DE19904188A1 - Polyester blends with an improved tendency to crystallize - Google Patents

Abstract

The invention relates to thermoplastic polyester molding materials which contain A) 30 to 100 wt.-% polyesters which consist of a 1) 50 to 99 wt.-% of a polybutylene terephthalate with a conte nt in a Lewis acidic inorganic or organic metal compound in the range of from 65 to 100 ppm (based on the metal), and a2) 1 to 50 wt.-% of polyesters that are not polybutylene terephthalate, B ) 0 to 40 wt.-% of rubber-elastic polymers, C) 0 to 30 wt.-% of flame-retardants, D) 0 to 50 wt.-% of fillers and E) 0 to 20 wt .-% of further additives. The invention is further characterized in that the total of the weight percentage of components A) to E) invariably is 100.

Description

The invention relates to thermoplastic polyester molding compositions, containing ent

• A) 30 to 100% by weight of polyesters, composed of
  • 1. 50 to 99% by weight of polybutylene terephthalate with a content of a Lewis acidic inorganic or organic metal compound in the range from 65 to 100 ppm (based on the metal), and
  • 2. 1 to 50% by weight of polyesters other than polybutylene terephthalate,
• B) 0 to 40% by weight of rubber-elastic polymers,
• C) 0 to 30% by weight of flame retardants,
• D) 0 to 50% by weight of fillers and
• E) 0 to 20% by weight of other additives, where the sum of the percentages by weight of components A) to E) always results in 100.

The invention also relates to the use of the fiction according molding compositions for the production of fibers, films and mold bodies as well as the molded bodies of any kind available here.

Polyesters are characterized by low water absorption and due to good dimensional stability and solvent resistance the end.

Mixtures of polyesters with other additives and ver drive for their production have long been known. Particularly Polybutylene terephthalate is often used among the polyesters because of its good mechanical and rheological properties and which can be processed more economically than other polyesters resorted to.

The production of polybutylene terephthalates can be reason can also be divided into two process steps, transesterification and polycondensation. Usually both procedures are used stages carried out in the presence of a catalyst. At the be Particularly frequently used catalysts are Titanium compounds, preferably titanium which is soluble in butane-1,4-diol compounds such as titanium alcoholates, which are both the transesterification as well as can support the polycondensation reaction (see a. Kunststoff-Handbuch 3/1, ed. G. W. Becker, D. Braun, Hanser-Ver lag, 1992, Munich, pages 12 to 23).

In the patents US 3,936,421 and 4,329,444 ge Suitable catalysts for the production of polybutylene terephthalate antimony, tin and titanium compounds described. For example, dibutyltin oxide, tin tetraethyl, Dibutyltin dichloride, dibutyltin maleate or laurate, antimony oxide as well as tetrabutyl orthotitanate, tetraoctyl titanate and triethanol amine titanate. A suitable amount of catalyst is specified in those mentioned Documents a range of 0.001 to 0.5 wt .-% disclosed (this corresponds to a proportion of 1.4 to 700 ppm, based on the Me tall, with tetraorthotitanate as a catalyst). When it is too low Amount of catalyst worsens the space-time yield al But sustainable, so that the production of z. B. polybutylene terephthalate from an economic point of view in the technical Scale no longer makes sense.

In the case of commercially available polyester molding compounds, for example based on polybutylene terephthalate, one observes Deterioration in processing when PBT is mixed with others ren polyesters is present as a polymer matrix.

The cycle time when processing semi-crystalline polyester is significantly influenced by the crystallization. The crystal lization is characterized by T (KB), the beginning of the crystal lization and T (KM), the temperature of maximum crystallization, and the half width of the crystallization peak. These values can be determined by means of DSC during cooling. The higher the Crystallization temperature and the narrower the width of the Kri stallization, the faster a melt solidifies in the mold and can then be removed from the mold earlier.

PBT itself has good crystallization behavior, however deteriorates in a mixture with other polyesters such as polycarbonate The tendency to crystallize increases drastically.

The object of the present invention was therefore to find blends based on of PBT with other polyesters available, which a better tendency to crystallize and consequently a better one Show processing (lower cycle time).

Accordingly, the polyester molding compositions defined at the outset were ge found. Preferred embodiments are dependent on the subclaims remove.

The molding compositions according to the invention contain 30 as component A) up to 100, preferably 50 to 98.99 and particularly preferably 30 to 70 % By weight of thermoplastic polyesters.

The thermoplastic polyesters are composed of 50 to 99, preferably 70 to 95 and particularly preferably 75 to 90% by weight of polybutylene terephthalate containing a Lewis acid inorganic or organic metal compound in the range of 65 up to 100 ppm (based on the metal).

In addition, component A) contains 1 to 50, preferably 5 to 30 and particularly preferably 10 to 25 wt .-% of polyesters, the are different from polybutylene terephthalate.

Suitable polybutylene terephthalates go back to Butane-1,4-diol as an aliphatic dihydroxy compound and Terephthalic acid as an aromatic dicarboxylic acid, with up to 10 mol% of the aromatic dicarboxylic acid by other aromatic Dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid or isophthalic acid or mixtures thereof or by aliphatic or cyclo aliphatic dicarboxylic acids such as adipic acid, azelaic acid or Cyclohexanedicarboxylic acid can be replaced. Furthermore can Butane-1,4-diol in polybutylene terephthalate by z. B. Hexane-1,6-diol and / or 5-methyl-pentane-1,5-diol in amounts up to 0.75% by weight, based on the total weight of the poly used butylene terephthalate.

The viscosity number of the polybutylene of the invention terephthalate generally ranges from 80 to 180 and preferably from 95 to 150 ml / g (determined according to ISO 1628 in a 0.5% by weight solution in a phenol / o-dichlorobenzene mixed (1: 1) at 25 ° C).

The carboxyl end group content of the polybutylenes in question terephthalate is usually no greater than 60, preferred 1 not greater than 40 and in particular not greater than 30 meq / kg. The carboxyl end group content is usually determined by titration procedure (e.g. by means of potentiometry).

Mixtures of these can also be used as polybutylene terephthalates Connections are used that relate to Differentiate between viscosity number and carboxyl end group content.

The polybutylene terephthalate according to the invention is made according to known methods Process using catalysts that have the Transesterification and optionally also the polycondensation reaction speed up, preserve. Suitable as catalysts are for Example Lewis acidic inorganic or organic metal compounds, for example on the basis of metallic Elements of groups IB, IIB, IVA, IVB, VA, VB or VIIIB of the Pe periodic system of the elements. For example, those in the Pa tentschrift US-A 3,936,421 mentioned catalytically active organi and inorganic titanium, tin and antimony compounds in Consideration. Organic tin and titanium are particularly suitable compounds such as tin tetraethyl, dibutyltin dichloride, dibutyl tin maleate or laurate and tetrabutyl orthotitanate, tetraoctyl titanate or triethanolamine titanate.

The content of catalyst compounds, such as those mentioned, in the polybutylene terephthalates according to the invention is in the range of 65 to 100 ppm (based on the metal of the catalyst used tors). Polyester molding compounds in which this is used are preferred dete polybutylene terephthalate contains z. B. organic or inorganic titanium, tin, zinc or antimony compounds in the range from 71 to 95 and especially from 73 to 80 ppm shows.

Generally, as other than polybutylene terephthalate Polyester based on aromatic dicarboxylic acids and an aliphatic or aromatic dihydroxy compound used.

A first group of preferred polyesters are polyalkylene tereph thalates with 2 and 3 and 5 to 10 carbon atoms in the alkylene chain of the alcohol part.

Such polyalkylene terephthalates are known per se and are described in the literature. They contain an aromatic ring in the main chain that comes from the aromatic dicarboxylic acid. The aromatic ring can also be substituted, e.g. B. by Ha logen such as chlorine and bromine or by C ₁ -C ₄ alkyl groups such as methyl, ethyl, i- or n-propyl and n-, i- or t-butyl groups.

These polyalkylene terephthalates can be obtained by reacting aroma table dicarboxylic acids, their esters or other ester-forming Derivatives with aliphatic dihydroxy compounds in per se be can be produced in a known manner.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid, Terephthalic acid and isophthalic acid or mixtures thereof nen. Up to 30 mol%, preferably not more than 10 mol% of the aromatic dicarboxylic acids can be aliphatic or cyclo aliphatic dicarboxylic acids such as adipic acid, azelaic acid, Sebacic acid, dodecanedioic acids and cyclohexanedicarboxylic acids are set.

Of the aliphatic dihydroxy compounds, diols with 2, 3, 5 or 6 carbon atoms, especially 1,2-ethanediol, 1,3-propanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethylanol and neopentyl glycol or their Mixtures preferred.

Particularly preferred polyesters are polyalkylene terephthalates, derived from alkanediols with 2, 3, 5 or 6 carbon atoms, too to name. Of these, in particular, polyethylene terephthalate, Polypropylene terephthalate or mixtures thereof are preferred. Further PET is preferred, which is up to 1 wt .-%, preferably up to to 0.75 wt .-% 1,6-hexanediol and / or 5-methyl-1,5-pentanediol as contains further monomer units.

The viscosity number of those other than polybutylene terephthalate Polyester is generally in the range from 50 to 220, preferably from 60 to 160 (measured in a 0.5% by weight Solution in a phenol / o-dichlorobenzene mixture (weight ratio 1: 1 at 25 ° C) according to ISO 1628).

Particularly preferred are polyesters, their carboxyl end groups content up to 100 meq / kg, preferably up to 50 meq / kg and ins especially up to 40 meq / kg polyester. Such poly Esters can, for example, by the method of DE-A 44 01 055 getting produced. The carboxyl end group content becomes more common wisely determined by titration methods (e.g. potentiometry).

Preferred molding compositions contain a mixture as component A) made of polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). The proportion of polyethylene terephthalate is preferred wise in the mixture 1 to 50, in particular 10 to 30 wt .-%, 1 based on 100% by weight of A).

It is also possible to use PET recyclates (also called scrap PET) to be used in a mixture with polybutylene terephthalate.

Recyclates are generally understood to mean:

• 1. So-called post industrial recyclate: this is Production waste from polycondensation or from Ver work z. B. sprues in injection molding, start-up ware in injection molding or extrusion or edge sections of extruded sheets or foils.
• 2. Post consumer recyclate: this is art fabric items that are after use by the end consumer collected and processed. In terms of quantity, by far the dominant articles are blow-molded PET bottles for refills ral water, soft drinks and juices.

Both types of recycled material can be used either as regrind or in the form of granules are present. In the latter case, the tubular cyclates melted in an extruder after separation and purification zen and granulated. This mostly reduces the handling that Flowability and dosability for further processing steps relieved.

Both granulated and recycled materials in the form of regrind can be used, whereby the maximum edge length is 6 mm, should preferably be less than 5 mm.

Due to the hydrolytic cleavage of polyesters at Ver processing (due to traces of moisture), it is recommended that the Re to pre-dry cyclate. The residual moisture content after drying is preferably 0.01 to 0.7, in particular 0.2 to 0.6%.

Furthermore, esters other than PBT are fully aromatic To mention polyesters, which differ from aromatic dicarboxylic acids and Derive aromatic dihydroxy compounds.

As aromatic dicarboxylic acids are already suitable for the Polyalkylene terephthalates described compounds. Preferred are mixtures of 5 to 100 mol% isophthalic acid and 0 to 95 mol% terephthalic acid, especially mixtures of about 80% Terephthalic acid with 20% isophthalic acid to about equivalent Mixtures of these two acids are used.

The aromatic dihydroxy compounds preferably have the general formula (I)

in which Z is an alkylene or cycloalkylene group with up to 8 carbon atoms, an arylene group with up to 12 carbon atoms, a carbonyl group, a sulfonyl group, an oxygen or sulfur atom or a chemical bond and in which m is the value 0 to 2 has. The compounds I can also _{carry C 1} -C ₆ -alkyl or alkoxy groups and fluorine, chlorine or bromine as substituents on the phenylene groups.

As the main body of these compounds, for example
Dihydroxydiphenyl,
Di- (hydroxyphenyl) alkane,
Di- (hydroxyphenyl) cycloalkane,
Di- (hydroxyphenyl) sulfide,
Di- (hydroxyphenyl) ether,
Di- (hydroxyphenyl) ketone,
di- (hydroxyphenyl) sulfoxide,
α, α'-di (hydroxyphenyl) dialkylbenzene,
Di- (hydroxyphenyl) sulfone, di- (hydroxybenzoyl) benzene
Resorcinol and
Hydroquinone and their ring-alkylated or ring-halogenated derivatives are called.

Of these will be
4,4'-dihydroxydiphenyl,
2,4-di (4'-hydroxyphenyl) -2-methylbutane
α, α'-di- (4-hydroxyphenyl) -p-diisopropylbenzene,
2,2-di (3'-methyl-4'-hydroxyphenyl) propane and
2,2-di- (3'-chloro-4'-hydroxyphenyl) propane,
as well as in particular
2,2-di (4'-hydroxyphenyl) propane
2,2-di (3 ', 5-dichlorodihydroxyphenyl) propane,
1,1-di- (4'-hydroxyphenyl) cyclohexane,
3,4'-dihydroxybenzophenone,
4,4'-dihydroxydiphenyl sulfone and
2,2-di (3 ', 5'-dimethyl-4'-hydroxyphenyl) propane
or mixtures thereof are preferred.

The proportion of fully aromatic polyesters in component A) is generally in the range from 1 to 50, preferably from 10 up to 30% by weight.

Among polyesters within the meaning of the present invention, those of PBT are different, polycarbonates should also be understood, produced by the polymerization of aromatic dihydroxy compounds, in particular bis (4-hydroxyphenyl) 2,2-propane (bisphenol A) or its derivatives, e.g. B. are available with phosgene. Appropriate Products are known per se and are described in the literature and most of them are also available in stores. The amount of poly carbonate is up to 50% by weight, preferably up to 30 % By weight, based on 100% by weight of component (A).

Of course, polyester block copolymers such as Copolyetherester can be used. Such products are on known and in the literature, e.g. B. in US-A 3,651,014, described. Corresponding products are also available in stores lich, z. B. Hytrel® (DuPont).

The polyesters from aromatic dicarboxylic acid and aliphatic diol, in particular polybutylene terephthalate, are preferably prepared in a continuous process based on DE-A 44 01 055 by

• a) in a first stage an aromatic dicarboxylic acid or their esters or ester-forming derivatives with a molar Esterified or transesterified excess of a dihydroxy compound,
• b) in a second stage that obtained according to a) Transesterification or esterification product precondensed and
• c) in a third stage the product obtainable from b) to the desired viscosity number polycondensed, whereby the Step a) and step b) of the process in at least two Performs temperature zones.

Stage a) of the process is called transesterification or Denotes esterification reaction. This is done in at least two preferably carried out at least three temperature zones. the The temperature of the following zone should be 1-40, preferably 2-30 and especially 5-10 ° C higher than the temperature of the previous gen zone. The temperature range for the entire Vereste The approximate reaction is generally 165 (depending on the input material) to 260, preferably 170 to 250 and especially 180 to 240 ° C, the pressure is generally from 1 to 10, preferably from 1 to 4 and in particular from 1 to 2 bar.

Step a) of the process is preferably carried out in such a way that are largely the same in at least two temperature zones Pressure conditions in the individual zones works. The techni prerequisites such as equipment (e.g. in the form of a boiler cascades) to create different temperature zones are known to those skilled in the art, which is why further details this is superfluous.

The starting materials such as diols and acids have already been mentioned above (Component A).

For the reaction is usually a molar excess of Diol used to achieve the desired ester equilibrium Shape. The molar ratios of dicarboxylic acid and Dicarboxylic acid ester: diol are usually 1: 1.1 to 1: 3.5 preferably 1: 1.2 to 1: 2, 2. Very particularly preferred are moles Ratios of dicarboxylic acid: diol from 1: 1.5 to 1: 2, as well Diester: diol from 1: 1.2 to 1.5.

However, it is also possible with a smaller excess of diol carry out the ester reaction in the first zone and ent corresponding to further amounts of diol in the other temperature zones admit. In the preferred embodiment of the method with three temperature zones, the total diol is divided into 3 zones as a percentage divided as follows: 60 to 85 (1), 10 to 25 (2) and 5-15 (3), preferably: 70 to 80 (1), 10 to 20 (2), 5 to 10 (3).

The residence times for the entire stage a) are 140 to 300, preferably from 150 to 260 and in particular from 160 to 220 min., The dwell time for the first zone is from 100 to 190, preferably from 110 to 150; for the second zone from 65 to 140, preferably from 65 to 110 min. For the preferred off With 3 zones, the dwell time is in the 3rd zone 15 to 45, preferably 15 to 30 minutes, the dwell time being longer decrease accordingly in the 2nd zone and as in the 1st zone as stated above.

In the preferred embodiment, the residence times decrease the ratio of the first zone to the third zone is preferably 6: 3: 1 away.

Before step a) of the process, one is particularly preferred th embodiment of the dihydroxy compound initially a catalyst Sator and then an (earth) alkali metal compound added puts.

Suitable catalysts are those already described above NEN Lewis acidic metal compounds, e.g. B. the titanium and tin Connections such as from US 39 36 421, US 43 29 444 Pa are known. Preferred compounds are Tetrabutyl orthotitanate and triisopropyl titanate and tin di-oc called toat. These are in stage a) in amounts from 65 to 100, preferably from 71 to 95 and in particular from 73 to 80 ppm (based on the metal) are used.

To further reduce the carboxyl end group content of the poly esters may be advantageous before implementing the starting monomeric 0.1 to 10 mmol, preferably 0.2 to 0.65 mmol, per kg Polyester, an alkali metal compound or alkaline earth metal compound bond (calculated as alkali metal or alkaline earth metal) added ben. Such compounds are presented in DE-A 43 33 930 beat. Preferred compounds are sodium carbonate, Sodium acetate, and sodium alcoholates, especially sodium called methanolate.

The transesterification or esterification products are then in the precondensation stage b) continuously transferred.

This has at least two, preferably at least three and in particular at least four temperature zones. The temperature the following zone is 1 to 40, preferably 2 to 30 and especially 5 to 20 W higher than the temperature of the previous gen zone. The temperature range for the entire precondensation is generally (depending on the starting materials) from 220 to 300, preferably at 225 to 290 and in particular at 240 to 290 ° C.

The precondensation is preferably carried out in such a way that in the first zone the pressure 0.5 to 1 bar, preferably 0.6 to 0.8 bar is and in the second or last zone 20 to 200, preferably wise 25 to 150 mbar and in particular 50 to 150 mbar. Technically, this z. B. a vertical tube bundle reactor can be used, other reactors are used known to the person skilled in the art.

The residence times are for the entire stage b) of the process rens from 10 to 80, preferably from 15 to 50 and especially from 20 to 40 min.

In a particularly preferred embodiment, four Temperature zones used, with the temperature from zone to zone in the proportions described above increases and the pressure of the first to the fourth zone within the limits described zen is reduced. The fourth zone is preferred in this case th embodiment of the tube bundle heat exchanger from a pre direction for the separation of vapor and liquid phase (also as br dentrenngefäß), where the ratio of the volume of the Separation vessel to the volume in the tubes preferably 5 to 15: 1, in particular 8 to 13: 1.

The volume ratios of the first three zones are designed in this particularly preferred embodiment so that the first zone from 30 to 60, preferably 50%, the second zone from 20 to 40, preferably 30% and the third zone from 10 to 30, preferably 20% proportionate to volume (volume ratios). The temperature ranges, pressure ranges and residence times for the particularly preferred embodiment of the process according to the invention are listed below:

• 1st zone: temperature from 230 to 270, preferably from 240 to 250 ° C., pressure from 0.6 to 0.9, preferably from 0.7 to 0.9 bar.
  Residence time from 10 to 30, preferably from 15 to 25 minutes.
• 2nd zone: temperature from 240 to 280, preferably from 250 to 270 ° C., pressure from 0.2 to 0.6, preferably from 0.3 to 0.5 bar.
  Residence time from 5 to 25, preferably from 7 to 15 minutes.
• 3rd zone: temperature from 245 to 290, preferably from 250 to 280 ° C., pressure from 0.1 to 0.3, preferably from 0.1 to 0.25 bar.
  Residence time from 5 to 10, preferably from 4 to 8 minutes.
• 4th zone: temperature from 250 to 300, preferably from 252 to 285 ° C., pressure from 0.015 to 0.2, preferably from 0.025 to 0.15 bar.
  Residence time from 10 to 30, preferably from 14 to 24 minutes.

Those mentioned above in step a) of the process Catalysts and other additives can be used in the above Quantities are metered into stage b) of the process.

After stage b) of the process according to the invention, the Polyester prepolymer has a viscosity number of 15 to 50, preferably have from 20 to 30 ml / g, measured as a 0.5% by weight solution in Phenol / o-dichlorobenzene (1: 1) according to DIN 53728, Part 3 (1985) 25 ° C.

The polyester prepolymer is then in stage c) of the Transferred the method according to the invention. This is preferred carried out in one stage at temperatures of 240 to 290, preferably wise from 240 to 270 and especially 240 to 265 ° C. The pressure is from 0.3 to 10, preferably 0.3 to 5 and especially 0.3 to 2 mbar.

The residence times are usually from 30 to 180, preferably from 35 to 150 min.

During the polycondensation one can preferably use an upper Carry out surface renewal of the product. Surface renewal means that constantly new polymer to the surface of the Melt arrives, so that the exit of the diol is facilitated.

This is preferably 1 to 20 and in particular 1.5 to 6 m ² / kg of product and minute.

It can still be an advantage, even at this stage of the Ver driving to add catalysts and other additives like them described above.

After the continuous polycondensation, the polyester has a viscosity number from 60 to 180, preferably from 90 to 160 ml / g, determined in a 0.5% by weight solution in one Phenol / o-dichlorobenzene mixture (weight ratio 1: 1 at 25 ° C) according to DIN 53728, 3rd part (1985).

In the case of the method described, it is advantageous if you are at Achieving at least 80%, preferably at least 95% and especially 100% of the desired final viscosity number of the poly esters lubricant and / or nucleating agent of the polymer melt admitted together, the melt optionally post-condensed and then discharges, cools and granulates. Preferably him is followed by the addition of the lubricant in an amount of 0.01 to 5, preferably 0.1 to 1 and in particular 0.2 to 0.8% by weight and / or the nucleating agent in an amount of 0.001 to 2, preferably from 0.01 to 1 and in particular from 0.03 to 0.5% by weight, based on 100% by weight of component A).

The addition is particularly preferably carried out in the form of a Suspension, the nucleating agent being added to the Melt in the lubricant, if necessary at an elevated temperature suspended. Depending on the type of lubricant used, it can to make a suspension may be required, the mixture from lubricant and nucleating agent to temperatures in advance from 30 to 150, preferably from 60 to 130 ° C and on then add to the polymer melt.

An example of this are low molecular weight polyethylene waxes called, which is known to exist in solid form at room temperature lie and for the preparation of a suspension with the nucleating medium need to be heated.

The addition of lubricants and nucleating agents is preferred wisely during the polycondensation when reaching at least 80% of the desired final viscosity number. Suitable polycondensa tion devices are known to those skilled in the art, which is why we know further details on this are superfluous. In a particularly preferred th embodiment can be the melt from the polycondensation discharge onsreaktor, via suitable devices, eg. B. Dosing pump with heating, the mixture of lubricating and nucleating add medium and the polymer melt then in z. B. a Transfer the Sulzer tube and adjust to the desired final viscosity number condense, whereby a homogenization of the melt takes place, and then discharged, cooled and granulated.

Suitable lubricants are low molecular weight polyethylene waxes, which can preferably contain functional groups such as glycidyl and / or carboxyl groups, with an average molecular weight M _n (number average) of 500 to 20,000, preferably 1,000 to 10,000, in particular 1,000 to 5,000 and very particularly 1,000 to 3,000 g / mol.

The molecular weight is usually determined by gel permeation chromatography (GPC) using an LDPE standard. The melt viscosity is preferably from 10 to 10,000, preferably from 100 to 5,000, in particular from 100 to 3,000 and very particularly from 100 to 2,000 mm ² / g (according to DIN 51 562) at a temperature of 120.degree.

In the case of the polyethylenes containing acid or epoxy groups, it can are copolymers of ethylene with α, β-unsaturated acid or Acting epoxy compounds or polyethylenes on the Acid or epoxy compounds are grafted on.

The polyethylenes can be produced by the high, medium or low pressure process. Both high density polyethylenes (HDPE) (range from 0.94 to 0.97 g / cm ³ ), preferably manufactured according to the so-called Phillips process (medium pressure process), and low density polyethylenes (LDPE) (range from 0.91 to 0.94 g / cm ³ ), in particular linear low-density polyethylenes, preferably produced by the gas phase process, can be used.

Processes for preparing such copolymers are known to those skilled in the art known (e.g. Ullmann's Encyclopedia of Technical Chemistry, 4th ed., Vol. 19, pp. 169-175).

Suitable products are commercially available under the Luwax® trademark (BASF AG), Hoechst-Wachs® PED 191 or H12 (Hoechst AG) and Poligen® EAS-1 (BASF AG) available.

Other lubricants are esters or amides or saturated or unsaturated aliphatic carboxylic acids with 10 to 40 before added 16 to 22 carbon atoms with aliphatic saturated alcohols or amines having 2 to 40, preferably 2 to 6, carbon atoms.

The carboxylic acids can be monovalent or divalent. As examples be pelargonic acid, palmitic acid, lauric acid, margaric acid, Dodecanedioic acid, behenic acid and particularly preferably stearic acid, Capric acid and montanic acid (mixture of fatty acids with 30 to 40 carbon atoms).

The aliphatic alcohols can be 1- to 4-valent, where not all OH groups have to be esterified. Examples of alcohol holes are n-butanol, n-octanol, stearyl alcohol, ethylene glycol, Propylene glycol, neopentyl glycol, pentaerythritol, with glycerin and pentaerythritol are preferred.

The aliphatic amines can be 1- to 3-valent. Examples these are stearylamine, ethylenediamine, propylenediamine, hexa methylenediamine, di (6-aminohexyl) amine, with ethylenediamine and Hexamethylenediamine are particularly preferred. Preferred esters or amides are correspondingly glycerol distearate, ethylenediaminedi stearate, glycerin monopalmitate, glycerin trilaurate, glycerin monobe henate and pentaerythritol tetrastearate.

Mixtures of different esters or amides or Esters with amides can be used in combination, with the Mi ratio is arbitrary.

Particularly preferred compositions
contain
30 to 98.99 wt% A)
1 to 40% by weight fillers D)
0.01 to 5% by weight of esters or amides E) as described above.

Minerals are particularly suitable as nucleating agents the group of alkali and / or alkaline earth (alumo) silicates before belongs to the group of island silicates or layered silicates.

All possible compounds such as hydroxides, carbonates, Hydroxycarbonates, sulfates, silicates as well as phosphates and Phosphonates can be used.

In particular, magnesium silicates are in different Wed Mixing ratios suitable, with talc is preferred.

Typical compositions of talc can usually be determined by elemental analysis and contain as essential components SiO ₂ , MgO, Al ₂ O ₃ , Fe ₂ O ₃ , CaO (after burning).

A particularly preferred nucleating agent is talc, which preferably has a particle size (d ₉₀ value) of less than 150 μm, preferably less than 100 μm and in particular less than 50 μm.

Other suitable nucleating agents are alkali or earth alkali salts of organic or inorganic acids called such as for example sodium antimonate, calcium stearate, sodium tereph thalate, calcium citrate and metallic acids (basic acids) des Titans or Wolframs.

Suitable derivatives of inorganic acids are preferred Phosphoric acid derivatives, being sodium phenylphosphinate, zinc phosphate, calcium (up to -3,5-di-tert-butylethylphosphonate (Irganox® 1425 from Ciba Geigy AG) and Tetrakis (2,4-di-tert-butylphe nyl) -4,4'-biphenylenediphosphonite) are particularly preferred.

The molding compositions according to the invention can be used as component B) 40, preferably up to 30% by weight of rubber-elastic polymers sate (often also as an impact modifier, elastomers or rubbers labeled) included.

Quite generally, these are copolymers which are preferably composed of at least two of the following monomers:
Ethylene, propylene, butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene, acrylonitrile and acrylic or methacrylic acid esters with 1 to 18 carbon atoms in the alcohol component.

Such polymers are z. B. in Houben-Weyl, methods of the orga nischen Chemie, Vol. 14/1 (Georg-Thieme-Verlag, Stuttgart, 1961). Pages 392 to 406 and in the monograph by C. B. Bucknall, "Toughened Plastics" (Applied Science Publishers, London, 1977) described.

The following are some preferred types of such elastomers presented.

Preferred types of such elastomers are the so-called ethylene Propylene (EPM) or ethylene-propylene-diene (EPDM) rubbers.

EPM rubbers generally have practically no double bonds more, while EPDM rubbers have 1 to 20 double bonds / 100 C- May have atoms.

As diene monomers for EPDM rubbers, for example, conju gated dienes such as isoprene and butadiene, non-conjugated dienes with 5 to 25 carbon atoms such as penta-1,4-diene, hexa-1,4-diene, Hexa-1,5-diene, 2,5-dimethylhexa-1,5-diene and OCta-1,4-diene, cy clic dienes such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadiene and alkenyl norbornenes such as 5-ethylidene-2-norbornene, 5-butylidene-2-norbornene, 2-meth allyl-5-norbornene, 2-isopropenyl-5-norbornene and tricyclodienes such as 3-methyl-tricyclo (5.2.1.0.2.6) -3,8-decadiene or their Called mixtures. Hexa-1,5-diene, 5-ethylidene are preferred norbornene and dicyclopentadiene. The diene content of the EPDM chew Tschuke is preferably 0.5 to 50, in particular 1 to 8% by weight, based on the total weight of the rubber.

EPM or EPDM rubbers can preferably also be reactive with Be grafted carboxylic acids or their derivatives. Here are z. B. 1 acrylic acid, methacrylic acid and their derivatives, e.g. B. Glycidyl (meth) acrylate, as well as maleic anhydride.

Another group of preferred rubbers are copolymers of ethylene with acrylic acid and / or methacrylic acid and / or the esters of these acids. In addition, the rubbers can also dicarboxylic acids such as maleic acid and fumaric acid or derivatives of these acids, z. B. contain esters and anhydrides, and / or epoxy groups ent containing monomers. These dicarboxylic acid derivatives or monomers containing epoxy groups are preferably incorporated into the rubber by adding dicarboxylic acid or epoxy group-containing monomers of the general formulas II or III or IV or V to the monomer mixture

where R ¹ to R ^{9 represent} hydrogen or alkyl groups with 1 to 6 carbon atoms and m is an integer from 0 to 20, g is an integer from 0 to 10 and p is an integer from 0 to 5.

The radicals R ¹ to R ^{9 are} preferably hydrogen, m being 0 or 1 and g being 1. The corresponding compounds are maleic acid, fumaric acid, maleic anhydride, allyl glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formulas II, III and V are maleic acid, maleic anhydride and epoxy group-containing esters of the Acrylic acid and / or methacrylic acid, such as glycidyl acrylate, Glycidyl methacrylate and the esters with tertiary alcohols, such as t- Butyl acrylate. The latter do not have any free carboxyl groups on, but come close in their behavior to the free acids and are therefore referred to as monomers with latent carboxyl groups net.

The copolymers advantageously consist of 50 to 98% by weight Ethylene, 0.1 to 20% by weight of epoxy group-containing monomers and / or methacrylic acid and / or acid anhydride groups ent holding monomers and the remaining amount of (meth) acrylic acid esters.

Copolymers made from are particularly preferred
50 to 98, in particular 55 to 95 wt .-% ethylene,
0.1 to 40, in particular 0.3 to 20% by weight of glycidyl acrylate and / or glycidyl methacrylate, (meth) acrylic acid and / or maleic anhydride, and
1 to 45, in particular 10 to 40% by weight of n-butyl acrylate and / or 2-ethylhexyl acrylate.

Further preferred esters of acrylic and / or methacrylic acid are the methyl, ethyl, propyl and i- or t-butyl esters.

In addition, vinyl esters and vinyl ethers can also be used as comonomers be set.

The ethylene copolymers described above can according to known processes are produced, preferably by random copolymerization under high pressure and elevated Temperature. Corresponding processes are generally known. Preferred elastomers are also emulsion polymers whose Her position z. B. Blackley in the monograph "Emulsion Polymerization ". The emulsifiers that can be used and catalysts are known per se.

In principle, homogeneously structured elastomers or sol surface can be used with a shell structure. The shell-like The structure is determined by the order in which the individual monomers are added certainly; the morphology of the polymers is also influenced by this Order of addition influenced.

The monomers for the production are only representative here of the rubber part of the elastomers acrylates such. B. n-butyl acryl lat and 2-ethylhexyl acrylate, corresponding methacrylates, butadiene and isoprene and mixtures thereof. These monomers can NEN with other monomers such. B. styrene, acrylonitrile, vinyl ethers and other acrylates or methacrylates such as methyl meth acrylate, methyl acrylate, ethyl acrylate and propyl acrylate copoly be merized.

The soft or rubber phase (with a glass transition temperature below 0 ° C) the elastomers can be the core, the outer shell or a middle shell (for elastomers with more than two shell structure); in the case of multi-shell elastomers, Several shells can also consist of one rubber phase.

In addition to the rubber phase, there are also one or more hard ones components (with glass transition temperatures of more than 20 ° C) am Structure of the elastomer involved, so these are generally through polymerization of styrene, acrylonitrile, methacrylonitrile, α-methylstyrene, p-methylstyrene, acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate and methyl methacrylate produced as the main monomers. In addition, you can also curdle here more proportions of other comonomers are used.

In some cases it has been found to be advantageous to use emulsion polymers which have reactive groups on the surface. Such groups are e.g. B. epoxy, carboxyl, latent carboxyl, amino or amide groups and functional groups that are created by using monomers of the general formula

can be introduced,
where the substituents can have the following meanings:
R ^{10 is} hydrogen or a C ₁ - to C ₄ -alkyl group,
R ^{11 is} hydrogen, a C ₁ - to C ₈ -alkyl group or an aryl group, in particular phenyl,
R ^{12 is} hydrogen, a C ₁ - to C ₁₀ -alkyl, a C ₆ - to C ₁₂ -aryl group or -OR ¹³
R ^{13 is} a C ₁ - to C ₈ -alkyl or C ₆ - to C ₁₂ -aryl group, which may optionally be substituted with O- or N-containing groups,
X is a chemical bond, a C ₁ - to C ₁₀ -alkylene or C ₆ -C ₁₂ -arylene group or

Y OZ or NH-Z and
Z is a C ₁ to C ₁₀ alkylene or C ₆ to C ₁₂ arylene group.

The graft monomers described in EP-A 208 187 are also suitable for introducing reactive groups on the surface.

Further examples are acrylamide, methacrylamide and substituted esters of acrylic acid or methacrylic acid such as (N-t- Butylamino) ethyl methacrylate, (N, N-dimethylamino) ethyl acrylate, (N, N-dimethylamino) methyl acrylate and (N, N-diethylamino) ethyl called acrylate.

Furthermore, the particles of the rubber phase can also be crosslinked be. Monomers acting as crosslinkers are, for example Buta-1,3-diene, divinylbenzene, diallyl phthalate and dihydrodicyclo pentadienyl acrylate and those described in EP-A 50,265 Links.

Furthermore, so-called graft-crosslinking monomers (graft linking monomers) can be used, d. H. Monomers with two or more polymerizable double bonds that occur in the polymer react at different speeds.

Preferably, those compounds are used in which min at least one reactive group with about the same speed polymerizes like the other monomers, while the other reacts tive group (or reactive groups) e.g. B. significantly slower polymerized (polymerize). The different Polymerisa tion speeds add a certain amount unsaturated double bonds in rubber. Will on closing a further phase on such a rubber grafts, the double bonds present in the rubber react gene at least partially with the graft monomers with training of chemical bonds, d. H. the grafted phase is at least at least partially through chemical bonds with the graft base connected.

Examples of such graft-linking monomers are allyl groups containing monomers, especially allyl esters of ethylenic unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, Diallyl maleate, diallyl fumarate, diallyl itaconate or the corresponding corresponding monoallyl compounds of these dicarboxylic acids. Besides there there are a large number of other suitable graft-linking monomers rer; for more details, see, for example, the See U.S. Patent 4,148,846.

In general, the proportion of these crosslinking monomers is up to 5% by weight of the impact-modifying polymer, preferably not more than 3% by weight, based on the impact strength modifying polymers.

Some preferred emulsion polymers are listed below. First of all, graft polymers with a core and at least one outer shell that have the following structure should be mentioned here:

These graft polymers, especially ABS and / or ASA polymers in amounts of up to 40% by weight, are preferably used for impact resistance modification of PBT, possibly mixed with up to 40 wt .-% polyethylene terephthalate used. Appropriate Blend products are available under the trademark Ultradur®S (formerly Ultrablend®S from BASF AG) available. ABS / ASA mixtures with Polycarbonates are under the trademark Terblend® (BASF AG) im Commercially available.

Instead of graft polymers with a multi-shell structure can also be homogeneous, i.e. H. single-shell elastomers 1,3-butadiene, isoprene and n-butyl acrylate or their copolymers can be used. These products can also be used by using of crosslinking monomers or monomers with reactive groups getting produced.

Examples of preferred emulsion polymers are n-butyl acryl lat / (meth) acrylic acid copolymers, n-butyl acrylate / glycidyl acrylate or n-butyl acrylate / glycidyl methacrylate copolymers, graft polymers with an inner core made of n-butyl acrylate or on Butadiene base and an outer shell of those mentioned above th copolymers and copolymers of ethylene with comonomers, the provide reactive groups.

The elastomers described can also be used according to other customary Procedure, e.g. B. by suspension polymerization, who produced the.

Silicone rubbers, as in DE-A 37 25 576, EP-A 235 690, DE-A 38 00 603 and EP-A 319 290 described are flat if preferred.

Mixtures of the above can of course also be used led rubber types are used.

The molding compositions according to the invention can be used as component C) from 0 to 30 and preferably 0 to 20 wt .-% of a flame retardant or contain a combination of flame retardants, which are different of D) and E) are.

Examples of flame retardants are halogen-containing Connections, as in the Kunststoff-Handbuch 3 / l, Ed. G. W. Becker, D. Braun, Hanser-Verlag, 1992, Munich, pages 31 to 35 be wrote, or those based on nitrogen or organic chemical or inorganic phosphorus compounds, for example tri phenylphosphine oxide, suitable.

Furthermore, the molding compositions according to the invention can be fibrous or particulate fillers (component D)) contain which ver different from B), C) and / or E).

As fibrous or particulate fillers such. B. Coals fabric fibers, glass fibers, glass spheres, amorphous silica, asbestos, Calcium silicate, calcium metasilicate, magnesium carbonate, kaolin, Chalk, powdered quartz, mica, barium sulfate and feldspar ge called, which in amounts up to 50 wt .-%, in particular 1 to 40%, in particular 20 to 35% by weight can be used.

Preferred fibrous fillers are carbon fibers, Aramid fibers and potassium titanate fibers called, being glass fibers are particularly preferred as E-glass. These can be called rovings or cut glass can be used in the commercially available forms.

The fibrous fillers can be used for better compatibility with the thermoplastic with a silane compound superficially be pretreated.

Suitable silane compounds are those of the general formula

(X- (CH ₂ ) _n ) _k -Si- (OC _m H _{2m + 1} ) _2-k

in which the substituents have the following meaning:

n is an integer from 2 to 10, preferably 3 to 4
m is an integer from 1 to 5, preferably 1 to 2
k is an integer from 1 to 3, preferably 1

Preferred silane compounds are aminopropyltrimethoxysilane, Aminobutyltrimethoxysilane, aminopropyltriethoxysilane, aminobutyl triethoxysilane and the corresponding silanes, which as Substituent X contain a glycidyl group.

The silane compounds are generally used in amounts of 0.05 up to 5, preferably 0.5 to 1.5 and in particular 0.8 to 1% by weight (based on D) used for surface coating.

Needle-shaped mineral fillers are also suitable.

Needle-shaped mineral fillers are used in the sense of Invention of a mineral filler with a pronounced na Understood delicately shaped character. As an example, let it be needle-shaped Called wollastonite. Preferably the mineral has one L / D (length diameter) ratio from 8: 1 to 35: 1 before from 8: 1 to 11: 1. The mineral filler can optionally with the abovementioned silane compounds be pretreated; however, the pretreatment is not essential necessary.

Other fillers are kaolin, calcined kaolin, Called wollastonite, talc and chalk.

Component E) which can be used according to the invention 1 thermoplastic molding compounds further additives and processing processing auxiliaries such as stabilizers, oxidation retarders, agents against thermal decomposition and decomposition by ultraviolet light, Lubricants and mold release agents, colorants such as dyes and pig ments, powdery fillers and reinforcing agents, nucleation contain agents, plasticizers, etc., the proportion of which is usually not more than 20% by weight, preferably not more than 10% by weight, be and which are different from B), C) and / or D).

As examples of oxidation retarders and heat stabilizers are sterically hindered phenols, hydroquinones, aromatic se secondary amines such as diphenylamines, various substituted ver Enter these groups and their mixtures in concentrations up to at 1% by weight, based on the weight of the thermoplastic mold called masses.

As UV stabilizers, which are generally used in amounts up to 2 wt .-%, based on the molding composition, are used, ver various substituted resorcinols, salicylates, benzotriazoles and Called benzophenones.

Furthermore, organic dyes such as nigrosine, pigments such as Titanium dioxide, cadmium sulfide, cadmium selenide, phthalocyanines, Ultramarine blue and carbon black are added as dyes, as well powdered fillers and reinforcing agents. examples for the latter are minerals, amorphous silica, asbestos, calcium silicate (wollastonite), aluminum silicate, magnesium carbonate, kao lin, chalk, powdered quartz, mica and feldspar. The amount such fillers and dyes is generally up to 20% by weight, preferably up to 10% by weight and in particular up to 5% by weight.

Sodium phenylphosphinate, aluminum oxide, silicon dioxide, nylon 22 and preferably talc are used will.

Lubricants and mold release agents, which are usually used in amounts of up to are used to 1 wt .-%, are preferably long-chain fats acids (e.g. stearic acid or behenic acid), their salts (e.g. Ca or Zn stearate) or ester derivatives, as described above for Kom component A) (e.g. stearyl stearate or pentaerythritol tetrastearate) and amide derivatives (e.g. ethylene-bis-stearylamide), which are preferably used as a mixture with 1,6-hexanediol the.

Examples of plasticizers are dioctyl phthalate, Dibenzyl phthalate, butylbenzyl phthalate, carbon hydrogen oils, N- (n-butyl) benzenesulfonamide and o- and p-tolyls called thylsulfonamide.

The molding compositions according to the invention can also contain 0 to 2% by weight contain fluorine-containing ethylene polymers. This is what it is are polymers of ethylene with a fluorine content of 55 to 76% by weight, preferably 70 to 76% by weight.

Examples of these are polytetrafluoroethylene (PTFE), tetrafluores ethylene-hexafluoroethylene copolymers or tetrafluoroethylene copoly merizates with smaller proportions (usually up to 50% by weight) copolymerizable ethylenically unsaturated monomers. These are z. B. von Schildknecht in "Vinyl and Related Polymers", Wi ley-Verlag, 1952, pages 484 to 494 and by Wall in "Fluorpoly mers "(Wiley Interscience, 1972).

These fluorine-containing ethylene polymers are homogeneously distributed in the molding compositions and preferably have a particle size d ₅₀ (numerical average) in the range from 0.05 to 10 μm, in particular from 0.1 to 5 μm. These small particle sizes can be achieved particularly preferably by using aqueous dispersions of fluorine-containing ethylene polymers and incorporating them into a polyester melt.

The thermoplastic molding compositions according to the invention can be used according to known processes can be produced in which the Starting components in conventional mixing devices such as screws extruders, Brabender mills or Banbury mills mix and match finally extruded. After the extrusion, the extrudate can be removed cooled and crushed. It can also be individual components are premixed and then the remaining raw materials individually and / or can also be added mixed. The mixed temperatures are usually between 230 and 290 ° C.

The molding compositions according to the invention are distinguished by good mechanical properties niche properties, especially through an excellent one Elongation at break. Yellowing effects occur with the molding compositions according to the invention even after prolonged intensive use clearing or in the case of heat storage either not at all or only to a small extent. Molecular degradation reactions of the polymer armaments, which regularly translate into a change in the Find the viscosity number are also only subordinate to be watch out. The molding compositions according to the invention also show a wall-free surface behavior, as well as an improved Processability (shorter cycle times) and can be used to manufacture development of fibers, foils and moldings, especially for applications applications in the electrical and electronics sector. These applications are in particular lamp parts such as lamp sockets genes and brackets, plugs and connector strips, bobbins, Housing for capacitors or contactors as well as fuses switches, relay housings and reflectors.

The present invention will be explained in more detail by way of examples explained.

Examples General test procedure (components a ₁₁ and a ₁₂ )

In a continuous manner, 881.8 g (dimethyl terephthalate) DMT and 563.7 g 1,4-butanediol (BDO) were fed to a reaction zone. The butanediol was continuously mixed with tetrabutyl orthotitanate (TBOT) and 99 micro liters of a 30% by weight solution of NaOCH ₃ in methanol before contacting the DMT.

The temperature in the first reaction zone was 185 ° C at one Pressure of 1 bar and an average residence time of 182 min.

The temperature in the second reaction zone was 205 ° C at one Pressure of 1 bar and an average residence time of 63 min.

The temperature in the third reaction zone was 210 ° C at one Pressure of 1 bar and an average residence time of 40 min.

The resulting distillates, which BDO, DMT, THF and what ser contained were separated in a column system, wherein DMT and BDO were returned to the reaction. With a Conversion of 93%, the transesterification product was a vertical ste The existing pipe was fed, which was divided into four heating zones.

The temperature in the fourth reaction zone was 247 ° C at one Pressure of 700 mbar and an average residence time of 22 min.

The temperature in the fifth reaction zone was 252 ° C for one Pressure of 400 mbar and an average residence time of 11 minutes.

The temperature in the sixth reaction zone was 255 ° C a pressure of 150 mbar and an average residence time of 5 min.

The temperature in the seventh reaction zone was 256 ° C at one Pressure of 30 mbar and an average residence time of 18 min.

The excess BDO and the reaction products like THF and What water were separated at the top of the reaction tube. That Precondensate was in a without further addition of catalysts Polycondensation reactor (zone 8) transferred.

The temperature in the eighth reaction zone was 257 ° C. at a pressure of 0.4 mbar, an average residence time of 115 minutes and a surface ^{renewal of 4 m 2} / h. Kg of PBT.

According to the above manufacturing method, the following were produced:

Component a ₁₁ ) PBT with a viscosity number (VZ) of 130 ml / g and a titanium content of 75 ppm (calculated as metal) Component a ₁₂ ) PBT with a VZ of 130 ml / g and a titanium content of 110 ppm (calculated based on metal) Component a ₂ ) PET with a VZ of 67 ml / g. Component a ₃ ) Polycarbonate with a VZ of 59 ml / g (in CH ₂ Cl ₂ )

The viscosity number was measured at 25 ° C. on a 0.5% solution of the poly mers measured in a 1: 1 mixture of phenol / o-dichlorobenzene.

Component D) Chopped glass fiber with a thickness of 10 µm (epoxysilanized size) Component E) Pentaerythritol tetrastearate

Components A) to E) were mixed on a twin-screw extruder at 25,000 to 26,000 and extruded into a water bath. After granulation and drying, the following measurements were carried out:
The crystallization was measured by means of DSC after melting once up to 25,000 at a cooling rate of 20 ° C./min. The half-value width (HWB) was determined as the width of the crystallization peak (in ° C) measured halfway between the baseline and the peak maximum.

T (KB) represents the temperature value in ° C at which during cooling len the crystallization begins and T (KM) the degree of crystallization ximum of the cooling curve.

The heat distortion temperature B (HDT) was measured according to ISO 75 sen.

The compositions of the molding compounds and the results of Measurements can be found in Tables 1 and 2.

Table 1

Table 2

Components a ₁₁ - a ₃ were mixed in a kneader at 250 ° C. and a sample was taken after 10, 20 and 30 min kneading times.

Claims (8)

1. Thermoplastic polyester molding compositions containing

• A) 30 to 100% by weight of polyesters, composed of
  • 1. 50 to 99 wt .-% of polybutylene terephthalate with a content of a Lewis acidic inorganic or orga African metal compound in the range of 65 to 100 ppm (based on the metal), and
  • 2. 1 to 50% by weight of polyesters other than polybutylene terephthalate,
• B) 0 to 40% by weight of rubber-elastic polymers,
• C) 0 to 30% by weight of flame retardants,
• D) 0 to 50% by weight of fillers and
• E) 0 to 20% by weight of other additives,

where the sum of the percentages by weight of components A) always results in 100. 2. Thermoplastic polyester molding compositions according to claim 1, characterized characterized in that polybutylene terephthalate with a Viscosity number in the range from 80 to 180 ml / g, determined ge according to ISO 1628. 3. Thermoplastic polyester molding compositions according to Claims 1 or 2, characterized in that one polybutylene terephthalate with a content of organic or inorganic between titanium or tin compounds in the range from 71 to 95 ppm (based on the metal) used. 4. Thermoplastic polyester molding compositions according to Claims 1 to 3, characterized in that polyethylene terephthalate or polycarbonate is used _{as component a 2).} 5. Thermoplastic polyester molding compositions according to Claims 1 to 4, containing 1 to 40% by weight of component D). 6. Thermoplastic polyester molding compositions according to Claims 1 to 5, containing 0.01 to 5 wt .-% lubricant E) aus selects from the group of esters or amides saturated or unsaturated aliphatic carboxylic acids with 10 to 40 carbon atoms Men with aliphatic saturated alcohols or amines with 2 up to 40 carbon atoms. 7. Use of the thermoplastic polyester molding compositions according to claims 1 to 6 for the production of fibers, films or moldings. 8. Fibers, foils and moldings, obtainable from the thermo Plastic polyester molding compositions according to Claims 1 to 6.