Polyaspartic coating composition and coated film

Abstract

To provide a polyaspartic coating composition that yields a coating film with excellent flexibility and adhesion to the substrate while maintaining high hardness and chemical resistance.SOLUTION: A polyaspartic coating composition comprises an aspartic acid ester compound (A), polyisocyanate compositions (B) and (C), where a mass ratio of (C) to (B) is 5 / 95 to 95 / 5; (B) is derived from an aliphatic and / or alicyclic diisocyanate, contains isocyanurate groups in an amount of 30% or more when a total of mole numbers of whole functional groups is taken as 100%, has a molar ratio of allophanate groups to isocyanurate groups of 1 / 99 to 70 / 30, has a weight average molecular weight of 500 to 1200, and has a viscosity at 25°C of 50 to 1500 mPa s; and (C) is derived from an aliphatic and / or alicyclic diisocyanate and a polycaprolactone polyol having a number average molecular weight of 500 to 1500 and has an isocyanate group content of 15 mass% or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to polyaspartic coating compositions and coatings. [Background technology]

[0002] Among polyurea coating compositions, polyaspartic coating compositions, which are aliphatic, are formed from aspartic acid ester compounds containing amino groups and aliphatic and / or alicyclic polyisocyanate compositions containing isocyanate groups. The drawback of aromatic polyurea coating compositions, that is, yellowing of the coating film due to exposure to ultraviolet light, is greatly reduced, and the compositions have been used in a wide range of applications, such as flooring and waterproofing materials.

[0003] Aspartic acid ester compounds have a lower viscosity than the main polyol of polyurethane coating compositions, and can greatly reduce the amount of dilution solvent in the polyaspartic coating composition, making it possible to make high solid formulations or solvent-free formulations. In addition, since the reactivity between the amino group of the aspartic acid ester compound and the isocyanate group of the aliphatic and / or alicyclic polyisocyanate is fast, the polyaspartic coating composition has the characteristics of a faster curing speed even at room temperature and excellent mechanical strength compared to polyurethane coating compositions.

[0004] For example, Patent Document 1 discloses a polyaspartic coating composition, which is an aliphatic polyurea coating composition, consisting of a polyamine component containing a secondary amino group having an aspartic acid ester skeleton and a polyisocyanate component containing an isocyanate group in an aliphatic polyisocyanate composition. The coating composition has a relatively long pot life and high coating hardness, and therefore can be applied without using a high-pressure impingement mixer sprayer.

[0005] Patent Document 2 discloses a polyaspartic paint composition containing a polyaspartic acid ester compound and a polyisocyanate composition in which the contents (mol %) of isocyanurate groups, iminooxadiazinedione groups, uretdione groups, allophanate groups, and biuret groups are in a specified relationship. In this polyaspartic paint composition, the polyisocyanate composition has a low viscosity suitable for high solid formulations and solventless formulations, and while maintaining curability and drying properties, the coating film using this polyaspartic paint composition has the advantage of being excellent in chemical resistance, hardness, and weather resistance.

[0006] Furthermore, Patent Document 3 describes optimizing the viscosity of a polyaspartic coating composition, which has the advantages of having good viscosity and pot life under solvent-free conditions, and excellent appearance, chemical resistance, impact resistance, and scratch resistance when formed into a coating film.

[0007] However, there is no mention of the adhesion to a substrate or the flexibility of a coating film formed from the polyaspartic coating composition proposed in Patent Document 2 or Patent Document 3. In addition, there is room for further improvement in terms of viscosity and pot life. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 3-43472 [Patent Document 2] International Publication No. 2018 / 163953 [Patent Document 3] JP 2022-66853 A Summary of the Invention [Problem to be solved by the invention]

[0009] Conventional polyaspartic coatings are tough and inflexible, limiting their use to flooring and waterproofing materials. In addition, they have weaker adhesion to substrates than general acrylic, silicone, and fluorine-based polyol paints, and adhesion to metal materials in particular has been a problem.

[0010] It is therefore an object of the present invention to provide a polyaspartic coating composition and a coating film which are excellent in flexibility and adhesion to substrates while maintaining high hardness and chemical resistance of the resulting coating film. [Means for solving the problem]

[0011] That is, the present invention includes the following aspects. [1] A composition comprising an aspartic acid ester compound (A), a first polyisocyanate composition (B), and a second polyisocyanate composition (C), a mass ratio of the second polyisocyanate composition (C) to the first polyisocyanate composition (B) is 5 / 95 to 95 / 5; The aspartic acid ester compound (A) is an aspartic acid ester compound represented by the following general formula (I):

[0012] [ka]

[0013] (In general formula (I), X 11 R is an n11-valent organic group obtained by removing the primary amino group of an n11-valent polyamine. 11 and R 12 are the same or different organic groups that are inactive to isocyanate groups under reaction conditions. n11 is an integer of 2 or more. The first polyisocyanate composition (B) is a polyisocyanate composition derived from an aliphatic diisocyanate and / or an alicyclic diisocyanate, Contains at least two or more of an isocyanurate group, an allophanate group, a uretdione group, a uretoneimino group, a urethane group, a biuret group, a urea group, and an iminooxadiazinedione group, Ba) containing 30% or more isocyanurate groups having a structure represented by the following general formula (II), when the sum of the number of moles of isocyanurate groups, allophanate groups, uretdione groups, uretonimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups is taken as 100%,

[0014] [ka]

[0015] Bb) the molar ratio of allophanate groups derived from a monoalcohol having 1 to 20 carbon atoms to isocyanurate groups is 1 / 99 to 70 / 30; Bc) the weight average molecular weight is 500 or more and 1200 or less, and Bd) A polyisocyanate composition having a viscosity of 50 mPa·s or more and 1500 mPa·s or less at 25°C under solvent-free conditions, The second polyisocyanate composition (C) is a polyisocyanate composition derived from an aliphatic diisocyanate and / or an alicyclic diisocyanate and a polycaprolactone polyol having a number average molecular weight of 500 or more and 1500 or less, and has an isocyanate group content of 15 mass% or less, which is a polyaspartic paint composition. [2] The polyaspartic coating composition according to [1], wherein the average number of isocyanate functional groups of each of the first polyisocyanate composition (B) and the second polyisocyanate composition (C) is 2.0 or more and 4.0 or less. [3] The polyaspartic paint composition according to [1] or [2], wherein the molar ratio of the isocyanate groups of the first polyisocyanate composition (B) and the second polyisocyanate composition (C) to the amino groups of the aspartic acid ester compound (A) is 1 / 10 or more and 10 / 1 or less. [4] The polyaspartic coating composition according to [1] or [2], wherein the aliphatic diisocyanate and / or alicyclic diisocyanate of the first polyisocyanate composition (B) and the second polyisocyanate composition (C) includes hexamethylene diisocyanate. [5] A coating film obtained by curing the polyaspartic coating composition described in [1] or [2]. [6] A coating film obtained by curing the polyaspartic coating composition according to [1] or [2], the coating film having a tensile breaking stress of 7 MPa or more and an elongation of 40% or more. [7] A coating film having a Konig hardness of 40 or more, obtained by curing the polyaspartic coating composition described in [1] or [2]. Effect of the Invention

[0016] According to the polyaspartic coating composition of this embodiment, it is possible to provide high breaking stress and high elongation while maintaining the hardness and chemical resistance of the coating film, and it is possible to follow cracks and fissures of substrates such as concrete and deformation of soft substrates such as plastics. In addition, it has improved adhesion to the substrate to which it is applied, particularly to metals that have been difficult to use in the past. Furthermore, it is possible to improve the convenience of the coating work due to the low viscosity that is easier to mix and the long pot life, and it is also effective in improving the appearance of the coating. Therefore, it is useful not only for conventional flooring and waterproofing applications, but also for adhesives, pressure sensitive adhesives, elastomers, sealing materials, foams, fiber treatments, synthetic leather treatments, surface treatment agents, etc. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0018] In this specification, the term "polyol" refers to a compound having two or more hydroxyl groups (-OH). In this specification, the term "polyisocyanate" refers to a reaction product in which a plurality of monomer compounds having one or more isocyanate groups (--NCO) (hereinafter abbreviated as "isocyanate monomers") are bonded together.

[0019] <Polyaspartic paint composition> The polyaspartic coating composition of this embodiment contains an aspartic acid ester compound (A), a first polyisocyanate composition (B), and a second polyisocyanate composition (C), and the mass ratio of the second polyisocyanate composition (C) to the first polyisocyanate composition (B) is 5 / 95 to 95 / 5. The aspartic acid ester compound (A) is an aspartic acid ester compound represented by the following general formula (I).

[0020] [ka]

[0021] (In general formula (I), X 11 R is an n11-valent organic group obtained by removing the primary amino group of an n11-valent polyamine. 11 and R 12 are the same or different organic groups that are inactive to isocyanate groups under reaction conditions. n11 is an integer of 2 or more.

[0022] The first polyisocyanate composition (B) is a polyisocyanate composition derived from an aliphatic diisocyanate and / or an alicyclic diisocyanate, Contains at least two or more of an isocyanurate group, an allophanate group, a uretdione group, a uretoneimino group, a urethane group, a biuret group, a urea group, and an iminooxadiazinedione group, Ba) containing 30% or more isocyanurate groups having a structure represented by the following general formula (II), when the sum of the number of moles of isocyanurate groups, allophanate groups, uretdione groups, uretonimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups is taken as 100%, Bb) the molar ratio of allophanate groups derived from a monoalcohol having 1 to 20 carbon atoms to isocyanurate groups is 1 / 99 to 70 / 30; Bc) the weight average molecular weight is 500 or more and 1200 or less, and Bd) A polyisocyanate composition having a viscosity of 50 mPa·s or more and 1,500 mPa·s or less at 25°C under solvent-free conditions.

[0023] [ka]

[0024] The second polyisocyanate composition (C) is a polyisocyanate composition derived from an aliphatic diisocyanate and / or alicyclic diisocyanate and a polycaprolactone polyol having a number average molecular weight of 500 or more and 1500 or less, and has an isocyanate group content of 15 mass% or less.

[0025] <Aspartic acid ester compound (A)> The polyaspartic coating composition of the present embodiment contains an aspartic acid ester compound (A) as a main component. The aspartic acid ester compound (A) is a compound represented by the above general formula (I).

[0026] In the general formula (I), X 11 R is an n11-valent organic group obtained by removing the primary amino group of an n11-valent polyamine. 11 and R 12 are the same or different organic groups which are inert to isocyanate groups under reaction conditions. n11 is an integer of 2 or more.

[0027] X in formula (I) 11is not particularly limited, but from the viewpoint of yellowing resistance, it is preferable that it is an organic group based on an aliphatic and / or alicyclic polyamine having no aromatic group, for example, an n11-valent polyamine selected from the following group: ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12- The organic groups are based on diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4- and / or 2,6-hexahydrotolylenediamine, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4,4'-triamino-5-methyldicyclohexylmethane, and polyether polyamines having a number average molecular weight of 148 or more and 6000 or less and in which primary amino groups are aliphatically bonded. Among them, X 11 The organic group is preferably an organic group based on 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 4,4'-diaminodicyclohexylmethane, or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, and more preferably an organic group based on 4,4'-diaminodicyclohexylmethane or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0028] R in formula (I) 11 and R 12 As defined in , "inert towards isocyanate groups under reaction conditions" means that these groups do not contain Zerewitinoff active hydrogen-containing groups (CH acidic compounds), such as hydroxyl, amino, or thiol groups. R 11 and R 12are preferably, independently of one another, an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl group, an ethyl group, or a butyl group.

[0029] In formula (I), n11 is preferably an integer of 2 or more and 6 or less, more preferably an integer of 2 or more and 4 or less, and even more preferably 2.

[0030] A preferred aspartic acid ester compound (A) is, for example, an aspartic acid ester compound derived from two molecules of aspartic acid having a secondary amino group and one molecule of 4,4'-diaminodicyclohexylmethane.

[0031] Commercially available aspartic acid ester compounds (A) may be used. Commercially available aspartic acid ester compounds (A) include, for example, Evonik's product names "Amicure IC-221" (amine value 188 mg KOH / resin g, viscosity 450 mPa.s (representative value measured at 25 ° C)), "Amicure IC-321" (amine value 190 mg KOH / resin g, viscosity 450 mPa.s (representative value measured at 25 ° C)), "Amicure IC-322" (amine value 189 mg KOH / resin g, viscosity 150 mPa.s (representative value measured at 25 ° C)), and Feiyang's product names "Feispartic F420" (amine value 192 mg KOH / resin g, viscosity 1450 mPa.s (representative value measured at 25 ° C)), "Feispartic F520" (amine value 189 mg KOH / resin g, viscosity 1400 mPa.s (representative value measured at 25 ° C)).

[0032] The above-mentioned aspartic acid ester compounds (A) may be used alone or in combination of two or more. In particular, the polyaspartic coating composition of this embodiment preferably contains a combination of two types of aspartic acid ester compounds (A) having different reactivities, which improves the pot life and the appearance of the resulting coating film. The reactivity here means the reactivity with a curing agent component (e.g., an isocyanate group of a polyisocyanate composition). The reactivity of the aspartic acid ester compound (A) with a curing agent component can be evaluated using the amine value of the aspartic acid ester compound as an index.

[0033] The method for producing the aspartic acid ester compound (A) is not particularly limited, but for example, it is produced by reacting a primary polyamine represented by the following formula (IV) with a maleic acid ester or a fumaric acid ester represented by the following formula (V).

[0034] X 11 -[NH2] n11 (IV) R 11 OOC-CH=CH-COOR 12 (V)

[0035] (In the above formula (IV), X 11 and n11 have the same meaning as that represented by formula (I), and in formula (V), R 11 and R 12 has the same meaning as that represented by formula (I).

[0036] Suitable polyamines include, but are not limited to, X 11 The diamines mentioned above are the basis for the

[0037] Suitable maleic acid esters or fumaric acid esters are not particularly limited, but include, for example, R 11 and R 12 The group defined in R 11 and R 12 Among them, R 11 and R 12 is an alkyl group having 1 to 10 carbon atoms, and dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, diethyl fumarate, or dibutyl fumarate is more preferred.

[0038] The preparation of the aspartic acid ester compound (A) from the starting materials described is preferably carried out in the temperature range from 0° C. to 100° C. The starting materials are used in a ratio such that at least one, preferably only one, olefinic double bond is present in each of the primary amino groups. If desired, the reaction can be followed by distillation to remove excess starting materials. The reaction can be carried out in bulk or in the presence of a suitable solvent, such as, but not limited to, methanol, ethanol, propanol or dioxane, or a mixture of such solvents.

[0039] <First polyisocyanate composition (B)> The polyaspartic coating composition of this embodiment contains a first polyisocyanate composition (B) as a curing agent component. The first polyisocyanate composition (B) is derived from an aliphatic diisocyanate and / or an alicyclic diisocyanate, that is, a reaction product of two or more molecules of a diisocyanate monomer.

[0040] The first polyisocyanate composition (B) contains at least two types of isocyanurate groups, allophanate groups, uretdione groups, uretonimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups (hereinafter also referred to as "total functional groups"). These functional groups have at least one nitrogen atom derived from the isocyanate group of the diisocyanate monomer, and the nitrogen atom is bonded to an organic group derived from the diisocyanate monomer. When the diisocyanate monomer is selected from an aliphatic diisocyanate and / or an alicyclic diisocyanate, the nitrogen atom has a methylene group (-CH2-), a methine group (-CH<), or the like.

[0041] The first polyisocyanate composition (B) contains 30% or more of isocyanurate groups represented by the general formula (II) when the sum of the moles of all functional groups is 100%. The molar ratio of isocyanurate groups to all functional groups is preferably 30% or more and 90% or less, more preferably 35% or more and 90% or less, more preferably 40% or more and 90% or less, more preferably 45% or more and 90% or less, more preferably 50% or more and 90% or less, more preferably 55% or more and 85% or less, and more preferably 57% or more and 85% or less. When the molar ratio of isocyanurate groups to all functional groups is equal to or greater than the above lower limit, chemical resistance can be exhibited, whereas when the molar ratio is equal to or less than the above upper limit, good coating appearance can be achieved.

[0042] The molar ratio of the isocyanurate groups to the total functional groups in the first polyisocyanate composition (B) can be measured, for example, by the method described in the Examples below.

[0043] As a method for adjusting the molar ratio of isocyanurate groups to fall within the above range, for example, a method of adjusting the molar ratio by appropriately using the method described later in the "Production method of the first polyisocyanate composition (B)" can be mentioned.

[0044] [Diisocyanate monomer] In the first polyisocyanate composition (B), the diisocyanate monomer is at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0045] The aliphatic diisocyanate is not particularly limited, but is preferably an aliphatic diisocyanate having 4 to 30 carbon atoms, such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as "HDI"), 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, and lysine diisocyanate. Among these, HDI is more preferable because of its industrial availability. The above-listed aliphatic diisocyanates may be used alone or in combination of two or more.

[0046] The alicyclic diisocyanate is not particularly limited, but is preferably an alicyclic diisocyanate having 8 to 30 carbon atoms, such as isophorone diisocyanate (hereinafter abbreviated as "IPDI"), 1,3-bis(isocyanatomethyl)-cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, norbornene diisocyanate, and hydrogenated xylylene diisocyanate. Among them, IPDI is more preferable in terms of weather resistance and industrial availability. The above-mentioned alicyclic diisocyanates may be used alone or in combination of two or more.

[0047] As the diisocyanate monomer, one or more aliphatic diisocyanates and one or more alicyclic diisocyanates can be used in combination.

[0048] [Method for producing the first polyisocyanate composition (B)] The method for producing the first polyisocyanate composition (B) will be described below. The first polyisocyanate composition (B) can be obtained by simultaneously producing an isocyanurate reaction to form an isocyanurate group and an allophanate reaction to form an allophanate group in the presence of an excess of diisocyanate monomer, and removing the unreacted diisocyanate monomer after completion of the reaction. Alternatively, the above reactions may be carried out separately and the polyisocyanates obtained from each may be mixed in a specific ratio. From the viewpoint of ease of production, it is preferable to carry out the above reactions at once to obtain a polyisocyanate, and from the viewpoint of freely adjusting the content of each functional group, it is preferable to produce them separately and then mix them.

[0049] Examples of catalysts for deriving a polyisocyanate containing an isocyanurate group from a diisocyanate monomer include commonly used isocyanuration reaction catalysts. The isocyanurate reaction catalyst is not particularly limited, but is preferably one that is generally basic, and examples thereof include (1) hydroxides of tetraalkylammonium such as tetramethylammonium, tetraethylammonium, and tetrabutylammonium; organic weak acid salts such as acetates, octylates, myristates, and benzoates thereof; (2) hydroxides of hydroxyalkylammonium such as trimethylhydroxyethylammonium, trimethylhydroxypropylammonium, triethylhydroxyethylammonium, and triethylhydroxypropylammonium; organic weak acid salts such as acetates, octylates, myristates, and benzoates thereof; (3) metal salts of alkylcarboxylic acids such as tin, zinc, and lead, such as acetate, caproic acid, octylate, and myristic acid; (4) metal alcoholates such as sodium and potassium; (5) aminosilyl group-containing compounds such as hexamethylenedisilazane; (6) Mannich bases; (7) combined use of tertiary amines and epoxy compounds; and (8) phosphorus-based compounds such as tributylphosphine.

[0050] Among these, from the viewpoint of preventing the generation of unnecessary by-products, a weak organic acid salt of a quaternary ammonium is preferable, and a weak organic acid salt of a tetraalkylammonium is more preferable.

[0051] The upper limit of the amount of the isocyanurate reaction catalyst used is preferably 1000 ppm by mass, more preferably 500 ppm by mass, and even more preferably 100 ppm by mass, based on the mass of the charged isocyanate monomer. On the other hand, the lower limit of the amount of the isocyanurate reaction catalyst used is not particularly limited, and may be, for example, 10 ppm by mass.

[0052] The isocyanurate reaction temperature is preferably from 50° C. to 120° C., and more preferably from 60° C. to 90° C. By keeping the isocyanurate reaction temperature at or below the upper limit, coloration of the polyisocyanate tends to be more effectively suppressed.

[0053] When a desired conversion rate (the ratio of the mass of polyisocyanate produced in the isocyanuration reaction to the mass of the charged isocyanate monomer) is reached, the isocyanuration reaction is stopped by adding an acidic compound (e.g., phosphoric acid, an acidic phosphoric acid ester, etc.).

[0054] In order to obtain polyisocyanate, it is necessary to stop the reaction at an early stage. However, since the reaction rate of the isocyanurate reaction is very fast at the early stage, it is difficult to stop the reaction at an early stage, and therefore the reaction conditions, particularly the amount and method of adding the catalyst, must be carefully selected. For example, a method of adding the catalyst in portions at regular intervals is recommended as a suitable method.

[0055] Therefore, the conversion rate of the isocyanurate reaction to obtain a polyisocyanate is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. When the conversion rate of the isocyanurate reaction is equal to or less than the above upper limit, the first polyisocyanate composition (B) can have a low viscosity that is more suitable for high-solid formulations and solventless formulations.

[0056] When deriving a polyisocyanate containing an isocyanurate group, a monohydric to hexahydric alcohol can be used in addition to the above isocyanate monomers. Examples of the alcohol having a hydric acid of from 1 to 6 and a hydric acid of from 1 to 6 that can be used include non-polymerizable alcohols and polymerizable alcohols.

[0057] Examples of the non-polymerizable alcohol include polyhydric alcohols such as monoalcohols, diols, triols, and tetraols. Examples of monoalcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n-pentanol, n-hexanol, n-octanol, n-nonanol, 2-ethylbutanol, 2,2-dimethylhexanol, 2-ethylhexanol, cyclohexanol, methylcyclohexanol, and ethylcyclohexanol. Examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 2-methyl-2,3-butanediol, and Examples of the hexanediol include hexanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 2-ethyl-hexanediol, 1,2-octanediol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-diethyl-1,3-propanediol. Examples of triols include glycerin and trimethylolpropane. An example of the tetraols is pentaerythritol.

[0058] The polymerizable alcohol is not particularly limited, but for example, the average number of hydroxyl groups in the polymerizable alcohol is preferably 3 or more and 8 or less, more preferably 3 or more and 6 or less, even more preferably 3 or more and 5 or less, and particularly preferably 3 or 4. Specific examples of the polymerizable alcohol include polyester polyol, polyether polyol, acrylic polyols, polyolefin polyols, and the like.

[0059] The catalyst for deriving a polyisocyanate containing an allophanate group from a diisocyanate monomer is not particularly limited, and examples thereof include alkyl carboxylates of tin, lead, zinc, bismuth, zirconium, zirconyl, etc.; organic tin compounds such as tin 2-ethylhexanoate and dibutyltin dilaurate; organic lead compounds such as lead 2-ethylhexanoate; organic zinc compounds such as zinc 2-ethylhexanoate; bismuth 2-ethylhexanoate, zirconium 2-ethylhexanoate, and zirconyl 2-ethylhexanoate. These may be used alone or in combination of two or more.

[0060] The above-mentioned isocyanurate reaction catalyst can also be an allophanate reaction catalyst. When the above-mentioned isocyanurate reaction catalyst is used to carry out an allophanate reaction, an isocyanurate group-containing polyisocyanate is naturally produced. From the viewpoint of economical production, it is preferable to carry out the allophanate reaction and the isocyanurate reaction using the above-mentioned isocyanurate reaction catalyst as the allophanate reaction catalyst.

[0061] The above-mentioned allophanate reaction catalyst is preferably 10 mass ppm or more and 1000 mass ppm or less with respect to the mass of the charged diisocyanate monomer. The lower limit is more preferably 20 mass ppm, more preferably 40 mass ppm, and even more preferably 80 mass ppm. The upper limit is more preferably 800 mass ppm, more preferably 600 mass ppm, and even more preferably 500 mass ppm or less. The allophanate reaction temperature is preferably 40° C. or more and 180° C. or less. The lower limit is more preferably 60° C., more preferably 80° C., and even more preferably 100° C. The upper limit is more preferably 160° C., and even more preferably 140° C. By setting the allophanate reaction temperature to 40° C. or more, it tends to be possible to maintain a high reaction rate. By setting the allophanate reaction temperature to 180° C. or less, it tends to be possible to effectively suppress coloration of the polyisocyanate.

[0062] The alcohol that can be used to form the allophanate group is a monoalcohol having 1 to 20 carbon atoms, and more preferably a monoalcohol having a molecular weight of 200 or less. Specific compounds are not particularly limited, but examples thereof include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, 2-ethylhexanol, etc. These may be used alone or in combination of two or more.

[0063] After the reaction is completed, unreacted diisocyanate monomer is removed from the reaction solution by thin-film distillation, extraction, or the like, to obtain the polyisocyanate used in the present embodiment.

[0064] An antioxidant or an ultraviolet absorber may be added to the obtained polyisocyanate, for example, for the purpose of suppressing coloration during storage. Examples of the antioxidant include hindered phenols such as 2,6-di-t-butyl-p-cresol. Examples of the ultraviolet absorber include benzotriazole and benzophenone. These may be used alone or in combination of two or more. The amount of these added is preferably 10 ppm by mass or more and 500 ppm by mass or less based on the total mass of the first polyisocyanate composition (B).

[0065] [Physical Properties of the First Polyisocyanate Composition (B)] In the first polyisocyanate composition (B), the molar ratio of the allophanate group derived from a monoalcohol having 1 to 20 carbon atoms to the isocyanurate group is 1 / 99 to 70 / 30, preferably 20 / 80 to 70 / 30, and more preferably 25 / 70 to 50 / 50. The molar ratio of the allophanate group to the isocyanurate group can be measured, for example, by the method described in the Examples below.

[0066] The weight average molecular weight of the first polyisocyanate composition (B) is 500 or more and 1,200 or less, preferably 500 or more and 1,000 or less, and more preferably 500 or more and 800 or less. By having a weight-average molecular weight equal to or greater than the above lower limit, chemical resistance tends to be better maintained, whereas by having a weight-average molecular weight equal to or less than the above upper limit, the viscosity of the polyaspartic coating composition of this embodiment at 25°C immediately after preparation under solvent-free conditions is more suitable for solvent-free formulations, and the pot life of the polyaspartic coating composition of this embodiment tends to be longer. The weight average molecular weight can be measured by the method described in the Examples below.

[0067] The lower limit of the isocyanate content (hereinafter also referred to as "NCO content") of the first polyisocyanate composition (B) is preferably 10 mass%, more preferably 13 mass%, and even more preferably 15 mass%, relative to the total mass (100 mass%) of the first polyisocyanate composition (B). On the other hand, the upper limit of the NCO content of the first polyisocyanate composition (B) is preferably 30 mass%, more preferably 27 mass%, and even more preferably 25 mass%. That is, the NCO content of the first polyisocyanate composition (B) is preferably 10% by mass or more and 30% by mass or less, more preferably 13% by mass or more and 27% by mass or less, and even more preferably 15% by mass or more and 25% by mass or less. By having the NCO content be equal to or greater than the above lower limit, chemical resistance tends to be better maintained, whereas by having the NCO content be equal to or less than the above upper limit, the diisocyanate monomer mass concentration tends to be adjusted to a more suitable range. The NCO content can be measured, for example, by the method described in the Examples below.

[0068] The viscosity of the first polyisocyanate composition (B) at 25°C under solvent-free conditions is 50 mPa·s or more and 1500 mPa·s or less. The lower limit of the viscosity is preferably 50 mPa·s, more preferably 100 mPa·s, even more preferably 200 mPa·s, and particularly preferably 300 mPa·s. On the other hand, the upper limit of the viscosity is 1500 mPa·s, preferably 1000 mPa·s, more preferably 800 mPa·s, even more preferably 600 mPa·s, and particularly preferably 550 mPa·s. That is, the viscosity of the first polyisocyanate composition (B) at 25°C is preferably 50 mPa·s or more and 1000 mPa·s or less, more preferably 100 mPa·s or more and 800 mPa·s or less, even more preferably 200 mPa·s or more and 600 mPa·s or less, and particularly preferably 300 mPa·s or more and 550 mPa·s or less. When the viscosity is equal to or higher than the lower limit, workability during formulation of the coating material tends to be maintained, whereas when the viscosity is equal to or lower than the upper limit, the viscosity at 25°C immediately after preparation of the polyaspartic coating material composition of this embodiment under solvent-free conditions is more suitable for solvent-free formulation, and the pot life of the polyaspartic coating material composition of this embodiment tends to be extended. The viscosity can be measured by the method described in the Examples below.

[0069] The average number of isocyanate groups (hereinafter also referred to as the "average number of functional groups") of the first polyisocyanate composition (B) is preferably 2.0 or more and 4.0 or less. The lower limit of the average number of isocyanate groups is preferably 2.0, more preferably 2.2, even more preferably 2.4, particularly preferably 2.6, and most preferably 2.8. On the other hand, the upper limit of the average number of isocyanate groups is preferably 6.0, more preferably 5.0, even more preferably 4.0, particularly preferably 3.5, and most preferably 3.0. That is, the average number of isocyanate groups in the first polyisocyanate composition (B) is preferably 2.0 or more and 6.0 or less, more preferably 2.2 or more and 5.0 or less, even more preferably 2.3 or more and 4.0 or less, and most preferably 2.4 or more and 3.5 or less. By having the average number of isocyanate groups be equal to or greater than the above lower limit, chemical resistance tends to be better maintained. On the other hand, by having the average number of isocyanate groups be equal to or less than the above upper limit, the viscosity at 25°C immediately after preparation of the polyaspartic coating composition of this embodiment under solvent-free conditions is more suitable for solvent-free formulations, and the pot life of the polyaspartic coating composition of this embodiment tends to be further extended and the appearance of the coating film formed therefrom tends to be further improved. The average number of isocyanate groups can be measured by the method described in the Examples below.

[0070] The diisocyanate monomer mass concentration of the first polyisocyanate composition (B) is preferably 1.0 mass% or less, more preferably 0.5 mass% or less, and even more preferably 0.3 mass% or less, relative to the total mass (100 mass%) of the first polyisocyanate composition (B). By having the diisocyanate monomer mass concentration be equal to or less than the above upper limit, there is a tendency that chemical resistance can be better maintained. The diisocyanate monomer mass concentration can be measured by the method described in the Examples below.

[0071] <Second Polyisocyanate Composition (C)> The second polyisocyanate composition (C) used in the present embodiment is derived from an aliphatic diisocyanate and / or alicyclic diisocyanate and a polycaprolactone polyol having a number average molecular weight of 500 or more and 1500 or less, and has an isocyanate group content of 15 mass % or less.

[0072] The isocyanate group content (hereinafter also referred to as "NCO content") of the second polyisocyanate composition (C) used in this embodiment is 15% by mass or less with respect to the total amount (100% by mass) of the polyisocyanate composition. The lower limit of the NCO content is more preferably 6% by mass, and even more preferably 7% by mass. The upper limit of the NCO content is preferably 15% by mass. By having an NCO content of 5% by mass or more, it tends to be possible to better maintain drying properties and curing properties. By having an NCO content of 15% by mass or less, it tends to be possible to improve the scratch resistance of the coating film using the polyaspartic coating composition of this embodiment. The NCO content can be measured by the method described in the examples below.

[0073] The viscosity of the second polyisocyanate composition (C) used in this embodiment at 25°C is preferably 500 mPa.s or more and 50000 mPa.s or less. The lower limit of the viscosity is more preferably 1000 mPa.s, even more preferably 1500 mPa.s, and even more preferably 2000 mPa.s. The upper limit of the viscosity is more preferably 40000 mPa.s, even more preferably 30000 mPa.s, and even more preferably 25000 mPa.s. By having a viscosity of 500 mPa.s or more, the scratch resistance of the coating film using the polyaspartic coating composition of this embodiment tends to be improved. By having a viscosity of 50000 mPa.s or less, the drying property tends to be better maintained. The viscosity can be measured by the method described in the examples described below.

[0074] The weight average molecular weight of the second polyisocyanate composition (C) used in this embodiment is preferably 600 or more and 5000 or less. The lower limit of the weight average molecular weight is more preferably 800, even more preferably 1000, and even more preferably 1200. The upper limit of the weight average molecular weight is more preferably 4000, even more preferably 3000, and even more preferably 2000. By having a weight average molecular weight of 600 or more, the scratch resistance of the coating film using the polyaspartic coating composition of this embodiment tends to be improved. By having a weight average molecular weight of 5000 or less, the drying property tends to be better maintained. The weight average molecular weight can be measured by the method described in the examples below.

[0075] The average number of isocyanate groups (hereinafter also referred to as "average number of functional groups") of the second polyisocyanate composition (C) used in this embodiment is preferably 2.0 or more and 4.0 or less. The lower limit of the average number of isocyanate groups is more preferably 2.2, even more preferably 2.4, even more preferably 2.6, and even more preferably 2.8. The upper limit of the average number of isocyanate groups is preferably 4.0. By having the average number of isocyanate groups of 2.0 or more, there is a tendency that the drying property can be better maintained. By having the average number of isocyanate groups of 4.0 or less, there is a tendency that the scratch resistance and weather resistance of the coating film using the polyaspartic coating composition of this embodiment can be improved. The average number of isocyanate groups can be measured by the method described in the examples described later.

[0076] The diisocyanate monomer mass concentration of the second polyisocyanate composition (C) used in this embodiment is preferably 1.0 mass% or less, more preferably 0.5 mass% or less, and even more preferably 0.3 mass% or less, based on the total amount (100 mass%) of the polyisocyanate components. By having the diisocyanate monomer mass concentration of 1.0 mass% or less, there is a tendency that the drying property can be better maintained. The diisocyanate monomer mass concentration can be measured by the method described in the examples below.

[0077] The content of isocyanurate in the second polyisocyanate composition (C) used in this embodiment is preferably 10% by mass or less (i.e., 0% by mass or more than 0% by mass to 10% by mass, the same applies below) relative to the total amount of the polyisocyanate components (100% by mass). More preferably, it is 8.0% by mass or less, even more preferably 6.0% by mass or less, and even more preferably 4.0% by mass or less. By making the content of isocyanurate 10% by mass or less, there is a tendency that the scratch resistance of the coating film using the polyaspartic coating composition of this embodiment can be improved.

[0078] ·Diisocyanate monomers The diisocyanate monomer used in this embodiment is selected from the group consisting of aliphatic and alicyclic diisocyanates. The aliphatic diisocyanate used in the present embodiment is not particularly limited, but is preferably an aliphatic diisocyanate having 4 to 30 carbon atoms, such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as "HDI"), 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, and lysine diisocyanate. Among these, HDI is more preferable because of its industrial availability. The above-listed aliphatic diisocyanates may be used alone or in combination of two or more.

[0079] The alicyclic diisocyanate used in the present embodiment is not particularly limited, but is preferably an alicyclic diisocyanate having 8 to 30 carbon atoms, such as isophorone diisocyanate (hereinafter abbreviated as "IPDI"), 1,3-bis(isocyanatomethyl)-cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, norbornene diisocyanate, and hydrogenated xylylene diisocyanate. Among them, IPDI is more preferable in terms of weather resistance and industrial availability. The above-mentioned alicyclic diisocyanates may be used alone or in combination of two or more.

[0080] As the diisocyanate monomer, one or more aliphatic diisocyanates and one or more alicyclic diisocyanates can be used in combination.

[0081] Polycaprolactone polyol The polycaprolactone polyol used in the present embodiment is a polycaprolactone polyol having a number average molecular weight of 500 to 1500. It is preferably a divalent to tetravalent polyol containing a repeating unit represented by -O(CH2)5CO-, and can be derived from a divalent to tetravalent alcohol and ε-caprolactone or the like. In addition, although there is no particular limitation, for example, it can be obtained by ring-opening polymerization of ε-caprolactone or the like using a divalent to tetravalent alcohol as an initiator in the presence of a catalyst.

[0082] The number average molecular weight of the polycaprolactone polyol is 500 or more and 1,500 or less, preferably 500 or more and 1,200 or less, and more preferably 500 or more and 1,000 or less.

[0083] As the initiator, dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, etc., trihydric alcohols such as trimethylene glycol, glycerin, etc., and tetrahydric alcohols such as pentaerythritol, etc. are used. From the viewpoint of obtaining a polyisocyanate component with a low viscosity, branched polyhydric alcohols are preferred.

[0084] As the catalyst, organic titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, etc., tin compounds such as tin octoate, dibutyltin oxide, dibutyltin laurate, stannous chloride, stannous bromide, etc. are preferably used. From the viewpoint of adjusting the caprolactone dimer content to the range specified in the present application, tin compounds are preferred.

[0085] The ring-opening polymerization of ε-caprolactone or the like is preferably carried out in a nitrogen gas atmosphere by setting the molar ratio of ε-caprolactone and the above initiator so as to obtain a predetermined molecular weight, adding 0.1 ppm to 100 ppm of a catalyst relative to ε-caprolactone, and reacting for 4 hours to 10 hours at a temperature of 150° C. to 200° C. However, it is important to control the caprolactone dimer content to 100 ppm to 1000 ppm at the end of the reaction. If necessary, the caprolactone dimer may be removed from the produced polycaprolactone polyol by a method such as extraction or distillation. In addition to ε-caprolactone, other cyclic lactones such as trimethylcaprolactone and valerolactone may be partially mixed.

[0086] (Method for producing second polyisocyanate composition (C)) A method for producing the second polyisocyanate composition (C) used in this embodiment will be described. The second polyisocyanate composition (C) used in this embodiment can be obtained by reacting an isocyanate group of a diisocyanate monomer with a hydroxyl group of a polycaprolactone polyol in the presence of an excess of a diisocyanate monomer, carrying out a urethane reaction to form a urethane group, and then removing the unreacted diisocyanate monomer. The urethanization reaction temperature is preferably from 50 to 160° C., more preferably from 60 to 120° C. By setting the urethanization reaction temperature at 160° C. or less, coloration of the polyisocyanate tends to be effectively suppressed. The urethanization reaction time is preferably from 30 minutes to 4 hours, more preferably from 1 to 3 hours, and even more preferably from 1 to 2 hours.

[0087] The equivalent ratio of the isocyanate group of the diisocyanate monomer to the hydroxyl group of the polycaprolactone polyol is preferably isocyanate group:hydroxyl group=2:1 or more and 50:1 or less. When the equivalent ratio is isocyanate group:hydroxyl group=2:1 or more, the aliphatic and / or alicyclic polyisocyanate component tends to be able to exhibit a low viscosity suitable for high solid formulations and solventless formulations. When the equivalent ratio is isocyanate group:hydroxyl group=50:1 or less, the yield of polyisocyanate tends to be increased.

[0088] <Mass ratio of polyisocyanate compositions (B) and (C)> The mass ratio of the second polyisocyanate composition (C) to the first polyisocyanate composition (B) is 5 / 95 to 95 / 5, preferably 10 / 90 to 90 / 10, even more preferably 20 / 80 to 80 / 20, and most preferably 25 / 75 to 75 / 25. When the mass ratio of (C) / (B) is equal to or greater than the lower limit, the adhesion and elongation of the resulting coating film tend to be improved, whereas when the mass ratio of (C) / (B) is equal to or less than the upper limit, the pot life and hardness of the coating tend to be improved.

[0089] <Isocyanate group / Amino group> The molar ratio of the isocyanate groups in the polyisocyanate compositions (B) and (C) to the amino groups in the aspartic acid ester compound (A) (isocyanate groups / amino groups) is preferably 1 / 10 or more and 10 / 1 or less, more preferably 3 / 10 or more and 10 / 3 or less, and even more preferably 5 / 10 or more and 10 / 5 or less. When the ratio of isocyanate groups / amino groups is equal to or more than the above lower limit, the appearance and chemical resistance of a coating film tend to be further improved. On the other hand, by having the isocyanate group / amino group ratio be equal to or less than the above upper limit, the pot life of the coating material tends to be improved.

[0090] <Other resin components> The polyaspartic paint composition of the present embodiment may further contain a polyvalent active hydrogen compound as another resin component (another main component) in addition to the aspartic acid ester compound (A) and the polyisocyanate compositions (B) and (C).

[0091] [Polyvalent active hydrogen compounds] The polyvalent active hydrogen compound is not particularly limited, but may be, for example, polyol, polyamine, alkanolamine, etc. These polyvalent active hydrogen compounds may be contained alone or in combination of two or more. Among them, the polyvalent active hydrogen compound is preferably polyol.

[0092] (Polyol) Examples of polyols include polyester polyols, polyether polyols, acrylic polyols, polyolefin polyols, fluorine polyols, polycarbonate polyols, polyurethane polyols, etc. These polyols may be contained alone or in combination of two or more. Among these, the polyol is preferably a polyester polyol or an acrylic polyol.

[0093] 1. Polyester polyol The polyester polyol can be obtained, for example, by subjecting a dibasic acid, or a mixture of two or more kinds, and a polyhydric alcohol, or a mixture of two or more kinds, to a condensation reaction.

[0094] Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0095] Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane.

[0096] Alternatively, for example, polycaprolactones obtained by ring-opening polymerization of lactones such as ε-caprolactone with polyhydric alcohols can also be used as polyester polyols.

[0097] 2. Polyether polyol The polyether polyols are not particularly limited, but examples thereof include the following (1) to (3). (1) Polyether polyols obtained by random or block addition of an alkylene oxide or a mixture of alkylene oxides to a polyhydric hydroxy compound or a mixture of polyhydric hydroxy compounds using a catalyst. Examples of the catalyst include hydroxides (lithium, sodium, potassium, etc.), strongly basic catalysts (alcoholates, alkylamines, etc.), composite metal cyanide complexes (metal porphyrins, zinc hexacyanocobaltate complexes, etc.), and the like. Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide. (2) Polyether polyols obtained by reacting a polyamine compound with an alkylene oxide. Examples of the polyamine compound include ethylenediamines. Examples of the alkylene oxide include the same as those exemplified in (1). (3) Polymer polyols obtained by polymerizing acrylamide or the like using the polyether polyols obtained in (1) or (2) as a medium.

[0098] Examples of the polyhydric hydroxy compound include the following compounds (i) to (vi). (i) Diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc. (ii) Sugar alcohol compounds such as erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnitol. (iii) Monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, and ribosaccharides. (iv) Disaccharides such as trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, and melibiose. (v) Trisaccharides such as raffinose, gentianose, and melezitose. (vi) Tetrasaccharides such as stachyose.

[0099] 3. Acrylic polyol The acrylic polyol is not particularly limited, but examples thereof include those obtained by copolymerizing a single or mixture of an ethylenically unsaturated bond-containing monomer having a hydroxy group with a single or mixture of other ethylenically unsaturated bond-containing monomers copolymerizable therewith.

[0100] The ethylenically unsaturated bond-containing monomer having a hydroxy group is not particularly limited, but examples thereof include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl methacrylate. These may be used alone or in combination of two or more. Among them, hydroxyethyl acrylate or hydroxyethyl methacrylate is preferred.

[0101] Examples of other ethylenically unsaturated bond-containing monomers copolymerizable with the above monomers include the following (1) to (6), which may be used alone or in combination of two or more. (1) Acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, benzyl acrylate, and phenyl acrylate. (2) Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, and phenyl methacrylate. (3) Unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid. (4) Unsaturated amides such as acrylamide, methacrylamide, N,N-methylenebisacrylamide, diacetone acrylamide, diacetone methacrylamide, maleic acid amide, and maleimide. (5) Vinyl monomers such as glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, and dibutyl fumarate. (6) Vinyl monomers having a hydrolyzable silyl group, such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and γ-(meth)acryloxypropyltrimethoxysilane.

[0102] 4. Polyolefin polyol The polyolefin polyol is not particularly limited, but examples thereof include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene.

[0103] The number of hydroxyl groups statistically possessed by one molecule of the polyol (hereinafter, sometimes referred to as the "average number of hydroxyl groups") is preferably at least 2. When the average number of hydroxyl groups of the polyol is at least 2, there is a tendency that the decrease in the crosslink density of the coating film obtained by curing the one-component coating composition of the present embodiment can be further suppressed.

[0104] 5. Fluoropolyol In this specification, the term "fluorine polyol" refers to a polyol containing fluorine in the molecule. Specific examples of the fluorine polyol include copolymers of fluoroolefin, cyclovinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid vinyl ester, etc., as disclosed in JP-A-57-34107 (Reference 1) and JP-A-61-275311 (Reference 2), etc.

[0105] 6. Polycarbonate polyol The polycarbonate polyols are not particularly limited, but examples thereof include the following (1) to (4). (1) Dialkyl carbonates such as dimethyl carbonate; (2) Alkylene carbonates such as ethylene carbonate; (3) diaryl carbonates such as diphenyl carbonate; (4) A product obtained by condensation polymerization of low molecular weight carbonate compounds such as those described in (1) to (3) above.

[0106] 7. Polyurethane polyol The polyurethane polyol is not particularly limited, but can be obtained, for example, by reacting a polyol not containing a carboxy group with an isocyanate component in a conventional manner. Examples of the polyol not containing a carboxy group include low molecular weight ones such as ethylene glycol and propylene glycol, and high molecular weight ones such as acrylic polyol, polyester polyol, polyether polyol, etc.

[0107] (Hydroxyl value of polyol) The hydroxyl value per resin of the polyol is not particularly limited, but is preferably 10 mg KOH / g resin or more and 300 mg KOH / g resin or less. By having the hydroxyl value per resin be equal to or greater than the lower limit, the crosslink density is prevented from decreasing, and the desired physical properties tend to be more fully achieved. By having the hydroxyl value per resin be equal to or less than the upper limit, the crosslink density is prevented from increasing excessively, and the mechanical properties of the coating film obtained by curing the one-component coating composition of the present embodiment tend to be further improved. The hydroxyl value of the polyol can be measured in accordance with JIS K1557.

[0108] (Hydroxyl group / Isocyanate group) In the polyaspartic coating composition of this embodiment, when a polyol is contained, the molar ratio of the hydroxyl groups of the polyol to the isocyanate groups of the polyisocyanate compositions (B) and (C) (hydroxyl groups / isocyanate groups) is preferably 1 / 10 or more and 10 / 1 or less.

[0109] (Polyamine) The polyamine is not particularly limited, but is preferably one having two or more primary amino groups or secondary amino groups in one molecule, and more preferably one having three or more primary amino groups or secondary amino groups in one molecule. Specific examples of polyamines include the following (1) to (3). (1) Diamines such as ethylenediamine, propylenediamine, butylenediamine, triethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine; (2) Chain polyamines having three or more amino groups, such as bishexamethylenetriamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenehexamine, and tetrapropylenepentamine; (3) Cyclic polyamines such as 1,4,7,10,13,16-hexaazacyclooctadecane, 1,4,7,10-tetraazacyclodecane, 1,4,8,12-tetraazacyclopentadecane, and 1,4,8,11-tetraazacyclotetradecane.

[0110] (Alkanolamines) As used herein, the term "alkanolamine" refers to a compound having an amino group and a hydroxyl group in one molecule. Specific examples of alkanolamines include monoethanolamine, diethanolamine, aminoethylethanolamine, N-(2-hydroxypropyl)ethylenediamine, mono-, di-(n- or iso-)propanolamine, ethylene glycol-bis-propylamine, neopentanolamine, and methylethanolamine.

[0111] <Other ingredients> The polyaspartic coating composition of the present embodiment may further contain an existing melamine resin, epoxy resin, or polyurethane resin, as necessary.

[0112] In addition, when the above-mentioned polyol has a carboxy group, an oxazoline group-containing compound and a carbodiimide group-containing compound can be blended.In addition, when the above-mentioned polyol has a carbonyl group, a hydrazide group-containing compound and a semicarbazide group-containing compound can be blended.These compounds may be blended alone or in combination of two or more.

[0113] The polyaspartic coating composition of the present embodiment preferably further contains a surface conditioner as an additive, since the appearance of the coating film is more excellent. The type of surface conditioner is not particularly limited, and examples thereof include silicone-based and acrylic-based surface conditioners. The content of the surface conditioner is preferably 0.05% by mass or more and 5% by mass or less based on the resin content of the polyaspartic coating composition. By making the content of the surface conditioner equal to or more than the lower limit, the appearance of the coating film can be improved. On the other hand, by making the content of the surface conditioner equal to or less than the upper limit, the coating film can have better cissing resistance, recoatability, and stain resistance.

[0114] As the silicone-based surface conditioner, commercially available products can be used, for example, BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-326, BYK-330, BYK-331, BYK-333, BYK-342, BYK-370, BYK-375, BYK-377, BYK-378, BYK-3760 (manufactured by BYK); Disparlon 1711EF, Disparlon 1761, Disparlon LS-001, Disparlon LS-050, Disparlon LS-280, Disparlon LS-460, Disparlon LS-480 (manufactured by Kusumoto Chemicals); Tego Flow 425, Tego Glide 100, Tego Glide 110, Tego Glide 130, Tego Glide 406, Tego Glide 420, Tego Glide 432, Tego Glide 435, Tego Glide 440, Tego Glide 450, Tego Glide 482, Tego Glide 485, Tego Glide ZG400, Tego wet KL245, Tego wet 250, Tego wet 260, Tego wet 265, Tego wet 270, Tego wet 280 (manufactured by Evonic Tego Chemie), etc. These may be used alone or in combination of two or more.

[0115] The acrylic surface conditioner may be a commercially available product, such as BYK-350, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-361N, BYK-392, BYK-394, BYK-3441 (manufactured by BYK Co., Ltd.); Disparlon LF-1983, Disparlon LF-1984, LF-1985, Disparlon UVX-35, Disparlon UVX-36 (manufactured by Kusumoto Chemicals Co., Ltd.); Tego Flow 300, Tego Flow 370, Tego Flow ATF2, Tego Flow ZFS460, etc. These may be used alone or in combination of two or more.

[0116] As the above-mentioned other types of surface conditioners, commercially available products can be used, for example, BYK-399, BYK-3440, BYK-3550, BYK-3560, BYK-3565, BYK-SILCLEAN 3700, BYK-SILCLEAN 3701, BYKETOL-OK (manufactured by BYK Co., Ltd.); Disparlon UVX-272, Disparlon UVX-2285, Disparlon LHP-810, Disparlon NSH-8430HF, Disparlon LHP-90, Disparlon LHP-91, Disparlon LHP-95, Disparlon LHP-96 (manufactured by Kusumoto Chemicals Co., Ltd.), etc. These may be used alone or in combination of two or more.

[0117] The polyaspartic coating composition of the present embodiment preferably further contains an antifoaming, foam suppressing, or defoaming agent as an additive, since this provides a better appearance when formed into a coating film. The type of antifoaming, foam suppressing, or defoaming agent is not particularly limited, and examples thereof include silicone-based and polymer-based agents. The content of the antifoaming, foam suppressing, and defoaming agent is preferably 0.05% by mass or more and 5% by mass or less based on the resin content of the polyaspartic paint composition. By having the content of the antifoaming, foam suppressing, and defoaming agent be equal to or more than the above lower limit, workability during blending and stirring can be improved, and the appearance of the resulting coating can be improved. On the other hand, by having the content of the antifoaming, foam suppressing, and defoaming agent be equal to or less than the above upper limit, the resulting coating can have better cissing resistance, recoatability, and stain resistance.

[0118] As the silicone-based defoaming / foam suppressing / defoaming agent, commercially available products can be used, such as BYK-063, BYK-065, BYK-066N, BYK-067A, BYK-077, BYK-081, BYK-1799 (manufactured by BYK Co., Ltd.); Disparlon 1930N, Disparlon 1934, Disparlon SPX-44 (manufactured by Kusumoto Chemicals Co., Ltd.); Tego Airex 900, Tego Airex 916, Tego Airex 931, Tego Airex 935, Tego Airex 962, Tego Airex 980, Tego Foamex N (manufactured by Evonic Tego Chemie Co., Ltd.). These may be used alone or in combination of two or more.

[0119] As the polymer-based defoaming / foam suppressing / defoaming agent, commercially available products can be used. For example, BYK-051N, BYK-052N, BYK-054, BYK-055, BYK-057, BYK-354, BYK-392, BYK-1752, BYK-1788, BYK-1790, BYK-1791, BYK-1794 (manufactured by BYK); Disparlon OX-60, Disparlon OX-6140, Disparlon OX-70, Disparlon OX-710, Disparlon OX-750HF, Disparlon OX-77EF, Disparlon OX-880 ... X-881, Disparlon OX-883HF, Disparlon LAP-10, Disparlon LAP-20, Disparlon LAP-30, Disparlon 1952, Disparlon 1958, Disparlon 1960, Disparlon P-410EF, Disparlon PD-7, Disparlon P-420, Disparlon P-450, Disparlon OX-881, Disparlon OX-883HF, Disparlon LAP-10, Disparlon P-425, Disparlon UVX-188, Disparlon UVX-189, Disparlon UVX-190 (manufactured by Kusumoto Chemicals); Tego Airex 910, Tego Airex 920, Tego Airex 936, Tego Airex 944, Tego Airex 955 (manufactured by Evonic Tego Chemie), and the like. These may be used alone or in combination of two or more.

[0120] As the other types of defoaming / foam suppressing / defoaming agents mentioned above, commercially available products can be used, for example, BYK-088, BYK-141 (manufactured by BYK), Disparlon OX-66EF, Disparlon OX-715 (manufactured by Kusumoto Chemicals), Tego Airex 940, Tego Airex 945, Tego Airex 950, Tego Airex 986 (manufactured by Evonic Tego Chemie), etc. These may be used alone or in combination of two or more.

[0121] <Method of manufacturing polyaspartic coating composition> The polyaspartic coating composition of this embodiment is obtained by mixing the above-mentioned aspartic acid ester compound (A) with a polyvalent active hydrogen compound and other components, if necessary, to obtain a mixture, and then blending the above-mentioned polyisocyanate compositions (B) and (C), which are curing agent components, into the mixture and mixing using a known method. At this time, a solvent may or may not be used. The polyaspartic coating composition of this embodiment can have a viscosity of 100 mPa·s or more and 12000 mPa·s or less, and can be produced while maintaining workability even in a solvent-free formulation. The usable time of the polyaspartic coating composition, measured as the time from preparation until the viscosity reaches 12000 mPa·s, is preferably 20 minutes or more, and more preferably 40 minutes or more.

[0122] <Application> The polyaspartic coating composition of the present embodiment is suitably used as a primer, intermediate coat or top coat on metals such as steel plates and surface-treated steel plates, plastics, inorganic materials such as ceramics, glass and concrete by roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, immersion, roller coating, brush coating or the like. The polyaspartic coating composition of the present embodiment is suitable for use in imparting cosmetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, adhesion, etc. to pre-coated metals including rust-resistant steel plates, painted parts of automobiles, painted parts of plastics, etc. The polyaspartic coating composition of the present embodiment is also useful as an adhesive, a pressure sensitive adhesive, an elastomer, a foam, a surface treatment agent, and the like.

[0123] <Coating film> The coating film of this embodiment is obtained by curing the above-mentioned polyaspartic coating composition. The coating film of this embodiment is excellent in appearance, chemical resistance, impact resistance, and scratch resistance. The coating film of this embodiment is obtained by applying the above-mentioned coating composition using a known method such as roll coating, curtain flow coating, spray coating, bell coating, electrostatic coating, etc., and curing it through a room temperature drying or baking process.

[0124] The coating film of this embodiment preferably has a tensile stress at break of 7 MPa or more, more preferably 30 MPa or more, even more preferably 40 MPa or more, and particularly preferably 50 MPa or more. The tensile breaking stress of the coating film can be measured, for example, by the method described in the examples below.

[0125] The coating film of this embodiment preferably has an elongation percentage of 40% or more, more preferably 60% or more, and particularly preferably 80% or more. The elongation of the coating film can be measured, for example, by the method described in the Examples below.

[0126] The coating film of this embodiment preferably has a Konig hardness of 40 or more, more preferably 45 or more, even more preferably 50 or more, and particularly preferably 55 or more. The Konig hardness of the coating film can be measured, for example, by the method described in the Examples below.

[0127] <Painted items> The coated article of the present embodiment includes the coating film described above. By including the coating film described above, the coated article of the present embodiment has excellent appearance, chemical resistance, impact resistance, and scratch resistance. EXAMPLES

[0128] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to the following examples. Various materials represented by the abbreviations shown in the Synthesis Examples, Examples, and Example Tables were prepared.

[0129] [Synthesis example] HDI: Hexamethylene diisocyanate

[0130] [Examples and Comparative Examples] (Aspartic acid ester compound (A)) A-1: Aspartic acid ester compound, product name "Feispartic F420" manufactured by Feiyang Co., Ltd., amine value 192 mg KOH / g resin, viscosity 1450 mPa·s (representative value measured at 25°C) A-2: Aspartic acid ester compound, product name "Feispartic F520" manufactured by Feiyang Co., Ltd., amine value 189 mg KOH / g resin, viscosity 1400 mPa·s (representative value measured at 25°C)

[0131] Tego wet 250: Silicone surface conditioner, manufactured by Evonik Tego Airex 944: Polymeric defoamer, manufactured by Evonik Moiecular sieves 4A-Powder: Dehydrating agent, manufactured by Union Showa Co., Ltd. Dimethyl adipate: Paint film modifier, manufactured by Tokyo Chemical Industry Co., Ltd. Dimethyl glutarate: Paint film modifier, manufactured by Tokyo Chemical Industry Co., Ltd.

[0132] (Polyisocyanates B-1 to B-4 and B'-1 to B'-4) [Synthesis Example 1] Production of Polyisocyanate B-1 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen and HDI: 1000g, 3 parts of 2-ethylhexanol and 1.5 parts of isobutanol were charged. The temperature inside the reactor was kept at 70°C while stirring, and tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added. When the yield reached 14.5%, phosphoric acid was added to stop the reaction. After heat treatment at 160°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B-1. The physical properties of the obtained B-1 are shown in Table 1.

[0133] [Synthesis Example 2] Production of Polyisocyanate B-2 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen, 1000g of HDI and 35 parts of 2-ethylhexanol were charged, the temperature inside the reactor was kept at 80°C while stirring, tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added, and when the yield reached 27%, phosphoric acid was added to stop the reaction. After heat treatment at 85°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B-2. The physical properties of the obtained B-2 are shown in Table 1.

[0134] [Synthesis Example 3] Production of Polyisocyanate B-3 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen, 1000g of HDI and 32 parts of 2-ethylhexanol were charged, the temperature inside the reactor was kept at 80°C while stirring, tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added, and when the yield reached 21%, phosphoric acid was added to stop the reaction. After heat treatment at 85°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B-3. The physical properties of the obtained B-3 are shown in Table 1.

[0135] [Synthesis Example 4] Production of Polyisocyanate B-4 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen, 1000g of HDI and 110 parts of 2-ethylhexanol were charged, and the temperature inside the reactor was kept at 80°C while stirring. Tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added, and when the yield reached 18%, phosphoric acid was added to stop the reaction. After heat treatment at 90°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B-4. The physical properties of the obtained B-4 are shown in Table 1.

[0136] [Synthesis Example 5] Production of Polyisocyanate B'-1 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet and dropping funnel was conditioned with nitrogen, 1000g of HDI was charged, the temperature inside the reactor was kept at 70°C while stirring, tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added, and when the yield reached 23%, phosphoric acid was added to stop the reaction. After heat treatment at 100°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B'-1. The physical properties of the obtained B'-1 are shown in Table 1. In Synthesis Examples 5 and 6 in Table 1, "none" in the column "molar ratio of allophanate groups / isocyanurate groups" means "no allophanate groups."

[0137] [Synthesis Example 6] Production of Polyisocyanate B'-2 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube, and dropping funnel was conditioned with nitrogen, 1000g of HDI was charged, and the temperature inside the reactor was kept at 70°C while stirring. Tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added, and when the yield reached 41%, phosphoric acid was added to stop the reaction. After heat treatment at 100°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B'-2. The physical properties of the obtained B'-2 are shown in Table 1.

[0138] [Synthesis Example 7] Production of Polyisocyanate B'-3 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen, 1000g of HDI and 80 parts of 2-ethylhexanol were charged, the temperature inside the reactor was kept at 130°C while stirring, 2-ethylhexanoic acid zirconyl, an allophanate reaction catalyst, was added, and when the yield reached 24%, phosphoric acid was added to stop the reaction. After heat treatment at 85°C, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B'-3. The physical properties of the obtained B'-3 are shown in Table 1.

[0139] [Synthesis Example 8] Production of Polyisocyanate B'-4 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet and dropping funnel was filled with nitrogen and charged with 1000g HDI and 18g 1,3-butylene glycol. The temperature inside the reactor was kept at 80°C while stirring, and tetramethylammonium caprylate, an isocyanurate reaction catalyst, was added. When the yield reached 41%, phosphoric acid was added to stop the reaction. After 85% heat treatment, the reaction liquid was filtered. Unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate B'-4. The physical properties of the obtained B'-4 are shown in Table 1.

[0140] (Polyisocyanates C-1, C-2 and C'-1 to C'-2) [Synthesis Example 9] Production of Polyisocyanate C-1 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen, 1000g of HDI and 340 parts of polycaprolactone polyol with a number average molecular weight of 850 were charged, and the temperature in the reactor was maintained under stirring until the yield reached 39%, and a urethane reaction was carried out. After filtering the cooled reaction liquid, unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate C-1. The physical properties of the obtained C-1 are shown in Table 2.

[0141] [Synthesis Example 10] Production of Polyisocyanate C-2 A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube and a dropping funnel was filled with nitrogen, 1000g of HDI, 72 parts of polycaprolactone polyol having a number average molecular weight of 550, and 127 parts of polytetramethylene glycol having a number average molecular weight of 1000 were charged, and the temperature inside the reactor was kept at 90°C for 120 minutes while stirring to carry out a urethane reaction. After filtering the cooled reaction liquid, unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate C-2. The physical properties of the obtained C-2 are shown in Table 2.

[0142] [Synthesis Example 11] Production of Polyisocyanate C'-1 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet and dropping funnel was filled with nitrogen, 1000g of HDI and 268g of polycaprolactone polyol with a number average molecular weight of 330 were charged, and the temperature inside the reactor was kept at 90°C for 120 minutes while stirring to carry out a urethane reaction. After filtering the cooled reaction liquid, unreacted HDI was removed using a thin-film evaporator to obtain polyisocyanate C'-1. The physical properties of the obtained C'-1 are shown in Table 2.

[0143] [Synthesis Example 12] Production of Polyisocyanate C'-2 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube and dropping funnel was filled with nitrogen, 1000g of HDI and 420g of polycaprolactone polyol with a number average molecular weight of 2000 were charged, and the temperature inside the reactor was kept at 90°C for 120 minutes while stirring to carry out a urethane reaction. After filtering the cooled reaction liquid, unreacted HDI was removed using a thin film evaporator to obtain polyisocyanate C'-2. The physical properties of the obtained C'-2 are shown in Table 2.

[0144] <Formulation of polyaspartic coating composition> [Example 1] Preparation of polyaspartic coating composition Pa-a1 A mixture was obtained by blending in advance the aspartic acid ester compound A-1, silicone-based surface conditioner, polymer-based defoamer, dehydrating agent, and modifier in the amounts shown in Table 3. The obtained mixture was blended with polyisocyanates B-1 and C-1 in the amounts shown in Table 3 so that the molar ratio of the amino groups of the aspartic acid ester compound (A) to the isocyanate groups of the polyisocyanate composition (B) and the polyisocyanate composition (C) was 1.1, to obtain a polyaspartic coating composition Pa-a1.

[0145] [Examples 2 to 19 and Comparative Examples 1 to 8] (Preparation of polyaspartic coating compositions Pa-a2 to Pa-a19 and Pa-b1 to Pa-b8) Each polyaspartic coating composition was prepared in the same manner as in Example 1, except that the ingredients were blended to obtain the compositions shown in Tables 3 to 8.

[0146] The methods for measuring various physical properties and the methods for evaluating various properties are explained below. Unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass".

[0147] <Method of measuring physical properties> [Physical Properties 1] The NCO content (isocyanate content, mass%) of the polyisocyanate compositions (B) and (C) was measured as follows. After weighing (Wg) 1 g or more and 3 g or less of the polyisocyanate composition (B) or (C) produced in the manufacturing example into an Erlenmeyer flask, 20 ml of toluene was added to completely dissolve the polyisocyanate composition (B). Then, 10 ml of a 2N toluene solution of di-n-butylamine was added, and after completely mixing, the mixture was left at room temperature for 15 minutes. Furthermore, 70 ml of isopropyl alcohol was added to this solution and completely mixed. This solution was titrated with a 1N hydrochloric acid solution (factor F) using an indicator to obtain a titration value V2 mL. A similar titration operation was performed without using polyisocyanate to obtain a titration value V1 mL. From the obtained titration values ​​V2 mL and V1 mL, the NCO content (mass%) of the polyisocyanate was calculated based on the following formula. (NCO content (mass%))=(V1-V2)×F×42 / (W×1000)×100

[0148] [Physical Properties 2] (Viscosity (mPa.s)) The viscosity of the polyisocyanate compositions (B) and (C) was measured at 25°C using an E-type viscometer (product name: RE-85R, manufactured by Toki Sangyo Co., Ltd.). A standard rotor (1°34'×R24) was used for the measurement. The rotation speed was set as follows: (Rotation Speed) 100 rpm (less than 128 mPa s) 50 rpm (128 mPa s or more but less than 256 mPa s) 20 rpm (256 mPa s or more but less than 640 mPa s) 10 rpm (640 mPa s or more but less than 1280 mPa s) 5 rpm (1280 mPa s or more but less than 2560 mPa s) 2.5 rpm (2560 mPa s or more but less than 5120 mPa s) 1.0 rpm (5120 mPa s or more but less than 10240 mPa s) 0.5 rpm (for values ​​between 10240 mPa s and 20480 mPa s)

[0149] [Physical Properties 3] (Weight average molecular weight and number average molecular weight) The weight average molecular weight and number average molecular weight of the polyisocyanate compositions (B) and (C) were determined based on polystyrene standards by gel permeation chromatography (hereinafter abbreviated as "GPC") using the following equipment. The measurement conditions are as follows. (Measurement conditions) Equipment: Tosoh Corporation "HLC-8120GPC" (product name) Column: Tosoh Corporation "TSKgel SuperH1000" (product name) x 1 "TSKgel SuperH2000" (product name) x 1 "TSKgel SuperH3000" (product name) x 1 Carrier: Tetrahydrofuran Detector: Differential refractometer

[0150] [Physical Properties 4] (average number of isocyanate groups) The average number of isocyanate groups in the polyisocyanate compositions (B) and (C) was calculated based on the following formula using the NCO content obtained in Property 1 and the number average molecular weight obtained in Property 3. (Average number of isocyanate groups) = (Number average molecular weight) × (NCO content) / 100 / 42

[0151] [Physical Properties 5] (Diisocyanate monomer mass concentration (mass%)) The diisocyanate mass concentration of the polyisocyanate compositions (B) and (C) was determined as follows. First, a 20 mL sample bottle was placed on a digital balance, and about 1 g of the sample was precisely weighed out. Next, 0.03 g to 0.04 g of nitrobenzene (internal standard solution) was added and precisely weighed out. Finally, about 9 mL of ethyl acetate was added, and the lid was firmly closed and mixed thoroughly to prepare the sample. The prepared sample was analyzed by gas chromatography under the following conditions, and quantified. (Measurement conditions) Equipment: “GC-8A” manufactured by SHIMADZU Column: "Silicone OV-17" manufactured by Shinwa Kako Co., Ltd. Column oven temperature: 120℃ Injection / detector temperature: 160℃

[0152] [Physical Properties 6] and [Physical Properties 7] (molar ratio of isocyanurate groups to total functional groups, molar ratio of allophanate groups to isocyanurate groups) The molar ratio of isocyanurate groups to the total functional groups, and the molar ratio of allophanate groups to isocyanurate groups in the polyisocyanate composition (B) were measured by 13C-NMR using Biospin Avance600 (trade name) manufactured by Bruker Corp. The specific measurement conditions were as follows: (Measurement conditions) 13C-NMR device: AVANCE600 (manufactured by Bruker) CryoProbe (manufactured by Bruker): CryoProbe (registered trademark) CPDUL600S3-C / HD-05Z Resonance frequency: 150MHz Concentration: 60wt / vol% Shift standard: CDCl3 (77 ppm) Accumulation count: 10,000 times Pulse program: zgpg30 (proton complete decoupling method, waiting time 2 sec)

[0153] The integral value of the following signals was divided by the number of carbons being measured to determine the molar ratios of allophanate groups and isocyanurate groups. Isocyanurate group: (integral value around 148.6 ppm) ÷ 3 Allophanate group: (integral value around 154 ppm) ÷ 1 Uretdione group: (integral value around 157 ppm) ÷ 2 Uretonemino group: (integral value around 159.5 ppm) ÷ 1 Urethane group: (integral value around 156.5 ppm) ÷ 1 Biuret group: (integral value around 156.2 ppm) ÷ 2 Urea group: (integral value around 157.8 ppm) ÷ 1 Iminooxadiazinedione group: (integral value around 135.5 ppm) ÷ 1

[0154] <Evaluation method> [Rating 1] (Pot Life) The viscosity of each polyaspartic coating composition 10 minutes after preparation was measured in the same manner as in Physical Properties 2 above, and the pot life was evaluated according to the following criteria. (Evaluation Criteria) ◎: Viscosity increase is less than 50% compared to the viscosity immediately after mixing ○: Viscosity increase is 50% or more but less than 100% compared to the viscosity immediately after mixing △: Viscosity increase of 100% or more but less than 200% compared to the viscosity immediately after mixing ×: Viscosity increased by 200% or more compared to the viscosity immediately after mixing

[0155] [Rating 2] (Possible usage time) The viscosity of each polyaspartic coating composition was measured every 5 minutes after preparation, and the usable life was evaluated according to the time it took for the viscosity to reach 12,000 mPa·s, using the following criteria: (Evaluation Criteria) ◎: Time required for viscosity to reach 12,000 mPa s is 40 minutes or more. ○: Time required for viscosity to reach 12,000 mPa s is 20 minutes or more but less than 40 minutes △: Time required for viscosity to reach 12,000 mPa s is 10 minutes or more but less than 20 minutes ×: Time required for viscosity to reach 12,000 mPa s is less than 10 minutes.

[0156] [Rating 3] (Coating appearance) Ten minutes after preparation, each polyaspartic coating composition was applied to a glass plate with an applicator so that the dry film thickness was 80 μm to 100 μm. After drying at 23° C. for one day, the coating appearance was evaluated visually according to the following criteria. (Evaluation Criteria) : The film is transparent and the fluorescent light transfer is clear. ○: The film is transparent and the fluorescent light transfer is slightly wavy. △: The film is slightly cloudy, and the fluorescent light transfer is slightly wavy. ×: The film is cloudy and the fluorescent light transfer is wavy.

[0157] [Rating 4] (Konig hardness) Each of the prepared polyaspartic coating compositions was applied to a glass plate with an applicator so that the dry film thickness was 80 μm to 100 μm. After drying at 23° C. for 7 days, the hardness was measured using a fully automatic pendulum hardness tester made by TQC Co., Ltd. and evaluated according to the following criteria. (Evaluation Criteria) ◎: 50 or more times ○: 45 or more, less than 50 times △: 40 times or more, 45 times or less ×: Less than 40 times

[0158] [Rating 5] (Adhesion) Each of the prepared polyaspartic coating compositions was applied to a mild steel plate with an applicator so that the dry film thickness was 80 μm to 100 μm. After drying at 23° C. for 7 days, the coating was evaluated according to JIS K5600-5-6 and the following criteria. (Evaluation Criteria) ◎: More than 90 out of 100 squares remain on the substrate. ○: Between 70 and 90 of 100 squares remain on the substrate. △: Between 50 and 70 of 100 squares remain on the substrate. ×: Less than 50 out of 100 squares remain on the substrate.

[0159] [Rating 6] (Alcohol resistance) Five minutes after preparation, each polyaspartic coating composition was applied to a glass plate with an applicator so that the dry film thickness was 80 μm to 100 μm. The coating was then dried at 23° C. for 7 days to obtain a cured coating. After that, a cotton ball soaked in an 80% aqueous ethanol solution was placed on the coating for 60 minutes, and the change in appearance of the coating was visually confirmed, and the chemical resistance was evaluated according to the following criteria. (Evaluation Criteria) ◎: No change in appearance of coating film ○: There is a slight change in the appearance of the coating film. △: Appearance of the coating has changed, with slight cracks and peeling of the coating. ×: Cracks and peeling occurred on the entire coating

[0160] [Rating 7] (acid resistance) Five minutes after preparation, each polyaspartic coating composition was applied to a glass plate with an applicator so that the dry film thickness was 80 μm to 100 μm. The composition was then dried at 23° C. for 7 days to obtain a cured coating film. After that, a cotton ball soaked in a 10% aqueous sulfuric acid solution was placed on the coating film for 24 hours, and the change in appearance of the coating film was visually observed, and the chemical resistance was evaluated according to the following criteria. (Evaluation Criteria) ◎: No change in appearance of coating film ○: There is a slight change in the appearance of the coating film. △: Appearance of the coating has changed, with slight cracks and peeling of the coating. ×: Cracks and peeling occurred on the entire coating

[0161] [Rating 8] (Breaking Stress) Each polyaspartic coating composition was applied to a glass plate with an applicator 5 minutes after preparation so that the dry film thickness was 80 μm or more and 100 μm or less. The coating was then dried at 23° C. for 7 days to obtain a cured coating film. Measurements were performed using a tensile tester (Shimadzu Corporation, AGS 500G) at a temperature of 23° C. and a humidity of 50% RH, with a tensile speed of 20 mm / min and a grip interval of 20 mm. (Evaluation Criteria) ◎: 50MPa or more ○: 40MPa or more, less than 50MPa △: 30MPa or more, less than 40MPa ×: Less than 30MPa

[0162] [Rating 9] (growth rate) Each polyaspartic coating composition was applied to a glass plate with an applicator 5 minutes after preparation so that the dry film thickness was 80 μm or more and 100 μm or less. The coating was then dried at 23° C. for 7 days to obtain a cured coating film. Measurements were performed using a tensile tester (Shimadzu Corporation, AGS 500G) at a temperature of 23° C. and a humidity of 50% RH, with a tensile speed of 20 mm / min and a grip interval of 20 mm. (Evaluation Criteria) ◎: 80% or more ○: 60% or more, less than 80% △: 40% or more, less than 60% ×: Less than 40%

[0163] [Table 1]

[0164] [Table 2]

[0165] [Table 3]

[0166] [Table 4]

[0167] [Table 5]

[0168] [Table 6]

[0169] [Table 7]

[0170] [Table 8]

[0171] In Examples 1 to 17, the resulting coating films maintained high hardness and chemical resistance, while exhibiting excellent flexibility and adhesion to the substrate.

[0172] Comparative Example 1 was poor in pot life, coating appearance, adhesion and elongation. Comparative Example 2 was poor in pot life, coating appearance and elongation. Comparative Example 3 was poor in adhesion and elongation. Comparative Example 4 was inferior in pot life, coating appearance, Konig hardness and breaking stress. Comparative Example 5 was poor in Konig hardness, alcohol resistance, acid resistance and breaking stress. Comparative Example 6 was inferior in pot life, coating appearance, Konig hardness and elongation. Comparative Example 7 was poor in adhesion, alcohol resistance and elongation. The coating film of Comparative Example 8 was poor in appearance, adhesion and alcohol resistance. [Industrial Applicability]

[0173] According to the present embodiment, it is possible to provide a polyaspartic coating composition and coating film that have excellent flexibility and adhesion to substrates while maintaining high hardness and chemical resistance of the resulting coating film.

Claims

1. The composition includes an aspartic acid ester compound (A), a first polyisocyanate composition (B), and a second polyisocyanate composition (C), a mass ratio of the second polyisocyanate composition (C) to the first polyisocyanate composition (B) is 5 / 95 to 95 / 5; The aspartic acid ester compound (A) is an aspartic acid ester compound represented by the following general formula (I): 【Chemistry 1】 (In general formula (I), X １１ is an n11-valent organic group obtained by removing the primary amino group of an n11-valent polyamine. １１ and R １２ are the same or different organic groups that are inactive to isocyanate groups under reaction conditions. n11 is an integer of 2 or more. The first polyisocyanate composition (B) is a polyisocyanate composition derived from an aliphatic diisocyanate and / or an alicyclic diisocyanate, Contains at least two or more of an isocyanurate group, an allophanate group, a uretdione group, a uretoneimino group, a urethane group, a biuret group, a urea group, and an iminooxadiazinedione group, B-a) containing 30% or more isocyanurate groups having a structure represented by the following general formula (II), when the sum of the number of moles of isocyanurate groups, allophanate groups, uretdione groups, uretonimino groups, urethane groups, biuret groups, urea groups, and iminooxadiazinedione groups is taken as 100%, 【Chemistry 2】 B-b) the molar ratio of the allophanate group derived from a monoalcohol having 1 to 20 carbon atoms to the isocyanurate group is 1 / 99 to 70 / 30; B-c) the weight average molecular weight is 500 or more and 1200 or less, and B-d) A polyisocyanate composition having a viscosity of 50 mPa·s or more and 1500 mPa·s or less at 25°C under a solvent-free condition, The second polyisocyanate composition (C) is a polyisocyanate composition derived from an aliphatic diisocyanate and / or an alicyclic diisocyanate and a polycaprolactone polyol having a number average molecular weight of 500 to 1,500, and has an isocyanate group content of 15 mass% or less.

2. The polyaspartic coating composition according to claim 1, wherein the average isocyanate functionality of each of the first polyisocyanate composition (B) and the second polyisocyanate composition (C) is 2.0 or more and 4.0 or less.

3. 3. The polyaspartic paint composition according to claim 1 or 2, wherein the molar ratio of the isocyanate groups of the first polyisocyanate composition (B) and the second polyisocyanate composition (C) to the amino groups of the aspartic acid ester compound (A) is 1 / 10 or more and 10 / 1 or less.

4. The polyaspartic coating composition according to claim 1 or 2, wherein the aliphatic diisocyanate and / or alicyclic diisocyanate of the first polyisocyanate composition (B) and the second polyisocyanate composition (C) comprises hexamethylene diisocyanate.

5. A coating film obtained by curing the polyaspartic coating composition according to claim 1 or 2.

6. A coating film obtained by curing the polyaspartic coating composition according to claim 1 or 2, which has a tensile breaking stress of 7 MPa or more and an elongation of 40% or more.

7. A coating film having a Konig hardness of 40 or more obtained by curing the polyaspartic coating composition according to claim 1 or 2.

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