JP2021025015A - Injection molding - Google Patents

Abstract

To provide a propylene polymer-made injection molding having excellent heat resistance and rigidity and a good appearance.SOLUTION: An injection molding is composed of a propylene polymer composition (A) that contains 0.2-8.0 mass% of a propylene polymer (a1) in which an intrinsic viscosity [η] measured at 135°C in a tetralin solvent is 10-12 dl/g and 92.0-99.8 mass% of a propylene polymer (a2) in which an intrinsic viscosity [η] measured at 135°C in a tetralin solvent is 0.5-3.5 dl/g [where, the total content of the propylene polymer (a1) and the propylene polymer (a2) is 100 mass%].SELECTED DRAWING: None

Description

The present invention relates to an injection molded article.

The propylene-based polymer has excellent heat resistance and rigidity (see, for example, Patent Documents 1 to 3), and can be used for various molded products by a molding method such as an injection molding method, a film molding method, a sheet molding method, or a blow molding method. Widely used in manufacturing. For example, injection molded products made of propylene-based polymers are widely used as containers for foods, daily necessities, chemicals, and the like.

International Publication No. 99/7752 JP-A-8-3223 Japanese Patent Application Laid-Open No. 1-254706

Injection molded products made of propylene-based polymers may require even better heat resistance and rigidity depending on the application. When the present inventors have considered adding a high molecular weight component in order to improve these physical properties, the appearance of the product may be deteriorated, such as small lumps (so-called lumps) being generated on the surface of the injection molded product. It was.

An object of the present invention is to provide an injection molded product made of a propylene-based polymer, which is excellent in heat resistance and rigidity and has a good appearance.

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

[1] 0.2 to 8.0% 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., 92.0 to 99.8% by mass of the propylene-based polymer (a2) having an intrinsic viscosity [η] measured in a tetralin solvent in the range of 0.5 to 3.5 dl / g [however, the propylene-based polymer] The total amount of (a1) and the propylene-based polymer (a2) is 100% by mass. ] Containing propylene-based polymer composition (A).

[2] The above-mentioned [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 10 to 100 g / 10 minutes. Injection molded body.

[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 injection-molded article according to the above [1] or [2], wherein the ratio is 2.0 to 7.0%.

[4] The unit area 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 injection-molded article according to any one of [1] to [3] above, wherein the value converted to the number of pieces per 3000 cm ^{2) is 100 or less.}

[5] The injection-molded article according to any one of the above [1] to [4], which is a container.
[6] The injection-molded article according to any one of the above [1] to [4], which is a food packaging container.

According to the present invention, it is possible to provide an injection molded product made of a propylene-based polymer, which is excellent in heat resistance and rigidity and has a good appearance. Further, since the injection-molded article of the present invention has excellent rigidity, it is easy to reduce its weight.

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

[Propylene-based polymer composition (A)]
The propylene-based polymer composition (A) contains 0.2 to 8 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. 92.0-99.8 mass of the propylene-based polymer (a2) having an intrinsic viscosity [η] in the range of 0.5 to 3.5 dl / g measured in a tetralin solvent at 0% by mass and 135 ° C. % [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 0.2 to 8.0% by mass, preferably 1.0 to 8.0% by mass, and more preferably 2.0 to 8. It is in the range of 0% 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 injection moldability tends to be inferior. Further, when the ultimate viscosity [η] of the propylene-based polymer (a1) is less than 10 dl / g, the appearance of the obtained injection molded product tends to be poor (for example, the occurrence of lumps).

If the mass fraction of the propylene polymer (a1) is less than 0.2% by mass, the heat resistance and rigidity of the obtained injection molded product tend to be insufficient, and if it exceeds 8.0% by mass, the obtained injection molded product tends to be insufficient. It tends to cause poor appearance of the body (for example, generation of bumps, deterioration of gloss). In the present invention, it is presumed that by adding a specific amount of the high molecular weight propylene polymer (a1), this (a1) promotes the orientation crystallization and the orientation layer thickness becomes large, and the impact resistance of the injection molded product is increased. It is considered that the heat resistance and rigidity could be improved while maintaining the property.
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 92.0 to 99.8% by mass, preferably 92.0 to 99.0% by mass, and more preferably 92.0 to 98. It is in the range of 0% by mass.

Examples of the propylene-based polymer (a2) 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 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.}

If 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 injection moldability tends to deteriorate.

If the mass fraction of the propylene polymer (a2) is less than 92.0% by mass, it tends to cause poor appearance during injection molding, and if it exceeds 99.8% by mass, the heat resistance of the obtained injection molded product is high. It tends to be inferior in properties and rigidity.

One kind or two or more kinds of propylene-based polymers (a2) can be used.
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) is an antioxidant, a neutralizing agent, a nucleating agent, a heat stabilizer, a weather resistant agent, a lubricant, an antioxidant, an antiblocking agent, and an antioxidant, as long as the object of the present invention is not impaired. Additives such as antifogging agents, anti-bubble agents, dispersants, flame retardants, antibacterial agents, fluorescent whitening agents, cross-linking agents, cross-linking aids; additives such as colorants such as dyes and pigments can be included. 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) has a melt flow rate (MFR) measured at 230 ° C. and a load of 2.16 kg, usually 10 to 100 g / 10 minutes, preferably 10 to 70 g / 10 minutes, more preferably 10 to 50 g. It is in the range of / 10 minutes. When the MFR of the composition (A) is within the above range, the injection moldability and the impact resistance of the obtained injection molded product are 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 (high 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). (Corresponding to the mass ratio of the molecular weight component) is preferably 2.0 to 7.0%, more preferably 2.5 to 7.0%, still more preferably 3.0 to 7.0%. 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, when the area ratio of the high molecular weight region is within the above range, the heat resistance and rigidity of the obtained injection molded product tend to be more excellent.

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 injection molded product may be poor. By setting the number of FEs of the composition (A) within the above range, an injection molded product 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.

A preferred method for producing the composition (A) includes the above method (2). For example, propylene alone or in combination with other monomers in the presence of a catalyst for producing highly stereoregular polypropylene. Then, a method of polymerizing by two-stage or more multi-stage polymerization can be mentioned.

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 10 to 100 g / 10 minutes, preferably 10 to 70 g / 10 minutes, and more preferably 10 to 50 g / 10. Adjust to 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').

In the present invention, the propylene-based polymer composition obtained by blending the polymer mixture obtained by multi-stage polymerization with a propylene-based polymer (a2 ") different from the propylene-based polymer (a2'). The polymer mixture usually has a bimodal molecular weight distribution in a specific range. A propylene-based polymer (a2 ”) using this polymer mixture as a modifier as a base material is preferable. Therefore, the compatibility between the propylene-based polymer (a1), which is a high-molecular-weight component, and the propylene-based polymer (a2 "), which is a base material, tends to be high. Therefore, the propylene-based polymer (a1) tends to be highly compatible. ) Does not cause appearance defects such as lumps and deterioration of surface gloss in the injection molded product, and tends to further improve the heat resistance and rigidity of the injection molded product.

The propylene-based polymer (a2 ") is not particularly limited as long as the obtained composition can be injection-molded, and various known propylene-based polymers can be used. The propylene-based polymer (a2") is also a propylene-based polymer. 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. It is in the range of 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 blended in a desired amount depending on the intended use of the obtained injection polymer.

In the polymer mixture, the content ratio of the propylene-based polymer (a1) is preferably 20 to 50% by mass, and the content ratio of the propylene-based polymer (a2') is preferably 50 to 80% by mass, preferably propylene-based. The content ratio of the polymer (a1) is 25 to 45% by mass, and the content ratio of the propylene-based polymer (a2') is more preferably 55 to 75% by mass.

With respect to a total of 100 parts by mass of the polymer mixture and the propylene-based polymer (a2 ″), the blending amount of the polymer mixture is preferably 1 to 20 mass from the viewpoint of obtaining the modification effect of the polymer mixture. The amount of the propylene-based polymer (a2 ″) to be blended is preferably 80 to 99 parts by mass.

In one embodiment of the composition (A), the content ratio of the propylene-based polymer (a1) is in the range of 0.2 to 8.0% by mass, and the content ratio of the propylene-based polymer (a2') is. It is in the range of 0.8 to 19.8% by mass, and the content ratio of the propylene-based polymer (a2 ") is in the range of 80 to 99% by mass [however, (a1), (a2') and (a2". The total amount with ") 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.

[Injection molded product made of propylene-based polymer composition (A)]
The injection molded product of the present invention is formed from the above-mentioned propylene-based polymer composition (A).
Examples of the injection molded product include containers and home appliance parts. Among these, a container is preferable from the viewpoint of impact resistance and rigidity. Examples of the container include packaging containers for liquid daily necessities such as hair wash agents, hair conditioners, cosmetics, detergents, and bactericides; food packaging containers for liquids such as soft drinks, water, and seasonings; jelly, pudding, yogurt, etc. Food packaging containers for solids (eg, dessert cups); packaging containers for other chemicals; packaging containers for industrial liquids.

Among these, the injection-molded article can be suitably used as a food packaging container (for example, a dessert cup) which is excellent in product appearance and is required to have heat resistance and rigidity. For example, by using a container having high heat resistance, it is possible to raise the production temperature of food and improve the production cycle.

As a container such as a dessert cup, it is preferable that the wall thickness of the container body (thinnest part) is 0.3 to 2.0 mm. The injection-molded article of the present invention has sufficient rigidity even if it is thinned in this way.

Hereinafter, an injection molding method for producing the injection molded product of the present invention will be described. The injection-molded product of the present invention can be obtained, for example, by melting the propylene-based polymer composition (A) and injection-molding the composition (A) in a mold. The melting and injection temperature of the composition (A) is usually in the range of 180 to 280 ° C.

Examples of the injection molding method include the following methods using an injection molding machine. First, the propylene-based polymer composition (A) is introduced into the hopper of the injection molding machine, the composition (A) is sent into a cylinder heated to about 200 to 260 ° C., and the composition (A) is kneaded and plasticized into a molten state. To do. This is injected from a nozzle at high pressure and high speed into a mold closed by a mold clamping mechanism, which is usually temperature-controlled to 5 to 50 ° C., preferably 10 to 40 ° C. with cooling water or hot water. By cooling with a mold, the injected composition (A) is cooled and solidified, and the mold is opened by a mold clamping mechanism to obtain a molded product.

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 the production example, the propylene-based polymer obtained in the first step (corresponding to the propylene-based polymer (a1)) and the propylene-based polymer obtained in the second step (propylene-based polymer (a2)). ) Corresponds to) was determined from the amount of slow heat generated from the reaction heat generated during polymerization.

(2) The ultimate viscosity [η] (dl / g) was measured at 135 ° C. in a tetralin solvent. _{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 Alliance GPC 2000 type (manufactured by Waters)
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: 0.025% (w / v)
Injection volume: 0.4 mL
Sampling time interval: 0.5s
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) 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

(6) Tensile elastic modulus and tensile yield stress (MPa) were measured by preparing test pieces based on JIS K6921 from the pellets obtained in Examples and Comparative Examples and according to the method of JIS K7161.

(7) The Charpy impact strength was measured according to the method of JIS K7111 (23 ° C.).
(8) The deflection temperature under load was measured according to the method of JIS K7191 (0.45 MPa).
(9) The surface gloss was measured according to the method of JIS Z8741.

(10) 0.7 mmt food cup molding A container was molded by the following method using pellets of a propylene-based polymer composition. Using an electric injection molding machine (FANUC Roboshot S-2000i-100B) with a mold clamping force of 100 tons, cylinder temperature 230 ° C, mold temperature 20 ° C, injection primary pressure 120 MPa, injection speed 120 mm / sec, holding Pellets of the propylene-based polymer composition were injection-molded under the conditions of a pressure pressure of 50 MPa and a holding time of 1.0 sec to obtain a container (food cup) having a height of 62 mm, a diameter of 86 mm, and a side wall thickness of 0.7 mm.

The appearance of the container was visually judged according to the following criteria.
◯: Foreign matter cannot be visually recognized when the light of the fluorescent lamp is transmitted.
X: Foreign matter is clearly scattered when the light of the fluorescent lamp is transmitted.
Or there is a large foreign object.

[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. After 83 minutes from the start of polymerization, the temperature was lowered to 45 ° 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 112 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, 35.3 kg of 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 38% by mass, and the second-stage polymerization. The proportion of the propylene-based polymer (a2'-1) produced in the above was 62% by mass, and the ultimate viscosity [η] was 0.89 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 0.2 g / 10 minutes.

[J106MG]
Made by Prime Polymer Co., Ltd .: Product name "J106MG", propylene homopolymer,
Extreme viscosity [η] = 1.4 dl / g

[J137PG]
To the product name "J137G" (manufactured by Prime Polymer: propylene homopolymer, extreme viscosity [η] = 1.2 dl / g), 1000 ppm of NA-11 (manufactured by ADEKA) was added as a nucleating agent, and Toshiba Machine Co., Ltd. A pellet-shaped propylene-based polymer was obtained by melt-kneading using a twin-screw extruder (TEM35BS) manufactured by Japan. The MFR of the propylene-based polymer finally obtained in this manner was 33 g / 10 minutes.

[VP103W]
Made by Prime Polymer Co., Ltd .: Product name "VP103W"
Extreme viscosity [η] = 8 dl / g propylene homopolymer, component amount = 20% by mass
Extreme viscosity [η] = 1.4 dl / g propylene homopolymer, component amount = 80% by mass,
Overall extreme viscosity [η] = 2.8 dl / g

[Example 1]
The propylene-based polymer obtained in Production Example 1 and J106MG were blended in a mass ratio of 5:95, and a total of 100 parts by mass of these resins was dispensed using a twin-screw extruder (TEM35BS) manufactured by Toshiba Machine Co., Ltd. , Pellets of the polymer composition were obtained by melt-kneading at a resin temperature of 203 ° C. Using the obtained pellets, a container was obtained under the above molding conditions.

[Examples 2 to 4, Comparative Examples 2 and 4]
The same procedure as in Example 1 was carried out except that the compounding composition was changed as described in Tables 1 and 2.

[Comparative Examples 1 and 3]
A container was obtained under the above molding conditions using J106MG or J137PG.

Claims (6)

0.2 to 8.0% 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 in a tetralin solvent at 135 ° C. 92.0 to 99.8% by mass of the propylene-based polymer (a2) having the ultimate viscosity [η] in the range of 0.5 to 3.5 dl / g [however, the propylene-based polymer (a1)) The total amount of the propylene-based polymer (a2) and the propylene-based polymer (a2) is 100% by mass. ] Containing propylene-based polymer composition (A). The injection-molded article 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 10 to 100 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 2. The injection-molded article according to claim 1 or 2, which is 0 to 7.0%. ^{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 injection-molded article according to any one of claims 1 to 3, wherein [value converted into the number of hits] is 100 or less. The injection-molded article according to any one of claims 1 to 4, which is a container. The injection-molded article according to any one of claims 1 to 4, which is a food packaging container.