DE3541959A1 - PROPYLENE BLOCK COPOLYMERS AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Description

The invention relates to block copolymers of propylene and a branched oC -olefin having 5 to 12 carbon atoms.

In order to improve the heat resistance and impact resistance of polymers based on propylene, one has hitherto a method used in which an ethylene-4-methyl-lpentene copolymer or a propylene-4-methyl-1-pentene copolymer is used to produce a material which has well-balanced heat resistance and impact resistance, as disclosed in Japanese Patent Laid-Open Patent applications 137116/1980 and 81326/1981 is described. According to these known methods, although the Impact resistance is improved, but there are disadvantages in terms of heat resistance, and in particular the heat distortion temperature is lowered. In addition, since these copolymers are random copolymers, the proportion of amorphous polymers formed is large, thereby creating difficulties in production, such as clogging of the reaction vessels.

Mixing different homopolymers together can be a solution to the above problem, it however, it is difficult to make a homogeneous dispersion by mixing, and it is easy to occur when mixing thermal degradation of the polymer.

The invention is therefore based on the object of providing block copolymers based on propylene which, compared with homopolymers made from the same monomer components or mixtures thereof, have superior thermal properties, and to create a process for their preparation.
35

While some polymer blends have superior thermal properties, their optimal blending range is extremely narrow and high temperatures are required for blending required so that the degradation of polymers is easily caused and uniformity is obtained Dispersion is made difficult.

According to the invention, block copolymers based on Propylene can be made available, by means of which the above disadvantages are overcome. The invention Block copolymers should show high rigidity over a wide range of the composition, high heat resistance, especially high heat deformation temperature, and only a low one should be used in their manufacture Amorphous polymers are a by-product. It is also an object of the invention to provide a method for To create these block copolymers. According to the invention, this object is achieved with the aid of crystalline Block copolymers with superior thermal properties are solved by the block copolymerization of propylene and a branched oil olefin having 5 to 12 carbon atoms can be obtained.

The invention relates to a block copolymer of propylene and a branched QL olefin with 5 to 12 Carbon atoms, which is obtainable in the presence of a catalyst which (1) a solid material which contains at least magnesium and titanium, (2) an organometallic compound and (3) an electron donor and having the following properties (a) through (d):

(A) the proportion of propylene units is 5 to 95 percent by weight and the proportion of units of the branched C ₅ -C. ₂ -oc-01ef ins is 95

35 to 5 percent by weight;

(b) an intrinsic viscosity, determined in decalin at 135 ° C, of 0.5 to 10 dl / g;

(c) at least one of the using a differential scanning calorimeter (DSC) measured melting point is not less than 145 ° C; and

(d) the modulus of flexural rigidity) (according to ASTM D-747-70) is 8000 to

15000 kg / cm ² .

The invention also relates to a process for the preparation of a block copolymer from propylene and a branched α-olefin, which has the following properties (a) to (d), by copolymerizing propylene with a branched OL-olefin having 5 to 12 carbon atoms in the presence a catalyst which comprises (1) a solid material containing at least magnesium and titanium, (2) an organometallic compound and (3) an electron donor, the copolymerization including a first polymerization stage and a second polymerization stage, the first polymerization stage at a temperature of is not carried out more than 5O ⁰ C and the second stage polymerization at a temperature of not less than 50 ⁰ C and in the substantial absence of monomers used in the first polymerization:

(a) the proportion of propylene units is 5 to 95 percent by weight and the proportion of units of the branched C ₅ -C ₁₂ -Ot-olefin is 95 to 5 percent by weight;

(b) an intrinsic viscosity, determined in decalin at 135 ° C, of 0.5 to 10

dl / g;

(c) at least one of the melting points measured with the aid of a differential scanning calorimeter (DSC) is not less than 145 ^° C .; and

(d) the modulus of flexural rigidity (according to ASTM D-747-70) is 8000 to 15000 kg / cm ² .

The invention is described below on the basis of preferred embodiments.

(A) Block Copolymer 5 (a) Composition

The block copolymer according to the invention is a crystalline block copolymer which contains the units of propylene and a branched Cr-C. ^ - CC-olefin contains and the has a stereospecific structure.

The composition of the copolymer is such that the Weight ratio of propylene to branched C 1 -C 6 -C olefin in the range from 95: 5 to 5:95, preferably 95: 5 to 40:60 and in particular from 90:10 to 70:30, lies.

When the propylene content of the copolymer is 95 percent by weight exceeds, the heat distortion temperature of the copolymer becomes equal to that of polypropylene and thus low, however, when the propylene content is less than 5% by weight, the heat distortion temperature of the copolymer takes about the same value as that of poly-4-methyl-1-pentene and therefore no copolymer having a high heat distortion temperature is obtained.

(b) Limiting viscosity number (intrinsic viscosity)

The intrinsic viscosity J ^ ¹ JJ of the copolymer according to the invention is in the range from 0.5 to 10 dl / g, preferably 1 to 5 dl / g, measured in decalin at 135.degree. If the value is less than 0.5, the copolymer is difficult to deform because of the too low melt viscosity, and if it exceeds 10, it is difficult to perform deformation because the melt viscosity is too high and the polymer has extremely poor flow properties .

(c) melting point

The copolymer according to the invention is a crystalline block copolymer based on propylene. A block consists of units of propylene and usually melt in the range from 100 to 170 ⁰ C, while the other block by a branched C - C is formed -OC- olefin and melts in the range of 100 to 250 ⁰ C.

The melting point mentioned here means the position of a melting maximum determined by the measurement using a differential scanning calorimeter (DSC) is obtained.

At least one of the abovementioned melting points must not be lower than 145 ^° C., otherwise the heat distortion temperature of the copolymer is lowered in an undesirable manner.

(d) Modulus of flexural rigidity)

The flexural modulus of elasticity of the copolymer according to the invention, measured according to ASTM method D-747-70, is in the range from 8000 to 15000 kg / cm ² . When the value is less than 8000 kg / cm ² , the copolymer is soft and has a low heat distortion temperature. A flexural modulus of elasticity of more than 15,000 kg / cm ² is not desirable because then the copolymer is very

30 becomes brittle if the rigidity is also high.

(B) copolymerization
(a) catalyst

The catalyst used according to the invention consists of a combination of (1) a solid substance which contains at least magnesium and titanium, (2) an organometallic compound and (3) an electron donor. At-

play for the solid substance include materials made by applying titanium compounds to solid inorganic Carriers can be obtained using known methods. Examples of suitable inorganic solids Carriers include metallic magnesium, magnesium hydroxide, magnesium carbonate, magnesium oxide, and magnesium chloride; Double salts, double oxides, carbonates, chlorides and hydroxides, each containing a magnesium atom and a metal or element selected from the group consisting of silicon, aluminum and calcium, as well as materials which by treating or reacting these inorganic solid carriers with oxygen compounds, sulfur compounds, Hydrocarbons, halogen-containing substances, silicon compounds, nitrogen compounds or phos-

15 phosphor compounds are formed.

Examples of suitable oxygen compounds include Alcohols, aldehydes, ketones, ethers, carboxylic acids and their derivatives. Thiophene are used as sulfur compounds and thiols are preferred. Aromatic hydrocarbons are preferably used as hydrocarbons; to Examples include durol, anthracene, and naphthalene. Halogenated hydrocarbons are used as halogen-containing substances preferred; examples of these compounds include 1,2-dichloroethane, n-butyl chloride, t-butyl chloride and p-dichlorobenzene. Preferred examples of silicon compounds are tetraethoxysilane, vinyltriethoxysilane and allyltriethoxysilane. Examples of nitrogen compounds include acid amides, amines and nitriles, with benzoic acid amide, Pyridine and benzonitrile are particularly preferred. Examples of phosphorus compounds include phosphates and phosphites, whereby triphenyl phosphite, triphenyl phosphate, Tri-n-butyl phosphite and tri-n-butyl phosphate in particular

35 are preferred.

As other preferred examples of the present invention Solid substance used can be reaction products

3541953

of organomagnesium compounds, e.g. Grignard compounds, and mention titanium compounds. Examples of organomagnesium compounds include general ones Formulas RMgX, R-Mg and RMg (OR), where R is an organic radical and X is a halogen atom, and Ether complexes of these compounds, as well as substances obtained by modifying these organomagnesium compounds with other organometallic compounds such as organosodium, organolithium, organopotassium, organoboron,

10 organocalcium and organozinc, are available.

Examples of titanium compounds used in the present invention include halides, alkoxy halides, oxides and halogenated oxides of titanium. More concrete examples include compounds of tetravalent titanium such as Titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, Monoethoxytrichlorotitanium, diethoxydichlorotitanium, triethoxymonochlorotitanium, Tetraethoxy titanium, monoisopropoxytrichlorotitanium, diisopropoxy dichlorotitanium and tetraisopropoxy titanium; Titanium trihalides produced by the reduction of titanium tetrahalides with hydrogen, aluminum, titanium or organometallic compounds are available, as well as trivalent Titanium compounds, such as compounds obtained by reducing tetravalent alkoxy titanium halides with organometallic compounds are available. Among these titanium compounds, compounds of tetravalent titanium become particular preferred.

The following systems are typical examples of the solid substance used according to the invention: MgO-RX-TiCl. (JA-PS 3514/76), MgO-AlCl ₃ -TiCl ₄ (JA-OS 134789/79), Mg-SiCl ₄ -ROH-TiCl ₄ (JA-PS 23864/75), MgCl ₂ -Al (OR) ₃ -TiCl ₄ (JA-PS 152/76 and JA-PS 15111/77), MgCl ₂ -aromatic hydrocarbons-TiCl ₄ (JA-PS 48915/77), MgCl ₂ -SiCl ₄ -ROH-TiCl ₄ (JA- OS 10-6581 / 74), Mg (OOCR) ₂ -Al (OR) ₃ -TiCl ₄ (JA-PS 11710/77), MgCl-RX-TiCl. (JA-OS 42584/77), Mg-POCl ₃ -TiCl ₄ (JA-PS 153/76), MgCl ₂ -AlOCl-TiCl ₄

(JA-PS 15316/79), RMgX-TiCl ₄ (JA-PS 39470/75), MgCL ₂ -CH ₂ = CHSi (OR) ₃ -P (OR) ₃ -ROR-TiCl ₄ (JA-OS 7160 8 / 85) and MgCl ₂ -CH ₂ = CHSi (OR) ₃ -0 (OR) ₃ -TiCl ₄ (JA-OS 129203/84).

Examples of the organometallic compound (2) used according to the invention are organometallic compounds of metals from groups I to IV of the Periodic Table of the Elements, which are known as components of Ziegler catalysts. Specifically, organoaluminum compounds and organozinc compounds are preferred. More specific examples include organoaluminum compounds of the general formulas R-, ΑΙ, R-AlX, RAlX-, R ₂ AlOR, RAl (OR) X and R-Al ₅ X ₃ , in which the radicals R are the same or different and each represent an alkyl - Or aryl group with 1 to 20 carbon atoms and X is a halogen atom, as well as organozinc compounds of the general formula R “Zn, in which the radicals R are identical or different and each represent an alkyl group with 1 to 20 carbon atoms. Suitable examples are triethyl aluminum, triisobutyl aluminum, trihexyl aluminum, trioctyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, diethyl aluminum ethoxide, ethyl aluminum sesquichloride, diethyl zinc and mixtures of such compounds,

The amount of the organometallic compounds used according to the invention is not subject to any special limitation; however, it is usually in the range of 0.1 to 1000 moles per mole of the titanium compound.

Examples of the electron donor used according to the invention (3) Include carboxylic acid esters, ethers, ketones, alcohols and silicic acid esters. Are particularly preferred Silicic acid esters, such as tetraethoxysilane, monophenyltri-

35 ethoxysilane and monophenyltrimethoxysilane

The amount of the electron donor used according to the invention is not specifically limited, usually

3541953

however, it is in the range of 0.01 to 10 moles, preferably 0.1 to 5 moles, per mole of the organometallic compound.

5 (b) Branched C ₅ -C ₁₂ -C 3 C olefins

Examples of branched ones used according to the invention OL olefins with 5 to 12 carbon atoms include 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-cyclohexyl-1-butene, 3-phenyl-1-butene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 3-methyl-1-pentene, 3-methyl-1-hexene, 3,5,5-trimethyl-1-hexene, 3-ethyl-1-heptene, 3,7-dimethyl-1-octene, 4,6,6-trimethyl-1-heptene, allylcyclopentane, Allylcyclohexane, 2-allylnorbornene, allylbenzene, allyl toluene and allyl xylene. Above all, 4-methyl-1-pentene is particularly preferred.

(c) block copolymerization

The production process for the block copolymers according to the invention comprises at least two stages, a first stage (A) for producing the segment from the branched C _n . -C - ~ -oL oils fin, and a second stage (B) for the production of the segment from propylene. The order of performing steps (A) and (B) is not particularly limited, but it is desirable to perform step (A) first. A preferred production method for the block copolymer is described below.

In stage (A) the branched C ₅ -C ₁₂ -OL-olefin is polymerized in the presence or absence of a solvent. Examples of the solvent which can be used include saturated aliphatic hydrocarbons such as butane, pentane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane.

On the other hand, a bulk polymerization can also be carried out in which the branched C ^ -C. ^ - OC-oiefin
itself represents the solvent.

The polymerization temperature is not more than 50 ^° C., preferably 20 to 50 ^° C. If the polymerization temperature is outside this range, the heat resistance of the polymer formed is not improved.

The polymerization time is not subject to any particular restriction, usually it is in the range from 1 to 1000 minutes, preferably from 5 to 300 minutes.

The adjustment of the molecular weight can in certain
It can be done by changing the polymerization conditions such as the polymerization temperature and the molar ratio of the catalyst, but the addition of hydrogen to the polymerization system is for this purpose
more effective.
20th

After the polymerization, the branched oC-olefin remaining in step (A) is removed by a suitable method such as purging or distillation, and then the polymerization of propylene is carried out in step (B)
carried out.

The polymerization of propylene takes place in the vapor phase in the presence of an inert solvent or with application of propylene itself as a solvent. The same solvents can be used as the inert solvent as used in step (A).

The polymerization conditions in step (B) include
a temperature of not less than 50 ⁰ C; preferably 50 to 90 ^° C., in particular more than 50 ^° C., and a polymerization time that does not have any particular restriction
is subject, but usually in the range of 1 to 1000
Minutes, preferably from 5 to 300 minutes.

Polymerization temperatures outside this range lead to a reduced polymerization rate or to an impaired stereospecificity of the copolymer formed.
5

The molecular weight can be effectively adjusted by adding hydrogen.

If necessary, prepolymerization using propylene can be carried out before the polymerization in step (B). In this case, this prepolymerization is carried out for 5 to 120 minutes at a temperature of 20 to 50 ⁰ C. This treatment improves the particle properties of the polymer formed.

In order to describe the invention in greater detail, the following examples are given without these being restricted to the examples should be limited.

First, the measurement methods for various values in these examples will be described.

(1) melting point

25 A sample (about 10 mg) is placed in a differential

Scanning calorimeter (SSC / 580 DSC 20, manufactured by Seiko Denshi Kogyo KK) was used and held at 260 ^° C. for 5 minutes. Then, the temperature is reduced at a rate of 10 ° C / min to 40 ⁰ C and the sample was kept 5 minutes at this temperature. Then the temperature is increased at a rate of 10 ° C./min, and a peak occurring during heating is measured as a melting point.

35 (2) heat forming temperature

A sample made by a plate press method is used to determine the heat consumption

molding temperature measured under a load of 4.64 kg / cm ² according to ASTM D-648-70. A heat distortion tester manufactured by Toyo Seiki KK is used in the device.
5

(3) Flexural modulus of elasticity

Measured according to ASTM D-747-70 using a jig for measuring rigidity, Olsen type, manufactured by Toyo Tester Kogyo K.K.

(4) Proportion of branched oC-olefin

The content is measured by infrared spectroscopy, with a previous using an infrared spectroscopy

1 3
see method and 13 C-NMR spectrography obtained calibration curve is applied. For example, if 4-methyl-1-pentene is used as the branched oC-olefin, its content is obtained from the ratio AgT / Mgon ^and ^ ^{er E: i} - ^cn ~ curve (A means the absorption at the wave number (cm) with the specified values).

(5) Extraction residue after extraction with n-heptane

The residue (in percent by weight) after extraction of the powdery copolymer in boiling n-heptane for 7 hours in the Soxhlet extractor.

example 1
30th

(a) Preparation of the solid catalyst component

10 g (105 mmol) anhydrous magnesium chloride, 1.84 ml (8.8 mmol) vinyltriethoxysilane and 1.2 ml (4.6 mmol) triphenyl phosphite were placed in a stainless steel mill jar Steel having an internal volume of 400 ml and 25 stainless steel balls with a diameter each 1.27 cm and for 6 hours

ground in a ball mill under a nitrogen atmosphere at room temperature. Thereafter, 0.34 g (2 mmol) of diphenyl ether was added, followed by grinding in the ball mill under a nitrogen atmosphere for a further 16 hours. 5 g of the solid powder formed and 20 ml of titanium tetrachloride were placed in a 200 ml round bottom flask and ^{stirred at 100 °} C. for 2 hours under a nitrogen atmosphere. In order to remove excess titanium tetrachloride, the reaction mixture was then washed with hexane until titanium tetrachloride was no longer found in the washing liquid. Subsequent drying under reduced pressure gave a solid catalyst component containing 26 mg of titanium per gram.

(b) polymerization

A 3 liter stainless steel autoclave equipped with an induction stirrer was purged with nitrogen and 750 ml of 4-methyl-1-pentene and finally 2.5 mmoles of triethylaluminum, 1.4 mmoles of phenyltriethoxysilane and 50 mg of the above prepared solid catalyst component charged. Hydrogen was then passed in so that its partial pressure in the vapor phase was 0.05 kg / cm ² , and finally the temperature was increased to 50 ^° C. with stirring. The polymerization of 4-methyl-1-pentene was carried out for 15 minutes.

Thereafter, 4-methyl-1-pentene was flushed out of the polymerization system and 1500 ml of hexane was added, after which hydrogen was passed in so that its partial pressure in the vapor phase was 0.05 kg / cm ² . The temperature of the polymerization was raised to 70 ⁰ C. Propylene was then continuously introduced with the total pressure being kept at 7 kg / cm ² above atmospheric pressure while the polymerization was carried out for 15 minutes.

Excess propylene was then removed, the reaction mixture was cooled and the contents of the reactor were removed

and dried to obtain 86 g of a white polymer. This is the total amount of products including of the amorphous polymer.

The catalyst activity was 7400 g copolymer / g-Ti and the amount of the amorphous polymer soluble in the polymerization solvent was 4.8% by weight.

The properties of the copolymer thus obtained are shown in Table 1.

Table 1

example First stage Monomer Hydrogen-
Partial pressure
kg / cm ² temperature
⁰ C Time
min Second step Msncmeres Hydrogen-
Partial pressure
kg / on ² temperature
⁰ C Time
min 1 4-ifethyl
1-pentene 0.05 50 15th Propylene 0.05 70 15th 2 Il Il Il 120 Il Il Il 20th 3 Il ■ 1 Il Il Il Il Il 5 4th Il Il Il 300 Il Il 50 3 5 Il 0 Il 120 Il Il 70 25th 6th Il 0.05 Il 60 Il M. Il 10 7th Propylene Il
Il 45 30th 4-methyl
1-pentene Il 50 90 8th 4-Mathyl-
1-pentene Il 50 20th Propylene Il 70 20th 9 Il Il Il 30th ■ 1 Il • 1 35

• fr- CD

Table 1 (continued)

example Polymer-
yield
G Solvent-
soluble
Polymer
Wt% catalyst
activity,
g polymer /
g-Ti Intrinsic viscosity
number
dl / g n-ifeptan-
Extraction
Residue
Wt% Share of
4-M3thyl-
1-pentene
Wt% 1 86 4.8 74000 2.5 93.8 12.5 2 132 5.7 102000 2.8 91.6 22.5 3 74.7 5.8 58000 3.1 93.6 41.0 4th 63 6.0 48000 2.7 90.4 89.6 5 119 6.4 92000 3.4 92.3 18.5 6th 139 4.0 107000 2.1 91.2 34.0 7th 92.6 2.9 71000 2.2 91.3 20.0 8th 63 5.9 95500 2.5 90.2 18.5 9 101 8.4 51800 2.7 89.2 16.4

Table 1 (continued)

example Melting point
⁰ C Flexural elasticity
module
kg / cm ² 11200 Heat supply
shaping
temperature
⁰ C 1 161
240 11300 11400 123 2 240 11200 10700 128 3 152.5
238 10500 11600 i
106 4th ¹⁵⁶ ₂₄₀ 9900 87 5 ¹⁵⁸ ₂₄₀ 11500 129 6th 151.5
239 124 y
ί 7th ϊ
126 8th 159
239 125 9 160
239 124

Example 2

Using the catalyst prepared in Example 1, polymerization was carried out in the same manner as in Example 1 carried out with the modification that the polymerization time for 4-methyl-1-pentene to 120 minutes and which for propylene was set to 20 minutes. The results are shown in Table 1.

The copolymer thus obtained was hot-pressed to form a film, and this was measured by IR spectroscopy. The results are shown in the accompanying drawing.

If the polymer was subjected to fractionation using a decalin / butyl carbitol system, it was impossible, the propylene units and the 4-methyl-1-pentene units to separate from each other.

2 0 Examples 3 to 6

The procedure of Example 1 was repeated with the modification that the polymerization conditions in the in the manner shown in Table 1 were changed. The results are shown in Table 1.

Example 7

The polymerization was carried out in the same way as in Example 1, with the modification that the first stage of the polymerization process was the polymerization of propylene for 30 minutes at 45 ^° C. and the second polymerization stage was the polymerization of 4-methyl-1-pentene for 90 minutes at 50 ⁰ C was carried out. The results are shown in Table 1.

Comparative examples 1 and 2

Using the catalyst prepared in Example 1, the homopolymerization of propylene and the Homopolymerization of 4-methyl-1-pentene carried out. The polymerization conditions and the results of the polymerization are shown in Table 2.

Comparative Examples 3 and 4

Using the catalyst prepared in Example 1, copolymers containing 4-methyl-1-pentene were obtained of 3 percent by weight and 97 percent by weight. The polymerization conditions and the intrinsic

15 shafts of the copolymers are shown in Table 2.

Table 2

Comparison
example First stage Moncmeres Hydrogen-
Partial pressure
kg / cm ² temperature
⁰ C Time
min Second step Monomer Hydrogen-
Partial pressure
kg / on ² temperature
⁰ C Time
min 1 Propylene 0.05 70 60 - - - 2 4-methyl-
1-pentene Il 50 Il - - - - 3 Il Il Il 5 Propylene 0.05 70 60 4th Il Il Il 90 Propylene
(Partial
pressure
1 kg / an ² ) Il 50 3 5 Il Il 70 15th Propylene Il Il 60 6th Mixture of polypropylene (comparative example 1) /
Poly-4-methyl-1-pentene (comparative example 2)
in a weight ratio of 40/10

to cn co

Table 2 (continued)

Comparison
example Bolyner yield
G solvent
soluble
Polymer
Wt% catalyst
activity
g copolyireres /
g «Ti Gcenzvi skositats-
number
dl / g n-ifeptan-
Extraction
Residue
Wt% 1 220 1.0 161000 1.6 98.0 2 25.3 5.9 20000 2.9 95.3 3 136 3.8 105000 1.9 96.2 4th 42 7.9 32000 3.0 93.7 5 108 14.8 83000 2.1 91.3 6th - - 1.8 -

co cn co

Table 2 (continued)

Comparison
example Share of
4-M = ethyl
1-pentene
Wt% Melting point
⁰ C 240 Flexural modulus of elasticity
kg / cm ² Heat distortion temperature
⁰ C 1 - 165 164.5
240 12000 120 2 - 240 10,000 81 3 3 159
239 11000 120 4th 97 164.8
239 10,000 82 5 19th 11600 122 6th 20th 11500 124

Comparative example 5

Using the catalyst prepared in Example 1, polymerization was conducted in the same manner as in Example 1, except that the first polymerization for 15 minutes at 70 ° C and the second stage polymerization were carried out for 60 minutes at 50 ⁰ C. The copolymer formed contained 19 percent by weight of 4-methyl-1-pentene. The amount of the amorphous polymer soluble in the polymerization solvent was 14.8%, which is extremely large compared with the amount of this polymer in Example 2. The other properties are shown in Table 2.

15 Example 8

(a) Preparation of the solid catalyst component

10 g of anhydrous magnesium chloride and 0.5 ml of 1,2-dichloroethane were placed in a stainless steel vessel having a capacity of 400 ml and containing 25 stainless steel balls, each 1.27 cm in diameter, and the mixture was ground in the ball mill for 16 hours under a nitrogen atmosphere at room temperature. 5 g of the solid powder formed and 20 ml of titanium tetrachloride were placed in a 200 ml round bottom flask and ^{stirred for 2 hours at 100 °} C. under a nitrogen atmosphere. In order to remove excess titanium tetrachloride, the reaction mixture was then washed with hexane until titanium tetrachloride was no longer detectable in the washing liquid. Subsequent drying under reduced pressure gave a solid catalyst component containing, per gram, 13.2 mg of titanium.

ORIGINAL INSPECTED

(b) polymerization

The polymerization was carried out in the same manner as in Example 1 except that the above
produced solid catalyst component was used. The properties of the copolymer formed are in
Table 1 given.

Example 9
10

(a) Preparation of the solid catalyst component

9.5 g of a reaction product, which at 30O ⁰ C by thermal conversion of 40 g of magnesium oxide and 133 g

Aluminum trichloride and 1.7 g of titanium tetrachloride were placed in a stainless steel mill jar
Steel with an internal volume of 40 0 ml, the 25
Stainless steel balls with a diameter of
each 1.27 cm and in the ball mill for 16 hours under a nitrogen atmosphere at room temperature
ground. The solid powder formed contained 39% titanium
per gram.

(b) Polymerization 25

The polymerization was carried out in the same manner as in Example 1 except that the above
produced solid catalyst component was used. The properties of the copolymer formed are in
Table 1 shown.

Comparative example 6

40 g of polypropylene (which was prepared in Comparative Example 1) and 10 g of poly-4-methyl-1-pentene (which was prepared in Comparative Example 2) were added for 5 minutes
260 ⁰ C with the help of a kneading device (Plastograph,

manufactured by Toyo Seiki K.K.) in a nitrogen atmosphere kneaded to make a mixture. The properties of this mixture are shown in Table 2.

In the accompanying drawing, the IR spectrum is one Shown film made by hot pressing from a block copolymer according to the invention, produced in Example 2, was obtained. The numerical values in the drawing mean the wave number (cm).

Claims (7)

1. propylene / branched o ^ -olefin block copolymer, the at least one propylene block and at least one block from a branched © i - 01efin with 5 to 12 Contains carbon atoms, obtainable with the aid of a catalyst, which (1) a solid substance which at least Contains magnesium and titanium, (2) an organometallic compound and (3) an electron donor, wherein the block copolymer has the following properties; (a) it contains 5 to 95 percent by weight of the propylene units and 95 to 5 percent by weight of the units of the branched olefin having 5 to 12 carbon atoms;
(b) it has an intrinsic viscosity of 0.5 to 10 dl / g as measured in decalin at 135 ° C; (c) among the melting points measured by differential scanning calorimetry (DSC) it has at least one melting point which is not below 145 ^° C., and (d) it has a modulus of flexural rigidity of 8000 to 15000 kg / cm ² , measured according to ASTM Ό-ΊAT-IQ. 2. Block copolymer according to claim 1, characterized in that the branched oc-oiefin is 4-methyl-1-pentene is. 3. Process for the production of a block copolymer from propylene and a branched oc-olefin by block copolymerization of propylene with a branched oC-oiefin with 5 to 12 carbon atoms in the presence of a catalyst which (1) a solid substance containing at least magnesium and titanium, (2 ) comprises an organometallic compound and (3) an electron donor, characterized in that a polymerization comprising at least two stages is carried out, a temperature of not more than 50 ^° C. being maintained in the first polymerization stage and a temperature of not being maintained in the second polymerization stage less than 50 ⁰ C is carried out in the absence of the polymer used in the first stage, and a block copolymer is formed which has the following properties: (a) it contains 5 to 95 percent by weight of the propylene units and 95 to 5 percent by weight of the units of the branched oc-olefin with 5 to 12 Carbon atoms; (b) it has an intrinsic viscosity of 0.5 to 10 dl / g as measured in decalin at 135 ° C; (c) it possesses among those by differential scanning calorimetry (DSC) measured melting points at least one melting point that is not below 145 ° C, and (d) it has a modulus of flexular rigidity of 8000 to 15000 kg / cm ² , measured according to ASTM D-747-70. 4. The method according to claim 3, characterized in that in the first polymerization stage <3C-olefin block and in the second polymerization stage the propylene block is formed. 5. The method according to claim 4, characterized in that in the first polymerization stage CX-olefin in the presence or absence of a solvent is polymerized, then unreacted c <- olefin is removed from the polymerization system and finally the second stage of polymerization Supply of propylene is made in the presence or absence of a solvent. 6. The method according to any one of claims 3 to 5, 0 characterized in that the first polymerization is carried out at a temperature of 20 to 5O ⁰ C. 7. The method according to any one of claims 3 to 6, characterized in that the second polymerization stage is carried out at a temperature of 50 to 90 ^° C.