KR100684162B1 - Foamed resin composition for urethane sheet and construction method of urethane sheet using the same - Google Patents

Abstract

Provided are a foamed resin composition for urethane sheets, which has good constructability, high shock absorption, and excellent dynamic characteristics and is usable as flooring materials for the track or sports facilities, and a construction method of urethane sheet using the same. The foamed resin composition for urethane sheets comprises a base material and a hardener. The base material includes polyisocyanate having at least two isocyanate groups in a molecule and a polyol compound having at least two hydroxyl groups in a molecule. The hardener includes a polyol compound having at least two hydroxyl groups in a molecule and hollow fillers. The hollow filler is present in the hardener in an amount of 0.5-40wt% .

Description

Resin composition for urethane sheet and construction method of urethane sheet using same {FOAMED RESIN COMPOSITION FOR URETHANE SHEET AND CONSTRUCTION METHOD OF URETHANE SHEET USING THE SAME}

1 is a cross-sectional view of a urethane sheet constructed according to an embodiment of the present invention.

2 is a photograph of a hollow filler included in the resin composition of the present invention.

Description of the main symbols in the drawings

1: first polyurethane resin layer 3: second polyurethane resin layer

5: uneven layer

The present invention relates to a resin composition for a urethane sheet and a method for constructing a urethane sheet using the same, and more specifically, by adding a hollow filler to the resin composition and using the same, there is no need for a separate foaming process during construction. Because of this, despite the work at room temperature or the external environment, the construction of the urethane resin layer containing pores inside is possible, and excellent workability. In addition, it has a low specific gravity compared to the cured urethane sheet and has a high absorption rate for a certain impact including a hollow filler in the cured product, and the hollow filler contained inside improves the vertical displacement of the resin to absorb shock. The present invention relates to a resin composition for a urethane sheet, which can be widely used as a ground track or a sports facility flooring material because of its good vertical displacement and good vertical displacement.

Polyurethane tracks are constructed primarily for track and field competitions. This minimizes the impact on the body, protects the player from injury and contributes to record reduction through improved performance.

Conventionally, polyurethane tracks are generally constructed in the order of a soft / semi-hard polyurethane layer in the order of the lower layer to the upper layer, an embossed polyurethane layer having irregularities on the surface, and a top coating polyurethane layer.

The polyurethane resin composition used for the construction of the soft / semi-hard polyurethane layer is generally composed of a bicomponent type of a main agent and a curing agent. The subject is produced by reacting a polyol compound of a specific structure with a polyisocyanate compound, and includes a urethane prepolymer having a resin end having an isocyanate reactor. When the main body and the curing agent are mixed and reacted at a predetermined mixing ratio during construction, the isocyanate reactor of the urethane prepolymer of the main body, the polyol compound of the curing agent, the hydroxyl group and / or the amino group of the chain extender react, and the molecular weight increases rapidly. Will form.

The construction of the embossed polyurethane layer proceeds in conjunction with the semi-rigid polyurethane layer construction. That is, after the soft polyurethane layer and the semi-durable polyurethane layer is applied to a predetermined thickness, the polyurethane resin is again applied to the semi-hard polyurethane layer to a predetermined thickness, and the predetermined size before the polyurethane resin is cured. The elastomeric polymer chip is sprayed onto the surface and cured in a state in which the elastic polymer chip is embedded in the polyurethane layer to form an embossed polyurethane layer. Among the spun elastic polymer chips, those not fixed in the polyurethane layer are removed using a vacuum inhaler.

Finally, a thin topcoat polyurethane layer of about 0.2 to 0.5 mm thickness is formed on the surface of the embossed polyurethane layer. Since the top coating polyurethane layer is thin, even if the top coating layer is formed, the surface layer of the finished polyurethane track remains in the form of embossing according to the profile of the lower embossed polyurethane layer.

The flexible polyurethane layer has a thickness of about 12 to 15 mm and a hardness of 25 to 45 (Shore A hardness). The semi-hard polyurethane layer has a thickness of about 12 to 15 mm and a hardness of 45 to 65 (Shore A hardness).

The impact absorption rate of the conventional polyurethane track including the soft polyurethane layer and the semi-hard polyurethane layer formed as described above is not enough to be less than about 35%, which causes problems in the joints of the athlete. That is, the shock absorbing capacity of the conventional polyurethane track needs to be further increased.

In order to improve this, some polyurethane tracks generate air foam through a soft foaming process, and due to the nature of the polyurethane track construction, the water foaming process must be performed outdoors, resulting in lack of field workability of the foaming process. As a result, construction of sports facilities such as tracks and tennis courts was impossible.

In order to solve the problems of the prior art as described above, the present invention is formed by the foaming of the foam stabilizer when the conventional urethane sheet construction is to form pores in the final urethane sheet. In this case, the problem that the construction with the same foaming density could not be achieved due to the influence of the working conditions when working at room temperature or in the external environment is solved, and it is easy to be affected by the external conditions when working at room temperature or in the external environment. An object of the present invention is to provide a urethane sheet having a hollow structure and excellent in workability and a urethane sheet construction method using the same.

Another object of the present invention is a low specific gravity compared to the cured cured urethane sheet, including a hollow filler in the cured cured resin composition for the urethane sheet to improve the absorption rate against a certain impact and a urethane sheet construction method using the same To provide.

Another object of the present invention is to improve the vertical displacement of the resin contained inside the hollow filler is good absorption of impact, but the vertical displacement is small, excellent in the movement characteristics, for urethane sheet which can be widely used as ground track or sports facility flooring It is to provide a resin composition and a urethane sheet construction method using the same.

The resin composition for urethane sheets according to one aspect of the present invention includes a subject comprising a urethane prepolymer having a polyisocyanate having at least two isocyanate groups per molecule and a polyol compound having at least two hydroxyl groups per molecule; Polyol compounds having two or more hydroxyl groups per molecule and curing agents containing hollow fillers.

In addition, the construction method of the urethane sheet according to an aspect of the present invention comprises the steps of flattening and repairing the bottom surface of the construction, applying a primer resin on the bottom surface to form a primer layer, hollow filler on the primer layer Forming a soft first polyurethane resin layer by applying a first polyurethane resin composition comprising a second polyurethane resin composition by applying a second polyurethane resin composition on the first polyurethane resin layer; Forming a ground layer, and forming an uneven layer on the second polyurethane resin layer.

In addition, the urethane sheet according to an aspect of the present invention comprises a first polyurethane resin layer comprising a hollow filler; And a second polyurethane resin layer formed on the first polyurethane resin layer and an uneven layer formed on the second polyurethane resin layer.

Hereinafter, the present invention will be described in detail.

The resin composition for urethane sheets of this invention is a component which comprises the 1st polyurethane resin layer located in the lowest part of a urethane sheet, and the said resin composition contains the hollow filler. That is, the urethane resin composition of the present invention can implement a foaming effect stably without the need for a separate foaming process during construction by including a hollow filler having a hollow inside. In addition, since the hollow filler is stably included in the cured urethane sheet, which has been finally constructed, there is an advantage of high absorption rate against impact. In addition, the hollow filler contained in the cured product has an advantage that the vertical displacement is small by improving the vertical displacement of the resin.

The urethane resin composition of the present invention as described above is a subject comprising a polyisocyanate having at least two isocyanate groups per molecule and a polyol compound having at least two hydroxy groups per molecule; And a curing agent comprising a hollow filler and a polyol compound having two or more hydroxyl groups per molecule.

The urethane prepolymer included in the subject of the resin composition for urethane sheets of the present invention is produced by reacting a polyol compound having a specific structure with a polyisocyanate, and the resulting polymer has an isocyanate reactor at the end of the resin.

The polyol compound included in the urethane prepolymer is a polyol compound having two or more hydroxy groups per molecule, and specifically, polypropylene glycol, polytetramethylglycol, or polycaprolactonediol may be used alone or in combination of two or more thereof. Can be.

The polyol compound preferably has a molecular weight of 1,000 to 8,000.

In addition, the polyol compound may be a polyether polyol, a polyester polyol, or a mixture thereof having 2 to 6, preferably 2 to 5 hydroxyl groups, and especially from an economic point of view, ethylene glycol, glycerol, butanediol, Polyethylene glycol, polypropylene glycol, polybutylene glycol, etc. obtained by addition polymerization of ethylene oxide, propylene oxide, etc. using an alcohol compound having 2 to 6, preferably 2 to 5 hydroxyl groups such as trimethylol propane as an initiator It is preferable to use polyether polyols.

The polyisocyanate reacts with the polyol compound to form a prepolymer, and specifically, methylene diphenyl isocyanate, methylene diphenyl isocyanate modified body, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, toluene diisocyanate (TDI), diphenylmethane -2,2'-diisocyanate (MDI), xylene diisocyanate (XDI), isophorone diisocyanate (IPDI), carbodiimide or urethane type modified diphenylmethane-2,2'-diisocyanate, or hexamethylene Aliphatic diisocyanates, such as diisocyanate (HDI), etc. can be used individually or in mixture of 2 or more types.

The urethane prepolymer is preferably reacted so that the equivalent ratio (NCO / OH) of polyisocyanate and polyol is 1.2 to 5.0, more preferably 1.5 to 2.5. When the equivalent ratio of the polyisocyanate and polyol is less than 1.2, crosslinking may be formed to increase the viscosity, which may be a problem in use. When the equivalent ratio of the polyisocyanate and polyol exceeds 5.0, the molecular weight is difficult to increase. There is a problem that the storage stability is poor.

The subject containing the urethane prepolymer formed as described above is preferably included in 10 to 90% by weight in the total content of the resin composition for the urethane sheet of the present invention. If the content is less than 10% by weight, there is a problem that the hardness of the final molded article is formed too high. If the content exceeds 90% by weight, the hardness of the final molded article is formed too low, which significantly reduces the applicability of the final resin composition. There is a problem.

The hardening | curing agent contained in the resin composition for urethane sheets of this invention contains the polyol compound and hollow filler which have a 2 or more hydroxyl group per molecule.

The polyol compound having two or more hydroxyl groups per molecule may be the same as the polyol compound used when preparing the urethane prepolymer of the subject, the content of which is preferably included in the curing agent 60 to 95% by weight. If the content is less than 60% by weight, there is a problem that the hardness of the final molded product is too high, and when the content exceeds 95% by weight, the hardness of the final molded product is formed too low to deviate from the hardness range required by the present invention. There is this.

In general, the construction method of the conventional urethane sheet includes the foaming agent and the foaming agent (water) component in the first polyurethane resin layer and the pores in the first polyurethane resin layer formed by foaming during the construction by the foaming agent and water-foaming. This was made to form. However, the conventional construction methods as described above are made at room temperature or continuously changing environmental conditions, and when foamed during construction in such an environment, there is a problem that foaming of uniform density is not made or foaming rate is reduced. However, in the present invention, by adding and using a hollow filler having a hollow inside to the curing agent of the urethane resin composition solves the problems caused by foaming at the same time as the conventional urethane resin composition, and stable in the cured cured urethane sheet By including the hollow filler is excellent in the shock absorption, and at the same time it is possible to improve the vertical displacement of the resin.

The hollow filler included in the curing agent of the present invention is used to reduce the weight of the urethane sheet of the present invention, improve impact absorption rate, and improve vertical displacement.

The hollow filler is a hollow glass filler made of glass (for example, US 3M, Japan, Asahi Glass, etc.), a hollow plastic film made of plastic (for example, German Akzo Nobel, Japanese Etc.), or a hollow rock (for example, volcanic rock, etc.) made by expanding water contained in the rock by applying heat of 1,000 ° C. or more.

In addition, the microcapsule foam etc. which bubbled microcapsules can also be used.

The hollow filler is preferably contained in 0.5 to 20% by weight, more preferably 1 to 15% by weight in the curing agent. If the content is less than 0.5% by weight, the content of the hollow filler contained in the cured product of the finally formed urethane sheet is low, so that the impact absorption and the degree of improvement of the vertical displacement of the resin are low. There is a problem that the effect of the many usage is insignificant.

In another aspect, the present invention provides a method for constructing a urethane sheet using the urethane resin composition as described above, the construction of the urethane sheet forming a primer layer; Forming a first polyurethane resin layer using the urethane resin composition of the present invention; Forming a second polyurethane resin layer; And forming an uneven layer.

First of all, maintenance work such as flattening the bottom surface of the place to be constructed or removing the peeled portion and adding a filler is performed.

When the preparation of the bottom surface to be worked is completed, the primer resin is applied to the bottom surface to form a primer resin layer to improve contact with the urethane sheet to be constructed.

Then, the urethane resin composition according to the above-mentioned is applied on the bottom surface to form a first polyurethane resin layer.

Since the specific kind, content, etc. of the said urethane resin composition are the same as the thing of the first half described in the said resin composition for urethane sheets, description is abbreviate | omitted. Since the first urethane resin composition includes a hollow filler, no additional foaming process is required during construction.

The urethane resin composition is applied by mixing the main material and the curing agent immediately before the coating on the primer layer, wherein the resin composition is applied so that the first polyurethane resin layer finally formed to have a thickness of 5 to 15 mm.

After the first polyurethane resin layer is formed as described above, a main body comprising a polyisocyanate having at least two isocyanate groups per molecule and a polyol compound having at least two hydroxyl groups per molecule and two or more hydroxyl groups per molecule The composition which mixed the hardening | curing agent containing the polyol compound which has a is apply | coated on the upper part of a 1st polyurethane resin layer, and a 2nd polyurethane resin layer is formed.

Since the said subject and hardening | curing agent are the same as those used at the time of the said 1st polyurethane resin layer construction, the description is abbreviate | omitted. However, in the second polyurethane resin layer, the curing agent is used in an amount greater than that of the first polyurethane resin layer in order to increase the hardness of the first polyurethane resin layer, and in addition, the second polyurethane resin may be used by using a chain extender or the like. It is advisable to adjust the Shore A hardness of the strata in the range of 45 to 65.

At this time, the resin composition is applied so that the second polyurethane resin layer formed finally has a thickness of 1 to 8 mm.

Lastly, the second polyurethane resin layer includes a polyisocyanate having at least two isocyanate groups per molecule and a polyol compound having at least two hydroxyl groups per molecule, and two or more hydroxyl groups per molecule. A hardening agent containing a polyol compound, a thixotropic reinforcing filler, or a composition in which an elastic polymer chip is mixed thereon is applied to form an uneven layer.

Here, although the formation of the uneven layer by using the elastic polymer chip is described, various irregularities forming method such as applying a thixotropic resin, or applying an elastic chip-containing resin in which the elastic polymer chip and the resin component are pre-mixed. It is apparent to those skilled in the art that this can be used.

Since the said subject and hardening | curing agent are the same as those used at the time of the said 1st polyurethane resin layer construction, the description is abbreviate | omitted.

The thixotropic reinforcing filler may have a flow preventing effect, and specific examples thereof may include fumed silica, calcium carbonate, surface-coated calcium carbonate, talc, carbon black, or titanium dioxide. The content is 10 to 50 parts by weight based on 100 parts by weight of the composition forming the uneven layer is good for improving the thixotropy and flowability.

The elastic polymer chip serves to form protrusions on the surface of the second polyurethane resin layer.

It is preferable that the average diameter of the elastic polymer chip is 1 to 10 mm, and when the average diameter is less than 1 mm, there is a problem that the surface protrusion is too low, and when the average diameter exceeds 10 mm, the problem is that the surface protrusion is too high. have.

The elastic polymer chip may have a suitable density of protrusions contained in 10 to 50 parts by weight based on 100 parts by weight of the composition forming the uneven layer. In particular, as the elastomeric polymer chip, it is more preferable to use a urethane chip pulverized in an average of about 2 to 5 mm in size by using a pulverizer after curing the composition for forming the semi-hard urethane.

The construction of the concave-convex layer made of the above components may be carried out by first mixing a main body, a curing agent, a thixotropic reinforcing filler, and an elastic polymer chip, and then applying it on the second polyurethane resin layer. At this time, the mixing order of the components are not specified, but in order to stabilize the progress of the urethane formation reaction, the curing agent and the thixotropic reinforcing filler are first uniformly mixed by using an agitator or the like, and then the elastic polymer chips are uniformly mixed therein. Good to do.

It is good to apply the last formed uneven | corrugated layer so that it may become thickness of 1-5 mm.

The coating method for forming the first polyurethane polyurethane resin layer, the second polyurethane polyurethane resin layer, and the concave-convex layer as described above is not particularly limited, and may be carried out by a conventional method such as coating with a roll or spray coating. Of course.

Construction method of the urethane sheet of the present invention carried out in the same step as described above may further form a top coating polyurethane resin layer on the uneven layer.

The top coating polyurethane resin layer is carried out to prevent slipping of the finally formed urethane sheet, and can be constructed by applying a non-slip filler such as silica, silica sand, sawdust, or ocher.

At this time, the top coating polyurethane resin layer is preferably constructed as thin as 0.2 to 0.5 mm so that the surface protrusion forming effect of the concave-convex layer formed on the lower portion does not disappear due to the top coating polyurethane resin layer.

In addition, the present invention provides a urethane sheet system formed by construction in the same manner as described above, Figure 1 shows a cross-sectional view of the urethane sheet system of the present invention.

1, the urethane sheet system includes a first polyurethane polyurethane resin layer 1, a second polyurethane polyurethane resin layer 3 formed on the first polyurethane polyurethane resin layer 1; And an uneven layer 5 formed on the second polyurethane polyurethane resin layer 3 and having unevenness formed thereon.

The first polyurethane polyurethane resin layer (1) inside the hollow filler is included to increase the absorption rate for a certain impact, to improve the vertical displacement of the resin layer by the impact to reduce the vertical displacement. In addition, the hardened body of the first polyurethane resin layer (1) includes a hollow filler to minimize impact on the body by minimizing the impact on the body, to protect the player from injury, and to maintain the vertical displacement at a constant level, thereby reducing the record performance. Can contribute to.

Basically, the first polyurethane resin layer is preferably to be a soft layer through the content control of the resin composition.

The second polyurethane resin layer 3 is formed on the first polyurethane resin layer 1, and has a higher hardness (semi-hard) than the first polyurethane resin layer 1, and the thickness thereof is also the first. It is remarkably thin compared with the polyurethane resin layer 1.

In addition, the uneven layer 5 is formed in a predetermined thickness on the upper portion of the second polyurethane resin layer 3, the uneven surface is formed on the surface can prevent the slip.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example  1. Manufacturing urethane resin composition

(Urethane Prepolymer Synthesis)

400 parts by weight of polypropylene glycol diol having a molecular weight of 2,000 and 400 parts by weight of polypropylene glycol triol having a molecular weight of 3,000 are added and mixed to dehydrate the water to be 0.1% or less, and then 200 parts by weight of isocyanate is added to the reaction temperature. The reaction was continued for 5 hours or more while maintaining a temperature of 5 ° C. to synthesize a urethane prepolymer having an isocyanate content of 5%.

(Manufacture of hardener)

30 g of 3,3'-dichloro-4,4'-diaminodiphenylmethane as a crosslinking agent, 220 g of polypropylene glycol diol with a polyol molecular weight of 3,000, 120 g of polypropylene glycol triol with a molecular weight of 4,000, di as a plasticizer The curing agent was uniformly mixed with 100 g of octylphthalate, 10 g of pibiate as a catalyst, 470 g of calcium carbonate as a filler filler, 20 g of iron oxide red as a pigment, and 60 g of hollow glass filler (manufactured by 3M Corporation). Prepared.

(Manufacture of urethane resin composition)

The urethane prepolymer 300 g and the curing agent 900 g prepared above were put in a reaction vessel, stirred at room temperature for 30 minutes, and cured to prepare a urethane resin composition.

Example  2

The manufacturing method of the curing agent of Example 1 was carried out in the same manner as in Example 1, except that a hollow plastic filler (manufactured by Masato, Japan) was used instead of the hollow glass filler.

Example  3

When preparing the curing agent of Example 1 was carried out in the same manner as in Example 1 except for using volcanic rock pearl rock prepared by expanding the moisture contained in the rock by applying heat of 1,000 ℃ or more in place of the hollow glass filler.

Comparative example  One

When preparing the curing agent of Example 1 was carried out in the same manner as in Example 1 except for containing the foaming agent water and foam stabilizer in place of the hollow glass filler.

Comparative example  2

The preparation of the curing agent of Example 1 was carried out in the same manner as in Example 1 except for containing calcium carbonate in place of the hollow glass filler.

Example  4. Urethane Sheet Construction

A glass plate 50 cm wide x 50 cm long and 1 cm thick was prepared at the site to be constructed, and a release agent was applied.

Then, after heating for 3 days by applying the exothermic resin composition prepared in Example 1 on the upper portion of the glass plate in an external environment at room temperature, the final cured first polyurethane resin layer was to have a thickness of 10 mm.

Subsequently, the resin composition which mix | blended in the composition ratio shown in following Table 1 was apply | coated on the said 1st polyurethane resin layer upper part, and it was made so that the hardened 2nd polyurethane resin layer might be 2-3 mm thick.

Finally, a resin composition blended in the composition ratio as shown in Table 2 was applied to the second polyurethane resin layer, so that the cured uneven layer became 2 to 3 mm (FIG. 1).

Example  5 to 6 and Comparative example  3 to 4

The same process as in Example 4 was performed except that the resin compositions of Examples 2 to 3 and Comparative Examples 1 and 2 were used to form the first polyurethane resin layer in Example 4.

Example  7

Top coating was further performed with silica to prevent slipping on the uneven layer formed in Example 4 above.

As a result of the construction of Examples 4 to 7 and Comparative Examples 3 to 4, Examples 4 to 7 of the present invention using the urethane resin composition including the hollow filler according to the present invention is a decrease in the foaming rate or uneven foaming according to the construction environment It was possible to construct easily without problems, and in the case of Comparative Example 3, the foaming rate was changed according to environmental conditions at room temperature by foaming and simultaneously foaming using a resin composition containing water as a blowing agent. It was confirmed that the uniform foaming did not occur.

In addition, the impact absorption and the vertical displacement of the resin was measured using the urethane sheets constructed in Examples 4 to 7 and Comparative Example 3, and the results are shown in Table 4 below. At this time, the impact absorption rate and the vertical displacement of the resin were carried out according to the test method specified in the Performance Specification for Synthetic Surfaced Athletics Tracks published by the IAAF.

As shown in Table 3, Examples 4 to 7 according to the present invention was confirmed that the shock absorption is excellent compared to Comparative Examples 2 to 3. In addition, Examples 4 to 7 it was confirmed that the vertical displacement of the resin was improved by including the hollow filler inside the urethane sheet, showing a small value of the vertical displacement.

According to the present invention, it is easy to work without being influenced by external conditions when working at room temperature or in an external environment, and has excellent workability, and has a low specific gravity compared to cured urethane sheets. Including a filler can improve the absorption rate for a certain impact. In addition, the hollow filler contained therein improves the vertical displacement of the resin, the absorption of shock is good, but the vertical displacement is small, excellent movement characteristics, there is an effect that can be widely used as a ground track or sports facility flooring.

Although only described in detail with respect to the described embodiments of the present invention, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, it is natural that such variations and modifications belong to the appended claims. .

Claims (12)

A subject comprising a polyisocyanate having at least two isocyanate groups per molecule and a polyol compound having at least two hydroxyl groups per molecule; A resin composition for urethane sheets comprising a polyol compound having two or more hydroxyl groups per molecule and a curing agent comprising a hollow filler. The method of claim 1, The urethane prepolymer is prepared by reacting a polyisocyanate having at least two isocyanate groups per molecule and a polyol having at least two hydroxyl groups per molecule at an equivalent ratio (NCO / OH) of 1.2 to 5.0. . The method of claim 2, The said polyol is at least 1 sort (s) of polyol chosen from the group which consists of polypropylene glycol, polytetramethylglycol, and polycaprolactone diol, The resin composition for urethane sheets characterized by the above-mentioned. The method of claim 1, The hollow filler is at least one selected from the group consisting of hollow glass fillers made of glass, hollow plastic films made of plastic, and hollow rocks made by expanding moisture contained in the rock by applying at least 1,000 ° C. heat; It is a species, The resin composition for urethane sheets. The method of claim 1, The hollow filler is a urethane sheet resin composition, characterized in that contained in the curing agent in 0.5 to 40% by weight. Planarizing and repairing the floor surface to be constructed; Applying a primer resin on the bottom surface to form a primer layer; Applying a first polyurethane resin composition comprising a hollow filler on the primer layer to form a soft first polyurethane resin layer; Coating a second polyurethane resin composition on the first polyurethane resin layer to form a semi-rigid second polyurethane resin layer; And Construction method of the urethane sheet comprising the step of forming an uneven layer on the second polyurethane resin layer. The method of claim 6, The forming of the uneven layer may include applying an elastic chip-containing resin layer on the second polyurethane resin layer. The method of claim 6, The method of constructing a urethane sheet, characterized in that it further comprises the step of top coating the formed concave-convex layer. A first polyurethane resin layer comprising a hollow filler; A second polyurethane resin layer formed on the first polyurethane resin layer; And A urethane sheet comprising an uneven layer formed on the second polyurethane resin layer. The method of claim 9, The first polyurethane resin layer is a urethane sheet, characterized in that the soft layer. The method of claim 9, The second polyurethane resin layer is a urethane sheet, characterized in that the semi-hard layer. The method of claim 9, The thickness of a said 1st polyurethane resin layer is 5-15 mm, the thickness of a 2nd polyurethane resin layer is 1-8 mm, and the thickness of the said uneven | corrugated layer is 1-5 mm, The urethane sheet characterized by the above-mentioned.

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