DE1720647C2 - Process for the production of fiber and film-forming polyesters - Google Patents

Description

OH

It is known to have linear fiber and film structures Polyesters or mixed polyesters which are wholly or partly built up from aromatic dicarboxylic acids and diols lind, more corresponding by transesterification of lower alkyl esters Dicarboxylic acids with diols and polycondensation of the "precondensate" obtained in this way by heating to be produced in a vacuum. Both reaction stages, both the transesterification and the polycondensation, are greatly accelerated by the addition of catalysts. Short reaction times are preferred to prevent that - in particular due to the high polycondensation temperatures - chain termination Mnd Cleavage reactions become effective, as a result of which polyester with only a low degree of polycondensation and unsatisfactory color arise.

A large number of Known catalysts that catalyze either the transesterification or the polycondensation or both reaction stages (compare e.g. Review by R. E. WiIföng, Journal of Polymer Science, 54,385 [1961]).

However, these catalysts generally do not meet all requirements. A catalyst for that Production of linear, fiber and film-forming polyesters should be active and no side reactions such. B. Dehydration reactions or the thermal degradation or the degradation of the polyester in the Catalyze exposure to light. In addition, the polyesters should have the highest possible degree of whiteness.

It has now been found that linear, fiber and film-forming polyesters by polycondensation of Bis-hydroxyalkyl-dicarboxylic acid esters in the presence of silicon compounds as catalysts can advantageously be prepared when used as catalysts Esters and / or salts of compounds of the general formula

HO-P-CH ₁ -CH, -Si -OH-.VH ₁ O

I "" I

OH OH

in which χ 1.5 or a number below 1.5 or also the value O is used, the ester groups representing the radicals of lower aliphatic alcohols with 1 to 4 carbon atoms and the salt groups representing the ions of alkali metals.

OH

HO-P-CH ₂ -CH ₂ -Si-OH-XH ₂ O
OH OH

where χ 1.5 or a number below!, 5 or also the value O is used, the ester groups representing the radicals of lower aliphatic alcohols with 1 to 4 carbon atoms and the salt groups representing the ions of alkali metals.

As bis-hydroxyalkyl-dicarboxylic acid esters, all those bis-hydroxyalkyl-dicarboxylic acid esters used whose polycondensations produce fiber- and film-forming polyesters. Preferred acid components this bis-hydroxyalkyl-dicarboxylic acid ester are, for. B. terephthalic acid, isophthalic acid, 4,4-diphenyldicarboxylic acid, 2,5-dimethylterephthalic acid, 5-sulfoisophthalic acid, Bis-p-cnrboxyphenoxyethane, naphthalenedicarboxylic acid (-1.3, -1.4, -1.5, -2.6), hexahydroterephthalic acid and sebacic acid.

The alcohol components of the bis-hydroxyalkyldicarboxylic acid esters are glycols with preferably 2 to 10 carbon atoms, e.g. B. ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol and 2,2-dimethyl propanediol and cycloaliphatic diols such as 1,2-cyclobutanediol and -1,3, and 1,4-dimethylolcyclohexane. The polycondensation the bis-hydroxy-alkyl-dicarboxylic acid ester is increased in a manner known per se Temperature and carried out under reduced pressure.

Those polyesters are preferably produced in which more than 75% of their dicarboxylic acid units are made up of terephthalic acid units exist.

The representation of the esters and / or salts of silanetriol-ethanephosphonic acid used according to the invention and their condensation products are carried out according to known methods; for example, the Pentaalkyl ester according to the process of US Pat. No. 31 22 581 from a dialkyl phosphite and a Vinyl trialkoxysilane can be produced. When trying the representation of such esters and salts of silanetriolethane-phosphonic acid, which are free on the silicon atom Carrying hydroxyl groups, condensation of two or more molecules occurs with the escape of water higher molecular weight products with the formation of

- Si - O - Si bonds

because, as is well known, free silanols are hardly stable.

It is also possible that in one and the same molecule

various ester and salt groups, both ester and also salt groups and even ester, salt groups and one or two free OH groups on the phosphorus atom are present, e.g. B.

O OCH,

HO P _CH:, CH ₂ OCH Si,

ONa OCH,

CH ₃ O-

ΐ
-P-

OC ₂ H ₅
CH, - CH, - Si - OCH ₅

OCH,

OC ₂ H ₅

OCH ₃

Na-OP-CH ₂ -CH ₂ -Si-OCH ₃
ONa OCH ₃

O OK

τ ι

CH ₃ OP-CH ₂ -CH ₂ -Si-OK

OCH ₃

OK

O OCH, OCH, O

ΐ I 'I' T

NaO-P-CH ₁ -CH ₇ -Si-O-Si-CH ₁ -CH, -P-ONa

I * "I 1 ~ - ι

OCH ₃

OCH ₃ OCH ₃

OCH ₃

Suitable catalysts are ζ. B. Trimethoxysilanäthanphosphonsäurediethylester, Triäthoxysilanäthanphosphonsäurediethylester, Trimethoxysilanäthanphosphonsäuredimethylester, Tri-n-butoxysilanethane phosphonic acid di-n-butyl ester, the condensation products of silanetriol ethane monosodium phosphonate and of Silanetriol ethane disodium phosphonate.

Mixtures of the compounds mentioned can of course also be used.

The amount of catalysts in the polycondensation batch should preferably be such that O ₁ Ol to 0.1 percent by weight, based on bis-hydroxyalkyldicarboxylic acid ester, silicon is present.Dio liquid or pulverized solid catalysts are either as such or in solution or dispersion, preferably with the Diol, which also makes up the alcohol component of the bis-hydroxyalkyldicarboxylic acid ester to be condensed, is added to the polycondensation batch.

According to the invention, polyesters with high degrees of polycondensation are obtained in a short time are characterized by high melting points, a high degree of whiteness and good heat and light stability. It will furthermore a considerable increase in the melt viscosity of the polycondensates and a strong reduction in the Bending resistance of the threads produced from the polycondensates is achieved. These two effects together make it possible to produce fibers which can be processed into non-pilling tissues, i. H. Tissues that do not tend to form pebbles on the surface during use.

Compared to the use of the Belgian patent fi 67 089 as polycondensation catalysts known benzylsilanetriol-p-sulfonic acid derivatives the use of the polycondensation catalysts according to the invention produces an even stronger one Effect in terms of increasing the melt viscosity, reducing the pill tendency of the fiber and in particular to improve the dyeability of the threads and fibers. Another advantage of the invention consists in the fact that without the usual additions of compounds of trivalent phosphorus polyester can be obtained with a high degree of whiteness and good thermal stability. In addition, the catalysts are that are used according to the invention, easily and technically advantageous to manufacture.

S example 1

12 kg dimethyl terephthalate, 9 kg of ethylene glycol and 2.4 g of zinc acetate are heated with stirring in a V2A apparatus 2 '/ 2 hours under nitrogen, whereby the temperature of 160 ⁰ C to 215 ° C is increased. A transesterification product consisting essentially of bis - /? - hydroxyethyl terephthalate is formed with elimination of methanol. This precondensate obtained in this way is polycondensed after adding 48 g of trimethoxysilanethane phosphonic acid diethyl ester and 288 g of a 17 weight percent suspension of titanium oxide in ethylene glycol. For this purpose, the temperature is increased from 245 to 275 ° C. over the course of 2 hours, while stirring, and the pressure is simultaneously lowered to 1 Torr. After further heating at 275 ° C. and 0.6 Torr for 15 minutes, the viscous polycondensate is pressed through a single-hole nozzle, the wire obtained is quenched with water and cut into chips about 5 mm in length. The chips obtained have a softening point of 260.2 ° C and a relative viscosity of 1.695, measured on a 1 weight percent solution in phenol-tetrachloroethane 3: 2 (volume ratio) at 25 ⁰ C. at 8O ⁰ C at 40 Torr The four hours and 2 '/ 2 hours at 16O ⁰ C dried polycondensate showed a melt viscosity of 1405 poise, at a relative viscosity of the melt cake of 1,660 at 285 ° C. In contrast, a polyethylene terephthalate prepared using antimony trioxide as the polycondensation catalyst and having the same relative viscosity gave a melt viscosity of only 1045 poise.

The polyethylene terephthalate chips prepared and dried using the trimethoxysilanethanephosphonic acid diethyl ester catalyst are melted again and passed through an extruder through a 24-hole nozzle, hole diameter 0.25 mm, with a rate of 19.2 g / minute and a take-off of 500 m / minute spun at 280 ^{° C.}

The threads from 100 bobbins are combined to form a tow with a titer of about 2000. The Cable is then stretched in a ratio of 1: 4, with an infeed speed of 13.5 m a 2 m

long steam zone happened. After passing through two 2.40 m long iron with temperatures of 100 and 118 ° C is passed over the cable to a preparation roll and led to the drying on a 2.40 m long 140 ⁰ C hot iron. The tape will then

5 <i crimped and up according to the stuffer box method cut the lengths 65, 80 and 140 mm. The fiber thus obtained has a tensile strength of 3.2 g / den and an elongation at break of 60.7%. The remission values of the fiber measured according to the standard valent system DIN 5033 with the Zeiß-ELREFO device and the color measurement filters FMX-C, FMY-C, FMZ-C were:

Rx 76.8, Ry 75.6, Rz 72.6.

A jersey made from this fiber (0.4 denier / 75 M Nm 40/1, 505 Z, Wevenit binding, Monit 16-er Division) pills in the Random Tumble Pilling Tester from Atlas Electric Devices Co. (see ASTM Standard on Textile

Materials, 1961, p. 552, and Bulletin X 96 of DuPont Co, Wilmington / USA) not after IV2 hours, while a comparative fabric?. made of normal polyethylene terephthalate pilled heavily.

Example 2

12 kg of dimethyl terephthalate are after addition of 0.69 g of zinc acetate and 2.14 g of manganese (N) acetate with 9 kg of ethylene glycol, as described in Example 1, transesterified ethylene glycol is the transesterification product is polycondensed to this, the temperature is increased within 2 hours from 245 to 275 ° C and the pressure is simultaneously reduced to 1 torr After further I ³ A long hours heating at 278 ° C at 0.3 torr, the polycondensate is as in the Example 1 processed into schnitzel. The chips have a softening point of 261.5 ° C. and a relative viscosity of 1.718 measured as in Example 1. The polycondensate is then dried, spun and processed into fibers as described in Example 1. The fibers have a tensile strength of 3.1 g / den and an elongation at break of 31.8%.

The remission values of the fiber, measured according to the DIN 5033 standard valence system, were:

Rx 77.8, Ry 67A, Rs 73.8.

Example 3

To a transesterification product from 12 kg of dimethyl terephthalate, 9 kg of ethylene glycol and 2.4 g of zinc acetate - prepared according to Example 1 - are 288 g a 17 weight percent suspension of titanium dioxide in ethylene glycol and a solution of 48 g of an intermolecular cleavage of IV2 molecules Water resulting condensation product from / S-silanetriol-ethane-disodium phosphonate in 1 l of ethylene glycol! admitted. 48 g of ß-silanetriol ethane disodium phosphonate condensate are used to prepare this solution Dissolve in 500 ml of hot water, the solution is added to 1/2 liter of ethylene glycol, then is concentrated to 1 l under reduced pressure. This dissolution process is necessary because the ß-silanetriol-ethane-disodium-phosphonate condensate does not dissolve directly in the ethylene glycol.

For the polycondensation, the temperature is increased from 245 to 275 ° C. over the course of 2 hours, while stirring, and the pressure is simultaneously reduced to 1 Torr. Then at 275 ⁰ C and 0.3 Torr is further heated 3 ¹ A hours. The polycondensate is then, as described in Example 1, processed into schnitzel. The chips have a softening point of 260.7 ° C., a relative viscosity of 1.482 (measurement as in Example 1) and a melt viscosity of 810 poise. On the other hand, a normal polyethylene terephthalate with the same relative viscosity has a melt viscosity of 305 poise.

After drying and spinning as in Example 1 at a spinning temperature of 285 ⁰ C and stretching on a stretching machine Zinser in the ratio 1: the and an elongation at break is obtained threads 4 having a tenacity of 2.5 g / 27.1%. The mean break fracture number, determined according to KH Grünewald, Chemiefwissenschaften, Vol. 12, p. 853, 1962, is 415, while that of a normal polyethylene terephthalate fiber in the viscosity range 1.780 to 1.840, on the other hand, is 3000 to 3500.

The remission values of the fiber, measured according to the standard valence system DIN 5033, were:

Rx 90.8, Ry 90.7, Rz 85.9.

Example 4

A transesterification product of 12 kg of terephthalic acid dimethyl ester, 9 kg of ethylene glycol and 2.4 g of zinc acetate, prepared according to Example 1, is, after adding a solution of 48 g of a condensation product of 0-silanetriolethane di- produced by intermolecular cleavage of 1/2 molecules of water, sodium phosphonate in 11 ethylene glycol and 288 g of a 17 weight percent suspension of titanium dioxide in ethylene glycol polycondensed , 3 Torr, the poly condensate, as described in Example 1, is processed into schnitzel. The chips have a softening point of 260.3 ⁰ C and a relative viscosity of 1.472 (measured as in Example 1). The melt viscosity was 845 poise. In contrast, a comparative product of the same solution viscosity had a melt viscosity of 301 poise.

After drying and spinning according to Example 1 at a spinning temperature of 285 ° C. and drawing a Zinser stretching machine in a ratio of i: 4 results in threads with a tensile strength of 2.4 g / denier and an elongation at break of 27.1%. The mean number of buckling fractures (compare Example 3) is 245.

The remission values of the fiber, measured according to the DIN 5033 standard valence system, were:

Rx 90.3, Ry 90.2, Rz 86.7.

Example 5

To a 160 ° C. melt of 200 g of pure dry bis-j9-hydroxyethyl terephthalate a solution of 0.544 g of a water obtained by intermolecular splitting off of 1/2 molecules is added with stirring resulting condensation product of j? -silanetriol-ethane-disodium-phosphonate added in 25 ml of ethylene glycol. To prepare this solution, the salt is first dissolved in 50 ml of hot water, then 75 ml of ethylene glycol are added and finally concentrated to 25 ml under reduced pressure.

After addition of this solution is heated under nitrogen to 250 ⁰ C, the pressure gradually within 2 hours ³ A to less than 1 Torr lowered. The temperature is now increased to 278 ° C. over the course of 15 minutes and the mixture is heated at 0.3 torr for a further 4 hours. The obtained polyester has a softening point of 257 ⁰ C and a relative viscosity of 1.593 (measured as in Example 1).

Example 6

122.4 g of dimethyl terephthalate, 13.6 g of dimethyl isophthalate, 108.9 g of ethylene glycol and 0.0272 g of zinc acetate are heated from 160 to 210 ° C. ^{with stirring in 3 3 A hours until the elimination of methanol has ended.} The transesterification product obtained in this way is polycondensed after the addition of 0.5440 g of triethoxysilane ethane phosphonic acid diethyl ester and 3.2 g of a 1 / percent strength by weight suspension of titanium dioxide in ethylene glycol. These C is first heated under nitrogen to 250 ^0, wnhpi nrr di-nrl ·

is gradually ^{reduced within 2 3} A hours to below 1 Torr. The temperature is then increased to 278 ° C. within a short time, and finally heating is continued for a further 1 hour and 10 minutes at 0.5 torr. A colorless polycondensate with a softening point of 249 ° C. and a relative viscosity of 1.716 (measurement as in Example 1) is obtained.

Example 7

136.0 g of dimethyl terephthalate, 4.4 g of dimethyl isophthalate-5-sulfonic acid, 108.9 ethylene glycol and 0.0272 g of zinc acetate are heated from 160 ° C. to 210 ° C. ^{with stirring in 5 1 hours until the elimination of methanol is complete.} The transesterification product thus obtained is, after addition of 0.5440 g of triethoxysilane ethane phosphonic acid diethyl ester and 3.2 g of a 17% by weight suspension of titanium dioxide in ethylene glycol, as described in Example 6, polycondensed. After the temperature of 278 ° C. has been reached, heating is continued at 0.8 torr / a hours. The colorless polycondensate has a softening point of 225 ⁰ C and a relative viscosity of 1.915 (measured as in Example 1).

Example 8

A transesterification product of 12 kg of dimethyl terephthalate, 9 kg of ethylene glycol and 2.4 g of zinc acetate according to Example 1 is dissolved in 1 liter of ethylene glycol after adding 48 g of a condensation product of / 3-SiIantrioläthanmono-sodium phosphate formed by intermolecular elimination of 1 Ui molecules of water polycondensed. For this purpose, the temperature is first increased from 245 to 275 ° C. over the course of 2 hours and the pressure is simultaneously reduced to 1 Torr. Finally, heating is continued for 45 minutes at 275 ° C. and 0.5 torr. The polycondensate is processed into chips as in Example 1. The chips have a softening point of 260.7 ⁰ C and a relative viscosity of l, 559 (measured as in Example 1).

Example 9

593 g of dimethyl terephthalate, 475 g ethylene glycol and 0.1168 g of zinc acetate are heated with stirring 5Ά hours to complete the elimination of methanol from 160 to 210 ⁰ C. The transesterification product obtained in this way is after addition of 4.744 g of a mixture of approximately equal parts by weight of mono- and di-sodium salt of a condensation product of silanetriolethane phosphonic acid formed by intermolecular splitting off of l '/ 2 molecules of water as a 1.5% solution in ethylene glycol and 13.95 g of a 17 weight percent suspension of titanium dioxide in ethylene glycol, as described in Example 6, polycondensed. After the temperature of 278 ° C. has been reached, heating is continued for a further 1 hour and 50 minutes at 0.5 torr. A colorless polycondensate with a softening point of 258 ° C. and a relative viscosity of 1.509 (measurement as in Example 1) is obtained.

After crushing the polycondensate with a cross beater mill, the granules with a grain size of about 2 mm after 5 hours of drying at 150 ° C and 1 Torr using an extruder at 290 ⁰ C through a 24-hole nozzle, hole diameter 0.25 mm with a Conveyance of 18.3 g and a spinnabzuj of 1000 m / minute spun. The threads obtained in this way have, after stretching on the Zinser stretching machine in a ratio of 1 -.3.65, a tensile strength of 2.4 g / den and an elongation at break of 30.8%.

Buckling rupture resistance 148 strokes.

Claims (1)

Claim: Process for the production of fiber- and film-forming polyesters by polycondensation of bis-hydroxyaikyl-dicarboxylic acid esters in the presence of silicon compounds as catalysts, characterized in that the catalysts used are esters and / or salts of compounds the general formula