WO2007071577A1

WO2007071577A1 - Method for plasticising soft polyvinyl chloride

Info

Publication number: WO2007071577A1
Application number: PCT/EP2006/069510
Authority: WO
Inventors: Jürgen Holzmann; Boris Breitscheidel; Klaus Rossato
Original assignee: Basf Aktiengesellschaft
Priority date: 2005-12-19
Filing date: 2006-12-11
Publication date: 2007-06-28
Also published as: DE102005061030A1

Abstract

The invention relates to a method for plastifying soft polyvinyl chloride by extruding polyvinyl chloride dry blends containing a softener composition comprising at least one C8-C10 phthalic acid dialkyl ester softener and additives, by means of an extrusion device. According to said method, a polyvinyl chloride dry blend is used, said blend containing a softener composition comprising bis-(2-propylheptyl)-phthalic acid diester and having higher slip and bulk density than a polyvinyl chloride dry blend of the same polyvinyl chloride type and with the same content and composition of additives and the same content of at least one softener containing C8-C10 phthalic acid dialkyl ester of a composition which does not contain bis-(2-propylheptyl)-phthalic acid diester. The extrusion device is operated in such a way as to obtain a homogeneously plasticised extrudate and to adjust a mass temperature of the plasticised polyvinyl chloride dry blend in the outlet region of the extrusion device, which is between 10 and 20 °C beneath the decomposition temperature of the plasticised polyvinyl chloride dry blend.

Description

Process for plasticizing soft polyvinyl chloride

description

The present invention relates to a process for plasticizing soft polyvinyl chloride by extruding dry polyvinyl chloride mixtures containing at least one plasticizer and additives by means of an extruding device.

Polyvinyl chloride ( "PVC") is one of the quantitatively most produced plastics. Without plasticizer PVC is one to about 8O ⁰ C hard, brittle plastic, which used with thermal stabilizers and other additives as rigid PVC or PVC-U for example, window profiles, pipes Plasticizers are also added to the PVC for many applications, which make the PVC soft, flexible, supple and elastic depending on the amount of plasticizer added Depending on its plasticizer content, a distinction is made between rigid PVC and soft PVC generally has a plasticizer content of 0 to about 3 wt .-%, with plasticized PVC, the plasticizer content is generally 20 to 50 wt .-%.

A wide variety of plasticizers for softening PVC are available on the market. Due to their good compatibility with the PVC and their advantageous performance properties generally plasticizers are used from phthalic diesters with Cs to Cio alcohols of different chemical structure. Di-2-ethylhexyl phthalate (abbreviation: DEHP or DOP), di-isononyl phthalate (DINP), prepared from nonanol mixtures which are formed by the dimerization of butenes to form octene mixtures, are currently from this group of Cs to Cio phthalates for example, by means of oligomerization catalysts based on nickel oxide (for example WO 95/014674) or by means of acidic oligomerization catalysts, such as zeolites or phosphoric acid applied to an inorganic support material (eg US 5,895,830, US 5,081,086), and their subsequent hydroformylation and hydrogenation, and di-isodecyl phthalate (DIDP), prepared from decanol mixtures obtained by the hydroformylation and subsequent hydrogenation of trimer derivatives, the most economically important plasticizers. Phthalates of shorter-chain alcohols, for example dibutyl phthalates, are mainly used for special applications, for example as "fast fusers" in the plastisol production or in combination with Cs to Cio phthalates for lowering the dissolution temperature in the plasticization of the Because of their high volatility, these short-chain phthalates are rarely used outside of these special applications, as are the phthalates of longer-chain alcohols containing more than 12 carbon atoms, as the length of the alkyl chain decreases the miscibility and compatibility of the plasticizer with the PVC may cause the plasticizer to exude from the PVC over time. The Cs to Cio dialkyl esters of aliphatic dicarboxylic acids, such as adipic acid, sebacic acid or azelaic acid, are used.

For the production of soft PVC, the pure PVC, as it comes from the polymerization, must generally be softened in the form of a powder. The softening process is not trivial due to the complex solid state structure of the PVC and its unusual theological behavior, and is accomplished over several stages. First, the PVC powder at temperatures up to about 8O ⁰ C mechanically, for example in fluid mixers, turbomixers, tray mixers or ribbon screw mixers, mixed with the plasticizer, wherein the plasticizer penetrates adhesively into the cavities of the PVC grain. With increasing mixing temperature - up to about 14O ⁰ C - the plasticizer is absorbed and adsorbed in the cavities of the primary particles of which the PVC grain is composed. At this stage, the PVC-plasticizer mixture still has the nature of a dry powder, which is why one speaks of PVC-T rockenmischungen or PVC-dry blends.

Only on further heating to temperatures of about 155 to about 165 ⁰ C, the plasticizer is intermolecularly intercalated between the molecular associates of the PVC chains. This involves pre-gelation of the PVC combined with agglomeration of the powder particles and incipient plastification of the PVC. As a result of agglomeration and incipient plasticization, the PVC plasticizer mixture becomes rubbery, cakes and is virtually no longer satisfactorily processed in conventional mechanical mixers or kneaders, which is why these and the final stage of softening - complete gelling and plasticizing of the PVC with the plasticizer Plasticizer under frictional pressure in the range of the optimum gelling temperature of the plasticizer used, which is generally in the range of about 165 to about 200 ⁰ C - be carried out in an extruding. The homogeneously plasticized PVC obtained in the last stage of the softening process is generally pressed at the end of the extruder through an extrusion die, eg a perforated disc, comminuted into granules or strands by means of a cutter, eg a rotating knife, and cooled in water. The granules or strands thus obtained are used as starting material for the production of PVC finished products, for example by injection molding, extrusion or extrusion blown film.

As a rule, the PVC, together with the incorporation of the plasticizer, also requires the auxiliaries and additives needed to achieve the desired processing and technical properties, for example lubricants, stabilizers, fillers, flame retardants and / or pigments. One speaks in this case also of compounding the PVC. For plasticizing in an extrusion device, for example single- or twin-screw extruder, co-kneader or planetary roller extruder, the powdery, free-flowing PVC T rockenmischung is abandoned in the catchment area of the screw, transported by the rotational movement of the screw toward the exit of the extruding, thereby compacted and through due to the rotational movement of the screw between the webs of the screw and the screw cylinder occurring shear forces and friction heated, homogenized and plasticized. Finally, in the discharge zone of the extruding device, the plasticized and homogenized PVC rock mixture is obtained in a molten, viscous state, which is finally pressed through an extrusion die. As can already be seen from the reference to the compaction of the PVC-T rockenmischung, a considerable pressure is built up in the course of the processes described in the extruding, by certain geometrical configurations of the screw, for example, a reduction in the depth of the flight between the webs of the screw or Built-ins, such as sieve packages, can be additionally forced. The plasticizing processes described above by way of example for a single-screw extruder likewise run off in other extruding devices, wherein in the case of twin-screw or multi-screw extruders, the additional shearing and frictional effects of the intermeshing screws must be taken into account.

In order to carry out the plastification of PVC rock mixtures into plasticized PVC in an economically efficient manner, the extruding device used is generally operated at the maximum possible output of extrudate or throughput of PVC rock mixture. This can be achieved by increasing the volume of PVC-T rockenmischung supplied to the extruding device in accordance with the capacity of the extruding device, this measure being assisted by increasing the screw speed, in each case on condition that the energy input into the PVC Mixture through the extruder is sufficiently large to ensure the desired plasticization and homogenization of the PVC blend mixture.

Such an approach, however, are limited insofar as the increased promotion of PVC rockenmischung, possibly supported by an increase in the screw speed with an increase in the load of the screw, detectable example, by the determination of the torque is connected. This increase in load is due to an increase in the shear and worm cylinder shear forces caused by the increase in the volume of PVC tow delivered and the friction which also causes an increase in the frictional heat generated in the extruder. If it is not counteracted or counteracted by suitable measures, this increase in frictional heat can be so strong that the melt temperature of the plasticized PVC mixture in the extruder device is its decomposition temperature and an unusable or severely degraded product is extruded.

In order to prevent exceeding the melt temperature of the plasticized PVC mixture in the extrusion device, either the throughput of PVC

It is possible to limit dry mixing by the extruder at the expense of extruding the extrudate, or one can try to keep the melt temperature of the plasticized PVC mixture below the decomposition temperature of the PVC mixture by means of thermostating devices, for example cooling devices, which are normally present in the extruder. With the lowering of the melt temperature, the viscosity of the plasticized PVC mixture increases, which may result in an unrelenting supply of PVC rocker mixture to such a strong pressure build-up in the extruder that the emergency shutdown of the extruder is triggered or pressure damage to the extruder can occur both associated with longer downtime of the expensive extruding device.

Increasing the output of plasticized PVC by increasing the volume of PVC T rocking mixture fed to an extruder is therefore virtually systemic.

PVC is a bulk plastic of e.g. produced in 2000 in a capacity of 25 million tonnes worldwide. Accordingly, the price of a PVC product plays a crucial role in its marketability. Cost savings in PVC production and processing are therefore highly relevant to the competitiveness of a producer.

In view of the relatively expensive processes required for softening and compounding PVC, it is an object of the present invention to improve the economics of the softening and compounding process. In particular, it should be possible to increase the productivity of the extruding devices present in a plasticizing plasticised plastic plant, without adversely affecting the quality of the plasticized plasticized PVC.

Accordingly, a process has been found for plasticizing soft polyvinyl chloride by extruding dry polyvinyl chloride blends containing a softening composition having at least one C 8 to C 10 phthalic acid plasticizer and additives, by means of an extruding apparatus characterized in that a Polyvinyl chloride dry blend containing a bis (2-propylheptyl) -phthalthalate-containing softening composition, and whose lubricity and bulk density relative to the lubricity and bulk density of a polyvinyl chloride dry blend of the same chen polyvinyl chloride type and with the same content and composition of additives and with the same content of at least one Cs to Cio-dialkyl phthalate containing plasticizer of a composition containing no bis (2-propylheptyl) -Phthalsäurediester, is increased and the extruder is operated to obtain a homogenously plasticized extrudate and to set a melt temperature of the plasticized polyvinyl chloride dry blend in the discharge zone of the extruder which is 10 to 20 ° C below the decomposition temperature of the plasticized polyvinyl chloride dry blend.

The use of bis (2-propylheptyl) phthalic acid ester as plasticizer for PVC is known. For example, US Pat. No. 292,1089 describes the preparation of bis (2-propylheptyl) -phthalic acid diesters and their use as plasticizers for PVC for the first time.

US Pat. No. 4,426,542 discloses the preparation of 2-propylheptanol isomer mixtures by the hydroformylation of butenes, followed by a crossed aldol condensation of the resulting n- / iso-valeraldehyde mixture to form a 2-propylheptenal isomer mixture and its subsequent hydrogenation. The 2-propyl-heptanol isomer mixtures thus prepared are esterified to give the corresponding phthalic diesters which serve as plasticizers.

EP-A 366089 also relates to the preparation of certain 2-propylheptanol isomer mixtures and their use for the preparation of the corresponding phthalic acid plasticizers for PVC, likewise WO 05/028404 and WO 05/028407.

Other publications such as JP 4 104 740, JP 4 106 132, JP 4 105 145, JP 4 106 146, JP 4 299 924, JP 4 258 641, JP 5 194 761, JP 5 194 810, JP 5 214 159, JP 5 214 192, JP 5 339 388, JP 6 002 281, JP 6 001 858, JP 6 001 862, JP 6 001 900, JP 6 001 901, JP 7 157 615, JP 7 173 356, JP 7 179 699, JP 8 034 891, JP 8 059 937, JP 8 283 510, JP 8 157 422, JP 8 301 295, JP 7 304 920, JP 7 304 921 and JP 8 003 401 deal with various advantageous properties of bis (2 propylheptyl) - phthalic acid diester plasticized PVC products.

The abovementioned publications do not contain any information on the processing behavior of bis (2-propylheptyl) phthalic diester ("DPHP") in the plasticization of PVC.

Despite its advantageous properties, bis (2-propylheptyl) -phthalic diester, compared with other Cs to Cio-dialkyl phthalates, such as DOP, DINP or DIDP, which are used as standard plasticizers, has so far only a relatively small extent in the plasticizer market which may be due, among other things, to the limited commercial availability up to a few years ago. It should be noted in this It should be noted that the term "bis (2-propylheptyl) phthalic acid diester" in the context of the present application includes both the pure substance bis- (2-propylheptyl) -phthalates and mixtures thereof with the phthalic diesters of 2-propylheptanol -lsomeren as they are raw material and production conditional in industrially produced bis (2-propylheptyl) -Phtalsäuresiester present.

It has now surprisingly been found that PVC T rocken mixtures containing bis (2-propylheptyl) -phthalates have a higher bulk density than PVC T rockenmischungen the same polyvinyl chloride type with the same content and the same composition of additives and with the same content a plasticizer composition containing at least one Cs to Cio-dialkyl phthalate which does not contain bis (2-propylheptyl) -phthalic diester.

Due to the higher bulk density DPHP-containing PVC T rock mixtures have a lower bulk volume than compositionally comparable PVC T rockenmischungen containing instead of DPHP another Cs to Cio-Phthalsäuredialkylester as a plasticizer. This means that a given extruder with a given volume capacity for the material to be extruded - in the present case the PVC-T rockenmischung - can be loaded with a larger mass of PVC T rockenmischung, whereby the ejection of the extruder to plasticized PVC without an increase in speed can be increased.

In further studies on the plasticization of DPHP in place of other Cs to Cio-dialkyl phthalates as plasticizer-containing PVC T rockenmischungen in an extruding was surprisingly found that despite the feed of the same volume of PVC-T rockenmischung - ie at one opposite comparable but instead of DPHP another Cs to Cio-dialkyl phthalate containing PVC T rockenmischung increased amount of weight - and at the same screw speed, the measured torque of the screw, so their load, not as expected increased, but a lower Had value.

The reduced load of the extruder also became apparent from the fact that the melt temperature of the thus plasticized DPHP-containing PVC blend in the extruder was equal to or lower than the comparable PVC blends containing DP, Cs to Cio dialkyl phthalate instead of DPHP and this in spite of the higher bulk density by weight higher throughput of PVC T rockenmischung by the extruder.

It is evident that this phenomenon is a synergistic effect brought about by the use of DPHP, which makes it possible to control the speed of the screw in the extruder and thus the ejection of the extruder to increase to a greater extent than is possible due to the higher bulk density of the DPHP-containing PVC-T rocking mixture and without adversely affecting the quality of the plasticized PVC extrudate until it reaches the desired melt temperature range for plasticization. Compliance with the quality requirements is on the one hand ensured by the fact that caused by the increased bulk density of the DPHP-containing PVC T rockenmischung increase in the delivery rate of the extruder contrary to expectations does not necessarily increase the melt temperature of the PVC mixture in the extruder into the area or by exceeding the decomposition temperature and, on the other hand, by the melting and mixing of the PVC mixture required for homogeneous plasticization by adjusting the required melt temperature in addition to other suitable measures, eg heating the intake area of the extruder, by a corresponding increase the screw speed can be effected without exceeding the desired melt temperature range.

This synergistic effect is attributed to the fact that the use of DPHP as a plasticizer appears to additionally increase the intrinsic lubricity of the PVC blend. The inherent lubricity is understood to mean the lubricity of the PVC mixture without the addition of auxiliaries used to increase lubricity, which are also referred to as lubricants.

In addition to the above-mentioned beneficial effects in the softening and / or compounding of PVC rock mixtures, the increased lubricity of DPHP-containing PVC blends may also be beneficial in the downstream processing stages of plasticizing, for example, in injection molding, extrusion, and blown film extrusion PVC. Apart from that, due to the increased lubricity of the DPHP-containing PVC, the addition of other lubricants to the PVC-T rock mixture can be reduced or, in some cases, even completely undermined.

In accordance with the foregoing, another aspect of the present invention comprises the use of bis (2-propylheptyl) -phthalic acid diesters to increase the bulk density of polyvinyl chloride dry blends.

Another aspect of the present invention involves the use of bis (2-propylheptyl) phthalic diesters to increase the lubricity of polyvinyl chloride dry blends in their plasticization.

The inventive method relates to the plasticization of soft polyvinyl chloride ("soft PVC") by extruding a PVC T rockenmischung with a plasticizer composition, the DPHP and optionally other auxiliaries and optionally containing additives, by means of an extruding device. The term plasticization as used in connection with the process according to the invention thus encompasses the plasticization of PVC as well as the compounding of PVC, provided the softening and compounding are carried out concurrently with each other or overlapping in time. Under softening in this context, the mechanical treatment of the plasticizer-containing PVC T rockenmischung at temperatures above 140 ° C in an extruder under intermolecular, macroscopically homogeneous incorporation of the plasticizer molecules between the polymer chains of the PVC - this process is also referred to as gelation - and education understood in its macroscopic consistency compared to the plasticizer-free PVC soft and flexible soft PVC. On the other hand, compounding relates to the production of a generally largely homogeneous mixture of PVC with additives, including adjuvants intended to improve the processability and to impart the performance characteristics of the plasticized PVC required for the intended use. Auxiliaries for improving the processability of the PVC are, for example, lubricants which reduce the frictional resistance of the PVC, for example during extrusion, or stabilizers which increase the thermostability of the PVC in the individual processing steps. Examples of conventional additives for adjusting the desired performance properties include fillers for influencing mechanical behavior, light stabilizers, antistatics, flame retardants and pigments.

It is understood in view of the large number of possible different additives and the range of variation in the amount in which they can be mixed, of course, that the type and amount of the admixed additives have a significant impact on the theological and processing properties of PVC as well as its decomposition temperature and accordingly suitable processing conditions for the individual PVC compositions, eg Extrusion conditions, depending on the available processing devices and their mode of action are to be determined in detail in preliminary tests.

Equally diverse are the types of extruding devices which can be used in the method according to the invention and the geometries of the extruding and / or kneading screws used therein. In general, it should be noted that the usable

Extrusion devices based on their design principle for extruding powdery raw materials, such as the PVC rock mixtures, are said to be suitable and capable of plasticizing and at least macroscopically homogenizing the relevant PVC rock mixture. "To homogenize macroscopically" in this context means that in general no microscopically completely homogeneous extrudate has to be produced by the extruding device, since the soft PVC granules produced according to the invention generally have NEN subsequently further processing processes are subjected, for example, injection molding, extrusion or Folienblasextrudieren, which naturally cause a further homogenization of the extrudate and thus ensure a satisfactory product quality, on the other hand, the extrudate from the plasticization should no longer discernible with the naked eye inhomogeneities, eg non-gelled PVC - Granules or undispersed pigment agglomerates, since such coarse inhomogeneities of the extrudate from the plasticization, in the subsequent processing operations are no longer resolved and lead to products of reduced quality. The prerequisite for obtaining such a homogeneously plasticized extrudate is the melting of the PVC-T rockenmischung and the intensive mixing of the molten PVC mixture in the compression and discharge zone of the extruding device concerned. The melting results from the energy introduced into the PVC dry mixture, for example by the extruder screw via shear and friction forces and by compression of the dry mixture per unit time, possibly assisted by additional heating of the extrusion cylinder. The shear forces acting in the case of a single-screw extruder between the screw flight and the extruder cylinder simultaneously cause homogenization of the molten PVC rock mixture. The energy which can be introduced by the extruding device into the PVC-T mixture for melting and homogenizing it-that is, the performance of the extruding device-is apparatus-specific and represents the type of extruding device, its specific construction features, the geometry of the screw used-an extruding device usually a set of extruding screws of different geometry with different extrusion characteristics available - depending. By contrast, the energy required to melt and homogenize a PVC rock mixture depends on its composition. Accordingly, in order to obtain a homogeneously plasticized PVC extrudate, the extrusion apparatus is to be selected and operated or, for example, by the installation of suitable extruding screws designed such that over the formed of the compression zone and the Austragszone the extruding device, the required for melting and homogenization Energy can be entered into the PVC mixture. This is possible by means of routine preliminary tests.

The setting of the machine-specific parameters to obtain a homogeneously plasticized soft PVC mixture is thus a prerequisite for the successful implementation of the method according to the invention, but not the subject of the method according to the invention. Accordingly, in the process according to the invention all extruding devices suitable for plasticizing by extrusion of pulverulent PVC rock mixtures can be used, for example single-screw extruders, twin-screw extruders, co-kneaders or planetary roller extruders. Single or twin-screw extruders, preferably with forced feeding of the PVC-T rocking mixture, are particularly preferred for the process according to the invention. used. Advantageously, devices, eg vacuum pumps, which allow degassing of the plasticized PVC mixture, are attached to the extruding devices. To promote the degassing of the plasticized PVC trapped in the PVC dry blend of air and liquid, such as adsorbed water, advantageously specially shaped screws are used with a degassing zone. Usually, the extruding devices used in the method according to the invention include heating and cooling devices, for example in the form of heating sleeves or bands and cooling air ducts in the extrusion cylinder, which make it possible to regulate the melt temperature of the PVC contained in the extruder to a limited extent. The term extruding cylinder is used according to the conventional usage for the pressure body of the extruder, in which the recess for receiving the screw or screws is, whether this is cylindrical - as in the case of the single screw extruder - or not - as in the case of twin screw or multi-screw extruders.

The screws of these extruders may have a length to diameter ratio of generally 10/1 to 40/1, preferably 20/1 to 30/1, and more preferably 23/1 to 27/1. The compression ratio of the extruder screws, which is essentially a consequence of their geometric shape and e.g. due to the changes in flight depth, pitch and / or land width over the length of the screw, which cause compaction of the PVC rock mixture, and thus the ratio of flight volume in single screw extruders or chamber volumes in two or more screw extruders in the intake zone in the discharge zone of the extruding device may generally be 2/1 to 5/1, preferably 2.5 / 1 to 3.5 / 1 and especially 2.8 / 1 to 3.2 / 1.

According to the invention, a PVC mixture is used as the starting material for plasticizing soft PVC which has been treated with a plasticizer composition containing bis (2-propylheptyl) -phthal diester ("DPHP") as a plasticizer and whose bulk density relative to the bulk density a PVC dry blend of the same polyvinyl chloride type and having the same content and composition of additives and having the same content of a softener composition containing at least one C 8 to C 10 phthalic acid ester which does not contain DPHP The DPHP-containing plasticizer composition which was incorporated into the PVC-T rockenmischung to be used according to the invention in the first two stages of the softening process - as described above - may consist entirely of DPHP, but it may also contain other plasticizers in addition to the DPHP, for example di-undecyl phthalate or di-isotridecyl-PHth Preferably, the DPHP-containing plasticizer composition consists solely of DPHP. The plasticizers di-undecyl-phthalate or di-isotridecyl-phthalate are isomer mixtures which are obtained from the esterification of phthalic anhydride with a complex mixture of isomeric undecanols prepared, for example, by the hydroformylation and subsequent hydrogenation of decenes, eg can be produced by the Alfol process or by the Fischer-Tropsch process, or isomeric tridecanols - prepared, for example, by the hydroformylation of trimerbutene or tetramerpropylene and subsequent hydrogenation - come.

DPHP can be used as a defined compound - prepared by the aldol condensation of n-valeraldehyde, hydrogenation of the 2-propylheptenal formed and subsequent esterification of 2-propylheptanol with phthalic anhydride - in general, however, it is also present as a mixture of isomers, in the esterification of phthalic anhydride is formed with a mixture of 2-propylheptanol as the main component and 2-propylheptanol isomers. These 2-propylheptanol isomers are formed in the course of 2-propylheptanol production in different and varying composition depending on the composition of the starting material used in the step of hydroformylation to valeraldehyde butene mixtures. These butene mixtures-also referred to as raffinate I and raffinate II-contain, in addition to 1-butene and 2-butene, larger (raffinate I) or smaller amounts (raffinate II) of isobutene. Depending on the type of catalyst and process used for the hydroformylation, the individual olefinic components of the butene mixture are reacted at different rates and with different n / i ratios to form mixtures of isomeric valeraldehydes, which are subsequently subjected to crossed AlCl.sub.4 condensation and finally to a 2-propylheptanol isomer mixture be hydrogenated.

As starting material for the preparation of 2-propylheptanol, various hydrocarbon sources can be used, for example 1-butene, 2-butene, raffinate I - an alkane / alkene mixture obtained from the C4 cut of a cracker after separation of acetylene and dienes - And 2-butene still contains significant amounts of isobutene - or raffinate II, which is obtained from raffinate I by complete or extensive separation of isobutene and contains as olefin components except 1- and 2-butene no or only small amounts of isobutene. Of course, mixtures of raffinate I and raffinate II can be used as a raw material for 2-propylheptanol production. These olefins or olefin mixtures can be hydroformylated by conventional methods using known cobalt or rhodium catalysts, with 1-butene comprising a mixture of n- and isovaleraldehyde-the term iso-valeraldehyde designating in this application the compound 2- Methylbutanal - is formed, the n / iso ratio may vary depending on the catalyst used and hydroformylation within relatively wide limits. For example, when using a triphenylphosphine-modified homogeneous rhodium catalyst (Rh / TPP) from 1 -butene n- and iso-valeraldehyde in an n / iso ratio of generally 10: 1 to 20: 1, whereas when using with phosphite ligands, for example according to EP-A 155 508 or EP-A 213 639, or of phosphoamidite Ligands, for example, according to WO 02/83695, modified rhodium hydroformylation almost exclusively n-valeraldehyde is formed. While the Rh / TPP catalyst system reacts 2-butene only very slowly in the hydroformylation, so that most of the 2-butene can be recovered from the hydroformylation mixture, the hydroformylation of the 2-butene with the mentioned phosphite ligand succeeds - or phosphoramidite ligand-modified rhodium catalysts, wherein predominantly n-valeraldehyde is formed. On the other hand, isobutene contained in the olefinic raw material is hydroformylated, albeit at a different rate, from virtually all catalyst systems to 3-methylbutanal and depending on the catalyst to a lesser extent to pivalaldehyde.

The Cs aldehydes, depending on the starting materials and catalysts used, i. If desired, n-valeraldehyde in admixture with isovaleraldehyde, 3-methylbutanal and / or pivalaldehyde can, if desired, be separated completely or partially by distillation into the individual components before the aldol condensation, so that there is also a possibility of the isomeric composition of the C 10 -alcohol component to influence and control the ester mixtures according to the invention. Likewise, it is possible to add the Cs-aldehyde mixture as formed in the hydroformylation to the aldol condensation without prior separation of individual isomers. In the aldol condensation, which can be carried out by means of a basic catalyst such as sodium or potassium hydroxide, for example by the processes described in EP-A 366 089, US Pat. No. 4,426,524 or US Pat. No. 5,434,313, n is formed -Valeraldehyd as the only condensation product 2-propylheptenal, whereas when using a mixture of isomeric Cs-aldehydes, a mixture of isomers of the products of Homoaldolkondensation same aldehyde molecules and the crossed aldol condensation of different isomers is formed. Of course, the aldol condensation can be controlled by the targeted implementation of individual isomers so that predominantly or completely a single Aldolkondensationsisomer is formed. The aldol condensation products in question can then be hydrogenated, usually after prior, preferably distillative removal from the reaction mixture and, if desired, purification by distillation, with conventional hydrogenation catalysts to give the corresponding alcohols or alcohol mixtures.

The resulting alcohol mixture containing 2-propylheptanol as the main component and one or more of its isomers 2-propyl-4-methyl-hexanol, 2-propyl-5-methyl-hexanol, 2-isopropyl-heptanol, 2-isopropyl-4-methyl hexanol, 2-isopropyl-5-methyl-hexanol and / or 2-propyl-4,4-dimethylpentanol can, with phthalic anhydride in general under Brönsted or Lewis acid catalysis, but also autocatalytically be esterified. The resulting mixture of isomeric phthalic diesters is subsumed within the scope of this application under the name bis (2-propyl-heptyl) -phthalic acid diester or the abbreviation DPHP. The abovementioned isomers of 2-propylheptanol are referred to as "propylheptanol isomers" in the context of this application and for distinguishing between other isomeric C 10 alcohols, for example those which are part of the DIDP prepared from trimer propylene.

Suitable mixtures of 2-propylheptanol with propylheptanol isomers as may be used to prepare DPHP include e.g. and without this enumeration having a limiting character, such

a) 60 to 98 wt .-% of 2-propylheptanol, 1 to 15 wt .-% of 2-propyl-4-methyl-hexanol and 0.01 to 20 wt .-% of 2-propyl-5-methyl-hexanol and 0 , 01 to 24% by weight of 2-isopropylheptanol;

b) from 75 to 95% by weight of 2-propylheptanol, from 2 to 15% by weight of 2-propyl-4-methylhexanol, from 1 to 20% by weight of 2-propyl-5-methylhexanol, 0.1 to 4% by weight of 2-isopropylheptanol, 0.1 to 2% by weight of 2-isopropyl-4-methylhexanol and 0.1 to 2% by weight of 2-isopropyl-5-methylhexanol;

c) from 85 to 95% by weight of 2-propylheptanol, from 6 to 12% by weight of 2-propyl-4-methylhexanol and from 0.1 to 2% by weight of 2-propyl-5-methylhexanol and 0.01 to 1% by weight of 2-isopropylheptanol; or

d) 80 to 92% by weight of 2-propylheptanol, 6 to 12% by weight of 2-propyl-4-methylhexanol, 7 to 13% by weight of 2-propyl-5-methylhexanol, 0.1 to 2% by weight of 2-isopropylheptanol, 0.1 to 1% by weight of 2-isopropyl-4-methylhexanol and 0.1 to 1% by weight of 2-isopropyl-5-methylhexanol;

in each case the sum of the individual constituents does not exceed 100% by weight. Preferably, the proportions of the individual components add up to 100 wt .-%.

The PVC used for the production of the inventively applicable PVC T rockenmischungen may have been produced in various ways, for example by suspension polymerization, microsuspension, emulsion or bulk polymerization of the monomer vinyl chloride. The K value, which characterizes the molar mass of the PVC and is determined according to DIN 53726, can be in the range from 57 to 90, preferably in the range from 61 to 85 and particularly preferably in the range from 64 to 75 for PVC types used according to the invention. A review of the properties, production and use of PVC, which also includes the relationship between the K value, the number average molecular weight, the weight average molecular weight and the intrinsic viscosity measured according to ASTM L 1234. pensions and relative viscosity of the PVC is found in Kirk-Othmer, Encyclopaedia of Chemical Technology, 4th Ed., Vol. 24, pp. 1017-1047.

The inventively employable PVC T rockenmischungen PVC contents of generally 20 to 96 wt .-%, preferably from 30 to 90 wt .-%, particularly preferably from 35 to 80 wt .-% and in particular from 40 to 75 wt. -%, in each case based on the total weight of the PVC T rockenmischung, ie including all components of PVC-T rockenmischung, have.

The content of the inventively employable PVC T rockenmischungen DPHP - stated in phr - may generally be 20 to 100 phr, preferably 30 to 80 phr and more preferably 40 to 70 phr. The formulation recipe "phr" common for polymer compositions is the abbreviation for "parts per hundred resin" and means that additives are not weighed, measured and reported in terms of their percentage in the total mass, but as parts by weight per 100 parts by weight of polymer. If, for example, the ester mixture according to the invention is present in the PVC / plasticizer mixture in the weight ratio PVC: plasticizer of 80:20, the content of ester mixture is 25 phr, since 20 parts make up 25% of 80 parts.

When a softening composition containing other plasticizers other than DPHP, for example di-isotridecyl phthalate, is used for the production of soft PVC PVC rock mixtures, the DPHP content in the plasticizer composition is generally from 20 to 90% by weight, preferably from 30 to 70 wt .-%, in particular 50 to 70 wt .-%, so that after incorporation of this

Plasticizer composition in the PVC, the DPHP content in the PVC T rocken mixture is generally 4 to 90 phr, preferably 6 to 70 phr and more preferably 10 to 50 phr, each based on the weight of the PVC.

The DPHP-containing, usable according to the invention PVC T rockenmischungen have a higher bulk density than comparable PVC T rockenmischungen the same polyvinyl chloride type with the same content and same composition of additives and the same content of at least one Cs to Cio-Phthalsialkylester one Composition containing no DPHP. In other words and in simple terms, the PVC used in accordance with the invention

Dry blends a higher bulk density than PVC T rockenmischungen in which instead of DPHP the same amount of another Cs to Cio-phthalic acid dialkyl ester plasticizer is included, but otherwise have the same composition as the inventively applicable PVC T rockenmischungen. The bulk density of the PVC rock mixture is determined according to the method of DIN EN ISO 60 (January 2000 edition). The extent of increase in the bulk density of the DPHP-containing PVC rock mixtures to be used according to the invention with respect to comparable DPHP-containing PVC rock mixtures is essentially independent of the mixing temperature used in the production of the PVC rock mixtures.

For example, in a series of investigations it was found that the difference in bulk density of a DPHP-containing PVC coating mixture compared to comparable PVC dry mixtures containing DINP or DIDP plasticizers instead of DPHP exceeds the PVC blends used in the production of individual PVC rock mixtures. applied range of mixing temperature of 90 to 130 ° C - production of each DryBIends at 5 ° C intervals of the applied mixing temperature - practically remains the same. If the bulk densities measured for the DPHP-, DINP- or DIDP-containing PVC dry mixtures are plotted against the mixture temperature during their production, then three practically parallel curves are obtained.

The auxiliaries and additives required for the processing and application properties of the flexible PVC can be added to the PVC powder before it is plasticized in mechanical mixers. The admixture of the additives in the PVC can be done prior to or in conjunction with the production of PVC T rockenmischung. In this case, in the case of admixing solid additives, a pulverulent mixture is formed, in which PVC and additive particles coexist in largely homogeneous distribution. A homogeneous distribution of the auxiliaries and additives within the PVC mass is generally achieved only by the mechanical incorporation and distribution of the additives in the molten PVC. Accordingly, the compounding - ie the mixing in of the auxiliaries and additives - and the softening of the PVC are usually carried out in conjunction with one another or overlapping in time in the course of PVC plasticization.

In the plastification of a PVC-T rock mixture to be used according to the invention, the ejection of the extruding device to homogeneously plasticized

Extrudate in comparison to the output of a comparable, non-inventively to be used PVC T rockenmischung and comparable operating conditions of the extruder used, such as speed, temperature profile of the Extrudierzy- Linders and, as a result, the melt temperature of the PVC mixture, depending on the selected operating conditions 2 to more than 30% can be increased. In order to achieve a nearly maximum increase in productivity, the melt temperature of the plasticized soft PVC in the discharge zone of the extruder is adjusted so that it is about 10 to 20 ° C, preferably 10 to 15 ° C, below the decomposition temperature of the plasticized soft PVC mixture is. The melt temperature of the plasticized PVC can be measured with conventional temperature measuring devices, such as thermocouples. To avoid disturbances in the extruding device and increased wear of the temperature measuring device this can preferably be attached to the outlet of the extruding device before the plasticized soft PVC passes the extrusion die, eg a perforated disc. In principle, it is also possible to set the melt temperature in the discharge zone of the extruding device so that it is, for example, 1 to 10 ° C. below the decomposition temperature of the plasticized plasticized PVC. However, since depending on the design and operation of the extruding the maximum of the melt temperature further back, so further inside the extruding, can be achieved, there is the possibility that the decomposition temperature is exceeded.

The decomposition temperature of the plasticized soft PVC mixture is, of course, dependent on its composition or the composition of the PVC rock mixture to be plasticized. The decomposition temperature corresponds to the melt temperature of the plasticized PVC at which the induction time for the beginning of the decomposition of the PVC is equal to the residence time of the PVC in the compression and discharge zone of the extruder. In order to determine the decomposition temperature for the PVC composition to be plasticized, according to DIN 53381, first the induction time is determined, which is required until the hydrogen chloride gas released by thermal decomposition of the PVC sample at a certain temperature causes a change in the pH or the electrical conductivity of an aqueous solution Absorption solution causes. This measurement can be repeated at different temperatures to give a curve from which it can be read how long the induction time until onset of thermal decomposition of a PVC composition at a certain temperature. Alternatively, this curve can be calculated using the proportionality equation given in DIN 53381.

Knowing the decomposition temperature of the present invention to be used dry PVC blends at the time required to pass the compression and Austragszone of the extruder used can according to the invention the throughput of PVC T rockenmischung by or the output of plasticized PVC from the extruding device using the DPHP -mediated higher bulk density of the PVC-T rockenmischung and higher lubricity of the PVC can be maximized. As a result of the lower bulk volume due to the higher bulk density, more mass of PVC mixture can be metered into the working volume provided by the feed zone of the extruder, so that the working volume of the extruder can be optimally utilized. For this purpose, it may be advantageous to supply the PVC-T rockenmischung the feed zone of the extruding device via a forced metering, for example by the use of a metering screw. In the context of the structural conditions of the available extruding the speed of the screw of the extruding device is increased to achieve a maximum output of plasticized PVC so far that due to the thereby increased shear and friction, the melt temperature of the plasticized PVC T rockenmischung by 10 to 20 ° C. , preferably 10 to 15 ° C below the Zerset- tion temperature of the PVC mixture is. The increased shear of the compressed PVC rock mixture due to the increased rotational speed leads to greater mixing and homogenization as well as faster plasticization of the PVC mixture and to a shortening of the passage of the extrusion device, in particular its compression and discharge zone. time required, whereby the output of plasticized PVC can be additionally increased beyond that caused by the increased mass addition addition. The operating conditions of the available extruding device to be set for an individual PVC dry mixture can be determined by taking into account the teaching according to the invention on the basis of fewer simple preliminary tests.

The abovementioned measures can also be supported by the application of a temperature profile over the length of the extruder screw by means of thermostating devices present in or on the extruding cylinder. When setting the temperature profile, of course, the decomposition temperature of the PVC mixture to be plasticized must be taken into account. Accordingly, the input zone of the extruding device can be thermostated to a temperature in the range of, for example, 100 ° C, preferably in the range of 130 ° C and more preferably in the range of 150 ° C. In the region of the discharge zone, if necessary, the extrusion cylinder is thermostated to a temperature which is generally about 10 to 20 ° C below the decomposition temperature of the relevant PVC mixture.

The production of the inventively applicable PVC T rockenmischungen, with or without additives, can be done in a conventional manner, for example, as in Becker / Braun, Plastics Handbook, Volume 2/1 polyvinyl chloride, 2nd edition, Chapter 6.7 .1.5, Hanser, Munich 1986 for the production of dry blends of PVC and plasticizer and in Becker / Braun, Plastics Handbook, Volume 2/2 polyvinyl chloride, Chapter 7.2.4.1, Hanser, Munich 1986 described. If solid additives are to be mixed into the starting PVC powder, the PVC powder can generally be used first in mechanical mixers such as ribbon screw mixers, tray mixers, fluid mixers, turbomixers or planetary mixers with the solid additives and then with the liquid plasticizer and, if appropriate, liquid to be added In order to obtain a "dry" feeler powder, ie the dry blend, the addition sequence given above is not mandatory and can be varied.The mixing can be carried out at speeds of generally 500 to 5000 , preferably 1000 to 3000 and in particular 1500 to 2500 revolutions per minute, whereby the temperature of the mixture increases by frictional heat By controlling the mixer speed, it is possible the temperature of the PVC mixture in the mixer to generally 105 to 15O ⁰ C and preferably to 1 10 to 14O ⁰ C e toggle between having. The PVC-T rockenmischung thus produced can directly the Extrudiervoπϊchtung supplied for plasticization or previously cooled, for example, to room temperature.

The inventively employable PVC T rockenmischungen so may consist solely of PVC and a DPHP-containing plasticizer composition or additionally contain one or more auxiliaries and / or additives, such as stabilizers, lubricants, fillers, pigments, flame retardants, impact modifiers, optical brighteners, antistatic agents , UV and / or biostabilizers, this list being merely exemplary and not exhaustive.

Merely for the purpose of explaining the inventively applicable dry PVC mixtures, some of such additives and their function are described below by way of example, without these statements having a restrictive effect with respect to the invention to be used PVC T rockenmischungen.

Stabilizers, for example, neutralize the hydrochloric acid split off from PVC during and / or after processing, or counteract PVC degradation as free-radical scavengers.

Suitable stabilizers are all customary stabilizers in solid and liquid form, for example customary Ca / Zn, Ba / Zn, Pb or Sn stabilizers and also acid-binding phyllosilicates such as hydrotalcite. Preference is given to Ba / Zn stabilizers, tribasic lead sulfate (3 PbO ^* PbSO ₄ ^* H ₂ O) and lead phosphite, particularly preferably tribasic lead sulfate and lead phosphite. Radical scavengers exemplified dibutyltin maleate.

The inventively employable PVC T rockenmischungen may have a content of stabilizers from 0.05 to 7 phr, preferably 0.1 to 5 phr and more preferably from 0.2 to 4 phr.

Lubricants are said to act between PVC particles and the hot machine parts during processing, and to counteract frictional forces associated with mixing, plasticizing and deforming.

As a lubricant, the PVC-T rockenmischungen to be used according to the invention may contain all the lubricants customary for the processing of PVC. For example, come hydrocarbons such as oils, paraffins and polyethylene waxes, fatty acid salts, fatty alcohols having 10 to 20 carbon atoms, ketones, carboxylic acids such as fatty acids and montanic acid, oxidized polyethylene wax, metal salts of carboxylic acids, carboxylic acid amides and carboxylic acid esters, for example with the alco- get ethanol, fatty alcohols, glycerol, ethanediol, pentaerythritol and long-chain carboxylic acids as the acid component.

The PVC rock mixtures to be used according to the invention may have a lubricant content of from 0.01 to 10 phr, preferably from 0.05 to 5 phr and more preferably from 0.1 to 3 phr.

In particular, fillers have a positive influence on the compressive, tensile and flexural strength as well as the hardness and heat resistance of plasticized polyvinyl chloride.

Fillers, for example inorganic fillers, such as natural calcium carbonates, for example chalk, limestone and marble, synthetic calcium carbonates, dolomite, silicates, silicic acid, sand, diatomaceous earth, aluminum silicates, such as kaolin, mica and latex, can be added to the PVC rock mixtures to be used according to the invention become. Preferably used as fillers are calcium carbonates, chalk, dolomite, kaolin, silicates or talc, particularly preferably chalk or calcite.

The mixtures to be used according to the invention may have a content of fillers of from 0.01 to 100 phr and preferably from 1 to 80 phr.

The PVC-T rockenmischungen to be used according to the invention can also contain pigments in order to adapt the product obtained to different possible uses.

Both inorganic pigments and organic pigments can be used for this purpose. As inorganic pigments, for example, titanium pigments such as TiO 2, cobalt pigments such as COO / Al 2 O 3, and chromium (III) pigments such as Cr 2 O 3 may be used. Suitable organic pigments are, for example, condensed azo pigments, azomethine pigments, anthraquinone pigments, quinacridones, phthalocyanine pigments, dioxazine pigments, for example Cl. Pigment Violet 23 and aniline black (CI Pigment Black 1) into consideration.

The PVC rock mixtures to be used according to the invention may have a content of pigments of from 0.01 to 10 phr, preferably from 0.05 to 5 phr, more preferably from 0.1 to 3 phr and in particular from 0.5 to 2 phr ,

In order to reduce the flammability and to reduce the smoke during combustion, flame inhibitors may also be added to the PVC-T rock mixtures to be used according to the invention. For example, antimony trioxide, phosphoric acid esters, chloroparaffin, aluminum hydroxide, boron compounds, molybdenum trioxide or ferrocene can be used as flame retardants. Preference is given to using antimony trioxide or phosphoric acid esters, particularly preferably phosphoric esters, in particular bisphenyl cresyl phosphate, diphenyl octyl phosphate or tricresyl phosphate.

The PVC rock mixtures to be used according to the invention may have a content of flame inhibitors of from 0.01 to 100 phr and preferably from 0.1 to 20 phr.

In order to protect articles made from the PVC rock mixtures according to the invention from damage in the surface region by the influence of light, light stabilizers can also be added to these PVC rock mixtures.

For example, hydroxybenzophenones, hydroxyphenylbenzotriazoles or cyanophenyl acrylates can be used for this purpose. Cyanophenyl acrylates are preferred, more preferably 2-ethylhexyl-2-cyano-3,3-diphenylacrylate.

The PVC rock mixtures to be used according to the invention may comprise light stabilizers in an amount of from 0.01 to 7 phr, preferably from 0.1 to 5 phr and more preferably from 0.2 to 1 phr.

The plasticized plasticized PVC according to the invention can be further processed into PVC finished products such as cables, hoses or profiles by conventional methods such as injection molding, blown film extrusion or extrusion.

The following examples serve to illustrate the present invention.

Examples:

Example 1 (Inventive): Preparation of a PVC T rockenmischung

In a heating / cooling mixer of the turbocharger type FM 10 / KM 23 (manufacturer: Thyssen-Henschel), 100 g of Solvin® 271 SP type PVC (K value: 71, manufacturer: Solvin, Rheinberg) with 3 g (3 phr) tribasic lead sulphate (3 PbO x PbSO ₄ x H ₂ O) as a stabilizer, with 0.8 g (0.8 phr) of lead stearate (lead content: 28% by weight) as lubricant and with 80 g (80 phr) of calcite type Amolit ^® XO 10 (manufacturer: Alpha-calcite, Cologne) were mixed as a filler at a stirring speed of 2200 revolutions per minute to give a mixture temperature of 65 ° C was established. Subsequently, 55 g (55 phr) of DPHP prepared by the titanate-catalyzed esterification of phthalic anhydride with an alcohol mixture whose main components were normalized to this mixture to 100% to 89.49 wt .-% of 2-propylheptanol, to 10.47 wt .-% of 2-propyl-4-methylhexanol and to 0.04 wt .-% of 2-propyl-5-methylhexanol passed , Homogenized and the mixture at a stirring speed of 2000 revolutions per minute homogenized with friction-induced increase in temperature to a final value of 105 ° C, then cooled rapidly to 30 ° C and stored for four weeks at room temperature and with exclusion of moisture.

The PVC content of the dry mixture obtained was 41, 9 wt .-%, the DPHP content 23 wt .-% (55 phr), the content of tribasic lead sulfate 1, 3 wt .-% (3 phr), the content of Lead 0.3% by weight (0.8 phr) and calcite content 33.5% by weight (80 phr).

The bulk density of this PVC rock mixture was determined after 4 weeks of storage according to the method of DIN EN ISO 60, edition 01/2000, and was 0.657 g / cm ³ (average of 5 measurements).

Example 2 (comparison):

Example 1 was repeated with the same amounts of the individual components and under the same mixing conditions with the only difference that instead of the same amount of DPHP Jayflex DIDP ^® (manufacturer: Exxon) was used as a plasticizer. At the end of a 4-week storage period, the bulk density of the PVC dry mix obtained according to DIN EN ISO 60, edition 01/2000, was determined to be 0.636 g / cm ³ (average of 5 measurements).

Example 3 Production of a PVC Dry Mixture (Inventive)

In a heating / cooling mixer of the turbomixer type FM 10 / KM 23 (manufacturer: Thyssen-Henschel), 100 g of PVC of the type Vinoflex® S71 14 (K value: 71, manufacturer: Solvin, Rheinberg) with 3 g (3 phr) tribasic lead sulphate (3 PbO x PbSO ₄ x H ₂ O) as a stabilizer, with 0.8 g (0.8 phr) of lead stearate (lead content: 28% by weight) as lubricant and with 40 g (40 phr) of calcite mixed type Amolit ^® XO 10 as a filler at a stirring speed of 2200 revolutions per minute to give a mixture temperature of 65 ° C was established. Subsequently, 54 g (54 phr) of DPHP prepared by the titanate-catalyzed esterification of phthalic anhydride with an alcohol mixture whose main components, normalized to 100% to 89.49 wt .-% of 2-propylheptanol, to 10.47 wt % of 2-propyl-4-methylhexanol and 0.04 wt .-% of 2-propyl-5-methylhexanol passed, and the mixture at a stirring rate of 2000 revolutions per minute with friction-induced increase in temperature up to a Final value of 90 ° C homogeneous cooled, then quickly cooled to 30 ° C and stored for four weeks at room temperature and with exclusion of moisture.

The PVC content of the dry mixture obtained was 50.5 wt .-%, the DPHP content 27.4 wt .-% (54 phr), the content of tribasic lead sulfate 1, 5 wt .-% (3 phr), the Content of lead stearate 0.4% by weight (0.8 phr) and the content of calcite 20.2% by weight (40 phr).

The bulk density of this PVC rock mixture was determined after 4 weeks of storage according to the method of DIN EN ISO 60, edition 01/2000, and was 0.620 g / cm ³ (average of 5 measurements).

Example 4 (comparison):

Example 3 was repeated with the same amounts of the individual components and under the same mixing conditions with the only difference that instead of the same amount of DPHP Jayflex DIDP ^® (manufacturer: Exxon) was used as a plasticizer. At the end of the 4-week storage period, the bulk density of the resulting PVC dry mix according to DIN EN ISO 60, Edition 01/2000, was determined to be 0.596 g / cm ³ (average of 5 measurements).

Example 5: Plastification and Extrusion of the PVC Dry Mixture of Example 1

The PVC dry mix of Example 1 was plasticized and extruded with the aid of a "PolyLab System" laboratory screw extruder manufactured by Haake, equipped with a single screw having a length to diameter ratio of 25/1 and a compression ratio of 3 The extrusion die used a heatable round hole die with a hole diameter of 3 mm, the extrusion cylinder had three separately controllable heating zones, and a metering screw was used to feed the PVC dry mix into the feed zone of the extruder.

For plasticizing and extruding the PVC mixture, a temperature profile of 150 ° C. (feed zone) / 160 ° C. (compression zone) / 170 ° C. (round hole die) was created along the extruding cylinder. The PVC dry blend was introduced at a rotational speed of the screw feeder of 50 ^min-1 in the extruder, the screw was operated at a speed of 60 min-. ¹ A torque of 1 1, 7 Nm was measured. The melt temperature of the plasticized PVC mixture, measured by means of a thermocouple at the round hole die, was 176 ° C. A throughput of 3,494 kg / h PVC dry mix was achieved. Example 7 (comparison):

The PVC T rockenmischung from Example 2 was plasticized under the conditions given in Example 6 and extruded. It has a torque of 12 Nm measured, the bulk temperature of the plasticized PVC compound was 176 ⁰ C. It was obtained a rate of 3.245 kg / h PVC T-rock mixture.

The comparison of the results of Examples 6 and 7 demonstrates that under the specified conditions by the process according to the invention a 7.7% increased throughput of PVC T rockenmischung is achieved.

Example 8: Determination of the torque as a function of the output

It was prepared according to the procedure described in Example 1, the PVC T rock mix A, B and C of the following composition:

Blend A: DPHP: 54 phr; Lead stearate: 0.8 phr; Calcite: 40 phr; Naftovin ^® T3: 3 phr mixture B: DINP: 54 phr; Lead stearate: 0.8 phr; Calcite: 40 phr; Naftovin ^® T3: 3 phr mixture C: DIDP: 54 phr; Lead stearate: 0.8 phr; Calcite: 40 phr; Naftovin ^® T3: 3 phr

Naftovin T3 ^® : tribasic lead sulphate (manufacturer: Chemson)

The PVC rock mixtures were plasticized and extruded by means of a Rheocord 90 twin screw extruder (manufactured by Haake) with conical, counter-rotating screws at different speeds, and the extruder screw torque and output were measured. The results are summarized in the following table:

The table shows that at the speeds used for all three PVC dry blends practically the same output is achieved. However, the torque of the extruder screw measured under these conditions is significantly lower for the DPHP-containing PVC rock mixture than for the DINP or the DIDP-containing PVC-T rockenmischung. This effect is exacerbated by the application of industrially relevant higher speeds and is due to DPHP-mediated higher lubricity of the DPHP-containing blend.

In practical consequence this means that under the chosen conditions, in particular at higher screw speeds, the melt temperature of the DPHP-containing PVC mixture is at a lower value than e.g. in the case of the DIDP-containing PVC mixture. Taking into account the fact that a certain torque is not to be exceeded due to the device, and likewise a certain melt temperature of the PVC mixture in the extruder that depends on the composition of the PVC mixture (danger of decomposition), the DPHP-containing PVC Plasticized and extruded mixture at a higher screw speed than the comparable DINP or DIDP-containing PVC T rockenmischungen and increased in this way the output.

Claims

claims

1. A process for the plasticization of soft polyvinyl chloride by extruding dry polyvinyl chloride mixtures containing a plasticizer composition with at least one Cs to Cio-Phthalsäuredialkylester plasticizer and additives, by means of an extruding device, characterized in that a polyvinyl chloride dry mixture which contains a bis (2-propylheptyl) -phthalate containing plasticizer composition and its lubricity and bulk density in terms of lubricity and bulk density of a polyvinyl chloride dry blend of the same

Polyvinyl chloride-type and with the same content and composition of additives and with the same content of at least one Cs to C10-phthalate containing plasticizer of a composition containing no bis- (2-propylheptyl) -Pththalals increased, and the extruding under Obtaining a homogeneously plasticized extrudate and adjusting a melt temperature of the plasticized polyvinyl chloride dry blend in the discharge zone of the extruder, which is 10 to 20 ° C below the decomposition temperature of the plasticized polyvinyl chloride dry mixture operates.

2. The method according to claim 1, characterized in that the polyvinyl chloride dry mixture contains bis (2-propylheptyl) -Pththalsäurediester in a proportion of 20 to 100 phr.

3. The method according to claim 1, characterized in that one uses as Extrusi- onsvorrichtung a twin-screw extruder.

4. The method according to claim 1, characterized in that one uses as Extrusi- onsvorrichtung a single- or twin-screw extruder with forced feeding of the polyvinyl chloride dry mixture.

5. Use of bis (2-propylheptyl) phthalic acid diesters to increase the bulk density of polyvinyl chloride dry blends.

6. Use of bis (2-propylheptyl) -phthalates to increase the lubricity of polyvinyl chloride dry blends in their plasticization.