JP3165732B2 - Method for producing propylene copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a propylene-based copolymer which is excellent in flexibility and processability and has no stickiness despite containing many monomer units based on ethylene.

[0002]

BACKGROUND OF THE INVENTION Olefin-based thermoplastic elastomers have excellent flexibility, low specific gravity and high weather resistance. Therefore, various industrial parts including automobile parts such as bumpers are used. Widely used for home electric parts and the like. The olefin-based thermoplastic elastomer is generally produced by blending ethylene-propylene rubber (hereinafter, referred to as EPR) or ethylene-propylene terpolymer (hereinafter, referred to as EPDM) with a thermoplastic resin such as polypropylene. Then
Attempts have been made to produce an EPR component or EPDM component and a thermoplastic resin component such as polypropylene by polymerization at once using a highly active titanium catalyst.

However, when an olefin-based thermoplastic elastomer is produced by the above-mentioned polymerization, a large amount of low molecular weight components are produced as by-products and are dissolved in the solvent, and the viscosity of the polymerization solution is significantly increased, resulting in agitation efficiency and removal of heat of polymerization. The effect was reduced, and the polymer particles adhered to each other to form a lump, which made separation from the polymerization tank difficult.

Therefore, in order to solve the above-mentioned problems by increasing the molecular weight, and to prevent a decrease in moldability due to the increase in the molecular weight, the obtained polymer having a large molecular weight is replaced with an organic peroxide. There is proposed a method of degeneration. That is, JP-A-58-32610 discloses that after polymerizing an ultrahigh molecular weight propylene-ethylene copolymer having an ethylene composition of 5 to 15% by weight and a melt flow rate of 0.01 to 0.3 g / 10 min. , A method of degrading with an organic peroxide.

[0005] However, when the present inventors conducted a supplementary test of the above method, it was found that an ultrahigh molecular weight propylene-ethylene copolymer was obtained in the form of particles. There is a problem that stickiness occurs on the surface, and a blocking phenomenon occurs on a film or sheet, and the film or sheet cannot be peeled off.

[0006]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of examining the cause of the problem of the method of degrading the ultrahigh molecular weight propylene-ethylene copolymer with an organic peroxide, the ultrahigh molecular weight propylene-ethylene copolymer contains a large amount of low molecular weight, It has been found that this low molecular weight component is decomposed by the organic peroxide to a further lower molecular weight, which causes stickiness of the molded article.

The inventors of the present invention have studied a method for producing an olefin-based thermoplastic elastomer which is excellent in flexibility and processability and has no stickiness of a molded product. By melting and kneading with an organic peroxide using one having a low molecular weight component, it is thought that the above problem can be solved, and also succeeded in synthesizing an ultra high molecular weight propylene-ethylene copolymer having a low low molecular weight component, The present invention has been proposed.

That is, the present invention relates to a block copolymer comprising a polypropylene component and a propylene-ethylene random copolymer component, wherein the polypropylene component comprises 3-50.
% Of the propylene-ethylene random copolymer component is 93 to 50% by weight, and the propylene-ethylene random copolymer component has 15 monomer units based on ethylene.
-80 mol%, 85 units of propylene-based monomer units
A propylene-based block copolymer composed of a random copolymer containing 20 mol% and having a molecular weight of 10,000 or less in a proportion of 1.0% by weight or less and a weight average molecular weight of 1,000,000 to 7,000,000. And melt indexing of an organic peroxide and a melt index of 0.1-100.
This is a method for producing a propylene-based copolymer in g / 10 minutes.
The present invention also provides a melt index of 0.1, wherein the propylene-based block copolymer and the organic peroxide are melt-kneaded in the presence of a compound having two or more radically polymerizable groups in one molecule. It is also a method for producing a propylene-based copolymer of 1 to 100 g / 10 minutes.

In the present invention, propylene as a raw material
Ethylene copolymer (hereinafter simply referred to as “HMPE copolymer”) is a polypropylene component and propylene-
It is a block copolymer composed of an ethylene random copolymer component.

The respective proportions of the polypropylene component and the propylene-ethylene random copolymer component are 3 to 50% by weight for the polypropylene component and 7 to 50% by weight for the propylene-ethylene random copolymer component.

When the content of the polypropylene component is less than 3% by weight, especially less than 1% by weight, the strength and heat resistance of the molded article comprising the obtained propylene copolymer are reduced. If the proportion of the polypropylene component exceeds 50% by weight, the low-temperature impact resistance of the molded article is reduced, and if it is 60 parts by weight or more, the intended propylene-based copolymer cannot be obtained. The polypropylene component is preferably in the range of 3 to 50% by weight in consideration of mechanical strength, heat resistance, low-temperature impact resistance, and the like.
When the content is 0% by weight or less, the flexibility is good.

Further, the content of the ethylene-propylene random copolymer component is 50 to 93% by weight. 50 of the above ingredients
When the amount is less than 40% by weight, particularly less than 40% by weight, the low-temperature impact resistance is poor, and when it exceeds 97% by weight, especially 99% by weight, the mechanical properties such as the strength and heat resistance of the molded product are inferior.
The ethylene-propylene copolymer component is preferably in the range of 50 to 97% by weight in consideration of low-temperature impact resistance, strength and heat resistance.

The HMPE copolymer used in the present invention includes:
Polypropylene component, one or more of the propylene-ethylene random copolymer component, as long as the physical properties of the block copolymer are not inhibited, a small amount of other α-olefin,
For example, it may be contained by copolymerization in a range of 5 mol% or less.

The HMPE copolymer used in the present invention comprises a so-called block copolymer having a polypropylene component and a propylene-ethylene random copolymer component arranged in one molecular chain, a polypropylene component and a propylene-ethylene random copolymer. It is considered that the molecular chains of the copolymer components alone are mixed microscopically to such an extent that they cannot be achieved by mechanical mixing.

The content ratio of each of the monomer units based on ethylene and the monomer units based on propylene in the propylene-ethylene random copolymer component is as follows:
It is 15 to 80 mol%, preferably 15 to 60 mol%, more preferably 20 to 50 mol%, of a monomer unit based on ethylene. 85 to 20 monomer units based on propylene
Mol%, preferably 85 to 40 mol%, more preferably 80 to 50 mol%. When the content ratio of the monomer unit based on ethylene is less than 15 mol% and the content ratio of the monomer unit based on propylene is more than 85 mol%, the flexibility and impact resistance of the molded product are not sufficient, which is preferable. Absent. On the other hand, the content ratio of the monomer unit based on ethylene is 8
When the content exceeds 0 mol% and the content of the monomer unit based on propylene is less than 20 mol%, the strength and heat resistance of the molded product are not sufficient, which is not preferable.

The HMPE copolymer used in the present invention has a weight average molecular weight of 600,000 or more, and is generally 1,000,000 to 7,000,000.
It has a molecular weight in the range of 100,000, preferably 1.5 to 3 million. If the weight average molecular weight is less than 600,000, polymer particles having a high bulk specific gravity cannot be obtained in the above-mentioned ethylene composition, and only a bulk polymer can be obtained due to adhesion between the polymer particles. The weight average molecular weight in the present invention is a value measured by gel permeation chromatography (hereinafter simply abbreviated as GPC) and converted based on a calibration curve obtained with polystyrene.

Further, the HMPE copolymer used in the present invention has an extremely small amount of low molecular weight components. That is, in the elution curve measured by GPC, the HMPE copolymer used in the present invention has a component having a molecular weight of 10,000 or less at 1.0% by weight of the whole.
It is preferably at most 0.5% by weight or less. For this reason, even if it is decomposed by an organic peroxide, the amount of low molecular weight components in the polymer after decomposition is extremely small.

The HMPE copolymer used in the present invention is obtained as a powder by polymerization according to the production method described below. Bulk density of the powder is at 0.35 g / cm ³ or more, take a value in the range of usually 0.35~0.50g / cm ^3.

The HMPE copolymer used in the present invention is obtained as a powder having a relatively narrow particle size distribution. That is, HMPE
Powder of the copolymer has an average particle (hereinafter abbreviated as D ₅₀₎ of 10
0 μm ≦ D ₅₀ ≦ 800 μm, and particles of 100 μm or less are 1% by weight or less, and particles of 1000 μm or more are 1% by weight or less.

The HMPE copolymer used in the present invention may be obtained by any method, but the following method is particularly preferably employed.

The following components A, B and C A. Titanium compound B. Organoaluminum compound C. General formula [I] R _n Si (OR ′) _4-n [I] [where R and R ′ are the same or different hydrocarbon groups, and n is an integer of 1 to 3. The propylene prepolymerization was carried out in multiple stages in the presence of the organosilicon compound represented by the formula [1] and using a different organosilicon compound in each prepolymerization stage. E. Titanium-containing polypropylene obtained by prepolymerization B. Organoaluminum compound similar to B above In this method, propylene and ethylene are copolymerized in the presence of the same organosilicon compound as in C. Titanium compound [A] used in the prepolymerization method
A compound known to be used for the polymerization of olefins is employed without any limitation. In particular, a titanium compound having high catalytic activity containing titanium, magnesium and halogen as components is preferable. Such a titanium compound having high catalytic activity is obtained by supporting a titanium halide, particularly titanium tetrachloride, on various magnesium compounds. As a method for producing this catalyst, a known method is employed without any limitation.
For example, JP-A-56-155206, JP-A-56-136806, JP-A-57-3
4103, 58-8706, 58-83006, 58-138708, 58-183
709, 59-206408, 59-219311, 60-81208, 60-81
209, 60-186508, 60-192708, 61-211309, 61-2
71304, 62-15209, 62-11706, 62-72702, 62-10
The method shown in 4810 is adopted. In particular,
For example, a method of co-milling titanium tetrachloride with a magnesium compound such as magnesium chloride, a method of co-milling titanium halide and a magnesium compound in the presence of an electron donor such as alcohol, ether, ester, ketone or aldehyde, Alternatively, a method of contacting a titanium halide, a magnesium compound and an electron donor in a solvent may be used.

Next, as the organoaluminum compound [B], a compound known to be used for the polymerization of olefins is employed without any limitation. For example, trimethyl aluminum, triethyl aluminum, tri-n propyl aluminum, tri-n butyl aluminum, tri-i butyl aluminum, tri-n hexyl aluminum, tri-
Trialkylaluminums such as n-octylaluminum and tri-ndecylaluminum: diethylaluminum monohalides such as diethylaluminum monochloride: alkylaluminum halides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, and ethylaluminum dichloride. Can be Other alkoxy aluminums such as monoethoxy diethyl aluminum and diethoxy monoethyl aluminum can be used.

Among them, triethylaluminum is most preferred. The amount of the organoaluminum compound used in each prepolymerization stage is Al / T with respect to the Ti atom in the titanium compound.
i (molar ratio) is 1 to 100, preferably 2 to 20.

Further, as the organosilicon compound [C], the compound represented by the above general formula [I] is employed without any limitation.
R and R 'in the general formula [I] are hydrocarbon groups such as an alkyl group, an alkenyl group, an alkynyl group and an aryl group. Examples of the organosilicon compound suitably used in the present invention are as follows. For example, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethylethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane Silane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, 6-triethoxysilyl 2-norbornene and the like.

The amount of the organosilicon compound used in each of the prepolymerization stages is determined by the ratio of Si / Ti to Ti atom in the titanium compound.
(Molar ratio) 0.1 to 100, preferably 0.5 to 10
It is.

In the present invention, the above titanium compound
In addition to [A], the organoaluminum compound [B] and the organosilicon compound [C], the following general formula [II] R ″ -I [II] wherein R ″ is an iodine atom or a hydrocarbon group. The use of an iodine compound [D] represented by the formula
Not only the bulk specific gravity of the particles of the PE copolymer becomes large, but also the amount of low molecular weight components having a molecular weight of 10,000 or less is remarkably reduced, and the stickiness of a molded article after decomposition with an organic peroxide is improved. .

In the above general formula [II], the hydrocarbon group represented by R "is a hydrocarbon group such as an alkyl group, an alkenyl group, an alkynyl group or an aryl group. An iodine compound which can be suitably used in the present invention. Specific examples thereof include the following: iodine, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, iodobenzene, p-iodotoluene, etc. Among them, methyl iodide, iodine The amount of the iodine compound used in each prepolymerization step is I / T based on the titanium atom in the titanium compound.
i (molar ratio): 0.1 to 100, preferably 0.5 to 100
50.

In the present invention, the term "preliminary polymerization carried out in multiple stages" refers to the above [A], [B], [C], and if necessary.
Propylene is prepolymerized in the presence of each component of [D], and the obtained titanium-containing polypropylene is further polymerized in the presence of the above components [B], [C] and, if necessary, each component of [D]. This refers to repeating polymerization. The prepolymerization is preferably performed in a range of 2 to 5 times. The above-mentioned components used in each prepolymerization may be added sequentially or may be used as a mixture. The polymerization amount of propylene in each prepolymerization stage is 0.1 to 10 per 1 g of the titanium compound.
0 g, preferably in the range of 1 to 100 g, and industrially, the range of 2 to 50 g is suitable.

In each prepolymerization step, different types of organosilicon compounds are used. As the organosilicon compound, a compound in which at least one of R and R ′ in the general formula [I] is a bulky hydrocarbon group, for example, a phenyl group, a cyclohexyl group or a norbornyl group, may be used.
It is preferable because an HMPE copolymer having a small amount of low molecular weight components can be obtained. The order of use of the organosilicon compounds used in each prepolymerization step is not particularly limited.

In each prepolymerization, it is preferable to polymerize propylene alone, but 5 mol% of α-olefin other than propylene such as ethylene, 1-butene, 1-pentene, 1-hexene and 4-methylpentene-1 is used. The following and propylene may be copolymerized. It is also possible to make hydrogen coexist at each prepolymerization stage.

In each prepolymerization, slurry polymerization is generally preferably applied. As a solvent, a saturated aliphatic hydrocarbon such as hexane, heptane, cyclohexane, benzene or toluene or an aromatic hydrocarbon alone or a mixed solvent thereof is used. Can be used. Each prepolymerization temperature is-
The temperature is preferably from 20 to 100 ° C, especially from 0 to 60 ° C, and each stage of the prepolymerization may be performed under different temperature conditions. The pre-polymerization time may be appropriately determined according to the pre-polymerization temperature and the amount of polymerization in the pre-polymerization, and the pressure in the pre-polymerization is not limited. In the case of slurry polymerization, the pressure is generally from atmospheric pressure to 5 kg / cm. it is about ² G. Each prepolymerization may be performed in any of batch, semi-batch, and continuous methods. After each prepolymerization, hexane, heptane,
It is preferable to wash a saturated aliphatic hydrocarbon or an aromatic hydrocarbon such as cyclohexane, benzene, or toluene alone or with a mixed solvent thereof.

After the above prepolymerization, main polymerization is carried out. The main polymerization is performed in the presence of the titanium-containing polypropylene, the organoaluminum compound, and the organosilicon compound obtained by the above preliminary polymerization.

As the organoaluminum compound used in the main polymerization, those used in the above-mentioned preliminary polymerization can be used, and most preferably, triethylaluminum is used. The amount of the organic aluminum compound used is 10 to 10 in terms of Al / Ti (molar ratio) with respect to the titanium atom in the titanium-containing polypropylene.
00, preferably 50-500.

Further, the organosilicon compound has the general formula
The compound represented by [I] is employed without any limitation. The amount of the organosilicon compound used in the main polymerization is Si / Ti (molar ratio) with respect to Ti atoms in titanium-containing polypropylene.
0.1 to 1000, preferably 0.5 to 500.

In the main polymerization, first, propylene is polymerized, and then, propylene and ethylene are copolymerized. The polymerization of propylene may be carried out by supplying a mixture of propylene and up to 5 mol% of an acceptable α-olefin. When the polymerization conditions of the propylene are exemplified, the polymerization temperature is preferably performed as low as possible in order to increase the bulk specific gravity of the HMPE copolymer. For example, the polymerization temperature is preferably 80 ° C. or less, and more preferably 20 to 70 ° C. It is suitable.
If necessary, hydrogen can also be allowed to coexist as a molecular weight regulator. Furthermore, the polymerization may be any method such as slurry polymerization using propylene and ethylene itself as a solvent, gas phase polymerization, and solution polymerization. Considering the simplicity of the process, the reaction rate, and the particle properties of the resulting block copolymer, slurry polymerization using propylene itself as a solvent is the most preferred embodiment. The polymerization method may be any of a batch system, a semi-batch system, and a continuous system, and the polymerization may be performed in two or more stages under different conditions.

Next, propylene-ethylene random copolymerization is performed. In the propylene-ethylene random copolymerization, the monomer unit based on propylene is 20 to 85 mol%, preferably 40 to 85 mol%, and the monomer unit based on ethylene is 15 to 80 mol%, preferably 15 to 60 mol%.
Propylene and ethylene may be mixed and used so as to be in the range of mol%. For this purpose, it is preferable to select the mixing ratio of propylene and ethylene so that the ethylene concentration in the gaseous state is 7 to 50 mol%, preferably 10 to 40 mol%. As other conditions, the same conditions as in the above-described polymerization of propylene can be adopted.

In the present polymerization, in order to control the stereoregularity of propylene, electron donors such as ethers, amines, amides, sulfur-containing compounds, nitriles, carboxylic acids, acid amides, acid anhydrides, acid esters, etc., in addition to the organosilicon compound. Can coexist.

After completion of the main polymerization, the monomer can be evaporated from the polymerization system to obtain a particulate polymer. The particulate polymer has a higher bulk specific gravity when subjected to a known washing or countercurrent washing with a hydrocarbon having 7 or less carbon atoms.

In the present invention, the HMPE copolymer obtained by the above method is melt-kneaded in the presence of an organic peroxide. By this melt-kneading, a propylene-based copolymer excellent in processability and having a arbitrarily adjusted molecular weight can be obtained.
In performing melt kneading, the HMPE copolymer and the organic peroxide are mixed, but the mixing method is not particularly limited. For example, a method of mechanically mixing using a blender such as a blender or a mixer, a method of dissolving an organic peroxide in an appropriate solvent, attaching the solution to the HMPE copolymer, and drying and mixing the solvent, etc. There is.

As the melt kneading temperature, a temperature not lower than the melting temperature of the HMPE copolymer and not lower than the decomposition temperature of the organic peroxide is employed. However, if the heating temperature is too high, the polymer is thermally degraded. Generally, the melting temperature is 170-300.
° C, particularly preferably in the range of 180 to 250 ° C.

As the organic peroxide used in the present invention, known organic peroxides are generally used. Typical organic peroxides include:
Peroxides such as methyl ethyl peroxide and methyl isobutyl peroxide; diacyl peroxides such as isobutyryl peroxide and acetyl peroxide; diisopropylbenzene hydroperoxide; other hydroperoxides; 2,5-dimethyl-2,5- Di- (t-butylperoxy) hexane,
1,3-bis- (t-butylperoxyisopropyl)
1,1-di-dialkyl peroxide such as benzene;
t-butylperoxy-cyclohexane and other peroxyketals; t-butylperoxyacetate, t
Alkyl peresters such as -butylperoxybenzoate; t-butylperoxyisopropyl carbonate, and other percarbonates. The amount of the organic peroxide used varies depending on the set value of the melt index of the obtained propylene-based copolymer and the like and is not determined unconditionally, but is 0.001 to 1.0 parts by weight based on 100 parts by weight of the HMPE copolymer. Parts, preferably 0.01 to
0.5 parts by weight is common.

Further, when the above organic peroxide is melted, a compound having two or more radically polymerizable groups in one molecule may be present. The presence of a compound having two or more radically polymerizable groups in one molecule allows the molecular chain to be crosslinked, thereby further improving the tackiness and heat resistance.

As the compound having two or more radical polymerizable groups in one molecule, known compounds can be employed without any limitation. Specifically, ethylene glycol diacrylate, diethylene glycol dimethacrylate, ethylene glycol bisglycidyl methacrylate, bisphenol A dimethacrylate, 2,2-bis (4-methacryloyloxyethoxyphenyl) propane, 2,2-bis (3,5- Acrylic acid and methacrylic acid ester compounds such as dibromo-4-methacryloyloxyethoxyphenyl) propane and trifluoromethyl methacrylate; diallyl phthalate, diallyl terephthalate, diallyl isophthalate, diallyl tartrate, diallyl epoxysuccinate, diallyl maleate, diallyl chlorendate Compounds such as diallyl, diallyl hexaphthalate, diallyl carbonate and allyl diglycol carbonate; aromatic vinyl compounds such as divinylbenzene It can be exemplified Le compounds.

A radical polymerizable group is contained in one molecule as described above.
The compounding amount of the compound having two or more compounds is not particularly limited, but is generally 0.1 to 100 parts by weight of the HMPE copolymer.
It is preferably in the range of 0.1 to 10 parts by weight, more preferably 0.1 to 1.0 part by weight.

The melt index of the propylene copolymer obtained by melt-kneading with the organic peroxide is 0.1 to 1
00g / 10 min, and the molecular weight distribution at this time was determined by the ratio of the weight average molecular weight to the number average molecular weight measured by GPC (bar M
w / bar Mn) is 4.0 or less, preferably 3.0 or less.

In the propylene copolymer obtained by melt-kneading, the formation of low molecular weight components was not substantially observed, and the components having a molecular weight of 10,000 or less measured by GPC were mixed with the HMPE copolymer before decomposition. It is 1.0% by weight or less as in the case of coalescence.
This is presumed to be the result of the decomposition by the organic peroxide selectively proceeding with respect to the high molecular weight component.

[0047]

The propylene-based copolymer obtained according to the present invention can be easily produced without sticking to the polymerization tank during the production in spite of a relatively large amount of ethylene component, and has a suitable molecular weight. Processability is good, and even though it is decomposed by organic peroxide, the low molecular weight component is extremely small, so there is no stickiness in the molded product, and it is a good product even when processed into films and sheets. Become.

The propylene-based copolymer obtained according to the present invention can be suitably used in various fields where conventional thermoplastic elastomers are used. For example, in the field of injection molding, there are bumpers, mudguards, lamp packings in automobile parts, and in home electric parts, various packings, ski shoes, grips and roller skates. On the other hand, in the extrusion molding field,
It can be suitably used as a coating material for various insulating sheets, cords and cables as a material for various automobile interiors, home appliances and electric wires, and as a waterproof sheet, a waterproof material and a joint material in the field of civil engineering and construction materials.

[0049]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The measuring method used in the following examples will be described.

1) The weight average molecular weight and the ratio of the molecular weight of 10,000 or less were measured by GPC (gel permeation chromatography). Waters GPC-15
O-dichlorobenzene as solvent at 135 ° C.
I went in. The column used was Tosoh TSK gel.
GMH6-HT, gel size 10-15μ. The calibration curve has a weight average molecular weight of 950,290 as a standard sample.
It was prepared using 0, 10,000, 50,000, 4.98 million, 2.7 million and 6.75 million polystyrene.

[0052] 2) the ethylene content of the ethylene content using JEOL GSX-270, ¹³
It measured using the C-NMR spectrometer.

3) Bulk specific gravity Performed according to JIS K 6721 (1977).

4) Particle size distribution Aperture 75, 125, 250, 355, 500, 71
About 5 g of a polymer was filled in a sieve having a size of 0.1180 μm, and the resulting mixture was classified on a sieve shaker for 10 minutes.

5) Flexural Modulus A test piece of 127 mm × 12 mm × 3.1 mm was prepared using an injection molding machine, and the test was performed according to ASTM D-790.

6) Izod impact value at −20 ° C. A test piece of 63 mm × 12 mm × 3.1 mm was prepared using an injection molding machine, and the test piece was measured at −20 ° C. according to ASTM D-256.

7) Evaluation of stickiness A sheet having a thickness of about 0.3 mm was formed by a Brabender extruder and cut into a size of 3.0 cm × 3.0 cm.
The sheets were piled up, and the peeling state after being left under a load of 1 kg for one week was determined by the following evaluation method.

A: There is no adhesion between the sheets, and all the sheets are excellent in peeling.

B: There are adhesions on two or three sheets, but they are relatively easily peeled off.

C: Seven or more sheets have adhesion, and peeling is relatively difficult.

D: Adhesion of each sheet is remarkable, and it cannot be peeled at all.

Example 1 [Preparation of Titanium Compound] The titanium component was prepared according to the method of Example 1 in JP-A-58-83006. That is, 0.95 g of anhydrous magnesium chloride (10 m
mol), 10 ml of decane and 4.7 ml (30 mmol) of 2-ethylhexyl alcohol at 125 ° C. for 2 minutes.
After heating and stirring for 0.5 hours, phthalic anhydride 0.5
5 g (3.75 mmol) was added, and the mixture was further stirred and mixed at 125 ° C. for 1 hour to obtain a homogeneous solution. After cooling to room temperature, 40 ml of titanium tetrachloride kept at 120 ° C.
(0.36 mol) over 1 hour. After completion of the charging, the temperature of the mixed solution was raised to 1 over 2 hours.
The temperature was raised to 10 ° C., and when the temperature reached 110 ° C., 0.54 ml (2.5 mmol) of diisophthalate was added, and the mixture was kept under stirring at the same temperature for 2 hours. After completion of the reaction for 2 hours, a solid portion was collected by hot filtration, and the solid portion was collected for 200 m.
after resuspension in TiCl ₄ at 110 ° C. for 2 hours.
The heating reaction was performed for a time. After completion of the reaction, a solid portion was collected again by hot filtration, and sufficiently washed with decane and hexane until no free titanium compound was detected in the washing solution. The solid Ti catalyst component prepared by the above production method was stored as a heptane slurry. The composition of the solid Ti catalyst component was 2.1% by weight of titanium, 57% by weight of chlorine, 18.0% by weight of magnesium, and 21.9% by weight of diisobutyl phthalate.

[Preliminary polymerization] 200 ml of purified heptane, 50 mmol of triethylaluminum and 10 parts of diphenyldimethoxysilane were placed in a 1-liter autoclave substituted with N _2.
mmol, 50 mmol of ethyl iodide and 5 mmol of a solid Ti catalyst component in terms of Ti atoms, and then propylene was introduced into the reactor continuously for 1 hour so as to be 5 g per 1 g of the solid Ti catalyst component. Was given. The temperature during this period was kept at 15 ° C. One hour later, the introduction of propylene was stopped, and the inside of the reactor was sufficiently replaced with N ₂ . The solid portion of the resulting slurry was washed six times with purified heptane.

Further, 1 l of this solid component was subjected to N ₂ substitution.
-200 m of purified heptane charged in an autoclave
1, 50 mmol of triethylaluminum, 10 mmol of 6-triethoxysilyl 2-norbornene and 10 mmol of ethyl iodide, and then propylene was further added to solid T.
The catalyst was introduced into the reactor continuously for 1 hour so that the amount became 5 g per 1 g of the catalyst component, and the second prepolymerization was performed. The temperature during this period was kept at 15 ° C. The solid part of the obtained slurry was washed six times with purified heptane to obtain a titanium-containing polypropylene.

[Polymerization] 300 l capacity with N ₂ substitution
200 liters of liquid propylene, 274 mmol of triethylaluminum and 274 mmol of diphenyldimethoxysilane were charged into the autoclave, and the internal temperature of the autoclave was raised to 60 ° C., and the titanium-containing polypropylene obtained by the prepolymerization was converted to titanium atom. As 1.1
mmol was charged. Polymerization of the polypropylene was carried out at 60 ° C. for 90 minutes. Subsequently, the internal temperature of the autoclave was lowered to 55 ° C., and the supply of ethylene was started. The copolymerization of propylene and ethylene was carried out for 90 minutes while confirming by gas chromatography that the ethylene gas concentration in the gas phase was 25 mol%. After the completion of the polymerization, unreacted propylene was flushed to obtain white granular polymer particles. The yield was 38 kg, and the polymerization activity at this time was 15,200 g-polymer / g-Ti compound. Also, from a separate experiment, the polymerization activity of polypropylene at 60 ° C. for 90 minutes was 3,500 g-polymer / g-Ti compound, indicating that the proportion of the polypropylene component in the polymer was 23 wt%. The results are shown in Table 1.

The obtained white granular polymer particles were added with 1,
3-Bis- (t-butylperoxyisopropyl) -benzene was mixed as shown in Table 2, and an antioxidant, a heat stabilizer and a chlorine scavenger were further added and mixed with a Henschel mixer. Next, pellets were obtained by extruding with a 40 mm single screw extruder such that the resin temperature at the exit of the die was 220 ° C. The results are shown in Table 2.

Examples 2 and 3 In the polymerization of Example 1, the ethylene gas concentration was changed to 15 mol.
The same operation as in Example 1 was performed except that the amounts were 1% and 30 mol%. The results are shown in Tables 1 and 2.

Example 4 In the polymerization of Example 1, the polymerization of polypropylene
The same operation as in Example 1 was performed except that the temperature was set to 0 ° C. for 30 minutes. The results are shown in Tables 1 and 2.

Example 5 The same operation as in Example 1 was carried out except that in the polymerization of propylene and ethylene, hydrogen gas was introduced so as to have a gas concentration of 0.02 mol% in the copolymerization of propylene and ethylene. Was done.
The results are shown in Tables 1 and 2.

Example 6 The procedure of Example 1 was repeated except that phenyltriethoxysilane was used instead of 6-triethoxysilyl-2-norbornene as the second organosilicon compound in the prepolymerization of Example 1. The same operation was performed. The results are shown in Tables 1 and 2.

Examples 7 and 8 The amount of 1,3-bis- (t-butylperoxyisopropyl) -benzene added to the white granular polymer obtained in Example 1 was changed as shown in Table 2. Except for this, the same operation as in Example 1 was performed. The results are shown in Table 2.

Example 9 In the polymerization of Example 1, the polymerization of polypropylene was
The same operation as in Example 1 was performed except that the temperature was set to 120 ° C. for 120 minutes. The results are shown in Tables 1 and 2.

Comparative Example 1 Example 1 was repeated except that the prepolymerization of Example 1 was not carried out.
The same operation as described above was performed. The results are shown in Tables 1 and 2.

Comparative Example 2 In the copolymerization of propylene and ethylene of Example 1, the same operation as in Example 1 was carried out except that hydrogen gas was introduced so as to have a gas concentration of 1.8 mol%. The results are shown in Table 1. Cohesion of the particles was remarkable and pellets could not be formed.

Comparative Example 3 In the polymerization of Example 1, the polymerization of polypropylene was carried out at 70 ° C.
For 120 minutes, and copolymerization of propylene and ethylene
The same operation as in Example 1 was performed except that the temperature was 5 ° C. for 30 minutes. The results are shown in Tables 1 and 2.

Example 10 To the copolymer particles obtained in Example 1 were added 0.5% by weight of ethylene glycol dimethacrylate
Same as Example 1 except that 3-bis- (t-butylperoxyisopropyl) benzene, an antioxidant, a heat stabilizer, and a chlorine scavenger were added, mixed with a Henschel mixer, and pelletized with a 40 mm medium extruder. Was performed. The results are shown in Table 2.

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[Table 1]

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[Table 2]

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Claims (2)

(57) [Claims] 1. A block copolymer containing a polypropylene component and a propylene-ethylene random copolymer component, wherein the polypropylene component is 3-50% by weight and the propylene-ethylene random copolymer component is 93-50% by weight.
Wherein the propylene-ethylene random copolymer component comprises a random copolymer containing 15-80 mol% of a monomer unit based on ethylene and 85-20 mol% of a monomer unit based on propylene. The ratio of components having a molecular weight of 10,000 or less is 1.0% by weight or less, and the propylene-based block copolymer having a weight-average molecular weight of 1,000,000 to 7,000,000 and an organic peroxide are melt-kneaded. A method for producing a propylene-based copolymer characterized by a melt index of 0.1 to 100 g / 10 min. 2. A method of melting and kneading the propylene-based block copolymer according to claim 1 and an organic peroxide in the presence of a compound having two or more radically polymerizable groups in one molecule. Melt index 0.1-100g / 10
For producing a propylene-based copolymer of the present invention.