A lightweight, soft and warm fiber and its preparation method

Abstract

The present invention provides a light, soft and warm fiber and a preparation method thereof. The preparation method comprises the following steps: (1) preparing a powder dispersion; (2) adding wood pulp into an aqueous solution of 7-9 wt% NaOH and 10-12 wt% urea, dissolving uniformly at -12°C to obtain a cellulose solution with a mass percentage content of 7%; (3) adding a nano-titanium dioxide modified filler into water to prepare a nano-titanium dioxide modified filler dispersion with a mass percentage content of 7%; (4) mixing the cellulose solution, the powder dispersion and the nano-titanium dioxide modified filler dispersion to obtain a spinning solution; (5) extruding the spinning solution into a gradient dilute sulfuric acid coagulation bath with different concentrations for coagulation, washing with water and drying to obtain a warm regenerated cellulose fiber. By the synergistic action among cellulose, powder and nano-titanium dioxide modified filler, the present invention improves the warmth retention property of the fiber and has good mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of textiles, and particularly relates to a light, soft and warm fiber and a preparation method thereof. Background Art

[0002] Warmth-preserving fibers have positive heat-insulating properties, can absorb external heat, and give a better sense of warmth to the human body. Regenerated cellulose fiber is a fiber made from natural cellulose as raw material, which has the advantages of good hygroscopicity, easy dyeing, and low static electricity generation, and is widely used in the fields of clothing, textiles, etc.

[0003] Regenerated cellulose fibers also have some deficiencies. For example, compared with some natural fibers, the strength of regenerated cellulose fibers is lower, and they are prone to stretching and deformation, especially in the wet state. And when preparing warmth-preserving fibers with regenerated cellulose fibers as the matrix, the warmth-preserving property is not ideal. Chinese Patent No. 201710691878.8 discloses a preparation method of a quick-heating warmth-preserving cellulose fiber. By adding a quick-heating material and a temperature-regulating material before the spinning and forming of the cellulose fiber, the prepared fiber can have the function of generating heat and keeping warm by pure spinning. However, the regenerated cellulose fiber prepared by this method has a high shrinkage rate, resulting in poor dimensional stability of the finished fabric.

[0004] Therefore, there is an urgent need for a regenerated cellulose fiber with good warmth preservation, mechanical properties and low shrinkage rate. Summary of the Invention

[0005] The purpose of the present invention is to provide a light, soft and warm fiber and a preparation method thereof.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation method of a light, soft and warm fiber, comprising the following steps:

[0008] (1) Weigh 46 - 49 parts by mass of a reaction monomer, 36 - 39 parts by mass of myristyl alcohol, 0.2 - 0.4 parts by mass of benzoyl peroxide, and 12 - 15 parts by mass of ethylene glycol dimethacrylate, and mix them evenly to obtain Component A; mix 2 - 4 parts by mass of sodium dodecylbenzenesulfonate, 1 - 3 parts by mass of sodium hexametaphosphate, 3 - 5 parts by mass of polyethylene glycol 200 and 100 parts by mass of water evenly to obtain Component B; add Component A with a mass ratio of 3:10 - 12 to Component B, stir at a rotation speed of 1000 - 1200 rpm for 30 - 40 min, react for 7 - 9 h under the condition of an 82 - 85 °C water bath, filter, wash, dry to obtain a powder; place the powder in an aqueous carboxymethyl cellulose solution with a mass concentration of 0.2 - 0.4%, and ultrasonically disperse it evenly to obtain a powder dispersion;

[0009] (2) adding wood pulp to a mixed aqueous solution of 7-9 wt% NaOH and 10-12 wt% urea, dissolving the mixture at -12°C to obtain a cellulose solution having a mass percentage of 7%;

[0010] (3) adding the nano-titanium oxide modified filler into water to prepare a nano-titanium oxide modified filler dispersion having a mass percentage of 7%;

[0011] (4) mixing a cellulose solution, a powder dispersion, and a nano-titanium oxide modified filler dispersion in a mass ratio of (75-78):(16-19):(5-8) to obtain a spinning solution;

[0012] (5) The spinning solution is directly extruded into a dilute sulfuric acid with a mass percentage concentration of 15% to coagulate for 4 seconds, and then pulled into a dilute sulfuric acid coagulation bath with a mass percentage concentration of 10% by a winding roller for deep curing for 7 seconds, and then pulled into a dilute sulfuric acid with a mass percentage concentration of 5% to mature for 6 seconds. After washing, drying, and winding, the heat-retaining regenerated cellulose fiber is obtained.

[0013] Furthermore, the reaction monomers are a mixture of butyl methacrylate, methyl methacrylate and hydroxyethyl acrylate in a mass ratio of (0.4-0.6):1:(1.5-1.8).

[0014] The powder of the present invention is a polymer material formed by copolymerizing a plurality of raw materials such as butyl methacrylate, methyl methacrylate and hydroxyethyl acrylate at a certain ratio. A component B of a specific ratio is added to the system of the present invention as an emulsifier system, and the warmth retention of the fiber can be improved through the synergistic effect between the components. By adding the component B of the present invention, the particles obtained by the emulsion polymerization of the present invention can have a smaller size, which helps to form a denser fiber structure, reduce air flow, and thus improve thermal insulation performance. The powder prepared by the present invention can improve the wet breaking strength of the fiber. However, the shrinkage rate of the fiber under this condition is relatively high.

[0015] Furthermore, the mass concentration of the powder in the carboxymethyl cellulose aqueous solution is 0.02-0.04 g / mL.

[0016] Furthermore, the preparation method of the nano titanium oxide modified filler is:

[0017] (1) Under a nitrogen atmosphere, 1 part by mass of 3-isocyanate propyltrimethoxysilane and 0.13-0.15 parts by mass of filler are mixed, ultrasonicated for 20-30 minutes, 50-54 parts by mass of N,N-dimethylformamide are added, stirred at 100-105° C. for 2-3 hours, centrifuged, and freeze-dried to obtain a modified filler;

[0018] (2) Mix 10 parts by mass of the modified filler and 60 - 64 parts by mass of ethanol, then add titanium oxide nanoparticles, stir at 55 - 60 °C for 2 - 3 h, centrifuge, and freeze-dry to obtain the titanium oxide nanoparticle-modified filler.

[0019] Further, the filler is a mixture of graphene oxide, carboxylated double-walled carbon nanotubes, and carboxylated silica with a mass ratio of (1.5 - 1.8) : (0.4 - 0.6) : 1.

[0020] Further, the mass ratio of the modified filler to titanium oxide nanoparticles is 10 : 1 - 3.

[0021] Further, the carboxylated double-walled carbon nanotubes have a diameter of 2 - 4 nm, a length of 0.5 - 2 μm, and a carboxyl content of 2.58 wt%. Purchased from Xianfeng Nano, product number: 100227.

[0022] Further, the graphene oxide has a sheet diameter of 0.5 - 5 μm and a thickness of 0.8 - 1.2 nm. Purchased from Xianfeng Nano.

[0023] Further, the average size of the carboxylated silica is 20 nm. Purchased from Xianfeng Nano, product number: 103113.

[0024] Further, the average particle size of the titanium oxide nanoparticles is 15 nm, and the specific surface area is 30 - 100 m 2 / g. Beijing Decod Island King Technology Co., Ltd.

[0025] The present invention attempts to add graphene oxide to improve the shrinkage rate of the fiber, but the effect is not ideal, and the dispersibility of graphene oxide in the whole system is not ideal. The present invention reduces the shrinkage rate of the fiber by mixing three different fillers and using titanium oxide nanoparticles for modification. Titanium dioxide nanoparticles increase the interlayer spacing between graphene oxides, effectively slowing down their agglomeration phenomenon, improving the dispersibility of graphene oxide in the system. Titanium oxide nanoparticles can form a stable composite structure with cellulose. The modified graphene oxide, carboxylated carbon nanotubes, and silica form a stable network structure with cellulose through chemical bonding. The modified filler can be embedded between the structures of other components to form a more compact structure, thereby reducing the shrinkage rate. At the same time, the dry breaking elongation of the fiber is improved.

[0026] The present invention also provides a light, soft, and warm fiber prepared by the above preparation method.

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0028] 1. The present invention improves the warmth retention of the fiber through the synergistic effect among cellulose, powder, and titanium oxide nanoparticle-modified filler, and has good mechanical properties. The fiber is light, warm, and comfortable and breathable at the same time.

[0029] 2. The powder of the present invention is formed by copolymerizing various raw materials such as butyl methacrylate, methyl methacrylate, and 2-hydroxyethyl acrylate in a certain proportion to form a polymer material. A specific emulsifier system is added to the system of the present invention, and the warmth retention property of the fiber can be improved through the synergistic effect among components.

[0030] 3. By mixing three different fillers and modifying with nano-titanium oxide, the shrinkage rate of the fiber can be reduced, and the dry breaking elongation rate of the fiber is improved. Specific Embodiments

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0032] Example 1

[0033] This example provides a light, soft and warm fiber, and the preparation method includes the following steps:

[0034] (1) Weigh 48 parts by mass of reaction monomers, 37 parts by mass of myristyl alcohol, 0.3 parts by mass of benzoyl peroxide, and 13 parts by mass of ethylene glycol dimethacrylate, and mix them evenly to obtain Component A; mix 3 parts by mass of sodium dodecylbenzenesulfonate, 2 parts by mass of sodium hexametaphosphate, 4 parts by mass of polyethylene glycol 200 and 100 parts by mass of water evenly to obtain Component B; add Component A with a mass ratio of 3:11 to Component B, stir at a rotation speed of 1100 rpm for 35 min, react for 8 h under the water bath condition of 84 °C, filter, wash, dry to obtain a powder; place the powder in an aqueous solution of carboxymethyl cellulose with a mass concentration of 0.3%, and disperse it evenly by ultrasonic waves to obtain a powder dispersion;

[0035] (2) Add wood pulp to an aqueous solution of a mixture of 8 wt% NaOH and 11 wt% urea, and dissolve it evenly at -12 °C to obtain a cellulose solution with a mass percentage of 7%;

[0036] (3) Add the nano-titanium oxide modified filler to water to prepare a nano-titanium oxide modified filler dispersion with a mass percentage of 7%;

[0037] (4) Mix the cellulose solution, the powder dispersion, and the nano-titanium oxide modified filler dispersion with a mass ratio of 77:18:7 to obtain a spinning solution;

[0038] (5) The spinning solution is directly extruded into a dilute sulfuric acid with a mass percentage concentration of 15% to coagulate for 4 seconds, and then pulled into a dilute sulfuric acid coagulation bath with a mass percentage concentration of 10% by a winding roller for deep curing for 7 seconds, and then pulled into a dilute sulfuric acid with a mass percentage concentration of 5% to mature for 6 seconds. After washing, drying, and winding, the heat-retaining regenerated cellulose fiber is obtained.

[0039] The reaction monomers are a mixture of butyl methacrylate, methyl methacrylate and hydroxyethyl acrylate in a mass ratio of 0.5:1:1.7.

[0040] The mass concentration of the powder in the carboxymethyl cellulose aqueous solution is 0.03 g / mL.

[0041] The preparation method of nano titanium oxide modified filler is:

[0042] (1) Under a nitrogen atmosphere, 1 part by mass of 3-isocyanatepropyltrimethoxysilane and 0.14 parts by mass of filler were mixed, ultrasonicated for 25 minutes, 52 parts by mass of N,N-dimethylformamide were added, stirred at 102° C. for 2.5 hours, centrifuged, and freeze-dried to obtain a modified filler;

[0043] (2) 10 parts by mass of the modified filler and 62 parts by mass of ethanol were mixed, and then nano-titanium oxide was added, stirred at 58° C. for 2.6 hours, centrifuged, and freeze-dried to obtain a nano-titanium oxide modified filler.

[0044] The filler is a mixture of graphene oxide, carboxylated double-walled carbon nanotubes and carboxylated silicon dioxide in a mass ratio of 1.7:0.5:1.

[0045] The mass ratio of the modified filler to nano-titanium oxide is 5:1.

[0046] The carboxylated double-walled carbon nanotubes have a diameter of 2-4 nm, a length of 0.5-2 μm, and a carboxyl content of 2.58 wt %. They were purchased from Xianfeng Nano, item number: 100227.

[0047] The graphene oxide has a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm and was purchased from Xianfeng Nano.

[0048] The average size of carboxylated silica is 20 nm and it was purchased from Xianfeng Nano, item number: 103113.

[0049] The average particle size of nano titanium oxide is 15nm, and the specific surface area is 30-100m 2 / g. Beijing Dekedaojin Technology Co., Ltd.

[0050] Example 2

[0051] This embodiment provides a light, soft and warm fiber, and the preparation method includes the following steps:

[0052] (1) Weigh 46 parts by mass of the reaction monomer, 36 parts by mass of myristyl alcohol, 0.2 parts by mass of benzoyl peroxide, and 12 parts by mass of ethylene glycol dimethacrylate, and mix them evenly to obtain Component A; mix 2 parts by mass of sodium dodecylbenzenesulfonate, 1 part by mass of sodium hexametaphosphate, 3 parts by mass of polyethylene glycol 200, and 100 parts by mass of water evenly to obtain Component B; add Component A with a mass ratio of 3:10 to Component B, stir at a speed of 1000 rpm for 30 min, react for 7 h under the condition of an 82 °C water bath, filter, wash, and dry to obtain a powder; place the powder in an aqueous solution of carboxymethyl cellulose with a mass concentration of 0.2%, and disperse it evenly by ultrasonic treatment to obtain a powder dispersion;

[0053] (2) Add wood pulp to an aqueous solution of a mixture of 7 wt% NaOH and 10 wt% urea, and dissolve it evenly at -12 °C to obtain a cellulose solution with a mass percentage of 7%;

[0054] (3) Add the nano-titanium oxide modified filler to water to prepare a nano-titanium oxide modified filler dispersion with a mass percentage of 7%;

[0055] (4) Mix the cellulose solution, the powder dispersion, and the nano-titanium oxide modified filler dispersion with a mass ratio of 75:16:5 to obtain a spinning solution;

[0056] (5) Directly extrude the spinning solution into dilute sulfuric acid with a mass percentage concentration of 15% to solidify for 4 s, pull it through a winding roller into a dilute sulfuric acid coagulation bath with a mass percentage concentration of 10% for deep curing for 7 s, and then pull it into 5% dilute sulfuric acid for ripening for 6 s. After washing, drying, and winding, warm regenerated cellulose fibers are obtained.

[0057] The reaction monomer is a mixture of butyl methacrylate, methyl methacrylate, and 2-hydroxyethyl acrylate with a mass ratio of 0.4:1:1.5.

[0058] The mass concentration of the powder in the aqueous carboxymethyl cellulose solution is 0.02 g / mL.

[0059] The preparation method of the nano-titanium oxide modified filler is as follows:

[0060] (1) Under a nitrogen atmosphere, mix 1 part by mass of 3-isocyanatopropyltrimethoxysilane and 0.13 part by mass of the filler, carry out ultrasonic treatment for 20 min, add 50 parts by mass of N,N-dimethylformamide, stir at 100 °C for 2 h, centrifuge, and freeze-dry to obtain a modified filler;

[0061] (2) Mix 10 parts by mass of the modified filler and 60 parts by mass of ethanol, then add nano-titanium oxide, stir at 55 °C for 2 h, centrifuge, and freeze-dry to prepare the nano-titanium oxide modified filler.

[0062] The filler is a mixture of graphene oxide, carboxylated double-walled carbon nanotubes, and carboxylated silica with a mass ratio of 1.5:0.4:1.

[0063] The mass ratio of the modified filler to nano-titanium oxide is 10:1.

[0064] The carboxylated double-walled carbon nanotubes have a diameter of 2 - 4 nm, a length of 0.5 - 2 μm, and a carboxyl content of 2.58 wt%. Purchased from Xianfeng Nano, product number: 100227.

[0065] The sheet diameter of graphene oxide is 0.5 - 5 μm, and the thickness is 0.8 - 1.2 nm. Purchased from Xianfeng Nano.

[0066] The average size of carboxylated silica is 20 nm. Purchased from Xianfeng Nano, product number: 103113.

[0067] The average particle size of nano-titanium oxide is 15 nm, and the specific surface area is 30 - 100 m 2 / g. Beijing Decod Island Gold Technology Co., Ltd.

[0068] Example 3

[0069] This example provides a light, soft, and warm fiber, and the preparation method includes the following steps:

[0070] (1) Weigh 49 parts by mass of reaction monomers, 39 parts by mass of myristyl alcohol, 0.4 parts by mass of benzoyl peroxide, and 15 parts by mass of ethylene glycol dimethacrylate, and mix them evenly to obtain Component A; mix 4 parts by mass of sodium dodecylbenzenesulfonate, 3 parts by mass of sodium hexametaphosphate, 5 parts by mass of polyethylene glycol 200, and 100 parts by mass of water evenly to obtain Component B; add Component A with a mass ratio of 1:4 to Component B, stir at a speed of 1200 rpm for 40 min, react in a water bath at 85°C for 9 h, filter, wash, dry to obtain a powder; place the powder in an aqueous carboxymethyl cellulose solution with a mass concentration of 0.4%, and disperse it evenly by ultrasonic treatment to obtain a powder dispersion;

[0071] (2) Add wood pulp to a mixed aqueous solution of 9 wt% NaOH and 12 wt% urea, and dissolve it evenly at -12°C to obtain a cellulose solution with a mass percentage of 7%;

[0072] (3) Add the nano-titanium oxide modified filler to water to prepare a nano-titanium oxide modified filler dispersion with a mass percentage of 7%;

[0073] (4) Mix the cellulose solution, powder dispersion, and nano-titanium oxide modified filler dispersion with a mass ratio of 78:19:8 to obtain a spinning solution;

[0074] (5) The spinning solution is directly extruded into a dilute sulfuric acid with a mass percentage concentration of 15% to coagulate for 4 seconds, and then pulled into a dilute sulfuric acid coagulation bath with a mass percentage concentration of 10% by a winding roller for deep curing for 7 seconds, and then pulled into a dilute sulfuric acid with a mass percentage concentration of 5% to mature for 6 seconds. After washing, drying, and winding, the heat-retaining regenerated cellulose fiber is obtained.

[0075] The reaction monomers are a mixture of butyl methacrylate, methyl methacrylate and hydroxyethyl acrylate in a mass ratio of 0.6:1:1.8.

[0076] The mass concentration of the powder in the carboxymethyl cellulose aqueous solution is 0.04 g / mL.

[0077] The preparation method of nano titanium oxide modified filler is:

[0078] (1) Under a nitrogen atmosphere, 1 part by mass of 3-isocyanatepropyltrimethoxysilane and 0.15 parts by mass of filler were mixed, ultrasonicated for 30 minutes, 54 parts by mass of N,N-dimethylformamide were added, stirred at 105° C. for 3 hours, centrifuged, and freeze-dried to obtain a modified filler;

[0079] (2) 10 parts by mass of the modified filler and 64 parts by mass of ethanol were mixed, and then nano-titanium oxide was added, stirred at 60° C. for 3 h, centrifuged, and freeze-dried to obtain a nano-titanium oxide modified filler.

[0080] The filler is a mixture of graphene oxide, carboxylated double-walled carbon nanotubes and carboxylated silicon dioxide in a mass ratio of 1.8:0.6:1.

[0081] The mass ratio of the modified filler to nano-titanium oxide is 10:3.

[0082] The carboxylated double-walled carbon nanotubes have a diameter of 2-4 nm, a length of 0.5-2 μm, and a carboxyl content of 2.58 wt %. They were purchased from Xianfeng Nano, item number: 100227.

[0083] The graphene oxide has a sheet diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm and was purchased from Xianfeng Nano.

[0084] The average size of carboxylated silica is 20 nm and it was purchased from Xianfeng Nano, item number: 103113.

[0085] The average particle size of nano titanium oxide is 15nm, and the specific surface area is 30-100m 2 / g. Beijing Dekedaojin Technology Co., Ltd.

[0086] Comparative Example 1

[0087] The difference between this comparative example and Example 1 is as follows: 6 parts by mass of sodium dodecylbenzenesulfonate, 6 parts by mass of sodium hexametaphosphate, 1 part by mass of polyethylene glycol 200 and 100 parts by mass of water are mixed evenly to obtain Component B.

[0088] Comparative Example 2

[0089] The difference between this comparative example and Example 1 is as follows: The reaction monomers are a mixture of butyl methacrylate, methyl methacrylate and 2-hydroxyethyl acrylate with a mass ratio of 1:1:1.

[0090] Comparative Example 3

[0091] The difference between this comparative example and Example 1 is as follows: The filler is a mixture of graphene oxide, carboxylated double-walled carbon nanotubes and carboxylated silica with a mass ratio of 1:1:1.

[0092] Comparative Example 4

[0093] The difference between this comparative example and Example 1 is as follows: Ethylene glycol dimethacrylate is replaced by divinylbenzene.

[0094] Comparative Example 5

[0095] The difference between this comparative example and Example 1 is as follows: The average size of carboxylated silica is 100 nm. Purchased from Xianfeng Nano, product number: 103114.

[0096] Comparative Example 6

[0097] The difference between this comparative example and Example 1 is as follows: The sheet diameter of graphene oxide is 10 - 20 μm and the thickness is 1.2 - 1.5 nm. Purchased from Shanghai Xiangtian Nano Materials Co., Ltd.

[0098] Comparative Example 7

[0099] The difference between this comparative example and Example 1 is as follows: The diameter of carboxylated double-walled carbon nanotubes is 10 - 20 nm, the length is 0.5 - 2 μm, and the carboxyl content is 2 wt%. Purchased from Xianfeng Nano, product number: 100262.

[0100] Performance Test

[0101] The fibers prepared in Examples 1 - 3 and Comparative Examples 1 - 7 were subjected to performance tests.

[0102] Referring to 《GB / T 8628 - 2013》, the shrinkage rate of the fabric made of the fiber was detected. It was less than 2%.

[0103] Referring to 《GB / T11048 - 2018》, the heat retention rate of the fiber was detected.

[0104] Referring to 《GB / T 14337 - 2008》, the wet breaking strength and dry breaking elongation of the fiber were detected.

[0105] The results are shown in Table 1.

[0106] Table 1 Performance Test Results

[0107]

[0108] From the above performance test results, it can be seen that the comprehensive performance of Examples 1-3 is excellent, especially the comprehensive performance of Example 1 is the most prominent. This is mainly because the components work synergistically.

[0109] For the comparative examples, since the necessary technical solutions were not adopted, their performance in the corresponding performance tests is significantly worse than that of the examples. In Comparative Examples 1-2, the preparation method of the powder was changed, and it can be seen that the heat preservation effect decreased. In Comparative Examples 3-7, the nano-titanium oxide modified filler solution was not used, and it can be seen from the results that the shrinkage situation was aggravated. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0110] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a light, soft and warm fiber, characterized in that: The following steps are involved: (1) Weigh 46-49 parts by weight of a reaction monomer, 36-39 parts by weight of tetradecanol, 0.2-0.4 parts by weight of dibenzoyl peroxide, and 12-15 parts by weight of ethylene glycol dimethacrylate, and mix them evenly to obtain component A; mix 2-4 parts by weight of sodium dodecylbenzene sulfonate, 1-3 parts by weight of sodium hexametaphosphate, 3-5 parts by weight of polyethylene glycol 200, and 100 parts by weight of water evenly to obtain component B; add component A to component B in a mass ratio of 3:10-12, stir at a speed of 1000-1200 rpm for 30-40 minutes, react in a water bath at 82-85° C. for 7-9 hours, filter, wash, and dry to obtain a powder; place the powder in a carboxymethyl cellulose aqueous solution with a mass concentration of 0.2-0.4%, and disperse it evenly by ultrasonication to obtain a powder dispersion; (2) adding wood pulp to a mixed aqueous solution of 7-9wt% NaOH and 10-12wt% urea, dissolving the wood pulp uniformly to obtain a cellulose solution with a mass percentage of 7%; (3) Adding the nano-titanium oxide modified filler into water to prepare a nano-titanium oxide modified filler dispersion having a mass percentage of 7%; (4) mixing a cellulose solution, a powder dispersion, and a nano-titanium oxide modified filler dispersion in a mass ratio of (75-78):(16-19):(5-8) to obtain a spinning solution; (5) extruding the spinning solution into a gradient dilute sulfuric acid coagulation bath of different concentrations for coagulation, washing with water, and drying to obtain the heat-retaining regenerated cellulose fiber; The reaction monomers are a mixture of butyl methacrylate, methyl methacrylate and hydroxyethyl acrylate in a mass ratio of (0.4-0.6):1:(1.5-1.8); The preparation method of nano titanium oxide modified filler is: (1) Under a nitrogen atmosphere, 1 part by mass of 3-isocyanatepropyltrimethoxysilane and 0.13-0.15 parts by mass of filler were mixed, ultrasonicated for 20-30 minutes, 50-54 parts by mass of N,N-dimethylformamide were added, stirred at 100-105° C. for 2-3 hours, centrifuged, and freeze-dried to obtain a modified filler; (2) 10 parts by weight of the modified filler and 60-64 parts by weight of ethanol are mixed, and then nano-titanium oxide is added, stirred at 55-60° C. for 2-3 hours, centrifuged, and freeze-dried to obtain a nano-titanium oxide modified filler; The filler is a mixture of graphene oxide, carboxylated double-walled carbon nanotubes and carboxylated silicon dioxide in a mass ratio of (1.5-1.8): (0.4-0.6): 1; The mass ratio of modified filler to nano-titanium oxide is 10:1-3; The diameter of carboxylated double-walled carbon nanotubes is 2-4 nm, the length is 0.5-2 μm, and the carboxyl content is 2.58wt%; The sheet diameter of graphene oxide is 0.5~5μm and the thickness is 0.8-1.2nm; The average size of carboxylated silica is 20 nm.

2. The method for preparing the light, soft and warm fiber according to claim 1, characterized in that: The average particle size of nano titanium oxide is 15nm, and the specific surface area is 30-100m 2 / g.

3. A light, soft and warm fiber made by the preparation method according to any one of claims 1 to 2.

Images