KR20170129050A - Nano-surface protector and its manufaturing method therof - Google Patents

Abstract

The present invention relates to an environmentally friendly nano-surface protecting material for reducing heat island for preventive maintenance of asphalt roads, and a manufacturing method thereof. According to the present invention, when the nano-surface protecting material for reducing heat island is coated on a surface of a finely damaged asphalt road, a preventive maintenance method can be provided to increase the durability of the roads by filling the damaged part with the asphalt, thereby prolonging a lifespan of the roads. Further, the present invention has various characteristics of low noises caused by absorption of frictional sounds with a vehicle due to a unique open cell structure of the present invention, smooth permeability, such as rainwater, saltwater resistance for preventing corrosion and damage of the roads by calcium chloride, reduction of a heat island phenomenon caused by asphalt road due to a light reflection phenomenon using nano silica on a surface, and the like.

Description

TECHNICAL FIELD [0001] The present invention relates to a nano-surface protecting material and a method for manufacturing the same,

The present invention relates to a nano-surface protection material and a method for manufacturing the same, and more particularly, to an environmentally-friendly heat-insulated nano surface protection material for preventive maintenance of asphalt roads and a method for manufacturing the same.

Asphalt is known to contain saturated hydrocarbons, aromatic hydrocarbons, resins and asphaltenes. Asphalt is a very viscoelastic and highly binding material and widely used for road paving.

 However, since the asphalt is repeatedly expanded and contracted by the temperature change, the static and dynamic load and the unevenness of the stress applied by the vehicle due to the increase of the traffic amount over time cause cracks and damage. Asphaltization of asphalt due to aging of the road surface due to oxidation and corrosion, such as corrosion and damage, direct sunlight and storm, loses the flexibility and elasticity of asphalt and causes cracks due to subsidence, etc. When these phenomena accumulate, plastic deformation, Port hole phenomenon.

 Various methods have been applied to solve these problems. As disclosed in Korean Patent Publication No. 2010-0008480, when the petroleum-based (SBS or SBR) polymer particles are melted in the asphalt used for the asphalt road to increase the viscosity, But it is difficult to control quality and it is likely to be cracked due to low temperature and calcium chloride. It contains volatile harmful substances, polycyclic aromatic hydrocarbons and harmful heavy metals due to the use of petroleum polymer, metal catalyst and plasticizer, .

 Conventionally, the damaged part of the asphalt concrete pavement is cut or chipped, and then the overlaying method is used. However, this method may be cracked and broken again due to the temperature difference between the existing packaging and the re-packaging surface, Therefore, it is difficult to bond with new packaging material, so that it is easily separated after repairing the packaging due to cracks around the cut surface, and it takes a lot of time and cost to construct, and there is a problem that waste wasted after road cutting is generated.

 On the other hand, the heat island phenomenon is a phenomenon in which the temperature of the city is higher than the surrounding area due to the effects of air pollution or artificial heat. Asphalt roads are heated to 60 ~ 70 ℃ due to solar heat in the summer and the temperature of the asphalt pavement A large amount of infrared rays are radiated from the infrared light source, thereby accelerating the heat island phenomenon of the city. As a method for reducing the heat island phenomenon, there are a reflection type carburizing method for preventing the rise of the surface temperature by reflecting the sunlight on the surface, and a water evaporation type method for making a hole in the surface of the road pavement to evaporate moisture therein. However, the water evaporation type process has the drawbacks of slow evaporation of water and difficult maintenance to remain in the hole for a long time, and maintenance which has to regularly replenish water for a certain period of time.

 Such road damage may lead to dangerous accidents for road users, and in the case of repacking roads for repairing, it takes a lot of time and takes a long time, which leads to a serious obstacle to vehicle communication. Therefore, in consideration of cost reduction of repair and quickness of construction, there is a desperate need for environmentally friendly and various preventive materials to be applied at the time of occurrence of micro crack, which is an early stage of road cracking.

The present invention relates to an environmentally friendly heat-resistant nano-surface protecting material for preventive maintenance of asphalt roads and a method of manufacturing the same.

The present invention aims to provide a nano-surface protective material which can recover cracks on a damaged asphalt road with a single coating to improve fatigue cracking and port hole breakage by enhancing durability of roads and prolong the service life of roads and a method for manufacturing the same. do.

It is another object of the present invention to provide a nano-surface protective material capable of improving low-noise through absorption of tea and fric- tion noise, corrosion resistance and corrosion resistance by calcium chloride, chemical resistance, water permeability and water- do.

It is another object of the present invention to provide a nanosurface protection material and a method of manufacturing the nanosurface protection material that can reduce the heat island phenomenon by lowering the temperature of the road surface due to solar thermal effect.

According to one embodiment of the present invention, there is provided a surface protection material for forming a surface protection layer for extending lifetime of an asphalt road and reducing heat island phenomenon, Wherein the hard segment comprises an isocyanate compound and the soft segment is a polyurethane compound that is soluble in a polyol and in an organic solvent, the polyurethane compound comprising a hard segment and a soft segment, wherein the hard segment comprises an isocyanate compound, The present invention relates to a nano-surface protective material containing an asphalt solid content.

In one embodiment of the present invention, the isocyanate group of the isocyanate compound of the present invention and the -OH group of the polyol may be contained in a molar ratio of 0.5: 1 to 5: 1.

In one embodiment of the present invention, the isocyanate of the present invention may be prepared by reacting an isocyanate such as diphenyl methane diisocyanate (MDI), tolunene diisocyanate (TDI), hexamethylene diisocyanate (HDI), dicyclohexyl Dicyclohexylmethane diisocyanate (H ₁₂ MDI), and isophorone diisocyanate IPDI; Isoporoned iisocyanate).

In one embodiment of the present invention, the polyol of the present invention is a polyether polyol, a polyester polyol, neopentyl glycol, methylpropanediol, 1.6 hexanediol, ethylene glycol, propylene glycol, 1.4 butylene glycol, 1.3 butylene glycol, Propane and trimethylol ethane. ≪ tb > < / TABLE >

In one embodiment of the present invention, the asphalt solids dissolved in the organic solvent of the present invention may contain 30 to 90 parts by weight of asphalt solids based on the weight of the dissolved solution.

In one embodiment of the present invention, the organic solvent of the present invention may be selected from the group consisting of toluene, xylene, ethyl acetate, butyl acetate, ethyl alcohol, butyl alcohol and isopropyl alcohol.

In one embodiment of the present invention, the asphalt solids dissolved in the polyol and the organic solvent of the present invention may be contained in an amount of 5 to 90 parts by weight based on the content of the polyol.

In one embodiment of the present invention, the polyurethane compound of the present invention may contain the hard segment portion in the range of 20 to 70% by weight.

In one embodiment of the present invention, the polyol of the present invention is a linear type polyol and has a weight average molecular weight (Mw) of 500 to 3000.

In one embodiment of the present invention, the polyurethane compound of the present invention has an NCO% of 6 to 13% by weight.

In one embodiment of the present invention, the present invention provides a process for preparing an isocyanate-terminated prepolymer, comprising: 1) reacting an isocyanate compound and a polyol to prepare an isocyanate-terminated prepolymer; 2) mixing the asphalt solids in an organic solvent to prepare a mixture; And 3) adding the mixture of step 2) to the isocyanate-terminated prepolymer of step 1).

In one embodiment of the present invention, the polyol of step 1) of the present invention has a hydroxyl value of 55-80.

In one embodiment of the present invention, the mixture of step 2) of the present invention contains 40 to 80 parts by weight of asphalt solids based on the weight of the total mixture.

In an embodiment of the present invention, the step 3) of the present invention is a process for producing a mixture by adding a mixture of step 2) to an isocyanate-terminated prepolymer of step 1), wherein the asphalt solid content 90 parts by weight.

According to the present invention, the following effects can be expected.

 First, in the production of the present invention, since additives such as harmful heavy metal catalyst, petroleum oil and plasticizer are not used, harmful heavy metals and volatile organic substances are not emitted, so that environmentally friendly products can be produced.

 Second, by filling the cracks caused by damaged asphalt deformation, flexibility and elasticity can be restored. By improving the structural durability, it is possible to solve cracks and portholes, thereby prolonging the life of roads and saving waste and cost in road maintenance.

 Third, since the open cell structure of the present invention provides flexibility and elasticity, frictional sound with a car can be absorbed to reduce noise, thereby replacing installation of a sound barrier, thereby reducing cost.

 Fourth, due to the characteristics of salt water resistance and chemical resistance, it is possible to prevent corrosion and damage of road pavement caused by calcium chloride used for winter snow removal.

 Fifth, by using inorganic additive, heat accumulation can be fundamentally blocked by solar thermal effect, which can reduce the heat island effect of the city.

FIG. 1 is a flow chart of a method for producing a nano-surface protective material of the present invention.

 The present invention relates to an environmentally friendly heat-resistant nanoparticle surface protection material and a method for manufacturing the same, for coating the surface of a slightly damaged asphalt road to prolong road life.

 In particular, in the present invention, by using an environmentally friendly polyisocyanate compound, it is possible to improve the physical performance of a broken road, thereby preventing plastic deformation and breakage problems such as portholes on the road.

 At the same time, it has effects such as low noise due to the absorption of tea and fricatives, smooth drainage and water permeability of water, salt water resistance, chemical resistance and reduction of heat island phenomenon due to solar thermal effect, so it is economical and efficient This is an excellent advantage.

 1 of the present invention is a flowchart of a method for producing a nano-surface protective material, comprising the steps of: 1) reacting an isocyanate compound and a polyol to prepare an isocyanate-terminated prepolymer (S100); 2) mixing the asphalt solids in the organic solvent to prepare a mixture (S200); And 3) adding the mixture of step 2) to the isocyanate-terminated prepolymer of step 1) to prepare a polyurethane mixture (S300).

More specifically, the above 1) step (S100) produces an isocyanate-terminated prepolymer, which is produced by the reaction of an isocyanate compound and a polyol, and is an isocyanate-terminated prepolymer. The isocyanate compound may be selected from the group consisting of diphenyl methane diisocyanate (MDI), tolunene diisocyanate (TDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI ; dicyclohexylmethane diisocyanate), and isophorone diisocyanate IPDI; Isoporoned diisocyanate. In this case, only one isocyanate compound may be used, but two or more isocyanate compounds may be used in combination. Wherein the polyol is selected from the group consisting of polyether polyol, polyester polyol, neopentyl glycol, methylpropanediol, 1.6 hexanediol, ethylene glycol, propylene glycol, 1.4 butylene glycol, 1.3 butylene glycol, trimethylol propane and trimethylolethane One or more selected.

The polyol to be used for producing the isocyanate-terminated prepolymer in the step 1) (S100) has a weight-average molecular weight (Mw) of 500 to 3000 and a polyol having a weight-average molecular weight of less than 500 There is a problem in that a soft segment for serving as a surface protective material can not be obtained.

The NCO% of the isocyanate-terminated prepolymer produced by the step 1) is 6 to 13% and the weight-average molecular weight (Mw) is 200 to 8000. To prepare an isocyanate-terminated prepolymer, the reaction of the isocyanate compound and the polyol with the -NCO group and the -OH group of the isocyanate compound is carried out at a ratio of from 0.5: 1 to 5: 1, preferably from 1.1: 1 to 2: 1, but the present invention is not limited to these examples.

The isocyanate-terminated prepolymer can be prepared by a known method. For example, by heating the diol and the isocyanate compound at 60 to 100 占 폚 for 1 to 20 hours in a dry nitrogen stream. This reaction may be carried out in an organic solvent. The chain extender reacting with the isocyanate group is preferably an active hydrogen-containing compound, that is, a diol or a diamine. The diol and the diamine have a weight average molecular weight of 1000 or more desirable. The diol compound may be selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol and 1,4-butanediol, and the diamine compound may be selected from the group consisting of ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, Diamine, and these compounds may be used singly or in combination of two or more thereof

The above 1) reaction is carried out at 25 to 150 ° C, preferably 25 to 100 ° C.

In the step S200, an asphalt solid content is mixed with an organic solvent to prepare a mixture, and the mixture is prepared by dissolving the asphalt solid content in an organic solvent. Characterized in that the asphalt solid content is contained in an amount of 30 to 90 parts by weight based on the total weight of the mixture when the asphalt solid content is dissolved in the organic solvent.

The organic solvent is selected from the group consisting of toluene, xylene, ethyl acetate, butyl acetate, ethyl alcohol, butyl alcohol and isopropyl alcohol, preferably butylacetate, but not limited to the examples.

The mixture is prepared in the above 2) step (S200), and the prepared mixture is added to the isocyanate-terminated prepolymer of the 1) step (S300). The isocyanate-terminated prepolymer of step 1) is prepared by reacting an isocyanate compound and a polyol. When the mixture is added to the isocyanate-terminated prepolymer, the asphalt solid content of the mixture is 5 to 90 parts by weight based on the content of the polyol Or preferably 40 to 50 parts by weight.

The nano surface protective material prepared by the manufacturing method according to FIG. 1 includes a polyurethane compound, and the polyurethane compound may include a hard segment and a soft segment. The combination ratio of the hard segment portion and the soft segment is such that the hard segment portion is in the range of 20 to 70 wt% and the soft segment portion is in the range of 30 to 70 wt% % ≪ / RTI > by weight.

Preferably, the Hard Segment may be included in the range of 35% to 60% by weight. If the hard segment portion is contained in an amount of less than 20% by weight, the drying time may be shortened and the hardening time of the surface protecting material may be shortened after full curing. When the hard segment is more than 70% If it is contained, the resin may become too strong after full curing, which may cause a problem in that it is difficult to serve as a surface protecting material due to impact.

When the soft segment is contained in an amount of more than 70% by weight, the drying time is decreased and the hardening time is prolonged. The hardness of the coating agent after complete curing If the soft segment is contained in an amount of less than 30% by weight, the coating film becomes too strong after full curing, which makes it difficult to serve as a coating agent.

The polyurethane compound includes a soft segment and a hard segment, and the NCO% may be 6 to 13 wt%.

The nano-surface protective material of the present invention may further comprise a foaming agent, a crosslinking agent, an inorganic additive, and a silicone foaming agent. The foaming agent, the crosslinking agent, the inorganic additive, and the silicone foaming agent are further added to the polyurethane mixture in step 3) To prepare a polyurethane mixture (S400); and 5) foaming the polyurethane mixture in the step 4) (S500).

As described above, when the polyurethane mixture includes a foaming agent, a crosslinking agent, and a silicone foaming agent, the polyurethane may include an open cell structure. Due to such a structure, the nano- When applied, it has excellent elasticity and can exhibit effective performance for absorbing noise, vibration and impact.

It restores the elasticity and flexibility of the road which has penetrated into asphaltic pavement and filled with voids. It absorbs the friction sound with the vehicle and reduces the noise. When the rain water penetrates into the open cell structure, Excellent water permeability. These characteristics can extend the lifetime of asphalt roads and reduce the driving noise of the vehicle, thereby reducing costs by replacing the effect of installing soundproof walls. By rapidly discharging rainwater during rain, the friction force of the road surface is maintained to reduce the water film phenomenon, Water splashing, water splashing phenomenon is reduced to improve the slip resistance.

The foaming agent may be included in the range of 0.2 to 3.0 parts by weight based on the weight of the polyol. When the amount of the foaming agent is less than 0.2 parts by weight, lowering of the bubble opening ratio may be caused by a low foaming agent concentration. When the amount of the foaming agent is more than 3.0 parts by weight, And mechanical abrasion due to the presence of the resin. It is also possible to connect the open cells using a crosslinking agent to have a more stable open cell structure.

Examples of the foaming agent include nitrogen, carbon dioxide, air, methyl chloride, ethyl chloride, pentane, isopentane, perfluoromethane, chlorotrifluoromethane, dichlorodifluoromethane, trichloro But are not limited to, fluoromethane, perfluoroethane, 1-chloro-1,1-difluoroethane, chloropentafluoroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, perfluoropropane, chloroheptafluoropropane , Dichlorohexafluoropropane, perfluorobutane, chlorononafluorobutane, perfluorocyclobutane, azodicarbonamide (ADCA), azodiisobutyronitrile, benzene sulfone hydrazide, 4,4-oxybenzene Sulfonyl-semicarbazide, p-toluenesulfonyl semicarbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, and Including re-hydrazino-triazine, however, not limited to this. In general, ADCA is the preferred foaming agent.

By using crosslinking agents, open cells can be connected to have a more stable open cell structure. The crosslinking agent may contain 0.02 to 4 parts by weight, preferably 0.02 to 3.0 parts by weight, more preferably 0.02 to 3 parts by weight, based on the weight of the polyol, of a crosslinking agent capable of sufficiently collecting decomposed gas generated in the foaming agent and imparting high- 0.05 to 1.5 parts by weight, and they have a one-minute half-life temperature of 130 to 180 占 폚. When the amount is less than 0.02 parts by weight, crosslinking is insufficient and the high-temperature viscoelasticity of the resin is not maintained during the decomposition of the foam. When the amount is more than 1.5 parts by weight, not only the hardness is rapidly increased but also the foam may be blown. Examples of such a cross-linking agent include t-butyl peroxyisopropyl carbonate, t-butyl peroxylylate, t-butyl peroxyacetate, di-t-butyl peroxyphthalate, t- Butyl peroxybenzoate, dicumyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, methyl ethyl ketone peroxide, t-butyl peroxydicarbonate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butyl peroxide, 2,5 Butylperoxy) valerate, a, a'-bis (t-butylperoxy) -3-hexane, n- ) Diisopropylbenzene and the like can be used.

 The silicone foam stabilizer used in the present invention facilitates the mixing of raw materials and lowers the surface tension in the synthesis of urethane, assists in the growth of the bubbles, lowers the pressure difference between the bubbles, prevents the diffusion of the gas, and prevents the urethane cell from becoming large and uneven. In addition, when the viscosity is increased, destruction of the cell due to bubble destabilization, coalescence and thinning of the cell membrane are prevented, thereby preventing the foam from being turned off.

In addition, an inorganic additive may be further included in the nano-surface protective material of the present invention in order to reduce the heat island phenomenon. Nano-surface protection materials, which include inorganic additives, are coated on the asphalt road surface to form nano-sized inorganic additive particles on the surface of the coating. These inorganic additives reflect the direct sunlight in the daytime to fundamentally block heat accumulation on the road, Reducing the phenomenon of heat re-emission to a considerable extent can alleviate heat nights, and the heat island phenomenon due to the high temperature phenomenon where the road surface temperature rises due to radiant heat even in the middle of the day can be improved. The inorganic additive is silica or a mica, and is usable without being limited to the examples. The inorganic additive may be contained in an amount of 1 to 5 parts by weight based on the weight of the polyurethane compound. When the amount of the inorganic additive is less than 1 part by weight, the effect of reducing heat island development is insufficient. When the surface protective material is applied on the asphalt road, there is a problem that the drying is slow and the drying takes a long time.

Manufacturing example  One

Poly  Preparation of urethane compounds

800 g of a dehumidified polyol having a weight average molecular weight of 3000 and a hydroxyl value of 75 to 80 was introduced as a polyether polyol, and 400 g of diphenylmethane diisocyanate was added thereto. After sufficient reaction at 75 캜, NCO And sufficiently reacted until the content became 21 wt% to prepare an isocyanate-terminated prepolymer.

400 g of asphalt solids were dissolved in butyl acetate to prepare a mixture and the asphalt solids were prepared to be 60% by weight based on the weight of the mixture.

An asphalt solid component dissolved in butyl acetate was added to the isocyanate-terminated prepolymer to prepare a polyurethane compound having an NCO content of 19% by weight so that the total solid content was 80% by weight.

Manufacturing example  2

A polyether polyol was prepared in the same manner as in Preparation Example 1, except that a dehumidified polyol having a weight average molecular weight of 2000 and a hydroxyl value of 55 to 60 was used.

Manufacturing example  3

The procedure of Preparation Example 1 was repeated except that toluene was used instead of butyl acetate to dissolve the asphalt solid content.

The polyurethane resins prepared in Preparation Examples 1 to 3 were heated to about 50 DEG C, applied to asphalt with a roller or spray, and dried naturally at room temperature to confirm their physical properties.

Example

Nano Surface on Asphalt Protection material  After application, evaluation of physical properties

Drying

We measured the time when there was no fingerprint or pressing marks when we tugged with a thumb.

Acid resistance and alkali resistance

Acid resistance was measured by immersing in 5% sulfuric acid, 5% hydrochloric acid and 5% nitric acid solution. The acid resistance was measured by immersing it in a 10% caustic soda solution to determine the alkali resistance. After immersing for 160 hours, .

Attachment

A 2 mm 100 square was cut with a knife and stuck with a 3M scotch tape. When the sample was quickly struck with a momentary force, it was confirmed that no more than 3 squares were missing.

Pencil hardness

The hardness of the film was measured with a Mitsubishi pencil hardness meter.

Properties Production Example 1 Production Example 2 Production Example 3 Drying 70 minutes 75 minutes 90 minutes Attachment 100/100 100/100 100/100 Acid resistance 5% sulfuric acid ◎ ◎ ◎ 5% nitric acid ◎ ◎ ◎ 5% hydrochloric acid ◎ ◎ ◎ Alkali resistance ◎ ◎ ◎ Zhejiang Province Good Good Good Pencil hardness 1H 1H 1H

As shown in Table 1, when the nano-surface protective materials of Production Examples 1 to 3 were applied to asphalt roads, it was confirmed that the nano-surface protective materials were dried within 70 to 90 minutes after drying. It was confirmed that changes in appearance and color change were not observed even in the test for measuring the acid resistance and alkali resistance, and the acid resistance and alkali resistance were excellent. Further, it was confirmed that the adhesiveness, shelf life and hardness were excellent.

Claims (14)

As a surface protecting material for forming a surface protective layer for extending the lifetime of an asphalt road and reducing heat island phenomenon,
Wherein the surface protection material comprises a polyurethane compound,
The polyurethane compound includes a hard segment and a soft segment,
Wherein the hard segment comprises an isocyanate compound,
Wherein the soft segment comprises an asphalt solid dissolved in a polyol and an organic solvent.
The method according to claim 1,
Wherein the isocyanate group of the isocyanate compound and the -OH group of the polyol are contained in a molar ratio of 0.5: 1 to 5: 1.
The method according to claim 1,
The isocyanate may be selected from the group consisting of diphenyl methane diisocyanate (MDI), tolunene diisocyanate (TDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (H ₁₂ MDI; dicyclohexylmethane diisocyanate, and isophorone diisocyanate IPDI; Isoporoned iisocyanate). ≪ / RTI >
The method according to claim 1,
Wherein the polyol is selected from the group consisting of polyether polyol, polyester polyol, neopentyl glycol, methylpropanediol, 1.6 hexanediol, ethylene glycol, propylene glycol, 1.4 butylene glycol, 1.3 butylene glycol, trimethylol propane and trimethylolethane At least one selected nano-surface protection material.
The method according to claim 1,
Wherein the asphalt solids dissolved in the organic solvent comprises 30 to 90 parts by weight of asphalt solids based on the weight of the dissolved solution.
The method according to claim 1,
Wherein the organic solvent is selected from the group consisting of toluene, xylene, ethyl acetate, butyl acetate, ethyl alcohol, butyl alcohol and isopropyl alcohol.
The method according to claim 1,
Wherein the asphalt solids dissolved in the polyol and the organic solvent are contained in an amount of 5 to 90 parts by weight based on the content of the polyol.
The method according to claim 1,
Wherein the polyurethane compound comprises a hard segment portion in the range of 20 to 70 wt%.
The method according to claim 1,
The polyol is a linear type polyol and has a weight average molecular weight (Mw) of 500 to 3000.
The method according to claim 1,
Wherein the polyurethane compound has an NCO% of 6 to 13% by weight.
1) reacting an isocyanate compound and a polyol to prepare an isocyanate-terminated prepolymer;
2) mixing the asphalt solids in an organic solvent to prepare a mixture; And
3) adding the mixture of step 2) to the isocyanate-terminated prepolymer of step 1).
12. The method of claim 11,
Wherein the polyol of step 1) has a hydroxyl value of 55 to 80. 2. The method of claim 1,
12. The method of claim 11,
Wherein the mixture of step 2) is 40 to 80 parts by weight of asphalt solid based on the weight of the whole mixture.
12. The method of claim 11,
The step 3) comprises adding a mixture of step 2) to an isocyanate-terminated prepolymer of step 1) to prepare a mixture,
Wherein the asphalt solid content is 70 to 90 parts by weight based on the total weight of the mixture.

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