Plaster sheet

Abstract

To provide a plaster sheet which exhibits strong alkalinity unique to a plaster moderately, exhibits plaster effect continuously while having small film thickness, has a plaster surface design and coating performances similar to site works provided with a plaster-like irregularity design finishing by synchronization printing for representation of surface design by site work finishing of a plaster, moreover, has improved stain resistance, water resistance, friction resistance, etc., which are weakness unique to a plaster, and excellent coating film properties.SOLUTION: The plaster sheet is provided by: forming a plaster coating film 1 as a first layer coating film on a sheet substrate 4; printing a heat-expandable hydrophilic color ink on the plaster coating film 1; further applying an acrylic resin thereon, followed by heating, blowing, and polishing steps, thereby forming a porous groove coating film 2 as a second layer coating film provided with porous grooves synchronizing with a printed pattern of the heat-expandable hydrophilic color ink; and applying an inorganic antimicrobial coating 3 as a third layer coating film in convexes other than porous grooves of the second layer acrylic resin coating film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a plaster sheet made of plaster used as interior materials for residential equipment, fixtures, furniture, decorative materials, etc., and in particular to a plaster sheet that can compensate for quality issues when used as an interior material. [Background technology]

[0002] Plaster, which is primarily composed of calcium hydroxide, has traditionally been used for the interior and exterior walls of buildings. For example, plasterers apply plaster walls to the interior of buildings. It has also been used for exterior walls and fences since ancient times. However, in recent years, it has been streamlined to be easier to apply and handle, and is now used as wallpaper and decorative items.

[0003] This plaster exhibits the strong alkaline properties unique to plaster, and is used in some places and is also being researched and developed as it has antibacterial and antiviral properties. However, calcium hydroxide, which exhibits strong alkaline properties, reacts with carbon dioxide in the air to form calcium carbonate, which causes a gradual decrease in the strong alkaline, antibacterial, and antiviral properties unique to plaster, especially in the surface layer. Furthermore, plaster coatings are highly alkaline, which is a dangerous condition, and the coating surface has poor resistance to contamination, water, and scratches, making them difficult to use as interior materials for residential equipment, fixtures, furniture, decorations, etc.

[0004] In recent years, sheets of plaster have been commercially available that claim to have high antibacterial and antiviral properties, but these plaster sheets lack the authentic finish of a thick film like that of a plasterer troweling on-site, and many of them are made to look similar using printing techniques, embossing, etc. In other words, there is a need for the development of a plaster sheet that can fully demonstrate excellent properties such as antibacterial and antifungal properties while reproducing the surface appearance unique to plaster.

[0005] As a method for solving the above-mentioned problems, a method has been devised in which the uneven surface of the plaster coating film is utilized to apply a functional top coat by inkjet printing thereon (see, for example, Patent Document 1).

[0006] Patent Document 1 relates to multilayer sheets and inkjet printing, and in the technical field section it states, "The present invention relates to a multilayer sheet, and more specifically to a method for producing an imaged multilayer sheet, which is characterized by applying a coloring material to the plaster layer side of a laminated sheet having a base sheet and a plaster layer containing semi-solidified plaster laminated on the top surface of the base sheet to perform an image, and then forming a resin layer on the plaster layer."

[0007] As another method for solving the above-mentioned problems, a method of applying a water-based top coat onto a plaster coating film has been devised (see, for example, Patent Document 2).

[0008] The object of the invention of the above-mentioned Patent Document 2 is to provide an antifouling treatment material for plaster-coated surfaces that can impart excellent stain-preventing and removability to plaster-coated surfaces while maintaining the functionality of the plaster and without impairing its texture, a finishing method for plaster-coated surfaces using the same, and a method for manufacturing plaster-coated products that have stain-preventing and removability. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-016395 [Patent Document 2] Patent No. 5974323 Summary of the Invention [Problem to be solved by the invention]

[0010] Plaster sheets and the like have begun to be used as decorative items for living spaces and everyday life thanks to the methods described in Patent Documents 1 and 2. However, when plaster is used as the outermost coating sheet, the strong alkalinity specific to plaster on the surface becomes stronger, but because the plaster coating is thin, it is difficult to sustainably demonstrate the specific properties of plaster.

[0011] Also, it was difficult to achieve the texture of a trowel applied by a plasterer on-site, and no satisfactory results were obtained.Furthermore, although it was common to create textures such as printing or embossing to resemble plaster, these were not satisfactory when compared to real plaster in appearance and quality.

[0012] Therefore, the object of this invention is to provide a new plaster sheet that gently exerts the strong alkalinity unique to plaster, and that exerts the effects of plaster continuously despite a low film thickness, and that has the same plaster design and coating performance as on-site application with a plaster-like uneven pattern finish using synchronized printing to express the surface design of on-site plaster application finish, and that further improves the stain resistance, water resistance, and scratch resistance that are unique to plaster. [Means for solving the problem]

[0013] As a result of extensive research, the inventors have invented a plaster sheet with a two-layer or three-layer structure in which a plaster coating film and a porous groove coating film are formed on the surface of a sheet substrate, and an antibacterial coating film is also formed as needed, thereby overcoming the problems inherent in plaster and realizing an external texture on the sheet substrate.

[0014] That is, the invention described in claim 1 is a plaster sheet having a first layer and a second layer in this order on a sheet substrate, the first layer being made of a plaster coating film mainly composed of calcium hydroxide, and the second layer being made of , on the first layer Printing with heat-foaming capsule ink did Part and heat-foaming capsule ink It consists of the paint part other thanThis is a plaster sheet characterized in that the heat-foamable capsule ink is heated and foamed, and then ground to form porous grooves with perforations that partially expose the first layer of plaster coating film in the area where the heat-foamable capsule ink is printed.

[0015] The invention of claim 2 is the plaster sheet according to claim 1, wherein the second layer in porous groove pit The area of ​​the part is 10 to 80% of the entire sheet.

[0016] The invention of claim 3 employs a constitution in which the plaster sheet of claim 1 or 2 contains an antibacterial material in the second layer.

[0017] The invention of claim 4 is the plaster sheet according to any one of claims 1 to 3, wherein the second layer is a heat-foaming capsule type ink. Other paints A configuration was employed having a third layer consisting of an antimicrobial coating applied over the portion.

[0018] The invention of claim 5 is the plaster sheet according to claim 4, wherein the coating amount of the third layer is 0.1 to 15 g / m 2 The area is 90 to 20% of the entire sheet substrate. The third layer of paint is, The coating is made of an acrylic paint containing an inorganic antibacterial agent.

[0019] The invention of claim 6 is the plaster sheet according to any one of claims 1 to 5, wherein the second layer and / or the third layer contains diatomaceous earth.

[0020] The invention of claim 7 is a building material in which the plaster sheet according to any one of claims 1 to 6 is attached to a substrate. [Effects of the Invention]

[0021] As described above, according to the plaster sheet of the invention of claim 1, the alkalinity generated from the plaster coating film of the first layer penetrates into the grooves of the porous coating film of the second layer. pitBy expressing this externally through the coating, it is possible to exert mild, long-term antibacterial and antiviral properties due to its alkaline nature, similar to those of ordinary plaster walls.

[0022] According to the plaster sheet of the invention of claim 2, by using heat-foaming capsule-type ink to form the second layer, a porous groove coating film can be easily formed by processing such as heating, foaming, hardening, and grinding, and by forming the second layer coating film in sync with the printed pattern of the heat-foaming capsule-type ink, the three-dimensional effect and trowel finish unique to plaster walls can be reproduced.

[0023] According to the plaster sheet of the invention of claim 3, the plaster effect of the first layer can be maintained for a long period of time, and a synergistic effect with the antibacterial effect of the antibacterial material contained in the second layer can be obtained.

[0024] According to the plaster sheet of the invention of claim 4, the antibacterial material in the third outermost layer can provide properties such as mold resistance, contamination resistance, water repellency, and scratch resistance that cannot be obtained with ordinary plaster walls.

[0025] According to the plaster sheet of the invention of claim 5, it is possible to maintain an optimal balance between the effects and durability of the antibacterial and antiviral properties due to the alkalinity of the first layer of plaster coating film, and the antibacterial properties, antifungal properties, stain resistance, water repellency, scratch resistance, etc. of the third layer of antibacterial coating film.

[0026] According to the plaster sheet of the invention of claim 6, the diatomaceous earth contained in the second and third layers exhibits moisture-regulating and odor-absorbing properties, further enhancing the effectiveness of the plaster sheet.

[0027] The building material of the invention of claim 7 can be used as a building material that can exhibit the effects described in claims 1 to 6, as well as various other materials for daily necessities, furniture, etc. In addition, by using a material with excellent humidity control properties that has moisture absorption and release properties as the base material to which it is attached, it can also have the same humidity control effect as a conventional thick plaster wall. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is an overall view showing a three-layer plaster sheet of the present invention. [Figure 2] A diagram showing the structure of the three-layer plaster sheet of this invention, which exhibits alkaline and antibacterial properties. [Figure 3] This is a diagram showing the structure of the two-layer plaster sheet of this invention, which exhibits alkaline, moisture-regulating, and antibacterial properties. DETAILED DESCRIPTION OF THE INVENTION

[0029] The plaster sheet of the present invention will be described in detail below with reference to the accompanying drawings. The plaster sheet in Figure 1 is, for example, a plaster coating film 1 that forms the first layer on a sheet substrate 4, on which an arbitrary print is made using a heat-foaming hydrophilic ink, and then an acrylic resin is applied, after which a second layer with a porous uneven pattern that matches the printed pattern is formed, and the third layer that forms the surface is a plaster sheet with a three-layer structure consisting of alkaline plaster and antibacterial coating film 3 that has antibacterial properties.The second layer is a porous grooved coating film 2 that brings out the alkalinity of the plaster in the first layer, and the physical properties of the outermost surface are paper-like, exhibiting antibacterial, antiviral, and other properties inherent to the plaster.It is a plaster sheet on various substrates.

[0030] The plaster sheet in Figure 2 shows how the top surface exhibits alkalinity derived from the plaster while simultaneously exhibiting antibacterial properties A in the third layer. When moisture penetrates from the top or elsewhere and comes into contact with the first layer of plaster coating film 1, it becomes alkaline due to calcium hydroxide, the main component of plaster. Furthermore, the calcium hydroxide is guided to the upper layer by the grooves of the second layer of porous antibacterial coating film 2 or by capillary action in the porous layer, thereby exhibiting alkalinity B.

[0031] The method for manufacturing a plaster sheet involves applying plaster to a sheet substrate 4 and drying it to form a plaster coating film 1, then applying a printed pattern on top of that using heat-foaming hydrophilic ink, applying acrylic resin, and heating, foaming, and grinding to form a porous groove coating film 2, and then applying a resin coating of a top coat of antibacterial coating film 3, in this order, to create a plaster sheet on the sheet substrate 4 with projections and depressions that match the printed pattern.

[0032] The plaster sheet in Figure 3 is an example in which a first layer of plaster coating film 1 is applied to a sheet substrate 4, and a second layer of porous groove coating film 2 is applied on top of that, and unlike the examples shown in Figures 1 and 2, it has a two-layer structure without a third layer. The manufacturing method for the first and second layers is the same as that shown in Figures 1 and 2, in which the first layer of plaster coating film 1 is applied to the sheet substrate 4, and then an optional printing is done on top of that using a heat-foaming hydrophilic ink, and then an acrylic resin is applied, and then a second layer with a porous uneven pattern that matches the printed pattern is applied.

[0033] In the example shown in Figure 3, diatomaceous earth and antibacterial material are contained in the acrylic resin that is applied after printing any pattern using heat-foaming hydrophilic ink, so that the diatomaceous earth and antibacterial material are contained in the convex parts without grooves in the second layer of porous grooved coating film 2.This plaster sheet not only exhibits alkalinity B due to the plaster, but also moisture-regulating and deodorizing properties C due to the diatomaceous earth, and antibacterial properties D due to the antibacterial material.

[0034] [Sheet substrate] The sheet substrate 4 used in this invention is the main part of the plaster sheet, and can be made of various sheet-like materials as long as it is flexible and can be in the form of a sheet, for example, paper, paper materials, films, resin materials, etc. Examples include composites of mainly paper with resin, laminates of paper and film, laminates of paper or film and wet-laid nonwoven fabric, composites of paper and film laminates with resin, and materials consisting only of nonwoven fabric or film.

[0035] Among the materials for the sheet substrate 4, the paper raw material of paper or paper material is 15 to 200 g / m 2 It includes paper materials that are compounded with resins, pigments, fillers, etc. It also includes laminated materials of paper materials and resinous materials, such as those in which PE, PP, or other resinous materials are melt-bonded or laminated to the aforementioned paper materials, and further includes those in which synthetic resins, melt-bonded resins, or film materials are compounded with the resinous layer.

[0036] Furthermore, the raw materials for the resin and film are not particularly limited, and can be any materials that blend with the paper material and can be formed into sheets. Examples of resins include acrylic resin, acrylic emulsion, acrylic water-soluble resin, etc., and other known resins such as PE and PP.

[0037] As described above, the sheet substrate 4 can be made of the same material and form as a plaster sheet; in other words, as long as the entire plaster sheet is defined by the invention, its material and form are not important.

[0038] When plaster sheets are attached to other substrates, such as non-combustible substrates, plywood, gypsum board, fiberboard, etc., to enhance the performance of the other substrates, particularly when humidity control is desired, the humidity control effect of the plaster sheet alone is low, so it is necessary to add value to the product by including the other substrates. In this case, if a substrate sheet with good breathability (low air permeability seconds) of the sheet substrate of the present invention, with an air permeability (JIS P 8117) of about 1500 seconds or less, is used, the back side will also be alkaline, and the first layer of plaster coating will affect the substrate to which it is bonded, such as the fiberboard substrate, through the sheet substrate, and a humidity control effect can be expected as a composite with the plaster sheet.

[0039] This is because the backside of the plaster sheet of the present invention (air permeability of the sheet base material ≒ 1000 seconds) exhibits alkalinity. The air permeability of ordinary building paper is about 20 to 100 seconds, 300 to 800 seconds for reinforced paper, and even more than 1000 seconds depending on the type of paper, thickness, etc. The air permeability can be selected according to the purpose.

[0040] [First layer: plaster coating] Plaster is generally composed mainly of calcium hydroxide, which, when formed into a coating, has the property of reacting with carbon dioxide in the air to produce calcium carbonate and solidify at the same time. Therefore, by providing areas that do not come into contact with carbon dioxide in the air, the calcium hydroxide is not lost in the areas that do not come into direct contact with the air, and the inherent properties of plaster are continuously demonstrated. For example, if plaster coating film 1 is applied to sheet substrate 4 at a rate of 55 g / m 2By forming a plaster coating film 1 and exposing 40% of the surface area to the air, the alkalinity indicated by calcium hydroxide measured on the coating surface was able to be maintained for a longer period of time when the plaster coating film was exposed to 40% of the surface compared to when the entire surface was exposed.

[0041] In order to obtain a predetermined alkalinity, the ratio of the area of ​​the first layer of plaster coating film 1 exposed to the air is adjusted by adjusting the grooves in the porous groove coating film in the second layer described later. pit It is determined by the ratio of

[0042] [Second layer: porous trench coating] To form the porous groove coating film 2 on the first layer of plaster coating film 1, first, a plaster look or any desired pattern is printed on the formed plaster coating film 1 using a heat-foaming capsule-type ink, for example, a hydrophilic heat-decomposing capsule-type foaming ink.

[0043] The printing method for the print pattern on the plaster coating surface (1) can be any type of printing equipment as long as it is capable of printing on the sheet substrate (4). However, when producing industrial products, gravure printing is preferred. The printing ink used for gravure printing is composed of acrylic resin, pigment, heat-foaming capsules, surfactant, diluent, etc., and may be oil-based or water-based. Hydrophilic ink is preferable. Various other known inks and materials can also be used. The number of printing plates can be one to six depending on the design requirements, but about four plates is preferable. In particular, printing technology can reproduce the three-dimensional effect, trowel finish, and image derived from plaster, which are unique to plaster.

[0044] When a thermosetting acrylic resin paint is applied to this printed, flat surface and heated, the capsules in the foaming ink foam, and the thermosetting acrylic resin synchronizes with the printed pattern, forming a porous layer. Grinding away the porous layer exposes part of the first layer of plaster. Even if it is not exposed, a coating film is formed in which the porous film and the plaster are mixed. Furthermore, the fine porous layer is formed, which guides the alkalinity from the plaster layer through capillary action. In other words, the presence of the first layer of plaster is indicated on the top surface of the upper layer.

[0045] As described above, a plaster-like or any pattern is printed on the first layer plaster coating film 1 using a heat-foaming capsule type ink, and then a thermosetting acrylic resin paint is applied and heated, causing the capsules in the foaming ink to foam and the thermosetting acrylic resin to synchronize with the printed pattern, forming a porous layer film.The surface is then ground to create porous grooves. pit Therefore, the part of the print pattern printed first with the heat-foaming capsule ink becomes the grooved part (exposed part), and the remaining part where the thermosetting acrylic resin paint has hardened remains as a convex part, and this convex part suppresses the development of alkalinity by the plaster coating film 1 of the lower first layer. In other words, the porous grooves are formed by the printing area with the heat-foaming capsule ink. pit Groove of coating 2 pit The ratio can be adjusted.

[0046] Incidentally, there is a method for forming the porous grooved coating film 2 as described above, such as the "Decorative Sheet" method disclosed in Japanese Patent Laid-Open Publication No. 7-125143, which involves heating and foaming at a high temperature of nearly 200°C. However, in the present invention, the foaming agent is in the form of a capsule made of a thermoplastic resin, dispersed in a hydrophilic ink, and a foaming region is set up in which foaming is possible even at a heating temperature of 150°C or less. The resin constituting the second porous layer is an oil-based modified acrylic resin that can be foamed at low temperatures. For example, an acrylic resin manufactured by DIC Corporation, "UC Clear NTGM / hardener W / butyl acetate / ethyl acetate = 100 / 10 / 15 / 5," is mixed and printed on a gravure printing machine at a rate of 2 to 30 g / m. 2 After application, the material is dried with hot air at 140°C for 30 seconds, and then foamed, ground, and polished to form a porous, uneven pattern.

[0047] The porous groove coating film 2 in this invention is formed from grooves and convex parts without grooves, and it is effective for the area of ​​the grooves, i.e., the area of ​​the first layer plaster coating film 1 exposed to air, to be 10 to 80% of the entire sheet, and even more preferably within the range of 20 to 50%.

[0048] Furthermore, the convex portions can be formed not only as vertically steep portions from the grooves, but also as gently sloping portions, and the presence or absence of this slope, its angle, and its proportion can be adjusted as appropriate, and these adjustments will change the feel of the sheet surface when viewed or touched.

[0049] The combination of this first layer of plaster coating film 1 and the second layer of porous groove coating film 2 allows for the reproduction of the three-dimensional effect and trowel finish that are unique to plaster walls, and with this second layer as the top layer, the basic plaster sheet is completed. The advantage of completing the plaster sheet with a two-layer structure of first layer of plaster coating film 1 and second layer of porous groove coating film 2 is that the porous layer of first layer of plaster coating film 1 and the porous effect of the second layer of porous groove coating film 2, which is the top layer, can be expected. Furthermore, by freely adjusting the area of ​​the porous grooves (the exposed plaster area), it is possible to adjust the alkaline level from strong to weak, similar to commercially available products.

[0050] By blending antibacterial agents, diatomaceous earth, inorganic and organic slip agents, matting agents, and various additives into the thermosetting paint material that forms this second layer, these components are contained in the convex parts of the second layer porous grooved coating film 2, which is the outermost surface of the two-layer structure, making it possible to obtain surface properties that include these properties.

[0051] First, by incorporating an antibacterial agent, the alkalinity of the first layer of plaster coating (1) is suppressed in the second layer of porous coating (2) (to maintain long-term performance), but the antibacterial properties inherent in the alkalinity of the plaster coating are reduced. Therefore, the antibacterial component of the antibacterial agent contained in the convex portions of the second layer of porous coating (2) that suppress alkalinity compensates for the reduced alkalinity. Antibacterial paints themselves primarily use inorganic antibacterial agents, which are known for their long-term antibacterial and antiviral properties. Of course, by selecting the type and composition of the antibacterial material, properties such as mold resistance, stain resistance, water repellency, and scratch resistance that cannot be achieved with ordinary plaster walls can also be achieved.

[0052] Diatomaceous earth can also be added to improve the coating's moisture-regulating and deodorizing properties. General-purpose diatomaceous earth particles of 1μ to 50μ can be dispersed in the coating material, and the coating material can be applied in a Clavier coating machine at a concentration of 10 to 80g / m. 2 It is sufficient to form a coating film to that extent. That is, by adding diatomaceous earth to the second and third coating layers, the moisture-regulating and deodorizing effects of the plaster sheet of the present invention can be expected. For example, a diatomaceous earth coating can be obtained by mixing 5 to 70% of "diatomaceous earth" manufactured by Showa Chemical Industry Co., Ltd. with "UC Clear NTGM / Hardener W" acrylic resin manufactured by DIC Corporation and dispersing the mixture in a coating manufacturing machine. A preferred ratio is 10 to 50%. When the plaster sheet of the present invention having this diatomaceous earth-containing coating film is bonded to a moisture-absorbing and desorbing substrate, such as insulation board, a high-performance moisture-regulating and deodorizing building material can be produced as a composite material. The type of diatomaceous earth, the amount of diatomaceous earth mixed, and the amount of coating film may be any within the range that achieves the objectives of the present invention.

[0053] [Third layer: Antibacterial coating] The third antibacterial coating film 3 is formed on top of the two-layer structure of the first and second layers when the plaster sheet is constructed as a three-layer structure. It serves as the outermost coating of the plaster sheet, imparting properties such as antibacterial, mildew resistance, stain resistance, water repellency, and scratch resistance. It also maintains the alkalinity of the first plaster coating film 1 through the porous antibacterial coating film 2. Examples include two-component urethane resin paints containing acrylic polyol or polyester polyol with isocyanate, UV paints, and other paints that meet the required qualities of the plaster sheet. Oil-based or water-based paints are also acceptable. Furthermore, inorganic antibacterial agents are primarily used for antibacterial paints, and their raw material properties demonstrate long-term antibacterial and antiviral properties, making them well-known materials. Of course, by selecting the type and composition of the antibacterial material, properties such as mildew resistance, stain resistance, water repellency, and scratch resistance, which are not possible with conventional plaster walls, can also be achieved.

[0054] Methods for forming the third layer of antibacterial coating film 3 include gravure printing and painting, and painting techniques include roll coaters, knife coaters, and die coaters, with gravure coaters being particularly preferred. Furthermore, the method is not limited to printing or painting, and is not particularly limited as long as similar surface properties are obtained. Regarding surface properties, a matte finish is required to achieve the texture characteristic of the natural material of plaster; specifically, a gloss value of approximately 3 to 15 measured at a 60-degree measurement angle, which is commonly used, is preferred. Matting agents can be commercially available organic or inorganic products such as silica, glass beads, or plastic beads.

[0055] If necessary, inorganic or organic slip agents and various additives may be added. For example, the above-mentioned coating material is applied in a ratio of 2 to 10 g / m using a gravure coater. 2 A transparent, matte resinous layer is obtained by applying and drying at 150°C for 30 seconds.

[0056] The third antibacterial coating film 3 is primarily formed to cover the convex portions of the second layer, but it can also be applied to the plaster surface of the concave portions. For example, to improve the contamination resistance of the concave portions, a thin film can be applied to the concave portions. This can be achieved by varying the viscosity of the paint and the type of plate depth, and is possible through the normal operation of gravure printing equipment.

[0057] As described above, the third layer of antibacterial coating film 3 is mostly formed on the convex parts of the second layer, and partly on the first layer of plaster coating film 1 at the bottom of the groove. The amount of antibacterial coating film 3 applied to the entire sheet is 0.1 to 15 g / m per unit area of ​​the sheet. 2 It is preferable that the range is 1 to 10 g / m 2 In addition, taking into consideration the balance with the development of alkalinity from the first layer of plaster coating film 1, the area ratio of the grooves in the second layer of porous grooved coating film 2 is preferably 10 to 80% of the entire sheet, that is, the area ratio of the convex portions of the porous grooved coating film 2 where most of the antibacterial coating film 3 is applied is preferably 90 to 20%, and more preferably 80 to 50%, of the entire sheet.

[0058] In addition, when a three-layer structure is formed by forming a third layer made of an antibacterial material, the antibacterial material is concentrated more on the surface than when the antibacterial material is contained in the second layer described above, which is more rational in terms of improving the antibacterial effect. However, even when this third layer is formed, it is also possible to contain the antibacterial material in the second layer, and the antibacterial material can be added by appropriately selecting it, taking into consideration the improvement of antibacterial properties, the duration of the effect, etc.

[0059] Diatomaceous earth can also be included in either the second or third layer, or both. The inclusion of diatomaceous earth in the third layer increases the likelihood of the coating surface becoming rough (the top surface becoming rough). However, this roughness is inherent in the construction of plaster walls by plasterers, and this is suitable for cases where this effect is desired. Diatomaceous earth particles are irregular, porous particles, and the larger the particle size, the greater the effect of achieving the natural feel of a plaster wall. [Example]

[0060] The performance tests of the plaster sheet of the present invention were carried out as follows, and the results are shown in Tables 1 and 2. In Table 1, samples No. 1 and No. 2 are comparative examples of commercially available plaster sheets, No. 3, 9, and 10 are comparative examples that were created, and No. 4, 5, 6, 7, and 8 are examples of the present invention. Of the examples of the present invention, No. 4 and 5 have a two-layer structure in which a second layer is formed on top of a first layer made of plaster coating film, and No. 6, 7, and 8 have a three-layer structure in which a third layer is further formed on top of the second layer.

[0061] First, regarding the sheet substrate, test Nos. 1 and 2 were commercially available products obtained at various exhibitions (2016 and 2017). No. 1 was unprinted, while No. 2 was approximately 40% printed. Nos. 3, 4, 6, and 7 were reinforced paper of our company's quality, with only No. 3 being unprinted. No. 5 was a laminate of paper and wet-laid nonwoven fabric, and No. 9 was a wet-laid nonwoven fabric, using the "CFW-Series" manufactured by Tenma Special Paper Co., Ltd. No. 8 was a synthetic resin fiber nonwoven fabric, and No. 10 was a non-flammable paper, using the "GP-Series" manufactured by Taigalex Co., Ltd.

[0062] The plaster used in the test to form the plaster coating film 1 was "Ares Shikui" (manufactured by Kansai Paint Co., Ltd.), which was purchased by the applicant, and the tests shown in Tables 1 and 2 were carried out.

[0063] No. 3, 9, and 10 did not have a second coating layer. No. 4, 5, 6, 7, and 8 used the above-mentioned "acrylic resin." In addition, the second layer of No. 4 and 5 contained diatomaceous earth. In the performance tests in Table 1, a commercially available acrylic resin paint, acrylic resin "UC Clear NTGM / Hardener W" manufactured by DIC Corporation, was used. Nos. 4, 5, 6, 7, 8 and comparative example No. 10 were printed using a gravure printing machine, and comparative example No. 9 was printed using a Canon PIXUS-MG6230, with a printing area of ​​approximately 40%.

[0064] In Table 1, the "First Layer - Exposed Area on Plaster Coating (%)" is calculated by subtracting the "First Layer - Printed Area on Plaster Coating (%)" from 100%, since the printed area on the plaster coating is usually hidden by the plaster coating (Nos. 1, 2, 3, 9, and 10). However, with the product of the present invention, a plaster-like or other design is printed using heat-foaming capsule ink, and then a thermosetting acrylic resin coating is applied and heated. This causes the capsules in the foaming ink to foam, and the thermosetting acrylic resin blends with the printed design to form a porous layer. When the porous layer is ground away, part of the first layer plaster surface is exposed, and the printed design becomes the exposed area, so the two values ​​match (Nos. 4 to 8).

[0065] No. 3 has an exposed area of ​​94% or more on the first layer of plaster coating, and the second layer of the present invention is not present, so the plaster coating 1 is exposed across the entire surface. In other words, it shows the area where the entire surface is plaster coating, just like the commercially available product No. 1. In reality, it is difficult to express 100%, so we have used 94% or more, just like No. 1.

[0066] No. 6 is printed almost entirely in a plaster-like pattern (printed area 80-60%), in contrast to the full-plaster plaster. It shows the largest plaster pattern created by a plasterer, and is a plaster sheet with porous uneven grooves that are in sync with the printed pattern of the present invention. Nos. 4, 5, 7, and 8 show directions with minimal exposed plaster area (printed area 50-20%). This is an area that evokes the image of real plaster, and is within the range in which the effects of the present invention can be fully demonstrated.

[0067] The material used for the third layer antibacterial coating film 3 formed in Nos. 6, 7, and 8 was a thermosetting acrylic urethane resin containing antibacterial agents, silicone, delustering agents, auxiliary agents, etc.

[0068] The manufacturing method of these samples is, for example, to prepare test plaster, acrylic emulsion / calcium hydroxide / calcium carbonate / titanium pigment / silica powder / wetting agent / auxiliary agent / water (15 / 30 / 5 / 10 / 3 / 2 / 5 / appropriate amounts) are mixed and made into paint using a stirring, dispersing and kneading machine. This paint is applied at a concentration of 15-50g / m 2 This coating film was confirmed to have an alkaline pH of -12 to 14. In the performance tests shown in Table 1, a commercially available plaster paint, "Ares Shikui" manufactured by Kansai Paint Co., Ltd., was used at 30 to 45 g / m 2 The alkalinity of the plaster was 5g / m². 2 It was confirmed that the solution exhibited a strong alkaline pH of 14.

[0069] In the example of Table 1, Experiment No. 7, the sheet substrate is made of reinforced paper of 80 g / m 2 The thickness is 120 μm, and the first layer is plaster "Ares Shikui" manufactured by Kansai Paint at 45 g / m 2 The first layer of coating was then formed. Next, a heat-foaming ink made by compounding "hydrophilic gravure ink" manufactured by Dainichiseika Color & Chemicals Co., Ltd. with "acrylic resin capsules" manufactured by Nippon Phillite Co., Ltd. was used to print the area of ​​the print pattern on a gravure printing machine, with the area being approximately 40%. On top of that, an acrylic resin "UC Clear NTGM / hardener W" manufactured by DIC Corporation was applied as the second coating layer, and a heating, foaming, and grinding process was carried out to create a porous uneven grooved surface. Next, the third layer of coating was applied using "PTC-NT medium / PTC-HT slip agent / PTC hardener" manufactured by Dainichiseika Color & Chemicals Co., Ltd. in a ratio of 100 / 5 / 15, at 4-10 g / m2 using a gravure coater. 2The coating was applied and dried at 150°C for 30 seconds to form a coating film. To stabilize the plaster sheet, it was cured in a 50°C atmosphere for 50 hours to form a product of the present invention. The other samples were also prepared in the same manner.

[0070] No. 7 in Table 1 showed stable alkalinity. In other words, the effect of alkalinity as a plaster is more durable when the surface area exposed to air is reduced for the same application amount (weight), and the entire first layer of plaster coating exhibits gradual alkalinity from the porous layer to the surface, thereby reducing the surface area exposed to air. In other words, when the surface area exposed to air is smaller, the alkalinity becomes weakly alkaline, but the reaction between calcium hydroxide and carbon dioxide can be suppressed.

[0071] The physical properties (PH) of the test plaster sheets (No.-1 to 10) in Table 1 were evaluated (*-1 to *-3). The results (*-1) are shown for the case of the present invention, where litmus paper soaked in water was placed on the surface of the top coating film, and the pH was measured after 1 minute. Note that for the present invention, the measurement results are also shown for the first layer plaster coating film, the second layer porous groove coating film (for two-layer structures, the measurement was the same as on the top coating film surface), and the third layer antibacterial coating film (top coating film surface).

[0072] The "commercial plaster sheet" (Table 1, No. 1) and No. 3 (with an exposed plaster coating of "94% or more") exhibited strong alkaline properties. Also, No. 2 (with a printed area of ​​approximately 40% and an exposed plaster coating of "approximately 60% or more") also exhibited strong alkaline properties. Similarly, Table 1, Nos. 9 and 10 (wet-laid nonwoven fabrics with inkjet printing and non-combustible paper with gravure printing on 50-20% of the total surface, resulting in an exposed plaster coating of "approximately 50-80%") also exhibited strong alkaline properties. This indicates that simply reducing the exposed plaster coating by printing with a standard printed sheet is not enough to suppress the alkaline properties of the plaster.

[0073] In contrast, the products of the present invention (Nos. 4, 5, 6, 7, and 8) exhibited strong alkalinity on the first layer of plaster coating, similar to that of conventional products. However, for the two-layer structures Nos. 4 and 5, on the second layer (top coating surface), No. 4 exhibited weak alkalinity, while No. 5 exhibited moderate to weak alkalinity. This is thought to be because the convex, non-grooved portions of the second layer of the porous grooved coating of the present invention suppressed the release of strong alkalinity from the first layer of plaster coating. Furthermore, No. 5, which uses a wet-laid nonwoven fabric as the substrate, exhibited weaker alkalinity suppression of the plaster coating than No. 4, which uses reinforced paper as the substrate, due to its lower air permeability (breathability). This is thought to have resulted in moderate alkalinity.

[0074] Of the three-layer structures of the present invention, No. 6, which had an exposed area of ​​the first layer plaster coating of 80-60%, showed strong to medium alkaline on the second layer and medium alkaline on the top coating surface (on the third layer).On the other hand, No. 7 and No. 8, which had an exposed area of ​​the first layer plaster coating of 50-20%, showed weak alkaline on both the second layer and the top coating surface (on the third layer).

[0075] In addition, in the litmus paper test (*-2) after 20 minutes, all of the comparative examples of the present invention showed strong alkaline properties, whereas the two-layer structure of the present invention showed medium to weak alkaline properties in No. 4 and medium alkaline properties in No. 5, which used a substrate with a low air permeability value (breathable).

[0076] Of the three-layer structures of the present invention, No. 6, with an exposed area of ​​the first layer of plaster coating of 80 to 60%, showed strong to medium alkaline properties, while No. 7 and No. 8, with an exposed area of ​​the first layer of plaster coating of 50 to 20%, No. 7, which uses reinforced paper as the base material, showed medium to weak alkaline properties, and No. 8, which uses nonwoven fabric with a lower air permeability value than reinforced paper as the base material, showed medium alkaline properties.

[0077] In other words, the plaster sheet coated with plaster paint in a two-layer or three-layer structure having the second layer porous groove coating film of the present invention has been found to have the effect of suppressing alkalinity when wetted with water, compared to commercially available plaster sheets and comparative examples, which show strong alkalinity, and in particular, it is possible to suppress it to a weak alkalinity, making it easier to handle in everyday life.

[0078] In addition, a wet hand contact test (*-3) was conducted on Nos. 1 to 8, and it was found that in the cases of those in which the plaster was exposed over a large area as in Table Nos. 1 and 3, and in those in which the plaster was exposed over a normal printing area of ​​approximately 60%, the water that was interposed when a wet hand came into direct contact with the plaster all showed a moderate alkaline level, whereas the samples of the present invention showed a moderate alkaline to neutral level.

[0079] Furthermore, No. 6, where the first layer of plaster coating had an exposed area of ​​80-60%, showed a medium to weak alkaline, while No. 7, where the first layer of plaster coating had an exposed area of ​​50-20%, showed a neutral. Also, while the two-layer structures No. 4 and 5 showed a weak alkaline, No. 7, where the three-layer structure was able to exert water-repellent and other effects in the third layer, showed almost no alkaline effect from the plaster.

[0080] Next, durability and weather resistance were evaluated by an outdoor exposure test in which the sheet was exposed to wind and rain for 15 days, and the long-term durability and weather resistance when used as an indoor building material were estimated (*-4). The exposure test was conducted on three types of sheets: No. 1, a commercially available plaster sheet; No. 3, plaster paper; and No. 7, a plaster sheet of the present invention with an exposed area of ​​the first layer plaster coating of 50-20%.

[0081] According to the alkalinity of *-4 (15 days of outdoor exposure), the alkalinity after 15 days of outdoor exposure was strong alkaline at pH 12-14 before the exposure test for No. 1 and 3, but after the exposure test it decreased to about pH 11 and became weakly alkaline. On the other hand, the alkalinity of No. 7 plaster sheet remained stable, maintaining a weak alkaline pH of 10-11 before and after the exposure test.

[0082] Next, the contamination test was evaluated in Table 2. Samples Nos. 1, 3, 6, 7, and 8 in Table 1 were used. In the results of various staining properties (*-5 to *-7) in Table 2, No. 1 and 3 are heavily stained, while No. 6 is moderately stained, and No. 7 and 8 are less stained. In particular, No. 7 is superior in *-6 blue ink dripping property and *-7 soy sauce dripping property. This shows that the more exposed the plaster coating film is or the larger the exposed area, the worse the staining property.

[0083] Regarding the water repellency results (*-8), No. 1 and 3 had a water contact angle of less than 50°, while No. 7, the product of the present invention, showed a contact angle of 90° or more. In either case, when the exposed area of ​​the plaster was large, various water repellencies were poor. Furthermore, with the product of the present invention, even if the exposed plaster portion becomes stained, the staining will look natural and less unnatural because it will match the printed pattern. Furthermore, when comparing No. 6 and No. 7, the third coating layer is applied to the convex portion of the top surface, and the larger the coating area, the greater the water-repellent effect.

[0084] In addition, an exposure test similar to *-4 in Table 1 was conducted to estimate the long-term water repellency when used as an indoor building material (*-9). The exposure tests were conducted on No. 1, No. 3, and No. 7. After the exposure test, the water repellency of No. 1 and No. 3 was extremely poor, with almost no water being repelled. On the other hand, the plaster sheet No. 7, a product of the present invention, maintained a contact angle of approximately 50° with tap water. In other words, the No. 7 plaster sheet maintained stable performance even when exposed to direct sunlight, wind, rain, etc. outdoors.

[0085] Regarding the results of the antibacterial properties of the third coating layer (*-10), tests were conducted on No. 6 and No. 7 in accordance with JIS Z 2801, and it was found that they have sufficient antibacterial properties. This is because antibacterial coating layer 3 is a thermosetting acrylic urethane resin that contains antibacterial agents, silicone, delustering agents, auxiliary agents, etc., and it is thought that the stain resistance, water repellency, antibacterial properties, and abrasion resistance will be effective for a long time, especially on the convex parts.

[0086] In the results of a relative comparison of scratch resistance using abrasive steel wool in Table 2 (*-11), Nos. 1 and 3 were easily scratched, while No. 7 was not scratched. The third layer of topcoat paint also possesses the coating film properties (JAS: in-house standard based on the Japanese Agricultural Standards) required for interior materials such as housing construction materials and furniture, and it is believed that the larger the coating area, the stronger the coating film becomes.

[0087] [Table 1]

[0088] [Table 2]

[0089] The results of the above examples show that the commercially available products No. 1 and No. 2 cannot control the alkalinity of the plaster regardless of whether they are printed or not, whereas the plaster sheet of the present invention can adjust the alkalinity (by gently exerting the strong alkalinity inherent in the plaster) by changing the printed area of ​​the porous grooves. For example, the conventional product No. 2 is strongly alkaline with the top coat even though the printed area is about 40%, while the plaster sheet of the present invention, No. 5, maintains a weak alkalinity with a printed area of ​​50 to 20%.

[0090] From the above examples, it can be seen that the plaster sheet of the present invention maintains the performance and texture of plaster applied with a trowel by a plasterer, while also improving practically the stain resistance, water repellency, scratch resistance, and strong alkalinity that are said to be inherent weaknesses of plaster. [Explanation of symbols]

[0091] 1. Plaster coating 2 Porous trench coating 3 Antibacterial coating 4 Sheet substrate A Antibacterial (due to antibacterial coating) B. Alkaline (due to plaster coating) C. Humidity control and deodorizing properties (due to diatomaceous earth) D. Antibacterial (using antibacterial materials)

Claims

1. A plaster sheet having a first layer and a second layer in this order on a sheet substrate, the first layer being made of a plaster coating film mainly composed of calcium hydroxide, the second layer being made of a portion on the first layer where heat-foamable capsule-type ink is printed and a paint portion other than the heat-foamable capsule-type ink, and the plaster sheet is characterized in that a porous groove portion having a perforation portion that partially exposes the plaster coating film of the first layer is formed in the portion where the heat-foamable capsule-type ink is printed by grinding processing after heating and foaming the heat-foamable capsule-type ink.

2. 2. The plaster sheet according to claim 1, wherein the area of ​​the porous groove portion in the second layer is 10 to 80% of the entire sheet.

3. 3. A plaster sheet according to claim 1 or 2, characterized in that the second layer contains an antibacterial material.

4. A plaster sheet according to any one of claims 1 to 3, characterized in that it has a third layer consisting of an antibacterial coating film applied on the paint portion other than the heat-foaming capsule-type ink of the second layer.

5. The coating amount of the third layer is 0.1 to 15 g / m 2 The plaster sheet described in claim 4, characterized in that its area is 90 to 20% of the entire sheet base material, and the third layer coating is a coating of acrylic paint containing an inorganic antibacterial agent.

6. 6. The plaster sheet according to claim 1, wherein the second layer and / or the third layer contains diatomaceous earth.

7. A building material comprising a plaster sheet according to any one of claims 1 to 6 attached to a substrate.

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