JPH1017736A - Modified propylene (co) polymer composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject composition, capable of improving the strength when melted and excellent in moldability by irradiating a propylene (co)polymer composition, prepared in the presence of a previously activated catalyst and having a high melt tension with ionizing radiation. SOLUTION: This modified propylene (co)polymer composition is obtained by irradiating a polypropylene (co)polymer composition, comprising (A) 0.01-5 pts.wt. of a copolymer of an olefin-dialkenylsilanes and (B) 100 pts.wt. of a propylene homopolymer or a copolymer of propylene and other olefins and having a high melt tension with ionizing radiation (preferably γ-rays or electron beams) and then heat-treating the radiated composition. The dose of the ionizing radiation is preferably 0.1-100kGy. Furthermore, the propylene-based (co)polymer is synthesized by using a previously activated catalyst obtained by carrying out the previous activating treatment of an organometallic compound catalyst component comprising a transition metallic catalyst component and a metal selected from groups I to III of the periodic table with an olefin and dialkenylsilanes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a modified propylene (co) polymer composition, and more particularly to a modified propylene (co) polymer composition having excellent moldability and a method for producing the same.

[0002]

2. Description of the Related Art Crystalline propylene polymers are widely used in various molding fields because they are excellent in mechanical properties, chemical resistance and the like, and are extremely useful in balance with economic efficiency.
However, the melt tension is insufficient, and the moldability such as hollow molding, foam molding, extrusion molding, and thermoforming may be poor.

As a method for increasing the melt tension and crystallization temperature of a crystalline propylene polymer, a method is known in which an organic peroxide and a crosslinking aid are mixed with crystalline polypropylene, and the mixture is melt-kneaded by an extruder (Japanese Patent Laid-Open Publication No. JP-A-59-93711 and JP-A-61-152754), but the use of the crystalline polypropylene composition to be treated obtained by the method is limited because a crosslinking aid is used.

On the other hand, JP-A-2-298536 discloses a method of irradiating a semi-crystalline polypropylene with an electron beam in the absence of oxygen to obtain a gel having no free-end long-chain branch and containing no gel. Have been. However, since semi-crystalline polypropylene is used, the rigidity and other physical properties of the molded product may be poor.

[0005]

As described above, the propylene polymer obtained by the method of the known invention and having a higher melt tension and a higher crystallization temperature has a limited use because of the use of a crosslinking aid. There was a problem that the efficiency of reforming by wire was not so high.

The present inventors have conducted intensive studies in order to find a polypropylene resin which does not have the problems of the above-mentioned known art, is easy to produce, and has no problem of poor moldability due to insufficient melt tension. As a result, a so-called Ziegler-Natta catalyst, that is, a catalyst comprising a transition metal catalyst component and an organometallic compound catalyst component of a Group I to Group III metal of the periodic table is preactivated with an olefin and dialkenylsilanes. The following relationship is established for the propylene polymer composition or propylene / olefin copolymer composition obtained by polymerizing propylene or copolymerizing propylene with another olefin using the preactivated catalyst obtained in I understood. That is, the propylene polymer composition or the propylene / olefin copolymer composition
C. and the intrinsic viscosity [η] (135)
C., in tetralin) and log (MS)> 4.24 log [η] −0.962 (I), and a higher melt tension than that of a normal one was obtained (described later). Formula (II)). In the present invention, the propylene polymer composition or the propylene / olefin copolymer composition is further irradiated with a required amount of ionizing radiation to further improve the strength and moldability of the modified propylene polymer when melted. The present inventors have found that a coalesced composition or a modified propylene / olefin copolymer composition can be obtained, and have reached the present invention. As is apparent from the above description, an object of the present invention is to improve the strength at the time of melting to solve the problems of the above-mentioned known invention and to be suitable for hollow molding, foam molding, extrusion molding, thermoforming and the like. It is an object of the present invention to provide a high-quality propylene (co) polymer composition and a method for producing the same.

[0007]

Means for Solving the Problems The present invention provides the following (1)-
It has each configuration of (6).

(1) (a) 0.01 to 5 parts by weight of an olefin-dialkenylsilane copolymer, and (b) 100 parts by weight of a propylene homopolymer or a copolymer of propylene and another olefin. Propylene (co) polymer composition obtained by irradiating ionizing radiation to a propylene (co) polymer composition having a high melt tension
Polymer composition.

(2) The ionizing radiation is a gamma ray or an electron beam, and the dose of the ionizing radiation is 0.1 to 100 kGy.
The composition according to the above (1), which is:

(3) The composition according to the above (1) or (2), wherein the weight ratio of the polymerized dialkenylsilane unit to the polymerized olefin unit in the olefin-dialkenylsilane copolymer is 0.001 to 50%. Stuff.

(4) An organic metal compound catalyst component (RM1) containing a transition metal compound catalyst component, a metal selected from Groups I to III of the periodic table, and, if necessary, an electron donor (E1). Under the combined catalyst system,
An olefin and dialkenylsilane are copolymerized in an amount of 0.01 g to 5000 g per 1 g of the transition metal compound catalyst component to prepare a pre-activated catalyst [I] for producing a propylene (co) polymer, and the [I] propylene ( A catalyst for producing a propylene (co) polymer comprising a preactivated catalyst for producing a (co) polymer, [II] an organometallic compound catalyst component (RM2) and, if necessary, [III] an electron donor (E2). Propylene homopolymerization or copolymerization of propylene with other olefins in the presence of
Propylene (co) weight having a high melt tension consisting of 0.01 to 5 parts by weight of a dialkenylsilane copolymer and (b) 100 parts by weight of a propylene homopolymer or a copolymer of propylene and another olefin. A method for producing a modified propylene (co) polymer composition, comprising producing a coalesced composition, further irradiating the composition with ionizing radiation, and then subjecting the composition to heat treatment.

(5) The ionizing radiation is a gamma ray or an electron beam, and the dose of the ionizing radiation is 0.1 to 100 kGy.
The method for producing the composition according to the above (4), wherein

(6) The weight ratio of polymerized units of dialkenylsilane to polymerized units of olefin in the olefin-dialkenylsilanes copolymer contained in the preactivated catalyst [I] for producing a propylene (co) polymer is 0. The method for producing the composition according to the above (4) or (5), wherein the composition is 0.01 to 50%.

The configuration and effect of the present invention will be described in detail below. The term “propylene (co) polymer” used in the present invention means not only a propylene homopolymer but also a propylene-olefin random copolymer in which the polymer contains 30% by weight or less of olefin polymerized units other than propylene. And a propylene-olefin block copolymer, and the description of a propylene (co) polymer is used in this sense hereinafter.

The modified propylene (co) polymer composition of the present invention can be obtained by irradiating a propylene (co) polymer composition having a high melt tension with ionizing radiation. It is essential that the propylene (co) polymer composition has a higher melt tension than the melt tension of the generally known linear propylene polymer obtained without performing the preactivation of the present invention. The relationship between the melt tension (MS) at 230 ° C. of a generally known linear propylene polymer obtained without preactivation of the present invention and the intrinsic viscosity [η] measured at 135 ° C. in tetralin. Was found to have a relationship represented by log (MS) = 4.24 log [η] -1.217 (II). Therefore, the propylene (co) polymer composition having a high melt tension has a high melting point of 23.
Melt tension (MS) at 0 ° C and 135 in tetralin
The relationship with the intrinsic viscosity [η] measured at ° C is calculated by the above formula (II)
Needless to say, the relationship represented by the following expression must be satisfied, but the relationship must be expressed by the following equation: log (MS)> 4.24 × log [η] −0.962 (I) By further irradiating such a propylene (co) polymer composition with ionizing radiation, the moldability is further improved and the remarkable effects of the present invention can be obtained.

In the present invention, the melt tension (MS) at 230 ° C. is measured by using a melt tension tester type 2 manufactured by Toyo Seiki Seisaku-sho, Ltd.
The melted resin is extruded from a nozzle having a diameter of 2.095 mm into the atmosphere at 23 ° C. at a speed of 20 mm / min to form a strand, and the tension of the filamentous resin when the strand is taken off at a speed of 3.14 m / min. Was measured and defined as a melt tension (MS).

The preactivated catalyst [I] for producing a propylene (co) polymer used in the present invention is an organometallic compound containing a catalyst component of a transition metal compound and a metal selected from Groups I to III of the periodic table. It is produced by copolymerizing an olefin and a dialkenylsilane compound under a catalyst system comprising a combination of a catalyst component (RM1) and, if necessary, an electron donor (E1). The dialkenyl silanes used here are not particularly limited, but specifically, dimethyl diallyl silane, diallyl silane, dimethyl divinyl silane, dimethyl dibutenyl silane, dibutenyl silane, dimethyl dipentenyl silane, dipentenyl silane, etc. Among them, dimethyldiallylsilane is particularly preferred. These dialkenylsilanes can be used alone or in combination of two or more.

The olefin used here is not particularly limited, but an olefin having 2 to 12 carbon atoms is preferably used. Specifically, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1
-Octene, 1-decene, 4-methyl-1-pentene,
3-methyl-1-pentene and the like, among which ethylene, propylene, 1-butene, and 4-methyl-
More preferably, 1-pentene is used, and even more preferably, ethylene is used. These olefins can be used alone or in combination of two or more. Is a preferred embodiment of the present invention.

When two or more olefins are used, the main olefin in all olefin components excluding dialkenylsilanes in the olefin-dialkenylsilanes copolymer formed by preactivation is 50 to 99. 99
It is preferable to adjust the amount of the two or more olefins so that the amount is at least 70% by weight, preferably 70 to 99.99% by weight, particularly preferably 90 to 99.99% by weight.

The preactivation performed in obtaining the preactivated catalyst [I] for producing a propylene (co) polymer used in the present invention is carried out in an amount of 0.01 g to 5000 g per 1 g of the catalyst component of the transition metal compound. To produce an olefin-dialkenylsilane copolymer. The content of the polymerized units of the dialkenylsilane in the olefin-dialkenylsilanes copolymer is 0.001% by weight in view of the effect of improving the melt tension of the propylene (co) polymer composition finally obtained. % To 50% by weight. More preferably, it is 0.005% to 40% by weight, most preferably 0.01% to 30% by weight.

The pre-activation of the catalyst by olefin-dialkenyl silane copolymerization is performed by converting the catalyst component of the transition metal compound to the transition metal atom in the catalyst component in an amount of 0.001 to 5000 mmol per liter of polymerization volume. , Preferably 0.01 to 1000 mmol. Also,
The organometallic compound containing a metal selected from Groups I to III of the periodic table is used in an amount of 0.01 to 1000 moles, preferably 0.0 moles, per mole of the transition metal in the transition metal catalyst component.
The solvent is used in an amount of 5 to 500 moles and 0 to 100 liters of the solvent for 1 g of the transition metal compound catalyst component. Incidentally, the preactivation is performed by using aliphatic hydrocarbons such as butane, pentane, hexane, heptane, octane, isooctane, decane and dodecane; alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane; toluene, xylene, and ethylbenzene. It can be performed in an inert solvent such as an aromatic hydrocarbon, gasoline fraction or hydrogenated diesel oil fraction, or in a liquid phase using olefin itself as a solvent. It is also possible to do it inside.

The conditions for the preactivation are 0.01 g to 5000 g per 1 g of the transition metal compound catalyst component.
(A) A propylene (co) polymer composition which produces an olefin-dialkenylsilane copolymer and has a content of polymerized units of dialkenylsilanes in the olefin-dialkenylsilane copolymer which is obtained. From the viewpoint of the effect of improving the melt tension, any preactivation condition may be used as long as it is 0.001% by weight to 50% by weight. However, -40 ° C ~
At a temperature of 40 ° C, preferably -20 ° C to 30 ° C, more preferably -10 to 25 ° C, 0.1 MPa to 5 MPa, preferably 0.11 to 4.5 MPa, particularly preferably 0.1 to 4.5 MPa.
It is desirable to carry out preliminary activation under a pressure of 12 MPa to 4.0 MPa for 1 minute to 24 hours, preferably 5 minutes to 18 hours, particularly preferably 10 minutes to 12 hours.

Before or after the above-mentioned preactivation, it is also possible to additionally perform a preactivation treatment with an olefin at a reaction amount of 100 g or less per 1 g of the transition metal compound catalyst component. The amount of the organic metal compound and the solvent used at this time is suitably in the same range as in the above-mentioned preactivation by copolymerization of the olefin-dialkenylsilanes according to the present invention. The organometallic compound used for the additional preactivation, the type of solvent, and the electron donor used if necessary, are the olefins of the present invention.
The same ones as those for the preactivation by copolymerization of dialkenylsilanes can be used.

Preactivated catalyst [I] used in the present invention
Examples of the transition metal compound catalyst component used in the production of the compound include compounds containing a transition metal selected from Groups III to VIII of the periodic table.
Examples include compounds containing one or more transition metals selected from i, Zr, Hf, Nb, Ta, Cr and V.

Examples of such a transition metal compound catalyst component include known catalyst components for olefin polymerization. Specific examples include a titanium compound, a magnesium compound, and, if necessary, oxygen and nitrogen in the molecule. , Phosphorus, a supported catalyst component obtained by contacting an electron donor containing at least one of sulfur, titanium, magnesium, halogen and, if necessary, an electron donor, and reduction of titanium tetrachloride. And a titanium trichloride-based catalyst component obtained by contacting the obtained titanium trichloride composition with a tetravalent titanium compound and / or an electron donor. Further, a metallocene compound obtained by contacting a cyclopentadienyl compound with a transition metal compound can also be used. As the metallocene compound, an inorganic compound such as SiO ₂ or Al ₂ O ₃ or a compound supported on a polymer compound such as polyethylene or polypropylene can be used.

Further, an organometallic compound catalyst component containing a metal selected from Groups I to III of the periodic table, which is another component used in producing the above preactivated catalyst [I]. [RM1] is preferably an organoaluminum compound or a boron-based organometallic compound. As the organoaluminum compound, the following general formulas [1], [2],
The compound of [3] is mentioned.

[0027]

Embedded image (Wherein R ¹ and R ² represent a hydrocarbon group or an alkoxy group, X represents a halogen, and p and q represent 0 <p + q ≦ 3
Represents an arbitrary integer. )

[0028]

Embedded image

[0029]

Embedded image (In the formula, R ³ represents a hydrocarbon group, and p represents an integer of 4 to 30.)

Specific examples of the organoaluminum compound of the general formula [1] include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, and tri-n-aluminum.
Trialkylaluminum such as -butylaluminum, tri-n-hexylaluminum, triisohexylaluminum, tri-n-octylaluminum, diethylaluminum chloride, di-n-propylaluminum chloride, diisobutylaluminum chloride, diethylaluminum bromide, diethylaluminum iodide, etc. Dialkylaluminum monohalide, dialkylaluminum hydride such as diethylaluminum hydride, alkylaluminum sesquihalide such as ethylaluminum sesquichloride,
Monoalkylaluminum dihalides such as ethylaluminum dichloride and the like can be mentioned. Other examples include alkoxyalkylaluminums such as diethoxymonoethylaluminum. Preferred among these are trialkylaluminum and dialkylaluminum monohalides. These organoaluminum compounds can be used alone or in combination of two or more.

As specific examples of the organoaluminum compounds of the general formulas [2] and [3], R ³ is a methyl group, an ethyl group,
Alkyl group such as propyl group, butyl group, isobutyl group, pentyl group, hexyl group, allyl group, 2-methylallyl group, propenyl group, isopropenyl group, 2-methyl-1
-A compound such as an alkenyl group such as a propenyl group or a butenyl group, a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a cyclohexyl group, and an aryl group. Among these, an alkyl group is particularly preferred, and each R ³ may be the same or different. P is an integer of 4 to 30, preferably 6 to 30, and particularly preferably 8 to 30.

The organometallic compound catalyst component [RM1] containing a metal selected from Groups I to III of the periodic table
In addition to the organoaluminum compound, a boron-based organometallic compound is also suitable, and this boron-based organometallic compound is obtained by reacting a transition metal compound with an ionic compound containing a boron atom. As the transition metal compound used at this time, those similar to the transition metal compound catalyst component used in producing the preactivated catalyst [I] can be used, but cyclopentadienyl is preferably used. A metallocene compound obtained by contacting a compound with a transition metal compound. Examples of the ionic compound containing a boron atom include triethylammonium tetrakis (pentafluorophenyl) borate,
Tetrakis (pentafluorophenyl) borate tri-n-
Butylammonium, triphenylammonium tetrakis (pentafluorophenyl) borate, methylanilium tetrakis (pentafluorophenyl) borate, dimethylanilium tetrakis (pentafluorophenyl) borate, trimethylanilium tetrakis (pentafluorophenyl) borate, and the like. .

Further, as the electron donor [E1] optionally used in producing the above preactivated catalyst [I], one or more of oxygen, nitrogen, phosphorus and sulfur are contained in the molecule. And specifically, an organosilicon compound having an Si—O bond, an ester, an ether and the like are preferably used.

The preactivated catalyst [I], an organometallic compound catalyst component (RM2) containing a metal selected from Groups I to III of the Periodic Table (RM2) and, if necessary, [III
The propylene (co) polymer composition can be obtained by homopolymerizing propylene or copolymerizing propylene with another olefin using a catalyst comprising a combination of an electron donor [E2].

(B) The propylene homopolymer or the copolymer of propylene and other olefins may be propylene homopolymer, random copolymerization of propylene with other olefins, homopolymerization of propylene, or olefins other than propylene. After copolymerization of propylene with a small amount of olefins other than propylene such that the amount becomes 3% by weight or less, random copolymerization of propylene with olefins other than propylene is performed, that is, so-called block copolymerization.

The olefin other than propylene used in the polymerization of the propylene copolymer is not particularly limited, but an olefin having 2 to 12 carbon atoms is preferably used. Specifically, ethylene, butene-1, pentene-
Linear olefins such as 1, hexene-1, heptene-1 and octene-1; branched monoolefins such as 4-methylpentene-1 and 2-methylpentene-1; and styrenes. Among them, it is more preferable to use ethylene, 1-butene, and 4-methyl-1-pentene, and most preferably, an embodiment using ethylene.

The olefins other than propylene used in the copolymerization may be contained not only in one kind but also in two or more kinds. Specifically, propylene-ethylene copolymerization,
Propylene-butene-1 copolymer, propylene-hexene-1 copolymer, propylene-octene-1 copolymer, propylene-4-methylpentene-1 copolymer, propylene-ethylene-butene-1 copolymer, propylene-ethylene-4
-Methylpentene-1 copolymer, propylene-ethylene-
Hexene-1 copolymer, propylene-ethylene-octene-1 copolymer and the like can be mentioned. The content of olefins other than propylene in the propylene copolymer is not particularly limited, but is preferably 30% by weight or less from the viewpoint of exhibiting the essential characteristics of the propylene polymer.

In order to obtain the propylene (co) polymer composition used in the present invention, it is selected from Group I to Group III of the periodic table required together with the preactivated catalyst [I] described in detail above. [II] As the organometallic catalyst component (RM2),
The same organometallic compound catalyst component (RM1) containing a metal selected from Groups I to III of the periodic table used to obtain the preactivated catalyst [I] can be used. Specifically, organoaluminum compounds such as trialkylaluminum, dialkylaluminum halide halide, alkylaluminum sesquihalide, and aluminoxane are preferably used.

Examples of the [III] electron donor [E2] used if necessary include compounds containing at least one of oxygen, nitrogen, phosphorus and sulfur in the molecule. Organosilicon compounds having an -O bond, esters, ethers and the like are preferably used.

The above preactivated catalyst [I], [II] an organometallic compound catalyst component (RM2) containing a metal selected from Groups I to III of the periodic table, and if necessary, [II]
I] Slurry polymerization in which homopolymerization of propylene or copolymerization of propylene and another olefin is carried out in an inert solvent using a catalyst comprising a combination of an electron donor [E2], and bulk polymerization using propylene itself as a solvent. A propylene (co) polymer composition obtained by performing polymerization, a gas phase polymerization mainly using propylene gas, or a known polymerization method combining these, is used as the propylene (co) polymer composition used in the present invention. It is.

In any of the above polymerization processes, the polymerization conditions are not particularly limited, but the polymerization temperature is 2
0 ° C to 120 ° C, preferably 30 to 100 ° C, particularly preferably 40 to 100 ° C, and the polymerization pressure is 0.1 MPa
The polymerization is preferably carried out continuously, semi-continuously or batchwise in a range of from 5 MPa to 5 MPa, preferably from 0.3 MPa to 5 MPa, with a polymerization time of about 5 minutes to 24 hours. In addition, the fact that the molecular weight of the obtained polymer can be adjusted by using hydrogen during the polymerization is the same as in the known olefin polymerization method. Further, (a) an olefin-dialkenylsilane copolymer derived from the preactivated catalyst used is (b) 100 parts by weight of a propylene homopolymer or a copolymer of propylene and another olefin, It is a more preferable embodiment that the polymerization conditions are selected so as to be 0.01 parts by weight to 5 parts by weight to exert the effect of the present invention.

The powder of the propylene (co) polymer composition used in the present invention may be melt-kneaded by a melt-kneading machine, subsequently cut into granules, pelletized, and used for various purposes. As the melt kneader, a known ordinary melt kneader is used. For example, a single screw extruder,
Twin screw extruders, extruders combining these with gear pumps, Brabender, Banbury mixers and the like. In addition, at the time of melt kneading, if necessary, before heating and melting, an antioxidant, an ultraviolet absorber, an antistatic agent, a nucleating agent, a lubricant, a flame retardant, an antiblocking agent, a coloring agent, an inorganic or organic filler. And various other additives.

The propylene (co) polymer composition obtained by the above method must satisfy the above-mentioned essential requirements.

The propylene (co) polymer composition thus obtained generally has a higher melt tension and a better moldability than the propylene (co) polymer resin obtained by a known method.
Suitable for hollow molding, foam molding, extrusion molding, thermoforming, etc., but not limited to the molding field, by injection molding, T-die molding, various industrial parts, various containers such as hollow containers, films, sheets, It can be used for various molded products such as pipes and fibers.

In the present invention, by irradiating the propylene (co) polymer composition with ionizing radiation, a modified propylene (co) polymer composition having more excellent moldability can be obtained. In order for the modified propylene (co) polymer composition of the present invention to be more excellent in hollow molding, extrusion molding, thermoforming, foam molding and the like than the above-mentioned propylene (co) polymer composition, the modified propylene (co) polymer It is essential that the strength of the polymer composition at the time of melting be further improved as compared with the propylene (co) polymer composition described above.

Specifically, the relationship between the melt tension (MS) at 230 ° C. and the intrinsic viscosity [η] measured in tetralin at 135 ° C. is expressed as log (MS)> 4.24 × log [η] −0. .740 (I ′). However, strictly speaking, the preferred melting strength differs depending on the application,
It may not be possible to evaluate with the above melt tension.
For example, in foam molding and the like, a large amount of a gel component is generated by adjusting irradiation conditions such as an ionizing radiation irradiation dose, and the moldability may be improved by changing the strength at the time of melting extremely. is there. As described above, when the generation amount of the gel component is large, the melt tension cannot be measured, and the improvement of the strength at the time of melting cannot be expressed by the relational expression between the melt tension and the intrinsic viscosity as described above. As long as the performance is improved, it does not fall outside the scope of the present invention.

The ionizing radiation used in the present invention includes:
Examples include α-rays, β-rays, γ-rays, X-rays, and electron beams. Preferred are γ-rays and electron beams, and most preferred in practice is electron beams. Although the irradiation dose rate of these ionizing radiations is not particularly defined, in the case of γ-rays, the irradiation dose rate is about 2.6 × 10 ⁻² C · kg ⁻¹ / h. Irradiation at an irradiation dose rate of 500 times or more of the line becomes possible. An electron beam that can be irradiated at a high dose rate is economically preferable because a large amount of the modified propylene (co) polymer composition can be obtained in a short time.

The dose of the ionizing radiation absorbed by the propylene (co) polymer composition is not particularly limited.
From the viewpoint of improvement in strength at the time of melting and economical efficiency, 0.1 to 100
The range of kGy is appropriate, and more preferably 0.5 kGy.
８０80 kGy, most preferably 1-60 kGy. Since the required intensity at the time of melting varies depending on the application, the dose of the ionizing radiation to be absorbed is adjusted according to the intensity. However, the above dose range is sufficient for all applications. However, within that range, foam molding tends to require higher doses than other applications.

Here, (Gy) is usually defined as the amount of ionizing radiation that causes the absorption of 1 J of energy per 1 kg of the irradiation object irrespective of the radiation source. In the present invention, the absorbed dose is not directly measured, but means that the dose is absorbed by a known ordinary dosimeter placed on the surface of the irradiation object and is equivalent to the measured and displayed dose.

The temperature at which the propylene (co) polymer composition is irradiated with ionizing radiation is -10 to 80 ° C, preferably-
A range of 5 to 60C, particularly preferably 0 to 50C is suitable. In addition, the irradiation can be performed in the air as an atmosphere. However, in view of the controllability of the intrinsic viscosity of the resulting modified propylene (co) polymer composition and the improvement of the melt viscoelasticity, it is inactive. It is preferable to carry out in a gas atmosphere, for example, in a nitrogen atmosphere.

In the method of the present invention, the object to be irradiated after the above-mentioned irradiation with ionizing radiation is subsequently subjected to a heat treatment at 80 to 300 ° C. The heat treatment is performed for the purpose of eliminating residual radicals in the irradiation object.
The embodiment is preferably performed by using a melt kneader at 190 to 350 ° C, more preferably 190 to 300 ° C, and most preferably 200 to 200 ° C.
This means that the mixture is heated and melt-kneaded at 80 ° C. The melt-kneading time varies depending on the melt-kneader and is not specified.
About 0 seconds to 30 minutes is sufficient. Usually, after melt kneading,
Subsequently, it is cut into granules and pelletized. As the melt kneader, a known ordinary melt kneader is used.
For example, a single-screw extruder, a twin-screw extruder, an extruder combining these with a gear pump, a Brabender, a Banbury mixer, and the like. In addition, at the time of melt-kneading, if necessary, before heating and melting, an antioxidant, an ultraviolet absorber, an antistatic agent,
Various additives such as a nucleating agent, a lubricant, a flame retardant, an antiblocking agent, a coloring agent, and an inorganic or organic filler can be compounded.

As another embodiment of the heat treatment, 80 to 150
There is a method of performing heat treatment at a temperature of 100 ° C, more preferably 100 to 150 ° C. The embodiment relates to the resulting modified propylene (co)
This is a preferred embodiment when the polymer composition is used in the form of a powder for the production of molded articles. Furthermore, 80-150
A further preferred embodiment of the present invention is a method of melting and kneading at 190 to 350 ° C. after the heat treatment at 90 ° C.

The above heat treatment can be carried out in the air, but it is difficult to control the intrinsic viscosity of the resulting modified propylene (co) polymer composition and to improve the strength at the time of melting. It is more preferable to carry out in an active gas atmosphere, for example, in a nitrogen atmosphere. If the heat treatment is not performed, the resulting modified propylene (co) polymer composition will be unstable with large deterioration over time.

In order to achieve the object of the present invention, the modified propylene (co) polymer composition obtained by
Must have the required requirements mentioned above.

The thus obtained modified propylene (co) polymer composition of the present invention has improved strength upon melting and excellent moldability, and is particularly suitable for hollow molding, foam molding, extrusion molding, thermoforming and the like. However, not limited to the molding field, it can be used for various molded parts such as various industrial parts, various containers such as hollow containers, films, sheets, pipes and fibers by injection molding and T-die molding. it can.

[0056]

Next, the present invention will be described specifically with reference to examples. Definitions of terms used in Examples and Comparative Examples and measurement methods are as follows. (1) Intrinsic viscosity: [η], measured by the method described.
(Unit: dl / g) (2) Melt tension: (MS), measured by the method described. (Unit: cN)

Example 1 "Preparation of preactivated catalyst [I]" 200 ml of purified hexane, 3 mmol of triethylaluminum and 3 mmol of triethylaluminum were placed in a 1000 ml reactor equipped with a stirrer and equipped with a stirrer under a nitrogen gas atmosphere. After adding 1.1 mmol in terms of titanium atoms of the magnesium chloride-supported titanium catalyst component obtained by the method described in Example 1 in No. 104812, propylene was added at a temperature of 25 ° C. under a pressure of 0.13 MPa for 73 minutes. 6.6 g of propylene was polymerized by feeding into this reactor. When the supply of propylene was completed, the inside of the reactor was replaced with nitrogen, and the operation consisting of removing the supernatant and adding purified hexane was performed three times, and then resuspended in 200 ml of purified hexane. 7.0 aluminum ethoxide
30 mmol of dimethyldiallylsilane was added. Thereafter, ethylene was pressured at 0.17 MPa, 20
The copolymerization with dimethyldiallyl silane was carried out by feeding at 100 ° C. for 100 minutes until 25.2 grams of ethylene had reacted. When the supply of ethylene is over,
The inside of the reactor was replaced with nitrogen, and a washing operation including removal of the supernatant and addition of purified hexane was performed 5 times, and then resuspended in 200 ml of purified hexane to obtain a preactivated catalyst [I].

"Production of propylene polymer composition" In a 3 liter autoclave, 1500 ml of purified hexane and 3.0 ml of triethylaluminum were placed under a nitrogen gas atmosphere.
Mmol, 0.3 mmol of diisopropyldimethoxysilane and the pre-activated catalyst [I] in an amount of 0.
After the introduction of 042 mmol, 300
propylene was supplied for 60 minutes while maintaining the pressure of the reactor at 0.79 MPa. After completion of the polymerization, the solid including the produced solid was filtered to separate into a white powder and a liquid phase. After drying this white powder, 346 g of a propylene polymer composition was obtained.

"Irradiation of the propylene polymer composition powder with an electron beam" The powder of the obtained propylene polymer composition was placed in a polyethylene terephthalate bag equipped with a cock.
00g was put. Then, the operation of evacuating the inside of the bag and supplying nitrogen gas to atmospheric pressure is repeated 10 times to make the inside of the bag a nitrogen gas atmosphere so that the thickness of the propylene polymer composition becomes 1 cm on the electron beam irradiation conveyor. The bag was fixed. Electron beam irradiation was performed using a Cockcroft-Walton type electron beam accelerator. A propylene polymer was placed 20 cm below the irradiation window in a polyethylene terephthalate bag on a conveyor under the conditions of an acceleration voltage of 2 MV and a current value of 1.0 mA. By passing the composition through a conveyor so that the absorbed dose is 10.0 kGy (conveyor speed: 0.9
7 m / min). The temperature during irradiation at this time is 25 ° C
Met. Subsequently, the propylene polymer composition after the electron beam irradiation is brought into an oven in a state of a nitrogen atmosphere in a bag made of polyethylene terephthalate, and heat-treated in the oven at 135 ° C. for 30 minutes. Thus, a powder of the modified propylene polymer composition was obtained.

"Granulation of modified propylene polymer composition powder" Tetrakis [methylene-3- (3'-5'-di-) was added to 100 parts by weight of the modified propylene polymer composition.
t-butyl-4'-hydroxyphenyl) propionate] methane (0.1 part by weight) and calcium stearate (0.1 part by weight) are mixed, and the mixture is mixed with a screw having a screw diameter of 15 parts.
The mixture was melt-kneaded and granulated at 230 ° C. using an extruding granulator of 2 mm to obtain a pelletized modified propylene polymer composition.

Comparative Example 1 A pelletized propylene polymer composition was obtained in the same manner as in Example 1 except that only the electron beam irradiation step of Example 1 was omitted.

Comparative Example 2 In the preparation step of the preactivated catalyst [I] of Example 1,
A pelletized propylene polymer composition was obtained in the same manner as in Example 1 except that dimethyldiallylsilane was not used and the electron beam irradiation step of Example 1 was omitted.

Comparative Example 3 A pelletized propylene polymer was prepared in the same manner as in Example 1 except that the step of preactivating with ethylene and dimethyldiallylsilane of Example 1 and the step of irradiating an electron beam were omitted. Obtained.

Comparative Example 4 In the preparation step of the preactivated catalyst [I] of Example 1,
A pelletized propylene polymer composition was obtained in the same manner as in Example 1 except that dimethyldiallylsilane was not used.

Comparative Example 5 A propylene polymer pelletized was obtained in the same manner as in Example 1 except that the step of preactivating with ethylene and dimethyldiallylsilane in Example 1 was omitted. Table 1 shows the conditions and results of Example 1 and Comparative Examples 1, 2, 3, 4, and 5 described above.

[0066]

[Table 1]

Example 2 Pellets of the modified propylene polymer composition obtained in the same manner as in Example 1 were subjected to extrusion sheeting at 260 ° C. using an extruder with a T-die and a screw diameter of 65 mm. Then, a sheet having a thickness of 0.5 mm was obtained. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was fixed to a 40 cm square frame, placed in a constant temperature room at 210 ° C., and behavior was observed. The center of the sheet began to hang down due to the heating, and when the sheet hanged down by 38 mm, the hang was stopped and, conversely, the hang down was raised. When 11 seconds had elapsed after the suspension of the drooping, the sheet began to droop again, and thereafter only drooped. The amount of droop is small and the time to start drooping again is 1
As long as one second, the sheet was found to be extremely excellent in heat vacuum formability.

Comparative Example 6 The pellets of the propylene polymer composition obtained in the same manner as in Comparative Example 1 were subjected to extrusion sheeting at 260 ° C. using an extruder having a T-die and a screw diameter of 65 mm. A sheet having a thickness of 0.5 mm was obtained. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was fixed to a 40 cm square frame, placed in a constant temperature room at 210 ° C., and behavior was observed. By heating, the center part begins to sag, and when the sheet sags 40 mm, the sag stops.
Conversely, the hanging part rose. After elapse of seven seconds from the stop of the drooping, the sheet began to droop again, and thereafter only drooped.

Comparative Example 7 Pellets of the propylene polymer composition obtained in the same manner as in Comparative Example 2 were subjected to extrusion sheeting at 260 ° C. using an extruder having a T-die and a screw diameter of 65 mm. A sheet having a thickness of 0.5 mm was obtained. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was fixed to a 40 cm square frame, placed in a constant temperature room at 210 ° C., and behavior was observed. Due to the heating, the center part begins to sag, and when the sheet sags 43 mm, the sag stops.
Conversely, the hanging part rose. Four seconds after the suspension of the drooping, the sheet began to droop again, and thereafter only drooped. Compared with Example 2, the amount of droop was large, and the time until the start of re-droop was as short as 4 seconds, and the sheet was inferior in heat vacuum formability.

Comparative Example 8 The propylene polymer pellets obtained in the same manner as in Comparative Example 3 were subjected to extrusion sheeting at 260 ° C. using an extruder with a T-die and a screw diameter of 65 mm, and a thickness of 65 mm. A 0.5 mm sheet was obtained. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was
It was fixed to a square frame of cm square and placed in a constant temperature room at 210 ° C., and behavior was observed. The center of the sheet began to hang down due to the heating, and when the sheet hanged down by 45 mm, the hang was stopped and, conversely, the hang down was raised. Three seconds after the suspension of the drooping, the sheet began to droop again, and thereafter only drooped. Compared with Example 2, the amount of droop was large, and the time until the start of re-droop was as short as 3 seconds, and the sheet was inferior in heat vacuum formability.

Comparative Example 9 The propylene polymer pellets obtained in the same manner as in Comparative Example 4 were subjected to extrusion sheeting at 260 ° C. using an extruder with a T-die and a screw diameter of 65 mm, and a A 0.5 mm sheet was obtained. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was
It was fixed to a square frame of cm square and placed in a constant temperature room at 210 ° C., and behavior was observed. The central part of the sheet began to hang down due to the heating, and when the sheet had hanged down by 48 mm, the hanging stopped and, conversely, the hanging part rose. Three seconds after the suspension of the drooping, the sheet began to droop again, and thereafter only drooped. Compared with Example 2, the amount of droop was large, and the time until the start of re-droop was as short as 3 seconds, and the sheet was inferior in heat vacuum formability.

Comparative Example 10 The propylene polymer pellets obtained in the same manner as in Comparative Example 5 were subjected to extrusion sheeting at 260 ° C. using an extruder equipped with a T-die and having a screw diameter of 65 mm. A 0.5 mm sheet was obtained. Next, in order to modelly evaluate the heat vacuum formability of the sheet, the sheet was
It was fixed to a square frame of cm square and placed in a constant temperature room at 210 ° C., and behavior was observed. The center of the sheet began to hang down due to the heating, and when the sheet hanged down by 49 mm, the hang was stopped and, conversely, the hang down was raised. Three seconds after the suspension of the drooping, the sheet began to droop again, and thereafter only drooped. Compared with Example 2, the amount of droop was large, and the time until the start of re-droop was as short as 3 seconds, and the sheet was inferior in heat vacuum formability.

[0073]

According to the present invention, a modified propylene (co) obtained by irradiating ionizing radiation to a propylene (co) polymer composition having a high melt tension produced in the presence of a preactivated catalyst. As shown in the above examples, the polymer composition is excellent in moldability because the strength at the time of melting is improved. Particularly suitable for hollow molding, foam molding, extrusion molding, thermoforming, etc., but not limited to these molding fields, injection molding, T-die molding, various industrial parts, various containers such as hollow containers, films, It can be used for various molded products such as sheets, pipes and fibers. Therefore, the field of use of the propylene-based polymer is greatly expanded.

[Brief description of the drawings]

FIG. 1 is a flow sheet illustrating a method for producing a propylene (co) polymer composition according to the present invention.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C08L 43:04) (72) Inventor Keizo Makuuchi 1233 Watanukicho, Takasaki City, Gunma Prefecture Japan Atomic Energy Research Institute Takasaki Research Institute ( 72) Inventor Fumio Yoshii 1233 Watanukicho, Takasaki City, Gunma Prefecture, Japan Atomic Energy Research Institute, Takasaki Research Institute

Claims (6)

[Claims] 1. A method comprising: (a) 0.01 to 5 parts by weight of an olefin-dialkenylsilane copolymer; and (b) 100 parts by weight of a propylene homopolymer or a copolymer of propylene and another olefin. A modified propylene (co) polymer composition obtained by irradiating a propylene (co) polymer composition having a high melt tension with ionizing radiation and subsequently subjecting it to a heat treatment. 2. The composition according to claim 1, wherein the ionizing radiation is a gamma ray or an electron beam, and the dose of the ionizing radiation is 0.1 to 100 kGy. 3. The composition according to claim 1, wherein the weight ratio of the polymerized units of the dialkenylsilane to the polymerized units of the olefin in the olefin-dialkenylsilanes copolymer is 0.001 to 50%. 4. A combination of a transition metal compound catalyst component, an organometallic compound catalyst component (RM1) containing a metal selected from Groups I to III of the periodic table, and, if necessary, an electron donor (E1). Under the above catalyst system, an olefin and a dialkenylsilane are copolymerized in an amount of 0.01 g to 5000 g per 1 g of the catalyst component of the transition metal compound to obtain a pre-activated catalyst [I] for producing a propylene (co) polymer. The [I] preactivated catalyst for the production of a propylene (co) polymer and the [II] organometallic compound catalyst component (RM
2) and, if necessary, [III] an electron donor (E
(2) propylene homopolymerization or propylene and other olefins are copolymerized in the presence of a catalyst for producing a propylene (co) polymer comprising: (a) an olefin-dialkenylsilane copolymer;
A propylene (co) polymer composition having a high melt tension, comprising: 0.1 to 5 parts by weight, and (b) 100 parts by weight of a propylene homopolymer or a copolymer of propylene and another olefin; Irradiating the object with further ionizing radiation,
A method for producing a modified propylene (co) polymer composition, which is followed by heat treatment. 5. The method according to claim 4, wherein the ionizing radiation is a gamma ray or an electron beam, and the dose of the ionizing radiation is 0.1 to 100 kGy. 6. The weight ratio of polymerized units of dialkenylsilane to polymerized units of olefin in the olefin-dialkenylsilanes copolymer contained in the preactivated catalyst [I] for producing a propylene (co) polymer is 0.1%. The method for producing the composition according to claim 4 or 5, wherein the content is from 01 to 50%.