THE HIGH-UNIFORMITY COLOURED POLYESTER INDUSTRIAL YARN

Abstract

A high uniformity coloured polyester industrial yarn and preparation method. The raw material of the high-uniformity coloured polyester industrial yarn is the modified polyester composed of terephthalic acid segment, an ethylene glycol segment and a branched diol. The high-uniformity coloured polyester industrial yarn is prepared by esterification reaction of terephthalic acid with a branched diol using concentrated sulfuric acid as catalyst to obtain terephthalic acid glycol ester. Terephthalic acid and ethylene glycol are formulated to carry out esterification reaction to obtain ethylene terephthalate. Finally, stir and mix the two materials and carry out the polycondensation reaction in the low vacuum stage and the high vacuum stage under the action of the catalyst and the stabilizer to obtain modified polyester. Measure the modified polyester and add black masterbatch. After porous spinneret extrusion, cooling, oiling, drawing, heat setting and winding the modified polyester, high uniformity coloured polyester industry yarn is obtained.

Claims

1. A high-uniformity coloured polyester industrial yarn, wherein the high-uniformity coloured polyester industrial yarn is a polyester industrial yarn added with a black masterbatch, the high-uniformity coloured polyester industrial yarn is obtained by spinning after carrying out a solid phase polycondensation, the high uniformity coloured polyester industrial yarn comprises a modified polyester, wherein the modified polyester is composed of a terephthalic acid segment, an ethylene glycol segment and a branched diol segment, the branched diol segment is a diol having a branched chain, the branched chain is a non-terminal carbon in the ethylene glycol segment and the branched chain has a linear carbon chain containing 5 to 10 carbon atoms, the high-uniformity coloured polyester industrial yarn has a breaking strength 7.0 cN/dtex, a linear density deviation rate 1.0%, and a breaking strength CV value 2.0%; a CV value of elongation at break is 5.5%, a melt viscosity of the high uniformity coloured polyester industrial yarn is reduced by 10-20% at a temperature of 260-290 C.; and when a test condition is 177 C.10 min0.05 cN/dtex, a dry heat shrinkage ratio is 2.50.5%, and a melt viscosity drop is a comparison of the melt viscosity of the modified polyester and a common polyester at a same temperature.

2. The high-uniformity coloured polyester industrial yarn according to claim 1, wherein the high-uniformity coloured polyester industrial yarn has an elongation at break of 12.01.5%; a number average molecular weight of the modified polyester ranges from 15,000 to 30,000.

3. The high-uniformity coloured polyester industrial yarn according to claim 1, wherein the branched diol segment is one or more items selected from the group consisting of a 2-pentyl-1,3 propanediol segment, a 2-hexyl-1,3 propanediol segment, a 2-heptyl-1,3 propanediol segment, a 2-octyl-1.3 propanediol segment, a 2-mercapto-1,3 propanediol segment, a 2-mercapto group-1,3 propanediol segment, a 2-pentyl-1,4 butanediol segment, a 2-hexyl-1,4 butanediol segment, a 2-heptyl-1,4 butanediol segment, a 2-octyl-1,4 butanediol segment, a 2-mercapto-1,4 butanediol segment, a 2-mercapto-1,4 butanediol segment, a 2-pentyl-1,5 pentanediol segment, a 2-hexyl-1,5-pentanediol segment, a 2-heptyl-1,5-pentanediol segment, a 2-octyl-1,5-pentanediol segment, a 2-mercapto group-1,5 pentanediol glycol segment, a 2-mercapto-1,5 pentanediol segment, a 2-pentyl-1,6 hexanediol segment, a 2-hexyl-1,6 hexanediol segment, a 2-heptyl-1,6-hexanediol segment, a 2-octyl-1,6-hexanediol segment, a 2-mercapto-1,6-hexanediol segment and a 2-mercapto-1,6 hexanediol segment; and a molar percentage of the branched diol segment to the ethylene glycol segment ranges from 2% to 5%.

4. A method for preparing the high-uniformity coloured polyester industrial yarn of claim 1, wherein the modified polyester is subjected to the solid phase polycondensation, metering, and adding the black masterbatch; after porous spinneret extrusion by a porous spinneret cooling, oiling, drawing, heat setting and winding to obtain the high uniformity coloured polyester industrial yarn; the arrangement of the orifices on the porous spinneret is elliptical; the elliptical arrangement means that the centers of the orifices are located on concentric ellipses, and the concentric ellipses are a series of ellipses, and the long axes of all the ellipses are collinear, and the short axes of all the ellipses are collinear; a method for preparing the modified polyester includes the following steps: (1) preparation of terephthalic acid glycol ester: mixing terephthalic acid and the branched hexanediol to a first slurry, and carrying out a first esterification reaction under a catalytic action of concentrated sulfuric acid to obtain the terephthalic acid glycol ester; (2) preparation of ethylene terephthalate: mixing the terephthalic acid and ethylene glycol to a second slurry, carrying out a second esterification reaction to obtain the ethylene terephthalate; (3) preparation of the modified polyester: after the second esterification reaction in the step (2) is completed, adding the terephthalic acid glycol ester prepared in the step (1), stirring and mixing, performing a polycondensation reaction under the action of the catalyst and the stabilizer, and under a condition of a negative pressure; first in a low vacuum stage and then in a high vacuum stage to obtain the modified polyester.

5. The method for preparing the high-uniformity coloured polyester industrial yarn of claim 4, wherein, in the method for preparing the modified polyester the first slurry in the step (1) is added to a first reactor for carrying out the first esterification reaction; the first esterification reaction is carried out under a pressurized nitrogen environment, and the pressure is in a range of a normal pressure to 0.3 MPa, and a temperature is 180-240 C.; the first esterification reaction ends when a water distillation amount in the fast esterification reaction reaches at least 90% of a first theoretical value; then the terephthalic acid glycol ester is obtained; the second slurry in the step (2) is added into a second reactor for carrying out the second esterification reaction; the second esterification reaction is carried out under a pressurized nitrogen environment, and the pressure is in a ran e of normal pressure to 0.3 MPa, and a temperature is 250-260 C.; the second esterification reaction ends when a water distillation amount in the second esterification reaction reaches at least 90% of a second theoretic; then the ethylene terephthalate is obtained; in step (3) the stirring and mixing is performed for 15-20 minutes under the action of the catalyst and the stabilizer, and the negative pressure; in the polycondensation reaction under the condition of the low-vacuum stage, the pressure is smoothly pumped from the normal pressure to an absolute pressure under 500 Pa, a temperature is controlled at the temperature of 260-270 C., and a reaction time is 30-50 minutes; then turn to the high vacuum stage, the polycondensation reaction continues and the reaction pressure is reduced to an absolute pressure of less than 100 Pa, and the reaction temperature is controlled at the temperature of 275 to 280 C., and the reaction time is 50 to 90 minutes in order to obtain the modified polyester; obtaining modified polyester chips by granulate the modified polyester and carrying out the solid phase polycondensation of the modified polyester chips in order to make an inherent viscosity of the modified polyester increase to 1.0-1.2 dL/g to form a high-viscosity chip; after measuring, adding the black masterbatch, the extrusion of porous spinneret, cooling oiling, stretching, heat setting and winding, the high-uniformity coloured polyester industrial yarn is obtained; a mass ratio of the black masterbatch to the modified polyester chips ranges from 0.01%-0.03%; spinning process parameters of the high-uniformity coloured polyester industrial yarn are as follows: an extrusion temperature is 290-320 C.; a wind temperature is 20-30 C.; a winding speed is 2600-3200 m/min.

6. The method for preparing the high-uniformity coloured polyester industrial yarn of claim 5, wherein, in step (1), a molar ratio of the terephthalic acid to the branched diol is 1:1.3-1.5; an amount of the concentrated sulfuric acid added is 0.3-0.5% of a weight of the terephthalic acid; a concentration of concentrated sulfuric acid is 50-60 wt %; in step (2), a molar ratio of the terephthalic acid to the ethylene glycol is 1:1.2-2.0; in step (3), a molar percentage value of the diol terephthalate and the ethylene terephthalate is 2-5%; the catalyst is antimony trioxide, antimony glycol or antimony acetate, and an amount of catalyst added is 0.01%-0.05% of the total weight of the terephthalic acid; the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite, and an amount of stabilizer added is 0.01%-0.05% of the total weight of the terephthalic acid; a number average molecular weight of the modified polyester ranges from 15000-30000.

7. The method for preparing the high-uniformity coloured polyester industrial yarn according to claim 5, wherein the branched diol is one or more selected from the group consisting of a 2-pentyl-1,3 propanediol, a 2-hexyl-1,3 propanediol, a 2-heptyl-1,3 propanediol, a 2-octyl-1.3 propanediol, a 2-mercapto-1,3 propanediol, a 2-mercapto group-1,3 propanediol, a 2-pentyl-1,4 butanediol, a 2-hexyl-1,4 butanediol, a 2-heptyl-1,4 butanediol, a 2-octyl-1,4 butanediol, a 2-mercapto-1,4 butanediol, a 2-mercapto-1,4 butanediol, a 2-pentyl-1,5 pentanediol, a 2-hexyl-1,5-pentanediol, a 2-heptyl-1,5-pentanediol, a 2-octyl-1,5-pentanediol, a 2-mercapto group-1,5 pentanediol glycol, a 2-mercapto-1,5 pentanediol, a 2-pentyl-1,6 hexanediol segment, a 2-hexyl-1,6 hexanediol, a 2-heptyl-1,6-hexanediol, a 2-octyl-1,6-hexanediol, a 2-mercapto-1,6-hexanediol and a 2-mercapto-1,6 hexanediol.

8. The preparation method of the high uniformity coloured polyester industrial yarn according to claim 4, wherein the spinneret is a circular spinneret or an elliptical spinneret; a difference between a diameter of the circular spinneret and a maximum length of the long axis of the series ellipse is greater than 10 mm, and a difference value between the elliptical spinneret and the maximum length of the long axis of the series ellipse is greater than 10 mm.

9. The preparation method of the high-uniformity coloured polyester industrial yarn according to claim 4, wherein the arrangement of the spinneret holes is long axis and/or short axis symmetry; a ratio of the length the long axis of the ellipse to the length of the short axis of the ellipse ranges from 1.3-1.8; a spacing of the adjacent spinneret holes is greater than a diameter of a guide hole of the spinneret hole plus 1.5 mm.

10. The method for preparing a high-uniformity coloured polyester industrial yarn according to claim 2, wherein the guide hole diameter of the spinneret ranges from 1.5-2.5 mm; the number of spinneret holes is greater than or equal to 192, and the cross-section shape of the spinneret spinning hole is a circle, square, diamond, linear shape, triangle, trilobal shape, hollow type or flat type.

11. The method for preparing a high-uniformity coloured polyester industrial yarn according to claim 4, wherein the high-uniformity coloured polyester industrial yarn has an elongation at break of 12.01.5%; a number average molecular weight of the modified polyester ranges from 15,000 to 30,000.

12. The method for preparing a high-uniformity coloured polyester industrial yarn according to claim 4, wherein the branched diol segment is one or more items selected from the group consisting of a 2-pentyl-1,3 propanediol segment, a 2-hexyl-1,3 propanediol segment, a 2-heptyl-1,3 propanediol segment, a 2-octyl-1,3 propanediol segment, a 2-mercapto-1,3 propanediol segment, a 2-mercapto group-1,3 propanediol segment, a 2-pentyl-1,4 butanediol segment, a 2-hexyl-1,4 butanediol segment, a 2-heptyl-1,4 butanediol segment, a 2-octyl-1,4 butanediol segment, a 2-mercapto-1,4 butanediol segment, a 2-mercapto-1,4 butanediol segment, a 2-pentyl-1,5 pentanediol segment, a 2-hexyl-1,5-pentanediol segment, a 2-heptyl-1,5-pentanediol segment, a 2-octyl-1,5-pentanediol segment, a 2-mercapto group-1,5 pentanediol glycol segment, a 2-mercapto-1,5 pentanediol segment, a 2-pentyl-1,6 hexanediol segment, a 2-hexyl-1,6 hexanediol segment, a 2-heptyl-1,6-hexanediol segment, a 2-octyl-1,6-hexanediol segment, a 2-mercapto-1,6-hexanediol segment and a 2-mercapto-1,6 hexanediol segment; and a molar percentage of the branched diol segment to the ethylene glycol segment ranges from 2% to 5%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1 is an elliptical arrangement diagram of 374 spinnerets, the orifice diameter is 2.0 mm, and the length ratio of the long axis of the ellipse to the short axis is 1.3.

[0055] FIG. 2 is a circular arrangement diagram of 370 orifices, the orifice diameter is 2.0 mm;

[0056] FIG. 3 is an elliptical arrangement of 382 spinnerets with a hole diameter of 2.0 mm and a length ratio of the long axis to the short axis of 1.6.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] Hereinafter, the present invention will be described in more detail by the following examples. It should be noticed that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. In addition, it should be noticed that after reading the content of the present invention, those skilled in this field can make various modifications or changes to the present invention, and these equivalent forms also apply to the scope of the appended Claims of this application.

Examples 1-28

[0058] A preparation method of a modified polyester, including the following steps:

[0059] (1) Preparation of Terephthalic Acid Glycol Esters:

[0060] Add the terephthalic acid and B at a molar ratio of A as a mixture into the reactor at a concentration of C wt %, and the amount added is D % by weight of terephthalic acid. Under the catalysis of sulfuric acid, the esterification reaction is carried out. The esterification reaction is pressurized to E MPa under a nitrogen environment, the pressure is normal pressure, the temperature is F C. The esterification reaction ends until the water distillation amount in the esterification reaction reaches G % of the theoretical value, and the terephthalic acid glycol ester is obtained.

[0061] (2) Preparation of Ethylene Terephthalate:

[0062] The terephthalic acid and ethylene glycol having a molar ratio of H are mixed into the reactor, and then the esterification reaction is carried out. The esterification reaction is pressurized to 1 MPa under a nitrogen environment, and a temperature of F C. When the water distillation amount in the esterification reaction reaches K % of the theoretical value, the esterification reaction ends, and ethylene terephthalate is obtained;

[0063] (3) Preparation of Modified Polyester:

[0064] Add the terephthalate diol phthalate ester diol prepared in step (1) after completion of the esterification reaction in step (2). The molar percentage of terephthalate diol phthalate ester diol and ethylene glycol terephthalate is of L %. Stir and mix for M minutes. Add N % of O as catalyst in a total amount of terephthalic acid and P % of Q as stabilizer in a total amount of terephthalic acid. The polycondensation reaction in the low vacuum phase is started under the condition of negative pressure. The pressure is smoothly pumped from atmospheric pressure to an absolute pressure of R Pa, the temperature is controlled at S C., and the reaction time is T minutes, then the vacuum is continued for the high vacuum phase. The polycondensation reaction is carried out to reduce the reaction pressure to an absolute pressure of U Pa, the reaction temperature is controlled at V C., and the reaction time is W minutes. Then we can obtain the modified polyester.

[0065] The modified polyester obtained has a number average molecular weight of X and consists of terephthalic acid segment, ethylene glycol segment and branched B segment. The molar percentage of branched B segment and the ethylene glycol segment is y %.

[0066] The parameters of the variation in the different examples are shown in the following table. In the table, BA stands for 2-pentyl-1,3 propanediol, BB stands for 2-hexyl-1,3 propanediol, and BC stands for 2-Heptyl-1,3 propanediol, BD stands for 2-octyl-1,3 propanediol, BE stands for 2-mercapto-1,3 propanediol, and BF stands for 2-mercapto-1,3 propylene glycol, BG stands for 2-pentyl-1,4 butanediol, BH stands for 2-hexyl-1,4 butanediol, and BI stands for 2-heptyl-1,4 The diol, BT stands for 2-octyl-1,4 butanediol, BK stands for 2-mercapto-1,4 butanediol, and BL stands for 2-mercapto-1,4 Butanediol, BM stands for 2-pentyl-1,5-pentanediol, BN stands for 2-hexyl-1,5-pentanediol, and BO stands for 2-heptyl-1,5 Pentyl glycol, BP stands for 2-octyl-1,5 pentanediol, BQ stands for 2-mercapto-1,5 pentanediol, and BR stands for 2-mercapto-1,5 pentanediol, BS represents 2-pentyl-1,6 hexanediol, BT represents 2-hexyl-1, 6 hexanediol, and BU represents 2-heptyl-1,6 hexanediol, BV stands for 2-octyl-1,6 hexanediol, BW stands for 2-mercapto-1,6-hexanediol, BX represents 2-mercapto-1,6-hexanediol, OA stands for antimony trioxide, OB stands for ethylene glycol, and OC stands for Barium acetate, QA stands for triphenyl phosphate, QB stands for trimethyl phosphate, and QC stands for trimethyl phosphite, and the ratio is molar ratio.

TABLE-US-00001 TABLE 1 parameters of the variation in the different examples EX- AM- PLE A B C D E F G H I J K L M N O P Q R S T U V W X Y 1 1:1.3 BA 50 0.3 0.1 180 90 1:1.2 0.1 250 90 2 15 0.01 OA 0.01 QA 500 260 30 100 275 50 15000 2 2 1:1.38 BB 55 0.32 0.13 181 91 1:1.3 0.12 251 91 2.1 16 0.011 OA 0.02 QA 490 262 31 99 276 51 16000 2.1 3 1:1.33 BC 55 0.33 0.12 183 92 1:1.31 0.31 252 92 2.2 16 0.03 OA 0.02 QA 498 263 32 80 277 57 15900 2.2 4 1:1.34 BD 60 0.34 0.13 184 93 1:1.32 0.33 253 93 2.3 17 0.033 OA 0.023 QA 497 264 33 80 278 58 15800 2.3 5 1:1.35 BE 55 0.36 0.14 185 93.2 1:1.33 0.14 254 93.2 2.4 17 0.034 OA 0.024 QA 496 265 34 70 277 59 15900 2.4 6 1:1.36 BF 50 0.37 0.15 186 93.3 1:1.34 0.15 255 93.3 2.5 18 0.035 OA 0.025 QA 495 266 35 70 278 60 16000 2.5 7 1:1.37 BG 60 0.38 0.16 187 93.4 1:1.36 0.16 256 93.4 2.6 19 0.036 OA 0.025 QA 496 267 36 70 278 61 16000 2.6 8 1:1.38 BH 55 0.39 0.17 188 93.5 1:1.37 0.17 257 93.5 2.7 19 0.036 OA 0.025 QA 496 267 36 60 278 61 17000 2.7 9 1:1.39 BI 50 0.4 0.17 188 93.5 1:1.37 0.17 257 93.5 2.8 16 0.04 OB 0.026 QB 497 268 38 50 279 62 18000 2.8 10 1:1.4 BJ 55 0.4 0.17 188 93.5 1:1.38 0.18 257.8 93.6 3 17 0.03 OB 0.027 QB 498 269 39 50 278 64 19000 3 11 1:1.4 BK 55 0.4 0.18 189 93.6 1:1.39 0.19 258.8 94 4 18 0.04 OB 0.03 QB 497 260 40 40 277 63 20000 4 12 1:1.4 BL 55 0.4 0.2 200 94 1:1.6 0.2 256 94 4.5 18 0.038 OC 0.03 QC 497 265 42 40 277 70 26000 4 13 1:1.5 BM 60 0.5 0.3 240 92 1:2.0 0.3 260 92 5 20 0.05 OC 0.05 QC 450 270 50 30 280 90 30000 5 14 1:1.47 BN 60 0.47 0.28 220 92 1:1.8 0.27 258 92 4 18 0.04 OB 0.04 QB 460 263 47 40 278 85 28000 4 15 1:1.46 BO 60 0.49 0.28 233 92 1:1.8 0.28 259 92 4.5 19 0.044 OA 0.046 QA 490 269 48 40 279 87 29000 4.5 16 1:1.49 BP 60 0.48 0.28 230 92 1:1.8 0.28 258 92 4.7 19 0.048 OB 0.047 QA 460 267 48 40 279 83 27000 4.7 17 1:1.467 BQ 60 0.47 0.27 236 92 1:1.89 0.28 258 92 4.3 18 0.04 OA 0.041 QC 490 268 48 40 278 85 29000 4.3 18 1:1.48 BR 55 0.46 0.28 230 92 1:1.88 0.28 256 92 4.7 18 0.047 OA 0.047 QA 480 265 47 40 279 85 28000 4.7 19 1:1.46 BS 55 0.47 0.28 238 92 1:1.9 0.28 259 92 4.7 19 0.046 OC 0.048 QC 446 267 49 40 278 87 29000 4.7 20 1:1.46 BT 60 0.46 0.26 221 92 1:1.89 0.25 259 92 4.1 18 0.041 OB 0.042 QB 460 265 47 40 278 85 28000 4.1 21 1:1.43 BU 60 0.47 0.27 235 92 1:1.78 0.26 255 92 4.3 17 0.043 OA 0.049 QA 490 268 46 40 275 85 28000 4.3 22 1:1.43 BV 55 0.45 0.29 235 92 1:1.87 0.27 255 92 4.6 18 0.047 OB 0.04 QA 470 268 45 40 279 83 29000 4.6 23 1:1.457 BW 55 0.46 0.28 239 92 1:1.81 0.27 255 92 4.41 19 0.042 OA 0.048 QC 495 265 45 50 275 85 28000 4.41 24 1:1.47 BX 55 0.48 0.27 245 92 1:1.81 0.27 259 92 4.67 19 0.041 OA 0.042 QA 485 268 46 50 275 89 29000 4.67 25 1:1.45 BW + BG 55 0.49 0.26 236 92 1:1.8 0.28 258 92 4.4 18 0.042 OA 0.047 QC 495 265 49 50 278 88 29000 4.4 (3:1) 26 1:1.45 BO + BX 60 0.45 0.28 239 92 1:1.84 0.29 255 92 4.6 18 0.0423 OA 0.045 QC 495 265 45 50 278 85 28000 4.6 (3:2) 27 1:1.45 BW + BG 55 0.49 0.26 236 96 1:1.8 0.28 258 92 4.4 18 0.042 OA 0.047 QC 495 265 49 50 278 88 29000 4.4 (3:1) 28 1:1.45 BD + 60 0.47 0.29 235 92 1:1.8 0.27 258 92 4.71 18 0.04 OA 0.041 QC 490 268 49 50 277 84 29000 4.71 BG + BQ (3:2:1)

Example 29

[0067] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0068] As shown in FIG. 1 the ratio of the long axis to short axis of the ellipse is 1.3, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.5 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 1 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 2.0 mm. The number of spinning holes is 374, and the cutting shape of the micro spinning holes is circular.

[0069] After processing the modified polyester prepared in EXAMPLE 1 by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 290 C., the cooling wind temperature is 20 C., the winding speed is 2600 m/min, the added content of black masterbatch is of 0.01% of the mass of the modified polyester chips. The high-uniformity coloured industrial yarn has the breaking strength of 7.3 cN/dtex, the deviation of fiber density of 0.6%, the CV value of the breaking strength of 1.8%, the CV value of the elongation at break of 4.5%, and the elongation at break is 11.0. At the temperature of 260 C., the melt viscosity decreases by 11%. Under the condition of 177 C.10 min0.05 cN/dtex, the dry heat shrinkage rate is 2.5%.

Example 30

[0070] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0071] As shown in FIG. 3 the ratio of the long axis to short axis of the ellipse is 1.6, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.5 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 11 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 2.0 mm. The number of spinning holes is 382, and the cutting shape of the micro spinning holes is circular.

[0072] After processing the modified polyester prepared in EXAMPLE 1 by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 290 C., the cooling wind temperature is 20 C., the winding speed is 2600 m/min, the added content of black masterbatch is of 0.01% of the mass of the modified polyester chips. The high-uniformity coloured industrial yarn has the breaking strength of 7.2 cN/dtex, the deviation of fiber density of 0.7%, the CV value of the breaking strength of 1.7%, the CV value of the elongation at break of 4.8%, and the elongation at break is 11.0. At the temperature of 260 C., the melt viscosity decreases by 11%. Under the condition of 177 C.10 min0.05 cN/dtex, the dry heat shrinkage rate is 2.5%.

Comparative Example 1

[0073] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is circular. The circular arrangement refers to that the centres of spinning holes are on the concentric circles. The concentric circles are a series of circles. As shown in FIG. 2 the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.5 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 1 mm to the longest diameters of the series of circles. The diameter of guide holes of the spinning holes is 2.0 mm. The number of spinning holes is 370, and the cutting shape of the micro spinning holes is circular.

[0074] After processing the modified polyester prepared in EXAMPLE 1 by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 290 C., the cooling wind temperature is 20 C., the winding speed is 2600 m/min, the added content of black masterbatch is of 0.01% of the mass of the modified polyester chips. The high-uniformity coloured industrial yarn has the breaking strength of 7.6 cN/dtex, the deviation of fiber density of 1%, the CV value of the breaking strength of 1.9%, the CV value of the elongation at break of 5.3%, and the elongation at break is 12.0. At the temperature of 260 C., the melt viscosity decreases by 11%. Under the condition of 177 C.10 min0.05 cN/dtex, the dry heat shrinkage rate is 2.75%.

[0075] Compared to the EXAMPLE 29, we can draw the conclusion that when the effective areas of the spinneret are the same and the number of the spinning holes are similar (the number of spinning holes by circular arrangement is 370 and the number of spinning holes by elliptical arrangement is 374), the number of layers by elliptical arrangement is 5, smaller than that by circular arrangement which is 8, resulting in better cooling effects. The number of spinning holes by elliptical arrangements (382) is larger than that by circular arrangement (370), resulting in higher cooling efficiency. The result of comparison shows that, the deviation of fiber density. CV value of breaking strength, CV value of elongation at break in COMPARATIVE EXAMPLE 1 are all higher than those in EXAMPLE 29 and EXAMPLE 30, which means that under the same process conditions, the fiber obtained by spinneret using the elliptical arrangement has better fiber performance than that of the fiber obtained by spinneret using the circular arrangement.

Example 31-33

[0076] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0077] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 384, and the cutting shape of the micro spinning holes is square.

[0078] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 290 C., the cooling wind temperature is 30 C., the winding speed is 3100 m/min, the added content of black masterbatch is of 0.03% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00002 TABLE 2 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 31 Example 2 7.4 10 10 1.0 2.0 5.5 3 32 Example 3 7.5 11.5 15 0.6 1.8 4.6 2 33 Example 4 7.3 12.2 20 0.5 1.0 4.3 2.5

Example 34-36

[0079] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0080] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 192, and the cutting shape of the micro spinning holes is square.

[0081] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 290 C., the cooling wind temperature is 22 C., the winding speed is 3200 m/min, the added content of black masterbatch is of 0.02% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 290 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00003 TABLE 3 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 290 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 34 Example 5 7.4 10.0 10 0.8 1.8 4.0 2.6 35 Example 6 7.6 11.5 11 0.7 1.5 4.6 2.9 36 Example 7 7.4 13.4 16 0.6 1.4 4.8 2

Example 37-39

[0082] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0083] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 288, and the cutting shape of the micro spinning holes is square.

[0084] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 310 C., the cooling wind temperature is 28 C., the winding speed is 3000 m/min, the added content of black masterbatch is of 0.025% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 270 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00004 TABLE 4 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 270 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 37 Example 8 7.3 12.0 10 0.5 2.0 4.9 3 38 Example 9 7.4 13.2 18 0.7 1.8 4.6 2.7 39 Example 10 7.4 12.5 17 0.9 1.7 5.3 2.9

Example 40-42

[0085] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0086] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 192, and the cutting shape of the micro spinning holes is square.

[0087] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 300 C., the cooling wind temperature is 28 C., the winding speed is 3000 m/min, the added content of black masterbatch is of 0.02% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 260 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00005 TABLE 5 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 260 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 40 Example 10 7.2 11.0 10 0.5 2.0 5.0 2.7 41 Example 11 7.3 10.5 11 0.7 1.8 4.8 2.05 42 Example 12 7.5 13.5 11.7 0.6 1.4 4.6 2.8

Example 43-45

[0088] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0089] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 244, and the cutting shape of the micro spinning holes is square.

[0090] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 290 C., the cooling wind temperature is 30 C., the winding speed is 3100 m/min, the added content of black masterbatch is of 0.018% of the mass of the modified polyester chips. The high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00006 TABLE 6 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 43 Example 14 7.2 11.0 10 0.5 2.0 5.0 2.7 44 Example 15 7.3 10.5 11 0.7 1.8 4.8 2.05 45 Example 16 7.5 13.5 11.7 0.6 1.4 4.6 2.8

Example 46-48

[0091] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0092] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 192, and the cutting shape of the micro spinning holes is square.

[0093] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 310 C., the cooling wind temperature is 30 C., the winding speed is 3200 m/min, the added content of black masterbatch is of 0.018% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00007 TABLE 7 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 46 Example 17 7.3 10.5 10 0.5 2.0 4.0 2.7 47 Example 18 7.5 11.5 10 0.47 1.8 4.6 2.4 48 Example 19 7.3 12.1 11.7 0.46 1.7 5.3 2.2

Example 49-51

[0094] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0095] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 192, and the cutting shape of the micro spinning holes is square.

[0096] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 300 C., the cooling wind temperature is 25 C., the winding speed is 2800 m/min, the added content of black masterbatch is of 0.01% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00008 TABLE 8 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 49 Example 20 7.4 10.0 16 0.5 2.0 5.0 2.9 50 Example 21 7.3 11.5 15 0.8 1.8 4.6 2.0 51 Example 22 7.5 12.9 20 0.8 1.7 4.3 3.0

Example 52-57

[0097] In the preparation method of the high-uniformity coloured polyester industrial yarn, the high-uniformity coloured polyester industrial yarn is obtained by using the porous spinneret. The arrangement of the spinning holes on the spinneret is elliptical. The elliptical arrangement refers to that the centres of spinning holes are on the concentric ellipses. The concentric ellipses are a series of ellipses, all of which have the same long axis and the short axis.

[0098] The ratio of the long axis to short axis of the ellipse is 1.4, and the spacing between the neighbouring spinning holes equals to the diameter of the guide holes of the spinning holes plus 1.6 mm. The spinnerets are circle spinneret and the diameter of the spinnerets has a difference of 12 mm to the longest long axis of the series of ellipses. The diameter of guide holes of the spinning holes is 1.5 mm. The number of spinning holes is 192, and the cutting shape of the micro spinning holes is square.

[0099] After processing the modified polyester by solid phase polycondensation, measuring, adding black masterbatch, porous spinneret extrusion, cooling, oiling, stretching, heat setting, and winding, we can obtain the high-uniformity coloured polyester industrial yarn. The temperature of extrusion is 320 C., the cooling wind temperature is 30 C., the winding speed is 3000 m/min, the added content of black masterbatch is of 0.03% of the mass of the modified polyester chips. The high-uniformity coloured industrial yam's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C.10 min0.05 cN/dtex are shown in the table below.

TABLE-US-00009 TABLE 9 the high-uniformity coloured industrial yarn's mechanical properties, the melt viscosity drop rate at the temperature of 280 C., and the dry heat shrinkage rate of the industrial yarn under the condition of 177 C. 10 min 0.05 cN/dtex Melt fiber Modified Breaking viscosity density CV value of CV value of Dry heat polyester strength Elongation drop deviation breaking elongation shrinkage Example source (cN/dtex) at break (%) value (%) rate (%) strength (%) at break (%) rate (%) 52 Example 23 7.4 12.0 10 0.5 1.0 4.0 2 53 Example 24 7.3 10.5 11 0.47 1.8 4.6 2.8 54 Example 25 7.0 11.4 11.7 0.46 1.5 5.4 2.8 55 Example 26 7.4 21.0 10 0.5 2.0 5.3 2.7 56 Example 27 7.8 10.5 11 0.47 1.8 4.6 3.0 57 Example 28 7.3 12.1 11.7 0.46 1.7 5.2 2.9