JP2695227B2 - Propylene block copolymer, block copolymer composition and method for producing the same - Google Patents

Description

The present invention relates to a block copolymer of propylene, a block copolymer composition, and a method for producing the same.

Specifically, it relates to a block copolymer obtained by copolymerization in the presence of alkenylsilane.

Further, the present invention relates to a block copolymer composition obtained by treating the copolymer under conditions in which a specific reaction occurs, and a method for producing the same.

[Prior Art] Polypropylene is a general-purpose resin having relatively excellent rigidity, but its impact resistance (especially at low temperatures) is poor.

As a solution to this problem, a block copolymer was developed that first polymerizes substantially with propylene alone, and then copolymerizes propylene and ethylene, and as a result, it is used as a resin with a very good balance of impact resistance and rigidity. Has been done.

Regarding the copolymerization of alkenylsilane and olefin, a random copolymer obtained by polymerizing alkenylsilane and ethylene in the presence of a transition metal compound and an organometallic compound is disclosed in US Pat. No. 3,223,686.

US Pat. No. 3,644,306 discloses a method of using an alkenylsilane to form a crosslinked polymer obtained by crosslinking a copolymer rubber of ethylene and propylene, a so-called vulcanized rubber.

These references relating to copolymerization of olefins and alkenylsilanes and crosslinking of the copolymers do not disclose that they are useful for resins having excellent impact resistance and rigidity as in the present invention.

[Problems to be Solved by the Invention] In order to obtain a polypropylene block polymer having an excellent balance of impact resistance and rigidity, the molecular weight and stereoregularity of the homopolymerized portion of propylene, especially the molecular weight of the copolymerized portion, ethylene Various proposals have been made to change the reaction ratio or composition distribution of propylene, but it is still inadequate, and it is desired to develop a block copolymer having excellent physical property balance.

[Means for Solving the Problem] As a result of earnest search for a block copolymer which has solved the above-mentioned problems, the present inventor has found the copolymer and the composition of the present invention, and completed the present invention.

That is, the present invention uses a catalyst which gives a highly stereoregular polypropylene composed of a transition metal catalyst component and an organometallic compound, and uses propylene alone or 6% propylene in the first stage.
Polymerize or copolymerize up to other olefins up to a total of 50
To 95 wt% and then copolymerizes an α-olefin essentially containing propylene and ethylene, which is a block copolymer having a general formula CH ₂ = CH- (CH ₂ ) _N SiH _m R _3-m (where n is 0 to 12, m is 1 to 3, R is a methyl group or a phenyl group) or the general formula CH ₂ = CH- (CH ₂ ) _n SiH _p Cl _{3 -p} (provided that n is 0 to 12 and p is 0 to 3) is coexistent and copolymerized with alkenylsilane.

The present invention also provides a propylene block copolymer composition obtained by treating the above-mentioned propylene block copolymer under conditions where a silanol bond is formed.

An example of the method for producing these propylene block copolymers in the present invention is shown below.

The catalyst composed of a transition metal catalyst component and an organometallic compound used for producing a copolymer may have a relatively high activity per catalyst as long as it is a catalyst system having high stereoregularity of the obtained polypropylene, and is not particularly limited. There is no.

Examples of the transition metal catalyst component include a catalyst obtained by reducing titanium tetrachloride with organic aluminum and further treating it with an electron donating compound, and a carrier type transition metal catalyst component obtained by supporting titanium halide on magnesium halide. There is no particular limitation as long as it provides a highly active and highly stereoregular polypropylene.

An extremely large number of supported transition metal catalyst components are known.

For example, (1) a magnesium compound, preferably an electron-donating compound selected from oxygen-containing organic compounds such as magnesium halides and esters of carboxylic acids, and, if necessary, a simple substance obtained by co-milling with a milling auxiliary agent is a titanium halide. (2) Magnesium compound, preferably magnesium halide or alkoxymagnesium, solubilized in a hydrocarbon solvent with alcohol or the like in the presence or absence of the above-mentioned electron donating compound and halogen If necessary, the composite of magnesium and titanium obtained by precipitation by contacting with titanium oxide is further subjected to contact treatment with the above-mentioned electron donating compound and / or titanium halide, Mag obtained by decomposition in the presence or absence of an electron-donating compound Siumu presence of containing support above ester, or a method of treatment with the titanium halide in the absence (for example, JP 58
-138710) and the like.

Examples of the organometallic compound used in combination with these transition metal catalyst components include organoaluminum compounds, organomagnesium compounds, organozinc compounds, organolithium, and the like,
In particular, organic aluminum and organic magnesium are preferable.

Specifically, trialkylaluminum and dialkylaluminum halide are preferable as the organoaluminum compound, and dialkylmagnesium and diallylmagnesium are preferable as the organomagnesium compound.

Further, in the polymerization, an electron donating compound can be used together as a stereoregularity improving agent, if necessary, and many of these compounds are already known. For example, the oxygen-containing organic compounds include esters, ethers, orthoesters, alkoxy silicons, and the nitrogen-containing compounds include amines and amides. Particularly, aromatic carboxylic acid esters, orthoalkyl esters, orthoaryl esters, 1 to A silicon compound having 4 alkoxy groups and 3 to 0 alkyl or aryl groups is preferable, and in these compounds, an alkyl group or aryl group having 1 to 20 carbon atoms is preferable.

In the present invention, the use ratio of each of the above-mentioned components can be selected in a considerably wide range, and 0.1 to 10,000 mol of the organometallic compound and 0.01 to 1,000 mol of the electron donating compound are used with respect to 1 mol of titanium in the transition metal component. It is common to do.

Further, in the present invention, the above-mentioned organometallic compound and / or electron donating compound may be added in the total amount used from the beginning, or may be added in the middle to control the polymerization rate and the like.

The polymerization method used in the method of the present invention, all known methods of polymerizing olefins can be used, usually, a solvent polymerization method of polymerizing in the presence of an inert medium, or a bulk polymerization method using propylene itself as a liquid medium, Alternatively, a gas phase polymerization method in which a liquid medium does not substantially exist may be used.

The polymerization conditions are not particularly limited as long as the catalyst is effectively used, but the polymerization temperature is usually room temperature to 150 ° C, preferably 4
The polymerization is carried out at a temperature of 0 to 100 ° C. and a polymerization pressure of atmospheric pressure to 50 kg / cm ² .

The polymerization method and the polymerization conditions are common to the first step and the subsequent copolymerization, but the polymerization method and the polymerization conditions may be changed during the polymerization.

In the present invention, a block copolymer in which propylene alone or propylene and other olefins up to 6% are polymerized or copolymerized in the first stage, and then propylene and an α-olefin essentially containing ethylene are copolymerized, The block copolymer of propylene is characterized in that alkenylsilane is allowed to coexist in at least a part of the step to copolymerize.

In the present invention, in the first stage, propylene alone or propylene and another olefin up to 6% are polymerized or copolymerized in the presence or absence of alkenylsilane.

Other olefins used in the first stage are up to 6% olefins such as ethylene and butene-1.

The molecular weight of the first-stage polypropylene or propylene copolymer is about 0.5 to 3 dl / g as the intrinsic viscosity (hereinafter abbreviated as [η]) measured with a 135 ° C. tetralin solution, and as the polymerization amount with respect to all polymers. Is 50 to 95 wt%.

In the present invention, the propylene and the α-olefin containing ethylene as an essential component are then copolymerized in the presence or absence of alkenylsilane.

There is no particular limitation on the reaction ratio or molecular weight of ethylene and propylene in the copolymerization reaction, or the number of stages in which the reaction ratio and the molecular weight are changed is not particularly limited, and it is known that a block copolymer of propylene and ethylene is used. The method is applied, and the reaction ratio is usually propylene /
Ethylene is about 10/90 to 95/5 weight ratio, [η] is about 0.5 to 20 dl / g as the molecular weight, and the polymerization amount is 50 to 5 wt% with respect to the total polymer.

As a modification of the above-mentioned polymerization method, the copolymer can be produced as follows.

That is, one method is to copolymerize propylene and alkenylsilane to obtain the total polymer.
It is a method for producing a copolymer in which the copolymerization is carried out so as to be 50 to 95 wt%, and then the copolymerization of ethylene, propylene and alkenylsilane is carried out to 5 to 50 wt%.

Further, the homopolymerization of propylene substantially 50% of the total polymer
〜95wt%, then propylene and alkenylsilane copolymerization 20〜0wt%, ethylene, propylene, alkenylsilane copolymer 50〜5wt%
% Is a copolymerization production method.

The propylene block copolymer of the present invention obtained by the stepwise polymerization method described above can be regarded as a polymer composition comprising a homopolymer or a copolymer produced in each polymerization step.

In the method of the present invention, alkenylsilane is added and copolymerized with α-olefin in at least a part of the step of the first stage polymerization and / or the subsequent copolymerization.

Here, as the alkenylsilane used in the copolymerization with at least one SiH bond is preferably used, for example, the general formula _{CH 2 = CH- (CH 2)} n SiH m R 3-m ( where, _n Is 0 to 12, _m is 1 to 3, R is a methyl group or a phenyl group) or a general formula CH ₂ = CH- (CH ₂ ) _n SiH _p Cl _3-p (where _n is 0 to 12, _p Represents an integer of 0 to 3), and specifically, vinylsilane, allylsilane, butenylsilane, pentenylsilane, or Si—H bond H of these monomers.
Examples thereof include compounds in which 1 to 2 of them are substituted with a methyl group or a phenyl group, or compounds in which 1 to 3 of Si-H bonds are substituted with chloro.

The step of adding an alkenylsilane and copolymerizing with an α-olefin may be any step of block copolymerization, a method of adding from the beginning of the first step or from the middle thereof, and propylene and ethylene following the first step are essential components. It is freely selected during the copolymerization process.

When it is added from the beginning of the first step or in the middle of the first step, a copolymer of propylene and alkenylsilane is mainly produced, but when unreacted vinylsilane goes to the next copolymerization step, some of it is α-olefin of the next step. A alkenylsilane copolymer is also formed. When alkenylsilane is added in the next step of the first step, a copolymer of ethylene, propylene and the like and alkenylsilane is produced.

After the completion of the first step, the unreacted alkenylsilane may or may not be removed.

The polymerization ratio of the alkenylsilane in the alkenylsilane copolymerization part is preferably about 0.01 to 10 wt% in the polymer in the part, and the content ratio of the alkenylsilane in the whole polymer is 0.005 to 5%, It is preferably 0.01 to 3%, and if it is less than this, the effect of improving the physical properties is small, and if it is more than this, the flowability of the composition becomes poor, which is not preferable.

Further, the block copolymer of the present invention can be mixed with a normal polyolefin containing no alkenylsilane within the above range of the alkenylsilane content.

The above-mentioned copolymer or composition obtained by the method of the present invention has good rigidity and impact resistance and can be used as a useful resin.

In the present invention, the above copolymer is then added to Si--H.
Further, the rigidity and the impact resistance can be further improved by treating under the condition that Si-Cl forms a silanol bond of Si-O-Si.

As a method of treating under conditions that generate a silanol bond, for example, it is already known in U.S. Pat.
Known methods are applied.

For this reason, the simplest method is to add the above copolymer to water and / or
Alternatively, it is a method of heat treatment with oxygen.

Here, the heating temperature is usually 50 ° C. or higher and the decomposition temperature of the polymer or lower.

At this time, a known catalyst effective for forming a silanol bond may be present, for example, an organic acid or a salt thereof, an organic base, an alkali metal or alkaline earth metal alkoxy compound, a hydroxide or an oxide. Examples thereof include various compounds known as siloxane condensation catalysts, particularly salts of alkali metal alkoxides, carboxylic acid tin and lead.

The above catalyst is generally added in an amount of 0.001 to 1% by weight, preferably 0.05 to 0.5%, based on the whole polymer.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

Example 1 i) Synthesis of transition metal catalyst component A A vibration mill equipped with four grinding pots with an inner volume of 4 containing 9 kg of steel balls having a diameter of 12 mm is prepared. 300 g of magnesium chloride, 60 ml of diisobutyl phthalate and 30 ml of 1,2-dichloroethane were added to each pot in a nitrogen atmosphere and pulverized for 40 hours.

300 g of the co-ground product was placed in a flask 5 and titanium tetrachloride (1.5) and toluene (1.5) were added, and the mixture was stirred at 100 ° C for 30 minutes, and then allowed to stand to remove the supernatant liquid twice.
Then, washing of the solid content with n-heptane 4 was repeated 10 times to obtain a transition metal catalyst component slurry.

The obtained transition metal catalyst component contained 2.6 wt% titanium and 4.6 wt% diisobutyl phthalate.

ii) Synthesis of Transition Metal Catalyst Component B 700 ml of kerosene, 10 g of magnesium chloride and 37 g of 2-ethylexanol were added to a round bottom flask having an internal volume of 2,
The mixture was stirred at 100 ° C. for 24 hours to completely dissolve. Then, 10 ml of diisobutyl phthalate was added thereto, and the mixture was stirred. Then, the mixture was gradually dropped into titanium tetrachloride 2 kept at 0 ° C. in a round bottom flask of No. 5 with stirring. Then slowly raise the temperature to 100 ° C for 1
Time processed. Then, the solid content alone was transferred to a 200 ml round bottom flask, 100 ml of titanium tetrachloride was further added, the mixture was stirred at 100 ° C., and finally the solid content was washed 10 times with n-heptane to obtain a transition metal catalyst component slurry. It was

This transition metal catalyst component B contained 3.5 wt% titanium and 5.2 wt% diisobutyl phthalate.

iii) Polymerization reaction 1 Under an atmosphere of nitrogen, 20 mg of transition metal catalyst component A, 0.06 ml of triethylaluminum and 0.03 ml of trimethoxyphenylsilane were placed in an autoclave with an internal volume of 5, then 1.8 kg of propylene was charged, and 3.3 Nl of hydrogen was added. 2 at 75 ° C
The polymerization reaction was performed for an hour. After completion of the reaction, unreacted propylene was purged and a part of the polymer was taken out and dried. Further, ethylene, propylene and vinylsilane were added in the presence of the remaining polypropylene and polymerization was carried out at 50 ° C. for 30 minutes. At this time, the partial pressure of propylene is 15 kg / cm ² , and the partial pressure of ethylene is 7 k.
g / cm ² , 20 g of vinylsilane and 0.2 Nl of hydrogen were added.
After the polymerization, unreacted gas was purged, the contents were taken out and dried, and 620 g of a copolymer was obtained.

The intrinsic viscosity [η] of the powder in a 135 ° C tetralin solution was 1.38dl / in the first homopolymerization part of propylene.
The total block copolymer was 2.05 dl / g, the ethylene content was 8.5 wt% and the vinylsilane content was 0.02 wt%.

The melt flow index (hereinafter abbreviated as MI) was measured after adding a known stabilizer and further adding 0.01 wt% of butyltin laurate to the powder and granulating.

An injection sheet with a thickness of 1 mm was made and the physical properties were measured. (Example 1-1) Next, after treating with boiling water for 2 hours, the following physical properties were measured. (Example 1-2) [Measurement temperature in parentheses] The results are shown in the table.

MI ASTM D1238 [230 ℃] Flexural rigidity ASTM D747-63 [20 ℃] Izod (notched) impact strength Kg cm / cm ASTM D256-56 [20 ℃, -10 ℃] DuPont impact strength Kg cm / 1/2 ″ Φ JIS K6718 [20 ° C., −10 ° C.] Comparative Example 1 Ethylene content was 8.6 w in the same manner as in Example 1 except that the copolymerization of ethylene and prolene was performed without using vinylsilane.
A t% block copolymer was obtained.

Results of measuring physical properties of the obtained copolymer (Comparative Example 1-1),
And physical property measurement results after treatment with boiling water (Comparative Example 1-2)
Example 2 The transition metal catalyst component B is used in place of the transition metal catalyst component A, the copolymerization reaction temperature is 40 ° C., and the ethylene partial pressure is 10 kg / cm ^2.
A copolymer having an ethylene content of 10.2 wt% and an allylsilane content of 0.02 wt% was obtained in the same manner as in Example 1 except that allylsilane was used instead of vinylsilane. The results of measuring the physical properties are shown in the table (the physical properties are measured only after the treatment with boiling water).

Comparative Example 2 A copolymer was obtained in the same manner as in Example 2 except that allylsilane was not used.

The results are shown in the table (physical properties are measured only after treatment with boiling water).

Example 3 50 mg of a commercially available highly active titanium trichloride catalyst (highly active titanium trichloride catalyst TGY-24 manufactured by Marubeni Solvay Co., Ltd.) and 1 ml of diethylaluminum chloride were placed in an autoclave having an internal volume of 5, and 1.5 kg of propylene was further added. Hydrogen 4.4
Nl was added, and the mixture was heated to an internal temperature of 70 ° C and polymerized for 2 hours.
After that, the unreacted propylene was purged and the ethylene partial pressure was adjusted to 10
kg / cm ² -G Propylene partial pressure 15 kg / cm ² -G, vinylsilane
20 g was added, 0.3 Nl of hydrogen was further added, and polymerization was carried out at 50 ° C. for 1 hour while maintaining a partial pressure of ethylene and propylene.

After the polymerization is completed, the unreacted monomer is purged to remove the powder.
570 g was obtained. The powder had an [η] of 2.65 dl / g, an ethylene content of 15.3 wt% and a vinylsilane content of 0.01 wt%.

The results of measuring the physical properties of this block copolymer in the same manner as in Example 1-2 are shown in the table (the physical properties are measured only after the treatment with boiling water).

Example 4 Example 4 was repeated except that 50 ml of vinyl monochlorosilane was added instead of vinyl silane during the copolymerization.

[Η] of the obtained copolymer was 2.70 dl / g, ethylene content was 15.2 wt%, vinylmonochlorosilane content was 0.1 wt%.
Met.

The results of measuring the physical properties of this block copolymer in the same manner as in Example 1-2 are shown in the table (the physical properties are measured only after the treatment with boiling water).

Example 5 An autoclave having an internal volume of 5 was charged with 20 mg of the transition metal catalyst component A obtained in Example 1, 0.06 ml of triethylaluminum and 0.03 ml of trimethoxyphenylsilane, and then 1.8 kg of propylene under a nitrogen atmosphere. More hydrogen 3.3
Nl was added and a polymerization reaction was carried out at 75 ° C for 2 hours. Then, 20 g of vinylsilane was injected under pressure, and the polymerization was continued for 10 minutes. After completion of this reaction, unreacted propylene was purged and a part of the polymer was taken out and dried. In the presence of the remaining polypropylene, add ethynylene, propylene and vinylsilane and
Polymerization was carried out for 40 minutes. At this time, the partial pressure of propylene is 15 kg.
/ cm ² -G, the partial pressure of ethylene was 7 kg / cm ² -G, 10 g of vinylsilane and 0.2 Nl of hydrogen were added. After polymerization, unreacted gas was purged, the contents were taken out and dried, and 670 g
Was obtained.

[Η] of powder is 2.14dl / g, ethylene content is 8.8wt
%Met. In addition, propylene homopolymerization was performed separately, and the ratio of each polymerization and the reaction ratio were calculated. As a result, propylene homopolymerization was about 80 wt%, propylene-vinylsilane copolymerization was about 5 wt%, vinylsilane content was 0.07 wt%, and propylene and ethylene. Polymerization of vinylsilane was about 15 wt%, vinylsilane content was 0.15 wt% and ethylene content was 55 wt%.

In addition, MI was measured after adding a known stabilizer and adding 0.01 wt% of butyltin laurate to the powder and granulating.

Furthermore, an injection sheet having a thickness of 1 mm was prepared, and the physical properties were measured in the same manner as in Example 1-1 (Example 5-1). After further treating with boiling water for 2 hours, the physical property values were similarly measured (Example 5). -2). The results are shown in Table 2.

Comparative Example 3 In the method of Example 5, propylene and ethylene were copolymerized in the same manner as in Example 5 without using vinylsilane.
The results are shown second. (Measurement of Physical Properties Only After Treatment with Boiling Water) Example 6 The transition metal catalyst component B was used in place of the transition metal catalyst component A, the reaction temperature for copolymerization was 40 ° C., and the ethylene partial pressure was 10 kg / cm ^2.
Same as Example 1 except that -G was used and allylsilane was used instead of vinylsilane. The ethylene content was 9.1 wt% and the vinyl silane content was 0.03 wt%. The measurement results of physical properties are shown in Table 2.

Comparative Example 4 A copolymer of propylene and ethylene was obtained in the same manner as in Example 6 except that allylsilane was not used.

The physical property measurement results are shown in Table 1 (physical properties are measured only after treatment with boiling water).

Example 7 50 mg of a commercially available highly active titanium trichloride catalyst (highly active titanium trichloride catalyst TGY-24 manufactured by Marubeni Solvay) and 1 ml of diethylaluminum chloride were placed in an autoclave having an internal volume of 5, and 1.5 kg of propylene was further added. Hydrogen 5.4
Nl was added, and the mixture was heated to an internal temperature of 70 ° C and polymerized for 2 hours.
Then, 10 g of vinylsilane was injected under pressure and polymerized for 20 minutes. After that, unreacted propylene was purged, and the ethylene partial pressure was 10 kg / c.
m ² -G propylene partial pressure of 15kg / cm ² -G, vinylsilane 20g
Was further added, and 0.3 Nl of hydrogen was further added, and polymerization was carried out at 55 ° C. for 1 hour while maintaining the partial pressure of ethylene and propylene. After the polymerization was completed, unreacted monomers were purged to obtain 565 g of powder.

The [η] of the powder is 2.25dl / g and the ethylene content is
The content was 10.4 wt% and the vinylsilane content was 0.02 wt%.

The results of measurement of physical properties are shown in Table 2 (physical properties are measured only after treatment with boiling water).

Example 8 Example 8 was repeated except that 50 ml of vinylmonochlorosilane was added during the copolymerization. [Η] of the obtained copolymer is
The content was 2.15 dl / g, the ethylene content was 10.8 wt%, and the vinylmonochlorosilane content was 0.1 wt%. The results of measurement of physical properties are shown in Table 2 (physical properties are measured only after treatment with boiling water).

[Effect of the Invention] The block copolymer of the present invention has extremely excellent physical properties and is industrially extremely valuable.

Claims (7)

(57) [Claims] 1. A propylene homopolymer or propylene and up to 6% of another olefin are polymerized or copolymerized in the first stage using a catalyst which gives a highly stereoregular polypropylene composed of a transition metal catalyst component and an organometallic compound, Overall 50 ~ 95wt
%, And then copolymerizes an α-olefin essentially containing propylene and ethylene, wherein the block copolymer has the general formula CH ₂ ═CH— (CH ₂ ) _n at least in part during the polymerization step. SiH _m R _3-m (where n is 0 to 12, m is 1 to 3, R is a methyl group or a phenyl group) or the general formula CH ₂ = CH- (CH ₂ ) _n SiH _p Cl _3-p (However, n shows 0-12, p shows 0-3) The block copolymer of propylene characterized by coexisting and copolymerizing the alkenylsilane shown by these. 2. A propylene homopolymer or propylene and up to 6% of another olefin are polymerized or copolymerized in the first stage using a catalyst which gives a highly stereoregular polypropylene composed of a transition metal catalyst component and an organometallic compound, Overall 50 ~ 95wt
%, And then copolymerizes an α-olefin essentially containing propylene and ethylene, wherein the block copolymer has the general formula CH ₂ ═CH— (CH ₂ ) _n at least in part during the polymerization step. SiH _m R _3-m (where n is 0 to 12, m is 1 to 3, R is a methyl group or a phenyl group) or the general formula CH ₂ = CH- (CH ₂ ) _n SiH _p Cl _3-p (However, n is 0 to 12 and p is 0 to 3) Copolymerization is carried out in the presence of an alkenylsilane represented by the following formula: a block copolymer of propylene is treated under the condition that a silanol bond is formed. A block copolymer composition of propylene obtained by the above. 3. A propylene block copolymer composition according to claim 2, wherein the propylene block copolymer according to claim 1 is heat-treated in the presence of water and / or oxygen. Method. 4. The copolymer according to claim 1, wherein in the first stage, propylene and alkenylsilane are copolymerized substantially as an α-olefin in an amount of 50 to 95 wt% of the total polymer, and then ethylene and propylene. Copolymerization of alkenylsilane
A block copolymer of propylene characterized by being carried out at 50 to 5 wt%. 5. The copolymer according to claim 1, wherein propylene homopolymerization is substantially carried out in the first stage by 50 to 95% of the total polymer.
A block copolymer of propylene, characterized in that the polymerization of propylene and alkenylsilane is carried out in an amount of 20 to 0% by weight, and further the copolymerization of ethylene, propylene and an alkenylsilane is carried out in an amount of 50 to 5% by weight. 6. The composition according to claim 2 or 3, wherein the propylene homopolymerization is substantially 50 to 95% of the total polymer.
A block copolymer composition of propylene characterized in that the polymerization of propylene and alkenylsilane is carried out in an amount of 20 to 0% by weight, and the copolymerization of ethylene, propylene and an alkenylsilane is carried out in an amount of from 50 to 5% by weight. 7. The composition according to claim 2 or 3, wherein in the first step, propylene and alkenylsilane are substantially copolymerized as an α-olefin in an amount of 50 to 95% by weight of the total polymer, and then ethylene and propylene. A block copolymer composition of propylene, wherein the copolymerization of alkenyl silane with 50 to 5 wt% is carried out.