JP7253009B2 - tread - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a tread plate used for stairs, and more particularly to a tread plate on which grooves are formed on the tread surface for anti-slip purposes and a pattern such as wood grain is printed by inkjet printing.

BACKGROUND ART As a staircase installed in a building such as a house, a staircase having at least a plurality of treads arranged in a staircase pattern and side plates for fixing the treads on the left and right sides is known. Specifically, in a staircase, a required number of treads that serve as treads are installed in a horizontal position between the left and right side plates in a stepped manner with a predetermined space between the left and right side plates. Risers are provided.

On the tread surface (upper surface) of the tread plate, three grooves are formed to improve the visibility of the step nosing corresponding to the tip of the tread plate and to prevent slippage. The upper portion of the riser plate is inserted into a portion recessed from the front end surface (nosing side) on the back side of the upper step plate, and the lower portion is in contact with the rear end surface of the lower step plate.

As a tread plate used for such stairs, conventionally, as seen in Patent Documents 1 and 2, etc., a wooden base material such as MDF, particle board, laminated lumber, and plywood has a pattern such as wood grain. It is well known that a decorative material made of a resin sheet or the like is adhered to each other.

Further, in recent years, as shown in Patent Document 3, a technique for printing on the surface of the footboard by inkjet printing has been proposed. FIGS. 14A and 14B show an example of inkjet printing on a general footboard. As shown in FIG. 14A, the footboard 80 is composed of a wood-based base material 81 and a wood-based decorative veneer 82 bonded together. A riser 88 is arranged on the back surface of the footboard 80, and a groove 85 is formed on the side of the tread surface of the footboard 80 on the nosing 86 side to improve visibility and prevent slipping.

As shown in FIG. 14B, the tread surface including the wall surface of the groove 85 is formed with a colored layer 91 formed by applying, for example, a white water-based paint and drying it. A printed layer 92 is formed on the colored layer 91 by applying ultraviolet curable ink in the form of particles by inkjet printing, printing a pattern such as wood grain, and curing with ultraviolet rays.

Japanese Utility Model Publication No. 5-12422 JP-A-10-72923 JP 2016-210022 A

However, when a tread is manufactured by such a method, the ink adhered to the wall surface (surface) of the groove of the tread by inkjet printing flows on the wall surface of the groove and aggregates before being cured by ultraviolet rays. There was a risk that the printed pattern near the groove would be blurred.

Therefore, it is conceivable to form a receiving layer made of resin after forming the colored layer, and then form a print layer on the surface of this receiving layer by inkjet printing. However, even in this case, the ink particles do not adhere well to the wall surface of the groove on which the receiving layer is formed, and the pattern on the tread surface may appear blurred.

The present invention has been made in view of this problem, and by improving the fixation of ink to the tread surface, particularly the grooves, it is possible to suppress blurring of the printed pattern and to make the tread surface including the grooves more natural. To provide a footboard which can give a good impression.

In order to achieve the above object, a method for manufacturing a footboard according to the present invention includes: a preparation step of preparing a footboard by bonding a decorative material to a wooden base material so that the surface of the decorative material serves as a tread surface; a groove forming step of forming a groove on the tread surface side of the groove, and a receiving layer forming step of forming an uncured receiving layer by coating the tread surface including the wall surface of the groove with an ultraviolet curable resin in an uncured state; a first curing step of obtaining a semi-cured receiving layer by irradiating the tread surface of the footboard on which the uncured receiving layer is formed with ultraviolet rays so that the uncured receiving layer is not completely cured; a printing step of applying a UV curable ink in an uncured state to the surface of the semi-cured receiving layer in the form of particles by inkjet printing to print a predetermined pattern on the surface of the semi-cured receiving layer; a second curing step of curing the ink adhering to the semi-cured receiving layer and further curing the semi-cured receiving layer by irradiating the tread surface on which a predetermined pattern is printed with ultraviolet light; characterized by comprising

According to the present invention, an uncured UV-curable ink is applied to the semi-cured receiving layer, which has not been completely cured by ultraviolet rays, in the form of particles by inkjet printing. can improve the fixability of the ink compared to the case of adhering. This is because the semi-cured receiving layer can fix the ink more stably than the uncured receiving layer, and furthermore, in the semi-cured receiving layer, the polymerization reaction and cross-linking reaction of the ultraviolet curable resin due to the irradiation of ultraviolet rays. is not sufficient (not completely completed), the affinity between the resin of the semi-cured receiving layer and the uncured UV-curable ink (resin) is high, and they tend to chemically adhere to each other. it is conceivable that. As a result, it is possible to prevent the granular ink adhering to the semi-cured receiving layer on the wall surface of the groove from flowing into the groove and aggregating. As a result, blurring of the printed pattern can be suppressed by improving the fixability of the ink, especially to the grooves of the tread surface.

Then, in the second curing step, when the tread surface on which the predetermined pattern is printed is irradiated with ultraviolet rays, the polymerization reaction and the cross-linking reaction are also promoted between the semi-cured receiving layer and the ink. Adhesion between the receiving layer and the ink can be ensured. As a result, by improving the fixability of the ink to the tread surface, especially the groove portion, it is possible to suppress peeling of the printed pattern. As used herein, "not completely cured" means that the ultraviolet curable resin is cured under conditions where the irradiation amount is less than the conditions under which the ultraviolet curable resin is completely cured by irradiation with ultraviolet rays. For example, an irradiation dose of 40 to 60% of the irradiation dose for complete curing is preferred.

In a preferred embodiment, in the second curing step, ultraviolet rays are irradiated so that the ink and the semi-cured receiving layer are not completely cured, and after the second curing step, the tread surface is coated with a visible light. A protective layer forming step of forming a protective layer by coating an uncured UV curable resin through which light rays transmit; and a third curing step of curing and further curing the ink and the semi-cured receiving layer.

According to this aspect, by forming a protective layer that transmits visible light on the ink adhered by the printing process, the visibility of the printed pattern is ensured, and the ink printed on the tread surface is protected from peeling off. can do. Here, when forming the protective layer, since the ink and the resin of the semi-cured receiving layer are not completely cured by the irradiation of the ultraviolet rays, the ultraviolet curable resin is coated in an uncured state for protection. Forming the layer can improve the adhesion between the ink and the semi-cured receiving layer and the protective layer. This is because in the ink and the semi-cured receiving layer, the polymerization reaction and cross-linking reaction of the UV-curable resin due to UV irradiation are not sufficient (not completely completed), so the uncured UV-curable resin in the protective layer is , and it is thought that it is easy to chemically adhere to these.

In this state, when the tread on which the protective layer is formed in the third curing step is irradiated with ultraviolet rays, a polymerization reaction and a cross-linking reaction also occur between the ink and the semi-cured receiving layer and the protective layer. Since it is accelerated, the adhesion of the protective layer to the ink and the semi-cured receiving layer can be ensured. This makes it possible to form a protective layer that is difficult to peel off from the tread surface.

In another preferred embodiment, in the preparation step, a wood-based decorative veneer as the decorative material is attached to the wood-based base material, and after the groove forming step and before the receiving layer forming step, the grooves are formed. The method further includes a painting step of painting the tread surface including the wall surface of the groove by applying a water-based paint to the tread surface including the wall surface and then drying the water-based paint.

According to this aspect, when the water-based paint is dried after being applied, the surface of the wood-based decorative veneer may become fuzzy. However, since the receiving layer is formed on the fuzzy surface, it is possible to suppress the influence of the fuzzy surface on the degree of adhesion of the ink in the subsequent printing process.

In another preferred aspect, in the preparation step, a side decorative material is further attached to the front side surface of the footboard corresponding to the step nosing, and the surface of the side decorative material is applied from the receiving layer forming step to the first receiving layer forming step. A series of steps up to the curing step of 2 are performed. According to this aspect, the step nosing to which the side surface decorative material is attached can be efficiently subjected to the same surface treatment as the tread surface.

In another preferred embodiment, in the painting step, the part from the step nosing on the back surface of the footboard to at least the position where the riser plate is arranged is painted, and in the printing step, the painted back surface is coated with an ultraviolet curing type is applied in an uncured state in the form of granules by inkjet printing to print a predetermined pattern, and in the second curing step, the printed back surface is irradiated with ultraviolet rays to form the footboard. Cure the ink on the back of the

According to this aspect, since a predetermined pattern is printed by inkjet printing on the part from the nosing of the tread to at least the riser, it is possible to enhance the appearance of the tread when viewed from below the stairs.

According to the method of manufacturing a tread according to the present invention, by improving the fixability of ink to the tread surface, particularly to the grooves, it is possible to suppress blurring of the printed pattern and to give a more natural impression to the tread surface including the grooves. You can get a tread that can give

1 is a schematic perspective view of a staircase with treads according to an embodiment of the invention; FIG. 1 is a flowchart of a method for manufacturing a footboard according to the present invention; FIG. It is a figure where it uses for description of the preparation process shown in FIG. 2, (A) is an exploded perspective view, (B) is sectional drawing of (A). 3 is a cross-sectional view for explaining a groove forming step shown in FIG. 2; FIG. FIG. 3 is a cross-sectional view for explaining the coating process shown in FIG. 2 ; 3 is a cross-sectional view for explaining a receiving layer forming step shown in FIG. 2; FIG. FIG. 3 is a cross-sectional view for explaining a first curing step shown in FIG. 2; FIG. 3 is a cross-sectional view for explaining the printing process shown in FIG. 2 ; FIG. 3 is a cross-sectional view for explaining a second curing step shown in FIG. 2; 3 is a cross-sectional view for explaining a protective layer forming step shown in FIG. 2; FIG. 1 is a schematic configuration diagram for explaining a roll coater used for resin coating, painting, etc., used in an embodiment of a footboard manufacturing method according to the present invention; FIG. 3 is a cross-sectional view for explaining a third curing step shown in FIG. 2. FIG. FIG. 5 is a cross-sectional view for explaining an additional step in the embodiment of the footboard manufacturing method according to the present invention; It is a figure provided for description of the structure of the conventional footboard, (A) is the partial side view, (B) is an enlarged sectional view of the A part of (A).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 13 are diagrams for explaining each step of an embodiment of a staircase 1 having a footboard 10 according to an embodiment of the present invention and a method of manufacturing the footboard 10. FIG. In each drawing, the plate thickness of each part, the thickness of each layer, the size of the groove, etc. are exaggerated from the actual size ratio for the purpose of easy understanding of the present invention and drawing convenience. (The same applies to FIG. 14 described above).

1. Staircase 1 with Footboard 10 FIG. 1 is a schematic perspective view of a staircase 1 with a footboard 10 according to an embodiment of the present invention. As shown in FIG. 1, a staircase 1 is installed in a building such as a house, and includes a plurality of treads 10, 10, . . . and risers 18, 18, . 17, 17 and . Specifically, the footboards 10 having a required number of steps, which serve as the tread surfaces, are mounted in a stepped manner between the left and right side plates 17, 17 in a horizontal posture with a predetermined space in the vertical direction and in the front-rear direction. A riser 18 is arranged between 10 .

Three grooves 15 are formed on the tread surface (upper surface) of the tread plate 10 to improve the visibility of the step nosing 16 and prevent slippage. The upper portion of the riser plate 18 is inserted into a portion recessed by a predetermined distance from the front end surface (nosing 16 side) of the rear surface side of the upper step plate 10, and the lower portion is in contact with the rear end surface of the lower step plate 80. there is

In this embodiment, the tread surface of the tread 10 including the grooves 15 is provided with a printed pattern, which will be described later. If necessary, the surface of the nosing 16 and the back of the tread 10, which will be described later, also have printed patterns. It has been subjected. The method of manufacturing the footboard 10 will be described below with reference to the flow diagram shown in FIG. 2 and each step shown in the flow diagram with reference to FIGS.

2. Preparatory Step S1 (FIG. 3) First, the preparatory step S1 shown in FIG. 2 is performed. In the preparation step S1, as shown in FIG. 3A, the decorative material 12 and, if necessary, the side decorative material 13 are adhered to the wood-based base material 11 with an adhesive or the like, thereby forming the surface of the decorative material 12. prepares a tread plate 10 that serves as a tread surface.

Here, the wood-based base material 11 is obtained by laminating base layers 11b and 11c on both sides of a base material layer 11a. In this embodiment, the base material layer 11a is made of plywood, and the underlying layers 11b and 11c are made of medium density fiberboard (MDF). However, the wood-based base material 11 is not limited to the above configuration, and may be composed only of a base material layer, for example. In addition to the materials mentioned above, materials for the base material layer and the underlayer include solid wood, particle board (PB), wood fiber board (insulation board, hard board, etc.), and oriented strand board (OSB). , LVL, laminated wood, or a laminate thereof.

As described above, the decorative material 12 is attached to the surface of the wooden base material 11 , and the surface of the decorative material 12 serves as the tread surface of the footboard 10 . In addition, in this embodiment, a side decorative material 13 is adhered to the front side surface corresponding to the step nosing of the footboard as necessary. In this embodiment, the decorative material 12 and the side decorative material 13 are, for example, a decorative veneer such as a veneer having a thickness of about 0.1 to 1.0 mm.

The decorative material 12 is not limited to a wood-based material as long as a desired pattern can be printed by inkjet printing in the printing step S6, which will be described later. Sheets, paper materials such as kraft paper, impregnated paper in which melamine resin is impregnated in kraft paper, and wood-based decorative veneers can be used. Decorative veneers include, for example, beech, oak, maple, zelkova, walnut, linden, oak, yachidamo, paulownia, cypress, cedar, mahogany, teak, rosewood, horse chestnut, black oyster, shioji, elm, birch, rosewood, Alternatively, ebony and the like can be mentioned.

3. Groove Forming Step S2 (FIG. 4) Next, the groove forming step S2 shown in FIG. 2 is performed. As shown in FIG. 4, in the groove forming step S2, a wood grooving machine is used to form three grooves 15 transversely across the tread surface of the tread 10 on the nosing 16 side of the tread surface. . The groove 15 serves both to improve the visibility of the footboard and to prevent slippage, has a V-shaped cross section, and has a depth of about 1.2 to 2.0 mm. Here, if the grooves 15 are buried in resin or the like before the protective layer forming step S8 described later, they will not function as anti-slip. It is cut down to 11b.

In this embodiment, the groove 15 having a V-shaped cross section is formed, but the groove may have a U-shaped, trapezoidal, or rectangular cross-sectional shape, for example. Further, in this groove forming step S2, a concave groove (not shown) for inserting the riser 18 may be formed on the back side of the footboard 10 .

4. Painting Step S3 (FIG. 5) Next, the painting step S3 shown in FIG. 2 is performed. As shown in FIG. 5, in the painting step S3, the tread surface including the wall surface of the groove 15 is painted. Specifically, a water-based paint is applied to the tread surface including the wall surface of the groove 15, and then the water-based paint is dried by natural drying or drying with a dryer or the like. Thereby, a coating layer (colored layer) 21 is formed on the tread surface including the wall surface of the groove 15 . This coating layer 21 is a layer uniformly formed on the tread surface including the wall surface of the groove 15 .

The water-based paint is a generally known colored paint, and may be any water-based paint having a color that makes the printed pattern stand out in the printing step S6 described later. For example, the color of the water-based paint is white. , brown and the like.

As a coating device, for example, a roll coater 40 as shown in FIG. The roll coater 40 includes a coating roll 41 having a sponge outer peripheral portion, a pickup roll 42, and a backup roll 43. The water-based paint is temporarily accumulated above the coating roll 41 and the backup roll 43 and sent out from between the rolls. It is applied to the tread surface of the tread 10 moving from left to right in the figure.

Although the present embodiment includes the painting step S3, the painting step S3 may be omitted and the receiving layer forming step S4 may be performed if the pattern printed in the later-described printing step S6 looks good.

5. Receiving Layer Forming Step S4 (FIG. 6) Next, the receiving layer forming step S4 shown in FIG. 2 is performed. As shown in FIG. 6, in the receiving layer forming step S4, the tread surface including the wall surface of the groove 15 on which the coating layer 21 is formed is coated with an uncured UV curable resin to form an uncured receiving layer 22A. Form. Here, in order to coat the tread surface with the UV curable resin in an uncured state, a roll coater having the same configuration as that used in the coating step S3 may be used. Here, the term "receiving layer" as used herein refers to a layer that receives ink in order to stabilize the fixing of the ink in the printing step S6, which will be described later.

The UV curable resin forming the uncured receiving layer 22A is generally known, and contains resins such as reactive oligomers and reactive monomers, photopolymerization initiators, and the like. UV curable resins are cured in an uncured state by a polymerization reaction and a cross-linking reaction when irradiated with ultraviolet rays.

For example, as long as the coating layer 21 is not formed, the UV-curable monomers and oligomers may include urethane acrylate, acrylic resin acrylate, epoxy acrylate, polyester acrylate, and the like. Here, in the present embodiment, since the coating layer 21 is provided in the coating step S3, among these resins, a resin having light transmittance is preferable.

When the surface of a wood-based decorative veneer is used as the decorative material 12, the surface of the wood-based decorative veneer may become fuzzy when the water-based paint is applied and then dried in the painting step S3. However, since the uncured receiving layer 22A is formed on the fuzzy surface, it is possible to suppress the influence of the fuzzy surface on the adhesion of ink in the subsequent printing step S6.

6. First Curing Step S5 (FIG. 7) Next, the first curing step S5 shown in FIG. 2 is performed. As shown in FIG. 7, in the first curing step S5, a line-type UV irradiator 50 is used to apply ultraviolet (UV) light to the tread surface of the footboard 10 on which the uncured receiving layer 22A is formed. A first semi-cured receiving layer 22B is obtained by adjusting the irradiation dose so that the receiving layer 22A is not completely cured.

Here, the degree of curing from the uncured receiving layer 22A to the first semi-cured receiving layer 22B can be adjusted by the amount of ultraviolet (UV) irradiation (=UV exposure amount/accumulated light amount). It is preferably ² or less. The UV dose (unit: mJ/cm ² ) is determined by UV illuminance (unit: mW/cm ² )×irradiation time (unit: seconds). Therefore, by making the UV illumination intensity and/or irradiation time lower and/or shorter than when the uncured receiving layer 22A is completely cured, obtaining the first semi-cured receiving layer 22B that is not completely cured. can be done. Here, the amount of UV irradiation and the mode of irradiation are selected based on many prototype experiments and the like.

7. About the printing step S6 (FIG. 8) Next, the printing step S6 shown in FIG. 2 is performed. As shown in FIG. 8, in the printing step S6, a pattern such as wood grain is printed by applying an uncured UV curable ink to the surface of the first semi-cured receiving layer 22B in the form of particles by inkjet printing. do. In this state, the print layer 23A (specifically, the adhered ink) is uncured.

An ultraviolet curable ink used for inkjet printing includes at least an ultraviolet curable resin obtained by adding a photopolymerization initiator to a reactive oligomer or reactive monomer, and a colorant. For example, four types of ink are prepared by individually containing four colorants of yellow, magenta, cyan, and black in the ultraviolet curing resin, and using these inks, the tread surface (first semi-cured receiving A pattern such as wood grain is printed on the layer 22B).

Inkjet printing is performed by an inkjet printer. An inkjet printer contains inks used for general printing, and includes a head that ejects each ink individually in accordance with a predetermined pattern such as wood grain to be printed, and a feeder that feeds the footboard 10 . The ink jet printer feeds the footboard 10 with a feeder while ejecting each ink from a head in a direction substantially perpendicular to the tread surface of the tread surface (first semi-cured receiving layer) according to the pattern such as wood grain. 22B) is printed with a pattern such as wood grain, thereby obtaining an uncured printed layer 23A. The uncured printing layer 23A has granular ink adhered thereto, and in this embodiment, the surface of the first semi-cured receiving layer 22B is exposed between the adhered granular inks. ing.

In this way, in the first curing step S5, an uncured UV curable ink is adhered to the first semi-cured receiving layer 22B, which has not been completely cured by the UV light, in the form of particles by inkjet printing. Therefore, the adhesion of the ink can be improved as compared with the case where the ink is adhered to the completely cured receiving layer.

This is because, in the first semi-cured receiving layer 22B, the polymerization reaction and the cross-linking reaction of the UV-curable resin due to the irradiation of ultraviolet rays are not completely completed. This is probably because the ink (resin) of the ultraviolet curable type has a high affinity and chemically adheres easily. As a result, it is possible to prevent the granular ink adhering to the first semi-cured receiving layer 22B on the wall surface of the groove 15 from flowing into the groove 15 and aggregating. As a result, by improving the fixability of the ink to the tread surface, particularly the grooves 15, it is possible to suppress the blurring of the printed pattern.

8. Second Curing Step S7 (FIG. 9) Next, the second curing step S7 shown in FIG. 2 is performed. As shown in FIG. 9, in the second curing step S7, the tread surface on which the pattern such as wood grain is printed is irradiated with ultraviolet rays using a line-type UV irradiator 50 to perform first semi-curing. The ink (uncured print layer 23A (see FIG. 8)) adhering to the receiving layer 22B (see FIG. 8) is cured, and the first semi-cured receiving layer 22B is further cured.

Specifically, in the second curing step S7, the UV irradiation amount ( UV illuminance and/or irradiation time) is adjusted to irradiate the tread surface with ultraviolet rays. As a result, the uncured printed layer 23A is further cured than the semi-cured printed layer 23B which is not completely cured, and the first semi-cured receiving layer 22B obtained in the first curing step S5, and the uncured printed layer 23A is cured more than the first semi-cured receiving layer 22B which is not completely cured. A second semi-cured receiving layer 22C is obtained.

Here, in the second curing step S7, when the tread surface on which a pattern such as wood grain is printed is irradiated with ultraviolet rays, even between the ink (uncured print layer 23A) and the first semi-cured receiving layer 22B, Polymerization and cross-linking reactions are accelerated. Therefore, the adhesion between the second semi-cured receiving layer 22C and the ink can be ensured. As a result, the fixability of the ink in the grooves 15 on the tread surface can be improved, and peeling of the printed pattern including the vicinity of the grooves 15 can be reduced.

In this embodiment, the semi-cured print layer 23B and the second semi-cured receiving layer 22C are formed in order to perform the protective layer forming step S8, which will be described later. is not provided (that is, the protective layer forming step S8 is not performed), ultraviolet rays are irradiated to completely cure the ink (uncured printing layer 23A) attached to the first semi-cured receiving layer 22B. , the first semi-cured receiving layer 22B may be completely cured. Here, the term "completely cured" refers to a state in which the hardness of the UV-curable resin does not increase any further even when irradiated with UV rays.

9. Protective Layer Forming Step S8 (FIG. 10) Next, the protective layer forming step S8 shown in FIG. 2 is performed. As shown in FIG. 10, in the protective layer forming step S8, an ultraviolet curable resin that transmits visible light is applied to the tread surface on which the second semi-cured receiving layer 22C and the semi-cured printing layer 23B (see FIG. 9) are formed. It is coated in an uncured state to form an uncured protective layer 24A. Also in forming the uncured protective layer 24A, a roll coater having the same configuration as that used in the coating step S3 can be used.

Examples of the ultraviolet curable resin used here, through which visible light is transmitted, include the resins exemplified in the above-described receiving layer forming step S4. Abrasion resistance, water resistance, heat resistance, etc. are improved. In addition, the ultraviolet curable resin may further contain a filler made of a ceramic material or a metal material. Thereby, the wear resistance of the protective layer 24 can be improved.

As described above, when forming the uncured protective layer 24A, the resins of the second semi-cured receiving layer 22C and the semi-cured printing layer 23B are in a semi-cured state that is not completely cured by irradiation with ultraviolet rays. be. Therefore, when the uncured protective layer 24A is formed by coating the UV curable resin in an uncured state, the second semi-cured receiving layer 22C and the semi-cured printed layer 23B and the uncured protective layer 24A are separated. Adhesion can be improved.

This is because in the second semi-cured receiving layer 22C and the semi-cured printing layer 23B, the polymerization reaction and the cross-linking reaction of the UV-curable resin due to irradiation with UV rays are insufficient (because they are not completely completed). This is probably because the uncured UV curable resin of the protective layer 24A tends to chemically adhere to them.

10. Third Curing Step S9 (FIG. 12) Next, the third curing step S9 shown in FIG. 2 is performed. As shown in FIG. 12, in the third curing step S9, the line-type UV irradiator 50 is used to irradiate the tread surface on which the uncured protective layer 24A is formed with ultraviolet rays at a predetermined dose. By curing the uncured protective layer 24A, the ink (semi-cured printing layer 23B) and the second semi-cured receiving layer 22C (see FIG. 10) are further cured, and the completely cured protective layer 24 and the printing layer 23, and the receiving layer 22, the decorative layer 20 can be obtained.

Here, in the third curing step S9, when the tread surface on which the uncured protective layer 24A is formed is irradiated with ultraviolet rays, the ink (semi-cured print layer 23B), the second semi-cured receiving layer 22C, and the uncured Since the polymerization reaction and the cross-linking reaction are promoted also between the protective layer 24A and the protective layer 24A, the adhesion of the protective layer 24 to the printing layer 23 and the receiving layer 22 can be ensured. This makes it possible to form the protective layer 24 that is difficult to peel off from the tread surface.

11-1. Additional Step 1 (Printing Nosing, etc.) Further, as an additional step 1, the back surface of the footboard 10 may be printed as follows. Specifically, in the preparatory step S1, a series of steps from the receiving layer forming step S4 to the second curing step S7 are performed on the surface of the laminated side face decorative material 13 . In this case, in the first curing step S5, the first semi-cured receiving layer is formed by irradiating ultraviolet rays so that the uncured receiving layer formed in the receiving layer forming step S4 is not completely cured. After that, in the printing step S6, after forming an uncured printing layer, in a second curing step S7, the first semi-cured receiving layer and the uncured printing layer are completely cured.

Thereby, as shown in FIG. 13, a decorative layer 31 composed of a receiving layer and a printing layer can be obtained. In this manner, a pattern such as wood grain can be formed on the step nosing 16 to which the side surface decorative material 13 is adhered, in accordance with the above process for the tread surface.

Here, in the printing step S6, it is preferable to print such that the pattern such as wood grain printed on the tread surface and the pattern printed on the side decorative material 13 are continuous. A natural impression can be given by a pattern such as this continuous wood grain.

11-2. Regarding Additional Step 2 (Printing on Back Surface, etc.) Further, as an additional step 2, the back surface of the footboard 10 may be printed as follows. First, in the painting step S3, the part from the nosing 16 on the back surface of the footboard 10 to at least the position where the riser 18 is arranged is painted. Next, without forming a receiving layer on the back surface, in the printing step S6, a predetermined pattern is printed by applying an uncured UV curable ink in the form of particles to the coated back surface by inkjet printing. In a second curing step S7, the printed back surface is irradiated with ultraviolet rays to completely cure the ink on the back surface of the footboard.

Thereby, as shown in FIG. 13, a decorative layer 32 composed of a paint layer and a printed layer can be formed. In this way, the decorative layer 32 with a pattern such as wood grain is formed on the rear surface from the nosing 16 of the tread 10 to at least the riser 18, so that the tread 10 can be improved in appearance when viewed from below the staircase 1.例文帳に追加.

The present invention will be described below based on examples.
(Example)
First, on the surface of the footboard shown in FIG. 3, an ultraviolet curable resin (photosensitive resin: manufactured by DIC) was applied in an uncured state to form a receiving layer. This uncured receiving layer was irradiated with ultraviolet rays at a dose of 240 mJ/cm ² to form a semi-cured receiving layer that was not completely cured. The irradiation amount of ultraviolet rays for completely curing the ultraviolet curable resin is 450 mJ/cm ² .

Next, on the surface of this semi-cured receiving layer, using a printer having an inkjet head (manufactured by Kyocera), four-color UV-curing ink containing four colorants of yellow, magenta, cyan, and black was applied. An uncured print layer was formed using ink (acrylic synthetic resin: manufactured by DIC Corporation). Then, the semi-cured receiving layer and the uncured printing layer were irradiated with ultraviolet rays at a dose of 120 mJ/cm ² so as to completely cure them.

(Comparative example)
First, an ultraviolet curable resin (photosensitive resin: manufactured by DIC) was applied in an uncured state to form a receiving layer. The uncured receiving layer was irradiated with ultraviolet rays at a dose of 500 mJ/cm ² to form a completely cured receiving layer. Next, an uncured print layer similar to that of Example 1 was formed on the surface of this receiving layer. Then, ultraviolet rays were irradiated at an irradiation dose of 90 mJ/cm ² so that the uncured printed layer was completely cured.

<Peeling test>
11 lines each in the vertical direction and the horizontal direction so as to form 10×10 square grids with a cutter knife on the surface of the footboards of Examples and Comparative Examples on which the printed layer was formed. I made a notch. Next, an adhesive tape was attached to the entire surface of the printed layer divided into 100 squares, and the adhesive tape was peeled off to confirm the number of peeled printed layers.

As a result, none of the 100 samples of the example exhibited peeling of the printed layer, while 13 of the 100 samples of the comparative example showed peeling of the printed layer. This is because the non-cured printed layer was formed on the semi-cured receiving layer in the examples, so that when the semi-cured receiving layer and the uncured printed layer were irradiated with ultraviolet rays, polymerization occurred between them. It is considered that the fixability of the printed layer was improved due to the occurrence of reaction and cross-linking reaction.

An embodiment of the present invention has been described in detail above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention described in the scope of claims. Design changes can be made.

10: footboard, 11: wooden base material, 11a: base material layer, 11b, 11c: underlay layer, 12: decorative material, 15: groove, 20: decorative layer, 21: paint layer, 22: receiving layer, 22A : uncured receiving layer 22B: first semi-cured receiving layer 22C: second semi-cured receiving layer 23: printed layer 23A: uncured printed layer 23B: semi-cured printed layer 24: protective layer 24A : Uncured protective layer

Claims (4)

A tread plate in which a decorative material is attached to a wooden base material, and the surface of the decorative material serves as a tread surface,
An anti-slip groove having a V-shaped cross section is formed on the tread surface side of the tread plate,
On the tread surface including the wall surface of the groove, a receiving layer is formed by curing an ultraviolet curable resin so as to leave the shape of the groove,
A printed layer in which a predetermined pattern is inkjet-printed by attaching ultraviolet curable ink in the form of particles to the surface of the receiving layer formed on the wall surface of the groove and the tread surface of the tread is formed. and
The receiving layer and the printing layer are formed by printing ink of the uncured ultraviolet curable resin on the surface of the receiving layer, which is obtained by semi-curing the ultraviolet curable resin so that it is not completely cured by irradiation with ultraviolet rays. A footboard characterized by being a layer cured by further irradiating ultraviolet rays to the foot surface on which a cured printed layer is formed. The decorative material is a wood-based decorative veneer,
A colored layer colored with a water-based paint is formed on the tread surface including the wall surface of the groove,
2. The footboard according to claim 1, wherein a layer made of a resin having light transmittance is formed as the receiving layer on the surface of the colored layer. A side decorative material is further attached to the front side surface corresponding to the step nosing of the footboard,
3. The footboard according to claim 1, wherein the receiving layer and the printing layer are formed on the surface of the side decorative material. A part from the step nosing on the back surface of the footboard to at least a position where the riser is arranged is painted,
4. The footboard according to claim 3 , wherein a predetermined pattern is printed on the painted back surface by applying ultraviolet curable ink in the form of particles.

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