JP4712802B2 - Film or building exterior material using self-cleaning coating composition and method for producing the same - Google Patents

Description

  The present invention relates to a coating composition having self-cleaning property (self-cleaning property), a substrate having excellent self-cleaning property and stain resistance obtained by using this composition, for example, a film or a building exterior material, and The present invention relates to these manufacturing methods.

  Conventionally, when advertising films and building exterior materials are exposed outdoors for a long time, contamination by dust, soot, and discoloration due to ultraviolet rays have been cited as serious problems. For this reason, physical properties such as self-cleaning properties and weather resistance that exhibit long-term reliability are particularly required for outdoor films and exterior materials.

  Contamination on the surface of outdoor films and building exterior materials is primarily due to combustion products such as dust or carbon black in urban air and inorganic materials such as viscous particles. Usually, the pollution source deposited on the surface of the outdoor film and the building exterior material may be washed away by rain that falls intermittently, and the outdoor film and the building exterior material may return to the original state. However, if a small amount of rain falls, it will be trapped in the rain and attached to the surface and will be present on the surface in the form of dust, contamination or mottle during drying. Furthermore, when it does not rain due to sunshine, the amount of pollutants generated in the atmosphere increases, and since no washing with rain is performed, a vicious cycle in which pollutants continue to accumulate is accelerated. Therefore, in order to solve such problems, the following anti-staining coating materials have been used conventionally.

  The most widely known method is a method using photocatalyst particles. Specifically, when ultraviolet light is applied to the surface of the photocatalyst particles, the surface exhibits strong hydrophilicity. This state continues for several hours to one week even after the light irradiation is stopped, but eventually returns to the state before the light irradiation, that is, the hydrophobic state. In addition, even after returning to the hydrophobic state, if it is irradiated with ultraviolet rays, it quickly recovers to a super hydrophilic one. In other words, the surface can be maintained in a super-hydrophilic state by intermittent light irradiation without continuing to perform light irradiation, and contamination resistance due to this can also be maintained. However, since the photocatalyst particles have a property of decomposing organic substances, there is a disadvantage that it is necessary to further perform primer coating on a plastic substrate such as a thermoplastic resin before performing photocatalytic coating.

  In addition, a water-repellent coating material containing a fluoro group such as polytetrafluoroethylene (PTFE) is said to be suitable for preventing contamination as described above. Since the water-repellent coating material has a low surface tension, it plays the role of washing away dust on the surface layer while water droplets on the surface of the formed coating move to the bottom, but the water droplets are small and cannot be moved by gravity. In some cases, it is dirty and dry, leaving a local contamination mark.

  Furthermore, a method of applying a hydrophilic graft hybrid polymer has been proposed, but the contact angle between conventional inorganic dust and water is 20 to 50 °, whereas the hydrophilic graft hybrid polymer is used. Since the water contact angle of the coating film is 30 to 40 ° (see, for example, the following Non-Patent Document 1), the hybrid polymer cannot efficiently wash off spots and contamination due to inorganic dust accumulated on the surface. . Also, easily available hydrophilic paints have a water contact angle of 50 to 70 °, so that there is a problem that contamination due to dust in the city center cannot be efficiently removed.

  On the other hand, products having a self-cleaning function and a stain resistance function have not been commercially available as conventional building exterior materials such as vinyl siding. In order to obtain the above-described characteristics, a stain-resistant coating is required, but since the vinyl siding base material is solid, there is a problem that it is difficult to mass-produce like a conventional roll type general film.

  Furthermore, the building exterior material is usually manufactured by a production line such as an extrusion stage, a molding and cooling stage, and a cutting stage, or a mass production line in which a separate process is selectively added between the processes, for example, It is manufactured by a mass production line such as an extrusion stage, an embossing process stage, a molding and cooling stage, a drilling stage, a tension adjusting stage and a cutting stage.

In order to give the building exterior material stain resistance, it is necessary to perform a separate coating operation after the mass production process as described above. In this case, a mass production line for coating is further required. This causes problems such as a decrease in yield and an increase in production cost during mass production, resulting in disadvantages in terms of cost and work space.
Newspace Dairy Chemical Industry, 30, 1995

  In view of the above problems, the present inventor, when mixing inorganic particles having a hydroxy group which is a hydrophilic group and inorganic particles having a particle size different from the above, improves hydrophilicity by initial hydrophilicity and surface roughness effect. As a result, it has been found that excellent self-cleaning properties can be obtained in which the rainwater film formed on the surface moves to the lower part and efficiently removes contaminants attached to the surface of the coating layer.

  Furthermore, when an organic solvent having a erodibility to a coating base material, for example, a building exterior material and a low boiling point is used as a solvent component of the coating composition, a separate coating process is applied to the mass production line of the above-described building exterior material. It has been found that the coating composition can be applied at any production stage without any additional.

  Then, an object of this invention is to provide the coating composition which gives the outstanding self-cleaning property, its manufacturing method, and the self-cleaning base material using this composition.

  Furthermore, another object of the present invention is to provide a method for producing a building exterior material having contamination resistance and self-cleaning property without adding a new mass production line to the mass production line of the building exterior material using the composition. There is a place to do.

  The present invention includes (a) inorganic particles having a hydroxy group having an average particle size of 5 to 30 nm, (b) inorganic particles having a hydroxy group having an average particle size of 0.2 to 5 μm, and (c) the following formula 1 The coating composition containing the organosilane represented by these, and (d) solvent, and its manufacturing method are provided.

  In the formula, R is an aminoalkyl group having 1 to 8 carbon atoms, a glycidoxyalkyl group or an isocyanate alkyl group, R ′ is a lower alkyl group having 1 to 6 carbon atoms, and n is 0 to 3 It is an integer.

  The present invention also provides a self-cleaning substrate, preferably a film, comprising: (a) a substrate; and (b) a coating layer formed by coating the coating composition on one or both sides of the substrate. Or provide building exterior materials.

  The present invention further includes (a) coating one or both sides of the building exterior material before the cooling step with a coating composition, and (b) cooling the building exterior material coated in the step (a). Or a step of cutting. A method for manufacturing a building exterior material is provided.

  Among the terms used in this specification and claims, lower means an atomic group or compound having 6 or less carbon atoms, preferably 5 or less.

  A lower alkyl group means a linear or branched lower saturated aliphatic hydrocarbon, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, isobutyl, t-butyl and n- There is a pentyl group.

  The coating composition according to the present invention is an excellent self-cleaning effect obtained by the hydrophilic group and the surface roughness effect by using two or more inorganic particles having a hydrophilic hydroxy group and different average particle diameters. Can be provided on outdoor films and building exterior materials. In addition, by using an organic solvent with a low boiling point, all plastic substrates including vinyl siding produced by the conventional extrusion process can be coated simultaneously on existing mass production lines, resulting in cost and space savings. can do.

  Therefore, the present invention reduces the labor and cost of regular cleaning by providing a clean appearance by providing a contamination prevention function due to self-cleaning to existing ordinary outdoor films and building exterior materials. The coating composition according to the present invention is expected to have a high industrial utility value.

  The present invention is described in detail below.

  1) In the present invention, excellent self-cleaning properties can be obtained by mixing inorganic particles having two or more different particle diameters having a hydroxy group as a constituent of a coating composition.

  In recent years, outdoor films and building exterior materials having stain resistance have mainly introduced photocatalytic particles or hydrophilic groups. In this case, a primer layer capable of protecting the substrate is required or partially There were problems such as side effects such as surface spots due to cleansing, and short-term durability.

  On the other hand, in the present invention, existing inorganic particles such as silica or alumina are dispersed in a dispersion such as water, alcohol or ketone to retain a hydroxy group, so that a water film when reaching the surface of water is obtained. Formability and wettability can be improved, and as a result, hydrophilicity can be obtained.

  In addition to the above-described method for introducing a hydrophilic group, the surface roughness, that is, by adding and mixing particles having an average particle size larger than that of a specific inorganic particle having a conventional hydroxy group, The hydrophilicity of the coating layer can be further increased.

  In addition, by forming a network structure by reaction with organosilane which is a constituent of the coating composition, it is possible to obtain wear resistance as well as the above-described hydrophilicity.

  2) In the present invention, as a solvent component of the coating composition, a part of the surface of a normal plastic substrate using a coating substrate, for example, an organic solvent having erodibility to building exterior materials and a low boiling point Is slightly eroded to form a structure in which the substrate and the coating layer are entangled with each other. Thereby, not only does the coating layer having self-cleaning properties stably exist, but also curing is likely to occur, and the above-described excellent stain resistance and self-cleaning properties can be obtained simultaneously for a long time.

  3) Furthermore, since the coating composition according to the present invention can be easily applied at any stage without adding a new coating mass production line to the conventional production process of building exterior materials, the cost and working space can be reduced. High economic efficiency can be achieved in this respect.

  That is, as shown in FIG. 1, a conventional mass production line for building exterior materials includes an extrusion stage, a relief processing stage, a molding and cooling stage, a drilling stage, a tension adjusting stage, and a cutting stage. In general, in the coating operation, drying and curing are performed after coating on the base material, and thus a further coating mass production line is required for coating the building exterior material, for example, vinyl siding. As a result, it is necessary to provide additional production equipment, which is costly.

  In the present invention, in order to perform the coating operation at the same time without providing further production equipment in the above-described building exterior material production line, preferably, immediately after the extrusion stage, that is, the surface of the exterior material has a high temperature. Coating is performed using the coating composition described above. At this time, the organic solvent having a low boiling point contained in the coating composition not only facilitates curing without further use of heat or an ultraviolet curing agent, but also at any stage of the production line described above. Installation of equipment and application of coating are possible.

Of the components of the coating composition according to the present invention, as the first inorganic particles (a), ordinary inorganic particles in the industry can be used, and non-limiting examples thereof include silica (SiO ₂ ), Alumina (Al ₂ O ₃ ), SnO ₂ , MgO, CaO or a mixture thereof.

  The average particle size of the first inorganic particles is preferably in the range of 5 to 30 nm, and preferably the average particle size is in the range of 10 to 20 nm. If the average particle size of the inorganic particles is less than 5 nm, there is a problem that the price competitiveness decreases due to high raw material costs. If the average particle size exceeds 30 nm, the particle size increases and the degree of particle packing decreases, and the strength of the film May decrease.

  The content of the inorganic particles having an average particle diameter of 5 to 30 nm is preferably 1 to 15% by weight, particularly 3 to 10% by weight, per 100% by weight of the coating composition according to the present invention. If the content of the inorganic particles having an average particle size of 5 to 30 nm is less than 1% by weight, the film strength of the film is lowered, and if it exceeds 15% by weight, the coating film is not formed normally.

  Among the constituent components of the coating composition according to the present invention, as the second inorganic particles (b), normal inorganic particles in the industry as described above can be used. The average particle size of the second inorganic particles is preferably in the range of 0.2 to 5 μm, and it is preferable to use inorganic particles having an average particle size of 1.5 to 2 μm depending on the surface roughness. The hydrophilicity can be increased, which is preferable. If the average particle size of the inorganic particles is less than 0.2 μm, there is a problem that the price competitiveness is reduced due to high raw material costs, and if it exceeds 5 μm, the storage stability of the coating composition may be defective. There is sex.

  The content of the inorganic particles having an average particle size of 0.2 to 5 μm is preferably 0.05 to 3% by weight per 100% by weight of the coating composition according to the present invention. If the content of the inorganic particles having an average particle size of 0.2 to 5 μm is less than 0.05% by weight, the hydrophilicity is lowered and the self-cleaning property is lowered. It is not preferable because defects such as peeling occur.

  As the inorganic particles (a) and (b) having different average particle diameters as described above, at least two kinds or more can be used. The inorganic particles preferably contain a hydrophilic functional group in the inorganic particles in order to increase hydrophilicity. For this purpose, it is preferable to use the inorganic particles dispersed in a solvent such as water, alcohol or ketone.

  The third component of the constituents of the coating composition according to the present invention is the organosilane (c) represented by the formula 1.

  Organosilane is a hydrophilic silane that increases adhesion to the substrate and combines with inorganic particles having two or more kinds of average particle diameters as described above to form organic / inorganic hybrid nano-network structure. Used as a system coupling agent.

  As the organosilane, tetraalkoxysilane or a silane having a hydrophilic functional group other than a hydroxy group after hydrolysis can be used, and in particular, a silane having one or two hydrophilic functional groups is preferably used. In the formula 1, the hydrophilic functional group means R in the chemical formula 1, and examples thereof include a glycidoxyalkyl group, an aminoalkyl group, and an isocyanate alkyl group. Further, in addition to these, a thiol group, an amine oxide group, a sulfoxide group, a phosphate group, a sulfate group or a salt thereof, or a hydrophilic group of polyoxyethylene or polyoxypropylene can be contained.

  In the above, non-limiting examples of hydrophilic silane include N-aminoethyl γ-aminopropyltrimethoxysilane, N-aminoethyl γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-amino. Examples include propyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-isocyanopropyltriethoxysilane, γ-isocyanopropyltrimethoxysilane, or a mixture thereof.

  The content of the organosilane is preferably 1 to 15% by weight per 100% by weight of the coating composition according to the present invention. If the content of the organosilane is less than 1% by weight, a film coating film is not formed, and if it exceeds 15% by weight, the hydrophilicity is lowered.

  The fourth component of the constituents of the coating composition according to the present invention is the solvent (d), and water, organic solvents, mixtures thereof, or the like that are common in the industry can be used.

As the solvent, a solvent containing an organic solvent having a solubility index (δ) of 9.5 Mpa ^0.5 or less with respect to a coating substrate, preferably a general plastic such as PVC, is suitably used. This is because the coating substrate and the coating layer are firmly bonded to each other by having some erosion properties when coating on the coating substrate. Moreover, as said solvent, in order to harden | cure easily by a low boiling point, what contains the 1 or more types of organic solvent whose average boiling point (bp) is the range of 60-150 degreeC is used suitably. It is done.

  Usable organic solvents include alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol or diacetone alcohol, and 1 to 5 carbon atoms such as methyl ethyl ketone or methyl isobutyl ketone. Ketones, acetates such as methyl acetate or ethyl acetate, cellosolves having 4 to 6 carbon atoms, aromatic solvents having 7 carbon atoms or mixtures thereof, but are not limited thereto. Absent.

  Although there is no restriction | limiting in particular in the content of the said solvent, It is preferable that it is the range of 50 to 85 weight% per 100 weight% of the coating composition which concerns on this invention. If the content of the solvent is less than 50% by weight, uncured may occur, and if it exceeds 85% by weight, the hydrophilicity may decrease.

  The coating composition according to the present invention may further include photocatalyst particles.

  Photocatalyst particles are substances that generate a highly active substance by light energy applied to the catalyst and promote a chemical reaction. When light exceeding the band gap energy is applied, electrons and holes are generated, which are stronger. An oxidation-reduction reaction occurs. During the oxidation-reduction process, organic chemicals are decomposed into harmless carbon dioxide and water, thereby reducing the adhesion of floating dust to the surface of the coating layer. Further, it is possible to prevent the deterioration of the hydrophilicity over time due to the condensation of the hydrophilic groups on the surface and to achieve the hydrophilic sustainability.

  When ultraviolet light is applied to the surface of the photocatalyst particles, the surface is strongly hydrophilic. This state is maintained for several hours to one week even when the light irradiation is stopped, and gradually returns to the hydrophobic state before the light irradiation. In addition, even after returning to hydrophobicity, it is restored to super hydrophilicity immediately when irradiated with ultraviolet rays. That is, the surface can be maintained in a super hydrophilic state by intermittent light irradiation without always performing light irradiation. For this reason, when photocatalyst particles are added to the coating composition according to the present invention to coat a coating base material, preferably an advertising film or a building exterior material, not only hydrophilicity occurs due to daytime sunlight irradiation. , The hydrophilicity can be maintained continuously.

Non-limiting examples of usable photocatalytic particles include anatase titanium dioxide, rutile titanium dioxide, stannic oxide, tungsten trioxide, ferric oxide, strontium titanate, ZnO, SnO ₂ , SrTiO ₃ , WO ₃ , Bi ₂ O ₃ , Fe ₂ O _3, or a mixture thereof may be mentioned, and among these, titania (TiO ₂ ) is most suitable. Since titania has a high band gap energy, it requires ultraviolet rays at the time of photoexcitation, and does not absorb visible light during photoexcitation, so that no coloration due to a complementary color component occurs.

Examples of the light source used for exciting the photocatalyst particles include indoor lighting such as a fluorescent lamp, an incandescent lamp, and a mercury lamp, and the sun. Specifically, the illuminance of photoexcitation is preferably 0.001 mW / cm ² or more, and particularly preferably 0.1 mW / cm ² .

  The average particle size of the photocatalyst particles is preferably in the range of 10 to 80 nm, particularly preferably 15 to 60 nm. If the average particle size of the photocatalyst particles is less than 10 nm, there is a problem that the price competitiveness is reduced due to high raw material costs, and if it exceeds 80 nm, there is a problem of transparency of the film (cause of whitening) due to light scattering by the particle size. Arise.

  The content of the photocatalyst particles is preferably 0.1 to 3% by weight per 100% by weight of the coating composition according to the present invention. If the content of the photocatalyst particles is less than 0.1% by weight, the hydrophilicity is lowered and the self-cleaning property is lowered, and if it exceeds 3% by weight, defects such as cracking and peeling of the coating film are not preferable. .

  Furthermore, the coating composition according to the present invention may further include a hydrolyzate of an alkoxysilane functionalized aromatic ultraviolet absorber represented by the following formula 2.

In the formula, R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, R ₃ is an alkyl group or aryl group having 1 to 6 carbon atoms, OR ₄ is methoxy, ethoxy, Propoxy, isopropoxy, butoxy or acetoxy, R ₅ is an alkyl or aryl group having 1 to 12 carbon atoms, X is a hydrogen or halogen atom, l is an integer of 5 to 9, and m is It is an integer of 1-3, n is an integer of 0-2.

  The hydrolyzate of the alkoxysilane functionalized UV absorber as described above binds to the organosilane to maximize the compatibility of the coating composition, and is resistant to long-term weathering by chemical bonding with the matrix silane. Makes it possible to preserve sex. A method for producing a hydrolyzate of this ultraviolet absorber is disclosed in Korean Patent Publication No. 2000-0009647.

  The content of the hydrolyzate of the alkoxysilane functionalized UV absorber is preferably 1 to 10% by weight per 100% by weight of the coating composition according to the present invention. If the content of the hydrolyzate of the alkoxysilane functionalized UV absorber is less than 1% by weight, the effect of absorbing UV rays is reduced. If the content exceeds 10% by weight, problems such as reduced economic efficiency occur.

  The coating composition according to the present invention may further contain an acid, a curing agent, a polyurethane aqueous emulsion or other additives in addition to the above-described components.

  The coating composition according to the present invention can be produced by an ordinary method in the art. For example, as one embodiment, (a) adding inorganic particles having an average particle diameter of 5 to 30 nm to a dispersion medium. A step of mixing to obtain an inorganic particle dispersion; and (b) an inorganic particle having an average particle size of 0.2 to 5 μm in the inorganic particle dispersion obtained in the step (a), an organosilane represented by the formula 1 And a step of mixing and reacting an acid and a solvent and a step of (c) adding an organic solvent to the reaction product of the step (b) and reacting the mixture.

  First, 1) An inorganic particle dispersion having an average particle diameter of 5 to 30 nm having a hydroxy group as a hydrophilic group is obtained by mixing 1 to 15% by weight of the inorganic particles and 15 to 30% by weight of a dispersion medium.

  At this time, water, alcohol, ketone, etc. can be used as a dispersion medium used for the production of the dispersion of inorganic particles, and uniform mixing with the organic solvent used thereafter, and easy curing due to a low boiling point. In addition, alcohols such as methanol are preferably used in order to have a hydroxy group that is a hydrophilic functional group. However, a normal solvent may be used as long as it does not exceed the scope of the present invention.

  The solid content of the inorganic particle dispersion having a hydroxy group is preferably in the range of 10 to 40% by weight, particularly preferably 15 to 35% by weight.

  2) The obtained inorganic particle dispersion having an average particle diameter of 5 to 30 nm having an hydroxy group of 1 to 15% by weight and alcohol of 15 to 30% by weight and inorganic particles having an average particle diameter of 0.2 to 5 μm 0.05 to 2 1% to 10% by weight of an organosilane, 0.001 to 2% by weight of an acid and a solvent as a hydrolysis catalyst, and after adding and mixing a solvent, a sol-gel reaction is performed at a temperature of 20 to 80 ° C. for 1 to 48 hours. Allow to cool to room temperature.

  As described above, the inorganic particles having an average particle size of 0.2 to 5 μm can be used for adjusting the hydrophilicity and the surface roughness, and the particle size and type of the inorganic particles are not limited.

  The reaction temperature and time are preferably 20 to 80 ° C. and 1 to 48 hours, respectively, and particularly preferably 25 to 60 ° C. and 5 to 24 hours.

  In the above, the acid serves as a reaction catalyst, and non-limiting examples thereof include hydrofluoric acid, nitric acid, hydrochloric acid, acetic acid, sulfur acid, and mixed acids thereof. The amount of the acid used is preferably in the range of 0.001 to 2% by weight per 100% by weight of the coating composition according to the present invention, but is not limited thereto. The acidity (pH) of the acid-containing reaction product is preferably adjusted to 1 to 5. If the pH is 6 or more, adhesion to the substrate may not be obtained, or there may be a problem in coating properties such as whitening.

  3) After adding an organic solvent to the reaction product, the reaction is maintained at room temperature for 1 hour.

  In the production step, 1 to 4% by weight of a thermosetting catalyst may be added to the reaction result before adding the organic solvent.

  The thermosetting catalyst changes the structure of the organosilane so that it can form a nano-network structure by combining with inorganic particles, and plays a role of curing even at a relatively short curing time (2 minutes) at 90 ° C. . Usually, thermosetting catalysts are basic, so when adding to a dispersion of inorganic particles in an acidic state, after appropriate stirring, add a small amount in a diluted state of about 10% by weight with respect to a soluble solvent. Without local gelation cannot be prevented.

  Non-limiting examples of thermosetting catalysts that can be used include alkali metal salts of carboxylic acids such as sodium acetoate or potassium formate and carboxylic acid amine salts such as dimethylamine acetate, ethanolamine acetate or dimethylaniline formate. A carboxylic acid quaternary ammonium salt such as tetramethylammonium acetate, benzyltrimethylammonium acetate or ethanoltrimethylacetate (choline acetate), an amine such as triethylamine, triethanolamine or paraffin, or sodium hydroxide, ammonium hydroxide, etc. There are alkali hydroxides.

  The amount of the thermosetting catalyst used is preferably 1 to 10% by weight per 100% by weight of the coating composition according to the present invention. If the amount of the thermosetting catalyst used is less than 1% by weight, the strength of the coating film decreases, and if it exceeds 10% by weight, problems such as a decrease in storage stability of the coating liquid itself occur.

  In the above-mentioned production stage, by adding 1 to 10% by weight of the hydrolyzate of the alkoxysilane functionalized aromatic ultraviolet absorbent represented by the formula 2 to the sol-gel reaction result before adding the organic solvent, weather resistance Can be achieved. At this time, after adding the hydrolyzate of the ultraviolet absorber, it is preferable to stir at room temperature for 1 to 2 hours. Moreover, in order to improve hydrophilicity, aminosilane 0.001-1weight% can be added and hydrophilicity can also be improved.

In the production step, hydrophilic sustainability, abrasion resistance and scratch resistance can be enhanced by further using 0.1 to 3% by weight of the photocatalyst particle dispersion and / or 1 to 10% by weight of the polyurethane aqueous emulsion. At this time, the photocatalyst particle dispersion can be produced using titania (TiO ₂ ) having an average particle diameter of 10 to 80 nm and an appropriate amount of solvent, and the solid content is preferably 15% by weight. is there. Moreover, as a polyurethane aqueous emulsion, the aqueous emulsion polyurethane resin which has polyester as a principal chain can be used, and it is preferable that the usage-amount is 1 to 10 weight% per 100 weight% of coating compositions.

  In addition, in the above production stage, in order to improve the coating property and the slipperiness, 0.001 to 0.5% by weight of a surfactant can be selectively used. Besides this, other additives, that is, Various surfactants, water resistance improvers, antioxidants, lubricants, heat absorbers, colorants, antistatic agents, plasticizers, and other additives can be further used. If necessary, in order to improve the smoothness of the film, leveling agents, wetting agents to weaken the surface tension of the composition and improve the wettability to the substrate, UV absorbers, leveling agents, radiation blocking An additive such as an agent (infrared absorbing agent or infrared reflecting agent) can be further included. As the surfactant, any one or more of a nonionic surfactant, an anionic surfactant, a cationic surfactant and an amphoteric surfactant can be used.

  The dosage form of the coating composition thus obtained is not particularly limited, and can be used mainly in a liquid form for convenience of use.

  The present invention provides a self-cleaning substrate comprising: (a) a substrate; and (b) a coating layer formed by coating the coating composition on one or both surfaces of the substrate.

  As the substrate, all kinds except water and air can be used. Non-limiting examples of such a substrate include building exterior materials, tiles, plastics, glass, resins, films, ceramics, metals, There are concrete, fiber, wood, paper, stone, and the like, and in particular, ordinary plastics in the industry can be used without limitation for films, resins, building exterior materials and the like. Among these, a film or a building exterior material is preferably used.

  There is no restriction | limiting in particular in the film thickness of the self-cleaning coating layer formed on the surface of a base material, It is preferable that it is the range of 0.01-50 micrometers. If the film thickness of the coating layer is less than 0.01 μm, the film hardness is poor, and if it exceeds 50 μm, there is a problem that the flexibility of the coating layer is lowered and the coating film is cracked.

  There is no particular limitation on the method for producing the self-cleaning substrate according to the present invention, and for example, it is produced by coating one or both sides of the coating substrate with the coating composition and then drying the coated substrate. Just do it.

  As a coating method of the coating composition, a normal coating method in the industry may be used, and there is no particular limitation. Examples of the coating method include air-knife method, gravure method, reverse roll method, kiss roll method, doctor blade method, spray method, dipping method, brushing method, bar coating method, spin coating method or a mixture method thereof. it can. The curing conditions are preferably 4 seconds to 2 minutes at 60 to 150 ° C., but are not particularly limited. If the curing temperature is less than 60 ° C., the film cannot be completely dried, and if it exceeds 150 ° C., the coating film and the substrate are deteriorated.

  Moreover, this invention provides the manufacturing method of the building exterior material obtained through an extrusion step. The manufacturing method includes, for example, (a) a step of coating one or both sides of the building exterior material before the cooling step with a coating composition, and (b) the building exterior material coated in the step (a). Cooling or cutting.

  The point to be noted in the production method is that the surface temperature of the building exterior material immediately after the extrusion (a) stage is as high as about 100 to 250 ° C., so that the coating layer can be dried and cured until entering the cooling water. It is. For this reason, it is possible to carry out the coating before the cooling stage, for example, the extrusion stage, the embossing process stage and the molding stage, preferably immediately after the extrusion stage, that is, at a high temperature where the surface of the exterior material is in the range of 100 to 250 ° C. preferable. However, it is not particularly limited to the temperature range, and may be performed at room temperature. In addition to the above method, the installation of the coating equipment and the addition of the coating stage can be performed at any stage of the whole process of building exterior materials, for example, extrusion-relief processing-forming and cooling-drilling-tension adjustment-cutting stage. Is possible.

  From the above-described features, the method for manufacturing a building exterior material according to the present invention not only requires heat curing or ultraviolet curing, but also installs a separate coating line, and a space for the installation. Is no longer necessary. In addition, a coating step can be easily added to a production line for conventionally used building exterior materials such as vinyl siding.

The said manufacturing method is applicable to all the plastic base materials obtained by an extrusion process. Further, the coating composition is not particularly limited, and the coating composition can provide physical properties that are desired to be given to the building exterior material through the coating process, for example, stain resistance, self-cleaning property, weather resistance, scratch resistance or other physical properties. Compositions can be used. In particular, the composition has an average boiling point (bp) as low as 60 to 150 ° C. in order to facilitate the occurrence of curing due to a low boiling point and to form a firm coating layer due to erosion, or It is preferable that an organic solvent having a solubility index (δ) of 9.5 Mpa ^0.5 or less is included. For this reason, it is preferable to use the coating composition according to the present invention containing the organic solvent component as described above, and when the building exterior material is manufactured by the coating composition according to the present invention, the coating composition is It is possible to simultaneously achieve the desired excellent stain resistance and self-cleaning properties.

  The coating methods that can be used are as described above. The thickness of the coating layer of the obtained building exterior material is preferably about 0.01 to 50 μm, and particularly preferably 0.5 to 20 μm.

  The curing conditions are appropriate if the surface temperature of the exterior material immediately after the extrusion step is 100 to 250 ° C. and the curing time after coating is 4 seconds or more. If the curing time is 4 seconds and the curing temperature is 100 ° C. or less, the film may be undried and uncured, and if it exceeds 250 ° C., the hydrophilicity is lowered.

  Hereinafter, preferred examples will be given to facilitate understanding of the present invention. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is limited to the following examples. There is nothing.

Manufacturing example. Synthesis of Hydrolyzate of Alkoxysilane Functionalized Aromatic UV Absorber Mixing 30.5% by weight of Tinuvin 1130 (Tinvin 1130, manufactured by Ciba-Gaigi Co., Ltd.) as a benzotriazole-based UV absorber and 42% by weight of acetone is a reactor And stirred while maintaining the internal temperature of the reactor at 55 to 57 ° C. To this mixture, 11.5% by weight of γ-isocyanatopropyltriethoxysilane was dropped for 30 minutes, and then reacted at a temperature of 55 to 57 ° C. for 90 minutes. Next, 11% by weight of glycidoxypropyltrimethoxysilane was added thereto and reacted at 55 to 57 ° C. for 30 minutes. By adding 5% by weight of water to this solution and reacting at a temperature of 55 to 57 ° C. for 2 hours, a hydrolyzate of an alkoxysilane functionalized ultraviolet absorber was obtained. At this time, the solid content of the obtained hydrolyzate was 52%.

[Example 1-7]. Production Example 1 of Coating Composition, Advertising Paper and Building Exterior Material Using the Composition
1-1. Coating composition 9% by weight of methanol-dispersed silica dispersion (MA-ST, manufactured by Ilsan Chemical Co., Ltd.) having an average particle size of 10 to 20 nm with a solid content of 30% (2.7% by weight of silica and 6.3% of methanol Weight%) and silica particles having an average particle size of 1.7 μm (Fine Seal T-32, manufactured by Tokuyama Corporation) 0.09 wt%, 10% concentration of nitric acid 0.01 wt%, water 1.01 wt%, methanol 18 wt% and glycidoxypropyltrimethoxysilane 1.89 wt% were added and reacted at 50 ° C. for 24 hours, then at room temperature, ethyl acetate (EA) 10 wt%, methyl ethyl ketone (MEK) 54.5 wt% After gradually adding 5% by weight of toluene, the mixture was stirred for 1 hour to obtain a coating composition.

1-2. Fabrication of stain resistant building exterior material The coating composition obtained according to Example 1 was used immediately after the embossing stage of the vinyl siding mass production line (LG Chemical Co., LG Side On), using the spray coating method. Thus, a stain-resistant vinyl siding was obtained by coating to a dry thickness of 2 μm.

Example 2
Instead of the embossing process, a stain-resistant vinyl siding was obtained in the same manner as in Example 1 except that the vinyl siding substrate (LG Chemicals, LG Side-on) was coated at room temperature.

Example 3
3-1. Production of Coating Composition 32% by weight of water-dispersed silica dispersion (ST-C, manufactured by Ilsan Chemical Co., Ltd.) having an average particle size of 20 nm and a solid content of 20% (6.4% by weight of silica and 25.6% by weight of water) %) And silica particles having an average particle size of 1.7 μm (Fine Seal T-32, manufactured by Tokuyama) 0.56% by weight, 67% nitric acid 0.05% by weight, water 60.62% by weight, glycid A coating composition was obtained by adding 4.48% by weight of xylpropyltrimethoxysilane, 0.37% by weight of ethylenediamine as a thermosetting catalyst and 1.92% by weight of choline acetate, and stirring at room temperature for 3 hours.

3-2. Production of Advertising Paper Coating composition obtained in accordance with Example 3-1 was coated on white PVC advertising paper (LG Chemical Co., Hi-Cast) using a bar coating method to a dry thickness of 1 μm. After that, an advertising paper was produced by curing at 90 ° C. for 2 minutes.

Example 4
4-1. Production of Coating Composition 32% by weight of water-dispersed silica dispersion (ST-C, manufactured by Ilsan Chemical Co., Ltd.) having an average particle diameter of 20 nm and a solid content of 20% (6.4% by weight of silica and 25.6% of methanol) % Silica) (fine seal T-32, manufactured by Tokuyama) 0.56% by weight, 67% nitric acid 0.05% by weight, water 40.62% by weight, A coating composition was obtained by adding 4.48% by weight of sidoxypropyltrimethoxysilane, 0.37% by weight of ethylenediamine as a thermosetting catalyst and 1.92% by weight of choline acetate and stirring at room temperature for 3 hours. . The coating was made by mixing 20% by weight of a titania (ST-21, made by Isahara Sangyo Co., Ltd.) aqueous dispersion having a solid content of 15% and a solid content of 15% (TiO ₂ 3% by weight, water 17% by weight). A composition was obtained.

4-2. Production of Advertising Paper Advertising paper was produced in the same manner as in Example 3-2 except that the coating composition obtained according to Example 4-1 was used.

Example 5
5-1. Production of Coating Composition 32% by weight of water-dispersed silica dispersion (ST-C, manufactured by Ilsan Chemical Co., Ltd.) having an average particle size of 20 nm and a solid content of 20% (6.4% by weight of silica and 25.6% of water) 0.56% by weight of silica particles (Fine Seal T-32, manufactured by Tokuyama Corporation), 4.48% by weight of glycidoxypropyltrimethoxysilane, and 0% nitric acid having a 67% concentration. The reaction was held at 50 ° C. for 24 hours after adding .05 wt% and 31.5 wt% water to the reactor. Next, the mixture was cooled to room temperature, and 0.37% by weight of ethylenediamine and 1.92% by weight of choline acetate as thermosetting catalysts were added and stirred at room temperature for 3 hours. To this solution, 0.28% by weight of aminopropylethoxysilane, 0.19% by weight of a surfactant (BYK333, manufactured by BYK Chemie) and 4.16% by weight of methyl cellosolve were added and stirred at room temperature for 1 hour. 20% by weight of titania (ST-21, manufactured by Isahara Sangyo Co., Ltd.) aqueous dispersion having a solid content of 15% and an average particle size of 40 nm (TiO ₂ 3% by weight, water 17% by weight), 10% solids polyurethane A coating composition was obtained by mixing 3% by weight of a resin (PESA160-P, manufactured by Takamatsu) and 1.5% by weight of an ultraviolet absorber obtained according to the above production example.

5-2. Production of Advertising Paper Advertising paper was produced in the same manner as in Example 3-2 except that the coating composition obtained according to Example 5-1 was used.

Example 6
6-1. Production of Coating Composition A coating composition was obtained in the same manner as in Example 5 except that silica particles having an average particle diameter of 3 μm were used instead of silica having an average particle diameter of 1.7 μm. .

6-2. Production of Advertising Paper Advertising paper was produced in the same manner as in Example 3-2 except that the coating composition obtained according to Example 6-1 was used.

Example 7
7-1. Production of coating composition Instead of 0.56% by weight of silica particles having an average particle size of 1.7 μm and 31.5% by weight of water, 1.12% by weight of silica particles having an average particle size of 1.7 μm and 30 of water A coating composition was obtained in the same manner as in Example 5 except that .94% by weight was used.

7-2. Production of Advertising Paper Advertising paper was produced in the same manner as in Example 3-2 except that the coating composition obtained according to Example 7-1 was used.

[Comparative Example 1-9]. Production Comparative Example 1 of Coating Composition, Advertising Paper and Exterior Material Using the Composition
A coating composition and a vinyl siding using the composition were produced in the same manner as in Example 1 except that silica having an average particle size of 10 to 20 nm was not used.

Comparative Example 2
A coating composition and a coated vinyl siding using the composition were prepared in the same manner as in Example 1 except that silica having an average particle size of 1.7 μm was not used.

Comparative Example 3
A coating composition and a coated vinyl siding using the composition were prepared in the same manner as in Example 1 except that 10% water and 90% ethanol were used as solvents.

Comparative Example 4
Coating was carried out in the same manner as in Example 5 except that 20% by weight of silica (ST-21, manufactured by Isahara Sangyo Co., Ltd.) aqueous dispersion having a solid content of 15% and an average particle diameter of 15% was not used. Composition and advertising paper using the composition were produced.

Comparative Example 5
A coating composition and an advertising paper using the composition were produced in the same manner as in Example 5 except that silica having an average particle size of 20 nm was not used.

Comparative Example 6
A coating composition and an advertising paper using the composition were produced in the same manner as in Example 5 except that the hydrolyzate of the UV absorber was not used.

Comparative Example 7
A coating composition and an advertising paper using the composition were prepared in the same manner as in Example 5 except that silica particles having an average particle diameter of 90 nm were used instead of silica particles having an average particle diameter of 20 nm. Manufactured.

Comparative Example 8
Example 1 except that 40% by weight of the aqueous photocatalyst particle dispersion (6% by weight of TiO ₂ and 34% by weight of water) was used instead of 20% by weight of the aqueous silica dispersion having a solid content of 15%. In the same manner as in Method 5, a coating composition and an advertising paper using the composition were produced.

Comparative Example 9
A coating composition and an advertising paper using the composition were prepared in the same manner as in Example 5 except that silica particles having an average particle diameter of 20 nm and silica having an average particle diameter of 1.7 μm were not used. Manufactured.

Experimental Example 1 Evaluation of hydrophilicity and hydrophilic sustainability In order to evaluate the hydrophilicity and hydrophilic sustainability of the advertising paper and the building exterior material manufactured using the coating composition according to the present invention, the following measurements were performed.

  The surface contact angle was measured after 1 month, 3 months, and 6 months after each sample was placed outdoors, and measured with a contact angle measuring instrument of Cruz.

1-1. As a building exterior material sample, vinyl siding manufactured according to Examples 1 and 2 and Comparative Examples 1 to 3 was used, and the results measured by the above method are shown in Table 1 below.

  As a result of the experiment, the vinyl siding of Comparative Example 1 manufactured using a coating composition that did not use 10 to 20 nm particles among inorganic particles having different average particle diameters, and Comparative Example 3 in which the composition of the solvent was adjusted The vinyl siding was found to have low hydrophilicity (see Table 1). In particular, in the case of Comparative Example 1, it was found that there was no hydrophilic effect due to the hydrophilic group on the surface of the nanosilica particles. Furthermore, in the case of the vinyl siding of Comparative Example 3, the coating layer is not normally formed on the substrate due to the high boiling point (bp) or low erodibility, and as a result, the hydrophilicity is poor. To be judged. Furthermore, it turns out that the vinyl siding of the comparative example 2 which did not use a 1.7 micrometer silica is inferior to the case of Example 1 in hydrophilicity. This is considered to be due to a decrease in hydrophilic groups and surface roughness on the surface of the silica particles.

  On the other hand, the vinyl siding coated with the composition obtained according to Example 1 and Example 2 was confirmed to have not only the highest initial hydrophilicity but also excellent hydrophilic durability (Table). 1).

1-2. Advertising paper As the sample, advertising paper manufactured according to Examples 3 to 7 and Comparative Examples 4 to 9 was used, and the results measured by the method are shown in Table 2 below.

  As a result of the experiment, the advertisement papers of Example 3 and Comparative Examples 4, 5, and 9 respectively produced using the coating composition without using the photocatalyst particles showed a water contact angle of about 22 to 60 °, All the advertising paper except this showed a water contact angle of 5 ° or less. In particular, the advertising paper of Comparative Example 9 that did not use any one of the two types of inorganic particles having different average particle diameters of the present invention and did not use the photocatalyst particles did not use only the photocatalyst particles. Compared with the advertising paper of Comparative Example 5, not only the initial hydrophilicity but also the hydrophilic durability was the lowest. This means that two types of inorganic particles having different average particle sizes are influencing factors of hydrophilicity and hydrophilicity persistence.

  From this, it has confirmed that the coating composition which concerns on this invention showed the outstanding hydrophilic property and hydrophilic persistence (refer Table 2).

Experimental Example 2. Evaluation of self-cleaning properties In order to evaluate the self-cleaning properties of advertising papers and building exterior materials produced using the coating composition according to the present invention, the following measurements were performed.

  As a measuring method, earth and sand having an average particle size of 10 μm were dispersed in water with a solid content of 5%, then sprayed on vinyl siding or advertising paper as a sample, dried, and further sprayed with distilled water. After 6 months, the amount of earth and sand remaining on the surface of the advertising paper is visually observed. Excellent (clean), good (slightly dirty), insufficient (dirty) Shown as bad (very dirty).

2-1. As a building exterior material sample, vinyl siding manufactured according to Examples 1 and 2 and Comparative Examples 1 to 3 was used, and the results measured by the above method are shown in Table 3 below.

  As a result of the experiment, the coating composition in which 10 to 20 nm particles were not used among the inorganic particles having different average particle diameters was almost the same as the results of the hydrophilicity and hydrophilicity sustainability that were already evaluated as a whole. It was found that the vinyl siding of Comparative Example 1 produced by using the above exhibited poor self-cleaning properties. On the other hand, the vinyl siding manufactured according to Example 1 and Example 2 has confirmed having the outstanding self-cleaning property (refer Table 3).

2-2. Advertising paper As the sample, advertising paper manufactured according to Examples 3 to 7 and Comparative Examples 4 to 9 was used, and the results measured by the above method are shown in Table 4 below.

  As a result of the experiment, the advertising papers of Example 3 and Comparative Example 4 manufactured using the coating composition without using the photocatalyst particles showed insufficient self-cleaning properties. Further, the advertising paper of Comparative Example 5 using photocatalyst particles and not using inorganic particles having an average particle diameter of 1.7 μm showed good self-cleaning properties, and the average particle diameter was different from that of the photocatalyst particles. The advertising paper of Comparative Example 9 that did not use any one of the inorganic particles showed poor self-cleaning properties. This is because the coating composition using inorganic particles having an average particle size of one kind shows hydrophilicity due to hydroxy groups, but does not significantly improve hydrophilicity due to surface roughness, and is self-cleaning. Means lower. On the other hand, it was confirmed that the coating composition according to the present invention using inorganic particles having two kinds of average particle diameters had excellent self-cleaning properties (see Table 4).

Experimental Example 3. Evaluation of weather resistance In order to evaluate the weather resistance of the advertising paper and the building exterior material manufactured using the coating composition according to the present invention, the following measurements were performed.

  A vinyl siding or advertising paper as a sample was tested for 1000 hours using a QUV accelerated weathering tester (UVB313 lamp, 60 ° C.), and the yellowing degree (ΔYellow Index) and occurrence of cracks were measured. .

3-1. As a building exterior material, vinyl siding manufactured according to Examples 1 and 2 and Comparative Examples 1 to 3 was used as a sample. The results measured by the above method are shown in Table 5 below.

  As a result of the experiment, it was found that all the vinyl sidings produced according to the examples and comparative examples had no cracks and had a relatively good yellowing degree (see Table 5).

3-2. Advertising paper Advertising paper manufactured according to Examples 3 to 7 and Comparative Examples 4 to 9 was used as a sample, and the results measured by the above method are shown in Table 6 below.

  As a result of the experiment, all the advertising papers coated with the coating compositions obtained according to Examples 3 to 7 and Comparative Examples 4 to 9 according to the present invention exhibited a relatively excellent degree of yellowing (see Table 6). ). Among these, the advertising papers coated with the coating compositions of Example 3, Example 4 and Comparative Example 6 that did not use an ultraviolet absorber showed a slightly higher degree of yellowing, but other physical properties, There was no sign of reduced weather resistance.

  From this, it was confirmed that the advertising paper produced using the coating composition according to the present invention has excellent self-cleaning properties and excellent weather resistance.

Experimental Example 4 Evaluation of scratch resistance In order to evaluate the scratch resistance of the building exterior material manufactured using the coating composition according to the present invention, the following measurements were performed.

  As a sample, vinyl siding manufactured according to Example 1, Example 2 and Comparative Examples 1 to 3 was used. As a measuring method, a steel wool (# 0000) test was performed, and a scratch of 200 g load was measured. A method of measuring the number of occurrences was used. The results are shown in Table 7 below.

  As a result of the experiment, the composition of the vinyl siding and the organic solvent of Comparative Example 1 manufactured using a coating composition that did not use 10 to 20 nm silica particles of two kinds of inorganic particles having different average particle diameters was used. It was confirmed that the changed vinyl siding of Comparative Example 3 was inferior in scratch resistance. This is because the organic solvent has a high boiling point (bp) or low erodibility, so that the network structure of the coating layer is not normally formed on the vinyl siding substrate, resulting in low scratch resistance. It means that.

  On the other hand, it was confirmed that the vinyl siding manufactured according to Examples 1 and 2 showed excellent scratch resistance (see Table 7).

Experimental Example 5. Evaluation of Turbidity The turbidity of the coating composition obtained according to the present invention was evaluated as follows.

  As a sample, advertising paper manufactured according to Examples 3 to 7 and Comparative Examples 4 to 9 was used. The measurement is performed on the transparent PVC film as a sample by using a reflection / transmission measuring device (HR-100, manufactured by Murakami Co., Ltd.) according to the ASTM D-1003 method. This was done by measuring. The results are shown in Table 8 below.

  In general, in order to obtain an effect of preventing glare, it is necessary to reduce glossiness and increase turbidity. From the viewpoint of visibility, it is said that turbidity of outdoor advertising materials is allowed up to 20%.

  As a result of the experiment, the advertising paper of Example 5 coated with the coating composition obtained according to the present invention has a turbidity of about 10, whereas the advertising paper produced by the comparative example has a value of 5-20. (See Table 8).

Experimental Example 6. Evaluation of glossiness The glossiness of the coating composition obtained according to the present invention was evaluated as follows.

  As a sample, advertising paper manufactured according to Examples 3 to 7 and Comparative Examples 4 to 9 was used. As a measuring method, a gloss measuring instrument of BYK Gardner was used for a transparent PVC film as a sample. The method of measuring the glossiness of the surface by measuring the relative value of 60 ° reflected light with respect to 60 ° incident light was used. The results are shown in Table 9 below.

  Usually, glossiness is classified into light (80% or more), semi-light (40 to 80%), and no light (40% or less) according to the glossiness of the surface. In order to give an effect of preventing glare, it is preferable that the glossiness has a value of 20 to 40%.

  As a result of the experiment, it was confirmed that the advertising paper coated with the coating composition obtained according to the present invention has excellent glossiness (see Table 9).

The schematic diagram which shows one Embodiment of the normal manufacturing process (an extrusion stage, an embossing process stage, a shaping | molding and cooling stage, a drilling stage, a tension adjustment stage, and a cutting stage) of the conventional building exterior material.

Claims (14)

(A) inorganic particles having a hydroxy group having an average particle size of 5 to 30 nm;
(B) inorganic particles having a hydroxy group having an average particle size of 0.2 to 5 μm;
(C) an organosilane represented by the following formula (I);
(D) a solvent;
(E) Self-cleaning coating composition comprising photocatalytic particles:

In the formula, R is an aminoalkyl group having 1 to 8 carbon atoms, a glycidoxyalkyl group or an isocyanate alkyl group, R ′ is a lower alkyl group having 1 to 6 carbon atoms, and n is 0 to 3 It is an integer. The composition according to claim 1, further comprising a hydrolyzate of an alkoxysilane-functionalized aromatic ultraviolet absorber represented by the following formula (II):

In the formula, R ₁ and R ₂ are each independently an alkylene group having 1 to 6 carbon atoms, R ₃ is an alkyl group or aryl group having 1 to 6 carbon atoms, OR ₄ is methoxy, ethoxy, Propoxy, isopropoxy, butoxy or acetoxy, R ₅ is an alkyl or aryl group having 1 to 12 carbon atoms, X is a hydrogen or halogen atom, l is an integer of 5 to 9, and m is It is an integer of 1-3, n is an integer of 0-2.   The composition according to claim 1, wherein the solvent comprises one or more organic solvents having an average boiling point (bp) in the range of 60 to 150 ° C. The composition according to claim 1, wherein the solvent contains an organic solvent having a solubility index (δ) in a plastic of 9.5 Mpa ^0.5 or less. (A) 1-15% by weight of inorganic particles having a hydroxy group with an average particle size of 5-30 nm;
(B) 0.05 to 3% by weight of inorganic particles having a hydroxy group having an average particle size of 0.2 to 5 μm;
(C) 1 to 15% by weight of organosilane,
(D) 50 to 85% by weight of solvent;
(E) 0.1 to 3% by weight of photocatalyst particles;
The composition of claim 1 comprising: (A ) 1 to 10% by weight hydrolyzate of the alkoxysilane functionalized aromatic ultraviolet absorbent according to claim 2 ,
( B ) 0.001-2% by weight of acid,
( C ) 1 to 10% by weight of a thermosetting catalyst;
( D ) 1-10 wt% polyurethane aqueous emulsion,
The composition of claim 5 further comprising: (A) a substrate;
(B) a coating layer formed by coating one side or both sides of the substrate with the composition according to any one of claims 1 to 6;
A self-cleaning substrate comprising:   8. The self of claim 7, wherein the substrate is selected from the group consisting of a film, a building exterior material, a tile, plastic, glass, resin, ceramic, metal, concrete, fiber, wood, paper, and stone. Detergent substrate.   The self-cleaning substrate according to claim 7, wherein the coating layer has a thickness in the range of 0.01 to 50 μm. (A) adding an inorganic particle having an average particle diameter of 5 to 30 nm to one or more dispersion media selected from the group consisting of water, alcohol and ketone to obtain an inorganic particle dispersion;
(B) The inorganic particle dispersion obtained in the step (a) is composed of inorganic particles having an average particle diameter of 0.2 to 5 μm, organosilane represented by the following formula (I), acid, water, alcohol and ketone. Mixing and reacting one or more solvents selected from the group;
(C) adding an organic solvent and photocatalyst particles to the reaction result in step (b);
A method for producing a self-cleaning coating composition comprising:

In the formula, R is an aminoalkyl group having 1 to 8 carbon atoms, a glycidoxyalkyl group or an isocyanate alkyl group, R ′ is a lower alkyl group having 1 to 6 carbon atoms, and n is 0 to 3 It is an integer. The manufacturing method includes:
(I) a step of adding a thermosetting catalyst to the reaction product in step (b) and reacting between the steps (b) and (c);
(Ii) A hydrolyzate of an alkoxysilane functionalized aromatic ultraviolet absorber represented by the following formula (II) is added to the reaction product in the step (b) between the step (b) and the step (c). And reacting,
(Iii) adding a polyurethane aqueous emulsion in step (c);
The manufacturing method according to claim 10, further comprising at least one step selected from the group consisting of:

In the formula, R ₁ and R ₂ are each independently an alkylene group having 1 to 6 carbon atoms, R ₃ is an alkyl group or aryl group having 1 to 6 carbon atoms, OR ₄ is methoxy, ethoxy, Propoxy, isopropoxy, butoxy or acetoxy, R ₅ is an alkyl or aryl group having 1 to 12 carbon atoms, X is a hydrogen or halogen atom, l is an integer of 5 to 9, and m is It is an integer of 1-3, n is an integer of 0-2. (A) coating one side or both sides of the building exterior material before passing through the cooling step with the composition according to any one of claims 1 to 6 to give the building exterior material a self-cleaning property;
(B) cooling or cutting the building exterior material coated in step (a);
A method for manufacturing a building exterior material including:   The manufacturing method according to claim 12, wherein the building exterior material is a plastic substrate that has undergone at least one stage selected from the group consisting of an extrusion stage, a relief processing stage, and a molding stage.   The manufacturing method according to claim 12, wherein the surface temperature of the building exterior material in the step (a) is 100 to 250 ° C.

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