Preparation method of functionalized cellulose fiber

Abstract

The invention belongs to the field of functionalized cellulose fibers, and discloses a preparation method of functionalized cellulose fibers, which comprises the following steps: (1) adding a solid functionalized additive into a cellulose dilute solution, and uniformly dispersing to prepare a functionalized cellulose dilute solution A; (2) preparing a high-viscosity cellulose solution B; and (3) mixing the functionalized cellulose dilute solution A and the high-viscosity cellulose solution B to prepare a spinning solution, and spinning to obtain the functionalized cellulose fiber. According to the preparation method disclosed by the invention, the cellulose dilute solution with good fluidity is used for dispersing the solid functional additive, and then the solid functional additive is mixed with the high-viscosity spinning solution, so that the distribution uniformity of the functional additive in the spinning solution can be greatly improved; a series of problems caused by the fact that the additive is added into a system before cellulose is dissolved are avoided, the adding amount of the additive can be more effectively controlled, the adding efficiency is greatly improved, and the uniformity of fibers is more excellent.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functionalized fibers, and particularly relates to a preparation method of functionalized cellulose fibers. BACKGROUND

[0002] With the continuous improvement of living standards and the increasing material needs of the people, the green, healthy, comfortable and other characteristics of civil textiles have gradually become the goal pursued by people. With the increasing development of science and technology, the functionality of textiles is more concerned by people, and therefore, the functionalization of fibers has become a hot topic in the current functional textiles. Cellulose fibers have good comfort, especially with the increasing production of lyocell fibers at home and abroad, this green, comfortable and renewable regenerated cellulose fiber is increasingly entering our daily life, and its functional modification has gradually become the development direction of various enterprises.

[0003] At present, the functional modification of lyocell fibers mostly adopts the method of adding modification to the original solution. However, due to the fact that the viscosity of the cellulose solution prepared by the NMMO solvent system is much higher than that of the traditional viscose spinning solution, it is difficult for the additive to be uniformly distributed in the high-viscosity solution, thereby greatly reducing the functionality of the fiber. Therefore, at present, to realize the modification of lyocell fibers, the functional additives are dispersed and mixed with the NMMO solvent, and then the spinning solution is prepared, so as to improve the dispersity of the functional additives in the fiber, and finally the fiber product with function is prepared. For example:

[0004] Chinese patent application with publication number CN 103541034 A discloses a flame-retardant Lyocell fiber and a preparation method thereof. The preparation method comprises: (1) mixing NMMO solvent with flame retardant at 40-50℃, and stirring until completely dissolved; then mixing cellulose flake with NMMO containing flame retardant, and after standing and swelling, mechanically stirring and heating to vacuum, to prepare flame-retardant spinning dope; (2) after heating the flame-retardant spinning dope, it is sprayed through the spinneret under the pressure of 0.3-0.5 MPa nitrogen, and is formed in the coagulation bath, and after drawing, washing and drying, the flame-retardant Lyocell fiber is obtained.

[0005] Chinese patent application CN 113862807 A discloses a flame-retardant lyocell filament and a preparation method thereof. The preparation method comprises the following steps: S1. dissolving a fiber raw material of the lyocell filament in an aqueous solution of N-methyl-morpholine-N-oxide to obtain a fiber raw material solution, then adding a flame retardant into the fiber raw material solution, and ultrasonic dispersing to obtain a spinning dope, wherein the flame retardant comprises nano hydrotalcite powder; S2. extruding, filtering, spinning, and forming the spinning dope in a coagulation bath to obtain a filament bundle, and then washing, oiling, and drying to obtain the flame-retardant lyocell filament. The viscosity of the cellulose solution in the conventional lyocell process is relatively high, and it is difficult to spin if the viscosity is too low. In this scheme, the flame retardant is directly added to the cellulose solution that can realize spinning, and it is difficult to achieve high dispersion uniformity, thereby causing uneven fiber quality. Chinese patent application CN 116837475 A discloses a preparation method of an antibacterial lyocell fiber, comprising the following steps: dissolution of cellulose quaternary ammonium salt, pre-mixing of cellulose pulp raw material, preparation of spinning dope, and preparation of lyocell antibacterial fiber. The present application first dissolves the cellulose quaternary ammonium salt in the NMMO solvent, and then dissolves the cellulose pulp. This not only does not affect the dissolution of cellulose itself, but also ensures that a uniform, stable, and good-spinnable spinning dope is obtained, which is conducive to the subsequent spinning process. The method of the present application can effectively improve the antibacterial property of lyocell fiber, and can also reduce to a certain extent; the method of the present application adds an antibacterial agent to the spinning dope, so the antibacterial agent is uniformly dispersed in the interior and surface of the fiber, and long-acting antibacterial effect can be achieved.

[0006] The above technologies are all to disperse and mix the functionalized additive with the NMMO solvent, and then prepare the spinning solution, or directly add it to the fiber raw material solution.

[0007] However, it is well known that the lyocell system needs to undergo high temperature and high vacuum environment conditions for dissolving cellulose. Agglomeration and loss of the additive will inevitably occur during the dissolution process of cellulose, which will have a great impact on the preparation cost of the fiber and the realization of the function of the modified fiber, and even affect the operation of the production equipment. In order to meet the functionality of the fiber, the amount of the additive must be increased to balance the loss during the dissolution process, which also leads to the difficulty in accurately controlling the content of the additive in the final cellulose solution, thereby affecting the uniformity of the final fiber product. In addition, the addition of excessive amount of the additive will have a great impact on the formation and orientation process of the aggregate structure of the fiber, which is not conducive to the mechanical properties of the fiber. The viscosity of the cellulose solution in the conventional lyocell process is relatively high, and it is difficult to spin if the viscosity is too low. If the functionalized additive is directly added to the cellulose solution that can realize spinning, it is difficult to achieve high dispersion uniformity, thereby also causing uneven fiber quality.

[0008] Therefore, the present application is proposed. SUMMARY

[0009] The technical problem solved by the present application is to overcome the deficiencies of the prior art and provide a preparation method of functionalized cellulose fibers. The preparation method of the present application utilizes a cellulose dilute solution with good fluidity to disperse solid functionalized additives, and then mixes the solution with a high-viscosity spinning solution, which can greatly improve the uniformity of the distribution of functional additives in the spinning solution.

[0010] To solve the above technical problems, the basic idea of the technical solution of the present application is:

[0011] The present application provides a preparation method of functionalized cellulose fibers, comprising:

[0012] (1) adding solid functionalized additives to a cellulose dilute solution to uniformly disperse and prepare a functionalized cellulose dilute solution A;

[0013] (2) preparing a high-viscosity cellulose solution B;

[0014] (3) mixing the functionalized cellulose dilute solution A and the high-viscosity cellulose solution B to prepare a spinning dope for spinning to obtain functionalized cellulose fibers.

[0015] The present application overcomes the limitations of the prior art in the preparation of functionalized regenerated cellulose fibers, greatly improves the addition efficiency and uniformity of the distribution of functional additives in the fibers, eliminates the production problems and unnecessary fiber manufacturing costs that may be caused by fiber modification, and realizes the efficient preparation of various functionalized cellulose fibers.

[0016] Specifically, the preparation method of the present application utilizes a cellulose dilute solution with good fluidity to disperse solid functionalized additives, and then mixes the solution with a high-viscosity spinning solution, which can greatly improve the uniformity of the distribution of functional additives in the spinning solution.

[0017] Further, in step (1), the viscosity of the cellulose dilute solution is ≤500 Pa·s.

[0018] Further, the cellulose dilute solution can be prepared by using the conventional process in the prior art.

[0019] As a preferred embodiment, the preparation method of the cellulose dilute solution comprises:

[0020] A certain amount of cellulose pulp is added into NMMO solvent, and then dehydrated under a certain temperature and vacuum condition, so that the cellulose is dissolved into the solvent to obtain a cellulose solution with a cellulose concentration of 2-5%.

[0021] In a further aspect, in step (1), the viscosity of the functionalized cellulose dilute solution A is ≤500 Pa·s.

[0022] In a further aspect, in step (1), the functionalized additive is dispersed in the cellulose dilute solution in the form of solid particles, and the particle size R of the solid particles is ≤10 μm.

[0023] In a further aspect, in step (1), the particle size distribution D90 of the functionalized cellulose dilute solution A is ≤1.5R.

[0024] Since the dispersed substance is difficult to reach a monodisperse degree, and in addition, part of the substance may swell when entering the system. In the present application, the particle size distribution D90 of the functionalized cellulose dilute solution A is controlled to be ≤1.5R, and the dispersion is more uniform.

[0025] In a further aspect, in step (1), the solid content of the functionalized additive in the functionalized cellulose dilute solution A is ≤35%.

[0026] In a further aspect, in step (1), the functionalized additive is added into the cellulose dilute solution, and high-speed dispersion is performed by using mechanical stirring, and the rotating speed is 500-1000 rpm.

[0027] In a further aspect, in step (1), the functionalized additive is selected from one or more of flame retardant, antibacterial agent, coloring agent, antistatic agent, far infrared agent, heat conducting agent, anti-radiation agent, fluorescent agent, extinction agent, and microcapsule.

[0028] In a further aspect, in step (2), the cellulose solution B is a cellulose solution of NMMO solvent system, and the solution viscosity η b satisfies 700 Pa·s≤η b ≤2000 Pa·s.

[0029] In the present application, the cellulose solution B should be a solution satisfying the spinnability requirement, and is generally a high-concentration cellulose solution of a new solvent method with high viscosity, and is preferably a cellulose solution of NMMO solvent system, and the solution viscosity is ≤2000 Pa·s.

[0030] Further, the cellulose solution B can be prepared by using the conventional process in the prior art.

[0031] As a preferred embodiment, the preparation method of the cellulose solution B comprises:

[0032] A certain amount of cellulose pulp is added into NMMO solvent, and then dehydrated under a certain temperature and vacuum condition, so that the cellulose is dissolved into the solvent to obtain a cellulose solution with a cellulose concentration of 8-15%.

[0033] In a further aspect, in step (2), the volume ratio of the functionalized cellulose dilute solution A to the high-viscosity cellulose solution B is 1:(3-11) during mixing.

[0034] If the proportion of the functionalized cellulose dilute solution A is too high during mixing, the viscosity of the mixed solution will be too low, which is not conducive to the normal spinning process and will affect the mechanical properties of the fiber. If the proportion of the functionalized cellulose dilute solution A is too low, it is difficult to ensure the dispersion degree of the functionalized additive in the A component, thereby affecting the overall dispersion uniformity after the liquid-liquid mixing in the second step. The volume ratio of the functionalized cellulose dilute solution A to the high-viscosity cellulose solution B is controlled to be 1:(3-11), which can not only maintain the viscosity of the mixed solution, but also ensure the overall dispersion uniformity, which is conducive to improving the fiber properties.

[0035] In a further aspect, in step (2), the functionalized dilute solution A and the cellulose solution B are rapidly and homogeneously mixed in a certain proportion by using an online dynamic mixing device to reach a homogeneous state, and the mixing volume ratio of the functionalized dilute solution A and the cellulose solution B is controlled to be ≤30%. In this way, the non-uniformity of the solid functionalized additive directly mixed with the high-viscosity spinning solution is effectively avoided.

[0036] In a further aspect, the homogeneous solution obtained by mixing the functionalized dilute solution A and the cellulose solution B needs to be transported, filtered, degassed, and extruded into a modified cellulose fiber with the required function.

[0037] In a further aspect, if catalytic additives need to react with cellulose physically or chemically to achieve fiber modification function, a two-step method can be used for treatment. The two-step method comprises: (1) dispersing solid functionalized additives by using a cellulose dilute solution; and (2) adding liquid functionalized additives and / or applying corresponding catalytic conditions during post-treatment.

[0038] In a further aspect, after obtaining the functionalized cellulose fiber, liquid functionalized additives and / or corresponding catalytic conditions are added for post-treatment of the fiber, so that the functionalized additives react with the cellulose physically or chemically.

[0039] Compared with the prior art, the application has the following beneficial effects:

[0040] 1. The preparation method of the functionalized cellulose fiber provided by the application disperses the solid functionalized additive in a cellulose dilute solution as a continuous phase, avoiding direct mixing of the solid additive and the high-viscosity spinning solution; then the solution is rapidly mixed with the high-viscosity cellulose solution by means of dynamic mixing of the solution, greatly improving the uniformity of the distribution of the solid additive in the solution, avoiding a series of problems caused by the addition of the additive into the system before the cellulose is dissolved, more effectively controlling the amount of the additive, greatly improving the addition efficiency, and making the uniformity of the fiber more excellent; meanwhile, the low loss of the additive not only reduces the cost of the fiber modification, but also reduces the possibility of the additive entering the lyocell coagulation bath system, to some extent, reducing the solvent recovery risk and cost caused by the functionalization of the lyocell fiber.

[0041] 2. The preparation method of the application has strong applicability and can be used for the addition of various solid functionalized additives, realizing the preparation of various functionalized lyocell fibers, such as flame-retardant, antibacterial, temperature-regulating, colored fibers, etc.

[0042] 3. The application can use a one-step method to disperse the solid functionalized additive in the cellulose dilute solution; for the catalytic additive and the cellulose that need to physically or chemically react to realize the fiber modification function, a two-step method can be used for processing, in addition to dispersing the solid functionalized additive in the cellulose dilute solution, liquid functionalized additives are added and / or corresponding catalytic conditions are applied during the post-processing; in this way, more functionalized additives can be applied, realizing the preparation of various functionalized lyocell fibers.

[0043] The specific embodiments of the application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0044] The accompanying drawings are part of the present application and serve to provide a further understanding of the present application, the schematic embodiments of the present application and the description thereof serve to explain the present application, but do not constitute an improper limitation on the present application. Obviously, the accompanying drawings described below are only some embodiments, and other drawings can be obtained by those skilled in the art without any creative effort. In the drawings:

[0045] Figure 1 is a flow chart of the preparation method of the functionalized cellulose fiber of the application.

[0046] It should be noted that these drawings and written descriptions are not intended to limit the scope of the concept of the application in any way, but to illustrate the concept of the application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0047] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments will be described clearly and completely below with reference to the drawings in the embodiments of the present application. The following embodiments are used to explain the present application but not to limit the scope of the present application.

[0048] Detection method

[0049] Viscosity: The viscosity of the solution was tested by using a rotary viscometer, and the test conditions were 90°C and a shear rate of 0.4 (1 / s).

[0050] Particle size: The particle size of the solution was tested by using a laser particle size analyzer, and the test temperature was 75°C, and the particle size distribution was obtained.

[0051] Example 1

[0052] As an embodiment of the present application, the present embodiment discloses a solution spinning functionalized fiber preparation method for preparing antibacterial fibers. As shown in the functionalized fiber process flow chart, the two-step method for adding additives is as follows:

[0053] S1, the cellulose pulp is added to the NMMO solvent, and the dehydration stirring is carried out under the conditions of 100°C and 3.5kpa vacuum, to prepare a solution with a cellulose concentration of 1.5%, and the test viscosity is 100Pa·s, which is used as a cellulose dilute solution A.

[0054] S2, the solid component of zinc oxide antibacterial agent with a particle size of 100nm is added to the cellulose dilute solution for high-speed dispersion, so that the solid antibacterial agent is uniformly dispersed in the dilute solution, to prepare a high-dispersion functionalized cellulose dispersion A, and the solid content of the antibacterial agent in the dispersion is 10%, and the D90 of the dispersion A is 0.11μm.

[0055] S3, the cellulose pulp is added to the NMMO solvent, and the dehydration stirring is carried out under the conditions of 100°C and 3.5kpa vacuum, to prepare a solution B with a cellulose concentration of 10%, and the test solution viscosity is 1700Pa·s.

[0056] The dispersion A is mixed with the spinning solution B through a liquid dynamic mixing device, and the volume ratio of A to B is 1:10, to prepare a homogeneous mixed spinning solution, which is conveyed, filtered and defoamed, and extruded into a primary fiber, and the biguanide salt antibacterial agent is added in the fiber refining process for post-treatment and compounding, and the high-temperature catalysis after drying is carried out, to prepare a regenerated cellulose fiber with antibacterial function.

[0057] Results: The spinning process is continuous and stable, the inhibition rate of the fiber on Staphylococcus aureus, Candida albicans and Escherichia coli all reaches 99%, and after 50 times of standard washing, the antibacterial rate of the fiber can still reach more than 90%.

[0058] The mechanical properties of the fiber were tested, and the breaking strength of the fiber was 3.0 CN / dtex, and the breaking elongation was 12.0%.

[0059] Example 2:

[0060] As an embodiment of the application, the embodiment discloses a solution spinning functional fiber preparation method for preparing temperature regulating fibers. As shown in a functional fiber process flow chart, a one-step method is used to add additives, and the specific process is as follows:

[0061] S1, cellulose pulp is added to NMMO solvent, dehydration stirring is performed under the condition of 100 DEG C and 3.5 kpa vacuum, a cellulose solution with a concentration of 4% is prepared, the viscosity is 500 Pa.s, and the cellulose dilute solution A is obtained.

[0062] S2, temperature regulating microcapsules with a particle size of 7 μm and a core material of alkanes are added to the cellulose dilute solution for high-speed dispersion, so that the solid temperature regulating microcapsules are uniformly dispersed in the dilute solution, and a high-dispersion functional cellulose dispersion A is prepared, the solid content of the microcapsules in the dispersion is 15%, and the D90 of the dispersion A is 7.52 μm.

[0063] S3, cellulose pulp is added to NMMO solvent, dehydration stirring is performed under the condition of 100 DEG C and 3.5 kpa vacuum, a cellulose solution B with a concentration of 8.5% is prepared, and the viscosity of the solution is 1000 Pa.s.

[0064] The dispersion A is mixed with the spinning solution B through a liquid dynamic mixing device, the volume ratio of A to B is 1:6, a homogeneous mixed spinning solution is prepared, and after conveying, filtering and defoaming, extrusion molding is performed, and the regenerated cellulose fiber with temperature regulating function is prepared.

[0065] The spinning is continuous and stable, the enthalpy value of the fiber can reach 40 J / g through DSC test, and the enthalpy value of the fiber is maintained above 90% after 50 times of standard washing.

[0066] The mechanical properties of the fiber were tested, and the breaking strength of the fiber was 3.0 CN / dtex, and the breaking elongation was 12.0%.

[0067] Example 3:

[0068] As an embodiment of the application, the embodiment discloses a solution spinning functional fiber preparation method for preparing functional fibers. As shown in a functional fiber process flow chart, a one-step method is used to add multiple additives, and the specific process is as follows:

[0069] S1, add cellulose pulp into NMMO solvent, and carry out dehydration stirring under the condition of 100℃ and 3.5kpa vacuum, to prepare a solution with cellulose concentration of 2.8%, and the viscosity is 300Pa.s, as cellulose dilute solution A.

[0070] S2, add graphene with particle size of 500nm and carbon black dye with particle size of 700nm into cellulose dilute solution, and carry out high-speed dispersion, to make the two kinds of solid additives uniformly dispersed in the dilute solution, to prepare functionalized cellulose dispersion A with high dispersity, the solid content of graphene in the dispersion is 0.5%, the solid content of carbon black dye is 4.5%, and the D90 of dispersion A is 891nm.

[0071] S3, add cellulose pulp into NMMO solvent, and carry out dehydration stirring under the condition of 100℃ and 3.5kpa vacuum, to prepare solution B with cellulose concentration of 7.5%, and the viscosity of the solution is 750Pa.s.

[0072] Mix dispersion A with spinning solution B through liquid dynamic mixing device, the volume ratio of A to B is 1:3, to prepare homogeneous mixed spinning solution, and then carry out conveying, filtration and defoaming, and extrusion molding, to prepare black regenerated cellulose fiber with antistatic function.

[0073] The resistance of the fiber is 5.5×10 5 Ω, the breaking strength of the fiber is 3.2CN / dtex, and the breaking elongation is 10.7%.

[0074] Comparative Example 1

[0075] The difference between Comparative Example 1-1 and Example 1 is that NMMO solvent is used to disperse functional additives, and then cellulose fiber is dissolved, and the specific method comprises:

[0076] S1, add 100nm solid zinc oxide antibacterial agent into NMMO solvent, and carry out high-speed dispersion, to prepare zinc oxide-NMMO dispersion, the solid content of the zinc oxide antibacterial agent is 15%, and the D90 of the dispersion is 0.11μm.

[0077] S2, add a certain amount of cellulose pulp into the dispersion, and carry out dehydration stirring under the condition of 100℃ and 3.5kpa vacuum, to prepare solution with cellulose concentration of 10.1%, and the viscosity of the solution is 1760Pa.s, and the state of the condensate in the vacuum system is observed, and it can be found that part of the antibacterial agent.

[0078] S3, carry out conveying, filtration and defoaming, and extrusion molding, to prepare nascent fiber, add biguanide salt antibacterial agent in the fiber refining process for post-treatment and compounding, and carry out high-temperature catalysis through drying, to prepare regenerated cellulose fiber with antibacterial function.

[0079] Results: The spinning process was stable and continuous, the inhibition rate of the fiber to Staphylococcus aureus, Candida albicans and Escherichia coli reached 95%, and the antibacterial rate of the fiber was 80-85% after 50 times of standard water washing.

[0080] The mechanical properties of the fiber were tested, and the breaking strength of the fiber was 2.7 CN / dtex, and the breaking elongation was 10.2%.

[0081] Compared with Example 1, the antibacterial property and washing resistance of the fiber of Comparative Example Group 1-1 were still decreased under the condition of increasing the addition amount of the antibacterial agent, the mechanical properties of the fiber were decreased, and part of the functionalized additive lost during the dissolution process could be observed in the vacuum system.

[0082] The difference between Comparative Example Group 1-2 and Example 1 is that the functionalized additive is directly added to the spinning dope, and the specific method comprises:

[0083] S1, a certain amount of cellulose pulp is added to NMMO solvent, and dehydration stirring is carried out at 100°C and 3.5kpa vacuum condition to prepare a cellulose solution with a concentration of 10.1%, and the solution viscosity is 1750Pa.s;

[0084] S2, zinc oxide antibacterial agent is added to the cellulose solution of S1, and the solid content of zinc oxide is 6%, and mechanical stirring is carried out, because the viscosity is large, the solid content of the additive is difficult to increase, and high-speed dispersion cannot be carried out, the stirring time is prolonged, and the zinc oxide-cellulose mixed solution is obtained, the viscosity is high and the particle size analysis cannot be carried out;

[0085] S3, the mixed solution is transported, filtered and defoamed, and extruded to form a nascent fiber, a biguanide salt antibacterial agent is added in the fiber refining process for post-treatment and compounding, and high-temperature catalysis is carried out after drying to prepare a regenerated cellulose fiber with antibacterial function.

[0086] The spinning process has the phenomena of broken ends and material points, the filtration pressure increases rapidly, and it is difficult to spin continuously for a long time, the inhibition rate of the fiber to Staphylococcus aureus, Candida albicans and Escherichia coli reaches 87%, and the antibacterial rate of the fiber is 70-80% after 50 times of standard water washing.

[0087] The mechanical properties of the fiber were tested, and the breaking strength of the fiber was 2.5 CN / dtex, and the breaking elongation was 8.3%.

[0088] Compared with Example 1, it is difficult to increase the addition amount of the additive and to uniformly disperse the additive in Comparative Example 1-2, the fiber spinning process is affected, and the antibacterial property and mechanical properties of the fiber are greatly decreased.

[0089] Comparative Example 2

[0090] The comparative example group 2-1 is different from example 2 in that the functionalized additive is dispersed in NMMO solvent to dissolve the cellulose fibers, and the specific method comprises:

[0091] S1, core material of temperature regulating microcapsules with particle size of 7 μm is added to NMMO solvent for high-speed dispersion to prepare microcapsule-NMMO dispersion, microcapsule solid content is 25%, D90 of dispersion A is 7.02 μm;

[0092] S2, quantitative cellulose pulp is added to the dispersion for dehydration stirring under the condition of 100 ℃ and 3.5 kpa vacuum to prepare a solution with cellulose concentration of 8.7% and solution viscosity of 1100 Pa.s, and the state of condensate in the vacuum system is observed;

[0093] S3, after conveying, filtering, defoaming and extrusion molding, the primary fiber is prepared, and after refining and drying, the regenerated cellulose fiber with temperature regulating function is prepared.

[0094] The spinning is continuous and stable, but a small amount of solid material is obtained after the condensate is filtered, which is detected as microcapsules. The enthalpy value of the fiber reaches 30 J / g after DSC test, and the fiber enthalpy value remains above 85% after 50 times of standard washing.

[0095] The mechanical properties of the fiber are tested, and the breaking strength of the fiber is 2.5 CN / dtex, and the elongation at break is 6.7%.

[0096] Compared with example 2, the comparative example group 2-1 can also realize continuous spinning, but a small amount of microcapsules is lost during the preparation of cellulose solution, which leads to the decrease of the temperature regulating performance of the fiber, and the uniformity of the dispersion is destroyed during the dissolution process, which leads to the decrease of the mechanical properties of the fiber.

[0097] The comparative example group 2-2 is different from example 2 in that the functionalized additive is directly added to the spinning stock solution, and the specific method comprises:

[0098] S1, quantitative cellulose pulp is added to NMMO solvent for dehydration stirring under the condition of 100 ℃ and 3.5 kpa vacuum to prepare a solution with cellulose concentration of 8.7% and solution viscosity of 1750 Pa.s;

[0099] S2, core material of temperature regulating microcapsules with particle size of 7 μm is added to the cellulose solution of S1, microcapsule solid content is 5%, and mechanical stirring is carried out, because the viscosity is large, the solid content of the additive is difficult to increase, high-speed dispersion cannot be carried out, and the stirring time is prolonged to obtain a microcapsule-cellulose mixed solution;

[0100] S3, the mixed solution is transported, filtered, defoamed and extruded to form a primary fiber, and the primary fiber is refined and dried to prepare a regenerated cellulose fiber with temperature adjustment function.

[0101] The microcapsules have a large particle size, cannot be monodispersed in the cellulose solution, are difficult to spin, cannot be stably spun, and are difficult to obtain a stable fiber sample.

[0102] Compared with Example 2, it is difficult to use the additive with a large particle size to modify the fiber in Example 2-2.

[0103] Comparative Example 3

[0104] The difference between Comparative Example Group 3-1 and Example 3 is that the functional additive is dispersed in the NMMO solvent, and the cellulose fiber is dissolved again. The specific method comprises:

[0105] S1, graphene with a particle size of 500 nm and carbon black dye with a particle size of 700 nm are added to the NMMO solvent for high-speed dispersion to prepare a uniform dispersion liquid. The solid content of the additive is 15%, the D90 of the dispersion liquid is 715 nm, the solid content of the graphene in the dispersion liquid is 0.8%, and the solid content of the carbon black dye is 6%;

[0106] S2, a certain amount of cellulose pulp is added to the dispersion liquid, and is stirred under the conditions of 100°C and 3.5kpa vacuum to prepare a solution with a cellulose concentration of 7.6%. The viscosity of the solution is 785Pa.s, and the state of the condensate in the vacuum system is observed.

[0107] S3, the mixed solution is transported, filtered, defoamed and extruded to form a primary fiber, and the primary fiber is refined and dried to prepare a regenerated cellulose fiber with temperature adjustment function.

[0108] Results: The spinning process is continuous and stable, the condensate in the vacuum system is black, the additive is partially introduced into the condensation system, the resistance of the fiber is 2.5x10 6 Ω, the breaking strength of the fiber is 3.1CN / dtex, and the breaking elongation is 11.3%.

[0109] Compared with Example 3, the functional material in Comparative Example Group 3-1 can also be stably added and the fiber can be continuously prepared, but the additive is lost during the preparation process, the conductivity of the fiber decreases, and the difference in the mechanical properties of the fiber is small.

[0110] The difference between Comparative Example Group 3-2 and Example 3 is that the functional additive is directly added to the spinning stock solution. The specific method comprises:

[0111] S1, quantitative cellulose pulp is added into NMMO solvent, and dehydration stirring is carried out at 100 DEG C and 3.5 kPa vacuum condition, to prepare a solution with cellulose concentration of 7.6% and solution viscosity of 760 Pa.s;

[0112] S2, graphene with particle size of 500 nm and carbon black dye with particle size of 700 nm are added into the cellulose solution of S1, the solid content of graphene is 0.5%, and the solid content of carbon black dye is 4.5%, and mechanical stirring is carried out, due to the large viscosity, high-speed dispersion cannot be carried out, the stirring time is prolonged, and a graphene-carbon black-cellulose mixed solution is obtained;

[0113] S3, the mixed solution is transported, filtered, defoamed and extruded to form a nascent fiber, and after refining and drying treatment, a black regenerated cellulose fiber with antistatic function is prepared.

[0114] There are a small amount of material points in the spinning process, and the fiber resistance is tested to be 7.0*10 6 Ω, the breaking strength of the fiber is 2.8 CN / dtex, and the breaking elongation is 8.9%.

[0115] Compared with example 3, the additive can be effectively added in comparative example 3-2, but the poor dispersion uniformity leads to high fiber resistance and decreased mechanical strength of the fiber.

[0116] The above only describes the preferred embodiments of the present application, and does not limit the present application in any form, although the present application has been disclosed as above, however, it is not intended to limit the present application, any skilled person in the art can make some changes or modifications to the above-mentioned technical content as equivalent embodiments without departing from the technical solution of the present application, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present application, all still belong to the scope of the present application.

Claims

1. A method for producing a functionalized cellulose fiber, characterized by, The method comprises: (1) adding solid functional additives into a cellulose dilute solution to uniformly disperse, and preparing a functional cellulose dilute solution A; (2) preparing a high-viscosity cellulose solution B; (3) mixing the functional cellulose dilute solution A and the high-viscosity cellulose solution B to prepare a spinning dope for spinning, and obtaining functional cellulose fibers.

2. The method for producing functionalized cellulose fibers according to claim 1, characterized in that, In step (1), the viscosity of the cellulose dilute solution is ≤500 Pa·s.

3. The method of producing functionalized cellulose fibers according to claim 1 or 2, characterized in that, In step (1), the functionalized cellulose dilute solution A has a viscosity η a ≤ 500 Pa s.

4. The method of producing functionalized cellulose fibers according to any one of claims 1 to 3, characterized in that, In step (1), the functional additives are in the form of solid particles dispersed in the cellulose dilute solution, and the particle size of the solid particles is ≤10 μm.

5. The method of producing functionalized cellulose fibers according to any one of claims 1 to 4, characterized in that, In step (1), in the functional cellulose dilute solution A, the particle size distribution D90 is ≤1.5R.

6. The method of producing functionalized cellulose fibers according to any one of claims 1 to 5, characterized in that, In step (1), the solid content of the functional additives in the functional cellulose dilute solution A is ≤35%.

7. The method of producing functionalized cellulose fibers according to any one of claims 1 to 6, characterized in that, In step (1), the functional additives are selected from one or more of antibacterial agents, flame retardants, coloring agents, antistatic agents, far-infrared agents, heat-conducting agents, radiation-proof agents, fluorescent agents, matting agents, and microcapsules.

8. The method of producing functionalized cellulose fibers according to any one of claims 1 to 7, characterized in that, In step (2), the cellulose solution B is a cellulose solution in an NMMO solvent system, and the solution viscosity η b satisfies 700 Pa-s < η b ≤ 2000 Pa-s.

9. The method of producing functionalized cellulose fibers according to any one of claims 1 to 8, characterized in that, In step (2), when mixing, the volume ratio of the functional cellulose dilute solution A to the high-viscosity cellulose solution B is 1:(3-11).

10. The method of producing functionalized cellulose fibers according to any one of claims 1 to 9, characterized in that, After obtaining the functional cellulose fibers, liquid functional additives are added and / or corresponding catalytic conditions are applied for post-treatment of the fibers, so that the functional additives physically or chemically react with the cellulose.

Images