Fluorine-containing copolymer liquid composition and coating material

Abstract

Provided are: a fluorine-containing copolymer liquid composition which is used as a raw material for a coating material capable of forming a coating film having excellent light resistance; and a coating material. The fluorine-containing copolymer liquid composition according to the present invention contains: a fluorine-containing copolymer having a chlorotrifluoroethylene-based unit and a vinyl ether-based unit; a piperidinyl group-containing compound; ethyl benzene; and mixed xylene, in which the mass ratio of the content of the ethylbenzene to the content of the mixed xylene is 0.3-3.0.

Description

Technical Field

[0001] The present invention relates to fluorinated copolymer liquid compositions and coatings. Background Art

[0002] Coatings containing fluorinated copolymers can form coating films with excellent properties and are therefore used in a variety of fields. For example, Patent Document 1 discloses a method in which a monomer mixture containing a fluoroolefin, a monomer having a crosslinking group, and a monomer having neither a fluorine atom nor a crosslinking group is polymerized in the presence of a piperidinyl-containing compound and xylene to obtain a fluorinated copolymer solution, which is then used as a raw material for a coating.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2014 / 054545 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In recent years, there has been a demand for further improvement in the light resistance of coatings obtained using coatings containing fluorinated copolymers. The present inventors prepared a coating using the fluorinated copolymer solution described in Patent Document 1 and evaluated coatings formed using the resulting coating. The results revealed room for improvement in light resistance.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a fluorinated copolymer liquid composition and a coating material used as a raw material for a coating material capable of forming a coating film having excellent light resistance.

[0009] Solutions for solving problems

[0010] The present inventors conducted intensive studies and found that the above-mentioned problems can be solved by the following configuration.

[0011] [1] A fluorinated copolymer liquid composition comprising: a fluorinated copolymer having units based on chlorotrifluoroethylene and units based on vinyl ether; a piperidinyl-containing compound; ethylbenzene; and mixed xylenes comprising at least two of o-xylene, m-xylene, and p-xylene, wherein the mass ratio of the ethylbenzene content to the mixed xylene content is 0.3 to 3.0.

[0012] [2] The fluorinated copolymer liquid composition according to [1], wherein the mixed xylene comprises all of o-xylene, m-xylene and p-xylene.

[0013] [3] The fluorinated copolymer liquid composition according to [1] or [2], wherein the piperidinyl group-containing compound is a compound represented by formula (N1) described below.

[0014] In the formula (1) described below,

[0015] R 11 ~R 14 Each independently represents an alkyl group, a cycloalkyl group, a substituted alkyl group, an aryl group or an aralkyl group having 1 to 18 carbon atoms, and R 11 With R 12 , or R 13 With R 14 optionally forming an aliphatic ring having 3 to 6 carbon atoms,

[0016] R 15 is a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, an aralkyl group or a cycloalkyl group,

[0017] R 16 It is a hydrogen atom, a hydroxyl group, an alkyl group, a substituted alkyl group, an aryl group, an aralkyl group, an ester bond-containing group, an amino group-containing group, a 2,2,6,6-tetrasubstituted piperidinyl group-containing group, or a group formed by combining two or more of these groups.

[0018] [4] The fluorinated copolymer liquid composition according to any one of [1] to [3], wherein the content of the piperidinyl group-containing compound is 0.1 to 2 mass % based on the total mass of the fluorinated copolymer liquid composition.

[0019] [5] The fluorinated copolymer liquid composition according to any one of [1] to [4], wherein the mass ratio of the content of the piperidinyl group-containing compound to the content of the ethylbenzene is 0.001 to 0.2.

[0020] [6] A coating material comprising the fluorinated copolymer liquid composition according to any one of [1] to [5].

[0021] Effects of the Invention

[0022] According to the present invention, there can be provided a fluorinated copolymer liquid composition and a coating material which are used as a raw material for a coating material capable of forming a coating film having excellent light resistance. DETAILED DESCRIPTION

[0023] The meanings of the terms in the present invention are as follows.

[0024] The numerical range expressed as "to" refers to a range that includes the numerical values ​​recorded before and after "to" as the lower limit and upper limit. In the numerical ranges recorded at different stages in this specification, the upper limit or lower limit recorded in a certain numerical range can be replaced by the upper limit or lower limit of the numerical range recorded at different stages. In addition, in the numerical ranges recorded in this specification, the upper limit or lower limit recorded in a certain numerical range can be replaced by the values ​​shown in the examples.

[0025] In this specification, each component may be used alone or in combination of two or more. Here, when two or more substances are used in combination, the content of the component, unless otherwise specified, refers to the total content of the substances used in combination.

[0026] In this specification, a combination of two or more preferred aspects is a more preferred aspect.

[0027] Units are a collective term for atomic groups based on a single monomer molecule formed directly through polymerization, as well as atomic groups obtained by chemically converting a portion of such atomic groups. The content (mol %) of each unit relative to the total units contained in the polymer can be determined by analyzing the polymer using nuclear magnetic resonance spectroscopy or by the amounts of the components used in polymer production.

[0028] (Meth)acrylic acid is a general term for acrylic acid and methacrylic acid.

[0029] The hydrolyzable silyl group refers to a group that can undergo a hydrolysis reaction to form a silanol group.

[0030] The acid value and the hydroxyl value are values ​​measured according to the method of JIS K 0070-3 (1992).

[0031] The glass transition temperature (Tg) is the midpoint glass transition temperature of a polymer as measured by differential scanning calorimetry (DSC).

[0032] The melt viscosity is a value of the melt viscosity of a sample at 170° C. when measured using a rotational rheometer at a temperature increase rate of 10° C. / min from 130° C. to 200° C.

[0033] The number average molecular weight (Mn) and weight average molecular weight (Mw) are values ​​measured by size exclusion chromatography (gel permeation chromatography) using polystyrene as a standard substance. In addition, the ratio of Mw to Mn represents the molecular weight distribution and is also called Mw / Mn.

[0034] The average particle size of the particles is a value of 50% particle size obtained by calculating the volume average from the particle size distribution measured using a known particle size distribution measuring apparatus (such as Sympatec's trade name Helos-Rodos) based on the laser diffraction method.

[0035] The film thickness is a value measured using an eddy current film thickness meter (Sanko Electric Laboratory Co., Ltd., trade name: EDY-5000, etc.).

[0036] The fluorinated copolymer liquid composition of the present invention (hereinafter also referred to as the present liquid composition) comprises: a fluorinated copolymer having units derived from chlorotrifluoroethylene and units derived from vinyl ether; a piperidinyl group-containing compound; ethylbenzene; and mixed xylenes.

[0037] In the present liquid composition, the mass ratio of the ethylbenzene content to the mixed xylene content is 0.3 to 3.0.

[0038] The coating film obtained using the coating material containing the present liquid composition has excellent light resistance. The reason for this is not necessarily clear, but it is considered as follows.

[0039] That is, it is considered that the inclusion of ethylbenzene improves the dispersibility of the piperidinyl group-containing compound in the coating material, which contributes to the improvement of the light resistance of the coating film.

[0040] Furthermore, it is believed that, although the boiling points of ethylbenzene and mixed xylenes are close, there is a slight difference. Therefore, during film formation, the vaporization of ethylbenzene and mixed xylenes occurs gradually but relatively smoothly. This is believed to be because, as ethylbenzene and mixed xylenes vaporize, some of the piperidinyl-containing compounds tend to migrate to the vicinity of the coating film surface.

[0041] From these reasons, it is estimated that the light resistance of the coating film is improved.

[0042] In this specification, a fluorinated copolymer having units derived from chlorotrifluoroethylene and units derived from vinyl ether is referred to as a specific fluorinated copolymer.

[0043] The content of the units derived from chlorotrifluoroethylene is preferably from 30 to 70 mol %, more preferably from 40 to 60 mol %, further preferably from 45 to 55 mol %, based on the total repeating units of the specific fluorinated copolymer, from the viewpoint of further improving the weather resistance of a coating film obtained by using the specific fluorinated copolymer.

[0044] The vinyl ether may be a vinyl ether having a crosslinkable group or a vinyl ether not having a crosslinkable group.

[0045] The vinyl ether preferably has a crosslinkable group from the viewpoint of further improving the durability of a coating film obtained using the specific fluorinated copolymer.

[0046] Specific examples of the crosslinking group include at least one group selected from the group consisting of a hydroxyl group, an amino group, an epoxy group, an oxetane group, a hydrolyzable silyl group, a sulfo group, and a carboxyl group. From the perspective of further improving the hardness of the coating film obtained using the specific fluorinated copolymer, a hydroxyl group or a carboxyl group is preferred, and a hydroxyl group is more preferred. It should be noted that the sulfo group and the carboxyl group can be ionized to form -SO3 - or -COO - , can also form salts with cations to become -SO3 - Na + or -COO - Na + wait.

[0047] The number of crosslinkable groups may be 1 or 2 or more. Two or more crosslinkable groups may be used in combination.

[0048] Two or more types of vinyl ethers may be used in combination, and among these, a combination of a vinyl ether having a crosslinkable group and a vinyl ether not having a crosslinkable group is preferred.

[0049] Vinyl ether may or may not have a fluorine atom, but preferably does not have a fluorine atom.

[0050] When the specific fluorinated copolymer has units based on a vinyl ether having a crosslinkable group, the crosslinkable groups may be present in a state where a part or all of them have reacted with other components (e.g., a curing agent, etc.), or in a state where they have not reacted with other components. However, it is preferred that the crosslinkable groups be present in a state where they have not reacted with other components. In other words, the specific fluorinated copolymer in the present liquid composition may be present in a state where it has a crosslinked structure based on a curing agent, or it may be present in a state where it has not a crosslinked structure.

[0051] The units based on a vinyl ether having a crosslinkable group may be units obtained by converting a specific fluorinated copolymer containing units based on a vinyl ether having a crosslinkable group into a different crosslinkable group. Examples of such units include units obtained by reacting a specific fluorinated copolymer containing units based on a vinyl ether having a hydroxyl group with a polycarboxylic acid, an anhydride thereof, or the like, thereby converting some or all of the hydroxyl groups into carboxyl groups.

[0052] Two or more types of vinyl ethers having a crosslinkable group may be used in combination.

[0053] Specific examples of vinyl ethers having a hydroxyl group include CH2=CHO-CH2-cycloC6H 10-CH2OH, CH2=CHOCH2CH2OH, CH2=CHOCH2CH2CH2CH2OH.

[0054] It should be noted that "-cycloC6H 10 -" represents cyclohexylene, "-cycloC6H 10 -" is usually a 1,4-bonding site.

[0055] Two or more vinyl ethers having a hydroxyl group may be used in combination.

[0056] Specific examples of vinyl ethers having a carboxyl group include CH2=CHO(CH2) n12 A monomer represented by OC(O)CH2CH2COOH (wherein n12 represents an integer of 1 to 10).

[0057] Two or more types of vinyl ethers having a carboxyl group may be used in combination.

[0058] Specific examples of the vinyl ether having no crosslinkable group include ethyl vinyl ether, tert-butyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, and cyclohexyl methyl vinyl ether.

[0059] Two or more vinyl ethers having no crosslinkable group may be used in combination.

[0060] The content of the units derived from vinyl ether is preferably from 1 to 80 mol%, more preferably from 10 to 70 mol%, further preferably from 20 to 60 mol%, based on all repeating units of the specific fluorinated copolymer.

[0061] When the units based on vinyl ether include units based on vinyl ether having a crosslinkable group, the content of the units based on vinyl ether having a crosslinkable group is preferably from 1 to 30 mol %, more preferably from 3 to 25 mol %, further preferably from 5 to 20 mol % based on the total repeating units of the specific fluorinated copolymer, from the viewpoint of further improving the durability of a coating film obtained using the specific fluorinated copolymer.

[0062] When the units based on vinyl ether include units based on vinyl ether having no crosslinking group, the content of the units based on vinyl ether having no crosslinking group is preferably from 1 to 70 mol%, more preferably from 5 to 60 mol%, further preferably from 10 to 50 mol%, based on the total repeating units of the specific fluorinated copolymer, from the viewpoint of further improving the smoothness and hardness of a coating film obtained using the specific fluorinated copolymer.

[0063] The specific fluorinated copolymer may contain units other than the units based on chlorotrifluoroethylene and the units based on vinyl ether (hereinafter also referred to as other units). However, it is preferred that the specific fluorinated copolymer contains substantially no other units since a coating film obtained using the specific fluorinated copolymer has more excellent light resistance.

[0064] Here, “substantially containing no other units” means that the content of other units is at most 0.1 mol % based on all repeating units of the specific fluorinated copolymer.

[0065] Specific examples of the other units include units based on fluoroolefins other than chlorotrifluoroethylene and units based on vinyl esters.

[0066] The specific fluorinated copolymer preferably does not have a carboxyl group from the viewpoint of further improving the hardness of a coating film obtained using the specific fluorinated copolymer. In this case, the specific fluorinated copolymer preferably has a hydroxyl group.

[0067] The specific fluorinated copolymer preferably comprises units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether having no crosslinkable group. It is more preferably a fluorinated copolymer consisting essentially of units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether having no crosslinkable group. It is still more preferably a fluorinated copolymer consisting solely of units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether having no crosslinkable group.

[0068] The term “a fluorinated copolymer consisting essentially of units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether not having a crosslinkable group” means that the content of units other than units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether not having a crosslinkable group is at most 0.1 mol% based on all repeating units of the specific fluorinated copolymer.

[0069] The specific fluorinated copolymer preferably contains, in order, 30 to 70 mol%, 1 to 30 mol%, and 1 to 70 mol% of units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether having no crosslinkable group, relative to all units comprised in the specific fluorinated copolymer. It is more preferred that the specific fluorinated copolymer contain, in order, 45 to 55 mol%, 5 to 20 mol%, and 10 to 50 mol% of units based on chlorotrifluoroethylene, units based on vinyl ether having a crosslinkable group, and units based on vinyl ether having no crosslinkable group.

[0070] The Tg of the specific fluorinated copolymer is preferably from 20 to 60°C, more preferably from 25 to 60°C, further preferably from 30 to 55°C, from the viewpoint of hardness and flex resistance of the coating film.

[0071] When the specific fluorinated copolymer has a hydroxyl value, the hydroxyl value of the specific fluorinated copolymer is preferably higher than 0 mgKOH / g and lower than 150 mgKOH / g, more preferably 5 to 120 mgKOH / g, further preferably 15 to 110 mgKOH / g, particularly preferably 30 to 100 mgKOH / g.

[0072] When the specific fluorinated copolymer has an acid value, the acid value of the specific fluorinated copolymer is preferably higher than 0 mgKOH / g and lower than 10 mgKOH / g, more preferably from 2 to 8 mgKOH / g, further preferably from 3 to 7 mgKOH / g.

[0073] From the viewpoint of further improving the effects of the present invention, the Mw of the specific fluorinated copolymer is preferably from 10,000 to 60,000, more preferably from 12,000 to 55,000, further preferably from 15,000 to 50,000.

[0074] From the viewpoint of further improving the effects of the present invention, the Mn of the specific fluorinated copolymer is preferably from 5,000 to 20,000, more preferably from 6,000 to 18,000, further preferably from 7,000 to 16,000.

[0075] From the viewpoint of further improving the effects of the present invention, the Mw / Mn (molecular weight distribution) of the specific fluorinated copolymer is preferably from 2.0 to 3.5, more preferably from 2.1 to 3.3, further preferably from 2.2 to 3.2.

[0076] The content of the specific fluorinated copolymer is preferably 40 to 80% by mass, more preferably 50 to 70% by mass, and even more preferably 55 to 65% by mass relative to the total mass of the liquid composition. When the content of the specific fluorinated copolymer is 40% by mass or greater, viscosity adjustment of the coating is facilitated. Furthermore, when the content of the specific fluorinated copolymer is 80% by mass or less, handling (workability) during coating mixing is excellent.

[0077] Examples of methods for producing the specific fluorinated copolymer include solution polymerization, emulsion polymerization, and suspension polymerization. Solution polymerization is preferred from the perspective of water resistance. Therefore, the specific fluorinated copolymer is preferably produced by polymerizing the monomers in the presence of a polymerization solvent.

[0078] During the polymerization, a polymerization initiator, a chain transfer agent, a stabilizer, an acid absorbent, etc. may be added as needed.

[0079] The piperidinyl group-containing compound may be derived from the components used in producing the specific fluorinated copolymer, or may be added during the production of the present liquid composition.

[0080] The piperidinyl group-containing compound refers to a compound having a piperidinyl group or a piperidinyl group having a substituent, and more preferably a compound having a piperidinyl group having a substituent.

[0081] The piperidinyl group having a substituent is preferably a tetrasubstituted piperidinyl group, and more preferably a 2,2,6,6-tetrasubstituted piperidinyl group.

[0082] The piperidinyl group-containing compound is preferably a piperidinyl group-containing compound having two or more piperidinyl groups or a piperidinyl group having a substituent.

[0083] It is preferable to use two or more piperidinyl group-containing compounds.

[0084] The piperidinyl group-containing compound is preferably a compound represented by the following formula (N1) (a compound having a 2,2,6,6-tetrasubstituted piperidinyl group) in that the light resistance of the coating film is further improved.

[0085]

[0086] R 11 ~R 14 Each independently represents an alkyl group, a cycloalkyl group, a substituted alkyl group, an aryl group or an aralkyl group having 1 to 18 carbon atoms, and R 11 With R 12 , or R 13 With R 14 Optionally, it forms an aliphatic ring having 3 to 6 carbon atoms. 11 ~R 14 In view of price and availability, an alkyl group having 1 to 18 carbon atoms is preferred, and a methyl group is particularly preferred.

[0087] Specific examples of the alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, a propyl group, a dodecyl group, a stearyl group, and the like. As mentioned above, a methyl group is preferred.

[0088] Specific examples of the cycloalkyl group include cyclopentyl and cyclohexyl.

[0089] The substituted alkyl group is an alkyl group having a substituent at any position, and examples of the substituent include hydroxyl group, alkoxy group, etc. Specific examples of the substituted alkyl group include 2-hydroxyethyl group, 2-methoxycarbonylethyl group, 3-hydroxypropyl group, etc.

[0090] Specific examples of the aryl group include a phenyl group and a naphthyl group.

[0091] Specific examples of the aralkyl group include a phenethyl group and a benzyl group.

[0092] R 15 is a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, an aralkyl group or a cycloalkyl group.

[0093] Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a dodecyl group, and a stearyl group.

[0094] The substituted alkyl group is an alkyl group having a substituent at any position, and examples of the substituent include a hydroxyl group, an alkoxy group, an acetoxy group, a carbonyl group, etc. Specific examples of the substituted alkyl group include a 2-hydroxyethyl group, a 2-methoxycarbonylethyl group, a 2-acetoxyethyl group, a 2-(3-methoxycarbonylpropionyloxy)ethyl group, and a 3-hydroxypropyl group.

[0095] Specific examples of the aryl group include a phenyl group, a naphthyl group, and a hydroxyphenyl group.

[0096] Specific examples of the aralkyl group include a phenethyl group, a benzyl group, and a hydroxyphenylalkyl group.

[0097] Specific examples of the cycloalkyl group include a cyclohexyl group.

[0098] R 16 R is a hydrogen atom, a hydroxyl group, an alkyl group, a substituted alkyl group, an aryl group, an aralkyl group, a group containing an ester bond, a group containing an amino group, or a group containing a 2,2,6,6-tetrasubstituted piperidinyl group. 16 A combination of two or more of these groups may also be used.

[0099] Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a dodecyl group, and a stearyl group.

[0100] The substituted alkyl group is an alkyl group having a substituent at any position, and examples of the substituent include a hydroxyl group, an alkoxy group, an acetoxy group, a carbonyl group, etc. Specific examples of the substituted alkyl group include a 2-hydroxyethyl group, a 2-methoxycarbonylethyl group, a 2-acetoxyethyl group, a 2-(3-methoxycarbonylpropionyloxy)ethyl group, and a 3-hydroxypropyl group.

[0101] Specific examples of the aryl group include a phenyl group and a naphthyl group.

[0102] Specific examples of the aralkyl group include a phenethyl group and a benzyl group.

[0103] Specific examples of the ester bond-containing group include an acetoxy group, a propionyloxy group, a butyryloxy group, a lauroyloxy group, a substituted alkylcarbonyloxy group, a benzoyloxy group, and a substituted benzoyloxy group.

[0104] Specific examples of the amino group-containing group include an alkoxycarbonylamino group, an N-monoalkylcarbamoylamino group, and an N,N-dialkylcarbamoylamino group.

[0105] Specific examples of the piperidinyl group-containing compound include 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 1-ethyl-2,2,6,6-tetramethylpiperidine, 1-ethyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-butyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-dodecyl-2,2,6,6-tetramethylpiperidine, 1-phenyl-2,2,6,6-tetramethylpiperidine, 1-(2-hydroxyethyl)-2,2,6,6-tetramethylpiperidine, 1-(6-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-acetoxy-2,2,6,6-tetramethylpiperidine, Piperidine, 4-acetoxy-1,2,2,6,6-pentamethylpiperidine, 1-(2-acetoxyethyl)-4-acetoxy-2,2,6,6-tetramethylpiperidine, 1-(2-benzoyloxyethyl)-4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-ethyl-2,2,6,6-tetramethylpiperidine, 4-ethyl-1,2,2,6,6-pentamethylpiperidine, 4-butyl-2,2,6,6-tetramethylpiperidine, 4-octyl-2,2,6,6-tetramethylpiperidine, 4-dodecyl-2,2,6,6-tetramethylpiperidine, 4-stearyl-2,2,6,6-tetramethylpiperidine, 4-stearyl-1,2,2,6,6-pentamethylpiperidine, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (Methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate), bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate.

[0106] As R 16 Examples of the piperidinyl-containing compound containing a group containing a 2,2,6,6-tetrasubstituted piperidinyl group include piperidinyl-containing compounds containing two or more 2,2,6,6-tetramethylpiperidinyl groups in one molecule obtained by reacting a hydroxyl group-containing 2,2,6,6-tetramethylpiperidine (such as 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, and 1-(2-hydroxyethyl)-2,2,6,6-tetramethylpiperidine) with a polybasic acid (such as succinic acid, adipic acid, sebacic acid, azelaic acid, decane-1,10-dicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, malonic acid, and substituted malonic acid). Specific examples include compounds represented by the following formula.

[0107] Here, n3 is an integer of 1 to 20. In the following compounds, n means normal.

[0108]

[0109] The content of the piperidinyl-containing compound is preferably 0.1 to 2 mass %, more preferably 0.2 to 1.5 mass %, and even more preferably 0.3 to 1 mass %, relative to the total mass of the liquid composition. When the content of the piperidinyl-containing compound is 0.1 mass % or greater, the light resistance of the coating film is further improved. Furthermore, when the content of the piperidinyl-containing compound is 2 mass % or less, yellowing of the coating film is suppressed.

[0110] Ethylbenzene may be a polymerization solvent used in producing the specific fluorinated copolymer, or may be added separately from the polymerization solvent in producing the present liquid composition.

[0111] Here, the normal boiling point of ethylbenzene is 136° C. In addition, in this specification, the normal boiling point refers to the boiling point at 1 atm.

[0112] The ethylbenzene content is preferably 10 to 40% by mass, more preferably 12 to 28% by mass, and even more preferably 18 to 22% by mass, relative to the total mass of the liquid composition. When the ethylbenzene content is 10% by mass or greater, the light resistance of the coating film is further improved. When the ethylbenzene content is 40% by mass or less, the durability of the coating film is further improved.

[0113] In the present liquid composition, the mass ratio of the piperidinyl-containing compound content to the ethylbenzene content (piperidinyl-containing compound content / ethylbenzene content) is preferably 0.001 to 0.2, more preferably 0.003 to 0.15, further preferably 0.015 to 0.07, and particularly preferably 0.02 to 0.05.

[0114] When the mass ratio is 0.001 or more, the light resistance of the coating film is further improved, and when the mass ratio is 0.2 or less, the durability of the coating film is further improved.

[0115] The mixed xylene may be the polymerization solvent used in producing the specific fluorinated copolymer, or may be added separately from the above-mentioned polymerization solvent in producing the present liquid composition.

[0116] In the present invention, mixed xylene refers to a mixture of structural isomers of xylene, including o-xylene, m-xylene, and p-xylene. Mixed xylene is a mixture of at least two of o-xylene, m-xylene, and p-xylene, preferably a mixture of all of o-xylene, m-xylene, and p-xylene.

[0117] Here, the normal boiling points of o-xylene, m-xylene, and p-xylene are 144° C., 139° C., and 138° C., respectively.

[0118] The content of the mixed xylene is preferably 10 to 40% by mass, more preferably 12 to 28% by mass, and even more preferably 18 to 22% by mass relative to the total mass of the liquid composition. When the content of the mixed xylene is 10% by mass or greater, the leveling properties of the coating film are further improved. Furthermore, when the content of the mixed xylene is 40% by mass or less, the drying properties of the coating film are further improved.

[0119] The content of o-xylene is preferably 10 to 50% by mass, more preferably 20 to 40% by mass, based on the total mass of the mixed xylene.

[0120] In the present liquid composition, the mass ratio of the ethylbenzene content to the mixed xylene content (ethylbenzene content / mixed xylene content) is 0.3 to 3.0, preferably 0.6 to 2.0, more preferably 0.7 to 1.5, and even more preferably 0.8 to 1.3 from the viewpoint of better light resistance of the coating film.

[0121] In the present liquid composition, the total content of ethylbenzene and mixed xylenes is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more relative to the total mass of the present liquid composition, from the perspective of excellent film thickness.

[0122] From the viewpoint of an appropriate viscosity of the present liquid composition, the total content of ethylbenzene and mixed xylenes is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less relative to the total mass of the present liquid composition.

[0123] The present liquid composition may contain components other than those described above (hereinafter also referred to as other components).

[0124] Specific examples of other components include solvents other than ethylbenzene and mixed xylenes (hereinafter also referred to as other solvents), polymerization inhibitors, dispersants, and leveling agents.

[0125] When the present liquid composition contains other components, the content of the other components is preferably 0.05 to 1% by mass, more preferably 0.1 to 0.5% by mass relative to the total mass of the present liquid composition, from the viewpoint of further improving impact resistance and smoothness.

[0126] Specific examples of other solvents include organic solvents such as alcohols (eg, ethanol) and cyclohexanone.

[0127] When the present liquid composition contains other solvents, the content of the other solvents is preferably greater than 0% by mass and less than 2% by mass, more preferably 0.03 to 1.5% by mass, relative to the total mass of the present liquid composition, from the viewpoint of further improving impact resistance and smoothness.

[0128] The normal boiling point of the solvent contained in the present liquid composition is preferably 120-150°C, more preferably 130-150°C, and even more preferably 135-145°C, from the viewpoint of improving vaporization efficiency during coating film formation and improving light resistance of the coating film.

[0129] The method for producing the present liquid composition is not particularly limited. For example, the following method can be used: using a liquid composition comprising a specific fluorinated copolymer, a polymerization solvent for the specific fluorinated copolymer, and a piperidinyl-containing compound used in polymerization of the specific fluorinated copolymer, the total content of ethylbenzene and mixed xylenes is adjusted to fall within the above range. The polymerization solvent preferably comprises at least one of ethylbenzene and mixed xylenes, and more preferably comprises both.

[0130] Furthermore, as another embodiment of the method for producing the present liquid composition, there is mentioned a method in which a specific fluorinated copolymer, ethylbenzene, mixed xylenes and a piperidinyl group-containing compound are mixed.

[0131] The coating comprises the liquid composition.

[0132] The content of the present liquid composition in the present coating material can be appropriately set, for example, so that the content of the specific fluorinated copolymer in the present coating material becomes 5 to 70 mass % based on the total mass of the present coating material.

[0133] The present coating material may further contain a coating solvent. Here, the coating solvent is preferably a solvent other than ethylbenzene and mixed xylenes.

[0134] Specific examples of the coating solvent include ketone solvents, ester solvents, hydrocarbon solvents (excluding ethylbenzene and mixed xylenes), alcohol solvents, glycol ether solvents, and glycol ester solvents.

[0135] Specific examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and diacetone alcohol.

[0136] Specific examples of the ester solvent include ethyl acetate and butyl acetate.

[0137] Specific examples of the hydrocarbon solvent include hexane, heptane, and cyclohexane.

[0138] Specific examples of alcoholic solvents include butanol.

[0139] Specific examples of the glycol ether-based solvent include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monopropyl ether.

[0140] Specific examples of glycol ester solvents include 1-methoxypropyl-2-acetate.

[0141] Two or more coating solvents may be used in combination.

[0142] The content of the coating solvent can be appropriately set so that the content of the specific fluorinated copolymer in the present coating falls within the above-mentioned range.

[0143] The present coating material may contain components other than those mentioned above. Examples of such components include additives.

[0144] Examples of the additives include a curing agent, a curing catalyst, a resin other than the above-mentioned specific fluorinated copolymer (such as a (meth)acrylic resin, a polyurethane resin, and an epoxy resin), a colorant (such as a dye, an organic pigment, an inorganic pigment, and a bright pigment using metal or mica), an ultraviolet absorber, a matting agent, a leveling agent, a surface conditioner, a degassing agent, a filler, a thickener, a dispersant, a surfactant, an antistatic agent, a rust inhibitor, a silane coupling agent, an antifouling agent, a low-fouling treatment agent, a plasticizer, and an adhesive.

[0145] The substrate with a coating film of the present invention comprises: a substrate and a coating film formed of the present coating material disposed on the substrate. In this specification, the coating film formed of the present coating material is also referred to as "the present coating film."

[0146] Specific examples of the material of the substrate include inorganic substances, organic substances, and organic-inorganic composite materials.

[0147] Specific examples of inorganic substances include concrete, natural stone, glass, and metals (iron, stainless steel, aluminum, aluminum alloy, copper, brass, titanium, etc.).

[0148] Specific examples of organic substances include plastics, rubber, adhesives, and wood.

[0149] Specific examples of the organic-inorganic composite material include fiber-reinforced plastics, resin-reinforced concrete, and fiber-reinforced concrete.

[0150] The substrate may be subjected to a known surface treatment (chemical conversion treatment, etc.) and may have a resin layer (polyester resin layer, acrylic resin layer, silicone resin layer, etc.) formed by applying a primer or the like on the surface of the substrate.

[0151] The thickness of the present coating film is preferably 1 to 200 μm, more preferably 10 to 100 μm, from the viewpoint of achieving better light resistance of the substrate having the present coating film.

[0152] The method for producing a substrate with the present coating film is to apply the present coating material to the substrate to form the present coating film. The present coating film can be formed by applying the present coating material to the substrate, drying it as needed, and then curing it by heating.

[0153] This coating can be applied directly to the surface of the substrate, or it can be applied after the surface of the substrate has been subjected to a known surface treatment (substrate treatment, etc.). Furthermore, it can also be applied to a primer layer formed on the substrate. In addition, this coating can also be applied to articles having the above-mentioned substrate.

[0154] Examples of the coating method include spray coating, blade coating, flow coating, bar coating, spin coating, dip coating, screen printing, gravure printing, die coating, inkjet coating, curtain coating, and methods using a brush or a doctor blade.

[0155] The method for producing a substrate with the present coating preferably includes a step of drying after coating to remove the solvent. The drying temperature is usually 0 to 50°C, and the drying time is usually 1 minute to 2 weeks.

[0156] When the coating material contains a curing agent, it is preferably cured by heating after application. The curing temperature is usually 50 to 300° C., and the curing time is usually 1 minute to 24 hours.

[0157] Example

[0158] The present invention is described in detail below with examples. Examples 1 to 6 are examples, and Examples 7 to 9 are comparative examples. However, the present invention is not limited to these examples. It should be noted that the amounts of each component in the tables below are based on mass unless otherwise specified.

[0159] [Example 1]

[0160] Into a stainless steel pressure-resistant reactor with an internal volume of 2500 ml equipped with a stirrer, 8.6 g of a piperidyl-containing compound (manufactured by BASF, trade name "Tinuvin 292", a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (mass ratio 3:1)), 17 g of hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd., trade name "KW500", particle size 45 μm or less: 38%, 4 The reactor was then heated to 65°C. The reactor was then heated to 65°C. A mixture of 383 g of ethylbenzene, 467 g of mixed xylenes (a mixture of o-xylene, m-xylene, and p-xylene), 196 g of ethyl vinyl ether (hereinafter referred to as EVE), 123 g of 4-hydroxybutyl vinyl ether (hereinafter referred to as HBVE), and 198 g of cyclohexyl vinyl ether (hereinafter referred to as CHVE) was added, and dissolved oxygen in the solution was removed by degassing with nitrogen. Furthermore, 629 g of chlorotrifluoroethylene (hereinafter referred to as CTFE) was introduced into the reactor, and the temperature was raised. Heating was continued until the reactor temperature reached 65°C. Then, 2 ml of a 20% xylene solution of tert-butyl peroxypivalate (hereinafter referred to as PBPV) was added to the reactor to initiate the reaction.

[0161] Afterwards, a 20% xylene solution of PBPV was intermittently added to the reactor as a free radical polymerization initiator to allow polymerization to proceed. After polymerization began, a total of 50 ml of 20% xylene solution of PBPV was intermittently added to the reactor. After 16 hours, the reactor was water-cooled to terminate the reaction.

[0162] After cooling the reaction solution to room temperature (23°C, the same applies hereinafter), unreacted monomers were purged, and the insoluble components of the resulting reaction solution were removed by filtration. The concentration was then adjusted to a solids concentration of 60% by mass to obtain Solution A-1 containing Fluorinated Copolymer 1. The composition of Solution A-1 is shown in Table 1.

[0163] The composition of the fluorinated copolymer 1 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit=50 / 25 / 10 / 15 (molar ratio).

[0164] [Example 2]

[0165] In a 2500 ml stainless steel pressure-resistant reactor equipped with a stirrer, 20 g of Tinuvin 292, 20 g of hydrotalcite, 373 g of ethylbenzene, 306 g of mixed xylenes (a mixture of o-xylene, m-xylene, and p-xylene), 118 g of HBVE, and 453 g of CHVE were placed. Dissolved oxygen in the solution was removed by degassing with nitrogen. Furthermore, 536 g of CTFE was introduced into the reactor, and the temperature was raised. Heating was continued until the reactor temperature reached 65°C. Then, 2 ml of a 5% PBPV xylene solution was added to the reactor to initiate the reaction.

[0166] While maintaining the reaction rate, additional monomers (110 g of CTFE, 93 g of CHVE, and 24 g of HBVE) were continuously added to the reactor. Polymerization was also allowed to proceed by intermittently adding a 5% xylene solution of PBPV as a free radical polymerization initiator. After the start of polymerization, the total amount of 5% xylene solution of PBPV intermittently added to the reactor was 55 ml. After 16 hours, the reactor was water-cooled to terminate the reaction.

[0167] After the reaction solution was cooled to room temperature, unreacted monomers were purged, and the insoluble components of the resulting reaction solution were removed by filtration. The concentration was then adjusted to a solids concentration of 60% by mass to obtain Solution A-2 containing the fluorinated copolymer 2. The composition of Solution A-2 is shown in Table 1.

[0168] The composition of the fluorinated copolymer 2 is as follows: CTFE unit / HBVE unit / CHVE unit=50 / 11 / 39 (molar ratio).

[0169] [Example 3]

[0170] In a 2500 ml stainless steel pressure-resistant reactor equipped with a stirrer, 5.5 g of Tinuvin 292, 5.5 g of hydrotalcite, 437 g of ethylbenzene, 404 g of mixed xylenes (a mixture of o-xylene, m-xylene, and p-xylene), 206 g of 2-ethylhexyl vinyl ether (hereinafter referred to as 2EHVE), 92 g of HBVE, and 289 g of CHVE were placed. Dissolved oxygen in the solution was removed by degassing with nitrogen. Furthermore, 512 g of CTFE was introduced into the reactor, and the temperature was raised. Heating was continued until the reactor temperature reached 65°C. Then, 4 ml of a 25% xylene solution of PBPV was added to the reactor to initiate the reaction.

[0171] Afterwards, a 25% xylene solution of PBPV was intermittently added to the reactor as a free radical polymerization initiator to allow polymerization to proceed. After polymerization began, a total of 49 ml of the 25% xylene solution of PBPV was intermittently added to the reactor. After 16 hours, the reactor was water-cooled to terminate the reaction.

[0172] After the reaction solution was cooled to room temperature, unreacted monomers were purged, and the insoluble components of the resulting reaction solution were removed by filtration. The concentration was then adjusted to a solids concentration of 60% by mass to obtain a solution A-3 containing the fluorinated copolymer 3. The composition of solution A-3 is shown in Table 1.

[0173] The composition of the fluorinated copolymer 3 is as follows: CTFE unit / HBVE unit / CHVE unit / 2EHVE=50 / 9 / 26 / 15 (molar ratio).

[0174] [Example 4]

[0175] In a 2500 ml stainless steel pressure-resistant reactor equipped with a stirrer, 8.6 g of Tinuvin 292, 17 g of hydrotalcite, 425 g of ethylbenzene, 425 g of mixed xylenes (a mixture of o-xylene, m-xylene, and p-xylene), 196 g of EVE, 123 g of HBVE, and 198 g of CHVE were placed. Dissolved oxygen in the solution was removed by degassing with nitrogen. Furthermore, 629 g of CTFE was introduced into the reactor, and the temperature was raised. Heating was continued until the reactor temperature reached 65°C. Then, 2 ml of a 20% xylene solution of PBPV was added to the reactor to initiate the reaction.

[0176] Afterwards, a 20% xylene solution of PBPV was intermittently added to the reactor as a free radical polymerization initiator to allow polymerization to proceed. After polymerization began, a total of 50 ml of 20% xylene solution of PBPV was intermittently added to the reactor. After 16 hours, the reactor was water-cooled to terminate the reaction.

[0177] After the reaction solution was cooled to room temperature, unreacted monomers were purged, and the insoluble components of the resulting reaction solution were removed by filtration. 10.7 g of succinic anhydride was added to the filtered solution, and the mixture was heated until the temperature in the reactor reached 90°C. Then, 4.6 g of triethylamine was added and maintained for 3 hours. After the reaction solution was cooled to room temperature, the concentration was adjusted to a solids concentration of 60% by mass, yielding Solution A-4 containing fluorinated copolymer 4. The composition of Solution A-4 is shown in Table 1.

[0178] The composition of fluorinated copolymer 4 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit = 50 / 25 / 10 / 15 (molar ratio). It should be noted that in Example 4, at least a portion of the hydroxyl groups of the HBVE units reacted with succinic anhydride to be converted into carboxyl groups.

[0179] [Examples 5~8]

[0180] Except for changing the type and composition of the solvents used as shown in Table 1, the same procedure as in Example 1 was carried out to obtain solution A-5 containing fluorinated copolymer 5, solution A-6 containing fluorinated copolymer 6, solution A-7 containing fluorinated copolymer 7, and solution A-8 containing fluorinated copolymer 8. The compositions of solutions A-5 to A-8 are shown in Table 1.

[0181] The composition of the fluorinated copolymer 5 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit=51 / 25 / 10 / 14 (molar ratio).

[0182] The composition of the fluorinated copolymer 6 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit=50 / 25 / 10 / 15 (molar ratio).

[0183] The composition of the fluorinated copolymer 7 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit=51 / 25 / 9 / 15 (molar ratio).

[0184] The composition of the fluorinated copolymer 8 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit=51 / 25 / 10 / 14 (molar ratio).

[0185] [Example 9]

[0186] In a 2500 ml stainless steel pressure-resistant reactor equipped with a stirrer, 252 g of ethylbenzene, 425 g of mixed xylenes (a mixture of o-xylene, m-xylene, and p-xylene), 168 g of ethanol, 206 g of EVE, 129 g of HBVE, 203 g of CHVE, and 11 g of potassium carbonate were placed. Dissolved oxygen in the solution was removed by degassing with nitrogen. Furthermore, 660 g of CTFE was introduced into the reactor, and the temperature was raised. Heating was continued until the reactor temperature reached 65°C. Then, 5 ml of a 2% PBPV xylene solution was added to the reactor to initiate the reaction.

[0187] Afterwards, a 2% xylene solution of PBPV was intermittently added to the reactor as a free radical polymerization initiator to allow polymerization to proceed. After the start of polymerization, the total amount of 2% xylene solution of PBPV intermittently added to the reactor was 79 ml. After 16 hours, the reactor was water-cooled to terminate the reaction.

[0188] After the reaction solution was cooled to room temperature, 0.1 g of hydroquinone monomethyl ether (hereinafter also referred to as HQMME) was added, unreacted monomers were purged, and the insoluble components of the resulting reaction solution were removed by filtration. The concentration was then adjusted to a solids concentration of 60% by mass to obtain solution A-9 containing fluorinated copolymer 9. The composition of solution A-9 is shown in Table 1.

[0189] The composition of the fluorinated copolymer 9 is as follows: CTFE unit / EVE unit / HBVE unit / CHVE unit=50 / 25 / 10 / 15 (molar ratio).

[0190] [Table 1]

[0191]

[0192] [Manufacturing of paint]

[0193] 17 parts by mass of the solution of each example, 40 parts by mass of titanium oxide (Ti-Pure (registered trademark) R960 manufactured by DuPont), and butyl acetate in such an amount that the total amount of the fluorinated copolymer and the titanium oxide amount was 50% by mass of the total amount were mixed, and stirred in a rocking mill for 1 hour to prepare a mill base.

[0194] Next, 37 parts by mass of the obtained millbase, 30 parts by mass of the fluorinated copolymer in the solution of each example, 2 parts by mass of a 1 / 10000 diluted xylene solution of dibutyltin dilaurate, and butyl acetate in such an amount that the total amount of the fluorinated copolymer and titanium oxide was 50% by mass of the total amount were mixed, and the mixture was stirred again in a rocking mill for 30 minutes to prepare a main agent.

[0195] Next, 100 parts by mass of the main agent was mixed with an isocyanate curing agent (Desmodur (registered trademark) N3300 manufactured by Bayer AG) as a curing agent (6.1 parts by mass for Examples 1 and 4 to 9, 5.4 parts by mass for Example 2, and 4.7 parts by mass for Example 3) to prepare a coating material corresponding to each example.

[0196] [Production of a substrate with a coating]

[0197] The obtained coating was applied to one side of a chromate-treated aluminum plate using an applicator and then maintained in an atmosphere at 80°C for 1 hour. After heating, the aluminum plate with a coating layer corresponding to each example was placed and cooled to room temperature (23°C) to obtain an aluminum plate with a coating film (cured film) having a thickness of 40 μm.

[0198] [Evaluation of light resistance of coating films]

[0199] The light resistance of the resulting coating was evaluated using a Q-LAB SE model. The test conditions were based on Cycle 3 of ASTM G154-04 (light resistance test). Light resistance was evaluated based on the 60° gloss retention of the coating after 10,000 hours of exposure to the tester, according to the following criteria. The evaluation results are shown in Table 2.

[0200] The 60° gloss retention rate is the ratio (unit: %) of the 60° gloss value of the coating film after the light resistance test, with the 60° gloss value of the coating film before the light resistance test being 100%. The gloss retention rate is measured and calculated in accordance with JIS K 5600-4-7:1999 (ISO 2813:1994).

[0201] <Evaluation Criteria>

[0202] ○ (Excellent): 80% or more

[0203] △(Good): 70% or more and less than 80%

[0204] ×(Not allowed): Less than 70%

[0205] [Table 2]

[0206]

[0207] As shown in Table 2, it was confirmed that coating films excellent in light resistance were obtained using the coating materials obtained using the present liquid composition (Examples 1 to 6).

[0208] It should be noted that the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2023-037644 filed on March 10, 2023 are incorporated herein by reference and are incorporated as the disclosed contents of the specification of the present invention.

Claims

1. A fluorinated copolymer liquid composition comprising: A fluorine-containing copolymer having chlorotrifluoroethylene-based units and vinyl ether-based units; piperidinyl-containing compounds; ethylbenzene; and Mixed xylenes comprising at least two of o-xylene, m-xylene and p-xylene, The mass ratio of the ethylbenzene content to the mixed xylene content is 0.3 to 3.

0.

2. The fluorinated copolymer liquid composition according to claim 1, wherein The mixed xylenes include all of o-xylene, m-xylene and p-xylene.

3. The fluorinated copolymer liquid composition according to claim 2, wherein The piperidinyl-containing compound is a compound represented by the following formula (N1): In the formula (1), R 11 ~R 14 Each independently represents an alkyl group, a cycloalkyl group, a substituted alkyl group, an aryl group or an aralkyl group having 1 to 18 carbon atoms, and R 11 With R 12 , or R 13 With R 14 optionally forming an aliphatic ring having 3 to 6 carbon atoms, R 15 is a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group, an aralkyl group or a cycloalkyl group, R 16 It is a hydrogen atom, a hydroxyl group, an alkyl group, a substituted alkyl group, an aryl group, an aralkyl group, an ester bond-containing group, an amino group-containing group, a 2,2,6,6-tetrasubstituted piperidinyl group-containing group, or a group formed by combining two or more of these groups.

4. The fluorinated copolymer liquid composition according to claim 2, wherein The content of the piperidinyl group-containing compound is 0.1 to 2 mass % based on the total mass of the fluorinated copolymer liquid composition.

5. The fluorinated copolymer liquid composition according to claim 2, wherein The mass ratio of the content of the piperidinyl group-containing compound to the content of the ethylbenzene is 0.001 to 0.

2. 6 . A coating comprising the fluorinated copolymer liquid composition according to claim 1 .

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