TWI694869B - A method of manufacturing a decorative building board - Google Patents

Abstract

The object of the present invention is to provide a method for manufacturing a decorative building board with high design, in which when the inkjet printing is performed on a metal wall plate using active light-curing ink, the uniform wetting and diffusion of the ink can be confirmed .

In order to achieve the above object, the present invention provides a method for manufacturing a decorative building board, which includes: performing flame treatment on a metal wall plate under specific conditions, and performing inkjet printing using active light-curing printing ink.

Description

Manufacturing method of decorative building board

The invention relates to a method for manufacturing a decorative building board. Before printing a pattern on the surface of a metal-based substrate of a metal wall plate used in the technical field of building materials by flame-printing, flame treatment is performed under specific conditions.

In recent years, inkjet printing can form a variety of patterns on a substrate simply and inexpensively, so inkjet is used in various fields.

For example, Patent Document 1 and Patent Document 2 disclose a coated steel sheet having a metal-based substrate, an ink-receiving layer containing polyester, and an ink layer. When manufacturing such coated steel plates, inkjet printing solvent-based ink is applied to the surface of the ink-receiving layer formed on the metal substrate, thereby forming an ink layer. At this time, the organic solvent contained in the solvent-based ink dissolves a part of the surface of the ink-receiving layer and the surface becomes rough. Therefore, the solvent-based ink can wet and diffuse the ink and adhere to the ink-receiving layer.

In addition, Patent Document 3 and Patent Document 4 describe a coated steel sheet for building boards, which has a metal-based substrate, an ink-receiving layer formed by applying a shrinkage coating and hardening, and an ink layer. When manufacturing such coated steel plates, a solvent-based or water-based ink is printed on the surface of the ink-receiving layer formed on the substrate to form an ink layer. At this time, the ink is diffused in the groove on the surface of the ink receiving layer by capillary phenomenon, so it can be sufficiently wetted and diffused.

Regarding inkjet printing, in addition to the solvent-based printing ink described above, Patent Document 5 discloses an image forming method using an active light-curable printing ink that can stably reproduce high-definition images on a variety of recording materials. In addition, Reference Document 6 discloses a method for manufacturing a decorative building board, which uses active light-curing ink for inkjet printing on a metal-based wall board.

On the other hand, Patent Document 7 also discloses a method for manufacturing decorative building boards such as exterior materials. Specifically, a polar group is introduced on the surface of the water-based enamel coating film provided on the substrate by flame treatment to improve the water system. Wettability of inkjet printing ink and water-based coating film.

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2000-107683.

Patent Document 2: Japanese Patent Laid-Open No. 2008-272953.

Patent Document 3: Japanese Patent Laid-Open No. 2008-036549.

Patent Document 4: Japanese Patent Laid-Open No. 2008-068453.

Patent Document 5: Japanese Patent No. 4539104.

Patent Literature 6: Japanese Patent No. 5597296.

Patent Document 7: Japanese Patent Laid-Open No. 2009-107298.

As shown in FIG. 1, the metal wall plate 1 of the present invention is composed of a metal-based substrate 11 having a concave-convex pattern with a height d of 0.5 mm or more, a core material 12 and a back material 13. Furthermore, an ink-receiving layer 14 is formed on the metal-based substrate 11. In addition, a chemical conversion coating film or a primer coating film may be provided on the metal-based substrate 11, and the ink receiving layer 14 may be formed on the chemical conversion coating film or the primer coating film.

The ink-receiving layer 14 is formed by applying a resin composition containing a resin and a pigment as a coating material to a metal-based substrate and drying (or curing). Thereafter, the metal-based substrate is subjected to embossing, drawing forming, etc., and uneven processing such as tile style, brick style, and wood grain style is performed. Furthermore, for the purpose of improving heat insulation or sound insulation, a synthetic resin foam or the like is used as the core material 12, and the back surface of the metal-based substrate is coated with a back material 13 such as aluminum laminated kraft paper.

When the solvent-based printing ink was used for the inkjet printing of the metal wall plate 1 thus formed, no problem was recognized in terms of design. However, in the case of inkjet printing using active light-curable ink, the uniform wetting and spreading of the ink cannot be confirmed, which causes problems in the design of the printed image.

The inventors of the present invention have made intensive studies on the above-mentioned problems, and as a result, it has been found that the reason for preventing the uniform wetting and spreading of the active light-curable printing ink is that dirt (foreign matter) when the metal wall plate 1 is manufactured adheres to the ink receiving layer 14. The metal-based base material 11 of the metal wall panel 1 is formed after the ink-receiving layer 14 is coated, and is coated on the back side with a synthetic resin foam of the core material 12 or the like. In these multiple processing steps, the manufacturing machine is in contact with the metal wall plate 1, the resin and additives from the ink receiving layer and core material are attached to the manufacturing and processing machine, and the resin and additives are attached to the subsequent batch of ink receiving The layer 14 becomes the dirt of the ink receiving layer 14.

In inkjet printing using solvent-based ink, the organic solvent contained in the solvent-based ink dissolves part of the surface of the ink-receiving layer and the surface becomes rough, so even if a little dirt adheres to the ink-receiving layer Big impact. However, in the case of active light-curable printing inks, since the ink receiving layer is impermeable, the wettability of the printing ink is greatly reduced due to dirt. Furthermore, the ink-receiving layer is impermeable to the ink can be confirmed by the following way: the cross-section of the ink-receiving layer and the ink layer is observed under a microscope at a magnification of 100 times to 200 times.

Therefore, the inventors of the present invention burned and removed the dirt adhering to the ink receiving layer 14 by subjecting the metal wall plate 1 to flame treatment under specific conditions, thereby achieving uniform wetting and diffusion of the active light-curable ink.

Specifically, the present invention is a method for manufacturing a decorative building board, including: a metal wall plate, including a metal-based substrate, a core material, and a back surface material forming a concave-convex pattern with a height difference of 0.5 mm or more, and the substrate The ink receiving layer formed by the resin composition is arranged on the metal wall plate, and the flame of the flame port of the burner is irradiated from 250kJ/hour to 12000kJ/hour per 10mm for the metal wall plate, and the surface temperature of the substrate is not After flame treatment at a temperature exceeding 300°C, inkjet printing is performed using active light-curing ink.

In the present invention, the surface of the metal wall plate is subjected to flame treatment before inkjet printing to remove dirt, thereby obtaining homogeneous wetting and diffusion of active light-curing printing ink, and obtaining a decorative building board with high design. Furthermore, the conditions of the flame treatment are adjusted so that the temperature of the metal base material of the metal wall plate during the flame treatment becomes 300°C or less, thereby preventing peeling caused by thermal strain at the interface between the core material and the metal base material.

1‧‧‧Metal wall plate

1-1‧‧‧Printed side

2‧‧‧Burner

3‧‧‧ Flame

4‧‧‧Conveyor

4-1‧‧‧Transport surface

5‧‧‧Inkjet coating machine

8‧‧‧Control Department

9‧‧‧ Active light irradiation machine

11‧‧‧Metal base material

12‧‧‧Core material

13‧‧‧Back material

14‧‧‧Ink receiving layer

21‧‧‧flame mouth

22‧‧‧Burner head

61‧‧‧ inkjet recording head (yellow)

62‧‧‧Inkjet recording head (cyan)

63‧‧‧Inkjet recording head (magenta)

64‧‧‧Inkjet recording head (black)

71‧‧‧Ink supply tank (yellow)

72‧‧‧Ink supply tank (cyan)

73‧‧‧Ink supply tank (magenta)

74‧‧‧Ink supply tank (black)

101‧‧‧Hot melt adhesive

102‧‧‧Wood chips

103‧‧‧Stretching fixture

d‧‧‧(The unevenness of the metal base material) height difference

H‧‧‧ (the shortest distance between the burner and the printing surface)

L‧‧‧(the direction parallel to the conveying direction in the flame port of the burner) length

M‧‧‧line inkjet recording device

W‧‧‧ (of the flame port of the burner) width

W'‧‧‧ (10mm burner flame port) width

FIG. 1 is a diagram showing an aspect of performing flame treatment on a metal wall plate 1 used in the present invention.

FIG. 2 is a diagram showing a cross section of the metal wall plate 1 used in the present invention.

Fig. 3 shows an example of a line-type inkjet recording apparatus used to implement the present invention.

Fig. 4 is a schematic front view showing a burner head used in a burner embodying the present invention.

5 is a schematic diagram of a method for measuring the adhesive strength of a metal-based substrate and a core material (synthetic resin foam) in Examples.

The decorative building board manufactured by the present invention is obtained by flame-treating the surface of the metal wall plate 1 shown in FIG. 1 under specific conditions, and performing inkjet printing using active light-curing printing ink .

Here, as shown in FIG. 2, the metal wall plate 1 includes a metal-based base material 11, a core material 12, a back surface material 13, and an ink-receiving layer 14.

As the metal-based substrate 11, a metal plate generally used as a metal wall plate can be used. As specific metal plates, there may be mentioned plated steel plates such as molten zinc (Zn)-55% aluminum (Al) alloy plated steel plates, steel plates such as ordinary steel plates or stainless steel plates, aluminum plates and copper plates. For these metal plates, embossing or deep drawing forming, which are common in the technical field, are performed, and uneven processing such as tile style, brick style, and wood grain style is carried out.

Furthermore, it is possible to form a chemical conversion treatment film or a primer coating film on the surface of the metal-based substrate used in the invention within a range that does not hinder the effect of the invention.

In addition, the thickness of the metal-based substrate 11 is not particularly limited, but is usually 0.15 mm to 0.5 mm.

In addition, as shown in FIG. 1, the metal-based base material 11 of the present invention has an uneven pattern with a height difference of 0.5 mm or more. Here, the “concavo-convex pattern with a height difference of 0.5 mm or more” means that the metal-based substrate 1 has at least one concavo-convex pattern having a height difference d of 0.5 mm or more, and the irregularities constitute a pattern. Therefore, there may be irregularities with a height difference of less than 0.5 mm, and these irregularities may also be combined to form a metal-based substrate into a tile-like or woodgrain-like pattern.

Furthermore, it is difficult to form a highly designed pattern even if the pattern is formed only by irregularities with a height difference d less than 0.5 mm. In addition, regarding the height difference d, the thickness of the ink-receiving layer 14 should also be considered. However, as described below, since the thickness of the ink-receiving layer 14 is usually in the range of 3 μm to 30 μm, the ink-receiving layer 14 may not be considered. thickness.

In addition, since a pattern with higher designability is formed, it is preferable to form irregularities on the metal wall plate 1 with a height difference d of 1.0 mm or more, and more preferably 1.5 mm or more.

In addition, as long as the effect of the present invention can be exerted, the upper limit of the height difference of the metal-based substrate is not particularly limited, and generally the height difference d of the unevenness of the metal-based substrate is 7 mm or less, preferably 5 mm or less. The reason is that if the height difference of the unevenness of the metal-based substrate is at most 7 mm, a pattern having sufficient designability as a metal wall plate can be formed. In addition, if the height difference of the unevenness of the metal-based substrate exceeds 7 mm, it may be difficult to remove the foreign matter by irradiating the foreign matter present in the concave portion with flame.

On the other hand, even if the height difference d of the unevenness is 1.5 mm at the maximum, a pattern can be formed, so the maximum value of the height difference d can also be 1.5 mm or less.

The core material 12 is formed of a synthetic resin foam. Examples of synthetic resin foams include polyurethane foams, polyisocyanurate foams, phenol resin foams, vinyl chloride resin foams, polyethylene foams, and polystyrene foams. , Urea resin foam, etc. In addition, the core material 12 may also use inorganic materials such as rock wool, glass wool, ceramic wool, and the like.

The back material 13 can also be used by laminating one or more of the following, that is, aluminum vapor-deposited paper, kraft paper, asphalt felt, metal foil (aluminum, iron (Fe), lead (Pb), (Copper (Cu), etc. foil), synthetic resin sheet, rubber sheet, cloth sheet, gypsum paper, aluminum hydroxide paper, glass fiber cloth, glass fiber non-woven fabric, etc.; or by the waterproof, flame-retardant treatment of the sheet Constructor.

In addition, there is a fitting portion for interconnection on the metal wall plate, and it is usually made by bending both ends of the metal-based substrate in the width direction to form a male and female structure.

The ink receiving layer 14 used in the present invention may be a coating film formed by hardening the resin composition. Here, a resin that is generally used as a polymer compound that can form a coating film on the above-mentioned substrate can be used. Examples thereof include polymer compounds such as polyester resins, acrylic resins, polyvinylidene fluoride resins, polyurethane resins, epoxy resins, polyvinyl alcohol resins, and phenol resins. Among them, the polymer compound used in the present invention is preferably a polyester resin or an acrylic resin in terms of high weather resistance and excellent adhesion to printing ink.

Furthermore, it is preferable not to use the coating material that forms the porous ink-receiving layer used as the ink-receiving layer of the previous water-based ink. Such porous ink-receiving layers sometimes have problems in water resistance and weather resistance, and sometimes are not suitable for use in building materials.

A hardener may be used in the above-mentioned polymer compound resin to adjust the properties or physical properties of the resin. When using a polyester resin, it is preferable to use a melamine-based hardener (melamine resin hardener). For example, methylated melamine (hydroxymethylmelamine methyl ether), n-butylated melamine (hydroxymethylmelamine butyl ether), mixed etherified melamine of methyl and n-butyl, etc. are mentioned. For the ink-receiving layer whose crosslinking density is increased by using such a hardener, non-aqueous ink does not penetrate, so it is excellent in water resistance and weather resistance, so it is particularly preferable. The ink-receiving layer is impermeable to the active light-curable ink, which can be confirmed by the following method: the cross-section of the ink-receiving layer and the ink layer is observed under a microscope at a magnification of 100 times to 200 times. When the ink receiving layer is non-permeable, the interface between the ink receiving layer and the ink layer can be clearly identified, but when the ink receiving layer is permeable, the interface becomes unclear and difficult to identify .

In the case of using a polyester resin as the polymer compound, the molecular weight of the polyester resin is preferably a number average molecular weight of 2,000 to 8,000 when measured by GPC (gel permeation chromatography; gel permeation chromatography). If the molecular weight is less than 2,000, the processability may be reduced and the coating film may be easily broken. In addition, if the molecular weight is more than 8,000, the weather resistance may be reduced due to a decrease in crosslink density. In terms of the balance between processability and weather resistance, the number average molecular weight is particularly preferably 3,000 to 6,000.

The ink receiving layer 14 of the present invention may also contain organic solid particles or inorganic solid particles. The average particle diameter of the particles is 4 μm to 80 μm, preferably 10 μm to 60 μm.

Examples of the inorganic particles include silicon dioxide, barium sulfate, talc, calcium carbonate, mica, glass beads, and glass flakes. In addition, examples of the organic particles include acrylic resin beads and polyacrylonitrile resin beads. These resin beads can be manufactured using a well-known method, and can also use a commercial item. Examples of commercially available acrylic resin beads include: "TAFTIC AR650S (average particle size 18μm)", "TAFTIC AR650M (average particle size 30μm)", "TAFTIC AR650MX (average particle size 40μm)", "TAFTIC AR650MZ (average particle size 60 μm)", "TAFTIC AR650ML (average particle size 80 μm)", "TAFTIC AR650L (average particle size 100 μm)" and "TAFTIC AR650LL (average particle size 150 μm)". In addition, examples of commercially available polyacrylonitrile beads include: "TAFTIC A-20 (average particle size 24 μm)", "TAFTIC YK-30 (average particle size 33 μm)", "TAFTIC YK-50" (Average particle size 50 μm)” and “TAFTIC YK-80 (average particle size 80 μm)”.

The content of organic particles and inorganic particles at this time is usually 2% by mass to 40% by mass of the coating film, and preferably 10% by mass to 30% by mass.

The average particle size of the solid particles or coloring pigment is determined by the Coulter counter method.

Furthermore, the ink receiving layer 14 may contain a color pigment. At this time, the average particle diameter of the coloring pigment is usually 0.2 μm to 2.0 μm. Examples of such coloring pigments include titanium oxide, iron oxide, yellow iron oxide, phthalocyanine blue, carbon black, and cobalt blue. In the case of adding a color pigment, it is usually added to the paint in such a manner as to become 40% by mass to 60% by mass of the coating film.

The film thickness of the ink-receiving layer 14 is not particularly limited, but is usually in the range of 3 μm to 30 μm. When the coating film is too thin, the durability and concealment of the coating film may be insufficient. On the other hand, when the coating film is too thick, the manufacturing cost may increase, and swelling may easily occur during baking.

The active light-curable printing ink of the present invention uses the printing ink generally used in the technical field, and either of the radical polymerization type printing ink and the cation polymerization type printing ink exists in the technical field, and any one may be used.

Activated light-curing inks usually contain monomers or oligomers, photopolymerization initiators, colored materials, dispersants, surfactants, and other additives. In the present invention, materials generally used in this technical field are used. Compared with the radical polymerization type ink, the cationic polymerization type ink has less volume shrinkage, and it can also obtain high adhesion for the non-permeable ink receiving layer which improves the cross-linking density, so it is particularly preferable.

An embodiment of the present invention will be described with reference to FIG. 3. In this embodiment, the burner 2 is used for the flame treatment of the metal wall plate 1. In addition, the inkjet recording device used is a linear inkjet recording device M capable of performing four-color inkjet printing of four-color inks (yellow, cyan, magenta, black). In addition, the ink used is active light-curing ink.

In FIG. 3, the line-type inkjet recording apparatus M includes an inkjet coating machine 5 and a conveyor 4. The inkjet coating machine 5 includes an inkjet recording head 6 (61 to 64), and a printer connected to the recording head Ink supply tank 7 (71 to 74) and printing control system 8. Furthermore, the linear inkjet recording device M is provided with a burner 2 for performing flame treatment and an active light irradiator 9. Furthermore, the metal wall plate 1 is transported in the direction of the dotted arrow in FIG. 3.

The printing surface (ink receiving surface) 1-1 of the metal wall plate 1 is the surface on the opposite side to the surface in contact with the conveying surface 4-1 of the conveyor 4. The active light-curing ink ejected from the inkjet recording head is colored on the printing surface, and a desired image can be formed on the ink receiving layer 14.

As shown in FIG. 3, the printing surface 1-1 of the metal wall plate 1 is subjected to flame treatment by the flame ejected from the burner 2 before inkjet printing.

Fig. 1 shows a specific aspect of the flame treatment. The burner 2 includes a flame port 21 that emits flames, and a burner head 22. Furthermore, the length L of the flame port 21 can be changed in a direction parallel to the conveyance direction (dashed arrow) in FIG. 1. Usually, L is 3mm to 40mm. Furthermore, if the conveying speed of the metal wall plate 1 increases, an air flow will be generated as the metal wall plate 1 moves. The smaller the value of L, the more easily the flame 3 of the burner is affected by the airflow, so the flame 3 may not be uniformly irradiated. Therefore, it is preferable to adjust L and the conveying speed in consideration of the optimal conditions.

The burner 2 is set at a distance H from the printing surface 1-1 of the metal wall plate 1. H means the shortest distance of the burner 2 from the printing surface 1-1. That is, H usually indicates the distance between the burner head 5 and the printing surface 1-1, but the distance between the flame port 21 and the printing surface 1-1 is lower than that of the burner head 22 and the printing under the structure that the flame port 21 protrudes from the burner head 22 When the distance between the surface 1-1 is close, H represents the distance between the flame port 21 and the printing surface 1-1.

Generally, the distance H is set so as to be in a range of 10 mm to 120 mm, preferably 25 mm to 100 mm, further preferably 30 mm to 90 mm, and most preferably 40 mm to 80 mm. The metal-based substrate 11 of the metal wall panel 1 is subjected to forming processing such as embossing or deep drawing. Therefore, the metal base material 11 may be warped. If the aforementioned distance H is less than 10 mm, the burner 2 may come into contact with the metal wall plate 1 due to the warpage of the metal-based substrate. Furthermore, since the metal wall plate 1 is used as a building board, the length of the metal-based substrate 11 may sometimes extend over several meters (3 m to 4 m), and the metal-based substrate 11 may be warped by 10 mm to 20 mm. Therefore, regarding the distance H, the distance H must be adjusted according to the length of the metal-based substrate 11, that is, the length of the metal wall plate 1.

In addition, if the distance H exceeds 120 mm, a high-energy flame must be irradiated in order to achieve the effect of flame treatment, which is inefficient and poor. In addition, even if the output of the burner is the burner, the width of the flame port is 12000 kJ per 10 mm. /Hours cannot remove foreign objects sufficiently.

The output of the burner is the width of the flame port of the burner per 10 mm of 250 kJ/hour to 12000 kJ/hour, preferably 400 kJ/hour to 7500 kJ/hour, further preferably 600 kJ/hour to 5000 kJ/hour, and more preferably Output from 1200kJ/hour to 5000kJ/hour. If the width of the flame port of the burner does not reach 250 kJ/hour per 10 mm, the flame is weak, and therefore the dirt (foreign matter) present on the surface of the metal wall plate 1 cannot be sufficiently burned off, and the removal of the dirt becomes insufficient. As a result, the homogeneous wetting and diffusion of the active light-curable printing ink in the ink receiving layer cannot be obtained. In addition, if the width of the flame port of the burner exceeds 12000 kJ/hour for every 10 mm, the surface temperature of the metal-based substrate 11 rapidly exceeds 300° C. Therefore, thermal strain occurs at the interface between the core material 12 and the metal-based substrate 11 The core material 12 and the metal base material 11 are peeled off. In addition, considering the heat storage properties of the metal-based substrate 11, it is preferably 250° C. or lower.

Furthermore, the surface temperature of the metal-based substrate 11 is a portion where the tip of the thermocouple of a thermocouple thermometer (type K) is welded to the ink-receiving layer 14 of the metal wall plate 1 and removed with a file, etc., on the metal wall plate 1 Any position of the printing surface is measured.

In addition, FIG. 4 is a front view of the burner 2 of FIG. 2 or FIG. 3. Let W denote the width of the flame port 21 of the burner 2. The W system is selected in consideration of the width of the metal wall plate 1 and is usually 40 cm to 50 cm. In addition, the shape of the flame port is not particularly limited, and generally a burner with a shape or a round hole shape can be used.

Burners with a burner head of this structure are commercially available. For example, Flynn Burner (USA) product name F-3000, Finecom I&T (Korea) product name FFP250, etc. exist.

In addition, the foregoing description of "the width of the flame port of the burner per 10 mm" means that W'in FIG. 4 is 10 mm.

The conveying speed of the metal wall plate 1 by the conveying machine 4 is not particularly limited as long as the effect of the present invention is exerted, and it is usually 5 m/min to 70 m/min relative to the fixed burner 2. It is preferably 10 m/min to 40 m/min, and more preferably 15 m/min to 30 m/min. If the conveying speed is less than 5 m/min, even if the output of the burner is reduced, the surface temperature of the metal-based substrate 1 may exceed 300°C. In addition, if it exceeds 70 m/min, the flame of the burner 2 will be affected by the air flow generated by the movement of the metal wall plate 1, and the printed surface 1-1 of the metal wall plate 1 cannot be uniformly irradiated with flame, and the dirt cannot be removed. (Foreign matter) Fully removed.

The fuel gas of the burner 2 is not particularly limited. Generally, hydrogen gas, liquefied petroleum gas (LPG; Liquefied Petroleum Gas), liquefied natural gas (LNG; Liquered Natural Gas), acetylene gas, propane gas, or butane, etc. are used. As the combustion-supporting gas of the fuel gas, air or oxygen can be used. Considering the combustion energy, it is preferable to use LPG or LNG.

For the flame-treated metal wall plate 1, inkjet printing is performed using an inkjet coating machine 5. Four colors are used for printing, yellow ink is ejected from the inkjet recording head 61, cyan ink is ejected from the inkjet recording head 62, magenta ink is ejected from the inkjet recording head 63, and black (black) is ejected from the inkjet recording head 64 ) Ink. Ink supply tanks (71 to 74) are connected to the inkjet recording heads, respectively. As the printing ink, commercially available active light-curing printing ink can be used.

The ink droplets ejected from the inkjet recording heads of various colors fly in the vertical direction toward the printing surface 1-1. The initial speed of the ink droplets is usually set to 3 m/sec to 9 m/sec, preferably 4 m/sec to 7 m/sec. The initial speed of the ink droplets refers to the speed of the ink droplets when ejected from the recording head. For example, the distance between the ink droplets ejected from the inkjet recording head and the ink ejection portion in the vertical direction is 1 mm and the distance required to travel the distance of 1 mm is calculated (predetermined distance/time).

If the initial speed of the ink droplets does not reach 3m/sec, the speed of the droplets is too slow, so the spraying accuracy of the ink droplets may be greatly reduced. In addition, in the case of more than 9m/sec, the spraying accuracy is good, but sometimes there is a problem that the satellite dots of the ink are generated and the image quality is lowered.

The volume of ink droplets ejected from the nozzle of the inkjet recording head to one of the printing surfaces 1-1 is not particularly limited, and is generally set to less than 60 pl (picoliter; 10 ^-12 liters), preferably 10 pl or more and less than 45 pl .

The active light irradiator 9 is provided at a predetermined position on the downstream side of the inkjet coating machine 5 in the conveying direction. Here, "active rays" in the present invention may include electron beams, ultraviolet rays, alpha rays, gamma rays, X-rays, and the like. In the present invention, considering safety or operability, it is preferable to use electron beams and ultraviolet rays, and most preferably to use ultraviolet rays.

The active light irradiator 9 is provided with a lamp for irradiating the active light toward the conveying surface 4-1 of the conveyor 4 and irradiates the active light toward the conveying surface 4-1.

The active ink from the active light irradiator 9 is used to harden the ink droplets sprayed onto the printing surface 1-1. Generally, the conveying speed of the conveyor 4 and the inkjet coating machine are adjusted in such a manner that the active light is irradiated after 1.0 second or more, preferably 2.0 seconds or more, and more preferably 2.2 seconds or more after the ink droplets are sprayed and attached. The distance to the active light irradiation machine 9. In addition, sometimes the moisture in the air hinders the polymerization of the ink, so the active light is irradiated within 30 seconds after the ink is sprayed.

The control section 8 controls various processes including the following: pattern giving based on the recording of the image formed in the inkjet recording device M or temperature adjustment of the inkjet recording head. The control unit 8 includes a circuit board mounted with electronic components, electrical wiring, and the like. As shown in FIG. 3, at least a part of the configuration included in the control unit 8 is provided above the inkjet recording head.

The line-type inkjet recording device M includes a predetermined interface (not shown) such as a network interface. The inkjet recording device M is communicably connected to an external device such as a personal computer via an interface. The external device inputs the recording instruction of the image on the printing surface 1-1 and the data representing the recorded image to the inkjet recording device M. In the inkjet recording apparatus M to which the recording command is input, predetermined processing is performed. The above ink is ejected from the inkjet recording head onto the printing surface 1-1 to form a desired image, and the manufacturing method of the decorative building board of the present invention is carried out.

[Example]

Examples and test examples are given below to explain the present invention more specifically, but the present invention is not limited thereto.

1. Manufacture of metal wall panels

(1-1) Manufacture of metal base materials

A molten zinc-55% aluminum alloy plated steel sheet having a plate thickness of 0.27 mm and an A4 size of 90 g/m ² per one-side plating adhesion is used as the base material. The plated steel plate was subjected to alkaline degreasing. Then, the coating type chromate (NRC300NS: Nippon Paint Co., Ltd. made by chromium (Cr) as the adhesion amount of 50 mg/m ² ) and the commercially available epoxy resin system as the undercoat layer The primer coating (700P manufactured by Nippon Fine Coatings Co., Ltd.) was coated with a roll coater so that the dry film thickness became 5 μm. Then, the baking is performed so that the maximum plate temperature becomes 215°C.

(1-2) Manufacture of ink receiving layer

The composition of the paint as the resin composition for forming the ink-receiving layer is as follows. For the resin, a polymer polyester resin (manufactured by DIC Corporation) having a number average molecular weight of 5,000, a glass transition temperature of 30°C, and a hydroxyl value of 28 mgKOH/g is used. As the melamine resin as a crosslinking agent, a methylated melamine resin (CYMEL 303 manufactured by Mitsui Cytec) of 90 mol% methoxyl was used. The blending ratio of polyester resin and melamine resin is 70/30, and titanium oxide (JR-603 manufactured by Tayca) with an average particle size of 0.28 μm is added as 49% by mass of mica (Yamaguchi Mica Co., Ltd.) Manufactured SJ-010) 13% by mass, hydrophobic silica with an average particle size of 5.5 μm (Sylysia 456; Fuji Silysia Co., Ltd.) 6% by mass, hydrophobic silica with an average particle size of 12 μm (Fuji Silysia Chemical Co., Ltd. Sylysia 476) manufactured by the limited company 2% by mass. The catalyst system added 1 mass% of dodecylbenzenesulfonic acid with respect to the resin solid content. In addition, dimethylaminoethanol as an amine is added in an amount of 1.25 times the amine equivalent to the acid equivalent of dodecylbenzenesulfonic acid. After coating with a roll coater so that the dried film thickness of the coating becomes 18 μm, baking is performed so that the maximum limit plate temperature becomes 225°C.

In addition, the average particle diameters of the above-mentioned mica, hydrophobic silica, and titanium oxide are determined by the Coulter counter method.

Specifically, it is measured in the following manner. As a measuring device, a Coulter counter (manufactured by Coulter Corporation, USA) TA-II type was used. Weigh about 0.5g of the sample and place it in a 200ml beaker, add about 150ml of pure water, and use ultrasound (ULTRASONIC CLEANER B-220) to disperse the sample for 60 to 90 seconds. Several drops of the above-mentioned dispersion liquid were added to 150 ml of the attached electrolyte solution (ISOTON II: 0.7% high-purity sodium chloride (NaCl) aqueous solution) using a dropping device, and the particle size distribution was determined using the above-mentioned apparatus.

Among them, the JR-603 (titanium oxide) and Sylysia 456 (hydrophobic silica) use a 30 μm aperture tube. In addition, SJ-010 (mica) uses a 50 μm mouth tube. The average particle size is obtained by reading the 50% diameter of the cumulative particle size distribution diagram.

(1-3) Concavo-convex formation of metal-based substrates

The metal-based substrate having the ink receiving layer described above is subjected to surface processing using embossing.

The metal-based substrate with the ink-receiving layer wound around the decoiler is continuously sent out, and the metal-based substrate is continuously formed into a pressure of 0.5mm to 1.5mm with a brick pattern by a roller embossing machine The grain shape forms a metal-based substrate with the appearance of a granite simulated pattern.

(1-4) Formation of core material and back material

On the back of the formed metal-based substrate, Soflan R-HIP and Toyo Soflan R746-19D (both made by Soflan Wiz Co., Ltd.) as the raw materials of polyisocyanurate as the core material are foamed The machine mixes at a mass ratio of 10 to 7 and sprays out through the mixing extruder. In addition, aluminum kraft paper (back material) is sent out onto the foamed polyisocyanurate raw material layer. Then, the polyisocyanurate raw material layer is sandwiched between the embossed metal base material and the aluminum kraft paper, and then heated, pressurized, and foamed to form, which in turn includes printing ink acceptance The metal layer of the layer is the base material, core material and metal wall board of aluminum kraft paper. In addition, the thickness of the core material is set to 17 mm. The thickness of the core material is adjusted by the distance between the double conveyor belts sandwiching the original metal wall panel in the stacking direction of the original metal wall panel during the heating and pressing.

The detailed foaming conditions of the polyisocyanurate raw material are as follows.

Linear speed 40m/min.

Flow rate 6kg/min.

The liquid temperature is 30℃.

The preheating temperature of the metal substrate with the ink-receiving layer is 35℃.

The oven treatment temperature is 50℃.

Foaming machine Low-pressure type mixing and foaming machine.

2. Burner for flame treatment

As a burner for flame treatment, FFP200 (made by Finecom I&T (Korea) Co., Ltd.) was used. Using LP (Liquefied Petroleum; Liquefied Petroleum) gas as combustion gas, the width of the flame port of the burner is LP gas of 0.04L/min to 2.00L/min per 10mm, and clean dry air of 1L/min to 50L/min is used After the gas mixer is mixed, the mixed gas is burned by a burner to perform flame treatment. In addition, the length of the flame port of the burner used in the direction parallel to the conveying direction (L in FIG. 1) is 5 mm, 20 mm, 30 mm, and 40 mm.

Furthermore, the conveying speed at the time of flame treatment is 5 m/min to 70 m/min.

3. Inkjet printing using active light hardening ink

(3-1)

As the active light-curing ink, radical polymerization type ultraviolet curable black ink and cation polymerization type ultraviolet curable black ink are used. The specific composition of each printing ink is as follows.

(i) Radical polymerized UV curable black ink

The radical polymerization type ultraviolet curable black ink is prepared by mixing the following components. The specific composition is as follows.

1) Pigment: NIPex 35, carbon Degussa Japan (Co., Ltd.), dispersion medium: SR9003, PO (Propoxylated; Propoxylated) modified neopentyl glycol diacrylate Sartomer Japan (Co., Ltd.).

2) CN985B88, a mixture of 88% by mass of difunctional aliphatic acrylate carbamate and 1,6-hexanediol diacrylate by 12% by mass manufactured by Sartomer Japan (Co., Ltd.).

3) 1,6-hexanediol diacrylate.

4) Irgacure 184, manufactured by hydroxyketones Ciba Japan (Co., Ltd.).

5) Irgacure 819, manufactured by Ciba Japan (Co., Ltd.), based on acetylphosphine oxide.

(ii) Cationic polymerized UV curable ink

20 parts by mass of pigment black: Pigment Black 7 was added to 9 parts by mass of the polymer dispersant (PB821 manufactured by Ajinomoto Fine-Techno Corporation) and 71 parts by mass of the oxetane compound (OXT211 manufactured by Toa Synthesis). Put it in a glass bottle together with 200g of zirconia beads with a diameter of 1mm and fasten it. After 4 hours of dispersion treatment with a paint shaker, remove the zirconia beads to adjust the black pigment dispersion.

The following photopolymerizable compound, basic compound, surfactant, compatibilizer, and photoacid generator were mixed with 14 parts by mass of the above dispersion to prepare a cationic polymerization type ultraviolet curable inkjet ink.

The volume of the ink droplets was set to 42 pl, and dot printing was performed with black ink using an inkjet printer (manufactured by Tritek Corporation, Patterning JET). The printing conditions at this time are as follows. Dot printing using black ink was performed on the entire metal wall plate by setting the distance between the dots to 500 μm so that the dots did not coincide with each other. The spot diameter was measured using a scanning confocal laser microscope LEXT OLS3000 manufactured by Olympus Corporation. Zoom in to the range where only one point can be seen (200 times), and measure the diameter of 8 points, indicating the average value of the diameter of these 8 points. When the point spread is close to an ellipse, the average of the long and short diameters is set to the point diameter. The spot diameter of the metal wall panel before flame treatment changes according to the degree of dirt adhesion. The spot diameter of the part where the dirt is attached is about 130μm. Compared with this, the spot where there is almost no dirt is about 180μm, and there is about 50μm difference.

Inkjet printing conditions of free radical polymerization type ultraviolet curing ink.

(a) Nozzle diameter: 35 μm.

(b) Applied voltage: 11.5V.

(c) Pulse width: 10.0 μs.

(d) Drive frequency: 3,483 Hz.

(e) Resolution: 360dpi.

(f) Volume of ink droplets: 42pl.

(g) Head heating temperature: 45°C.

(h) Ink coating amount: 8.4g/m ² .

(i) Distance between head and recording surface: 5.0 mm.

(j) Initial speed of ink droplets: 5.9m/sec.

Inkjet printing conditions of cationic polymerization type ultraviolet curing ink.

(a) Nozzle diameter: 35 μm.

(b) Applied voltage: 13.2V.

(c) Pulse width: 10.0 μs.

(d) Drive frequency: 3,483 Hz.

(e) Resolution: 360dpi.

(f) Volume of ink droplets: 42pl.

(g) Head heating temperature: 45°C.

(h) Ink coating amount: 8.4g/m ² .

(i) Distance between head and recording surface: 5.0 mm.

(j) Initial speed of ink droplets: 6.1m/sec.

In this embodiment, ultraviolet light is used as active light. The UV curing of the ink is performed under the following conditions after inkjet printing. Ultraviolet irradiation is performed after the ink droplets are sprayed for 5 seconds.

(1) Type of lamp: High-pressure mercury lamp (H valve manufactured by Fusion UV System Japan Co., Ltd.).

(2) The output of the lamp: 200W/cm.

(3) Cumulative light quantity: 600mJ/cm ² (measured using an ultraviolet light meter UV-351-25 manufactured by ORC).

No matter how much the dirt on the surface of the metal wall plate adheres to the flame treatment under specific conditions, it can be seen that the homogeneous and sufficient wetting and diffusion of the printing ink. In this example, the flame-treated UV-curable printing ink with a dot diameter of 190 μm to 210 μm was evaluated as ○. In addition, with regard to the cationic polymerization type ultraviolet curable ink, the ink dot diameter of 200 µm to 220 µm was evaluated as ○.

4. Measurement of the temperature of the metal base material

Install thermocouple thermometer (type K) (temperature recorder LR5021 from Hitachi Electric Co., Ltd.) and sensor (band type multifunctional temperature sensor from Anritsu Co., Ltd.) on the metal base material of the metal wall plate The surface is measured.

5. Adhesive strength measurement method of metal base material and core material (synthetic resin foam)

As shown in FIG. 5, a method of measuring the strength of the metal-based substrate and the core material was performed. First, a hot-melt adhesive 101 (trade name: hot-melt bar multi-purpose white HSW-01K, manufactured by Henkel Japan Co., Ltd.) is attached to the front and back of the metal wall plate of 50 mm×50 mm from which the back surface is removed, and a wood chip 102 (9 mm ×65mm×70mm). Next, using the stretching jig 103, the direction of the up and down arrows was stretched at a stretching rate of 5 mm/min, and the maximum peel strength (kg/cm ² ) was measured. The maximum peel strength of the three parts of the wall-side male-side fitting portion, the central portion, and the female-side fitting portion was averaged to be the adhesive strength of the metal-based substrate and the synthetic resin foam. If the adhesive strength is 0.3 g/cm ² or more, it is regarded as a pass.

The above-mentioned wall board is flame-treated using the above-mentioned burner, and printing is performed under the above printing conditions. The dot diameter of the black ink of this sample and the adhesion strength of the metal base material and the core material were measured. The test results are shown below.

Furthermore, the burner output represents an output of 10 mm with respect to the width of the flame port. Therefore, even if the length of the flame port in the direction of travel is different, the energy of the flame radiated from the burner is the same. For example, in Examples 7 and 8, the burner output is the same, and the length of the flame port in the direction of travel is different, but the metal-based substrate of the metal wall plate receives the same energy from the flame emitted from the burner.

1‧‧‧Metal wall plate

2‧‧‧Burner

3‧‧‧ Flame

11‧‧‧Metal base material

12‧‧‧Core material

13‧‧‧Back agent

14‧‧‧Ink receiving layer

21‧‧‧flame mouth

22‧‧‧Burner head

d‧‧‧(The unevenness of the metal base material) height difference

H‧‧‧ (the shortest distance between the burner and the printing surface)

L‧‧‧(the direction parallel to the conveying direction in the flame port of the burner) length

Claims (6)

A method for manufacturing a decorative building board, comprising: a metal wall plate, including a metal-based substrate forming a concave-convex pattern with a height difference of 0.5 mm or more, a core material and a back material, and a resin composition is arranged on the substrate The formed ink-receiving layer is irradiated with flame to the metal wall plate with an output of 250 kJ/hour to 12000 kJ/hour for every 10 mm of the width of the flame port of the burner, and the surface temperature of the substrate does not exceed 300° C. After treatment, inkjet printing is performed using active light-curing ink. The method for manufacturing a decorative building board according to claim 1, wherein the ink receiving layer is impermeable to the active light-curable ink. The method for manufacturing a decorative building board according to claim 1 or 2, wherein the active light-curable ink is an active light-curable cationic polymer ink. The method for manufacturing a decorative building board according to claim 1 or 2, wherein the height difference of the uneven pattern is 7.0 mm or less. The method for manufacturing a decorative building panel according to claim 1 or 2, wherein the conveying speed of the metal wall board is 5.0 m/min to 70 m/min. The method for manufacturing a decorative building board according to claim 1 or 2, wherein the core material is polyisocyanurate foam.

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