JP2021024641A - Drawn container - Google Patents

Abstract

To provide a drawn container that has superior drawing blow moldability, high container rigidity, and small container shrinkage after high-temperature sterilization processing.SOLUTION: A drawn container is formed of a propylene-based polymer composition (A) including: 0.5-45 mass% of a propylene-based polymer (a1) of 10-12 dl/g in intrinsic viscosity [η] measured in a tetralin solvent at 135°C and 55-99.5 mass% of a propylene-based polymer (a2) of 0.5-3.5 dl/g in intrinsic viscosity [η] measured in the tetralin solution at 135°C (where a total mount of the propylene copolymer (a1) and propylene copolymer (a2) is 100 mass%).SELECTED DRAWING: None

Description

The present invention relates to a stretched container.

Containers made of propylene-based polymers are lightweight, have excellent chemical resistance, and have excellent transparency, and are therefore widely used as containers for foods, toiletries, detergents, medical treatments, and the like. As a material for a conventional stretched blow container, a propylene homopolymer is exclusively used because the rigidity of the container is important. As a method for industrially producing a stretch blow container, generally, a propylene homopolymer is melt-injection molded, a preform is once molded, then vertically stretched with a stretching rod, and then transversely stretched with a pressurized fluid. The method is used.

Patent Document 1 contains an organic phosphate ester compound satisfying a specific requirement, an aliphatic carboxylic acid and a derivative thereof, a propylene / ethylene random copolymer satisfying a specific requirement, and a propylene-based polymer. A propylene-based resin composition for axial stretching and blow stretching is described.

Patent Document 2 describes a propylene-based resin composition having a crystal melting point of 140 to 155 ° C. as measured by a differential scanning calorimeter (DSC) and satisfying specific requirements, and a stretched container made of the same.

Japanese Unexamined Patent Publication No. 2017-14352 JP-A-2019-49001

The shrinkage rate of the container obtained by using the propylene homopolymer after the sterilization treatment is superior to that of the container obtained by using the propylene copolymer, but it is not sufficient. On the other hand, when a propylene / ethylene random copolymer or a resin composition having a low crystal melting point of the resin is used, the rigidity of the obtained container is lowered, and the container shrinkage after the high temperature sterilization treatment at 121 ° C. or higher is increased. Therefore, a container made of a propylene-based polymer that further increases the rigidity of the container and has a small container shrinkage after sterilization is desired. Further, it is desirable that the stretch blow moldability is excellent.

An object of the present invention is to provide a stretched container having excellent stretch blow moldability, high container rigidity, and small container shrinkage after high temperature sterilization treatment.

As a result of diligent studies, the present inventors have found that a stretched container made of the propylene-based polymer composition described below can solve the above-mentioned problems, and have completed the present invention.

[1] 0.5 to 45% by mass of the propylene-based polymer (a1) having an ultimate viscosity [η] in the range of 10 to 12 dl / g measured in a tetralin solvent at 135 ° C., and 135 ° C. in a tetralin solvent. The propylene-based polymer (a2) having the ultimate viscosity [η] measured in the range of 0.5 to 3.5 dl / g was added to 55-99.5% by mass [however, with the propylene-based polymer (a1). The total amount with the propylene-based polymer (a2) is 100% by mass. ] Containing propylene-based polymer composition (A).

[2] The melt flow rate (MFR) of the propylene-based polymer composition (A) measured at 230 ° C. and a load of 2.16 kg is in the range of 0.01 to 40 g / 10 minutes. The stretched container according to the description.

[3] The area of the high molecular weight region having a molecular weight of 1.5 million or more, which is occupied by the propylene polymer composition (A) in the total area surrounded by the molecular weight distribution curve measured by gel permeation chromatography (GPC). The stretched container according to the above [1] or [2], wherein the ratio is 1% or more.

[4] The unit area of the propylene-based polymer composition (A) is the number of FEs [the number of FEs measured using an FE counter for a film having a thickness of 50 μm formed by a 25 mmΦ T-die film forming machine. The stretched container according to any one of the above [1] to [3], wherein the value converted to the number of pieces per 3000 cm ^{2) is 100 or less.}

[5] The stretched container according to any one of the above [1] to [4], which is a medical container, a food container, a beverage container, a toiletry container, a detergent container or a cosmetic container.
[6] The stretched container according to any one of the above [1] to [5], which is an infusion container.

According to the present invention, it is possible to provide a stretched container having excellent stretch blow moldability, high container rigidity, and small container shrinkage after high temperature sterilization treatment.

The stretched container of the present invention comprises a specific propylene-based polymer composition (A). Hereinafter, the propylene-based polymer composition (A) and its stretched container will be described in detail.

[Propylene-based polymer composition (A)]
The propylene-based polymer composition (A) contains 0.5 to 45 mass of the propylene-based polymer (a1) having an ultimate viscosity [η] in the range of 10 to 12 dl / g measured in a tetralin solvent at 135 ° C. %, And the propylene-based polymer (a2) having an ultimate viscosity [η] in the range of 0.5 to 3.5 dl / g measured in a tetralin solvent at 135 ° C. was 55 to 99.5% by mass [however. The total amount of the propylene-based polymer (a1) and the propylene-based polymer (a2) is 100% by mass. ] Including.

The details of the measurement conditions for each requirement will be described in the column of Examples.
Hereinafter, the propylene-based polymer composition (A) is also simply referred to as "composition (A)". Further, the ultimate viscosity [η] measured in a tetralin solvent at 135 ° C. is also simply referred to as “extreme viscosity [η]”. The mass fractions of the propylene-based polymer (a1) and the propylene-based polymer (a2) are based on the total amount of (a1) and (a2).

<Propylene polymer (a1)>
The ultimate viscosity [η] of the propylene-based polymer (a1) is in the range of 10 to 12 dl / g, preferably in the range of 10.5 to 11.5 dl / g. The mass fraction of the propylene-based polymer (a1) is in the range of 0.5 to 45% by mass, preferably 1.0 to 40% by mass, more preferably 1.5 to 35% by mass, and even more preferably. Is in the range of 2.0 to 30% by mass.

Examples of the propylene-based polymer (a1) include a homopolymer of propylene and a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms (excluding propylene). Examples of the α-olefin having 2 to 8 carbon atoms include ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Ethylene is preferable as these α-olefins. One kind or two or more kinds of α-olefins can be used.

In the copolymer of propylene and α-olefin having 2 to 8 carbon atoms, the content ratio of the constituent unit derived from propylene is usually 90% by mass or more, preferably 95% by mass or more, and more preferably 98% by mass or more. The content of the structural unit derived from the α-olefin having 2 to 8 carbon atoms (excluding propylene) is usually 10% by mass or less, preferably 5% by mass or less, and more preferably 2% by mass or less. Is. The content ratio can be measured by ^{13 C-NMR.}

When the ultimate viscosity [η] of the propylene-based polymer (a1) exceeds 12 dl / g, the preform moldability tends to be inferior. Further, when the ultimate viscosity [η] of the propylene-based polymer (a1) is less than 10 dl / g, the melt tension of the obtained polymer composition is insufficient, and the preform is heated during stretching blow molding. Eccentricity and the like occur, and the shape tends to be easily deformed.

If the mass fraction of the propylene-based polymer (a1) is less than 0.5% by mass, the melt tension of the obtained polymer composition is insufficient, so that the eccentricity of the preform or the like during heating of the preform in stretch blow molding , And the shape tends to be easily deformed, and the shrinkage of the stretched container due to the high temperature sterilization treatment tends to increase. If it exceeds 45% by mass, it causes a poor appearance during preform molding. There is a tendency.
One kind or two or more kinds of propylene-based polymers (a1) can be used.

<Propylene polymer (a2)>
The ultimate viscosity [η] of the propylene-based polymer (a2) is in the range of 0.5 to 3.5 dl / g, preferably 0.6 to 3.0 dl / g, and more preferably 0.8 to 3. It is in the range of 0 dl / g. The mass fraction of the propylene-based polymer (a2) is in the range of 55 to 99.5% by mass, preferably 60 to 99% by mass, more preferably 65 to 98.5% by mass, and further preferably 70. It is in the range of ~ 98.0% by mass.

Examples of the propylene-based polymer (a2) include a homopolymer of propylene, a copolymer of propylene and α-olefin having 2 to 8 carbon atoms (excluding propylene), and a block-type propylene polymer (propylene). Examples thereof include a homopolymer or a mixture of a propylene / α-olefin random copolymer and an amorphous or low crystalline propylene / α-olefin random copolymer). Examples of the α-olefin having 2 to 8 carbon atoms include ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Ethylene is preferable as these α-olefins. One kind or two or more kinds of α-olefins can be used.

In the copolymer of propylene and α-olefin having 2 to 8 carbon atoms, the content ratio of the constituent unit derived from propylene is usually 90% by mass or more, preferably 93% by mass or more, and more preferably 94% by mass or more. The content of the structural unit derived from the α-olefin having 2 to 8 carbon atoms (excluding propylene) is usually 10% by mass or less, preferably 7% by mass or less, and more preferably 6% by mass or less. Is. The content ratio can be measured by ^{13 C-NMR.}

When the ultimate viscosity [η] of the propylene-based polymer (a2) is less than 0.5 dl / g, the melt tension of the obtained polymer composition tends to be insufficient, and the ultimate viscosity [η] is 3. If it exceeds 5 dl / g, the viscosity tends to be high and the preform formability tends to deteriorate.

If the mass fraction of the propylene-based polymer (a2) is less than 55% by mass, it tends to cause poor appearance during preform molding, and if it exceeds 99.5% by mass, the stretch blow moldability is poor and sterilization is performed. The shrinkage rate after treatment tends to increase.
One kind or two or more kinds of propylene-based polymers (a2) can be used.

The content of the structural unit derived from propylene in the entire composition (A) is usually 90 to 100% by mass, preferably 95 to 100% by mass, more preferably 98 to 100% by mass, and has 2 to 2 carbon atoms. The content of the structural unit derived from α-olefin (excluding propylene) of 8 is usually 0 to 10% by mass, preferably 0 to 5% by mass, and more preferably 0 to 2% by mass (however). , The total content of the structural unit derived from propylene and the structural unit derived from α-olefin having 2 to 8 carbon atoms is 100% by mass).

The total content of the propylene-based polymer (a1) and the propylene-based polymer (a2) in the entire composition (A) is usually 70% by mass or more, preferably 90% by mass or more, and more preferably 98% by mass. That is all.

<Additives>
The propylene-based polymer composition (A) can contain additives such as an antioxidant, a neutralizing agent, a flame retardant, and a crystal nucleating agent, if necessary. One kind or two or more kinds of additives can be used. The ratio of the additive is not particularly limited and can be adjusted as appropriate.

<Physical characteristics of propylene-based polymer composition (A)>
The composition (A) is excellent in stretch blow moldability. Further, by using the composition (A), it is possible to produce a stretched container having high rigidity and small container shrinkage after high temperature sterilization treatment.

The composition (A) has a melt flow rate (MFR) measured at 230 ° C. and a load of 2.16 kg, usually 0.01 to 40 g / 10 minutes, preferably 0.05 to 30 g / 10 minutes, more preferably. Is in the range of 0.1 to 20 g / 10 minutes. When the MFR of the composition (A) is in the above range, the preform moldability is excellent and the stretch blow moldability is excellent.

The composition (A) is the ratio of the area of the high molecular weight region having a molecular weight of 1.5 million or more to the total area of the region surrounded by the molecular weight distribution curve measured by gel permeation chromatography (GPC) (high molecular weight of 1.5 million or more). (Corresponding to the mass ratio of the molecular weight component) is preferably 1% or more, more preferably 1.5% or more, still more preferably 2% or more. The fact that the area ratio of the high molecular weight region occupies a specific ratio or more means that the propylene-based polymer composition contains a high molecular weight component having a molecular weight of 1.5 million or more. At least a part of this high molecular weight component is a high molecular weight component having an ultimate viscosity [η] of 10 to 12 dl / g. Therefore, if the proportion of the high molecular weight component is less than 1%, the stretch blow moldability is inferior and the shrinkage rate after the sterilization treatment may increase.

The upper limit of the area ratio of the high molecular weight region having a molecular weight of 1.5 million or more to the total area surrounded by the molecular weight distribution curve is usually 25%, preferably 20%, and more preferably 15%.

The composition (A) has an FE number of usually 100 or less, preferably 70 or less, and more preferably 50 or less. If the number of FEs exceeds 100, the appearance of the stretched container may be poor. By setting the number of FEs of the composition (A) within the above range, a stretched container having a good appearance can be obtained.

The number of FEs is measured as follows. From the propylene-based polymer composition, a film having a thickness of 50 μm formed by a 25 mmΦ T-die film forming machine is obtained. For the film, the number of FEs having a size of 100 μm or more is measured using a fisheye (FE) counter and converted into the number per ^{unit area (3000 cm 2).}

<Method for Producing Propylene Polymer Composition (A)>
Examples of the method for producing the propylene-based polymer composition (A) include various known production methods. For example, after producing the propylene-based polymer (a1) and the propylene-based polymer (a2) that satisfy the above physical properties, respectively. , A method (1) of mixing or melt-kneading a propylene-based polymer (a1) and a propylene-based polymer (a2) in the above range to obtain a propylene-based polymer composition (A); a propylene-based weight satisfying the above physical properties. Examples thereof include a method (2) of producing a coalescence (a1) and a propylene-based polymer (a2) with one polymerization system or two or more polymerization systems to obtain a propylene-based polymer composition (A).

In the method (1), for example, the propylene-based polymer (a1), the propylene-based polymer (a2) and, if necessary, additives and the like were mixed using a Henschel mixer, a V-type blender, a tumbler blender, a ribbon blender and the like. After that, by melt-kneading using a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer, or the like, a high-quality propylene-based polymer composition in which each of the above components is uniformly dispersed and mixed can be obtained. .. The resin temperature during melt-kneading is usually 180 to 280 ° C, preferably 200 to 260 ° C.

In the method (2), a propylene-based polymer composition containing a relatively high molecular weight propylene-based polymer (a1) and a relatively low molecular weight propylene-based polymer (a2) is obtained by multi-stage polymerization of two or more stages. Obtainable. Additives may be added to the obtained propylene-based polymer composition as needed, and the obtained propylene-based polymer composition and further propylene-based polymer (a1) and / or propylene-based The polymer (a2) may be mixed. The resin temperature at the time of melt-kneading when the polymer is mixed is usually 180 to 280 ° C, preferably 200 to 260 ° C.

As a preferable method for producing the composition (A), for example, in the presence of a catalyst for producing highly stereoregular polypropylene, propylene alone or in combination with propylene and another monomer is used for multi-stage polymerization of two or more stages. There is a method of polymerizing with.

Specifically, in the first-stage polymerization, propylene or propylene is polymerized with α-olefin having 2 to 8 carbon atoms in the absence of substantially hydrogen, and the ultimate viscosity [η] is 10. A propylene-based polymer (a1) having a relatively high molecular weight of ~ 12 dl / g, preferably 10.5-11.5 dl / g is produced, and a relatively low molecular weight propylene is produced in the second and subsequent stages of polymerization. The system polymer (a2) is produced.

The intrinsic viscosity [η] of the relatively low molecular weight propylene-based polymer (a2) produced in the second and subsequent stages of polymerization is 0.5 to 3.5 dl / g, preferably 0.6 to 3. It is 0.0 dl / g, more preferably 0.8 to 3.0 dl / g. The ultimate viscosity [η] is the ultimate viscosity [η] of the propylene-based polymer produced by the stage alone, and the ultimate viscosity [η] of the entire composition containing the propylene-based polymer up to the previous stage of the stage. ]is not it.

Further, in the polymerization of the second and subsequent stages, the MFR of the finally obtained composition (A) is usually 0.01 to 40 g / 10 minutes, preferably 0.05 to 30 g / 10 minutes, more preferably 0. . Adjust to 1 to 20 g / 10 minutes.

The method for adjusting the ultimate viscosity [η] of the propylene-based polymer produced in the second and subsequent stages is not particularly limited, but a method using hydrogen as the molecular weight adjusting agent is preferable.
The production order (polymerization order) of the propylene-based polymer (a1) and the propylene-based polymer (a2) is the first stage, which is a relatively high-molecular-weight propylene-based polymer in the absence of substantially hydrogen. After producing (a1), it is preferable to produce a propylene-based polymer (a2) having a relatively low molecular weight in the presence of hydrogen, for example, in the second and subsequent stages. Although the production order can be reversed, after the relatively low molecular weight propylene polymer (a2) is produced in the first stage, the relatively high molecular weight propylene polymer is produced in the second and subsequent stages. In order to produce (a1), it is necessary to remove the molecular weight modifier such as hydrogen contained in the reaction product of the first stage as much as possible before the start of the polymerization of the second and subsequent stages. The apparatus becomes complicated, and the ultimate viscosity [η] of the second and subsequent stages is difficult to increase.

The polymerization of each stage in the multi-stage polymerization can be carried out continuously or in a batch method, but it is preferably performed in a batch method. This is because when the propylene-based polymer composition is produced by the continuous multi-stage polymerization method, the composition unevenness between the polymerized particles may occur due to the residence time distribution, and the number of FEs may be further increased. By polymerizing in a batch system, a propylene-based polymer composition having a small number of FEs can be obtained.

In one embodiment, the composition (A) is also referred to as a polymer corresponding to the propylene-based polymer (a1) and a polymer corresponding to the propylene-based polymer (a2) (hereinafter, "propylene-based polymer (a2')"). The polymer mixture obtained by producing (referred to as) by multi-stage polymerization and the polymer corresponding to the propylene-based polymer (a2) (hereinafter, also referred to as “propylene-based polymer (a2”)) are mixed. Can be obtained. Here, the propylene-based polymer (a2 ") is preferably a polymer different from the propylene-based polymer (a2').

A propylene-based polymer composition having excellent preform moldability is obtained by further blending a propylene-based polymer (a2 ″) different from the propylene-based polymer (a2') into the polymer mixture obtained by multi-stage polymerization. It is possible to easily obtain a product and a stretched container having a small shrinkage rate after sterilization.

The propylene-based polymer (a2 ") is not particularly limited as long as the obtained composition can be stretched, and various known propylene-based polymers can be used. The propylene-based polymer (a2") is also a propylene-based polymer (a2 "). Since it corresponds to a2), the polymer exemplified as the propylene-based polymer (a2) can be mentioned. The structure of the propylene-based polymer (a2 ") is not particularly limited. For example, it is not a propylene homopolymer, a block-type propylene polymer (propylene homopolymer or a propylene / α-olefin random copolymer), and non-propylene polymer. (Mixed with crystalline or low crystalline propylene / α-olefin random copolymer), propylene / α-olefin random copolymer, random block polypropylene and the like.

Further, the propylene-based polymer (a2 ") may be a polymer obtained by melt-kneading the propylene-based polymer in the presence of an organic peroxide.
The melt flow rate (MFR) of the propylene-based polymer (a2 ") measured at 230 ° C. and a load of 2.16 kg is preferably 0.1 to 50 g / 10 minutes, more preferably 0.4 to 40 g / 10. Minutes, more preferably in the range of 0.5-30 g / 10 minutes.

The composition (A) is prepared by mixing a polymer mixture obtained by producing a propylene-based polymer (a1) and a propylene-based polymer (a2') by multi-stage polymerization with a propylene-based polymer (a2 "). When obtained, each of the above components can be in a desired blending amount depending on the use of the obtained stretched container. In one embodiment, the content ratio of the propylene-based polymer (a2 ") is preferably 2 to 95 mass. %, More preferably 5 to 90% by mass [however, the total amount of (a1), (a2') and (a2 ") is 100% by mass].

≪Manufacturing conditions≫
In the production of the propylene-based polymer (a1) and the propylene-based polymer (a2), homopolymerization of propylene or polymerization of propylene and α-olefin having 2 to 8 carbon atoms is known as slurry polymerization, bulk polymerization and the like. Can be done in a way. Further, it is preferable to use a polypropylene production catalyst described later.

As the production conditions of the propylene-based polymer (a1), in the absence of hydrogen, the raw material monomer is used as a polymerization temperature, preferably 20 to 80 ° C., more preferably 40 to 70 ° C., and a polymerization pressure of generally normal pressure. It is preferably produced by bulk polymerization under the conditions of ~ 9.8 MPa, preferably 0.2 to 4.9 MPa.

As the production conditions of the propylene-based polymer (a2), the raw material monomer has a polymerization temperature of preferably 20 to 80 ° C., more preferably 40 to 70 ° C., and a polymerization pressure of generally normal pressure to 9.8 MPa, preferably 9.8 MPa. It is preferably produced by polymerization under the conditions of 0.2 to 4.9 MPa and the presence of hydrogen as a molecular weight modifier.

≪Catalyst for polypropylene production≫
The polypropylene production catalyst (hereinafter, also simply referred to as “catalyst”) that can be used in the production of the propylene-based polymer (a1), the propylene-based polymer (a2), and the composition (A) is, for example, magnesium. It can be formed from a solid catalyst component containing titanium and halogen as essential components, an organic metal compound catalyst component such as an organic aluminum compound, and an electron donating compound catalyst component such as an organic silicon compound. , The following catalyst components can be used.

(Solid catalyst component)
As the carrier constituting the solid catalyst component, a carrier obtained from metallic magnesium, alcohol, halogen and / or halogen-containing compound is preferable.

As the metallic magnesium, magnesium in the form of granules, ribbon, powder or the like can be used. Further, the metallic magnesium preferably has no coating such as magnesium oxide on the surface.

As the alcohol, it is preferable to use a lower alcohol having 1 to 6 carbon atoms, and in particular, when ethanol is used, a carrier that significantly improves the development of catalytic performance can be obtained. The amount of alcohol used is preferably 2 to 100 mol, more preferably 5 to 50 mol, based on 1 mol of metallic magnesium. One or more alcohols can be used.

As the halogen, chlorine, bromine and iodine are preferable, and iodine is preferable. Further, as the halogen-containing compound, MgCl ₂ and MgI ₂ are preferable. The amount of the halogen or the halogen-containing compound used is such that the halogen atom or the halogen atom in the halogen-containing compound is usually 0.0001 gram atom or more, preferably 0.0005 gram atom or more, with respect to 1 gram atom of the metal magnesium. Preferably, it is 0.001 gram atom or more. Halogen and halogen-containing compounds can be used alone or in combination of two or more.

As a method for obtaining a carrier by reacting metallic magnesium, alcohol, and a halogen and / or a halogen-containing compound, for example, metallic magnesium, alcohol, and a halogen and / or halogen-containing compound are refluxed (eg, about). A method of reacting at 79 ° C.) until no hydrogen gas generation is observed (usually 20 to 30 hours) can be mentioned. The reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

When the obtained carrier is used for the synthesis of the solid catalyst component, a dried one may be used, or a carrier washed with an inert solvent such as heptane after filtration may be used.
The obtained carrier is close to granular and has a sharp particle size distribution. Furthermore, even if each particle is taken, the variation in grain shape is very small. In this case, the sphericality (S) represented by the following formula (I) is less than 1.60, particularly less than 1.40, and the particle size distribution index (P) represented by the following formula (II). Is preferably less than 5.0, particularly less than 4.0.

S = (E1 / E2) ² ... (I)
In formula (I), E1 indicates the contour length of the projection of the particle, and E2 indicates the perimeter of the circle equal to the projected area of the particle.

P = D90 / D10 ... (II)
In formula (II), D90 refers to a particle size corresponding to a cumulative mass fraction of 90%. That is, it is shown that the mass sum of the particles smaller than the particle diameter represented by D90 is 90% of the total mass mass of all particles. D10 refers to the particle size corresponding to the cumulative mass fraction of 10%.

The solid catalyst component is usually obtained by contacting the carrier with at least a titanium compound. The contact with the titanium compound may be divided into a plurality of times. Examples of the titanium compound include a titanium compound represented by the general formula (III).

TiX ¹ _n (OR ¹ ) _4-n ... (III)
In the formula (III), X ¹ is a halogen atom, particularly preferably a chlorine atom, R ¹ is a hydrocarbon group having 1 to 10 carbon atoms, a linear or branched alkyl group is preferable, and R ¹ is plural. If present, they may be the same or different from each other, where n is an integer from 0 to 4.

Specific examples of the titanium compound include Ti (O-i-C ₃ H ₇ ) ₄ , Ti (O-C ₄ H ₉ ) ₄ , TiCl (OC ₂ H ₅ ) ₃ , and TiCl (O-i). -C ₃ H ₇ ) ₃ , TiCl (O-C ₄ H ₉ ) ₃ , TiCl ₂ (O-C ₄ H ₉ ) ₂ , TiCl ₂ (O-i-C ₃ H ₇ ) ₂ , TiCl ₄ , TiCl ₄ is preferred.
One kind or two or more kinds of titanium compounds can be used.

The solid catalyst component is usually obtained by further contacting the carrier with an electron donating compound. Examples of the electron donating compound include di-n-butyl phthalate. One kind or two or more kinds of electron donating compounds can be used.

When the titanium compound and the electron-donating compound are brought into contact with the carrier, a halogen-containing silicon compound such as silicon tetrachloride can be brought into contact with the carrier. One or more halogen-containing silicon compounds can be used.

The solid catalyst component can be prepared by a known method. For example, a method in which an inert hydrocarbon such as pentane, hexane, peptane or octane is used as a solvent, the above carrier, electron donating compound and halogen-containing silicon compound are charged into the solvent, and the titanium compound is charged while stirring. Can be mentioned. Usually, 0.01 to 10 mol, preferably 0.05 to 5 mol, of the electron donating compound is added to 1 mol of the carrier in terms of magnesium atom, and titanium is added to 1 mol of the carrier in terms of magnesium atom. 1 to 50 mol, preferably 2 to 20 mol, of the compound is added, and the contact reaction is carried out at 0 to 200 ° C. for 5 minutes to 10 hours, preferably 30 to 150 ° C. for 30 minutes to 5 hours. You just have to do. After completion of the reaction, it is preferable to wash the produced solid catalyst component with an inert hydrocarbon such as n-hexane or n-heptane.

Further, the solid catalyst component may be a component obtained by contacting a liquid magnesium compound and a liquid titanium compound in the presence of an electron donating compound. The contact with the liquid titanium compound may be performed in a plurality of times.

The liquid magnesium compound can be obtained, for example, by bringing a known magnesium compound and alcohol into contact with each other, preferably in the presence of a liquid hydrocarbon medium, to make the liquid liquid. Examples of the magnesium compound include magnesium halides such as magnesium chloride and magnesium bromide. Examples of the alcohol include aliphatic alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and 2-ethylhexyl alcohol. Examples of the liquid hydrocarbon medium include hydrocarbon compounds such as heptane, octane, and decane. The amount of alcohol used in preparing the liquid magnesium compound is usually 1.0 to 25 mol, preferably 1.5 to 10 mol, based on 1 mol of the magnesium compound. One kind or two or more kinds of liquid magnesium compounds can be used.

Examples of the liquid titanium compound include the titanium compound represented by the above-mentioned general formula (III). The amount of the liquid titanium compound used with respect to 1 mol of magnesium atom (Mg) contained in the liquid magnesium compound is usually 0.1 to 1000 mol, preferably 1 to 200 mol. One kind or two or more kinds of liquid titanium compounds can be used.

Examples of the electron donating compound include dicarboxylic acid ester compounds such as phthalates, acid anhydrides such as phthalic anhydride, organic silicon compounds such as dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, and cyclohexylmethyldimethoxysilane, and polyethers. , Acid halides, acid amides, nitriles, organic acid esters. The amount of the electron donating compound used with respect to 1 mol of magnesium atom (Mg) contained in the liquid magnesium compound is usually 0.01 to 5 mol, preferably 0.1 to 1 mol. One kind or two or more kinds of electron donating compounds can be used.
The temperature at the time of contact is usually −70 to 200 ° C., preferably 10 to 150 ° C.

(Organometallic compound catalyst component)
Among the catalyst components, the organometallic compound is preferable as the catalyst component. Examples of the organoaluminum compound include compounds represented by the general formula (IV).

AlR ² _n X ² _3-n・ ・ ・ (IV)
In formula (IV), R ² is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group or an aryl group, X ² is a halogen atom or an alkoxy group, preferably a chlorine atom or a bromine atom, and n is 1 to 1. It is an integer of 3.

Specific examples of the organoaluminum compound include trialkylaluminum compounds such as trimethylaluminum, triethylaluminum and triisobutylaluminum, diethylaluminum monochloroide, diisobutylaluminum monochloroide, diethylaluminum monoethoxydo and ethylaluminum sesquichloride. ..

One kind or two or more kinds of organoaluminum compounds can be used.
The amount of the organometallic compound catalyst component used is usually 0.01 to 20 mol, preferably 0.05 to 10 mol, based on 1 mol of titanium atoms in the solid catalyst component.

(Electron-donating compound catalyst component)
Among the catalyst components, an organosilicon compound is preferable as the electron-donating compound component to be used in the polymerization system. Examples of the organosilicon compound include dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, diethylaminotriethoxysilane, diisopropyldimethoxysilane, and cyclohexylisobutyldimethoxysilane.

One kind or two or more kinds of organosilicon compounds can be used.
The amount of the electron-donating compound component used is usually 0.01 to 20 mol, preferably 0.1 to 5 mol, with respect to 1 mol of titanium atoms in the solid catalyst component.

(Preprocessing)
It is preferable that the solid catalyst component is used for polymerization after being pretreated by prepolymerization or the like. For example, an inert hydrocarbon such as pentane, hexane, peptane, or octane is used as a solvent, and the above-mentioned solid catalyst component, organic metal compound catalyst component, and, if necessary, an electron donating compound component are added to the solvent. While stirring, propylene is supplied and reacted. Propylene is preferably supplied under a partial pressure of propylene higher than atmospheric pressure and pretreated at 0 to 100 ° C. for 0.1 to 24 hours. After completion of the reaction, it is preferable to wash the pretreated product with an inert hydrocarbon such as n-hexane or n-heptane.

[Stretched container made of propylene-based polymer composition (A)]
The stretched container of the present invention can be obtained, for example, by stretching and blow molding the above-mentioned propylene-based polymer composition (A). Specifically, the composition (A) is melted and the composition (A) is injection-molded in a mold to form a preform, and then the preform is heated as necessary and then stretched. By doing so, the stretched container of the present invention can be obtained. As an example of stretching, the preform is forcibly stretched in the vertical direction using a stretching rod, and the preform is stretched in the horizontal direction by introducing a heated gas into the preform.

The melting and injection temperature of the composition (A) is usually in the range of 180 to 280 ° C. For preforms, the preheating temperature (preform surface temperature) is usually 90 to 160 ° C, the longitudinal stretching temperature is 20 to 160 ° C, and the longitudinal stretching ratio is 1.2 to 4.0 times, which is usually performed horizontally. The stretching temperature is 20 to 160 ° C., and the transverse stretching ratio is 1.2 to 4.0 times. The stretching may be performed vertically and horizontally separately, or may be stretched at the same time.

The stretched container of the present invention has both good rigidity and small container shrinkage after high temperature sterilization treatment at 121 ° C. or higher.
The stretched container of the present invention can be used for medical containers, food containers, beverage containers, toiletry containers, detergent containers, cosmetic containers in general, and for example, infusion containers for blood, Ringer's solution, purified water, etc. (particularly, infusion containers for intravenous injection). ), Medication containers for liquid cold medicine, eye medicine containers, eye wash containers, nutritional supplement containers, liquid food containers, diagnostic medicine containers, and other medical containers; drinking water, soft drinking water, sports drinks, and other drinking containers; soy sauce container, Examples include food containers such as sauce containers and salad oil containers. The stretched container of the present invention can be used not only for liquids but also for containers for containing solids such as tablets and powders. Among these, the stretched container of the present invention is effective in applications with high performance requirements for rigidity.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. The measurements and evaluations of various characteristics of the polymers and molded products obtained in each example were carried out as follows.

(1) In Production Example 1, the propylene-based polymer (corresponding to the propylene-based polymer (a1)) obtained in the first step and the propylene-based polymer (propylene-based polymer (propylene-based polymer) obtained in the second step). The mass fraction of) (corresponding to a2) was determined from the amount of slow heat of the reaction heat generated during polymerization.

(2) The ultimate viscosity [η] (dl / g) was measured at 135 ° C. in a tetralin solvent. _{In Production Example 1, the ultimate viscosity [η] 2} of the propylene-based polymer (corresponding to the propylene-based polymer (a2)) obtained in the second stage is a value calculated from the following formula.
[Η] ₂ = ([η] _total × 100− [η] ₁ × W ₁ ) / W ₂
[Η] _total : Extreme viscosity of the entire propylene-based polymer [η] ₁ : Extreme viscosity of _{the propylene-based polymer obtained in the first stage W 1} : Mass of the propylene-based polymer obtained in the first stage Fraction (%)
W ₂ : Mass fraction (%) of the propylene-based polymer obtained in the second stage

(3) The melt flow rate (MFR) (g / 10 minutes) was measured at a measurement temperature of 230 ° C. and a load of 2.16 kgf (21.2 N) in accordance with JIS-K7210.

(4) The area ratio of the high molecular weight region having a molecular weight of 1.5 million or more is a molecular weight distribution curve (specifically, the molecular weight distribution curve and the horizontal axis) measured by gel permeation chromatography (GPC) under the following equipment and conditions. It is the area ratio of the high molecular weight region having a molecular weight of 1.5 million or more to the total area of the region surrounded by. Here, the horizontal axis is molecular weight (logarithmic value), and the vertical axis is dw / dLog (M) [w: integrated mass fraction, M: molecular weight].
GPC measuring device Gel permeation chromatography HLC-8321 GPC / HT type (manufactured by Tosoh Corporation)
Analyst data processing software Empower 3 (manufactured by Waters)
Measurement conditions Column: TSKgel GMH6-HT × 2 + TSKgel GMH6-HT L × 2
(Both 7.5mm I.D.x30cm, manufactured by Tosoh)
Column temperature: 140 ° C
Mobile phase: o-dichlorobenzene (containing 0.025% BHT)
Detector: Differential refractometer Flow rate: 1.0 mL / min
Sample concentration: 0.1% (w / v)
Injection volume: 0.4 mL
Sampling time interval: 1s
Column calibration: Monodisperse polystyrene (manufactured by Tosoh)
Molecular weight conversion: PP conversion / general-purpose calibration method (PS (polystyrene) viscosity conversion coefficient K _PS = 0.000138dl / g,
α _PS = 0.700, PP (polypropylene) viscosity conversion coefficient K _PP = 0.000242dl / g, α _PP = 0.707)

(5) Ethylene content (mass%)
To measure the content of structural units derived from ethylene (ethylene content), 20-30 mg of sample was dissolved in 0.6 mL of a 1,2,4-trichlorobenzene / dibenzene (2: 1) solution to obtain Carbon-nuclear magnetic resonance analysis ( ¹³ C-NMR) was performed using the resulting solution. The quantification of propylene, ethylene and α-olefin was determined from the diad chain distribution. For example, in the case of a propylene / ethylene copolymer, PP = Sαα, EP = Sαγ + Sαβ, EE = 1/2 (Sβδ + Sδδ) + 1/4 Sγδ, and the following formulas (Eq-1) and (Eq-2) are used. It was. The unit of the ethylene content ratio in this example is expressed in terms of mass%.

Content ratio of constituent units derived from propylene (mol%) = (PP + 1 / 2EP) x 100 / [(PP + 1 / 2EP) + (1 / 2EP + EE)] ... (Eq-1)
Content ratio of structural units derived from ethylene (mol%) = (1 / 2EP + EE) x 100 / [(PP + 1 / 2EP) + (1 / 2EP + EE)] ... (Eq-2)
The Sαα and the like have peak intensities, and J.I. C. It is a value analyzed according to the method described in Randall (Review Macrodynamic Chemistry Physics, C29, 201 (1989)).

(6) Number of FEs The number of FEs of a film with a thickness of 50 μm produced by a 25 mmΦ T-die film forming machine manufactured by Plastic Engineering Laboratory Co., Ltd. is used as a gel counter, and a fish eye counter (trademark) manufactured by Hutec Co., Ltd. Was measured using. Here, an FE having a size of 100 μm or more was measured. The number of measurements was shown as the number of FEs per film unit area (3000 cm ^2).

The film production conditions are as follows.
T-die film forming machine: Plastic Engineering Laboratory Co., Ltd. Model: GT-25-A
Screw diameter: 25 mm, L / D = 24
Screw rotation speed: 60 rpm
Cylinder temperature setting: C1 = 230 ° C, C2 = 260 ° C
Head temperature setting: 260 ° C
T-die temperature setting: D1-D3 = 260 ° C
T-die width: 230 mm, lip opening = 1 mm
Film winding speed: 4 m / s
Roll temperature: 65 ° C
The measurement conditions of the gel counter are as follows.
Device configuration-Receiver (4096 pixels)
・ Floodlight ・ Signal processing device ・ Pulse generator ・ Cable between devices

(7) The tensile elastic modulus (MPa) was measured by molding a test piece by an injection molding method according to the method of JIS K7161. When the test piece formed from the composition has a high tensile elastic modulus, a container having high rigidity can be obtained from the composition.

(8) Evaluation of blow moldability (8-1) Preform molding A preform was molded by an injection molding machine. Specifically, using an EC-160N-6A type injection molding machine manufactured by Toshiba Machine Co., Ltd., the outer diameter is 27 mm and the height is 96 mm under the conditions of an injection resin temperature of 230 ° C., an injection pressure of 100 MPa, and a mold cooling temperature of 20 ° C. A test tube-shaped bottomed parison (preform) having a maximum wall thickness of 4.7 mm and a weight of 23 g was injection-molded.

(8-2) Blow Molding by Biaxial Stretch Blow Molding Machine The preform obtained above was molded by a cold parison method biaxial stretch blow molding machine. Specifically, using an ETEC biaxial stretching blow molding machine and an EFB1000 type biaxial stretching blow molding machine, the preform is heated with an infrared lamp while rotating, and the longitudinal stretching ratio is 2.3 times and the transverse stretching ratio is 2.3 times. A 500 mL flat container (molded article) that is 2.3 to 3.1 times larger is placed at an air pressure of 0.9 MPa for the primary pressure and 1.5 MPa for the secondary pressure as the rod for longitudinal stretching rises. Axial stretch blow molding was performed.

(8-3) Stretch blow moldability The neck, body, and bottom of the molded product were confirmed, and the presence or absence of uneven thickness and deformation of the molded product was confirmed.
◯: There is little uneven thickness of the molded product, and no deformation is confirmed.
X: The uneven thickness of the molded product is large, or deformation is confirmed.

(9) Shrinkage rate after sterilization at 121 ° C. The stretched container obtained in (8-2) above was adjusted to a standard state (25 ° C., 1 atm) for 48 hours. For the three bottles after adjusting the state, water was poured to fill the mouth of the stretching container and the weight of the water was measured. Let the weight of water at this time be (W1).

After immersing the above-mentioned stretched container in a tray in a flooded state, it was sterilized at a sterilization temperature of 121 ° C. for 15 minutes using a hot water spray sterilizer manufactured by Nisaka Seisakusho Co., Ltd., and then cooled to room temperature.

Next, the stretched container was dried, and using a stretched container that had been allowed to cool to room temperature (25 ° C.), water was poured to fill the mouth of the stretched container and the weight of the water was measured. The weight of water at this time is (W2). The value obtained by dividing ((W1)-(W2)) by (W1) and converting it to% was defined as the shrinkage rate after the sterilization treatment.

[Manufacturing Example 1]
(1) Preparation of magnesium compound A reaction vessel with a stirrer (internal volume 500 liters) was sufficiently replaced with nitrogen gas, 97.2 kg of ethanol, 640 g of iodine, and 6.4 kg of metallic magnesium were added, and reflux conditions were performed while stirring. The reaction was carried out in the system until no hydrogen gas was generated, and a solid reaction product was obtained. The reaction solution containing this solid reaction product was dried under reduced pressure to obtain the desired magnesium compound (carrier of solid catalyst component).

(2) Preparation of solid titanium catalyst component In a reaction vessel with a stirrer (internal volume 500 liters) sufficiently replaced with nitrogen gas, 30 kg of the magnesium compound (not crushed) and 150 purified heptane (n-heptane) Liter, 4.5 liters of silicon tetrachloride, and 5.4 liters of di-n-butyl phthalate were added. The inside of the system was kept at 90 ° C., 144 liters of titanium tetrachloride was added while stirring, and the mixture was reacted at 110 ° C. for 2 hours, and then the solid components were separated and washed with purified heptane at 80 ° C. Further, 228 liters of titanium tetrachloride was added and reacted at 110 ° C. for 2 hours, and then thoroughly washed with purified heptane to obtain a solid titanium catalyst component.

(3) Production of Prepolymerization Catalyst To 200 mL of heptane, 10 mmol of triethylaluminum, 2 mmol of dicyclopentyldimethoxysilane, and 1 mmol of the solid titanium catalyst component obtained in (2) above were added in terms of titanium atoms. Propylene was continuously introduced while maintaining the internal temperature at 20 ° C. and stirring. After 60 minutes, stirring was stopped, resulting in a prepolymerization catalyst slurry in which 4.0 g of propylene was polymerized per 1 g of the solid titanium catalyst component.

(4) 336 liters of propylene was charged into a 600 liter autoclave of the main polymerization, and the temperature was raised to 60 ° C. Then, 8.7 mL of triethylaluminum, 11.4 mL of dicyclopentyldimethoxysilane, and 2.9 g of the prepolymerization catalyst slurry obtained in (3) above were charged as a solid titanium catalyst component to initiate polymerization. 75 minutes after the start of the polymerization, the temperature was lowered to 50 ° C. over 10 minutes (completion of the first stage polymerization).

The ultimate viscosity [η] of the propylene-based polymer (a1-1) polymerized under the same conditions as in the first stage was 11 dl / g.
After the temperature was lowered, hydrogen was continuously added so that the pressure became constant at 3.3 MPaG, and polymerization was carried out for 141 minutes. Next, the vent valve was opened, and unreacted propylene was purged via an integrated flow meter (completion of polymerization in the second stage).

In this way, 48.5 kg of a powdery propylene-based polymer was obtained. The ratio of the propylene-based polymer (a1-1) produced in the first-stage polymerization to the finally obtained propylene-based polymer calculated from the material balance was 23% by mass, and the second-stage polymerization. The proportion of the propylene-based polymer (a2'-1) produced in the above was 77% by mass, and the ultimate viscosity [η] was 1.30 dl / g.

Irganox 1010 (manufactured by BASF) 2000 ppm, Irgaphos 168 (manufactured by BASF) 2000 ppm, Sandstab P-EPQ (manufactured by Clariant Japan) 1000 ppm as an antioxidant, and steer as a neutralizing agent in this propylene polymer. 1000 ppm of calcium phosphate was added and melt-kneaded using a twin-screw extruder (TEM35BS) manufactured by Toshiba Machine Co., Ltd. to obtain a pellet-shaped propylene-based polymer. The MFR of the propylene-based polymer finally obtained in this manner was 1.5 g / 10 minutes.

[Manufacturing Example 2]
(1) Preparation of solid titanium catalyst component 95.2 g of anhydrous magnesium chloride, 442 mL of decan and 390.6 g of 2-ethylhexyl alcohol are heated at 130 ° C. for 2 hours to prepare a uniform solution, and then phthalic anhydride is added to this solution. 21.3 g of acid was added, and the mixture was further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride.

After cooling the uniform solution thus obtained to room temperature, 75 mL of this uniform solution was added dropwise over 200 mL of titanium tetrachloride kept at −20 ° C. for 1 hour. After charging, the temperature of this mixed solution was raised to 110 ° C. over 4 hours, 5.22 g of diisobutyl phthalate (DIBP) was added when the temperature reached 110 ° C., and the mixture was stirred at the same temperature for 2 hours. Retained.

After completion of the reaction for 2 hours, the solid part was collected by hot filtration, the solid part was resuspended in 275 mL of titanium tetrachloride, and then heated again at 110 ° C. for 2 hours. After completion of the reaction, the solid part was collected again by hot filtration and washed thoroughly with decane and hexane at 110 ° C. until no free titanium compound was detected in the solution.

The solid titanium catalyst component prepared as described above is stored as a hexane slurry, and a part of it was dried to examine the catalyst composition. The solid titanium catalyst component contained 2.3% by mass of titanium, 61% by mass of chlorine, 19% by mass of magnesium, and 12.5% by mass of DIBP.

(2) Preparation of prepolymerization catalyst In a 200 liter autoclave with a stirrer, 140 liters of purified heptane, 0.20 mol of triethylaluminum, and the solid titanium catalyst component obtained above were added to 0.20 mol in terms of titanium atoms in a nitrogen atmosphere. After charging 067 mol, 840 g of propylene was introduced and reacted for 1 hour while keeping the temperature below 20 ° C.

After completion of the polymerization, the inside of the reactor was replaced with nitrogen, and the supernatant was removed and washed with purified heptane three times. The obtained prepolymerization catalyst was resuspended in purified heptane, transferred to a catalyst supply tank, and adjusted with purified heptane so that the solid titanium catalyst component concentration was 1.0 g / L to obtain a prepolymerization catalyst slurry. .. This prepolymerization catalyst slurry contained 6 g of polypropylene per 1 g of the solid titanium catalyst component.

(3) 300 liters of liquefied propylene was charged into a polymerization tank equipped with a stirrer having an internal polymerization volume of 500 liters, and while maintaining this liquid level, 100 kg / h of liquefied propylene was used to obtain the prepolymerization catalyst slurry obtained in (2) above. 1.3 g / h, triethylaluminum 4.2 mL / h, and cyclohexylmethyldimethoxysilane 6.1 mL / h were continuously supplied as solid titanium catalyst components, and polymerized at a temperature of 70 ° C. Here, hydrogen was continuously supplied so that the hydrogen concentration in the gas phase portion in the polymerization tank was 0.3 mol%. The obtained slurry was deactivated and then sent to a washing tank with liquefied propylene to wash the polypropylene powder, and then the propylene was evaporated to obtain a powdery propylene polymer.

Irganox 1010 (manufactured by BASF) 500 ppm and hydrotalcite DHT-4A (manufactured by BASF) 400 ppm are added to this propylene polymer as antioxidants, and a twin-screw extruder (TEM35BS) manufactured by Toshiba Machine Co., Ltd. is added. Was melt-kneaded using the above to obtain a pellet-shaped propylene-based polymer. The MFR of the obtained propylene-based polymer was 3.5 g / 10 minutes, and the ultimate viscosity [η] was 1.9 dl / g.

[Manufacturing Example 3]
(1) Production of prepolymerization catalyst 87.5 g of the solid titanium catalyst component prepared in (1) above of Production Example 2, 19.5 mL of triethylaluminum and 10 liters of heptane are charged into an autoclave with a stirrer having an content of 20 liters. The internal temperature was maintained at 15 to 20 ° C., 263 g of propylene was charged therein, and the mixture was reacted for 100 minutes with stirring. After completion of the reaction, the solid component was precipitated, the supernatant was removed, and washing with heptane was performed twice to obtain a prepolymerization catalyst. The obtained prepolymerization catalyst was resuspended in purified heptane and adjusted with heptane so that the concentration of the solid titanium catalyst component was 0.7 g / L to obtain a prepolymerization catalyst slurry.

(2) 300 liters of liquefied propylene was charged into a polymerization tank equipped with a stirrer having an internal polymerization volume of 500 liters, and while maintaining this liquid level, 130 kg / h of liquefied propylene and the prepolymerization catalyst slurry obtained in (1) above were used. 0.9 g / h, triethylaluminum 4.9 mL / h, and dicyclopentyldimethoxysilane 8.3 mL / h were continuously supplied as solid titanium catalyst components, and polymerized at a temperature of 70 ° C. Here, hydrogen and ethylene were continuously supplied so that the hydrogen concentration in the gas phase portion in the polymerization tank was 0.4 mol% and the ethylene concentration was 2.0 mol%.

The obtained slurry was deactivated and then sent to a washing tank with liquefied propylene to wash the copolymer, and then the propylene was evaporated to obtain a powdery propylene / ethylene copolymer.

Irganox 1010 (manufactured by BASF) 500 ppm and hydrotalcite DHT-4A (manufactured by BASF) 400 ppm were added to this propylene / ethylene copolymer as antioxidants, and a twin-screw extruder manufactured by Toshiba Machine Co., Ltd. It was melt-kneaded using (TEM35BS) to obtain a pellet-shaped propylene / ethylene copolymer. The MFR of the obtained propylene / ethylene copolymer was 0.66 g / 10 minutes, the ultimate viscosity [η] was 2.85 dl / g, and the ethylene content was 4.8% by mass.

[J-452HP]
Made by Prime Polymer Co., Ltd .: Trade name "J-452HP", block type propylene polymer (block PP), MFR = 3.5 g / 10 minutes, extreme viscosity [η] = 1.99 dl / g.

Table 1 shows the physical characteristics of the propylene-based polymer obtained in Production Example 1. Table 2 shows the physical characteristics of the propylene-based polymer and J-452HP obtained in Production Examples 2 and 3.

[Example 1]
The propylene-based polymer obtained in Production Example 1 and the propylene-based polymer obtained in Production Example 2 were blended at a mass ratio of 10:90, and a total of 100 parts by mass of these resins was manufactured by Toshiba Machine Co., Ltd. A polymer composition was obtained by melt-kneading with a twin-screw extruder (TEM35BS). Using the obtained polymer composition, a preform was molded under the above-mentioned molding conditions, and the obtained preform was molded by a cold parison method biaxial stretching blow molding machine.

[Examples 2 to 12]
The same procedure as in Example 1 was carried out except that the compounding composition was changed as shown in Table 3.

[Comparative Example 1]
Using the propylene-based polymer obtained in Production Example 2, a preform was molded under the above molding conditions, and the obtained preform was molded by a cold parison method biaxial stretching blow molding machine. Production Example 2 resulted in a large shrinkage rate after the sterilization treatment.

[Comparative Example 2]
Using the propylene-based polymer obtained in Production Example 3, a preform was molded under the above molding conditions, and the obtained preform was molded by a cold parison method biaxial stretching blow molding machine. Production Example 3 resulted in a large shrinkage rate after the sterilization treatment.

[Comparative Example 3]
A preform was molded under the above molding conditions using J-452HP, and the obtained preform was molded by a cold parison method biaxial stretching blow molding machine. The uneven thickness of the body and the deformation of the neck / bottom were large, resulting in poor stretch blow moldability.

[Comparative Example 4]
The propylene-based polymer obtained in Production Example 2 and J-452HP are blended in a mass ratio of 40:60, and a total of 100 parts by mass of these resins is dispensed by a twin-screw extruder (TEM35BS) manufactured by Toshiba Machine Co., Ltd. A polymer composition was obtained by melt-kneading. Using the obtained polymer composition, a preform was molded under the above-mentioned molding conditions, and the obtained preform was molded by a cold parison method biaxial stretching blow molding machine. The uneven thickness of the body and the deformation of the neck / bottom were large, resulting in poor stretch blow moldability.

In Table 3, (a1) shows the propylene-based polymer (a1-1) in the propylene-based polymer obtained in Production Example 1, and (a2') shows the propylene-based polymer in the propylene-based polymer obtained in Production Example 1. (A2'-1) is shown, and (a2 ") is the propylene-based polymer obtained in Production Examples 2 to 3 or the propylene-based polymer obtained in Production Example 2 or 3, which is mixed with the propylene-based polymer obtained in Production Example 1. J-452HP (these components used in the comparative example are also described as (a2 ")) is shown.

Claims (6)

Propylene-based polymer (a1) having an ultimate viscosity [η] in the range of 10 to 12 dl / g measured in a tetralin solvent at 135 ° C. was measured in 0.5 to 45% by mass and in a tetralin solvent at 135 ° C. The propylene-based polymer (a2) having an ultimate viscosity [η] in the range of 0.5 to 3.5 dl / g was added in an amount of 55 to 99.5% by mass [however, the propylene-based polymer (a1) and the propylene-based weight. The total amount with the coalescence (a2) is 100% by mass. ] Containing propylene-based polymer composition (A). The stretched container according to claim 1, wherein the melt flow rate (MFR) of the propylene-based polymer composition (A) measured at 230 ° C. and a load of 2.16 kg is in the range of 0.01 to 40 g / 10 minutes. .. The area ratio of the high molecular weight region having a molecular weight of 1.5 million or more to the total area of the region surrounded by the molecular weight distribution curve measured by gel permeation chromatography (GPC) of the propylene polymer composition (A) is 1. The stretched container according to claim 1 or 2, which is% or more. ^{The unit area (3000 cm 2} ) of the propylene-based polymer composition (A) is the number of FEs measured using an FE counter for a film having a thickness of 50 μm formed by a 25 mmΦ T-die film forming machine. The stretched container according to any one of claims 1 to 3, wherein [value converted into the number of hits] is 100 or less. The stretched container according to any one of claims 1 to 4, which is a medical container, a food container, a beverage container, a toiletry container, a detergent container or a cosmetic container. The stretched container according to any one of claims 1 to 5, which is an infusion container.