Hardening components, hardening coatings (items)

Abstract

This curable composition comprises the following (A)-(E) components: (A) an organic solvent having an initial boiling point of 85-145ºC (exclusive of 145); (B) an organic solvent having an initial boiling point of 145-190ºC (exclusive of 190); (C) an organic solvent having an initial boiling point of 190-250ºC (exclusive of 250); (D) a polysilazane compound; and (E) a catalyst, wherein 12-85 mass% of the (A) component, 12-85 mass% of the (B) component, and 0.5-20 mass% of the (C) component are contained with respect to 100 mass% of the total of the (A) component, the (B) component, and the (C) component.　According to the present invention, provided is a curable composition having excellent drying properties, recovery workability after a certain period of time, and film water repellency.

Description

[Technical Field]

[0001] The present invention relates to a curable composition that exhibits excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating. [Background technology]

[0002] Conventionally, curable compositions have been applied to painted steel sheets of automobile bodies and other materials for the purpose of protection and improving aesthetics. For example, Japanese Patent Publication No. 2014-139301 discloses a curable composition with excellent water repellency, mainly composed of a polysilazane compound. [Overview of the Initiative]

[0003] However, the curable composition described in Japanese Patent Publication No. 2014-139301 had poor workability, such as drying too quickly after application, making it difficult to wipe off immediately. Furthermore, when applying such a curable composition, unevenness (areas with uneven thickness) may be discovered after a certain period of time has elapsed since the start of application. Therefore, in such cases, recovery work is often performed to adjust the thickness of the curable composition by wiping it with a microfiber or the like to remove the unevenness. Consequently, ease of recovery work (hereinafter also referred to as "recovery workability") is also required for the curable composition. Regarding these characteristics, the curable composition described in Japanese Patent Publication No. 2014-139301 has good recovery workability immediately after application, but after a certain period of time, the recovery workability deteriorates, making it difficult to wipe off. In addition, when forming a coating on the surface of painted steel plates of automobile bodies, etc., it is required to impart or improve water repellency, so good water repellency is also required for the cured coating (cured film).

[0004] The present invention has been made in view of the above circumstances, and aims to provide a curable composition that is excellent in drying properties, recovery workability after a certain period of time, and water repellency of the coating. Another object of the present invention is to provide a cured coating using the above curable composition. Furthermore, another object of the present invention is to provide an article equipped with the above cured coating.

[0005] As a result of diligent research to achieve the above objectives, the inventors have discovered a method for obtaining a curable composition that exhibits excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating, and have completed the present invention.

[0006] The gist of this invention is described below.

[0007] 1. Contains the following ingredients (A) to (E): A curable composition comprising 12 to 85% by mass of component (A), 12 to 85% by mass of component (B), and 0.5 to 20% by mass of component (C), based on a total of 100% by mass of components (A), (B), and (C): (A) Organic solvents with an initial boiling point of 85°C or higher and less than 145°C (B) Organic solvents with an initial boiling point of 145°C or higher and less than 190°C (C) Organic solvents with an initial boiling point of 190°C or higher and less than 250°C (D) Polysilazane compounds (E) Catalyst.

[0008] 2. The curable composition according to 1. above, wherein component (D) is an organic polysilazane compound or a polysiloxazane compound.

[0009] 3. The curable composition according to 1. or 2. above, wherein component (E) comprises at least one selected from the group consisting of organic titanium compounds, organic aluminum compounds, inorganic acid compounds, and organic base compounds.

[0010] 4. The curable composition according to any one of 1 to 3 above, wherein the total amount of components (A) to (C) is 10 to 800 parts by mass per 10 parts by mass of component (D).

[0011] 5. The curable composition according to any one of 1. to 4. above, wherein the component (C) contains at least one selected from the group consisting of isoparaffins having 14 to 18 carbon atoms and normal paraffins having 13 to 17 carbon atoms.

[0012] 6. The curable composition according to any one of 1. to 5. above, which is used for forming a coating film on the surface of a substrate selected from the group consisting of metal, glass, ceramics, plastic, fiber, steel sheet, and exterior steel sheet.

[0013] 7. The curable composition according to any one of 1. to 5. above, which is used as an antifouling coating agent.

[0014] 8. A cured coating film obtained by curing the curable composition according to any one of 1. to 5. above.

[0015] 9. An article having the cured coating film according to 8. above, which is an article selected from the group consisting of automobiles, motorcycles, bicycles, railway vehicles, solar panels, vending machines, and buildings.

Mode for Carrying Out the Invention

[0016] The details of the present invention will be described below. In this specification, "X to Y" is used in the sense of including the numerical values (X and Y) described before and after it as the lower limit value and the upper limit value, respectively, and means "X or more and Y or less". Further, concentration and % represent mass concentration and mass %, respectively, unless otherwise specified, and the ratio is a mass ratio unless otherwise specified. Further, unless otherwise specified, measurements of operations and physical properties are carried out under the conditions of room temperature (20 to 25°C) / relative humidity 40 to 55%RH. Further, "A and / or B" means including each of A and B and combinations thereof.

[0017] [Curable Composition] The curable composition according to one aspect of the present invention (hereinafter, also simply referred to as "curable composition") contains the following components (A) to (E). With respect to a total of 100% by mass of components (A), (B), and (C), it contains 12 to 85% by mass of component (A), 12 to 85% by mass of component (B), and 0.5 to 20% by mass of component (C) (however, the total of components (A), (B), and (C) is 100% by mass): (A) An organic solvent having an initial boiling point of 85°C or higher and lower than 145°C (B) An organic solvent having an initial boiling point of 145°C or higher and lower than 190°C (C) An organic solvent having an initial boiling point of 190°C or higher and lower than 250°C (D) A polysilazane compound (E) A catalyst.

[0018] That is, the curable composition contains components (A) to (E) described in detail below, and particularly contains components (A) to (C) in specific ratios. By having such a composition, the curable composition according to the present invention is excellent in drying property, recovery workability after a certain period of time, and water repellency of the film. In the present specification, "after a certain period of time" is not particularly limited, but means, for example, after 30 minutes. Also, "recovery workability after a certain period of time" is also simply described as "recovery workability".

[0019] <(A) component>

[0020] Hereinafter, each component contained in the curable composition will be described.

[0021] <(A) component> Component (A) contained in the curable composition of the present invention is an organic solvent having an initial boiling point of 85°C or higher and less than 145°C. In this specification, "organic solvent" means a liquid organic compound that can dissolve or uniformly disperse components (D) and (E) contained in the curable composition. In this specification, "liquid" means having fluidity at 25°C. More specifically, "liquid" means having a viscosity of 1,000 Pa·s or less as measured by a B-type viscometer at 25°C and atmospheric pressure. From the viewpoint of improving workability, the viscosity of the organic solvent is preferably 100 Pa·s or less, more preferably 1,000 mPa·s or less (1 Pa·s or less), and particularly preferably 150 mPa·s or less. On the other hand, the lower limit is not particularly limited, but is, for example, 0.1 mPa·s or more.

[0022] Furthermore, the content of component (A) in the curable composition is 12 to 85% by mass, when the total mass of components (A) to (C) is taken as 100% by mass. By setting the content of component (A) within the above predetermined range and combining it with the other components of the present invention (especially components (B) and (C)), a coating with excellent water repellency can be obtained. If the curable composition does not contain component (A), the water repellency of the coating decreases (see Comparative Example 4 below). Also, if the curable composition does not contain component (A) and contains an organic solvent having an initial boiling point lower than that of component (A) (i.e., less than 85°C), the recovery workability decreases (see Comparative Example 8 below).

[0023] The initial boiling point of component (A) is more preferably 90 to 140°C, particularly preferably 95 to 135°C, and most preferably 110 to 135°C.

[0024] Examples of organic solvents that can be used as component (A) include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents, but aliphatic hydrocarbon solvents are preferred. Furthermore, from the viewpoint of volatility and recovery workability, component (A) is preferably a petroleum hydrocarbon solvent having an initial boiling point within the above range and containing at least one aliphatic hydrocarbon selected from those having 6 to 10 carbon atoms.

[0025] The aliphatic hydrocarbon solvent that can be used as component (A) is not particularly limited, but examples include linear aliphatic hydrocarbons such as isoparaffins having 7 to 10 carbon atoms and normal paraffins having 6 to 9 carbon atoms; cyclic aliphatic hydrocarbons such as alkylcyclohexanes having 7 to 8 carbon atoms; or petroleum hydrocarbon solvents containing these. However, it is preferable to use linear aliphatic hydrocarbons or petroleum hydrocarbon solvents containing them as component (A). In particular, it is preferable that component (A) contains a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 7 to 10 carbon atoms and normal paraffins having 6 to 9 carbon atoms. More preferably, component (A) is a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 7 to 10 carbon atoms, and particularly preferably a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 8 to 9 carbon atoms.

[0026] Examples of component (A) include, more specifically, isooctane, isononane, or petroleum hydrocarbon solvents containing these. Component (A) is preferably a petroleum hydrocarbon solvent containing isooctane and / or isononane, and is particularly preferably a petroleum hydrocarbon solvent containing isononane. The organic solvent as component (A) may be used alone or in combination of multiple types. When two or more types are used in combination, the content of component (A) refers to the total amount.

[0027] (A) Examples of commercially available products of component (A) include Marcazole 8 (initial boiling point 97°C) (manufactured by Maruzen Petrochemical Co., Ltd.), Kyowazole® C-900 (initial boiling point 131°C) (manufactured by KH Neochem Co., Ltd.), and Isopar® C (initial boiling point 98°C) (manufactured by Standard Petroleum Osaka Sales Office Co., Ltd.).

[0028] The amount of component (A) added (content in the curable composition) is 12 to 85% by mass, preferably 16 to 80% by mass, and particularly preferably 20 to 70% by mass, based on 100% by mass of the total of components (A), (B), and (C). Within this range, a curable composition with excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained. Furthermore, the content of component (A) is preferably 80 to 350 parts by mass, more preferably 100 to 300 parts by mass, particularly preferably 120 to 250 parts by mass, and most preferably 130 to 230 parts by mass, relative to 10 parts by mass of component (D), which will be described later. Within this range, not only the desired effects can be obtained, but also adequate drying properties that allow application even in high-temperature (40°C) environments during the summer can be achieved.

[0029] <(B) component> Component (B) contained in the curable composition of the present invention is an organic solvent having an initial boiling point of 145°C or higher and less than 190°C. Furthermore, the content of component (B) in the curable composition is 12 to 85% by mass, when the total mass of components (A) to (C) is taken as 100% by mass. By setting the content of component (B) within the above predetermined range and combining it with the other components of the present invention (particularly components (A) and (C)), a curable composition with excellent recovery workability after a certain period of time can be obtained. If the curable composition does not contain component (B), the recovery workability decreases (see Comparative Examples 1 and 3 described later).

[0030] The initial boiling point of component (B) is more preferably 155 to 185°C, and particularly preferably 165 to 180°C.

[0031] Examples of organic solvents that can be used as component (B) include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents, but aliphatic hydrocarbon solvents are preferred. Furthermore, from the viewpoint of volatility and recovery workability, component (B) is preferably a petroleum hydrocarbon solvent that has an initial boiling point within the above range and contains at least one aliphatic hydrocarbon selected from those having 9 to 14 carbon atoms.

[0032] The aliphatic hydrocarbon solvent that can be used as component (B) is not particularly limited, but examples include linear aliphatic hydrocarbons such as isoparaffins having 10 to 14 carbon atoms and normal paraffins having 9 to 13 carbon atoms; cyclic aliphatic hydrocarbons such as alkylcyclohexanes having 7 to 12 carbon atoms; or petroleum hydrocarbon solvents containing these. However, it is preferable to use linear aliphatic hydrocarbons or petroleum hydrocarbon solvents containing them as component (B). In particular, it is preferable that component (B) be a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 10 to 14 carbon atoms and normal paraffins having 9 to 13 carbon atoms. More preferably, component (B) is a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 10 to 14 carbon atoms, and particularly preferably, a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 11 to 13 carbon atoms.

[0033] Examples of component (B) more specifically include isoundecane, isododecane, isotridecane, or petroleum hydrocarbon solvents containing these. Component (B) is preferably a petroleum hydrocarbon solvent containing at least one selected from the group consisting of isoundecane, isododecane, and isotridecane, more preferably a petroleum hydrocarbon solvent containing isoundecane and / or isododecane, and particularly preferably a petroleum hydrocarbon solvent containing isododecane. The organic solvent as component (B) may be used alone or in combination of multiple types. When two or more types are used in combination, the content of component (B) refers to the total amount.

[0034] (B) Examples of commercially available products of component (B) include 181 Solvent (initial boiling point 178°C) (manufactured by Daishin Chemical Co., Ltd.), Markazol R (initial boiling point 178°C) (manufactured by Maruzen Petrochemical Co., Ltd.), Isopar® G (initial boiling point 167°C), Isopar® H (initial boiling point 179°C), Norpar 10 (initial boiling point 169°C) (manufactured by Standard Petroleum Osaka Sales Office Co., Ltd.), and IP Solvent 1620 (initial boiling point 166°C) (manufactured by Idemitsu Kosan Co., Ltd.).

[0035] The amount of component (B) added (content in the curable composition) is 12 to 85% by mass, preferably 16 to 80% by mass, and particularly preferably 20 to 70% by mass, based on 100% by mass of the total of components (A), (B), and (C). Within this range, a curable composition with excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained. Furthermore, the content of component (B) is preferably 50 to 400 parts by mass, more preferably 60 to 320 parts by mass, and particularly preferably 70 to 300 parts by mass, relative to 10 parts by mass of component (D), which will be described later. Within this range, not only the desired effects can be obtained, but also adequate drying properties that allow application even in high-temperature (40°C) environments during the summer can be achieved.

[0036] <(C) component> Component (C) in the curable composition of the present invention is an organic solvent having an initial boiling point of 190°C or higher and less than 250°C. Furthermore, the content of component (C) in the curable composition is 0.5 to 20% by mass, when the total mass of components (A) to (C) is taken as 100% by mass. By setting the content of component (C) within the above predetermined range and combining it with the other components of the present invention (particularly components (A) and (B)), a curable composition with excellent drying properties and recovery workability after a certain period of time can be obtained. If the content of component (C) exceeds the above predetermined range, or if an organic solvent with an initial boiling point of 250°C or higher is included instead of component (C), the drying properties of the curable composition decrease (see Comparative Examples 5 and 7 below). Also, if component (C) is not included (i.e., an organic solvent with an initial boiling point of 190°C or higher is not included), the recovery workability decreases (see Comparative Examples 2 and 6 below).

[0037] The initial boiling point of component (C) is more preferably 200 to 240°C, and particularly preferably 210 to 230°C.

[0038] Organic solvents that can be used as component (C) include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents, but aliphatic hydrocarbon solvents are preferred. Furthermore, from the viewpoint of volatility and recovery workability, component (C) is preferably a petroleum hydrocarbon solvent that has an initial boiling point within the above range and contains at least one aliphatic hydrocarbon selected from those having 13 to 18 carbon atoms.

[0039] The aliphatic hydrocarbon solvent that can be used as component (C) is not particularly limited, but examples include linear aliphatic hydrocarbons such as isoparaffins having 14 to 18 carbon atoms, normal paraffins having 13 to 17 carbon atoms, or petroleum hydrocarbon solvents containing these. Component (C) is preferably a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 14 to 18 carbon atoms and normal paraffins having 13 to 17 carbon atoms, more preferably a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 14 to 18 carbon atoms, and particularly preferably a petroleum hydrocarbon solvent containing at least one selected from isoparaffins having 15 to 17 carbon atoms.

[0040] Examples of component (C) include, more specifically, isopentadecane, isohexadecane, isoheptadecane, or petroleum hydrocarbon solvents containing these. Component (C) is preferably a petroleum hydrocarbon solvent containing at least one selected from the group consisting of isopentadecane, isohexadecane, and isoheptadecane, and a petroleum hydrocarbon solvent containing isohexadecane is particularly preferred. The organic solvent as component (C) may be used alone or in combination of multiple types. When two or more types are used in combination, the content of component (C) refers to the total amount.

[0041] (C) Examples of commercially available products of component (C) include IP Solvent 2028 (initial boiling point 213°C) (manufactured by Idemitsu Kosan Co., Ltd.), MC531 (initial boiling point 220°C) (manufactured by Tobu Chemical Co., Ltd.), Norper 12 (initial boiling point 209°C), Norper 13 (initial boiling point 222°C) (manufactured by Standard Petroleum Osaka Sales Office Co., Ltd.), among which IP Solvent 2028 and MC531 are preferred.

[0042] The amount of component (C) added (content in the curable composition) is 0.5 to 20% by mass, preferably 1 to 15% by mass, particularly preferably 2 to 10% by mass, and most preferably 4 to 8% by mass, based on 100% by mass of the total of components (A), (B), and (C). Within this range, a curable composition with excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained. Furthermore, the content of component (C) is preferably 5 to 50 parts by mass, more preferably 7 to 40 parts by mass, and particularly preferably 10 to 30 parts by mass, relative to 10 parts by mass of component (D), which will be described later. Within this range, not only the desired effects can be obtained, but also adequate drying properties that allow application even in high-temperature (40°C) environments during the summer can be achieved.

[0043] Furthermore, the total amount of components (A) and (B) relative to 1 part by mass of component (C) is not particularly limited, but is, for example, 5 to 80 parts by mass, preferably 7 to 60 parts by mass, more preferably 10 to 45 parts by mass, particularly preferably 12 to 30 parts by mass, and most preferably 13 to 25 parts by mass. Within the above range, a curable composition with particularly excellent recovery workability after a certain period of time can be obtained.

[0044] Furthermore, the total amount of components (A) to (C) is not particularly limited, but is preferably 10 to 800 parts by mass, more preferably 75 to 700 parts by mass, more preferably 135 to 600 parts by mass, and particularly preferably 200 to 500 parts by mass, relative to 10 parts by mass of component (D) described later. Being within the above range further improves drying properties, recovery workability after a certain period of time (after 10 minutes or more), and water repellency of the coating.

[0045] The curable composition according to the present invention preferably contains only components (A) to (C) as organic solvents. That is, the curable composition according to the present invention preferably substantially contains no organic solvents other than components (A) to (C). Here, "substantially contains no organic solvents other than components (A) to (C)" means that the content of organic solvents other than components (A) to (C) relative to the total amount of organic solvents contained in the curable composition is less than 0.01% by mass. That is, in one embodiment of the present invention, the content of organic solvents other than components (A) to (C) is less than 0.01% by mass (lower limit: 0% by mass), with the total mass of organic solvents contained in the curable composition being 100% by mass.

[0046] <(D) component> Component (D) in the curable composition of the present invention is a polysilazane compound. By combining component (D) with other components of the present invention, a curable composition with excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained. Component (D) is not particularly limited as long as it is a compound having multiple Si-N bonds. It is generally known that such polysilazane compounds undergo hydrolysis reactions with moisture present in the air, where nitrogen is removed from the molecule to produce ammonia, which acts as a catalyst to further promote the reaction and form Si-O bonds three-dimensionally.

[0047] Component (D) is not particularly limited, but examples include organic polysilazane compounds, inorganic polysilazane compounds, and polysiloxazane compounds. In particular, since a curable composition with even better drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained, component (D) is preferably an organic polysilazane compound or a polysiloxazane compound, and more preferably an organic polysilazane compound.

[0048] In this specification, "organic polysilazane compound" and "inorganic polysilazane compound" refer to a compound in which the main chain of the molecule contains "-(SiR 1 R 2 -NR 3 It has a repeating structure represented by "-(SiR 4 R 5It means a compound having no repeating structure represented by "-O)-". Also, in this specification, the "polysiloxazane compound" means a compound having both a repeating structure represented by "-(SiR 1 R 2 -NR 3 )-" and a repeating structure represented by "-(SiR 4 R 5 -O)-" in the main chain of the molecule.

[0049] In the above formula, R 1 , R 2 and R 3 each independently represent an organic group selected from a hydrogen atom and a hydrocarbon group which may have a substituent. Also, in the above formula, R 4 and R 5 each independently represent a linear or branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0050] Note that when simply described as "polysilazane compound", this term refers to a compound having a plurality of Si-N bonds in the main chain regardless of the presence or absence of Si-O bonds, and includes "polysiloxazane compound". However, in this specification, in order to distinguish it from "polysiloxazane compound", a compound having no Si-O bond but having a Si-N bond in the main chain is referred to as "organic polysilazane compound" or "inorganic polysilazane compound".

[0051] The above R 1 , R 2 and R 3 are each independently preferably an organic group selected from a hydrogen atom and a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and more preferably an organic group selected from a hydrogen atom and an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

[0052] Examples of hydrocarbon groups having 1 to 6 carbon atoms include saturated aliphatic hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, 3-methylpentyl, and ethylbutyl groups; unsaturated aliphatic hydrocarbon groups such as vinyl, allyl, isopropenyl, 2-butenyl, 2-methylallyl, 4-pentenyl, and hexenyl groups; alicyclic hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups; and aromatic hydrocarbon groups such as phenyl groups.

[0053] Furthermore, examples of aliphatic hydrocarbon groups having 1 to 4 carbon atoms include those among the saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, and alicyclic hydrocarbon groups that have 1 to 4 carbon atoms.

[0054] The substituents that can substitute for the hydrocarbon group are not particularly limited, but examples include halogen atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as methyl and ethyl groups; aryl groups such as phenyl, p-tolyl, xylyl, and naphthyl groups; alkoxy groups such as methoxy, ethoxy, and tert-butoxy groups; aryloxy groups such as phenoxy and p-tolyloxy groups; alkoxycarbonyl groups such as methoxycarbonyl, butoxycarbonyl, 2-ethylhexyloxycarbonyl, and phenoxycarbonyl groups; acetoxy, propionyloxy, and benzoyl groups. Examples of hydrocarbon groups include acyloxy groups such as oxy groups; acyl groups such as acetyl groups, benzoyl groups, isobutyryl groups, acryloyl groups, and methacryloyl groups; alkylamino groups such as methylamino groups and cyclohexylamino groups; dialkylamino groups such as dimethylamino groups, diethylamino groups, morpholino groups, and piperidino groups; arylamino groups such as phenylamino groups and p-tolylamino groups; and others such as hydroxyl groups, carboxyl groups, formyl groups, mercapto groups, sulfo groups, amino groups, nitro groups, cyano groups, trifluoromethyl groups, trichloromethyl groups, trimethylsilyl groups, and phosphono groups. However, the hydrocarbon groups listed above cannot be the same as the substituents they are substituted with. For example, if the hydrocarbon group is an alkyl group, it cannot be substituted with an alkyl group.

[0055] Here, within the main chain of the molecule, there is "-(SiR 1 R 2 -NR 3 It has a repeating structure represented by "-" and "-(SiR 4 R 5 For compounds that do not have a repeating structure represented by -O)-, in the above formula R 1 , R 2 and R 3 A compound in which all atoms are hydrogen atoms is called an "inorganic polysilazane compound," and R 1 , R 2 and R 3 Of these, those in which at least one is an organic group are called "organopolysilazane compounds."

[0056] The polysilazane compound as component (D) (preferably an organic polysilazane compound, an inorganic polysilazane compound, and a polysiloxazane compound) may be used alone or in combination of multiple types. When two or more types are used in combination, the content of component (D) refers to the total amount.

[0057] As commercially available products of component (D) of the present invention, organic polysilazane compounds such as KiON HTA1500 rapid cure, KiON HTA1500 slow cure, KiON HTT1800 slow cure, tutoProm® matt HD, tutoProm® bright G, and CAG 37 (manufactured by AZ Material Co., Ltd.) can be used. As inorganic polysilazane compounds, examples include Aquamica® NP110-20 and Aquamica® NP140-2 (manufactured by AZ Material Co., Ltd.). Polysiloxazane compounds can be obtained by manufacturing methods disclosed in Japanese Patent Publication No. 62-195024, Japanese Patent Publication No. 2004-532318, Japanese Patent Publication No. 2020-122033, and Japanese Patent Publication No. 2021-055052.

[0058] The amount of component (D) added to the curable composition according to the present invention (content in the curable composition) is not particularly limited, but is preferably 0.5 to 10 parts by mass, more preferably 1.0 to 8 parts by mass, and particularly preferably 1.5 to 5 parts by mass, based on 100 parts by mass of the total of components (A) to (C). Within the above range, a curable composition with even greater drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained.

[0059] <(E) component> Component (E) in the curable composition of the present invention is a catalyst. When the curable composition contains component (E), the Si-N bond, which is a hydrolyzable functional group contained in component (D), reacts with moisture in the air, etc., to promote a condensation reaction and form a cured film.

[0060] Examples of component (E) include organotin compounds, organotitanium compounds, organoaluminum compounds, organozinc compounds, organozirconium compounds, inorganic acid compounds, organic acid compounds, inorganic base compounds, and organic base compounds. In particular, component (E) preferably contains at least one selected from the group consisting of organotitanium compounds, organoaluminum compounds, inorganic acid compounds, and organic base compounds, more preferably contains at least one selected from the group consisting of organotitanium compounds and organoaluminum compounds, and particularly preferably contains an organotitanium compound, as it is compatible with component (D) above and yields a curable composition with excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating. These may be used individually or in combination of multiple types.

[0061] Examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, dioctyltin dilaurate, dioctyltin dioctate, dioctyltin diacetate, dibutyltin bisacetylacetate, and dioctyltin bisacetyllaurate. Examples of organotitanium compounds include titanium chelate compounds such as titanium acetylacetonate, titanium-1,3-propanedioxybis(ethylacetoacetate), and titanium ethylacetoacetate; and titanium alkoxide compounds such as tert-amyl titanate, tetratert-butyl titanate, tetrastearyl titanate, tetraoctyl titanate, tetran-butyl titanate, and tetraisopropyl titanate. Furthermore, organoaluminum compounds include aluminum methoxybis(ethyl acetate), aluminum methoxybis(acetylacetonate), aluminum ethoxybis(ethyl acetate), aluminum ethoxybis(acetylacetonate), aluminum isopropoxybis(ethyl acetate), aluminum isopropoxybis(methyl acetate), aluminum isopropoxybis(tert-butyl acetate), aluminum butoxybis(ethyl acetate), aluminum dimethoxy(ethyl acetate), and aluminum dimethoxy(acetylacetonate). Examples of aluminum chelate compounds include aluminum diethoxy(ethyl acetate), aluminum diethoxy(acetylacetonate), aluminum diisopropoxy(ethyl acetate), aluminum diisopropoxy(methyl acetate), aluminum tris(ethyl acetate), and aluminum tris(acetylacetonate); aluminum alkoxide compounds such as aluminum trimethoxide, aluminum triethoxide, aluminum triallyl oxide, and aluminum triphenoxide; aluminum trihydroxy; and aluminosiloxy compounds. Examples of organozinc compounds include zinc octoate, zinc 2-ethylhexanoate, zinc triacetylacetonate, zinc-2-ethylhexoate, zinc naphthenate, and zinc stearate.Examples of organozirconium compounds include zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium dibutoxydiacetylacetonate, zirconium tetran-n-propoxide, zirconium tetraisopropoxide, zirconium tetran-n-butoxide, zirconium acylate, zirconium tributoxystearate, zirconium octoate, zirconyl (2-ethylhexanoate), zirconium (2-ethylhexoate), and others.

[0062] Examples of inorganic acid compounds include hydrochloric acid, phosphoric acid, sulfuric acid, and hydrofluoric acid. Examples of organic acid compounds include p-toluenesulfonic acid, oxalic acid, citric acid, and acetic acid. Examples of inorganic base compounds include ammonia, sodium hydroxide, and magnesium hydroxide. Examples of organic base compounds include trimethylamine, triethylamine, tributylamine, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU).

[0063] The above catalysts may be used individually or in combination of multiple types. When two or more types are used in combination, the content of component (E) refers to the total amount.

[0064] Examples of commercially available organotitanium compounds include Orgatics® TA-8, TA-21, TA-23, TA-30, TC-100, TC-401, TC-710 (manufactured by Matsumoto Fine Chemical Co., Ltd.), D-20, D-25, and DX-175 (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of commercially available organoaluminum compounds include DX-9740 and CAT-AC (manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of commercially available inorganic acid compounds include D-220 and X-40-2309A (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0065] The amount of component (E) added (content in the curable composition) is not particularly limited, but for example, it is preferably 0.01 to 50 parts by mass of component (E) per 100 parts by mass of component (D), more preferably 0.03 to 30 parts by mass, particularly preferably 0.5 to 10 parts by mass, and most preferably 1 to 8 parts by mass. Within the above range, a curable composition with even better drying properties, recovery workability after a certain period of time, and water repellency of the coating can be obtained.

[0066] <Optional ingredients> The curable composition according to the present invention may contain any additive components as appropriate, as long as they do not impair its properties. For example, components such as silicone compounds, silane compounds, fillers, antioxidants, rust inhibitors, fungicides, colorants, surfactants, rheology modifiers, UV absorbers, fluorescent agents, abrasives, fragrances, and fillers can be selected.

[0067] [Method for forming a cured coating and the cured coating itself] The method for forming a cured film according to the present invention (method for forming a film of a curable composition) is not particularly limited, but examples include the following methods.

[0068] First, an appropriate amount of the curable composition according to the present invention is impregnated into a brush, sponge, nonwoven fabric, microfiber cloth, etc., and then spread onto the substrate surface by hand (coating step). Nonwoven fabric refers to a cloth in which fibers are intertwined without weaving, and microfiber cloth refers to a cloth woven with extremely fine chemical fibers.

[0069] Next, the reaction of component (D) is promoted by component (E), thereby forming a film of the curable composition (cured film) (reaction step). That is, another aspect of the present invention provides a method for forming a cured film, which includes applying the above-mentioned curable composition to a substrate surface and curing it on the substrate surface.

[0070] Furthermore, it is preferable to impregnate a brush, sponge, nonwoven fabric, or fiber (such as a microfiber cloth) with an appropriate amount of the curable composition according to the present invention, spread it on the substrate surface by hand (after the coating step), and then allow components (A) to (C) to volatilize by natural drying, drying in a dryer, or the like (drying step). In other words, a method for forming a cured film according to another embodiment of the present invention preferably further includes, after applying the curable composition to the substrate surface, drying (volatilizing) components (A) to (C) contained in the curable composition on the substrate surface.

[0071] While there are no particular restrictions on drying conditions, examples include 5-50°C and 5-60 minutes. The curable composition of the present invention has the advantage of being able to be applied over a wide drying temperature range as described above.

[0072] Furthermore, a method for forming a cured film according to another embodiment of the present invention preferably further includes a finishing step of wiping off any excess curable composition after the coating or drying step. The method for forming a cured film according to the present invention has the advantage that the thickness of the curable composition can be easily adjusted and unevenness removed in such a finishing step. In other words, it has excellent recovery workability. The finishing step can be performed using a dry cloth, microfiber cloth, or the like.

[0073] Furthermore, according to another aspect of the present invention, a cured film is provided obtained by curing the curable composition. The cured film formed using the curable composition exhibits excellent water repellency.

[0074] The thickness of the coating (cured film) of the curable composition of the present invention is not particularly limited, but is, for example, 0.01 to 500 μm, preferably in the range of 0.1 to 300 μm, and more preferably in the range of 0.5 to 100 μm. By setting the thickness of the coating of the curable composition within the above range, good water repellency can be maintained. Therefore, in the coating step of the method for forming a cured film according to the present invention, it is preferable to appropriately adjust the thickness of the coating so that the thickness of the film when dry is within the above range.

[0075] Examples of the substrate include metal, glass, ceramics, plastic, and fiber, with metal, glass, and plastic being preferred. Specifically, the metal may be a metal member in the shape of a rod, sphere, or plate. Furthermore, the metal may specifically be a steel plate (unpainted metal steel plate) or an exterior steel plate (painted steel plate). The curable composition of the present invention is suitably used for forming a film on the surface of a substrate selected from the group consisting of metal, glass, ceramics, plastic, fiber, steel plate, and exterior steel plate. More preferably, the curable composition of the present invention is used to form a film on the surface of a substrate selected from the group consisting of plastic, steel plate, and exterior steel plate.

[0076] Examples of the aforementioned plastics include (meth)acrylic resin, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyethylene naphthalate, acrylonitrile-butadiene-styrene resin, styrene-methacrylic resin, polystyrene, polyethylene, polypropylene, polyvinyl chloride, polyester, and polyurethane. In this specification, the term "(meth)acrylic" includes both acrylic and methacrylic.

[0077] Of these, the curable composition of the present invention is preferred from the viewpoint of being able to form a cured film with excellent adhesion to steel plates (unpainted metal steel plates), painted steel plates, (meth)acrylic resin, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyethylene, polypropylene, styrene-methacrylic resin, etc.

[0078] [Application] The main applications of the curable composition according to the present invention include, for example, its use as an antifouling coating agent. Specifically, it can be used as an antifouling coating agent for automobiles, motorcycles, bicycles, construction machinery, agricultural machinery, aircraft, railway vehicles, ships, roofs and exterior walls of buildings, windows, bridge girders and other buildings, road traffic signs, traffic lights, billboards, vending machines, solar panels and other items that are installed outdoors for long periods of time; and as an antifouling coating agent for the exteriors of equipment and parts. In particular, it is suitably used as an antifouling coating agent for automobiles, motorcycles, bicycles, construction machinery, agricultural machinery, aircraft, railway vehicles, ships, buildings, vending machines and solar panels, and is especially preferred as an antifouling coating agent for bicycles. As an antifouling coating agent for automobiles, for example, it can be used as an antifouling coating agent for vehicles, headlamps, aluminum wheels, seats and interior parts.

[0079] [Goods] Furthermore, according to another aspect of the present invention, articles having a cured coating obtained by curing the curable composition are also provided. Examples of such articles include automobiles, motorcycles, bicycles, railway vehicles, solar panels, vending machines, and buildings. That is, another aspect of the present invention also provides articles having the above-mentioned cured coating, the articles being selected from the group consisting of automobiles, motorcycles, bicycles, railway vehicles, solar panels, vending machines, and buildings. [Examples]

[0080] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, operations and tests were carried out in an environment of 23°C and 50% RH. Furthermore, unless otherwise specified, concentration and % represent mass concentration and mass % respectively, and ratios represent mass ratios unless otherwise specified.

[0081] [Preparation of curable compositions] Each component was weighed to achieve the composition shown in Table 1 (unit: parts by mass), and mixed in a mixer at room temperature for 60 minutes to obtain a curable composition. The detailed amounts (contents) of each component are as shown in Table 1, and the units of the values ​​in Table 1 are "parts by mass" unless otherwise specified. The item "((A) component + (B) component) / (C) component" represents the total amount of (A) component and (B) component per 1 part by mass of (C) component (unit: parts by mass). Blank spaces and "0" in Table 1 indicate that the corresponding component is not included.

[0082] <(A) Component and comparative component> a1: An isoparaffinic solvent containing isononane with an initial boiling point of 131°C (Kyowazol® C-900, manufactured by KH Neochem Co., Ltd.) a'1: An isoparaffinic solvent containing isohexane with an initial boiling point of 61°C (isohexane manufactured by Maruzen Petrochemical Co., Ltd.) <(B) component> b1: An isoparaffinic solvent containing isododecane (2,2,4,6,6-pentamethylheptane) with an initial boiling point of 178°C (Marukazol R, manufactured by Maruzen Petrochemical Co., Ltd.) <(C) Components and comparative components> c1: An isoparaffinic solvent containing isohexadecane with an initial boiling point of 213°C (IP Solvent 2028, manufactured by Idemitsu Kosan Co., Ltd.) c'1: Isoparaffinic solvent with an initial boiling point of 185°C (Isopar® L, manufactured by Standard Oil Co., Ltd. Osaka Sales Office) c'2: Isoparaffinic solvent with an initial boiling point of 270°C (Isopar® V, manufactured by Standard Oil Co., Ltd. Osaka Sales Office) <(D) component> d1: 100% active ingredient, an organic polysilazane compound (KiON HTA1500 rapid cure, manufactured by AZ Material Co., Ltd.) d2: 100% active ingredient, an organic polysilazane compound (KiON HTA1500 slow cure, manufactured by AZ Material Co., Ltd.) <(E) component> e1: Organotitanium compound (titanium alkoxide compound; D-25, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0083] [evaluation] The tests and evaluations were conducted under the following conditions.

[0084] <(1)Drying property> Approximately 2 mL of each curable composition was impregnated into a nonwoven fabric. Test specimens were prepared by thinly applying the curable composition by hand to the entire black painted surface of a black painted board (material: SPCC-SD, dimensions: 0.8 mm × 70 mm × 150 mm, manufactured by Asahi B-Techno Co., Ltd.) using the nonwoven fabric. The drying time was measured at an arbitrary point on the coated surface of the test specimen using a method conforming to the JIS K 5600-3-3:1999 touch-dry test. After applying the curable composition, measurements were taken every 15 seconds for 5 minutes at 25°C and in a windless environment, and thereafter every 5 minutes for 90 minutes. The drying properties were evaluated based on the following criteria. The presence or absence of tackiness was confirmed by touch. The results are shown in Table 1. In this invention, × indicates that the drying time is too long or too short, resulting in poor workability (workability) and is therefore undesirable, while ○ indicates that the balance between pot life during application and drying properties is favorable.

[0085] Evaluation Criteria ○: Products with a touch-dry time of 5 minutes to 60 minutes. ×: Products with a touch-dry time of less than 5 minutes or more than 60 minutes.

[0086] <(2) Recovery workability after a certain period of time has elapsed> Each curable composition was thoroughly soaked into a nonwoven fabric and thinly spread by hand onto the surface of a black painted board (material: SPCC-SD, dimensions: 0.8mm x 70mm x 150mm, manufactured by Asahi B-Techno Co., Ltd.). Next, after 30 minutes at 25°C and in a windless environment, the curable composition was wiped off with a dry microfiber cloth, and the recovery workability after 30 minutes was evaluated based on the following criteria. The results are shown in Table 1. Unevenness was checked visually. In this invention, it is preferable that the workability for recovery after a certain period of time is ○ or ◎.

[0087] Evaluation Criteria ◎: It was possible to wipe evenly without leaving any streaks, and the smoothness during wiping made the work process easy. ○: Although it was possible to wipe it evenly, the wiper was not very smooth and snagged during wiping, making the workability somewhat inferior. ×: Unevenness remained. Alternatively, the surface was not smooth and snagged during wiping, resulting in extremely poor workability.

[0088] <(3) Water repellency> Each curable composition was thoroughly impregnated into a nonwoven fabric and thinly spread by hand onto the surface of a black painted board (material: SPCC-SD, dimensions: 0.8 mm x 70 mm x 150 mm, manufactured by Asahi B-Techno Co., Ltd.). After 10 minutes, the excess was wiped off with a dry microfiber cloth, and the board was left to cure for 168 hours at 25°C and 55% RH to prepare test specimens. Next, one drop (0.005 ml) of deionized water was dropped onto the surface of each test specimen using a dropper, and the contact angle of the water with respect to the substrate surface was measured using a contact angle meter (DM-500, manufactured by Kyowa Interface Science Co., Ltd.) to evaluate the water contact angle. The results are shown in Table 1. In this invention, water repellency is preferably indicated by ○.

[0089] Evaluation Criteria ○: Water contact angle is 100 degrees or more ×: The water contact angle is less than 100 degrees.

[0090] [Table 1] Examples 1 to 8 in Table 1 demonstrate curable compositions with excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating.

[0091] Furthermore, Comparative Example 1 in Table 1 is a curable composition that does not contain components (B) and (C), but it showed poor drying properties and recovery workability after a certain period of time. Furthermore, Comparative Example 2 is a curable composition that does not contain component (C), but it showed poor recovery workability after a certain period of time. Furthermore, Comparative Example 3 is a curable composition that does not contain component (B), but it showed poor recovery workability after a certain period of time. Furthermore, Comparative Example 4 is a curable composition that does not contain component (A), but it showed poor water repellency. Furthermore, Comparative Example 5 is a curable composition that contains an excess amount of component (C) (26.7% by mass of (((A) component + (B) component + (C) component)) compared to the scope of the present invention, but it showed poor drying properties and water repellency. Furthermore, Comparative Example 6 is a curable composition that contains component c'1 (an organic solvent with a lower initial boiling point than component (C)) instead of component (C), but it showed poor recovery workability after a certain period of time. Comparative Example 7 is a curable composition containing component c'2 (an organic solvent with a higher initial boiling point than component (C)) instead of component (C), but it showed inferior drying properties and water repellency. Comparative Example 8 is a curable composition containing component a'1 (an organic solvent with a lower initial boiling point than component (A)) instead of component (A), but it showed inferior recovery workability after a certain period of time. [Industrial applicability]

[0092] The present invention provides a curable composition that exhibits excellent drying properties, recovery workability after a certain period of time, and water repellency of the coating. Since this curable composition can be used as a coating agent in automobiles and the like, it is industrially useful.

[0093] This application is based on Japanese Patent Application No. 2021-113997, filed on July 9, 2021, and its disclosures are referenced and incorporated as a whole.

Claims

1. It contains the following components (A) to (E): A curable composition comprising 12 to 85% by mass of component (A), 12 to 85% by mass of component (B), and 0.5 to 20% by mass of component (C), based on a total of 100% by mass of components (A), (B), and (C): (A) Organic solvents with an initial boiling point of 85°C or higher and less than 145°C (B) Organic solvents having an initial boiling point of 145°C or higher and less than 190°C (C) Organic solvents having an initial boiling point of 190°C or higher and less than 250°C (D) Polysilazane compounds (E) Catalyst, Here, the initial boiling point is the value measured by the atmospheric pressure distillation method described in JIS K 0066:1992 (Distillation Test Method for Chemical Products). The content of organic solvents other than components (A) to (C) relative to the total amount of organic solvents contained in the curable composition is less than 0.01% by mass.

2. The curable composition according to claim 1, wherein the (D) component is an organic polysilazane compound or a polysiloxazane compound.

3. The curable composition according to claim 1, wherein the (E) component comprises at least one selected from the group consisting of organic titanium compounds, organic aluminum compounds, inorganic acid compounds, and organic base compounds.

4. The curable composition according to claim 1, wherein the total amount of components (A) to (C) is 10 to 800 parts by mass with respect to 10 parts by mass of component (D).

5. The curable composition according to claim 1, wherein component (C) comprises at least one selected from the group consisting of isoparaffins having 14 to 18 carbon atoms and normal paraffins having 13 to 17 carbon atoms.

6. The curable composition according to claim 1, used for forming a coating on the surface of a substrate selected from the group consisting of metals, glass, ceramics, plastics, fibers, steel sheets, and exterior steel sheets.

7. A curable composition according to claim 1, used as an antifouling coating agent.

8. A cured coating obtained by curing the curable composition described in claim 1.

9. An article having a cured coating as described in claim 8, Articles selected from the group consisting of automobiles, motorcycles, bicycles, railway vehicles, solar panels, vending machines, and buildings.

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