Method for forming three-dimensional wood grain on board surface, resulting board and application

Abstract

The present invention relates to the field of surface structure preparation, and in particular to a method for forming three-dimensional wood grain on the surface of a board, the resulting board and its application, wherein the method comprises at least the following steps: coating a resin liquid on at least a portion of the surface of an ink layer and curing the resin liquid to form a wood grain bottom layer; covering at least a portion of the surface of the wood grain bottom layer with at least one layer of resin liquid; applying an embossing liquid along the wood grain pattern of the ink layer on at least a portion of the surface of the resin liquid to form an embossing layer; curing the resin liquid in the area other than the embossing layer and removing the embossing layer, thereby forming a three-dimensional wood grain layer on the surface of the wood grain bottom layer. The process of the present invention can prepare a three-dimensional wood grain on the surface of the board with a visual and tactile sense closer to real wood grain, so as to meet people's demand for a more realistic combination of visual and tactile senses.

Description

Technical Field

[0001] The present invention relates to the field of surface structure preparation, and in particular to a method for forming three-dimensional wood grain on a board surface, a board containing the three-dimensional wood grain, a method for forming the board, and applications of the board. Background Art

[0002] At present, in order to obtain a texture similar to natural wood on the surface of artificial boards or non-wood boards, a layer of imitation wood two-dimensional flat image is usually formed on the surface of the board by printing or printing, so as to visually meet people's visual needs for wood materials.

[0003] For example, the patent with publication number CN 101659073 B discloses a wood grain treatment process for the surface of a waterproof floor substrate, which is to print simulated wood grain on the surface of the wood plastic floor, and then add a wear-resistant layer on the simulated wood grain, so that the wood grain pattern is protected and the wood grain texture effect is maintained for a long time. However, this type of board with only a two-dimensional flat image printed on the surface can no longer meet people's demand for a more realistic visual and tactile combination.

[0004] Therefore, forming three-dimensional wood grain on the surface of a board material that corresponds to a two-dimensional plane image and has a touch that is closer to that of wood is currently a common concern in the art.

[0005] In the prior art, a variety of different technical solutions have been proposed to form a three-dimensional structure on the surface of a substrate. Conventional methods generally include an upward stacking method and a downward indentation method.

[0006] Taking the upward stacking method as an example, the related technology can refer to the following patents:

[0007] The patent with publication number CN 112455110 A discloses a process for producing wooden flooring by inkjet printing. The patent can form convex three-dimensional wood grain on the surface of the printed pattern texture by continuously printing additive ink on the surface of the printed pattern texture. However, it was found from the actual test process that due to the certain fluidity of the ink before solidification, its molding height is limited, and as the resin flows, the texture angle of the three-dimensional wood grain prepared by this upward stacking method is more rounded than that of the natural wood grain, resulting in a very obvious difference between its actual effect and the natural wood grain, and it is difficult to achieve the visual effect and touch feel of natural solid wood.

[0008] Taking the downward indentation method as an example, the related technology can refer to the following patents:

[0009] The patent with publication number CN 110177691 B discloses a method and device for producing embossing on a substrate by means of digital printing technology. In this method, after applying embossing liquid on a non-polymerized resin layer, the resin is subsequently polymerized by means of UV curing, and then the embossing liquid is removed to form a three-dimensional surface. The three-dimensional wood grain prepared in this way has a certain improvement in visual effect and touch feel compared to the stacking method. However, in the actual test process, it was found that after the three-dimensional wood grain prepared by this method was formed on the surface of the ink layer with a wood grain pattern, its clarity would be greatly reduced, which is specifically manifested in the phenomenon that its surface will appear white and have a large color difference.

[0010] The patent with the publication number CN 112996649 A discloses a method for manufacturing a three-dimensional structure on the surface of a flat substrate, the resulting substrate, and a device for producing the substrate according to the method, wherein a material for forming a wood grain seam is dripped onto the surface of the substrate in advance, and then a curable resin is applied to the area of ​​the substrate surface not covered with the material for forming the wood grain seam, and then the material for forming the wood grain seam is removed after the resin is cured, thereby forming a wood grain seam in the cured resin. However, the depth of the wood grain seam is always the distance between the upper surface of the cured resin and the surface of the substrate, that is, the depth of each wood grain seam is consistent. However, the depth of the gap on the surface of a real wooden board is variable, so the depth of the wood grain seam formed by this technology is greatly different from the actual situation, and thus there is a problem of unreality.

[0011] In summary, in order to measure the similarity between the three-dimensional wood grain and the natural wood grain, the dimensions that need to be considered usually include: (1) the similarity between the width and depth of the three-dimensional wood grain and the natural wood grain; (2) the correspondence between the three-dimensional wood grain and the bottom two-dimensional plane structure; (3) the color visual effect presented by the combination of the three-dimensional wood grain and the bottom two-dimensional plane. At present, in the process of forming three-dimensional wood grain, the existing public technology often pays more attention to the combination of dimension (1) and dimension (2).

[0012] Among them: for dimension (1), the width and depth of the three-dimensional wood grain can be determined by controlling the amount and position of the material in the process of forming the three-dimensional wood grain. For example, the width of the wood grain can be determined by the width of the stacked structure or the breadth during the downward excavation process or the area of ​​the corrosive liquid. The depth of the three-dimensional wood grain can be determined by the height of the upward stacking and the force of the downward excavation. The more obvious the difference in the width and depth of the three-dimensional wood grain, the more three-dimensional the structure it presents, and the closer the effect it can present from the visual and tactile senses to the natural wood grain.

[0013] Regarding dimension (2), the correspondence between the three-dimensional wood grain and the two-dimensional plane structure at the bottom can be controlled by controlling the printing accuracy, for example, involving the control of the computer program and the coordination and regulation between the computer and the molding equipment. It also involves various physical and chemical properties of the material itself, such as its own viscosity, surface energy, and diffusion coefficients between different materials. The higher the correspondence between the three-dimensional wood grain and the two-dimensional plane structure at the bottom, the closer the three-dimensional structure can be to the surface wood grain structure of real solid wood.

[0014] Regarding dimension (3), there are currently no more documents and technologies that disclose the relationship between three-dimensional structure and visual effect. Some of the technologies that exist only include matte or glossy effects such as three-dimensional wood grain, while the technology that truly achieves the visual effect of real wood grain has not yet appeared.

[0015] Therefore, there is no precedent in the currently disclosed technology that takes dimension (3) into consideration while achieving dimension (1) and dimension (2). Therefore, how to take these three dimensions into consideration at the same time is the key point to obtain a texture similar to that of natural wood on the surface of artificial board or non-wood board. Summary of the invention

[0016] The present invention aims to overcome the defect that the method of forming three-dimensional wood grain on the surface of a board in the prior art cannot obtain a texture close to that of natural wood, and provides a method for forming three-dimensional wood grain on the surface of a board, the resulting board and its application.

[0017] To achieve the above-mentioned purpose, the present invention is implemented by the following technical solutions:

[0018] In a first aspect, the present invention first provides a

[0019] The method for forming three-dimensional wood grain on the surface of a board comprises at least the following steps:

[0020] (S.1) a step of covering at least a portion of the surface of the plate with ink, thereby forming an ink layer having a wood grain pattern;

[0021] (S.2) a step of covering at least a portion of the surface of the ink layer with a resin liquid;

[0022] (S.3) a step of solidifying at least a portion of the resin liquid on the surface of the ink layer to form a wood grain bottom layer;

[0023] (S.4) a step of covering at least a portion of the surface of the wood grain bottom layer with at least one layer of resin liquid;

[0024] (S.5) applying embossing liquid to at least a portion of the surface of the resin liquid on the wood grain bottom layer along the wood grain pattern of the ink layer, so that the embossing liquid and / or at least a portion of the resin liquid mixed with the embossing liquid and / or at least a portion of the resin liquid covered by the embossing liquid forms an embossing layer;

[0025] (S.6) a step of solidifying the resin liquid except for the embossed layer formed in the previous step;

[0026] (S.7) A step of removing the embossed layer to form a three-dimensional wood grain layer on the surface of the wood grain base layer.

[0027] Preferably, the amount of the resin liquid covering the surface of the wood grain bottom layer in step (S.4) is greater than or equal to 150 g / m 2 .

[0028] Preferably, in the step (S.4), at least a portion of the surface of the wood grain bottom layer is covered with at least two layers of resin liquid.

[0029] Preferably, in the process of covering at least a portion of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid, it also includes a transition treatment step of stopping the application of force to the resin liquid after the wood grain bottom layer is completely covered by the previous layer of resin liquid, and covering with the next layer of resin liquid after the transition treatment step is completed.

[0030] Preferably, in the process of covering at least a portion of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid, the directions of force applied to the any two adjacent layers of resin liquid are opposite.

[0031] Preferably, the plate material completes steps (S.1) to (S.6) in sequence while being transported in a fixed direction.

[0032] Preferably, in the step (S.5), the embossing liquid is applied to the surface of the resin liquid and / or penetrates downward into the interior of the resin liquid.

[0033] Preferably, the curing method of the covering resin liquid in the steps (S.2) and (S.4) includes any one of photocuring, thermal curing or electron beam curing.

[0034] Preferably, the resin liquid includes at least a photo-crosslinking resin and a photoinitiator.

[0035] Preferably, the photo-crosslinking resin includes any one or more combinations of unsaturated polyester, epoxy resin, acrylic resin, acrylic modified polyurethane resin, acrylic modified silicone resin, acrylic modified epoxy resin, water-based epoxy acrylate, water-based polyurethane acrylate, and water-based polyester acrylate.

[0036] Preferably, the photoinitiator includes any one of a free radical polymerization initiator, a cationic polymerization initiator, an energy transfer initiator, and an ion reaction initiator.

[0037] Preferably, the embossing liquid in the step (S.5) contains at least a polymerization inhibitor for preventing the polymerization of the resin liquid.

[0038] In this preferred embodiment, an inhibitor is added to the embossing liquid, which can quench the free radicals generated by the decomposition of the photoinitiator under light, thereby effectively preventing the polymerization of the resin liquid containing the inhibitor, thereby obtaining an embossing layer that is easy to remove.

[0039] Preferably, the resin liquid at least includes a thermosetting resin.

[0040] Preferably, the thermosetting resin includes one or more combinations of epoxy resin, phenolic resin, melamine formaldehyde resin, furan resin, unsaturated polyester resin, silicone resin, and polybutadiene resin.

[0041] Preferably, the resin solution further includes a curing agent.

[0042] Preferably, the step (S.4) further comprises a step for providing kinetic energy for the embossing liquid to penetrate downward into the resin liquid.

[0043] Preferably, the embossing liquid contains a curable resin.

[0044] Preferably, the curable resin contained in the embossing liquid has a surface energy lower than the surface energy of the three-dimensional wood grain layer after curing.

[0045] Preferably, the curable resin contained in the embossing liquid has a surface energy lower than 100 mN / m after curing.

[0046] Preferably, the curable resin contained in the embossing liquid includes any one of fluorocarbon resin, fluorosilicone resin or silicone resin.

[0047] Preferably, the density of the embossing liquid is greater than the density of the resin liquid.

[0048] Preferably, the embossing liquid further comprises a density regulator for adjusting the density of the embossing liquid.

[0049] Preferably, the density regulator is an inorganic solid additive.

[0050] Preferably, the density regulator is nano calcium carbonate, nano silicon dioxide or the like.

[0051] Preferably, the embossing liquid comprises at least two embossing liquids with different surface tensions.

[0052] Preferably, the following are arranged in sequence between the board and the wood grain bottom layer:

[0053] A primer layer used to improve the bonding performance of the board surface;

[0054] A color paint layer disposed on the surface of the primer layer to cover the color of the substrate;

[0055] An ink layer located on the surface of the paint layer to form a wood grain pattern.

[0056] Preferably, the outer surface of the three-dimensional wood grain layer is further covered with a topcoat layer, and at least a portion of the topcoat layer is lower than the upper surface of the three-dimensional wood grain layer.

[0057] In a third aspect, the present invention further provides a method for preparing the board having three-dimensional wood grain, which at least comprises the steps of preparing a wood grain base layer and a three-dimensional wood grain layer according to the method described above.

[0058] As a preference, the method further comprises the following steps:

[0059] A step of covering at least a portion of the surface of the plate with a primer and curing the primer layer;

[0060] The step of covering at least a portion of the surface of the primer layer with a color paint and curing the primer layer to obtain a color paint layer;

[0061] The step of covering at least a portion of the surface of the color paint layer with ink having a wood grain pattern and curing the ink layer;

[0062] The step of making at least a portion of the surface of the ink layer cover the wood grain base layer and the three-dimensional wood grain layer prepared according to the method described above;

[0063] The step of covering at least a portion of the surface of the three-dimensional wood grain layer with a topcoat and curing the topcoat layer.

[0064] Preferably, the coverage of the primer is 10-15 g / m 2 ;

[0065] The coverage of the paint is 15-20g / m 2 ;

[0066] The coverage of the ink is 6-8g / m 2 ;

[0067] The coverage of the topcoat is 20-30g / m 2 .

[0068] Preferably, the paint layer is white.

[0069] Preferably, the paint contains at least a photo-crosslinking resin, a photoinitiator and white pigment powder.

[0070] In a fourth aspect, the present invention further provides the use of the board with three-dimensional wood grain in floors, decorative wall panels or ceiling panels.

[0071] Therefore, the present invention has the following beneficial effects:

[0072] (1) The process of the present invention can produce three-dimensional wood grain on the surface of the board, which is closer to real wood grain in terms of visual and tactile sense, so as to meet people's demand for a more realistic combination of visual and tactile sense;

[0073] (2) The preparation process of the present invention can effectively improve the stability of the color and pattern of the plate;

[0074] (3) The plate material prepared by the preparation process of the present invention has a longer service life and a lower defective rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 Schematic representation of steps (S.1) to (S.7) of the method of the present invention.

[0076] Figure 2 This is a schematic reproduction diagram of steps (S.6)-(S.8) in Example 1 of the present invention.

[0077] Figure 3 This is a schematic diagram of the three-dimensional structure of the three-dimensional wood grain prepared in Example 1 of the present invention.

[0078] Figure 4 This is a schematic diagram of the top view of the three-dimensional wood grain prepared in Example 1 of the present invention.

[0079] Figure 5 This is a schematic diagram of the three-dimensional structure of the three-dimensional wood grain prepared in Comparative Example 1 of the present invention.

[0080] Figure 6 This is a schematic diagram of the top view of the three-dimensional wood grain prepared in Comparative Example 2 of the present invention.

[0081] Figure 7 This is a schematic diagram of the three-dimensional structure of the three-dimensional wood grain prepared in Comparative Example 3 of the present invention.

[0082] Figure 8 This is a schematic reproduction diagram of steps (S.6)-(S.8) in Example 2 of the present invention.

[0083] Fig. 9 It is a schematic reproduction diagram of the manner of coating the resin liquid on the surface of the wood grain bottom layer in Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0084] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments of the specification. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0085] like Figure 1 As shown, in a first embodiment of the present invention, the present invention first provides a method for forming three-dimensional wood grain on the surface of a board, which at least includes the following steps:

[0086] (S.1) a step of covering at least a portion of the surface of the plate with ink, thereby forming an ink layer having a wood grain pattern;

[0087] (S.2) a step of covering at least a portion of the surface of the ink layer with a resin liquid;

[0088] (S.3) a step of solidifying at least a portion of the resin liquid on the surface of the ink layer to form a wood grain bottom layer;

[0089] (S.4) a step of covering at least a portion of the surface of the wood grain bottom layer with at least one layer of resin liquid;

[0090] (S.5) applying embossing liquid to at least a portion of the surface of the resin liquid on the wood grain bottom layer along the wood grain pattern of the ink layer, so that the embossing liquid and / or at least a portion of the resin liquid mixed with the embossing liquid and / or at least a portion of the resin liquid covered by the embossing liquid forms an embossing layer;

[0091] (S.6) a step of solidifying the resin liquid except for the sacrificial layer formed in the previous step;

[0092] (S.7) A step of removing the embossed layer to form a three-dimensional wood grain layer on the surface of the wood grain base layer.

[0093] The principle of the three-dimensional wood grain formed on the surface of the board in the present invention is the same as the downward indentation method described in the background technology. Compared with the upward stacking method, the width of the texture formed is controllable and the depth is longer, so the three-dimensional effect is stronger. At the same time, there will be no deformation of the wood grain during the printing process, so the printing accuracy is higher. However, in the process of conventionally forming three-dimensional wood grain using the downward indentation method, a part of the ink layer will be exposed in the process of removing the embossed layer to obtain the three-dimensional wood grain layer. This part of the exposed ink layer is easily worn or even peeled off by external force. Therefore, in the process of using a machine to remove the embossed layer, it is necessary to consider the depth of downward removal to prevent the wear of the ink layer, which makes it difficult to increase the depth of the three-dimensional wood grain layer.

[0094] In the process of preparing the three-dimensional structure, the surface of the ink layer is first covered with a wood grain bottom layer obtained by curing the resin liquid, and then a three-dimensional wood grain layer is formed again on the surface of the wood grain bottom layer. Due to the existence of the wood grain bottom layer, in the process of removing the embossed layer and forming the three-dimensional wood grain layer, the ink layer will not be exposed to the outside, but will be covered by the wood grain bottom layer, so that the ink layer will not be worn or peeled off due to the action of external force. Therefore, the maximum downward digging can be achieved in the process of mechanically removing the embossed layer, thereby ensuring that the depth of the three-dimensional wood grain layer can be effectively increased.

[0095] In addition, in order to make the board containing three-dimensional wood grain prepared by the present invention obtain a texture similar to that of natural wood, in addition to considering the wear of the ink layer and the depth of the three-dimensional wood grain layer, it is also necessary to consider the correspondence between the bottom ink layer and the upper three-dimensional wood grain layer, that is, the alignment problem between the two. Regarding the alignment problem, the applicant found that the following influencing factors will cause the ink layer and the upper three-dimensional wood grain layer to have misaligned defects: (1) During the preparation of the upper three-dimensional wood grain layer, the three-dimensional wood grain layer or the ink layer is deformed due to the shrinkage of the resin material itself during the curing process; (2) During the preparation of the three-dimensional wood grain layer, the compatibility between the embossing liquid and the resin liquid is insufficient, resulting in the depth, width and edge morphology of the three-dimensional wood grain layer not meeting expectations. The applicant found that only after considering the above two factors at the same time can a texture similar to that of natural wood be truly obtained.

[0096] Regarding the influencing factor (1), the applicant found that during the curing process of the resin layer, since the energy (UV or heat) used to cure the resin liquid is usually input from the top of the resin liquid, the resin liquid at the top will cure first, while the resin liquid at the bottom will cure later. Since the resin liquid is often accompanied by a certain volume shrinkage during the curing process, a certain internal stress will be generated. These internal stresses will be superimposed downward, so that a maximum value will be reached at the bottom of the resin liquid. If the resin liquid is directly in contact with the ink layer at this time, once the maximum internal stress is greater than the bonding force between the ink layer and the surface of the board, it will cause the ink layer and the surface of the board to slip, and then make it difficult for the ink layer at the bottom to correspond to the three-dimensional wood grain at the top, thereby causing the problem of misalignment, which seriously affects the visual effect of the board. In addition, when the amount of resin liquid applied above the ink layer is large, the ink layer and the surface of the board may even peel off, which seriously reduces the yield rate of the product.

[0097] Therefore, in order to overcome the above problems, in the present invention, at least a portion of the surface of the ink layer is first covered with resin liquid and this portion of the resin liquid is first solidified to form a wood grain base layer. Since the amount of this portion of the resin liquid is small at this time, the internal stress generated after solidification is weak and will not affect the ink layer and the surface of the board.

[0098] Since the resin liquid used to form the three-dimensional wood grain layer is further covered on the wood grain base layer and solidified to obtain the three-dimensional wood grain layer, the affinity and adhesion between the wood grain base layer and the three-dimensional wood grain layer are strong, so there will be no slippage and peeling problems between the two. And because the wood grain base layer has a high mechanical strength after solidification, the internal stress generated by the three-dimensional wood grain layer during solidification is not enough to cause the wood grain base layer to deform, and the internal stress generated by the three-dimensional wood grain layer during solidification will not be transferred to the ink layer located below the wood grain base layer. Therefore, by adding step (S.3), the problem of misalignment between the three-dimensional wood grain layer and the ink layer in the subsequent steps (S.4) to (S.7) can be prevented to a certain extent.

[0099] As for the influencing factor (2), we need to further improve the compatibility between the embossing liquid and the resin liquid to improve the morphological stability of the embossing layer formed after the embossing liquid enters the resin liquid. In this regard, the prior art has adopted the step of adding embossing liquid to the incompletely cured resin layer. However, from the actual test results, due to the high viscosity of the incompletely cured resin layer itself, it is difficult for the embossing liquid to enter the resin layer. This brings the following problems: (1) The depth of the embossing liquid entering the resin layer is low, resulting in a low depth of the final wood grain, which makes the three-dimensional effect of the overall three-dimensional wood grain layer poor; (2) Due to the high viscosity of the incompletely cured resin layer, the embossing liquid is more likely to accumulate on the surface of the incompletely cured resin layer after application, making it easier for the embossing liquid to diffuse on the surface of the resin layer, making it difficult for the shape and width of the final wood grain to match the ink layer below, thereby causing the problem of inaccurate pattern; (3) The incompletely cured resin layer has weak fluidity, so it is difficult to blend with the embossing liquid in a short time, resulting in the formation of three (4) Since the viscosity of the incompletely cured resin layer is relatively high, even after it is mixed with the embossing liquid, the viscosity of the embossed layer is relatively high. Although the embossed layer cannot be completely cured in the subsequent curing process, its viscosity can still be improved to a certain extent. Therefore, these high-viscosity embossed layers are difficult to be removed completely in the subsequent mechanical removal process, so there will often be a certain amount of residue, which further leads to the problem of unclear and blurred wood grain texture, which further widens the gap between its texture and the actual natural wood material.

[0100] Therefore, in addition to adding step (S.3) in the preparation process, the present invention also adopts the technical solution of applying the embossing liquid directly to the surface of the uncured resin liquid in the preparation process (i.e., step (S.5)). Compared with applying the embossing liquid to the semi-cured resin layer, by changing this step, it can bring the following beneficial effects: (1) Since the uncured resin liquid has a low viscosity, it has good fluidity. After the embossing liquid is applied to the resin liquid, it can smoothly enter the resin liquid downward, thereby greatly improving the depth of the prepared wood grain and effectively improving the three-dimensional effect of the three-dimensional wood grain layer. (2) At the same time, since the embossing liquid can penetrate into the resin liquid, it avoids the embossing liquid from diffusing on the surface of the uncured resin liquid, so that the shape and width of the wood grain finally formed can match the ink layer below, thereby effectively improving the accuracy of the pattern. (3) Since the resin liquid and the embossing liquid have a good mixing effect, the embossing liquid or the embossing layer obtained by mixing the embossing liquid and the resin liquid has a more neat and sharp edge, so the prepared three-dimensional wood grain layer is closer to the natural wood grain. (4) Since the embossing liquid or the embossing layer obtained by mixing the embossing liquid with the resin liquid still has a low viscosity after curing, it is easier to remove after curing, and no residue will be left after removing the embossing layer, so the formed wood grain is cleaner and the edge is sharper.

[0101] Therefore, the present invention adopts the method of combining step (S.3) and step (S.5) to connect the functions and characteristics of the wood grain base layer, resin liquid and embossing liquid in series, thereby effectively overcoming the problem in the prior art that the morphological structure of the three-dimensional wood grain layer is too different from the natural wood grain, and there is misalignment between the three-dimensional wood grain layer and the ink layer below.

[0102] In addition, generally speaking, after the ink layer is covered with other transparent resin layers, the clarity of the board surface will decrease visually, and the decrease in clarity will increase with the increase in the thickness or number of resin layers on the ink layer. However, the applicant unexpectedly found that by adding a wood grain bottom layer at the bottom of the three-dimensional wood grain layer through the method of the present invention, the clarity problem will be improved to a certain extent.

[0103] After studying this, the applicant found that after forming a three-dimensional wood grain layer on the surface of the ink layer, it can visually form a series of miniature "lenses" effect, which can magnify the pattern below to a certain extent. However, when the three-dimensional wood grain layer is directly attached to the ink layer, due to its focal length, it will produce a certain blur in the visual effect, resulting in poor clarity. After the present application first sets a layer of wood grain bottom layer under the three-dimensional wood grain layer, it can adjust the focal length of the three-dimensional wood grain layer, thereby effectively improving the clarity of the wood grain.

[0104] Therefore, in summary, the method in the present application can obtain a board with three-dimensional wood grain that has a stronger three-dimensional effect, is more accurately aligned with the ink layer, and has a texture closer to that of actual natural wood materials.

[0105] In another preferred embodiment of the present invention, the amount of the resin liquid covering the surface of the wood grain bottom layer in step (S.2) is 40-50 g / m 2 .

[0106] In another preferred embodiment of the present invention, the amount of the resin liquid covering the surface of the wood grain bottom layer in step (S.4) is greater than or equal to 150 g / m 2 .

[0107] The applicant found in actual exploration that in order to make the three-dimensional wood grain on the surface of the board closer to the feel of natural wood, it is necessary to control the coating amount of the resin liquid used to form the three-dimensional wood grain. After testing, it was found that only the total coating amount of the resin liquid used in the wood grain bottom layer and the three-dimensional wood grain layer was greater than 200g / m 2 When the coating is more than 200g / m 2 After the above resin liquid is applied, it will cause the bottom of the wear-resistant layer to be difficult to solidify instantly, resulting in poor bonding between the three-dimensional wood grain and the ink layer on the surface of the board, and easy peeling between the three-dimensional wood grain and the substrate.

[0108] In order to achieve the smooth curing of a large amount of resin liquid and enhance the bonding strength between the three-dimensional wood grain and the board, it is necessary to increase the curing power used during curing. However, the provision of high power will generate more waste heat during the curing process. The waste heat generated will cause deformation of the board and yellowing or aging of the resin liquid. Therefore, this method of increasing the curing power is not practical.

[0109] After studying the three-dimensional wood grain after curing, the applicant found that the three-dimensional wood grain actually contains two functional areas in the longitudinal direction, including: (1) a bonding area for bonding with the board, i.e., the wood grain bottom layer in this application; (2) a functional area for forming a three-dimensional structure, i.e., the three-dimensional wood grain layer in this application. The wood grain bottom layer does not require much resin, while the applicant has calculated that the amount of resin required for the three-dimensional wood grain layer is 150g / m 2 Only when the above is achieved can the feel of natural wood and better wear resistance be achieved.

[0110] Therefore, the present invention applies a first layer of resin liquid on the surface of the board, and after curing it, obtains a wood grain bottom layer. Since the amount of resin liquid used to form the wood grain bottom layer is not large, it can be completely cured under conventional curing power, so that the bonding strength between the wood grain bottom layer and the board is effectively improved, and there will be no peeling problem during use. Subsequently, the resin coating amount of the overall three-dimensional wood grain on the surface of the wood grain bottom layer is increased to 150g / m 2 The above ensures the three-dimensional sense of the three-dimensional wood grain.

[0111] In another preferred embodiment of the present invention, at least a portion of the surface of the wood grain base layer in the step (S.4) is covered with at least two layers of resin liquid.

[0112] In another preferred embodiment of the present invention, in the process of covering at least a portion of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid, it also includes a transition treatment step of stopping the application of force to the resin liquid after the wood grain bottom layer is completely covered by the previous layer of resin liquid, and covering with the next layer of resin liquid after the transition treatment step is completed.

[0113] As mentioned above, in order to ensure the three-dimensional effect of the wood grain in this application, at least 150g / m 2 Therefore, the focus of this application is shifted to how to form a resin coating amount of 150g / m on the surface of the wood grain bottom layer. 2 The three-dimensional wood grain layer above.

[0114] At present, the most common way to apply the resin liquid is to use a roller coater for coating. The applicant has tried to apply up to 150g / m2 of the wood grain bottom layer at one time. 2 The above resin liquid, but the applicant found that this one-time coating method requires too much resin liquid to be loaded on a single roller. If a conventional roller is used, the resin liquid will flow downward, thereby failing to complete normal production.

[0115] Therefore, in order to solve the above problems, the present invention adopts a two-roller distribution coating method, so that each roller coats a layer of resin liquid, so that the total amount of resin in the two layers of resin liquid is greater than 150g / m 2 This method not only realizes the coating of a large amount of resin, but also reduces the resin load pressure of each roller.

[0116] In the prior art, in order to achieve multi-roll coating, a roller coater with two rollers in parallel is usually used. The two rollers of the roller coater are usually matched with one positive roller and one reverse roller. When the first roller coats the resin liquid on the surface of the plate and pushes the substrate forward, it will generate a certain force on the plate and the uncured resin liquid layer attached to the surface of the plate along the plate conveying direction. This force combined with the bristle structure on the roller surface will cause a certain deformation on the surface of the resin liquid. Before the first layer of resin liquid is leveled, the second roller has already taken over the plate coated with uncured resin liquid, which will generate a force opposite to the conveying direction of the plate on the uncured resin liquid. Therefore, this force will also cause the second layer of resin liquid to be deformed in the opposite direction. At the same time, since there is a certain speed difference between the second roller and the first roller, the deformation between the first layer of resin liquid and the second layer of resin liquid cannot be offset. Instead, the deformation of the two layers of resin liquid will be superimposed on each other, further exacerbating the appearance of marks on the resin liquid. After curing, these marks will be fixed, seriously affecting the visual effect of the final product. The production of this mark will cause obvious defects in the appearance of the finished product, especially the finished product with shallow texture. That is, when viewed from a distance, a blockage can be found in the middle of the part coated with resin liquid.

[0117] Therefore, based on the existing roller coating machine, the present application adds a transition treatment step of stopping the application of force to the resin liquid during the process of covering at least a part of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid. In this way, when the board passes through the first roller, after the first roller finishes applying force to the board as a whole, before being transported to the second roller, no force will be applied to the entire board, and then after a long distance, it is conducive to the leveling of the first layer of resin liquid. At this time, the board is coated from beginning to end by the second roller again. At this time, since the deformation of the second layer of resin liquid is small, it can be quickly leveled before curing, thereby eliminating the influence of the force of the two rollers on the resin liquid and the speed difference on the surface morphology.

[0118] In another preferred embodiment of the present invention, in the process of covering at least a portion of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid, the directions of force applied to the any two adjacent layers of resin liquid are opposite.

[0119] As can be seen from the above discussion, the roller coater will generate a certain force on the resin liquid when rolling. Since the resin liquid usually contains a high molecular polymer or prepolymer, and its molecular chain segment is relatively long, it will generate a certain elastic deformation and orientation force under the action of external force. Since the overall process time from coating to curing of the resin liquid is relatively short, the molecular chain segment of the high molecular polymer in the resin liquid is often cured before it returns to the initial state, resulting in a large internal stress in the middle of the three-dimensional wood grain layer after curing, which in turn leads to the phenomenon that cracks are easily generated in the middle of the three-dimensional wood grain layer after curing. Therefore, in order to reduce the generation of internal stress in the middle of the three-dimensional wood grain layer, the present application specifically adjusts the force direction of the two rollers on any two adjacent layers of resin liquid in the process of at least a part of the surface of the wood grain bottom layer being covered with any two adjacent layers of resin liquid, so that during the operation of the second roller, it can provide a force opposite to the internal stress of the uncured second wear-resistant layer, thereby weakening or offsetting the original internal stress of the three-dimensional wood grain layer, thereby reducing the probability of cracking in the middle of the three-dimensional wood grain layer after curing.

[0120] In another preferred embodiment of the present invention, the sheet material completes steps (S.1) to (S.6) in sequence during the process of being transported and moved along a fixed direction.

[0121] In another preferred embodiment of the present invention, in the step (S.5), the embossing liquid is applied to the surface of the resin liquid and / or penetrates downward into the interior of the resin liquid.

[0122] In the present application, there are various principles for forming an embossing layer by adding embossing liquid on the surface of resin liquid, including but not limited to ultraviolet covering method, free radical absorption method or volume occupation method.

[0123] Among them: the ultraviolet covering method is suitable for UV-cured resin liquid. Its principle is to cover the surface of the uncured resin liquid with a layer of embossing liquid that can prevent ultraviolet rays from penetrating, so that the resin liquid below the embossing liquid can remain in a liquid and uncured state, so that this part of the uncured resin liquid forms an embossing layer, which is then removed by mechanical cleaning or solution washing in the subsequent processing process, thereby obtaining a three-dimensional wood grain layer with a wood grain-like structure.

[0124] The free radical absorption law is applicable to the resin liquid of the free radical polymerization principle. The principle is to penetrate into the surface of the uncured resin liquid or downward into the interior of the uncured resin liquid, so as to absorb the free radicals used to polymerize the resin liquid to undergo free radical polymerization and solidification, so that the resin liquid in the part containing the embossing liquid can remain in a liquid and uncured state, so that this part of the uncured resin liquid forms an embossing layer, which is then removed by mechanical cleaning or solution washing in the subsequent processing process, thereby obtaining a three-dimensional wood grain layer with an imitation wood grain structure.

[0125] The volume occupancy rule means that when the embossing liquid penetrates downward into the uncured resin liquid, it squeezes out the uncured resin liquid, so that the occupied volume only contains the embossing liquid. The embossing liquid can be polymerizable or non-polymerizable. Finally, the embossing liquid is cleaned and removed through the principle of mechanical or solvent cleaning to obtain a three-dimensional wood grain layer with a simulated wood grain structure.

[0126] In another preferred embodiment of the present invention, the curing method of the covering resin liquid in the steps (S.2) and (S.4) includes any one of photocuring, thermal curing or electron beam curing.

[0127] In another preferred embodiment of the present invention, the resin solution at least includes a photo-crosslinking resin and a photoinitiator.

[0128] In another preferred embodiment of the present invention, the photo-crosslinking resin includes any one or more combinations of unsaturated polyester, epoxy resin, acrylic resin, acrylic modified polyurethane resin, acrylic modified silicone resin, acrylic modified epoxy resin, water-based epoxy acrylate, water-based polyurethane acrylate, and water-based polyester acrylate.

[0129] In another preferred embodiment of the present invention, the photoinitiator includes any one of a free radical polymerization initiator, a cationic polymerization initiator, an energy transfer initiator, and an ion reaction initiator.

[0130] In another preferred embodiment of the present invention, the embossing liquid in the step (S.5) at least contains an inhibitor for preventing the polymerization of the resin liquid.

[0131] In this preferred embodiment, an inhibitor is added to the embossing liquid, which can quench the free radicals generated by the decomposition of the photoinitiator under light, thereby effectively preventing the polymerization of the resin liquid containing the inhibitor or reducing the curing speed of the resin liquid containing the inhibitor, so that after the step (S.6) is completed, the resin liquid containing the inhibitor can still remain in a liquid or semi-solid state, thereby making the embossing layer easier to remove.

[0132] In another preferred embodiment of the present invention, the resin liquid at least includes a thermosetting resin.

[0133] In another preferred embodiment of the present invention, the thermosetting resin includes one or more combinations of epoxy resin, phenolic resin, melamine formaldehyde resin, furan resin, unsaturated polyester resin, silicone resin, and polybutadiene resin.

[0134] In another preferred embodiment of the present invention, the resin solution further includes a curing agent.

[0135] In another preferred embodiment of the present invention, the step (S.4) further comprises a step for providing kinetic energy for the embossing liquid to penetrate downward into the resin liquid.

[0136] After the embossing liquid is applied to the surface of the uncured resin liquid, it may not be able to quickly penetrate into the interior of the uncured resin liquid, which may lead to insufficient depth of the three-dimensional wood grain in some embodiments. Therefore, in order to make the three-dimensional wood grain have a stronger three-dimensional sense, the applicant proposes to solve this technical problem by increasing the penetration speed of the embossing liquid. The applicant found that after providing kinetic energy to the embossing liquid, it can enter the interior of the uncured resin liquid at a faster speed or kinetic energy, thereby increasing the depth of the three-dimensional wood grain.

[0137] In another preferred embodiment of the present invention, the embossing liquid contains a curable resin.

[0138] The curable resin contained in the embossing liquid includes acrylic resin, epoxy resin or other curable resins.

[0139] In another preferred embodiment of the present invention, the curable resin contained in the embossing liquid has a surface energy lower than the surface energy of the three-dimensional wood grain layer after curing.

[0140] In some preferred embodiments of the present application, the embossing liquid contains a resin having a surface energy lower than that of the three-dimensional wood grain layer, so that the embossing liquid has a weaker adhesion to the three-dimensional wood grain layer after curing, thereby allowing the embossing liquid to be easily removed by mechanical or solvent cleaning steps after curing.

[0141] In another preferred embodiment of the present invention, the curable resin contained in the embossing liquid has a surface energy lower than 100 mN / m after curing.

[0142] In another preferred embodiment of the present invention, the curable resin contained in the embossing liquid includes any one of fluorocarbon resin, fluorosilicone resin or silicone resin.

[0143] In another preferred embodiment of the present invention, the density of the embossing liquid is greater than the density of the resin liquid.

[0144] In addition to actively providing kinetic energy to the embossing liquid as described above, the applicant also proposed that in some preferred embodiments of the present application, the speed at which the embossing liquid penetrates into the uncured resin liquid can be further increased by passively increasing the kinetic energy of the embossing liquid. For example, the density of the embossing liquid can be adjusted so that the density of the embossing liquid is greater than the density of the resin liquid, so that after applying the same volume of embossing liquid to the surface of at least a portion of the uncured resin liquid, the mass of the embossing liquid is higher, so that the kinetic energy is greater when it enters the uncured resin liquid, thereby making the depth of the three-dimensional wood grain layer formed deeper. At the same time, after the high-density embossing liquid enters the resin liquid, it is easier to quickly penetrate into the uncured resin liquid due to its own gravity.

[0145] In another preferred embodiment of the present invention, the embossing liquid further comprises a density regulator for adjusting the density of the embossing liquid.

[0146] In another preferred embodiment of the present invention, the density regulator is an inorganic solid powder additive.

[0147] In another preferred embodiment of the present invention, the density regulator may be an inorganic solid additive, such as calcium carbonate, silicon dioxide, and the like.

[0148] In another preferred embodiment of the present invention, the embossing liquid comprises at least two embossing liquids with different surface tensions.

[0149] As described in the background technology, in order to make the three-dimensional structure feel similar to that of actual wood, in addition to the depth mentioned above, another key point is how to control the width of the three-dimensional structure. As for the width of the three-dimensional structure, its width control is currently mainly based on the amount of embossing liquid sprayed. Generally, the larger the amount of embossing liquid sprayed or the larger the single drop of embossing liquid, the larger the width of the wood grain gap, and the smaller the amount of embossing liquid sprayed or the drop of embossing liquid, the smaller the width of the wood grain gap formed.

[0150] However, the above solution has the following two problems:

[0151] (1) In order to form a wider three-dimensional wood grain, more embossing liquid needs to be added. Since the embossing liquid needs to be removed in the final step, adding more embossing liquid will result in more waste of embossing liquid.

[0152] (2) In order to form a three-dimensional wood grain with a smaller width, a smaller amount of embossing liquid needs to be added, but this will cause the depth of the three-dimensional wood grain to be too small. At the same time, the accuracy of the three-dimensional wood grain may be insufficient, resulting in unnatural defects in the three-dimensional wood grain.

[0153] In view of the above problems, the present application proposes a solution, that is, the embossing liquid used to form the three-dimensional wood grain with a larger width and the embossing liquid used to form the three-dimensional wood grain with a smaller width are selected from materials with different tensions.

[0154] When using embossing liquid with smaller tension, it is easier to spread on the surface of the wear-resistant layer. In this case, the contact angle between the embossing liquid with small tension and the wear-resistant layer is smaller, because it can spread over a larger area under the same volume, which is equivalent to using less embossing liquid to achieve a wider three-dimensional wood grain.

[0155] When using embossing liquid with greater tension, it is not easy to spread on the surface of the wear-resistant layer. In this case, the contact angle between the embossing liquid with greater tension and the wear-resistant layer is greater. Therefore, under the condition of the same volume, the height of the droplets is higher. Therefore, when using a smaller amount of embossing liquid with greater tension, it can obtain finer and deeper three-dimensional wood grain.

[0156] In another preferred embodiment of the present invention, the coverage of the ink on the surface of the plate in step (S.1) is 6-8 g / m 2 .

[0157] In another preferred embodiment of the present invention, the amount of the resin liquid covering the surface of the wood grain bottom layer in step (S.2) is 30-50 g / m 2 .

[0158] In a second aspect, in another preferred embodiment of the present invention, the present invention further provides a board with three-dimensional wood grain, comprising a board;

[0159] The surface of the board includes a wood grain bottom layer and a three-dimensional wood grain layer prepared by the method described above.

[0160] In another preferred embodiment of the present invention, the following are arranged in sequence between the board and the wood grain bottom layer:

[0161] A primer layer used to improve the bonding performance of the board surface;

[0162] A color paint layer disposed on the surface of the primer layer to cover the color of the substrate;

[0163] An ink layer located on the surface of the paint layer to form a wood grain pattern.

[0164] In another preferred embodiment of the present invention, the outer surface of the three-dimensional wood grain layer is further covered with a topcoat layer, and at least a portion of the topcoat layer is lower than the upper surface of the three-dimensional wood grain layer.

[0165] In a third aspect, in another preferred embodiment of the present invention, the present invention further provides a method for preparing the board having three-dimensional wood grain.

[0166] It at least comprises the steps of preparing a wood grain base layer and a three-dimensional wood grain layer according to the method described above.

[0167] In another preferred embodiment of the present invention, the following steps are also included:

[0168] A step of covering at least a portion of the surface of the plate with a primer and curing the primer layer;

[0169] The step of covering at least a portion of the surface of the primer layer with a color paint and curing the primer layer to obtain a color paint layer;

[0170] The step of covering at least a portion of the surface of the color paint layer with ink having a wood grain pattern and curing the ink layer;

[0171] The step of making at least a portion of the surface of the ink layer cover the wood grain base layer and the three-dimensional wood grain layer prepared according to the method described above;

[0172] The step of covering at least a portion of the surface of the three-dimensional wood grain layer with a topcoat and curing the topcoat layer.

[0173] In another preferred embodiment of the present invention,

[0174] The coverage of the primer is 10-15g / m 2 ;

[0175] The coverage of the paint is 15-20g / m 2 ;

[0176] The coverage of the topcoat is 20-30g / m 2 .

[0177] In another preferred embodiment of the present invention, the color paint layer is white.

[0178] In another preferred embodiment of the present invention, the paint contains at least a photo-crosslinking resin, a photoinitiator and white pigment powder.

[0179] In a fourth aspect, the present invention further provides the use of the board with three-dimensional wood grain in floors, decorative wall panels or ceiling panels.

[0180] The following examples are provided only to illustrate the present invention and are not intended to limit the scope of protection defined by the appended claims.

[0181] Example 1

[0182] The method for forming three-dimensional wood grain on the surface of a board comprises the following steps:

[0183] (S.1) Place an SPC sheet with a length, width and thickness of 1260 mm*970 mm*4.85 mm on the surface of a conveying device moving in a fixed direction;

[0184] (S.2) During the conveying process, the SPC sheet first passes through the first roller coater, the coating roller surface of which is adhered with a photocurable primer (the primer contains: 90% photocurable varnish HYS01-1, 5% photoinitiator 184, 0.5% photoinitiator TPO, 4.5% diluent hydroxyethyl acrylate). During the contact between the SPC sheet and the coating roller, 12g / m 2 The primer is applied to the surface of the SPC sheet using 395nm and 8W / cm 2 The primer is cured by a UV lamp to form a primer layer;

[0185] (S.3) The SPC sheet obtained in the previous step is passed through a second roller coater, the coating roller surface of which is adhered with a photocurable white paint (the white paint contains: 50% photocurable epoxy HYS01-1, 30% titanium dioxide, 5% photoinitiator 184, 0.5% photoinitiator TPO, 14.5% diluent hydroxyethyl acrylate). During the contact between the SPC sheet and the coating roller, 18 g / m 2 The white paint is applied on the surface of the primer, and the 2 After curing with UV lamp, a white paint layer is obtained;

[0186] (S.4) The SPC sheet obtained in the previous step is conveyed to the first inkjet printer, so that the surface of the color paint layer is sprayed with 6-8 g / m 2 The ink is solidified to form an ink layer with a wood grain pattern on the surface of the primer layer; (S.5) the SPC sheet obtained in the previous step is conveyed to the third roller coater, and 45g / m2 of ink is roller-coated on the surface of the ink layer. 2 The photocurable resin liquid (the resin liquid contains: 90% Dow Corning 65Additive, 5% photoinitiator 184, 0.5% photoinitiator TPO, 4.5% diluent hydroxyethyl acrylate) was sequentially subjected to 395nm and 8W / cm 2 UV lamp and 160w / cm 2 After being cured by Hg lamp, a wood grain bottom layer is formed;

[0187] (S.6) The SPC sheet obtained in the previous step is conveyed to the fourth roller coater, so that the coating roller of the fourth roller coater is rolled along the conveying direction of the SPC sheet (the roller rotates clockwise) to coat 80g / m 2Resin liquid (the resin liquid contains: 90% Dow Corning 65Additive, 5% photoinitiator 184, 0.5% photoinitiator TPO, 4.5% diluent hydroxyethyl acrylate);

[0188] (S.7) After applying the first layer of resin liquid, the SPC sheet is conveyed forward along the surface of the conveying device, and it is ensured that the fourth roller coater does not apply any force to the resin liquid before conveying to the next roller coater;

[0189] (S.8) The SPC sheet obtained in the previous step is conveyed to the fifth roller coater, so that the coating roller of the fifth roller coater continues to roll-coat 75g / m against the conveying direction of the SPC sheet (the roller itself rotates clockwise). 2 Resin liquid;

[0190] Figure 2 A schematic diagram of step (S.6) to step (S.8) in this embodiment is shown, so that these three steps can be better understood;

[0191] (S.9) The SPC sheet obtained in the previous step is transported to the second inkjet printer so that 6-8 g / m 2 The embossing liquid (the embossing liquid comprises: 45.5% of diacrylate monomer PEG600DA, 20.5% of p-hydroxyanisole HQMME, 10% of 2-tert-butylhydroquinone MTBHQ, and 24% of diethylene glycol butyl ether), and the embossing liquid is allowed to penetrate downward into the resin liquid and mix with the resin liquid to form an embossing layer;

[0192] (S.10) The surface of the SPC sheet obtained in the previous step, except for the embossed layer, was subjected to 395nm and 8W / cm 2 UV lamp and 160w / cm 2 Hg lamp irradiation for deep curing;

[0193] (S.11) conveying the SPC sheet obtained in the previous step to a cleaning device including a steel brush, so that the embossed layer is brushed out by the steel brush, thereby forming a three-dimensional wood grain layer;

[0194] (S.12) The SPC sheet obtained in the previous step was passed through the sixth roller coater and 395nm and 8W / cm 2 UV lamp, thus coating the surface of the three-dimensional wood grain layer with 12g / m 2 A first topcoat is applied and cured to obtain a first topcoat layer;

[0195] (S.13) The SPC sheet obtained in the previous step was passed through the seventh roller coater and 395nm and 8W / cm 2UV lamp, so as to apply 12g / m 2 The second topcoat is applied and cured to obtain a second topcoat layer.

[0196] The plate with a three-dimensional surface structure prepared in Example 1 was analyzed by laser profilometer analysis to obtain Figure 3 as well as Figure 4 ,in: Figure 3 This is a schematic diagram of the three-dimensional structure of three-dimensional wood grain. Figure 4 This is a schematic diagram of the top view structure of three-dimensional wood grain.

[0197] Comparative Example 1

[0198] The steps of Comparative Example 1 are basically the same as those of Example 1, except that step (S.5) is omitted in Comparative Example 1, so the prepared three-dimensional structure does not contain a wood grain bottom layer. Figure 5 and Figure 6 They are respectively a schematic diagram of the three-dimensional structure of the three-dimensional wood grain prepared in comparative example 1 of the present invention and a schematic diagram of the top view of the three-dimensional wood grain. It can be seen from the figure that after omitting step (S.5), the average depth of the wood grain formed is lower.

[0199] Comparative Example 2

[0200] The steps of Comparative Example 2 are substantially the same as those of Example 1, except that, in step (S.5), the resin liquid is not completely cured until it is gelled.

[0201] Comparative Example 3

[0202] The steps of Comparative Example 3 are basically the same as those of Example 1, except that after step (S.8), the resin liquid is irradiated with ultraviolet light, so as to obtain an incompletely cured gel-like resin layer. Figure 7 The three-dimensional structure schematic diagram of the three-dimensional wood grain prepared in comparative example 3 of the present invention. As can be seen from the figure, the three-dimensional wood grain prepared in comparative example 3 has a lower depth and its edge is less clear.

[0203] Product testing:

[0204] Surface wear resistance test: Tested in accordance with standard GT / T 18102-2020.

[0205] Surface scratch resistance index test: Tested in accordance with standard GT / T 18102-2020.

[0206] Clarity test: Tested in accordance with standard JIS K7374.

[0207] Product qualification rate test: 50 plates were produced in batches according to the methods in the above-mentioned embodiment 1, comparative example 1 and comparative example 2, and the plates were observed for cracking and delamination, and the initial warpage and heating warpage of the plates were measured. The product qualification rate was calculated, and the results are shown in Table 1. Plates with quality problems observable by the naked eye and plates with heating warpage greater than 1 mm / m were recorded as unqualified.

[0208] Alignment accuracy test: The alignment accuracy can be observed with the naked eye to see if there is any deviation, ghosting or damage.

[0209] Warp test: Cut the plate into 240mm*240mm specimens, place them on the aluminum plate with the wear-resistant layer facing upwards, and place them at 23±2℃ and 50±5%RH for 24 hours, and measure the average initial warpage of the plate with a caliper; adjust the temperature in the constant temperature drying oven to 80℃, place the specimen together with the aluminum plate in the constant temperature drying oven for 6 hours, then take out the specimen together with the aluminum plate, and place them at 23±2℃ and 50±5%RH for 24 hours, and measure the average heating warpage of the plate with a caliper.

[0210] The test results of the plate properties of Example 1 and Comparative Examples 1 to 3 are shown in Table 1 below:

[0211] Table 1 Performance test results

[0212]

[0213] Example 2

[0214] The steps of Example 2 are basically the same as those of Example 1, except that the covering method of the resin liquid in steps (S.6) to (S.8) is changed. Figure 8 As shown in the present embodiment, in step (S.6) and step (S.8), the resin liquid is sprayed onto the surface of the wood grain bottom layer in a spraying manner. During the spraying process, a certain angle is formed between the nozzle and the SPC board.

[0215] Among them: in step (S.6), the nozzle forms a certain angle with the direction of SPC sheet conveying (in this embodiment, the nozzle and the direction of SPC sheet conveying form an acute angle of 30°). And in step (S.8), the nozzle forms a certain angle along the direction of SPC sheet conveying (in this embodiment, the nozzle and the direction of SPC sheet conveying form an obtuse angle of 150°).

[0216] Example 3

[0217] The steps of Example 3 are basically the same as those of Example 1, except that the composition of the resin liquid and the curing method are changed in steps (S.5) to (S.8).

[0218] The composition of the resin liquid can be selected from a thermosetting resin system, as follows:

[0219]

[0220] After the thermosetting resin system obtained by mixing the above formula is coated on the surface of the SPC board, the ambient temperature of the SPC board is raised to 140° C. by infrared heating, so that the thermosetting resin system can be cured.

[0221] The test results of the plate performance of Example 3 are shown in Table 2 below:

[0222] Table 2 Performance test results

[0223]

[0224] Example 4

[0225] The steps of Example 4 are basically the same as those of Example 1, except that the composition of the embossing liquid in step (S.9) is changed.

[0226] In this embodiment, the embossing liquid is a polytetrafluoroethylene emulsion with a solid content of 60%. After the polytetrafluoroethylene emulsion is coated on the resin liquid, it penetrates downward into the interior of the resin liquid. Since the polytetrafluoroethylene emulsion is aqueous, it will not be miscible with the resin liquid after penetrating into the resin liquid. Therefore, after the resin liquid is solidified, a part of the water in the polytetrafluoroethylene emulsion evaporates due to heat, thereby forming a polytetrafluoroethylene layer. Since the surface energy of the polytetrafluoroethylene layer is lower than 100mN / m, it will not adhere to the solidified resin liquid, so it is better to remove.

[0227] Example 5

[0228] The steps of Example 5 are basically the same as those of Example 4, except that when the embossing liquid (polytetrafluoroethylene emulsion with a solid content of 60%) is applied to the resin liquid, the speed of injecting the embossing liquid into the resin liquid is increased to 5 m / s.

[0229] The specific impacts are shown in Table 3 below:

[0230] Table 3

[0231] project Example 4 Example 5 Embossing liquid injection speed 3m / s 5m / s Maximum groove depth 69μm 81μm .

[0232] It can be seen from Table 1 above that after increasing the embossing liquid injection speed, the depth of the three-dimensional structure on the surface of the sheet material finally formed is significantly improved, with the maximum depth increasing by 17.4%.

[0233] Example 6

[0234] The steps of Example 6 are basically the same as those of Example 4, except that nano-silicon dioxide is added to the embossing liquid (polytetrafluoroethylene emulsion with a solid content of 60%), so that the density of the embossing liquid is increased from 1.5 g / cm 3 Increased to 2.0g / cm 3 .

[0235] The specific impacts are shown in Table 4 below:

[0236] Table 4

[0237] project Example 4 Example 6 Embossing liquid density <![CDATA[1.5g / cm 3 ]]> <![CDATA[2.0g / cm 3 ]]> Maximum groove depth 69μm 88μm .

[0238] It can be seen from Table 3 above that after increasing the density of the embossing liquid, the depth of the three-dimensional structure of the surface of the sheet material finally formed is significantly increased, with the maximum depth increased by 27.5%.

[0239] Comparative Example 4

[0240] The steps of Comparative Example 4 are basically the same as those of Example 1, except that steps (6) to (8) are combined and coated using a conventional double-roller coater.

[0241] The schematic diagram of its structure during roller coating is as follows: Figure 8 As shown, when the SPC board covered with the wood grain bottom layer is conveyed to the bottom of the double-roller coater along the conveying mechanism, the board first coats a layer of resin liquid on the surface of the wood grain bottom layer to form resin liquid 1 when passing through the first roller of the double-roller coater, and then when the surface of the wood grain bottom layer is not completely covered by the resin liquid 1, the SPC board immediately passes through the second roller of the double-roller coater again, thereby continuing to coat a layer of resin liquid on the surface of the resin liquid 1 to form resin liquid 2, until the resin liquid 1 and the resin liquid 2 completely cover the surface of the wood grain bottom layer.

[0242] Figure 2 This is an image of a plate having a three-dimensional structure on its surface prepared by the method in Comparative Example 4. It can be seen from the figure that the plate prepared by the method in Comparative Example 4 has obvious marks on its surface.

[0243] The test results of the plate performance of Comparative Example 4 are shown in Table 5 below:

[0244] Table 5 Performance test results

[0245]

Claims

1. A method for forming three-dimensional wood grain on a board surface, characterized in that: At least the following steps are included: (S.1) a step of covering at least a portion of the surface of the plate with ink, thereby forming an ink layer having a wood grain pattern; (S.2) a step of covering at least a portion of the surface of the ink layer with a resin liquid; (S.3) a step of solidifying at least a portion of the resin liquid on the surface of the ink layer to form a wood grain bottom layer; (S.4) a step of covering at least a portion of the surface of the wood grain bottom layer with at least one layer of resin liquid; (S.5) applying embossing liquid to at least a portion of the surface of the resin liquid on the wood grain bottom layer along the wood grain pattern of the ink layer, so that the embossing liquid and / or at least a portion of the resin liquid mixed with the embossing liquid and / or at least a portion of the resin liquid covered by the embossing liquid forms an embossing layer; (S.6) a step of solidifying the resin liquid except for the embossed layer formed in the previous step; (S.7) A step of removing the embossed layer to form a three-dimensional wood grain layer on the surface of the wood grain base layer.

2. The method according to claim 1, characterized in that The amount of the resin liquid covering the surface of the wood grain bottom layer in the step (S.4) is greater than or equal to 150 g / m 2 .

3. The method according to claim 2, characterized in that In the step (S.4), at least a portion of the surface of the wood grain bottom layer is covered with at least two layers of resin liquid.

4. The method according to claim 3, characterized in that: In the process of covering at least a portion of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid, it also includes a transition treatment step of stopping the application of force to the resin liquid after the wood grain bottom layer is covered by any layer of resin liquid, and covering with the next layer of resin liquid after the transition treatment step is completed.

5. The method according to claim 3 or 4, characterized in that: In the process of covering at least a part of the surface of the wood grain bottom layer with any two adjacent layers of resin liquid, the directions of the forces applied to the any two adjacent layers of resin liquid are opposite.

6. The method according to claim 1, characterized in that The plate completes steps (S.1) to (S.6) in sequence while being transported along a fixed direction.

7. The method according to claim 1, characterized in that In the step (S.5), the embossing liquid is applied to the surface of the resin liquid and / or penetrates downward into the interior of the resin liquid.

8. The method according to claim 1 or 7, characterized in that: The curing method of the resin liquid covered in the steps (S.2) and (S.4) includes any one of light curing, thermal curing or electron beam curing.

9. The method according to claim 8, characterized in that The resin solution at least includes a photo-crosslinking resin and a photoinitiator.

10. The method according to claim 9, characterized in that The embossing liquid in the step (S.4) at least contains a polymerization inhibitor for preventing the polymerization of the photo-crosslinking resin.

11. The method according to claim 9, characterized in that The photo-crosslinking resin includes any one or more combinations of unsaturated polyester, epoxy resin, acrylic resin, acrylic modified polyurethane resin, acrylic modified silicone resin, acrylic modified epoxy resin, water-based epoxy acrylate, water-based polyurethane acrylate, and water-based polyester acrylate.

12. The method according to claim 9, characterized in that The photoinitiator includes any one of a free radical polymerization initiator, a cationic polymerization initiator, an energy transfer initiator, and an ion reaction initiator.

13. The method according to claim 8, characterized in that The resin liquid at least includes a thermosetting resin.

14. The method according to claim 13, characterized in that The thermosetting resin includes one or more of epoxy resin, phenolic resin, melamine formaldehyde resin, furan resin, unsaturated polyester resin, silicone resin, and polybutadiene resin.

15. The method according to claim 13, characterized in that The resin solution also includes a curing agent for catalyzing the curing of the thermosetting resin.

16. The method according to claim 7, characterized in that The step (S.4) also includes a step for providing kinetic energy for the embossing liquid to penetrate downward into the resin liquid.

17. The method according to claim 16, characterized in that The embossing liquid contains a curable resin.

18. The method according to claim 17, characterized in that The curable resin contained in the embossing liquid has a surface energy lower than the surface energy of the three-dimensional wood grain layer after curing.

19. The method according to claim 18, characterized in that The curable resin contained in the embossing liquid has a surface energy lower than 100 mN / m after curing.

20. The method according to any one of claims 17 to 19, characterized in that: The curable resin contained in the embossing liquid includes any one of fluorocarbon resin, fluorosilicone resin or organic silicone resin.

21. The method according to any one of claims 1 or 7 or 16 to 19, characterized in that: The density of the embossing liquid is greater than the density of the resin liquid.

22. The method according to claim 21, characterized in that The embossing liquid also includes a density regulator for adjusting the density of the embossing liquid.

23. The method according to claim 22, characterized in that The density regulator is an inorganic solid powder additive.

24. The method according to any one of claims 1 or 7 or 16 to 19, characterized in that: The embossing liquid comprises at least two embossing liquids with different surface tensions.

25. The method according to claim 1, characterized in that The coverage of the ink on the surface of the plate in step (S.1) is 6-8 g / m 2 .

26. The method according to claim 1, characterized in that The amount of the resin solution in step (S.2) is 30 to 50 g / m 2 .

27. A board with three-dimensional wood grain, characterized in that: Including plates; The surface of the board comprises a wood grain base layer and a three-dimensional wood grain layer prepared by the method according to any one of claims 1 to 26.

28. The board with three-dimensional wood grain according to claim 27, characterized in that: The following are arranged in sequence between the board and the wood grain bottom layer: A primer layer used to improve the bonding performance of the board surface; A color paint layer provided on the surface of the primer layer to cover the color of the substrate; An ink layer located on the surface of the paint layer to form a wood grain pattern.

29. The board with three-dimensional wood grain according to claim 27 or 28, characterized in that: The outer surface of the three-dimensional wood grain layer is also covered with a topcoat layer, and at least a portion of the topcoat layer is lower than the upper surface of the three-dimensional wood grain layer.

30. A method for preparing a board having three-dimensional wood grain as claimed in any one of claims 27 to 29, characterized in that: The method at least comprises the steps of preparing a wood grain base layer and a three-dimensional wood grain layer according to the method as claimed in any one of claims 1 to 26.

31. The method for preparing a board with three-dimensional wood grain according to claim 30, characterized in that: The following steps are involved: A step of covering at least a portion of the surface of the plate with a primer and curing the primer layer; The step of covering at least a portion of the surface of the primer layer with a color paint and curing the primer layer to obtain a color paint layer; The step of making at least a portion of the surface of the color paint layer covered with an ink layer, a wood grain base layer and a three-dimensional wood grain layer prepared by the method according to any one of claims 1 to 26; The step of covering at least a portion of the surface of the three-dimensional wood grain layer with a topcoat and curing the topcoat layer.

32. The method for preparing a board with three-dimensional wood grain according to claim 31, characterized in that: The coverage of the primer is 10-15g / m 2 ; The coverage of the paint is 15-20g / m 2 ; The coverage of the topcoat is 20-30g / m 2 .

33. The method for preparing a board with three-dimensional wood grain according to claim 31 or 32, characterized in that: The color paint layer is white.

34. The method for preparing a board having three-dimensional wood grain according to claim 33, characterized in that: The color paint at least contains a photo-crosslinking resin, a photoinitiator and white pigment powder.

35. Use of the board with three-dimensional wood grain as claimed in any one of claims 27 to 29 in flooring, decorative wall panels or ceiling panels.

Images