Paint additives and paint compositions

Abstract

To provide an additive for a coating which can suppress deterioration with time when a coating composition is applied to an outdoor structure to form a coating film.SOLUTION: There is provided an additive for coating which comprises at least one selected from the group consisting of hydrogenated naphtha (A1) having a kinematic viscosity at 40°C of 30 cSt or less, a naphthenic mineral oil (A2) having a kinematic viscosity at 40°C of 30 cSt or less, a poly-α-olefin (A3) having a kinematic viscosity at 100°C of 4 cSt or less and an organic solvent (A4) having a boiling point of 100°C or less as liquid components and a neutral phosphite ester derivative represented by the following formula (B) as an additive.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a paint additive and a paint composition. [Background technology]

[0002] Patent Document 1 describes a solvent-based heat-shielding functional film that is formed on the roof or exterior walls of a building, etc. The solvent-based heat-shielding functional film is formed by applying and curing a solvent-based paint composition in which spherical metal oxide particles are blended with a solvent-based paint, and is characterized in that when the coating is formed, the spherical metal oxide particles are unevenly distributed and dispersed on the film surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-160115 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the solvent-based heat-shielding functional film of Patent Document 1 has the problem that it deteriorates rapidly over time when exposed to sunlight.

[0005] Therefore, an object of the present invention is to provide a paint additive that can suppress deterioration over time when a paint composition is applied to an outdoor structure to form a paint film. [Means for solving the problem]

[0006] The paint additive of the present invention contains, as a liquid component, at least one selected from the group consisting of hydrotreated naphtha (A1) having a kinematic viscosity at 40°C of 30 cSt or less, naphthenic mineral oil (A2) having a kinematic viscosity at 40°C of 30 cSt or less, polyalphaolefin (A3) having a kinematic viscosity at 100°C of 4 cSt or less, and organic solvent (A4) having a boiling point of 100°C or less, and a neutral phosphite ester derivative represented by the following formula (B) as an additive:

[0007] [ka]

[0008] In the above formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, and R b25 ~R b28 each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms; R b291 and R b292 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms; R b291 and R b292 The total number of carbon atoms is 1 to 5. [Effects of the Invention]

[0009] According to the paint additive of the present invention, when a paint composition containing the same is applied to an outdoor structure to form a paint film, deterioration over time can be suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0010] Modes (embodiments) for carrying out the present invention will be described in detail. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0011] [Paint additives] The paint additive (composition) of the embodiment includes a liquid component and an additive.

[0012] The liquid component is at least one selected from the group consisting of hydrotreated naphtha (A1) having a kinematic viscosity (JIS K 2283) at 40°C of 30 cSt or less, naphthenic mineral oil (A2) having a kinematic viscosity (JIS K 2283) at 40°C of 30 cSt or less, polyalphaolefin (A3) having a kinematic viscosity (JIS K 2283) at 100°C of 4 cSt or less, and organic solvent (A4) having a boiling point of 100°C or less. The liquid components may be used alone or in combination of two or more. The naphtha (A1) preferably has a kinematic viscosity at 40°C of 1 cSt or more. Furthermore, the naphtha (A1) has a low molecular weight and is characterized by its ability to easily dissolve organic substances such as polymeric materials, thereby offering the advantage of improved solubility in each material. Specifically, hydrogenated paraffin is preferably used as the naphtha (A1). The naphthene (A2) preferably has a kinematic viscosity of 2.9 cSt or more at 40°C. The naphthene (A2) has cyclized molecules and is characterized by its ability to easily dissolve polymeric materials. The polyalphaolefin (A3) preferably has a kinematic viscosity of 2 cSt or less at 100°C. The kinematic viscosity of 1 cSt or more at 100°C is also preferred. The polyalphaolefin (A3) has high solubility and contains few impurities, making it suitable for use. The organic solvent (A4) is an organic solvent other than the naphtha (A1). Specific examples of the organic solvent (A4) include acetone, isopropyl alcohol, ethyl ether, isopropyl acetate, ethyl acetate, normal hexane, methanol, and methyl ethyl ketone. All of the liquid components can also dissolve the additives described below.

[0013] The additive contains a neutral phosphite derivative represented by the following formula (B): The neutral phosphite derivative may be used alone or in combination of two or more.

[0014] Coating compositions are often applied to structures such as buildings and civil engineering structures to protect their substrates. However, when coating films obtained from these coating compositions are exposed to sunlight, the resin components and other components that make up the coating film deteriorate over time due to ultraviolet rays. Specifically, cracking and peeling occur in the coating film. In contrast, coating films obtained from coating compositions containing the paint additive of the present embodiment suppress this type of deterioration over time. This is because the paint additive of the present embodiment contains the neutral phosphite ester derivative in addition to the liquid component. Specifically, the neutral phosphite ester derivative is trivalent and absorbs oxygen, which induces deterioration, to convert to a pentavalent phosphate ester. The pentavalent phosphate ester can irreversibly prevent oxidative degradation without releasing oxygen. Therefore, the neutral phosphite ester derivative prevents the deterioration of the resin components and other components that make up the coating film, making the coating film less susceptible to cracking and peeling. In this way, by producing a coating film using a paint additive containing a neutral phosphite ester derivative, the life of the coating film can be extended.

[0015] [ka]

[0016] In formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms.

[0017] The aliphatic hydrocarbon group having 10 to 16 carbon atoms may be a linear, branched, or cyclic aliphatic hydrocarbon group, and may be a saturated or unsaturated aliphatic hydrocarbon group. Specific examples of the aliphatic hydrocarbon group having 10 to 16 carbon atoms that can be suitably used include linear alkyl groups such as decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and hexadecyl (cetyl) groups.

[0018] R b25 ~R b28 each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms.

[0019] Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an isopropyl group, a sec-butyl group, an isobutyl group, a t-butyl group, an isopentyl group, a t-pentyl group, a neopentyl group, and an isohexyl group.

[0020] Neutral phosphite esters are R b25 ~R b28 It has a specific substituent group, which gives it excellent antioxidant properties.

[0021] In particular, R b25 and R b27 is a linear alkyl group having 1 to 6, preferably 1 to 3, carbon atoms, and R b26 and R b28 When is a branched alkyl group having 3 to 6 carbon atoms, preferably 3 to 4 carbon atoms, the antioxidant performance is further improved.

[0022] R b291 and R b292 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms.

[0023] Examples of the linear or branched alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an isopropyl group, a sec-butyl group, an isobutyl group, a t-butyl group, an isopentyl group, a t-pentyl group, and a neopentyl group.

[0024] However, R b291 and R b292 The total number of carbon atoms in is 1 to 5. Therefore, for example, R b291 When is a hydrogen atom, R b292 is a linear or branched alkyl group having 1 to 5 carbon atoms, and R b291 When is a methyl group, R b292 is a linear or branched alkyl group having 1 to 4 carbon atoms, and R b291When is an ethyl group, R b292 is a straight or branched alkyl group having 2 to 3 carbon atoms.

[0025] From the viewpoint of antioxidant performance, R b291 is a hydrogen atom, and R b292 is more preferably a straight or branched alkyl group having 1 to 5 carbon atoms.

[0026] The additive preferably further comprises at least one selected from 2,6-di-t-butylphenol derivatives and hindered amine compounds. The 2,6-di-t-butylphenol derivatives may be used alone or in combination of two or more. The hindered amine compounds may be used alone or in combination of two or more. The use of 2,6-di-t-butylphenol derivatives has a high ability to trap radicals, thereby further suppressing the deterioration of resin components constituting the coating film. Furthermore, the hindered amine compounds can also efficiently exhibit antioxidant performance in outdoor coating films.

[0027] The 2,6-di-t-butylphenol derivative is represented by the following formula (C).

[0028] [ka]

[0029] In formula (C), R c1 is a straight-chain or branched alkyl group having 1 to 12 carbon atoms. Examples of the straight-chain or branched alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, isobutyl, n-pentyl, isopentyl, t-pentyl, neopentyl, hexyl, heptyl, isoheptyl, n-octyl, isooctyl, 2-ethylhexyl, nonyl, and decyl. The above alkyl groups improve the compatibility of 2,6-di-t-butylphenol derivatives.

[0030] The hindered amine compound is represented by the following formula (D).

[0031] [ka]

[0032] R d21 and R d22 each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0033] The aliphatic hydrocarbon group having 1 to 10 carbon atoms may be a straight-chain, branched or cyclic aliphatic hydrocarbon group, and may be a saturated or unsaturated aliphatic hydrocarbon group.

[0034] Examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, heptyl, octyl, nonyl, decyl, isopropyl, sec-butyl, isobutyl, t-butyl, isopentyl, t-pentyl, neopentyl, isohexyl, and 2-ethylhexyl. Of these, linear or branched alkyl groups having 5 to 10 carbon atoms are more preferred from the viewpoint of antioxidant performance.

[0035] R d23 represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0036] Suitable divalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms include divalent linear or branched alkylene groups such as methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, and 3-methyl-1,5-pentylene. Of these, divalent linear or branched alkylene groups having 5 to 10 carbon atoms are more preferred from the viewpoint of antioxidant performance.

[0037] From the viewpoint of antioxidant performance, among the above, R d21 , R d22 and R d23 The sum of the numbers of carbon atoms is more preferably 16 to 30.

[0038] From the viewpoint of antioxidant performance, the neutral phosphite ester derivative is preferably contained in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the liquid component. Note that the above amount refers to the total amount when two or more liquid components are used, and the total amount when two or more neutral phosphite ester derivatives are used.

[0039] When a 2,6-di-t-butylphenol derivative is used, from the viewpoint of antioxidant performance, it is preferable to contain the 2,6-di-t-butylphenol derivative in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the liquid component. Furthermore, when a hindered amine compound is used, it is preferable to contain the hindered amine compound in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the liquid component, from the viewpoint of antioxidant performance. Note that the above amount refers to the total amount when two or more liquid components are used. Furthermore, when two or more 2,6-di-t-butylphenol derivatives are used, it refers to the total amount, and when two or more hindered amine compounds are used, it refers to the total amount.

[0040] The paint additive can be obtained by mixing a liquid component, a neutral phosphite ester derivative, and, if necessary, a 2,6-di-t-butylphenol derivative and a hindered amine compound.

[0041] [Paint composition] The coating composition of the embodiment includes the above-mentioned coating additive, a resin, and a coating solvent. When the coating composition is used, a coating film with a long life can be obtained.

[0042] The resin is a component that forms a coating film when the coating composition is applied to a structure. Examples of the resin include acrylic resin, silicone resin, acrylic silicone resin, polyester resin, urethane resin, melamine resin, epoxy resin, alkyd resin, fluororesin, polystyrene resin, and polycarbonate resin. The resin may be used alone or in combination of two or more.

[0043] Specifically, the paint solvent is an organic solvent. Depending on the type of resin, an organic solvent capable of dispersing or dissolving the resin can be appropriately selected. Examples of such organic solvents include alcohols such as n-butanol, esters such as butyl acetate and ethyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, glycol ethers such as ethyl cellosolve, and commercially available thinners. The paint solvent may be used alone or in combination of two or more.

[0044] From the viewpoints of ease of application, adhesion and durability of the coating film, the above resin is preferably used in an amount of 15 parts by mass or more and 250 parts by mass or less per 100 parts by mass of the coating solvent.

[0045] The paint additive is preferably used in the paint composition in an amount of 0.01 to 1 part by mass of the neutral phosphite ester derivative per 100 parts by mass of the resin.

[0046] The coating composition of the embodiment may contain a curing agent as needed. The curing agent can be selected appropriately depending on the type of resin. The curing agent may be used alone or in combination of two or more. For example, in the case of a resin containing a hydroxyl group (such as a hydroxyl group-containing acrylic resin, a hydroxyl group-containing acrylic silicone resin, and a hydroxyl group-containing fluororesin), an isocyanate-based curing agent can be suitably used. In the case of an epoxy resin, an amine-based curing agent can be suitably used. The content of the curing agent is adjusted appropriately depending on the amount of groups reactive with the curing agent contained in the resin.

[0047] The coating composition of the embodiment may further contain other components, such as plasticizers, stabilizers, anti-sagging / anti-settling agents, colorants, extender pigments, viscosity modifiers, leveling agents, antifoaming agents, ultraviolet absorbers, and other coating film-forming components.

[0048] Furthermore, the coating composition of the embodiment may be a one-component type or a two-component type.

[0049] The coating composition of the embodiment can be prepared by mixing the above-mentioned coating additive, resin, and coating solvent, as well as a curing agent and other components as needed. Furthermore, when the coating composition of the embodiment is a two-component type, appropriately selected components are mixed to prepare a base composition and a curing agent composition, and the base composition and the curing agent composition can be mixed at the time of application. The curing agent composition may be the curing agent itself, or a mixture of the curing agent and other components.

[0050] The coating composition of the embodiment is suitably applied to the surface of a structure such as an outdoor building or civil engineering structure to form a coating film. The means for applying the coating composition (coating means) is not particularly limited, and examples thereof include spray coating, roller coating, brush coating, trowel coating, and spatula coating. A primer coating film may be formed on the surface of the structure prior to application of the coating composition of the embodiment.

[0051] A structure having a coating film obtained from the coating composition of the embodiment on its surface is exposed to ultraviolet light contained in sunlight, but because the coating film contains a neutral phosphite ester derivative derived from a paint additive, deterioration of the resins that make up the coating film is suppressed, making the coating film less susceptible to cracking and peeling, and extending the life of the coating film.

[0052] Based on the above, the present invention relates to the following. [1] A paint additive comprising, as liquid components, at least one selected from the group consisting of hydrotreated naphtha (A1) having a kinematic viscosity at 40°C of 30 cSt or less, naphthenic mineral oil (A2) having a kinematic viscosity at 40°C of 30 cSt or less, polyalphaolefin (A3) having a kinematic viscosity at 100°C of 4 cSt or less, and organic solvent (A4) having a boiling point of 100°C or less, and a neutral phosphite ester derivative represented by the following formula (B) as an additive. This paint additive suppresses deterioration over time when used in a paint film.

[0053] [ka]

[0054] (In the above formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms, and R b25 ~R b28 each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms; R b291 and R b292 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms; R b291 and R b292 The total number of carbon atoms is 1 to 5. [2] The paint additive according to [1], further comprising at least one selected from the group consisting of a 2,6-di-t-butylphenol derivative represented by the following formula (C) and a hindered amine compound represented by the following formula (D). The use of a 2,6-di-t-butylphenol derivative has a high ability to trap radicals, thereby further suppressing deterioration of the resins and other components that make up the paint film. Furthermore, the hindered amine compound can also efficiently exhibit antioxidant properties in paint films used outdoors.

[0055] [ka]

[0056] (In the above formula (C), Rc1 is a straight-chain or branched alkyl group having 1 to 12 carbon atoms.

[0057] [ka]

[0058] (In the above formula (D), R d21 and R d22 each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and R d23 represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms. [3] The paint additive according to [1] or [2], containing the neutral phosphite ester derivative in an amount of 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the liquid component. [4] The coating additive according to [2], containing the 2,6-di-t-butylphenol derivative in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the liquid component. [5] The paint additive according to [2], containing the hindered amine compound in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the liquid component. When the neutral phosphite derivative, 2,6-di-t-butylphenol derivative, or hindered amine compound is contained in the amount within the above range, the antioxidant performance can be further enhanced. [6] A coating composition comprising the coating additive according to [1] or [2], a resin, and a coating solvent. When the coating composition containing the coating additive is used, a coating film with a long life can be obtained.

[0059] [Example] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples. [Example 1-1] The liquid component used was naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation), and the additives used were a neutral phosphite ester derivative, i.e., 4,4'-butylidenebis(3-methyl-6-t-butylphenyl ditridecyl phosphite), a 2,6-di-t-butylphenol derivative, i.e., octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate (CAS 125643-61-0, trade name: Irganox (registered trademark) L135, manufactured by BASF Japan Ltd.), and a hindered amine compound, i.e., bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) decanedioate. Here, 0.1 parts by mass of a neutral phosphite ester derivative, 0.1 parts by mass of a 2,6-di-t-butylphenol derivative, and 0.1 parts by mass of a hindered amine compound were mixed with 100 parts by mass of the liquid component to obtain a paint additive (1-1). A resin composition was prepared by blending 15 parts by mass of polyester resin with 100 parts by mass of ethyl acetate. A coating additive (1-1) was added to the resin composition and mixed so that the neutral phosphite ester derivative was contained in an amount of 0.1 part by mass per 100 parts by mass of the polyester resin in the resin composition, to obtain a coating composition (1-1). The coating composition (1-1) was applied to a glass plate (3 cm square) and dried to prepare a coating film (1-1) having a thickness of 100 μm. Five coating films (1-1) were prepared.

[0060] [Example 1-2] A paint additive (1-2) was obtained in the same manner as in Example 1-1, except that 100 parts by mass of naphtha (A1) were mixed with 1 part by mass of a neutral phosphite ester derivative, 1 part by mass of a 2,6-di-t-butylphenol derivative, and 1 part by mass of a hindered amine compound. Further, a coating composition (1-2) was obtained in the same manner as in Example 1-1, except that the coating additive (1-2) was used instead of the coating additive (1-1). Next, a coating film (1-2) was prepared in the same manner as in Example 1-1, except that the coating composition (1-2) was used instead of the coating composition (1-1). Five coating films (1-2) were prepared.

[0061] [Examples 1-3] A coating additive (1-3) was obtained in the same manner as in Example 1-1, except that 5 parts by mass of a neutral phosphite ester derivative, 5 parts by mass of a 2,6-di-t-butylphenol derivative, and 5 parts by mass of a hindered amine compound were mixed with 100 parts by mass of naphtha (A1). Further, a coating composition (1-3) was obtained in the same manner as in Example 1-1, except that the coating additive (1-3) was used instead of the coating additive (1-1). Next, a coating film (1-3) was prepared in the same manner as in Example 1-1, except that the coating composition (1-3) was used instead of the coating composition (1-1). Five coating films (1-3) were prepared.

[0062] [Example 2-1] A paint additive (2-1) was obtained in the same manner as in Example 1-2, except that naphthenic mineral oil (A2) (kinematic viscosity at 40°C (JIS K 2283): 2.946 cSt, trade name: SNH3, manufactured by Sankyo Yuka Kogyo Co., Ltd.) was used instead of naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) as the liquid component. Further, a coating composition (2-1) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (2-1). Next, a coating film (2-1) was produced in the same manner as in Example 1-1, except that the coating composition (2-1) was used instead of the coating composition (1-1). Five coating films (2-1) were produced.

[0063] [Example 3-1] A paint additive (3-1) was obtained in the same manner as in Example 1-2, except that polyalphaolefin (A3) (kinematic viscosity at 100°C (JIS K 2283): 1.7 cSt, trade name: SpectraSyn (registered trademark) 2, manufactured by ExxonMobil Corporation) was used instead of naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) as the liquid component. Further, a coating composition (3-1) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (3-1). Next, a coating film (3-1) was produced in the same manner as in Example 1-1, except that the coating composition (3-1) was used instead of the coating composition (1-1). Five coating films (3-1) were produced.

[0064] [Example 3-2] A paint additive (3-2) was obtained in the same manner as in Example 1-2, except that polyalphaolefin (A3) (kinematic viscosity at 100°C (JIS K 2283): 2.0 cSt, trade name: SpectraSyn (registered trademark) 2C, manufactured by ExxonMobil Corporation) was used instead of naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) as the liquid component. Further, a coating composition (3-2) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (3-2). Next, a coating film (3-2) was produced in the same manner as in Example 1-1, except that the coating composition (3-2) was used instead of the coating composition (1-1). Five coating films (3-2) were produced.

[0065] [Example 3-3] A paint additive (3-3) was obtained in the same manner as in Example 1-2, except that polyalphaolefin (A3) (kinematic viscosity at 100°C (JIS K 2283): 1.7 cSt, trade name: Synfluid (registered trademark) PAO 2 cSt, manufactured by Chevron Phillips Chemical Co.) was used instead of naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) as the liquid component. Further, a coating composition (3-3) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (3-3). Next, a coating film (3-3) was produced in the same manner as in Example 1-1, except that the coating composition (3-3) was used instead of the coating composition (1-1). Five coating films (3-3) were produced.

[0066] [Example 3-4] A paint additive (3-4) was obtained in the same manner as in Example 1-2, except that polyalphaolefin (A3) (kinematic viscosity at 100°C (JIS K 2283): 1.9 cSt, trade name: Durasyn (registered trademark) 162, manufactured by INEOS Oligomers) was used instead of naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) as the liquid component. Further, a coating composition (3-4) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (3-4). Next, a coating film (3-4) was prepared in the same manner as in Example 1-1, except that the coating composition (3-4) was used instead of the coating composition (1-1). Five coating films (3-4) were prepared.

[0067] [Example 4-1] A paint additive (4-1) was obtained in the same manner as in Example 1-2, except that an organic solvent (A4) (ethyl acetate) was used instead of naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) as the liquid component. Further, a coating composition (4-1) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (4-1). Next, a coating film (4-1) was produced in the same manner as in Example 1-1, except that the coating composition (4-1) was used instead of the coating composition (1-1). Five coating films (4-1) were produced.

[0068] [Examples 5-1 to 5-6] As a neutral phosphite derivative, 4,4'-butylidenebis(3-methyl-6-t-butylphenyl ditridecyl phosphite) (R in the above formula (B) b21 ~R b24 = tridecyl group, R b25 , R b27 = methyl group, R b26 , R b28 = t-butyl group, R b291 = hydrogen atom, R b292 Paint additives (5-1) to (5-6) were obtained in the same manner as in Example 1-2, except that the compounds in Table 1 were used instead of (=n-propyl group). Moreover, coating compositions (5-1) to (5-6) were obtained in the same manner as in Example 1-1, except that coating additives (5-1) to (5-6) were used instead of coating additive (1-1). Next, coating films (5-1) to (5-6) were prepared in the same manner as in Example 1-1, except that coating compositions (5-1) to (5-6) were used instead of coating composition (1-1). Five coating films (5-1) to (5-6) were prepared for each of the coating compositions.

[0069] [Table 1]

[0070] [Examples 6-1 to 6-6] As a hindered amine compound, bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) decanedioate (R d21 , R d22 = n-octyl group, R d23 Paint additives (6-1) to (6-6) were obtained in the same manner as in Example 1-2, except that the compounds in Table 2 were used instead of (C = 1,8-octylene group). Furthermore, coating compositions (6-1) to (6-6) were obtained in the same manner as in Example 1-1, except that coating additives (6-1) to (6-6) were used instead of coating additive (1-1). Next, coating films (6-1) to (6-6) were prepared in the same manner as in Example 1-1, except that coating compositions (6-1) to (6-6) were used instead of coating composition (1-1). Five coating films (6-1) to (6-6) were prepared for each of these coating compositions.

[0071] [Table 2]

[0072] [Example 7-1] Naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) was used as the liquid component, and a neutral phosphite derivative, i.e., 4,4'-butylidenebis(3-methyl-6-t-butylphenyl ditridecyl phosphite), was used as the additive. Here, 100 parts by mass of the liquid component was mixed with 1 part by mass of the neutral phosphite ester derivative to obtain a paint additive (7-1). Further, a coating composition (7-1) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (7-1). Next, a coating film (7-1) was produced in the same manner as in Example 1-1, except that the coating composition (7-1) was used instead of the coating composition (1-1). Five coating films (7-1) were produced.

[0073] [Example 7-2] The liquid component used was naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation), and the additives used were a neutral phosphite ester derivative, i.e., 4,4'-butylidenebis(3-methyl-6-t-butylphenyl ditridecyl phosphite), and a 2,6-di-t-butylphenol derivative, i.e., octyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate (CAS 125643-61-0, trade name: Irganox (registered trademark) L135, manufactured by BASF Japan Ltd.). Here, 100 parts by mass of the liquid component was mixed with 1 part by mass of the neutral phosphite ester derivative and 1 part by mass of the 2,6-di-t-butylphenol derivative to obtain a paint additive (7-2). Further, a coating composition (7-2) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (7-2). Next, a coating film (7-2) was prepared in the same manner as in Example 1-1, except that the coating composition (7-2) was used instead of the coating composition (1-1). Five coating films (7-2) were prepared.

[0074] [Example 7-3] Naphtha (A1) (hydrogenated paraffin, kinematic viscosity at 40°C (JIS K 2283): 1.19 cSt, trade name: Isopar (registered trademark) G, manufactured by ExxonMobil Corporation) was used as the liquid component, and a neutral phosphite derivative, i.e., 4,4'-butylidenebis(3-methyl-6-t-butylphenyl ditridecyl phosphite), and a hindered amine compound, i.e., bis(2,2,6,6-tetramethyl-1-(octyloxy)piperidin-4-yl) decanedioate, were used as additives. Here, 100 parts by mass of the liquid component were mixed with 1 part by mass of the neutral phosphite ester derivative and 1 part by mass of the hindered amine compound to obtain a coating additive (7-3). Further, a coating composition (7-3) was obtained in the same manner as in Example 1-1, except that the coating additive (1-1) was replaced with the coating additive (7-3). Next, a coating film (7-3) was prepared in the same manner as in Example 1-1, except that the coating composition (7-3) was used instead of the coating composition (1-1). Five coating films (7-3) were prepared.

[0075] [Comparative Example 1-1] A resin composition was prepared by blending 15 parts by mass of polyester resin with 100 parts by mass of ethyl acetate. The resin composition was applied to a glass plate (3 cm square) and dried to prepare a coating film (1-1') having a thickness of 100 μm. Five coating films (1-1') were prepared.

[0076] [Evaluation method and results] Of the five coating films (1-1) produced in Example 1-1, the first to fifth were used in the following heating tests 1 to 5, respectively. The following heating tests 1 to 5 were also carried out in the same manner for the coating films produced in the other examples and comparative examples. (Heating test 1) The prepared coating film was placed in an incubator and kept at 80°C for one month. (Heating test 2) The prepared coating film was placed in an incubator and kept at 80°C for 3 months. (Heating test 3) The prepared coating film was placed in an incubator and kept at 80°C for 6 months. (Heating test 4) The prepared coating film was placed in an incubator and kept at 80°C for one month under ultraviolet irradiation. (Heating test 5) The prepared coating film was placed in an incubator and kept at 80°C for 3 months under ultraviolet irradiation. (External observation) For each of the coating films subjected to Heating Tests 1 to 5, the coating film was removed from the incubator, cooled to room temperature, and then its appearance was observed. Specifically, a score of ◯ was given if there was no change in the coating film and no clouding or peeling was observed on the surface of the coating film, and an X was given if clouding or peeling was observed on the surface of the coating film. The test results are shown in Table 3.

[0077] [Table 3]

[0078] In all examples, even after Heating Tests 1, 2, and 4, the coating film remained unchanged upon visual observation, and neither clouding nor peeling was observed on the coating film surface. It can be seen that deterioration over time is suppressed in coating films using the paint additive of the embodiment. In examples using paint additives containing a neutral phosphite ester derivative, a 2,6-di-t-butylphenol derivative, and a hindered amine compound, even after Heating Tests 3 and 5, the coating film remained unchanged upon visual observation, and neither clouding nor peeling was observed on the coating film surface. It can be seen that the combined use of a neutral phosphite ester derivative, a 2,6-di-t-butylphenol derivative, and a hindered amine compound suppresses deterioration over time, even when used outdoors for long periods of time.

Claims

1. As a liquid component, at least one selected from the group consisting of hydrotreated naphtha (A1) having a kinematic viscosity at 40°C of 30 cSt or less, naphthenic mineral oil (A2) having a kinematic viscosity at 40°C of 30 cSt or less, polyalphaolefin (A3) having a kinematic viscosity at 100°C of 4 cSt or less, and organic solvent (A4) having a boiling point of 100°C or less; and a neutral phosphite ester derivative represented by the following formula (B) as an additive, Paint additives. 【Chemistry 1】 (In the above formula (B), R b21 ~R b24 each independently represents an aliphatic hydrocarbon group having 10 to 16 carbon atoms; R b25 ~R b28 each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms; R b291 and R b292 each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms; R b291 and R b292 The total number of carbon atoms is 1 to 5.

2. The additive further contains at least one selected from a 2,6-di-t-butylphenol derivative represented by the following formula (C) and a hindered amine compound represented by the following formula (D): The paint additive according to claim 1. 【Chemistry 2】 (In the above formula (C), R c1 is a straight or branched alkyl group having 1 to 12 carbon atoms. 【Transformation 3】 (In the above formula (D), R d21 and R d22 each independently represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms; R d23 represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms.

3. The neutral phosphite ester derivative is contained in an amount of 0.1 parts by mass or more and 5 parts by mass or less relative to 100 parts by mass of the liquid component. The paint additive according to claim 1 or 2.

4. The 2,6-di-t-butylphenol derivative is contained in an amount of 0.1 parts by mass or more and 5 parts by mass or less relative to 100 parts by mass of the liquid component. The paint additive according to claim 2.

5. The hindered amine compound is contained in an amount of 0.1 parts by mass or more and 5 parts by mass or less relative to 100 parts by mass of the liquid component. The paint additive according to claim 2.

6. A coating composition comprising the coating additive according to claim 1 or 2, a resin, and a coating solvent.

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