contained in the metal coating composition of the present invention can adjust the viscosity of the metal coating composition to improve workability such as applicability to metal, increase the thermal curing speed of the metal coating composition, and improve the strength of the cured product, thereby improving adhesion.

[0055] The (meth)acrylic monomer contained in the metal coating composition of the present invention is a monomer having a (meth)acrylic group in the molecule, and may be preferably a monomer having 1 to 6 (specifically, 1 to 4) (meth)acrylic groups in the molecule, or may be a mixture of two or more kinds.

[0056] In one embodiment, the (meth)acrylic monomer includes a monomer having one (meth)acrylic group, such as (meth)acrylic acid, lauryl (meth)acrylate, stearyl (meth)acrylate, ethyl carbitol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, and benzyl (meth)acrylate. , phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethyl glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, nonylphenoxytetraethyl glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, butoxytriethylene glycol (meth)acrylate, 2-ethoxy Polyhexyl polyethylene glycol (meth)acrylate, nonylphenyl polypropylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycerol (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, epichlorohydrin (hereinafter abbreviated as ECH) modified butyl (meth)acrylate Examples of the methacrylate include, but are not limited to, ethyl phthalate, ECH-modified phenoxy (meth)acrylate, ethylene oxide (hereinafter abbreviated as EO)-modified phthalic acid (meth)acrylate, EO-modified succinic acid (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, and mixtures thereof.

[0057] In another embodiment, the (meth)acrylic monomer may be, for example, a monomer having two or more (meth)acrylic groups, such as, but not limited to, 1,6-hexanediol diacrylate (HDDA), 1,4-butanediol diacrylate (BDDA), tripropylene glycol diacrylate (TPGDA), bisphenol A [EO] 4-30 diacrylate (BPA [EO] 4-30DA, EO is an ethylene oxide unit), trimethylolpropane triacrylate (TMPTA), trimethylolpropane [EO] 3-15 triacrylate (TMP [EO] 3-15TA, EO is an ethylene oxide unit), pentaerythritol triacrylate (PETA), pentaerythritol tetraacrylate (PETTA), ditrimethylolpropane tetraacrylate (DTMPTTA), dipentaerythritol pentaacrylate (DPPA), dipentaerythritol hexaacrylate (DPHA), or a mixture thereof.

[0058] The metal coating composition of the present invention contains 7.1 to 74.9 parts by weight of the (meth)acrylic monomer relative to 100 parts by weight of the total amount of the composition. If the content of the (meth)acrylic monomer in 100 parts by weight of the total amount of the composition is less than 7.1 parts by weight, the adhesion and oil resistance of the coating formed from the composition containing it will be significantly reduced, and conversely, if it exceeds 74.9 parts by weight, the oil resistance of the coating formed from the composition containing it will be significantly reduced.

[0059] More specifically, the content of the (meth)acrylic monomer in 100 parts by weight of the metal coating composition of the present invention may be, for example, 7.1 parts by weight or more, 7.5 parts by weight or more, 8 parts by weight or more, 8.5 parts by weight or more, 9 parts by weight or more, 9.5 parts by weight or more, or 10 parts by weight or more, and may be 74.9 parts by weight or less, 74.5 parts by weight or less, 74 parts by weight or less, 73.5 parts by weight or less, 73 parts by weight or less, 72.5 parts by weight or less, 72 parts by weight or less, 71.5 parts by weight or less, 71 parts by weight or less, 70.5 parts by weight or less, or 70 parts by weight or less, but is not limited thereto.

[0060] [Epoxy resin] The epoxy resin contained in the metal coating composition of the present invention is used to increase the strength and improve the adhesiveness of the cured product of the metal coating composition.

[0061] The epoxy resin is a resin having an epoxy group in the molecule, and may be a resin having preferably two or more epoxy groups in the molecule, or may be a mixture of two or more thereof.

[0062] In one embodiment, the epoxy resin may be, for example, a bisphenol-based epoxy resin, a phenol novolac-based epoxy resin, an o-cresol novolac-based epoxy resin, a multifunctional epoxy resin, an amine-based epoxy resin, a heterocycle-containing epoxy resin, a substituted epoxy resin, a naphthol-based epoxy resin, or a mixture thereof, but is not limited thereto.

[0063] The metal coating composition of the present invention contains 2.1 to 44.9 parts by weight of the epoxy resin relative to 100 parts by weight of the total amount of the composition. If the epoxy resin content is less than 2.1 parts by weight relative to 100 parts by weight of the total amount of the composition, the adhesion of the coating formed from the composition containing it will decrease, and conversely, if it exceeds 44.9 parts by weight, the adhesion of the coating formed from the composition containing it will decrease and the oil resistance will decrease.

[0064] More specifically, the content of the epoxy resin in 100 parts by weight of the metal coating composition of the present invention may be, for example, 2.1 parts by weight or more, 2.5 parts by weight or more, 3 parts by weight or more, 3.5 parts by weight or more, 4 parts by weight or more, 4.5 parts by weight or more, or 5 parts by weight or more, and may be 44.9 parts by weight or less, 44.5 parts by weight or less, 44 parts by weight or less, 43.5 parts by weight or less, 43 parts by weight or less, 42.5 parts by weight or less, 42 parts by weight or less, 41.5 parts by weight or less, 41 parts by weight or less, 40.5 parts by weight or less, 40 parts by weight or less, or 39 parts by weight or less, but is not limited thereto.

[0065] [Epoxy curing accelerator] The epoxy curing accelerator contained in the metal coating composition of the present invention is used to increase the curing speed of the epoxy resin.

[0066] In one embodiment, the epoxy curing accelerator may be, for example, a substituted imidazole (e.g., 1-methylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-cyanoethylimidazole), imidazoline (e.g., 2-phenylimidazoline), tertiary amine (e.g., N,N-dimethylbenzylamine), 2,4,6-tris(dimethylaminomethyl)phenol (DMP30), bisphenol A, bisphenol F, nonylphenol, p-tert-butylphenol, novolac-type phenolic resin, salicylic acid, p-toluenesulfonic acid, 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]Undec-7-ene (DBU), S-triazine (e.g., LUPRAGEN N600), bis(2-dimethylaminoethyl)ether (e.g., LUPRAGEN N206), pentamethyldiethylentriamine (e.g., LUPRAGEN N301), trimethylaminoethylethanolamine (e.g., LUPRAGEN N400), tetramethyl-1,6-hexanediamine (e.g., LUPRAGEN N500), aminoethylmorpholine, aminopropylmorpholine, aminoethylethyleneurea, ketimines (e.g., Epi-Kure 3502) (the reaction product of ethylenediamine and methyl isobutyl ketone), urons (e.g., 3-(4-chlorophenyl)-1,1-dimethylurea (monuron), 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 3-phenyl-1,1-dimethylurea (phenuron), and 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea (chlorotoluron)), tolyl-2,4-bis-N,N-dimethylcarbamide (e.g., AMICURE 3502 ... UR2T), dicyandiamide (DICY), Mannich bases or secondary amines (e.g., dialkylamines of di(2-ethylhexyl)amine, dibutylamine, dipropylamine, ditridecylamine), N,N'-diisopropylisophoronediamine (e.g., JEFFLINK® XTJ-584), N,N'-diisobutyl-4,4'-diaminodicyclohexylmethane (e.g., CLEARLINK 1000), N-(hydroxyethyl)aniline, and di(2-methoxyethyl)amine or combinations thereof.

[0067] The metal coating composition of the present invention contains 0.051 to 2.49 parts by weight of the epoxy curing accelerator relative to 100 parts by weight of the total amount of the composition. If the epoxy resin content is less than 0.051 parts by weight relative to 100 parts by weight of the total amount of the composition, the composition containing it does not cure and a coating is not formed, and conversely, if it exceeds 2.49 parts by weight, the adhesion and oil resistance of the coating formed from the composition containing it are significantly reduced.

[0068] More specifically, the content of the epoxy curing accelerator in 100 parts by weight of the metal coating composition of the present invention may be, for example, 0.051 parts by weight or more, 0.055 parts by weight or more, 0.06 parts by weight or more, 0.065 parts by weight or more, 0.07 parts by weight or more, 0.075 parts by weight or more, 0.08 parts by weight or more, 0.085 parts by weight or more, 0.09 parts by weight or more, 0.095 parts by weight or more, or 0.1 parts by weight or more, and may be, but is not limited to, 2.49 parts by weight or less, 2.45 parts by weight or less, 2.4 parts by weight or less, 2.35 parts by weight or less, 2.3 parts by weight or less, 2.25 parts by weight or less, 2.2 parts by weight or less, 2.15 parts by weight or less, 2.1 parts by weight or less, 2.05 parts by weight or less, 2 parts by weight or less, 1.5 parts by weight or less, or 1 part by weight or less.

[0069] [Thermal polymerization initiator] The thermal polymerization initiator contained in the metal coating composition of the present invention is used to initiate polymerization of the (meth)acrylic monomer and the (meth)acrylic-modified polyurethane and promote curing.

[0070] In one embodiment, the thermal polymerization initiator is represented by the following formula (3-1): [ka] (wherein R and R' are each independently a C2-C8 linear or C3-C8 branched alkyl group; a C3-C20 cycloalkyl group; a C6-C20 aryl group; or a C2-C8 linear or C3-C8 branched methoxy-alkyl group; X is -CN or -CO2R'', where R'' is a C2-C8 linear or C3-C8 branched alkyl group; a C3-C20 cycloalkyl group; or a C6-C20 aryl group; [ka] (wherein R is, independently, a C2-C8 linear or C3-C8 branched alkyl group; a C3-C20 cycloalkyl group; or a C6-C20 aryl group;) or a mixture thereof.

[0071] The metal coating composition of the present invention contains the thermal polymerization initiator in an amount of 0.00051 to 2.49 parts by weight relative to 100 parts by weight of the total amount of the composition. If the content of the thermal polymerization initiator in 100 parts by weight of the total amount of the composition is less than 0.00051 parts by weight, the composition containing it does not cure and a coating is not formed, and conversely, if it exceeds 2.49 parts by weight, the adhesion and oil resistance of the coating formed from the composition containing it are significantly reduced.

[0072] More specifically, the content of the thermal polymerization initiator in 100 parts by weight of the metal coating composition of the present invention is, for example, 0.00051 parts by weight or more, 0.00055 parts by weight or more, 0.0006 parts by weight or more, 0.00065 parts by weight or more, 0.0007 parts by weight or more, 0.00075 parts by weight or more, 0.0008 parts by weight or more, 0.00085 parts by weight or more, 0.0009 parts by weight or more, 0.00095 parts by weight or more, 0.001 parts by weight or more. , 0.005 parts by weight or more, or 0.01 parts by weight or more, and may be 2.49 parts by weight or less, 2.45 parts by weight or less, 2.4 parts by weight or less, 2.35 parts by weight or less, 2.3 parts by weight or less, 2.25 parts by weight or less, 2.2 parts by weight or less, 2.15 parts by weight or less, 2.1 parts by weight or less, 2.05 parts by weight or less, 2 parts by weight or less, 1.5 parts by weight or less, 1 part by weight or less, or 0.5 parts by weight or less, but is not limited thereto.

[0073] In addition to the components described above, the metal coating composition of the present invention may further contain additives that can be conventionally used in metal paint compositions.

[0074] [Method of manufacturing metal coating composition] According to another aspect of the present invention, there is provided a method for producing a metal coating composition, comprising a step of mixing, relative to a total of 100 parts by weight of a mixture, 5.1 to 64.9 parts by weight of (meth)acrylic modified polyurethane; 7.1 to 74.9 parts by weight of (meth)acrylic monomer; 2.1 to 44.9 parts by weight of epoxy resin; 0.051 to 2.49 parts by weight of an epoxy curing accelerator; and 0.00051 to 2.49 parts by weight of a thermal polymerization initiator, wherein the (meth)acrylic modified polyurethane comprises i) polymerization units derived from an anhydrosugar alcohol-alkylene oxide adduct; ii) polymerization units derived from a polyisocyanate; and iii) polymerization units derived from a hydroxyalkyl (meth)acrylate.

[0075] In the method for preparing a metal coating composition of the present invention, the specific types and amounts of the (meth)acrylic modified polyurethane, (meth)acrylic monomer, epoxy resin, epoxy curing accelerator and thermal polymerization initiator are the same as those described above.

[0076] In a preferred embodiment, the (meth)acrylic-modified polyurethane, (meth)acrylic monomer, epoxy resin, epoxy curing accelerator, and thermal polymerization initiator can be mixed at a temperature of 60° C. or lower (for example, 10 to 60° C., more specifically, 20 to 60° C.). If the temperature condition for mixing the components is too high above 60° C., a polymerization reaction of the (meth)acrylic monomer may proceed during mixing, causing hardening during the composition production process, and it may become difficult to use the resulting product as a coating composition.

[0077] [Coated metal articles] According to yet another aspect of the present invention, there is provided a coated metal article comprising: a metal article; and a coating layer of the metal coating composition of the present invention on a surface of the metal article.

[0078] In one embodiment, the metal article may be, but is not limited to, a mechanical, electrical, or electronic component.

[0079] The method for forming a coating layer of the metal coating composition of the present invention on the metal article is not particularly limited, and can be carried out using a conventionally known coating method and apparatus.

[0080] The present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited thereto.

[0081] Working Example <Production of anhydrosugar alcohol-alkylene oxide adduct> Production Example A1: Production of isosorbide-ethylene oxide 5 mole adduct In a pressurizable reactor, 146 g of isosorbide and 0.15 g of phosphoric acid (85%) as an acid component were added, the reactor was replaced with nitrogen, heated to 100°C, and reduced in pressure under vacuum to remove moisture in the reactor. Next, 88 g of ethylene oxide was slowly added to the reactor in the first increment, and reacted at a temperature of 100°C to 140°C for 2 to 3 hours. At this time, the reaction temperature was adjusted so as not to exceed 140°C. Then, the internal temperature of the reactor was cooled to 50°C, 0.3 g of potassium hydroxide was added to the reactor, the reactor was replaced with nitrogen, heated to 100°C, and reduced in pressure under vacuum to remove moisture in the reactor. Next, 132 g of ethylene oxide was slowly added in the second increment, and reacted at 100°C to 140°C for 2 to 3 hours. After the reaction was completed, the inside of the reactor was cooled to 50°C, 4.0g of Ambosol MP20 was added as an adsorbent, the inside of the reactor was reheated, and the mixture was stirred at 100°C to 120°C for 1 to 5 hours to remove metal ions (at this time, the inside of the reactor was substituted with nitrogen and / or depressurized under vacuum). After it was confirmed that no metal ions were detected, the inside of the reactor was cooled to 60°C to 90°C, and residual by-products were removed to obtain 362g of a transparent liquid isosorbide-ethylene oxide 5 mole adduct.

[0082] Production Example A2: Production of isosorbide-ethylene oxide 10 mole adduct The same method as in Production Example A1 was carried out except that the amount of ethylene oxide added in the second addition was changed from 132 g to 352 g, thereby obtaining 551 g of a transparent liquid isosorbide-ethylene oxide 10 mol adduct.

[0083] Production Example A3: Production of isosorbide-propylene oxide 5 mole adduct Propylene oxide was used instead of ethylene oxide as a raw material for the addition reaction. Specifically, 116 g of propylene oxide was added in the first reaction instead of 88 g of ethylene oxide, and then 174 g of propylene oxide was added in the second reaction instead of 132 g of ethylene oxide, but the same method as in Production Example A1 was carried out to obtain 423 g of a transparent liquid isosorbide-propylene oxide 5 mole adduct.

[0084] Production Example A4: Production of isosorbide-propylene oxide 10 mole adduct Propylene oxide was used instead of ethylene oxide as an addition reaction raw material. Specifically, 116 g of propylene oxide was added in the first addition instead of 88 g of ethylene oxide, and 465 g of propylene oxide was added in the second addition instead of 132 g of ethylene oxide, but the same method as in Production Example A1 was carried out to obtain 698 g of a transparent liquid isosorbide-propylene oxide 10 mol adduct.

[0085] <Production of (meth)acrylic modified polyurethane> Production Example B1: Production of (meth)acrylic modified polyurethane using isosorbide-ethylene oxide 5 mole adduct as polyol, isophorone diisocyanate (IPDI) as polyisocyanate, and 2-hydroxyethyl methacrylate as hydroxyalkyl (meth)acrylate In a three-necked glass reactor with stirring, 222 g of isophorone diisocyanate (IPDI) and 0.1 g of dibutyltin dilaurate (DBTDL) as a reaction catalyst were added. While stirring this mixture at room temperature, 183 g of the isosorbide-ethylene oxide 5 mole adduct obtained in Production Example A1 was slowly added to carry out a crosslinking reaction. After the addition of the isosorbide-ethylene oxide 5 mole adduct was completed, the mixture was stirred and aged at 50°C for 1 hour, and 65 g of 2-hydroxyethyl methacrylate was slowly added to carry out an acrylic modification reaction. After the addition of 2-hydroxyethyl methacrylate, the mixture was stirred and aged at 50°C for 1 hour, and the reaction product was cooled to room temperature to obtain 467 g of a (meth)acrylic modified polyurethane of the following formula (A). [ka]

[0086] Production Example B2: Production of (meth)acrylic modified polyurethane using isosorbide-ethylene oxide 10 mole adduct as polyol, hexamethylene diisocyanate (HDI) as polyisocyanate, and 2-hydroxyethyl acrylate as hydroxyalkyl (meth)acrylate The same method as in Production Example B1 was carried out except that 168 g of hexamethylene diisocyanate (HDI) was used instead of isophorone diisocyanate (IPDI) as the polyisocyanate, 293 g of the isosorbide-ethylene oxide 10 mol adduct obtained in Production Example A2 was used instead of the isosorbide-ethylene oxide 5 mol adduct obtained in Production Example A1 as the polyol, and 58 g of 2-hydroxyethyl acrylate was used instead of 2-hydroxyethyl methacrylate as the hydroxyalkyl (meth)acrylate, to obtain 515 g of a (meth)acrylic-modified polyurethane of the following formula (B). [ka]

[0087] Production Example B3: Production of (meth)acrylic modified polyurethane using isosorbide-propylene oxide 5 mole adduct as polyol, methylene diphenyl diisocyanate (MDI) as polyisocyanate, and 2-hydroxyethyl methacrylate as hydroxyalkyl (meth)acrylate The same method as in Production Example B1 was carried out except that 250 g of methylene diphenyl diisocyanate (MDI) was used instead of isophorone diisocyanate (IPDI) as the polyisocyanate, and 218 g of the isosorbide-propylene oxide 5 mol adduct obtained in Production Example A3 was used instead of the isosorbide-ethylene oxide 5 mol adduct obtained in Production Example A1 as the polyol, to obtain 529 g of a (meth)acrylic-modified polyurethane of the following formula (C). [ka]

[0088] Production Example B4: Production of (meth)acrylic modified polyurethane using isosorbide-propylene oxide 10 mole adduct as polyol, isophorone diisocyanate (IPDI) as polyisocyanate, and 2-hydroxyethyl methacrylate as hydroxyalkyl (meth)acrylate The same method as in Production Example B1 was carried out except that 363 g of the isosorbide-propylene oxide 10 mol adduct obtained in Production Example A4 was used instead of the isosorbide-ethylene oxide 5 mol adduct obtained in Production Example A1 as the polyol, to obtain 643 g of a (meth)acrylic-modified polyurethane of the following formula (D). [ka]

[0089] Production Example B5: Production of (meth)acrylic modified polyurethane using isosorbide as polyol, isophorone diisocyanate (IPDI) as polyisocyanate, and 2-hydroxyethyl methacrylate as hydroxyalkyl (meth)acrylate The same method as in Production Example B1 was carried out except that 146 g of isosorbide was used as the polyol instead of the isosorbide-ethylene oxide 5 mole adduct obtained in Production Example A1, to obtain 431 g of a (meth)acrylic modified polyurethane of the following formula (E). [ka]

[0090] Production Example B6: Production of (meth)acrylic modified polyurethane using polyethylene glycol (number average molecular weight: 500 g / mol) as polyol, isophorone diisocyanate (IPDI) as polyisocyanate, and 2-hydroxyethyl methacrylate as hydroxyalkyl (meth)acrylate 782 g of a (meth)acrylic-modified polyurethane of the following formula (F) was obtained by carrying out the same method as in Production Example B1, except that 500 g of polyethylene glycol (number average molecular weight: 500 g / mol) was used as the polyol instead of the isosorbide-ethylene oxide 5 mole adduct obtained in Production Example A1. [ka]

[0091] Production Example B7: Production of (meth)acrylic modified polyurethane using polypropylene glycol (number average molecular weight: 500 g / mol) as polyol, hexamethylene diisocyanate (HDI) as polyisocyanate, and 2-hydroxyethyl acrylate as hydroxyalkyl (meth)acrylate 720 g of a (meth)acrylic-modified polyurethane of the following formula (G) was obtained by carrying out the same method as in Production Example B1, except that 168 g of hexamethylene diisocyanate (HDI) was used instead of isophorone diisocyanate (IPDI) as the polyisocyanate, 500 g of polypropylene glycol (number average molecular weight: 500 g / mol, manufactured by KUMHO PETROCHEMICAL) was used instead of the isosorbide-ethylene oxide 5 mole adduct obtained in Production Example A1 as the polyol, and 58 g of 2-hydroxyethyl acrylate was used instead of 2-hydroxyethyl methacrylate as the hydroxyalkyl (meth)acrylate. [ka]

[0092] Production Example B8: Production of (meth)acrylic modified polyurethane using polytetramethylene glycol (number average molecular weight: 1,000 g / mol) as polyol, methylene diphenyl diisocyanate (MDI) as polyisocyanate, and 2-hydroxyethyl methacrylate as hydroxyalkyl (meth)acrylate The same method as in Production Example B1 was carried out except that 250 g of methylene diphenyl diisocyanate (MDI) was used instead of isophorone diisocyanate (IPDI) as the polyisocyanate, and 1,000 g of polytetramethylene glycol (number average molecular weight: 1,000 g / mol, manufactured by Sigma-Aldrich Corporation) was used instead of the isosorbide-ethylene oxide 5 mole adduct obtained in Production Example A1 as the polyol, to obtain 1,308 g of a (meth)acrylic-modified polyurethane represented by the following formula (H). [ka]

[0093] <Production of Oil-Resistant Coating Composition for Metals> Examples A1 to A4 and Comparative Examples A1 to A14: Standard Production Method A liquid oil-resistant coating composition for metal was produced by adding (meth)acrylic-modified polyurethane, (meth)acrylic monomer, epoxy resin, epoxy curing accelerator and thermal polymerization initiator in the weight ratio shown in Table 1 below to a mixing reactor kept at 60°C or less and stirring and mixing at a temperature of 60°C or less. At this time, the total content of the (meth)acrylic-modified polyurethane, (meth)acrylic monomer, epoxy resin, epoxy curing accelerator and thermal polymerization initiator was 100 parts by weight.

[0094] <Ingredients> (1) (Meth)acrylic modified polyurethane (acrylic modified PU) Production Example B1: (Meth)acrylic modified polyurethane of formula (A) obtained in Production Example B1 Production Example B2: (Meth)acrylic modified polyurethane of formula (B) obtained in Production Example B2 Production Example B3: (Meth)acrylic modified polyurethane of formula (C) obtained in Production Example B3 Production Example B4: (Meth)acrylic modified polyurethane of formula (D) obtained in Production Example B4 Production Example B5: (Meth)acrylic modified polyurethane of formula (E) obtained in Production Example B5 Production Example B6: (Meth)acrylic modified polyurethane of formula (F) obtained in Production Example B6 Production Example B7: (Meth)acrylic modified polyurethane of formula (G) obtained in Production Example B7 Production Example B8: (Meth)acrylic modified polyurethane of formula (H) obtained in Production Example B8

[0095] (2) (Meth)acrylic monomer 2-HEMA: 2-hydroxyethyl methacrylate (manufactured by Samchun Pure Chemical Co., Ltd.) 4-HBA: 4-hydroxybutyl acrylate (manufactured by Samchun Pure Chemical Co., Ltd.) BA: Butyl acrylate (manufactured by Samchun Pure Chemical Co., Ltd.) PETTA: Pentaerythritol tetraacrylate (Miwon Commercial) P-2M: 2-methacryloyloxyethyl acid phosphate (Kyoei Chemical Co., Ltd.) BDDA: 1,4-butanediol diacrylate (Aldrich)

[0096] (3) Epoxy resin YD-128: Bisphenol A epoxy resin (KUKDO CHEMICAL) YDF-170: Bisphenol F epoxy resin (KUKDO CHEMICAL) 1,4-BDGE: 1,4-butanediol diglycidyl ether (KUKDO CHEMICAL)

[0097] (4) Epoxy curing accelerator DICY: Dicyandiamide (manufactured by Evonik) UR2T: 1,1'-(4-methyl-m-phenylene)bis(3,3-dimethylurea) (Evonik)

[0098] (5) Thermal polymerization initiator V-65: 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by Fuji Film Co., Ltd.) V-40: 1,1'-azobis(cyclohexane-1-carbonitrile) (manufactured by Fuji Film) Peroyl TCP: Bis(4-t-butylcyclohexyl) peroxydicarbonate (manufactured by Nichiyu)

[0099] [Table 1] [Table 1-1] [Table 1-2] [Table 1-3]

[0100] <Evaluation of physical properties of oil-resistant metal coating composition> The oil-resistant metal coating compositions prepared in Examples A1 to A4 and Comparative Examples A1 to A14 were applied to the surface of two rolled steel plates cut to a size of 2.5 cm x 12 cm in an area of ​​2.5 cm x 2.0 cm, and the two rolled steel plates were overlapped and fixed together at the applied portions, and heated and cured at 150°C for 5 minutes to prepare metal bonded specimens. The adhesion and oil resistance of each specimen were evaluated according to the following methods, and the results are shown in Table 2 below.

[0101] <Physical property measurement method> (1) Adhesiveness To evaluate the adhesion of the metal coating composition to metal, the shear strength (MPa) of each metal adhesive test piece was measured using a UTM (Instron 5967, manufactured by Instron). Specifically, the shear strength of each metal adhesive test piece was measured five times in total, and the average value was calculated. The higher the shear strength, the higher the adhesion.

[0102] (2) Oil resistance The metal bonded specimens were immersed in mineral oil (manufactured by Daejung Chemical Co., Ltd.) and heated at 190°C for 200 hours, and the shear strength of each metal bonded specimen immersed in the adhesion measurement method described in (1) above was measured five times and the average value was calculated. Then, the reduction rate (%) of the shear strength after immersion relative to the shear strength before immersion of each metal bonded specimen was calculated. The lower the reduction rate of the shear strength, the better the oil resistance. Shear strength reduction rate (%) = (shear strength before immersion - shear strength after immersion) x 100 / shear strength before immersion

[0103] [Table 2]

[0104] As shown in Table 2, the metal adhesion test pieces of Examples A1 to A4 to which the coating composition containing the (meth)acrylic modified polyurethane according to the present invention was applied had good metal adhesion and a shear strength of 16 MPa or more. Even when immersed in mineral oil at 190°C for 200 hours, the reduction rate of the shear strength was less than 30%, and the adhesion strength was well maintained and the oil resistance was also good.

[0105] However, the adhesion was poor in the case of the metal bonded specimens of Comparative Examples A1 and A2. In addition, the shear strength of the metal bonded specimens of Comparative Examples A3 and A4 was significantly reduced after immersion in high-temperature mineral oil, and the oil resistance was poor. In the case of the metal bonded specimen of Comparative Example A5, both adhesion and oil resistance were very poor, and in the case of the metal bonded specimen of Comparative Example A6, the adhesion was poor. In addition, the adhesion was very poor in the case of the metal bonded specimen of Comparative Example A7. In the case of the metal bonded specimen of Comparative Example A8, the oil resistance was very poor, and after immersion in mineral oil and heating, spontaneous peeling of the metal bonded specimen was observed. In the case of the metal bonded specimens of Comparative Examples A9 and A10, the adhesion was poor. In the case of the metal bonded specimens of Comparative Examples A11 and A13, the metal coating composition was not cured, so the adhesion and oil resistance could not be evaluated. In the case of the metal bonded specimens of Comparative Examples A12 and A14, both adhesion and oil resistance were poor.

[0106] As described above, in the case of a metal coating composition containing the (meth)acrylic-modified polyurethane according to the present invention in a specific range of amount, the adhesion to metal was excellent, the adhesion was well maintained even in high-temperature mineral oil, and the oil resistance was also good.

Claims

1. Based on 100 parts by weight of the total amount of the composition, (Meth)acrylic modified polyurethane: 5.1 to 64.9 parts by weight; 7.1 to 74.9 parts by weight of (meth)acrylic monomer; 2.1 to 44.9 parts by weight of epoxy resin; 0.051 to 2.49 parts by weight of an epoxy curing accelerator; and 0.00051 to 2.49 parts by weight of a thermal polymerization initiator; the (meth)acrylic-modified polyurethane comprises: i) a polymerization unit derived from an anhydrosugar alcohol-alkylene oxide adduct; ii) a polymerization unit derived from a polyisocyanate; and iii) a polymerization unit derived from a hydroxyalkyl (meth)acrylate; The anhydrosugar alcohol-alkylene oxide adduct is an adduct obtained by reacting hydroxyl groups at both ends or one end of an anhydrosugar alcohol with an alkylene oxide, wherein the alkylene oxide is a linear alkylene oxide having 2 to 8 carbon atoms or a branched alkylene oxide having 3 to 8 carbon atoms; The anhydrosugar alcohol is isosorbide, isomannide, isoidide or a mixture thereof. Coating compositions for metals.

2. The polyisocyanate is methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), or a combination thereof. The metal coating composition according to claim 1.

3. The hydroxyalkyl (meth)acrylate is hydroxy-C 1－８ It is an alkyl (meth)acrylate. The metal coating composition according to claim 1.

4. The (meth)acrylic modified polyurethane is represented by the following formula (2): 【Chemistry 1】 (In the formula, each R is independently an alkylene group, Each R2 is independently an alkylene group, a cycloalkylene group, or an arylene group; Each R3 is independently an alkylene group; Each R is independently a hydrogen atom or an alkyl group; M is a divalent organic group derived from an anhydrosugar alcohol; m and n each independently represent an integer of 0 to 15; m+n represents an integer of 1 to 30. The metal coating composition according to claim 1.

5. The (meth)acrylic monomer is a monomer having 1 to 4 (meth)acrylic groups in the molecule. The metal coating composition according to claim 1.

6. The epoxy resin is a resin having two or more epoxy groups in a molecule. The metal coating composition according to claim 1.

7. The thermal polymerization initiator is represented by the following formula (3-1): 【Chemistry 2】 wherein R and R' are each independently a C2-C8 linear or C3-C8 branched alkyl group; a C3-C20 cycloalkyl group; a C6-C20 aryl group; or a C2-C8 linear or C3-C8 branched methoxy-alkyl group; X is -CN or -CO 2 R" where R" is a C2-C8 linear or C3-C8 branched alkyl group; a C3-C20 cycloalkyl group; or a C6-C20 aryl group. a compound represented by the following formula (3-2): 【Chemistry 3】 (wherein, each R is independently a C2-C8 linear or C3-C8 branched alkyl group; a C3-C20 cycloalkyl group; or a C6-C20 aryl group) or a mixture thereof. The metal coating composition according to claim 1.

8. For a total of 100 parts by weight of the mixture, (Meth)acrylic modified polyurethane: 5.1 to 64.9 parts by weight; 7.1 to 74.9 parts by weight of (meth)acrylic monomer; 2.1 to 44.9 parts by weight of epoxy resin; 0.051 to 2.49 parts by weight of an epoxy curing accelerator; and 0.00051 to 2.49 parts by weight of a thermal polymerization initiator; mixing the the (meth)acrylic-modified polyurethane comprises: i) a polymerization unit derived from an anhydrosugar alcohol-alkylene oxide adduct; ii) a polymerization unit derived from a polyisocyanate; and iii) a polymerization unit derived from a hydroxyalkyl (meth)acrylate; The anhydrosugar alcohol-alkylene oxide adduct is an adduct obtained by reacting hydroxyl groups at both ends or one end of an anhydrosugar alcohol with an alkylene oxide, wherein the alkylene oxide is a linear alkylene oxide having 2 to 8 carbon atoms or a branched alkylene oxide having 3 to 8 carbon atoms; The anhydrosugar alcohol is isosorbide, isomannide, isoidide or a mixture thereof; A method for producing a metal coating composition.

9. The mixing of the (meth)acrylic modified polyurethane, the (meth)acrylic monomer, the epoxy resin, the epoxy curing accelerator, and the thermal polymerization initiator is carried out under a temperature condition of 60° C. or less. A method for producing the metal coating composition according to claim 8.

10. Metal articles; and A coating layer of the metal coating composition according to any one of claims 1 to 7 on the surface of the metal article; 4. A coated metal article comprising:

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