Preparation method of high-color-fastness woven body paper and high-color-fastness woven body paper

Abstract

The invention discloses a preparation method of high-color-fastness woven body paper and the high-color-fastness woven body paper, and relates to the technical field of papermaking, and the preparation method of the high-color-fastness woven body paper comprises the steps of preparing a composite dyeing assistant and preparing the woven body paper. The preparation method comprises the following steps: stirring and mixing cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine myriceate, glucan hydroxypropyl trimethyl ammonium chloride, a water-based polycarbodiimide cross-linking agent and deionized water to obtain a composite dyeing assistant, then adding the composite dyeing assistant into slurry, adding a water-based dye, and carrying out a papermaking process to obtain the composite dyeing assistant. According to the method, the color fastness of the woven body paper can be improved. The sun-proof grade of the high-color-fastness woven body paper is greater than or equal to 4 grades.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of papermaking, and more particularly, to a preparation method of high color fastness woven base paper and high color fastness woven base paper. BACKGROUND

[0002] In recent years, woven base paper has developed rapidly in the textile and clothing industry and woven handicraft field due to its wide source, rich variety, no chemical pollution in the processing process, and the dual advantages of resource and environmental protection that it can be recycled for production and naturally biodegraded after use.

[0003] High-end clothing and textile woven base paper has strict requirements on color fastness index, and usually requires a ≥3 level of sun resistance (the detection method uses ISO 105B02-2014 method). However, in the traditional papermaking process, water-based polyurethane high molecular compounds are often used as fixing agents to improve the binding force between fibers and dye particles. However, this method has many disadvantages, such as the color of dyed paper is not bright enough, the color fastness is not enough, and it is difficult to meet the requirements of high-end products for color performance. More importantly, after washing and sun exposure, the paper is prone to discoloration, which seriously affects the appearance and quality of the product, and cannot meet the needs of modern high-end clothing for color durability.

[0004] Prior art 1 (publication number CN104372709A, publication date: November 28, 2014) discloses a preparation method of firecracker paper, which adds a dyeing aid, a bulking agent and a flame retardant to the firecracker paper pulp, and adjusts the ratio of raw material waste pulp and bamboo pulp, the control of grinding pulp, the adjustment of the pressure of the press roll in the pressing stage, and the drying method of the drying cylinder. Compared with the traditional mechanical method of producing firecracker paper, the tightness of the prepared firecracker paper is reduced by 15%, the tensile strength is increased by 20%, and the redness measured by a color difference meter is increased by more than 30%. However, this invention only improves the redness and does not solve the problem of color durability.

[0005] Therefore, it is urgent to provide a preparation method of high color fastness woven base paper to improve the color fastness of woven base paper. SUMMARY

[0006] Therefore, the present application provides a preparation method of high color fastness woven base paper and high color fastness woven base paper to improve the color fastness of woven base paper.

[0007] In one aspect, the present application provides a preparation method of high color fastness woven base paper, comprising the steps of:

[0008] The steps for preparing the composite dyeing aid include: stirring cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine myricetate, and deionized water; adding dextran hydroxypropyltrimethylammonium chloride while stirring; and then adding an aqueous polycarbodiimide crosslinking agent dropwise while stirring. After the addition is complete, the mixture is stirred and reacted for 25 to 30 minutes to obtain a composite dyeing aid based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine myricetate / dextran hydroxypropyltrimethylammonium chloride / aqueous polycarbodiimide crosslinking agent. The ratio of the amounts of cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine myricetate, dextran hydroxypropyltrimethylammonium chloride, and aqueous polycarbodiimide crosslinking agent is (0.1g-0.2g):(40g-50g):(1g-2g):(5g-10g):(0.01g-0.02g).

[0009] The steps for preparing woven base paper include: by weight, 1000 parts of bleached softwood pulp are put into a pulper and broken down into a pulp with a concentration of 3wt% to 5wt%. Then, the pulp is beaten by a double-disc mill. The pulp obtained after beating is pumped to a mixing tank. Then, 1 to 2 parts of the composite dyeing agent are added while stirring. Then, water-based dye is added while stirring. The pulp is mixed evenly and then passed through the wire section dewatering, forming, pressing, drying and winding processes to obtain blue woven base paper. The water-based dye is turquoise water-based dye, and the amount of water-based dye added is 1‰ to 1.5‰ of the total dry pulp mass.

[0010] Optionally, the cationic microcrystalline cellulose has a length of 20 μm to 200 μm and a width of 0.05 μm to 5 μm.

[0011] Optionally, in the step of preparing the woven base paper, the freeness of the pulp after beating is 30°SR to 40°SR.

[0012] Optionally, in the step of preparing the woven base paper, the wire mesh concentration is 0.5% to 1.0%; the dryness of the wire exit section is 24% to 26%; the dryness of the press section is greater than or equal to 40%; and the drying temperature is 130°C to 135°C.

[0013] Optionally, in the step of preparing the woven base paper, the paper basis weight is 12 g / m². 2 Up to 20g / m 2 .

[0014] On the other hand, the present invention also provides a high color fastness woven base paper, which is prepared by the above-mentioned high color fastness woven base paper preparation method, wherein the lightfastness rating of the high color fastness woven base paper is greater than or equal to level 4.

[0015] Compared with the prior art, the preparation method of high color fastness woven base paper and the high color fastness woven base paper provided by the present application at least achieve the following beneficial effects:

[0016] The preparation method of high color fastness woven base paper of the present application, by stirring and mixing cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine salicylate, dextran hydroxypropyl trimethyl ammonium chloride, water-based polymeric diimide crosslinking agent and deionized water, a composite dyeing aid for improving the color fastness of water-based dyes is obtained; the composite dyeing aid can chemically react with fibers and water-based dye particles to form a firm chemical bond, reduce the interaction space between fibers and dye particles, and prevent water-based dye particles from falling off the fibers, significantly improve the dye fixation capacity of water-based dyes, and obtain high color fastness woven base paper.

[0017] In the process of preparing high color fastness woven base paper, first, a cationic mixture containing a large number of hydroxyl and carboxyl groups is prepared using cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine salicylate, dextran hydroxypropyl trimethyl ammonium chloride and water, and then a cross-linked cationic composite dyeing aid is prepared by utilizing the characteristic that the water-based polymeric diimide crosslinking agent can chemically react with the carboxyl groups in the mixture to form cross-linking effect; the cationic composite dyeing aid can form a chemical bond with anionic fibers to form a stable chemical structure; at the same time, the cationic composite dyeing aid can also form a chemical bond with anionic water-based dye particles to close the water-based groups of the dye particles, and form a precipitate on the surface of the fibers, so that the dye on the fibers is not easy to fall off during washing, sunning and other treatments, achieving the purpose of improving the color fastness of woven base paper. The micron-sized microcrystalline cellulose, multiple amine groups and hydroxyl groups in the composite dyeing aid are introduced as active groups, which can chemically react with specific groups in the dye particles to further improve the stability of the dye, and also can chemically react with other components in the composite dyeing aid, making the combination of fibers and dye particles more firm, and improving the color fastness of the woven base paper.

[0018] Of course, it is not necessary for any product implementing the present application to simultaneously achieve all the technical effects described above.

[0019] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0021] Figure 1 is a preparation method flowchart of high color fastness woven base paper provided by the present application. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of the components and steps illustrated in these embodiments, the numerical expressions, and numerical values set forth herein are not limiting of the scope of the present application, unless otherwise specifically stated.

[0023] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application, its application, or uses.

[0024] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification, where appropriate.

[0025] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary, and not as a limitation of the scope of the exemplary embodiments. Thus, other examples of the exemplary embodiments can have different values.

[0026] It should be noted that like reference numerals and letters in the various figures indicate similar items, and thus, once any term is defined in one figure, it is not necessary to discuss it further in connection with other figures.

[0027] In conjunction with Figure 1 , the present application provides a preparation method of high color fastness woven base paper, comprising the steps of:

[0028] The step S101 of preparing the composite dyeing aid includes: stirring cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine salicylate and deionized water, then adding dextran hydroxypropyl trimethyl ammonium chloride while stirring, and then adding water-based polycarbodiimide crosslinking agent drop by drop while stirring, and continuing to stir for 25-30 min after the dropwise addition is completed to obtain a composite dyeing aid based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine salicylate / dextran hydroxypropyl trimethyl ammonium chloride / water-based polycarbodiimide crosslinking agent, wherein the amount ratio of cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine salicylate, dextran hydroxypropyl trimethyl ammonium chloride and water-based polycarbodiimide crosslinking agent is (0.1g-0.2g):(40g-50g):(1g-2g):(5g-10g):(0.01g-0.02g);

[0029] Specifically, the amount of cationic microcrystalline cellulose is 0.1g-0.2g, for example, it can be 0.11g, 0.12g, 0.13g, 0.14g, 0.15g, 0.16g, 0.17g, 0.18g, 0.19g, 0.20g, or any range value between any two points within 0.1g-0.2g. As a cationic polymer, cationic microcrystalline cellulose provides a positive charge center, which can enhance the adsorption capacity of anionic dyes and improve the stability of the system.

[0030] The amount of sodium carboxymethyl cellulose as the main agent is 40g-50g, accounting for about 80%-85%, optionally, the amount of sodium carboxymethyl cellulose can be 41g, 42g, 43g, 44g, 45g, 46g, 47g, 48g, 49g, 50g, or any range value between any two points within 40g-50g. As an anionic water-soluble polymer material, sodium carboxymethyl cellulose can form a three-dimensional network structure, which can improve the viscosity and film-forming property of the dyeing aid, and also promote the uniform dispersion of water-based dyes.

[0031] The amount of triethanolamine salicylate is 1g-2g, which can be 1.1g, 1.2g, 1.3g, 1.4g, 1.5g, 1.6g, 1.7g, 1.8g, 1.9g, 2g, or any range value between any two points within 1g-2g. Triethanolamine salicylate has both surface activity and buffering effect, which can adjust the pH value of the system, prevent dye hydrolysis, and also reduce the interference of metal ions as a chelating agent.

[0032] The amount of dextran hydroxypropyl trimethyl ammonium chloride is 5g-10g, for example, it can be 5g, 6g, 7g, 8g, 9g, 10g, or any range value between any two points within 5g-10g. As a derivative of cationic dextran, dextran hydroxypropyl trimethyl ammonium chloride can enhance the binding force between dyes and fibers through charge neutralization and hydrogen bonding, and improve the dye uptake and color fastness.

[0033] The amount of water-based polycarbodiimide crosslinking agent is 0.01g-0.02g, for example, it can be 0.01g, 0.011g, 0.012g, 0.013g, 0.014g, 0.015g, 0.016g, 0.017g, 0.018g, 0.019g, 0.02g, or any range value between any two points within 0.01g-0.02g. As a crosslinking agent, water-based polycarbodiimide crosslinking agent can crosslink with carboxyl (-COOH) and hydroxyl (-OH) at room temperature, forming a network structure to improve the wash resistance and color fastness of the dyeing aid.

[0034] Of course, the cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine salicylate, dextran hydroxypropyl trimethyl ammonium chloride and water-based polycarbodiimide crosslinking agent together can greatly improve the color fastness of the woven base paper, the specific principle is described in detail in the technical effect of the application, which will not be repeated here.

[0035] Optionally, the length of the cationic microcrystalline cellulose is 20-200 μm, and the width is 0.05-5 μm.

[0036] Specifically, the length of the cationic microcrystalline cellulose can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, or any range value between any two points within 20-200 μm.

[0037] It should be noted that longer fibers (e.g., 100-200 μm) can form longer chain structures, and form a three-dimensional network with sodium carboxymethyl cellulose through physical entanglement or chemical crosslinking in the solution, enhancing the viscosity and stability of the dyeing aid. At the same time, long fibers can adsorb more dye molecules, improving the dye uptake. Short fibers (e.g., 20-50 μm) can play a filling role, while long fibers (100-200 μm) can significantly improve the thixotropy of the system, making the dyeing aid have good fluidity when stirring and keeping the structure stable when stationary, preventing the dye from settling.

[0038] Of course, the length of the cationic microcrystalline cellulose cannot be too long. If the length exceeds 200 μm, the fibers may be difficult to disperse uniformly due to excessive steric hindrance, leading to local agglomeration or precipitation.

[0039] The width of the cationic microcrystalline cellulose can be 0.05-5 μm, for example, 0.05 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or any range value between any two points within 0.05-5 μm.

[0040] It should be noted that the width of the cationic microcrystalline cellulose is between 0.05 μm and 5 μm, which has a higher specific surface area and a greater density of surface cation groups (such as quaternary ammonium salt), which can more efficiently adsorb anionic dyes (i.e., water-based dyes).

[0041] Of course, if the width of the cationic microcrystalline cellulose is too small (less than 0.05 μm), the fiber rigidity will be reduced, which is easy to bend or break, affecting the formation of the network structure; if the width of the cationic microcrystalline cellulose is too wide (greater than 5 μm), the uniformity of the charge distribution may decrease, reducing the adsorption efficiency.

[0042] Step S102 of preparing woven base paper includes: by weight, 1000 parts of bleached softwood pulp are put into a pulper and broken down into a pulp with a concentration of 3wt% to 5wt%. Then, the pulp is beaten by a double-disc mill. The pulp obtained after beating is pumped to a mixing tank. Then, 1 to 2 parts of composite dyeing agent are added while stirring. Then, water-based dye is added while stirring. The pulp after being mixed evenly is then subjected to the following processes: wire forming, wire dewatering, forming, pressing, drying and winding to obtain blue woven base paper. The water-based dye is turquoise water-based dye, and the amount of water-based dye added is 1‰ to 1.5‰ of the total dry mass of the pulp.

[0043] Optionally, in step S102 of preparing the woven base paper, the freeness of the pulp after beating is 30°SR to 40°SR.

[0044] For example, the freeness of the pulp after beating can be 30°SR, 31°SR, 32°SR, 33°SR, 34°SR, 35°SR, 36°SR, 37°SR, 38°SR, 39°SR, or 40°SR, or any value within any range between 30°SR and 40°SR. Double-disc beating can effectively control the degree of fiber fibrillation, and a freeness between 30°SR and 40°SR can enhance the bonding force between fibers.

[0045] Optionally, in step S102 of preparing the woven base paper, the wire mesh concentration is 0.5% to 1.0%; the dryness of the wire exit section is 24% to 26%; the dryness of the press section is greater than or equal to 40%; and the drying temperature is 130°C to 135°C.

[0046] Optionally, the web concentration can be from 0.5% to 1.0%, for example, web concentrations of 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, and 1.0%, or any range between any two points from 0.5% to 1.0%. Low-concentration web fabrication reduces fiber agglomeration and improves paper uniformity.

[0047] Optionally, the dryness of the web exit section can be 24% to 26%, for example, 24%, 25%, or 26%. It should be noted that sodium carboxymethyl cellulose (CMC) in the dyeing auxiliaries can form a flexible fiber network at a dryness of 24%-26%, reducing fiber loss during web dehydration. Of course, a dryness of 24% to 26% at the web exit section balances dehydration efficiency with fiber structure retention. If the dryness is less than 24%, insufficient web dehydration increases the pressing load and can easily lead to fiber crushing; if the dryness is greater than 26%, excessive web dehydration causes premature formation of hydrogen bonds between fibers, affecting further dehydration in the pressing section.

[0048] The dryness of the pressing section should be greater than or equal to 40%. The dryness of the pressing section directly determines the drying energy consumption. A dryness of more than 40% can significantly reduce the drying load.

[0049] The drying temperature is 130℃ to 135℃, which is suitable for fixing water-based dyes (reactive turquoise blue). Excessively high temperatures (above 135℃) can damage the molecular structure of the turquoise blue dye, causing fading; excessively low temperatures (below 130℃) will result in insufficient fixing and decreased wash resistance. Optionally, a gradient temperature increase can be used for drying; no specific limitation is made here.

[0050] Optionally, in step S102 of preparing the woven base paper, the paper basis weight is 12 g / m² to 20 g / m². Optionally, the paper basis weight can be 12 g / m². 2 13g / m 2 14g / m 2 15g / m 2 16g / m 2 17g / m 2 18g / m 2 19g / m 2 20g / m 2 It can also be 12g / m 2 Up to 20g / m 2 Any range of values ​​between any two points.

[0051] The water-based dye used in this invention is Turquoise Blue water-based dye, whose main chemical component is sulfonated / chlorosulfonated copper phthalocyanine-triazine-ethylenediamine-alkoxy complex, which is a direct dye.

[0052] In this invention, the amount of water-based dye added is 1‰ to 1.5‰ of the total dry slurry mass. For example, it can be 1‰, 1.1‰, 1.2‰, 1.3‰, 1.4‰, or 1.5‰, or any value within any range between 1‰ and 1.5‰. Increasing the amount of dye used will directly increase the cost of raw materials and may also increase the difficulty of wastewater treatment (such as increased COD and color). The dosage range of 1‰ to 1.5‰ ensures the dyeing effect while taking into account both economic efficiency and environmental protection requirements.

[0053] The present invention also provides a high color fastness woven base paper, which is prepared by the above-mentioned high color fastness woven base paper preparation method, and the lightfastness rating of the high color fastness woven base paper is greater than or equal to level 4.

[0054] This invention achieves efficient dyeing of woven base paper through the synergistic effect of composite dyeing aids and turquoise water-based dye, and also achieves a high level of lightfastness.

[0055] Example 1

[0056] This embodiment is a method for preparing high color fastness woven base paper, characterized by the following steps:

[0057] Step 1: The composite dyeing aid based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine myricetate / dextran hydroxypropyltrimethylammonium chloride / aqueous polycarbodiimide crosslinking agent is prepared by the following steps: 0.1 parts of cationic microcrystalline cellulose, 50 parts of sodium carboxymethyl cellulose, 1 part of triethanolamine myricetate and 5000 parts of deionized water are stirred. Then, 8 parts of dextran hydroxypropyltrimethylammonium chloride are added while stirring. Then, 0.01 parts of aqueous polycarbodiimide crosslinking agent are added dropwise while stirring. After the addition is completed, the reaction is continued to be stirred for 30 minutes to obtain the composite dyeing aid.

[0058] Step 2: By weight, 1000 parts of bleached softwood pulp are added to a pulper and broken down into a 3% pulp solution. Then, the pulp is beaten using a double-disc mill. The resulting pulp is pumped to a mixing tank, where 1 part of the composite dyeing agent prepared in Step 1 is added while stirring. Then, while stirring, a water-based dye at a concentration of 1‰ relative to the total dry weight of the pulp is added. After thorough mixing, the pulp undergoes sequential processes of wire forming, wire dewatering, forming, pressing, drying, and winding to produce woven base paper. The basis weight of the woven base paper is 14±2 g / m². 2 The woven base paper has a sun-resistant rating of 4.

[0059] In step 2, the freeness of the pulp after beating is 30°SR, the online concentration is 0.5%, the dryness of the screen is 24%, the dryness of the press is 40%, and the drying temperature is 130℃.

[0060] Example 2

[0061] This embodiment is a method for preparing high color fastness woven base paper, characterized by the following steps:

[0062] Step 1: The composite dyeing aid based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine myricetate / dextran hydroxypropyltrimethylammonium chloride / aqueous polycarbodiimide crosslinking agent is prepared by the following steps: 0.2 parts of cationic microcrystalline cellulose, 40 parts of sodium carboxymethyl cellulose, 2 parts of triethanolamine myricetate and 4000 parts of deionized water are stirred. Then, 10 parts of dextran hydroxypropyltrimethylammonium chloride are added while stirring. Then, 0.02 parts of aqueous polycarbodiimide crosslinking agent are added dropwise while stirring. After the addition is complete, the reaction is continued to be stirred for 30 minutes to obtain the composite dyeing aid.

[0063] Step 2: By weight, 1000 parts of bleached softwood pulp are added to a pulper and broken down into a 5% pulp solution. Then, the pulp is beaten using a double-disc mill. The resulting pulp is pumped to a mixing tank, where 2 parts of the composite dyeing agent prepared in Step 1 are added while stirring. Next, while stirring, a water-based dye at a concentration of 1.5‰ relative to the total dry pulp mass is added. After thorough mixing, the pulp undergoes sequential processes of wire forming, wire dewatering, forming, pressing, drying, and winding to produce woven base paper. The basis weight of the woven base paper is 18±2 g / m². 2 The woven base paper has a sun-resistant rating of 5.

[0064] In step 2, the freeness of the pulp after beating is 35°SR, the online concentration is 1%, the dryness of the screen is 25%, the dryness of the press is greater than 40%, and the drying temperature is 135℃.

[0065] Example 3

[0066] This embodiment is a method for preparing high color fastness woven base paper, characterized by the following steps:

[0067] Step 1: The composite dyeing aid based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine myricetate / dextran hydroxypropyltrimethylammonium chloride / aqueous polycarbodiimide crosslinking agent is prepared by the following steps: 0.15 parts of cationic microcrystalline cellulose, 50 parts of sodium carboxymethyl cellulose, 2 parts of triethanolamine myricetate and 5000 parts of deionized water are stirred. Then, while stirring, 5 parts of dextran hydroxypropyltrimethylammonium chloride are added. Then, while stirring, 0.02 parts of aqueous polycarbodiimide crosslinking agent are added dropwise. After the addition is completed, the reaction is continued to be stirred for 30 minutes to obtain the composite dyeing aid.

[0068] Step 2: By weight, 1000 parts of bleached softwood pulp are added to a pulper and broken down into a 3% pulp solution. Then, the pulp is beaten using a double-disc mill. The resulting pulp is pumped to a mixing tank, where 2 parts of the composite dyeing agent prepared in Step 1 are added while stirring. Next, while stirring, a water-based dye at a concentration of 1‰ relative to the total dry weight of the pulp is added. After thorough mixing, the pulp undergoes a series of processes including wire forming, wire dewatering, forming, pressing, drying, and winding to produce woven base paper. The basis weight of the woven base paper is 14±2 g / m². 2 The woven base paper has a sun-resistant rating of 5.

[0069] In step 2, the freeness of the pulp after beating is 30°SR, the online concentration is 0.5%, the dryness of the screen is 26%, the dryness of the press is greater than 40%, and the drying temperature is 133℃.

[0070] Example 4

[0071] This embodiment is a method for preparing high color fastness woven base paper, characterized by the following steps:

[0072] Step 1: The composite dyeing aid based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine myricetate / dextran hydroxypropyltrimethylammonium chloride / aqueous polycarbodiimide crosslinking agent is prepared by the following steps: 0.15 parts of cationic microcrystalline cellulose, 50 parts of sodium carboxymethyl cellulose, 2 parts of triethanolamine myricetate and 5000 parts of deionized water are stirred. Then, 8 parts of dextran hydroxypropyltrimethylammonium chloride are added while stirring. Then, 0.015 parts of aqueous polycarbodiimide crosslinking agent are added dropwise while stirring. After the addition is completed, the reaction is continued to be stirred for 30 minutes to obtain the composite dyeing aid.

[0073] Step 2: By weight, 1000 parts of bleached softwood pulp are added to a pulper and broken down into a 3% pulp solution. Then, the pulp is beaten using a double-disc mill. The resulting pulp is pumped to a mixing tank, where 2 parts of the composite dyeing agent prepared in Step 1 are added while stirring. Next, while stirring, a water-based dye at a concentration of 1‰ relative to the total dry weight of the pulp is added. After thorough mixing, the pulp undergoes sequential processes of wire forming, wire dewatering, forming, pressing, drying, and winding to produce woven base paper. The basis weight of the woven base paper is 15±2 g / m². 2 The woven base paper has a sun-resistant rating of 5.

[0074] In step 2, the freeness of the pulp after beating is 50°SR, the online concentration is 0.5%, the dryness of the screen is 26%, the dryness of the press is 40%, and the drying temperature is 135℃.

[0075] Comparative Example

[0076] By weight, 1000 parts of bleached softwood pulp were added to a pulper and pulped to a concentration of 3%. The pulp was then beaten using a double-disc mill. The resulting pulp was pumped to a mixing tank, where 1 part of a water-based polyurethane compound was added while stirring. Following this, a water-based dye at a concentration of 1‰ of the total oven-dry pulp mass was added while stirring. The thoroughly mixed pulp was then subjected to a series of processes including wire winding, wire dewatering, forming, pressing, drying, and winding to produce woven base paper. The water-based dye used was a turquoise blue water-based dye, added at a concentration of 1‰ to 1.5‰ of the total oven-dry pulp mass. The basis weight of the woven base paper was 14±2 g / m². 2 The woven base paper has a sun-resistant rating of level 2.

[0077] In step 2, the freeness of the pulp after beating is 30°SR, the online concentration is 0.5%, the dryness of the screen is 24%, the dryness of the press is 40%, and the drying temperature is 130℃.

[0078] Performance testing

[0079] The woven base paper prepared by the methods of Examples 1 to 4 is labeled as Example 1, Example 2, Example 3, and Example 4, respectively. The woven base paper prepared using only water-based polyurethane compounds as fixing agents is labeled as the comparative example. The performance of Examples 1, 2, 3, 4, and the comparative example was tested, and the test results are shown in Table 1 below:

[0080] Table 1. Performance test results of woven base paper in Examples 1 to 4 and comparative examples.

[0081] Sample Index Quantitative (g / m 2 )]]> L value b value fastness rating (scale) Example One 14 71.82 -27.36 4 Example Two 19 71.27 -29.04 5 Example Three 13 71.94 -29.94 5 Example Four 14 71.79 -30.21 5 Comparative Example 14 70.05 -25.75 2

[0082] The data in the table above shows that the woven base paper prepared in Examples 1 to 4 has a low b value (the lower the b value, the more bluish the color of the surface paper) and a high lightfastness rating, indicating that the woven base paper prepared in Examples 1 to 4 has a bright color and high color fastness.

[0083] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method of making a high color fastness woven base paper, characterized by, The method comprises the steps of: The step of preparing the composite dyeing agent comprises: stirring cationic microcrystalline cellulose, sodium carboxymethyl cellulose, triethanolamine salicylate and deionized water, then adding dextran hydroxypropyl trimethyl ammonium chloride while stirring, and then adding water-based polycarbodiimide crosslinking agent drop by drop while stirring, and continuing to stir for 25 min to 30 min after the dropwise addition is completed to obtain a composite dyeing agent based on cationic microcrystalline cellulose / sodium carboxymethyl cellulose / triethanolamine salicylate / dextran hydroxypropyl trimethyl ammonium chloride / water-based polycarbodiimide crosslinking agent, wherein the amount ratio of the cationic microcrystalline cellulose, the sodium carboxymethyl cellulose, the triethanolamine salicylate, the dextran hydroxypropyl trimethyl ammonium chloride and the water-based polycarbodiimide crosslinking agent is (0.1g-0.2g):(40g-50g):(1g-2g):(5g-10g):(0.01g-0.02g); The step of preparing the woven base paper comprises: putting 1000 parts of bleached coniferous wood pulp into a pulper by weight fraction, and disintegrating the pulp into a slurry with a concentration of 3wt% to 5wt%, then beating the pulp with a double-disc refiner, pumping the obtained pulp after beating to a mixing pool, then adding 1 part to 2 parts of the composite dyeing agent while stirring, and then adding water-based dye while stirring, and then obtaining blue woven base paper after the uniformly mixed pulp is subjected to the processes of wire feeding, wire section dehydration, molding, pressing, drying and winding in sequence; wherein the water-based dye is a water-based turquoise dye, and the amount of the water-based dye added is 1‰ to 1.5‰ of the total mass of the absolutely dry pulp.

2. The method of producing a high color fastness woven base paper according to claim 1, characterized by, The length of the cationic microcrystalline cellulose is 20μm to 200μm, and the width is 0.05μm to 5μm.

3. The method of making a high color fastness woven base paper according to claim 1, characterized in that, In the step of preparing the woven base paper, the beating degree of the pulp after beating is 30°SR to 40°SR.

4. The method of making a high color fastness woven base paper according to claim 1, characterized in that, In the step of preparing the woven base paper, the wire feeding concentration is 0.5% to 1.0%, the dryness of the wire section is 24% to 26%, the dryness of the press section is greater than or equal to 40%, and the drying temperature is 130℃ to 135℃.

5. The method of making a high color fastness woven base paper according to claim 1, characterized in that, The step of preparing the woven base paper, the papermaking basis weight is 12 g / m 2 to 20 g / m 2 .

6. A high color fastness woven base paper, characterized by The high-color-fastness woven base paper is prepared by the method for preparing high-color-fastness woven base paper according to claims 1 to 4, and the lightfastness grade of the high-color-fastness woven base paper is greater than or equal to 4.

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