JP2003119221A - Propylene polymer, propylene polymer composition and container made by molding the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene polymer and its composition which have a very low content of oligomer components and therefore can give molded articles suitable for molded containers of various structures, excellent in odor and taste characteristics and also in surface gloss, falling weight impact strength and handleability and useful particularly for use for dairy products such as cow's milk, milky drinks and yogurt, and which can realize an improvement in the prevention of smoking and a foreign odor in processing, and in the prevention of blocking due to stickiness after processing. SOLUTION: The propylene polymer is characterized in that it comprises one polymerized by using a metallocene catalyst and has a content of 12-30C oligomer components (Wo) of 60 ppm or less. The propylene polymer composition is obtained by blending the propylene polymer with a specified additive.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a propylene-based polymer having a very low content of an oligomer component, a propylene polymer composition, and a molded container using the same.

[0002]

BACKGROUND OF THE INVENTION Propylene polymers are widely used in various applications such as various industrial materials, various containers, daily necessities, films and fibers due to their excellent heat resistance, moldability, transparency and chemical resistance. ing. However, a propylene-based polymer obtained by polymerization in the presence of a conventional Ziegler-Natta type catalyst always has a low molecular weight component (such as an oligomer component) due to the nature of the catalyst. This low molecular weight component and the volatile component due to the residual solvent contained in the polymer not only cause smoke during processing, an offensive odor, etc., but also have an adverse effect on odor and taste even after processing, and have a blocking property due to stickiness. It is known to cause various problems such as deterioration, and the above-described phenomenon has actually been a problem. In order to solve this problem, a method of washing and removing low molecular weight components after polymerization or (Japanese Patent Publication No.
4107, JP-B-58-41283, etc.), a method of separating and removing a liquid phase portion after bulk polymerization (Japanese Patent Laid-Open No. 10-1761).
2, JP-A-10-17613, etc.) has been proposed, but the content of the oligomer component and the volatile component in the obtained copolymer is not at a sufficient level by any method, and the quality is The appearance of a superior propylene-based polymer has been desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a clean propylene polymer having improved smoke generation during processing, off-flavor, odor and taste after processing, and blocking property due to stickiness. . A second object of the present invention is to provide a propylene polymer composition containing a specific additive that improves the resin performance without affecting odor and taste, and the third object is odor. It is intended to provide a molded container having an excellent color tone without affecting the taste.

[0004]

Means for Solving the Problems As a result of various studies, the present inventors have found that when a propylene polymer polymerized with a metallocene catalyst and having a very low content of low molecular weight oligomers is used, The inventors have found that smoking, offensive odor, odor and taste after processing, and blocking properties due to stickiness are improved, and the present invention has been completed.

That is, the present invention is a propylene-based polymer polymerized by using a metallocene catalyst, which has 12 to 30 carbon atoms.
The propylene-based polymer is characterized in that the content (Wo) of the oligomer component is 60 ppm (ppm by weight) or less. The propylene polymer according to the present invention has a melting point (Tm) in the range of 110 to 155 ° C,
It is preferable that the xylene-soluble component (CXS) (unit: wt%) and the melting point (Tm) at 23 ° C. satisfy the following formula (1). Formula (1) CXS ≦ −0.05 × Tm + 7.76 (where 125 ≦ Tm ≦ 155) CXS ≦ 0.0294 × (Tm) ² −7.51 × Tm +
480.9 (where 110 ≦ Tm <125) Furthermore, the propylene-based polymer according to the present invention has a melt flow rate (MFR) in the range of 0.1 to 100 g / 10 minutes and a carbon number of 12 to 30. Content of oligomer component (Wo) (unit: ppm on weight basis, same below) and MF
It is particularly preferable that R satisfies the following formula (2). Formula (2) Wo ≦ 6 × exp (0.023 × MFR)

Further, such a propylene-based polymer is preferably a random copolymer of propylene and an α-olefin other than propylene having 2 to 20 carbon atoms. Further, specific additives such as (a) a phenolic antioxidant and / or a hindered amine stabilizer, (b) a neutralizing agent and (c) a phosphorus antioxidant are blended with such a propylene polymer. The propylene-based resin composition obtained can be used for various purposes by molding methods such as injection molding, blow molding, and thermoforming. Furthermore, the containers obtained by injection molding, blow molding, and thermoforming of the above-mentioned propylene-based resin composition are used for applications such as packing, transportation and storage of miscellaneous goods, foods, etc., and in particular, the content of oligomer components is low. Therefore, it is desirable to be used for packaging and preserving foods where odor and taste are a problem.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the propylene-based polymer means a propylene homopolymer or a propylene / ethylene and / or a copolymer having 4 to 20 carbon atoms. Among them, propylene homopolymer and random copolymer of propylene and ethylene are preferable. In the case of a random copolymer of propylene and ethylene, the propylene unit is preferably 90 to 99.5% by weight, more preferably 92 to 99% by weight, and the ethylene unit is preferably 0.5 to 10% by weight, further preferably 1
.About.8% by weight.

<Physical Properties of Propylene Polymer> The propylene polymer of the present invention has a content (Wo) of an oligomer component having 12 to 30 carbon atoms of 60 ppm or less, preferably 30.
It is a propylene-based polymer of ppm or less, and more preferably 15 ppm or less. The oligomer component having 12 to 30 carbon atoms is mainly a low molecular weight oligomer produced during polymerization, but in the case of a resin composition containing various additives or a molded article thereof, not only the low molecular weight oligomer produced during polymerization but also , Additives and decomposed products thereof, mechanical oils mixed during molding, lubricating oils, and the like. Specifically, it refers to an oligomer having 12 to 30 carbon atoms, which can be confirmed by extraction by the analysis method described below and measurement by gas chromatography. If the amount of these components exceeds 60 ppm, smoke during molding and the odor and taste of the polymer after molding are deteriorated, which is not preferable.

The propylene polymer of the present invention has a melting point (T
m) is 110 to 155 ° C, preferably 113 to 150 ° C.
It is in the range of. Further, it is preferable that the relationship between the 23 ° C. xylene-soluble content (CXS) and the melting point (Tm) satisfies the following formula (1). Conventionally, CXS is regarded as an index showing the amount of a polymer produced by a catalyst which produces a low crystalline component, but a low melting point, particularly a melting point of 120 ° C. or lower, using a metallocene catalyst such as that of the present invention is used. In the case of the propylene-based polymer, even if the polymer has a homogeneous active point, a significant amount of CXS can be obtained due to the statistical distribution.
The ingredients arise. The following general formula of the present invention is set based on experience obtained from experimental measurement values. Formula (1) CXS (wt%) ≤ -0.05 Tm + 7.76 (where 125 ° C ≤ Tm ≤ 155 ° C) CXS (wt%) ≤ 0.0294 (Tm) ² -7.
51Tm + 480.9 (provided that 110 ° C. ≦ Tm <125 ° C.) Further, the polymer of the present invention has an MFR of 0.1 to 100 g /
It is particularly preferable that it is in the range of 10 minutes and the content (Wo) of the oligomer component having 12 to 30 carbon atoms and the MFR satisfy the following formula (2). Formula (2) Wo (ppm) ≦ 6 × exp (0.023 × MFR)

It is generally known that low molecular weight components such as oligomers are greatly influenced by the average molecular weight of polymers. If the average molecular weight is higher than a certain level,
It is less affected, but if the average molecular weight is low,
Low molecular weight components tend to increase exponentially. The above formula (2) is MF as an index showing the average molecular weight of the polymer.
R (also referred to as melt index) is used and the setting is made based on the experience obtained from experimental measurement values.

The concentration of volatile hydrocarbons having 6 to 10 carbon atoms in the propylene polymer according to the present invention is 300 ppm.
It is important that the content is (unit: ppm by weight) or less, preferably 200 ppm or less, more preferably 10 ppm or less.
It is 0 ppm or less, more preferably 50 ppm or less, and particularly preferably 30 ppm or less. Above these values, odor problems may occur. Incidentally, the volatile hydrocarbon in the present invention mainly refers to a solvent used during polymerization, a monomer, impurities derived from raw materials, etc., but in the case of a resin composition containing various additives and a molded article thereof, these In addition, it is a concept including volatile hydrocarbons derived from decomposition products such as the additive and mixed machine oil.

<Production of Propylene Polymer> In order to obtain the propylene polymer of the present invention, a metallocene catalyst is selectively used. As the metallocene catalyst, known catalysts can be used. For example, the components [A] and [B] described below can be used.
And those obtained by combining [C] used as necessary. Component [A] metallocene complex: transition metal compound of group 4 to 6 of the periodic table having at least one conjugated five-membered ring ligand Component [B] promoter: Compound [B] and metallocene complex [A] are reacted. As a result, a compound component [C] organoaluminum compound capable of activating the metallocene complex [A].

The metallocene catalyst can be used with or without being supported on a carrier, but it is preferable to use a supported metallocene catalyst. Specific examples of the carrier that supports the metallocene catalyst include silica, inorganic oxides such as alumina, and organic substances such as polypropylene polymers.
Examples thereof include those in which the component [A] is supported on a powder, or those in which the component [C] is further brought into contact with the organoaluminum compound, and the like. Further, it may or may not be preliminarily polymerized. A particularly preferred example of the supported metallocene catalyst is one in which the carrier is an ion-exchange layered silicate that also functions as a promoter. Specifically, component [A] and component [B] described below
And a component [C] which is added as required, are obtained. Component [A] metallocene complex: transition metal compound of Groups 4 to 6 of the periodic table having at least one conjugated five-membered ring ligand, component [B] cocatalyst: ion-exchangeable layered silicate component [C] organic Aluminum compound.

Specific examples of the above component [A] include:
The compound represented by the following general formula [1] can be used. Q (C ₅ H _4-a R ¹ _a ) (C ₅ H _4-b R ² _b ) MXY [1] In the above general formula [1], Q bridges two conjugated five-membered ring ligands. Represents a bondable group. M is the Periodic Table 4-6
It represents a group transition metal, and among them, titanium, zirconium, and hafnium are preferable. X and Y are each independently
Hydrogen, a halogen group, a hydrocarbon group having 1 to 20 carbon atoms, an oxygen-containing hydrocarbon group having 1 to 20 carbon atoms, a nitrogen-containing hydrocarbon group having 1 to 20 carbon atoms, a phosphorus-containing hydrocarbon group having 1 to 20 carbon atoms Alternatively, it represents a silicon-containing hydrocarbon group having 1 to 20 carbon atoms.
R ¹ and R ² are each independently a hydrocarbon group having 1 to 20 carbon atoms, a halogen group, a halogen-containing hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group, an aryloxy group, a silicon-containing hydrocarbon group, phosphorus. A hydrocarbon group containing, a hydrocarbon group containing nitrogen, or a hydrocarbon group containing boron is shown. In addition, two adjacent R ¹ or two R ² are bonded to each other to form C ₄ -C.
_It may form ₁₀ rings. a and b are 0 ≦ a ≦
4, an integer that satisfies 0 ≦ b ≦ 4.

The binding group Q bridging between the two conjugated five-membered ring ligands is, for example, an alkylene group, an alkylidene group,
Examples thereof include a silylene group and a germylene group. These may have a hydrogen atom substituted with an alkyl group, halogen or the like. Specific examples of the metallocene complex include the following compounds. (1) Methylenebis (cyclopentadienyl) zirconium dichloride (2) Methylene (cyclopentadienyl) (3,4-dimethylcyclopentadienyl) zirconium dichloride (3) Isopropylidene (cyclopentadienyl)
(3,4-Dimethylcyclopentadienyl) zirconium dichloride (4) ethylene (cyclopentadienyl) (3,5-dimethylpentadienyl) zirconium dichloride (5) methylenebis (indenyl) zirconium dichloride (6) ethylenebis ( 2-Methylindenyl) zirconium dichloride (7) ethylene 1,2-bis (4-phenylindenyl) zirconium dichloride (8) ethylene (cyclopentadienyl) (fluorenyl) zirconium dichloride (9) dimethylsilylene (cyclopentadiene) (Enyl) (tetramethylcyclopentadienyl) zirconium dichloride (10) dimethylsilylene bis (indenyl) zirconium dichloride

(11) Dimethylsilylene bis (4,5,
6,7-Tetrahydroindenyl) zirconium dichloride (12) dimethylsilylene (cyclopentadienyl)
(Fluorenyl) zirconium dichloride (13) dimethylsilylene (cyclopentadienyl)
(Octahydrofluorenyl) zirconium dichloride (14) methylphenylsilylenebis [1- (2-methyl-4,5-benzo (indenyl)] zirconium dichloride (15) dimethylsilylenebis [1- (2-methyl-
4,5-Benzoindenyl)] zirconium dichloride (16) dimethylsilylene bis [1- (2-methyl-4)
[H-azurenyl)] zirconium dichloride (17) dimethylsilylene bis [1- (2-methyl-4)
-(4-Chlorophenyl) -4H-azurenyl)] zirconium dichloride (18) dimethylsilylene bis [1- (2-ethyl-4)
-(4-Chlorophenyl) -4H-azurenyl)] zirconium dichloride (19) dimethylsilylene bis [1- (2-ethyl-4)
-Naphthyl-4H-azulenyl)] zirconium dichloride (20) diphenylsilylenebis [1- (2-methyl-
4- (4-chlorophenyl) -4H-azurenyl)] zirconium dichloride

(21) Dimethylsilylenebis [1- (2
-Methyl-4- (phenylindenyl))] zirconium dichloride (22) dimethylsilylene bis [1- (2-ethyl-4)
-(Phenylindenyl))] zirconium dichloride (23) dimethylsilylenebis [1- (2-ethyl-4)
-Naphthyl-4H-azulenyl)] zirconium dichloride (24) dimethylgermylene bis (indenyl) zirconium dichloride (25) dimethylgermylene (cyclopentadienyl)
(Fluorenyl) zirconium dichloride In addition, the same compounds as described above can be used for other Group 4, 5 and 6 transition metal compounds such as titanium compounds and hafnium compounds. These compounds may be used in combination with the catalyst component and catalyst of the present invention.

The component [B] ion-exchange layered silicate is
It is not limited to a naturally occurring product and may be an artificially synthesized product. A clay compound can be used as the ion-exchange layered silicate, and specific examples of the clay compound include, for example, the following described in "Clay Mineralogy" by Haruo Shiramizu (Asakura Shoten, 1995). Examples include layered silicates. (1) Dickite whose 1: 1 type layer is a main constituent layer,
Kaolin family such as nakrite, kaolinite, anoxite, metahalloysite, halloysite, serpentine family such as chrysotile, risaldite, antigorite (2) Montmorillonite, sauconite, beidellite whose main constituent layer is 2: 1 , Nontronite, saponite, hectorite, stemsite, smectite group, vermiculite group, vermiculite group,
Mica, illite, sericite, mica such as glauconite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group.

The silicate used in the present invention is the above-mentioned (1),
It may be a layered silicate in which the mixed layer of (2) is formed.
In the present invention, the main component silicate is preferably a silicate having a 2: 1 type layer structure, more preferably a smectite group, and particularly preferably montmorillonite. The silicate used in the present invention can be used as it is without any particular treatment, but the state can be adjusted by a chemical treatment, which is preferable. Here, as the chemical treatment, both surface treatment for removing impurities adhering to the surface and treatment for affecting the structure of clay can be used.

Specific examples include acid treatment, alkali treatment, salt treatment and the like. The acid treatment not only removes impurities on the surface but also increases the surface area by eluting cations such as Al, Fe and Mg in the crystal structure. Alkali treatment destroys the crystal structure of silicate, resulting in a structural change. Further, in the salt treatment and the organic substance treatment, an ionic complex, a molecular complex, an organic derivative and the like can be formed to change the surface area and the interlayer distance. By utilizing the ion exchange property and substituting the exchangeable ion between the layers with another large bulky ion, it is possible to obtain a layered material in which the layer is expanded. The acid used in the acid treatment is preferably hydrochloric acid, sulfuric acid,
It is selected from nitric acid, oxalic acid, phosphoric acid and acetic acid. Two or more kinds of salts and acids may be used for the treatment. When the salt treatment and the acid treatment are combined, there are a method of performing the salt treatment and then the acid treatment, a method of performing the acid treatment and then the salt treatment, and a method of simultaneously performing the salt treatment and the acid treatment.

The treatment conditions with salts and acids are not particularly limited, but usually the concentration of salts and acids is 0.1-0.1%.
Substances constituting at least one compound selected from the group consisting of ion-exchange layered silicates by selecting conditions of 80% by weight, treatment temperature from room temperature to boiling point, treatment time from 5 minutes to 24 hours. It is possible to produce a silicate suitable for the present invention by controlling the elution of the silicate. Further, salts and acids are generally used as an aqueous solution. As the treatment conditions, it is preferable to perform the acid treatment or the treatment in the coexistence of the acid and the salt at least once, and the acid concentration is 1 to 12 mol / liter, preferably 2 to 8 mol / liter. As described above, the desired silicate can be obtained by controlling the treatment temperature and the treatment time under the condition that the acid concentration is relatively high, which is a preferable method. For example, when using sulfuric acid, the concentration is preferably 18 to 58% by weight.

In the present invention, the acid treatment or the coexistence treatment of the acid and the salt is preferably carried out, but the shape may be controlled by pulverization or granulation before the treatment, during the treatment or after the treatment. Further, chemical treatment such as alkali treatment or organic treatment may be used together.
These silicates usually include adsorbed water and interlayer water. In the present invention, it is preferable to remove the adsorbed water and interlayer water before use. Here, the adsorbed water is water adsorbed on the surface of the silicate compound particles or on the crystal fracture surface, and the interlayer water is water existing between the layers of the crystals. In the present invention, these adsorbed water and / or interlayer water can be removed by heat treatment before use.

The method of heat-dehydrating silicate adsorbed water and interlayer water is not particularly limited, but methods such as heat dehydration, heat dehydration under gas flow, heat dehydration under reduced pressure, and azeotropic dehydration with an organic solvent are used. To be The temperature at the time of heating cannot be unconditionally specified depending on the type of silicate, but is 100 ° C. or higher, preferably 150 ° C. or higher so that interlayer water does not remain, but high temperature conditions that cause structural destruction ( Although it depends on the heating time, for example, 800 ° C. or higher) is not preferable. In the case of heat dehydration under gas flow, an inert gas is usually used, but heat treatment with air is also possible. Although the heating time is selected in relation to the heat treatment temperature of the silicate compound particles, it is generally 1 minute or longer, preferably 1 hour or longer. At that time, the water content of the silicate after the removal was 200
When the water content is 0% by weight when dehydrated for 2 hours at a temperature of 1 mmHg and a temperature of 3% by weight or less, preferably 1% by weight or less. As mentioned above,
In the present invention, a particularly preferable silicate is an ion-exchange layered silicate having a water content of 1% by weight or less, which is obtained by performing a salt treatment and / or an acid treatment.

Component [C] is an organoaluminum compound. The organoaluminum compound used as the component [C] in the present invention is suitably a compound represented by the general formula (AlR ⁴ _p X _3-p ) _q . In the present invention, it goes without saying that the compound represented by this formula can be used singly or as a mixture of two or more kinds or in combination. Further, this use is possible not only at the time of preparing the catalyst but also at the time of prepolymerization or polymerization. In this formula, R ⁴ represents a hydrocarbon group having 1 to 20 carbon atoms, and X represents a halogen, hydrogen, an alkoxy group or an amino group. p is an integer of 1 to 3 and q is an integer of 1 to 2. R ⁴ is preferably an alkyl group, and X is
Is preferably chlorine when it is a halogen, an alkoxy group having 1 to 8 carbon atoms when it is an alkoxy group, and an amino group having 1 to 8 carbon atoms when it is an amino group. Of these, trialkylaluminum and dialkylaluminum hydride with p = 3 and q = 1 are preferable.
More preferably, R ⁴ is trialkylaluminum having 1 to 8 carbon atoms.

The metallocene catalyst used in the present invention is preferably prepolymerized before the main polymerization.
Examples of the monomer used for the prepolymerization include ethylene, propylene, 1-butene, α-olefins such as 1-hexene, diene compounds such as 1,3-butadiene, styrene,
A vinyl compound such as divinylbenzene can be used. This prepolymerization is preferably carried out under a mild condition in an inert solvent, and is 0.01 to 10 per 1 g of the solid catalyst.
It is desirable to carry out so that 00 g, preferably 0.1 to 100 g of polymer is produced.

The polymerization reaction is carried out in the presence or absence of a solvent such as an inert hydrocarbon such as butane, pentane, hexane, heptane, toluene, cyclohexane or a liquefied α-olefin. The temperature is in the range of -50 to 250 ° C, and the pressure is not particularly limited. Further, hydrogen may be present as a molecular weight modifier in the polymerization system. Further, the polymerization temperature and the concentration of the molecular weight modifier may be changed to carry out the polymerization in multiple stages. After completion of the polymerization, the obtained propylene-based polymer,
Cleaning may be performed using an inert solvent or liquid α-olefin.

The propylene polymer of the present invention has 1 carbon atom.
The feature is that the content of the oligomer component of 2 to 30 is as low as 60 ppm or less. Another feature is that the content of volatile hydrocarbons is as low as 300 ppm. As a method for reducing such oligomer components and volatile hydrocarbons, (1) a polypropylene-based polymer (a), (b),
If necessary, the additive of (c) is added to reduce the oligomer content and the volatile hydrocarbon content in the post-treatment to a predetermined amount or less. (2) The oligomer content in the polypropylene polymer is post-treated. (A), (b)
A method of adding the additive of (c) as necessary, (3) after polymerizing so that the oligomer content of the polypropylene-based polymer is not more than a predetermined amount (a), (b), and if necessary. There is a method of adding the additive of (c). The present invention is
Either method may be used.

As a method for reducing the oligomer component and volatile hydrocarbons of the polypropylene resin, (1) the oligomer content is removed by slurry polymerization, and the drying is enhanced by a dryer to reduce the solvent and volatile hydrocarbons. Method (2) Method of shortening residence time of polymerization to suppress generation of oligomer component, and method of enhancing drying by dryer to reduce volatile hydrocarbons (3) Providing washing step with low boiling point solvent such as propylene A method of reducing volatile hydrocarbons by reducing the amount of oligomers and enhancing drying with a dryer can be used. In the washing step (3), after the polymerization using the metallocene catalyst is completed, the obtained propylene-based polymer is treated with an inert saturated hydrocarbon solvent such as propane, butane, pentane, hexane, heptane or a liquid α-olefin. And the like, and more preferably, using an inert hydrocarbon solvent having 3 or 4 carbon atoms or a liquid α-olefin. The washing method is not particularly limited, and known methods such as decantation of the supernatant after contact treatment in a stirring tank, countercurrent washing, and separation from a washing liquid by a cyclone can be used. A deactivator may be added before or at the same time as the washing. The deactivator is not particularly limited, and water, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone and methyl ethyl ketone, and the like, or a mixture thereof can be used. Further, as a method for enhancing the drying using the above resin powder, the drying treatment temperature is 60 to
The temperature is 100 ° C., the drying time is 1 to 4 hours, and the deodorizing treatment may be combined with a warm air drying treatment method for pellets.

Next, an example of a continuous process such as polymerization, washing and drying will be described with reference to the drawings. In the figure,
1 is a liquid phase polymerization tank, 2 is a cleaning tank, 3 is a slurry circulation pump, 4 is a liquid force classifier, 5 is a concentrator, 6 is a countercurrent pump, 7
Is a cleaning liquid receiving tank, 8, 10 and 14 are heat exchangers, 9 is a high-pressure degassing tank, 11, 15 and 21 are gas blowers, and 12
Is a low pressure degassing tank, 13 and 16 are cyclones, 17 and 20 are poppers, 18 is a screw feeder, and 19 is a dryer. A is a deactivator and B is a detergent. The propylene-based polymer polymerized in the liquid phase polymerization tank 1 is stirred in the cleaning tank 2. The deactivating agent A and the cleaning agent B are supplied to the cleaning tank 2. A part of the liquid portion of the slurry containing the deactivator and the cleaning agent is separated from the polymer by the liquid force classifier 4 and the concentrator 5, and extracted into the cleaning liquid receiving tank 7 to wash and remove oligomers and high boiling point components. It is removed outside the system. The washed propylene-based polymer is withdrawn as a slurry with a cleaning agent, concentrated in the liquid force classifier 4, and introduced into the cyclone 16 through the high pressure degassing tank 9 and the low pressure degassing tank 12. In the dryer 19, a volatile hydrocarbon reduction process is added in consideration of the application and specifications of the product.

<Additives> Various known additives can be used in the propylene-based random copolymer of the present invention, but in view of the "clean polypropylene" which is the subject of the present invention, the type and use of the additives. The amount should be as small as possible. However, in practical applications, various additives are used in order to prevent deterioration of polymer quality due to heat history. Therefore, in the present invention, both practical mechanical properties and quality can be satisfied by adding the necessary minimum amount of additives.

Additives preferably used in the present invention include the following. (A) Phenol-based antioxidant and / or hindered amine-based stabilizer (b) Neutralizer (c) Phosphorus-based antioxidant can be used in the propylene random copolymer of the present invention as described in (1) (a). ) Only, (2) add (a) and (b), (3) add (a) and (c) (4) add (a), (b) and (c) It can be mentioned.

When the polypropylene resin composition does not contain (a) a phenol-based antioxidant and / or a hindered amine-based stabilizer, burns are apt to occur during molding of the resin composition, which causes troubles, and its odor is various. It may be transferred to a molded container, which is a problem. If (b) the neutralizing agent is not contained, it may be affected by chlorine remaining as an impurity depending on the polymerization catalyst of propylene and the polymerization process. Further, the neutralizing agent also functions as a dispersant, and the neutralizing agent such as pigment may be used. Improves dispersibility. Furthermore, the phosphorus-based antioxidant is effective not only for preventing deterioration of the resin composition at the time of molding and processing, for suppressing burns and suppressing odor generation, but also for suppressing discoloration. That is, in the case of a container colored with a white pigment, the container may turn yellow due to aging or the like. On the other hand, the phosphorus-based antioxidant (c) is effective because it has an effect of suppressing discoloration. Instead of the phosphorus antioxidant, a lactone antioxidant and vitamin E can be used instead. Hereinafter, specific examples of each additive that can be used in the present invention and their preferable mixing ratios are shown.

(A-1) Phenolic Antioxidant Specific examples of the phenolic antioxidant which can be used in the present invention include tris- (3,5-di-t-butyl-).
4-hydroxybenzyl) -isocyanurate, 1,
1,3-tris (2-methyl-4-hydroxy-5-t
-Butylphenyl) butane, octadecyl-3- (3,3
5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 1,3,5-trimethyl-2,4
6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- [3- (3-
t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,
4,8,10 tetraoxaspiro [5,5] undecane, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid and the like can be mentioned. The amount of the phenolic antioxidant compounded is 0.01 per 100 parts by weight of the propylene polymer.
To 0.5 part by weight, preferably 0.02 to 0.3 part by weight. If it is less than this amount, the heat aging resistance of the product is not sufficient,
On the other hand, if it is excessive, not only is it uneconomical, but there is a problem of discoloration and bleeding, which is not preferable.

(A-2) Hindered amine light stabilizer As specific examples of the hindered amine light stabilizer that can be used in the present invention, dimethyl succinate and 1- (2
-Hydroxyethyl) -4-hydroxy-2,2,6,
Polycondensation product with 6-tetramethylpiperidine, poly [[6
-(1,1,3,3-tetramethylbutyl) amino-
1,3,5-triazine-2,4-diyl] [(2,
2,6,6-Tetramethyl-4-piperidyl) imino]
Hexamethylene [(2,2,6,6-tetramethyl-4
-Piperidyl) imino]], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid bis (1,2,2,6,6-pentamethyl-4-
Piperidyl) ester, tetrakis (2,2,6,6-
Tetramethyl-4-piperidyl) -1,2,3,4-butane tetracarboxylate, bis (2,2,6,6-
Tetramethyl-4-piperidyl) sebacate, N, N '
A polycondensate of -bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 1,2-dibromoethane, poly [(N, N'-bis (2,2,6,2
6-Tetramethyl-4-piperidyl) hexamethylenediamine)-(4-morpholino-1,3,5-triazine-2,6-diyl)], 1,1 ′-(1,2-ethanediyl) -bis ( 3,3,5,5-tetramethylpiperazinone), tris (2,2,6,6-tetramethyl-4-)
Piperidyl) -dodecyl-1,2,3,4-butanetetracarboxylate, tris (1,2,2,6,6-petanemethyl-4-piperidyl) -dodecyl-1,2,
3,4-butanetetracarboxylate, bis (1,
2,2,6,6-Petanemethyl-4-piperidyl) sebacate and the like can be mentioned.

These hindered amine antioxidants may be used alone or in combination of two or more kinds. Particularly, those having a molecular weight of 500 or more are preferable in terms of compatibility and excellent effect. Among these, the most suitable compound is poly [[6- (1-poly (1)-(2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine] , 1,3,3-Tetramethylbutyl) imino-1,3,5-triazine-2,4-
Diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-
Tetramethyl-4-piperidyl) imino]], poly [(N, N′-bis (2,2,6,6-tetramethyl-
4-Piperidyl) hexamethylenediamine)-(4-morpholino-1,3,5-triazine-2,6-diyl)] is preferred. The amount of the hindered amine component blended is 0.01 to 100 parts by weight of the propylene polymer.
0.4 parts by weight, preferably 0.02 to 0.3 parts by weight. If it is less than this amount, the heat aging resistance of the product is not sufficient. On the other hand, if it is excessive, not only is it uneconomical, but also discoloration and bleeding problems occur, which is not preferable.

(B) Neutralizing Agent The neutralizing agent that can be used in the present invention is a fatty acid metal salt,
Examples thereof include hydrotalcite and metal hydroxide salts, which may be used alone or in combination of two or more kinds. The content of the neutralizing agent is 0.0 per 100 parts by weight of the propylene polymer.
The amount is 1 to 0.2 part by weight, preferably 0.02 to 0.1 part by weight. If it is less than this amount, the effect of preventing corrosion of the mold, molding machine, etc. is not sufficient, while if it is excessive, not only is it uneconomical, but problems such as bleeding occur. Specific examples of the fatty acid metal salt, hydrotalcite and metal hydroxide salt are as follows.

(B-1) Fatty Acid Metal Salt The fatty acid metal salt that can be used in the present invention includes calcium stearate, magnesium stearate, zinc stearate, aluminum stearate, lithium stearate, sodium stearate and benzene. Calcium acid, magnesium behenate, zinc behenate, aluminum behenate, lithium behenate, similar metal laurate, metal montanate, metal melicinate, metal serotate, lignocerine Examples thereof include acid metal salts and hydroxystearic acid metal salts. Among these, metal soaps such as lithium stearate, magnesium stearate, zinc stearate, calcium stearate, aluminum stearate, magnesium behenate, zinc behenate, and calcium behenate are particularly preferred because of their performance and availability. preferable. These metal salts can be produced by a synthetic method in which a carboxylic acid compound and a metal hydroxide are reacted, followed by washing with water, dehydration, and drying (metathesis method), or a method of directly reacting without using water (direct method). it can.

(B-2) Hydrotalcites The hydrotalcites that can be used in the present invention do not contain a water-containing basic carbonate such as magnesium, calcium, zinc, aluminum or bismuth or crystal water. , Natural products and synthetic products. Examples of natural products include those having a structure of Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O. In addition, as a synthetic product, Mg _0.7 Al _0.3
(OH) ₂ (CO ₃ ) _0.15・ 0.54H ₂ O, Mg _4.5 Al
_{2 (OH) 1 3 CO 3} · 3.5H 2 O, Mg 4.2 Al 2 (O
_{H) 12.4 CO 3, Zn 6} Al 2 (OH) 16 CO 3 · 4H
₂ O, Ca ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O, Mg ₁₄ B
_{i 2 (OH) 2 9.6 ·} 4.2H 2 O , and the like.

(B-3) Metal Hydroxide Salt Examples of the metal hydroxide salt that can be used in the present invention include magnesium hydroxide, aluminum hydroxide and lithium aluminum complex hydroxide salt. (B-4) Other Neutralizing Agent Instead of the fatty acid metal salt, calcium stearoyl lactate, sodium stearoyl lactate, or magnesium stearoyl lactate can be used.

(C) Phosphorus-Based Antioxidant In the present invention, the phosphorus-based antioxidant that can be used, if necessary, is a phosphorus-based antioxidant generally used as an oxidation stabilizer for resin compositions, particularly Can be listed without limitation. Specifically, tris (mixed, mono and dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 4,4-butylidene bis (3-methyl-6-t-butyl) Phenyl-di-tridecyl) phosphate, 1,1,3-tris (2-methyl-4-di-tridecylphosphite-5)
-T-butylphenyl) butane, bis (2,4-di-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-butylphenyl)-
4,4'-biphenylene phosphonite pentaerythritol-di-phosphite, bis (2,6-di-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2'-ethylidenebis (4 6
-Di-t-butylphenyl) fluorophosphite,
Methylenebis (4,6-di-t-butylphenyl) -2
-Ethylhexyl-phosphite and the like can be mentioned. These may be used alone or in combination of two or more.

Among these, more preferred compounds include tris (2,4-di-t-butylphenyl) phosphite and tetrakis (2,4-di-butylphenyl).
-4,4'-Biphenylene phosphonite pentaerythritol-di-phosphite, bis (2,6-di-
Butyl-4-methylphenyl) pentaerythritol-
Di-phosphite, 2,2'-ethylidene bis (4,
6-di-t-butylphenyl) fluorophosphite and methylenebis (4,6-di-t-butylphenyl)
A compound of 2-ethylhexyl-phosphite is a preferred example. The amount of the phosphorus-based antioxidant compounded is 0.01 to 0.25 part by weight, preferably 0.02 to 0.2 part by weight, per 100 parts by weight of the propylene polymer. If it is less than this amount, the heat aging resistance of the product is not sufficient. On the other hand, if it is excessive, not only is it uneconomical, but also discoloration and bleeding problems occur, which is not preferable.

<Container> The injection-molded container of the present invention is obtained by injection-molding the polypropylene-based polymer described above or the propylene-based resin composition containing the various additives described above by a known method. . Examples of the use of the injection-molded container and the molded product include thin-walled food containers such as pudding, jelly, egg tofu, dairy products and fermented dairy products;
Tableware for microwave oven cooking; storage container for clothing, daily necessities, etc .; case of floppy (registered trademark), optical disk, video tape, 8 mm video, cassette tape, etc .; chemical solution for food, cosmetics, detergent, insecticide, etc. , Various sprays and other caps; stationery, accessory case, toys: syringe, plunger, needle base of injection needle, infusion / transfusion set, blood collection device, vial bottle, tablet bottle, blister packaging container, flfilled syringe, kit Medical supplies such as products, tubes, dialyzer, waste blood tanks; centrifuge tubes, culture tubes, syringe filters, petri dishes, beakers, flasks, test tubes and other science experiment tools, tissue culture instruments; potatoes
Fresh vegetables such as onions and garlic, dried vegetables, medicinal plants,
Meat such as refrigerated meat and frozen meat, processed fish products such as sausage and boiled shrimp, grains such as wheat and rice, seafood such as beans, fish, shellfish and frozen shrimp, fruits such as orange, mango, papaya and banana. Also included are food containers for storing fruits, eggs, and the like, and containers used for transportation as they are. Particularly, injection-molded products for which the required level of odor or the like is high or where the inclusion of impurities is disliked even a little.

The blow-molded container of the present invention can be obtained by blow-molding the polypropylene-based resin composition described above or the propylene-based resin composition containing the various additives described above. Molding can be carried out by a known method, for example, a direct blow method, an injection blow method, a hot stretch blow method, a cold stretch blow method or the like. As an application example of the blow-molded container, it is preferable to apply it to applications in which odor, taste, and contamination of impurities are disliked even a little, specifically, milk containers, fermented milk containers, lactic acid, etc. Beverage containers, containers for milk drinks and the like, and containers for similar products such as mineral water containers, tea containers, juice containers, cola containers, etc. as food containers, salad oil containers, ketchup containers, mayonnaise containers, lemon juice containers, etc. as food containers. Medical containers, such as sauce containers and soy sauce containers, include instillation solutions in the body, eyewash containers, medication containers, sterile purified water containers, etc., and other than these, cosmetic containers, semiconductor cleaning solution containers, etc. are basically odor and impurities. All containers are applicable for the purpose of preventing the contamination of

The thermoforming container of the present invention is obtained by molding the polypropylene-based polymer described above or the propylene-based resin composition containing the above-mentioned various additives into a sheet,
It is obtained by thermoforming a sheet into a container. Thermoforming can be performed by a known method. Here, thermoforming is a method of heating a sheet or the like to soften it and then forming it into a mold shape. As a molding method, vacuum or compressed air is used, and if necessary, a plug is also used to mold into a mold shape (straight method, drape method, air slip method, snapback method, plug assist method, etc.) and press. Examples of the method include molding. Various conditions such as the thermoforming temperature, the degree of vacuum, the pressure of the compressed air, the forming speed, and the like are appropriately set depending on the plug shape, the mold shape, the property of the raw material sheet, and the like. Examples of the shape of the molded container include various cups, trays, plates, bowls, bottles, cartons, and the like. As an application example of the present thermoforming container, a suitable target is an application in which an odorous component, a taste component, a low molecular weight component is not preferable because of migration to the content itself or the internal atmosphere and surface deterioration due to migration is not preferable. Various milk drinks and yogurt and pudding, margarine, fermented and processed milk products such as butter, containers and cups of jellies, potion containers such as milk portions, etc. Far
It is particularly suitable for food thermoforming containers represented by stoves and bento containers, meat, fish, trays such as side dishes, boiled snacks, snacks, etc., packs such as eggs and tofu, and tablets for non-food applications. PTP packaging and thermoforming containers for medicine such as inspection containers, thermoforming products for stationery and miscellaneous goods such as box files and cases, various blister packs for food and toys, H
Thermoforming products for physical distribution such as ACCP-related containers and cartons, and thermoforming products for interiors of refrigerators are also mentioned as applications where the influence of the above transition is not preferable.

[0045]

The following examples explain the present invention more specifically, but the present invention is not limited by these examples without departing from the gist thereof. The physical properties and the like in the following examples were measured by the following methods.

1. Xylene Soluble Content (CXS) First, the polymer was weighed by an electronic balance and put into a 500 ml flat bottom flask, and 300 ml of industrial xylene was added.
It was immersed in an oil bath whose temperature was adjusted to 140 ° C. in advance and dissolved for about 1 hour. Next, the flask was taken out and immersed in an oil bath preliminarily adjusted to 23 ° C. for 1 hour, then the supernatant was collected by filtration, and the solvent was removed / dried at 110 ° C. under reduced pressure for 4 hours to dissolve the xylene. Minutes (wt%) were determined.

2. The oligomer component having 12 to 30 carbon atoms (Wo) was measured by the following method based on the description in "Polymer Analysis Handbook" (Kinokuniya Bookstore, first edition 1995, first edition, p. 51, 183). 2.5 g of the polymer was freeze-pulverized, 100 ml of normal hexane was added, and the mixture was heated under reflux for 1 hour, cooled and filtered, then desolvated by a rotary evaporator to dryness, and then 4 ml of normal hexane again.
Was dissolved in water and extracted with ultrasonic waves, and then measured by gas chromatography / mass spectrometry (SIM) under the following conditions. Device; HP-GCD column; HP-1 0.23 mm × 30 m Temperature; 100 ° C. → 5 ° C./min→300° C. Injection amount; 1 μL Splitless detection; SIM (m / Z = 43,57 monitor m / Z =
43 (quantitative C18 conversion absolute calibration curve method, absolute calibration curve method based on JIS K 0123)

3. Bulk density Measured according to ASTM D1895-69. 4. Melt flow rate (MFR) JIS-K-6758 Polypropylene Test method (conditions:
It was measured at 230 ° C. and a load of 2.16 Kgf). 5. Melting point (Tm) Sample (about 5 mg) using a Seiko DSC measuring device
Melted at 200 ℃ for 5 minutes, then 40 ℃ up to 10 ℃ / m
After cooling down at a rate of in and crystallization, further 10 ° C /
The melting peak temperature and the melting end temperature when the temperature was raised to 200 ° C. for min and melting was evaluated.

6. 5 mg of volatile hydrocarbon polypropylene molded product cut into small pieces of several mm square
The sample was subjected to thermal decomposition under the following conditions and analyzed by gas chromatography. (I) Pyrolysis conditions Pyrolysis device; PYR-1A Pyrolysis temperature manufactured by Shimadzu Corporation; 210 ° C Pipe temperature; 100 ° C (ii) Conditional equipment for gas chromatograph; G-C14B column manufactured by Shimadzu Corporation; Chemicals Inspection Association G-100 (40 m, composition;
Methyl Silicone, polar; non-polar, film thickness;
1 μm) Column temperature; 60 ° C. → 150 ° C. Calibration curve; performed in terms of n-heptane.

7. Color (YI) Using a Toshiba injection molding machine IS90, a pellet-shaped sample was molded into a sheet-shaped test piece of 2 × 80 × 120 mm at a temperature of 230 ° C., a mold cooling water temperature of 40 ° C., and a molding cycle of 40 seconds. In accordance with JIS K7103, YI
Shown by value. 8. Formability The condition at the time of forming the sheet for measuring hue was observed.

9. Odor test method Clean, odorless wide-mouth glass bottle with stopper (300 mL)
Is prepared, and about 80 g of a sample obtained by cutting an injection-molded container into a shape of about 20 × 20 mm is put in a wide-mouthed bottle. The bottle is capped and placed in a gear oven made by Toyo Seiki heated to 80 ° C. for 2 hours to heat. It was taken out after heating and evaluated within 10 minutes according to the following odor criteria. Odor standard 0: Not felt 1st: Feeling 2nd: Feeling 3rd: Feeling comfortable 4th: Smell strongly

10. Taste test method 5 mL of injection-molded 600-mL container with a wall thickness of 1 mm was boiled with water.
After treating for more than a minute, 200 mL of coffee milk was placed in a container and the mouth was sealed with aluminum foil for cooking. Then 1
The one was stored in the refrigerator for 24 hours. The other is 2 at 80 ℃
After warming for 2 hours, allow to cool at room temperature for 1 hour and then in the refrigerator.
Stored for 4 hours. In addition, 200 mL of coffee milk was put in a clean 300 mL wide-mouth glass bottle with a stopper, which was used for comparison. After each treatment, a sensory test was performed by comparing with the target product of a glass bottle (wide-mouthed bottle). The criterion was expressed by the number of people who felt a difference compared to the glass bottle of coffee milk. (1/10 = 1 in 10)

[Example 1] (Preparation of catalyst) The following operation was carried out under deoxidation under an inert gas.
It was carried out using a dehydrated solvent and a monomer. The chemically treated montmorillonite was decompressed at 200 ° C.
The heat treatment was performed for 2 hours. Further, 200 g of the dried montmorillonite obtained above was introduced into a glass reactor equipped with a stirring blade having an internal volume of 3 L, and normal heptane and a heptane solution of triethylaluminum (10 mmo) were introduced.
1) was added, and the mixture was stirred at room temperature. After 1 hour, wash with normal heptane (residual liquid ratio is less than 1%) to make slurry 200
Prepared to 0 mL. Then, in advance, (r) -dimethylsilylenebis [2-methyl-4- (4-chlorophenyl) -4H-azurenyl] zirconium dichloride 3 m
870 mL of toluene slurry of mol and a solution of triisobutylaluminum (30 mmol) in heptane 42.6
The mixed liquid prepared by reacting mL at room temperature for 1 hour was added to the montmorillonite slurry and stirred for 1 hour. Then, 2.1 L of normal heptane was introduced into a stirring type autoclave having an internal volume of 10 L which was sufficiently replaced with nitrogen, and 40
Hold at ℃. Montmorillonite prepared earlier there /
The complex slurry was introduced. When the temperature became stable at 40 ° C, propylene was fed at a rate of 100 g / hour to maintain the temperature. After 4 hours, the propylene feed was stopped and maintained for another 2 hours. About 3 L of the supernatant was removed from the recovered prepolymerized catalyst slurry, and 170 mL of a heptane solution of triisobutylaluminum (30 mmol) was added,
After stirring for 10 minutes, heat treatment was performed at 40 ° C. under reduced pressure.
By this operation, polypropylene was 1.9 per 1 g of the catalyst.
A prepolymerized catalyst containing 2 g was obtained.

(Production of Propylene-Ethylene Random Copolymer) Liquid-phase polymerization tank having an inner volume of 270 L equipped with a stirrer, deactivation tank having an inner volume of 400 L, slurry circulation pump, circulation line hydraulic classifier, concentrator, countercurrent By a process that incorporates a deactivation cleaning system consisting of a pump and a cleaning liquid receiving tank, a high pressure degassing system consisting of a double-tube heat exchanger and a fluidized flash tank, and a post-treatment system including a low pressure degassing tank and a dryer, Continuous production of propylene / ethylene copolymer was carried out. The prepolymerized catalyst produced above was added to liquid paraffin (Tonen: White Rex 335) at a concentration of 2
Dispersed at 0% by weight, 0.56 g / h as a catalyst component
It was introduced into the liquid phase polymerization tank 1 at r. Furthermore, 40 kg / hr of liquid propylene and 1.2 kg / th of ethylene were added to this polymerization tank.
hr, hydrogen 0.06 g / hr, triisobutylaluminum 18 g / hr were continuously supplied, and the internal temperature was 62 ° C.
Polymerization was carried out by holding at

From the liquid-phase polymerization tank 1, a mixed slurry of the polymer and liquid propylene was used as a polymer at 12.0 kg / hr.
To remove it and add 2 parts of ethanol as a deactivator.
It was supplied at 1.0 g / hr. Liquid propylene 4
Supplying 0 kg / hr, heating the jacket to increase the internal temperature to 5
It was kept at 0 ° C. The polymer was extracted from the lower part of the classifier 4 into the high-pressure degassing tank 9, further passed through the low-pressure degassing tank 12, and dried in the dryer 19. The inside temperature of the dryer 19 was adjusted to 80 ° C. and the residence time was adjusted to 2 hours, and further dry nitrogen at room temperature was flowed in a countercurrent direction of the powder flow at a flow rate of 12 m ³ / hr. The dried polymer was taken out from the hopper 20. On the other hand, the liquid propylene separated from the polymer through the classifier 4 and the condenser 5 was withdrawn to the cleaning liquid receiving tank 7 at 40 kg / hr.

Ethylene content of the obtained powder = 3.3
wt%, MFR = 3.0, Tm = 124.1 ° C., CXS
= 0.3 wt%, bulk density = 0.49 g / cm ³ , volatile hydrocarbon amount of 6 to 10 carbon atoms 18 ppm, carbon number 12 to
The amount of 30 oligomer components was 1.9 ppm. For 100 parts by weight of the powder taken out, pentaerythyl-tetrakis [3-
(3,5-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals; hereinafter abbreviated as RA1010) 0.1 part by weight, as a phosphorus-based antioxidant, tris (2,4-di-). t-Butylphenyl) phosphite (manufactured by Ciba Specialty Chemicals; hereinafter abbreviated as RA168) 0.1 part by weight, and 0.05 part by weight of calcium stearate as a neutralizing agent are added, and after nitrogen sealing with a super mixer, 3 minutes. Mixed. Then, using a 30 mmD extruder, the hopper was granulated and pelletized at 230 ° C. while sealing the hopper with nitrogen. The MFR of the obtained pellets was 2.9, the amount of volatile hydrocarbons having 6 to 10 carbon atoms was 15 ppm, and the amount of oligomer components having 12 to 30 carbon atoms was 2.1 ppm, and there was no significant change before and after pelletization. Was shown. This pellet sample is supplied to a small direct blow molding machine JB105 blow molding machine manufactured by Japan Steel Works, Ltd., and direct blow molding is performed under the condition of a resin temperature of 220 ° C., capacity 500 mL, wall thickness 0.7 mm, weight 4
A 0 g container was molded. Table 1 shows the results of evaluation of the amount of volatile hydrocarbons in the blow-molded container, the odor, and the taste of the container when the coffee milk was stored and heated.

[Example 2] Polymerization was carried out under the same conditions as in Example 1 except that the catalyst feed rate to the liquid phase polymerization tank 1 was 0.65 g / hr and the hydrogen feed rate was 0.01 g / hr. . Ethylene content of the resulting polymer powder = 3.3 wt%, MFR = 0.8, Tm = 124.0
° C, CXS = 0.2 wt%, bulk density = 0.48 g / cm
³ , the amount of volatile hydrocarbons having 6 to 10 carbon atoms was 20 ppm, and the amount of oligomer components having 12 to 30 carbon atoms was 1.7 ppm. Pentaerythryl-tetrakis [3- (3,5
-T-Butyl-4-hydroxyphenyl) propionate] 0.1 part by weight, as a phosphorus-based antioxidant, tris (2,4-di-t-butylphenyl) phosphite 0.1 part by weight, as a neutralizing agent Then, 0.05 part by weight of calcium stearate was added, and after nitrogen-sealing with a super mixer, the mixture was mixed for 3 minutes. Then, granulate at 230 ° C while sealing the hopper with nitrogen using a 30mmD extruder.
Pelletized. This pellet sample is a multi-layer sheet manufactured by Pla Giken.
Using an extruder with a screw diameter of 65 mmφ, the cylinder temperature is 230 ° C and the T-die temperature is 230 ° C.
It is extruded into a sheet shape, sandwiched between two mirror-rolled rollers with 60 ° C. cooling water internally circulated, solidified by cooling, and wound up at a take-up speed of 2 m / min, and a sheet having a thickness of 1.5 mmt and a width of 460 mm. Got Further, the obtained sheet was preheated with a far-infrared heater (temperature setting: 350 ° C.) for 30 hours using an indirect heating type pressure molding machine (name: Cosmic molding machine) manufactured by Asano Laboratory. Second, compressed air pressure 2 kg / cm ² , cooling time 10 seconds, diameter 66φ, height 75 mm, taper-3 / 10
A 160 ml round cup container was molded. Molded container in constant temperature and humidity (temperature 23 ± 2 ° C, humidity 50 ± 5%)
Was adjusted for 24 hours, and a part thereof was cut out, and the amount of volatile hydrocarbons and odor thereof were measured, and the taste when the coffee milk was stored in this container and when heated was evaluated. The results are shown in Table 1. Table 2 shows the MFR and T of the propylene-based polymer.
The respective numerical values for m, CXS and Wo, and the sufficiency / non-satisfaction relations of the equations (1) and (2) are shown.

[Example 3] Polymerization was carried out under the same conditions as in Example 1 except that the catalyst feed rate to the liquid phase polymerization tank 1 was 0.37 g / hr and the hydrogen feed rate was 0.33 g / hr. . The resulting polymer powder had an ethylene content of 3.3 wt%, MFR of 28.6, and Tm of 125.
2 ° C., CXS = 0.8 wt%, bulk density = 0.48 g / c
m ³ , volatile hydrocarbon amount of 6 to 10 carbon atoms 21 ppm,
The amount of the oligomer component having 12 to 30 carbon atoms was 7.8 ppm. With respect to 100 parts by weight of the powder taken out, 0.1 parts by weight of pentaerythyl-tetrakis [3- (3,5-t-butyl-4-hydroxyphenyl) propionate] as a phenol-based antioxidant, phosphorus-based 0.1 parts by weight of tris (2,4-di-t-butylphenyl) phosphite as an antioxidant and 0.05 parts by weight of calcium stearate as a neutralizing agent were added, and nitrogen was supermixed in a super mixer for 3 minutes. Mixed. Then 30
Using a mmD extruder, the hopper was granulated and pelletized at 230 ° C while sealing the hopper with nitrogen. This pellet sample was supplied to a Toshiba injection molding machine IS90, and the capacity was 600 at a molding temperature of 230 ° C, a mold cooling water temperature of 40 ° C, and a molding cycle of 40 seconds.
A container having a volume of 1 mm and a wall thickness of 1 mm was formed. The injection-molded container is in a constant temperature and constant humidity state (temperature 23 ± 2 ° C, humidity 50 ± 5%)
Was adjusted for 24 hours, and a part thereof was cut out, and the amount of volatile hydrocarbons and odor thereof were measured, and the taste when the coffee milk was stored in this container and when heated was evaluated. The results are shown in Table 1.

Example 4 Polymerization was carried out under the same conditions as in Example 1, except that the catalyst feed rate to the liquid phase polymerization tank 1 was 0.24 g / hr and the hydrogen feed rate was 0.62 g / hr. . The polymer powder obtained as a result had an ethylene content of 3.3 wt%, an MFR of 78.6, and a Tm of 125.
5 ° C., CXS = 1.2 wt%, bulk density = 0.48 g / c
m ^3, volatile hydrocarbon content 23ppm of 6 to 10 carbon atoms,
The amount of the oligomer component having 12 to 30 carbon atoms was 10.8 ppm. The obtained powder was pelletized and injection-molded in the same manner as in Example 3. The injection-molded container was adjusted to a constant temperature and humidity (temperature 23 ± 2 ° C, humidity 50 ± 5%) for 24 hours, a part of it was cut out, the volatile hydrocarbon content and odor of this container were measured, and this container The taste of coffee using milk was evaluated when it was heated. The results are shown in Table 1.

Example 5 (Production of propylene homopolymer) In Example 1, the polymerization temperature was 70 ° C., the catalyst feed amount to the liquid phase polymerization tank 1 was 1.0 g / hr, and the ethylene feed was stopped. Polymerization was carried out under the same conditions except that the hydrogen feed rate was 0.08 g / hr. MFR of the resulting polymer powder =
35.7, Tm = 149.2 ° C., CXS = 0.2 wt
%, Bulk density = 0.48 g / cm ³ , the amount of volatile hydrocarbons having 6 to 10 carbon atoms was 18 ppm, and the amount of oligomer components having 12 to 30 carbon atoms was 6.7 ppm. The obtained powder was pelletized and injection-molded in the same manner as in Example 3. The injection-molded container was adjusted to a constant temperature and humidity (temperature 23 ± 2 ° C, humidity 50 ± 5%) for 24 hours, a part of it was cut out, the volatile hydrocarbon content and odor of this container were measured, and this container The taste of coffee using milk was evaluated when it was heated. The results are shown in Table 1.

Comparative Example 1 (Catalyst Preparation) Mg (OEt) ₂ : 3 was added to a 100 L reactor equipped with a stirring blade, a thermometer, a jacket, and a cooling coil.
0 mol was charged, and then Ti (OBu) ₄ was added to the Mg in the charged Mg (OEt) ₂ with respect to Ti.
It was charged so that (OBu) ₄ /Mg=0.60 (molar ratio). Further, 19.2 kg of toluene was charged and the temperature was raised with stirring. After reacting at 139 ° C. for 3 hours,
The temperature was lowered to 130 ° C., and a toluene solution of MeSi (OPh) ₃ was added to magnesium in Mg (OEt) ₂ charged in advance, and MeSi (OPh) ₃ /Mg=0.67.
(Molar ratio). The amount of toluene used here was 7.8 kg. After the addition is complete, 13
React at 0 ° C for 2 hours, then cool to room temperature and
(OEt) ₄ was added. The amount of Si (OEt) ₄ added is
Si (OEt) ₄ /Mg=0.056 (molar ratio) with respect to magnesium in Mg (OEt) ₂ charged in advance. Then, for the resulting reaction mixture,
Magnesium concentration is 0.57 (mol / L ・ TOL)
Toluene was added. In addition, diethyl phthalate (DEP) was added to Mg (OEt) ₂ previously charged.
DEP / Mg = 0.10 for magnesium in
(Molar ratio). The resulting mixture is
Then, the mixture was cooled to -10 ° C with stirring and TiCl ₄ was added dropwise over 2 hours to obtain a uniform solution. Note that TiCl
₄ was set so that TiCl ₄ /Mg=4.0 (molar ratio) with respect to magnesium in Mg (OEt) ₂ charged previously. After adding TiCl _4, add 0.5 while stirring.
The temperature was raised to 15 ° C at a rate of ° C / min, and the temperature was maintained for 1 hour.
Then, the temperature was again raised to 50 ° C. at 0.5 ° C./minute, and the temperature was maintained for 1 hour. Further, the temperature was raised to 118 ° C. at 1 ° C./min, and treatment was performed at the same temperature for 1 hour. After processing,
After stirring was stopped and the supernatant liquid was removed, the mixture was washed with toluene so that the residual liquid ratio was 1/73 to obtain a slurry.

Next, toluene and TiCl ₄ were added to the slurry obtained here at room temperature. Note that TiCl ₄
Was such that TiCl ₄ / Mg (OEt) ₂ = 5.0 (molar ratio) with respect to magnesium in Mg (OEt) ₂ charged previously. In addition, toluene is TiCl ₄
The concentration was adjusted to 2.0 (mol / L · TOL). While stirring this slurry, the temperature is raised to 118 ° C.
The reaction was carried out for 1 hour. After the reaction was completed, stirring was stopped, the supernatant was removed, and the residual liquid ratio was 1/150 with toluene.
To obtain a slurry of solid components. Further, 400 g of the solid component obtained above was transferred to another reactor having a stirring blade, a thermometer, and a cooling jacket, and normal hexane was added to obtain a solid component concentration of 5.0 (g / l). ). Trimethylvinylsilane, TEA and TBMDES were added at 15 ° C. with stirring to the obtained slurry. Where T
BMDES represents t-butylmethyldiethoxysilane, and t-butyl represents a tertiary butyl group. The amounts of TEA, trimethylvinylsilane, and TBMDES added were 3.1 (mmol), 0.2 (ml), and 0.2 with respect to 1 g of the solid component in the solid component.
(Ml). After completion of the addition, the mixture was continuously stirred and maintained at 15 ° C for 1 hour, further heated to 30 ° C, and stirred at the same temperature for 2 hours. Next, the temperature was lowered to 15 ° C. again, and while maintaining the same temperature, in the gas phase part of the reactor,
1.2 kg of propylene gas was fed at a constant rate for 72 minutes to carry out prepolymerization. After completion of the feeding, stirring was stopped, the supernatant was removed, and the mixture was washed with normal hexane to obtain a slurry of a prepolymerization catalyst component. The residual liquid ratio was 1/12. The resulting prepolymerized catalyst component had 3.1 g of propylene polymer per 1 g of the above solid component.

(Polymerization) Polymerization was carried out using the same reactor system used in Example 1. The prepolymerized catalyst component obtained above was dispersed in liquid paraffin (manufactured by Tonen: White Rex 335) at a concentration of 2% by weight, and introduced as a catalyst component at 0.25 g / hr. Liquid propylene 120 kg / hr, ethylene 1.8 kg /
Polymerization was carried out while continuously supplying hr and hydrogen at 20 g / hr and triethylaluminum at 16.3 g / hr, and maintaining the internal temperature at 70 ° C. 23.5 kg of a mixed slurry of polymer and liquid propylene as a polymer from the liquid phase polymerization tank 1
/ Hr and ethanol was supplied at a rate of 21.0 g / hr as a quenching agent. Liquid propylene was further supplied at 40 kg / hr, and the internal temperature was kept at 50 ° C. by heating with a jacket. The polymer was extracted from the lower part of the classifier 4 into the high-pressure degassing tank 9, further passed through the low-pressure degassing tank 12, and dried in the dryer 19. Inner temperature of the dryer 19 80
℃, so that the residence time is 2 hours, and dry nitrogen at room temperature in the countercurrent direction of the powder flow 12m ³ / h
The flow rate was r. The dried polymer is hopper 20
I took it out of. On the other hand, the liquid propylene separated from the polymer through the classifier 4 and the condenser 5 is 40 kg / hr.
It was extracted into the cleaning liquid receiving tank 7. Ethylene content of the obtained powder = 3.2 wt%, MFR = 1.8, Tm = 1
43.2 ° C., CXS = 6.5 wt%, bulk density = 0.48
g / cm ³ , volatile hydrocarbon amount of 6 to 10 carbon atoms 380
ppm, C12-C30 oligomer component amount 560p
It was pm. The obtained powder was pelletized and blow-molded in the same manner as in Example 1. Blow-molded container is in a constant temperature and humidity state (temperature 23 ± 2 ° C, humidity 50 ± 5%)
Was adjusted for 24 hours, and a part thereof was cut out, and the amount of volatile hydrocarbons and odor thereof were measured, and the taste when the coffee milk was stored in this container and when heated was evaluated. The results are shown in Table 1.

[Comparative Example 2] In Comparative Example 1, the catalyst feed amount to the liquid layer polymerization tank 1 was 0.3 g / hr, the ethylene feed amount was 1.8 kg / hr, and the hydrogen feed amount was 15 g.
Polymerization was carried out under the same conditions except that / hr was used. Ethylene content of the polymer powder obtained as a result = 3.1 wt%,
MFR = 0.8, Tm = 143.8 ° C., CXS = 5.5
wt%, bulk density = 0.48 g / cm ³ , carbon number 6-10
The amount of volatile hydrocarbons was 360 ppm, and the amount of oligomer components having 12 to 30 carbon atoms was 420 ppm. The obtained powder was pelletized and thermoformed in the same manner as in Example 2. The thermoformed container is kept in a constant temperature and constant humidity state (temperature 23 ± 2
Conditioned at ℃, humidity 50 ± 5%) for 24 hours, cut out a part of it, measure the amount of volatile hydrocarbons and odor, and evaluate the taste when coffee milk is stored in this container and when heated. did. The results are shown in Table 1.

[Comparative Example 3] In Comparative Example 1, the catalyst feed amount to the liquid layer polymerization tank 1 was 0.22 g / hr, the ethylene feed amount was 1.5 kg / hr, and the hydrogen feed amount was 33.
Polymerization was carried out under the same conditions except that g / hr was used. Ethylene content of the resulting polymer powder = 2.5 wt
%, MFR = 29, Tm = 149.0 ° C., CXS = 4.
8 wt%, bulk density = 0.47 g / cm ³ , carbon number 6 to 1
0 volatile hydrocarbon content 360 ppm, carbon number 12-30
The amount of the oligomer component of was 720 ppm. The obtained powder was pelletized and injection-molded in the same manner as in Example 3. The injection-molded container was kept at a constant temperature and humidity (temperature 23 ±
After adjusting for 24 hours at 2 ℃ and humidity 50 ± 5%), cut out a part of it, measure the amount of volatile hydrocarbons and odor, and taste the coffee milk stored in this container and when heated. evaluated. The results are shown in Table 1.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

EFFECT OF THE INVENTION Since the propylene-based polymer of the present invention and the composition thereof have a very low content of the oligomer component,
The molded product is suitable for molded containers having various structures, which are excellent in odor and taste, surface gloss, drop strength and handleability. It is particularly useful for dairy products such as milk, dairy drinks and yogurt. Smoke during processing, offensive odor, and blocking property due to stickiness after processing are also improved.

[Brief description of drawings]

FIG. 1 is an example of a continuous production process of a propylene-based polymer.

[Explanation of symbols]

1: Liquid phase polymerization tank 2: Cleaning tank 3: Slurry circulation pump 4: Liquid force classifier 5: Concentrator 6: Countercurrent pump 7: Cleaning liquid receiving tank 8, 10, 14: Heat exchanger 9: High pressure degassing tank 11, 15, 21: Gas blower 12: Low pressure degassing tank 13, 16: Cyclone 17, 20: Popper 18: Screw feeder 19: Dryer A: deactivator B: Cleaning agent

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08K 5/00 C08L 23/10 C08L 23/10 B65D 1/00 A (72) Inventor Takao Tayano Mie Prefecture 1 Toho-cho, Yokkaichi-shi Japan Polychem Co., Ltd. Catalyst Development Center (72) Inventor Yasunori Nakamura 1 Toho-cho, Yokkaichi-shi, Mie F-term in Material Development Center, Japan Polychem Co. 3E033 BA16 CA20 FA02 FA03 GA02 4F071 AA15X AA20 AA20X AA84 AA88 AC05 AC07 AC11 AC15 AC19 AE05 AE22 AF05 BB05 BB06 BC04 4J002 BB121 BB141 BB151 CM022 DE078 DE148 DE288 EG028 CAEG06 AE04 AO4 EU076A07A02 EU01 EU02 EU02 EU02 EU01 EU02 EU02 EU02

Claims (13)

[Claims] 1. A propylene-based polymer polymerized using a metallocene catalyst, wherein the content (Wo) of an oligomer component having 12 to 30 carbon atoms is 60 ppm or less. 2. The melting point (Tm) is in the range of 110 to 155 ° C., and the xylene-soluble component (CXS) (unit: wt%) at 23 ° C. and the melting point (Tm) satisfy the following formula (1). The propylene-based polymer according to claim 1, which is characterized in that. Formula (1) CXS ≦ −0.05 × Tm + 7.76 (where 125 ≦ Tm ≦ 155) CXS ≦ 0.0294 × (Tm) ² −7.51 × Tm +
480.9 (when 110 ≦ Tm <125) 3. A melt flow rate (MFR) of 0.1 to 10.
It is in the range of 100 g / 10 minutes, and the content (Wo) of the oligomer component having 12 to 30 carbon atoms and the MFR are represented by the following formula (2).
The propylene-based polymer according to claim 1 or 2, characterized in that: Formula (2) Wo ≦ 6 × exp (0.023 × MFR) 4. The propylene-based polymer according to claim 1, wherein the propylene-based polymer is a random copolymer of propylene and an α-olefin other than propylene having 2 to 20 carbon atoms. 5. The propylene-based polymer according to any one of claims 1 to 4, wherein the propylene-based polymer is obtained by polymerizing using a metallocene catalyst and then contact-treated with a hydrocarbon-based detergent. 6. The propylene-based polymer is obtained by polymerizing using a metallocene catalyst and then contact-treating with a hydrocarbon-based detergent and a deactivator selected from water, alcohols and ketones. ~ The propylene-based polymer according to any one of 4 to 4. 7. A propylene-based polymer polymerized by using a metallocene catalyst, wherein the content (Wo) of an oligomer component having 12 to 30 carbon atoms is 60 ppm or less, and (a) a phenol-based polymer. A propylene polymer composition comprising an antioxidant and / or a hindered amine stabilizer and (b) a neutralizing agent. 8. A propylene-based polymer polymerized by using a metallocene catalyst, wherein the content (Wo) of an oligomer component having 12 to 30 carbon atoms is 60 ppm or less, and (a) a phenol-based polymer. A propylene polymer composition comprising an antioxidant and / or a hindered amine stabilizer, (b) a neutralizing agent, and (c) a phosphorus antioxidant. 9. A container obtained by injection molding the propylene-based polymer or the propylene-based polymer composition according to any one of claims 1 to 8. 10. A container obtained by blow molding the propylene-based polymer or propylene-based polymer composition according to any one of claims 1 to 8. 11. A blow molding container for dairy products, which is obtained by blow molding the propylene-based polymer or propylene-based polymer composition according to claim 1. 12. A container obtained by thermoforming the propylene-based polymer or propylene-based polymer composition according to claim 1. 13. A container according to any one of claims 9 to 12, wherein the content of the volatile hydrocarbon having 6 to 10 carbon atoms is 300 ppm or less.