Paint composition, its cured product, and coated articles using the same

Abstract

To provide a coating composition that can impart flame retardancy to a combustible substrate such as wood and ensures good transparency and moisture resistance of a coating layer.SOLUTION: A coating composition includes (A) an organopolysiloxane with a unit ratio represented by the formula (1): (R13SiO1 / 2)a(R22SiO)b(R31SiO3 / 2)c(SiO2)d(OR4)e (1) (R1-R3 each represent an alkyl group or the like optionally substituted with a hydrogen atom or at least one amino group or the like, but at least some of them are alkyl groups or the like substituted with amino groups, R4 represents a hydrogen atom or an alkyl group, a represents 0-0.5, b represents 0-0.5, c represents 0.2-1.0, d represents 0-0.5, e represents 0-3.0, satisfying a+b+c+d=1), (B) at least one flame retardant selected from phosphorous, boron, magnesium, aluminum, nitrogen, antimony and halogen compounds and (C) inorganic filler.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a coating composition, a cured product thereof, a coated article using the same, and more specifically, to a flame-retardant paint for use on combustible substrates such as wood.

Background Art

[0002] In recent years, from the viewpoints of carbon fixation and effective utilization of domestic resources, the use of wood in buildings has been promoted. However, wood is a combustible substrate, and its use in applications where flame-retardant performance is required is greatly restricted. Among these, various techniques for imparting flame retardancy to wood have been studied.

[0003] For example, in Patent Document 1, flame retardancy has been successfully imparted by impregnating wood with a high concentration of a flame retardant such as boric acid. However, in this system, there is a problem that the flame retardant adsorbed on the wood is eluted or deliquesced by moisture in the air, greatly impairing the aesthetics.

[0004] In Patent Document 2, it has been reported that after impregnating wood with a boron compound, applying a siloxane compound to the wood surface can suppress the elution of the chemical agent. However, when this method is used, there are reported cases where the boron compound dissolves due to the moisture contained in the wood itself, causing efflorescence at the interface between the coating film and the wood. In addition, this method requires many steps such as impregnation of the flame retardant, drying, and surface coating, and an increase in manufacturing cost is inevitable.

[0005] In Patent Document 3, a technique for imparting flame retardancy to wood without impregnating the wood with a flame retardant by applying a primer component mainly composed of silica to the wood surface and then applying water glass thereon has been reported. However, the above method requires applying water glass after applying the primer paint to the wood surface, which requires a lot of time for manufacturing. In addition, water glass is known to have low curability and water resistance, and also has a problem of reacting with wood and discoloring, and there are many problems for practical application.

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a coating composition capable of imparting flame retardancy to a combustible base material such as wood, having good transparency and moisture resistance of the coating film, a cured product thereof, and a coated article using the same.

Means for Solving the Problems

[0008] As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by using a coating composition containing a predetermined amino group - modified organopolysiloxane, a predetermined flame retardant, and an inorganic filler, and have completed the present invention.

[0009] That is, the present invention provides 1. (A) Organopolysiloxane composed of unit ratios represented by the following formula (1): 100 parts by mass (R 1 3SiO 1 / 2 ) a (R 2 2SiO) b (R 3 1SiO 3 / 2 ) c (SiO2) d (OR 4 ) e (1) (In the formula, R 1 , R 2 and R 3Each of these independently represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may be substituted with a hydrogen atom or one or more amino groups, epoxy groups, acid anhydride groups, maleimide groups, vinyl groups, allyl groups, acrylic groups, methacrylic groups, or heterocyclic groups. 1 , R 2 and R 3 At least a portion of these are alkyl groups with 1 to 20 carbon atoms substituted with an amino group, aryl groups with 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups with 7 to 20 carbon atoms substituted with an amino group, R 4 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, where a is between 0 and 0.5, b is between 0 and 0.5, c is between 0.2 and 1.0, d is between 0 and 0.5, and e is between 0 and 3.0, and a+b+c+d=1. (B) One or more flame retardants selected from phosphorus-based, boron-based, magnesium-based, aluminum-based, nitrogen-based, antimony-based, and halogen-based compounds: 50 to 300 parts by mass, and (C) Inorganic filler: 25-150 parts by mass Paint compositions containing, 2. The above R 1 , R 2 and R 3 A paint composition having 1, wherein the total number of alkyl groups having 1 to 20 carbon atoms substituted with an amino group, aryl groups having 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups having 7 to 20 carbon atoms substituted with an amino group is 50 mol% or more relative to the total number of silicon atoms in formula (1), 3. A paint composition in which the (B) flame retardant is one or more selected from phosphates and polyphosphates. 4. The three paint compositions wherein the (B) flame retardant comprises one or more selected from water-soluble phosphates and polyphosphates, and one or more selected from water-insoluble phosphates and polyphosphates. 5. The (C) inorganic filler is a paint composition containing glass fibers, 6. The (C) inorganic filler comprises a paint composition containing a phyllosilicate. 7. The (C) inorganic filler comprises 5 paint compositions containing phyllosilicate. 8. A paint composition having a ratio [(B)+(C)] / (A) of the total mass of component (B) and component (C) to the mass of component (A) of 1.0 to 4.5. 9. Furthermore, (D) a paint composition comprising a siloxane-based leveling agent, 10. One paint composition containing 20% ​​by mass or more of water relative to the entire paint composition, 11. Cured product of any of the paint compositions from 1 to 10, 12. A coated article having a cured film of any of the coating compositions 1 to 10 applied directly or via one or more other layers to at least one surface of a substrate. 13. The amount of the cured coating is 0.1 to 2.0 kg / m² relative to the substrate. 2 The 12 covering articles, 14. Covering articles 12 in which the base material is lumber or wood laminated material. To provide. [Effects of the Invention]

[0010] The paint composition of the present invention contains an amino group-modified organopolysiloxane with excellent compatibility with flame retardants, resulting in good paint film appearance and moisture resistance when applied as a coating. Furthermore, when the coating film obtained from the paint composition of the present invention is burned, the flame retardants, organopolysiloxanes, and inorganic fillers contained in the coating film undergo ceramicization to form a fire-resistant layer and / or heat-insulating layer, preventing the combustion of flammable substrates such as wood. Due to these effects, the paint composition of the present invention makes it possible to achieve both moisture resistance, flame retardancy, and transparency, which have been difficult to achieve conventionally. Furthermore, the paint composition of the present invention can impart flame retardancy to flammable substrates such as wood by being applied to the surface of wood, and compared to conventional flame-retardant substrates impregnated with flame retardants, it is possible to impart flame retardancy to flammable substrates such as wood more easily. In addition, it is possible to make materials flame-retardant through on-site application, which is expected to greatly expand the freedom of design and / or construction of wooden buildings. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below. [1] Paint composition The paint composition of the present invention contains the following components (A) to (C).

[0012] (A) Organopolysiloxane (A) Component is an organopolysiloxane composed of the unit ratio shown in formula (1) below. In formula (1) below, unless otherwise specified, (R 1 3SiO 1 / 2 The unit expressed as (R) is called the M unit, (R 2 The unit represented as 2SiO) is called the D unit, (R 3 SiO 3 / 2 The unit represented by (SiO2) is called the T unit, and the unit represented by (SiO2) is called the Q unit.

[0013] (R 1 3SiO 1 / 2 ) a (R 2 2SiO) b (R 3 1SiO 3 / 2 ) c (SiO2) d (OR 4 ) e (1)

[0014] In equation (1), R 1 , R 2 and R 3 Each of these R represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, which may be independently substituted with a hydrogen atom or one or more amino groups, epoxy groups, acid anhydride groups, maleimide groups, vinyl groups, allyl groups, acrylic groups, methacrylic groups, or heterocyclic groups. 1 , R 2 and R 3At least some of these are alkyl groups with 1 to 20 carbon atoms substituted with an amino group, aryl groups with 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups with 7 to 20 carbon atoms substituted with an amino group.

[0015] The alkyl group having 1 to 20 carbon atoms can be linear, branched, or cyclic. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-decyl, cyclopentyl, and cyclohexyl groups. Methyl or ethyl groups are preferred because they enhance the flame retardancy of the paint composition. Examples of aryl groups with 6 to 20 carbon atoms include phenyl and naphthyl. Aralkyl groups with 7 to 20 carbon atoms include benzyl and phenethyl groups. Examples of heterocyclic groups include piperidinyl, pyridinyl, pyrrolyl, and thienyl groups.

[0016] As described above, in equation (1), R 1 , R 2 and R 3 At least a portion of these are alkyl groups having 1 to 20 carbon atoms substituted with an amino group, aryl groups having 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups having 7 to 20 carbon atoms substituted with an amino group. Preferred amino group-substituted groups include γ-aminopropyl groups and N-(2-aminoethyl)-3-aminopropyl groups. (A) Considering the solubility of component in water, the flame retardant component and its affinity with the substrate, R 1 , R 2 and R 3 Of these, the total number of alkyl groups having 1 to 20 carbon atoms substituted with an amino group, aryl groups having 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups having 7 to 20 carbon atoms substituted with an amino group is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 65 mol% or more, relative to the total number of silicon atoms in formula (1).

[0017] Note, R 1 , R 2 and R 3 Of these, preferred substituents other than those substituted with an amino group are methyl groups and ethyl groups, which have a small number of carbon atoms in the flammable alkyl chain, with methyl groups being more preferred.

[0018] In equation (1), R 4 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Specific examples of alkyl groups having 1 to 8 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, and n-octyl groups. Among these, from the standpoint of flame retardancy of the paint composition. 4 A hydrogen atom is preferred.

[0019] a is a number between 0 and 0.5, b is a number between 0 and 0.5, c is a number between 0.2 and 1.0, and d is a number between 0 and 0.5, and a + b + c + d = 1. e is a number between 0 and 3.0, and a number between 0.1 and 2.0 is preferred from the viewpoint of water solubility of organopolysiloxane. If e exceeds 3.0, the film-forming properties of the paint composition and the moisture resistance of the coating film may deteriorate.

[0020] The organopolysiloxane component (A) has undergone some degree of condensation, making it easier to form a network and immobilize on the substrate. In addition, it has the advantage of having fewer alkoxy groups, which are sources of flammable gases, compared to monomer components (such as silane coupling agents) that do not contain siloxane bonds (Si-O-Si bonds), resulting in less reduction in flame retardancy.

[0021] The monomer component that does not contain the siloxane bond is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 10% by mass or less, and still more preferably 1% by mass or less, relative to the organopolysiloxane of component (A). The ratio of the monomer component that does not contain the above siloxane bond to the organopolysiloxane component is: 29 It can be determined from the signal and integral ratio in the Si-NMR (nuclear magnetic resonance) spectrum. 29 In Si-NMR, for example, in the case of a trifunctional siloxane (in T units), the number of silicon atoms forming siloxane bonds can be determined by examining the ratios of (T0) to (T3) shown below. Since the detection magnetic field generally increases in the order of T3 > T2 > T1 > T0, the T0 component represents silicon atoms derived from the silane coupling agent, and the others represent silicon atoms derived from the siloxane. Therefore, the ratio of monomer (silane coupling agent) component to organopolysiloxane component can be determined from the ratio of the integral values ​​of each peak.

[0022] [ka] (In the formula, R represents an organic group, and X represents a hydrogen atom or an organic group.)

[0023] The organopolysiloxane of component (A) can be produced by hydrolysis condensation of the monomer components of each constituent unit under acid or base catalysis.

[0024] Examples of Q-unit monomers include tetramethoxysilane, tetraethoxysilane, tetra(n-propoxy)silane, tetra(i-propoxy)silane, tetra(n-butoxy)silane, alkali silicate, and activated silicic acid obtained by cation exchange of alkali silicate.

[0025] Examples of T-unit monomers include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltriisopropoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3 Examples include 4-epoxycyclohexyl)ethyltrimethoxysilane, γ-chloropropyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, perfluorooctylethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, γ-isocyanatetopropyltrimethoxysilane, and γ-isocyanatetopropyltriethoxysilane. Among these, considering the solubility of the resulting siloxane in water and its affinity for wood and flame retardant components, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, γ-isocyanatetopropyltrimethoxysilane, γ-isocyanatetopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane are preferred, and γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltriethoxysilane are more preferred.

[0026] Examples of D-unit monomers include dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, methylpropyldimethoxysilane, methylpropyldiethoxysilane, diisopropyldimethoxysilane, phenylmethyldimethoxysilane, vinylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane. Among these, γ-aminopropylmethyldiethoxysilane and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane are preferred, considering their solubility in water and affinity with wood and flame retardant components.

[0027] Examples of monomers in M ​​units include trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, n-propyldimethylmethoxysilane, n-propyldiethylmethoxysilane, iso-propyldimethylmethoxysilane, iso-propyldiethylmethoxysilane, propyldimethylethoxysilane, n-butyldimethylmethoxysilane, n-butyldimethylethoxysilane, n-hexyldimethylmethoxysilane, n-hexyldimethylethoxysilane, n-pentyldimethylmethoxysilane, n-pentyldimethylethoxysilane, n-hexyldimethylmethoxysilane, n-hexyl Examples include dimethylethoxysilane, n-decyldimethylmethoxysilane, n-decyldimethylethoxysilane, trimethylsilanol, triethylsilanol, n-propyldimethylsilanol, n-propyldiethylsilanol, iso-propyldimethylsilanol, iso-propyldiethylsilanol, propyldimethylsilanol, n-butyldimethylsilanol, n-hexyldimethylsilanol, n-pentyldimethylsilanol, n-decyldimethylsilanol, γ-aminopropyldimethylmethoxysilane, and N-(2-aminoethyl)-3-aminopropyldimethylmethoxysilane. Among these, γ-aminopropyldimethylmethoxysilane and N-(2-aminoethyl)-3-aminopropyldimethylmethoxysilane are preferred, considering the solubility of the resulting organopolysiloxane in water and its affinity with the substrate and flame retardant components.

[0028] Since M units and D units have two or more Si-C bonds and are easily combustible, the content of M units or D units in the organopolysiloxane of component (A) is 50 mol% or less. That is, in formula (1) above, a is a number from 0 to 0.5, preferably a number from 0 to 0.2, and more preferably a number from 0 to 0.1. Furthermore, b is a number between 0 and 0.5, preferably between 0 and 0.2, and more preferably between 0 and 0.1.

[0029] T units have one Si-C bond and are less flammable than D and M units. Therefore, good flame retardancy is achieved by including 20 mol% or more of T units in the total constituent units of the organopolysiloxane of component (A). In other words, in formula (1) above, c is a number between 0.2 and 1.0, preferably between 0.5 and 1.0, and more preferably between 0.6 and 1.0.

[0030] Q units do not contain Si-C bonds and have low flammability, which helps to suppress the decrease in flame retardancy caused by combustion originating from Si-C bonds. On the other hand, because Q units have many crosslinking points and are highly reactive, from the viewpoint of compatibility with flame retardant components and film formation, the amount of Q units in the organopolysiloxane of component (A) is in the range of 0 to 50 mol%, that is, d is a number from 0 to 0.5, preferably 0.1 to 0.4, and more preferably 0.3 to 0.4.

[0031] (A) The ratio of each constituent unit in the component is, for example, 29 This can be confirmed using a known method that employs the ratio of the chemical shift and integral value of the Si-NMR signal.

[0032] (A) The content of component (A) is preferably 5 to 40% by mass of the total paint composition, and more preferably 10 to 20% by mass. When the content is 5% by mass or more, the film-forming properties, transparency, and moisture resistance of the coating film are improved. When the content is 40% by mass or less, the flame retardancy of the coating film is improved. (A) Component may be used alone or in combination of multiple types.

[0033] (B) Flame retardant (B) Component is one or more flame retardants selected from phosphorus-based, boron-based, magnesium-based, aluminum-based, nitrogen-based, antimony-based, and halogen-based compounds. Examples of phosphorus compounds include organophosphorus compounds, phosphoric acid, phosphate esters, and phosphate salts. Specific examples include diammonium hydrogen phosphate, ammonium dihydrogen phosphate, diguanidine phosphate, ammonium polyphosphate, hydrophobized ammonium polyphosphate, guanylurea phosphate, polycarbamate polyphosphate, and melamine phosphate. Examples of boron-based compounds include organoboron compounds, boric acid, borax, boron oxide, borate esters, and borate salts. Examples of magnesium-based compounds include magnesium hydroxide and magnesium oxide. Examples of aluminum-based compounds include aluminum hydroxide. Examples of nitrogen-based compounds include ammonium sulfate, ammonium carbonate, ammonium bicarbonate, and melamine cyanurate. Examples of antimony compounds include antimony trioxide. Examples of halogenated compounds include zinc chloride.

[0034] Among these, phosphorus-based compounds and boron-based compounds are preferred as flame retardants for use in the compositions of the present invention, and it is more preferable to use phosphates and polyphosphates, which form a carbonized layer in a short time and easily ensure flame retardant performance. In particular, it is preferable to use a combination of water-soluble phosphates and / or polyphosphates and water-insoluble phosphates and / or polyphosphates, as this improves the flame retardancy and moisture resistance of the coating film without impairing its transparency.

[0035] The amount of component (B) is 50 to 300 parts by mass, preferably 75 to 250 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). If the amount is less than 50 parts by mass, the flame retardancy of the coating film may be insufficient, and if it exceeds 300 parts by mass, the film-forming ability, transparency, and moisture resistance of the coating film may be inferior. (B) Component may be one type alone or multiple types in combination.

[0036] (C) Inorganic filler (C) As the inorganic filler, known general inorganic fillers can be used, for example, inorganic fillers containing Group 13 elements, Group 14 elements (excluding carbon), first-series transition elements, second-series transition elements, third-series transition elements, lanthanides, etc. Examples of inorganic fillers containing Group 13 elements include oxides derived from aluminum, boron, indium, etc., with alumina being particularly preferred. Examples of inorganic fillers containing Group 14 elements (excluding carbon) include oxides and salts derived from silicon, tin, etc., with silica being preferred. Examples of inorganic fillers containing first-series transition elements include oxides derived from titanium, manganese, zinc, etc., and these oxides can also be used as light-absorbing materials for specific wavelengths. Examples of inorganic fillers containing second-series transition elements include oxides derived from yttrium, zirconium, etc., and these oxides can also be used as light-absorbing and fluorescent materials for specific wavelengths. Examples of inorganic fillers containing third-series transition elements include oxides derived from hafnium, tantalum, and the like. Inorganic fillers containing lanthanides include oxides derived from lanthanum, cerium, praseodymium, neodymium, terbium, dysprodium, ytterbium, etc. These oxides can also be used as light-absorbing and fluorescent materials for specific wavelengths. Furthermore, a compound formed by the chemical bonding of two or more of these types can be used.

[0037] There are no particular restrictions on the shape of the inorganic filler; various shapes such as spherical, hollow spherical, porous, plate-shaped, needle-shaped, and fibrous can be used. Among these, fibrous inorganic fillers are preferred because they have a high effect in suppressing cracks in the ceramic layer formed after combustion, resulting in particularly good flame retardancy.

[0038] In particular, the inorganic fillers used in the present invention are preferably inorganic oxides or silicates containing elements such as silicon, boron, and aluminum, which become ceramic when burned and form a fire-resistant layer or a heat-insulating layer. In particular, it is preferable to use silicon oxide-containing fillers such as silica or glass fibers in combination with ferrosilicates such as clay, as this results in better flame retardancy.

[0039] The amount of component (C) is 25 to 150 parts by mass per 100 parts by mass of the organopolysiloxane of component (A) above, with 50 to 150 parts by mass being preferred. If the amount is less than 25 parts by mass, the flame retardancy of the coating film may be insufficient, and if it exceeds 150 parts by mass, the film-forming ability and transparency of the coating film may be poor. (C) Component may be used alone or in combination of multiple types.

[0040] The total content of components (A) to (C) above in the entire coating composition of the present invention is preferably 30% by mass or more, and more preferably 40% by mass or more.

[0041] In the coating composition of the present invention, the ratio of the total mass of components (B) and (C) to the mass of component (A) [(B)+(C)] / (A) is preferably 1.0 to 4.5, more preferably 1.2 to 4.0, and even more preferably 1.5 to 2.5. When the ratio is 1.0 or higher, flame retardancy is good, and when it is 4.5 or lower, the moisture resistance, film-forming properties, and transparency of the coating film are good.

[0042] (D) Leveling agent The paint composition of the present invention may also contain (D) a leveling agent. As leveling agents, well-known and common types such as acrylic, vinyl, silicone, and fluorine-based leveling agents can be used. Among these, silicone-based leveling agents having a siloxane structure in the main chain are preferred because they enhance the flame retardancy of the paint composition.

[0043] When using component (D), the amount added is preferably 1 to 10 parts by mass, and more preferably 3 to 5 parts by mass, per 100 parts by mass of the organopolysiloxane of component (A). Within this range, it is possible to improve film formation while maintaining the flame retardancy and transparency of the coating film. (D) Component may be used alone or in combination of multiple types.

[0044] (E) Solvent The paint composition of the present invention may also contain a solvent in addition to the above components (A) to (D). While there are no particular limitations on the solvent, alcohol and water are preferred, with water being more preferred from the standpoint of environmental protection and availability.

[0045] When water is used as a solvent, specific fresh water such as tap water, industrial water, well water, natural water, rainwater, distilled water, and deionized water can be used, but deionized water is particularly preferred. Deionized water can be produced using a pure water purifier (for example, Organo Corporation's product name "FW-10", Merck Millipore KGaA's product name "Direct-QUV3", etc.).

[0046] When using a solvent, the amount added is preferably 20 to 80% by mass, and more preferably 30 to 60% by mass, relative to the total paint composition of the present invention. When the solvent is present at 20% by mass or more relative to the total composition, the fluidity and workability of the paint are improved, and when it is present at 80% by mass or less relative to the total composition, the concentration of the active ingredients in the paint increases, making it easier to form a thick paint film.

[0047] The paint composition of the present invention may contain a curing catalyst for the purpose of accelerating the curing reaction. The type, amount, and method of adding the curing catalyst can be determined using known methods and conditions depending on the type of composition. In particular, if the curable composition contains a component that hardens through a chemical reaction in the presence of a catalyst, it is preferable that the curable composition contains a curing catalyst. Examples of curing catalysts include basic compounds such as lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methylate, sodium propionate, potassium propionate, sodium acetate, potassium acetate, sodium formate, potassium formate, trimethylbenzylammonium hydroxide, tetramethylammonium hydroxide, tetramethylammonium acetate, n-hexylamine, tributylamine, diazabicycloundecene (DBU), and dicyandiamide; metal-containing compounds such as tetraisopropyl titanate, tetrabutyl titanate, titanium acetylacetonate, aluminum triisobutoxide, aluminum triisopropoxide, tris(acetylacetonate)aluminum, diisopropoxy(ethylacetoacetate)aluminum, aluminum perchlorate, aluminum chloride, cobalt octylate, cobalt acetylacetonate, iron acetylacetonate, tin acetylacetonate, dibutyltin octylate, and dibutylsuzurate; and acidic compounds such as p-toluenesulfonic acid and trichloroacetic acid. Among these, sodium propionate, sodium acetate, sodium formate, trimethylbenzylammonium hydroxide, tetramethylammonium hydroxide, tris(acetylacetonate)aluminum, and diisopropoxy(ethylacetoacetate)aluminum are particularly preferred, and metal-containing compounds such as aluminum-based catalysts, titanium-based catalysts, and tin-based catalysts containing organic ligands are especially preferred.

[0048] The coating composition of the present invention may contain additives that exert additional effects, to the extent that they do not hinder the effects of the present invention. Examples of additives include penetrating agents. Penetrating agents have the effect of promoting the impregnation of flame-retardant components into materials selected from wood (including bamboo), paper, woven fabrics, nonwoven fabrics, and resins. Specific examples of penetrating agents include monoalcohols such as methanol, ethanol, propanol, butanol, pentanol, and hexanol; diols such as ethylene glycol and propylene glycol; triols such as glycerin; polyols such as algitols (also called glycitol) with 3 to 11 carbon atoms, cellulose derivatives, and cellulose nanofibers; polyphenols; and surfactants that have the effect of reducing interfacial tension. Among these, ethylene glycol is preferred. When using a penetrating agent, the amount added is not particularly limited, but is preferably 0.05 to 20% by mass, more preferably 0.5 to 2% by mass, relative to the total paint composition.

[0049] In addition to penetrating agents, other additives include ultraviolet absorbers, termite repellents, antioxidants, dyes, and pigments. These additives may be used individually or in combination of multiple types.

[0050] The paint composition of the present invention can be manufactured by mixing the above components (A) to (C), and optionally components (D), (E), and other components. The mixing method for each component can be appropriately selected from known methods and is not particularly limited. As equipment to be used for mixing, for example, a mixer, a shaker, an ultrasonic homogenizer, a high-pressure homogenizer, a bead mill, a ball mill, and the like can be used. Furthermore, to promote the dissolution and dispersion of each component, the mixing operation may be performed by heating, to the extent that it does not impair the effects of the present invention.

[0051] [2] Cured products and coated articles By curing the coating composition of the present invention, a cured product (cured film) can be obtained. For example, by applying the coating composition of the present invention to a substrate to be flame-retardant and drying it to form a cured film, a flame-retardant coated article can be obtained.

[0052] Examples of base materials subject to flame retardation include lumber products, logs, plywood, LVL (Laminated Veneer Lumber), glued laminated timber, CLT (Cross-Laminated Timber), laminated veneer lumber (LVL), high-strength engineered wood lumber (LSL), laminated veneer board (LVB), laminated veneer sandwich (LVS), and parallel strands. Examples include wood-based materials such as lumber (PSL), medium-density fiberboard (MDF), structural panels (oriented strand board (OSB)), particleboard, and fiberboard; paper such as Japanese paper, fusuma paper, and Western-style paper; woven fabrics such as cotton cloth, polyester woven fabric, and PET fiber cloth; nonwoven fabrics such as polyester nonwoven fabric; and resins such as SBR (styrene-butadiene rubber) latex, NBR (acrylonitrile-butadiene rubber) latex, polyvinyl acetate, polyvinyl alcohol, ABS (acrylonitrile-butadiene styrene) resin, EAA (ethylene-acrylic acid copolymer) resin, polyethylene film, polyurethane resin, PET (polyethylene terephthalate) film, and polyethylene sheets. In particular, the coating composition of the present invention can significantly improve flame retardancy when applied to wood, and is suitable for use on building materials such as lumber, laminated wood, and CLT.

[0053] In this case, the coating layer may be formed on only one surface of the substrate or on all surfaces. For example, in the case of a plate-shaped substrate, the coating layer may be formed on at least one surface. Furthermore, substrates whose surfaces have been treated, specifically those treated with chemical conversion treatment, corona discharge treatment, plasma treatment, or acid or alkaline solutions, as well as decorative plywood in which the substrate body and surface layer are coated with different types of paints, can also be used.

[0054] Alternatively, a coating of the paint composition of the present invention may be applied to the surface of a substrate on which other functional layers have been formed in advance. Other functional layers include primer layers, rust-preventive layers, gas barrier layers, waterproofing layers, and heat-shielding layers, and one or more of these layers may be pre-formed on the substrate.

[0055] Furthermore, the coated article of the present invention may be coated with one or more layers, such as a hard coat layer, rust-preventive layer, gas barrier layer, waterproof layer, heat-shielding layer, anti-fouling layer, photocatalytic layer, or antistatic layer, on the surface on which the cured film made of the above-mentioned coating composition is formed, or on the opposite surface. Examples of materials constituting these layers include alkyd resins, acrylic resins, urethane resins, acrylic silicone resins, fluororesins, silicone resins, epoxy resins, vinylidene chloride copolymer resins, vinyl chloride resins, etc. (whether water-based or solvent-based). The above layers can be applied as a coating liquid or laminated by bonding them together as pre-formed films via an adhesive or the like.

[0056] The conditions for coating and drying the coating composition of the present invention on a substrate can be appropriately set depending on the type and shape of the substrate, and specific conditions can be appropriately selected from known conditions.

[0057] The method for applying the paint composition can be appropriately selected from known methods, and various application methods such as brush application, spraying, dipping, flow coating, roll coating, curtain coating, spin coating, and knife coating can be used. The coating composition of the present invention is a composition that can be cured at a temperature of approximately 0 to 40°C, preferably 5 to 35°C, but it is more preferable that it can form a cured film after 24 hours at 25°C. Furthermore, to shorten the curing time, heating may be performed within a temperature range that does not adversely affect the substrate, etc.

[0058] The amount of cured film applied is not particularly limited, but it is generally 0.1 to 2.0 kg / m² relative to the substrate. 2 It is preferable to cover it in such a way that the amount is 0.5 to 1.5 kg / m². 2 It is more preferable to coat the surface in such a manner. Within this range, flame retardancy and the appearance of the coating film will be better. In order to achieve the above coverage amount, the coating should be applied so that the amount of solid content of the paint composition is within the above range relative to the substrate. [Examples]

[0059] The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, % represents mass%, and parts represents parts by mass.

[0060] [Examples 1-6, Comparative Examples 1-10] [1] Preparation of paint composition Paint compositions were prepared by mixing the following components in the amounts listed in Tables 1 and 2 below. In Tables 1 and 2, the active ingredient concentration refers to the sum of the solid content of component (A), comparative component, and component (B-1) in 100 parts by mass of the paint composition, the amount of component (B-2), the amount of component (B-3), the amount of component (C), and the amount of component (D). For example, in Example 1, the amount of active ingredient in component (A-1), which is a 30% by mass aqueous solution, is 65.4 × 0.3 = 19.6 parts by mass, and the amount of active ingredient in component (B-1), which is a 50% by mass aqueous solution, is 19.6 × 0.5 = 9.8 parts by mass. The active ingredient concentration in Example 1 is 19.6 + 9.8 + 5 + 10 = 44.4 ≈ 44% by mass. Furthermore, the mass ratios of the active ingredients in Tables 1 and 2 are the mass ratios based on the solid content of each component. For example, in Example 1, the value is calculated by setting the solid content of component (A-1), which is 19.6 parts by mass, to 100.

[0061] (A) component A-1: 30% by mass aqueous solution of an amino group-containing organopolysiloxane (where a=0, b=0, c=0.7, d=0.3, e=0.7, R in formula (1) above) 3 =Methyl group, N-(2-aminoethyl)-3-aminopropyl group, R 4 = Hydrogen atom, amine substitution amount (relative to total silicon atoms) = 61 mol%)

[0062] [Comparison components] A'-2: Aqueous dispersion of acrylic resin prepared in Comparative Synthesis Example 1 below A'-3: Sodium silicate No. 3 (40% by mass aqueous solution of sodium silicate, manufactured by Nippon Chemical Industrial Co., Ltd.) A'-4: 30% by mass aqueous solution of alkyl group-containing organopolysiloxane (where a=0, b=0, c=1, d=0, e=1.0, R in formula (1) above) 3 =methyl group, R 4 = Hydrogen atom, amine substitution amount (relative to total silicon atoms) = 0 mol%)

[0063] [Comparative Synthesis Example 1] In a five-necked flask equipped with a stirrer, reflux condenser, thermometer, dropping device, and nitrogen inlet tube, 200 parts by mass of deionized water and 6.0 parts by mass of a non-reactive emulsifier (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.: Hytenol NF0825: anionic) were added. While purging the flask with nitrogen, the temperature was raised to 80°C, then 1.0 part by mass of potassium persulfate was added. Next, a mixture of 190 parts by mass of methyl methacrylate, 250 parts by mass of butyl acrylate, 10 parts by mass of acrylic acid, 220 parts by mass of deionized water, and 30.0 parts by mass of the above non-reactive emulsifier, which had been mixed by stirring in a separate container, was continuously added dropwise over 3.5 hours. After that, the mixture was aged at 80°C for 2 hours while continuing to stir, then a mixture of 2.7 parts by mass of deionized water and 0.3 parts by mass of a 70% aqueous solution of tert-butyl hydroperoxide was added to the reactor, and then a mixture of 9.7 parts by mass of deionized water and 0.3 parts by mass of sodium erythorbate was continuously added dropwise over 5 minutes. Subsequently, the mixture was aged at 80°C for 2 hours while continuing to stir. After cooling to room temperature, 4.0 parts by mass of a 25% by mass aqueous ammonia solution was added to adjust the pH to 9.0, obtaining an aqueous dispersion of acrylic resin A'-2. The acrylic resin content in the dispersion was 49.8% by mass, and the volume-average particle size of the emulsion was 144 nm.

[0064] (B) Component B-1: Nonnen W2-50 (50% by mass aqueous solution of phosphorus-nitrogen-based flame retardant, manufactured by Maruzen Yuka Kogyo Co., Ltd.) B-2: Taien K (water-insoluble ammonium polyphosphate powder, manufactured by Taiheiyo Kogyo Co., Ltd.) B-3: Taien E (non-water-soluble ammonium polyphosphate powder, manufactured by Taiheiyo Kogyo Co., Ltd.)

[0065] (C) Component C-1: EPH80M-01N (Glass fiber, manufactured by Nippon Electric Glass Co., Ltd.) C-2: SYLOID W 500 (Silica, manufactured by W.R. Grace Japan Co., Ltd.) C-3: BENTONE-EW NA (Hectolite Clay, manufactured by Elementis Specialties, Inc.)

[0066] (D) Component D-1: BYK3450 (Polyether-modified polydimethylsiloxane, manufactured by BIC Chemie Japan Co., Ltd.)

[0067] [Evaluation of paint stability] The paint stability was evaluated according to the following criteria. In this evaluation, the sedimentation of non-water-soluble flame retardant and filler components, which are originally solid, was not considered a deterioration of paint stability if it could be used without problems after shaking. The results are shown in Table 1. ○: When each component is blended, no gelation or solid precipitation occurs, and the mixture remains liquid. ×: If gelation or solid precipitation occurs when each component is combined.

[0068] [2] Preparation and evaluation of covered wood For cedar wood (air-dry specific gravity 0.27-0.49) cut into 100mm x 100mm x 20mm pieces and dried at 115℃ for 24 hours, each of the paint compositions from the examples and comparative examples was applied with a solid content coating amount of approximately 1 kg / m². 2 The wood was coated and cured at a temperature of 23±2℃ and a relative humidity of 50±5% to maintain a constant mass. The following tests were performed on the prepared coated cedar wood (coated wood).

[0069] (1) Paint film transparency The transparency of the coating film was evaluated according to the following criteria. The results are shown in Table 1. ◎: No cloudiness, and the wood grain of the base material can be seen through the coating. ○: There is a slight cloudiness, but the wood grain of the base material can be seen through the coating. ×: The wood grain of the base material cannot be seen through the coating. (2) Moisture resistance Each piece of wood was subjected to five cycles of wet-drying, consisting of 40°C, 90% RH (24 hours) followed by 60°C, forced-air drying (24 hours). After cooling at 20°C, 60% RH for 24 hours, the surface condition of the coating was observed and evaluated according to the following criteria. The results are shown in Table 1. ○: No signs of bleaching, deliquescence, discoloration, etc. ×: Whitening, deliquescence, discoloration, etc. may be observed. (3) Flame retardant Radiant heat intensity of 50 kW / m for each type of wood 2 A cone calorimeter test (ISO-5660-1) was performed using the specified parameters, and flame retardancy was evaluated according to the following criteria. ◎: Heat output when heated for 10 minutes is 8 (MJ / m²). 2 ) If below ○: Heat output when heated for 5 minutes is 8 (MJ / m²). 2 ) If below ×: Heat output when heated for 5 minutes is 8 (MJ / m²) 2 If it is greater than (4) Surface cracks Radiant heat intensity of 50 kW / m for each type of wood 2 A cone calorimeter test (ISO-5660-1) was performed, and the presence or absence of cracks on the heated surface was evaluated according to the following criteria. ○: When there are no obvious cracks on the heated surface. ×: When there are obvious cracks on the heated surface.

[0070] [Table 1]

[0071] [Table 2]

[0072] As shown in Table 1, in Examples 1 to 6, where the coating composition satisfying the requirements of the present invention was applied to wood, the coating film exhibited good moisture resistance and transparency, and showed flame retardancy that met the standards for flame-retardant to semi-non-combustible wood due to its low heat output during combustion. Furthermore, no cracks were observed on the burning surface in Examples 1 to 6, which satisfy the requirements of the present invention. From the above, it is believed that in a coating composition that satisfies the requirements of the present invention, by combining a siloxane compound, a flame retardant, and an inorganic filler, it is possible to form a robust ceramic layer during combustion, and that the flame retardancy of the wood is greatly improved by its fire-resistant and heat-insulating effects. On the other hand, as shown in Table 2, in Comparative Examples 1, 3, and 5, which do not contain component (A) of the present invention and do contain a flame retardant and an inorganic filler, the stability of the liquid and the appearance of the coating film are significantly deteriorated. In addition, as in Comparative Example 4, when water glass is applied alone, the flame retardancy and transparency are good, but the moisture resistance is poor, and it can be seen that the cedar wood discolored and the coating film deliquesced after the moisture resistance test. As in Comparative Example 2, when a paint without a siloxane structure is used, or as in Comparative Examples 6-9, when a paint with a small amount of flame retardant or inorganic filler is used, it can be seen that it burns violently and its flame retardancy deteriorates. Furthermore, as in Comparative Example 10, when a paint with too much flame retardant or inorganic filler is used, it can be seen that the film-forming properties and transparency of the coating film deteriorate significantly.

Claims

1. (A) Organopolysiloxane in the unit ratio represented by the following formula (1): 100 parts by mass (R 1 3 SiO 1 / 2 ) a (R 2 2 SiO) b (R 3 1 SiO 3 / 2 ) c (SiO 2 ) d (OR 4 ) e (1) (In the formula, R 1 , R 2 and R 3 Each of these independently represents a C1-C20 alkyl group, a C6-C20 aryl group, or a C7-C20 aralkyl group, which may be substituted with a hydrogen atom or one or more amino groups, epoxy groups, acid anhydride groups, maleimide groups, vinyl groups, allyl groups, acrylic groups, methacrylic groups, or heterocyclic groups, but the above R 1 , R 2 and R 3 At least a portion of these are alkyl groups having 1 to 20 carbon atoms substituted with an amino group, aryl groups having 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups having 7 to 20 carbon atoms substituted with an amino group, and the total number of alkyl groups having 1 to 20 carbon atoms substituted with an amino group, aryl groups having 6 to 20 carbon atoms substituted with an amino group, or aralkyl groups having 7 to 20 carbon atoms substituted with an amino group among R1, R2, and R3 is 50 mol% or more of the total number of silicon atoms in formula (1), and R 4 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, where a is between 0 and 0.2, b is between 0 and 0.5, c is between 0.5 and 1.0, d is between 0 and 0.5, and e is between 0 and 3.0, and a + b + c + d = 1. (B) One or more flame retardants selected from phosphorus-based, boron-based, magnesium-based, aluminum-based, nitrogen-based, antimony-based, and halogen-based compounds: 50 to 300 parts by mass, and (C) Inorganic filler: Contains 25 to 150 parts by mass, A paint composition in which component (B) comprises one or more selected from phosphates and polyphosphates, and component (C) comprises one or more selected from silica and glass fibers.

2. The paint composition according to claim 1, wherein b is a number between 0 and 0.

2.

3. The paint composition according to claim 1, wherein d is a number between 0.1 and 0.

4.

4. The paint composition according to claim 1, wherein the (B) flame retardant comprises one or more selected from water-soluble phosphates and polyphosphates, and one or more selected from non-water-soluble phosphates and polyphosphates.

5. The paint composition according to claim 1, wherein the (C) inorganic filler comprises glass fibers.

6. The paint composition according to claim 1, wherein the (C) inorganic filler comprises a phyllosilicate.

7. The paint composition according to claim 5, wherein the (C) inorganic filler comprises a phyllosilicate.

8. The paint composition according to claim 1, wherein the ratio of the total mass of component (B) and component (C) to the mass of component (A) [(B) + (C)] / (A) is 1.0 to 4.

5.

9. Furthermore, the paint composition according to claim 1, further comprising (D) a siloxane-based leveling agent.

10. The paint composition according to claim 1, comprising 20% ​​by mass or more of water relative to the entire paint composition.

11. A cured product of the paint composition according to any one of claims 1 to 10.

12. A coated article comprising a cured film of a coating composition according to any one of claims 1 to 10, applied directly to at least one surface of a substrate or via one or more other layers.

13. The amount of the cured coating is 0.1 to 2.0 kg / m² relative to the substrate. 2 The coated article according to claim 12.

14. The coated article according to claim 12, wherein the base material is lumber or wood laminate.

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