JP6923399B2 - Manufacturing method of tread - Google Patents

Description

The present invention relates to a method for manufacturing a tread plate used for stairs, and more particularly to a method for manufacturing a tread plate for forming a groove provided for slip prevention or the like on the tread surface and printing a pattern such as wood grain by inkjet printing.

As a staircase installed in a building such as a house, a staircase having a plurality of treads arranged in a staircase pattern and at least side plates for fixing these on the left and right sides is known. Specifically, the stairs are attached by stepping the required number of steps to be the treads in a horizontal position between the left and right side plates at predetermined intervals in the vertical and front-rear directions. The riser board is arranged.

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

As a tread board used for such a staircase, as seen in Patent Documents 1 and 2, a pattern such as wood grain is conventionally formed on a wood-based base material such as MDF, particle board, laminated wood, and plywood. It is well known that a decorative material made of an applied resin sheet or the like is bonded.

Further, in recent years, as shown in Patent Document 3, a technique of printing on the surface of a tread plate by inkjet printing has been proposed. 14 (A) and 14 (B) show an example in which inkjet printing is performed on a general tread plate. As shown in FIG. 14A, the tread plate 80 has a wood-based decorative veneer 82 bonded to a wood-based base material 81. A riser plate 88 is arranged on the back surface of the tread plate 80, and a groove 85 having both improved visibility and anti-slip is formed on the step nose 86 side of the tread surface of the tread plate 80.

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

Jitsufuku No. 5-12422 Japanese Unexamined Patent Publication No. 10-72923 Japanese Unexamined Patent Publication No. 2016-21022

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

Therefore, it is also conceivable to form a receiving layer made of resin after forming the colored layer, and to form a printing layer on the surface of the receiving layer by inkjet printing. However, even in this case, the ink particles may not be well fixed on the wall surface of the groove on which the receiving layer is formed, giving the impression that the pattern on the tread surface is blurred.

The present invention has been made in view of such a problem. By improving the fixability of the ink on the tread surface, particularly on the groove portion, it is possible to suppress blurring of the printed pattern and the tread surface including the groove is more natural. The purpose is to provide a method for manufacturing a tread plate that can give a good impression.

In order to achieve the above object, the method for manufacturing a tread plate according to the present invention includes a preparatory step of preparing a tread plate having a surface of the decorative material as a tread surface by laminating a decorative material on a wood-based base material, and the tread plate. A groove forming step of forming a groove on the tread surface side of the above, and a receiving layer forming step of covering the tread surface including the wall surface of the groove with an ultraviolet curable resin in an uncured state to form an uncured receiving layer. The first curing step of obtaining a semi-cured receiving layer by irradiating the tread surface of the tread plate on which the uncured receiving layer is formed with ultraviolet rays so that the uncured receiving layer is not completely cured. A printing step in which an ultraviolet curable ink is adhered to the surface of the semi-cured receiving layer in a granular state by inkjet printing in an uncured state, and a predetermined pattern is printed 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 rays. It is characterized by including.

According to the present invention, the ultraviolet curable ink is adhered to the semi-cured receiving layer that has not been completely cured by ultraviolet rays in an uncured state by inkjet printing, so that the ink is attached to the completely cured receiving layer. It is possible to improve the fixability of the ink as compared with the case where the ink is adhered. This is because the semi-cured receiving layer can fix the ink more stably than the uncured receiving layer, and further, in the semi-cured receiving layer, the polymerization reaction and the cross-linking reaction of the ultraviolet curable resin by irradiation with ultraviolet rays. Is not sufficient (not completely completed), so the resin of the semi-cured receiving layer and the uncured UV-curable ink (resin) have a high affinity, and these are easily chemically adhered. 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 agglutinating. As a result, blurring of the printed pattern can be suppressed by improving the fixability of the ink on the tread surface, particularly in the groove.

Then, in the second curing step, when the tread surface on which a predetermined pattern is printed is irradiated with ultraviolet rays, the polymerization reaction and the cross-linking reaction are promoted also between the semi-cured receiving layer and the ink, so that the semi-cured surface is semi-cured. Adhesion between the receiving layer and the ink can be ensured. As a result, peeling of the printed pattern can be suppressed by improving the fixability of the ink on the tread surface, particularly in the groove portion. In addition, "not completely cured" in the present specification means that the ultraviolet curable resin is cured under the condition that the irradiation amount is smaller than the condition that the ultraviolet curable resin is completely cured by irradiation with ultraviolet rays. For example, an irradiation amount of 40 to 60% of the irradiation amount that completely cures is preferable.

In a preferred embodiment, in the second curing step, the ink is irradiated with ultraviolet rays so that the ink and the semi-cured receiving layer are not completely cured, and after the second curing step, the tread surface is visible. The protective layer is formed by coating the UV-curable resin through which light rays pass in an uncured state to form a protective layer, and by irradiating the tread surface on which the protective layer is formed with ultraviolet rays. It includes 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 through which visible light is transmitted on the ink adhered by the printing process, the visibility of the printed pattern is ensured and the peeling of the ink printed on the tread surface is protected. 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 irradiation with ultraviolet rays, the ultraviolet curable resin is coated in an uncured state to protect the protective layer. By forming the layer, the adhesion between the ink and semi-cured receiving layer and the protective layer can be improved. This is because the polymerization reaction and cross-linking reaction of the UV curable resin by UV irradiation are not sufficient (not completely completed) in the ink and the semi-curable receiving layer, so the uncured UV curable resin of the protective layer is used. , It is considered that this is because it easily adheres to these chemically.

Then, in this state, when the tread surface on which the protective layer is formed is irradiated with ultraviolet rays by the third curing step, a polymerization reaction and a cross-linking reaction also occur between the ink and the semi-curing receiving layer and the protective layer. Since it is promoted, 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 preparatory step, a wood-based decorative veneer is attached to the wood-based base material as the decorative material, and after the groove forming step and before the receiving layer forming step, the groove is formed. The coating step of painting the tread surface including the wall surface of the groove is further included by applying the 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 applied and then dried, the surface of the wood-based decorative veneer may become fluffy. However, since the receiving layer is formed on the fluffy surface, the fluffy surface can suppress the influence on the adhesion of the ink in the subsequent printing process.

In another preferred embodiment, in the preparatory step, the side surface decorative material is further attached to the front side surface corresponding to the nose of the tread plate, and the surface of the side surface decorative material is subjected to the first step from the receiving layer forming step. Perform a series of steps up to the curing step of 2. According to this aspect, it is possible to efficiently perform the same surface treatment as the tread surface on the nose to which the side decorative material is attached.

In another preferred embodiment, in the painting step, the portion of the back surface of the tread plate from the nose to at least the position where the riser plate is arranged is painted, and in the printing step, the painted back surface is UV-curable. In the uncured state, the ink is adhered in granular form by inkjet printing to print a predetermined pattern, and in the second curing step, the printed back surface is irradiated with ultraviolet rays to cause the tread plate. Cure the ink on the back side of.

According to this aspect, since a predetermined pattern is printed on the portion from the nose of the tread plate to at least the riser plate by inkjet printing, the appearance of the tread plate seen from the lower part of the stairs can be enhanced.

According to the method for manufacturing a tread plate according to the present invention, by improving the fixability of ink especially on the groove portion of the tread surface, it is possible to suppress blurring of the printed pattern and give a more natural impression to the tread surface including the groove. You can get a footboard that can give you.

It is a schematic perspective view of the stairs provided with the tread plate which concerns on embodiment of this invention. It is a flow chart of the manufacturing method of the tread plate which concerns on this invention. It is a figure provided for the explanation of the preparation process shown in FIG. 2, (A) is an exploded perspective view, and (B) is a cross-sectional view of (A). It is sectional drawing which is provided for the explanation of the groove forming process shown in FIG. It is sectional drawing which is provided for the explanation of the coating process shown in FIG. It is sectional drawing which is provided for the explanation of the receiving layer forming process shown in FIG. FIG. 5 is a cross-sectional view provided for explaining the first curing step shown in FIG. It is sectional drawing which is provided for the explanation of the printing process shown in FIG. It is sectional drawing which is provided for the description of the 2nd curing process shown in FIG. FIG. 5 is a cross-sectional view provided for explaining the protective layer forming step shown in FIG. It is a schematic block diagram provided for the description of the roll coater used for resin coating, coating, etc. used in one Embodiment of the tread plate manufacturing method which concerns on this invention. It is sectional drawing which is provided for the explanation of the 3rd curing process shown in FIG. It is sectional drawing which is provided for the explanation of the additional process in one Embodiment of the manufacturing method of the tread plate which concerns on this invention. It is a figure provided for the explanation of the structure of the conventional tread plate, (A) is a partial side view thereof, and (B) is an enlarged sectional view of the part A of (A).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 13 are diagrams for explaining each step of the stairs 1 provided with the tread plate 10 according to the embodiment of the present invention and one embodiment of the method for manufacturing the tread plate 10. In each drawing, the plate thickness of each part, the thickness of each layer, the size of the groove, etc. are exaggerated to be larger than the actual dimensional ratio in order to make the present invention easier to understand and for convenience in drawing. (The same applies to FIG. 14 described above).

1. 1. About the stairs 1 provided with the tread plate 10, FIG. 1 is a schematic perspective view of the stairs 1 provided with the tread plate 10 according to the embodiment of the present invention. As shown in FIG. 1, the staircase 1 is installed in a building such as a house, and has a plurality of tread plates 10, 10, ... And risers 18, 18, ..., And a pair of side plates for fixing them. It has 17, 17 and so on. Specifically, tread plates 10 having a required number of steps to be treads are attached in a horizontal posture between the left and right side plates 17 and 17 in a stepped manner at predetermined intervals in the vertical and front-rear directions. A riser plate 18 is arranged between the ten.

Three grooves 15 are formed on the tread surface (upper surface) of the tread plate 10 to improve the visibility of the nose 16 and prevent slipping. The upper portion of the riser plate 18 is inserted into a portion of the upper tread plate 10 that is recessed by a predetermined distance from the front end surface (step nose 16 side) on the back surface side, and the lower portion thereof abuts on the rear end surface of the lower tread plate 80. There is.

In the present embodiment, the tread surface of the tread plate 10 including the groove 15 is provided with a printed pattern described later, and if necessary, the printed pattern is also printed on the front surface of the nose 16 and the back surface of the tread plate 10 described later. It has been subjected. Hereinafter, the manufacturing method of the tread plate 10 will be described with reference to FIGS. 3 to 13 with reference to the flow chart shown in FIG. 2 and each step shown in the flow chart.

2. Preparation step S1 (FIG. 3) First, the preparation step S1 shown in FIG. 2 is performed. In the preparation step S1, as shown in FIG. 3A, the surface of the decorative material 12 is formed by adhering the decorative material 12 and the side decorative material 13 to the wood-based base material 11 with an adhesive or the like, if necessary. Prepare a tread plate 10 serving as a tread surface.

Here, the wood-based base material 11 is one in which the underlayers 11b and 11c are bonded to both sides of the base material layer 11a. In the present embodiment, the base material layer 11a is made of plywood, and the underlaying 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 of, for example, only the base material layer. In addition to the above-mentioned materials, the base material layer and the underlaying layer include solid wood, particle board (PB), wood fiber board (insulation board, hard board, etc.), and oriented strand board (OSB). , LVL, laminated lumber, or laminated materials thereof.

As described above, the decorative material 12 is further bonded to the surface of the wood-based base material 11, and the surface of the decorative material 12 serves as the tread surface of the tread plate 10. Further, in the present embodiment, the side decorative material 13 is attached to the front side surface corresponding to the nose of the tread plate, if necessary. In the present embodiment, as the decorative material 12 and the side decorative material 13, for example, a decorative single plate such as a veneer having a thickness of about 0.1 to 1.0 mm is used.

Further, 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 described later, and the decorative material 12 is not limited to a wood-based material, for example, a resin made of a thermoplastic resin or the like. Examples thereof include sheets, paper materials such as kraft paper, impregnated paper in which kraft paper is impregnated with melamine resin, and wood-based decorative single plates. Examples of decorative veneers include beach, oak, maple, zelkova, walnut, cinnamon, oak, ash, kiri, hinoki, sugi, mahogany, teak, rosewood, tochi, black oyster, ash, elm, hippopotamus, and rosewood. Alternatively, ebony and the like can be mentioned.

3. 3. About the 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 groove carving machine is used to form three grooves 15 that cross the tread surface in the left-right direction on the step nose 16 side of the tread surface of the tread plate 10. .. The groove 15 is intended to improve the visibility of the tread plate and prevent slipping, and has a V-shaped cross section and a depth of about 1.2 to 2.0 mm. Here, if the groove 15 is buried in a resin or the like before the protective layer forming step S8 described later, the groove 15 does not function as a non-slip. Therefore, here, the groove 15 is the underlaying layer of the wood-based base material 11. It has been carved down to 11b.

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

4. About the coating process S3 (FIG. 5) Next, the coating process 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, the 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. As a result, the coating layer (colored layer) 21 is formed on the tread surface including the wall surface of the groove 15. The 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 shine in the printing step S6 described later. For example, the color of the water-based paint is white. , Brown and other colors can be mentioned.

As the coating apparatus, for example, a roll coater 40 as shown in FIG. 11 can be used so that the coating can be applied even in the groove 15. The roll coater 40 includes a sponge coating roll 41, a pickup roll 42, and a backup roll 43 on the outer periphery thereof, and the water-based paint is temporarily stored on the upper side of the coating roll 41 and the backup roll 43 and sent out from between the two rolls. Therefore, it is applied to the tread surface of the tread plate 10 that moves from the left to the right in the figure.

Although the coating step S3 is included in the present embodiment, the coating step S3 may be omitted and the process may proceed to the receiving layer forming step S4 if the printed pattern can be seen in the printing step S6 described later.

5. Regarding the 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 in which the coating layer 21 is formed is coated with an ultraviolet curable resin in an uncured state, and the uncured receiving layer 22A is provided. Form. Here, in order to coat the tread surface with the ultraviolet 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 “acceptance” referred to in the present specification is a layer that accepts ink in order to stabilize the fixing of the ink in the printing step S6 described later.

The ultraviolet curable resin forming the uncured receiving layer 22A is generally known and contains a resin such as a reactive oligomer and a reactive monomer, a photopolymerization initiator and the like. When the ultraviolet curable resin is irradiated with ultraviolet rays, these resins are cured by a polymerization reaction and a cross-linking reaction, and the uncured ultraviolet curable resin is cured.

For example, if the coating layer 21 is not formed, examples of the ultraviolet curable monomer and oligomer include urethane acrylate, acrylic resin acrylate, epoxy acrylate, and polyester acrylate. Here, in the present embodiment, since the coating layer 21 is provided in the coating step S3, among these resins, a resin having light transmission is preferable.

When the surface of the wood-based decorative veneer is used as the decorative material 12, the surface of the wood-based decorative veneer may become fluffy 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 fluffy surface, the fluffy surface can suppress the influence on the adhesion of ink in the subsequent printing step S6.

6. Regarding the 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, ultraviolet rays (UV) are uncured on the tread surface of the tread plate 10 on which the uncured receiving layer 22A is formed by using the line type UV irradiator 50. The first semi-cured receiving layer 22B is obtained by irradiating the receiving layer 22A by adjusting the irradiation amount 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 irradiation amount of ultraviolet rays (UV) (= UV exposure amount / integrated light amount), for example, 500 mJ / cm. It is preferably ^{2 or less.} The UV irradiation amount (unit: mJ / cm ² ) is determined by UV illuminance (unit: mW / cm ² ) x irradiation time (unit: seconds). Therefore, by setting the UV illuminance and / or irradiation time to be lower and / or shorter than when the uncured receiving layer 22A is completely cured, the first semi-cured receiving layer 22B which is not completely cured can be obtained. Can be done. As the UV irradiation amount and irradiation mode here, those derived from a large number of prototype experiments and the like are selected.

7. 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, an ultraviolet curable ink is adhered to the surface of the first semi-cured receiving layer 22B in an uncured state by inkjet printing to print a pattern such as wood grain. do. In this state, the print layer 23A (specifically, the adhered ink) is uncured.

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

Inkjet printing is performed by an inkjet printer. The inkjet printer includes a head that houses ink used for general printing and individually ejects each ink according to a predetermined pattern such as a grain of wood to be printed, and a feeder that feeds a tread plate 10. The inkjet printer feeds the tread plate 10 with a feeder while injecting each ink with the head from a direction substantially orthogonal to the tread surface of the tread plate 10 according to a pattern such as wood grain, and the tread surface (first semi-cured receiving layer). A pattern such as wood grain is printed on (22B) to obtain an uncured printed layer 23A. The uncured print layer 23A has granular ink adhered to it, and in the present embodiment, the surface of the first semi-cured receiving layer 22B is exposed between the adhered granular ink. ing.

In this way, in the first curing step S5, the ultraviolet curable ink is adhered to the first semi-cured receiving layer 22B, which has not been completely cured by ultraviolet rays, in an uncured state by inkjet printing. Therefore, the adhesiveness 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 ultraviolet curable resin by irradiation with ultraviolet rays are not completely completed, so that the resin of the first semi-cured receiving layer 22B and the uncured resin are not cured. It is considered that this is because the ultraviolet curable ink (resin) has a high affinity and these are easily chemically adhered. 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 agglomerating. As a result, by improving the fixability of the ink in the tread surface, particularly in the groove 15, it is possible to suppress blurring of the printed pattern.

8. Regarding the 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 by using the line type UV irradiator 50, and the first semi-curing is performed. 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 present embodiment, the UV irradiation amount (UV irradiation amount) so that the ink (uncured print layer 23A) and the first semi-cured receiving layer 22B are not completely cured even in the second curing step S7. UV illuminance and / or irradiation time) is adjusted to irradiate the tread surface with ultraviolet rays. As a result, the uncured print layer 23A is further cured than the semi-cured print layer 23B in which the uncured print layer 23A is not completely cured and the first semi-cured receiving layer 22B obtained in the first curing step S5, and this is not completely cured. 2 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 printed layer 23A) and the first semi-cured receiving layer 22B, The polymerization reaction and the cross-linking reaction are promoted. 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 groove 15 on the tread surface can be improved, and the peeling of the printed pattern including the vicinity of the groove 15 can be reduced.

In this embodiment, the semi-cured printing layer 23B and the second semi-cured receiving layer 22C are formed in order to perform the protective layer forming step S8 described later. For example, the protective layer 24 described later is formed on the tread plate 10. (That is, the protective layer forming step S8 is not performed), the ink (uncured print layer 23A) adhering to the first semi-cured receiving layer 22B is completely cured by irradiating with ultraviolet rays. , The first semi-cured receiving layer 22B may be completely cured. The term "completely cured" as used herein means a state in which the hardness of the ultraviolet curable resin does not become higher even when irradiated with ultraviolet rays.

9. About the 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 through which visible light is transmitted is applied to the tread surface on which the second semi-curing receiving layer 22C and the semi-curing printing layer 23B (see FIG. 9) are formed. It is coated in an uncured state to form an uncured protective layer 24A. In forming the uncured protective layer 24A, a roll coater having the same structure 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 resin exemplified in the receiving layer forming step S4 described above, and by forming the protective layer 24 with this, the resistance of the tread surface of the tread plate 10 is increased. Abrasion resistance, water resistance, heat resistance, etc. are improved. 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 the uncured protective layer 24A is formed, the resins of the second semi-cured receiving layer 22C and the semi-cured printing layer 23B are in a semi-cured state in which they are not completely cured by irradiation with ultraviolet rays. be. Therefore, when the ultraviolet curable resin is coated in an uncured state to form the uncured protective layer 24A, the second semi-cured receiving layer 22C, the semi-cured printing layer 23B, and the uncured protective layer 24A are formed. Adhesion can be improved.

This is because the second semi-cured receiving layer 22C and the semi-cured printing layer 23B are not sufficiently cured (because they are not completely completed) because the polymerization reaction and the cross-linking reaction of the ultraviolet curable resin by irradiation with ultraviolet rays are not sufficient. It is considered that the uncured ultraviolet curable resin of the protective layer 24A of the above is easily chemically adhered to these.

10. Regarding the 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 tread surface on which the uncured protective layer 24A is formed is irradiated with ultraviolet rays with a predetermined irradiation amount by using the line type UV irradiator 50. The uncured protective layer 24A is cured, and the ink (semi-cured printing layer 23B) and the second semi-cured receiving layer 22C (see FIG. 10) are further cured to completely cure the protective layer 24 and the printing layer. A decorative layer 20 composed of 23 and a receiving layer 22 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 printing layer 23B), the second semi-cured receiving layer 22C, and the uncured surface are uncured. Since the polymerization reaction and the cross-linking reaction are also promoted 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. Thereby, the protective layer 24 that is hard to be peeled off from the tread surface can be formed.

11-1. About additional step 1 (printing of step nose, etc.) Further, as additional step 1, the back surface of the tread plate 10 may be printed as follows. Specifically, in the preparation 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 bonded side surface 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. Then, in the printing step S6, an uncured print layer is formed, and then in the second curing step S7, the first semi-cured receiving layer and the uncured printed layer are completely cured.

As a result, as shown in FIG. 13, a decorative layer 31 composed of a receiving layer and a printing layer can be obtained. In this way, a pattern such as a wood grain can be formed on the step nose 16 to which the side decorative material 13 is attached in accordance with the step on the tread surface.

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

11-2. Additional step 2 (printing on the back surface, etc.) Further, as an additional step 2, the back surface of the tread plate 10 may be printed as follows. First, in the painting step S3, painting is performed on the portion of the back surface of the tread plate 10 from the nose 16 to at least the position where the riser plate 18 is arranged. Next, the receiving layer is not formed on the back surface, and in the printing step S6, the ultraviolet curable ink is adhered to the painted back surface in an uncured state by inkjet printing to print a predetermined pattern. In the second curing step S7, the printed back surface is irradiated with ultraviolet rays to completely cure the ink on the back surface of the tread plate.

As a result, as shown in FIG. 13, the decorative layer 32 composed of the paint layer and the print layer can be formed. In this way, since the decorative layer 32 having a pattern such as wood grain is formed on the back surface of the tread plate 10 from the nose 16 to at least the riser plate 18, the appearance of the tread plate 10 seen from below the stairs 1 can be enhanced. ..

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

Next, using a printing device equipped with an inkjet head (manufactured by Kyocera) on the surface of this semi-cured receiving layer, a four-color ultraviolet curable type containing four colorants of yellow, magenta, cyan, and black. An uncured print layer was formed using ink (acrylic synthetic resin: manufactured by DIC). Then, the semi-cured receiving layer and the uncured printed layer were irradiated with ultraviolet rays at an irradiation amount of ^{120 mJ / cm 2 so as to be completely cured.}

(Comparison 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 an irradiation amount of ^{500 mJ / cm 2 to form a completely cured receiving layer.} Next, an uncured print layer similar to that in Example 1 was formed on the surface of this receiving layer. Then, ultraviolet rays were irradiated at an irradiation amount of ^{90 mJ / cm 2} so that the uncured print layer was completely cured.

<Peeling test>
With a cutter knife, 11 squares were formed in each of the vertical and horizontal directions so that 10 × 10 squares were formed on the surface on which the printed layer of the treads of Examples and Comparative Examples was formed. I made a notch. Next, an adhesive tape was attached to the entire surface of the print layer divided into 100 squares, and the adhesive tape was peeled off to confirm the number of peeled print layers.

As a result, in the example, all 100 print layers were not peeled off, but in the comparative example, 13 out of 100 print layers were found to be peeled off. This is because, in the example, the uncured printed layer was formed on the semi-cured receiving layer, so that when the semi-cured receiving layer and the uncured printed layer were irradiated with ultraviolet rays, they were polymerized between them. It is considered that the reaction and the cross-linking reaction occurred and the fixability of the print layer was improved.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various types are described within the scope of the claims as long as the spirit of the present invention is not deviated. It is possible to make design changes.

10: Tread board, 11: Wood-based base material, 11a: Base material layer, 11b, 11c: Underlay layer, 12: Decorative material, 15: Groove, 20: Decorative layer, 21: Coating layer, 22: Accepting layer, 22A : Uncured receiving layer, 22B: First semi-cured receiving layer, 22C: Second semi-cured receiving layer, 23: Printing layer, 23A: Uncured printing layer, 23B: Semi-curing printing layer, 24: Protective layer, 24A : Uncured protective layer

Claims (5)

A preparatory step of preparing a tread plate on which the surface of the decorative material serves as a tread surface by adhering a decorative material to a wood-based base material, and
A groove forming step of forming a groove on the tread surface side of the tread plate, and
A receiving layer forming step of coating the tread surface including the wall surface of the groove with an ultraviolet curable resin in an uncured state to form an uncured receiving layer.
The first curing step of obtaining a semi-cured receiving layer by irradiating the tread surface of the tread plate on which the uncured receiving layer is formed with ultraviolet rays so that the uncured receiving layer is not completely cured.
A printing step in which an ultraviolet curable ink is adhered to the surface of the semi-cured receiving layer in an uncured state by inkjet printing, and a predetermined pattern is printed on the surface of the semi-cured receiving layer.
A second curing step of irradiating the tread surface on which the predetermined pattern is printed with ultraviolet rays to cure the ink adhering to the semi-cured receiving layer and further curing the semi-cured receiving layer.
A method for manufacturing a tread plate, which comprises. In the second curing step, ultraviolet rays are irradiated so that the ink and the semi-cured receiving layer are not completely cured.
After the second curing step, the tread surface is coated with an ultraviolet curable resin through which visible light is transmitted in an uncured state to form a protective layer.
A third curing step in which the protective layer is cured by irradiating the tread surface on which the protective layer is formed with ultraviolet rays, and the ink and the semi-cured receiving layer are further cured.
The method for manufacturing a tread plate according to claim 1, wherein the tread plate comprises. In the preparatory step, a wood-based decorative veneer is attached to the wood-based base material as the decorative material.
After the groove forming step and before the receiving layer forming step, the tread surface including the wall surface of the groove is coated with the water-based paint and then dried to dry the tread surface including the wall surface of the groove. The method for manufacturing a tread plate according to claim 1 or 2, further comprising a painting step of painting. In the preparatory step, a decorative material for the side surface is further attached to the front side surface corresponding to the nose of the tread plate.
The method for manufacturing a tread plate according to claim 3, wherein a series of steps from the receiving layer forming step to the second curing step is performed on the surface of the side surface decorative material. In the painting step, painting is performed on the back surface of the tread plate from the nose to at least the position where the riser plate is arranged.
In the printing step, an ultraviolet curable ink is adhered to the painted back surface in an uncured state by inkjet printing to print a predetermined pattern.
The method for manufacturing a tread plate according to claim 3 or 4, wherein in the second curing step, the ink on the back surface of the tread plate is cured by irradiating the printed back surface with ultraviolet rays. ..

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