DE10330774A1 - Flame retardant modified, phosphorus-containing copolyesters, their use and processes for their preparation - Google Patents

Abstract

The invention relates to flame-retardant, phosphorus-containing copolyesters having a total phosphorus content of 5 to 7 wt .-%, which are obtainable by esterification of at least one dicarboxylic acid with at least one diol and / or by transesterification of at least one dicarboxylic acid diester with at least one diol in the presence of a flame-retardant bifunctional DOP Addition compound and at least one other bifunctional phosphorus-containing compound other than the bifunctional DOP addition compound, and polycondensation of the products formed or formed by esterification and / or transesterification, wherein the DOP addition compound provides at most 3.5% total phosphorus content while the remainder of the total phosphorus content is derived from the at least one other bifunctional phosphorus-containing compound. DOLLAR A process for the preparation of the flame-retardant modified, phosphorus-containing copolyesters and use of the copolyester as a masterbatch, preferably for the production of polyester fibers having a total phosphorus content of 0.4 to 0.7 wt .-%.

Description

The Invention relates to flame-retardant modified, phosphorus-containing copolyesters, their use as masterbatch, especially in the production of polyester fibers, and process for their preparation.

Originally Polymers of all kinds, including Synthetic fibers, flame-retardant in that inorganic or organic Flame retardants, e.g. Antimony trioxide or polybrominated diphenyl ether, blended into the polymer or those made from the polymer Superficial with it treated. Because of these flame retardants in case of fire form highly toxic gases and moreover the adhesion of the flame retardants on the polymeric surfaces with Increasing life of the appropriately equipped products subsides, went you over to it, to develop copolymerizable flame retardants which during the Polymerization in the polymer backbone added and thus more inherent Be part of the polymer.

So is known for example from DE-A-26 46 218, addition compounds of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (commonly called "DOP") and unsaturated Dicarboxylic acids like maleic acid, fumaric acid and in particular itaconic acid or dialkyl esters or anhydrides of these dicarboxylic acids as co-condensable, phosphorus-containing flame retardants in the polymer chain, especially for polyester, to use. The cited document also suggests a flame-retardant bifunctional DOP addition compound in such amounts to condense in the base polymer, that the phosphorus content in the case of polyesters in general to 0.05 to 5 wt .-% (500 to 50 000 ppm), while the phosphorus content in polyesters for the production of polyester fibers preferably 0.1 to 1 wt .-% (1000 to 10,000 ppm) should be.

According to the mentioned German Offenlegungsschrift may be the preparation of the flame retardant Modified, phosphorus-containing copolyester either done so, that DOP and the unsaturated one Dicarboxylic acid, like e.g. itaconic, solved in a diol and the solution obtained is fed directly to the polyester polymerization process. However, the preparation can also after the masterbatch process so done that first pellets a polyester Grundcharge prepared with high phosphorus content and then this with conventional Polyester pellets containing no fused phosphorus compound, be mixed before the mixture of the deformation stage, in the For example, polyester fibers are formed, is supplied.

Further from US-A-5 530 088 the preparation is flame retardant modified, phosphorus-containing copolyester, in which one first a dicarboxylic acid, e.g. terephthalic acid, esterified with a diol or transesterified a dicarboxylic acid diester with a diol, each in the presence of a flame-retardant bifunctional DOP addition compound, for example from DOP and itaconic acid or itaconate or di (hydroxyethyl) esters, and in the esterification or transesterification resulting products using special catalyst / cocatalyst systems polycondensed.

The thus produced flame-retardant modified, phosphorus-containing copolyester of said US patent have a total phosphorus content of less than 5% by weight and intrinsic viscosities of between 0.32 (Example 7) and 0.68 (Example 2). The flame retardant modified copolyesters of this US patent are used as masterbatch used, i. they are then treated with ordinary Polyethylene terephthalate (PET) mixed, in such proportions, that the Total phosphorus content of the resulting mixtures between 0.3 and 0.7 wt .-%, and the copolyester is then the desired End product, such as polyester fibers, further processed.

The The most important industrial production process for polyester fibers is the melt spinning process. As the expert is well known, but require polyester, if they are to be spun by the melt spinning process, a Intrinsic viscosity [η] or "intrinsic viscosity" of at least 0.6, so usable threads or filaments can arise. These values do not, of course, refer to masterbatch polyester, but on the polyester melt to be spun.

Unfortunately, with the flame-retardant modified phosphorus-containing copolyester masterbatches known from the aforementioned prior art, polyester or copolyesters having melt spinning properties can not be produced on an industrial scale because either the total phosphorus content or the maximum achievable intrinsic viscosity or both values are too low to simultaneously produce the necessary To obtain melt spinning properties and the total phosphorus content in the final product necessary for fire protection reasons.

Of the The invention is therefore based on the object to remedy this disadvantage and a flame retardant modified phosphorus-containing copolyester with a total phosphorus content of 5 to 7% by weight and one for melt spinning sufficiently high degree of polymerization to be achieved in polyester such as. Incorporated polyethylene terephthalate and flame retardant equipped Fibers or filaments melt-spun or to films, moldings or hollow can be processed from flame-retardant modified copolyester.

• a) Veresterung mindestens einer Dicarbonsäure mit mindestens einem Diol und/oder durch Umesterung mindestens eines Dicarbonsäurediesters mit mindestens einem Diol in Gegenwart (1) einer flammhemmenden bifunktionellen DOP-Additionsverbindung der Formel I
  
  worin R ein Wasserstoffatom, eine C₁ - C₄-Alkylgruppe oder eine C₁ - C₄-Hydroxyalkylgruppe ist, und (2) mindestens einer weiteren, von (1) verschiedenen, bifunktionellen, phosphorhaltigen Verbindung und
• b) Polykondensation der bei der Veresterung und/oder Umesterung entstehenden oder entstandenen Produkte, wobei die DOP-Additionsverbindung höchstens einen Gesamtphosphorgehalt von 3,5 Gew.-% liefert, während der Rest des Gesamtphosphorgehalts von der mindestens einen weiteren bifunktionellen, phosphorhaltigen Verbindung stammt.

This object is achieved by a flame retardant modified, phosphorus-containing copolyester having a total phosphorus content of 5 to 7 wt .-%, which is obtainable by

• a) esterification of at least one dicarboxylic acid with at least one diol and / or by transesterification of at least one dicarboxylic acid diester with at least one diol in the presence of (1) a flame-retardant bifunctional DOP addition compound of the formula I.
  
  wherein R is a hydrogen atom, a C ₁ - C ₄ alkyl group or a C ₁ - C ₄ -hydroxyalkyl group, and (2) at least one other, different from (1) bifunctional, phosphorus-containing compound and
• b) polycondensation of the products formed or formed in the esterification and / or transesterification, wherein the DOP addition compound at most provides a total phosphorus content of 3.5 wt .-%, while the rest of the total phosphorus content of the at least one further bifunctional, phosphorus-containing compound.

• a) mindestens eine Dicarbonsäure mit mindestens einem Diol verestert und/oder mindestens ein Dicarbonsäurediester mit mindestens einem Diol umgeestert wird, und zwar in Gegenwart (1) einer flammhemmenden bifunktionellen DOP-Additionsverbindung der Formel I
  
  worin R ein Wasserstoffatom, eine C₁ – C₄-Alkylgruppe oder eine C₁ – C₄-Hydroxyalkylgruppe ist, und
• b) die bei der Veresterung und/oder Umesterung entstehenden oder entstandenen Produkte polykondensiert werden,

wobei die Veresterung und/oder Umesterung in Gegenwart (2) mindestens einer weiteren bifunktionellen phosphorhaltigen Verbindung durchgeführt wird, die von der DOP-Additionsverbindung verschieden ist, und die DOP-Additionsverbindung in einer Menge verwendet wird, die einem Gesamtphosphorgehalt des Copolymers von höchstens 3,5 Gew.-% entspricht, während der Rest des Gesamtphosphorgehalts von der mindestens einen weiteren bifunktionellen phosphorhaltigen Verbindung geliefert wird.The object is further achieved by a method for producing a flame retardant modified, phosphorus-containing copolyester having a total phosphorus content of 5-7 wt .-%, in which

• a) at least one dicarboxylic acid is esterified with at least one diol and / or at least one dicarboxylic acid diester is transesterified with at least one diol, in the presence of (1) a flame-retardant bifunctional DOP addition compound of the formula I.
  
  wherein R is a hydrogen atom, a C ₁ -C ₄ -alkyl group or a C ₁ -C ₄ -hydroxyalkyl group, and
• b) polycondensing the products formed or formed during the esterification and / or transesterification,

wherein the esterification and / or transesterification is carried out in the presence of (2) at least one other bifunctional phosphorus-containing compound other than the DOP addition compound, and the DOP addition compound is used in an amount corresponding to a total phosphorus content of the copolymer of at most 3, 5% by weight while the remainder of the total phosphorus content is provided by the at least one further bifunctional phosphorus-containing compound.

In the invention, it has surprisingly been found that high, melt-spinnable degrees of polymerization are achieved up to a total phosphorus content of 7 wt .-%, if the flame-retardant bifunctional DOP addition compounds of the formula I only up to a maximum content of 3.5 wt .-% phosphorus are used and to the required total phosphorus content of 5 to 7 wt .-% still missing phosphorus content of at least one other bifunctional phosphorus-containing compound, which is different from the DOP addition compounds of the formula I and which is preferably selected from at least one compound of from 2-methyl-2,5-dioxo-1-oxa-2-phospholane of the formula II and 2-carboxyethyl (phenyl) -phosphinic acid of the formula III group:

The Intrinsic viscosity [η] the according to the invention, flame-retardant modified, phosphorus-containing copolyester is preferably at least 0.5, more preferably at least 0.6, each measured at 20 ° C in m-cresol as a solvent.

A Intrinsic viscosity of at least 0.5, but less than 0.6, is for the manufacture of Films, foils, moldings and hollow bodies sufficient. For the production of fibers and filaments by the melt spinning process however, is an intrinsic viscosity of at least 0.6 required. The desired increase in limiting viscosity number becomes through change the relative proportions of other bifunctional phosphorus-containing Compounds of formulas II and III are accomplished, including one of ordinary skill in the art be able to do so easily due to his general expertise is (see, for example, Franz Fourné, "Synthetic fibers", Carl Hanser Verlag, Munich 1995).

When dicarboxylic acid for the preparation of the copolyesters of the invention is preferably at least one of the acids terephthalic acid, isophthalic and 2,6-naphthalenedicarboxylic acid used, wherein the proportion of the different from terephthalic acid dicarboxylic acid (s) preferably at the most 5 mol .-% of the total amount of dicarboxylic acids.

If the polyester backbone not by esterification of a dicarboxylic acid with a diol, but by Transesterification of a dicarboxylic acid diester is to be prepared, then is at least one diester as Dicarbonsäurediester at least one of the aforementioned acids terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid with used at least one aliphatic alcohol having 1 to 4 carbon atoms.

When Diol will preferably be ethylene glycol and / or 1,4-cyclohexanedimethanol uses. In addition, you can theoretically also others, for the production of linear polyesters known and proven diols be used; for cost reasons however, ethylene glycol and 1,4-cyclohexanedimethanol are preferred.

Especially The copolyesters of the invention are preferably in the form of a Masterbatch granules or produced in the form of a masterbatch melt, to make them especially easy with ordinary polyester granules or an ordinary one Polyester melt as possible mix homogeneously and a polyester production plant, preferably a melt spinning plant, perform to be able to.

One Another object of the invention is thus the use of the above described, flame-retardant modified, phosphorus-containing copolyester as a masterbatch for the production of flame-resistant polyesters with a Gesmtphosphorgehalt of 0.4 to 0.7 wt .-%, preferably, as their use for the production of polyester fibers, polyester filaments or polyester monofilaments, more preferably their use for Production of fibers, filaments and monofilaments by the melt spinning process or their use for the production of polyester moldings or Polyester hollow bodies.

For the preparation of the phosphorus-containing masterbatch polymers, all technologies known to those skilled in the art for the production of linear, melt-spinnable polyesters can be used: Assuming a free dicar acid, for example terephthalic acid, and a diol, for example ethylene glycol, from, is then directly esterified by conventional procedure initially and then polycondensed. If, instead of the free dicarboxylic acid, one of its esters is reacted with lower aliphatic alcohols, for example dimethyl terephthalate or diethyl terephthalate, and a diol such as, for example, ethylene glycol, it is first transesterified in a known manner and then polycondensed.

at a preferred embodiment the method according to the invention the polycondensation is carried out in two stages, wherein first a precondensate of dicarboxylic acid (s) or dicarboxylic acid diester, DOP addition compound (s) and diol (s) is prepared and the Precondensate subsequently in the presence of the other phosphorus-containing compounds) is condensed.

The polycondensation is preferably carried out in the presence of a catalyst, all known compounds for polyester production being suitable as catalysts, for example antimony trioxide, antimony triacetate, titanium tetrabutoxide, germanium oxide and heavy metal-free catalysts such as C94 ^™ from Acordis Industrial Fibers GmbH, Obernburg (DE) or Ecocat ^{TM of} the company Zimmer AG, Frankfurt / M. (DE).

The DOP addition compounds can in the form of their dioic esters, their free acids or in the form of their cyclic ones Anhydrides are added. Preferably, their addition is carried out in glycolic Solution.

to shortening the polycondensation time has proven to be advantageous small amounts of branching agents before the Reaktonsgemisch or while add to the polycondensation. As a branching agent especially suitable are pentaerythritol, trimethylolpropane and / or trimellitic acid.

ever according to purpose the copolyesters of the invention while the production also all for polyester usual additives be added. Preferably, the reaction mixture is at least added an additive which is selected from the group of Stabilizers, dyes, matting agents and nucleating agents (nucleating agents).

The available according to the invention Phosphorus-containing copolyesters have excellent whiteness of amorphous structure and show a softening point of between 80 and 150 ° C. The copolyesters with a total phosphorus content of 5 to 7% by weight are excellent masterbatch granules for the production of flame retardants equipped Fibers, filaments, monofilaments, films, films, moldings and hollow suitable in which the phosphorus content by processing with polyethylene terephthalate or slightly modified PET to between 0.4 and 0.7 wt .-% is reduced.

As already mentioned, can the masterbatch copolyesters of the invention according to all known in the art technologies with PET melts to copolyesters with reduced phosphorus content and statistical Distribution of the monomers are processed in the polymer chain.

The The invention is explained in more detail below with reference to the examples:

example 1

Copolyester with a Total phosphorus content of 5 wt .-%.

In one with stirrer, Reflux condenser and Nitrogen induction provided round bottom flask, 180 g of ethylene glycol submitted and at 120 ° C. heated. While 160 g of methylphospholane (2-methyl-2,5-dioxo-1-oxa-2-phospholane of formula I from the manufacturer CLARIANT) with stirring into the glycol. The temperature of the reaction mixture is maintained at 120 ° C.

616 g of terephthalic acid, 359 g Ukanol ^® RD ([2- (9,10-dihydro-9-oxa-10-oxide-10-phosphaphenantren-l0-yl) methyl-succinic acid] of the firm Schill + Seilacher AG, Böblingen ) and 300 g of ethylene glycol, a precondensate is prepared, which is converted into a suitable reactor for polyester polycondensation and heated to 260 ° C under a nitrogen atmosphere. At this temperature, 160 g of the glycolized methylphospholane and 0.52 g of antimony triacetate in the form of a glycolic solution are added to the precondensate. A vacuum of 266 Pa (2 torr) is applied and the temperature raised to 280 ° C. After 35 minutes, the pressure is reduced to 26.6 Pa (0.2 Torr) and the polycondensation is continued for 3 hours at 280 ° C.

Of the thus obtained copolyester has a relative viscosity of 1.63 (measured in m-cresol at 20 ° C in Form of a 1% solution) and a softening point of 150 ° C. The theoretical for this copolyester calculated phosphorus content is 5.28% by weight; indeed a total phosphorus content of 5.05 wt.% was found.

Example 2

Copolyester with a Total phosphorus content of 7 wt .-%.

481 g of terephthalic acid, 502.5 g Ukanol ^® RD and 350 g of ethylene glycol a precondensate is prepared and filled into a Polyesterpolykondensationsreaktor after the direct esterification process. The prepolymer is melted under nitrogen, heated to 260 ° C, and the melt are 129 g of glycolated methylphospholane (prepared as in Example 1) together with 207 g of phenylphosphinic acid (2-carboxy-ethyl (phenyl) -phosphinic Fa. Kolon (KR )) added. In addition, 0.03 g of titanium tetrabutoxide as a polycondensation catalyst and 0.45 g of trimellitic acid as a branching agent are added to the reaction mixture. Increasing the temperature to 282 ° C reduces the pressure to 39.9 Pa (0.3 Torr), and under these conditions the polycondensation is continued for a further 4 hours.

Receive becomes a slightly yellowish polymer with a relative solution viscosity of 1.61 (measured in m-cresol at 20 ° C in the form of a 1% solution) and with a softening point of 80 ° C. The calculated phosphorus content is 7% by weight; a total phosphorus content of 6.8% by weight was measured.

Example 3

Copolyester with a Total phosphorus content of 6 wt .-%.

19.6 kg of dimethyl terephthalate, 10 kg of ethylene glycol and 9.3 g of manganese (II) acetate in the form of a glycolic solution are introduced into a transesterification reactor and transesterified at temperatures of 160 to 220 ° C. After the theoretically required amount of methanol has been distilled off, the melt is transferred to a polycondensation reactor and the temperature is increased to 260 ° C. Now the prepolymer 4 g of phosphoric acid dissolved in glycol, and 15 minutes later 19.5 kg Ukanol ^® FR (9,10-dihydro-9-oxa-10- [2,3-di- (2-hydroxyethoxy) carbonylpropyl] -10-phosphaphenanthrene-10-oxide from Schill + Seilacher AG, Böblingen) in the form of a 60% solution in glycol and 8.6 kg of phenylphosphinic acid. 3.3 g of germanium dioxide in the form of a glycolic solution, 300 g of pentaerythritol as branching agent and 0.15 kg of titanium dioxide (matting agent) as a glycolic suspension are added to the melt as a polycondensation catalyst. The temperature is raised to 285 ° C and the pressure is reduced within 45 minutes to 26.6 Pa (0.2 Torr). After 3.5 hours, the polycondensation is stopped. It is obtained a granules of light inherent color, which has a relative solution viscosity of 1.64 (in m-cresol at 20 ° C in the form of a 1% solution) and a softening point of 120 ° C. The theoretical value for the total phosphorus content is 6.0 wt .-%, measured 5.85 wt .-%.

Example 4

example

36 kg ready-to-spin dried PET chips with a matting agent content of 0.3% titanium dioxide and a relative solution viscosity of 1.64, measured in m-cresol as a 1% solution at 20 ° C, were in a spider extruder, which was equipped with a mixing torpedo, melted. With The help of a side extruder was 4 kg of the copolyester according to example 3 registered in the melt, in the form of with 50 ppm of magnesium stearate powdered chips dried to a water content of 10 ppm, which have been melted and with a gear pump in the compression zone of the main extruder were metered.

The from the main extruder emerging melt mixture was at a Temperature of 282 ° C through a heated and equipped with static mixing elements line led to a POY spinning head and with a winding speed of 3500 m / min to partially directed Yarn ("POY" = partially oriented yarn) or multifilament in the denier 176 dtex / 36 f spun.

At The multifilament had a melting point of 247 ° C, a phosphorus content of 0.58 Wt .-% and a relative viscosity of 1.595 (in m-cresol as 1% solution at 20 ° C) measured.

To the draw was the resulting fully directional multifilament ("FOY" = fully oriented yarn) processed into tissue at which a LOI value (Limited Oxygen Index) of 29.5% oxygen was measured.

Claims (28)

Flame-retardant, phosphorus-containing copolyester having a total phosphorus content of 5 to 7 wt .-%, obtainable by a) esterification of at least one dicarboxylic acid with at least one diol and / or by transesterification of at least one dicarboxylic acid diester with at least one diol in the presence of (1) a flame-retardant bifunctional DOP Addition compound of the formula I

wherein R is a hydrogen atom, a C ₁ -C ₄ -alkyl group or a C ₁ -C ₄ -hydroxyalkyl group, and (2) at least one other, different from (1), bifunctional, phosphorus-containing compound; and b) polycondensation of the products formed or formed in the esterification and / or transesterification, the DOP addition compound providing at most 3.5% total phosphorus content, while the remainder of the total phosphorus content is derived from the at least one other bifunctional phosphorus containing compound , Copolyester according to Claim 1, characterized in that the at least one further bifunctional phosphorus-containing compound is 2-methyl-2,5-dioxo-1-oxa-2-phospholane of the formula II and / or 2-carboxyethyl (phenyl) phosphinic acid of Formula III is.

Copolyester according to Claim 1 or 2 by an intrinsic viscosity [η] of at least 0.5 measured at 20 ° C in m-cresol as solvent. Copolyester according to claim 3, characterized by an intrinsic viscosity number [η] of at least 0.6. Copolyester according to one of Claims 1 to 4, characterized that the at least one dicarboxylic acid terephthalic acid, isophthalic and / or 2,6-naphthalenedicarboxylic acid is. Copolyester according to Claim 5, characterized that the Proportion of terephthalic acid various dicarboxylic acids at the most 5 mol% of the total amount of dicarboxylic acids. Copolyester according to one of Claims 1 to 6, characterized that the at least one dicarboxylic acid diester at least one diester of at least one of the dicarboxylic acids according to claim 5 with at least one aliphatic alcohol having 1-4 C atoms is. Copolyester according to one of claims 1 to 7, characterized in that the at least one diol Ethylene glycol and / or 1,4-cyclohexanedimethanol. Copolyester according to one of Claims 1 to 8 through a softening range of 80 - 150 ° C. Copolyester according to one of claims 1 to 9 in the form of a masterbatch granules. Copolyester according to one of claims 1 to 9 in the form of a masterbatch melt. Use of the copolyester according to one of claims 1 to 11 as a masterbatch for the production of flame-resistant polyesters with a total phosphorus content of 0.4-0.7% by weight. Use according to claim 12 for the production of Polyester fibers, polyester filaments or monofilaments. Use according to claim 13 for the production of Fibers, filaments or monofilaments by the melt spinning process. Use according to claim 12 for the production of Polyester moldings or hollow bodies. A process for preparing a flame-retardant, phosphorus-containing copolyester having a total phosphorus content of 5 to 7 wt .-%, in particular according to one of claims 1 to 11, wherein a) at least one esterified dicarboxylic acid with at least one diol and / or at least one dicarboxylic acid diester with at least a diol is transesterified, in the presence of (1) a flame-retardant bifunctional DOP addition compound of the formula I.

in which R is a hydrogen atom, a C ₁ -C ₄ -alkyl group or a C ₁ -C ₄ -hydroxyalkyl group, and b) the products formed or formed during the esterification and / or transesterification are polycondensed, characterized in that the esterification and / or or transesterification in the presence of (2) at least one other bifunctional phosphorus-containing compound other than the DOP addition compound, and that the DOP addition compound is used in an amount corresponding to a total phosphorus content of the copolymer of at most 3.5% by weight. while the remainder of the total phosphorus content is provided by the at least one further difunctional phosphorus-containing compound. A method according to claim 16, characterized in that as at least one further bifunctional phosphorus-containing compound 2-methyl-2,5-dioxo-1-oxa-2-phospholane of the formula II and / or 2-carboxy-ethyl (phenyl) -phosphinic the Formula III is used.

Method according to claim 16 or 17, characterized that as dicarboxylic acid terephthalic acid, isophthalic and / or 2,6-naphthalenedicarboxylic acid is used. Method according to claim 18, characterized that the of terephthalic acid various dicarboxylic acids at the most Make up 5 mol% of the total amount of dicarboxylic acids. Method according to one of Claims 16 to 19, characterized that as dicarboxylate at least one diester of at least one of the dicarboxylic acids according to claim 18 with at least one aliphatic alcohol having 1-4 C atoms is used. Method according to one of Claims 16 to 20, characterized that as Diol ethylene glycol and / or 1,4-cyclohexanedimethanol is used. Method according to one of Claims 16 to 21, characterized that the Copolyester is prepared in the form of a masterbatch granules. Method according to one of Claims 16 to 21, characterized that the Copolyester is produced in the form of a masterbatch melt. Method according to one of Claims 16 to 23, characterized that the Polycondensation is carried out in two stages, with first one Precondensate of dicarboxylic acid (s) or dicarboxylic acid diester, DOP addition compound (s) and diol (s) is prepared and the Precondensate subsequently in the presence of the other phosphorus-containing compounds) is condensed. Method according to one of Claims 16 to 24, characterized that the Polycondensation is carried out in the presence of a catalyst. Method according to one of Claims 16 to 25, characterized that the DOP addition compound (s) in the form of their diol esters, free acids or cyclic anhydrides are added. Method according to one of Claims 16 to 26, characterized that the Reaction mixture before or during the polycondensation pentaerythritol, trimethylolpropane or trimellitic acid as Branching agent is added. Method according to one of Claims 16 to 27, characterized that the At least one additive is added to the reaction mixture, which is selected from the group of stabilizers, dyes, matting agents and nucleating agents.