Easy-to-dye porous modified polyester fiber and preparing method thereof

Abstract

A type of easy-to-dye porous modified polyester fibers and preparing method thereof are disclosed. The preparing method is using the modified polyester melt through a porous spinneret with FDY process; wherein the modified polyester is a product of an esterification and successive polycondensation reactions of an evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, and metal oxide doped Sb.sub.2O.sub.3 powder; wherein the main chain silicated diol is selected from the group consisting of dimethylsiloxane diol, dimethyldiphenyldisiloxane glycol and tetramethyldisiloxane diol. The structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is as follows: ##STR00001## The dye uptake and the K/S value of the prepared easy-to-dye porous modified polyester fiber are high. This invention features a method with ease of application and a product with good dyeing performance and good quality.

Claims

1. A preparing method for an easy-to-dye porous modified polyester fiber, comprising manufacturing the easy-to-dye porous modified polyester fiber by melting a modified polyester through a porous spinneret with FDY process; wherein the porous spinneret has more than 100 holes; the modified polyester is a product of an esterification and successive polycondensation reactions of an evenly mixed mixture of terephthalic acid, ethylene glycol, main chain silicated diol, 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, and doped Sb.sub.2O.sub.3 powder; wherein the main chain silicated diol is selected from the group consisting of dimethylsiloxane diol, dimethyldiphenyldisiloxane glycol and tetramethyldisiloxane diol; and a structural formula of the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is as follows: ##STR00006## wherein the doped Sb.sub.2O.sub.3 powder is obtained through a process of evenly mixing an aqueous solution containing metal ions M.sup.x+ and a solution containing Sb.sup.3+ to obtain a mixed solution, then adding in a precipitant to the mixed solution until a pH value of the mixed solution becomes 9-10 to form a precipitate, and finally calcining and crushing the precipitate; wherein the metal ions M.sup.x+ is one or more selected from the group consisting of Mg.sup.2+, Ca.sup.2+, Ba.sup.2+ and Zn.sup.2+.

2. The preparing method of claim 1, wherein the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is a product of a process comprising cooling, crystallization and refining of an evenly mixed mixture of palladium acetate and di-tert-butyl dimethyl ethylene, adding a 10-15% mass concentration of a hydrogen peroxide solution and reacting at 70-75° C. for 3-4 h, wherein a mass ratio of the di-tert-butyl dimethyl ethylene, the hydrogen peroxide solution and the palladium acetate is 1:(1.5-2.0):0.015.

3. The preparing method of claim 2, wherein the aqueous solution containing metal ions M.sup.x+ is an aqueous one with a concentration of 0.5-1.0 mol %, wherein an anion of the aqueous solution is NO.sub.3.sup.−; the solution containing Sb.sup.3+ is a product of dissolving 5-10 mol % of Sb.sub.2O.sub.3 in oxalic acid; the precipitant is ammonia water with a concentration of 2 mol/L; the mixed solution has a 1-3:100 molar ratio of the metal ions M.sup.x+ and the Sb.sup.3+ before adding in the precipitant; wherein after forming the precipitate, the calcining is preceded by a washing process and a drying process, and the drying process is carried out under a temperature of 105-110° C. for 2-3 h; wherein the calcining comprises steps of heating at 400° C. for 2-3 h, heating at 900° C. for 1-2 h and cooling in air to obtain a doped Sb.sub.2O.sub.3; then crushing the doped Sb.sub.2O.sub.3 into powder with an average size of less than 0.5 μm.

4. The preparing method of claim 3, wherein the modified polyester is manufactured through the following steps: (1) Esterification concocting the terephthalic acid, the ethylene glycol, the main chain silicated diol and the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry, and adding in the doped Sb.sub.2O.sub.3 powder, a matting agent and a stabilizer, then carrying out the esterification under a nitrogen atmosphere with a pressure ranged from an atmospheric pressure to 0.3 MPa, wherein a reaction temperature is 250-260° C., finally ending the esterification when a water distillation rate reaches 90% of a theoretical value; (2) Polycondensation after smoothly reducing the pressure of the nitrogen atmosphere from the atmospheric pressure to less than 500 Pa within 30-50 min, conducting a low vacuum polycondensation for products of the esterification at 250-260° C. for 30-50 min, then further reducing the pressure to less than 100 Pa and continuing with a high vacuum polycondensation at 270-282° C. for 50-90 min.

5. The preparing method of claim 4, wherein a molar ratio of the terephthalic acid and the ethylene glycol is 1:(1.2-2.0), and a total addition of the main chain silicated diol and the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is 4-6 mol % of an amount of the terephthalic acid, and a molar ratio of the main chain silicated diol and the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is (1-2):(1-2); and an amount of the doped Sb.sub.2O.sub.3 powder, the matting agent and the stabilizer is 0.012-0.015 wt %, 0.20-0.25 wt %, and 0.01-0.05 wt % of the amount of the terephthalic acid, respectively.

6. The preparing method of claim 5, wherein the matting agent is titanium dioxide, and wherein the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.

7. The preparing method of claim 6, wherein the modified polyester has a molecular weight of 25000-30000 Da and a molecular weight distribution index of 1.8-2.2.

8. The preparing method of claim 1, wherein the porous spinneret has 144-288 holes; wherein the FDY process comprises the steps of metering, spinneret extruding, cooling, oiling, stretching, heat setting and winding; wherein a spinning temperature is 285-295° C., a cooling temperature is 17-22° C., an interlacing pressure is 0.20-0.30 MPa, a first godet roller speed is 2300-2700 m/min, a first godet roller temperature is 80-90° C., a second godet roller speed is 4000-4200 m/min, a second godet roller temperature is 125-140° C., and a winding speed is 3940-4120 m/min.

9. An easy-to-dye porous modified polyester fiber manufactured by the preparing method of claim 1, wherein a bunch of filaments contain more than 100 modified polyester FDY; wherein the modified polyester has a molecular chain structure composed of terephthalic acid segments, ethylene glycol segments, main chain silicated diol segments and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol segments; wherein the modified polyester is dispersed with the doped Sb.sub.2O.sub.3 powder.

10. The easy-to-dye porous modified polyester fiber of claim 9, wherein the easy-to-dye porous modified polyester fiber has mechanical performance indices of monofilament fineness 0.3-0.5 dtex, a breaking strength≥3.5 cN/dtex, an elongation at break 30.0±4.0%, an interlacing degree 15±3/m, a linear density deviation rate≤1.0%, a breaking strength CV value≤5.0%, a breaking elongation CV value≤9.0%, a boiling water shrinkage rate 6.5±0.5%, and 144-288 modified polyester FDY in the bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 87.3-92.8% (at 120° C.), and a K/S value of 22.35-25.43.

11. The easy-to-dye porous modified polyester fiber of claim 9, wherein the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is a product of a process comprising cooling, crystallization and refining of an evenly mixed mixture of palladium acetate and di-tert-butyl dimethyl ethylene, adding a 10-15% mass concentration of a hydrogen peroxide solution and reacting at 70-75° C. for 3-4 h, wherein a mass ratio of the di-tert-butyl dimethyl ethylene, the hydrogen peroxide solution and the palladium acetate is 1:(1.5-2.0): 0.015.

12. The easy-to-dye porous modified polyester fiber of claim 11, wherein the aqueous solution containing metal ions M.sup.x+ is an aqueous one with a concentration of 0.5-1.0 mol %, wherein an anion of the aqueous solution is NO.sub.3.sup.−; the solution containing Sb.sup.3+ is a product of dissolving 5-10 mol % of Sb.sub.2O.sub.3 in oxalic acid; the precipitant is ammonia water with a concentration of 2 mol/L; the mixed solution has a 1-3:100 molar ratio of the metal ions M′ and the Sb.sup.3+ before adding in the precipitant; wherein after forming the precipitate, the calcining is preceded by a washing process and a drying process, and the drying process is carried out under a temperature of 105-110° C. for 2-3 h; wherein the calcining comprises steps of heating at 400° C. for 2-3 h, heating at 900° C. for 1-2 h and cooling in air to obtain a doped Sb.sub.2O.sub.3; then crushing the doped Sb.sub.2O.sub.3 into powder with an average size of less than 0.5 μm.

13. The easy-to-dye porous modified polyester fiber of claim 12, wherein the modified polyester is manufactured through the following steps: (1) Esterification concocting the terephthalic acid, the ethylene glycol, the main chain silicated diol and the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry, and adding in the doped Sb.sub.2O.sub.3 powder, a matting agent and a stabilizer, then carrying out the esterification under a nitrogen atmosphere with a pressure ranged from an atmospheric pressure to 0.3 MPa, wherein a reaction temperature is 250-260° C., finally ending the esterification when a water distillation rate reaches 90% of a theoretical value; (2) Polycondensation after smoothly reducing the pressure of the nitrogen atmosphere from the atmospheric pressure to less than 500 Pa within 30-50 min, conducting a low vacuum polycondensation for products of the esterification at 250-260° C. for 30-50 min, then further reducing the pressure to less than 100 Pa and continuing with a high vacuum polycondensation at 270-282° C. for 50-90 min.

14. The easy-to-dye porous modified polyester fiber of claim 13, wherein a molar ratio of the terephthalic acid and the ethylene glycol is 1:(1.2-2.0), and a total addition of the main chain silicated diol and the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is 4-6 mol % of an amount of the terephthalic acid, and a molar ratio of the main chain silicated diol and the 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is (1-2):(1-2); and an amount of the doped Sb.sub.2O.sub.3 powder, the matting agent and the stabilizer is 0.012-0.015 wt %, 0.20-0.25 wt %, and 0.01-0.05 wt % of the amount of the terephthalic acid, respectively.

15. The easy-to-dye porous modified polyester fiber of claim 14, wherein the matting agent is titanium dioxide, and wherein the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.

16. The easy-to-dye porous modified polyester fiber of claim 15, wherein the modified polyester has a molecular weight of 25000-30000 Da and a molecular weight distribution index of 1.8-2.2.

17. The easy-to-dye porous modified polyester fiber of claim 9, wherein the porous spinneret has 144-288 holes; wherein the FDY process comprises the steps of metering, spinneret extruding, cooling, oiling, stretching, heat setting and winding; wherein a spinning temperature is 285-295° C., a cooling temperature is 17-22° C., an interlacing pressure is 0.20-0.30 MPa, a first godet roller speed is 2300-2700 m/min, a first godet roller temperature is 80-90° C., a second godet roller speed is 4000-4200 m/min, a second godet roller temperature is 125-140° C., and a winding speed is 3940-4120 m/min.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) Based on above mentioned method, the following embodiments are carried out for further demonstration in the present invention. It is to be understood that these embodiments are only intended to illustrate the invention and are not intended to limit the scope of the invention. In addition, it should be understood that after reading the contents described in the present invention, technicians in this field can make various changes or modifications to the invention, and these equivalent forms also fall within the scope of the claims attached to the application.

(2) ##STR00005##

Example 1

(3) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(4) (1) Preparation of modified polyester;

(5) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(6) (1.1.1) evenly mixing a 0.8 mol % of Mg(NO.sub.3).sub.2 aqueous solution and a 8 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 2:100 of molar ratio of Mg.sup.2+ and Sb.sup.3+;

(7) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 9, then washing and drying (105° C., 2.5 h) the precipitate;

(8) (1.1.3) after the treatment composed of a heating at 400° C. for 2.5 h, a heating at 900° C. for 1.5 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.4 μm;

(9) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 10% mass concentration of hydrogen peroxide solution and reacting at 72° C. for 3 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:2.0:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(10) (1.3) Esterification

(11) concocting terephthalic acid, ethylene glycol, dimethylsiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:1.2, the total addition of dimethylsiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 1:2 is 4 mol % relative to the amount of terephthalic acid), and adding in 0.015 wt % of the doped Sb.sub.2O.sub.3 powder, 0.20 wt % of titanium dioxide and 0.03 wt % of triphenyl phosphate (all are relative to the amount of terephthalic acid), then carrying out the esterification under a 0.2 MPa of nitrogen pressure at 260° C., finally ending the reaction when the water distillation rate reaches 95% of the theoretical value;

(12) (1.4) Polycondensation

(13) after smoothly reducing the pressure from normal value to 490 Pa within 40 min, conducting the low vacuum polycondensation for the esterification products at 260° C. for 50 min, then further reducing the pressure to 85 Pa and continuing the high vacuum polycondensation at 280° C. for 90 min, finally obtaining the modified polyester with a molecular weight of 30000 Da and a molecular weight distribution index of 2.2;

(14) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 285° C.), cooling (at 17° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.20 MPa, first godet roller speed 2300 m/min, first godet roller temperature 80° C., second godet roller speed 4000 m/min, second godet roller temperature 125° C.), and winding (3940 m/min).

(15) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.5 dtex, breaking strength 3.8 cN/dtex, elongation at break 34.0%, interlacing degree 18/m, linear density deviation rate 0.8%, breaking strength CV value 4.0%, breaking elongation CV value 7.2%, boiling water shrinkage rate 7.0%, and 288 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 87.3% (at 120° C.), and its K/S value is 22.35.

(16) Comparison 1

(17) A method for preparing a modified polyester FDY involves steps basically the same as those in Example 1, except for 2,2,3,4,5,5-hexamethyl-3,4-hexanediol and dimethylsiloxane diol aren't added in step (1). The prepared modified polyester FDY possess the performance indices of monofilament fineness 0.5 dtex, breaking strength 3.7 cN/dtex, elongation at break 35.0%, interlacing degree 18/m, linear density deviation rate 0.8%, breaking strength CV value 4.1%, breaking elongation CV value 7.2%, boiling water shrinkage rate 7.2%, and 288 modified polyester FDY in a bunch of filaments; under the same conditions as in Example 1, it has a dye uptake rate of 83.7% (at 120° C.), and its K/S value is 20.36.

(18) Comparison 2

(19) A method for preparing a modified polyester FDY involves steps basically the same as those in Example 1, except for 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is not added in step (1). The prepared modified polyester FDY possess the performance indices of monofilament fineness 0.5 dtex, breaking strength 3.7 cN/dtex, elongation at break 36.0%, interlacing degree 18/m, linear density deviation rate 0.9%, breaking strength CV value 4.0%, breaking elongation CV value 7.5%, boiling water shrinkage rate 7.0%, and 288 modified polyester FDY in a bunch of filaments; under the same conditions as in Example 1, it has a dye uptake rate of 85.8% (at 120° C.), and its K/S value is 21.37.

(20) Comparison 3

(21) A method for preparing a modified polyester FDY involves steps basically the same as those in Example 1, except for dimethylsiloxane diol isn't added in step (1). The prepared modified polyester FDY possess the performance indices of monofilament fineness 0.5 dtex, breaking strength 3.7 cN/dtex, elongation at break 37.0%, interlacing degree 18/m, linear density deviation rate 0.9%, breaking strength CV value 4.0%, breaking elongation CV value 7.5%, boiling water shrinkage rate 7.0%, and 288 modified polyester FDY in a bunch of filaments; under the same conditions as in Example 1, it has a dye uptake rate of 85.9% (at 120° C.), and its K/S value is 21.28.

(22) Comparing Example 1 and Comparisons 1-3, it is shown that adding 2,2,3,4,5,5-hexamethyl-3,4-hexanediol and dimethylsiloxane diol significantly improves the dyeing performance of the fiber. When they are synergistic with each other, both of them can increase the void free volume of polyester, so when they are added together, it has a better effect on improving dyeing performance, and little effect on other properties of the fiber, which will not affect its processing and mechanical properties.

(23) Comparison 4

(24) A method for preparing a modified polyester FDY involves steps basically the same as those in Example 1, except for adding dodecane-1,2-diol instead of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol in step (1). The prepared modified polyester FDY possess the performance indices of monofilament fineness 0.5 dtex, breaking strength 3.7 cN/dtex, elongation at break 36.0%, interlacing degree 18/m, linear density deviation rate 0.9%, breaking strength CV value 4.0%, breaking elongation CV value 7.5%, boiling water shrinkage rate 7.0%, and 288 modified polyester FDY in a bunch of filaments; under the same conditions as in Example 1, it has a dye uptake rate of 85.6% (at 120° C.), and its K/S value is 21.52.

(25) Compared with Example 1, it is shown that the tert-butyl in 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is more conducive to improve the dyeing performance of the fiber than the long-chain branched substituent in dodecane-1,2-diol. On one hand, it is because that the tert-butyl in 2,2,3,4,5,5-hexamethyl-3,4-hexanediol increases the free volume of the void, while the long-chain branched substituent in dodecane-1,2-diol increases the free volume of the slit. On the other hand, the rigidity of the tert-butyl in 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is higher than the rigidity of the long-chain branched substituent in dodecane-1,2-diol, reducing the entanglement between the molecular chains, so that 2,2,3,4,5,5-hexamethyl-3,4-hexanediol has more free volume than dodecane-1,2-diol in the molecular chain arrangement, which is more conducive to the dyeing performance of the fiber.

(26) Comparison 5

(27) A method for preparing a modified polyester FDY involves steps basically the same as those in Example 1, except for adding 1,6-hexanediol instead of dimethylsiloxane diol in step (1). The prepared modified polyester FDY possess the performance indices of monofilament fineness 0.5 dtex, breaking strength 3.7 cN/dtex, elongation at break 35.0%, interlacing degree 18/m, linear density deviation rate 0.9%, breaking strength CV value 4.0%, breaking elongation CV value 7.5%, boiling water shrinkage rate 7.0%, and 288 modified polyester FDY in a bunch of filaments; under the same conditions as in Example 1, it has a dye uptake rate of 85.7% (at 120° C.), and its K/S value is 21.44.

(28) Compared with Example 1, it is shown that —Si—O—Si— bonds will formed in main chain of polymer by introducing the main chain silicated diol, so that the silicon-oxygen bond gap is relatively long and the internal rotation activation energy is rather low, which is conducive to the free rotation of atoms, thereby increasing the free volume of the void, improving the dyeing performance of the fiber better than the long-chain branched substituent.

Example 2

(29) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(30) (1) Preparation of modified polyester;

(31) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(32) (1.1.1) evenly mixing a 0.5 mol % of Ca(NO.sub.3).sub.2 aqueous solution and a 5 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 1:100 of molar ratio of Ca.sup.2+ and Sb.sup.3+;

(33) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 10, then washing and drying (110° C., 2 h) the precipitate;

(34) (1.1.3) after the treatment composed of a heating at 400° C. for 2 h, a heating at 900° C. for 1 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.4 μm;

(35) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 11% mass concentration of hydrogen peroxide solution and reacting at 70° C. for 4 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:1.8:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(36) (1.3) Esterification

(37) concocting terephthalic acid, ethylene glycol, dimethyldiphenyldisiloxane glycol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:1.2, the total addition of dimethyldiphenyldisiloxane glycol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 2:1 is 6 mol % relative to the amount of terephthalic acid), and adding in 0.012 wt % of the doped Sb.sub.2O.sub.3 powder, 0.25 wt % of titanium dioxide and 0.01 wt % of trimethyl phosphate (all are relative to the amount of terephthalic acid), then carrying out the esterification under an atmospheric pressure of nitrogen pressure at 250° C., finally ending the reaction when the water distillation rate reaches 94% of the theoretical value;

(38) (1.4) Polycondensation after smoothly reducing the pressure from normal value to 490 Pa within 30 min, conducting the low vacuum polycondensation for the esterification products at 250° C. for 30 min, then further reducing the pressure to 90 Pa and continuing the high vacuum polycondensation at 270° C. for 50 min, finally obtaining the modified polyester with a molecular weight of 25000 Da and a molecular weight distribution index of 1.8;

(39) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 295° C.), cooling (at 22° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.30 MPa, first godet roller speed 2700 m/min, first godet roller temperature 90° C., second godet roller speed 4200 m/min, second godet roller temperature 140° C.), and winding (4120 m/min).

(40) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.32 dtex, breaking strength 3.55 cN/dtex, elongation at break 27.0%, interlacing degree 13/m, linear density deviation rate 0.95%, breaking strength CV value 4.8%, breaking elongation CV value 8.8%, boiling water shrinkage rate 6.9%, and 150 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 92.8% (at 120° C.), and its K/S value is 25.43.

Example 3

(41) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(42) (1) Preparation of modified polyester;

(43) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(44) (1.1.1) evenly mixing a 1.0 mol % of Ba(NO.sub.3).sub.2 aqueous solution and a 10 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 3:100 of molar ratio of Ba.sup.2+ and Sb.sup.3+;

(45) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 9.5, then washing and drying (105° C., 3 h) the precipitate;

(46) (1.1.3) after the treatment composed of a heating at 400° C. for 3 h, a heating at 900° C. for 2 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.5 μm;

(47) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 12% mass concentration of hydrogen peroxide solution and reacting at 74° C. for 4 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:1.6:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(48) (1.3) Esterification

(49) concocting terephthalic acid, ethylene glycol, tetramethyldisiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:2.0, the total addition of tetramethyldisiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 1:1 is 5 mol % relative to the amount of terephthalic acid), and adding in 0.0125 wt % of the doped Sb.sub.2O.sub.3 powder, 0.22 wt % of titanium dioxide and 0.05 wt % of trimethyl phosphite (all are relative to the amount of terephthalic acid), then carrying out the esterification under a 0.25 MPa of nitrogen pressure at 255° C., finally ending the reaction when the water distillation rate reaches 97% of the theoretical value;

(50) (1.4) Polycondensation

(51) after smoothly reducing the pressure from normal value to 495 Pa within 50 min, conducting the low vacuum polycondensation for the esterification products at 260° C. for 30 min, then further reducing the pressure to 90 Pa and continuing the high vacuum polycondensation at 270° C. for 50 min, finally obtaining the modified polyester with a molecular weight of 26000 Da and a molecular weight distribution index of 1.9;

(52) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 290° C.), cooling (at 20° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.25 MPa, first godet roller speed 2500 m/min, first godet roller temperature 85° C., second godet roller speed 4100 m/min, second godet roller temperature 132° C.), and winding (4000 m/min).

(53) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.4 dtex, breaking strength 3.7 cN/dtex, elongation at break 30.0%, interlacing degree 15/m, linear density deviation rate 0.9%, breaking strength CV value 4.5%, breaking elongation CV value 8.0%, boiling water shrinkage rate 6.6%, and 220 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 90.1% (at 120° C.), and its K/S value is 23.90.

Example 4

(54) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(55) (1) Preparation of modified polyester;

(56) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(57) (1.1.1) evenly mixing a 0.6 mol % of Zn(NO.sub.3).sub.2 aqueous solution and a 6 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 1.2:100 of molar ratio of Zn.sup.2+ and Sb.sup.3+;

(58) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 10, then washing and drying (110° C., 2.5 h) the precipitate;

(59) (1.1.3) after the treatment composed of a heating at 400° C. for 2.5 h, a heating at 900° C. for 1 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.4 μm;

(60) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 13% mass concentration of hydrogen peroxide solution and reacting at 74° C. for 3.5 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:1.5:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(61) (1.3) Esterification

(62) concocting terephthalic acid, ethylene glycol, tetramethyldisiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:1.5, the total addition of tetramethyldisiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 1:1.5 is 6 mol % relative to the amount of terephthalic acid), and adding in 0.013 wt % of the doped Sb.sub.2O.sub.3 powder, 0.25 wt % of titanium dioxide and 0.03 wt % of triphenyl phosphate (all are relative to the amount of terephthalic acid), then carrying out the esterification under an atmospheric pressure of nitrogen pressure at 257° C., finally ending the reaction when the water distillation rate reaches 95% of the theoretical value;

(63) (1.4) Polycondensation

(64) after smoothly reducing the pressure from normal value to 495 Pa within 35 min, conducting the low vacuum polycondensation for the esterification products at 255° C. for 35 min, then further reducing the pressure to 90 Pa and continuing the high vacuum polycondensation at 270° C. for 40 min, finally obtaining the modified polyester with a molecular weight of 27000 Da and a molecular weight distribution index of 2.0;

(65) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 295° C.), cooling (at 20° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.22 MPa, first godet roller speed 2500 m/min, first godet roller temperature 85° C., second godet roller speed 4200 m/min, second godet roller temperature 130° C.), and winding (3940 m/min).

(66) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.3 dtex, breaking strength 3.5 cN/dtex, elongation at break 26.0%, interlacing degree 12/m, linear density deviation rate 1.0%, breaking strength CV value 5.0%, breaking elongation CV value 9.0%, boiling water shrinkage rate 6.0%, and 145 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 92.5% (at 120° C.), and its K/S value is 25.32.

Example 5

(67) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(68) (1) Preparation of modified polyester;

(69) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(70) (1.1.1) evenly mixing a 0.7 mol % of Mg(NO.sub.3).sub.2 aqueous solution and a 8 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 2:100 of molar ratio of Mg.sup.2+ and Sb.sup.3+;

(71) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 10, then washing and drying (110° C., 2.5 h) the precipitate;

(72) (1.1.3) after the treatment composed of a heating at 400° C. for 2.5 h, a heating at 900° C. for 2 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.5 μm;

(73) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 14% mass concentration of hydrogen peroxide solution and reacting at 71° C. for 3.5 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:1.7:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(74) (1.3) Esterification

(75) concocting terephthalic acid, ethylene glycol, dimethylsiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:1.6, the total addition of dimethylsiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 2:1.5 is 5 mol % relative to the amount of terephthalic acid), and adding in 0.0135 wt % of the doped Sb.sub.2O.sub.3 powder, 0.20 wt % of titanium dioxide and 0.035 wt % of triphenyl phosphate (all are relative to the amount of terephthalic acid), then carrying out the esterification under an atmospheric pressure of nitrogen pressure at 257° C., finally ending the reaction when the water distillation rate reaches 94% of the theoretical value;

(76) (1.4) Polycondensation

(77) after smoothly reducing the pressure from normal value to 490 Pa within 40 min, conducting the low vacuum polycondensation for the esterification products at 256° C. for 40 min, then further reducing the pressure to 90 Pa and continuing the high vacuum polycondensation at 275° C. for 90 min, finally obtaining the modified polyester with a molecular weight of 27000 Da and a molecular weight distribution index of 2.0;

(78) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 295° C.), cooling (at 22° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.20 MPa, first godet roller speed 2700 m/min, first godet roller temperature 80° C., second godet roller speed 4200 m/min, second godet roller temperature 125° C.), and winding (3940 m/min).

(79) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.37 dtex, breaking strength 3.7 cN/dtex, elongation at break 29.0%, interlacing degree 14/m, linear density deviation rate 0.93%, breaking strength CV value 4.6%, breaking elongation CV value 8.3%, boiling water shrinkage rate 6.4%, and 200 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 91.0% (at 120° C.), and its K/S value is 24.63.

Example 6

(80) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(81) (1) Preparation of modified polyester;

(82) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(83) (1.1.1) mixing a 0.8 mol % of Mg(NO.sub.3).sub.2 aqueous solution and a 0.8 mol % of Ca(NO.sub.3).sub.2 aqueous solution with a volume ratio of 1:1 to obtain an aqueous solution containing metal ions M.sup.x+, which is evenly mixed with a 8 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 2.5:100 of molar ratio of M.sup.x+ and Sb.sup.3+;

(84) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 10, then washing and drying (105° C., 3 h) the precipitate;

(85) (1.1.3) after the treatment composed of a heating at 400° C. for 3 h, a heating at 900° C. for 1.5 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.4 μm;

(86) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 15% mass concentration of hydrogen peroxide solution and reacting at 75° C. for 3 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:1.9:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(87) (1.3) Esterification

(88) concocting terephthalic acid, ethylene glycol, dimethyldiphenyldisiloxane glycol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:1.7, the total addition of dimethyldiphenyldisiloxane glycol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 1.5:1 is 5.5 mol % relative to the amount of terephthalic acid), and adding in 0.014 wt % of the doped Sb.sub.2O.sub.3 powder, 0.25 wt % of titanium dioxide and 0.04 wt % of trimethyl phosphate (all are relative to the amount of terephthalic acid), then carrying out the esterification under a 0.2 MPa of nitrogen pressure at 255° C., finally ending the reaction when the water distillation rate reaches 95% of the theoretical value;

(89) (1.4) Polycondensation

(90) after smoothly reducing the pressure from normal value to 490 Pa within 45 min, conducting the low vacuum polycondensation for the esterification products at 254° C. for 45 min, then further reducing the pressure to 90 Pa and continuing the high vacuum polycondensation at 282° C. for 70 min, finally obtaining the modified polyester with a molecular weight of 28500 Da and a molecular weight distribution index of 2.0;

(91) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 285° C.), cooling (at 17° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.30 MPa, first godet roller speed 2300 m/min, first godet roller temperature 80° C., second godet roller speed 4000 m/min, second godet roller temperature 125° C.), and winding (3940 m/min).

(92) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.33 dtex, breaking strength 3.55 cN/dtex, elongation at break 28.0%, interlacing degree 13/m, linear density deviation rate 0.95%, breaking strength CV value 4.7%, breaking elongation CV value 8.6%, boiling water shrinkage rate 6.6%, and 180 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 91.5% (at 120° C.), and its K/S value is 25.00.

Example 7

(93) A method for preparing an easy-to-dye porous modified polyester fiber, comprising the steps:

(94) (1) Preparation of modified polyester;

(95) (1.1) Preparation of doped Sb.sub.2O.sub.3;

(96) (1.1.1) mixing a 0.5 mol % of Mg(NO.sub.3).sub.2 aqueous solution, a 0.5 mol % of Ba(NO.sub.3).sub.2 aqueous solution and a 0.5 mol % of Ca(NO.sub.3).sub.2 aqueous solution with a volume ratio of 1:1:1 to obtain an aqueous solution containing metal ions M.sup.x+, which is evenly mixed with a 10 mol % of Sb.sub.2O.sub.3 oxalic acid solution, maintaining a 2:100 of molar ratio of M.sup.x+ and Sb.sup.3+;

(97) (1.1.2) depositing the mixed solution by adding 2 mol/L of ammonia water until pH value reaches 9, then washing and drying (108° C., 2.5 h) the precipitate;

(98) (1.1.3) after the treatment composed of a heating at 400° C. for 2.5 h, a heating at 900° C. for 2 h and a cooling in air, crushing the precipitate to obtain the doped Sb.sub.2O.sub.3 powder with an average size of 0.4 μm;

(99) (1.2) Synthesis of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which is the product of cooling, crystallization and refining of evenly mixed palladium acetate and di-tert-butyl dimethyl ethylene, adding a 13% mass concentration of hydrogen peroxide solution and reacting at 73° C. for 3.4 h, wherein the mass ratio of di-tert-butyl dimethyl ethylene, hydrogen peroxide solution and palladium acetate is 1:1.8:0.015, and the structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is shown in Formula (I);

(100) (1.3) Esterification

(101) concocting terephthalic acid, ethylene glycol, dimethylsiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol into a slurry (in which the molar ratio of terephthalic acid and ethylene glycol is 1:2.0, the total addition of dimethylsiloxane diol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol with a molar ratio of 1:1 is 6 mol % relative to the amount of terephthalic acid), and adding in 0.014 wt % of the doped Sb.sub.2O.sub.3 powder, 0.25 wt % of titanium dioxide and 0.04 wt % of trimethyl phosphate (all are relative to the amount of terephthalic acid), then carrying out the esterification under a 0.3 MPa of nitrogen pressure at 260° C., finally ending the reaction when the water distillation rate reaches 94% of the theoretical value;

(102) (1.4) Polycondensation

(103) after smoothly reducing the pressure from normal value to 495 Pa within 40 min, conducting the low vacuum polycondensation for the esterification products at 260° C. for 50 min, then further reducing the pressure to 90 Pa and continuing the high vacuum polycondensation at 278° C. for 65 min, finally obtaining the modified polyester with a molecular weight of 28200 Da and a molecular weight distribution index of 2.2;

(104) (2) Spinning through a porous spinneret with FDY process including stages of metering, spinneret extruding (at 295° C.), cooling (at 20° C.), oiling, stretching as well as heat setting (carried on with the parameters of interlacing pressure 0.25 MPa, first godet roller speed 2700 m/min, first godet roller temperature 80° C., second godet roller speed 4050 m/min, second godet roller temperature 135° C.), and winding (4120 m/min).

(105) The prepared easy-to-dye porous modified polyester fiber has the performance indices of monofilament fineness 0.32 dtex, breaking strength 3.52 cN/dtex, elongation at break 26.5%, interlacing degree 13/m, linear density deviation rate 0.82%, breaking strength CV value 4.9%, breaking elongation CV value 8.8%, boiling water shrinkage rate 6.2%, and 160 modified polyester FDY in a bunch of filaments; wherein the easy-to-dye porous modified polyester fiber has a dye uptake rate of 92.0% (at 120° C.), and its K/S value is 25.23.