DE1520534A1 - Process for the production of linear polyesters - Google Patents

Description

Process for the preparation of linear polyesters "S The invention concerns the manufacture of linear polyesters.

The production of film and fiber-forming polyesters from terephthalic acid and a glycol of the series HO (CH2) nOH, wherein n is an integer from 2 to 10 inclusive means, is noted in US Patent 2 465 319. Bines the technically The most attractive polycondensate of this group is polyethylene terephthalate, which is produced by Transesterification of ethylene glycol with dimethyl terephthalate to form monomeric bis-2-hydroxyethyl rephthalate and subsequent polycondensation of this ester under reduced pressure at higher Temperatures in the presence of catalysts is produced.

. In the production of Polyäthylenterephtalfatfolien from after U.S. Patent 2,465,319 polycondensation product obtained will, the process steps (1) of the treatment of Gl @ kol with terephthalic acid dimothyl ester in the presence of a transesterification catalyst to monomeric bis-2-hydroxyethyl terephthalate, (2) the polycondensation of this best in the presence of a polycondensation catalyst to high molecular weight polyethylene terephthalate and (3) the Strangpwesen of the melt of the polycondensate to rolls preferably carried out continuously. This continuous way of working is, however, accompanied by difficulties. One the greatest difficulty is z. B. the formation of stripes or

Sehlieren in the film. These stripes appear from the exit vent the extrusion mold, where the polycondensate is deformed into a film. The appearance of similar stripes causes interruptions in operation for cleaning the Exit slot of the mold required. During these interruptions that muse Polymer can be tipped out, which means not only production time, but also material get lost.

Another difficulty is the unwanted color formation (yellowing) during the polycondensation stage, which is apparently the polyol condensation catalysts is attributable. The first of these difficulties can be overcome by adding a minor one Lack of ammonium phosphate or ammonium phosphite for the reaction, as mentioned in the polycondensation stage, are vermioden. In addition, such phosphorus-containing Compounds the insulation resistance of the polyester film and therefore its value ale dielectric material significantly increased. Although the Phoaphorverbindungen the Greatly improve the insulation resistance of the film, suppress color formation, practically keeping the banding in the film and thereby the loss of production time Avoid cleaning the strand prepaform, they have two important disadvantages with himself. It is known that monoammonium phosphate is associated with many gemchnin used catalysts reacts with the formation of solid precipitates. this leads (1) to a faster clogging of the filter device for the polycondensate, probably as to the conversion of the catalyst into effective ones For en, and @ to a lower polycondensation activity, which the generation of glycols limited.

These difficulties also arise in the manufacture of others linear polyesters.

It is known from US Pat. No. 2,989,499 that polycondensation to carry out in the production of linear polyesters with a catalyst that from the zinc salt of a solid acid and an organic phosphine, and de Polyester after its production an inorganic hypophosphite, like magnesium hypophosphite, add to improve the resistance of the products to degradation ou.

Tents 2,921,051 and 3,028,366 and the Loritian patent 769 220 describe the production of linear polyesters with the addition of phosphoric acid, phosphorous acid or esters of these acids. The addition of free acids to the reaction mixture but increases the electrical conductivity of the polyester and impairs such their color stability and the activity of the catalyst. On the other hand, can the esters of phosphoric acid or phosphorous acid easily become the free acids hydrolyze, which is what the same technical texts entail.

The invention is based on the object of a method for production of linear polyesters available with the disadvantages mentioned above do not occur and as a result polyesters with better electrical insulating properties and better color fastness can be obtained.

The invention is based on the idea that the disadvantages of the Avoid adding acids of phosphorus or esters hydrolyzable to acids could, if it were possible to find organic phosphorus compounds as additives the same advantages vis-à-vis the polycondensation chemistry on the one hand the On the other hand, organic phosphorus compounds known hitherto for this purpose but have such a constitution that it is nioht eo easily hydrolyzed to buron can be.

It has been found that this task can be achieved through the addition of organic Phosphonates can be elbot.

The inventive method for the production of linear polyester consists in that the polycondensation is carried out in the presence of at least 0.05 percent by weight, based on the amount of the alkyl ester used for transesterification, on one of the following organic phosphonates: (a) Compounds of the general formula in which one of the radicals R1, R2 or R3 is an alkyl, haloalkyl, hydroxyalkyl, aryl, aryloxy or alkenyl radical, while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, hydroxy-polyoxyalkylene, aryl, Are aryloxy or alkenyl radicals; (b) Compounds of the general formula in which R @ is a divalent organic radical and at least one radical of an éden group of radicals R1, R2 or R4 R5 is an alkyl, haloalkyl, hydroxyalkyl, aryl, alkenyl, haloalkenyl, hydroxyalkenyl or aryloxy radical, while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, aryloxy, aryl, alkenyl, haloalkenyl or hydroxyalkenyl radicals; (c) compounds of the general formula in which R3 and R5 are divalent organic radicals and at least one radical of each of the groups (1) R1, R2, (2) R4 or (3) R6, R7 is an alkyl, haloalkyl, hydroxyalkyl, aryl, aryloxy or Alkenyl radical, while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, aryl, aryloxy or alkenyl create; (d) by reacting an alkyl phosphite of the general formula in which R1, R2 and R3 denote alkyl radicals having 1 to 5 carbon atoms, with a compound of the general formula in which X represents a halogen atom or a hydrogen atom, products obtained; (e) by reacting an alkyl phosphonate of the general formula in which the radicals Rit R2 and R3 mean alkyl radicals, products obtained with a polymethylene glycol having 2 to 10 carbon atoms in the molecule.

The invention is also applicable to processes in which either (A) an alkyl ester of an aromatic dioarboxylic acid, the alkyl groups of which contain 1 to 7 carbon atoms, and a polymethylene glycol with 2 to 10 @@@ le @@ toffatonen in the molecule or (B ) an @@ s-hy @ rox @ alkyl group of an eromatic dicarboxylic acid or low molecular weight polycondensates of such esters with intrinsic viscosity alight over 0.2 can be used. In these cases the output is converted in the presence of catalysts, which in case (A) accelerate the transformation and the polycondensation and in the m case (B) and the folic acid deansation. Some of the more important aromatic dicarboxylic acids are as follows: wherein R8 is an alkylene chain with 1 to 3 Koh @@@@ toffatomen or a remainder of the composition means. The preferred acids of this type are terephthalic acid, isophthalic acid, dibenzoic acid, naphthalene-1,5-diacid acid, naphthalene-2,6-diacid and haphthalene-2,7-diacid. The preferred polymethylene glycol is ethylene glycol, but you can also use one or more (at least one) of the following glycols: Ethylonglykol, Liäthyl ';; \ ig.ykol, Propylenglgkol, Butyleneglykol, decamethylene glycol, @oopentlyglykol and Trans-bis-1, 4- (hydroxymethyl) -cyclohesan, The organic phosphonate compounds suitable for the purposes of the invention are generally non-volatile under the conditions of temperature and pressure prevailing in the case of polycondensation, and / or contain reactive eStergroup to bind the phosphonsate to the To honor polyester. Furthermore, the phosphonate must not interfere with the polycondensation to a reasonable extent. Org @@@ ische Phoaphonatvorbindungen, which have proven to be effective in this sense, are (1) compounds of the formula in which at least one of the radicals R1, R2 or R3 is an alkyl, haloalkyl, hydroxyalkyl, aryl, aryloxy or alkenyl radical, while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, hydroxy-polyoxyalkylene, aryl , Aryloxy or alkenyl radicals. Typical examples of these compounds are di- (hydroxy-polyoxyethylene) -hydroxymethylphosphonate, di- (hydroxy-polyoxyethylene) -chloremthylphosphonate, di- (hydroxy-polyoxyethylene) -trichloromethylphosphonate, bis- (2-bromoethyl) -2-bromoethylphosphonate, chloroethyl) -2-chloroethyl phosphonate, bis-dipropylene glycol allyl phosphonate and diphenyl isodecane phosphonate.

(2) Compounds of the general formula in which R2 is a divalent organic radical and at least one radical of each of the groups R1, R2 or R4, R5 is an alkyl, haloalkyl-t hydroxyalkyl, aryl, alkenyl, haloalkenyl, hydroxyalkenyl or aryloxy radical, while the others Alkoxy, haloalkoxy, hydroxyalkoxy, aryl, AUMayl or aryloxy radicals are radicals. Typical examples of these compounds are bis [2-bromoethyl- (phenyl)] - ethylenediphosphonite and bis- (2-boron-3-chloroporopyl) -1 - [(2-bromo-3-chloroporpyl) -1-bromoethyl-2 chloroethylphosphonate] ethyl phosphoneate.

(3) 3) Compounds of the general formula in which R2 and R5 are divalent organic radicals and at least one radical from each of the groups (1) R1, R2, (20 R4 or (3) R6, R7 is an alkyl, haloalkyl, hydroxyalkyl, aryl, aryloxy or alkenyl radical while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, aryl, aryloxy or alkenyl creates.A typical example of such a compound is bis (2-chloroethyl) -1 - [(2-chloroethyl) -1 - [(2-chloroethyl) -2-chloroethylphosphonate] ethyl phosphonate] ethyl phosphonate.

(4) The duroh implementation of an alkyl phosphite of the general formula in which R1, R2 and R3 denote alkyl create with 1 to 5 carbon atoms, and a compound of the general formula in which X is a halogen atom or a hydrogen atom, products obtained.

Typical examples of such products are reaction products from triethyl phosphite and 2-chloroethanol and from triethyl phosphite and 2-bromoethanol.

(5) The reaction of an alkyl phosphonate of the general formula in which the reagents R1, R2, R3 are alkyl radicals, with a polymethylene glycol containing 2 to 10 carbon atoms in the molecule, an example of a product of this type is the conversion product of dimethylphosphonate with ethylene glycol.

(6) Compounds of the general formula in which R denotes an alkyl or alkenyl radical. A typical example of this is neopentylene allyl phosphonate (2-allyl-2-oxo-5,5-dimethyl-1,3,2-dioxaphosphorinane).

(7) Compounds of the general formula in which R 1 and R 2 are alkyl or alkenyl creations. A typical example of this is pentaorythritol diallyl diphosphonate (3, 9-diallyl-3, 9-dioxo-2, 4,8,10-tetraoxo-3,9-diphospha-spiro-5,5-undecane).

Ale organic phosphonate di- (hydroxy-polyoxyethylene) -hydroxymethylphosphonate is preferably used, Di- (hydroxy-polyoxyethylene) -chloromethylphosphonate, di- (hydroxy-olyoxy- #thylene) -triahlomethylphosphonate, Bis- [2-bromoethyl- (pghenyl)] -ethylene diphosphonate, (2-bromoethyl) -2-bromoethylphosphonate, Bis- (2-chloroethyl) -2-chloroethanol, $ triethyl phosphite from triethyl phosphite and 2-chloroethanol, the conversion product of triethyl phosphite and 2-bromo-ethanol or the conversion product from dimethyl methylphosphonate and ethylene glycol.

The organic phosphonates can be added to the reaction mixture at any time be added before or during the polycondensation and should be in the reaction mixture in an amount not less than 0.05 percent by weight, based on the amount of weight the alkyl ester of the arowatisohen dicarboxylic acid (e.g. of the terephthalic acid dimethyl ether), used in the initial umeature reaction contain aein.

Typical catalyst mixtures for the transesterification between the alkyl ether the aromatic dicarboxylic acid with 1 to 7 carbon atoms in the alkyl group, preferably dimethyl terephthalate, and the polymethylene glycol with 2 to 10 carbon atoms in the molecule, preferably ethylene glycol, and for the subsequent polycondensation to the polyester, preferably polyethylene terephthalate, which with the invention - Which organic phosphonate additives are compatible are in the following Given in the table.

T a b e 1 1 @ I Percentage composition range, based on the amount by weight of catalyst dimethyl terephthalate zinc acetate dihydrate 0.01-0.05 Lithium hydride 0.003 - 0.015 Antimony trioxide 0.02 - 0.04 Manganese II) acetate 0.0001 - 0.003 antimony trioxide 0.00005 - 0.003 zinc acotate dihydrate 0.01 - 0.05 antimony trioxide 0.02 - 0.04 zinc acetate dihydrate 0.01-0.10 tetraisopropyl titanate 0.0015 - 0.0045 Zinc acetate dihydrate 0.02-0.05 tetraisopropyl titanate 0.0015-0.0045 zinc acetate dihydrate 0.02 - 0.05 lithium hydride 0.003 - 0.015 lanthanum titanate 0.01 - 0.10 lanthanum oxide 0.01 - 0.10 lanthanum titanate 0.01 - 0.10 cerium oxide d 0.001 - 0.05 lithium hydride 0.003 - 0.015 zinc acetate dihydrate 0.01 - 0.05 cobalt (II) acetate 0.01 - 0.05 T a b e 1 l e I (continued 0 percentage composition range, based on the Amount by weight of catalyst dimethyl terephthalate lithium hydride 0.003-0.015 cadmium acetate 0.01 - 0.15 Cobalt (II) acetate 0.01 - 0.15 Cobalt (II) acetate 0, 01-0, 15 Antimony trio 0.01-0.10 Zinc Acetate Dihydrate 0.02-0.05 Antimony Trioxide 0.02-0.05 Hagneeiuma Acetate Dihydrate0003-0.01 Smooth lead (PbO) 0.005 - 0.1 Antimony trioxide 0.01 - 0.15 Cobalt (II) acetate 0.01 - 0.15 black lead 0.01 - 0.10 cobalt (II) acetate 0.01 - 0.15 black lead 0.01 - 0.10 antimony trioxide 0.01 - 0.10 calcium acetate 0.01 - 0.15 antimony trioxide 0.01 - 0.10 Lead plate 0.005-1.0 Manganese (II) formate 0.1 - 0.10 Silicatungstic acid 0.01 - 0.10 Typical catalysts for polycondensation which are compatible with the phosphonates the bis-hydroxyalkyl ester of aromatic dicarboxylic acid, preferably bis-2-hydroxyethyl terephthalate, are given in the following table.

T a b e l 3 eII Percentage composition range based on the weight of the catalyst dimethyl terephthalate germanium oxide 0.001 - 0.05 antimony trioxide 0.02-0.04 Tetraisopropyltant 0.0015-0.0045 Zinc acetate dihydrate 0.02-0.05 Lithium hydride 0.003 - 0.015 antimony trioxide 0.02 - 0.04 lithium hydride 0.001 - 0.0010 According to a preventive embodiment of the invention, a polyethylene tereph thalat foil continuous in a series of consecutive continuous Process stages produced as follows: The terephthalic acid dimethyl ester is with ethylene glycol under transesterification conditions in the presence of a transesterification catalyst to bis-2-hydroxyethyl terephthalate with an intrinsic viscosity of no more implemented as 0.2.

The bis-2-hydroxyäthylterphtalat is under a pressure of 0 to 25 mm Hg in the presence of a Polykondenaationakatalyaators and one of the above mentioned organic phosphonato in an amount of at least 0.05 percent by weight on the dimethyl terephthalate, heated to about 230 to 290 ° C until a film forms Polyethylene terephthalate (Intrinsic Viscolite at least 0.45) has formed. Of the Molten polyester is extruded into a self-supporting film, the film is stretched at least 2.5 times in at least one direction, and the Stretched film is oriented and heat set by heating to 150 to 250 ° C. but you can also direct the polycondensation of bis-2-n-hydroxyethyl terephthalate perform by taking from a previously synthetically produced bis-2-hydroxyethyl terephthalate proceeds as a chemical intermediate in flake form.

B e i a p i # 1 e1bis4 samples of polyethylene terephthalate foils as follows: Ethylene glycol and dimethyl terephthalate are in the Ratio of 1 mole of dimethyl terephthalate to 2 moles of ethylene glycol together with 0.002 Weight percent lithium hydride ,. 0.012 weight percent zinc acetate dihydrate and 0.03 Weight percent antimony trioxide (based on dimethyl terephthalate) in one with one R-equipped reaction vessel inserted. The transesterification is carried out at atmospheric pressure and 140 to 220 ° C with constant stripping of methanol from the reaction vessel carried out. After the transesterification, the polycondensation of the bis-2-hydroxyethyl terephthaltats at 230 to 290 ° C and a pressure of 0.05 to 2.5 mm Hg. During the polycondensation, glycol is continuously expelled from the reaction vessel. After the conversion is complete, a solution of the organic phosphonate in ethylene glycol is used (3 parts by weight of phosphorus-containing additive) is injected into the reaction vessel.

The plycondensation is carried out until the desired intrinsic viscosity is reached, d. H. in the range of 0.45 to 0.65. The polyester is put into an extruder entered the molten polyester continuously into an amorphous film squeezes out. The pile is cooled to room temperature on an Abachreok roller.

The following organixes are used as additives in the polycondensation Phosphonate compounds used: (1) bis [2-bromoethyl (phenyl)] - ethylenediphosphonate, (2) bis (hydroxy-polyoxyethylene) -hydroxymethylphosphonate, (3) the conversion product of triethyl phosphite and 2-chloroethanol, (4) the reaction product of triethyl phosphite and 2-bromoethanol and (5) bis (2-chloroethyl) -1 - [(2-chloroethyl) -1 - [(2-chloroethyl) -2-chloroethylphosphonate] ethyl phosphonate] ethyl phosphonate.

The phosphonate compounds (3) and (4) are produced as follows : Implementation between triothyl phosphite and 2-chloroethanol: triethyl phosphite and 2-chloroethanol are heated in a ratio of 1: 1 in a reaction vessel, until the mixture has reached a temperature of 200 ° C. Here the distill Reaction by-products (ethanol and low-boiling substances).

To complete the implementation, the Reationsrücksand is up to distilled to a temperature of 250 ° C and a pressure of 15 mm Hg in vacuo. The pre-combustion analysis of a sample of this reactor shelf provides the following Results: Phosphorus = 22.98% carbon = 31.14% hydrogen = 6.42% chlorine = 4.27% oxygen = 15.19%.

The material cannot be distilled. The following structural formula results from this analysis: Conversion product of triethyl phosphite and 2-bromoethanol: triethyl phosphite and 2-bromoethanol are heated in a molar ratio of 1: 1 in a reaction vessel until the reaction mixture has reached a temperature of 200.degree. The reaction by-products (unidentified low-boiling substances in ethanol) are distilled off. To complete the reaction, the reaction residue is subjected to vacuum distillation up to 250 ° C and 15 mm Hg. The material cannot be distilled. The analysis gives the following structural formula: Samples of the polyethylene terephthalate films produced by the above process as well as control samples of polyethylene terephthalate films which are produced in the same way, but with the replacement of the organic phosphorus compound by an inorganic phosphorus compound, namely monoammonium phosphate, are expressed in terms of their film capacitor insulation resistance, expressed as mean specific resistance in ohms -on x 1012 (according to the Binfoliqntest), and examined for their color, expressed as the percentage yellow content of a 0.127 mm thick sample =.

The insulation resistance is determined according to the dielectric single-film method certainly. On the electrical application area, the insulating material or dielectric is used generally subjected to electrical sprays, which cause a flow of currents lead in the dielectric. When the resistivity at higheron temperatures decreases, the current flow increases. In the case of capacitors, this is particularly important Sfromfluse ss generates higher temperatures and therefore shortens the lifespan. Of the specific resistance of a dielectric made of polyethylene terephthalate film measured by making a capacitor using a foil as a dielectric builds and the capacitor in a bridge circuit with high resistance (General Radio Megohm Bridge - Type 544-B) switches on.

In the case of the dielectric single-foil element, a single foil is used to be examined dielectric used, and from the measured resistance in Ohm is the volume resistivity (between opposing surfaces of the unit cube) is calculated in Ohm'cl. The single-film measurement is carried out by placing a round electrode (diameter 25.4 mm) on each side with the sample from bekann the thickness is painted. The phobe will. between brass plates of the electrode cell used, which is connected to t the megohn bridge. From the one measured at 125 ° C Resistance in ohms becomes the specific resistance (r) in ohms cm according to the following Equation calculated: 4 = R x Q / t, where r the resistance in ohms at 125 ° C, A is the area in cm2 and t is the thickness in cm. indicates.

The color measurement on the film samples is carried out in a device of the type "Oolor Master "and converted to a thickness of 0.127 mm.

In the examples of Table III, the phosphorus additives, their amounts in percent by weight, based on dimethyl terephthalate, is the mean specific resistance in ohms. cm x 10 and the percentage of yellow content based on a 0.127 mm dioke polie, specified.

T a b e l e III Influence of organic phosphonate compounds on the electrical cons and the color of polyethylene terephthalate foils mean speci-wt .-% Addition, fischer cons% Gelbge-Bei- related to stand, halt / Mitt game addition DTM (1) Ohm # cm x 1012 0.127 mm d 1 B2BMPPE * 0.11 6.08 2.20 2 B2BMPPE * 0.17 9.25 1.83 3 B2BMPPE * 0.23 11.47 1.87 4 POEHMP ** 0.17 20.30 2.12 5 POEHMP ** 0.23 21.40 1.87 6 PP-BR *** 0.11 10.50 1.68 7 PP-BR *** 0.17 15.50 1.55 8 PP-BR *** 0.23 17.60 1.21 9 PP-CL **** 0.06 11.10 1.99 10 PP-CL **** 0.11 19.70 0.94 11 PP-CL **** 0.17 25.80 0.82 12 PP-CL **** 0.23 35.10 1.22 13 B2CEP ***** 0.23 34.47 1.00 Kon- Monoammonium- 0.08 7.70 3.39 trolle phosphate "Monoammonium- 0.11 7.40-phosphate" none - 1.40 3.95 "none - 2.90 2.59" none - 3.30 4.81 "none - 3.70 5.16 - notes for table III see page 18 - Notes to Table III * B2BMPPE = Bis [2-bromoethyl - (@@@@@@ l)] - ethyl sndiphosphonate ** POEHMP = bis (hydroxy-soly @@@@ ethylene) -hydroxymethylphosphonate *** PP-BR = conversion product from triethylphosphite and 2-bremäthemol **** PP-CL = Reaction product of triethyl phosphite and 2-chloroethanol ***** B2CEP = bis (2-chloroethyl) -1 - [(2-chloroethyl) -1 - [(2-chloroethyl) -2-chloroethylphosphonate] ethyl phosphonate] ethyl phosphonate (1) DMT = Dim ethyl terephthalate Examples of 15 to 16 samples from practically amorphous polyethylene terephthalate film are hydrated according to Example 1 to 14, The catalyst consists of 0.006 parts by weight of lithium hydride, 0.012 parts by weight Zinc acetate dihydrate and 0.03 percent by weight of antimony trioxide, based on dimothyl tereplwhalat. Before the poly @ ondensation, the reaction mixture becomes an organic one Phosphonate in an amount of 0.23 percent by weight, based on diethyl terephthalate, added. PP-cl (the reaction product of triethyl phosphite and 2-chloroethanol) and hydroxy-polyoxyethylene hydroxymethylphosphonate. After this The foils are continuously extruded and quenched in the longitudinal and transverse directions each stretched 3 times to provide a balanced film, i.e. H. such to obtain their physical properties in both directions practically dio are the same. Then the foils, wGhrenel sio are kept under tension, Heat-fixable at 200 ° C. The mean capacitor insulation resistance is representative of the film samples and the percentage of yellow, based on a 0.127 mm thick film, determined. The mean capacitor insulation resistance is determined by taking a wound Capacitor assembled and the dielectric rated in kegohms x microfarads will. The wound capacitor consists of alternating individual layers of polyethylene terephthalate film (Broad 50.8 mm) and Aluinium (width 38.1 mm). The length of the wound on the capacitor Foil depends on the desired capacity. The resistance of the coiled Capacitor is determined at 125 ° C with a Hegohia bridge, and then is under the same conditions the capacity with the help of a capacity analyzer of the Cornell-Dubilier type. The product from the two waiting areas gives the Magohmx microfarad value.

The prosentual yellow content for foils 0.127 mm thick is again Measured with the test device of the H type "Coloer Master".

In Table IV the additives, their amounts in percent by weight, the mean capacitor insulation resistance and the percentage of yellowness for 0.127 Specify mm thick foils. A polyethylene terephthalate film is used as a control sample, in the manner described above, but with replacement of the organic phosphonate by monoammonium phosphate.

T a b e l l e IV Influence of organic phosphonate compounds on the Electrical resistance and the color of polyethylene terephthalate films Average condensation% by weight Addition, sator-Isolation-% yellow-add-based on stand, resistance, meg- hold / With play addition DMT *** Ohm x Microfard 0.127 mm @ 15 PP-CL * 0.23 1239 1.59 16 FOEHMP ** 0.23 458 2.01 Kon- Monoammonium- 0.02 330 3.64 trolle phosphate * PP-CL = reaction product from triethyl phosphite and 2-chloroethanol ** POEHMP = bis (hydroxy-polyoxyethylene) -hydroxyme ethyl phosphonate *** DMT = dimethyl terephthalate Examples 17 to 28 samples of practical. Amorphous polyethylene terephthalate is used to make the reaction mixture an organ in a chronophone Eatalyst manufactured. Before the polycondensation is to the reaction mixture an organic phosphonate compound in amounts of 0.08 to 0.34 percent by weight, based on dimethyl terephthalate, added. Hydroxypolyoxyethylene chloromethylphosphonate serve as additional Hydroxy-polyoxyäthylentr3clalora TT w hophowt un. 3. (2- '. Roiaa';: -; 1) m. rG: it:; ; : 1. a phonate. After extrusion and quenching, that will be Films in the machine direction 9 longitudinal direction) stretched 3 times. then the foliage, while keeping them under tension, is heat-set at 200 ° C. The mean specific resistance in ohms x em is, as described obsn, according to determined by the dielectric single-film method, and the prosentual yellow content, based to a film thickness of 0.127 mm is measured. Table V shows the additions Their amounts in percent by weight, the mean Pacific resistance (Ohhm # cm x 1012) and the percentage yellow content given for 0.127 NH Foliondicka. As a control sample dint a polyethylene terephthalate film, which is made in the same way, but under Use of monoammonium phosphate instead of the organic phosphonate is.

T a b e l l e V Influence of organic phosphonate compounds on the electrical contradiction and the color of polyethylene terephthalate foils mean speci-weight% Addition, fischer Wider-% Gelbge-Bei- related to stand, hal t / Mieel game addition DMT *** ohm # cm x 1012 0.127 mm di 17 POECMP * 0.08 56.2 2.78 @ 18 POECMP * 0.17 54.9 2.40 @ 19 POECMP * 0.26 30.0 1.67 @ 20 POECMP * 0.34 68.1 1.40 @ 21 POETCMP ** 0.08 60.1 2.28 @ 22 POETCMP ** 0.17 54.4 2.07 @ 23 POETCMP ** 0.26 62.6 1.34 @ 24 POETCMP ** 0.34 65.8 1.07 @ 25 bis (2-bromoethyl) - 0.08 41.5 2.25 @ 2-bromoethylphosphonate 26 "" "0.17 49.8 1.90 @ 27" "" 0.26 52.1 1.86 @ 28 "" "0.34 60.3 2.21 @ Kon- Monoammonium 0.09 63.8 - @ trolle phosphate * POECMP = hydroxy-polyoxyethylene chloromethyl phosphonate ** POETCMP = Hydroxy-polyoxyôthylene-trichloromethylphosphonate *** DMT = Dimethyltere phthalate Ex. 29 to 33 samples of practically anorphic ones Polyôthyleneterephthalstfolie are, as described above, with the same catalyst manufactured. With the catalysts, Dimethyl-methylphosphonet is used in amounts between 0.14 and 0.53% by weight based on the: @ dimethyl terephthalate, either during the transesterification between the dimethyl terephthalate and the ethylene glycol or directly before the polycondensation of the conomers after the reaction with the ethylene glycol in the presence of a catalyst (a.B.

Lithium hydride) added. In both cases, the dimethyl phosphonate goes into a glycol phosphonate derivative. After the polycondensation, the polyester, As described above, extruded and cut off from a film 0.127 mm thick.

Representative samples of the film are taken as described after the Binfolion method investigated for its capacitor insulation resistance. In table VI are the additives, the way in which the addition is made, the amount in percent by weight and the mean specific resistance indicated.

T a b e l l e VI Dim flow of mixed phosphonet compounds on the oloctrischen specific @ of polyethylene tereptthalate foils average weight% additive, Specific additions to Widersted game Addition Sugestzt to DMT * Oh. # cm x 1011 29 Dimthyl- In the production 0.14 11.77 metylwhes- of the monomers added 30 "" Esterified with ethylene glycol by 0.58 15.18 and numbered before the polycondensation added 31 "" "" "" 0.58 14.00 32 '"In preparation 0.14 12.35 of the monomer added 33 "" "" "" "0.14 11.40 con- none - - - 4.97 trolle- monoammonium- Added to the monomer 0.09 10.96 trelle phosphate * DMT = dimethylterophthalate B. e i e p i e 1 # 34 to 36 samples of practically amorphous polyethylene terephthalate portfolio are prepared as described above. The catalyst consists of 0.06 percent by weight Lithium hydride, 0.012 percent by weight zinc acetate dihydrate and 0.03 percent by weight Antimony trioxide, based on dimethyl terephthalate. Before the polycondensation is su the monomer reaction mixture, an organic phosphonate compound in abundance of 0.23 weight percent added. Hydroxy-polylxyäthylen-hydroxymethylphosphonat serve as additives and the reaction product of triethyl phosphite and 2-chloroethanol. After extrusion and the film samples are scraped off in the longitudinal and transverse directions in each case on the 3 times stretched. The films are then heat-set at 200 ° C. under tension. Representative samples of the films are described in Examples 15 and 16 Way examined for their insulation resistance. The color is determined in this case according to the trifluoroacetic acid method. The determination is as follows carried out: 2 to 2, 5 g of polyester are distilled in a Spofford flask with Trifluoroacetic acid added. 10 ml of trifluoroacetic acid are used per gram of polyester added. The flask is shaken in a soft-shaking machine at room temperature, until the polyester is completely in solution (about an hour). The color analysis takes place with a Beckmann spectrophotometer (E-U). For the determinations 10 ml cells made from refractory glass are used. The cell is first coated with trifluoroacetic acid washed. The absorption capacity of the polyester solution is reduced in the case of a wave liner of 400 mµ and compared with a comparison cell containing t trifluoroacetic acid is filled. The color is expressed in terms of absorbency. In Table YII for each example is the film thickness in the stretched state, the additive, the amount of the additive in percent by weight, the insulation resistance in megohms x microfarads and the color (trifluoroacetic acid) indicated, T a b e l l e VII Influence of mixed phosphonet compounds on the electrical contradiction and the color of polyethylene terephthalate films insulation weight% additive, resistance, At- (stretched), zongen suf Megohm x F @ game mm Addition DMT * Microfarad (Trifluo @ 34 0.0127 POEHMP * 0.23 557 0.35 0.0127 PP-CL ** 0.25 590 0.36 0.0254 POEHMP * 0.23 - 0, Kon 0.0127 Monoammohium- 0.09 429 0, trolle phosphate * POEHMP = bis (hydroxy-polyoxyethylene) -hydroxymethylphsophonat ** PP-CL = reaction product of triethyl phosphite and 2-chloroethanol *** DMT = dimethyl terephthalate . I samples of practically amorphous polyethylene terephthalate film were produced by direct polycondensation of bis (ß-hydroxyethyl) -terephthalate produced by the following process: Bis (ß-hydroxyethyl) terephthalate, which is produced in a known manner, is melted in the form of flakes in a resection at 14.0 ° C. As a catalyst dicnt tetraisopropyl titauate in a concentration of 1 to 2 parts titanium per million Parts by weight of the participants in the action. This catalyst immediately becomes the Bis- (0-hydroxyethyl) -torephthalate added to the reaction vessel. Likewise 0.146 percent by weight of hydroxypolyoxyethylene hydroxymethylphosphonate are immediately added to the reactants added. The amount by weight of the organic phosphonate refers to the amount by weight used in the manufacture of bis (ß-hydroxyethyl) tereplithalate as the starting material used dimethyl terephthalate. The reaction mixture is heated to 140 ° C, to melt the monomer and the catalyst.

Excess Ethylcnglykol by heating the reaction mixture distilled off to 230 ° C in the course of 40 minutes.

The polycondensation of the bis (ß-hydroxyethyl) terephthalate then takes place to polyethylene terdephthalate by heating the mixture, while the reaction is carried out two hours in the steam of boiling dimethyl terephthalate under one pressure the contents of the vessel is heated from 0.5 to 0.1 mm Ig to 282o C. The melted one Polyester is extruded on a film and a giant on a 70 to 80 ° C held quenching roller quenched. Samples of the extruded and quenched Foil are each 3 times g in the longitudinal and transverse directions and under tension Heat set at 200 ° C. The films are tested for their condenser insulation resistance using the single-film method and examined for color by the trifluoroacetic acid method. For the production the control foils is bis (ß-hydroxyethyl) terephthalate in the same way, However once. under traatz of the organic phosphonate compound polycondensed by monoammonium phosphate and another Maol without phosphorus-containing additive. When using Monoammonimaphoapha.t, antimony trioxide serves as a catalyst A quantity of 0.03 percent by weight, based on dimethyl terephthalate, in table VIII are the thicknesses of the extruded and the "stretched foils, the catalysts, the phosphorus compounds, the mean specific resistance in ohms # cm x 1012 and the color measured by the trifluoressogsauromethod is given.

T a b e l l e VIII Influence of organic phosphonet compounds the electrical resistance and the color of polyethylene terephthalate films are medium Wt .-% s @ z.Widerdicke additive, stood the (strand-thickness related stretched-pressed), stretched), on foil play mm mm catalyst additive DMT * Ohm # cm x 1012 37 0.3048 0.0343 tetraisorpro- hydroxy- 0.146 81 pyltitanate polyoxyethylene hydroxymethylphosphonate 38 0.3048 0.0322 "" "" 0.146 97 39 0.3175 0.0368 "" "" 0.146 80 Kon 0.2540 0.0330 Sb2O3 mono- 0.09 76 trolle ammonium phosphate * DMT = dimethyl terephthalate As sicli results from the above values, offers the addition of the organic phosphonate compound in the polycondensation of bis (k-hydroxyethyl) terephthalate to polyethylene terephthalate within the meaning of the invention, the following advantages: 1. Less inhibiting effect the polycondensation of the monomer. As the organic phosphonates normally do The catalyst used for polycondensation is not in a reasonable amount deactivate, lcömon now economically valuable polycondensation rates achieved and all available for polycondensation to polyethylene terephthalate standing Katalyeatoron can be used without the risk of significant deactivation.

2. Significant pussiness of the color of the polyester. One main cause The yellow color of the was used for the objections of the foils by the consumer Films (the mlndeatens partly due to the phosphorus-containing additives was). Through the use according to the invention of organic phosphonate compounds In the case of polycondensation, see poly (ethylene terephthalate) the yellow color of the finished product Foil is significantly weakened, which is a significant economic ae.

3. Higher film capacitor insulation resistance. Duroh this improvement the insulation resistance achieve condensers in which polyethylene terephthalate All dielectrics are used to ensure a longer lifespan without breaking down at high temperatures.

4. Less precipitation due to reaction with other catalysts and Additions. Since there is no reaction with other catalysts, less is possible Time lost for business interruptions that were previously necessary to deal with failed Clean clogged filters and supply nozzles for reaction products.

Ex. 40 monomeric naphthalene-2,6-dicarboxylic acid ethylene glycol ester is made by unesterification of ethylene glycol with naphthalene-2,6-dicarboxylic acid dimethyl ester using manganese (II) acetate (Mn (OAc) 2.4 H20) and antimony trioxide (Sb2O3) made in the well-known white.

Three separate polyesters are made from this monomer. All contain the same catalyst, but the urate (Example 40) contains one organic phosphonate, the second an inorganic phosphate (monoamonium phosphate) and the third no addition at all. The reaction mixtures are as follows : Example 40 600 g of naphthalene-2,6-dicarboxylic acid ethylene glycol ester, 0.88 g of polyoxyethylene hydroxymethylphosphonate 0.07 g zinc acetate dihydrate 0.028 g antimony trioxide 0.019 g lithium hydride control sample A 600 g of naphthalene-2,6-dicarboxylic acid ethylene glycol ester and 0.83 g of monomammonium phosphate 0.07 g zinc acetate dihydrate 0.028 g antimony trioxide 0.019 g lithium hydride control sample B 600 g of naphthalene-2,6-dicarboxylic acid ethylene glycol ester 0.07 g of zinc acetate dihydrate 0.028 g antimony trioxide 0.019 g lithium hydride The polycondensation reactions are carried out at 285 to 290 ° C and a pressure in the range from 0.05 to 2.5 mm Hg, until. the desired intrinsic viscosity has been achieved. The one with the (polymeric) phosphonate produced polyester shows a weaker color than after the polycondensation the other two, polyester. The polyesters are then extruded into films and deterred. This is where the slides are. by stretching in Longitudinal and transverse direction each molecularly oriented 4 times and then Heat set at 220 to 240 ° C.

The resistance to hydrolysis of those produced from the three polyeater approaches Slides are examined as follows: A series of small, water-filled Glass beakers are geeetst on the bottom of 3.785 1-capacity rectangular canisters, from which the lids are removed. Samples of the films are made from the three polyesters hung in the kainster above the water-filled Beoher glasses. The canister is covered with aluminum foil and placed in an 80 ° C oven. from From time to time, samples of the foils are taken out and by hand by quick bending back and forth examined for brittleness. After bending, the film samples are checked for signs checked for crack formation. These studies on the resistance to hydrolysis show d from the prepared according to Example 40 (containing the organic phosphonate) Films still after 345 days in an atmosphere of 100% relative humidity and remained pliable at 80 ° C. Control sample A (which contains the inorganic phosphate contains) fails after just 75 days, while those do not contain any phosphorus-containing additive containing control sample B failed after 110 days. When samples of the oriented Films made of the three polyesters hinduroh in an oven at one temperature for a longer period of time are exposed to 200 ° C, say the control films B due to oxidative degradation after 137 hours, the control films A after 145 hours and the e according to the invention produced films after 300 hours.

The films produced according to the invention thus show an improvement by more than double.

Similar improvements in the hydrolysis resistance are seen in foils from polyethylene terephthalate observed with the help of the organic phosphonate catalyst are made.

] LA..J; .. l..il.-In a manner known per se, two separate Umeaterungareaktionen between Äthylenglkol and a mixture of Bibenzoogäurodimethylester and 4,4'-isropylidenedibenzoic acid dimethyl ester. In one case it will when converting as organic phosphonate polyoxyethylene hydroxymethylphosphonate, otherwise no phosphonate was added. The implementations are with the following Approach carried out: Example 41 432 g of dimethyl bibenzoate 124 g of 4,4'-isopropylidene dimethyl bibenzoate 273 g ethylene glycol 0.1962 g Mn (OAc) 2 # 4 H2O 0.1164 g Sb2O3 0.17 g polyoxyethylene hydroxide ethyl phosphonate (added in 1.5 ml ethylene glycol) control sample 432 g (1.6 mol) Dimethyl bibenzoate 124 g (0.4 mol) of 4,4'-isopropylidene dimethyl bibenzoate ter 273 g (4.4 mol) ethylene glycol 0.1962 g Mn (OAc) 2 # 4 H2O 0.1164 g Sb2O3 When the transesterification has ended, the two ITonomers are in a manner known per se Subjected to polycondensation. The one obtained from the (phosphonate-free) control sample Polyester is strongly colored, while that produced according to Example 41 (with the phosphonate) Polyester is very weak in color.

Claims (3)

Claims 1. A process for the production of linear polyesters duroh transesterification of alkyl esters of aromatic dioarboxylic acids, the alkyl groups of which each contain 1 to 7 carbon atoms, with polymethylene glycols with 2 to 10 carbon atoms in the presence of a transesterification catalyst and subsequent polycondensation of the bia-glycoleate in the presence of an organic phosphorus compound as a polycondensation catalyst, characterized in that the polycondensation is carried out in the presence of at least 0.05 percent by weight, based on the amount of the alkyl ester used for transesterification, on one of the following organic phosphonates: (a) Compounds of the general formula in which one of the radicals R1, R2 or R3 is an alkyl, haloalkyl, hydroxyalkyl, aryl, aryloxy or alkenyl radical, while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, hydroxypolyalkylene, aryl, alkenyl - or arylox radicals; (b) N compounds of the general formula ind he R3 is a divalent organic radical and at least one radical of each group of radicals R1, R2 or R4, R5 is an alkyl, haloalkyl, hydroxyalkyl, aryl, alkenyl, haloalkenyl, hydroxyalkenyl or aryloxy radical, while the other radicals are alkoxy, haloalkoxy, rydroxyalkoxy, ryloxy, aryl, alkenyl, haloalkenyl-o:?. er are hydroxyalkenyl radicals; (c) Compounds of the general formula in which R3 and R5 are divalent organic radicals and at least one radical of each of the groups (1) R1, R2, (2) R4 or (3) R6, R7 is an alkyl, haloalkyl, hydroxyalkyl, aryl, aryloxy or Alkenyl radical, while the remaining radicals are alkoxy, haloalkoxy, hydroxyalkoxy, aryl, aryloxy or alkenyl radicals; (d) dia by reacting an alkyl phosphite of the general formula in which R1, R2 and R3 denote alkyl radicals with 1 to 5 carbon atoms, with a compound of the general formula in which X is a halogen atom or a hydrogen atom, products obtained; (E) the reaction of an alkyl phosphoate of the general. a formula in which the radicals R1, R2 and R3 are alkyl radicals, products obtained with a polymethylene glycol having 2 to 10 carbon atoms in the molecule. 2. The method according to claim 1, applied to the manufacture of linear Polyesters of terephthalic acid. 3. The method according to claim 1 or 2, characterized in that the organic phosphonate in amounts of at least 0.07 percent by weight is applied to the amount of alkyl ether used for transesterification.