DE102005048769A1 - Process for the preparation of polyesters having improved manufacturing and service properties for use in the packaging industry - Google Patents

Abstract

The present invention relates to a method for producing polyester nanocomposites, in particular polyalkylene terephthalate nanocomposites, with improved performance properties. The polyester nanocomposites contain, in particular, organophilic nanosheet silicates of higher temperature resistance in the range from 0.01 to 20% by weight as well as basic additives which are added in situ during polyester production. The polyester anocomposites mentioned are particularly suitable for the production of packaging materials such as foils and bottles, which have an increased barrier behavior against the permeation of O¶2¶, CO¶2¶ and reduce UV radiation. DOLLAR A The peculiarity of the way in which a thermostable organophilic nanosilicate silicate additive adapted for the special temperature conditions of the PET melt polycondensation and SSP post-condensation is introduced enables the polyester in-situ condensation in the melt phase and the subsequent solid-phase condensation to run smoothly . The introduced, well-exfoliated nanosilicate silicates also cause a considerable acceleration of the SSP post-condensation rate of the polyester nanocomposite itself.

Description

The The present invention relates to a method of using a Substance for achieving improved manufacturing and service properties in the application of polyester types in the packaging industry, according to the features in the preamble of the main claim.

polyester (Homo-PET, Co-PET) is a cheap one thermoplastic plastic, due to its range of properties in areas of technical applications but also for packaging materials (Food packaging films, beverage containers, cosmetics, etc.) application has found. Polyester as such are therefore not just the raw material for the Textile industry, but also in significant quantities to technical Films, but especially packaging materials (containers, food films, Beverage bottles etc.) further processed.

Of the PET demand also shows for the future is a progressive growth for bottle-grade types (disposable and Returnable beverage bottles for soft drinks as light and unbreakable alternative to the heavier glass bottle, better transport logistics as well as more favorable tons / km-ratio) and for multilayer bottles for beer and fruit juices based on PET and MXD6 as a cheaper alternative to the currently still expensive PEN packaging applications.

• – Form- und Farbgebung der PET-Flasche sind unbeschränkt: Verschiedene individuelle Designs sind lieferbar. Das neue Gebinde unterstützt damit nicht nur die Markteinführung von neuen Sorten wie etwa Bier-Mix-Getränken, sondern lenkt auch die Aufmerksamkeit der Verbraucher auf traditionelle Biersorten. Dies erlaubt Brauern ihre Marken im stagnierenden Biermarkt aus der Masse des übrigen Angebots hervorzuheben. Wie bereits seit längerem in "Outfit" gehört, lässt sich nun die eigene Markenidentität bereits mit der Bierflasche aufbauen.
• – Das Gesamtgewicht von Produkt und Flasche reduziert sich um etwa ein Drittel: Dank der Leichtigkeit der PET-Gebinde kann „netto" mehr Bier per Lkw transportiert werden. Dies schont über stark verminderten Kraftstoffverbrauch die Umwelt und verringert die Distributionskosten; der Konsument trägt letztendlich weniger an der Verpackung, als am Getränk. Die Bruchsicherheit erschließt den Abfüllern zusätzliche Absatzchancen für Veranstaltungen, bei denen Bier-Behälter aus herkömmlichen Verpackungsmaterial (Glas) verboten sind. Gleichzeitig können während des Füllvorganges in der Brauerei keine Flaschen zerbrechen.

Important advantages of PET bottles are in the following aspects:

• - The shape and color of the PET bottle are unlimited: Different individual designs are available. The new container not only supports the market launch of new varieties such as beer mix drinks, but also draws consumers' attention to traditional beers. This allows brewers to highlight their brands in the stagnant beer market from the bulk of the rest of the offer. As has long been part of "Outfit", the own brand identity can now be built up with the beer bottle.
• - The total weight of the product and bottle is reduced by about a third: Thanks to the light weight of the PET containers, "more" beer can be transported by truck, saving on the environment and reducing distribution costs through a significant reduction in fuel consumption, ultimately reducing the consumer's consumption Breakage resistance provides fillers with additional sales opportunities for events that prohibit the use of beer containers made of traditional packaging material (glass), while at the same time no bottles break during the filling process in the brewery.

On The NOVAPACK 2000 conference in the US that the PET bottle is in Beer beverage market a growing acceptance, despite the currently higher production price across from an ordinary one PET bottle for Soft drinks and mineral water.

The higher price of a PET beer bottle results from the necessary barrier technology Barrier construction to prevent the permeation of CO ₂ from the beer, but above all the permeation of O ₂ in the beer (the durability of a beer is thereby 80% of the oxygen sensitivity of the individual Flavors and ingredients of each beer itself). In addition to permeation, however, the possibility of migration of aroma and ingredients from the beer into the bottle wall and of additives and monomers in the filling medium (beer), as well as the UV stability, should not be underestimated.

1 illustrates which important functions a correspondingly to be modified PET bottle for beer bottlings (also applies to flavor-sensitive juices, etc.) must meet in particular. So far, the main focus of the beer beverage market has been on the following different PET packaging innovations, multi-layer bonding, metallization and SiOx coating processes, in particular to address the important aspect of the improved O ₂ barrier effect (very low levels of permeable oxygen are already compromised the beer flavor considerably), since commercially customary PET bottles for in-bottle pasteurization stage poorly suited and because of the low O ₂ barrier also not allow very long storage periods of premium beers.

Approximately 80% of all present on the beer beverage market located barrier bottles are multi-composite bottles.

Nanocor Inc. developed together with Mitsubishi Gas Chemical on the basis of nylon MXD6 one 3-layer film composite PET-N-MXD6-PET; with only nano layer silicates incorporated into the nylon MXD6 intermediate film.

In particular, the nylon-MXD6 / nanosilicate inner layer acts as the actual high-barrier layer, whereby the additional incorporation of small amounts of organoclay into N-MXD6, according to Nanocor (Technical Paper, Nanocor Inc.), leads to CO ₂ permeation over the pure Reduced N-MXD6 interlayer to 50% and correspondingly reduced O ₂ permeation to 25%. Nylon MXD6 itself is already a higher-priced matrix polymer.

These are relative barrier improvements due to the use of a specific organoclays, as are known somewhat for single-layer PA 6 nanocomposite barrier films (see 2 ).

From data from Nanocor-Inc. Furthermore, it is known that well-exfoliated nanosheet silicates in a polymer matrix can also improve the UV barrier of the resulting polymer nanocomposite 3 to this invention description with reference to a PET-N-MXD6-PET multilayer film (curve line M9) well in the wavelength range λ = 250 ... 390 nm can be seen. It has been agreed among polyester experts that the technical problems of incorporation of nanosheet silicates into polyester as matrix polymer have not yet been solved. For example, Karl Kamena of NANOCOR describes in a technical documentation on "Nanocomposite Technologies for Barrier and Thermal Improvements in PET Containers" [Karl Kamena, Technical Papers, Nanocor Inc. 2000] the deficiencies such as insufficient exfoliation, increase in crystallization rate, and increasing discoloration nanodispersive incorporation of organophilic montmorillonite into the polyester matrix via the PET condensation process is still considered unresolved.

• – ungenügende thermische Eigenstabilität der eingesetzten Nanoschichtsilikate (Zersetzungserscheinungen verbunden mit starken Schäumen im Reaktor)
• – unzureichende Exfoliergüte in der Polyestermatrix
• – starke Verfärbungen der Polyesterschmelze
• – starke Kristallinität (Zunehmende Versprödung)

In the researched publications solutions for processes for the production of materials for the production of PET-based packaging containers by incorporation of Nanoschichtsilikatadditiven shown, but where the following problems have not yet been solved for a large-scale implementation, especially in the in-situ melt phase condensation route for the preparation of Polyesternanocompsiten :

• Insufficient thermal inherent stability of the nanosheet silicates used (decomposition phenomena associated with strong foams in the reactor)
• - insufficient exfoliation in the polyester matrix
• - strong discoloration of the polyester melt
• - strong crystallinity (increasing embrittlement)

The Polymer production for Bottle-grade applications not only require constant innovation on the market Field of polycondensation catalysts, stabilizers and co-monomers, but also the adaptation of the PET material itself for special Applications like hot fill and aseptic packaging containers.

• – Inhibierung von Ti-basierenden Katalysatorsystemen in der Polykondensationsphase durch chemische Verunreinigungen in den natürlich vorkommenden MMT-Nanoschichtsilikaten
• – Erlangung unzureichender Molmassen in der in-situ Polykondensation,
• – starkes Aufschäumen der Polymerschmelze in der Umesterungs, Veresterungsphase- und Polykondensationsphase,
• – erhebliche Vakuumprobleme in der Polykondensationsstufe,
• – unzureichende Exfolierung der Nanoschichtsilikate.

From a literature and patent research as well as various expert discussions with polyester manufacturers (in particular bottle-grade PET manufacturers), it became apparent that the use of commercially available organophilic nanosheet silicates for the production of PBT and PET nanocomposites through the technology of in situ polymerization was accompanied by manifold difficulties with the DMT or PTA process, which hitherto did not permit large-scale implementation for the following reasons:

• - Inhibition of Ti-based catalyst systems in the polycondensation phase by chemical impurities in the naturally occurring MMT nanosheet silicates
• Obtaining insufficient molar masses in the in-situ polycondensation,
• Strong foaming of the polymer melt in the transesterification, esterification phase and polycondensation phase,
• Considerable vacuum problems in the polycondensation stage,
• - insufficient exfoliation of the nanosheet silicates.

In particular, in the case of food films and especially in beverage bottles (beer bottles, soft drink bottles and juice bottles), however, there is still the interest of the relevant industry to further significantly improve the gas barrier properties of the PET-based packaging units, without costly additional processes such as multilayer film composites, metallization or SiOx-Be to use coating processes. Ideal here would be a corresponding Polyesternanocomposite, which consists only of the polyester matrix and an additive component and thus while maintaining the originally set in Polyesternanocomposite mechanical, UV and barrier properties allows multiple material or chemical recycling with reasonable technical effort.

Although, for example, in the case of the thermoplastic matrix polyamide 6, nanosheet silicates have proved to be very successful in obtaining commercial polyamide nanocomposite packaging materials (in particular food packaging films) both via melt-cake compounding processes and, above all, via the in situ polymerization process (Honeywell: Aegis ^™ NC (XA-2908 Type), UBE Industries, Bayer AG: Durethan ^® KU2-2601), are above all the technical-technological problems for polyester especially for the in-situ polymerization with Nanoschichtsilikaten (thermal decomposition of Nanoschichtsilikate, foaming in the Reactors, considerable vacuum disturbances, insufficient polymer viscosities, insufficient dispersing quality) have not yet been solved. Although it was possible to obtain reasonably satisfactory PET nanocomosite materials through the alternative melt compounding route in twin screw extruders, the improvements in gas barrier properties achieved with it are only to be assessed as low compared to expectations.

• – Alkylammonium modifizierte Nanoschichtsilikate setzen bei der Schmelzecompoundierroute die Intrinsische Viskosität von PET bzw. Co-PET sehr stark herab.
• – Erhöhte Gehalte an Nanoschichtsilikaten erhöhen bei guter Exfolierung die Schmelzeviskosität erheblich.
• – Bei zu schneller Vakuumfahrweise setzt ein starkes Schäumen bei der Schmelzephasenkondensation ein.

Eastman Chemical Company, as a large scale polyester producer, has been most intensively involved in the melt and in-situ incorporation of unmodified and modified nanosheet silicates into the polyester matrix (preferably PET) and in one of its 1998 base patents (US 97/24221 or WO98 / 29499) the following significant results have been found:

• Alkylammonium-modified nanosheet silicates greatly reduce the intrinsic viscosity of PET or Co-PET in the melt-compounding route.
• - Increased levels of Nanoschichtsilikaten increase with good exfoliation, the melt viscosity significantly.
• - If the vacuum mode is too fast, strong foaming occurs in the melt phase condensation.

Without a good dispersion of the nanosheet silicates and the establishment of particle sizes <20 nm (a maximum on isolated phyllosilicate platelets and a minimum of stacking units is necessary) can the gas barrier as well as the optical transparency of polymer nanocomposites not essential be improved. With increasing amount of nanosheet silicate or better exfoliation of the silicate platelets increases the melt viscosity of polyester in the low shear region, as in slow running batch reactors or disc-ring finisher reactors, which is what i.a. leads to melt viscosity ranges> 30,000 poise and associated with lowered polycondensation rate due to delayed EG-condensate diffusion from the melt.

Eastman prefers therefore low in its patent, the production of low molecular PET nanocomposite precursor materials over the Melt condensation in the reactor (IV range: 0.3 .... 0.5 dl / g), the then in a subsequent SSP stage to higher molecular weight PET nanocomposites (0.7 .... 1.0 dl / g) in solid phase with accelerated solid phase condensation times to higher viscosity Polyester can be post-condensed. Organoclay contents above 6% by weight but reduce the SSP speed then stronger again.

The best oxygen barrier properties had Eastman in this patent with Ethoquad 18/25 from Akzo Chemie America (octadecyl [polyoxyethylene (15)] ammonium chloride) -) also referred to as Ethomeen 18/25 modified montmorillonites with 5.0 ^cm3 / 100 microns × 24 × m ² × weight bar for about 12th% addition amount of Ethoquad 18/25 organoclay and 9.7 ^cm3 / 100 microns × 24 × m ² × wt bar for about 7 wt.% of Ethoquad 18 / 25-MMT in the PET matrix (in situ incorporation). Ethoquad 18/25 (Ethomeen)

As reference value a value of 45 ^cm3 / 100 microns 24 m × ² × bar was led for a comparative film of Co-PET without nano-layer silicate from Eastman in this patent. The Ethoquad 18/25 MMT additive had been prepared by Eastman on a laboratory scale only; So far, none of the world's nanoclay manufacturers such as Nanocor Inc., Southern Clay Products; Südchemie AG, Paikong Industries, Kunimine Industries etc. have commercialized the preparation of this specifically described organophilic MMT additive.

Eastman also used a variant of the self-modification of Na-MMT with aminododecanoic acid in some examples in the in situ modification of PET (this corresponds to the commercially available 124TL organoclay type from Nanocor Inc.) to provide a corresponding in the corresponding films of about 30-34 cm to obtain oxygen barrier value ^3/100 micron 24 × m ² × bar with appropriate addition amount of the organoclays of respectively 3-11% by weight.

Eastman renounced his claims also on possible stoichiometric Balancing of the acidic pH produced by the aminododecanoic acid in the reaction melt, which are known to extremely high DEG levels (definitely mentioned as such in the Eastman patent itself), and thus lead to greatly lowered melting points of the polyester.

All in-situ condensation experiments in the cited Eastman patent on a miniature scale in a simple round bottom flask made of glass with stirrer in the 100 g scale at melt viscosities of IV = 0.30-0.45 dl / g usually the polycondensation has already been stopped was the low molecular weight precursor material for the SSP reaction to get by smashing the piston. By oversizing the oil vacuum pump and the controlled vacuum control (visual inspection) could the mentioned foaming the Melt under these conditions can still be easily handled, unlike your own orienting experiments in autoclave scale according to the present invention description, where the strong foaming to blockages of the vapor lines and the condenser by entrained and strongly foaming Monomer both in the esterification phase and in the initial one Vacuum program led.

The with reference to the invention described below (cited experimental examples in laboratory scale) considered to be promising incorporation of a thermal stable organophilic nanosiloate silicate based on sodium montmorillonite modified with the hydrochloride of aminododecanoic acid in the form of commercial nanosheet silicate type I24TL from Nanocor Inc. so far except the cited Eastman patent in the relevant scientific and Patent Literature are described or claimed.

Loud the cited Eastman patent is at low addition levels on organo-nano-layer silicates is despite increased Barrier effect in the SSP process stage surprisingly good Nachkondensationsgeschwindigkeit achieved.

Yu, Hui-min; Han, Keqing; Lu, da-guang; Yu, Mu-huo from Donghua University Shanghai, China [Xuebao (2004), 22 (4), 576-579] also observed a big Influence of the effect of pure sodium montmorillonite on SSP solid-phase condensation (SSP, especially on the crystallization rate, and write this the amplified Nucleating effect of the Nanoschichtsilikate, due to a increased Formation of microliths and greatly increased crystallite surface by the multitude of microlithe formed, too. These microliths are supposed to the diffusion rate of the liberated MEG in the SSP phase across from larger crystallites favor.

Ke, Yang-Chuan; Yang, Zhi-bin; Zhu, Chuan-Feng of the Polyolefin National Engineering Research Center, BRICI, Sinopec, China Journal of Applied Polymer Science (2002), 85 (13), 2677-269], interpreted this positive effect particularly as a direct effect of the interaction of the exfoliated phyllosilicate. Slats with the molecular chains of PET to a pronounced regular polymer chain pattern, which accelerates the rate of PET crystallization as such and influences the polyester morphology. (please refer 4 ).

The Japanese authors Imai, Yusuke; Inukai, Yoshinari; Tateyama, Hiroshi of the Institute for Structural and Engineering Materials, AIST, Saga, 841-0052, Japan [Polymer Journal (Tokyo, Japan) (2003), 35 (3), 230-235 ] used special quaternary phosphonium as an alternative thermostable organophilic nanosheet silicate in attempts to produce thermostable PET nanoclay composites by in-situ melt-phase condensation and subsequent SSP salts (dodecyltriphenylphosphonium bromide or 10- [3,5-bis (methoxycarbonyl) phenoxy] decyltriphenylphosphonium bromide), which, however, have no commercial exploitation prospects, since these phosphonium compounds are toxicologically very questionable, since phosphine compounds in the thermal decomposition of quaternary phosphonium salts according to the 5 led reaction scheme arise:
In addition, quaternary phosphonium compounds are very expensive, which is why they have not been considered further in the large-scale production of organophilic Nanoschichtsilikate.

Of the Content of the method according to the invention is a technology for in-situ polycondensation of innovative Nanocomposite structural materials made of polyethylene terephthalate (homo-PET or co-PET) as matrix polymers and organophilically modified, higher temperature resistant nanosheet silicate as nanodisperse amplification or barrier and UV-improving additive components. Such Nanocomposites are u a. For Polyamide 6 as a matrix (obtained via Melt compounding of nylon 6 base polymer or in situ polymerization from caprolactam to polyamide nanocomposites) has long been excellent known and used by some companies (Bayer AG, Honeywell, UBE Industries, RTP) already commercially available.

The technology of this invention is essentially aimed at improving both the gas barrier properties (O ₂ and CO ₂ ) by incorporating a higher temperature resistant organophilic nanoclay type (I24TL) with specific recipe adaptation to the specifics of the homo- or co-polyester condensation process to obtain the factor 2-5 to obtain a customer accepted transparency, crystallization rate and coloration of the packaging material and a reduction of the UV transmission rate in the wavelength range λ = 250-390 nm, as well as in the solid phase condensation of low-viscosity Polyesternanocompositen towards highly viscous Polyesternanocompositen a process-economic Acceleration SSP reaction by a factor of 2 to 3 compared to pure homo- or co-polyester to effect.

The result of the present invention is thus a new technology, in particular for the production of innovative Polyesternanocomposites based on polyethylene terephthalate nanocomposites (PET-NC) via the in-situ polymerization route of bis-hydroxyethylene terephthalate obtained by the DMT or PTA process using conventional polyester Starting materials (monoethylene glycol = MEG, diethylene glycol = DEG, isophthalic acid = IPA, pure terephthalic acid = PTA, cyclohexanedimethanol = CHDM and an additional thermostable organophilic additive based on the nanosheet silicate Nanomer I24TL, characterized in particular by an improved gas barrier (O ₂ - and CO ₂ permeation), an accelerated solid-phase post-condensation behavior and increased UV absorption.

Based on the in-situ polymerization technology for the production of new, innovative polyester base resins with significantly improved gas and UV barrier, according to this invention a new technology for obtaining co-polyester (PET) based nanocomposite materials via the established DMT or TPA process with in-situ incorporation of already commercially available and as loud as the FDA for food contact in polyamide nanocomposite packaging materials already approved organophilic, highly exfoliable montmorillonite (I24TL) described with high thermal stability and excellent polymer compatibility to the co-polyester which can be successfully established in the market. In particular, a maximum formation of the delaminated nanostructure of I24TL (exfoliation) during the technological process of in situ polymerization, the gas barrier and UV absorption behavior of the resulting PET-NC's should be significantly influenced and controlled. The exfoliated I24TL nanosheet silicate platelets introduced into the polyester matrix cause the formation of a microcrystalline and nanocrystallite structure, which in turn has an advantageous effect on the accelerated diffusion behavior of ethylene glycol in the solid-phase condensation of the polyester anocomposites according to the invention in SSP systems and thus shortened SSP residence times. As an evaluation criterion for the exfoliation quality of the I24TL nanosheet silicate in the polyester matrix, the shear thinning behavior of the obtained polyester anomie melt melt was determined according to the present invention, the steepness of the increase of the melt viscosity curve in said low shear range being a measure of the exfoliation quality. For in-situ PET nanocomposites with 3 wt.% Of I24TL obtained according to the invention, a shear thinning coefficient n ≧ | -0.5 | felt sufficient to achieve good to very good exfoliation of the I24TL nanosheet silicate platelets in the polyester matrix (see 6 to embodiment 2). At a content of 6 wt. An I24TL nanosheet silicate had a shear thinning coefficient n ≧ | -0.7 | Indication for a good to very good exfoliation. Organically unmodified sodium montmorillonite (Na-MMT) causes no exfoliation of the Nanoschichtsilikatplättchen in the polyester matrix, which is characterized by the extremely ge The increase in melt viscosity of an in-situ Na-MMT / PET nanocomposite in the above-mentioned low-shear abundance with n = -0.015 showed (see 7 to Comparative Example 6). Another criterion for the goodness of the exfoliation of the in-situ introduced nanosheet silicate platelets of I24TL into the polyester matrix is the wide-angle X-ray diffractometry / WAXS). As the I24TL nanosheet silicate platelets continue to exfoliate through in situ condensed polyester chains, which greatly expand the interlayer lattice spaces, the X-ray reflection peak typical for the I24TL additive disappears at 2 theta = 5.15 degrees (d-spacing value) in the obtained WAXS curves = 17.2 nm) more or less completely, during which the intensity of the X-ray radiation (Lin {counts) increases strongly in the angular range 2 theta <2.5 degrees. However, a newly formed X-ray reflection peak in the 2-theta range 6-7 degrees also indicates re-aggregated nanosheet silicate platelets to the montmorillonite lattice structure, which is due to thermal decomposition of organophilic Nanoschichtsilikaten the case. Pure sodium montmorillonite (Na-MMT) has an X-ray reflectance peak at 2 theta of about 8 degrees, depending on the residual moisture content of water. In-situ incorporated in PET Na-MMT is subject to 7 of Comparative Example 6 no exfoliation, only a slight intercalation occurs, which is reflected in the greatly widened X-ray reflectance peak of 2 theta = 6 to 8 degrees. According to the present invention, it has been found that in thermally unstable organophilic nanosheet silicates with quaternary ammonium salts as Organophilierungsreagenz as in the case of I34TCN (Nanocor Inc. additives) according to 8th to Comparative Example 1 due to thermal decomposition of the organophilicating component at the in-situ polycondensation conditions during polyestersanocomposite production, a clear MMT peak in the range of 2 theta = 5.2 to 7.0 occurs, the starting additive I34TCN exhibiting a sharp X-ray reflection peak at 2 theta = Shows 4.8 degrees.

In contrast, when using the inventive incorporation of organophilic nanosheet silicates with increased thermal stability, such as the additive I24TL from Nanocor Inc., only an extremely small amount of re-aggregated MMT nanosheet silicate platelets is obtained by thermal decomposition reactions, as in the WAXS curve of FIG 9 to Embodiment 2 on the basis of the low intensity of the d-spacing value of 14.91 Å can be seen.

The Invention has the production and application of a single-grade PET nanocomposite with excellent barrier to the content, which can be used without a second matrix polymer, in particular for use as a bottle raw material suitable. The corresponding recipe of additivation with a special Organophilic Nanoschichtsilikat is together with the engineering adapted large-scale PET polymerisation the inventor and in the field of engineering polyester condensation plants to obtain new, innovative polyester products (in particular Providing a single-grade PET barrier layer with at the same time increased UV absorption for the packaging sector and the beverage industry).

in the Unlike multilayer composites of several polymers or physically coated polyester barrier packaging allows one according to the present Invention conceived material a multiple material or chemical recycling while preserving the originally obtained mechanical and barrier properties with reasonable technical Effort. Montmorillonite as a natural phyllosilicate also shows no activity after organophilization with aminododecanoic acid toxic properties, so even higher incorporation levels in the polyester matrix should be safe, especially in the food-grade area for Foil and bottle packaging according to FDA regulation and consumer goods regulation is required by law.

More particularly, this invention relates to a process for obtaining polyester (homo-PET and Co-PET) types having improved manufacturing and service properties, which include, in particular, higher temperature resistant organophilic nanosheet silicates in the range of 0.01 to 20 wt%. Packaging materials obtained from these modified polyester anocomposites (films, bottles, etc.) exhibit a significant increase in the gas barrier behavior over O ₂ and CO ₂ by at least a factor of 2 to 5 and an increased UV barrier in the wavelength range of λ = 250-390 nm Special feature of the way of introducing a adapted for the elevated temperature conditions of the PET melt polycondensation and SSP post-condensation thermostable organophilic Nanoschichtsilikat additive of the present invention allows trouble-free flow of both the polyester in situ condensation, as well as the subsequent solid phase condensation without further above-described technological problems. The introduced, well-exfoliated Nanoschichtsilikate cause beyond influencing the crystallite sizes of the resulting Polyesternanocomposite towards micro- and nanocrystallites even an unexpected acceleration of the SSP Nachkondensationsgeschwindigkeit and reduce the UV transmission in the range of short wavelength light (λ = 300-390 nm) considerably , wherein nevertheless a good optical transparency in the visible wavelength range of λ = 390-780 nm is given.

According to the present invention, a thermally very stable organophilic nanosheet silicate type commercially available from Nanocor Inc. USA is used in the process of producing HOMO polyester or co-polyester as an additive in amounts of 0.01-20% by weight, preferably 0.5%. 10 wt%, during in-situ polymerization of bis-hydroxyethylene terephthalate monomer (BHET) to obtain polyesters of the invention having a high exfoliation rate of the nanosheet silicate platelets used in the polyester matrix. The nanosheet silicate type used is an I24TL nanomer commercially available from Nanocor Inc. based on sodium montmorillonite, which has been correspondingly organophilicly adjusted with aminododecanoic acid ADA) via an ion exchange ratio (CEC) of 125 .mu.g / 100 g. Due to the use of a primary ammonium salt of ADA in the form of Cl ^- / ⁺ H ₃ N - (CH ₂ ) ₁₁ -COOH in the nanosheet silicate additive is from the outset against such Nanoschichtsilikaten that have been organophilated with quaternary or tertiary ammonium compounds (see 10 and 11 ), given a much higher thermal stability (see 12 ). In order to take into account the excess of carboxyl groups additionally introduced by the organophilization reagent during the polyester in-situ condensation reaction, basic components such as KOH or NaOH or hexamethylenediamine in appropriate stoichiometric ratio are metered in together with the nanosheet silicate additive I24TL, depending on the amount of I24TL added. Without the necessary according to the invention use of KOH or NaOH or hexamethylenediamine to balance the introduced by ADA carboxyl excesses are co-polyesters with high molar proportions of diethylene glycol monomer (20-40 mol% depending on the degree of condensation of the bis-hydroxyethylene terephthalate monomers ) obtained in the polymer chain, which provide an unfavorably low for further processing into films or containers glass transition point in the range of 35-45 ° C and melting points in the range of 180-230 ° C. On the other hand, with stoichiometric balancing of the COOH excess with KOH, NaOH or hexamethylenediamine, a polyester with a low content of diethylene glycol (1-5 mol%) is obtained, which thus also results in in-situ production of diethylene glycol units in the attainment of copolyesters Based on DEG advantageous can be exploited without adding DEG additionally as an external co-monomer with. According to the invention, the I24TL monomer and KOH, or NaOH or hexamethylenediamine are obtained simultaneously with the molten bis-hydroxyethylene terephthalate monomer BHET obtained by the DMT process or after the TPA direct esterification process in the case of obtaining a Homo-Polyesternanocomposites or to a melt mixture consisting of To add BHET with co-monomers such as diethylene glycol, isophthalic acid and cyclohexanedimethanol to obtain co-polyesters. The addition of the Nanoschichtsilikatadditivs and KOH, or NaOH in the melt of BHET or BHET / Co monomers in the temperature range of 170-240 ° C is carried out either as a solid or hexamethylenediamine as a glycolic solution or an ethylene glycolic suspension consisting of nanomer I24TL and KOH (or NaOH or hexamethylenediamine) is previously prepared via a corresponding dispersing (Ultraturrax or wet ball mill). This particular I24TL glycol suspension can then also be fed to the BHET or BHET / Co monomer melt.

• – 3 Gew.% Zugabe I24TL-Nanomer: O₂-Barrierewert = 23 cm³/100 μm 24h × m² × bar
• – 6 Gew.% Zugabe I24TL- Nanomer: O₂-Barrierewert = 10 cm³/100 μm 24h × m² × bar.

(bei einem Referenzwert für die clayfreie Folienprobe von 40 cm³/100 μm 24h × m² × bar).According to the present invention, the following gas barrier values were determined in Examples 2 and 3 for selected in situ generated I24L / homo-PET polyester anocomposites:

• - 3 wt% addition I24TL-Nanomer: O ₂ -Barrierewert = 23 ^cm3 / 100 microns 24 m × ² × bar.
• - 6 wt% addition I24TL- Nanomer: O ₂ -Barrierewert = 10 ^cm3 / 100 microns 24 m × ² × bar..

(at a reference value for the clayfreie film sample of 40 ^cm3 / 100 microns x 24 m ² x bar).

13 provides a corresponding graphical overview of the obtained in the embodiments 2 and 3 oxygen barrier values in comparison with an additive-free polyester film and a polyester film filled only with 3 wt% sodium montmorillonite.

at The search of scientific and patent literature has been outside the previously cited Eastman patent WO 98/29499 no further Example of this found that e.g. the thermally much higher stable I24TL nanosheet silicate especially for in-situ PET polymerisation Obtaining PET nanocomposites with investigated or equivalent claims to that effect. Eastman waived its claims in said patent possible stoichiometric Balancing of the acidic pH produced by the aminododecanoic acid in the reaction melt, which are known to extremely high DEG levels (in Eastman Patent itself as such definitely mentioned), and thus greatly lowered Lead melting points of the polyester.

However, according to the present description of the invention, it is precisely the need for a stoichiometric balance of the excess of carboxyl end groups (COOH) introduced by the aminododecanoic acid of the I24TL nanomer - and the associated reduction in the pH in the polyester Melting - a major role, to which according to the present invention, the additional simultaneous addition of KOH, or NaOH or hexamethylenediamine is claimed.

moreover had Eastman in the in-situ melt condensation of PET monomers with ADA-modified MMT, but also with other organophilic nanosheet silicates, only low molecular weight, obtained in the melt phase polycondensation PET-NC precursor materials for a subsequent SSP reaction claims where at these process conditions (very short temperature residence times of about 30 minutes at <280 ° C jacket temperature, no information about the real product temperature, the simplest laboratory scale), the actual technological problems and process effects, as in first orienting in situ polycondensation experiments (Comparative Examples 1 and 2 of the present invention) with different organophilic nanosheet silicates based on quaternary ammonium salt compounds as such occurs, hardly or not at all in the specification mentioned. In the case of the embodiment (Example 21) of the o.g. Patent of Eastman with about 7 wt.% Addition ADA-MMT, however, provided the statement that at a final precursor viscosity of 0.45 dl / g at a max. Polycondensation temperature of only 265 ° C already over 11 mol% Analyzed DEG in PET-NC after the subsequent SSP reaction, the indirect indication that for the MMT additive related organophilicizing component ADA with the immanent COOH groups relevant the acid catalyzed DEG formation from MEG monomer in the melt and SSP process sustainable affected.

These Knowledge could be found in a few preliminary experiments in the Comparative Examples 3 and 4 of the present invention description approved be found where similar Addition levels to ADA-MMT (from commercial I24TL organo-nanoclay), but at higher, usual Melt polycondensation temperatures of 285 ° C and longer polycondensation times from about 2 h, already over 30 .... 40 mol% DEG were found in the PET nanocomposite, which is in a totally amorphous PET material with an IV around 0.60..0.62 dl / g without clear melting point with a glass point around 40-50 ° C resulted.

HOFFMANN-Abbau für quaternäre Ammoniumsalze According to Figure 11 of this invention, it can be seen that the relative weight loss of I24TL nanosheet silicate at 270 ° is only about 2% (corresponding to about 8% by weight of aminododecanoic acid relative to MMT) and at about 300 ° C. is only about 3% (corresponds about 12% by weight of aminododecanoic acid based on MMT). Since I24TL itself is only a primary ammonium salt {protonated aminododecanoic acid [HCL × H ₂ N- (CH ₂ ) ₁₁ -COOH]} organophilized MMT, it is no longer subject to thermally induced Hoffmann degradation, which is preferred for quaternary ammonium salts according to US Pat following scheme:

HOFFMANN degradation for quaternary ammonium salts

According to 12 even at a TGA temperature of 350 ° C only about 10 wt.% Total loss had been measured, which corresponds to about 45% cleavage of aminododecanoic acid based on MMT. The fact that the cleavage of the organophilization reagent from the nanosheet silicate (here in particular in the case of quaternary organic ammonium salts) that the nanoshillosilicate platelets initially precintercalated in the polymer melt at low temperatures reunite to a corresponding degree (layer expansion → layer aggregation), which is very well known in the art corresponding WAXS image of Comparative Example 1 (see 8th ) according to this invention, where again X-ray reflections can be found at the 2 theta normal for pure MMT by 6 degrees (corresponding to d-spacing values of 14-15 Å), as hitherto recognized by most authors in relevant scientific publications as such Appearance was similarly found in corresponding WAXS shots, but has not been interpreted to that effect.

When using the thermally higher stable Nanoschichtsilikates I24TL in the polyester matrix in the embodiments 2 and 3 was according to 9 found a much smaller regression of MMT layer assembly in an I24TL polyester anocomposite material in WAXS than was measured in the I34TCN polyesters anocomposites in Comparative Examples 1 and 2, respectively.

Out The literature and patent research was so initially apparent that so far mostly organophilic nanosheet silicates with quaternary ammonium salts based on long-chain alkyl groups (C14 ... C18) of the commercial Competitors or scientific research institutions which were at the high process temperatures in the in-situ polycondensation process for PET to a thermal decomposition of the organophilic Nanoschichtsilikate as a result of the o.g. HOFFMANN removal reaction led.

Here is cleaved from the quaternary ammonium salt of the organoclays, inter alia, the alkyl group as alkene ((in the example CH ₂ = CH- (CH _{2) 15} -CH _3]), where also additionally self-crosslinking may occur with increasing temperature, with or enter :

From thermogravimetric analyzes (TGA) it was found that the quaternary ammonium salt organophilization reagents of the nanosheet silicates used exhibited for the most part already at 200 ° C.... 230 ° C. the first thermal decomposition phenomena and at the process temperatures of 275-290 ° C. usual for the PET condensation process C very significant amounts of C14 ... C18 residues have been cleaved off (see 11 ).

The method according to the invention will be explained in more detail below with corresponding comparative examples and exemplary embodiments, but without being limited to these alone. The noted in the description of the invention noted 1 - 16 are attached to the sponsor's description.

Comparative Example 1

1320 g of bis-hydroxyethylene terephthalate monomer (obtained from prior transesterification of DMT with ethylene glycol) were melted in a 2I autoclave and upon reaching a product temperature of 190 ° C, the addition of 31 g (3 wt.%) Was carried out in a vacuum oven at 2 mbar and 100 ° C dried organophilic Nanoschichtsilikates I34TCN Nanocor Inc., 1.25 g H ₃ PO ₄ (10%, 39.5 ppm P based on polyester) and 1.839 g antimony triacetate (750 ppm Sb based on polyester). Excess ethylene glycol was distilled off in the subsequent precondensation with stirring until reaching a product temperature of 265 ° C. Thermal decomposition phenomena led to foaming of the polyester melt due to the release of gaseous decomposition products, resulting in a partial blockage of the vapor lines at the autoclave head.

at Applying the vacuum to carry out the polycondensation reaction increased with increasing polycondensation temperature increasingly the thermal decomposition of the used Nanoschichtsilikates. The released gaseous Decomposition products therefore only a vacuum of 20 maximum mbar at a product temperature of 280 ° C and 50 mbar at 285-288 ° C towards the end the polycondensation. After 70 minutes polycondensation time was a strong brown low molecular weight homo-polyester anocomposite with an IV of only 0.40 dl / g. Due to the low polymer viscosity was no APET cast film produced.

The WAXS image (see 8th ) revealed that at 6.25 Gad 2 theta (d-spacing = 14 nm), a peak again occurs at the point where the peak of Na-montmorillonite is otherwise, which speaks for the partial thermal decomposition of the I34TCN nanosheet silicate. In the shear thinning method of taking the yield curve in the low shear range (γ = 10 ^-2 ... 10 ⁰ ) of a cone-plate rotation viscometer, the shear thinning coefficient (n) = -0.30 was determined, indicating a weak exfoliation of the I34TCN in the polyester matrix speaks.

Comparative Example 2

528 g of an esterification product of terephthalic acid and ethylene glycol were introduced together with 222 g of terephthalic acid, 144 g of ethylene glycol and 12 g of isophthalic acid and 6.4 g of diethylene glycol as a co-monomer in a 2I autoclave and heated to a product temperature of 190 ° C with stirring heated. Subsequently, the addition of 24.7 g of dried in a vacuum oven at 2 mbar and 100 ° C organophilic Nanoschichtsilikates I34TCN the company Nanocor Inc. (3 wt.% Based on Polyester) and 1.839 g antimony triacetate (750 ppm Sb based on polyester). The product temperature was increased to 265 ° C to complete the esterification reaction. During this esterification phase in the presence of the nanosheet silicate I34TCN, a considerable foaming of the polymer melt already took place, which led to partial blockage of the vapor lines, which was further enhanced when the vacuum program for carrying out the polycondensation reaction was applied. Not least due to the thermal decomposition of the I34TCN nanosheet silicate with the release of gaseous decomposition products, only a maximum vacuum of 20 mbar was achieved. After 70 minutes of polycondensation time, a strong brown co-polyestersanocomposite with an IV of only 0.30 dl / g was obtained, which could not be further processed into films

Comparative Example 3

1320 g of bis-hydroxyethylene terephthalate monomer (obtained from the transesterification of DMT with ethylene glycol) were melted in a ₂ l autoclave and when a product temperature of 190 ° C. was reached, the addition of 1.25 g of N ₃ PO ₄ stabilizer (10%) was initially carried out. equals 39.5 ppm of phosphorus based on polyester), and after stirring for a further 10 minutes, the addition of 10.2 g (1% by weight) of the organophilic nanophile I24TL from Nanocor dried in a vacuum drying oven at 2 mbar and 100 ° C. Inc., as well as 1.839 g of antimony triacetate (750 ppm Sb based on polyester). Excess ethylene glycol was distilled off in the subsequent transesterification phase with stirring until reaching a product temperature of 265 ° C., the transesterification reaction thus continued without foaming of the melt. When creating the vacuum program, there were no problems, so that a final vacuum of 2 mbar at a product temperature of 286 ° C was easily achieved. After 115 minutes of polycondensation time, a co-polyestersanocomposite having an IV of 0.69 dl / g and a COOH end group number of 42 μequ / g of polyester was obtained. The color of the polyester melt was light brown. Strong odors of dioxane in the ethylene glycol reservoir with a very small amount of distilled ethylene glycol from the polycondensation, a glass transition point of only 49 ° C and a broad, flat melt peak at 181 ° C in the DSC had a very high DEG content of about 40 Mol% based on the total glycol content in the obtained Polyesternanocomposite out (see 14 ).

On Reason of the extremely low Glass transition point was already in the granulation a bonding of the resulting polyester chips inevitably occurred, resulting in subsequent granule drying to <100 ppm residual water moisture for film extrusion impossible made.

Comparative Example 4

The Procedure of Comparative Example 3 was repeated except that the added amount of the thermally stable in a vacuum oven at 2 mbar and 100 ° C dried organophilic nanosheet silicate I24TL to 31 g (3% by weight) based on polyester) increased has been.

Excess ethylene glycol was distilled off in the subsequent transesterification phase with stirring until reaching a product temperature of 265 ° C., the transesterification reaction thus proceeded again without foaming of the melt. When applying the vacuum program, there were no problems, so that a final vacuum of 2 mbar at a product temperature of 286 ° C was easily achieved. After 165 minutes of polycondensation time, a polyester anocomposite with an IV of 0.67 dl / g and a COOH end group number of 67 μeq / g of polyester was obtained. The color of the polyester melt was light brown. A lack of ethylene glycol distillate in the ethylene glycol receiver from the polycondensation reaction, a glass transition point of only 38 ° C, a lack of crystallization peak, and a broad, extremely flat melt peak at 135 ° C in the DSC had a very high DEG content of ≧ 78 mol% based on the Total glycol content in the obtained Polyesternanocomposite out (see 14 ).

On Reason of the extremely low Glass transition point was at the granulation an even stronger sticking of accumulating Polyester chips inevitably occurred, causing a subsequent Granule drying to <100 ppm residual water moisture for Film extrusion absolutely impossible

Comparative Example 5

1200 g of a bis-Hydroxyethylenterephthaltes with low free glycol content (melting point of 230 ° C) obtained from a precursor of the esterification of terephthalic acid with ethylene glycol were melted in the 2I autoclave. After reaching an internal product temperature of 250 ° C, only the polycondensation catalyst antimony-III-oxide with 0.36 g (250 ppm Sb based on polyester) were added. Excess glycol was distilled off until reaching a product temperature of 265 ° C and then applied vacuum. Upon reaching a polycondensation temperature of 288 ° C at a final vacuum of 2 mbar, a transparent polyester having an IV of 0.65 dl / g, a glass transition point of 75 ° C and a melt temperature of 263 ° C was obtained after 100 minutes polycondensation.

The granulated polyester chips were sufficiently dried and made an APET reference foil the Thickness 100 μm on a laboratory foil caster the company Göttfert cast.

The oxygen-Barrierertest with the gas permeation measuring Brugger gave an O ₂ permeability value of 40 ^cm3 / 100 microns x 24 h x bar.

Like in the 15 can be seen, the reference film thus obtained has a high UV transmission value of 90% in the wavelength range of 350 nm.

Comparative Example 6

1200 g of a bis-Hydroxyethylenterephthaltes with low free glycol content (melting point of 230 ° C) obtained from a precursor esterification of terephthalic acid with ethylene glycol were melted in the 2I autoclave and at a temperature of 235 ° C were now 31 g (3 wt % of polyester) dried in a vacuum oven at 2 mbar and 100 ° C Nanoschichtsilikattype PK-805 Paikong (Taiwan), consisting of pure, unmodified and white sodium montmorillonite, added with stirring in solid form. After reaching an internal product temperature of 250 ° C as a polycondensation catalyst 2.4 g of aluminum trihydrate (2000 ppm Al (OH) ₃ based on polyester) were added. Excess glycol was distilled off until reaching a product temperature of 265 ° C and then applied vacuum. There was no foaming of the polymer melt. Upon reaching a polycondensation temperature of 290 ° C at a final vacuum of 2 mbar after 150 minutes polycondensation a bright, transparent Polyesternanocomposite with an IV of 0.56 dl / g, a glass transition point of 74 ° C and a melt temperature of 260 ° C was obtained. The DEG content was 0.7% by weight and 2.1% by mol, respectively.

The granulated polyester chips were sufficiently dried and poured therefrom an APET film of thickness 100 .mu.m on a laboratory film casting of Göttfert. The oxygen-Barrierertest with the gas permeation measuring Brugger gave an O ₂ permeability value of 38.4 ^cm3 / 100 microns x 24 h x bar.

Both the WAXS image (X-ray reflex at 2 theta = 6.26 degrees and d-spacing = 14.1 nm, see 16 ) as well as the extremely low shear thinning coefficient (n) = -0.015 (see 7 ) affirm that the Paikong-PK 805 Na montmorillonite used did not cause any exfoliation of the silicate platelets within the polyester matrix.

Like in the 15 can be seen, the thus obtained polyester film still has a very high UV transmission value of 90% in the wavelength range of 350 nm comparable to that of the reference film of Comparative Example 5. Only at a wavelength of <325 nm does a strong reduction in UV transmission begin.

Embodiment 1

The Procedure of Comparative Example 4 was repeated to that effect, that immediately added amount after the addition of 31 g (3 wt.% based on polyester) of the vacuum oven at 2 mbar and 100 ° C dried thermally stable organophilic nanosheet silicate I24TL from Nanocor Inc. when reaching 190 ° C Product temperature now 3 g (0.17 mol) of hexamethylenediamine in Form an aqueous 70% solution additionally were added. Excess ethylene glycol was aborted until reaching a product temperature of 265 ° C. The distilled EG contained no hexamethylenediamine (indicator test & smell sample). Both in the transesterification phase, as well as in the condensation phase no foaming occurred the melt on and the vacuum program could go up without any problems be lowered to the final pressure of 2 mbar. After 118 minutes polycondensation time at a polycondensation temperature of 288 ° C became a light brown polyester with an IV of 0.62 dl / g and a COOH end group number of 67 μeqv / g polyester obtained. In the DSC in the 1st heating a glass transition point of 69 ° C, a crystallization point of 123 ° C and a melt peak at 239 ° C discovered. This corresponds to a DEG content of about 4.5% by weight. or 13.5 mol%.

From no cast foils were made in this polyester batch.

Embodiment 2:

The procedure of the embodiment 1 was modified only to the effect that immediately after the addition of 31 g (3 wt.% Based on polyester) of dried in a vacuum oven at 2 mbar and 100 ° C thermally stable organophilic Nanoschichtsilikates I24TL Nanocor Inc. upon reaching 190 ° C product temperature 1.95 g of solid potassium hydroxide (34.6 mmol) were additionally added. Excess ethylene glycol was expelled until reaching a product temperature of 265 ° C. Both in the transesterification phase and in the condensation phase, no melting of the melt occurred and the vacuum program could be lowered without problems to the final pressure of 2 mbar. After 120 minutes of polycondensation at a polycondensation temperature of 288 ° C, a light brown, transparent polyester having an IV of 0.66 dl / g and a COOH end group number of 31 μeqv / g of polyester was obtained. In the first heating, a glass transition point of 71 ° C., a crystallization point of 125 ° C. and a melt peak at 248 ° C. were found in the DSC. This corresponds to a DEG content of about 3 wt.% Or 9 mol%. The shear thinning coefficient (n) as a measure of the very good exfoliation of the I24TL nanosheet silicate in the polyester matrix was γ = 10 ^-2 ... 10 ⁰ in the low shear range, correspondingly (n) = -0.55 (see 6 ).

The granulated polyester chips were sufficiently dried and poured therefrom an APET film of thickness 100 .mu.m on a laboratory film casting of Göttfert. The oxygen-Barrierertest with the gas permeation measuring Brugger gave an O ₂ permeability value of 23 ^cm3 / 100 microns x 24 h x bar.

As As can be seen in Figure 15, the obtained film still has a strong lowered UV transmission in the wavelength range of 350 nm with 30% residual transmission compared 90% of a comparable polyester reference film without Nanoschichtsilikat (Comparative Example 5).

Solid-phase condensation tests at temperatures of 225 and 230 ° C in a vacuum oven at a pressure of 1 mbar resulted in a shortening the SSP residence time by a factor of 2.5 to an intrinsic viscosity of 0.90 to obtain dl / g.

Embodiment 3

1000 g of a bis-Hydroxyethylenterephthaltes with low content of free Glycol (melting point of 230 ° C) obtained from a precursor of the esterification of terephthalic acid Ethylene glycol was melted in the 2 l autoclave. After reaching a product internal temperature of 250 ° C were both 65 g I24TL of Nanocor Inc. as well as 4.09 g KOH each in solid form in the polyester melt stirred. Subsequently was used as a polycondensation catalyst antimony-III acetate in the amount of 1.839 g (750 ppm Sb based on polyester) were added. Excess glycol was distilled off until reaching a product temperature of 265 ° C. and subsequently Vacuum applied. Upon reaching a polycondensation temperature from 288 ° C at a final vacuum of 2 mbar was after 120 minutes polycondensation time a light brown, transparent polyester with an IV of 0.61 dl / g, a COOH end group number of 41 μeqv / g Polyester, and in DSC at the 1st heating a glass transition point of 75.6 ° C, a crystallization point of 120 ° C and a melting temperature peak of 252 ° C attained. This corresponds to one DEG content of about 2 wt.% Or 6 mol%.

The shear thinning coefficient (n) as a measure of the very good exfoliation of the I24TL nanosheet silicate in the polyester matrix was γ = 10 ^-2 ... 10 ⁰ in the low shear range, correspondingly (n) = -0.60.

The granulated polyester chips were sufficiently dried and made an APET film of thickness 100 μm on a laboratory foil caster the company Göttfert cast.

The oxygen-Barrierertest with the gas permeation measuring Brugger gave an O ₂ permeability value of 10 ^cm3 / 100 microns x 24 h x bar.

As in 15 can be seen, the obtained film further has a greatly reduced UV transmission in the wavelength range of 350 nm with 15% residual transmission compared to 90% of a comparable polyester reference film without Nanoschichtsilikat (Comparative Example 5).

Solid-phase condensation tests at temperatures of 225 and 230 ° C in a vacuum oven at a pressure of 1 mbar resulted in a shortening the SSP residence time by a factor of 2 to achieve an intrinsic viscosity of 0.90 dl / g.

Embodiment 4

1000 g of a bis-Hydroxyethylenterephthaltes (BHET) with low free glycol content (melting point of 230 ° C) obtained from a precursor of the esterification of terephthalic acid with ethylene glycol were melted in the 2I autoclave. After reaching an internal product temperature of 230 ° C, 100 g of a preheated to 100 ° C ethylene glycol suspension containing 31 g in a vacuum oven at 2 mbar and 100 ° C dried I24TL Nanoschichtsilikates, 0.98 g of antimony III acetate (= 500 ppm Antimony) as a polycondensation catalyst and 1.95 g KOH, introduced into the autoclave via a metering lock in the BHET melt. The suspension components were previously shattered extensively in ethylene glycol by means of a rubbing ball mill at a temperature of 50-60 ° C. The pH of the sheared suspension was 6.9 and the particle size distribution determined by means of a HORIBA Capa 700 particle centrifuge gave a D ₅₀ value of 3 μm, with no particles> 10 μm. In the WAXS spectrum of this suspension, a layer widening of the nanomer I24TL to d = 30 nm was measured. The suspension was sedimentation stable for several hours. (A similarly prepared suspension, but without the addition of KOH as the stoichiometric balance of excess COOH groups, gave a pH of 5.60).

Excess glycol was distilled off until reaching a product temperature of 265 ° C. and subsequently Vacuum applied. Upon reaching a polycondensation temperature from 288 ° C at a final vacuum of 2 mbar was after 125 minutes polycondensation time a light brown, transparent polyester with an IV of 0.64 dl / g, a COOH end group number of 40 μeqv / g Polyester, and in DSC at the 1st heating a glass transition point of 76 ° C, a crystallization point of 121 ° C and a melt temperature peak of 255 ° C. This corresponds to one DEG content of about 1.8 wt% or about 5 mol%.

The shear thinning coefficient (n) as a measure of the very good exfoliation of the I24TL nanosheet silicate in the polyester matrix was γ = 10 ^-2 ... 10 ⁰ in the low-shear range, correspondingly (n) = -0.65.

The granulated polyester chips were sufficiently dried and made an APET film of thickness 100 μm on a laboratory foil caster the company Göttfert cast.

The oxygen-Barrierertest with the gas Permeation Brugger gave an O ₂ permeability value of 20 ^cm3 / 100 microns x 24 h x bar.

The film obtained therefrom furthermore exhibited a greatly reduced UV transmission in the wavelength range of 350 nm with 30% residual transmission compared to 90% of a comparable polyester reference film without nanosheet silicate (cf. 16 to Comparative Example 5).

Solid-phase condensation tests at temperatures of 225 ° C and 230 ° C in a vacuum oven at a pressure of 1 mbar resulted in a shortening the SSP residence time by a factor of 2 to an intrinsic viscosity of 0.92 to obtain dl / g.

Claims (19)

A process for the production of polyester anocomposites for the subsequent further processing into corresponding packaging films or packaging containers, characterized in that 0.01 to 20 wt.% Of a thermally stable organophilic Nanoschichtsilikats and thereto equimolar amounts of basic additives during the in-situ melt-phase polycondensation in a suitable Thus, depending on the addition amount of nanosheet silicate compared to unmodified polyesters, the barrier values for the permeation of oxygen and carbon dioxide by a factor of 2 to 5, a significant reduction in the transmission of UV radiation in the Wavelength range of λ = 300-390 nm and have an acceleration of the solid phase condensation. Method according to claim 1, characterized in that that the composition of the polyester anocomposite is a thermal up to 290 ° C sufficiently thermally resistant contains organophilic Nanoschichtsilikat, which of a chemically modified natural Bentonite is derived. Method according to claim 1, characterized in that that the composition of the polyester anocomposites is between 80 and 99.99% by weight of polyester and 0.01-20% by weight of thermally stable organophilic nanosheet silicate and in particular between 90 and 99.5% by weight of polyester and 0.5-10 Weight of thermally stable organophilic Nanoschichtsilikat. Process according to Claims 1 and 3, characterized that for the preparation of the polyester anocomposites used thermally stable organophilic nanosheet silicate a modified with aminododecanoic acid Sodium montmorillonite, which is 90-150 μequv of aminododecanoic acid, is preferred 120-130 μequv of aminododecanoic acid, based to 100 g of sodium montmorillonite. Process according to claims 1, 3 and 4, characterized that for the preparation of the polyester anocomposites immediately after addition of thermally stable organophilic Nanoschichtsilikates in the Polyester melt in addition KOH, NaOH or hexamethylenediamine in the stoichiometric amounts of 50 to 120 mol%, preferably 95 to 100 mol%, with respect to the molar amount of on the thermostable nanosheet silicate-incorporated aminododecanoic acid equivalent, is added. Method according to claim 1, characterized in that that over the melt phase polycondensation obtained polyester anocomposites in the subsequent solid phase condensation (SSP) a reduction of the Residence time in the SSP condensation by a factor of 2 to 3 compared to pure Polyester effect. Process according to Claims 1 and 4, characterized that the obtained Polyesternanocomposite in the range of short-wave Light of 300nm-390 nm at a content of 3-6 % By weight of said thermally stable organophilic nanosheet silicate a reduction in UV transmission over unmodified polyester by at least 60%. Process according to Claims 1, 4 and 5, characterized that for the preparation of the polyester anocomposite the addition of the thermal stable organophilic Nanoschichtsilikates and of KOH or NaOH or hexamethylenediamine in the form of the pure additives in the melt of bis-hydroxyalkylene terephthalate, preferably in the temperature range from 230 to 250 ° C he follows. Process according to Claims 1, 4 and 5, characterized that for the preparation of the polyester anocomposite the addition of the thermal stable organophilic Nanoschichtsilikates preferably in the form of a ethylene glycol suspension with the addition of KOH or NaOH or Hexamethylenediamine in the melt of bis-hydroxyalkylene terephthalate, preferred in the temperature range from 230 to 250 ° C, via a metering lock. Process according to claims 1, 4, 5 and 9, characterized marked that for the production of the polyester anocomposites used ethylene glycolic Suspension consisting of the additive components thermally stable organophilic nanosheet silicate, KOH or NaOH or hexamethylenediamine and the antimony catalyst in a Reibkugelmühle intense is subjected to shear dispersion. Process according to Claims 1, 4, 5, 9 and 10, characterized in that the ethylene glycolic suspension used for the production of the polyester anocomposites consisting of the additive components thermally stable organophilic Nanoschichtsilikat, KOH or NaOH or hexamethylenediamine and the antimony catalyst has a pH of 6.5-7.5, preferably 6.8-7.2, and has a D ₅₀ value of <5 μm, preferably <3 μm, and no large particles> 15 μm, preferably> 10 μm, more in the suspension are included. Process according to claims 1, 4, 5, 9, 10 and 11, characterized in that for the production of the polyester anocomposites used ethylene glycolic suspension consisting of the additive components thermally stable organophilic nanosheet silicate, KOH or NaOH or hexamethylenediamine and the antimony catalyst over at least 3 hours sedimentation stable. Method according to claim 1, characterized in that that for the preparation of the polyester anocomposite is preferred as the catalyst Antimony in the form of antimony triacetate or antimony-III-oxide in the range the addition amount of 150-1000 ppm, preferably 250-750 ppm is used. A method according to claim 1, characterized in that for the production of antimony-free Polyesternanocomposite aluminum trihydrate in the range of addition amount of 100 to 5000 ppm Al (OH) ₃ , preferably 1000-3000 ppm Al (OH) ₃ , is used, which in the form of an ethylene glycolic suspension together thermally stable organophilic Nanoschichtsilikat, KOH or NaOH or hexamethylenediamine is introduced into the melt of bis-hydroxyalkylene terephthalate, preferably in the temperature range of 230 to 250 ° C, via a metering lock with the additive components. Method according to claim 1, characterized in that that for the production of said polyester anocomposite as the acid component at least 50 mol% of a dibasic acid or of the corresponding dimethyl ester, selected from the group consisting of terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and respective mixtures thereof and at least one glycol component, selected from a group of glycols containing between 2 and 10 carbon atoms own, are used. Process according to Claims 1 and 15, characterized that up to 50 mol% of a second acid component or more dibasic acid components which are selected from aromatic dicarboxylic acids having 8 to 14 carbon atoms, from aliphatic dicarboxylic acids with 4 to 12 carbon atoms and from cycloaliphatic dicarboxylic acids with 8 to 12 carbon atoms can exist. Process according to Claims 1 and 16, characterized that the dibasic acid components used from the group terephthalic acid, phthalic acid, isophthalic acid, 1,4-, 1,5-, 2,6-, and 2,7-naphthalene dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid and corresponding mixtures thereof. Process according to claims 1 and 15, characterized that said glycol component is selected from the group those of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, cyclohexanedimethanol, diethylene glycol and corresponding mixtures thereof. Process according to Claims 1, 6 and 7, characterized that the obtained polyester anocomposites are outstanding for Further processing to transparent polyester films and polyester bottles according to the established Processing technologies are suitable.