Coated fabric having wetting effect of xuan paper
Patent Information
- Application Number
- PCT/CN2026/089497
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-26
- Filing Date
- 2026-04-09
- Publication Date
- 2026-09-03
Smart Images
Figure CN2026089497_03092026_PF_FP_ABST
Abstract
Description
Coated cloth with the effect of wetting Xuan paper Technical Field
[0001] This invention relates to the field of canvas technology, and in particular to a coated cloth with the wetting effect of Xuan paper. Background Technology
[0002] Painting on canvas is typically used only in Western oil painting, while Chinese ink painting generally requires Xuan paper. However, the traditional production process of Xuan paper has very high requirements for the process environment, climate, temperature, and the skills of the operators, making it difficult to maintain a consistent output of Xuan paper. Furthermore, high-quality Xuan paper has a high market price, resulting in high purchase and usage costs for ordinary painters.
[0003] The applicant has previously filed several patents for canvases with a Xuan paper-like effect, such as: patent publication number CN117738024A, which discloses a Xuan paper-like coating and Xuan paper, its preparation method and application; patent application publication number CN115341381A, which discloses a method for preparing a Xuan paper-like ink-absorbing hand-painted canvas; and patent announcement number CN103741481B, which discloses an ink-absorbing, self-drying canvas. However, domestic research and development in this area is limited and still faces some challenges. For example, the method of applying a coating to the fabric surface using a combination of fillers (cellulose fibers, nano-calcium carbonate, etc.) and sizing agents (starch, modified starch, etc.) still has room for improvement in terms of bonding strength between the sizing agent and polyester when combined with polyester or other synthetic fiber substrates. Summary of the Invention
[0004] The technical problem to be solved by the embodiments of the present invention is to provide a coated cloth with a Xuan paper wetting effect, thereby solving the problem of weak bonding between the coated cloth with the Xuan paper wetting effect made of polyester plain weave fabric as the substrate and the pulp.
[0005] To solve the above-mentioned technical problems, the present invention provides a coated fabric with the wetting effect of Xuan paper, comprising a polyester plain weave fabric base layer, an esterification layer, and a coating slurry layer. The esterification layer is tightly bonded to the upper surface of the polyester plain weave fabric base layer and the gaps between the polyester warp and weft threads. The coating slurry layer is integrally formed with the esterification layer. The main components of the coating slurry layer are oxidized starch and carboxylated nanocellulose, wherein the oxidized starch and carboxylated nanocellulose are mixed in a weight ratio of (3-20):1, and the hydroxyl functional group content of the oxidized starch in the coating slurry layer is greater than the carboxyl functional group content of the carboxylated nanocellulose. The esterification layer is formed by an esterification reaction between the excess hydroxyl functional groups of the oxidized starch and citric acid impregnated on the surface of the polyester plain weave fabric base layer.
[0006] The thickness of the polyester plain weave fabric base layer is 0.3-0.6 mm; the average thickness of the slurry layer is between 0.1-0.2 mm; the thickness of the esterification layer on the upper surface of the polyester plain weave fabric base layer is between 0.02-0.05 mm, and the depth to which the esterification layer sinks into the gaps between the polyester warp and weft threads is between 0.2-0.4 mm; wherein, the esterification layer is formed by first impregnating the polyester plain weave fabric base layer with a citric acid solution, and then using wind power to make the slurry coated on the polyester plain weave fabric base layer penetrate into the gaps between the warp and weft threads of the polyester plain weave fabric base layer, and heating to cause an esterification reaction between the oxidized starch and citric acid in the slurry.
[0007] The citric acid is obtained by immersing the polyester plain weave fabric base layer in a citric acid solution before applying the sizing agent, or by spraying it onto the upper surface of the polyester plain weave fabric base layer. The citric acid content in the citric acid solution is 3-5 wt%.
[0008] Before applying the slurry, hot air needs to be blown onto the lower surface of the polyester plain weave fabric base layer to evaporate the water in the citric acid solution and retain the citric acid on the upper surface of the polyester plain weave fabric base layer and in the gaps between the polyester warp and weft threads.
[0009] The temperature of the hot air is between 60-75℃ to avoid decomposing the citric acid.
[0010] In the coating slurry, the weight of oxidized starch and carboxylated nanocellulose does not exceed 10% of the total weight.
[0011] The coating slurry also contains 0.5 wt% water-based polyurethane thickener, 0.02 wt% isothiazolinone preservative, 0.2 wt% leveling agent, 0.15 wt% dispersant and 0.15 wt% defoamer.
[0012] The preparation process of the coating slurry includes:
[0013] Prepare an oxidized starch solution and gelatinize the oxidized starch solution;
[0014] Preparation of carboxylated cellulose nanoparticle dispersion;
[0015] The gelatinized oxidized starch solution and the carboxylated nanocellulose dispersion were mixed at a mass ratio of 2:8 and then mixed evenly by magnetic stirring.
[0016] The carboxylated nanocellulose was prepared by Acetobacter xylinum and then subjected to a carboxylation reaction.
[0017] The process for obtaining the carboxylated nanocellulose includes:
[0018] (a) Acetobacter xylinum generates nanocellulose through biosynthesis;
[0019] 1. Cultivation conditions
[0020] Culture medium: Commonly used HS medium (containing glucose, yeast extract, peptone, phosphate, etc.) provides carbon and nitrogen sources.
[0021] Cultivation method: Promote bacterial dispersion by stirring or airlift reactor to generate granular cellulose.
[0022] Culture period: usually 5-7 days, temperature 28-30°C, pH 4.5-6.0.
[0023] 2. Synthesis mechanism of nanocellulose
[0024] Acetobacter xylinum polymerizes glucose into β-1,4-glucan chains via a cellulose synthase complex on its cell membrane.
[0025] Multiple dextran chains self-assemble into nanofibers (3-50 nm in diameter) through hydrogen bonds, forming a three-dimensional network structure.
[0026] 3. Post-processing
[0027] Purification: Removal of bacterial cells and culture medium residues; common steps include:
[0028] Alkali treatment (0.1-1 M NaOH, 80°C, 1-2 hours) dissolves bacterial proteins.
[0029] Wash repeatedly with water until neutral.
[0030] Disperse nanofibers by mechanical homogenization or ultrasonic treatment.
[0031] (ii) Carboxylation reaction of nanocellulose: chemical grafting;
[0032] The chemical grafting includes introducing a carboxylic acid group (such as by reacting with maleic anhydride) through esterification or etherification reactions.
[0033] The carboxylated nanocellulose has an aspect ratio between 25 and 100, with a diameter of 10-20 nm and a length of 0.5 to 1 μm.
[0034] After the slurry is applied to the upper surface of the polyester plain weave fabric base, hot air at a temperature of 60-75℃ is blown vertically onto the slurry on the polyester plain weave fabric base. Under the pressure of the hot air, part of the slurry enters the gaps between the warp and weft threads of the polyester plain weave fabric base.
[0035] After the sizing agent is dried and the esterification reaction between the excess hydroxyl groups in the sizing agent and the carboxyl groups of citric acid is complete, forming an esterified layer, hot air at a temperature of 78-90°C is blown upward from the lower surface of the polyester plain weave fabric base layer to decompose the hydrate of the remaining citric acid into anhydrous hydrate.
[0036] The coated fabric with the wetting effect of Xuan paper provided by the present invention uses citric acid as a medium to react with the excess hydroxyl groups in the coating slurry to form an esterification layer, thereby improving the bonding force between the coating slurry and the polyester plain weave fabric base layer; and the anhydrous citric acid can also absorb water to form hydrates, thereby improving the wetting effect of the coated fabric. Attached Figure Description
[0037] Figure 1 is a schematic diagram of the planar structure of polyester plain weave fabric base layer (the size ratio of the gaps and warp and weft threads shown in the figure is not the actual ratio; the actual gaps are very small, and the gaps are enlarged for illustration).
[0038] Figure 2 is a schematic diagram of the cross-sectional structure of the polyester plain weave fabric base layer.
[0039] Figure 3 is a schematic diagram of the layered structure of the coated cloth that has the effect of wetting Xuan paper.
[0040] Figure 4 is a schematic diagram of the layered structure of the coated cloth with the effect of wetting Xuan paper (the cut position is different from that in Figure 3).
[0041] Figure 5 shows an electron microscope image of the coated cloth with the effect of wetting Xuan paper (lined carboxylated cellulose nanofibers can be seen randomly distributed in the image).
[0042] Figure 6 shows an electron microscope image of the green pigment impregnated on a coated cloth with a Xuan paper wetting effect.
[0043] Figure 7 shows an electron microscope image of a coated cloth with a Xuan paper wetting effect, impregnated with red pigment.
[0044] Figure 8 shows an electron microscope image of a coated cloth with a Xuan paper wetting effect, impregnated with black pigment.
[0045] Figure 9 shows an electron microscope image of the red stripe wetting effect of the coated cloth with the effect of Xuan paper wetting.
[0046] In the diagram: 1-Polyester plain weave fabric base layer, 2-Esterification layer, 3-Coated slurry layer; 11-Warp, 12-Weft, 13-Gap. Detailed Implementation
[0047] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0048] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.
[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0050] Referring to Figures 1-9, the present invention provides a coated fabric with a Xuan paper wetting effect, comprising a polyester plain weave fabric base layer 1, an esterification layer 2, and a scraping slurry layer 3. The esterification layer 2 is tightly bonded to the upper surface of the polyester plain weave fabric base layer 1 and in the gaps 13 of the polyester warp and weft threads. The scraping slurry layer 3 is integrally formed with the esterification layer 2. The main components of the scraping slurry layer 3 are oxidized starch and carboxylated nanocellulose, wherein the oxidized starch and carboxylated nanocellulose are mixed in a weight ratio of (3-20):1, and the scraping slurry layer is applied... The hydroxyl functional group content of oxidized starch in the slurry layer is greater than the carboxyl functional group content of carboxylated nanocellulose. The esterification layer 2 is formed by the esterification reaction between the excess hydroxyl functional groups of oxidized starch and citric acid impregnated on the surface of polyester plain weave fabric base layer 1. In other words, the esterification layer 2 is formed after the slurry layer 3 is applied to the polyester plain weave fabric base layer, where the oxidized starch in the slurry comes into contact with the polyester plain weave fabric base layer 1, and then undergoes an esterification reaction with the citric acid attached to the polyester plain weave fabric base layer at a suitable temperature (e.g., around 60°C). The citric acid is obtained by immersing the polyester plain weave fabric base layer 1 in a citric acid solution, allowing the citric acid solution to adhere to the polyester plain weave fabric base layer. Afterward, the citric acid solution on the polyester plain weave fabric base layer can be dried at a certain temperature, such as using hot air below 60°C, to ensure that the citric acid does not decompose, thereby increasing the concentration of the residual citric acid solution to facilitate contact and reaction with the slurry.
[0051] The thickness of the polyester plain weave fabric base layer is 0.3-0.6 mm; the average thickness of the sizing agent layer is between 0.1-0.2 mm, and the maximum thickness of the sizing agent layer can reach 0.3 mm; the thickness of the esterification layer on the upper surface of the polyester plain weave fabric base layer is between 0.02-0.05 mm, and the depth to which the esterification layer sinks into the gaps between the polyester warp and weft threads is between 0.2-0.4 mm. This sinking depth is very important, as it can significantly increase the bonding force between the polyester plain weave fabric base layer 1 and the sizing agent. The esterification layer is formed by first impregnating the polyester plain weave fabric base layer with a citric acid solution, then using wind power to allow the sizing agent coated on the polyester plain weave fabric base layer to penetrate into the gaps between the warp and weft threads of the polyester plain weave fabric base layer, and heating to cause an esterification reaction between the oxidized starch and citric acid in the sizing agent.
[0052] The citric acid is obtained by immersing the polyester plain weave fabric base layer in a citric acid solution before applying the sizing agent, or by spraying it onto the upper surface of the polyester plain weave fabric base layer. The citric acid content in the citric acid solution is 3-5 wt%.
[0053] Before applying the sizing agent, hot air needs to be blown onto the lower surface of the polyester plain weave fabric base layer 1 to evaporate the water in the citric acid solution and retain the citric acid on the upper surface of the polyester plain weave fabric base layer and in the gaps between the polyester warp and weft threads. Blowing hot air onto the lower surface of the polyester plain weave fabric base layer 1 also helps to move more of the citric acid solution from bottom to top, allowing it to move towards the upper surface of the polyester plain weave fabric base layer 1. Since the upper surface of the polyester plain weave fabric base layer acts as the sizing application surface, it comes into contact with the sizing agent, allowing the citric acid to fully contact and react with the sizing agent, resulting in better adhesion.
[0054] The temperature of the hot air should be between 60-75℃ to avoid decomposing the citric acid. Since the hydrate in the citric acid solution will begin to decompose when the temperature exceeds 78℃, it is necessary to prevent the citric acid hydrate from decomposing into anhydrous hydrate when heating and evaporating the citric acid.
[0055] In the coating slurry, the weight of oxidized starch and carboxylated nanocellulose does not exceed 10% of the total weight, and is preferably 1%-1.5%.
[0056] The coating slurry also contains 0.5 wt% waterborne polyurethane thickener, 0.02 wt% isothiazolinone preservative, 0.2 wt% leveling agent, 0.15 wt% dispersant, and 0.15 wt% defoamer. These additives can be added during the mixing process of oxidized starch gelatinized with carboxylated nanocellulose dispersion, and the mixture should be thoroughly stirred. Specifically, nano-starch is modified to obtain oxidized starch, then the oxidized starch is mixed with pure water and stirred evenly, and then heated to 62-68℃ to gelatinize the oxidized starch.
[0057] To prepare a dispersion of carboxylated nanocellulose, specifically, carboxylated nanocellulose is mixed with pure water and then stirred until homogeneous to form a dispersion.
[0058] The gelatinized oxidized starch solution and carboxylated nanocellulose dispersion were mixed at a mass ratio of 2:8. Then, thickeners, preservatives, leveling agents, dispersants, defoamers and other additives were added, and the mixture was stirred evenly with magnetic stirring.
[0059] The carboxylated nanocellulose was prepared by Acetobacter xylinum and then subjected to a carboxylation reaction, with a surface carboxyl content of 1.5-2.5 mmol / g.
[0060] The process for obtaining the carboxylated nanocellulose includes:
[0061] (a) Acetobacter xylinum generates nanocellulose through biosynthesis;
[0062] 1. Cultivation conditions
[0063] Culture medium: Commonly used HS medium (containing glucose, yeast extract, peptone, phosphate, etc.) provides carbon and nitrogen sources.
[0064] Cultivation method: Promote bacterial dispersion by stirring or airlift reactor to generate granular cellulose.
[0065] Culture period: usually 5-7 days, temperature 28-30℃, pH 4.5-6.0.
[0066] 2. Synthesis mechanism of nanocellulose
[0067] Acetobacter xylinum polymerizes glucose into β-1,4-glucan chains via a cellulose synthase complex on its cell membrane.
[0068] Multiple dextran chains self-assemble into nanofibers (3-50 nm in diameter) through hydrogen bonds, forming a three-dimensional network structure.
[0069] 3. Post-processing
[0070] Purification: Removal of bacterial cells and culture medium residues; common steps include:
[0071] Alkali treatment (0.1-1 M NaOH, 80℃, 1-2 hours) dissolves bacterial proteins.
[0072] Wash repeatedly with water until neutral.
[0073] Disperse nanofibers by mechanical homogenization or ultrasonic treatment.
[0074] (ii) Carboxylation reaction of nanocellulose: chemical grafting;
[0075] The chemical grafting includes introducing a carboxylic acid group (such as by reacting with maleic anhydride) through esterification or etherification reactions.
[0076] The carboxylated nanocellulose has an aspect ratio between 25 and 100, with a diameter of 10-20 nm and a length of 0.5 to 1 μm.
[0077] After the slurry is applied to the upper surface of the polyester plain weave fabric base, hot air at a temperature of 60-75℃ is blown vertically onto the slurry on the polyester plain weave fabric base. Under the pressure of the hot air, part of the slurry enters the gaps between the warp and weft threads of the polyester plain weave fabric base.
[0078] After the sizing agent is dried and the esterification reaction between the excess hydroxyl groups in the sizing agent and the carboxyl groups of citric acid is complete, forming an esterified layer, hot air at a temperature of 78-90℃ is blown upwards from the lower surface of the polyester plain weave fabric base layer. This causes the remaining citric acid hydrate to decompose into anhydrous hydrate. Citric acid decomposes into water vapor and carbon dioxide at temperatures above 90℃. Citric acid is slightly hygroscopic in humid air and can exist in anhydrous or monohydrate form. Heating to 78℃ decomposes it into anhydrous hydrate. Therefore, controlling the hot air temperature above 78℃ but not exceeding 90℃ promotes the decomposition of citric acid into anhydrous hydrate while preventing further decomposition into water vapor and carbon dioxide at excessively high temperatures. By retaining the effective components of citric acid and allowing it to exist in anhydrous form, it can absorb moisture after the coated fabric is formed, resulting in better wetting of the coated fabric.
[0079] The coated fabric with the wetting effect of Xuan paper provided by the present invention uses citric acid as a medium to react with the excess hydroxyl groups in the coating slurry to form an esterification layer, thereby improving the bonding force between the coating slurry and the polyester plain weave fabric base layer; and the anhydrous citric acid can also absorb water to form hydrates, thereby improving the wetting effect of the coated fabric.
[0080] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0081] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A coated cloth with the wetting effect of Xuan paper, characterized in that, The material comprises a polyester plain weave fabric base layer, an esterification layer, and a coating slurry layer. The esterification layer is tightly bonded to the upper surface of the polyester plain weave fabric base layer and the gaps between the polyester warp and weft threads. The coating slurry layer is integrally formed with the esterification layer. The main components of the coating slurry layer are oxidized starch and carboxylated nanocellulose, which are mixed in a weight ratio of (3-20):
1. The hydroxyl functional group content of the oxidized starch in the coating slurry layer is greater than the carboxyl functional group content of the carboxylated nanocellulose. The esterification layer is formed by an esterification reaction between the excess hydroxyl functional groups of the oxidized starch and citric acid impregnated on the surface of the polyester plain weave fabric base layer. The formation of the esterification layer involves first impregnating or spraying the polyester plain weave fabric base layer with a citric acid solution, then using wind power to allow the slurry coated on the polyester plain weave fabric base layer to penetrate into the gaps between the warp and weft threads of the polyester plain weave fabric base layer, and heating to cause an esterification reaction between the oxidized starch and citric acid in the slurry. Before applying the slurry, hot air needs to be blown onto the lower surface of the polyester plain weave fabric base to evaporate the water in the citric acid solution and retain the citric acid on the upper surface of the polyester plain weave fabric base and in the gaps between the polyester warp and weft threads. After the slurry is applied to the upper surface of the polyester plain weave fabric base, hot air at a temperature of 60-75℃ is blown vertically onto the slurry on the polyester plain weave fabric base. Under the pressure of the hot air, part of the slurry enters into the gaps between the warp and weft threads of the polyester plain weave fabric base. After the sizing agent is dried and the esterification reaction between the excess hydroxyl groups in the sizing agent and the carboxyl groups of citric acid is complete, forming an esterified layer, hot air at a temperature of 78-90°C is blown upward from the lower surface of the polyester plain weave fabric base layer to decompose the hydrate of the remaining citric acid and obtain anhydrous hydrate.
2. The coated fabric according to claim 1, characterized in that, The thickness of the polyester plain weave fabric base layer is 0.3-0.6 mm; the average thickness of the coating slurry layer is between 0.1-0.2 mm; the thickness of the esterification layer on the upper surface of the polyester plain weave fabric base layer is between 0.02-0.05 mm, and the depth to which the esterification layer sinks into the gap between the polyester warp and weft threads is between 0.2-0.4 mm.
3. The coated fabric according to claim 1, characterized in that, The citric acid is obtained by immersing the polyester plain weave fabric base layer in a citric acid solution before applying the slurry, or by spraying it onto the upper surface of the polyester plain weave fabric base layer; the citric acid content in the citric acid solution is 3-5 wt%.
4. The coated fabric according to claim 1, characterized in that, In the coating slurry, the weight of oxidized starch and carboxylated nanocellulose does not exceed 10% of the total weight.
5. The coated fabric according to claim 4, characterized in that, The coating slurry also contains 0.5 wt% water-based polyurethane thickener, 0.02 wt% isothiazolinone preservative, 0.2 wt% leveling agent, 0.15 wt% dispersant and 0.15 wt% defoamer.
6. The coated fabric according to claim 1, characterized in that, The preparation process of the coating slurry includes: Prepare an oxidized starch solution and gelatinize the oxidized starch solution; Preparation of carboxylated cellulose nanoparticle dispersion; The gelatinized oxidized starch solution and the carboxylated nanocellulose dispersion were mixed at a mass ratio of 2:8 and then mixed evenly by magnetic stirring.
7. The coated fabric according to claim 6, characterized in that, The carboxylated nanocellulose was prepared by Acetobacter xylinum and then subjected to a carboxylation reaction.
8. The coated fabric according to claim 6, characterized in that, The carboxylated nanocellulose has an aspect ratio between 25 and 100, with a diameter of 10-20 nm and a length of 0.5 to 1 μm.