JP2017185437A - Coat forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coat forming method that gives an appearance with good finishing and prevents defects such as expansion, peeling, and cracking.SOLUTION: A coat forming method is characterized by applying an epoxy-based first coat formation material containing an epoxy resin and an amine curing agent, and a second coat formation material having a specific pigment volume concentration and a specific elongation, in the stated order.SELECTED DRAWING: None

Description

  The present invention relates to a film forming method applicable to a wall surface of a building or a civil engineering structure.

  2. Description of the Related Art Conventionally, concrete, mortar, various plate-like wall materials, or the like having a coating on the surface thereof are used for wall surfaces of buildings, civil engineering structures, and the like.

  When such a wall surface is exposed to the outdoors for a long period of time, its surface deteriorates due to the influence of sunlight, rain, dust, and the like, and the initial aesthetics deteriorate with age. Furthermore, in such a wall surface, the water-imperviousness drop occurs along with the surface deterioration, water easily enters the inside, the deterioration is promoted, and a defect such as a crack may occur.

  Moreover, if the way of sunlight, the flow of rainfall, and the like are different in one wall surface, a difference in the deterioration state is likely to occur. In such a case, the appearance, strength, and the like are not uniform, and various surface deterioration state regions tend to be mixed.

  Japanese Patent Application Laid-Open No. 11-192454 describes a method in which an epoxy-cured acrylic resin-based sealer is applied to an inorganic base material such as a concrete board, and then a specific vinyl resin-based finish is applied. Japanese Patent Application Laid-Open No. 11-286646 discloses a building exterior sealer containing an epoxy resin, a ketimine, a solid resin, a dehydrating agent, and the like.

JP-A-11-192454 Japanese Patent Laid-Open No. 11-286646

  However, even if a film is formed on the deteriorated wall as described above using the technique of the above-mentioned patent document, it is difficult to sufficiently fill the cracks on the surface. However, satisfactory results are difficult to obtain. In some cases, cracks may become apparent due to the application of the finishing material.

  Moreover, in the said patent document, it may be difficult to homogenize the surface state of the wall surface deteriorated unevenly. In that case, there is a possibility that the appearance after the finish material is coated may be uneven, resulting in insufficient finish, or peeling or swelling of the coating due to poor adhesion. Furthermore, if the wall surface to be painted has an existing coating, it may be difficult to ensure sufficient adhesion depending on the type, deterioration state, and the like.

  The present invention has been made in view of the problems as described above, and repairs the surface deterioration of the base material constituting the wall surface of a building, a civil engineering structure, etc., and has an excellent finish. It is an object of the present invention to provide a method for forming a film that can be obtained and can suppress occurrence of problems such as swelling, peeling, and cracking.

  As a result of intensive studies to achieve the above object, the present inventor has conceived a method for applying a specific first film forming material and a second film forming material to a substrate, and completes the present invention. It reached.

That is, the present invention has the following characteristics.
1. It is a film forming method for applying a first film forming material and a second film forming material in order to a base material,
The first film-forming material contains an epoxy resin and an amine curing agent,
The epoxy equivalent of the epoxy resin is 500 g / eq or more and 2000 g / eq or less,
The active hydrogen equivalent of the amine curing agent is 50 g / eq or more and 200 g / eq or less,
The active hydrogen equivalent of the amine curing agent and the epoxy equivalent of the epoxy resin are less than 0.4 in [active hydrogen equivalent of the amine curing agent / epoxy equivalent of the epoxy resin],
The second film forming material forms a film having a pigment volume concentration of 20% or more and 80% or less and an elongation rate in an atmosphere of 20 ° C. of 30% or more and 800% or less. .
2. A third film forming material is further applied on the second film forming material. The method for forming a film according to the above.

  According to the method for forming a film of the present invention, an appearance having excellent finish can be obtained, and occurrence of problems such as swelling, peeling and cracking can be suppressed.

  The present invention relates to a film forming method in which a first film forming material and a second film forming material are sequentially applied to a substrate.

<Base material>
The substrate used in the present invention is not particularly limited as long as it can be applied to buildings, civil engineering structures and the like. For example, concrete, mortar, slate plate, calcium silicate plate, ALC plate, extruded plate, slate tile Cement tile, new roof tile, porcelain tile, siding board, metal, glass, wood, plywood, etc., or those having an old coating film formed thereon.

  As the old coating film, it is applied on the above-mentioned base material. For example, weather-resistant top coating for construction (JISK5658: 2010), weather-resistant coating for steel structures (JISK5659: 2008), glossy synthetic resin emulsion Paint (JISK5660: 2008), fire protection paint for buildings (JISK5661: 1970), synthetic resin emulsion paint (JISK5663: 2008), road marking paint (JISK5665: 2011), multicolored paint (JISK5667: 2003), synthetic resin emulsion pattern Paint (JISK5668: 2010), acrylic resin-based non-water-dispersed paint (JISK5670: 2008), lead / chrome-free anticorrosive paint (JISK5674: 2008), high solar reflectance paint for roofs (JISK5675: 2011), building Use floor paint (JISK5970: 2008), building waterproofing membrane material (JISA6021: 2011), building topcoat material (JISA6909: 2014) coated film and the like formed by the like. In particular, the present invention can be applied to a fluororesin coating film, a silicon resin coating film, and the like.

<First film forming material>
The 1st film formation material used by this invention is apply | coated on the said base material, and contains an epoxy resin and an amine hardening | curing agent.
An epoxy resin having an epoxy equivalent (per solid content) of 500 g / eq or more and 2000 g / eq or less, preferably 600 g / eq or more and 1500 g / eq or less is used.
As the amine curing agent, one having an active hydrogen equivalent (per solid content) of 50 g / eq or more and 200 g / eq or less, preferably 60 g / eq or more and 150 g / eq or less is used.
Further, in the epoxy resin and the amine curing agent, the active hydrogen equivalent of the amine curing agent and the epoxy equivalent of the epoxy resin are less than 0.4, preferably 0.01 in terms of [active hydrogen equivalent of the amine curing agent / epoxy equivalent of the epoxy resin]. More than 0.3 and less, more preferably 0.03 or more and 0.25 or less, and still more preferably 0.05 to 0.2 or less, each material is set and used. is there.

  The epoxy equivalent is a value obtained by dividing the molecular weight of the epoxy resin by the number of epoxy groups. The active hydrogen equivalent is a value obtained by dividing the molecular weight of the amine curing agent by the number of hydrogen atoms in the amino group.

In general, the mixing of the epoxy resin and the amine curing agent is based on the epoxy equivalent of the epoxy resin, and the active hydrogen equivalent of the amine curing agent is often combined with about 0.5 to 2 times the epoxy equivalent, The equivalent ratio is usually set to about 1.
However, in the present invention, a specific epoxy resin having an epoxy equivalent of 500 g / eq or more and 2000 g / eq or less and a specific amine curing agent having an active hydrogen equivalent of 50 g / eq or more and 200 g / eq or less are selected as [active hydrogen of amine curing agent]. Equivalent / Epoxy equivalent of epoxy resin] is selected to be less than 0.4, and by combining these, it exhibits excellent adhesion to a wide range of substrates and the second film forming material described below. This is the first time I found it.
In particular, even if what has high functions such as high durability and antifouling properties, which are frequently employed recently, is an old coating film of a base material or a second film forming material described later, it exhibits excellent adhesion It is something that can be done.
Although the details of such a mechanism are unknown, it is thought to be due to the balance between the molecular weight balance of the epoxy resin and the amine curing agent and the strong cross-linked structure of the epoxy-amine.

When [active hydrogen equivalent of amine curing agent / epoxy equivalent of epoxy resin] is 0.4 or more, it becomes difficult to exhibit excellent adhesion to a wide range of substrates and coating surfaces.
Moreover, when the epoxy equivalent of an epoxy resin and the active hydrogen equivalent of an amine hardening | curing agent are too larger than the said range, or too small, there exists a possibility that it may be inferior to adhesiveness.

  The mixing ratio of the epoxy resin and the amine curing agent is not particularly limited, but [(Amount of amine curing agent / active hydrogen equivalent of amine curing agent) / (Amount of epoxy resin / epoxy equivalent of epoxy resin)] And preferably 0.1 or more and 10 or less, more preferably 0.3 or more and 2 or less, and still more preferably 0.6 or more and 1.2 or less.

The epoxy resin is not particularly limited as long as it satisfies the above conditions. For example, bisphenol type epoxy resin such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, phenol novolac type bisphenol A epoxy resin, and phenol novolac type bisphenol. Phenolic novolac type epoxy resin such as F epoxy resin, cresol novolac type epoxy resin, novolac type epoxy resin such as bisphenol A novolac type epoxy resin, copolymer type epoxy resin of bisphenol A type epoxy resin and phenol novolac resin, dihydroxynaphthalene Of diglycidyl ether, mono (di) hydroxynaphthalene novolac polyglycidyl ether, phenol-divinylbenzene cross-linked phenolic resin Li glycidyl ethers, bisphenol A- divinylbenzene crosslinked phenolic resins polyglycidyl ether, mono (di) hydroxy naphthalene - polyglycidyl ethers of divinylbenzene crosslinked phenolic resins.
In the present invention, in particular, one or more phenol novolac type epoxy resins selected from a phenol novolac type bisphenol A epoxy resin and a phenol novolac type bisphenol F epoxy resin can be suitably used.

The amine curing agent is not particularly limited as long as the above conditions are satisfied. For example, aliphatic polyamine, alicyclic polyamine, aromatic polyamine, heterocyclic amine, aliphatic polyamide, alicyclic polyamide, aromatic polyamide, aliphatic Polyamide amine, alicyclic polyamidoamine, aromatic polyamidoamine and the like can be mentioned.
In the present invention, in particular, one or more aliphatic amine curing agents selected from aliphatic polyamines, aliphatic polyamides, and aliphatic polyamidoamines can be suitably used.

The first film forming material of the present invention preferably contains a silane compound.
As the silane compound, for example,
Tetrafunctional alkoxysilane compounds such as tetraethoxysilane, tetramethoxysilane, tetrabutoxysilane,
Methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltributoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, Trifunctional alkoxysilane compounds such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltributoxysilane,
Dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxy Bifunctional alkoxysilane compounds such as silane, diphenyldibutoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane,
Chlorosilane compounds such as tetrachlorosilane, methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, dimethyldichlorosilane, diethyldichlorosilane, diphenyldichlorosilane, methylphenyldichlorosilane,
Acetoxysilane compounds such as tetraacetoxysilane, methyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane, diphenyldiacetoxysilane,
γ-glycidoxypropyltrimexisilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriisopropenyl Contains epoxy groups such as oxysilane, γ-glycidoxypropyltriiminooxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, adduct of γ-isocyanatopropyltriisopropenyloxysilane and glycidol Silane compounds,
N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, etc. A silane compound containing an amino group of
γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, etc. And silane compounds containing a (meth) acryloxy group.
By including these silane compounds, the adhesion can be further improved.
In the present invention, in particular, one or more selected from a silane compound containing an epoxy group and a silane compound containing an amino group can be suitably used.

The mixing ratio of the silane compound is not particularly limited, but 0.1 parts by weight or more and 30 parts by weight or less (more preferably 0.3 parts by weight or more and 10 parts by weight or less) with respect to 100 parts by weight of the epoxy resin (solid content). It is preferably 5 parts by weight or more and 3 parts by weight or less.
By being in such a range, the adhesiveness can be further improved, and not only when coating immediately after mixing of the epoxy resin and the amine curing agent, but also when mixing after mixing and elapses, it is excellent. Adhesion can be shown.

In addition, the solvent used in the first film forming material of the present invention is not particularly limited. For example, toluene, xylene, n-hexane, n-pentane, n-octane, n-nonane, n-decane, n-undecane. , Hydrocarbon solvents such as n-dodecane, terpin oil, mineral spirits, solvesso,
Ethanol, propanol, butanol, hexanol, octanol, 2-ethyl-1-hexanol, decanol, benzyl alcohol, ethylene glycol mono-2-ethylhexyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, tri Alcohol solvents such as propylene glycol mono-n-butyl ether, propylene glycol mono-2-ethylhexyl ether, propylene glycol monophenyl ether,
Ester solvents such as n-butyl acetate, isobutyl acetate, isoamyl acetate, methyl amyl acetate, ethylene glycol monobutyl ether acetate,
Examples include ketone solvents such as methyl isobutyl ketone, cyclohexanone, ethyl n-amyl ketone, and diisobutyl ketone.

In this invention, it is preferable that a hydrocarbon solvent and an alcohol solvent are included as a solvent. In particular, an alcohol solvent having a solubility parameter (SP value) of 10 to 15 (preferably 12 to 14) is preferably used as the alcohol solvent. By using such a solvent, excellent performance can be exhibited even in a low temperature environment of 10 ° C. or lower. Moreover, it is preferable to use an alcohol solvent having a boiling point of 100 ° C. or higher and 260 ° C. or lower (more preferably 150 ° C. or higher and 230 ° C. or lower), and excellent performance can be exhibited even in a low temperature environment such as 10 ° C. or lower. In particular, better adhesion to the substrate and the coating surface can be exhibited.
As such an alcohol solvent, isopropyl alcohol (SP value 11.5, boiling point 82 ° C.), n-butyl alcohol (SP value 11.4, boiling point 117 ° C.), hexanol (SP value 10.1, boiling point 158 ° C.) Octanol (SP value 10.3, boiling point 195 ° C.), ethyl alcohol (SP value 12.7, boiling point 78 ° C.), benzyl alcohol (SP value 12.1, boiling point 205 ° C.), etc. are preferably used. .

  The solubility parameter (SP value) is a value that serves as an index of solubility. Polymer Handbook Fourth Edition (Polymer Handbook Fourth Edition, written by J. Brand, published by Wiley in 1998) The values described on pages VII-675 to VII-711 were employed.

As the first film-forming material of the present invention, in addition to the above-described components, if necessary, a coloring pigment, an extender pigment, a rust preventive pigment, a plasticizer, an antiseptic, an antifungal agent, an antialgae, an antifoaming agent, and a leveling agent , Pigment dispersants, anti-settling agents, anti-sagging agents, matting agents, catalysts, curing accelerators and the like can be mixed within a range that does not impair the effects of the present invention.
In addition, the first film forming material can be produced by uniformly stirring and mixing the above components by a conventional method. The form of the film-forming material is preferably a two-part form consisting of a main agent containing an epoxy resin and a curing agent containing an amine curing agent during distribution, and these are desirably mixed and used during painting.

<Second film forming material>
The second film forming material used in the present invention is applied onto the surface of the first film forming material, and the pigment volume concentration is 20% to 80%, preferably 30% to 70%, 20 A film having an elongation in the atmosphere of 30 ° C. to 800%, preferably 50% to 600% is formed.
By applying such a second film-forming material, it is possible to follow the base material and the first film-forming material, and to suppress the occurrence of problems such as swelling, peeling, and cracking, and finishing properties. An excellent appearance can be obtained.
When the pigment volume concentration is smaller than 20% or the elongation percentage is larger than 800%, it may be difficult to form and maintain an appearance with excellent finish. Further, when the pigment volume concentration is larger than 80% or the elongation percentage is smaller than 30%, problems such as swelling, peeling and cracking may occur.

  The elongation is a value (elongation at 23 ° C.) measured by the method of “Standard Elongation Test” of JIS A6909 “7.26 Elongation Test”. However, a test piece having a dry film thickness of 0.3 mm is used.

  The second film forming material is not particularly limited as long as it satisfies the above conditions, but a material containing a binder and a pigment is preferable.

Examples of the binder include acrylic resin, urethane resin, vinyl acetate resin, vinyl chloride resin, epoxy resin, urethane resin, silicon resin, fluorine resin, acrylic vinyl acetate resin, acrylic urethane resin, acrylic silicon resin, and the like. These 1 type (s) or 2 or more types can be used.
The glass transition temperature of such a resin component is preferably −50 ° C. or more and 60 ° C. or less, more preferably −40 ° C. or more and 50 ° C. or less. The glass transition temperature is a value determined by the FOX calculation formula.

As such a binder, those having a crosslinkable reactive group are particularly preferable.
As a crosslinkable reactive group, in combination, for example, between alkoxysilyl groups, carboxyl group and carbodiimide group, carboxyl group and epoxy group, carboxyl group and aziridine group, carboxyl group and oxazoline group, hydroxyl group and isocyanate group, carbonyl group Examples include a hydrazino group, an epoxy group and a hydrazino group, an epoxy group and an amino group, and those having a crosslinkable reactive group are preferable, and a combination of an epoxy group and an amino group or a carboxyl group and an epoxy group is particularly preferable.

  Examples of the pigment include titanium oxide, zinc oxide, alumina, carbon black, ferric oxide (valve), yellow iron oxide, iron oxide, ultramarine, cobalt green, and other inorganic color pigments, azo, naphthol, and pyrazolone. , Anthraquinone, perylene, quinacridone, disazo, isoindolinone, benzimidazole, phthalocyanine, quinophthalone, and other organic color pigments, pearl pigments, aluminum pigments, fluorescent pigments, heavy calcium carbonate, Precipitated calcium carbonate, kaolin, talc, clay, porcelain clay, China clay, barium sulfate, barium carbonate, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate, silica powder, aluminum hydroxide, cold water stone, quartz sand , Extender pigments such as quartzite and diatomaceous earth, etc. It can be used one or more.

  In particular, the pigment preferably contains a pigment having an average particle size of 0.1 μm or more and 30 μm or less. By including such a pigment, a more excellent effect can be obtained.

  Also, by including one or more pigments selected from titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, and zirconium oxide as pigments, the effect of suppressing the occurrence of defects on the finished surface works, and the appearance is excellent in finish. It is possible to obtain.

As the second film forming material of the present invention, in addition to the above-described components, if necessary, a plasticizer, an antiseptic, a rust inhibitor, an antifungal agent, an algae inhibitor, an antifoaming agent, a leveling agent, a pigment dispersant, An anti-settling agent, an anti-sagging agent, a matting agent, a catalyst, a curing accelerator and the like can be mixed within a range in which the effects of the present invention are not inhibited.
The second film-forming material can be produced by uniformly stirring and mixing the above components by a conventional method.

<Film formation method>
The film forming method of the present invention is characterized in that a first film forming material and a second film forming material are sequentially applied to a substrate.

As a method for applying the first film forming material, for example, it can be applied using a known coating instrument such as a brush, a roller, or a spray. Moreover, when painting at a factory etc., it can also paint using a roll coater, a flow coater, etc.
Coating with the amount of the first coating formation material is preferably 0.05 kg / ^{m 2} or more 0.5 kg / ^{m 2} or less, more preferably 0.07 kg / ^{m 2} or more 0.3 kg / ^{m 2} or less.
Moreover, what is necessary is just to set the frequency | count of coating suitably by the surface state etc. of a base material, However, Preferably it is 1-2 times. The first film forming material of the present invention can form a coating film having excellent sealing properties even with such a small number of coatings.
The drying time is preferably 1 hour or more and 1 week or less. The drying temperature is preferably −10 ° C. or more and 50 ° C. or less, more preferably −5 ° C. or more and 40 ° C. or less. In the present invention, excellent performance can be exhibited even in a low temperature environment of 10 ° C. or less.

As a method for applying the second film forming material, for example, the coating can be performed using a known coating tool such as a brush, a trowel, a roller, or a spray. Moreover, when painting at a factory etc., it can also paint using a roll coater, a flow coater, etc.
Moreover, although it can coat irrespective of the hardening state of a 1st film formation material, it is preferable to apply after hardening.
The application amount of the second film forming material is preferably 0.1 kg / m ² or more and 1 kg / m ² or less, more preferably 0.15 kg / m ² or more and 0.5 kg / m ² or less. It can also be diluted appropriately with water or the like during coating.
Moreover, if drying time is normal temperature (0-40 degreeC), for example, it is preferable that it is about 1 hour or more, and also about 2 to 24 hours.

<Third film forming material>
In the present invention, a third film forming material can be applied onto the second film forming material surface. The third film forming material can protect the finished surface or improve the aesthetics.

The third film forming material is not particularly limited, but preferably includes a binder.
Examples of the binder include acrylic resin, urethane resin, vinyl acetate resin, vinyl chloride resin, epoxy resin, urethane resin, silicon resin, fluorine resin, acrylic vinyl acetate resin, acrylic urethane resin, acrylic silicon resin, and the like. These 1 type (s) or 2 or more types can be used.

Further, the third film-forming material can also be provided with aesthetics by containing colored particles together with the binder.
As the colored particles, for example, at least one or more selected from natural aggregates such as natural stones and pulverized natural stones and artificial aggregates such as colored aggregates can be used in addition to the pigments described above. For example, marble, granite, serpentine, granite, fluorite, cryolite, feldspar, limestone, quartzite, quartz sand, crushed stone, mica, siliceous shale, and pulverized products thereof, ceramic pulverized product, ceramic pulverized product, glass pulverized product , Glass beads, glass flakes, resin pulverized products, resin beads, rubber particles, plastic pieces, metal particles, vegetable powder particles and the like, and those obtained by color coating these surfaces. Colored resin particles and colored gel particles can also be used.

In addition to the above components, the third film-forming material includes a thickener, a film-forming aid, a leveling agent, a wetting agent, a plasticizer, an antifreezing agent, a pH adjuster, an extender, an antiseptic, as necessary. Agent, antifungal agent, anti-algae agent, antibacterial agent, dispersant, antifoaming agent, adsorbent, fiber, cross-linking agent, UV absorber, antioxidant, catalyst, solvent, water, etc. It is possible to mix within the range not to be done.
The third film-forming material can be produced by uniformly stirring and mixing the above-described components by a conventional method.

As a method of applying the third film forming material, for example, it can be applied using a known coating tool such as a brush, a trowel, a roller, or a spray.
The coating amount of the third film forming material is preferably 0.05 kg / m ² or more and 0.5 kg / m ² or less, more preferably 0.1 kg / m ² or more and 0.4 kg / m ² or less. Also, if it contains colored particles preferably 0.1 kg / ^{m 2} or more 4 kg / ^{m 2} or less, more preferably it may be coated with 0.3 kg / ^{m 2} or more 3 kg / ^{m 2} or less.

  The third film forming material can be used alone or in combination of two or more. When two or more third film forming materials are used, two colors can be obtained by using the third film forming materials having different colors. It is also possible to finish the above multicolor appearance.

  Examples and comparative examples are shown below to clarify the features of the present invention.

<Manufacture of first film forming material>
Each component (main agent, curing agent) was uniformly mixed and stirred at a ratio shown in Table 1 by a conventional method to produce a first film forming material. In addition, what was shown below was used as a raw material, respectively.

-Epoxy resin A: Mineral spirit solution of phenol novolac bisphenol A epoxy resin, solid content 50 wt%, epoxy equivalent (solid content) 950 g / eq
Epoxy resin B: A mineral spirit solution of phenol novolac bisphenol A epoxy resin, solid content 50 wt%, epoxy equivalent (solid content) 730 g / eq
-Epoxy resin C: Mineral spirit solution of phenol novolac bisphenol A epoxy resin, solid content 50 wt%, epoxy equivalent (solid content) 550 g / eq
Amine curing agent A: aliphatic polyamidoamine, solid content 100% by weight, active hydrogen equivalent (solid content) 80 g / eq
Amine curing agent B: aliphatic polyamidoamine, solid content 100% by weight, active hydrogen equivalent (solid content) 230 g / eq
Silane compound: N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane Hydrocarbon solvent: mixture of mineral spirit and aromatic hydrocarbon Alcohol solvent A: isopropyl alcohol, SP value 11.5
Alcohol solvent B: n-butyl alcohol, SP value 11.4
Alcohol solvent C: benzyl alcohol, SP value 12.1
・ Additives: Urethane thickener, silicone antifoam

<Manufacture of second film forming material>
Each component was uniformly mixed and stirred at a ratio shown in Table 2 by a conventional method to produce a second film forming material. In addition, what was shown below was used as a raw material, respectively.

Aqueous resin 1: Epoxy crosslinkable aqueous resin (carboxyl group / epoxy group-containing core-shell type acrylic styrene resin emulsion (solid content 50 wt%, total Tg-5 ° C.))
Aqueous resin 2: Epoxy crosslinkable aqueous resin (carboxyl group / epoxy group-containing core-shell type acrylic styrene resin emulsion (solid content 50 wt%, total Tg-52 ° C.))
Aqueous resin 3: Epoxy crosslinkable aqueous resin (carboxyl group / epoxy group-containing core-shell type acrylic styrene resin emulsion (solid content 50 wt%, total Tg 53 ° C.))
Inorganic particles 1: Titanium oxide (average particle size 0.3 μm, specific gravity 4.2)
Inorganic particles 2: calcium carbonate (average particle size 1 μm, specific gravity 2.6)
Inorganic particles 3: calcium carbonate (average particle size 4 μm, specific gravity 2.6)
・ Additives: Alcohol-based solvent, glycol-based film-forming aid, polycarboxylic acid-based dispersant, urethane-based thickener, silicon-based antifoaming agent

(Test 1)
72 hours after spray coating the first film-forming material at a coating amount of 0.15 kg / m ² on the base material (coating siding board (former coating film: silicone resin coating film)) in the combinations shown in Table 3 Next, the second film forming material was roller-coated at a coating amount of 0.3 kg / m ² and then dried for 24 hours to obtain a test specimen.
About the obtained test body, finished appearance (swelling, peeling, cracking, etc.) was visually evaluated. The evaluation was performed in three stages (excellent: A>B> C: inferior), with “A” being superior in finish and “C” being inferior in finish. The results are shown in Table 3.

(Test 2)
After the test specimen prepared in Test 1 was immersed in water for 14 days, adhesion was evaluated by a cross-cut tape method according to JIS K 5600-5-6. The results are shown in Table 3. The evaluation criteria are as follows.
5: No defect part 4: The area of the defect part is less than 10% 3: The area of the defect part is 10% or more and less than 25% 2: The area of the defect part is 25% or more and less than 40% 1: The area of the defect part is 40% that's all

(Test 3)
About the test body produced in Test 1, after providing a distance of 60 cm and irradiating an infrared lamp for 8 hours and then immersing it in water at 23 ° C. for 16 hours for a total of 10 cycles, the appearance change was visually observed. Observed. The evaluation is made in four stages (A>B>C> D) where “A” indicates that no defect (swelling, peeling, etc.) is observed, and “D” indicates that a defect is clearly observed. )

For Example 10, the specimen obtained in Example 1 was roller-coated with an acrylic resin-based glossy paint as a third film forming material at a coating amount of 0.3 kg / m ² for 24 hours. Tests 1 to 3 were carried out using the dried test specimens.

Claims (1)

A film forming method for applying a first film forming material and a second film forming material to a base material in order,
The first film-forming material contains an epoxy resin and an amine curing agent,
The epoxy equivalent of the epoxy resin is 500 g / eq or more and 2000 g / eq or less,
The active hydrogen equivalent of the amine curing agent is 50 g / eq or more and 200 g / eq or less,
The active hydrogen equivalent of the amine curing agent and the epoxy equivalent of the epoxy resin are less than 0.4 in [active hydrogen equivalent of the amine curing agent / epoxy equivalent of the epoxy resin],
The second film-forming material forms a film having a pigment volume concentration of 20% or more and 80% or less and an elongation of 30% or more and 800% or less in an atmosphere at 20 ° C. .