Identifiable traceable regenerated cellulose fibers and methods of making the same

Abstract

The application provides a kind of identifiable traceable regenerated cellulose fiber and its preparation method, relating to the field of regenerated cellulose fiber.The preparation method of the identifiable traceable regenerated cellulose fiber includes the following steps: preparing identification traceable marker dispersion system, preparing blending spinning dope, preparing identifiable traceable regenerated cellulose fiber;The preparation of the identification traceable marker dispersion system includes the following steps: preparing carbon quantum dots composite acetylacetone terbium, grinding and dispersing, microcapsule coating.The identifiable traceable regenerated cellulose fiber of the application can not only be qualitatively identified, but also effectively realize quantitative detection of regenerated cellulose fiber, and can determine the amount of regenerated cellulose fiber in downstream woven or non-woven products;It can also maintain good qualitative identification and quantitative traceability performance for a long time.

Description

Technical Field

[0001] This invention relates to the field of regenerated cellulose fibers, and in particular to an identifiable and traceable regenerated cellulose fiber and its preparation method. Background Technology

[0002] Viscose fiber is one of the important types of textile fibers. It is a regenerated cellulose fiber produced by using natural cellulose, which is abundant in nature, through the viscose process. Viscose fiber is characterized by its smooth and cool texture, moisture absorption and breathability, antistatic properties, vibrant colors, good color fastness, and excellent comfort. It is currently widely used in various clothing and nonwoven fabrics.

[0003] In recent years, with the intensification of market competition and the expansion of viscose fiber production capacity, differentiated and functional viscose fibers have become an important development direction in the viscose fiber industry. Various viscose fiber manufacturers have developed their own brands. To improve market competition and prevent the occurrence of raw material adulteration and counterfeit products, it is necessary to research traceability methods for fiber sources and prepare traceable regenerated cellulose fibers to ensure the interests of both manufacturers and consumers.

[0004] Currently, existing identifiable or traceable cellulose fibers are generally prepared by adding markers. As markers, they should have the characteristics of low cost, easy availability, stable chemical properties, safety and harmlessness to humans and the environment, difficulty in counterfeiting, and obvious detection characteristics.

[0005] Chinese patent CN110042490A discloses a viscose fiber containing a tracer label and its preparation method. It uses rare earth metal chelates as the identification agent, which is simple to identify, requires a small amount, has low cost, and is easy to industrialize.

[0006] Chinese patent CN117888220A discloses an environmentally friendly and traceable bamboo pulp fiber, its preparation method, and its application. It uses rare earth oxides composed of one or more of lanthanum oxide, cerium oxide, neodymium oxide, and samarium oxide as markers added to bamboo pulp fiber. This allows the unique properties of rare earth oxides as traceability markers to be utilized, providing traceability throughout the entire industrial chain. At the same time, it meets the requirements for cellulose fiber markers, which is conducive to its promotion and application in the daily chemical industry.

[0007] However, existing technologies can only perform qualitative traceability testing of fibers. Limited by the poor stability and uneven distribution of markers within the fibers, as well as significant marker losses during the preparation process, quantitative detection of fibers is impossible. This makes it impossible to accurately determine the amount of regenerated cellulose fiber used in downstream woven or nonwoven products. Furthermore, the markers used in the preparation of existing identifiable and traceable fibers (such as rare earth metal chelates) have poor acid resistance. Directly adding them to viscose spinning solutions can easily lead to decomposition or loss in acidic coagulation baths. This not only affects the reliability of subsequent identification and traceability but also interferes with the spinning process of regenerated cellulose fibers, reducing the stability of the spinning process. Summary of the Invention

[0008] To address the technical problems existing in the prior art, this invention provides a method for preparing identifiable and traceable regenerated cellulose fibers. Based on existing regenerated cellulose fiber production processes and production lines, the prepared regenerated cellulose fibers can not only be qualitatively identified and traced, but also effectively achieve quantitative detection, determining the amount of regenerated cellulose fibers used in downstream woven or nonwoven products. Simultaneously, the identifiable and traceable markers used exhibit good stability during preparation, effectively avoiding losses during the preparation process and interference with the spinning process. Furthermore, the identifiable and traceable markers used have good stability in the regenerated cellulose fibers, maintaining good qualitative identification and quantitative traceability performance over a long period.

[0009] The present invention also provides a method for using an identifiable and traceable regenerated cellulose fiber.

[0010] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing identifiable and traceable regenerated cellulose fiber includes the following steps: preparing an identification and traceability marker dispersion system, preparing a blending spinning solution, and preparing identifiable and traceable regenerated cellulose fiber; The preparation of the identification and traceability marker dispersion system includes the following steps: preparing carbon quantum dot composite terbium acetylacetonate, grinding and dispersing, and microcapsule encapsulation; The method for preparing carbon quantum dot composite terbium acetylacetonate is as follows: green fluorescent carbon quantum dots are added to an aqueous solution of terbium acetate, mixed evenly, heated to 55-65°C, kept at the temperature, and acetylacetonate is added to react. The solid is then separated and collected, washed, and dried to obtain carbon quantum dot composite terbium acetylacetonate. The grinding and dispersion method is as follows: carbon quantum dot composite terbium acetylacetonate is added to an organic dispersion containing methyl methacrylate and allyl methacrylate, and then ground and dispersed until the particle size D97 of the carbon quantum dot composite terbium acetylacetonate is ≤0.950um to obtain an organic dispersion system. The microcapsule encapsulation method involves mixing an organic dispersion system, deionized water, and an emulsifier to prepare an emulsion, and then, in the presence of an initiator, performing a polymerization reaction to microcapsule carbon quantum dot composite terbium acetylacetonate to obtain an identification and traceability marker dispersion system. The method for preparing the blended spinning solution is as follows: the identification and traceability marker dispersion system is mixed with the modified cellulose fiber spinning solution to obtain the blended spinning solution. Identifiable and traceable regenerated cellulose fibers are obtained by spinning the aforementioned blended spinning solution.

[0011] Furthermore, the method for preparing carbon quantum dot composite terbium acetylacetonate is as follows: green fluorescent carbon quantum dots are added to an aqueous solution of terbium acetate, mixed evenly, heated to 55-65°C, acetylacetonate is added while maintaining the temperature, the pH is adjusted to 7.5-8.5, the reaction is maintained at the temperature, the solid is separated and collected, and the solid is washed and dried to obtain carbon quantum dot composite terbium acetylacetonate.

[0012] Furthermore, the grinding and dispersion method involves adding carbon quantum dot composite terbium acetylacetonate to an organic dispersion containing methyl methacrylate and allyl methacrylate, controlling the grinding temperature at 20-25℃ and the grinding speed at 3000-3500 r / min, and grinding and dispersing until the particle size D97 of the carbon quantum dot composite terbium acetylacetonate is ≤0.950 μm, thereby obtaining an organic dispersion system.

[0013] Furthermore, the microcapsule encapsulation method involves mixing an organic dispersion system, deionized water, and an emulsifier, and then emulsifying and dispersing the mixture under conditions of oxygen isolation, a temperature of 35-45°C, and a stirring speed of 2000-2500 r / min to prepare an emulsion. An initiator is then added to the emulsion, and under stirring conditions, the temperature is raised to 60-78°C and maintained for polymerization for 120-180 min. Afterward, the temperature is lowered to 40-50°C and stirred for 60-90 min to obtain a dispersion system for identification and traceability markers.

[0014] Preferably, in the preparation of carbon quantum dot composite terbium acetylacetonate, the concentration of terbium acetate in the aqueous solution of terbium acetate is 10-15 wt%. The mass ratio of green fluorescent carbon quantum dots to terbium acetate is 1-2:1; The molar amount of acetylacetone is at least four times the molar amount of terbium acetate.

[0015] Preferably, in the grinding and dispersion process, the mass ratio of methyl methacrylate to allyl methacrylate in the organic dispersion is 4-6:1; The mass ratio of the carbon quantum dot composite terbium acetylacetonate to the organic dispersion is 1-2:1.

[0016] Preferably, in the microcapsule encapsulation, the mass fraction of the organic dispersion system in the emulsion is 40-60%, the mass fraction of the emulsifier is 4.5-7.5%, and the remainder is deionized water; The particle size D97 of the organic phase in the emulsion is ≤1.105μm.

[0017] Preferably, in the microcapsule encapsulation process, the polymerization reaction is controlled at a temperature of 60-78°C, a stirring speed of 750-1000 r / min, and a holding time of 120-180 min. The microcapsule particle size D97 in the prepared identification and traceability marker dispersion system is ≤1.295μm.

[0018] Preferably, in the preparation of the blended spinning solution, the added mass of terbium in the identification and traceability marker dispersion system is controlled to be 60-80 ppm of the methyl cellulose content in the modified cellulose fiber spinning solution; The modified cellulose fiber spinning solution is prepared by mixing cellulose fiber spinning solution with a modifier; the cellulose fiber spinning solution contains 8.60-9.10 wt% methyl cellulose, 4.50-5.10 wt% sodium hydroxide, 36-52 s falling ball viscosity, 15-20 mL 10% NH4Cl ripening degree, and 2.15-2.50 wt% sulfur.

[0019] Preferably, the amount of the denaturant added is 2.5-4.5% of the methyl cellulose content in the cellulose fiber spinning solution; The denaturant consists of urea and polyethylene glycol PEG-1500.

[0020] Furthermore, the method for preparing identifiable and traceable regenerated cellulose fibers is as follows: the blending spinning solution is spun in a coagulation bath to obtain a shaped filament bundle; the shaped filament bundle is then cut, web-laid, deacidified, washed in a first water bath, desulfurized in a desulfurization bath, washed in a second water bath, acid-washed in a third water bath, and then oiled in an oil bath, followed by pressing, dehydration, and drying to obtain identifiable and traceable regenerated cellulose fibers.

[0021] Preferably, the coagulation bath contains 90-100 g / L of sulfuric acid and 285-295 g / L of sodium sulfate; The web is formed using a web-laying liquid with a temperature ≥97℃. The solute in the desulfurization bath is sodium hydroxide or sodium sulfide, with a concentration of 3-5 g / L; The acid bath uses acetic acid or lactic acid with a concentration of 5-8 g / L.

[0022] A traceable regenerated cellulose fiber is prepared using the aforementioned preparation method.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The method for preparing identifiable and traceable regenerated cellulose fiber of the present invention, in the preparation of the identifiable and traceable marker dispersion system, uses rare earth complex (terbium acetylacetonate) which is basically non-toxic to the human body and green fluorescent carbon quantum dots as raw materials to prepare identifiable and traceable markers (carbon quantum dot composite terbium acetylacetonate). The bright green fluorescence of terbium acetylacetonate is enhanced by using green fluorescent carbon quantum dots to improve the identifiability of the fiber; then, the particle size of the identifiable and traceable markers is controlled by grinding and dispersion to improve their distribution uniformity in the fiber; then, in the microencapsulation process, modified polymethyl methacrylate with high transparency is used to microencapsulate and protect the carbon quantum dot composite terbium acetylacetonate, which not only effectively reduces the destructive loss of fluorescent substances in subsequent production processes, but also enhances its durability and stability in the fiber, which is beneficial to the long-term stability of the fiber. The method achieves excellent traceability performance. Furthermore, the use of highly transparent modified polymethyl methacrylate to microencapsulate carbon quantum dots combined with terbium acetylacetonate does not affect the fiber's fluorescence reaction under ultraviolet light, facilitating rapid qualitative identification and detection. These technologies work synergistically to enable not only traceable qualitative identification of fibers but also effective quantitative detection of regenerated cellulose fibers, determining the amount of regenerated cellulose fibers used in downstream woven or nonwoven products. The identifiable traceability markers used exhibit good stability during preparation, effectively avoiding losses and interference with the spinning process. Moreover, the identifiable traceability markers remain stable within the regenerated cellulose fibers, maintaining excellent qualitative and quantitative traceability performance over a long period.

[0024] (2) The identifiable and traceable regenerated cellulose fiber of the present invention has both qualitative identification and quantitative traceability performance, and the qualitative and quantitative detection methods are convenient. Its qualitative identification and detection can be carried out by ultraviolet light irradiation, and quantitative traceability is obtained by detecting the terbium element in the fiber through inductively coupled plasma mass spectrometry. It can effectively identify downstream woven or nonwoven products and quantitatively characterize the amount of the fiber used in the product.

[0025] (3) The fluorescence intensity of the identifiable and traceable regenerated cellulose fiber of the present invention is 1236-1506 a.u, which can effectively realize the qualitative identification and traceability of the fiber; and the terbium content in the fiber is 58.0-75.8 ppm, which can realize the quantitative characterization of the fiber based on the terbium content in the fiber; at the same time, the fiber can also maintain good washability and durability for a long time. After 50 water washes, the fluorescence intensity retention rate of the fiber can reach 99.5%, and the terbium content retention rate in the fiber can reach 95%, which has long-term qualitative identification and quantitative traceability performance. Detailed Implementation

[0026] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described. It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, "first," "second," etc., are used to distinguish similar objects and are not used to describe a particular order or sequence. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] This invention provides a method for preparing identifiable and traceable regenerated cellulose fibers, comprising the following steps: preparing an identification and traceability marker dispersion system, preparing a blending spinning solution, and preparing identifiable and traceable regenerated cellulose fibers.

[0029] The preparation of the identification and traceability marker dispersion system includes the following steps: preparing carbon quantum dot composite terbium acetylacetonate, grinding and dispersing, and microcapsule encapsulation.

[0030] The method for preparing carbon quantum dot composite terbium acetylacetonate is as follows: green fluorescent carbon quantum dots are added to an aqueous solution of 10-15 wt% terbium acetate, controlling the mass ratio of green fluorescent carbon quantum dots to terbium acetate to be 1-2:1. The mixture is ultrasonically dispersed for 20-30 min at an ultrasonic frequency of 25-40 kHz and a temperature of 35-50℃. Then, stirring is started (300-500 r / min), and the temperature is raised to 55-65℃. After maintaining the temperature, acetylacetonate is added, and the pH of the mixture is adjusted to 7.5-8.5 using an alkaline pH adjuster (triethanolamine, ammonia, or sodium hydroxide). The mixture is stirred for 50-80 min to obtain a dispersion of carbon quantum dot composite terbium acetylacetonate. The dispersion is filtered, and the solid is collected. The solid is washed with water and dried to obtain carbon quantum dot composite terbium acetylacetonate.

[0031] In the preparation of carbon quantum dot composite terbium acetylacetonate, the molar amount of acetylacetonate is at least 4 times the molar amount of terbium acetate.

[0032] In this embodiment of the invention, since terbium acetylacetonate exhibits bright green fluorescence, the bright green fluorescence of terbium acetylacetonate is enhanced by green fluorescent carbon quantum dots, which effectively improves the fiber's recognizability; and through the fluorescence enhancement effect, the amount of terbium acetylacetonate used is reduced, thereby reducing production costs.

[0033] The grinding and dispersion method is as follows: the carbon quantum dot composite terbium acetylacetonate obtained above is added to an organic dispersion, and the mass ratio of carbon quantum dot composite terbium acetylacetonate to organic dispersion is controlled at 1-2:1. Grinding and dispersion are carried out at a temperature of 20-25℃ and a grinding speed of 3000-3500 r / min. The particle size is monitored in real time during the grinding process until the particle size D97 of carbon quantum dot composite terbium acetylacetonate is ≤0.950um, thus obtaining an organic dispersion system (i.e., the grinding and dispersion of carbon quantum dot composite terbium acetylacetonate).

[0034] In the grinding and dispersion process, the organic dispersion used is composed of methyl methacrylate and allyl methacrylate, with a mass ratio of methyl methacrylate to allyl methacrylate of 4-6:1.

[0035] In this embodiment of the invention, the particle size D97 of the carbon quantum dot composite terbium acetylacetonate is controlled by grinding and dispersing to avoid the subsequent microcapsules being too large and affecting the stability of the spinning process; at the same time, it improves the uniformity of its distribution in the fiber and improves the accuracy of subsequent quantitative detection of the fiber.

[0036] The microcapsule encapsulation method is as follows: the organic dispersion system obtained above is added to a reaction vessel, and then emulsifier and deionized water are added. Emulsification and dispersion are carried out under conditions of oxygen isolation, temperature of 35-45℃, and stirring speed of 2000-2500 r / min until an emulsion with an organic phase particle size D97 ≤ 1.105 μm is formed. An initiator is added to the emulsion, the temperature is raised to 60-78℃, and the mixture is kept at this temperature. Polymerization reaction is carried out at a stirring speed of 750-1000 r / min. After the reaction is kept at this temperature for 120-180 min, the stirring speed is reduced to 350-600 r / min, and stirring is continued at a temperature of 40-50℃ for 60-90 min to obtain a microcapsule dispersion of modified polymethyl methacrylate coated with carbon quantum dots and terbium acetylacetonate (i.e., the identification and traceability marker dispersion system). The microcapsule particle size D97 in the microcapsule dispersion system is measured to be ≤ 1.295 μm.

[0037] In the microcapsule encapsulation, the mass fraction of the organic dispersion system in the emulsion is 40-60%, the mass fraction of the emulsifier is 4.5-7.5%, and the balance is deionized water.

[0038] In the microcapsule encapsulation, the emulsifier is one of the following: sodium salt of styrene-maleic anhydride copolymer, sodium dodecyl sulfate, or sodium dodecylbenzene sulfonate; The initiator is benzoyl peroxide or azobisisobutyronitrile, and the amount of initiator added is 0.5-2.5% of the mass of the organic dispersion system in the emulsion.

[0039] In this embodiment of the invention, carbon quantum dot-composite terbium acetylacetonate is microencapsulated and protected using highly transparent modified polymethyl methacrylate. This not only effectively reduces the destructive loss of fluorescent substances during subsequent production processes but also enhances its durability and stability in the fiber, facilitating long-term quantitative traceability of the fiber. Furthermore, using highly transparent modified polymethyl methacrylate for microencapsulation of carbon quantum dot-composite terbium acetylacetonate does not affect the fluorescence reaction of the fiber under ultraviolet light, thus facilitating rapid qualitative identification and detection of the fiber.

[0040] The method for preparing the blended spinning solution is as follows: Cellulose pulp with an average degree of polymerization of 650-755 is used as raw material, and a cellulose fiber spinning solution is obtained through a viscose preparation process; a modifier is added to the cellulose fiber spinning solution, and the amount of modifier added is controlled to be 2.5-4.5% of the methyl cellulose content in the cellulose fiber spinning solution, to obtain a modified cellulose fiber spinning solution; using a pre-spinning injection device, the identification and traceability marker dispersion system (a microcapsule dispersion system of modified polymethyl methacrylate-coated carbon quantum dots and terbium acetylacetonate) obtained above is added to the modified cellulose fiber spinning solution, and the mass of terbium added in the identification and traceability marker dispersion system is controlled to be 60-80 ppm of the methyl cellulose content in the modified cellulose fiber spinning solution, to obtain the blended spinning solution.

[0041] The prepared blend spinning solution contains 8.60-9.10 wt% methyl cellulose, 4.50-5.10 wt% sodium hydroxide, a falling ball viscosity of 36-52 s, a ripening degree of 15-20 mL (10% NH4Cl), and a sulfur content of 2.15-2.50 wt%. The denaturant is a mixture of urea and polyethylene glycol (molecular weight 1500, PEG-1500); urea and polyethylene glycol can be mixed in any ratio, such as 1-2:1-2, etc.

[0042] The method for preparing identifiable and traceable regenerated cellulose fibers is as follows: the blended spinning solution obtained above is used to spin the fibers through a coagulation bath at a temperature of 45-50℃. The nascent filament bundles are drawn to obtain shaped filament bundles. The shaped filament bundles are then cut, laid into a web, deacidified, washed with acid, washed with water in the first water bath, desulfurized in the desulfurization bath, washed with water in the second water bath, washed with acid in the third water bath, and washed with water in the oil bath. After these refining baths, the fibers are pressed, dehydrated, and dried to obtain identifiable and traceable regenerated cellulose fibers.

[0043] In the preparation of the identifiable and traceable regenerated cellulose fiber, the coagulation bath contains 90-100 g / L of sulfuric acid and 285-295 g / L of sodium sulfate.

[0044] The web-laying method is web-laying with a web-laying solution. The web-laying solution used is deionized water, and the temperature of the web-laying solution is ≥97℃. High-temperature web-laying allows carbon disulfide in the fiber to be evaporated as much as possible, reducing the sulfide content in the fiber.

[0045] The acid pickling, first water rinse, second water rinse, and third water rinse all use deionized water, and the water temperature is controlled at 65-80℃.

[0046] The solute in the desulfurization bath is sodium hydroxide or sodium sulfide, with a concentration of 3-5 g / L, and the temperature of the desulfurization bath is 70-80℃.

[0047] The acid bath uses a weak acid, preferably acetic acid or lactic acid, with a concentration of 5-8 g / L and a temperature of 40-60℃. The weak acid reacts with metals and ash on the fiber to improve the cleanliness of the fiber, thereby enhancing its luster.

[0048] The concentration of the oil agent in the upper oil bath is 4-9 g / L, and the temperature of the upper oil bath is 55-60℃. The pressing pressure after each of the aforementioned washing or bath treatments is 0.10-0.15 MPa; the fiber is pressed and dehydrated using a high-pressure rolling mill before entering the drying process, with a pressing and dehydration pressure of 0.35-0.4 MPa, and the moisture regain of the fiber after pressing and dehydration is 120-135%.

[0049] The drying process uses steam drying, with a steam pressure of 0.50-0.60 MPa, a drying temperature of 100-120℃, and a drying time of 25-40 min.

[0050] Embodiments of the present invention also provide identifiable and traceable regenerated cellulose fibers prepared by the aforementioned method.

[0051] The present invention will be further described below with reference to some specific embodiments.

[0052] Example 1 This embodiment provides a method for preparing identifiable and traceable regenerated cellulose fibers with a specification of 1.33 dtex × 38 mm. The specific steps are as follows: 1. Preparation of a dispersion system for identification and traceability markers (1) Preparation of carbon quantum dot composite terbium acetylacetonate Green fluorescent carbon quantum dots (purchased from Xi'an Qiyue Biotechnology Co., Ltd.) were added to a 10wt% terbium acetate aqueous solution, with the mass ratio of green fluorescent carbon quantum dots to terbium acetate controlled at 2:1. The mixture was ultrasonically dispersed for 30 min at an ultrasonic frequency of 25 kHz and a temperature of 35 °C. Then, stirring was started (300 r / min), and the temperature was raised to 55 °C. After maintaining the temperature, acetylacetone was added, and the pH of the mixture was adjusted to 7.5 using an alkaline pH adjuster (triethanolamine). The mixture was stirred for 80 min to obtain a dispersion of carbon quantum dots composite terbium acetylacetone. The dispersion was filtered, and the solids were collected. The solids were washed with water and dried to obtain carbon quantum dots composite terbium acetylacetone.

[0053] The molar amount of acetylacetone is four times that of terbium acetate.

[0054] (2) Grinding and dispersing The carbon quantum dot composite terbium acetylacetonate obtained above was added to an organic dispersion, and the mass ratio of carbon quantum dot composite terbium acetylacetonate to organic dispersion was controlled at 1:1. Grinding and dispersion were carried out at a temperature of 20℃ and a grinding speed of 3500 r / min. The particle size was monitored in real time during the grinding process until the particle size of carbon quantum dot composite terbium acetylacetonate D97 = 0.815 μm, thus obtaining an organic dispersion system.

[0055] The organic dispersion used consists of methyl methacrylate and allyl methacrylate, with a mass ratio of methyl methacrylate to allyl methacrylate of 4:1.

[0056] (3) Microcapsule coating The organic dispersion system obtained above was added to a reaction vessel, and emulsifier (sodium dodecyl sulfate) and deionized water were added. Emulsification and dispersion were carried out under conditions of oxygen isolation, temperature of 35°C, and stirring speed of 2500 r / min until an emulsion with an organic phase particle size D97 = 1.023 μm was formed. Initiator (azobisisobutyronitrile) was added to the emulsion, the temperature was raised to 60°C, and the temperature was maintained. Polymerization reaction was carried out under conditions of stirring speed of 1000 r / min. After the reaction was maintained at this temperature for 120 min, the stirring speed was reduced to 350 r / min, and stirring was continued at a temperature of 50°C for 90 min to obtain a microcapsule dispersion system of modified polymethyl methacrylate coated with carbon quantum dots and terbium acetylacetonate (i.e., the identification and traceability marker dispersion system). The particle size of the microcapsules in the microcapsule dispersion system was measured to be D97 = 1.156 μm.

[0057] In the emulsion, the mass fraction of the organic dispersion system is 50%, the mass fraction of the emulsifier is 4.5%, and the remainder is deionized water.

[0058] The amount of initiator (azobisisobutyronitrile) added is 0.9% of the mass of the organic dispersion system in the emulsion.

[0059] 2. Preparation of blend spinning solution Cellulose pulp with an average degree of polymerization of 755 was used as raw material, and cellulose fiber spinning solution was prepared by viscose preparation process. A modifier was added to the cellulose fiber spinning solution, and the amount of modifier added was controlled to be 4.5% of the methyl cellulose content in the cellulose fiber spinning solution to obtain a modified cellulose fiber spinning solution. Using a pre-spinning injection device, the identification and traceability marker dispersion system (a microcapsule dispersion system of modified polymethyl methacrylate-coated carbon quantum dots and terbium acetylacetonate) obtained above was added to the modified cellulose fiber spinning solution, and the mass of terbium added in the identification and traceability marker dispersion system was controlled to be 60 ppm of the methyl cellulose content in the modified cellulose fiber spinning solution to obtain a blended spinning solution.

[0060] The cellulose fiber spinning solution contains 9.10 wt% cellulose A, 5.10 wt% sodium hydroxide, 52 s falling ball viscosity, 20 mL (10% NH4Cl) curing degree, and 2.50 wt% sulfur.

[0061] The denaturant is a mixture of urea and polyethylene glycol PEG-1500; the mass ratio of urea to polyethylene glycol PEG-1500 is 1:1.

[0062] 3. Preparation of identifiable and traceable regenerated cellulose fibers The blended spinning solution obtained above is used for spinning in a coagulation bath at a temperature of 45°C. The nascent filament bundle is drawn to obtain a shaped filament bundle. The shaped filament bundle is then cut, laid into a web, deacidified, washed with acid, washed with water in the first water, desulfurized in a desulfurization bath, washed with water in the second water, washed with acid in a third water, washed with water in the third water, and then washed with oil in a refining bath. After pressing, dehydration, and drying, identifiable and traceable regenerated cellulose fibers are obtained.

[0063] The coagulation bath contains 90 g / L sulfuric acid and 285 g / L sodium sulfate.

[0064] The web-laying method is web-laying liquid formation, using deionized water at a temperature of 97°C. High-temperature web-laying allows carbon disulfide in the fiber to be evaporated as much as possible, reducing the sulfide content in the fiber.

[0065] The acid pickling, first water rinse, second water rinse, and third water rinse all use deionized water, and the water temperature is controlled at 65℃.

[0066] The solute in the desulfurization bath is sodium hydroxide with a concentration of 3 g / L, and the temperature of the desulfurization bath is 70℃.

[0067] The acid bath uses acetic acid with a concentration of 5 g / L and a temperature of 60°C.

[0068] The concentration of the oil agent in the upper oil bath is 4 g / L, and the temperature of the upper oil bath is 55℃.

[0069] The pressing pressure after each of the aforementioned washing or bath treatments is 0.10 MPa; the fiber is dehydrated by pressing with a high-pressure rolling mill before entering the drying process, and the pressing pressure of the high-pressure rolling mill is 0.35 MPa. The moisture regain of the fiber after pressing and dehydration is 135%.

[0070] The drying process uses steam drying, with a steam pressure of 0.50 MPa, a drying temperature of 100°C, and a drying time of 40 minutes.

[0071] This embodiment also provides identifiable and traceable regenerated cellulose fibers prepared using the aforementioned method.

[0072] The identifiable and traceable regenerated cellulose fiber in this embodiment exhibits green fluorescence under ultraviolet light. The fluorescence intensity of the fiber was tested using an FS5 fluorescence spectrometer, with the excitation wavelength controlled at 365.0 nm, the spacing at 2.0 nm, and the test range at 420-540 nm. The fluorescence intensity of the fiber was found to be 1236 a.u., which effectively enables qualitative identification and traceability of the fiber. Inductively coupled plasma mass spectrometry was used to detect terbium in the fiber, and the terbium content was found to be 58.0 ppm, enabling quantitative traceability of the fiber based on its terbium content.

[0073] Furthermore, using the 4N procedure of GB / T8629-2017 "Home Washing and Drying Procedures for Textile Testing" as a standard washing process, the identifiable and traceable regenerated cellulose fiber of this embodiment was continuously washed 50 times. The fluorescence intensity of the fiber was 1229 a.u and the terbium content was 55.1 ppm, which can maintain good washability and durability for a long time, thereby ensuring the long-term qualitative identification and quantitative traceability performance of the fiber.

[0074] Example 2 This embodiment provides a method for preparing identifiable and traceable regenerated cellulose fibers with a specification of 1.56 dtex × 38 mm. The specific steps are as follows: 1. Preparation of a dispersion system for identification and traceability markers (1) Preparation of carbon quantum dot composite terbium acetylacetonate Green fluorescent carbon quantum dots (purchased from Xi'an Qiyue Biotechnology Co., Ltd.) were added to an aqueous solution of 12.6 wt% terbium acetate, with the mass ratio of green fluorescent carbon quantum dots to terbium acetate controlled at 1.5:1. The mixture was ultrasonically dispersed for 25 min at an ultrasonic frequency of 33 kHz and a temperature of 45 °C. Then, stirring was started (400 r / min), and the temperature was raised to 60 °C. After maintaining the temperature, acetylacetone was added, and the pH of the mixture was adjusted to 8.0 using an alkaline pH adjuster (ammonia). The mixture was stirred for 70 min to obtain a dispersion of carbon quantum dots composite terbium acetylacetone. The dispersion was filtered, and the solids were collected. The solids were washed with water and dried to obtain carbon quantum dots composite terbium acetylacetone.

[0075] The molar amount of acetylacetone is 4.5 times that of terbium acetate.

[0076] (2) Grinding and dispersing The carbon quantum dot composite terbium acetylacetonate obtained above was added to an organic dispersion, and the mass ratio of carbon quantum dot composite terbium acetylacetonate to organic dispersion was controlled at 1.5:1. Grinding and dispersion were carried out at a temperature of 23℃ and a grinding speed of 3200 r / min. The particle size was monitored in real time during the grinding process until the particle size of carbon quantum dot composite terbium acetylacetonate D97 = 0.886 μm, thus obtaining an organic dispersion system.

[0077] The organic dispersion used consists of methyl methacrylate and allyl methacrylate, with a mass ratio of methyl methacrylate to allyl methacrylate of 5:1.

[0078] (3) Microcapsule coating The organic dispersion system obtained above was added to a reaction vessel, and emulsifier (sodium dodecyl sulfate) and deionized water were added. Emulsification and dispersion were carried out under the conditions of oxygen isolation, temperature of 40°C, and stirring speed of 2300 r / min until an emulsion with an organic phase particle size D97 = 1.078 μm was formed. Initiator (azobisisobutyronitrile) was added to the emulsion, the temperature was raised to 65°C, and the temperature was maintained. Polymerization reaction was carried out under the condition of stirring speed of 850 r / min. After the reaction was maintained at this temperature for 150 min, the stirring speed was reduced to 500 r / min, and stirring was continued at a temperature of 45°C for 75 min to obtain a microcapsule dispersion system of modified polymethyl methacrylate coated with carbon quantum dots and terbium acetylacetonate (i.e., the identification and traceability marker dispersion system). The particle size of the microcapsules in the microcapsule dispersion system was measured to be D97 = 1.207 μm.

[0079] In the emulsion, the mass fraction of the organic dispersion system is 50%, the mass fraction of the emulsifier is 6.3%, and the remainder is deionized water.

[0080] The amount of initiator (azobisisobutyronitrile) added is 1.5% of the mass of the organic dispersion system in the emulsion.

[0081] 2. Preparation of blend spinning solution Cellulose pulp with an average degree of polymerization of 700 was used as raw material, and cellulose fiber spinning solution was prepared by viscose preparation process. A modifier was added to the cellulose fiber spinning solution, and the amount of modifier added was controlled to be 3.0% of the cellulose A content in the cellulose fiber spinning solution to obtain a modified cellulose fiber spinning solution. Using a pre-spinning injection device, the identification and traceability marker dispersion system (a microcapsule dispersion system of modified polymethyl methacrylate-coated carbon quantum dots and terbium acetylacetonate) obtained above was added to the modified cellulose fiber spinning solution, and the mass of terbium added in the identification and traceability marker dispersion system was controlled to be 72 ppm of the cellulose A content in the modified cellulose fiber spinning solution to obtain a blended spinning solution.

[0082] The cellulose fiber spinning solution contained 8.85 wt% cellulose A, 4.75 wt% sodium hydroxide, 44 s falling ball viscosity, 16.9 mL (10% NH4Cl) maturity, and 2.32 wt% sulfur.

[0083] The denaturant is a mixture of urea and polyethylene glycol PEG-1500; the mass ratio of urea to polyethylene glycol PEG-1500 is 2:1.

[0084] 3. Preparation of identifiable and traceable regenerated cellulose fibers The blended spinning solution obtained above is used for spinning in a coagulation bath at a temperature of 45°C. The nascent filament bundle is drawn to obtain a shaped filament bundle. The shaped filament bundle is then cut, laid into a web, deacidified, washed with acid, washed with water in the first water, desulfurized in a desulfurization bath, washed with water in the second water, washed with acid in a third water, washed with water in the third water, and then washed with oil in a refining bath. After pressing, dehydration, and drying, identifiable and traceable regenerated cellulose fibers are obtained.

[0085] The coagulation bath contains 96 g / L of sulfuric acid and 290 g / L of sodium sulfate.

[0086] The web-laying method is web-laying liquid formation, using deionized water at a temperature of 98°C. High-temperature web-laying allows carbon disulfide in the fiber to be evaporated as much as possible, reducing the sulfide content in the fiber.

[0087] The acid pickling, first water rinse, second water rinse, and third water rinse all use deionized water, and the water temperature is controlled at 70℃.

[0088] The solute in the desulfurization bath is sodium hydroxide with a concentration of 4.2 g / L, and the desulfurization bath temperature is 75 °C.

[0089] The acid bath uses acetic acid with a concentration of 6.8 g / L and a temperature of 50°C.

[0090] The concentration of the oil agent in the upper oil bath is 6.5 g / L, and the temperature of the upper oil bath is 57°C.

[0091] The pressing pressure after each of the aforementioned washing or bath treatments is 0.12 MPa; the fiber is dehydrated by pressing with a high-pressure rolling mill before entering the drying process, and the pressing pressure of the high-pressure rolling mill is 0.38 MPa. The moisture regain of the fiber after pressing and dehydration is 130%.

[0092] The drying process uses steam drying, with a steam pressure of 0.55 MPa, a drying temperature of 110°C, and a drying time of 35 minutes.

[0093] This embodiment also provides identifiable and traceable regenerated cellulose fibers prepared using the aforementioned method.

[0094] The identifiable and traceable regenerated cellulose fiber in this embodiment exhibits green fluorescence under ultraviolet light. The fluorescence intensity of the fiber was tested using an FS5 fluorescence spectrometer, with the excitation wavelength controlled at 365.0 nm, the spacing at 2.0 nm, and the test range at 420-540 nm. The fluorescence intensity of the fiber was found to be 1365 a.u., which effectively enables qualitative identification and traceability of the fiber. Inductively coupled plasma mass spectrometry was used to detect terbium in the fiber, and the terbium content was found to be 68.5 ppm, enabling quantitative traceability of the fiber based on its terbium content.

[0095] Furthermore, using the 4N procedure of GB / T8629-2017 "Home Washing and Drying Procedures for Textile Testing" as a standard washing process, the identifiable and traceable regenerated cellulose fiber of this embodiment was continuously washed 50 times. The fluorescence intensity of the fiber was 1351 a.u and the terbium content was 64.9 ppm, which can maintain good washability and durability for a long time, thereby ensuring the long-term qualitative identification and quantitative traceability performance of the fiber.

[0096] Example 3 This embodiment provides a method for preparing identifiable and traceable regenerated cellulose fibers with a specification of 1.67 dtex × 38 mm. The specific steps are as follows: 1. Preparation of a dispersion system for identification and traceability markers (1) Preparation of carbon quantum dot composite terbium acetylacetonate Green fluorescent carbon quantum dots (purchased from Hangzhou Xinqiao Biotechnology Co., Ltd.) were added to a 15wt% terbium acetate aqueous solution, with the mass ratio of green fluorescent carbon quantum dots to terbium acetate controlled at 1:1. The mixture was ultrasonically dispersed for 20 min at an ultrasonic frequency of 40 kHz and a temperature of 50 °C. Then, stirring was started (500 r / min), and the temperature was raised to 65 °C. After maintaining the temperature, acetylacetone was added, and the pH of the mixture was adjusted to 8.5 using an alkaline pH adjuster (sodium hydroxide). The mixture was stirred for 80 min to obtain a dispersion of carbon quantum dots composite terbium acetylacetone. The dispersion was filtered, and the solids were collected. The solids were washed with water and dried to obtain carbon quantum dots composite terbium acetylacetone.

[0097] The molar amount of acetylacetone is 5 times the molar amount of terbium acetate.

[0098] (2) Grinding and dispersing The carbon quantum dot composite terbium acetylacetonate obtained above was added to an organic dispersion, and the mass ratio of carbon quantum dot composite terbium acetylacetonate to organic dispersion was controlled at 2:1. Grinding and dispersion were carried out at a temperature of 25℃ and a grinding speed of 3000 r / min. The particle size was monitored in real time during the grinding process until the particle size of carbon quantum dot composite terbium acetylacetonate D97 = 0.950 μm, thus obtaining an organic dispersion system.

[0099] The organic dispersion used consists of methyl methacrylate and allyl methacrylate, with a mass ratio of methyl methacrylate to allyl methacrylate of 6:1.

[0100] (3) Microcapsule coating The organic dispersion system obtained above was added to a reactor, and then emulsifier (sodium salt of styrene-maleic anhydride copolymer) and deionized water were added. Emulsification and dispersion were carried out under oxygen-free conditions, at a temperature of 45°C and a stirring speed of 2000 r / min, until an emulsion with an organic phase particle size D97 = 1.105 μm was formed. An initiator (benzoyl peroxide) was added to the emulsion, the temperature was raised to 78°C, and held at this temperature. Polymerization was carried out at a stirring speed of 750 r / min. After holding the reaction at this temperature for 180 min, the stirring speed was reduced to 600 r / min, and stirring was continued at a temperature of 40°C for 60 min to obtain a microcapsule dispersion system of modified polymethyl methacrylate coated with carbon quantum dots and terbium acetylacetonate (i.e., the identification and traceability marker dispersion system). The microcapsule particle size D97 in the microcapsule dispersion system was measured to be 1.295 μm.

[0101] In the emulsion, the mass fraction of the organic dispersion system is 50%, the mass fraction of the emulsifier is 7.5%, and the remainder is deionized water.

[0102] The amount of initiator (azobisisobutyronitrile) added is 2.5% of the mass of the organic dispersion system in the emulsion.

[0103] 2. Preparation of blend spinning solution Cellulose pulp with an average degree of polymerization of 650 was used as raw material, and cellulose fiber spinning solution was prepared by viscose preparation process. A modifier was added to the cellulose fiber spinning solution, and the amount of modifier added was controlled to be 2.5% of the methyl cellulose content in the cellulose fiber spinning solution to obtain a modified cellulose fiber spinning solution. Using a pre-spinning injection device, the identification and traceability marker dispersion system (a microcapsule dispersion system of modified polymethyl methacrylate-coated carbon quantum dots and terbium acetylacetonate) obtained above was added to the modified cellulose fiber spinning solution, and the mass of terbium added in the identification and traceability marker dispersion system was controlled to be 80 ppm of the methyl cellulose content in the modified cellulose fiber spinning solution to obtain a blended spinning solution.

[0104] The cellulose fiber spinning solution contained 8.60 wt% cellulose A, 4.50 wt% sodium hydroxide, a falling ball viscosity of 36 s, a maturity of 15 mL (10% NH4Cl), and a sulfur content of 2.15 wt%.

[0105] The denaturant is a mixture of urea and polyethylene glycol PEG-1500; the mass ratio of urea to polyethylene glycol PEG-1500 is 1:2.

[0106] 3. Preparation of identifiable and traceable regenerated cellulose fibers The blended spinning solution obtained above is used for spinning in a coagulation bath at a temperature of 50°C. The nascent filament bundle is drawn to obtain a shaped filament bundle. The shaped filament bundle is then cut, laid into a web, de-acidified, washed in a first water bath, desulfurized in a desulfurization bath, washed in a second water bath, washed in a third water bath, and then oiled in a refining bath before being pressed, dehydrated, and dried to obtain identifiable and traceable regenerated cellulose fibers.

[0107] The coagulation bath contains 100 g / L sulfuric acid and 295 g / L sodium sulfate.

[0108] The web-laying method is web-laying liquid formation, using deionized water as the web-laying liquid at a temperature of 98.5℃; high-temperature web-laying allows carbon disulfide in the fiber to be evaporated as much as possible, reducing the sulfide content in the fiber.

[0109] The acid pickling, first water rinse, second water rinse, and third water rinse all use deionized water, and the water temperature is controlled at 80℃.

[0110] The solute in the desulfurization bath is sodium sulfide with a concentration of 5 g / L, and the temperature of the desulfurization bath is 80℃.

[0111] The acid bath uses acetic acid with a concentration of 8 g / L and a temperature of 40°C.

[0112] The concentration of the oil agent in the upper oil bath is 9 g / L, and the temperature of the upper oil bath is 60℃.

[0113] The pressing pressure after each of the aforementioned washing or bath treatments is 0.15 MPa; the fiber is dehydrated by pressing with a high-pressure rolling mill before entering the drying process, with a pressing pressure of 0.4 MPa, and the moisture regain of the fiber after pressing is 135%.

[0114] The drying process uses steam drying, with a steam pressure of 0.60 MPa, a drying temperature of 120°C, and a drying time of 25 minutes.

[0115] This embodiment also provides identifiable and traceable regenerated cellulose fibers prepared using the aforementioned method.

[0116] The identifiable and traceable regenerated cellulose fiber in this embodiment exhibits green fluorescence under ultraviolet light. The fluorescence intensity of the fiber was tested using an FS5 fluorescence spectrometer, with the excitation wavelength controlled at 365.0 nm, the spacing at 2.0 nm, and the test range at 420-540 nm. The fluorescence intensity of the fiber was found to be 1506 a.u., which effectively enables qualitative identification and traceability of the fiber. Inductively coupled plasma mass spectrometry was used to detect terbium in the fiber, and the terbium content was found to be 75.8 ppm, enabling quantitative traceability of the fiber based on its terbium content.

[0117] Furthermore, using the 4N procedure of GB / T8629-2017 "Home Washing and Drying Procedures for Textile Testing" as a standard washing process, the identifiable and traceable regenerated cellulose fiber of this embodiment was continuously washed 50 times. The fluorescence intensity of the fiber was 1499 a.u and the terbium content was 71.5 ppm, which can maintain good washability and durability for a long time, thereby ensuring the long-term qualitative identification and quantitative traceability performance of the fiber.

[0118] Comparative Example 1 Comparative Example 1 adopts the technical solution of Example 3. The difference between Example 3 and Example 4 is that the addition of green fluorescent carbon quantum dots is omitted in the process of preparing the identification and traceability marker dispersion system; the other processes are exactly the same as those in Example 3.

[0119] Compared with Example 3, although the regenerated cellulose fiber prepared in Comparative Example 1 also exhibited green fluorescence under ultraviolet light, its green fluorescence intensity was significantly reduced. The fluorescence intensity of the fiber obtained by the aforementioned method was 521 a.u, and the terbium content was 56.5 ppm. Meanwhile, after 50 water washes, the fluorescence intensity of the fiber in Comparative Example 1 was 503 a.u, and the terbium content was 51.8 ppm.

[0120] It can be seen that without the addition of green fluorescent carbon quantum dots, Comparative Example 1 cannot enhance the bright green fluorescence of terbium acetylacetonate through green fluorescent carbon quantum dots, resulting in a significant reduction in fluorescence intensity and decreased recognizability.

[0121] Comparative Example 2 Comparative Example 2 adopts the technical solution of Example 3. Compared with Example 3, the changes are as follows: in the process of preparing the identification and traceability marker dispersion system, the microcapsule encapsulation step is omitted, and deionized water is used instead of organic dispersion liquid in the grinding and dispersion process. After grinding and dispersing, the dispersion system is directly used in the preparation of the blend spinning solution. Other processes are exactly the same as in Example 3.

[0122] Compared with Example 3, the regenerated cellulose fiber prepared in Comparative Example 2 exhibited green fluorescence under ultraviolet light. The fluorescence intensity of the fiber was 1252 a.u. and the terbium content was 69.5 ppm, as detected by the aforementioned method. Meanwhile, after 50 water washes, the fluorescence intensity of the fiber in Comparative Example 2 was 1012 a.u. and the terbium content was 55.2 ppm.

[0123] It can be seen that in the process of preparing the identification and traceability marker dispersion system, without microencapsulation, the carbon quantum dot composite terbium acetylacetonate is directly used to prepare the blend spinning solution before spinning. This increases the loss of the identification and traceability marker during the spinning process, and the fluorescence intensity of the prepared fiber decreases significantly. At the same time, the washability and durability of the identification and traceability marker in the fiber are significantly reduced, and it is impossible to maintain the ideal qualitative identification and quantitative traceability performance for a long time.

[0124] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0125] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing identifiable and traceable regenerated cellulose fibers, characterized in that, The process includes the following steps: preparing a dispersion system for identification and traceability markers, preparing a blending spinning solution, and preparing identifiable and traceable regenerated cellulose fibers; The preparation of the identification and traceability marker dispersion system includes the following steps: preparing carbon quantum dot composite terbium acetylacetonate, grinding and dispersing, and microcapsule encapsulation; The method for preparing carbon quantum dot composite terbium acetylacetonate is as follows: green fluorescent carbon quantum dots are added to an aqueous solution of terbium acetate, mixed evenly, heated to 55-65°C, kept at the temperature, and acetylacetonate is added to react. The solid is then separated and collected, washed, and dried to obtain carbon quantum dot composite terbium acetylacetonate. The grinding and dispersion method is as follows: carbon quantum dot composite terbium acetylacetonate is added to an organic dispersion containing methyl methacrylate and allyl methacrylate, and then ground and dispersed until the particle size D97 of the carbon quantum dot composite terbium acetylacetonate is ≤0.950um to obtain an organic dispersion system. The microcapsule encapsulation method involves mixing an organic dispersion system, deionized water, and an emulsifier to prepare an emulsion, and then, in the presence of an initiator, performing a polymerization reaction to microcapsule carbon quantum dot composite terbium acetylacetonate to obtain an identification and traceability marker dispersion system. The method for preparing the blended spinning solution is as follows: the identification and traceability marker dispersion system is mixed with the modified cellulose fiber spinning solution to obtain the blended spinning solution. Identifiable and traceable regenerated cellulose fibers are obtained by spinning the aforementioned blended spinning solution.

2. The method for preparing identifiable and traceable regenerated cellulose fibers according to claim 1, characterized in that, In the preparation of carbon quantum dot composite terbium acetylacetonate, the concentration of terbium acetate in the aqueous solution of terbium acetate is 10-15 wt%. The mass ratio of green fluorescent carbon quantum dots to terbium acetate is 1-2:1; The molar amount of acetylacetone is at least four times the molar amount of terbium acetate.

3. The method for preparing identifiable and traceable regenerated cellulose fibers according to claim 1, characterized in that, In the grinding and dispersion process, the mass ratio of methyl methacrylate to allyl methacrylate in the organic dispersion is 4-6:1; The mass ratio of the carbon quantum dot composite terbium acetylacetonate to the organic dispersion is 1-2:

1.

4. The method for preparing identifiable and traceable regenerated cellulose fiber according to claim 1, characterized in that, In the microcapsule encapsulation, the mass fraction of the organic dispersion system in the emulsion is 40-60%, the mass fraction of the emulsifier is 4.5-7.5%, and the remainder is deionized water; The particle size D97 of the organic phase in the emulsion is ≤1.105μm.

5. The method for preparing identifiable and traceable regenerated cellulose fibers according to claim 1, characterized in that, In the microcapsule encapsulation process, the polymerization reaction temperature is controlled at 60-78℃, the stirring speed is 750-1000 r / min, and the holding time for the polymerization reaction is 120-180 min. The microcapsule particle size D97 in the prepared identification and traceability marker dispersion system is ≤1.295μm.

6. The method for preparing identifiable and traceable regenerated cellulose fibers according to claim 1, characterized in that, In the preparation of the blended spinning solution, the added mass of terbium in the identification and traceability marker dispersion system is controlled to be 60-80 ppm of the content of type A cellulose in the modified cellulose fiber spinning solution. The modified cellulose fiber spinning solution is prepared by mixing cellulose fiber spinning solution with a modifier; the cellulose fiber spinning solution contains 8.60-9.10 wt% methyl cellulose, 4.50-5.10 wt% sodium hydroxide, 36-52 s falling ball viscosity, 15-20 mL 10% NH4Cl ripening degree, and 2.15-2.50 wt% sulfur.

7. The method for preparing identifiable and traceable regenerated cellulose fiber according to claim 6, characterized in that, The amount of the denaturant added is 2.5-4.5% of the methyl cellulose content in the cellulose fiber spinning solution; The denaturant consists of urea and polyethylene glycol PEG-1500.

8. The method for preparing identifiable and traceable regenerated cellulose fibers according to claim 1, characterized in that, The method for preparing identifiable and traceable regenerated cellulose fibers is as follows: the blending spinning solution is spun in a coagulation bath to obtain a shaped filament bundle; the shaped filament bundle is then cut, web-laid, deacidified, washed in a first water bath, desulfurized in a second water bath, washed in an acid bath, washed in a third water bath, and then oiled in an oil bath, followed by pressing, dehydration, and drying to obtain identifiable and traceable regenerated cellulose fibers.

9. The method for preparing identifiable and traceable regenerated cellulose fiber according to claim 8, characterized in that, The coagulation bath contains 90-100 g / L sulfuric acid and 285-295 g / L sodium sulfate; The web is formed using a web-laying liquid with a temperature ≥97℃. The solute in the desulfurization bath is sodium hydroxide or sodium sulfide, with a concentration of 3-5 g / L; The acid bath uses acetic acid or lactic acid with a concentration of 5-8 g / L.

10. An identifiable and traceable regenerated cellulose fiber, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.