Regenerated cellulose industrial filament spinning solution, preparation method thereof and preparation method of regenerated cellulose industrial filament

Abstract

The invention discloses a regenerated cellulose industrial filament spinning solution, a preparation method thereof and a preparation method of regenerated cellulose industrial filaments. The preparation method of regenerated cellulose industrial filament spinning comprises the following steps: carrying out alkalization treatment on an ionic liquid aqueous solution; preparing cellulose pulp; premixing the alkalized solution and cellulose pulp; preparing a spinning solution; preparing cellulose industrial filaments from the test lines; under pushing of nitrogen and a booster pump, the test line spinning solution is extruded through a filter and a spinning assembly in sequence, and regenerated cellulose hydrogel filaments are obtained through side blowing cooling and coagulating bath forming; and drawing, washing, drying and rolling the gel to obtain a finished product. According to the regenerated cellulose industrial filament spinning stock solution, the preparation method thereof and the preparation method of the regenerated cellulose industrial filament, high-molecular-weight cellulose pulp can be uniformly dissolved with high quality; the problems of cellulose degradation and high energy consumption caused by temperature rise and dissolution time prolonging in the traditional process are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning preparation, and relates to a method for preparing industrial filaments, in particular to a regenerated cellulose industrial filament spinning solution and a preparation method thereof, and a method for preparing regenerated cellulose industrial filaments. Background Art

[0002] With the increase of environmental awareness, people pay more attention to the green and environmental protection of products. The development of industrial filament products is no exception, but currently industrial filaments are still prepared with synthetic fibers such as polyester and nylon. Most of the raw materials of synthetic fibers come from petroleum, which is a non-renewable resource. When the products are scrapped, it is difficult or cannot be degraded by nature for a long time, causing serious environmental pollution. Although it has been reported that waste plastics can be recycled by physical and chemical methods to improve resource utilization, there are problems such as impure extraction and the use of large amounts of chemical reagents. Cellulose, as a natural biopolymer, is widely found in plants and is the most abundant and renewable natural polymer resource on the earth. Cellulose and cellulose product waste can usually be naturally degraded by landfill (no industrial composting is required) without causing environmental pollution. Ionic liquids, as a solvent for cellulose, are liquids at room temperature and have the advantages of stability, non-volatility (safe for operators) and high thermal decomposition temperature. Ionic liquids can be recycled to achieve the reuse of resources, reduce resource waste, and achieve environmental protection.

[0003] The quality of spinning solution, as the precursor of silk, directly affects the performance of silk. Different from civilian staple fibers that have low strength requirements and need to be cut, industrial filament products not only require high strength and high elongation, but also have relatively difficult production processes. In particular, the "broken silk" phenomenon that occurs during the continuous production process will seriously affect the product yield and lead to a sharp increase in costs. The key process to avoid broken silk is to ensure the uniformity of the quality of the spinning solution (avoiding undissolved large-sized pulp) and stability (controllable rheological viscoelasticity). However, the process usually promotes the dissolution of high-polymerization and high-concentration pulp by increasing the temperature and prolonging the dissolution time, which will inevitably lead to the degradation of pulp cellulose. Degraded cellulose will not only reduce the strength of the product, but its detached oligosaccharides (and reducing terminal sugars) will also dissolve into the aqueous coagulation bath, which seriously increases the difficulty of solvent recovery and reduces the quality of the recovered solvent.

[0004] Chinese invention patent CN101085838A discloses a method for continuously preparing cellulose / ionic liquid solution, which uses a screw extruder and its shearing effect to improve the dissolution efficiency of cellulose, reduce the dissolution time of cellulose, and avoid the problem of serious degradation of cellulose during the dissolution process. However, the two temperature zones of the screw extruder are 40-100°C and 80-140°C respectively. When the solution is dissolved at a high temperature of 80-140°C, a large amount of cellulose will be degraded. Although the patent reduces the problem of cellulose degradation due to long dissolution time through the shearing effect of the screw, the dissolution temperature in the patent is as high as 140 degrees Celsius, which cannot avoid the degradation of cellulose under high temperature conditions.

[0005] Chinese invention patent CN101476166A discloses an improved method for preparing cellulose spinning solution using ionic liquid as solvent, which prepares a completely dissolved spinning solution through a two-stage process of swelling and dissolving. Although the spinning solution achieves the effect of complete dissolution, the dissolution conditions are harsh, that is, at a temperature of 80-125°C, it takes 2-8 hours to dissolve, which ultimately leads to a large amount of cellulose degradation in the spinning solution and low viscosity.

[0006] Chinese invention patent CN108004611A discloses a method for preparing solvent cellulose fiber spinning solution using dry pulp, using aqueous NMMO as the main solvent for dissolving cellulose, propyl gallate and hydroxylamine as the heat stabilizer and antioxidant of the solvent, and mixing them together to dissolve cellulose to prepare spinning solution. However, NMMO, as the main component of cellulose fiber solvent, has the disadvantage of high temperature decomposition, which leads to high pipeline pressure after decomposition, causing safety hazards.

[0007] In view of this, there is an urgent need to design a new method for preparing cellulose industrial yarn so as to overcome at least some of the above-mentioned defects of the existing preparation methods. Summary of the invention

[0008] The invention provides a regenerated cellulose industrial filament spinning solution and a preparation method thereof and a preparation method of regenerated cellulose industrial filament, which can prepare a cellulose spinning solution with high dissolution amount and low degradation amount without increasing the dissolution temperature and prolonging the dissolution time.

[0009] To solve the above technical problem, according to one aspect of the present invention, the following technical solution is adopted:

[0010] A method for preparing a regenerated cellulose industrial filament spinning solution, the preparation method comprising:

[0011] Step S1, alkalizing the ionic liquid aqueous solution;

[0012] Step S2, preparing cellulose pulp;

[0013] Step S3, premixing the alkalized solution treated in step S1 and the cellulose pulp;

[0014] Step S4, preparing spinning solution; adding the materials mixed in step S3 into a reaction container, and evacuating the reaction container to a set pressure; stirring at a first stirring speed for a first time to dissolve, and stirring at a second stirring speed for a second time to continue dissolving, to prepare a cellulose low-degradation industrial filament spinning solution.

[0015] As an embodiment of the present invention, the alkalization treatment step of the ionic liquid in step S1 includes: adding deionized water to a high-purity ionic liquid to prepare an ionic liquid aqueous solution containing 10 to 50 wt.% of water; adjusting the pH value of the ionic liquid aqueous solution to 8 to 12 using an alkali; and preparing an alkalized ionic liquid aqueous solution.

[0016] As an embodiment of the present invention, the ionic liquid aqueous solution comprises: at least one of AmimCl, BmimCl, EmimAc, and BmimAc;

[0017] The base comprises at least one of sodium hydroxide, potassium hydroxide, 1,4-diazide bicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU);

[0018] The pulp comprises: cotton pulp or / and wood pulp or / and bamboo pulp or / and recycled pulp with a characteristic viscosity of 300-1800 ml / g.

[0019] As an embodiment of the present invention, the cellulose pulp preparation step S2 includes: testing the pulp using a rapid moisture meter to obtain the moisture content of the pulp; and obtaining paper sheets and / or pulp boards by manual tearing or machine cutting.

[0020] As an embodiment of the present invention, the step S3 of premixing the alkalized solution and cellulose pulp includes: weighing a set mass of absolute dry pulp, the mass of which accounts for 6% to 15% of the total solution mass, tearing the pulp into pulp of a set size, adding pure water to soak it, and then using a screw agitator to treat it to prepare a loose slurry, and then removing water; measuring a set mass of the alkalized ionic liquid aqueous solution of step S1, the mass of which accounts for 85% to 94% of the mass of the regenerated cellulose industrial filament stock solution, adding it to the above-mentioned slurry from which water has been removed, and then using a screw agitator to treat it.

[0021] As an embodiment of the present invention, the spinning solution preparation step S4 comprises:

[0022] Using an oil pump to evacuate the three-necked glass reactor to a pressure of 200-650 Pa, dissolving for 30-60 min at a stirring rate of 25-40 RPM; then, adjusting the stirring rate to 10-20 RPM, and continuing to dissolve for 60-200 min under this condition to prepare a low-degradable industrial filament spinning solution; or,

[0023] After the prepared material is put into the dissolution reactor, the feeding window is closed; the reactor is evacuated with a vacuum pump to make the internal pressure of the reactor 600-1500 Pa, and the material is dissolved for 30-60 minutes at 85-110° C. and a stirring rate of 15-30 Hz; then, the stirring rate is adjusted to 15-25 Hz, and the material is dissolved under this condition for 60-200 minutes to prepare a low-degradable industrial filament spinning solution of cellulose.

[0024] According to another aspect of the present invention, the following technical solution is adopted: a method for preparing regenerated cellulose industrial filaments, the preparation method comprising:

[0025] Step S1, alkalizing the ionic liquid aqueous solution;

[0026] Step S2, preparing cellulose pulp;

[0027] Step S3, premixing the alkalized solution treated in step S1 and the cellulose pulp;

[0028] Step S4, preparing a spinning solution; adding the materials mixed in step S3 into a reaction container, evacuating the reaction container to a set pressure; stirring at a first stirring speed for a first time to dissolve, stirring at a second stirring speed for a second time to continue dissolving, to prepare a spinning solution for industrial filaments with low cellulose degradation;

[0029] Step S5, a test line step for preparing cellulose industrial filaments; the test line spinning solution obtained in step S4 is extruded through a filter and a spinneret assembly under the push of nitrogen and a booster pump, cooled by side blowing, and formed in a coagulation bath to obtain regenerated cellulose hydrogel filaments; the gel is stretched, washed, dried, and rolled into a finished product.

[0030] As an embodiment of the present invention, the step S5 of preparing cellulose industrial filaments on the test line comprises:

[0031] The test line spinning solution obtained in step S4 is extruded through a filter and a spinneret assembly under the push of nitrogen and a booster pump, cooled by side blowing, and formed in a coagulation bath to obtain regenerated cellulose hydrogel yarn; the gel is stretched 1.5-6 times, multi-stage washed and dried; and finally the finished product is rolled up.

[0032] According to another aspect of the present invention, the following technical scheme is adopted: a regenerated cellulose industrial filament spinning stock solution, the regenerated cellulose industrial filament spinning stock solution comprising: 85-94wt% ionic liquid aqueous solution and 6wt%-15wt% pulp;

[0033] The ionic liquid aqueous solution comprises 10 to 50 wt.% of an ionic liquid; the ionic liquid mainly comprises at least one of AmimCl, BmimCl, EmimAc, and BmimAc; an organic base and / or an inorganic base are used to adjust the pH of the ionic liquid aqueous solution to between 8 and 12;

[0034] The pulp comprises: at least one of cotton pulp, wood pulp, bamboo pulp and recycled pulp with a characteristic viscosity of 300-1800 ml / g.

[0035] As an embodiment of the present invention, the organic base and / or inorganic base includes: at least one of sodium hydroxide, potassium hydroxide, 1,4-diazidebicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU).

[0036] The beneficial effects of the present invention are as follows: the regenerated cellulose industrial filament spinning solution and the preparation method thereof as well as the preparation method of regenerated cellulose industrial filament proposed in the present invention can prepare a cellulose spinning solution with high solubility and low degradation without increasing the dissolution temperature and prolonging the dissolution time.

[0037] Through multi-point sampling observations under a polarizing microscope, it was found that the alkalized ionic liquid can dissolve high molecular weight cellulose pulp in a high-quality and uniform manner (no undissolved pulp appears in the field of view); avoiding the cellulose degradation and high energy consumption problems caused by the traditional process of increasing temperature and extending the dissolution time.

[0038] The present invention adjusts the pH of the ionic liquid by adding alkali to the ionic liquid, and prepares a cellulose spinning solution with small degradation amount, strong uniformity and spinnability under the conditions of lower temperature and shorter dissolution time.

[0039] The present invention determines the intrinsic viscosity of dissolved regenerated cellulose and compares it with the zero shear viscosity of spinning solution, and it is known that the alkalized solution system can effectively and significantly reduce the degradation of cellulose (compared with the untreated system, the intrinsic viscosity of regenerated cellulose is increased by 81-123%).

[0040] Compared with the traditional non-alkalized system (and / or inorganic alkali system), the organic alkali system uses very little alkali but has a significant alkalization effect (to achieve the same pH, the amount of organic alkali such as ethylenediamine is only 30% of NaOH), which avoids the equipment corrosion problem caused by excessive accumulation of inorganic alkali during the solvent recovery process.

[0041] The rheological properties of the cellulose spinning solution of the alkalized system can be adjusted with the degree of alkalization, which reduces the single dependence on the equipment capacity (power) and expands the adjustment window of the spinning process (i.e., enhanced spinnability). Table 2 shows that the zero shear viscosity range (1215-4630 Pa·s) and COP coordinate range (storage and loss modulus focus) of the spinning solution of the alkalized system can be adjusted by the degree of alkalization; Figure 2 The results show that the weighted relaxation time spectrum of the alkalized spinning solution maintains a high consistency with the pH.

[0042] The product prepared by the cellulose industrial filament process disclosed in the present invention has a high degree of orientation, a smooth surface, and no obvious skin-core structure ( Figure 4 The filament cross-section SEM) shows that they all have the structural morphology characteristics of traditional lyocell filaments; after the filament tensile test (GBT16604), it is known that its breaking strength and breaking elongation are as high as 3.26cN / detx and 7.61% ( Figure 5 ), which are higher than the strength (2.5-3cN / dtex) and elongation at break (5-6%) of traditional lyocell filaments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a flowchart of a method for preparing a regenerated cellulose industrial filament spinning solution in one embodiment of the present invention.

[0044] Figure 2 The present invention is a flowchart of a method for preparing regenerated cellulose industrial filament spinning in one embodiment of the present invention.

[0045] Figure 3 The figures are the actual product and microscope data in the embodiments of the present invention.

[0046] Figure 4 It is the relaxation time spectrum of the product in the embodiment of the present invention.

[0047] Figure 5 This is a physical picture of product F in one embodiment of the present invention.

[0048] Figure 6 This is a SEM image of a single wire of product F in one embodiment of the present invention.

[0049] Figure 7 This is a stress-strain diagram of product F in one embodiment of the present invention. DETAILED DESCRIPTION

[0050] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0051] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0052] The description in this section is only for several typical embodiments, and the present invention is not limited to the scope of the embodiments. The same or similar prior art means and some technical features in the embodiments are mutually replaced within the scope of the present invention.

[0053] Unless otherwise indicated, implied from the context, or customary in the prior art, all parts and percentages in this application are based on weight, and the test and characterization methods used are all current as of the filing date of this application. Where applicable, the contents of any patent, patent application or publication referred to in this application are fully incorporated herein by reference, and their equivalent patent families are also incorporated by reference, especially the definitions of synthesis techniques, product and processing designs, polymers, comonomers, initiators or catalysts disclosed in these documents in the art. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.

[0054] Numerical ranges in this application are approximate values, so unless otherwise specified, they may include numerical values ​​outside the range. Numerical ranges include all numerical values ​​from the lower limit to the upper limit increased by 1 unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For example, if the recorded component, physical or other properties (such as molecular weight, melt index, etc.) are 100 to 1000, it means that all single values ​​are clearly listed, such as 100, 101, 102, etc., and all sub-ranges, such as 100 to 166, 155 to 170, 198 to 200, etc. For a range containing a numerical value less than 1 or containing a fraction greater than 1 (such as 1.1, 1.5, etc.), 1 unit is appropriately regarded as 0.0001, 0.001, 0.01 or 0.1. For a range containing a single digit less than 10 (such as 1 to 5), 1 unit is usually regarded as 0.1. These are only specific examples of what is intended to be expressed, and all possible combinations of values ​​between the lowest and highest values ​​listed are considered to be clearly recorded in this application. It should also be noted that the terms "first", "second", etc. in this article do not limit the order of precedence, but are only used to distinguish substances with different structures.

[0055] When used with respect to chemical compounds, unless expressly specified otherwise, the singular includes all isomeric forms and vice versa (e.g., "hexane" includes all isomers of hexane, individually or collectively). In addition, nouns using "a," "an," or "the" also include their plural forms unless expressly specified otherwise.

[0056] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any other components, steps or processes, and are irrelevant to whether these other components, steps or processes are disclosed in this application. To eliminate any doubt, unless explicitly stated, all compositions using the terms "comprising", "including", or "having" in this application may include any additional additives, adjuvants or compounds. On the contrary, except for those necessary for operating performance, the term "essentially consisting of..." excludes any other components, steps or processes from the scope of any description of the term below. The term "consisting of..." does not include any components, steps or processes that are not specifically described or listed. Unless explicitly stated, the term "or" refers to the listed individual members or any combination thereof.

[0057] The description of the steps in each embodiment in the specification is only for the convenience of explanation, and the implementation method of the present application is not limited by the order of implementation of the steps.

[0058] The present invention discloses a method for preparing a regenerated cellulose industrial filament spinning solution. Figure 1 FIG. 1 is a flow chart of a method for preparing a regenerated cellulose industrial filament spinning solution in one embodiment of the present invention; please refer to FIG. Figure 1 , the preparation method comprises:

[0059] [Step S1] alkalinizing the ionic liquid aqueous solution;

[0060] In one embodiment of the present invention, the alkalization treatment step of the ionic liquid in step S1 comprises: adding deionized water to a high-purity ionic liquid to prepare an ionic liquid aqueous solution containing 10 to 50 wt.% of water; adjusting the pH value of the ionic liquid aqueous solution to 8 to 12 using an alkali; and preparing an alkalized ionic liquid aqueous solution.

[0061] The ionic liquid aqueous solution comprises: at least one of AmimCl, BmimCl, EmimAc, and BmimAc;

[0062] The base comprises at least one of sodium hydroxide, potassium hydroxide, 1,4-diazide bicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU);

[0063] The pulp comprises: cotton pulp or / and wood pulp or / and bamboo pulp or / and recycled pulp with a characteristic viscosity of 300-1800 ml / g.

[0064] In one embodiment, the mass percentage of the ionic liquid aqueous solution is 85-94%; the mass percentage of the pulp is 6%-15%.

[0065] [Step S2] preparing cellulose pulp;

[0066] In one embodiment of the present invention, the step S2 of preparing cellulose pulp comprises: testing the pulp using a rapid moisture meter to obtain the moisture content of the pulp; and obtaining paper sheets and / or pulp boards by manual tearing or machine cutting.

[0067] [Step S3] Premixing the alkalized solution treated in step S1 and the cellulose pulp;

[0068] In one embodiment of the present invention, the step S3 of premixing the alkalized solution and cellulose pulp includes: weighing a set mass of absolute dry pulp, the mass of which accounts for 6% to 15% of the total solution mass, tearing it into pulp of a set size (such as using a machine or manually tearing it into 10mm to 200mm square pulp), adding pure water to soak (such as adding 30 to 50 kg), and then using a screw agitator to treat it to prepare a loose slurry, and then removing water; measuring a set mass of the alkalized ionic liquid aqueous solution of step S1, the mass of which accounts for 85% to 94% of the mass of the regenerated cellulose industrial filament stock solution, adding it to the above-mentioned slurry from which water has been removed, and then using a screw agitator to treat it to prepare the final material.

[0069] [Step S4] Prepare spinning solution; add the materials mixed in step S3 into a reaction container, and evacuate the reaction container to a set pressure; stir at a first stirring speed for a first time to dissolve, and stir at a second stirring speed for a second time to continue dissolving, to prepare industrial filament spinning solution with low cellulose degradation.

[0070] In one embodiment of the present invention, the step S4 of preparing the spinning solution comprises:

[0071] Using an oil pump to evacuate the three-necked glass reactor to a pressure of 200-650 Pa, dissolving for 30-60 min at a stirring rate of 25-40 RPM; then, adjusting the stirring rate to 10-20 RPM, and continuing to dissolve for 60-200 min under this condition to prepare a low-degradable industrial filament spinning solution; or,

[0072] After the prepared material is put into the dissolution reactor, the feeding window is closed; the reactor is evacuated with a vacuum pump to make the internal pressure of the reactor 600-1500 Pa, and the material is dissolved for 30-60 minutes at 85-110° C. and a stirring rate of 15-30 Hz; then, the stirring rate is adjusted to 15-25 Hz, and the material is dissolved under this condition for 60-200 minutes to prepare a low-degradable industrial filament spinning solution of cellulose.

[0073] The present invention also discloses a regenerated cellulose industrial filament spinning stock solution, which comprises: 85-94wt% ionic liquid aqueous solution and 6wt%-15wt% pulp; the ionic liquid aqueous solution comprises 10-50wt.% ionic liquid; the ionic liquid mainly comprises: at least one of AmimCl, BmimCl, EmimAc, and BmimAc; the pH of the ionic liquid aqueous solution is adjusted between 8 and 12 using an organic base and / or an inorganic base; the pulp comprises: at least one of cotton pulp, wood pulp, bamboo pulp, and recycled pulp with a characteristic viscosity of 300-1800ml / g.

[0074] In one embodiment of the present invention, the organic base and / or inorganic base comprises: at least one of sodium hydroxide, potassium hydroxide, 1,4-diazidebicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU).

[0075] The present invention discloses a method for preparing regenerated cellulose industrial filament spinning. Figure 2 FIG. 1 is a flow chart of a method for preparing regenerated cellulose industrial filament spinning according to an embodiment of the present invention; please refer to FIG. Figure 2 , the preparation method comprises:

[0076] [Step S1] alkalinizing the ionic liquid aqueous solution;

[0077] In one embodiment of the present invention, the alkalization treatment step of the ionic liquid in step S1 comprises: adding deionized water to a high-purity (>99.0%, HPLC) ionic liquid to prepare an ionic liquid aqueous solution containing 10 to 50 wt.% of water; using an alkali (organic base or inorganic base) to adjust the pH of the ionic liquid aqueous solution to 8 to 12 (at 25°C); using a Karl Fischer instrument to test the water content of the ionic liquid solution after the pH adjustment; finally, completing the above steps to prepare an alkalized ionic liquid aqueous solution.

[0078] The ionic liquid aqueous solution may include at least one of AmimCl, BmimCl, EmimAc, and BmimAc; the alkali includes at least one of sodium hydroxide, potassium hydroxide, 1,4-diazide bicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU). The pulp includes cotton pulp or / and wood pulp or / and bamboo pulp or / and recycled pulp with an intrinsic viscosity of 300 to 1800 ml / g.

[0079] [Step S2] preparing cellulose pulp;

[0080] In one embodiment of the present invention, the step S2 of preparing cellulose pulp comprises: testing the pulp using a rapid moisture meter to obtain the moisture content of the pulp; obtaining paper sheets or pulp boards with sizes (length and width of 10*10mm and 200*200mm) by manual tearing or machine cutting in a laboratory or production line.

[0081] [Step S3] Premixing the alkalized solution treated in step S1 and the cellulose pulp;

[0082] In one embodiment of the present invention, the step S3 of premixing the alkalized solution and the cellulose pulp comprises: measuring 85 to 94 g of the pure ionic liquid in step S1, adding it to a 500 mL three-mouth glass reactor, weighing 6 to 15 g of the square chip pulp in step S2, adding it to the three-mouth glass reactor, installing a stirring paddle and other devices to make a final dissolution reactor facility; then, placing the dissolution reactor in an oil bath at a temperature of 85 to 110° C., and stirring at a rate of 10 to 40 RPM for 10 to 30 minutes;

[0083] On the production line: weigh 1000-3000g of absolute dry pulp, tear it into 200*200mm pulp sheets by hand, put it into a 50kg capacity barrel, add 30-50kg of pure water to soak it, then use a screw agitator to treat it to prepare a loose slurry, and then remove the water; measure 11.5kg-34.5kg of the pure ionic liquid in step S1 and add it to the above-mentioned slurry from which water has been removed, then use a screw agitator to treat it to prepare the final material.

[0084] [Step S4] preparing a spinning solution; adding the materials mixed in step S3 into a reaction container, and evacuating the reaction container to a set pressure; stirring at a first stirring speed for a first time to dissolve, and stirring at a second stirring speed for a second time to continue dissolving, to prepare a spinning solution for industrial filaments with low cellulose degradation;

[0085] In one embodiment of the present invention, the step S4 of preparing the spinning solution comprises:

[0086] In the laboratory, an oil pump can be used to evacuate the three-necked glass reactor to a pressure of 200-650 Pa, and the solution can be dissolved for 30-60 min at a stirring rate of 25-40 RPM; then, the stirring rate can be adjusted to 10-20 RPM, and the solution can be continued for 60-200 min under this condition to prepare a low-degradable industrial filament spinning solution of cellulose; or,

[0087] On the production line, the prepared material is fed into the dissolution reactor and the feeding window is closed; the reactor is evacuated with a vacuum pump to a pressure within the reactor of 600 to 1500 Pa, and the material is dissolved for 30 to 60 minutes at 85 to 110° C. and a stirring rate of 15 to 30 Hz; then, the stirring rate is adjusted to 15 to 25 Hz, and the material is dissolved for 60 to 200 minutes under this condition to prepare a low-degradable industrial filament spinning solution of cellulose.

[0088] [Step S5] A test line is used to prepare cellulose industrial filaments; the spinning solution of the test line obtained in step S4 is extruded through a filter and a spinneret assembly under the push of nitrogen and a booster pump, cooled by side blowing, and formed in a coagulation bath to obtain regenerated cellulose hydrogel filaments; the gel is stretched, washed, dried, and rolled into a finished product.

[0089] In one embodiment of the present invention, the step S5 of preparing cellulose industrial filaments by the test line includes: the test line spinning solution obtained in step S4 is pushed through a filter (5-35 μm) and a spinneret assembly (front plate pressure 5-12 MPa) under the push of nitrogen (nitrogen pressure) and a booster pump (50-500 Hz), cooled by side blowing (air volume 50-100 L / min; 20°C; 30-50 RH%), and formed in a coagulation bath (room temperature) to obtain regenerated cellulose hydrogel filaments; the gel is stretched 1.5-6 times, multi-stage washed (30-60°C) and dried (60-90°C); and finally rolled into a finished product.

[0090] The present invention also discloses a method for preparing a regenerated cellulose industrial filament spinning solution, the preparation method comprising:

[0091] Step S1, alkalizing the ionic liquid aqueous solution;

[0092] Step S2, preparing cellulose pulp;

[0093] Step S3, premixing the alkalized solution treated in step S1 and the cellulose pulp;

[0094] Step S4, preparing spinning solution; adding the materials mixed in step S3 into a reaction container, and evacuating the reaction container to a set pressure; stirring at a first stirring speed for a first time to dissolve, and stirring at a second stirring speed for a second time to continue dissolving, to prepare a cellulose low-degradation industrial filament spinning solution.

[0095] Table 1 Intrinsic viscosity of regenerated cellulose in spinning solution (intrinsic viscosity before pulp dissolution is 455 ml / g)

[0096]

[0097]

[0098] (Note: i represents inorganic base; o represents organic base)

[0099] Table 2 Rheological data of products

[0100]

[0101] In the embodiments of the present invention, the solvent is exemplified by BmimCl and AmimCl, and the base is exemplified by sodium hydroxide, 1,4-bis(azide)bicyclo[2,2,2]octane, and ethylenediamine. However, the invention is not limited to the embodiments provided.

[0102] Example 1

[0103] Preparation of ionic liquid solvent: First, weigh 100g of white BmimCl solid and add it to a 250ml beaker. Next, measure 24.56g of deionized water and add it to the beaker to prepare a water-containing BmimCl solution. Then, the solution was tested using a Karl Fischer instrument, and the water content of the solution was 19.72%. The pH of the solution was 7.0.

[0104] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.26%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0105] Preparation of spinning solution: 114.60g of the above-mentioned ionic liquid solvent with a water content of 19.72% was measured and added to a three-mouth glass reactor with a volume of 500mL. 8.63g of square fragment pulp with a water content of 7.26% was weighed and also added to the above three-mouth glass reactor. A stirring paddle and other devices were installed to make the final dissolution reactor facility. Then, the dissolution reactor was placed in an oil bath at a temperature of 100°C and stirred at a rate of 25RPM for 20min. Next, the reactor was evacuated using an oil pump so that the internal pressure was between 200 and 650Pa, and dissolved for 30min at a stirring rate of 25RPM. Then, the stirring rate was adjusted to 15RPM, and the dissolution was continued under this condition for 120min. Finally, after the dissolution experiment reaction was completed, a cellulose industrial filament spinning solution A with a concentration of 8% was prepared. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0106] Example 2

[0107] Preparation of ionic liquid solvent: First, weigh 100g of white BmimCl solid and add it to a 250ml beaker. Then, measure 31.08g of deionized water and add it to the above beaker to prepare a water-containing BmimCl solution. Then, use sodium hydroxide solution to adjust the pH of the BmimCl solution to 8.0. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 23.71%.

[0108] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.46%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0109] Preparation of spinning solution: Measure 120.58g of the above-mentioned ionic liquid solvent with a water content of 23.71%, add it to a three-mouth glass reactor with a volume of 500mL, weigh 8.64g of square fragment pulp with a water content of 7.46%, and also add it to the above three-mouth glass reactor, install devices such as stirring paddles to make the final dissolution reactor facility. Then, place the dissolution reactor in an oil bath at a temperature of 100°C and stir at a rate of 25RPM for 20min. Next, use an oil pump to evacuate the reactor so that the internal pressure is between 200 and 650Pa, and dissolve for 30min at a stirring rate of 25RPM. Then, adjust the stirring rate to 15RPM, and continue to dissolve for 120min under this condition to prepare cellulose industrial filament spinning solution Bi. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0110] Example 3

[0111] Preparation of ionic liquid solvent: First, weigh 100g of white AmimCl solid and add it to a 250ml beaker. Then, measure 24.56g of deionized water and add it to the above beaker to prepare a water-containing AmimCl solution. Then, use 1,4-diazdichlorobicyclo[2,2,2]octane solution to adjust the pH of the AmimCl solution to 8.00. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 19.72%.

[0112] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.46%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0113] Preparation of spinning solution: 114.60g of the above-mentioned ionic liquid solvent with a water content of 19.72% was measured and added to a three-mouth glass reactor with a volume of 500mL. 8.64g of square fragment pulp with a water content of 7.46% was weighed and also added to the above three-mouth glass reactor. A stirring paddle and other devices were installed to make the final dissolution reactor facility. Then, the dissolution reactor was placed in an oil bath at a temperature of 100°C and stirred at a rate of 25RPM for 20min. Next, the reactor was evacuated using an oil pump so that the internal pressure was between 200 and 650Pa, and dissolved for 30min at a stirring rate of 25RPM. Then, the stirring rate was adjusted to 15RPM, and the dissolution continued for 120min under this condition to prepare the cellulose industrial filament spinning solution Bo. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0114] Example 4

[0115] Preparation of ionic liquid solvent: First, weigh 100g of white BmimCl solid and add it to a 250ml beaker. Then, measure 32.19g of deionized water and add it to the above beaker to prepare a water-containing BmimCl solution. Then, use sodium hydroxide solution to adjust the pH of the BmimCl solution to 10.1. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 24.35%.

[0116] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.46%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0117] Preparation of spinning solution: 109.45g of the above-mentioned ionic liquid solvent with a water content of 24.35% was measured and added to a three-necked glass reactor with a volume of 500mL. 7.78g of square fragment pulp with a water content of 7.46% was weighed and also added to the above three-necked glass reactor. A stirring paddle and other devices were installed to make the final dissolution reactor facility. Then, the dissolution reactor was placed in an oil bath at a temperature of 100°C and stirred at a rate of 25RPM for 20min. Next, an oil pump was used to evacuate the reactor so that the internal pressure was between 200 and 650Pa, and the solution was dissolved at a stirring rate of 25RPM for 30min. Then, the stirring rate was adjusted to 15RPM, and the solution was continued for 120min under this condition to prepare the industrial filament spinning solution Ci of cellulose. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0118] Example 5

[0119] Preparation of ionic liquid solvent: First, weigh 100g of white AmimCl solid and add it to a 250ml beaker. Then, measure 25.08g of deionized water and add it to the above beaker to prepare an aqueous AmimCl solution. Then, use ethylenediamine solution to adjust the pH of the AmimCl solution to 10.0. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 20.05%.

[0120] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.61%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0121] Preparation of spinning solution: 115.07g of the above-mentioned ionic liquid solvent with a water content of 20.05% was measured and added to a three-mouth glass reactor with a volume of 500mL. 8.66g of square chip pulp with a water content of 7.61% was weighed and also added to the above three-mouth glass reactor. A stirring paddle and other devices were installed to make the final dissolution reactor facility. Then, the dissolution reactor was placed in an oil bath at a temperature of 100°C and stirred at a rate of 25RPM for 20min. Next, an oil pump was used to evacuate the reactor so that the internal pressure was between 200 and 650Pa, and the solution was dissolved at a stirring rate of 25RPM for 30min. Then, the stirring rate was adjusted to 15RPM, and the solution was continued for 120min under this condition to prepare the industrial filament spinning solution Co of cellulose. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0122] Example 6

[0123] Preparation of ionic liquid solvent: First, weigh 100g of white BmimCl solid and add it to a 250ml beaker. Then, measure 24.56g of deionized water and add it to the above beaker to prepare a water-containing BmimCl solution. Then, use 1,4-dichlorobicyclo[2,2,2]octane solution to adjust the pH of the BmimCl solution to 10.7. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 19.72%.

[0124] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.61%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0125] Preparation of spinning solution: 114.60g of the above-mentioned ionic liquid solvent with a water content of 19.72% was measured and added to a three-mouth glass reactor with a volume of 500mL. 8.66g of square fragment pulp with a water content of 7.61% was weighed and also added to the above three-mouth glass reactor. A stirring paddle and other devices were installed to make the final dissolution reactor facility. Then, the dissolution reactor was placed in an oil bath at a temperature of 100°C and stirred at a rate of 25RPM for 20min. Next, an oil pump was used to evacuate the reactor so that the internal pressure was between 200 and 650Pa, and the solution was dissolved at a stirring rate of 25RPM for 30min. Then, the stirring rate was adjusted to 15RPM, and the solution was continued for 120min under this condition to prepare the industrial filament spinning solution Do of cellulose. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0126] Example 7

[0127] Preparation of ionic liquid solvent: First, weigh 100g of white BmimCl solid and add it to a 250ml beaker. Then, measure 29.08g of deionized water and add it to the above beaker to prepare a water-containing BmimCl solution. Then, use sodium hydroxide solution to adjust the pH of the BmimCl solution to 12.0. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 22.53%.

[0128] Preparation of cellulose pulp: First, the pulp with an intrinsic viscosity of 455 ml / g was tested using a rapid moisture meter, and its moisture content was 7.46%. Then, the pulp was torn into square pieces with a length and width of about 10 mm*10 mm.

[0129] Preparation of spinning solution: 118.75g of the above-mentioned ionic liquid solvent with a water content of 22.53% was measured and added to a three-mouth glass reactor with a volume of 500mL. 8.64g of square fragment pulp with a water content of 7.46% was weighed and also added to the above three-mouth glass reactor. A stirring paddle and other devices were installed to make the final dissolution reactor facility. Then, the dissolution reactor was placed in an oil bath at a temperature of 100°C and stirred at a rate of 25RPM for 20min. Next, an oil pump was used to evacuate the reactor so that the internal pressure was between 200 and 650Pa, and the solution was dissolved at a stirring rate of 25RPM for 30min. Then, the stirring rate was adjusted to 15RPM, and the solution was continued for 120min under this condition to prepare the industrial filament spinning solution Ei of cellulose. The spinning solution was tested using an Ubbelohde viscometer and a rotational rheometer. The test results are shown in Tables 1, 2, Figure 3 and Figure 4 shown.

[0130] Example 8

[0131] Preparation of ionic liquid solvent: First, weigh 11.5 kg of white BmimCl solid and add it to a 50 kg bucket. Then, measure 3.24 kg of deionized water and add it to the bucket to prepare a water-containing BmimCl solution. Then, use sodium hydroxide solution to adjust the pH of the BmimCl solution to 9.5. Then, use a Karl Fischer instrument to test the solution, and the water content of the solution is 22.00%.

[0132] Preparation of cellulose pulp: Weigh 1000-3000g of absolute dry pulp, tear it into 200*200mm pulp sheets by hand, put it into a 50kg capacity barrel, add 30-50kg pure water to soak it, then use a screw agitator to process it to prepare loose slurry, and then remove moisture.

[0133] Preparation of spinning solution: Weigh 14.74 kg of the BmimCl solution prepared above and add it to the above-mentioned dewatered slurry, then use a screw agitator to process it to prepare the final material. After the material is put into the dissolution reactor, close the feeding window. Use a vacuum pump to evacuate the reactor so that the internal pressure is 600-1500 Pa, and dissolve it for 60 minutes at 100°C and a stirring rate of 25Hz. Then, adjust the stirring rate to 20Hz, and continue to dissolve for 120 minutes under this condition to prepare a low-degradation industrial filament spinning solution for cellulose.

[0134] Preparation of cellulose industrial filaments: Use 0.5Mpa N2 pressure to deliver spinning solution. The spinning solution is filtered through a 20μm filter screen, and reaches the spinneret through a metering pump and a booster pump in the melt pipeline. It is spun through a spinneret with a pore size of 0.06mm and a number of 1000 holes. After the spinning solution flows out of the spinneret, it passes through an air gap. The temperature of the air gap is controlled to be 25℃, the relative humidity is RH40%, and the length is 15mm. The slow cooling air flow rate is controlled to be 80L / min and the temperature is 25℃. Regenerated cellulose is achieved in deionized water, and the regenerated cellulose is stretched with a draft ratio of 1.8 times. The roller speed is 35m / min. The regenerated cellulose after drawing is then washed with water at a temperature of 40℃ for multiple stages, and then dried with a pair of rollers at a temperature of 80℃ to obtain a regenerated cellulose fiber industrial filament F with a linear density of 1860dtex. Its physical picture, SEM and fracture strength and elongation test results (GBT16604) are as follows Figures 5 to 7 shown.

[0135] In summary, the regenerated cellulose industrial filament spinning solution and its preparation method and the regenerated cellulose industrial filament preparation method proposed in the present invention can prepare cellulose spinning solution with high dissolution amount and low degradation amount without increasing the dissolution temperature and prolonging the dissolution time.

[0136] Through multi-point sampling observations under a polarizing microscope, it was found that the alkalized ionic liquid can dissolve high molecular weight cellulose pulp in a high-quality and uniform manner (no undissolved pulp appears in the field of view); avoiding the cellulose degradation and high energy consumption problems caused by the traditional process of increasing temperature and extending the dissolution time.

[0137] The present invention adjusts the pH of the ionic liquid by adding alkali to the ionic liquid, and prepares a cellulose spinning solution with small degradation amount, strong uniformity and spinnability under the conditions of lower temperature and shorter dissolution time.

[0138] The present invention determines the intrinsic viscosity of dissolved regenerated cellulose and compares it with the zero shear viscosity of spinning solution, and it is known that the alkalized solution system can effectively and significantly reduce the degradation of cellulose (compared with the untreated system, the intrinsic viscosity of regenerated cellulose is increased by 81-123%).

[0139] Compared with the traditional non-alkalized system (and / or inorganic alkali system), the organic alkali system uses very little alkali but has a significant alkalization effect (to achieve the same pH, the amount of organic alkali such as ethylenediamine is only 30% of NaOH), which avoids the equipment corrosion problem caused by excessive accumulation of inorganic alkali during the solvent recovery process.

[0140] The rheological properties of the cellulose spinning solution of the alkalized system can be adjusted with the degree of alkalization, which reduces the single dependence on the equipment capacity (power) and expands the adjustment window of the spinning process (i.e., enhanced spinnability). Table 2 shows that the zero shear viscosity range (1215-4630 Pa·s) and COP coordinate range (storage and loss modulus focus) of the spinning solution of the alkalized system can be adjusted by the degree of alkalization; Figure 2 The results show that the weighted relaxation time spectrum of the alkalized spinning solution maintains a high consistency with the pH.

[0141] The product prepared by the cellulose industrial filament process disclosed in the present invention has a high degree of orientation, a smooth surface, and no obvious skin-core structure ( Figure 4 The filament cross-section SEM) shows that they all have the structural morphology characteristics of traditional lyocell filaments; after the filament tensile test (GBT16604), it is known that its breaking strength and breaking elongation are as high as 3.26cN / detx and 7.61% ( Figure 5 ), which are higher than the strength (2.5-3cN / dtex) and elongation at break (5-6%) of traditional lyocell filaments.

[0142] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0143] The description and application of the present invention here are illustrative, and it is not intended to limit the scope of the present invention to the above-mentioned embodiments. The effects or advantages involved in the embodiments may not be embodied in the embodiments due to interference from various factors, and the description of the effects or advantages is not used to limit the embodiments. The deformation and change of the embodiments disclosed here are possible, and the replacement of the embodiments and the various equivalent parts are well known to those of ordinary skill in the art. It should be clear to those skilled in the art that the present invention can be implemented in other forms, structures, arrangements, proportions, and with other components, materials and parts without departing from the spirit or essential features of the present invention. Other deformations and changes can be made to the embodiments disclosed here without departing from the scope and spirit of the present invention.

Claims

1. A method for preparing a spinning solution for regenerated cellulose industrial filament spinning, characterized in that: The preparation method comprises: Step S1, alkalizing the ionic liquid aqueous solution; Step S2, preparing cellulose pulp; Step S3, premixing the alkalized solution treated in step S1 and the cellulose pulp; Step S4, preparing spinning solution; adding the materials mixed in step S3 into a reaction container, and evacuating the reaction container to a set pressure; stirring at a first stirring speed for a first time to dissolve, and stirring at a second stirring speed for a second time to continue dissolving, to prepare a cellulose low-degradation industrial filament spinning solution.

2. The method for preparing the regenerated cellulose industrial filament spinning solution according to claim 1, characterized in that: The step S1 of alkalizing the ionic liquid comprises: adding deionized water to a high-purity ionic liquid to prepare an ionic liquid aqueous solution containing 10 to 50 wt.% of water; adjusting the pH value of the ionic liquid aqueous solution to 8 to 12 using an alkali; and preparing an alkalized ionic liquid aqueous solution.

3. The method for preparing the regenerated cellulose industrial filament spinning solution according to claim 2, characterized in that: The ionic liquid aqueous solution comprises: at least one of AmimCl, BmimCl, EmimAc, and BmimAc; The base comprises at least one of sodium hydroxide, potassium hydroxide, 1,4-diazide bicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU); The pulp comprises: cotton pulp or / and wood pulp or / and bamboo pulp or / and recycled pulp with a characteristic viscosity of 300-1800 ml / g.

4. The method for preparing the regenerated cellulose industrial filament spinning solution according to claim 1, characterized in that: The step S2 of preparing cellulose pulp comprises: testing the pulp with a rapid moisture meter to obtain the moisture content of the pulp; and obtaining paper sheets and / or pulp boards by manual tearing or machine cutting.

5. The method for preparing the regenerated cellulose industrial filament spinning solution according to claim 1, characterized in that: The step S3 of premixing the alkalized solution and cellulose pulp comprises: weighing a set mass of absolute dry pulp, the mass of which accounts for 6% to 15% of the total solution mass, tearing the pulp into pieces of a set size, adding pure water to soak it, then treating it with a screw agitator to prepare a loose slurry, and then removing water; measuring a set mass of the alkalized ionic liquid aqueous solution of step S1, the mass of which accounts for 85% to 94% of the mass of the regenerated cellulose industrial filament stock solution, adding it to the above-mentioned slurry from which water has been removed, and then treating it with a screw agitator.

6. The method for preparing the regenerated cellulose industrial filament stock solution according to claim 1, characterized in that: The step S4 of preparing the spinning solution comprises: Using an oil pump to evacuate the three-necked glass reactor to a pressure of 200-650 Pa, dissolving for 30-60 min at a stirring rate of 25-40 RPM; then, adjusting the stirring rate to 10-20 RPM, and continuing to dissolve for 60-200 min under this condition to prepare a low-degradable industrial filament spinning solution; or, After the prepared material is put into the dissolution reactor, the feeding window is closed; the reactor is evacuated with a vacuum pump to make the internal pressure of the reactor 600-1500 Pa, and the material is dissolved for 30-60 minutes at 85-110° C. and a stirring rate of 15-30 Hz; then, the stirring rate is adjusted to 15-25 Hz, and the material is dissolved under this condition for 60-200 minutes to prepare a low-degradable industrial filament spinning solution of cellulose.

7. A method for preparing regenerated cellulose industrial filaments, characterized in that: The preparation method comprises: Step S1, alkalizing the ionic liquid aqueous solution; Step S2, preparing cellulose pulp; Step S3, premixing the alkalized solution treated in step S1 and the cellulose pulp; Step S4, preparing a spinning solution; adding the materials mixed in step S3 into a reaction container, evacuating the reaction container to a set pressure; stirring at a first stirring speed for a first time to dissolve, stirring at a second stirring speed for a second time to continue dissolving, to prepare a spinning solution for industrial filaments with low cellulose degradation; Step S5, a test line step for preparing cellulose industrial filaments; the test line spinning solution obtained in step S4 is extruded through a filter and a spinneret assembly under the push of nitrogen and a booster pump, cooled by side blowing, and formed in a coagulation bath to obtain regenerated cellulose hydrogel filaments; the gel is stretched, washed, dried, and rolled into a finished product.

8. The method for preparing regenerated cellulose industrial filaments according to claim 7, characterized in that: The step S5 of preparing cellulose industrial filaments on the test line comprises: The test line spinning solution obtained in step S4 is extruded through a filter and a spinneret assembly under the push of nitrogen and a booster pump, cooled by side blowing, and formed in a coagulation bath to obtain regenerated cellulose hydrogel yarn; the gel is stretched 1.5-6 times, multi-stage washed and dried; and finally the finished product is rolled up.

9. A regenerated cellulose industrial filament spinning solution, characterized in that: The regenerated cellulose industrial filament spinning solution comprises: 85-94 wt% of an ionic liquid aqueous solution and 6-15 wt% of pulp; The ionic liquid aqueous solution comprises 10 to 50 wt.% of an ionic liquid; the ionic liquid mainly comprises at least one of AmimCl, BmimCl, EmimAc, and BmimAc; an organic base and / or an inorganic base are used to adjust the pH of the ionic liquid aqueous solution to between 8 and 12; The pulp comprises: at least one of cotton pulp, wood pulp, bamboo pulp and recycled pulp with a characteristic viscosity of 300-1800 ml / g.

10. The regenerated cellulose industrial filament spinning solution according to claim 9, characterized in that: The organic base and / or inorganic base includes at least one of sodium hydroxide, potassium hydroxide, 1,4-diazidebicyclo[2,2,2]octane, ethylenediamine, triethylamine (TEA), tetramethylguanidine (TMG), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicycloundec-7-ene (DBU).

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