JP2017066232A - Two-liquid type paint composition and coated article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-liquid type paint composition having excellent low-temperature curability.SOLUTION: A two-liquid type paint composition comprises a solvent-free main agent comprising polyol, aromatic diamine, a zinc containing catalyst and a bismuth containing catalyst, and a solvent-free curing agent comprising aliphatic polyisocyanate.SELECTED DRAWING: None

Description

  The present invention relates to a two-component coating composition and a coated product obtained by coating the two-component coating composition, and particularly relates to a two-component coating composition having excellent low-temperature curability.

  In recent years, methods for applying a thermal barrier paint when repairing an outdoor structure or paving a road have been studied. Japanese Patent Application Laid-Open No. 2004-19121 (Patent Document 1) describes a method of applying a radical crosslinking type two-component room temperature curable resin solution to the surface layer of a pavement, where absorption is performed in the visible wavelength range. It has been proposed to add a pigment exhibiting reflection in the infrared wavelength region to the resin liquid. JP-A-2009-155552 (Patent Document 2) describes a solvent-free two-component coating composition in which a urethane resin is formed after coating, and in the infrared region by blending a thermal barrier pigment. A method has been proposed for reducing the solar radiation absorption rate. JP 2012-158709 A (Patent Document 3) describes a solvent-free two-component coating composition similar to that of Patent Document 2, but by blending dicyclohexylmethane diisocyanate as a polyisocyanate compound, A method has been proposed in which the compatibility with the polyol compound or the like below is made favorable, thereby ensuring low-temperature curability.

Japanese Patent Laid-Open No. 2004-19121 JP 2009-155552 A JP 2012-158709 A

  However, the two-component room-temperature curable resin liquid described in Patent Document 1 is a radical crosslinking type, and actually contains an acrylate monomer. For this reason, an odor is generated during painting, which has a great influence on the working environment and has been regarded as a problem.

  Moreover, since the two-component coating composition described in Patent Documents 2 and 3 is a coating composition in which a urethane resin is formed after coating and is solvent-free, it can solve the problem of odor but is low-temperature curable. There was still room for improvement (specifically, curability at 5 ° C. or lower). In particular, paint compositions used outdoors are focused on being able to paint in all regions throughout the season, and there is a need for paint compositions that can be painted even in low-temperature environments such as winter and cold regions. .

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and provide a two-component coating composition having excellent low-temperature curability and a coated product obtained by coating the two-component coating composition.

  The present inventor examined two-component paint compositions as described in Patent Documents 2 and 3, and these two-component paint compositions generally include tin such as dibutyltin laurate as a curing catalyst. Contained catalyst is used, but tin-containing catalyst is known to solidify in low temperature environment, and depending on the composition of paint, sufficient catalytic action of this tin-containing catalyst is not obtained under low temperature environment I understood. Tin-containing catalysts are environmentally hazardous substances. Under such circumstances, the present inventor can exhibit excellent catalytic action without causing solidification in a low-temperature environment, and also examines a curing catalyst that does not have an environmental load, and reactivity with polyisocyanate used as a curing agent. As a result of a study on a high diamine compound, a two-component coating composition having excellent low-temperature curability is obtained by combining a zinc-containing catalyst and a bismuth-containing catalyst as a curing catalyst and an aromatic diamine as a diamine compound. The present invention has been found out and the present invention has been completed.

  That is, the two-component coating composition of the present invention is characterized by comprising a solvent-free main agent containing a polyol, an aromatic diamine, a zinc-containing catalyst and a bismuth-containing catalyst, and a solvent-free curing agent containing an aliphatic polyisocyanate. To do.

  In a preferred example of the two-component coating composition of the present invention, the aliphatic polyisocyanate has a biuret structure.

  In another preferable example of the two-component coating composition of the present invention, the total content of the zinc-containing catalyst and the bismuth-containing catalyst in the two-component coating composition is 0.1 to 2.0% by mass, and zinc The mass ratio (A / B) of the containing catalyst (A) and the bismuth-containing catalyst (B) is 0.1 to 0.8.

  In another preferred embodiment of the two-component coating composition of the present invention, the aromatic diamine is diethylmethylbenzenediamine.

  In another preferable example of the two-component coating composition of the present invention, the volume ratio (C: D) of the solventless main agent (C) and the solventless curing agent (D) is 1.00: 0.95. 1.00: 1.05.

  In another preferable example of the two-component coating composition of the present invention, the solventless main agent further contains a heat shielding pigment.

  In another preferred embodiment of the two-component coating composition of the present invention, the solventless main agent further comprises hollow particles.

  The coated product of the present invention can be obtained by coating the above two-component coating composition.

  According to the present invention, it is possible to provide a two-component coating composition having excellent low-temperature curability and a coated product obtained by coating the two-component coating composition.

  Hereinafter, the two-component coating composition of the present invention will be described in detail. The two-component coating composition of the present invention is characterized by comprising a solvent-free main agent containing a polyol, an aromatic diamine, a zinc-containing catalyst and a bismuth-containing catalyst, and a solvent-free curing agent containing an aliphatic polyisocyanate.

  The two-component coating composition of the present invention is composed of a main agent and a curing agent, and is used, for example, by mixing the main agent and the curing agent during coating. The coating film obtained by the application of the two-component coating composition of the present invention contains a resin having a urethane bond or a urea bond synthesized by a reaction of an aliphatic polyisocyanate and a polyol or an aliphatic polyisocyanate and an aromatic diamine.

  In the two-component coating composition of the present invention, the main agent and the curing agent are solventless types and do not contain a solvent such as water or an organic solvent, but the compounding agent contained in the main agent or the curing agent contains a solvent. Some of them are commercially available in the state, and it may be difficult to completely remove the solvent during preparation of the main agent or curing agent. For this reason, in the two-component coating composition of the present invention, the solvent-free main agent and the solvent-free curing agent are the content of the solvent such as water or organic solvent of 5% by mass or less, preferably 0% by mass. Means an agent.

  In the two-component coating composition of the present invention, the volume ratio (C: D) of the solventless main agent (C) and the solventless curing agent (D) is 1.00: 0.95 to 1.00: 1.05. It is preferable that If the volume ratio of the solventless main agent and the solventless curing agent is within the above specified range, management during coating and storage becomes easy. For example, assuming a solvent-free main agent and a solvent-free curing agent whose volume ratio is within the above specified range, when the total of the hydroxyl group of the polyol and the amino group of the aromatic diamine contained in the solvent-free main agent is 1 equivalent It is actually used by adjusting the amount of polyol, aromatic diamine and aliphatic polyisocyanate so that the amount of isocyanate group contained in the solvent-free curing agent is 0.5 to 1.5 equivalents. Possible two-part coating compositions can be prepared.

  In the two-component coating composition of the present invention, the solvent-free main agent includes a polyol, an aromatic diamine, a zinc-containing catalyst, and a bismuth-containing catalyst.

A polyol is a compound having two or more hydroxyl groups, and forms a urethane bond by reacting with an isocyanate group of an aliphatic polyisocyanate. The number (n) of hydroxyl groups per molecule of polyol can be determined from the following formula using the hydroxyl value (OHV) and number average molecular weight (Mn) of the polyol.
n = Mn (g / mol) × OHV (mg KOH / g) / 56110
Here, the hydroxyl value is the number of mg of potassium hydroxide required to neutralize a free hydroxyl group in 1 g of a sample after complete acetylation with acetic anhydride. The number average molecular weight is a polystyrene-reduced number average molecular weight measured by gel permeation chromatography.

  The polyol preferably has a number average molecular weight of 300 to 10,000, and more preferably 400 to 2,000. In addition, the number of hydroxyl groups per molecule is preferably 2.3 to 9.0, and more preferably 2.5 to 5.0.

  The polyol is preferably a liquid. Specifically, the liquid is preferably a liquid having a viscosity of not more than 100,000 mPa · s at 23 ° C., and more preferably a liquid having a viscosity of 500 to 5,000 mPa · s at 23 ° C. In the present invention, the viscosity of the polyol is a value measured at 60 rpm using a B-type viscometer at a liquid temperature of 23 ° C.

  Examples of the polyol include acrylic polyol, polyester polyol, polyurethane polyol, and polyether polyol. The acrylic polyol is obtained by copolymerizing a hydroxyl group-containing (meth) acrylic acid ester and a compound having a polymerizable unsaturated group. Examples of the hydroxyl group-containing (meth) acrylic acid ester include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like. . Examples of the compound having a polymerizable unsaturated group excluding a hydroxyl group-containing (meth) acrylic acid ester include styrene, vinyltoluene, (meth) acrylic acid, fumaric acid, maleic acid, (meth) acrylic acid ester, (meth) acrylamide, Examples include (meth) acrylonitrile. These compounds having a polymerizable unsaturated group may be used alone or in combination of two or more. Polyester polyols include polyhydric alcohols such as ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, propylene glycol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, phthalic acid and maleic acid. , Trimellitic acid, adipic acid, glutaric acid, succinic acid, sebacic acid, pimelic acid, suberic acid and other polybasic carboxylic acids. In addition, during this dehydration condensation reaction, hydroxyl group-containing fatty acid esters obtained by decomposing natural oils such as soybean oil, linseed oil, rice bran oil, cottonseed oil, tung oil, castor oil, and palm oil with polyhydric alcohols are converted into polyhydric alcohols. It can also be used as all or part of the above. The polyurethane polyol is composed of the above polyhydric alcohol, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4′-methylene bis (cyclohexyl isocyanate), methylcyclohexane diisocyanate, bis (isocyanate methyl). It can be obtained by reacting polyisocyanate such as cyclohexane, isophorone diisocyanate, dimer acid diisocyanate, lysine diisocyanate and the like under an alcohol excess condition. Further, the hydroxyl group-containing fatty acid ester can be used for the synthesis of a polyurethane polyol by using all or part of the polyhydric alcohol. The polyether polyol is obtained, for example, by adding an alkylene oxide such as ethylene oxide or propylene oxide to the polyhydric alcohol or the hydroxyl group-containing fatty acid ester. In addition, these polyols may be used independently and may be used in combination of 2 or more type.

  In the two-component coating composition of the present invention, the content of polyol is appropriately adjusted according to the amount of functional group of aromatic diamine or aliphatic polyisocyanate as described later. The polyol content in is preferably 50 to 80% by mass.

  Aromatic diamines react with aliphatic polyisocyanates faster than polyols, which can shorten the time to complete curing and adjust the viscosity of the paint during curing compared to using polyols alone. it can.

  Specific examples of the aromatic diamine include diethyldiaminotoluene, 4,4′-diamino-3,3′-dichlorodiphenylmethane, 2,4-diaminotoluene, 2,6-diaminotoluene, diethylmethylbenzenediamine (1-methyl -3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, etc.), 1,3,5-triethyl-2,6-diaminobenzene, 4, 4'-diaminodiphenylmethane, 3,5,3 ', 5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,5-dimethylthio-2,4-toluenediamine, 3,5-dimethylthio-2,6-toluene Examples include diamines. These aromatic diamines may be used alone or in combination of two or more.

  Moreover, as an aromatic diamine, diethylmethylbenzenediamine is preferable. Since the two-component coating composition of the present invention is excellent in low-temperature curability, it can be suitably used as a coating composition to be used outdoors. However, for example, when used for road painting, the curing of the coating composition is completed. In some cases, an anti-slip aggregate (for example, gravel or sand) is applied and fixed in the coating film. At this time, it is necessary to secure the viscosity and time until completion of curing to such an extent that the aggregated material can be sufficiently fixed in the coating film. At the same time, the time until completion of curing is not too long, and coating is repeated. In some cases, it must be usable without problems. Here, when diethylmethylbenzenediamine is used as an aromatic diamine, viscosity and time until completion of curing can be secured to such an extent that the sown aggregate can be sufficiently dispersed in the coating film, and the time until completion of curing is long. Therefore, the present inventors have found that it can be used without problems even when coating is repeated.

  In the two-component coating composition of the present invention, the content of the aromatic diamine is appropriately adjusted according to the amount of the functional group of the polyol or aliphatic polyisocyanate as described later. The content of the aromatic diamine in is preferably 10 to 30% by mass.

  In the two-component coating composition of the present invention, an excellent low-temperature curing is achieved by using a combination of a zinc-containing catalyst and a bismuth-containing catalyst as a curing catalyst that catalyzes the reaction between an aliphatic polyisocyanate and a polyol or aromatic diamine. Sex can be achieved. A zinc-containing catalyst can be used without causing solidification even in a low-temperature environment, but when a zinc-containing catalyst is used alone as a curing catalyst, sufficient curability cannot be ensured. Bismuth-containing catalysts can also be used without solidification even in a low-temperature environment, but when a bismuth-containing catalyst is used alone as a curing catalyst, the coating strength is higher than when used in combination with a zinc-containing catalyst. Lower. For this reason, a two-component coating composition having excellent low-temperature curability can be provided only by a combination of a zinc-containing catalyst and a bismuth-containing catalyst.

  Examples of zinc-containing catalysts include zinc octoate, zinc octylate, zinc naphthenate, fatty acid zinc, diethylzinc-based catalyst, zinc hexacyanocobaltate complex, zinc acetate, zinc acetylacetonate, zinc tallate, hydroxylated Zinc, zinc-2-ethylhexoate, zinc stearate, zinc octoate, zinc hexanoate, zinc 2-ethylhexanoate, zinc acetylacetonate, bis (zinc monoacetoacetate) oxide, bis (zinc monoacetate Salt) oxide, zinc dibenzoylmethane, zinc-2-ethyl octoate, zinc bis (2-ethylhexanoate), zinc laurate and the like. Examples of the bismuth-containing catalyst include organic bismuth compounds, bismuth carboxylates, bismuth neodecanoate, bismuth octylate, dibismuth trioxide, bismuth tris (2-ethylhexanoate), bismuth nitrate, bismuth tris (neodecanoate), bismuth. Examples thereof include carboxylate, bismuth 2-ethylhexanoate, bismuth octoate, and bismuth neodecanoate. In addition, these zinc containing catalysts and bismuth containing catalysts may be used independently and may be used in combination of 2 or more types.

  In the two-component coating composition of the present invention, the mass ratio (A / B) of the zinc-containing catalyst (A) and the bismuth-containing catalyst (B) is preferably 0.1 to 0.8.

  In the two-component coating composition of the present invention, the total content of the zinc-containing catalyst and the bismuth-containing catalyst is preferably 0.1 to 2.0% by mass. If the total content of the zinc-containing catalyst and the bismuth-containing catalyst is less than 0.1% by mass, sufficient curability may not be ensured. On the other hand, if the total content exceeds 2.0% by mass, the time until curing is completed is shortened. It may be too much.

  In the two-component coating composition of the present invention, the solventless curing agent contains an aliphatic polyisocyanate. In addition, it is preferable that content of aliphatic polyisocyanate in a solvent-free hardener is 80-100 mass%.

  Polyisocyanate is a compound having a plurality of isocyanate groups (NCO groups), but among these polyisocyanates, aliphatic polyisocyanates are known as polyisocyanates that have relatively low reactivity and that can also improve weather resistance. Examples include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, and the like, including modified products of these aliphatic polyisocyanates. It is. Specific examples of the modified product include a biuret modified product, an isocyanurate modified product, an adduct modified product (for example, trimethylolpropane adduct), an allophanate modified product, and a uretdione modified product. In particular, various modified products of hexamethylene diisocyanate and various modified products of isophorone diisocyanate are preferable from the viewpoint of weather resistance. In addition, these aliphatic polyisocyanates may be used alone or in combination of two or more.

  In addition, as the aliphatic polyisocyanate, an aliphatic polyisocyanate having a biuret structure (that is, a biuret modified product) is preferable. The aliphatic polyisocyanate having a biuret structure is excellent in compatibility with the solvent-free main agent, and the finish of the coating film is good.

  In the two-component coating composition of the present invention, the content of the aliphatic polyisocyanate is 0.5 to 1.5 equivalents of isocyanate group when the total of the hydroxyl group of the polyol and the amino group of the aromatic diamine is 1 equivalent. It is preferable that

  The aliphatic polyisocyanate is preferably a liquid. Specifically, the liquid is preferably a liquid having a viscosity of 100,000 mPa · s or less at 23 ° C., and more preferably a liquid having a viscosity of 100 to 5000 mPa · s at 23 ° C. In the present invention, the viscosity of the aliphatic polyisocyanate is a value measured at 60 rpm using a B-type viscometer at a liquid temperature of 23 ° C.

  The two-component coating composition of the present invention can contain various pigments, but preferably contains a heat-shielding pigment from the viewpoint of use outdoors. A heat-shielding pigment refers to a pigment that does not absorb light in the near-infrared wavelength region (wavelength: 780 nm to 2500 nm) or has a low light absorptance for light in the near-infrared wavelength region (wavelength: 780 nm to 2500 nm). Examples of the heat shielding pigment include a black heat shielding pigment, a white heat shielding pigment, a red heat shielding paint, a blue heat shielding pigment, and a yellow heat shielding pigment. Examples of black heat shielding pigments include azomethiazo pigments, perylene pigments, aniline pigments, composite oxide fired pigments, and examples of white heat shielding pigments include titanium oxide. These thermal barrier pigments may be used alone or in combination of two or more.

  In the two-component coating composition of the present invention, the pigment may be blended in either the solventless main agent or the solventless curing agent, but is usually blended in the solventless main agent. In the two-component coating composition of the present invention, the pigment content is preferably 5 to 40% by mass.

  The two-component coating composition of the present invention preferably further contains hollow particles. The hollow particles are particles having a cavity inside the shell (outer shell). For this reason, when a coating film contains a hollow particle, a heat insulation effect can be provided to a coating film and a flame retardance can be improved. Examples of the hollow particles include spherical hollow particles, fibrous hollow particles, tube-shaped hollow particles, and sheet-shaped hollow particles. By using hollow particles in the coating composition, the specific gravity of the coating composition can be reduced. As a result, a coating composition that is difficult to sag even when coated with a thick film and has good coating workability can be obtained.

  The hollow particles are not particularly limited, and various types can be used. For example, hollow particles can be classified according to the material, and include hollow particles made of organic materials such as resins, hollow particles made of inorganic materials such as glass, silica, alumina, zirconia, carbon, ceramics, and volcanic glass. However, since the storage stability of the paint becomes good, hollow particles of inorganic material are more preferable. These hollow particles may be used individually by 1 type, and may be used in combination of 2 or more types.

The hollow particles preferably have an average particle size of 10 to 80 μm, and more preferably 20 to 60 μm. If the average particle diameter of the hollow particles is less than 10 μm, the viscosity of the coating may increase. If the average particle diameter of the hollow particles exceeds 80 μm, the coating film formability is lowered and the smoothness of the coating film is lowered. There is a case. The average particle size of the hollow particles refers to the 50% particle size (D ₅₀ ) of the volume-based particle size distribution, and is determined from the particle size distribution measured using a particle size distribution measuring device (for example, a laser diffraction / scattering particle size distribution measuring device). be able to. The particle diameter of the hollow particles is represented by a sphere equivalent diameter by a laser diffraction / scattering method.

The hollow particles preferably have a true density of 0.2 to 1.2 g / cm ³ , and more preferably 0.2 to 0.8 g / cm ³ . When the true density is less than 0.2 g / cm ³ , the stability of the hollow particles in the paint is lowered during kneading, painting, and storage. When the true density exceeds 1.2 g / cm ³ , the viscosity of the paint may increase, and it is difficult to obtain the merit (lowering the specific gravity of the paint) by blending the hollow particles. The true density can be measured using a pycnometer (gas phase substitution type true density meter, for example, AccuPycII1340 manufactured by Micromeritics).

  The hollow particles preferably have a pressure strength of 2 to 200 MPa. When the pressure strength is less than 2 MPa, the stability of the hollow particles in the paint is lowered during kneading, painting, and storage, as in the case where the true density is low. The compressive strength is defined by ASTM D 3102-78, and an appropriate amount of hollow particles is put in glycerin and pressurized, and the pressure at which 10% by volume is broken is used as an index.

  In the two-component coating composition of the present invention, the hollow particles may be blended in either the solventless main agent or the solventless curing agent, but are usually blended in the solventless main agent. In the two-component coating composition of the present invention, the content of the hollow particles is preferably 2 to 10% by mass.

  The two-component coating composition of the present invention includes a rust inhibitor, a dispersant, an antifoaming agent, a dehydrating agent, a leveling agent, an anti-settling agent, an anti-sagging agent, an anti-algae agent, an antifungal agent, an antiseptic, and an ultraviolet absorber. You may mix | blend an agent, a light stabilizer, etc. suitably as needed.

  The two-component coating composition of the present invention comprises a solventless main agent and a solventless curing agent, and these can be prepared by mixing various components appropriately selected as necessary.

  Next, the coated article of the present invention will be described in detail. The coated product of the present invention can be obtained by coating the above-described two-component coating composition of the present invention, but the coating method is not particularly limited, but the time from mixing the main agent and curing agent to curing is very long. Therefore, it is preferable to use a two-liquid collision mixing type airless spray coating machine that can be mixed and sprayed immediately before coating. In addition, the film thickness after hardening is 200-500 micrometers, for example.

  The coating of the two-component coating composition of the present invention is preferably performed on an asphalt pavement surface. The asphalt pavement surface uses asphalt mixture obtained by mixing aggregate and asphalt of various particle sizes as the surface layer, and is classified according to the particle size of the aggregate to be used and the construction method. For example, there are dense particle size asphalt having excellent wear resistance and open particle size asphalt having excellent water permeability.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Examples 1-7)
According to the formulation shown in Table 1, the raw materials were mixed to prepare the main agents of Examples 1-7.
In Examples 1 and 3 to 7, a modified aliphatic polyisocyanate biuret (trade name: Desmodur N3200A, manufactured by Sumika Bayer Urethane Co., Ltd.) is used as the curing agent. In Example 2, the curing agent is used. As an aliphatic polyisocyanate isocyanurate modified product (trade name: Sumidur N3300, manufactured by Sumika Bayer Urethane Co., Ltd.).

  In Examples 1 to 7, when the main agent and the curing agent are mixed at a volume ratio of 1.00: 1.00, the total of the hydroxyl group of the polyol and the amino group of the aromatic diamine in the main agent is 1.0 equivalent. In this case, the isocyanate group in the curing agent is 1.1 equivalents.

In Table 1, the compounding agents used for the main ingredients are as follows.
Polyol: castor oil-modified polyol resin (trade name: URIC-H420, manufactured by Ito Oil Co., Ltd.)
Aromatic diamine ... diethylmethylbenzenediamine (trade name: ETHACURE100, manufactured by ALBEMARLE)
Curing catalyst A: Mixed catalyst of bismuth tris (2-ethylhexanoate) and zinc 2-ethylhexanoate (mixing ratio: about 1: 1) (trade name: BorchiKat 0244, manufactured by OMG Borchers GmbH)
Curing catalyst B ... 2-ethylhexanoic acid zinc (trade name: BorchiKat22, manufactured by OMG Borchers GmbH)
Curing catalyst C ... bismuth tris (2-ethylhexanoate) (Brandi: BorchiKat24, manufactured by OMG Borchers GmbH)
Thermal barrier pigment A: Titanium oxide white pigment (trade name: Taipei CR-97, manufactured by Ishihara Sangyo Co., Ltd.)
Thermal barrier pigment B ... Azomethiazo black pigment (trade name: Chromofine A-1103, manufactured by Dainichi Seika Kogyo Co., Ltd.)
Coloring pigment: Carbon black (trade name: Mitsubishi Carbon Black, manufactured by Mitsubishi Chemical Corporation)

(Comparative Examples 1-4)
According to the formulation shown in Table 2, the raw materials were mixed to prepare the main agents of Comparative Examples 1 to 4.
Moreover, in Comparative Examples 1-4, the aliphatic polyisocyanate biuret modified body (Brand name: Death module N3200A, Sumika Bayer Urethane Co., Ltd. product) was used as a hardening | curing agent.

  In Comparative Examples 1 to 3, when the main agent and the curing agent are mixed at a volume ratio of 1.00: 1.00, the total of the hydroxyl group of the polyol and the amino group of the aromatic diamine in the main agent is 1.0 equivalent. In this case, the isocyanate group in the curing agent is 1.1 equivalents.

  In Comparative Example 4, when the main agent and the curing agent are mixed at a volume ratio of 1.00: 1.00, the total of the hydroxyl group of the polyol and the amino group of the aromatic diamine in the main agent is 1.0 equivalent. The isocyanate group in the curing agent is 1.2 equivalents.

  In Table 2, the polyether diamine is “Jeffamine D230” manufactured by Huntsman, and the curing catalyst D is dibutyltin dilaurate (trade name: Neostan U-100, manufactured by Nitto Kasei Co., Ltd.). Other compounding agents are as described in Table 1.

  Various evaluation was performed about Examples 1-7 and Comparative Examples 1-4. In any evaluation, the volume ratio when mixing the main agent and the curing agent was 1.00: 1.00.

(Evaluation of low-temperature curability)
Immediately after mixing the test paint in a 5 ° C. environment, it was applied to a tin plate using a 20 mil applicator (500 μm), and the time until the tackiness of the paint film disappeared was measured.
In order to fix the non-slip aggregates to be applied after painting, the coating film drying speed must not be too fast, and in order to perform recoating quickly, the curing speed must not be too slow. Generally, it is preferable that the time from coating to the absence of tackiness is about 30 minutes. The evaluation results are shown in Tables 3 and 4.

(Evaluation of coating film appearance)
About the test piece coated by the same method as evaluation of low temperature curability, the external appearance evaluation of the coating film was performed visually.
When the compatibility between the main agent and the curing agent is poor, the coating film becomes cloudy, resulting in poor appearance. Judgment criteria are as follows. The evaluation results are shown in Tables 3 and 4.
○: Coating film appearance is good without turbidity △: Part of coating film is thin and cloudy ×: Entire coating film appearance is cloudy

(Evaluation of coating strength)
The coating film hardness was evaluated in accordance with the method defined in JIS K 5600-5-9 Mechanical Properties of the Coating-Wear Resistance (Wear Wheel Method). Specifically, the test paint was air-sprayed at room temperature on a disc-shaped test plate having a diameter of 6.35 mm and a center hole having a diameter of 100 mm, sufficiently dried, and then tested under the following conditions. The abrasion loss of the coating film after the test was measured. The evaluation results are shown in Tables 3 and 4.
Test conditions Wear wheel type: CS-17
Load: 1kg
Number of revolutions: 5000

(Measurement of brightness)
Using a color difference meter (trade name: CR-400, light source used: D light source, manufactured by Konica Minolta Sensing Co., Ltd.) on the test piece coated in the same manner as in the evaluation of low-temperature curability, L ^* ) was measured. The evaluation results are shown in Tables 3 and 4.

(Measurement of solar reflectance)
Using a 20 mil applicator, paint the test paint on black-and-white concealment rate test paper (specified in JISK5600-4-1 4.1.2, manufactured by Nippon Test Panel Co., Ltd.) at room temperature, and in accordance with JIS K5602 Rate test paper The reflectance of the black ground coating film was measured from 250 nm to 2500 nm with a spectrophotometer (trade name: UV3100PC; manufactured by Shimadzu Corporation), and the near-infrared wavelength region (780 nm to 2500 nm) and all wavelength regions ( The solar reflectance of the coating film was determined from 300 nm to 2500 nm. Furthermore, one decimal place of the obtained value was rounded off according to JIS Z 8401. Furthermore, in the near-infrared wavelength region solar reflectance ρ and brightness L ^* obtained in each coating film, when L ^* exceeds 40.0, a coating satisfying ρ ≧ L ^* has a heat shielding property. When the film was determined to be a film and L ^* was 40.0 or less, it was determined that the film satisfying ρ ≧ 40.0 was a heat-shielding coating film. In addition, the thermal insulation evaluation criteria are as follows. The evaluation results are shown in Tables 3 and 4.
○: When L ^* exceeds 40.0, ρ ≧ L ^*
When L ^* is 40.0 or less, ρ ≧ 40.0 is satisfied. ×: When L ^* exceeds 40.0, ρ ≧ L ^* is not satisfied.
When L ^* is 40.0 or less, ρ ≧ 40.0 is not satisfied

Claims (8)

  A two-component coating composition comprising a solvent-free main agent containing a polyol, an aromatic diamine, a zinc-containing catalyst, and a bismuth-containing catalyst, and a solvent-free curing agent containing an aliphatic polyisocyanate.   The two-component coating composition according to claim 1, wherein the aliphatic polyisocyanate has a biuret structure.   The total content of the zinc-containing catalyst and the bismuth-containing catalyst in the two-component coating composition is 0.1 to 2.0% by mass, and the mass ratio of the zinc-containing catalyst (A) and the bismuth-containing catalyst (B) (A The two-component paint composition according to claim 1 or 2, wherein / B) is 0.1 to 0.8.   The two-component coating composition according to claim 2, wherein the aromatic diamine is diethylmethylbenzenediamine.   The volume ratio (C: D) of the solventless main agent (C) and the solventless curing agent (D) is 1.00: 1.05 to 1.00: 0.95. The two-component coating composition according to any one of -4.   The two-component coating composition according to any one of claims 1 to 5, wherein the solvent-free main agent further contains a heat-shielding pigment.   The two-component coating composition according to any one of claims 1 to 6, wherein the solvent-free main agent further contains hollow particles.   A coated product obtained by coating the two-component coating composition according to any one of claims 1 to 7.