MXPA01005930A - Copolyesters with antistatic properties and high clarity - Google Patents

Abstract

A novel copolyester composition is provided comprising a copolyester having a melting point less than 250°C and a quaternary ammonium salt having thermal stability at temperatures greater than 200°C wherein the composition is characterized as having both antistatic and clarity properties.

Description

COPOL ESTERS WITH ANTISTATIC PROPERTIES AND HIGH CLARITY DESCRIPTION OF THE INVENTION This application claims priority over provisional application Serial No. 60 / 112,907 filed on December 18, 1998, and application 60 / 112,907 is incorporated herein for this reference In its whole. The present invention relates to a composition comprising a copolyester having a melting point lower than 250 ° C and a specified antistatic agent. The composition can be blended with the same or another homo or copolyester to provide films, sheets and thermoformed articles having excellent clarity and antistatic properties. Polyesters are widely used as extrusion and injection molding resins for applications such as fibers, films, food and beverage containers and the like. Commonly used polyesters include polyethylene terephthalate (PET), poly-1,4-butylene terephthalate (PBT), and poly-1,4-cyclohexamethylene terephthalate (PCT). Copolyesters are frequently used when special properties such as lower processing temperatures, clarity or inhibited crystallization are needed. Polyesters as well as other synthetic polymers are electrically deficient conductors. In this way, during the extrusion, processing or handling of such polymers, static charges can accumulate. This is especially true under conditions of low relative humidity. Such a static charge is highly undesirable as it can cause material handling problems during processing, lead to shocks when handling molded parts, lead to dust collection in packages, and cause damage to the sensitive electronic parts that are stored in plastic packaging due to the dissipation of the static charge. Therefore, it can be advantageous if thermoplastic polyesters having good antistatic properties can be provided. There are many antistatic additives available for use in thermoplastic polymers including polyesters. To be effective as antistatic, some of these additives need to be used in such a high concentration that they impart an appearance of undesirable haze for the film, sheet or molded article. In accordance with this invention, compositions comprising certain antistatic and copolymer additives are described which provide an unexpected combination of antistatic behavior and clarity in the films, sheets or molded articles produced from the compositions. The amount of the antistatic agent is from about 0.6 to about 1.5 weight percent, based on the total composition. Any copolyester having a melting point of less than 250 ° C can be used. Preferably the copolyester used is based on terephthalic acid, naphthalenedicarboxylic acid and / or 1,4-cyclohexanedicarboxylic acid and contains about 10 to about 90 mol% ethylene glycol and about 90 to about 10 mol% of other glycols. Antistatic agents are quaternary ammonium salts that have thermal stability at temperatures above 200 ° C. Examples are quaternary ammonium alkylbenzene sulfonate salts, quaternary ammonium alkan sulfonate salts and the like. Specific examples include octyldimethylhydroxyethylammonium dodecylbenzenesulfonate and octyldimethylhydroxyethylammonium methanesulfonate. Other compounds of this type are listed in U.S. Patent Nos. 4,904,82: 5, 5,053,531 and 5,187,214. Some of these materials are commercially available from BASF Corporation. The novel compositions of the present invention comprise any copolyester having a melting point lower than 250 ° C and an antistatic agent. As used herein, the copolyester is any polyester that contains two or more types of repeating unit. The antistatic agent is present in an amount of about 0.6 to about 1.5% by weight, more preferably in an amount of about 0.75 to about 1.5% by weight, based on the final composition. Preferred copolyesters include not exclusively amorphous, linear, thermoplastic or crystalline copolyesters produced by conventional polymerization techniques of one or more diols with one or more dicarboxylic acids or one or more dicarboxylic acids with do's or more diols. Exemplary diol components of the described copolyesters can be selected from ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1, 2-cyclohexanediol, 1,4-cyclohexanediol, 1/2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, Z, 8-bis (hydroxymethyl) -trichyclo- [5.2.1.0] -decano wherein Z represents 3, 4 or 5; and diols containing one or more oxygen atoms in the chain, for example diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and the like. In general, these diols contain 2 to 18, preferably 2 to 8 carbon atoms. Either cycloaliphatic diols can be used in their cis or trans configuration or as mixtures of both forms. The exemplary acid components (aliphatic, alicyclic, or aromatic dicarboxylic acids) of the linear co-ester, for example, of terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, succinic acid, glutaric acid, are selected. , adipic acid, sebacic acid, acid, 12-dodecanedioic acid, 2,6-naphthalenedicarboxylic acid and the like. In the preparation of a polymer, it is often preferable to use a functional acid derivative thereof such as the dimethyl, diethyl or dipropyl ester of the dicarboxylic acid. The anhydrides or acid halides of these acids can be used in practice. Linear copolyesters can be prepared according to the conditions of copolyester formation well known in the art. For example, a mixture of one or more dicarboxylic acids, preferably aromatic dicarboxylic acids, or ester forming derivatives thereof, and one or more diols can be heated in the presence of esterification and / or polyesterification catalysts to temperatures in the range of about 150 ° C to about 300 ° C, and pressures from the atmospheric to about 0.2 mm Hg. Normally, the dicarboxylic acids or their derivatives are esterified or transesterified with the diols at atmospheric pressure and at a temperature at the lower end of the specified range. Polycondensation is then effected by increasing the temperature and decreasing the pressure while removing the excess diol from the mixture.

Exemplary copolyesters useful in the practice of this invention include copolyesters of terephthalate, naphthalenedicarboxylate and 1,4-cyclohexanedicarboxylate containing portions of ethylene glycol and 1,4-cyclohexanedimethanol (CHDM). The concentrations of CHDM will generally be in the range of about 10 to about 60 mol%. The copolyesters will generally contain at least 80% by mol of portions of terephthalic acid, naphthalenedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid. They can be used if mixtures of acids are desired. In addition, from 0 to about 20% mol of other acids can be used. Preferred modification acids include those containing about 4 to about 40 carbon atoms such as succinic, glutaric, adipic, sebacic, suberic, isophthalic and the like acids, and mixtures thereof. Modifying acids are defined herein as acids that are not present as a majority of the acid component of the copolyester. In addition, other glycols may be used in amounts of about 10 to about 90 mol%. The other glycols include those containing about 3 to about 12 carbon atoms such as 1,3-propanediol, propylene glycol, 1,4-butane diol, 1,6-hexanediol, neopentyl glycol, 2,2,4,4-tetramethyl-1 , 3- cyclobutanediol, diethylene glycol, polyethylene glycol and the like and mixtures thereof. Small amounts of branching agents such as trimellitic acid, pyromellitic dianhydride, trimethylolpropane, pentaerythritol and the like can be used.

Generally, less than about 2 mol% of such branching agents can be used. Preferred copolyesters used herein comprise about 100 mole percent terephthalic acid, about 40 to about 90 mole percent ethylene glycol, and about 10 to about 60 mole percent CHDM. More preferred are copolyesters comprising about 100 mole percent terephthalic acid, about 65 to about 75 mole percent ethylene glycol and about 25 to about 35 mole percent CHDM. Preferred copolyesters for use herein comprise about 100 mole percent Leo tereph acid, about 40 to about 90 mole percent ethylene glycol, and about 1Q to about 60 mole percent neopentyl glycol (NPG). More preferred are copolyesters comprising about 100 mole percent terephthalic acid, about 60 to about 80 mole percent ethylene glycol, and about 20 to about 40 mole percent NPG. Preferred copolyesters for use herein comprise about 10 to about 50 mole percent isophthalic acid, about 50 to about 90 mole percent terephthalic acid, and about 100 mole percent CHDM. More preferred are copolyesters comprising about 15 to about 40 mole percent isophthalic acid, about 60 to about 85 mole percent terephthalic acid, and about 100 mole percent CHDM. The mole percentages of the diol component of the copolyester of the invention are 100% by total mole. The mole percentages of the acid component of the copolyester of the invention is 100% in total mol. Small amounts of branching agents such as trimellitic acid, pyromellitic dianhydride, trimethylolpropane, pentaerythritol and the like can be used. Generally less than about 2 mole% of such branching agents can be used. The CHDM and 1,4-cyclohexanedicarboxylic components may be in the cis form, the trans form, or a mixture of the cis and trans isomers. The acid portion can be derived from the acid or a suitable synthetic equivalent such as a lower alkyl ester. Dimethyl esters are widely used to make polyesters. The naphthalenedicarboxylate portion is generally derived from acid 2, 6-naphthalenedicarboxylic acid or its lower alkyl esters containing 1 to 4 carbon atoms. However, other isomers of naphthalenedicarboxylic acid or mixtures of isomers may be used if desired. The preferred isomers are the 2,6-, 2,7-, 1,4- and 1,5- isomers. Antistatic agents are quaternary ammonium salts that have thermal stability at temperatures above 200 ° C. Examples are the quaternary ammonium alkylbenzene sulphonate salts, quaternary ammonium alkanolammonium salts and the like. Specific examples include octyldimethylhydroxyethylammonium dodecylbenzenesulfonate and octyldimethylhydroxyethylammonium methanesulfonate. Other compounds of this type are listed in U.S. Patent Nos. 4,904,825, 5,053,531 and 5,187,214. Additional examples of suitable antistatic agents for use herein are represented by the following formula: R. I R -N + -R3 Y ' Ri wherein R is a C2-C22 alkyl, preferably a C8-C8 alkyl, and Ri is selected from the group consisting of C?-C22 alkyl and an alkyleneoxy radical, "Z" may be represented by the formula, t-CH2-C (A) H-0] xH, wherein A is hydrogen, methyl or ethyl, and x is an integer of 1-5, eg, hydroxyethyl, hydroxypropyl, hydroxybutyl, poly (ethylenedioxyhydroxyethyl), poly (propyleneoxy) 2-hydroxypropyl and poly (butyleneoxy) 2-hydroxybutyl. Preferably R is selected from the group consisting of C 1 -C 3 alkyl or C 8 -C 8 alkyl, for example methyl, ethyl, n-propyl, isopropyl, octyl, decyl, dodecyl, hexadecyl and octadecyl, or the alkylenoxy radical. Z wherein A is hydrogen or methyl and x is 1 to 3. Still more preferably, Ri is a C?-C3 alkyl or a Z alkyleneoxy radical wherein A is hydrogen and x is 1 to 2. When x is greater than 1, The sulfonate compound can be liquid, which makes it easier to handle. R 2 in the above formula is selected from the group consisting of C 1 -C 3 alkyl, for example methyl, ethyl, n-propyl and isopropyl, and the radical Z, wherein a and x are as defined with respect to Ri. Alternatively Ri and R2 can also be linked together to form a six-membered morpholino group. R3 in the above formula is a group represented by the alkylenoxy radical Z, wherein A and x are as defined with respect to Rx; and Y is the anion, R'S03, wherein R 'is an alkyl of preferably a C 1 -C 2 alkyl, for example methyl and ethyl rhipidium or a C 8 -C 18 alkylphenyl, preferably a C 10 -C 13 alkylphenyl. Preferably, the alkylphenyl is a para-alkylphenyl. With respect to R, R? and R ', the term alkyl denotes a univalent alkyl group, essentially straight or branched saturated chain. Representative of such alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, isohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecl, octadecyl, soy, eicosyl, and the like. When derived from materials that occur naturally, the group R, Ri and R 'may contain a small amount of unsaturation and may be comprised of a mixture of alkyl groups. For example, a commercially available dodecylbenzenesulfonic acid is a benzenesulfonic acid in which the alkyl substituent on the benzene ring is a mixture of the C? 0-C? 3 alkyl groups / the nominal number of carbon atoms which is about 12. It has been discovered that copolyester compositions containing the antistatic agent can be easily prepared using any conventional mixing equipment such as single screw extruders, twin screw extruders, Brabender Plastographs, Sigma blade mixers and the like. In addition, the copolyester compositions of a master batch can be prepared, which is brought to the desired concentration. These compositions are generally prepared at melt temperatures of about 200 to about 250 ° C. Generally, it is desirable: to use a processing temperature as low as possible since the degradation of these antistatic additives and a corresponding yellow dye discoloration of the extrudate may be appreciable at temperatures of about 250 ° C and more. The extrusion of a single screw is the most common processing equipment used to produce a film, sheet and molded articles. The copolyesters of this invention are well known and many of them are commercially available from Eastman Chemical Company. Methods for their preparation are described in U.S. Patents 2,465,319 and 3,047,539. Useful polyesters and copolyesters will have inherent viscosity values (V.I.) of about 0.5 dl / g to about 1.5 dl / g, but those with values of about 0.6 dl / g to about 1.0 dl / g are preferred. The inherent viscosity is deteed in a 60/40 (w / w) solution of phenol / tetrachloroethane at a concentration of 0.5 grams per 100 ml at 25 ° C. The melting point as defined herein is measured by the DSC (differential scanning calorimetry) analysis. DSC measurements are made, at a sweep ratio of 20 ° C / min. The antistatic compositions of the invention are thermally stable at temperatures in excess of 200 ° C. The thermal stability is weight loss of less than 5 weight percent when heated to temperatures up to about 275 ° C. The agents described above have antistatic agent concentrations of from about 0.6 to about 1.5% by weight with preferred concentrations including from about 0.75 to about 1.5 weight percent in the final composition. The film, sheet or clear non-colored thermoformed articles will result from the use of these compositions. Although not required, additives normally used in copolyesters can be used if desired. Such additives include colorants, dyes, pigments, fillers, antioxidants, stabilizers, flame retardants, impact modifiers, buffers and the like. A preferred embodiment is one or more shaped articles of one or more copolyesters of the invention. Even more preferably, the shaped article can be selected from the group consisting of films, fibers, foam objects and molded objects. It is preferred that the shaped article be a film. This film can be produced by any method known in the art, for example, by a meltblowing process, a solvent molding process, a melt extrusion process or a melt extrusion process followed by orientation uniaxial or biaxial. Another preferred embodiment of this invention is a process for preparing the copolyester composition of this invention wherein the antistatic agent of the invention is blended or blended with the copolyester of the invention. For the purpose of this invention, a masterbatch is defined as by any ordinary person skilled in the art. More particularly, a master batch is a composition comprising a polymer and an antistatic agent wherein the concentration of the antistatic agent is higher than that desired in the final product, and whose composition is carried in the same or another polymer to produce a final product with the desired concentration of the antistatic agent. The copolyester compositions of this invention are useful in applications where antistatic and clarity properties are required. The compositions are useful as a monostratified film, mono-laminated sheet, as a layer in a multi-layered film or multi-stree: foil and thermoformed articles produced from the film or sheet such as a clam shell pack. All percentages expressed herein refer to percentages by weight unless otherwise specified. This invention may be further illustrated by the following examples of preferred embodiments thereof, although it will be understood that these examples are included simply for purposes of illustration and are not intended to limit the scope of the invention unless specifically indicated otherwise. EXAMPLES In the examples, the following is indicated. The antistatic Larostat HTS 905A is a quaternary ammonium sulfonate salt, sold under the trademark of BASF Corporation. Eastar PETG 6763 is a copolyester based on terephthalic acid, ethylene glycol, and 1,4-cyclohexanedimethanol, produced and sold by Eastman Chemical Company. The copolyester is PETG containing 12 mol% of CHDM, 88 mol% of ethylene glycol and 100 mol% of tereftáli.co acid. Example 1 A master batch consisting of 4.8 percent er is prepared. weight of the antistatic Larostat HTS 905A and 95.2% by weight a polyethylene terephthalate copolyester containing 12 mole percent of CHDM using a Werner double screw extruder &; Pfleiderer 40 mm. The masterbatch is then mixed via a granule-granule mixture with Eastar PETG 6763 polyester and subsequently extruded into a 20 mil sheet using a 1.5 inch (3.81 cm) 24: 1 Killion screw extruder. The properties of the measured extruded film samples including surface resistivity, color, nebulosity and light transmission are given in Table 1.1. These results show that when the load of the antistatic Larostat HTS 905A is greater than or equal to 0.67% by weight, then the film is antistatic (ie, the surface resistivity is less than 1012 ohms / sq) even at 12% relative humidity. The results also show that the film is clear (ie, the haze is less than 10%) when the load of the antistatic Larostac HTS 905A is less than or equal to 1.47% by weight. In this way, there is a specific range of the antistatic Larostat HTS 905A in the copolyesters that will produce a clear and antistatic film. Table 1.1 1 EOS / ESD Sil.11 Measurement of surface resistivity of static dissipative planar materials 2 ASTM D2244-93 Standard Test Method for Calculation of Color Differences of color coordinates instrumentally measured 3 ASTM D1003-97 Standard Test Method for nebulosity and light transmission of transparent plastics. The invention has been described in detail with particular reference to the preferred embodiments thereof, but it will be understood that modifications and variations may be made within the spirit and scope of the invention. On the other hand, all of the patents, patent applications, provisional patent applications and literature references cited above are incorporated herein for reference to any description pertinent to the practice of this invention.

Claims (34)

1. CLAIMS 1. A copolyester composition characterized in that it comprises a copolyester having a melting point of less than 250 ° C and and a quaternary ammonium salt having thermal stability at a temperature higher than 200 ° C, wherein the quaternary ammonium salt it is present in an amount in the range of more than 0.6 to about 1.5 weight percent, based on the weight of the total composition.
2. 2. The copolyester composition according to claim 1, characterized in that the quaternary ammonium salt is a quaternary ammonium alkobenzene sulfonate.
3. 3. The copolyester composition according to claim 1, characterized in that the quaternary ammonium salt is a quaternary ammonium alcansulfonate salt.
4. 4. The copolyester composition according to claim 1, characterized in that the quaternary ammonium salt is octyldimethylhydroxyethylammonium dodecylbenzenesulfonate.
5. 5. The copolyester composition according to claim 1, characterized in that the quaternary ammonium salt is octyl dimethyl lydroxyethyl ammonium methanesulfonate.
6. 6. The copolyester composition according to claim 1, characterized in that the quaternary ammonium salt is selected from compounds represented by the following formula: I R-N + -R3 Y 'I R2 wherein R is a C2-C22 alkyl, Ri is selected from the group consisting of a Cx-C22 alkyl and an alkylenoxy radical. { -CH2-C (A) H- ?} x H, R 2 is selected from the group consisting of C 1 -C 3 alkyl and the radical. { -CH2-C (A) H- ?} xH or R2 can be linked together with Rj. to form a morpholino group, R3 is a radical. { -CH2-C (A) H- ?} xH, Y 'is the anion R'S03 wherein R' is selected from the group consisting of C 1 -C 18 alkyl and C 8 -C 8 alkylphenyl, wherein AA is selected from hydrogene, methyl and ethyl and x is 1
7. 7. The copolyester composition according to claim 1, characterized in that the quaternary ammonium salt having thermal stability at a temperature greater than 200 ° C is present in an amount in the range of from about 0.75 to about 1.5 percent by weight. weight.
8. 8. The copolyester composition according to claim 1, characterized in that the copolyester comprises one or more diols with two or more dicarboxylic acids, or one or more dicarboxylic acids with two or more diols.
9. 9. The copolyester composition according to claim 8, characterized in that one or more diols are selected from the group consisting of ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,2-propanediol, 1,3-propanediol, 1, 4 -butanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, Z, 8-bis (hydroxymethyl) -tricyclo [5.2.1.0] -decano where Z represents 3, 4 or 5; diethylene glycol, triethylene glycol, dipropylene glycol, and tripropylene glycol.
10. 10. The copolyester composition according to claim 8, characterized in that the diols comprise 2 to 18 carbon atoms.
11. 11. The copolyester composition according to claim 10, characterized in that the diols comprise 2 to 8 carbon atoms.
12. 12. The copolyester composition according to claim 8, characterized in that one or more acids are selected from the group consisting of terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, succinic acid, glutaric, adipic acid, sebacic acid, 1,2-dodecanedioic acid and 2,6-naphthalenedicarboxylic acid.
13. The copolyester composition according to claim 12, characterized in that the acids comprise one or more of terephthalic acid, naphthalenedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid.
14. 14. The copolyester composition according to claim 13, characterized in that the terephthalic acid, naphthalenedicarboxylic acid or acid 1, 4-cyclohexanedicarboxylic acid are independently present in about 80% mol or more.
15. 15. The copolyester composition according to claim 9, characterized in that the acids comprise one or more of • terephthalic acid, naphthalenedicarboxylic acid and 1-cyclohexanedicarboxylic acid and wherein the diols comprise one or more of ethylene glycol and 1, 4 - cyclohexanedimethanol.
16. 16. The copolyester composition according to claim 9, characterized in that one of the diols is independently present in the amount of about 10 to about 90 mol%.
17. 17. The copolyester composition according to claim 16, characterized in that the diol is 1,4-cyclohexanedimethanol.
18. 18. The copolyester composition according to claim 17, characterized in that 1,4-cyclohexanedimethanol is present in about 10 to about 60 mol%.
19. 19. The copolyester composition according to claim 15, characterized in that the terephthalic acid, naphthalenedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid are independently present in about 80 mol% or more.
20. 20. The copolyester composition according to claim 1, characterized in that the copolyester comprises about 100 mole percent terephthalic acid, about 40 to about 90 mole percent ethylene glycol, and about 10 to about 60 mole percent. of 1,4-cyclohexanedimethanol.
21. The copolyester composition according to claim 20, characterized in that the copolyester comprises about 100 mole percent terephthalic acid, about 65 to about 75 mole percent ethylene glycol, and about 25 to about 35 mole percent of 1,4-cyclohexandi ethanol.
22. 22. The copolyester composition according to claim 1, characterized in that the copolyester comprises about 100 mole percent terephthalic acid, about 40 to about 90 mole percent ethylene glycol, and about 10 to about 60 mole percent. of neopentyl glycol.
23. The copolyester composition according to claim 22, characterized in that the copolyester comprises about 100 mole percent terephthalic acid, about 60 to about 80 mole percent ethylene glycol, and about 20 to about 40 mole percent of neopentyl glycol.
24. The copolyester composition according to claim 1, characterized in that the copolyester comprises about 10 to about 50 mole percent isophthalic acid, about 50 to about 90 mole percent terephthalic acid, and about 100 percent mole mol of 1,4-cyclohexanedimethanol.
25. 25. The copolyester composition according to claim 1, characterized in that the copolyester comprises one or more branching agents selected from the group consisting of trimellitic acid, pyromellitic dianhydride, trimethylolpropane, and pentaerythritol.
26. The copolyester composition according to claim 1, characterized in that the copolyester has an inherent viscosity of about 0.5 to about 1.5 dl / g as determined in a 60/40 (w / w) solution of phenol / tetrachloroethane in a concentration of 0.5 grams per 100 ml at 25 ° C.
27. 27. The copolyester composition according to claim 26, characterized in that the copolyester has an inherent viscosity of about 0.6 to about 1.0 dl / g as determined in a 60/40 (w / w) solution of phenol / tetrachloroethane in a concentration of 0.5 grams per 100 ml at 25 ° C.
28. 28. A shaped article prepared from a copolyester composition according to claim 1, characterized in that it is selected from the group consisting of films, sheets, fibers, foam objects and molded objects.
29. 29. The shaped article according to claim 28, characterized in that the shaped article is a film.
30. 30. The shaped article according to claim 29, characterized in that the film is produced by a meltblowing process, a solvent molding process, a melt extrusion process or a melt extrusion process followed by uniaxial or biaxial orientation.
31. 31. The shaped article according to claim 28, characterized in that it comprises a multi-layered film wherein at least one layer comprises the composition according to claim 1.
32. 32. The shaped article according to claim 28, characterized in that it comprises a sheet further comprising the composition according to claim 1.
33. 33. The shaped article according to claim 32, characterized in that it comprises a multi-sheetratified wherein at least one layer comprises the composition according to claim 1.
34. 34. The process for the manufacture of a polyester composition according to claim 1, characterized in that it comprises mixing or diffusing the quaternary ammonium salt and the copolyester