Vinyl acetate-based copolymer and fire-resistant paint composition comprising same

Abstract

The present invention relates to: a vinyl acetate-based copolymer having excellent initial water resistance and excellent fire resistance; and a fire-resistant paint composition comprising same.

Description

Vinyl acetate copolymer and fire-resistant paint composition containing the same

[0001] The present invention relates to a vinyl acetate copolymer having excellent initial water resistance and fire resistance and a fire-resistant paint composition comprising the same.

[0002]

[0003] Fire-resistant paints protect buildings and other structures from fire, forcibly blocking or delaying the spread of high-temperature heat in the event of a fire, providing time for firefighting and rescue efforts. Among fire-resistant paints, foaming paints are those that, when exposed to heat, foam their dry coating layer to form a carbonized layer. While the carbonized layer ultimately combusts, it takes time for combustion to occur, so they protect the conductor (e.g., steel frame) from flame and combustion heat for a certain period of time, reducing the effects of these. Foaming paints are generally oil-based, but oil-based paints can produce an unpleasant odor due to the organic solvents they contain, and they dry more slowly than water-based paints due to their thick film nature.

[0004] To address these issues, Korean Patent No. 10-0377832 discloses a water-based, foamable fire-resistant paint. This water-based fire-resistant paint composition offers excellent water resistance and, because it is halogen-free, does not emit harmful gases. However, its fire resistance is limited to only one hour. Furthermore, conventional fire-resistant paints suffer from poor water resistance.

[0005] Accordingly, there is a need for the development of an eco-friendly fire-resistant paint that has excellent fire resistance and water resistance of the coating film.

[0006]

[0007] The present invention provides an environmentally friendly water-based fire-resistant paint composition having excellent fire resistance and excellent water resistance of the coating film.

[0008]

[0009] The present invention provides a vinyl acetate copolymer polymerized from a monomer mixture comprising a vinyl acetate monomer, an alkyl-modified vinyl acetate monomer, a phosphoric acid-containing acrylic monomer, and a polyvalent double bond-containing monomer, and a fire-resistant paint composition comprising the same.

[0010]

[0011] The present invention provides an environmentally friendly water-based fire-resistant paint composition having excellent fire resistance and excellent water resistance of the coating film. The fire-resistant paint composition according to the present invention exhibits fire resistance of 2 hours or more, while also exhibiting excellent durability and water resistance. The fire-resistant paint composition of the present invention has excellent initial water resistance as well as complete drying of the coating film, and has the advantage of enabling off-site (shop) coating due to its fast drying speed, shortening the coating period even in on-site coating, and facilitating film thickness management. In addition, the water-based fire-resistant paint composition according to the present invention is environmentally friendly because it does not contain organic solvents.

[0012]

[0013] The present invention will be described in detail below. However, it is not limited to the following description, and each component may be modified or selectively mixed as needed. Therefore, it should be understood that all modifications, equivalents, and alternatives included within the spirit and technical scope of the present invention are included.

[0014] As used herein, the “glass transition temperature” is measured by a conventional method known in the art, and can be measured, for example, by differential scanning calorimetry (DSC). Functional values ​​such as “acid value” are measured by a conventional method known in the art, and can be measured, for example, by titration. “Particle size (D50)” is measured by a conventional method known in the art, and can be measured, for example, by laser light scattering (LLS). “Viscosity” is measured by a conventional method known in the art, and can be measured, for example, using a Brookfield viscometer at room temperature (25°C).

[0015]

[0016] <Vinyl acetate copolymer>

[0017] In the refractory coating composition of the present invention, the copolymer serves as a main resin, which imparts durability to the dried and cured coating film at room temperature, and when exposed to high temperature heat, changes the coating film into a fluid state, allowing the coating film to expand and foam appropriately when gas is generated, and serves as the skeleton of the foamed carbon layer. In addition, the copolymer serves to improve the water resistance of the coating film.

[0018] The above vinyl acetate copolymer is a copolymer polymerized from a monomer mixture comprising a vinyl acetate monomer, an alkyl-modified vinyl acetate monomer, a phosphoric acid-containing acrylic monomer, and a polyvalent double bond-containing monomer. The copolymer can be prepared from a resin composition comprising the monomer mixture, an initiator, and an aqueous solvent. The resin composition may further include additives commonly used in the relevant technical field, such as an emulsifier, a protective colloid, and a buffer.

[0019] The above monomer mixture includes a vinyl acetate monomer. The vinyl acetate monomer may be included in an amount of 50 to 85 wt%, for example, 60 to 80 wt%, based on the total weight of the monomer mixture. If the content of the vinyl acetate monomer is below the above-mentioned range, foamability and economic efficiency may be reduced, and if it exceeds the above-mentioned range, water resistance may be reduced.

[0020] The above monomer mixture includes an alkyl-modified vinyl acetate monomer. The fire-resistant paint composition of the present invention can exhibit superior water resistance compared to a conventional water-based vinyl acetate resin by using a copolymer in which an alkyl-modified vinyl acetate monomer is copolymerized.

[0021] The above alkyl-modified vinyl acetate monomer may be a compound represented by the following chemical formula 1.

[0022] [Chemical Formula 1]

[0023]

[0024] In the above chemical formula 1,

[0025] R 1 , R 2 are hydrocarbon groups having 1 to 15 carbon atoms, which are the same or different from each other.

[0026] Since water is used in water-based paints, there is a problem that the water resistance is reduced when the resin and water come into contact and cause a hydrolysis reaction. The copolymer containing the alkyl-modified vinyl acetate monomer of the above chemical formula 1 has an alkyl-modified structure, i.e., a substituent R 1 , R 2 The steric effect prevents the acetate group (OC=O) from coming into contact with water, making the hydrolysis reaction difficult, and as a result, the water resistance of the coating can be greatly improved. In addition, by minimizing defects such as holes in the dried coating, the foaming performance can be improved by preventing bubbles from escaping during foaming.

[0027] The above alkyl-modified vinyl acetate monomer is R in the above chemical formula 1. 1 , R 2 Alkyl groups having 1 to 15 carbon atoms, which are the same or different from each other, for example, R 1 and R 2 At least one of which is an alkyl group having 3 to 13 carbon atoms, another example is R 1 and R 2 A compound in which at least one of the monomers is an alkyl group having 6 to 10 carbon atoms may be used. For example, the alkyl-modified vinyl acetate monomer may be vinyl neononanoate, vinyl neodecanoate, or vinyl neoundecanoate.

[0028] The above alkyl-modified vinyl acetate monomer may be included in an amount of 10 to 40 wt%, for example, 15 to 30 wt%, based on the total weight of the monomer mixture. If the content of the above alkyl-modified vinyl acetate monomer is less than the above-mentioned range, water resistance may be reduced, and if it exceeds the above-mentioned range, foaming properties and economic efficiency may be reduced.

[0029] The above monomer mixture includes a phosphoric acid-containing acrylic monomer. The fire-resistant paint composition of the present invention can further improve water resistance and foaming properties compared to a conventional water-based vinyl acetate resin by using a copolymer in which a phosphoric acid-containing acrylic monomer is copolymerized.

[0030] The above phosphoric acid-containing acrylic monomer may be a compound represented by the following chemical formula 2.

[0031] [Chemical Formula 2]

[0032]

[0033] In the above chemical formula 2,

[0034] R is ethylene oxide or propylene oxide,

[0035] n is an integer from 0 to 10.

[0036] The above-mentioned phosphoric acid-containing acrylic monomer can improve adhesion to a substrate due to the carboxyl group included in the structure, and can improve water resistance and coating strength by generating cross-linking power with pigments such as TiO2 included in the paint.

[0037] As the above-mentioned phosphoric acid-containing acrylic monomer, a compound in which R in the above-mentioned chemical formula 2 is ethylene oxide or propylene oxide, and n is an integer from 0 to 10, or an integer from 2 to 8 can be used. For example, the above-mentioned phosphoric acid-containing acrylic monomer may be a phosphoalkyl (meth)acrylate such as phosphoethyl (meth)acrylate, phosphopropyl (meth)acrylate, phosphobutyl (meth)acrylate, salts thereof, and mixtures thereof; a phosphoalkoxy (meth)acrylate such as phosphoethylene glycol (meth)acrylate, phosphodiethylene glycol (meth)acrylate, phosphotriethylene glycol (meth)acrylate, phosphopropylene glycol (meth)acrylate, phosphodipropylene glycol (meth)acrylate, phosphotripropylene glycol (meth)acrylate, salts thereof, and mixtures thereof. In addition, commercially available products (Solvay) such as SIPOMER PAM-100, SIPOMER PAM-200, and SIPOMER PAM-300 can be used as the above-mentioned phosphoric acid-containing acrylic monomer.

[0038] The above-mentioned phosphoric acid-containing acrylic monomer may be included in an amount of 0.5 to 5 wt%, for example, 1 to 3 wt%, based on the total weight of the monomer mixture. If the content of the above-mentioned phosphoric acid-containing acrylic monomer is less than the above-mentioned range, water resistance and foaming properties may be reduced, and if it exceeds the above-mentioned range, synthetic stability and economic feasibility may be reduced.

[0039] The above monomer mixture includes a monomer having a polyvalent double bond. When a copolymer in which the above polyvalent double bond-containing monomer is copolymerized is used, chain bonds between molecules occur, resulting in superior water resistance compared to conventional water-based vinyl acetate resins.

[0040] The above-mentioned polyvalent double bond-containing monomer may be a compound represented by the following chemical formula 3.

[0041] [Chemical Formula 3]

[0042]

[0043] In the above chemical formula 3,

[0044] R is a hydrocarbon group having 1 to 15 carbon atoms.

[0045] As the above-mentioned polyvalent double bond-containing monomer, a compound in which R in the above chemical formula 3 is an alkylene group having 1 to 15 carbon atoms, for example, an alkylene group having 1 to 10 carbon atoms, can be used. For example, as the above-mentioned polyvalent double bond-containing monomer, a (meth)acrylate-based monomer having a double bond, for example, allyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, or a mixture thereof can be used.

[0046] The above-mentioned polyvalent double bond-containing monomer may be included in an amount of 0.01 to 0.5 wt%, for example, 0.01 to 0.08 wt%, based on the total weight of the monomer mixture. If the content of the polyvalent double bond-containing monomer is less than the above-mentioned range, water resistance may be reduced, and if it exceeds the above-mentioned range, foaming property may be reduced.

[0047] The above monomer mixture may further include an acrylic monomer. As the acrylic monomer, ethyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, methacrylic acid (MAA) or a mixture thereof may be used.

[0048] The acrylic monomer may be included in an amount of 4 to 20 wt%, for example, 8 to 15 wt%, based on the total weight of the monomer mixture. If the content of the acrylic monomer is less than the above-mentioned range, water resistance may be reduced due to hydrophilization, and if it exceeds the above-mentioned range, synthetic stability may be reduced due to differences in reactivity.

[0049] The vinyl acetate copolymer according to the present invention is an aqueous resin having a glass transition temperature of -30 to 60°C and a film formation temperature of 0 to 30°C. The solid content of the vinyl acetate copolymer is 40 to 60%, for example, 45 to 55%, the particle size (D50) is 200 to 500 nm, for example, 300 to 400 nm, the viscosity (25°C) is 200 to 800 cPs, for example, 300 to 600 cPs, and the pH may be 2.5 to 5.5, for example, 3.5 to 4.5. By using the vinyl acetate copolymer as a main resin, the fire-resistant paint composition of the present invention has good durability such as chemical resistance, weather resistance, and flexibility, and in particular, can exhibit excellent foaming properties and water resistance.

[0050] If the glass transition temperature of the vinyl acetate copolymer is below the above-mentioned range, the hardness may decrease, and if it exceeds the above-mentioned range, the film-forming property may be poor, which may cause cracks to occur. If the film-forming temperature of the vinyl acetate copolymer is below the above-mentioned range, the hardness may decrease, and if it exceeds the above-mentioned range, the film-forming property may be poor, which may cause a large amount of organic solvent to be used, which may reduce environmental friendliness. If the solid content of the vinyl acetate copolymer is below the above-mentioned range, the solvent (water) content in the paint may increase, which may slow down the drying speed, and if it exceeds the above-mentioned range, the viscosity may increase, which may reduce the synthetic stability of the resin. If the particle size (D50) of the vinyl acetate copolymer is less than the above-mentioned range, water resistance may be reduced due to an excessive amount of emulsifier, and if it exceeds the above-mentioned range, the stability of the resin particles may be deteriorated, causing precipitation. If the viscosity (25°C) of the vinyl acetate copolymer is less than the above-mentioned range, dispersion may be deteriorated during pigment dispersion, resulting in deterioration of the appearance properties of the coating film. If it exceeds the above-mentioned range, the synthetic stability of the resin may be deteriorated. If the pH of the vinyl acetate copolymer is out of the above-mentioned range, the stability of the resin may be deteriorated due to hydrolysis, resulting in deterioration of storage stability.

[0051]

[0052] <Refractory paint composition>

[0053] The fire-resistant paint composition of the present invention comprises a vinyl acetate copolymer, a foaming agent, and an aqueous solvent. The fire-resistant paint composition of the present invention may further comprise, as necessary, a thickener, a catalyst, a carbonizing agent, a pigment, a reinforcing agent, and additives commonly used in the relevant technical field. Examples of such additives include flame retardants, film forming agents, defoaming agents, dispersants, preservatives, plasticizers, antifreeze agents, pH regulators, and the like.

[0054]

[0055] vinyl acetate copolymer

[0056] The fire-resistant coating composition of the present invention uses the aforementioned vinyl acetate copolymer as its main resin. Conventional fire-resistant coatings suffer from poor water resistance, leading to problems such as deformation of the coating's appearance upon prolonged exposure to moisture. Furthermore, the loss of refractory components results in reduced fire-resistant performance upon exposure to fire. The fire-resistant coating composition of the present invention can address these issues by incorporating the vinyl acetate copolymer.

[0057] The vinyl acetate copolymer may be included in an amount of 5 to 35 wt%, for example 10 to 30 wt%, or as another example 20 to 30 wt%, based on the total weight of the fire-resistant paint composition. If the content of the vinyl acetate copolymer is less than the above-mentioned range, the durability of the dried and cured coating film may be poor, and if it exceeds the above-mentioned range, the foaming rate may be reduced and the coating film may peel off during foaming, preventing it from exhibiting normal fire-resistant performance.

[0058]

[0059] blowing agent

[0060] The refractory paint composition of the present invention includes a foaming agent. The foaming agent decomposes at high temperatures and reacts with a carbonizing agent and a catalyst to form a carbonized layer. During the reaction, the foaming agent generates gas, which enables the carbonized layer to foam appropriately.

[0061] The above-mentioned foaming agent may be any conventional component known in the relevant technical field without limitation. For example, a nitrogen-containing foaming agent may be used. The nitrogen-containing foaming agent can maintain the insulating effect by foaming a carbonized layer formed by a carbonizing agent and a catalyst while releasing nitrogen-containing gas, such as ammonia gas, generated by thermal decomposition of the compound at high temperatures. At this time, an appropriate decomposition temperature is required so that the nitrogen-containing foaming agent can foam after the carbonized layer is formed from the dried film of the refractory paint.

[0062] Non-limiting examples of usable nitrogen-containing blowing agents include melamine, dicyandiamide, ammeline, melam, urea, ureido melamine, glycine, and the like. The aforementioned ingredients may be used alone or in combination of two or more.

[0063] The above-mentioned foaming agent may be included in an amount of 1 to 15 wt%, for example, 5 to 10 wt%, based on the total weight of the fire-resistant paint composition. If the content of the foaming agent is less than the above-mentioned range, the amount of gas generated may be small, resulting in a low foaming rate. If the content exceeds the above-mentioned range, it may be difficult to form a uniform carbonized layer due to excessive gas ejection, and the strength of the foamed coating film may be reduced due to foaming, resulting in a concomitant reduction in fire-resistant performance.

[0064]

[0065] Aqueous solvent

[0066] The fire-resistant paint composition of the present invention includes an aqueous solvent. The aqueous solvent functions to adjust the paint's viscosity and impart fluidity. By replacing organic solvents with an aqueous solvent, the present invention improves the working environment and air quality, and provides an environmentally friendly paint. Water can be used as the aqueous solvent.

[0067] The content of the above-mentioned aqueous solvent may be a residual amount satisfying 100 wt% of the fire-resistant paint composition. For example, the aqueous solvent may be included in an amount of 5 to 30 wt%, for example, 7 to 20 wt%, based on the total weight of the fire-resistant paint composition. If the content of the above-mentioned aqueous solvent is less than the above-mentioned range, paint manufacturing may become difficult, and if it exceeds the above-mentioned range, workability may deteriorate due to the excessive amount of solvent, and the content of flame retardants, etc. for forming a carbon layer may be relatively reduced, resulting in a lower foaming rate and poor fire resistance performance.

[0068]

[0069] thickener

[0070] The refractory paint composition of the present invention may include a thickener. The thickener serves to impart appropriate viscosity and fluidity to the paint. The thickener may be amide wax, cellulose wax, or a mixture thereof.

[0071] For example, amide wax can be used as the thickener. The amide wax imparts hydrophilicity to the paint and allows hydrogen bonds within the paint to interact, resulting in thixotropic properties. Furthermore, it prevents the paint film from flowing during application and prevents pigment components from settling during paint storage. Water-soluble polyamide wax can be used as the amide wax. Water-soluble polyamide wax has excellent workability and storability, and is easy to use in paint manufacturing.

[0072] The solid content of the above amide wax may be 10 to 30%, and the acid value may be 1 to 20 mgKOH / g, for example, 1 to 12.5 mgKOH / g. When the properties of the amide wax satisfy the above-mentioned range, productivity and workability can be further improved. In particular, when the acid value of the above amide wax is less than the above-mentioned range, the solubility property is lowered, so that the stirring time during paint production increases, which increases the production time and may lower productivity, and when it exceeds the above-mentioned range, the thickening property is lowered, so that the flow resistance during painting work is lowered, which may lower the workability.

[0073] The content of the thickener may be 1 to 10 wt%, for example 1 to 5 wt%, based on the total weight of the refractory paint composition. If the content of the thickener is less than the above-mentioned range, flow resistance may be poor, resulting in reduced workability. If the content of the thickener is more than the above-mentioned range, viscosity may be excessively increased, making spray or brush painting difficult.

[0074]

[0075] catalyst

[0076] The fire-resistant paint composition of the present invention may include a catalyst. The catalyst promotes the reaction of a carbonizing agent and a foaming agent by emitting gas through thermal decomposition at high temperatures, and at the same time, participates in the reaction to form a carbonized layer. As the catalyst, any conventional component known in the relevant technical field may be used without limitation, and an acid catalyst may be used as an example. The acid catalyst generates ammonia, a foaming gas, during thermal decomposition, and hydrogen ions (H) of a carbonizing agent to generate a carbonized layer. + ) acts as a donor.

[0077] Non-limiting examples of usable catalysts include primary ammonium phosphate, secondary ammonium phosphate, ammonium phosphite, melamine phosphate, dimelamine phosphate, and melamine pyrophosphate.

[0078] Examples include pyrophosphate, melamine polyphosphate, tricrecyl phosphate, trichloroalkylphosphate, ammonium polyphosphate, monoammonium phosphate, and nitropolyphosphate. The above-mentioned components may be used alone or in combination of two or more.

[0079] The content of the catalyst may be 15 to 35 wt%, for example 20 to 30 wt%, based on the total weight of the fire-resistant paint composition. If the content of the catalyst is less than the above-mentioned range, the reaction with the carbonizing agent and the foaming agent may not proceed smoothly, resulting in reduced formation of a carbonized layer. If the content of the catalyst is more than the above-mentioned range, the foaming effect of the carbonized layer may be inhibited, resulting in a lower foaming rate, which may result in lower fire-resistant performance.

[0080]

[0081] carbonizer

[0082] The fire-resistant paint composition of the present invention may include a carbonizing agent. The carbonizing agent forms a carbonized layer that exhibits fire-resistant performance by reacting with a foaming agent at high temperatures. As the carbonizing agent, any conventional component known in the art may be used without limitation. Non-limiting examples of usable carbonizing agents include pentaerythritol, dipentaerythritol, tripentaerythritol, starch, phenolformaldehyde resin, sugar, polyurethane, sorbitol, trimethylolpropane, trimethylolethane, trimethylolpropane, and the like. The above-mentioned components may be used alone or in combination of two or more.

[0083] The content of the carbonizing agent may be 5 to 15 wt%, for example 5 to 10 wt%, based on the total weight of the refractory paint composition. If the content of the carbonizing agent is less than the above-mentioned range, a foam coating may not be sufficiently formed, and if it exceeds the above-mentioned range, an appropriate foam coating may not be formed, a foam flow phenomenon may occur, and the foaming effect and fire resistance performance may be deteriorated.

[0084]

[0085] pigment

[0086] The fire-resistant paint composition of the present invention may include a pigment. The pigment serves to impart color to the fire-resistant paint and at the same time form a ceramic insulating layer on the foamed paint film to improve fire-resistant performance. As the pigment, organic pigments, inorganic pigments, metallic pigments, aluminum paste (Al-paste), pearl, extender pigments, etc., which are commonly used in fire-resistant paints, can be used without limitation. Non-limiting examples of pigments that can be used include azo-based, phthalocyanine-based, iron oxide-based, cobalt-based, carbonate-based, sulfate-based, silicate-based, and chromate-based colored pigments, and for example, at least one selected from the group consisting of titanium dioxide (TiO2), zinc oxide, bismuth vanadate, cyanine green, carbon black, iron oxide red, iron oxide sulfur, navy blue, and cyanine blue can be used.

[0087] The content of the pigment may be 5 to 20 wt%, for example 8 to 15 wt%, based on the total weight of the fire-resistant paint composition. If the content of the pigment is less than the above-mentioned range, not only is the coloring and hiding of the coating poor, but also it is difficult to form a uniform porous layer inside the foamed coating during the high-temperature foaming process, which may lower the density and foaming rate of the foamed coating. On the other hand, if the content exceeds the above-mentioned range, the content of the flame retardant, etc. for forming the carbon layer is relatively reduced, which may lower the foaming rate and deteriorate the fire resistance performance.

[0088]

[0089] Supplement

[0090] The fire-resistant paint composition of the present invention may include a reinforcing agent. The reinforcing agent increases the strength of the carbonized layer when the dry, cured paint film is foamed at high temperatures to form a foamed paint film having a carbonized layer, thereby preventing the foamed paint film from peeling or partially flying away due to flames or the like, thereby improving fire resistance. In addition, the reinforcing agent imparts thixotropic properties to the paint, thereby preventing flow during painting, and can be evenly distributed within the dry paint film to prevent cracking.

[0091] The reinforcing agent may be any conventional component known in the relevant technical field without limitation, and may include, for example, inorganic materials such as metal oxides, metal hydroxides, metal compounds, glass, and silicon-based pigments. Non-limiting examples of usable reinforcing agents include silicates (talc), molybdenum trioxide, zirconium dioxide, aluminum hydroxide, zinc borate, glass powder, and glass fiber. The aforementioned components may be used alone or in combination of two or more.

[0092] The content of the reinforcing agent may be 2 to 15 wt%, for example 2 to 10 wt%, based on the total weight of the fire-resistant paint composition. If the content of the reinforcing agent is less than the above-mentioned range, the strength reinforcing effect of the foamed paint film may be insufficient, and if it exceeds the above-mentioned range, the strength of the carbonized layer may be too hard, causing cracks to occur when the carbonized layer is split when gas is generated, and also the foaming rate may be significantly reduced, resulting in poor fire-resistant performance.

[0093]

[0094] additives

[0095] The fire-resistant paint composition of the present invention may include additives commonly used in the field of fire-resistant paints, as long as they do not impair the inherent properties of the composition. Non-limiting examples of usable additives include flame retardants, film-forming agents, anti-foaming agents, dispersants, preservatives, plasticizers, antifreeze agents, pH regulators, and the like.

[0096] Flame retardants promote the formation of a carbon layer when the cured coating is exposed to high temperatures, thereby imparting flexibility to the initial foamed carbon layer. Conventional ingredients known in the art can be used as flame retardants without limitation, including phosphorus oxides, oxirane-treated triethyl phosphate polymers, and the like.

[0097] Film forming agents are used to facilitate the fusion between pigments and resins and film formation during film formation. They also lower the minimum film formation temperature (MFT), enabling film formation at low temperatures. Any commonly known ingredient in the relevant technical field can be used as the film forming agent without limitation, including, for example, 2-ethylhexyl benzoate, acetyl tributyl citrate, and diisobutyl adipate.

[0098] The above additives are added in an appropriate amount according to their function within a range known in the relevant technical field. For example, the content of each of the above additives may be 0.1 to 10 wt% based on the total weight of the fire-resistant paint composition.

[0099]

[0100] The fire-resistant paint composition according to the present invention can have a 2-hour fire resistance performance according to the fire resistance test method specified in Korean Industrial Standard KS F2257. Specifically, when the dry coating film is heated for 2 hours, the average temperature of each cross section can be maintained at 538°C or lower, and the overall maximum temperature can be continuously maintained at 649°C or lower. In addition, the fire-resistant paint composition satisfies the physical properties of KU viscosity (25°C) of 110 to 140 KU, flow resistance (SAG) of 60 mil or higher, and has excellent painting workability.

[0101] The fire-resistant coating composition of the present invention can be applied to a variety of applications requiring superior fire resistance. For example, it can be used in general, factory, and commercial buildings, as well as in ships and marine structures, automobiles, aircraft, and mobile homes. Furthermore, it can be applied to the surfaces of mineral wool boards, cables, trays, concrete, steel, wood, and other materials to impart fire resistance.

[0102] The thickness of the dried film is not particularly limited and can be appropriately adjusted within a range known in the art. For example, the film can be applied to a thickness of 0.5 to 3.0 mm. Conventional methods known in the art can be applied, including brush painting, air spray painting, airless spray painting, and roller painting.

[0103] The fire-resistant coating composition of the present invention can be applied as a base coat, intermediate coat, or top coat. For example, the fire-resistant coating composition of the present invention can be used as a middle coat coating composition in a coating system comprising a base coat, an intermediate coat, and a top coat.

[0104] As the above-mentioned undercoat coating composition, a water-soluble anti-corrosion coating composition can be used, and for example, a coating composition containing 15 to 50 wt% of at least one fatty acid-modified epoxy resin having an epoxy equivalent of 200 to 1,000 g / eq, 1 to 20 wt% of an amide-based curing agent, 10 to 40 wt% of an extender pigment, and the remainder of a solvent can be used, based on the total weight of the undercoat coating composition. In the above-mentioned undercoat coating composition, the fatty acid-modified epoxy resin and the amide-based curing agent can be included in a weight ratio of 10:6 to 10:8.

[0105] As the above-mentioned coating composition for use as a topcoat, a water-soluble coating composition can be used, and for example, a coating composition containing 40 to 60 wt% of a core-shell type organic-inorganic composite copolymer emulsion resin, 5 to 20 wt% of a filler pigment, 1 to 20 wt% of a colored pigment, and 5 to 40 wt% of water can be used, based on the total weight of the coating composition for use as a topcoat.

[0106]

[0107] The present invention will be described in more detail through the following examples. However, the following examples are intended only to aid understanding of the present invention and are not intended to limit the scope of the present invention in any way.

[0108]

[0109] [Manufacturing Example 1-3: Manufacturing of Vinyl Acetate Copolymer]

[0110] According to the composition in Table 1 below, raw materials 1-6 were placed in a 4-L round-bottomed flask, and the temperature was raised to 60°C while introducing nitrogen. When the temperature was raised, 25 wt% of the initiator mixture (raw materials 7-8) and 10 wt% of the monomer mixture (raw materials 9-13) were added dropwise and reacted while raising the temperature to 80°C. Thereafter, the remaining initiator mixture and monomer mixture were added dropwise evenly at 80°C for 4 hours. After the dropping was completed, the mixture was maintained at 80°C for 1 hour, raw material 14 was added, cooled to 40°C, and filtered through a 100 mesh filter to produce a vinyl acetate copolymer (solid content 50.0%, particle size (D50) 350 nm, pH 4.0, viscosity (25°C) 400 cPs) of each manufacturing example.

[0111]

[0112] [Comparative Manufacturing Example 1-5: Manufacturing of Vinyl Acetate Copolymer]

[0113] Except for the compositions in Table 2 below, vinyl acetate copolymers of each comparative manufacturing example were manufactured in the same manner as the manufacturing example.

[0114]

[0115]

[0116]

[0117] Protective colloid: NAatrasol250LR (Ashland)

[0118] Emulsifier 1: DO-113 (Dongnam Chemical)

[0119] Emulsifier 2: FL-20 (Hanong Chemical)

[0120] Emulsifier 3: FL-10 (Hanong Chemical)

[0121] Initiator: KPS (Adeka)

[0122] Alkyl modified vinyl acetate monomer: Compound of the above chemical formula 1 (R 1 =CH3, R 2 =C6CH 13 )

[0123] Monomer having a polyvalent double bond: Compound of the above chemical formula 3 (R=CH2)

[0124] Phosphoric acid-containing acrylic monomer: a compound of the above chemical formula 2 (R = propylene oxide, n = 5)

[0125] Acrylic monomer: BA (Butyl acrylate)

[0126]

[0127] [Example 1-7: Preparation of fire-resistant paint composition]

[0128] According to the composition in Table 3 below, a fire-resistant paint composition for each example was prepared.

[0129]

[0130] [Comparative Example 1-5: Preparation of a Fire-Resistant Paint Composition]

[0131] According to the composition in Table 4 below, a fire-resistant paint composition for each comparative example was prepared.

[0132]

[0133]

[0134]

[0135] Copolymer 1: Vinyl acetate copolymer of Preparation Example 1

[0136] Copolymer 2: Vinyl acetate copolymer of Preparation Example 2

[0137] Copolymer 3: Vinyl acetate copolymer of Preparation Example 3

[0138] Copolymer 4: Vinyl acetate copolymer of Comparative Manufacturing Example 1

[0139] Copolymer 5: Vinyl acetate copolymer of Comparative Manufacturing Example 2

[0140] Copolymer 6: Vinyl acetate copolymer of Comparative Manufacturing Example 3

[0141] Copolymer 7: Vinyl acetate copolymer of Comparative Manufacturing Example 4

[0142] Copolymer 8: Vinyl acetate copolymer of Comparative Manufacturing Example 5

[0143] Pigment: Titanium Dioxide (13463-67-7, Ningbo Xinfu Titanium Dioxide)

[0144] Carbonizing agent: PENTA (115-77-5, Hangzhou JLS flame retardants)

[0145] Foaming agent: melamine (108-78-1, Hangzhou JLS flame retardants)

[0146] Catalyst: Ammonium polyphosphate (68333-79-9, Zhenjiang Great Honest)

[0147] Supplement: Lapinus CF 50 (Lapinus)

[0148] Flame retardant: Liquid flame retardant (FlamEL RFL 184538-58-7, KhaiEL GmbH)

[0149] Film former: Velate 368 Coalescent (EASTMAN)

[0150] Additives: A mixture of dispersant (Disperse 752W, EVONIC Industries), preservative (Acticide MBS, Thor specialties), antifreeze (Propylene Glycol, DOW chemical), antifoam 1 (FOAMEX 3062, EVONIC Industries) and antifoam 2 (Foamstar ST2400, BASF) (30% dispersant, 20% preservative, 30% antifreeze, 20% antifoam)

[0151] Thickener: Polyamide wax (Monoral HR-300, HS CHEM)

[0152]

[0153] [Physical property evaluation]

[0154] The properties of the refractory paint compositions manufactured according to each example and comparative example and the coating films formed thereby were measured according to the following methods, and the results are shown in Tables 5 and 6 below.

[0155]

[0156] Sample manufacturing

[0157] The paint compositions manufactured in each example and comparative example were air-sprayed onto a 1.5T cold-rolled steel plate with a dry film thickness of 1 mm, and then dried under conditions of a temperature of 25±2°C and a relative humidity of 50±10%.

[0158]

[0159] Water resistance

[0160] After each specimen was immersed in clean water for 24 hours, the appearance of the coating was visually evaluated according to the drying time.

[0161]

[0162] Fire resistance performance

[0163] Fire resistance performance tests were conducted based on KS F2257.

[0164]

[0165] Flow resistance

[0166] An ANTI SAGMETER was placed on a glass plate, and the paint compositions of each example and comparative example (adjusted to 25±2 ℃) were evenly drawn down at a constant speed (150 mm / s), and then immediately placed vertically on a support with the thinnest part of the film facing upwards to dry (inside the test room temperature 25±2 ℃, relative humidity 65±10%). The thickest stripe that was about to be attached to the stripe below was selected, and the central part was evaluated.

[0167]

[0168] Viscosity (KU)

[0169] It was measured using a STORMER viscometer at 25 ℃.

[0170]

[0171]

[0172]

[0173]

[0174] From the results in Tables 5 and 6 above, the coating film formed with the fire-resistant coating composition of Example 1-7 containing the vinyl acetate copolymer (Preparation Example 1-3) according to the present invention exhibited excellent physical properties across all measured items. Specifically, the coating film formed with the fire-resistant coating composition of Example 1-7 according to the present invention satisfied the 2-hour fire resistance performance, while also exhibiting excellent water resistance and workability.

[0175] On the other hand, the coating films formed with the fire-resistant paint compositions of Comparative Examples 1 to 5, which include a vinyl acetate copolymer not including a phosphoric acid-containing acrylic monomer (Comparative Manufacturing Example 1), a vinyl acetate copolymer not including a polyvalent double bond-containing monomer (Comparative Manufacturing Example 2), a vinyl acetate copolymer not including an alkyl-modified vinyl acetate monomer (Comparative Manufacturing Example 3), and a vinyl acetate copolymer including a phosphoric acid-containing acrylic monomer but in an amount outside the content range of the present invention (Comparative Manufacturing Examples 4 and 5), showed inferior water resistance compared to the fire-resistant paint compositions of the examples.

[0176]

[0177] The present invention provides an environmentally friendly water-based fire-resistant paint composition having excellent fire resistance and excellent water resistance of the coating film. The fire-resistant paint composition according to the present invention exhibits fire resistance of 2 hours or more, while also exhibiting excellent durability and water resistance. The fire-resistant paint composition of the present invention has excellent initial water resistance as well as complete drying of the coating film, and has the advantage of enabling off-site (shop) coating due to its fast drying speed, shortening the coating period even in on-site coating, and facilitating film thickness management. In addition, the water-based fire-resistant paint composition according to the present invention is environmentally friendly because it does not contain organic solvents.

Claims

1. Polymerized from a monomer mixture comprising a vinyl acetate monomer, an alkyl-modified vinyl acetate monomer, a phosphoric acid-containing acrylic monomer and a polyvalent double bond-containing monomer, A vinyl acetate copolymer comprising 0.5 to 5 wt% of the above phosphoric acid-containing acrylic monomer based on the total weight of the monomer mixture.

2. In the first paragraph, a vinyl acetate copolymer wherein the alkyl modified vinyl acetate monomer is a compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, R 1 , R 2 are hydrocarbon groups having 1 to 15 carbon atoms, which are the same or different.

3. In the first paragraph, a vinyl acetate copolymer in which the phosphoric acid-containing acrylic monomer is a compound represented by the following chemical formula 2: [Chemical formula 2] In the above chemical formula 2, R is ethylene oxide or propylene oxide, n is an integer from 0 to 10.

4. In the first paragraph, the vinyl acetate copolymer wherein the polyvalent double bond-containing monomer is a compound represented by the following chemical formula 3: [Chemical Formula 3] In the above chemical formula 3, R is a hydrocarbon group having 1 to 15 carbon atoms.

5. A vinyl acetate copolymer comprising, in the first paragraph, 50 to 85 wt% of the vinyl acetate monomer, 10 to 40 wt% of the alkyl-modified vinyl acetate monomer, 0.5 to 5 wt% of the phosphoric acid-containing acrylic monomer, and 0.01 to 0.5 wt% of the polyvalent double bond-containing monomer based on the total weight of the monomer mixture.

6. A vinyl acetate copolymer further comprising 4 to 20 wt% of an acrylic monomer based on the total weight of the monomer mixture in the first paragraph.

7. A vinyl acetate copolymer according to claim 1, having a glass transition temperature of -30 to 60°C, a film formation temperature of 0 to 30°C, a solid content of 40 to 60%, a particle size (D50) of 200 to 500 nm, a viscosity (25°C) of 200 to 800 cPs, and a pH of 2.5 to 5.

5.

8. A fire-resistant paint composition comprising a vinyl acetate copolymer, a foaming agent and an aqueous solvent according to any one of claims 1 to 7.

9. A fire-resistant paint composition according to claim 8, further comprising at least one selected from the group consisting of a thickener, a catalyst, a carbonizing agent, a pigment, a reinforcing agent, and a flame retardant.

10. In claim 9, a fire-resistant paint composition comprising 5 to 35 wt% of the vinyl acetate copolymer, 1 to 15 wt% of the blowing agent, 1 to 10 wt% of the thickener, 15 to 35 wt% of the catalyst, 5 to 15 wt% of the carbonizing agent, 5 to 20 wt% of the pigment, 2 to 15 wt% of the reinforcing agent, 0.1 to 10 wt% of the flame retardant, and a balance of the aqueous solvent satisfying 100 wt% of the fire-resistant paint composition, based on the total weight of the fire-resistant paint composition.

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