阅读说明：本技术 一种阻燃着色功能性环保纤维的制备方法 (Preparation method of flame-retardant colored functional environment-friendly fiber ) 是由 朱国英 张井东 于 2020-11-13 设计创作，主要内容包括：本发明属于纤维领域,具体涉及一种阻燃着色功能性环保纤维的制备方法,包括如下步骤：步骤1：将聚乳酸粉体、环保色料、阻燃剂和纳米碳酸钙混合均匀,干燥后经螺杆挤出机挤出造粒得到原液着色阻燃聚乳酸母粒；步骤2,将原液着色阻燃聚乳酸母粒与聚乳酸切片进行纺丝和牵伸得到原液着色阻燃聚乳酸纤维。本发明解决了现有阻燃聚酯纤维阻燃效果不佳的问题,利用聚乳酸粉体的熔融造粒方式将阻燃剂进行侵入式混合,实现聚乳酸粉体的阻燃特性提升,从而达到提升整体性能的提升。(The invention belongs to the field of fibers, and particularly relates to a preparation method of flame-retardant colored functional environment-friendly fibers, which comprises the following steps: step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; and 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain the stock solution coloring flame-retardant polylactic acid fiber. The invention solves the problem of poor flame retardant effect of the existing flame retardant polyester fiber, and utilizes the melting granulation mode of polylactic acid powder to mix the flame retardant in an intrusive way, so as to realize the improvement of the flame retardant property of the polylactic acid powder, thereby achieving the improvement of the overall performance.)

1. A preparation method of flame-retardant colored functional environment-friendly fiber is characterized by comprising the following steps: the method comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch;

and 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain the stock solution coloring flame-retardant polylactic acid fiber.

2. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: in the stock solution coloring flame-retardant polylactic acid master batch, the mass percentage of polylactic acid powder is 65-82%, the mass percentage of environment-friendly pigment is 5-15%, the mass percentage of flame retardant is 12-15%, and the mass percentage of nano calcium carbonate is 3-5%.

3. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: the environment-friendly pigment adopts one of diamino diphenyl ethylene disulfonic acid, 4-diamino diphenyl urea and diamino heterocyclic ring.

4. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: the flame retardant is antimony trioxide or magnesium hydroxide.

5. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 4, characterized in that: the flame retardant is prepared from active aluminum oxide and antimony trioxide.

6. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: the nano calcium carbonate is light nano calcium carbonate.

7. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 6, characterized in that: the nano calcium titanate adopts film-coated light nano calcium carbonate.

8. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: the extrusion granulation adopts a hot-melt granulation method, and the temperature is 160-170 ℃.

9. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: the mass percentage of the stock solution cargo color flame-retardant polylactic acid master batch is 13-15%, and the mass percentage of the polylactic acid slices is 85-87%.

10. The method of preparing flame retardant colored functional environmental friendly fiber according to claim 1, characterized in that: the drawing tension is 0.5-0.9 MPa.

Technical Field

The invention belongs to the field of fibers, and particularly relates to a preparation method of flame-retardant colored functional environment-friendly fibers.

Background

The polyester fiber is a synthetic fiber obtained by spinning polyester formed by polycondensation of organic dibasic acid and dihydric alcohol, the polyester fiber is mainly used for clothing and interior decoration, and the short fiber can be pure spun and can also be blended with natural fiber and other chemical fibers; the filament can be processed into stretch yarn, tire cord, industrial rope, transmission belt, filter cloth, fishing net, etc., and can be used as electrical insulating material and artificial blood vessel.

Polyester fibers are widely applied due to the advantages of high strength, good elasticity and the like, but the application of the polyester fibers in many fields is limited due to the fact that the polyester fibers belong to flammable substances, so that research on flame-retardant copolyester fibers is widely concerned, and industrial production is successfully achieved. The fiber dope dyeing technology is a method for preparing colored fiber commonly used in the industry, and has the advantages of no water pollution caused by waste water, bright color, uniform color and difficult fading, so the method is widely regarded by the industry. However, the flame-retardant polyester fiber produced by the dope dyeing technology has poor flame-retardant effect, and the technical improvement on the basis of the technology is not available at present.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a preparation method of a flame-retardant colored functional environment-friendly fiber, which solves the problem of poor flame-retardant effect of the existing flame-retardant polyester fiber, and realizes the improvement of the flame-retardant property of polylactic acid powder by using the melting granulation mode of the polylactic acid powder to mix the flame retardant in an invasive manner, thereby achieving the improvement of the overall performance.

In order to achieve the technical purpose, the technical scheme of the invention is as follows:

a preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch;

and 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain the stock solution coloring flame-retardant polylactic acid fiber.

Further, in the stock solution coloring flame-retardant polylactic acid master batch, the mass percentage of the polylactic acid powder is 65-82%, the mass percentage of the environment-friendly pigment is 5-15%, the mass percentage of the flame retardant is 12-15%, and the mass percentage of the nano calcium carbonate is 3-5%.

The environment-friendly pigment adopts one of diamino diphenyl ethylene disulfonic acid, 4-diamino diphenyl urea and diamino heterocyclic ring.

The flame retardant is antimony trioxide or magnesium hydroxide.

Further, the flame retardant is prepared from active aluminum oxide composite antimony trioxide, and the preparation method of the active aluminum oxide composite antimony trioxide comprises the following steps: step i, adding antimony trichloride and aluminum trichloride into absolute ethyl alcohol, and uniformly stirring until the antimony trichloride and the aluminum trichloride are completely dissolved to obtain a dissolved alcohol solution, wherein the mass ratio of the antimony trichloride to the aluminum trichloride is 3-5:2, the concentration of the antimony trichloride in the absolute ethyl alcohol is 150g/L and the stirring speed is 1000-2000 r/min; and step ii, introducing saturated ammonia water into the dissolved alcohol solution until a precipitate is not formed any more, then filtering and washing with distilled water to obtain a precipitate, and drying at constant temperature to obtain the active aluminum oxide composite antimony trioxide, wherein the introduction amount of the saturated ammonia water is 5-10mL/min, the time is 60-120min, and the temperature for drying at constant temperature is 200-.

The nano calcium carbonate is light nano calcium carbonate.

Furthermore, the nano calcium titanate adopts film-coated light nano calcium carbonate.

The preparation method of the coated light nano calcium carbonate comprises the following steps:

step a, mixing calcium hydroxide powder and n-butyl titanate, adding the mixture into absolute ethyl alcohol, standing and drying to obtain coated calcium hydroxide powder; the adding amount of the n-butyl titanate is 10-20% of the mass of the calcium hydroxide, the mass of the absolute ethyl alcohol is 150-200% of the mass of the n-butyl titanate, and the temperature for standing and drying is 80-100 ℃; the particle size of the calcium hydroxide powder is 10-20 mu m;

b, stirring and mixing the coated calcium hydroxide powder and polyvinylpyrrolidone to form a blend, then performing electrostatic spinning to form a monofilament, and standing the monofilament in a sealed environment for 30-50min to obtain a prefabricated fiber; the addition amount of the polyvinylpyrrolidone is 150-200% of the mass of the coated calcium hydroxide, the temperature of electrostatic spinning is 135-145 ℃, the pressure of the closed environment is 0.3-0.5MPa, the temperature is 100-110 ℃, the closed environment consists of ether steam and water vapor, and the volume ratio of the ether steam to the water vapor is 10: 0.3-0.8;

step c, placing the prefabricated fiber filaments into absolute ethyl alcohol for microwave reaction for 30-50min, and filtering to obtain the film-coated light nano calcium carbonate; the concentration of the prefabricated fiber in the absolute ethyl alcohol is 100-200g/L, the power of the microwave reaction is 200-400W, and the temperature is 10-20 ℃;

and d, carrying out reduced pressure distillation on the filtered waste liquid to obtain polyvinylpyrrolidone and absolute ethyl alcohol, wherein the temperature of the reduced pressure distillation is 80-90 ℃, the pressure is 70-80% of the standard atmospheric pressure, the polyvinylpyrrolidone is recycled for the step b, and the absolute ethyl alcohol is recycled for the step a and the step c.

Furthermore, the extrusion granulation adopts a hot-melt granulation method, and the temperature is 160-170 ℃.

Further, the mass percentage of the stock solution cargo color flame-retardant polylactic acid master batch is 13-15%, and the mass percentage of the polylactic acid slices is 85-87%.

Further, the drawing tension is 0.5-0.9 MPa.

From the above description, it can be seen that the present invention has the following advantages:

1. the invention solves the problem of poor flame retardant effect of the existing flame retardant polyester fiber, and utilizes the melting granulation mode of polylactic acid powder to mix the flame retardant in an intrusive way, so as to realize the improvement of the flame retardant property of the polylactic acid powder, thereby achieving the improvement of the overall performance.

2. The invention adopts the antimony trioxide as the flame retardant, forms a stable molten state after combustion, forms a surface protective film for isolating air during the initial combustion, and forms uniform heat of the antimony trioxide if matching with the high heat conductivity of the aluminum oxide, thereby increasing the area of the protective liquid film.

3. The invention adopts light calcium carbonate as filler to form a stable micropore system, improves the stability, endows the calcium carbonate with good weather resistance and antibacterial property under the condition of using titanium dioxide as a coating layer, and simultaneously reduces the degradation influence of the titanium dioxide on organic molecules.

Detailed Description

The present invention is described in detail with reference to examples, but the present invention is not limited to the claims.

Example 1

A preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; in the stock solution coloring flame-retardant polylactic acid master batch, the mass percentage of polylactic acid powder is 65%, the mass percentage of environment-friendly pigment is 15%, the mass percentage of flame retardant is 15%, and the mass percentage of nano calcium carbonate is 5%; the environment-friendly pigment adopts diamino stilbene disulfonic acid; the flame retardant is antimony trioxide; the nano calcium carbonate is light nano calcium carbonate; the extrusion granulation adopts a hot melting granulation method, and the temperature is 160 ℃;

step 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain stock solution coloring flame-retardant polylactic acid fibers; the mass ratio of the stock solution cargo color flame-retardant polylactic acid master batch is 13%, and the mass ratio of the polylactic acid slices is 87%; the drawing force is 0.5 MPa.

Preparing the fiber: the limited oxygen index is 30 percent, the strength is 3.7cN/dtex, the color fastness to washing is 5 grades, and the sublimation fastness is 5 grades.

Example 2

A preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; in the stock solution coloring flame-retardant polylactic acid master batch, the mass percentage of polylactic acid powder is 82%, the mass percentage of environment-friendly pigment is 5%, the mass percentage of flame retardant is 10%, and the mass percentage of nano calcium carbonate is 3%; the environment-friendly pigment adopts 4.4-diaminodiphenylurea; the flame retardant is magnesium hydroxide; the nano calcium carbonate is light nano calcium carbonate; the extrusion granulation adopts a hot melting granulation method, and the temperature is 170 ℃;

step 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain stock solution coloring flame-retardant polylactic acid fibers; the mass ratio of the stock solution cargo color flame-retardant polylactic acid master batch is 15%, and the mass ratio of the polylactic acid slices is 85%; the drawing force is 0.9 MPa.

Preparing the fiber: the limited oxygen index is 32 percent, the strength is 3.9cN/dtex, the color fastness to washing is 5 grades, and the sublimation fastness is 5 grades.

Example 3

A preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; in the stock solution coloring flame-retardant polylactic acid master batch, the mass ratio of polylactic acid powder is 73%, the mass ratio of an environment-friendly pigment is 10%, the mass ratio of a flame retardant is 13%, and the mass ratio of nano calcium carbonate is 4%; the environment-friendly pigment adopts one of diamino diphenyl ethylene disulfonic acid, 4-diamino diphenyl urea and diamino heterocyclic ring; the flame retardant is antimony trioxide or magnesium hydroxide; the nano calcium carbonate is light nano calcium carbonate; the extrusion granulation adopts a hot melting granulation method, and the temperature is 165 ℃;

step 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain stock solution coloring flame-retardant polylactic acid fibers; the mass percentage of the stock solution cargo color flame-retardant polylactic acid master batch is 14 percent, and the mass percentage of the polylactic acid slices is 86 percent; the drawing force is 0.7 MPa.

Preparing the fiber: the limiting oxygen index is 31 percent, the strength is 3.8cN/dtex, the color fastness to washing is 5 grades, and the sublimation fastness is 5 grades.

Example 4

A preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; in the stock solution coloring flame-retardant polylactic acid master batch, the mass percentage of polylactic acid powder is 65%, the mass percentage of environment-friendly pigment is 15%, the mass percentage of flame retardant is 15%, and the mass percentage of nano calcium carbonate is 5%; the environment-friendly pigment adopts diamino stilbene disulfonic acid; the flame retardant adopts active aluminum oxide composite antimony trioxide, and the preparation method comprises the following steps: step i, adding antimony trichloride and aluminum trichloride into 1L of absolute ethyl alcohol, and uniformly stirring until the antimony trichloride and the aluminum trichloride are completely dissolved to obtain a dissolved alcohol solution, wherein the mass ratio of the antimony trichloride to the aluminum trichloride is 3:2, the concentration of the antimony trichloride in the absolute ethyl alcohol is 100g/L, and the stirring speed is 1000 r/min; step ii, introducing saturated ammonia water into the dissolved alcohol solution until no precipitate is formed, then filtering and washing with distilled water to obtain a precipitate, and drying at constant temperature to obtain the active aluminum oxide composite antimony trioxide, wherein the introduction amount of the saturated ammonia water is 5mL/min, the time is 60min, and the temperature for drying at constant temperature is 200 ℃; the nano calcium carbonate adopts coated light nano calcium carbonate, and the preparation method of the coated light nano calcium carbonate comprises the following steps: step a, mixing 100g of calcium hydroxide powder and n-butyl titanate, adding the mixture into absolute ethyl alcohol, standing and drying to obtain coated calcium hydroxide powder; the adding amount of the n-butyl titanate is 10 percent of the mass of the calcium hydroxide, the mass of the absolute ethyl alcohol is 150 percent of the mass of the n-butyl titanate, and the temperature of standing and drying is 80 ℃; the particle size of the calcium hydroxide powder is 10 mu m; b, stirring and mixing the coated calcium hydroxide powder and polyvinylpyrrolidone to form a blend, then performing electrostatic spinning to form a monofilament, and standing the monofilament in a sealed environment for 30min to obtain prefabricated fiber; the addition amount of the polyvinylpyrrolidone is 150% of the mass of the coated calcium hydroxide, the temperature of electrostatic spinning is 135 ℃, the pressure of the closed environment is 0.3MPa, the temperature is 100 ℃, the closed environment consists of ether steam and water vapor, and the volume ratio of the ether steam to the water vapor is 10: 0.3; step c, placing the prefabricated fiber filaments into 1L of absolute ethyl alcohol for microwave reaction for 30min, and filtering to obtain the film-coated light nano calcium carbonate; the concentration of the prefabricated fiber filaments in absolute ethyl alcohol is 100g/L, the power of the microwave reaction is 200W, and the temperature is 10 ℃; d, carrying out reduced pressure distillation on the filtered waste liquid to obtain polyvinylpyrrolidone and absolute ethyl alcohol, wherein the temperature of the reduced pressure distillation is 80 ℃, the pressure is 70% of the standard atmospheric pressure, the polyvinylpyrrolidone is recycled in the step b, and the absolute ethyl alcohol is recycled in the steps a and c; the extrusion granulation adopts a hot melting granulation method, and the temperature is 160 ℃;

step 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain stock solution coloring flame-retardant polylactic acid fibers; the mass ratio of the stock solution cargo color flame-retardant polylactic acid master batch is 13%, and the mass ratio of the polylactic acid slices is 87%; the drawing force is 0.5 MPa.

Preparing the fiber: the limited oxygen index is 33 percent, the strength is 3.9cN/dtex, the color fastness to washing is 5 grades, and the sublimation fastness is 5 grades.

Example 5

A preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; in the stock solution coloring flame-retardant polylactic acid master batch, the mass percentage of polylactic acid powder is 82%, the mass percentage of environment-friendly pigment is 5%, the mass percentage of flame retardant is 10%, and the mass percentage of nano calcium carbonate is 3%; the environment-friendly pigment adopts 4.4-diaminodiphenylurea; the flame retardant is prepared from active aluminum oxide and antimony trioxide, and the preparation method of the active aluminum oxide and antimony trioxide comprises the following steps: step i, adding antimony trichloride and aluminum trichloride into 1L of absolute ethyl alcohol, and uniformly stirring until the antimony trichloride and the aluminum trichloride are completely dissolved to obtain a dissolved alcohol solution, wherein the mass ratio of the antimony trichloride to the aluminum trichloride is 5:2, the concentration of the antimony trichloride in the absolute ethyl alcohol is 150g/L, and the stirring speed is 2000 r/min; step ii, introducing saturated ammonia water into the dissolved alcohol solution until no precipitate is formed, then filtering and washing with distilled water to obtain a precipitate, and drying at constant temperature to obtain the active aluminum oxide composite antimony trioxide, wherein the introduction amount of the saturated ammonia water is 5mL/min, the time is 120min, and the drying temperature at constant temperature is 250 ℃; the nano calcium carbonate is film-coated light nano calcium carbonate, and the preparation method comprises the following steps: step a, mixing 100g of calcium hydroxide powder and n-butyl titanate, adding the mixture into absolute ethyl alcohol, standing and drying to obtain coated calcium hydroxide powder; the adding amount of the n-butyl titanate is 20 percent of the mass of the calcium hydroxide, the mass of the absolute ethyl alcohol is 200 percent of the mass of the n-butyl titanate, and the temperature of standing and drying is 100 ℃; the particle size of the calcium hydroxide powder is 20 mu m; b, stirring and mixing the coated calcium hydroxide powder and polyvinylpyrrolidone to form a blend, then performing electrostatic spinning to form a monofilament, and standing the monofilament in a sealed environment for 50min to obtain prefabricated fiber; the addition amount of the polyvinylpyrrolidone is 200% of the mass of the coated calcium hydroxide, the temperature of electrostatic spinning is 145 ℃, the pressure of the closed environment is 0.5MPa, the temperature is 110 ℃, the closed environment consists of ether steam and water vapor, and the volume ratio of the ether steam to the water vapor is 10: 0.3-0.8; step c, placing the prefabricated fiber filaments into 1L of absolute ethyl alcohol for microwave reaction for 50min, and filtering to obtain the film-coated light nano calcium carbonate; the concentration of the prefabricated fiber filaments in absolute ethyl alcohol is 200g/L, the power of the microwave reaction is 400W, and the temperature is 20 ℃; d, carrying out reduced pressure distillation on the filtered waste liquid to obtain polyvinylpyrrolidone and absolute ethyl alcohol, wherein the temperature of the reduced pressure distillation is 90 ℃, the pressure is 80% of the standard atmospheric pressure, the polyvinylpyrrolidone is recycled in the step b, and the absolute ethyl alcohol is recycled in the steps a and c; the extrusion granulation adopts a hot melting granulation method, and the temperature is 170 ℃;

step 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain stock solution coloring flame-retardant polylactic acid fibers; the mass ratio of the stock solution cargo color flame-retardant polylactic acid master batch is 15%, and the mass ratio of the polylactic acid slices is 85%; the drawing force is 0.9 MPa.

Preparing the fiber: the limited oxygen index is 35 percent, the strength is 3.9cN/dtex, the color fastness to washing is 5 grades, and the sublimation fastness is 5 grades.

Example 6

A preparation method of flame-retardant colored functional environment-friendly fibers comprises the following steps:

step 1: uniformly mixing polylactic acid powder, an environment-friendly pigment, a flame retardant and nano calcium carbonate, drying, and then extruding and granulating by a screw extruder to obtain stock solution coloring flame-retardant polylactic acid master batch; in the stock solution coloring flame-retardant polylactic acid master batch, the mass ratio of polylactic acid powder is 73%, the mass ratio of an environment-friendly pigment is 10%, the mass ratio of a flame retardant is 13%, and the mass ratio of nano calcium carbonate is 4%; the environment-friendly pigment adopts diamino heterocyclic; the flame retardant adopts active aluminum oxide composite antimony trioxide, and the preparation method comprises the following steps: step i, adding antimony trichloride and aluminum trichloride into 1L of absolute ethyl alcohol, and uniformly stirring until the antimony trichloride and the aluminum trichloride are completely dissolved to obtain a dissolved alcohol solution, wherein the mass ratio of the antimony trichloride to the aluminum trichloride is 2:1, the concentration of the antimony trichloride in the absolute ethyl alcohol is 1350g/L, and the stirring speed is 1500 r/min; step ii, introducing saturated ammonia water into the dissolved alcohol solution until no precipitate is formed, then filtering and washing with distilled water to obtain a precipitate, and drying at constant temperature to obtain the active aluminum oxide composite antimony trioxide, wherein the introduction amount of the saturated ammonia water is 8mL/min, the time is 90min, and the temperature for drying at constant temperature is 230 ℃; the nano calcium carbonate is film-coated light nano calcium carbonate, and the preparation method comprises the following steps: step a, mixing 100g of calcium hydroxide powder and n-butyl titanate, adding the mixture into absolute ethyl alcohol, standing and drying to obtain coated calcium hydroxide powder; the adding amount of the n-butyl titanate is 15% of the mass of the calcium hydroxide, the mass of the absolute ethyl alcohol is 180% of the mass of the n-butyl titanate, and the temperature of standing and drying is 90 ℃; the particle size of the calcium hydroxide powder is 15 mu m; b, stirring and mixing the coated calcium hydroxide powder and polyvinylpyrrolidone to form a blend, then performing electrostatic spinning to form a monofilament, and standing the monofilament in a sealed environment for 40min to obtain prefabricated fiber; the addition amount of the polyvinylpyrrolidone is 180% of the mass of the coated calcium hydroxide, the temperature of electrostatic spinning is 140 ℃, the pressure of the closed environment is 0.4MPa, the temperature is 105 ℃, the closed environment consists of ether steam and water vapor, and the volume ratio of the ether steam to the water vapor is 10: 0.5; step c, placing the prefabricated fiber filaments into 1L of absolute ethyl alcohol for microwave reaction for 40min, and filtering to obtain the film-coated light nano calcium carbonate; the concentration of the prefabricated fiber filaments in absolute ethyl alcohol is 150g/L, the power of the microwave reaction is 300W, and the temperature is 15 ℃; d, carrying out reduced pressure distillation on the filtered waste liquid to obtain polyvinylpyrrolidone and absolute ethyl alcohol, wherein the temperature of the reduced pressure distillation is 85 ℃, the pressure is 75% of the standard atmospheric pressure, the polyvinylpyrrolidone is recycled in the step b, and the absolute ethyl alcohol is recycled in the steps a and c; the extrusion granulation adopts a hot melting granulation method, and the temperature is 165 ℃;

step 2, spinning and drafting the stock solution coloring flame-retardant polylactic acid master batch and the polylactic acid slices to obtain stock solution coloring flame-retardant polylactic acid fibers; the mass percentage of the stock solution cargo color flame-retardant polylactic acid master batch is 14 percent, and the mass percentage of the polylactic acid slices is 86 percent; the drawing force is 0.7 MPa.

Preparing the fiber: the limited oxygen index is 35 percent, the strength is 3.9cN/dtex, the color fastness to washing is 5 grades, and the sublimation fastness is 5 grades.

In summary, the invention has the following advantages:

1. the invention solves the problem of poor flame retardant effect of the existing flame retardant polyester fiber, and utilizes the melting granulation mode of polylactic acid powder to mix the flame retardant in an intrusive way, so as to realize the improvement of the flame retardant property of the polylactic acid powder, thereby achieving the improvement of the overall performance.

2. The invention adopts the antimony trioxide as the flame retardant, forms a stable molten state after combustion, forms a surface protective film for isolating air during the initial combustion, and forms uniform heat of the antimony trioxide if matching with the high heat conductivity of the aluminum oxide, thereby increasing the area of the protective liquid film.

3. The invention adopts light calcium carbonate as filler to form a stable micropore system, improves the stability, endows the calcium carbonate with good weather resistance and antibacterial property under the condition of using titanium dioxide as a coating layer, and simultaneously reduces the degradation influence of the titanium dioxide on organic molecules.

It should be understood that the detailed description of the invention is merely illustrative of the invention and is not intended to limit the invention to the specific embodiments described. It will be appreciated by those skilled in the art that the present invention may be modified or substituted equally as well to achieve the same technical result; as long as the use requirements are met, the method is within the protection scope of the invention.