JPS5838444B2 - Crystalline propylene polymers and copolymers and their production methods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing crystalline propylene polymers and copolymers having excellent physical and mechanical properties, and novel polymers and copolymers obtained by the method. It is.

In particular, the present invention contains a reaction mixture of propylene or a mixture of propylene and ethylene and/or alpha olefin, a metal organic compound of aluminum, a halogenated Mg compound on at least the surface, a Ti compound, and an electron donor compound. The polymer which was polymerized in the presence of the catalyst obtained from the solid catalyst component and separated from the polymerization zone was 90%
The isotactic index ranges from ~96 and 0.
Melt index ranging from 5 to 30 g/10 minutes and 13,000 to 1 according to ASTM D747-40
8, O O O A simple method for producing crystalline propylene polymers and copolymers having a bending stiffness of kg/crrt.

Traditionally, many of the industrial methods used to produce crystalline propylene polymers and copolymers with high mechanical properties are based on titanium trichloride and A1 metals using propylene or its mixture with ethylene as the main catalyst. The polymer is polymerized in the liquid phase in the presence of a Ziegler-Natsuta stereospecific catalyst consisting of an organic compound, and when leaving the polymerization zone the polymer is used to remove catalyst residues and to extract as much atactic polymer fraction as possible. Submit to processing.

These treatments achieve the highest possible isotactic
A polymer having an index can be obtained.

Isotactic index means the weight ratio of polypropylene that is insoluble in boiling n-hebutane.

This is due to the fact that the most typical mechanical properties of polypropylene, such as bending stiffness, are good, but the melt index is equal and the isotactic index is high.

These treatments are aimed at reducing to a minimum the aggressive polymer fractions, especially the low molecular weight fractions (oils) which are soluble in acetone at room temperature, which have a negative and very significant effect on the mechanical properties of the polymer. .

Therefore, with the Ziegler-Natta catalyst conventionally used in stereospecific polymerization of propylene, crystalline polymers of propylene or Unable to obtain copolymer.

In particular, producing polypropylene endowed with good mechanical properties by using a process in which all or much of the polymerization solvent or liquid propylene used as reaction medium is removed by techniques such as flash evaporation or steam stripping. It is not possible to do so, and this involves a change in the state of the solvent or monomers and thus does not or only partially removes the amorphous polymer portion produced during the polymerization.

A catalyst for the polymerization of propene, prepared from a metal-organic compound of AI and a solid catalyst component consisting of Ti, Mg and Lewis bases, has been recently presented which provides good stereospecificity and is very active under operating conditions. .

(See Ikley Patent No. 932,438).

Due to the high amount of polymer produced per gram of Ti,
These catalysts can avoid purifying the polymer from catalyst residues and thus simplify the polypropylene production process.

Isotactic indexes of polymers produced with the above-mentioned catalysts under the production and utilization conditions described in Ikley Patent No. 932,438 are up to 92-93.
reaches the value of

The melt index of the polymer is very low because the polymerization is carried out in the absence of hydrogen.

(0.3.!ii'/10 minutes or less).

When hydrogen is used to control the molecular weight of the polymer in the catalytic polymerization process described above,
It is noted that the index decreases significantly.

The greater the decrease in the isotactic index, the higher the melt index of the polymer to be obtained.

The isotactic index is, for example, 9 2'-9
3 (polymer melt index below 0.3 g710 minutes) to a value of 8586 for a melt index of s-log710 minutes.

The significant loss of propylene as an active polymer of little or no practical interest that would occur in a process that utilizes hydrogen for molecular weight control precludes the possibility of utilizing these catalysts in practice. hinder.

Furthermore, when polymerizing in liquid propylene due to the high percentage of active polymer to be removed, it is necessary to resort to extraction methods different from those based on the use of liquid propylene, thereby making it possible to The percentage of atactic polymer that can be removed is only 2-3 φ.

For example, it is necessary to carry out washing with a solvent such as butane, which in practice makes it possible to obtain polymers with a sufficiently high isochastic index.

However, washing with butane, instead of being simple, complicates the possible process of producing polypropylene in liquid monomers using the catalysts of the aforementioned technology.

If the polymers produced in the presence of inert hydrocarbon solvents and catalysts of the aforementioned technology are subjected to the conventional extraction processes used in industrial processes for producing polypropylene, a sufficiently high isotactic index ( 96～
97 or higher) can be obtained.

However, even in this case, the excessive loss of propylene as an amorphous polymer makes the process uninteresting.

In the present invention, surprisingly, even the presence of hydrogen is obtained from an AI organometallic compound and a solid fraction containing at least on the surface the reaction product of a halogenated Mg compound, a Ti compound, and an electron donating compound. 90 to 9 with the catalyst
In the case of polymerizations of propylene carried out in the presence of something suitable to promote the stereospecific polymerization of propylene to polymers with isotactic indices from 6 to 96, much higher isotactic indices can be obtained from crude polymers. The physical and mechanical properties under a melt index comparable to, or in some cases equal to, the physical and mechanical properties of polymers prepared with conventional high standing water specificity catalysts based on TiCA3 having and from which the atactic moieties have been removed. It has been recognized that there is no need to remove parts of the active polymer that have higher physical and mechanical properties.

It is therefore an object of the present invention to provide a solid catalyst containing reaction products of an AI metal organic compound and at least on the surface a halogenated Mg compound, a Ti compound and an electron donating compound in the presence of hydrogen as a molecular regulator in the liquid phase. propylene or a mixture thereof with ethylene and/or alpha olefin in the presence of a catalyst obtained from the components and capable of producing a polymer having an isotactic index of 90 to 96, and the liquid phase is removed from the polymerization mixture. removed by evaporation, with an isotactic index ranging from 90 to 96 and from 0.5 to 30 g/10
Melt Index of 13,000-18, OOOkg/cIIF. according to ASTM D747-40. The object of the present invention is to provide a new method for producing crystalline propylene polymers and copolymers exhibiting excellent physical and mechanical properties, which consists in recovering a polymer having a bending stiffness of .

According to a preferred embodiment of the process, propylene or mixtures thereof with ethylene and/or alpha-olefins are prepared in the presence or absence of an inert hydrocarbon diluent to produce a polymer having an isotactic index of 92 to 96. Polymerize with a suitable catalyst.

Yet another object of the invention is an isotactic index ranging from 90 to 96 and an isotactic index ranging from 0.5 to 30 g/10.
Minute range melt index and ASTM D747
-40 from 13,000 to 18, O O O k
The present invention provides crystalline propylene polymers and copolymers having a bending stiffness of g/ffl.

A particularly interesting feature of the polymers and copolymers according to the invention is their low content of oils extractable with acetone at room temperature.

The fact of having a low percentage of oil can significantly simplify currently used polypropylene manufacturing processes.

According to the invention, the polymer product is removed from the liquefaction by evaporation of the liquid phase at the end of the polymerization in order to obtain a polymer product with an intactic index of 95 to 96 exhibiting the desired characteristics. Alternatively, separation can be achieved by mechanical methods such as those described above.

Such biomaterials have physical and mechanical properties comparable to, and in some cases better than, polymers having high isotactic indices and having a very high degree of removal of acidic moieties prepared by conventional methods. It has mechanical properties.

Other interesting features of the polymers and copolymers of the invention are:
At least 70 fractions of the spherulites are in a microscopic structure with a size of 80μ or less.

The construction involves a 3 mm thick plate that was molded at 200° C. and 200 atmospheres for 5 minutes and cooled to room temperature for 20 minutes.

It is believed that this structure is due to the action of catalyst residues remaining on the polymer as a nucleating agent.

From this point of view, polymers and copolymers whose ash content contains an amount of Mg and halogen corresponding to a magnesium halide content not exceeding 150 ppffl are of particular interest.

As already pointed out earlier, the process according to the invention consists of the monomers to be polymerized or a solution of the monomers of the polymer in an inert hydrocarbon solvent (butane, pentane, hexane, heptane, cyclohexane, etc.). It is very advantageous to carry out the process in a liquid phase consisting of:

However, polymers and copolymers can also be produced by polymerizing propylene in the gas phase.

In this case, suitable catalysts and/or operating conditions are selected to provide a polymer with an isotactic index of about 94-96.

Polymerizations in both liquid and gas phase are generally carried out over a wide temperature range from 0°C to 100°C, in particular from 40'C to 90°C.

Operation takes place at atmospheric pressure or above.

Propylene can be polymerized alone or in admixture with ethylene and/or alpha olefins such as butene-1,4-methylpentene-1 and the like.

Propylene is polymerized in the first step, while the ethylene-propylene mixture is polymerized in successive steps.

The operating conditions are such that in the first step a polymer having an isotactic index in the range 90-95 is obtained.

In this case, polymers are obtained which have improved properties of resistance to brittleness at low temperatures.

The amount of polymerized ethylene derived by these methods is 30 to 3
6 weight φ is not exceeded, while the content of polymer formed in the second step ranges from 5 to 40% based on the total polymer composition.

The ethylene content of the copolymer ranges from 70 to 90 gm.

As mentioned above, catalysts useful in producing the polymers and copolymers of the present invention contain as main components an AI metal organic compound and at least on the surface a halogenated Mg compound, a titanium compound, and an electron donating compound such as a Lewis base. It consists of a reaction product with a solid catalyst containing a reaction product.

The Lewis base is preferably selected from esters of polyamines with oxygen-containing inorganic acids or organic acids.

Some examples of such compounds are alkyl esters of aromatic acids such as benzoic acid, p-ethoxybenzoic acid and p-}ruyl acid: for example, N', N'', N'9 N', tetramethylethylenediamine, It is an alkylene diamine such as

AI metal organic compounds are <AI-MJ ethyl, AI
- AI-N such as triisobutyl, AI-4lipropyl
Choose from alkyls.

AI metal-organic compounds as described in Italian Patent Application No. 24287A/75 are likewise used.

The AI metal organic compound is preferably used in combination with a portion of the Lewis base.

The molar ratio between the Lewis base and the AI organic compound is 1 or more,
It is preferably in the range of 02 to 04.

In general, solid catalysts or solid catalysts can be used under X-rays to detect
When l/Mg ratio is 1, d=2, 43 people and d=
Contains a halo with a maximum intensity of 3.20 interplanar distances: conversely, when bromine is present in the catalyst fraction at a B r/Mg ratio >1, the maximum intensity of the halo is a=2. soi and d=3.2
It is characterized by showing a spectrum between five people.

Catalyst or titanium halide compound and Lewis salt in 3m
by contacting with magnesium halide in active form having a surface area (or specific area) greater than or equal to It can be manufactured by manipulating.

For example, the preparation of Ti compounds, electron donating compounds and Mg compounds, or halogenated Mg and T
The method consists in pulverizing the mixture of the i-compound and the complex previously obtained from the electron-donating compound.

Generally the Ti content in the catalyst compound ranges from 0.5 to 10 by weight and the Mg/Ti ratio is greater than or equal to 1, especially in the range from 2 to 10.

The Al/T i ratio used in catalyst production is greater than or equal to 1 and generally ranges from 5 to ioooo.

Catalysts falling within the above definition are disclosed, for example, in the following patents and patent applications of the applicant: Belgian Patent No. 785,332,7
85,333 and 785,334: French Patent Application No. 2,1 1 3,3 13; Italian Patent Application No. 2 3,9 6 9A/7 5 and 2 4
, 287A/75.

Other suitable catalysts are described in DOS2504036.

When producing these catalysts, the polymerization can be controlled by appropriately selecting the Lewis base, the ratio between the base and the AI metal organic compound, and the polymerization conditions (catalyst concentration, monomer concentration, polymerization temperature, residence time). The polymer has a controlled molecular weight (melt index of 0.5 or higher) directly and with very high proportions and avoids or reduces to a minimum the washing of the polymer to remove the aggressive polymer parts. It is possible to obtain polymers with an isotactic index of 92 to 95, which is sufficient for

The use of these catalysts under the above conditions significantly simplifies the polypropylene production process.

Some typical examples of catalysts that achieve the above results in the polymerization of propylene carried out in liquid monomers are alkyl esters of benzoic acid, p-toluic acid or p-alkoxybenzoic acid (ethyl p-methoxybenzoate, Methyl
by grinding anhydrous Mg chloride in the presence of an alkyl ester of TiCl4 and benzoic acid with an AI-H alkyl (such as AI triethyl, AI-triisobutyl, etc.) partially complexed with p-4 ethyl chloride, etc. It is obtained from a catalyst fraction produced by co-pulverizing Mg and a composite previously obtained from TiCI4 and an alkyl penzoate (ethyl penzoate, methyl penzoate, etc.).

The amount of Ti present in the catalyst fraction ranges from 1 to 7 by weight:
For esters, the ester/TiCl4 molar ratio is generally 05~
3.

The ester/Al-trialkyl molar ratio is 02-0.4.

(By increasing the S ratio,
The index can be increased, but in some cases the polymer yield is reduced).

In general, the concentration of a certain amount of solid catalyst is 002 ~
0. 0 8 g/kg.

The polymerization temperature is 50-85°C.

(The isochastic index increases with increasing temperature apart from a certain concentration of solid catalyst).

The catalyst can include modifiers, inert solid diluents, flocculants, and the like.

In particular, compounds of elements belonging to Groups 1.11, III, and II of the periodic table that do not react with Mg halides other than Mg compounds are used.

The following examples specifically illustrate the industrial features of the present invention, but the present invention is not limited to these examples.

The isotactic index values given in the specification and reported in the examples relate to powdered polymers that are not granulated under granulation conditions as obtained during polymerization.

In the case of the polymers and copolymers according to the invention, the value of the isotactic index determined for the powder obtained from the granulated polymer is generally the isotactic index for the polymer in the powder obtained during the polymerization. higher (1-2 units) is allowed.

This is particularly the case when the polymer is obtained in liquid propylene, where the bulk density is relatively low.

(0.4g/less than 1).

The isotactic index is measured over a 24 hour period in a Kumagawa extractor.

Bending stiffness is measured according to standard ASTM D 747-40 (50 span); melt flow index is determined according to standard ASTM D 1238-70; bulk density is determined according to standard DIN 53194; temperature is measured according to standard ASTM D 1525-70 (5 kg): Rockwell hardness was measured on the standard ASTM D785-70 Method B-Alpha scale.

Example 1 In a 135 l autoclave equipped with a stirrer, under propylene pressure, 24 g of AI-41J ethyl (as a 12 weight part hebutane solution), 37 kg of liquid propylene and 18.94 g of methyl p-toluene were added in sequence. (120c
c) an additional 3 kg of propylene dissolved in hebutane
Charge using pressure.

The orethoclave was heated to 60'C and then 50N1 of hydrogen and a complex of MgCI2, TiCl4, and ethyl benzoate in a 1:1 molar ratio were added in a vibratory mill for 55 minutes.
Two parts of the catalyst produced by milling for 0 hours,
486 g are introduced into it.

The crusher filling rate is Q, 135 g/11.

The ground raw material contains 4.85 parts by weight of Ti and 61.9 parts by weight of CI.

The autoclave temperature is then brought to 65°C and held at that value for 3 hours.

Residual propylene was then removed by flashing and the polymer was removed from the autoclave and heated in an oven for 70 to 70 minutes.
Dry at 80° C. under a stream of nitrogen.

The amount of polymer obtained and the properties of the polymer in powder and granules are shown in Table 1.

Example 2 The test of Example 1 was repeated with the difference that 85 Nl of H2 were used and that after polymerization the residual monomer was drained off and replaced with 27 kg of fresh propylene.

After stirring for 1 hour at 30-35°C, the polymer was recovered and dried.

The results obtained are shown in Table 1.

? Example 3 8.8 l of heptane, 630 CC of heptane containing 8 g of AI-triethyl and 4.68 g of ethyl p-methoxybenzoate, which had previously been brought into contact with each other, were added in sequence to a 20 l volume of heptane equipped with a stirrer under propylene pressure. Introduce into autoclave.

Simultaneously in a vibrating mill for 70 hours, anhydrous MgCl and TiC
0.69 g of a portion of the catalyst prepared by milling a 1:1 molar complex of 14 and ethyl penzoate
is introduced into the autoclave as a suspension in 750 cc of hebutane.

The Ti content of the ground raw material was 7.1%, and the CI content was 58.6%.

Then 2.7Nl of hydrogen and 10kg/crit. Introduce propylene up to gauge pressure.

The temperature is then brought to 60° C. and held at that value for 1.5 hours.

The solvent is removed by evaporation. The amounts and properties of the polymers obtained are shown in Table 2.

Example 4 The test of Example 3 was repeated except that 6.65 g of ethyl p-methoxybenzoate and 11.3! Repeat with 1 of A1-triethyl.

The pressure during polymerization is 8 kg/d gauge.

At the end of the test, the solvent is removed by evaporation.

The results obtained are shown in Table 2.

Example 5? The test of Example 3 was repeated except that anhydrous MgCl, TiCl4 and l
It was repeated with a portion of the catalyst prepared by milling a mixture with ethyl penzoate in a molar ratio of 0.659:1 to TiCl4.

The titanium content is 6.1 yen, and the CI content is 61.3 yen.

A further 5.72 g of ethyl p-methoxybenzoate are used.

At the end of the polymerization, the solvent is separated from one part of the slurry simultaneously by evaporation, the separation being carried out by centrifugation at 50.degree.

The results obtained are shown in Table 2.

The properties of the polymer obtained by evaporation are shown in column A, and the properties of the polymer after centrifugation are shown in column B.

Example 6 The test of Example 3 was carried out using solid catalysts of 4.6 Ti and 6
It was repeated with the difference that it contained 1.7% CI and used 0.68 g of the aliquot.

An additional 4.75 g of methyl p-}leate was used.

The polymerization temperature is 75°C.

The time required for polymerization was 3 hours.

The solvent is separated by evaporation.

The results obtained are shown in Table 2.

Example 7 8.70r/Ll of hexane, 0.3g of ethyl beforehand”
1,135 g of AI-triisobutyl in contact with p-toluate are introduced under propylene pressure into a 2.54 autoclave equipped with a stirrer.

Then, anhydrous Mg Cl 2 t T t Cl
0 of the catalyst component prepared from 4 and ethyl benzoate.
．． 071.9 is introduced into the autoclave in suspension in hexane.

The Ti content of the catalyst component is 1.9 parts by weight, and the C1 content is 647 parts by weight.

The total volume of hexane solution in the autoclave is 1 l.

Next, 115ml of hydrogen and 5.4kg/cI? Introduce propylene to t-gauge pressure.

The temperature is then brought to 60°C and held at that value for 4 hours.

The solvent is removed by stripping with steam.

The amounts and properties of the polymers obtained are shown in Table 2.

Example 8 40 kg liquid propylene, 36 g AI under propylene pressure in a 1357 autoclave equipped with a stirrer
-}Lisobutyl, 12 g of ethyl p-toluate are charged.

The autoclave is heated to 60 DEG C. and then 80 N1 of hydrogen and a portion of 1.26 g of a catalyst prepared from anhydrous MgCl2, TiCl, and ethyl benzoate are introduced into it.

The Ti content of a portion of the catalyst is 2.05% by weight, and the Cl content is 64
．． 75% by weight and the Mg content was 18.15% by weight.

The autoclave temperature is then brought to 65° C. and held at that value for 3 hours.

The solvent is removed by flash evaporation and the polymer is discharged from the autoclave and dried in an oven at 70° C. under a stream of nitrogen for 3 hours.

The amounts and properties of the polymers obtained are shown in Table 3.

Example 9 The test of Example 7 was repeated with the difference that the polymerization pressure was 7 kg/cri.

At the end of the polymerization, the solvent is separated by centrifugation and the polymer is washed with heptane and dried in a stream of nitrogen.

The results are as follows. melt index
g/10 minutes 1,5 Mageoka lsa kg/= 1
4,000 Example 10 In a 135 l autoclave equipped with a stirrer, 36.9 of AI-triisobutyl (34! l/A' in hexane solution), 36 kg of propylene, 12.45 g of methyl p.
-}ruate (227 g/l! in hebutane solution) 4k
Charge using an additional propylene pressure of p.

The autoclave was heated to 62° C. and then 1.5 ml of catalyst dispersed in 100 liters of hydrogen and 200 ml of hexane was added.
05g is introduced into it.

A portion of the catalyst is prepared from MgCl2tTiCl4 and ethyl benzoate.

The titanium content in the catalyst component is 1.7%, the CI content is 63.4% and the Mg content is 20.35%.

The autoclave temperature is then brought to 60° C. and held at that value for 3 hours.

The polymerization mixture is then dispersed in water and stripped at 70° C. with a stream of nitrogen.

A weight body of 9 kg is obtained.

The properties of the polymer are as follows.

Polymer apparent density in powder g/cryt O. 57 Isotactic index - 96 [η) d
i/g 1.9 Part soluble in acetone at 20°C 1.9% Part soluble in xylene at 20°C 2. Polymer tart index in 2% grains g/10 min 1.6 Flexural stiffness kg/i 1 5, 6 5 0 Elastic modulus kg/i 1 ! 5, (1 30 Rockwell hardness (alpha) 63 Unnotched Izod resilience ky-cm/cIrL1 6 7 Tensile strength kg/cr?L370 Elongation at break 90 Please summarize the embodiments of the present invention. That's right.

(1) The polymers and copolymers according to the invention contain up to 2 parts by weight of the polymer part which can be extracted with acetone at 25°C and up to 4 parts by weight by fractional extraction with tetralin at a temperature gradient. It is characterized by producing a portion that is soluble at 25° C. and a portion that is soluble at 70° C. in an amount ranging from 3 to 6 weight percent.

(2) The polymers and copolymers according to the invention have at least 70% of the spherulites having a size of 80 μm or less and their ash content does not exceed 150 pp [Il].
It has a fine crystal structure containing Mg and halogen in an amount corresponding to the content of g.

(3) The polymer assembly or product is a) Claims, (1) above.
) and 60 to 95% by weight of propylene polymers and copolymers according to any of (2) above, and b) 5 to 5% of crystalline copolymers of propylene and ethylene containing 70 to 90% by weight of polymerized ethylene. It consists of 40 weight sections.

(4) In the method for producing crystalline propylene polymers and copolymers of the present invention, the polymer obtained by removing the liquid reaction phase has an isotactic molecular weight in the range of 92 to 96, particularly in the range of 94 to 96.・Indicates the index.

(5) In the method for producing crystalline propylene polymers and copolymers of the present invention, the liquid phase is separated by flash evaporation or stripping with steam.

(6) The polymer composition of (3) above promotes the polymerization of propylene or its mixture with ethylene into a polymer having an isocuctic index in the range of 90 to 95 in the first step. and consists of a reaction product between a) a metal organic compound of aluminum and b) a reaction product of a halogenated Mg compound, a Ti compound and an electron donating compound, further comprising ethylene or ethylene in a second step. and propylene in the presence of a polymerizable catalyst.

(7) Crystalline polymers and copolymers of propylene are prepared by mixing propylene or propylene with ethylene and/or alpha olefin in the presence or absence of an inert hydrocarbon solvent in a liquid phase to form a metal-organic compound of AI. and a solid catalyst containing a reaction product of a halogenated Mg compound, a titanium compound, and an electron donating compound on at least the surface thereof, and the polymer is The copolymer is obtained by separating the liquid phase itself by mechanical means without evaporation from the polymerization mixture and has a melt index of 05 to 30 g/10 min and 9
The number of isotactics ranges from 5 to 96.

・Has an index

Claims (1)

[Scope of Claims] 1. Propylene, hydrogen as a molecular weight regulator, a) an Al monotrialkyl compound partially complexed with a Lewis base selected from alkyl esters of aromatic carboxylic acids, and b) Mg dichloride. A Lewis base selected from TiCl4 and alkyl esters of carboxylic acids is reacted with a molar ratio of ester/TiC134 of 05 to 3 and a Ti content of 1 to 7% by weight of the catalyst solid. A reaction between a catalyst solid comprising a product and a catalyst solid comprising a product, polymerizing in the presence of a catalyst comprising a product,
According to ASTM D747-40, the melt index ranges from 0.5 to 30 g/10 min and the isotactic index ranges from 90/96, consisting of separation of the crude polymerization product without extraction of the active polymer portion. A crude polymeric raw material that has a bending stiffness of 13,000 to 18,000 kg/ci, contains 2 weight or less of oil that can be extracted with acetone at 25°C, and does not extract the acrid polymer part. A method for producing a crystalline polymer of propylene.