Tourmaline modified lyocell fiber with high efficiency negative ion releasing function and preparation and application thereof

Abstract

The application relates to a tourmaline modified Lyocell fiber with a high-efficiency negative ion release function and preparation and application thereof. A tourmaline powder / NMMO dispersion liquid with uniform distribution and stability is prepared in a wet ball milling mode by taking NMMO aqueous solution as a dispersion medium for spinning the Lyocell fiber, and the whole process is simple and environment-friendly in combination with a conventional Lyocell process. The prepared tourmaline modified Lyocell fiber has the high-efficiency negative ion release function.

Description

Technical Field

[0001] This invention belongs to the field of functional fiber technology, and specifically relates to a tourmaline-modified Lyocell fiber with efficient negative ion release function, its preparation and application. Background Technology

[0002] Negative ions are negatively charged oxygen ions in the air, often referred to as "air vitamins." They possess excellent health benefits, purifying the air, inhibiting bacteria and reducing dust, regulating the nervous system, soothing the mind and body, improving sleep, promoting metabolism, strengthening cardiopulmonary function and immunity, and effectively improving sub-health issues. In recent years, with the continuous improvement of people's living standards, the demand for fibers and textiles with negative ion function has continued to grow. Currently, negative ion functional fibers are mostly produced using a blending modification process, adding tourmaline powder, which has negative ion release capabilities, to give the fibers better negative ion release properties.

[0003] In recent years, numerous patents have been reported on the preparation of modified fibers with negative ion release functions by combining tourmaline with different polymer matrices. CN12905804 discloses a negative ion polyester fiber and its preparation method; CN 120649189 discloses a negative ion-coated synthetic fiber and its preparation method; CN 119663473 discloses a method for preparing melt-spun negative ion polyamide fiber; and CN117535818 discloses a fiber with highly efficient negative ion release function and its preparation method. These patents primarily use tourmaline powder as an additive and polyester or polyamide as the polymer matrix, prepared through melt spinning. Compared to these petroleum-based polymers, cellulose is abundant and renewable. In today's society where petroleum resources are increasingly scarce, developing cellulose fibers with highly efficient negative ion release functions using non-petroleum raw materials is of great significance for sustainable development.

[0004] Lyocell fiber is a novel cellulose fiber produced by directly dissolving cellulose pulp in the organic solvent N-methylmorpholine-N-oxide (NMMO) and spinning it using a dry-jet wet spinning method. It boasts significant advantages over other cellulose fibers, including a simple production process, an environmentally friendly solvent system, biodegradability, and ease of in-situ addition of functional components. In recent years, Lyocell has experienced rapid development, demonstrating enormous application potential in the field of functionalized modified fibers. Therefore, developing tourmaline-modified Lyocell fibers with negative ion release capabilities based on the Lyocell process holds promising prospects.

[0005] However, tourmaline powder has a large surface energy and is prone to agglomeration. When preparing tourmaline-modified Lyocell fibers using the blending method, it is difficult to prepare a spinning solution with a uniform distribution of tourmaline powder. During the spinning process, broken or fuzzy fibers are prone to occur. At the same time, the tourmaline particles in the prepared Lyocell fibers are severely aggregated, making it difficult to fully utilize the negative ion release performance of tourmaline powder. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a tourmaline-modified Lyocell fiber with efficient negative ion release function, as well as its preparation and application.

[0007] This invention provides a method for preparing tourmaline-modified Lyocell fibers, comprising:

[0008] (1) Mix tourmaline and dispersion medium, disperse by ultrasonication and then grind to obtain tourmaline dispersion;

[0009] (2) Mix tourmaline dispersion, cellulose pulp and NMMO solution, let stand to swell, and then mechanically stir under vacuum to obtain spinning solution. After spinning, tourmaline modified Lyocell fiber is obtained.

[0010] Preferably, the dispersion medium in step (1) is an aqueous solution of NMMO with a mass percentage concentration of 50-74%.

[0011] Preferably, the grinding time in step (1) is 10 min to 2 h, and the ball milling speed is 200 to 1000 rpm.

[0012] Preferably, the mass percentage concentration of the tourmaline dispersion in step (1) is 10-30%.

[0013] Preferably, the spinning in step (2) is Lyocell fiber spinning process.

[0014] The spinning process parameters for Lyocell fibers are as follows: the spinning solution at 90-120 °C is metered by a metering pump under a nitrogen pressure of 0.2-0.6 MPa, extruded from the spinneret, passed through an air section of 5-200 mm, and then entered a coagulation bath with a mass percentage concentration of 0-20% NMMO. The solution is then solidified and shaped in a coagulation bath at 5-30 °C and wound at a speed of 50-200 m / min.

[0015] Preferably, the mass content of tourmaline in the tourmaline-modified Lyocell fiber in step (2) is 5-40%.

[0016] This invention provides a tourmaline-modified Lyocell fiber prepared by the method described above.

[0017] This invention provides an application of the tourmaline-modified Lyocell fiber in the fields of functional fibers, apparel textiles, home textiles, and industrial textiles, such as functional fibers, high-end clothing, home textiles, automotive interiors, environmental filtration, and building materials decoration.

[0018] NMMO stands for N-methylmorpholine-N-oxide.

[0019] This invention uses NMMO aqueous solution, the solvent for spinning Lyocell fibers, as the dispersion medium. A uniformly distributed and stable tourmaline powder / NMMO dispersion is prepared by wet ball milling. Combined with conventional Lyocell processes, the whole process is simple and environmentally friendly. The resulting tourmaline-modified Lyocell fibers have a highly efficient negative ion release function.

[0020] Beneficial effects

[0021] (1) The present invention uses NMMO aqueous solution, the solvent for spinning Lyocell fibers, as the dispersion medium and adopts wet ball milling. Without the use of any coupling agent or dispersant, tourmaline powder can be uniformly dispersed in NMMO solvent, and the obtained tourmaline dispersion has good dispersion stability.

[0022] (2) The present invention uses wet ball milling to grind tourmaline powder. After ball milling, the particle size of tourmaline powder is reduced, and the refined tourmaline powder has more micro electric fields, which is beneficial to improving its negative ion release function.

[0023] (3) The tourmaline used in this invention is a natural mineral with abundant reserves. The cellulose pulp raw materials used are widely available, such as bamboo pulp, wood pulp, and cotton pulp. The entire preparation process is simple and efficient, the solvent can be recycled, and no pollutants are generated during the processing, which has green and environmentally friendly characteristics.

[0024] (4) The tourmaline-modified Lyocell fiber prepared by the present invention has a high-efficiency negative ion release function, which can purify the air and promote human health. Detailed Implementation

[0025] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0026] The Lyocell fiber spinning process used in Examples 1-4 and Comparative Example 1 is as follows: the spinning solution at 100 °C is metered by a metering pump under a nitrogen pressure of 0.4 MPa, extruded from the spinneret, passes through a 100 mm air section, and enters a coagulation bath with a NMMO mass percentage concentration of 10%. It is then solidified and shaped in a coagulation bath at 25 °C and wound at a speed of 100 m / min.

[0027] Comparative Example 1

[0028] Tourmaline powder was mixed with water and ultrasonically treated for 20 min to obtain a 10% tourmaline / water pre-dispersion. The tourmaline / water pre-dispersion was then ground using a wet ball mill at 800 rpm for 2 h. Although the tourmaline powder particles were refined, the tourmaline powder settled quickly in water and agglomerated at the bottom, making it difficult to obtain a uniformly dispersed tourmaline powder aqueous solution. The ball-milled tourmaline aqueous solution was mixed with cellulose pulp and NMMO solution, allowed to swell, and then mechanically stirred under vacuum. The resulting 10% tourmaline-modified Lyocell spinning solution showed severe tourmaline powder agglomeration. When using conventional Lyocell fiber spinning processes, it easily clogged the spinneret, causing fiber breakage and poor spinnability.

[0029] Example 1

[0030] Tourmaline powder was mixed with a 74% NMMO aqueous solution and ultrasonically treated for 10 min to obtain a 10% tourmaline / NMMO pre-dispersion. The tourmaline / NMMO pre-dispersion was then wet-milled at 200 rpm for 2 h to obtain a uniformly dispersed tourmaline powder / NMMO solution. The ball-milled tourmaline dispersion was mixed with cellulose pulp and NMMO solution, allowed to swell, and then mechanically stirred under vacuum to prepare a tourmaline-modified Lyocell spinning solution. Using conventional Lyocell fiber spinning technology, Lyocell fibers with a tourmaline content of 5% and an ion release of 2800 ions / cm³ were obtained. 3 .

[0031] Example 2

[0032] Tourmaline powder was mixed with a 50% NMMO aqueous solution and ultrasonically treated for 30 min to obtain a 20% tourmaline / NMMO pre-dispersion. The tourmaline / NMMO pre-dispersion was then wet-milled at 1000 rpm for 10 min to obtain a uniformly dispersed tourmaline powder / NMMO solution. The milled tourmaline dispersion was mixed with cellulose pulp and NMMO solution, allowed to swell, and then mechanically stirred under vacuum to prepare a tourmaline-modified Lyocell spinning solution. Using conventional Lyocell fiber spinning technology, Lyocell fibers with a tourmaline content of 10% were obtained, exhibiting a negative ion release of 5600 ions / cm³. 3 .

[0033] Example 3

[0034] Tourmaline powder was mixed with a 50% NMMO aqueous solution and ultrasonically treated for 20 min to obtain a 30% tourmaline / NMMO pre-dispersion. The tourmaline / NMMO pre-dispersion was then wet-milled at 550 rpm for 1.5 h to obtain a uniformly dispersed tourmaline powder / NMMO solution. The ball-milled tourmaline dispersion was mixed with cellulose pulp and NMMO solution, allowed to swell, and then mechanically stirred under vacuum to prepare a tourmaline-modified Lyocell spinning solution. Using conventional Lyocell fiber spinning technology, Lyocell fibers with a tourmaline content of 40% were obtained, exhibiting a negative ion release of 8200 ions / cm³. 3 .

[0035] Example 4

[0036] Tourmaline powder was mixed with a 65% NMMO aqueous solution and ultrasonically treated for 20 min to obtain a 20% tourmaline / NMMO pre-dispersion. The tourmaline / NMMO pre-dispersion was then wet-milled at 400 rpm for 1 h to obtain a uniformly dispersed tourmaline powder / NMMO solution. The ball-milled tourmaline dispersion was mixed with cellulose pulp and NMMO solution, allowed to swell, and then mechanically stirred under vacuum to prepare a tourmaline-modified Lyocell spinning solution. Using conventional Lyocell fiber spinning technology, Lyocell fibers with a tourmaline content of 30% were obtained, exhibiting a negative ion release of 6450 ions / cm³. 3 .

Claims

1. A method for preparing tourmaline-modified Lyocell fibers, comprising: (1) Mix tourmaline and dispersion medium, disperse by ultrasonication and then grind to obtain tourmaline dispersion; (2) Mix tourmaline dispersion, cellulose pulp and NMMO solution, let stand to swell, and then mechanically stir under vacuum to obtain spinning solution. After spinning, tourmaline modified Lyocell fiber is obtained.

2. The preparation method according to claim 1, characterized in that, In step (1), the dispersion medium is an aqueous solution of NMMO with a mass percentage concentration of 50-74%.

3. The preparation method according to claim 1, characterized in that, In step (1), the grinding time is 10 min to 2 h and the ball milling speed is 200 to 1000 rpm.

4. The preparation method according to claim 1, characterized in that, The mass percentage concentration of the tourmaline dispersion in step (1) is 10-30%.

5. The preparation method according to claim 1, characterized in that, In step (2), the spinning process is Lyocell fiber spinning.

6. The preparation method according to claim 5, characterized in that, The spinning process parameters for Lyocell fibers are as follows: the spinning solution at 90-120 °C is metered by a metering pump under a nitrogen pressure of 0.2-0.6 MPa, extruded from the spinneret, and after passing through an air section of 5-200 mm, it enters a coagulation bath with a NMMO mass percentage concentration of 0-20%, solidifies and forms the fiber in a coagulation bath at 5-30 °C, and is wound at a speed of 50-200 m / min.

7. The preparation method according to claim 1, characterized in that, In step (2), the mass content of tourmaline in the tourmaline-modified Lyocell fiber is 5-40%.

8. A tourmaline-modified Lyocell fiber prepared by the method of claim 1.

9. The application of the tourmaline-modified Lyocell fiber as described in claim 8 in the fields of functional fibers, apparel textiles, home textiles, and industrial textiles.