KR20220058022A - The infrared low emissivity paint material compositions containing organic solvent based conducting polymer and silver nano wire complex and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an infrared low emissivity paint composition having low infrared emissivity in a dark gray color by mixing and dispersing an organic solvent type conductive polymer and a silver nanowire complex in an infrared low emissivity paint; and a method for preparing the same.

Description

Infrared low-emissivity paint composition comprising organic solvent-type conductive polymer and silver nanowire composite, and manufacturing method thereof

The present invention relates to a paint composition for infrared stealth, and more particularly, to an infrared low emissivity paint composition comprising an organic solvent-type conductive polymer and a silver nanowire composite in an infrared low emissivity paint, and to a method for manufacturing the same.

Infrared low-emissivity paint used in infrared stealth technology reflects, absorbs, or radiates radiation energy from solar heat in the mid-infrared range with a wavelength of 3 μm to 5 μm and far-infrared light with a wavelength of 8 μm to 12 μm. It is a paint that reduces the expression of generated thermal energy to the outside of the object.

In general, infrared low-emissivity paints have a low-infrared radiation effect because metals such as aluminum flakes are present in the paints. However, aluminum flakes have a disadvantage in that they are rather vulnerable to visual monitoring (visible light band) due to their shiny properties. To compensate for this disadvantage, carbon black, a representative black color pigment, is added to the paint to darken the brightness of the paint, but these black pigments have high infrared emissivity due to their high infrared absorption. It interferes with the infrared low emission effect, making it vulnerable to detection by infrared signal detection means such as infrared radar.

Therefore, there is a demand for the development of a low-infrared emissivity paint with improved low-infrared radiation effect.

Japanese Patent No. 6418159

Accordingly, in consideration of the above points, the present invention provides a low-infrared low-emissivity coating composition capable of increasing the low-infrared radiation effect even though it is a dark-colored coating by introducing a composite of an organic solvent-type conductive polymer and silver nanowires into an infrared low-emissivity coating composition and its It aims to provide about a manufacturing method.

In order to achieve the above object, the infrared low-emissivity coating composition of the present invention contains 20.0 to 50.0% by weight of a resin, 3.0 to 5.0% by weight of an infrared reflective pigment, and 0.1 to 3.0% by weight of a black pigment based on 100% by weight of the total composition. , 1.0 to 5.0% by weight of inorganic pigment, 1.0 to 20.0% by weight of additives, 0.1 to 1.0% by weight of organic solvent-type conductive polymer, 0.2 to 2.0% by weight of silver nanowires, 20.0 to 40.0% by weight of aluminum flakes (Al Flake) and the remaining amount of the organic solvent.

The organic solvent-type conductive polymer is a conductive polymer solution containing a conductive polymer which is one or more polymers selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polypyrrole and polyaniline or a copolymer thereof. was substituted with an organic solvent through a solvent substitution method.

The resin may be any one selected from the group consisting of a polyurethane-based resin, an acrylic resin, a polysiloxane-based resin, a polyester-based resin, and mixtures thereof.

The aluminum flakes may have an average particle size of 5 μm to 40 μm.

The infrared reflective pigment may have a total reflectance of 40% or more in a region having a wavelength of 920 nm to 2500 nm.

The additive may include any one or more of a wetting and dispersing agent and a UV stabilizer.

The organic solvent may be included in an amount of 30.0 to 45.0 wt% based on 100 wt% of the infrared low-emissivity coating composition.

The infrared low-emissivity coating composition is characterized in that the emissivity value is 0.6 or less in the infrared thermal image band, that is, in the mid-infrared band with a wavelength of 3 μm to 5 μm and the far-infrared band with a wavelength of 8 μm to 12 μm.

In order to achieve another object, the manufacturing method of the low-infrared emissivity coating composition of the present invention comprises (a) a resin, an infrared reflective pigment, a black pigment, an inorganic pigment, an additive, an organic solvent-type conductive polymer, silver nanowires and aluminum flakes. preparing, (b) forming a dispersion by putting the resin, the infrared reflective pigment, the black pigment, the inorganic pigment, the additive, the organic solvent-type conductive polymer and the silver nanowire in an organic solvent and dispersing; (c) putting the aluminum flakes in an organic solvent and mixing them to form an aluminum flake solution, and (d) mixing the dispersion and the aluminum flakes solution to obtain an infrared low-emissivity coating composition. .

The dispersion prepared in step (b) contains 20.0 to 50.0% by weight of the resin, 3.0 to 5.0% by weight of the infrared reflective pigment, and 0.1 to 3.0% by weight based on 100% by weight of the total low-ultraviolet low-emissivity coating composition A black pigment, 1.0 to 5.0% by weight of the inorganic pigment, 1.0 to 20.0% by weight of the additive, 0.1 to 1.0% by weight of the organic solvent-type conductive polymer, 0.2 to 2.0% by weight of the silver nanowire, and 0.2 to 2.0% by weight of the organic solvent 2.0 to 15.0 wt% may be included.

The aluminum flake solution prepared in step (c) may contain 20.0 to 40.0% by weight of the aluminum flake, and 15.0 to 43.0% by weight of the organic solvent, based on 100% by weight of the total low-UV, low-emissivity coating composition there is.

The low-infrared low-emissivity coating composition of the present invention reduces the use of carbon black, which was used as a black-based color pigment to reduce the low-infrared emission effect, and uses a solvent-substituted organic solvent-type conductive polymer to the painted surface It allowed me to have this dark color.

In addition, 1 wt% of silver nanowires dispersed in the actual infrared stealth paint using silver nanowires as micro conductors connecting the organic solvent-type conductive polymer chain domain and the other adjacent organic solvent-type conductive polymer chain domain to each other A very small amount of organic solvent-type conductive polymer particles are electrically connected to each other, so that the small amount of infrared radiation absorbed by the conductive polymer particles is not re-emitted, thereby maximizing the effect of low infrared radiation.

In addition, if the infrared low-emissivity paint composition of the present invention is used for not only inorganic skin coatings but also building exterior paints, it is possible to significantly increase the efficiency of cooling and heating by reducing the absorption of infrared rays, so energy saving can be expected.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

1 is a schematic diagram showing a state in which an infrared low-emissivity paint composition to which a conductive polymer and a silver nanowire composite is not applied according to Comparative Example 1 of the present invention is coated on a base material.
FIG. 2 is a schematic diagram showing a state in which an infrared low-emissivity paint composition to which a conductive polymer and silver nanowire composite is applied according to Example 1 of the present invention is coated on a base material.
3 is a graph showing infrared spectral emissivity measurement results in a coating film formed of the infrared low emissivity coating composition according to Example 1 and Comparative Example 1 of the present invention.

Hereinafter, the present invention will be described in detail. However, this is not intended to limit the present invention to a specific disclosed form as an example, but it should be understood to include all modifications, equivalents and substitutions included in the spirit and scope of the present invention.

The infrared low-emissivity coating composition of the present invention comprises a resin, an infrared reflective pigment, a black pigment, an inorganic pigment, an additive, an organic solvent-type conductive polymer, silver nanowires, aluminum flakes, and an organic solvent.

The resin may be any one selected from the group consisting of a polyurethane-based resin, an acrylic resin, a polysiloxane-based resin, a polyester-based resin, and mixtures thereof, and among them, a polyurethane-based resin may be preferably used.

The content of the resin may include 20.0 to 50.0% by weight based on 100% by weight of the total of the infrared low-emissivity coating composition. If the content of the resin is less than 20.0 wt%, a problem of lowering adhesion of the coating composition may occur due to the low content, and conversely, if the resin content exceeds 50.0 wt%, aluminum flakes, etc. As the content of is reduced, there may be a problem that the effect of lowering the infrared emissivity is lowered.

The infrared reflective pigment may be used as a color pigment for realizing black while simultaneously reducing the infrared signal of the coating composition and having a total reflectance of 40% or more in a wavelength range of 920 nm to 2500 nm. The infrared reflective pigment can preferably be used as long as it is a commonly used black infrared reflective pigment capable of expressing black color, and is commercially produced as an inorganic pigment of Fe-Cr, Cu-Bi and Ni-Fe types. can be used

Representative products of the infrared reflective pigment include BASF's Sicopal Black K0095, Paliogen Black L0086, Xfast 20-5 BK0084, Xfast BK0095, FERRO's 10201 Eclipse Black, 10202 Eclipse Black, SPP-3025 Black and IR Black V-799, Tokan Material Technology's 42-708A, 42-713A and 42-714A can be used, and among them, Fe-Cr type inorganic infrared signal reduction pigment (Cool Pigment) such as Sicopal Black K0095 from BASF can be used preferably. , but is not necessarily limited thereto.

The content of the infrared reflective pigment is set to be in the range of 3.0 to 5.0% by weight based on 100% by weight of the total weight of the infrared low-emissivity paint composition. If the amount of the infrared reflective pigment used is less than 3.0 wt% based on the total amount of the coating composition, it is difficult for the lightness index (L*) of the coating composition to be 50 or less, and if it exceeds 5.0 wt%, the amount of the coating composition It is undesirable because the infrared emissivity value exceeds 0.6.

In the present specification, the lightness index of the infrared low emissivity coating composition is preferably 50 or less, measured at a measurement angle of 45 degrees with respect to transmitted light under the D65 light source according to the conditions of KS M 5000: 2014.

In addition, emissivity refers to the ratio at which an object absorbs, transmits, and reflects energy having an arbitrary specific wavelength. That is, in the present specification, the emissivity refers to the degree of absorption of infrared energy in the infrared wavelength region, and specifically, the wavelengths of mid-infrared rays with a wavelength of 3 μm to 5 μm and infrared rays in the far-infrared region with a wavelength of 8 μm to 12 μm are used. When applied, it means the ratio of absorbed infrared energy to the applied infrared energy.

The black pigment is a black-based color pigment used for hiding power of a coating film, and preferably, carbon black may be used.

The content of the black pigment is set to be in the range of 0.1 to 3.0% by weight based on 100% by weight of the total weight of the infrared low-emissivity paint composition. If the amount of the black pigment used is less than 0.1% by weight based on the total amount of the coating composition, there may be a problem in that the hiding power of the coating film is lowered due to a small amount of the black pigment, and if it exceeds 3.0% by weight, the infrared emissivity of the coating composition It is undesirable because the value becomes 0.6 or more.

The inorganic pigment is used to improve the hiding power and mechanical properties of the coating film, preferably inorganic phthalocyanine blue (Phthalocyanine Blue), and commercially produced products can be used.

Here, as representative products of the inorganic phthalocyanine blue, Dianichi seika color's Chromofine Blue 4920, BASF's Heliogen Blue L7087, Lynx Technology Inc.'s Blue M3L4, Sanyo's Cyanyne Blue g314, Ciba_Geigy's IRgalite Blue BCA, etc. can be used. It is not limited.

The amount of the inorganic pigment to be used is in the range of 1.0 to 5.0% by weight, based on 100% by weight of the total weight of the infrared low-emissivity coating composition. If the amount of the inorganic pigment used is less than 1.0% by weight based on the total amount of the coating composition, it is difficult to realize the desired physical properties, and if it exceeds 5.0% by weight, it is not preferable because the infrared emissivity value of the coating composition is 0.6 or more.

The additive included in the infrared low-emissivity coating composition uses a wetting dispersant, a UV stabilizer, etc., and such additives may be used in an amount of 1.0 to 20.0% by weight based on 100% by weight of the infrared low-emissivity coating composition. .

The wetting and dispersing agent uses a deagglomeration type wetting and dispersing agent to prevent sedimentation of inorganic fillers and pigments with high specific gravity among components of the paint and to prevent color separation.

Commercially produced products may be used as the wetting and dispersing agent. Representative products include YK's Disperbyk 180, Disperbyk 161, Disperbyk 2055, TEGO's Dispers 610, Dispers 628, Dispers 670, Dispers 671, AFCONA's AFCONA 5010, AFCONA 5054, AFCONA 5065, etc., but are not limited thereto.

The amount of the wetting and dispersant to be used is in the range of 0.5 to 2.0 wt%, based on 100 wt% of the total weight of the infrared low emissivity paint composition. If the amount of the wetting and dispersant used is less than 0.5 wt %, it is insufficient to obtain the suggested effect, and if it exceeds 2.0 wt %, it may be a factor impairing the physical properties of the coating film.

The ultraviolet stabilizer can improve the weather resistance of the coating film by selectively absorbing ultraviolet rays among sunlight and converting them into thermal energy or by dissipating free radicals generated by decomposition from ultraviolet rays.

The UV stabilizer is generally a UV absorber represented by benzophenone and hydroxyphenyl-benzothiazole or hydroxyphenyl-Triazine and a hindered amine (HALS). A UV stabilizer commonly referred to as a light stabilizer is mainly used.

Commercially produced products can be used as the UV stabilizer, and alternative products include BASF's TINUVIN 1130, TINUVIN 928 and TINUVIN 400, Songwon Industries' SONGSORB ^® 1000, SONGSORB ^® 7120 and SONSORB ^® 15, and the like, and the HALS Representative products of BASF include, but are not limited to, TINUVIN 292, TINUVIN 123 and TINUVIN 144 from BASF, SABO ^® STAB UV 40, SABO ^® STAB UV65 and SABO ^® STAB UV 94 from Songwon Industries.

The amount of the ultraviolet stabilizer to be used is in the range of 1.0 to 7.0% by weight, based on 100% by weight of the total weight of the infrared low-emissivity paint composition. If the amount of the UV stabilizer used is less than 1.0% by weight, it is insufficient to obtain the suggested effect, and when it exceeds 7.0% by weight, it may be a factor impairing the physical properties of the coating film.

The aluminum flakes included in the low-infrared emissivity paint composition are used for the problem of increasing the infrared emissivity due to the resin and black pigments and inorganic pigments having high infrared absorptivity, and those having an average particle size in the range of 5 to 40 μm may be used.

When the average particle size of the aluminum flakes satisfies 5 to 40 μm, the metallic feel in the coating composition can be minimized, and therefore, it is preferable to satisfy the average particle size range. If the average particle size of the aluminum flakes exceeds 40 μm, a problem of shimmering metal may occur due to the large particle size.

As the aluminum flakes, commercially produced products may be used. Representative products include, for example, AsahiKasei's PV-M5090, FV-T5060, CP-R250H and CP-R530H, ECKART's STAPA HCP 6100, HCP 6140, HCP 6260, STAPA 1515 n.l and STAPA 4 n.l, etc. can be used. However, the present invention is not limited thereto.

The content of the aluminum flakes in the low-infrared low-emissivity coating composition is set to be in the range of 20.0 to 40.0% by weight, based on a total of 100% by weight of the low-infrared low-emissivity coating composition. If the content of the aluminum flake is less than 20.0% by weight based on the total amount of the coating composition, the reflective property effect of the coating composition is weak, and if it exceeds 40.0% by weight, the adhesion and physical properties of the coating composition are reduced. because it can be

The organic solvent-type conductive polymer included in the low-infrared emissivity paint composition is used to solve the problem of increasing the infrared emissivity due to the infrared reflective pigment, and the conductive polymer solution is substituted with an organic solvent through a solvent substitution method.

A commonly used conductive polymer is poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (PEDOT:PSS), a monomer 3,4-ethylenedioxythiophene, and a stabilizer polystyrenesulfonic acid ( Polystyrene Sulfonate) and a polymerization oxidizing agent are reacted in an aqueous solvent to produce a water-based conductive polymer. However, the aqueous conductive polymer cannot be stably dispersed in an organic solvent and condensed, which causes problems in dispersibility and conductivity.

Therefore, in order to improve dispersibility with an organic solvent and increase conductivity, an organic solvent-type conductive polymer in which an aqueous conductive polymer solution is sequentially solvent-substituted with an alcohol solvent and an organic solvent through a solvent substitution method is used.

The solvent substitution method for preparing the organic solvent-type conductive polymer includes the steps of preparing a first conductive polymer mixture by mixing a conductive polymer solution in which a stabilizer and a conductive polymer are dispersed together in an aqueous solvent and an alcohol-based solvent, specifically, A first solvent substitution step of first replacing the first conductive polymer mixture with an alcohol-based solvent by passing the first conductive polymer mixture and an alcohol-based solvent through a filtration membrane, and a second conductive polymer by mixing the conductive polymer solution that has undergone the first solvent substitution step and an organic solvent It is made by performing a process including the step of preparing a mixed solution, and a secondary solvent substitution step in which the second conductive polymer mixed solution and the organic solvent are passed together through a filtration membrane to secondarily replace the organic solvent with the organic solvent.

The step of preparing the first conductive polymer mixture is a preparation process performed to prevent phase separation from the alcohol solvent added in the first solvent substitution step, and the dispersant and the conductive polymer are stably dispersed in the aqueous solvent phase (Phase). A first conductive polymer mixture is prepared by mixing the conductive polymer solution and an alcohol-based solvent in a volume ratio of about 1:1.

Then, the first solvent substitution step is a step of completely replacing the first solution with the first solution by passing the prepared first conductive polymer mixed solution through a filtration membrane while removing the aqueous solvent of the first conductive polymer mixed solution and slowly adding an alcohol-based solvent, By removing impurities such as a dispersant contained in the conductive polymer solution together with an aqueous solvent through the filtration membrane, a purification process in which the conductive polymer solution is purified at the same time and a solvent substitution process of the conductive polymer solution with an alcohol-based solvent are performed.

As the filtration membrane, a filtration membrane having pores of 0.001 to 1 μm or a filtration membrane having a molecular weight cutoff of 1000 to 1,000,000 g/mol may be used.

Examples of the alcohol-based solvent used in the first solvent substitution step include an alcohol-based solvent such as methanol, ethanol, iso-Propanol, and butanol, ethylene glycol (Ethylene Glycol). ), 1,4-butanediol (1,4-Butanediol) and glycol-based solvents such as diethylene glycol (Diethylene Glycol), any one selected from the group consisting of polyol-based solvents, or a mixed organic solvent in which two or more are mixed can be used

The first solvent substitution step is performed at 5 to 150° C., and the pressure during the operation is characterized in that a pressure of 0.0001 to 10 bar is applied.

Then, the solvent substitution method of substituting the organic solvent for the conductive polymer solution in the alcoholic solvent prepared through the first solvent substitution step is the same as the first solvent substitution step 2 except that the solvent used is an organic solvent. A step of preparing a primary conductive polymer mixture solution and a secondary solvent substitution step are performed.

After confirming that the solvent substitution rate is 99% or more by measuring the density of the conductive polymer solution prepared through the primary solvent substitution, the secondary solvent substitution step is performed.

The step of preparing the second conductive polymer mixture is a preparation process performed so that phase separation from the organic solvent added in the second solvent substitution step does not occur, and the conductive polymer dispersed in the alcohol solvent through the first solvent substitution step A second conductive polymer mixture is prepared by mixing the polymer solution and the organic solvent solvent in a volume ratio of about 1:1.

In the second solvent substitution step, the alcohol-based solvent is removed while passing the second conductive polymer mixture through the filtration membrane, and the organic solvent is slowly added to completely replace the organic solvent. The organic solvent-type conductive polymer is formed by performing a purification process in which the conductive polymer solution is simultaneously purified by being removed together with the solvent and a solvent substitution process of the conductive polymer solution by an organic solvent.

The filtration membrane used in the second solvent substitution step uses the same type of filtration membrane used in the first solvent substitution step, and may be performed at the same process temperature and process pressure as the first solvent substitution step.

As the organic solvent, any one selected from the group consisting of an ether-based solvent, a ketone-based solvent, a sulfoxide-based solvent, and an amide-based solvent, or a mixed organic solvent obtained by mixing two or more may be used.

In the solvent substitution method, as the conductive polymer, any one or more polymers selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polypyrrole and polyaniline or copolymers thereof may be used. Preferably, poly(3,4-ethylenedioxythiophene):polystyrenesulfonic acid (PEDOT:PSS) can be used.

As the organic solvent-type conductive polymer, it is preferable to use a conductive polymer having an average particle size of 0.01 to 5 μm dispersed in an organic solvent to maximize the effect of low infrared radiation.

The content of the organic solvent-type conductive polymer is set to be 0.1 to 1.0% by weight based on 100% by weight of the total weight of the infrared low-emissivity paint composition. If the organic solvent-type conductive polymer is less than 0.1 wt%, there is no effect on improving the low-infrared radiation effect in a very small amount, and if it exceeds 1.0 wt%, the brightness index (L*) of the infrared coating composition is difficult to be implemented below 50.

The silver nanowire is added to improve the low-infrared radiation effect together with the organic solvent-type conductive polymer with excellent conductivity, and refers to a wire structure having a size of nanometers. The diameter of the silver nanowire may have a diameter of several hundred nm from a diameter of less than 10 nm, and the aspect ratio is greater than 10.

The silver nanowire connects the organic solvent-type conductive polymer particles dispersed in the infrared low-emissivity paint composition to connect the small amount of infrared rays absorbed by the conductive polymer particles.

The content of the silver nanowire may be added in an amount of 0.2 to 2.0% by weight based on 100% by weight of the total weight of the infrared low-emissivity coating composition. If the silver nanowire is less than 0.2% by weight, it is difficult to connect with the conductive polymer particles on the infrared low emissivity paint composition due to a small amount, so that it does not sufficiently perform the role of a micro conductor, and there is no effect in improving the infrared low emission effect. When the amount of wire exceeds 2.0% by weight, dispersion stability is lowered due to excessive addition amount, leading to aggregation on the polymer resin, forming an aggregate on the surface of the low-infrared emissivity paint, increasing the brilliance of bright silver. It is difficult to implement the brightness index (L*) below 50 and may be a factor impairing the coating property of the low-infrared low-emissivity paint surface.

The silver nanowire uses an alcohol-based solvent-type conductive polymer in which the solvent is substituted with an alcohol-based solvent through a solvent substitution method to form a complex with the organic solvent-type conductive polymer and to improve dispersibility in the paint composition.

The solvent substitution method of the silver nanowires is specifically, a silver nanowire solution stably dispersed with a water-based solvent phase or a stabilizer in which an aqueous solvent and a small amount of an alcohol-based solvent are mixed, and an alcohol-based solvent is mixed to form a mixture. Preparing, and passing the prepared mixed solution and an alcohol-based solvent together through a filtration membrane to purify the silver nanowires and at the same time include a purification and solvent substitution step of solvent-substituting the alcohol-based solvent.

In the purification and solvent substitution step, the aqueous solvent and stabilizer of the silver nanowire solution contained in the mixed solution are removed while the mixed solution passes through the filtration membrane, and the solvent is completely replaced with an alcohol-based solvent that is filtered together.

Here, as the filtration membrane, a filtration membrane having pores of 0.001 to 1 μm or a filtration membrane having a molecular weight cutoff of 1000 to 1,000,000 g/mol may be used.

The alcohol-based solvent is any one selected from the group consisting of alcohol-based solvents such as methanol, ethanol, iso-propanol, butanol, or a mixed organic solvent in which two or more are mixed. can

The purification and solvent substitution step of the silver nanowire solution is characterized in that it is performed at 5 to 150 ℃, and the pressure during the operation is characterized in that a pressure of 0.0001 to 10 bar is applied.

As shown in the solvent substitution process, the silver nanowire solution substituted with the alcohol solvent can be mixed with the organic solvent type conductive polymer solution solvent substituted with the organic solvent due to similar solubility characteristics (partially soluble) with the organic solvent. It is possible to prepare a blend-dispersion of an organic solvent-type conductive polymer and silver nanowire composite in which nanowires and conductive polymers maintain dispersion stability.

The organic solvent included in the low-infrared emissivity coating composition is used to impart suitable boiling point and rheology characteristics to the coating composition, and the organic solvent includes Xylene, Butyl Acetate, and Ethyl. Ethyl Acetate, Isobutylmethyl Ketone, Solvent Naphtha, 1-Methoxyl-2-acetoxypropane, Propylene Glycol Methyl Ether Propionate ( Propylene Glycol Methyl Ether Propionate), toluene, etc. may be used, and the above materials may be used alone or in combination of two or more.

The amount of the organic solvent used is the resin, the infrared reflective pigment, the black pigment, the inorganic pigment, the additive, the organic solvent type conductive polymer, the silver nanowire, and the aluminum flake in the total amount of the infrared low emissivity coating composition. However, it is preferably included in the range of 30.0 to 45.0 wt% based on 100 wt% of the infrared low-emissivity coating composition for uniform mixing and dispersion of the coating composition material.

The coating composition prepared including the above components does not require a separate heat treatment after painting using the same, but requires a drying time of at least 7 days at room temperature to realize the physical properties of the coating film.

Hereinafter, the present invention will be described in more detail through specific examples and comparative examples.

[Example 1]

Polyurethane resin 47.0% by weight, infrared reflective pigment (Sicopal Black K0095, BASF) 4.4% by weight, black pigment (Special schrarz #4, Degussa_huls) 2.4% by weight, inorganic pigment (Blue M3L4, Lynx Technology Inc) .g) 16.5 wt% of an additive containing 1.8 wt%, 0.7 wt% of a wetting and dispersing agent (Disperbyk-161, BYK), an organic solvent-type conductive polymer as an organic solvent-type poly(3,4-ethylenedioxythiophene): Polystyrene sulfonic acid (PEDOT:PSS) (Clevios PH 1000, Heraeus) 0.3% by weight, silver nanowires (AgNW Gen7, C3nano) 0.6% by weight, and butyl acetate 5.0% by weight as an organic solvent and dispersed to form a dispersion. At the end of dispersion, the NS (National Standard) particle size is 6 or more. While dispersion is in progress, put 27.0 wt% of aluminum flakes (CP-R530H, AsahiKasei) and 40 wt% of butyl acetate as an organic solvent in a separate paint preparation container, and when the aluminum flakes are sufficiently wet in the organic solvent Stir to form an aluminum flake solution. After the aluminum flake solution is stirred, the dispersion is added and stirred for at least 10 minutes. Then, 3.2% by weight of HALS (TINUVIN 292, BASF) and 3.2% by weight of a UV absorber (TINUVIN 1130, BASF) were added and stirred for at least 10 minutes to prepare a coating composition.

[Comparative Example 1]

Comparative Example 1, except for the organic solvent-type conductive polymer and silver nanowires in the coating composition, increased the amount of the polyurethane-based resin by 0.5 wt%, and the additive including the wetting and dispersing agent was changed by increasing the amount by 0.4 wt% A coating composition was prepared in the same manner as in 1.

From this, the content of black pigment, infrared reflective pigment, and inorganic pigment, which have a relatively large effect on the infrared emissivity, is fixed, and the content of the organic solvent-type conductive polymer and silver nanowire in the paint composition has relatively little effect on the infrared emissivity. By comparing the low-infrared radiation performance of the coating composition of Comparative Example 1 in which the content of a small amount of resin and other additives was increased, and the coating composition of Example 1 comprising an organic solvent-type conductive polymer and a silver nanowire composite, the organic solvent-type conductive polymer and The infrared low-emission performance of the silver nanowire composite is confirmed.

Table 1 below shows the composition of the coating composition of Example 1 and Comparative Example 1. In Table 1 below, the content of each material represents the compositional content of the low-emissivity infrared coating composition with respect to 100% by weight of the total amount of solids excluding the organic solvent in the low-emissivity infrared coating composition.

Furtherance Example 1 Comparative Example 1 profit 47.0 wt% 47.5% by weight infrared reflective pigment 4.4 wt% 4.4 wt% black pigment 2.4% by weight 2.4% by weight inorganic pigment 1.8 wt% 1.8 wt% additive 16.5 wt% 16.9 wt% Organic solvent type conductive polymer 0.3% by weight - silver nanowires 0.6 wt% - aluminum flake 27.0 wt% 27.0 wt% Sum 100% by weight 100% by weight

In order to evaluate the physical properties of a coating film prepared by using the coating composition prepared in Example 1 and Comparative Example 1 as described above, a coating film specimen was prepared by the coating method described below.

(1) Undercoat coating: After coating the 0.8T CR material (base material) with an epoxy undercoat (DHCD-0690, NOROO Paint Co., Ltd.) to a thickness of about 50㎛, it was dried at 80°C for 2 hours.

(2) Example 1 and Comparative Example 1 coating composition coating: After coating once to a thickness of 40 to 50 μm, drying was performed at 80° C. for 4 hours, and then natural curing was performed at room temperature for 1 day.

1 and 2 show a state in which a coating film is formed by coating a substrate with an infrared low-emissivity coating composition according to whether or not an organic solvent-type conductive polymer and a silver nanowire composite are applied.

Specifically, FIG. 1 is a cross-sectional schematic view of a coating film coated on a base material using the infrared low emissivity paint composition of Comparative Example 1 without the organic solvent-type conductive polymer and the silver nanowire complex, and FIG. It is a schematic cross-sectional view of a coating film coated on a base material using a novel low-infrared low-emissivity coating composition to which a solvent-type conductive polymer and a silver nanowire composite are applied.

When a coating film is formed with the coating composition of Comparative Example 1 to which the organic solvent-type conductive polymer and the silver nanowire composite are not applied as in FIG. 1 , the aluminum flakes located on the surface of the coating film are infrared rays incident on the coating film. Ray), inorganic pigment particles, infrared reflecting pigment particles, and carbon black particles, which are black pigments, in the coating film are dispersed in polyurethane-based resin (PU Resin) and are dispersed in dark gray color. and a coating film is formed.

However, when forming a coating film with the infrared low-emissivity paint composition of Example 1 including the organic solvent-type conductive polymer and the silver nanowire composite as shown in FIG. It can be seen that organic solvent-type conductive polymer particles and silver nanowires are connected to each other to form a composite structure. In the present invention, the organic solvent-type conductive polymer and the silver nanowire composite are not in a form in which the organic solvent-type conductive polymer and the silver nanowire are chemically combined.

That is, silver nanowires act as micro conductors to form a complex with organic solvent-type conductive polymer particles of less than 1% by weight that are actually dispersed in the infrared low-emissivity paint composition to form a complex and connect them to each other and are located on the surface of the coating film A small amount of infrared energy absorbed by the organic solvent-type conductive polymer particles is transmitted through the silver nanowire connected to the base material located below the coating film, thereby preventing the infrared energy from being re-emitted to the outside of the coating film. make it possible to maximize

In order to evaluate the infrared spectral emissivity of the coating film specimen formed of the coating composition according to Example 1 and Comparative Example 1, the infrared spectral emissivity was measured in a wavelength range of 2 to 20 μm, and the results are shown in FIG. 3 .

As shown in FIG. 3 , the coating film specimen formed of the low-infrared emissivity coating composition of Example 1 including the organic solvent-type conductive polymer and the silver nanowire composite had infrared rays in the 3 to 5 μm mid-infrared wavelength band and the 8 to 12 μm far-infrared wavelength band. It was confirmed that the spectral emissivity value was significantly reduced compared to the coating film specimen formed of the coating composition of Comparative Example 1 which did not include the organic solvent-type conductive polymer and silver nanowires.

Table 2 below shows the infrared spectral emissivity and lightness index measured in the coating film specimens formed of the coating composition according to Example 1 and Comparative Example 2 of the present invention.

In Table 2, the infrared spectral emissivity shows the values of the infrared spectral emissivity measured in the 3 to 5 μm mid-infrared wavelength band and the 8 to 12 μm far-infrared wavelength band as in FIG. 3, and the brightness index is KS M 5000: conditions of 2014 According to the D65 light source, it is the value of the brightness index measured at a measuring angle of 45 degrees with respect to the transmitted light.

division Example 1 Comparative Example 1 Infrared spectral emissivity 3-5㎛ 0.54 0.56 8~12㎛ 0.62 0.70 lightness index (L*) 41.4 43.8

As shown in Table 2, the lightness index of the sample of Example 1 is 41.4, and the lightness index of the sample of Comparative Example 1 is 43.8, which is almost no difference, the dark color difference is not large, while the wavelength of 8㎛ to 12㎛ In the far-infrared region, the infrared spectral emissivity value of Example 1 is significantly decreased by about 0.1 compared to Comparative Example 1.

In the case of an infrared low-emissivity paint composition containing a dark black organic solvent-type conductive polymer, carbon black, which is a representative infrared absorbing pigment and a major factor in the increase of the infrared emissivity value in existing low-emissivity paint compositions, is used in a small amount. By doing so, the effect of low infrared emissivity can be improved, and even if the amount of carbon black is significantly reduced, a dark gray color similar to that of existing infrared low emissivity paints can be realized by the dark black organic solvent-type conductive polymer.

Therefore, the infrared low-emissivity paint composition having the organic solvent-type conductive polymer and the silver nanowire composite structure as in the present invention is more effective not only in the infrared stealth effect on detection of signal detection means such as radar detection, but also in visual monitoring (visible light band). It has an excellent camouflage effect.

The above-described embodiments are only preferred embodiments that enable those skilled in the art to easily practice the present invention, and are not limited to the above-described embodiments and the accompanying drawings. Therefore, it will be apparent to those skilled in the art that various substitutions, modifications, and changes can be made within the scope of the present invention without departing from the spirit of the present invention, and it is apparent that parts easily changeable by those skilled in the art are also included in the scope of the present invention.

Claims (14)

With respect to the total of 100% by weight of the infrared low emissivity paint composition,
20.0 to 50.0% by weight of a resin;
3.0 to 5.0% by weight of an infrared reflective pigment;
0.1 to 3.0% by weight of a black pigment;
1.0 to 5.0% by weight of an inorganic pigment;
1.0 to 20.0% by weight of an additive;
0.1 to 1.0% by weight of an organic solvent-type conductive polymer;
0.2 to 2.0% by weight of silver nanowires; and
20.0 to 40.0% by weight of aluminum flakes;
Infrared low-emissivity paint composition comprising a; residual amount of organic solvent. According to claim 1,
The organic solvent type conductive polymer,
A conductive polymer solution containing one or more polymers selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polypyrrole, and polyaniline or a conductive polymer that is a copolymer thereof is mixed with an organic solvent through a solvent substitution method. An infrared low-emissivity paint composition, characterized in that it is substituted with According to claim 1,
The resin is an infrared low-emissivity coating composition, characterized in that any one selected from the group consisting of a polyurethane-based resin, an acrylic resin, a polysiloxane-based resin, and a polyester-based resin and mixtures thereof. According to claim 1,
The aluminum flakes have an average particle size of 5 to 40 μm, characterized in that the infrared low-emissivity coating composition. According to claim 1,
The infrared reflective pigment is an infrared low emissivity paint composition, characterized in that the total reflectance is 40% or more in a wavelength region of 920 to 2500 nm. According to claim 1,
The additive is an infrared low-emissivity paint composition, characterized in that it contains any one or more of a wetting and dispersing agent and an ultraviolet stabilizer. According to claim 1,
The organic solvent is an infrared low-emissivity coating composition, characterized in that it comprises 30.0 to 45.0 wt% based on 100 wt% of the total composition. According to claim 1,
The low-infrared low-emissivity coating composition has an infrared low-emissivity coating composition, characterized in that the emissivity value is 0.6 or less in the infrared region having a wavelength of 3 to 12 μm. (a) preparing a resin, an infrared reflective pigment, a black pigment, an inorganic pigment, an additive, an organic solvent-type conductive polymer, silver nanowires, and aluminum flakes;
(b) forming a dispersion by dispersing the resin, the infrared reflective pigment, the black pigment, the inorganic pigment, the additive, the organic solvent-type conductive polymer, and the silver nanowire in an organic solvent;
(c) forming an aluminum flake solution by mixing the aluminum flakes in an organic solvent; and
(d) mixing the dispersion and the aluminum flake solution to obtain an infrared low-emissivity coating composition; 10. The method of claim 9,
The dispersion is based on a total of 100% by weight of the low-ultraviolet low-emissivity paint composition,
20.0 to 50.0 wt% of the resin;
3.0 to 5.0 wt% of the infrared reflective pigment;
0.1 to 3.0 wt% of the black pigment;
1.0 to 5.0 wt% of the inorganic pigment;
1.0 to 20.0% by weight of the additive;
0.1 to 1.0 wt% of the organic solvent-type conductive polymer;
0.2 to 2.0 wt% of the silver nanowire; and
The organic solvent is 2.0 to 15.0% by weight; low-ultraviolet low-emissivity coating composition manufacturing method comprising a. 10. The method of claim 9,
The aluminum flake solution is based on a total of 100% by weight of the low-ultraviolet low-emissivity coating composition,
20.0 to 40.0 wt% of the aluminum flakes; and
The method for producing a low-ultraviolet low-emissivity coating composition, characterized in that the organic solvent comprises 15.0 to 43.0% by weight. 10. The method of claim 9,
The organic solvent type conductive polymer,
A conductive polymer solution containing one or more polymers selected from the group consisting of polythiophene, poly(3,4-ethylenedioxythiophene), polypyrrole, and polyaniline or a conductive polymer that is a copolymer thereof is mixed with an organic solvent through a solvent substitution method. Infrared low-emissivity coating composition manufacturing method, characterized in that substituted with. 10. The method of claim 9,
The method for producing an infrared low-emissivity coating composition, characterized in that the resin is any one selected from the group consisting of a polyurethane-based resin, an acrylic resin, a polysiloxane-based resin, a polyester-based resin, and mixtures thereof. 10. The method of claim 9,
The additive is a method for producing an infrared low-emissivity coating composition, characterized in that it comprises at least one of a wetting and dispersing agent and an ultraviolet stabilizer.

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