JP2018001054A - Method for coating road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for coating a road capable of sufficiently securing miscibility of a main agent and a curing agent without causing a failure caused by curing a coating material in a coating apparatus.SOLUTION: A method for coating a road with a coating material composition containing a main agent containing a polyol resin and amine and a curing agent containing isocyanate includes: a step of heating each of the main agent and the curing agent to 50-70°C and setting each viscosity thereof at 100-300 cP, and a step of separately sending the main agent and the curing agent to a coating gun, colliding and mixing the agents in the coating gun so that a volume ratio of the main agent to the curing agent is in a range of 1.00:1.05 to 1.00 to 0.95, spraying the obtained mixture to a road through a static mixer mounted on a tip portion of the coating gun, and coating the road.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a road painting method, and more particularly, to a road painting method capable of sufficiently ensuring the mixing property of a main agent and a curing agent without causing problems due to the curing of paint in a coating apparatus. .

  As a method of painting a road using a two-component paint composition composed of a main agent and a curing agent, spray painting using a paint gun is preferably used. And such a coating means can be classified by the timing which mixes a main ingredient and a hardening | curing agent. First, a technique called “collision mixing method” is known. In this method, the main agent and the curing agent are separately sent to the coating gun, both liquids are mixed by collision in the coating gun, a mixture is prepared, and this is sprayed onto the road. A technique called “static mixing method” is also known. In this method, before feeding the paint gun, for example, a few meters before the paint gun, premix the main agent and the curing agent using a static mixer, and remix the premix immediately before the paint gun. This is a method of preparing a mixture and spraying the mixture onto a road through a paint gun.

  For example, Japanese Patent Application Laid-Open No. 11-226456 (Patent Document 1) describes a spray gun that can be used as a “collision mixing type” coating means. The “collision mixing method” coating means that the main agent and the hardener are mixed in the mixing chamber of the spray gun, so there is an advantage that no clogging occurs in the liquid supply hose. There is a problem that it is not mixed and finished into a weak coating film that does not exhibit the original coating film strength.

On the other hand, Japanese Patent Application Laid-Open No. 2005-296896 (Patent Document 2) describes a spraying device that can be used as a “static mixing type” coating means. “Static mixing method” coating means that the main agent and curing agent can be mixed sufficiently, so there is a theoretical advantage of good mixing, but in the actual coating environment, the paint is likely to harden in the mixer. There is a problem that the balance of the volume ratio (A: B) of the main agent (A) and the curing agent (B) is likely to be lost, and a curing failure after coating is likely to occur.
"Static mixing method" is very difficult to manage the balance of volume ratio during painting work, and the coating after painting is difficult to cure, causing problems such as easy adhesion of dirt, It is a system that easily falls into a situation where problems during painting work become obvious.

  As described above, the conventional “collision mixing type” painting means and the “static mixing type” painting means have their advantages and disadvantages.

  Japanese Patent Application Laid-Open No. 2006-43524 (Patent Document 3) ejects a two-component curable urethane paint having a mixing module formed with an orifice that leads to a mixing chamber that collides and mixes the main agent and the curing agent. Collision mixing spray guns have been proposed, and it is described that the use of such a spray gun can improve the mixing properties of the main agent and the curing agent. Japanese Unexamined Patent Application Publication No. 2009-72690 (Patent Document 4) includes a sprayer that mixes and sprays a first raw material and a second raw material, a supply hose, a hose heater, and a hose temperature controller. An apparatus has been proposed, and it is described that a vinyl ester resin-based coating film can be produced by using such a spraying apparatus.

JP 11-226456 A JP 2005-296896 A JP 2006-43524 A JP 2009-72690 A

  The collision mixing spray gun described in Patent Document 3 is suitable for coating with a two-component curable urethane paint, and the spray device described in Patent Document 4 is suitable for producing a vinyl ester resin-based coating film. Conceivable. However, higher durability is demanded in road coating, and the present inventor has focused on a curing system in which urea bonds are generated in addition to urethane bonds. When an amine is contained in the main agent for the purpose of forming a urea bond, the mixing property of the main agent and the curing agent is lower than that of the two-component curable urethane coating, and the curing speed in that case is described in, for example, Patent Document 4. Therefore, different coating means are required because it is faster than a coating using a vinyl ester resin.

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and a road painting method capable of sufficiently ensuring the mixing of the main agent and the curing agent without causing problems due to the curing of the paint in the coating apparatus. Is to provide.

  As a result of diligent investigations to achieve the above object, the present inventor conducted collision mixing of a main agent and a curing agent adjusted to a specific temperature and viscosity at a specific volume ratio, and then mixing in a static mixer. The inventors have found that the mixing ability of the main agent and the curing agent can be sufficiently ensured without causing problems due to the curing of the paint in the coating apparatus, and have completed the present invention.

That is, the road painting method of the present invention is a method of painting a road with a coating composition containing a main component containing a polyol resin and an amine and a curing agent containing an isocyanate,
A step of heating each of the main agent and the curing agent to 50 to 70 ° C. and setting each viscosity to 100 to 300 cP;
The main agent and the curing agent, the temperature and viscosity of which have been adjusted by the above steps, are separately fed into the coating gun, and the volume ratio (A: B) of the main agent (A) and the curing agent (B) is 1.00: 1.05. In the range of 1.00: 0.95, collision mixing is carried out in the paint gun, and the resulting mixture is sprayed on the road through a static mixer attached to the tip of the paint gun. Is performed.

  In a preferred embodiment of the road coating method of the present invention, the flow rate when the mixture obtained by the impingement mixing passes through the static mixer is 100 to 1500 cm / sec.

  In another preferred embodiment of the road coating method of the present invention, the main agent and the curing agent are of a solventless type.

  In another preferred embodiment of the road coating method of the present invention, the distance that the mixture obtained by the collision mixing passes through the static mixer is 3 to 10 cm.

  In another preferred embodiment of the road coating method of the present invention, the total mass of the coating gun and the static mixer is less than 2 kg.

  ADVANTAGE OF THE INVENTION According to this invention, the coating method of the road which can fully ensure the mixing property of a main ingredient and a hardening | curing agent can be provided, without causing the malfunction by hardening of the coating material in a coating device.

BRIEF DESCRIPTION OF THE DRAWINGS It is drawing for demonstrating an example of the road coating method of this invention, and demonstrates supply to a coating gun from the heating of a main ingredient and a hardening | curing agent in detail. It is drawing for demonstrating an example of the coating method of the road of this invention, and demonstrates the collision mixing in a coating gun, mixing in a static mixer, and spraying in detail. An example of the static mixer which can be used for the road coating method of the present invention is shown.

  The road painting method of the present invention will be described in detail below. The road coating method of the present invention is a method of painting a road with a coating composition containing a main component containing a polyol resin and an amine and a curing agent containing an isocyanate, and each of the main agent and the curing agent is set to 50 to 70 ° C. The process of heating and setting each viscosity to 100-300 cP, and the main agent and the curing agent whose temperature and viscosity are adjusted by the above-mentioned steps are separately sent to the coating gun, and the main agent (A) and the curing agent (B). When the volume ratio (A: B) is in the range of 1.00: 1.05 to 1.00: 0.95, collision mixing is performed in the coating gun, and the resulting mixture is attached to the tip of the coating gun. And a process of spraying the road through the static mixer and painting the road.

  The road that is the object to be coated in the coating method of the present invention is not particularly limited and includes general roads, highways, sidewalks, and the like, but asphalt paved roads are preferable from the viewpoint of coating film adhesion. Asphalt pavement usually uses an asphalt mixture in which aggregates of various particle sizes and asphalt are mixed as a 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.

  The coating composition (hereinafter also referred to as a two-component coating composition) used in the coating method of the present invention is composed of a main agent and a curing agent, and is used by mixing the main agent and the curing agent during coating. . The coating film obtained by the coating of the coating composition contains a resin having a urethane bond or a urea bond that is synthesized by a reaction between an isocyanate and a polyol resin or a reaction between an isocyanate and an amine. Since such a resin has a urea bond, it is excellent in durability as compared with a urethane resin.

  In the two-component coating composition, it is preferable that each of the main agent and the curing agent is a solventless type. "Solvent-free type" means that it does not contain water or organic solvents, but in fact, the compounding agent contained in the main agent or curing agent is commercially available in a state containing a solvent. In some cases, it is difficult to completely remove the solvent during preparation of the main agent and the curing agent. For this reason, in the present invention, the solvent-free main agent and the solvent-free curing agent mean a main agent and a curing agent having a content of a solvent such as water or an organic solvent of 5% by mass or less, preferably 0% by mass.

  In the two-component coating composition, the main agent contains a polyol resin and an amine, and the curing agent contains an isocyanate. Here, the SP values of the polyol resin and the isocyanate are both preferably in the range of 10-13. More preferably, it is in the range of 10.5 to 12.5. If the SP value of the polyol resin and the isocyanate is within the above specified range, the mixing property of the main agent and the curing agent can be further improved and the adhesion to the road can be improved. Asphalt is present on the road surface for the purpose of paving, but if it is a polyol resin and isocyanate having an SP value in the above specified range, the asphalt is dissolved and melted, and the adhesion with the road is improved. Conceivable.

  The SP value (solubility parameter) is an index indicating the dissolving power determined based on the cohesive energy and molecular volume per unit functional group. In the present invention, the SP value (solubility parameter) is calculated using the Fedors equation. did. For details on the Fedors equation, see R. F. According to Fedors, Polymer Engineering and Science, 14, (2), 1974, p. 147.

  In the coating method of the present invention, the volume ratio (A: B) of the main agent (A) and the curing agent (B) is mixed within the range of 1.00: 1.05 to 1.00: 0.95 during coating. It is preferable. If the volume ratio of the main agent and the curing agent is within the above specified range, management during painting and storage becomes easy. For example, assuming a main agent and a curing agent having a volume ratio within the above specified range, and including the equivalent of the total of the hydroxyl group of the polyol resin and the amino group of the amine contained in the main agent, included in the curing agent. The coating composition which can be actually used can be prepared by adjusting the compounding quantity of a polyol resin, an amine, and isocyanate so that the quantity of the isocyanate group used may be 0.5-1.5 equivalent.

  The polyol resin used for the main agent is a resin having two or more hydroxyl groups, and forms a urethane bond by reacting with an isocyanate group. Here, the polyol resin preferably has a molecular weight in the range of 350 to 800. In the present invention, the molecular weight of the polyol resin is a number average molecular weight in terms of polystyrene measured by gel permeation chromatography.

  The polyol resin preferably has a hydroxyl value in the range of 200 to 400. In particular, the polyol resin has a polyol resin (a) having a hydroxyl value of 300 or more and 400 or less, and a polyol resin (having a hydroxyl value of 200 or more and less than 300, for balancing the viscosity and curing time. It is preferable to include two types of polyol resins having different hydroxyl values, b), and the mass ratio (a: b) of the polyol resin (a) to the polyol resin (b) is in the range of 9: 1 to 5: 5. It is preferable that In the coating method of the present invention, the volume ratio (A: B) of the main agent (A) and the curing agent (B) is mixed within the range of 1.00: 1.05 to 1.00: 0.95. If the polyol resin (a) having a high hydroxyl value is not used, the isocyanate group becomes excessive. Further, by using a polyol resin (a) having a high hydroxyl value, the curing rate is increased and a hard coating film tends to be formed. On the other hand, the higher the hydroxyl value of the polyol resin, the higher the viscosity. Therefore, in order to balance the viscosity and the curing time, a combination of the polyol resin (a) having a high hydroxyl value and the polyol resin (b) having a low hydroxyl value is used. preferable. The hydroxyl value of the polyol resin (a) is preferably 300 or more and 350 or less, and the hydroxyl value of the polyol resin (b) is preferably 250 or more and less than 300. 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.

  Examples of the polyol resin 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. 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 polyol resins may be used independently and may be used in combination of 2 or more type.

  In the two-component coating composition, the content of the polyol resin is appropriately adjusted according to the amount of the functional group of amine or isocyanate as described later. For example, the content of the polyol resin in the main agent is It is preferable that it is 50-85 mass%.

  The amine used in the main agent reacts faster with the isocyanate than the polyol resin, so shorten the time to completion of curing and adjust the viscosity of the paint during curing compared to using the polyol resin alone. Can do.

  The amine is preferably a compound having a plurality of amino groups. Specific examples include alkylene diamines such as ethylene diamine and hexamethylene diamine; alkylene polyamines such as diethylene triamine, triethylene tetramine and tetraethylene pentamine; norbornane diamine and 1,3-bis. (Aminomethyl) cyclohexane, 1,2-diaminocyclohexane, 1,4-diamino 3,6-diethylcyclohexane, alicyclic polyamines such as isophoronediamine; 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 , -Diaminobenzene, etc.), 1,3,5-triethyl-2,6-diaminobenzene, 4,4'-diaminodiphenylmethane, 3,5,3 ', 5'-tetraethyl-4,4'-diaminodiphenylmethane, 3 Aromatic diamines such as 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine. In addition, these amines may be used independently and may be used in combination of 2 or more types.

  In the two-component coating composition, the amine content is appropriately adjusted according to the amount of the functional group of the polyol resin or isocyanate as will be described later. For example, the amine content in the main agent is 10 It is preferable that it is -30 mass%.

  In the two-component coating composition, the main component preferably further contains a silicone-based surface conditioner. By blending the silicone-based surface conditioner, the dispersion stability of the coating composition is improved, the occurrence of white mottled patterns caused by coating unevenness can be prevented, and a coating film having excellent aesthetics can be obtained. Although it does not specifically limit as a silicone type surface conditioning agent, Although a commercial item can be used conveniently, Specifically, polyether modified silicone, polyester modified silicone, polydimethylsiloxane, polymethylalkylsiloxane etc. are mentioned, for example. . The content of the silicone-based surface conditioner in the main agent is preferably, for example, 0.1 to 0.5% by mass.

  The two-component coating composition can contain various pigments, but preferably contains a heat-shielding pigment from the viewpoint of painting a road. 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, the pigment may be blended in either the main agent or the curing agent, but is usually blended in the main agent. For example, the pigment content in the main agent is preferably 5 to 25% by mass.

  The isocyanate used for the curing agent is a compound having a plurality of isocyanate groups (NCO groups), and includes, for example, aliphatic, aromatic or araliphatic polyisocyanates. Specific examples include tolylene diisocyanate, 4 , 4'-diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane diisocyanate, bis (isocyanate methyl) cyclohexane, isophorone diisocyanate, dimer acid diisocyanate, lysine diisocyanate, etc. These modified polyisocyanates are listed. 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. Among these, various modified products of hexamethylene diisocyanate and various modified products of isophorone diisocyanate are preferable from the viewpoints of curability and weather resistance. These polyisocyanates may be used alone or in combination of two or more. In addition, it is preferable that content of the isocyanate in a hardening | curing agent is 80-100 mass%.

  In the two-component coating composition, the isocyanate content is preferably 0.5 to 1.5 equivalents when the total of the hydroxyl group of the polyol resin and the amino group of the amine is 1 equivalent.

  The two-component coating composition includes a curing catalyst, a dispersant, an antifoaming agent, a dehydrating agent, a leveling agent, an anti-settling agent, an anti-sagging agent, an algae-proofing agent, an anti-fungal agent, an antiseptic, an ultraviolet absorber, a light You may mix | blend a stabilizer etc. suitably as needed.

  In the two-component coating composition, the main agent and the curing agent can be prepared by mixing various components appropriately selected as necessary.

  In the two-component coating composition, the main agent and the curing agent each preferably have a viscosity at 60 ° C. in the range of 100 cP to 300 cP. If the viscosity of the main agent and the curing agent is within the above specified range, the mixing property can be improved. In the present invention, the viscosity is a value measured by a B-type viscometer (paint liquid temperature 60 ° C., rotation speed 60 rpm).

  The road painting method of the present invention is a method of painting a road with the above-described coating composition. First, each of the main agent and the curing agent is heated to 50 to 70 ° C., and each viscosity is set to 100 to 300 cP. Including a step (first step). If the viscosity of the main agent and the curing agent at the specified temperature is within the specified range, the mixing properties of the main agent and the curing agent can be improved. The reason for heating the main agent and the curing agent to 50 to 70 ° C. is to make the fluidity suitable for spraying and to improve the mixing property of the main agent and the curing agent.

  In the road coating method of the present invention, next, the main agent and the curing agent whose temperature and viscosity are adjusted in the first step are separately fed to the coating gun, and the main agent (A) and the curing agent (B) are mixed. When the volume ratio (A: B) is in the range of 1.00: 1.05 to 1.00: 0.95, collision mixing is performed in the coating gun, and the resulting mixture is attached to the tip of the coating gun. After passing through the static mixer, the road is sprayed and the road is painted (second step). According to the road coating method of the present invention, the mixture is sufficiently mixed with the main agent and the curing agent by sequentially receiving the collision mixing in the coating gun and the subsequent mixing in the static mixer. In addition, it is possible to prevent problems caused by the curing of the paint in the coating apparatus. It is preferable that the time for which the mixture obtained by the impingement mixing is mixed in the static mixer is not so long from the viewpoint of preventing problems due to the curing of the paint in the coating apparatus, for example, 0.002 seconds to 2 seconds. It is preferably within the range, and more preferably within the range of 0.002 seconds to 1 second. In the specification of the present application, the time from when the mixture obtained by collision mixing moves into the static mixer until it passes through the static mixer and is discharged from the discharge unit provided at the tip of the static mixer is expressed as “ The mixing time in the static mixer ”.

  In the road coating method of the present invention, the volume ratio (A: B) of the main agent (A) and the curing agent (B) when colliding and mixing in the coating gun is 1.00: 1.05-1.00. : Within the range of 0.95. If the volume ratio of the main agent and the curing agent is within the above specified range, it is easy to manage the liquid feeding to the coating gun.

  In the road coating method of the present invention, the collision mixing of the main agent and the curing agent is performed in the coating gun. Here, the coating gun is a collision gun for the collision mixing among the coating guns usually used for spray coating. A spray gun can be used. Here, the collision mixing is performed by the collision between the main agent and the hardener which are misted by pressure inside the coating gun.

  In the road painting method of the present invention, a mixture obtained by collision mixing in a coating gun is supplied to a static mixer. In the present invention, the mixture is applied by pressure applied during collision mixing. It is possible to supply to a static mixer, and to discharge from a discharge unit provided at the tip of the static mixer. Of course, the mixture is also mixed when passing through the static mixer. Here, as the static mixer, a static mixer as shown in FIG. 3 described later can be used.

  In the road coating method of the present invention, the flow rate when the mixture obtained by collision mixing in the coating gun passes through the static mixer is preferably 100 to 1500 cm / sec. By adjusting the flow rate of the mixture within the above specified range, the mixing property of the main agent and the curing agent becomes good, and a coating film having excellent appearance and mechanical strength is obtained. In the road coating method of the present invention, the flow rate of the mixture can be easily adjusted by adjusting the liquid temperatures of the main agent and the curing agent.

  In the road coating method of the present invention, the distance that the mixture obtained by collision mixing in the coating gun passes through the static mixer is preferably 3 to 10 cm. If the distance through which the mixture passes is within the above specified range, the paint is cured in the static mixer, and sufficient mixing properties can be obtained without causing gun clogging.

  In the road coating method of the present invention, the total mass of the coating gun and the static mixer is preferably less than 2 kg. The lower limit of the total mass of the coating gun and the static mixer is not particularly limited, but is, for example, 1 kg or more.

  In the road coating method of the present invention, the road is painted by spraying the mixture passing through the static mixer on the road. In the present invention, the road painting method is usually attached to the tip of the collision mixing spray gun. The discharge part which is present can be attached to the static mixer and sprayed from the discharge part using the pressure applied during the collision mixing.

  The road painting method of the present invention can be carried out as shown in the following drawings. FIG. 1 is a drawing for explaining an example of a road coating method according to the present invention, in which supply of a main agent and a curing agent from heating to a coating gun is described in detail. FIG. 2 is a drawing for explaining an example of a road painting method according to the present invention, in which collision mixing in a painting gun, mixing in a static mixer, and spraying are described in detail. FIG. 3 shows an example of a static mixer that can be used in the road coating method of the present invention.

  As shown in FIG. 1, the main agent and the curing agent are placed in separate tanks, sucked up by a heating device, and circulated independently of each other, and the main agent and the curing agent are heated by a heater in the heating device. Warm the agent. In addition, the main ingredient and the hardening | curing agent are prepared so that the viscosity in 50-70 degreeC may be 100-300 cP. After the main agent and the curing agent are raised to a predetermined temperature, they are fed to the collision mixing gun through separate lines (for example, a hose), and are collision-mixed inside the collision mixing gun. In the process shown in FIG. 1, a normal collision-mixing type coating apparatus can be used, but in a commercially available coating apparatus, the heating apparatus may be referred to as a coating machine.

  As shown in FIG. 2, the main agent and the curing agent are supplied to the collision mixing gun from separate lines, and collision mixing is performed inside the collision mixing gun. Also, as shown in FIG. 2, a static mixer is attached to the tip of the collision mixing gun, and the mixture obtained by the collision mixing is further passed through the static mixer by the pressure applied during the collision mixing. Mixed and sprayed. In addition, although not shown in figure, the discharge part is attached to the front-end | tip of a static mixer.

  FIG. 3 shows an example of a static mixer that can be used in the road coating method of the present invention. The illustrated static mixer includes a metal mixer case and a plastic static mixer inserted into the mixer case, and is used with one end of the mixer case attached to a collision mixing gun. The discharge portion is attached to the other end portion. In addition, the plastic static mixer of the example of illustration is detachable and can be replaced | exchanged easily.

  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 1-9)
The coating tests of Examples 1 to 9 were performed according to the formulation and coating conditions shown in Table 1.
The coating apparatus used in the coating tests of Examples 1 to 9 includes the configuration described in FIGS. 1 and 2, and details thereof are as follows. In addition, the coating system using the coating apparatus of this structure is described as “impact static”.
Heating device (coating machine): Reactor E-XP2, Graco collision mixed airless gun: Prober P-2, Graco
Static mixer kit: static diameter 6mm, number of elements 8, mixer length 5cm, Graco spray tip model number: 751, weight of collision mixing type airless gun with Graco static mixer kit attached: 1kg

The compounding agents used for the main ingredients in Table 1 and Table 2 are shown below.
Polyol resin A: castor oil-modified polyol (trade name: URIC-H420, manufactured by Ito Oil Co., Ltd.) Molecular weight: 550, hydroxyl value: 320
Polyol resin B: castor oil-modified polyol (trade name: URIC-H62, manufactured by Ito Oil Co., Ltd.) Molecular weight: 450, hydroxyl value: 260
Aromatic diamine ... diethylmethylbenzenediamine (trade name: ETHACURE100, manufactured by ALBEMARLE)
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 Co., Ltd.)
Curing catalyst: Mixed catalyst of bismuth tris (2-hexanoate) and zinc 2-ethylhexanoate (trade name: BorchiKAt0244, manufactured by OMG Borchers GMB)
Polyisocyanate-modified aliphatic polyisocyanate biuret (trade name: Desmodur N3200A, manufactured by Sumika Covestro Urethane Co., Ltd.)
Solvent: Xylene (manufactured by Sumitomo Chemical Co., Ltd.)

(Comparative Examples 1-5)
The coating tests of Comparative Examples 1 to 5 were performed according to the formulation and coating conditions shown in Table 2.
The coating apparatus used in the coating test of Comparative Example 1 is a collision mixing type coating apparatus that does not include a static mixer. Specifically, it is a coating apparatus comprising the heating device shown below, a collision-mixing airless gun attached to the heating device via a hose, and a spray tip attached to the tip of the collision-mixing airless gun. . A coating method using the coating apparatus having this configuration is referred to as “collision mixing”.
Heating device (coating machine): Reactor E-XP2, Graco collision mixed airless gun: Prober P-2, Graco spray tip model number: 751, Graco This is a static mixing type coating device that is not equipped. Specifically, the heating device shown below, a static mixer attached to the heating device via a hose, an airless gun attached to the static mixer via a hose, and attached to the tip of the airless gun A spraying device comprising a spray tip. The coating method using the coating apparatus having this configuration is referred to as “static”.
Heating device (coating machine): Reactor E-XP2, Graco static mixer: static mixer diameter 6 mm, number of elements 32
Airless gun: SG3, Graco spray tip Model number: XHP851, Graco The coating apparatus used in the coating test of Comparative Example 3 is a static mixing type coating apparatus that does not include a collision mixing gun. Specifically, the heating device shown below, a static mixer attached to the heating device via a hose, an airless gun attached to the static mixer via a hose, and attached to the tip of the airless gun A spraying device comprising a spray tip. The coating method using the coating apparatus having this configuration is also expressed as “static” as in Comparative Example 2.
Heating device (coating machine): Hydra Cat HP, Graco static mixer: Static mixer diameter 6 mm, number of elements 18
Airless gun: SG3, Graco spray tip Model number: Rotating tip 429, Graco The coating apparatus used in the coating tests of Comparative Examples 4 and 5 is the same as the coating apparatus used in the coating test of the example.

  Various evaluation was performed about Examples 1-9 and Comparative Examples 1-5. The evaluation results are shown in Tables 3 and 4. Except for the evaluation of coating film strength, water-permeable asphalt (porous asphalt) was used as an object to be coated.

(Appearance evaluation)
The appearance of the coating film 2 hours after coating was visually evaluated. When the mixing property of the main agent and the curing agent is poor, the coating film becomes clouded and discolored, resulting in poor appearance. The criteria for evaluation are as follows.
○: No abnormality in the appearance of the coating film.
Δ: A defect such as color separation is partially observed.
X: Problems such as color separation are observed throughout the coating film.

(Evaluation of contamination)
After spraying carbon powder on the coating film 24 hours after coating, it was washed with water and wiped off to evaluate the contamination state. When the mixing ratio of the main agent and the curing agent is poor and the main agent and the curing agent are mixed at an inappropriate ratio, even when a sufficient curing time has elapsed, the adhesiveness remains on the coating film, and dirt is likely to adhere. The evaluation criteria are shown below.
○: No carbon contamination △: Partial carbon contamination ×: Full carbon contamination

(Evaluation of dryness in low temperature environment)
In an environment where the outside air temperature was 5 ° C., the dry state when the surface of the coating film was touched 2 hours after coating was evaluated. When the mixing property of the main agent and the curing agent is poor, the curing rate of the coating film becomes slow. The evaluation criteria are shown below.
○: Tack is not felt when touching the coating film △: Tack remains slightly when touching the coating film ×: Uncured state

(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, a test paint was applied to 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 weight loss of wear was measured. When the mixing property of the main agent and the curing agent is good, the coating film strength is improved. Here, when the coating film depletion amount is 200 mg or less, particularly excellent coating film strength is exhibited. In the table, the coating film depletion amount (mg) is shown.
Test conditions:
Wear wheel type: CS-17
Load: 1kg
Number of revolutions: 5000

(Evaluation of paint workability)
The painting workability was evaluated according to the following criteria.
○: The painting work can be performed without any problem. ×: Problems that make the painting work difficult occur. Here, the troubles that make the painting work difficult are hardening in the painting line or inside the gun, and the painting work continues immediately. Indicates a difficult situation.

Claims (5)

A method of painting a road with a coating composition containing a polyol resin and an amine-containing main agent and an isocyanate-containing curing agent,
A step of heating each of the main agent and the curing agent to 50 to 70 ° C. and setting each viscosity to 100 to 300 cP;
The main agent and the curing agent, the temperature and viscosity of which have been adjusted by the above steps, are separately fed into the coating gun, and the volume ratio (A: B) of the main agent (A) and the curing agent (B) is 1.00: 1.05. In the range of 1.00: 0.95, collision mixing is carried out in the paint gun, and the resulting mixture is sprayed on the road through a static mixer attached to the tip of the paint gun. A process comprising the steps of:   The method according to claim 1, wherein a flow rate when the mixture obtained by the impingement mixing passes through a static mixer is 100 to 1500 cm / second.   The method according to claim 1 or 2, wherein the main agent and the curing agent are of a solventless type.   The method according to any one of claims 1 to 3, wherein a distance that the mixture obtained by the collision mixing passes through the static mixer is 3 to 10 cm.   The method according to claim 1, wherein a total mass of the coating gun and the static mixer is less than 2 kg.

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