KR920006448B1 - Block copolymer of propylene and a process for the production thereof - Google Patents

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Description

Block copolymer of propylene and its manufacturing method

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

In particular, it relates to block copolymers obtained in copolymerization in the presence of alkelylsilanes.

Moreover, it is related with the block copolymer obtained by processing this copolymer on the conditions which produce a specific reaction, and its manufacturing method.

Polypropylene is a general resin that is relatively rigid, but has poor impact resistance (especially at low temperatures).

As a solution to this problem, a block copolymer is first developed which polymerizes substantially propylene alone, and then copolymerizes propylene and ethylene, and thus is used as a resin having a very good balance of impact resistance and rigidity.

Copolymerization of alkenylsilanes and olefins is disclosed in US Pat. No. 3,223,686 for random copolymers obtained by polymerization of alkenylsilanes and ethylene in the presence of transition metal compounds and organometallic compounds.

A method of using alkenylsilane to make a crosslinked polymer crosslinked with copolymer rubber of ethylene and propylene, so-called vulcanized rubber, is disclosed in US Pat. No. 3,644,306.

In these documents concerning copolymerization of olefins and alkenylsilanes and crosslinking of these copolymers, it is not disclosed that they are useful for resins excellent in impact resistance and rigidity as in the present invention.

In order to obtain a block copolymer of polypropylene having excellent balance of impact resistance and rigidity, various modifications have been made to change the molecular weight, stereoregularity of the propylene homopolymerization, in particular, the molecular weight of the copolymerization, the reaction ratio of ethylene and propylene, or the composition distribution. There is still a need for development of block copolymers which are insufficient and excellent in physical property balance.

MEANS TO SOLVE THE PROBLEM This inventor discovered the copolymer of this invention as a result of earnestly searching about the block copolymer which solved the said subject, and completed this invention.

That is, the present invention is made by polymerizing α-olefin having propylene or propylene as a main component in the presence of a catalyst composed of a transition metal catalyst and an organometallic compound, and then copolymerizing α-olefin having propylene and ethylene as essential. And at least part of the polymerization step,

General formula CH ₂ = CH- (CH ₂ ) _n SiH _m R _3-m (wherein n represents 0-12, m represents 1-3, R represents an ethyl group, a phenyl group) or

Propylene characterized by copolymerizing ilkenylsilane represented by the general formula CH ₂ = CH- (CH ₂ ) _n SiH _p C1 _3-P (where n represents 0 to 12 and p represents 0 to 3). Of block copolymers.

The present invention also provides a method for producing a block copolymer of these propylene.

The catalyst composed of the transition metal catalyst and the organometallic compound used in the present invention may be a catalyst system having a relatively high activity per catalyst and a high stereoregularity of the polypropylene obtained. There is no particular limitation.

Examples of transition metal catalysts include catalysts obtained by reducing titanium tetrachloride to organoaluminum, an electron donating compound, and a carrier-type transition metal catalyst obtained by supporting titanium halides on magnesium halides. There is no restriction | limiting in particular as long as it gives polypropylene.

Many types of transition metal catalysts are known.

For example, (1) an electron donating compound selected from oxygen-containing organic compounds such as magnesium compounds, preferably magnesium halides and carboxylic acid esters, and, if necessary, a carrier obtained by co-pulverization with a grinding aid and contact treatment with titanium halides. Method (2) Magnesium compound, preferably magnesium halide or alkoxymagnesium, obtained by precipitating by contacting with a titanium halide and solubilizing with a hydrocarbon solvent in the presence or absence of the electron donor compound described above in a hydrocarbon solvent. A method of subjecting the composite of titanium and titanium to the above-mentioned electron donating compound and / or titanium halide as necessary, and (3) an alkyl-containing group obtained by decomposing alkyl magnesium or the like in the presence or absence of the above-mentioned electron donating compound. In the presence or absence of the above-mentioned ester How to process the halogenated titanium is deulsu that obtained by the like (for example, Japanese Unexamined Patent No. 58-138710 places).

As an organometallic compound used together with these transition metal catalysts, an organoaluminum compound, an organomagnesium compound, an organozinc compound, an organolithium etc. can be illustrated, Especially, organoaluminum and organomagnesium are preferable.

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

Moreover, at the time of superposition | polymerization, an electron donating compound can also be used together as a stereoregular homeostatic agent as needed, and also as these compounds. Many are already known. For example, there are esters, ethers, orthoesters, alkoxysilicones, etc. as the oxygen-containing organic compounds, and amines, amides, etc. as the nitrogen compounds, and in particular, esters of aromatic carboxylic acids, orthoalkyl esters, orthoaryl esters, 1-4. Silicon compounds having three alkoxy groups and 3 to 0 alkyl or aryl groups are preferable, and as those alkyl groups or aryl groups, those having 1 to 20 carbon atoms are preferable.

In the present invention, the application ratio of each component described above is selected in a very wide range, and it is preferable to use about 0.1 to 10,000 moles of organometallic compound and about 0.01 to 1,000 moles of electron donor association with respect to 1 mole of titanium in transition metal component. It is common.

In the present invention, the organometallic compound and / or the electron donating compound may be added in the total amount of the used amount from the beginning, or the polymerization rate or the like may be added in the middle.

As the polymerization method used in the method of the present invention, all known methods for polymerizing olefins can be used, and usually, a solvent polymerization method for polymerization in the presence of an inert medium or a lump polymerization method using propylene itself as a liquid medium. Or a vapor phase polymerization method in which substantially no liquid medium is present.

The polymerization conditions are not particularly limited as long as the catalyst is effectively used, but usually the polymerization temperature is from room temperature to 150 ° C, preferably from 40 to 100 ° C, and the polymerization pressure is carried out at atmospheric pressure from 50 kg / cm ² .

This polymerization method and polymerization conditions are common to the first step and subsequent copolymerization, but may be polymerized by changing the polymerization method and polymerization conditions in the middle of the polymerization.

In the present invention, in the first step, a block copolymer for polymerizing an α-olefin having propylene as a main component and then copolymerizing an α-olefin having propylene and ethylene as essential, wherein at least a portion of the alkenylsilane is added to the polymerization step. It is a propylene block copolymer characterized by coexistence and copolymerization.

In the present invention, in the first step, polymerization or copolymerization of α-olefins containing propylene as a main component is carried out in the presence or absence of alkenylsilane.

As the α-olefin used in the first step, not only propylene alone or propylene alone, but also other olefins such as ethylene and butene-1 up to about 6 wt% are used.

The molecular weight of the polypropylene or propylene copolymer of the first stage is about 0.5 to 3 dl / g as the ultimate viscosity (abbreviated as [η] below) measured by a 135 ° C. tetralin solution, and is 50 to about 50 to the total polymer. It is preferable that it is 95wt%.

In the present invention, copolymerization of? -Olefins containing propylene and ethylene as necessary is then performed in the presence or absence of alkenylsilane.

There is no restriction | limiting in particular about forming the reaction ratio or molecular weight of ethylene and propylene in a copolymerization reaction, or the reaction ratio and the step which changed the molecular weight in multiple stages, The well-known method performed by the block copolymer of propylene and ethylene In general, the reaction ratio is about 10/90 to 95/5 by weight ratio, the molecular weight [η] is about 0.5 to 20 dl / g, and the amount of polymerization to the whole polymer is preferably 50 to 5 wt%. .

As a modification of the said polymerization method, manufacture of copolymerization can also be performed as follows.

That is, one method is the manufacturing method of copolymerization which copolymerizes propylene and alkenylsilane so that it may become 50 to 95 wt% of a whole polymer, and then copolymerizes ethylene, propylene, and alkenylsilane by 5 to 50 wt%.

Substantially, homopolymerization of propylene is carried out to 50 to 95 wt% of the entire polymer, followed by 20 to 0 wt% copolymerization of propylene and alkenylsilane, and 50 to 5 wt% copolymerization of ethylene, propylene and alkenylsilane. It is a manufacturing method of a copolymer performed%.

The block copolymer of propylene of the present invention obtained by the stepwise polymerization method described above can be obtained as a polymer composition composed of homopolymers or copolymers produced in various synthesis steps.

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

Here, the alkenylsilane used for copolymerization is preferably one having at least one Si-H bond, for example,

General formula CH ₂ = CH- (CH ₂ ) _n SiH _m R _3-m (wherein n represents 0 to 2, m represents 1 to 3, R represents a methyl group and a phenyl group) or

General formula CH ₂ = CH- (CH ₂ ) _n SiH _p Cl _3-p (where n represents 0-12, p represents 0-3)

Alkenyl silane represented by is used, specifically, a compound in which 1 to 2 of H of the Si-H bonds of vinyl silane, aryl silane, butenyl silane, fetenyl silane, or monomers thereof are substituted with a methyl group or a phenyl group, or The compound etc. which 1-3 substituted Si-H bonds are substituted by chlor are mentioned.

The step of adding alkenylsilane and copolymerizing with the α-olefin may be any step of block copolymerization, and the method of adding at the beginning of the first step or in the middle of the step, following the first step to produce propylene and ethylene as essential components. Copolymerization process to be selected freely.

At the beginning or in the middle of the first step, mainly copolymers of propylene and alkenylsilanes are produced, but if unreacted vinylsilanes go to the polycopolymerization process, some of the α-olefins and alkenyls of the next process Copolymers of silanes are also produced. The addition of alkenylsilanol in the next step of the first step produces a copolymer of ethylene, propylene and the like with alkenylsilane.

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

As the polymerization ratio of the alkenylsilane in the alkenylsilane co-polymerization portion, the polymerization ratio of the alkenylsilane in this portion is preferably about 0.01 to 10 wt%, and the content ratio of the alkenylsilane in the prepolymer is preferably 0.005 to 5%. It is 0.01 to 3%, and below this, the effect of a physical property improvement is small, and beyond this, the flowability of a composition becomes bad and it is unpreferable.

Moreover, the block copolymer of this invention and the polyolefin which does not contain a normal alkenylsilane can also be mixed and used in the range of the content rate of the said alkenylsilane.

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

In the present invention, the copolymer is subsequently treated under conditions in which Si-H and / or Si-Cl generate a silanol bond of Si-O-Si, thereby further improving rigidity and impact resistance. .

As a method for treating under conditions for producing silanol bonds, for example, US Pat. No. 3,644,306 and the like are already known, and a known method is applied.

The easiest way to do this is by heating the copolymer with water and / or oxygen.

Here, as heating temperature, it is 50 degrees C or more normally and below the decomposition temperature of a polymer.

In this case, a compound selected from an organic acid or a salt thereof, an organic base, or an alkoxy compound of an alkali metal or an alkaline earth metal, or a hydroxide or an oxide, which may exist a known catalyst effective for forming a silanol bond, that is, As the siloxane condensation catalyst, various known compounds, in particular, salts such as alkoxides of alkali metals, tin of carboxylic acids, and lead can be exemplified.

The catalyst is generally added at 0.001 to 1% by weight, preferably 0.05 to 0.5%, based on the total polymer.

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

Example 1

i) Synthesis of Transition Metal Catalyst A

Prepare a vibrating mill equipped with 4 grinders with a volume of 4 liters containing 9 kg of steel balls with a diameter of 12 mm. 300 g of magnesium chloride, 60 l of diisobutyl phthalate, and 30 ml of 1,2-dercroethane were added to each pot in a nitrogen atmosphere and ground for 40 hours.

300 g of the co-pulverized product was placed in a 5 l flask, and titanium tetrachloride 1.51 and toluene 1.51 were added, followed by stirring at 100 ° C. for 30 minutes, followed by two steps of removing the supernatant liquid, followed by n. Washing the conjugate with 4 l of heptane was repeated 10 times to obtain a transition metal catalyst slurry.

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

ii) Synthesis of Transition Metal Catalyst B

700 ml of kerosene, 10 g of magnesium chloride, and 37 g of 2-ethylhexanol were added to a 2 l round bottom flask, which was stirred at 100 ° C for 24 hours to dissolve completely. After stirring and stirring 10 ml of disobutyl phthalate in it, it stirred in 2 liters of titanium tetrachloride maintained at 0 degreeC in a 5 l round bottom flask, and was dripped gradually. Then, the temperature was slowly raised and treated at 100 ° C. for 1 hour. Subsequently, the solid powder was transferred to a 200 ml round bottom flask, and 100 ml of titanium tetrachloride was added, stirred at 100 ° C., and finally the solid was washed 10 times with n-heptane to obtain a transition metal catalyst slurry.

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

iii) Polymerization 1

Into a 5 liter autoclave, 20 mg of transition metal catalyst A, 0.06 l of triethylaluminum and 0.03 ml of trimethoxyphenylsilane were added under nitrogen atmosphere, followed by charging 1.8 kg of propylene, followed by addition of 3.3 Nl of hydrogen and 75 DEG C. The polymerization was carried out for 2 hours at. After the reaction was completed, unreacted propylene was purged, and one part of the polymer was taken out and dried. In addition, ethylene, propylene, and vinylsilane were added in the presence of the remaining polypropylene, and polymerization was performed at 50 ° C for 30 minutes. The partial pressure of propylene was 15 kg / cm ² , the partial pressure of ethylene was 7 kg / cm ² , 20 g of vinylsilane and 0.2 Nl of hydrogen were added. After polymerization, the unreacted gas was purged, the contents were taken out and dried to obtain 620 g of a copolymer.

The ultimate viscosity [η] of the powder in 135 ° C. tetralin solution is 1.38 dl / g in the first propylene homopolymerization section, 2.05 dl / g in the entire block copolymer, ethylene content of 8.5 wt%, vinylsilane content Was 0.02wt%.

The melt flow index (hereinafter abbreviated as MI) was measured by adding an air stabilizer, and adding butyltin laurate to the powder by adding 0.01 wt% to granules.

An injection sheet having a thickness of 1 mm was made and physical properties were measured (Example 1-1).

Subsequently, after treating with boiling water for 2 hours, the following physical property values were measured (Example 1-2).

[Measured temperature in parentheses]

The results are shown in the table.

HI: ASTM D128 [230 ℃]

Bending Stiffness: ASTM D747-63 [20 ℃]

Izod (Notch) Impact Strength Kg cm / cm ² ASTM D256-56 [20 ℃, -10 ℃]

Tupon impact strength Kg cm / 1/2 "Ф JIS K6718 [20 ℃, -10 ℃]

Comparative Example 1

The copolymerization of ethylene and propylene without polymerization of vinylsilane was carried out in the same manner as in Example 1 to obtain an ethylene content of 8.6 wt% block copolymer.

Table 1 shows the measurement results of the obtained copolymers (Comparative Example 1-1) and the measurement results of physical properties after treatment in boiling water (Comparative Example 1-2).

Example 2

The conversion catalyst B was used instead of the transition metal catalyst A, and the reaction temperature of the copolymerization was 40 ° C., the ethylene partial pressure was 10 kg / cm ² , and the ethylene content was 10.2 wt. %, An arylsilane content of 0.02 wt% was obtained. The results of measuring the physical properties are shown in the table (the physical properties are measured only after treatment in boiling water).

Comparative Example 2

A copolymer was obtained in the same manner as in Example 2 except that no arylsilane was used.

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

Example 3

50 mg of a commercially available high activity titanium trichloride catalyst (TGY-24 high activity titanium chloride catalyst TGY-24 from Marubenisol Mesa, Japan) and 1 ml of diethylaluminum chloride were placed in an autoclave of 5 liters in total, and 1.5 kg of propylene was added thereto. Subsequently, 4.4Nl of hydrogen was added, and it heated, and internal pressure was 70 degreeC and it pressure-reduced for 2 hours. Then, unreacted propylene is purged, ethylene partial pressure 10 kg / cm ² -G propylene partial pressure 15 kg / cm ² -G and 20 g of vinylsilane are added, and 0.3 Nl of hydrogen is added to separate the partial pressure of ethylene and propylene at 50 ° C. The polymerization was carried out for 1 hour while maintaining.

After completion of the polymerization, unreacted monomer was diffused to obtain 570 g of powder.

[Η] of the powder is 2.64dlg, the ethylene content is 15.3wt% and the vinylsilane content is

0.01 wt%.

The result of measuring physical properties similarly to Example 1-2 using this block copolymer is shown in a table. (The physical property is measured only after processing in boiling water).

Example 4

The same procedure as in Example 3 was carried out except that 50 ml of vinyl monochlorosilane was added instead of vinylsilin during copolymerization.

[Eta] of the obtained copolymer was 2.70 dl / g, the ethylene content was 15.2 wt%, and the content of vinyl monochlorsilane was 0.1 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 were measured only after treatment in boiling water).

Example 5

Into a 5 liter autoclave, 20 mg of the transition metal catalyst A obtained in Example 1, 0.06 ml of triethylaluminum and 0.03 ml of trimethoxyphenylsilane were added under an atmosphere of nitrogen, followed by injecting 1.8 kg of propylene, followed by 3.3 Nl of hydrogen. Was added and polymerization was carried out at 75 ° C. for 2 hours. Next, 20 g of vinylsilane was press-fitted and then polymerized for 10 minutes. After the completion of the reaction, unreacted propylene was purged and a part of the polymer was taken out and dried.

In the presence of the remaining polypropylene, ethylene, propylene, and vinylsilane were added, and polymerization was carried out at 60 ° C. for 40 minutes. At this time, the partial pressure of propylene was 15kg / cm ² -G, the partial pressure of ethylene was 7kg / cm ² -G, 10g of vinylsilane and 0.2Nl of hydrogen were added.

After polymerization, unreacted gas was purged, the contents were taken out and dried to obtain 670 g of a copolymer.

[Eta] of the powder was 2.14 dl / g and the ethylene content was 8.8 wt%. In addition, propylene homopolymerization was performed separately, and the respective polymerization ratios and reaction ratios were calculated. As a result, the polymerization of propylene alone was about 80 wt%, the copolymerization of propylene and vinyl silane was about 5 wt%, and the vinylsilane content 0.07 wt%, propylene and ethylene The polymerization rate of vinylsilane was about 15 wt%, the vinylsilane content 0.15wt%, and the ethylene content 55wt%.

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

Further, an injection sheet having a thickness of 1 mm was made, and the physical properties were measured in the same manner as in Example 1-1 (Example 5-1), and further treated in boiling water for 2 hours, and then the physical properties were measured in the same manner. (Example 5-2) The results are shown in the second table.

Comparative Example 3

In the method of Example 5, copolymerization of propylene and ethylene was carried out as in Example 5 without using vinylsilane. The results are shown in Table 2. (Measured properties only after treatment in boiling water)

Example 6

The transfer catalyst B was used instead of the transition metal catalyst A, and the reaction temperature of the copolymerization was 40 ° C, ethylene fraction 10 kg / cm ² -G, and aryl silane instead of vinyl silane was used in the same manner as in Example 1. Ethylene content 9,1 wt% vinylsilane content 0.03 wt%. The measurement results of the 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 no arylsilane was used.

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

Example 7

50 mg of a commercially available high activity titanium trichloride catalyst (TGY-24 high activity titanium chloride catalyst TGY-24 manufactured by Marbeni Solbe, Japan) and 1 ml of diethylaluminum chloride were added to an autoclave of 5 liters in total, and 1.5 kg of propylene was added. Subsequently, 5.4 Nl of hydrogen was added thereto, and the mixture was heated and polymerized at an internal temperature of 70 ° C. for 2 hours. Thereafter, 10 g of vinylsilane was press-fitted and polymerized for 20 minutes. The unreacted propylene is then purged, ethylene partial pressure 10 kg / cm ² -G propylene partial pressure 15 kg / cm ² -G and 20 g of vinylsilane are added, and 0.3Nl-hydrogen is added to the partial pressure of ethylene and propylene at 55 ° C. The polymerization was carried out for 1 hour while maintaining. After completion of the polymerization, unreacted monomer was purged to obtain 565 g of powder.

[Η] of the powder is 2.25dl / g, ethylene content is 10.4wt%, vinylsilane content

0.02 wt%.

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

Example 8

The same procedure as in Example 7 was carried out except that 50 ml of vinyl monochlorosilane was added during the copolymerization. [Eta] of the obtained copolymer was 2.15 dl / g, the ethylene content was 10.8 wt%, and the content of vinyl monochlorsilane was 0.1 wt%. The measurement results of the physical properties are shown in Table 2 (the physical properties are measured only after treatment in boiling water).

TABLE 1

TABLE 2

The block copolymer of the present invention is very excellent in physical properties and very valuable industrially.

Claims (3)

Block copolymer which polymerizes propylene alone or 6wt% of propylene and other α-olefins in the first step by using a catalyst composed of a transition metal catalyst and an organometallic compound, and then copolymerizes an α-olefin including propylene and ethylene. At least part of the process of polymerization General formula CH ₂ = CH- (CH ₂ ) _n SiH _m R _3-m (wherein n is 0 to 12, m is 1 to 3, R represents a methyl group or a wasteyl group) or General formula CH ₂ = CH- (CH ₂ ) _n SiH _p Cl _3-p (where n represents 0-12, p represents 0-3) Block copolymer of propylene, characterized in that the co-existing copolymerization of alkenylsilane represented by. The method according to claim 1, wherein the public company performs copolymerization of propylene and alkenylsilane as the α-olepin in the first step of 50 to 95 wt% of the prepolymer, and then copolymerization of ethylene to propylene and alkenylsilane. Block copolymer of propylene, characterized in that 50wt%. 2. The copolymer according to claim 1, wherein the homopolymerization of propylene in the first step is carried out at 50 to 95 wt% of the prepolymer, followed by polymerization at 20 to 0 wt% of propylene and alkenylsilane, and ethylene and alkenyl. A block copolymer of propylene, characterized in that 5 to 50 wt% of copolymerization with silane is performed.