JP2005305327A - Method for forming heat-shielding coating film on inorganic base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a coating film, which has excellent performance such as waterproofness, an antiblocking property, weather resistance, efflorescence resistance and a frost damage preventing property, excellent finished external appearance and a high heat-shielding property, on an inorganic base material by water paint, and to provide a coated body obtained by this method. <P>SOLUTION: This method for forming the heat-shielding coating film on the inorganic base material comprises a step (1) of applying inorganic water paint (I) containing titanium dioxide particles (A) having 400-2,000 nm average primary particle size and a silicone resin emulsion to the surface of the inorganic base material and drying the applied inorganic water paint (I) and a step (2) of applying inorganic water paint (II) containing titanium dioxide particles (B) having <400 nm average primary particle size and the silicone resin emulsion onto the paint (I)-dried coating film obtained at the step (1) and drying the applied inorganic water paint (II). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for forming a thermal barrier coating film on an inorganic substrate and a coated body in which a thermal barrier coating film is formed on an inorganic substrate by the method.

  As a building outer wall material, an inorganic base material mainly composed of an inorganic material such as a cement-based material, a calcium silicate-based material, or a gypsum-based material is widely used.

  In general, the surface of such an inorganic base material is cured to a hydrolyzable silyl group-containing polymer for the purpose of providing performance such as waterproofness, blocking resistance, weather resistance, efflorescence resistance, weather resistance, and frost resistance. An organic solvent-based paint blended with a catalyst is applied. However, in consideration of recent environmental problems, there is a demand for a non-polluting and non-hazardous inorganic base water-based coating method.

  However, when an aqueous paint containing a silicon resin emulsion is used as one coat on an inorganic substrate, there is a problem that it is difficult to form a coating film that satisfies the above performance.

  In response to the above problems, an aqueous silicone resin emulsion paint is used as two coats of an undercoat paint and a topcoat paint, and the silicon component content is increased in the topcoat paint than the undercoat paint. A method for forming a composite coating film suitable for an inorganic substrate that satisfies the required coating film performance, has an excellent finished appearance, is non-polluting, and has no danger of fire or the like is disclosed (Patent Documents 1 and 2). reference).

On the other hand, since inorganic base materials generally have high heat storage properties, heat is stored in structures using inorganic base materials by sunlight irradiation during the day. Due to the heat generated, the outside air temperature may be difficult to decrease. In order to solve this phenomenon, development of a coating film forming method capable of forming a highly heat-shielding coating film on an inorganic substrate is desired.
JP 2000-157828 A JP 2000-136322 A

  An object of the present invention is to provide a water-based paint on an inorganic base material with a coating film having excellent performance such as waterproofness, blocking resistance, weather resistance, efflorescence resistance, frost damage resistance, and finished appearance, and having a high thermal barrier property. It is in providing the method which can be formed by this, and the coating body obtained by this method.

  The inventor has intensively studied to achieve the above object. As a result, an undercoating film is formed on the inorganic base material by an aqueous silicon resin emulsion paint containing titanium dioxide having a relatively large specific average particle diameter, and further, a dioxide having a smaller specific average particle diameter. It has been found that the above-mentioned object can be achieved by forming a top coat film with an aqueous silicone resin emulsion paint containing titanium, and the present invention has been completed based on this.

  The present invention provides a method for forming a heat-shielding coating film on an inorganic substrate and a coated body obtained by the method described below.

1. (1) A water-based inorganic paint (I) containing titanium dioxide (A) having an average primary particle size in the range of 400 to 2,000 nm and a silicon-based resin emulsion is applied to the surface of the inorganic base material and dried. And (2) an aqueous inorganic material containing titanium dioxide (B) having an average primary particle size of less than 400 nm and a silicon-based resin emulsion on the dried coating film of the paint (I) obtained in step (1). Coating and drying the paint (II),
A method for forming a heat-shielding coating film on an inorganic base material, comprising:

  2. Item 2. The method for forming a thermal barrier coating film on an inorganic substrate according to Item 1, wherein the surface of the inorganic substrate is coated with a sealer and dried.

  3. Item 2. The method for forming a thermal barrier coating film on an inorganic substrate according to Item 1, wherein the refractive indexes of titanium dioxide (A) and (B) are 1.80 to 3.00.

  4). Item 2. The method for forming a thermal barrier coating film on an inorganic substrate according to Item 1, wherein the aqueous inorganic coating material (I) further contains hollow fine particles (C).

  5). The coating body in which the heat-shielding coating film is formed on the inorganic base material by the method of said claim | item 1.

6). (1) A water-based inorganic paint (I) containing titanium dioxide (A) having an average primary particle size in the range of 400 to 2,000 nm and a silicon-based resin emulsion is applied to the surface of the inorganic base material and dried. Process,
(2) On the dried coating film of the paint (I) obtained in step (1), a step of further applying an aqueous inorganic paint (I) and drying, and (3) obtained in step (2) Applying a water-based inorganic coating material (II) containing titanium dioxide (B) having an average primary particle size of less than 400 nm and a silicon-based resin emulsion on the dried coating film of the coating material (I), and drying the coating layer;
A method for forming a heat-shielding coating film on an inorganic base material, comprising:

  7). Item 7. The method for forming a thermal barrier coating film on an inorganic substrate according to Item 6, wherein the surface of the inorganic substrate is coated with a sealer and dried.

  8). Item 7. The method for forming a thermal barrier coating film on an inorganic substrate according to Item 6, wherein the refractive indexes of titanium dioxide (A) and (B) are 1.80 to 3.00.

  9. Item 7. The method for forming a thermal barrier coating film on an inorganic substrate according to Item 6, wherein the aqueous inorganic coating material (I) further contains hollow fine particles (C).

  10. The coating body by which the heat-shielding coating film is formed on the inorganic base material by the method of said claim | item 6.

  According to the coating film forming method of the present invention, an undercoat paint that is an aqueous silicone resin emulsion paint containing titanium dioxide having a specific large average particle diameter is applied onto an inorganic substrate, and further, specific small average particles are applied. By applying a top coating that is an aqueous silicone resin emulsion coating containing titanium dioxide having a diameter to form a multilayer coating film, the following remarkable effects can be obtained.

  (1) The multilayer coating film formed from two types of water-based silicone resin emulsion paints is excellent in performance such as waterproofness, blocking resistance, weather resistance, efflorescence resistance, and frost damage resistance.

  (2) Based on the fact that titanium dioxide having a specific large average particle size contained in the undercoat coating film has an infrared ray blocking action, it is possible to impart excellent heat shielding properties to an inorganic base material having high heat storage properties. .

  (3) Based on the fact that titanium dioxide having a specific small average particle size contained in the top coat film has a visible light scattering action, it forms a multi-layer coat film with excellent finish concealment and glossy finish appearance. be able to.

Method for forming a thermal barrier coating film on an inorganic substrate The method for forming a thermal barrier coating film on an inorganic substrate of the present invention is as follows.
(1) A step of applying a water-based inorganic paint (I) on the surface of an inorganic substrate and drying; and (2) a water-based inorganic coating on the dried coating film of the paint (I) obtained in step (1). A method of forming a thermal barrier coating film I on an inorganic base material, comprising the steps of: coating and drying an organic paint (II); and (1) applying an aqueous inorganic paint (I) to the surface of the inorganic base material. A step of coating and drying, (2) a step of further applying a water-based inorganic coating material (I) on the dried coating film of the coating material (I) obtained in step (1) and drying, and (3) A step of applying a water-based inorganic paint (II) onto the dried paint film of the paint (I) obtained in the step (2), and drying the coating; This relates to the formation method II.

  The thermal barrier coating film formation method II of the inorganic base material described above is a method in which the aqueous inorganic coating material (I) is applied twice in the coating film formation method I, and thereby the thermal barrier property is remarkably improved. Therefore, this is a preferred embodiment.

Inorganic base material Examples of the inorganic base material to which the method of the present invention can be applied include an inorganic porous base material produced mainly from an inorganic material such as a cement-based material, a calcium silicate-based material, and a gypsum-based material. it can.

  Examples of the inorganic porous substrate include calcium silicate board, asbestos cement board, wood chip cement board, pulp cement board, lightweight cellular concrete board, and the like.

  In addition, the shape of the inorganic base material may be any shape such as a tile shape, a plate shape, a block shape, and a pipe shape. Moreover, shapes, such as unevenness | corrugation, may be formed in the base-material surface of these shapes.

  The inorganic base material may or may not be subjected to curing such as autoclave curing. The inorganic base material may be subjected to a sealer treatment. The sealer treatment can be easily performed by coating and drying the sealer on an inorganic substrate. The sealer may be applied either before or after curing the inorganic base material.

  In the method of the present invention, the inorganic base material is preferably treated with a sealer from the viewpoint of the adhesion of the aqueous inorganic coating material (I). The sealer is preferably used as a post-curing sealer that is applied after curing of the inorganic base material.

  Specific examples of the sealer include, for example, acrylic resins, vinyl resins, epoxy resins, natural rubber resins, synthetic rubber resins, silicon resins, fluorine resins, polyester resins, and modified resins thereof. A resin obtained by dissolving or dispersing a resin such as an organic solvent or water can be used. Of these resins, epoxy resins can be used preferably.

The coating amount of the sealer (in terms of solid content) is usually, 1~150g / m ² approximately, preferably in the range of about 5~75g / m ^2. When the coating amount is less than 1 g / m ^2, the adhesion of the aqueous inorganic coating material (I) is lowered, whereas when it exceeds 150 g / m ² , cracking may occur in the finally obtained multilayer coating film.

  The sealer can be applied by a conventionally known coating method, for example, a roller, a brush, a spray, a dipping, a flow coater, a curtain flow coater or the like without any particular limitation.

  The sealer can be dried by room temperature drying or heat drying. Heat drying can be performed using, for example, a normal drying furnace, a hot air drying furnace, a jet heater, or the like. The drying conditions are usually an atmospheric temperature of about 250 ° C. or less, preferably about 10 ° C. to 200 ° C., and about 30 seconds to 48 hours, preferably about 1 minute to 24 hours.

Water-based inorganic paint (I)
The aqueous inorganic coating material (I) used in the method of the present invention contains titanium dioxide (A) and a silicon-based resin emulsion having an average primary particle size in the range of about 400 to 2,000 nm as essential components.

  Titanium dioxide (A) is a white pigment blended in the water-based inorganic paint (I) to impart heat shielding properties to the formed coating film, and has an average primary particle size in the range of about 400 to 2,000 nm. It is necessary. If the average primary particle diameter is less than 400 nm, visible light that has passed through the upper layer can be efficiently scattered, but it will transmit infrared rays, resulting in insufficient heat-shielding properties of the formed coating film, whereas if it exceeds 2,000 nm, This is not preferable because the underlying concealability of the finally obtained multilayer coating film is lowered. The average particle diameter is preferably in the range of about 450 to 1,600 nm, and more preferably in the range of about 500 to 1,400 nm.

  Here, the average primary particle diameter is an average value of the particle diameters of the individual independent pigment particles. In general, pigment particles are present in an aggregated state, so it is difficult to distinguish and measure individual and independent particles with an ordinary particle size distribution measuring device. It is possible to determine the average particle size of the independent pigment particles themselves.

  In the present invention, the “average primary particle diameter” is measured with an electron microscope. A commercially available product can be used as an electron microscope for measurement. As a commercial item, the brand name "LUZEX AP" by Nireco Corporation can be mentioned, for example.

  In addition, in order for the undercoat film made of the water-based inorganic coating material (I) to exhibit heat shielding properties, the refractive index of titanium dioxide (A) is about 1.80 to 3.00, preferably 1.90 to 2. It is desirable to be within the range of about 80, more preferably about 1.95 to 2.70.

  In this specification, “refractive index” is a value measured by an Abbe refractometer described in JIS K0062.

  The crystal system of titanium dioxide (A) may be a rutile type or an anatase type. Further, the surface of titanium dioxide may be coated with an inorganic oxide such as aluminum oxide, zirconium oxide or silicon dioxide, or may be treated with an organic compound such as amine or alcohol.

  The blending amount of the titanium dioxide (A) is usually preferably about 20 to 500 parts by weight with respect to 100 parts by weight of the resin solid content of the silicon-based resin emulsion of the aqueous inorganic paint (I). More preferably, it is about 300 parts by weight.

  The aqueous inorganic paint (I) contains a silicon resin emulsion as a resin component. Here, the silicone resin is preferably a resin obtained by copolymerizing a vinyl silicone monomer (a) and another vinyl monomer (b).

  As a silicone resin emulsion, a conventionally known aqueous vinyl silicone resin emulsion can be used without any particular limitation. For example, an aqueous emulsion of a resin having a vinyl silicone monomer (a) and another vinyl monomer (b) as a copolymerization component can be mentioned.

  Examples of the vinyl silicone monomer (a) include vinyl isopropoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, and 2-styrylethyl. Hydroxysilane groups such as trimethoxysilane, vinyltrichlorosilane, γ- (meth) acryloyloxypropyltriacetoxysilane, γ- (meth) acryloyloxypropyltrihydroxysilane, γ- (meth) acryloyloxypropylmethylhydroxysilane, and / or Or the vinyl-type monomer containing a hydrolysable silane group is mentioned. These monomers can be used alone or in combination of two or more.

  The copolymerization amount of the vinyl-based silicon monomer (a) is preferably about 1 to 40% by weight, more preferably about 5 to 30% by weight, based on all monomers.

Other vinyl monomers (b) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, 2-ethylhexyl carbitol Alkyl or cycloalkyl (meth) acrylate of (meth) acrylic acid such as (meth) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Acrylate, 3-hydroxypropyl (meth) acrylate, C ₂ -C ₈ hydroxyalkyl (meth) acrylate acrylic acid or methacrylic acid such as hydroxybutyl (meth) acrylate, polyethylene glycol, polypropylene glycol, polyether such as polybutylene glycol Hydroxyl group-containing vinyl monomers such as monoesters of polyols with unsaturated carboxylic acids such as (meth) acrylic acid; carboxyl group-containing vinyl monomers such as (meth) acrylic acid, maleic anhydride, fumaric acid, itaconic acid; styrene, α -Aromatic vinyl monomers such as methylstyrene and vinyltoluene. These monomers can be used alone or in combination of two or more.

  As the silicone resin emulsion, it is desirable to use a cycloalkyl group-containing (meth) acrylate as a copolymer component from the viewpoint of improving the water resistance and weather resistance of the formed coating film. The cycloalkyl group-containing (meth) acrylate is preferably used in an amount of about 1 to 60% by weight, more preferably about 10 to 35% by weight, based on all monomers.

  The aqueous silicone resin emulsion can be prepared by a conventionally known method. For example, it can be prepared by a method in which a monomer component composed of a vinyl silicone monomer (a) and another vinyl monomer (b) is radically polymerized in the presence of an organic solvent, and the resulting copolymer is made aqueous. In this method, when the obtained copolymer contains a carboxyl group, it is preferably neutralized and then made aqueous.

  Moreover, an aqueous vinyl silicone resin emulsion can be prepared by copolymerizing the monomer component which consists of a vinyl silicone monomer (a) and another vinyl monomer (b) by an emulsion polymerization method. At this time, a core-shell type resin can be obtained by performing emulsion polymerization in multiple stages.

  In addition, the average particle size of the aqueous silicone resin emulsion is preferably about 10 to 1,000 nm from the viewpoint of improving the storage stability of the paint and the underlying hiding property of the finally obtained multilayer coating film. More preferably, it is about 100 to 300 nm.

  In this specification, the average particle diameter of the silicon-based resin emulsion is measured by a particle size distribution measuring machine. A commercially available product can be used as the particle size distribution analyzer. As a commercial item, the brand name "Nanosizer N-4" by a Coulter company can be mentioned, for example.

  In addition, the aqueous inorganic coating material (I) preferably contains hollow fine particles (C) in order to improve the heat shielding property of the formed coating film. The hollow fine particles are fine particles having voids in the particles, and the voids directly become bubbles in the coating film, thereby contributing to an improvement in heat shielding properties. One or two or more voids in the hollow fine particles are contained in the particles, and the void volume in the particles is suitably about 80 to 99.5% by volume. The hollow fine particles may be inorganic material-based fine particles or organic resin-based fine particles.

  Examples of the material of the inorganic material-based fine particles include glass, ceramic, silica, and the like. The organic resin fine particles may be made of polyolefin such as polyethylene or polypropylene; acrylic resin such as polyacrylonitrile or polymethyl methacrylate; fluorine resin such as polyvinylidene fluoride or polytetrafluoroethylene; nylon 11, nylon 12 or the like. Polyamide resin; Polyvinyl chloride resin; Polyvinylidene chloride resin; Amino resin such as benzoguanamine resin and melamine resin; Polyurethane resin; Phenol resin; Silicon resin; Polyester resin; Epoxy resin;

  A commercially available product can be used as the hollow fine particles (C). Specific examples of commercially available products include inorganic material-based hollow glass beads and hollow celite, for example, trade names “Filite 200/7”, “Filite 300/7” manufactured by Nippon Ferrite Co., Ltd., and “Fuji Silysia Chemical”. Balloon S-35, Fuji Balloon S-40, Fuji Balloon S-45, Fuji Balloon H-30, Fuji Balloon H-35, Fuji Balloon H-40X, manufactured by Toshiba Ballotini Product name “Q-Ce1570” and the like. Examples of the organic resin-based hollow fine particles include trade name “ADVANCEL EM EFS001W” (polyacrylonitrile, average particle diameter of 100 μm, void volume of 97 to 98% by volume) manufactured by Sekisui Chemical Co., Ltd. Trade name “Gantz Pearl GMH-850” (polymethacrylic acid resin, average particle diameter of about 8 μm, inner pore diameter of about 6 μm), trade name “SX866 (A)” manufactured by JSR (styrene-acrylic resin, average particle) For example, a diameter of about 0.3 μm and an inner diameter of about 0.2 μm).

  In the method of the present invention, it is preferable to use organic resin fine particles as the hollow fine particles (C) from the viewpoint of excellent heat shielding effect. In addition, organic resin fine particles and inorganic material fine particles may be used in appropriate combination.

  The surface of the hollow fine particles (C) may be appropriately coated with an organic substance, an inorganic substance, a pigment, or the like for the purpose of dispersibility in the paint, improvement of the concealing property of the resulting multilayer coating film, and coloring. Good.

  The shape of the hollow fine particles (C) may be any shape such as a sphere and a flat sphere.

  The average particle size of the hollow fine particles (C) is preferably about 0.1 to 1,000 μm, more preferably about 10 to 200 μm, and further preferably about 10 to 150 μm. Here, when the shape of the hollow fine particles is other than spherical, the average particle diameter means a long average particle diameter. When the average particle diameter is less than 10 μm, the heat shielding effect is lowered, while when it exceeds 1,000 μm, it may be difficult to paint. In the method of the present invention, two or more kinds of hollow fine particles having different average particle diameters can be used in combination.

  In the method of the present invention, the amount of the hollow fine particles (C) blended is 100% by weight of the resin solid content of the silicon-based resin emulsion of the aqueous inorganic coating material (I) from the viewpoint of the flexibility and heat shielding properties of the formed coating film. Usually, the amount is preferably about 5 to 300 parts by weight, more preferably about 15 to 125 parts by weight.

  The water-based inorganic paint (I) comprises a silicon-based resin emulsion and titanium dioxide (A) as essential components, and is blended with hollow fine particles (C) as necessary. Further, if necessary, a filler, Curing catalysts, fluidity modifiers, antifoaming agents, antifreezing agents, organic solvents, film-forming aids, colored pigments other than titanium dioxide (A) and (B), extender pigments, and the like can be blended.

  The solid content concentration of the water-based inorganic paint (I) is preferably about 10 to 80% by weight from the viewpoint of ensuring the coating film thickness and improving the permeability to the inorganic base material. More preferably, it is about wt%.

The coating amount of the aqueous inorganic coating (I) (in terms of solid content) ^{is, 5g / m 2 ~1,600g / m} 2 , preferably about suitably within the range of about 20g / m ² ~1,200g / m ² is there. As a coating means, a conventionally known coating method such as a roller, a brush, a spray, a dipping, a flow coater, a curtain flow coater or the like can be adopted without any particular limitation.

  The aqueous inorganic coating material (I) can be dried by room temperature drying or heat drying. Heat drying can be performed using, for example, a normal drying furnace, a hot air drying furnace, a jet heater, or the like. The drying conditions are usually an atmospheric temperature of about 200 ° C. or less, preferably about 10 ° C. to 150 ° C., about 10 seconds to 300 minutes, preferably about 20 seconds to 180 minutes.

  In the thermal barrier coating film forming method I of the inorganic base material of the present invention, the aqueous inorganic coating material (I) is coated and dried once on the inorganic base material under the above conditions. In addition, in the thermal barrier coating film forming method II of the inorganic base material, the aqueous inorganic coating material (I) is applied twice on the inorganic base material. In this case, the first and second coating and drying conditions are applied. Both can be performed within the above conditions.

Water-based inorganic paint (II)
The aqueous inorganic paint (II) used in the method of the present invention contains titanium dioxide (B) having an average primary particle size of less than 400 nm and a silicon resin emulsion as essential components.

  Titanium dioxide (B) contained in the aqueous inorganic coating material (II) is a white pigment having an average primary particle size of less than about 400 nm. The average primary particle diameter of titanium dioxide (B) is preferably in the range of about 100 to 300 nm.

  In the method of the present invention, by providing a coating film of the water-based inorganic paint (II) on the coating surface of the water-based inorganic paint (I), it is possible to improve the base concealing property, gloss, etc. while maintaining the heat shielding property. Therefore, a multilayer coating film having an excellent finished appearance can be formed.

  Moreover, the refractive index of titanium dioxide (B) is about 1.80 to 3.00, preferably 1 from the point that the top coating film made of the water-based inorganic coating material (II) contributes to the heat shielding property of the multilayer coating film. It is desirable that it is in the range of about .90 to 2.80, more preferably about 1.95 to 2.70.

  The crystal system of titanium dioxide (B) may be a rutile type or an anatase type, but rutile is superior in terms of the underlying concealing property, weather resistance, etc. of the coating film formed by the paint (II). A mold is preferred. Further, the surface of titanium dioxide may be coated with an inorganic oxide such as aluminum oxide, zirconium oxide or silicon dioxide, or may be treated with an organic compound such as amine or alcohol.

  The blending amount of titanium dioxide (B) is 100 parts by weight of the resin solid content of the silicon-based resin emulsion of the aqueous inorganic paint (II) from the viewpoint of improving the finished appearance of the finally obtained multilayer coating film. On the other hand, it is usually preferably about 10 to 400 parts by weight, more preferably about 20 to 200 parts by weight.

  In the water-based inorganic paint (II), a silicon resin emulsion is used as a resin component from the viewpoint of improving the adhesion to the paint film by the water-based inorganic paint (I) and the weather resistance of the multilayer paint film. It is characterized by. As the silicon-based resin emulsion, conventionally known ones can be used without limitation, but those similar to those described in the section of the water-based inorganic paint (I) can be used.

  The water-based inorganic paint (II) has a silicone resin emulsion and titanium dioxide (B) as essential components, and if necessary, a filler, a curing catalyst, a fluidity modifier, an antifoaming agent, an antifreezing agent, an organic Solvents, film-forming aids, coloring pigments other than titanium dioxide (A) and (B), extender pigments, antifungal agents, algaeproofing agents, antibacterial agents, antifouling agents, and the like can be blended.

  The solid content concentration of the water-based inorganic paint (II) is preferably about 10 to 80% by weight from the viewpoint of ensuring the coating film thickness and improving the finished appearance and weather resistance. More preferably, it is about wt%.

The coating amount of the aqueous inorganic coating (II) (in terms of solid content) ^{is, 5g / m 2 ~240g / m} 2 approximately, preferably suitably in the range of about ^{20g / m 2 ~180g / m 2} . As a coating means, a conventionally known coating method such as a roller, a brush, a spray, a dipping, a flow coater, a curtain flow coater or the like can be adopted without any particular limitation.

  The aqueous inorganic coating material (II) can be dried by room temperature drying or heat drying. Heat drying can be performed using, for example, a normal drying furnace, a hot air drying furnace, a jet heater, or the like. The drying conditions are usually an atmospheric temperature of about 200 ° C. or less, preferably about 10 ° C. to 150 ° C., about 10 seconds to 300 minutes, preferably about 20 seconds to 180 minutes.

  Thus, by the method for forming a thermal barrier coating film of an inorganic base material of the present invention, the inorganic base material is excellent in performance such as waterproofness, blocking resistance, weather resistance, efflorescence resistance, frost resistance, and finished appearance. A coating film that is excellent and has a high thermal barrier property can be formed.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples and comparative examples. In each example, “%” and “part” are in principle based on weight.

Production Example 1 Production of Silicone Resin Emulsion 50 parts of deionized water and 0.05 part of sodium dodecylbenzenesulfonate in a reaction vessel with a capacity of 2 liters equipped with a thermometer, thermostat, stirrer, reflux condenser, and dropping device. The temperature was raised to 82 ° C. In this reaction container, the following monomer emulsion (1) was dripped over 3 hours. After completion of dropping of the monomer emulsion (1), the following monomer emulsion (2) was dropped therein over 1 hour, after aging at 82 ° C. for 2 hours, and then cooled to 40 ° C. A shell-type copolymer emulsion was obtained. The obtained copolymer emulsion had a solid content of 40% and an average particle size of 120 nm.

  Monomer emulsion (1): 38 parts of deionized water, 3 parts of sodium dodecylbenzenesulfonate and 0.15 part of ammonium peroxosulfate as a polymerization initiator were added to a flask having a capacity of 4 liters. A monomer mixture consisting of 20 parts of cyclohexyl methacrylate, 10 parts of methyl methacrylate, 22.6 parts of n-butyl acrylate, 9 parts of n-butyl methacrylate, 7.7 parts of vinyltrimethoxysilane and 0.7 parts of methacrylic acid was added and stirred. As a result, a monomer emulsion (1) was obtained.

  Monomer emulsion (2): In a 4 liter flask, 16 parts of deionized water, 1.5 parts of sodium dodecylbenzenesulfonate and 0.05 parts of ammonium peroxosulfate were added, and after stirring well, cyclohexyl was added. A monomer mixture consisting of 15 parts of methacrylate, 10 parts of methyl methacrylate, 2 parts of n-butyl acrylate, 2.4 parts of n-butyl methacrylate, 0.3 part of vinyltrimethoxysilane and 0.3 part of methacrylic acid was added and stirred. Monomer emulsion (2) was obtained.

Production Examples 2 to 8 Manufacture of water-based inorganic paints Water-based inorganic paints (I-1) to (I-6) and water-based inorganic paint (II-1) were produced with the composition shown in Table 1 below.

表１における配合量は、重量部を意味する。また、表中、（注１）〜（注９）は、次のものを、示す。

The compounding amount in Table 1 means parts by weight. In the table, (Note 1) to (Note 9) indicate the following.

  (Note 1) Antifreezing agent: monoethylene glycol, manufactured by Mitsui Chemicals, Inc.

  (Note 2) Neutralizing agent: 25% ammonia water, manufactured by Daisoh Kako Co., Ltd.

  (Note 3) Styrene acrylic resin-based dispersant: trade name “34% John Crill 60”, manufactured by Johnson Polymer Co., Ltd.

  (Note 4) Titanium dioxide (A): trade name “JR-1000”, manufactured by Teika Co., Ltd., average primary particle size 1,000 nm, refractive index 2.72.

  (Note 5) Titanium dioxide (B): trade name “JR-605”, manufactured by Teika Co., Ltd., average primary particle size 250 nm, refractive index 2.72.

  (Note 6) Hollow fine particles: Trade name “Advancel EM EFS001W”, manufactured by Sekisui Chemical Co., Ltd., polyacrylonitrile, average particle size 100 μm, void volume 97-98 vol%.

  (Note 7) Film-forming auxiliary: trade name “CS12”, manufactured by Chisso Corporation, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

  (Note 8) Antifoaming agent: trade name “BYK024”, manufactured by BYK.

  (Note 9) Thickener: Trade name “DK thickener SCT275” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

Examples 1-10 and Comparative Examples 1-5
(1) The following inorganic base materials (i) and (ii) were prepared as test materials.

  Inorganic base material (i): Portland cement 60 parts, silica sand 50 parts, pulp fiber 5 parts, sepiolite 3 parts, carbon black 1 part and water 120 parts are made into a plate by a papermaking method and then press-molded An inorganic base material obtained by

  Inorganic base material (ii): An inorganic base material obtained by curing the above-mentioned inorganic base material (i) in an autoclave at 170 ° C. for 4 hours.

(2) On the inorganic base materials (i) and (ii), the respective water-based inorganic paints (I-1) to (I-6) obtained in Production Examples 2 to 8 in the combinations shown in Table 2 below. And (II-1) was each coated on the conditions of postscript Table 2, and each test coating plate was created. The coating amount (in terms of solid content) was 75 g / m ² / time, and the drying conditions were each dried at 25 ° C. for 120 minutes for each coating to prepare each test coated plate.

In addition, the sealer process as the base treatment of the inorganic base material is performed by applying an epoxy resin sealer (trade name “multi-tile concrete primer EPO”, manufactured by Kansai Paint Co., Ltd.) on the inorganic base material in a solid content. The coating was performed by a roller so as to be 60 g / m ² , and drying was performed at 25 ° C. for 16 hours.

Performance Test Each of the test coated plates obtained above was subjected to performance tests for adhesion, base concealing property, thermal cooling cycle, frost damage resistance, weather resistance, and heat shielding temperature. The test method is as follows.

Adhesiveness: A cross cut with an acute angle of 30 degrees was put on each test coating plate with a cutter knife, and an adhesive tape was applied and peeled off. The adhesiveness was evaluated according to the following criteria.
○: No peeled coating and good adhesion, Δ: Less than 30% of the coating peeled between the coated surface and the water-based inorganic paint (I), slightly poor adhesion, ×: coated surface And 30% or more of the coating film peeled between the aqueous inorganic paint (I) and poor adhesion.

Base concealing property: The base concealing property of each test coating plate was visually evaluated according to the following criteria.
○: The base is completely hidden, Δ: The base is slightly transparent, ×: The base is transparent.

Heating / cooling cycle: Each test coated plate was cooled at −20 ° C. for 4 hours, then dried at 60 ° C. for 4 hours, and then dried at 40 ° C. for 4 hours. The state was visually observed and evaluated according to the following criteria.
○: No change is observed in the coating film after 100 cycles, Δ: Cracking or peeling is observed in less than 50 cycles, ×: Cracking or peeling is observed in less than 10 cycles.

Freezing damage resistance: Each test coated plate was cooled at -18 ° C for 3 hours, and then immersed in water at 5 ° C for 1 hour. One cycle was repeated for 300 cycles, and the state of the coating film was visually observed. Evaluation was made according to the following criteria.
○: No change is observed in the coating film, ◇: Fine cracks of 1 mm or less are observed in a part of the coating plate, Δ: Cracking and peeling are observed in a part of the coating plate, ×: Cracking and peeling in the entire coating plate Is seen.

Weather resistance test: Each test coated plate was subjected to an accelerated weather resistance test for 1,000 hours using a sunshine carbon arc lamp type tester according to JIS K5400 9.8.1. The gloss of the coating film at that time was visually observed and evaluated according to the following criteria in comparison with the initial coated surface where the accelerated weather resistance test was not conducted.
○: There is almost no change in gloss, Δ: gloss is slightly lowered, and X: gloss is remarkably lowered.

  Thermal insulation temperature: When each test coating plate is irradiated with a halogen lamp (100V, 300W) from the side where each water-based inorganic paint is applied at a distance of 30 to 50 cm, the temperature difference between the front and back surfaces of the test coating plate is traced, and the value converges The temperature difference (° C.) was defined as the heat shielding temperature. The larger the value, the higher the heat shielding effect.

  Table 2 shows the results of the coating steps of Examples 1 to 10 and Comparative Examples 1 to 5 and the performance tests of the obtained multilayer coating films. In Table 2, “1 time” in the column of the water-based inorganic paint indicates that the number of times of coating is 1, and “2 times” indicates that the number of times of coating is 2.

Claims (10)

(1) A water-based inorganic paint (I) containing titanium dioxide (A) having an average primary particle size in the range of 400 to 2,000 nm and a silicon-based resin emulsion is applied to the surface of the inorganic base material and dried. And (2) an aqueous inorganic material containing titanium dioxide (B) having an average primary particle size of less than 400 nm and a silicon-based resin emulsion on the dried coating film of the paint (I) obtained in step (1). Coating and drying the paint (II),
A method for forming a heat-shielding coating film on an inorganic base material, comprising: The method for forming a thermal barrier coating film on an inorganic substrate according to claim 1, wherein the surface of the inorganic substrate is coated and dried with a sealer. The method for forming a thermal barrier coating film on an inorganic substrate according to claim 1, wherein the refractive indexes of titanium dioxide (A) and (B) are 1.80 to 3.00. The method for forming a thermal barrier coating film on an inorganic substrate according to claim 1, wherein the aqueous inorganic coating material (I) further contains hollow fine particles (C). The coating body by which a heat-shielding coating film is formed on the inorganic base material by the method of Claim 1. (1) A water-based inorganic paint (I) containing titanium dioxide (A) having an average primary particle size in the range of 400 to 2,000 nm and a silicon-based resin emulsion is applied to the surface of the inorganic base material and dried. Process,
(2) On the dried coating film of the paint (I) obtained in step (1), a step of further applying an aqueous inorganic paint (I) and drying, and (3) obtained in step (2) Applying a water-based inorganic coating material (II) containing titanium dioxide (B) having an average primary particle size of less than 400 nm and a silicon-based resin emulsion on the dried coating film of the coating material (I), and drying the coating layer;
A method for forming a heat-shielding coating film on an inorganic base material, comprising: The method for forming a thermal barrier coating film on an inorganic substrate according to claim 6, wherein the surface of the inorganic substrate is coated and dried with a sealer. The method for forming a thermal barrier coating film on an inorganic substrate according to claim 6, wherein the refractive indexes of titanium dioxide (A) and (B) are 1.80 to 3.00. The method for forming a thermal barrier coating film on an inorganic substrate according to claim 6, wherein the aqueous inorganic coating material (I) further contains hollow fine particles (C). The coating body in which the heat-shielding coating film is formed on the inorganic base material by the method of Claim 6.