WO2008140183A1

WO2008140183A1 - Flooring having transfer-printed layer by dual cure system and process for manufacturing the same

Info

Publication number: WO2008140183A1
Application number: PCT/KR2008/001360
Authority: WO
Inventors: Jong-Bum Kim
Original assignee: Lg Chem, Ltd.
Priority date: 2007-05-15
Filing date: 2008-03-11
Publication date: 2008-11-20
Also published as: KR100886318B1; KR20080100970A

Abstract

A flooring having a transfer-printed layer by a dual cure system and a process for manufacturing the same are disclosed. The flooring comprises a base board, a resin layer (hereinafter, referred to as a primer layer) formed on the base board, and a transfer-printed layer formed on the primer layer, wherein the primer layer is dual cured by heat and light. As a result, the flooring with reinforced adhesion between the base layer and the transfer-printed layer, and with various and detailed surface images is provided.

Description

FLOORING HAVING TRANSFER-PRINTED LAYER BY DUAL CURE SYSTEM AND PROCESS FOR MANUFACTURING THE SAME

Technical Field

The present invention relates to a flooring having a transfer-printed layer by using a dual cure system and a process for manufacturing the same, and more particularly, to a flooring comprising a base board, a primer layer formed on the base board, and a transfer-printed layer formed on the primer layer, wherein the primer layer is dual cured by heat and light, and a process for manufacturing the flooring.

Background Art

In a conventional flooring having a transfer-printed layer, a primer layer is formed on a base layer through curing only by heat to carry out transfer printing. Therefore, when a sufficient heat is not applied for curing, there are disadvantages that the transfer-printed layer is not properly formed or the adhesion with the base layer is deteriorated. On the other hand, when an excessive temperature or time for heating is applied to increase curability, there is a concern that the ink or resin in the transfer-printed layer is deformed so as to reduce printing quality.

In most heat-curing reaction, an excellent curability is not achieved in short period of time, but it increases as time passes. Thus, in the beginning of the heat-curing, there are disadvantages that the adhesion between the base layer and the printed layer is deteriorated and poor surface physical properties, such as indentation resistance, scratch resistance, and pencil hardness, are obtained due to low durability.

Disclosure of Invention

Technical Problem

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a flooring with excellent basic surface physical properties, such as an indentation resistance, scratch resistance and pencil hardness, by forming a transfer-printed layer using a dual cure system so as to solve the problems that the conventional floorings have, such as exfoliation of the printed layer and base layer.

It is another object of the present invention to provide a process for manufacturing the flooring with improved workability and productivity, which comprises forming a base layer, a primer layer, and a transfer-printed layer under respective optimum conditions.

Technical Solution

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a flooring comprising a base layer, a primer layer, a transfer-printed layer and a surface coating layer laminated in this order from the bottom. The base layer may be made of any one of inorganic-based, synthetic resin-based or wood-based boards.

Examples of the inorganic-based boards include magnesium boards, silicon boards, plaster boards, and cellulose fiber reinforced cement boards (CRC). Examples of the synthetic resin-based boards include poly vinyl chloride

(PVC), poly carbonate (PC), poly ethylene (PE), poly propylene (PP), poly ethylene terephthalate (PET), modified poly ethylene terephthalate glycol (PETG), poly cyclohexylene dimethylene terephthalate glycol (PCTG), acrylonitrile butadiene styrene (ABS), and acryl boards. Examples of the wood-based boards include water-resistant plywoods, medium density fiberboards (MDFs), high-density fiberboards (HDFs), particle boards, kenaf boards, and resin- wood meal mixed boards.

Among the above-mentioned boards, the preferable board is HDFs. HDFs are much harder and highly resistant to water than the particle boards. Therefore, HDFs can improve the impact strength and water-resistance of the flooring. Moreover, since HDFs can be manufactured on a large scale, there is an advantage in the viewpoint of cost effectiveness compared with the water- resistant plywoods or resin-wood meal mixed boards. Especially, The HDF can be easily processed so as to have a very smooth and soft surface. Meanwhile, these materials realize snap type or angle type joint effect. In addition, the flooring of the present invention elastically responds to expansion and shrinkage, thus avoiding loosening or damage to bonding of the floorings.

It is preferred that the primer layer is made of a solventless type resin taking into consideration the prevention of environmental pollution and improvement of productivity and workability. Examples of the resins include epoxy resins, polyurethane resins, poly-isocyanate resins, polyester resins, acrylate resins, ethylene-vinyl acetate copolymers, polyamide resins, melamine resins, synthetic rubbers, and polyvinyl alcohol resins. Epoxy acrylate resins, urethane acrylate resins, polyester acrylate resins, and unsaturated polyester resins are more preferred. Further, urethane acrylate resins are particularly preferred.

It is preferable that the primer layer contains urethane acrylate resins (30 to 70 % by weight) as a resin. 1 to 10% by weight of a curing agent including a heat-curing agent and a light-curing agent is preferably added to the resin. It is preferable that putty is coated before forming the primer layer to cover the background pattern of the base layer and increase the printing quality.

Examples of the heat-curing agent include benzoic peroxide (BPO), di-t- butyl peroxide (DTBPO), cumene hydroperoxide (CHPO), t-butyl peroxy-2- ethylhexanoate, t-butyl peroxy benzoate, azobis dimethyl valeronitrile (V-65), and azobis isobutyro nitrile (AIBN). Examples of the light-curing agent include benzyl dimethyl ketal, 1- hydroxy cyclohexyl acetophenone, α-dimethoxy-α-hydroxy acetophenone, 2,4,6- trimethyl benzoyl diphenyl phosphine oxide, bisacryl phosphine oxide (BAPO), and 2,4-diethyl thioxanthone.

The primer layer serves to enhance the adhesion between the base layer and the transfer-printed layer, and is effective in enhancing the waterproof property of the finished product. Waterproof property is an important requirement for floorings. Moreover, the dual cure system increases hardness, thereby definitely enhancing the basic surface physical properties of the flooring such as the indentation resistance, scratch resistance, and pencil hardness. The transfer-printed layer is made using a general-purpose polyethylene terephthalate (PET) transfer paper.

The surface coating layer is formed to protect the transfer-printed layer. Examples of the surface coating layer include synthetic resins such as PVC, PC, PE, PP, PET, PETG, PCTG, ABS, SBS, PU, and acrylate, or an ultraviolet (UV) curable coating agent generally used for the surface coating layer in the flooring. It is preferable that the ultraviolet (UV) curable coating agent is used in the present invention.

The surface coating layer consists of a surface primer layer, an under coating layer, an intermediate coating layer and a top coating layer. An inorganic material selected from ceramics, glass chops, clays, and silica is added to the under coating layer and the top coating layer to greatly improve the surface physical properties, such as scratch resistance, thereby preventing the surface of the flooring from damage, e.g., indentation, breakage and scratch, caused by a heavy or sharp object. A backing layer may be formed in the consideration of the flooring structural stability. The backing layer is formed by coating the bottom surface of the base layer with a paper, a metal foil, an ultraviolet (UV) curable surface- treating agent, a heat curable surface-treating agent, a synthetic resin, wax, a silicone-based water-repellent agent, a silicone-based waterproofing agent, or the like. The formation of the backing layer on the bottom surface of the base layer can solve the problem of deformation caused by a variation in humidity.

The flooring of the present invention is processed to have a tongue and groove (T & G) shape, a click system or a linking structure for a connector so that it can be joined to another flooring, which is the same one as the flooring of the present invention.

In accordance with another aspect of the present invention, there is provided a process for manufacturing a flooring, comprising: preparing a transfer printing paper and a base layer; forming a backing layer under the base layer; forming a primer layer on the base layer; performing transfer printing on the surface of the primer layer through dual curing of heat and light to form a transfer- printed layer; forming a surface coating layer consisting of a surface primer layer, an under coating layer, an intermediate coating layer and a top coating layer on the transfer-printed layer; and cutting and shaping the resulting structure.

In the step of forming a primer layer on the base layer, it is preferable that the base layer is coated with a solventless type resin to a predetermined thickness, and the coated structure is passed through an oven at 60 to 160°C for 5 seconds to 5 minutes.

The dual curing is performed simultaneously with the transfer printing, and the transfer printing may be performed in the order of heat-curing and then light-curing, or light-curing and then heat-curing. Taking into consideration the prevention of the deformation and improvement of the productivity of the final product, it is preferred to perform the heat-curing using a roll under 0.2 to 3.0 MPa at 60 to 130°C and the light-curing under 100 to 600 mJ/cm² for 5 to 30 seconds.

Description of Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. l is a cross-sectional view of a flooring according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a flooring according to another embodiment of the present invention; FIG. 3 is a process chart illustrating a process for manufacturing a flooring according to an embodiment of the present invention; and

FIG. 4 is a top view of a finished product consisting of two floorings of the present invention, both of which have a tongue and groove (T & G) shape.

Best Mode

The present invention will be described in a greater detail with reference to the accompanying drawing.

FIG. 1 is a cross-sectional view of a flooring according to an embodiment of the present invention. The flooring comprises a surface coating layer 10, a transfer-printed layer 20, a primer layer 30, a base layer 40, and a backing layer 50 laminated in this order from the top.

The formation of the surface coating layer 10 is achieved by UV coating the surface of the transfer-printed layer 20. The surface coating layer generally consists of a surface primer layer, an under coating layer, an intermediate coating layer and a top coating layer, which are sequentially formed on the transfer- printed layer 20.

To enhance the impact resistance and indentation resistance of the flooring surface, the surface primer layer is formed by UV curing of monomers and oligomers having a relatively low molecular weight. This UV curing facilitates the coating of the monomers and oligomers and is preferably carried out for 10 seconds to 4 minutes.

An inorganic material, such as a glass chop, may be added to the under coating layer to enhance the surface physical properties of the flooring. At this time, the inorganic material is preferably added in an amount of 0.1 to 10% by weight.

A nano-sized inorganic material or silica may be added to the top coating layer to enhance the scratch resistance and wear resistance of the flooring surface. At this time, the nano-sized inorganic material or silica is preferably added in an amount of 0.1 to 10% by weight.

The transfer-printed layer 20 is formed by using transfer printing techniques in order to make the most of natural beauty of wood. Depending on the needs of consumers, patterns of all species of trees, including oak, birch, cherry, maple and walnut, may be faithfully and freely realized. For the transfer printing, general-purpose PET transfer printing papers may be used.

The primer layer 30 serves to cover the background fiber pattern of the high-density fiberboard and enhance the adhesion between the base layer 40 and the transfer-printed layer 20. The primer layer is preferably made of a solventless type resin in consideration of the environment. Examples of the resins include epoxy resins, polyurethane resins, poly-isocyanate resins, polyester resins, acrylate resins, ethylene-vinyl acetate copolymers, polyamide resins, melamine resins, synthetic rubbers, and polyvinyl alcohol resins. Epoxy acrylate resins, urethane acrylate resins, polyester acrylate resins, and unsaturated polyester resins are more preferred. Further, urethane acrylate resins are particularly preferred.

As regulations restricting the use of volatile organic compounds (VOCs) are increasingly stringent and sick house syndrome is highlighted as a serious problem, general organic solvent type resins that are widely used in the art cannot be used to manufacture the flooring of the present invention. Instead, a solventless type resin is used in the present invention to reduce the amount of formaldehyde released to almost zero and prevent the occurrence of volatile organic solvents.

The base layer 40 may be made using inorganic-based, synthetic resin- based, or wood-based boards. Particularly, a high-density fiberboard (HDF) is preferred. In the case of HDF, it is preferable the HDF has a specific weight of 0.85 to 1.1 g/cm³. The high-density fϊberboard is much harder, exhibits better water resistance and dimensional stability, and has higher mechanical strength than a medium-density fiberboard (MDF) or a particle board (PB). Accordingly, when the high-density fiberboard is used to form the base layer, the dimensional stability, impact strength and moisture resistance of the flooring can be greatly improved.

The high-density fiberboard is low priced and exhibits good wear resistance and impact resistance, compared to a water-resistant plywood. In addition, the high-density fiberboard is free of defects, such as knots, and exhibits uniform physical properties because fibers are orderly arranged in every direction. The HDF can be easily processed so as to have a very smooth and soft surface. Accordingly, the surface of the flooring using the HDF gives a feeling of smoothness and softness. The flooring of the present invention is processed to have a mechanical fixing system, such as a click construction structure or a linking structure for a connector so that it can be integrally joined to another flooring, which is the same one as the flooring of the present invention, in a vertical or horizontal direction. In addition, the flooring of the present invention elastically responds to expansion and shrinkage, thus avoiding loosening or damage to bonding of the floorings. The backing layer 50 is formed by coating the bottom surface of the high- density fiberboard layer 40 with a paper, a metal foil, a UV curable surface- treating agent, a heat curable surface-treating agent, a synthetic resins, wax, silicone-based water-repellent agents and silicone-based waterproofing agents. It is preferable that the backing layer is formed using the same UV curable coating agent as the surface coating layer for structural symmetry of the final product.

Taking into consideration the ease of assembly, the flooring of the present invention is preferably processed into a general tongue and groove (T & G) shape. For example, the flooring of the present invention may be processed to have a mechanical fixing system, such as a click construction structure or a linking structure for a connector so that it can be integrally joined to another flooring, which is the same one as the flooring of the present invention, in a vertical or horizontal direction.

FIG. 2 is a cross-sectional view of a flooring according to another embodiment of the present invention. The flooring comprises a surface coating layer 10, a transfer-printed layer 20, a primer layer 30, a putty layer 35, a base layer 40, and a backing layer 50 laminated in this order from the top.

The putty layer 35 is formed by coating putty on the base layer before forming the primer layer 30 to cover the background pattern of the base layer and increase the printing quality of the transfer-printed layer 20. The putty layer 35 consists of a resin, such as aqueous acrylate, and 10 to 40% by weight of titanium dioxide.

FIG. 3 is a process chart illustrating a process for manufacturing a flooring according to an embodiment of the present invention. The process comprises forming a backing layer 50 under a base layer 40; forming a primer layer 30 on the base layer 40; performing transfer printing on the surface of the primer layer 30 through dual curing of heat and light to form a transfer-printed layer 20; forming a surface coating layer 10 on the transfer-printed layer 20; and cutting and shaping the resulting structure.

In the step of forming a primer layer 30, the primer layer 30 is preferably pretreated in an oven at 60 to 16O⁰C for 5 seconds to 5 minutes. An excessively high temperature causes severe deformation of the base layer 40. Meanwhile, too low temperature may cause poor adhesion between the transfer-printed layer 20 and the base layer 40, because penetration of the primer layer 30 to the base layer 40 by the heat movement becomes incomplete. Even when the two layers are adhered to each other, bad surface leveling may be caused at too low temperature.

In the step of forming a transfer-printed layer 20, transfer printing is preferably carried out by performing heat-curing using a roll under 0.2 to 3.0 MPa at 60 to 130°C and light-curing under 100 to 600 mJ/cm² for 5 to 30 seconds. The transfer-printed layer may be ruptured at too high a printing pressure. Meanwhile, poor printing may be caused at too low a printing pressure. Moreover, too low a light energy may cause no curing. Meanwhile, too high a light energy may result in rupture of the transfer-printed layer.

In the step of forming a surface coating layer 10, the surface coating layer 10 is formed on the transfer-printed layer 20. The surface coating is performed by UV curing, which is a technique employed to manufacture general floorings. Specifically, a surface primer layer, an under coating layer, an intermediate coating layer and a top coating layer are sequentially formed on the transfer-printed layer 20, followed by UV curing. The surface coating layer 10 is made of a UV curable or heat curable synthetic resin essentially composed of urethane acrylate. To achieve desired surface physical properties, such as superior resistance to indentation and impact, the surface coating layer 10 is made of at least one resin selected from the group consisting of epoxy resins, polyamide resins, urea resins and acrylate resins. Particularly preferred is an epoxy resin.

To enhance the impact resistance and indentation resistance of the flooring surface, the surface primer layer is formed by curing oil-phase or aqueous monomers and oligomers having a relatively low molecular weight at 80 to 15O⁰C. This UV curing facilitates coating of the monomer and oligomer layer on the printed layer and is preferably carried out for 10 seconds to 4 minutes.

An inorganic material selected from ceramics, and glass chops may be added to the under coating layer. The inorganic material is preferably added in an amount of 0.1 to 10% by weight. At least one inorganic or nano-sized inorganic material selected from clays, ceramics and silica may be added to the top coating layer to improve the scratch resistance of the flooring surface. It is preferred to sufficiently disperse 0.1 to 10 parts by weight of the inorganic material in 100 parts by weight of a urethane acrylate resin and add the dispersion to the top coating layer so as not to affect the transparency of the top coating layer. FIG. 4 is a top view of a finished product consisting of two floorings of the present invention, both of which have a tongue and groove (T & G) shape. As shown in FlG. 4, four sides of the finished product in both length and width directions are processed into two tongue sites 70 and two groove sites 60. Alternatively, the flooring of the present invention may be processed to have a mechanical fixing system, such as a click system or a system for a connector, so that it can be integrally joined to another flooring, which is the same one as the flooring of the present invention, in a vertical or horizontal direction.

Hereinafter, preferred embodiments of the present invention will be explained. However, these embodiments are given for the purpose of illustration and are not intended to limit the present invention.

[Example 1]

A backing layer 50 was firstly formed under a base layer 40 for structural stability. A primer layer 30 was formed on the base layer 40 and a transfer- printed layer 20 was formed thereon. A surface coating layer 10 was formed on the transfer-printed layer 20, followed by cutting and processing into a tongue 60 and groove 70 shapes to complete manufacture of the flooring shown in FIG. 1.

Specifically, the primer layer 30 was formed using a solventless type urethane acrylate resin. As a curing agent, a heat-curing agent (t-butyl peroxy-2- ethylhexanoate) and a light-curing agent (bisacryl phosphine oxide) were added in an amount of 3% by weight based on the resin. After forming the primer layer 30, the coated structure was pretreated in an oven at 12O⁰C for 10 seconds. The transfer-printed layer 20 was formed by heat-curing using a roll under heat (100°C) and pressure (0.7 MPa) and light-curing under energy (500 mJ/cm ) for 10 seconds. A general -purpose PET paper was used as a transfer paper to transfer-print a wood-like pattern. The base layer 40 was made using an HDF. The HDF used herein had a density of 900 kg/m³ or more, water content of 4.0 to 7.0% and a thickness of 7.5 to 8.0 mm.

A surface primer layer, an under coating layer and an intermediate coating layer were sequentially formed on the transfer-printed layer 20. 5% by weight of a ceramic was added to the under coating layer. The resulting structure was cut to a width of 85 to 95 mm and a length of 850 to 950 mm using a tenoner, and the sides were processed to have a T & G shape. A top coating layer containing 5% by weight of a nano-sized inorganic material was formed on the intermediate coating layer, completing manufacture of a final flooring.

[Example 2]

A flooring was manufactured in the same manner as in Example 1, except that a white putty layer 35 composed of aqueous acrylate containing 40% by weight of titanium dioxide was formed under the primer layer 30 before forming the primer layer 30 to cover the background pattern of the base layer.

[Comparative Example 1]

Using HDF as a base, a heat-curable primer layer was formed on the HDF and transfer printing was performed under a temperature of 100°C and a pressure of 0.7 MPa for 1 minute. Then, a surface coating layer was formed in the same manner as in Example 1 to manufacture a heat curable transfer flooring.

[Comparative Example 2] Using a water-resistant plywood as a base, a natural wood pattern was laminated on the base layer and UV curable surface coating was performed to manufacture a plywood flooring.

[Experimental Example]

The physical properties of the floorings manufactured in Examples 1 and 2 were compared with those of the floorings manufactured in Comparative Examples 1 and 2. The results are shown in Table 1.

[Table 1]

The indentation resistance of the floorings was evaluated by dropping a flat-head screwdriver weighing HO g onto the surfaces (inclined at an angle of 45 degrees relative to the horizontal plane) of the floorings and measuring a height at which surface indentation was observed. As is apparent from the data shown in Table 1 , the surfaces of the plywood flooring (Comparative Example 2) and the heat curable transfer flooring (Comparative Example 1) were indented when the flat-head screwdriver was dropped from a height of 20 cm and 10 cm, respectively, while the surfaces of the floorings (Examples 1 and 2) were indented when the flat-head screwdriver was dropped from a height of 30 cm.

The breakage resistance of the floorings was evaluated by dropping an iron ball having a diameter of 3 cm and a weight of 228g onto the surfaces of the floorings and measuring a height at which surface breakage was observed. As can be seen from the data shown in Table 1, the surfaces of the plywood flooring (Comparative Example 2) and the heat curable transfer flooring (Comparative Example 1) were broken when the iron ball was dropped from heights of 20 cm and 40 cm, respectively, while the surfaces of the floorings according to the present invention (Examples 1 and 2) were broken when the iron ball was dropped from a height of 80 cm and 70 cm, respectively.

The dimensional stability of the floorings was evaluated by allowing the floorings to stand in an oven at 80°C and a water bath at room temperature for 24 hours and measuring dimensional variations in length (L) and width (W). According to the test results of Table 1 , the dimensional stability of the floorings according to the present invention was similar when compared to that of the plywood flooring, but was excellent when compared to that of the conventional heat curable transfer flooring.

The scratch resistance of the floorings was evaluated by measuring the degree of surface scratching under a load (N) using a Clemens-type scratch hardness tester in accordance with the procedure described in Paragraph 3.15 of the standard method KS M3332. From the test results of Table 1, it could be confirmed that the scratch resistance (6 N and 5 N) of the floorings according to the present invention was superior to that (2.0 N) of the plywood flooring and that (4.0 N) of the heat curable transfer flooring.

The thickness expansion rate of the floorings after water absorption was evaluated by dipping the floorings in water at room temperature for 24 hours (U type, Paragraph 6.9 of KS F32009) and water at 70°C for 2 hours (M type), and measuring the variation in the thickness of the floorings. As is evident from the test results of Table 1, the thickness expansion rates of the floorings were similar when compared to that of the plywood flooring, but the M type thickness expansion rates (Example 1 : 3% and Example 2: 4%) of the floorings according to the present invention were excellent than the thickness expansion rate (6%) of the heat curable transfer flooring.

The warp stability of the floorings (Examples 1 and 2) was compared with that of the floorings (Comparative Examples 1 and 2). The results are shown in Table 2. Table 2

The warp stability of the floorings was evaluated by allowing the samples to stand in an oven at 80 ± 2°C for 24 hours and measuring the number of curls and domes. As a result, the warp stability in the width direction of the floorings according to the present invention was most excellent when compared to the plywood flooring and the heat curable transfer flooring. In addition, the warp stability (Example 1 : 0.87 mm and Example 2: 0.91 mm) in the lengthwise direction of the floorings according to the present invention was much better than that (1.67 mm) of the conventional heat curable transfer flooring (Comparative Example 1) or that (4.96 mm) of the plywood flooring (Comparative Example 2).

From these experimental results, it could be presumed that the floorings of the present invention showed superior surface physical properties, e.g., superior resistance to indentation and breakage caused by a heavy or sharp object, as compared to the plywood flooring and the heat curable transfer flooring, and excellent physical properties with less structural deformation.

Industrial Applicability

The present invention relates to a flooring having a transfer-printed layer by using a dual cure system and a process for manufacturing the same. The flooring comprises a base board, a primer layer formed on the base board, and a transfer-printed layer formed on the primer layer, wherein the primer layer is dual cured by heat and light. As a result, the flooring with reinforced adhesion between the base layer and the transfer-printed layer, and with various and detailed surface images is provided.

The flooring of the present invention uses a dual curable resin as the primer layer. This solved the problems, such as exfoliation between the base layer and the transfer-printed layer, which conventional floorings had. Moreover, the dual curing system increased curability such that the basic surface physical properties, such as indentation resistance, scratch resistance, and pencil hardness, of the flooring improved greatly. In addition, since the flooring is dual cured with heat and light, the factors for generating defects during the production is reduced, and the productivity and workability is improved.

Further, the flooring of the present invention added an inorganic material selected from glass chops, ceramic, clay, or silica, to the surface coating layer so that the surface physical properties, such as indentation resistance, scratch resistance, are greatly improved. Moreover, by forming the backing layer using the same UV curable coating agent as the surface coating layer under the base layer, the structural stability was ensured, thereby having excellent dimensional variation rate or warp stability, such as a product flexibility. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A flooring comprising: a base layer; a primer layer; and a printed layer formed by dual curing including heat-curing and light- curing.

2. The flooring according to claim 1, wherein the primer layer comprises a solventless resin, a heat-curing agent, and a light-curing agent.

3. The flooring according to claim 2, wherein the solventless resin is at least one selected from epoxy resins, polyurethane resins, poly-isocyanate resins, polyester resins, acrylate resins, ethylene-vinyl acetate copolymers, polyamide resins, melamine resins, synthetic rubbers, and polyvinyl alcohol resins.

4. The flooring according to claim 2, wherein the primer layer comprises 30 to 70% by weight of a solventless resin and 1 to 10% by weight of a curing agent consisting of a heat-curing agent and a light-curing agent.

5. The flooring according to claim 1, further comprising a putty layer formed between the base layer and the primer layer.

6. The flooring according to claim 5, wherein the putty layer comprises 10 to 40% by weight of titanium dioxide.

7. The flooring according to claim 1, wherein the printed layer is a transfer-printed layer formed by transfer printing of a general-purpose polyethylene terephthalate (PET) transfer paper.

8. The flooring according to claim 7, wherein the transfer printing and the dual curing is performed at the same time.

9. The flooring according to claim 1, further comprising a backing layer formed under the base layer, wherein the backing layer is made of at least one selected from a paper, a metal foil, an ultraviolet (UV) curable surface-treating agent, a heat curable surface-treating agent, a synthetic resin, wax, a silicone- based water-repellent agent, and a silicone-based waterproofing agent.

10. The flooring according to claim 1, further comprising a surface coating layer formed on the transfer-printed layer, wherein the surface coating layer comprises an under coating layer, an intermediate coating layer and a top coating layer.

11. The flooring according to claim 10, wherein each of the under coating layer and the top coating layer comprises an inorganic material, which is at least one selected from ceramic, glass chops, clay, and silica.

12. The flooring according to claim 1, wherein the flooring is processed to have a tongue and groove (T & G) shape, a click system or a linking structure for a connector.

13. A process for manufacturing a flooring comprising: forming a backing layer under a base layer; forming a primer layer including a heat-curing agent and light-curing agent on the base layer; forming a transfer-printed layer on the primer layer by carrying out transfer printing through dual curing including heat-curing and light-curing; forming a surface coating layer on the transfer-printed layer; and cutting and shaping the resulting structure.

14. The process according to claim 13, wherein the primer layer is formed by coating the primer layer on the base layer, and pre-treating the primer layer in an oven at 60 to 16O⁰C for 5 seconds to 5 minutes.

15. The process according to claim 13, wherein the transfer-printed layer is formed simultaneously with the dual curing, in which the heat-curing is performed using a roll at a temperature of 60 to 13O⁰C and under a pressure of 0.2 to 0.3 MPa and the light-curing is performed under a light amount of 100 to 6 mJ/cm² for 5 to 30 seconds.