DE2105683A1 - Process for the production of poly propene masses in powder form - Google Patents

Description

" Process for the production of polypropene masses in

Powder form ^{! L}

The invention relates to a process for the production of polypropene compositions in powder form, which can be processed into products with improved impact resistance, and a predominantly isotactic propene polymer (polymer A) and a rubber-like ethene-propene copolymer (polymer B), which is optionally attached to the polymer A can be bound, contained, by

(A) polymerizing propene to a suspension of polymer A,

(b) Copolymerizing Athens and propene to give a suspension containing polymer B and

(c) Mixing the polymers A and B during or after the copolymerization (b),

working in the presence of a liquid diluent

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tet and this from the finished polymer suspension obtained is then removed.

A “predominantly isotactic propene polymer” is understood to mean a propene polymer which is more than 50 % crystallizable and cannot be extracted from n-beptane. In the first place, predominantly isotactic homopolymers of propene are meant, but the term also includes predominantly isotactic propene polymers, which are obtained in that the polymerization of propene has been carried out in the presence of at most and preferably less than 2 wt .-% Athens, which as Polymer A can act according to the invention.

In the compositions to be produced according to the invention, the Polymers A and B are present as separate unbound polymers. However, the two polymers can also be partially connected to each other. This can occur, for example, when the polymer B is in the presence of polymer A is produced, which is still active Contains catalyst.

It has been found that the polypropene in powder form mentioned type, which also has little or no tendency to Have adhesion, i.e. the powder has good flowability, can be obtained if the following five requirements are met during manufacture:

(1) The polymerization of propene to a suspension of the polymer A must be carried out with the aid of a catalyst system, which consists of an organometallic component C and a component D and by prior mixing of a dialkyl aluminum chloride Al (alkyl) ₂ Cl and titanium tetrachloride in a liquid paraffinic Diluents

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and with charging at a temperature below -5 ⁰ C, preferably between -5 and -45 ⁰ C, in particular between -10 and -40 ° C, in a molar ratio of 0.5 to 1.2, preferably from 0.65 to IjOO »where the ß-modification of titanium trichloride is formed and subsequent temperature increase of the mixture obtained to 70 to 200 ⁰ C has been produced with constant stirring (the ß-titanium trichloride is converted into the γ-modification);

(2) the viscosity number of polymer A, measured in decalin at 135 ° O, must be 1 to 4.5 dl / g;

(3) the polymer B must be 20 to 90 wt .-%, preferably 40 to 70% by weight, polymerized Athens contain, wherein a weight percentage of 50 to 65% by weight of Athens in particular is preferred;

(4) the final suspension must be the weight ratio between the polymer B and the sum of polymer A and polymer B 0.08 to 0.20, preferably 0.11 to 0.18 and particularly preferably 0.11 to 0.15; and

(5) the melt index of the finished mixture of polymer A and polymer B must be between 0.1 and 15.0, measured at 230 ° C according to British Standard 2782, Part I.

tr

By using the catalyst system described under (1) it is easy to add suspensions of polymer A. obtained which have a polymer concentration of 25 to 35 wt .-% and can still be stirred very well. This is an important advantage of the method according to the invention. Therefore, in the preparation of the suspension of Polymer A, the polymerization is preferably continued until a polymer concentration of more than 25 Wt .-% is reached, with a polymer concentration of 30 to 37% by weight in the suspension obtained as the end product is preferred before the removal of the diluent.

The weight ratio of polymer B to the sum of

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Polymer A and polymer B from 0.08 to 0.20 is preferably realized in that the production of Polymer B is carried out in the presence of a suspension of polymer A which still contains active catalyst. Such a process can be suitably carried out by the polymerization to the Polymer A and the copolymerization to polymer B is carried out continuously in separate reactors and the suspension obtained at the end of the preparation of polymer A and still active catalyst contains, is fed into the reactor in which the polymer B is produced. In this pail you need to No fresh catalyst was added to the last reactor.

However, it is also possible to prepare polymer B in the absence of polymer A and then subsequently the suspensions of polymer A and polymer B to mix. The catalyst system used here for Production of polymer B can be the same as that which is used in the production of polymer A or it can be different from it. This procedure can also be carried out continuously.

In the preparation of the catalyst component D, the mixing of Al (alkyl) ₂ Cl and TiCl ^ is preferably carried out as gradually as possible, the molar ratio Al (alkyl) pCl / TiCl ^, between 0.5 and 1.2 preferably not being achieved before at least half an hour has passed.

Furthermore, it is essential that the particles of the catalyst component D should be relatively round, smooth granules. Therefore, all internal parts of the reactor in which this component is produced should be ^{cooled to the temperature below -5 0} C before the aluminum dialkyl chloride or the titanium tetrachloride is fed into the reactor

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and the presence of aromatic hydrocarbons in the diluent should be avoided if possible. Preferably, the catalyst component D is so prepared that first the aluminum dialkyl chloride is added to the Eeaktor and then the titanium tetrachloride is fed in. In the preparation of the catalyst component D, both the titanium tetrachloride and the aluminum dialkyl chloride preferably in a concentration of more than 500 mmol / l paraffinic diluent used, the most preferred concentration of aluminum dialkyl chloride being lower than 1800 mmol / l Diluent.

Examples of suitable paraffinic diluents are alkanes with 4 to 10 carbon atoms, such as η-butane, n-pentane, n-hexane, 2,2,4-trimethylpentane, n-decane, isomers of these Hydrocarbons or mixtures of the alkanes mentioned. The presence of a significant amount of cycloaliphatic hydrocarbons in the diluent is not very desirable. Liquid propane or propene can also be used as diluents be used. It is recommended that it be ensured that the thinner is dry and practically free from Is oxygen, i.e. contains less than 250 ppm oxygen.

In the preparation of the catalyst component D, Al (alkyl) Gl _{2 is} formed in addition to TiCT ^, this compound preferably being removed from the mixture obtained, for example by washing with an aliphatic diluent, or in Al (alkyl) pCl, for example by reaction with an aluminum trialkyl is transferred by complexing with a Lewis base at a temperature below 20 ⁰ C, preferably below ⁰ ° C, or in a complex, for example.

In general, the mixing of Al (alkyl) ₂ Cl and ^ is TIGL

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gradually carried out. For this purpose, the stirring is preferably carried out with an epean stirring energy of 50 to 2000 W / m ^, in particular 80 to 800 W / m ^. The stirring energy is determined by measuring the torque of the drive motor and the speed of the stirrer according to JH Rushton, EW Gostich and HJ Everett in Chem. Eng. Progress 46, (1950), pages 395 to 404 and 467 "to 477. The specific stirring energy is the stirring energy in watts / nr reactor filling. In general, the dimensions of the particles of catalyst component D formed are smaller when the stirring energy is greater. Usually the diameter of these particles varies between about 6 and about 25 / µm, with the most preferred particle size being between 13 and 17 / µm.

The temperature rise from below -5 ° C to 70 to 200 ° C is preferably carried out as gradually as possible. In this process step, a temperature increase of 0.1 to 1.5 ° C / min is preferred as long as the temperature is still below -45 ° C, while it is also recommended that the temperature between +15 and +45 ⁰ O at least 3 / Maintain 4 hours and a maximum of 2 hours. The time during which the temperature is between 70 and 200 ° C can be shorter if the temperature is higher. If the heating is ^{carried out at 150 to 160 °} C., a heating time of about 1 hour is sufficient. If the heating is carried out at 100 ° C., this temperature must in most cases be maintained for at least 20 hours in order to bring about a sufficient conversion of ß-titanium trichloride into γ-titanium trichloride.

After heating to temperatures between 70 and 200 ⁰ C, the Geadsca is usually left to cool to temperatures below 70 ⁰ G, for example, to ambient temperature.

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It is further preferred that the reaction vessel in which the mixing of Al (alkyl) ~ 1 and TiCl ^ is carried out does not contain any partitions.

High-speed stirrers are preferably used in this container used, which have a stirring volume of less than 10% of the internal volume of the container and with a peripheral speed (at the top) of more than 0.5 m / sec. Turbine agitators are most preferred.

The organometallic component 0 of the catalyst is preferred ™ wise an aluminum dialkyl chloride. The most suitable ratio of this component to the catalyst component D is such that the atomic ratio of aluminum to titanium is from 0.5: 1 to 10: 1. The most preferred component C is aluminum diethyl chloride.

In the preparation of the catalyst component D, the preferred aluminum dialkyl chloride is aluminum diethyl Chloride used.

Optionally, the polymerization in the presence of Catalyst components G and D are carried out, while J very small amounts of water are metered in. Usually In this case, less than 10, e.g. 2 to 6 parts by weight of water per million parts by weight of diluent are used.

The viscosity number of polymers A and B and accordingly The melt index of the finished mixture of polymers A and B can also be changed, for example, by changing the polymerization temperature and / or adjusted by using hydrogen. It is preferably ensured that the Viscosity number of polymer A between 1.5 and 4 (measured at 135 ° O in decalin) and that the melt

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index of the finished mixture of polymers A and B 0.2 Ms 10 "
Part One.

to 10, measured at 230 ⁰ C according to British Standard 2782,

The ethene content of the rubber-like copolymer B and the weight ratio of this polymer to the sum of the Polymers A and B can be calculated from the substances used will. It is also possible to calculate these values with the help of infrared analysis, whereby, among other things, from a peak absorbance at 13.89 µm and at absorbance at 13.62 / µm use is made and calibration is performed with Samples are carried out for which the Athens content is known (e.g. samples containing Athens marked with C).

The inventive method is excellent for continuous Preparation of suspensions suitable in which the desired polymer end product in high concentration exists and from which »by removing the

Thinner non-adhesive polymer powder

only
which do not have good flow properties of the powder and a favorable melt index, but can also be processed into products in which the impact resistance and the yield point have very favorable values. Furthermore, the powders usually contain less than 10% by weight of substances which can be extracted with boiling diethyl ether.

The flow rate of the powder is expressed in sec / 1 and measured according to ASTM-D 1182-54. The impact resistance is measured in m «kg at 0 ° C according to British Standard 2782, Part III.

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examples

A number of experiments were carried out continuously with the loss of two polymerization reactors in Were connected in series, with propene in the first reactor at 60 ° C to form a predominantly isotactic propene homopolymer was polymerized. The catalyst system consisted of aluminum diethyl chloride and a γ-titanium trichloride, its Production is described in more detail below. the

The viscosity number of the homopolymers was determined using ^

Hydrogen regulated. The further reaction conditions are given in Tables I and II below.

The polymer suspension formed in the first reactor, which still contained active catalyst, was in the given second reactor in which Athens and propene were copolymerized. Further values about the reaction conditions which were used there are also in Tables I and II together with the viscosity number of the homopolymer and a number of properties of the end product.

The polymer suspension from the second reactor was *

worked up in that butanol and chlorine "hydrogen gas were added one after the other, 3 χ was ^{extracted with water at 50 0} C, using three series-connected combinations of a mixer and a settler, after which, after mixing with 0.05 wt. -% (based on the polymer) 1,2,5-trimethyl-2,4-, 6-tri (3,5-di-tert, -butyl-4-hydroxybenzyl) benzene and a small amount of sodium carbonate (pH value about 9) ₅ isolate the end product from the organic layer above by removing the diluent with steam and drying the product obtained at 70 ° G under nitrogen.

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The γ-titanium trichloride used as catalyst component D was previously prepared by using two premix reactors connected in series under nitrogen. For this purpose, all internal parts of the first premix reactor were brought to a temperature of -30 ° C, after which first the total amount of alumium diethyl chloride, cooled to -30 ° C, was added to the reactor and then titanium tetrachloride was added, the temperature of which was also -30 ⁰ C was. During production, stirring was carried out continuously with a turbine stirrer with 6 blades using a specific stirring energy of 300 W / nr.

The aluminum diethyl chloride and the titanium tetrachloride were in the first premix reactor in a molar ratio accordingly the reaction equation:

1 TiCl ^ + 0.75 Al (ethyl) ₂ Cl - * 1 _{TiCl 5} .0.25 AlCl ₅ + 0.50

Al (ethyl) Cl ₂ + Athens + Ithane

premixed. The aluminum diethyl chloride and the titanium tetrachloride were previously dissolved in a hydrocarbon fraction containing about 33% by weight of 2,2,4-trimethylpentane and contained over 62% by weight of other octane isomers and had a boiling range of about 100 to 112 ° C and was practical was free of aromatics, water and oxygen. The concentration of aluminum diethyl chloride was about 800 mmol / l and the concentration of titanium tetrachloride about 2,000 mmol / l. The titanium tetrachloride was added over 3 hours. During this addition, the reactor contents were increased to -30 to -35 ° C held. The temperature was then maintained the said stirring conditions of the first premix reactor gradually increased to 40 ° C, after which it for

Was held at 40 ° C for 2 h.

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The Reaktiansprodukt obtained was placed in the second Vontisehreaktor where it was gradually heated from ⁰ to 160 G 4-0 also with stirring, after which it was maintained at 160 ⁰ C 1 h and was then cooled to room temperature within h of Figure 1.

During this production, a nitrogen-containing gas atmosphere was maintained in both premix reactors.

The particle size of the catalyst component D prepared in this A manner was 14 to 16 µm. In order to free this γ-titanium trichloride from aluminum ethyl dichloride as far as possible, the product obtained from the second premix reactor was washed 2 under nitrogen with the dry hydrocarbon fraction mentioned.

In the following Tables I and II, which indicate the polymerizations and copolymerizations and the reaction conditions and the properties of the products obtained are in Table I Production of final products with a melt index of about 0.5 to 1.0 and in Table II the preparation of the end products with a melt index of about 2.5 to 5 are given. I.

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- 12 0? A B E L L E

Attempt. No.

68 68 60 60 1.9 1.9 1.8 1.8 35/65 35/65 35/65 35/65 36 35 34 33

Reaction initiation

Homopolyerization (continuous)

Temperature, ⁰ C 60 60 60 60

Total pressure, ata 6 6 6 6

TiCl ₃ conc., Mmol / 1 3.3 3.3 3.3 3.3

Molar ratio AlEt ₂ Cl ₁ (TiGl ₃ 3 3 3 3

Polymer conc. in final suspension,

% By weight 32 31 29 27

Copolymerization (continuous) Temp erature, ⁰ C
Total pressure ata *

Molar ratio C ₂ ~ ^ ^C 3 ⁱⁿ protective gas

Polymer conc. in final suspension,

Wt%

Product features
Homopolymer

Viscosity number, dl / g 3.3 3.3 3.4 4.0 End product

Melt index, g / 10 min rubber content,% by weight rubber content of C _o ⁼ ,% by weight

2 Yield strength, kg / cm impact strength at 00 _C , m.kg

Ether extract **,% by weight powder flow rate,

sec / 1 9.0 8.1 9.0 10.0

* Co "+ 0y ~ + nitrogen + diluent vapor
** with boiling diethyl ether

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0.9 0.9 0.8 0.5 10.0 12.0 13.7 18.6 61 62 60 59 300 285 270 240 0.69 1.7 1.17 1.31 5.5 5.5 5.0 4.5

O 60 60 60 - 60 60 60 6th b 6th 6th 6th 6th 6th 3 3 3 3 3.3 3 3 3 3 3 3 3 3 3

Q? A B E L L E II

Experiment no. £ 6 7 8 9 10 ΛΛ_

Reaction conditions homopolymerization (continuous) temperature, ⁰ C
Total pressure, ata
TiGl, conc., Mmol / 1 molar ratio AlEt ₂ CIrTiCl ₅

Polymer conc. in final suspension,
_ ^% By weight 28 30 27 26 26 30 26

^ Copolymerization (continuous)

00 temperature, ⁰ C 60 60 60 60 75 75 68,

w total pressure * ata_ _ 1.75 1.75 1.75 1.75 2.0 2.0 1.9

^ ¹ _{C P} / C ₇ molar ratio. in vn

^ ^{Shielding gas d} * 30/70 30/70 30/70 30/75 35/65 35/65 35/65,

^ Polymer conc. in final suspension,

o>% by weight 30 33 30 30 30 35 32

Product features
Homopolymer
Viscosity number dl / g · 2.5 2.6 2.6 2.3 2.7 2.6 2.7

End product

Melt index g / 10 min 3.0 3.5 2.5 5.0 2.5 2.8 2.2 >

Rubber content,% by weight 7.4- 8.4 10.2 12.8 14.0 15.5 18.8 vm

Content of G ₀ = in rubber,% by weight 54 55 55 54 5 ^

Yield strength ^ kg / cm ^ impact strength at OC,

kg-m

Iether extract **,% by weight 5,
Powder flow rate, sec / 1 10.0 11.0 10.2 10.9 10.5 8.2 13.4

- ^ * C ⁼ + C ⁼ + nitrogen + diluent vapor °°

4 = · ^V 2 ₅ CJ

ι ** with boiling

3.0 3.5 2, 5 2 5, 0 9 2.5 2.8 2.2 7.4 8.4 10, 2 12, 8th 14.0 15.5 18.8 54 55 55 54 61 57 58 300 290 280 275 270 260 235 ζΟ, Ο34 0.165 0.455 0.69 0.83 0.83 1.1 5.8 7.9 7.8 6.1 8th 7.6 7.3 10.0 11.0 10, 10, 10.5 8.2 13.4

Claims (20)

PATENT CLAIMS 1) Process for the production of polypropene compounds in powder form, which can be processed into products with improved impact resistance and a predominantly isotactic Propene polymer (polymer A) and a rubber-like ethene-propene copolymer (polymer B), the may optionally be bound to the polymer A, contain, by (a) Polymerizing propylene to form a suspension of polymer A, (b) Copolymerizing Athens and propene to form a polymer B containing suspension and (c) Mixing the polymers A and B during or after the copolymerization (b), worked in the presence of a liquid diluent and this from the resulting finished polymer suspension is then removed, characterized in that one (1) the preparation of the suspension of the polymer A in the presence of a catalyst system which consists of a Organometallic component C and a component D is made and by previously mixing a dialkylaluminum chloride Al (alkyl) oCl and titanium tetrachloride in a liquid paraffinic Diluent with stirring at a temperature below -5 C in a molar ratio of 0.5 to 1.2 and subsequent increase in the temperature of the mixture obtained to 70 to 200 ° C with constant stirring is, (2) the polymerization of polymer A up to a viscosity number of 1 to 4.5 dl / g, measured in decalin, carried out at 135 ° C, (3) carries out the copolymerization of Athens and propene in such a way that that the polymer B 20 to 90 wt .-% copolymerisier- - 15 109 8 3 5 / U68 1A-39 127 - 15 - tes Athens contains, (4-) a weight ratio of polymer B and the sum of the Polymers A and B from 0.08 to 0.20 in the finished Suspension respects, and (5) a melt index of the finished mixture of polymer A and polymer B of 0.1 to 15 * 0, measured at 2JO ⁰ O according to British Standard 2782, Part I. 2) Method according to claim 1, characterized in that it continues the polymerization at the preparation of the suspension of polymer A, to a polymer concentration% of more than 25 wt .-% is reached. 3) Method according to claim 1 or 2, characterized in that the polymer concentration in the suspension obtained as the end product before the removal of the diluent is from 30 to 37% by weight. 4 ·) Method according to claim 1 to 3, characterized in that the finished suspension a weight ratio of polymer B to the sum of polymer A and polymer B of 0.08 to 2.0 thereby sets that the preparation of polymer B in the presence of a suspension of polymer A, which is still active Contains catalyst, performs. 5) Method according to claim 4-, characterized in that the polymerization to the polymer A and the copolymerization to polymer B is carried out continuously in separate reactors, and the suspension, which is obtained at the end of the production of polymer A and still contains active catalyst, is fed into a reactor, in which the polymer B is produced. - 16 109835/1468 1A-39 127 - 16 - 6) Method according to claim 1 to 5 »characterized in that in the preparation of the catalyst component D, the aluminum dialkyl chloride and the titanium tetrachloride is ^{mixed at a temperature above -45 0} C and the mixing is carried out so gradually that the molar ratio of aluminum dialkyl chloride: titanium tetrachloride of 0.5 to 1.2 is not reached until at least half an hour has passed. 7) Process according to claim 1 to 6, characterized in that the mixing of aluminum dialkyl chloride and titanium tetrachloride is initiated ^{at a temperature of -10 to -40 0 C in the preparation of the catalyst component D.} 8) Process according to claim 1 to 7 »characterized in that in the preparation of the catalyst component D, all inner parts of the reactor in which the preparation takes place, ^{cooled to a temperature below -5 0} C before aluminum dialkyl chloride or titanium tetrachloride in the reactor feeds. 9) Method according to claim 1 to 8, characterized in that in the production of the Catalyst component D first the aluminum dialkyl chloride and then the titanium tetrachloride in the reactor, which is used for Production is used, feeds. 10) Method according to claim 1 to 9 »characterized in that in the production of the Catalyst component D is the molar ratio in which aluminum dialkyl chloride and titanium tetrachloride are mixed can be set from 0.65 to 1.00. 11) Method according to claim 1 to 10, characterized in that g e k e η η - 109835 / U68 -17- 1A-39 127 draws that in the preparation of the catalyst component D both the titanium tetrachloride as well as the aluminum dialkyl chloride in one concentration of more than 500 mmol / l paraffinic diluent applies. 12) Method according to claim 11, characterized in that there is a concentration of Aluminum dialkyl chloride of less than 1800 mmol / l paraffinic diluent applies. 1 13) Method according to claim 1 to 12, characterized in that in the production of the Catalyst component D removed the aluminum alkyl dichloride formed during the preparation from the mixture obtained or converted into aluminum dialkyl chloride or into a complex. ' Process according to Claims 1 to 13, characterized in that during the production the catalyst component D carries out the stirring with a specific stirring energy of at least 50 W / nr. 15) Process according to claim 1 to 14, characterized in that the catalyst component is used C aluminum dialkyl chloride used. 16) Process according to claim 15 »characterized in that aluminum diethyl chloride is used as catalyst component C, and aluminum diethyl chloride is also used as aluminum dialkyl chloride in the preparation of catalyst component D. 17) Method according to claim 1 to 16, characterized in that - - 18 -109835 / U88 1A-39 127 - 18 - indicates that the copolymerization is carried out so that the polymer B 40 Ms 70 wt .-% Contains copolymerized Athens. 18) Method according to claim 17 »characterized in that the copolymerization is carried out that the polymer B 50 to 65 wt .-% copolymerized Athens contains. 19) Process according to claim 1 to 18, characterized in that in the final suspension there is a weight ratio between polymer B and the sum of the polymer Sets A and B from 0.11 to 0.15. 20) Method according to claim 1 to 19, characterized in that the method is carried out that the viscosity number of polymer A is 1.5 to 4- and the melt index of the final mixture of polymer A and Polymer B is 0.2 to 10.0. 78XXIV 109835 / U68