CN115559007A

CN115559007A - Extinction lyocell fiber and production method thereof

Info

Publication number: CN115559007A
Application number: CN202211164737.8A
Authority: CN
Inventors: 叶小波; 方斌; 胡志钢; 唐林
Original assignee: Dangyang Hongyang New Material Technology Co ltd
Current assignee: Dangyang Hongyang New Material Technology Co ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2023-01-03
Anticipated expiration: 2042-09-23
Also published as: CN115559007B

Abstract

The application discloses an extinction lyocell fiber and a production method thereof, and the production method comprises the following steps: adding anatase titanium dioxide into an N-methylmorpholine-N-oxide aqueous solution with the mass fraction of 45-55% to obtain a first mixture system; subjecting the first mixture system to ultrasonic treatment; stirring the first mixture system after ultrasonic treatment at 40-50 ℃ and carrying out heat treatment to obtain a second mixture system; concentrating the second mixture system until the mass fraction of the N-methylmorpholine-N-oxide is 88-89%, adding wood pulp powder, and uniformly stirring to obtain a spinning stock solution; and (3) spinning, washing, oiling, curling, drying and cutting the spinning solution in sequence to obtain the delustered lyocell fiber. The production method can improve the mechanical property of the prepared extinction lyocell fiber.

Description

Extinction lyocell fiber and production method thereof

Technical Field

The application belongs to the technical field of lyocell fiber preparation, and particularly relates to an extinction lyocell fiber and a production method thereof.

Background

The optical properties of the fibers can be improved by adding a white pigment to the spinning dope of the fibers, which is called spinning matting, and the added white pigment is called a "matting agent". Anatase titanium dioxide has good refractive index and enough strength, strong adhesive force, stable property and high melting point, is considered as the best white pigment at present, and is widely used in the industries of paint, plastics, rubber, cosmetics, chemical fibers and the like. Anatase titanium dioxide is commonly used as a delustering agent in the chemical fiber industry. For example, CN202011590640.4 discloses a clean high-whiteness extinction viscose fiber and a preparation method thereof, which comprises the steps of adding titanium dioxide and a modifier into viscose subjected to alkalization, yellowing, dissolution, aging and filtration before reaching a spinning workshop, reacting with an acid bath to generate extinction viscose fiber, converging the extinction viscose fiber into a tow, strongly drafting and cutting the tow to reach a fiber tank, opening the tow by three paths of steam, sending the tow to a refiner, sequentially carrying out first washing, desulfurization, second washing, bleaching, third washing, acid washing, fourth washing and oiling, fully opening the tow by a wet opener, then entering a dryer, and drying the tow by steam to obtain the clean high-whiteness extinction viscose fiber. CN201710907819.X discloses a semi-dull profiled ultra-high molecular weight polyethylene fiber and a preparation method thereof, the fiber is prepared by using ultra-high molecular weight polyethylene and white oil as raw materials, adding nano titanium dioxide as a delustering agent to prepare a spinning stock solution, and performing wet spinning by using a profiled spinneret, wherein the cross section of the fiber is in a cross shape. The fiber is developed based on the modern chemical fiber technology, is an ultra-high molecular weight polyethylene fiber with a special section, has ultraviolet resistance, and has the advantages of ventilation, perspiration, cool contact and high strength. The woven fabric has drapability and is suitable for being processed into high-grade and special textiles.

Lyocell is a novel renewable cellulose fiber, and has many advantages of natural fibers and synthetic fibers, such as good drapability, high strength, easy dyeing, thick hand feeling, and the like. And the production process of the lyocell fiber is simple, the raw material source is renewable, and the production process has no pollution to the environment, so the lyocell fiber is known as novel low-carbon green environment-friendly fiber with the development potential. However, no relevant process report of the delustered lyocell fiber exists at present, because of the particularity of a lyocell fiber production system, the delustered lyocell fiber cannot be prepared by simply adding titanium dioxide into a spinning solution system like a conventional fiber in the production process, and the direct addition mainly causes the problem of system compatibility and the reduction of the mechanical property of the prepared lyocell fiber.

Disclosure of Invention

The application aims to overcome the defects of the prior art and provide the delustered lyocell fiber and the production method thereof.

To achieve the above object, in a first aspect of the present application, there is provided a method for producing a mat lyocell fiber, comprising the steps of:

adding anatase titanium dioxide into an N-methylmorpholine-N-oxide aqueous solution with the mass fraction of 45-55% to obtain a first mixture system; subjecting the first mixture system to ultrasonic treatment;

stirring the first mixture system after ultrasonic treatment at 40-50 ℃ and carrying out heat treatment to obtain a second mixture system;

concentrating the second mixture system until the mass fraction of the N-methylmorpholine-N-oxide is 88-89%, adding wood pulp powder, and uniformly stirring to obtain a spinning stock solution;

and sequentially spinning, washing, oiling, curling, drying and cutting the spinning solution to obtain the delustering lyocell fiber.

Furthermore, the ultrasonic treatment frequency is 200-2000 kHz, the power is 100-400W, and the time is 10-30 min.

Further, the time of the heat treatment is 1 to 3 hours.

Further, the addition amount of the titanium dioxide is 0.4-3% of the mass of the wood pulp powder.

Further, in the spinning solution, the solid content of the wood pulp powder is 8-12%.

Furthermore, propyl gallate is also added into the spinning solution.

Furthermore, the addition amount of the propyl gallate is 0.1-1 per mill of the mass of the wood pulp powder.

Further, the spinning process is as follows: and adding the spinning solution into a screw extruder, further dissolving at 95-110 ℃, filtering, and then feeding into a spinning system.

Further, the temperature of the water washing is 65-70 ℃, and the time is 2-3 minutes; the oiling temperature is 50-55 ℃, and the time is 3-5 seconds.

In a second aspect of the present application, there is provided a delustered lyocell fiber produced by the production method described in any one of the above.

Compared with the prior art, the method has the following technical effects:

according to the production method of the extinction lyocell fiber, the added titanium dioxide is subjected to ultrasonic treatment and is further matched with heat treatment, so that the uniform dispersibility of the titanium dioxide in the N-methylmorpholine-N-oxide aqueous solution can be improved, the preparation of the spinning stock solution with the titanium dioxide highly dispersed uniformly is facilitated, and the mechanical property of the prepared extinction lyocell fiber can be improved.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a diagram showing a state of dispersion of a dope provided in example 1 of the present application, which is observed under a polarization microscope;

FIG. 2 is a view showing a state of dispersion of a dope provided in comparative example 1 of the present application under a polarizing microscope;

FIG. 3 is a view showing the dispersion state of the dope of comparative example 2 of the present application under a polarizing microscope.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In this application, the term "and/or" describes an association relationship of associated objects, which means that there may be three relationships, for example, a and/or B, which may mean: a is present alone, A and B are present simultaneously, and B is present alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the present application, "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, "at least one (a), b, or c", or "at least one (a), b, and c", may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, and c may be single or plural, respectively.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present application as long as it is scaled up or down according to the description of the embodiments of the present application. Specifically, the mass described in the specification of the examples of the present application may be a mass unit known in the chemical field such as μ g, mg, g, kg, etc.

The terms "first" and "second" are used for descriptive purposes only and are used for distinguishing purposes such as substances from one another, and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the present application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In a first aspect, embodiments of the present application provide a method for producing a delustered lyocell fiber, including the steps of:

(1) Adding anatase titanium dioxide into an N-methylmorpholine-N-oxide aqueous solution with the mass fraction of 45-55% to obtain a first mixture system; subjecting the first mixture system to ultrasonic treatment;

(2) Stirring the first mixture system after ultrasonic treatment at 40-50 ℃ and carrying out heat treatment to obtain a second mixture system;

(3) Concentrating the second mixture system until the mass fraction of the N-methylmorpholine-N-oxide is 88-89%, adding wood pulp powder, and uniformly stirring to obtain a spinning stock solution;

(4) And (3) spinning, washing, oiling, curling, drying and cutting the spinning solution in sequence to obtain the delustered lyocell fiber.

In the step (1), the particle size of the anatase titanium dioxide used in the embodiment of the present application is less than or equal to 1 μm, and the particle size of the titanium dioxide is very small, so that the titanium dioxide is easily agglomerated in a solvent and is difficult to disperse uniformly. In the embodiment of the application, the ultrasonic treatment frequency can be selected to be 200-2000 kHz, the power is 100-400W, and the time is 10-30 min.

In the step (2), the embodiment of the present application further promotes the dispersion uniformity of titanium dioxide in the N-methylmorpholine-N-oxide (NMMO) aqueous solution through a heat treatment manner. In the heat treatment process, active groups on the molecular structure of the 4-methylmorpholine-N-oxide can further generate stronger chemical bonding force with titanium dioxide molecules, thereby inhibiting the agglomeration among the titanium dioxide molecules and promoting the uniform dispersion of the titanium dioxide molecules. In the embodiment of the present application, the time for the heat treatment may be selected from 1 to 3 hours.

In the step (3), in order to accelerate the dissolution and uniform dispersion of the wood pulp powder, in the embodiment of the application, the wood pulp powder is added after the N-methylmorpholine-N-oxide aqueous solution is concentrated to 88-89% by mass of the N-methylmorpholine-N-oxide by means of vacuum pumping. In the prepared spinning solution, the addition amount of the titanium dioxide is 0.4-3% of the mass of the wood pulp powder. The solid content of the wood pulp powder is 8-12%. In the embodiment of the application, the addition amount of the titanium dioxide is adjusted according to the requirements of the semi-dull fiber and the extinction fiber, wherein the addition amount of the titanium dioxide in the semi-dull fiber is 0.4-0.5% of the mass of the wood pulp powder, and the addition amount of the titanium dioxide in the extinction fiber is 2-3% of the mass of the wood pulp powder.

In the examples of the present application, propyl gallate was also added to the dope as an antioxidant. The addition amount of the propyl gallate is 0.1-1 per mill of the mass of the wood pulp powder.

In the step (4), in the embodiment of the present application, the spinning process is as follows: adding the spinning solution into a screw extruder, further dissolving at 95-110 ℃, filtering and then entering a spinning system. Further, the temperature of water washing is 65-70 ℃, and the time is 2-3 minutes; the temperature of oiling is 50-55 ℃, and the time is 3-5 seconds.

In a second aspect of the embodiments of the present application, there is provided a mat lyocell fiber produced by the above-described production method.

The matte lyocell fiber and the production method thereof according to the examples of the present application will be illustrated below by way of specific examples.

Example 1

The embodiment 1 of the application provides an extinction lyocell fiber and a production method thereof, and the extinction lyocell fiber comprises the following steps:

(1) Adding anatase titanium dioxide accounting for 2 percent of the mass of the wood pulp powder into 1L of N-methylmorpholine-N-oxide aqueous solution with the mass fraction of 50 percent to obtain a first mixture system; the first mixture system was sonicated at a frequency of 1000kHz, at a power of 200W, for a period of 20min. (ii) a

(2) Stirring the first mixture system after ultrasonic treatment at 50 ℃ and carrying out heat treatment for 2h to obtain a second mixture system;

(3) Concentrating the second mixture system until the mass fraction of the N-methylmorpholine-N-oxide is 88-89%, adding wood pulp powder, and uniformly stirring to obtain a spinning stock solution, wherein the solid content of the wood pulp powder in the spinning stock solution is 10%;

(4) Adding the spinning solution into a screw extruder, further dissolving at 95 ℃, filtering and then entering a spinning system. Wherein, the length of the air gap is 8cm, the spinning speed is 40m/min, the aperture of the spinneret plate is 95um, the length of the capillary tube is 500um, the sprayed silk is vertically stretched in the air and enters a coagulating bath for forming; then soaking the glass fiber cloth into hot water at the temperature of 75 ℃ for washing for 2 minutes; then, the steel sheet was immersed in an oil bath at a temperature of 55 ℃ for oiling for 3 seconds. Finally, the delustered lyocell fiber is prepared by curling, drying and cutting. A part of the spinning dope in the spinning system was taken and observed for dispersion under a polarizing microscope, and the observation results are shown in FIG. 1.

Example 2

The embodiment 2 of the application provides an extinction lyocell fiber and a production method thereof, and the production method comprises the following steps:

(1) Adding anatase titanium dioxide accounting for 0.5 percent of the mass of the wood pulp powder into 1L of the aqueous solution of N-methylmorpholine-N-oxide with the mass fraction of 45 percent to obtain a first mixture system; the first mixture system was sonicated at a frequency of 1000kHz, at a power of 400W, for a period of 15min. (ii) a

(2) Stirring the first mixture system after ultrasonic treatment at 45 ℃ and carrying out heat treatment for 3 hours to obtain a second mixture system;

(3) Concentrating the second mixture system until the mass fraction of the N-methylmorpholine-N-oxide is 88-89%, adding wood pulp powder, and uniformly stirring to obtain a spinning stock solution, wherein the solid content of the wood pulp powder in the spinning stock solution is 8%;

(4) Adding the spinning solution into a screw extruder, further dissolving at 100 ℃, filtering and then entering a spinning system. Wherein, the length of the air gap is 8cm, the spinning speed is 40m/min, the aperture of the spinneret plate is 95um, the length of the capillary tube is 500um, the sprayed silk is vertically stretched in the air and enters a coagulating bath for forming; then soaking the glass fiber cloth into hot water at the temperature of 75 ℃ for washing for 2 minutes; then, the steel sheet was immersed in an oil bath at a temperature of 75 ℃ for applying oil for 3 seconds. Finally, the delustering lyocell fiber is prepared by curling, drying and cutting.

Example 3

The embodiment 3 of the application provides an extinction lyocell fiber and a production method thereof, and the production method comprises the following steps:

(1) Adding anatase titanium dioxide accounting for 3 percent of the mass of the wood pulp powder into 1L of N-methylmorpholine-N-oxide aqueous solution with the mass fraction of 55 percent to obtain a first mixture system; the first mixture system was sonicated at a frequency of 1000kHz, at a power of 500W, for a period of 30min. (ii) a

(2) Stirring the first mixture system after ultrasonic treatment at 50 ℃ and carrying out heat treatment for 3h to obtain a second mixture system;

(3) Concentrating the second mixture system until the mass fraction of the N-methylmorpholine-N-oxide is 88-89%, adding wood pulp powder, and uniformly stirring to obtain a spinning stock solution, wherein the solid content of the wood pulp powder in the spinning stock solution is 12%;

(4) Adding the spinning solution into a screw extruder, further dissolving at 110 ℃, filtering and then entering a spinning system. Wherein the length of the air gap is 8cm, the spinning speed is 40m/min, the aperture of a spinneret plate is 95um, the length of a pore capillary is 500um, and the sprayed silk is vertically stretched in the air and enters a coagulating bath for forming; then soaking the glass substrate into hot water at the temperature of 75 ℃ for washing for 2 minutes; then, the steel sheet was immersed in an oil bath at a temperature of 55 ℃ for oiling for 3 seconds. Finally, the delustered lyocell fiber is prepared by curling, drying and cutting.

Comparative example 1

It is different from example 1 in that the heat treatment in step (2) is not performed, and other treatment process conditions are the same. A part of the spinning dope in the spinning system was taken and observed for dispersion under a polarizing microscope, and the observation results are shown in FIG. 2.

Comparative example 2

Titanium dioxide is directly added in the conventional lyocell fiber production process, and the specific steps are as follows:

(1) Adding wood pulp powder into 88-89% of water solution of N-methylmorpholine-N-oxide, adding anatase titanium dioxide accounting for 2% of the mass of the wood pulp powder, and uniformly stirring to obtain a spinning stock solution, wherein the solid content of the wood pulp powder in the spinning stock solution is 10%;

(2) Adding the spinning solution into a screw extruder, further dissolving at 95 ℃, filtering and then entering a spinning system. Wherein, the length of the air gap is 8cm, the spinning speed is 40m/min, the aperture of the spinneret plate is 95um, the length of the capillary tube is 500um, the sprayed silk is vertically stretched in the air and enters a coagulating bath for forming; then soaking the glass fiber cloth into hot water at the temperature of 75 ℃ for washing for 2 minutes; then, the steel sheet was immersed in an oil bath at a temperature of 55 ℃ for oiling for 3 seconds. Finally, the delustered lyocell fiber is prepared by curling, drying and cutting. A part of the spinning dope in the spinning system was taken and observed for dispersion under a polarizing microscope, and the observation results are shown in FIG. 3.

As can be seen from fig. 1, 2 and 3, a clear black line (the part outlined in fig. 2 and 3) is observed in the spinning solution prepared in the comparative example 1 and 2, and the black line is judged to be formed by agglomeration of trace titanium dioxide, indicating that the production method of the comparative example 1 and 2 cannot prepare highly dispersed and uniform spinning solution. No significant black line was observed in FIG. 1, indicating that the dope formulated in the examples of this application is a highly dispersed, homogeneous mixture system.

The mechanical properties of the extinction lyocell fibers prepared in the embodiments 1-3 and the comparative examples 1-2 of the application are tested, the mechanical property test method refers to GB/T-24218.3-2010, a FAVIMAT-BOBOBOT 2 full-automatic single fiber universal tester is adopted for testing, no less than 30 test samples are obtained, and the test average value is taken. The test results are shown in the following table.

As can be seen from the test results of the above table, the mat lyocell fibers prepared in the examples of the present application have more excellent mechanical properties than the mat lyocell fibers prepared in comparative examples 1 and 2.

The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A production method of delustered lyocell fibers is characterized by comprising the following steps:

2. The process for producing a matted lyocell fiber according to claim 1, wherein said ultrasonic treatment is carried out at a frequency of 200 to 2000kHz and at a power of 100 to 400W for a period of 10 to 30 minutes.

3. A process for the production of matted lyocell fibre according to claim 1, wherein said heat treatment is carried out for a period of from 1 to 3 hours.

4. The method for producing delustered lyocell fibers according to claim 1, wherein the addition amount of the titanium dioxide is 0.4 to 3 percent of the mass of the wood pulp powder.

5. The process for producing matted lyocell fibers according to claim 1, wherein said wood pulp powder has a solid content of 8 to 12% in said spinning dope.

6. A process for the production of delustered lyocell according to any one of claims 1 to 5 wherein propyl gallate is also added to the dope.

7. The process for producing delustered lyocell according to claim 6, wherein the amount of propyl gallate added is 0.1 to 1% by mass of the wood pulp powder.

8. A process for the production of matted lyocell fibre according to claim 1, wherein said spinning process comprises: and adding the spinning solution into a screw extruder, further dissolving at 95-110 ℃, filtering, and then feeding into a spinning system.

9. The process for producing a matted lyocell fiber according to claim 1, wherein said water washing is carried out at a temperature of 65 to 70 ℃ for 2 to 3 minutes; the temperature of oiling is 50-55 ℃, and the time is 3-5 seconds.

10. A delustered lyocell fiber characterized in that it is produced by the production method according to any one of claims 1 to 9.