JPH1171428A - Low crystalline polypropylene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low crystalline polypropylene which shows excellent flexibility, transparency, shock resistance and thermal stability and gives good formability. SOLUTION: A homopolymer of propylene or a copolymer of propylene and not more than 5 mol.% of α-olefin other than propylene shows a melt flow rate of 1-20 g/10 min and molecular weight distribution (Mw /Mn ) represented by a ratio of weight average molecular weight to number average molecular weight of 4-15. When the polymer is fractionated by temperature increasing elution fractionation to give an elution curve represented by a vertical axis of elution temperatures and a transverse axis of accumulated weight ratio of eluted components, the amount of eluted component (component A) at temperatures less than 20 deg.C is 5-35 weight %, the amount of eluted component (component B) at temperatures from 20 deg.C to less than 100 deg.C is 10-40 weight %, the amount of eluted component (component C) at temperatures not less than 100 deg.C is 40-80 weight % and the sum of the components A, B and C is 100 weight %, satisfying that a weight ratio of the component B to the component A (B/A) is not less than 0.6 and a peak top temperature of the component C is not less than 120 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low crystallinity polypropylene having excellent flexibility, transparency, impact resistance and heat resistance and good moldability.

[0002]

2. Description of the Related Art Polypropylene is widely used for industrial parts, sheets, films and the like because of its excellent moldability, rigidity and heat resistance. However, conventionally used so-called isotactic polypropylene, which has high crystallinity, is excellent in rigidity and heat resistance, but is inferior in flexibility, impact resistance and transparency. Many means have been proposed to remedy these drawbacks. For example, in order to improve impact resistance, a method of randomly copolymerizing propylene and another α-olefin, or a method of copolymerizing propylene and ethylene followed by propylene and ethylene to form a block copolymer are known. Have been. However,
When a random copolymer is used, impact resistance and transparency are improved, but there is a problem that the heat resistance is impaired because the melting point is significantly reduced. Further, when a block copolymer is used, there is a problem that the impact resistance and the heat resistance are excellent, but the transparency is significantly reduced.

[0003] On the other hand, a method of reducing stereoregularity in order to impart flexibility to polypropylene is also known. For example, Japanese Unexamined Patent Publication (Kokai) No. 59-122506 proposes a polypropylene having a wide molecular weight distribution, a relatively high melting point, and flexibility, and low stereoregularity. However, in this method, there is still room for improvement in the balance between flexibility and heat resistance, and it has been desired that even more flexible polypropylene has high heat resistance. Also, JP-A-6-2
JP-A-63934 discloses a polypropylene excellent in rubber elasticity by containing an atactic component having a specific viscosity. However, the melt flow rate of the obtained polypropylene is relatively low, and the polypropylene is still improved in moldability. There was room.

As a method for solving this problem, Japanese Patent Application Laid-Open No.
JP-A-157606 proposes a method for adjusting the melt flow rate by melt-kneading a low stereoregularity polypropylene having a weight average molecular weight of 1,000,000 or more in the presence of an organic peroxide. Has a small molecular weight distribution, so that the melt tension at the time of forming into a sheet or a film is lowered, and there is a problem in workability.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a low-crystalline polypropylene having good flexibility, transparency, impact resistance, heat resistance and moldability, and a good balance of these properties. Is to provide.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, a low-crystalline polypropylene having a specific molecular weight distribution and crystallinity distribution satisfies all of the above objects. They found something and completed the present invention.

That is, the present invention relates to a propylene homopolymer or a copolymer of propylene and an α-olefin having a content of α-olefin units other than propylene of 5 mol% or less, wherein (1) melt flow rate Is 1 to 20 g / 1
0 minutes, (2) weight average molecular weight (M _w) and number-average molecular weight molecular weight distribution represented by the ratio of _{(M n) (M w /} M n), 4
-15, (3) Elution components at less than 20 ° C. in an elution curve represented by the elution temperature (° C.) on the horizontal axis and the integrated weight ratio of the elution components on the vertical axis, which were fractionated by the elevated temperature elution fractionation method. The amount of the (A component) is 5 to 35% by weight, and the amount of the eluting component (B component) at 20 ° C. or more and less than 100 ° C. is 10 to 40% by weight,
40-80% by weight of the elution component (C component) above
The total of the components, the B component and the C component is 100% by weight, the weight ratio of the B component and the A component (B / A) is 0.6 or more, and the peak top temperature of the C component is 120 ° C. or more;
Is a low crystalline polypropylene.

Further, the present invention provides a film or sheet obtained by using the above-mentioned low-crystalline polypropylene, which has good flexibility, transparency, impact resistance and heat resistance and has a good balance of these properties. Also provide.

The low-crystalline polypropylene of the present invention comprises a propylene homopolymer or a propylene and α-olefin having a content of α-olefin units other than propylene of 5 mol% or less.
-A copolymer with an olefin (hereinafter also referred to as a propylene-α-olefin copolymer).

In the present invention, α-olefins other than propylene include, for example, ethylene, 1-butene,
-Pentene, 1-hexene, 1-heptene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene and the like. When the content of the α-olefin unit in the propylene-α-olefin copolymer exceeds 5 mol%, the heat resistance is impaired due to a decrease in the melting point, which is not preferable.

In the low crystallinity polypropylene of the present invention, if the melt flow rate is less than 1, molding processability becomes difficult, and if it exceeds 20, the melt tension decreases,
In particular, molding processability in extrusion molding is unpreferably reduced.

The melt flow rate of the low crystalline polypropylene of the present invention is approximately 200,000 when converted into a weight average molecular weight by gel permeation chromatography.
It is in the range of 500,000.

The low-crystalline polypropylene of the present invention has a molecular weight distribution (M _w ) represented by the ratio of the weight average molecular weight (M _w ) and the number average molecular weight (M _n ) measured by gel permeation chromatography (GPC). / M _n ) is 4
-15, preferably 5-15 is necessary for obtaining excellent moldability. When the molecular weight distribution is less than 4, the moldability decreases, and when the molecular weight distribution exceeds 15, the anisotropy of the orientation of the resin after molding increases, and not only does the warpage of the molded product, the balance of the shrinkage ratio etc. decrease, It is not preferable because impact resistance is also reduced.

The low-crystalline polypropylene of the present invention is characterized in that the weight-average molecular weight (M _w ) measured by gel permeation chromatography (GPC) is such that the amount of components of 10,000 or less is 3% by weight or less. This is preferable for suppressing stickiness of the ink.

In the present invention, the elevated temperature elution fractionation method includes, for example, Journal of Applied Pol
ymer Science; Applied Poly
mer Symposium 45, 1-24 (199
0) is described in detail. First, a high-temperature polymer solution is introduced into a packed column using diatomaceous earth as a filler, and the temperature of the column is gradually decreased to crystallize the filler surface in order from the component with the higher melting point, and then the column temperature is gradually increased. In this method, the components are eluted in order from the component having the lowest melting point to separate the eluted polymer components. In the present invention, as shown in the Examples, SSC-7300 manufactured by Senshu Kagaku Co., Ltd. was used as a measuring device, and a solvent:
O-dichlorobenzene, flow rate: 2.5 ml / min, heating rate: 4 ° C./Hr, column: φ30 mm × 300 mm
Shows the values measured under the conditions.

20 ° C. of the low crystalline polypropylene of the present invention
The eluted component (A component) with less than the above is a component necessary especially for developing flexibility. That is, if the amount of the component A is less than 5% by weight, flexibility is impaired, and if it exceeds 35% by weight, sufficient heat resistance cannot be obtained, which is not preferable.
In order to exhibit more excellent flexibility and heat resistance, the amount of the component A is particularly preferably in the range of 10 to 30% by weight.

20 ° C. of the low crystalline polypropylene of the present invention
The eluted component (component B) at a temperature of less than 100 ° C. is a component necessary to express a good balance between transparency, flexibility and heat resistance. That is, the amount of the component B is 10% by weight.
If the amount is less than 40%, good transparency and flexibility cannot be achieved when a molded article is obtained. If the amount exceeds 40% by weight, heat resistance is insufficient. In order to develop a better balance between transparency, flexibility and heat resistance, the amount of the B component is particularly preferably from 10 to
Preferably it is in the range of 30% by weight.

The elution component (component C) of the propylene resin of the present invention at 100 ° C. or higher is a component necessary for obtaining the excellent heat resistance characteristic of the present invention. That is, when the amount of the C component is less than 40% by weight, or when the peak top temperature of the C component is less than 120 ° C., the heat resistance of a molded article is impaired, and the amount of the C component exceeds 80% by weight. In such a case, it is not preferable because flexibility is impaired. In consideration of flexibility and heat resistance, the amount of the component C is preferably more than 50% by weight and 70% by weight or less. Further, in order to obtain more excellent heat resistance, the C component is preferably a highly crystalline polypropylene component having 60% by weight or more of an eluted component at 115 ° C. or higher.

The weight ratio (B / A) of the component B to the component A of the low crystalline polypropylene of the present invention is 0.6 or more;
Preferably it is 0.7 or more. When the weight ratio (B / A) of the component B and the component A (B / A) is less than 0.6, the balance of transparency, flexibility and heat resistance, which are the characteristics of the present invention, is not sufficiently exhibited, and the object of the present invention is achieved. Not done.

The molecular weight distribution (M _w / M _n ) of each of the component A, component B and component C of the low crystalline polypropylene of the present invention is preferably 4 to 15 in order to obtain good moldability.

The low crystalline polypropylene of the present invention has a melting point of 150 as measured by differential scanning calorimetry (DSC).
It is preferable that the heat of fusion be 100 ° C. or higher and 100 J / g or lower. When the melting point is lower than 150 ° C., sufficient heat resistance cannot be obtained, and when the heat of fusion exceeds 100 J / g, flexibility is impaired, which is not preferable.

The low crystallinity polypropylene of the present invention can be obtained from JI
The deflection temperature under load determined by a measurement method based on SK7207 is preferably 50 ° C. or more.

The method for producing the low-crystalline polypropylene of the present invention is not particularly limited as long as it satisfies the requirements of the present invention. For example, it can be obtained by the following method.

The following catalyst components [A], [B], [C] [A] Titanium compound [B] General formula R ¹ _n AlX _3-n (where R ¹ is a saturated hydrocarbon group having 1 to 10 carbon atoms) , X is a halogen atom, and n is an integer of 0 to 3) [C] Formula (I) R ² _{n /} 2Al (OR ³ ) _{3-n / 2} (I) (where, R ² and R ³ are the same or different and are a saturated hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 1 to 4) or a compound of the general formula (II)

[0025]

Embedded image

(Where R ⁴ is an alkyl group, an aryl group or a halogen atom, R ⁵ , R ⁶ and R ⁷ are a hydrogen atom, an alkyl group or an aryl group, and n is 0 <n <
3. In the presence of the organoalkoxyaluminum compound represented by the formula (1), firstly, homopolymerization of propylene or copolymerization of propylene with another α-olefin is carried out in the absence or presence of hydrogen in the first step. As a step, in the presence of the components [A], [B], and [C], an electron donor compound [D] is further added to carry out a second step of polymerization. This is a method for increasing the hydrogen concentration.

As the titanium compound [A], a titanium compound known to be used for the polymerization of olefin is used without any limitation. These titanium compounds are roughly classified into a supported titanium compound and a titanium trichloride compound. As a method for producing the supported titanium compound, a known method is employed without any limitation. For example, Japanese Patent Application Laid-Open Nos. 56-155206 and 56
-136806, 57-34103, 58-870
6, 58-83006, 58-138708, 5
8-183709, 59-206408, 59-2
19311, 60-81208, 60-8120
9, 60-186508, 60-192708, 61-211309, 61-271304, 62-
15209, 62-11706, 62-7270
2, the methods shown in 62-104810 and the like are adopted.

Specifically, for example, a method in which titanium tetrachloride is co-ground with a magnesium compound such as magnesium chloride, a method in which a titanium halide is mixed with a magnesium compound in the presence of an electron donor such as an alcohol, ether, ester, ketone or aldehyde. And a method of contacting a titanium halide, a magnesium compound and an electron donor in a solvent. Examples of the titanium trichloride compound include known α, β, γ, and δ-titanium trichloride. Methods for preparing these titanium trichloride compounds are described, for example, in JP-A-47-34478,
126590, 50-114394, 50-938
88, 50-123091, 50-74594, 50-104191, 50-98489, 51-1
36625, 52-30888, 52-35283
Etc. are adopted.

Next, as the organoaluminum compound [B], a compound known to be used for polymerization of olefins is employed without any limitation. For example, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, tri-i-
Butyl aluminum, tri-n-hexyl aluminum, tri-n-octyl aluminum, trialkyl aluminums such as tri-n-decyl aluminum or diethyl aluminum monochloride, diethyl aluminum monohalides such as diethyl aluminum bromide or methyl aluminum sesquichloride, Examples thereof include alkyl aluminum halides such as ethyl aluminum sesquichloride and ethyl aluminum dichloride.

The organic alkoxyaluminum compound [C] is a reaction product of an alkylaluminum or an alkylaluminum halide with an alcohol, and the organic alkoxyaluminum compound represented by the general formulas (I) and (II) is not limited. Adopted without.

Examples of the organic alkoxyaluminum compound represented by the general formula (I) include dimethylaluminum methoxide, dimethylaluminum ethoxide, dimethylaluminum isopropoxide, diethylaluminum methoxide, diethylaluminum ethoxide,
Examples thereof include diethylaluminum-n-butoxide, methylaluminum sesquimethoxide, methylaluminum sesquiethoxide, ethylaluminum sesquiethoxide, ethylaluminum diethoxide, diisobutylaluminum ethoxide, and ethylaluminum chloride monoethoxide.

As the organic alkoxyaluminum compound represented by the general formula (II), for example, dimethylaluminum phenoxide, dimethylaluminum (2-
Methylphenoxide), dimethylaluminum (2,4
-Dimethylphenoxide), dimethylaluminum (2,6-dimethylphenoxide), dimethylaluminum (2,4,6-trimethylphenoxide), dimethylaluminum (2,6-diisopropylphenoxide), dimethylaluminum (2,6-di-t) -Butylphenoxide), dimethylaluminum (2,6-diphenylphenoxide), diethylaluminum phenoxide, diethylaluminum (2-methylphenoxide), diethylaluminum (2,4-dimethylphenoxide), diethylaluminum (2,6-dimethylphenoxide) , Diethylaluminum (2,4,6-trimethylphenoxide), diethylaluminum (2,4,6-trimethylphenoxide)
6-diisopropylphenoxide), diethyl aluminum (2-isobutyl phenoxide), diethyl aluminum (2-t-butyl phenoxide), diethyl aluminum (2,6-di-t-butyl phenoxide), diethyl aluminum (2,6-di- t-butyl-4-methylphenoxide), diethylaluminum (2,6-
Diphenylphenoxide) and the like.

Further, as the electron donor compound [D], a compound known to be used for improving the stereoregularity of an olefin is employed without any limitation. For example, methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, isopropyl alcohol,
Alcohols such as isoamyl alcohol, phenol,
Phenols such as cresol, cumylphenol, xylenol and naphthol; ketones such as acetone, methyl ethyl ketone, acetophenone and benzophenone; aldehydes such as acetaldehyde, propionaldehyde and benzaldehyde; methyl formate, methyl acetate, ethyl acetate, butyl acetate and acetic acid Organic acids such as vinyl, methyl propionate, ethyl propionate, ethyl valerate, ethyl stearate, ethyl acrylate, methyl methacrylate, ethyl benzoate, methyl toluate, methyl anisate, ethyl phthalate, methyl carbonate, butyrolactone Esters, methyl ether, ethyl ether, isopropyl ether, isoamyl ether, tetrahydrofuran, anisole, ethers such as diethylene glycol dimethyl ether, vinegar Amide, amide benzoate, acid amides such as maleic acid amide, methylamine, ethylamine, piperidine, pyridine, amines such as aniline,
Acetonitrile, nitriles such as benzonitrile, dimethyldimethoxysilane, diethyldimethoxysilane, ethyl silicate, divinyldimethoxysilane, diallyldimethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, methyltriethoxysilane,
Ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, pentyltriethoxysilane, isopropyltriethoxysilane, cyclohexylmethyldimethoxysilane, di-t-butyldimethoxysilane, t-butylethyldimethoxysilane, di-t-amyldimethoxysilane , Dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylethyldimethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylethyldimethoxysilane, cyclohexyl Examples of organosilicon compounds such as isobutyldimethoxysilane It is possible. Further, a plurality of these electron donor compounds can be used at the same time.

The titanium compound [A] used in the present invention,
The combination of the organoaluminum compound [B], the organoalkoxyaluminum compound [C] and the electron donor [D] is as follows: (1) supported titanium compound-trialkylaluminum-organoalkoxyaluminum compound-electron donor (2) trichloride Titanium compound-diethylaluminum monohalide-organoalkoxyaluminum compound-electron donor (3) titanium trichloride compound-trialkylaluminum-organoalkoxyaluminum compound-electron donor; and (4) supported titanium compound-titanium trichloride compound The combination of -trialkylaluminum-organoalkoxyaluminum compound-electron donor is particularly preferable because it satisfies the constitution of the low crystalline polypropylene of the present invention in combination with other production conditions.

In the present invention, prior to the main polymerization in the presence of each of the above-mentioned components, the pre-polymerization of propylene in the presence of the same components is carried out so that the resulting polymer powder has high fluidity. It is preferable because it can be performed.

In the prepolymerization, in addition to the system using [A] and [B], and if necessary, [D],
It is also possible to add an iodine compound [E] represented by the following general formula (I) for the purpose of reducing the amount of low molecular weight components produced in the low stereoregularity polypropylene obtained by the main polymerization.

[E] Iodine compound RI (I) (where R is an iodine atom or an alkyl group having 1 to 7 carbon atoms or a phenyl group) The amount of each of these components used in the prepolymerization is as follows: Type of catalyst,
Since the amount varies depending on the polymerization conditions, the optimum amount to be used may be determined in advance according to each of these conditions. An example of a generally preferred range is as follows.

That is, the ratio of the organoaluminum compound [B] used in the prepolymerization is 0.1 to 100, preferably 0.1 to 20 in terms of Al / Ti (molar ratio) with respect to the titanium compound [A]. The organoalkoxyaluminum compound [C] used if necessary is 0.01 to [C] / Ti (molar ratio) with respect to the titanium compound [A].
100, preferably in the range of 0.01 to 10, and the proportion of the electron donor compound [D] used is the titanium compound [A].
0.01 to 100 in [D] / Ti (molar ratio),
Preferably, the range of 0.01 to 10 is suitable. Further, an iodine compound [E] optionally used
Is in the range of 0.1 to 100, preferably 0.5 to 50 as I / Ti (molar ratio) with respect to the titanium compound [A].

Specific examples of the iodine compound which can be suitably used in the prepolymerization of the present invention are as follows. For example, iodine, methyl iodide, ethyl iodide, propyl iodide,
Butyl iodide, iodobenzene, p-iodine toluene and the like. Particularly, methyl iodide and ethyl iodide are preferred.

The amount of prepolymerization for polymerizing the α-olefin in the presence of the catalyst component varies depending on the prepolymerization conditions.
Generally, a range of 0.1 to 500 g / g · Ti compound, preferably 1 to 100 g / g · Ti compound, is sufficient. The α-olefin used in the prepolymerization may be propylene alone, and other α-olefins, for example, ethylene, 1-butene, 1-pentene, 1-hexene, and so on as long as the physical properties of the polymerization powder are not adversely affected. 4-methylpentene-1 or the like may be mixed with propylene. Further, the prepolymerization may be performed in multiple stages, and a different α-olefin monomer may be prepolymerized in each stage. It is also possible to make hydrogen coexist at each prepolymerization stage.

In the prepolymerization, slurry polymerization is usually preferably applied. As a solvent, a saturated aliphatic hydrocarbon or an aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene or toluene is used alone, or a mixed solvent thereof. Can be used.

The prepolymerization temperature is preferably in the range of -20 to 100 ° C, particularly preferably 0 to 60 ° C. 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, but in the case of slurry polymerization, generally, the pressure is from atmospheric pressure to 5 kg / c.
It is about m ² G. The prepolymerization may be performed in any of batch, semi-batch, and continuous methods.

The main polymerization is carried out after the preliminary polymerization. In the main polymerization of the low crystalline polypropylene of the present invention, it is preferable to perform the main polymerization by multistage polymerization of two or more stages under different conditions in order to satisfy a specific molecular weight distribution and crystallinity distribution.

The amount of the organoaluminum compound [B] used in the first stage of the main polymerization is Al / Ti (molar ratio) based on titanium atoms in the titanium compound-containing prepolymer.
In the range of 1 to 1000, preferably 2 to 500. The amount of the organic alkoxyaluminum compound [C] to be used is 0.01 to 10 mol, preferably 0.1 to 10 mol, per 1 mol of the organic aluminum compound [B]. Further, the electron donor [D] used in the second stage of the main polymerization is used in an amount of 0.001 to 10 mol, preferably 0.01 to 10 mol, per 1 mol of the organoaluminum compound [B] used in the first stage. １1 mol.

In the first stage polymerization, the titanium compound-containing prepolymer obtained by the prepolymerization and the above-mentioned [B],
The order of addition of [C] to the polymerization system is not particularly limited, and a mixture in which the respective components are mixed in advance may be used.

The polymerization of propylene in the first stage is carried out in the absence or presence of hydrogen by supplying propylene alone or a mixture of propylene and another α-olefin within a range satisfying the requirements of the present invention. Then, the second stage polymerization may be carried out by adding the electron donor compound [D] and hydrogen.

In the present invention, it is important to carry out the polymerization in the first stage and the second stage under different hydrogen concentrations.
In the second stage polymerization, by increasing the hydrogen concentration more than in the first stage, a component having a lower molecular weight than the polymer to be polymerized in the first stage is polymerized. Further, the electron donor added in the second stage increases the crystallinity of the polymer polymerized in the second stage more than the polymer in the first stage, and from the above effects, the specific molecular weight distribution and the crystallinity distribution of the present invention are improved. A satisfactory low stereoregularity polypropylene is obtained.

In the present invention, when the first-stage polymerization is carried out in the presence of hydrogen, the first-stage polymerization is carried out in order to reduce the fluidity and low-molecular-weight components of the resulting low stereoregularity polypropylene polymer. It is preferable to set the hydrogen concentration so that the weight average molecular weight of the polymer is 700,000 or more.

To illustrate typical conditions for the propylene polymerization in the first and second stages, the polymerization temperature is 80 ° C. or less,
Further, it is preferable to adopt from a range of 20 to 70 ° C. Further, the polymerization may be any method such as slurry polymerization using propylene itself as a solvent, gas phase polymerization, solution polymerization and the like. Considering the simplicity of the process, the reaction rate, and the particle properties of the produced polymer powder, slurry polymerization using propylene itself as a solvent is a preferred embodiment. The polymerization system may be any of a batch system, a semi-batch system, and a continuous system.

After completion of the main polymerization, the monomer is evaporated from the polymerization system to obtain the low crystalline polypropylene of the present invention. This low-crystalline polypropylene can be subjected to known washing or countercurrent washing with a hydrocarbon having 7 or less carbon atoms.

The method for producing low-crystallinity propylene of the present invention is not limited to the above-mentioned polymerization method, but may be obtained by blending a high-crystallinity polypropylene and a low-crystallinity polypropylene separately obtained by polymerization as long as the requirements of the present invention are satisfied. However, in order to obtain good transparency, it is a preferable embodiment to produce by a polymerization method.

The low-crystalline polypropylene of the present invention is prepared by adding commercially available additives such as an antioxidant, a heat stabilizer, a chlorine scavenger, a light stabilizer, a lubricant, an antiblocking agent, a nucleating agent and an antistatic agent. After mixing, pellets may be used with an extruder. Further, an organic peroxide may be added in addition to the above additives to adjust the molecular weight within a range satisfying the requirements of the present invention.

The low-crystalline polypropylene of the present invention can be formed into a predetermined shape by a general molding method such as extrusion molding, injection molding, blow molding, press molding and the like.

In particular, in the form of a film or sheet, it is suitable as a soft material that can replace soft polyvinyl chloride resin, which has become a social problem due to environmental pollution, and polyvinyl alcohol resin whose use is limited due to hygroscopicity. Can be used. As a film forming method, for example, a general forming method such as a T-die method and an inflation method can be adopted without any limitation, and the film may be stretched uniaxially or more. As a method of forming a sheet, an extrusion molding method and a calendering method are general, and in the extrusion molding method,
A molding method such as a three-roll type, a touch roll type, and an air knife type can be used without any limitation. The film or sheet formed by the above method may be subjected to a generally known surface treatment method such as corona discharge treatment in order to impart printability.

[0055]

Industrial Applicability The low-crystalline polypropylene of the present invention has a moderate flexibility, is excellent in transparency, impact resistance and heat resistance, and has good molding processability. Alternatively, it can be suitably used in various fields where a soft vinyl chloride resin or the like is used. For example, in the field of injection molding, bumpers, mudguards, and lamp packings for automobile parts, and in the field of home appliances, various packings, ski shoes, grips, and roller skates. On the other hand, in the extrusion molding field, it is suitably used as various automotive interior materials, various insulating sheets as home appliance and electric wire materials, covering materials for cords and waterproof sheets, waterproof materials, joint materials, stretch films for packaging, etc. in the field of civil engineering and construction materials. be able to.

In particular, among the above embodiments, the film or sheet made of the low-crystalline polypropylene of the present invention has flexibility and excellent transparency, impact resistance and heat resistance.

[0057]

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 measurement method used in the following examples will be described.

(1) Elevated Temperature Elution Separation Method SSC-7300 manufactured by Senshu Scientific Co., Ltd. was used under the following measurement conditions.

Solvent; O-dichlorobenzene flow rate; 2.5 ml / min heating rate; 4 ° C./Hr sample concentration; 0.7 wt% sample injection amount; 100 ml detector; infrared detector, wavelength 3.41 μm column; φ30mm × 300mm filler; Chromosorb P 30-6
0 mesh Column cooling rate; 2.0 ° C./Hr (2) Melt flow rate (hereinafter abbreviated as MI) Based on ASTM D-1238.

(3) Molecular weight distribution P. It was measured by the C (gel permeation chromatography) method. Sensyu Science SSC-7
Using o-dichlorobenzene as solvent, 135
C. was performed. The column used was Shodex UT80.
7, 806M. The calibration curve is a standard sample having a weight average molecular weight of 950, 2900, 10,000, 50,000 and 49.8.
Were prepared using 10,000, 2.7, and 4.9 million polystyrene.

(4) Flexural modulus According to ASTM D-790.

(5) Izod impact value Based on JIS K7110.

(6) Transparency (Haze value) A test piece having a thickness of 1 mm was prepared by injection molding and subjected to JIS.
K6714.

(7) Deflection temperature under load According to JIS K7207, a load of 4.6 kg / cm ²
Was measured.

(8) Melt tension Using an MT measuring device manufactured by Toyo Seiki Seisaku-sho, an orifice having a diameter of 2.095 mm was attached to a cylinder maintained at 230 ° C.
After the pellet piston was inserted and held for 6 minutes, the melt tension at an extrusion speed of 10 mm / min and a winding speed of 25 m / min was measured.

(9) Tensile modulus According to JIS K7127.

(10) DuPont Impact Strength In a chamber maintained at 0 ° C., a weight of 1 kg is dropped on a hitting core having a radius of イ ン チ inch, a sheet is punched out, and 50%
The energy at the time of destruction was calculated.

(11) Hanging Time The sheet sample was sandwiched between clamp frames (400 mm × 400 mm) and heated from above and below by a far infrared heater set at 300 ° C. 20m from the center of the sheet from the start of heating
The time required for the sample to sag was measured and used as an index of heat resistance.

Example 1 (Preliminary polymerization) A 1-liter glass autoclave reactor equipped with a stirrer was sufficiently replaced with nitrogen gas, and then 400 ml of heptane was charged. Reactor temperature 2
After keeping at 0 ° C., 0.18 mmol of butyl acetate, 22.7 mmol of ethyl iodide, 18.5 mmol of diethylaluminum chloride, and 22.7 mmol of titanium trichloride (manufactured by Marubeni Solvay Chemical Co., Ltd.) were added, and then propylene was added to 1 g of titanium trichloride. The reactor was continuously introduced into the reactor at a rate of 3 g per 30 minutes. The temperature during this period was kept at 20 ° C. After stopping the supply of propylene, the inside of the reactor was sufficiently replaced with nitrogen gas, and the obtained titanium-containing polypropylene was washed four times with purified n-hexane. As a result of the analysis,
2.9 g of propylene was polymerized per 1 g of titanium trichloride.

(Main Polymerization) In a 2 liter autoclave with N ₂ substitution, 1 liter of liquid propylene, 0.70 mmol of diethyl aluminum chloride, ethyl aluminum sesquiethoxide (Et _1.5 Al (OEt))
_1.5 ) 0.70 mmol was added, and the internal temperature of the autoclave was raised to 70 ° C. The titanium compound-containing polypropylene obtained by the pre-polymerization was 0.087 mm as titanium trichloride.
In addition, polymerization of propylene was performed at 70 ° C. for 2 hours (first stage). Next, 0.014 mmol of butyl acetate was added, hydrogen was inserted so that the concentration in the gas phase might be 2 mol%, and polymerization was performed for 1 hour (second stage).

The unreacted monomer was purged to obtain a polymer. The obtained polymer was dried under reduced pressure at 70 ° C. for 1 hour.
Next, after adding and mixing an antioxidant, a heat stabilizer and a chlorine scavenger, the mixture was extruded at 250 ° C. using a 20 mmφ extruder to obtain a pellet, which was subjected to physical property measurement. The results are shown in Table 1. FIG. 1 shows an elution curve obtained by a temperature separation method.

Example 2 The same operation as in Example 1 was carried out except that the addition amount of ethylaluminum sesquiethoxide was changed to 0.35 in the main polymerization of Example 1. The results are shown in Table 1.

Example 3 In the second stage of the main polymerization of Example 1, the polymerization time was 40
The same operation as in Example 1 was performed except that the time was changed to minutes. The results are shown in Table 1.

Example 4 The same operation as in Example 1 was carried out except that the amount of butyl acetate used in the second stage of the main polymerization in Example 1 was changed to 0.14 mmol. The results are shown in Table 1.

Examples 5 and 6 The amount of butyl acetate used in the second stage of the main polymerization in Example 1 was 0.14 mmol, and 1,3-bis (t-
Butyl peroxyisopropyl) benzene at 0.006
The same operation as in Example 1 was performed except that the weight% (Example 4) and 0.01% by weight were used. The results are shown in Table 1.

Example 7 In the main polymerization of Example 1, diethyl aluminum (2,6-) was used instead of ethyl aluminum sesquiethoxide.
Example 1 except that di-t-butylphenoxide) was used.
The same operation as described above was performed. The results are shown in Table 1.

Example 8 The same operation as in Example 1 was carried out except that methyl methacrylate was used in place of butyl acetate in the main polymerization of Example 1. The results are shown in Table 1.

Example 9 The same operation as in Example 1 was performed except that dicyclopentyltyldimethoxysilane was used instead of butyl acetate in the main polymerization of Example 1. The results are shown in Table 1.

Example 10 In the main polymerization of Example 1, the polymerization time of the first stage was 90
And the amount of butyl acetate used in the second stage is 0.14
The same operation as in Example 1 was performed except that the amount was changed to mmol.
The results are shown in Table 1.

Example 11 In the main polymerization of Example 1, the first stage polymerization was carried out at a hydrogen concentration of 0.2 mol%, and the second stage polymerization was carried out at a hydrogen concentration of 5 m
The same operation as in Example 1 was performed, except that ol% was used. The results are shown in Table 1.

Comparative Example 1 In the main polymerization of Example 1, the same operation as in Example 1 was performed except that ethylaluminum sesquiethoxide was not used. The results are shown in Table 1.

Comparative Examples 2 and 3 In the second stage of the main polymerization of Example 1, polymerization was carried out without using hydrogen, and 0.1% by weight of 1,3-bis (t-butylperoxyisopropyl) benzene was added during granulation. % (Comparative Example 2)
The same operation as in Example 1 was performed except that 0.2% by weight and Comparative Example 3 were used. The results are shown in Table 1.

Comparative Example 4 The amount of butyl acetate used in the main polymerization of Example 1 was 0.0
The same operation as in Example 1 was performed except that the amount was changed to 07 mmol. The results are shown in Table 1.

Comparative Example 5 In the main polymerization of Example 1, the polymerization time of the second stage was 20
And the same operation as in Example 1 was performed except that 0.003% by weight of 1,3-bis (t-butylperoxyisopropyl) benzene was used during granulation. The results are shown in Table 1.

Comparative Example 6 In the main polymerization of Example 1, the same operation as in Example 1 was performed except that the polymerization time in the first stage was 1 hour and the amount of butyl acetate used was 0.0035 mmol. The results are shown in Table 1.

Comparative Example 7 In the main polymerization of Example 1, the same operation as in Example 1 was carried out except that 0.014 mmol of butyl acetate was used in the polymerization in the first stage. The results are shown in Table 1.

Comparative Example 8 In the main polymerization of Example 1, no ethyl aluminum sesquiethoxide was used, the polymerization time in the first step was 30 minutes, and the amount of butyl acetate used in the second step was 0.14 mm.
The same operation as in Example 1 was performed except that the amount was changed to ol. The results are shown in Table 1.

[0088]

Sheet Production Example 1 The low-crystalline polypropylene pellets obtained in Example 1 were extruded at a die temperature of 230 ° C. by a T-die film forming machine equipped with an extruder having a screw diameter of 40 mmφ, and cooled at a roll cooling temperature of 30 ° C. Then, a sheet having a thickness of 0.5 mm was obtained. Table 2 shows the physical properties of the obtained sheet.

Sheet Production Examples 2 to 11 Sheets of the low crystalline polypropylene pellets obtained in Examples 2 to 11 were formed in the same manner as in Sheet Production Example 1. Table 2 shows the physical properties of the obtained sheet.

[0091]

[Table 1]

[0092]

[Table 2]

[Brief description of the drawings]

FIG. 1 is an elution curve of a low-temperature polypropylene elution fractionation method of low-crystalline polypropylene of Example 1.

Claims (3)

[Claims] 1. A propylene homopolymer or a copolymer of propylene and an α-olefin having a content of α-olefin units other than propylene of 5 mol% or less, wherein (1)
(2) a molecular weight distribution (M _w / M _n ) represented by a ratio of a weight average molecular weight (M _w ) to a number average molecular weight (M _n ) of 4 to 15, 3) In the elution curve, the horizontal axis of which is the elution temperature (° C.) and the vertical axis which is the cumulative weight ratio of the eluting components, which has been fractionated by the temperature rising elution fractionation method,
The amount of the eluting component (component A) at less than 20 ° C is 5 to 35% by weight, the amount of the eluting component (component B) at 20 ° C or more and less than 100 ° C is 10 to 40% by weight, and the eluting component at 100 ° C or more. (C
Component) is 40 to 80% by weight, the total of the A component, the B component and the C component is 100% by weight, the weight ratio (B / A) of the B component and the A component is 0.6 or more, and A low crystalline polypropylene having a peak top temperature of 120 ° C. or higher. 2. The low crystalline polypropylene according to claim 1, wherein the deflection temperature under load is 50 ° C. or higher. 3. A film or sheet comprising the low-crystalline polypropylene according to claim 1 or 2.