EP1812514A1

EP1812514A1 - Polymer blends consisting of polyesters and linear oligomer polycarbonates

Info

Publication number: EP1812514A1
Application number: EP05802530A
Authority: EP
Inventors: Andreas Eipper; Bernd Bruchmann; Carsten Weiss; Jean-François STUMBE
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2004-11-11
Filing date: 2005-11-05
Publication date: 2007-08-01
Also published as: WO2006050872A1; US20090062412A1; KR20070085915A; JP2008519874A; DE102004054632A1; CN101056940A

Abstract

The invention relates to a polymer blend containing the following constituents A) to C), the sum of said constituents amounting to 100 wt. %: A) between 30 and 99.99 wt. % of at least one polyester, B) between 0.01 and 70 wt. % of at least one linear oligomer polycarbonate, and C) between 0 and 80 wt. % of other additives.

Description

Polymer blends of polyesters and linear oligomeric polycarbonates

description

The invention relates to a polymer blend comprising the components A) to C), de¬ ren sum 100 wt .-% results,

A) from 30 to 99.99% by weight of at least one polyester A),

B) 0.01 to 70 wt .-% of at least one linear, oligomeric polycarbonate B), and

C) 0 to 80 wt .-% of further additives C).

Moreover, the invention relates to the use of the polymer blends for the production of moldings, films, fibers and foams, as well as the obtainable from the polymer blend moldings, films, fibers and foams. Finally, the invention relates to the use of linear, oligomeric polycarbonates as defined as Komponen¬ te B), to increase the flowability of polyesters.

Polyesters such as polybutylene terephthalate (PBT) or polyethylene terephthalate (PET), due to their balanced mechanical properties, high chemical resistance, good heat resistance and good dimensional stability, have a wide range of applications, e.g. as technical parts in motor vehicles, electrical and electronic devices, in precision engineering and in mechanical engineering. PET is also used for bottles, bowls, cups and other packaging. Such moldings are usually produced by injection molding and often in large quantities. To shorten the injection molding cycle time, high flowability of the polymer is desired. It is usually achieved by adding lubricants, mineral oils (white oil) or polymers with low molecular weight or oligomers. However, the mechanical properties, the heat resistance (Vicat) and the Dimen¬ sion stability worsened by these flow improvers clearly.

Polymer blends of polyesters and conventional polycarbonates are known, see for example EP-A 846 729, DE-A 3004942 and DE-A 2343609. The polycarbonates used in these blends are prepared, for example, from biphenyl carbonate and bisphenol A or an¬ their aromatic dihydroxy compounds, and have As a rule, a relative viscosity η _{re \} from 1.1 to 1.5, in particular 1.28 to 1.4 (measured at 25 ° C in a 0.5 wt .-% solution in dichloromethane). This corresponds to a weight-average molecular weight of the polycarbonate of 10,000 to 200,000 g / mol, or viscous COS numbers from 20 to 100 ml / g, measured according to DIN 53727 in said solution at 23 ⁰ C. These polycarbonates are therefore high molecular weight.

It was the task to remedy the disadvantages described. In particular, alternative polymer mixtures (blends) based on polyesters such as PBT or PET should be provided, which are distinguished by a good flowability. The flow improver should be easy to prepare.

The good flowability should be achieved while maintaining the good mechanical and thermal properties of the polyester. In particular, the mechanics (for example modulus of elasticity, breaking and elongation at break, breaking stress and impact strength) and the dimensional stability should be at a similar level as in the case of polyesters without flow improvers.

Accordingly, the polymer blends defined at the outset, their use as mentioned, and the moldings, films, fibers and foams from the polymer blends, were found. In addition, the use of linear oligomeric polycarbonates B) has been found to increase the flowability of polyesters. Preferred embodiments of the invention can be found in the subclaims.

The polymer blend contains

A) from 30 to 99.99, preferably from 50 to 99.9, in particular from 70 to 99.7, and particularly preferably from 90 to 99.5,% by weight of the polyester A),

B) 0.01 to 70, preferably 0.1 to 50, in particular 0.3 to 30 and particularly preferably 0.5 to 10 wt .-% of the linear oligomeric polycarbonate B), and

C) 0 to 80, preferably 0 to 50 and particularly preferably 0 to 40 wt.% Of additional substances C),

wherein the amounts within the above ranges are selected such that the sum of the components A) to C) complements 100 wt .-%. Component C) is optional.

Polyester A)

As component A), all polyesters known to those skilled in the art are suitable. Preference is given to aromatic (partially and wholly aromatic) polyesters. In general, polyesters A) based on aromatic dicarboxylic acids and an aliphatic or aromatic dihydroxy compound are used. A first group of preferred polyesters are polyalkylene terephthalates, in particular those having 2 to 10 carbon atoms in the alcohol part. Such polyalkylene terephthalates are known per se and described in the literature. They contain an aromatic ring in the main chain derived from the aromatic dicarboxylic acid. The aromatic ring may also be substituted, for example by halogen, such as chlorine and bromine, or by C 1 -C ₄ -alkyl groups, such as methyl, ethyl, i- or n-propyl and n, i and t-butyl, respectively. groups.

These polyalkylene terephthalates can be prepared by reacting aromatic dicarboxylic acids, their esters or other ester-forming derivatives with aliphatic dihydroxy compounds in a manner known per se.

Preferred dicarboxylic acids are 2,6-naphthalenedicarboxylic acid, terephthalic acid and isophthalic acid or mixtures thereof. Up to 30 mol%, preferably not more than 10 mol% of the aromatic dicarboxylic acids can be replaced by aliphatic or cycloaliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acids and cyclohexanedicarboxylic acids.

Of the aliphatic dihydroxy compounds are diols having 2 to 6 carbon atoms, in particular 1, 2-ethanediol, 1,3-propanediol, 1, 4-butanediol, 1, 6-hexanediol, 1,4-hexanediol, 1, 4-cyclohexanediol , 1, 4-cyclohexanedimethanol and neopentyl glycol or mixtures thereof.

Particularly preferred polyesters A) are polyalkylene terephthalates which are derived from alkanediols having 2 to 6 C atoms. Of these, particularly preferred are polyethylene terephthalate (PET), polypropylene terephthalate and polybutylene terephthalate (PBT) or mixtures thereof. Particularly preferred are PET and PBT.

Preference is furthermore given to PET and / or PBT which contain up to 1% by weight, preferably up to 0.75% by weight, of 1,6-hexanediol and / or 2-methyl-1,5-pentanediol as further monomer units contain.

The viscosity number of the polyesters A) is generally in the range from 50 to 220, preferably from 80 to 160 (measured in a 0.5% strength by weight solution in a phenol / o-dichlorobenzene mixture (weight ratio 1: 1 ) at 25 ⁰ C according to ISO 1628.

Particular preference is given to polyesters whose carboxyl end group content is up to 100 meq / kg, preferably up to 50 meq / kg and in particular up to 40 meq / kg of polyester. Such polyesters can be prepared, for example, by the process of DE-A 44 01 055. The carboxyl end group content is usually determined by titration methods (eg potentiometry). Particularly preferred molding compositions contain as component A) a mixture of polyesters which are different from PBT, such as, for example, polyethylene terephthalate (PET). The proportion of, for example, the polyethylene terephthalate is preferably in the mixture up to 50, in particular 10 to 35 wt .-%, based on 100 wt .-% A).

Furthermore, it is advantageous to use PET recyclates (also termed scrap PET), optionally mixed with polyalkylene terephthalates such as PBT.

Recyclates are generally understood as:

1) so-called Post Industrial Recyclate: these are production waste in polycondensation or in processing, e.g. Sprues in the injection molding process, start-up goods in the injection molding or extrusion or edge sections of extruded sheets or foils,

2) Post Consumer Recyclate: These are plastic items that are collected and processed after use by the end user. By far the dominating items in terms of volume are blow-molded PET bottles for mineral water, soft drinks and juices.

Both types of recycled material can be present either as regrind or in the form of granules. In the latter case, after the separation and purification, the tube cyclates are melted in an extruder and granulated. This usually facilitates the handling, the flowability and the metering for further processing steps.

Both granulated and regrind recyclates can be used, with the maximum edge length being 10 mm, preferably less than 8 mm. Due to the hydrolytic cleavage of polyesters during processing (due to traces of moisture) it is advisable to pre-dry the recyclate. The residual moisture content after drying is preferably <0.2%, in particular <0.05%.

Other groups which may be mentioned are fully aromatic polyesters which are derived from aromatic dicarboxylic acids and aromatic dihydroxy compounds. Suitable aromatic dicarboxylic acids are the compounds already described for the polyalkylene terephthalates. Mixtures are preferably from 5 to 100 mol% isophthalic acid and 0 to 95 mol% hthalsäure Terep ^', in particular mixtures of about 80% terephthalic acid with isophthalic acid 20% to about equivalent mixtures of these two acids. The aromatic dihydroxy compounds preferably have the general formula

in which Z represents an alkylene or cycloalkylene group having up to 8 C atoms, an arylene group having up to 12 C atoms, a carbonyl group, a sulfonyl group, an oxygen or sulfur atom or a chemical bond and in the m the value 0 to 2 has. The compounds may also carry C _r C ₆ alkyl or alkoxy groups and fluorine, chlorine or bromine as substituents on the phenylene groups.

As a parent of these compounds his example

dihydroxydiphenyl,

Di (hydroxyphenyl) alkane,

Di (hydroxyphenyl) cycloalkane,

Di (hydroxyphenyl) sulfide, di (hydroxyphenyl) ether,

Di- (hydroxyphenyl) ketone, di- (hydroxyphenyl) sulfoxide, σ, σ'-di- (hydroxyphenyl) -dialkylbenzene,

Di- (hydroxyphenyl) sulfone, di (hydroxybenzoyl) benzene resorcinol and

Hydroquinone and their kemalkylierte or nucleated derivatives called.

Of these will be

4,4'-dihydroxydiphenyl,

2,4-di- (4'-hydroxyphenyl) -2-methylbutane σ, or'-di- (4-hydroxyphenyl) -p-diisopropylbenzene,

2,2-di- (3'-methyl-4'-hydroxyphenyl) propane and

2,2-di- (3'-chloro-4'-hydroxyphenyl) propane,

and 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'-dihydroxydiphenylsulfone and 2,2-di (3 ', 5'-dimethyl-4'-hydroxyphenyl) propane or mixtures thereof are preferred.

Of course, it is also possible to use mixtures of polyalkylene terephthalates and wholly aromatic polyesters. These generally contain from 20 to 98% by weight of the polyalkylene terephthalate and from 2 to 80% by weight of the wholly aromatic polyester.

Of course, it is also possible to use polyester block copolymers, such as copolyether esters. Such products are known per se and are known in the literature, e.g. in US Pat. No. 3,651,014. Commercially available products are also available, e.g. Hytrel® (DuPont).

The polyester A) can also be used as prepolymer A '), which is postcondensed after mixing with the components B) and optionally C), see below.

According to the invention, polyesters A) are also to be understood to mean halogen-free polycarbonates. Suitable halogen-free polycarbonates are, for example, those based on diphenols of the general formula

wherein Q is a single bond, a G ₁ - to C ₈ -alkylene, C ₂ - to C ₃ -alkylidene, C ₃ - to C ₆ cycloalkylidene group, a C ₆ - to C ₂ arylene group and -O- , -S- or -SO ₂ - and m is an integer from 0 to 2.

Halogen-free polycarbonates in the context of the present invention means that the polycarbonates are composed of halogen-free diphenols, halogen-free chain terminators and optionally halogen-free branching agents, the content of subordinate ppm amounts of saponifiable chlorine resulting, for example, from the preparation of the polycarbonates with phosgene Phase interface method, not to be regarded as halogen-containing in the context of the invention. Such polycarbonates with ppm contents of saponifiable chlorine are halogen-free polycarbonates in the context of the present invention.

The diphenols may also have substituents on the phenylene radicals, such as C ₁ - to C ₆ -alkyl or C ₁ - to C ₆ -alkoxy. Preferred diphenols of the above formula are, for example, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1, 1-bis (4-hydroxyphenyl) cyclohexane. Particularly preferred are 2,2-bis (4-hydroxyphenyl) propane and 1, 1-bis (4- hydroxyphenyl) cyclohexane, and 1, 1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclo- hexane.

Both homopolycarbonates and copolycarbonates are suitable as polyester A), in addition to the bisphenol A homopolymer, the copolycarbonates of bisphenol A are preferred.

The polycarbonates suitable as component A) may be branched in a known manner, preferably by incorporation of from 0.05 to 2.0 mol%, based on the sum of the diphenols used, of at least trifunctional compounds , For example, those having three or more than three phenolic OH groups.

Particularly suitable have proved Poiycarbonate relative viscosities / 7 i _re of 1, 10 to 1.50, in particular from 1.25 to 1, having the 40th This corresponds to average molecular weights M _w (weight average) of from 10,000 to 200,000, preferably from 20,000 to 80,000 g / mol.

The diphenols of the above general formula are known per se or can be prepared by known processes. The polycarbonates can be prepared, for example, by reacting the diphenols with phosgene by the phase boundary process or with phosgene by the homogeneous phase process (the so-called pyridine process), the molecular weight to be set in each case being achieved in a known manner by a corresponding amount of known chain terminators , (With respect polydiorganosiloxanhaltigen polycarbonates see, for example, DE-OS 33 34 782).

Suitable chain terminators include phenol, pt-butylphenol but also long-chain alkylphenols such as 4- (1, 3-tetramethyl-butyl) -phenol, according to DE-OS 28 42 005 or monoalkylphenols or dialkylphenols having a total of 8 to 20 carbon atoms in the alkyl substituents according to DE-A 35 06 472, such as p-nonylphenyl, 3,5-di-t-butylphenol, pt-octylphenol, p-dodecylphenol, 2- (3,5-dimethyl-heptyl) -phenol and 4- (3, 5-dimethylheptyl) -phenol.

As further suitable components A) may be mentioned amorphous polyester carbonates, wherein phosgene was replaced by aromatic dicarboxylic acid units such as isophthalic acid and / or terephthalic acid units in the preparation. For further details, reference is made to EP-A 711 810.

Further suitable copolycarbonates with cycloalkyl radicals as monomer units are described in EP-A 365 916. Furthermore, bisphenol A can be replaced by bisphenol TMC. Such polycarbonates are available under the trademark APEC HT® from Bayer. Polycarbonates B)

The polycarbonates B) are inventively linear, so have little or no branching on. This distinguishes them from highly or hyperbranched polycarbonates.

Likewise according to the invention, the polycarbonates are oligomers. The number-average molecular weight Mn of the oligomeric polycarbonates is preferably from 250 to 200,000, more preferably from 250 to 100,000 and in particular from 300 to 20,000, very particularly preferably from 300 to less than 10,000 g / mol. The weight-average molecular weight Mw is preferably 280 to 300,000, particularly preferably 280 to 200,000 and in particular 350 to 50,000 g / mol.

The ratio Mw / Mn is usually from 1, 1 to 10, preferably 1, 2 to 8 and particularly preferably 1, 3 to 5. The molecular weights mentioned can be determined, for example, by gel permeation chromatography (GPC) or other suitable methods.

The polycarbonates B) preferably have a melting point or a glass transition temperature of -20 to 120, in particular -10 to 100 and very particularly preferably 0 to 8O ⁰ C, determined by differential scanning calorimetry (DSC) according to ASTM 3418/82.

The polycarbonates B) are preferably obtained by reacting a diol with an organic carbonate.

The polycarbonates may be aromatic or aliphatic. Aromatic polycarbons are e.g. in accordance with the processes of DE-B 1 300 266 by interfacial polycondensation or according to the process of DE-A 14 95 730 by reacting biphenyl carbonate (as organic carbonate) with bisphenols (as diol). Be¬ preferred bisphenol is 2,2-di (4-hydroxyphenyl) propane, generally referred to as bisphenol A.

Instead of bisphenol A, it is also possible to use other aromatic dihydroxy compounds, in particular 2,2-di (4-hydroxyphenyl) pentane, 2,6-dihydroxy-naphthalene, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenyl ether, 4,4 'Dihydroxy diphenylsulfite, 4,4'-dihydroxydiphenylmethane, 1, 1-di- (4-hydroxyphenyl) ethane or 4,4-dihydroxydiphenyl and mixtures of the aforementioned dihydroxy compounds. Particularly preferred aromatic polycarbonates are those based on bisphenol A or bisphenol A together with up to 30 mol% of the above-mentioned aromatic dihydroxy compounds.

Other, particularly preferred aromatic or aliphatic carbonates - hereinafter called carbonates i) - for the preparation of the polycarbonates are those of the formula ROf (CO) O] _n R where n = integer from 1 to 5, preferably 1 to 3. Bei The radicals R are each independently a straight-chain or branched aliphatic, aromatic / aliphatic or aromatic hydrocarbon radical having 1 to 20 C atoms. The two radicals R can also be linked together by forming a ring. It is preferably an aliphatic hydrocarbon radical and particularly preferably a straight-chain or branched alkyl radical having 1 to 5 C atoms, or a substituted or unsubstituted phenyl radical.

The carbonates i) may preferably be simple carbonates of the general formula RO (CO) OR, i. in this case, n = 1.

Dialkyl or diaryl carbonates i) can be prepared, for example, from the reaction of aliphatic, araliphatic or aromatic alcohols or phenols, preferably monoalcohols, with phosgene. Furthermore, they can also be prepared via oxidative carbonylation of the alcohols or phenols by means of CO in the presence of noble metals, oxygen or nitrogen oxides NO _x . For preparation methods of diaryl or dialkyl carbonates, see also "Ullmann ^'s Encyclopedia of Industrial Chemistry", 6th Edition, 2000 Electronic Release, Verlag Wiley-VCH.

Examples of suitable carbonates i) include aliphatic, aromatic / aliphatic or aromatic carbonates, such as ethylene carbonate, 1, 2 or 1, 3-propylene carbonate, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, dinaphthyl carbonate, ethyl phenyl carbonate, dibenzyl carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, Dibutyl carbonate, diisobutyl carbonate, dipentyl carbonate, dihexyl carbonate, dicyclohexyl carbonate, diheptyl carbonate, dioctyl carbonate, didecylacarbonate or didodecyl carbonate.

Examples of carbonates i) in which n is greater than 1 include dialkyl dicarbonates such as di (tert-butyl) dicarbonate or dialkyl tricarbonates such as di (tert-butyl) tricarbonate.

Aliphatic carbonates i) are preferably used, in particular those in which the radicals comprise 1 to 5 C atoms, for example dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate or diisobutyl carbonate or diphenyl carbonate as aromatic carbonate. Particularly preferred organic carbonates i) are dimethyl carbonate, diethyl carbonate and mixtures thereof.

The organic carbonates i) are reacted with at least one aliphatic or aromatic diol - referred to below as diol ii) - to the polycarbonate B). Here, the term diol or diol ii) stands for all compounds having two OH groups, even if it is in individual cases according to the nomenclature rules are not diols.

Suitable diols ii) have 3 to 20 C atoms. Examples are ethylene glycol, diethylene glycol, triethylene glycol, 1, 2 and 1, 3-propanediol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 1, 2, 1, 3 and 1, 4-butanediol, 1,2-, 1, 3 and 1, 5-pentanediol, 1, 6-hexanediol, 1, 7-heptanediol, 1,8-octanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol , 3-methyl-1,5-pentanediol, 2-methylpentanediol, 2,2,4-trimethyl-1,6-hexanediol, 3,3,5-trimethyl-1,6-hexanediol, 2,3,5-trimethyl -1, 6-hexanediol, cyclopentanediol, cyclohexanediol, cyclohexanedimethanol, bis (4-hydroxycyclohexyl) methane, bis (4-hydroxycyclohexyl) ethane, 2,2-bis (4-hydroxycyclohexyl) propane, 1,1 ^' - bis (4-hydroxyphenyl) -3,3-5-trimethylcyclohexane, resorcinol, hydroquinone, 4,4 ^{'dihydroxydiphenyl,} bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (hydroxymethyl) benzene , Bis (hydroxymethyl) toluene, bis (p-hydroxyphenyl) methane, bis (p-hydroxyphenyl) ethane, 2,2-bis (p-hydroxyphenyl) propane, 1,1-bis (p-hydroxyphenyl) cyclohexane , Dihydroxybenzophenone, difunctional e polyether polyols based on ethylene oxide, propylene oxide, butylene oxide or mixtures thereof, polytetrahydrofuran, polycaprolactone or polyesterols based on diols and dicarboxylic acids.

It is also possible to use addition products of the diols ii) with lactones (ester diols), such as caprolactone or valerolactone. Addition products of the diols ii) with dicarboxylic acids, such as adipic acid, glutaric acid, succinic acid or malonic acid, or addition products of the diols with esters of such dicarboxylic acids are also suitable.

Particularly preferred diols ii) are 1,3-propanediol and 2,2-diethyl-1,3-propanediol.

Compounds with three or more OH groups, e.g. Triols should preferably not be present or only in very small amounts, since otherwise branched and thus undesired polycarbonates can be formed.

Preferably, the reaction (condensation) of the organic carbonate i) takes place with the diol ii) in the presence of catalysts, it being possible in principle to use all the soluble or insoluble catalysts known for transesterification reactions. Suitable catalysts are, for example, the hydroxides, oxides, Metallalko koholate, carbonates, bicarbonates and organometallic compounds of the metals of I., II., III. and IV. Main Group of the Periodic Table, the III. and IV. group and the rare earth metals. Particularly suitable compounds of Li, Na, K, Cs, Mg, Ca, Ba ₁ Al, Ti ₁ Zr, Pb, Sn, Zn, Bi and Sb.

Also suitable as catalysts are tertiary amines, guanidines, ammonium compounds, phosphonium compounds, furthermore so-called double metal cyanide (DMC) catalysts, as described, for example, in DE-A 10138216 or in DE-A 10147712.

Examples of particularly suitable catalysts are LiOH, Li ₂ CO ₃ , K ₂ CO ₃ , KOH, NaOH, KOMe, NaOMe, MeOMgOAc, CaO ₁ BaO, KOtBu, TiCl ₄ , (mean Me methyl, Ac acetate, tBu tert-butyl) , Titanium tetraalcoholates or terephthalates, zirconium tetraalcoholates, tin octanoates, dibutyltin dilaurate, dibutyltin, bis (tributyltin oxide), tin oxalates, lead stearates, Sb ₂ O ₃ , ziretraisopropylate, diazabicyclooctane (DABCO), diazabicyclononene (DBN), diazabicycloundecene (DBU) , Imidazoles, such as imidazole, 1-methylimidazole or 1, 2-dimethylimidazole, titanium tetrabutylate, titanium tetraisopropylate, dibutyltin oxide, tin dioctoate and zirconium acetylacetonate, or mixtures thereof.

Preferably, potassium hydroxide, potassium carbonate, potassium bicarbonate, or mixtures thereof are used.

The amount of catalyst is usually from 50 to 10,000, preferably from 100 to 5000 ppm by weight, based on the diol used.

The reaction of the starting materials for polycarbonate B) is usually carried out in egg ner temperature from 0 to 300 ⁰ C, preferably 0 to 25O ⁰ C, particularly preferably at 60 to 200 ⁰ C and most preferably from 60 to 160 ⁰ C, and a Pressure of 0.1 mbar to 20 bar, preferably at 1 mbar to 5 bar, in reactors or Reaktorkaska¬ the, which are operated in batch, semi-continuous or continuous.

For example, the reaction can be carried out in bulk or in solution. It is generally possible to use all solvents which are inert towards the respective starting materials. Preference is given to using organic solvents, for example decane, dodecane, benzene, toluene, chlorobenzene, xylene, dimethylformamide, dimethylacetamide or solvent naphtha.

In a preferred embodiment, the reaction is carried out in bulk. The monofunctional alcohol or the phenol ROH liberated in the reaction can be removed from the reaction equilibrium to accelerate the reaction, for example by distillation, if appropriate under reduced pressure. If distilling off is intended, it is regularly advisable to use those carbonates which, in the course of the reaction, release alcohols or phenols ROH having a boiling point of less than 140 ° C. at the present pressure. There are various possibilities for stopping the intermolecular polycondensation reaction. For example, the temperature can be lowered to a range in which the reaction comes to a standstill. Furthermore, it is possible to deactivate the catalyst, with basic catalysts, for example by adding an acidic component, for example a Lewis acid or an organic or anorgani¬'s protic acid.

Further information on the preparation of the polycarbonates B) can be found, for example, in WO 01/94444 and WO 03/002630.

About the composition of the starting components and the residence time, the average molecular weight Mn or Mw of the polycarbonate B) can be adjusted.

It is possible to use the linear oligomeric polycarbonates B) as such, or as a mixture with other polymers, as described below as component C). Polymer blends of linear oligomeric polycarbonates B) and conventional polyesters A) such as polybutylene terephthalate (PBT) are commercially available as Ultradur® High Speed from BASF.

Other additives C)

As additives C), in particular all customary plastic additives, as well as of the components A) and B) different polymers, into consideration.

As component C), the molding compositions according to the invention 0 to 5, preferably 0.05 to 3 and in particular 0.1 to 2 wt .-% of at least one ester or amide of saturated or unsaturated aliphatic carboxylic acids having 10 to 40, preferably 16 to 22 C atoms with aliphatic saturated alcohols or amines having 2 to 40, preferably 2 to 6 carbon atoms.

The carboxylic acids can be 1- or 2-valent. Examples which may be mentioned are 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 having 30 to 40 carbon atoms).

The aliphatic alcohols can be 1 to 4 valent. Examples of alcohols are n-butanol, n-octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl glycol, pentaerythritol, with glycerol and pentaerythritol being preferred. The aliphatic amines may be monohydric to trihydric. Examples of these are stearylamine, ethylenediamine, propylenediamine, hexamethylenediamine, di (6-aminohexyl) amine, with ethylenediamine and hexamethylenediamine being particularly preferred. Preferred esters or amides are according to glycerol distearate, glycerol tristearate, ethylenediamine distearate, glycerol monopalmitate, glycerol trilaurate, glycerol monobehenate and pentaerythritol tetrastearate.

It is also possible to use mixtures of different esters or amides or esters with amides in combination, the mixing ratio being arbitrary.

Other conventional additives C) are, for example, in amounts of up to 40, preferably up to 30 wt .-% rubber-elastic polymers, which are also referred to as impact modifiers, elastomers or rubbers. These are preferably copolymers which are preferably made up of at least two of the following monomers: ethylene, propylene, butadiene, isobutene, isoprene, chloroprene, vinyl acetate, styrene, acrylonitrile and acrylic or methacrylic acid esters having 1 to 18 carbon atoms in the alcohol component.

Such polymers are e.g. in Houben-Weyl, Methods of Organic Chemistry, Vol. 14/1 (Georg Thieme Verlag, Stuttgart, 1961). Pages 392 to 406 and in the monograph of C.B. Bucknall, "Toughened Plastics" (Applied Science Publishers, London, 1977). In the following some preferred types of such elastomers are presented.

Preferred elastomers are the so-called. Ethylene-propylene (EPM) - or ethylene-propylene-diene (EPDM) rubbers. EPM rubbers generally have virtually no double bonds, while EPDM rubbers can have from 1 to 20 double bonds per 100 carbon atoms.

As diene monomers for EPDM rubbers, for example, conjugated dienes such as isoprene and butadiene, non-conjugated dienes having 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, cyclic dienes such as cyclopentadiene, cyclohexadienes, cyclooctadienes and dicyclopentadienes and also alkenylnorbornenes such as 5-ethylidene-2-norbornene, 5- Butylidene-2-norbornene, 2-methallyl-5-norbornene, 2-isopropenyl-5-norbornene and tricyclodienes such as 3-methyltricyclo (5.2.1.0.2.6) -3,8-decadiene or mixtures thereof. Preference is given to hexa-1, 5-diene, 5-ethylidenenorbornene and dicyclopentadiene. The diene content of the EPDM rubbers is preferably 0.5 to 50, in particular 1 to 8 wt .-%, based on the total weight of the rubber.

EPM or EPDM rubbers may preferably also be grafted with reactive carboxylic acids or their derivatives. Here are e.g. Acrylic acid, methacrylic acid and its derivatives, e.g. Glycidyl (meth) acrylate, and called 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, you can the rubbers also contain dicarboxylic acids such as maleic acid and fumaric acid or derivatives of these acids, for example esters and anhydrides, and / or monomers containing epoxy groups. These dicarboxylic acid derivatives or monomers containing epoxy groups are preferably incorporated into the rubber by addition of monomers containing dicarboxylic acid or epoxy groups of the general formulas I or II or III or IV to the monomer mixture

R ¹ C (COOR ² ) = C (COOR ³ ) R ⁴ (I)

CHR ⁷ = CH (CH ₂ ) _m O (CHR ⁶ ). CH A CHR ⁵ (HL)

CH ₂ = CR ⁹ COO (CH ² ) _p CH-CHR ⁸ (| V)

wherein R ¹ to R ^{9 represent} hydrogen or alkyl groups having 1 to 6 carbon atoms and m is an integer of 0 to 20, g is an integer of 0 to 10 and p is an integer of 0 to 5. The radicals R ¹ to R ⁹ preferably denote hydrogen, where m is 0 or 1 and g is 1. The corresponding compounds are maleic acid, fumaric acid, maleic anhydride, allyl glycidyl ether and vinyl glycidyl ether.

Preferred compounds of the formulas I, II and IV are maleic acid, maleic anhydride and epoxy groups-containing esters of acrylic acid and / or methacrylic acid, such as glycidyl acrylate, glycidyl methacrylate and the esters with tertiary alcohols, such as t-butyl acrylate. Although the latter have no free carboxyl groups, their behavior is close to the free acids and are therefore termed monomers with latent carboxyl groups.

Advantageously, the copolymers consist of 50 to 98% by weight of ethylene, 0.1 to 20% by weight of monomers containing epoxy groups and / or methacrylic acid and / or monomers containing acid anhydride and the remaining amount of (meth) acrylic acid esters. Particular preference is given to copolymers of from 50 to 98, in particular from 55 to 95,% by weight of ethylene; 0.1 to 40, in particular 0.3 to 20 wt .-% glycidyl acrylate and / or glycidyl methacrylate, (meth) acrylic acid and / or maleic anhydride; and 1 to 45, in particular 10 to 40 wt .-% 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.

The above-described ethylene copolymers can be prepared by methods known per se, preferably by random copolymerization under high pressure and elevated temperature. Corresponding methods are generally known.

Preferred elastomers are also emulsion polymers, their preparation e.g. in Blackley, "Emulsion Polymerization", Applied Science Publ., London 1973. The emulsifiers and catalysts which can be used are known per se.

Basically, homogeneously constructed elastomers or those with a shell structure can be used. The shell-like structure is determined by the order of addition of the individual monomers; the morphology of the polymers is also influenced by this order of addition.

By way of example, as monomers for the preparation of the rubber portion of the elastomers, acrylates such as e.g. N-butyl acrylate and 2-ethylhexyl acrylate, corresponding methacrylates, butadiene and isoprene and their mixtures called. These monomers can be reacted with further monomers, e.g. Styrene, acrylonitrile, vinyl ethers and weite¬ ren acrylates or methacrylates such as methyl methacrylate, methyl acrylate, ethyl acrylate and propyl acrylate are copolymerized.

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

In addition to the rubber phase, one or more hard components (with Glas¬ transition temperatures of more than 2O ⁰ C) on the structure of the elastomer involved, these are nitrile generally prepared by polymerization of styrene, acrylonitrile, methacrylic acid, σ-methylstyrene, p-methylstyrene , Acrylsäureestem and Methacrylsäureestem such as methyl acrylate, ethyl acrylate and methyl methacrylate produced as major monomers. In addition, smaller proportions of other comonomers can also be used here. In some cases, it has proven to be advantageous to use emulsion polymers which have reactive groups on the surface. Such groups are, for example, epoxy, carboxyl, latent carboxyl, amino or amide groups and functional groups obtained by concomitant use of monomers of the general formula

R ¹⁰ R ¹¹

CH ₂ = C -XNCR ¹²

O

can be introduced, wherein the substituents can have the following meaning:

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, optionally with O or

May be substituted by N-containing groups,

X is a chemical bond, a C ₁ - to C ₁₀ -alkylene or C ₆ -C ₁₂ -arylene group or

O

- C - Y

Y O-Z or NH-Z and

Z is a C ₁ - to Cio-alkylene or C ₆ - to C ₂ -arylene group.

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

Other examples which may be mentioned are acrylamide, methacrylamide and substituted esters of acrylic acid or methacrylic acid, such as (Nt-butylamino) -ethyl methacrylate, (N, N-dimethyl) amino) ethyl acrylate, (N, N-dimethylamino) -methyl acrylate and (N, N-diethylamino) ethyl acrylate.

Furthermore, the particles of the rubber phase can also be crosslinked. Examples of monomers acting as crosslinkers are buta-1,3-diene, divinylbenzene, diallyl phthalate and dihydrodicyclopentadienyl acrylate, and also the compounds described in EP-A 50 265.

Furthermore, so-called graft-linking monomers may also be used, i. Monomers having two or more polymerizable Dop¬ pelbindungen that re¬ act in the polymerization at different speeds. Preferably, those compounds are used in which at least one reactive group polymerizes at about the same rate as the other monomers, while the other reactive group (or reactive groups) e.g. significantly slower polymerizing (polymerizing). The different polymerization rates entail a certain proportion of unsaturated double bonds in the rubber. If a further phase is subsequently grafted onto such a rubber, the double bonds present in the rubber react at least partially with the graft monomers to form chemical bindings, ie. the grafted phase is at least partially linked to the graft base via chemical bonds.

Examples of such graft-crosslinking monomers are allyl-containing monomers, in particular allyl esters of ethylenically unsaturated carboxylic acids, such as allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl itaconate or the corresponding monoallyl compounds of these dicarboxylic acids. In addition, there are a variety of other suitable graft-linking monomers; for further details, reference is made here, for example, to US Pat. No. 4,148,846.

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

In the following, some preferred emulsion polymers are listed. First, graft polymers having a core and at least one outer shell are to be mentioned here, which have the following structure:

These graft polymers, in particular ABS and / or ASA polymers in amounts of up to 40% by weight, are preferably used for the impact modification of PBT, if appropriate in a mixture with up to 40% by weight of polyethylene terephthalate. Respective blend products are available under the trademark Ultradur®S (formerly Ultrablend®S from BASF).

Instead of graft polymers having a multi-shell structure, homogeneous, i. single-shell elastomers of buta-1, 3-diene, isoprene and n-butyl acrylate or copolymers thereof are used. These products can also be prepared by Mit¬ use of crosslinking monomers or monomers having reactive groups.

Examples of preferred emulsion polymers are n-butyl acrylate / (meth) acrylic acid copolymers, n-butyl acrylate / glycidyl acrylate or n-butyl acrylate / glycidyl methacrylate copolymers, graft polymers having an inner core of n-butyl acrylate or butadiene-based and an outer shell of the above copolymers and copolymers of ethylene with comonomers which provide reactive groups.

The described elastomers may also be prepared by other conventional methods, e.g. by suspension polymerization.

Silicone rubbers, as described in DE-A 37 25 576, EP-A 235 690, DE-A 38 00 603 and EP-A 319 290, are likewise preferred. Of course, it is also possible to use mixtures of the abovementioned rubber types.

As fibrous or particulate fillers C) are carbon fibers, glass fibers, glass beads, amorphous silica, asbestos, calcium silicate, calcium metasilicate, magnesium carbonate, kaolin, chalk, powdered quartz, mica, barium sulfate and feldspar called in amounts up to 50 Wt .-%, in particular up to 40% wer¬ the used.

Preferred fibrous fillers are carbon fibers, aramid fibers and potassium titanate fibers, glass fibers being particularly preferred as E glass. These can be used as rovings or chopped glass in the commercial forms ein¬.

Mixtures of glass fibers C) with component B) in the ratio of 1: 100 to 1: 2 and preferably from 1:10 to 1: 3 are particularly preferred.

For better compatibility with the thermoplastic, the fibrous fillers can be surface-pretreated with a silane compound. Suitable silane compounds are those of the general formula

(X- (CH ₂ ) _n ) _k -Si- (OC _m H _{2m + 1} ) ₄ - _k

in which the substituents have the following meanings:

X NH ₂ -, CH ₂ -CH-, HO-, O

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, aminobutyltriethoxysilane and the corresponding silanes which contain a glycidyl group as substituent X.

The silane compounds are generally used in amounts of 0.05 to 5, preferably 0.5 to 1.5, and in particular 0.8 to 1 wt .-%, based on C), for surface coating. Also suitable are acicular mineral fillers. In the context of the invention, needle-shaped mineral fillers are understood to mean a mineral filler with a pronounced, needle-like character. An example is acicular wollastonite. Preferably, the mineral has an L / D (length / diameter) ratio of 8: 1 to 35: 1, preferably 8: 1 to 11: 1. The mineral filler may optionally be vorbe¬ with the abovementioned silane compounds vorbe¬; however, pretreatment is not essential.

Kaolin, calcined kaolin, wollastonite, talc and chalk are mentioned as further fillers.

As component C), the thermoplastic molding compositions of the invention may contain conventional processing aids such as stabilizers, antioxidants, agents against thermal decomposition and decomposition by ultraviolet light, lubricants and mold release agents, colorants such as dyes and pigments, nucleating agents, plasticizers, etc.

Examples of oxidation inhibitors and heat stabilizers are sterically hindered phenols and / or phosphites, hydroquinones, aromatic secondary amines such as diphenylamines, various substituted representatives of these groups and mixtures thereof in concentrations of up to 1% by weight, based on the weight of the called thermo¬ plastic molding compounds.

UV stabilizers which are generally used in amounts of up to 2% by weight, based on the molding composition, of various substituted resorcinols, salicylates, benzotriazoles and benzophenones may be mentioned.

It is possible to add inorganic pigments, such as titanium dioxide, ultramarine blue, iron oxide and carbon black, and furthermore organic pigments, such as phthalocyanines, quinacridones, perylenes, and also dyes, such as nigrosine and anthraquinones, as colorants.

The nucleating agents used may be sodium phenylphosphinate, aluminum oxide, silicon dioxide and, preferably, talc.

Other lubricants and mold release agents are usually used in amounts of up to 1% by weight. Preferred are long-chain fatty acids (eg stearic acid or behenic acid), their salts (eg Ca or Zn stearate) or montan waxes (mixtures of straight-chain, saturated carboxylic acids with chain lengths of 28 to 32 C atoms) and Ca or Na. Montanate and low molecular weight polyethylene or polypropylene waxes. Examples of plasticizers are dioctyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, hydrocarbon oils, N- (n-butyl) benzenesulfonamide.

The polymer blends according to the invention may contain from 0 to 2% by weight of fluorine-containing ethylene polymers. These are polymers of ethylene with a fluorine content of 55 to 76 wt .-%, preferably 70 to 76 wt .-%.

Examples of these are polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoro-propylene copolymers or tetrafluoroethylene copolymers with relatively small proportions (generally up to 50% by weight) of copolymerizable ethylenically unsaturated monomers. These are e.g. by Schildknecht in "Vinyl and Related Polymers", Wiley-Verlag, 1952, pages 484 to 494 and by Wall in "Fluoropolymers" (Wiley Interscience, 1972).

These fluorine-containing ethylene polymers are homogeneously distributed in the molding compositions and preferably have a particle size d ₅₀ (number average) in the range of 0.05 to 10 .mu.m, in particular from 0.1 to 5 .mu.m. 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.

Preparation and properties of polymer blends

The polymer blends according to the invention can be prepared by processes known per se, in which the starting components are mixed in customary mixing devices, such as screw extruders, Brabender mills or Banbury mills, and then extruded. After extrusion, the extrudate can be cooled and zerklei¬ nert. It is also possible to premix individual components and then to add the remaining starting materials individually and / or likewise mixed. The mixing temperatures are usually 230 to 29O ⁰ C.

According to a further preferred procedure, the components B) and, if appropriate, C) can be mixed with a polyester prepolymer A '), formulated and granulated. The granules obtained are then condensed in the solid phase under inert gas continuously or discontinuously at a temperature below the melting point of component A) to the desired viscosity.

The polymer blends according to the invention are distinguished by good flowability combined with good mechanical properties, high heat distortion and chemical resistance and good dimensional stability. In particular, the processing of the individual components (without clumping or caking) is possible without problems and in short cycle times, so that in particular thin-walled components come into consideration as an application.

The invention also provides the use of the polymer blends according to the invention for the production of moldings, films, fibers and foams, as well as the moldings, films, fibers and foams obtainable from the polymer blend.

The use of the flow-improved polyester according to the invention is conceivable in almost all injection molding applications. The flow improvement allows a lower melt temperature and can thus lead to a significant reduction in the overall cycle time of the injection molding process (reduction of the production costs of an injection molded part). Furthermore, lower injection pressures during the processing are necessary, so that a lower total closing force is required on the injection molding tool (lower investment costs in the injection molding machine).

In addition to the improvements in the injection molding process, the lowering of the melt viscosity can lead to significant advantages in the actual component design. Thus, thin-walled applications, e.g. previously were not feasible with filled polyester types, are produced by injection molding. Analogous to this, a reduction of the wall thicknesses and thus a reduction of the parts weights is conceivable in existing applications through the use of reinforced but more easily flowing polyester types.

The blends according to the invention are suitable for the production of fibers, films and moldings of any kind, in particular for applications as heels, switches, housing parts, housing cover, headlight background (bezel), shower head, fittings, irons, rotary switches, stove knobs, fryer lids, door handles, ( Rear) mirror housings, (rear) windscreen wipers or fiber optic sheathing.

In the case of electrical and electronic devices, connectors, plug connector parts, plug connector components, wiring harness components, circuit carriers, circuit carrier components, three-dimensionally injection-molded circuit carriers, electrical connection elements, mechatronic components or optoelectronic components can be produced with the flow-improved polyester.

In the car interior is a use for dashboards, steering column switch, Sitz¬ parts, headrests, center consoles, gear components and door modules, in the car exterior door handles, headlight components, exterior mirror components, windscreen wiper components, windscreen wiper housing, grille, roof rails, sunroof frame and body exterior parts possible. For the kitchen and household sector, the use of the flow-improved Polyes¬ ters for the production of components for kitchen appliances, such as fryers, Bügelei¬ sen, buttons, and applications in the garden leisure sector, eg components for irrigation systems or garden tools possible.

In the field of medical technology, inhaler housings and their components can be more easily realized by means of flow-improved polyesters.

Transmission electron microscopy was used to examine the morphology of selected blends according to the invention. It shows a good dispersion of the particles in the blend. Particle sizes of 20 to 500 nm were observed.

Another subject of the invention is the use of the linear, oligomeric polycarbonates as defined as component B), to increase the flowability of polyesters esters.

Examples

Component A:

Polybutylene terephthalate (PBT) having a viscosity number VZ of 130 ml / g, measured according to DIN 53728 or ISO 1628 on a 0.5 wt .-% solution in a 1: 1 mixture of phenol and o-dichlorobenzene at 25 ⁰ C. , and a carboxyl end group content of 34 meq / kg. The commercial product Ultradur® B 4520 from BASF was used. The PBT contained as

Component C1:

Pentaerythritol tetrastearate in an amount of 0.65 wt .-%, based on 100 wt .-% of component A.

Component B:

A three-necked flask with stirrer, reflux condenser and internal thermometer was used. 1 mol of the diol (see Table 1) was added and 1 mol was added with stirring

Diethylcarbonat and 0.1 g of potassium carbonate was added and heated to 13O ⁰ C. The reaction mixture was stirred for 2 hours, wherein the temperature of the mixture decreased by the onset of silk cooling of the liberated ethanol. After the above-mentioned 2 hours, the reflux condenser replaced by a descending cooler and the ethanol was distilled off, during which increased the temperature of the mixture slowly to 18O ⁰ C. The distilled-off ethanol was collected in a cooled round-bottomed flask, weighed out and the conversion was thus determined as a percentage of the theoretically possible full conversion, see Table 1.

At the reaction product of the molecular weight was determined as follows: Weight average Mw and number average Mn by gel permeation chromatography at 2O ⁰ C and four hin¬ behind the other connected columns (2 x 1000 Å, 2 x 10,000 A), each column 600x7,8 mm Type PL-gel of Fa. Phenomenex; Eluent dimethylacetamide 0.7 ml / min, standard polymethyl methacrylate (PMMA).

The glass transition temperature Tg of the reaction product was determined by differential scanning calorimetry (DSC) according to ASTM 3418/82, the second heating curve being evaluated.

Table 1: linear oligomeric polycarbonate B

Component C2:

Glass fibers with a mean length of 4 mm and a mean diameter of 4 microns. The commercial product Cratec® Plus Chopped Strands from Owens Corning Fibers was used.

Component X (instead of B) for comparison:

The flow improver Joncryl® ADF 1500 from Johnson Polymers was used, a styrene copolymer having a molecular weight Mw of 2800 g / mol and a glass transition temperature Tg of 56 ^° C.

Production and properties of blends

The components were homogenized according to the compositions listed in Table 2 on a twin-screw extruder ZSK 25 from Messrs. Werner & Pfleiderer at 26O ⁰ C, the mixture extruded into a water bath, granulated and dried. Out The granules were sprayed on an injection molding machine at 26O ⁰ C melt temperature and 80 ⁰ C mold surface temperature specimens and tested.

The following properties were determined:

Viscosity number VZ measured according to ISO 1628 on a 0.5% strength by weight solution in a 1: 1 mixture of phenol and o-dichlorobenzene at 25 ° C.,

Melt viscosity measured at 260 ⁰ C melt temperature and varying shear (oscillating) in a plate-plate rheometer SR5000 from Fa. Rhenium Ometric Scientific with 25 mm plate diameter and a height h = 1 mm, Vor¬ heating time 1 min, measurement time 20 min at 26O ⁰ C,

Melt volume ratio (MVR) at 275 ° C melt temperature and 2.16 kg load according to EN ISO 1133,

Stress at break, elongation at break and modulus of elasticity (modulus of elasticity) in tension on shoulder bars at 23 ° C. according to ISO 527-2: 1993,

- notched impact strength a _k at 23 ⁰ C according to ISO 179-2 / IeA (F),

Flowability through the spiral test: with an injection molding machine at 26O ⁰ C polymer melt temperature and 80 ⁰ C mold surface temperature, a test spiral of 2 mm diameter prepared and then determines the length of the spiral obtained. The longer the spiral, the higher the flowability of the polymer.

The compositions and the results of the measurements are to be taken from Table 2.

Table 2: Composition and properties (V for comparison, nb not determined)

¹⁾ Component A contains 0.65% by weight of pentaerythritol tetrastearate as component C1

²⁾ 275 ° C melt temperature, 2.16 kg rated load

Continuation of Table 2:

¹⁾ Component A contains 0.65 wt .-% pentaerythritol tetrastearate as component C1 ²⁾ 275 ° C melt temperature, 2.16 kg rated load

The examples show that even 1.5% by weight of the linear oligomeric polycarbonate B1 increased the flowability as measured in the flow spiral test by 84% (comparison of Example 1V with Example 3). Similarly, 1.5% by weight of the polycarbonate B2 increased flowability by 34% (Example 1V vs. Example 6). At higher levels of polycarbonate B, the flowability improved again.

The increase in the flowability was particularly pronounced in glass fiber-containing blends. Thus, the flowability increased by the addition of only 1% by weight of the polycarbonate B2 by 96% (Example 8V vs. 10).

In this case, the advantageous mechanical properties of the moldings were retained, ie the improved flowability was not bought with a worse mechanics. On the other hand, a commercially available flow improver (component X) did not improve the flowability, as the flow spiral values of examples 1V, 12V and 13V show.

Claims

claims

1. polymer blend comprising components A) to C), the sum of which amounts to 100% by weight,

A) from 30 to 99.99% by weight of at least one polyester A),

B) 0.01 to 70 wt .-% of at least one linear, oligomeric polycarbonate B), and

C) 0 to 80 wt .-% of further additives C).

2. Polymer blend according to claim 1, characterized in that the polyester A) is aromatic.

3. Polymer blend according to claims 1 to 2, characterized in that the polyester A) is selected from polyethylene terephthalate and polybutylene terephthalate.

4. Polymer blend according to claims 1 to 3, characterized in that the polycarbonate B) has a number average molecular weight of 250 to 200,000 g / mol.

5. Polymer blend according to claims 1 to 4, characterized in that the polycarbonate B) has a melting point or a glass transition temperature of

-20 to 12O ⁰ C, determined by DSC according to ASTM 3418/82.

6. Polymer blend according to claims 1 to 5, characterized in that the polycarbonate B) is obtainable by reacting a diol with an organic carbonat nat.

7. A polymer blend according to claims 1 to 6, characterized in that one uses as diol 1, 3-propanediol, 2,2-diethyl-1, 3-propanediol or mixtures thereof ver¬.

8. A polymer blend according to claims 1 to 7, characterized in that one uses as organic carbonate dimethyl carbonate, diethyl carbonate or mixtures thereof Mi¬.

9. Use of the polymer blend according to claims 1 to 8 for the production of moldings, films, fibers and foams.

10. Shaped bodies, films, fibers and foams, obtainable from the polymer blend according to claims 1 to 9.

11. The use of linear, oligomeric polycarbonates as defined as component B) in claims 1 to 8, for increasing the flowability of polyesters.